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Sample records for 1-hour ogtt glucose

  1. Serum 25-hydroxyvitamin D levels in subjects with reduced glucose tolerance and type 2 diabetes - the Tromsø OGTT-study.

    PubMed

    Hutchinson, Moira S; Figenschau, Yngve; Almås, Bjørg; Njølstad, Inger; Jorde, Rolf

    2011-09-01

    The relationships between vitamin D concentrations, hyperglycemia, and insulin resistance remain uncertain. During 2008 - 2010, an oral glucose tolerance test was performed in 3520 subjects from Tromsø, Norway. Serum 25-hydroxyvitamin D [25(OH)D] was measured in 1193 subjects with normal glucose tolerance, in 304 with isolated impaired fasting glucose, in 254 with isolated impaired glucose tolerance, in 139 with a combination of the two, and in 194 subjects with type 2 diabetes. Serum 25(OH)D did not differ between subjects with isolated impaired fasting glucose or impaired glucose tolerance, but was lower in all groups of deranged glucose metabolism as compared with normal subjects. These differences could not be explained by differences in intakes of vitamin D from cod liver oil or other supplements and remained statistically significant after adjustment for gender, age, body mass index, physical activity score, and month of examination. When the cohort was divided according to serum 25(OH)D quartiles, there was an improvement in all measures of glucose metabolism (fasting and 2-hour plasma glucose, serum insulin, HbA(1c)) and estimates of insulin resistance (QUICKI , HOMA-IR, ISI(0.120)) with increasing serum 25(OH)D quartile. However, interventional studies are needed to prove a causal relationship between vitamin D and glucose metabolism.

  2. Incretin effect potentiates beta-cell responsivity to glucose as well as to its rate of change: OGTT and matched intravenous study.

    PubMed

    Campioni, Marco; Toffolo, Gianna; Shuster, Lynne T; Service, F John; Rizza, Robert A; Cobelli, Claudio

    2007-01-01

    The aim of this study is to gain greater insight into the mechanism whereby "incretins" (greater insulinemia after oral than intravenous glucose) enhance insulin secretion. To do so, we use a model of C-peptide secretion to reanalyze data from a previously published study in which glycemic profiles observed following glucose ingestion were matched in the same 10 subjects by means of an intravenous glucose infusion. We report that incretins increase insulin secretion by enhancing both the dynamic (to the rate of increase of glucose) and static (to given glucose concentration) response with an increase of 58% for the static (Phi(s) = 16.4 +/- 1.8 vs. 24.6 +/- 2.0 10(-9) min(-1), P = 0.01) and 63% for the dynamic (Phi(d) = 278 +/- 32 vs. 463 +/- 86 10(-9), P = 0.02) indexes. Since increases in the dynamic response to glucose are believed to be due to an increase in the rate of docking, and exocytosis of insulin containing granules and increases in the static response to glucose are believed to be caused by a shift in the sensitivity of the beta-cell to glucose, these results suggest that incretins may modulate more than one step in the beta-cell insulin secretory cascade.

  3. Glucose screening tests during pregnancy

    MedlinePlus

    Oral glucose tolerance test - pregnancy; OGTT - pregnancy; Glucose challenge test - pregnancy; Gestational diabetes - glucose screening ... first step, you will have a glucose screening test: You DO NOT need to prepare or change ...

  4. Prevalence of Undiagnosed Diabetes in Rheumatoid Arthritis: an OGTT Study.

    PubMed

    Ursini, Francesco; Russo, Emilio; D'Angelo, Salvatore; Arturi, Franco; Hribal, Marta Letizia; D'Antona, Lucia; Bruno, Caterina; Tripepi, Giovanni; Naty, Saverio; De Sarro, Giovambattista; Olivieri, Ignazio; Grembiale, Rosa Daniela

    2016-02-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an excess of cardiovascular disease (CVD) risk, estimated to be at least 50% greater when compared to the general population. Although the widespread diffusion of type 2 diabetes mellitus (T2DM) awareness, there is still a significant proportion of patients with T2DM that remain undiagnosed. Aim of this cross-sectional study was to evaluate the prevalence of undiagnosed diabetes and prediabetes in RA patients. For the present study, 100 consecutive nondiabetic RA patients were recruited. Age- and sex-matched subjects with noninflammatory diseases (osteoarthritis or fibromyalgia) were used as controls. After overnight fasting, blood samples were obtained for laboratory evaluation including serum glucose, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, uric acid, erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein (hs-CRP), rheumatoid factor (RF), and anti-Cyclic Citrullinated Peptide Antibodies (ACPA). A standard Oral Glucose Tolerance Test (OGTT) with 75 g of glucose was performed and blood samples were collected at time 0, 30, 60, 90, and 120 minutes, for measurement of plasma glucose concentrations. The prevalence of impaired fasting glucose (IFG) (9/100 vs 12/100, P = 0.49), impaired glucose tolerance (IGT) (19/100 vs 12/100, P = 0.17), and concomitant IFG/IGT (5/100 vs 9/100, P = 0.27) was similar between groups, whereas the prevalence of diabetes was significantly higher in RA patients (10/100 vs 2/100, P = 0.02). In a logistic regression analysis, increasing age (OR = 1.13, 95% CI 1.028-1.245, P = 0.01) and disease duration (OR = 1.90, 95% CI 1.210-2.995, P = 0.005) were both associated with an increased likelihood of being classified as prediabetes (i.e. IFG and/or IGT) or T2DM. A ROC curve was built to evaluate the predictivity of disease duration on the

  5. Prevalence of Undiagnosed Diabetes in Rheumatoid Arthritis: an OGTT Study

    PubMed Central

    Ursini, Francesco; Russo, Emilio; D’Angelo, Salvatore; Arturi, Franco; Hribal, Marta Letizia; D’Antona, Lucia; Bruno, Caterina; Tripepi, Giovanni; Naty, Saverio; De Sarro, Giovambattista; Olivieri, Ignazio; Grembiale, Rosa Daniela

    2016-01-01

    Abstract Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an excess of cardiovascular disease (CVD) risk, estimated to be at least 50% greater when compared to the general population. Although the widespread diffusion of type 2 diabetes mellitus (T2DM) awareness, there is still a significant proportion of patients with T2DM that remain undiagnosed. Aim of this cross-sectional study was to evaluate the prevalence of undiagnosed diabetes and prediabetes in RA patients. For the present study, 100 consecutive nondiabetic RA patients were recruited. Age- and sex-matched subjects with noninflammatory diseases (osteoarthritis or fibromyalgia) were used as controls. After overnight fasting, blood samples were obtained for laboratory evaluation including serum glucose, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, uric acid, erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein (hs-CRP), rheumatoid factor (RF), and anti-Cyclic Citrullinated Peptide Antibodies (ACPA). A standard Oral Glucose Tolerance Test (OGTT) with 75 g of glucose was performed and blood samples were collected at time 0, 30, 60, 90, and 120 minutes, for measurement of plasma glucose concentrations. The prevalence of impaired fasting glucose (IFG) (9/100 vs 12/100, P = 0.49), impaired glucose tolerance (IGT) (19/100 vs 12/100, P = 0.17), and concomitant IFG/IGT (5/100 vs 9/100, P = 0.27) was similar between groups, whereas the prevalence of diabetes was significantly higher in RA patients (10/100 vs 2/100, P = 0.02). In a logistic regression analysis, increasing age (OR = 1.13, 95% CI 1.028–1.245, P = 0.01) and disease duration (OR = 1.90, 95% CI 1.210–2.995, P = 0.005) were both associated with an increased likelihood of being classified as prediabetes (i.e. IFG and/or IGT) or T2DM. A ROC curve was built to evaluate the predictivity of disease

  6. New-onset diabetes after transplantation--role of oral glucose tolerance test for diagnosis and study of risk factors.

    PubMed

    Sahay, Manisha; Sahay, Rakesh K; Narayan, Girish

    2013-09-01

    To determine the role of the oral glucose tolerance test in the early detection of new-onset diabetes after transplantation (NODAT) and to compare the various risk factors and insulin kinetics in the transplant patients, we studied 41 live-related renal allograft recipients who were not diabetic before transplantation. Immunosuppression included triple drug therapy (cyclosporine, azathioprine and steroids) and rejection episodes were treated with methyl prednisolone (30 mg/kg IV × 3 days). All the study patients were subjected to an oral glucose tolerance test (OGTT) at Day 90 post-transplant and classified as having normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and NODAT as per the World Health Organization guidelines. Insulin levels were also determined at 0, ½ hour, 1 hour and 2 hours during OGTT. NODAT was noted in 29.2% of the study patients, IFG in 4.8% of the study patients and NGT in 65.8% of the study patients. All the groups had normal fasting plasma glucose, but higher than normal insulin levels, suggesting insulin resistance. The patients with overt NODAT had, in addition, low fasting insulin (insulin secretory defect). OGTT may be used for the early detection of NODAT. Although insulin resistance is detected in the majority of post-transplant patients, NODAT also reveals also an insulin secretory defect.

  7. PERFORMANCE OF A1C VERSUS OGTT FOR THE DIAGNOSIS OF PREDIABETES IN A COMMUNITY-BASED SCREENING

    PubMed Central

    Camacho, Jenny E.; Shah, Vallabh O.; Schrader, Ronald; Wong, Craig S.; Burge, Mark R.

    2017-01-01

    Objective Reliable identification of individuals at risk for developing diabetes is critical to instituting preventative strategies. Studies suggest that the accuracy of using A1c as a sole diagnostic criterion for diabetes may be variable across different ethnic groups. We postulate that there will be lack of concordance between A1c and the Oral Glucose Tolerance Test (OGTT) for diagnosing prediabetes across Hispanic and Non-Hispanic White (NHW) populations. Research Design and Methods 218 asymptomatic adults at risk for Type 2 Diabetes (T2D) were assessed with A1c and OGTT for the diagnosis of prediabetes. Glucose homeostasis status was assigned as no diabetes (A1c < 5.7%), prediabetes (A1c 5.7% – 6.4%), and T2D (A1c > 6.4%). Inclusion criteria were age > 18 years and at least one of the following: a family history of diabetes, a history of gestational diabetes, Hispanic ethnicity, non-Caucasian race, or obesity. Subjects received a fasting 75-gram OGTT and A1c on the same day. Bowker’s Test of Symmetry was employed to determine agreement between the tests. Results Data from 99 Hispanic patients and 79 NHW patients were analyzed. There was no concordance between A1c and OGTT for Hispanic (p=0.002) or NHW individuals (p=0.003) with prediabetes. Conclusions A1c is discordant with OGTT among Hispanic and NHW subjects for the diagnosis of prediabetes. Sole use of A1c to designate glycemic status will result in a greater prevalence of prediabetes among Hispanic and NHW New Mexicans. PMID:27482613

  8. Effects of Exercise Intensity on Postprandial Improvement in Glucose Disposal and Insulin Sensitivity in Prediabetic Adults

    PubMed Central

    Rynders, Corey A.; Weltman, Judy Y.; Jiang, Boyi; Breton, Marc; Patrie, James; Barrett, Eugene J.

    2014-01-01

    Background: A single bout of exercise improves postprandial glycemia and insulin sensitivity in prediabetic patients; however, the impact of exercise intensity is not well understood. The present study compared the effects of acute isocaloric moderate (MIE) and high-intensity (HIE) exercise on glucose disposal and insulin sensitivity in prediabetic adults. Methods: Subjects (n = 18; age 49 ± 14 y; fasting glucose 105 ± 11 mg/dL; 2 h glucose 170 ± 32 mg/dL) completed a peak O2 consumption/lactate threshold (LT) protocol plus three randomly assigned conditions: 1) control, 1 hour of seated rest, 2) MIE (at LT), and 3) HIE (75% of difference between LT and peak O2 consumption). One hour after exercise, subjects received an oral glucose tolerance test (OGTT). Plasma glucose, insulin, and C-peptide concentrations were sampled at 5- to 10-minute intervals at baseline, during exercise, after exercise, and for 3 hours after glucose ingestion. Total, early-phase, and late-phase area under the glucose and insulin response curves were compared between conditions. Indices of insulin sensitivity (SI) were derived from OGTT data using the oral minimal model. Results: Compared with control, SI improved by 51% (P = .02) and 85% (P < .001) on the MIE and HIE days, respectively. No differences in SI were observed between the exercise conditions (P = .62). Improvements in SI corresponded to significant reductions in the glucose, insulin, and C-peptide area under the curve values during the late phase of the OGTT after HIE (P < .05), with only a trend for reductions after MIE. Conclusion: These results suggest that in prediabetic adults, acute exercise has an immediate and intensity-dependent effect on improving postprandial glycemia and insulin sensitivity. PMID:24243632

  9. Effect of glucose ingestion in plasma markers of inflammation and oxidative stress: analysis of 16 plasma markers from oral glucose tolerance test samples of normal and diabetic patients.

    PubMed

    Choi, Hyung Jin; Jeon, Soon Young; Hong, Won Kyung; Jung, Seung Eun; Kang, Hyun Ju; Kim, Jun-Woo; Jeon, Jae-Pil; Han, Bok-Ghee

    2013-02-01

    Sixteen plasma markers of inflammation and oxidative stress were measured during OGTT in 54 subjects. Leptin, RBP4, CRP, OPN, ANG, MDC, and MCSF concentrations significantly decreased during OGTT (P<0.05). IL6, IL8, and MCP3 concentrations significantly increased during OGTT (P<0.05). These results provide evidence that glucose ingestion affects systemic inflammation and oxidative stress.

  10. To explain the variation of OGTT dynamics by biological mechanisms: a novel approach based on principal components analysis in women with history of GDM.

    PubMed

    Göbl, Christian S; Bozkurt, Latife; Mittlböck, Martina; Leutner, Michael; Yarragudi, Rajashri; Tura, Andrea; Pacini, Giovanni; Kautzky-Willer, Alexandra

    2015-07-01

    Early reexamination of carbohydrate metabolism via an oral glucose tolerance test (OGTT) is recommended after pregnancy with gestational diabetes (GDM). In this report, we aimed to assess the dominant patterns of dynamic OGTT measurements and subsequently explain them by meanings of the underlying pathophysiological processes. Principal components analysis (PCA), a statistical procedure that aims to reduce the dimensionality of multiple interrelated measures to a set of linearly uncorrelated variables (the principal components) was performed on OGTT data of glucose, insulin and C-peptide in addition to age and body mass index (BMI) of 151 women (n = 110 females after GDM and n = 41 controls) at 3-6 mo after delivery. These components were explained by frequently sampled intravenous glucose tolerance test (FSIGT) parameters. Moreover, their relation with the later development of overt diabetes was studied. Three principal components (PC) were identified, which explained 71.5% of the variation of the original 17 variables. PC1 (explained 47.1%) was closely related to postprandial OGTT levels and FSIGT-derived insulin sensitivity (r = 0.68), indicating that it mirrors insulin sensitivity in the skeletal muscle. PC2 (explained 17.3%) and PC3 (explained 7.1%) were shown to be associated with β-cell failure and fasting (i.e., hepatic) insulin resistance, respectively. All three components were related with diabetes progression (occurred in n = 25 females after GDM) and showed significant changes in long-term trajectories. A high amount of the postpartum OGTT data is explained by principal components, representing pathophysiological mechanisms on the pathway of impaired carbohydrate metabolism. Our results improve our understanding of the underlying biological processes to provide an accurate postgestational risk stratification.

  11. Response of incretins (GIP and GLP-1) to an oral glucose load in female and male subjects with normal glucose tolerance.

    PubMed

    Matsuo, Toshihiro; Kusunoki, Yoshiki; Katsuno, Tomoyuki; Ikawa, Takashi; Akagami, Takafumi; Murai, Kazuki; Miuchi, Masayuki; Miyagawa, Jun-ichiro; Namba, Mitsuyoshi

    2014-11-01

    The aim of this study was to analyze the blood glucose profile and the response of incretins in healthy young subjects by the 75 g oral glucose tolerance test (OGTT). We first reported that plasma glucose and GIP levels were higher in males during the early phase of the OGTT.

  12. Glucose tolerance test - non-pregnant

    MedlinePlus

    Oral glucose tolerance test - non-pregnant; OGTT - non-pregnant; Diabetes - glucose tolerance test; Diabetic - glucose tolerance test ... The most common glucose tolerance test is the oral glucose ... the test begins, a sample of blood will be taken. You will then ...

  13. One-Hour Postload Plasma Glucose Levels Are Associated with Kidney Dysfunction

    PubMed Central

    Succurro, Elena; Arturi, Franco; Lugarà, Marina; Grembiale, Alessandro; Fiorentino, Teresa Vanessa; Caruso, Vittoria; Andreozzi, Francesco; Sciacqua, Angela; Hribal, Marta Letizia; Perticone, Francesco

    2010-01-01

    Background and objectives: A cutoff of 155 mg/dl for 1-hour postload plasma glucose (1hPG) during the oral glucose tolerance test (OGTT) is able to identify patients who are at high risk for type 2 diabetes and vascular atherosclerosis. We aimed to examine whether individuals with 1hPG ≥155 mg/dl are also at increased risk for chronic kidney disease (CKD). Design, setting, participants, & measurements: Atherosclerosis risk factors, OGTT, and estimated GFR by Chronic Kidney Disease Epidemiology Collaboration equation were analyzed in 1075 white individuals without diabetes. Results: The area under the receiver operating characteristic curve for 1hPG was the highest (0.700) compared with the areas under the receiver operating characteristic curve of 0, 30-minute, and 2-hour glucose concentrations. Individuals with 1hPG ≥155 mg/dl had a worse cardiometabolic risk profile, exhibiting significantly higher body mass index, BP, triglycerides, and fasting insulin levels and lower HDL, IGF-1 levels, and insulin sensitivity, than individuals with 1hPG <155 mg/dl. Estimated GFR was significantly lower in individuals with 1hPG ≥155 mg/dl. In a logistic regression model adjusted for age and gender, individuals with 1hPG ≥155 mg/dl showed an increased risk for CKD compared with individuals with 1hPG <155 mg/dl. When the logistic regression analysis was restricted to individuals who had normal glucose tolerance, those with 1hPG ≥155 mg/dl showed a higher risk for CKD compared with individuals with 1hPG <155 mg/dl. Conclusions: These data suggest that a cutoff point of 155 mg/dl for the 1hPG during OGTT may be helpful in the identification of individuals who are at increased risk for CKD. PMID:20595688

  14. Simulation of oral glucose tolerance tests and the corresponding isoglycemic intravenous glucose infusion studies for calculation of the incretin effect.

    PubMed

    Kim, Myeungseon; Oh, Tae Jung; Lee, Jung Chan; Choi, Karam; Kim, Min Young; Kim, Hee Chan; Cho, Young Min; Kim, Sungwan

    2014-03-01

    The incretin effect, which is a unique stimulus of insulin secretion in response to oral ingestion of nutrients, is calculated by the difference in insulin secretory responses from an oral glucose tolerance test (OGTT) and a corresponding isoglycemic intravenous glucose infusion (IIGI) study. The OGTT model of this study, which is individualized by fitting the glucose profiles during an OGTT, was developed to predict the glucose profile during an IIGI study in the same subject. Also, the model predicts the insulin and incretin profiles during both studies. The incretin effect, estimated by simulation, was compared with that measured by physiologic studies from eight human subjects with normal glucose tolerance, and the result exhibited a good correlation (r > 0.8); the incretin effect from the simulation was 56.5% ± 10.6% while the one from the measured data was 52.5% ± 19.6%. In conclusion, the parameters of the OGTT model have been successfully estimated to predict the profiles of both OGTTs and IIGI studies. Therefore, with glucose data from the OGTT alone, this model could control and predict the physiologic responses, including insulin secretion during OGTTs and IIGI studies, which could eventually eliminate the need for complex and cumbersome IIGI studies in incretin research.

  15. Metabolite Profiles During Oral Glucose Challenge

    PubMed Central

    Ho, Jennifer E.; Larson, Martin G.; Vasan, Ramachandran S.; Ghorbani, Anahita; Cheng, Susan; Rhee, Eugene P.; Florez, Jose C.; Clish, Clary B.; Gerszten, Robert E.; Wang, Thomas J.

    2013-01-01

    To identify distinct biological pathways of glucose metabolism, we conducted a systematic evaluation of biochemical changes after an oral glucose tolerance test (OGTT) in a community-based population. Metabolic profiling was performed on 377 nondiabetic Framingham Offspring cohort participants (mean age 57 years, 42% women, BMI 30 kg/m2) before and after OGTT. Changes in metabolite levels were evaluated with paired Student t tests, cluster-based analyses, and multivariable linear regression to examine differences associated with insulin resistance. Of 110 metabolites tested, 91 significantly changed with OGTT (P ≤ 0.0005 for all). Amino acids, β-hydroxybutyrate, and tricarboxylic acid cycle intermediates decreased after OGTT, and glycolysis products increased, consistent with physiological insulin actions. Other pathways affected by OGTT included decreases in serotonin derivatives, urea cycle metabolites, and B vitamins. We also observed an increase in conjugated, and a decrease in unconjugated, bile acids. Changes in β-hydroxybutyrate, isoleucine, lactate, and pyridoxate were blunted in those with insulin resistance. Our findings demonstrate changes in 91 metabolites representing distinct biological pathways that are perturbed in response to an OGTT. We also identify metabolite responses that distinguish individuals with and without insulin resistance. These findings suggest that unique metabolic phenotypes can be unmasked by OGTT in the prediabetic state. PMID:23382451

  16. Metabolite profiles during oral glucose challenge.

    PubMed

    Ho, Jennifer E; Larson, Martin G; Vasan, Ramachandran S; Ghorbani, Anahita; Cheng, Susan; Rhee, Eugene P; Florez, Jose C; Clish, Clary B; Gerszten, Robert E; Wang, Thomas J

    2013-08-01

    To identify distinct biological pathways of glucose metabolism, we conducted a systematic evaluation of biochemical changes after an oral glucose tolerance test (OGTT) in a community-based population. Metabolic profiling was performed on 377 nondiabetic Framingham Offspring cohort participants (mean age 57 years, 42% women, BMI 30 kg/m(2)) before and after OGTT. Changes in metabolite levels were evaluated with paired Student t tests, cluster-based analyses, and multivariable linear regression to examine differences associated with insulin resistance. Of 110 metabolites tested, 91 significantly changed with OGTT (P ≤ 0.0005 for all). Amino acids, β-hydroxybutyrate, and tricarboxylic acid cycle intermediates decreased after OGTT, and glycolysis products increased, consistent with physiological insulin actions. Other pathways affected by OGTT included decreases in serotonin derivatives, urea cycle metabolites, and B vitamins. We also observed an increase in conjugated, and a decrease in unconjugated, bile acids. Changes in β-hydroxybutyrate, isoleucine, lactate, and pyridoxate were blunted in those with insulin resistance. Our findings demonstrate changes in 91 metabolites representing distinct biological pathways that are perturbed in response to an OGTT. We also identify metabolite responses that distinguish individuals with and without insulin resistance. These findings suggest that unique metabolic phenotypes can be unmasked by OGTT in the prediabetic state.

  17. No differences in metabolic outcomes between nadir GH 0.4 and 1.0 ng/mL during OGTT in surgically cured acromegalic patients (observational study)

    PubMed Central

    Ku, Cheol Ryong; Choe, Eun Yeong; Hong, Jae Won; Kim, Eui Hyun; Park, Se Hee; Kim, Sun Ho; Lee, Eun Jig

    2016-01-01

    Abstract Metabolic impairment is the common cause for mortality in acromegalic patients. In this study, long-term improvements of metabolic parameters were evaluated according to 2 different remission criteria. This was an observational cohort study before and up to 1 year after transsphenoidal adenomectomy (TSA). Participants were 187 patients with acromegaly. At 6 months after TSA, remitted patients with age- and sex-matched normalized IGF-1 were divided into 2 groups: remission 1 (R1), nadir growth hormone (GH) below 0.4 ng/mL; and remission 2 (R2), nadir GH between 0.4 and 1.0 ng/mL in oral glucose tolerance test (OGTT). Metabolic parameters during serial OGTTs were evaluated for 12 months. Remission was achieved in 157 (R1–136; R2–21) patients. Immediate postoperative metabolic parameters including body weight, body mass index, glucose, insulin, and free fatty acid in OGTT were all significantly improved in R1 and R2. HOMA-%β and HOMA-IR scores also improved in both R1 and R2. These improvements persisted for duration (12 months) of this study. However, no difference was present in metabolic parameters between R1 and R2. Although the patients with preoperative adrenal insufficiency presented significantly increased HOMA scores before TSA, there was no difference between classifications of deficient pituitary axes and changes of metabolic parameters after TSA. Remitted patients exhibited rapid restoration of metabolic parameters immediate postoperative period. Long-term improvements in metabolic parameters were not different between the 2 different nadir GH cut-offs, 0.4 and 1.0 ng/mL. PMID:27310957

  18. Simulation on how to customize glucose adjustment method for non-invasive blood glucose sensing by NIRS

    NASA Astrophysics Data System (ADS)

    Min, Xiaolin; Jiang, Jingying; Zou, Da; Liu, Rong; Xu, Kexin

    2013-02-01

    Previous studies have shown the limitations of taking OGTT (Oral Glucose Tolerance Test) as the glucose adjustment protocol for non-invasive blood glucose sensing. Previous studies built a mathematical model of glucose metabolism system-IMM (the Integrated Minimal Model) to probe other available adjustment methods. In this talk, a further study would be focused on more detailed combination options of different glucose input types for glucose adjustment projects in non-invasive blood glucose sensing. And predictive models of blood glucose concentration have been established by means of partial least squares (PLS) method, which could be used to evaluate the quality of different glucose adjustment options. Results of PLS modeling suggested that predictive models under combined glucose input types, compared with OGTT, show a great enhancement in the stability. This would finally improve the precision of non-invasive blood glucose sensing.

  19. The immediate effects of a single bout of aerobic exercise on oral glucose tolerance across the glucose tolerance continuum

    PubMed Central

    Knudsen, Sine H.; Karstoft, Kristian; Pedersen, Bente K.; van Hall, Gerrit; Solomon, Thomas P. J.

    2014-01-01

    Abstract We investigated glucose tolerance and postprandial glucose fluxes immediately after a single bout of aerobic exercise in subjects representing the entire glucose tolerance continuum. Twenty‐four men with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or type 2 diabetes (T2D; age: 56 ± 1 years; body mass index: 27.8 ± 0.7 kg/m2, P > 0.05) underwent a 180‐min oral glucose tolerance test (OGTT) combined with constant intravenous infusion of [6,6‐2H2]glucose and ingestion of [U‐13C]glucose, following 1 h of exercise (50% of peak aerobic power) or rest. In both trials, plasma glucose concentrations and kinetics, insulin, C‐peptide, and glucagon were measured. Rates (mg kg−1 min−1) of glucose appearance from endogenous (RaEndo) and exogenous (oral glucose; RaOGTT) sources, and glucose disappearance (Rd) were determined. We found that exercise increased RaEndo, RaOGTT, and Rd (all P < 0.0001) in all groups with a tendency for a greater (~20%) peak RaOGTT value in NGT subjects when compared to IGT and T2D subjects. Accordingly, following exercise, the plasma glucose concentration during the OGTT was increased in NGT subjects (P < 0.05), while unchanged in subjects with IGT and T2D. In conclusion, while a single bout of moderate‐intensity exercise increased the postprandial glucose response in NGT subjects, glucose tolerance following exercise was preserved in the two hyperglycemic groups. Thus, postprandial plasma glucose responses immediately following exercise are dependent on the underlying degree of glycemic control. PMID:25168869

  20. 76 FR 28661 - Interim Final Determination To Defer Sanctions, Sacramento Metro 1-Hour Ozone Nonattainment Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... AGENCY 40 CFR Part 52 Interim Final Determination To Defer Sanctions, Sacramento Metro 1-Hour Ozone... the Sacramento Metro 1- hour Ozone nonattainment area (Sacramento Metro Area) to satisfy anti- backsliding requirements for the 1-hour Ozone standard. DATES: This interim final determination is...

  1. Preserved glucagon-like peptide-1 responses to oral glucose, but reduced incretin effect, insulin secretion and sensitivity in young Asians with type 2 diabetes mellitus

    PubMed Central

    Yeow, Toh Peng; Pacini, Giovanni; Tura, Andrea; Lim, Shueh Lin; Tan, Florence Hui Sieng; Tong, Chin Voon; Hong, Janet Yeow Hua; Md Zain, Fuziah; Holst, Jens Juul; Wan Mohamud, Wan Nazaimoon

    2017-01-01

    Objective Youth onset type 2 diabetes mellitus (YT2DM) is a globally rising phenomenon with substantial Asians representation. The understanding of its pathophysiology is derived largely from studies in the obese African-American and Caucasian populations, while studies on incretin effect are scarce. We examined the insulin resistance, β-cell function (BC), glucagon-like peptide (GLP)-1 hormone and incretin effect in Asian YT2DM. Research design and methods This case–control study recruited 25 Asian YT2DM and 15 healthy controls, matched for gender, ethnicity and body mass index. Serum glucose, insulin, C peptide and GLP-1 were sampled during 2-hour oral glucose tolerance tests (OGTTs) and 1-hour intravenous glucose tolerance tests (IVGTTs). Insulin sensitivity was derived from the Quantitative Insulin Sensitivity Check Index (QUICKI), Oral Glucose Insulin Sensitivity Index (OGIS) in OGTT and surrogate index of SI from the minimal model (calculated SI, CSI). Acute insulin response (AIR) was obtained from IVGTT. Total BC was computed as incremental area under the curve of insulin/incremental area under the curve of glucose, during OGTT (BCOG) and IVGTT (BCIV), respectively. Disposition index (DI) was calculated using the product of insulin sensitivity and insulin secretion. GLP-1 response to oral glucose was calculated as incremental area under the curve of GLP-1 (ΔAUCGLP-1). Per cent incretin effect was estimated as 100×(BCOG−BCIV)/BCOG). Results The YT2DM had marked impairment in BC (>80% reduction in AIR and BCOG, p<0.001) and lower QUICKI (p<0.001), OGIS (p<0.001) and CSI (p=0.015) compared with controls. There was no difference in GLP-1 at all time points and ΔAUCGLP-1 but the per cent incretin effect was reduced in the YT2DM compared with controls (12.1±8.93 vs 70.0±4.03, p<0.001). Conclusions Asian YT2DM showed similar GLP-1 response to oral glucose as controls but reduced incretin effect, BC and insulin sensitivity. The lack of compensatory

  2. An integrated glucose-insulin model to describe oral glucose tolerance test data in healthy volunteers.

    PubMed

    Silber, Hanna E; Frey, Nicolas; Karlsson, Mats O

    2010-03-01

    The extension of the previously developed integrated models for glucose and insulin (IGI) to include the oral glucose tolerance test (OGTT) in healthy volunteers could be valuable to better understand the differences between healthy individuals and those with type 2 diabetes mellitus (T2DM). Data from an OGTT in 23 healthy volunteers were used. Analysis was based on the previously developed intravenous model with extensions for glucose absorption and incretin effect on insulin secretion. The need for additional structural components was evaluated. The model was evaluated by simulation and a bootstrap. Multiple glucose and insulin concentration peaks were observed in most individuals as well as hypoglycemic episodes in the second half of the experiment. The OGTT data were successfully described by the extended basic model. An additional control mechanism of insulin on glucose production improved the description of the data. The model showed good predictive properties, and parameters were estimated with good precision. In conclusion, a previously presented integrated model has been extended to describe glucose and insulin concentrations in healthy volunteers following an OGTT. The characterization of the differences between the healthy and diabetic stages in the IGI model could potentially be used to extrapolate drug effect from healthy volunteers to T2DM.

  3. Acute effects of concentric and eccentric exercise on glucose metabolism and interleukin-6 concentration in healthy males

    PubMed Central

    Krüsmann, PJ; Mersa, L; Eder, EM; Gatterer, H; Melmer, A; Ebenbichler, C; Burtscher, M

    2016-01-01

    Acute muscle-damaging eccentric exercise (EE) negatively affects glucose metabolism. On the other hand, long-term eccentric endurance exercise seems to result in equal or superior positive effects on glucose metabolism compared to concentric endurance exercise. However, it is not known if acute non-muscle-damaging EE will have the same positive effects on glucose metabolism as acute concentric exercise (CE). Interleukin-6 (IL-6) released from the exercising muscles may be involved in the acute adaptations of glucose metabolism after CE and non-muscle-damaging EE. The aim of this study was to assess acute effects of uphill walking (CE) and non-muscle-damaging downhill walking (EE) on glucose metabolism and IL-6 secretion. Seven sedentary non-smoking, healthy males participated in a crossover trial consisting of a 1 h uphill (CE) and a 1 h downhill (EE) walking block on a treadmill. Venous blood samples were drawn before (pre), directly after (acute) and 24 h after (post) exercise. An oral glucose tolerance test (OGTT) was performed before and 24 h after exercise. Glucose tolerance after 1 and 2 hours significantly improved 24 hours after CE (-10.12±3.22%: P=0.039; -13.40±8.24%: P=0.028). After EE only the 1-hour value was improved (-5.03±5.48%: P=0.043). Acute IL-6 concentration rose significantly after CE but not after EE. We conclude that both a single bout of CE and a single bout of non-muscle-damaging EE elicit positive changes in glucose tolerance even in young, healthy subjects. Our experiment indicates that the overall metabolic cost is a major trigger for acute adaptations of glucose tolerance after exercise, but only the IL-6 production during EE was closely related to changes in glycaemic control. PMID:27274108

  4. Mitochondrial DNA copy number augments performance of A1C and oral glucose tolerance testing in the prediction of type 2 diabetes

    PubMed Central

    Cho, Seong Beom; Koh, InSong; Nam, Hye-Young; Jeon, Jae-Pil; Lee, Hong Kyu; Han, Bok-Ghee

    2017-01-01

    Here, we tested the performance of the mitochondrial DNA copy number (mtDNA-CN) in predicting future type 2 diabetes (n = 1108). We used the baseline clinical data (age, sex, body mass index, waist-to-hip ratio, systolic and diastolic blood pressure) and the mtDNA-CN, hemoglobin A1c (A1C) levels and results of oral glucose tolerance test (OGTT) including fasting plasma glucose, 1-hour glucose, and 2-hour glucose levels, to predict future diabetes. We built a prediction model using the baseline data and the diabetes status at biannual follow-up of 8 years. The mean area under curve (AUC) for all follow-ups of the full model including all variables was 0.92 ± 0.04 (mean ± standard deviation), while that of the model excluding the mtDNA-CN was 0.90 ± 0.03. The sensitivity of the f4ull model was much greater than that of the model not including mtDNA-CN: the mean sensitivities of the model with and without mtDNA-CN were 0.60 ± 0.06 and 0.53 ± 0.04, respectively. We found that the mtDNA-CN of peripheral leukocytes is a biomarker that augments the predictive power for future diabetes of A1C and OGTT. We believe that these results could provide invaluable information for developing strategies for the management of diabetes. PMID:28251996

  5. Glucose >200 mg/dL during Continuous Glucose Monitoring Identifies Adult Patients at Risk for Development of Cystic Fibrosis Related Diabetes

    PubMed Central

    Janssen, J. S.; Wilson, A.; Clair, C. G. St.; Pickard, K. M.; Jones, M. C.; Brayshaw, S. J.; Chacon, C. S.; Barboa, C. M.; Sontag, M. K.; Accurso, F. J.; Nichols, D. P.; Saavedra, M. T.; Nick, J. A.

    2016-01-01

    Rationale. Cystic fibrosis related diabetes (CFRD) is the most common comorbidity in patients with CF. In spite of increased screening, diagnosis, and treatment of CFRD, the mortality rate in patients with CFRD still far exceeds the mortality rate in those without CFRD. Guidelines suggest that screening for CFRD be performed annually using the 2-hour 75-gram oral glucose tolerance test (OGTT). Adherence to recommended screening has been poor, with only approximately one-quarter of adults with CF undergoing OGTT in 2014. Use of continuous glucose monitoring (CGM) for diagnosis may become an alternative. Objectives. Our objective was to determine whether abnormal CGM predicts subsequent development of CFRD, lung function, and body mass index (BMI) decline and increased rate of CF pulmonary exacerbations in adults with CF. Methods. In a prospective single center pilot trial from September 2009 to September 2010, 21 adult patients due for routine OGTT were recruited to complete simultaneous 3-day CGM and 2-hour 75 gram OGTT. Subsequently, clinical information was reviewed from 2008 to 2015. Conclusions. There was a moderate correlation between interpreted results of 2-hour OGTT and CGM (p = 0.03); CGM indicated a greater level of glucose impairment than OGTT. Glucose >200 mg/dL by CGM predicted development of CFRD (p = 0.0002). PMID:27999822

  6. New insulin sensitivity index from the oral glucose tolerance test.

    PubMed

    Kazama, Youichiro; Takamura, Toshinari; Sakurai, Masaru; Shindo, Hisakazu; Ohkubo, Eizho; Aida, Kaoru; Harii, Norikazu; Taki, Katsumi; Kaneshige, Masahiro; Tanaka, Shoichiro; Shimura, Hiroki; Endo, Toyoshi; Kobayashi, Tetsuro

    2008-01-01

    A new insulin sensitivity index was devised on the basis of an autoregressive model and its validity was investigated. Using data from the 75-g oral glucose tolerance test (OGTT), 115 subjects were divided into 3 groups: 40 with normal glucose tolerance, 34 with impaired glucose tolerance, and 41 with type 2 diabetes mellitus. The new insulin sensitivity index: oral glucose insulin sensitivity index (GSI) was calculated from five sets of plasma glucose and insulin levels obtained at 0, 30, 60, 90 and 120 min during OGTT using a formula based on an autoregressive model. Forty-three of the 115 subjects were examined for insulin sensitivity index (ISI) by euglycemic hyperinsulinemic clamp. GSI decreased in the order of normal glucose tolerance group>impaired glucose tolerance group>diabetic group. There was a significant correlation between GSI and the ISI derived from euglycemic hyperinsulinemic clamp study data in all 43 subjects who underwent both tests (r=0.72; P<0.0001). The ISI calculated by previous methods poorly correlated with the ISIs obtained by euglycemic hyperinsulinemic clamp study. In conclusion, this new insulin sensitivity index based on the data obtained from OGTT using an autoregressive model is comparable to an insulin sensitivity index by euglycemic hyperinsulinemic clamp technique and may be superior to previous indexes that have been devised to determine insulin sensitivity from OGTT data.

  7. Glucose tolerance in depressed inpatients, under treatment with mirtazapine and in healthy controls.

    PubMed

    Hennings, J M; Ising, M; Grautoff, S; Himmerich, H; Pollmächer, T; Schaaf, L

    2010-02-01

    Impaired glucose tolerance and diabetes have been associated with depression, and antidepressant treatment is assumed to improve impaired glucose tolerance. However, antidepressant treatment is also considered as a risk factor for the development of diabetes. Reports about glucose tolerance under antidepressant treatment frequently lack appropriate control groups. We conducted the oral glucose tolerance test (OGTT) in 10 healthy controls selected from an epidemiological sample with a negative lifetime history of mental Axis I disorder. Controls were carefully matched to a sample of inpatients with major depression that participated in an OGTT before and after antidepressant treatment with mirtazapine. All participants underwent a standard OGTT protocol. In patients, a second (after 2 weeks) and a third (after 4-6 weeks) OGTT was performed under treatment with mirtazapine. Compared to healthy controls, we observed significantly impaired glucose tolerance in acutely depressed patients. Effect size calculation indicated a moderate to large effects on glucose and insulin concentrations in response to an OGTT. Although glucose tolerance improved under mirtazapine treatment, insulin sensitivity was still impaired and remained significantly lower in patients compared to controls.

  8. Changes of the plasma metabolome during an oral glucose tolerance test: is there more than glucose to look at?

    PubMed

    Zhao, Xinjie; Peter, Andreas; Fritsche, Jens; Elcnerova, Michaela; Fritsche, Andreas; Häring, Hans-Ulrich; Schleicher, Erwin D; Xu, Guowang; Lehmann, Rainer

    2009-02-01

    The oral glucose tolerance test (oGTT) is a common tool to provoke a metabolic challenge for scientific purposes, as well as for diagnostic reasons, to monitor the kinetics of glucose and insulin. Here, we aimed to follow the variety of physiological changes of the whole metabolic pattern in plasma during an oGTT in healthy subjects in a nontargeted reversed-phase ultra performance liquid chromatography coupled to electrospray ionization quadrupole time of flight mass spectrometric metabolomics approach. We detected 11,500 metabolite ion masses/individual. Applying multivariate data analysis, four major groups of metabolites have been detected as the most discriminating oGTT biomarkers: free fatty acids (FFA), acylcarnitines, bile acids, and lysophosphatidylcholines. We found in detail 1) a strong decrease of all saturated and monounsaturated FFA studied during the oGTT; 2) a significant faster decline of palmitoleate (C16:1) and oleate (C18:1) FFA levels than their saturated counterparts; 3) a strong relative increase of polyunsaturated fatty acids in the fatty acid pattern at 120 min; and 4) a clear decrease in plasma C10:0, C12:0, and C14:1 acylcarnitine levels. These data reflect the switch from beta-oxidation to glycolysis and fat storage during the oGTT. Moreover, the bile acids glycocholic acid, glycochenodeoxycholic acid, and glycodeoxycholic acid were highly discriminative, showing a biphasic kinetic with a maximum of a 4.5- to 6-fold increase at 30 min after glucose ingestion, a significant decrease over the next 60 min followed by an increase until the end of the oGTT. Lysophosphatidylcholines were also increased significantly. The findings of our metabolomics study reveal detailed insights in the complex physiological regulation of the metabolism during an oGTT offering novel perspectives of this widely used procedure.

