High sodium intake increases blood pressure and alters renal function in intrauterine growth-retarded rats.

PubMed

Sanders, Marijke W; Fazzi, Gregorio E; Janssen, Ger M J; Blanco, Carlos E; De Mey, Jo G R

2005-07-01

A suboptimal fetal environment increases the risk to develop cardiovascular disease in the adult. We reported previously that intrauterine stress in response to reduced uteroplacental blood flow in the pregnant rat limits fetal growth and compromises renal development, leading to an altered renal function in the adult offspring. Here we tested the hypothesis that high dietary sodium intake in rats with impaired renal development attributable to intrauterine stress, results in increased blood pressure, altered renal function, and organ damage. In rats, intrauterine stress was induced by bilateral ligation of the uterine arteries at day 17 of pregnancy. At the age of 12 weeks, the offspring was given high-sodium drinking water (2% sodium chloride). At the age of 16 weeks, rats were instrumented for monitoring of blood pressure and renal function. After intrauterine stress, litter size and birth weight were reduced, whereas hematocrit at birth was increased. Renal blood flow, glomerular filtration rate, and the glomerular filtration fraction were increased significantly after intrauterine stress. High sodium intake did not change renal function and blood pressure in control animals. However, during high sodium intake in intrauterine stress offspring, renal blood flow, glomerular filtration rate, and the filtration fraction were decreased, and blood pressure was increased. In addition, these animals developed severe albuminuria, an important sign of renal dysfunction. Thus, a suboptimal fetal microenvironment, which impairs renal development, results in sodium-dependent hypertension and albuminuria.

Renal function, renal volume, and blood pressure in infants with antecedent of antenatal steroids.

PubMed

Carballo-Magdaleno, Deyanira; Guízar-Mendoza, Juan M; Amador-Licona, Norma; Domínguez-Domínguez, Víctor

2011-10-01

Steroids have been used for more than 20 years in preterm infants to induce pulmonary maturity; however, some long-term effects have been reported, such as insulin resistance and elevation of blood pressure. The aim of our study was to compare renal volume, renal function, and blood pressure in infants between 12-36 months of age with and without antecedent of antenatal steroid treatment. This was a cross-sectional study comprised of three groups of infants (n = 30, respectively): preterm infants with and without antecedent of receiving antenatal steroids, respectively, and full-term infants. Blood pressure, renal volume, glomerular filtration rate, and tubular function were measured. Blood pressure and cystatin C levels and glomerular filtration rate were higher in both groups of preterm infants than in the control group (p < 0.01). However, no difference in any of the tested variables between the steroid and non-steroid group of preterm infants. Renal volume was similar in preterm and control infants. Based on these results, we conclude that prematurity independent of antenatal steroid use is associated with higher cystatin C and blood pressure levels and a higher glomerular filtration rate in infants between 12-36 months of age.

Music improves dopaminergic neurotransmission: demonstration based on the effect of music on blood pressure regulation.

PubMed

Sutoo, Den'etsu; Akiyama, Kayo

2004-08-06

The mechanism by which music modifies brain function is not clear. Clinical findings indicate that music reduces blood pressure in various patients. We investigated the effect of music on blood pressure in spontaneously hypertensive rats (SHR). Previous studies indicated that calcium increases brain dopamine (DA) synthesis through a calmodulin (CaM)-dependent system. Increased DA levels reduce blood pressure in SHR. In this study, we examined the effects of music on this pathway. Systolic blood pressure in SHR was reduced by exposure to Mozart's music (K.205), and the effect vanished when this pathway was inhibited. Exposure to music also significantly increased serum calcium levels and neostriatal DA levels. These results suggest that music leads to increased calcium/CaM-dependent DA synthesis in the brain, thus causing a reduction in blood pressure. Music might regulate and/or affect various brain functions through dopaminergic neurotransmission, and might therefore be effective for rectification of symptoms in various diseases that involve DA dysfunction.

Relationship between blood pressure, cognitive function and education level in elderly patients with diabetes: a preliminary study.

PubMed

Talfournier, J; Bitu, J; Paquet, C; Gobron, C; Guillausseau, P J; Hugon, J; Dumurgier, J

2013-10-01

This study aimed to assess the relationship between blood pressure and cognitive function in elderly patients with diabetes mellitus (DM). A total of 32 patients with DM aged ≥ 65 years (seven women and 25 men; mean ± SD age: 74.3 ± 6.4 years) were included in this cross-sectional study. Relationships between blood pressure and neuropsychological tests were determined using Spearman's rank correlations (ρ) and multivariable linear regression models. Lower diastolic blood pressure was associated with lower scores on the Frontal Assessment Battery (ρ=0.32, P=0.02), longer times to complete the Trail Making Test Part B (ρ=0.51, P=0.003), lower scores for the Finger Tapping Test (ρ=0.36, P=0.046) and less verbal fluency (ρ=0.36, P=0.047). In multivariable models, these relationships were attenuated after adjusting for levels of education. There was an association between lower diastolic blood pressure and poorer executive function in this cohort of elderly DM patients. These results underline the importance of systematic cognitive evaluation in elderly patients with DM, and suggest that a too-low diastolic blood pressure may have deleterious effects on mental function. Larger studies in the future are required to confirm these preliminary results. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Dietary Flavanols: A Review of Select Effects on Vascular Function, Blood Pressure, and Exercise Performance.

PubMed

Al-Dashti, Yousef A; Holt, Roberta R; Stebbins, Charles L; Keen, Carl L; Hackman, Robert M

2018-05-02

An individual's diet affects numerous physiological functions and can play an important role in reducing the risk of cardiovascular disease. Epidemiological and clinical studies suggest that dietary flavanols can be an important modulator of vascular risk. Diets and plant extracts rich in flavanols have been reported to lower blood pressure, especially in prehypertensive and hypertensive individuals. Flavanols may act in part through signaling pathways that affect vascular function, nitric oxide availability, and the release of endothelial-derived relaxing and constricting factors. During exercise, flavanols have been reported to modulate metabolism and respiration (e.g., maximal oxygen uptake, O 2 cost of exercise, and energy expenditure), and reduce oxidative stress and inflammation, resulting in increased skeletal muscle efficiency and endurance capacity. Flavanol-induced reductions in blood pressure during exercise may decrease the work of the heart. Collectively, these effects suggest that flavanols can act as an ergogenic aid to help delay the onset of fatigue. More research is needed to better clarify the effects of flavanols on vascular function, blood pressure regulation, and exercise performance and establish safe and effective levels of intake. Flavanol-rich foods and food products can be useful components of a healthy diet and lifestyle program for those seeking to better control their blood pressure or to enhance their physical activity. Key teaching points • Epidemiological and clinical studies indicate that dietary flavanols can reduce the risk of vascular disease. • Diets and plant extracts rich in flavanols have been reported to lower blood pressure and improve exercise performance in humans. • Mechanisms by which flavanols may reduce blood pressure function include alterations in signaling pathways that affect vascular function, nitric oxide availability, and the release of endothelial-derived relaxation and constriction factors. • Mechanisms by which flavanols may enhance exercise performance include modulation of metabolism and respiration (e.g., maximal oxygen uptake, O 2 cost of exercise, and energy expenditure) and reduction of oxidative stress and inflammation. These effects can result in increased skeletal muscle efficiency and endurance capacity. • Further research is needed to clarify the amount, timing, and frequency of flavanol intake for blood pressure regulation and exercise performance.

Renal and blood pressure effects from environmental cadmium exposure in Thai children

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com; Mahasakpan, Pranee; Jeekeeree, Wanpen

Very few studies have shown renal and blood pressure effects from environmental cadmium exposure in children. This population study examined associations between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and renal dysfunctions and blood pressure in environmentally exposed Thai children. Renal functions including urinary excretion of β{sub 2}-microglobulin, calcium (early renal effects), and total protein (late renal effect), and blood pressure were measured in 594 primary school children. Of the children studied, 19.0% had urinary cadmium ≥1 μg/g creatinine. The prevalence of urinary cadmium ≥1 μg/g creatinine was significantly higher in girls and in those consuming ricemore » grown in cadmium-contaminated areas. The geometric mean levels of urinary β{sub 2}-microglobulin, calcium, and total protein significantly increased with increasing tertiles of urinary cadmium. The analysis did not show increased blood pressure with increasing tertiles of urinary cadmium. After adjusting for age, sex, and blood lead levels, the analysis showed significant positive associations between urinary cadmium and urinary β{sub 2}-microglobulin and urinary calcium, but not urinary total protein nor blood pressure. Our findings provide evidence that environmental cadmium exposure can affect renal functions in children. A follow-up study is essential to assess the clinical significance and progress of renal effects in these children. - Highlights: • Few studies show renal effects from environmental cadmium exposure in children. • We report renal and blood pressure effects from cadmium exposure in Thai children. • Urinary β{sub 2}-microglobulin and calcium increased with increasing urinary cadmium. • The study found no association between urinary cadmium levels and blood pressure. • Environmental cadmium exposure can affect renal functions in children.« less

Accelerated decline of renal function in type 2 diabetes following severe hypoglycemia.

PubMed

Tsujimoto, Tetsuro; Yamamoto-Honda, Ritsuko; Kajio, Hiroshi; Kishimoto, Miyako; Noto, Hiroshi; Hachiya, Remi; Kimura, Akio; Kakei, Masafumi; Noda, Mitsuhiko

2016-01-01

This study aimed to evaluate whether the pronounced elevation in blood pressure during severe hypoglycemia is associated with subsequent renal insufficiency. We conducted a 3-year cohort study to assess the clinical course of renal function in type 2 diabetes patients with or without blood pressure surge during severe hypoglycemia. Of 111 type 2 diabetes patients with severe hypoglycemia, 76 exhibited an extremely high systolic blood pressure before treatment, whereas 35 demonstrated no such increase (179.1 ± 27.7 mmHg vs. 131.1 ± 20.2 mmHg, P<0.001). At 12h after treatment, systolic blood pressure did not differ significantly (131.5 ± 30.7 mmHg vs. 123.5 ± 20.7 mmHg; P=0.39). The estimated glomerular filtration rate (GFR) before and at the time of severe hypoglycemia did not significantly differ between both groups. A multivariate Cox proportional hazards regression analysis revealed that blood pressure surge during severe hypoglycemia was independently associated with a composite outcome of a more than 15 mL/min/1.73 m(2) decrease in the estimated GFR and initiation of chronic dialysis (hazard ratio, 2.68; 95% confidence interval, 1.12-6.38; P=0.02). Renal function after severe hypoglycemia was significantly worse in type 2 diabetes patients with blood pressure surge during severe hypoglycemia than those without blood pressure surge. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

[Circulatory Function Tests for Home & Community Use.

PubMed

Shimetani, Naoto

2016-05-01

Currently, the main circulatory function-testing tools for home use are blood pressure monitors and elec- trocardiography devices. Just like blood pressure monitors that are already widespread for home use, some devices with an electrocardiographic function have recently become available for purchase for personal use by the general public. On the other hand, clinic equipment on loan from doctors to patients in need can perform circulatory function tests like 24-hour ambulatory blood pressure monitoring (ABPM), Holter monitoring, and real-time electrocardiography. We introduce the actual clinical usage of ABPM and real-time electro- cardiography, and discuss the usefulness of these procedures. ABPM uses a blood pressure measurement device worn on the body for 24 hours a day to measure blood pressure at regular intervals. This makes it possible to check blood pressure changes throughout the day in a way in which conventional home-use blood pressure monitors cannot, like during sleep. This method al- lows the identification of masked hypertension like early-morning and nocturnal hypertension, stress hyper- tension including workplace hypertension, and white coat hypertension that only occurs in the doctor's office. Under routine care, there are few opportunities to perform electrocardiography at the time a patient is experiencing symptoms. Now, real-time electrocardiography has begun to be used in routine care, and pa- tients can record an electrocardiogram by themselves anytime, anywhere, and send the data by telephone or the Internet for analysis and diagnosis. Transmission-capable electrocardiography devices can play an im- portant role in the event of dangerous symptoms like arrhythmia, angina, or acute myocardial infarction. The spread of ABPM and event heart monitors is likely to make the early treatment and prevention of stroke and heart disease possible. We are expecting rapid development in this field in the future.

Differences in Blood Pressure and Vascular Responses Associated with Ambient Fine Particulate Matter Exposures Measured at the Personal Versus Community Level

EPA Science Inventory

Background Higher ambient fine particulate matter (PM_2.5) levels can be associated with increased blood pressure and vascular dysfunction. Objectives To determine the differential effects on blood pressure and vascular function of daily changes in community ambient-...

Increased response of diastolic blood pressure to exercise in patients with coronary artery disease: an index of latent ventricular dysfunction?

PubMed Central

Paraskevaidis, I A; Kremastinos, D T; Kassimatis, A S; Karavolias, G K; Kordosis, G D; Kyriakides, Z S; Toutouzas, P K

1993-01-01

OBJECTIVE--To determine whether an abnormal response of diastolic blood pressure during treadmill exercise stress testing correlated with the number of obstructed vessels and with left ventricular systolic function in patients with coronary artery disease. DESIGN--Diastolic blood pressure was measured invasively during exercise stress testing and coronary angiograms and left ventriculograms were obtained at rest in patients with coronary artery disease. The abnormal (> or = 15 mm Hg) diastolic blood pressure response was compared with the number of obstructed coronary arteries and with left ventricular systolic function. SETTING--Two tertiary referral centres. PATIENTS--50 consecutive patients (mean age 57 years) with coronary artery disease. MAIN OUTCOME MEASURES--The increase in diastolic blood pressure during exercise and its correlation with the appearance and disappearance of ST segment deviation, resting left ventricular systolic function, and the number of obstructed coronary arteries. RESULTS--Group 1: 10 (20%) patients (three with one, four with two, and three with three vessel coronary artery disease) (mean (SD) age 54.7 (12) years) had an abnormal diastolic blood pressure response that appeared 1.2 (0.3) min before ST segment deviation and became normal 0.9 (0.3) min after the ST segment returned to normal. Group 2: 40 (80%) patients (12 with one, 16 with two, and 12 with three vessel coronary arteries disease) (aged 56.8 (8.2) years) had a normal diastolic blood pressure response to stress testing. The ejection fraction (46.3 (5)%) and cardiac index (2.6 (0.1) 1/min/m2) in group 1 were less than in group 2 (61.6 (4.2)% and 3.8 (0.3) 1/min/m2 respectively, p < or = 0.001). The end systolic volume was greater in group 1 than in group 2: 38.7 (0.7 ml/m2 v 28.2 (2.1) ml/m2, p < or = 0.001. CONCLUSION--In patients with coronary artery disease an abnormal increase in diastolic blood pressure during exercise stress testing correlated well with left ventricular systolic function at rest but not with the number of obstructed coronary arteries. The abnormal response of diastolic blood pressure probably reflects deterioration of myocardial function. Images PMID:8343317

Flavonoid-rich apples and nitrate-rich spinach augment nitric oxide status and improve endothelial function in healthy men and women: a randomized controlled trial.

PubMed

Bondonno, Catherine P; Yang, Xingbin; Croft, Kevin D; Considine, Michael J; Ward, Natalie C; Rich, Lisa; Puddey, Ian B; Swinny, Ewald; Mubarak, Aidilla; Hodgson, Jonathan M

2012-01-01

Flavonoids and nitrates in fruits and vegetables may protect against cardiovascular disease. Dietary flavonoids and nitrates can augment nitric oxide status via distinct pathways, which may improve endothelial function and lower blood pressure. Recent studies suggest that the combination of flavonoids and nitrates can enhance nitric oxide production in the stomach. Their combined effect in the circulation is unclear. Here, our objective was to investigate the independent and additive effects of flavonoid-rich apples and nitrate-rich spinach on nitric oxide status, endothelial function, and blood pressure. A randomized, controlled, crossover trial with healthy men and women (n=30) was conducted. The acute effects of four energy-matched treatments (control, apple, spinach, and apple+spinach), administered in random order, were compared. Measurements included plasma nitric oxide status, assessed by measuring S-nitrosothiols+other nitrosylated species (RXNO) and nitrite, blood pressure, and endothelial function, measured as flow-mediated dilatation of the brachial artery. Results are means and 95% CI. Relative to control, all treatments resulted in higher RXNO (control, 33 nmol/L, 26, 42; apple, 51 nmol/L, 40, 65; spinach, 86 nmol/L, 68, 110; apple+spinach, 69 nmol/L, 54, 88; P<0.01) and higher nitrite (control, 35 nmol/L, 27, 46; apple, 69 nmol/L, 53, 90; spinach, 99 nmol/L, 76, 129; apple+spinach, 80 nmol/L, 61, 104; P<0.01). Compared to control, all treatments resulted in higher flow-mediated dilatation (P<0.05) and lower pulse pressure (P<0.05), and apple and spinach resulted in lower systolic blood pressure (P<0.05). No significant effect was observed on diastolic blood pressure. The combination of apple and spinach did not result in additive effects on nitric oxide status, endothelial function, or blood pressure. In conclusion, flavonoid-rich apples and nitrate-rich spinach can independently augment nitric oxide status, enhance endothelial function, and lower blood pressure acutely, outcomes that may benefit cardiovascular health. Copyright © 2011 Elsevier Inc. All rights reserved.

The effects of a lupin-enriched diet on oxidative stress and factors influencing vascular function in overweight subjects.

PubMed

Yang, Xingbin; Croft, Kevin D; Lee, Ya P; Mori, Trevor A; Puddey, Ian B; Sipsas, Sofia; Barden, Anne; Swinny, Ewald; Hodgson, Jonathan M

2010-11-15

A diet enriched in lupin kernel flour can lower blood pressure, but mechanisms responsible are unclear. Lupin is a source of polyphenols, protein, and L-arginine, factors that may influence blood pressure via effects on oxidative stress and vascular function. Therefore, we aimed to determine the effects of a lupin-enriched diet on oxidative stress and factors influencing vascular function as potential mechanisms for demonstrated benefits on blood pressure. Overweight men and women (n = 88) were recruited to a 16-week parallel-design study. Participants were randomly assigned to replace 15%-20% of their usual daily energy intake with white bread (control) or lupin kernel flour-enriched bread (lupin). All measurements were taken at baseline and 16 weeks. At baseline, plasma F₂-isoprostanes and 20-hydroxyeicosatetraenoic acid (20-HETE) were positively associated with blood pressure, and plasma nitrite was negatively associated with blood pressure (p < 0.05). For lupin relative to control, the estimated differences in plasma F₂-isoprostanes (45 pmol/L; 95%CI: -68, 158), urinary F₂-isoprostanes (17 pmol/mmol creatinine; 95%CI: -43, 76), plasma 20-HETE (75 pmol/L; 95%CI: -91, 241), and plasma nitrite (-0.3 μmol/L; 95%CI: -1.1, 0.4) were not significant. Although regular consumption of lupin-enriched bread can lower blood pressure, these results do not support for the hypothesis that this is via effects on oxidative stress or vascular function.

Sleep Related Changes in Blood Pressure in Hypocretin-Deficient Narcoleptic Mice

PubMed Central

Bastianini, Stefano; Silvani, Alessandro; Berteotti, Chiara; Elghozi, Jean-Luc; Franzini, Carlo; Lenzi, Pierluigi; Lo, Martire Viviana; Zoccoli, Giovanna

2011-01-01

Study Objectives: Although blood pressure during sleep and the difference in blood pressure between sleep and wakefulness carry prognostic information, little is known on their central neural mechanisms. Hypothalamic neurons releasing hypocretin (orexin) peptides control wake-sleep behavior and autonomic functions and are lost in narcolepsy-cataplexy. We investigated whether chronic lack of hypocretin signaling alters blood pressure during sleep. Design: Comparison of blood pressure as a function of the wake-sleep behavior between 2 different hypocretin-deficient mouse models and control mice with the same genetic background. Setting: N/A. Subjects: Hypocretin-ataxin3 transgenic mice with genetic ablation of hypocretin neurons (TG, n = 12); hypocretin gene knock-out mice (KO, n = 8); congenic wild-type controls (WT, n = 10). Interventions: Instrumentation with electrodes for sleep recordings and a telemetric blood pressure transducer. Measurements and Results: Blood pressure was significantly higher in either TG or KO than in WT during non–rapid eye movement sleep (NREMS; 4 ± 2 and 7 ± 2 mm Hg, respectively) and rapid eye movement sleep (REMS; 11 ± 2 and 12 ± 3 mm Hg, respectively), whereas it did not differ significantly between groups during wakefulness. Accordingly, the decrease in blood pressure between either NREMS or REMS and wakefulness was significantly blunted in TG and KO with respect to WT. Conclusions: Chronic lack of hypocretin signaling may entail consequences on blood pressure that are potentially adverse and that vary widely among wake-sleep states. Citation: Bastianini S; Silvani A; Berteotti C; Elghozi JL; Franzini C; Lenzi P; Lo Martire V; Zoccoli G. Sleep related changes in blood pressure in hypocretin-deficient narcoleptic mice. SLEEP 2011;34(2):213-218. PMID:21286242

[Effect of occupational stress on cardiovascular function of different vocational population].

PubMed

Yao, San-qiao; Fan, Xue-yun; Jin, Yu-lan; Bai, Yu-ping; Qu, Yin-e; Zhou, Yuan

2003-02-01

To study the effect of occupational stress on cardiovascular function of different vocational population. The occupational stressors, risk factors of cardiovascular diseases were investigated by questionnaire in 839 people with 4 kinds of jobs. Blood pressure, sugar, and lipid were detected at the same time. Blood pressure were higher in the groups of old age, long standing and teachers, and the abnormal rate of blood pressure was 21.69%. There was no difference in abnormal ECG among ages, standing and occupation, and the abnormal rate of ECG was 19.07%. Job control, job demands, job responsibility, role in a job and shift work were the main stress factors affecting systolic and diastolic blood pressure. More conflict in job, less chance of participation, severe job loads were the risk factors of primary hypertension. Accident due to job responsibility, job responsibility, role in a job were the main risk factors of abnormal electrocardiograph. Self-respect and activity beyond work were the good modifiers of heart function. Occupational stress has certain effect on cardiovascular function.

On the Importance of Knowing Your Partner’s Views: Attitude Familiarity is Associated with Better Interpersonal Functioning and Lower Ambulatory Blood Pressure in Daily Life

PubMed Central

Birmingham, Wendy

2011-01-01

Background Relationships have been linked to significant physical health outcomes. However, little is known about the more specific processes that might be responsible for such links. Purpose The main aim of this study was to examine a previously unexplored and potentially important form of partner knowledge (i.e., attitude familiarity) on relationship processes and cardiovascular function. Methods In this study, 47 married couples completed an attitude familiarity questionnaire and ambulatory assessments of daily spousal interactions and blood pressure. Results Attitude familiarity was associated with better interpersonal functioning between spouses in daily life (e.g., greater partner responsiveness). Importantly, attitude familiarity was also related to lower overall ambulatory systolic blood pressure and diastolic blood pressure. Conclusions These data suggest that familiarity with a spouse’s attitudes may be an important factor linking relationships to better interpersonal and physical health outcomes. PMID:20878291

Cognitive Function and Emotional Status of Middle-aged Chinese Hypertensive Patients Without Detectable White Matter Brain Lesions or Lacunar Infarctions

DTIC Science & Technology

2006-08-30

readings and one blood sample were taken. Blood was tested for levels of serum glucose, total cholesterol , triglycerides , high density lipoproteins ...Glynn et al., 1999) suggest an inverted U- shaped relationship between blood pressure level and cognitive function such that very low and very high ...to support the hypothesis that alterations in cerebral white matter may explain the relationship between high blood pressure levels and cognitive

Burst stimulation improves hemodynamics during resuscitation after prolonged ventricular fibrillation.

PubMed

Walcott, Gregory; Melnick, Sharon; Killingsworth, Cheryl; Ideker, Raymond

2009-02-01

Although return of spontaneous circulation (ROSC) is frequently achieved during resuscitation for sudden cardiac arrest, systolic blood pressure can then decrease, requiring additional myocardial support. Previous studies have shown that a series of 1-ms electrical pulses delivered through the defibrillation patches during ventricular fibrillation (VF) can stimulate the autonomic nervous system to increase myocardial function following defibrillation. We hypothesized that a similar series of electrical pulses could increase myocardial function and blood pressure during the early post-resuscitation period. Six swine were studied that underwent 6-7 min. Each animal received 5, 10, 15, or 20 pulse packets consisting of 6 10 A, 1-ms pulses every 3-4 s in random order whenever systolic blood pressure became less than 50 mmHg. All four sets of pulse packets were delivered to each animal. Systolic blood pressure and cardiac function (left ventricular +dP/dt) were increased to pre-stimulation levels or above by all four sets of pulse packets. The increases were significantly greater for the longer than the shorter number of pulse packets. The mean+/-SD duration of the time that the systolic pressure remained above 50 mmHg following pulse delivery was 4.2+/-2.5 min. Electrical stimulation during regular rhythm following prolonged VF and resuscitation can increase blood pressure and cardiac function to above prestimulation levels.

Burst Stimulation Improves Hemodynamics During Resuscitation after Prolonged Ventricular Fibrillation

PubMed Central

Walcott, Gregory; Melnick, Sharon; Killingsworth, Cheryl; Ideker, Raymond

2009-01-01

Background Although return of spontaneous circulation (ROSC) is frequently achieved during resuscitation for sudden cardiac arrest, systolic blood pressure can then decrease, requiring additional myocardial support. Previous studies have shown that a series of 1-ms electrical pulses delivered through the defibrillation patches during ventricular fibrillation (VF) can stimulate the autonomic nervous system to increase myocardial function following defibrillation. We hypothesized that a similar series of electrical pulses could increase myocardial function and blood pressure during the early post-resuscitation period. Methods and Results Six swine were studied that underwent 6–7 min. Each animal received 5, 10, 15, or 20 pulse packets consisting of 6 10 A, 1-ms pulses every 3–4 s in random order whenever systolic blood pressure became less than 50 mmHg. All four sets of pulse packets were delivered to each animal. Systolic blood pressure and cardiac function (left ventricular +dP/dt) were increased to pre-stimulation levels or above by all four sets of pulse packets. The increases were significantly greater for the longer than the shorter number of pulse packets. The mean±SD duration of the time that the systolic pressure remained above 50 mmHg following pulse delivery was 4.2±2.5 min. Conclusions Electrical stimulation during regular rhythm following prolonged VF and resuscitation can increase blood pressure and cardiac function to above pre-arrest levels. PMID:19655042

Measures of blood pressure and cognition in dialysis patients

USDA-ARS?s Scientific Manuscript database

There are few reports on the relationship of blood pressure with cognitive function in maintenance dialysis patients. The Cognition and Dialysis Study is an ongoing investigation of cognitive function and its risk factors in six Boston area hemodialysis units. In this analysis, we evaluated the rela...

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk.

PubMed

Ehret, Georg B; Munroe, Patricia B; Rice, Kenneth M; Bochud, Murielle; Johnson, Andrew D; Chasman, Daniel I; Smith, Albert V; Tobin, Martin D; Verwoert, Germaine C; Hwang, Shih-Jen; Pihur, Vasyl; Vollenweider, Peter; O'Reilly, Paul F; Amin, Najaf; Bragg-Gresham, Jennifer L; Teumer, Alexander; Glazer, Nicole L; Launer, Lenore; Zhao, Jing Hua; Aulchenko, Yurii; Heath, Simon; Sõber, Siim; Parsa, Afshin; Luan, Jian'an; Arora, Pankaj; Dehghan, Abbas; Zhang, Feng; Lucas, Gavin; Hicks, Andrew A; Jackson, Anne U; Peden, John F; Tanaka, Toshiko; Wild, Sarah H; Rudan, Igor; Igl, Wilmar; Milaneschi, Yuri; Parker, Alex N; Fava, Cristiano; Chambers, John C; Fox, Ervin R; Kumari, Meena; Go, Min Jin; van der Harst, Pim; Kao, Wen Hong Linda; Sjögren, Marketa; Vinay, D G; Alexander, Myriam; Tabara, Yasuharu; Shaw-Hawkins, Sue; Whincup, Peter H; Liu, Yongmei; Shi, Gang; Kuusisto, Johanna; Tayo, Bamidele; Seielstad, Mark; Sim, Xueling; Nguyen, Khanh-Dung Hoang; Lehtimäki, Terho; Matullo, Giuseppe; Wu, Ying; Gaunt, Tom R; Onland-Moret, N Charlotte; Cooper, Matthew N; Platou, Carl G P; Org, Elin; Hardy, Rebecca; Dahgam, Santosh; Palmen, Jutta; Vitart, Veronique; Braund, Peter S; Kuznetsova, Tatiana; Uiterwaal, Cuno S P M; Adeyemo, Adebowale; Palmas, Walter; Campbell, Harry; Ludwig, Barbara; Tomaszewski, Maciej; Tzoulaki, Ioanna; Palmer, Nicholette D; Aspelund, Thor; Garcia, Melissa; Chang, Yen-Pei C; O'Connell, Jeffrey R; Steinle, Nanette I; Grobbee, Diederick E; Arking, Dan E; Kardia, Sharon L; Morrison, Alanna C; Hernandez, Dena; Najjar, Samer; McArdle, Wendy L; Hadley, David; Brown, Morris J; Connell, John M; Hingorani, Aroon D; Day, Ian N M; Lawlor, Debbie A; Beilby, John P; Lawrence, Robert W; Clarke, Robert; Hopewell, Jemma C; Ongen, Halit; Dreisbach, Albert W; Li, Yali; Young, J Hunter; Bis, Joshua C; Kähönen, Mika; Viikari, Jorma; Adair, Linda S; Lee, Nanette R; Chen, Ming-Huei; Olden, Matthias; Pattaro, Cristian; Bolton, Judith A Hoffman; Köttgen, Anna; Bergmann, Sven; Mooser, Vincent; Chaturvedi, Nish; Frayling, Timothy M; Islam, Muhammad; Jafar, Tazeen H; Erdmann, Jeanette; Kulkarni, Smita R; Bornstein, Stefan R; Grässler, Jürgen; Groop, Leif; Voight, Benjamin F; Kettunen, Johannes; Howard, Philip; Taylor, Andrew; Guarrera, Simonetta; Ricceri, Fulvio; Emilsson, Valur; Plump, Andrew; Barroso, Inês; Khaw, Kay-Tee; Weder, Alan B; Hunt, Steven C; Sun, Yan V; Bergman, Richard N; Collins, Francis S; Bonnycastle, Lori L; Scott, Laura J; Stringham, Heather M; Peltonen, Leena; Perola, Markus; Vartiainen, Erkki; Brand, Stefan-Martin; Staessen, Jan A; Wang, Thomas J; Burton, Paul R; Soler Artigas, Maria; Dong, Yanbin; Snieder, Harold; Wang, Xiaoling; Zhu, Haidong; Lohman, Kurt K; Rudock, Megan E; Heckbert, Susan R; Smith, Nicholas L; Wiggins, Kerri L; Doumatey, Ayo; Shriner, Daniel; Veldre, Gudrun; Viigimaa, Margus; Kinra, Sanjay; Prabhakaran, Dorairaj; Tripathy, Vikal; Langefeld, Carl D; Rosengren, Annika; Thelle, Dag S; Corsi, Anna Maria; Singleton, Andrew; Forrester, Terrence; Hilton, Gina; McKenzie, Colin A; Salako, Tunde; Iwai, Naoharu; Kita, Yoshikuni; Ogihara, Toshio; Ohkubo, Takayoshi; Okamura, Tomonori; Ueshima, Hirotsugu; Umemura, Satoshi; Eyheramendy, Susana; Meitinger, Thomas; Wichmann, H-Erich; Cho, Yoon Shin; Kim, Hyung-Lae; Lee, Jong-Young; Scott, James; Sehmi, Joban S; Zhang, Weihua; Hedblad, Bo; Nilsson, Peter; Smith, George Davey; Wong, Andrew; Narisu, Narisu; Stančáková, Alena; Raffel, Leslie J; Yao, Jie; Kathiresan, Sekar; O'Donnell, Christopher J; Schwartz, Stephen M; Ikram, M Arfan; Longstreth, W T; Mosley, Thomas H; Seshadri, Sudha; Shrine, Nick R G; Wain, Louise V; Morken, Mario A; Swift, Amy J; Laitinen, Jaana; Prokopenko, Inga; Zitting, Paavo; Cooper, Jackie A; Humphries, Steve E; Danesh, John; Rasheed, Asif; Goel, Anuj; Hamsten, Anders; Watkins, Hugh; Bakker, Stephan J L; van Gilst, Wiek H; Janipalli, Charles S; Mani, K Radha; Yajnik, Chittaranjan S; Hofman, Albert; Mattace-Raso, Francesco U S; Oostra, Ben A; Demirkan, Ayse; Isaacs, Aaron; Rivadeneira, Fernando; Lakatta, Edward G; Orru, Marco; Scuteri, Angelo; Ala-Korpela, Mika; Kangas, Antti J; Lyytikäinen, Leo-Pekka; Soininen, Pasi; Tukiainen, Taru; Würtz, Peter; Ong, Rick Twee-Hee; Dörr, Marcus; Kroemer, Heyo K; Völker, Uwe; Völzke, Henry; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Zelenika, Diana; Deloukas, Panos; Mangino, Massimo; Spector, Tim D; Zhai, Guangju; Meschia, James F; Nalls, Michael A; Sharma, Pankaj; Terzic, Janos; Kumar, M V Kranthi; Denniff, Matthew; Zukowska-Szczechowska, Ewa; Wagenknecht, Lynne E; Fowkes, F Gerald R; Charchar, Fadi J; Schwarz, Peter E H; Hayward, Caroline; Guo, Xiuqing; Rotimi, Charles; Bots, Michiel L; Brand, Eva; Samani, Nilesh J; Polasek, Ozren; Talmud, Philippa J; Nyberg, Fredrik; Kuh, Diana; Laan, Maris; Hveem, Kristian; Palmer, Lyle J; van der Schouw, Yvonne T; Casas, Juan P; Mohlke, Karen L; Vineis, Paolo; Raitakari, Olli; Ganesh, Santhi K; Wong, Tien Y; Tai, E Shyong; Cooper, Richard S; Laakso, Markku; Rao, Dabeeru C; Harris, Tamara B; Morris, Richard W; Dominiczak, Anna F; Kivimaki, Mika; Marmot, Michael G; Miki, Tetsuro; Saleheen, Danish; Chandak, Giriraj R; Coresh, Josef; Navis, Gerjan; Salomaa, Veikko; Han, Bok-Ghee; Zhu, Xiaofeng; Kooner, Jaspal S; Melander, Olle; Ridker, Paul M; Bandinelli, Stefania; Gyllensten, Ulf B; Wright, Alan F; Wilson, James F; Ferrucci, Luigi; Farrall, Martin; Tuomilehto, Jaakko; Pramstaller, Peter P; Elosua, Roberto; Soranzo, Nicole; Sijbrands, Eric J G; Altshuler, David; Loos, Ruth J F; Shuldiner, Alan R; Gieger, Christian; Meneton, Pierre; Uitterlinden, Andre G; Wareham, Nicholas J; Gudnason, Vilmundur; Rotter, Jerome I; Rettig, Rainer; Uda, Manuela; Strachan, David P; Witteman, Jacqueline C M; Hartikainen, Anna-Liisa; Beckmann, Jacques S; Boerwinkle, Eric; Vasan, Ramachandran S; Boehnke, Michael; Larson, Martin G; Järvelin, Marjo-Riitta; Psaty, Bruce M; Abecasis, Gonçalo R; Chakravarti, Aravinda; Elliott, Paul; van Duijn, Cornelia M; Newton-Cheh, Christopher; Levy, Daniel; Caulfield, Mark J; Johnson, Toby

2011-09-11

Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or  ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.

“Do it-yourself”: Home blood pressure as a predictor of traditional and everyday cognition in older adults

PubMed Central

Yeung, Sophie E.

2017-01-01

Background Hypertension guidelines recommend home blood pressure (HBP) monitoring in adjunct to office blood pressure (OBP) for its greater reproducibility and prognostic utility in the prevention of cardiovascular outcomes, especially stroke. To date, the relationship between HBP and cognitive function remains unexplored. Methods We examined HBP as a cognitive predictor in a multi-ethnic group of community-dwelling adults aged 60 and over (N = 133) using neuropsychological measures and analyzed the data using multiple regression analyses. We also employed “everyday cognition” measures that have been found to have higher prognostic utility for real-world functioning than traditional cognitive tasks. Results Good to perfect HBP monitoring compliance over seven days was achieved by 88.7% of the participants with superior reliability (ICC≥.96) to office readings. Higher home systolic BP and pulse pressure predicted worse processing speed, executive function, and everyday cognitive function, whereas lower home diastolic BP predicted worse everyday cognition. Office readings were similarly associated with everyday cognitive function but with no other cognitive measures. Conclusion Our findings are the first to validate HBP as a predictor of neuropsychological function in older adults beyond cognitive screening. Differential relationships among blood pressure variables and specific cognitive domains were observed. With proper standardization and training, we demonstrated that HBP can be obtained in a multi-ethnic community-dwelling older adult cohort. Our findings emphasize the importance of employing blood pressure and cognitive measures that are adequately sensitive to detect vascular-related cognitive impairment in a relatively healthy population. Implications regarding proper HBP measurement for hypertension management, cognitive health, and everyday function are discussed. PMID:28520751

Effect of Intensive Blood-Pressure Treatment on Patient-Reported Outcomes.

PubMed

Berlowitz, Dan R; Foy, Capri G; Kazis, Lewis E; Bolin, Linda P; Conroy, Molly B; Fitzpatrick, Peter; Gure, Tanya R; Kimmel, Paul L; Kirchner, Kent; Morisky, Donald E; Newman, Jill; Olney, Christine; Oparil, Suzanne; Pajewski, Nicholas M; Powell, James; Ramsey, Thomas; Simmons, Debra L; Snyder, Joni; Supiano, Mark A; Weiner, Daniel E; Whittle, Jeff

2017-08-24

The previously published results of the Systolic Blood Pressure Intervention Trial showed that among participants with hypertension and an increased cardiovascular risk, but without diabetes, the rates of cardiovascular events were lower among those who were assigned to a target systolic blood pressure of less than 120 mm Hg (intensive treatment) than among those who were assigned to a target of less than 140 mm Hg (standard treatment). Whether such intensive treatment affected patient-reported outcomes was uncertain; those results from the trial are reported here. We randomly assigned 9361 participants with hypertension to a systolic blood-pressure target of less than 120 mm Hg or a target of less than 140 mm Hg. Patient-reported outcome measures included the scores on the Physical Component Summary (PCS) and Mental Component Summary (MCS) of the Veterans RAND 12-Item Health Survey, the Patient Health Questionnaire 9-item depression scale (PHQ-9), patient-reported satisfaction with their blood-pressure care and blood-pressure medications, and adherence to blood-pressure medications. We compared the scores in the intensive-treatment group with those in the standard-treatment group among all participants and among participants stratified according to physical and cognitive function. Participants who received intensive treatment received an average of one additional antihypertensive medication, and the systolic blood pressure was 14.8 mm Hg (95% confidence interval, 14.3 to 15.4) lower in the group that received intensive treatment than in the group that received standard treatment. Mean PCS, MCS, and PHQ-9 scores were relatively stable over a median of 3 years of follow-up, with no significant differences between the two treatment groups. No significant differences between the treatment groups were noted when participants were stratified according to baseline measures of physical or cognitive function. Satisfaction with blood-pressure care was high in both treatment groups, and we found no significant difference in adherence to blood-pressure medications. Patient-reported outcomes among participants who received intensive treatment, which targeted a systolic blood pressure of less than 120 mm Hg, were similar to those among participants who received standard treatment, including among participants with decreased physical or cognitive function. (Funded by the National Institutes of Health; SPRINT ClinicalTrials.gov number, NCT01206062 .).

A U-shaped Association between Blood Pressure and Cognitive Impairment in Chinese Elderly

PubMed Central

Lv, Yue-Bin; Zhu, Peng-Fei; Yin, Zhao-Xue; Kraus, Virginia Byers; Threapleton, Diane; Chei, Choy-Lye; Brasher, Melanie Sereny; Zhang, Juan; Qian, Han-Zhu; Mao, Chen; Matchar, David Bruce; Luo, Jie-Si; Zeng, Yi; Shi, Xiao-Ming

2017-01-01

Objectives Higher or lower blood pressure may relate to cognitive impairment, while the relationship between blood pressure and cognitive impairment among the elderly is not well-studied. The study objective was to determine whether blood pressure is associated with cognitive impairment in the elderly, and, if so, to accurately describe the association. Design Cross-sectional data from the sixth wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) conducted in 2011 Setting Community-based setting in longevity areas in China Participants 7,144 Chinese elderly aged 65 years and older were included in the sample Measures Systolic blood pressures (SBP) and diastolic blood pressures (DBP) were measured, pulse pressure (PP) was calculated as (SBP)-(DBP) and mean arterial pressures (MAP) was calculated as 1/3(SBP) + 2/3(DBP). Cognitive function was assessed via a validated Mini-Mental State Examination (MMSE). Results Based on the results of generalized additive models (GAMs), U-shaped associations were identified between cognitive impairment and SBP, DBP, PP and MAP. The cut-points at which risk for cognitive impairment (MMSE<24) was minimized were determined by quadratic models as 141 mmHg, 85 mmHg, 62 mmHg and 103 mmHg, respectively. In the logistic models, U-shaped associations remained for SBP, DBP, and MAP but not PP. Below the identified cut-points, each 1mmHg decrease in blood pressure corresponded to 0.7%, 1.1%, and 1.1% greater risk in the risk of cognitive impairment, respectively. Above the cut-points, each 1mmHg increase in blood pressure corresponded to 1.2%, 1.8%, and 2.1% greater risk of cognitive impairment for SBP, DBP and MAP, respectively. Conclusion A U-shaped association between blood pressure and cognitive function in an elderly Chinese population was found. Recognition of these instances is important identifying the high-risk population for cognitive impairment and to individualize blood pressure management for cognitive impairment prevention. PMID:28126139

Genome-wide association analysis identifies novel blood pressure loci and offers biological insights into cardiovascular risk.

PubMed

Warren, Helen R; Evangelou, Evangelos; Cabrera, Claudia P; Gao, He; Ren, Meixia; Mifsud, Borbala; Ntalla, Ioanna; Surendran, Praveen; Liu, Chunyu; Cook, James P; Kraja, Aldi T; Drenos, Fotios; Loh, Marie; Verweij, Niek; Marten, Jonathan; Karaman, Ibrahim; Lepe, Marcelo P Segura; O'Reilly, Paul F; Knight, Joanne; Snieder, Harold; Kato, Norihiro; He, Jiang; Tai, E Shyong; Said, M Abdullah; Porteous, David; Alver, Maris; Poulter, Neil; Farrall, Martin; Gansevoort, Ron T; Padmanabhan, Sandosh; Mägi, Reedik; Stanton, Alice; Connell, John; Bakker, Stephan J L; Metspalu, Andres; Shields, Denis C; Thom, Simon; Brown, Morris; Sever, Peter; Esko, Tõnu; Hayward, Caroline; van der Harst, Pim; Saleheen, Danish; Chowdhury, Rajiv; Chambers, John C; Chasman, Daniel I; Chakravarti, Aravinda; Newton-Cheh, Christopher; Lindgren, Cecilia M; Levy, Daniel; Kooner, Jaspal S; Keavney, Bernard; Tomaszewski, Maciej; Samani, Nilesh J; Howson, Joanna M M; Tobin, Martin D; Munroe, Patricia B; Ehret, Georg B; Wain, Louise V

2017-03-01

Elevated blood pressure is the leading heritable risk factor for cardiovascular disease worldwide. We report genetic association of blood pressure (systolic, diastolic, pulse pressure) among UK Biobank participants of European ancestry with independent replication in other cohorts, and robust validation of 107 independent loci. We also identify new independent variants at 11 previously reported blood pressure loci. In combination with results from a range of in silico functional analyses and wet bench experiments, our findings highlight new biological pathways for blood pressure regulation enriched for genes expressed in vascular tissues and identify potential therapeutic targets for hypertension. Results from genetic risk score models raise the possibility of a precision medicine approach through early lifestyle intervention to offset the impact of blood pressure-raising genetic variants on future cardiovascular disease risk.

Genome-wide association analysis identifies novel blood pressure loci and offers biological insights into cardiovascular risk

PubMed Central

Ntalla, Ioanna; Surendran, Praveen; Liu, Chunyu; Cook, James P; Kraja, Aldi T; Drenos, Fotios; Loh, Marie; Verweij, Niek; Marten, Jonathan; Karaman, Ibrahim; Segura Lepe, Marcelo P; O’Reilly, Paul F; Knight, Joanne; Snieder, Harold; Kato, Norihiro; He, Jiang; Tai, E Shyong; Said, M Abdullah; Porteous, David; Alver, Maris; Poulter, Neil; Farrall, Martin; Gansevoort, Ron T; Padmanabhan, Sandosh; Mägi, Reedik; Stanton, Alice; Connell, John; Bakker, Stephan J L; Metspalu, Andres; Shields, Denis C; Thom, Simon; Brown, Morris; Sever, Peter; Esko, Tõnu; Hayward, Caroline; van der Harst, Pim; Saleheen, Danish; Chowdhury, Rajiv; Chambers, John C; Chasman, Daniel I; Chakravarti, Aravinda; Newton-Cheh, Christopher; Lindgren, Cecilia M; Levy, Daniel; Kooner, Jaspal S; Keavney, Bernard; Tomaszewski, Maciej; Samani, Nilesh J; Howson, Joanna M M; Tobin, Martin D; Munroe, Patricia B; Ehret, Georg B; Wain, Louise V

2017-01-01

Elevated blood pressure is the leading heritable risk factor for cardiovascular disease worldwide. We report genetic association of blood pressure (systolic, diastolic, pulse pressure) among UK Biobank participants of European ancestry with independent replication in other cohorts, and robust validation of 107 independent loci. We also identify new independent variants at 11 previously reported blood pressure loci. Combined with results from a range of in silico functional analyses and wet bench experiments, our findings highlight new biological pathways for blood pressure regulation enriched for genes expressed in vascular tissues and identify potential therapeutic targets for hypertension. Results from genetic risk score models raise the possibility of a precision medicine approach through early lifestyle intervention to offset the impact of blood pressure raising genetic variants on future cardiovascular disease risk. PMID:28135244

[Oxygen-transporting function of the blood circulation system in sevoflurane anesthesia during myocardial revascularization under extracorporeal circulation].

PubMed

Skopets, A A; Lomivorotov, V V; Karakhalis, N B; Makarov, A A; Duman'ian, E S; Lomivorotova, L V

2009-01-01

The purpose of the study was to evaluate the efficiency of oxygen-transporting function of the circulatory system under sevoflurane anesthesia during myocardial revascularization operations under extracorporeal circulation. Twenty-five patients with coronary heart disease were examined. Mean blood pressure, heart rate, cardiac index, total peripheral vascular resistance index, pulmonary pressure, pulmonary wedge pressure, and central venous pressure were measured. Arterial and mixed venous blood oxygen levels, oxygen delivery and consumption index, arteriovenous oxygen difference, and glucose and lactate concentrations were calculated. The study has demonstrated that sevoflurane is an effective and safe anesthetic for myocardial revascularization operations in patients with coronary heart disease. The use of sevoflurane contributes to steady-state oxygen-transporting function of the circulatory system at all surgical stages.

Improved lipids, diastolic pressure and kidney function are potential contributors to familial longevity: a study on 60 Chinese centenarian families.

PubMed

He, Yong-Han; Pu, Shao-Yan; Xiao, Fu-Hui; Chen, Xiao-Qiong; Yan, Dong-Jing; Liu, Yao-Wen; Lin, Rong; Liao, Xiao-Ping; Yu, Qin; Yang, Li-Qin; Yang, Xing-Li; Ge, Ming-Xia; Li, Ying; Jiang, Jian-Jun; Cai, Wang-Wei; Kong, Qing-Peng

2016-02-25

Centenarians are a good healthy aging model. Interestingly, centenarians' offspring are prone to achieve longevity. Here we recruited 60 longevity families and investigated the blood biochemical indexes of family members to seek candidate factors associated with familial longevity. First, associations of blood indexes with age were tested. Second, associations of blood parameters in centenarians (CEN) with their first generation of offspring (F1) and F1 spouses (F1SP) were analyzed. Third, genes involved in regulating target factors were investigated. We found that total cholesterol (TC) and triglyceride (TG) increased with age (20-80 years), but decreased in CEN. Similarly, blood urea nitrogen (BUN) and blood creatinine (BCr) increased with age (20-80 years), but were maintained on a plateau in CEN. Importantly, we first revealed dual changes in blood pressure, i.e., decreased diastolic blood pressure but increased systolic blood pressure in CEN, which associated with altered CST3 expression. Genetic analysis revealed a significant association of blood uric acid (BUA) and BCr in CEN with F1 but not with F1SP, suggesting they may be heritable traits. Taken together, our results suggest serum lipids, kidney function and especially diastolic pressure rather than systolic pressure were improved in CEN or their offspring, suggesting these factors may play an important role in familial longevity.

Sensing of blood pressure increase by transient receptor potential vanilloid 1 receptors on baroreceptors.

PubMed

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N; Pan, Hui-Lin

2009-12-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling revealed that TRPV1 immunoreactivity was present on nerve fibers and terminals in the adventitia of the ascending aorta and aortic arch, the nodose ganglion neurons, and afferent fibers in the solitary tract of the brainstem. RTX treatment eliminated TRPV1 immunoreactivities in the aorta, nodose ganglion, and solitary tract. Renal sympathetic nerve activity, blood pressure, and heart rate were recorded in anesthetized rats. The baroreflex was triggered by lowering and raising blood pressure through intravenous infusion of sodium nitroprusside and phenylephrine, respectively. Inhibition of sympathetic nerve activity and heart rate by the phenylephrine-induced increase in blood pressure was largely impaired in RTX-treated rats. The maximum gain of the baroreflex function was significantly lower in RTX-treated than vehicle-treated rats. Furthermore, blocking of TRPV1 receptors significantly blunted the baroreflex and decreased the maximum gain of baroreflex function in the high blood pressure range. Our findings provide important new information that TRPV1 is expressed along the entire baroreceptive afferent pathway. TRPV1 receptors expressed on baroreceptive nerve endings can function as mechanoreceptors to detect the increase in blood pressure and maintain the homoeostasis.

Sensing of Blood Pressure Increase by Transient Receptor Potential Vanilloid 1 Receptors on Baroreceptors

PubMed Central

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N.

2009-01-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling revealed that TRPV1 immunoreactivity was present on nerve fibers and terminals in the adventitia of the ascending aorta and aortic arch, the nodose ganglion neurons, and afferent fibers in the solitary tract of the brainstem. RTX treatment eliminated TRPV1 immunoreactivities in the aorta, nodose ganglion, and solitary tract. Renal sympathetic nerve activity, blood pressure, and heart rate were recorded in anesthetized rats. The baroreflex was triggered by lowering and raising blood pressure through intravenous infusion of sodium nitroprusside and phenylephrine, respectively. Inhibition of sympathetic nerve activity and heart rate by the phenylephrine-induced increase in blood pressure was largely impaired in RTX-treated rats. The maximum gain of the baroreflex function was significantly lower in RTX-treated than vehicle-treated rats. Furthermore, blocking of TRPV1 receptors significantly blunted the baroreflex and decreased the maximum gain of baroreflex function in the high blood pressure range. Our findings provide important new information that TRPV1 is expressed along the entire baroreceptive afferent pathway. TRPV1 receptors expressed on baroreceptive nerve endings can function as mechanoreceptors to detect the increase in blood pressure and maintain the homoeostasis. PMID:19726694

A longitudinal study of altered taste and smell perception and change in blood pressure.

PubMed

Liu, Y-H; Huang, Z; Vaidya, A; Li, J; Curhan, G C; Wu, S; Gao, X

2018-05-29

Previous studies suggest that olfactory receptors, which mediate smell chemosensation, are located in the kidney and involved in blood pressure regulation. Mammalian epithelial sodium channels located in taste receptor cells are also found to participate in blood pressure regulation. However, there is currently no human study that has examined the association between taste and smell function and blood pressure. We thus conducted a longitudinal study to examine whether participants with altered taste and smell perception had larger increases in blood pressure compared with those without altered perception in a community-based cohort. The study included 5190 Chinese adults (4058 men and 1132 women) who were normotensive at baseline. Taste and smell perception were assessed via questionnaire in 2012 (baseline). Blood pressure was measured in 2012 and 2014 to determine relative change in blood pressure. Mean differences of 2-year blood pressure change and 95% confidence intervals (CIs) across four categories of taste and smell perception were calculated after adjusting for known risk factors for hypertension. After adjusting for potential confounders, individuals with altered taste and smell perception had larger increases in systolic blood pressure (adjusted mean difference = 5.1 mmHg, 95% CI: 0.1-10.0, p-value: 0.04) and mean arterial pressure (adjusted mean difference = 3.8 mmHg, 95% CI: 0.4-7.1, p-value: 0.03) after two years of follow-up compared with those having neither altered taste nor altered smell perception. No significant association was observed in individuals with altered taste or smell perception only. Our results suggest an association between chemosensory function and blood pressure. Copyright © 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Effect of maternal diabetes on female offspring

PubMed Central

Martins, Juliana de Oliveira; Panício, Maurício Isaac; Dantas, Marcos Paulo Suehiro; Gomes, Guiomar Nascimento

2014-01-01

Objective To evaluate the effect of maternal diabetes on the blood pressure and kidney function of female offspring, as well as if such changes exacerbate during pregnancy. Methods Diabetes mellitus was induced in female rats with the administration of streptozotocin in a single dose, one week before mating. During pregnancy, blood pressure was measured through plethysmography. On the 20th day of pregnancy, the animals were placed for 24 hours in metabolic cages to obtain urine samples. After the animals were removed from the cages, blood samples were withdrawn. One month after pregnancy, new blood and urine sample were collected. Kidney function was evaluated through proteinuria, plasma urea, plasma creatinine, creatinine excretion rate, urinary flow, and creatinine clearance. Results The female offspring from diabetic mothers showed an increase in blood pressure, and a decrease in glomerular filtration rate in relation to the control group. Conclusion Hyperglycemia during pregnancy was capable of causing an increase in blood pressure and kidney dysfunction in the female offspring. PMID:25628190

Effect of consuming a purple-fleshed sweet potato beverage on health-related biomarkers and safety parameters in Caucasian subjects with elevated levels of blood pressure and liver function biomarkers: a 4-week, open-label, non-comparative trial

PubMed Central

OKI, Tomoyuki; KANO, Mitsuyoshi; WATANABE, Osamu; GOTO, Kazuhisa; BOELSMA, Esther; ISHIKAWA, Fumiyasu; SUDA, Ikuo

2016-01-01

An open-label study with one treatment arm was conducted to investigate changes in health-related biomarkers (blood pressure and liver enzyme activity) and the safety of 4 weeks of consuming a purple-fleshed sweet potato beverage in Caucasian subjects. Twenty healthy adults, 18–70 years of age, with a body mass index >25 kg/m2, elevated blood pressure and elevated levels of liver function biomarkers consumed two cartons of purple-fleshed sweet potato beverage (125 ml, including 117 mg anthocyanin per carton) daily for 4 weeks. Hematology, serum clinical profile, dipstick urinalysis and blood pressure were determined before consumption, at 2 and 4 weeks of consumption and after a 2-week washout period. A trend was found toward lowering systolic blood pressure during the treatment period (p=0.0590). No significant changes were found in diastolic blood pressure throughout the study period. Systolic blood pressure was significantly lower after 4 weeks of consumption compared with before consumption (p=0.0125) and was significantly higher after the 2-week washout period compared with after consumption (p=0.0496). The serum alanine aminotransferase level significantly increased over time, but aspartate aminotransferase and γ-glutamyltransferase levels stayed within the normal range of reference values. Safety parameters of the blood and urine showed no clinically relevant changes. The consumption of a purple-fleshed sweet potato beverage for 4 weeks resulted in no clinically relevant changes in safety parameters of the blood and urine and showed a trend toward lowering systolic blood pressure. PMID:27508114

Application of Acute Maximal Exercise to Enhance Mechanisms Underlying Blood Pressure Regulation and Orthostatic Tolerance After Exposure to Simulated Microgravity

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Engelke, K. A.; Doerr, D. F.

1999-01-01

Development of orthostatic hypotension and intolerance in astronauts who return to earth following a spaceflight mission represents a significant operational concern to NASA. Reduced plasma volume, vascular resistance, and baroreflex responsiveness following exposure to actual and ground-based analogs of microgravity have been associated with orthostatic instability, suggesting that these mechanisms may contribute alone or in combination to compromise of blood pressure regulation after spaceflight. It therefore seems reasonable that development of procedures designed to reverse or restore the effects of microgravity on regulatory mechanisms of blood volume, vascular resistance and cardiac function should provide some protection against postflight orthostatic intolerance. Several investigations have provided evidence that a single bout of exhaustive dynamic exercise enhances functions of mechanisms responsible for blood pressure stability. Therefore, the purpose of our research project was to conduct a series of experiments using ground-based analogs of reduced gravity (i.e., prolonged restriction to the upright standing posture) in human subjects to investigate the hypothesis that a single bout of dynamic maximal exercise would restore blood volume, vascular resistance and cardiac function and improve blood pressure stability.

The effects of long-chain omega-3 fish oils and multivitamins on cognitive and cardiovascular function: a randomized, controlled clinical trial.

PubMed

Pase, Matthew P; Grima, Natalie; Cockerell, Robyn; Stough, Con; Scholey, Andrew; Sali, Avni; Pipingas, Andrew

2015-01-01

Fish oils and multivitamins are two of the most commonly used dietary supplements. Fish oil use may reduce vascular risk factors associated with cognitive decline, thus providing benefits to both heart and brain health. Multivitamins may also have direct effects on brain function. The present study investigated the effects of fish oil, with and without the addition of a multivitamin, on cognitive and cardiovascular function. In a randomized, placebo-controlled, double-blind fashion, 160 healthy adults aged 50-70 years were randomized to receive either 3 g of fish oil (240 mg eicosapentaenoic acid [EPA] + 240 mg docosahexaenoic acid [DHA]) with a multivitamin, 6 g of fish oil (480 mg EPA + 480 mg DHA) with a multivitamin, or 6 g of fish oil without a multivitamin or a placebo. Cognitive performance, brachial blood pressure, and aortic (central) blood pressure were measured at baseline, 6 weeks, and 16 weeks. Treatment allocation had no effect on the primary cognitive outcomes at endpoint. Absolute increases in the red blood cell omega-3/6 ratio were associated with improvements in spatial working memory. The group receiving 6 g fish oil without the multivitamin displayed a significant decrease in aortic pulse pressure and aortic augmentation pressure, two measures of aortic blood pressure and aortic stiffness. Fish oil decreased aortic pulse pressure and augmentation pressure. Reductions in aortic blood pressure were not accompanied by consistent improvements in cognition.

The Impact of Exercising During Haemodialysis on Blood Pressure, Markers of Cardiac Injury and Systemic Inflammation--Preliminary Results of a Pilot Study.

PubMed

Dungey, Maurice; Bishop, Nicolette C; Young, Hannah M L; Burton, James O; Smith, Alice C

2015-01-01

Patients requiring haemodialysis have cardiovascular and immune dysfunction. Little is known about the acute effects of exercise during haemodialysis. Exercise has numerous health benefits but in other populations has a profound impact upon blood pressure, inflammation and immune function; therefore having the potential to exacerbate cardiovascular and immune dysfunction in this vulnerable population. Fifteen patients took part in a randomised-crossover study investigating the effect of a 30-min bout of exercise during haemodialysis compared to resting haemodialysis. We assessed blood pressure, plasma markers of cardiac injury and systemic inflammation and neutrophil degranulation. Exercise increased blood pressure immediately post-exercise; however, 1 hour after exercise blood pressure was lower than resting levels (106±22 vs. 117±25 mm Hg). No differences in h-FABP, cTnI, myoglobin or CKMB were observed between trial arms. Exercise did not alter circulating concentrations of IL-6, TNF-α or IL-1ra nor clearly suppress neutrophil function. This study demonstrates fluctuations in blood pressure during haemodialysis in response to exercise. However, since the fall in blood pressure occurred without evidence of cardiac injury, we regard it as a normal response to exercise superimposed onto the haemodynamic response to haemodialysis. Importantly, exercise did not exacerbate systemic inflammation or immune dysfunction; intradialytic exercise was well tolerated. © 2015 The Author(s) Published by S. Karger AG, Basel.

Dysfunctional vestibular system causes a blood pressure drop in astronauts returning from space

PubMed Central

Hallgren, Emma; Migeotte, Pierre-François; Kornilova, Ludmila; Delière, Quentin; Fransen, Erik; Glukhikh, Dmitrii; Moore, Steven T.; Clément, Gilles; Diedrich, André; MacDougall, Hamish; Wuyts, Floris L.

2015-01-01

It is a challenge for the human body to maintain stable blood pressure while standing. The body’s failure to do so can lead to dizziness or even fainting. For decades it has been postulated that the vestibular organ can prevent a drop in pressure during a position change – supposedly mediated by reflexes to the cardiovascular system. We show – for the first time – a significant correlation between decreased functionality of the vestibular otolith system and a decrease in the mean arterial pressure when a person stands up. Until now, no experiments on Earth could selectively suppress both otolith systems; astronauts returning from space are a unique group of subjects in this regard. Their otolith systems are being temporarily disturbed and at the same time they often suffer from blood pressure instability. In our study, we observed the functioning of both the otolith and the cardiovascular system of the astronauts before and after spaceflight. Our finding indicates that an intact otolith system plays an important role in preventing blood pressure instability during orthostatic challenges. Our finding not only has important implications for human space exploration; they may also improve the treatment of unstable blood pressure here on Earth. PMID:26671177

Experiments on Factors That Influence Muscular Function in Man.

DTIC Science & Technology

1983-05-25

of phentolamine or phenylephrine did not affect the increase in mean arterial blood pressure , which reached the same high levels at fatigue in all...CLASSIFICATION OF THIS PAGE(Whon Date Elrered) same when the contractions result in muscular fatigue, at which time the mean . blood pressure is the same as it is...arterial blood pressure of bout 150 mmHg at the point of muscular fatigue. Clearly, some vaso- constrictp> response was intervening since the blood flow

Is there a functional neural correlate of individual differences in cardiovascular reactivity?

PubMed

Gianaros, Peter J; May, J Christopher; Siegle, Greg J; Jennings, J Richard

2005-01-01

The present study tested whether individuals who differ in the magnitude of their blood pressure reactions to a behavioral stressor also differ in their stressor-induced patterns of functional neural activation. Sixteen participants (7 men, 9 women aged 47 to 72 years) were classified as high (n = 8) or low (n = 8) blood pressure reactors by the magnitude and temporal consistency of their systolic blood pressure (SBP) reaction to a Stroop color-word interference stressor. Both high and low SBP reactors completed this Stroop stressor while their task-related changes in blood pressure and functional neural activity were assessed in a blocked functional magnetic resonance imaging design. In both high and low SBP reactors, the Stroop-stressor engaged the anterior cingulate, orbitofrontal, insular, posterior parietal, and the dorsolateral prefrontal regions of the cortex, the thalamus, and the cerebellum. Compared with low reactors, however, high reactors not only showed a larger magnitude increase in SBP to the Stroop stressor, but also an increased activation of the posterior cingulate cortex. A behavioral stressor that is used widely in cardiovascular reactivity research, the Stroop stressor, engages brain systems that are thought to support both stressor processing and cardiovascular reactivity. Increased activation of the posterior cingulate, a brain region implicated in vigilance to the environment and evaluative emotional processes, may be a functional neural correlate of an individual's tendency to show large-magnitude (exaggerated) blood pressure reactions to behavioral stressors.

Peritonitis - secondary

MedlinePlus

... blood pressure. Tests may include: Blood culture Blood chemistry, including pancreatic enzymes Complete blood count Liver and kidney function tests X-rays or CT scan Peritoneal fluid culture Urinalysis

Tissue-specific expression of transgenic secreted ACE in vasculature can restore normal kidney functions, but not blood pressure, of Ace-/- mice.

PubMed

Chattopadhyay, Saurabh; Kessler, Sean P; Colucci, Juliana Almada; Yamashita, Michifumi; Senanayake, Preenie deS; Sen, Ganes C

2014-01-01

Angiotensin-converting enzyme (ACE) regulates normal blood pressure and fluid homeostasis through its action in the renin-angiotensin-system (RAS). Ace-/- mice are smaller in size, have low blood pressure and defective kidney structure and functions. All of these defects are cured by transgenic expression of somatic ACE (sACE) in vascular endothelial cells of Ace-/- mice. sACE is expressed on the surface of vascular endothelial cells and undergoes a natural cleavage secretion process to generate a soluble form in the body fluids. Both the tissue-bound and the soluble forms of ACE are enzymatically active, and generate the vasoactive octapeptide Angiotensin II (Ang II) with equal efficiency. To assess the relative physiological roles of the secreted and the cell-bound forms of ACE, we expressed, in the vascular endothelial cells of Ace-/- mice, the ectodomain of sACE, which corresponded to only the secreted form of ACE. Our results demonstrated that the secreted form of ACE could normalize kidney functions and RAS integrity, growth and development of Ace-/- mice, but not their blood pressure. This study clearly demonstrates that the secreted form of ACE cannot replace the tissue-bound ACE for maintaining normal blood pressure; a suitable balance between the tissue-bound and the soluble forms of ACE is essential for maintaining all physiological functions of ACE.

Tissue-Specific Expression of Transgenic Secreted ACE in Vasculature Can Restore Normal Kidney Functions, but Not Blood Pressure, of Ace-/- Mice

PubMed Central

Chattopadhyay, Saurabh; Kessler, Sean P.; Colucci, Juliana Almada; Yamashita, Michifumi; Senanayake, Preenie deS; Sen, Ganes C.

2014-01-01

Angiotensin-converting enzyme (ACE) regulates normal blood pressure and fluid homeostasis through its action in the renin-angiotensin-system (RAS). Ace-/- mice are smaller in size, have low blood pressure and defective kidney structure and functions. All of these defects are cured by transgenic expression of somatic ACE (sACE) in vascular endothelial cells of Ace-/- mice. sACE is expressed on the surface of vascular endothelial cells and undergoes a natural cleavage secretion process to generate a soluble form in the body fluids. Both the tissue-bound and the soluble forms of ACE are enzymatically active, and generate the vasoactive octapeptide Angiotensin II (Ang II) with equal efficiency. To assess the relative physiological roles of the secreted and the cell-bound forms of ACE, we expressed, in the vascular endothelial cells of Ace-/- mice, the ectodomain of sACE, which corresponded to only the secreted form of ACE. Our results demonstrated that the secreted form of ACE could normalize kidney functions and RAS integrity, growth and development of Ace-/- mice, but not their blood pressure. This study clearly demonstrates that the secreted form of ACE cannot replace the tissue-bound ACE for maintaining normal blood pressure; a suitable balance between the tissue-bound and the soluble forms of ACE is essential for maintaining all physiological functions of ACE. PMID:24475296

Blood pressure and cognitive function: a prospective analysis among adolescents in the Seychelles

PubMed Central

Lyngdoh, Tanica; Viswanathan, Bharathi; Kobrosly, Roni; van Wijngaarden, Edwin; Huber, Brittany; Davidson, Philip W.; Cory-Slechta, Deborah A.; Strain, JJ; Myers, Gary J.; Bovet, Pascal

2013-01-01

Objective An inverse relationship between blood pressure and cognitive function has been found in adults, but limited data are available in adolescents and young adults. We examined the prospective relation between blood pressure and cognitive function in adolescence. Methods We examined the association between BP measured at the ages of 12–15 years in school surveys and cognitive endpoints measured in the Seychelles Child Development Study at ages 17 (n=407) and 19 (n=429) years, respectively. We evaluated multiple domains of cognition based on subtests of the Cambridge Neurological Test Automated Battery (CANTAB), the Woodcock Johnson Test of Scholastic Achievement (WJTA), the Finger Tapping test (FT) and the Kaufman Brief Intelligence Test (K-BIT). We used age-, sex- and height-specific z-scores of systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP). Results Six out of the 21 cognitive endpoints tested were associated with BP. However, none of these associations were found to hold for both males and females or for different subtests within the same neurodevelopmental domain or for both SBP and DBP. Most of these associations disappeared when analyses were adjusted for selected potential confounding factors such as socio-economic status, birth weight, gestational age, body mass index, alcohol consumption, blood glucose, and total n-3 and n-6 polyunsaturated fats. Conclusions Our findings do not support a consistent association between BP and subsequent performance on tests assessing various cognitive domains in adolescents. PMID:23572201

Renal blood flow dynamics in inbred rat strains provides insight into autoregulation.

PubMed

A Mitrou, Nicholas G; Cupples, William A

2014-01-01

Renal autoregulation maintains stable renal blood flow in the face of constantly fluctuating blood pressure. Autoregulation is also the only mechanism that protects the delicate glomerular capillaries when blood pressure increases. In order to understand autoregulation, the renal blood flow response to changing blood pressure is studied. The steadystate response of blood flow is informative, but limits investigation of the individual mechanisms of autoregulation. The dynamics of autoregulation can be probed with transfer function analysis. The frequency-domain analysis of autoregulation allows investigators to probe the relative activity of each mechanism of autoregulation. We discuss the methodology and interpretation of transfer function analysis. Autoregulation is routinely studied in the rat, of which there are many inbred strains. There are multiple strains of rat that are either selected or inbred as models of human pathology. We discuss relevant characteristics of Brown Norway, Spontaneously hypertensive, Dahl, and Fawn-Hooded hypertensive rats and explore differences among these strains in blood pressure, dynamic autoregulation, and susceptibility to hypertensive renal injury. Finally we show that the use of transfer function analysis in these rat strains has contributed to our understanding of the physiology and pathophysiology of autoregulation and hypertensive renal disease.Interestingly all these strains demonstrate effective tubuloglomerular feedback suggesting that this mechanism is not sufficient for effective autoregulation. In contrast, obligatory or conditional failure of the myogenic mechanism suggests that this component is both necessary and sufficient for autoregulation.

Beat-to-beat blood pressure analysis after premature ventricular contraction indicates sensitive baroreceptor dysfunction in Parkinson's disease.

PubMed

Haensch, Carl-Albrecht; Jörg, Johannes

2006-04-01

Extrasystoles occur in normal subjects but are significant more frequently (16.25% vs. 55%; chi(2) = 19.3; P < 0.001) seen in Parkinson's disease (PD) patients. The extrasystolic decreases in stroke volume and systolic pressure activate sympathetic vasomotor innervation and lead to a blood pressure increase for a few heartbeats. The purpose of this study was to prove whether the short time analysis of this blood pressure regulation allows the assessment of sympathetic neurocirculatory function. Records of noninvasive blood pressure monitoring were reviewed from 40 PD patients and 80 controls. A battery of cardiovascular autonomic tests, including Valsalva maneuver, tilt-table testing, echocardiography, and cardiac scintigraphy with [(123)I]meta-iodobenzylguanidine were performed. Fifty-five percent of the PD patients had at least one premature ventricular contraction (PVC) in 10 minutes lying supine at rest. After every PVC (13 PVCs) recorded from normal subjects, we found an increase in systolic blood pressure above base line with a maximum at the seventh heart beat. In all of the 22 PD patients, the systolic blood pressure was significantly decreased less than baseline in every PVC from the second to the ninth postextrasystolic beat (P < 0.001). In both groups, the extrasystolic fall in blood pressure was on average approximately 22%. The postextrasystolic potentiation did not differ (5.3% vs. 4.4%, not significant). If a PVC occurs, the analysis of short-time blood pressure regulation is a sensitive tool for baroreceptor reflex function. The advantage of this method results from the independence of patients cooperation and the high sensitivity to prove a sympathetic neurocirculatory failure within 10 heart beats. Copyright 2005 Movement Disorder Society.

Cholecalciferol treatment to reduce blood pressure in older patients with isolated systolic hypertension: the VitDISH randomized controlled trial.

PubMed

Witham, Miles D; Price, Rosemary J G; Struthers, Allan D; Donnan, Peter T; Messow, Claudia-Martina; Ford, Ian; McMurdo, Marion E T

2013-10-14

Observational data link low 25-hydroxyvitamin D levels to both prevalent blood pressure and incident hypertension. No clinical trial has yet examined the effect of vitamin D supplementation in isolated systolic hypertension, the most common pattern of hypertension in older people. To test whether high-dose, intermittent cholecalciferol supplementation lowers blood pressure in older patients with isolated systolic hypertension. Parallel group, double-blind, placebo-controlled randomized trial. Primary care clinics and hospital clinics. Patients 70 years and older with isolated systolic hypertension (supine systolic blood pressure >140 mm Hg and supine diastolic blood pressure <90 mm Hg) and baseline 25-hydroxyvitamin D levels less than 30 ng/mL were randomized into the trial from June 1, 2009, through May 31, 2011. A total of 100,000 U of oral cholecalciferol or matching placebo every 3 months for 1 year. Difference in office blood pressure, 24-hour blood pressure, arterial stiffness, endothelial function, cholesterol level, insulin resistance, and b-type natriuretic peptide level during 12 months. A total of 159 participants were randomized (mean age, 77 years). Mean baseline office systolic blood pressure was 163/78 mm Hg. Mean baseline 25-hydroxyvitamin D level was 18 ng/mL. 25-Hydroxyvitamin D levels increased in the treatment group compared with the placebo group (+8 ng/mL at 1 year, P < .001). No significant treatment effect was seen for mean (95% CI) office blood pressure (−1 [−6 to 4]/−2 [−4 to 1] mm Hg at 3 months and 1 [−2 to 4]/0 [−2 to 2] mm Hg overall treatment effect). No significant treatment effect was evident for any of the secondary outcomes (24-hour blood pressure, arterial stiffness, endothelial function, cholesterol level, glucose level, and walking distance). There was no excess of adverse events in the treatment group, and the total number of falls was nonsignificantly lower in the group receiving vitamin D (36 vs 46, P = .24). Vitamin D supplementation did not improve blood pressure or markers of vascular health in older patients with isolated systolic hypertension. isrctn.org Identifier: ISRCTN92186858.

Oscillatory lower body negative pressure impairs working memory task-related functional hyperemia in healthy volunteers.

PubMed

Merchant, Sana; Medow, Marvin S; Visintainer, Paul; Terilli, Courtney; Stewart, Julian M

2017-04-01

Neurovascular coupling (NVC) describes the link between an increase in task-related neural activity and increased cerebral blood flow denoted "functional hyperemia." We previously showed induced cerebral blood flow oscillations suppressed functional hyperemia; conversely functional hyperemia also suppressed cerebral blood flow oscillations. We used lower body negative pressure (OLBNP) oscillations to force oscillations in middle cerebral artery cerebral blood flow velocity (CBFv). Here, we used N-back testing, an intellectual memory challenge as a neural activation task, to test the hypothesis that OLBNP-induced oscillatory cerebral blood flow can reduce functional hyperemia and NVC produced by a working memory task and can interfere with working memory. We used OLBNP (-30 mmHg) at 0.03, 0.05, and 0.10 Hz and measured spectral power of CBFv at all frequencies. Neither OLBNP nor N-back, alone or combined, affected hemodynamic parameters. 2-Back power and OLBNP individually were compared with 2-back power during OLBNP. 2-Back alone produced a narrow band increase in oscillatory arterial pressure (OAP) and oscillatory cerebral blood flow power centered at 0.0083 Hz. Functional hyperemia in response to 2-back was reduced to near baseline and 2-back memory performance was decreased by 0.03-, 0.05-, and 0.10-Hz OLBNP. OLBNP alone produced increased oscillatory power at frequencies of oscillation not suppressed by added 2-back. However, 2-back preceding OLBNP suppressed OLBNP power. OLBNP-driven oscillatory CBFv blunts NVC and memory performance, while memory task reciprocally interfered with forced CBFv oscillations. This shows that induced cerebral blood flow oscillations suppress functional hyperemia and functional hyperemia suppresses cerebral blood flow oscillations. NEW & NOTEWORTHY We show that induced cerebral blood flow oscillations suppress functional hyperemia produced by a working memory task as well as memory task performance. We conclude that oscillatory cerebral blood flow produces causal reductions of memory task neurovascular coupling and memory task performance. Reductions of functional hyperemia are constrained by autoregulation. Copyright © 2017 the American Physiological Society.

Essential hypertension--is erroneous receptor output to blame?

PubMed

Ufnal, Marcin

2012-04-01

Hypertension is a chronic medical condition in which systemic arterial blood pressure is elevated. About 80-90% of diagnosed hypertension is considered essential (idiopathic), which means there is no obvious cause of the increase in blood pressure. My hypothesis states that part of idiopathic hypertension results from erroneous information that the brain receives from receptors involved in the regulation of arterial blood pressure, i.e. if, despite high systemic blood pressure, the brain receives false "low-arterial pressure input" from cardiovascular receptors. As a result the brain centres which control blood pressure reset and produce an inappropriate output to the effectors (heart, blood vessels, kidneys and glands). The information errors may result from: (i) structural and/or functional impairment of cardiovascular receptors, (ii) changes in cardiovascular receptors activity, which are caused by other factors than changes in blood pressure, and (iii) impaired transmission in afferent fibres. I assume that in contrast to the lack of input from damaged or denervated cardiovascular receptors, an erroneous input will impair the control of arterial blood pressure. This will apply especially to false input which imitates "low-arterial pressure input". Higher priority of "low-arterial pressure input" over "high-arterial pressure input" or none input may be explained by the evolutionary adaptation, i.e. low blood pressure, mostly due to haemorrhage, used to be a more common condition than high blood pressure and constitute a major threat to humans. Copyright © 2012 Elsevier Ltd. All rights reserved.

Does dysfunction of the autonomic nervous system affect success of renal denervation in reducing blood pressure?

PubMed

Fricke, Lisa; Petroff, David; Desch, Steffen; Lurz, Philipp; Reinhardt, Sebastian; Sonnabend, Melanie; Classen, Joseph; Baum, Petra

2017-01-01

Renal denervation is an interventional approach aiming to reduce high blood pressure. Its efficacy is subject of controversial debate. We analyzed autonomic function in patients undergoing renal denervation to identify responders. A total of 21 patients with treatment-resistant hypertension scheduled for renal denervation were included. Heart rate variability, pupillary function and sympathetic skin response were examined prior to intervention. Before and 1 or 3 months after intervention, 24-h ambulatory blood pressure readings were taken. Patients were stratified according to sympathetic nervous system function. Sympathetic activity was reduced in 12 participants (group 1) and normal or enhanced in nine patients (group 2). The mean of daytime systolic blood pressure decreased in groups 1 and 2 from 168 to 157 mmHg (95% confidence interval for difference, 1-21 mmHg, p = 0.035) and from 166 to 145 mmHg (8-34 mmHg, p = 0.005), respectively. In a linear model, blood pressure reduction was 11.3 mmHg (0.3-22 mmHg) greater in group 2 than in group 1 (p = 0.045). Patients with preexisting reduced activity of the sympathetic nervous system benefited less from renal denervation.

Autonomic neural control of dynamic cerebral autoregulation in humans

NASA Technical Reports Server (NTRS)

Zhang, Rong; Zuckerman, Julie H.; Iwasaki, Kenichi; Wilson, Thad E.; Crandall, Craig G.; Levine, Benjamin D.

2002-01-01

BACKGROUND: The purpose of the present study was to determine the role of autonomic neural control of dynamic cerebral autoregulation in humans. METHODS AND RESULTS: We measured arterial pressure and cerebral blood flow (CBF) velocity in 12 healthy subjects (aged 29+/-6 years) before and after ganglion blockade with trimethaphan. CBF velocity was measured in the middle cerebral artery using transcranial Doppler. The magnitude of spontaneous changes in mean blood pressure and CBF velocity were quantified by spectral analysis. The transfer function gain, phase, and coherence between these variables were estimated to quantify dynamic cerebral autoregulation. After ganglion blockade, systolic and pulse pressure decreased significantly by 13% and 26%, respectively. CBF velocity decreased by 6% (P<0.05). In the very low frequency range (0.02 to 0.07 Hz), mean blood pressure variability decreased significantly (by 82%), while CBF velocity variability persisted. Thus, transfer function gain increased by 81%. In addition, the phase lead of CBF velocity to arterial pressure diminished. These changes in transfer function gain and phase persisted despite restoration of arterial pressure by infusion of phenylephrine and normalization of mean blood pressure variability by oscillatory lower body negative pressure. CONCLUSIONS: These data suggest that dynamic cerebral autoregulation is altered by ganglion blockade. We speculate that autonomic neural control of the cerebral circulation is tonically active and likely plays a significant role in the regulation of beat-to-beat CBF in humans.

A U-shaped Association Between Blood Pressure and Cognitive Impairment in Chinese Elderly.

PubMed

Lv, Yue-Bin; Zhu, Peng-Fei; Yin, Zhao-Xue; Kraus, Virginia Byers; Threapleton, Diane; Chei, Choy-Lye; Brasher, Melanie Sereny; Zhang, Juan; Qian, Han-Zhu; Mao, Chen; Matchar, David Bruce; Luo, Jie-Si; Zeng, Yi; Shi, Xiao-Ming

2017-02-01

Higher or lower blood pressure may relate to cognitive impairment, whereas the relationship between blood pressure and cognitive impairment among the elderly is not well-studied. The study objective was to determine whether blood pressure is associated with cognitive impairment in the elderly, and, if so, to accurately describe the association. Cross-sectional data from the sixth wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) conducted in 2011. Community-based setting in longevity areas in China. A total of 7144 Chinese elderly aged 65 years and older were included in the sample. Systolic blood pressures (SBP) and diastolic blood pressures (DBP) were measured, pulse pressure (PP) was calculated as (SBP) - (DBP) and mean arterial pressures (MAP) was calculated as 1/3(SBP) + 2/3(DBP). Cognitive function was assessed via a validated Mini-Mental State Examination (MMSE). Based on the results of generalized additive models (GAMs), U-shaped associations were identified between cognitive impairment and SBP, DBP, PP, and MAP. The cutpoints at which risk for cognitive impairment (MMSE <24) was minimized were determined by quadratic models as 141 mm Hg, 85 mm Hg, 62 mm Hg, and 103 mm Hg, respectively. In the logistic models, U-shaped associations remained for SBP, DBP, and MAP but not PP. Below the identified cutpoints, each 1-mm Hg decrease in blood pressure corresponded to 0.7%, 1.1%, and 1.1% greater risk in the risk of cognitive impairment, respectively. Above the cutpoints, each 1-mm Hg increase in blood pressure corresponded to 1.2%, 1.8%, and 2.1% greater risk of cognitive impairment for SBP, DBP, and MAP, respectively. A U-shaped association between blood pressure and cognitive function in an elderly Chinese population was found. Recognition of these instances is important in identifying the high-risk population for cognitive impairment and to individualize blood pressure management for cognitive impairment prevention. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. All rights reserved.

Comparison of Blood Lipids, Blood Pressures and Left Ventricular Cavity Dimension between Soccer Players and Non-Athletes

ERIC Educational Resources Information Center

Gokhan, Ismail; Kurkcu, Recep; Cekin, Resul

2013-01-01

In this study, it was aimed to compare the investigate the effects of regular exercise on blood lipids, blood pressure and left ventricular cavity dimensions function between soccer players and non-athletes in football players. This study consisted included a total of 30 subjects, including an experimental group including 18 soccer players…

High beat-to-beat blood pressure variability in atrial fibrillation compared to sinus rhythm.

PubMed

Olbers, Joakim; Gille, Adam; Ljungman, Petter; Rosenqvist, Mårten; Östergren, Jan; Witt, Nils

2018-02-07

Atrial fibrillation (AF) is associated with an increased risk for cardiovascular morbidity and mortality, not entirely explained by thromboembolism. The underlying mechanisms for this association are largely unknown. Similarly, high blood pressure (BP) increases the risk for cardiovascular events. Despite this the interplay between AF and BP is insufficiently studied. The purpose of this study was to examine and quantify the beat-to-beat blood pressure variability in patients with AF in comparison to a control group of patients with sinus rhythm. We studied 33 patients - 21 in atrial fibrillation and 12 in sinus rhythm - undergoing routine coronary angiography. Invasive blood pressure was recorded at three locations: radial artery, brachial artery and ascending aorta. Blood pressure variability, defined as average beat-to-beat blood pressure difference, was calculated for systolic and diastolic blood pressure at each site. We observed a significant difference (p < .001) in systolic and diastolic blood pressure variability between the atrial fibrillation and sinus rhythm groups at all locations. Systolic blood pressure variability roughly doubled in the atrial fibrillation group compared to the sinus rhythm group (4.9 and 2.4 mmHg respectively). Diastolic beat-to-beat blood pressure variability was approximately 6 times as high in the atrial fibrillation group compared to the sinus rhythm group (7.5 and 1.2 mmHg respectively). No significant difference in blood pressure variability was seen between measurement locations. Beat-to-beat blood pressure variability in patients with atrial fibrillation was substantially higher than in patients with sinus rhythm. Hemodynamic effects of this beat-to-beat variation in blood pressure may negatively affect vascular structure and function, which may contribute to the increased cardiovascular morbidity and mortality seen in patients with atrial fibrillation.

The effect of Camphor-Crataegus berry extract combination on blood pressure and mental functions in chronic hypotension--a randomized placebo controlled double blind design.

PubMed

Schandry, Rainer; Duschek, Stefan

2008-11-01

A number of studies have provided evidence for reduced cognitive performance due to chronically low blood pressure. The present studies explored whether these deficits can be reduced by pharmacological blood pressure elevation. Effects of the Camphor-Crataegus berry extract combination (Korodin(®)) were investigated in two studies with 40 and 48 hypotensive women based on a randomized, placebo controlled double blind design. The participants were presented with different tasks assessing performance in attention and cognition. Blood pressure was measured repeatedly during the experiment. The administration of the drug led to positive and differential effects on blood pressure and cognitive performance as compared to placebo. These effects were already visible within the time range of 2-5 min. A positive correlation between blood pressure increase and performance enhancement could be demonstrated for two of the four tasks. The results show that the application of Korodin(®) results in beneficial effects on resting blood pressure and cognitive performance. The positive association between the increase in blood pressure and cognitive enhancement suggests that blood pressure plays a causal role in the cognitive deficits in hypotension and underlines that they can be reduced through antihypotensive treatment.

Serotonin and Blood Pressure Regulation

PubMed Central

Morrison, Shaun F.; Davis, Robert Patrick; Barman, Susan M.

2012-01-01

5-Hydroxytryptamine (5-HT; serotonin) was discovered more than 60 years ago as a substance isolated from blood. The neural effects of 5-HT have been well investigated and understood, thanks in part to the pharmacological tools available to dissect the serotonergic system and the development of the frequently prescribed selective serotonin-reuptake inhibitors. By contrast, our understanding of the role of 5-HT in the control and modification of blood pressure pales in comparison. Here we focus on the role of 5-HT in systemic blood pressure control. This review provides an in-depth study of the function and pharmacology of 5-HT in those tissues that can modify blood pressure (blood, vasculature, heart, adrenal gland, kidney, brain), with a focus on the autonomic nervous system that includes mechanisms of action and pharmacology of 5-HT within each system. We compare the change in blood pressure produced in different species by short- and long-term administration of 5-HT or selective serotonin receptor agonists. To further our understanding of the mechanisms through which 5-HT modifies blood pressure, we also describe the blood pressure effects of commonly used drugs that modify the actions of 5-HT. The pharmacology and physiological actions of 5-HT in modifying blood pressure are important, given its involvement in circulatory shock, orthostatic hypotension, serotonin syndrome and hypertension. PMID:22407614

Protein disulfide isomerase regulates renal AT1 receptor function and blood pressure in rats.

PubMed

Wang, Xitao; Asghar, Mohammad

2017-08-01

The role and mechanism of renal protein disulfide isomerase (PDI) in blood pressure regulation has not been tested before. Here, we test this possibility in Sprague-Dawley rats. Rats were treated with PDI inhibitor bacitracin (100 mg·kg -1 ip·day -1 for 14 days), and then blood pressure and renal angiotensin II type 1 (AT 1 ) receptor function were determined in anesthetized rats. Renal AT 1 receptor function was determined as the ability of candesartan (an AT 1 receptor blocker) to increase diuresis and natriuresis. A second set of vehicle- and bacitracin-treated rats was used to determine biochemical parameters. Systolic blood pressure as well as diastolic blood pressure increased in bacitracin-treated compared with vehicle-treated rats. Compared with vehicle, bacitracin-treated rats showed increased diuresis and natriuresis in response to candesartan (10-µg iv bolus dose) suggesting higher AT 1 receptor function in these rats. These were associated with higher renin activities in the plasma and renal tissues. Furthermore, urinary 8-isoprostane and kidney injury molecule-1 levels were higher and urinary antioxidant capacity was lower in bacitracin-treated rats. Renal protein carbonyl and nitrotyrosine levels also were higher in bacitracin- compared with vehicle-treated rats, suggesting oxidative stress burden in bacitracin-treated rats. Moreover, PDI activity decreased and its protein levels increased in renal tissues of bacitracin-treated rats. Also, nuclear levels of Nrf2 transcription factor, which regulates redox homeostasis, were decreased in bacitracin-treated rats. Furthermore, tissue levels of Keap1, an Nrf2 inhibitory molecule, and tyrosine 216-phosphorylated GSK3β protein, an Nrf2 nuclear export protein, were increased in bacitracin-treated rats. These results suggest that renal PDI by regulating Keap1-Nrf2 pathway acts as an antioxidant, maintaining redox balance, renal AT 1 receptor function, and blood pressure in rats. Copyright © 2017 the American Physiological Society.

The relationships between air exposure, negative pressure, and hemolysis.

PubMed

Pohlmann, Joshua R; Toomasian, John M; Hampton, Claire E; Cook, Keith E; Annich, Gail M; Bartlett, Robert H

2009-01-01

The purpose of this study was to describe the hemolytic effects of both negative pressure and an air-blood interface independently and in combination in an in vitro static blood model. Samples of fresh ovine or human blood (5 ml) were subjected to a bubbling air interface (0-100 ml/min) or negative pressure (0-600 mm Hg) separately, or in combination, for controlled periods of time and analyzed for hemolysis. Neither negative pressure nor an air interface alone increased hemolysis. However, when air and negative pressure were combined, hemolysis increased as a function of negative pressure, the air interface, and time. Moreover, when blood samples were exposed to air before initiating the test, hemolysis was four to five times greater than samples not preexposed to air. When these experiments were repeated using freshly drawn human blood, the same phenomena were observed, but the hemolysis was significantly higher than that observed in sheep blood. In this model, hemolysis is caused by combined air and negative pressure and is unrelated to either factor alone.

Visit-to-visit and 24-h blood pressure variability: association with endothelial and smooth muscle function in African Americans.

PubMed

Diaz, K M; Veerabhadrappa, P; Kashem, M A; Thakkar, S R; Feairheller, D L; Sturgeon, K M; Ling, C; Williamson, S T; Kretzschmar, J; Lee, H; Grimm, H; Babbitt, D M; Vin, C; Fan, X; Crabbe, D L; Brown, M D

2013-11-01

The purpose of this study was to investigate the association of visit-to-visit and 24-h blood pressure (BP) variability with markers of endothelial injury and vascular function. We recruited 72 African Americans who were non-diabetic, non-smoking and free of cardiovascular (CV) and renal disease. Office BP was measured at three visits and 24-h ambulatory BP monitoring was conducted to measure visit-to-visit and 24-h BP variability, respectively. The 5-min time-course of brachial artery flow-mediated dilation and nitroglycerin-mediated dilation were assessed as measures of endothelial and smooth muscle function. Fasted blood samples were analyzed for circulating endothelial microparticles (EMPs). Significantly lower CD31+CD42- EMPs were found in participants with high visit-to-visit systolic blood pressure (SBP) variability or high 24-h diastolic blood pressure (DBP) variability. Participants with high visit-to-visit DBP variability had significantly lower flow-mediated dilation and higher nitroglycerin-mediated dilation at multiple time-points. When analyzed as continuous variables, 24-h mean arterial pressure variability was inversely associated with CD62+ EMPs; visit-to-visit DBP variability was inversely associated with flow-mediated dilation normalized by smooth muscle function and was positively associated with nitroglycerin-mediated dilation; and 24-h DBP variability was positively associated with nitroglycerin-mediated dilation. All associations were independent of age, gender, body mass index and mean BP. In conclusion, in this cohort of African Americans visit-to-visit and 24-h BP variability were associated with measures of endothelial injury, endothelial function and smooth muscle function. These results suggest that BP variability may influence the pathogenesis of CV disease, in part, through influences on vascular health.