  9. Glucose tolerance and insulin response to glucose load in body builders.

    PubMed

    Szczypaczewska, M; Nazar, K; Kaciuba-Uscilko, H

    1989-02-01

    To find out to what extent body composition affects glucose tolerance, blood glucose (BG) and insulin (IRI) responses to a 100-g oral glucose tolerance test (OGTT) were compared in 10 male body builders, 11 untrained lean control subjects, and 11 mildly obese men, all of similar age (19-35 years). In comparison with the remaining two groups, the body builders had the lowest percentage of fat, although their lean body mass (LBM) in absolute terms did not differ from that in obese subjects. Both BG and IRI concentrations during the OGTT were the lowest in body builders, medium in controls, and the highest in obese men. The differences in glucose tolerance between the groups were also demonstrated by comparison of the subjects' BG levels during the OGTT with the respective mean BG values obtained in a reference group of 42 healthy nonobese men aged from 20 to 55 years. The data indicate that body builders show better glucose tolerance and improved insulin action in comparison with untrained, nonobese subjects of similar age and body weight. Lean body mass in absolute terms cannot, however, be considered as a sole determinant of the insulin action in the body since in mildly obese subjects glucose tolerance was considerably reduced in spite of the fact that their LBM was similar to that in body builders. Either muscle hypertrophy or reduced adiposity may account for the beneficial effects of body building on glucose metabolism.

  10. Guidance for 1-Hour Sulfur Dioxide (SO2) Nonattainment Area State Implementation Plans (SIP) Submissions

    EPA Pesticide Factsheets

    The document is intended to provide guidance and recommendations to state, local and tribal governments for the development of SIPs and tribal implementation plans (TIPs) under the 2010 1-hour primary NAAQS for Sulfur Dioxide (SO2).

  11. Opuntia ficus-indica ingestion stimulates peripheral disposal of oral glucose before and after exercise in healthy men.

    PubMed

    Van Proeyen, Karen; Ramaekers, Monique; Pischel, Ivo; Hespel, Peter

    2012-08-01

    The purpose of this study was to investigate the effect of Opuntia ficus-indica (OFI) cladode and fruit-skin extract on blood glucose and plasma insulin increments due to high-dose carbohydrate ingestion, before and after exercise. Healthy, physically active men (n = 6; 21.0 ± 1.6 years, 78.1 ± 6.0 kg) participated in a double-blind placebo-controlled crossover study involving 2 experimental sessions. In each session, the subjects successively underwent an oral glucose tolerance test at rest (OGTT(R)), a 30-min cycling bout at ~75% VO(2max), and another OGTT after exercise (OGTT(EX)). They received capsules containing either 1,000 mg OFI or placebo (PL) 30 min before and immediately after the OGTT(R). Blood samples were collected before (t₀) and at 30-min intervals after ingestion of 75 g glucose for determination of blood glucose and serum insulin. In OGTT(EX) an additional 75-g oral glucose bolus was administered at t₆₀. In OGTT(R), OFI administration reduced the area under the glucose curve (AUC(GLUC)) by 26%, mainly due to lower blood glucose levels at t₃₀ and t₆₀ (p < .05). Furthermore, a higher serum insulin concentration was noted after OFI intake at baseline and at t₃₀ (p < .05). In OGTT(EX), blood glucose at t₆₀ was ~10% lower in OFI than in PL, which resulted in a decreased AUC(GLUC) (-37%, p < .05). However, insulin values and AUC(INS) were not different between OFI and PL. In conclusion, the current study shows that OFI extract can increase plasma insulin and thereby facilitate the clearance of an oral glucose load from the circulation at rest and after endurance exercise in healthy men.

  12. The Effect of Carvedilol on Blood Glucose Levels In Normal Albino Rats

    PubMed Central

    R.N., Suresha; V., Ashwini; B., Pragathi; H.L., Kalabharathi; A.M., Satish; V.H., Pushpa; M.K., Jayanthi; P., Snehalatha

    2013-01-01

    Background: Carvedilol is a commonly used drug in hypertension, congestive heart failure in diabetics. It has moderate calcium channel blocking property in addition to α1 and non selective β antagonistic activity. Though some studies bring forth the beneficial effects of Carvedilol in cardiovascular comorbidities in diabetes, there is no consensus on its effects on glycaemic levels. Aims: To evaluate the effect of oral Carvedilol administration for 5 days on blood glucose levels in normal albino rats through Oral Glucose Tolerance Test. Material and Methods: Twelve adult albino rats of either sex weighing between 150 – 200 g were selected from central animal facility and randomly divided into 2 groups – Control [Distilled water (1ml/rat orally)] and Test (0.8mg/kg body weight orally) and the respective drugs were administered over 5 days. Following overnight fasting, on the fifth day 1 hour after the last dose of the respective drug, OGTT was performed. The CBG (Capillary Blood Glucose) levels were measured at 0 min, glucose (2g/kg body weight) dissolved in water was administered to all the rats orally. The blood sample from tail vein (obtained by tail snipping) at 60 and 150 minutes were analysed for CBG levels using a standardized glucometer. Statistical Analysis: Data was presented as Mean ± SEM. One way ANOVA, independent samples t-test, non–parametric tests, percentages and cross tabs were used in the analysis of data within the same group and between different groups when required. Results: Carvedilol group showed higher CBG levels at all time intervals of OGTT as compared to the Control group i.e., 0, 60 and 150 minutes, the highest being (103.8±5.029 )mg/dl at 60 minutes and was statistically significant. Carvedilol group however showed lesser inter–interval variation compared to the Control group at the same time intervals respectively but was statistically insignificant. Conclusions: Carvedilol has hyperglycaemic potential when given orally

  13. Mathematical modeling on experimental protocol of glucose adjustment for non-invasive blood glucose sensing

    NASA Astrophysics Data System (ADS)

    Jiang, Jingying; Min, Xiaolin; Zou, Da; Xu, Kexin

    2012-03-01

    Currently, blood glucose concentration levels from OGTT(Oral Glucose Tolerance Test) results are used to build PLS model in noninvasive blood glucose sensing by Near-Infrared(NIR) Spectroscopy. However, the univocal dynamic change trend of blood glucose concentration based on OGTT results is not various enough to provide comprehensive data to make PLS model robust and accurate. In this talk, with the final purpose of improving the stability and accuracy of the PLS model, we introduced an integrated minimal model(IMM) of glucose metabolism system. First, by adjusting parameters, which represent different metabolism characteristics and individual differences, comparatively ideal mediation programs to different groups of people, even individuals were customized. Second, with different glucose input types(oral method, intravenous injection, or intravenous drip), we got various changes of blood glucose concentration. And by studying the adjustment methods of blood glucose concentration, we would thus customize corresponding experimental protocols of glucose adjustment to different people for noninvasive blood glucose concentration and supply comprehensive data for PLS model.

  14. Difference between 2 h and 3 h 75 g glucose tolerance test in the diagnosis of gestational diabetes mellitus (GDM): results from a national survey on prevalence of GDM.

    PubMed

    Gao, Xue-Lian; Wei, Yu-Mei; Yang, Hui-Xia; Xu, Xian-Ming; Fan, Ling; He, Jing; Liu, Ning; Zhao, San-Cun; Hu, Ya-Li; Yang, Zi; Zhang, Yun-Ping; Liu, Xing-Hui; Chen, Xu; Zhang, Jian-Ping; Gou, Wen-Li; Xiao, Mei; Wu, Hai-Rong; Zhang, Mei-Hua

    2010-09-01

    The possibility of the 2 h oral glucose tolerance test (OGTT) as an alternative to the 3 h OGTT was investigated based on data from a national survey on pregnancy-associated diabetes. Data were retrieved from 4179 pregnant women who had OGTT performed after an abnormal 50 g glucose challenge test (GCT). All of the 4 glucose levels during their OGTT were collected and analyzed. According to American Diabetes Association (ADA) gestational diabetes mellitus (GDM) diagnostic criteria, among the 4179 pregnant women who required OGTT, 3429 (82.1%) were normal and 750 (17.9%) were diagnosed as GDM. If the 3rd h glucose levels were omitted from OGTT, 79 cases of GDM (10.5%) would be overlooked. No trend was shown where women with more risk factors were more likely to be overlooked if the 3rd h test was omitted (χ2 for trend=0.038, P>0.05). No significant differences were found in the rate of cesarean section (CS), preterm births or macrosomia between the 79 cases and those with normal OGTT results and in the gestational weeks when OGTT was performed. It shows that in order to diagnose one woman with GDM, another 52 pregnant women would have an innocent 3rd h glucose test. Omission of the 3rd h glucose test in OGTT might be reasonable due to its convenience, better compliance and a small number of possibly miss-diagnosed cases, and their pregnancy outcomes have no significant difference from those of normal pregnant women.

  15. Effect of acacia polyphenol on glucose homeostasis in subjects with impaired glucose tolerance: A randomized multicenter feeding trial

    PubMed Central

    OGAWA, SOSUKE; MATSUMAE, TOMOYUKI; KATAOKA, TAKESHI; YAZAKI, YOSHIKAZU; YAMAGUCHI, HIDEYO

    2013-01-01

    Numerous in vitro and animal studies, as well as clinical trials have indicated that plant-derived polyphenols exert beneficial effects on glucose intolerance or type 2 diabetes. This clinical study aimed to investigate the effects of acacia polyphenol (AP) on glucose and insulin responses to an oral glucose tolerance test (OGTT) in non-diabetic subjects with impaired glucose tolerance (IGT). A randomized, double-blind, placebo-controlled trial was conducted in a total of 34 enrolled subjects. The subjects were randomly assigned to the AP-containing dietary supplement (AP supplement; in a daily dose of 250 mg as AP; n=17) or placebo (n=17) and the intervention was continued for 8 weeks. Prior to the start of the intervention (baseline) and after 4 and 8 weeks of intervention, plasma glucose and insulin were measured during a two-hour OGTT. Compared with the baseline, plasma glucose and insulin levels at 90 and/or 120 min, as well as the total area under the curve values during the OGTT (AUC0→2h) for glucose and insulin, were significantly reduced in the AP group, but not in the placebo group after intervention for 8 weeks. The decline from baseline in plasma glucose and insulin at 90 or 120 min of the OGTT for the AP group was significantly greater compared with that of the placebo group after 8 weeks of intervention. No AP supplement-related adverse side-effects nor any abnormal changes in routine laboratory tests and anthropometric parameters were observed throughout the study period. The AP supplement may have the potential to improve glucose homeostasis in subjects with IGT. PMID:23837032

  16. Continuous glucose monitoring, oral glucose tolerance, and insulin - glucose parameters in adolescents with simple obesity.

    PubMed

    El Awwa, A; Soliman, A; Al-Ali, M; Yassin, M; De Sanctis, V

    2012-09-01

    In obese adolescents pancreatic beta-cells may not be able to cope with insulin resistance leading to hyperglycemia and type2 diabetes (T2DM To assess oral glucose tolerance, 72-h continuous blood glucose concentrations (CGM) and calculate homeostatic model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI) in 13 adolescents with simple obesity (BMI SDS=4 ± 1.06). OGTT performed in 13 obese adolescents (13.47 ± 3 years) revealed 3 cases (23%) with impaired fasting glucose (IFG: fasting glucose >5.6 mmol/L), 4 cases (30%) with impaired glucose tolerance (IGT: 2h blood glucose >7.8 <11.1 mmol/L), and none with diabetes. Using the continuous glucose monitoring system ( CGMS), IFG was detected in 4 cases, the maximum serum blood glucose (BG : 2h or more after meal) was >7.8 and <11.1 mmol/L (IGT) in 9 children (69%) and >11.1 mmol/L (diabetes) in one case (7.6%). Five cases had a minimum BG recorded of <2.7 mmol/L (hypoglycemia). No glycemic abnormality was detected using HbA1C (5.7 ± 0.3%). 11/13 patients had HOMA values >2.6 and QUICKI values <0.35 denoting insulin resistance. Beta cell mass percent (B %) = 200 ± 94.8% and insulin sensitivity values (IS)=50.4 ± 45.5% denoted insulin resistance with hyper-insulinaemia and preserved beta cell mass. In obese adolescents, CGMS is superior to OGTT and HbA1C in detecting glycemic abnormalities, which appears to be secondary to insulin resistance.

  17. Serum Galanin Levels in Young Healthy Lean and Obese Non-Diabetic Men during an Oral Glucose Tolerance Test

    PubMed Central

    Sandoval-Alzate, Héctor Fabio; Agudelo-Zapata, Yessica; González-Clavijo, Angélica María; Poveda, Natalia E.; Espinel-Pachón, Cristian Felipe; Escamilla-Castro, Jorge Augusto; Márquez-Julio, Heidy Lorena; Alvarado-Quintero, Hernando; Rojas-Rodríguez, Fabián Guillermo; Arteaga-Díaz, Juan Manuel; Eslava-Schmalbach, Javier Hernando; Garcés-Gutiérrez, Maria Fernanda; Vrontakis, Maria; Castaño, Justo P.; Luque, Raul M.; Diéguez, Carlos; Nogueiras, Rubén; Caminos, Jorge E.

    2016-01-01

    Galanin (GAL) is a neuropeptide involved in the homeostasis of energy metabolism. The objective of this study was to investigate the serum levels of GAL during an oral glucose tolerance test (OGTT) in lean and obese young men. This cross-sectional study included 30 obese non-diabetic young men (median 22 years; mean BMI 37 kg/m2) and 30 healthy lean men (median 23 years; mean BMI 22 kg/m2). Serum GAL was determined during OGTT. The results of this study include that serum GAL levels showed a reduction during OGTT compared with basal levels in the lean subjects group. Conversely, serum GAL levels increased significantly during OGTT in obese subjects. Serum GAL levels were also higher in obese non-diabetic men compared with lean subjects during fasting and in every period of the OGTT (p < 0.001). Serum GAL levels were positively correlated with BMI, total fat, visceral fat, HOMA–IR, total cholesterol, triglycerides and Leptin. A multiple regression analysis revealed that serum insulin levels at 30, 60 and 120 minutes during the OGTT is the most predictive variable for serum GAL levels (p < 0.001). In conclusion, serum GAL levels are significantly higher in the obese group compared with lean subjects during an OGTT. PMID:27550417

  18. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols.

  19. Pregnane X receptor agonists impair postprandial glucose tolerance.

    PubMed

    Rysä, J; Buler, M; Savolainen, M J; Ruskoaho, H; Hakkola, J; Hukkanen, J

    2013-06-01

    We conducted a randomized, open, placebo-controlled crossover trial to investigate the effects of the pregnane X receptor (PXR) agonist rifampin on an oral glucose tolerance test (OGTT) in 12 healthy volunteers. The subjects were administered 600 mg rifampin or placebo once daily for 7 days, and OGTT was performed on the eighth day. The mean incremental glucose and insulin areas under the plasma concentration-time curves (AUC(incr)) increased by 192% (P = 0.008) and 45% (P = 0.031), respectively. The fasting glucose, insulin, and C-peptide, and the homeostasis model assessment for insulin resistance, were not affected. The glucose AUC(incr) during OGTT was significantly increased in rats after 4-day treatment with pregnenolone 16α-carbonitrile (PCN), an agonist of the rat PXR. The hepatic level of glucose transporter 2 (Glut2) mRNA was downregulated by PCN. In conclusion, both human and rat PXR agonists elicited postprandial hyperglycemia, suggesting a detrimental role of PXR activation on glucose tolerance.

  20. Blood glucose prediction using neural network

    NASA Astrophysics Data System (ADS)

    Soh, Chit Siang; Zhang, Xiqin; Chen, Jianhong; Raveendran, P.; Soh, Phey Hong; Yeo, Joon Hock

    2008-02-01

    We used neural network for blood glucose level determination in this study. The data set used in this study was collected using a non-invasive blood glucose monitoring system with six laser diodes, each laser diode operating at distinct near infrared wavelength between 1500nm and 1800nm. The neural network is specifically used to determine blood glucose level of one individual who participated in an oral glucose tolerance test (OGTT) session. Partial least squares regression is also used for blood glucose level determination for the purpose of comparison with the neural network model. The neural network model performs better in the prediction of blood glucose level as compared with the partial least squares model.

  1. Ceylon cinnamon does not affect postprandial plasma glucose or insulin in subjects with impaired glucose tolerance.

    PubMed

    Wickenberg, Jennie; Lindstedt, Sandra; Berntorp, Kerstin; Nilsson, Jan; Hlebowicz, Joanna

    2012-06-01

    Previous studies on healthy subjects have shown that the intake of 6 g Cinnamomum cassia reduces postprandial glucose and that the intake of 3 g C. cassia reduces insulin response, without affecting postprandial glucose concentrations. Coumarin, which may damage the liver, is present in C. cassia, but not in Cinnamomum zeylanicum. The aim of the present study was to study the effect of C. zeylanicum on postprandial concentrations of plasma glucose, insulin, glycaemic index (GI) and insulinaemic index (GII) in subjects with impaired glucose tolerance (IGT). A total of ten subjects with IGT were assessed in a crossover trial. A standard 75 g oral glucose tolerance test (OGTT) was administered together with placebo or C. zeylanicum capsules. Finger-prick capillary blood samples were taken for glucose measurements and venous blood for insulin measurements, before and at 15, 30, 45, 60, 90, 120, 150 and 180 min after the start of the OGTT. The ingestion of 6 g C. zeylanicum had no significant effect on glucose level, insulin response, GI or GII. Ingestion of C. zeylanicum does not affect postprandial plasma glucose or insulin levels in human subjects. The Federal Institute for Risk Assessment in Europe has suggested the replacement of C. cassia by C. zeylanicum or the use of aqueous extracts of C. cassia to lower coumarin exposure. However, the positive effects seen with C. cassia in subjects with poor glycaemic control would then be lost.

  2. Validation of Point-of-Care Glucose Testing for Diagnosis of Type 2 Diabetes.

    PubMed

    Vučić Lovrenčić, Marijana; Radišić Biljak, Vanja; Božičević, Sandra; Pape-Medvidović, Edita; Ljubić, Spomenka

    2013-01-01

    Point-of-care (POC) glucose technology is currently considered to be insufficiently accurate for the diagnosis of diabetes. The objective of this study was to investigate the diagnostic accuracy of an innovative, interference-resistant POC glucose meter (StatStrip glucose hospital meter, Nova Biomedical, USA) in subjects with a previous history of dysglycaemia, undergoing a 75 g diagnostic oral glucose tolerance test (oGTT). Venous and capillary blood sampling for the reference laboratory procedure (RLP) and POC-glucose measurement was carried out at fasting and 2 h oGTT, and categories of glucose tolerance were classified according to 2006 WHO diagnostic criteria for the respective sample type. We found an excellent between-method correlation at fasting (r = 0.9681, P < 0.0001) and 2 h oGTT (r = 0.9768, P < 0.0001) and an almost perfect diagnostic agreement (weighted Kappa = 0.858). Within a total of 237 study subjects, 137 were diagnosed with diabetes with RLP, and only 6 of them were reclassified as having glucose intolerance with POC. The diagnostic performance of POC-fasting glucose in discriminating between the normal and any category of disturbed glucose tolerance did not differ from the RLP (P = 0.081). Results of this study indicate that StatStrip POC glucose meter could serve as a reliable tool for the diabetes diagnosis, particularly in primary healthcare facilities with dispersed blood sampling services.

  3. Serum high-molecular weight adiponectin decreases abruptly after an oral glucose load in subjects with normal glucose tolerance or impaired fasting glucose, but not those with impaired glucose tolerance or diabetes mellitus.

    PubMed

    Ozeki, Noriyuki; Hara, Kenji; Yatsuka, Chikako; Nakano, Tomoki; Matsumoto, Sachiko; Suetsugu, Mariko; Nakamachi, Takafumi; Takebayashi, Kohzo; Inukai, Toshihiko; Haruki, Kohsuke; Aso, Yoshimasa

    2009-10-01

    Adiponectin exists in the blood as 3 forms, which are a trimer, a hexamer, and a high-molecular weight (HMW) form. We investigated whether circulating HMW adiponectin levels were altered by oral glucose or fat ingestion. Forty male subjects underwent a 75-g oral glucose loading test (OGTT), and 11 healthy subjects (5 women and 6 men) received a fat loading test. Serum levels of HMW and total adiponectin were measured during the OGTT and the fat loading test. The fat loading test was performed for at least 8 hours. Among the 40 male subjects, 11 had normal glucose tolerance (NGT), 9 had impaired fasting glucose (IFG), 11 had impaired glucose tolerance, and 9 had diabetes mellitus (DM). In all 40 subjects, the serum total adiponectin level did not change significantly, whereas serum HMW adiponectin decreased significantly after a glucose load and reached 92.2% of the basal level at 120 minutes after the OGTT (P < .01). The HMW to total adiponectin ratio decreased significantly from 0.47 +/- 0.15 at baseline to 0.43 +/- 0.13 at 120 minutes after a glucose load (P < .05). Serum HMW adiponectin measured at 120 minutes after the OGTT decreased significantly to 86.0% and 85.6% of the basal level in subjects with NGT or IFG, respectively (both P < .01). In subjects with impaired glucose tolerance or DM, however, serum HMW adiponectin did not change. The area under the curve for insulin at 30 minutes after a glucose load during the OGTT was significantly larger in subjects with NGT or IFG than in those with DM (P < .05). In addition, the insulinogenic index (DeltaI(0-30)/DeltaG(0-30)) was significantly higher in subjects with NGT or IFG than in those with DM (P < .001). Percentage changes in serum HMW adiponectin of the baseline at 120 minutes correlated negatively with those in serum insulin (r = -0.468, P = .0023), but not plasma glucose, of the baseline at 30 minutes in 40 subjects. On the other hand, serum triglycerides increased significantly after an oral fat load in

  4. Exenatide Regulates Cerebral Glucose Metabolism in Brain Areas Associated With Glucose Homeostasis and Reward System.

    PubMed

    Daniele, Giuseppe; Iozzo, Patricia; Molina-Carrion, Marjorie; Lancaster, Jack; Ciociaro, Demetrio; Cersosimo, Eugenio; Tripathy, Devjit; Triplitt, Curtis; Fox, Peter; Musi, Nicolas; DeFronzo, Ralph; Gastaldelli, Amalia

    2015-10-01

    Glucagon-like peptide 1 receptors (GLP-1Rs) have been found in the brain, but whether GLP-1R agonists (GLP-1RAs) influence brain glucose metabolism is currently unknown. The study aim was to evaluate the effects of a single injection of the GLP-1RA exenatide on cerebral and peripheral glucose metabolism in response to a glucose load. In 15 male subjects with HbA1c of 5.7 ± 0.1%, fasting glucose of 114 ± 3 mg/dL, and 2-h glucose of 177 ± 11 mg/dL, exenatide (5 μg) or placebo was injected in double-blind, randomized fashion subcutaneously 30 min before an oral glucose tolerance test (OGTT). The cerebral glucose metabolic rate (CMRglu) was measured by positron emission tomography after an injection of [(18)F]2-fluoro-2-deoxy-d-glucose before the OGTT, and the rate of glucose absorption (RaO) and disposal was assessed using stable isotope tracers. Exenatide reduced RaO0-60 min (4.6 ± 1.4 vs. 13.1 ± 1.7 μmol/min ⋅ kg) and decreased the rise in mean glucose0-60 min (107 ± 6 vs. 138 ± 8 mg/dL) and insulin0-60 min (17.3 ± 3.1 vs. 24.7 ± 3.8 mU/L). Exenatide increased CMRglu in areas of the brain related to glucose homeostasis, appetite, and food reward, despite lower plasma insulin concentrations, but reduced glucose uptake in the hypothalamus. Decreased RaO0-60 min after exenatide was inversely correlated to CMRglu. In conclusion, these results demonstrate, for the first time in man, a major effect of a GLP-1RA on regulation of brain glucose metabolism in the absorptive state.

  5. Acute effects of aerobic exercise intensity on arterial stiffness after glucose ingestion in young men.

    PubMed

    Kobayashi, Ryota; Hashimoto, Yuto; Hatakeyama, Hiroyuki; Okamoto, Takanobu

    2016-10-18

    Arterial stiffness increases after glucose ingestion. Acute low- and moderate-intensity aerobic exercise decreases arterial stiffness. However, the acute effects of 30 min of cycling at low- and moderate-intensity [25% (LE trial) and 65% (ME trial) peak oxygen uptake, respectively] on arterial stiffness at 30, 60 and 120 min of a postexercise glucose ingestion. Ten healthy young men (age, 22·4 ± 0·5 years) performed LE and ME trials on separate days in a randomized controlled crossover fashion. Carotid-femoral (aortic) pulse wave velocity (PWV), femoral-ankle (leg) PWV, carotid augmentation index (AIx) and carotid blood pressure (BP) (applanation tonometry), brachial and ankle BP (oscillometric device), heart rate (HR) (electrocardiography), blood glucose (UV-hexokinase method) and blood insulin (CLEIA method) levels were measured at before (baseline) and at 30, 60 and 120 min after the 75-g OGTT. Leg PWV, ankle pulse pressure and BG levels significantly increased from baseline after the 75-g OGTT in the LE trial (P<0·05), but not in the ME trial. Insulin levels and HR significantly increased from baseline after the 75-g OGTT in both trials (P<0·05). Aortic PWV, carotid AIx, brachial BP and carotid BP did not change from baseline after the 75-g OGTT in both trials. The present findings indicate that aerobic exercise at moderate intensity before glucose ingestion suppresses increases leg arterial stiffness after glucose ingestion.

  6. Imparied glucose tolerance in long-term lithium-treated patients.

    PubMed

    Müller-Oerlinghausen, B; Passoth, P M; Poser, W; Pudel, V

    1979-01-01

    The oral glucose tolerance test (oGTT) was performed twice in patients under long-term lithium treatment. Blood glucose and plasma insulin were determined. The oGTT results were evaluated by three criteria (Köbberling-Creutzfeldt, WHO, and Epidemiological Study Group of the European Diabetes Association) and were compared to two representative reference studies from normal populations. The frequency of impaired glucose tolerance in the patients was three times higher than expected on the basis of the studies on normal populations. The variability of the oGTT curves between the first and second tests as well as the steepness of the time-course of the 'insulinogenic index' suggested mild disturbances of carbohydrate metabolism (mild diabetes) in some of the patients. It is considered unlikely that the impairment of glucose tolerance in the patients was a direct pharmacological effect of lithium salts. The possible role of age, sex, manic-depressive disease, additional medication, and particularly obesity in the effects of long-term lithium treatment on glucose tolerance is discussed. The authors suggest that the oGTT should be carried out periodically in long-term, lithium-treated patients over the age of 40 years in order to detect abnormalities in their carbohydrate metabolism.

  7. 77 FR 4940 - Determination of Failure To Attain by 2005 and Determination of Current Attainment of the 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    .... EPA, 375 F.3d 537(7th Cir. 2004) and Our Children's Earth Foundation v. EPA, No. 04-73032 (9thCir... monitored attainment of the 1-hour ozone NAAQS. EPA's review shows that the area has attained the 1-hour..., Associate Director, Office of Air Program Planning, Mailcode 3AP30, U.S. Environmental Protection...

  8. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  9. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  10. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  11. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  12. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  13. Improved tolerance to sequential glucose loading (Staub-Traugott effect): size and mechanisms.

    PubMed

    Bonuccelli, Sandra; Muscelli, Elza; Gastaldelli, Amalia; Barsotti, Elisabetta; Astiarraga, Brenno D; Holst, Jens J; Mari, Andrea; Ferrannini, Ele

    2009-08-01

    Improved glucose tolerance to sequential glucose loading (Staub-Traugott effect) is an important determinant of day-to-day glycemic exposure. Its mechanisms have not been clearly established. We recruited 17 healthy volunteers to receive two sequential oral glucose tolerance tests (OGTTs), at time 0 min and 180 min (Study I). The protocol was repeated on a separate day (Study II) except that plasma glucose was clamped at 8.3 mmol/l between 60 and 180 min. beta-Cell function was analyzed by mathematical modeling of C-peptide concentrations. In a subgroup, glucose kinetics were measured by a triple-tracer technique (infusion of [6,6-(2)H(2)]glucose and labeling of the 2 glucose loads with [1-(2)H]glucose and [U-(13)C]glucose). In both Studies I and II, the plasma glucose response to the second OGTT equaled 84 +/- 2% (P = 0.003) of the response to the first OGTT. Absolute insulin secretion was lower (37.8 +/- 4.3 vs. 42.8 +/- 5.1 nmol/m(2), P = 0.02), but glucose potentiation (i.e., higher secretion at the same glycemia) was stronger (1.08 +/- 0.02- vs. 0.92 +/- 0.02-fold, P = 0.006), the increment being higher in Study II (+36 +/- 5%) than Study I (+19 +/- 6%, P < 0.05). In pooled data, a higher glucose area during the first OGTT was associated with a higher potentiation during the second OGTT (rho=0.60, P = 0.002). Neither insulin clearance nor glucose clearance differed between loads, and appearance of glucose over 3 h totalled 60 +/- 6 g for the first load and 52 +/- 5 g for the second load (P = not significant). Fasting endogenous glucose production [13.3 +/- 0.6 micromol x min(-1) x kg fat-free mass (FFM)(-1)] averaged 6.0 +/- 3.8 micromol x min(-1) x kg FFM(-1) between 0 and 180 min and 1.7 +/- 2.6 between 180 and 360 min (P < 0.03). Glucose potentiation and stronger suppression of endogenous glucose release are the main mechanisms underlying the Staub-Traugott effect.

  14. Setting Spacecraft Maximum Allowable Concentrations for 1 hour or 24 hour contingency exposures to airborne chemicals

    NASA Technical Reports Server (NTRS)

    Garcia, Hector D.; Limero, Thomas F.; James, John T.

    1992-01-01

    Since the early years of the manned space program, NASA has developed and used exposure limits called Spacecraft Maximum Allowable Concentrations (SMACs) to help protect astronauts from airborne toxicants. Most of these SMACS are based on an exposure duration of 7 days, since this is the duration of a 'typical' mission. A set of 'contingency SMACs' is also being developed for scenarios involving brief (1-hour or 24- hour) exposures to relatively high levels of airborne toxicants from event-related 'contingency' releases of contaminants. The emergency nature of contingency exposures dictates the use of different criteria for setting exposure limits. The NASA JSC Toxicology Group recently began a program to document the rationales used to set new SMACs and plans to review the older, 7-day SMACs. In cooperation with the National Research Council's Committee on Toxicology, a standard procedure has been developed for researching, setting, and documenting SMAC values.

  15. Intestinal transit of a glucose bolus and incretin kinetics: a mathematical model with application to the oral glucose tolerance test.

    PubMed

    Salinari, Serenella; Bertuzzi, Alessandro; Mingrone, Geltrude

    2011-06-01

    The rate of appearance (R(a)) of exogenous glucose in plasma after glucose ingestion is presently measured by tracer techniques that cannot be used in standard clinical testing such as the oral glucose tolerance test (OGTT). We propose a mathematical model that represents in a simple way the gastric emptying, the transport of glucose along the intestinal tract, and its absorption from gut lumen into portal blood. The model gives the R(a) time course in terms of parameters with a physiological counterpart and provides an expression for the release of incretin hormones as related to glucose transit into gut lumen. Glucose absorption was represented by assuming two components related to a proximal and a distal transporter. Model performance was evaluated by numerical simulations. The model was then validated by fitting OGTT glucose and GLP-1 data in healthy controls and type 2 diabetic patients, and useful information was obtained for the rate of gastric emptying, the rate of glucose absorption, the R(a) profile, the insulin sensitivity, and the glucose effectiveness. Model-derived estimates of insulin sensitivity were well correlated (r = 0.929 in controls and 0.886 in diabetic patients) to data obtained from the euglycemic hyperinsulinemic clamp. Although the proposed OGTT analysis requires the measurement of an additional hormone concentration (GLP-1), it appears to be a reasonable choice since it avoids complex and expensive techniques, such as isotopes for glucose R(a) measurement and direct assessment of gastric emptying and intestinal transit, and gives additional correlated information, thus largely compensating for the extra expense.

  16. Effects of an oral glucose tolerance test on the myogenic response in healthy individuals.

    PubMed

    Lott, Mary E J; Hogeman, Cynthia; Herr, Michael; Gabbay, Robert; Sinoway, Lawrence I

    2007-01-01

    The myogenic response, the inherent ability of blood vessels to rapidly respond to changes in transmural pressure, is involved in local blood flow autoregulation. Animal studies suggest that both acute hyperglycemia and hyperinsulinemia may impair myogenic vasoconstriction. The purpose of this study was to examine the effects of an oral glucose load on brachial mean blood velocity (MBV) during increases in forearm transmural pressure in humans. Eight healthy men and women (38 +/- 5 yr) underwent an oral glucose tolerance test (OGTT). MBV (in cm/s; Doppler ultrasound) responses to a rise in forearm transmural pressure (arm tank suction, -50 mmHg) were studied before and every 30 min for 120 min during the OGTT. Before the start of the OGTT, MBV was lower than baseline values 30 and 60 s after the application of negative pressure. This suggests that myogenic constriction was present. During the OGTT, blood glucose rose from 88 +/- 2 to 120 +/- 6 mg/dl (P < 0.05) and insulin rose from 14 +/- 1 to 101 +/- 32 microU/ml (P < 0.05). Glucose loading attenuated the reduction in MBV with arm suction (Delta-0.73 +/- 0.14 vs. Delta-1.67 +/- 0.43 cm/s and Delta-1.07 +/- 0.14 vs. Delta-2.38 +/- 0.54 cm/s, respectively, during 30 and 60 s of suction postglucose compared with preglucose values; all P < 0.05). We observed no such time effect for myogenic responses during a sham OGTT. In an additional 5 subjects, glucose loading had no effect on brachial diameters with the application of negative pressure. Oral glucose loading leads to attenuated myogenic vasoconstriction in healthy individuals. The role that this diminished postglucose reactivity plays in mediating postprandial hypotension and/or orthostasis needs to be further explored.

  17. Beta-cell function, incretin effect, and incretin hormones in obese youth along the span of glucose tolerance from normal to prediabetes to Type 2 diabetes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using the hyperglycemic and euglycemic clamp, we demonstrated impaired Beta-cell function in obese youth with increasing dysglycemia. Herein we describe oral glucose tolerance test (OGTT)-modeled Beta-cell function and incretin effect in obese adolescents spanning the range of glucose tolerance. Bet...

  18. Glucose and insulin tolerance throughout the menstrual cycle.

    PubMed

    Fioretti, P; Genazzani, A R; Felber, J P; Facchini, V; Onano, A M; Romagnino, S; Facchinetti, F; Piras, G L

    1975-03-01

    On the basis of the behaviour during menstrual cycle of the pituitary hormones plasma levels, the Authors have studied during the different periods of the cycle (follicular, ovulatory and luteal) the effects of OGTT and ITT's on the plasma levels of Glucose, insulin, HGH and Cortisol. Significantly lower levels of IRI, HGH and Cortisol were found in follicular phase compared to ovulatory period and luteal phase except for Cortisol in luteal phase. A slightly higher glucose tolerance was found in follicular phase as well as a reduced hypoglicemia under insulin load. Reduced HGH response to ITT was found in follicular phase as well as a reduced Cortisol response compared to the results observed in ovulatory and luteal phase. These data sustain the concept that hormonal variations occurring in an ovulatory cycle are also capable of modifying the woman's body response to various stimuli such as OGTT and ITT.

  19. Pre-Type 1 Diabetes Dysmetabolism: Maximal sensitivity achieved with Both Oral and Intravenous Glucose Tolerance Testing

    PubMed Central

    Barker, Jennifer M.; McFann, Kim; Harrison, Leonard C.; Fourlanos, Spiros; Krischer, Jeffrey; Cuthbertson, David; Chase, H. Peter; Eisenbarth, George S.; Group, the DPT-1 Study

    2007-01-01

    Objective To determine the relationship of intravenous (IVGTT) and oral (OGTT) glucose tolerance tests abnormalities to diabetes development in a high-risk pre-diabetic cohort and identify an optimal testing strategy for detecting pre-clinical diabetes. Study design Diabetes Prevention Trial Type 1 randomized subjects to oral (n=372) and parenteral (n=339) insulin prevention trials. Subjects were followed with IVGTTs and OGTTs. Factors associated with progression to diabetes were evaluated. Results Survival analysis revealed that higher quartiles of 2-hour glucose and lower quartiles of FPIR at baseline were associated with decreased diabetes-free survival. Cox proportional hazards modeling showed that baseline BMI, FPIR and 2-hour glucose levels were significantly associated with an increased hazard for diabetes. On testing performed within 6 months of diabetes diagnosis, 3% (1/32) had normal first phase insulin response (FPIR) and normal 2-hour glucose on OGTT. The sensitivities for impaired glucose tolerance (IGT) and low FPIR performed within 6 months of diabetes diagnosis were equivalent (76% vs. 73%). Conclusions Most (97%) subjects had abnormal IVGTTs and/or OGTTs prior to the development of diabetes. The highest sensitivity is achieved using both tests. PMID:17188609

  20. Oral glucose tolerance test for preoperative assessment of liver function in liver resection

    PubMed Central

    Rachapoodivenkata, Raghavendra Rao

    2017-01-01

    Backgrounds/Aims We intended to determine the role of the Oral glucose tolerance test (OGTT), in addition to volumetry, in preoperative assessment of patients undergoing liver resection. Methods This was a prospective study conducted at a tertiary care hospital, between February 2009 and February 2011. OGTT curve (parabolic/linear), linearity index (LI) and Parenchymal Hepatic Resection Rate (PHRR) were correlated with postoperative outcomes in terms of postoperative liver failure (PLF), by 50-50 criteria, morbidity, mortality and hospital stay. Results Of the 33 patients included in the study, 23 (69.7%) patients underwent major liver resections. Hepatocellular carcinoma (30.3%) was the leading indication. The overall postoperative morbidity rate was 72.7%, but major complications occurred in 3 (9.1%) patients only. There was no 90-day mortality. The 50-50 criteria were met by 3 patients undergoing major resection. Significant correlation was noted between the linear OGTT curve and the overall hospital stay (12.1 days vs. 9.6 days in parabolic; p=0.04). Patients with linear OGTT met the 50-50 criteria more often (18%) than those having a parabolic curve (4.5%; p=0.25). Although the OGTT was more often linear with occurrence of morbidity (41.7% vs 11.1%), major morbidity (66.7% vs 30%) and PLF by 50-50 criteria (66.7% vs 30%), it was not statistically significant. The linearity index was marginally lower (0.9 vs 1.2) in the presence of major morbidity and PLF by 50-50 criteria. Conclusions Linear OGTT affects the PLF and major morbidity, therein impacting the hospital stay. OGTT LI and PHRR can help predict postoperative outcome for a given extent of liver resection. PMID:28317039

  1. Glucose intolerance in uremic patients: the relative contributions of impaired beta-cell function and insulin resistance.

    PubMed

    Alvestrand, A; Mujagic, M; Wajngot, A; Efendic, S

    1989-04-01

    Glucose tolerance and tissue sensitivity to insulin were examined in 19 renal failure patients on chronic regular hemodialysis (group U) and in 6 matched control subjects with normal renal function (group A). Based on glucose tolerance as assessed by an oral glucose tolerance test (OGTT), glucose tolerance was normal in 5 (group U:N), borderline in 5 (group U:BL) and decreased in 9 uremic subjects (group U:D). Compared with group A the uremics demonstrated significantly (p less than 0.01) impaired insulin sensitivity as assessed by a continuous mixed infusion of somatostatin, insulin and glucose (SIGIT). In addition 19 non-diabetic subjects with normal fasting blood glucose and normal renal function, matching the uremic patients with respect to glucose tolerance as assessed by OGTT, were studied (group B). In group B impairments in both insulin secretion and insulin sensitivity tended to be more pronounced in subjects with decreased OGTT as compared with those with borderline OGTT. In contrast, insulin resistance was present to a similar degree in uremic subjects of group U:N, U:BL and U:D. During SIGIT endogenous insulin, glucagon and growth hormone (GH) were suppressed in both uremic and control subjects. This implies that insulin resistance in uremia is most likely not due to hyperglucagonemia or abnormal GH metabolism. During OGTT subjects of group U:N had significantly higher insulin response than subjects of group U:BL (p less than 0.02) and group U:D (p less than 0.01). Insulinogenic index was significantly higher in group U:N than in group U:BL (p less than 0.02) and group U:D (p = 0.01) and was higher in group U:BL than in group U:D (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Amino acid mixture acutely improves the glucose tolerance of healthy overweight adults.

    PubMed

    Wang, Bei; Kammer, Lynne M; Ding, Zhenping; Lassiter, David G; Hwang, Jungyun; Nelson, Jeffrey L; Ivy, John L

    2012-01-01

    Certain amino acids have been reported to influence carbohydrate metabolism and blood glucose clearance, as well as improve the glucose tolerance in animal models. We hypothesized that an amino acid mixture consisting of isoleucine and 4 additional amino acids would improve the glucose response of healthy overweight men and women to an oral glucose tolerance test (OGTT). Twenty-two overweight healthy subjects completed 2 OGTTs after consuming 2 different test beverages. The amino acid mixture beverage (CHO/AA) consisted of 0.088 g cystine 2HCl, 0.043 g methionine, 0.086 g valine, 12.094 g isoleucine, 0.084 g leucine, and 100 g dextrose. The control beverage (CHO) consisted of 100 g dextrose only. Venous blood samples were drawn 10 minutes before the start of ingesting the drinks and 15, 30, 60, 120, and 180 minutes after the completion of the drinks. During the OGTT, the plasma glucose response for the CHO/AA treatment was significantly lower than that of the CHO treatment (P < .01), as was the plasma glucose area under the curve (CHO/AA 806 ± 31 mmol/L·3 hours vs CHO 942 ± 40 mmol/L·3 hours). Differences in plasma glucose between treatments occurred at 30, 60, 120, and 180 minutes after supplement ingestion. Plasma glucagon during the CHO/AA treatment was significantly higher than during the CHO treatment. However, there were no significant differences in plasma insulin or C-peptide responses between treatments. These results suggest that the amino acid mixture lowers the glucose response to an OGTT in healthy overweight subjects in an insulin-independent manner.

  3. Inhibition of sweet chemosensory receptors alters insulin responses during glucose ingestion in healthy adults: a randomized crossover interventional study.

    PubMed

    Karimian Azari, Elnaz; Smith, Kathleen R; Yi, Fanchao; Osborne, Timothy F; Bizzotto, Roberto; Mari, Andrea; Pratley, Richard E; Kyriazis, George A

    2017-04-01

    Background: Glucose is a natural ligand for sweet taste receptors (STRs) that are expressed on the tongue and in the gastrointestinal tract. Whether STRs directly contribute to the regulation of glucose homeostasis in response to glucose ingestion is unclear.Objective: We sought to determine the metabolic effects of the pharmacologic inhibition of STRs in response to an oral glucose load in healthy lean participants.Design: Ten healthy lean participants with a body mass index (in kg/m(2)) of 22.4 ± 0.8 were subjected to an oral-glucose-tolerance test (OGTT) on 4 separate days with the use of a randomized crossover design. Ten minutes before the 75-g OGTT, participants consumed a preload solution of either 300 parts per million (ppm) saccharin or water with or without the addition of 500 ppm lactisole, a human-specific inhibitor of STRs. When present, lactisole was included in both the preload and OGTT solutions. We assessed plasma responses of glucose, insulin, C-peptide, glucagon, glucagon-like peptides 1 and 2, gastric inhibitory peptide, acetaminophen, and 3-O-methylglucose. With the use of mathematical modeling, we estimated gastric emptying, glucose absorption, β-cell function, insulin sensitivity and clearance, and the portal insulin:glucagon ratio.Results: The addition of lactisole to the OGTT caused increases in the plasma responses of insulin (P = 0.012), C-peptide (P = 0.004), and the insulin secretory rate (P = 0.020) compared with the control OGTT. The addition of lactisole also caused a slight reduction in the insulin sensitivity index independent of prior saccharin consumption (P < 0.025). The ingestion of saccharin before the OGTT did not alter any of the measured variables but eliminated the effects of lactisole on the OGTT.Conclusion: The pharmacologic inhibition of STRs in the gastrointestinal tract alters insulin responses during an oral glucose challenge in lean healthy participants. This trial was registered at clinicaltrials.gov as NCT

  4. [Diagnostic value of fasting glucose, fructosamine, and glycated haemoglobin HbA(1c) with regard to ADA 1997 and who 1998 criteria for detecting diabetes and other glucose tolerance abnormalities].

    PubMed

    Gołembiewska, Edyta

    2004-01-01

    New diagnostic criteria for diabetes mellitus proposed by the American Diabetes Association in 1997 and the World Heath Organization Consultation Report in 1998 recommend lowering of the fasting plasma glucose (FPG) to 7.0 mmol/L. This change in the diagnostic FPG cut-off point was based on the results of well-documented epidemiological studies showing that increased risk of microangiopathy starts at values closer to 7.0 than 7.8 mmol/L used in the past. To facilitate the diagnosis, ADA Expert Committee recommends using FPG as the main diagnostic tool and eliminating OGTT from routine clinical practice. In contrast to ADA, WHO Consultation Group strongly recommended keeping OGTT in routine use. Due to the inconvenience, poor reproducibility, non-physiological character and labour-intensiveness of OGTT, an alternative test has been sought. The aim of this study was to determine whether fasting capillary glucose (FCG) along with fructosamine and glycated haemoglobin (HbA(1c)) perform better for the detection of glucose tolerance abnormalities than FCG alone. OGTT was performed in 1528 patients. Serum fructosamine was determined in 480 and glycated haemoglobin in 234 of these patients. To assess the value of FCG, fructosamine and glycated haemoglobin in predicting post-load glycaemia and detecting glucose tolerance abnormalities, multiple linear regression analysis and Receiver Operating Characteristics analysis were done. Fructosamine correlated stronger with 2h-postload glucose concentrations than with fasting glucose. HbA(1c) correlated stronger with FCG than with 2h-postload glucose. Combined use of fructosamine and FCG predicted 2h-postload glucose better than combined use of FCG and HbA(1c). Receiver Operating Characteristics curve analysis showed that FCG was the best criterion in discriminating diabetes. Combined use of FCG and fructosamine slightly improved the ability to discriminate glucose tolerance abnormalities from normal glucose tolerance. The

  5. Amino Acid and Biogenic Amine Profile Deviations in an Oral Glucose Tolerance Test: A Comparison between Healthy and Hyperlipidaemia Individuals Based on Targeted Metabolomics

    PubMed Central

    Li, Qi; Gu, Wenbo; Ma, Xuan; Liu, Yuxin; Jiang, Lidan; Feng, Rennan; Liu, Liyan

    2016-01-01

    Hyperlipidemia (HLP) is characterized by a disturbance in lipid metabolism and is a primary risk factor for the development of insulin resistance (IR) and a well-established risk factor for cardiovascular disease and atherosclerosis. The aim of this work was to investigate the changes in postprandial amino acid and biogenic amine profiles provoked by an oral glucose tolerance test (OGTT) in HLP patients using targeted metabolomics. We used ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry to analyze the serum amino acid and biogenic amine profiles of 35 control and 35 HLP subjects during an OGTT. The amino acid and biogenic amine profiles from 30 HLP subjects were detected as independent samples to validate the changes in the metabolites. There were differences in the amino acid and biogenic amine profiles between the HLP individuals and the healthy controls at baseline and after the OGTT. The per cent changes of 13 metabolites from fasting to the 2 h samples during the OGTT in the HLP patients were significantly different from those of the healthy controls. The lipid parameters were associated with the changes in valine, isoleucine, creatine, creatinine, dimethylglycine, asparagine, serine, and tyrosine (all p < 0.05) during the OGTT in the HLP group. The postprandial changes in isoleucine and γ-aminobutyric acid (GABA) during the OGTT were positively associated with the homeostasis model assessment of insulin resistance (HOMA-IR; all p < 0.05) in the HLP group. Elevated oxidative stress and disordered energy metabolism during OGTTs are important characteristics of metabolic perturbations in HLP. Our findings offer new insights into the complex physiological regulation of metabolism during the OGTT in HLP. PMID:27338465

  6. Distinguishing between persistent and transient impaired glucose tolerance using a prediction model.

    PubMed

    Bourn, D M; Williams, S M; Mann, J I

    1992-10-01

    Screening for impaired glucose tolerance (IGT) and Type 2 (non-insulin dependent) diabetes was carried out in 777 people and those with high blood glucose levels completed three 2-h oral glucose tolerance tests (OGTT). Blood lipid levels, fasting and 2-h insulin levels, body mass index, and blood pressure were also measured and family history of Type 2 diabetes recorded. Fifty people were identified with IGT and of these 21 were found to have persistent IGT and 29 transient IGT. A model including the variables body mass index, fasting and 2-h insulin levels, fasting triglycerides and family history of Type 2 diabetes was developed using the Speigelhalter-Knill-Jones weighting method to predict subjects with persistent IGT. This model could be useful in identifying people with persistent IGT and therefore eliminate the need for repeat OGTTs which are time consuming and expensive.

  7. 77 FR 34810 - Determination of Failure To Attain by 2005 and Determination of Current Attainment of the 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    .... 2004); and Our Children's Earth Foundation v. EPA, No. 04-73032 (9th Cir. June 28, 2005) (memorandum... attaining the revoked 1-hour ozone standard since 2008. EPA's determination that the area has attained the 1... inspection during normal business hours at the Air Protection Division, U.S. Environmental Protection...

  8. 75 FR 232 - Finding of Failure To Submit Certain State Implementation Plans Required for the 1-Hour Ozone NAAQS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... Ozone NAAQS AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: The EPA is... Implementation Plans (SIPs) for three ozone nonattainment areas to satisfy certain requirements of the Clean Air Act (CAA) for the 1-hour ozone National Ambient Air Quality Standards (NAAQS). To accompany...

  9. Insulin and glucose responses during bed rest with isotonic and isometric exercise

    NASA Technical Reports Server (NTRS)

    Dolkas, C. B.; Greenleaf, J. E.

    1977-01-01

    The effects of daily intensive isotonic (68% maximum oxygen uptake) and isometric (21% maximum extension force) leg exercise on plasma insulin and glucose responses to an oral glucose tolerance test (OGTT) during 14-day bed-rest (BR) periods were investigated in seven young healthy men. The OGTT was given during ambulatory control and on day 10 of the no-exercise, isotonic, and isometric exercise BR periods during the 15-wk study. The subjects were placed on a controlled diet starting 10 days before each BR period. During BR, basal plasma glucose concentration remained unchanged with no exercise, but increased (P less 0.05) to 87-89 mg/100 ml with both exercise regimens on day 2, and then fell slightly below control levels on day 13. The fall in glucose content during BR was independent of the exercise regimen and was an adjustment for the loss of plasma volume. The intensity of the responses of insulin and glucose to the OGTT was inversely proportional to the total daily energy expenditure during BR. It was estimated that at least 1020 kcal/day must be provided by supplemental exercise to restore the hyperinsulinemia to control levels.

  10. Risk Factors and Plasma Glucose Profile of Gestational Diabetes in Omani Women

    PubMed Central

    Chitme, Havagiray R; Al Shibli, Sumaiya Abdallah Said; Al-Shamiry, Raya Mahmood

    2016-01-01

    Objectives We sought to conduct a detailed study on the risk factors of gestational diabetes mellitus (GDM) in Omani women to determine the actual and applicable risk factors and glucose profile in this population. Methods We conducted a cross-sectional case-control study using pregnant women diagnosed with GDM. Pregnant women without GDM were used as a control group. We collected information related to age, family history, prior history of pregnancy complications, age of marriage, age of first pregnancy, fasting glucose level, and oral glucose tolerance test (OGTT) results from three hospitals in Oman through face-to-face interviews and hospital records. Results The median age of women with GDM was 33 years old (p < 0.050). A significant risk was noted in women with a history of diabetes (p < 0.001), and those with mothers’ with a history of GDM. A significant (p < 0.010) relationship with a likelihood ratio of 43.9 was observed between the incidence of GDM in women with five or six pregnancies, a history of > 3 deliveries, height < 155 cm, and pregnancy or marriage at age < 18 years (p < 0.010). The mean difference in random plasma glucose, one-hour OGTT, and two-hour OGTT was significantly higher in GDM cases compared to control. Conclusions Glucose profile, family history, anthropometric profile, and age of first pregnancy and marriage should be considered while screening for GDM and determining the care needs of Omani women with GDM. PMID:27602192

  11. Lag time changes between capillary blood glucose and in-vivo interstitial glucose levels by HATR-FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Eikje, Natalja Skrebova

    2011-03-01

    Method of the lag/latency time (LT) measurement, calculation and interpretation can be simultaneously applied to study in vivo glucose diffusion from the capillary to the skin tissue, to calibrate spectroscopically measured glucose levels during real-time glucose monitoring of dynamic processes in the skin tissue and to study glucose optical properties in the living skin tissue. Based on previous reports on determining interstitial glucose levels and their LT's by HATR-FTIR spectroscopy, here the LT was calculated for each glucose absorbance level at about 1030-41, 1080, 1118 and 1153 cm-1 during oral glucose tolerance test (OGTT) with different doses (5g, 20g, 75g). The LT showed dose-dependency and described intra-/inter-subject changes of skin glucose dynamics in healthy and diabetes subjects. The time required for glucose to diffuse from the capillary to the skin tissue was shorter in a diabetes subject, than in a healthy subject, independently on intaken dose of glucose. Nevertheless, in both subjects the LT changes ranged within 0-50 minutes. Measurement of the LT demonstrated a potential to provide insight to healthy and diabetic glucose dynamics between the blood and interstitial fluid compartments in the upper layer of the skin tissue. Also, the LT might be regarded as a method to calibrate dynamic measurements of glucose in vivo by this spectroscopy method and to characterize living skin tissue glucose optical properties.

  12. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... met its obligation to have a fully-approved attainment demonstration SIP for the 1-hour NAAQS, the... SIP at the time of the effective date of designation and in addition to national or regional measures... obligation for an approved 1-hour ROP SIP, it must develop and submit to EPA all outstanding 1-hour ROP...

  13. Improvement of glucose intolerance by combination of pravastatin and olmesartan in type II diabetic KK-A(y) mice.

    PubMed

    Kanno, Harumi; Iwai, Masaru; Inaba, Shinji; Senba, Izumi; Nakaoka, Hirotomo; Sone, Hisako; Mogi, Masaki; Horiuchi, Masatsugu

    2009-08-01

    The effects of the coadministration of pravastatin and an angiotensin type 1 (AT(1)) receptor blocker, olmesartan, on glucose intolerance were examined using type II diabetic mice. Male KK-A(y) mice (8 weeks of age) were treated with pravastatin and/or olmesartan for 2 weeks. An oral glucose tolerance test (OGTT) was performed with an administration of 2 g kg(-1) glucose. Tissue glucose uptake was determined using 2-[(3)H]deoxyglucose. The treatment of mice with pravastatin attenuated the increase in the plasma glucose level during OGTT in a dose-dependent manner, without affecting the plasma insulin level. Pravastatin increased glucose uptake in insulin-sensitive tissue such as the skeletal muscle and adipose tissue after treatment at 5-20 mg kg(-1) day(-1) for 2 weeks, but not at 1 mg kg(-1) day(-1). The combination of a noneffective dose of pravastatin (1 mg kg(-1) day(-1)) and a noneffective dose of olmesartan (0.5 mg kg(-1) day(-1)) synergistically improved OGTT without affecting the plasma insulin level. This combination also increased 2-[(3)H]deoxyglucose uptake in the skeletal muscle and adipose tissue. The effects of pravastatin or olmesartan on OGTT and tissue 2-[(3)H]deoxyglucose uptake were significantly enhanced by an antioxidant, tempol, whereas the effects of a pravastatin-olmesartan combination were not further enhanced by tempol. These results indicate that the combination of pravastatin and olmesartan synergistically improves glucose intolerance through an increase in tissue glucose uptake. The effects seem to be mediated by an increase in insulin sensitivity through the inhibition of oxidative stress.

  14. Electroencephalogram (EEG) duration needed to detect abnormalities in angelman syndrome: is 1 hour of overnight recording sufficient?

    PubMed

    Robinson, Althea A; Goldman, Suzanne; Barnes, Gregory; Goodpaster, Luke; Malow, Beth A

    2015-01-01

    Approximately, 90% of patients with Angelman syndrome present with epileptic seizures. Obtaining an electroencephalogram (EEG) with sleep improves the chances of detecting ictal, interictal, and benign abnormal rhythms in Angelman syndrome. However, electroencephalograms, even when obtained during sleep, can be challenging in this population because of tactile sensitivities as well as anxiety related to a novel environment. We tested the hypothesis that 1 hour of sleep on an electroencephalogram would provide as much information as an entire night of electroencephalogram recording, yet more than a routine electroencephalogram conducted during the day. Overnight polysomnograms were collected in 14 children with Angelman syndrome seen at Vanderbilt University. All patients who obtained sleep within the first hour of the overnight electroencephalogram had interictal discharges recorded. Our results show that when sleep is obtained, a 1-hour electroencephalogram yields just as much information as recording an entire night.

  15. Hepatic portal vein denervation impairs oral glucose tolerance but not exenatide's effect on glycemia.

    PubMed

    Ionut, Viorica; Castro, Ana Valeria B; Woolcott, Orison O; Stefanovski, Darko; Iyer, Malini S; Broussard, Josiane L; Burch, Miguel; Elazary, Ram; Kolka, Cathryn M; Mkrtchyan, Hasmik; Bediako, Isaac Asare; Bergman, Richard N

    2014-10-15

    The hepatoportal area is an important glucohomeostatic metabolic sensor, sensing hypoglycemia, hyperglycemia, and hormones such as glucagon-like peptide-1 (GLP-1). We have reported previously that activation of hepatoportal sensors by intraportal infusion of glucose and GLP-1 or by subcutaneous administration of GLP-1 receptor activator exenatide and of intraportal glucose improved glycemia independent of corresponding changes in pancreatic hormones. It is not clear whether this effect is mediated via the portal vein (PV) or by direct action on the liver itself. To test whether receptors in the PV mediate exenatide's beneficial effect on glucose tolerance, we performed 1) paired oral glucose tolerance tests (OGTT) with and without exenatide and 2) intravenous glucose tolerance tests before and after PV denervation in canines. Denervation of the portal vein affected oral glucose tolerance; post-denervation (POST-DEN) OGTT glucose and insulin AUC were 50% higher than before denervation (P = 0.01). However, portal denervation did not impair exenatide's effect to improve oral glucose tolerance (exenatide effect: 48 ± 12 mmol·l⁻¹·min before vs. 64 ± 26 mmol·l⁻¹·min after, P = 0.67). There were no changes in insulin sensitivity or secretion during IVGTTs. Portal vein sensing might play a role in controlling oral glucose tolerance during physiological conditions but not in pharmacological activation of GLP-1 receptors by exenatide.

  16. Amantadine reduces glucagon and enhances insulin secretion throughout the oral glucose tolerance test: central plus peripheral nervous system mechanisms

    PubMed Central

    Lechin, Fuad; van der Dijs, Bertha; Pardey-Maldonado, Betty; Rivera, Jairo E; Lechin, Marcel E; Baez, Scarlet

    2009-01-01

    Objective The purpose of the trial was to examine the effects of amantadine, a N-methyl-D-aspartate (NMDA) antagonist, on the oral glucose tolerance test (OGTT) plus insulin, glucagon and neurotransmitters circulating levels. Previous findings showed that hyperinsulinism and type 2 diabetes are positively associated with neural sympathetic and adrenal sympathetic activities, respectively. These peripheral sympathetic branches depend on the pontine (A5-noradrenergic) and the rostral ventrolateral (C1-adrenergic) medullary nuclei. They are excited by glutamate axons which act at NMDA postsynaptic receptors. Research design and methods One OGTT plus placebo and one OGTT plus oral amantadine test were carried out two weeks apart in 15 caucasic normal voluntary humans. Noradrenaline, adrenaline, dopamine, plasma-free serotonin, platelet serotonin, glucose, glucagon, and insulin were measured throughout the 180-minute testing period. Results Maximal reductions of plasma glucose and glucagon plus exacerbated insulin rises were significantly greater throughout the oral glucose plus amantadine test than those registered throughout the oral glucose plus placebo challenge. The above findings were paralleled by greater than normal noradrenaline/adrenaline plasma ratio increases. In addition, maximal reductions of the platelet serotonin and plasma serotonin circulating values contrasted with the normal rises of these parameters, always registered during the glucose load plus placebo challenge. Conclusion This study supports the theory that amantadine might be a powerful antidiabetic tool and could be added to the therapeutic arsenal against type 2 diabetes. PMID:21437134

  17. Electrical stimulation of embryonic neurons for 1 hour improves axon regeneration and the number of reinnervated muscles that function.

    PubMed

    Liu, Yang; Grumbles, Robert M; Thomas, Christine K

    2013-07-01

    Motoneuron death after spinal cord injury or disease results in muscle denervation, atrophy, and paralysis. We have previously transplanted embryonic ventral spinal cord cells into the peripheral nerve to reinnervate denervated muscles and to reduce muscle atrophy, but reinnervation was incomplete. Here, our aim was to determine whether brief electrical stimulation of embryonic neurons in the peripheralnerve changes motoneuron survival, axon regeneration, and muscle reinnervation and function because neural depolarization is crucial for embryonic neuron survival and may promote activity-dependent axon growth. At 1 week after denervation by sciatic nerve section, embryonic day 14 to 15 cells were purified for motoneurons, injected into the tibial nerve of adult Fischer rats, and stimulated immediatelyfor up to 1 hour. More myelinated axons were present in tibial nerves 10 weeks after transplantation when transplants had been stimulated acutely at 1 Hz for 1 hour. More muscles were reinnervated if the stimulation treatment lasted for 1 hour. Reinnervation reduced muscle atrophy, with or without the stimulation treatment. These data suggest that brief stimulation of embryonic neurons promotes axon growth, which has a long-term impact on muscle reinnervation and function. Muscle reinnervation is important because it may enable the use of functional electrical stimulation to restore limb movements.

  18. Electrical Stimulation of Embryonic Neurons for 1 Hour Improves Axon Regeneration and the Number of Reinnervated Muscles that Function

    PubMed Central

    Liu, Yang; Grumbles, Robert M.; Thomas, Christine K.

    2013-01-01

    Motoneuron death following spinal cord injury or disease results in muscle denervation, atrophy, and paralysis. We have previously transplanted embryonic ventral spinal cord cells into peripheral nerve to reinnervate denervated muscles and to reduce muscle atrophy, but reinnervation was incomplete. Here, our aim was to determine whether brief electrical stimulation of embryonic neurons in peripheral nerve changes motoneuron survival, axon regeneration, and muscle reinnervation and function because neural depolarization is crucial for embryonic neuron survival and may promote activity-dependent axon growth. At 1 week after denervation by sciatic nerve section, embryonic day 14-15 cells were purified for motoneurons, injected into the tibial nerve of adult Fischer rats, and stimulated immediately for up to 1 hour. More myelinated axons were present in tibial nerves when transplants had been stimulated at 1 Hz for 1 hour at 10 weeks following transplantation. More muscles were reinnervated if the stimulation treatment lasted for 1 hour. Reinnervation reduced muscle atrophy, with or without the stimulation treatment. These data suggest that brief stimulation of embryonic neurons promotes axon growth, which has a long-term impact on muscle reinnervation and function. Muscle reinnervation is important because it may enable the use of functional electrical stimulation to restore limb movements. PMID:23771218

  19. Application of dynamic metabolomics to examine in vivo skeletal muscle glucose metabolism in the chronically high-fat fed mouse

    SciTech Connect

    Kowalski, Greg M.; De Souza, David P.; Burch, Micah L.; Hamley, Steven; Kloehn, Joachim; Selathurai, Ahrathy; Tull, Dedreia; O'Callaghan, Sean; McConville, Malcolm J.; Bruce, Clinton R.

    2015-06-19

    Rationale: Defects in muscle glucose metabolism are linked to type 2 diabetes. Mechanistic studies examining these defects rely on the use of high fat-fed rodent models and typically involve the determination of muscle glucose uptake under insulin-stimulated conditions. While insightful, they do not necessarily reflect the physiology of the postprandial state. In addition, most studies do not examine aspects of glucose metabolism beyond the uptake process. Here we present an approach to study rodent muscle glucose and intermediary metabolism under the dynamic and physiologically relevant setting of the oral glucose tolerance test (OGTT). Methods and results: In vivo muscle glucose and intermediary metabolism was investigated following oral administration of [U-{sup 13}C] glucose. Quadriceps muscles were collected 15 and 60 min after glucose administration and metabolite flux profiling was determined by measuring {sup 13}C mass isotopomers in glycolytic and tricarboxylic acid (TCA) cycle intermediates via gas chromatography–mass spectrometry. While no dietary effects were noted in the glycolytic pathway, muscle from mice fed a high fat diet (HFD) exhibited a reduction in labelling in TCA intermediates. Interestingly, this appeared to be independent of alterations in flux through pyruvate dehydrogenase. In addition, our findings suggest that TCA cycle anaplerosis is negligible in muscle during an OGTT. Conclusions: Under the dynamic physiologically relevant conditions of the OGTT, skeletal muscle from HFD fed mice exhibits alterations in glucose metabolism at the level of the TCA cycle. - Highlights: • Dynamic metabolomics was used to investigate muscle glucose metabolism in vivo. • Mitochondrial TCA cycle metabolism is altered in muscle of HFD mice. • This defect was not pyruvate dehydrogenase mediated, as has been previously thought. • Mitochondrial TCA cycle anaplerosis in muscle is virtually absent during the OGTT.

  20. High incidence of abnormal glucose metabolism in acute coronary syndrome patients at a moderate altitude: A sub-Himalayan study

    PubMed Central

    Mokta, Jitender; Kumar, Subash; Ganju, Neeraj; Mokta, Kiran; Panda, Prashant Kumar; Gupta, Swatantra

    2017-01-01

    Background: Abnormal glucose metabolic status at admission is an important marker of future cardiovascular events and long-term mortality after acute coronary syndrome (ACS), whether or not they are known diabetics. Objective: The aims were to study the prevalence of abnormal glucose metabolism in ACS patients and to compare the different methods of diagnosing diabetes in ACS patients. Methods: We did a prospective study. About 250 consecutive nondiabetic patients (200 men and 50 women) with ACS admitted to a tertiary care institute of Himachal Pradesh in 1 year were enrolled. Admission plasma glucose, next morning fasting plasma glucose (FPG), A1C, and a standardized 75-g oral glucose tolerance test (OGTT) 72 h after admission were done. Glucose metabolism was categorized as normal glucose metabolism, impaired glucose metabolism (impaired fasting glucose or impaired glucose tolerance [IGT]), and diabetes. Diabetes was arbitrarily classified further as undiagnosed (HBA1c ≥6.5%) or possibly stress diabetes (HBA1c <6.5%). A repeat OGTT after 3 months in objects with IGT and stress hyperglycemia at a time of admission was done. Results: The mean age was 54 ± 12.46 years. The mean plasma glucose at admission was 124 ± 53.96 mg/dL, and the mean FPG was 102 ± 27.07 mg/dL. The mean 2-h postglucose load concentration was 159.5 ± 56.58 mg/dL. At baseline, 95 (38%) had normal glucose metabolism, 95 (38%) had impaired glucose metabolism (IGT and or IGT) and 60 (24%) had diabetes; 48 (19.2%) were undiagnosed diabetes and 12 (4.8%) had stress hyperglycemia. At follow up 58.66% and 55.55% of patients with impaired glucose tolerance and stress hyperglycemia continued to have impaired glucose tolerance respectively. About 75 gm OGTT has highest sensitivity and specificity to diagnose diabetes, whereas A1C most specific to rule out stress hyperglycemia. Conclusions: In this small hilly state of India, abnormal glucose metabolism (previously undiagnosed diabetes and IGT) is

  1. Orally administered glucagon-like peptide-1 affects glucose homeostasis following an oral glucose tolerance test in healthy male subjects.

    PubMed

    Steinert, R E; Poller, B; Castelli, M C; Friedman, K; Huber, A R; Drewe, J; Beglinger, C

    2009-12-01

    Glucagon-like peptide-1 (GLP-1) exerts several effects on glucose homeostasis and reduces food intake. After its release from intestinal L cells, GLP-1 is subject to (i) rapid breakdown by dipeptidyl peptidase IV and (ii) high liver extraction. The highest concentrations of GLP-1 are found in the splanchnic blood rather than in the systemic circulation. An oral delivery system would mimic endogenous secretion. Here we investigated the pharmacokinetic/pharmacodynamic (PK/PD) effects of a single dose (2 mg) of oral GLP-1 administered prior to an oral glucose tolerance test (OGTT) in 16 healthy males. GLP-1 was rapidly absorbed from the gut, leading to tenfold higher plasma concentrations compared with controls. The PD profile was consistent with reported pharmacology; GLP-1 significantly stimulated basal insulin release (P < 0.027), with marked effects on glucose levels. The postprandial glucose peak was delayed with GLP-1, suggesting an effect on gastric emptying.

  2. Is Type 2 Diabetes Really Resolved after Laparoscopic Sleeve Gastrectomy? Glucose Variability Studied by Continuous Glucose Monitoring

    PubMed Central

    Capoccia, D.; Coccia, F.; Guida, A.; Rizzello, M.; De Angelis, F.; Silecchia, G.; Leonetti, F.

    2015-01-01

    The study was carried out on type 2 diabetic obese patients who underwent laparoscopic sleeve gastrectomy (LSG). Patients underwent regular glycemic controls throughout 3 years and all patients were defined cured from diabetes according to conventional criteria defined as normalization of fasting glucose levels and glycated hemoglobin in absence of antidiabetic therapy. After 3 years of follow-up, Continuous Glucose Monitoring (CGM) was performed in each patient to better clarify the remission of diabetes. In this study, we found that the diabetes resolution after LSG occurred in 40% of patients; in the other 60%, even if they showed a normal fasting glycemia and A1c, patients spent a lot of time in hyperglycemia. During the oral glucose tolerance test (OGTT), we found that 2 h postload glucose determinations revealed overt diabetes only in a small group of patients and might be insufficient to exclude the diagnosis of diabetes in the other patients who spent a lot of time in hyperglycemia, even if they showed a normal glycemia (<140 mg/dL) at 120 minutes OGTT. These interesting data could help clinicians to better individualize patients in which diabetes is not resolved and who could need more attention in order to prevent chronic complications of diabetes. PMID:25954762

  3. Exhaled breath condensate pH decreases following oral glucose tolerance test.

    PubMed

    Bikov, Andras; Pako, Judit; Montvai, David; Kovacs, Dorottya; Koller, Zsofia; Losonczy, Gyorgy; Horvath, Ildiko

    2015-12-15

    Exhaled breath condensate (EBC) pH is a widely measured non-invasive marker of airway acidity. However, some methodological aspects have not been thoroughly investigated. The aim of the study was to determine the effect of oral glucose tolerance test (OGTT) on EBC pH in attempt to better standardize its measurement. Seventeen healthy subjects (24  ±  2 years, 6 men, 11 women) participated in the study. EBC collection and capillary blood glucose measurements were performed before as well as 0, 30, 60 and 120 min after a standardized OGTT test. The rate of respiratory droplet dilution and pH were evaluated in EBC. Blood glucose significantly increased at 30 min and maintained elevation after 60 and 120 min following OGTT. Compared to baseline (7.99  ±  0.25) EBC pH significantly decreased immediately after OGTT (7.41  ±  0.47); this drop sustained over 30 (7.44  ±  0.72) and 60 min (7.62  ±  0.44) without a significant difference at 120 min (7.78  ±  0.26). No change was observed in the rate of respiratory droplet dilution. There was no relationship between blood glucose and EBC pH values. Sugar intake may significantly decrease EBC pH. This effect needs to be considered when performing EBC pH studies. Further experiments are also warranted to investigate the effect of diet on other exhaled biomarkers.

  4. Comparison of glucose tolerance tests to detect the insulin sensitizing effects of a bout of continuous exercise.

    PubMed

    Ortega, Juan Fernando; Hamouti, Nassim; Fernández-Elías, Valentín Emilio; Mora-Rodriguez, Ricardo

    2014-07-01

    The aim of the present study was to determine which of the available glucose tolerance tests (oral (OGTT) vs. intravenous (IVGTT)) could more readily detect the insulin sensitizing effects of a bout of continuous exercise. Ten healthy moderately fit young men (V̇O2peak of 45.4 ± 1.8 mL·kg(-1)·min(-1); age 27.5 ± 2.7 yr) underwent 4 OGTT and 4 IVGTT on different days following a standardized dinner and overnight fast. One test was performed immediately after 55 min of cycle-ergometer exercise at 60% V̇O2peak. Insulin sensitivity index was determined during a 50 min IVGTT according to Tura (CISI) and from a 120 min OGTT using the Matsuda composite index (MISI). After exercise, MISI improved 29 ± 10% without reaching statistical significance (p = 0.182) due to its low reproducibility (coefficient of variation 16 ± 3%; intra-class reliability 0.846). However, CISI significantly improved (50 ± 4%; p < 0.001) after exercise showing better reproducibility (coefficient of variation 13 ± 4%; intra-class reliability 0.955). Power calculation revealed that 6 participants were required for detecting the effects of exercise on insulin sensitivity when using IVGTT, whereas 54 were needed when using OGTT. The superior response of CISI compared with MISI suggests the preferential use of IVGTT to assess the effects of exercise on insulin sensitivity when using a glucose tolerance test.

  5. [Voglibose for the prevention of type 2 diabetes mellitus: a randomised, double-blind trial in Japanese subjects with impaired glucose tolerance].

    PubMed

    Kawamori, Ryuzo

    2010-05-01

    The study to assess whether voglibose could prevent type 2 diabetes developing in high-risk Japanese subjects with impaired glucose tolerance (IGT) were performed. This was a multicenter, randomised, double-blind, parallel group trial comparing voglibose 0.2 mg three times a day and corresponding placebo. 1,780 eligible subjects received standard diet and exercise therapy, and 897 were randomised to receive voglibose and 883 placebo. The study was planned for treatment to be continued until participants developed type 2 diabetes[primary endpoint; determined by bi-annual oral glucose tolerance tests (OGTTs) as well as fasting blood glucose measured every 3 months] or normalisation of the OGTT or for a minimum of 3 years, subject to the findings of an interim analysis. The interim analysis significantly favoured voglibose and this end-of-study report involves individuals treated for an average of 48.1 weeks. Subjects treated with voglibose had a significantly lower risk for the progression to type 2 diabetes than placebo (50/897 vs 106/881: hazard ratio 0.595). Also, significantly more subjects in the voglibose group achieved a normal OGTT compared with those in the placebo group (599/897 vs 454/881: hazard ratio 1.539). Voglibose, in addition to standard care with diet and exercise, was effective in preventing the progression of IGT to type 2 diabetes and in facilitating the normalisation of the OGTT in high-risk Japanese subjects with IGT.

  6. Noninvasive blood glucose monitoring with laser diode

    NASA Astrophysics Data System (ADS)

    Zhang, Xiqin; Chen, Jianhong; Ooi, Ean Tat; Yeo, Joon Hock

    2006-02-01

    The non-invasive measurement of blood sugar level was studied by use of near infrared laser diodes. The in vitro and in vivo experiments were carried out using six laser diodes having wavelengths range from 1550 nm to 1750nm. Several volunteers were tested for OGTT (Oral Glucose Tolerance Test) experiment. We took blood from a fingertip and measured its concentration with a glucose meter while taking signal voltage from laser diodes system. The data of signal voltage were processed to do calibration and prediction; in this paper PLS (Partial Least Square) method was used to do modeling. For in vitro experiment, good linear relationship between predicted glucose concentration and real glucose concentration was obtained. For in vivo experiments, we got the blood sugar level distributions in Clarke error grid that is a reference for doctors to do diagnosis and treatment. In the Clarke error grid, 75% of all data was in area A and 25 % was in area B. From the in vitro and in vivo results we know that multiple laser diodes are suitable for non-invasive blood glucose monitoring.

  7. [Evaluation of oral glucose tolerance test in the assessment of reserved function of liver for patients with hepatocellular carcinoma].

    PubMed

    Wen, T; Zheng, G; Meng, X; Chen, L

    1997-06-01

    The aim of this study was to evaluate oral glucose tolerance test(OGTT)in the assessment of reserved function of liver for predicting the tolerability of patients to hepatectomy and hence provided a criteria for selecting the candidates for undergoing hepatectomy, since the majority of hepatocellular carcinoma (HCC) patients were associated with posthepatitis cirrhosis. The preoperative and postoperative OGTT and liver biopsy for pathological investigation were carried out in 62 cases of hepatecomized patients and 49 cases of unresected patients for comparison. The results revealed that the patients whose preoperative OGTT curve was of P type recovered uneventfully after hepatectomy, but those whose curve was of L type of tolerated poorly to hepatectomy and were liable to postoperative hepatic failure and complications. The severity of cirrbosis in those poor risk patients fell to C III or C IV histological degree. 29 patients with intermediate feature of OGTT curve between P type and L type, i.e. I type underwent regional vascular occlusion at hepatic hilus as hepatectomy, and infusion of Danshen extract solution before vascular occlusion to prevent hepatocytes from reperfusion injury. Of them, 20 recovered uneventfully, 8 suffered from complications such as ascites and/or juandice, and 1 died within 1 month after operation. The followup study showed that the survival time of patients with P type OGTT curve was longer than that of I type, and the latter was longer than that of L type. The pattern of OGTT curve could change from preoperative P type to postoperative L type, depending on the severity of vascular interruption of liver and the ischemic injury to hepatocytic mass in operation.

  8. The effect of endurance training and subsequent physical inactivity on glycaemic control after oral glucose load and physical exercise in healthy men

    NASA Astrophysics Data System (ADS)

    Radikova, Zofia; Ksinantova, Lucia; Kaciuba-Uscilko, Hanna; Nazar, Krystyna; Vigas, Milan; Koska, Juraj

    2007-02-01

    Physical inactivity during space flight has a profound effect on glucose metabolism. The aim of this study was to test whether endurance training (ET) may improve a negative effect of subsequent -6∘ head-down bed rest (HDBR) on glucose metabolism. Fourteen healthy males completed the study consisting of 6 weeks lasting ET followed by 6 days HDBR. Treadmill exercise at 80% of pre-training VO2max and 75 g oral glucose tolerance test (OGTT) were performed before and after ET as well as after HDBR. ET increased VO2max by 11%. ET significantly lowered while HDBR had no effect on fasting and OGTT plasma glucose levels. ET had no effect while HDBR was followed by an augmentation of insulin and C-peptide response to OGTT. Insulin sensitivity tended to increase after ET and to decrease during HDBR, however, mostly without statistical significance. Plasma glucose, insulin and C-peptide response to exercise were elevated after HDBR only. Our study shows that antecedent physical training could ameliorate a negative effect of simulated microgravity on insulin-mediated glucose metabolism.

  9. Development and assessment of the disposition index based on the oral glucose tolerance test in subjects with different glycaemic status.

    PubMed

    Santos, J L; Yévenes, I; Cataldo, L R; Morales, M; Galgani, J; Arancibia, C; Vega, J; Olmos, P; Flores, M; Valderas, J P; Pollak, F

    2016-06-01

    Insulin secretion and insulin sensitivity indexes are related by hyperbolic functions, allowing the calculation of the disposition index (DI) as the product of the acute insulin response (AIR) and the insulin sensitivity index (Si) from intravenous glucose tolerance test (IVGTT). Our objective was to develop an oral-DI based on the oral glucose tolerance test (OGTT) and to assess its association with glucose tolerance status. This research is structured in three studies. Study 1: OGTT were performed in 833 non-diabetic Chilean women (18-60 years) without family history of diabetes mellitus. Study 2: an independent group of n = 57 non-diabetic (18-46 years) without family history of diabetes mellitus carried out an OGTT and an abbreviated IVGTT. Study 3: a sample of 1674 Chilean adults (18-60 years) with different glycaemic status performed an OGTT. An adequate statistical fit for a rectangular hyperbola was found between the area under the curve of insulin-to-glucose ratio (AUCI/G-R) and the Matsuda ISI-COMP index (study 1). The oral-DI derived as AUCI/G-R × ISI-COMP was previously termed insulin-secretion-sensitivity index-2 (ISSI-2). ISSI-2 significantly correlated with DI from IVGTT (rho = 0.34; p = 0.009) (study 2). ISSI-2 shows important differences across groups of subjects with different glycaemic status (study 3). We have confirmed that ISSI-2 replicates the mathematical properties of DI, showing significant correlations with DI from the abbreviated MM-IVGTT. These results indicate that ISSI-2 constitutes a surrogate measure of insulin secretion relative to insulin sensitivity and emphasizes the pivotal role of impaired insulin secretion in the development of glucose homeostasis dysregulation.

  10. Lactation Intensity and Postpartum Maternal Glucose Tolerance and Insulin Resistance in Women With Recent GDM

    PubMed Central

    Gunderson, Erica P.; Hedderson, Monique M.; Chiang, Vicky; Crites, Yvonne; Walton, David; Azevedo, Robert A.; Fox, Gary; Elmasian, Cathie; Young, Stephen; Salvador, Nora; Lum, Michael; Quesenberry, Charles P.; Lo, Joan C.; Sternfeld, Barbara; Ferrara, Assiamira; Selby, Joseph V.

    2012-01-01

    OBJECTIVE To examine the association between breastfeeding intensity in relation to maternal blood glucose and insulin and glucose intolerance based on the postpartum 2-h 75-g oral glucose tolerance test (OGTT) results at 6–9 weeks after a pregnancy with gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS We selected 522 participants enrolled into the Study of Women, Infant Feeding, and Type 2 Diabetes (SWIFT), a prospective observational cohort study of Kaiser Permanente Northern California members diagnosed with GDM using the 3-h 100-g OGTT by the Carpenter and Coustan criteria. Women were classified as normal, prediabetes, or diabetes according to American Diabetes Association criteria based on the postpartum 2-h 75-g OGTT results. RESULTS Compared with exclusive or mostly formula feeding (>17 oz formula per 24 h), exclusive breastfeeding and mostly breastfeeding (≤6 oz formula per 24 h) groups, respectively, had lower adjusted mean (95% CI) group differences in fasting plasma glucose (mg/dL) of −4.3 (−7.4 to −1.3) and −5.0 (−8.5 to −1.4), in fasting insulin (μU/mL) of −6.3 (−10.1 to −2.4) and −7.5 (−11.9 to −3.0), and in 2-h insulin of −21.4 (−41.0 to −1.7) and −36.5 (−59.3 to −13.7) (all P < 0.05). Exclusive or mostly breastfeeding groups had lower prevalence of diabetes or prediabetes (P = 0.02). CONCLUSIONS Higher intensity of lactation was associated with improved fasting glucose and lower insulin levels at 6–9 weeks’ postpartum. Lactation may have favorable effects on glucose metabolism and insulin sensitivity that may reduce diabetes risk after GDM pregnancy. PMID:22011407

  11. Glucose Variability

    PubMed Central

    Le Floch, Jean-Pierre; Kessler, Laurence

    2016-01-01

    Background: Glucose variability has been suspected to be a major factor of diabetic complications. Several indices have been proposed for measuring glucose variability, but their interest remains discussed. Our aim was to compare different indices. Methods: Glucose variability was studied in 150 insulin-treated diabetic patients (46% men, 42% type 1 diabetes, age 52 ± 11 years) using a continuous glucose monitoring system (668 ± 564 glucose values; mean glucose value 173 ± 38 mg/dL). Results from the mean, the median, different indices (SD, MAGE, MAG, glucose fluctuation index (GFI), and percentages of low [<60 mg/dL] and high [>180 mg/dL] glucose values), and ratios (CV = SD/m, MAGE/m, MAG/m, and GCF = GFI/m) were compared using Pearson linear correlations and a multivariate principal component analysis (PCA). Results: CV, MAGE/m (ns), GCF and GFI (P < .05), MAG and MAG/m (P < .01) were not strongly correlated with the mean. The percentage of high glucose values was mainly correlated with indices. The percentage of low glucose values was mainly correlated with ratios. PCA showed 3 main axes; the first was associated with descriptive data (mean, SD, CV, MAGE, MAGE/m, and percentage of high glucose values); the second with ratios MAG/m and GCF and with the percentage of low glucose values; and the third with MAG, GFI, and the percentage of high glucose values. Conclusions: Indices and ratios provide complementary pieces of information associated with high and low glucose values, respectively. The pairs MAG+MAG/m and GFI+GCF appear to be the most reliable markers of glucose variability in diabetic patients. PMID:26880391

  12. [Insulin response and NEFA behavior in volunteers with a flat response to oral glucose tolerance test].