Baroreflex buffering and susceptibility to vasoactive drugs

NASA Technical Reports Server (NTRS)

Jordan, Jens; Tank, Jens; Shannon, John R.; Diedrich, Andre; Lipp, Axel; Schroder, Christoph; Arnold, Guy; Sharma, Arya M.; Biaggioni, Italo; Robertson, David;

Blood pressure, brain structure, and cognition: opposite associations in men and women.

PubMed

Cherbuin, Nicolas; Mortby, Moyra E; Janke, Andrew L; Sachdev, Perminder S; Abhayaratna, Walter P; Anstey, Kaarin J

2015-02-01

Research on associations between blood pressure, brain structure, and cognitive function has produced somewhat inconsistent results. In part, this may be due to differences in age ranges studied and because of sex differences in physiology and/or exposure to risk factors, which may lead to different time course or patterns in cardiovascular disease progression. The aim of this study was to investigate the impact of sex on associations between blood pressure, regional cerebral volumes, and cognitive function in older individuals. In this cohort study, brachial blood pressure was measured twice at rest in 266 community-based individuals free of dementia aged 68-73 years who had also undergone a brain scan and a neuropsychological assessment. Associations between mean blood pressure (MAP), regional brain volumes, and cognition were investigated with voxel-wise regression analyses. Positive associations between MAP and regional volumes were detected in men, whereas negative associations were found in women. Similarly, there were sex differences in the brain-volume cognition relationship, with a positive relationship between regional brain volumes associated with MAP in men and a negative relationship in women. In this cohort of older individuals, higher MAP was associated with larger regional volume and better cognition in men, whereas opposite findings were demonstrated in women. These effects may be due to different lifetime risk exposure or because of physiological differences between men and women. Future studies investigating the relationship between blood pressure and brain structure or cognitive function should evaluate the potential for differential sex effects. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Blood pressure interacts with APOE ε4 to predict memory performance in a midlife sample.

PubMed

Oberlin, Lauren E; Manuck, Stephen B; Gianaros, Peter J; Ferrell, Robert E; Muldoon, Matthew F; Jennings, J Richard; Flory, Janine D; Erickson, Kirk I

2015-09-01

Elevated blood pressure and the Apolipoprotein ε4 allele (APOE ε4) are independent risk factors for Alzheimer's disease. We sought to determine whether the combined presence of the APOE ε4 allele and elevated blood pressure is associated with lower cognitive performance in cognitively healthy middle-aged adults. A total of 975 participants aged 30-54 (mean age = 44.47) were genotyped for APOE. Cardiometabolic risk factors including blood pressure, lipids, and glucose were assessed and cognitive function was measured using the Trail Making Test and the Visual Reproduction and Logical Memory subtests from the Wechsler Memory Scale. Multivariable regression analysis showed that the association between APOE ε4 and episodic memory performance varied as a function of systolic blood pressure (SBP), such that elevated SBP was predictive of poorer episodic memory performance only in APOE ε4 carriers (β = -.092; t = -2.614; p = .009). Notably, this association was apparent at prehypertensive levels (≥130 mmHg), even after adjusting for physical activity, depression, smoking, and other cardiometabolic risk factors. The joint presence of APOE ε4 and elevated SBP, even at prehypertensive levels, is associated with lower cognitive performance in healthy, middle-aged adults. Results of this study suggest that the combination of APOE ε4 and elevated SBP may synergistically compromise memory function well before the appearance of clinically significant impairments. Interventions targeting blood pressure control in APOE ε4 carriers during midlife should be studied as a possible means to reduce the risk of cognitive decline in genetically susceptible samples. (c) 2015 APA, all rights reserved).

Dynamic Cerebral Autoregulation is Preserved During Acute Head-down Tilt

DTIC Science & Technology

2003-06-27

relationship of mean arterial pressure to mean cerebral blood flow velocity transfer function gain at the high and low frequencies, respectively; TCD-PHASE...HF and TCD-PHASE-LF, phase angle between mean arterial pressure and mean cerebral blood flow veloc- ity at high and low frequencies, respectively...arterial pressure and mean ce- rebral blood flow oscillations decrease from low- to high -frequency ranges. Average phase angles were 68° at low frequencies

Tonic blood pressure modulates the relationship between baroreceptor cardiac reflex sensitivity and cognitive performance.

PubMed

Del Paso, Gustavo A Reyes; González, M Isabel; Hernández, José Antonio; Duschek, Stefan; Gutiérrez, Nicolás

2009-09-01

This study explored the effects of tonic blood pressure on the association between baroreceptor cardiac reflex sensitivity and cognitive performance. Sixty female participants completed a mental arithmetic task. Baroreceptor reflex sensitivity was assessed using sequence analysis. An interaction was found, indicating that the relationship between baroreceptor reflex sensitivity and cognitive performance is modulated by blood pressure levels. Reflex sensitivity was inversely associated to performance indices in the subgroup of participants with systolic blood pressure above the mean, whereas the association was positive in participants with systolic values below the mean. These results are in accordance with the findings in the field of pain perception and suggest that tonic blood pressure modulates the inhibitory effects of baroreceptor stimulation on high central nervous functions.

Exploring Heart and Lung Function in Space: ARMS Experiments

NASA Technical Reports Server (NTRS)

Kuipers, Andre; Cork, Michael; LeGouic, Marine

2002-01-01

The Advanced Respiratory Monitoring System (ARMS) is a suite of monitoring instruments and supplies used to study the heart, lungs, and metabolism. Many experiments sponsored by the European Space Agency (ESA) will be conducted using ARMS during STS-107. The near-weightless environment of space causes the body to undergo many physiological adaptations, and the regulation of blood pressure is no exception. Astronauts also experience a decrease in blood volume as an adaptation to microgravity. Reduced blood volume may not provide enough blood pressure to the head during entry or landing. As a result, astronauts often experience light-headedness, and sometimes even fainting, when they stand shortly after returning to Earth. To help regulate blood pressure and heart rate, baroreceptors, sensors located in artery walls in the neck and near the heart, control blood pressure by sending information to the brain and ensuring blood flow to organs. These mechanisms work properly in Earth's gravity but must adapt in the microgravity environment of space. However, upon return to Earth during entry and landing, the cardiovascular system must readjust itself to gravity, which can cause fluctuation in the control of blood pressure and heart rate. Although the system recovers in hours or days, these occurrences are not easily predicted or understood - a puzzle investigators will study with the ARMS equipment. In space, researchers can focus on aspects of the cardiovascular system normally masked by gravity. The STS-107 experiments using ARMS will provide data on how the heart and lungs function in space, as well as how the nervous system controls them. Exercise will also be combined with breath holding and straining (the Valsalva maneuver) to test how heart rate and blood pressure react to different stresses. This understanding will improve astronauts' cardiopulmonary function after return to Earth, and may well help Earthbound patients who experience similar effects after long-term bed rest.

Effects of wheelchair cushions and pressure relief maneuvers on ischial interface pressure and blood flow in people with spinal cord injury.

PubMed

Sonenblum, Sharon E; Vonk, Teddie E; Janssen, Thomas W; Sprigle, Stephen H

2014-07-01

To investigate the effectiveness and interactions of 2 methods of pressure ulcer prevention, wheelchair cushions and pressure relief maneuvers, on interface pressure (IP) and blood flow of the buttocks. Within-subject repeated measures. Rehabilitation center. Wheelchair users with a spinal cord injury or disorder (N=17). Participants performed 3 forward leans and 2 sideward leans with different degrees of lean while seated on each of 3 different wheelchair cushions. IP measured with a custom sensor and blood flow measured with laser Doppler flowmetry were collected at the ischial tuberosity. Pressure relief maneuvers had a significant main effect on the ischial IP (P<.001); all maneuvers except for the small frontward lean resulted in a significant reduction in IP compared with upright sitting. Blood flow significantly varied across postures (P<.001) with flow during upright sitting and small forward leans being significantly lower than during the full and intermediate leans in both the forward and sideward directions. The results of the study highlight the importance of positioning wheelchair users in a manner that facilitates in-seat movement. Regardless of the cushion being used, the pressure relief maneuvers resulted in very large reductions in IPs and significant increases in buttock blood flow. Only the small frontward lean was shown to be ineffective in reducing pressure or increasing blood flow. Because these pressure relief maneuvers involved postural changes that can occur during functional activities, these pressure relief maneuvers can become a part of volitional pressure relief and functional weight shifts. Therefore, clinical instruction should cover both as a means to impart sitting behaviors that may lead to better tissue health. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Gastric emptying, postprandial blood pressure, glycaemia and splanchnic flow in Parkinson's disease.

PubMed

Trahair, Laurence G; Kimber, Thomas E; Flabouris, Katerina; Horowitz, Michael; Jones, Karen L

2016-05-28

To determine gastric emptying, blood pressure, mesenteric artery blood flow, and blood glucose responses to oral glucose in Parkinson's disease. Twenty-one subjects (13 M, 8 F; age 64.2 ± 1.6 years) with mild to moderate Parkinson's disease (Hoehn and Yahr score 1.4 ± 0.1, duration of known disease 6.3 ± 0.9 years) consumed a 75 g glucose drink, labelled with 20 MBq (99m)Tc-calcium phytate. Gastric emptying was quantified with scintigraphy, blood pressure and heart rate with an automated device, superior mesenteric artery blood flow by Doppler ultrasonography and blood glucose by glucometer for 180 min. Autonomic nerve function was evaluated with cardiovascular reflex tests and upper gastrointestinal symptoms by questionnaire. The mean gastric half-emptying time was 106 ± 9.1 min, gastric emptying was abnormally delayed in 3 subjects (14%). Systolic and diastolic blood pressure fell (P < 0.001) and mesenteric blood flow and blood glucose (P < 0.001 for both) increased, following the drink. Three subjects (14%) had definite autonomic neuropathy and 8 (38%) had postprandial hypotension. There were no significant relationships between changes in blood pressure, heart rate or mesenteric artery blood flow with gastric emptying. Gastric emptying was related to the score for autonomic nerve function (R = 0.55, P < 0.01). There was an inverse relationship between the blood glucose at t = 30 min (R = -0.52, P < 0.05), while the blood glucose at t = 180 min was related directly (R = 0.49, P < 0.05), with gastric emptying. In mild to moderate Parkinson's disease, gastric emptying is related to autonomic dysfunction and a determinant of the glycaemic response to oral glucose.

Effects of blood pressure and sex on the change of wave reflection: evidence from Gaussian fitting method for radial artery pressure waveform.

PubMed

Liu, Chengyu; Zhao, Lina; Liu, Changchun

2014-01-01

An early return of the reflected component in the arterial pulse has been recognized as an important indicator of cardiovascular risk. This study aimed to determine the effects of blood pressure and sex factor on the change of wave reflection using Gaussian fitting method. One hundred and ninety subjects were enrolled. They were classified into four blood pressure categories based on the systolic blood pressures (i.e., ≤ 110, 111-120, 121-130 and ≥ 131 mmHg). Each blood pressure category was also stratified for sex factor. Electrocardiogram (ECG) and radial artery pressure waveforms (RAPW) signals were recorded for each subject. Ten consecutive pulse episodes from the RAPW signal were extracted and normalized. Each normalized pulse episode was fitted by three Gaussian functions. Both the peak position and peak height of the first and second Gaussian functions, as well as the peak position interval and peak height ratio, were used as the evaluation indices of wave reflection. Two-way ANOVA results showed that with the increased blood pressure, the peak position of the second Gaussian significantly shorten (P < 0.01), the peak height of the first Gaussian significantly decreased (P < 0.01) and the peak height of the second Gaussian significantly increased (P < 0.01), inducing the significantly decreased peak position interval and significantly increased peak height ratio (both P < 0.01). Sex factor had no significant effect on all evaluation indices (all P > 0.05). Moreover, the interaction between sex and blood pressure factors also had no significant effect on all evaluation indices (all P > 0.05). These results showed that blood pressure has significant effect on the change of wave reflection when using the recently developed Gaussian fitting method, whereas sex has no significant effect. The results also suggested that the Gaussian fitting method could be used as a new approach for assessing the arterial wave reflection.

High blood pressure in acute ischemic stroke and clinical outcome

PubMed Central

Manabe, Yasuhiro; Kono, Syoichiro; Tanaka, Tomotaka; Narai, Hisashi; Omori, Nobuhiko

2009-01-01

This study aimed to evaluate the prognostic value of acute phase blood pressure in patients with acute ischemic stroke by determining whether or not it contributes to clinical outcome. We studied 515 consecutive patients admitted within the first 48 hours after the onset of ischemic strokes, employing systolic and diastolic blood pressure measurements recorded within 36 hours after admission. High blood pressure was defined when the mean of at least 2 blood pressure measurements was ≥200 mmHg systolic and/or ≥110 mmHg diastolic at 6 to 24 hours after admission or ≥180 mmHg systolic and/or ≥105 mmHg diastolic at 24 to 36 hours after admission. The high blood pressure group was found to include 16% of the patients. Age, sex, diabetes mellitus, hypercholesterolemia, atrial fibrillation, ischemic heart disease, stroke history, carotid artery stenosis, leukoaraiosis, NIH Stroke Scale (NIHSS) on admission and mortality were not significantly correlated with either the high blood pressure or non-high blood pressure group. High blood pressure on admission was significantly associated with a past history of hypertension, kidney disease, the modified Rankin Scale (mRS) on discharge and the length of stay. On logistic regression analysis, with no previous history of hypertension, diabetes mellitus, atrial fibrillation, and kidney disease were independent risk factors associated with the presence of high blood pressure [odds ratio (OR), 1.85 (95% confidence interval (CI): 1.06–3.22), 1.89 (95% CI: 1.11–3.22), and 3.31 (95% CI: 1.36–8.04), respectively]. Multi-organ injury may be presented in acute stroke patients with high blood pressure. Patients with high blood pressure had a poor functional outcome after acute ischemic stroke. PMID:21577346

APOL1 genetic variants are not associated with longitudinal blood pressure in young black adults.

PubMed

Chen, Teresa K; Estrella, Michelle M; Vittinghoff, Eric; Lin, Feng; Gutierrez, Orlando M; Kramer, Holly; Lewis, Cora E; Kopp, Jeffrey B; Allen, Norrina B; Winkler, Cheryl A; Bibbins-Domingo, Kirsten B; Peralta, Carmen A

2017-10-01

Whether APOL1 polymorphisms contribute to the excess risk of hypertension among blacks is unknown. To assess this we evaluated whether self-reported race and, in blacks, APOL1 risk variants (high-risk [2 risk alleles] versus low-risk [0-1 risk allele]) were associated with longitudinal blood pressure. Blood pressure trajectories were determined using linear mixed-effects (slope) and latent class models (5 distinct groups) during 25 years of follow-up in the Coronary Artery Risk Development in Young Adults Study. Associations of race and APOL1 genotypes with blood pressure change, separately, using linear mixed-effects and multinomial logistic regression models, adjusting for demographic, socioeconomic, and traditional hypertension risk factors, anti-hypertensive medication use, and kidney function were evaluated. Among 1700 whites and 1330 blacks (13% APOL1 high-risk, mean age 25 years; 46% male) mean mid-, ([systolic + diastolic blood pressure]/2), systolic, and diastolic blood pressures were 89, 110, and 69 mm Hg, respectively. One percent of participants used anti-hypertensive medications at baseline. Compared to whites, blacks, regardless of APOL1 genotype, had significantly greater increases in mid-blood pressure and were more likely to experience significantly increasing mid-blood pressure trajectories with adjusted relative risk ratios of 5.21 and 7.27 for moderate-increasing and elevated-increasing versus low-stable blood pressure, respectively. Among blacks, longitudinal mid-blood pressure changes and mid-blood pressure trajectory classification were similar by APOL1 risk status. Modeling systolic and diastolic blood pressure as outcomes yielded similar findings. From young adulthood to mid-life, blacks have greater blood pressure increases versus whites that are not fully explained by traditional risk factors. Thus APOL1 variants are not associated with longitudinal blood pressure in blacks. Copyright © 2017 International Society of Nephrology. All rights reserved.

Ankle-brachial index and inter-artery blood pressure differences as predictors of cognitive function in overweight and obese older adults with diabetes: results from the Action for Health in Diabetes movement and memory study.

PubMed

Espeland, Mark A; Beavers, Kristen M; Gibbs, Bethany Barone; Johnson, Karen C; Hughes, Timothy M; Baker, Laura D; Jakicic, John; Korytkowski, Mary; Miller, Marsha; Bray, George A

2015-10-01

Ankle-brachial index (ABI) and interartery systolic blood pressure differences, as markers of vascular disease, are plausible risk factors for deficits in cognitive function among overweight and obese adults with type 2 diabetes. The ABI and maximum interartery differences (MIAD) in systolic blood pressures were assessed annually for five years among 479 participants assigned to the control condition in a randomized clinical trial of a behavioral weight loss intervention. A battery of standardized cognitive function tests was administered 4 to 5 years later. Analyses of covariance were used to assess relationships that ABI, MIAD, and progression of ABI and MIAD had with cognitive function. There was a curvilinear relationship between ABI and a composite index of cognitive function (p = 0.03), with lower ABI being associated with poorer function. In graded fashions, both greater MIAD and increases in MIAD over time also had modest relationships with poorer verbal memory (both p ≤ 0.05), processing speed (both p ≤ 0.05), and composite cognitive function (both p < 0.04). These relationships were independent of each other and remained evident after extensive covariate adjustment. In overweight and obese adults with type 2 diabetes, lower ABI and larger interartery systolic blood pressure differences have modest, independent, graded relationships with poorer cognitive function 4-5 years later. Copyright © 2014 John Wiley & Sons, Ltd.

Psychophysiology of arterial baroreceptors and the etiology of hypertension.

PubMed

Rau, H; Elbert, T

2001-01-01

Arterial baroreceptors are sensitive to blood pressure dependent blood vessel dilation. They play a key role in the short term regulation of blood pressure. Their impact on psychological and psychophysiological aspects is of increasing interest. The review focuses on experimental techniques for the controlled baroreceptor manipulation. Results from the application of these techniques show that baroreceptor activation influences the cardiovascular system as well as central nervous functioning: Behavioral and electrophysiological measures of arousal, low level reflexes and pain responses are modulated through baroreceptor manipulation. The observation of an overall dampening ('barbiturate like') effect of baroreceptor activity led Dworkin et al. formulate the theory of learned hypertension: Subjects might experience blood pressure dependent baroreceptor activation as stress and pain relieving. High blood pressure periods become negatively reinforced. Phasic high blood pressure might develop as a coping strategy. Data from a longitudinal human study supporting this theory are reported.

Biomarkers of Renal Tumor Burden and Progression in TSC

DTIC Science & Technology

2012-09-01

code) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 Biomarkers of Renal Tumor Burden and Progression in TSC Dr. Elahna Paul 1...appearance and growth rates) and renal function parameters (e.g. blood pressure, serum chemistries, urinalysis and urine chemistries). (2) Measure...and renal function parameters (e.g. blood pressure, serum chemistries, urinalysis and urine chemistries). (2) Measure soluble growth factors

Pediatric ptosis as a sign of treatable autonomic dysfunction.

PubMed

Phillips, Lara; Robertson, David; Melson, Mark R; Garland, Emily M; Joos, Karen M

2013-08-01

To report the ophthalmic findings in young patients with dopamine β-hydroxylase deficiency and to assess them in the context of other reports in an attempt to discern if ophthalmic criteria may assist in early detection of this debilitating, yet treatable, disorder. Prospective, observational case series. An ophthalmic examination, including measuring intraocular and systemic blood pressures while supine, sitting, and standing, and eyelid function and pupillary function testing, was completed on 3 young patients with recently documented dopamine β-hydroxylase deficiency at a single institution. Mean arterial blood pressures were 90.1 ± 18.5 mm Hg supine, 79.1 ± 25.7 mm Hg sitting, and 45.8 ± 11.6 mm Hg standing (P = .021). Mean intraocular pressures in these patients were 15.8 ± 1.0 mm Hg supine, 15.0 ± 3.6 mm Hg sitting, and 7.7 ± 2.3 mm Hg standing (P = .03). Mean palpebral fissure, levator function, and margin reflex distance were 8.2 ± 1.0 mm, 16.0 ± 0 mm, and 2.8 ± 0.6 mm, respectively. Measurable miosis was present in only 1 patient, and pupillary supersensitivity to 2.5% phenylephrine was not observed. The ophthalmologic findings of the patients in this case series documented mild ptosis and striking orthostatic reductions in intraocular pressure and mean arterial blood pressure, as might be expected with a lack of intrinsic sympathetic function. Orthostatic intraocular pressure and mean arterial blood pressure may be a helpful early screening tool for autonomic dysfunction in children undergoing a ptosis evaluation. Copyright © 2013 Elsevier Inc. All rights reserved.

Transcranial Doppler monitoring in Parkinson's disease: cerebrovascular compensation of orthostatic hypotension.

PubMed

Haubrich, Christina; Pies, Katrin; Dafotakis, Manuel; Block, Frank; Kloetzsch, Christof; Diehl, Rolf R

2010-10-01

Despite of precipitous blood pressure falls in Parkinson's Disease (PD) patients, they may not experience syncope or postural complaints. Can cerebral blood flow regulation explain why orthostatic hypotension (OH) has often no accompanying symptoms? In patients with PD and OH (18 asymptomatic; 8 symptomatic), arterial blood pressure (ABP) as well as Doppler-detected cerebral blood flow velocity (CBFV) in middle and posterior cerebral arteries (MCA and PCA) were monitored during head-up tilt and compared with 25 controls and eight non-PD-OH patients. Analysis included the transfer function between slow spontaneous pressure and flow-oscillations. ABP and CBFV were maintained at significantly higher levels in asymptomatic than symptomatic PD-OH (ABP: 85.7 ± 10.5 vs. 66.9 ± 12.5%; MCA-FV: 83.3 ± 9.3 vs. 66.1 ± 6.8%; PCA-FV: 84.4 ± 12.2 vs. 65.9 ± 9.3% of supine). When orthostatic complaints occurred, CBFV depended directly on ABP changes (MCA r(2) = 0.64; PCA r(2) = 0.62; both p < 0.05). Despite of a tilt-induced blood pressure instability in PD-OH, the transfer function parameters did not differ from normal [phase: MCA: 46.6 ± 20.5°; PCA 39.2 ± 28.8°, gain: MCA 2.0 ± 0.7; PCA 2.9 ± 1.6)]. Results showed a normal autoregulatory response to downward blood pressure shifts in PD. Moreover, orthostatic blood pressure instability is compensated equally sufficient in anterior and posterior parts of cerebral circulation. Whether in PD patients, OH becomes symptomatic rather seems to depend on blood pressure falling below the autoregulated range. Copyright © 2010 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Extended duration orbiter medical project variability of blood pressure and heart rate (STS-50/USML-1)

NASA Technical Reports Server (NTRS)

Fritsch-Yelle, Janice M.; Charles, John B.; Boettcher, Sheila W.

1994-01-01

Decreases in arterial baroreflex function after space flight may be related to changes in blood pressure and heart rate patterns during flight. Ambulatory blood pressure and heart rate were measured for 24 hours, in fourteen astronauts on two occasions before flight, two to three occasions in flight, and 2 days after landing on Shuttle missions lasting 4 to 14 days. Blood pressure and heart rate were recorded every 20minutes during awake periods and every 30 minutes during sleep. In pre- and postflight studies, the 24-hour ambulatory measurements were followed by studies of carotid baroreceptor-cardiac reflex responses. Carotid baroreceptors were stimulated using a sequence of neck pressure and suction from +40 to -65 mmHg.

Dark chocolate for children's blood pressure: randomised trial.

PubMed

Chan, Eunice K; Quach, Jon; Mensah, Fiona K; Sung, Valerie; Cheung, Michael; Wake, Melissa

2012-07-01

Higher adult blood pressure, even without hypertension, predicts cardiovascular outcomes, and is predicted by childhood blood pressure. Regular dark chocolate intake lowers blood pressure in adults, but effects in children are unknown. To examine the feasibility of school-based provision of dark chocolate and its short-term efficacy in reducing mean group blood pressure. 194 children (aged 10-12 years) were randomised by class to intervention (7 g dark chocolate daily for 7 weeks, n=124) or control (n=70) groups; 98% and 93% provided baseline and follow-up measurements, respectively. Intervention and control students had similar systolic (mean difference 1.7 mm Hg, 95% CI -0.6 to 4.1) and diastolic (-1.2 mm Hg, 95% CI -3.6 to 1.3) blood pressure, anthropometry and well-being at outcome. Results show that providing dark chocolate is feasible and acceptable in the school setting. For a definitive trial, the authors recommend a larger sample, endovascular function measures, and consideration of higher antioxidant 'dose' by virtue of duration and/or content.

Psycho-Circulatory Responses Caused by Listening to Music, and Exposure to Fluctuating Noise or Steady Noise

NASA Astrophysics Data System (ADS)

SAKAMOTO, H.; HAYASHI, F.; SUGIURA, S.; TSUJIKAWA, M.

2002-02-01

This study investigated the effect of steady noise, fluctuating noise and music on circulatory function. Pulse-wave and blood pressure were continuously measured in 35 healthy young females who listened to three types of music or were exposed to steady noise or fluctuating noise, synchronized with each type of music with respect to intensity variations. The pulse-wave did not change during any exposure conditions. Regarding blood pressure, several modes were observed. The critical level for a blood pressure change was estimated to be 54 LAeqduring exposure to steady noise. The frequency of high-intensity peaks in the mode of sound fluctuation was associated with elevation in blood pressure. The blood pressure change was analyzed by distinguishing the intensity variation in sound fluctuation from other attributes of music. The effects of music on blood pressure were modified not only by the melody and timbre of the music but also by emotional responses during listing.

Central and peripheral blood pressures in relation to plasma advanced glycation end products in a Chinese population.

PubMed

Huang, Q-F; Sheng, C-S; Kang, Y-Y; Zhang, L; Wang, S; Li, F-K; Cheng, Y-B; Guo, Q-H; Li, Y; Wang, J-G

2016-07-01

We investigated the association of plasma AGE (advanced glycation end product) concentration with central and peripheral blood pressures and central-to-brachial blood pressure amplification in a Chinese population. The study subjects were from a newly established residential area in the suburb of Shanghai. Using the SphygmoCor system, we recorded radial arterial waveforms and derived aortic waveforms by a generalized transfer function and central systolic and pulse pressure by calibration for brachial blood pressure measured with an oscillometric device. The central-to-brachial pressure amplification was expressed as the central-to-brachial systolic blood pressure difference and pulse pressure difference and ratio. Plasma AGE concentration was measured by the enzyme-linked immunosorbent assay method and logarithmically transformed for statistical analysis. The 1051 participants (age, 55.1±13.1 years) included 663 women. After adjustment for sex, age and other confounding factors, plasma AGE concentration was associated with central but not peripheral blood pressures and with some of the pressure amplification indexes. Indeed, each 10-fold increase in plasma AGE concentration was associated with 2.94 mm Hg (P=0.04) higher central systolic blood pressure and 2.39% lower central-to-brachial pulse pressure ratio (P=0.03). In further subgroup analyses, the association was more prominent in the presence of hypercholesterolemia (+8.11 mm Hg, P=0.008) for central systolic blood pressure and in the presence of overweight and obesity (-4.89%, P=0.009), diabetes and prediabetes (-6.26%, P=0.10) or current smoking (-6.68%, P=0.045) for central-to-brachial pulse pressure ratio. In conclusion, plasma AGE concentration is independently associated with central systolic blood pressure and pulse pressure amplification, especially in the presence of several modifiable cardiovascular risk factors.

Interdialytic ambulatory blood pressure in patients with intradialytic hypertension.

PubMed

Van Buren, Peter N; Toto, Robert; Inrig, Jula K

2012-01-01

Hypertension is common in hemodialysis patients and contributes to this population's high risk for cardiovascular morbidity and mortality. Patients with intradialytic hypertension, or increases in blood pressure during hemodialysis, have been shown to have the highest risk for these outcomes. The purpose of this review is to describe new findings that shed light on the epidemiology and pathophysiology of intradialytic hypertension and discuss how a better understanding of these mechanisms may lead to improved blood pressure management and outcomes in hemodialysis patients. Our laboratory demonstrated that intradialytic hypertension occurs at least sporadically in most hemodialysis patients, but in 25% of patients it occurs in over 31% of their hemodialysis treatments. We also identified that, compared with hemodialysis patients without intradialytic hypertension, those with intradialytic hypertension have worse endothelial cell function and have higher interdialytic ambulatory blood pressure. Pilot study data show that carvedilol reduces the frequency of intradialytic hypertension and improves endothelial cell dysfunction. Intradialytic hypertension is associated with increased morbidity and mortality, impaired endothelial cell function, and higher overall blood pressure burden. Further investigation is required to determine whether interventions aimed at preventing or treating intradialytic hypertension improve long-term outcomes.

Two ways to feel the pressure: an endothelial Ca(2+) entry channel with dual mechanosensitivity.

PubMed

Groschner, Klaus

2002-01-01

One impressive function of the vascular endothelium is its ability to adjust the release of vasoactive mediators such as NO and PGI(2) almost instantaneously to changes in blood flow or blood pressure. Besides this fast feedback response to hemodynamic alterations, the endothelium is subject to long-term adaptations that are crucial for prevention of pathological processes such as atherogenesis. Among the various signals that are sensed by endothelial cells, mechanical forces which arise from pulsatile blood flow are probably most important for fast as well as long-term control of blood vessel function by the endothelium.

Waist circumference, body mass index, serum uric acid, blood sugar, and triglyceride levels are important risk factors for abnormal liver function tests in the Taiwanese population.

PubMed

Hsieh, Meng-Hsuan; Lin, Wen-Yi; Chien, Hsu-Han; Chien, Li-Ho; Huang, Chao-Kuan; Yang, Jeng-Fu; Chang, Ning-Chia; Huang, Chung-Feng; Wang, Chao-Ling; Chuang, Wan-Long; Yu, Ming-Lung; Dai, Chia-Yen; Ho, Chi-Kung

2012-09-01

Several studies have found that metabolic syndrome and uric acid level are related to abnormal liver function test results. The aim of this study was to explore the associations of risk factors [including blood pressure, blood sugar, total cholesterol, triglyceride, uric acid, waist circumference and body mass index (BMI) measurements] with abnormal liver function in the Taiwanese population.In total, 11,411 Taiwanese adults were enrolled in this study. Blood pressure was assessed according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure criteria, fasting blood sugar level according to the Bureau of Health Promotion, Department of Health, R.O.C., criteria, total cholesterol and triglyceride levels according to the Third Report of the National Cholesterol Education Program Adult Treatment Panel III criteria, BMI according to the Asia-Pacific criteria, and waist circumference according to the Revised Diagnostic Criteria of Metabolic Syndrome in Taiwan. The prevalence of a past history of hypertension and diabetes mellitus was 17.7% and 6.5%, respectively, and the rates of abnormal measurements of blood pressure, BMI, waist circumference, fasting blood sugar, triglyceride, total cholesterol, uric acid (male/female), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were 76.2%, 67.6%, 40.0%, 28.6%, 30.6%, 57.3%, 37.9%/21.9%, 14.6% and 21.3%, respectively. Multivariate analysis showed that waist circumference, BMI, serum uric acid, blood sugar, and triglyceride levels were related to abnormal AST and ALT (p<0.05), but the odds ratio for waist circumference was larger than that for BMI. In conclusion, waist circumference, BMI, serum uric acid, blood sugar, and triglyceride levels are important risk factors for abnormal AST and ALT readings in Taiwanese adults. Waist circumference might be a better indicator of risk of abnormal liver function than BMI. Copyright © 2012. Published by Elsevier B.V.

Left ventricular function during lower body negative pressure

NASA Technical Reports Server (NTRS)

Ahmad, M.; Blomqvist, C. G.; Mullins, C. B.; Willerson, J. T.

1977-01-01

The response of the human left ventricle to lower body negative pressure (LBNP) and the relation between left ventricular function and hemodynamic response were investigated. Ventricular function curves relating stroke volume to end-diastolic volume were obtained in 12 normal men. Volume data were derived from echocardiographic measurements of left ventricular end-systolic and end-diastolic diameters at rest and during lower body negative pressure (LBNP) at minus 40 mm Hg. End-diastolic volume decreased by 19% and stroke volume by 22%. There were no significant changes in heart rate, arterial blood pressure, or end-systolic volume. Thus, moderate levels of LBNP significantly reduce preload and stroke volume without affecting contractile state. The absence of significant changes in heart rate and arterial blood pressure in the presence of a significant reduction in stroke volume is consistent with an increase in systemic peripheral resistance mediated by low-pressure baroreceptors.

Cocoa, blood pressure, and vascular function.

PubMed

Sudano, Isabella; Flammer, Andreas J; Roas, Susanne; Enseleit, Frank; Ruschitzka, Frank; Corti, Roberto; Noll, Georg

2012-08-01

The consumption of a high amount of fruits and vegetables was found to be associated with a lower risk of coronary heart disease and stroke. Epidemiologically, a similar relationship has been found with cocoa, a naturally polyphenol-rich food. Obviously, double blind randomized studies are difficult to perform with cocoa and chocolate, respectively. However, intervention studies strongly suggest that cocoa has several beneficial effects on cardiovascular health, including the lowering of blood pressure, the improvement of vascular function and glucose metabolism, and the reduction of platelet aggregation and adhesion. Several potential mechanisms through which cocoa might exert its positive effects have been proposed, among them activation of nitric oxide synthase, increased bioavailability of nitric oxide as well as antioxidant, and anti-inflammatory properties. It is the aim of this review to summarize the findings of cocoa and chocolate on blood pressure and vascular function.

Association of morning blood pressure surge with carotid intima-media thickness and cardiac dysfunction in patients with cardiac syndrome-X.

PubMed

Mahfouz, Ragab A; Goda, Mohammad; Galal, Islam; Ghareb, Mohamed S

2018-05-23

Background & hypothesis: We hypothesized that exaggerated morning blood pressure surge, may contribute in cardiac dysfunction and arterial stiffness in patients with cardiac syndrome X. Thus we investigated the impact of morning blood pressure surge on cardiac function and carotid intima-media thickness in subjects with cardiac syndrome X. We studied patients with cardiac syndrome X using ambulatory blood pressure monitoring and investigated the association of morning blood pressure surge with carotid intima thickness, left atrial volume index and left ventricular filling (E/e'). Seventy patients with cardiac syndrome X were enrolled for the study and compared with 70 age and sex matched controls. Patients with cardiac syndrome X were stratified based on the systolic morning blood pressure surge value of control subjects to patients with exaggerated blood pressure surge (n = 42) and those with normal morning blood pressure surge (n = 28). Basal heart rate (p < .05), high sensitive C-reactive protein (p < .01), left atrial volume index (p < .01), E/e' (p < .01); carotid intima-media thickness (p < .001) and percentage of detected plaque (p < .005) were significantly higher in patients with exaggerated morning blood pressure surge group than those with morning blood pressure surge group. Morning blood pressure surge was significantly correlated with carotid intima-media thickness, high sensitive C-reactive protein, left atrial volume index and E/e' ratio in patients with cardiac syndrome X. In multivariate analysis, exaggerated morning blood pressure surge was the only independent predictor of increased carotid intima-media thickness (OR = 2.379; p < .001), and diastolic dysfunction (OR = 2.464; p < .001) in patients with cardiac syndrome X. Our data suggest that excessive morning blood pressure surge is an independent predictor for arterial stiffness and diastolic dysfunction in patients with cardiac syndrome X.

Blood pressure interacts with APOE ε4 to predict memory performance in a midlife sample

PubMed Central

Oberlin, Lauren E.; Manuck, Stephen B.; Gianaros, Peter J.; Ferrell, Robert E.; Muldoon, Matthew F.; Jennings, J. Richard; Flory, Janine D.; Erickson, Kirk I.

2015-01-01

Objective Elevated blood pressure and the Apolipoprotein ε4 allele (APOE ε4) are independent risk factors for Alzheimer’s disease. We sought to determine whether the combined presence of the APOE ε4 allele and elevated blood pressure is associated with lower cognitive performance in cognitively healthy middle-aged adults. Methods A total of 975 participants aged 30–54 (mean age = 44.47) were genotyped for APOE. Cardiometabolic risk factors including blood pressure, lipids, and glucose were assessed and cognitive function was measured using the Trail Making Test and the Visual Reproduction and Logical Memory subtests from the Wechsler Memory Scale. Results Multivariable regression analysis showed that the association between APOE ε4 and episodic memory performance varied as a function of systolic blood pressure (SBP), such that elevated SBP was predictive of poorer episodic memory performance only in APOE ε4 carriers (β = −.092; t = −2.614; p = .009). Notably, this association was apparent at prehypertensive levels (≥ 130 mm Hg), even after adjusting for physical activity, depression, smoking, and other cardiometabolic risk factors. Conclusions The joint presence of APOE ε4 and elevated SBP, even at prehypertensive levels, is associated with lower cognitive performance in healthy, middle-aged adults. Results of this study suggest that the combination of APOE ε4 and elevated SBP may synergistically compromise memory function well before the appearance of clinically significant impairments. Interventions targeting blood pressure control in APOE ε4 carriers during midlife should be studied as a possible means to reduce the risk of cognitive decline in genetically susceptible samples. PMID:25730733

Roles of Arterial Stiffness and Blood Pressure in Hypertension-Associated Cognitive Decline in Healthy Adults.

PubMed

Hajjar, Ihab; Goldstein, Felicia C; Martin, Greg S; Quyyumi, Arshed A

2016-01-01

Although there is strong evidence that hypertension leads to cognitive decline, especially in the executive domain, the relationship between blood pressure and cognition has been conflicted. Hypertension is characterized by blood pressure elevation and increased arterial stiffness. We aimed at investigating whether arterial stiffness would be superior to blood pressure in predicting cognitive decline and explaining the hypertension-executive decline association. A randomly selected asymptomatic population (n=591, age=49.2 years, 70% women, 27% black, and education=18 years) underwent annual vascular and cognitive assessments. Cognition was assessed using computerized versions commonly used cognitive tests, and principal component analysis was used for deriving cognitive scores for executive function, memory, and working memory. Arterial stiffness was measured by carotid-femoral pulse wave velocity (PWV). Higher PWV, but not blood pressure, was associated with a steeper decline in executive (P=0.0002), memory (P=0.05), and working memory (P=0.02) scores after adjusting for demographics, education, and baseline cognitive performance. This remained true after adjusting for hypertension. Hypertension was associated with greater decline in executive score (P=0.0029) and those with combined hypertension and elevated PWV (>7 m/s) had the greatest decline in executive score (P value hypertension×PWV=0.02). PWV explained the association between hypertension and executive function (P value for hypertension=0.0029 versus 0.24 when adjusting for PWV). In healthy adults, increased arterial stiffness is superior to blood pressure in predicting cognitive decline in all domains and in explaining the hypertension-executive function association. Arterial stiffness, especially in hypertension, may be a target in the prevention of cognitive decline. © 2015 American Heart Association, Inc.

The acute effect of coffee on endothelial function and glucose metabolism following a glucose load in healthy human volunteers.

PubMed

Boon, Evan A J; Croft, Kevin D; Shinde, Sujata; Hodgson, Jonathan M; Ward, Natalie C

2017-09-20

A diet rich in plant polyphenols has been suggested to reduce the incidence of cardiovascular disease and type 2 diabetes mellitus, in part, via improvements in endothelial function. Coffee is a rich source of phenolic compounds including the phenolic acid, chlorogenic acid (CGA). The aim of the study was to investigate the effect of coffee as a whole beverage on endothelial function, blood pressure and blood glucose concentration. Twelve healthy men and women were recruited to a randomised, placebo-controlled, cross-over study, with three treatments tested: (i) 18 g of ground caffeinated coffee containing 300 mg CGA in 200 mL of hot water, (ii) 18 g of decaffeinated coffee containing 287 mg CGA in 200 mL of hot water, and (iii) 200 mL of hot water (control). Treatment beverages were consumed twice, two hours apart, with the second beverage consumed simultaneously with a 75 g glucose load. Blood pressure was recorded and the finger prick glucose test was performed at time = 0 and then every 30 minutes up to 2 hours. Endothelial function, assessed using flow-mediated dilatation (FMD) of the brachial artery, was measured at 1 hour and a blood sample taken at 2 hours to measure plasma nitrate/nitrite and 5-CGA concentrations. The FMD response was significantly higher in the caffeinated coffee group compared to both decaffeinated coffee and water groups (P < 0.001). There was no significant difference in the FMD response between decaffeinated coffee and water. Blood glucose concentrations and blood pressure were not different between the three treatment groups. In conclusion, the consumption of caffeinated coffee resulted in a significant improvement in endothelial function, but there was no evidence for benefit regarding glucose metabolism or blood pressure. Although the mechanism has yet to be elucidated the results suggest that coffee as a whole beverage may improve endothelial function, or that caffeine is the component of coffee responsible for improving FMD.

The Relationships between Air Exposure, Negative Pressure and Hemolysis

PubMed Central

Pohlmann, Joshua R.; Toomasian, John M.; Hampton, Claire E.; Cook, Keith E.; Annich, Gail M.; Bartlett, Robert H.

2013-01-01

The purpose of this study was to describe the hemolytic effects of both negative pressure and an air-blood interface independently and in combination in an in-vitro static blood model. Samples of fresh ovine or human blood (5 mL) were subjected to a bubbling air interface (0–100 mL/min) or negative pressure (0–600 mmHg) separately, or in combination, for controlled periods of time, and analyzed for hemolysis. Neither negative pressure nor an air interface alone increased hemolysis. However, when air and negative pressure were combined, hemolysis increased as a function of negative pressure, the air interface, and time. Moreover, when blood samples were exposed to air prior to initiating the test, hemolysis was 4–5 times greater than samples not pre-exposed to air. When these experiments were repeated using freshly drawn human blood the same phenomena were observed, but the hemolysis was significantly higher than that observed in sheep blood. In this model, hemolysis is caused by combined air and negative pressure and is unrelated to either factor alone. PMID:19730004

Effects of short-term addition of NSAID to diuretics and/or RAAS-inhibitors on blood pressure and renal function.

PubMed

Nygård, Peder; Jansman, Frank G A; Kruik-Kollöffel, Willemien J; Barnaart, Alex F W; Brouwers, Jacobus R B J

2012-06-01

The combined post-operative use of diuretics and/or renin-angiotensin-aldosterone system (RAAS) inhibitors may increase the risk of nonsteroidal anti-inflammatory drug (NSAID) associated renal failure because of a drug-drug interaction. The aim of this study was to investigate the effect of the short-term (<4 days) post-operative combined use of NSAIDs with diuretics and/or RAAS inhibitors on renal function and blood pressure. One teaching hospital in the Netherlands. The study-design was a prospective, observational cohort-study. Based on postoperative treatment with NSAIDs, the intervention-group was compared to a control-group (no NSAIDs treatment). Systolic blood pressure and renal function expressed by the estimated glomular filtration rate (eGFR) calculated with the modification of renal desease formula. 97 patients were included in the intervention-group, 53 patients in the control-group. Patient characteristics were comparable except for one variable: 'combined use of a diuretic with a RAAS inhibitor' which was higher in the control-group (62 vs. 43 %, p = 0.046). Odds ratio for clinically relevant increase in systolic blood pressure was 0.66 (CI95 % 0.3-1.5). Odds ratio for clinical relevant decrease in renal function was 2.44 (CI95 % 1.1-5.2). On day 4 eGFR of 3 patients in the intervention- and 1 in the control-group was <50 ml/min/1.73 m(2). Odds ratios showed no significant difference of a clinically relevant increase in systolic blood pressure but showed a higher risk for a clinically relevant decrease in renal function in the intervention group. However this decrease resulted in a relevant impaired renal function (<50 ml/min/1.73 m(2)) in only 3 patients in the interventiongroup and 1 patient in the control-group. In the post-operative patient, without preexisting impaired renal function, concurrent diuretics and/or renin-angiotensinaldosterone system inhibitor therapy can be combined with short-term NSAID treatment.

Continuous and interval training programs using deep water running improves functional fitness and blood pressure in the older adults.

PubMed

Reichert, Thaís; Kanitz, Ana Carolina; Delevatti, Rodrigo Sudatti; Bagatini, Natália Carvalho; Barroso, Bruna Machado; Kruel, Luiz Fernando Martins

2016-02-01

This study aimed to investigate the effects of two periodized training programs of deep water running on functional fitness and blood pressure in the older adults. Thirty-six individuals were divided into continuous group (CONT) and interval group (INT). Both groups were trained for 28 weeks (twice weekly). Measures were performed before the training period, after 12 weeks and training period. Two-way ANOVA and post hoc of Bonferroni were used (α = 0.05). There were no differences between groups in functional tests, with the exception of the flexibility of the upper limbs, in which the INT group showed the highest values. There was a significant improvement in both groups of foot up-and-go test (CONT 6.45 to 5.67; INT 6.59 to 5.78, in seconds), flexibility of lower limbs (CONT -4.76 to -0.61; INT 0.54 to 4.63, in centimeters), strength of upper (CONT 18.76 to 27.69; INT 18.66 to 26.58, in repetitions) and lower limbs (CONT 14.46 to 21.23; INT 14.40 to 21.58, in repetitions), and 6-min walk (CONT 567.50 to 591.16; INT 521.41 to 582.77, in meters). No differences were shown between groups for systolic blood pressure; however, diastolic blood pressure remained higher in CONT during all training. The blood pressure decreased significantly in both groups after the training (CONT 142 ± 16/88 ± 3 to 125 ± 14/77 ± 7 mmHg; INT 133 ± 15/75 ± 7 to 123 ± 17 and 69 ± 11 mmHg). Both programs of deep water running training promoted improvements of similar magnitude in all parameters of functional fitness, with the exception of flexibility of upper limbs, and decreased blood pressure in the older individuals.

5D.07: THE IMPACT OF FLAVONOL-RICH DARK CHOCOLATE ON BLOOD PRESSURE AND VASCULAR FUNCTION IN HEALTHY SUBJECTS.

PubMed

Heuten, H; Van Ackeren, K; Hoymans, V; Wouters, K; Goovaerts, I; Conraads, V; Vrints, C

2015-06-01

Flavanoids may have a beneficial effect on blood pressure (BP) and endothelial function. There is however, limited data on this effect during a longer period (8 weeks) and no data on the effect on EPC (endothelial progenitor cells) in healthy subjects. Healthy, non-smoking, male and female volunteers aged 35-65 year with no history of diabetes or cardiovascular disease and with normal or mild hypertensive blood pressure (<160/100 mmHg) were included. Subjects could not take any medication affecting blood pressure or endothelial function. The subjects were randomised (double-blind) in two groups: Group 1(n = 25): daily consuming 20 gram of high-flavanol dark chocolate (High-DC). Group 2 (n = 26): daily consuming 20 gram of low-flavanol dark chocolate (Low-DC). At week 0,4,6,7 and 8 blood pressure was assessed in all subjects, and endothelial function (FMD, flow mediated dilation) in a subgroup. A blood sample was taken in each subject at week 0 and 8 for measuring glucose, lipids and EPC. Baseline characteristics were comparable between both groups. There was a decrease in systolic and diastolic blood pressure over time in both groups, however at 8 weeks there was no statistically significant difference between groups (delta SBP -2.17  + /-8.53 mmHg in gr 1 versus -4.06 + /-8.05 mmHg in gr 2, p = 0.4; delta DBP -3.97  + /-7.1 mmHg in gr 1 versus -4.67  + /-5.99 mmHg in gr 2, p = 0.7).FMD was performed in 9 subjects from each group, no significant difference was noted between both groups over time (delta FMD gr 1: -3.50  + /- 6.00 % versus gr 2: + 0.12  + /- 2.51 %, p = 0.06). EPC values did not differ between groups at baseline (T0) and at the end of the study (T8) (ISHAGE count (T8-T0): gr1: 3.23 (-68.01 - 41.71) versus gr 2: -9.23 (-57.59 - 17.28), p = 0.4). Glucose and lipids were comparable between both groups at baseline and at the end of the study (p = ns). In this study, no beneficial effect was noticed in favour of the consumption of flavanol-rich dark chocolate during 8 weeks on blood pressure or vascular function, in healthy subjects.

Relationship between osmotic pressure of the blood and secretion of sweat

NASA Technical Reports Server (NTRS)

Montuori, A.

1978-01-01

Experiments with cats show that the thermic secretion of sweat represents a specific case of a general law: The central nervous apparatus that controls the secretion of sweat begins to function when the osmotic pressure of the blood drops below normal.

Analysis on influencing factors of abnormal renal function in elderly patients with type 2 diabetes mellitus.

PubMed

Chai, Tao; Zhang, Dawei; Li, Zhongxin

2018-04-12

To investigate the related influencing factors of abnormal renal function in elderly in patients with type 2 diabetes mellitus (T2DM) and their clinical significance. The clinical data of elderly T2DM patients hospitalized in Beijing Luhe Hospital from January 2013 to June2016 were retrospectively analyzed. According to their glomerular filtration rate (GFR) levels, these patients were divided into GFR ≥90 mL/min/1.73m2 group (Group A), GFR =60-90 mL/min/1.73m2 group (Group B), and GFR <60 mL/min/1.73m2 group (Group C, i.e., abnormal renal function group). Clinical and laboratory indicators were compared among each group. A total of 614 elderly T2DM patients were collected and divided into Group A (n=186), Group B (n=280) and Group C (n=148, 24.10%). Among them, patients clinically diagnosed with diabetic nephropathy (DN) accounted for 13.68%, and those complicated with high blood pressure (HBP) accounted for 61.40%. In Group C, DN accounted for only 29.73%. In elderly T2DM patients, HBP course, systolic blood pressure (SBP), diastolic blood pressure (DBP), 2h postprandial blood glucose (2hPBG), serum total cholesterol (TC) and blood uric acid (BUA) were independent influencing factors associated with abnormal renal function, among which HBP had a more significant impact on abnormal renal function. With the increase of blood pressure (BP) level, the extension in the course of DM, the increase in urinary albumin/creatinine (Alb/Cr) and the decrease in GFR, the incidence rate of abnormal renal function was increased. HBP course, SBP, DBP, 2hPBG, TC and BUA are independent risk factors for abnormal renal function in elderly patients with T2DM. Well-controlled BP and blood glucose are protective factors, and a comprehensive treatment targeting to the above influencing factors has important clinical significance in preventing and delaying the occurrence and development of abnormal renal function.

BLOOD PRESSURE REGULATION III: WHAT HAPPENS WHEN ONE SYSTEM MUST SERVE TWO MASTERS: TEMPERATURE AND PRESSURE REGULATION?

PubMed Central

Kenney, W. Larry; Stanhewicz, Anna E.; Bruning, Rebecca S.; Alexander, Lacy M.

2013-01-01

When prolonged intense exercise is performed at high ambient temperatures, cardiac output must meet dual demands for increased blood flow to contracting muscle and to the skin. The literature has commonly painted this scenario as a fierce competition, wherein one circulation preserves perfusion at the expense of the other, with the regulated maintenance of blood pressure as the ultimate goal. This review redefines this scenario as commensalism, an integrated balance of regulatory control where one circulation benefits with little functional effect on the other. In young, healthy subjects, arterial pressure rarely falls to any great extent during either extreme passive heating or prolonged dynamic exercise in the heat. Nor does body temperature rise disproportionately due to a compromised skin blood flow. Rather, it often takes the superimposition of additional stressors – e.g., dehydration or simulated hemorrhage – upon heat stress to substantially impact blood pressure regulation. PMID:23636697

Blood pressure regulation III: what happens when one system must serve two masters: temperature and pressure regulation?

PubMed

Kenney, W Larry; Stanhewicz, Anna E; Bruning, Rebecca S; Alexander, Lacy M

2014-03-01

When prolonged intense exercise is performed at high ambient temperatures, cardiac output must meet dual demands for increased blood flow to contracting muscle and to the skin. The literature has commonly painted this scenario as a fierce competition, wherein one circulation preserves perfusion at the expense of the other, with the regulated maintenance of blood pressure as the ultimate goal. This review redefines this scenario as commensalism, an integrated balance of regulatory control where one circulation benefits with little functional effect on the other. In young, healthy subjects, arterial pressure rarely falls to any great extent during either extreme passive heating or prolonged dynamic exercise in the heat, nor does body temperature rise disproportionately due to a compromised skin blood flow. Rather, it often takes the superimposition of additional stressors--e.g., dehydration or simulated hemorrhage--upon heat stress to substantially impact blood pressure regulation.

[Hypertensive crisis in infancy and childhood].

PubMed

Wirbelauer, J; Strotmann, J; Kirchhoff, A; Darge, K; Thomas, W

2008-01-01

The extended physical examination of a patient includes measurement of blood pressure. In infancy and childhood the blood pressure measurement may be difficult due to an uncooperative and restless patient. In a 16-month-old girl apparently unmeasurable blood pressure was a hypertensive crisis with systolic blood pressure of more than 200 mmHg. The cause of the hypertension was found to be a nephroblastoma. In the case of rapidly progressive arterial hypertension in another 16-month-old girl with left ventricular dilatation and reduced function was a consequence of kidney dysplasia. Headache attacks lead to diagnosis of a subtotal coarctation of the aortic isthmus in a 17-year-old boy. Hypertensive crisis in infancy, childhood and adolescence is discussed based on these case reports. Special features of blood pressure measurement in the pediatric age group, pathogenesis of hypertensive crisis and the potential therapies are discussed incorporating a brief review of the literature.

SRC-1 regulates blood pressure and aortic stiffness in female mice

USDA-ARS?s Scientific Manuscript database

Framingham Heart Study suggests that dysfunction of steroid receptor coactivator-1 may be involved in the development of hypertension. However, there is no functional evidence linking steroid receptor coactivator-1 to the regulation of blood pressure. We used immunohistochemistry to map the expressi...

Transfer function analysis of dynamic cerebral autoregulation in humans

NASA Technical Reports Server (NTRS)

Zhang, R.; Zuckerman, J. H.; Giller, C. A.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

1998-01-01

To test the hypothesis that spontaneous changes in cerebral blood flow are primarily induced by changes in arterial pressure and that cerebral autoregulation is a frequency-dependent phenomenon, we measured mean arterial pressure in the finger and mean blood flow velocity in the middle cerebral artery (VMCA) during supine rest and acute hypotension induced by thigh cuff deflation in 10 healthy subjects. Transfer function gain, phase, and coherence function between changes in arterial pressure and VMCA were estimated using the Welch method. The impulse response function, calculated as the inverse Fourier transform of this transfer function, enabled the calculation of transient changes in VMCA during acute hypotension, which was compared with the directly measured change in VMCA during thigh cuff deflation. Beat-to-beat changes in VMCA occurred simultaneously with changes in arterial pressure, and the autospectrum of VMCA showed characteristics similar to arterial pressure. Transfer gain increased substantially with increasing frequency from 0.07 to 0.20 Hz in association with a gradual decrease in phase. The coherence function was > 0.5 in the frequency range of 0.07-0.30 Hz and < 0.5 at < 0.07 Hz. Furthermore, the predicted change in VMCA was similar to the measured VMCA during thigh cuff deflation. These data suggest that spontaneous changes in VMCA that occur at the frequency range of 0.07-0.30 Hz are related strongly to changes in arterial pressure and, furthermore, that short-term regulation of cerebral blood flow in response to changes in arterial pressure can be modeled by a transfer function with the quality of a high-pass filter in the frequency range of 0.07-0.30 Hz.

Resveratrol Treatment Normalizes the Endothelial Function and Blood Pressure in Ovariectomized Rats.

PubMed

Fabricio, Victor; Oishi, Jorge Camargo; Biffe, Bruna Gabriele; Ruffoni, Leandro Dias Gonçalves; Silva, Karina Ana da; Nonaka, Keico Okino; Rodrigues, Gerson Jhonatan

2017-02-01

Despite knowing that resveratrol has effects on blood vessels, blood pressure and that phytostrogens can also improve the endothelium-dependent relaxation/vasodilation, there are no reports of reveratrol's direct effect on the endothelial function and blood pressure of animals with estrogen deficit (mimicking post-menopausal increased blood pressure). To verify the effect of two different periods of preventive treatment with resveratrol on blood pressure and endothelial function in ovariectomized young adult rats. 3-month old female Wistar rats were used and distributed in 6 groups: intact groups with 60 or 90 days, ovariectomized groups with 60 or 90 days, and ovariectomized treated with resveratrol (10 mg/kg of body weight per day) for 60 or 90 days. The number of days in each group corresponds to the duration of the experimental period. Vascular reactivity study was performed in abdominal aortic rings, systolic blood pressure was measured and serum nitric oxide (NO) concentration was quantified. Ovariectomy induced blood pressure increase 60 and 90 days after surgery, whereas the endothelial function decreased only 90 days after surgery, with no difference in NO concentration among the groups. Only longer treatment (90 days) with resveratrol was able to improve the endothelial function and normalize blood pressure. Our results suggest that 90 days of treatment with resveratrol is able to improve the endothelial function and decrease blood pressure in ovariectomized rats. Apesar de se saber que o resveratrol apresenta efeitos sobre a pressão arterial e os vasos sanguíneos, e que os fitoestrógenos podem melhorar o relaxamento/vasodilatação dependente do endotélio, não há relatos do efeito direto do resveratrol sobre a pressão arterial e a função endotelial em animais com deficiência de estrógeno (mimetizando a pressão arterial aumentada pós-menopausa). Verificar o efeito de dois diferentes períodos de tratamento preventivo com resveratrol sobre a pressão arterial e a função endotelial em ratas adultas jovens ovariectomizadas. Foram utilizadas ratas Wistar com 3 meses de idade, distribuídas em 6 grupos: grupos intactas com 60 ou 90 dias, grupos ovariectomizadas com 60 ou 90 dias, grupos ovariectomizadas e tratadas com resveratrol na dose de 10mg/kg de massa corporal por dia, durante 60 ou 90 dias, sendo o número de dias em cada grupo relativo à duração do período experimental. Foi realizado um estudo de reatividade vascular em anéis da aorta abdominal, mensurada a pressão arterial sistólica e quantificada a concentração sérica de óxido nítrico (NO). A ovariectomia induziu aumento da pressão arterial 60 e 90 dias após a cirurgia, enquanto a função endotelial decaiu apenas após 90 dias, e não houve diferença na concentração de NO entre os grupos. Apenas o tratamento prolongado com resveratrol (90 dias) foi capaz de melhorar a função endotelial e normalizar a pressão arterial. Nossos resultados sugerem que o tratamento por 90 dias com resveratrol é capaz de melhorar a função endotelial e diminuir a pressão sanguínea em ratas ovariectomizadas.

An association of platelet indices with blood pressure in Beijing adults: Applying quadratic inference function for a longitudinal study.

PubMed

Yang, Kun; Tao, Lixin; Mahara, Gehendra; Yan, Yan; Cao, Kai; Liu, Xiangtong; Chen, Sipeng; Xu, Qin; Liu, Long; Wang, Chao; Huang, Fangfang; Zhang, Jie; Yan, Aoshuang; Ping, Zhao; Guo, Xiuhua

2016-09-01

The quadratic inference function (QIF) method becomes more acceptable for correlated data because of its advantages over generalized estimating equations (GEE). This study aimed to evaluate the relationship between platelet indices and blood pressure using QIF method, which has not been studied extensively in real data settings.A population-based longitudinal study was conducted in Beijing from 2007 to 2012, and the median of follow-up was 6 years. A total of 6515 cases, who were aged between 20 and 65 years at baseline and underwent routine physical examinations every year from 3 Beijing hospitals were enrolled to explore the association between platelet indices and blood pressure by QIF method. The original continuous platelet indices were categorized into 4 levels (Q1-Q4) using the 3 quartiles of P25, P50, and P75 as a critical value. GEE was performed to make a comparison with QIF.After adjusting for age, usage of drugs, and other confounding factors, mean platelet volume was negatively associated with diastolic blood pressure (DBP) (Equation is included in full-text article.)in males and positively linked with systolic blood pressure (SBP) (Equation is included in full-text article.). Platelet distribution width was negatively associated with SBP (Equation is included in full-text article.). Blood platelet count was associated with DBP (Equation is included in full-text article.)in males.Adults in Beijing with prolonged exposure to extreme value of platelet indices have elevated risk for future hypertension and evidence suggesting using some platelet indices for early diagnosis of high blood pressure was provided.

Adaptation, allometry, and hypertension.

PubMed

Weder, A B; Schork, N J

1994-08-01

Essential hypertension is a "disease of civilization" but has a clear genetic component. From an evolutionary perspective, persistence in the human genome of elements capable of raising blood pressure presupposes their adaptive significance. Recently, two hypotheses that explicitly appeal to selectionist arguments, the "slavery" and "thrifty gene" theories, have been forwarded. We find neither completely successful, and we advance an alternative explanation of the adaptive importance of genes responsible for hypertension. We propose that blood pressure rises during childhood and adolescence to subserve homeostatic needs of the organism. Specifically, we contend that blood pressure is a flexible element in the repertoire of renal homeostatic mechanisms serving to match renal function to growth. The effect of modern diet and lifestyle on human growth stimulates earlier and more vigorous development, straining biologically necessary relationships between renal and general somatic growth and requiring compensation via homeostatic mechanisms preserved during evolution. Prime among such mechanisms is blood pressure, which rises as a compensation to maintain renal function in the face of greater growth. Since virtually all members of acculturated societies share in the modern lifestyle, the demands imposed by accelerated growth and development result in a populational shift to higher blood pressures, with a consequent increase in the prevalence of hypertension. We propose that hypertension is the product of maladaptation of highly genetically conserved mechanisms subserving important biological homeostatic needs. Elucidation of the mechanisms underlying hypertension will require approaches that examine the developmental processes linking growth to blood pressure.

Understanding the physiology of mindfulness: aortic hemodynamics and heart rate variability.

PubMed

May, Ross W; Bamber, Mandy; Seibert, Gregory S; Sanchez-Gonzalez, Marcos A; Leonard, Joseph T; Salsbury, Rebecca A; Fincham, Frank D

2016-01-01

Data were collected to examine autonomic and hemodynamic cardiovascular modulation underlying mindfulness from two independent samples. An initial sample (N = 185) underwent laboratory assessments of central aortic blood pressure and myocardial functioning to investigated the association between mindfulness and cardiac functioning. Controlling for religiosity, mindfulness demonstrated a strong negative relationship with myocardial oxygen consumption and left ventricular work but not heart rate or blood pressure. A second sample (N = 124) underwent a brief (15 min) mindfulness inducing intervention to examine the influence of mindfulness on cardiovascular autonomic modulation via blood pressure variability and heart rate variability. The intervention had a strong positive effect on cardiovascular modulation by decreasing cardiac sympathovagal tone, vasomotor tone, vascular resistance and ventricular workload. This research establishes a link between mindfulness and cardiovascular functioning via correlational and experimental methodologies in samples of mostly female undergraduates. Future directions for research are outlined.

Antihypertensive therapy and endothelial function.

PubMed

Nadar, Sunil; Blann, Andrew D; Lip, Gregory Y H

2004-01-01

The benefits of treating hypertension in terms of reduction of morbidity and mortality are well established. However, it is debatable whether this benefit is derived entirely from the effects of a reduced blood pressure or whether these agents exert effects over and above blood pressure reduction on the endothelium. Hypertension is associated with adverse changes (whether damage or dysfunction) in the endothelium. Indeed, endothelial damage/dysfunction has have been demonstrated to be a reliable prognostic indicator of future cardiovascular events in hypertension. Of the various drug classes, calcium channel blockers and the ACE inhibitors have significant direct effects on the endothelium. This is in contrast to the beta blockers and alpha adrenergic blockers that appear to indirectly influence endothelial function solely as a result of lowered blood pressure. Antioxidants may have a beneficial effect on endothelial function as well, although their clinical use does not seem to translate into clinical benefit.

Effect of renal denervation on dynamic autoregulation of renal blood flow.

PubMed

DiBona, Gerald F; Sawin, Linda L

2004-06-01

Vasoconstrictor intensities of renal sympathetic nerve stimulation elevate the renal arterial pressure threshold for steady-state stepwise autoregulation of renal blood flow. This study examined the tonic effect of basal renal sympathetic nerve activity on dynamic autoregulation of renal blood flow in rats with normal (Sprague-Dawley and Wistar-Kyoto) and increased levels of renal sympathetic nerve activity (congestive heart failure and spontaneously hypertensive rats). Steady-state values of arterial pressure and renal blood flow before and after acute renal denervation were subjected to transfer function analysis. Renal denervation increased basal renal blood flow in congestive heart failure (+35 +/- 3%) and spontaneously hypertensive rats (+21 +/- 3%) but not in Sprague-Dawley and Wistar-Kyoto rats. Renal denervation significantly decreased transfer function gain (i.e., improved autoregulation of renal blood flow) and increased coherence only in spontaneously hypertensive rats. Thus vasoconstrictor intensities of renal sympathetic nerve activity impaired the dynamic autoregulatory adjustments of the renal vasculature to oscillations in arterial pressure. Renal denervation increased renal blood flow variability in spontaneously hypertensive rats and congestive heart failure rats. The contribution of vasoconstrictor intensities of basal renal sympathetic nerve activity to limiting renal blood flow variability may be important in the stabilization of glomerular filtration rate.

Renalase is a novel, soluble monoamine oxidase that regulates cardiac function and blood pressure

PubMed Central

Xu, Jianchao; Li, Guoyong; Wang, Peili; Velazquez, Heino; Yao, Xiaoqiang; Li, Yanyan; Wu, Yanling; Peixoto, Aldo; Crowley, Susan; Desir, Gary V.

2005-01-01

The kidney not only regulates fluid and electrolyte balance but also functions as an endocrine organ. For instance, it is the major source of circulating erythropoietin and renin. Despite currently available therapies, there is a marked increase in cardiovascular morbidity and mortality among patients suffering from end-stage renal disease. We hypothesized that the current understanding of the endocrine function of the kidney was incomplete and that the organ might secrete additional proteins with important biological roles. Here we report the identification of a novel flavin adenine dinucleotide–dependent amine oxidase (renalase) that is secreted into the blood by the kidney and metabolizes catecholamines in vitro (renalase metabolizes dopamine most efficiently, followed by epinephrine, and then norepinephrine). In humans, renalase gene expression is highest in the kidney but is also detectable in the heart, skeletal muscle, and the small intestine. The plasma concentration of renalase is markedly reduced in patients with end-stage renal disease, as compared with healthy subjects. Renalase infusion in rats caused a decrease in cardiac contractility, heart rate, and blood pressure and prevented a compensatory increase in peripheral vascular tone. These results identify renalase as what we believe to be a novel amine oxidase that is secreted by the kidney, circulates in blood, and modulates cardiac function and systemic blood pressure. PMID:15841207

Cerebrovasculoprotective Effects of Azilsartan Medoxomil in Diabetes

PubMed Central

Abdelsaid, Mohammed; Coucha, Maha; Ergul, Adviye

2014-01-01

We have shown that Goto-Kakizaki (GK) rats, a lean model of type 2 diabetes, develop significant cerebrovascular remodeling by 18 weeks of age, which is characterized by increased media thickness and matrix deposition. While early glycemic control prevents diabetes-mediated remodeling of the cerebrovasculature, whether the remodeling can be reversed is unknown. Given that angiotensin II Type 1 receptor blockers (ARBs) reverse pathological vascular remodeling and function independent of changes in blood pressure in other vascular beds, we hypothesized that azilsartan medoxomil, a new ARB, is vasculoprotective by preventing and reversing cerebrovascular remodeling in diabetes. Control Wistar and diabetic GK rats (n=6–8/group), were treated with vehicle (water) or azilsartan medoxomil (3 mg/kg/day) from 14 to 18 or 18 to 22 weeks of age before or after vascular remodeling is established, respectively. Blood glucose and blood pressure were monitored and middle cerebral artery structure and function were evaluated using pressurized arteriography. Blood glucose was higher in GK rats compared to Wistar rats. Azilsartan treatment lowered blood glucose in diabetes with no effect on blood pressure. Diabetic animals exhibited lower myogenic tone, increased wall thickness, and cross sectional area compared to controls, which were corrected by azilsartan treatment when started at the onset of diabetes or later after vascular remodeling is established. Azilsartan medoxomil offers preventive and therapeutic vasculoprotection in diabetes-induced cerebrovascular remodeling and myogenic dysfunction and this is independent of blood pressure. PMID:24999268

Baroreflex-Mediated Heart Rate and Vascular Resistance Responses 24 h after Maximal Exercise

DTIC Science & Technology

2003-01-01

of normal physiological function in bedridden patients and astronauts. The implication for failure of CVP and plasma volume to return to baseline... FUNCTION , BLOOD PRES- SURE, CENTRAL VENOUS PRESSURE, PHENYLEPHRINE, NECK PRESSURE, LOWER BODY NEGATIVE PRESSURE, COUNTERMEASURES Increased incidence of...orthostatic hypotension and intol-erance in humans is associated with vascular hypovole-mia and attenuated cardiovascular reflex functions

[TRENDS TO INCREASED BODY FAT AND BLOOD PRESSURE OF UNIVERSITY STUDENTS IN TWO COHORTS (2009-2014)].

PubMed

Contreras-Mellado, Victor; Vilchez-Avaca, Catalina; Gomez-Campos, Rossana; Luarte-Rocha, Cristian; Cossio Bolaños, Marco A

2015-12-01

a) describe changes in body adiposity, b) quantify the increase in blood pressure and c) verify if blood pressure increases according to the categories of body fatness in two cohorts (2009-2014) in university students. two transverse measurements made in 2009 and 2014. The 2009 sample consisted of 309 university students (138 men and 171 women) and 2014 by 319 young people (136 men and 183 women) were compared. Weight, height, body mass index, waist circumference and systolic and diastolic blood pressure were evaluated. males were significantly increased body adiposity (BMI = 1.9 kg/m2 and CC = 6.4 cm), (p < 0.001), while women increased blood pressure (DBP = 5.7 mmHg and SBP = 6.6 mmHg) as a function of body fat in a range of 5 years (p < 0.001). males increased their body fat, while women increased blood pressure. The results suggest the adoption of healthy lifestyles to combat excess weight and the presence of hypertension in young students. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

The influence of central command on baroreflex resetting during exercise

NASA Technical Reports Server (NTRS)

Raven, Peter B.; Fadel, Paul J.; Smith, Scott A.

2002-01-01

The arterial baroreflex functions as a negative feedback system regulating blood pressure around an established operating point. Paradoxically, a parallel increase in heart rate and blood pressure manifests during exercise. Experimental evidence suggests these events are caused, in part, by a rapid resetting of the baroreflex by central command.

Dietary saturated and unsaturated fats as determinants of blood pressure and vascular function.

PubMed

Hall, Wendy L

2009-06-01

The amount and type of dietary fat have long been associated with the risk of CVD. Arterial stiffness and endothelial dysfunction are important risk factors in the aetiology of CHD. A range of methods exists to assess vascular function that may be used in nutritional science, including clinic and ambulatory blood pressure monitoring, pulse wave analysis, pulse wave velocity, flow-mediated dilatation and venous occlusion plethysmography. The present review focuses on the quantity and type of dietary fat and effects on blood pressure, arterial compliance and endothelial function. Concerning fat quantity, the amount of dietary fat consumed habitually appears to have little influence on vascular function independent of fatty acid composition, although single high-fat meals postprandially impair endothelial function compared with low-fat meals. The mechanism is related to increased circulating lipoproteins and NEFA which may induce pro-inflammatory pathways and increase oxidative stress. Regarding the type of fat, cross-sectional data suggest that saturated fat adversely affects vascular function whereas polyunsaturated fat (mainly linoleic acid (18 : 2n-6) and n-3 PUFA) are beneficial. EPA (20 : 5n-3) and DHA (22 : 6n-3) can reduce blood pressure, improve arterial compliance in type 2 diabetics and dyslipidaemics, and augment endothelium-dependent vasodilation. The mechanisms for this vascular protection, and the nature of the separate physiological effects induced by EPA and DHA, are priorities for future research. Since good-quality observational or interventional data on dietary fatty acid composition and vascular function are scarce, no further recommendations can be suggested in addition to current guidelines at the present time.

Gender-specific association of the plasminogen activator inhibitor-1 4G/5G polymorphism with central arterial blood pressure.

PubMed

Björck, Hanna M; Eriksson, Per; Alehagen, Urban; De Basso, Rachel; Ljungberg, Liza U; Persson, Karin; Dahlström, Ulf; Länne, Toste

2011-07-01

The functional plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism has previously been associated with hypertension. In recent years, central blood pressure, rather than brachial has been argued a better measure of cardiovascular damage and clinical outcome. The aim of this study was to investigate the possible influence of the 4G/5G polymorphism on central arterial blood pressure in a cohort of elderly individuals. We studied 410 individuals, 216 men and 194 women, aged 70-88. Central pressures and pulse waveforms were calculated from the radial artery pressure waveform by the use of the SphygmoCor system and a generalized transfer function. Brachial pressure was recorded using oscillometric technique (Dinamap, Critikon, Tampa, FL). PAI-1 antigen was determined in plasma. The results showed that central pressures were higher in women carrying the PAI-1 4G/4G genotype compared to female carriers of the 5G/5G genotype, (P = 0.025, P = 0.002, and P = 0.002 for central systolic-, diastolic-, and mean arterial pressure, respectively). The association remained after adjustment for potentially confounding factors related to hypertension. No association of the PAI-1 genotype with blood pressure was found in men. Multiple regression analysis revealed an association between PAI-1 genotype and plasma PAI-1 levels (P = 0.048). Our findings show a gender-specific association of the PAI-1 4G/5G polymorphism with central arterial blood pressure. The genotype effect was independent of other risk factors related to hypertension, suggesting that impaired fibrinolytic potential may play an important role in the development of central hypertension in women.

Masked Hypertension is Associated With Cognitive Decline in Geriatric Age-Geriatric MASked Hypertension and Cognition (G-MASH-cog) Study.

PubMed

Esme, Mert; Yavuz, Burcu Balam; Yavuz, Bunyamin; Asil, Serkan; Tuna Dogrul, Rana; Sumer, Fatih; Kilic, Mustafa Kemal; Kizilarslanoglu, Muhammet Cemal; Varan, Hacer Dogan; Sagir, Aykut; Balci, Cafer; Halil, Meltem; Cankurtaran, Mustafa

2018-01-16

Masked hypertension is described as high ambulatory blood pressure measurements (ABPM) where office blood pressure measurements are normal. Effect of hypertension on cognitive functions is well known. However, the effect of masked hypertension on cognitive functions is unclear. The aim of this study is to examine the relationship between masked hypertension and cognitive functions. One hundred-two normotensive patients admitted to the Geriatric Medicine outpatient clinic were included. Exclusion criteria were hypertension, dementia, major depression, and usage of antihypertensive medication. All patients underwent ABPM procedures and average daytime blood pressure, mean blood pressure at night and the 24-hour average blood pressure measurements were recorded. Comprehensive geriatric assessment tests and neuropsychological tests were administered. The diagnosis of masked hypertension was based on the definitions in the 2013 guideline of the European Society of Cardiology. Forty-four patients (43%) were diagnosed with masked hypertension. Patients with masked hypertension had significantly lower scores on Mini-Mental State Examination (MMSE) test, Quick Mild Cognitive Impairment Test (QMCI), and Categorical Fluency Test than the normotensive patients (p = .011; p = .046; and p = .004; respectively). Montreal Cognitive Assessment Scale test score was lower in masked hypertension, although this was not statistically significant. This study may indicate that geriatric patients with masked hypertension, compared to normotensive patients have decreased cognitive functions. Masked hypertension should be kept in mind while assessing older adults. When masked hypertension is detected, cognitive assessment is essential to diagnose possible cognitive dysfunction at early stage. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A common hypofunctional genetic variant of GPER is associated with increased blood pressure in women

PubMed Central

Feldman, Ross D; Gros, Robert; Ding, Qingming; Hussain, Yasin; Ban, Matthew R; McIntyre, Adam D; Hegele, Robert A

2014-01-01

Aims Activation of vascular GPER has been linked to vasodepressor effects in animals. However, the significance of GPER regulation on chronic blood pressure control in humans is unknown. Methods To examine this question we determined the functional significance of expression of a common missense single nucleotide variant of GPER, P16L in vascular smooth muscle cells, and its association with blood pressure in humans. Further, to validate the importance of carrying GPER P16L in the development of hypertension we assessed allele frequency in a cohort of hard-to-treat hypertensive patients referred to a tertiary care clinic. Results Expression of the GPER P16L variant (V) vs. wild type (WT) in rat aortic vascular smooth muscle cells, was associated with a significant decrease in G1 (1 μm, a GPER agonist)-mediated ERK phosphorylation (slope of the function of G1-stimulated ERK phosphorylation: GPER content WT: 16.2, 95% CI 9.9, 22.6; V: 5.0, 95% CI 1.0, 9.0; P < 0.005) and apoptosis (slope of the function of G1-stimulated apoptosis: GPER content: WT: 4.4, 95% CI: 3.4, 5.4; V: 2.5, 95% CI 1.6, 2.3 P < 0.005). Normotensive female subjects, but not male subjects, carrying this hypofunctional variant (allele frequency 22%) have increased blood pressure [mean arterial pressure: P16/P16: 80 ± 1 mmHg (n = 204) vs. P16L carriers: 82 ± 1 mmHg (n = 127), 95% CI for difference: 0.6, 4.0 mmHg, P < 0.05], [systolic blood pressure: P16/P16: 105 ± 1 mmHg vs. P16L carriers: 108 ± 1 mmHg, 95% CI for difference:1.0, 5.1 mmHg, P < 0.05], [diastolic blood pressure: P16/P16: 66 ± 0.5 mmHg vs. P16L carriers 68 ± 0.7, 95% CI for difference: 0.2, 3.6 mmHg, P < 0.05]. Further, the P16L allele frequency was almost two-fold higher in female vs. male hypertensive patients (31% vs. 16%, allele ratio 0.5, 95% CI 0.32, 0.76, P < 0.05). Conclusions The common genetic variant, GPER P16L, is hypofunctional and female carriers of this allele have increased blood pressure. There was an increased prevalence in a population of hard-to-treat hypertensive female patients. Cumulatively, these data suggest that in females, impaired GPER function might be associated with increased blood pressure and risk of hypertension. PMID:25039431

A common hypofunctional genetic variant of GPER is associated with increased blood pressure in women.

PubMed

Feldman, Ross D; Gros, Robert; Ding, Qingming; Hussain, Yasin; Ban, Matthew R; McIntyre, Adam D; Hegele, Robert A

2014-12-01

Activation of vascular GPER has been linked to vasodepressor effects in animals. However, the significance of GPER regulation on chronic blood pressure control in humans is unknown. To examine this question we determined the functional significance of expression of a common missense single nucleotide variant of GPER, P16L in vascular smooth muscle cells, and its association with blood pressure in humans. Further, to validate the importance of carrying GPER P16L in the development of hypertension we assessed allele frequency in a cohort of hard-to-treat hypertensive patients referred to a tertiary care clinic. Expression of the GPER P16L variant (V) vs. wild type (WT) in rat aortic vascular smooth muscle cells, was associated with a significant decrease in G1 (1 μm, a GPER agonist)-mediated ERK phosphorylation (slope of the function of G1-stimulated ERK phosphorylation: GPER content WT: 16.2, 95% CI 9.9, 22.6; V: 5.0, 95% CI 1.0, 9.0; P < 0.005) and apoptosis (slope of the function of G1-stimulated apoptosis: GPER content: WT: 4.4, 95% CI: 3.4, 5.4; V: 2.5, 95% CI 1.6, 2.3 P < 0.005). Normotensive female subjects, but not male subjects, carrying this hypofunctional variant (allele frequency 22%) have increased blood pressure [mean arterial pressure: P16/P16: 80 ± 1 mmHg (n = 204) vs. P16L carriers: 82 ± 1 mmHg (n = 127), 95% CI for difference: 0.6, 4.0 mmHg, P < 0.05], [systolic blood pressure: P16/P16: 105 ± 1 mmHg vs. P16L carriers: 108 ± 1 mmHg, 95% CI for difference:1.0, 5.1 mmHg, P < 0.05], [diastolic blood pressure: P16/P16: 66 ± 0.5 mmHg vs. P16L carriers 68 ± 0.7, 95% CI for difference: 0.2, 3.6 mmHg, P < 0.05]. Further, the P16L allele frequency was almost two-fold higher in female vs. male hypertensive patients (31% vs. 16%, allele ratio 0.5, 95% CI 0.32, 0.76, P < 0.05). The common genetic variant, GPER P16L, is hypofunctional and female carriers of this allele have increased blood pressure. There was an increased prevalence in a population of hard-to-treat hypertensive female patients. Cumulatively, these data suggest that in females, impaired GPER function might be associated with increased blood pressure and risk of hypertension. © 2014 The British Pharmacological Society.

Blood pressure monitor with a position sensor for wrist placement to eliminate hydrostatic pressure effect on blood pressure measurement.

PubMed

Sato, Hironori; Koshimizu, Hiroshi; Yamashita, Shingo; Ogura, Toshihiko

2013-01-01

Accurate measurement of blood pressure at wrist requires the heart and wrist to be kept at the same level to avoid the effects of hydrostatic pressure. Although a blood pressure monitor with a position sensor that guides appropriate forearm angle without use of a chair and desk has already been proposed, a similar functioning device for measuring upper arm blood pressure with a chair and desk is needed. In this study, a calculation model was first used to explore design of such a system. The findings were then implemented into design of a new blood pressure monitor. Results of various methods were compared. The calculation model of the wrist level from arthrosis angles and interarticulars lengths was developed and considered using published anthropometric dimensions. It is compared with 33 volunteer persons' experimental results. The calculated difference of level was -4.1 to 7.9 (cm) with a fixed chair and desk. The experimental result was -3.0 to 5.5 (cm) at left wrist and -2.1 to 6.3(cm) at right wrist. The absolute difference level equals ±4.8 (mmHg) of blood pressure readings according to the calculated result. This meets the AAMI requirements for a blood pressure monitor. In the conclusion, the calculation model is able to effectively evaluate the difference between the heart and wrist level. Improving the method for maintaining wrist to heart level will improve wrist blood pressure measurement accuracy when also sitting in the chair at a desk. The leading angle of user's forearm using a position sensor is shown to work for this purpose.

The effects of balneotherapy on acute, process-related, and cumulative peripheral cardiac responses and pulmonary functions in patients with musculoskeletal disorders.

PubMed

Şaş, Senem; Toprak Çelenay, Şeyda; Özer Kaya, Derya

2016-12-20

This study aimed to evaluate the effects of balneotherapy on acute, process-related, and cumulative peripheral cardiac responses and pulmonary functions in patients with musculoskeletal disorders. Ninety-eight patients with musculoskeletal disorders referred to physiotherapy with balneotherapy were recruited. The patients received balneotherapy for 20 min 5 times per week for 2 weeks. Blood pressure and pulse were measured at the 0th, 5th, 10th, 20th, and 30th minutes during the 1st and 10th sessions. All patients were subjected to pulmonary function testing before balneotherapy and after the 10th session. It was found that systolic blood pressure decreased between the 10th and 20th minutes of the 1st session and between the 10th and 20th minutes and the 20th and 30th minutes of the 10th session (P < 0.05). Diastolic blood pressure (DBP) decreased and pulse increased during balneotherapy (P < 0.05). DBP increase and pulse decrease were observed during recovery time (P < 0.05). The blood pressure decreased and the pulse increased after the 1st session and after the 10th session (P < 0.05). Pulmonary function improved after balneotherapy (P < 0.05). Conclusions: Balneotherapy may be effective for improving peripheral cardiopulmonary responses in patients with musculoskeletal disorders.

Epidural Spinal Cord Stimulation of Lumbosacral Networks Modulates Arterial Blood Pressure in Individuals With Spinal Cord Injury-Induced Cardiovascular Deficits.

PubMed

Aslan, Sevda C; Legg Ditterline, Bonnie E; Park, Michael C; Angeli, Claudia A; Rejc, Enrico; Chen, Yangsheng; Ovechkin, Alexander V; Krassioukov, Andrei; Harkema, Susan J

2018-01-01

Disruption of motor and autonomic pathways induced by spinal cord injury (SCI) often leads to persistent low arterial blood pressure and orthostatic intolerance. Spinal cord epidural stimulation (scES) has been shown to enable independent standing and voluntary movement in individuals with clinically motor complete SCI. In this study, we addressed whether scES configured to activate motor lumbosacral networks can also modulate arterial blood pressure by assessing continuous, beat-by-beat blood pressure and lower extremity electromyography during supine and standing in seven individuals with C5-T4 SCI. In three research participants with arterial hypotension, orthostatic intolerance, and low levels of circulating catecholamines (group 1), scES applied while supine and standing resulted in increased arterial blood pressure. In four research participants without evidence of arterial hypotension or orthostatic intolerance and normative circulating catecholamines (group 2), scES did not induce significant increases in arterial blood pressure. During scES, there were no significant differences in electromyographic (EMG) activity between group 1 and group 2. In group 1, during standing assisted by scES, blood pressure was maintained at 119/72 ± 7/14 mmHg (mean ± SD) compared with 70/45 ± 5/7 mmHg without scES. In group 2 there were no arterial blood pressure changes during standing with or without scES. These findings demonstrate that scES configured to facilitate motor function can acutely increase arterial blood pressure in individuals with SCI-induced cardiovascular deficits.

The Role of Hyperglycemia, Insulin Resistance, and Blood Pressure in Diabetes-Associated Differences in Cognitive Performance-The Maastricht Study.

PubMed

Geijselaers, Stefan L C; Sep, Simone J S; Claessens, Danny; Schram, Miranda T; van Boxtel, Martin P J; Henry, Ronald M A; Verhey, Frans R J; Kroon, Abraham A; Dagnelie, Pieter C; Schalkwijk, Casper G; van der Kallen, Carla J H; Biessels, Geert Jan; Stehouwer, Coen D A

2017-11-01

To study to what extent differences in cognitive performance between individuals with different glucose metabolism status are potentially attributable to hyperglycemia, insulin resistance, and blood pressure-related variables. We used cross-sectional data from 2,531 participants from the Maastricht Study (mean age ± SD, 60 ± 8 years; 52% men; n = 666 with type 2 diabetes), all of whom completed a neuropsychological test battery. Hyperglycemia was assessed by a composite index of fasting glucose, postload glucose, glycated hemoglobin (HbA 1c ), and tissue advanced glycation end products; insulin resistance by the HOMA of insulin resistance index; and blood pressure-related variables included 24-h ambulatory pressures, their weighted SDs, and the use of antihypertensive medication. Linear regression analyses were used to estimate mediating effects. After adjustment for age, sex, and education, individuals with type 2 diabetes, compared with those with normal glucose metabolism, performed worse in all cognitive domains (mean differences in composite z scores for memory -0.087, processing speed -0.196, executive function and attention -0.182; P values <0.032), whereas individuals with prediabetes did not. Diabetes-associated differences in processing speed and executive function and attention were largely explained by hyperglycemia (mediating effect 79.6% [bootstrapped 95% CI 36.6; 123.4] and 50.3% [0.6; 101.2], respectively) and, for processing speed, to a lesser extent by blood pressure-related variables (17.7% [5.6; 30.1]), but not by insulin resistance. None of the factors explained the differences in memory function. Our cross-sectional data suggest that early glycemic and blood pressure control, perhaps even in the prediabetic stage, may be promising therapeutic targets for the prevention of diabetes-associated decrements in cognitive performance. © 2017 by the American Diabetes Association.

Normalization of Blood Pressure With Spinal Cord Epidural Stimulation After Severe Spinal Cord Injury

PubMed Central

Harkema, Susan J.; Wang, Siqi; Angeli, Claudia A.; Chen, Yangsheng; Boakye, Maxwell; Ugiliweneza, Beatrice; Hirsch, Glenn A.

2018-01-01

Chronic low blood pressure and orthostatic hypotension remain challenging clinical issues after severe spinal cord injury (SCI), affecting health, rehabilitation, and quality of life. We previously reported that targeted lumbosacral spinal cord epidural stimulation (scES) could promote stand and step functions and restore voluntary movement in patients with chronic motor complete SCI. This study addresses the effects of targeted scES for cardiovascular function (CV-scES) in individuals with severe SCI who suffer from chronic hypotension. We tested the hypothesis that CV-scES can increase resting blood pressure and attenuate chronic hypotension in individuals with chronic cervical SCI. Four research participants with chronic cervical SCI received an implant of a 16-electrode array on the dura (L1–S1 cord segments, T11–L1 vertebrae). Individual-specific CV-scES configurations (anode and cathode electrode selection, voltage, frequency, and pulse width) were identified to maintain systolic blood pressure within targeted normative ranges without skeletal muscle activity of the lower extremities as assessed by electromyography. These individuals completed five 2-h sessions using CV-scES in an upright, seated position during measurement of blood pressure and heart rate. Noninvasive continuous blood pressure was measured from a finger cuff by plethysmograph technique. For each research participant there were statistically significant increases in mean arterial pressure in response to CV-scES that was maintained within normative ranges. This result was reproducible over the five sessions with concomitant decreases or no changes in heart rate using individual-specific CV-scES that was modulated with modest amplitude changes throughout the session. Our study shows that stimulating dorsal lumbosacral spinal cord can effectively and safely activate mechanisms to elevate blood pressures to normal ranges from a chronic hypotensive state in humans with severe SCI with individual-specific CV-scES. PMID:29568266

Effect of kefir and low-dose aspirin on arterial blood pressure measurements and renal apoptosis in unhypertensive rats with 4 weeks salt diet.

PubMed

Kanbak, Güngör; Uzuner, Kubilay; Kuşat Ol, Kevser; Oğlakçı, Ayşegül; Kartkaya, Kazım; Şentürk, Hakan

2014-01-01

Abstract We aim to study the effect of low-dose aspirin and kefir on arterial blood pressure measurements and renal apoptosis in unhypertensive rats with 4 weeks salt diet. Forty adult male Sprague-Dawley rats were divided into five groups: control, high-salt (HS) (8.0% NaCl), HS+aspirin (10 mg/kg), HS+kefir (10.0%w/v), HS+aspirin +kefir. We measured sistolic blood pressure (SBP), mean arterial pressure (MAP), diastolic pressure, pulse pressure in the rats. Cathepsin B, L, DNA fragmentation and caspase-3 activities were determined from rat kidney tissues and rats clearance of creatinine calculated. Although HS diet increased significantly SBP, MAP, diastolic pressure, pulse pressure parameters compared the control values. They were not as high as accepted hypertension levels. When compared to HS groups, kefir groups significantly decrease Cathepsin B and DNA fragmentation levels. Caspase levels were elevated slightly in other groups according to control group. While, we also found that creatinine clearance was higher in HS+kefir and HS+low-dose aspirin than HS group. Thus, using low-dose aspirin had been approximately decreased of renal function damage. Kefir decreased renal function damage playing as Angiotensin-converting enzyme inhibitor. But, low-dose aspirin together with kefir worsened rat renal function damage. Cathepsin B might play role both apoptosis and prorenin-processing enzyme. But not caspase pathway may be involved in the present HS diet induced apoptosis. In conclusion, kefir and low-dose aspirin used independently protect renal function and renal damage induced by HS diet in rats.

The effect of massage on immune function and stress in women with breast cancer--a randomized controlled trial.

PubMed

Billhult, A; Lindholm, C; Gunnarsson, Ronny; Stener-Victorin, E

2009-10-05

To examine the short-term effects of light pressure effleurage on circulating lymphocytes by studying the number and activity of peripheral blood natural killer (NK) cells in patients with breast cancer compared to a control group. Furthermore, the effect of light pressure effleurage on salivary cortisol levels, heart rate and blood pressure was studied. Single centre, prospective, randomized and controlled study. Thirty women, aged 50 to 75 years (mean 61 sd=7.2) with breast cancer undergoing radiation therapy in a hospital in southwestern Sweden were enrolled in the study. They were allocated to either receive massage in the form of a full-body light pressure effleurage treatment, or a control visit where they were given an equal amount of attention. Blood samples, saliva, notation of heart rate and blood pressure were collected before and after massage/control visit. Differences in change over time between groups were analyzed by Student's t-test. Light pressure effleurage massage decreased the deterioration of NK cell activity occurring during radiation therapy. Furthermore it lowered heart rate and systolic blood pressure. No effects were demonstrated on cortisol and diastolic pressure. A single full-body light pressure effleurage massage has a short-term effect on NK cell activity, systolic blood pressure and heart rate in patients with breast cancer. However, the long-term clinical importance of these findings needs to be further investigated.