    PubMed

    Viviani, G; Cordera, R; Maiello, M; De Micheli, A; Odetti, P; Corsi, L; Boeri, D; Prando, R

    1979-07-15

    The insulin response and the NEFA behaviour of 7 lean and 8 obese subjects with a flat response to an oral glucose tolerance test have been studied. A flat response has been defined as one in which the maximum glycemic increase and the area of increase does not exceed 32 mg% and 18 mg% respectively. The insulin response and the NEFA behaviour were similar both in lean and in obese subjects to controls with normal O.G.T.T. The glucose/I.R.I. ratios were increased. A possible physiopathological interpretation is proposed.

  13. Oral glucose tolerance test effects on endothelial inflammation markers in healthy subjects and diabetic patients.

    PubMed

    Derosa, G; D'Angelo, A; Salvadeo, S A T; Ferrari, I; Fogari, E; Gravina, A; Mereu, R; Palumbo, I; Maffioli, P; Randazzo, S; Cicero, A F G

    2010-01-01

    The aim of this study was to evaluate the effect of an oral glucose tolerance test (OGTT) on the level of endothelial dysfunction and vascular inflammation markers in healthy subjects (H) and diabetic overweight patients (D). We enrolled 256 healthy subjects and 274 type 2 diabetic patients. We evaluated blood glucose (BG), soluble intercellular adhesion molecule-1 (sICAM-1), interleukin-6 (IL-6), high-sensitivity C reactive protein (hsCRP), soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble E-selectin (sE-selectin), and tumor necrosis factor-alpha (TNF-alpha) at baseline and after OGTT. We observed that BG, sICAM-1, IL-6, hs-CRP, sVCAM-1, sE-selectin, and TNF-alpha values were higher in D group than in H group. In a large sample of adult healthy subjects and type 2 diabetics we observed that both answer to an OGTT with a significant increase in biomarkers of systemic low-grade inflammation and endothelial dysfunction such as hsCRP, IL-6, TNF-alpha, sICAM-1, sVCAM-1, and sE-selectin. Type 2 diabetics experienced, however, a more significant increase in TNF-alpha, and sE-selectin.

  14. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey; Chronis, Themis

    2015-01-01

    Using satellite-based methods that provide accurate 0-1 hour convective initiation (CI) nowcasts, and rely on proven success coupling satellite and radar fields in the Corridor Integrated Weather System (CIWS; operated and developed at MIT-Lincoln Laboratory), to subsequently monitor for first-flash lightning initiation (LI) and later period lightning trends as storms evolve. Enhance IR-based methods within the GOES-R CI Algorithm (that must meet specific thresholds for a given cumulus cloud before the cloud is considered to have an increased likelihood of producing lightning next 90 min) that forecast LI. Integrate GOES-R CI and LI fields with radar thresholds (e.g., first greater than or equal to 40 dBZ echo at the -10 C altitude) and NWP model data within the WDSS-II system for LI-events from new convective storms. Track ongoing lightning using Lightning Mapping Array (LMA) and pseudo-Geostationary Lightning Mapper (GLM) data to assess per-storm lightning trends (e.g., as tied to lightning jumps) and outline threat regions. Evaluate the ability to produce LI nowcasts through a "lightning threat" product, and obtain feedback from National Weather Service forecasters on its value as a decision support tool.

  15. A periodicity of approximately 1 hour in X-ray emission from the active galaxy RE J1034+396.

    PubMed

    Gierliński, Marek; Middleton, Matthew; Ward, Martin; Done, Chris

    2008-09-18

    Active galactic nuclei and quasars are thought to be scaled-up versions of Galactic black hole binaries, powered by accretion onto supermassive black holes with masses of 10(6)-10(9) M[symbol: see text], as opposed to the approximately 10 M [symbol: see text] in binaries (here M [symbol: see text] is the solar mass). One example of the similarities between these two types of systems is the characteristic rapid X-ray variability seen from the accretion flow. The power spectrum of this variability in black hole binaries consists of a broad noise with multiple quasi-periodic oscillations superimposed on it. Although the broad noise component has been observed in many active galactic nuclei, there have hitherto been no significant detections of quasi-periodic oscillations. Here we report the discovery of an approximately 1-hour X-ray periodicity in a bright active galaxy, RE J1034+396. The signal is highly statistically significant (at the 5.6 sigma level) and very coherent, with quality factor Q > 16. The X-ray modulation arises from the direct vicinity of the black hole.

  16. Guidance on Developing Fee Programs Required by Clean Air Act Section 185 for the 1997 1-hour Ozone National Ambient Air Quality Standards (NAAQS)

    EPA Pesticide Factsheets

    This January 2010 memorandum provides additional guidance on fee collection programs for the 1997 1-hour ozone NAAQS, which are required as anti-backsliding measures during transition to the 1997 8-hour ozone standard.

  17. A Physiology-Based Model Describing Heterogeneity in Glucose Metabolism

    PubMed Central

    Maas, Anne H.; Rozendaal, Yvonne J. W.; van Pul, Carola; Hilbers, Peter A. J.; Cottaar, Ward J.; Haak, Harm R.; van Riel, Natal A. W.

    2014-01-01

    Background: Current diabetes education methods are costly, time-consuming, and do not actively engage the patient. Here, we describe the development and verification of the physiological model for healthy subjects that forms the basis of the Eindhoven Diabetes Education Simulator (E-DES). E-DES shall provide diabetes patients with an individualized virtual practice environment incorporating the main factors that influence glycemic control: food, exercise, and medication. Method: The physiological model consists of 4 compartments for which the inflow and outflow of glucose and insulin are calculated using 6 nonlinear coupled differential equations and 14 parameters. These parameters are estimated on 12 sets of oral glucose tolerance test (OGTT) data (226 healthy subjects) obtained from literature. The resulting parameter set is verified on 8 separate literature OGTT data sets (229 subjects). The model is considered verified if 95% of the glucose data points lie within an acceptance range of ±20% of the corresponding model value. Results: All glucose data points of the verification data sets lie within the predefined acceptance range. Physiological processes represented in the model include insulin resistance and β-cell function. Adjusting the corresponding parameters allows to describe heterogeneity in the data and shows the capabilities of this model for individualization. Conclusion: We have verified the physiological model of the E-DES for healthy subjects. Heterogeneity of the data has successfully been modeled by adjusting the 4 parameters describing insulin resistance and β-cell function. Our model will form the basis of a simulator providing individualized education on glucose control. PMID:25526760

  18. Fully Implantable Arterial Blood Glucose Device for Metabolic Research Applications in Rats for Two Months

    PubMed Central

    Brockway, Robert; Tiesma, Scott; Bogie, Heather; White, Kimberly; Fine, Megan; O’Farrell, Libbey; Michael, Mervyn; Cox, Amy; Coskun, Tamer

    2015-01-01

    Background: Chronic continuous glucose monitoring options for animal research have been very limited due to various technical and biological challenges. We provide an evaluation of a novel telemetry device for continuous monitoring of temperature, activity, and plasma glucose levels in the arterial blood of rats for up to 2 months. Methods: In vivo testing in rats including oral glucose tolerance tests (OGTTs) and intraperitoneal glucose tolerance tests (IPGTTs) and ex vivo waterbath testing were performed to evaluate acute and chronic sensor performance. Animal studies were in accordance with the guidelines for the care and use of laboratory animals and approved by the corresponding animal care and use committees (Data Sciences International, Eli Lilly). Results: Results demonstrated the ability to record continuous measurements for 75 days or longer. Bench testing demonstrated a high degree of linearity over a range of 20-850 mg/dL with R2 = .998 for linear fit and .999 for second order fit (n = 8 sensors). Evaluation of 6 rats over 28 days with 52 daily and OGTT test strip measurements each resulted in mean error of 3.8% and mean absolute relative difference of 16.6%. Conclusions: This device provides significant advantages in the quality and quantity of data that can be obtained relative to existing alternatives such as intermittent blood sampling. These devices provide the opportunity to expand the understanding of both glucose metabolism and homeostasis and to work toward improved therapies and cures for diabetes. PMID:26021562

  19. Statistical analysis and multi-instrument overview of the quasi-periodic 1-hour pulsations in Saturn's outer magnetosphere

    NASA Astrophysics Data System (ADS)

    Palmaerts, B.; Roussos, E.; Krupp, N.; Kurth, W. S.; Mitchell, D. G.; Yates, J. N.

    2016-06-01

    The in-situ exploration of the magnetospheres of Jupiter and Saturn has revealed different periodic processes. In particular, in the Saturnian magnetosphere, several studies have reported pulsations in the outer magnetosphere with a periodicity of about 1 h in the measurements of charged particle fluxes, plasma wave, magnetic field strength and auroral emissions brightness. The Low-Energy Magnetospheric Measurement System detector of the Magnetospheric Imaging Instrument (MIMI/LEMMS) on board Cassini regularly detects 1-hour quasi-periodic enhancements in the intensities of electrons with an energy range from a hundred keV to several MeV. We extend an earlier survey of these relativistic electron injections using 10 years of LEMMS observations in addition to context measurements by several other Cassini magnetospheric experiments. The one-year extension of the data and a different method of detection of the injections do not lead to a discrepancy with the results of the previous survey, indicating an absence of a long-term temporal evolution of this phenomenon. We identified 720 pulsed events in the outer magnetosphere over a wide range of latitudes and local times, revealing that this phenomenon is common and frequent in Saturn's magnetosphere. However, the distribution of the injection events presents a strong local time asymmetry with ten times more events in the duskside than in the dawnside. In addition to the study of their topology, we present a first statistical analysis of the pulsed events properties. The morphology of the pulsations shows a weak local time dependence which could imply a high-latitude acceleration source. We provide some clues that the electron population associated with this pulsed phenomenon is distinct from the field-aligned electron beams previously observed in Saturn's magnetosphere, but both populations can be mixed. We have also investigated the signatures of each electron injection event in the observations acquired by the Radio

  20. GOES Infrared and Reflectance 0-1 hour Lightning Initiation Indicators: Development and Initial Testing within a Convective Nowcasting System

    NASA Astrophysics Data System (ADS)

    Mecikalski, J. R.; Harris, R.; MacKenzie, W.; Durkee, P. A.; Iskenderian, H.; Bickmeier, L.; Nielsen, K. E.

    2010-12-01

    Within cumulus cloud fields that develop in conditionally unstable air masses, only a fraction of the cumuli may eventually develop into deep convection. Identifying which of these convective clouds most likely to generate lightning often starts with little more than a qualitative visual satellite analysis. The goal of this study is to identify the observed satellite infrared (IR) signatures associated with growing cumulus clouds prior to the first lightning strike, so-called lightning initiation (LI). This study quantifies the behavior of ten Geostationary Operational Environmental Satellite (GOES-12) IR interest fields in the 1-hour in advance of LI. A total of 172 lightning-producing storms that occurred during the 2009 convective season are manually tracked and studied over four regions: Northern Alabama, Central Oklahoma, the Kennedy Space Center and Washington D.C. Four-dimensional and cloud-to-ground lightning array data provide a total cloud lightning picture (in-cloud, cloud-to-cloud, cloud-to-air, cloud-to-ground) and thus precise LI points for each storm in both time and space. Statistical significance tests are conducted on observed trends for each of the ten LI fields to determine the unique information each field provides in terms of behavior prior to LI. Eight out of ten LI fields exhibited useful information at least 15 min in advance of LI, with 35 min being the average. Statistical tests on these eight fields are compared for separate large geographical areas. IR temperature thresholds are then determined as an outcome, which may be valuable when implementing a LI prediction algorithm into real-time satellite-based systems. The key LI indicators from GOES IR data (as well as 3.9 μm reflectance) will be presented. Beginning in 2010, the feasibility of using the satellite-based LI indicators found in the above analysis to forecast first lightning will be assessed within the Federal Aviation Administration’s (FAA) CoSPA nowcasting system. The goal

  1. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey

    2015-01-01

    Lightning one of the most dangerous weather-related phenomena, especially as many jobs and activities occur outdoors, presenting risk from a lightning strike. Cloud-to-ground (CG) lightning represents a considerable safety threat to people at airfields, marinas, and outdoor facilities-from airfield personnel, to people attending outdoor stadium events, on beaches and golf courses, to mariners, as well as emergency personnel. Holle et al. (2005) show that 90% of lightning deaths occurred outdoors, while 10% occurred indoors despite the perception of safety when inside buildings. Curran et al. (2000) found that nearly half of fatalities due to weather were related to convective weather in the 1992-1994 timeframe, with lightning causing a large component of the fatalities, in addition to tornadoes and flash flooding. Related to the aviation industry, CG lightning represents a considerable hazard to baggage-handlers, aircraft refuelers, food caterers, and emergency personnel, who all become exposed to the risk of being struck within short time periods while convective storm clouds develop. Airport safety protocols require that ramp operations be modified or discontinued when lightning is in the vicinity (typically 16 km), which becomes very costly and disruptive to flight operations. Therefore, much focus has been paid to nowcasting the first-time initiation and extent of lightning, both of CG and of any lightning (e.g, in-cloud, cloud-to-cloud). For this project three lightning nowcasting methodologies will be combined: (1) a GOESbased 0-1 hour lightning initiation (LI) product (Harris et al. 2010; Iskenderian et al. 2012), (2) a High Resolution Rapid Refresh (HRRR) lightning probability and forecasted lightning flash density product, such that a quantitative amount of lightning (QL) can be assigned to a location of expected LI, and (3) an algorithm that relates Pseudo-GLM data (Stano et al. 2012, 2014) to the so-called "lightning jump" (LJ) methodology (Shultz et al

  2. A novel test for IGT utilizing metabolite markers of glucose tolerance.

    PubMed

    Cobb, Jeff; Eckhart, Andrea; Perichon, Regis; Wulff, Jacob; Mitchell, Matthew; Adam, Klaus-Peter; Wolfert, Robert; Button, Eric; Lawton, Kay; Elverson, Robert; Carr, Bernadette; Sinnott, Margaret; Ferrannini, Ele

    2015-01-01

    The oral glucose tolerance test (OGTT) is the only method to diagnose patients having impaired glucose tolerance (IGT), but its use has diminished considerably in recent years. Metabolomic profiling studies have identified a number of metabolites whose fasting levels are associated with dysglycemia and type 2 diabetes. These metabolites may serve as the basis of an alternative test for IGT. Using the stable isotope dilution technique, quantitative assays were developed for 23 candidate biomarker metabolites. These metabolites were measured in fasting plasma samples taken just prior to an OGTT from 1623 nondiabetic subjects: 955 from the Relationship between Insulin Sensitivity and Cardiovascular Disease Study (RISC Study; 11.7% IGT) and 668 subjects from the Diabetes Mellitus and Vascular Health Initiative (DMVhi) cohort from the DEXLIFE project (11.8% IGT). The associations between metabolites, anthropometric, and metabolic parameters and 2hPG values were assessed by Pearson correlation coefficients and Random Forest classification analysis to rank variables for their ability to distinguish IGT from normal glucose tolerance (NGT). Multivariate logistic regression models for estimating risk of IGT were developed and evaluated using AUCs calculated from the corresponding ROC curves. A model based on the fasting plasma levels of glucose, α-hydroxybutyric acid, β-hydroxybutyric acid, 4-methyl-2-oxopentanoic acid, linoleoylglycerophosphocholine, oleic acid, serine and vitamin B5 was optimized in the RISC cohort (AUC = 0.82) and validated in the DMVhi cohort (AUC = 0.83). A novel, all-metabolite-based test is shown to be a discriminate marker of IGT. It requires only a single fasted blood draw and may serve as a more convenient surrogate for the OGTT or as a means of identifying subjects likely to be IGT.

  3. Short-Term Regulation of Lipocalin-2 but not RBP-4 During Oral Lipid Tolerance Test and Oral Glucose Tolerance Test.

    PubMed

    Schmid, A; Leszczak, S; Ober, I; Schäffler, A; Karrasch, T

    2016-02-01

    The postprandial regulation of lipocalin-2 and retinol binding protein-4 (RBP-4) by oral uptake of lipids and carbohydrates in healthy individuals has not yet been investigated. The regulation of lipocalin-2 and RBP-4 in 2 large cohorts of healthy volunteers during oral lipid tolerance test (OLTT; n=100) and oral glucose tolerance test (OGTT; n=100) was analyzed. One hundred healthy volunteers underwent OLTT and OGTT in an outpatient setting. Venous blood was drawn after 0, 2, 4, and 6 h in OLTT and after 0, 1, and 2 h in OGTT. In order to dissect carbohydrate-induced from lipid-induced effects, a novel OLTT solution completely free of carbohydrates and protein was applied. Subjects were characterized by anthropometric and laboratory parameters. Serum concentrations of lipocalin-2 and RBP-4 were measured by enzyme-linked immunosorbent assay (ELISA). Whereas RBP-4 levels remained unchanged during OGTT, lipocalin-2 concentrations significantly decreased during OGTT. During OLTT, RBP-4 levels were not influenced, whereas lipocalin-2 levels decreased significantly and stepwise. Fasting concentrations of RBP-4 were negatively correlated with BMI and waist-hip ratio, whereas lipocalin-2 levels were positively associated with BMI and waist-hip ratio. Female users of hormonal contraception had higher RBP-4 levels than females not on contraceptives. There is no significant short-term regulation of RBP-4 by orally ingested lipids or carbohydrates. Lipocalin-2 is downregulated after lipid and carbohydrate ingestion and this kind of regulation was not predicted by age, sex, triglycerides, glucose, or insulin levels.

  4. Risk of impaired glucose tolerance in normal weight hirsute women during four years observation.

    PubMed

    Andries, Magdalene; Glintborg, Dorte; Andersen, Marianne

    2010-08-01

    Hirsutism is a common disorder affecting 5-20% of women in reproductive age. Only limited follow-up data exist regarding the prognosis for glucose tolerance and metabolic risk factors in hirsutism. Sixty-nine Caucasian hirsute women underwent a clinical examination and an oral glucose tolerance test (OGTT) during 1997-2002 (baseline) and during 2003-2004 (re-evaluation). The observation period was (median; range) 4 (2-7) years. During re-evaluation, body mass index (BMI) was 24.9 (22.4-29.0) kg/m(2) and total Ferriman-Gallwey score was 10 (7-15) (median; 25-75% quartile). The women had unchanged BMI compared to baseline but increased fasting and 2 hour glucose levels. Impaired OGTT outcome during follow-up was seen in 14/66 (21.2%) women, 5/66 (7.6%) developed diabetes. Women who took oral contraceptives had a significantly decreased area under the curve (AUC) for insulin during follow-up, whereas AUC glucose levels increased. The present data supported a high risk of diabetes in only moderately overweight hirsute women.

  5. Glucose tolerance during pregnancy in Asian women.

    PubMed

    Samanta, A; Burden, M L; Burden, A C; Jones, G R

    1989-08-01

    The present study was aimed at examining differences in gestational diabetes mellitus (GDM) between two ethnic populations (immigrant Asians and indigenous White Caucasians) residing in Leicester, U.K. The study was divided into two parts: to determine the prevalence of GDM and to determine the level at which glycaemia may impose a risk to the mother and the foetus. Of a total of 12,005 pregnancies (4561 Asian and 7444 White Caucasian), over a 3-year period, 314 (6.8%) Asian and 504 (6.7%) White Caucasian were given a 75-g oral glucose tolerance test (OGTT) at 28-32 weeks for indications of 'large for date' pregnancies, hydramnios, glycosuria, a history of previous abortions, stillbirths, congenital abnormalities or glucose intolerance, and family history of diabetes. Abnormal glucose tolerance (AGT) was taken as a 2-h venous plasma glucose greater than or equal to 7.8 mmol/l which reverted to normal when formally tested during the puerperium (WHO criteria, 1985). AGT was found in 1.38% Asian and 0.87% White Caucasian pregnancies (P less than 0.01). This was further divided into impaired glucose tolerance (IGT) (2-h value 7.8-11.1 mmol/l) and gestational diabetes mellitus (GDM) (2-h value greater than or equal to 11.1 mmol/l). IGT was found in 1.2% Asian and 0.84% White Caucasian pregnancies (P less than 0.01), and GDM in 0.18% and 0.02% respectively (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Delphinidin-Rich Maqui Berry Extract (Delphinol®) Lowers Fasting and Postprandial Glycemia and Insulinemia in Prediabetic Individuals during Oral Glucose Tolerance Tests

    PubMed Central

    Alvarado, Jorge L.; Salgado, Ana-María; Lyon, Carolina; Vigil, Pilar

    2016-01-01

    Delphinidin anthocyanins have previously been associated with the inhibition of glucose absorption. Blood glucose lowering effects have been ascribed to maqui berry (Aristotelia chilensis) extracts in humans after boiled rice consumption. In this study, we aimed to explore whether a standardized delphinidin-rich extract from maqui berry (Delphinol) affects glucose metabolism in prediabetic humans based on glycemia and insulinemia curves obtained from an oral glucose tolerance test (OGTT) after a challenge with pure glucose. Volunteers underwent four consecutive OGTTs with at least one week washout period, in which different doses of Delphinol were administered one hour before glucose intake. Delphinol significantly and dose-dependently lowered basal glycemia and insulinemia. Lower doses delayed postprandial glycemic and insulinemic peaks, while higher doses reversed this tendency. Glycemia peaks were dose-dependently lowered, while insulinemia peaks were higher for the lowest dose and lower for other doses. The total glucose available in blood was unaffected by treatments, while the total insulin availability was increased by low doses and decreased by the highest dose. Taken together, these open exploratory results suggest that Delphinol could be acting through three possible mechanisms: by inhibition of intestinal glucose transporters, by an incretin-mediated effect, or by improving insulin sensitivity. PMID:28025651

  7. [Analysis on prevalence of physical activity time <1 hour and related factors in students aged 9-22 years in China, 2014].

    PubMed

    Wang, Z H; Dong, Y H; Song, Y; Yang, Z P; Ma, J

    2017-03-10

    Objective: To explore the prevalence of physical activity time <1 hour and related factors in students aged 9-22 years in China. Methods: A total of 220 159 students (110 039 boys and 110 120 girls) aged 9-22 years who completed the questionnaire of physical activity and lifestyle behaviors were selected from " 2014 National Physical Fitness and Health Surveillance" for the current study. All the participants were divided into 2 groups, i.e. physical activity time <1 hour and physical activity time ≥1 hour according the suggestion of Central Government, stratified by age and gender. χ(2) tests were used to compare the difference in the prevalence of physical activity time <1 hour between boys and girls in every age groups. Univariate and multivariate log-binomial regression models were used to explore the factors that influenced the prevalence of physical activity time <1 hour. Results: The boy's prevalence of physical activity time <1 hour was 73.3%, with the lowest (57.0%) in 9-years-old group, and highest (82.5%) in 18 years old group. The girl's prevalence of physical activity time <1 hour was 79.1%, with the lowest (60.1%) in 9-years-old group, and highest (89.8%) in 21 years old group. Overall, The prevalence of physical activity time <1 hour was significantly higher in girls than in boys (P<0.001), and the prevalence were significantly higher in girls than in boys in all the age groups (P<0.001), and it was observed that the prevalence of physical activity <1 hour increased with age in both boys and girls (P<0.001). Multivariate log-binomial regression model found that being girl (PR=1.05, 95%CI: 1.05-1.06), parents' disliking children to participate physical activity (PR=1.08, 95% CI: 1.07-1.09), heavy homework (PR=1.13, 95% CI: 1.12-1.14), long homework time (PR =1.08, 95%CI: 1.07-1.08), long time spending on electronic screen watching (PR=1.01, 95%CI: 1.00-1.01) and disliking physical class (PR=1.11, 95%CI: 1.10-1.12) could be the risk factors for

  8. Dietary Fatty Acids Differentially Associate with Fasting Versus 2-Hour Glucose Homeostasis: Implications for The Management of Subtypes of Prediabetes

    PubMed Central

    Guess, Nicola; Perreault, Leigh; Kerege, Anna; Strauss, Allison; Bergman, Bryan C.

    2016-01-01

    Over-nutrition has fuelled the global epidemic of type 2 diabetes, but the role of individual macronutrients to the diabetogenic process is not well delineated. We aimed to examine the impact of dietary fatty acid intake on fasting and 2-hour plasma glucose concentrations, as well as tissue-specific insulin action governing each. Normoglycemic controls (n = 15), athletes (n = 14), and obese (n = 23), as well as people with prediabetes (n = 10) and type 2 diabetes (n = 11), were queried about their habitual diet using a Food Frequency Questionnaire. All subjects were screened by an oral glucose tolerance test (OGTT) and studied using the hyperinsulinemic/euglycemic clamp with infusion of 6,62H2-glucose. Multiple regression was performed to examine relationships between dietary fat intake and 1) fasting plasma glucose, 2) % suppression of endogenous glucose production, 3) 2-hour post-OGTT plasma glucose, and 4) skeletal muscle insulin sensitivity (glucose rate of disappearance (Rd) and non-oxidative glucose disposal (NOGD)). The %kcal from saturated fat (SFA) was positively associated with fasting (β = 0.303, P = 0.018) and 2-hour plasma glucose (β = 0.415, P<0.001), and negatively related to % suppression of hepatic glucose production (β = -0.245, P = 0.049), clamp Rd (β = -0.256, P = 0.001) and NOGD (β = -0.257, P = 0.001). The %kcal from trans fat was also negatively related to clamp Rd (β = -0.209, P = 0.008) and NOGD (β = -0.210, P = 0.008). In contrast, the %kcal from polyunsaturated fat (PUFA) was negatively associated with 2-hour glucose levels (β = -0.383, P = 0.001), and positively related to Rd (β = 0.253, P = 0.007) and NOGD (β = 0.246, P = 0.008). Dietary advice to prevent diabetes should consider the underlying pathophysiology of the prediabetic state. PMID:26999667

  9. Is a family history of diabetes associated with an increased level of cardiovascular risk factors? Studies in healthy people and in subjects with different degree of glucose intolerance.

    PubMed

    Quatraro, A; Giugliano, D; De Rosa, N; Minei, A; Ettorre, M; Donzella, C; Saccomanno, F; Ceriello, A

    1993-01-01

    In order to evaluate whether the presence of a positive family history of diabetes (PFH) may have a negative impact on both glucose metabolism and cardiovascular risk factors, we studied parameters of carbohydrate metabolism (fasting and 2h-plasma glucose, HbA1c) and beta-cell function (fasting insulin and C-peptide), as well as the levels of some established cardiovascular risk factors (total cholesterol and triglycerides, HDL-cholesterol, blood pressure) in 729 subjects who were seen within the frame of a Regional Health Program in Taranto, South Italy. According to the NDDG criteria, 147 men and 235 women had normal glucose tolerance, 54 men and 66 women non-diagnostic OGTT, 65 men and 79 women impaired glucose tolerance, and 45 men and 58 women newly-diagnosed Type 2 diabetes. There was a continuous increase of PFH across the categories of glucose intolerance (p < 0.001). Subjects with PFH were younger (4 years on the average) than subjects without PFH. After adjustment for age, there was no difference in the clinical and metabolic parameters considered across the categories of glucose tolerance between subjects with or without PFH. Only in OGTT-diagnosed diabetics, was the presence of PFH associated with significantly greater levels of total cholesterol and 2h-plasma glucose, as well as a trend for triglycerides and HbA1c to be higher. There was a continuous increase in fasting glucose, HbA1c, insulin and C-peptide across the categories; however, the C-peptide/insulin molar ratio was lowest in OGTT-diagnosed diabetics. There was a graded and significant increase in the levels of cardiovascular risk factors across the categories.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Acute postexercise effects of concentric and eccentric exercise on glucose tolerance.

    PubMed

    Cook, Matthew David; Myers, Stephen David; Kelly, John Stephen Michael; Willems, Mark Elisabeth Theodorus

    2015-02-01

    Impaired glucose tolerance was shown to be present 48 hr following muscle-damaging eccentric exercise. We examined the acute effect of concentric and muscle-damaging eccentric exercise, matched for intensity, on the responses to a 2-hr 75-g oral glucose tolerance test (OGTT). Ten men (27 ± 9 years, 178 ± 7 cm, 75 ± 11 kg, VO₂max: 52.3 ± 7.3 ml · kg⁻¹ · min⁻¹) underwent three OGTTs after an overnight 12 hr fast: rest (control), 40-min (5 × 8-min with 2-min interbout rest) of concentric (level running, 0%, CON) or eccentric exercise (downhill running, -12%, ECC). Running intensity was matched at 60% of maximal metabolic equivalent. Maximal isometric force of m. quadriceps femoris of both legs was measured before and after the running protocols. Downhill running speed was higher (level: 9.7 ± 2.1, downhill: 13.8 ± 3.2 km · hr⁻¹, p < .01). Running protocols had similar VO₂max (p = .59), heart rates (p = .20) and respiratory exchange ratio values (p = .74) indicating matched intensity and metabolic demands. Downhill running resulted in higher isometric force deficits (level: 3.0 ± 6.7, downhill: 17.1 ± 7.3%, p < .01). During OGTTs, area-under-the-curve for plasma glucose (control: 724 ± 97, CON: 710 ± 77, ECC: 726 ± 72 mmol · L⁻¹ · 120 min, p = .86) and insulin (control: 24995 ± 11229, CON: 23319 ± 10417, ECC: 21842 ± 10171 pmol · L⁻¹ · 120 min, p = .48), peak glucose (control: 8.1 ± 1.3, CON: 7.7 ± 1.2, ECC: 7.7 ± 1.1 mmol · L⁻¹, p = .63) and peak insulin levels (control: 361 ± 188, CON: 322 ± 179, ECC: 299 ± 152 pmol · L⁻¹, p = .30) were similar. It was concluded that glucose tolerance and the insulin response to an OGTT were not changed immediately by muscle-damaging eccentric exercise.

  11. In vivo interstitial glucose characterization and monitoring in the skin by ATR-FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Skrebova Eikje, Natalja

    2011-03-01

    Successful development of real-time non-invasive glucose monitoring would represent a major advancement not only in the treatment and management of patients with diabetes mellitus and carbohydrate metabolism disorders, but also for understanding in those biochemical, metabolic and (patho-)physiological processes of glucose at the molecular level in vivo. Here, ATR-FTIR spectroscopy technique has been challenged not only for in vivo measurement of interstitial glucose levels, but also for their non-invasive molecular qualitative and quantitative comparative characterization in the skin tissue. The results, based on calculated mean values of determined 5 glucose-specific peaks in the glucose-related 1000-1160 cm-1 region, showed intra- and inter-subject differences in interstitial glucose activity levels with their changes at different times and doses of OGTT, while raising questions about the relationships between interstitial and blood glucose levels. In conclusion, the introduction of ATR-FTIR spectroscopy technique has opened up an access to the interstitial fluid space in the skin tissue for interstitial glucose characterization and monitoring in vivo. Though interstitial versus blood glucose monitoring has different characteristics, it can be argued that accurate and precise measurements of interstitial glucose levels may be more important clinically.

  12. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... NAAQS to the 1997 8-hour NAAQS and what are the anti-backsliding provisions? 51.905 Section 51.905... National Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 1997 8... implement the applicable requirements as defined in § 51.900(f), except as provided in paragraph...

  13. 40 CFR 60.1265 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... geometric average concentrations of sulfur dioxide emissions. If you are monitoring the percent reduction of... daily geometric average percent reduction of potential sulfur dioxide emissions. (c) If you operate a... Continuous Emission Monitoring § 60.1265 How do I convert my 1-hour arithmetic averages into the...

  14. Serum progranulin concentrations are not responsive during oral lipid tolerance test and oral glucose tolerance test.

    PubMed

    Schmid, A; Leszczak, S; Ober, I; Schäffler, A; Karrasch, T

    2015-07-01

    The postprandial regulation of progranulin by oral uptake of lipids and carbohydrates in healthy individuals has not yet been investigated. The regulation of progranulin in 2 large cohorts of healthy volunteers during oral lipid tolerance test (OLTT; n=100) and oral glucose tolerance test (OGTT; n=100) was analyzed. One hundred healthy volunteers underwent OLTT and OGTT in an outpatient setting. Venous blood was drawn at 0 hours (h) (fasting) and at 2, 4, and 6 h in OLTT or 1 and 2 h in OGTT. A novel OLTT solution completely free of carbohydrates and protein was applied. Subjects were characterized by anthropometric and laboratory parameters. Serum concentrations of progranulin were measured by enzyme-linked immunosorbent assay (ELISA). Circulating progranulin levels remained unchanged during OLTT and OGTT. Fasting progranulin levels ranged between 31.3±8.7 and 40.6±7.7 ng/ml and were not different in subgroups addressing BMI, gender, family history, smoking habits, and hormonal contraception. There was a reciprocal correlation of progranulin with HDL (negative) and LDL cholesterol levels (positive). In healthy adults, fasting and postprandial circulating progranulin levels are not different in BMI subgroups. Oral uptake of carbohydrates and lipids does not influence circulating progranulin levels in a short-term manner. A postprandial and short-term regulation of this adipokine is absent, at least in healthy subjects. There is a negative correlation of progranulin with HDL cholesterol, but a positive correlation with LDL cholesterol. This reciprocal association might be of physiological importance for an individual's atherosclerotic risk.

  15. Dynamic contrast-enhanced magnetic resonance imaging of osseous spine metastasis before and 1 hour after high-dose image-guided radiation therapy.

    PubMed

    Lis, Eric; Saha, Atin; Peck, Kyung K; Zatcky, Joan; Zelefsky, Michael J; Yamada, Yoshiya; Holodny, Andrei I; Bilsky, Mark H; Karimi, Sasan

    2017-01-01

    OBJECTIVE High-dose image-guided radiation therapy (HD IGRT) has been instrumental in mitigating some limitations of conventional RT. The recent emergence of dynamic contrast-enhanced (DCE) MRI to investigate tumor physiology can be used to verify the response of human tumors to HD IGRT. The purpose of this study was to evaluate the near-immediate effects of HD IGRT on spine metastases through the use of DCE MRI perfusion studies. METHODS Six patients with spine metastases from prostate, thyroid, and renal cell carcinoma who underwent HD IGRT were studied using DCE MRI prior to and 1 hour after HD IGRT. The DCE perfusion parameters plasma volume (Vp) and vascular permeability (Ktrans) were measured to assess the near-immediate and long-term tumor response. A Mann-Whitney U-test was performed to compare significant changes (at p ≤ 0.05) in perfusion parameters before and after RT. RESULTS The authors observed a precipitous drop in Vp within 1 hour of HD IGRT, with a mean decrease of 65.2%. A significant difference was found between Vp values for before and 1 hour after RT (p ≤ 0.05). No significant change was seen in Vp (p = 0.31) and Ktrans (p = 0.1) from 1 hour after RT to the first follow-up. CONCLUSIONS The data suggest that there is an immediate effect of HD IGRT on the vascularity of spine metastases, as demonstrated by a precipitous decrease in Vp. The DCE MRI studies can detect such changes within 1 hour after RT, and findings are concordant with existing animal models.

  16. Decrease of serum S100B during an oral glucose tolerance test correlates inversely with the insulin response.

    PubMed

    Steiner, Johann; Bernstein, Hans-Gert; Schiltz, Kolja; Haase, Thekla; Meyer-Lotz, Gabriela; Dobrowolny, Henrik; Müller, Ulf J; Martins-de-Souza, Daniel; Borucki, Katrin; Schroeter, Matthias L; Isermann, Berend; Bogerts, Bernhard; Westphal, Sabine

    2014-01-01

    Increased S100B serum levels have been considered as a marker of glial pathology, brain damage, and blood-brain-barrier impairment. However, S100B expression has also been detected outside the nervous system, suggesting that altered S100B serum levels may not exclusively reflect brain-specific pathologies. Notably, S100B secretion in adipocytes seems to be down-regulated by insulin, and up-regulated by stress and fasting. Therefore, we assumed that dynamic changes of S100B could be observed by challenging healthy subjects with an oral glucose tolerance test (OGTT). OGTT was performed in 17 healthy adult test persons (9 male and 8 female). Apart from S100B, glucose, free fatty acids, insulin, C-peptide, and cortisol were determined in all samples after an overnight fast (0 h), as well as 1h and 2h after ingestion of 75 g glucose. Mean S100B concentrations decreased about 20% during the first hour after glucose ingestion (P<0.001). This decrease of S100B levels was not related to the declining morning peak of cortisol. However, the decrease of serum-S100B 1h after glucose ingestion correlated inversely with the respective changes of serum-insulin (r = -0.484, P=0.049) and serum-C-peptide (r = -0.570, P = 0.017). Our study suggests an inverse correlation between insulin secretion and S100B release after a standardized OGTT. Additional experiments, including the administration of insulin and the measurement of other food intake-related factors are important to ascertain an insulin-regulated S100B release in vivo. To improve comparability between clinical studies assessing conditions with rather mild changes of serum S100B, blood should be taken in a more standardized way (e.g., after fasting overnight).

  17. Urinary C peptide creatinine ratio in pregnant women with normal glucose tolerance and type 1 diabetes: evidence for insulin secretion

    PubMed Central

    Markoska, Ankica; Valaiyapathi, Rajalakshmi; Thorn, Chloe; Dornhorst, Anne

    2017-01-01

    Hypothesis In pregnancy, urinary C peptide creatinine ratio (UCPCR) reflects endogenous insulin secretion in women with normal glucose tolerance and type 1 diabetes. Research design and methods UCPCR and serum C peptide were measured in 90 glucose-tolerant women at 0 and 120 min during a 75 g oral glucose tolerance test (OGTT) at 28 weeks of gestation. UCPCR was measured in 2 samples obtained over 10 weeks apart in 7 pregnant women with longstanding type 1 diabetes. Results UCPCROGTT and serum C peptideOGTT of glucose-tolerant women were significantly correlated at 0 and 120 min (rs0.675, 0.541 respectively, p<0.0001). All 7 pregnant women with type 1 diabetes had detectable first sample UCPCR (median (range) 49 (6–1038) pmol/mmol) that rose in 6 women by 477 (29–1491) pmol/mmol. Conclusions Detectable UCPCR in pregnant women with normal glucose tolerance and type 1 diabetes is likely to reflect endogenous insulin secretion and hence β-cell activity. PMID:28090333

  18. Exogenous thyroxine improves glucose intolerance in insulin-resistant rats.

    PubMed

    Vazquez-Anaya, Guillermo; Martinez, Bridget; Soñanez-Organis, José G; Nakano, Daisuke; Nishiyama, Akira; Ortiz, Rudy M

    2017-03-01

    Both hypothyroidism and hyperthyroidism are associated with glucose intolerance, calling into question the contribution of thyroid hormones (TH) on glucose regulation. TH analogues and derivatives may be effective treatment options for glucose intolerance and insulin resistance (IR), but their potential glucoregulatory effects during conditions of impaired metabolism are not well described. To assess the effects of thyroxine (T4) on glucose intolerance in a model of insulin resistance, an oral glucose tolerance test (oGTT) was performed on three groups of rats (n = 8): (1) lean, Long Evans Tokushima Otsuka (LETO), (2) obese, Otsuka Long Evans Tokushima Fatty (OLETF) and (3) OLETF + T4 (8.0 µg/100 g BM/day × 5 weeks). T4 attenuated glucose intolerance by 15% and decreased IR index (IRI) by 34% in T4-treated OLETF compared to untreated OLETF despite a 31% decrease in muscle Glut4 mRNA expression. T4 increased the mRNA expressions of muscle monocarboxylate transporter 10 (Mct10), deiodinase type 2 (Di2), sirtuin 1 (Sirt1) and uncoupling protein 2 (Ucp2) by 1.8-, 2.2-, 2.7- and 1.4-fold, respectively, compared to OLETF. Activation of AMP-activated protein kinase (AMPK) and insulin receptor were not significantly altered suggesting that the improvements in glucose intolerance and IR were independent of enhanced insulin-mediated signaling. The results suggest that T4 treatment increased the influx of T4 in skeletal muscle and, with an increase of DI2, increased the availability of the biologically active T3 to upregulate key factors such SIRT1 and UCP2 involved in cellular metabolism and glucose homeostasis.

  19. An oral lipid challenge and acute intake of caffeinated coffee additively decrease glucose tolerance in healthy men.

    PubMed

    Beaudoin, Marie-Soleil; Robinson, Lindsay E; Graham, Terry E

    2011-04-01

    Lipid-induced insulin resistance has been investigated primarily with i.v. infusions, and caffeine-induced insulin resistance, with alkaloid caffeine. The effects of orally consumed lipids and coffee have not been established and to our knowledge have never been simultaneously investigated. The goals of this study were to determine whether an oral lipid challenge and caffeinated coffee would disrupt glucose homeostasis and to characterize their respective incretin responses. It was hypothesized that oral ingestion of saturated lipids would impair glucose tolerance and that caffeinated coffee would further hinder glucose management. Ten young, healthy males participated in 5 trials in a randomized, cross-over design. At time 0 h, they underwent an oral fat tolerance test (OFTT: 1 g lipid/kg body weight) or consumed water, followed 5 h later by caffeinated (5 mg/kg) coffee, decaffeinated coffee, or water. At 6 h, volunteers underwent an oral glucose tolerance test (OGTT). Consumption of the OFTT increased glucose concentrations (P < 0.05) after a subsequent OGTT. At 7 h, caffeinated coffee produced the highest glucose concentrations (P < 0.05). Glucagon-like peptide-1 active (GLP-1a) and glucose-dependent insulinotropic polypeptide (GIP) were both increased for up to 6 h in all OFTT trials (P < 0.05). Compared to all other treatments, caffeinated and decaffeinated coffee produced higher GLP-1a response at 6.25 h (P < 0.05), whereas only caffeinated coffee increased GIP secretion (P < 0.05). These results show that oral consumption of lipids and caffeinated coffee can independently and additively decrease glucose tolerance. Incretin hormones could explain at least in part this impaired glucose homeostasis.

  20. Low-Dose-Rate Irradiation for 1 Hour Induces Protection Against Lethal Radiation Doses but Does Not Affect Life Span of DBA/2 Mice

    PubMed Central

    Altaner, Čestmír; Altanerova, Veronika; Ebbesen, Peter; Pettersen, Erik O.

    2016-01-01

    Prior findings showed that serum from DBA/2 mice that had been given whole-body irradiation for 1 hour at a low dose rate (LDR) of 30 cGy/h induced protection against radiation in reporter cells by a mechanism depending on transforming growth factor β3 and inducible nitric oxide synthase activity. In the present study, the effect of the 1 hour of LDR irradiation on the response of the preirradiated mice to a subsequent lethal dose and on the life span is examined. These DBA/2 mice were prime irradiated for 1 hour at 30 cGy/h. Two experiments with 9 and 9.5 Gy challenge doses given 6 weeks after priming showed increased survival in primed mice compared to unprimed mice followed up to 225 and 81 days after challenge irradiation, respectively. There was no overall significant difference in life span between primed and unprimed mice when no challenge irradiation was given. The males seemed to have a slight increase in lifespan after priming while the opposite was seen for the females. PMID:27867323

  1. Metabolic syndrome and the early detection of impaired glucose tolerance among professionals living in Beijing, China: a cross sectional study

    PubMed Central

    2013-01-01

    Background The purpose of this study is to investigate the association of metabolic syndrome (MS) and its components with the risk of impaired glucose tolerance (IGT) in high risk urban professionals. The goal is to improve the selection of candidates who would most benefit from an oral glucose tolerance test (OGTT). Methods This is a cross sectional study in which MS was identified by both the definitions proposed by the National Cholesterol Education Program (NCEP) and the International Diabetes Federation (IDF). Results There were 928 eligible subjects in the study, and 23.9% of them failed in OGTT. The odds ratio of IGT was increased 3.16-fold for MS defined by the NCEP criteria and 2.79-fold for the hyperglycemia factor alone. Both MS and hyperglycemia were shown to be acceptable measures to discriminate subjects with IGT from those with normal glucose tolerance (NGT). The clustering of any 1, 2, or ≥3 metabolic components resulted in increased odds ratios for IGT: i.e., 1.71, 2.38 and 5.92, respectively. Even without hyperglycemia in the cluster, an increased odds ratio was still observed. The risk of IGT increased dramatically when the fasting plasma glucose and waist circumference were both at their highest defined level. Conclusions MS and its components are associated with the increased risk of IGT. People with MS, one of its components, especially hyperglycemia and central obesity, or a cluster of its components are strong candidates for an OGTT in order to achieve early cost-effective detection of IGT. PMID:24499585

  2. The 13C-Glucose Breath Test for Insulin Resistance Assessment in Adolescents: Comparison with Fasting and Post-Glucose Stimulus Surrogate Markers of Insulin Resistance

    PubMed Central

    Maldonado-Hernández, Jorge; Martínez-Basila, Azucena; Salas-Fernández, Alejandra; Navarro-Betancourt, José R.; Piña-Aguero, Mónica I.; Bernabe-García, Mariela

    2016-01-01

    Objective: To evaluate the use of the 13C-glucose breath test (13C-GBT) for insulin resistance (IR) detection in adolescents through comparison with fasting and post-glucose stimulus surrogates. Methods: One hundred thirty-three adolescents aged between 10 and 16 years received an oral glucose load of 1.75 g per kg of body weight dissolved in 150 mL of water followed by an oral dose of 1.5 mg/kg of U-13C-Glucose, without a specific maximum dose. Blood samples were drawn at baseline and 120 minutes, while breath samples were obtained at baseline and at 30, 60, 90, 120, 150, and 180 minutes. The 13C-GBT was compared to homeostasis model assessment (HOMA) IR (≥p95 adjusted by gender and age), fasting plasma insulin (≥p90 adjusted by gender and Tanner stage), results of 2-h oral glucose tolerance test (OGTT), insulin levels (≥65 μU/mL) in order to determine the optimal cut-off point for IR diagnosis. Results: 13C-GBT data, expressed as adjusted cumulative percentage of oxidized dose (A% OD), correlated inversely with fasting and post-load IR surrogates. Sexual development alters A% OD results, therefore individuals were stratified into pubescent and post-pubescent. The optimal cut-off point for the 13C-GBT in pubescent individuals was 16.3% (sensitivity=82.8% & specificity=60.6%) and 13.0% in post-pubescents (sensitivity=87.5% & specificity=63.6%), when compared to fasting plasma insulin. Similar results were observed against HOMA and 2-h OGTT insulin. Conclusion: The 13C-GBT is a practical and non-invasive method to screen for IR in adolescents with reasonable sensitivity and specificity. PMID:27354200

  3. Immunoneutralization of endogenous glucagon reduces hepatic glucose output and improves long-term glycemic control in diabetic ob/ob mice.

    PubMed

    Sørensen, Heidi; Brand, Christian L; Neschen, Susanne; Holst, Jens Juul; Fosgerau, Keld; Nishimura, Erica; Shulman, Gerald I

    2006-10-01

    In type 2 diabetes, glucagon levels are elevated in relation to the prevailing insulin and glucose levels. The relative hyperglucagonemia is linked to increased hepatic glucose output (HGO) and hyperglycemia. Antagonizing the effects of glucagon is therefore considered an attractive target for treatment of type 2 diabetes. In the current study, effects of eliminating glucagon signaling with a glucagon monoclonal antibody (mAb) were investigated in the diabetic ob/ob mouse. Acute effects of inhibiting glucagon action were studied by an oral glucose tolerance test (OGTT) and by measurement of HGO. In addition, the effects of subchronic (5 and 14 days) glucagon mAb treatment on plasma glucose, insulin, triglycerides, and HbA1c (A1C) levels were investigated. Glucagon mAb treatment reduced the area under the curve for glucose after an OGTT, reduced HGO, and increased the rate of hepatic glycogen synthesis. Glucagon mAb treatment for 5 days lowered plasma glucose and triglyceride levels, whereas 14 days of glucagon mAb treatment reduced A1C. In conclusion, acute and subchronic neutralization of endogenous glucagon improves glycemic control, thus supporting the contention that glucagon antagonism may represent a beneficial treatment of diabetes.

  4. Effectiveness of Medium-Chain Triglyceride Oil Therapy in Two Japanese Citrin-Deficient Siblings: Evaluation Using Oral Glucose Tolerance Tests.

    PubMed

    Otsuka, Hiroki; Sasai, Hideo; Abdelkreem, Elsayed; Kawamoto, Norio; Kawamoto, Minako; Kamiya, Toshiya; Tanimoto, Yasuo; Kikuchi, Atsuo; Kure, Shigeo; Numakura, Chikahiko; Hayasaka, Kiyoshi; Fukao, Toshiyuki

    2016-01-01

    Citrin deficiency, an inherited defect of the liver-type mitochondrial aspartate/glutamate carrier isoform (citrin), may cause impairment of glycolysis because of an increase in the cytosolic NADH/NAD(+) ratio. We report a Japanese boy whose main complaint was recurrent hypoglycemic episodes. He was suspected as having citrin deficiency because of his peculiar preference for protein- and fat-rich food. His young sister also had a similar food preference. Both siblings were diagnosed with citrin deficiency by genetic analysis. The brother and sister underwent an oral glucose tolerance test (OGTT) at 10 and 7 yr of age, respectively. Blood glucose, ammonia, lactic acid, pyruvic acid, and insulin levels were monitored before starting the test, and then every 30 min. During this test, they maintained blood glucose levels until 180 min. At 210 min, they experienced vomiting, feeling ill, and decreased blood glucose levels (2.9 and 2.8 mmol/l in the brother and sister, respectively). The sister and brother recovered uneventfully by intravenous glucose injection. In a second OGTT, 4 months after medium-chain triglyceride (MCT) oil supplementation, they had no major symptoms and normal glucose levels were maintained, even after 240 min. Additionally, after MCT oil therapy, their food preference slightly changed as they started eating more carbohydrates. Our OGTT data suggest excess carbohydrate intake has adverse consequences in patients with citrin deficiency, including hypoglycemia after a few hours. MCT oil therapy may be effective in preventing such hypoglycemia and improving metabolic derangement, even during the so-called apparently healthy period.

  5. Lack of TRPM2 Impaired Insulin Secretion and Glucose Metabolisms in Mice

    PubMed Central

    Uchida, Kunitoshi; Dezaki, Katsuya; Damdindorj, Boldbaatar; Inada, Hitoshi; Shiuchi, Tetsuya; Mori, Yasuo; Yada, Toshihiko; Minokoshi, Yasuhiko; Tominaga, Makoto

    2011-01-01

    OBJECTIVE TRPM2 is a Ca2+-permeable nonselective cation channel activated by adenosine dinucleotides. We previously demonstrated that TRPM2 is activated by coapplication of heat and intracellular cyclic adenosine 5′-diphosphoribose, which has been suggested to be involved in intracellular Ca2+ increase in immunocytes and pancreatic β-cells. To clarify the involvement of TRPM2 in insulin secretion, we analyzed TRPM2 knockout (TRPM2-KO) mice. RESEARCH DESIGN AND METHODS Oral and intraperitoneal glucose tolerance tests (OGTT and IPGTT) were performed in TRPM2-KO and wild-type mice. We also measured cytosolic free Ca2+ in single pancreatic cells using fura-2 microfluorometry and insulin secretion from pancreatic islets. RESULTS Basal blood glucose levels were higher in TRPM2-KO mice than in wild-type mice without any difference in plasma insulin levels. The OGTT and IPGTT demonstrated that blood glucose levels in TRPM2-KO mice were higher than those in wild-type mice, which was associated with an impairment in insulin secretion. In isolated β-cells, smaller intracellular Ca2+ increase was observed in response to high concentrations of glucose and incretin hormone in TRPM2-KO cells than in wild-type cells. Moreover, insulin secretion from the islets of TRPM2-KO mice in response to glucose and incretin hormone treatment was impaired, whereas the response to tolbutamide, an ATP-sensitive potassium channel inhibitor, was not different between the two groups. CONCLUSIONS These results indicate that TRPM2 is involved in insulin secretion stimulated by glucose and that further potentiated by incretins. Thus, TRPM2 may be a new target for diabetes therapy. PMID:20921208

  6. Detection of glycemic abnormalities in adolescents with beta thalassemia using continuous glucose monitoring and oral glucose tolerance in adolescents and young adults with β-thalassemia major: Pilot study

    PubMed Central

    Soliman, Ashraf T.; Yasin, Mohamed; El-Awwa, Ahmed; De Sanctis, Vincenzo

    2013-01-01

    Background: Both insulin deficiency and resistance are reported in patients with β-thalassemia major (BTM). The use of continuous blood glucose monitoring (CGM), among the different methods for early detection of glycemic abnormalities, has not been studied thoroughly in these adolescents. Materials and Methods: To assess the oralglucose tolerance (OGT) and 72-h continuous glucose concentration by the continuous glucose monitoring system (CGMS) and calculate homeostatic model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI) was conducted in 16 adolescents with BTM who were receiving regular blood transfusions every 2-4 weeks and iron-chelation therapy since early childhood. Results: Sixteen adolescents with BTM (age: 19.75 ± 3 years) were investigated. Using OGTT, (25%) had impaired fasting blood (plasma) glucose concentration (BG) (>5.6 mmol/L). 2-h after the glucose load, one of them had BG = 16.2 mmol/L (diabetic) and two had impaired glucose tolerance (IGT) (BG > 7.8 and <11.1 mmol/L). Monitoring the maximum (postprandial) BG using CGMS,4 adolescents were diagnosed with diabetes (25%) (BG >11.1 mmol/L) and 9 with IGT (56%). HOMA and QUICKI revealed levels <2.6 (1.6 ± 0.8) and >0.33 (0.36 ± 0.03), respectively, ruling out significant insulin resistance in these adolescents. There was a significant negative correlation between the β-cell function (B%) on one hand and the fasting and the 2-h BG (r=−0.6, and − 0.48, P < 0.01, respectively) on the other hand. Neither fasting serum insulin nor c-peptide concentrations were correlated with fasting BG or ferritin levels. The average and maximum blood glucose levels during CGM were significantly correlated with the fasting BG (r = 0.68 and 0.39, respectively, with P < 0.01) and with the BG at 2-hour after oral glucose intake (r = 0.87 and 0.86 respectively, with P < 0.001). Ferritin concentrations were correlated with the fasting BG and the 2-h blood glucose levels in the OGTT (r

  7. Beyond glucose: metabolic shifts in responses to the effects of the oral glucose tolerance test and the high-fructose diet in rats.

    PubMed

    Lin, Shuhai; Yang, Zhu; Liu, Hongde; Tang, Leihan; Cai, Zongwei

    2011-05-01

    High-fructose diet-fed rats as one of the insulin resistant models was used widely for understanding the mechanisms of type 2 diabetes mellitus. Systems-level metabolic profiling of the rat model, however, has not been deciphered clearly. To address this issue, mass spectrometry-based metabolomics was employed to unlock the metabolic snapshots of the oral glucose tolerance test (oGTT) effect in either healthy or diabetic rats, as well as to delineate the metabolic signatures in tissues of rats fed with high-fructose diet. Several differentiating metabolites were highlighted to reveal the metabolic perturbation of the oGTT effects in healthy and diabetic rats, which involved amino acid biosynthesis, polyunsaturated fatty acids, phospholipids and purine metabolism. Surprisingly, the patterns of relationships for the metabolic phenotypes by using data mining revealed that glucose ingestion might induce the healthy group to display its trajectory towards diabetic status, while only a very slight influence was observed on the high-fructose diet-fed rats 120 min after glucose ingestion. The data treatment for liver, skeletal muscle and brain tissues suggested that oxidative stress, such as lipid peroxidation and the declined antioxidant, the elevated amino acids and the perturbation of fatty acids, were caused by the high-fructose diet in liver and skeletal muscle tissues. On the other hand, the up-regulation in purine biosynthesis and the decreased concentrations for amino acids were observed in the cerebral cortex and hippocampus tissues. Collectively, the obtained results might provide a new insight not only for the impairment of glucose tolerance but also for the dietary style in rats.

  8. Impaired glucose tolerance in pediatric burn patients at discharge from the acute hospital stay

    PubMed Central

    Fram, Ricki Y.; Cree, Melanie G.; Wolfe, Robert R.; Barr, David; Herndon, David N.

    2013-01-01

    Objective Hyperglycemia, secondary to the hypermetabolic stress response, is a common occurrence after thermal injury. This stress response has been documented to persist up to 9 months post burn. The purpose of this study was to measure insulin sensitivity in severely burned children prior to discharge when wounds are 95% healed. Methods Twenty-four children, aged 4–17 years, with burns ≥ 40% total body surface area (TBSA) underwent a 2 hour oral glucose tolerance test (OGTT) prior to discharge from the acute pediatric burn unit. Plasma glucose and insulin levels, as well as the Homeostasis Model Assessment for Insulin Resistance (HOMAIR) were compared to published OGTT data from healthy, non-burned children. Results There was a significant difference between severely burned children and non-burned, healthy children with respect to the HOMAIR. Severely burned children had a HOMAIR of 3.53±1.62 compared to the value in non-burned healthy children was 1.28±0.16 (p<0.05). Conclusion Insulin resistance secondary to the hypermetabolic stress response persists in severely burned children when burn wounds are at least 95% healed. The results of this study warrant future investigations into therapeutic options for the burned child during the rehabilitative phase of their care after injury. PMID:20634704

  9. Lucica MI urinary myoinositol kit: a new diagnostic test for diabetes mellitus and glucose intolerance.

    PubMed

    Yamakoshi, Masaru; Kawazu, Shoji

    2008-01-01

    Diabetes mellitus is a growing healthcare problem internationally, and poses a major burden from both a individual and societal perspective. Diabetes causes potentially life-threatening complications that are preventable if the disease is detected early and appropriate interventions are put in place. Early detection is therefore imperative for preventing diabetes-related morbidity and mortality. Current methods of detection, including the oral glucose tolerance test (OGTT), and measures of fasting plasma glucose, glycated hemoglobin (HbA(1c)), or glycated albumin, can be time-consuming and uncomfortable for patients. Myoinositol can be measured in urine and has been found to be elevated in patients with diabetes and glucose intolerance; it has thus proven useful as a marker for the early detection of these conditions. Lucica MI is a diagnostic kit for the measurement of urinary myoinositol; it is used to detect glucose intolerance and diabetes mellitus at an early stage in disease progression. The test is based on an enzymatic method that uses liquid reagents requiring no preparation. Clinical trial results demonstrate that the test could be used to detect not only diabetes mellitus, but also to distinguish impaired fasting glucose and impaired glucose tolerance from normal glucose tolerance.

  10. Insulin resistance and lipid profile during an oral glucose tolerance test in women with and without gestational diabetes mellitus.

    PubMed

    Liang, Zx; Wu, Y; Zhu, Xy; Fang, Q; Chen, Dq

    2016-01-01

    We aimed to compare changes in insulin levels during an oral glucose tolerance test (OGTT) between women with normal glucose tolerance (NGT) during pregnancy and those with gestational diabetes mellitus (GDM). Overall, 105 pregnant women between 24 and 28 weeks' gestation, 50 with NGT and 55 with GDM according to NDDG standard, were enrolled into the study. The levels of fasting blood glucose, insulin, triglyceride (TG) and total cholesterol (TC) and the insulin levels, blood glucose levels at 1, 2 and 3 hours post oral glucose administration during an OGTT (5.8, 10.6, 9.2 and 8.1 mmol/L, respectively) were measured. Then, insulin resistance (IR) index was calculated. There was no significant difference in fasting, 3-h insulin levels and 3-h blood glucose levels between those with NGT and those with GDM (P > 0.05). However, 1-h and 2-h insulin levels, fasting and 1-h and 2-h blood glucose levels in women with GDM were significantly higher than those in the NGT group (P < 0.05). Fasting TC and TG levels in the GDM group were significantly higher than those with NGT (P = 0.031 and P = 0.025, respectively). Correlation analysis showed that TG and TC levels were positively correlated with homoeostasis model assessment-IR (HOMA-IR) (r = 0.67 and r = 0.78, respectively; P < 0.05). Our findings suggest that insulin sensitivity in women with GDM was significantly lower than that observed in those with NGT. Reducing IR and blood lipids in women with GDM could potentially improve maternal and foetal outcomes.

  11. Finger temperature controller for non-invasive blood glucose measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Xiqin; Ting, Choon Meng; Yeo, Joon Hock

    2010-11-01

    Blood glucose level is an important parameter for doctors to diagnose and treat diabetes. The Near-Infra-Red (NIR) spectroscopy method is the most promising approach and this involves measurement on the body skin. However it is noted that the skin temperature does fluctuate with the environmental and physiological conditions and we found that temperature has important influences on the glucose measurement. In-vitro and in-vivo investigations on the temperature influence on blood glucose measurement have been carried out. The in-vitro results show that water temperature has significant influence on water absorption. Since 90% of blood components are water, skin temperature of measurement site has significant influence on blood glucose measurement. Also the skin temperature is related to the blood volume, blood volume inside capillary vessels changes with skin temperature. In this paper the relationship of skin temperature and signal from the skin and inside tissue was studied at different finger temperatures. Our OGTT (oral glucose tolerance test) trials results show the laser signals follow the skin temperature trend and the correlation of signal and skin temperature is much stronger than the correlation of signal and glucose concentration. A finger heater device is designed to heat and maintain the skin temperature of measurement site. The heater is controlled by an electronic circuit according to the skin temperature sensed by a thermocouple that is put close to the measurement site. In vivo trials were carried out and the results show that the skin temperature significantly influences the signal fluctuations caused by pulsate blood and the average signal value.

  12. Objectively-measured sleep duration and hyperglycemia in pregnancy

    PubMed Central

    Herring, Sharon J.; Nelson, Deborah B.; Pien, Grace W.; Homko, Carol; Goetzl, Laura M.; Davey, Adam; Foster, Gary D.

    2013-01-01

    Objective Our primary purpose was to assess the impact of objectively-measured nighttime sleep duration on gestational glucose tolerance. We additionally examined associations of objectively-measured daytime sleep duration and nap frequency on maternal glycemic control. Methods 63 urban, low-income, pregnant women wore wrist actigraphs for an average of 6 full days in mid-pregnancy prior to screening for hyperglycemia using the 1-hour oral glucose tolerance test (OGTT). Correlations of nighttime and daytime sleep durations with 1-hour OGTT values were analyzed. Multivariable logistic regression was used to evaluate independent associations between sleep parameters and hyperglycemia, defined as 1-hour OGTT values ≥ 130 mg/dL. Results Mean nighttime sleep duration was 6.9 ± 0.9 hours which was inversely correlated with 1-hour OGTT values (r = −0.28, p = 0.03). Shorter nighttime sleep was associated with hyperglycemia, even after controlling for age and body mass index (adjusted OR: 0.2; 95% CI: 0.1, 0.8). There were no associations of daytime sleep duration and nap frequency with 1-hour OGTT values or hyperglycemia. Conclusions Using objective measures of maternal sleep time, we found that women with shorter nighttime sleep durations had an increased risk of gestational hyperglycemia. Larger prospective studies are needed to confirm our negative daytime sleep findings. PMID:24239498

  13. Neuroscience of glucose homeostasis.

    PubMed

    La Fleur, S E; Fliers, E; Kalsbeek, A

    2014-01-01

    Plasma glucose concentrations are homeostatically regulated and maintained within strict boundaries. Several mechanisms are in place to increase glucose output when glucose levels in the circulation drop as a result of glucose utilization, or to decrease glucose output and increase tissue glucose uptake to prevent hyperglycemia. Although the term homeostasis mostly refers to stable levels, the blood glucose concentrations fluctuate over the day/night cycle, with the highest concentrations occurring just prior to the activity period in anticipation of increased caloric need. In this chapter we describe how the brain, particularly the hypothalamus, is involved in both the daily rhythm of plasma glucose concentrations and acute glucose challenges.

  14. Distinct response of fat and gastrointestinal tissue to glucose in gestational diabetes mellitus and polycystic ovary syndrome.

    PubMed

    Vejrazkova, D; Lischkova, O; Vankova, M; Stanicka, S; Vrbikova, J; Lukasova, P; Vcelak, J; Vacinova, G; Bendlova, B

    2016-12-16

    Gestational diabetes mellitus (GDM) and polycystic ovary syndrome (PCOS) are distinct pathologies with impaired insulin sensitivity as a common feature. The aim of this study was to evaluate the response of fat tissue adipokines and gastrointestinal incretins to glucose load in patients diagnosed with one of the two disorders and to compare it with healthy controls. Oral glucose tolerance test (oGTT) was performed in 77 lean young women: 22 had positive history of GDM, 19 were PCOS patients, and 36 were healthy controls. Hormones were evaluated in fasting and in 60 min intervals during the 3 hour oGTT using Bio-Plex ProHuman Diabetes 10-Plex Assay for C-peptide, ghrelin, GIP, GLP1, glucagon, insulin, leptin, total PAI1, resistin, visfatin and Bio-Plex ProHuman Diabetes Adipsin and Adiponectin Assays (Bio-Rad). Despite lean body composition, both PCOS and GDM women were more insulin resistant than controls. Significant postchallenge differences between the GDM and PCOS groups were observed in secretion of adipsin, leptin, glucagon, visfatin, ghrelin, GIP, and also GLP1 with higher levels in GDM. Conversely, PCOS was associated with the highest resistin, C-peptide, and PAI1 levels. Our data suggest that decreased insulin sensitivity observed in lean women with GDM and PCOS is associated with distinct hormonal response of fat and gastrointestinal tissue to glucose load.

  15. A phase 2 safety study of accelerated elotuzumab infusion, over less than 1 hour, in combination with lenalidomide and dexamethasone, in patients with multiple myeloma.

    PubMed

    Berenson, James; Manges, Robert; Badarinath, Suprith; Cartmell, Alan; McIntyre, Kristi; Lyons, Roger; Harb, Wael; Mohamed, Hesham; Nourbakhsh, Ali; Rifkin, Robert

    2017-02-18

    Elotuzumab, an immunostimulatory SLAMF7-targeting monoclonal antibody, induces myeloma cell death with minimal effects on normal tissue. In a previous phase 3 study in patients with relapsed/refractory multiple myeloma (RRMM), elotuzumab (10 mg/kg, ∼3-hour infusion), combined with lenalidomide and dexamethasone, demonstrated durable efficacy and acceptable safety; 10% (33/321) of patients had infusion reactions (IRs; Grade 1/2: 29; Grade 3: 4). This phase 2 study (NCT02159365) investigated an accelerated infusion schedule in 70 patients with newly diagnosed multiple myeloma or RRMM. The primary endpoint was cumulative incidence of Grade 3/4 IRs by completion of treatment Cycle 2. Dosing comprised elotuzumab 10 mg/kg intravenously (weekly, Cycles 1-2; biweekly, Cycles 3+), lenalidomide 25 mg (daily, Days 1-21) and dexamethasone (28 mg orally and 8 mg intravenously, weekly, Cycles 1-2; 40 mg orally, weekly, Cycles 3+), in 28-day cycles. Premedication with diphenhydramine, acetaminophen, and ranitidine (or their equivalents) was given as in previous studies. If no IRs occurred, infusion rate was increased in Cycle 1 from 0.5 to 2 mL/min during dose 1 (∼2 hours 50 min duration) to 5 mL/min for the entire infusion by dose 3 and also during all subsequent infusions (∼1-hour duration). Median number of treatment cycles was six. No Grade 3/4 IRs occurred; only one Grade 1 and one Grade 2 IR occurred, both during the first infusion. These data support the safety of a faster infusion of elotuzumab administered over ∼1 hour by the third dose, providing a more convenient alternative dosing option for patients. This article is protected by copyright. All rights reserved.

  16. Opioid blockade effect on insulin beta-cells secretory patterns in polycystic ovary syndrome. Oral glucose load versus intravenous glucagon bolus.

    PubMed

    Ciampelli, M; Fulghesu, A M; Guido, M; Murgia, F; Muzj, G; Belosi, C; Fortini, A; Cento, R; Lanzone, A

    1998-01-01

    In order to evaluate the involvement of endogenous opiates in the insulin disorders of polycystic ovary syndrome (PCOs) a total of 25 PCOs women and 11 normo-ovulatory controls were studied by comparing the effect of a chronic opioid blockade on beta-cells responsiveness to oral glucose load and to intravenous glucagon bolus. Each patient, studied on follicular phase, underwent to oral glucose tolerance test (OGTT), and, 2 days later, to a glucagon intravenous bolus (1 mg); these tests were then repeated after 6 weeks of naltrexone treatment (50 mg orally). Naltrexone treatment did not modify the insulin secretory patterns of control subjects, whereas the same therapy significantly reduced, in hyperinsulinemic PCOs women, the beta-cell hyperresponsiveness both to oral glucose load and to intravenous glucagon (p < 0.05 and p < 0.01, respectively), even if with different mean percent decrease (32% OGTT vs. 45% glucagon, p < 0.05). Moreover, normoinsulinemic PCOs patients showed a slight, but not significantly increase in the beta-cells response to OGTT after opioid blockade, whereas, in the same situation, the insulin release after glucagon bolus was significantly reduced (p < 0.01). Chronic opioid blockade did not modify gonadotropins, steroids and SHBG levels in either group. Our data show that naltrexone treatment is able to reduce the beta-cell response to a direct intravenous secretagogue stimulus in all PCOs patients, while only in hyperinsulinemic PCOs subjects the same treatment is effective in reducing the exaggerated insulin secretion after oral glucose load. The reason for such a discrepancy could be ascribed to a different effect of opioids on first- and second-phase insulin secretion, or, alternatively, to an involvement of other secretagogue factors, such as glucoincretins.

  17. Role of the ENPP1 K121Q Polymorphism in Glucose Homeostasis

    PubMed Central

    Baratta, Roberto; Rossetti, Paola; Prudente, Sabrina; Barbetti, Fabrizio; Sudano, Dora; Nigro, Angela; Farina, Maria Grazia; Pellegrini, Fabio; Trischitta, Vincenzo; Frittitta, Lucia

    2008-01-01

    OBJECTIVE— To study the role of the ENPP1 Q121 variant on glucose homeostasis in whites from Italy. RESEARCH DESIGN AND METHODS— We conducted case-control studies in 764 adults (from two independent samples of 289 nonobese and 485 obese individuals) and 240 overweight/obese children undergoing oral glucose tolerance testing (OGTT). Early-phase insulin secretion and insulin sensitivity (the insulinogenic index and the insulin sensitivity index) and their interplay (the disposition index) were calculated. RESULTS— In adult subjects, glucose profiles during OGTT were significantly (P = 2 × 10−2) different across K121Q genotype groups and higher in QQ than KK individuals (P = 5 × 10−2). The insulinogenic index was significantly reduced in QQ (18.5 ± 3.4) compared with both KK (31.6 ± 1.0; P = 2.2 × 10−7) and KQ (30.5 ± 1.5; P = 3.2 × 10−6) individuals. KQ individuals also showed a reduced insulin sensitivity index compared with KK subjects (P = 3.6 × 10−2). The disposition index was lower in QQ carriers than in KQ and KK individuals (P = 8 × 10−3 and 4 × 10−4, respectively) and lower in KQ than in KK individuals (P = 3 × 10−2). Data obtained in overweight/obese children were very similar to those observed in adults, with QQ individuals showing (compared with KQ and KK subjects) a reduced insulinogenic index (P = 7 × 10−3 and 2 × 10−2, respectively) and disposition index (P = 2 × 10−2 and 7 × 10−3, respectively). CONCLUSIONS— Homozygous carriers of the ENPP1 Q121 variant are characterized by an altered glucose homeostasis. Reduced early-phase insulin secretion and inefficient interplay between insulin secretion and sensitivity, which occur at early ages, are major determinants of this defect. PMID:18776139

  18. Autonomic Markers of Impaired Glucose Metabolism: Effects of Sleep-Disordered Breathing

    PubMed Central

    Wang, Wenli; Redline, Susan; Khoo, Michael C. K.

    2012-01-01

    Background The association between diabetes and abnormalities in autonomic function is well-known, but it is not clear if this association can be extended to subjects with prediabetic impaired glucose metabolism (IGM). Sleep-disordered breathing (SDB), which commonly occurs in this population, is often overlooked. We sought to determine how autonomic function, monitored in an overnight sleep study setting, may be impaired in subjects with IGM and/or SDB. Methods Polysomnograms (PSGs) selected from the Cleveland Family Study database were categorized into four groups: normal, SDB (respiratory disturbance index > 5/h), IGM, and both SDB and IGM. Impaired glucose metabolism was defined as an oral glucose tolerance test (OGTT) level > 140 mg/dl. Time-domain and frequency-domain indices of heart rate variability were used to quantify autonomic impairment. Baroreflex sensitivity determined using pulse transit time (BRSPTT), an indirect measure of baroreflex sensitivity based on spontaneous pulse transit time fluctuations, was used as a surrogate measure of baroreflex sensitivity. Results Based on 31 PSGs from subjects (16 males, 15 females) ages 20.8–61.2 years, both SDNN and BRSPTT were found to be 20-25% lower in SDB and ~40% lower in IGM and SDB + IGM as compared to subjects without either condition. In analyses of continuous measures, mean standard deviation of 5 min R–R intervals (SDNN) and BRSPTT were found to be negatively correlated with OGTT following adjustment for age and body mass index. Oral glucose tolerance test and age were the two most significant factors for predicting SDNN and BRSPTT. Conclusions Our analyses suggest that cardiac autonomic control is impaired in IGM, regardless of whether SDB is present. The abnormal autonomic function involves degradation of baroreflex regulation. PMID:23063043

  19. Beneficial effect of dietary Ephedra sinica on obesity and glucose intolerance in high-fat diet-fed mice

    PubMed Central

    SONG, MOON-KOO; UM, JAE-YOUNG; JANG, HYEUNG-JIN; LEE, BYUNG-CHEOL

    2012-01-01

    Obesity is a major contributor to both glucose intolerance and metabolic syndrome. In this study, we investigated the anti-obesity and anti-hyperglycemic effects of Ephedra sinica on high-fat diet-fed mice. Male ICR mice were divided into four groups; the normal group, the obese and diabetic control group treated with a high-fat diet, the positive control group treated with a high-fat diet containing acarbose, and the experimental group treated with a high-fat diet containing Ephedra sinica. The effects of Ephedra sinica on obesity and glucose intolerance were measured by an oral glucose tolerance test (OGTT), plasma biochemistry, body and epididymal fat weight; the expression of adiponectin, peroxisome-proliferator-activated receptor α (PPAR-α), tumor necrosis factor α (TNF-α) and leptin was also determined. Ephedra sinica reduced weight gain and epididymal fat accumulation, improved glucose intolerance on the OGTT, decreased triglycerides and increased high-density lipoprotein cholesterol compared to the controls. Moreover, it reduced weight gain and fasting glucose levels and improved HDL-cholesterol levels more than acarbose. Gene expression analysis revealed that Ephedra sinica upregulated the expression of adiponectin and PPAR-α, and downregulated the expression of TNF-α. From these results, we suggest that Ephedra sinica may reduce obesity and hyperglycemia by increasing PPAR-α and adiponectin and reducing TNF-α, and that it may have the potential to be used clinically as an ingredient in food or drugs effective in obesity-related glucose intolerance treatments. PMID:22969956

  20. Effects of oral L-carnitine supplementation on insulin sensitivity indices in response to glucose feeding in lean and overweight/obese males.

    PubMed

    Galloway, Stuart D R; Craig, Thomas P; Cleland, Stephen J

    2011-07-01

    Infusion of carnitine has been observed to increase non-oxidative glucose disposal in several studies, but the effect of oral carnitine on glucose disposal in non-diabetic lean versus overweight/obese humans has not been examined. This study examined the effects of 14 days of L-carnitine L-tartrate oral supplementation (LC) on blood glucose, insulin, NEFA and GLP-1 responses to an oral glucose tolerance test (OGTT). Sixteen male participants were recruited [lean (n = 8) and overweight/obese (n = 8)]. After completing a submaximal predictive exercise test, participants were asked to attend three experimental sessions. These three visits were conducted in the morning to obtain fasting blood samples and to conduct 2 h OGTTs. The first visit was a familiarisation trial and the final two visits were conducted 2 weeks apart following 14 days of ingestion of placebo (PL, 3 g glucose/day) and then LC (3 g LC/day) ingested as two capsules 3×/day with meals. On each visit, blood was drawn at rest, at intervals during the OGTT for analysis of glucose, insulin, non-esterified fatty acids (NEFA) and total glucagon-like peptide-1 (GLP-1). Data obtained were used for determination of usual insulin sensitivity indices (HOMA-IR, AUC glucose, AUC insulin, 1st phase and 2nd phase β-cell function, estimated insulin sensitivity index and estimated metabolic clearance rate). Data were analysed using RMANOVA and post hoc comparisons where appropriate. There was a significant difference between groups for body mass, % fat and BMI with no significant difference in age and height. Mean (SEM) plasma glucose concentration at 30 min was significantly lower (p < 0.05) in the lean group on the LC trial compared with PL [8.71(0.70) PL; 7.32(0.36) LC; mmol/L]. Conversely, plasma glucose concentration was not different at 30 min, but was significantly higher at 90 min (p < 0.05) in the overweight/obese group on the LC trial [5.09(0.41) PL; 7.11(0.59) LC; mmol/L]. Estimated first phase and second

  1. Bile Acid Determination after Standardized Glucose Load in Pregnant Women

    PubMed Central

    Adams, April; Jacobs, Katherine; Vogel, Rachel Isaksson; Lupo, Virginia

    2015-01-01

    Objective Intrahepatic cholestasis of pregnancy (ICP) is a rare liver disorder, usually manifesting in the third trimester and associated with increased perinatal morbidity and mortality. The hallmark laboratory abnormality in ICP is elevated fasting serum bile acids; however, there are limited data on whether a nonfasting state affects a pregnant woman's total bile acids. This study assesses fasting and nonfasting bile acid levels in 10 healthy pregnant women after a standardized glucose load to provide insight into the effects of a glucose load on bile acid profiles. Study Design Pilot prospective cohort analysis of serum bile acids in pregnant women. A total of 10 healthy pregnant women from 28 to 32 weeks' gestation were recruited for the study before undergoing a glucose tolerance test. Total serum bile acids were collected for each subject in the overnight fasting state, and 1 and 3 hours after the 100-g glucose load. Results There was a statistically significant difference between fasting versus 3-hour values. There was no statistically significant difference between fasting versus 1-hour and 1-hour versus 3-hour values. Conclusion There is a difference between fasting and nonfasting total serum bile acids after a 100-g glucose load in healthy pregnant women. PMID:26495178

  2. Use of anesthesia dramatically alters the oral glucose tolerance and insulin secretion in C57Bl/6 mice.

    PubMed

    Windeløv, Johanne A; Pedersen, Jens; Holst, Jens J

    2016-06-01

    Evaluation of the impact of anesthesia on oral glucose tolerance in mice. Anesthesia is often used when performing OGTT in mice to avoid the stress of gavage and blood sampling, although anesthesia may influence gastrointestinal motility, blood glucose, and plasma insulin dynamics. C57Bl/6 mice were anesthetized using the following commonly used regimens: (1) hypnorm/midazolam repetitive or single injection; (2) ketamine/xylazine; (3) isoflurane; (4) pentobarbital; and (5) A saline injected, nonanesthetized group. Oral glucose was administered at time 0 min and blood glucose measured in the time frame -15 to +150 min. Plasma insulin concentration was measured at time 0 and 20 min. All four anesthetic regimens resulted in impaired glucose tolerance compared to saline/no anesthesia. (1) hypnorm/midazolam increased insulin concentrations and caused an altered glucose tolerance; (2) ketamine/xylazine lowered insulin responses and resulted in severe hyperglycemia throughout the experiment; (3) isoflurane did not only alter the insulin secretion but also resulted in severe hyperglycemia; (4) pentobarbital resulted in both increased insulin secretion and impaired glucose tolerance. All four anesthetic regimens altered the oral glucose tolerance, and we conclude that anesthesia should not be used when performing metabolic studies in mice.

  3. Genetic Association Analysis of Fasting and 1- and 2-Hour Glucose Tolerance Test Data Using a Generalized Index of Dissimilarity Measure for the Korean Population

    PubMed Central

    Yee, Jaeyong; Kim, Yongkang; Park, Taesung

    2016-01-01

    Glucose tolerance tests have been devised to determine the speed of blood glucose clearance. Diabetes is often tested with the standard oral glucose tolerance test (OGTT), along with fasting glucose level. However, no single test may be sufficient for the diagnosis, and the World Health Organization (WHO)/International Diabetes Federation (IDF) has suggested composite criteria. Accordingly, a single multi-class trait was constructed with three of the fasting phenotypes and 1- and 2-hour OGTT phenotypes from the Korean Association Resource (KARE) project, and the genetic association was investigated. All of the 18 possible combinations made out of the 3 sets of classification for the individual phenotypes were taken into our analysis. These were possible due to a method that was recently developed by us for estimating genomic associations using a generalized index of dissimilarity. Eight single-nucleotide polymorphisms (SNPs) that were found to have the strongest main effect are reported with the corresponding genes. Four of them conform to previous reports, located in the CDKAL1 gene, while the other 4 SNPs are new findings. Two-order interacting SNP pairs of are also presented. One pair (rs2328549 and rs6486740) has a prominent association, where the two single-nucleotide polymorphism locations are CDKAL1 and GLT1D1. The latter has not been found to have a strong main effect. New findings may result from the proper construction and analysis of a composite trait. PMID:28154509

  4. Noninvasive blood glucose measurement using multiple laser diodes

    NASA Astrophysics Data System (ADS)

    Ooi, E. T.; Zhang, X. Q.; Chen, J. H.; Soh, P. H.; Ng, K.; Yeo, J. H.

    2007-02-01

    In the event of diabetes clinicians have advocated that frequent monitoring of a diabetic's blood glucose level is the key to avoid future complications (kidney failure, blindness, amputations, premature death, etc.,) associated with the disease. While the test-strip glucose meters available in current consumer markets allow for frequent monitoring, a more convenient technique that is accurate, painless and sample-free is preferable in a diabetic's daily routine. This paper presents a non-invasive blood glucose measurement technique using diffuse reflectance near infrared (NIR) signals. This technique uses a set of laser diodes, each operating at fixed wavelengths in the first overtone region. The NIR signals from the laser diodes are channeled to the measurement site viz., the nail-bed by means of optical fibers. A series of in vivo experiments have been performed on eight normal human subjects using a standard Oral Glucose Tolerance Test (OGTT) protocol. The reflected NIR signals are inputs to a Partial Least Squares (PLS) algorithm for calibration and future predictions. The calibration models used are developed using in vivo datasets and are unique to a particular individual. The 1218 paired points collected from the eight test subjects plotted on the Clarke Error Grid, revealed that 87.3% of these points fall within the A zone while the remainder, within the B zone, both of which, are clinically accepted. The standard error of prediction was +/-13.14mg/dL for the best calibration model. A Bland-Altman analysis of the 1218 paired points yields a 76.3% confidence level for a measurement accuracy of +/-20mg/dL. These results demonstrate the initial potential of the technique for non-invasive blood glucose measurements in vivo.