[System analytical approach of lung function and hemodynamics].

PubMed

Naszlady, Attila; Kiss, Lajos

2009-02-15

The authors critically analyse the traditional views in physiology and complete them with new statements based on computer model simulations of lung function and of hemodynamics. Conclusions are derived for the clinical practice as follows: the four-dimensional function curves are similar in both systems; there is a "waterfall" zone in the pulmonary blood perfusion; the various time constants of pulmonary regions can modify the blood gas values; pulmonary capillary pressure is equal to pulmonary arterial diastole pressure; heart is not a pressure pump, but a flow source; ventricles are loaded by the input impedance of the arterial systems and not by the total vascular (ohmlike) resistance; optimum heart rate in rest depends on the length of the aorta; this law of heart rate, based on the principle of resonance is valid along the mammalian allometric line; tachycardia decreases the input impedance; using positive end expiratory pressure respirators the blood gas of pulmonary artery should be followed; coronary circulation should be assessed in beat per milliliter, the milliliter per minute may be false. These statements are compared to related references.

Hemodynamics

PubMed Central

Secomb, Timothy W.

2016-01-01

A review is presented of the physical principles governing the distribution of blood flow and blood pressure in the vascular system. The main factors involved are the pulsatile driving pressure generated by the heart, the flow characteristics of blood, and the geometric structure and mechanical properties of the vessels. The relationship between driving pressure and flow in a given vessel can be understood by considering the viscous and inertial forces acting on the blood. Depending on the vessel diameter and other physical parameters, a wide variety of flow phenomena can occur. In large arteries, the propagation of the pressure pulse depends on the elastic properties of the artery walls. In the microcirculation, the fact that blood is a suspension of cells strongly influences its flow properties and leads to a non-uniform distribution of hematocrit among microvessels. The forces acting on vessel walls include shear stress resulting from blood flow and circumferential stress resulting from blood pressure. Biological responses to these forces are important in the control of blood flow and the structural remodeling of vessels, and also play a role in major disease processes including hypertension and atherosclerosis. Consideration of hemodynamics is essential for a comprehensive understanding of the functioning of the circulatory system. PMID:27065172

Amino Acids That Centrally Influence Blood Pressure and Regional Blood Flow in Conscious Rats

PubMed Central

Takemoto, Yumi

2012-01-01

Functional roles of amino acids have increasingly become the focus of research. This paper summarizes amino acids that influence cardiovascular system via the brain of conscious rats. This paper firstly describes why amino acids are selected and outlines how the brain regulates blood pressure and regional blood flow. This section includes a concise history of amino acid neurotransmitters in cardiovascular research and summarizes brain areas where chemical stimulations produce blood pressure changes mainly in anesthetized animals. This is followed by comments about findings regarding several newly examined amino acids with intracisternal stimulation in conscious rats that produce changes in blood pressure. The same pressor or depressor response to central amino acid stimulations can be produced by distinct mechanisms at central and peripheral levels, which will be briefly explained. Thereafter, cardiovascular actions of some of amino acids at the mechanism level will be discussed based upon findings of pharmacological and regional blood flow measurements. Several examined amino acids in addition to the established neurotransmitter amino acids appear to differentially activate brain structures to produce changes in blood pressure and regional blood flows. They may have physiological roles in the healthy brain, but pathological roles in the brain with cerebral vascular diseases such as stroke where the blood-brain barrier is broken. PMID:22690328

Cold Stress and the Cold Pressor Test

ERIC Educational Resources Information Center

Silverthorn, Dee U.; Michael, Joel

2013-01-01

Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function. This…

Circadian blood pressure variability in type 1 diabetes subjects and their nondiabetic siblings - influence of erythrocyte electron transfer.

PubMed

Matteucci, Elena; Consani, Cristina; Masoni, Maria Chiara; Giampietro, Ottavio

2010-10-05

Normotensive non-diabetic relatives of type 1 diabetes (T1D) patients have an abnormal blood pressure response to exercise testing that is associated with indices of metabolic syndrome and increased oxidative stress. The primary aim of this study was to investigate the circadian variability of blood pressure and the ambulatory arterial stiffness index (AASI) in healthy siblings of T1D patients vs healthy control subjects who had no first-degree relative with T1D. Secondary aims of the study were to explore the influence of both cardiovascular autonomic function and erythrocyte electron transfer activity as oxidative marker on the ambulatory blood pressure profile. Twenty-four hour ambulatory blood pressure monitoring (ABPM) was undertaken in 25 controls, 20 T1D patients and 20 siblings. In addition to laboratory examination (including homeostasis model assessment of insulin sensitivity) and clinical testing of autonomic function, we measured the rate of oxidant-induced erythrocyte electron transfer to extracellular ferricyanide (RBC vfcy). Systolic blood pressure (SBP) midline-estimating statistic of rhythm and pulse pressure were higher in T1D patients and correlated positively with diabetes duration and RBC vfcy; autonomic dysfunction was associated with diastolic BP ecphasia and increased AASI. Siblings had higher BMI, lower insulin sensitivity, larger SBP amplitude, and higher AASI than controls. Daytime SBP was positively, independently associated with BMI and RBC vfcy. Among non-diabetic people, there was a significant correlation between AASI and fasting plasma glucose. Siblings of T1D patients exhibited a cluster of sub-clinical metabolic abnormalities associated with consensual perturbations in BP variability. Moreover, our findings support, in a clinical setting, the proposed role of transplasma membrane electron transport systems in vascular pathobiology.

Orthostatic Hypotension: A Practical Approach to Investigation and Management.

PubMed

Arnold, Amy C; Raj, Satish R

2017-12-01

The maintenance of blood pressure upon the assumption of upright posture depends on rapid cardiovascular adaptations driven primarily by the autonomic nervous system. Failure of these compensatory mechanisms can result in orthostatic hypotension (OH), defined as sustained reduction in systolic blood pressure > 20 mm Hg or diastolic blood pressure > 10 mm Hg within 3 minutes of standing or > 60° head-up tilt. OH is a common finding, particularly in elderly populations, associated with cardiovascular and cerebrovascular morbidity and mortality. Therefore, it is important to identify OH in the clinical setting. The detection of OH requires blood pressure measurements in the supine and standing positions. A more practical approach in clinics might be measurement of seated and standing blood pressure, but this can produce smaller depressor responses because of reduced gravitational stress. Heart rate responses to standing should be concomitantly measured to assess integrity of baroreflex function. Patients with OH can present with symptoms of cerebral hypoperfusion on standing predisposing to syncope and falls; however, many patients are asymptomatic. When the diagnosis of OH is established, it is important to document potentially deleterious medications and comorbidities and to assess for neurogenic autonomic impairment to establish underlying causes. Treatment should be initiated in a structured and stepwise approach starting with nonpharmacological interventions (eg, lifestyle modifications and physical countermanoeuvres), and adding pharmacological interventions as needed in patients with severe OH (eg, midodrine, droxidopa, fludrocortisone). The treatment goal in OH should be to improve symptoms and functional status, and not to target arbitrary blood pressure values. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Respiratory sinus arrhythmia stabilizes mean arterial blood pressure at high-frequency interval in healthy humans.

PubMed

Elstad, Maja; Walløe, Lars; Holme, Nathalie L A; Maes, Elke; Thoresen, Marianne

2015-03-01

Arterial blood pressure variations are an independent risk factor for end organ failure. Respiratory sinus arrhythmia (RSA) is a sign of a healthy cardiovascular system. However, whether RSA counteracts arterial blood pressure variations during the respiratory cycle remains controversial. We restricted normal RSA with non-invasive intermittent positive pressure ventilation (IPPV) to test the hypothesis that RSA normally functions to stabilize mean arterial blood pressure. Ten young volunteers were investigated during metronome-paced breathing and IPPV. Heart rate (ECG), mean arterial blood pressure and left stroke volume (finger arterial pressure curve) and right stroke volume (pulsed ultrasound Doppler) were recorded, while systemic and pulmonary blood flow were calculated beat-by-beat. Respiratory variations (high-frequency power, 0.15-0.40 Hz) in cardiovascular variables were estimated by spectral analysis. Phase angles and correlation were calculated by cross-spectral analysis. The magnitude of RSA was reduced from 4.9 bpm(2) (95% CI 3.0, 6.2) during metronome breathing to 2.8 bpm(2) (95% CI 1.1, 5.0) during IPPV (p = 0.03). Variations in mean arterial blood pressure were greater (2.3 mmHg(2) (95% CI 1.4, 3.9) during IPPV than during metronome breathing (1.0 mmHg(2) [95% CI 0.7, 1.3]) (p = 0.014). Respiratory variations in right and left stroke volumes were inversely related in the respiratory cycle during both metronome breathing and IPPV. RSA magnitude is lower and mean arterial blood pressure variability is greater during IPPV than during metronome breathing. We conclude that in healthy humans, RSA stabilizes mean arterial blood pressure at respiratory frequency.

Relationship between cerebral blood flow and blood pressure in long-term heart transplant recipients.

PubMed

Smirl, Jonathan D; Haykowsky, Mark J; Nelson, Michael D; Tzeng, Yu-Chieh; Marsden, Katelyn R; Jones, Helen; Ainslie, Philip N

2014-12-01

Heart transplant recipients are at an increased risk for cerebral hemorrhage and ischemic stroke; yet, the exact mechanism for this derangement remains unclear. We hypothesized that alterations in cerebrovascular regulation is principally involved. To test this hypothesis, we studied cerebral pressure-flow dynamics in 8 clinically stable male heart transplant recipients (62±8 years of age and 9±7 years post transplant, mean±SD), 9 male age-matched controls (63±8 years), and 10 male donor controls (27±5 years). To increase blood pressure variability and improve assessment of the pressure-flow dynamics, subjects performed squat-stand maneuvers at 0.05 and 0.10 Hz. Beat-to-beat blood pressure, middle cerebral artery velocity, and end-tidal carbon dioxide were continuously measured during 5 minutes of seated rest and throughout the squat-stand maneuvers. Cardiac baroreceptor sensitivity gain and cerebral pressure-flow responses were assessed with linear transfer function analysis. Heart transplant recipients had reductions in R-R interval power and baroreceptor sensitivity low frequency gain (P<0.01) compared with both control groups; however, these changes were unrelated to transfer function metrics. Thus, in contrast to our hypothesis, the increased risk of cerebrovascular complication after heart transplantation does not seem to be related to alterations in cerebral pressure-flow dynamics. Future research is, therefore, warranted. © 2014 American Heart Association, Inc.

A postscript to Circulation of the blood: men and ideas.

PubMed

Riley, R L

1982-10-01

Since 1964, when Fishman and Richards published Circulation of the Blood: Men and Ideas, Guyton's model of the circulation, in which mean circulatory pressure serves as the upstream pressure for venous return, has been extended, and the concept of vascular smooth muscle tone acting like the pressure surrounding a Starling resistor has been postulated. According to this scheme, the positive zero flow intercepts of rapidly determined arterial pressure-flow curves are the effective downstream pressures for arterial flow to different tissues. The arterioles, like Starling resistors, determine the downstream pressures and are followed by abrupt pressure drops, or "waterfalls." Capillary pressures are closely linked to those of the venules into which they flow. Capillary-venular pressures are the upstream pressures for venous return. In exercising muscles, reduced arteriolar tone lowers arteriolar pressure and increases arterial flow. This, in turn, raises capillary-venular pressure and increases venous flow. The arteriolar-capillary waterfall is decreased or eliminated. Total blood flow is increased by diversion of blood from tissues with slow venous drainage to muscles with fast venous drainage (low resistance X compliance). The heart pumps away the increased venous return by shifting to a new ventricular function curve.

Structural, functional and blood perfusion changes in the rat retina associated with elevated intraocular pressure, measured simultaneously with a combined OCT+ERG system

PubMed Central

Tan, Bingyao; MacLellan, Benjamin; Mason, Erik

2018-01-01

Acute elevation of intraocular pressure (IOP) to ischemic and non-ischemic levels can cause temporary or permanent changes in the retinal morphology, function and blood flow/blood perfusion. Previously, such changes in the retina were assessed separately with different methods in clinical studies and animal models. In this study, we used a combined OCT+ ERG system in combination with Doppler OCT and OCT angiography (OCTA) imaging protocols, in order to evaluate simultaneously and correlate changes in the retinal morphology, the retinal functional response to visual stimulation, and the retinal blood flow/blood perfusion, associated with IOP elevation to ischemic and non-ischemic levels in rats. Results from this study suggest that the inner retina responds faster to IOP elevation to levels greater than 30 mmHg with significant reduction of the total retinal blood flow (TRBF), decrease of the capillaries’ perfusion and reduction of the ON bipolar cells contribution to the ERG traces. Furthermore, this study showed that ischemic levels of IOP elevation cause an additional significant decrease in the ERG photoreceptor response in the posterior retina. Thirty minutes after IOP normalization, retinal morphology, blood flow and blood perfusion recovered to baseline values, while retinal function did not recover completely. PMID:29509807

Stomach distension increases efferent muscle sympathetic nerve activity and blood pressure in healthy humans.

PubMed

Rossi, P; Andriesse, G I; Oey, P L; Wieneke, G H; Roelofs, J M; Akkermans, L M

1998-12-11

Although the enteric nervous system is usually described as a separate and independent entity, animal studies show that gastric distension causes a reflex increase in arterial pressure and a sympathetically mediated increase in heart rate and peripheral vascular resistance. To assess the influence of gastric distension on sympathetic outflow and blood pressure, we recorded muscle sympathetic nerve activity (MSNA) from the peroneal nerve by microneurography in eight healthy volunteers. The stomach was distended by means of a barostat, using a single staircase protocol by which pressure was increased by 2 mmHg every 3 min. Gastric sensory function was assessed at each distension step by using a visual analog scale (VAS) for sensations of fullness, nausea and pain. For comparison, we also performed a cold pressor test. The MSNA increased on barostat-induced gastric distension with an almost concomitant elevation of blood pressure. The increase in both was proportional to the intragastric pressure and both decreased towards initial values after the end of distension. Heart rate increased inconsistently and only at higher distension pressures that were associated with high VAS scores. The opposite was found for the cold pressor test. The results of this study confirm the existence of a functional relationship between gastrointestinal distension and cardiovascular function. Decrease in this gastrovascular response may play a role in postprandial hypotension in the elderly, since the MSNA responses to simulated microgravity decrease with age.

Effects of carprofen on renal function and results of serum biochemical and hematologic analyses in anesthetized dogs that had low blood pressure during anesthesia.

PubMed

Boström, Ingrid M; Nyman, Görel C; Lord, Peter E; Häggström, Jens; Jones, Bernt E V; Bohlin, Henrik P

2002-05-01

To investigate effects of IV administered carprofen on indices of renal function and results of serum biochemical and hematologic analyses in dogs anesthetized with acepromazine-thiopentone-isoflurane that had low blood pressure during anesthesia. 6 healthy Beagles. A randomized crossover study was conducted, using the following treatments: saline (0.9% NaCl solution)-saline, saline-carprofen, and carprofen-saline. Saline (0.08 ml/kg) and carprofen (4 mg/kg) were administered IV. The first treatment was administered 30 minutes before induction of anesthesia and immediately before administration of acepromazine (0.1 mg/kg, IM). Anesthesia was induced with thiopentone (25 mg/ml, IV) and maintained with inspired isoflurane (2% in oxygen). The second treatment was administered 30 minutes after onset of inhalation anesthesia. Blood gases, circulation, and ventilation were monitored. Renal function was assessed by glomerular filtration rate (GFR), using scintigraphy, serum biochemical analyses, and urinalysis. Hematologic analysis was performed. Statistical analysis was conducted, using ANOVA or Friedman ANOVA. Values did not differ significantly among the 3 treatments. For all treatments, sedation and anesthesia caused changes in results of serum biochemical and hematologic analyses, a decrease in mean arterial blood pressure to 65 mm Hg, an increase of 115 pmol/L in angiotensin II concentration, and an increase of 100 seconds in time required to reach maximum activity counts during scintigraphy. Carprofen administered IV before or during anesthesia did not cause detectable significant adverse effects on renal function or results of serum biochemical and hematologic analyses in healthy Beagles with low blood pressure during anesthesia.

D-camphor-crataegus berry extract combination increases blood pressure and cognitive functioning in the elderly - a randomized, placebo controlled double blind study.

PubMed

Werner, Natalie S; Duschek, Stefan; Schandry, Rainer

2009-12-01

The present study investigated whether the D-camphor-crataegus berry extract combination Korodin elevates blood pressure and enhances cognitive performance in the elderly population. Eighty women aged between 50 and 80 years were examined based on a randomized, placebo controlled double blind design. Blood pressure was measured sphygmomanometrically and through continuous noninvasive recording. Cognitive performance was assessed by means of two tests measuring general information processing capacity and visuomotor speed. The administration of the drug led to a short term increase in blood pressure as well as in cognitive performance as compared to placebo. Potential physiological mechanisms of action mediating this effect, including hemodynamic alterations, sympathetic stimulation as well as improvement of cerebral metabolism are discussed.

Absence of arterial baroreflex modulation of skin sympathetic activity and sweat rate during whole-body heating in humans

NASA Technical Reports Server (NTRS)

Wilson, T. E.; Cui, J.; Crandall, C. G.

2001-01-01

1. Prior findings suggest that baroreflexes are capable of modulating skin blood flow, but the effects of baroreceptor loading/unloading on sweating are less clear. Therefore, this project tested the hypothesis that pharmacologically induced alterations in arterial blood pressure in heated humans would lead to baroreflex-mediated changes in both skin sympathetic nerve activity (SSNA) and sweat rate. 2. In seven subjects mean arterial blood pressure was lowered (approximately 8 mmHg) and then raised (approximately 13 mmHg) by bolus injections of sodium nitroprusside and phenylephrine, respectively. Moreover, in a separate protocol, arterial blood pressure was reduced via steady-state administration of sodium nitroprusside. In both normothermia and heat-stress conditions the following responses were monitored: sublingual and mean skin temperatures, heart rate, beat-by-beat blood pressure, skin blood flow (laser-Doppler flowmetry), local sweat rate and SSNA (microneurography from peroneal nerve). 3. Whole-body heating increased skin and sublingual temperatures, heart rate, cutaneous blood flow, sweat rate and SSNA, but did not change arterial blood pressure. Heart rate was significantly elevated (from 74 +/- 3 to 92 +/- 4 beats x min(-1); P < 0.001) during bolus sodium nitroprusside-induced reductions in blood pressure, and significantly reduced (from 92 +/- 4 to 68 +/- 4 beats x min(-1); P < 0.001) during bolus phenylephrine-induced elevations in blood pressure, thereby demonstrating normal baroreflex function in these subjects. 4. Neither SSNA nor sweat rate was altered by rapid (bolus infusion) or sustained (steady-state infusion) changes in blood pressure regardless of the thermal condition. 5. These data suggest that SSNA and sweat rate are not modulated by arterial baroreflexes in normothermic or moderately heated individuals.

Effects of cilnidipine, a novel dihydropyridine calcium antagonist, on autonomic function, ambulatory blood pressure and heart rate in patients with essential hypertension.

PubMed

Minami, J; Kawano, Y; Makino, Y; Matsuoka, H; Takishita, S

2000-12-01

The aim of the present study was to evaluate the effects of cilnidipine, a novel dihydropyridine calcium antagonist, on autonomic function, ambulatory blood pressure and heart rate in patients with essential hypertension. Ten inpatients with mild to moderate essential hypertension (four men and six women; age: 44-64 years) underwent a drug-free period for 7 days and a treatment period with cilnidipine 10 mg orally for another 7 days, in a randomized crossover study. On the sixth day of each period, they underwent autonomic function tests including a mental arithmetic test, a cold pressor test and a Valsalva manoeuvre. After these tests, 24 h ambulatory blood pressure, heart rate, and the electrocardiogram R-R intervals were monitored every 30 min. A power spectral analysis of R-R intervals was performed to obtain the low-and high-frequency components. Cilnidipine significantly decreased the 24 h blood pressure by 6.5 +/- 1.7 mm Hg systolic (mean +/- s.e.mean; P < 0.01) and 5.0 +/- 1.1 mmHg diastolic (P < 0.01), whereas cilnidipine did not change heart rate or any indices of power spectral components. During the cold pressor test, the maximum change in systolic blood pressure and percentage changes in both systolic and diastolic blood pressures were significantly lower during the treatment period with cilnidipine than during the drug-free period. The baroreflex sensitivity measured from the overshoot phase of the Valsalva manoeuvre did not differ significantly between the two periods. Cilnidipine is effective as a once-daily antihypertensive agent and causes little influence on heart rate and the autonomic nervous system in patients with mild to moderate essential hypertension. Moreover, it is suggested that cilnidipine has an additional clinical benefit in the inhibition of the pressor response induced by acute cold stress.

Elevated blood pressure in preterm-born offspring associates with a distinct antiangiogenic state and microvascular abnormalities in adult life.

PubMed

Lewandowski, Adam J; Davis, Esther F; Yu, Grace; Digby, Janet E; Boardman, Henry; Whitworth, Polly; Singhal, Atul; Lucas, Alan; McCormick, Kenny; Shore, Angela C; Leeson, Paul

2015-03-01

Preterm-born individuals have elevated blood pressure. We tested the hypothesis that this associates with an enhanced antiangiogenic circulating profile and that this association is mediated by variations in capillary density. We studied 204 adults aged 25 years (range, 20-30 years), of which 102 had been followed up prospectively since very preterm birth (mean gestational age, 30.3±2.5 weeks) and 102 were born term to uncomplicated pregnancies. A panel of circulating biomarkers, including soluble endoglin and soluble fms-like tyrosine kinase-1, were compared between groups and related to perinatal history and adult cardiovascular risk. Associations with cardiovascular phenotype were studied in 90 individuals who had undergone detailed assessment of microvascular, macrovascular, and cardiac structure and function. Preterm-born individuals had elevations in soluble endoglin (5.64±1.03 versus 4.06±0.85 ng/mL; P<0.001) and soluble fms-like tyrosine kinase-1 (88.1±19.0 versus 73.0±15.3 pg/mL; P<0.001) compared with term-born individuals, proportional to elevations in resting and ambulatory blood pressure, as well as degree of prematurity (P<0.05). Maternal hypertensive pregnancy disorder was associated with additional increases in soluble fms-like tyrosine kinase-1 (P=0.002). Other circulating biomarkers, including those of inflammation and endothelial activation, were not related to blood pressure. There was a specific graded association between soluble endoglin and degree of functional and structural capillary rarefaction (P=0.002 and P<0.001), and in multivariable analysis, there were capillary density-mediated associations between soluble endoglin and blood pressure. Preterm-born individuals exhibit an enhanced antiangiogenic state in adult life that is specifically related to elevations in blood pressure. The association seems to be mediated through capillary rarefaction and is independent of other cardiovascular structural and functional differences in the offspring. © 2014 American Heart Association, Inc.

Cerebrovasculoprotective effects of azilsartan medoxomil in diabetes.

PubMed

Abdelsaid, Mohammed; Coucha, Maha; Ergul, Adviye

2014-11-01

We have shown that Goto-Kakizaki (GK) rats, a lean model of type 2 diabetes, develop significant cerebrovascular remodeling by the age of 18 weeks, which is characterized by increased media thickness and matrix deposition. Although early glycemic control prevents diabetes-mediated remodeling of the cerebrovasculature, whether the remodeling can be reversed is unknown. Given that angiotensin II type 1 receptor blockers reverse pathologic vascular remodeling and function independent of changes in blood pressure in other vascular beds, we hypothesized that azilsartan medoxomil, a new angiotensin II type 1 receptor blocker, is vasculoprotective by preventing and reversing cerebrovascular remodeling in diabetes. Control Wistar and diabetic GK rats (n = 6-8 per group) were treated with vehicle (water) or azilsartan medoxomil (3 mg/kg/d) from the age of 14 to 18 or 18 to 22 weeks before or after vascular remodeling is established, respectively. Blood glucose and blood pressure were monitored and middle cerebral artery structure and function were evaluated using pressurized arteriography. Blood glucose was higher in GK rats compared with Wistar rats. Azilsartan treatment lowered blood glucose in diabetic animals with no effect on blood pressure. Diabetic animals exhibited lower myogenic tone, increased wall thickness, and cross-sectional area compared with control group animals, which were corrected by azilsartan treatment when started at the onset of diabetes or later after vascular remodeling is established. Azilsartan medoxomil offers preventive and therapeutic vasculoprotection in diabetes-induced cerebrovascular remodeling and myogenic dysfunction and this is independent of blood pressure. Published by Elsevier Inc.

Oral supplementation with 25(OH)D3 versus vitamin D3: effects on 25(OH)D levels, lower extremity function, blood pressure, and markers of innate immunity

USDA-ARS?s Scientific Manuscript database

To test the effect of 25(OH)D3 (HyD) compared to vitamin D3 on serum 25-hydroxyvitamin D levels (25(OH)D), lower extremity function, blood pressure, and markers of innate immunity. Twenty healthy postmenopausal women with an average 25(OH)D level of 13.23.9 ng/mL (meanSD) and a mean age of 61.57.2 y...

Energetic Interrelationship between Spontaneous Low-Frequency Fluctuations in Regional Cerebral Blood Volume, Arterial Blood Pressure, Heart Rate, and Respiratory Rhythm

NASA Astrophysics Data System (ADS)

Katura, Takusige; Yagyu, Akihiko; Obata, Akiko; Yamazaki, Kyoko; Maki, Atsushi; Abe, Masanori; Tanaka, Naoki

2007-07-01

Strong spontaneous fluctuations around 0.1 and 0.3 Hz have been observed in blood-related brain-function measurements such as functional magnetic resonance imaging and optical topography (or functional near-infrared spectroscopy). These fluctuations seem to reflect the interaction between the cerebral circulation system and the systemic circulation system. We took an energetic viewpoint in our analysis of the interrelationships between fluctuations in cerebral blood volume (CBV), mean arterial blood pressure (MAP), heart rate (HR), and respiratory rhythm based on multivariate autoregressive modeling. This approach involves evaluating the contribution of each fluctuation or rhythm to specific ones by performing multivariate spectral analysis. The results we obtained show MAP and HR can account slightly for the fluctuation around 0.1 Hz in CBV, while the fluctuation around 0.3 Hz is derived mainly from the respiratory rhythm. During our presentation, we will report on the effects of posture on the interrelationship between the fluctuations and the respiratory rhythm.

Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

PubMed Central

Drong, Alexander W; Abbott, James; Wahl, Simone; Tan, Sian-Tsung; Scott, William R; Campanella, Gianluca; Chadeau-Hyam, Marc; Afzal, Uzma; Ahluwalia, Tarunveer S; Bonder, Marc Jan; Chen, Peng; Dehghan, Abbas; Edwards, Todd L; Esko, Tõnu; Go, Min Jin; Harris, Sarah E; Hartiala, Jaana; Kasela, Silva; Kasturiratne, Anuradhani; Khor, Chiea-Chuen; Kleber, Marcus E; Li, Huaixing; Yu Mok, Zuan; Nakatochi, Masahiro; Sapari, Nur Sabrina; Saxena, Richa; Stewart, Alexandre F R; Stolk, Lisette; Tabara, Yasuharu; Teh, Ai Ling; Wu, Ying; Wu, Jer-Yuarn; Zhang, Yi; Aits, Imke; Da Silva Couto Alves, Alexessander; Das, Shikta; Dorajoo, Rajkumar; Hopewell, Jemma C; Kim, Yun Kyoung; Koivula, Robert W; Luan, Jian’an; Lyytikäinen, Leo-Pekka; Nguyen, Quang N; Pereira, Mark A; Postmus, Iris; Raitakari, Olli T; Bryan, Molly Scannell; Scott, Robert A; Sorice, Rossella; Tragante, Vinicius; Traglia, Michela; White, Jon; Yamamoto, Ken; Zhang, Yonghong; Adair, Linda S; Ahmed, Alauddin; Akiyama, Koichi; Asif, Rasheed; Aung, Tin; Barroso, Inês; Bjonnes, Andrew; Braun, Timothy R; Cai, Hui; Chang, Li-Ching; Chen, Chien-Hsiun; Cheng, Ching-Yu; Chong, Yap-Seng; Collins, Rory; Courtney, Regina; Davies, Gail; Delgado, Graciela; Do, Loi D; Doevendans, Pieter A; Gansevoort, Ron T; Gao, Yu-Tang; Grammer, Tanja B; Grarup, Niels; Grewal, Jagvir; Gu, Dongfeng; Wander, Gurpreet S; Hartikainen, Anna-Liisa; Hazen, Stanley L; He, Jing; Heng, Chew-Kiat; Hixson, James E; Hofman, Albert; Hsu, Chris; Huang, Wei; Husemoen, Lise L N; Hwang, Joo-Yeon; Ichihara, Sahoko; Igase, Michiya; Isono, Masato; Justesen, Johanne M; Katsuya, Tomohiro; Kibriya, Muhammad G; Kim, Young Jin; Kishimoto, Miyako; Koh, Woon-Puay; Kohara, Katsuhiko; Kumari, Meena; Kwek, Kenneth; Lee, Nanette R; Lee, Jeannette; Liao, Jiemin; Lieb, Wolfgang; Liewald, David C M; Matsubara, Tatsuaki; Matsushita, Yumi; Meitinger, Thomas; Mihailov, Evelin; Milani, Lili; Mills, Rebecca; Mononen, Nina; Müller-Nurasyid, Martina; Nabika, Toru; Nakashima, Eitaro; Ng, Hong Kiat; Nikus, Kjell; Nutile, Teresa; Ohkubo, Takayoshi; Ohnaka, Keizo; Parish, Sarah; Paternoster, Lavinia; Peng, Hao; Peters, Annette; Pham, Son T; Pinidiyapathirage, Mohitha J; Rahman, Mahfuzar; Rakugi, Hiromi; Rolandsson, Olov; Ann Rozario, Michelle; Ruggiero, Daniela; Sala, Cinzia F; Sarju, Ralhan; Shimokawa, Kazuro; Snieder, Harold; Sparsø, Thomas; Spiering, Wilko; Starr, John M; Stott, David J; Stram, Daniel O; Sugiyama, Takao; Szymczak, Silke; Tang, W H Wilson; Tong, Lin; Trompet, Stella; Turjanmaa, Väinö; Ueshima, Hirotsugu; Uitterlinden, André G; Umemura, Satoshi; Vaarasmaki, Marja; van Dam, Rob M; van Gilst, Wiek H; van Veldhuisen, Dirk J; Viikari, Jorma S; Waldenberger, Melanie; Wang, Yiqin; Wang, Aili; Wilson, Rory; Wong, Tien-Yin; Xiang, Yong-Bing; Yamaguchi, Shuhei; Ye, Xingwang; Young, Robin D; Young, Terri L; Yuan, Jian-Min; Zhou, Xueya; Asselbergs, Folkert W; Ciullo, Marina; Clarke, Robert; Deloukas, Panos; Franke, Andre; Franks, Paul W; Franks, Steve; Friedlander, Yechiel; Gross, Myron D; Guo, Zhirong; Hansen, Torben; Jarvelin, Marjo-Riitta; Jørgensen, Torben; Jukema, J Wouter; kähönen, Mika; Kajio, Hiroshi; Kivimaki, Mika; Lee, Jong-Young; Lehtimäki, Terho; Linneberg, Allan; Miki, Tetsuro; Pedersen, Oluf; Samani, Nilesh J; Sørensen, Thorkild I A; Takayanagi, Ryoichi; Toniolo, Daniela; Ahsan, Habibul; Allayee, Hooman; Chen, Yuan-Tsong; Danesh, John; Deary, Ian J; Franco, Oscar H; Franke, Lude; Heijman, Bastiaan T; Holbrook, Joanna D; Isaacs, Aaron; Kim, Bong-Jo; Lin, Xu; Liu, Jianjun; März, Winfried; Metspalu, Andres; Mohlke, Karen L; Sanghera, Dharambir K; Shu, Xiao-Ou; van Meurs, Joyce B J; Vithana, Eranga; Wickremasinghe, Ananda R; Wijmenga, Cisca; Wolffenbuttel, Bruce H W; Yokota, Mitsuhiro; Zheng, Wei; Zhu, Dingliang; Vineis, Paolo; Kyrtopoulos, Soterios A; Kleinjans, Jos C S; McCarthy, Mark I; Soong, Richie; Gieger, Christian; Scott, James

2016-01-01

We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10−11 to 5.0 × 10−21). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10−6). Our results provide new evidence for the role of DNA methylation in blood pressure regulation. PMID:26390057

Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation.

PubMed

Kato, Norihiro; Loh, Marie; Takeuchi, Fumihiko; Verweij, Niek; Wang, Xu; Zhang, Weihua; Kelly, Tanika N; Saleheen, Danish; Lehne, Benjamin; Leach, Irene Mateo; Drong, Alexander W; Abbott, James; Wahl, Simone; Tan, Sian-Tsung; Scott, William R; Campanella, Gianluca; Chadeau-Hyam, Marc; Afzal, Uzma; Ahluwalia, Tarunveer S; Bonder, Marc Jan; Chen, Peng; Dehghan, Abbas; Edwards, Todd L; Esko, Tõnu; Go, Min Jin; Harris, Sarah E; Hartiala, Jaana; Kasela, Silva; Kasturiratne, Anuradhani; Khor, Chiea-Chuen; Kleber, Marcus E; Li, Huaixing; Yu Mok, Zuan; Nakatochi, Masahiro; Sapari, Nur Sabrina; Saxena, Richa; Stewart, Alexandre F R; Stolk, Lisette; Tabara, Yasuharu; Teh, Ai Ling; Wu, Ying; Wu, Jer-Yuarn; Zhang, Yi; Aits, Imke; Da Silva Couto Alves, Alexessander; Das, Shikta; Dorajoo, Rajkumar; Hopewell, Jemma C; Kim, Yun Kyoung; Koivula, Robert W; Luan, Jian'an; Lyytikäinen, Leo-Pekka; Nguyen, Quang N; Pereira, Mark A; Postmus, Iris; Raitakari, Olli T; Bryan, Molly Scannell; Scott, Robert A; Sorice, Rossella; Tragante, Vinicius; Traglia, Michela; White, Jon; Yamamoto, Ken; Zhang, Yonghong; Adair, Linda S; Ahmed, Alauddin; Akiyama, Koichi; Asif, Rasheed; Aung, Tin; Barroso, Inês; Bjonnes, Andrew; Braun, Timothy R; Cai, Hui; Chang, Li-Ching; Chen, Chien-Hsiun; Cheng, Ching-Yu; Chong, Yap-Seng; Collins, Rory; Courtney, Regina; Davies, Gail; Delgado, Graciela; Do, Loi D; Doevendans, Pieter A; Gansevoort, Ron T; Gao, Yu-Tang; Grammer, Tanja B; Grarup, Niels; Grewal, Jagvir; Gu, Dongfeng; Wander, Gurpreet S; Hartikainen, Anna-Liisa; Hazen, Stanley L; He, Jing; Heng, Chew-Kiat; Hixson, James E; Hofman, Albert; Hsu, Chris; Huang, Wei; Husemoen, Lise L N; Hwang, Joo-Yeon; Ichihara, Sahoko; Igase, Michiya; Isono, Masato; Justesen, Johanne M; Katsuya, Tomohiro; Kibriya, Muhammad G; Kim, Young Jin; Kishimoto, Miyako; Koh, Woon-Puay; Kohara, Katsuhiko; Kumari, Meena; Kwek, Kenneth; Lee, Nanette R; Lee, Jeannette; Liao, Jiemin; Lieb, Wolfgang; Liewald, David C M; Matsubara, Tatsuaki; Matsushita, Yumi; Meitinger, Thomas; Mihailov, Evelin; Milani, Lili; Mills, Rebecca; Mononen, Nina; Müller-Nurasyid, Martina; Nabika, Toru; Nakashima, Eitaro; Ng, Hong Kiat; Nikus, Kjell; Nutile, Teresa; Ohkubo, Takayoshi; Ohnaka, Keizo; Parish, Sarah; Paternoster, Lavinia; Peng, Hao; Peters, Annette; Pham, Son T; Pinidiyapathirage, Mohitha J; Rahman, Mahfuzar; Rakugi, Hiromi; Rolandsson, Olov; Ann Rozario, Michelle; Ruggiero, Daniela; Sala, Cinzia F; Sarju, Ralhan; Shimokawa, Kazuro; Snieder, Harold; Sparsø, Thomas; Spiering, Wilko; Starr, John M; Stott, David J; Stram, Daniel O; Sugiyama, Takao; Szymczak, Silke; Tang, W H Wilson; Tong, Lin; Trompet, Stella; Turjanmaa, Väinö; Ueshima, Hirotsugu; Uitterlinden, André G; Umemura, Satoshi; Vaarasmaki, Marja; van Dam, Rob M; van Gilst, Wiek H; van Veldhuisen, Dirk J; Viikari, Jorma S; Waldenberger, Melanie; Wang, Yiqin; Wang, Aili; Wilson, Rory; Wong, Tien-Yin; Xiang, Yong-Bing; Yamaguchi, Shuhei; Ye, Xingwang; Young, Robin D; Young, Terri L; Yuan, Jian-Min; Zhou, Xueya; Asselbergs, Folkert W; Ciullo, Marina; Clarke, Robert; Deloukas, Panos; Franke, Andre; Franks, Paul W; Franks, Steve; Friedlander, Yechiel; Gross, Myron D; Guo, Zhirong; Hansen, Torben; Jarvelin, Marjo-Riitta; Jørgensen, Torben; Jukema, J Wouter; Kähönen, Mika; Kajio, Hiroshi; Kivimaki, Mika; Lee, Jong-Young; Lehtimäki, Terho; Linneberg, Allan; Miki, Tetsuro; Pedersen, Oluf; Samani, Nilesh J; Sørensen, Thorkild I A; Takayanagi, Ryoichi; Toniolo, Daniela; Ahsan, Habibul; Allayee, Hooman; Chen, Yuan-Tsong; Danesh, John; Deary, Ian J; Franco, Oscar H; Franke, Lude; Heijman, Bastiaan T; Holbrook, Joanna D; Isaacs, Aaron; Kim, Bong-Jo; Lin, Xu; Liu, Jianjun; März, Winfried; Metspalu, Andres; Mohlke, Karen L; Sanghera, Dharambir K; Shu, Xiao-Ou; van Meurs, Joyce B J; Vithana, Eranga; Wickremasinghe, Ananda R; Wijmenga, Cisca; Wolffenbuttel, Bruce H W; Yokota, Mitsuhiro; Zheng, Wei; Zhu, Dingliang; Vineis, Paolo; Kyrtopoulos, Soterios A; Kleinjans, Jos C S; McCarthy, Mark I; Soong, Richie; Gieger, Christian; Scott, James; Teo, Yik-Ying; He, Jiang; Elliott, Paul; Tai, E Shyong; van der Harst, Pim; Kooner, Jaspal S; Chambers, John C

2015-11-01

We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10(-11) to 5.0 × 10(-21)). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10(-6)). Our results provide new evidence for the role of DNA methylation in blood pressure regulation.

Renal intercalated cells and blood pressure regulation.

PubMed

Wall, Susan M

2017-12-01

Type B and non-A, non-B intercalated cells are found within the connecting tubule and the cortical collecting duct. Of these cell types, type B intercalated cells are known to mediate Cl - absorption and HCO 3 - secretion largely through pendrin-dependent Cl - /HCO 3 - exchange. This exchange is stimulated by angiotensin II administration and is also stimulated in models of metabolic alkalosis, for instance after aldosterone or NaHCO 3 administration. In some rodent models, pendrin-mediated HCO 3 - secretion modulates acid-base balance. However, the role of pendrin in blood pressure regulation is likely of more physiological or clinical significance. Pendrin regulates blood pressure not only by mediating aldosterone-sensitive Cl - absorption, but also by modulating the aldosterone response for epithelial Na + channel (ENaC)-mediated Na + absorption. Pendrin regulates ENaC through changes in open channel of probability, channel surface density, and channels subunit total protein abundance. Thus, aldosterone stimulates ENaC activity through both direct and indirect effects, the latter occurring through its stimulation of pendrin expression and function. Therefore, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contributory role of pendrin in distal nephron function and blood pressure.

Arterial pressure transfer characteristics: effects of travel time.

PubMed

Westerhof, Berend E; Guelen, Ilja; Stok, Wim J; Wesseling, Karel H; Spaan, Jos A E; Westerhof, Nico; Bos, Willem Jan; Stergiopulos, Nikos

2007-02-01

We investigated the quantitative contribution of all local conduit arterial, blood, and distal load properties to the pressure transfer function from brachial artery to aorta. The model was based on anatomical data, Young's modulus, wall viscosity, blood viscosity, and blood density. A three-element windkessel represented the distal arterial tree. Sensitivity analysis was performed in terms of frequency and magnitude of the peak of the transfer function and in terms of systolic, diastolic, and pulse pressure in the aorta. The root mean square error (RMSE) described the accuracy in wave-shape prediction. The percent change of these variables for a 25% alteration of each of the model parameters was calculated. Vessel length and diameter are found to be the most important parameters determining pressure transfer. Systolic and diastolic pressure changed <3% and RMSE <1.8 mmHg for a 25% change in vessel length and diameter. To investigate how arterial tapering influences the pressure transfer, a single uniform lossless tube was modeled. This simplification introduced only small errors in systolic and diastolic pressures (1% and 0%, respectively), and wave shape was less well described (RMSE, approximately 2.1 mmHg). Local (arm) vasodilation affects the transfer function little, because it has limited effect on the reflection coefficient. Since vessel length and diameter translate into travel time, this parameter can describe the transfer accurately. We suggest that with a, preferably, noninvasively measured travel time, an accurate individualized description of pressure transfer can be obtained.

Disorders of cochlear blood flow.

PubMed

Nakashima, Tsutomu; Naganawa, Shinji; Sone, Michihiko; Tominaga, Mitsuo; Hayashi, Hideo; Yamamoto, Hiroshi; Liu, Xiuli; Nuttall, Alfred L

2003-09-01

The cochlea is principally supplied from the inner ear artery (labyrinthine artery), which is usually a branch of the anterior inferior cerebellar artery. Cochlear blood flow is a function of cochlear perfusion pressure, which is calculated as the difference between mean arterial blood pressure and inner ear fluid pressure. Many otologic disorders such as noise-induced hearing loss, endolymphatic hydrops and presbycusis are suspected of being related to alterations in cochlear blood flow. However, the human cochlea is not easily accessible for investigation because this delicate sensory organ is hidden deep in the temporal bone. In patients with sensorineural hearing loss, magnetic resonance imaging, laser-Doppler flowmetry and ultrasonography have been used to investigate the status of cochlear blood flow. There have been many reports of hearing loss that were considered to be caused by blood flow disturbance in the cochlea. However, direct evidence of blood flow disturbance in the cochlea is still lacking in most of the cases.

The mechanisms associated with the development of hypertension after exposure to lead, mercury species or their mixtures differs with the metal and the mixture ratio.

PubMed

Wildemann, Tanja M; Siciliano, Steven D; Weber, Lynn P

2016-01-02

Hypertension is considered to be the most important risk factor for the development of cardiovascular diseases. Beside life-style risk factors, exposure to lead and mercury species are increasingly discussed as potential risk factors. Although there are a few previous studies, the underlying mechanism by which exposure to lead and mercury disturb blood pressure regulation is not currently understood. Potential mechanisms are oxidative stress production, kidney damage and activation of the renin-angiotensin system (RAS), all of which can interact to cause dysregulation of blood pressure. Male rats (Wistar) were exposed to lead, inorganic mercury, methylmercury or two mixtures of all three metals for four weeks through the drinking water. The two mixture ratios were based on ratios of known reference values or environmental exposure from the literature. To investigate the potential mechanism of actions, blood pressure was measured after four weeks and compared to plasma nitrotyrosine or reduced/oxidized glutathione levels in liver as markers for oxidative stress. Plasma renin and angiotensin II levels were used as markers for RAS activation. Finally, kidney function and injury were assessed via urinary and plasma creatinine levels, creatinine clearance and urinary kidney-injury molecule (KIM-1). While exposure to lead by itself increased oxidative stress and kidney damage along with blood pressure, inorganic mercury did not affect blood pressure or any end-point examined. Conversely, methylmercury instead increased RAS activation along with blood pressure. Surprisingly, when administered as mixtures, lead no longer increased oxidative stress or altered kidney function. Moreover, the mixture based on an environmental ratio no longer had an effect on blood pressure, while the reference value ratio still retained an increase in blood pressure. Based on our results, the prominent mechanism of action associated with the development of hypertension seems to be oxidative stress and kidney damage for lead, while increased RAS activation links methylmercury to hypertension, but these mechanisms along with hypertension disappear when metals are present in some mixtures. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Protocol for a prospective collaborative systematic review and meta-analysis of individual patient data from randomized controlled trials of vasoactive drugs in acute stroke: The Blood pressure in Acute Stroke Collaboration, stage-3.

PubMed

Sandset, Else Charlotte; Sanossian, Nerses; Woodhouse, Lisa J; Anderson, Craig; Berge, Eivind; Lees, Kennedy R; Potter, John F; Robinson, Thompson G; Sprigg, Nikola; Wardlaw, Joanna M; Bath, Philip M

2018-01-01

Rationale Despite several large clinical trials assessing blood pressure lowering in acute stroke, equipoise remains particularly for ischemic stroke. The "Blood pressure in Acute Stroke Collaboration" commenced in the mid-1990s focussing on systematic reviews and meta-analysis of blood pressure lowering in acute stroke. From the start, Blood pressure in Acute Stroke Collaboration planned to assess safety and efficacy of blood pressure lowering in acute stroke using individual patient data. Aims To determine the optimal management of blood pressure in patients with acute stroke, including both intracerebral hemorrhage and ischemic stroke. Secondary aims are to assess which clinical and therapeutic factors may alter the optimal management of high blood pressure in patients with acute stroke and to assess the effect of vasoactive treatments on hemodynamic variables. Methods and design Individual patient data from randomized controlled trials of blood pressure management in participants with ischemic stroke and/or intracerebral hemorrhage enrolled during the ultra-acute (pre-hospital), hyper-acute (<6 h), acute (<48 h), and sub-acute (<168 h) phases of stroke. Study outcomes The primary effect variable will be functional outcome defined by the ordinal distribution of the modified Rankin Scale; analyses will also be carried out in pre-specified subgroups to assess the modifying effects of stroke-related and pre-stroke patient characteristics. Key secondary variables will include clinical, hemodynamic and neuroradiological variables; safety variables will comprise death and serious adverse events. Discussion Study questions will be addressed in stages, according to the protocol, before integrating these into a final overreaching analysis. We invite eligible trials to join the collaboration.

Sustained acute voltage-dependent blood pressure decrease with prolonged carotid baroreflex activation in therapy-resistant hypertension.

PubMed

Alnima, Teba; Scheffers, Ingrid; De Leeuw, Peter W; Winkens, Bjorn; Jongen-Vancraybex, Heidi; Tordoir, Jan H M; Schmidli, Jürg; Mohaupt, Markus G; Allemann, Yves; Kroon, Abraham A

2012-08-01

Chronic carotid baroreflex stimulation (Rheos system) has been shown to effectively reduce blood pressure in patients with resistant hypertension. Upon acute stimulation blood pressure also falls as a function of voltage. the aim of this study is to evaluate whether this voltage-dependent blood pressure decrease is preserved after long-term carotid baroreflex stimulation. Forty-five patients implanted with Rheos underwent a voltage response test (VRT) before the start of carotid baroreflex activation (1m), as well as after 4 (4m) and 13 months (13 m) of device implantation. After switching off the device for 10 min (0 V), we started the VRT by increasing voltage from 1 to 6 V, by 1-V steps every 5 min. Blood pressure and heart rate were measured at the end of every step. At 1m, mean blood pressure was 178/101 mmHg at 0 V and fell to 142/83 mmHg at 6 V. Heart rate fell from 75 to 65 beats/min. At 4m and 13 m mean blood pressure was significantly lower compared to 1m when VRT started at 0 V (170/96 and 161/93 mmHg, respectively). However, pattern of blood pressure decrease during VRT was comparable with this at 1m. Maximum SBP reduction during VRT did not change with long-term therapy. Acute voltage-dependent blood pressure and heart rate decrease with electrical baroreflex stimulation is preserved after at least 1 year of continuous activation in patients with resistant hypertension. This indicates that response adaptation and nerve fatigue are very unlikely in long-term carotid baroreflex activation.

Relationship between daily exposure to biomass fuel smoke and blood pressure in high-altitude Peru.

PubMed

Burroughs Peña, Melissa; Romero, Karina M; Velazquez, Eric J; Davila-Roman, Victor G; Gilman, Robert H; Wise, Robert A; Miranda, J Jaime; Checkley, William

2015-05-01

Household air pollution from biomass fuel use affects 3 billion people worldwide; however, few studies have examined the relationship between biomass fuel use and blood pressure. We sought to determine if daily biomass fuel use was associated with elevated blood pressure in high altitude Peru and if this relationship was affected by lung function. We analyzed baseline information from a population-based cohort study of adults aged ≥ 35 years in Puno, Peru. Daily biomass fuel use was self-reported. We used multivariable regression models to examine the relationship between daily exposure to biomass fuel smoke and blood pressure outcomes. Interactions with sex and quartiles of forced vital capacity were conducted to evaluate for effect modification. Data from 1004 individuals (mean age, 55.3 years; 51.7% women) were included. We found an association between biomass fuel use with both prehypertension (adjusted relative risk ratio, 5.0; 95% confidence interval, 2.6-9.9) and hypertension (adjusted relative risk ratio, 3.5; 95% confidence interval, 1.7-7.0). Biomass fuel users had a higher systolic blood pressure (7.0 mm Hg; 95% confidence interval, 4.4-9.6) and a higher diastolic blood pressure (5.9 mm Hg; 95% confidence interval, 4.2-7.6) when compared with nonusers. We did not find interaction effects between daily biomass fuel use and sex or percent predicted forced vital capacity for either systolic blood pressure or diastolic blood pressure. Biomass fuel use was associated with a higher likelihood of having hypertension and higher blood pressure in Peru. Reducing exposure to household air pollution from biomass fuel use represents an opportunity for cardiovascular prevention. © 2015 American Heart Association, Inc.

Death Rates, Psychiatric Commitments, Blood Pressure, and Perceived Crowding as a Function of Institutional Crowding.

ERIC Educational Resources Information Center

Paulus, Paul; And Others

1978-01-01

Emphasis was directed toward three factors: (1) social density; (2) spatial density; and (3) overall institutional population level. In prisons, higher population years yielded higher death rates and higher rates of psychiatric commitments. Blood pressure was higher in more crowded housing. Degree of perceived crowding was related to space per…

Identification of low and high frequency ranges for heart rate variability and blood pressure variability analyses using pharmacological autonomic blockade with atropine and propranolol in swine.

USDA-ARS?s Scientific Manuscript database

Understanding autonomic nervous system functioning, which mediates behavioral and physiological responses to stress, offers great potential for evaluation of farm animal stress and welfare. Evaluation of heart rate variability (HRV) and blood pressure variability (BPV), using time and frequency doma...

Cardiovascular Physiology of Dinosaurs.

PubMed

Seymour, Roger S

2016-11-01

Cardiovascular function in dinosaurs can be inferred from fossil evidence with knowledge of how metabolic rate, blood flow rate, blood pressure, and heart size are related to body size in living animals. Skeletal stature and nutrient foramen size in fossil femora provide direct evidence of a high arterial blood pressure, a large four-chambered heart, a high aerobic metabolic rate, and intense locomotion. But was the heart of a huge, long-necked sauropod dinosaur able to pump blood up 9 m to its head? ©2016 Int. Union Physiol. Sci./Am. Physiol. Soc.

[Clinical picture, diagnostics and prophylaxis of a syndrome in conditions of the Far North].

PubMed

Ukhocskiĭ, D M; Tegza, V Iu; Rezvantsev, M V; Vasil'chenko, V V; Belikova, T M

2014-10-01

The analysis of a clinical picture barometeosensitivity in a seaside zone of the Far North is carried out in the article. A diagnostic test included the following laboratory assessments: complete blood count, complete urinary analysis, biomedical measurement assessment, immunology blood research and functional renal test; analysis of the level of an electrolyte in the blood and hormone receptor status; and the following instrumental diagnostics: The auscultatory Korotkov's method of determining blood pressure, electrocardiography, variational pulsometry, chest X-ray, mechanocardiography, echocardiography and abdominal ultrasound; and also consultation of ophthalmologist and neuropathologist. Every patient should keep a diary "weather - health" before and after the treatment. Peculiarities of cardiovascular system, vegetative systems and neuroendocrine system of servicemen, coming to the Far North and mechanisms of development of barometeosensivity were revealed. It has been established that atmospheric pressure variation affects systolic and diastolic blood pressure, heart rate, systolic discharge, Kerdo index, effectiveness of myocardial function, end-diastolic and end-systolic volume, level of cholesterol, triglycerides, kalium, adrenalin, triiodothyronine, blood plasma and plasma renin activity in barometeosensetiv servicemen. The criteria of diagnostics of barometeosensivity in conditions of the Far North are suggested. The influence of baromemteosensivity on the combat capability of serviceman is researched.

Cerebral Autoregulation Is Minimally Influenced by the Superior Cervical Ganglion in Two- Week-Old Lambs, and Absent in Preterm Lambs Immediately Following Delivery

PubMed Central

Czynski, Adam J.; Terry, Michael H.; Deming, Douglas D.; Power, Gordon G.; Buchholz, John N.; Blood, Arlin B.

2013-01-01

Cerebral vessels in the premature newborn brain are well supplied with adrenergic nerves, stemming from the superior cervical ganglia (SCG), but their role in regulation of blood flow remains uncertain. To test this function twelve premature or two-week-old lambs were instrumented with laser Doppler flow probes in the parietal cortices to measure changes in blood flow during changes in systemic blood pressure and electrical stimulation of the SCG. In lambs delivered prematurely at ∼129 days gestation cerebral perfusion and driving pressure demonstrated a direct linear relationship throughout the physiologic range, indicating lack of autoregulation. In contrast, in lambs two-weeks of age, surgical removal of one SCG resulted in ipsilateral loss of autoregulation during pronounced hypertension. Electrical stimulation of one SCG elicited unilateral increases in cerebral resistance to blood flow in both pre-term and two-week-old lambs, indicating functioning neural pathways in the instrumented, anesthetized lambs. We conclude cerebral autoregulation is non-functional in preterm lambs following cesarean delivery. Adrenergic control of cerebral vascular resistance becomes effective in newborn lambs within two-weeks after birth but SCG-dependent autoregulation is essential only during pronounced hypertension, well above the normal range of blood pressure. PMID:24349256

Different Relevance of Peripheral, Central or Nighttime Blood Pressure Measurements in the Prediction of Chronic Kidney Disease Progression in Patients with Mild or No-Proteinuria.

PubMed

Kuczera, Piotr; Kwiecień, Katarzyna; Adamczak, Marcin; Bączkowska, Teresa; Gozdowska, Jolanta; Madziarska, Katarzyna; Augustyniak-Bartosik, Hanna; Klinger, Marian; Durlik, Magdalena; Ritz, Eberhard; Wiecek, Andrzej

2018-05-10

Arterial hypertension is one of the leading factors aggravating the course of chronic kidney disease (CKD). It seems that the novel parameters used in the assessment of the blood pressure (BP) load (i.e. central blood pressure, nighttime blood pressure) may be more precise in predicting the cardiovascular risk and the progression of CKD in comparison with the traditional peripheral blood pressure measurements in the office conditions. The aim of the study was to assess the impact of the central, or nighttime blood pressure on the progression of CKD in patients with mild or no-proteinuria (autosomal, dominant polycystic kidney disease or IgA nephropathy). In each of the enrolled 46 patients with CKD stage 3 or 4, serum creatinine concentration was assessed, eGFR (MDRD) was calculated, also central blood pressure and pulse wave velocity (PWV) was assessed and the 24-hour ambulatory blood pressure monitoring (ABPM) was conducted at the beginning of the study and then repeated after one-year observation period. During the observation period mean eGFR decreased from 44.1 (33.2-50.6) mL/min to 36.7 (29.7-46.3) mL/min. No significant differences were observed in the peripheral blood pressure or central blood pressure parameters. After one-year observation period the values of diastolic blood pressure dipping during the night significantly decreased from 16 (13-19) mmHg to 12 (10-15) mmHg; p< 0.05. The values of systolic dipping during the night or the mean BP values recorded in ABPM did not change significantly. Additionally, no significant differences in the PWV values were found. In the multivariate regression model the change of serum creatinine concentration was explained by the initial diastolic dipping values. 1. In patients with CKD stages 3 or 4 and mild or no- proteinuria, peripheral and central blood pressure did not change significantly during a one-year observation period despite the significant decline of eGFR and seems not to participate in the CKD progression. 2. Reduced magnitude of the diastolic dipping, which reflects the increase of diastolic blood pressure load during the nighttime, may play an important role in the pathogenesis of deterioration of kidney function in these patients. © 2018 The Author(s). Published by S. Karger AG, Basel.

Identification of ideal resuscitation pressure with concurrent traumatic brain injury in a rat model of hemorrhagic shock.

PubMed

Hu, Yi; Wu, Yue; Tian, Kunlun; Lan, Dan; Chen, Xiangyun; Xue, Mingying; Liu, Liangming; Li, Tao

2015-05-01

Traumatic brain injury (TBI) is often associated with uncontrolled hemorrhagic shock (UHS), which contributes significantly to the mortality of severe trauma. Studies have demonstrated that permissive hypotension resuscitation improves the survival for uncontrolled hemorrhage. What the ideal target mean arterial pressure (MAP) is for TBI with UHS remains unclear. With the rat model of TBI in combination with UHS, we investigated the effects of a series of target resuscitation pressures (MAP from 50-90 mm Hg) on animal survival, brain perfusion, and organ function before hemorrhage controlled. Rats in 50-, 60-, and 70-mm Hg target MAP groups had less blood loss and less fluid requirement, a better vital organ including mitochondrial function and better cerebral blood flow, and animal survival (8, 6, and 7 of 10, respectively) than 80- and 90-mm Hg groups. The 70-mm Hg group had a better cerebral blood flow and cerebral mitochondrial function than in 50- and 60-mm Hg groups. In contrast, 80- and 90-mm Hg groups resulted in an excessive hemodilution, a decreased blood flow, an increased brain water content, and more severe cerebral edema. A 50-mm Hg target MAP is not suitable for the resuscitation of TBI combined with UHS. A 70 mm Hg of MAP is the ideal target resuscitation pressure for this trauma, which can keep sufficient perfusion to the brain and keep good organ function including cerebral mitochondrial function. Copyright © 2015 Elsevier Inc. All rights reserved.

The Oscillating Component of the Internal Jugular Vein Flow: The Overlooked Element of Cerebral Circulation

PubMed Central

Sisini, Francesco; Toro, Eleuterio; Gambaccini, Mauro; Zamboni, Paolo

2015-01-01

The jugular venous pulse (JVP) provides valuable information about cardiac haemodynamics and filling pressures and is an indirect estimate of the central venous pressure (CVP). Recently it has been proven that JVP can be obtained by measuring the cross-sectional area (CSA) of the IJV on each sonogram of an ultrasound B-mode sonogram sequence. It has also been proven that during its pulsation the IJV is distended and hence that the pressure gradient drives the IJV haemodynamics. If this is true, then it will imply the following: (i) the blood velocity in the IJV is a periodic function of the time with period equal to the cardiac period and (ii) the instantaneous blood velocity is given by a time function that can be derived from a flow-dynamics theory that uses the instantaneous pressure gradient as a parameter. The aim of the present study is to confirm the hypothesis that JVP regulates the IJV blood flow and that pressure waves are transmitted from the heart toward the brain through the IJV wall. PMID:26783380

The pressor response to water drinking in humans : a sympathetic reflex?

NASA Technical Reports Server (NTRS)

Jordan, J.; Shannon, J. R.; Black, B. K.; Ali, Y.; Farley, M.; Costa, F.; Diedrich, A.; Robertson, R. M.; Biaggioni, I.; Robertson, D.

2000-01-01

BACKGROUND: Water drinking increases blood pressure profoundly in patients with autonomic failure and substantially in older control subjects. The mechanism that mediates this response is not known. METHODS AND RESULTS: We studied the effect of drinking tap water on seated blood pressure in 47 patients with severe autonomic failure (28 multiple system atrophy [MSA], 19 pure autonomic failure patients [PAF]). Eleven older controls and 8 young controls served as control group. We also studied the mechanisms that could increase blood pressure with water drinking. Systolic blood pressure increased profoundly with water drinking, reaching a maximum of 33+/-5 mm Hg in MSA and 37+/-7 in PAF mm Hg after 30 to 35 minutes. The pressor response was greater in patients with more retained sympathetic function and was almost completely abolished by trimethaphan infusion. Systolic blood pressure increased by 11+/-2.4 mm Hg in elderly but not in young controls. Plasma norepinephrine increased in both groups. Plasma renin activity, vasopressin, and blood volume did not change in any group. CONCLUSIONS: Water drinking significantly and rapidly raises sympathetic activity. Indeed, it raises plasma norepinephrine as much as such classic sympathetic stimuli as caffeine and nicotine. This effect profoundly increases blood pressure in autonomic failure patients, and this effect can be exploited to improve symptoms due to orthostatic hypotension. Water drinking also acutely raises blood pressure in older normal subjects. The pressor effect of oral water is an important yet unrecognized confounding factor in clinical studies of pressor agents and antihypertensive medications.

The relationship between cognitive function, depressive behaviour and sleep quality with 24-h urinary sodium excretion in patients with essential hypertension.

PubMed

Afsar, Baris

2013-03-01

Various studies have shown that sodium intake is related to increased blood pressure. However, the relationship between sodium intake and cognitive function and depression has not previously been studied. The objective of this study was to investigate the relationship between 24-h sodium excretion with cognitive function, depression and sleep quality in patients newly diagnosed with essential hypertension. All patients underwent history taking, physical examination, blood pressure measurement, 12-lead ECG evaluation, routine urine analysis, biochemical analysis and 24-h urine collection to measure urinary sodium and protein excretion and creatinine clearance, evaluation of cognitive function, depressive behaviour and sleep quality. In total, 119 patients newly diagnosed with essential hypertension (50 men and 69 women aged 54.2 ± 16.1 years) were enrolled. The 24-h urinary sodium excretion of the patients was 204.0 ± 240.4 mEq/day. The Standardized Mini Mental State Examination (SMMSE), Pittsburgh Sleep Quality Index and Beck Depression Inventory scores of the patients were 26.0 ± 2.7, 5.6 ± 3.1 and 21.6 ± 13.5, respectively. Spearman correlation analysis revealed that 24-h urinary sodium excretion was correlated with age (rho -0.258, p = 0.005), systolic blood pressure (rho 0.219, p = 0.017), diastolic blood pressure (rho 0.195, p = 0.034), creatinine clearance (rho 0.414, p < 0.0001) and SMMSE score (rho -0.257, p = 0.005). Stepwise linear regression of independent factors revealed that gender (p < 0.0001), creatinine clearance (p < 0.0001), systolic blood pressure (p = 0.031) and SMMSE score (p < 0.0001) were independently related to logarithmically converted 24-h sodium excretion. The current study demonstrated that better cognitive function, but not depressive behaviour and sleep disturbance, is related to decreased sodium intake as evaluated by 24-h urinary sodium excretion. Studies are needed to highlight the mechanisms regarding the relationship between cognitive function and sodium intake.

Non-Invasive Method of Determining Absolute Intracranial Pressure

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

2004-01-01

A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

Urinary albumin excretion is associated with nocturnal systolic blood pressure in resistant hypertensives.

PubMed

Oliveras, Anna; Armario, Pedro; Martell-Clarós, Nieves; Ruilope, Luis M; de la Sierra, Alejandro

2011-03-01

Microalbuminuria is a known marker of subclinical organ damage. Its prevalence is higher in patients with resistant hypertension than in subjects with blood pressure at goal. On the other hand, some patients with apparently well-controlled hypertension still have microalbuminuria. The current study aimed to determine the relationship between microalbuminuria and both office and 24-hour ambulatory blood pressure. A cohort of 356 patients (mean age 64 ± 11 years; 40.2% females) with resistant hypertension (blood pressure ≥ 140 and/or 90 mm Hg despite treatment with ≥ 3 drugs, diuretic included) were selected from Spanish hypertension units. Patients with estimated glomerular filtration rate <30 mL/min/1.73 m(2) were excluded. All patients underwent clinical and demographic evaluation, complete laboratory analyses, and good technical-quality 24-hour ambulatory blood pressure monitoring. Urinary albumin/creatinine ratio was averaged from 3 first-morning void urine samples. Microalbuminuria (urinary albumin/creatinine ratio ≥ 2.5 mg/mmol in males or ≥ 3.5 mg/mmol in females) was detected in 46.6%, and impaired renal function (estimated glomerular filtration rate <60 mL/min/1.73 m(2)) was detected in 26.8%. Bivariate analyses showed significant associations of microalbuminuria with older age, reduced estimated glomerular filtration rate, increased nighttime systolic blood pressure, and elevated daytime, nighttime, and 24-hour diastolic blood pressure. In a logistic regression analysis, after age and sex adjustment, elevated nighttime systolic blood pressure (multivariate odds ratio, 1.014 [95% CI, 1.001 to 1.026]; P=0.029) and reduced estimated glomerular filtration rate (multivariate odds ratio, 2.79 [95% CI, 1.57 to 4.96]; P=0.0005) were independently associated with the presence of microalbuminuria. We conclude that microalbuminuria is better associated with increased nighttime systolic blood pressure than with any other office and 24-hour ambulatory blood pressure monitoring parameters.

Rodent Studies of Cardiovascular Deconditioning

NASA Technical Reports Server (NTRS)

Shoukas, Artin A.

1999-01-01

Changes in blood pressure can occur for two reasons: 1) A decrease in cardiac output resulting from the altered contractility of the heart or through changes in venous filling pressure via the Frank Starling mechanism or; 2) A change in systemic vascular resistance. The observed changes in cardiac output and blood pressure after long term space flight cannot be entirely explained through changes in contractility or heart rate alone. Therefore, alterations in filling pressure mediated through changes in systemic venous capacitance and arterial resistance function may be important determinants of cardiac output and blood pressure after long term space flight. Our laboratory and previous studies have shown the importance of veno-constriction mediated by the carotid sinus baroreceptor reflex system on overall circulatory homeostasis and in the regulation of cardiac output. Our proposed experiments test the overall hypothesis that alterations in venous capacitance function and arterial resistance by the carotid sinus baroreceptor reflex system are an important determinant of the cardiac output and blood pressure response seen in astronauts after returning to earth from long term exposure to microgravity. This hypothesis is important to our overall understanding of circulatory adjustments made during long term space flight. It also provides a framework for investigating counter measures to reduce the incidence of orthostatic hypotension caused by an attenuation of cardiac output. We continue to use hind limb unweighted (HLU) rat model to simulate the patho physiological effects as they relate to cardiovascular deconditioning in microgravity. We have used this model to address the hypothesis that microgravity induced cardiovascular deconditioning results in impaired vascular responses and that these impaired vascular responses result from abnormal alpha-1 AR signaling. The impaired vascular reactivity results in attenuated blood pressure and cardiac output responses to an orthostatic challenge. We have used in vitro vascular reactivity assays to explore abnormalities in vascular responses in vessels from HLU animals and, cardiac output (CO), blood pressure (BP) and heart rate (HR) measurements to characterize changes in hemodynamics following HLU.

Sibutramine versus continuous positive airway pressure in obese obstructive sleep apnoea patients.

PubMed

Ferland, A; Poirier, P; Sériès, F

2009-09-01

The aim of the present study was to compare the efficacy of 1 yr of sibutramine-induced weight loss versus continuous positive airway pressure (CPAP) treatment on sleep-disordered breathing, cardiac autonomic function and systemic blood pressure in obese patients with obstructive sleep apnoea. Subjects with a body mass index of > or =30 kg.m(-2) without previous treatment for obstructive sleep apnoea underwent either sibutramine (n = 22) or CPAP (n = 18) treatment for 1 yr. Sibutramine induced a 5.4+/-1.4 kg decrease in body weight compared to the CPAP group, in which no changes in anthropometric variables were observed. The CPAP treatment improved all sleep and respiratory variables, whereas sibutramine-induced weight loss improved only nocturnal arterial oxygen saturation profile. Only CPAP treatment improved night-time systolic and diastolic blood pressure and 24-h and daytime ambulatory diastolic blood pressure. Sibutramine-induced weight loss had no impact on indices of heart rate variability, whereas CPAP treatment increased daytime time domain indices. CPAP treatment for 1 yr had beneficial impacts on nocturnal breathing disturbances, and improved nocturnal oxygenation, night-time systolic and diastolic blood pressure, and daytime cardiac parasympathetic modulation. Sibutramine did not improve sleep-disordered breathing, systemic blood pressure or heart rate variability. There were no adverse effects, such as increment in blood pressure or arrhythmias, associated with this treatment regimen.

Chronic Blockade of Brain Endothelin Receptor Type-A (ETA) Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats.

PubMed

Cassinotti, Luis R; Guil, María J; Schöller, Mercedes I; Navarro, Mónica P; Bianciotti, Liliana G; Vatta, Marcelo S

2018-02-27

Overactivity of the sympathetic nervous system and central endothelins (ETs) are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB) also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Following brain ET receptor type A (ET A ) blockade by BQ610 (selective antagonist), transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH) were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ET A blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein) in the right OB of hypertensive animals. However, ET A blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ET A are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

Implications of persistent prehypertension for ageing-related changes in left ventricular geometry and function: the MONICA/KORA Augsburg study.

PubMed

Markus, Marcello Ricardo Paulista; Stritzke, Jan; Lieb, Wolfgang; Mayer, Björn; Luchner, Andreas; Döring, Angela; Keil, Ulrich; Hense, Hans-Werner; Schunkert, Heribert

2008-10-01

It is unclear whether persistent prehypertension causes structural or functional alterations of the heart. We examined echocardiographic data of 1005 adults from a population-based survey at baseline in 1994/1995 and at follow-up in 2004/2005. We compared individuals who had either persistently normal (<120 mmHg systolic and <80 mmHg diastolic, n = 142) or prehypertensive blood pressure (120-139 mmHg or 80-89 mmHg, n = 119) at both examinations using multivariate regression modeling. Over 10 years, left ventricular end-diastolic diameters were stable and did not differ between the two groups. However, the prehypertensive blood pressure group displayed more pronounced ageing-related increases of left ventricular wall thickness (+4.7 versus +11.9%, P < 0.001) and left ventricular mass (+8.6 versus +15.7%, P = 0.006). Prehypertension was associated with a raised incidence of left ventricular concentric remodeling (adjusted odds ratio 10.7, 95% confidence interval 2.82-40.4) and left ventricular hypertrophy (adjusted odds ratio 5.33, 1.58-17.9). The ratio of early and late diastolic peak transmitral flow velocities (E/A) decreased by 7.7% in the normal blood pressure versus 15.7% in the prehypertensive blood pressure group (P = 0.003) and at follow-up the ratio of early diastolic peak transmitral flow and early diastolic peak myocardial relaxation velocities (E/EM) was higher (9.1 versus 8.5, P = 0.031) and left atrial size was larger (36.5 versus 35.3 mm, P = 0.024) in the prehypertensive blood pressure group. Finally, the adjusted odds ratio for incident diastolic dysfunction was 2.52 (1.01-6.31) for the prehypertensive blood pressure group. Persistent prehypertension accelerates the development of hypertrophy and diastolic dysfunction of the heart.

Energy harvesting from arterial blood pressure for powering embedded brain sensors

NASA Astrophysics Data System (ADS)

Nanda, Aditya; Karami, M. Amin

2016-04-01

This paper investigates energy harvesting from arterial blood pressure via the piezoelectric effect by using a novel streaked cylinder geometry for the purpose of powering embedded micro-sensors in the brain. Initially, we look at the energy harvested by a piezoelectric cylinder placed inside an artery acted upon by blood pressure. Such an arrangement would be tantamount to constructing a stent out of piezoelectric materials. A stent is a cylinder placed in veins and arteries to prevent obstruction in blood flow. The governing equations of a conductor coated piezoelectric cylinder are obtained using Hamilton's principle. Pressure acting in arteries is radially directed and this is used to simplify the modal analysis and obtain the transfer function relating pressure to the induced voltage across the surface of the harvester. The power harvested by the cylindrical harvester is obtained for different shunt resistances. Radially directed pressure occurs elsewhere and we also look at harvesting energy from oil flow in pipelines. Although the energy harvested by the cylindrical energy harvester is significant at resonance, the natural frequency of the system is found to be very high. To decrease the natural frequency, we propose a novel streaked stent design by cutting it along the length, transforming it to a curved plate and decreasing the natural frequency. The governing equations corresponding to the new geometry are derived using Hamilton's principle and modal analysis is used to obtain the transfer function.

Are middle-age blood pressure levels related to color vision impairment? The Okubo Color Study.

PubMed

Shoji, Takuhei; Sato, Hiroki; Chihara, Etsuo; Sakurai, Yutaka

2015-01-01

We sought to investigate the association between blood pressure levels and prevalence of acquired color vision impairment in middle-aged Japanese men. Participants underwent color vision testing, ophthalmological examination, standardized interview, physical record examination, and venous blood examination. Cardiovascular disease risk factors were determined based on blood and physical examination results and the interview. Logistic regression analysis was performed after adjusting for body mass index, systemic dyslipidemia, diabetes, cataract, glaucoma, smoking status, and drinking status. Of 1,042 men, 872 were eligible for the study, 130 failed the Lanthony 15-hue desaturated panel (D-15 DS) diagnosed as acquired color vision impairment 15-hue, and 31 failed the Farnsworth-Munsell 100-hue test diagnosed as acquired color vision impairment 100-hue. Diastolic blood pressure was significantly correlated with both acquired color vision impairment in 100-hue patients (adjusted odds ratio (OR) for 10-mm Hg increases = 1.42; 95% confidence interval (CI) = 1.00-2.02) and acquired color vision impairment in 15-hue patients (adjusted OR for 10-mm Hg increases = 1.25; 95% CI = 1.04-1.51). The multiple-adjusted ORs for acquired color vision impairment 100-hue patients and acquired color vision impairment 15-hue patients were 7.13 (95% CI = 1.72-27.88) and 4.37 (95% CI = 1.69-11.03), respectively, for the highest blood pressure category (systolic blood pressure ≥ 160 and diastolic blood pressure ≥ 100 mm Hg) compared with those for the lowest blood pressure category (systolic blood pressure <120 and diastolic blood pressure <80 mm Hg). Tests for trends were significant (P < 0.05) in both analyses. Hypertension in middle-aged men may negatively modify vision-associated neuronal function. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Primary Study on Noninvasive Detection of Vascular Function Based on Finger Temperature Change].

PubMed

Dong, Qing; Li, Xia; Wan, Yungao; Lu, Gaoquan; Wang, Xinxin; Zhang, Kuan

2016-02-01

By studying the relationship between fingertip temperature changes and arterial function during vascular reactivity test, we established a new non-invasive method for detecting vascular function, in order to provide an assistance for early diagnosis and prevention of cardiovascular diseases. We customized three modules respectively for blood occlusion, measurement of finger temperature and blood oxygen acquisition, and then we established the hardware of data acquisition system. And the software was programmed with Labview. Healthy subjects [group A, n = 24, (44.6 ± 9.0) years] and subjects with cardiovascular diseases [group B, n = 33, (57.2 ± 9.9) years)] were chosen for the study. Subject's finger temperature, blood oxygen and occlusion pressure of block side during and after unilateral arm brachial artery occlusion were recorded, as well as some other regular physiological indexes. By time-domain analysis, we extracted 12 parameters from fingertip temperature signal, including the initial temperature (Ti), temperature rebound (TR), the time of the temperature recovering to initial status (RIt) and other parameters from the finger temperature signal. We in the experiment also measured other regular physiological body mass index (BMI), systolic blood pressure (SBP), diastiolic blood pressure (DBP) and so on. Results showed that 8 parameters difference between the two group of data were significant. based on the statistical results. A discriminant function of vascular function status was established afterwards. We found in the study that the changes of finger temperature during unilateral arms brachial artery occlusion and open were closely related to vascular function. We hope that the method presented in this article could lay a foundation of early detection of vascular function.

Acute Air Pollution Exposure and Blood Pressure at Delivery Among Women With and Without Hypertension

PubMed Central

Männistö, Tuija; Liu, Danping; Leishear, Kira; Sherman, Seth; Laughon, S. Katherine

2015-01-01

BACKGROUND Chronic air pollution exposure increases risk for hypertensive disorders of pregnancy, but the effect of acute air pollution exposure on blood pressure during pregnancy is less well known. METHODS We studied 151,276 singleton term deliveries from the Consortium on Safe Labor (2002–2008) with clinical blood pressure measured at admission to labor/delivery and diagnoses of hypertensive disorders collected from electronic medical records and hospital discharge summaries. Air pollution exposures were estimated for the admission hour and the 4 hours preceding admission using a modified version of the Community Multiscale Air Quality models and observed air monitoring data. Blood pressure was categorized as normal; high normal; and mild, moderate, or severe hypertension based on pregnancy cut points. Adjusted ordinal logistic regression estimated the odds of women having a higher admission blood pressure category as a function of air pollutant, hypertensive disorders, and their interaction effect. RESULTS Odds of high blood pressure at admission to labor/delivery were increased in normotensive women after exposure to nitrogen oxides (by 0.2%/5 units), sulfur dioxide (by 0.3%/1 unit), carbon monoxide and several air toxics (by 3%–4%/high exposure). The effects were often similar or stronger among women with gestational hypertension and preeclampsia. Exposure to particulate matter <10 μm increased odds of high blood pressure in women with preeclampsia by 3%/5 units. CONCLUSIONS Air pollution can influence admission blood pressure in term deliveries and may increase likelihood of preeclampsia screening at delivery admission. PMID:24795401

Evaluating combined effect of noise and heat on blood pressure changes among males in climatic chamber.

PubMed

Dehghan, Habibollah; Bastami, Mohamad Taghi; Mahaki, Behzad

2017-01-01

Exposure to noise and heat causes individuals to experience some changes in the function of cardiovascular system in workplaces. This study aimed to find the combined effect of heat and noise on systolic and diastolic types of blood pressure in experimentally controlled conditions. This quasi-experimental study was performed with 12 male students in a climatic chamber in 2014. Blood pressure including systolic and diastolic was measured in the following conditions: 15 min after rest in exposure to heat (40°C, relative humidity [RH]: 30%), exposure to noise with 75, 85, and 95 dB rates in thermal comfort condition (22.1 ± 0.9 wet-bulb globe temperature), and combined exposure to heat (40°C, RH: 30%) and noise with 75, 85, and 95 dB. Friedman test was used to analyze the data. The mean change of systolic blood pressure was different significantly before and after exposure to heat and noise levels including 75, 85, and 95 dB ( P = 0.015, P = 0.001, P > 0.001, P = 0.027, respectively). Although systolic and diastolic blood pressures changed drastically, it was not significantly different in simultaneous exposure to heat and noise. Both systolic and diastolic blood pressures decreased in exposure to heat, while exposure to different levels of noise elevates systolic and diastolic blood pressures. However, when exposed to a combination of heat and noise, subtle changes of blood pressure were traced, which can be characterized as average, considering heat-only and noise-only tension situations.

Is blood pressure reduction a valid surrogate endpoint for stroke prevention? an analysis incorporating a systematic review of randomised controlled trials, a by-trial weighted errors-in-variables regression, the surrogate threshold effect (STE) and the biomarker-surrogacy (BioSurrogate) evaluation schema (BSES)

PubMed Central

2012-01-01

Background Blood pressure is considered to be a leading example of a valid surrogate endpoint. The aims of this study were to (i) formally evaluate systolic and diastolic blood pressure reduction as a surrogate endpoint for stroke prevention and (ii) determine what blood pressure reduction would predict a stroke benefit. Methods We identified randomised trials of at least six months duration comparing any pharmacologic anti-hypertensive treatment to placebo or no treatment, and reporting baseline blood pressure, on-trial blood pressure, and fatal and non-fatal stroke. Trials with fewer than five strokes in at least one arm were excluded. Errors-in-variables weighted least squares regression modelled the reduction in stroke as a function of systolic blood pressure reduction and diastolic blood pressure reduction respectively. The lower 95% prediction band was used to determine the minimum systolic blood pressure and diastolic blood pressure difference, the surrogate threshold effect (STE), below which there would be no predicted stroke benefit. The STE was used to generate the surrogate threshold effect proportion (STEP), a surrogacy metric, which with the R-squared trial-level association was used to evaluate blood pressure as a surrogate endpoint for stroke using the Biomarker-Surrogacy Evaluation Schema (BSES3). Results In 18 qualifying trials representing all pharmacologic drug classes of antihypertensives, assuming a reliability coefficient of 0.9, the surrogate threshold effect for a stroke benefit was 7.1 mmHg for systolic blood pressure and 2.4 mmHg for diastolic blood pressure. The trial-level association was 0.41 and 0.64 and the STEP was 66% and 78% for systolic and diastolic blood pressure respectively. The STE and STEP were more robust to measurement error in the independent variable than R-squared trial-level associations. Using the BSES3, assuming a reliability coefficient of 0.9, systolic blood pressure was a B + grade and diastolic blood pressure was an A grade surrogate endpoint for stroke prevention. In comparison, using the same stroke data sets, no STEs could be estimated for cardiovascular (CV) mortality or all-cause mortality reduction, although the STE for CV mortality approached 25 mmHg for systolic blood pressure. Conclusions In this report we provide the first surrogate threshold effect (STE) values for systolic and diastolic blood pressure. We suggest the STEs have face and content validity, evidenced by the inclusivity of trial populations, subject populations and pharmacologic intervention populations in their calculation. We propose that the STE and STEP metrics offer another method of evaluating the evidence supporting surrogate endpoints. We demonstrate how surrogacy evaluations are strengthened if formally evaluated within specific-context evaluation frameworks using the Biomarker- Surrogate Evaluation Schema (BSES3), and we discuss the implications of our evaluation of blood pressure on other biomarkers and patient-reported instruments in relation to surrogacy metrics and trial design. PMID:22409774

Blood pressure, salivary cortisol, and inflammatory cytokine outcomes in senior female cancer survivors enrolled in a tai chi chih randomized controlled trial.

PubMed

Campo, Rebecca A; Light, Kathleen C; O'Connor, Kathleen; Nakamura, Yoshio; Lipschitz, David; LaStayo, Paul C; Pappas, Lisa M; Boucher, Kenneth M; Irwin, Michael R; Hill, Harry R; Martins, Thomas B; Agarwal, Neeraj; Kinney, Anita Y

2015-03-01

Older cancer survivors are a vulnerable population due to an increased risk for chronic diseases (e.g., cardiovascular disease) compounded with treatment late-effects and declines in physical functioning. Therefore, interventions that reduce chronic disease risk factors (i.e., blood pressure, chronic inflammation, and cortisol) are important in this population. Tai chi chih (TCC) is a mind-body exercise associated with reductions in chronic disease risk factors, but has not been examined with older cancer survivors. In a feasibility randomized controlled trial of TCC, we examined secondary outcomes of blood pressure, salivary cortisol, and inflammatory cytokines (interleukin (IL)-6, IL-12, tumor necrosis factor-α, IL-10, IL-4) due to their implications in chronic diseases. Sixty-three senior female cancer survivors (M age = 67 years, SD = 7.15) with physical functioning limitations (SF-12 physical functioning ≤80 or role-physical ≤72) were randomized to 12-weeks (60-min, three times a week) of TCC or Health Education control (HEC) classes. Resting blood pressure, 1-day salivary cortisol samples, and fasting plasma samples for cytokine multiplex assays were collected at baseline and 1-week post-intervention. Controlling for baseline values, the TCC group had significantly lower systolic blood pressure (SBP, p = 0.002) and cortisol area-under-curve (AUC, p = 0.02) at post-intervention than the HEC group. There was no intervention effect on inflammatory cytokines (p's > 0.05). This TCC feasibility trial was associated with significant reductions in SBP and cortisol AUC in senior female cancer survivors. Larger, definitive trials are needed to confirm these findings. Senior survivors' have an increased risk for chronic diseases; however, TCC interventions may help reduce associated risk factors.

Glucocorticoid receptor haploinsufficiency causes hypertension and attenuates hypothalamic-pituitary-adrenal axis and blood pressure adaptions to high-fat diet

PubMed Central

Michailidou, Z.; Carter, R. N.; Marshall, E.; Sutherland, H. G.; Brownstein, D. G.; Owen, E.; Cockett, K.; Kelly, V.; Ramage, L.; Al-Dujaili, E. A. S.; Ross, M.; Maraki, I.; Newton, K.; Holmes, M. C.; Seckl, J. R.; Morton, N. M.; Kenyon, C. J.; Chapman, K. E.

2008-01-01

Glucocorticoid hormones are critical to respond and adapt to stress. Genetic variations in the glucocorticoid receptor (GR) gene alter hypothalamic-pituitary-adrenal (HPA) axis activity and associate with hypertension and susceptibility to metabolic disease. Here we test the hypothesis that reduced GR density alters blood pressure and glucose and lipid homeostasis and limits adaption to obesogenic diet. Heterozygous GRβgeo/+ mice were generated from embryonic stem (ES) cells with a gene trap integration of a β-galactosidase-neomycin phosphotransferase (βgeo) cassette into the GR gene creating a transcriptionally inactive GR fusion protein. Although GRβgeo/+ mice have 50% less functional GR, they have normal lipid and glucose homeostasis due to compensatory HPA axis activation but are hypertensive due to activation of the renin-angiotensin-aldosterone system (RAAS). When challenged with a high-fat diet, weight gain, adiposity, and glucose intolerance were similarly increased in control and GRβgeo/+ mice, suggesting preserved control of intermediary metabolism and energy balance. However, whereas a high-fat diet caused HPA activation and increased blood pressure in control mice, these adaptions were attenuated or abolished in GRβgeo/+ mice. Thus, reduced GR density balanced by HPA activation leaves glucocorticoid functions unaffected but mineralocorticoid functions increased, causing hypertension. Importantly, reduced GR limits HPA and blood pressure adaptions to obesogenic diet.—Michailidou, Z., Carter, R. N., Marshall, E., Sutherland, H. G., Brownstein, D. G., Owen, E., Cockett, K., Kelly, V., Ramage, L., Al-Dujaili, E. A. S., Ross, M., Maraki, I., Newton, K., Holmes, M. C., Seckl, J. R., Morton, N. M., Kenyon, C. J., Chapman, K. E. Glucocorticoid receptor haploinsufficiency causes hypertension and attenuates hypothalamic-pituitary-adrenal axis and blood pressure adaptions to high-fat diet. PMID:18697839

Eprosartan-based hypertension therapy, systolic arterial blood pressure and cognitive function: analysis of Middle East data from the OSCAR study.

PubMed

Radaideh, Ghazi Ahmad; Choueiry, Patrick; Ismail, Amr; Eid, Elie; Berrou, Jean-Pascal; Sedefdjian, Armand; Sévenier, Frank; Pathak, Atul

2011-01-01

Studies have indicated a relationship between hypertension and cognitive function. The possible effect of antihypertensive therapy on cognitive disorders is therefore a matter of interest. The Observational Study on Cognitive function And SBP Reduction (OSCAR) was an open-label, multinational trial designed to evaluate the impact of eprosartan-based antihypertensive therapy on cognitive function in patients with essential hypertension. Eprosartan 600 mg/day for 6 months (with provision for additional medication as needed) was initiated in hypertensive subjects aged ≥ 50 years. A total of 853 patients in an intention-to-treat cohort from seven countries of the Middle East was identified for subgroup analysis. Arterial blood pressure was reduced significantly (P < 0.001) during the study: At the end of 6 months of eprosartan-based therapy, the mean (±SD) reduction from baseline was 32.1 ± 14.3/14.6.3 ± 8.6 mmHg (P < 0.001). Mean pulse pressure was reduced by 18.3 ± 13.1 mmHg (P < 0.0001 vs baseline). Blood pressure was normalized (systolic <140 mmHg and diastolic <90 mmHg) in 68.2% of patients. The overall mean Mini-Mental State Examination (MMSE) score after 6 months of eprosartan-based therapy was one-point higher than at baseline (P < 0.001). MMSE score on completion of 6 months' follow-up was either unchanged or increased from baseline in 793 (93%) individuals and decreased in 60 (7%). Factors associated with stability of or improvement in cognitive function included MMSE score at baseline, diastolic blood pressure (DBP) at baseline, and treatment-induced change in DBP. Results from the Middle East subgroup of OSCAR are supportive of the hypothesis that antihypertensive therapy based on angiotensin-receptor blocker therapy with eprosartan may be associated with preservation or improvement of cognitive function.

Endothelial function is unaffected by changing between carvedilol and metoprolol in patients with heart failure-a randomized study

PubMed Central

2011-01-01

Background Carvedilol has been shown to be superior to metoprolol tartrate to improve clinical outcomes in patients with heart failure (HF), yet the mechanisms responsible for these differences remain unclear. We examined if there were differences in endothelial function, insulin stimulated endothelial function, 24 hour ambulatory blood pressure and heart rate during treatment with carvedilol, metoprolol tartrate and metoprolol succinate in patients with HF. Methods Twenty-seven patients with mild HF, all initially treated with carvedilol, were randomized to a two-month treatment with carvedilol, metoprolol tartrate or metoprolol succinate. Venous occlusion plethysmography, 24-hour blood pressure and heart rate measurements were done before and after a two-month treatment period. Results Endothelium-dependent vasodilatation was not affected by changing from carvedilol to either metoprolol tartrate or metoprolol succinate. The relative forearm blood flow at the highest dose of serotonin was 2.42 ± 0.33 in the carvedilol group at baseline and 2.14 ± 0.24 after two months continuation of carvedilol (P = 0.34); 2.57 ± 0.33 before metoprolol tartrate treatment and 2.42 ± 0.55 after treatment (p = 0.74) and in the metoprolol succinate group 1.82 ± 0.29 and 2.10 ± 0.37 before and after treatment, respectively (p = 0.27). Diurnal blood pressures as well as heart rate were also unchanged by changing from carvedilol to metoprolol tartrate or metoprolol succinate. Conclusion Endothelial function remained unchanged when switching the beta blocker treatment from carvedilol to either metoprolol tartrate or metoprolol succinate in this study, where blood pressure and heart rate also remained unchanged in patients with mild HF. Trial registration Current Controlled Trials NCT00497003 PMID:21999413

Prenatal lead exposure and childhood blood pressure and kidney function.

PubMed

Skröder, Helena; Hawkesworth, Sophie; Moore, Sophie E; Wagatsuma, Yukiko; Kippler, Maria; Vahter, Marie

2016-11-01

Exposure to lead, a common environmental pollutant, is known to cause cardiovascular and nephrotoxic effects in adults. Potential effects of early-life lead exposure on these functions are, however, less well characterized. To assess blood pressure and kidney function in preschool-aged children in relation to prenatal lead exposure. This prospective study in rural Bangladesh measured children's systolic and diastolic blood pressure in triplicate at the follow-up at 4.5±0.11 years. Their kidney function was assessed by the estimated glomerular filtration rate (eGFR), calculated based on serum cystatin C concentrations, and by kidney volume, measured by sonography. Exposure to lead was assessed by concentrations in the mothers' blood (erythrocyte fraction; Ery-Pb) in gestational weeks (GW) 14 and 30, the effects of which were evaluated separately in multivariable-adjusted linear regression analyses. We found no associations between maternal exposure to lead [n~1500 for GW14 and 700 for GW30] and children's blood pressure or eGFR. However, we found an inverse association between late gestation lead and kidney volume, although the sample size was limited (n=117), but not with early gestation lead (n=573). An increase of 85µg/kg in Ery-Pb (median concentration at GW30) was associated with a 6.0cm 3 /m 2 decrease in kidney volume (=0.4SD; p=0.041). After stratifying on gender, there seemed to be a somewhat stronger association in girls. Prenatal lead exposure may cause long-lasting effects on the kidney. This warrants follow-up studies in older children, as well as additional studies in other populations. Copyright © 2016. Published by Elsevier Inc.

Desoxycorticosterone pivalate-salt treatment leads to non-dipping hypertension in Per1 knockout mice.

PubMed

Solocinski, K; Holzworth, M; Wen, X; Cheng, K-Y; Lynch, I J; Cain, B D; Wingo, C S; Gumz, M L

2017-05-01

Increasing evidence demonstrates that circadian clock proteins are important regulators of physiological functions including blood pressure. An established risk factor for developing cardiovascular disease is the absence of a blood pressure dip during the inactive period. The goal of the present study was to determine the effects of a high salt diet plus mineralocorticoid on PER1-mediated blood pressure regulation in a salt-resistant, normotensive mouse model, C57BL/6J. Blood pressure was measured using radiotelemetry. After control diet, wild-type (WT) and Per1 (KO) knockout mice were given a high salt diet (4% NaCl) and the long-acting mineralocorticoid deoxycorticosterone pivalate. Blood pressure and activity rhythms were analysed to evaluate changes over time. Blood pressure in WT mice was not affected by a high salt diet plus mineralocorticoid. In contrast, Per1 KO mice exhibited significantly increased mean arterial pressure (MAP) in response to a high salt diet plus mineralocorticoid. The inactive/active phase ratio of MAP in WT mice was unchanged by high salt plus mineralocorticoid treatment. Importantly, this treatment caused Per1 KO mice to lose the expected decrease or 'dip' in blood pressure during the inactive compared to the active phase. Loss of PER1 increased sensitivity to the high salt plus mineralocorticoid treatment. It also resulted in a non-dipper phenotype in this model of salt-sensitive hypertension and provides a unique model of non-dipping. Together, these data support an important role for the circadian clock protein PER1 in the modulation of blood pressure in a high salt/mineralocorticoid model of hypertension. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Mechanisms responsible for decreased glomerular filtration in hibernation and hypothermia

NASA Technical Reports Server (NTRS)

Tempel, G. E.; Musacchia, X. J.; Jones, S. B.

1977-01-01

Measurements of blood pressure, heart rate, red blood cell and plasma volumes, and relative distribution of cardiac output were made on hibernating and hypothermic adult male and female golden hamsters weighing 120-140 g to study the mechanisms underlying the elimination or marked depression of renal function in hibernation and hypothermia. The results suggest that the elimination or marked depression in renal function reported in hibernation and hypothermia may partly be explained by alterations in cardiovascular system function. Renal perfusion pressure which decreases nearly 60% in both hibernation and hypothermia and a decrease in plasma volume of roughly 35% in the hypothermic animal might both be expected to markedly alter glomerular function.

Relationships among Blood Pressure, Triglycerides and Verbal Learning in African Americans

PubMed Central

Sims, Regina C.; Madhere, Serge; Gordon, Shalanda; Clark, Elijah; Abayomi, Kobi A.; Callender, Clive O.; Campbell, Alfonso L.

2013-01-01

Background Individuals at greater risk for cardiovascular disease (CVD) display poorer cognitive functioning across various cognitive domains. This finding is particularly prevalent among older adults; however, few studies examine these relationships among younger adults or among African Americans. Purpose The objective was to examine the relationships among 2 cardiovascular risk factors, elevated blood pressure and elevated triglycerides, and verbal learning in a community-based sample of African Americans. Methods Measurements of blood pressure and triglycerides were obtained in 121 African-American adults and compared to performance on 3 domains of the California Verbal Learning Test-II (CVLT-II). Results Blood pressure was not related to CVLT-II performance. Triglyceride levels were inversely related to CVLT-II performance. Higher triglyceride levels were associated with poorer immediate, short delay and long delay recall. Conclusions Consistent with studies involving older participants, the current investigation shows that in a nonelderly sample of African Americans, triglyceride levels may be related to cognitive functioning. Because early detection and intervention of vascular-related cognitive impairment may have a salutary effect, future studies should include younger adults to highlight the impact of cardiovascular risk on cognition. PMID:18942281

Psycho-Physiological Responses by Listening to Some Sounds from Our Daily Life

NASA Astrophysics Data System (ADS)

Sakamoto, H.; Hayashi, F.; Tsujikawa, M.; Sugiura, S.

1997-08-01

This study was made to clarify the relationship between mode of identification, mode of emotion and physiological response to noise. Twenty-six subjects, young females, listened to six different daily sounds for 150 s through head phones. The level of sound was 60-61LAcq. The pulse wave and blood pressure were observed, and pulse wave interval, wave height and maximum and minimum blood pressures were measured. Measurements were taken twice once 30 s before listening and again during the final 30 s of listening. The ratio of the latter value to the former value was used as the index for the evaluation of change. Immediately after the listening session, identification of the sound source and emotional response were surveyed via a questionnaire and the sounds were judged as related to comfort or discomfort. In the case of incorrect identification, physiological functions were not seen to change significantly. However, in the case of correct identification, maximum and minimum blood pressures were significantly increased form the pre-listening values. The physiological functions of the discomfort group did not change significantly. In the comfort group, wave height was decreased and blood pressure was significantly elevated.

Cardiopulmonary effects of thiopental versus propofol as an induction agent prior to isoflurane anesthesia in chair trained rhesus macaques (Macaca mulatta).

PubMed

Choi, Yun-Jung; Park, Hye-Jin; Kim, Hyeon-Ho; Lee, Yun-Jin; Jung, Kyeong-Cheon; Park, Seong-Hoe; Lee, Jae-Il

2016-03-01

The purpose of this study was to evaluate the effects of thiopental versus propofol on cardiopulmonary functions, when used as an induction agent prior to isoflurane anesthesia in rhesus monkeys. Eight healthy rhesus monkeys weighing 3.72 to 5.7 kg, 4-5 years old, were used in the study. Anesthesia was induced with thiopental or propofol intravenous injection, and then maintained with isoflurane in oxygen for 45 minutes. Cardiopulmonary measurements were obtained before and 5, 15, 30, 45, and 60 minutes after induction. The induction doses of thiopental and propofol were 19.41±0.54 and 9.33±1.02 mg/kg, respectively. In both groups, the values of heart rate, respiratory rate, temperature, systolic blood pressure, mean blood pressure, diastolic blood pressure, pH, and lactate were decreased, while the values of partial pressure of carbon dioxide, partial pressure of oxygen, total carbon dioxide, bicarbonate, oxygen saturation, and base excess in the extracellular fluid were increased, as compared with baseline. Systolic blood pressure was significantly lower in thiopental group compare to propofol group. Induction time was very short in both agents but not revealed a significant difference between both groups. However, recovery time was extremely faster in the propofol group. Our results demonstrated that propofol provides a minor suppression in systolic arterial blood pressure than thiopental sodium. In addition, propofol have a fast recovery effect from the anesthesia as well. Furthermore, it is suggested that thiopental sodium could also be used to induce anesthesia instead of propofol, despite slight more suppression of cardiopulmonary function compared to thiopental sodium.

Alanine increases blood pressure during hypotension

NASA Technical Reports Server (NTRS)

Conlay, L. A.; Maher, T. J.; Wurtman, R. J.

1990-01-01

The effect of L-alanine administration on blood pressure (BP) during haemorrhagic shock was investigated using anesthetized rats whose left carotid arteries were cannulated for BP measurement, blood removal, and drug administration. It was found that L-alanine, in doses of 10, 25, 50, 100, and 200 mg/kg, increased the systolic BP of hypotensive rats by 38 to 80 percent (while 100 mg/kg pyruvate increased BP by only 9.4 mmhg, not significantly different from saline). The results suggest that L-alanine might influence cardiovascular function.

Patterns of Relationships between Cardiovascular Disease Risk Factors and Neurocognitive Function in African Americans

PubMed Central

Sims, Regina; Madhere, Serge; Callender, Clive; Campbell, Alfonso

2013-01-01

Objective The association between cardiovascular disease (CVD) risk and neurocognitive function has gathered a good deal of attention in the health and social science literature; however, the relationship among several CVD risk factors and neurocognitive function has not been fully explored in an African American sample. The purpose of this study was to examine the pattern of relationships among four CVD risk factors and five measures of higher cortical functions. Methods Data were collected from a sample of 106 African American community-dwelling adults in the metropolitan Washington, DC, area. A nurse collected blood pressure, waist circumference, and a blood sample (to assess triglycerides and high-density lipoprotein (HDL) cholesterol) from study participants. Participants completed the Symbol Digit Modalities Test, Trailmaking B, Stroop Colorword Task, California Verbal Learning Test-II, and Wisconsin Card Sorting Test as assessments of neurocognitive function. Canonical analysis and multiple regression analysis were the major statistical methods utilized to assess relationships between CVD risk factors and neurocognitive function. Results The results suggest that 1) attentional processes are associated with diastolic blood pressure levels, 2) verbal learning processes are associated with diastolic blood pressure and triglyceride levels, and 3) the ability to shift cognitive set is associated with HDL cholesterol levels. Conclusion As cardiovascular health worsens in our society, particularly among ethnic minorities, the neurocognitive consequences must be clearly understood. Future studies should focus on identifying and building awareness of cardiovascular and neurocognitive links through longitudinal research designs and brain imaging technology. PMID:19157252

Regulation of blood pressure and renal function by NCC and ENaC: lessons from genetically engineered mice.

PubMed

Verouti, Sophia N; Boscardin, Emilie; Hummler, Edith; Frateschi, Simona

2015-04-01

The activity of the thiazide-sensitive Na(+)/Cl(-) cotransporter (NCC) and of the amiloride-sensitive epithelial Na(+) channel (ENaC) is pivotal for blood pressure regulation. NCC is responsible for Na(+) reabsorption in the distal convoluted tubule (DCT) of the nephron, while ENaC reabsorbs the filtered Na(+) in the late DCT and in the cortical collecting ducts (CCD) providing the final renal adjustment to Na(+) balance. Here, we aim to highlight the recent advances made using transgenic mouse models towards the understanding of the regulation of NCC and ENaC function relevant to the control of sodium balance and blood pressure. We thus like to pave the way for common mechanisms regulating these two sodium-transporting proteins and their potential implication in structural remodeling of the nephron segments and Na(+) and Cl(-) reabsorption. Copyright © 2015 Elsevier Ltd. All rights reserved.

An underwater blood pressure measuring device.

PubMed

Sieber, Arne; Kuch, Benjamin; L'abbate, Antonio; Wagner, Matthias; Dario, Paolo; Bedini, Remo

2008-09-01

Measurement of arterial blood pressure is an important vital sign for monitoring the circulation. However, up to now no instrument has been available that enables the measurement of blood pressure underwater. The present paper details a novel, oscillometric, automatic digital blood pressure (BP) measurement device especially designed for this purpose. It consists mainly of analogue and digital electronics in a lexan housing that is rated to a depth of up to 200 metres' sea water, a cuff and a solenoid for inflation of the cuff with air supplied from a scuba tank. An integrated differential pressure sensor, exposed to the same ambient pressure as the cuff, allows accurate BP measurement. Calculation of systolic and diastolic pressures is based on the analysis of pressure oscillations recorded during the deflation. In hyperbaric chamber tests to pressures up to 405 kPa, BP measurements taken with the prototype were comparable to those obtained with established manual and automated methods. Swimming pool tests confirmed the correct functioning of the system underwater. The quality of the recorded pressure oscillations was very good even at 10 metres' fresh water, and allowed determination of diastolic and systolic pressure values. Based on these results we envisage that this device will lead to a better understanding of human cardiovascular physiology in underwater and hyperbaric environments.

Aldosterone, cognitive function, and cerebral hemodynamics in hypertension and antihypertensive therapy.

PubMed

Hajjar, Ihab; Hart, Meaghan; Mack, Wendy; Lipsitz, Lewis A

2015-03-01

Animal studies suggest that the renin-angiotensin-aldosterone system is involved in neurocognitive function and the response to antihypertensive therapy. We investigated the impact of circulating aldosterone and renin activity on cognition and cerebral hemodynamics at baseline and after antihypertensive therapy for 1 year. Participants were older adults (n = 47; mean age = 71 years) enrolled in a clinical trial. Routine antihypertensive medications were replaced with the study regimen to achieve a blood pressure <140/90 mm Hg. Executive function, memory, cerebral hemodynamics (blood flow velocity), CO2 vasoreactivity (measured using transcranial Doppler ultrasonography), plasma renin activity, and aldosterone were measured at baseline and at 6 and 12 months after the initiation of treatment. At baseline, higher levels of circulating aldosterone were associated with lower blood flow velocity (β = -0.02; P = 0.03), lower CO2 vasoreactivity (β = -0.11; P = 0.007), and decreased autoregulation abilities (β = -0.09; P = 0.01). Those with higher levels of aldosterone at baseline demonstrated the greatest improvement in executive function (P = 0.014 for the aldosterone effect) and in CO2 vasoreactivity (P = 0.026 for the aldosterone effect) after 12 months of lowering blood pressure (<140/90 mm Hg). Plasma renin activity was not associated with any of the measures. Higher levels of aldosterone may be associated with decreased cerebrovascular function in hypertension. Those with higher aldosterone levels may benefit the most from lowering blood pressure. The role of aldosterone in brain health warrants further investigation in a larger trial. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Aldosterone, Cognitive Function, and Cerebral Hemodynamics in Hypertension and Antihypertensive Therapy

PubMed Central

Hart, Meaghan; Mack, Wendy; Lipsitz, Lewis A.

2015-01-01

BACKGROUND Animal studies suggest that the renin–angiotensin–aldosterone system is involved in neurocognitive function and the response to antihypertensive therapy. We investigated the impact of circulating aldosterone and renin activity on cognition and cerebral hemodynamics at baseline and after antihypertensive therapy for 1 year. METHODS Participants were older adults (n = 47; mean age = 71 years) enrolled in a clinical trial. Routine antihypertensive medications were replaced with the study regimen to achieve a blood pressure <140/90mm Hg. Executive function, memory, cerebral hemodynamics (blood flow velocity), CO2 vasoreactivity (measured using transcranial Doppler ultrasonography), plasma renin activity, and aldosterone were measured at baseline and at 6 and 12 months after the initiation of treatment. RESULTS At baseline, higher levels of circulating aldosterone were associated with lower blood flow velocity (β = −0.02; P = 0.03), lower CO2 vasoreactivity (β = −0.11; P = 0.007), and decreased autoregulation abilities (β = −0.09; P = 0.01). Those with higher levels of aldosterone at baseline demonstrated the greatest improvement in executive function (P = 0.014 for the aldosterone effect) and in CO2 vasoreactivity (P = 0.026 for the aldosterone effect) after 12 months of lowering blood pressure (<140/90mm Hg). Plasma renin activity was not associated with any of the measures. CONCLUSIONS Higher levels of aldosterone may be associated with decreased cerebrovascular function in hypertension. Those with higher aldosterone levels may benefit the most from lowering blood pressure. The role of aldosterone in brain health warrants further investigation in a larger trial. PMID:25213687

Dark chocolate and reduced snack consumption in mildly hypertensive adults: an intervention study.

PubMed

Koli, Raika; Köhler, Klaus; Tonteri, Elina; Peltonen, Juha; Tikkanen, Heikki; Fogelholm, Mikael

2015-08-22

Several studies have shown that cocoa and cocoa-containing foods have the potential to lower blood pressure and improve endothelial function. Most of the studies reporting the beneficial effects of dark chocolate on blood pressure have been short (≤ 4 weeks). The aim of the present 8-wks (weeks) study was to assess the effects of regular consumption of dark chocolate during a reduced snack consumption intervention on blood pressure and other cardiovascular risk factors in mildly hypertensive individuals. This was a randomized, controlled, cross-over trial involving 22 adults (8 women, 14 men), aged 33-64 y, BMI 27.7 ± 3.7 kg/m(2) with mild hypertension. During the intervention period (8-wks) the participants reduced the intake of habitual snacks and replaced them with dark chocolate (49 g/day). In the control period, they only reduced the snacks without any added chocolate. Data (blood lipid profile, glucose, insulin, 24 h blood pressure) was collected in the beginning and end of both periods (intervention and control), and some variables also in the run-in and run-out periods (weight, body fat percentage, blood pressure, arterial stiffness index, diet and physical activity). Daily consumption of dark chocolate had no effects on 24 h blood pressure, resting blood pressure (mean ± SD, pre 142 ± 11.5/89 ± 8.4 mmHg vs. post 142 ± 14.2/88 ± 9.4 mmHg in systolic and diastolic blood pressure, respectively) or arterial stiffness (mean ± SD, pre 7.68 ± 0.88 vs. post 7.76 ± 0.89). Weight was reduced by 1.0 ± 2.2 kg during the control (reduced snack only) period, but was unchanged while eating chocolate (p < 0.027 between the treatments). The data collected in this study indicates that inclusion of dark chocolate daily in the diet had no significant effects on blood pressure or other cardiovascular risk factors during a reduced snack period. ClinicalTrials.gov identifier NCT02130141.

Systolic hypertension: an increasing clinical challenge in Asia

PubMed Central

Park, Jeong Bae; Kario, Kazuomi; Wang, Ji-Guang

2015-01-01

Systolic hypertension, the predominant form of hypertension in patients aged over 50–60 years, is a growing health issue as the Asian population ages. Elevated systolic blood pressure is mainly caused by arterial stiffening, resulting from age-related vascular changes. Elevated systolic pressure increases the risk of cardiovascular disease, mortality and renal function decline, and this risk may increase at lower systolic pressure levels in Asian than Western subjects. Hence, effective systolic pressure lowering is particularly important in Asians yet blood pressure control remains inadequate despite the availability of numerous antihypertensive medications. Reasons for poor blood pressure control include low awareness of hypertension among health-care professionals and patients, under-treatment, and tolerability problems with antihypertensive drugs. Current antihypertensive treatments also lack effects on the underlying vascular pathology of systolic hypertension, so novel drugs that address the pathophysiology of arterial stiffening are needed for optimal management of systolic hypertension and its cardiovascular complications. PMID:25503845

Left ventricular morphology and diastolic function in uraemia: echocardiographic evidence of a specific cardiomyopathy.

PubMed Central

Facchin, L.; Vescovo, G.; Levedianos, G.; Zannini, L.; Nordio, M.; Lorenzi, S.; Caturelli, G.; Ambrosio, G. B.

1995-01-01

OBJECTIVE--To see whether cardiac morphological and functional abnormalities in uraemic patients are determined by high blood pressure or if they are an expression of a specific cardiomyopathy. DESIGN--Cross sectional study. SETTING--City general hospital in Italy. SUBJECTS--35 uraemic patients receiving haemodialysis (17 men, 18 women; mean age 60.3 (11.2); mean duration of dialysis 52 months) were selected from the 64 patients in Venice who were receiving dialysis; subjects with diabetes, haemochromatosis, valvar dysfunction, regional dyskinesias, and pericarditis were excluded. 19 control normotensive subjects (6 men and 13 women), matched for age. MAIN OUTCOME MEASURES--Echocardiographic measurements of left atrium, left ventricular end diastolic and end systolic volume, aortic root diameter, posterior wall and interventricular septum thickness, left ventricle mass index, and ejection fraction in controls and in patients according to whether they were normotensive (five men, eight women) or hypertensive (12 men, 10 women) on 48 hour ambulatory monitoring; left ventricular diastolic function by Doppler ultrasonography. RESULTS--Mean systolic and diastolic pressures, daytime systolic and diastolic pressures, and night time systolic and diastolic pressures were significantly higher in the hypertensive patients than in the normotensive patients. The normotensive patients had similar blood pressures to the controls. Left ventricular mass correlated significantly with the mean diastolic pressure and mean night time systolic and diastolic pressures. Parathyroid hormone concentrations were similar in the two groups of patients. Diastolic relaxation was impaired to the same degree in the two groups of patients. Parameters of diastolic function showed no relation to left ventricular mass, which was significantly higher in the hypertensive than in the normotensive patients. CONCLUSIONS--Uraemia is likely to induce specific changes in the relaxation properties of the myocardium. These changes are responsible for the impaired diastolic function independently of blood pressure, degree of hypertrophy, and metabolic changes, which suggests the existence of a specific cardiomyopathy. Hypertension remains a determinant of left ventricular mass. PMID:7546998

Virgin Coconut Oil Prevents Blood Pressure Elevation and Improves Endothelial Functions in Rats Fed with Repeatedly Heated Palm Oil

PubMed Central

Nurul-Iman, Badlishah Sham; Kamisah, Yusof; Jaarin, Kamsiah; Qodriyah, Hj Mohd Saad

2013-01-01

This study was performed to explore the effects of virgin coconut oil (VCO) in male rats that were fed with repeatedly heated palm oil on blood pressure, plasma nitric oxide level, and vascular reactivity. Thirty-two male Sprague-Dawley rats were divided into four groups: (i) control (basal diet), (ii) VCO (1.42 mL/kg, oral), (iii) five-times-heated palm oil (15%) (5HPO), and (iv) five-times-heated palm oil (15%) and VCO (1.42 mL/kg, oral) (5HPO + VCO). Blood pressure was significantly increased in the group that was given the 5HPO diet compared to the control group. Blood pressure in the 5HPO + VCO group was significantly lower than the 5HPO group. Plasma nitric oxide (NO) level in the 5HPO group was significantly lower compared to the control group, whereas in the 5HPO + VCO group, the plasma NO level was significantly higher compared to the 5HPO group. Aortic rings from the 5HPO group exhibited attenuated relaxation in response to acetylcholine and sodium nitroprusside as well as increased vasoconstriction to phenylephrine compared to the control group. Aortic rings from the 5HPO + VCO group showed only attenuated vasoconstriction to phenylephrine compared to the 5HPO group. In conclusion, VCO prevents blood pressure elevation and improves endothelial functions in rats fed with repeatedly heated palm oil. PMID:23861707

Virgin coconut oil prevents blood pressure elevation and improves endothelial functions in rats fed with repeatedly heated palm oil.

PubMed

Nurul-Iman, Badlishah Sham; Kamisah, Yusof; Jaarin, Kamsiah; Qodriyah, Hj Mohd Saad

2013-01-01

This study was performed to explore the effects of virgin coconut oil (VCO) in male rats that were fed with repeatedly heated palm oil on blood pressure, plasma nitric oxide level, and vascular reactivity. Thirty-two male Sprague-Dawley rats were divided into four groups: (i) control (basal diet), (ii) VCO (1.42 mL/kg, oral), (iii) five-times-heated palm oil (15%) (5HPO), and (iv) five-times-heated palm oil (15%) and VCO (1.42 mL/kg, oral) (5HPO + VCO). Blood pressure was significantly increased in the group that was given the 5HPO diet compared to the control group. Blood pressure in the 5HPO + VCO group was significantly lower than the 5HPO group. Plasma nitric oxide (NO) level in the 5HPO group was significantly lower compared to the control group, whereas in the 5HPO + VCO group, the plasma NO level was significantly higher compared to the 5HPO group. Aortic rings from the 5HPO group exhibited attenuated relaxation in response to acetylcholine and sodium nitroprusside as well as increased vasoconstriction to phenylephrine compared to the control group. Aortic rings from the 5HPO + VCO group showed only attenuated vasoconstriction to phenylephrine compared to the 5HPO group. In conclusion, VCO prevents blood pressure elevation and improves endothelial functions in rats fed with repeatedly heated palm oil.

Renal intercalated cells and blood pressure regulation

PubMed Central

Wall, Susan M.

2017-01-01

Type B and non-A, non-B intercalated cells are found within the connecting tubule and the cortical collecting duct. Of these cell types, type B intercalated cells are known to mediate Cl− absorption and HCO3− secretion largely through pendrin-dependent Cl−/HCO3− exchange. This exchange is stimulated by angiotensin II administration and is also stimulated in models of metabolic alkalosis, for instance after aldosterone or NaHCO3 administration. In some rodent models, pendrin-mediated HCO3− secretion modulates acid-base balance. However, the role of pendrin in blood pressure regulation is likely of more physiological or clinical significance. Pendrin regulates blood pressure not only by mediating aldosterone-sensitive Cl− absorption, but also by modulating the aldosterone response for epithelial Na+ channel (ENaC)-mediated Na+ absorption. Pendrin regulates ENaC through changes in open channel of probability, channel surface density, and channels subunit total protein abundance. Thus, aldosterone stimulates ENaC activity through both direct and indirect effects, the latter occurring through its stimulation of pendrin expression and function. Therefore, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contributory role of pendrin in distal nephron function and blood pressure. PMID:29285423

Relationship Between 24-Hour Ambulatory Blood Pressure and Cognitive Function in Community-Living Older Adults: The UCSD Ambulatory Blood Pressure Study.

PubMed

Conway, Kyle S; Forbang, Nketi; Beben, Tomasz; Criqui, Michael H; Ix, Joachim H; Rifkin, Dena E

2015-12-01

Twenty-four-hour ambulatory blood pressure (BP) patterns have been associated with diminished cognitive function in hypertensive and very elderly populations. The relationship between ambulatory BP patterns and cognitive function in community-living older adults is unknown. We conducted a cross-sectional study in which 24-hour ambulatory BP, in-clinic BP, and cognitive function measures were obtained from 319 community-living older adults. The mean age was 72 years, 66% were female, and 13% were African-American. We performed linear regression with performance on the Montreal Cognitive Assessment (MoCA) as the primary outcome and 24-hour BP patterns as the independent variable, adjusting for age, sex, race/ethnicity, education, and comorbidities. Greater nighttime systolic dipping (P = 0.046) and higher 24-hour diastolic BP (DBP; P = 0.015) were both significantly associated with better cognitive function, whereas 24-hour systolic BP (SBP), average real variability, and ambulatory arterial stiffness were not. Higher 24-hour DBP and greater nighttime systolic dipping were significantly associated with improved cognitive function. Future studies should examine whether low 24-hour DBP and lack of nighttime systolic dipping predict future cognitive impairment. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The relationship between training status, blood pressure and uric acid in adults and elderly.

PubMed

Trapé, Atila Alexandre; Jacomini, André Mourão; Muniz, Jaqueline Jóice; Sertorio, Jonas Tadeu Cau; Tanus-Santos, José Eduardo; do Amaral, Sandra Lia; Zago, Anderson Saranz

2013-06-21

Hypertension can be generated by a great number of mechanisms including elevated uric acid (UA) that contribute to the anion superoxide production. However, physical exercise is recommended to prevent and/or control high blood pressure (BP). The purpose of this study was to investigate the relationship between BP and UA and whether this relationship may be mediated by the functional fitness index. All participants (n = 123) performed the following tests: indirect maximal oxygen uptake (VO2max), AAHPERD Functional Fitness Battery Test to determine the general fitness functional index (GFFI), systolic and diastolic blood pressure (SBP and DBP), body mass index (BMI) and blood sample collection to evaluate the total-cholesterol (CHOL), LDL-cholesterol (LDL-c), HDL-cholesterol (HDL-c), triglycerides (TG), uric acid (UA), nitrite (NO2) and thiobarbituric acid reactive substances (T-BARS). After the physical, hemodynamic and metabolic evaluations, all participants were allocated into three groups according to their GFFI: G1 (regular), G2 (good) and G3 (very good). Baseline blood pressure was higher in G1 when compared to G3 (+12% and +11%, for SBP and DBP, respectively, p<0.05) and the subjects who had higher values of BP also presented higher values of UA. Although UA was not different among GFFI groups, it presented a significant correlation with GFFI and VO2max. Also, nitrite concentration was elevated in G3 compared to G1 (140±29 μM vs 111±29 μM, for G3 and G1, respectively, p<0.0001). As far as the lipid profile, participants in G3 presented better values of CHOL and TG when compared to those in G1. Taking together the findings that subjects with higher BP had elevated values of UA and lower values of nitrite, it can be suggested that the relationship between blood pressure and the oxidative stress produced by uric acid may be mediated by training status.

Effect of Angiotensin-Converting Enzyme Inhibitor/Calcium Antagonist Combination Therapy on Renal Function in Hypertensive Patients With Chronic Kidney Disease: Chikushi Anti-Hypertension Trial - Benidipine and Perindopril.

PubMed

Okuda, Tetsu; Okamura, Keisuke; Shirai, Kazuyuki; Urata, Hidenori

2018-02-01

Appropriate blood pressure control suppresses progression of chronic kidney disease (CKD). If an angiotensin-converting enzyme (ACE) inhibitor is ineffective, adding a calcium antagonist is recommended. We compared the long-term effect of two ACE inhibitor/calcium antagonist combinations on renal function in hypertensive patients with CKD. Patients who failed to achieve the target blood pressure (systolic/diastolic: < 130/80 mm Hg) with perindopril monotherapy were randomized to either combined therapy with perindopril and the L-type calcium antagonist amlodipine (group A) or perindopril and the T/L type calcium antagonist benidipine (group B). The primary endpoint was the change of the estimated glomerular filtration rate (eGFR) after 2 years. Eligible patients had a systolic pressure ≥ 130 mm Hg and/or diastolic pressure ≥ 80 mm Hg and CKD (urine protein (+) or higher, eGFR < 60 min/mL/1.73 m 2 ). After excluding 38 patients achieving the target blood pressure with perindopril monotherapy, 121 patients were analyzed (62 in group A and 59 in group B). Blood pressure decreased significantly in both groups, but there was no significant change of the eGFR. However, among patients with diabetes, eGFR unchanged in group B (n = 37, 59.1 ± 15.1 vs. 61.2 ± 27.9, P = 0.273), whereas decreased significantly in group A (n = 31, 57.3 ± 16.0 vs. 53.7 ± 16.7, P = 0.005). In hypertensive patients with diabetic nephropathy, combined therapy with an ACE inhibitor and T/L type calcium antagonist may prevent deterioration of renal function more effectively than an ACE inhibitor/L type calcium antagonist combination.

Neural control of vascular reactions: impact of emotion and attention.

PubMed

Okon-Singer, Hadas; Mehnert, Jan; Hoyer, Jana; Hellrung, Lydia; Schaare, Herma Lina; Dukart, Juergen; Villringer, Arno

2014-03-19

This study investigated the neural regions involved in blood pressure reactions to negative stimuli and their possible modulation by attention. Twenty-four healthy human subjects (11 females; age = 24.75 ± 2.49 years) participated in an affective perceptual load task that manipulated attention to negative/neutral distractor pictures. fMRI data were collected simultaneously with continuous recording of peripheral arterial blood pressure. A parametric modulation analysis examined the impact of attention and emotion on the relation between neural activation and blood pressure reactivity during the task. When attention was available for processing the distractor pictures, negative pictures resulted in behavioral interference, neural activation in brain regions previously related to emotion, a transient decrease of blood pressure, and a positive correlation between blood pressure response and activation in a network including prefrontal and parietal regions, the amygdala, caudate, and mid-brain. These effects were modulated by attention; behavioral and neural responses to highly negative distractor pictures (compared with neutral pictures) were smaller or diminished, as was the negative blood pressure response when the central task involved high perceptual load. Furthermore, comparing high and low load revealed enhanced activation in frontoparietal regions implicated in attention control. Our results fit theories emphasizing the role of attention in the control of behavioral and neural reactions to irrelevant emotional distracting information. Our findings furthermore extend the function of attention to the control of autonomous reactions associated with negative emotions by showing altered blood pressure reactions to emotional stimuli, the latter being of potential clinical relevance.

Emotional dampening in persons with elevated blood pressure: affect dysregulation and risk for hypertension.

PubMed

McCubbin, James A; Loveless, James P; Graham, Jack G; Hall, Gabrielle A; Bart, Ryan M; Moore, DeWayne D; Merritt, Marcellus M; Lane, Richard D; Thayer, Julian F

2014-02-01

Persons with higher blood pressure have emotional dampening in some contexts. This may reflect interactive changes in central nervous system control of affect and autonomic function in the early stages of hypertension development. The purpose of this study is to determine the independence of cardiovascular emotional dampening from alexithymia to better understand the role of affect dysregulation in blood pressure elevations. Ninety-six normotensives were assessed for resting systolic and diastolic (DBP) blood pressure, recognition of emotions in faces and sentences using the Perception of Affect Task (PAT), alexithymia, anxiety, and defensiveness. Resting DBP significantly predicted PAT emotion recognition accuracy in men after adjustment for age, self-reported affect, and alexithymia. Cardiovascular emotional dampening is independent of alexithymia and affect in men. Dampened emotion recognition could potentially influence interpersonal communication and psychosocial distress, thereby further contributing to BP dysregulation and increased cardiovascular risk.

Dynamic cerebral autoregulation in stroke patients with a central sympathetic deficit.

PubMed

Gierthmühlen, J; Allardt, A; Sawade, M; Baron, R; Wasner, G

2011-05-01

To investigate the functional role of the sympathetic innervation on cerebral autoregulation. Seventeen patients with infarction of the dorsolateral medulla oblongata affecting central sympathetic pathways (Wallenberg's syndrome) and 21 healthy controls were included in the study. Cerebral blood flow velocity (CBFV) in the medial cerebral artery was investigated using transcranial Doppler ultrasound during decrease in cerebral perfusion pressure induced by leg-cuff test and tilt table. Upon leg-cuff test, changes of cerebral blood flow and mean arterial blood pressure as well as autoregulatory index did not differ between patients or controls. No differences were found in changes of CBFV, mean arterial blood pressure and heart rate between patients or controls during the tilt table test. We suggest that the sympathetic nervous system does not have an influence on cerebral autoregulation after decrease in perfusion pressure under normotonous conditions. © 2010 John Wiley & Sons A/S.

Dietary Sodium and Health: More Than Just Blood Pressure

PubMed Central

Farquhar, William B.; Edwards, David G.; Jurkovitz, Claudine T.; Weintraub, William S.

2016-01-01

Sodium is essential for cellular homeostasis and physiological function. Excess dietary sodium has been linked to elevations in blood pressure (BP). Salt-sensitivity of BP varies widely, but certain subgroups tend to be more salt-sensitive. The mechanisms underlying sodium-induced increases in BP are not completely understood, but may involve alterations in renal function, fluid volume, fluid regulatory hormones, the vasculature, cardiac function, and the autonomic nervous system. Recent pre-clinical and clinical data support that even in the absence of an increase in BP, excess dietary sodium can adversely affect target organs, including the blood vessels, heart, kidneys, and brain. In this review, we address these issues and the epidemiological literature relating dietary sodium to BP and cardiovascular health outcomes, addressing recent controversies. We also provide information and strategies for reducing dietary sodium. PMID:25766952

The influence of tobacco smoking on the relationship between pressure and flow in the middle cerebral artery in humans.

PubMed

Peebles, Karen C; Horsman, Helen; Tzeng, Yu-Chieh

2013-01-01

Cigarette smoking is associated with an increased risk of stroke but the mechanism is unclear. The study examined whether acute and chronic cigarette smoking alters the dynamic relationship between blood pressure and cerebral blood flow. We hypothesised that acute and chronic smoking would result in a cerebral circulation that was less capable of buffering against dynamic fluctuations in blood pressure. Further, these changes would be accompanied by a reduction in baroreflex sensitivity, which is reduced after smoking (acute smoking). We recruited 17 non-smokers and 15 habitual smokers (13 ± 5 pack years). Continuous measurements of mean cerebral blood flow velocity (transcranial Doppler ultrasound), blood pressure (finger photoplethysmography) and heart rate enabled transfer function analysis of the dynamic relationship between pressure and flow (gain, normalised gain, phase and coherence) and baroreflex sensitivity during supine rest before and after smoking a single cigarette (acute smoking). There were no between-group differences in gain, phase or coherence before acute smoking. However, both groups showed a reduction in gain and coherence, associated with a reduction in baroreflex sensitivity, and increase in phase after acute smoking. Contrary to our hypothesis, these findings suggest that in the face of a reduction in baroreflex sensitivity acute smoking may potentially improve the ability of the cerebral circulation to buffer against changes in blood pressure. However, chronic smoking did not alter the dynamic relationship between blood pressure and cerebral blood flow velocity. These results have implications on understanding mechanisms for attenuating stroke risk.

Challenges in the Management of Hypertension in Older Populations.

PubMed

Pont, Lisa; Alhawassi, Tariq

2017-01-01

The prevalence of hypertension increases with age making it a significant health concern for older persons. Aging involves a range of physiological changes such as increases in arterial stiffness, widening pulse pressure, changes in renin and aldosterone levels, decreases in renal salt excretion, declining in renal function, changes in the autonomic nervous system sensitivity and function and changes to endothelial function all of which may not only affect blood pressure but may also affect individual response to pharmacotherapy used to manage hypertension and prevent end organ damage and other complications associated with poor blood pressure control.Unlike many chronic conditions where there is limited evidence for management in older populations, there is good evidence regarding the management of hypertension in the elderly. The findings from multiple large, robust trials have provided a solid evidence-base regarding the management of hypertension in older adults, showing that reduction of blood pressure in older hypertensive populations is associated with reduced mortality and morbidity. Diuretics, agents action on the renin angiotensin system, beta blockers and calcium channel blockers have all been well studied in older populations both in view of the benefits associated with blood pressure lowering and the risks associated with associated adverse events. While all antihypertensive agents will lower blood pressure, when managing hypertension in older persons the choice of agent is dependent not only on the ability to lower blood pressure but also on the potential for harm with older persons. Understanding such potential harms in older populations is essential with older persons experiencing increased sensitivity to many of the adverse effects such as dizziness associated with the use of antihypertensive agents.Despite the wealth of evidence regarding the benefits of managing hypertension in the old and very old, a significant proportion of older individuals with hypertension have suboptimal BP control. While there is good evidence supporting blood pressure lowering in older antihypertensive agents, these have not yet been optimally translated fully into clinical guidelines and clinical practice. There appear to be considerable differences between guidelines in terms of the guidance given to clinicians. Differences in interpretation of the evidence, as well as differences in study design and populations all contribute to differences in the guideline recommendations with respect to older populations, despite the strength of the underlying scientific evidence. Differences around who is considered "old" and what BP targets and management are considered appropriate may lead to confusion among clinicians and further contribute to the evidence-practice lag.

Cardiopulmonary and Metabolic Effects of Yoga in Healthy Volunteers

PubMed Central

Divya, T Satheesh; Vijayalakshmi, MT; Mini, K; Asish, K; Pushpalatha, M; Suresh, Varun

2017-01-01

Background: Yoga the spiritual union of mind with the divine intelligence of the universe aims to liberate a human being from conflicts of body–mind duality. Beneficial cardiovascular and pulmonary effects of yoga are in par with aerobic exercise, even amounting to replace the exercise model. We conducted an interventional study in healthy volunteers, to analyze the impact of short-term yoga training on cardiovascular, pulmonary, autonomic function tests, lipid profile, and thyroid function tests. Materials and Methods: A sample of fifty new recruits attending the district yoga center was subject to 75 min yoga practice a day for 41 days. Basal values of cardiovascular, pulmonary, autonomic function tests, lipid profile, and thyroid function tests were recorded before yoga training and were reassessed for postyoga changes after 41 days. Results: After yoga practice there was a significant reduction in the resting heart rate, systolic blood pressure, diastolic blood pressure, and mean blood pressure of the participants. Effects on autonomic function tests were variable and inconclusive. There was a significant increase in forced vital capacity, forced expiratory volume in 1 s, and peak expiratory flow rate after yoga. A significant reduction in body mass index was observed. Effects on metabolic parameters were promising with a significant reduction in fasting blood sugar level, serum total cholesterol, serum triglycerides serum low-density lipoprotein levels, and significant increase in high-density lipoprotein. There was no significant change in thyroid function tests after yoga. Conclusion: Short-term yoga practice has no effect on thyroid functions. Yoga practice was found beneficial in maintaining physiological milieu pertaining to cardiovascular and other metabolic parameters. PMID:29422741

Cardiopulmonary and Metabolic Effects of Yoga in Healthy Volunteers.

PubMed

Divya, T Satheesh; Vijayalakshmi, M T; Mini, K; Asish, K; Pushpalatha, M; Suresh, Varun

2017-01-01

Yoga the spiritual union of mind with the divine intelligence of the universe aims to liberate a human being from conflicts of body-mind duality. Beneficial cardiovascular and pulmonary effects of yoga are in par with aerobic exercise, even amounting to replace the exercise model. We conducted an interventional study in healthy volunteers, to analyze the impact of short-term yoga training on cardiovascular, pulmonary, autonomic function tests, lipid profile, and thyroid function tests. A sample of fifty new recruits attending the district yoga center was subject to 75 min yoga practice a day for 41 days. Basal values of cardiovascular, pulmonary, autonomic function tests, lipid profile, and thyroid function tests were recorded before yoga training and were reassessed for postyoga changes after 41 days. After yoga practice there was a significant reduction in the resting heart rate, systolic blood pressure, diastolic blood pressure, and mean blood pressure of the participants. Effects on autonomic function tests were variable and inconclusive. There was a significant increase in forced vital capacity, forced expiratory volume in 1 s, and peak expiratory flow rate after yoga. A significant reduction in body mass index was observed. Effects on metabolic parameters were promising with a significant reduction in fasting blood sugar level, serum total cholesterol, serum triglycerides serum low-density lipoprotein levels, and significant increase in high-density lipoprotein. There was no significant change in thyroid function tests after yoga. Short-term yoga practice has no effect on thyroid functions. Yoga practice was found beneficial in maintaining physiological milieu pertaining to cardiovascular and other metabolic parameters.

Acute air pollution exposure and blood pressure at delivery among women with and without hypertension.

PubMed

Männistö, Tuija; Mendola, Pauline; Liu, Danping; Leishear, Kira; Sherman, Seth; Laughon, S Katherine

2015-01-01

Chronic air pollution exposure increases risk for hypertensive disorders of pregnancy, but the effect of acute air pollution exposure on blood pressure during pregnancy is less well known. We studied 151,276 singleton term deliveries from the Consortium on Safe Labor (2002-2008) with clinical blood pressure measured at admission to labor/delivery and diagnoses of hypertensive disorders collected from electronic medical records and hospital discharge summaries. Air pollution exposures were estimated for the admission hour and the 4 hours preceding admission using a modified version of the Community Multiscale Air Quality models and observed air monitoring data. Blood pressure was categorized as normal; high normal; and mild, moderate, or severe hypertension based on pregnancy cut points. Adjusted ordinal logistic regression estimated the odds of women having a higher admission blood pressure category as a function of air pollutant, hypertensive disorders, and their interaction effect. Odds of high blood pressure at admission to labor/delivery were increased in normotensive women after exposure to nitrogen oxides (by 0.2%/5 units), sulfur dioxide (by 0.3%/1 unit), carbon monoxide and several air toxics (by 3%-4%/high exposure). The effects were often similar or stronger among women with gestational hypertension and preeclampsia. Exposure to particulate matter <10 μm increased odds of high blood pressure in women with preeclampsia by 3%/5 units. Air pollution can influence admission blood pressure in term deliveries and may increase likelihood of preeclampsia screening at delivery admission. © Published by Oxford University Press on behalf of American Journal of Hypertension Ltd 2014. This work is written by (a) US Government employees(s) and is in the public domain in the US.

Left ventricular mass predicted by a single reading of ambulatory blood pressure in essential hypertension.

PubMed

Ohmori, S; Matsumura, K; Kajioka, T; Fukuhara, M; Abe, I; Fujishima, M

2000-07-01

The spectral power of heart rate variability has been shown to be negatively correlated with left ventricular mass (LVM), suggesting the contribution of left ventricular hypertrophy to autonomic dysfunction in essential hypertension. However, a simultaneous assessment of autonomic function and ambulatory blood pressure in relation to LVM has not been carried out. The objective of the present study was to elucidate the synergistic effects of ambulatory blood pressure and autonomic nerve activity on the heart. We enrolled 25 ambulant patients with untreated essential hypertension (9 men and 16 women; mean age 50.6 +/- 2.0 years). The ambulatory blood pressure and heart rate variability were simultaneously monitored every 30 min for 24 h. The spectral power of high-frequency (HF: 0.15 to 0.4 Hz) and low-frequency (LF: 0.05 to 0.15 Hz) bands were measured, and the ratio of LF to HF (LF/HF) was calculated. LF/HF and HF were used as indexes of sympathetic and parasympathetic activities, respectively. LVM was determined by echocardiography. Both the average daytime and nighttime systolic ambulatory blood pressures significantly correlated with the LVM index (r= 0.644, p< 0.001; and r= 0.428, p< 0.05; respectively), although there was no such correlation with the clinic blood pressures. In contrast, a single reading of ambulatory systolic blood pressure measured when LF/HF reached a maximum value was significantly correlated with the LVM index independently of age and sex (partial r= 0.484, p< 0.05). These results suggest that the ambulatory systolic blood pressure during increases in the activity of the sympathetic nervous system is able to infer LVM in essential hypertension.

Cardiovascular Responses to Sexual Activity in Able-Bodied Individuals and Those Living with Spinal Cord Injury.

PubMed

Davidson, Ross; Elliott, Stacy; Krassioukov, Andrei

2016-12-15

Sexuality is an integral part of the human experience and persists in health and disability. The cardiovascular system is crucial to sexual function and can be affected profoundly by spinal cord injury (SCI). The effects of sexual activity on the cardiovascular system in SCI have not been summarized and compared with sexual activity in able-bodied individuals. A keyword search of Embase, PubMed, and Medline was conducted. From 471 retrieved studies for able-bodied individuals, 11 were included that met the strict criteria of medically uncomplicated participants. In the SCI literature, 117 studies were screened, with 18 meeting criteria. In able-bodied persons, sexual activity resulted in modest increases in systolic blood pressure peaking at orgasm (males of 163 mm Hg and females of 142 mm Hg) and returning to baseline shortly afterward. In persons with SCI, results varied from minimal changes to significant elevations in systolic blood pressure because of episodes of autonomic dysreflexia, especially in those with high thoracic and cervical lesions. Peak systolic blood pressure in these individuals was measured to be as high as 325 mm Hg. In the SCI population, more intense stimuli (including penile vibrostimulation and electroejaculation) tended to result in a greater increase in systolic blood pressure compared with self-stimulation. Studies that used continuous versus intermittent monitoring were more likely to report greater changes in systolic blood pressure. In able-bodied persons, sexual activity results in modest increases in blood pressure. In those with SCI, intense stimulation and higher injury levels result in a higher likelihood of autonomic dysreflexia and elevated blood pressure. Because of rapid changes in blood pressure, continuous monitoring is more advantageous than intermittent measurement, because the latter may miss peak values.

Cerebrovascular blood pressure autoregulation monitoring and postoperative transient ischemic attack in pediatric moyamoya vasculopathy.

PubMed

Lee, Jennifer K; Williams, Monica; Reyes, Michael; Ahn, Edward S

2018-02-01

Children with moyamoya vasculopathy are at high risk of perioperative cerebral ischemia or hyperperfusion. Maintaining blood pressure within the range of functional cerebrovascular blood pressure autoregulation might reduce the risk of perioperative neurologic injury. We tested whether blood pressure autoregulation is associated with postoperative transient ischemic attack in a study of patients with pediatric moyamoya vasculopathy. We conducted an observational study of 15 pediatric patients undergoing surgical revascularization with pial synangiosis. Nine patients had bilateral moyamoya and 6 had unilateral moyamoya. We measured autoregulatory vasoreactivity intraoperatively and during the first postoperative night with the hemoglobin volume index, a value derived from near-infrared spectroscopy. We also identified the optimal mean arterial blood pressure at which autoregulation was most robust in each patient. Of the 15 children monitored, 3 with bilateral moyamoya and one with unilateral moyamoya experienced a transient ischemic attack. Poorer autoregulation during surgery was associated with postoperative transient ischemic attack among those with bilateral vasculopathy (P = .048, difference in hemoglobin volume index medians: 0.023, 95% confidence interval: 0.003-0.071). This relationship was not observed with postoperative autoregulation. The optimal mean arterial blood pressure was identifiable during surgery in all monitored patients, varied among patients, and often differed between the intraoperative and postoperative periods. Dysfunctional intraoperative autoregulation may increase the risk of TIA in patients with pediatric moyamoya vasculopathy. The blood pressure range that supports autoregulation appears to vary among patients. Using autoregulation monitoring to guide individualized blood pressure goals should be studied as a potential method to reduce perioperative neurologic morbidity in pediatric patients with moyamoya. © 2017 John Wiley & Sons Ltd.

Angiotensin II, hypertension and angiotensin II receptor antagonism: Roles in the behavioural and brain pathology of a mouse model of Alzheimer's disease.

PubMed

Wiesmann, Maximilian; Roelofs, Monica; van der Lugt, Robert; Heerschap, Arend; Kiliaan, Amanda J; Claassen, Jurgen Ahr

2017-07-01

Elevated angiotensin II causes hypertension and contributes to Alzheimer's disease by affecting cerebral blood flow. Angiotensin II receptor blockers may provide candidates to reduce (vascular) risk factors for Alzheimer's disease. We studied effects of two months of angiotensin II-induced hypertension on systolic blood pressure, and treatment with the angiotensin II receptor blockers, eprosartan mesylate, after one month of induced hypertension in wild-type C57bl/6j and AβPPswe/PS1ΔE9 (AβPP/PS1/Alzheimer's disease) mice. AβPP/PS1 showed higher systolic blood pressure than wild-type. Subsequent eprosartan mesylate treatment restored this elevated systolic blood pressure in all mice. Functional connectivity was decreased in angiotensin II-infused Alzheimer's disease and wild-type mice, and only 12 months of Alzheimer's disease mice showed impaired cerebral blood flow. Only angiotensin II-infused Alzheimer's disease mice exhibited decreased spatial learning in the Morris water maze. Altogether, angiotensin II-induced hypertension not only exacerbated Alzheimer's disease-like pathological changes such as impairment of cerebral blood flow, functional connectivity, and cognition only in Alzheimer's disease model mice, but it also induced decreased functional connectivity in wild-type mice. However, we could not detect hypertension-induced overexpression of Aβ nor increased neuroinflammation. Our findings suggest a link between midlife hypertension, decreased cerebral hemodynamics and connectivity in an Alzheimer's disease mouse model. Eprosartan mesylate treatment restored and beneficially affected cerebral blood flow and connectivity. This model could be used to investigate prevention/treatment strategies in early Alzheimer's disease.

Evaluation of vulnerable PM2.5-exposure individuals: a repeated-measure study in an elderly population.

PubMed

Chu, Haiyan; Xin, Junyi; Yuan, Qi; Zhang, Xu; Pan, Wang; Zeng, Xinying; Chen, Yaoyao; Ma, Gaoxiang; Ge, Yuqiu; Du, Mulong; Tong, Na; Li, Xiaobo; Zhang, Zhengdong; Wang, Meilin

2018-04-01

Numerous studies have shown that elderly people are susceptible to high-level particles with aerodynamic diameter ≤ 2.5 μm (PM 2.5 ) exposure. However, not all elderly people exposed to PM 2.5 suffer from diseases. In this study, we aim to establish a method to predict the vulnerable PM 2.5 -exposure individuals among elderly population. Fourteen elderly people were recruited from May 8 to July 4, 2016, in Nanjing, China. Ten physiological indicators were repeatedly measured for 15 times. Liner mixed-effects model, principal component analysis (PCA), and PM 2.5 lag score were used to estimate the effects of PM 2.5 on blood pressure, pulse, and lung function. As a result, each quartile increase of ambient PM 2.5 was significantly associated with increased pulse (P < 0.05 for lag0, 1, 4, 0-1, 0-2, 0-3, and 0-5 days), decreased blood pressure (P < 0.05 for lag4 and 0-3 days), and decreased lung function (P < 0.05 for lag0, 1, 0-1, and 0-2 days) among the 14 elderly people. In terms of pulse or lung function, three elderly people were considered as vulnerable PM 2.5 -exposure individuals. No vulnerable individual was found for blood pressure. Blood pressure, pulse, and lung function could be affected by high-level PM 2.5 exposure in elderly people. This method for screening three elderly people may provide a new insight on identifying the vulnerable PM 2.5 -exposure individuals.

Protective effects of AT1-receptor blocker and CA antagonist combination on renal function in salt loaded spontaneously hypertensive rats.

PubMed

Gjorgjievska, K; Zafirov, D; Jurhar-Pavlova, M; Cekovska, S; Atanasovska, E; Pavlovska, K; Zendelovska, D

2015-01-01

Salt sensitive hypertension is known to be a contributing factor for the progression of kidney disease. This study was undertaken to investigate the role of excessive dietary salt on renal function and to evaluate the effect of valsartan and amlodipin given as a combination therapy on blood pressure and parameters specific to the renal function in salt loaded SHR rats. 48 male SHR rats at age of 20 weeks and body weight ranging between 270-350 g were used. SHR rats were divided into 3 groups: control group of rats -SHRC (n = 16) given tab water ad libitum and two salt treated groups in which tab water was replaced with a solution of NaCl (1%) from age of 8 weeks given ad libitum: SHRVAL+AMLO group (n = 16) where investigated drugs were administered at a dose of 10 mg/kg/ b.w. (valsartan) and 5 mg/kg/ b.w. (amlodipin) by gavage and SHR NaCl group (n = 16) that received saline in the same volume and the same time intervals as the SHRVAL+AMLO group. For a period of 12 weeks we have investigated the effect of the VAL+AMLO drug combination on systolic blood pressure (SBP), body weight and renal function tests. Salt loading with 1% solution in the SHR NaCl group has lead to significant increase of blood pressure, proteinuria and decrease in creatinine clearance. Combined treatment with AT1 receptor blocker and calcium antagonist has managed to control blood pressure and ameliorated renal damage.

Comparison of Regression Analysis and Transfer Function in Estimating the Parameters of Central Pulse Waves from Brachial Pulse Wave.

PubMed

Chai, Rui; Xu, Li-Sheng; Yao, Yang; Hao, Li-Ling; Qi, Lin

2017-01-01

This study analyzed ascending branch slope (A_slope), dicrotic notch height (Hn), diastolic area (Ad) and systolic area (As) diastolic blood pressure (DBP), systolic blood pressure (SBP), pulse pressure (PP), subendocardial viability ratio (SEVR), waveform parameter (k), stroke volume (SV), cardiac output (CO), and peripheral resistance (RS) of central pulse wave invasively and non-invasively measured. Invasively measured parameters were compared with parameters measured from brachial pulse waves by regression model and transfer function model. Accuracy of parameters estimated by regression and transfer function model, was compared too. Findings showed that k value, central pulse wave and brachial pulse wave parameters invasively measured, correlated positively. Regression model parameters including A_slope, DBP, SEVR, and transfer function model parameters had good consistency with parameters invasively measured. They had same effect of consistency. SBP, PP, SV, and CO could be calculated through the regression model, but their accuracies were worse than that of transfer function model.

Potential implications of dose and diet for the effects of cocoa flavanols on cardiometabolic function.

PubMed

Davison, Kade; Howe, Peter R C

2015-11-18

The metabolic syndrome is a pathological state whereby cardiovascular and metabolic dysfunction coexist and typically progress in a mutual feed-forward manner to further dysfunction and ultimately disease. The health and function of the vascular endothelium is integral in this phenomenon and thus represents a logical target for intervention. Consumption of foods high in cocoa flavanols has demonstrated a capacity to markedly improve endothelial function and key markers of the metabolic syndrome including blood pressure and insulin sensitivity. The typically high energy content of foods containing sufficient doses of cocoa flavanols has caused some reservations around its therapeutic use, but this is dependent upon the particulars of the food matrix used. Further to this, the food matrix appears to influence the dose response curve of cocoa flavanols, particularly on blood pressure, with dark chocolate appearing to be 8 times more effective in systolic blood pressure reduction than a cocoa powder drink for the equivalent dose of flavanol. Cocoa flavanol consumption conclusively demonstrates a positive impact on cardiometabolic function; however, more research is needed to understand how best to consume it to maximize the benefit while avoiding excessive fat and sugar consumption.

[Effects of medullary ischemia on respiratory and blood pressure induced by ligating basilar artery in cat].

PubMed

Zhuang, Xu; Guo, Jun-Xia; Zhang, Cheng-Wu; Zheng, Yu

2003-11-01

Observations on medullary ischemia region, the morphology of neurons and changes of respiration and blood pressure were made, in order to give evidences on how medullary ischemia affects respiration and circulation and give some advices on how to protect from it. Using cats as the experimental animals, the different parts of the basilar artery trunk were ligated. The changes in the density of blood vessels, the morphology of neurons in the brainstem, the electromyogram (EMG) of the diaphragm and the blood pressure of the femoral artery were investigated. The density of blood vessels notably decreased in the medulla after ligating the basilar artery trunk. The ischemic range induced by ligation of the different parts of the basilar artery trunk overlapped, mainly locating in the medulla rostral to the obex. The soma were swelled and the Nissl bodies decreased in some of neurons in the ischemic region of medulla. The duration of inspiration (T1) and expiration (TE) shortened, respiratory frequency (RF) increased, and mean blood pressure (MBP) decreased in the experimental groups (P < 0.05). There is an obvious overlap of the areas in which blood supplied by different parts of the basilar artery trunk. Medullary ischemia can involve in changes of respiration and blood pressure. The ischemic damage of neurons in the medulla might be the structural basis of the changes in the respiratory and circulatory functions.

Multicomponent exercise decreases blood pressure, heart rate and double product in normotensive and hypertensive older patients with high blood pressure.

PubMed

Coelho-Júnior, Hélio José; Asano, Ricardo Yukio; Gonçalvez, Ivan de Oliveira; Brietzke, Cayque; Pires, Flávio Oliveira; Aguiar, Samuel da Silva; Feriani, Daniele Jardim; Caperuto, Erico Chagas; Uchida, Marco Carlos; Rodrigues, Bruno

2018-02-26

The present study aimed to investigate the effects of a 6-month multicomponent exercise program on blood pressure, heart rate, and double product of uncontrolled and controlled normotensive and hypertensive older patients. The study included 183 subjects, 97 normotensives, of which 53 were controlled normotensives (CNS), and 44 uncontrolled normotensives (UNS), as well as 86 hypertensives, of which 43 were controlled hypertensives (CHS), and 43 uncontrolled hypertensives (UHS). Volunteers were recruited and blood pressure and heart rate measurements were made before and after a 6-month multicomponent exercise program. The program of physical exercise was performed twice a week for 26 weeks. The physical exercises program was based on functional and walking exercises. Exercise sessions were performed at moderate intensity. The results indicated that UHS showed a marked decrease in systolic (-8.0mmHg), diastolic (-11.1mmHg), mean (-10.1mmHg), and pulse pressures, heart rate (-6.8bpm), and double product (-1640bpmmmHg), when compared to baseline. Similarly, diastolic (-5.5mmHg) and mean arterial (-4.8mmHg) pressures were significantly decreased in UNS. Concomitantly, significant changes could be observed in the body mass index (-0.9kg/m 2 ; -1.5kg/m 2 ) and waist circumference (-3.3cm; only UHS) of UNS and UHS, which may be associated with the changes observed in blood pressure. In conclusion, the data of the present study indicate that a 6-month multicomponent exercise program may lead to significant reductions in blood pressure, heart rate, and double product of normotensive and hypertensive patients with high blood pressure values. Copyright © 2018 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Longitudinal Assessment of Vascular Function With Sunitinib in Patients With Metastatic Renal Cell Carcinoma.

PubMed

Catino, Anna B; Hubbard, Rebecca A; Chirinos, Julio A; Townsend, Ray; Keefe, Stephen; Haas, Naomi B; Puzanov, Igor; Fang, James C; Agarwal, Neeraj; Hyman, David; Smith, Amanda M; Gordon, Mary; Plappert, Theodore; Englefield, Virginia; Narayan, Vivek; Ewer, Steven; ElAmm, Chantal; Lenihan, Daniel; Ky, Bonnie

2018-03-01

Sunitinib, used widely in metastatic renal cell carcinoma, can result in hypertension, left ventricular dysfunction, and heart failure. However, the relationships between vascular function and cardiac dysfunction with sunitinib are poorly understood. In a multicenter prospective study of 84 metastatic renal cell carcinoma patients, echocardiography, arterial tonometry, and BNP (B-type natriuretic peptide) measures were performed at baseline and at 3.5, 15, and 33 weeks after sunitinib initiation, correlating with sunitinib cycles 1, 3, and 6. Mean change in vascular function parameters and 95% confidence intervals were calculated. Linear regression models were used to estimate associations between vascular function and left ventricular ejection fraction, longitudinal strain, diastolic function (E/e'), and BNP. After 3.5 weeks of sunitinib, mean systolic blood pressure increased by 9.5 mm Hg (95% confidence interval, 2.0-17.1; P =0.02) and diastolic blood pressure by 7.2 mm Hg (95% confidence interval, 4.3-10.0; P <0.001) across all participants. Sunitinib resulted in increases in large artery stiffness (carotid-femoral pulse wave velocity) and resistive load (total peripheral resistance and arterial elastance; all P <0.05) and changes in pulsatile load (total arterial compliance and wave reflection). There were no statistically significant associations between vascular function and systolic dysfunction (left ventricular ejection fraction and longitudinal strain). However, baseline total peripheral resistance, arterial elastance, and aortic impedance were associated with worsening diastolic function and filling pressures over time. In patients with metastatic renal cell carcinoma, sunitinib resulted in early, significant increases in blood pressure, arterial stiffness, and resistive and pulsatile load within 3.5 weeks of treatment. Baseline vascular function parameters were associated with worsening diastolic but not systolic function. © 2018 American Heart Association, Inc.

Cardiovascular effects in rats following exposure to a high-boiling coal liquid.

PubMed

Zangar, R C; Sasser, L B; Mahlum, D D; Abhold, R H; Springer, D L

1987-11-01

In previous work, increased blood pressure was observed in anesthetized rats following a subchronic aerosol exposure to solvent-refined coal heavy distillate (HD). To determine if this increase is a permanent, dose-related response, 11-week-old male rats were exposed by inhalation to 0, 0.24, or 0.70 mg/liter (control, low-exposure, and high-exposure groups, respectively) of HD for 6 hr/day, 5 days/week, for 6 weeks. In addition to blood pressure, select cardiovascular parameters were measured to obtain information on other possible toxic effects of the HD and also to gain some insight into potentially altered regulatory mechanisms that could be affecting the blood pressure. The angiotensin-aldosterone hormonal system, body fluid regulation, cardiac function and regulation, and pulmonary gas-exchange capabilities were examined. Two weeks after the end of exposure, mean blood pressures and heart rates of anesthetized animals in the low-and high-exposure groups were elevated relative to the controls. Plasma angiotensin concentrations decreased with increasing dose, whereas aldosterone concentrations were unaffected. In the high-dose group, blood and plasma volumes were 20 and 28%, respectively, higher than those of controls. Seven weeks after exposure, all measured cardiovascular parameters were similar to control values. Results from this study show that a 6-week exposure to HD resulted in dose-dependent, transient changes in a variety of physiological factors considered important in cardiovascular function.

The association between circulating endostatin and a disturbed circadian blood pressure pattern in patients with type 2 diabetes.

PubMed

Wuopio, Jonas; Östgren, Carl Johan; Länne, Toste; Lind, Lars; Ruge, Toralph; Carlsson, Axel C; Larsson, Anders; Nyström, Fredrik H; Ärnlöv, Johan

2018-02-28

Endostatin, cleaved from collagen XVIII in the extracellular matrix, is a promising circulating biomarker for cardiovascular damage. It possesses anti-angiogenic and anti-fibrotic functions and has even been suggested to be involved in blood pressure regulation. Less is known if endostatin levels relate to circadian blood pressure patterns. In the present paper we studied the association between circulating levels of endostatin and nocturnal dipping in blood pressure. We used the CARDIPP-study, a cohort of middle aged, type 2 diabetics (n = 593, 32% women), with data on both 24-hour and office blood pressure, serum-endostatin, cardiovascular risk factors, and incident major cardiovascular events. Nocturnal dipping was defined as a >10% difference between day- and night-time blood pressures. Two-hundred four participants (34%) were classified as non-dippers. The mean endostatin levels were significantly higher in non-dippers compared to dippers (mean ± standard deviation: 62.6 ± 1.8 µg/l vs. 58.7 ± 1.6 µg/l, respectively, p = .007). Higher serum levels of endostatin were associated with a diminished decline in nocturnal blood pressure adjusted for age, sex, HbA1c, mean systolic day blood pressure, hypertension treatment, glomerular filtration rate, and prevalent cardiovascular disease (regression coefficient per SD increase of endostatin -0.01, 95% CI, -0.02-(-0.001), p = .03). Structural equation modelling analyses suggest that endostatin mediates 7% of the association between non-dipping and major cardiovascular events. We found an independent association between higher circulating levels of endostatin and a reduced difference between day- and night-time systolic blood pressure in patients with type 2 diabetes. Yet endostatin mediated only a small portion of the association between non-dipping and cardiovascular events arguing against a clinical utility of our findings.

Relationship between parietal blood flow studies in the left colon and the rectum in dogs. Colonic pressure and blood flow.

PubMed

Arhan, P; Bouchoucha, M; Martelli, H; Rimbert, J N; Berdeaux, A; Gallix, P; Héro, M; Barritault, L; Pellerin, D; Devroede, G

1988-01-01

An animal model was proposed to clarify the difference in occurrence of enterocolitis in congenital aganglionosis. When gaseous distention of the colon was localized to the rectosigmoid area, enterocolitis never occurred. On the contrary, when it involved the left colon, enterocolitis occurred in 13 of 15 patients. Intestinal blood flow rates were simultaneously measured in the left colon and rectum of six dogs by using labeled microspheres and expressed in function of the intraluminal pressure. Results show that for elevated values of intraluminal pressure, blood flow was significantly lower in the left colon than in the rectum. These results may explain why ischemia and necrosis occurred more frequently in the left colon than in the rectum.

An Inquiry-Based Teaching Tool for Understanding Arterial Blood Pressure Regulation and Cardiovascular Function.

ERIC Educational Resources Information Center

Collins, Heidi L.; Rodenbaugh, David W.; Murphy, Todd P.; Kulics, Jennifer M.; Bailey, Cynthia M.; DiCarlo, Stephen E.

1999-01-01

Presents a laboratory exercise designed to introduce students to the hemodynamic variables (heart rate, stroke volume, total peripheral resistance, and compliance) that alter arterial pressure. (Author/CCM)

[Progress of researches on the mechanism of cupping therapy].

PubMed

Cui, Shuai; Cui, Jin

2012-12-01

Cupping therapy of Chinese medicine is able to relieve a variety of diseases or clinical conditions, which results from the comprehensive effects of multiple types of stimulation exerted onto the regional acupoint areas. Among the stimuli, the negative pressure from cupping is one of the main factors inducing therapeutic effects. In the present paper, the authors review development of researches on the underlying mechanism of therapeutic effects of cupping-negative pressure from 1) the factor of intra-cup negative pressure; 2) influence of intra-cup negative pressure on cup-blackspot formation; 3) influence of cupping on regional blood vessels and blood flow; 4) effect of cupping on regional ultrastructure of the capillary in the raw-surface tissue; 5) effect of cupping-negative pressure on regional endothelial cells; and 6) biological effects of negative pressure drainage. Generally, cupping induced negative pressure can dilate local blood vessels to improve microcirculation, promote capillary endothelial cells repair, accelerate granulation and angiogenesis, etc., in the regional tissues, normalizing the patients' functional state at last.

Condition of cardiovascular systems of astronauts during flight of Soyuz orbital station

NASA Technical Reports Server (NTRS)

Degtyarev, V. A.; Popov, I. I.; Batenchuk-Tusko, T. V.; Kolmykova, N. D.; Lapshina, N. A.; Kirillova, Z. A.; Doroshev, V. G.; Kukushkin, Y. A.

1975-01-01

Extensive studies of blood circulation functions during manned space flight demonstrated a pronounced tendency toward an increase in minute volume of the blood and a decrease in pulse wave propagation rate. Individual blood circulation indices had large amplitude fluctuations. Physical work loads caused slow recovery of heart rate, arterial pressure and minute blood volume.

Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats.

PubMed

Zafrani, Lara; Ergin, Bulent; Kapucu, Aysegul; Ince, Can

2016-12-20

The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Twenty-seven Wistar albino rats were randomized into four groups: a sham group (n = 6), a lipopolysaccharide (LPS) group (n = 7), a LPS group that received fluid resuscitation (n = 7), and a LPS group that received blood transfusion (n = 7). The mean arterial blood pressure, renal blood flow, and renal microvascular oxygenation within the kidney cortex were recorded. Acute kidney injury was assessed using the serum creatinine levels, metabolic cost, and histopathological lesions. Nitrosative stress (expression of endothelial (eNOS) and inducible nitric oxide synthase (iNOS)) within the kidney was assessed by immunohistochemistry. Hemoglobin levels, pH, serum lactate levels, and liver enzymes were measured. Fluid resuscitation and blood transfusion both significantly improved the mean arterial pressure and renal blood flow after LPS infusion. Renal microvascular oxygenation, serum creatinine levels, and tubular damage significantly improved in the LPS group that received blood transfusion compared to the group that received fluids. Moreover, the renal expression of eNOS was markedly suppressed under endotoxin challenge. Blood transfusion, but not fluid resuscitation, was able to restore the renal expression of eNOS. However, there were no significant differences in lactic acidosis or liver function between the two groups. Blood transfusion significantly improved renal function in endotoxemic rats. The specific beneficial effect of blood transfusion on the kidney could have been mediated in part by the improvements in renal microvascular oxygenation and sepsis-induced endothelial dysfunction via the restoration of eNOS expression within the kidney.

The stress-buffering effects of functional social support on ambulatory blood pressure.

PubMed

Bowen, Kimberly S; Uchino, Bert N; Birmingham, Wendy; Carlisle, McKenzie; Smith, Timothy W; Light, Kathleen C

2014-11-01

Social support is a reliable predictor of cardiovascular health. According to the buffering hypothesis, stress is 1 mechanism by which support is able to affect physiological processes. However, most of the experimental evidence for the hypothesis comes from laboratory studies. Ambulatory blood pressure (ABP) protocols examine participants in their natural environment, where they are more likely to encounter personally relevant real-world stressors. Furthermore, prior work shows that examining support by its specific functional components reveals additional independent links to health. The current study aimed to examine the stress-buffering effects of functional social support on ABP. One hundred eighty-eight participants completed a 1-day ABP assessment along with measures of functional social support and both global perceived stress and momentary stress at time of reading. RESULTS indicated main effects for both stress measures. Global support, emotional, tangible, and informational support only moderated the effects of momentary stress, but not global stress, in predicting ABP. Informational support was the most consistent stress-buffering predictor of ABP, predicting both ambulatory systolic and diastolic blood pressure. The predicted values in ABP for informational support achieved health-relevant differences, emphasizing the value of examining functional support beyond global support alone. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Effects of complete water fasting and regeneration diet on kidney function, oxidative stress and antioxidants.

PubMed

Mojto, V; Gvozdjakova, A; Kucharska, J; Rausova, Z; Vancova, O; Valuch, J

2018-01-01

The aim of the study was to observe the influence of 11-days complete water fasting (WF) and regeneration diet (RD) on renal function, body weight, blood pressure and oxidative stress. Therapeutic WF is considered a healing method. Ten volunteers drank only water for 11 days, followed by RD for the next 11 days. Data on body weight, blood pressure, kidney functions, antioxidants, lipid peroxidation, cholesterols, triacylglycerols and selected biochemical parameters were obtained. WF increased uric acid and creatinine and decreased glomerular filtration rate. After RD, the parameters were comparable to baseline values. Urea was not affected. Lipid peroxidation (TBARS) decreased and maintained stable after RD. Fasting decreased α-tocopherol and increased γ-tocopherol, no significant changes were found after RD. Coenzyme Q10 decreased after RD. HDL-cholesterol decreased in WF. Total- and LDL-cholesterol decreased after RD. Other biochemical parameters were within the range of reference values. The effect of the complete fasting on kidney function was manifested by hyperuricemia. Renal function was slightly decreased, however maintained within the reference values. After RD, it returned to baseline values. The positive effect of the complete water fasting was in the reduction of oxidative stress, body weight and blood pressure (Tab. 3, Ref. 25).

Renal sympathetic denervation for treatment of resistant hypertension: Egyptian experience.

PubMed

Hamza, Mohamed; Khamis, Hazem

2014-08-01

Among the Egyptian population with essential hypertension, a minority are under control (systolic pressure <140 mmHg and diastolic pressure <90 mmHg), despite the use of multiple antihypertensive medications. In this article, we describe our experience with percutaneous treatment using renal artery radiofrequency (RF) ablation. To evaluate the feasibility, efficacy, and safety of catheter-based radiofrequency renal sympathetic denervation for treatment of resistant hypertension in Egyptian patients. Patients with essential hypertension unresponsive to at least 3 types of antihypertensive medical therapy (baseline office systolic blood pressure ≥160 mmHg) (n = 55) were enrolled between February 2012 and June 2013 and received percutaneous RF ablation. Patients were followed up for 6 months after treatment to detect any change in office-based measurement of blood pressure. Urine and blood samples were taken to evaluate the effects on renal function. A reduction of mean office blood pressure was seen from 174/103 ± 9/5 mmHg at baseline to 150/91 ± 8/5 mmHg at 6 months follow-up (P = 0.001). Also, we noted a significant decrease in plasma renin activity (3.66 ± 0.64 vs. 3.37 ± 0.47 ng/mL per hour; P = 0.003), and there were no periprocedural complications, no adverse events, and no change in renal function during the follow-up period. Also, no change was noted in the number of medications after 6 months (3.95 ± 1.64 vs. 3.67 ± 0.72; P = 0.27). In this observational study, catheter-based renal denervation causes sustained blood pressure reduction in patients with resistant hypertension, without serious adverse events. © 2014, Wiley Periodicals, Inc.

Circulating Blood eNOS Contributes to the Regulation of Systemic Blood Pressure and Nitrite Homeostasis

PubMed Central

Wood, Katherine C.; Cortese-Krott, Miriam M.; Kovacic, Jason C.; Noguchi, Audrey; Liu, Virginia B.; Wang, Xunde; Raghavachari, Nalini; Boehm, Manfred; Kato, Gregory J.; Kelm, Malte; Gladwin, Mark T.

2013-01-01

Objective Mice genetically deficient in endothelial nitric oxide synthase (eNOS−/−) are hypertensive with lower circulating nitrite levels, indicating the importance of constitutively produced nitric oxide (NO•) to blood pressure regulation and vascular homeostasis. While the current paradigm holds that this bioactivity derives specifically from expression of eNOS in endothelium, circulating blood cells also express eNOS protein. A functional red cell eNOS that modulates vascular NO• signaling has been proposed. Approach and Results To test the hypothesis that blood cells contribute to mammalian blood pressure regulation via eNOS-dependent NO• generation, we cross-transplanted WT and eNOS−/− mice, producing chimeras competent or deficient for eNOS expression in circulating blood cells. Surprisingly, we observed a significant contribution of both endothelial and circulating blood cell eNOS to blood pressure and systemic nitrite levels, the latter being a major component of the circulating NO• reservoir. These effects were abolished by the NOS inhibitor L-NAME and repristinated by the NOS substrate L-Arginine, and were independent of platelet or leukocyte depletion. Mouse erythrocytes were also found to carry an eNOS protein and convert 14C-Arginine into 14C-Citrulline in a NOS-dependent fashion. Conclusions These are the first studies to definitively establish a role for a blood borne eNOS, using cross transplant chimera models, that contributes to the regulation of blood pressure and nitrite homeostasis. This work provides evidence suggesting that erythrocyte eNOS may mediate this effect. PMID:23702660

Assessing endothelial function and providing calibrated UFMD data using a blood pressure cuff

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maltz, Jonathan S.

Methods and apparatus are provided for assessing endothelial function in a mammal. In certain embodiments the methods involve using a cuff to apply pressure to an artery in a subject to determine a plurality of baseline values for a parameter related to endothelial function as a function of applied pressure (P.sub.m); b) applying a stimulus to the subject; and applying external pressure P.sub.m to the artery to determine a plurality of stimulus-effected values for the parameter related to endothelial function as a function of applied pressure (P.sub.m); where the baseline values are determined from measurements made when said mammal ismore » not substantially effected by said stimulus and differences in said baseline values and said stimulus-effected values provide a measure of endothelial function in said mammal.« less

Vascular Adaptation to Exercise in Humans: Role of Hemodynamic Stimuli

PubMed Central

Green, Daniel J.; Hopman, Maria T. E.; Padilla, Jaume; Laughlin, M. Harold; Thijssen, Dick H. J.

2017-01-01

On the 400th anniversary of Harvey's Lumleian lectures, this review focuses on “hemodynamic” forces associated with the movement of blood through arteries in humans and the functional and structural adaptations that result from repeated episodic exposure to such stimuli. The late 20th century discovery that endothelial cells modify arterial tone via paracrine transduction provoked studies exploring the direct mechanical effects of blood flow and pressure on vascular function and adaptation in vivo. In this review, we address the impact of distinct hemodynamic signals that occur in response to exercise, the interrelationships between these signals, the nature of the adaptive responses that manifest under different physiological conditions, and the implications for human health. Exercise modifies blood flow, luminal shear stress, arterial pressure, and tangential wall stress, all of which can transduce changes in arterial function, diameter, and wall thickness. There are important clinical implications of the adaptation that occurs as a consequence of repeated hemodynamic stimulation associated with exercise training in humans, including impacts on atherosclerotic risk in conduit arteries, the control of blood pressure in resistance vessels, oxygen delivery and diffusion, and microvascular health. Exercise training studies have demonstrated that direct hemodynamic impacts on the health of the artery wall contribute to the well-established decrease in cardiovascular risk attributed to physical activity. PMID:28151424

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geyskes, G.G.; Oei, H.Y.; Puylaert, C.B.

Radioisotope renography was performed in 21 patients with hypertension and unilateral renal artery stenosis with and without premedication with 25 mg of captopril, and the results were compared with the effect of percutaneous transluminal angioplasty on the blood pressure, assessed 6 weeks after angioplasty. Angioplasty caused a considerable decrease in blood pressure in 15 of the 21 patients. In 12 of these 15 patients, captopril induced changes in the time-activity curves of the affected kidney only, suggesting deterioration of the excretory function of that kidney, while the function of the contralateral kidney remained normal. After angioplasty the asymmetry in themore » time-activity curves diminished despite identical pretreatment with captopril. Such captopril-induced unilateral impairment of the renal function was not seen in the six patients with unilateral renal artery stenosis whose blood pressure did not change after percutaneous transluminal angioplasty or in 13 patients with hypertension and normal renal arteries. The functional impairment of the affected kidneys was characterized by a decrease of /sup 99m/Tc-diethylenetriamine pentaacetic acid uptake and a delay of /sup 131/I-hippurate excretion, while the /sup 131/I-hippurate uptake remained unaffected. These data are in agreement with a reduced glomerular filtration rate and diuresis during preservation of the renal blood flow, changes that can be expected after converting enzyme inhibition in a kidney with low perfusion and an active, renin-mediated autoregulation of the glomerular filtration rate. These data suggest that functional captopril-induced unilateral changes, shown by split renal function studies with noninvasive gamma camera scintigraphy, can be used as a diagnostic test for renovascular hypertension caused by unilateral renal artery stenosis.« less

An implantable blood pressure and flow transmitter.

NASA Technical Reports Server (NTRS)

Rader, R. D.; Meehan, J. P.; Henriksen, J. K. C.

1973-01-01

A miniature totally implantable FM/FM telemetry system has been developed to simultaneously measure blood pressure and blood flow, thus providing an appreciation of the hemodynamics of the circulation to the entire body or to a particular organ. Developed for work with animal subjects, the telemetry system's transmission time is controlled by an RF signal that permits an operating life of several months. Pressure is detected by a miniature intravascular transducer and flow is detected by an extravascular interferometric ultrasonic technique. Both pressure and flow are calibrated prior to implanting. The pressure calibration can be checked after the implanting by cannulation; flow calibration can be verified only at the end of the experiment by determining the voltage output from the implanted sensing system as a function of several measured flow rates. The utility of this device has been established by its use in investigating canine renal circulation during exercise, emotional encounters, administration of drugs, and application of accelerative forces.

[Salt, renal function and high blood pressure--reflections on a current issue].

PubMed

Aurell, Mattias

2002-11-21

The role of salt intake for blood pressure control has been discussed for a long time. A brief review is given of some pertinent physiological facts to explain this relationship and evolutionary aspects of renal function are emphasized. Salt intake is very high in the modern society, often as high as 15 g sodium chloride per 24 hours while 3-6 g may be more than enough to maintain an adequate salt balance. If the kidneys cannot cope with this severe sodium overload, blood pressure will rise. Therefore, the kidneys' ability to excrete sodium is a key factor and the salt excretion capacity is the kidneys' major barostatic function. As barostats, the kidneys control the blood pressure by ultimately determining the sodium excretion. Reducing sodium intake is, however, difficult as more than 50% of the intake is contained in the food we buy such as bread, sausages, canned food, chips and fast-food. Food products should therefore be "salt declared", but information on this aspect is generally lacking. If the population's salt intake could be reduced by 50%, the prevalence of hypertension will be much reduced, perhaps also by as much as 50%. The cost to society for treating hypertension would be reduced accordingly. Salt intake is also an important aspect of the overweight problem among today's youth. Salt and overweight impose great health risks later in life. Preventive measures in this area must be given high priority in future health care work.

Oscillometric blood pressure devices and simulators: measurements of repeatability and differences between models.

PubMed

Sims, A J; Reay, C A; Bousfield, D R; Menes, J A; Murray, A

2005-01-01

To measure the repeatability and pressure pulse envelope of simulators used for testing oscillometric non-invasive blood pressure (NIBP) devices; to study the effect of different envelopes on NIBP devices, and to measure the difference between NIBP devices due to different oscillometric algorithms. Three different models of NIBP simulator and 18 different patient monitors with NIBP function were studied. We developed a pressure measurement system (accuracy 0.048?mmHg) to measure the repeatability of simulators. The effect of changing the envelope was measured by using three simulators with one NIBP device. Differences between 18 NIBP devices were measured using one simulator at seven blood pressure settings. Simulators generate repeatable pressure pulse envelopes (< 0.2 mmHg) but the magnitude and shape depends on the model of simulator. Oscillometric NIBP devices are highly repeatable (< 2 mmHg) when presented with a repeatable pressure pulse envelope, but different devices employ different algorithms and give different results. For a simulated standard blood pressure setting of 120/80 mmHg, estimates of systolic pressure ranged from 112.6 to 126.6 mmHg (sd of 3.0 mmHg), and diastolic pressure ranged from 74.8 to 86.9 mmHg (sd of 3.5 mmHg). Simulators and NIBP devices are sufficiently repeatable for clinical use, but further systematic clinical studies are required to better characterize the pressure pulse envelope for different patient groups.

A computational analysis of the long-term regulation of arterial pressure

PubMed Central

Beard, Daniel A.

2013-01-01

The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production—the acute pressure-diuresis and pressure-natriuresis curves—physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the “Guyton-Coleman model”, no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. representing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex. PMID:24555102

A computational analysis of the long-term regulation of arterial pressure.

PubMed

Beard, Daniel A; Pettersen, Klas H; Carlson, Brian E; Omholt, Stig W; Bugenhagen, Scott M

2013-01-01

The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production-the acute pressure-diuresis and pressure-natriuresis curves-physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the "Guyton-Coleman model", no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. representing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex.

Dietary sodium and health: more than just blood pressure.

PubMed

Farquhar, William B; Edwards, David G; Jurkovitz, Claudine T; Weintraub, William S

2015-03-17

Sodium is essential for cellular homeostasis and physiological function. Excess dietary sodium has been linked to elevations in blood pressure (BP). Salt sensitivity of BP varies widely, but certain subgroups tend to be more salt sensitive. The mechanisms underlying sodium-induced increases in BP are not completely understood but may involve alterations in renal function, fluid volume, fluid-regulatory hormones, the vasculature, cardiac function, and the autonomic nervous system. Recent pre-clinical and clinical data support that even in the absence of an increase in BP, excess dietary sodium can adversely affect target organs, including the blood vessels, heart, kidneys, and brain. In this review, the investigators review these issues and the epidemiological research relating dietary sodium to BP and cardiovascular health outcomes, addressing recent controversies. They also provide information and strategies for reducing dietary sodium. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Cardiovascular Autonomic Dysfunction in Patients with Drug-Induced Parkinsonism

PubMed Central

Ryu, Dong-Woo; Oh, Ju-Hee; Lee, Yang-Hyun; Park, Sung-Jin; Jeon, Kipyung; Lee, Jong-Yun; Ho, Seong Hee; So, Jungmin; Im, Jin Hee; Lee, Kwang-Soo

2017-01-01

Background and Purpose Recent studies have shown that several nonmotor symptoms differ between Parkinson's disease (PD) and drug-induced parkinsonism (DIP). However, there have been no reports on cardiovascular autonomic function in DIP, and so this study investigated whether cardiovascular autonomic function differs between PD and DIP patients. Methods This study consecutively enrolled 20 DIP patients, 99 drug-naïve PD patients, and 25 age-matched healthy controls who underwent head-up tilt-table testing and 24-h ambulatory blood pressure monitoring. Results Orthostatic hypotension was more frequent in patients with PD or DIP than in healthy controls. In DIP, orthostatic hypotension was associated with the underlying psychiatric diseases and neuroleptics use, whereas prokinetics were not related to orthostatic hypotension. The supine blood pressure, nighttime blood pressure, and nocturnal blood pressure dipping did not differ significantly between the DIP and control groups. Supine hypertension and nocturnal hypertension were more frequent in PD patients than in controls. Conclusions The included DIP patients frequently exhibited orthostatic hypotension that was associated with the underlying diseases as well as the nature of and exposure time to the offending drugs. Clinicians should individualize the manifestations of DIP according to underlying diseases as well as the action mechanism of and exposure time to each offending drug. PMID:27730767

The granin VGF promotes genesis of secretory vesicles, and regulates circulating catecholamine levels and blood pressure.

PubMed

Fargali, Samira; Garcia, Angelo L; Sadahiro, Masato; Jiang, Cheng; Janssen, William G; Lin, Wei-Jye; Cogliani, Valeria; Elste, Alice; Mortillo, Steven; Cero, Cheryl; Veitenheimer, Britta; Graiani, Gallia; Pasinetti, Giulio M; Mahata, Sushil K; Osborn, John W; Huntley, George W; Phillips, Greg R; Benson, Deanna L; Bartolomucci, Alessandro; Salton, Stephen R

2014-05-01

Secretion of proteins and neurotransmitters from large dense core vesicles (LDCVs) is a highly regulated process. Adrenal LDCV formation involves the granin proteins chromogranin A (CgA) and chromogranin B (CgB); CgA- and CgB-derived peptides regulate catecholamine levels and blood pressure. We investigated function of the granin VGF (nonacronymic) in LDCV formation and the regulation of catecholamine levels and blood pressure. Expression of exogenous VGF in nonendocrine NIH 3T3 fibroblasts resulted in the formation of LDCV-like structures and depolarization-induced VGF secretion. Analysis of germline VGF-knockout mouse adrenal medulla revealed decreased LDCV size in noradrenergic chromaffin cells, increased adrenal norepinephrine and epinephrine content and circulating plasma epinephrine, and decreased adrenal CgB. These neurochemical changes in VGF-knockout mice were associated with hypertension. Germline knock-in of human VGF1-615 into the mouse Vgf locus rescued the hypertensive knockout phenotype, while knock-in of a truncated human VGF1-524 that lacks several C-terminal peptides, including TLQP-21, resulted in a small but significant increase in systolic blood pressure compared to hVGF1-615 mice. Finally, acute and chronic administration of the VGF-derived peptide TLQP-21 to rodents decreased blood pressure. Our studies establish a role for VGF in adrenal LDCV formation and the regulation of catecholamine levels and blood pressure.

Management of Hypertension in Diabetic Nephropathy: How Low Should We Go?

PubMed

Sternlicht, Hillel; Bakris, George L

2016-01-01

Hypertension is a frequent comorbidity often following the development of diabetic nephropathy among individuals with type 1 diabetes and affecting most patients with type 2 diabetes at the time of diagnosis. Multiple prospective randomized placebo-controlled trials demonstrate that tight blood pressure control among patients with diabetic nephropathy reduces the rates of macrovascular and microvascular complications. While randomized trials exist and support a blood pressure goal of <140/90 mm Hg for patients with nondiabetic kidney disease, there are no prospective data regarding a specific blood pressure goal on progression of diabetic nephropathy. Retrospective data analyses from trials show a linear relationship between either baseline or achieved study blood pressure and progression of nephropathy. Very high albuminuria is a hallmark of diabetic nephropathy with reductions by either angiotensin converting enzyme inhibitors (ACEi) or angiotensin receptor blocker (ARB) monotherapy associated with slowed nephropathy progression. However, combination antihypertensive therapy, while decreasing proteinuria, augments the risk of hyperkalemia, hypotension, and kidney dysfunction. Given the lack of trial data for a BP goal among patients with diabetic nephropathy, prospective trials are needed to define the optimal blood pressure necessary to preserve kidney function. At present, guideline blood pressure goals of less than 140/90 mm Hg and the use of ACEi or ARB therapy for those with more than 300 mg of albuminuria are mandated. © 2016 S. Karger AG, Basel.

Evidence for cardiovascular autonomic dysfunction in neonates with coarctation of the aorta.

PubMed

Polson, Jaimie W; McCallion, Naomi; Waki, Hidefumi; Thorne, Gareth; Tooley, Mark A; Paton, Julian F R; Wolf, Andrew R

2006-06-20

Coarctation of the aorta (CoA) is associated with hypertension and abnormalities of blood pressure control, which persist after late repair. Assumptions that neonatal repair would prevent development of blood pressure abnormalities have not been supported by recent data. We hypothesized that early pathological adjustment of autonomic cardiovascular function may already be established in the neonate with coarctation. We studied 8 otherwise well neonates with simple CoA and compared measures of spontaneous baroreflex sensitivity, heart rate variability, and blood pressure variability with 13 healthy newborn babies. Spontaneous baroreflex sensitivity was calculated with sequence methodology from an ECG, and noninvasive blood pressure was recorded with a Portapres. Heart rate variability was determined with time- and frequency-domain measures. Blood pressure variability was measured in the frequency domain. In comparison with normal controls, neonates with CoA had raised blood pressure (78.9+/-3.8 versus 67.1+/-2.1 mm Hg), depressed baroreflex sensitivity (8.7+/-1.5 versus 13.8+/-1.1 ms/mm Hg), reduced heart rate variability (total power 16.5+/-3.1 versus 31.5+/-2.2 ms2), and an increase in the high-frequency component of blood pressure variability (3.1+/-0.3 versus 2.2+/-0. 2 mm Hg2). This is not the pattern expected if neonates with CoA simply had subclinical cardiac failure. These data suggest that infants with CoA already show signs of pathological adjustment of autonomic cardiovascular homeostasis. Further longitudinal studies are required to determine whether these alterations play a role in the increased risk of late hypertension in these patients.

Modeling metabolic syndrome and its association with cognition: the Northern Manhattan study.

PubMed

Levin, Bonnie E; Llabre, Maria M; Dong, Chuanhui; Elkind, Mitchell S V; Stern, Yaakov; Rundek, Tatjana; Sacco, Ralph L; Wright, Clinton B

2014-11-01

Metabolic syndrome (MetS) is a clustering of vascular risk factors and is associated with increased risk of cardiovascular disease. Less is known about the relationship between MetS and cognition. We examined component vascular risk factors of MetS as correlates of different cognitive domains. The Northern Manhattan Study (NOMAS) includes 1290 stroke-free participants from a largely Hispanic multi-ethnic urban community. We used structural equation modeling (SEM) to model latent variables of MetS, assessed at baseline and an average of 10 years later, at which time participants also underwent a full cognitive battery. The two four-factor models, of the metabolic syndrome (blood pressure, lipid levels, obesity, and fasting glucose) and of cognition (language, executive function, psychomotor, and memory), were each well supported (CFI=0.97 and CFI=0.95, respectively). When the two models were combined, the correlation between metabolic syndrome and cognition was -.31. Among the metabolic syndrome components, only blood pressure uniquely predicted all four cognitive domains. After adjusting for age, gender, race/ethnicity, education, smoking, alcohol, and risk factor treatment variables, blood pressure remained a significant correlate of all domains except memory. In this stroke-free race/ethnically diverse community-based cohort, MetS was associated with cognitive function suggesting that MetS and its components may be important predictors of cognitive outcomes. After adjusting for sociodemographic and vascular risk factors, blood pressure was the strongest correlate of cognitive performance. Findings suggest MetS, and in particular blood pressure, may represent markers of vascular or neurodegenerative damage in aging populations.