  5. Effects of dextromethorphan as add-on to sitagliptin on blood glucose and serum insulin concentrations in individuals with type 2 diabetes mellitus: a randomized, placebo-controlled, double-blinded, multiple crossover, single-dose clinical trial.

    PubMed

    Marquard, J; Stirban, A; Schliess, F; Sievers, F; Welters, A; Otter, S; Fischer, A; Wnendt, S; Meissner, T; Heise, T; Lammert, E

    2016-01-01

    In this clinical trial, we investigated the blood glucose (BG)-lowering effects of 30, 60 and 90 mg dextromethorphan (DXM) as well as 100 mg sitagliptin alone versus combinations of DXM and sitagliptin during an oral glucose tolerance test (OGTT) in 20 men with T2DM. The combination of 60 mg DXM plus 100 mg sitagliptin was observed to have the strongest effect in the OGTT. It lowered maximum BG concentrations and increased the baseline-adjusted area under the curve for serum insulin concentrations in the first 30 min of the OGTT (mean ± standard deviation 240 ± 47 mg/dl and 8.1 ± 6.1 mU/l/h, respectively) to a significantly larger extent than did 100 mg sitagliptin alone (254 ± 50 mg/dl and 5.8 ± 2.5 mU/l/h, respectively; p < 0.05) and placebo (272 ± 49 mg/dl and 3.9 ± 3.0 mU/l/h, respectively; p < 0.001). All study drugs were well tolerated, alone and in combination, without serious adverse events or hypoglycaemia. Long-term clinical trials are now warranted to investigate the potential of the combination of 30 or 60 mg DXM and dipeptidyl peptidase-4 inhibitors in the treatment of individuals with T2DM, in particular as preclinical studies have identified the β-cell protective properties of DXM.

  6. Cooking enhances beneficial effects of pea seed coat consumption on glucose tolerance, incretin, and pancreatic hormones in high-fat-diet-fed rats.

    PubMed

    Hashemi, Zohre; Yang, Kaiyuan; Yang, Han; Jin, Alena; Ozga, Jocelyn; Chan, Catherine B

    2015-04-01

    Pulses, including dried peas, are nutrient- and fibre-rich foods that improve glucose control in diabetic subjects compared with other fibre sources. We hypothesized feeding cooked pea seed coats to insulin-resistant rats would improve glucose tolerance by modifying gut responses to glucose and reducing stress on pancreatic islets. Glucose intolerance induced in male Sprague-Dawley rats with high-fat diet (HFD; 10% cellulose as fibre) was followed by 3 weeks of HFD with fibre (10%) provided by cellulose, raw-pea seed coat (RP), or cooked-pea seed coat (CP). A fourth group consumed low-fat diet with 10% cellulose. Oral and intraperitoneal glucose tolerance tests (oGTT, ipGTT) were done. CP rats had 30% and 50% lower glucose and insulin responses in oGTT, respectively, compared with the HFD group (P < 0.05) but ipGTT was not different. Plasma islet and incretin hormone concentrations were measured. α- and β-cell areas in the pancreas and density of K- and L-cells in jejunum and ileum were quantified. Jejunal expression of hexose transporters was measured. CP feeding increased fasting glucagon-like peptide 1 and glucose-stimulated gastric inhibitory polypeptide responses (P < 0.05), but K- and L-cells densities were comparable to HFD, as was abundance of SGLT1 and GLUT2 mRNA. No significant difference in β-cell area between diet groups was observed. α-cell area was significantly smaller in CP compared with RP rats (P < 0.05). Overall, our results demonstrate that CP feeding can reverse adverse effects of HFD on glucose homeostasis and is associated with enhanced incretin secretion and reduced α-cell abundance.

  7. Impact of Reduced Meal Frequency Without Caloric Restriction on Glucose Regulation in Healthy, Normal Weight Middle-Aged Men and Women

    PubMed Central

    Carlson, Olga; Martin, Bronwen; Stote, Kim S.; Golden, Erin; Maudsley, Stuart; Najjar, Samer S.; Ferrucci, Luigi; Ingram, Donald K.; Longo, Dan L.; Rumpler, William V.; Baer, David J.; Egan, Josephine; Mattson, Mark P.

    2007-01-01

    An unresolved issue in the field of diet and health is if and how changes in meal frequency affect energy metabolism in humans. We therefore evaluated the influence of reduced meal frequency without a reduction in energy intake on glucose metabolism in normal weight healthy male and female subjects. The study was a randomized cross-over design, with 2 eight-week treatment periods (with an intervening 11 week off-diet period) in which subjects consumed all of their calories for weight maintenance distributed in either 3 meals or 1 meal per day (consumed between 17:00 and 21:00). Energy metabolism was evaluated at designated time points throughout the study by performing morning oral glucose tolerance tests (OGTT) and measuring levels of glucose, insulin, glucagon, leptin, ghrelin, adiponectin, resistin and brain-derived neurotrophic factor (BDNF). Subjects consuming 1 meal/d exhibited higher morning fasting plasma glucose levels, greater and more sustained elevations of plasma glucose concentrations and a delayed insulin response in the OGTT compared to subjects consuming 3 meal/d. Levels of ghrelin were elevated in response to the 1 meal/d regimen. Fasting levels of insulin, leptin, ghrelin, adiponectin, resistin and BDNF were not significantly affected by meal frequency. Subjects consuming a single large daily meal exhibit elevated fasting glucose levels, and impaired morning glucose tolerance associated with a delayed insulin response, during a 2 month diet period compared to those consuming 3 meals/day. The impaired glucose tolerance was reversible and was not associated with alterations in the levels of adipokines or BDNF. PMID:17998028

  8. A cross-over study of the acute effects of espresso coffee on glucose tolerance and insulin sensitivity in people with type 2 diabetes mellitus.

    PubMed

    Krebs, Jeremy D; Parry-Strong, Amber; Weatherall, Mark; Carroll, Richard W; Downie, Michelle

    2012-09-01

    The objective was to determine the effect of a single dose of espresso caffeinated coffee, decaffeinated coffee, or water on glucose tolerance and insulin sensitivity in people with type 2 diabetes mellitus. Eighteen participants who were habitual coffee drinkers, were studied using a random-order cross-over design. After a fasting blood sample participants consumed either a double-shot black espresso coffee, decaffeinated coffee, or hot water. The main outcomes were area under the curve (AUC) glucose and insulin, and insulin sensitivity (Matsuda index) during a 75 g oral glucose tolerance test (OGTT) performed one hour later. Other outcomes were change in glucose and insulin and also the insulinogenic index (IGI) and disposition index (DI). AUC glucose was marginally different between beverages (P=.06) being greater following caffeinated coffee than water, mean difference 104 mmol/L/180 min (95% CI 0.1 to 198.1, P=.031), or decaffeinated coffee, mean difference 92.1 mmol/L/180 min (95% CI -1.9 to 186.1, P=.055). There was no difference in AUC insulin (P=.87) or insulin sensitivity (P=.47), nor in change in glucose or insulin over the hour following beverage consumption. There was a marginal difference in IGI between beverages (P=.097) with coffee having a lower incremental increase in insulin/glucose than water (P=.037) though no difference between coffee and decaffeinated coffee (P=.54) and no difference in DI (P=.23). Black espresso coffee in people with type 2 diabetes mellitus results in a marginally greater excursion of glucose during a following OGTT compared with water or decaffeinated coffee. This effect does not appear to be mediated by changes in insulin sensitivity.

  9. CSF glucose test

    MedlinePlus

    Glucose test - CSF; Cerebrospinal fluid glucose test ... The glucose level in the CSF should be 50 to 80 mg/100 mL (or greater than 2/3 ... Abnormal results include higher and lower glucose levels. Abnormal ... or fungus) Inflammation of the central nervous system Tumor

  10. Blood Test: Glucose

    MedlinePlus

    ... Your 1- to 2-Year-Old Blood Test: Glucose KidsHealth > For Parents > Blood Test: Glucose A A A What's in this article? What ... de sangre: glucosa What It Is A blood glucose test measures the amount of glucose (the main ...

  11. Screening of gestational diabetes mellitus in early pregnancy by oral glucose tolerance test and glycosylated fibronectin: study protocol for an international, prospective, multicentre cohort trial

    PubMed Central

    Huhn, E A; Fischer, T; Göbl, C S; Todesco Bernasconi, M; Kreft, M; Kunze, M; Schoetzau, A; Dölzlmüller, E; Eppel, W; Husslein, P; Ochsenbein-Koelble, N; Zimmermann, R; Bäz, E; Prömpeler, H; Bruder, E; Hahn, S; Hoesli, I

    2016-01-01

    Introduction As the accurate diagnosis and treatment of gestational diabetes mellitus (GDM) is of increasing importance; new diagnostic approaches for the assessment of GDM in early pregnancy were recently suggested. We evaluate the diagnostic power of an ‘early’ oral glucose tolerance test (OGTT) 75 g and glycosylated fibronectin (glyFn) for GDM screening in a normal cohort. Methods and analysis In a prospective cohort study, 748 singleton pregnancies are recruited in 6 centres in Switzerland, Austria and Germany. Women are screened for pre-existing diabetes mellitus and GDM by an ‘early’ OGTT 75 g and/or the new biomarker, glyFn, at 12–15 weeks of gestation. Different screening strategies are compared to evaluate the impact on detection of GDM by an OGTT 75 g at 24–28 weeks of gestation as recommended by the International Association of Diabetes and Pregnancy Study Groups (IADPSG). A new screening algorithm is created by using multivariable risk estimation based on ‘early’ OGTT 75 g and/or glyFn results, incorporating maternal risk factors. Recruitment began in May 2014. Ethics and dissemination This study received ethical approval from the ethics committees in Basel, Zurich, Vienna, Salzburg and Freiburg. It was registered under http://www.ClinicalTrials.gov (NCT02035059) on 12 January 2014. Data will be presented at international conferences and published in peer-reviewed journals. Trial registration number NCT02035059. PMID:27733413

  12. Abnormal antioxidant status in impaired glucose tolerance and non-insulin-dependent diabetes mellitus.

    PubMed

    Vijayalingam, S; Parthiban, A; Shanmugasundaram, K R; Mohan, V

    1996-08-01

    A total of 105 subjects with impaired glucose tolerance were classified into two groups, 51 subjects with plasma glucose > 11.1 mmol l-1 in one of the blood samplings during OGTT, but at 2 h being less than < 11.1 mmol l-1 were classified as early hyperglycaemics. Fifty-four cases were classified as true IGT, with fasting plasma glucose < 7.8 mmol l-1 and post plasma glucose level between 7.8 and 11.1 mmol l-1. Age and sex matched groups of normals (healthy adults) and NIDDM cases without symptomatic secondary complications were also included in the study. Lipid peroxidation (LPO) product in plasma, erythrocyte, and erythrocyte cell membrane were found to be significantly elevated (p < 0.001) in IGT, early hyperglycaemia and diabetes mellitus while glycosylated haemoglobin was also higher. Antioxidant enzymes superoxide dismutase and catalase were significantly lower in red blood cells obtained from IGT and early hyperglycaemic groups. They were closer to the levels showed in NIDDM confirming that antioxidant deficiency is already present in subjects classified as impaired glucose tolerant. Among the antioxidant scavengers, reduced glutathione (GSH) and ascorbic acid are reduced by 15% and 20% in IGT and NIDDM, respectively. We conclude that antioxidant status is poor in both IGT and NIDDM, suggesting an overlap of frank diabetic state in those classified as IGT. It is possible that antioxidant therapy might retard progression from IGT to NIDDM.

  13. Glucose tolerance and lipid-lipoprotein levels in middle-aged powerlifters.

    PubMed

    Hurley, B F; Hagberg, J M; Seals, D R; Ehsani, A A; Goldberg, A P; Holloszy, J O

    1987-02-01

    The purpose of this study was to obtain information regarding the effects of a form of strength training (powerlifting) on certain coronary artery disease (CAD) risk factors in middle-aged men. The risk factors studied were the plasma lipid-lipoprotein profile, glucose tolerance and plasma insulin levels, all of which have been shown to be favourably influenced by endurance training in middle-aged and older men. Five elite powerlifters (52 +/- 9 years) were compared to distance runners and sedentary controls of similar age with whom they were matched in terms of body fatness as estimated from skin-fold thickness measurements. The powerlifters had a significantly (P less than 0.01) lower HDL cholesterol (HDL-C) level (34 +/- 4 mg/100 ml) than the sedentary controls (48 +/- 12 mg/100 ml) and runners (54 +/- 8 mg/100 ml). The total cholesterol to HDL-C ratio, a good indicator of CAD risk, was 41% higher in the powerlifters than in the controls, and 57% higher than in the runners (both P less than 0.01). The total area under the glucose tolerance curve during an oral glucose tolerance test (OGTT) for the powerlifters was 74% higher than for the sedentary controls (P less than 0.05) and 229% higher than for runners (P less than 0.01). Similarly, the total area under the OGTT insulin curve for the powerlifters was 68% higher than for sedentary controls and 332% higher than for the runners (P less than 0.001). These findings suggest that middle-aged powerlifters, in marked contrast to endurance athletes, have an increased risk of developing CAD.

  14. Glucose test (image)

    MedlinePlus

    ... person with diabetes constantly manages their blood's sugar (glucose) levels. After a blood sample is taken and tested, it is determined whether the glucose levels are low or high. Following your health ...

  15. Blood Glucose Monitoring Devices

    MedlinePlus

    ... the Bar for Blood Glucose Meter Performance Recalls & Alerts Shasta Technologies GenStrip Blood Glucose Test Strips May ... Latest Recalls Report an Adverse Event MedWatch Safety Alerts News Releases Consumer Updates About FDA Contact FDA ...

  16. All about Blood Glucose

    MedlinePlus

    Toolkit No. 15 All About Blood Glucose Keeping your blood glucose (sugar)in your target range can prevent or delay the health problems ... Diabetes Association, Inc. 1/15 Toolkit No.15: All About Blood Glucose continued team about when and ...

  17. Effect of guava (Psidium guajava Linn.) leaf soluble solids on glucose metabolism in type 2 diabetic rats.

    PubMed

    Shen, Szu-Chuan; Cheng, Fang-Chi; Wu, Ning-Jung

    2008-11-01

    This study investigated the effect of aqueous and ethanol soluble solid extracts of guava (Psidium guajava Linn.) leaves on hypoglycemia and glucose metabolism in type 2 diabetic rats. Low-dose streptozotocin (STZ) and nicotinamide were injected into Sprague-Dawley (SD) rats to induce type 2 diabetes. Acute and long-term feeding tests were carried out, and an oral glucose tolerance test (OGTT) to follow the changes in plasma glucose and insulin levels was performed to evaluate the antihyperglycemic effect of guava leaf extracts in diabetic rats.The results of acute and long-term feeding tests showed a significant reduction in the blood sugar level in diabetic rats fed with either the aqueous or ethanol extract of guava leaves (p < 0.05). Long-term administration of guava leaf extracts increased the plasma insulin level and glucose utilization in diabetic rats. The results also indicated that the activities of hepatic hexokinase, phosphofructokinase and glucose-6-phosphate dehydrogenase in diabetic rats fed with aqueous extracts were higher than in the normal diabetic group (p < 0.05). On the other hand, diabetic rats treated with the ethanol extract raised the activities of hepatic hexokinase and glucose-6-phosphate dehydrogenase (p < 0.05) only. The experiments provided evidence to support the antihyperglycemic effect of guava leaf extract and the health function of guava leaves against type 2 diabetes.

  18. Effect of fructose or sucrose feeding with different levels on oral glucose tolerance test in normal and type 2 diabetic rats

    PubMed Central

    Kwon, Sanghee; Kim, You Jin

    2008-01-01

    This study was designed to determine whether acute fructose or sucrose administration at different levels (0.05 g/kg, 0.1 g/kg or 0.4 g/kg body weight) might affect oral glucose tolerance test (OGTT) in normal and type 2 diabetic rats. In OGTT, there were no significant differences in glucose responses between acute fructose- and sucrose-administered groups. However, in normal rats, the AUCs of the blood glucose response for the fructose-administered groups tended to be lower than those of the control and sucrose-administered groups. The AUCs of the lower levels fructoseor sucrose-administered groups tended to be smaller than those of higher levels fructose- or sucrose-administered groups. In type 2 diabetic rats, only the AUC of the lowest level of fructose-administered (0.05 g/kg body weight) group was slightly smaller than that of the control group. The AUCs of fructose-administered groups tended to be smaller than those of the sucrose-administered groups, and the AUCs of lower levels fructose-administered groups tended to be smaller than those fed higher levels of fructose. We concluded from this experiment that fructose has tendency to be more effective in blood glucose regulation than sucrose, and moreover, that smaller amount of fructose is preferred to larger amount. Specifically, our experiments indicated that the fructose level of 0.05 g/kg body weight as dietary supplement was the most effective amount for blood glucose regulation from the pool of 0.05 g/kg, 0.1 g/kg and 0.4 g/kg body weights. Therefore, our results suggest the use of fructose as the substitute sweetener for sucrose, which may be beneficial for blood glucose regulation. PMID:20016727

  19. Knockdown of neuropeptide Y in the dorsomedial hypothalamus reverses high-fat diet-induced obesity and impaired glucose tolerance in rats.

    PubMed

    Kim, Yonwook J; Bi, Sheng

    2016-01-15

    Neuropeptide Y (NPY) in the dorsomedial hypothalamus (DMH) plays an important role in the regulation of energy balance. While DMH NPY overexpression causes hyperphagia and obesity in rats, knockdown of NPY in the DMH via adeno-associated virus (AAV)-mediated RNAi (AAVshNPY) ameliorates these alterations. Whether this knockdown has a therapeutic effect on obesity and glycemic disorder has yet to be determined. The present study sought to test this potential using a rat model of high-fat diet (HFD)-induced obesity and insulin resistance, mimicking human obesity with impaired glucose homeostasis. Rats had ad libitum access to rodent regular chow (RC) or HFD. Six weeks later, an oral glucose tolerance test (OGTT) was performed for verifying HFD-induced glucose intolerance. After verification, obese rats received bilateral DMH injections of AAVshNPY or the control vector AAVshCTL, and OGTT and insulin tolerance test (ITT) were performed at 16 and 18 wk after viral injection (23 and 25 wk on HFD), respectively. Rats were killed at 26 wk on HFD. We found that AAVshCTL rats on HFD remained hyperphagic, obese, glucose intolerant, and insulin resistant relative to lean control RC-fed rats receiving DMH injection of AAVshCTL, whereas these alterations were reversed in NPY knockdown rats fed a HFD. NPY knockdown rats exhibited normal food intake, body weight, glucose tolerance, and insulin sensitivity, as seen in lean control rats. Together, these results demonstrate a therapeutic action of DMH NPY knockdown against obesity and impaired glucose homeostasis in rats, providing a potential target for the treatment of obesity and diabetes.

  20. Ambulatory glucose profile: Flash glucose monitoring.

    PubMed

    Kalra, Sanjay; Gupta, Yashdeep

    2015-12-01

    Ambulatory glucose profile (AGP) is a novel way of assessing glycaemic levels on a 24 hour basis, through a minimally invasive method, known as flash glucose monitoring. This review describes the unique features of AGP, differentiates it from existing methods of glucose monitoring, and explains how it helps pursue the glycaemic pentad. The review suggests pragmatic usage of this technology, including pre-test, intra-test, and post-test counselling, and lists specific clinical scenarios where the investigation seems to be of immense benefit.

  1. Effects of xylitol on carbohydrate digesting enzymes activity, intestinal glucose absorption and muscle glucose uptake: a multi-mode study.

    PubMed

    Chukwuma, Chika Ifeanyi; Islam, Md Shahidul

    2015-03-01

    The present study investigated the possible mechanism(s) behind the effects of xylitol on carbohydrate digesting enzymes activity, muscle glucose uptake and intestinal glucose absorption using in vitro, ex vivo and in vivo experimental models. The effects of increasing concentrations of xylitol (2.5%-40% or 164.31 mM-2628.99 mM) on alpha amylase and alpha glucosidase activity in vitro and intestinal glucose absorption and muscle glucose uptake were investigated under ex vivo conditions. Additionally, the effects of an oral bolus dose of xylitol (1 g per kg BW) on gastric emptying and intestinal glucose absorption and digesta transit in the different segments of the intestinal tract were investigated in normal and type 2 diabetic rats at 1 hour after dose administration, when phenol red was used as a recovery marker. Xylitol exhibited concentration-dependent inhibition of alpha amylase (IC₅₀ = 1364.04 mM) and alpha glucosidase (IC₅₀ = 1127.52 mM) activity in vitro and small intestinal glucose absorption under ex vivo condition. Xylitol also increased dose dependent muscle glucose uptake with and without insulin, although the uptake was not significantly affected by the addition of insulin. Oral single bolus dose of xylitol significantly delayed gastric emptying, inhibited intestinal glucose absorption but increased the intestinal digesta transit rate in both normal and diabetic rats compared to their respective controls. The data of this study suggest that xylitol reduces intestinal glucose absorption via inhibiting major carbohydrate digesting enzymes, slowing gastric emptying and fastening the intestinal transit rate, but increases muscle glucose uptake in normal and type 2 diabetic rats.

  2. The study of serum vitamin d and insulin resistance in chinese populations with normal glucose tolerance.

    PubMed

    Ding, Lin; Wang, Congcong; Ma, Heliang; Tian, Yuling; Lu, Yong; Pang, Shuguang

    2014-01-01

    Objectives. The aim of this study was to investigate the relationship between serum vitamin D and insulin resistance in Chinese subjects without diabetes mellitus. Methods. Serum 25(OH)D was measured in 897 individuals with normal glucose tolerance (NGT). Oral glucose tolerance tests (OGTTs) were conducted to exclude cases with diabetes, impaired fasting glucose (IFG), and impaired glucose tolerance (IGT). Metabolic parameters were measured and compared between the highest and lowest 25(OH)D quartiles. The relationship between serum 25(OH)D and homeostatic model assessment-insulin resistance (HOMA-IR) was analyzed. Results. Indexes, such as HOMA-IR, FINS, and SBP, were negatively correlated with serum 25(OH)D concentrations. Compared with the lowest quartile, individuals in the highest group had decreased Lg (HOMA-IR), Lg (FINS), and SBP. Pearson correlation analyses showed that serum 25(OH)D was negatively associated with age, BMI, Lg (HOMA-IR), and Lg (FINS). Multivariate linear regression analysis confirmed the negative correlation of Lg (HOMA-IR) and 25(OH)D. Conclusions. This study showed that serum 25(OH)D could be regarded as an independent predictor of insulin resistance for subjects without diabetes mellitus in China. Adequate vitamin D supplementation may improve multiple metabolic disturbances.

  3. Combined use of fasting plasma glucose and glycated hemoglobin A1c in a stepwise fashion to detect undiagnosed diabetes mellitus.

    PubMed

    Nakagami, Tomoko; Tominaga, Makoto; Nishimura, Rimei; Daimon, Makoto; Oizumi, Toshihide; Yoshiike, Nobuo; Tajima, Naoko

    2007-09-01

    Type 2 diabetes mellitus (DM) is a common and serious condition related with considerable morbidity. Screening for DM is one strategy for reducing this burden. In Japan National Diabetes Screening Program (JNDSP) guideline, the combined use of fasting plasma glucose (FPG) and glycated hemoglobin A1c (HbA1c) in a stepwise fashion has been recommended to identify the group of people needing life-style counseling or medical care. However, the efficacy of this program has not been fully evaluated, as an oral glucose tolerance test (OGTT) is not mandatory in the guideline. The aim of this study was to assess the validity of the screening test scenario, in which an OGTT would be applied to people needing life-style counseling or medical care on this guideline: FPG 110-125 mg/dl and HbA1c over 5.5%. Subjects were 1,726 inhabitants without a previous history of DM in the Funagata study, which is a population-based survey conducted in Yamagata prefecture to clarify the risk factors, related conditions, and consequences of DM. DM was diagnosed according to the 1999 World Health Organization criteria. The prevalence of undiagnosed DM was 6.6%. The tested screening scenario gave a sensitivity of 55.3%, a specificity of 98.4%, a positive predictive value of 70.8%, and a negative predictive value of 96.9% for undiagnosed DM. In conclusion, the screening test scenario, in which an OGTT would be followed by the combined use of FPG and HbA1c in a stepwise fashion according to the JNDSP guideline, was not effective in identifying people with undiagnosed DM.

  4. The Altered Mononuclear Cell-Derived Cytokine Response to Glucose Ingestion Is Not Regulated by Excess Adiposity in Polycystic Ovary Syndrome

    PubMed Central

    Sia, Chang Ling; Shepard, Marguerite K.; Rote, Neal S.; Minium, Judi

    2014-01-01

    Context: Excess adipose tissue is a source of inflammation. Polycystic ovary syndrome (PCOS) is a proinflammatory state and is often associated with excess abdominal adiposity (AA) alone and/or frank obesity. Objective: To determine the effect of glucose ingestion on cytokine release from mononuclear cells (MNC) in women with PCOS with and without excess AA and/or obesity. Design: A cross-sectional study. Setting: Academic medical center. Patients: Twenty-three women with PCOS (seven normal weight with normal AA, eight normal weight with excess AA, eight obese) and 24 ovulatory controls (eight normal weight with normal AA, eight normal weight with excess AA, eight obese). Intervention: Three-hour 75-g oral glucose tolerance test (OGTT). Main Outcome Measures: Body composition was measured by dual energy x-ray absorptiometry. Insulin sensitivity was derived from the OGTT (ISOGTT). TNFα, IL-6, and IL-1β release was measured in supernatants of cultured MNC isolated from blood samples drawn while fasting and 2 hours after glucose ingestion. Results: Insulin sensitivity was lower in obese subjects regardless of PCOS status and in normal-weight women with PCOS compared with normal-weight controls regardless of body composition status. In response to glucose ingestion, MNC-derived TNFα, IL-6, and IL-1β release decreased in both normal-weight control groups but failed to suppress in either normal-weight PCOS group and in obese women regardless of PCOS status. For the combined groups, the cytokine responses were negatively correlated with insulin sensitivity and positively correlated with abdominal fat and androgens. Conclusions: Women with PCOS fail to suppress MNC-derived cytokine release in response to glucose ingestion, and this response is independent of excess adiposity. Nevertheless, a similar response is also a feature of obesity per se. Circulating MNC and excess adipose tissue are separate and distinct sources of inflammation in this population. PMID:25078146

  5. Effects of rosglitazone on plasma adiponectin, insulin sensitivity, and insulin secretion in high-risk African Americans with impaired glucose tolerance test and type 2 diabetes.

    PubMed

    Osei, Kwame; Gaillard, Trudy; Kaplow, June; Bullock, Matthew; Schuster, Dara

    2004-12-01

    We examined the metabolic effects of rosiglitazone therapy on glucose control, insulin sensitivity, insulin secretion, and adiponectin in first-degree relatives of African Americans with type 2 diabetes (DM) with impaired glucose tolerance (IGT) and DM for 3 months. The study was comprised of 12 first-degree relatives with IGT, 17 newly diagnosed DM, and 19 healthy relatives with normal glucose tolerance (NGT). Oral glucose tolerance test (OGTT) was performed before and after 3 months of rosiglitazone therapy (4 to 8 mg/d) in patients with IGT and DM. Serum glucose, insulin, C-peptide, and adiponectin levels were measured before and 2 hours during OGTT in the NGT and patients with IGT and DM. Insulin resistance index (HOMA-IR) and beta-cell function (HOMA-%B) were calculated in each subject using homeostasis model assessment (HOMA). Rosglitazone improved the overall glycemic control in the IGT and DM groups. Following rosiglitazone, the beta-cell secretion remained unchanged, while HOMR-IR was reduced in DM by 30% (4.12 +/- 1.95 v 6.33 +/- 3.54, P < .05) and the IGT group (3.78 +/- 2.45 v 4.81 +/- 3.49, P = not significant [NS]). Mean plasma adiponectin levels were significantly (P < .05) lower in the DM (6.74 +/- 1.95 microg/mL) when compared with the NGT group(9.61 +/- 5.09). Rosiglitazone significantly (P < .001) increased adiponectin levels by 2-fold in patients with IGT (22.2 +/- 10.97 microg/mL) and 2.5-fold greater in DM (15.68 +/- 8.23 microg/mL) at 3 months when compared with the 0 month. We conclude that adiponectin could play a significant role (1) in the pathogenesis of IGT and DM and (2) the beneficial metabolic effects of thiazolidinediones (TZDs) in high-risk African American patients.

  6. Effects of stevioside on glucose transport activity in insulin-sensitive and insulin-resistant rat skeletal muscle.

    PubMed

    Lailerd, Narissara; Saengsirisuwan, Vitoon; Sloniger, Julie A; Toskulkao, Chaivat; Henriksen, Erik J

    2004-01-01

    Stevioside (SVS), a natural sweetener extracted from Stevia rebaudiana, has been used as an antihyperglycemic agent. However, little is known regarding its potential action on skeletal muscle, the major site of glucose disposal. Therefore, the purpose of the present study was to determine the effect of SVS treatment on skeletal muscle glucose transport activity in both insulin-sensitive lean (Fa/-) and insulin-resistant obese (fa/fa) Zucker rats. SVS was administered (500 mg/kg body weight by gavage) 2 hours before an oral glucose tolerance test (OGTT). Whereas the glucose incremental area under the curve (IAUC(glucose)) was not affected by SVS in lean Zucker rats, the insulin incremental area under the curve (IAUC(insulin)) and the glucose-insulin index (product of glucose and insulin IAUCs and inversely related to whole-body insulin sensitivity) were decreased (P<.05) by 42% and 45%, respectively. Interestingly, in the obese Zucker rat, SVS also reduced the IAUC(insulin) by 44%, and significantly decreased the IAUC(glucose) (30%) and the glucose-insulin index (57%). Muscle glucose transport was assessed following in vitro SVS treatment. In lean Zucker rats, basal glucose transport in type I soleus and type IIb epitrochlearis muscles was not altered by 0.01 to 0.1 mmol/L SVS. In contrast, 0.1 mmol/L SVS enhanced insulin-stimulated (2 mU/mL) glucose transport in both epitrochlearis (15%) and soleus (48%). At 0.5 mmol/L or higher, the SVS effect was reversed. Similarly, basal glucose transport in soleus and epitrochlearis muscles in obese Zucker rats was not changed by lower doses of SVS (0.01 to 0.1 mmol/L). However, these lower doses of SVS significantly increased insulin-stimulated glucose transport in both obese epitrochlearis and soleus (15% to 20%). In conclusion, acute oral SVS increased whole-body insulin sensitivity, and low concentrations of SVS (0.01 to 0.1 mmol/L) modestly improved in vitro insulin action on skeletal muscle glucose transport in both lean

  7. To Assess the Association between Glucose Metabolism and Ectopic Lipid Content in Different Clinical Classifications of PCOS

    PubMed Central

    Göbl, Christian S.; Ott, Johannes; Bozkurt, Latife; Feichtinger, Michael; Rehmann, Victoria; Cserjan, Anna; Heinisch, Maike; Steinbrecher, Helmut; JustKukurova, Ivica; Tuskova, Radka; Leutner, Michael; Vytiska-Binstorfer, Elisabeth; Kurz, Christine; Weghofer, Andrea; Tura, Andrea; Egarter, Christian; Kautzky-Willer, Alexandra

    2016-01-01

    Aims There are emerging data indicating an association between PCOS (polycystic ovary syndrome) and metabolic derangements with potential impact on its clinical presentation. This study aims to evaluate the pathophysiological processes beyond PCOS with particular focus on carbohydrate metabolism, ectopic lipids and their possible interaction. Differences between the two established classifications of the disease should be additionally evaluated. Methods A metabolic characterization was performed in 53 untreated PCOS patients as well as 20 controls including an extended oral glucose tolerance test (OGTT, to assess insulin sensitivity, secretion and ß-cell function) in addition to a detailed examination of ectopic lipid content in muscle and liver by nuclear magnetic resonance spectroscopy. Results Women with PCOS classified by the original NIH 1990 definition showed a more adverse metabolic risk profile compared to women characterized by the additional Rotterdam 2003 phenotypes. Subtle metabolic derangements were observed in both subgroups, including altered shapes of OGTT curves, impaired insulin action and hyperinsulinemia due to increased secretion and attenuated hepatic extraction. No differences were observed for ectopic lipids between the groups. However, particularly hepatocellular lipid content was significantly related to clinical parameters of PCOS like whole body insulin sensitivity, dyslipidemia and free androgen index. Conclusions Subtle alterations in carbohydrate metabolism are present in both PCOS classifications, but more profound in subjects meeting the NIH 1990 criteria. Females with PCOS and controls did not differ in ectopic lipids, however, liver fat was tightly related to hyperandrogenism and an adverse metabolic risk profile. PMID:27505055

  8. Associations between maternal BMI as well as glucose tolerance and adverse pregnancy outcomes in women with polycystic ovary syndrome.

    PubMed

    Li, Ying-Ying; Ye, Su-Qi; Zhong, Zhuo-Hui; Xu, Qiong; Mai, Wei-Bi; Yin, Cai-Xin; Zhu, Zhi-Qin; He, Xiao-Qian; Xiao, Qing

    2017-04-01

    This retrospective, cohort study examined the association between maternal pre-pregnancy body mass index (BMI), independent of glucose tolerance and adverse pregnancy outcomes in women with polycystic ovary syndrome (PCOS), for which there are few previous studies. Medical records from 2012 to 2015 at Guangzhou Women and Children's Medical Center, China were reviewed for women previously diagnosed with PCOS with normal 2-h 75-g oral glucose tolerance test (OGTT) results (n = 1249). The separate and joint effects of maternal BMI and glucose levels on pregnancy outcomes were assessed. Maternal pre-pregnancy BMI was associated with hypertensive disorders of pregnancy (HDP) (OR: 1.22, 95% CI: 1.02-1.45), preterm birth (OR: 1.49, 95% CI: 1.08-2.17), and large for gestational age (LGA) (OR: 1.69, 95% CI: 1.16-2.20). Elevated fasting glucose and maternal pre-pregnancy BMI were jointly associated with increased risks of HDP, preterm birth, and LGA. Therefore, among women with PCOS and normal glucose tolerance, maternal pre-pregnancy BMI is an independent risk factor of adverse pregnancy outcomes.

  9. GLUT2, glucose sensing and glucose homeostasis.

    PubMed

    Thorens, Bernard

    2015-02-01

    The glucose transporter isoform GLUT2 is expressed in liver, intestine, kidney and pancreatic islet beta cells, as well as in the central nervous system, in neurons, astrocytes and tanycytes. Physiological studies of genetically modified mice have revealed a role for GLUT2 in several regulatory mechanisms. In pancreatic beta cells, GLUT2 is required for glucose-stimulated insulin secretion. In hepatocytes, suppression of GLUT2 expression revealed the existence of an unsuspected glucose output pathway that may depend on a membrane traffic-dependent mechanism. GLUT2 expression is nevertheless required for the physiological control of glucose-sensitive genes, and its inactivation in the liver leads to impaired glucose-stimulated insulin secretion, revealing a liver-beta cell axis, which is likely to be dependent on bile acids controlling beta cell secretion capacity. In the nervous system, GLUT2-dependent glucose sensing controls feeding, thermoregulation and pancreatic islet cell mass and function, as well as sympathetic and parasympathetic activities. Electrophysiological and optogenetic techniques established that Glut2 (also known as Slc2a2)-expressing neurons of the nucleus tractus solitarius can be activated by hypoglycaemia to stimulate glucagon secretion. In humans, inactivating mutations in GLUT2 cause Fanconi-Bickel syndrome, which is characterised by hepatomegaly and kidney disease; defects in insulin secretion are rare in adult patients, but GLUT2 mutations cause transient neonatal diabetes. Genome-wide association studies have reported that GLUT2 variants increase the risks of fasting hyperglycaemia, transition to type 2 diabetes, hypercholesterolaemia and cardiovascular diseases. Individuals with a missense mutation in GLUT2 show preference for sugar-containing foods. We will discuss how studies in mice help interpret the role of GLUT2 in human physiology.

  10. The glucose oxidase-peroxidase assay for glucose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The glucose oxidase-peroxidase assay for glucose has served as a very specific, sensitive, and repeatable assay for detection of glucose in biological samples. It has been used successfully for analysis of glucose in samples from blood and urine, to analysis of glucose released from starch or glycog...

  11. Comparison of WHO and ADA criteria for diagnosis of glucose status in adults.

    PubMed

    Metcalf, P A; Scragg, R K

    2000-08-01

    The aim was to compare the 1997 American Diabetes Association (ADA) and 1985 and 1998 World Health Organisation (WHO) criteria for the diagnosis of diabetes and impaired glucose tolerance (IGT) by ethnicity and cardiovascular risk factors. We analysed the oral glucose tolerance tests carried out in a cross-sectional survey of 5816 New Zealand workers aged 22-78 years (4211 men, 1605 women) carried out between 1988 and 1990. Prevalence of diabetes was similar using ADA (3.1%) compared with the 1998 WHO criteria (3.0%). The overall prevalence rate of diabetes using the 1985 WHO criteria was only 1.5%. The prevalence rate of impaired fasting glucose (IFG) was the lowest in Europeans (7.3%) and highest in Asians (15.0%). The overall weighted kappa for agreement between the 1997 ADA and 1998 WHO criteria was moderate (0.59), but varied between ethnic groups. Cardiovascular disease (CVD) risk factors were approximately more adverse across groups with IFG, normal (ADA)/IGT (WHO), IFG/IGT and diabetes compared with normal subjects. Compared to those with IFG, participants with the normal (ADA)/IGT (WHO) criteria differed in fasting and 2-h glucose, diastolic blood pressure, and urinary albumin levels, and the proportions of males and number with hypertension, but had a significantly adverse pattern of CVD risk factors compared to those with normal glycaemia. The 1988 WHO criteria using the OGTT provides additional information for classifying various categories of glucose intolerance that is not captured using the 1997 ADA fasting glucose criteria alone.

  12. Impaired peripheral glucose sensing in F1 offspring of diabetic pregnancy.

    PubMed

    Kamel, Maher A; Helmy, Madiha H; Hanafi, Mervat Y; Mahmoud, Shimaa A; Abo Elfetooh, Hanan

    2014-09-01

    Maternal diabetes can induce permanent changes in glucose homeostasis that can occur pre- and post-natal and leads to type 2 diabetes in adulthood. This study aimed to investigate the effect of maternal diabetes on the F1 offspring peripheral glucose sensing and mitochondrial biogenesis in an attempt to clarify the mechanism of diabetogenic programming. Two groups of female Wistar rats were used (diabetic and control); diabetes was neonatally induced by STZ injection to 5-day old rats. After the pregnancy and delivery, the offspring were weaned to control diet or high-caloric (HCD) diet and followed up for 30 weeks. Every 5 weeks, OGTT was constructed, and serum and tissues were obtained for the assessment of mTFA, mtDNA, UCP2, insulin receptor (IR), phospho-insulin receptor (phospho-IR), and GLUT4. The result indicated impaired glucose tolerance (IGT) and insulin resistance in the offspring under control diet at the 15th week of age and thereafter while those offspring under HCD showed IGT at 10th week, and diabetes was evidenced at the 25th week of age. This defect in glucose metabolism was preceded by impairment in the phosphorylation of IR and decreased IR and Glut4 that cause impaired glucose sensing together with inhibited mitochondrial biogenesis in muscle and adipose tissues. This study indicated that maternal diabetes caused impaired glucose sensing and insulin resistance in the peripheral tissues and caused change in the expression of genes involved in mitochondrial biogenesis and function. Post-natal feeding with HCD may accelerate these changes. Male F1 offspring appears to be more sensitive than females for fetal programming of T2D.

  13. Glucose: detection and analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucose is an aldosic monosaccharide that is centrally entrenched in the processes of photosynthesis and respiration, serving as an energy reserve and metabolic fuel in most organisms. As both a monomer and as part of more complex structures such as polysaccharides and glucosides, glucose also pla...

  14. Evaluation of the effects of 80% methanolic leaf extract of Caylusea abyssinica (fresen.) fisch. & Mey. on glucose handling in normal, glucose loaded and diabetic rodents

    PubMed Central

    2012-01-01

    Background The leaves of Caylusea abyssinica (fresen.) Fisch. & Mey. (Resedaceae), a plant widely distributed in East African countries, have been used for management of diabetes mellitus in Ethiopian folklore medicine. However, its use has not been scientifically validated. The present study was undertaken to investigate antidiabetic effects of the hydroalcoholic leaf extract of C. abyssinica extract in rodents. Materials and method Male Animals were randomly divided into five groups for each diabetic, normoglycemic and oral glucose tolerance test (OGTT) studies. Group 1 served as controls and administered 2% Tween-80 in distilled water, (TW80); Group 2 received 5 mg/kg glibenclamide (GL5); Groups 3, 4 and 5 were given 100 (CA100), 200 (CA200) and 300 (CA300) mg/kg, respectively, of the hydroalcoholic extract of C. abyssinica. Blood samples were then collected at different time points to determine blood glucose levels (BGL). Data were analyzed using one way ANOVA followed by Dunnet’s post hoc test and p < 0.05was considered as statistically significant. Results In normal mice, CA200 and GL5 induced hypoglycemia starting from the 2nd h but the hypoglycemic effect of CA300 was delayed and appeared at the 4th h (p < 0.05 in all cases). In diabetic mice, BGL was significantly reduced by CA100 (p < 0.05) and CA300 (p < 0.01) starting from the 3rd h, whereas CA200 (p < 0.001) and GL5 (p < 0.05) attained this effect as early as the 2nd h. In OGTT, TW80 (p < 0.01) and CA100 (p < 0.01) brought down BGL significantly at 120 min, while CA200 (p < 0.001) and GL5 (p < 0.001) achieved this effect at 60 min indicating the oral glucose load improving activity of the extract. By contrast, CA300 was observed to have no effect on OGTT. Acute toxicity study revealed the safety of the extract even at a dose of 2000 mg/kg. Preliminary phytochemical study demonstrated the presence of various secondary metabolites, including, among others

  15. The interleukin-1 receptor antagonist anakinra improves first-phase insulin secretion and insulinogenic index in subjects with impaired glucose tolerance.