Aerobic Exercise Training and Arterial Changes in African-Americans versus Caucasians

PubMed Central

Ranadive, Sushant M.; Yan, Huimin; Lane, Abbi D.; Kappus, Rebecca M.; Cook, Marc D.; Sun, Peng; Harvey, Idethia; Ploutz-Synder, Robert; Woods, Jeffrey A.; Wilund, Kenneth R.; Fernhall, Bo

2015-01-01

African-Americans (AA) have increased carotid artery intima-media thickness and decreased vascular function compared to their Caucasian (CA) peers. Aerobic exercise prevents and potentially reverses arterial dysfunction. Purpose The purpose of this study was to examine the effect of 8 weeks of moderate-high intensity aerobic training in young healthy sedentary AA and CA men and women. Methods Sixty-four healthy volunteers (men = 28, women = 36) with mean age = 24 underwent measures of arterial structure, function and blood pressure variables at baseline, post-4 week control period and 8 weeks post-training. Results There was a significant increase in VO2peak amongst both groups post exercise training. Brachial systolic blood pressure decreased significantly following control period in both groups but not following exercise training. Carotid pulse pressure decreased significantly in both groups post exercise training as compared to baseline. There was no change in any of the other blood pressure variables. AAs had a higher intima-media thickness at baseline and post-control period, but significantly decreased following exercise training compared to CAs. AAs had significantly lower baseline forearm blood flow and RH compared to CAs, but exercise training had no effect on these variables. There was no significant difference in arterial stiffness (cPWV) and wave-reflection (AIx) between the two groups at any time point. Conclusions This is the first study to show that, 8 weeks of aerobic exercise training causes significant improvement in the arterial structure in young, healthy AAs, making it comparable to the CAs and with minimal effects on blood pressure variables. PMID:26225767

Combined food and micronutrient supplements during pregnancy have limited impact on child blood pressure and kidney function in rural Bangladesh.

PubMed

Hawkesworth, Sophie; Wagatsuma, Yukiko; Kahn, Ashraf I; Hawlader, Mohammad D H; Fulford, Anthony J C; Arifeen, Shams-El; Persson, Lars-Åke; Moore, Sophie E

2013-05-01

Observational evidence suggests nutritional exposures during in utero development may have long-lasting consequences for health; data from interventions are scarce. Here, we present a trial follow-up study to assess the association between prenatal food and micronutrient supplementation and childhood blood pressure and kidney function. During the MINIMat Trial in rural Bangladesh, women were randomly assigned early in pregnancy to receive an early or later invitation to attend a food supplementation program and additionally to receive either iron and folate or multiple micronutrient tablets daily. The 3267 singleton birth individuals with measured anthropometry born during the trial were eligible for a follow-up study at 4.5 y old. A total of 77% of eligible individuals were recruited and blood pressure, kidney size by ultrasound, and glomerular filtration rate (GFR; calculated from plasma cystatin c) were assessed. In adjusted analysis, early invitation to food supplementation was associated with a 0.72-mm Hg [(95% CI: 0.16, 1.28); P = 0.01] lower childhood diastolic blood pressure and maternal MMS supplementation was associated with a marginally higher [0.87 mm Hg (95% CI: 0.18, 1.56); P = 0.01] childhood diastolic blood pressure. There was also some evidence that a supplement higher in iron was associated with a higher offspring GFR. No other effects of the food or micronutrient interventions were observed and there was no interaction between the interventions on the outcomes studied. These marginal associations and small effect sizes suggest limited public health importance in early childhood.

Genome-wide Linkage and Positional Association Study of Blood Pressure Response to Dietary Sodium Intervention

PubMed Central

Mei, Hao; Gu, Dongfeng; Hixson, James E.; Rice, Treva K.; Chen, Jing; Shimmin, Lawrence C.; Schwander, Karen; Kelly, Tanika N.; Liu, De-Pei; Chen, Shufeng; Huang, Jian-feng; Jaquish, Cashell E.; Rao, Dabeeru C.; He, Jiang

2012-01-01

The authors conducted a genome-wide linkage scan and positional association analysis to identify the genetic determinants of salt sensitivity of blood pressure (BP) in a large family-based, dietary-feeding study. The dietary intervention was conducted among 1,906 participants in rural China (2003–2005). A 7-day low-sodium intervention was followed by a 7-day high-sodium intervention. Salt sensitivity was defined as BP responses to low- and high-sodium interventions. Signals of the logarithm of the odds to the base 10 (LOD ≥ 3) were detected at 33–42 centimorgans of chromosome 2 (2p24.3-2p24.1), with a maximum LOD score of 3.33 for diastolic blood pressure responses to high-sodium intervention. LOD scores were 2.35–2.91 for mean arterial pressure (MAP) and 0.80–1.49 for systolic blood pressure responses in this region, respectively. Correcting for multiple tests, single nucleotide polymorphism (SNP) rs11674786 (2.7 kilobases upstream of the family with sequence similarity 84, member A, gene (FAM84A)) in the linkage region was significantly associated with diastolic blood pressure (P = 0.0007) and MAP responses (P = 0.0007), and SNP rs16983422 (2.8 kilobases upstream of the visinin-like 1 gene (VSNL1)) was marginally associated with diastolic blood pressure (P = 0.005) and MAP responses (P = 0.005). An additive interaction between SNPs rs11674786 and rs16983422 was observed, with P = 7.00 × 10−5 and P = 7.23 × 10−5 for diastolic blood pressure and MAP responses, respectively. The authors concluded that genetic region 2p24.3-2p24.1 might harbor functional variants for the salt sensitivity of BP. PMID:22865701

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor

PubMed Central

Ojeda, Norma B.; Royals, Thomas P.

2013-01-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg−1·min−1) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg−1·min−1) significantly attenuated these hemodynamic changes (P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats. PMID:23344570

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor.

PubMed

Ojeda, Norma B; Royals, Thomas P; Alexander, Barbara T

2013-04-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg(-1)·min(-1)) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg(-1)·min(-1)) significantly attenuated these hemodynamic changes (P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats.

The effects of repeated administration of camphor-crataegus berry extract combination on blood pressure and on attentional performance - a randomized, placebo-controlled, double-blind study.

PubMed

Erfurt, L; Schandry, R; Rubenbauer, S; Braun, U

2014-09-25

The present study investigated the effects of repeated administration of Korodin(®), a combination of camphor and crataegus berry extract, on blood pressure and attentional functioning. This study was conducted based on a randomized, placebo-controlled, double-blind design. 54 persons participated (33 female, 21 male) with a mean age of 24.3 years. Blood pressure and body mass index were in the normal range. Participants received 20 drops of either Korodin(®) or a placebo for four times with interjacent time intervals of about 10 min. Blood pressure was measured sphygmomanometrically before and after each administration. Attentional performance was quantified by using two paper-and-pencil tests, the d2 Test of Attention and Digit Symbol Test. Greater increases in blood pressure occurred after the four Korodin(®) administrations in comparison to the four placebo administrations. The performance in two parameters of d2 Test of Attention was consistently superior after the intake of Korodin(®). The excellent tolerability and safety of Korodin(®), even after a total consumption of 80 drops, was confirmed. Copyright © 2014 Elsevier GmbH. All rights reserved.

Association of serum uric acid level and blood pressure in type 2 diabetes mellitus

NASA Astrophysics Data System (ADS)

Savira, M.; Rusdiana; Syahputra, M.

2018-03-01

Uric acid is an end product of purine degradation in humans and primarily excreted through urine. In adulthood, concentrations rise steadily over time and vary with height, body weight, blood pressure, renal function, and alcohol intake. Uric acid is known as anti-oxidant, it has a beneficial role in diseases. Elevated serum uric acid associated with anincreased risk of cardiovascular disease. It has been found that elevated levels of uric acid associated with high risks of acomplication of type 2 diabetes mellitus and It has astrong association between elevated uric acid levels and obesity, metabolic syndrome, diabetes mellitus, hypertension, cardiovascular and renal disorders. The aim of the study analyzed the association between serum uric acid level and blood pressure in type 2 diabetes mellitus patients. This research is descriptive analytic research with a cross sectional design included 50 diabetic subjects aged over 40 years old. Subjects picked by consecutive sampling then we examined the weight, height, waist size, blood pressure, fasting blood sugar, and serum uric acid level. Statistical analysis using chi-square found that there was no significant association between serum uric acid level and systole and diastole pressure in type 2 diabetes mellitus patients (p>0.005).

Acute Health Impact of Air Pollution in China

NASA Astrophysics Data System (ADS)

Feng, T.; Zhao, Y.; Zheng, M.

2014-12-01

Air pollution not only has long term health impact, but can affect health through acute exposure. This paper, using air pollution index (API) as overall evaluation of air quality, blood pressure and vital capacity as health outcomes, focuses on the acute health impact of air pollution in China. Current result suggests that after controlling smoking history, occupational exposure, income and education, API is positively associated with blood pressure and negatively associated with vital capacity. The associations became stronger for people with hypertension or pulmonary functional diseases, which indicates that these people are more sensitive to air pollution. Among three pollutants which API measures, that is inhalable particles (PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2), PM10 is most statistically associated with blood pressure increase and vital capacity decrease. Further study will focusing on the following two questions. The first question is how various time lags affect the associations among API, blood pressure and vital capacity. The second question is how differently people in various cohorts reacts to acute exposure to air pollution. The differences in reactions of blood pressure and vital capacity between people in urban and rural areas, genders, various age cohorts, distinct income and education groups will be further studied.

Consumption of High-Polyphenol Dark Chocolate Improves Endothelial Function in Individuals with Stage 1 Hypertension and Excess Body Weight

PubMed Central

Nogueira, Lívia de Paula; Knibel, Marcela Paranhos; Torres, Márcia Regina Simas Gonçalves; Nogueira Neto, José Firmino; Sanjuliani, Antonio Felipe

2012-01-01

Background. Hypertension and excess body weight are important risk factors for endothelial dysfunction. Recent evidence suggests that high-polyphenol dark chocolate improves endothelial function and lowers blood pressure. This study aimed to evaluate the association of chocolate 70% cocoa intake with metabolic profile, oxidative stress, inflammation, blood pressure, and endothelial function in stage 1 hypertensives with excess body weight. Methods. Intervention clinical trial includes 22 stage 1 hypertensives without previous antihypertensive treatment, aged 18 to 60 years and presents a body mass index between 25.0 and 34.9 kg/m2. All participants were instructed to consume 50 g of chocolate 70% cocoa/day (2135 mg polyphenols) for 4 weeks. Endothelial function was evaluated by peripheral artery tonometry using Endo-PAT 2000 (Itamar Medical). Results. Twenty participants (10 men) completed the study. Comparison of pre-post intervention revealed that (1) there were no significant changes in anthropometric parameters, percentage body fat, glucose metabolism, lipid profile, biomarkers of inflammation, adhesion molecules, oxidized LDL, and blood pressure; (2) the assessment of endothelial function through the reactive hyperemia index showed a significant increase: 1.94 ± 0.18 to 2.22 ± 0.08, P = 0.01. Conclusion.In individuals with stage 1 hypertension and excess body weight, high-polyphenol dark chocolate improves endothelial function. PMID:23209885

Effect of high protein vs high carbohydrate intake on insulin sensitivity, body weight, hemoglobin A1c, and blood pressure in patients with type 2 diabetes mellitus.

PubMed

Sargrad, Karin R; Homko, Carol; Mozzoli, Maria; Boden, Guenther

2005-04-01

Extremely low carbohydrate/high protein diets are popular methods of weight loss. Compliance with these diets is poor and long-term effectiveness and the safety of these diets for patients with type 2 diabetes is not known. The objective of the current study was to evaluate effects of less extreme changes in carbohydrate or protein diets on weight, insulin sensitivity, glycemic control, cardiovascular risk factors (blood pressure, lipid levels), and renal function in obese inner-city patients with type 2 diabetes. Study patients were admitted to the General Clinical Research Center for 24 hours for initial tests including a hyperinsulinemic-euglycemic clamp (for measurement of insulin sensitivity), bioelectrical impedance analysis (BIA) and anthropometric measurements (for assessment of body composition), indirect calorimetry (for measurement of REE), electronic blood pressure monitoring, and blood chemistries to measure blood lipids levels along with renal and hepatic functions. Six patients with type 2 diabetes (five women and one man) were randomly assigned to the high-protein diet (40% carbohydrate, 30% protein, 30% fat) and six patients (four women and two men) to the high-carbohydrate diet (55% carbohydrate, 15% protein, 30% fat). All patients returned to the General Clinical Research Center weekly for monitoring of food records; dietary compliance; and measurements of body weight, blood pressure, and blood glucose. After 8 weeks on these diets, all patients were readmitted to the General Clinical Research Center for the same series of tests. Twelve study patients were taught to select either the high-protein or high-carbohydrate diet and were followed for 8 weeks. Insulin sensitivity, hemoglobin A1c, weight, and blood pressure were measured. Statistical significance was assessed using two-tailed Student's t tests and two-way repeated measures analysis of variance. Both the high-carbohydrate and high-protein groups lost weight (-2.2+/-0.9 kg, -2.5+/-1.6 kg, respectively, P <.05) and the difference between the groups was not significant (P =.9). In the high-carbohydrate group, hemoglobin A1c decreased (from 8.2% to 6.9%, P <.03), fasting plasma glucose decreased (from 8.8 to 7.2 mmol/L, P <.02), and insulin sensitivity increased (from 12.8 to 17.2 micromol/kg/min, P <.03). No significant changes in these parameters occurred in the high-protein group, instead systolic and diastolic blood pressures decreased (-10.5+/-2.3 mm Hg, P =.003 and -18+/-9.0 mm Hg, P <.05, respectively). After 2 months on these hypocaloric diets, each diet had either no or minimal effects on lipid levels (total cholesterol, low-density lipoprotein, high-density lipoprotein), renal (blood urea nitrogen, serum creatinine), or hepatic function (aspartate aminotransferase, alanine aminotransferase, bilirubin).

Cardiovascular autonomic modulation and activity of carotid baroreceptors at altitude.

PubMed

Bernardi, L; Passino, C; Spadacini, G; Calciati, A; Robergs, R; Greene, R; Martignoni, E; Anand, I; Appenzeller, O

1998-11-01

1. To assess the effects of acute exposure to high altitude on baroreceptor function in man we evaluated the effects of baroreceptor activation on R-R interval and blood pressure control at high altitude. We measured the low-frequency (LF) and high-frequency (HF) components in R-R, non-invasive blood pressure and skin blood flow, and the effect of baroreceptor modulation by 0. 1-Hz sinusoidal neck suction. Ten healthy sea-level natives and three high-altitude native, long-term sea-level residents were evaluated at sea level, upon arrival at 4970 m and 1 week later.2. Compared with sea level, acute high altitude decreased R-R and increased blood pressure in all subjects [sea-level natives: R-R from 1002+/-45 to 775+/-57 ms, systolic blood pressure from 130+/-3 to 150+/-8 mmHg; high-altitude natives: R-R from 809+/-116 to 749+/-47 ms, systolic blood pressure from 110+/-12 to 125+/-11 mmHg (P<0.05 for all)]. One week later systolic blood pressure was similar to values at sea level in all subjects, whereas R-R remained elevated in sea-level natives. The low-frequency power in R-R and systolic blood pressure increased in sea-level natives [R-R-LF from 47+/-8 to 65+/-10% (P<0.05), systolic blood pressure-LF from 1.7+/-0. 3 to 2.6+/-0.4 ln-mmHg2 (P<0.05)], but not in high-altitude natives (R-R-LF from 32+/-13 to 38+/-19%, systolic blood pressure-LF from 1. 9+/-0.5 to 1.7+/-0.8 ln-mmHg2). The R-R-HF decreased in sea-level natives but not in high-altitude natives, and no changes occurred in systolic blood pressure-HF. These changes remained evident 1 week later. Skin blood flow variability and its spectral components decreased markedly at high altitude in sea-level natives but showed no changes in high-altitude natives. Neck suction significantly increased the R-R- and systolic blood pressure-LF in all subjects at both sea level and high altitude.3. High altitude induces sympathetic activation in sea-level natives which is partially counteracted by active baroreflex. Despite long-term acclimatization at sea level, high-altitude natives also maintain active baroreflex at high altitude but with lower sympathetic activation, indicating a persisting high-altitude adaptation which may be genetic or due to baroreflex activity not completely lost by at least 1 year's sea-level residence.

Effect of continuous positive airway pressure therapy on hypothalamic-pituitary-adrenal axis function and 24-h blood pressure profile in obese men with obstructive sleep apnea syndrome.

PubMed

Carneiro, Gláucia; Togeiro, Sônia Maria; Hayashi, Lílian F; Ribeiro-Filho, Fernando Flexa; Ribeiro, Artur Beltrame; Tufik, Sérgio; Zanella, Maria Teresa

2008-08-01

Obstructive sleep apnea syndrome (OSAS) increases the risk of cardiovascular events. Sympathetic nervous system and hypothalamic-pituitary-adrenal (HPA) axis activation may be the mechanism of this relationship. The aim of this study was to evaluate HPA axis and ambulatory blood pressure monitoring in obese men with and without OSAS and to determine whether nasal continuous positive airway pressure therapy (nCPAP) influenced responses. Twenty-four-hour ambulatory blood pressure monitoring and overnight cortisol suppression test with 0.25 mg of dexamethasone were performed in 16 obese men with OSAS and 13 obese men controls. Nine men with severe apnea were reevaluated 3 mo after nCPAP therapy. Body mass index and blood pressure of OSAS patients and obese controls were similar. In OSAS patients, the percentage of fall in systolic blood pressure at night (P = 0.027) and salivary cortisol suppression postdexamethasone (P = 0.038) were lower, whereas heart rate (P = 0.022) was higher compared with obese controls. After nCPAP therapy, patients showed a reduction in heart rate (P = 0.036) and a greater cortisol suppression after dexamethasone (P = 0.001). No difference in arterial blood pressure (P = 0.183) was observed after 3 mo of nCPAP therapy. Improvement in cortisol suppression was positively correlated with an improvement in apnea-hypopnea index during nCPAP therapy (r = 0.799, P = 0.010). In conclusion, men with OSAS present increased postdexamethasone cortisol levels and heart rate, which were recovered by nCPAP.

Derivation of a target concentration of Pb in soil based on elevation of adult blood pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stern, A.H.

1996-04-01

The increase in systolic blood pressure in males appears to be the most sensitive adult endpoint appropriate for deriving a health risk-based target level of lead (Ph) in soil. Because the response of blood pressure to blood Ph concentration (PbB) has no apparent threshold, traditional approaches based on the application of a Reference Dose (RfD) are not applicable. An alternative approach is presented based on a model which predicts the population shift in systolic blood pressure from ingestion of Pb contaminated soil as a simultaneous function of exposure to Pb in soil, the baseline distribution of blood Pb concentration inmore » the population and the baseline distribution of systolic pressure in the population. This model is analyzed using Monte Carlo analysis to predict the population distribution of systolic pressure resulting from Ph exposure. Based on this analysis, it is predicted that for adult males 18-65 years old, exposure to 1000 ppm Pb in soil will result in an increase of approximately 1 mm Hg systolic pressure, an increase in the incidence of systolic hypertension (i.e., systolic pressure >140 mm Hg) of approximately 1% and an increase in PbB of 1-3 {mu}g/dl. Based on the proposition that these adverse effects can be considered de minimis, 1000 ppm Ph in soil is proposed as a target soil concentration for adult exposure. Available data do not appear to be adequate to predict the newborn PbB level which would result from exposure to this soil level during pregnancy, 36 refs., 6 figs.« less

Effects of long-term blood pressure lowering and dual antiplatelet treatment on cognitive function in patients with recent lacunar stroke: a secondary analysis from the SPS3 randomised trial.

PubMed

Pearce, Lesly A; McClure, Leslie A; Anderson, David C; Jacova, Claudia; Sharma, Mukul; Hart, Robert G; Benavente, Oscar R

2014-12-01

The primary outcome results for the SPS3 trial suggested that a lower systolic target blood pressure (<130 mm Hg) might be beneficial for reducing the risk of recurrent stroke compared with a higher target (130-149 mm Hg), but that the addition of clopidogrel to aspirin was not beneficial compared with aspirin plus placebo. In this prespecified secondary outcome analysis of the SPS3 trial, we aimed to assess whether blood pressure reduction and dual antiplatelet treatment affect changes in cognitive function over time in patients with cerebral small vessel disease. In the SPS3 trial, patients with recent (within 6 months) symptomatic lacunar infarcts from 81 centres in North America, Latin America, and Spain were randomly assigned, in a two-by-two factorial design, to target levels of systolic blood pressure (1:1; 130-149 mm Hg vs <130 mm Hg; open-label) and to a once-daily antiplatelet treatment (1:1; aspirin 325 mg plus clopidogrel 75 mg vs aspirin 325 mg plus placebo; double-blind). For this analysis, the main cognitive outcome was change in Cognitive Abilities Screening Instrument (CASI) during follow-up. Patients were tested annually for up to 5 years, during which time the mean difference in systolic blood pressure was 11 mm Hg (SD 16) between the two targets (138 mm Hg vs 127 mm Hg at 1 year). We used linear mixed models to compare changes in CASI Z scores over time. The SPS3 trial is registered with ClinicalTrials.gov, number NCT00059306. The study took place between March 23, 2003, and April 30, 2012. 2916 of 3020 SPS3 participants (mean age 63 years [SD 11]) with CASI scores at study entry were included in the analysis, with a median follow-up of 3·0 years (IQR 1·0-4·9). Mean changes in CASI Z scores from study entry to assessment at years 1 (n=2472), 2 (n=1968), 3 (n=1521), 4 (n=1135), and 5 (n=803) were 0·12 (SD 0·83), 0·15 (0·84), 0·16 (0·95), 0·19 (0·99), and 0·14 (1·09), respectively. Changes in CASI Z scores over time did not differ between assigned antiplatelet groups (p=0·858) or between assigned blood pressure target groups (p=0·520). There was no interaction between assigned antiplatelet groups and assigned blood pressure target groups and change over time (p=0·196). Cognitive function is not affected by short-term dual antiplatelet treatment or blood pressure reduction in fairly young patients with recent lacunar stroke. Future studies of cognitive function after stroke should be of longer duration or focus on patients with higher rates of cognitive decline. US National Institute of Neurological Disorders and Stroke. Copyright © 2014 Elsevier Ltd. All rights reserved.

Aging-associated sensory neuropathy alters pressure-induced vasodilation in humans.

PubMed

Fromy, Bérengère; Sigaudo-Roussel, Dominique; Gaubert-Dahan, Marie-Line; Rousseau, Pascal; Abraham, Pierre; Benzoni, Daniel; Berrut, Gilles; Saumet, Jean Louis

2010-03-01

Healthy skin is protected from pressure-induced ischemic damage because of the presence of pressure-induced vasodilation (PIV). PIV relies on small sensory nerve fibers and endothelial function. Since aging alters both nervous and vascular functions, we hypothesized that PIV is altered with aging. We compared PIV in non-neuropathic and neuropathic older subjects (60-75 years) with that of young subjects (20-35 years). Laser Doppler flowmetry was used to evaluate the cutaneous responses to local pressure application, acetylcholine, and local heating. Quantitative sensory tests were used to evaluate sensory-nerve-fiber function. The non-neuropathic older subjects had an impaired PIV (12+/-7% increase in blood flow with pressure) compared with young subjects (62+/-4%, P<0.001). In the presence of peripheral neuropathy, the older subjects were totally deprived of PIV, leading to early pressure-induced cutaneous ischemia (-31+/-10%, P<0.001). This inability of the skin to adapt to localized pressure in older subjects is related to the severity of the sensory-fiber dysfunction rather than to endothelial dysfunction, which was comparable between the non-neuropathic (141+/-19% increased blood flow with acetylcholine, P<0.05) and neuropathic older subjects (145+/-28% increase, P<0.05) compared with young subjects (234+/-25% increase).

Synergistic effect of energy drinks and overweight/obesity on cardiac autonomic testing using the Valsalva maneuver in university students.

PubMed

Majeed, Farrukh; Yar, Talay; Alsunni, Ahmed; Alhawaj, Ali Fouad; AlRahim, Ahmed; Alzaki, Muneer

2017-01-01

Obesity and caffeine consumption may lead to autonomic disturbances that can result in a wide range of cardiovascular disorders. To determine autonomic disturbances produced by the synergistic effects of overweight or obesity (OW/OB) and energy drinks. Cross-sectional, analytical. Physiology department at a university in Saudi Arabia. University students, 18-22 years of age, of normal weight (NW) and OW/OB were recruited by convenience sampling. Autonomic testing by the Valsalva ratio (VR) along with systolic and diastolic blood pressure, pulse pressure, and mean arterial blood pressure were measured at baseline (0 minute) and 60 minutes after energy drink consumption. Autonomic disturbance, hemodynamic changes. In 50 (27 males and 23 females) subjects, 21 NW and 29 OW/OB, a significant decrease in VR was observed in OW/OB subjects and in NW and OW/OB females at 60 minutes after energy drink consumption. Values of systolic and diastolic blood pressure, pulse pressure and mean arterial blood pressure were also significantly higher in OW/OB and in females as compared to NW and males. BMI was negatively correlated with VR and diastolic blood pressure at 60 minutes. Obesity and energy drinks alter autonomic functions. In some individuals, OW/OB may augment these effects. Due to time and resource restraints, only the acute effects of energy drinks were examined.

BP and Vascular Function Following Space Flight

NASA Technical Reports Server (NTRS)

Hatton, Daniel C.; Yue, Qi; Chapman, Justin; Xue, Hong; Dierickx, Jacqueline; Roullet, Chantal; Roullet, Jean-Baptiste; Phanouvong, Thongchanh; Watanabe, Mitsuaki; Otsuka, Keiichi;

E-health blood pressure control program.

PubMed

Ahern, David K; Stinson, Lynda J; Uebelacker, Lisa A; Wroblewski, Joseph P; McMurray, Jerome H; Eaton, Charles B

2012-01-01

Both technological and human factors design requirements for integration of home blood pressure monitoring (HBPM) into a patient centered medical home (PCMH) model primary care practice are described. Patients with uncontrolled hypertension were given home blood pressure (BP) monitors, and after a three-month run-in period introduced to either a high-tech only (HBPM connectivity to personal health record and tailored Web portal access) or a high-tech/"high-touch" (high-tech solution plus patient navigator [PN]) solution. Features of the Web portal included: BP graphing function, traffic-light feedback system of BP goal attainment, economic incentives for self-monitoring, and dual patient-facing and care-team-facing dashboard functions. The e-health BP control system with PN support was well received by patients, providers, and the healthcare team. Current e-health technology and limited technological literacy of many patients suggest that a PN or some other personnel resource may be required for the adoption of patient-facing technology in primary care.

Non-invasive estimate of blood glucose and blood pressure from a photoplethysmograph by means of machine learning techniques.

PubMed

Monte-Moreno, Enric

2011-10-01

This work presents a system for a simultaneous non-invasive estimate of the blood glucose level (BGL) and the systolic (SBP) and diastolic (DBP) blood pressure, using a photoplethysmograph (PPG) and machine learning techniques. The method is independent of the person whose values are being measured and does not need calibration over time or subjects. The architecture of the system consists of a photoplethysmograph sensor, an activity detection module, a signal processing module that extracts features from the PPG waveform, and a machine learning algorithm that estimates the SBP, DBP and BGL values. The idea that underlies the system is that there is functional relationship between the shape of the PPG waveform and the blood pressure and glucose levels. As described in this paper we tested this method on 410 individuals without performing any personalized calibration. The results were computed after cross validation. The machine learning techniques tested were: ridge linear regression, a multilayer perceptron neural network, support vector machines and random forests. The best results were obtained with the random forest technique. In the case of blood pressure, the resulting coefficients of determination for reference vs. prediction were R(SBP)(2)=0.91, R(DBP)(2)=0.89, and R(BGL)(2)=0.90. For the glucose estimation, distribution of the points on a Clarke error grid placed 87.7% of points in zone A, 10.3% in zone B, and 1.9% in zone D. Blood pressure values complied with the grade B protocol of the British Hypertension society. An effective system for estimate of blood glucose and blood pressure from a photoplethysmograph is presented. The main advantage of the system is that for clinical use it complies with the grade B protocol of the British Hypertension society for the blood pressure and only in 1.9% of the cases did not detect hypoglycemia or hyperglycemia. Copyright © 2011 Elsevier B.V. All rights reserved.

Altered Blood Flow Response to Small Muscle Mass Exercise in Cancer Survivors Treated With Adjuvant Therapy.

PubMed

Didier, Kaylin D; Ederer, Austin K; Reiter, Landon K; Brown, Michael; Hardy, Rachel; Caldwell, Jacob; Black, Christopher; Bemben, Michael G; Ade, Carl J

2017-02-07

Adjuvant cancer treatments have been shown to decrease cardiac function. In addition to changes in cardiovascular risk, there are several additional functional consequences including decreases in exercise capacity and increased incidence of cancer-related fatigue. However, the effects of adjuvant cancer treatment on peripheral vascular function during exercise in cancer survivors have not been well documented. We investigated the vascular responses to exercise in cancer survivors previously treated with adjuvant cancer therapies. Peripheral vascular responses were investigated in 11 cancer survivors previously treated with adjuvant cancer therapies (age 58±6 years, 34±30 months from diagnosis) and 9 healthy controls group matched for age, sex, and maximal voluntary contraction. A dynamic handgrip exercise test at 20% maximal voluntary contraction was performed with simultaneous measurements of forearm blood flow and mean arterial pressure. Forearm vascular conductance was calculated from forearm blood flow and mean arterial pressure. Left ventricular ejection time index (LVETi) was derived from the arterial pressure wave form. Forearm blood flow was attenuated in cancer therapies compared to control at 20% maximal voluntary contraction (189.8±53.8 vs 247.9±80.3 mL·min -1 , respectively). Forearm vascular conductance was not different between groups at rest or during exercise. Mean arterial pressure response to exercise was attenuated in cancer therapies compared to controls (107.8±10.8 vs 119.2±16.2 mm Hg). LEVTi was lower in cancer therapies compared to controls. These data suggest an attenuated exercise blood flow response in cancer survivors ≈34 months following adjuvant cancer therapy that may be attributed to an attenuated increase in mean arterial pressure. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Evaluation of Acute Kidney Injury and Mortality After Intensive Blood Pressure Control in Patients With Intracerebral Hemorrhage.

PubMed

Burgess, L Goodwin; Goyal, Nitin; Jones, G Morgan; Khorchid, Yasser; Kerro, Ali; Chapple, Kristina; Tsivgoulis, Georgios; Alexandrov, Andrei V; Chang, Jason J

2018-04-13

We sought to assess the risk of acute kidney injury (AKI) and mortality associated with intensive systolic blood pressure reduction in acute intracerebral hemorrhage. Patients with acute intracerebral hemorrhage had spontaneous cause and symptom onset within 24 hours. We excluded patients with structural causes, coagulopathy, thrombocytopenia, and preexisting end-stage renal disease. We defined AKI using the Acute Kidney Injury Network criteria. Chronic kidney disease status was included in risk stratification and was defined by Kidney Disease Outcomes Quality Initiative staging. Maximum systolic blood pressure reduction was defined over a 12-hour period and dichotomized using receiver operating characteristic curve analysis. Descriptive statistics were done using independent sample t tests, χ 2 tests, and Mann-Whitney U tests, whereas multivariable logistic regression analysis was used to evaluate for predictors for AKI and mortality. A total of 448 patients with intracerebral hemorrhage met inclusion criteria. Maximum systolic blood pressure reduction was dichotomized to 90 mm Hg and found to increase the risk of AKI in patients with normal renal function (odds ratio, 2.1; 95% confidence interval, 1.19-3.62; P =0.010) and chronic kidney disease (odds ratio, 3.91; 95% confidence interval, 1.26-12.15; P =0.019). The risk of AKI was not significantly different in normal renal function versus chronic kidney disease groups when adjusted for demographics, presentation characteristics, and medications associated with AKI. AKI positively predicted mortality for patients with normal renal function (odds ratio, 2.41; 95% confidence interval, 1.11-5.22; P =0.026) but not for patients with chronic kidney disease (odds ratio, 3.13; 95% confidence interval, 0.65-15.01; P =0.154). These results indicate that intensive systolic blood pressure reduction with a threshold >90 mm Hg in patients with acute intracerebral hemorrhage may be an independent predictor for AKI. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Urotensin-II System in Genetic Control of Blood Pressure and Renal Function

PubMed Central

Debiec, Radoslaw; Christofidou, Paraskevi; Denniff, Matthew; Bloomer, Lisa D.; Bogdanski, Pawel; Wojnar, Lukasz; Musialik, Katarzyna; Charchar, Fadi J.; Thompson, John R.; Waterworth, Dawn; Song, Kijoung; Vollenweider, Peter; Waeber, Gerard; Zukowska-Szczechowska, Ewa; Samani, Nilesh J.; Lambert, David; Tomaszewski, Maciej

2013-01-01

Urotensin-II controls ion/water homeostasis in fish and vascular tone in rodents. We hypothesised that common genetic variants in urotensin-II pathway genes are associated with human blood pressure or renal function. We performed family-based analysis of association between blood pressure, glomerular filtration and genes of the urotensin-II pathway (urotensin-II, urotensin-II related peptide, urotensin-II receptor) saturated with 28 tagging single nucleotide polymorphisms in 2024 individuals from 520 families; followed by an independent replication in 420 families and 7545 unrelated subjects. The expression studies of the urotensin-II pathway were carried out in 97 human kidneys. Phylogenetic evolutionary analysis was conducted in 17 vertebrate species. One single nucleotide polymorphism (rs531485 in urotensin-II gene) was associated with adjusted estimated glomerular filtration rate in the discovery cohort (p = 0.0005). It showed no association with estimated glomerular filtration rate in the combined replication resource of 8724 subjects from 6 populations. Expression of urotensin-II and its receptor showed strong linear correlation (r = 0.86, p<0.0001). There was no difference in renal expression of urotensin-II system between hypertensive and normotensive subjects. Evolutionary analysis revealed accumulation of mutations in urotensin-II since the divergence of primates and weaker conservation of urotensin-II receptor in primates than in lower vertebrates. Our data suggest that urotensin-II system genes are unlikely to play a major role in genetic control of human blood pressure or renal function. The signatures of evolutionary forces acting on urotensin-II system indicate that it may have evolved towards loss of function since the divergence of primates. PMID:24391740

Age, Sex, and Blood Pressure-Related Influences on Reference Values of Left Atrial Deformation and Mechanics From a Large-Scale Asian Population.

PubMed

Liao, Jo-Nan; Chao, Tze-Fan; Kuo, Jen-Yuan; Sung, Kuo-Tzu; Tsai, Jui-Peng; Lo, Chi-In; Lai, Yau-Huei; Su, Cheng-Huang; Hung, Chung-Lieh; Yeh, Hung-I; Chen, Shih-Ann

2017-10-01

Left atrial (LA) function is tightly linked to several cardiovascular diseases and confers key prognostic information. Speckle tracking-based deformation as a feasible and sensitive LA mechanical assessment has proven its clinical significance beyond volume measures; however, the reference values remain largely unknown. We studied 4042 participants undergoing annual cardiovascular survey. Among them, 2812 healthy participants (65% men; mean age, 47.4±9.9 years) were eligible for speckle tracking analysis. Peak atrial longitudinal systolic strain and strain rate (SR) at systolic (SRs), early diastolic (SRe), and late diastolic atrial contraction phases (SRa) were analyzed by dedicated software (EchoPAC, GE) and compared in terms of age, sex, and blood pressure. Overall, women demonstrated higher peak atrial longitudinal systolic strain (39.34±7.99% versus 37.95±7.96%; P<0.001) and showed age-dependent more pronounced peak atrial longitudinal systolic strain functional decay than those of men (P value for interaction, <0.05), with men showing higher SRs and SRa, although lower SRe (all P<0.001). Both increasing age and higher blood pressure were independently associated with deteriorated peak atrial longitudinal systolic strain, SRs, and SRe, although augmented LA SRa, even after accounting for baseline clinical covariates in multivariable models that incorporated LA volume, NT-proBNP (N-terminal pro-B-type natriuretic peptide), or left ventricular E/e' (all P<0.001). Our findings suggest LA mechanical functional decays in association with increasing age and higher blood pressure, which seem to be compensated for by augmentation of atrial pump function. We have also provided age- and sex-stratified reference values for strain and SR based on a large-scale Asian population. © 2017 American Heart Association, Inc.

A randomised controlled trial evaluating the effect of potassium supplementation on vascular function and the renin-angiotensin-aldosterone system.

PubMed

Graham, U M; McCance, D R; Young, I S; Mullan, K R

2014-05-01

There is limited evidence on the effect of potassium supplementation on the vasculature in patients at increased cardiovascular risk. Potassium increases aldosterone and there is a strong association of hyperaldosteronism with poor cardiac outcomes. We aimed to determine whether potassium supplementation has a significant medium-term effect on aldosterone levels and, if so, what the overall effect of this is on vascular function in patients at moderate cardiovascular disease risk. Forty patients at moderate cardiovascular disease risk were included in a randomised placebo-controlled crossover study. Patients were assigned to 64 mmol potassium chloride or placebo for 6 weeks. Vascular function was assessed using pulse-wave analysis including the detection of a change in augmentation index to salbutamol and nitroglycerine-induced vasodilation. There was no change in augmentation index with potassium vs placebo (25.2±1.4 vs. 26.0±1.3%, respectively). Potassium improved brachial systolic blood pressure (131.8±2.2 vs. 137.1±2.4 mm Hg; P=0.013), central systolic blood pressure (123.2±2.3 vs. 128.4±2.3 mm Hg; P=0.011) and central diastolic blood pressure (80.3±1.3 vs. 83.7±1.4 mm Hg; P=0.019). Plasma renin activity and serum aldosterone both increased with potassium (P=0.001 and P=0.048 respectively). We found that potassium supplementation had no effect on endothelial function or pulse-wave analysis. It lowered brachial systolic and central blood pressure. It was associated with increased plasma renin activity and serum aldosterone.

[Relation between parathyroid hormone and cardiovascular risk in patients with vitamin D deficiency].

PubMed

Casado Cerrada, Jesús; Parra Caballero, Pedro; Vega Piris, Lorena; Suárez Fernández, Carmen

2013-10-05

Vitamin D deficiency and parathyroid hormone (PTH) are associated with an increased cardiovascular risk and arterial stiffness. The aim of our study is to compare the cardiovascular risk in subjects with low vitamin D, attending to the PTH concentration, as well as evaluating the response after administration of vitamin D. Prospective study of patients with a concentration of 25(OH)-vitamin D below 30nmol/l. We evaluated vascular risk parameters as blood pressure, arterial stiffness, lipid profile and glucose metabolism. Patients received vitamin D supplements for 3 months, after which the previous parameters were reassessed. A total of 32 patients were included. Those with PTH over 65pg/ml were older, had worse renal function, higher systolic blood pressure, pulse pressure and arterial stiffness. Treatment with vitamin D showed a statistically significant trend to lower blood pressure and pulse wave velocity. The increase in PTH in patients with low vitamin D involves poor control of blood pressure and increased vascular stiffness. Vitamin D replacement shows a tendency to reduce these parameters. Copyright © 2012 Elsevier España, S.L. All rights reserved.

[Effects of long-term antihypertensive therapy with losartan on blood pressure and cognitive function in patients with essential hypertension and other cerebrovascular risk factors (AWARE observational study)].

PubMed

Schrader, Jürgen; Lüders, Stephan; Diener, Hans-Christoph; Haller, Hermann; Schmieder, Roland E; Wahle, Klaus; Smolka, Wenefrieda; Jung, Claudia; Bestehorn, Kurt

2008-07-15

As arterial hypertension is the most important risk factor for ischemic stroke, the relevant guidelines recommend rigorous treatment to normalize blood pressure. Hypertension can also be associated with cognitive decline and dementia. Therefore, the effect of a long-term therapy with the AT(1) antagonist losartan (+/- hydro chloro thiazide [HCTZ]) on cognitive function in patients with essential hypertension and additional cerebrovascular risk factors was investigated. Prospective, open observational study in 6,206 adult patients with known essential hypertension and cerebrovascular risk factors (most with a 10-year stroke risk of >or= 20% based on the Framingham Score). Demographic data, blood pressure, selected laboratory parameters, and cognitive function (c.I. test) were determined at baseline and after 3, 6, and 12 months. The patients' mean age was 65.8+/-10.7 years and 46.1% of the patients were male. In addition to treatment with losartan +/- HCTZ, 54.1% of the patients received one or more additional antihypertensive agents. After 1 year of treatment, systolic/diastolic blood pressure fell from its baseline level of 158.1/90.3 mmHg to 137.3/80.6 mmHg (-20.8/-9.7 mmHg). The proportion of patients with no/mild/severe cognitive impairment was 30.0%/30.3%/39.7% at baseline and 34.8%/28.1%/37.1% at the end of the study. In patients with cognitive impairment, fibrinogen and hsCRP (high-sensitive C-reactive protein) levels were significantly elevated. Adverse events (AEs) were reported in 231 patients (3.7%), while serious/nonserious AEs possibly related to the study medication were reported in only six (0.1%) and 38 patients (0.6%), respectively. A high proportion of patients with hypertension shows cognitive impairment; therefore, use of appropriate tests to detect this should be considered. The losartan-based antihypertensive treatment increased the proportion of patients with normal cognitive function, reduced blood pressure, and was well tolerated in the primary-care setting.

The Relationship between Self-Efficacy and Resting Blood Pressure in Spousal Alzheimer’s Caregivers

PubMed Central

Harmell, Alexandrea L.; Mausbach, Brent T; Roepke, Susan K.; Moore, Raeanne; von Känel, Roland; Patterson, Thomas L; Dimsdale, Joel E; Mills, Paul J; Ziegler, Michael G.; Allison, Matthew A.; Ancoli-Israel, Sonia; Grant, Igor

2011-01-01

OBJECTIVE To examine whether increased self-efficacy for using problem-focused coping was significantly related to several resting blood pressure measures in spousal Alzheimer’s disease caregivers. METHODS Participants included 100 older caregivers (mean age= 73.8 ± 8.14 years) providing in home care for a spouse with Alzheimer’s disease (AD). All participants completed a 13 item short form of the coping self-efficacy scale and underwent an in-home assessment where a visiting nurse took the average of three serial blood pressure readings. Multiple regression was used to examine the relationship between self-efficacy and mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP) after controlling for age, gender, smoking history, body mass index, the care recipient’s clinical dementia rating (CDR), diabetes, alcohol use, and the use of anti-hypertensive medications. RESULTS Overall, increased self-efficacy (as measured by the Coping Self-efficacy scale) was significantly related to lower resting MAP (β = −.26, t(90) = −2.47, p = .016) and SBP (β=−.28, t(90)= −2.74, p= .007) . Self-efficacy was marginally associated with resting DBP, but not significant (β = −.20, t(90) = −1.91, p= .06). Lastly, self-efficacy was significantly related to pulse pressure (β = −.21, t(90) = −2.31 p= .023). In addition, 1 standard deviation increase in self-efficacy was associated with a decrease of approximately 4 mmHg in SBP. CONCLUSIONS These results suggest an association between high self-efficacy on resting blood pressure. Because psychosocial interventions for Alzheimer’s caregivers have potential to increase self-efficacy, it appears possible that these interventions could have a beneficial impact on caregivers’ cardiovascular function. PMID:21489059

[Vascular adrenal cyst causing difficult to control high blood pressure].

PubMed

García Escudero, D; Torres Roca, M; Hernández Contreras, M E; Sánchez Rodríguez, C; Oñate Celdrán, J

Hypertension is a prevalent disease in developed countries. Adrenal masses, and especially adrenal cysts, are a rare and usually asymptomatic finding, which can go unnoticed or be detected as incidental findings in imaging tests. These circumstances make the multidisciplinary approach mandatory. The case is presented on a 72 year-old woman with uncontrolled high blood pressure referred to the Urology Department due to the incidental finding of a right retroperitoneal mass. A functional and imaging study was performed, establishing a diagnosis of adrenal cyst causing hypertensive symptoms. A literature search was performed in order to assess diagnostic and therapeutic approaches. With the diagnosis of adrenal cyst causing uncontrolled high blood pressure, a right laparoscopic adrenalectomy was performed. After surgery the patient has maintained blood pressure within the normal range. A multidisciplinary approach is necessary for the management of rare diseases. The surgical approach, if possible, should be laparoscopic. Copyright © 2017 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

Blood pressure variability in man: its relation to high blood pressure, age and baroreflex sensitivity.

PubMed

Mancia, G; Ferrari, A; Gregorini, L; Parati, G; Pomidossi, G; Bertinieri, G; Grassi, G; Zanchetti, A

1980-12-01

1. Intra-arterial blood pressure and heart rate were recorded for 24 h in ambulant hospitalized patients of variable age who had normal blood pressure or essential hypertension. Mean 24 h values, standard deviations and variation coefficient were obtained as the averages of values separately analysed for 48 consecutive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation aations and variation coefficient were obtained as the averages of values separately analysed for 48 consecurive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for heart rate were smaller. 3. In hypertensive subjects standard deviation for mean arterial pressure was greater than in normotensive subjects of similar ages, but this was not the case for variation coefficient, which was slightly smaller in the former than in the latter group. Normotensive and hypertensive subjects showed no difference in standard deviation and variation coefficient for heart rate. 4. In both normotensive and hypertensive subjects standard deviation and even more so variation coefficient were slightly or not related to arterial baroreflex sensitivity as measured by various methods (phenylephrine, neck suction etc.). 5. It is concluded that blood pressure variability increases and heart rate variability decreases with age, but that changes in variability are not so obvious in hypertension. Also, differences in variability among subjects are only marginally explained by differences in baroreflex function.

Small-molecule WNK inhibition regulates cardiovascular and renal function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamada, Ken; Park, Hyi-Man; Rigel, Dean F.

The With-No-Lysine (K) (WNK) kinases play a critical role in blood pressure regulation and body fluid and electrolyte homeostasis. Herein, we introduce the first orally bioavailable pan-WNK-kinase inhibitor, WNK463, that exploits unique structural features of the WNK kinases for both affinity and kinase selectivity. In rodent models of hypertension, WNK463 affects blood pressure and body fluid and electro-lyte homeostasis, consistent with WNK-kinase-associated physiology and pathophysiology.

Neuromodulation therapy does not influence blood flow distribution or left-ventricular dynamics during acute myocardial ischemia.

PubMed

Kingma, J G; Linderoth, B; Ardell, J L; Armour, J A; DeJongste, M J; Foreman, R D

2001-08-13

Electrical stimulation of the dorsal aspect of the upper thoracic spinal cord is used increasingly to treat patients with angina pectoris refractory to conventional therapeutic strategies. The purpose of this study was to determine whether spinal cord stimulation (SCS) in dogs affects regional myocardial blood flow and left-ventricular (LV) function before and during transient obstruction of the left anterior descending coronary artery (LAD). In anesthetized dogs, regional myocardial blood flow distribution was determined using radiolabeled microspheres and left-ventricular function was measured by impedance-derived pressure-volume loops. SCS was accomplished by stimulating the dorsal T1-T2 segments of the spinal cord using epidural bipolar electrodes at 90% of motor threshold (MT) (50 Hz, 0.2-ms duration). Effects of 5-min SCS were assessed under basal conditions and during 4-min occlusion of the LAD. SCS alone evoked no change in regional myocardial blood flow or cardiovascular indices. Transient LAD occlusion significantly diminished blood flow within ischemic, but not in non-ischemic myocardial tissue. Left ventricular pressure-volume loops were shifted rightward during LAD occlusion. Cardiac indices were altered similarly during LAD occlusion and concurrent SCS. SCS does not influence the distribution of blood flow within the non-ischemic or ischemic myocardium. Nor does it modify LV pressure-volume dynamics in the anesthetized experimental preparation.

Effect of black tea consumption on radial blood pulse spectrum and cognitive health.

PubMed

Chang, Chi-Wei; Wang, Sheng-Hung; Jan, Ming-Yie; Wang, Wei-Kung

2017-04-01

Black tea consumption has been proven to improve endothelial function and to lower the risk of stroke and cognitive impairment. Several effects of black tea on cardiovascular system had been surveyed. However, the black tea effect on pressure pulse spectrum remains unknown. The study was aimed to investigate the influence of black tea on radial blood pressure and Pulse Spectrum. Fourteen healthy subjects received water and single doses of black tea (0.05g/Kg) in separate weeks. The radial blood pressure and pulse wave were measured and the pressure pulses were evaluated using harmonic analysis. This report confirmed that black tea consumption (dose=0.05g/Kg) significantly increased third, fifth, (P<0.1), sixth, seventh, and eighth harmonics (p<0.05) of radial pressure wave comparing to water control. We proposed that black tea may increase cerebral blood flow (CBF), which was deduced from the results and from the conclusions of previous studies. The results also showed that the harmonic components of pressure pulse could be the vascular kinetic index that assessed the hemodynamic status in each time frame before and after consumption of black tea. Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of prazosin in management of hypertension in patients with chronic renal failure and in renal transplant recipients.

PubMed Central

Curtis, J R; Bateman, F J

1975-01-01

Prazosin was used in combination with other antihypertensive drugs in the successful management of hypertension in seven patients with chronic renal failure and six renal transplant recipients, also with chronic renal failure. The addition of small doses of prazosin (mean 3 mg/day) to the antihypertensive regimen produced significant falls in systolic and diastolic blood pressures in both the lying and standing positions. The standing blood pressures were significantly lower than the lying blood pressures during prazosin treatment. Neither the mean blood urea concentrations nor the mean plasma creatinine concentrations changed significantly during prazosin administration. Chromium-51 edetic acid clearances did not change significantly during prazosin treatment in the seven patients in whom it was measured. Severe symptomatic postural hypotension occurred in one patient a week after starting prazosin 3 mg/day. This hypotensive episode was associated with a transient and reversible deterioration in renal function. Another patient developed a rash while on prazosin but it was probably related to propranolol rather than prazosin. Prazosin is thus an effective antihypertensive drug in patients with chronic renal failure, and it may be used with a variety of other drugs. It should be used cautiously, however, since patients with chronic renal failure may respond to small doses, and significant postural falls in blood pressure may result. There was no evidence that the use of prazosin resulted in progressive deterioration in the residual renal function of the patients with chronic renal failure. PMID:811312

Use of prazosin in management of hypertension in patients with chronic renal failure and in renal transplant recipients.

PubMed

Curtis, J R; Bateman, F J

1975-11-22

Prazosin was used in combination with other antihypertensive drugs in the successful management of hypertension in seven patients with chronic renal failure and six renal transplant recipients, also with chronic renal failure. The addition of small doses of prazosin (mean 3 mg/day) to the antihypertensive regimen produced significant falls in systolic and diastolic blood pressures in both the lying and standing positions. The standing blood pressures were significantly lower than the lying blood pressures during prazosin treatment. Neither the mean blood urea concentrations nor the mean plasma creatinine concentrations changed significantly during prazosin administration. Chromium-51 edetic acid clearances did not change significantly during prazosin treatment in the seven patients in whom it was measured. Severe symptomatic postural hypotension occurred in one patient a week after starting prazosin 3 mg/day. This hypotensive episode was associated with a transient and reversible deterioration in renal function. Another patient developed a rash while on prazosin but it was probably related to propranolol rather than prazosin. Prazosin is thus an effective antihypertensive drug in patients with chronic renal failure, and it may be used with a variety of other drugs. It should be used cautiously, however, since patients with chronic renal failure may respond to small doses, and significant postural falls in blood pressure may result. There was no evidence that the use of prazosin resulted in progressive deterioration in the residual renal function of the patients with chronic renal failure.

[Catastrophic antiphospholipid syndrome in the immediate puerperium].

PubMed

Ortiz, P; Castro, A; Vallés, M; Coll, E; Casas, M; Mauri, J M

2003-01-01

We describe a female previously diagnosed of primary antiphospholipid antibody syndrome who presented a preclampsia in the second pregnancy. An urgent caesaria was made because of a worsening high blood pressure and oliguria. In the immediated puerperium she showed low platelets and persistent high blood pressure. Afterwards acute renal failure and neurological signs with a severe aortic valvulopathy were diagnosed. An haemolytic anemia was also detected. Definitive diagnosis was made by kidney biopsy with the result of a thrombotic microangiopathy. Treatment with low weight heparin and aspirin and systemic corticosteroids was started in the immediate puerperium and fresh frozen plasma was then added with a good response to treatment. Actually she is still with high blood pressure, aortic valvulopathy. Renal function is normal one year later.

Bio-functional pickles that reduce blood pressure of rats.

PubMed

Oda, Kohei; Imanishi, Takanori; Yamane, Yoshito; Ueno, Yoshie; Mori, Yoshiharu

2014-01-01

Addition of γ-aminobutyric acid (GABA) and angiotensin converting enzyme (ACE)-inhibitory peptides to the pickles was studied in order to develop a new type of pickles that reduce blood pressure. Based on the outcome of these studies, a new type of fermentation bed composed of rice bran and white miso has been successfully developed. The advantage of such pickles is that they not only contain both GABA and ACE-inhibitory peptides, but also that their taste and flavor are excellent, with colors close to the original ones. The new type of pickles could temporarily reduce blood pressure in two types of rats, spontaneously hypertensive rats and NaCl-sensitive model rats. Thus, the newly developed pickles appear to be beneficial for pickle business.

The study of dynamic response to acute hemorrhage by pulse spectrum analysis.

PubMed

Chang, Yu Hsin; Tsai, Chia I; Lin, Jaung Geng; Lin, Yue Der; Li, Tsai Chung; Su, Yi Chang

2006-01-01

Traditional Chinese Medicine (TCM) holds that blood and qi are fundamental substances in the human body for sustaining normal vital activity. The theory of qi, blood and zang-fu contribute the most important theoretical basis of human physiology in TCM. An animal model using conscious rats was employed in this study to further comprehend how organisms survive during acute hemorrhage by maintaining the functionalities of qi and blood through dynamically regulating visceral physiological conditions. Pulse waves of arterial blood pressure before and after the hemorrhage were taken in parallel to pulse spectrum analysis. Percentage differences of mean arterial blood pressure and harmonics were recorded in subsequent 5-minute intervals following the hemorrhage. Data were analyzed using a one-way analysis of variance (ANOVA) with Duncan's test for pairwise comparisons. Results showed that, within 30 minutes following the onset of acute hemorrhage,the reduction of mean arterial blood pressure was improved from 62% to 20%. Throughout the process, changes to the pulse spectrum appeared to result in a new balance over time. The percentage differences of the second and third harmonics, which were related to kidney and spleen, both increased significantly than baseline and towards another steady state. Apart from the steady state resulting from the previous stage, the percentage difference of the 4th harmonic decreased significantly to another steady state. The observed change could be attributed to the induction of functional qi, and is a result of qi-blood balancing activity that organisms hold to survive against acute bleeding.

Role of sex steroids in modulating tumor necrosis factor alpha induced changes in vascular function and blood pressure

PubMed Central

LaMarca, Babbette D.; Chandler, Derrick L.; Grubbs, Lee; Bain, Jennifer; McLemore, Gerald R.; Granger, Joey P.; Ryan, Michael J.

2007-01-01

Background We previously showed that infusion of TNF-α induces hypertension and vascular dysfunction in late pregnant but not virgin rats. In the present study we tested the hypothesis that levels of ovarian hormones to mimic pregnancy are required for TNF-α induced changes in vascular function and blood pressure in rats. Methods 21 day release pellets containing 17β-estradiol, progesterone, or both were implanted in ovariectomized (OVX) rats. Sham OVX rats were used as controls. 12 days after implantation, TNF-α or vehicle was infused via osmotic minipumps (days 12-17). On day 18, mean arterial pressure was measured and animals were sacrificed to assess vascular function. Results Average estrogen and progesterone levels across all groups were 106±6 pg/ml and 88±5 ng/ml. TNF-α was 41±7 pg/ml compared to OVX rats infused with vehicle (4±1 pg/ml). The results show that TNF-α did not cause elevated mean arterial pressure in OVX rats with increased estrogen, progesterone, both. Vascular responses to the endothelium dependent and independent agonists, acetylcholine and sodium nitroprusside, were also not changed. Phenylephrine induced contraction was moderately but significantly increased at the highest concentrations (10-4 M) only in TNF-α infused rats. Conclusion These data suggest that increased ovarian hormones to levels observed during pregnancy are not sufficient to promote TNF-α induced increases in blood pressure or vascular dysfunction. PMID:17954370

Vascular and renal function in experimental thyroid disorders.

PubMed

Vargas, Félix; Moreno, Juan Manuel; Rodríguez-Gómez, Isabel; Wangensteen, Rosemary; Osuna, Antonio; Alvarez-Guerra, Miriam; García-Estañ, Joaquín

2006-02-01

This review focuses on the effects of thyroid hormones in vascular and renal systems. Special emphasis is given to the mechanisms by which thyroid hormones affect the regulation of body fluids, vascular resistance and, ultimately, blood pressure. Vascular function is markedly affected by thyroid hormones that produce changes in vascular reactivity and endothelial function in hyper- and hypothyroidism. The hypothyroid state is accompanied by a marked decrease in sensitivity to vasoconstrictors, especially to sympathetic agonists, alteration that may play a role in the reduced blood pressure of hypothyroid rats, as well as in the preventive effects of hypothyroidism on experimental hypertension. Moreover, in hypothyroid rats, the endothelium-dependent and nitric oxide donors vasodilation is reduced. Conversely, the vessels from hyperthyroid rats showed an increased endothelium-dependent responsiveness that may be secondary to the shear-stress induced by the hyperdynamic circulation, and that may contribute to the reduced vascular resistance characteristic of this disease. Thyroid hormones also have important effects in the kidney, affecting renal growth, renal haemodynamics, and salt and water metabolism. In hyperthyroidism, there is a resetting of the pressure-natriuresis relationship related to hyperactivity of the renin-angiotensin system, which contributes to the arterial hypertension associated with this endocrine disease. Moreover, thyroid hormones affect the development and/or maintenance of various forms of arterial hypertension. This review also describes recent advances in our understanding of thyroid hormone action on nitric oxide and oxidative stress in the regulation of cardiovascular and renal function and in the long-term control of blood pressure.

The impact of serum uric acid reduction on renal function and blood pressure in chronic kidney disease patients with hyperuricemia.

PubMed

Tsuji, Takayuki; Ohishi, Kazuhisa; Takeda, Asumi; Goto, Daiki; Sato, Taichi; Ohashi, Naro; Fujigaki, Yoshihide; Kato, Akihiko; Yasuda, Hideo

2018-04-26

Febuxostat is tolerable in chronic kidney disease (CKD) patients with hyperuricemia. However, the long-term effect of lowering uric acid with febuxostat on renal function and blood pressure has not been elucidated. This was a 2 years retrospective observational study. 86 CKD patients with hyperuricemia who continued with allopurinol (allopurinol group, n = 30), switched from allopurinol to febuxostat (switched group, n = 25), or were newly prescribed febuxostat (febuxostat group, n = 31) were included in this study. Serum uric acid, estimated glomerular filtration rate (eGFR), blood pressure, and urinary protein were analyzed. Moreover, the impact of serum uric acid reduction on renal function and blood pressure was assessed. Serum uric acid in the switched and febuxostat groups was significantly reduced at 6 months (switched group; 8.49 ± 1.32-7.19 ± 1.14 mg/dL, p < 0.0001, febuxostat group; 9.43 ± 1.63-6.31 ± 0.90 mg/dL, p < 0.0001). In the allopurinol group, serum uric acid was increased (6.86 ± 0.87-7.10 ± 0.85 mg/dL, p = 0.0213). eGFR was significantly increased (35.2 ± 12.8-37.3 ± 13.9 mL/min/1.73 m 2 , p = 0.0232), while mean arterial pressure (93.1 ± 10.8-88.2 ± 9.5 mmHg, p = 0.0039) was significantly decreased at 6 months in the febuxostat group, resulting in the retention of eGFR for 2 years. The impact of serum uric acid reduction might have beneficial effects on CKD progression and blood pressure. However, a large prospective study is needed to determine the long-term efficacy of febuxostat therapy in CKD patients with hyperuricemia.

Effects of age, blood pressure and antihypertensive treatments on retinal arterioles remodeling assessed by adaptive optics.

PubMed

Rosenbaum, David; Mattina, Alessandro; Koch, Edouard; Rossant, Florence; Gallo, Antonio; Kachenoura, Nadjia; Paques, Michel; Redheuil, Alban; Girerd, Xavier

2016-06-01

In humans, adaptive optics camera enables precise large-scale noninvasive retinal microcirculation evaluation to assess ageing, blood pressure and antihypertensive treatments respective roles on retinal arterioles anatomy. We used adaptive optics camera rtx1 (Imagine-Eyes, Orsay, France) to measure wall thickness, internal diameter and to calculate wall-to-lumen ratio (WLR) and wall cross-sectional area of retinal arterioles. This assessment was repeated within a short period in two subgroups of hypertensive individuals without or with a drug-induced blood pressure drop. In 1000 individuals, mean wall thickness, lumen diameter and WLR were 23.2 ± 3.9, 78.0 ± 10.9 and 0.300 ± 0.054 μm, respectively. Blood pressure and age both independently increased WLR by thickening arterial wall. In opposite, hypertension narrowed lumen in younger as compared to older individuals (73.2 ± 9.0 vs. 81.7 ± 10.2 μm; P < 0.001), whereas age exerted no influence on lumen diameter. Short-term blood pressure drop (-29.3 ± 17.3/-14.4 ± 10.0 mmHg) induced a WLR decrease (-6.0 ± 8.0%) because of lumen dilatation (+4.4 ± 5.9%) without wall thickness changes. By contrast, no modifications were observed in individuals with stable blood pressure. In treated and controlled hypertensives under monotherapy WLR normalization was observed because of combined wall decrease and lumen dilatation independently of antihypertensive pharmacological classes. In multivariate analysis, hypertension drug regimen was not an independent predictor of any retinal anatomical indices. Retinal arteriolar remodeling comprised blood pressure and age-driven wall thickening as well as blood pressure-triggered lumen narrowing in younger individuals. Remodeling reversal observed in controlled hypertensives seems to include short-term functional and long-term structural changes.

Ambient air pollution exposure and blood pressure changes during pregnancy

PubMed Central

Lee, Pei-Chen; Talbott, Evelyn O.; Roberts, James M.; Catov, Janet M.; Bilonick, Richard A.; Stone, Roslyn A.; Sharma, Ravi K.; Ritz, Beate

2013-01-01

Background Maternal exposure to ambient air pollution has been associated with adverse birth outcomes such as preterm delivery. However, only one study to date has linked air pollution to blood pressure changes during pregnancy, a period of dramatic cardiovascular function changes. Objectives We examined whether maternal exposures to criteria air pollutants, including particles of less than 10 µm (PM10) or 2.5 µm diameter (PM2.5), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3), in each trimester of pregnancy are associated with magnitude of rise of blood pressure between the first 20 weeks of gestation and late pregnancy in a prospectively followed cohort of 1684 pregnant women in Allegheny County, PA. Methods Air pollution measures for maternal ZIP code areas were derived using Kriging interpolation. Using logistic regression analysis, we evaluated the associations between air pollution exposures and blood pressure changes between the first 20 weeks of gestation and late pregnancy. Results First trimester PM10 and ozone exposures were associated with blood pressure changes between the first 20 weeks of gestation and late pregnancy, most strongly in non-smokers. Per interquartile increases in first trimester PM10 and O3 concentrations were associated with mean increases in systolic blood pressure of 1.88 mmHg (95% CI = 0.84 to 2.93) and 1.84 (95% CI = 1.05 to 4.63), respectively, and in diastolic blood pressure of 0.63 mmHg (95% CI= −0.50 to 1.76) and 1.13 (95% CI= −0.46 to 2.71) in non-smokers. Conclusions Our novel finding suggests that first trimester PM10 and O3 air pollution exposures increase blood pressure in the later stages of pregnancy. These changes may play a role in mediating the relationships between air pollution and adverse birth outcomes. PMID:22835955

Blood pressure hyperreactivity: an early cardiovascular risk in normotensive men exposed to low-to-moderate inorganic arsenic in drinking water.

PubMed

Kunrath, Julie; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Gelmann, Elyssa R; Thach, Thu-Trang; McCarty, Kathleen M; Yeckel, Catherine W

2013-02-01

Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic. We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania. Unexposed (n = 16) and exposed (n = 19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (<10 μg/l). Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (> 20 mmHg) and DBP (>15 mmHg). Drinking water inorganic arsenic averaged 40.2 ± 30.4 and 1.0 ± 0.2 μg/l for the exposed and unexposed groups, respectively (P < 0.001). Compared to the unexposed group, the exposed group expressed a greater probability of blood pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P = 0.035) and cold stress (73.7 vs. 37.5%; P = 0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P = 0.035). Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk.

Nocturnal blood pressure dipping is similar in rheumatoid arthritis patients as compared to a normal population.

PubMed

Turgay Yildirim, O; Gonullu, E; Aydin, F; Aksit, E; Huseyinoglu Aydin, A; Dagtekin, E

2018-04-12

Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory disorder which further doubles the risk of developing cardiovascular disease. Some studies suggest that in RA patients, the prevalence of hypertension increases due to prednisolone use, clinical status, genetic factors, and physical inactivity. On the other hand, dipper and non-dipper status in RA patients compared to non-RA subjects has not been investigated to our knowledge. Purpose of the study is to investigate whether non-dipper status is more deteriorated in RA patients. Sixty-five RA patients and 61 age-sex-matched control patients were evaluated in this cross-sectional study. Patients were classified according to 24-h ambulatory blood pressure monitoring results. Patients with previous hypertension diagnosis, coronary artery disease, and abnormal kidney function were excluded. Mean age of the study sample was 53.7 ± 12.3 years and 40.5% were male. There was no significant difference between groups in terms of basic demographic characteristics. Leukocyte counts (p = 0.001), neutrophil counts (p = 0.001), and red cell distribution width (p = 0.000) were significantly higher in the RA group. ABPM results indicate no significant difference between RA patients and the control group in terms of daytime systolic and diastolic blood pressure, nighttime systolic and diastolic blood pressure, and average systolic and diastolic blood pressure results (p > 0.05). There was no statistical difference regarding the non-dipper status of patient groups (p = 0.412). Nocturnal blood pressure dipping was significantly similar between groups (p = 0.980). In conclusion, RA patients have similar values in terms of nocturnal blood pressure dipping and hypertension diagnosis as compared to normal population.

Maturation of Heart Rate and Blood Pressure Variability during Sleep in Term-Born Infants

PubMed Central

Yiallourou, Stephanie R.; Sands, Scott A.; Walker, Adrian M.; Horne, Rosemary S.C.

2012-01-01

Study Objectives: Abnormal blood pressure control is implicated in the sudden infant death syndrome (SIDS). However, no data exist on normal development of blood pressure control during infancy. This study assessed maturation of autonomic control of blood pressure and heart rate during sleep within the first 6 months of life. Participants: Term infants (n = 31) were studied longitudinally at 2-4 weeks, 2-3 months, and 5-6 months postnatal age. Interventions: Infants underwent daytime polysomnography at each age studied. Blood pressure and heart rate were recorded during quiet (QS) and active (AS) sleep in undisturbed baseline and head-up tilt conditions. Measurements and Results: Autonomic control was assessed using spectral indices of blood pressure and heart rate variability (BPV and HRV) in ranges of low frequency (LF, reflecting sympathetic + parasympathetic activity) and high frequency (HF, parasympathetic activity), total power (LF+HF), and LF/HF ratio (sympathovagal balance). With increasing postnatal age and predominantly during QS, HRV-LF, HRV-HF, and HRV total power increased, while HRV-LF/HF decreased. BPV-LF/HF also decreased with postnatal age. All changes were evident in both baseline and head-up tilt conditions. BPV-LF and BPV total power during tilts were markedly reduced in QS versus AS at each age. Conclusions: In sleeping infants, sympathetic vascular modulation of the circulation decreases with age, while parasympathetic control of heart rate is strengthened. These normative data will aid in the early identification of conditions where autonomic function is impaired, such as in SIDS. Citation: Yiallourou SR; Sands SA; Walker AM; Horne RSC. Maturation of heart rate and blood pressure variability during sleep in term-born infants. SLEEP 2012;35(2):177-186. PMID:22294807

Lack of validation of the Dixtal (DX 2020) upper arm blood pressure monitor, in oscillometric mode, for clinical use in an intensive care unit, according to the European Society of Hypertension-International Protocol revision 2010.

PubMed

Gothardo, Ana C L O; Savioli, Amanda F; Santos, Dayanna S; Lamas, José L T

2013-08-01

The aim of the study was to evaluate the accuracy of the oscillometric blood pressure section in the DX 2020 Dixtal multiparametric monitor in adults according to the European Society of Hypertension-International Protocol as revised in 2010 (ESH-IP 2010). The blood pressure was sequentially verified in 33 individuals admitted to an adult ICU (18 men, mean age 44 years) with a mercury column sphygmomanometer (two observers) and the DX 2020 test device (one supervisor). Ninety-nine pairs of differences were obtained. Data analysis followed the ESH-IP 2010 requirements. In the first requirement, the DX 2020 device failed in the validation study in the 5, 10, and 15 mmHg ranges. From the 99 pairs of differences, only 43/73, 69/87, and 81/96 were obtained for systolic blood pressure and 29/65, 56/81, and 71/93 were obtained for diastolic blood pressure. In the second requirement, at least 24 individuals should have, from their comparisons, two under 0-5 mmHg ranges, which was observed only with 16 individuals in the systolic and nine in the diastolic range. Moreover, at maximum, only three readings could have differences of more than 5 mmHg, and this was observed in 10 individuals in the systolic range and 17 individuals in the diastolic range. The DX 2020 automatic multiparametric monitor for blood pressure measurement has not been recommended for clinical use according to the ESH-IP 2010. It is important to highlight that this work refers only to a blood pressure measurement module and that the same conclusion cannot be drawn for its other functions.

The granin VGF promotes genesis of secretory vesicles, and regulates circulating catecholamine levels and blood pressure

PubMed Central

Fargali, Samira; Garcia, Angelo L.; Sadahiro, Masato; Jiang, Cheng; Janssen, William G.; Lin, Wei-Jye; Cogliani, Valeria; Elste, Alice; Mortillo, Steven; Cero, Cheryl; Veitenheimer, Britta; Graiani, Gallia; Pasinetti, Giulio M.; Mahata, Sushil K.; Osborn, John W.; Huntley, George W.; Phillips, Greg R.; Benson, Deanna L.; Bartolomucci, Alessandro; Salton, Stephen R.

2014-01-01

Secretion of proteins and neurotransmitters from large dense core vesicles (LDCVs) is a highly regulated process. Adrenal LDCV formation involves the granin proteins chromogranin A (CgA) and chromogranin B (CgB); CgA- and CgB-derived peptides regulate catecholamine levels and blood pressure. We investigated function of the granin VGF (nonacronymic) in LDCV formation and the regulation of catecholamine levels and blood pressure. Expression of exogenous VGF in nonendocrine NIH 3T3 fibroblasts resulted in the formation of LDCV-like structures and depolarization-induced VGF secretion. Analysis of germline VGF-knockout mouse adrenal medulla revealed decreased LDCV size in noradrenergic chromaffin cells, increased adrenal norepinephrine and epinephrine content and circulating plasma epinephrine, and decreased adrenal CgB. These neurochemical changes in VGF-knockout mice were associated with hypertension. Germline knock-in of human VGF1–615 into the mouse Vgf locus rescued the hypertensive knockout phenotype, while knock-in of a truncated human VGF1–524 that lacks several C-terminal peptides, including TLQP-21, resulted in a small but significant increase in systolic blood pressure compared to hVGF1–615 mice. Finally, acute and chronic administration of the VGF-derived peptide TLQP-21 to rodents decreased blood pressure. Our studies establish a role for VGF in adrenal LDCV formation and the regulation of catecholamine levels and blood pressure.—Fargali, S., Garcia, A. L., Sadahiro, M., Jiang, C., Janssen, W. G., Lin, W.-J., Cogliani, V., Elste, A., Mortillo, S., Cero, C., Veitenheimer, B., Graiani, G., Pasinetti, G. M., Mahata, S. K., Osborn, J. W., Huntley, G. W., Phillips, G. R., Benson, D. L., Bartolomucci, A., Salton, S. R. The granin VGF promotes genesis of secretory vesicles, and regulates circulating catecholamine levels and blood pressure. PMID:24497580

Blood pressure hyperreactivity: an early cardiovascular risk in normotensive men exposed to low-to-moderate inorganic arsenic in drinking water

PubMed Central

Kunrath, Julie; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Gelmann, Elyssa R.; Thach, Thu-Trang; Mccarty, Kathleen M.; Yeckel, Catherine W.

2012-01-01

Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic. Objective We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania. Methods Unexposed (n=16) and exposed (n=19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (<10 μg/l). Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Results Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (>20 mmHg) and DBP (>15 mmHg). Drinking water inorganic arsenic averaged 40.2±30.4 and 1.0±0.2 μg/l for the exposed and unexposed groups, respectively (P<0.001). Compared to the unexposed group, the exposed group expressed a greater probability of blood pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P=0.035) and cold stress (73.7 vs. 37.5%; P=0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P=0.035). Conclusions Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk. PMID:23203141

[Finite Element Analysis of Intravascular Stent Based on ANSYS Software].

PubMed

Shi, Gengqiang; Song, Xiaobing

2015-10-01

This paper adopted UG8.0 to bulid the stent and blood vessel models. The models were then imported into the finite element analysis software ANSYS. The simulation results of ANSYS software showed that after endothelial stent implantation, the velocity of the blood was slow and the fluctuation of velocity was small, which meant the flow was relatively stable. When blood flowed through the endothelial stent, the pressure gradually became smaller, and the range of the pressure was not wide. The endothelial shear stress basically unchanged. In general, it can be concluded that the endothelial stents have little impact on the flow of blood and can fully realize its function.

Variation in blood pressure is associated with white matter microstructure but not cognition in African Americans.

PubMed

Leritz, Elizabeth C; Salat, David H; Milberg, William P; Williams, Victoria J; Chapman, Caroline E; Grande, Laura J; Rudolph, James L; Schnyer, David M; Barber, Colleen E; Lipsitz, Lewis A; McGlinchey, Regina E

2010-03-01

Although hypertension is a major risk factor for cerebrovascular disease (CVD) and is highly prevalent in African Americans, little is known about how blood pressure (BP) affects brain-behavior relationships in this population. In predominantly Caucasian populations, high BP is associated with alterations in frontal-subcortical white matter and in executive functioning aspects of cognition. We investigated associations among BP, brain structure, and neuropsychological functioning in 52 middle-older-age African Americans without diagnosed history of CVD. All participants underwent diffusion tensor imaging for examination of white matter integrity, indexed by fractional anisotropy (FA). Three regions of interest were derived in the anterior (genu) and posterior (splenium) corpus callosum and across the whole brain. A brief neuropsychological battery was administered from which composite scores of executive function and memory were derived. Blood pressure was characterized by mean arterial blood pressure (MABP). When controlling for age, higher MABP was associated with lower FA in the genu, and there was a trend for this same relationship with regard to whole-brain FA. When the sample was broken into groups on the basis of treatment for BP regulation (medicated vs. nonmedicated), MABP was related to genu and whole-brain FA only in the nonmedicated group. Neither MABP nor FA was significantly related to either neuropsychological composite score regardless of medication use. These data provide important evidence that variation in BP may contribute to significant alterations in specific neural regions of white matter in nonmedicated individuals without symptoms of overt CVD. Copyright 2010 APA, all rights reserved

Postnatal Cardiovascular Consequences in the Offspring of Pregnant Rats Exposed to Smoking and Smoking Cessation Pharmacotherapies.

PubMed

Gopalakrishnan, Kathirvel; More, Amar S; Hankins, Gary D; Nanovskaya, Tatiana N; Kumar, Sathish

2017-06-01

Approximately 20% of pregnant women smoke despite intentions to quit. Smoking cessation drugs, such as nicotine replacement therapy (NRT) and bupropion, are recommended treatments. Adverse cardiovascular outcomes in offspring have raised concerns about NRT's safety during pregnancy. However, the effect of bupropion is unknown. Using a rat model, we determined whether NRT and bupropion interventions during pregnancy are safer than continued smoking on offspring's cardiovascular function. Male offspring of controls and dams exposed to cigarette smoke (1.6 packs/day, inhalation), nicotine (2 mg/kg/d subcutaneously), and bupropion (13 mg/kg twice daily orally) were assessed for fetoplacental weight, cardiac function, blood pressure, and vascular reactivity. Fetoplacental weights were decreased and spontaneous beating and intracellular calcium in neonatal cardiomyocytes were increased in smoking, nicotine, and bupropion offspring; however, these effects were more accentuated in smoking followed by nicotine and bupropion offspring. Increased heart rate and decreased cardiac output, stroke volume, and left ventricular percent posterior wall thickening were observed in smoking, nicotine, and bupropion offspring. The left ventricular mass was reduced in smoking and nicotine but not in bupropion offspring. Blood pressure was higher with decreased endothelium-dependent relaxation and exaggerated vascular contraction to angiotensin II in smoking and nicotine offspring, with more pronounced dysfunctions in smoking than nicotine offspring. Maternal bupropion did not impact offspring's blood pressure, endothelium-dependent relaxation, and vascular contraction. In conclusion, maternal nicotine intervention adversely affects offspring's cardiovascular outcomes, albeit less severely than continued smoking. However, bupropion causes cardiac derangement in offspring but does not adversely affect blood pressure and vascular function.

Maturation of heart rate and blood pressure variability during sleep in term-born infants.

PubMed

Yiallourou, Stephanie R; Sands, Scott A; Walker, Adrian M; Horne, Rosemary S C

2012-02-01

Abnormal blood pressure control is implicated in the sudden infant death syndrome (SIDS). However, no data exist on normal development of blood pressure control during infancy. This study assessed maturation of autonomic control of blood pressure and heart rate during sleep within the first 6 months of life. Term infants (n = 31) were studied longitudinally at 2-4 weeks, 2-3 months, and 5-6 months postnatal age. Infants underwent daytime polysomnography at each age studied. Blood pressure and heart rate were recorded during quiet (QS) and active (AS) sleep in undisturbed baseline and head-up tilt conditions. Autonomic control was assessed using spectral indices of blood pressure and heart rate variability (BPV and HRV) in ranges of low frequency (LF, reflecting sympathetic + parasympathetic activity) and high frequency (HF, parasympathetic activity), total power (LF+HF), and LF/HF ratio (sympathovagal balance). With increasing postnatal age and predominantly during QS, HRV-LF, HRV-HF, and HRV total power increased, while HRV-LF/HF decreased. BPV-LF/HF also decreased with postnatal age. All changes were evident in both baseline and head-up tilt conditions. BPV-LF and BPV total power during tilts were markedly reduced in QS versus AS at each age. In sleeping infants, sympathetic vascular modulation of the circulation decreases with age, while parasympathetic control of heart rate is strengthened. These normative data will aid in the early identification of conditions where autonomic function is impaired, such as in SIDS.

Relationship between blood pressure and cerebral blood flow during supine cycling: influence of aging

PubMed Central

Hoffman, Keegan; Tzeng, Yu-Chieh; Hansen, Alex; Ainslie, Philip N.

2015-01-01

The cerebral pressure-flow relationship can be quantified as a high-pass filter, where slow oscillations are buffered (<0.20 Hz) and faster oscillations are passed through relatively unimpeded. During moderate intensity exercise, previous studies have reported paradoxical transfer function analysis (TFA) findings (altered phase or intact gain). This study aimed to determine whether these previous findings accurately represent this relationship. Both younger (20–30 yr; n = 10) and older (62–72 yr; n = 9) adults were examined. To enhance the signal-to-noise ratio, large oscillations in blood pressure (via oscillatory lower body negative pressure; OLBNP) were induced during steady-state moderate intensity supine exercise (∼45–50% of heart rate reserve). Beat-to-beat blood pressure, cerebral blood velocity, and end-tidal Pco2 were monitored. Very low frequency (0.02–0.07 Hz) and low frequency (0.07–0.20 Hz) range spontaneous data were quantified. Driven OLBNP point estimates were sampled at 0.05 and 0.10 Hz. The OLBNP maneuvers augmented coherence to >0.97 at 0.05 Hz and >0.98 at 0.10 Hz in both age groups. The OLBNP protocol conclusively revealed the cerebrovascular system functions as a high-pass filter during exercise throughout aging. It was also discovered that the older adults had elevations (+71%) in normalized gain (+0.46 ± 0.36%/%: 0.05 Hz) and reductions (−34%) in phase (−0.24 ± 0.22 radian: 0.10 Hz). There were also age-related phase differences between resting and exercise conditions. It is speculated that these age-related changes in the TFA metrics are mediated by alterations in vasoactive factors, sympathetic tone, or the mechanical buffering of the compliance vessels. PMID:26586907

Intra-aortic balloon pumping in acute mitral regurgitation reduces aortic impedance and regurgitant fraction.

PubMed

Dekker, André L A J; Reesink, Koen D; van der Veen, Frederik H; van Ommen, G Vincent A; Geskes, Gijs G; Soemers, A Cecilia M; Maessen, Jos G

2003-04-01

Acute mitral regurgitation (MR) is present in 10% of patients presenting with cardiogenic shock. To stabilize these patients, intra-aortic balloon pumping (IABP) is recommended, but the mechanism of IABP support in these patients is unknown. This animal study was designed to describe the hemodynamic effect of intra-aortic balloon pumping during cardiogenic shock induced by acute MR. In eight calves, left ventricular pressure-volume loops, aortic and left atrial pressure, and aortic, carotid artery, and coronary blood flow were recorded. Acute MR (range 36%-79%) was created by placing a metal cage in the mitral valve. Hemodynamic data was obtained at control, during acute MR, and during acute MR with 1:1 IABP support. Acute MR caused a decrease in cardiac output (-32%, P = 0.018), blood pressure, and carotid artery flow, whereas left ventricular output (+127%, P = 0.018), end-diastolic volume, and left atrial pressure all significantly increased. Stroke work, ejection fraction, and coronary blood flow were not significantly changed, and no signs of ischemia were seen on the ECG. The IABP raised average cardiac output by 31% (P = 0.012) and significantly raised blood pressure and flow to the brain while decreasing systemic vascular resistance. Left ventricular function and mean coronary blood flow did not change, but diastolic coronary flow became more important as shown by the increase in diastolic fraction from 64% to 95%. (P = 0.028). Average MR dropped by 7.5% (P = 0.025). In conclusion, application of the IABP during acute MR lowers aortic impedance, resulting in less MR and more output toward the aorta without changing left ventricular function.

The effect of low and high-intensity cycling in diesel exhaust on flow-mediated dilation, circulating NOx, endothelin-1 and blood pressure

PubMed Central

Tebbutt, Scott J.; Carlsten, Christopher; Koehle, Michael S.

2018-01-01

Introduction Exposure to air pollution impairs aspects of endothelial function such as flow-mediated dilation (FMD). Outdoor exercisers are frequently exposed to air pollution, but how exercising in air pollution affects endothelial function and how these effects are modified by exercise intensity are poorly understood. Objectives Therefore, the purpose of this study was to determine the effects of low-intensity and high-intensity cycling with diesel exhaust (DE) exposure on FMD, blood pressure, plasma nitrite and nitrate (NOx) and endothelin-1. Methods Eighteen males performed 30-minute trials of low or high-intensity cycling (30% and 60% of power at VO2peak) or a resting control condition. For each subject, each trial was performed once while breathing filtered air (FA) and once while breathing DE (300ug/m3 of PM2.5, six trials in total). Preceding exposure, immediately post-exposure, 1 hour and 2 hours post-exposure, FMD, blood pressure and plasma endothelin-1 and NOx concentrations were measured. Data were analyzed using repeated-measures ANOVA and linear mixed model. Results Following exercise in DE, plasma NOx significantly increased and was significantly greater than FA (p<0.05). Two hours following DE exposure, endothelin-1 was significantly less than FA (p = 0.037) but exercise intensity did not modify this response. DE exposure did not affect FMD or blood pressure. Conclusion Our results suggest that exercising in DE did not adversely affect plasma NOX, endothelin-1, FMD and blood pressure. Therefore, recommendations for healthy individuals to moderate or avoid exercise during bouts of high pollution appear to have no acute protective effect. PMID:29466393

Progesterone Therapy, Endothelial Function and Cardiovascular Risk Factors: A 3-Month Randomized, Placebo-Controlled Trial in Healthy Early Postmenopausal Women

PubMed Central

Prior, Jerilynn C.; Elliott, Thomas G.; Norman, Eric; Stajic, Vesna; Hitchcock, Christine L.

2014-01-01

Background Progesterone is effective treatment for hot flushes/night sweats. The cardiovascular effects of progesterone therapy are unknown but evidence suggests that premenopausal normal estradiol with also normal progesterone levels may provide later cardiovascular protection. We compared the effects of progesterone to placebo on endothelial function, weight, blood pressure, metabolism, lipids, inflammation and coagulation. Methods and Results We conducted a randomized, double-blind, 3-month placebo-controlled trial of progesterone (300 mg daily) among 133 healthy postmenopausal women in Vancouver, Canada from 2003–2009. Endothelial function by venous occlusion plethysmography was a planned primary outcome. Enrolled women were 1–11 y since last menstruation, not using hormones (for >6 months), non-smoking, without diabetes, hypertension, heart disease or their medications. Randomized (1∶1) women (55±4 years, body mass index 25±3) initially had normal blood pressure, fasting lipid, glucose and electrocardiogram results. Endothelial function (% forearm blood flow above saline) was not changed with progesterone (487±189%, n = 18) compared with placebo (408±278%, n = 16) (95% CI diff [−74 to 232], P = 0.30). Progesterone (n = 65) and placebo (n = 47) groups had similar changes in systolic and diastolic blood pressure, resting heart rate, weight, body mass index, waist circumference, total cholesterol, low-density lipoprotein cholesterol and triglyceride levels. High-density lipoprotein was lower (−0.14 mmol/L, P = 0.001) on progesterone compared with placebo. Fasting glucose, hs-C-reactive protein, albumin and D-dimer changes were all comparable to placebo. Framingham General Cardiovascular Risk Profile scores were initially low and remained low with progesterone therapy and not statistically different from placebo. Conclusions Results indicate that progesterone has short-term cardiovascular safety. Endothelial function, weight, blood pressure, waist circumference, inflammation and coagulation were unchanged as were lipids except for HDL-C. The statistically significant decrease in HDL-C levels was not clinically important (based on lack of Cardiovascular Risk Profile change). Trial Registration ClinicalTrials.gov NCT00152438 PMID:24465425

Effects of a nitrate-rich meal on arterial stiffness and blood pressure in healthy volunteers.

PubMed

Liu, Alex H; Bondonno, Catherine P; Croft, Kevin D; Puddey, Ian B; Woodman, Richard J; Rich, Lisa; Ward, Natalie C; Vita, Joseph A; Hodgson, Jonathan M

2013-11-30

An increase in nitrate intake can augment circulating nitrite and nitric oxide. This may lead to lower blood pressure and improved vascular function. Green leafy vegetables, such as spinach, are rich sources of nitrate. We aimed to assess the acute effects of a nitrate-rich meal containing spinach on arterial stiffness and blood pressure in healthy men and women. Twenty-six participants aged 38-69years were recruited to a randomized controlled cross-over trial. The acute effects of two energy-matched (2000kJ) meals, administered in random order, were compared. The meals were either high nitrate (220mg of nitrate derived from spinach [spinach]) or low nitrate [control]. Outcome measurements were performed pre-meal and at specific time points up to 210min post meal. Spinach resulted in an eightfold increase in salivary nitrite and a sevenfold increase in salivary nitrate concentrations from pre-meal (P<0.001) to 120min post meal. Spinach compared with control resulted in higher large artery elasticity index (P<0.001), and lower pulse pressure (P<0.001) and systolic blood pressure (P<0.001). Post meal carotid-femoral pulse wave velocity (P=0.07), augmentation index (P=0.63), small artery elasticity index (P=0.98) and diastolic blood pressure (P=0.13) were not significantly altered by spinach relative to control. Therefore, consumption of a nitrate-rich meal can lower systolic blood pressure and pulse pressure and increase large artery compliance acutely in healthy men and women. If sustained, these effects could contribute to better cardiovascular health. Copyright © 2013 Elsevier Inc. All rights reserved.

Relations of Central Hemodynamics and Aortic Stiffness with Left Ventricular Structure and Function: The Framingham Heart Study.

PubMed

Kaess, Bernhard M; Rong, Jian; Larson, Martin G; Hamburg, Naomi M; Vita, Joseph A; Cheng, Susan; Aragam, Jayashree; Levy, Daniel; Benjamin, Emelia J; Vasan, Ramachandran S; Mitchell, Gary F

2016-03-25

The differing relations of steady and pulsatile components of central hemodynamics and aortic stiffness with cardiac dimensions and function have not been fully elucidated. Central hemodynamics and carotid-femoral pulse wave velocity (CFPWV, a measure of aortic stiffness) were measured by arterial tonometry in 5799 participants of the Framingham Heart Study (mean age 51 years, 54% women) and related to echocardiographic left ventricular (LV) dimensions and systolic and diastolic function using multivariable-adjusted partial Pearson correlations. Mean arterial pressure (MAP, steady component of central blood pressure) was associated positively with LV wall thickness (r=0.168; P<0.0001) but showed only a weak direct association with LV diastolic dimension (r=0.035, P=0.006). Central pulse pressure (pulsatile component of central blood pressure) showed a direct correlation with both LV diastolic dimension and LV wall thickness (r=0.08 and 0.044, both P<0.0001 in multivariable models that included MAP). CFPWV was not associated with LV structure (all P≥0.27) in MAP-adjusted models). Both MAP and CFPWV were associated inversely with LV diastolic function (E'; r=-0.140 and -0.153, respectively; both P<0.0001), and these associations persisted after additional adjustment for LV mass and central pulse pressure (r=-0.142 and -0.108, both P<0.0001). MAP and CFPWV were not associated with LV fractional shortening (P≥0.10), whereas central pulse pressure was positively related (r=0.064, P<0.0001). Pulsatile and steady components of central pressure are conjointly yet variably related to LV structure. CFPWV is related to LV diastolic function but not to systolic function. Additional studies are warranted to confirm these observations. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

The conundrum of arterial stiffness, elevated blood pressure, and aging.

PubMed

AlGhatrif, Majd; Lakatta, Edward G

2015-02-01

Isolated systolic hypertension is a major health burden that is expanding with the aging of our population. There is evidence that central arterial stiffness contributes to the rise in systolic blood pressure (SBP); at the same time, central arterial stiffening is accelerated in patients with increased SBP. This bidirectional relationship created a controversy in the field on whether arterial stiffness leads to hypertension or vice versa. Given the profound interdependency of arterial stiffness and blood pressure, this question seems intrinsically challenging, or probably naïve. The aorta's function of dampening the pulsatile flow generated by the left ventricle is optimal within a physiological range of distending pressure that secures the required distal flow, keeps the aorta in an optimal mechanical conformation, and minimizes cardiac work. This homeostasis is disturbed by age-associated, minute alterations in aortic hemodynamic and mechanical properties that induce short- and long-term alterations in each other. Hence, it is impossible to detect an "initial insult" at an epidemiological level. Earlier manifestations of these alterations are observed in young adulthood with a sharp decline in aortic strain and distensibility accompanied by an increase in diastolic blood pressure. Subsequently, aortic mechanical reserve is exhausted, and aortic remodeling with wall stiffening and dilatation ensue. These two phenomena affect pulse pressure in opposite directions and different magnitudes. With early remodeling, there is an increase in pulse pressure, due to the dominance of arterial wall stiffness, which in turn accelerates aortic wall stiffness and dilation. With advanced remodeling, which appears to be greater in men, the effect of diameter becomes more pronounced and partially offsets the effect of wall stiffness leading to plateauing in pulse pressure in men and slower increase in pulse pressure (PP) than that of wall stiffness in women. The complex nature of the hemodynamic changes with aging makes the "one-size-fits-all" approach suboptimal and urges for therapies that address the vascular profile that underlies a given blood pressure, rather than the blood pressure values themselves.

Gravitational haemodynamics and oedema prevention in the giraffe

NASA Technical Reports Server (NTRS)

Hargens, Alan R.; Millard, Ronald W.; Pettersson, Knut; Johansen, Kjell

1987-01-01

The question of how giraffes avoid pooling of blood and tissue fluid (edema) in dependent tissues of their extremities is addressed. As monitored by radiotelemetry, the blood and tissue fluid pressures that govern transcapillary exchange vary greatly with exercise. These pressures, combined with a tight skin layer, move fluid upward against gravity. The skin thus functions like a natural antigravity suit. Other mechanisms that prevent edema include precapillary vasoconstriction and low permeability of capillaries to plasma proteins.

Enalapril and losartan restored blood pressure and vascular reactivity in intrauterine undernourished rats.

PubMed

Ceravolo, Graziela S; Franco, Maria C P; Carneiro-Ramos, Marcela S; Barreto-Chaves, Maria L M; Tostes, Rita C A; Nigro, Dorothy; Fortes, Zuleica B; Carvalho, Maria Helena C

2007-01-30

Epidemiological studies suggest that intrauterine undernutrition plays an important role in the development of arterial hypertension and endothelial dysfunction in adulthood. We have evaluated the effect of the Renin Angiotensin System inhibition on the blood pressure and the mesenteric arteriolar reactivity of the intrauterine undernourished rats. Wistar rats were fed either normal or 50% of the normal intake diets, during the whole gestational period. In this study only the male offspring was used. At 16 weeks of age, the rats were used for the study of blood pressure, microvascular reactivity studied in vivo-in situ to Angiotensin II (Ang II), Bradykinin (Bk) and Acetylcholine (Ach) before and after either losartan (10 mg/kg/15 days) or enalapril (15 mg/kg/21 days) treatment. We also evaluated the mesenteric and plasmatic Angiotensin Converting Enzyme (ACE), renal function, lipid plasmatic content, and insulin and glucose metabolism. Intrauterine undernutrition induced hypertension and increased response of mesenteric arterioles to Ang II and decreased vasodilation to Bk and Ach. The treatments with losartan or enalapril normalized the blood pressure levels and significantly improved the arteriolar responses to Bk, Ach and reduced the response to Ang II. No differences have been detected to ACE activity, renal function, lipid content and insulin and glucose metabolism. This study shows for the first time that Renin Angiotensin System inhibitors can normalize the cardiovascular alterations induced by intrauterine undernutrition.

[Safety and short-term efficacy of renal sympathetic denervation in the treatment of resistant hypertension].

PubMed

Jiang, Xiong-jing; Liang, Tuo; Dong, Hui; Peng, Meng; Ma, Wen-jun; Guan, Ting; Zhang, Hui-min; Bian, Jin; Xu, Bo; Gao, Run-lin

2012-12-11

Transcatheter renal sympathetic denervation (RDN) is a novel technology/therapy in treating resistant hypertension. The present study aims to evaluate the safety and short-term efficacy of RDN for the treatment of resistant hypertension in a Chinese population. This prospective single-center pilot study was the first one conducted in China with Medtronic Ardian Symplicity Catheter System. Eight patients (6 males and 2 females) with resistant hypertension underwent RDN at our hospital from February to April 2012. All patients were followed up at one month and three months post-RDN. Blood pressure, use of antihypertensive medications, renal function and complications were recorded and analyzed. At one month and three months post-RDN, 24-hour ambulatory blood pressure monitoring showed mean systolic blood pressure and diastolic blood pressure decreased 10 (0 - 18) 13 (3 - 19) and 8 (-2 - 15), 9 (2 - 16) mm Hg throughout 24 hours respectively (P < 0.05, vs baseline). The number of drugs decreased from 4.3 ± 0.5 to 2.8 ± 0.9 and 2.5 ± 0.7 post-RSD respectively (P < 0.01). There was no significant change of renal function (P > 0.05). No complications were observed. The preliminary results revealed that RDN was safe and effective for the treatment of resistant hypertension in the Chinese population during a 3-month follow-up. Further large and long-term studies are warranted.

Cardiovascular and Postural Control Interactions during Hypergravity: Effects on Cerebral Autoregulation in Males and Females

NASA Astrophysics Data System (ADS)

Goswami, Nandu; Blaber, Andrew; Bareille, Marie-Pierre; Beck, Arnaud; Avan, Paul; Bruner, Michelle; Hinghofer-Szalkay, Helmut

2012-07-01

Orthostatic intolerance remains a problem upon return to Earth from the microgravity environment of spaceflight. A variety of conditions including hypovolemia, cerebral vasoconstriction, cerebral or peripheral vascular disease, or cardiac arrhythmias may result in syncope if the person remains upright. Current research indicates that there is a greater dependence on visual and somatosensory information at the beginning of space flight with a decreased otolith gain during prolonged space flight (Herault et al., 2002). The goal of the research is to further our understanding of the fundamental adaptive homeostatic mechanisms involved in gravity related changes in cardiovascular and postural function. Cardiovascular, cerebrovascular, and postural sensory motor control systems in male and female participants before, during, and after exposure to graded levels of hyper-G were investigated. Hypotheses: 1) Activation of skeletal muscle pump will be directly related to the degree of orthostatic stress. 2) Simultaneous measurement of heart rate, blood pressure and postural sway will predict cardio-postural stability. Blood pressure and heart rate (means and variability), postural sway, center of pressure (COP), baroreflex function, calf blood flow, middle cerebral artery blood flow, non-invasive intracranial pressure measurements, and two-breath CO2 were measured. Results from the study will be used to provide an integrated insight into mechanisms of cardio-postural control and cerebral autoregulation, which are important aspects of human health in flights to Moon, Mars and distant planets.

Racial differences in the impact of social support on nocturnal blood pressure.

PubMed

Cooper, Denise C; Ziegler, Michael G; Nelesen, Richard A; Dimsdale, Joel E

2009-06-01

To investigate whether black and white adults benefit similarly from perceived social support in relation to blood pressure (BP) dipping during sleep. The Interpersonal Support Evaluation List (ISEL, 12-item version), which measures the perceived availability of several types of functional social support, was examined for interactive effects with race on dipping of mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) derived from 24-hour ambulatory blood pressure monitoring (ABPM). The sample consisted of 156 young to middle-aged adults (61 blacks, 95 whites; mean age = 35.7 years). Mean ISEL scores did not differ between racial groups. Controlling for age, body mass index (BMI), resting BP, and socioeconomic status (SES), the interaction of social support by race yielded associations with nighttime dipping in MAP and DBP (p < .001) as well as SBP (p < .01). As ISEL scores increased among white participants, the extent of dipping increased in MAP, SBP, and DBP (p < .01), explaining 10%, 10%, and 8% of the variance, respectively. Conversely, black participants exhibited associations between increasing ISEL scores and decreasing levels of dipping in MAP, SBP, and DBP (p < .05), accounting for 9%, 8%, and 8% of the variance, respectively. As perceived social support increased, white adults received cardiovascular benefits as suggested by enhanced nocturnal dipping of BP, but black adults accrued risks as evidenced by blunted declines in BP during sleep.

Impact of statin therapy on central aortic pressures and hemodynamics: principal results of the Conduit Artery Function Evaluation-Lipid-Lowering Arm (CAFE-LLA) Study.

PubMed

Williams, Bryan; Lacy, Peter S; Cruickshank, J Kennedy; Collier, David; Hughes, Alun D; Stanton, Alice; Thom, Simon; Thurston, Herbert

2009-01-06

Statins reduce the risk of cardiovascular events in people with hypertension. This benefit could arise from a beneficial effect of statins on central aortic pressures and hemodynamics. The Conduit Artery Function Evaluation-Lipid-Lowering Arm (CAFE-LLA) study, an Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) substudy, investigated this hypothesis in a prospective placebo-controlled study of treated patients with hypertension. CAFE-LLA recruited 891 patients randomized to atorvastatin 10 mg/d or placebo from 5 centers in the United Kingdom and Ireland. Radial artery applanation tonometry and pulse-wave analysis were used to derive central aortic pressures and hemodynamic indices at repeated visits over 3.5 years of follow-up. Atorvastatin lowered low-density lipoprotein cholesterol by 32.4 mg/dL (95% confidence interval [CI], 28.6 to 36.3) and total cholesterol by 35.1 mg/dL (95% confidence interval, 30.9 to 39.4) relative to placebo. Time-averaged brachial blood pressure was similar in CAFE-LLA patients randomized to atorvastatin or placebo (change in brachial systolic blood pressure, -0.1 mm Hg [95% CI, -1.8 to 1.6], P=0.9; change in brachial pulse pressure, -0.02 mm Hg [95% CI, -1.6 to 1.6], P=0.9). Atorvastatin did not influence central aortic pressures (change in aortic systolic blood pressure, -0.5 mm Hg [95% CI, -2.3 to 1.2], P=0.5; change in aortic pulse pressure, -0.4 mm Hg [95% CI, -1.9 to 1.0], P=0.6) and had no influence on augmentation index (change in augmentation index, -0.4%; 95% CI, -1.7 to 0.8; P=0.5) or heart rate (change in heart rate, 0.25 bpm; 95% CI, -1.3 to 1.8; P=0.7) compared with placebo. The effect of statin or placebo therapy was not modified by the blood pressure-lowering treatment strategy in the factorial design. Statin therapy sufficient to significantly reduce cardiovascular events in treated hypertensive patients in ASCOT did not influence central aortic blood pressure or hemodynamics in a large representative cohort of ASCOT patients in CAFE-LLA.

Inorganic nitrate ingestion improves vascular compliance but does not alter flow-mediated dilatation in healthy volunteers.

PubMed

Bahra, M; Kapil, V; Pearl, V; Ghosh, S; Ahluwalia, A

2012-05-15

Ingestion of inorganic nitrate elevates blood and tissue levels of nitrite via bioconversion in the entero-salivary circulation. Nitrite is converted to NO in the circulation, and it is this phenomenon that is thought to underlie the beneficial effects of inorganic nitrate in humans. Our previous studies have demonstrated that oral ingestion of inorganic nitrate decreases blood pressure and inhibits the transient endothelial dysfunction caused by ischaemia-reperfusion injury in healthy volunteers. However, whether inorganic nitrate might improve endothelial function per se in the absence of a pathogenic stimulus and whether this might contribute to the blood pressure lowering effects is yet unknown. We conducted a randomised, double-blind, crossover study in 14 healthy volunteers to determine the effects of oral inorganic nitrate (8 mmol KNO(3)) vs. placebo (8 mmol KCl) on endothelial function, measured by flow-mediated dilatation (FMD) of the brachial artery, prior to and 3h following capsule ingestion. In addition, blood pressure (BP) was measured and aortic pulse wave velocity (aPWV) determined. Finally, blood, saliva and urine samples were collected for chemiluminescence analysis of [nitrite] and [nitrate] prior to and 3h following interventions. Inorganic nitrate supplementation had no effect on endothelial function in healthy volunteers (6.9±1.1% pre- to 7.1±1.1% post-KNO(3)). Despite this, there was a significant elevation of plasma [nitrite] (0.4±0.1 μM pre- to 0.7±0.2 μM post-KNO(3), p<0.001). In addition these changes in [nitrite] were associated with a decrease in systolic BP (116.9±3.8mm Hg pre- vs. 112.1±3.4 mm Hg post-KNO(3), p<0.05) and aPWV (6.5±0.1 m/s pre- to 6.2±0.1 post-KNO(3), p<0.01). In contrast KCl capsules had no effect on any of the parameters measured. These findings demonstrate that although inorganic nitrate ingestion does not alter endothelial function per se, it does appear to improve blood flow, in combination with a reduction in blood pressure. It is likely that these changes are due to the intra-vascular production of NO. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

Rapid resetting of rabbit aortic baroreceptors and reflex heart rate responses by directional changes in blood pressure.

PubMed

Burke, S L; Dorward, P K; Korner, P I

1986-09-01

In both anaesthetized and conscious rabbits, perivascular balloon inflations slowly raised or lowered mean arterial pressure (M.A.P.), at 1-2 mmHg/s, from resting to various plateau pressures. Deflations then returned the M.A.P. to resting. 'Steady-state' curves relating M.A.P. to unitary aortic baroreceptor firing, integrated aortic nerve activity and heart rate were derived during the primary and return pressure changes and they formed typical hysteresis loops. In single units, return M.A.P.-frequency curves were shifted in the same direction as the primary pressure changes by an average 0.37 mmHg per mmHg change in M.A.P. Shifts were linearly related to the changes in M.A.P. between resting and plateau levels for all pressure rises and for falls less than 30 mmHg. They were established within 30 s and were quantitatively similar to the rapid resetting of baroreceptor function curves found 15 min-2 h after a change in resting M.A.P. (Dorward, Andresen, Burke, Oliver & Korner, 1982). Unit threshold pressures were shifted within 20 s to the same extent as the over-all curve shift to which they contributed. In the whole aortic nerve, return M.A.P.-integrated activity curves were shifted to same degree as unit function curves in both anaesthetized and conscious rabbits. Simultaneous shifts of return reflex M.A.P.-heart rate curves were also seen in conscious rabbits within 30 s. During M.A.P. falls, receptor and reflex hysteresis was similar, but during M.A.P. rises, reflex shifts were double baroreceptor shifts, suggesting the involvement of other pressure-sensitive receptors. We conclude that hysteresis shifts in baroreceptor function curves, which follow the reversal of slow ramp changes in blood pressure are a form of rapid resetting. They are accompanied by rapid resetting of reflex heart rate responses. We regard this as an important mechanism in blood pressure control which produces relatively high-gain reflex responses, during slow directional pressure changes, over a wider range of absolute pressure levels than would otherwise be possible.

Meal Fatty Acids Have Differential Effects on Postprandial Blood Pressure and Biomarkers of Endothelial Function but Not Vascular Reactivity in Postmenopausal Women in the Randomized Controlled Dietary Intervention and VAScular function (DIVAS)-2 Study.

PubMed

Rathnayake, Kumari M; Weech, Michelle; Jackson, Kim G; Lovegrove, Julie A

2018-03-01

Elevated postprandial triacylglycerol concentrations, impaired vascular function, and hypertension are important independent cardiovascular disease (CVD) risk factors in women. However, the effects of meal fat composition on postprandial lipemia and vascular function in postmenopausal women are unknown. This study investigated the impact of sequential meals rich in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), or n-6 (ω-6) polyunsaturated fatty acids (PUFAs) on postprandial flow-mediated dilatation (FMD; primary outcome measure), vascular function, and associated CVD risk biomarkers (secondary outcomes) in postmenopausal women. A double-blind, randomized, crossover, postprandial study was conducted in 32 postmenopausal women [mean ± SEM ages: 58 ± 1 y; mean ± SEM body mass index (in kg/m2): 25.9 ± 0.7]. After fasting overnight, participants consumed high-fat meals at breakfast (0 min; 50 g fat, containing 33-36 g SFAs, MUFAs, or n-6 PUFAs) and lunch (330 min; 30 g fat, containing 19-20 g SFAs, MUFAs, or n-6 PUFAs), on separate occasions. Blood samples were collected before breakfast and regularly after the meals for 480 min, with specific time points selected for measuring vascular function and blood pressure. Postprandial FMD, laser Doppler imaging, and digital volume pulse responses were not different after consuming the test fats. The incremental area under the curve (iAUC) for diastolic blood pressure was lower after the MUFA-rich meals than after the SFA-rich meals (mean ± SEM: -2.3 ± 0.3 compared with -1.5 ± 0.3 mm Hg × 450 min × 103; P = 0.009), with a similar trend for systolic blood pressure (P = 0.012). This corresponded to a lower iAUC for the plasma nitrite response after the SFA-rich meals than after the MUFA-rich meals (-1.23 ± 0.7 compared with -0.17 ± 0.4 μmol/L × 420 min P = 0.010). The soluble intercellular adhesion molecule 1 (sICAM-1) time-course profile, AUC, and iAUC were lower after the n-6 PUFA-rich meals than after the SFA- and MUFA-rich meals (P ≤ 0.001). Lipids, glucose, and markers of insulin sensitivity did not differ between the test fats. Our study showed a differential impact of meal fat composition on blood pressure, plasma nitrite, and sICAM-1, but no effect on postprandial FMD or lipemia in postmenopausal women. This trial was registered at www.clinicaltrials.gov as NCT02144454.

Relationship Between 24-Hour Ambulatory Central Systolic Blood Pressure and Left Ventricular Mass: A Prospective Multicenter Study.

PubMed

Weber, Thomas; Wassertheurer, Siegfried; Schmidt-Trucksäss, Arno; Rodilla, Enrique; Ablasser, Cornelia; Jankowski, Piotr; Lorenza Muiesan, Maria; Giannattasio, Cristina; Mang, Claudia; Wilkinson, Ian; Kellermair, Jörg; Hametner, Bernhard; Pascual, Jose Maria; Zweiker, Robert; Czarnecka, Danuta; Paini, Anna; Salvetti, Massimo; Maloberti, Alessandro; McEniery, Carmel

2017-12-01

We investigated the relationship between left ventricular mass and brachial office as well as brachial and central ambulatory systolic blood pressure in 7 European centers. Central systolic pressure was measured with a validated oscillometric device, using a transfer function, and mean/diastolic pressure calibration. M-mode images were obtained by echocardiography, and left ventricular mass was determined by one single reader blinded to blood pressure. We studied 289 participants (137 women) free from antihypertensive drugs (mean age: 50.8 years). Mean office blood pressure was 145/88 mm Hg and mean brachial and central ambulatory systolic pressures were 127 and 128 mm Hg, respectively. Mean left ventricular mass was 93.3 kg/m 2 , and 25.6% had left ventricular hypertrophy. The correlation coefficient between left ventricular mass and brachial office, brachial ambulatory, and central ambulatory systolic pressure was 0.29, 0.41, and 0.47, respectively ( P =0.003 for comparison between brachial office and central ambulatory systolic pressure and 0.32 for comparison between brachial and central ambulatory systolic pressure). The results were consistent for men and women, and young and old participants. The areas under the curve for prediction of left ventricular hypertrophy were 0.618, 0.635, and 0.666 for brachial office, brachial, and central ambulatory systolic pressure, respectively ( P =0.03 for comparison between brachial and central ambulatory systolic pressure). In younger participants, central ambulatory systolic pressure was superior to both other measurements. Central ambulatory systolic pressure, measured with an oscillometric cuff, shows a strong trend toward a closer association with left ventricular mass and hypertrophy than brachial office/ambulatory systolic pressure. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01278732. © 2017 American Heart Association, Inc.

Kidney function and blood pressure in preschool-aged children exposed to cadmium and arsenic - potential alleviation by selenium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skröder, Helena; Hawkesworth, Sophie; Kippler, Maria

Background: Early-life exposure to toxic compounds may cause long-lasting health effects, but few studies have investigated effects of childhood exposure to nephrotoxic metals on kidney and cardiovascular function. Objectives: To assess effects of exposure to arsenic and cadmium on kidney function and blood pressure in pre-school-aged children, and potential protection by selenium. Methods: This cross-sectional study was part of the 4.5 years of age (range: 4.4–5.4 years) follow-up of the children from a supplementation trial in pregnancy (MINIMat) in rural Bangladesh, and nested studies on early-life metal exposures. Exposure to arsenic, cadmium and selenium from food and drinking water wasmore » assessed by concentrations in children's urine, measured by ICP-MS. Kidney function was assessed by the estimated glomerular filtration rate (eGFR, n=1106), calculated from serum cystatin C, and by kidney volume, measured by ultrasound (n=375). Systolic and diastolic blood pressure was measured (n=1356) after five minutes rest. Results: Multivariable-adjusted regression analyzes showed that exposure to cadmium, but not arsenic, was inversely associated with eGFR, particularly in girls. A 0.5 µg/L increase in urinary cadmium among the girls (above spline knot at 0.12) was associated with a decrease in eGFR of 2.6 ml/min/1.73 m{sup 2}, corresponding to 0.2SD (p=0.022). A slightly weaker inverse association with cadmium was also indicated for kidney volume, but no significant associations were found with blood pressure. Stratifying on children's urinary selenium (below or above median of 12.6 µg/L) showed a three times stronger inverse association of U-Cd with eGFR (all children) in the lower selenium stratum (B=−2.8; 95% CI: −5.5, −0.20; p=0.035), compared to those with higher selenium (B=−0.79; 95% CI: −3.0, 1.4; p=0.49). Conclusions: Childhood cadmium exposure seems to adversely affect kidney function, but not blood pressure, in this population of young children in rural Bangladesh. Better selenium status appears to be protective. However, it is important to follow up these children to assess potential long-term consequences of these findings. - Highlights: • Bangladesh has high levels of arsenic and cadmium in drinking water and food • We assessed toxic exposure, kidney and cardiovascular function in Bangladeshi children • Cadmium appeared to decrease estimated glomerular filtration rate in girls • These effects were somewhat alleviated by selenium.« less

Interaction between graviception and carotid baroreflex function in humans during parabolic flight-induced microgravity.

PubMed

Ogoh, Shigehiko; Marais, Michaël; Lericollais, Romain; Denise, Pierre; Raven, Peter B; Normand, Hervé

2018-05-10

The aim of the present study was to assess carotid baroreflex (CBR) during acute changes in otolithic activity in humans. To address this question, we designed a set of experiments to identify the modulatory effects of microgravity on CBR function at a tilt angle of -2{degree sign}, which was identified to minimize changes in central blood volume during parabolic flight. During parabolic flight at 0g and 1g, CBR function curves were modelled from the heart rate (HR) and mean arterial pressure (MAP) responses to rapid pulse trains of neck pressure (NP) and neck suction (NS) ranging from +40 to -80 Torr; CBR control of HR (carotid-HR) and MAP (carotid-MAP) baroreflex function curves, respectively. The maximal gain (G max ) of both carotid-HR and carotid-MAP baroreflex function curves were augmented during microgravity compared to 1g (carotid-HR, -0.53 to -0.80 beats/min/mmHg, P<0.05; carotid-MAP, -0.24 to -0.30 mmHg/mmHg, P<0.05). These findings suggest that parabolic flight-induced acute change of otolithic activity may modify CBR function and identifies that the vestibular system contributes to blood pressure regulation under fluctuations in gravitational forces.

Effects of isoflavone-containing soya protein on ex vivo cholesterol efflux, vascular function and blood markers of CVD risk in adults with moderately elevated blood pressure: a dose-response randomised controlled trial.

PubMed

Richter, Chesney K; Skulas-Ray, Ann C; Fleming, Jennifer A; Link, Christina J; Mukherjea, Ratna; Krul, Elaine S; Kris-Etherton, Penny M

2017-05-01

Emerging CVD risk factors (e.g. HDL function and central haemodynamics) may account for residual CVD risk experienced by individuals who meet LDL-cholesterol and blood pressure (BP) targets. Recent evidence suggests that these emerging risk factors can be modified by polyphenol-rich interventions such as soya, but additional research is needed. This study was designed to investigate the effects of an isoflavone-containing soya protein isolate (delivering 25 and 50 g/d soya protein) on HDL function (i.e. ex vivo cholesterol efflux), macrovascular function and blood markers of CVD risk. Middle-aged adults (n 20; mean age=51·6 (sem 6·6) years) with moderately elevated brachial BP (mean systolic BP=129 (sem 9) mmHg; mean diastolic BP=82·5 (sem 8·4) mmHg) consumed 0 (control), 25 and 50 g/d soya protein in a randomised cross-over design. Soya and control powders were consumed for 6 weeks each with a 2-week compliance break between treatment periods. Blood samples and vascular function measures were obtained at baseline and following each supplementation period. Supplementation with 50 g/d soya protein significantly reduced brachial diastolic BP (-2·3 mmHg) compared with 25 g/d soya protein (Tukey-adjusted P=0·03) but not the control. Soya supplementation did not improve ex vivo cholesterol efflux, macrovascular function or other blood markers of CVD risk compared with the carbohydrate-matched control. Additional research is needed to clarify whether effects on these CVD risk factors depend on the relative health of participants and/or equol producing capacity.

High intensity interval training (HIIT) improves resting blood pressure, metabolic (MET) capacity and heart rate reserve without compromising cardiac function in sedentary aging men.

PubMed

Grace, Fergal; Herbert, Peter; Elliott, Adrian D; Richards, Jo; Beaumont, Alexander; Sculthorpe, Nicholas F

2017-05-13

This study examined a programme of pre-conditioning exercise with subsequent high intensity interval training (HIIT) on blood pressure, echocardiography, cardiac strain mechanics and maximal metabolic (MET) capacity in sedentary (SED) aging men compared with age matched masters athletes (LEX). Using a STROBE compliant observational design, 39 aging male participants (SED; n=22, aged 62.7±5.2yrs) (LEX; n=17, aged=61.1±5.4yrs) were recruited to a study that necessitated three distinct assessment phases; enrolment (Phase A), following pre-conditioning exercise in SED (Phase B), then following 6weeks of HIIT performed once every five days by both groups before reassessment (Phase C). Hemodynamic, echocardiographic and cardiac strain mechanics were obtained at rest and maximal cardiorespiratory and chronotropic responses were obtained at each measurement phase. The training intervention improved systolic, mean arterial blood pressure, rate pressure product and heart rate reserve (each P<0.05) in SED and increased MET capacity in both SED and LEX (P<0.01) which was amplified by HIIT. Echocardiography and cardiac strain measures were unremarkable apart from trivial increase to intra-ventricular septum diastole (IVSd) (P<0.05) and decrease to left ventricular internal dimension diastole (LVId) (P<0.05) in LEX following HIIT. A programme of preconditioning exercise with HIIT induces clinically relevant improvements in blood pressure, rate pressure product and encourages recovery of heart rate reserve in SED, while improving maximal MET capacity in both SED and LEX without inducing any pathological cardiovascular remodeling. These data add to the emerging repute of HIIT as a safe and promising exercise prescription to improve cardiovascular function and metabolic capacity in sedentary aging. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

A two-stage rotary blood pump design with potentially lower blood trauma: a computational study.

PubMed

Thamsen, Bente; Mevert, Ricardo; Lommel, Michael; Preikschat, Philip; Gaebler, Julia; Krabatsch, Thomas; Kertzscher, Ulrich; Hennig, Ewald; Affeld, Klaus

2016-06-15

In current rotary blood pumps, complications related to blood trauma due to shear stresses are still frequently observed clinically. Reducing the rotor tip speed might decrease blood trauma. Therefore, the aim of this project was to design a two-stage rotary blood pump leading to lower shear stresses. Using the principles of centrifugal pumps, two diagonal rotor stages were designed with an outer diameter of 22 mm. The first stage begins with a flow straightener and terminates with a diffusor, while a volute casing behind the second stage is utilized to guide fluid to the outlet. Both stages are combined into one rotating part which is pivoted by cup-socket ruby bearings. Details of the flow field were analyzed employing computational fluid dynamics (CFD). A functional model of the pump was fabricated and the pressure-flow dependency was experimentally assessed. Measured pressure-flow performance of the developed pump indicated its ability to generate adequate pressure heads and flows with characteristic curves similar to centrifugal pumps. According to the CFD results, a pressure of 70 mmHg was produced at a flow rate of 5 L/min and a rotational speed of 3200 rpm. Circumferential velocities could be reduced to 3.7 m/s as compared to 6.2 m/s in a clinically used axial rotary blood pump. Flow fields were smooth with well-distributed pressure fields and comparatively few recirculation or vortices. Substantially smaller volumes were exposed to high shear stresses >150 Pa. Hence, blood trauma might be reduced with this design. Based on these encouraging results, future in vitro investigations to investigate actual blood damage are intended.

Blood Pressure Measurement: Clinic, Home, Ambulatory, and Beyond

PubMed Central

Drawz, Paul E.; Abdalla, Mohamed; Rahman, Mahboob

2014-01-01

Blood pressure has traditionally been measured in the clinic setting using the auscultory method and a mercury sphygmomanometer. Technological advances have led to improvements in measuring clinic blood pressure and allowed for measuring blood pressures outside the clinic. This review outlines various methods for evaluating blood pressure and the clinical utility of each type of measurement. Home blood pressures and 24 hour ambulatory blood pressures have improved our ability to evaluate risk for target organ damage and hypertension related morbidity and mortality. Measuring home blood pressures may lead to more active participation in health care by patients and has the potential to improve blood pressure control. Ambulatory blood pressure monitoring enables the measuring nighttime blood pressures and diurnal changes, which may be the most accurate predictors of risk associated with elevated blood pressure. Additionally, reducing nighttime blood pressure is feasible and may be an important component of effective antihypertensive therapy. Finally, estimating central aortic pressures and pulse wave velocity are two of the newer methods for assessing blood pressure and hypertension related target organ damage. PMID:22521624

Does a colour-coded blood pressure diary improve blood pressure control for patients in general practice: the CoCo trial.

PubMed

Steurer-Stey, Claudia; Zoller, Marco; Chmiel Moshinsky, Corinne; Senn, Oliver; Rosemann, Thomas

2010-04-14

Insufficient blood pressure control is a frequent problem despite the existence of effective treatment. Insufficient adherence to self-monitoring as well as to therapy is a common reason. Blood pressure self-measurement at home (Home Blood Pressure Measurement, HBPM) has positive effects on treatment adherence and is helpful in achieving the target blood pressure. Only a few studies have investigated whether adherence to HBPM can be improved through simple measures resulting also in better blood pressure control. Improvement of self-monitoring and improved blood pressure control by using a new colour-coded blood pressure diary. Change in systolic and/or diastolic blood pressure 6 months after using the new colour-coded blood pressure diary.Secondary outcome: Adherence to blood pressure self-measurement (number of measurements/entries). Randomised controlled study. 138 adult patients in primary care with uncontrolled hypertension despite therapy. The control group uses a conventional blood pressure diary; the intervention group uses the new colour-coded blood pressure diary (green, yellow, red according a traffic light system). EXPECTED RESULTS/CONCLUSION: The visual separation and entries in three colour-coded areas reflecting risk (green: blood pressure in the target range 140/>90 mmHg, red: blood pressure in danger zone > 180 mmHg/>110 mmHg) lead to better self-monitoring compared with the conventional (non-colour-coded) blood pressure booklet. The colour-coded, visualised information supports improved perception (awareness and interpretation) of blood pressure and triggers correct behaviour, in the means of improved adherence to the recommended treatment as well as better communication between patients and doctors resulting in improved blood pressure control. ClinicalTrials.gov ID NCT01013467.

Renal cytokines improve early after bariatric surgery.

PubMed

Bueter, M; Dubb, S S; Gill, A; Joannou, L; Ahmed, A; Frankel, A H; Tam, F W K; le Roux, C W

2010-12-01

Bariatric surgery has been suggested to improve arterial hypertension and renal function. This prospective controlled observational study aimed to investigate changes in renal inflammation, renal function and arterial blood pressure before and after bariatric surgery. Blood pressure was measured, and urine and blood samples were collected from 34 morbidly obese patients before and 4 weeks after bariatric surgery. Serum levels of cystatin C, creatinine, albumin, cholesterol and C-reactive protein (CRP) were measured, along with urinary cytokine/creatinine ratios for macrophage migration inhibitory factor (MIF), monocyte chemotactic protein (MCP) 1, chemokine ligand (CCL) 18 and CCL-15. Mean(s.e.m.) bodyweight dropped from 124·1(2·6) to 114·8(2·4) kg (P < 0·001) and mean arterial blood pressure decreased from 105·7(1·8) to 95·5(1·2) mmHg (P < 0·001) in 4 weeks. Systemic and urinary inflammatory markers improved, with a reduction in serum CRP level (P < 0·001), and decreased urinary MIF/creatinine (P < 0·001), MCP-1/creatinine (P < 0·001) and CCL-18/creatinine (P = 0·003) ratios. In contrast, urinary CCL-15/creatinine ratios did not change and the glomerular filtration rate, measured by serum cystatin C, was unchanged (P = 0·615). Surgically induced weight loss contributed to a decrease in blood pressure and markers of renal inflammation. The reduced levels of CRP and urinary cytokines suggest that bariatric surgery attenuates systemic and renal inflammatory status. Copyright © 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

High blood pressure and visual sensitivity

NASA Astrophysics Data System (ADS)

Eisner, Alvin; Samples, John R.

2003-09-01

The study had two main purposes: (1) to determine whether the foveal visual sensitivities of people treated for high blood pressure (vascular hypertension) differ from the sensitivities of people who have not been diagnosed with high blood pressure and (2) to understand how visual adaptation is related to standard measures of systemic cardiovascular function. Two groups of middle-aged subjects-hypertensive and normotensive-were examined with a series of test/background stimulus combinations. All subjects met rigorous inclusion criteria for excellent ocular health. Although the visual sensitivities of the two subject groups overlapped extensively, the age-related rate of sensitivity loss was, for some measures, greater for the hypertensive subjects, possibly because of adaptation differences between the two groups. Overall, the degree of steady-state sensitivity loss resulting from an increase of background illuminance (for 580-nm backgrounds) was slightly less for the hypertensive subjects. Among normotensive subjects, the ability of a bright (3.8-log-td), long-wavelength (640-nm) adapting background to selectively suppress the flicker response of long-wavelength-sensitive (LWS) cones was related inversely to the ratio of mean arterial blood pressure to heart rate. The degree of selective suppression was also related to heart rate alone, and there was evidence that short-term changes of cardiovascular response were important. The results suggest that (1) vascular hypertension, or possibly its treatment, subtly affects visual function even in the absence of eye disease and (2) changes in blood flow affect retinal light-adaptation processes involved in the selective suppression of the flicker response from LWS cones caused by bright, long-wavelength backgrounds.

Acute treatment of hypertensive crisis with nifedipine.

PubMed Central

Huysmans, F T; Sluiter, H E; Thien, T A; Koene, R A

1983-01-01

Ten patients with a hypertensive crisis and a decreased renal function were treated with 10 (n = 7) or 20 (n = 3) mg nifedipine sublingually. Blood pressure was reduced in 60 min from 211 +/- 4/134 +/- 5 to 172 +/- 6/107 +/- 6 mm Hg. The decrease of blood pressure was accompanied by a rise in heart rate from 83 +/- 6 to 98 +/- 5 beats/min. In all seven patients with an encephalopathy signs of this complication were reduced. No serious side-effects were observed. PMID:6661359

Conventional versus automated measurement of blood pressure in primary care patients with systolic hypertension: randomised parallel design controlled trial

PubMed Central

Godwin, Marshall; Dawes, Martin; Kiss, Alexander; Tobe, Sheldon W; Grant, F Curry; Kaczorowski, Janusz

2011-01-01

Objective To compare the quality and accuracy of manual office blood pressure and automated office blood pressure using the awake ambulatory blood pressure as a gold standard. Design Multi-site cluster randomised controlled trial. Setting Primary care practices in five cities in eastern Canada. Participants 555 patients with systolic hypertension and no serious comorbidities under the care of 88 primary care physicians in 67 practices in the community. Interventions Practices were randomly allocated to either ongoing use of manual office blood pressure (control group) or automated office blood pressure (intervention group) using the BpTRU device. The last routine manual office blood pressure (mm Hg) was obtained from each patient’s medical record before enrolment. Office blood pressure readings were compared before and after enrolment in the intervention and control groups; all readings were also compared with the awake ambulatory blood pressure. Main outcome measure Difference in systolic blood pressure between awake ambulatory blood pressure minus automated office blood pressure and awake ambulatory blood pressure minus manual office blood pressure. Results Cluster randomisation allocated 31 practices (252 patients) to manual office blood pressure and 36 practices (303 patients) to automated office blood pressure measurement. The most recent routine manual office blood pressure (149.5 (SD 10.8)/81.4 (8.3)) was higher than automated office blood pressure (135.6 (17.3)/77.7 (10.9)) (P<0.001). In the control group, routine manual office blood pressure before enrolment (149.9 (10.7)/81.8 (8.5)) was reduced to 141.4 (14.6)/80.2 (9.5) after enrolment (P<0.001/P=0.01), but the reduction in the intervention group from manual office to automated office blood pressure was significantly greater (P<0.001/P=0.02). On the first study visit after enrolment, the estimated mean difference for the intervention group between the awake ambulatory systolic/diastolic blood pressure and automated office blood pressure (−2.3 (95% confidence interval −0.31 to −4.3)/−3.3 (−2.7 to −4.4)) was less (P=0.006/P=0.26) than the difference in the control group between the awake ambulatory blood pressure and the manual office blood pressure (−6.5 (−4.3 to −8.6)/−4.3 (−2.9 to −5.8)). Systolic/diastolic automated office blood pressure showed a stronger (P<0.001) within group correlation (r=0.34/r=0.56) with awake ambulatory blood pressure after enrolment compared with manual office blood pressure versus awake ambulatory blood pressure before enrolment (r=0.10/r= 0.40); the mean difference in r was 0.24 (0.12 to 0.36)/0.16 (0.07 to 0.25)). The between group correlation comparing diastolic automated office blood pressure and awake ambulatory blood pressure (r=0.56) was stronger (P<0.001) than that for manual office blood pressure versus awake ambulatory blood pressure (r=0.30); the mean difference in r was 0.26 (0.09 to 0.41). Digit preference with readings ending in zero was substantially reduced by use of automated office blood pressure. Conclusion In compliant, otherwise healthy, primary care patients with systolic hypertension, introduction of automated office blood pressure into routine primary care significantly reduced the white coat response compared with the ongoing use of manual office blood pressure measurement. The quality and accuracy of automated office blood pressure in relation to the awake ambulatory blood pressure was also significantly better when compared with manual office blood pressure. Trial registration Clinical trials NCT 00214053. PMID:21300709

[Association between higher blood pressure level in children and adult blood pressure: 17 years follow-up results].

PubMed

Mu, Jian-Jun; Liu, Zhi-Quan; Yang, Jun; Ren, Jie; Liu, Wei-Min; Xu, Xiang-Lin; Xiong, Su-E

2008-03-01

Essential hypertension may begin at childhood. The aim of this study is to identify the risk factors of hypertension and detect the evolvement tracking of blood pressure in childhood. In this study, we followed up blood pressure changes in 4623 school children (6 - 15 years-old) from 1987 to 2005 in Hanzhong rural area. A total of 152 children were grouped to higher blood pressure group [systolic blood pressure (P(SBP)) >or= 75(th) (P(75))] and 140 children grouped to normal blood pressure group [P(SBP) < 50(th) (P(50))] and their blood pressure were re-measure 18-years later. The total follow-up rate was 70.2%. Follow-up blood pressure was significantly higher in higher blood pressure group at baseline than that in normal blood pressure group at baseline (P < 0.05). The hypertension rate at follow up was significantly higher in higher blood pressure group at baseline than that in normal blood pressure group at baseline (28.0% vs. 4.1%, P < 0.01). The risk for hypertension was 6.88 greater in higher blood pressure group at baseline than that in normal blood pressure group at baseline. Higher blood pressure at childhood is a risk of developing hypertension at adulthood.

Central arterial characteristics of gout patients with chronic kidney diseases.

PubMed

Celik, Gulperi; Yilmaz, Sema; Kebapcilar, Levent; Gundogdu, Ali

2017-05-01

The aim of this study was to investigate the relationship between central blood pressure, arterial stiffness parameters and renal function parameters in gout patients with chronic kidney disease (CKD) and without CKD. The study enrolled 48 gout patients and 32 control subjects. Central blood pressure, arterial stiffness parameters and renal function parameters in gout patients were investigated. The vascular measurements were performed with an arteriograph. Of the gout patients, 40.1% had CKD. The 24-h pulse pressure (PP) (P < 0.001), central systolic blood pressure (SBP) (P < 0.001), central diastolic blood pressure (DBP) (P < 0.001), cardiac output (CO) (P < 0.001) and peripheral resistance (P = 0.004) were significantly higher in the all patients with gout compared to healthy control subjects. Moreover, when the gout patients with and without CKD were compared, the gout patients with CKD had higher 24-h PP (P = 0.009), 24-h augmentation index standardized to a heart rate of 75 beats per min (AIx@75) (P < 0.023), daytime PP (P = 0.001), daytime AIx@75 (P = 0.027), and nighttime PP (P = 0.035) than the gout patients without CKD. In our study, gout patients with CKD had worse and more emphasized evidence of arterial stiffness than gout patients without CKD. Further investigations with large sample sizes are needed to evaluate the effect of CKD on the arterial stiffness of gout patients. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Diurnal blood pressure changes.

PubMed

Asayama, Kei; Satoh, Michihiro; Kikuya, Masahiro

2018-05-23

The definition of diurnal blood pressure changes varies widely, which can be confusing. Short-term blood pressure variability during a 24-h period and the dipping status of diurnal blood pressure can be captured by ambulatory blood pressure monitoring, and these metrics are reported to have prognostic significance for cardiovascular complications. Morning blood pressure surge also indicates this risk, but its effect may be limited to populations with specific conditions. Meanwhile, the combined use of conventional office blood pressure and out-of-office blood pressure allows us to identify people with white-coat and masked hypertension. Current home devices can measure nocturnal blood pressure during sleep more conveniently than ambulatory monitoring; however, we should pay attention to blood pressure measurement conditions regardless of whether they are in a home, ambulatory, or office setting. The relatively poor reproducibility of diurnal blood pressure changes, including the nocturnal fall of blood pressure, is another underestimated issue to be addressed. Although information on diurnal blood pressure changes is expected to be used more effectively in the future, we should also keep in mind that blood pressure levels have remained central to the primary and secondary prevention of blood pressure-related cardiovascular diseases in clinical practice.

Testosterone receptor blockade after trauma-hemorrhage improves cardiac and hepatic functions in males.

PubMed

Remmers, D E; Wang, P; Cioffi, W G; Bland, K I; Chaudry, I H

1997-12-01

Although studies have shown that testosterone receptor blockade with flutamide after hemorrhage restores the depressed immune function, it remains unknown whether administration of flutamide following trauma and hemorrhage and resuscitation has any salutary effects on the depressed cardiovascular and hepatocellular functions. To study this, male rats underwent a laparotomy (representing trauma) and were then bled and maintained at a mean arterial pressure (MAP) of 40 mmHg until the animals could not maintain this pressure. Ringer lactate was given to maintain a MAP of 40 mmHg until 40% of the maximal shed blood volume was returned in the form of Ringer lactate. The rats were then resuscitated with four times the shed blood volume in the form of Ringer lactate over 60 min. Flutamide (25 mg/kg) or an equal volume of the vehicle propanediol was injected subcutaneously 15 min before the end of resuscitation. Various in vivo heart performance parameters (e.g., maximal rate of the pressure increase or decrease), cardiac output, and hepatocellular function (i.e., the maximum velocity and the overall efficiency of indocyanine green clearance) were determined at 20 h after resuscitation. Additionally, hepatic microvascular blood flow (HMBF) was determined using a laser Doppler flowmeter. The results indicate that left ventricular performance, cardiac output, HMBF, and hepatocellular function decreased significantly at 20 h after the completion of trauma, hemorrhage, and resuscitation. Administration of the testosterone receptor blocker flutamide, however, significantly improved cardiac performance, HMBF, and hepatocellular function. Thus flutamide appears to be a novel and useful adjunct for improving cardiovascular and hepatocellular functions in males following trauma and hemorrhagic shock.

Ambulatory Blood Pressure Monitoring in Clinical Practice: A Review

PubMed Central

Viera, Anthony J.; Shimbo, Daichi

2016-01-01

Ambulatory blood pressure monitoring offers the ability to collect blood pressure readings several times an hour across a 24-hour period. Ambulatory blood pressure monitoring facilitates the identification of white-coat hypertension, the phenomenon whereby certain individuals who are not on antihypertensive medication show elevated blood pressure in a clinical setting but show non-elevated blood pressure averages when assessed by ambulatory blood pressure monitoring. Additionally, readings can be segmented into time windows of particular interest, e.g., mean daytime and nighttime values. During sleep, blood pressure typically decreases, or dips, such that mean sleep blood pressure is lower than mean awake blood pressure. A non-dipping pattern and nocturnal hypertension are strongly associated with increased cardiovascular morbidity and mortality. Approximately 70% of individuals dip ≥10% at night, while 30% have non-dipping patterns, when blood pressure remains similar to daytime average, or occasionally rises above daytime average. The various blood pressure categorizations afforded by ambulatory blood pressure monitoring are valuable for clinical management of high blood pressure since they increase accuracy for diagnosis and the prediction of cardiovascular risk. PMID:25107387

Effects of living at two ambient temperatures on 24-h blood pressure and neuroendocrine function among obese and non-obese humans: a pilot study

NASA Astrophysics Data System (ADS)

Kanikowska, Dominika; Sato, Maki; Iwase, Satoshi; Shimizu, Yuuki; Nishimura, Naoki; Inukai, Yoko; Sugenoya, Junichi

2013-05-01

The effects of environmental temperature on blood pressure and hormones in obese subjects in Japan were compared in two seasons: summer vs winter. Five obese (BMI, 32 ± 5 kg/m2) and five non-obese (BMI, 23 ±3 kg/m2) men participated in this experiment at latitude 35°10' N and longitude 136°57.9' E. The average environmental temperature was 29 ± 1 °C in summer and 3 ± 1 °C in winter. Blood samples were analyzed for leptin, ghrelin, catecholamines, thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), total cholesterol, triglycerides, insulin and glucose. Blood pressure was measured over the course of 24 h in summer and winter. A Japanese version of the Profile of Mood States (POMS) questionnaire was also administered each season. Systolic and diastolic blood pressures in obese men were significantly higher in winter (lower environmental temperatures) than in summer (higher environmental temperatures). Noradrenaline and dopamine concentrations were also significantly higher at lower environmental temperatures in obese subjects, but ghrelin, TSH, fT3, fT4, insulin and glucose were not significantly different in summer and winter between obese and non-obese subjects. Leptin, total cholesterol and triglyceride concentrations were significantly higher in winter in obese than non-obese men. Results from the POMS questionnaire showed a significant rise in Confusion at lower environmental temperatures (winter) in obese subjects. In this pilot study, increased blood pressure may have been due to increased secretion of noradrenaline in obese men in winter, and the results suggest that blood pressure control in obese men is particularly important in winter.

The impact of ocular hemodynamics and intracranial pressure on intraocular pressure during acute gravitational changes.

PubMed

Nelson, Emily S; Mulugeta, Lealem; Feola, Andrew; Raykin, Julia; Myers, Jerry G; Samuels, Brian C; Ethier, C Ross

2017-08-01

Exposure to microgravity causes a bulk fluid shift toward the head, with concomitant changes in blood volume/pressure, and intraocular pressure (IOP). These and other factors, such as intracranial pressure (ICP) changes, are suspected to be involved in the degradation of visual function and ocular anatomical changes exhibited by some astronauts. This is a significant health concern. Here, we describe a lumped-parameter numerical model to simulate volume/pressure alterations in the eye during gravitational changes. The model includes the effects of blood and aqueous humor dynamics, ICP, and IOP-dependent ocular compliance. It is formulated as a series of coupled differential equations and was validated against four existing data sets on parabolic flight, body inversion, and head-down tilt (HDT). The model accurately predicted acute IOP changes in parabolic flight and HDT, and was satisfactory for the more extreme case of inversion. The short-term response to the changing gravitational field was dominated by ocular blood pressures and compliance, while longer-term responses were more dependent on aqueous humor dynamics. ICP had a negligible effect on acute IOP changes. This relatively simple numerical model shows promising predictive capability. To extend the model to more chronic conditions, additional data on longer-term autoregulation of blood and aqueous humor dynamics are needed. NEW & NOTEWORTHY A significant percentage of astronauts present anatomical changes in the posterior eye tissues after spaceflight. Hypothesized increases in ocular blood volume and intracranial pressure (ICP) in space have been considered to be likely factors. In this work, we provide a novel numerical model of the eye that incorporates ocular hemodynamics, gravitational forces, and ICP changes. We find that changes in ocular hemodynamics govern the response of intraocular pressure during acute gravitational change. Copyright © 2017 the American Physiological Society.

Responses of aortic depressor nerve-evoked neurones in rat nucleus of the solitary tract to changes in blood pressure

PubMed Central

Zhang, Jing; Mifflin, Steven W

2000-01-01

Using electrophysiological techniques, the discharge of neurones in the nucleus of the solitary tract (NTS) receiving aortic depressor nerve (ADN) inputs was examined during blood pressure changes induced by I.V. phenylephrine or nitroprusside in anaesthetized, paralysed and artificially ventilated rats. Various changes in discharge rate were observed during phenylephrine-induced blood pressure elevations: an increase (n = 38), a decrease (n = 5), an increase followed by a decrease (n = 4) and no response (n = 11). In cells receiving a monosynaptic ADN input (MSNs), the peak discharge frequency response was correlated to the rate of increase in mean arterial pressure (P < 0.01) but was not correlated to the absolute increase in blood pressure. The peak discharge frequency response of cells receiving a polysynaptic ADN input (PSNs) was correlated to neither the absolute increase in blood pressure nor the rate of increase in mean arterial pressure. Diverse changes in discharge rate were observed during nitroprusside-induced reductions in blood pressure: an increase (n = 3), a decrease (n = 10), an increase followed by a decrease (n = 3) and no response (n = 6). Reductions in pressure of 64 ± 2 mmHg produced weak reductions in spontaneous discharge of 1.3 ± 0.9 Hz and only totally abolished spontaneous discharge in one neurone. These response patterns of NTS neurones during changes in arterial pressure suggest that baroreceptor inputs are integrated differently in MSNs compared to PSNs. The sensitivity of MSNs to the rate of change of pressure provides a mechanism for the rapid regulation of cardiovascular function. The lack of sensitivity to the mean level of a pressure increase in both MSNs and PSNs suggests that steady-state changes in pressure are encoded by the number of active neurones and not graded changes in the discharge of individual neurones. Both MSNs and PSNs receive tonic excitatory inputs from the arterial baroreceptors; however, these tonic inputs appear to be insufficient to totally account for their spontaneous discharge. PMID:11101652

Inherited renal tubulopathies associated with metabolic alkalosis: effects on blood pressure.

PubMed

Ariceta, Gema; Rodríguez-Soriano, Juan

2006-11-01

Inherited tubular disorders associated with metabolic alkalosis are caused by several gene mutations encoding different tubular transporters responsible for NaCl renal handling. Body volume and renin-angiotensin-aldosterone system status are determined by NaCl reabsorption in the distal nephron. Two common hallmarks in affected individuals: hypokalemia and normal / high blood pressure, support the differential diagnosis. Bartter's syndrome, characterized by hypokalemia and normal blood pressure, is a heterogenic disease caused by the loss of function of SLC12A1 (type 1), KCNJ1 (type 2), CLCNKB (type 3), or BSND genes (type 4). As a result, patients present with renal salt wasting and hypercalciuria. Gitelman's syndrome is caused by the loss of funcion of the SLC12A3 gene and may resemble Bartter's syndrome, though is associated with the very low urinary calcium. Liddle's syndrome, also with similar phenotype but with hypertension, is produced by the gain of function of the SNCC1B or SNCC1G genes, and must be distinguished from other entities of inherited hypertension such as Apparently Mineralocorticoid Excess, of glucocorticoid remediable hypertension.

The PILI@Work Program: a translation of the diabetes prevention program to Native Hawaiian-serving worksites in Hawai'i.

PubMed

Townsend, Claire K M; Miyamoto, Robin E S; Antonio, Mapuana; Zhang, Guangxing; Paloma, Diane; Basques, DeAnna; Braun, Kathryn L; Kaholokula, Joseph Keawe'aimoku

2016-06-01

A previously translated Diabetes Prevention Program Lifestyle Intervention (DPP-LI) was adapted for delivery as a worksite-based intervention, called PILI@Work, to address obesity disparities in Native Hawaiians/Pacific Islanders. This study examined the effectiveness of PILI@Work and factors associated with weight loss at post-intervention. Overweight/obese employees of 15 Native Hawaiian-serving organizations received the 3-month component of PILI@Work. Assessments included weight, systolic/diastolic blood pressure, physical activity and functioning, fat intake, locus of weight control, social support, and self-efficacy. Weight, systolic/diastolic blood pressure, physical functioning, physical activity frequency, fat intake, family support, and eating self-efficacy improved from pre- to post-intervention. Regression analysis indicated that worksite type, decreased diastolic blood pressure, increased physical activity, and more internalized locus of weight control were significantly associated with 3-month weight loss. PILI@Work initiated weight loss in Native Hawaiians/Pacific Islanders. DPP-LI translated to worksite settings and tailored for specific populations can be effective for addressing obesity.

Exercise training by individuals with predialysis renal failure: cardiorespiratory endurance, hypertension, and renal function.

PubMed

Boyce, M L; Robergs, R A; Avasthi, P S; Roldan, C; Foster, A; Montner, P; Stark, D; Nelson, C

1997-08-01

The purpose of this study was to determine the effects of 4 months of exercise training (ET) on cardiorespiratory function and endurance, blood pressure, muscle strength, hematology, blood lipids, and renal function in individuals with chronic renal failure (CRF) who were not yet on dialysis. Sixteen subjects were recruited to volunteer for participation in this study, but only eight completed all study phases. Subjects were first evaluated before and after a 2-month baseline (BL1 and BL2), after 4 months of ET, and again after 2 months of detraining (DT). ET did not change hematology, blood lipids, or echocardiographic measurements of left ventricular function and mass. Resting systolic and diastolic blood pressures decreased significantly from BL after the ET (146 +/- 15.7/87 +/- 9 mm Hg to 124 +/- 17.5/78 +/- 9.5 mm Hg; P < 0.02), and then increased significantly after DT (139 +/- 14.7 mm Hg and 87 +/- 9.9 mm Hg; P < 0.01). Peak oxygen consumption (pVO2) changed significantly during the study (1.3 +/- 0.3 L/min, 1.5 +/- 0.3 L/min, and 1.4 +/- 0.3 L/min for BL2, ET, and DT, respectively; P < 0.02), as did the VO2 at the ventilatory threshold (0.65 +/- 0.18 L/min, 0.92 +/- 0.19 L/min, and 0.68 +/- 0.23 L/min for BL2, ET, and DT, respectively; P < 0.01). Knee flexion peak torque increased after ET (43.4 +/- 25.6 Nm to 51.0 +/- 30.5 Nm; P < 0.02). GFR, as measured by creatinine clearance, continued to deteriorate during the course of the study (25.3 +/- 12.0 mL/min, 21.8 +/- 13.2 mL/min, and 21.8 +/- 13.2 mL/min for BL2, ET, and DT, respectively; P < 0.001). Individuals with predialysis CRF who undergo ET improve in functional aerobic capacity, muscular strength, and blood pressure.

Cynicism, anger and cardiovascular reactivity during anger recall and human-computer interaction.

PubMed

Why, Yong Peng; Johnston, Derek W

2008-06-01

Cynicism moderated by interpersonal anger has been found to be related to cardiovascular reactivity. This paper reports two studies; Study 1 used an Anger Recall task, which aroused interpersonal anger, while participants in Study 2 engaged in a multitasking computer task, which aroused non-interpersonal anger via systematic manipulation of the functioning of the computer mouse. The Cynicism by State Anger interaction was significant for blood pressure arousal in Study 2 but not for Study 1: in Study 2, when State Anger was high, cynicism was positively related to blood pressure arousal but when State Anger was low, cynicism was negatively related to blood pressure arousal. For both studies, when State Anger was low, cynicism was positively related to cardiac output arousal and negatively related to vascular arousal. The results suggest that Cynicism-State Anger interaction can be generalised to non-social anger-arousing situations for hemodynamic processes but blood pressure reactivity is task-dependent. The implication for the role of job control and cardiovascular health during human-computer interactions is discussed.

Social support is associated with blood pressure responses in parents caring for children with developmental disabilities.

PubMed

Gallagher, Stephen; Whiteley, Jenny

2012-01-01

The present study tested whether parents caring for children with developmental disabilities would have higher blood pressure compared to parents of typically developing children (controls). It also examined the psychosocial factors underlying this observation. Thirty-five parents of children with developmental disability and thirty controls completed standard measures of perceived stress, child challenging behaviours and social support and wore an ambulatory blood pressure (BP) monitor throughout the day, for one day. Relative to controls, parents caring for children with developmental disabilities reported poorer psychosocial functioning and had a higher mean systolic BP. Of the psychosocial predictors, only social support was found to be predictive. Moreover, variations in social support accounted for some of the between group differences with the β for parental group attenuated from .42 to .34 in regression analyses. It appears that social support may influence blood pressure responses in parental caregivers. Finally, our findings underscore the importance of providing psychosocial interventions to improve the health of family caregivers. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis and blood pressure lowering activity of benzylic ethers of 2-diethylaminoethanol and a related diamine.

PubMed

El-Antably, S M; Soine, T O; Shaath, N A; Gupta, P K

1975-08-01

Based upon the unpublished finding that 3'-hydroxy-4'-(beta-diethylaminoethoxy)-3',4'-dihydroseselin possessed a potent blood pressure lowering effect in the cat at a dose of 1 mg/kg, the present study examined the activities of several related compounds. These compounds were derived by dissection of the parent compound to give four benzylic ethers of 2-diethylaminoethanol and a diamine, derived by replacing the ether oxygen of the parent compound with an N--CH3 function. The simplest compounds were the benzyl and 2,6-dimethoxybenzyl ethers of the aminoalcohol. Closely related to the benzyl compound was a congener with a hydroxymethyl group on the benzylic carbon. The beta-diethylaminoethyl ether of 4-chromanol was the most complex of the ethers. The blood pressure measurements were carried out on male cats and compared to papaverine hydrochloride as a standard. In all cases, the most potent blood pressure lowering activity resided in the parent compound, which was not greatly superior to the diamine but substantially more active than the other compounds.

The role of dietary potassium in hypertension and diabetes.

PubMed

Ekmekcioglu, Cem; Elmadfa, Ibrahim; Meyer, Alexa L; Moeslinger, Thomas

2016-03-01

Potassium is an essential mineral which plays major roles for the resting membrane potential and the intracellular osmolarity. In addition, for several years, it has been known that potassium also affects endothelial and vascular smooth muscle functions and it has been repeatedly shown that an increase in potassium intake shifts blood pressure to a more preferable level. Meanwhile, the blood pressure lowering effects of potassium were presented in several intervention trials and summarized in a handful of meta-analyses. Furthermore, accumulating epidemiological evidence from, especially, the last decade relates low dietary potassium intake or serum potassium levels to an increased risk for insulin resistance or diabetes. However, intervention trials are required to confirm this association. So, in addition to reduction of sodium intake, increasing dietary potassium intake may positively affect blood pressure and possibly also glucose metabolism in many populations. This concise review not only summarizes the studies linking potassium to blood pressure and diabetes but also discusses potential mechanisms involved, like vascular smooth muscle relaxation and endothelium-dependent vasodilation or stimulation of insulin secretion in pancreatic β-cells, respectively.

Pharmacological modulation of platelet function in hypertension.

PubMed

Blann, Andrew D; Nadar, Sunil; Lip, Gregory Y H

2003-07-01

Platelets exert a considerable influence on human morbidity and mortality. The rationale for their study in hypertension follows the observation that the major consequences of hypertension are stroke and myocardial infarction. However, the etiology of these consequences in hypertension is, paradoxically, not hemorrhagic (as might be expected from the effects of high blood pressure), but occlusive, with thrombus being the culprit lesion. Mechanisms of platelet activation include high shear force, activation of the renin-angiotensin system, endothelial changes, and the presence of comorbidity, such as atrial fibrillation. The treatment of high blood pressure brings about a reversal of the changes seen in the cell. This could be in part due to the direct effect of the drug on the megakaryocyte and/or the platelets themselves, or it might simply be due to the reduction in blood pressure. Some drugs, such as calcium channel antagonists and angiotensin II receptor blockers, however, might have direct effects on platelet biochemistry other than reducing blood pressure. Finally, antiplatelet drugs are becoming an important part of the management of high-risk hypertensives, which aim to minimize vascular complications.

Antihypertensive treatment differentially affects vascular sphingolipid biology in spontaneously hypertensive rats.

PubMed

Spijkers, Léon J A; Janssen, Ben J A; Nelissen, Jelly; Meens, Merlijn J P M T; Wijesinghe, Dayanjan; Chalfant, Charles E; De Mey, Jo G R; Alewijnse, Astrid E; Peters, Stephan L M

2011-01-01

We have previously shown that essential hypertension in humans and spontaneously hypertensive rats (SHR), is associated with increased levels of ceramide and marked alterations in sphingolipid biology. Pharmacological elevation of ceramide in isolated carotid arteries of SHR leads to vasoconstriction via a calcium-independent phospholipase A(2), cyclooxygenase-1 and thromboxane synthase-dependent release of thromboxane A(2). This phenomenon is almost absent in vessels from normotensive Wistar Kyoto (WKY) rats. Here we investigated whether lowering of blood pressure can reverse elevated ceramide levels and reduce ceramide-mediated contractions in SHR. For this purpose SHR were treated for 4 weeks with the angiotensin II type 1 receptor antagonist losartan or the vasodilator hydralazine. Both drugs decreased blood pressure equally (SBP untreated SHR: 191±7 mmHg, losartan: 125±5 mmHg and hydralazine: 113±14 mmHg). The blood pressure lowering was associated with a 20-25% reduction in vascular ceramide levels and improved endothelial function of isolated carotid arteries in both groups. Interestingly, losartan, but not hydralazine treatment, markedly reduced sphingomyelinase-induced contractions. While both drugs lowered cyclooxygenase-1 expression, only losartan and not hydralazine, reduced the endothelial expression of calcium-independent phospholipase A(2). The latter finding may explain the effect of losartan treatment on sphingomyelinase-induced vascular contraction. In summary, this study corroborates the importance of sphingolipid biology in blood pressure control and specifically shows that blood pressure lowering reduces vascular ceramide levels in SHR and that losartan treatment, but not blood pressure lowering per se, reduces ceramide-mediated arterial contractions.

Antihypertensive Treatment Differentially Affects Vascular Sphingolipid Biology in Spontaneously Hypertensive Rats

PubMed Central

Spijkers, Léon J. A.; Janssen, Ben J. A.; Nelissen, Jelly; Meens, Merlijn J. P. M. T.; Wijesinghe, Dayanjan; Chalfant, Charles E.; De Mey, Jo G. R.; Alewijnse, Astrid E.; Peters, Stephan L. M.

2011-01-01

Background We have previously shown that essential hypertension in humans and spontaneously hypertensive rats (SHR), is associated with increased levels of ceramide and marked alterations in sphingolipid biology. Pharmacological elevation of ceramide in isolated carotid arteries of SHR leads to vasoconstriction via a calcium-independent phospholipase A2, cyclooxygenase-1 and thromboxane synthase-dependent release of thromboxane A2. This phenomenon is almost absent in vessels from normotensive Wistar Kyoto (WKY) rats. Here we investigated whether lowering of blood pressure can reverse elevated ceramide levels and reduce ceramide-mediated contractions in SHR. Methods and Findings For this purpose SHR were treated for 4 weeks with the angiotensin II type 1 receptor antagonist losartan or the vasodilator hydralazine. Both drugs decreased blood pressure equally (SBP untreated SHR: 191±7 mmHg, losartan: 125±5 mmHg and hydralazine: 113±14 mmHg). The blood pressure lowering was associated with a 20–25% reduction in vascular ceramide levels and improved endothelial function of isolated carotid arteries in both groups. Interestingly, losartan, but not hydralazine treatment, markedly reduced sphingomyelinase-induced contractions. While both drugs lowered cyclooxygenase-1 expression, only losartan and not hydralazine, reduced the endothelial expression of calcium-independent phospholipase A2. The latter finding may explain the effect of losartan treatment on sphingomyelinase-induced vascular contraction. Conclusion In summary, this study corroborates the importance of sphingolipid biology in blood pressure control and specifically shows that blood pressure lowering reduces vascular ceramide levels in SHR and that losartan treatment, but not blood pressure lowering per se, reduces ceramide-mediated arterial contractions. PMID:22195025

Childhood poverty and blood pressure reactivity to and recovery from an acute stressor in late adolescence: the mediating role of family conflict.

PubMed

Evans, Gary W; Exner-Cortens, Deinera; Kim, Pilyoung; Bartholomew, Daniel

2013-09-01

Childhood deprivation is inimical to health throughout the life course. Early experiences of stress could play a role in health inequalities. An important aspect of childhood poverty that has not received much attention is cardiovascular reactivity to and recovery from acute stressors. Piecewise, multilevel growth curve regression was used to examine blood pressure reactivity to and recovery from a mental arithmetic task among late adolescents (mean [standard deviation] = 17.3 [1.0] years, n = 185) as a function of early childhood poverty (9 years). We also tested whether exposure to family conflict at age 13 years mediated expected linkages between childhood poverty and adolescent blood pressure reactivity and recovery to an acute stressor. Blood pressure reactivity was unaffected by household income during childhood, but late adolescents with lower household income during childhood showed slower systolic (b = -0.29, p = .004) and diastolic (b = -0.19, p = .002) recovery. These results include age and sex as statistical covariates. The significant poverty impact on systolic but not on diastolic blood pressure recovery was mediated by exposure to family conflict (95% confidence interval = - 0.1400 to - 0.0012). We show that late adolescents who grew up in poverty have delayed blood pressure recovery from an acute stressor. Furthermore, childhood exposure to family conflict, a well-documented component of early childhood deprivation, accounted for some of the adverse effects of childhood poverty on stressor recovery among these adolescents. We discuss the importance of considering physiological stress accompanying early experiences of deprivation in thinking about health inequalities.

Azilsartan: a newly approved angiotensin II receptor blocker.

PubMed

Lam, Sum

2011-01-01

Hypertension is a common chronic disease that leads to significant cardiovascular morbidity and mortality. Blood pressure control is essential to prevent end-organ complications, such as stroke, myocardial infarction, heart failure, or kidney disease. Azilsartan is the eighth angiotensin II receptor blocker approved for the management of hypertension, alone or in combination with other agents. At the approved dosage, it reduces systolic blood pressure by 12 to 15 mm Hg and diastolic blood pressure by 7 to 8 mm Hg. A higher dose of azilsartan (80 mg) was superior to valsartan 320 mg or olmesartan 40 mg in lowering systolic blood pressure in short-term studies. Additional blood pressure reduction is expected when azilsartan is used adjunctively with a diuretic. However, the effects of azilsartan on cardiovascular morbidity or mortality are still lacking. Azilsartan is well tolerated; the most common side effects are headache and diarrhea. No cases of hyperkalemia have been reported in 6-week clinical trials. Worsening of renal function and hypotension should be monitored, particularly in those with baseline risk factors. It is unknown whether azilsartan would join angiotensin-converting enzyme inhibitors and other angiotensin receptor blockers as the preferred hypertensive agents for end-organ protection. At this time, azilsartan should be considered as an alternative agent for mild-to-moderate hypertension, or as an adjunctive therapy when preferred agents fail to maintain optimal blood pressure control. It is also an option for those patients who have contraindications or cannot tolerate other antihypertensive agents, including dry cough induced by angiotensin-converting enzyme inhibitors.

A single serving of blueberry (V. corymbosum) modulates peripheral arterial dysfunction induced by acute cigarette smoking in young volunteers: a randomized-controlled trial.

PubMed

Del Bo', Cristian; Porrini, Marisa; Fracassetti, Daniela; Campolo, Jonica; Klimis-Zacas, Dorothy; Riso, Patrizia

2014-12-01

Cigarette smoking causes oxidative stress, hypertension and endothelial dysfunction. Polyphenol-rich foods may prevent these conditions. We investigated the effect of a single serving of fresh-frozen blueberry intake on peripheral arterial function and arterial stiffness in young smokers. Sixteen male smokers were recruited for a 3-armed randomized-controlled study with the following experimental conditions: smoking treatment (one cigarette); blueberry treatment (300 g of blueberry) + smoking; control treatment (300 mL of water with sugar) + smoking. Each treatment was separated by one week of wash-out period. The blood pressure, heart rate, peripheral arterial function (reactive hyperemia and Framingham reactive hyperemia), and arterial stiffness (digital augmentation index, digital augmentation index normalized for a heart rate of 75 bpm) were measured before and 20 min after smoking with Endo-PAT2000. Smoking impaired the blood pressure, heart rate and peripheral arterial function, but did not affect the arterial stiffness. Blueberry consumption counteracted the impairment of the reactive hyperemia index induced by smoking (-4.4 ± 0.8% blueberry treatment vs. -22.0 ± 1.1% smoking treatment, p < 0.01) and Framingham reactive hyperemia (+28.3 ± 19.2% blueberry treatment vs. -42.8 ± 20.0% smoking treatment, p < 0.0001), and the increase of systolic blood pressure (+8.4 ± 0.02% blueberry treatment vs. +13.1 ± 0.02% smoking treatment, mmHg, p < 0.05) after cigarette smoking. No effect was observed for arterial stiffness and other vital signs. In conclusion, data obtained suggest a protective role of blueberry on reactive hyperemia, Framingham reactive hyperemia, and systolic blood pressure in subjects exposed to smoke of one cigarette. Future studies are necessary to elucidate the mechanisms involved.

Impact of Autologous Stem Cell Transplantation on Blood Pressure and Renal Function in Multiple Myeloma Patients.

PubMed

Balsam, Leah; Saad, Chadi; Arsene, Camelia; Fogel, Joshua

2017-01-01

Autologous stem cell transplantation (ASCT) reverses kidney failure in one-third of multiple myeloma (MM) patients, which may lead to blood pressure (BP) improvement. We evaluate the long term impact of ASCT on BP and renal function in MM patients. We studied 192 MM patients that underwent ASCT. We compared BP readings and glomerular filtration rate (GFR) at 4 weeks before ASCT, on day of ASCT and post-ASCT at 30, 100 and 180 days. Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) on day of ASCT and at both 30 and 100 days post-ASCT was significantly lower as compared to pre-ASCT SBP and DBP. There was a significantly higher mean GFR at day of ASCT and 30 days post-ASCT and significantly lower mean GFR at 180 days post-ASCT as compared to pre-ASCT. White patients had similar patterns to the total group for SBP, DBP, and GFR except for SBP which was still significantly lower and GFR which was not significantly different at 180 days. African-American patients showed no significant reductions in the mean values of SBP and DBP and no significant increases for GFR in follow-up after day of ASCT. Furthermore, the mean value of GFR was significantly lower at 180 days post-ASCT. ASCT in MM patients had a positive impact on SBP and DBP and GFR but the impact was minimal for African-American patients. We recommend that clinicians consider closer follow-up of BP and kidney function and more intense therapy in African-Americans with MM. Copyright © 2017 National Medical Association. Published by Elsevier Inc. All rights reserved.

Functional Promoter Polymorphisms Govern Differential Expression of HMG-CoA Reductase Gene in Mouse Models of Essential Hypertension

PubMed Central

Sonawane, Parshuram J.; Sahu, Bhavani S.; Sasi, Binu K.; Geedi, Parimala; Lenka, Govinda; Mahapatra, Nitish R.

2011-01-01

3-Hydroxy-3-methylglutaryl-coenzyme A [HMG-CoA] reductase gene (Hmgcr) is a susceptibility gene for essential hypertension. Sequencing of the Hmgcr locus in genetically hypertensive BPH (blood pressure high), genetically hypotensive BPL (blood pressure low) and genetically normotensive BPN (blood pressure normal) mice yielded a number of single nucleotide polymorphisms (SNPs). BPH/BPL/BPN Hmgcr promoter-luciferase reporter constructs were generated and transfected into liver HepG2, ovarian CHO, kidney HEK-293 and neuronal N2A cells for functional characterization of the promoter SNPs. The BPH-Hmgcr promoter showed significantly less activity than the BPL-Hmgcr promoter under basal as well as nicotine/cholesterol-treated conditions. This finding was consistent with lower endogenous Hmgcr expression in liver and lower plasma cholesterol in BPH mice. Transfection experiments using 5′-promoter deletion constructs (strategically made to assess the functional significance of each promoter SNP) and computational analysis predicted lower binding affinities of transcription factors c-Fos, n-Myc and Max with the BPH-promoter as compared to the BPL-promoter. Corroboratively, the BPH promoter-luciferase reporter construct co-transfected with expression plasmids of these transcription factors displayed less pronounced augmentation of luciferase activity than the BPL construct, particularly at lower amounts of transcription factor plasmids. Electrophoretic mobility shift assays also showed diminished interactions of the BPH promoter with HepG2 nuclear proteins. Taken together, this study provides mechanistic basis for the differential Hmgcr expression in these mouse models of human essential hypertension and have implications for better understanding the role of this gene in regulation of blood pressure. PMID:21304971

Vasopressin V2 receptor antagonist tolvaptan is effective in heart failure patients with reduced left ventricular systolic function and low blood pressure.

PubMed

Suzuki, Satoshi; Yoshihisa, Akiomi; Yamaki, Takayoshi; Sugimoto, Koichi; Kunii, Hiroyuki; Nakazato, Kazuhiko; Abe, Yukihiko; Saito, Tomiyoshi; Ohwada, Takayuki; Suzuki, Hitoshi; Saitoh, Shu-ichi; Kubota, Isao; Takeishi, Yasuchika

2015-01-01

Diuresis is a major therapy for the reduction of congestive symptoms in acute decompensated heart failure (ADHF) patients. Carperitide has natriuretic and vasodilatory effects, and tolvaptan produces water excretion without electrolyte excretion. We previously reported the usefulness of tolvaptan compared to carperitide in ADHF patients with fluid volume retention. The purpose of this study was to examine whether the efficacy of tolvaptan was altered in ADHF patients with reduced left ventricular systolic function and in those with hypotension. A total of 109 hospitalized ADHF patients were randomly assigned to either a tolvaptan or a carperitide treatment group. Baseline clinical characteristics were not different between the two groups. We divided these patients based on the left ventricular ejection fraction (EF) by echocardiography, and blood pressure (BP) at the time of admission. Daily urine volume between the tolvaptan and carperitide groups in patients with preserved EF (≥ 50%) was not different, however, in those with reduced EF (< 50%), the urine volume was significantly higher in the tolvaptan group than in the carperitide group (day 2, 3, 4, P < 0.05 for all). Daily urine volume did not differ between these two groups in the high blood pressure group (BP ≥ 140 mmHg), but was significantly higher in the tolvaptan group than in the carperitide group (day 1, P = 0.021; day 3, P = 0.017) in the low blood pressure group (BP < 140 mmHg). The present study reveals that tolvaptan is more effective than carperitide, especially in ADHF patients with reduced left ventricular systolic function and without hypertension.

Dynamics of pulsatile flow in fractal models of vascular branching networks.

PubMed

Bui, Anh; Sutalo, Ilija D; Manasseh, Richard; Liffman, Kurt

2009-07-01

Efficient regulation of blood flow is critically important to the normal function of many organs, especially the brain. To investigate the circulation of blood in complex, multi-branching vascular networks, a computer model consisting of a virtual fractal model of the vasculature and a mathematical model describing the transport of blood has been developed. Although limited by some constraints, in particular, the use of simplistic, uniformly distributed model for cerebral vasculature and the omission of anastomosis, the proposed computer model was found to provide insights into blood circulation in the cerebral vascular branching network plus the physiological and pathological factors which may affect its functionality. The numerical study conducted on a model of the middle cerebral artery region signified the important effects of vessel compliance, blood viscosity variation as a function of the blood hematocrit, and flow velocity profile on the distributions of flow and pressure in the vascular network.

Discordant orthostatic reflex renin-angiotensin and sympathoneural responses in premenopausal exercising-hypoestrogenic women.

PubMed

O'Donnell, Emma; Goodman, Jack M; Mak, Susanna; Murai, Hisayoshi; Morris, Beverley L; Floras, John S; Harvey, Paula J

2015-05-01

Our prior observations in normotensive postmenopausal women stimulated the hypotheses that compared with eumenorrheic women, active hypoestrogenic premenopausal women with functional hypothalamic amenorrhea would demonstrate attenuated reflex renin-angiotensin-aldosterone system responses to an orthostatic challenge, whereas to defend blood pressure reflex increases in muscle, sympathetic nerve activity would be augmented. To test these hypotheses, we assessed, in recreationally active women, 12 with amenorrhea (ExFHA; aged 25 ± 1 years; body mass index 20.7 ± 0.7 kg/m(2); mean ± SEM) and 17 with eumenorrhea (ExOv; 24 ± 1 years; 20.9 ± 0.5 kg/m(2)), blood pressure, heart rate, plasma renin, angiotensin II, aldosterone, and muscle sympathetic nerve activity at supine rest and during graded lower body negative pressure (-10, -20, and -40 mm Hg). At baseline, heart rate and systolic blood pressure were lower (P<0.05) in ExFHA (47 ± 2 beats/min and 94 ± 2 mm Hg) compared with ExOv (56 ± 2 beats/min and 105 ± 2 mm Hg), but muscle sympathetic nerve activity and renin-angiotensin-aldosterone system constituents were similar (P>0.05). In response to graded lower body negative pressure, heart rate increased (P<0.05) and systolic blood pressure decreased (P<0.05) in both groups, but these remained consistently lower in ExFHA (P<0.05). Lower body negative pressure elicited increases (P<0.05) in renin, angiotensin II, and aldosterone in ExOv, but not in ExFHA (P>0.05). Muscle sympathetic nerve activity burst incidence increased reflexively in both groups, but more so in ExFHA (P<0.05). Otherwise, healthy hypoestrogenic ExFHA women demonstrate low blood pressure and disruption of the normal circulatory response to an orthostatic challenge: plasma renin, angiotensin II, and aldosterone fail to increase and blood pressure is defended by an augmented sympathetic vasoconstrictor response. © 2015 American Heart Association, Inc.

Methodological comparison of active- and passive-driven oscillations in blood pressure; implications for the assessment of cerebral pressure-flow relationships.

PubMed

Smirl, Jonathan D; Hoffman, Keegan; Tzeng, Yu-Chieh; Hansen, Alex; Ainslie, Philip N

2015-09-01

We examined the between-day reproducibility of active (squat-stand maneuvers)- and passive [oscillatory lower-body negative pressure (OLBNP) maneuvers]-driven oscillations in blood pressure. These relationships were examined in both younger (n = 10; 25 ± 3 yr) and older (n = 9; 66 ± 4 yr) adults. Each testing protocol incorporated rest (5 min), followed by driven maneuvers at 0.05 (5 min) and 0.10 (5 min) Hz to increase blood-pressure variability and improve assessment of the pressure-flow dynamics using linear transfer function analysis. Beat-to-beat blood pressure, middle cerebral artery velocity, and end-tidal partial pressure of CO2 were monitored. The pressure-flow relationship was quantified in the very low (0.02-0.07 Hz) and low (0.07-0.20 Hz) frequencies (LF; spontaneous data) and at 0.05 and 0.10 Hz (driven maneuvers point estimates). Although there were no between-age differences, very few spontaneous and OLBNP transfer function metrics met the criteria for acceptable reproducibility, as reflected in a between-day, within-subject coefficient of variation (CoV) of <20%. Combined CoV data consist of LF coherence (15.1 ± 12.2%), LF gain (15.1 ± 12.2%), and LF normalized gain (18.5 ± 10.9%); OLBNP data consist of 0.05 (12.1 ± 15.%) and 0.10 (4.7 ± 7.8%) Hz coherence. In contrast, the squat-stand maneuvers revealed that all metrics (coherence: 0.6 ± 0.5 and 0.3 ± 0.5%; gain: 17.4 ± 12.3 and 12.7 ± 11.0%; normalized gain: 16.7 ± 10.9 and 15.7 ± 11.0%; and phase: 11.6 ± 10.2 and 17.3 ± 10.8%) at 0.05 and 0.10 Hz, respectively, were considered biologically acceptable for reproducibility. These findings have important implications for the reliable assessment and interpretation of cerebral pressure-flow dynamics in humans. Copyright © 2015 the American Physiological Society.

Methodological comparison of active- and passive-driven oscillations in blood pressure; implications for the assessment of cerebral pressure-flow relationships

PubMed Central

Hoffman, Keegan; Tzeng, Yu-Chieh; Hansen, Alex; Ainslie, Philip N.

2015-01-01

We examined the between-day reproducibility of active (squat-stand maneuvers)- and passive [oscillatory lower-body negative pressure (OLBNP) maneuvers]-driven oscillations in blood pressure. These relationships were examined in both younger (n = 10; 25 ± 3 yr) and older (n = 9; 66 ± 4 yr) adults. Each testing protocol incorporated rest (5 min), followed by driven maneuvers at 0.05 (5 min) and 0.10 (5 min) Hz to increase blood-pressure variability and improve assessment of the pressure-flow dynamics using linear transfer function analysis. Beat-to-beat blood pressure, middle cerebral artery velocity, and end-tidal partial pressure of CO2 were monitored. The pressure-flow relationship was quantified in the very low (0.02-0.07 Hz) and low (0.07–0.20 Hz) frequencies (LF; spontaneous data) and at 0.05 and 0.10 Hz (driven maneuvers point estimates). Although there were no between-age differences, very few spontaneous and OLBNP transfer function metrics met the criteria for acceptable reproducibility, as reflected in a between-day, within-subject coefficient of variation (CoV) of <20%. Combined CoV data consist of LF coherence (15.1 ± 12.2%), LF gain (15.1 ± 12.2%), and LF normalized gain (18.5 ± 10.9%); OLBNP data consist of 0.05 (12.1 ± 15.%) and 0.10 (4.7 ± 7.8%) Hz coherence. In contrast, the squat-stand maneuvers revealed that all metrics (coherence: 0.6 ± 0.5 and 0.3 ± 0.5%; gain: 17.4 ± 12.3 and 12.7 ± 11.0%; normalized gain: 16.7 ± 10.9 and 15.7 ± 11.0%; and phase: 11.6 ± 10.2 and 17.3 ± 10.8%) at 0.05 and 0.10 Hz, respectively, were considered biologically acceptable for reproducibility. These findings have important implications for the reliable assessment and interpretation of cerebral pressure-flow dynamics in humans. PMID:26183476

Independent associations between arterial bicarbonate, apnea severity and hypertension in obstructive sleep apnea.

PubMed

Eskandari, Davoud; Zou, Ding; Grote, Ludger; Schneider, Hartmut; Penzel, Thomas; Hedner, Jan

2017-06-28

Obstructive sleep apnea is characterized by intermittent hypoxia and hypercapnia. CO 2 production, transport and elimination are influenced by the carbonic anhydrase enzyme. We hypothesized that elevated standard bicarbonate, a proxy for increased carbonic anhydrase activity, is associated with apnea severity and higher blood pressure in patients with obstructive sleep apnea. A retrospective analysis of a sleep apnea cohort (n = 830) studied by ambulatory polygraphy. Office systolic/diastolic blood pressure, lung function, and arterial blood gases were assessed during daytime. Arterial standard bicarbonate was increased with apnea severity (mild/moderate/severe 24.1 ± 1.8, 24.4 ± 1.7 and 24.9 ± 2.9 mmol/l, respectively, Kruskal-Wallis test p < 0.001). Standard bicarbonate was independently associated with apnea hypopnea index after adjustment for sex, age, body mass index, smoking, alcohol, hypertension, pO 2 and pCO 2 (standard bicarbonate quartile 1 vs. quartile 4, β = 10.6, p < 0.001). Log-transformed standard bicarbonate was associated with a diagnosis of hypertension or diastolic blood pressure but not systolic blood pressure adjusting for cofounders (p = 0.007, 0.048 and 0.45, respectively). There was an independent association between sleep apnea severity and arterial standard bicarbonate. The link between high standard bicarbonate and daytime hypertension suggests that carbonic anhydrase activity may constitute a novel mechanism for blood pressure regulation in sleep apnea.

[The determination of arterial pressure by the physician or the nurse: its relation to ambulatory pressure and left ventricular mass. The MAPA-Madrid Group. Monitorización Ambulatoria de la Presión Arterial (Ambulatory Monitoring of Arterial Pressure)].

PubMed

Martínez, M A; Aguirre, A; Sánchez, M; Nevado, A; Laguna, I; Torre, A; Manuel, E; Villar, C; García-Puig, J

1999-12-11

In the present study we evaluated the influence of the observer's status--physician or nurse--on blood pressure levels and the relationship among clinic blood pressure measurement with ambulatory blood pressure and left ventricle mass. Cross sectional study performed in seven primary care centers. Participating physicians and nurses were trained for blood pressure measurement prior to the study and subsequently retrained at 3 month intervals during the study. Patients included in the study were 122 subjects with mild to moderate hypertension who underwent the following study protocol: a) measurement of clinic blood pressure by physician and nurse, in an independent fashion, on 3 visits; b) clinic-epidemiologic questionnaire; c) conventional hematological and biochemical study; d) electrocardiogram; e) 24-hour ambulatory blood pressure monitoring, f) M-mode and Doppler echocardiography (only in 58 subjects). Nurse-measured blood pressure levels were higher than those determined by physicians (mean differences: 3.9 [6.7] mmHg in systolic blood pressure and 2.6 [5.4] mmHg in diastolic blood pressure). The blood pressure level differences between the two observers were higher in female patients and subjects with low educational level, independently of the observer's gender. Nurse-measured blood pressure was more closely related to ambulatory blood pressure and left ventricle mass than physician-measured blood pressure. Nurse-measured blood pressure levels are lower than those determined by physicians and more closely related to ambulatory blood pressure and left ventricle mass than physician-measured blood pressure. These data support that nurses, instead of doctors, should routinely measure blood pressure in primary care centers.

The influence of blood pressure management on neurological outcome in endovascular therapy for acute ischaemic stroke.

PubMed

Rasmussen, M; Espelund, U S; Juul, N; Yoo, A J; Sørensen, L H; Sørensen, K E; Johnsen, S P; Andersen, G; Simonsen, C Z

2018-06-01

Observational studies have suggested that low blood pressure and blood pressure variability may partially explain adverse neurological outcome after endovascular therapy with general anaesthesia (GA) for acute ischaemic stroke. The aim of this study was to further examine whether blood pressure related parameters during endovascular therapy are associated with neurological outcome. The GOLIATH trial randomised 128 patients to either GA or conscious sedation for endovascular therapy in acute ischaemic stroke. The primary outcome was 90 day modified Rankin Score. The haemodynamic protocol aimed at keeping the systolic blood pressure >140 mm Hg and mean blood pressure >70 mm Hg during the procedure. Blood pressure related parameters of interest included 20% reduction in mean blood pressure; mean blood pressure <70 mm Hg, <80 mm Hg, and <90 mm Hg, respectively; time with systolic blood pressure <140 mm Hg; procedural minimum and maximum mean and systolic blood pressure; mean blood pressure at the time of groin puncture; postreperfusion mean blood pressure; blood pressure variability; and use of vasopressors. Sensitivity analyses were performed in the subgroup of reperfused patients. Procedural average mean and systolic blood pressures were higher in the conscious sedation group (P<0.001). The number of patients with mean blood pressure <70-90 mm Hg and systolic blood pressure <140 mm Hg, blood pressure variability, and use of vasopressors were all higher in the GA group (P<0.001). There was no statistically significant association between any of the examined blood pressure related parameters and the modified Rankin Score in the overall patient population, and in the subgroup of patients with full reperfusion. We found no statistically significant association between blood pressure related parameters during endovascular therapy and neurological outcome. NCT 02317237. Copyright © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

The effects of poststroke captopril and losartan treatment on cerebral blood flow autoregulation in SHRsp with hemorrhagic stroke.

PubMed

Smeda, John S; Daneshtalab, Noriko

2011-02-01

The ability of captopril and losartan treatment to restore cerebral blood flow (CBF) autoregulation after intracerebral hemorrhagic stroke (HS) was assessed in Kyoto-Wistar stroke-prone hypertensive rats (SHRsp). Laser Doppler techniques assessed CBF autoregulation in the middle cerebral artery (MCA) perfusion domain and a pressure myograph was used to measure pressure-dependent constriction (PDC) in isolated MCAs before and after stroke and after 13, 33, and 63 days of poststroke captopril or losartan treatment. The treatments did not lower blood pressure (BP) and equally suppressed plasma aldosterone after HS. The HS development was associated with the loss of CBF autoregulation, high CBF, increased CBF conductance to elevations in BP, and the loss of PDC in the MCAs. Both treatments restored these functions to prestroke levels within 13 days. The PDC and CBF autoregulation subsequently deteriorated after 63 days of captopril treatment while being maintained at prestroke levels over all durations of losartan treatment. The SHRsp subjected to 35 days of poststroke losartan treatment exhibited less blood-brain barrier (BBB) disruption and brain herniation than captopril-treated SHRsp. The superior ability of losartan to restore CBF autoregulation and myogenic function may have contributed to the more effective attenuation of cerebral damage after HS.

Subclinical atherosclerosis in obese adolescents with normal left ventricular function.

PubMed

Abdel-Wahab, Amina M; Atwa, Hoda A; El-Eraky, Azza Z; El-Aziz, Mohamed A

2011-09-01

To assess the impact of obesity on carotid intima media thickness and left ventricular (LV) mass in obese adolescents. The study included 52 obese adolescents (mean age 14.16+/-2.64 years) and 52 healthy adolescents who served as a control group (mean age 12+/-2.3 years), who were attended the outpatient clinic at Suez Canal University Hospital, Ismailia, Egypt. The study population was submitted for medical history, clinical examination, laboratory investigations (fasting blood sugar and lipid profile), and echocardiographic examination of LV mass and dimensions. Assessment of carotid intima-media thickness was carried out by using carotid duplex. All children had normal LV function. Obese adolescents had a significant increase in total cholesterol, triglyceride, LDL-C, and low HDL-C compared to the control group. Also, there was a significant increase in blood pressure, carotid intima media thickness, LV mass, and LV mass index. There was a significant correlation between BMI and dyslipidemia, blood pressure, carotid intima/media thickness, LV mass, and posterior wall thickness. Carotid intima-media thickness had a significant correlation with increased LDL-C and low HDL-C, blood pressure, LV mass, and posterior wall thickness. Obesity in childhood and adolescents is associated with subclinical atherosclerosis. Although obese children had no LV dysfunction, yet there are LV structure changes.

bpshape wk4: a computer program that implements a physiological model for analyzing the shape of blood pressure waveforms

NASA Technical Reports Server (NTRS)

Ocasio, W. C.; Rigney, D. R.; Clark, K. P.; Mark, R. G.; Goldberger, A. L. (Principal Investigator)

1993-01-01

We describe the theory and computer implementation of a newly-derived mathematical model for analyzing the shape of blood pressure waveforms. Input to the program consists of an ECG signal, plus a single continuous channel of peripheral blood pressure, which is often obtained invasively from an indwelling catheter during intensive-care monitoring or non-invasively from a tonometer. Output from the program includes a set of parameter estimates, made for every heart beat. Parameters of the model can be interpreted in terms of the capacitance of large arteries, the capacitance of peripheral arteries, the inertance of blood flow, the peripheral resistance, and arterial pressure due to basal vascular tone. Aortic flow due to contraction of the left ventricle is represented by a forcing function in the form of a descending ramp, the area under which represents the stroke volume. Differential equations describing the model are solved by the method of Laplace transforms, permitting rapid parameter estimation by the Levenberg-Marquardt algorithm. Parameter estimates and their confidence intervals are given in six examples, which are chosen to represent a variety of pressure waveforms that are observed during intensive-care monitoring. The examples demonstrate that some of the parameters may fluctuate markedly from beat to beat. Our program will find application in projects that are intended to correlate the details of the blood pressure waveform with other physiological variables, pathological conditions, and the effects of interventions.

Morphological and functional renovascular changes as cause of resistant arterial hypertension - case report and literature review.