    PubMed

    van Poppel, P C M; van Asseldonk, E J P; Holst, J J; Vilsbøll, T; Netea, M G; Tack, C J

    2014-12-01

    Inflammation at the level of the β cell appears to be involved in progressive β-cell dysfunction in type 2 diabetes. We assessed the effect of blocking interleukin-1 (IL-1) by anakinra [recombinant human interleukin-1 receptor antagonist (IL-1Ra)] on β-cell function. Sixteen participants with impaired glucose tolerance were treated with 150 mg anakinra daily for 4 weeks in a double blind, randomized, placebo-controlled cross-over study with a wash-out period of 4 weeks. At the end of each treatment period, oral glucose tolerance tests (OGTTs) and hyperglycaemic clamps were performed. First-phase insulin secretion improved after anakinra treatment compared with placebo, 148 ± 20 versus 123 ± 14 mU/l, respectively (p = 0.03), and the insulinogenic index was higher after anakinra treatment. These results support the concept of involvement of IL-1β in the (progressive) decrease of insulin secretion capacity associated with type 2 diabetes.

  16. A probing dose of phenylacetate does not affect glucose production and gluconeogenesis in humans.

    PubMed

    Wajngot, A; Chandramouli, V; Schumann, W C; Brunengraber, H; Efendic, S; Landau, B R

    2000-09-01

    Phenylacetate ingestion has been used to probe Krebs cycle metabolism and to augment waste nitrogen excretion in urea cycle disorders. Phenylalkanoic acids, including phenylacetate, have been proposed as potential therapeutic agents in the treatment of diabetes. They inhibit gluconeogenesis in the liver in vitro and reduce the blood glucose concentration in diabetic rats. The effect of sodium phenylacetate ingestion on blood glucose and the contribution of gluconeogenesis to glucose production have now been studied in 7 type 2 diabetic patients. The study was not designed to test whether the changes in glucose metabolism observed in the rat could be reproduced in humans. After an overnight fast, over a period of 1 hour, 4.8 g phenylacetate was ingested, which is the highest dose used to probe Krebs cycle metabolism. Glucose production was measured by tracer kinetics using [6,6-(2)H2]glucose and gluconeogenesis by the labeling of the hydrogens of blood glucose on (2)H20 ingestion. The concentration of phenylacetate in plasma peaked by 2 hours after its ingestion, and about 40% of the dose was excreted in 5 hours. The plasma glucose concentration and production, and the contribution of gluconeogenesis to glucose production, were unaffected by phenylacetate ingestion at the highest dose used to probe Krebs cycle metabolism.

  17. Rare sugar D-psicose improves insulin sensitivity and glucose tolerance in type 2 diabetes Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

    PubMed

    Hossain, Mohammad A; Kitagaki, Shigeru; Nakano, Daisuke; Nishiyama, Akira; Funamoto, Yasunobu; Matsunaga, Toru; Tsukamoto, Ikuko; Yamaguchi, Fuminori; Kamitori, Kazuyo; Dong, Youyi; Hirata, Yuko; Murao, Koji; Toyoda, Yukiyasu; Tokuda, Masaaki

    2011-02-04

    A rare sugar, D-psicose has progressively been evaluated as a unique metabolic regulator of glucose and lipid metabolism, and thus represents a promising compound for the treatment of type 2 diabetes mellitus (T2DM). The present study was undertaken to examine the underlying effector organs of D-psicose in lowering blood glucose and abdominal fat by exploiting a T2DM rat model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Rats were fed 5% D-psicose or 5% D-glucose supplemented in drinking water, and only water in the control for 13 weeks and the protective effects were compared. A non-diabetic Long-Evans Tokushima Otsuka (LETO), fed with water served as a counter control of OLETF. After 13 weeks feeding, D-psicose treatment significantly reduced the increase in body weight and abdominal fat mass. Oral glucose tolerance test (OGTT) showed the reduced blood glucose and insulin levels suggesting the improvement of insulin resistance in OLETF rats. Oil-red-O staining elucidated that D-psicose significantly reduced lipid accumulation in the liver. Immunohistochemical analysis showed D-psicose induced glucokinase translocation from nucleus to cytoplasm of the liver which enhances glucokinase activity and subsequent synthesis of glycogen in the liver. D-psicose also protected the pathological change of the β-cells of pancreatic islets. These data demonstrate that D-psicose controls blood glucose levels by reducing lipotoxicity in liver and by preserving pancreatic β-cell function.

  18. Hepatic fat and abdominal adiposity in early pregnancy together predict impaired glucose homeostasis in mid-pregnancy

    PubMed Central

    De Souza, L R; Berger, H; Retnakaran, R; Vlachou, P A; Maguire, J L; Nathens, A B; Connelly, P W; Ray, J G

    2016-01-01

    Hepatic fat and abdominal adiposity individually reflect insulin resistance, but their combined effect on glucose homeostasis in mid-pregnancy is unknown. A cohort of 476 pregnant women prospectively underwent sonographic assessment of hepatic fat and visceral (VAT) and total (TAT) adipose tissue at 11–14 weeks' gestation. Logistic regression was used to assess the relation between the presence of maternal hepatic fat and/or the upper quartile (Q) of either VAT or TAT and the odds of developing the composite outcome of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or gestational diabetes mellitus at 24–28 weeks' gestation, based on a 75 g OGTT. Upon adjusting for maternal age, ethnicity, family history of DM and body mass index (BMI), the co-presence of hepatic fat and quartile 4 (Q4) of VAT (adjusted odds ratio (aOR) 6.5, 95% CI: 2.3–18.5) or hepatic fat and Q4 of TAT (aOR 7.8 95% CI 2.8–21.7) were each associated with the composite outcome, relative to women with neither sonographic feature. First-trimester sonographic evidence of maternal hepatic fat and abdominal adiposity may independently predict the development of impaired glucose homeostasis and GDM in mid-pregnancy. PMID:27643724

  19. Associations of lipid profiles with insulin resistance and β cell function in adults with normal glucose tolerance and different categories of impaired glucose regulation

    PubMed Central

    Ren, Xingxing; Han, Tingting; Chen, Yawen; Qiu, Huiying; Wu, Peihong; Zheng, Jun; Wang, Lihua; Liu, Wei; Hu, Yaomin

    2017-01-01

    Aims To investigate the associations of dyslipidemia with insulin resistance and β cell function in individuals with normal glucose tolerance (NGT) and different categories of impaired glucose regulation (IGR). Methods 544 subjects (365 with dyslipidemia and/or IGR and 179 with normal lipid and glucose tolerance) were enrolled in the study. All subjects underwent oral glucose tolerance test (OGTT). HOMA-IR was used to evaluate insulin sensitivity. Disposition index (DI) was used to evaluate β cell function. Multiple linear regression analysis was performed to assess correlations among lipid profiles, insulin resistance and β cell function. Results Among subjects with NGT, those with dyslipidemia had higher level of HOMA-IR but lower level of DI. While among subjects with different categories of IGR, those with dyslipidemia and CGI had significantly decreased DI. No obvious differences of insulin resistance or β cell function were found in IFG or IGT subjects with or without dyslipidemia. TG and HDL-C were correlated with HOMA-IR (β = 0.79, p <0.001; β = -0.38, p = 0.027, respectively, compared with subjects in the low level groups). Moreover, TG and TC were negatively correlated with DI (β = -2.17, p = 0.013; β = -2.01, p = 0.034 respectively, compared with subjects in the low level groups) after adjusting for confounding parameters. Conclusions Dyslipidemia induces insulin resistance and impaired β cell response to insulin resistance in individuals with NGT. Furthermore, dyslipidemia diminishes β cell function in subjects with CGI. TG and HDL-C were correlated with insulin resistance, and TG, TC were negatively correlated with β cell response to insulin resistance in non-diabetic individuals. PMID:28199386

  20. Recombinant glucose uptake system

    DOEpatents

    Ingrahm, Lonnie O.; Snoep, Jacob L.; Arfman, Nico

    1997-01-01

    Recombinant organisms are disclosed that contain a pathway for glucose uptake other than the pathway normally utilized by the host cell. In particular, the host cell is one in which glucose transport into the cell normally is coupled to PEP production. This host cell is transformed so that it uses an alternative pathway for glucose transport that is not coupled to PEP production. In a preferred embodiment, the host cell is a bacterium other than Z. mobilis that has been transformed to contain the glf and glk genes of Z. mobilis. By uncoupling glucose transport into the cell from PEP utilization, more PEP is produced for synthesis of products of commercial importance from a given quantity of biomass supplied to the host cells.

  1. Continuous Glucose Monitoring

    MedlinePlus

    ... la salud en español Health Statistics Healthy Moments Radio Broadcast Clinical Trials For Health Care Professionals Community ... A transmitter sends information about glucose levels via radio waves from the sensor to a pagerlike wireless ...

  2. Vascular Glucose Sensor Symposium

    PubMed Central

    Joseph, Jeffrey I; Torjman, Marc C.; Strasma, Paul J.

    2015-01-01

    Hyperglycemia, hypoglycemia, and glycemic variability have been associated with increased morbidity, mortality, length of stay, and cost in a variety of critical care and non–critical care patient populations in the hospital. The results from prospective randomized clinical trials designed to determine the risks and benefits of intensive insulin therapy and tight glycemic control have been confusing; and at times conflicting. The limitations of point-of-care blood glucose (BG) monitoring in the hospital highlight the great clinical need for an automated real-time continuous glucose monitoring system (CGMS) that can accurately measure the concentration of glucose every few minutes. Automation and standardization of the glucose measurement process have the potential to significantly improve BG control, clinical outcome, safety and cost. PMID:26078254

  3. Glucose: Detection and analysis.

    PubMed

    Galant, A L; Kaufman, R C; Wilson, J D

    2015-12-01

    Glucose is an aldosic monosaccharide that is centrally entrenched in the processes of photosynthesis and respiration, serving as an energy reserve and metabolic fuel in most organisms. As both a monomer and as part of more complex structures such as polysaccharides and glucosides, glucose also plays a major role in modern food products, particularly where flavor and or structure are concerned. Over the years, many diverse methods for detecting and quantifying glucose have been developed; this review presents an overview of the most widely employed and historically significant, including copper iodometry, HPLC, GC, CZE, and enzyme based systems such as glucose meters. The relative strengths and limitations of each method are evaluated, and examples of their recent application in the realm of food chemistry are discussed.

  4. Glucose urine test

    MedlinePlus

    Urine sugar test; Urine glucose test; Glucosuria test; Glycosuria test ... After you provide a urine sample, it is tested right away. The health care provider uses a dipstick made with a color-sensitive pad. The ...

  5. Glucose metabolism and hyperglycemia.

    PubMed

    Giugliano, Dario; Ceriello, Antonio; Esposito, Katherine

    2008-01-01

    Islet dysfunction and peripheral insulin resistance are both present in type 2 diabetes and are both necessary for the development of hyperglycemia. In both type 1 and type 2 diabetes, large, prospective clinical studies have shown a strong relation between time-averaged mean values of glycemia, measured as glycated hemoglobin (HbA1c), and vascular diabetic complications. These studies are the basis for the American Diabetes Association's current recommended treatment goal that HbA1c should be <7%. The measurement of the HbA1c concentration is considered the gold standard for assessing long-term glycemia; however, it does not reveal any information on the extent or frequency of blood glucose excursions, but provides an overall mean value only. Postprandial hyperglycemia occurs frequently in patients with diabetes receiving active treatment and can occur even when metabolic control is apparently good. Interventional studies indicate that reducing postmeal glucose excursions is as important as controlling fasting plasma glucose in persons with diabetes and impaired glucose tolerance. Evidence exists for a causal relation between postmeal glucose increases and microvascular and macrovascular outcomes; therefore, it is not surprising that treatment with different compounds that have specific effects on postprandial glucose regulation is accompanied by a significant improvement of many pathways supposed to be involved in diabetic complications, including oxidative stress, endothelial dysfunction, inflammation, and nuclear factor-kappaB activation. The goal of therapy should be to achieve glycemic status as near to normal as safely possible in all 3 components of glycemic control: HbA1c, fasting glucose, and postmeal glucose peak.

  6. An acoustic glucose sensor.

    PubMed

    Hu, Ruifen; Stevenson, Adrian C; Lowe, Christopher R

    2012-05-15

    In vivo glucose monitoring is required for tighter glycaemic control. This report describes a new approach to construct a miniature implantable device based on a magnetic acoustic resonance sensor (MARS). A ≈ 600-800 nm thick glucose-responsive poly(acrylamide-co-3-acrylamidophenylboronic acid) (poly(acrylamide-co-3-APB)) film was polymerised on the quartz disc (12 mm in diameter and 0.25 mm thick) of the MARS. The swelling/shrinking of the polymer film induced by the glucose binding to the phenylboronate caused changes in the resonance amplitude of the quartz disc in the MARS. A linear relationship between the response of the MARS and the glucose concentration in the range ≈ 0-15 mM was observed, with the optimum response of the MARS sensor being obtained when the polymer films contained ≈ 20 mol% 3-APB. The MARS glucose sensor also functioned under flow conditions (9 μl/min) with a response almost identical to the sensor under static or non-flow conditions. The results suggest that the MARS could offer a promising strategy for developing a small subcutaneously implanted continuous glucose monitor.

  7. Protein quality and quantity and insulin control of mammary gland glucose utilization during lactation

    SciTech Connect

    Masor, M.L.

    1987-01-01

    Virgin Sprague-Dawley rats were bred, and fed laboratory stock (STOCK), 13% casein plus methionine, 13% wheat gluten, or 5% casein plus methionine through gestation and 4 days of lactation. Diets were switched at parturition to determine the effects of dietary protein quality and quantity fed during gestation and/or lactation on insulin stimulation of mammary glucose utilization. On day 20 of gestation (20G) and day 4 of lactation (4L) the right inguinal-abdominal mammary glands were removed, and acini and tissue slices were incubated in Krebs buffer with or without insulin containing (U-/sup 14/C)-glucose and 5mM glucose for 1 hour at 37/degrees/C. Glucose incorporation into CO/sub 2/, lipid and lactose was determined. Glucose incorporation into CO/sub 2/ and lipid, but not lactose was stimulated by insulin in mammary slices. Diet effects on glucose utilization in acini were confirmed in slices for basal and insulin stimulated levels. Treatment affected the absolute increase of insulin stimulation. Regression analysis significantly correlated pup weight gain with total glucose utilization. Poor dietary protein quality and quantity fed during gestation impaired both overall response of mammary glucose utilization to insulin stimulation, and mammary development during pregnancy. Improving protein value at parturition did not overcome those deficits by 4L.

  8. A glucose sensor protein for continuous glucose monitoring.

    PubMed

    Veetil, Jithesh V; Jin, Sha; Ye, Kaiming

    2010-12-15

    In vivo continuous glucose monitoring has posed a significant challenge to glucose sensor development due to the lack of reliable techniques that are non- or at least minimally-invasive. In this proof-of-concept study, we demonstrated the development of a new glucose sensor protein, AcGFP1-GBPcys-mCherry, and an optical sensor assembly, capable of generating quantifiable FRET (fluorescence resonance energy transfer) signals for glucose monitoring. Our experimental data showed that the engineered glucose sensor protein can generate measurable FRET signals in response to glucose concentrations varying from 25 to 800 μM. The sensor developed based on this protein had a shelf-life of up to 3 weeks. The sensor response was devoid of interference from compounds like galactose, fructose, lactose, mannose, and mannitol when tested at physiologically significant concentrations of these compounds. This new glucose sensor protein can potentially be used to develop implantable glucose sensors for continuous glucose monitoring.

  9. Effects of different periods of paradoxical sleep deprivation and sleep recovery on lipid and glucose metabolism and appetite hormones in rats.

    PubMed

    Brianza-Padilla, Malinalli; Bonilla-Jaime, Herlinda; Almanza-Pérez, Julio César; López-López, Ana Laura; Sánchez-Muñoz, Fausto; Vázquez-Palacios, Gonzalo

    2016-03-01

    Sleep has a fundamental role in the regulation of energy balance, and it is an essential and natural process whose precise impacts on health and disease have not yet been fully elucidated. The aim of this study was to assess the consequences of different periods of paradoxical sleep deprivation (PSD) and recovery from PSD on lipid profile, oral glucose tolerance test (OGTT) results, and changes in insulin, corticosterone, ghrelin, and leptin concentrations. Three-month-old male Wistar rats weighing 250-350 g were submitted to 24, 96, or 192 h of PSD or 192 h of PSD with 480 h of recovery. The PSD was induced by the multiple platforms method. Subsequently, the animals were submitted to an OGTT. One day later, the animals were killed and the levels of triglycerides, total cholesterol, lipoproteins (low-density lipoprotein, very-low-density lipoprotein, and high-density lipoprotein), insulin, ghrelin, leptin, and corticosterone in plasma were quantified. There was a progressive decrease in body weight with increasing duration of PSD. The PSD induced basal hypoglycemia over all time periods evaluated. Evaluation of areas under the curve revealed progressive hypoglycemia only after 96 and 192 h of PSD. There was an increase in corticosterone levels after 192 h of PSD. We conclude that PSD induces alterations in metabolism that are reversed after a recovery period of 20 days.

  10. Effects of the Soluble Fiber Complex PolyGlycopleX on Glucose Homeostasis and Body Weight in Young Zucker Diabetic Rats.

    PubMed

    Grover, Gary James; Koetzner, Lee; Wicks, Joan; Gahler, Roland J; Lyon, Michael R; Reimer, Raylene A; Wood, Simon

    2011-01-01

    Dietary fiber can reduce insulin resistance, body weight, and hyperlipidemia depending on fiber type, water solubility, and viscosity. PolyGlycopleX(®) (PGX(®)) is a natural, novel water soluble, non-starch polysaccharide complex that with water forms a highly viscous gel compared to other naturally occurring dietary fiber. We determined the effect of dietary PGX(®) vs. cellulose and inulin on the early development of insulin resistance, body weight, hyperlipidemia, and glycemia-induced tissue damage in young Zucker diabetic rats (ZDFs) in fasted and non-fasted states. ZDFs (5 weeks old) were fed a diet containing 5% (wgt/wgt) cellulose, inulin, or PGX(®) for 8 weeks. Body weight, lipids, insulin, and glucose levels were determined throughout the study and homeostasis model assessment (HOMA) was used to measure insulin sensitivity throughout the study in fasted animals. At study termination, insulin sensitivity (oral glucose tolerance test, OGTT) and kidney, liver, and pancreatic histopathology were determined. Body weight and food intake were significantly reduced by PGX(®) vs. inulin and cellulose. Serum insulin in fasted and non-fasted states was significantly reduced by PGX(®) as was non-fasted blood glucose. Insulin resistance, measured as a HOMA score, was significantly reduced by PGX(®) in weeks 5 through 8 as well as terminal OGTT scores in fed and fasted states. Serum total cholesterol was also significantly reduced by PGX(®). PGX(®) significantly reduced histological kidney and hepatic damage in addition to reduced hepatic steatosis and cholestasis. A greater mass of pancreatic β-cells was found in the PGX(®) group. PGX(®) therefore may be a useful dietary additive in the control of the development of the early development of the metabolic syndrome.

  11. The unfolded protein response in human skeletal muscle is not involved in the onset of glucose tolerance impairment induced by a fat-rich diet.

    PubMed

    Deldicque, Louise; Van Proeyen, Karen; Francaux, Marc; Hespel, Peter

    2011-07-01

    Endoplasmic reticulum (ER) stress in pancreas, liver, and adipose tissue is a key event in the pathogenesis of obesity-related metabolic disease. Lipid-induced ER stress in liver and adipose tissue leads to inhibition of insulin signaling. Whether this mechanism exists in skeletal muscle is currently unknown. The present study aimed at assessing the ER stress response in skeletal muscle of subjects receiving a hyper-caloric fat-rich diet (HFD). Seven healthy males (20.6 ± 0.5 years; 70.9 ± 3.4 kg) volunteered to participate in the study. They received a hyper-caloric (+30% kcal) fat-rich (50% kcal) diet for 6 weeks. An oral glucose tolerance test (OGTT) was performed, and muscle biopsies were taken before and after HFD. HFD increased body mass by ~3 kg (P = 0.007) and the sum of skinfolds by 15% (P = 0.003). After HFD, blood glucose concentrations were higher during OGTT (two-way ANOVA, P = 0.023; +45% at 20 min, P = 0.002), and fasting plasma insulin level tended to be higher (+20%). HFD increased intramyocellular lipids content by ~50 and 75% in type I (P = 0.0009) and IIa fibers (P = 0.002), respectively. The protein expression of inositol-requiring enzyme 1α, protein kinase R-like ER protein kinase, BiP and calnexin and the mRNA level of spliced X box binding protein-1, CCAAT/enhancer binding protein homologous protein and activating transcription factor 4 were not changed after HFD. Despite the increase in body mass, subcutaneous fat deposits, and intramyocellular lipids content, ER stress markers were unchanged in skeletal muscle of subjects receiving a HFD for 6 weeks. This suggests that the onset of glucose intolerance is not related to ER stress in skeletal muscle.

  12. Continuous Glucose Monitoring

    PubMed Central

    Fritschi, Cynthia; Quinn, Laurie; Penckofer, Sue; Surdyk, Patricia M.

    2010-01-01

    Purpose The purpose of this descriptive study was to document the experience of wearing a continuous glucose monitoring (CGM) device in women with type 2 diabetes (T2DM). The availability of CGM has provided patients and clinicians with the opportunity to describe the immediate effects of diet, exercise, and medications on blood glucose levels; however, there are few data examining patients’ experiences and acceptability of using CGM. Methods Thirty-five women with T2DM wore a CGM for 3 days. Semistructured interviews were conducted to capture the self-described experience of wearing a CGM. Three open-ended questions were used to guide the participants’ self-reflection. Interviews were transcribed and analyzed. Results The women verbalized both positive and negative aspects of needing to check their blood glucose more frequently and wearing the monitor. After viewing the results, most women were surprised by the magnitude and frequency of blood glucose excursions. They immediately examined their behaviors during the time they wore the CGM. Independent problem-solving skills became apparent as they attempted to identify reasons for hyperglycemia by retracing food intake, physical activity, and stress experiences during the period of CGM. Most important, the majority of women stated they were interested in changing their diabetes-related self-care behaviors, especially eating and exercise behaviors, after reviewing their CGM results. Conclusions CGM is generally acceptable to women with T2DM and offers patients and their health care practitioners a possible alternative to routine glucose monitoring for assessing the effects of real-life events on blood glucose levels. PMID:20016057

  13. Sodium-glucose cotransport

    PubMed Central

    Poulsen, Søren Brandt; Fenton, Robert A.; Rieg, Timo

    2017-01-01

    Purpose of review Sodium-glucose cotransporters (SGLTs) are important mediators of glucose uptake across apical cell membranes. SGLT1 mediates almost all sodium-dependent glucose uptake in the small intestine, while in the kidney SGLT2, and to a lesser extent SGLT1, account for more than 90% and nearly 3%, respectively, of glucose reabsorption from the glomerular ultrafiltrate. Although the recent availability of SGLT2 inhibitors for the treatment of diabetes mellitus has increased the number of clinical studies, this review has a focus on mechanisms contributing to the cellular regulation of SGLTs. Recent findings Studies have focused on the regulation of SGLT expression under different physiological/pathophysiological conditions, for example diet, age or diabetes mellitus. Several studies provide evidence of SGLT regulation via cyclic adenosine monophosphate/protein kinase A, protein kinase C, glucagon-like peptide 2, insulin, leptin, signal transducer and activator of transcription-3 (STAT3), phosphoinositide-3 kinase (PI3K)/Akt, mitogen-activated protein kinases (MAPKs), nuclear factor-kappaB (NF-kappaB), with-no-K[Lys] kinases/STE20/SPS1-related proline/alanine-rich kinase (Wnk/SPAK) and regulatory solute carrier protein 1 (RS1) pathways. Summary SGLT inhibitors are important drugs for glycemic control in diabetes mellitus. Although the contribution of SGLT1 for absorption of glucose from the intestine as well as SGLT2/SGLT1 for renal glucose reabsorption has been comprehensively defined, this review provides an up-to-date outline for the mechanistic regulation of SGLT1/SGLT2. PMID:26125647

  14. Redundancy in Glucose Sensing

    PubMed Central

    Sharifi, Amin; Varsavsky, Andrea; Ulloa, Johanna; Horsburgh, Jodie C.; McAuley, Sybil A.; Krishnamurthy, Balasubramanian; Jenkins, Alicia J.; Colman, Peter G.; Ward, Glenn M.; MacIsaac, Richard J.; Shah, Rajiv; O’Neal, David N.

    2015-01-01

    Background: Current electrochemical glucose sensors use a single electrode. Multiple electrodes (redundancy) may enhance sensor performance. We evaluated an electrochemical redundant sensor (ERS) incorporating two working electrodes (WE1 and WE2) onto a single subcutaneous insertion platform with a processing algorithm providing a single real-time continuous glucose measure. Methods: Twenty-three adults with type 1 diabetes each wore two ERSs concurrently for 168 hours. Post-insertion a frequent sampling test (FST) was performed with ERS benchmarked against a glucose meter (Bayer Contour Link). Day 4 and 7 FSTs were performed with a standard meal and venous blood collected for reference glucose measurements (YSI and meter). Between visits, ERS was worn with capillary blood glucose testing ≥8 times/day. Sensor glucose data were processed prospectively. Results: Mean absolute relative deviation (MARD) for ERS day 1-7 (3,297 paired points with glucose meter) was (mean [SD]) 10.1 [11.5]% versus 11.4 [11.9]% for WE1 and 12.0 [11.9]% for WE2; P < .0001. ERS Clarke A and A+B were 90.2% and 99.8%, respectively. ERS day 4 plus day 7 MARD (1,237 pairs with YSI) was 9.4 [9.5]% versus 9.6 [9.7]% for WE1 and 9.9 [9.7]% for WE2; P = ns. ERS day 1-7 precision absolute relative deviation (PARD) was 9.9 [3.6]% versus 11.5 [6.2]% for WE1 and 10.1 [4.4]% for WE2; P = ns. ERS sensor display time was 97.8 [6.0]% versus 91.0 [22.3]% for WE1 and 94.1 [14.3]% for WE2; P < .05. Conclusions: Electrochemical redundancy enhances glucose sensor accuracy and display time compared with each individual sensing element alone. ERS performance compares favorably with ‘best-in-class’ of non-redundant sensors. PMID:26499476

  15. Spexin peptide is expressed in human endocrine and epithelial tissues and reduced after glucose load in type 2 diabetes.

    PubMed

    Gu, Liping; Ma, Yuhang; Gu, Mingyu; Zhang, Ying; Yan, Shuai; Li, Na; Wang, Yufan; Ding, Xiaoying; Yin, Jiajing; Fan, Nengguang; Peng, Yongde

    2015-09-01

    Spexin mRNA and protein are widely expressed in rat tissues and associate with weight loss in rodents of diet-induced obesity. Its location in endocrine and epithelial cells has also been suggested. Spexin is a novel peptide that involves weight loss in rodents of diet-induced obesity. Therefore, we aimed to examine its expression in human tissues and test whether spexin could have a role in glucose and lipid metabolism in type 2 diabetes mellitus (T2DM). The expression of the spexin gene and immunoreactivity in the adrenal gland, skin, stomach, small intestine, liver, thyroid, pancreatic islets, visceral fat, lung, colon, and kidney was higher than that in the muscle and connective tissue. Immunoreactive serum spexin levels were reduced in T2DM patients and correlated with fasting blood glucose (FBG, r=-0.686, P<0.001), hemoglobin A1c (HbA1c, r=-0.632, P<0.001), triglyceride (TG, r=-0.236, P<0.001) and low density lipoprotein-cholesterol (LDL-C, r=-0.382, P<0.001). A negative correlation of blood glucose with spexin was observed during oral glucose tolerance test (OGTT). Spexin is intensely expressed in normal human endocrine and epithelial tissues, indicating that spexin may be involved in physiological functions of endocrine and in several other tissues. Circulating spexin levels are low in T2DM patients and negatively related to blood glucose and lipids suggesting that the peptide may play a role in glucose and lipid metabolism in T2DM.

  16. Insulin resistance in first-trimester pregnant women with pre-pregnant glucose tolerance and history of recurrent spontaneous abortion.

    PubMed

    Hong, Y; Xie, Q X; Chen, C Y; Yang, C; Li, Y Z; Chen, D M; Xie, M Q

    2013-01-01

    Insulin resistance (IR) has been reported to play an important role in recurrent spontaneous abortion (RSA) among patients with polycystic ovary syndrome (PCOS). However, scanted materials exist regarding the independent effect of IR on RSA. The aim of this study is to investigate the status of IR in first trimester pregnant patients with normal pre-pregnant glucose tolerance and history of RSA. This two-center case-control study enrolled totally 626 first trimester pregnant women including 161 patients with a history of recurrent spontaneous abortion, who were pre-pregnantly glucose-tolerant according to oral glucose tolerance test (OGTT), and 465 women with no history of abnormal pregnancies of any kind. Clinical, biochemical and hormonal parameters were simultaneously measured in all participants. Serum beta-HCG, estradiol, progesterone, fasting plasma glucose and fasting plasma insulin levels, as well, the calculated homeostasis model assessment of insulin resistance index (HOMA-IR), fasting plasma glucose/insulin ratio(G/I) and pregnancy outcome were analyzed and compared. Serum beta-HCG and progesterone were found to be significantly lower in RSA group compared to controls. Subjects in RSA group were found to have higher HOMA-IR and lower G/I ratio than those in control group. Serum beta-HCG and progesterone were negatively correlated with HOMA-IR, and positively with G/I ratio even after adjustment for BMI. The spontaneous abortion rate within first trimester pregnancy of RSA patients was significantly higher than that in controls. In conclusion, woman with recurrent spontaneous abortion and normal pre-pregnant glucose metabolism tends to be more insulin resistant during first trimester pregnancy than healthy controls, no matter whether she has PCOS or not. Insulin resistance might be one of the direct causes that lead to recurrent abortion.

  17. Determination of the reference position in the near-infrared non-invasive blood glucose measurement in vivo

    NASA Astrophysics Data System (ADS)

    Han, Guang; Liu, Jin; Liu, Rong; Xu, Kexin

    2016-10-01

    Position-based reference measurement method is taken as one of the most promising method in non-invasive measurement of blood glucose based on spectroscopic methodology. Selecting an appropriate source-detector separation as the reference position is important for deducting the influence of background change and reducing the loss of useful signals. Our group proposed a special source-detector separation named floating-reference position where the signal contains only background change, that is to say, the signal at this source-detector separation is uncorrelated with glucose concentration. The existence of floating-reference position has been verified in a three layer skin by Monte Carlo simulation and in the in vitro experiment. But it is difficult to verify the existence of floating-reference position on the human body because the interference is more complex during in vivo experiment. Aiming at this situation, this paper studies the determination of the best reference position on human body by collecting signals at several source-detector separations on the palm and measuring the true blood glucose levels during oral glucose tolerance test (OGTT) experiments of 3 volunteers. Partial least square (PLS) calibration model is established between the signals at every source-detector separation and its corresponding blood glucose levels. The results shows that the correlation coefficient (R) between 1.32 mm to 1.88 mm is lowest and they can be used as reference for background correction. The signal of this special position is important for improving the accuracy of near-infrared non-invasive blood glucose measurement.

  18. Prevention of diabetes and cardiovascular disease in patients with impaired glucose tolerance: rationale and design of the Nateglinide And Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) Trial.

    PubMed

    Califf, Robert M; Boolell, Mitradev; Haffner, Steven M; Bethel, M Angelyn; McMurray, John; Duggal, Anil; Holman, Rury R

    2008-10-01

    Patients with impaired glucose tolerance (IGT) have increased risk for developing type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Lifestyle modification and medication can prevent or delay progression to diabetes (PD), but whether such interventions also reduce the risk of CVD has not been rigorously tested. The Nateglinide And Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial is a multinational, randomized, double-blind, 2 x 2 factorial trial in subjects with IGT (on a screening oral glucose tolerance test [OGTT]) aged > or = 50 years with known CVD or aged > or = 55 years with > or = 1 CVD risk factor. Enrollment began in January 2002 and was completed January 2004, with 9,518 patients randomized to receive 1 of 4 possible treatment combinations as follows: nateglinide with valsartan, nateglinide with valsartan-placebo, nateglinide-placebo with valsartan, or nateglinide-placebo with valsartan-placebo. All subjects are participating in a clinic-based and telephone-based lifestyle intervention aimed at reducing weight and dietary fat and increasing physical activity. The 3 coprimary end points are new onset of T2DM, a "core" composite of major cardiovascular events (death, myocardial infarction, stroke, or hospitalization for heart failure), and an "extended" composite including the components of the core composite plus coronary revascularization and hospitalization for unstable angina. The study was designed to evaluate whether reducing postprandial hyperglycemia, blockade of the renin-angiotensin-aldosterone system, or both interventions reduce the risk of T2DM or cardiovascular events in patients with IGT.

  19. Glucose-6-phosphate dehydrogenase

    MedlinePlus

    ... Elsevier Saunders; 2012:chap 42. Read More Enzyme Glucose-6-phosphate dehydrogenase deficiency Hemoglobin Review Date 2/11/2016 Updated by: ... A.M. Editorial team. Related MedlinePlus Health Topics G6PD Deficiency Browse the Encyclopedia A.D.A.M., Inc. ...

  20. Glucose Tolerance and Hyperkinesis.

    ERIC Educational Resources Information Center

    Langseth, Lillian; Dowd, Judith

    Examined were medical records of 265 hyperkinetic children (7-9 years old). Clinical blood chemistries, hematology, and 5-hour glucose tolerance test (GTT) results indicated that hematocrit levels were low in 27% of the Ss, eosinophil levels were abnormally high in 86% of the Ss, and GTT results were abnormal in a maority of Ss. (CL)

  1. Thiazolidinediones increase hepatic insulin extraction in African Americans with impaired glucose tolerance and type 2 diabetes mellitus. A pilot study of rosiglitazone.

    PubMed

    Osei, Kwame; Gaillard, Trudy; Schuster, Dara

    2007-01-01

    Peripheral insulin levels are determined by beta-cell secretion, insulin sensitivity, and hepatic insulin extraction (HIE). We have previously shown that whereas sulfonylureas reduce insulin extraction, metformin enhances HIE. However, the effects of thiazolidinediones (TZDs) on HIE remain uncertain. Thus, we investigated the potential contribution of hepatic insulin clearance to peripheral insulin levels during rosiglitazone therapy in African Americans with impaired glucose tolerance (IGT) and type 2 diabetes mellitus (DM). The study was composed of 12 first-degree relatives with IGT and 17 patients with newly diagnosed type 2 DM. Nineteen healthy relatives with normal glucose tolerance served as controls. Serum glucose, insulin, and C-peptide, and HIE (C-peptide-insulin molar ratios) were measured at t = 0 and 120 minutes during oral glucose tolerance test (OGTT) in all the subjects. The OGTT was performed before and after 3 months of rosiglitazone therapy (4 mg/d x 4 weeks and >8 mg/d x 8 weeks) in patients with IGT and type 2 DM. Insulin resistance index and beta-cell function were calculated in each subject using homeostasis model assessment (HOMA). Rosiglitazone therapy improved but did not normalize the overall glycemic control in the IGT and type 2 DM groups. After rosiglitazone therapy, the mean serum insulin and C-peptide levels at fasting remained unchanged. However, the 2-hour serum glucose and insulin were lower, whereas serum C-peptide was unchanged during 3 months of rosiglitazone treatment. Mean insulin resistance index of HOMA was reduced by 30% (4.12 +/- 1.95 vs 6.33 +/- 3.54, P < .05) in the type 2 DM group and by 21% (3.78 +/- 2.45 vs 4.81 +/- 3.49, P = NS) in the IGT group. Mean HIE values were significantly lower (70%) in the type 2 DM and IGT groups when compared with the normal glucose tolerance group. At 3 months, basal HIE was not significantly changed by rosiglitazone therapy in IGT and type 2 DM groups when compared with the baseline (0

  2. Circulating C1q complement/TNF-related protein (CTRP) 1, CTRP9, CTRP12 and CTRP13 concentrations in Type 2 diabetes mellitus: In vivo regulation by glucose

    PubMed Central

    Zhang, Man Man; Tan, Bee Kang; Chen, Jing

    2017-01-01

    Objectives The C1q complement/TNF-related protein (CTRP) superfamily, which includes the adipokine adiponectin, has been shown in animal models to have positive metabolic and cardiovascular effects. We sought to investigate circulating CTRP1, CTRP9, CTRP12 and CTRP13 concentrations in persons with type 2 diabetes mellitus (T2DM), with age and BMI matched controls, and to examine the effects of a 2 hour 75g oral glucose tolerance test (OGTT) on serum CTRP1, CTRP9, CTRP12 and CTRP13 levels in persons with T2DM. Design Cross-sectional study [newly diagnosed T2DM (n = 124) and control (n = 139) participants]. Serum CTRP1, CTRP9, CTRP12 and CTRP13 were measured by ELISA. Results Systolic and diastolic blood pressure, total cholesterol (TCH), Low-density lipoprotein (LDL)-cholesterol, triglycerides, TCH/High-density lipoprotein (HDL) ratio, triglycerides/HDL ratio, glucose, insulin, homeostatic model assessment–insulin resistance (HOMA-IR), C-reactive protein and endothelial lipase were significantly higher, whereas leptin and adiponectin were significantly lower in T2DM participants. Serum CTRP1 were significantly higher and CTRP12 significantly lower in T2DM participants. Age, diastolic blood pressure, glucose and CTRP12 were predictive of serum CTRP1; leptin was predictive of serum CTRP9; glucose and CTRP1 were predictive of serum CTRP12; endothelial lipase was predictive of serum CTRP13. Finally, serum CTRP1 were significantly higher and CTRP12 significantly lower in T2DM participants after a 2 hour 75g OGTT. Conclusions Our data supports CTRP1 and CTRP12 as potential novel biomarkers for the prediction and early diagnosis of T2DM. Furthermore, pharmacological agents that target CTRP1 and CTRP12 could represent a new strategy in the treatment of T2DM. PMID:28207876

  3. Impact of Vitamin D Replacement on Markers of Glucose Metabolism and Cardio-Metabolic Risk in Women with Former Gestational Diabetes--A Double-Blind, Randomized Controlled Trial.

    PubMed

    Yeow, Toh Peng; Lim, Shueh Lin; Hor, Chee Peng; Khir, Amir S; Wan Mohamud, Wan Nazaimoon; Pacini, Giovanni

    2015-01-01

    Gestational Diabetes Mellitus (GDM) and vitamin D deficiency are related to insulin resistance and impaired beta cell function, with heightened risk for future development of diabetes. We evaluated the impact of vitamin D supplementation on markers of glucose metabolism and cardio metabolic risk in Asian women with former GDM and hypovitaminosis D. In this double blind, randomized controlled trial, 26 participants were randomized to receive either daily 4000 IU vitamin D3 or placebo capsules. 75 g Oral Glucose Tolerance Test (OGTT) and biochemistry profiles were performed at baseline and 6 month visits. Mathematical models, using serial glucose, insulin and C peptide measurements from OGTT, were employed to calculate insulin sensitivity and beta cell function. Thirty three (76%) women with former GDM screened had vitamin D level of <50 nmol/L at baseline. Supplementation, when compared with placebo, resulted in increased vitamin D level (+51.1 nmol/L vs 0.2 nmol/L, p<0.001) and increased fasting insulin (+20% vs 18%, p = 0.034). The vitamin D group also demonstrated a 30% improvement in disposition index and an absolute 0.2% (2 mmol/mol) reduction in HbA1c. There was no clear change in insulin sensitivity or markers of cardio metabolic risk. This study highlighted high prevalence of vitamin D deficiency among Asian women with former GDM. Six months supplementation with 4000 IU of vitamin D3 safely restored the vitamin D level, improved basal pancreatic beta-cell function and ameliorated the metabolic state. There was no effect on markers of cardio metabolic risk. Further mechanistic studies exploring the role of vitamin D supplementation on glucose homeostasis among different ethnicities may be needed to better inform future recommendations for these women with former GDM at high risk of both hypovitaminosis D and future diabetes.

  4. Glucose and Aging

    NASA Astrophysics Data System (ADS)

    Ely, John T. A.

    2008-04-01

    When a human's enzymes attach glucose to proteins they do so at specific sites on a specific molecule for a specific purpose that also can include ascorbic acid (AA) at a high level such as 1 gram per hour during exposure. In an AA synthesizing animal the manifold increase of AA produced in response to illness is automatic. In contrast, the human non-enzymatic process adds glucose haphazardly to any number of sites along available peptide chains. As Cerami clarified decades ago, extensive crosslinking of proteins contributes to loss of elasticity in aging tissues. Ascorbic acid reduces the random non-enyzmatic glycation of proteins. Moreover, AA is a cofactor for hydroxylase enzymes that are necessary for the production and replacement of collagen and other structural proteins. We will discuss the relevance of ``aging is scurvy'' to the biochemistry of human aging.