PubMed

Costache, Irina Iuliana; Costea, Claudia Florida; Fotea, Vasile; Rusu, Victor Laurian; Aursulesei, Viviana; Al Namat, Razan; Costache, Dan Alexandru; Dumitrescu, Nicoleta; Buzdugă, Cătălin Mihai; Dumitrescu, Gabriela Florenţa; Sava, Anca; Bogdănici, Camelia Margareta

2018-01-01

Resistant hypertension is defined by the inability to maintain within normal limits the blood pressure values of an individual, while he is under treatment with maximal tolerated doses of three antihypertensive agents. One of the most common types of resistant hypertension is renovascular hypertension (RVH), which is caused by the narrowing of the renal arteries, in the context of existing atherosclerotic plaques at that level. We are presenting the case of a hypertensive 56-year-old man admitted in the Clinic of Cardiology for a sudden rise of his blood pressure values, despite undergoing the scheduled treatment. The abdominal bruit discovered at the clinical examination and the hypokalemia, together with the mild impairment of the renal function raised the suspicion of an existing stenosis of the main renal blood vessels. Simple grey scale kidney ultrasound, Doppler ultrasound of the renal arteries, abdominal computed tomography and magnetic resonance angiography of the renal arteries, along with invasive renal angiography demonstrated a smaller right kidney, adrenal incidentalomas, reduced vascular diameter of renal arteries due to atheromatous lesions, thrombosis of the infrarenal segment of the abdominal aorta, and reduced vascular hemodynamics in the same territories. After the renal arteries revascularization and with minimal antihypertensive treatment, the patient had a favorable outcome, with normalization of blood pressure and renal function. Atherosclerotic disease causing renal artery stenosis is essential to be taken into consideration in the etiopathogenesis of resistant hypertension especially because RVH is a potentially curable disease.

VALSARTAN REGULATES MYOCARDIAL AUTOPHAGY AND MITOCHONDRIAL TURNOVER IN EXPERIMENTAL HYPERTENSION

PubMed Central

Zhang, Xin; Li, Zi-Lun; Crane, John A.; Jordan, Kyra L.; Pawar, Aditya S.; Textor, Stephen C.; Lerman, Amir; Lerman, Lilach O.

2014-01-01

Renovascular hypertension alters cardiac structure and function. Autophagy is activated during left ventricular hypertrophy and linked to adverse cardiac function. The Angiotensin II receptor blocker Valsartan lowers blood pressure and is cardioprotective, but whether it modulates autophagy in the myocardium is unclear. We hypothesized that Valsartan would alleviate autophagy and improve left ventricular myocardial mitochondrial turnover in swine renovascular hypertension. Domestic pigs were randomized to control, unilateral renovascular hypertension, and renovascular hypertension treated with Valsartan (320 mg/day) or conventional triple therapy (Reserpine+hydralazine+hydrochlorothiazide) for 4 weeks post 6-weeks of renovascular hypertension (n=7 each group). Left ventricular remodeling, function and myocardial oxygenation and microcirculation were assessed by multi-detector computer tomography, blood-oxygen-level-dependent magnetic resonance imaging and microcomputer tomography. Myocardial autophagy, markers for mitochondrial degradation and biogenesis, and mitochondrial respiratory-chain proteins were examined ex vivo. Renovascular hypertension induced left ventricular hypertrophy and myocardial hypoxia, enhanced cellular autophagy and mitochondrial degradation, and suppressed mitochondrial biogenesis. Valsartan and triple therapy similarly decreased blood pressure, but Valsartan solely alleviated left ventricular hypertrophy, ameliorated myocardial autophagy and mitophagy, and increased mitochondrial biogenesis. In contrast, triple therapy only slightly attenuated autophagy and preserved mitochondrial proteins, but elicited no improvement in mitophagy. These data suggest a novel potential role of Valsartan in modulating myocardial autophagy and mitochondrial turnover in renovascular hypertension-induced hypertensive heart disease, which may possibly bolster cardiac repair via a blood pressure-independent manner. PMID:24752430

Cerebral blood velocity regulation during progressive blood loss compared with lower body negative pressure in humans.

PubMed

Rickards, Caroline A; Johnson, Blair D; Harvey, Ronée E; Convertino, Victor A; Joyner, Michael J; Barnes, Jill N

2015-09-15

Lower body negative pressure (LBNP) is often used to simulate blood loss in humans. It is unknown if cerebral blood flow responses to actual blood loss are analogous to simulated blood loss during LBNP. Nine healthy men were studied at baseline, during three levels of LBNP (5 min at -15, -30, and -45 mmHg), and during three levels of blood loss (333, 667, and 1,000 ml). LBNP and blood loss conditions were randomized. Intra-arterial mean arterial pressure (MAP) during LBNP was similar to that during blood loss (P ≥ 0.42). Central venous pressure (2.8 ± 0.7 vs. 4.0 ± 0.8, 1.2 ± 0.6 vs. 3.5 ± 0.8, and 0.2 ± 0.9 vs. 2.1 ± 0.9 mmHg for levels 1, 2, and 3, respectively, P ≤ 0.003) and stroke volume (71 ± 4 vs. 80 ± 3, 60 ± 3 vs. 74 ± 3, and 51 ± 2 vs. 68 ± 4 ml for levels 1, 2, and 3, respectively, P ≤ 0.002) were lower during LBNP than blood loss. Despite differences in central venous pressure, middle cerebral artery velocity (MCAv) and cerebrovascular conductance were similar between LBNP and blood loss at each level (MCAv at level 3: 62 ± 6 vs. 66 ± 5 cm/s, P = 0.37; cerebrovascular conductance at level 3: 0.72 ± 0.05 vs. 0.73 ± 0.05 cm·s(-1)·mmHg(-1), P = 0.53). While the slope of the MAP-MCAv relationship was slightly different between LBNP and blood loss (0.41 ± 0.03 and 0.66 ± 0.04 cm·s(-1)·mmHg(-1), respectively, P = 0.05), time domain gain between MAP and MCAv at maximal LBNP/blood loss (P = 0.23) and low-frequency MAP-mean MCAv transfer function coherence, gain, and phase were similar (P ≥ 0.10). Our results suggest that cerebral hemodynamic responses to LBNP to -45 mmHg and blood loss up to 1,000 ml follow a similar trajectory, and the arterial pressure-cerebral blood velocity relationship is not altered from baseline under these conditions.

Effectiveness of acarbose in treating elderly patients with diabetes with postprandial hypotension.

PubMed

Zhang, Jie; Guo, Lixin

2017-04-01

: Postprandial hypotension (PPH) is a common condition that occurs primarily in elderly patients with type 2 diabetes mellitus (T2DM). This study aimed to assess the effectiveness of acarbose for PPH; it also investigated possible mechanisms behind PPH development. This single-blind, randomized controlled trial included 91 elderly patients with T2DM, aged between 60 and 80 years, who were inpatients at Beijing Hospital between March 2012 and November 2014. The patients were included into one of three groups: Group A, patients with T2DM without PPH; Group B, patients with T2DM with PPH receiving placebo; and Group C, patients with T2DM with PPH receiving acarbose. After an overnight fast, patients received a single dose of acarbose (100 mg) or placebo and then consumed a standardized 450 kcal meal. Blood pressure, glucose levels, heart rate (HR), and catecholamine levels were evaluated. Acarbose ameliorated PPH as determined by significant improvements in the duration and maximal fall in blood pressure (both p<0.001); however, no differences in HR and blood glucose levels were observed. In patients with PPH, blood pressure was correlated with blood glucose and HR variability values (p<0.05). Correlations between epinephrine and glucagon-like peptide-1 with blood pressure in groups A and C were largely lost in group B. Acarbose reduced postprandial blood pressure fluctuations in elderly patients with diabetes. PPH may be related to impaired autonomic nervous system function, reduced catecholamine secretion, and postprandial fluctuations in blood glucose levels. Chinese Clinical Trial Registry ChiCTR-IPR-15006177. Copyright © 2017 American Federation for Medical Research.

βENaC is a molecular component of a VSMC mechanotransducer that contributes to renal blood flow regulation, protection from renal injury, and hypertension.

PubMed

Drummond, Heather A

2012-01-01

Pressure-induced constriction (also known as the "myogenic response") is an important mechano-dependent response in certain blood vessels. The response is mediated by vascular smooth muscle cells (VSMCs) and characterized by a pressure-induced vasoconstriction in small arteries and arterioles in the cerebral, mesenteric, cardiac, and renal beds. The myogenic response has two important roles; it is a mechanism of blood flow autoregulation and provides protection against systemic blood pressure-induced damage to delicate microvessels. However, the molecular mechanism(s) underlying initiation of myogenic response is unclear. Degenerin proteins have a strong evolutionary link to mechanotransduction in the nematode. Our laboratory has addressed the hypothesis that these proteins may also act as mechanosensors in certain mammalian tissues such as VSMCs and arterial baroreceptor neurons. This article discusses the importance of a specific degenerin protein, β Epithelial Na(+) Channel (βENaC) in pressure-induced vasoconstriction in renal vessels and arterial baroreflex function as determined in a mouse model of reduced βENaC (βENaC m/m). We propose that loss of baroreflex sensitivity (due to loss of baroreceptor βENaC) increases blood pressure variability, increasing the likelihood and magnitude of upward swings in systemic pressure. Furthermore, loss of the myogenic constrictor response (due to loss of VSMC βENaC) will permit those pressure swings to be transmitted to the microvasculature in βENaC m/m mice, thus increasing the susceptibility to renal injury and hypertension.

Effect of the selective phosphodiesterase type 5 inhibitor sildenafil on erectile dysfunction in the anesthetized dog.

PubMed

Carter, A J; Ballard, S A; Naylor, A M

1998-07-01

The effects of sildenafil, a highly selective inhibitor of cyclic guanosine monophosphate-specific phosphodiesterase type 5, on erectile function in the anesthetized dog were evaluated. In pentobarbital-anesthetized dogs, increases in intracavernosal pressure in the corpus cavernosum and penile blood flow were induced by pelvic nerve stimulation over a frequency range of 1 to 16 hertz. The effects of increasing doses of sildenafil on electrically stimulated intracavernosal pressure, penile blood flow, blood pressure, and heart-rate were evaluated. In parallel experiments, the effects of the nitric oxide synthase inhibitor N omega-Nitro-L-Arginine (L-NOArg) on these same parameters also were assessed. The effects of nerve stimulation on intracavernosal pressure and blood flow to the penis were blocked by L-NOArg, 0.1-3 mg./kg., in a dose-related manner, confirming the important role of nitric oxide in producing erections. Sildenafil, 1-100 microg./kg administered intravenously, had no direct effect on intracavernosal pressure but potentiated the increase in intracavernosal pressure induced by nerve stimulation. This potentiation occurred at sildenafil plasma concentrations consistent with its relaxation effect on isolated human cavernosal tissue and its inhibition of phosphodiesterase type 5 in vitro. Sildenafil had no significant effect on blood pressure or heart rate. By inhibiting cyclic guanosine monophosphate-specific phosphodiesterase type 5, sildenafil augments the neuronal mechanism responsible for penile erection. This mechanism explains the significant improvements reported in the rigidity and duration of erections seen in patients with erectile dysfunction who have been treated with oral sildenafil.

Cardioankle vascular index evaluations revealed that cotreatment of ARB Antihypertension medication with traditional Chinese medicine improved arterial functionality.

PubMed

Xu, Yan; Yan, Hua; Yao, Min J; Ma, Jie; Jia, Jun M; Ruan, Fen X; Yao, Zeng C; Huang, Hua M; Zheng, Jing; Chen, Ting; Lv, Hua; Endler, Alexander M

2013-05-01

Qian Yang He Ji (QYHJ) is a traditional Chinese medicine composed of Digitalis purpurea, Uncaria gambir, Fructus tribuli terrestris, and Ligustrum lucidum. Here, we explored whether combining an antihypertensive angiotensin II receptor blocker (ARB) therapy with QYHJ can improve the arterial functionality of hypertensive patients. One hundred and eight hypertensive patients were randomized into 2 groups; 1 group (n = 53) was treated with ARB and the other group (n = 55) was treated with ARB combined with QYHJ. Each of the 2 groups included 3 subgroups (pure hypertension, hypertension with diabetes, and hypertension with coronary heart disease) and was further divided into patients with and without complications. The cardioankle vascular index and intima-media thickness and pulse pressure were the outcome evaluation parameter. Combined QYHJ and ARB treatment reduced the values of cardioankle vascular index, systolic blood pressure, diastolic blood pressure, and pulse pressure to significantly lower levels than ARB treatment alone did in hypertension patients after 6 months of treatment. ARB improves hypertension, but a combined QYHJ treatment can additionally ameliorate the arterial functionality not only in solely hypertensive patients but also in hypertensive patients with diabetes and coronary heart disease complications. QYHJ coapplication might be a choice to further improve the arterial functionality during an ARB hypertension treatment.

Physiological reactivity during autobiographical narratives in older adults: the roles of depression and anxiety.

PubMed

Robertson, Sarah M C; Swickert, Rhonda J; Connelly, Kathryn; Galizio, Ann

2015-01-01

Physiological reactivity (PR) describes the change in physiological functioning (e.g., heart rate, blood pressure, pulse pressure) that occurs after the induction of a stressful task. This study aims to understand the influence of mental health symptoms on patterns of PR during autobiographical narratives in an older adult sample. Eighty older adults completed self-report measures regarding their symptoms of depression and anxiety. Next, their blood pressure was recorded while they completed two verbal autobiographical narratives. During the positive narrative, anxiety was positively associated with increased PR while depression was negatively associated with PR. During the negative narrative, a significant interaction occurred whereby anxiety was significantly positively associated with PR for those participants low in depression. The above results are explained in the context of the Tripartite Model of Depression and Anxiety, which predicts different patterns of PR as a function of mental health symptoms. Limitations and future directions are also discussed.

The pulsating brain: A review of experimental and clinical studies of intracranial pulsatility

PubMed Central

2011-01-01

The maintenance of adequate blood flow to the brain is critical for normal brain function; cerebral blood flow, its regulation and the effect of alteration in this flow with disease have been studied extensively and are very well understood. This flow is not steady, however; the systolic increase in blood pressure over the cardiac cycle causes regular variations in blood flow into and throughout the brain that are synchronous with the heart beat. Because the brain is contained within the fixed skull, these pulsations in flow and pressure are in turn transferred into brain tissue and all of the fluids contained therein including cerebrospinal fluid. While intracranial pulsatility has not been a primary focus of the clinical community, considerable data have accrued over the last sixty years and new applications are emerging to this day. Investigators have found it a useful marker in certain diseases, particularly in hydrocephalus and traumatic brain injury where large changes in intracranial pressure and in the biomechanical properties of the brain can lead to significant changes in pressure and flow pulsatility. In this work, we review the history of intracranial pulsatility beginning with its discovery and early characterization, consider the specific technologies such as transcranial Doppler and phase contrast MRI used to assess various aspects of brain pulsations, and examine the experimental and clinical studies which have used pulsatility to better understand brain function in health and with disease. PMID:21349153

Pharmacokinetic-pharmacodynamic modeling of the antihypertensive interaction between azilsartan medoxomil and chlorthalidone in spontaneously hypertensive rats.

PubMed

Kumar Puttrevu, Santosh; Ramakrishna, Rachumallu; Bhateria, Manisha; Jain, Moon; Hanif, Kashif; Bhatta, Rabi Sankar

2017-05-01

A pharmacokinetic-pharmacodynamic (PK-PD) model was developed to describe the time course of blood pressure following oral administration of azilsartan medoxomil (AZM) and/or chlorthalidone (CLT) in spontaneously hypertensive (SH) rats. The drug concentration and pharmacological effects, including systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and tail-cuff manometry, respectively. Sequential PK-PD analysis was performed, wherein the plasma concentration-time data was modeled by one compartmental analysis. Subsequently PD parameters were calculated to describe the time-concentration-response relationship using indirect response (IDR) PK-PD model. The combination of AZ and CLT had greater BP lowering effect compared to AZ or CLT alone, despite of no pharmacokinetic interaction between two drugs. These findings suggest synergistic antihypertensive pharmacodynamic interaction between AZ and CLT noncompetitively, which was simulated by inhibitory function of AZ and stimulatory function of CLT after concomitant administration of the two drugs. The present model was able to capture the turnover of blood pressure adequately at different time points at two different dose levels. The current PK-PD model was successfully utilized in the simulation of PD effect at a dose combination of 0.5 and 2.5 mg/kg for AZ and CLT, respectively. The developed preclinical PK-PD model may provide guidance in the optimization of dose ratio of individual drugs in the combined pharmacotherapy of AZ and CLT at clinical situations.

Hierarchical poroelasticity: movement of interstitial fluid between porosity levels in bones.

PubMed

Cowin, Stephen C; Gailani, Gaffar; Benalla, Mohammed

2009-09-13

The governing equations for the theory of poroelastic materials with hierarchical pore space architecture and compressible constituents undergoing small deformations are developed. These equations are applied to the problem of determining the exchange of pore fluid between the vascular porosity (PV) and the lacunar-canalicular porosity (PLC) in bone tissue due to cyclic mechanical loading and blood pressure oscillations. The result is basic to the understanding of interstitial flow in bone tissue that, in turn, is basic to understanding of nutrient transport from the vasculature to the bone cells buried in the bone tissue and to the process of mechanotransduction by these cells. A formula for the volume of fluid that moves between the PLC and PV in a cyclic loading is obtained as a function of the cyclic mechanical loading and blood pressure oscillations. Formulas for the oscillating fluid pore pressure in both the PLC and the PV are obtained as functions of the two driving forces, the cyclic mechanical straining and the blood pressure, both with specified amplitude and frequency. The results of this study also suggest a PV permeability greater than 10(-9) m(2) and perhaps a little lower than 10(-8) m(2). Previous estimates of this permeability have been as small as 10(-14) m(2).

Hypertensive crisis caused by electrocauterization of the adrenal gland during hepatectomy.

PubMed

Doo, A Ram; Son, Ji-Seon; Han, Young-Jin; Yu, Hee Chul; Ko, Seonghoon

2015-02-14

Hypertensive crisis (i.e., systolic blood pressure over 300 mmHg) is very rare during operation except pheochromocytoma, but it can be a fatal and embarrassing to surgeons and anesthesiologists. The right adrenal gland can be electrocauterized during a right hemi-hepatectomy. We report a case of hypertensive crisis during right hemi-hepatectomy in which the right adrenal gland was stimulated by monopolar electrocautery in a patient with normal neuroendocrine function. A 73-year-old man with hepatocellular carcinoma was scheduled to undergo right hemi-hepatectomy. Three hours into the surgery, the patient's blood pressure increased abruptly from 100/40 to over 350/130 mmHg (the maximum measurement pressure of the monitor; 350 mmHg). The surgeon had cauterized the right adrenal gland using monopolar electrocautery to separate the liver from the adrenal gland immediately prior to the event. Approximately 3 minutes after suspending the operation, blood pressure returned to baseline levels. After the event, the operation was successfully completed without any complication. Hormonal studies and iodine-123 meta-iodobenzylguanidine scintigraphy revealed no neuroendocrine tumor such as a pheochromocytoma. Operations such as hepatectomy that stimulate the adrenal gland may lead to an unexpected catecholamine surge and result in hypertensive crisis, even if neuroendocrine function of the adrenal gland is normal.

Post-partum trend in blood pressure levels, renal function and proteinuria in women with severe preeclampsia and eclampsia in Sub-Saharan Africa: a 6-months cohort study.

PubMed

Kaze, Francois Folefack; Njukeng, Francis A; Kengne, Andre-Pascal; Ashuntantang, Gloria; Mbu, Robinson; Halle, Marie Patrice; Asonganyi, Tazoacha

2014-04-09

Preeclampsia and eclampsia, which are the most frequent hypertensive disorders in pregnancy, are associated with renal involvements. We aimed to assess the time trend in blood pressure levels, renal function and proteinuria after delivery, and investigate their determinants in Cameroonian women with severe preeclampsia and eclampsia. This was a prospective cohort study involving 54 women with severe preeclampsia and eclampsia, conducted between July 2010 and February 2012 at the central maternity unit of the Yaoundé Central Hospital. Clinical and laboratory parameters were recorded from day-1 to 6 months after delivery. Mixed-linear and logistic regression models were used to relate baseline and within follow-up levels of covariates, with changes in blood pressure levels, renal function and proteinuria, as well as persisting hypertension, renal failure and proteinuria. During follow-up, a significant improvement was observed in blood pressure, renal function and proteinuria (all p < 0.002). Thirteen (24.1%) patients with renal failure at delivery recovered completely within six weeks. Twenty-six (48.1%), 17 (31.5%) and 1 (1.8%) patients had persisting proteinuria at 6 weeks, 3 months and 6 months post-delivery, respectively. Corresponding figures for persisting hypertension were 23 (42.6%), 15 (27.8%) and 8 (14.8%). Advanced age, higher body mass index, low gestational age at delivery, low fetal birth weight, and proteinuria at delivery were the main risk factors for persisting hypertension at 3 months, meanwhile low fetal birth weight, severe preeclampsia and proteinuria at delivery were correlated with persisting proteinuria at 3 months. Advanced age and higher body mass index were the only determinants of the composite outcome of persisting hypertension or proteinuria at three and six months. Hypertension and proteinuria are very common beyond the postpartum period in Cameroonian women with severe preeclampsia and eclampsia. Long-term follow-up of these women will help preventing and controlling related complications.

Dual therapy of vildagliptin and telmisartan on diabetic nephropathy in experimentally induced type 2 diabetes mellitus rats.

PubMed

Sharma, Ashish Kumar; Kanawat, Devendra Singh; Mishra, Akanksha; Dhakad, Prashant Kumar; Sharma, Prashant; Srivastava, Varnika; Joshi, Sneha; Joshi, Megha; Raikwar, Sachin Kumar; Kurmi, Muneem Kumar; Srinivasan, Bharthu Parthsarthi

2014-12-01

The objective of this article is to investigate the combination of telmisartan with vildagliptin therapy versus monotherapy of vildagliptin and telmisartan on diabetic nephropathy in type 2 diabetes mellitus rats. In adult rats streptozotocin (65 mg/kg) and nicotinamide (110 mg/kg) were injected intraperitoneally to produce diabetic nephropathy. Rats of either sex allotted to the following groups: (i) triple therapy: metformin (120 mg/kg, o.d.) + pioglitazone (1.25 mg/kg, o.d.) + glimepiride (0.7 mg/kg, o.d.); (ii) dual therapy: vildagliptin (8.76 mg/kg, o.d.) + telmisartan (6.48 mg/kg, o.d.); (iii) vildagliptin (8.76 mg/kg, o.d.); and (iv) telmisartan (6.48 mg/kg, o.d.); therapy was carried out for 35 days orally. Weekly at days 7, 14, 21, 28 and 35, blood pressure, blood glucose level, body weight, blood serum creatinine level, protein albumin level in urine, and blood urea nitrogen (BUN) were estimated. Renal structural changes were observed. Blood pressure, blood glucose level, blood serum creatinine level, protein albumin level in urine, BUN and renal deterioration increased significantly in diabetic rats compared with normal control rats. The vildagliptin + telmisartan treatment group showed no weight gain and controlled blood pressure, renovascular structural and biochemical parameters in diabetic neuropathy rats. The addition of telmisartan to vildagliptin demonstrated the best control over blood pressure, glycemia and diabetic nephropathy markers, renal structural changes and improvement of renal function as opposed to monotherapy with either drug, possibly because of the dual inhibitory effect on the renin-angiotensin system. © The Author(s) 2013.

Differences in Physical Fitness and Cardiovascular Function Depend on BMI in Korean Men.

PubMed

So, Wi-Young; Choi, Dai-Hyuk

2010-01-01

We investigated the associations between cardiovascular function and both body mass index and physical fitness in Korean men. The subjects were 2,013 men, aged 20 to 83 years, who visited a health promotion center for a comprehensive medical and fitness test during 2006-2009. The WHO's Asia-Pacific Standard Report definition of BMI was used in this study. Fitness assessment of cardiorespiratory endurance, muscular strength, muscular endurance, flexibility, power, agility, and balance were evaluated by VO2max (ml/kg/min), grip strength (kg), sit-ups (reps/min), sit and reach (cm), vertical jump (cm), side steps (reps/30s), and standing on one leg with eyes closed (sec), respectively. For cardiovascular function, we evaluated systolic blood pressure (SBP), diastolic blood pressure (DBP), resting heart rate (RHR), double product (DP), and vital capacity. There were significant decreases in cardiorespiratory endurance (p < 0.001), power (p < 0.001), and balance (p < 0.001), and increases in muscular strength (p < 0.001). Further, cardiovascular function, including SBP (p < 0.001), DBP (p < 0.001), double product (p < 0.001), and vital capacity (p=0.006) appeared to be lower for the obesity group. We conclude that an obese person exhibits lower fitness level and weaker cardiovascular function than a normal person. Key pointsThe obese group had a lower fitness level, including cardiorespiratory endurance, power, and balance.Obese group demonstrated an increase in muscular strength.Obese group had higher blood pressure and weaker cardiovascular function, including DP and vital capacity, than the normal group.

Differences in Physical Fitness and Cardiovascular Function Depend on BMI in Korean Men

PubMed Central

So, Wi-Young; Choi, Dai-Hyuk

2010-01-01

We investigated the associations between cardiovascular function and both body mass index and physical fitness in Korean men. The subjects were 2,013 men, aged 20 to 83 years, who visited a health promotion center for a comprehensive medical and fitness test during 2006-2009. The WHO's Asia-Pacific Standard Report definition of BMI was used in this study. Fitness assessment of cardiorespiratory endurance, muscular strength, muscular endurance, flexibility, power, agility, and balance were evaluated by VO2max (ml/kg/min), grip strength (kg), sit-ups (reps/min), sit and reach (cm), vertical jump (cm), side steps (reps/30s), and standing on one leg with eyes closed (sec), respectively. For cardiovascular function, we evaluated systolic blood pressure (SBP), diastolic blood pressure (DBP), resting heart rate (RHR), double product (DP), and vital capacity. There were significant decreases in cardiorespiratory endurance (p < 0.001), power (p < 0.001), and balance (p < 0.001), and increases in muscular strength (p < 0.001). Further, cardiovascular function, including SBP (p < 0.001), DBP (p < 0.001), double product (p < 0.001), and vital capacity (p=0.006) appeared to be lower for the obesity group. We conclude that an obese person exhibits lower fitness level and weaker cardiovascular function than a normal person. Key points The obese group had a lower fitness level, including cardiorespiratory endurance, power, and balance. Obese group demonstrated an increase in muscular strength. Obese group had higher blood pressure and weaker cardiovascular function, including DP and vital capacity, than the normal group. PMID:24149691

A wireless blood pressure monitoring system for personal health management.

PubMed

Li, Wun-Jin; Luo, Yuan-Long; Chang, Yao-Shun; Lin, Yuan-Hsiang

2010-01-01

In this paper, we developed a wireless blood pressure monitoring system which provides a useful tool for users to measure and manage their daily blood pressure values. This system includes an ARM-based blood pressure monitor with a ZigBee wireless transmission module and a PC-based management unit with graphic user interface and database. The wireless blood pressure monitor can measure the blood pressure and heart rate and then store and forward the measuring information to the management unit through the ZigBee wireless transmission. On the management unit, user can easy to see their blood pressure variation in the past using a line chart. Accuracy of blood pressure measurement has been verified by a commercial blood pressure simulator and shown the bias of systolic blood pressure is ≤ 1 mmHg and the bias of diastolic blood pressure is ≤ 1.4 mmHg.

Effects of Parental Smoking on Exercise Systolic Blood Pressure in Adolescents

PubMed Central

Hacke, Claudia; Weisser, Burkhard

2015-01-01

Background In adults, exercise blood pressure seems to be more closely related to cardiovascular risk than resting blood pressure; however, few data are available on the effects of familial risk factors, including smoking habits, on exercise blood pressure in adolescents. Methods and Results Blood pressure at rest and during exercise, parental smoking, and other familial risk factors were investigated in 532 adolescents aged 12 to 17 years (14.6±1.5 years) in the Kiel EX.PRESS. (EXercise PRESSure) Study. Exercise blood pressure was determined at 1.5 W/kg body weight using a standardized submaximal cycle ergometer test. Mean resting blood pressure was 113.1±12.8/57.2±7.1 mm Hg, and exercise blood pressure was 149.9±19.8/54.2±8.6 mm Hg. Parental smoking increased exercise systolic blood pressure (+4.0 mm Hg, 3.1 to 4.9; P=0.03) but not resting blood pressure of the subjects (adjusted for age, sex, height, body mass index percentile, fitness). Parental overweight and familial hypertension were related to both higher resting and exercise systolic blood pressure values, whereas associations with an inactive lifestyle and a low educational level of the parents were found only with adolescents’ blood pressure during exercise. The cumulative effect of familial risk factors on exercise systolic blood pressure was more pronounced than on blood pressure at rest. Conclusions Parental smoking might be a novel risk factor for higher blood pressure, especially during exercise. In addition, systolic blood pressure during a submaximal exercise test was more closely associated with familial risk factors than was resting blood pressure, even in adolescents. PMID:25964207

Effects of parental smoking on exercise systolic blood pressure in adolescents.

PubMed

Hacke, Claudia; Weisser, Burkhard

2015-05-11

In adults, exercise blood pressure seems to be more closely related to cardiovascular risk than resting blood pressure; however, few data are available on the effects of familial risk factors, including smoking habits, on exercise blood pressure in adolescents. Blood pressure at rest and during exercise, parental smoking, and other familial risk factors were investigated in 532 adolescents aged 12 to 17 years (14.6±1.5 years) in the Kiel EX.PRESS. (EXercise PRESSure) Study. Exercise blood pressure was determined at 1.5 W/kg body weight using a standardized submaximal cycle ergometer test. Mean resting blood pressure was 113.1±12.8/57.2±7.1 mm Hg, and exercise blood pressure was 149.9±19.8/54.2±8.6 mm Hg. Parental smoking increased exercise systolic blood pressure (+4.0 mm Hg, 3.1 to 4.9; P=0.03) but not resting blood pressure of the subjects (adjusted for age, sex, height, body mass index percentile, fitness). Parental overweight and familial hypertension were related to both higher resting and exercise systolic blood pressure values, whereas associations with an inactive lifestyle and a low educational level of the parents were found only with adolescents' blood pressure during exercise. The cumulative effect of familial risk factors on exercise systolic blood pressure was more pronounced than on blood pressure at rest. Parental smoking might be a novel risk factor for higher blood pressure, especially during exercise. In addition, systolic blood pressure during a submaximal exercise test was more closely associated with familial risk factors than was resting blood pressure, even in adolescents. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Acute but not chronic metabolic acidosis potentiates the acetylcholine-induced reduction in blood pressure: an endothelium-dependent effect

PubMed Central

Celotto, A.C.; Ferreira, L.G.; Capellini, V.K.; Albuquerque, A.A.S.; Rodrigues, A.J.; Evora, P.R.B.

2015-01-01

Metabolic acidosis has profound effects on vascular tone. This study investigated the in vivo effects of acute metabolic acidosis (AMA) and chronic metabolic acidosis (CMA) on hemodynamic parameters and endothelial function. CMA was induced by ad libitum intake of 1% NH4Cl for 7 days, and AMA was induced by a 3-h infusion of 6 M NH4Cl (1 mL/kg, diluted 1:10). Phenylephrine (Phe) and acetylcholine (Ach) dose-response curves were performed by venous infusion with simultaneous venous and arterial blood pressure monitoring. Plasma nitrite/nitrate (NOx) was measured by chemiluminescence. The CMA group had a blood pH of 7.15±0.03, which was associated with reduced bicarbonate (13.8±0.98 mmol/L) and no change in the partial pressure of arterial carbon dioxide (PaCO2). The AMA group had a pH of 7.20±0.01, which was associated with decreases in bicarbonate (10.8±0.54 mmol/L) and PaCO2 (47.8±2.54 to 23.2±0.74 mmHg) and accompanied by hyperventilation. Phe or ACh infusion did not affect arterial or venous blood pressure in the CMA group. However, the ACh infusion decreased the arterial blood pressure (ΔBP: -28.0±2.35 mm Hg [AMA] to -4.5±2.89 mmHg [control]) in the AMA group. Plasma NOx was normal after CMA but increased after AMA (25.3±0.88 to 31.3±0.54 μM). These results indicate that AMA, but not CMA, potentiated the Ach-induced decrease in blood pressure and led to an increase in plasma NOx, reinforcing the effect of pH imbalance on vascular tone and blood pressure control. PMID:26648089

Roles of preoperative arterial blood gas tests in the surgical treatment of scoliosis with moderate or severe pulmonary dysfunction.

PubMed

Liu, Jia-Ming; Shen, Jian-Xiong; Zhang, Jian-Guo; Zhao, Hong; Li, Shu-Gang; Zhao, Yu; Qiu, Giu-Xing

2012-01-01

It has been stated that preoperative pulmonary function tests are essential to assess the surgical risk in patients with scoliosis. Arterial blood gas tests have also been used to evaluate pulmonary function before scoliotic surgery. However, few studies have been reported. The aim of this study was to investigate the roles of preoperative arterial blood gas tests in the surgical treatment of scoliosis with moderate or severe pulmonary dysfunction. This study involved scoliotic patients with moderate or severe pulmonary dysfunction (forced vital capacity < 60%) who underwent surgical treatment between January 2002 and April 2010. A total of 73 scoliotic patients (23 males and 50 females) with moderate or severe pulmonary dysfunction were included. The average age of the patients was 16.53 years (ranged 10 - 44). The demographic distribution, medical records, and radiographs of all patients were collected. All patients received arterial blood gas tests and pulmonary function tests before surgery. The arterial blood gas tests included five parameters: partial pressure of arterial oxygen, partial pressure of arterial carbon dioxide, alveolar-arterial oxygen tension gradient, pH, and standard bases excess. The pulmonary function tests included three parameters: forced expiratory volume in 1 second ratio, forced vital capacity ratio, and peak expiratory flow ratio. All five parameters of the arterial blood gas tests were compared between the two groups with or without postoperative pulmonary complications by variance analysis. Similarly, all three parameters of the pulmonary function tests were compared. The average coronal Cobb angle before surgery was 97.42° (range, 50° - 180°). A total of 15 (20.5%) patients had postoperative pulmonary complications, including hypoxemia in 5 cases (33.3%), increased requirement for postoperative ventilatory support in 4 (26.7%), pneumonia in 2 (13.3%), atelectasis in 2 (13.3%), pneumothorax in 1 (6.7%), and hydrothorax in 1 (6.7%). No significant differences in demographic characteristics or perioperative factors (P > 0.05) existed between the two groups with or without postoperative pulmonary complications. According to the variance analysis, there were no statistically significant differences in any parameter of the arterial blood gas tests between the two groups. No significant correlation between the results of the preoperative arterial blood gas tests and postoperative pulmonary complications existed in scoliotic patients with moderate or severe pulmonary dysfunction. However, the postoperative complications tended to increase with the decrease of partial pressure of arterial oxygen in the arterial blood gas tests.

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: a pooled analysis of 1018 population-based measurement studies with 88.6 million participants.

PubMed

2018-03-19

Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probit-transformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the high-income Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups.

The Gravity of LBNP Exercise: Lessons Learned from Identical Twins in Bed for 30 Days

NASA Technical Reports Server (NTRS)

Hargens, Alan R.; Groppo, Eli R.; Lee, Stuart M. C.; Watenpaugh, Donald; Schneider, Suzanne; O'Leary, Deborah; Smith, Scott M.; Steinbach, Gregory C.; Tanaka, Kunihiko; Kimura, Shinji;

Optic nerve head blood flow response to reduced ocular perfusion pressure by alteration of either the blood pressure or intraocular pressure.

PubMed

Wang, Lin; Cull, Grant A; Fortune, Brad

2015-04-01

To test the hypothesis that blood flow autoregulation in the optic nerve head has less reserve to maintain normal blood flow in the face of blood pressure-induced ocular perfusion pressure decrease than a similar magnitude intraocular pressure-induced ocular perfusion pressure decrease. Twelve normal non-human primates were anesthetized by continuous intravenous infusion of pentobarbital. Optic nerve blood flow was monitored by laser speckle flowgraphy. In the first group of animals (n = 6), the experimental eye intraocular pressure was maintained at 10 mmHg using a saline reservoir connected to the anterior chamber. The blood pressure was gradually reduced by a slow injection of pentobarbital. In the second group (n = 6), the intraocular pressure was slowly increased from 10 mmHg to 50 mmHg by raising the reservoir. In both experimental groups, optic nerve head blood flow was measured continuously. The blood pressure and intraocular pressure were simultaneously recorded in all experiments. The optic nerve head blood flow showed significant difference between the two groups (p = 0.021, repeat measures analysis of variance). It declined significantly more in the blood pressure group compared to the intraocular pressure group when the ocular perfusion pressure was reduced to 35 mmHg (p < 0.045) and below. There was also a significant interaction between blood flow changes and the ocular perfusion pressure treatment (p = 0.004, adjusted Greenhouse & Geisser univariate test), indicating the gradually enlarged blood flow difference between the two groups was due to the ocular perfusion pressure decrease. The results show that optic nerve head blood flow is more susceptible to an ocular perfusion pressure decrease induced by lowering the blood pressure compared with that induced by increasing the intraocular pressure. This blood flow autoregulation capacity vulnerability to low blood pressure may provide experimental evidence related to the hemodynamic pathophysiology in glaucoma.

A Rapid Capillary-Pressure Driven Micro-Channel to Demonstrate Newtonian Fluid Behavior of Zebrafish Blood at High Shear Rates.

PubMed

Lee, Juhyun; Chou, Tzu-Chieh; Kang, Dongyang; Kang, Hanul; Chen, Junjie; Baek, Kyung In; Wang, Wei; Ding, Yichen; Carlo, Dino Di; Tai, Yu-Chong; Hsiai, Tzung K

2017-05-16

Blood viscosity provides the rheological basis to elucidate shear stress underlying developmental cardiac mechanics and physiology. Zebrafish is a high throughput model for developmental biology, forward-genetics, and drug discovery. The micro-scale posed an experimental challenge to measure blood viscosity. To address this challenge, a microfluidic viscometer driven by surface tension was developed to reduce the sample volume required (3μL) for rapid (<2 min) and continuous viscosity measurement. By fitting the power-law fluid model to the travel distance of blood through the micro-channel as a function of time and channel configuration, the experimentally acquired blood viscosity was compared with a vacuum-driven capillary viscometer at high shear rates (>500 s -1 ), at which the power law exponent (n) of zebrafish blood was nearly 1 behaving as a Newtonian fluid. The measured values of whole blood from the micro-channel (4.17cP) and the vacuum method (4.22cP) at 500 s -1 were closely correlated at 27 °C. A calibration curve was established for viscosity as a function of hematocrits to predict a rise and fall in viscosity during embryonic development. Thus, our rapid capillary pressure-driven micro-channel revealed the Newtonian fluid behavior of zebrafish blood at high shear rates and the dynamic viscosity during development.

The Toxicity of Inhaled Sulphur Mustard

DTIC Science & Technology

2012-03-01

Pulse oximetry Mean arterial pressure Central venous pressure Blood Chemistry (arterial and venous ) pH pO2 pCO2 Sodium Potassium Calcium...Cardiovascular Parameters − CFI – Cardiac Function Index − CO – Cardiac Output − CvO2 – Mixed Venous Oxygenation − CVP – Central Venous Pressure...Data are expressed as mean ± SEM. Changes in central venous pressure following exposure to HD: HD controls () and HD + NAC (). Data are

Low Blood Pressure

MedlinePlus

... a problem. Sometimes blood pressure that is too low can also cause problems. Blood pressure is the ... reading is 90/60 or lower, you have low blood pressure. Some people have low blood pressure ...

The relationship between oxidized serum albumin and blood pressure in hypoalbuminemic peritoneal dialysis patients.

PubMed

Hasan, Kamal; Hassan, Fadi; Michelis, Regina

2017-01-01

Oxidative stress produces molecular modifications of serum albumin that disturb its biological functions and interfere with its detection by the bromocresol green assay (BCG). Oxidative stress, inflammation, and hypoalbuminemia are common peritoneal dialysis (PD). This study aimed to evaluate the relationship between serum albumin, oxidized serum albumin (OSA), oncotic pressure, and blood pressure in hypoalbuminemic PD patients. Twenty-four PD patients with serum albumin levels <3.5 g/dl enrolled in the study. Data were compared between participants with the mean arterial pressure (MAP) <105 mmHg (n = 12) and MAP ≥ 105 mmHg (n = 12). Serum albumin levels were ≤3.0 g/dl and similar in both groups (p = 0.298). The calculated OSA and oncotic pressure were significantly higher in patients with MAP ≥ 105 mmHg than in those with MAP < 105 mmHg. MAP was positively and marginally correlated with serum albumin levels (measured by BCG) (r = 0.34, p = 0.05), and positively and significantly correlated with the calculated OSA and oncotic pressure (r = 0.44, p = 0.015, r = 0.58, p = 0.002; respectively). The oncotic pressure was positively correlated with the calculated OSA (r = 0.47, p = 0.011). OSA, undetectable by the commonly used BCG, may contribute to higher blood pressure in hypoalbuminemic PD patients.

Effects of increasing left ventricular filling pressure in patients with acute myocardial infarction

PubMed Central

Russell, Richard O.; Rackley, Charles E.; Pombo, Jaoquin; Hunt, David; Potanin, Constantine; Dodge, Harold T.

1970-01-01

Left ventricular performance in 19 patients with acute myocardial infarction has been evaluated by measuring left ventricular response in terms of cardiac output, stroke volume, work, and power to progressive elevation of filling pressure accomplished by progressive expansion of blood volume with rapid infusion of low molecular weight dextran. Such infusion can elevate the cardiac output, stroke volume, work, and power and thus delineate the function of the left ventricle by Frank-Starling function curves. Left ventricular filling pressure in the range of 20-24 mm Hg was associated with the peak of the curves and when the filling pressure exceeded this range, the curves became flattened or decreased. An increase in cardiac output could be maintained for 4 or more hr. Patients with a flattened function curve had a high mortality in the ensuing 8 wk. The function curve showed improvement in myocardial function during the early convalescence. When left ventricular filling pressure is monitored directly or as pulmonary artery end-diastolic pressure, low molecular weight dextran provides a method for assessment of left ventricular function. Images PMID:5431663

Abnormal cardiovascular response to exercise in hypertension: contribution of neural factors.

PubMed

Mitchell, Jere H

2017-06-01

During both dynamic (e.g., endurance) and static (e.g., strength) exercise there are exaggerated cardiovascular responses in hypertension. This includes greater increases in blood pressure, heart rate, and efferent sympathetic nerve activity than in normal controls. Two of the known neural factors that contribute to this abnormal cardiovascular response are the exercise pressor reflex (EPR) and functional sympatholysis. The EPR originates in contracting skeletal muscle and reflexly increases sympathetic efferent nerve activity to the heart and blood vessels as well as decreases parasympathetic efferent nerve activity to the heart. These changes in autonomic nerve activity cause an increase in blood pressure, heart rate, left ventricular contractility, and vasoconstriction in the arterial tree. However, arterial vessels in the contracting skeletal muscle have a markedly diminished vasoconstrictor response. The markedly diminished vasoconstriction in contracting skeletal muscle has been termed functional sympatholysis. It has been shown in hypertension that there is an enhanced EPR, including both its mechanoreflex and metaboreflex components, and an impaired functional sympatholysis. These conditions set up a positive feedback or vicious cycle situation that causes a progressively greater decrease in the blood flow to the exercising muscle. Thus these two neural mechanisms contribute significantly to the abnormal cardiovascular response to exercise in hypertension. In addition, exercise training in hypertension decreases the enhanced EPR, including both mechanoreflex and metaboreflex function, and improves the impaired functional sympatholysis. These two changes, caused by exercise training, improve the muscle blood flow to exercising muscle and cause a more normal cardiovascular response to exercise in hypertension. Copyright © 2017 the American Physiological Society.

Pressure-driven occlusive flow of a confined red blood cell.

PubMed

Savin, Thierry; Bandi, M M; Mahadevan, L

2016-01-14

When red blood cells (RBCs) move through narrow capillaries in the microcirculation, they deform as they flow. In pathophysiological processes such as sickle cell disease and malaria, RBC motion and flow are severely restricted. To understand this threshold of occlusion, we use a combination of experiment and theory to study the motion of a single swollen RBC through a narrow glass capillary of varying inner diameter. By tracking the movement of the squeezed cell as it is driven by a controlled pressure drop, we measure the RBC velocity as a function of the pressure gradient as well as the local capillary diameter, and find that the effective blood viscosity in this regime increases with both decreasing RBC velocity and tube radius by following a power-law that depends upon the length of the confined cell. Our observations are consistent with a simple elasto-hydrodynamic model and highlight the role of lateral confinement in the occluded pressure-driven slow flow of soft confined objects.

Inhibitory effects of losartan and azelnidipine on augmentation of blood pressure variability induced by angiotensin II in rats.

PubMed

Jiang, Danfeng; Kawagoe, Yukiko; Kuwasako, Kenji; Kitamura, Kazuo; Kato, Johji

2017-07-05

Increased blood pressure variability has been shown to be associated with cardiovascular morbidity and mortality. Recently we reported that continuous infusion of angiotensin II not only elevated blood pressure level, but also increased blood pressure variability in a manner assumed to be independent of blood pressure elevation in rats. In the present study, the effects of the angiotensin type I receptor blocker losartan and the calcium channel blocker azelnidipine on angiotensin II-induced blood pressure variability were examined and compared with that of the vasodilator hydralazine in rats. Nine-week-old male Wistar rats were subcutaneously infused with 240 pmol/kg/min angiotensin II for two weeks without or with oral administration of losartan, azelnidipine, or hydralazine. Blood pressure variability was evaluated using a coefficient of variation of blood pressure recorded every 15min under an unrestrained condition via an abdominal aortic catheter by a radiotelemetry system. Treatment with losartan suppressed both blood pressure elevation and augmentation of systolic blood pressure variability in rats infused with angiotensin II at 7 and 14 days. Azelnidipine also inhibited angiotensin II-induced blood pressure elevation and augmentation of blood pressure variability; meanwhile, hydralazine attenuated the pressor effect of angiotensin II, but had no effect on blood pressure variability. In conclusion, angiotensin II augmented blood pressure variability in an angiotensin type 1 receptor-dependent manner, and azelnidipine suppressed angiotensin II-induced augmentation of blood pressure variability, an effect mediated by the mechanism independent of the blood pressure-lowering action. Copyright © 2017 Elsevier B.V. All rights reserved.

Blood pressure responses to LBNP in nontrained and trained hypertensive rats

NASA Technical Reports Server (NTRS)

Bedford, T. G.; Tipton, C. M.

1992-01-01

To study the influences of 16 wk of endurance training on the reflex regulation of resting blood pressure, nontrained (NT) and trained (T) female hypertensive rats (SHR) were subjected to conditions of lower body negative pressure (LBNP). Measurements of muscle cytochrome oxidase activity and run time to exhaustion indicated that the animals were endurance trained. The rats (NT = 6, T = 7) were tranquilized with 300-600 micrograms.kg-1 diazepam (IV) before heart rates and blood pressures were measured over a range of 2.5-10.0 mm Hg of negative pressure. When subjected to conditions of LBNP, the reflex tachycardia of the T group was greater than the NT at the lower (-2.5 and -5.0 mm Hg) negative pressures. Although arterial pressure declines were similar in both groups, the T group experienced significantly less of a decline in central venous pressure than the NT animals. When chlorisondamine was used as a ganglionic blocker (2.5 mg.kg-1, IV), the fall in CVP at 10 mm Hg negative pressure was greater for the NT group while the fall in the initial systemic arterial pressure was more for the T group. From these results we concluded that training had altered the interaction between cardiopulmonary and arterial baroreflexes in these hypertensive rats and a nonneural component had been altered such as cardiac function.

[The association between blood pressure variability and sleep stability in essential hypertensive patients with sleep disorder].

PubMed

Zhu, Y Q; Long, Q; Xiao, Q F; Zhang, M; Wei, Y L; Jiang, H; Tang, B

2018-03-13

Objective: To investigate the association of blood pressure variability and sleep stability in essential hypertensive patients with sleep disorder by cardiopulmonary coupling. Methods: Performed according to strict inclusion and exclusion criteria, 88 new cases of essential hypertension who came from the international department and the cardiology department of china-japan friendship hospital were enrolled. Sleep stability and 24 h ambulatory blood pressure data were collected by the portable sleep monitor based on cardiopulmonary coupling technique and 24 h ambulatory blood pressure monitor. Analysis the correlation of blood pressure variability and sleep stability. Results: In the nighttime, systolic blood pressure standard deviation, systolic blood pressure variation coefficient, the ratio of the systolic blood pressure minimum to the maximum, diastolic blood pressure standard deviation, diastolic blood pressure variation coefficient were positively correlated with unstable sleep duration ( r =0.185, 0.24, 0.237, 0.43, 0.276, P <0.05). Conclusions: Blood pressure variability is associated with sleep stability, especially at night, the longer the unstable sleep duration, the greater the variability in night blood pressure.

Abnormal blood pressure circadian rhythm in acute ischaemic stroke: are lacunar strokes really different?

PubMed

Castilla-Guerra, L; Espino-Montoro, A; Fernández-Moreno, M C; López-Chozas, J M

2009-08-01

A pathologically reduced or abolished circadian blood pressure variation has been described in acute stroke. However, studies on alterations of circadian blood pressure patterns after stroke and stroke subtypes are scarce. The objective of this study was to evaluate the changes in circadian blood pressure patterns in patients with acute ischaemic stroke and their relation to the stroke subtype. We studied 98 consecutive patients who were admitted within 24 h after ischaemic stroke onset. All patients had a detailed clinical examination, laboratory studies and a CT scan study of the brain on admission. To study the circadian rhythm of blood pressure, a continuous blood pressure monitor (Spacelab 90217) was used. Patients were classified according to the percentage fall in the mean systolic blood pressure or diastolic blood pressure at night compared with during the day as: dippers (fall> or =10-20%); extreme dippers (> or =20%); nondipper (<10%); and reverse dippers (<0%, that is, an increase in the mean nocturnal blood pressure compared with the mean daytime blood pressure). Data were separated and analysed in two groups: lacunar and nonlacunar infarctions. Statistical testing was conducted using the SSPS 12.0. Methods We studied 60 males and 38 females, mean age: 70.5+/-11 years. The patient population consisted of 62 (63.2%) lacunar strokes and 36 (36.8%) nonlacunar strokes. Hypertension was the most common risk factor (67 patients, 68.3%). Other risk factors included hypercholesterolaemia (44 patients, 44.8%), diabetes mellitus (38 patients, 38.7%), smoking (24 patients, 24.8%) and atrial fibrillation (19 patients, 19.3%). The patients with lacunar strokes were predominantly men (P=0.037) and had a lower frequency of atrial fibrillation (P=0.016) as compared with nonlacunar stroke patients. In the acute phase, the mean systolic blood pressure was 136+/-20 mmHg and diastolic blood pressure was 78.7+/-11.8. Comparing stroke subtypes, there were no differences in 24-h systolic blood pressure and 24-h diastolic blood pressure between patients with lacunar and nonlacunar infarction. However, patients with lacunar infarction showed a mean decline in day-night systolic blood pressure and diastolic blood pressure of approximately 4 mmHg [systolic blood pressure: 3.9 (SD 10) mmHg, P=0.003; diastolic blood pressure 3.7 (SD 7) mmHg, P=0.0001] compared with nonlacunar strokes. Nonlacunar strokes showed a lack of 24-h nocturnal systolic blood pressure and diastolic blood pressure fall. The normal diurnal variation in systolic blood pressure was abolished in 87 (88.9%) patients, and the variation in diastolic blood pressure was abolished in 76 (77.5%) patients. On comparing lacunar and nonlacunar strokes, we found that the normal diurnal variation in systolic blood pressure was abolished in 53 (85.4%) lacunar strokes and in 34 (94.4%) nonlacunar strokes (P=nonsignificant). In terms of diurnal variation in diastolic blood pressure, it was abolished in 43 (69.3%) lacunar strokes and in 33 (91.6%) nonlacunar strokes (P=0.026). Our results show clear differences in the blood pressure circadian rhythm of acute ischaemic stroke between lacunar and nonlacunar infarctions by means of 24-h blood pressure monitoring. The magnitude of nocturnal systolic and diastolic blood pressure dip was significantly higher in lacunar strokes. Besides, patients with lacunar strokes presented a higher percentage of dipping patterns in the diastolic blood pressure circadian rhythm. Therefore, one should consider the ischaemic stroke subtype when deciding on the management of blood pressure in acute stroke.

Lower blood pressure and apathy coincide in older persons with poorer functional ability: the Discontinuation of Antihypertensive Treatment in Elderly People (DANTE) Study Leiden.

PubMed

Moonen, Justine E F; Bertens, Anne Suzanne; Foster-Dingley, Jessica C; Smit, Roelof A J; van der Grond, Jeroen; de Craen, Anton J M; de Ruijter, Wouter; van der Mast, Roos C

2015-01-01

To examine the association between blood pressure (BP) measures and symptoms of apathy and depression in older adults with various levels of functional ability. Cross-sectional study using baseline data from the Discontinuation of Antihypertensive Treatment in Elderly people (DANTE) Study Leiden. Primary care setting, the Netherlands. Community-dwelling individuals aged 75 and older (N = 430). Systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP) were measured during home visits. Symptoms of apathy and depression were assessed using the Apathy Scale and the Geriatric Depression Scale (GDS-15), respectively. Stratified linear regression was performed in participants with better and worse functional ability according to the median of the Groningen Activity Restriction Scale. In participants with lower functional ability, each 10-mmHg lower SBP, DBP, and MAP was associated with higher Apathy Scale scores (0.63, 0.92, and 0.94 points, respectively, all P < .005) but not with GDS-15 scores. In participants with higher functional ability, BP measures were not associated with Apathy Scale or GDS-15 scores. In older participants with poorer functional ability, lower BP was associated with more symptoms of apathy but not depression. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

High Blood Pressure and Kidney Disease

MedlinePlus

... Your Kidneys & How They Work High Blood Pressure & Kidney Disease What is high blood pressure? Blood pressure ... have their blood pressure checked. What are the kidneys and what do they do? The kidneys are ...

A low-carbohydrate/high-fat diet reduces blood pressure in spontaneously hypertensive rats without deleterious changes in insulin resistance.

PubMed

Bosse, John D; Lin, Han Yi; Sloan, Crystal; Zhang, Quan-Jiang; Abel, E Dale; Pereira, Troy J; Dolinsky, Vernon W; Symons, J David; Jalili, Thunder

2013-06-15

Previous studies reported that diets high in simple carbohydrates could increase blood pressure in rodents. We hypothesized that the converse, a low-carbohydrate/high-fat diet, might reduce blood pressure. Six-week-old spontaneously hypertensive rats (SHR; n = 54) and Wistar-Kyoto rats (WKY; n = 53, normotensive control) were fed either a control diet (C; 10% fat, 70% carbohydrate, 20% protein) or a low-carbohydrate/high-fat diet (HF; 20% carbohydrate, 60% fat, 20% protein). After 10 wk, SHR-HF had lower (P < 0.05) mean arterial pressure than SHR-C (148 ± 3 vs. 159 ± 3 mmHg) but a similar degree of cardiac hypertrophy (33.4 ± 0.4 vs. 33.1 ± 0.4 heart weight/tibia length, mg/mm). Mesenteric arteries and the entire aorta were used to assess vascular function and endothelial nitric oxide synthase (eNOS) signaling, respectively. Endothelium-dependent (acetylcholine) relaxation of mesenteric arteries was improved (P < 0.05) in SHR-HF vs. SHR-C, whereas contraction (potassium chloride, phenylephrine) was reduced (P < 0.05). Phosphorylation of eNOSSer1177 increased (P < 0.05) in arteries from SHR-HF vs. SHR-C. Plasma glucose, insulin, and homoeostatic model of insulin assessment were lower (P < 0.05) in SHR-HF vs. SHR-C, whereas peripheral insulin sensitivity (insulin tolerance test) was similar. After a 10-h fast, insulin stimulation (2 U/kg ip) increased (P < 0.05) phosphorylation of AktSer473 and S6 in heart and gastrocnemius similarly in SHR-C vs. SHR-HF. In conclusion, a low-carbohydrate/high-fat diet reduced blood pressure and improved arterial function in SHR without producing signs of insulin resistance or altering insulin-mediated signaling in the heart, skeletal muscle, or vasculature.

A low-carbohydrate/high-fat diet reduces blood pressure in spontaneously hypertensive rats without deleterious changes in insulin resistance

PubMed Central

Bosse, John D.; Lin, Han Yi; Sloan, Crystal; Zhang, Quan-Jiang; Abel, E. Dale; Pereira, Troy J.; Dolinsky, Vernon W.; Symons, J. David

2013-01-01

Previous studies reported that diets high in simple carbohydrates could increase blood pressure in rodents. We hypothesized that the converse, a low-carbohydrate/high-fat diet, might reduce blood pressure. Six-week-old spontaneously hypertensive rats (SHR; n = 54) and Wistar-Kyoto rats (WKY; n = 53, normotensive control) were fed either a control diet (C; 10% fat, 70% carbohydrate, 20% protein) or a low-carbohydrate/high-fat diet (HF; 20% carbohydrate, 60% fat, 20% protein). After 10 wk, SHR-HF had lower (P < 0.05) mean arterial pressure than SHR-C (148 ± 3 vs. 159 ± 3 mmHg) but a similar degree of cardiac hypertrophy (33.4 ± 0.4 vs. 33.1 ± 0.4 heart weight/tibia length, mg/mm). Mesenteric arteries and the entire aorta were used to assess vascular function and endothelial nitric oxide synthase (eNOS) signaling, respectively. Endothelium-dependent (acetylcholine) relaxation of mesenteric arteries was improved (P < 0.05) in SHR-HF vs. SHR-C, whereas contraction (potassium chloride, phenylephrine) was reduced (P < 0.05). Phosphorylation of eNOSSer1177 increased (P < 0.05) in arteries from SHR-HF vs. SHR-C. Plasma glucose, insulin, and homoeostatic model of insulin assessment were lower (P < 0.05) in SHR-HF vs. SHR-C, whereas peripheral insulin sensitivity (insulin tolerance test) was similar. After a 10-h fast, insulin stimulation (2 U/kg ip) increased (P < 0.05) phosphorylation of AktSer473 and S6 in heart and gastrocnemius similarly in SHR-C vs. SHR-HF. In conclusion, a low-carbohydrate/high-fat diet reduced blood pressure and improved arterial function in SHR without producing signs of insulin resistance or altering insulin-mediated signaling in the heart, skeletal muscle, or vasculature. PMID:23604708

Integrative regulation of human brain blood flow

PubMed Central

Willie, Christopher K; Tzeng, Yu-Chieh; Fisher, Joseph A; Ainslie, Philip N

2014-01-01

Herein, we review mechanisms regulating cerebral blood flow (CBF), with specific focus on humans. We revisit important concepts from the older literature and describe the interaction of various mechanisms of cerebrovascular control. We amalgamate this broad scope of information into a brief review, rather than detailing any one mechanism or area of research. The relationship between regulatory mechanisms is emphasized, but the following three broad categories of control are explicated: (1) the effect of blood gases and neuronal metabolism on CBF; (2) buffering of CBF with changes in blood pressure, termed cerebral autoregulation; and (3) the role of the autonomic nervous system in CBF regulation. With respect to these control mechanisms, we provide evidence against several canonized paradigms of CBF control. Specifically, we corroborate the following four key theses: (1) that cerebral autoregulation does not maintain constant perfusion through a mean arterial pressure range of 60–150 mmHg; (2) that there is important stimulatory synergism and regulatory interdependence of arterial blood gases and blood pressure on CBF regulation; (3) that cerebral autoregulation and cerebrovascular sensitivity to changes in arterial blood gases are not modulated solely at the pial arterioles; and (4) that neurogenic control of the cerebral vasculature is an important player in autoregulatory function and, crucially, acts to buffer surges in perfusion pressure. Finally, we summarize the state of our knowledge with respect to these areas, outline important gaps in the literature and suggest avenues for future research. PMID:24396059

Introversion associated with large differences between screening blood pressure and home blood pressure measurement: The Ohasama study.

PubMed

Hozawa, Atsushi; Ohkubo, Takayoshi; Obara, Taku; Metoki, Hirohito; Kikuya, Masahiro; Asayama, Kei; Totsune, Kazuhito; Hashimoto, Junichiro; Hoshi, Haruhisa; Arai, Yumiko; Satoh, Hiroshi; Hosokawa, Toru; Imai, Yutaka

2006-11-01

To explore the effect of personality on screening blood pressures measured in clinical settings and home blood pressure measurements. From 1997 to 1999, 699 participants underwent screening and home blood pressure measurements and completed the Japanese version of the short-form Eysenck personality questionnaire. An increased screening blood pressure was defined as screening blood pressure > or = 140/90 mmHg and an increased home blood pressure was defined as home blood pressure > or = 135/85 mmHg. Participants with lower extroversion scores (i.e., introversion) showed a greater difference between screening and home systolic blood pressure. The association between introversion and differences was statistically significant, even after adjustment for other possible factors (younger age, female, wide screening pulse pressure, never smoked, and no antihypertensive medication). The adjusted means of SBP differences were 7.3 and 4.4 mmHg among the lowest and highest extroversion quartiles, respectively (P for trend = 0.02). Other personality scores (psychoticism or neuroticism) were not associated with screening and home blood pressure differences. The incorporation of an extroversion score in the basic model consisting of the above factors that affected the difference between screening and home blood pressure slightly improved the prediction of a high home blood pressure. The area under the receiver operating characteristic curve increased by 0.037 among participants with high screening blood pressure and 0.006 for those with normal screening blood pressure compared with the basic model. Physicians may need to be aware of 'introverted' patients who have high blood pressure in clinic settings, because they have the potential for 'white-coat' hypertension.

Endurance training in mild hypertension - effects on ambulatory blood pressure and neural circulatory control.

PubMed

Narkiewicz; Somers

1997-10-01

This review examines the effects of a single bout of exercise and of endurance training on blood pressure in patients with hypertension. Possible autonomic mechanisms that mediate these changes in blood pressure are reviewed briefly. Blood pressure rises during exercise. During the second half hour after exercise blood pressure is lower. This p;ost-exercise reduction in blood pressure is associated with a decrease in muscle sympathetic nerve activity, an increase in baroreflex gain and a reduction in the level of blood pressure (set point) at which baroreflex activation occurs. The post-exercise fall in blood pressure appears to be limited to several hours and is not likely to explain any chronic reduction in blood pressure from endurance training. Endurance training elicits modest (approximately 4-5 mmHg) reductions in blood pressure. Because of the intrinsic variability of blood pressure, the decreases in blood pressure after endurance training is evident, especially when multiple measurements of blood pressure are obtained. Studies using 24 h blood pressure measurements suggest that, although endurance training lowers daytime blood pressure, blood pressure during sleep remains unchanged. The mechanism underlying the reduction in blood pressure in endurance training is not known. Although physical fitness is known to attenuate the sympathetic response to acute exercise, whether resting sympathetic drive is decreased with endurance training remains controversial. The slowing of heart rate that accompanies endurance training is also associated with an increase in variability of heart rate. The slower heart rate, increased variability of heart rate and lower blood pressure after endurance training are accompanied by an increase in baroreflex sensitivity. Even though the antihypertensive effect of endurance training is modest, the favourable effects of physical fitness on other risk factors for cardiovascular disease make exercise training an important approach in the management of hypertensive patients, particularly for sedentary patients with borderline and mild hypertension.

Self-Esteem and the Acute Effect of Anxiety on Ambulatory Blood Pressure.

PubMed

Edmondson, Donald; Arndt, Jamie; Alcántara, Carmela; Chaplin, William; Schwartz, Joseph E

2015-09-01

Recent research suggests that self-esteem may be associated with improved parasympathetic nervous system functioning. This study tested whether high self-esteem is associated with decreased ambulatory systolic blood pressure (ASBP) reactivity to anxiety in healthy adults during the waking hours of a normal day. Each of 858 participants completed a short version of the Rosenberg Self-Esteem Scale and then wore an ABP monitor that took two blood pressure readings per hour for 24 hours. Immediately after each blood pressure reading, participants completed an electronic diary report that included an anxiety rating on a 100-point visual analog scale. Using multilevel models, we assessed the association of momentary anxiety, high trait self-esteem, and their interaction on momentary ASBP, with adjustment for age, sex, race, ethnicity, and body mass index. Sensitivity analyses were conducted examining psychological factors associated with self-esteem: sense of mastery, optimism, social support, and depressive symptoms. On average, a 1-point increase in cube root-transformed anxiety was associated with a 0.80-mm Hg (standard error = 0.09, p < .001) increase in ASBP, and the interaction of high self-esteem and momentary anxiety was significant, such that this effect was 0.48 (standard error = 0.20, p = .015) less in individuals with high self-esteem compared with all others. Results for self-esteem remained significant when adjusting for sex and psychological factors. Momentary increases in anxiety are associated with acute increases in ASBP, and high self-esteem buffers the effect of momentary anxiety on blood pressure. Thus, high self-esteem may confer cardiovascular benefit by reducing the acute effects of anxiety on systolic blood pressure.

Self-esteem and the acute effect of anxiety on ambulatory blood pressure

PubMed Central

Edmondson, Donald; Arndt, Jamie; Alcántara, Carmela; Chaplin, William; Schwartz, Joseph E

2015-01-01

Objective Recent research suggests that self-esteem may be associated with improved parasympathetic nervous system functioning. This study tested whether high self-esteem is associated with decreased ambulatory systolic blood pressure (ASBP) reactivity to anxiety in healthy adults during the waking hours of a normal day. Methods Each of 858 participants completed a short version of the Rosenberg Self-Esteem Scale and then wore an ABP monitor which took two blood pressure readings per hour for 24 hours. Immediately after each blood pressure reading, participants completed an electronic diary report that included an anxiety rating on a 100-point visual analog scale (VAS). Using multilevel models, we assessed the association of momentary anxiety, high trait self-esteem, and their interaction on momentary ASBP, with adjustment for age, sex, race, ethnicity, and body mass index. Sensitivity analyses were conducted examining psychological factors associated with self-esteem: sense of mastery, optimism, social support, and depressive symptoms. Results On average, a 1-point increase in cube root-transformed anxiety was associated with a 0.80 mmHg (SE=0.09, p<0.001) increase in ASBP, and the interaction of high self-esteem and momentary anxiety was significant, such that this effect was 0.48 (SE=0.20, p=0.015) less in individuals with high self-esteem compared to all others. Results for self-esteem remained significant when adjusting for sex and psychological factors. Conclusions Momentary increases in anxiety are associated with acute increases in ASBP, and high self-esteem buffers the effect of momentary anxiety on blood pressure. Thus, high self-esteem may confer cardiovascular benefit by reducing the acute effects of anxiety on systolic blood pressure. PMID:26230481

Impact of changes in blood pressure during the treatment of acute decompensated heart failure on renal and clinical outcomes†

PubMed Central

Testani, Jeffrey M.; Coca, Steven G.; McCauley, Brian D.; Shannon, Richard P.; Kimmel, Stephen E.

2011-01-01

Aims One of the primary determinants of blood flow in regional vascular beds is perfusion pressure. Our aim was to investigate if reduction in blood pressure during the treatment of decompensated heart failure would be associated with worsening renal function (WRF). Our secondary aim was to evaluate the prognostic significance of this potentially treatment-induced form of WRF. Methods and results Subjects included in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial limited data were studied (386 patients). Reduction in systolic blood pressure (SBP) was greater in patients experiencing WRF (−10.3 ± 18.5 vs. −2.8 ± 16.0 mmHg, P < 0.001) with larger reductions associated with greater odds for WRF (odds ratio = 1.3 per 10 mmHg reduction, P < 0.001). Systolic blood pressure reduction (relative change > median) was associated with greater doses of in-hospital oral vasodilators (P ≤ 0.017), thiazide diuretic use (P = 0.035), and greater weight reduction (P = 0.023). In patients with SBP-reduction, WRF was not associated with worsened survival [adjusted hazard ratio (HR) = 0.76, P = 0.58]. However, in patients without SBP-reduction, WRF was strongly associated with increased mortality (adjusted HR = 5.3, P < 0.001, P interaction = 0.001). Conclusion During the treatment of decompensated heart failure, significant blood pressure reduction is strongly associated with WRF. However, WRF that occurs in the setting of SBP-reduction is not associated with an adverse prognosis, whereas WRF in the absence of this provocation is strongly associated with increased mortality. These data suggest that WRF may represent the final common pathway of several mechanistically distinct processes, each with potentially different prognostic implications. PMID:21693504

Impact of changes in blood pressure during the treatment of acute decompensated heart failure on renal and clinical outcomes.

PubMed

Testani, Jeffrey M; Coca, Steven G; McCauley, Brian D; Shannon, Richard P; Kimmel, Stephen E

2011-08-01

One of the primary determinants of blood flow in regional vascular beds is perfusion pressure. Our aim was to investigate if reduction in blood pressure during the treatment of decompensated heart failure would be associated with worsening renal function (WRF). Our secondary aim was to evaluate the prognostic significance of this potentially treatment-induced form of WRF. Subjects included in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial limited data were studied (386 patients). Reduction in systolic blood pressure (SBP) was greater in patients experiencing WRF (-10.3 ± 18.5 vs. -2.8 ± 16.0 mmHg, P < 0.001) with larger reductions associated with greater odds for WRF (odds ratio = 1.3 per 10 mmHg reduction, P < 0.001). Systolic blood pressure reduction (relative change > median) was associated with greater doses of in-hospital oral vasodilators (P ≤ 0.017), thiazide diuretic use (P = 0.035), and greater weight reduction (P = 0.023). In patients with SBP-reduction, WRF was not associated with worsened survival [adjusted hazard ratio (HR) = 0.76, P = 0.58]. However, in patients without SBP-reduction, WRF was strongly associated with increased mortality (adjusted HR = 5.3, P < 0.001, P interaction = 0.001). During the treatment of decompensated heart failure, significant blood pressure reduction is strongly associated with WRF. However, WRF that occurs in the setting of SBP-reduction is not associated with an adverse prognosis, whereas WRF in the absence of this provocation is strongly associated with increased mortality. These data suggest that WRF may represent the final common pathway of several mechanistically distinct processes, each with potentially different prognostic implications.

[Dark or white chocolate? Cocoa and cardiovascular health].

PubMed

Corti, Roberto; Perdrix, Jean; Flammer, Andreas J; Noll, Georg

2010-03-10

Epidemiological data show that a regular dietary intake of plant-derived foods reduces the risk of cardiovascular disease. Recent research indeed demonstrates interesting data about cocoa consumption, with high concentrations of polyphenols, and beneficial effects on blood pressure, insulin resistance and platelet function. Although still debated, a range of potential mechanisms through which cocoa might exert their benefits on cardiovascular health have been suggested: activation of nitric oxide, antioxidant, anti-inflammatory, anti-platelet effects, which might in turn improve endothelial function, lipid levels, blood pressure and insulin resistance. This article reviews available data about the effects of the consumption of cocoa and different types of chocolate on cardiovascular health, and outlines potential mechanisms involved on the basis of recent studies.

Effect of cold air inhalation and isometric exercise on coronary blood flow and myocardial function in humans

PubMed Central

Muller, Matthew D.; Gao, Zhaohui; Drew, Rachel C.; Herr, Michael D.; Leuenberger, Urs A.

2011-01-01

The effects of cold air inhalation and isometric exercise on coronary blood flow are currently unknown, despite the fact that both cold air and acute exertion trigger angina in clinical populations. In this study, we used transthoracic Doppler echocardiography to measure coronary blood flow velocity (CBV; left anterior descending coronary artery) and myocardial function during cold air inhalation and handgrip exercise. Ten young healthy subjects underwent the following protocols: 5 min of inhaling cold air (cold air protocol), 5 min of inhaling thermoneutral air (sham protocol), 2 min of isometric handgrip at 30% of maximal voluntary contraction (grip protocol), and 5 min of isometric handgrip at 30% maximal voluntary contraction while breathing cold air (cold + grip protocol). Heart rate, blood pressure, inspired air temperature, CBV, myocardial function (tissue Doppler imaging), O2 saturation, and pulmonary function were measured. The rate-pressure product (RPP) was used as an index of myocardial O2 demand, whereas CBV was used as an index of myocardial O2 supply. Compared with the sham protocol, the cold air protocol caused a significantly higher RPP, but there was a significant reduction in CBV. The cold + grip protocol caused a significantly greater increase in RPP compared with the grip protocol (P = 0.045), but the increase in CBV was significantly less (P = 0.039). However, myocardial function was not impaired during the cold + grip protocol relative to the grip protocol alone. Collectively, these data indicate that there is a supply-demand mismatch in the coronary vascular bed when cold ambient air is breathed during acute exertion but myocardial function is preserved, suggesting an adequate redistribution of blood flow. PMID:21940852

The Role of Central Blood Pressure Monitoring in the Management of Hypertension.

PubMed

Ochoa, Adrian; Patarroyo-Aponte, Gabriel; Rahman, Mahboob

2018-04-19

Central blood pressure is a novel predictor of cardiovascular risk that can be measured in the clinical setting using currently available technology. This paper will review current available methods of central blood pressure monitoring as well as its impact in cardiac and renal disease. Both aortic and carotid systolic blood pressure are independently associated with cardiovascular mortality and serious cardiac events. Furthermore, studies show that systolic aortic blood pressure has been shown to be superior predictor of cardiovascular as compared to brachial blood pressure. Inhibitors of the renin angiotensin axis may have a beneficial effect on central blood pressure; however, long term studies evaluating the impact of lowering central blood pressure on clinical outcomes are lacking. Central blood pressure is a good predictor of cardiovascular risk. As more studies emerge demonstrating the value of central blood pressure as a therapeutic target, it is possible that targeting central blood pressure may become an important part of the armamentarium to lower cardiovascular risk.

A Flight Evaluation of an Airborne Physiological Instrumentation System, Including Preliminary Results Under Conditions of Varying Accelerations

NASA Technical Reports Server (NTRS)

Smedal, Harald A.; Holden, George R.; Smith, Joseph R., Jr.

1960-01-01

A physiological instrumentation system capable of recording the electrocardiogram, pulse rate, respiration rate, and systolic and diastolic blood pressures during flight has been developed. This instrumentation system was designed for use during control studies at varied levels of acceleration in order to monitor the well-being of the pilot and at the same time to obtain data for study of the relationships between his various physiological functions and his performance capability. Flights, made in a T-33 aircraft, demonstrated the ability of the system to obtain the desired physiological data in flight. The data obtained in these flights, although limited in nature, indicate a slowing of the pulse rate under the subgravity conditions of brief duration. There appeared to be a proportional nearly in-phase relationship between pulse rate and acceleration. A decrease in diastolic blood pressure together with an increase in pulse pressure was noted during subgravity conditions and an elevation of the diastolic pressure together with a decrease in pulse pressure du-ring increased accelerations. No change worthy of note was seen in the records of the systolic blood pressure, the respiration rate, or the electrocardiogram over the range of acceleration studied (0 to 3 g).

Influence of mental stress on the plasma homocysteine level and blood pressure change in young men.

PubMed

Sawai, Asuka; Ohshige, Kenji; Kura, Naoki; Tochikubo, Osamu

2008-04-01

Objective. This study aimed to determine whether mental stress influences the plasma total homocysteine level or blood pressure in young men. Method. Twenty-seven male university students were assigned to a normal blood pressure group (24-h systolic blood pressure <125 mmHg and diastolic blood pressure <75 mmHg; 13 subjects) or a high blood pressure group (24-h systolic blood pressure > or =125 mmHg, or 24-h diastolic blood pressure > or =75 mmHg; 14 subjects). Wearing an ambulatory blood pressure monitoring device, subjects rested for 30 minutes, underwent an arithmetic test for 15 minutes, and rested again for 15 minutes. Blood samples were taken before and after the test. Plasma total homocysteine levels were measured. Heart rate, blood pressure, and sympathovagal balance were determined during the test. Results. The mean total homocysteine level at rest in the high blood pressure group was slightly, but not significantly, higher than that in the normal blood pressure group. The resting total homocysteine level was significantly higher in subjects with parental history of hypertension than in those without (p < 0.01). Blood pressure, heart rate, and the plasma total homocysteine level were increased significantly by mental stress (p < 0.05). The change in total homocysteine correlated significantly with the changes in systolic blood pressure and sympathovagal balance (p < 0.05). Conclusion. Resting total homocysteine level was significantly higher in male students with a parental history of hypertension than in those without. It was shown that mental stress elevates heart rate, blood pressure, sympathovagal activity, and the plasma total homocysteine level in young men.

Inorganic nitrate ingestion improves vascular compliance but does not alter flow-mediated dilatation in healthy volunteers

PubMed Central

Bahra, M.; Kapil, V.; Pearl, V.; Ghosh, S.; Ahluwalia, A.

2012-01-01

Ingestion of inorganic nitrate elevates blood and tissue levels of nitrite via bioconversion in the entero-salivary circulation. Nitrite is converted to NO in the circulation, and it is this phenomenon that is thought to underlie the beneficial effects of inorganic nitrate in humans. Our previous studies have demonstrated that oral ingestion of inorganic nitrate decreases blood pressure and inhibits the transient endothelial dysfunction caused by ischaemia–reperfusion injury in healthy volunteers. However, whether inorganic nitrate might improve endothelial function per se in the absence of a pathogenic stimulus and whether this might contribute to the blood pressure lowering effects is yet unknown. We conducted a randomised, double-blind, crossover study in 14 healthy volunteers to determine the effects of oral inorganic nitrate (8 mmol KNO3) vs. placebo (8 mmol KCl) on endothelial function, measured by flow-mediated dilatation (FMD) of the brachial artery, prior to and 3 h following capsule ingestion. In addition, blood pressure (BP) was measured and aortic pulse wave velocity (aPWV) determined. Finally, blood, saliva and urine samples were collected for chemiluminescence analysis of [nitrite] and [nitrate] prior to and 3 h following interventions. Inorganic nitrate supplementation had no effect on endothelial function in healthy volunteers (6.9 ± 1.1% pre- to 7.1 ± 1.1% post-KNO3). Despite this, there was a significant elevation of plasma [nitrite] (0.4 ± 0.1 μM pre- to 0.7 ± 0.2 μM post-KNO3, p < 0.001). In addition these changes in [nitrite] were associated with a decrease in systolic BP (116.9 ± 3.8 mm Hg pre- vs. 112.1 ± 3.4 mm Hg post-KNO3, p < 0.05) and aPWV (6.5 ± 0.1 m/s pre- to 6.2 ± 0.1 post-KNO3, p < 0.01). In contrast KCl capsules had no effect on any of the parameters measured. These findings demonstrate that although inorganic nitrate ingestion does not alter endothelial function per se, it does appear to improve blood flow, in combination with a reduction in blood pressure. It is likely that these changes are due to the intra-vascular production of NO. PMID:22285857

Letter to editor: Blood pressure, hypertension and lead exposure.

PubMed

Yang, Wen-Yi; Staessen, Jan A

2018-02-19

A significant association of office diastolic blood pressure with low-level blood lead exposure was reported in a Brazilian adult population. However, caution should be taken to interpret these results. The multivariable-adjusted association with blood pressure was positive for diastolic blood pressure, but inverse for systolic blood pressure. The association sizes were infinitesimal without clinical relevance. The outcome measures, i.e. blood pressure and the prevalence of hypertension were analysed across categories of the blood lead distribution - not in relation to blood lead as continuous variable. Blood pressure was the average of two oscillometric office readings, whereas ambulatory monitoring is the state-of-the-art.

Influence of non-dipping pattern of blood pressure in gestational hypertension on maternal cardiac function, hemodynamics and intrauterine growth restriction.

PubMed

Ilic, A; Ilic, D J; Tadic, S; Stefanovic, M; Stojsic-Milosavljevic, A; Pavlovic, K; Redzek, A; Velicki, L

2017-10-01

An association between gestational hypertension (GH) and changes of maternal cardiac function was previously reported. The study assessed the effect of non-dipping pattern of blood pressure (BP) in GH on haemodynamic function and intrauterine growth restriction (IUGR). This study included 126 women (91 with GH and 35 normotensive controls). Based on the BP values measured by ambulatory blood pressure monitoring (ABPM), all hypertensive women were classified in dipper (46 women) or in non-dipper group (45 women). All participants underwent echocardiography and ABPM during the third trimester. Participants with GH and non-dipping pattern had significantly lower velocity of longitudinal systolic function (s') (p<0.0005), and cardiac output index (COi) compared to dippers (p<0.0005) and controls (p=0.002). Diastolic velocities at the mitral valve annulus were also lower in non-dippers e's (non-dippers vs dippers p=0.023; non-dippers vs controls p<0.0005) and e'l (non-dippers vs dippers p=0.048; non-dippers vs controls p<0.0005). There were significant differences in the index of the left ventricle filling pressure E/e' and myocardial mass index between women with GH and controls, but with no significant difference among dippers and non-dippers. Total vascular resistance was increased in non-dipping group compared to normotensives and dippers (p<0.0005). Multivariate regression analysis revealed that the peak night-time diastolic BP, left ventricular mass index and CO index were identified as independent predictors of IUGR. Changes in maternal hemodynamics, as well as IUGR, are strongly related to the non-dipping pattern of BP. Copyright © 2017 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.

Hormones and the hippocampus.

PubMed

Lathe, R

2001-05-01

Hippocampal lesions produce memory deficits, but the exact function of the hippocampus remains obscure. Evidence is presented that its role in memory may be ancillary to physiological regulation. Molecular studies demonstrate that the hippocampus is a primary target for ligands that reflect body physiology, including ion balance and blood pressure, immunity, pain, reproductive status, satiety and stress. Hippocampal receptors are functional, probably accessible to their ligands, and mediate physiological and cognitive changes. This argues that an early role of the hippocampus may have been in sensing soluble molecules (termed here 'enteroception') in blood and cerebrospinal fluid, perhaps reflecting a common evolutionary origin with the olfactory system ('exteroception'). Functionally, hippocampal enteroception may reflect feedback control; evidence is reviewed that the hippocampus modulates body physiology, including the activity of the hypothalamus-pituitary-adrenal axis, blood pressure, immunity, and reproductive function. It is suggested that the hippocampus operates, in parallel with the amygdala, to modulate body physiology in response to cognitive stimuli. Hippocampal outputs are predominantly inhibitory on downstream neuroendocrine activity; increased synaptic efficacy in the hippocampus (e.g. long-term potentiation) could facilitate throughput inhibition. This may have implications for the role of the hippocampus and long-term potentiation in memory.

Blood pressure

MedlinePlus

Normal blood pressure is important for proper blood flow to the body's organs and tissues. The force of the blood on the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart ...

Intensive versus conventional blood pressure monitoring in a general practice population. The Blood Pressure Reduction in Danish General Practice trial: a randomized controlled parallel group trial.

PubMed

Klarskov, Pia; Bang, Lia E; Schultz-Larsen, Peter; Gregers Petersen, Hans; Benee Olsen, David; Berg, Ronan M G; Abrahamsen, Henrik; Wiinberg, Niels

2018-01-17

To compare the effect of a conventional to an intensive blood pressure monitoring regimen on blood pressure in hypertensive patients in the general practice setting. Randomized controlled parallel group trial with 12-month follow-up. One hundred and ten general practices in all regions of Denmark. One thousand forty-eight patients with essential hypertension. Conventional blood pressure monitoring ('usual group') continued usual ad hoc blood pressure monitoring by office blood pressure measurements, while intensive blood pressure monitoring ('intensive group') supplemented this with frequent home blood pressure monitoring and 24-hour ambulatory blood pressure monitoring. Mean day- and night-time systolic and diastolic 24-hour ambulatory blood pressure. Change in systolic and diastolic office blood pressure and change in cardiovascular risk profile. Of the patients, 515 (49%) were allocated to the usual group, and 533 (51%) to the intensive group. The reductions in day- and night-time 24-hour ambulatory blood pressure were similar (usual group: 4.6 ± 13.5/2.8 ± 82 mmHg; intensive group: 5.6 ± 13.0/3.5 ± 8.2 mmHg; P = 0.27/P = 0.20). Cardiovascular risk scores were reduced in both groups at follow-up, but more so in the intensive than in the usual group (P = 0.02). An intensive blood pressure monitoring strategy led to a similar blood pressure reduction to conventional monitoring. However, the intensive strategy appeared to improve patients' cardiovascular risk profile through other effects than a reduction of blood pressure. Clinical Trials NCT00244660. © The Author 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Relationship of central and peripheral blood pressure to left ventricular mass in hypertensive patients.

PubMed

Pérez-Lahiguera, Francisco J; Rodilla, Enrique; Costa, Jose A; Gonzalez, Carmen; Martín, Joaquin; Pascual, Jose M

2012-12-01

The purpose of the present study was to assess the relationship of central and peripheral blood pressure to left ventricular mass. Cross-sectional study that included 392 never treated hypertensive individuals. Measurement of office, 24-h ambulatory, and central blood pressure (obtained using applanation tonometry) and determination of left ventricular mass by echocardiography were performed in all patients. In a multiple regression analysis, with adjustment for age, gender and metabolic syndrome, 24-h blood pressure was more closely related to ventricular mass than the respective office and central blood pressures. Systolic blood pressures always exhibited a higher correlation than diastolic blood pressures in all 3 determinations. The correlation between left ventricular mass index and 24-h systolic blood pressure was higher than that of office (P<.002) or central systolic blood pressures (P<.002). Changes in 24-h systolic blood pressure caused the greatest variations in left ventricular mass index (P<.001). In our population of untreated middle-aged hypertensive patients, left ventricular mass index is more closely related to 24-h ambulatory blood pressure than to office or central blood pressure. Central blood pressure does not enable us to better identify patients with left ventricular hypertrophy. Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Concord grape juice, cognitive function, and driving performance: a 12-wk, placebo-controlled, randomized crossover trial in mothers of preteen children.

PubMed

Lamport, Daniel J; Lawton, Clare L; Merat, Natasha; Jamson, Hamish; Myrissa, Kyriaki; Hofman, Denise; Chadwick, Helen K; Quadt, Frits; Wightman, JoLynne D; Dye, Louise

2016-03-01

Daily consumption of Concord grape juice (CGJ) over 3-4 mo has been shown to improve memory function in adults with mild cognitive impairment and reduce blood pressure in hypertensive adults. These benefits likely result from the high concentration of polyphenols in CGJ. Increased stress can impair cognitive function and elevate blood pressure. Thus, we examined the potential beneficial effect of CGJ in individuals with somewhat stressful and demanding lifestyles. We sought to examine the effects of the daily consumption of CGJ for 12 wk on cognitive function, driving performance, and blood pressure in healthy, middle-aged working mothers. Twenty-five healthy mothers (aged 40-50 y) of preteen children who were employed for ≥30 h/wk consumed 12 ounces (355 mL) of either CGJ (containing 777 mg total polyphenols) or an energy-, taste-, and appearance-matched placebo daily for 12 wk according to a randomized crossover design with a 4-wk washout. Verbal and spatial memory, executive function, attention, blood pressure, and mood were assessed at baseline and at 6 and 12 wk. Immediately after the cognitive battery, a subsample of 17 women completed a driving performance assessment at the University of Leeds Driving Simulator. The 25-min driving task required participants to match the speed and direction of a lead vehicle. Significant improvements in immediate spatial memory and driving performance were observed after CGJ relative to placebo. There was evidence of an enduring effect of CGJ such that participants who received CGJ in arm 1 maintained better performance in the placebo arm. Cognitive benefits associated with the long-term consumption of flavonoid-rich grape juice are not exclusive to adults with mild cognitive impairment. Moreover, these cognitive benefits are apparent in complex everyday tasks such as driving. Effects may persist beyond the cessation of flavonoid consumption, and future studies should carefully consider the length of washout within crossover designs. This trial was registered at clinicaltrials.gov as NCT01411631. © 2016 American Society for Nutrition.

Investigation of the blood behaviour and vascular diseases by using mathematical physic principles

NASA Astrophysics Data System (ADS)

Yardimci, Ahmet; Simsek, Buket

2017-07-01

In this paper we prepare a short survey for using of mathematical physic principles in blood flow and vascular diseases researches. The study of the behavior of blood flow in the blood vessels provides understanding on connection between flow and the development of dieseases such as atherosclerosis, thrombosis, aneurysms etc. and how the flow dynamics is changed under these conditions. Blood flow phenomena are often too complex that it would be possible to describe them entirely analytically, although simple models, such as Poiseuille model, can still provide some insight into blood flow. Blood is not an "ideal fluid" and energy is lost as flowing blood overcomes resistance. Resistance to blood flow is a function of viscosity, vessel radius, and vessel length. So, mathematical Physic principles are useful tools for blood flow research studies. Blood flow is a function of pressure gradient and resistance and resistance to flow can be estimates using Poiseuille's law. Reynold's number can be used to determine whether flow is laminar or turbulent.

Modified Beer-Lambert law for blood flow.

PubMed

Baker, Wesley B; Parthasarathy, Ashwin B; Busch, David R; Mesquita, Rickson C; Greenberg, Joel H; Yodh, A G

2014-11-01

We develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues.

[Blood pressure measurement].

PubMed

Bang, Lia Evi; Wiinberg, Niels

2009-06-08

Blood pressure measurement should follow recommended procedures, otherwise incorrect diagnoses will follow resulting in incorrect treatment and cardiovascular events. The standard for clinical blood pressure measurement is the auscultatory method, but mercury sphygmomanometers can still be used. Blood pressure measurement at home using 24-hour or home blood pressure has documented a better reproducibility and predicts cardiovascular event more precisely than clinic blood pressure. 24-hour measurement or home blood pressure measurement should be performed in patients with suspected hypertension without hypertensive organ damage to reveal white-coat hypertension.

A common humoral background of intraocular and arterial blood pressure dysregulation.

PubMed

Skrzypecki, Janusz; Grabska-Liberek, Iwona; Przybek, Joanna; Ufnal, Marcin

2018-03-01

It has been postulated that intraocular pressure, an important glaucoma risk factor, correlates positively with arterial blood pressure (blood pressure). However, results of experimental and clinical studies are often contradictory. It is hypothesized that, in some hypertensive patients, disturbances in intraocular pressure regulation may depend on biological effects of blood borne hormones underlying a particular type of hypertension, rather than on blood pressure level itself. This review compares the effects of hormones on blood pressure and intraocular pressure, in order to identify a hormonal profile of hypertensive patients with an increased risk of intraocular pressure surge. The PUBMED database was searched to identify pre-clinical and clinical studies investigating the role of angiotensin II, vasopressin, adrenaline, noradrenaline, prostaglandins, and gaseous transmitters in the regulation of blood pressure and intraocular pressure. Studies included in the review suggest that intraocular and blood pressures often follow a different pattern of response to the same hormone. For example, vasopressin increases blood pressure, but decreases intraocular pressure. In contrast, high level of nitric oxide decreases blood pressure, but increases intraocular pressure. Arterial hypertension is associated with altered levels of blood borne hormones. Contradicting results of studies on the relationship between arterial hypertension and intraocular pressure might be partially explained by diverse effects of hormones on arterial and intraocular pressures. Further studies are needed to evaluate if hormonal profiling may help to identify glaucoma-prone patients.

Ambulatory versus home versus clinic blood pressure: the association with subclinical cerebrovascular diseases: the Ohasama Study.

PubMed

Hara, Azusa; Tanaka, Kazushi; Ohkubo, Takayoshi; Kondo, Takeo; Kikuya, Masahiro; Metoki, Hirohito; Hashimoto, Takanao; Satoh, Michihiro; Inoue, Ryusuke; Asayama, Kei; Obara, Taku; Hirose, Takuo; Izumi, Shin-Ichi; Satoh, Hiroshi; Imai, Yutaka

2012-01-01

The usefulness of ambulatory, home, and casual/clinic blood pressure measurements to predict subclinical cerebrovascular diseases (silent cerebrovascular lesions and carotid atherosclerosis) was compared in a general population. Data on ambulatory, home, and casual/clinic blood pressures and brain MRI to detect silent cerebrovascular lesions were obtained in 1007 subjects aged ≥55 years in a general population of Ohasama, Japan. Of the 1007 subjects, 583 underwent evaluation of the extent of carotid atherosclerosis. Twenty-four-hour, daytime, and nighttime ambulatory and home blood pressure levels were closely associated with the risk of silent cerebrovascular lesions and carotid atherosclerosis (all P<0.05). When home and one of the ambulatory blood pressure values were simultaneously included in the same regression model, each of the ambulatory blood pressure values remained a significant predictor of silent cerebrovascular lesions, whereas home blood pressure lost its predictive value. Of the ambulatory blood pressure values, nighttime blood pressure was the strongest predictor of silent cerebrovascular lesions. The home blood pressure value was more closely associated with the risk of carotid atherosclerosis than any of the ambulatory blood pressure values when home and one of the ambulatory blood pressure values were simultaneously included in the same regression model. The casual/clinic blood pressure value had no significant association with the risk of subclinical cerebrovascular diseases. Although the clinical indications for ambulatory blood pressure monitoring and home blood pressure measurements may overlap, the clinical significance of each method for predicting target organ damage may differ for different target organs.

Endocannabinoids Acting at Cannabinoid-1 Receptors Regulate Cardiovascular Function in Hypertension

PubMed Central

Bátkai, Sándor; Pacher, Pál; Osei-Hyiaman, Douglas; Radaeva, Svetlana; Liu, Jie; Harvey-White, Judith; Offertáler, László; Mackie, Ken; Audrey Rudd, M.; Bukoski, Richard D.; Kunos, George

2009-01-01

Background Endocannabinoids are novel lipid mediators with hypotensive and cardiodepressor activity. Here, we examined the possible role of the endocannabinergic system in cardiovascular regulation in hypertension. Methods and Results In spontaneously hypertensive rats (SHR), cannabinoid-1 receptor (CB1) antagonists increase blood pressure and left ventricular contractile performance. Conversely, preventing the degradation of the endocannabinoid anandamide by an inhibitor of fatty acid amidohydrolase reduces blood pressure, cardiac contractility, and vascular resistance to levels in normotensive rats, and these effects are prevented by CB1 antagonists. Similar changes are observed in 2 additional models of hypertension, whereas in normotensive control rats, the same parameters remain unaffected by any of these treatments. CB1 agonists lower blood pressure much more in SHR than in normotensive Wistar-Kyoto rats, and the expression of CB1 is increased in heart and aortic endothelium of SHR compared with Wistar-Kyoto rats. Conclusions We conclude that endocannabinoids tonically suppress cardiac contractility in hypertension and that enhancing the CB1-mediated cardiodepressor and vasodilator effects of endogenous anandamide by blocking its hydrolysis can normalize blood pressure. Targeting the endocannabinoid system offers novel therapeutic strategies in the treatment of hypertension. PMID:15451779

Sleep Complaints Predict Increases in Resting Blood Pressure Following Marital Separation

PubMed Central

Krietsch, Kendra N.; Mason, Ashley E.; Sbarra, David A.

2015-01-01

Objective Although marital separation and divorce are associated with many negative health outcomes, few studies examine the psychophysiological mechanisms that may give rise to these outcomes. This study examined changes in resting blood pressure (BP) as a function of sleep complaints in recently divorced adults. Method Recently separated adults (n = 138; 38 men) completed a self-report measure of sleep complaints and a resting blood pressure (BP) assessment in the laboratory at three occasions across 7.5 months. Results Multilevel analyses revealed that although sleep complaints were not associated with concurrent BP, sleep complaints predicted significant increases in both systolic and diastolic BP at the subsequent laboratory visit. In addition, time since the separation from an ex-partner moderated the association between sleep complaints at baseline and resting systolic blood pressure (SBP) 3 months later. People who reported high sleep complaints 10 weeks or more after their separation demonstrated greater increases in SBP. Conclusions In recently separated adults, greater sleep complaints may index increased risk for future increases in BP. This work helps pinpoint one potential mechanistic pathway linking marital separation with an important, health-relevant biological outcome. PMID:25020156

Effect of ACE-inhibition on coronary microvascular function and symptoms in normotensive women with microvascular angina: A randomized placebo-controlled trial

PubMed Central

Suhrs, Elena; Raft, Kristoffer Flintholm; Høst, Nis; Prescott, Eva

2018-01-01

Objective Studies have suggested a beneficial effect of angiotensin-converting enzyme (ACE) inhibition. To explore whether the ACE inhibitor ramipril has a direct effect on the microvasculature beyond the blood pressure (BP) lowering effect, we investigated whether ramipril improved coronary microvascular function in normotensive women with coronary microvascular dysfunction (CMD). Methods We included 63 normotensive women with angina, no epicardial stenosis>50% and CMD defined as a coronary flow velocity reserve (CFVR)<2.2 assessed by adenosine stress-echocardiography in a randomized double-blinded, superiority trial with 1:1 allocation to placebo or ramipril (maximum dose 10 mg depending on blood pressure) for 24±6 weeks. Primary outcome was CFVR. Secondary outcomes were left ventricular systolic and diastolic function and symptoms evaluated by Seattle Angina Questionnaire (clinicaltrials.gov, NCT02525081). Results Follow-up was available on 55 patients. BP remained unchanged during treatment in both groups. CFVR improved in both the ramipril (p = 0.004) and placebo group (p = 0.026) with no difference between groups (p = 0.63). Symptoms improved in both groups with no significant between-group differences. No changes were detected in parameters of systolic and diastolic function. No serious adverse reactions were reported. Conclusions In normotensive women with angina and CMD, treatment with ramipril had no significant effect on CFVR or symptoms compared with placebo. The effect of ACE inhibition previously reported may be mediated by blood pressure reduction. PMID:29883497

Maintained functionality of an implantable radiotelemetric blood pressure and heart rate sensor after magnetic resonance imaging in rats.

PubMed

Nölte, I; Gorbey, S; Boll, H; Figueiredo, G; Groden, C; Lemmer, B; Brockmann, M A

2011-12-01

Radiotelemetric sensors for in vivo assessment of blood pressure and heart rate are widely used in animal research. MRI with implanted sensors is regarded as contraindicated as transmitter malfunction and injury of the animal may be caused. Moreover, artefacts are expected to compromise image evaluation. In vitro, the function of a radiotelemetric sensor (TA11PA-C10, Data Sciences International) after exposure to MRI up to 9.4 T was assessed. The magnetic force of the electromagnetic field on the sensor as well as radiofrequency (RF)-induced sensor heating was analysed. Finally, MRI with an implanted sensor was performed in a rat. Imaging artefacts were analysed at 3.0 and 9.4 T ex vivo and in vivo. Transmitted 24 h blood pressure and heart rate were compared before and after MRI to verify the integrity of the telemetric sensor. The function of the sensor was not altered by MRI up to 9.4 T. The maximum force exerted on the sensor was 273 ± 50 mN. RF-induced heating was ruled out. Artefacts impeded the assessment of the abdomen and thorax in a dead rat, but not of the head and neck. MRI with implanted radiotelemetric sensors is feasible in principal. The tested sensor maintains functionality up to 9.4 T. Artefacts hampered abdominal and throacic imaging in rats, while assessment of the head and neck is possible.

Blood Pressure Variability and Cognitive Function Among Older African Americans: Introducing a New Blood Pressure Variability Measure.

PubMed

Tsang, Siny; Sperling, Scott A; Park, Moon Ho; Helenius, Ira M; Williams, Ishan C; Manning, Carol

2017-09-01

Although blood pressure (BP) variability has been reported to be associated with cognitive impairment, whether this relationship affects African Americans has been unclear. We sought correlations between systolic and diastolic BP variability and cognitive function in community-dwelling older African Americans, and introduced a new BP variability measure that can be applied to BP data collected in clinical practice. We assessed cognitive function in 94 cognitively normal older African Americans using the Mini-Mental State Examination (MMSE) and the Computer Assessment of Mild Cognitive Impairment (CAMCI). We used BP measurements taken at the patients' three most recent primary care clinic visits to generate three traditional BP variability indices, range, standard deviation, and coefficient of variation, plus a new index, random slope, which accounts for unequal BP measurement intervals within and across patients. MMSE scores did not correlate with any of the BP variability indices. Patients with greater diastolic BP variability were less accurate on the CAMCI verbal memory and incidental memory tasks. Results were similar across the four BP variability indices. In a sample of cognitively intact older African American adults, BP variability did not correlate with global cognitive function, as measured by the MMSE. However, higher diastolic BP variability correlated with poorer verbal and incidental memory. By accounting for differences in BP measurement intervals, our new BP variability index may help alert primary care physicians to patients at particular risk for cognitive decline.

School burnout: increased sympathetic vasomotor tone and attenuated ambulatory diurnal blood pressure variability in young adult women.

PubMed

May, Ross W; Sanchez-Gonzalez, Marcos A; Fincham, Frank D

2015-01-01

Two studies examined autonomic and cardiovascular functioning that may link school burnout to cardiovascular risk factors in young healthy adult females. Study 1 (N = 136) investigated whether school burnout was related to resting values of blood pressure (BP) and blood pressure variability (BPV) through laboratory beat-to-beat BP assessment. Study 2 (N = 94) examined the link between school burnout and diurnal BPV through ambulatory BP monitoring. Controlling for anxiety and depressive symptomatology, school burnout demonstrated strong positive relationships with indices of cardiac sympathovagal tone, sympathetic vasomotor tone, inefficient myocardial oxygen consumption, increased 24-h ambulatory heart rate and BP, blunted BP diurnal variability, and increased arterial stiffness. These studies establish cardiovascular biomarkers of school burnout and suggest that even in a seemingly healthy sample school burnout may predispose females to increased cardiovascular risk. Several future lines of research are outlined.

Tumor necrosis factor-α: regulation of renal function and blood pressure

PubMed Central

Garvin, Jeffrey L.

2013-01-01

Tumor necrosis factor-α (TNF-α) is a pleiotropic cytokine that becomes elevated in chronic inflammatory states such as hypertension and diabetes and has been found to mediate both increases and decreases in blood pressure. High levels of TNF-α decrease blood pressure, whereas moderate increases in TNF-α have been associated with increased NaCl retention and hypertension. The explanation for these disparate effects is not clear but could simply be due to different concentrations of TNF-α within the kidney, the physiological status of the subject, or the type of stimulus initiating the inflammatory response. TNF-α alters renal hemodynamics and nephron transport, affecting both activity and expression of transporters. It also mediates organ damage by stimulating immune cell infiltration and cell death. Here we will summarize the available findings and attempt to provide plausible explanations for such discrepancies. PMID:23515717

CHRONOBIOLOGY OF HIGH BLOOD PRESSURE

PubMed Central

Cornélissen, G.; Halberg, F.; Bakken, E. E.; Wang, Z.; Tarquini, R.; Perfetto, F.; Laffi, G.; Maggioni, C.; Kumagai, Y.; Homolka, P.; Havelková, A.; Dušek, J.; Svačinová, H.; Siegelová, J.; Fišer, B.

2008-01-01

BIOCOS, the project aimed at studying BIOlogical systems in their COSmos, has obtained a great deal of expertise in the fields of blood pressure (BP) and heart rate (HR) monitoring and of marker rhythmometry for the purposes of screening, diagnosis, treatment, and prognosis. Prolonging the monitoring reduces the uncertainty in the estimation of circadian parameters; the current recommendation of BIOCOS requires monitoring for at least 7 days. The BIOCOS approach consists of a parametric and a non-parametric analysis of the data, in which the results from the individual subject are being compared with gender- and age-specified reference values in health. Chronobiological designs can offer important new information regarding the optimization of treatment by timing its administration as a function of circadian and other rhythms. New technological developments are needed to close the loop between the monitoring of blood pressure and the administration of antihypertensive drugs. PMID:19122770

Inter-arm blood pressure differences in pregnant women.

PubMed

Poon, L C Y; Kametas, N; Strobl, I; Pachoumi, C; Nicolaides, K H

2008-08-01

To determine the prevalence of blood pressure inter-arm difference (IAD) in early pregnancy and to investigate its possible association with maternal characteristics. A cross-sectional observational study. Routine antenatal visit in a university hospital. A total of 5435 pregnant women at 11-14 weeks of gestation. Blood pressure was taken from both arms simultaneously with a validated automated device. The presence of inter-arm blood pressure difference of 10 mmHg or more. The IAD in systolic and diastolic blood pressure was 10 mmHg or more in 8.3 and 2.3% of the women, respectively. Systolic IAD was found to be significantly related to systolic blood pressure and pulse pressure, and diastolic IAD was found to be significantly related to maternal age, diastolic blood pressure and pulse pressure. The systolic and diastolic IAD were higher in the hypertensive group compared with the normotensive group and absolute IAD increased with increasing blood pressure. About 31.0 and 23.9% of cases of hypertension would have been underreported if the left arm and the right arm were used, respectively, in measuring the blood pressure. There is a blood pressure IAD in a significant proportion of the pregnant population, and its prevalence increases with increasing blood pressure. By measuring blood pressure only on one arm, there is a one in three chance of underreporting hypertension. Therefore, it would be prudent that during the booking visit blood pressure should be taken in both arms and thus provide guidance for subsequent blood pressure measurements during the course of pregnancy.

Central blood pressure and chronic kidney disease

PubMed Central

Ohno, Yoichi; Kanno, Yoshihiko; Takenaka, Tsuneo

2016-01-01

In this review, we focused on the relationship between central blood pressure and chronic kidney diseases (CKD). Wave reflection is a major mechanism that determines central blood pressure in patients with CKD. Recent medical technology advances have enabled non-invasive central blood pressure measurements. Clinical trials have demonstrated that compared with brachial blood pressure, central blood pressure is a stronger risk factor for cardiovascular (CV) and renal diseases. CKD is characterized by a diminished renal autoregulatory ability, an augmented direct transmission of systemic blood pressure to glomeruli, and an increase in proteinuria. Any elevation in central blood pressure accelerates CKD progression. In the kidney, interstitial inflammation induces oxidative stress to handle proteinuria. Oxidative stress facilitates atherogenesis, increases arterial stiffness and central blood pressure, and worsens the CV prognosis in patients with CKD. A vicious cycle exists between CKD and central blood pressure. To stop this cycle, vasodilator antihypertensive drugs and statins can reduce central blood pressure and oxidative stress. Even in early-stage CKD, mineral and bone disorders (MBD) may develop. MBD promotes oxidative stress, arteriosclerosis, and elevated central blood pressure in patients with CKD. Early intervention or prevention seems necessary to maintain vascular health in patients with CKD. PMID:26788468

Methodology and technology for peripheral and central blood pressure and blood pressure variability measurement: current status and future directions - Position statement of the European Society of Hypertension Working Group on blood pressure monitoring and cardiovascular variability.

PubMed

Stergiou, George S; Parati, Gianfranco; Vlachopoulos, Charalambos; Achimastos, Apostolos; Andreadis, Emanouel; Asmar, Roland; Avolio, Alberto; Benetos, Athanase; Bilo, Grzegorz; Boubouchairopoulou, Nadia; Boutouyrie, Pierre; Castiglioni, Paolo; de la Sierra, Alejandro; Dolan, Eamon; Head, Geoffrey; Imai, Yutaka; Kario, Kazuomi; Kollias, Anastasios; Kotsis, Vasilis; Manios, Efstathios; McManus, Richard; Mengden, Thomas; Mihailidou, Anastasia; Myers, Martin; Niiranen, Teemu; Ochoa, Juan Eugenio; Ohkubo, Takayoshi; Omboni, Stefano; Padfield, Paul; Palatini, Paolo; Papaioannou, Theodore; Protogerou, Athanasios; Redon, Josep; Verdecchia, Paolo; Wang, Jiguang; Zanchetti, Alberto; Mancia, Giuseppe; O'Brien, Eoin

2016-09-01

Office blood pressure measurement has been the basis for hypertension evaluation for almost a century. However, the evaluation of blood pressure out of the office using ambulatory or self-home monitoring is now strongly recommended for the accurate diagnosis in many, if not all, cases with suspected hypertension. Moreover, there is evidence that the variability of blood pressure might offer prognostic information that is independent of the average blood pressure level. Recently, advancement in technology has provided noninvasive evaluation of central (aortic) blood pressure, which might have attributes that are additive to the conventional brachial blood pressure measurement. This position statement, developed by international experts, deals with key research and practical issues in regard to peripheral blood pressure measurement (office, home, and ambulatory), blood pressure variability, and central blood pressure measurement. The objective is to present current achievements, identify gaps in knowledge and issues concerning clinical application, and present relevant research questions and directions to investigators and manufacturers for future research and development (primary goal).

Impact of Iodinated Contrast on Renal Function and Hemodynamics in Rats with Chronic Hyperglycemia and Chronic Kidney Disease

PubMed Central

Fernandes, Sheila Marques; Martins, Daniel Malisani; da Fonseca, Cassiane Dezoti; Watanabe, Mirian; Vattimo, Maria de Fátima Fernandes

2016-01-01

Iodinated contrast (IC) is clinically used in diagnostic and interventional procedures, but its use can result in contrast-induced acute kidney injury (CI-AKI). Chronic kidney disease (CKD) and chronic hyperglycemia (CH) are important predisposing factors to CI-AKI. The aim of this study was to investigate the impact of iodinated contrast on the renal function and hemodynamics in rats with chronic hyperglycemia and chronic kidney disease. A total of 30 rats were divided into six groups; Sham: control of chronic renal disease; Citrate: control of chronic hyperglycemia (CH); Nx5/6: rats with 5/6 nephrectomy; Chronic Hyperglycemia: rats receiving Streptozotocin 65 mg/kg; Nx5/6 + IC: rats Nx5/6 received 6 mL/kg of IC; CH + IC: Chronic hyperglycemia rats receiving 6 mL/kg of IC. Renal function (inulin clearance; urinary neutrophil gelatinase-associated lipocalin, NGAL) and hemodynamics (arterial blood pressure; renal blood flow; renal vascular resistance) were evaluated. Iodinated contrast significantly increased urinary NGAL and reduced inulin clearance, while the hemodynamics parameters showed changes in arterial blood pressure, renal blood flow, and renal vascular resistance in both CKD and CH groups. The results suggest that the iodinated contrast in risk factors models has important impact on renal function and hemodynamics. NGAL was confirmed to play a role of highlight in diagnosis of CI-AKI. PMID:27034930

Cardiovascular reflexes during rest and exercise modified by gravitational stresses

NASA Astrophysics Data System (ADS)

Bonde-petersen, Flemming

The hypotheses tested were whether variations in central venous pressure via the low pressure baroreceptors would take over or modify the arterial baroreceptor function, and further to which extent local and "whole body" hydrostatic stresses influence blood flow distribution. We investigated total forearm and skin blood flow (venous occlusion plethysmography and 133-Xe clearance) and cardiac output (rebreathing method) among other parameters. Hypo-and hypergravitational stresses were simulated by LBNP, LBPP, water immersion and lowering of the arm. The changes in flow distribution in the arm were ascribed to arterial baroreceptor function and not to low pressure baroreceptor activity. The enhancement of venous return during water immersion increased exercise tolerance during heat stress presumably due both to increased stroke volume and decreased venous pooling. The response to sustained handgrip exercise during LBNP and LBPP was not different from control measurements and the effects explained by arterial baroreceptor function. Application of exercise and local hydrostatic stresses in combination with gravitational stresses represent an interesting model for further study of the mechanisms behind the distribution of cardiac output to the peripheral organs.

Functional adaptations of the coronary microcirculation to anaemia in fetal sheep.

PubMed

Jonker, Sonnet S; Davis, Lowell; Soman, Divya; Belcik, J Todd; Davidson, Brian P; Atkinson, Tamara M; Wilburn, Adrienne; Louey, Samantha; Giraud, George D; Lindner, Jonathan R

2016-11-01

In fetuses, chronic anaemia stimulates cardiac growth; simultaneously, blood flow to the heart muscle itself is increased, and reserve blood flow capacity of the coronary vascular bed is preserved. Here we examined functional adaptations of the capillaries and small blood vessels responsible for delivering oxygen to the anaemic fetal heart muscle using contrast-enhanced echocardiography. We demonstrate that coronary microvascular flux rate doubled in anaemic fetuses compared to control fetuses, both at rest and during maximal flow, suggesting reduced microvascular resistance consistent with capillary widening. Cardiac fractional microvascular blood volume was not greater in anaemic fetuses, suggesting that growth of new microvascular vessels does not contribute to the increased flow per volume of myocardium. These unusual changes in microvascular function during anaemia may indicate novel adaptive strategies in the fetal heart. Fetal anaemia causes cardiac adaptations that have immediate and life-long repercussions on heart function and health. It is known that resting and maximal coronary conductance both increase during chronic fetal anaemia, but the coronary microvascular changes responsible for the adaptive response are unknown. Until recently, technical limitations have prevented quantifying functional capillary-level adaptations in the in vivo fetal heart. Our objective was to characterise functional microvascular adaptations in chronically anaemic fetal sheep. Chronically instrumented fetuses were randomized to a control group (n = 11) or were made anaemic by isovolumetric haemorrhage (n = 12) for 1 week prior to myocardial contrast echocardiography at 85% of gestation. Anaemia augmented cardiac mass by 23% without changing body weight. In anaemic fetuses, microvascular blood flow per volume of myocardium was twice that of control fetuses at rest, during vasodilatory hyperaemia, and during hyperaemia plus increased aortic pressure. The elevated blood flow was attributable almost entirely to an increase in microvascular blood flux rate whereas microvascular blood volumes were not different between groups at baseline, during hyperaemia, or with hyperaemia plus increased aortic pressure. Increased coronary microvascular flux rate in response to chronic fetal anaemia is consistent with expected reductions in capillary resistance from capillary diameter widening detected in earlier histological studies. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Grape seed proanthocyanidin extract alleviates ouabain-induced vascular remodeling through regulation of endothelial function.

PubMed

Liu, Xiangju; Qiu, Jie; Zhao, Shaohua; You, Beian; Ji, Xiang; Wang, Yan; Cui, Xiaopei; Wang, Qian; Gao, Haiqing

2012-11-01

Recent studies indicate that chronic ouabain treatment leads to hypertension and hypertensive vascular remodeling. Grape seed proanthocyanidin extract (GSPE) has been reported to be effective in treating arteriosclerosis, while little is known about its effect on systolic blood pressure and vascular remodeling. In this study, the effects of GSPE on systolic blood pressure and vascular remodeling were analyzed by treating ouabain-induced hypertensive rats with GSPE (250 mg/kg·d). The expression of nitric oxide (NO) and endothelin-1 (ET-1) in thoracic aorta was examined by ELISA; the mRNA and protein levels of TGF-β1 were detected using real-time PCR and western blotting, respectively. The results showed that the systolic blood pressure was significantly decreased following treatment with GSPE, with blocked vascular remodeling. The ET-1 content was reduced while NO production was increased in the GSPE group, which showed improved vascular endothelial function. Moreover, GSPE also reduced TGF-β1 expression in the thoracic aorta, which is a determinant in vascular remodeling. In conclusion, GSPE antagonized ouabain-induced hypertension and vascular remodeling and is recommended as a potential anti-hypertensive agent for patients with hypertensive vascular diseases.

Physical Exercise and Patients with Chronic Renal Failure: A Meta-Analysis.

PubMed

Qiu, Zhenzhen; Zheng, Kai; Zhang, Haoxiang; Feng, Ji; Wang, Lizhi; Zhou, Hao

2017-01-01

Chronic renal failure is a severe clinical problem which has some significant socioeconomic impact worldwide and hemodialysis is an important way to maintain patients' health state, but it seems difficult to get better in short time. Considering these, the aim in our research is to update and evaluate the effects of exercise on the health of patients with chronic renal failure. The databases were used to search for the relevant studies in English or Chinese. And the association between physical exercise and health state of patients with chronic renal failure has been investigated. Random-effect model was used to compare the physical function and capacity in exercise and control groups. Exercise is helpful in ameliorating the situation of blood pressure in patients with renal failure and significantly reduces VO 2 in patients with renal failure. The results of subgroup analyses show that, in the age >50, physical activity can significantly reduce blood pressure in patients with renal failure. The activity program containing warm-up, strength, and aerobic exercises has benefits in blood pressure among sick people and improves their maximal oxygen consumption level. These can help patients in physical function and aerobic capacity and may give them further benefits.

Physical Exercise and Patients with Chronic Renal Failure: A Meta-Analysis

PubMed Central

Qiu, Zhenzhen; Zheng, Kai; Zhang, Haoxiang; Feng, Ji; Wang, Lizhi

2017-01-01

Chronic renal failure is a severe clinical problem which has some significant socioeconomic impact worldwide and hemodialysis is an important way to maintain patients' health state, but it seems difficult to get better in short time. Considering these, the aim in our research is to update and evaluate the effects of exercise on the health of patients with chronic renal failure. The databases were used to search for the relevant studies in English or Chinese. And the association between physical exercise and health state of patients with chronic renal failure has been investigated. Random-effect model was used to compare the physical function and capacity in exercise and control groups. Exercise is helpful in ameliorating the situation of blood pressure in patients with renal failure and significantly reduces VO2 in patients with renal failure. The results of subgroup analyses show that, in the age >50, physical activity can significantly reduce blood pressure in patients with renal failure. The activity program containing warm-up, strength, and aerobic exercises has benefits in blood pressure among sick people and improves their maximal oxygen consumption level. These can help patients in physical function and aerobic capacity and may give them further benefits. PMID:28316986

Modeling of Kidney Hemodynamics: Probability-Based Topology of an Arterial Network.

PubMed

Postnov, Dmitry D; Marsh, Donald J; Postnov, Dmitry E; Braunstein, Thomas H; Holstein-Rathlou, Niels-Henrik; Martens, Erik A; Sosnovtseva, Olga

2016-07-01

Through regulation of the extracellular fluid volume, the kidneys provide important long-term regulation of blood pressure. At the level of the individual functional unit (the nephron), pressure and flow control involves two different mechanisms that both produce oscillations. The nephrons are arranged in a complex branching structure that delivers blood to each nephron and, at the same time, provides a basis for an interaction between adjacent nephrons. The functional consequences of this interaction are not understood, and at present it is not possible to address this question experimentally. We provide experimental data and a new modeling approach to clarify this problem. To resolve details of microvascular structure, we collected 3D data from more than 150 afferent arterioles in an optically cleared rat kidney. Using these results together with published micro-computed tomography (μCT) data we develop an algorithm for generating the renal arterial network. We then introduce a mathematical model describing blood flow dynamics and nephron to nephron interaction in the network. The model includes an implementation of electrical signal propagation along a vascular wall. Simulation results show that the renal arterial architecture plays an important role in maintaining adequate pressure levels and the self-sustained dynamics of nephrons.

Intensive systolic blood pressure control and incident chronic kidney disease in people with and without diabetes mellitus: secondary analyses of two randomised controlled trials.

PubMed

Beddhu, Srinivasan; Greene, Tom; Boucher, Robert; Cushman, William C; Wei, Guo; Stoddard, Gregory; Ix, Joachim H; Chonchol, Michel; Kramer, Holly; Cheung, Alfred K; Kimmel, Paul L; Whelton, Paul K; Chertow, Glenn M

2018-07-01

Guidelines, including the 2017 American College of Cardiology and American Heart Association blood pressure guideline, recommend tighter control of systolic blood pressure in people with type 2 diabetes. However, it is unclear whether intensive lowering of systolic blood pressure increases the incidence of chronic kidney disease in this population. We aimed to compare the effects of intensive systolic blood pressure control on incident chronic kidney disease in people with and without type 2 diabetes. The Systolic Blood Pressure Intervention Trial (SPRINT) tested the effects of a systolic blood pressure goal of less than 120 mm Hg (intensive intervention) versus a goal of less than 140 mm Hg (standard intervention) in people without diabetes. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) blood pressure trial tested a similar systolic blood pressure intervention in people with type 2 diabetes. Our study is a secondary analysis of limited access datasets from SPRINT and the ACCORD trial obtained from the National Institutes of Health. In participants without chronic kidney disease at baseline (n=4311 in the ACCORD trial; n=6715 in SPRINT), we related systolic blood pressure interventions (intensive vs standard) to incident chronic kidney disease (defined as >30% decrease in estimated glomerular filtration rate [eGFR] to <60 mL/min per 1·73 m 2 ). These trials are registered with ClinicalTrials.gov, numbers NCT01206062 (SPRINT) and NCT00000620 (ACCORD trial). The average difference in systolic blood pressure between intensive and standard interventions was 13·9 mm Hg (95% CI 13·4-14·4) in the ACCORD trial and 15·2 mm Hg (14·8-15·6) in SPRINT. At 3 years, the cumulative incidence of chronic kidney disease in the ACCORD trial was 10·0% (95% CI 8·8-11·4) with the intensive intervention and 4·1% (3·3-5·1) with the standard intervention (absolute risk difference 5·9%, 95% CI 4·3-7·5). Corresponding values in SPRINT were 3·5% (95% CI 2·9-4·2) and 1·0% (0·7-1·4; absolute risk difference 2·5%, 95% CI 1·8-3·2). The absolute risk difference was significantly higher in the ACCORD trial than in SPRINT (p=0·0001 for interaction). Intensive lowering of systolic blood pressure increased the risk of incident chronic kidney disease in people with and without type 2 diabetes. However, the absolute risk of incident chronic kidney disease was higher in people with type 2 diabetes. Our findings suggest the need for vigilance in monitoring kidney function during intensive antihypertensive drug treatment, particularly in adults with diabetes. Long-term studies are needed to understand the clinical implications of antihypertensive treatment-related reductions in eGFR. National Institutes of Health. Copyright © 2018 Elsevier Ltd. All rights reserved.

Soccer training improves cardiac function in men with type 2 diabetes.

PubMed

Schmidt, Jakob Friis; Andersen, Thomas Rostgaard; Horton, Joshua; Brix, Jonathan; Tarnow, Lise; Krustrup, Peter; Andersen, Lars Juel; Bangsbo, Jens; Hansen, Peter Riis

2013-12-01

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of cardiovascular disease, which is worsened by physical inactivity. Subclinical myocardial dysfunction is associated with increased risk of heart failure and impaired prognosis in T2DM; however, it is not clear if exercise training can counteract the early signs of diabetic heart disease. This study aimed to evaluate the effects of soccer training on cardiac function, exercise capacity, and blood pressure in middle-age men with T2DM. Twenty-one men age 49.8 ± 1.7 yr with T2DM and no history of cardiovascular disease participated in a soccer training group (n = 12) that trained 1 h twice a week or a control group (n = 9) with no change in lifestyle. Examinations included comprehensive transthoracic echocardiography, measurements of blood pressure, maximal oxygen consumption (V(˙)O(2max)), and intermittent endurance capacity before and after 12 and 24 wk. Two-way repeated-measures ANOVA was applied. After 24 wk of soccer training, left ventricular (LV) end-diastolic diameter and volume were increased (P < 0.001) compared to baseline. LV longitudinal systolic displacement was augmented by 23% (P < 0.001) and global longitudinal two-dimensional strain increased by 10% (P < 0.05). LV diastolic function, determined by mitral inflow (E/A ratio) and peak diastolic velocity E', was increased by 18% (P < 0.01) and 29% (P < 0.001), respectively, whereas LV filling pressure E/E' was reduced by 15% (P = 0.05). Systolic, diastolic, and mean arterial pressures were all reduced by 8 mm Hg (P < 0.01, P < 0.001, and P < 0.001, respectively). V(˙)O(2max) and intermittent endurance capacity was 12% and 42% (P < 0.001) higher, respectively. No changes in any of the measured parameters were observed in control group. Regular soccer training improves cardiac function, increases exercise capacity, and lowers blood pressure in men with T2DM.

Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas); Implications for Dive Physiology and Health

PubMed Central

Thompson, Laura A.; Romano, Tracy A.

2016-01-01

Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC) in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression) and Concanavalin A induced lymphocyte proliferation (BrdU incorporation) in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE) and capture/release conditions. Beluga blood samples (n = 4) were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska (n = 9). Human blood samples (n = 4) (Biological Specialty Corporation) were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α = 0.05). Cortisol was significantly higher in Bristol Bay belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and Bristol Bay belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth) as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the ability of animals to fight infection or avoid dive related pathologies. PMID:27746745

Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas); Implications for Dive Physiology and Health.

PubMed

Thompson, Laura A; Romano, Tracy A

2016-01-01

Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC) in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression) and Concanavalin A induced lymphocyte proliferation (BrdU incorporation) in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE) and capture/release conditions. Beluga blood samples ( n = 4) were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska ( n = 9). Human blood samples ( n = 4) (Biological Specialty Corporation) were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α = 0.05). Cortisol was significantly higher in Bristol Bay belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and Bristol Bay belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth) as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the ability of animals to fight infection or avoid dive related pathologies.

10 Ways to Control High Blood Pressure without Medication

MedlinePlus

10 ways to control high blood pressure without medication By making these 10 lifestyle changes, you can lower your blood pressure and reduce ... treating your high blood pressure. If you successfully control your blood pressure with a healthy lifestyle, you ...

Effect of Vestibular Impairment on Cerebral Blood Flow Response to Dynamic Roll Tilt

NASA Technical Reports Server (NTRS)

Serrador, J. M.; Black, F. O.; Schlgel, Todd T.; Lipsitz, L. A.; Wood, S. J.

2008-01-01

Change to upright posture results in reductions in cerebral perfusion pressure due to hydrostatic pressure changes related to gravity. Since vestibular organs, specifically the otoliths, provide information on position relative to gravity, vestibular inputs may assist in adaptation to the upright posture. The goal of this study was to examine the effect of direct vestibular stimulation on cerebral blood flow (CBF). To examine the role of otolith inputs we screened 165 subjects for vestibular function and classified subjects as either normal or impaired based on ocular torsion. Ocular torsion, an indication of otolith function, was assessed during sinusoidal roll tilt of 20 degrees at 0.01 Hz (100 sec per cycle). Subjects with torsion one SD below the mean were classified as impaired while subjects one SD above the mean were considered normal. During one session subjects were placed in a chair that was sinusoidally rotated 25 degrees in the roll plane at five frequencies: 0.25 & 0.125 Hz for 80 sec, 0.0625 Hz for 160 sec and 0.03125 Hz and 0.015625 Hz for 320 sec. During testing, CBF (transcranial Doppler), blood pressure (Finapres), and end tidal CO2 (Puritan Bennet) were measured continuously. Ocular torsion was assessed from infrared images of the eyes. All rotations were done in the dark with subjects fixated on a red LED directly at the center of rotation. In the normal group, dynamic tilt resulted in significant changes in both blood pressure and cerebral blood flow velocity that was related to the frequency of stimulus. In contrast the impaired group did not show similar patterns. As expected normal subjects demonstrated significant ocular torsion that was related to stimulus frequency while impaired subjects had minimal changes. These data suggest that vestibular inputs have direct effects on cerebral blood flow regulation during dynamic tilt. Supported by NASA.

Physical and computational fluid dynamics models for the hemodynamics of the artiodactyl carotid rete.

PubMed

O'Brien, Haley D; Bourke, Jason

2015-12-07

In the mammalian order Artiodactyla, the majority of arterial blood entering the intracranial cavity is supplied by a large arterial meshwork called the carotid rete. This vascular structure functionally replaces the internal carotid artery. Extensive experimentation has demonstrated that the artiodactyl carotid rete drives one of the most effective selective brain cooling mechanisms among terrestrial vertebrates. Less well understood is the impact that the unique morphology of the carotid rete may have on the hemodynamics of blood flow to the cerebrum. It has been hypothesized that, relative to the tubular internal carotid arteries of most other vertebrates, the highly convoluted morphology of the carotid rete may increase resistance to flow during extreme changes in cerebral blood pressure, essentially protecting the brain by acting as a resistor. We test this hypothesis by employing simple and complex physical models to a 3D surface rendering of the carotid rete of the domestic goat, Capra hircus. First, we modeled the potential for increased resistance across the carotid rete using an electrical circuit analog. The extensive branching of the rete equates to a parallel circuit that is bound in series by single tubular arteries, both upstream and downstream. This method calculated a near-zero increase in resistance across the rete. Because basic equations do not incorporate drag, shear-stress, and turbulence, we used computational fluid dynamics to simulate the impact of these computationally intensive factors on resistance. Ultimately, both simple and complex models demonstrated negligible changes in resistance and blood pressure across the arterial meshwork. We further tested the resistive potential of the carotid rete by simulating blood pressures known to occur in giraffes. Based on these models, we found resistance (and blood pressure mitigation as a whole) to be an unlikely function for the artiodactyl carotid rete. Copyright © 2015 Elsevier Ltd. All rights reserved.

Training Status as a Marker of the Relationship between Nitric Oxide, Oxidative Stress, and Blood Pressure in Older Adult Women

PubMed Central

Mourão Jacomini, André; Celso Dutra de Souza, Hugo; da Silva Dias, Danielle; de Oliveira Brito, Janaina; Cezar Pinheiro, Lucas; Bernardino da Silva, Anderson; Fernanda da Silva, Roberta; Alexandre Trapé, Atila; De Angelis, Kátia; Tanus-Santos, José Eduardo; Lia do Amaral, Sandra; Saranz Zago, Anderson

2016-01-01

The purpose of this study was to evaluate the influence of functional fitness and oxidative capacity on the nitric oxide concentration associated with hemodynamic control in older adult women. The sample consisted of 134 women (65.73 ± 6.14 years old). All subjects underwent a physical examination to assess body mass index, waist-hip ratio, body fat measurement by dual energy X-ray absorptiometry, and blood pressure (BP). Training status (TS) was evaluated by indirect determination of maximal oxygen uptake by a treadmill test using Balke protocol modified for older adults. Functional fitness was also evaluated through a “Functional Fitness Battery Test” to determine the general fitness functional index (GFFI). All participants were separated according to the functional fitness (TS1, very weak and weak; TS2, regular; TS3, good and very good). Plasma blood samples were used to evaluate prooxidant and antioxidant activity and nitrite and nitrate concentrations. The general results of this study showed that good levels of TS were related to lower levels of lipoperoxidation and protein damage, higher levels of antioxidant, and higher concentration of nitrite and nitrate. This combination may be responsible for the lower levels of BP in subjects with better TS. PMID:26697141

Training Status as a Marker of the Relationship between Nitric Oxide, Oxidative Stress, and Blood Pressure in Older Adult Women.

PubMed

Jacomini, André Mourão; de Souza, Hugo Celso Dutra; Dias, Danielle da Silva; Brito, Janaina de Oliveira; Pinheiro, Lucas Cezar; da Silva, Anderson Bernardino; da Silva, Roberta Fernanda; Trapé, Atila Alexandre; De Angelis, Kátia; Tanus-Santos, José Eduardo; do Amaral, Sandra Lia; Zago, Anderson Saranz

2015-01-01

The purpose of this study was to evaluate the influence of functional fitness and oxidative capacity on the nitric oxide concentration associated with hemodynamic control in older adult women. The sample consisted of 134 women (65.73 ± 6.14 years old). All subjects underwent a physical examination to assess body mass index, waist-hip ratio, body fat measurement by dual energy X-ray absorptiometry, and blood pressure (BP). Training status (TS) was evaluated by indirect determination of maximal oxygen uptake by a treadmill test using Balke protocol modified for older adults. Functional fitness was also evaluated through a "Functional Fitness Battery Test" to determine the general fitness functional index (GFFI). All participants were separated according to the functional fitness (TS1, very weak and weak; TS2, regular; TS3, good and very good). Plasma blood samples were used to evaluate prooxidant and antioxidant activity and nitrite and nitrate concentrations. The general results of this study showed that good levels of TS were related to lower levels of lipoperoxidation and protein damage, higher levels of antioxidant, and higher concentration of nitrite and nitrate. This combination may be responsible for the lower levels of BP in subjects with better TS.

Role of Ambulatory and Home Blood Pressure Monitoring in Clinical Practice: A Narrative Review

PubMed Central

Shimbo, Daichi; Abdalla, Marwah; Falzon, Louise; Townsend, Raymond R.; Muntner, Paul

2015-01-01

Hypertension, a common cardiovascular disease (CVD) risk factor, is usually diagnosed and treated based on blood pressure readings obtained in the clinic setting. Blood pressure may differ considerably when measured in the clinic versus outside of the clinic setting. Over the past several decades, evidence has accumulated on two approaches for measuring out-of-clinic blood pressure: ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM). Blood pressure measures on ABPM and HBPM each have a stronger association with CVD outcomes than clinic blood pressure. Controversy exists whether ABPM or HBPM is superior for estimating CVD risk, and under what circumstances these methods should be used in clinical practice for assessing out-of-clinic blood pressure. This review describes ABPM and HBPM procedures, the blood pressure phenotypic measures that can be ascertained, and the evidence that supports the use of each approach to measure out-of-clinic blood pressure. This review also describes barriers to the successful implementation of ABPM and HBPM in clinical practice, proposes core competencies for the conduct of these procedures, and highlights important areas for future research. PMID:26457954

Assessing Pharmacy Students’ Ability to Accurately Measure Blood Pressure Using a Blood Pressure Simulator Arm

PubMed Central

Bryant, Ginelle A.; Haack, Sally L.; North, Andrew M.

2013-01-01

Objective. To compare student accuracy in measuring normal and high blood pressures using a simulator arm. Methods. In this prospective, single-blind, study involving third-year pharmacy students, simulator arms were programmed with prespecified normal and high blood pressures. Students measured preset normal and high diastolic and systolic blood pressure using a crossover design. Results. One hundred sixteen students completed both blood pressure measurements. There was a significant difference between the accuracy of high systolic blood pressure (HSBP) measurement and normal systolic blood pressure (NSBP) measurement (mean HSBP difference 8.4 ± 10.9 mmHg vs NSBP 3.6 ± 6.4 mmHg; p<0.001). However, there was no difference between the accuracy of high diastolic blood pressure (HDBP) measurement and normal diastolic blood pressure (NDBP) measurement (mean HDBP difference 6.8 ± 9.6 mmHg vs. mean NDBP difference 4.6 ± 4.5 mmHg; p=0.089). Conclusions. Pharmacy students may need additional instruction and experience with taking high blood pressure measurements to ensure they are able to accurately assess this important vital sign. PMID:23788809

Assessing pharmacy students' ability to accurately measure blood pressure using a blood pressure simulator arm.

PubMed

Bottenberg, Michelle M; Bryant, Ginelle A; Haack, Sally L; North, Andrew M

2013-06-12

To compare student accuracy in measuring normal and high blood pressures using a simulator arm. In this prospective, single-blind, study involving third-year pharmacy students, simulator arms were programmed with prespecified normal and high blood pressures. Students measured preset normal and high diastolic and systolic blood pressure using a crossover design. One hundred sixteen students completed both blood pressure measurements. There was a significant difference between the accuracy of high systolic blood pressure (HSBP) measurement and normal systolic blood pressure (NSBP) measurement (mean HSBP difference 8.4 ± 10.9 mmHg vs NSBP 3.6 ± 6.4 mmHg; p<0.001). However, there was no difference between the accuracy of high diastolic blood pressure (HDBP) measurement and normal diastolic blood pressure (NDBP) measurement (mean HDBP difference 6.8 ± 9.6 mmHg vs. mean NDBP difference 4.6 ± 4.5 mmHg; p=0.089). Pharmacy students may need additional instruction and experience with taking high blood pressure measurements to ensure they are able to accurately assess this important vital sign.

Flavonoid-rich dark chocolate improves endothelial function and increases plasma epicatechin concentrations in healthy adults.

PubMed

Engler, Mary B; Engler, Marguerite M; Chen, Chung Y; Malloy, Mary J; Browne, Amanda; Chiu, Elisa Y; Kwak, Ho-Kyung; Milbury, Paul; Paul, Steven M; Blumberg, Jeffrey; Mietus-Snyder, Michele L

2004-06-01

Dark chocolate derived from the plant (Theobroma cacao) is a rich source of flavonoids. Cardioprotective effects including antioxidant properties, inhibition of platelet activity, and activation of endothelial nitric oxide synthase have been ascribed to the cocoa flavonoids. To investigate the effects of flavonoid-rich dark chocolate on endothelial function, measures of oxidative stress, blood lipids, and blood pressure in healthy adult subjects. The study was a randomized, double-blind, placebo-controlled design conducted over a 2 week period in 21 healthy adult subjects. Subjects were randomly assigned to daily intake of high-flavonoid (213 mg procyanidins, 46 mg epicatechin) or low-flavonoid dark chocolate bars (46 g, 1.6 oz). High-flavonoid chocolate consumption improved endothelium-dependent flow-mediated dilation (FMD) of the brachial artery (mean change = 1.3 +/- 0.7%) as compared to low-flavonoid chocolate consumption (mean change = -0.96 +/- 0.5%) (p = 0.024). No significant differences were noted in the resistance to LDL oxidation, total antioxidant capacity, 8-isoprostanes, blood pressure, lipid parameters, body weight or body mass index (BMI) between the two groups. Plasma epicatechin concentrations were markedly increased at 2 weeks in the high-flavonoid group (204.4 +/- 18.5 nmol/L, p < or = 0.001) but not in the low-flavonoid group (17.5 +/- 9 nmol/L, p = 0.99). Flavonoid-rich dark chocolate improves endothelial function and is associated with an increase in plasma epicatechin concentrations in healthy adults. No changes in oxidative stress measures, lipid profiles, blood pressure, body weight or BMI were seen.

Augmentation of systemic blood pressure during spinal cord ischemia to prevent postoperative paraplegia after aortic surgery in a rabbit model.

PubMed

Izumi, So; Okada, Kenji; Hasegawa, Tomomi; Omura, Atsushi; Munakata, Hiroshi; Matsumori, Masamichi; Okita, Yutaka

2010-05-01

Paraplegia from spinal cord ischemia remains an unresolved complication in thoracoabdominal aortic surgery, with high morbidity and mortality. This study investigated postoperative effects of systemic blood pressure augmentation during ischemia. Spinal cord ischemia was induced in rabbits by infrarenal aortic occlusion for 15 minutes with infused phenylephrine (high blood pressure group, n = 8) or nitroprusside (low blood pressure group, n = 8) or without vasoactive agent (control, n = 8). Spinal cord blood flow, transcranial motor evoked potentials, neurologic outcome, and motor neuron cell damage (apoptosis, necrosis, superoxide generation, myeloperoxidase activity) were evaluated. Mean arterial pressures during ischemia were controlled at 121.9 +/- 2.8, 50.8 +/- 4.3, and 82.3 +/- 10.7 mm Hg in high blood pressure, low blood pressure, and control groups, respectively. In high blood pressure group, high spinal cord blood flow (P < .01), fast recovery of transcranial motor evoked potentials (P < .01), and high neurologic score (P < .05) were observed after ischemia relative to low blood pressure and control groups. At 48 hours after ischemia, there were significantly more viable neurons, fewer terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling-positive neurons, and less alpha-fodrin expression in high blood pressure group than low blood pressure and control groups. Superoxide generation and myeloperoxidase activity at 3 hours after ischemia were suppressed in high blood pressure group relative to low blood pressure group. Augmentation of systemic blood pressure during spinal cord ischemia can reduce ischemic insult and postoperative neurologic adverse events. 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Exploring the relationship of peripheral total bilirubin, red blood cell, and hemoglobin with blood pressure during childhood and adolescence.

PubMed

Chen, Xiao-Tian; Yang, Song; Yang, Ya-Ming; Zhao, Hai-Long; Chen, Yan-Chun; Zhao, Xiang-Hai; Wen, Jin-Bo; Tian, Yuan-Rui; Yan, Wei-Li; Shen, Chong

2017-11-04

Total bilirubin is beneficial for protecting cardiovascular diseases in adults. The authors aimed to investigate the association of total bilirubin, red blood cell, and hemoglobin levels with the prevalence of high blood pressure in children and adolescents. A total of 3776 students (aged from 6 to 16 years old) were examined using cluster sampling. Pre-high blood pressure and high blood pressure were respectively defined as the point of 90th and 95th percentiles based on the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. Both systolic and diastolic blood pressure were standardized into z-scores. Peripheral total bilirubin, red blood cell and hemoglobin levels were significantly correlated with age, and also varied with gender. Peripheral total bilirubin was negatively correlated with systolic blood pressure in 6- and 9-year-old boys, whilst positively correlated with diastolic blood pressure in the 12-year-old boys and 13- to 15-year-old girls (p<0.05). Higher levels of red blood cell and hemoglobin were observed in pre-high blood pressure and high blood pressure students when compared with their normotensive peers (p<0.01). The increases in red blood cell and hemoglobin were significantly associated with high blood pressure after adjusting for confounding factors. The ORs (95% CI) of each of the increases were 2.44 (1.52-3.92) and 1.04 (1.03-1.06), respectively. No statistical association between total bilirubin and high blood pressure was observed (p>0.05). Total bilirubin could be weakly correlated with both systolic and diastolic blood pressure, as correlations varied with age and gender in children and adolescents; in turn, the increased levels of red blood cell and hemoglobin are proposed to be positively associated with the prevalence of high blood pressure. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Consumption of anthocyanin-rich cherry juice for 12 weeks improves memory and cognition in older adults with mild-to-moderate dementia.

PubMed

Kent, Katherine; Charlton, Karen; Roodenrys, Steven; Batterham, Marijka; Potter, Jan; Traynor, Victoria; Gilbert, Hayley; Morgan, Olivia; Richards, Rachelle

2017-02-01

Dietary flavonoids, including anthocyanins, may positively influence cognition and may be beneficial for the prevention and treatment of dementia. We aimed to assess whether daily consumption of anthocyanin-rich cherry juice changed cognitive function in older adults with dementia. Blood pressure and anti-inflammatory effects were examined as secondary outcomes. A 12-week randomised controlled trial assessed cognitive outcomes in older adults (+70 year) with mild-to-moderate dementia (n = 49) after consumption of 200 ml/day of either a cherry juice or a control juice with negligible anthocyanin content. Blood pressure and inflammatory markers (CRP and IL-6) were measured at 6 and 12 weeks. ANCOVA controlling for baseline and RMANOVA assessed change in cognition and blood pressure. Improvements in verbal fluency (p = 0.014), short-term memory (p = 0.014) and long-term memory (p ≤ 0.001) were found in the cherry juice group. A significant reduction in systolic (p = 0.038) blood pressure and a trend for diastolic (p = 0.160) blood pressure reduction was evident in the intervention group. Markers of inflammation (CRP and IL-6) were not altered. Inclusion of an anthocyanin-rich beverage may be a practical and feasible way to improve total anthocyanin consumption in older adults with mild-to-moderate dementia, with potential to improve specific cognitive outcomes.

Genetic Variation in the Presynaptic Norepinephrine Transporter is Associated with Blood Pressure Responses to Exercise in Healthy Humans

PubMed Central

Kohli, Utkarsh; Hahn, Maureen K.; English, Brett A.; Sofowora, Gbenga G.; Muszkat, Mordechai; Li, Chun; Blakely, Randy D.; Stein, C. Michael; Kurnik, Daniel

2011-01-01

Background The presynaptic norepinephrine (NE) transporter (NET) mediates synaptic clearance and recycling of NE. NET-deficient transgenic mice have elevated blood pressure, heart rate, and catecholamine concentrations. However, the in vivo effects of common NET variants on cardiovascular regulation at rest and during exercise are unknown. Methods We studied cardiovascular responses and plasma catecholamine concentrations at rest and during bicycle exercise at increasing workloads (25, 50 and 75 W) in 145 healthy subjects. We used multiple linear regressions to analyze the effect of common, purportedly functional polymorphisms in NET (rs2242446 and rs28386840) on cardiovascular measures. Results 44% and 58.9% of subjects carried at least one variant allele for NET T-182C and A-3081T, respectively. Systolic blood pressure (SBP) during exercise and SBP area-under-the-curve were higher in carriers of variant NET alleles (P=0.003 and 0.009 for T-182C and A-3081T, respectively) and NET haplotype -182C/-081T compared to -82T/-3081A (all P<0.01). Diastolic blood pressure (DBP) during exercise was also higher at lower, but not at higher exercise stages in carriers of NET -182C (P<0.01) and -081T (P< 0.05). NET genotypes were not associated with catecholamine concentrations or heart rate. Conclusion Common genetic NET variants (-182C and -081T) are associated with greater blood pressure response to exercise in humans. PMID:21412203

Phaeochromocytoma in a 86-year-old patient presenting with reversible myocardial dysfunction.

PubMed

Szwench, Elżbieta; P Czkowska, Mariola; Marczewski, Krzysztof; Klisiewicz, Anna; Micha Owska, Ilona; Ciuba, Iwona; Januszewicz, Magdalena; Prejbisz, Aleksander; Hoffman, Piotr; Januszewicz, Andrzej

2011-12-01

BACKGROUND. Phaeochromocytomas and paragangliomas are rare, mostly benign catecholamine-producing tumours of chromaffin cells of the adrenal medulla or of extra-adrenal paraganglia. Phaeochromocytoma may occur at any age, the greatest frequency being in the fourth and fifth decades. Only on extremely rare occasions does the tumour develop in the very old patients. METHODS. We are describing an 86-year-old patient with phaeochromocytoma, presenting with reversible myocardial dysfunction. RESULTS. This very old patient with phaeochromocytoma had hypertension characterized by labile blood pressure values and increased daytime blood pressure variability. This patient exhibited reversible myocardial dysfunction suggestive for "catecholaminergic cardiomyopathy", as the complication of phaeochromocytoma. After surgical removal of the tumour, recovery of left ventricular function was documented by echocardiography showing normalization of systolic function and improvement of diastolic function. CONCLUSION. Phaeochromocytomas are rare forms of secondary hypertension, but should be considered in the differential diagnosis, regardless of age, even in very old patients.

Cocoa, Blood Pressure, and Vascular Function

PubMed Central

Ludovici, Valeria; Barthelmes, Jens; Nägele, Matthias P.; Enseleit, Frank; Ferri, Claudio; Flammer, Andreas J.; Ruschitzka, Frank; Sudano, Isabella

2017-01-01

Cardiovascular disease (CVD) represents the most common cause of death worldwide. The consumption of natural polyphenol-rich foods, and cocoa in particular, has been related to a reduced risk of CVD, including coronary heart disease and stroke. Intervention studies strongly suggest that cocoa exerts a beneficial impact on cardiovascular health, through the reduction of blood pressure (BP), improvement of vascular function, modulation of lipid and glucose metabolism, and reduction of platelet aggregation. These potentially beneficial effects have been shown in healthy subjects as well as in patients with risk factors (arterial hypertension, diabetes, and smoking) or established CVD (coronary heart disease or heart failure). Several potential mechanisms are supposed to be responsible for the positive effect of cocoa; among them activation of nitric oxide (NO) synthase, increased bioavailability of NO as well as antioxidant, and anti-inflammatory properties. It is the aim of this review to summarize the findings of cocoa and chocolate on BP and vascular function. PMID:28824916

The effect of growth hormone treatment on metabolic and cardiovascular risk factors is similar in preterm and term short, small for gestational age children.

PubMed

de Kort, Sandra W K; Willemsen, Ruben H; van der Kaay, Danielle C M; Hokken-Koelega, Anita C S

2009-07-01

We previously reported that short, small for gestational age (SGA) children who were born preterm have a lower body fat percentage and a higher blood pressure, insulin secretion and disposition index than short SGA children born at term. Whether preterm birth also influences these parameters during GH treatment is unknown. To compare blood pressure, insulin sensitivity, beta-cell function and body composition during 4 years of GH treatment, between preterm and term short SGA children. A total of 404 prepubertal non-GH-deficient short SGA children were divided into 143 preterm (< 36 weeks) and 261 term children. Height, blood pressure (n = 404), body composition measured by dual energy X-ray absorptiometry (DXA) (n = 138) and insulin sensitivity and beta-cell function calculated from a frequent sampling intravenous glucose tolerance test (FSIGT) with tolbutamide (n = 74) or from the homeostasis model assessment of insulin resistance (HOMA-IR) (n = 204). In preterm and term children, GH treatment resulted in a similar decrease in systolic and diastolic blood pressure, body fat percentage, limb fat/total fat ratio and insulin sensitivity, and a similar increase in insulin secretion and disposition index. Lean body mass (LBM) corrected for gender and height increased in term children and did not change in preterm children. Multiple regression analysis revealed that this difference in GH effect on LBM was not associated with gestational age. The effect of GH treatment on metabolic and cardiovascular risk factors is similar in preterm and term short, SGA children.

Central autonomic network mediates cardiovascular responses to acute inflammation: Relevance to increased cardiovascular risk in depression?

PubMed Central

Harrison, Neil A.; Cooper, Ella; Voon, Valerie; Miles, Ken; Critchley, Hugo D.

2013-01-01

Inflammation is a risk factor for both depression and cardiovascular disease. Depressed mood is also a cardiovascular risk factor. To date, research into mechanisms through which inflammation impacts cardiovascular health rarely takes into account central effects on autonomic cardiovascular control, instead emphasizing direct effects of peripheral inflammatory responses on endothelial reactivity and myocardial function. However, brain responses to inflammation engage neural systems for motivational and homeostatic control and are expressed through depressed mood state and changes in autonomic cardiovascular regulation. Here we combined an inflammatory challenge, known to evoke an acute reduction in mood, with neuroimaging to identify the functional brain substrates underlying potentially detrimental changes in autonomic cardiovascular control. We first demonstrated that alterations in the balance of low to high frequency (LF/HF) changes in heart rate variability (a measure of baroreflex sensitivity) could account for some of the inflammation-evoked changes in diastolic blood pressure, indicating a central (rather than solely local endothelial) origin. Accompanying alterations in regional brain metabolism (measured using 18FDG-PET) were analysed to localise central mechanisms of inflammation-induced changes in cardiovascular state: three discrete regions previously implicated in stressor-evoked blood pressure reactivity, the dorsal anterior and posterior cingulate and pons, strongly mediated the relationship between inflammation and blood pressure. Moreover, activity changes within each region predicted the inflammation-induced shift in LF/HF balance. These data are consistent with a centrally-driven component originating within brain areas supporting stressor evoked blood pressure reactivity. Together our findings highlight mechanisms binding psychological and physiological well-being and their perturbation by peripheral inflammation. PMID:23416033

Are "functionally related polymorphisms" of renin-angiotensin-aldosterone system gene polymorphisms associated with hypertension?

PubMed

Hahntow, Ines N; Mairuhu, Gideon; van Valkengoed, Irene Gm; Koopmans, Richard P; Michel, Martin C

2010-06-02

Genotype-phenotype association studies are typically based upon polymorphisms or haplotypes comprised of multiple polymorphisms within a single gene. It has been proposed that combinations of polymorphisms in distinct genes, which functionally impact the same phenotype, may have stronger phenotype associations than those within a single gene. We have tested this hypothesis using genes encoding components of the renin-angiotensin-aldosterone system and the high blood pressure phenotype. Our analysis is based on 1379 participants of the cross-sectional SUNSET study randomly selected from the population register of Amsterdam. Each subject was genotyped for the angiotensinogen M235T, the angiotensin-converting enzyme insertion/deletion and the angiotensin II type 1 receptor A1166C polymorphism. The phenotype high blood pressure was defined either as a categorical variable comparing hypertension versus normotension as in most previous studies or as a continuous variable using systolic, diastolic and mean blood pressure in a multiple regression analysis with gender, ethnicity, age, body-mass-index and antihypertensive medication as covariates. Genotype-phenotype relationships were explored for each polymorphism in isolation and for double and triple polymorphism combinations. At the single polymorphism level, only the A allele of the angiotensin II type 1 receptor was associated with a high blood pressure phenotype. Using combinations of polymorphisms of two or all three genes did not yield stronger/more consistent associations. We conclude that combinations of physiologically related polymorphisms of multiple genes, at least with regard to the renin-angiotensin-aldosterone system and the hypertensive phenotype, do not necessarily offer additional benefit in analyzing genotype/phenotype associations.

Prevalence of chronic cardiovascular and metabolic diseases in Senegalese workers: a cross-sectional study, 2010.

PubMed

Seck, Sidy Mohamed; Guéye, Serigne; Tamba, Kéba; Ba, Issa

2013-01-01

Noncommunicable diseases (NCDs) are a major public health threat, particularly in developing countries. In sub-Saharan Africa, the scarcity of reliable data on NCDs in the general population makes it difficult to develop efficient prevention strategies. The objective of this cross-sectional study was to assess the prevalence of 4 cardiometabolic NCDs among 402 private-sector workers in Dakar, Senegal: high blood pressure (HBP), diabetes, obesity, and chronic kidney disease (CKD). We collected demographic, clinical, and biological data for each worker during routine occupational health visits between September 1 and November 30, 2010. Multivariate analyses were performed to identify risk factors associated with NCDs. Among the 402 study participants, 24.1% had HBP, 9.7% had diabetes, 16.7% were obese, and 22.4% had CKD. About half of participants (48.5%) were not aware of their diseases before the screening. Univariate analysis showed that age was significantly associated with blood pressure, fasting blood glucose, and renal function. After adjusting for age and sex, systolic blood pressure was correlated with renal function, and physical inactivity was significantly associated with obesity. Despite its small sample size, our study provides a perspective on the extent of cardiometabolic NCDs in Senegalese workers. Our study also suggests that targeted screening activities focusing on socio-professional groups may be helpful in the absence of national integrated prevention programs.

A survey of blood pressure in Lebanese children and adolescence

PubMed Central

Merhi, Bassem Abou; Al-Hajj, Fatima; Al-Tannir, Mohamad; Ziade, Fouad; El-Rajab, Mariam

2011-01-01

Background: Blood pressure varies between populations due to ethnic and environmental factors. Therefore, normal blood pressure values should be determined for different populations. Aims: The aim of this survey was to produce blood pressure nomograms for Lebanese children in order to establish distribution curves of blood pressure by age and sex. Subjects and Methods: We conducted a survey of blood pressure in 5710 Lebanese schoolchildren aged 5 to 15 years (2918 boys and 2792 girls), and studied the distribution of systolic and diastolic blood pressure in these children and adolescents. Blood pressure was measured with a mercury sphygmomanometer using a standardized technique. Results: Both systolic and diastolic blood pressure had a positive correlation with weight, height, age, and body mass index (r= 0.648, 0.643, 0.582, and 0.44, respectively) (P < .001). There was no significant difference in the systolic and diastolic blood pressure in boys compared to girls of corresponding ages. However, the average annual increase in systolic blood pressure was 2.86 mm Hg in boys and 2.63 mm Hg in girls, whereas the annual increase in diastolic blood pressure was 1.72 mm Hg in boys and 1.48 mm Hg in girls. The prevalence of high and high-normal blood pressure at the upper limit of normal (between the 90th and 95th percentile, at risk of future hypertension if not managed adequately), was 10.5% in boys and 6.9% in girls, with similar distributions among the two sexes. Conclusions: We present the first age-specific reference values for blood pressure of Lebanese children aged 5 to 15 years based on a good representative sample. The use of these reference values should help pediatricians identify children with normal, high-normal and high blood pressure. PMID:22540059

A survey of blood pressure in Lebanese children and adolescence.

PubMed

Merhi, Bassem Abou; Al-Hajj, Fatima; Al-Tannir, Mohamad; Ziade, Fouad; El-Rajab, Mariam

2011-01-01

Blood pressure varies between populations due to ethnic and environmental factors. Therefore, normal blood pressure values should be determined for different populations. The aim of this survey was to produce blood pressure nomograms for Lebanese children in order to establish distribution curves of blood pressure by age and sex. We conducted a survey of blood pressure in 5710 Lebanese schoolchildren aged 5 to 15 years (2918 boys and 2792 girls), and studied the distribution of systolic and diastolic blood pressure in these children and adolescents. Blood pressure was measured with a mercury sphygmomanometer using a standardized technique. Both systolic and diastolic blood pressure had a positive correlation with weight, height, age, and body mass index (r= 0.648, 0.643, 0.582, and 0.44, respectively) (P < .001). There was no significant difference in the systolic and diastolic blood pressure in boys compared to girls of corresponding ages. However, the average annual increase in systolic blood pressure was 2.86 mm Hg in boys and 2.63 mm Hg in girls, whereas the annual increase in diastolic blood pressure was 1.72 mm Hg in boys and 1.48 mm Hg in girls. The prevalence of high and high-normal blood pressure at the upper limit of normal (between the 90(th) and 95(th) percentile, at risk of future hypertension if not managed adequately), was 10.5% in boys and 6.9% in girls, with similar distributions among the two sexes. We present the first age-specific reference values for blood pressure of Lebanese children aged 5 to 15 years based on a good representative sample. The use of these reference values should help pediatricians identify children with normal, high-normal and high blood pressure.

Clinical effects of carvedilol and trimetazidine for the treatmentof alcoholic myocardiopathy.

PubMed

Li, Hui; Liu, Fu-Yuan; Li, Xiao-Lan; Li, Xiao-Mei; Zhu, Lei

2016-08-01

The aim of the study was to compare the clinical effects of carvedilol and trimetazidine for the treatment of alcoholic cardiomyopathy. A total of 60 patients diagnosed with alcoholic cardiomyopathy were enrolled in the study. The patients were randomly divided into the carvedilol (n=20), trimetazidine (n=20) and control (n=20) groups. The patients in the control, carvedilol and trimetazidine groups were treated with conventional drugs, conventional drugs + carvedil and conventional drugs + trimetazidine respectively, for 12 weeks. The patients were compared for their heart functions [left ventricular ejection fraction (LVEF), C-reactive protein (CRP) and 6 min walking], heart rate, blood pressure and heart enlargement (cardiothoracic proportion and left ventricular diameter) before and after treatment. The parameters studied for heart functions, heart rate, blood pressure, heart enlargement, clinical effects before and after treatment were statistically insignificant (p>0.05). After treatment, the carvedilol and trimetazidine groups showed higher LVEF and CRP, longer walking distance in 6 min, as well as lower heart rate and blood pressure (both systolic and diastolic) compared to the control group. Similarly, the cardiothoracic proportion and left ventricular internal diameter for the carvedilol and trimetazidine groups was lower than those of the control group, with better clinical effects (p<0.05). In conclusion, the curative effects of the carvedilol and trimetazidine groups of alcoholic myocardiopathy similar. Both are safe agents that may improve the cardiac function and heart expansion of patients.

Aluminum Trichloride Induces Hypertension and Disturbs the Function of Erythrocyte Membrane in Male Rats.

PubMed

Zhang, Qiuyue; Cao, Zheng; Sun, Xudong; Zuang, Cuicui; Huang, Wanyue; Li, Yanfei

2016-05-01

Aluminum (Al) is the most abundant metal in the earth's crust. Al accumulates in erythrocyte and causes toxicity on erythrocyte membrane. The dysfunction of erythrocyte membrane is a potential risk to hypertension. The high Al content in plasma was associated with hypertension. To investigate the effect of AlCl3 on blood pressure and the function of erythrocyte membrane, the rats were intragastrically exposed to 0, 64(1/20 LD50), 128(1/10 LD50), and 256(1/5 LD50) mg/kg body weight AlCl3 in double distilled water for 120 days, respectively. Then, we determined the systolic and mean arterial blood pressures of rats, the osmotic fragility, the percentage of membrane proteins, the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-pX), and malondialdehyde (MDA) content of the erythrocyte membrane in this experiment. The results showed that AlCl3 elevated the systolic and mean arterial blood pressure of rats, increased the osmotic fragility, decreased the percentage of membrane protein, inhibited the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, CAT, SOD and GSH-pX, and increased the MDA content of erythrocyte membrane. These results indicate that AlCl3 may induce hypertension by disturbing the function of erythrocyte membrane.

[New World of Vascular-Function Developed with CAVI, PWV and ABI].

PubMed

Shirai, Kohji

2014-09-01

Arteriosclerotic diseases are becoming a serious problem all over the world. However, the evaluation of arteriosclerosis quantitatively and non-invasively has been very difficult. Pulse-wave velocities have been used globally. Their significance was mostly established, but the problem is that PWV depends on the blood pressure at the time of measurement. The cardio-ankle vascular index (CAVI) was recently presented and produced from the stiffness parameter beta theory and Bramwell-Hill's equation. CAVI was independent from the blood pressure at the time of measurement. CAVI showed high values in arteriosclerotic diseases, such as coronary stenosis, cervical arteriosclerosis, cerebral infarction, and chronic kidney diseases. Furthermore, CAVI reflected so-called risk factors such as hypertension, diabetes mellitus, dyslipidemia, and smoking. Also, controlling most of those risk factors improved CAVI. A low ankle-brachial blood pressure index (ABI) (< 0.9) reflected stenosis of the femoral artery. ABI (0.9-0.99) has been reported to be a predictor of coronary artery diseases. A combination of those indices might be useful in practical medicine. Furthermore, it is known that arterial stiffness reflects the Windkessel function. The positive correlation between CAVI and the left ventricular function indicated that the heart-arterial relationship could be evaluated using CAVI. Therefore, a new study field involving a collaborating system between heart muscle and arteries could be developed using CAVI.

Blood pressure and cognitive function: a prospective analysis among adolescents in Seychelles.

PubMed

Lyngdoh, Tanica; Viswanathan, Bharathi; Kobrosly, Roni; van Wijngaarden, Edwin; Huber, Brittany; Davidson, Philip W; Cory-Slechta, Deborah A; Strain, John J; Strain, Sean; Myers, Gary J; Bovet, Pascal

2013-06-01

An inverse relationship between blood pressure (BP) and cognitive function has been found in adults, but limited data are available in adolescents and young adults. We examined the prospective relation between BP and cognitive function in adolescence. We examined the association between BP measured at the ages of 12-15 years in school surveys and cognitive endpoints measured in the Seychelles Child Development Study at ages 17 (n = 407) and 19 (n = 429) years, respectively. We evaluated multiple domains of cognition based on subtests of the Cambridge Neurological Test Automated Battery (CANTAB), the Woodcock Johnson Test of Scholastic Achievement (WJTA), the Finger Tapping test (FT) and the Kaufman Brief Intelligence Test (K-BIT). We used age, sex and height-specific z-scores of SBP, DBP and mean arterial pressure (MAP). Six out of the 21 cognitive endpoints tested were associated with BP. However, none of these associations were found to hold for both males and females or for different subtests within the same neurodevelopmental domain or for both SBP and DBP. Most of these associations disappeared when analyses were adjusted for selected potential confounding factors such as socio-economic status, birth weight, gestational age, BMI, alcohol consumption, blood glucose, and total n-3 and n-6 polyunsaturated fats. Our findings do not support a consistent association between BP and subsequent performance on tests assessing various cognitive domains in adolescents.

Variations in respiratory excretion of carbon dioxide can be used to calculate pulmonary blood flow.

PubMed

Preiss, David A; Azami, Takafumi; Urman, Richard D

2015-02-01

A non-invasive means of measuring pulmonary blood flow (PBF) would have numerous benefits in medicine. Traditionally, respiratory-based methods require breathing maneuvers, partial rebreathing, or foreign gas mixing because exhaled CO2 volume on a per-breath basis does not accurately represent alveolar exchange of CO2. We hypothesized that if the dilutional effect of the functional residual capacity was accounted for, the relationship between the calculated volume of CO2 removed per breath and the alveolar partial pressure of CO2 would be reversely linear. A computer model was developed that uses variable tidal breathing to calculate CO2 removal per breath at the level of the alveoli. We iterated estimates for functional residual capacity to create the best linear fit of alveolar CO2 pressure and CO2 elimination for 10 minutes of breathing and incorporated the volume of CO2 elimination into the Fick equation to calculate PBF. The relationship between alveolar pressure of CO2 and CO2 elimination produced an R(2) = 0.83. The optimal functional residual capacity differed from the "actual" capacity by 0.25 L (8.3%). The repeatability coefficient leveled at 0.09 at 10 breaths and the difference between the PBF calculated by the model and the preset blood flow was 0.62 ± 0.53 L/minute. With variations in tidal breathing, a linear relationship exists between alveolar CO2 pressure and CO2 elimination. Existing technology may be used to calculate CO2 elimination during quiet breathing and might therefore be used to accurately calculate PBF in humans with healthy lungs.

Cardiovascular Responses to Skeletal Muscle Stretching: "Stretching" the Truth or a New Exercise Paradigm for Cardiovascular Medicine?

PubMed

Kruse, Nicholas T; Scheuermann, Barry W

2017-12-01

Stretching is commonly prescribed with the intended purpose of increasing range of motion, enhancing muscular coordination, and preventing prolonged immobilization induced by aging or a sedentary lifestyle. Emerging evidence suggests that acute or long-term stretching exercise may modulate a variety of cardiovascular responses. Specifically, at the onset of stretch, the mechanical deformation of the vascular bed coupled with stimulation of group III muscle afferent fibers initiates a cascade of events resulting in both peripheral vasodilation and a heart rate-driven increase in cardiac output, blood pressure, and muscle blood flow. This potential to increase shear stress and blood flow without the use of excessive muscle energy expenditure may hold important implications for future therapeutic vascular medicine and cardiac health. However, the idea that a cardiovascular component may be involved in human skeletal muscle stretching is relatively new. Therefore, the primary intent of this review is to highlight topics related to skeletal muscle stretching and cardiovascular regulation and function. The current evidence suggests that acute stretching causes a significant macro- and microcirculatory event that alters blood flow and the relationship between oxygen availability and oxygen utilization. These acute vascular changes if performed chronically may result in improved endothelial function, improved arterial blood vessel stiffness, and/or reduced blood pressure. Although several mechanisms have been postulated, an increased nitric oxide bioavailability has been highlighted as one promising candidate for the improvement in vessel function with stretching. Collectively, the evidence provided in this review suggests that stretching acutely or long term may serve as a novel and alternative low intensity therapeutic intervention capable of improving several parameters of vascular function.

Regression analysis and transfer function in estimating the parameters of central pulse waves from brachial pulse wave.

PubMed

Chai Rui; Li Si-Man; Xu Li-Sheng; Yao Yang; Hao Li-Ling

2017-07-01

This study mainly analyzed the parameters such as ascending branch slope (A_slope), dicrotic notch height (Hn), diastolic area (Ad) and systolic area (As) diastolic blood pressure (DBP), systolic blood pressure (SBP), pulse pressure (PP), subendocardial viability ratio (SEVR), waveform parameter (k), stroke volume (SV), cardiac output (CO) and peripheral resistance (RS) of central pulse wave invasively and non-invasively measured. These parameters extracted from the central pulse wave invasively measured were compared with the parameters measured from the brachial pulse waves by a regression model and a transfer function model. The accuracy of the parameters which were estimated by the regression model and the transfer function model was compared too. Our findings showed that in addition to the k value, the above parameters of the central pulse wave and the brachial pulse wave invasively measured had positive correlation. Both the regression model parameters including A_slope, DBP, SEVR and the transfer function model parameters had good consistency with the parameters invasively measured, and they had the same effect of consistency. The regression equations of the three parameters were expressed by Y'=a+bx. The SBP, PP, SV, CO of central pulse wave could be calculated through the regression model, but their accuracies were worse than that of transfer function model.

Renal Sympathetic Denervation by CT-Guided Ethanol Injection: A Phase II Pilot Trial of a Novel Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricke, J., E-mail: jens.ricke@med.ovgu.de; Seidensticker, M.; Becker, S.

ObjectivesCT-guided ethanol-mediated renal sympathetic denervation in treatment of therapy-resistant hypertension was performed to assess patient safety and collect preliminary data on treatment efficacy.Materials and MethodsEleven patients with therapy-resistant hypertension (blood pressure of >160 mmHg despite three different antihypertensive drugs including a diuretic) and following screening for secondary causes were enrolled in a phase II single arm open label pilot trial of CT-guided neurolysis of sympathetic renal innervation. Primary endpoint was safety, and secondary endpoint was a decrease of the mean office as well as 24-h systolic blood pressure in follow-up. Follow-up visits at 4 weeks, 3, and 6 months included 24-h blood pressuremore » assessments, office blood pressure, laboratory values, as well as full clinical and quality of life assessments.ResultsNo toxicities ≥3° occurred. Three patients exhibited worsened kidney function in follow-up analyses. When accounting all patients, office systolic blood pressure decreased significantly at all follow-up visits (maximal mean decrease −41.2 mmHg at 3 months). The mean 24-h systolic blood pressure values decreased significantly at 3 months, but not at 6 months (mean: −9.7 and −6.3 mmHg, respectively). Exclusion of five patients who had failed catheter-based endovascular denervation and/or were incompliant for antihypertensive drug intake revealed a more pronounced decrease of 24-h systolic blood pressure (mean: −18.3 and −15.2 mmHg at 3 and 6 months, p = 0.03 and 0.06).ConclusionCT-guided sympathetic denervation proved to be safe and applicable under various anatomical conditions with more renal arteries and such of small diameter.« less

Exercise Blood Pressure Guidelines: Time to Re-evaluate What is Normal and Exaggerated?

PubMed

Currie, Katharine D; Floras, John S; La Gerche, Andre; Goodman, Jack M

2018-03-24

Blood pressure responses to graded exercise testing can provide important diagnostic and prognostic information. While published guidelines outline what constitutes a "normal" and "abnormal" (i.e., exaggerated) blood pressure response to exercise testing, the widespread use of exaggerated blood pressure responses as a clinical tool is limited due to sparse and inconsistent data. A review of the original sources from these guidelines reveals an overall lack of empirical evidence to support both the normal blood pressure responses and their upper limits. In this current opinion, we critically evaluate the current exercise blood pressure guidelines including (1) the normal blood pressure responses to graded exercise testing; (2) the upper limits of this normal response; (3) the blood pressure criteria for test termination; and (4) the thresholds for exaggerated blood pressure responses. We provide evidence that exercise blood pressure responses vary according to subject characteristics, and subsequently a re-evaluation of what constitutes normal and abnormal responses is necessary to strengthen the clinical utility of this assessment.

High blood pressure medicines

MedlinePlus

Hypertension - medicines ... blood vessel diseases. You may need to take medicines to lower your blood pressure if lifestyle changes ... blood pressure to the target level. WHEN ARE MEDICINES FOR HIGH BLOOD PRESSURE USED Most of the ...

[The stakes of force perseverance training and muscle structure training in rehabilitation. Recommendations of the German Federation for Prevention and Rehabilitation of Heart-Circulatory Diseases e.v].

PubMed

Bjarnason-Wehrens, B; Mayer-Berger, W; Meister, E R; Baum, K; Hambrecht, R; Gielen, S

2004-05-01

While aerobic endurance training has been a substantial part of international recommendations for cardiac rehabilitation during the last 30 years, there is still a rather reserved attitude of the medical community to resistance exercise in this field. Careful recommendations for resistance exercise in cardiac patients was only published a few years ago. It has been taken for granted that strength exercise elicits a substantial increase in blood pressure and thus imposes, especially in cardiac patients, a risk of potentially fatal cardiovascular complications. Results of the latest studies show that the existing recommended overcaution is not justified. Strength exercise can indeed result in extreme increases of blood pressure, but this is not the case for all loads of this kind. The actual blood pressure response to strength exercise depends on the isometric component, the exercise intensity (load or resistance used), muscle mass activated, the number of repetitions in the set and/or the duration of the contraction as well as involvement of Valsalva maneuver. Intra arterially performed blood pressure measurements during resistance exercise in patients with heart disease showed that strength training carried out at low intensities (40-60% of MVC) and with high numbers of repetitions (15-20) only evokes a moderate increase of blood pressure comparable with blood pressure measures induced by moderate endurance training. If used properly and performed accurately, individually dosed, medically supervised and controlled through experienced sport therapists, a dynamic resistance exercise is-at least for a certain group of patients-not associated with higher risks than an aerobic endurance training and can in addition to endurance training improve muscle force and endurance, have a positive influence on cardiovascular function, metabolism, cardiovascular risk factors as well as psychosocial well-being and overall quality of life. However, with respect to currently available data, resistance exercise cannot be generally recommended for all groups of patients. The appropriate kind and execution of training is highly dependent on current clinical status, cardiac capacity as well as possible accompanying diseases of the patient. Most of the studies carried out up to date included small samples of middle-aged male patients with almost normal levels of aerobic endurance performance and good left ventricular function. Data is missing for risk groups, older patients and women. Therefore, an integration of dynamic resistance exercises in cardiac rehabilitation can only be recommended without hesitation for CHD patients with high physical capacity (good myocardial function, revascularized). Since patients with myocardial ischemia and/or low left ventricular functioning might develop wall motion disturbances and/or dangerous ventricular arrhythmia when performing resistance exercises, prevalence of the following conditions is recommend: moderate to high LV-function, high physical performance (>5-6 metabolic equivalents= >1.4 watts/kg body weight) in absence of angina pectoris symptoms or ST-depression, by maintained current medication. In the proposed recommendations, a classification of risks for resistance training in cardiac rehabilitation is being made based on current data and is complemented by specific recommendations for particular groups of patients and detailed guidelines for setup and completion of the therapy program.

Contribution of job strain, job status and marital status to laboratory and ambulatory blood pressure in patients with mild hypertension.

PubMed

Blumenthal, J A; Thyrum, E T; Siegel, W C

1995-02-01

The effects of job strain, occupational status, and marital status on blood pressure were evaluated in 99 men and women with mild hypertension. Blood pressure was measured during daily life at home and at work over 15 h of ambulatory blood pressure monitoring. On a separate day, blood pressure was measured in the laboratory during mental stress testing. As expected, during daily life, blood pressure was higher at work than at home. High job strain was associated with elevated systolic blood pressure among women, but not men. However, both men and women with high status occupations had significantly higher blood pressures during daily life and during laboratory mental stress testing. This was especially true for men, in that men with high job status had higher systolic blood pressures than low job status men. Marital status also was an important moderating variable, particularly for women, with married women having higher ambulatory blood pressures than single women. During mental stress testing, married persons had higher systolic blood pressures than unmarried individuals. These data suggest that occupational status and marital status may contribute even more than job strain to variations in blood pressure during daily life and laboratory testing.

Genetic variation in CYP4A11 and blood pressure response to mineralocorticoid receptor antagonism or ENaC inhibition: an exploratory pilot study in African Americans.

PubMed

Laffer, Cheryl L; Elijovich, Fernando; Eckert, George J; Tu, Wanzhu; Pratt, J Howard; Brown, Nancy J

2014-07-01

An rs3890011 variant of CYP4A11, which is in linkage disequilibrium with the loss-of-function variant rs1126742, is associated with hypertension in humans. In mice, Cyp4a deficiency results in salt-sensitive hypertension through activation of ENaC. We tested the hypothesis that the rs3890011 variant is associated with blood pressure response to drugs acting via the ENaC pathway. African Americans with volume-dependent, resistant hypertension were randomized to treatment with placebo, spironolactone, amiloride, or combination. Blood pressure responses were analyzed by CYP4A11 genotypes. Rs3890011 (GG:GC:CC = 20:35:28) and rs1126742 (TT:TC:CC = 45:31:7) were in linkage disequilibrium (D' = 1, r = 0.561). Expected small number of rs1126742 CC homozygotes precluded analysis of the effect of this genotype on treatment responses. Spironolactone reduced blood pressure in rs3890011 GG and GC individuals, but not in CC homozygotes (P = .002), whereas amiloride reduced blood pressure similarly in all rs3890011 genotypes. The antihypertensive effects of spironolactone and amiloride were comparable in GG and GC participants, but only amiloride reduced pressure in CC homozygotes (-6.3 ± 7.3/-3.2 ± 4.0 vs. +6.8 ± 7.9/+4.8 ± 8.6 mm Hg, P < .01/<.05). The aldosterone response to spironolactone was also blunted in the CC genotype. In individuals homozygous for the CYP4A11 rs3890011 C allele, blood pressure is resistant to mineralocorticoid receptor antagonism, but sensitive to ENaC inhibition, consistent with ENaC activation. Studies in a larger population are needed to replicate these findings. Copyright © 2014 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Comparison of noninvasive assessments of central blood pressure using general transfer function and late systolic shoulder of the radial pressure wave.

PubMed

Wohlfahrt, Peter; Krajcoviechová, Alena; Seidlerová, Jitka; Mayer, Otto; Filipovsky, Jan; Cífková, Renata

2014-02-01

Central systolic blood pressure (cSBP) can be derived by the general transfer function of the radial pressure wave, as used in the SphygmoCor device, or by regression equation from directly measured late systolic shoulder of the radial pressure wave (pSBP2), as used in the Omron HEM-9000AI device. The aim of this study was to compare the SphygmoCor estimates of cSBP with 2 estimates of cSBP provided by the Omron HEM-9000AI (cSBP, pSBP2) in a large cohort of the white population. In 391 patients aged 52.3±13.5 years (46% men) from the Czech post-MONICA Study, cSBP was measured using the SphygmoCor and Omron HEM-9000AI devices in random order. Omron cSBP and pSBP2 were perfectly correlated (r = 1.0; P < 0.0001). There was a strong correlation (r = 0.97; P < 0.0001) between Omron and SphygmoCor cSBP estimates, but Omron estimate was 13.1±4.7mm Hg higher than SphygmoCor cSBP. On the other hand, Omron pSBP2 strongly correlated with SphygmoCor cSBP (r = 0.97; P < 0.0001) and was 1.7±4.2mm Hg lower than SphygmoCor cSBP. In multivariable analysis, anthropometric and cardiovascular risk factors explained only 10% of the variance of the cSBP difference between devices while explaining 52% of the systolic blood pressure amplification variance. Estimation of cSBP based on the late systolic shoulder of the radial wave provides a comparable accuracy with the validated general transfer function. When comparing Omron HEM-9000AI and SphygmoCor estimates of cSBP, Omron pSBP2 should be used. The difference between both devices in cSBP may be explained by differences in calibration.

Circuit resistance training attenuates acute exertion-induced reductions in arterial function but not inflammation in obese women.

PubMed

Franklin, Nina C; Robinson, Austin T; Bian, Jing-Tan; Ali, Mohamed M; Norkeviciute, Edita; McGinty, Patrick; Phillips, Shane A

2015-06-01

Cardiovascular disease (CVD) is a leading cause of preventable death among young women in the United States. Habitual resistance exercise training is known to have beneficial effects on endothelial function and CVD risk factors, including obesity; however, previous studies show that acute resistance exercise impairs endothelial function in obese adults who are sedentary, a response that may be linked to inflammation. We sought to determine if circuit-based resistance training (CRT) attenuates acute resistance exercise-induced reductions in endothelial function in a population of young, obese, sedentary women and whether or not inflammation plays a role in this response. Eighteen obese [body mass index (BMI) 30.0-40.0 kg · m(-2)] young premenopausal women were randomly assigned to either a CRT group or a no-exercise control group (CON). Conduit artery endothelial function was assessed using brachial artery flow-mediated dilation (FMD) determined by ultrasound before and after a single bout of strenuous weightlifting (SWL). In addition, circulating inflammatory mediators (tumor necrosis factor-α and C-reactive protein), blood pressure, fasting blood lipids, glucose, waist circumference, body composition, and aerobic capacity were assessed. Among participants randomized to the CRT group, 8 weeks of training led to considerable increases in FMD after SWL (P=0.001) compared to the CON group. However, no significant differences between the groups were observed in circulating inflammatory mediators, blood pressure, fasting blood lipids, or other physical and physiological characteristics. This study shows that CRT alleviates acute exertion-induced reductions in endothelial function among obese sedentary women in the absence of changes in inflammation.

The effects of endothelin-1 on the cardiorespiratory physiology of the freshwater trout (Oncorhynchus mykiss) and the marine dogfish (Squalus acanthias).

PubMed

Perry, S F; Montpetit, C J; McKendry, J; Desforges, P R; Gilmour, K M; Wood, C M; Olson, K R

2001-11-01

The aim of the present study was to evaluate the effects of endothelin-l-elicited cardiovascular events on respiratory gas transfer in the freshwater rainbow trout (Oncorhynchus mykiss) and the marine dogfish (Squalus acanthias). In both species, endothelin-1 (666 pmol kg(-1)) caused a rapid (within 4 min) reduction (ca. 30-50 mmHg) in arterial blood partial pressure of O2. The effects of endothelin-1 on arterial blood partial pressure of CO2 were not synchronised with the changes in O2 partial pressure and the responses were markedly different in trout and dogfish. In trout, arterial CO2 partial pressure was increased transiently by approximately 1.0 mmHg but the onset of the response was delayed and occurred 12 min after endothelin-1 injection. In contrast, CO2 partial pressure remained more-or-less constant in dogfish after injection of endothelin-1 and was increased only slightly (approximately 0.1 mmHg) after 60 min. Pre-treatment of trout with bovine carbonic anhydrase (5 mg ml(-1)) eliminated the increase in CO2 partial pressure that was normally observed after endothelin-1 injection. In both species, endothelin-1 injection caused a decrease in arterial blood pH that mirrored the changes in CO2 partial pressure. Endothelin-1 injection was associated with transient (trout) or persistent (dogfish) hyperventilation as indicated by pronounced increases in breathing frequency and amplitude. In trout, arterial blood pressure remained constant or was decreased slightly and was accompanied by a transient increase in systemic resistance, and a temporary reduction in cardiac output. The decrease in cardiac output was caused solely by a reduction in cardiac frequency; cardiac stroke volume was unaffected. In dogfish, arterial blood pressure was lowered by approximately 10 mmHg at 6-10 min after endothelin-1 injection but then was rapidly restored to pre-injection levels. The decrease in arterial blood pressure reflected an increase in branchial vascular resistance (as determined using in situ perfused gill preparations) that was accompanied by simultaneous decreases in systemic resistance and cardiac output. Cardiac frequency and stroke volume were reduced by endothelin-1 injection and thus both variables contributed to the changes in cardiac output. We conclude that the net consequences of endothelin-1 on arterial blood gases result from the opposing effects of reduced gill functional surface area (caused by vasoconstriction) and an increase in blood residence time within the gill (caused by decreased cardiac output.

Clinical models of cardiovascular regulation after weightlessness

NASA Technical Reports Server (NTRS)

Robertson, D.; Jacob, G.; Ertl, A.; Shannon, J.; Mosqueda-Garcia, R.; Robertson, R. M.; Biaggioni, I.

1996-01-01

After several days in microgravity, return to earth is attended by alterations in cardiovascular function. The mechanisms underlying these effects are inadequately understood. Three clinical disorders of autonomic function represent possible models of this abnormal cardiovascular function after spaceflight. They are pure autonomic failure, baroreflex failure, and orthostatic intolerance. In pure autonomic failure, virtually complete loss of sympathetic and parasympathetic function occurs along with profound and immediate orthostatic hypotension. In baroreflex failure, various degrees of debuffering of blood pressure occur. In acute and complete baroreflex failure, there is usually severe hypertension and tachycardia, while with less complete and more chronic baroreflex impairment, orthostatic abnormalities may be more apparent. In orthostatic intolerance, blood pressure fall is minor, but orthostatic symptoms are prominent and tachycardia frequently occurs. Only careful autonomic studies of human subjects in the microgravity environment will permit us to determine which of these models most closely reflects the pathophysiology brought on by a period of time in the microgravity environment.

Fulminant antenatal pulmonary oedema in a woman with hypertension and superimposed preeclampsia

PubMed Central

Kubota-Sjogren, Yukiko; Nelson-Piercy, Catherine

2015-01-01

An asymptomatic 40-year-old para 1 black African woman with pre-existing hypertension and a booking blood pressure of 120/80 mm Hg, was admitted with superimposed preeclampsia diagnosed because of worsening hypertension and significant proteinuria at 27+5 weeks gestation. Antenatally, her blood pressure was controlled with labetalol, and blood tests including serum creatinine were within normal limits for pregnancy. Three days later, the patient developed severe hypertension despite treatment, and reported sudden onset severe shortness of breath; oxygen saturations on air dropped to 93%. Auscultation revealed widespread crepitations leading to a working diagnosis of pulmonary oedema. Despite appropriate management, respiratory function continued to deteriorate and she required intubation, ventilation and emergency caesarean section under general anaesthesia. A live male infant was delivered floppy and was intubated and resuscitated. He awaits discharge home on oxygen. The mother's pulmonary oedema resolved postpartum. Echocardiogram showed left ventricular hypertrophy but normal left ventricular function and the patient's hypertension is being controlled on medication. PMID:26607194

Microfluidic strategy to investigate dynamics of small blood vessel function

NASA Astrophysics Data System (ADS)

Yasotharan, Sanjesh; Bolz, Steffen-Sebastian; Guenther, Axel

2010-11-01

Resistance arteries (RAs, 30-300 microns in diameter) that are located within the terminal part of the vascular tree regulate the laminar perfusion of tissue with blood, via the peripheral vascular resistance, and hence controls the systemic blood pressure. The structure of RAs is adapted to actively controlling flow resistance by dynamically changing their diameter, which is non-linearly dependent on the temporal variation of the transmural pressure, perfusion flow rate and spatiotemporal changes in the chemical environment. Increases in systemic blood pressure (hypertension) resulting from pathologic changes in the RA response represent the primary risk factor for cardiovascular diseases. We use a microfluidic strategy to investigate small blood vessels by quantifying structural variations within the arterial wall, RA outer contour and diameter over time. First, we document the artery response to vasomotor drugs that were homogeneously applied at step-wise increasing concentration. Second, we investigate the response in the presence of well-defined axial and circumferential heterogeneities. Artery per- and superfusion is discussed based on microscale PIV measurements of the fluid velocity on both sides of the arterial wall. Structural changes in the arterial wall are quantified using cross-correlation and proper orthogonal decomposition analyses of bright-field micrographs.