  5. Liver glucose metabolism in humans

    PubMed Central

    Adeva-Andany, María M.; Pérez-Felpete, Noemi; Fernández-Fernández, Carlos; Donapetry-García, Cristóbal; Pazos-García, Cristina

    2016-01-01

    Information about normal hepatic glucose metabolism may help to understand pathogenic mechanisms underlying obesity and diabetes mellitus. In addition, liver glucose metabolism is involved in glycosylation reactions and connected with fatty acid metabolism. The liver receives dietary carbohydrates directly from the intestine via the portal vein. Glucokinase phosphorylates glucose to glucose 6-phosphate inside the hepatocyte, ensuring that an adequate flow of glucose enters the cell to be metabolized. Glucose 6-phosphate may proceed to several metabolic pathways. During the post-prandial period, most glucose 6-phosphate is used to synthesize glycogen via the formation of glucose 1-phosphate and UDP–glucose. Minor amounts of UDP–glucose are used to form UDP–glucuronate and UDP–galactose, which are donors of monosaccharide units used in glycosylation. A second pathway of glucose 6-phosphate metabolism is the formation of fructose 6-phosphate, which may either start the hexosamine pathway to produce UDP-N-acetylglucosamine or follow the glycolytic pathway to generate pyruvate and then acetyl-CoA. Acetyl-CoA may enter the tricarboxylic acid (TCA) cycle to be oxidized or may be exported to the cytosol to synthesize fatty acids, when excess glucose is present within the hepatocyte. Finally, glucose 6-phosphate may produce NADPH and ribose 5-phosphate through the pentose phosphate pathway. Glucose metabolism supplies intermediates for glycosylation, a post-translational modification of proteins and lipids that modulates their activity. Congenital deficiency of phosphoglucomutase (PGM)-1 and PGM-3 is associated with impaired glycosylation. In addition to metabolize carbohydrates, the liver produces glucose to be used by other tissues, from glycogen breakdown or from de novo synthesis using primarily lactate and alanine (gluconeogenesis). PMID:27707936

  6. Effect of a deacyl gymnemic acid on glucose homeostasis & metabolic parameters in a rat model of metabolic syndrome

    PubMed Central

    Bhansali, Shobhit; Shafiq, Nusrat; Pandhi, Promila; Singh, Amrit Pal; Singh, Inderjeet; Singh, Pawan Kumar; Sharma, Sadhna; Malhotra, Samir

    2013-01-01

    Background & objectives: Metabolic syndrome (MS) comprises several cardio-metabolic risk factors, which include obesity, hypertension, hyperglycaemia, hypertriglyceridaemia and decreased HDL cholesterol. Leaf extract of Gymnema sylvestre has been shown to possess glucose lowering activity in animal models. This study was carried out to evaluate the efficacy of deacyl gymnemic acid (DAGA), active constituent of G. sylvestre, in a rat model of MS. Methods: Six groups consisting of six wistar rats in each, were studied. Group I received the normal diet, while the remaining five groups received high fructose diet (HFD) for 20 days to induce MS. HFD was continued in these five groups for the next 20 days along with group II received vehicle solution, group III received pioglitazone and groups IV- VI received DAGA in variable doses. Systolic blood pressure (SBP) was measured using tail-cuff method. Oral glucose tolerance test (OGTT) was done at baseline and at days 20 and 40. Blood samples were collected for glucose, insulin and lipid profile. Results: Administration of HFD for 20 days resulted in weight gain (>10%), increase in SBP, fasting plasma glucose (FPG) and triglycerides fulfilling the criteria for MS. Administration of DAGA (200 mg/kg) reduced SBP and significantly improved the FPG and HOMA-IR (homeostatis model assessment-insulin resistance) with modest improvement in lipid profile without decrease in body weight similar to pioglitazone. Interpretation & conclusions: Our findings show that DAGA decreases SBP and improves parameters of glucose-insulin homeostasis in a rat model of MS induced by HFD. Further studies are required to elucidate the mechanism of action. PMID:23852298

  7. Insulin sensitivity and first-phase insulin secretion in obese Chinese with hyperglycemia in 30 and/or 60 min during glucose tolerance tests.

    PubMed

    Hong, Jie; Zhang, Yi-Fei; Gu, Wei-qiong; Zhang, Yu-wen; Su, Yu-xia; Chi, Zhen-ni; Wang, Wei-qing; Li, Xiao-ying; Ning, Guang

    2008-01-01

    The purpose of this study was to investigate insulin sensitivity and first-phase insulin secretion in obesity with hyperglycemia in 30 and/or 60 min during oral glucose tolerance (OGTT, glucose > or = 11.1 mmol/l, post-loading hyperglycemia, PLH) in Chinese population. A total of 196 nondiabetic subjects were included in the present study, among them 99 had normal glucose tolerance (NGT, subdivided into 32 lean NGT and 67 obese NGT), 74 had obesity with impaired glucose tolerance (IGT) and 23 had obesity with PLH. A standard 75-g oral glucose tolerance test was performed after fasting and at 30 min, 1, 2 and 3 h. Insulin sensitivity index (S(I)) was assessed by the Bergman's minimal model method with frequently sampled intravenous glucose tolerance test (FSIGTT), insulin secretion was determined by acute insulin response to glucose (AIRg). The disposition index (DI), the product of AIRg and S(I) was used to determine whether AIRg was adequate to compensate for insulin resistance. S(I) was significantly equally lower in three obese subgroups. AIRg was significantly increased in obese NGT as compared with lean NGT controls, and reduced to the same extent in IGT and PLH subjects. There was no significant difference among lean NGT, IGT and PLH subjects. DI value was reduced from obese NGT individuals, IGT and PLH subjects had a similar lower level of DI. In conclusion, our present results demonstrated that the pathophysiological basis of obese subjects with PLH were clearly insulin resistance and defective in first-phase insulin secretion as that in IGT subjects in Chinese population.

  8. Silver nanoparticles affect glucose metabolism in hepatoma cells through production of reactive oxygen species

    PubMed Central

    Lee, Mi Jin; Lee, Seung Jun; Yun, Su Jin; Jang, Ji-Young; Kang, Hangoo; Kim, Kyongmin; Choi, In-Hong; Park, Sun

    2016-01-01

    The silver nanoparticle (AgNP) is a candidate for anticancer therapy because of its effects on cell survival and signaling. Although numerous reports are available regarding their effect on cell death, the effect of AgNPs on metabolism is not well understood. In this study, we investigated the effect of AgNPs on glucose metabolism in hepatoma cell lines. Lactate release from both HepG2 and Huh7 cells was reduced with 5 nm AgNPs as early as 1 hour after treatment, when cell death did not occur. Treatment with 5 nm AgNPs decreased glucose consumption in HepG2 cells but not in Huh7 cells. Treatment with 5 nm AgNPs reduced nuclear factor erythroid 2-like 2 expression in both cell types without affecting its activation at the early time points after AgNPs’ treatment. Increased reactive oxygen species (ROS) production was detected 1 hour after 5 nm AgNPs’ treatment, and lactate release was restored in the presence of an ROS scavenger. Our results suggest that 5 nm AgNPs affect glucose metabolism by producing ROS. PMID:26730190

  9. Silver nanoparticles affect glucose metabolism in hepatoma cells through production of reactive oxygen species.

    PubMed

    Lee, Mi Jin; Lee, Seung Jun; Yun, Su Jin; Jang, Ji-Young; Kang, Hangoo; Kim, Kyongmin; Choi, In-Hong; Park, Sun

    2016-01-01

    The silver nanoparticle (AgNP) is a candidate for anticancer therapy because of its effects on cell survival and signaling. Although numerous reports are available regarding their effect on cell death, the effect of AgNPs on metabolism is not well understood. In this study, we investigated the effect of AgNPs on glucose metabolism in hepatoma cell lines. Lactate release from both HepG2 and Huh7 cells was reduced with 5 nm AgNPs as early as 1 hour after treatment, when cell death did not occur. Treatment with 5 nm AgNPs decreased glucose consumption in HepG2 cells but not in Huh7 cells. Treatment with 5 nm AgNPs reduced nuclear factor erythroid 2-like 2 expression in both cell types without affecting its activation at the early time points after AgNPs' treatment. Increased reactive oxygen species (ROS) production was detected 1 hour after 5 nm AgNPs' treatment, and lactate release was restored in the presence of an ROS scavenger. Our results suggest that 5 nm AgNPs affect glucose metabolism by producing ROS.

  10. Coconut-derived D-xylose affects postprandial glucose and insulin responses in healthy individuals

    PubMed Central

    Bae, Yun Jung; Bak, Youn-Kyung; Kim, Bumsik; Kim, Min-Sun; Lee, Jin-Hee

    2011-01-01

    Metabolic alterations including postprandial hyperglycemia have been implicated in the development of obesity-related diseases. Xylose is a sucrase inhibitor suggested to suppress the postprandial glucose surge. The objectives of this study were to assess the inhibitory effects of two different concentrations of xylose on postprandial glucose and insulin responses and to evaluate its efficacy in the presence of other macronutrients. Randomized double-blind cross-over studies were conducted to examine the effect of D-xylose on postprandial glucose and insulin response following the oral glucose tolerance test (OGTT). In study 1, the overnight-fasted study subjects (n = 49) consumed a test sucrose solution (50 g sucrose in 130 ml water) containing 0, 5, or 7.5 g D-xylose powder. In study 2, the overnight-fasted study subjects (n = 50) consumed a test meal (50 g sucrose in a 60 g muffin and 200 ml sucrose-containing solution). The control meal provided 64.5 g of carbohydrates, 4.5 g of fat, and 10 g of protein. The xylose meal was identical to the control meal except 5 g of xylose was added to the muffin mix. In study 1, the 5 g xylose-containing solutions exhibited significantly lower area under the glucose curve (AUCg) and area under the insulin curve (AUCi) values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P < 0.0001), 0-60 min (P < 0.0001, P < 0.0001), 0-90 min (P < 0.0001, P < 0.0001) and 0-120 min (P = 0.0071, P = 0.0016). In study 2, the test meal exhibited significantly lower AUCg and AUCi values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P = 0.0005), 0-60 min (P = 0.0002, P = 0.0025), and 0-90 min (P = 0.0396, P = 0.0246). In conclusion, xylose showed an acute suppressive effect on the postprandial glucose and insulin surges. PMID:22259678

  11. INSULIN RESISTANCE IS ASSOCIATED WITH ALZHEIMER-LIKE REDUCTIONS IN REGIONAL CEREBRAL GLUCOSE METABOLISM FOR COGNITIVELY NORMAL ADULTS WITH PRE-DIABETES OR EARLY TYPE 2 DIABETES

    PubMed Central

    Baker, Laura D.; Cross, Donna; Minoshima, Satoshi; Belongia, Dana; Watson, G. Stennis; Craft, Suzanne

    2010-01-01

    Background Insulin resistance is a causal factor in pre-diabetes and type 2 diabetes (T2D), and also increases the risk of developing Alzheimer’s disease (AD). Reductions in cerebral glucose metabolic rate (CMRglu) as measured by fluorodeoxyglucose positron emission tomography (FDG PET) in parietotemporal, frontal, and cingulate cortex are also associated with increased AD risk, and can be observed years before dementia onset. Objectives We examined whether greater insulin resistance as indexed by the homeostasis model assessment (HOMA-IR) would be associated with reduced resting CMRglu in areas known to be vulnerable in AD in a sample of cognitively normal adults with newly diagnosed pre-diabetes or T2D (P-D/T2D). We also determined whether P-D/T2D adults have abnormal patterns of CMRglu during a memory encoding task. Design Randomized crossover design of resting and activation [F-18] FDG-PET. Setting University Imaging Center and VA Clinical Research Unit. Participants Participants included 23 older adults (mean age±SEM=74.4±1.4) with no prior diagnosis of or treatment for diabetes, but who met American Diabetes Association glycemic criteria for pre-diabetes (n=11) or diabetes (n=12) based on fasting or 2-h oral glucose tolerance test (OGTT) glucose values, and 6 adults (mean age±SEM=74.3±2.8) with normal fasting glucose and glucose tolerance. No participant met Petersen criteria for mild cognitive impairment (MCI). Intervention Fasting participants rested with eyes open in a dimly lit room and underwent resting and cognitive activation [F-18]FDG PET imaging on separate days, in randomized order, at 9 am. Following a 30-min transmission scan, subjects received an intravenous injection of 5 mCi [F-18]FDG, and the emission scan commenced 40 min post-injection. In the activation condition, a 35-min memory encoding task was initiated at the time of tracer injection. Subjects were instructed to remember a repeating list of 20 words that were randomly presented

  12. Glucose repression in Saccharomyces cerevisiae

    PubMed Central

    Kayikci, Ömur; Nielsen, Jens

    2015-01-01

    Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective at post-transcriptional and post-translational levels. This review describes effects of glucose repression on yeast carbon metabolism with a focus on roles of the Snf3/Rgt2 glucose-sensing pathway and Snf1 signal transduction in establishment and relief of glucose repression. PMID:26205245

  13. Optoelectronic Apparatus Measures Glucose Noninvasively

    NASA Technical Reports Server (NTRS)

    Ansari, Rafat R.; Rovati, Luigi L.

    2003-01-01

    An optoelectronic apparatus has been invented as a noninvasive means of measuring the concentration of glucose in the human body. The apparatus performs polarimetric and interferometric measurements of the human eye to acquire data from which the concentration of glucose in the aqueous humor can be computed. Because of the importance of the concentration of glucose in human health, there could be a large potential market for instruments based on this apparatus.

  14. How well are pregnant women in Croatia informed about the oral glucose tolerance test?

    PubMed Central

    Kocijancic, Marija

    2015-01-01

    Introduction Preanalytical errors still constitute the largest source of errors in laboratory work. Proper patient preparation and patient’s knowledge about a particular procedure affects its accuracy and reliability. We hypothesized that most of pregnant women are not well enough informed about the proper procedure for the OGTT. The aims of this study were to investigate: (i) how well pregnant women are informed about the OGTT; (ii) the most common way to inform pregnant women about OGTT and (iii) whether pregnant women’s level of knowledge about the OGTT differ regarding source of information. Materials and methods The anonymous questionnaire was conducted across the country in 23 Croatian primary and secondary healthcare centres. The questionnaire contained 9 questions on certain demographic data and familiarity with OGTT procedure. All 343 participants filled the questionnaire before the first blood draw. Results 42% of the participants demonstrated high and 38% adequate level of knowledge about the OGTT procedure. Majority of participants were informed about the procedure by gynaecologist (56%). The level of knowledge differed among participants with different sources of information (P = 0.030). Further analysis showed that the level of knowledge was lower in pregnant women having received information from their gynaecologist compared to pregnant women who received information from the laboratory staff. Conclusions In general, pregnant women are familiar with OGTT procedure, main source of information about the OGTT procedure is their gynaecologist, but the level of knowledge was higher in women who received information about the OGTT procedure from the laboratory staff. PMID:26110035

  15. [Glucose homeostasis in children. I. Regulation of blood glucose].

    PubMed

    Otto Buczkowska, E; Szirer, G; Jarosz-Chobot, P

    2001-01-01

    The amount of glucose in the circulation depends on its absorption from the intestine, uptake by and release from the liver and uptake by peripheral tissues. Insulin and glucagon together control the metabolities required by peripheral tissues and both are involved in maintaining glucose homeostasis. Insulin is considered to be an anabolic hormone in that it promotes the synthesis of protein, lipid and glycogen. The key target tissues for insulin are liver, muscles and adipose tissue. Glucagon acts largely to increase catabolic processes. Between meals or during fast, the most tightly regulated process is the release of glucose from the liver. During fasting glucose is produced from glycogen and is formed by enzymes on the gluconeogenic pathway. Fetal metabolism is directed to ensure anabolism with formation of glycogen, fat and protein. Glucogen is stored in the liver and serves as the immediate source of new glucose during first few hours after birth. Glucose is the most important substrate for brain metabolism. Due to the large size of neonatal brain in relation to body weight cerebral glucose consumption is particularly high. Postnatal hormonal changes have a central role in regulating glucose mobilization through glycogenolysis and gluconeogenesis. The initial glucagon surge is the key adaptive change which triggers the switch to glucose production. The control of insulin and glucagon secretion is of fundamental importance during first hours after birth. Children have a decreased tolerance to starvation when compared with adults, they are more prone to develop hypoglycaemia after short fasting. The faster rate in the fall of blood glucose and gluconeogenic substrates and rapid rate of ketogenesis are characteristic features of fasting adaptation in children.

  16. Alginate cryogel based glucose biosensor

    NASA Astrophysics Data System (ADS)

    Fatoni, Amin; Windy Dwiasi, Dian; Hermawan, Dadan

    2016-02-01

    Cryogel is macroporous structure provides a large surface area for biomolecule immobilization. In this work, an alginate cryogel based biosensor was developed to detect glucose. The cryogel was prepared using alginate cross-linked by calcium chloride under sub-zero temperature. This porous structure was growth in a 100 μL micropipette tip with a glucose oxidase enzyme entrapped inside the cryogel. The glucose detection was based on the colour change of redox indicator, potassium permanganate, by the hydrogen peroxide resulted from the conversion of glucose. The result showed a porous structure of alginate cryogel with pores diameter of 20-50 μm. The developed glucose biosensor was showed a linear response in the glucose detection from 1.0 to 5.0 mM with a regression of y = 0.01x+0.02 and R2 of 0.994. Furthermore, the glucose biosensor was showed a high operational stability up to 10 times of uninterrupted glucose detections.

  17. Antihypertensive drugs and glucose metabolism

    PubMed Central

    Rizos, Christos V; Elisaf, Moses S

    2014-01-01

    Hypertension plays a major role in the development and progression of micro- and macrovascular disease. Moreover, increased blood pressure often coexists with additional cardiovascular risk factors such as insulin resistance. As a result the need for a comprehensive management of hypertensive patients is critical. However, the various antihypertensive drug categories have different effects on glucose metabolism. Indeed, angiotensin receptor blockers as well as angiotensin converting enzyme inhibitors have been associated with beneficial effects on glucose homeostasis. Calcium channel blockers (CCBs) have an overall neutral effect on glucose metabolism. However, some members of the CCBs class such as azelnidipine and manidipine have been shown to have advantageous effects on glucose homeostasis. On the other hand, diuretics and β-blockers have an overall disadvantageous effect on glucose metabolism. Of note, carvedilol as well as nebivolol seem to differentiate themselves from the rest of the β-blockers class, being more attractive options regarding their effect on glucose homeostasis. The adverse effects of some blood pressure lowering drugs on glucose metabolism may, to an extent, compromise their cardiovascular protective role. As a result the effects on glucose homeostasis of the various blood pressure lowering drugs should be taken into account when selecting an antihypertensive treatment, especially in patients which are at high risk for developing diabetes. PMID:25068013

  18. Blood glucose determination in normal and alloxan-diabetic rats after administration of local anesthetics containing vasoconstrictors.

    PubMed

    Esmerino, L A; Ranali, J; Rodrigues, A L

    1998-01-01

    Normal and alloxan-diabetic rats were injected submucously in the posterior region of the upper jaw with bupivacaine (1.28 mg/kg) containing adrenaline (0.0012 mg/kg), or lignocaine (5.14 mg/kg) containing noradrenaline (0.005 mg/kg). Blood glucose was determined at zero (before administration), 0.5, 1, 2, 3 and 4 hours after the administration of the anesthetics. Statistical analysis (ANOVA and Tukey's test, P < 0.05) showed significant differences between treatments at 1 hour in normal rats. Bupivacaine with adrenaline induced a significantly greater blood glucose level than lignocaine with noradrenaline. The effect was significant but of short duration. In alloxan-diabetic rats, anesthetics containing adrenaline or noradrenaline did not induce increased blood glucose levels.

  19. The glucose-6-phosphatase system.

    PubMed Central

    van Schaftingen, Emile; Gerin, Isabelle

    2002-01-01

    Glucose-6-phosphatase (G6Pase), an enzyme found mainly in the liver and the kidneys, plays the important role of providing glucose during starvation. Unlike most phosphatases acting on water-soluble compounds, it is a membrane-bound enzyme, being associated with the endoplasmic reticulum. In 1975, W. Arion and co-workers proposed a model according to which G6Pase was thought to be a rather unspecific phosphatase, with its catalytic site oriented towards the lumen of the endoplasmic reticulum [Arion, Wallin, Lange and Ballas (1975) Mol. Cell. Biochem. 6, 75--83]. Substrate would be provided to this enzyme by a translocase that is specific for glucose 6-phosphate, thereby accounting for the specificity of the phosphatase for glucose 6-phosphate in intact microsomes. Distinct transporters would allow inorganic phosphate and glucose to leave the vesicles. At variance with this substrate-transport model, other models propose that conformational changes play an important role in the properties of G6Pase. The last 10 years have witnessed important progress in our knowledge of the glucose 6-phosphate hydrolysis system. The genes encoding G6Pase and the glucose 6-phosphate translocase have been cloned and shown to be mutated in glycogen storage disease type Ia and type Ib respectively. The gene encoding a G6Pase-related protein, expressed specifically in pancreatic islets, has also been cloned. Specific potent inhibitors of G6Pase and of the glucose 6-phosphate translocase have been synthesized or isolated from micro-organisms. These as well as other findings support the model initially proposed by Arion. Much progress has also been made with regard to the regulation of the expression of G6Pase by insulin, glucocorticoids, cAMP and glucose. PMID:11879177

  20. Conversion of glucose to sorbose

    DOEpatents

    Davis, Mark E.; Gounder, Rajamani

    2016-02-09

    The present invention is directed to methods for preparing sorbose from glucose, said method comprising: (a) contacting the glucose with a silica-containing structure comprising a zeolite having a topology of a 12 membered-ring or larger, an ordered mesoporous silica material, or an amorphous silica, said structure containing Lewis acidic Ti.sup.4+ or Zr.sup.4+ or both Ti.sup.4+ and Zr.sup.4+ framework centers, said contacting conducted under reaction conditions sufficient to isomerize the glucose to sorbose. The sorbose may be (b) separated or isolated; or (c) converted to ascorbic acid.

  1. Glucose-responsive hydrogel electrode for biocompatible glucose transistor.

    PubMed

    Kajisa, Taira; Sakata, Toshiya

    2017-01-01

    In this paper, we propose a highly sensitive and biocompatible glucose sensor using a semiconductor-based field effect transistor (FET) with a functionalized hydrogel. The principle of the FET device contributes to the easy detection of ionic charges with high sensitivity, and the hydrogel coated on the electrode enables the specific detection of glucose with biocompatibility. The copolymerized hydrogel on the Au gate electrode of the FET device is optimized by controlling the mixture ratio of biocompatible 2-hydroxyethylmethacrylate (HEMA) as the main monomer and vinylphenylboronic acid (VPBA) as a glucose-responsive monomer. The gate surface potential of the hydrogel FETs shifts in the negative direction with increasing glucose concentration from 10 μM to 40 mM, which results from the increase in the negative charges on the basis of the diol-binding of PBA derivatives with glucose molecules in the hydrogel. Moreover, the hydrogel coated on the gate suppresses the signal noise caused by the nonspecific adsorption of proteins such as albumin. The hydrogel FET can serve as a highly sensitive and biocompatible glucose sensor in in vivo or ex vivo applications such as eye contact lenses and sheets adhering to the skin.

  2. Glucose-responsive hydrogel electrode for biocompatible glucose transistor

    PubMed Central

    Kajisa, Taira; Sakata, Toshiya

    2017-01-01

    Abstract In this paper, we propose a highly sensitive and biocompatible glucose sensor using a semiconductor-based field effect transistor (FET) with a functionalized hydrogel. The principle of the FET device contributes to the easy detection of ionic charges with high sensitivity, and the hydrogel coated on the electrode enables the specific detection of glucose with biocompatibility. The copolymerized hydrogel on the Au gate electrode of the FET device is optimized by controlling the mixture ratio of biocompatible 2-hydroxyethylmethacrylate (HEMA) as the main monomer and vinylphenylboronic acid (VPBA) as a glucose-responsive monomer. The gate surface potential of the hydrogel FETs shifts in the negative direction with increasing glucose concentration from 10 μM to 40 mM, which results from the increase in the negative charges on the basis of the diol-binding of PBA derivatives with glucose molecules in the hydrogel. Moreover, the hydrogel coated on the gate suppresses the signal noise caused by the nonspecific adsorption of proteins such as albumin. The hydrogel FET can serve as a highly sensitive and biocompatible glucose sensor in in vivo or ex vivo applications such as eye contact lenses and sheets adhering to the skin. PMID:28179956

  3. Glucose metabolism, insulin sensitivity and β-cell function in type A insulin resistance syndrome around puberty: a 9-year follow-up.

    PubMed

    Huang, Z; Liu, J; Ma, L; Wan, X; He, X; Fang, D; Liao, Z; Li, Y

    2014-01-01

    Diabetes mellitus is thought to be progressive. Insufficient insulin secretion in compensation for insulin resistance leads to glucose intolerance. A previously reported proband with type A insulin resistance syndrome and her younger twin brothers with and without the R1174W missense mutation in the insulin receptor gene were followed for 9 years to study the progression of glucose metabolism, insulin sensitivity, and β-cell function around puberty. Five-hour OGTT was performed in them at each visit. Areas under the curves of glucose, insulin and C-peptides, insulinogenic index, AIR, and Homa indices were assessed. Intramyocellular lipids (IMCLs) were quantified in the proband and compared to those of 12 nondiabetic subjects, 118 newly diagnosed type 2 diabetic patients. The proband maintained normal HbA1c (27-37 mmol/mol) and fasting plasma glucose (3.7-4.5 mmol/l), and her glucose tolerance ameliorated over years. The proband's Homa-IR decreased into adulthood, while her Homa-B, insulinogenic index, AIR, AUCs of insulin, and C-peptide decreased accordingly. Homa-B to Homa-IR ratios stayed significantly higher than normal. Homa-B, AUCs of insulin, and C-peptide of the twin brothers increased in response to the increment of Homa-IR as they entered middle and late puberty. The changes were more dramatic in the twin brothers carrying the mutation. IMCLs of the proband were lower than those of the nondiabetic counterparts and were disproportional for the degree of insulin resistance. Our longitudinal data of type A insulin resistance syndrome around puberty provide significant information for the study of insulin secretion in compensation for insulin resistance.

  4. [Contribution of the kidney to glucose homeostasis].

    PubMed

    Segura, Julián; Ruilope, Luis Miguel

    2013-09-01

    The kidney is involved in glucose homeostasis through three major mechanisms: renal gluconeogenesis, renal glucose consumption, and glucose reabsorption in the proximal tubule. Glucose reabsorption is one of the most important physiological functions of the kidney, allowing full recovery of filtered glucose, elimination of glucose from the urine, and prevention of calorie loss. Approximately 90% of the glucose is reabsorbed in the S1 segment of the proximal tubule, where glucose transporter-2 (GLUT2) and sodium-glucose transporter-2 (SGLT2) are located, while the remaining 10% is reabsorbed in the S3 segment by SGLT1 and GLUT1 transporters. In patients with hyperglycemia, the kidney continues to reabsorb glucose, thus maintaining hyperglycemia. Most of the renal glucose reabsorption is mediated by SGLT2. Several experimental and clinical studies suggest that pharmacological blockade of this transporter might be beneficial in the management of hyperglycemia in patients with type 2 diabetes.

  5. Orienteering performance and ingestion of glucose and glucose polymers.

    PubMed

    Kujala, U M; Heinonen, O J; Kvist, M; Kärkkäinen, O P; Marniemi, J; Niittymäki, K; Havas, E

    1989-06-01

    The benefit of glucose polymer ingestion in addition to 2.5 per cent glucose before and during a prolonged orienteering competition was studied. The final time in the competition in the group ingesting 2.5 per cent glucose (group G, n = 10) was 113 min 37 s +/- 8 min 11 s, and in the group which had additionally ingested glucose polymer (group G + GP, n = 8) 107 min 18s +/- 4 min 41 s (NS). One fifth (21 per cent) of the time difference between the two groups was due to difference in orienteering errors. Group G + GP orienteered the last third of the competition faster than group G (p less than 0.05). The time ratio between the last third of the competition and the first third of the competition was lower in group G + GP than in group G (p less than 0.05). After the competition, there was statistically insignificant tendency to higher serum glucose and lower serum free fatty acid concentrations in group G + GP, and serum insulin concentration was higher in group G + GP than in group G (p less than 0.05). Three subjects reported that they exhausted during the competition. These same three subjects had the lowest serum glucose concentrations after the competition (2.9 mmol.1(-1), 2.9 mmol.1(-1), 3.5 mmol.1(-1] and all of them were from group G. It is concluded that glucose polymer syrup ingestion is beneficial for prolonged psychophysical performance.

  6. Meal related glucose monitoring is a method of diagnosing glucose intolerance in pregnancies with high probability of gestational diabetes but normal glucose tolerance by oral glucose tolerance test.

    PubMed

    John, Mathew; Gopinath, Deepa

    2013-06-01

    Gestational diabetes mellitus diagnosed by classical oral glucose tolerance test can result in fetal complications like macrosomia and polyhydramnios. Guidelines exist on management of patients diagnose by abnormal oral glucose tolerance test with diet modification followed by insulin. Even patients with abnormal oral glucose tolerance test maintaining apparently normal blood sugars with diet are advised insulin if there is accelerated fetal growth. But patients with normal oral glucose tolerance test can present with macrosomia and polyhydramnios. These patients are labelled as not having gestational diabetes mellitus and are followed up with repeat oral glucose tolerance test. We hypothesise that these patients may have an altered placental threshold to glucose or abnormal sensitivity of fetal tissues to glucose. Meal related glucose monitoring in these patients can identify minor abnormalities in glucose disturbance and should be treated to targets similar to physiological levels of glucose in non pregnant adults.

  7. Glucose metabolism and cardiac hypertrophy

    PubMed Central

    Kolwicz, Stephen C.; Tian, Rong

    2011-01-01

    The most notable change in the metabolic profile of hypertrophied hearts is an increased reliance on glucose with an overall reduced oxidative metabolism, i.e. a reappearance of the foetal metabolic pattern. In animal models, this change is attributed to the down-regulation of the transcriptional cascades promoting gene expression for fatty acid oxidation and mitochondrial oxidative phosphorylation in adult hearts. Impaired myocardial energetics in cardiac hypertrophy also triggers AMP-activated protein kinase (AMPK), leading to increased glucose uptake and glycolysis. Aside from increased reliance on glucose as an energy source, changes in other glucose metabolism pathways, e.g. the pentose phosphate pathway, the glucosamine biosynthesis pathway, and anaplerosis, are also noted in the hypertrophied hearts. Studies using transgenic mouse models and pharmacological compounds to mimic or counter the switch of substrate preference in cardiac hypertrophy have demonstrated that increased glucose metabolism in adult heart is not harmful and can be beneficial when it provides sufficient fuel for oxidative metabolism. However, improvement in the oxidative capacity and efficiency rather than the selection of the substrate is likely the ultimate goal for metabolic therapies. PMID:21502371

  8. Ketones suppress brain glucose consumption.

    PubMed

    LaManna, Joseph C; Salem, Nicolas; Puchowicz, Michelle; Erokwu, Bernadette; Koppaka, Smruta; Flask, Chris; Lee, Zhenghong

    2009-01-01

    The brain is dependent on glucose as a primary energy substrate, but is capable of utilizing ketones such as beta-hydroxybutyrate (beta HB) and acetoacetate (AcAc), as occurs with fasting, prolonged starvation or chronic feeding of a high fat/low carbohydrate diet (ketogenic diet). In this study, the local cerebral metabolic rate of glucose consumption (CMRglu; microM/min/100g) was calculated in the cortex and cerebellum of control and ketotic rats using Patlak analysis. Rats were imaged on a rodent PET scanner and MRI was performed on a 7-Tesla Bruker scanner for registration with the PET images. Plasma glucose and beta HB concentrations were measured and 90-minute dynamic PET scans were started simultaneously with bolus injection of 2-Deoxy-2[18F]Fluoro-D-Glucose (FDG). The blood radioactivity concentration was automatically sampled from the tail vein for 3 min following injection and manual periodic blood samples were taken. The calculated local CMRGlu decreased with increasing plasma BHB concentration in the cerebellum (CMRGlu = -4.07*[BHB] + 61.4, r2 = 0.3) and in the frontal cortex (CMRGlu = -3.93*[BHB] + 42.7, r2 = 0.5). These data indicate that, under conditions of ketosis, glucose consumption is decreased in the cortex and cerebellum by about 10% per each mM of plasma ketone bodies.

  9. Glucose oxidation positively regulates glucose uptake and improves cardiac function recovery after myocardial reperfusion.

    PubMed

    Li, Tingting; Xu, Jie; Qin, Xinghua; Hou, Zuoxu; Guo, Yongzheng; Liu, Zhenhua; Wu, Jianjiang; Zheng, Hong; Zhang, Xing; Gao, Feng

    2017-03-21

    Myocardial reperfusion decreases glucose oxidation and uncouples glucose oxidation from glycolysis. Therapies that increase glucose oxidation lessen myocardial ischemia/reperfusion injury. However, the regulation of glucose uptake during reperfusion remains poorly understood. Here we found that glucose uptake was remarkably diminished in myocardium following reperfusion in Sprague-Dawley rats as detected by 18F-labeled and fluorescent-labeled glucose analogs, even though GLUT1 was upregulated by 3 folds and GLUT4 translocation remained unchanged compared with those of sham rats. The decreased glucose uptake was accompanied by suppressed glucose oxidation. Interestingly, stimulating glucose oxidation by inhibition of pyruvate dehydrogenase kinase 4 (PDK4), a rate-limiting enzyme for glucose oxidation, increased glucose uptake and alleviated ischemia/reperfusion injury. In vitro data in neonatal myocytes showed that PDK4 overexpression decreased glucose uptake, while its knockdown increased glucose uptake, suggesting a role of PDK4 in regulating glucose uptake. Moreover, inhibition of PDK4 increased myocardial glucose uptake with concomitant enhancement of cardiac insulin sensitivity following myocardial ischemia/reperfusion. These results showed that the suppressed glucose oxidation mediated by PDK4 contributes to the reduced glucose uptake in myocardium following reperfusion, and enhancement of glucose uptake exerts cardioprotection. The findings suggest that stimulating glucose oxidation via PDK4 could be an efficient approach to improve recovery from myocardial ischemia/reperfusion injury.

  10. Glucose, glycolysis and lymphocyte responses.

    PubMed

    Donnelly, Raymond P; Finlay, David K

    2015-12-01

    Activated lymphocytes engage in robust growth and rapid proliferation. To achieve this, they tend to adopt a form of glucose metabolism termed aerobic glycolysis. This type of metabolism allows for the use of large amounts of glucose to generate energy, but also to support biosynthetic processes. This review article will discuss how aerobic glycolysis supports the biosynthetic demands of activated T cells, B cells and Natural Killer cells, and the emerging concept that glycolysis is integrally linked to the differentiation and function of these lymphocyte populations.

  11. The Acute and Residual Effect of a Single Exercise Session on Meal Glucose Tolerance in Sedentary Young Adults

    PubMed Central

    Short, Kevin R.; Pratt, Lauren V.; Teague, April M.

    2012-01-01

    The study goals were to (1) establish the variability in postprandial glucose control in healthy young people consuming a mixed meal and, then (2) determine the acute and residual impact of a single exercise bout on postprandial glucose control. In study 1, 18 people completed two similar mixed meal trials and an intravenous glucose tolerance test (IVGTT). There were strong test-retest correlations for the post-meal area under the curve (AUC) for glucose, insulin, and Cpeptide (r = 0.73–0.83) and the Matsuda insulin sensitivity index (ISI, r = 0.76), and between meal and IVGTT-derived ISI (r = 0.83). In study 2, 11 untrained young adults completed 3 trials. One trial (No Ex) was completed after refraining from vigorous activity for ≥3 days. On the other 2 trials, a 45-min aerobic exercise bout was performed either 17-hours (Prior Day Ex) or 1-hour (Same Day Ex) before consuming the test meal. Compared to No Ex and Prior Day Ex, which did not differ from one another, there were lower AUCs on the Same Day Ex trial for glucose (6%), insulin (20%) and C-peptide (14%). Thus, a single moderate intensity exercise session can acutely improve glycemic control but the effect is modest and short-lived. PMID:22666560

  12. Hepatocytes: critical for glucose homeostasis.

    PubMed

    Klover, Peter J; Mooney, Robert A

    2004-05-01

    Maintaining blood glucose levels within a narrow range is a critical physiological function requiring multiple metabolic pathways and involving several cell types, including a prominent role for hepatocytes. Under hormonal control, hepatocytes can respond to either feeding or fasting conditions by storing or producing glucose as necessary. In the fasting state, the effects of glucagon avoid hypoglycemia by stimulating glucogenesis and glycogenolysis and initiating hepatic glucose release. Postprandially, insulin prevents hyperglycemia, in part, by suppressing hepatic gluconeogenesis and glycogenolysis and facilitating hepatic glycogen synthesis. Both transcriptional regulation of rate limiting enzymes and modulation of enzyme activity through phosphorylation and allosteric regulation are involved. Type 2 diabetes mellitus is the most common serious metabolic condition in the world, and results from a subnormal response of tissues to insulin (insulin resistance) and a failure of the insulin-secreting beta cells to compensate. In type 2 diabetes, glucose is overproduced by the hepatocyte and is ineffectively metabolized by other organs. Impairments in the insulin signal transduction pathway appear to be critical lesions contributing to insulin resistance and type 2 diabetes.

  13. Glucose-6-Phosphate Dehydrogenase Revisited

    PubMed Central

    O'Connell, Jerome T.; Henderson, Alfred R.

    1984-01-01

    Hemolytic diseases associated with drugs have been recognized since antiquity. Many of these anemias have been associated with oxidizing agents and deficiencies in the intraerythrocytic enzyme glucose-6-phosphate dehydrogenase. This paper outlines the discovery, prevalence, and variants of this enzyme. Methods of diagnosis of associated anemias are offered. PMID:6502728

  14. Modeling the glucose sensor error.

    PubMed

    Facchinetti, Andrea; Del Favero, Simone; Sparacino, Giovanni; Castle, Jessica R; Ward, W Kenneth; Cobelli, Claudio

    2014-03-01

    Continuous glucose monitoring (CGM) sensors are portable devices, employed in the treatment of diabetes, able to measure glucose concentration in the interstitium almost continuously for several days. However, CGM sensors are not as accurate as standard blood glucose (BG) meters. Studies comparing CGM versus BG demonstrated that CGM is affected by distortion due to diffusion processes and by time-varying systematic under/overestimations due to calibrations and sensor drifts. In addition, measurement noise is also present in CGM data. A reliable model of the different components of CGM inaccuracy with respect to BG (briefly, "sensor error") is important in several applications, e.g., design of optimal digital filters for denoising of CGM data, real-time glucose prediction, insulin dosing, and artificial pancreas control algorithms. The aim of this paper is to propose an approach to describe CGM sensor error by exploiting n multiple simultaneous CGM recordings. The model of sensor error description includes a model of blood-to-interstitial glucose diffusion process, a linear time-varying model to account for calibration and sensor drift-in-time, and an autoregressive model to describe the additive measurement noise. Model orders and parameters are identified from the n simultaneous CGM sensor recordings and BG references. While the model is applicable to any CGM sensor, here, it is used on a database of 36 datasets of type 1 diabetic adults in which n = 4 Dexcom SEVEN Plus CGM time series and frequent BG references were available simultaneously. Results demonstrates that multiple simultaneous sensor data and proper modeling allow dissecting the sensor error into its different components, distinguishing those related to physiology from those related to technology.

  15. Genetics Home Reference: glucose phosphate isomerase deficiency

    MedlinePlus

    ... Understand Genetics Home Health Conditions GPI deficiency glucose phosphate isomerase deficiency Enable Javascript to view the expand/ ... Download PDF Open All Close All Description Glucose phosphate isomerase (GPI) deficiency is an inherited disorder that ...

  16. Genetics Home Reference: glucose-galactose malabsorption

    MedlinePlus

    ... the sugars glucose and galactose, which prevents proper digestion of these molecules and larger molecules made from ... are broken down into these simple sugars during digestion. Sucrose is broken down into glucose and another ...

  17. Glucose sensing by means of silicon photonics

    NASA Astrophysics Data System (ADS)

    Bockstaele, Ronny; Ryckeboer, Eva; Hattasan, Nannicha; De Koninck, Yannick; Muneeb, Muhammad; Verstuyft, Steven; Delbeke, Danaë; Bogaerts, Wim; Roelkens, Gunther; Baets, Roel

    2014-03-01

    Diabetes is a fast growing metabolic disease, where the patients suffer from disordered glucose blood levels. Monitoring the blood glucose values in combination with extra insulin injection is currently the only therapy to keep the glucose concentration in diabetic patients under control, minimizing the long-term effects of elevated glucose concentrations and improving quality of life of the diabetic patients. Implantable sensors allow continuous glucose monitoring, offering the most reliable data to control the glucose levels. Infrared absorption spectrometers offer a non-chemical measurement method to determine the small glucose concentrations in blood serum. In this work, a spectrometer platform based on silicon photonics is presented, allowing the realization of very small glucose sensors suitable for building implantable sensors. A proof-of-concept of a spectrometer with integrated evanescent sample interface is presented, and the route towards a fully implantable spectrometer is discussed.

  18. Glucose Transport Machinery Reconstituted in Cell Models

    PubMed Central

    Hansen, Jesper S.; Elbing, Karin; Thompson, James R.; Malmstadt, Noah

    2015-01-01

    Here we demonstrate the production of a functioning cell model by formation of giant vesicles reconstituted with the GLUT1 glucose transporter and a glucose oxidase and hydrogen peroxidase linked fluorescent reporter internally. Hence, a simplified artificial cell is formed that is able to take up glucose and process it. PMID:25562394

  19. Glucose transport machinery reconstituted in cell models.

    PubMed

    Hansen, Jesper S; Elbing, Karin; Thompson, James R; Malmstadt, Noah; Lindkvist-Petersson, Karin

    2015-02-11

    Here we demonstrate the production of a functioning cell model by formation of giant vesicles reconstituted with the GLUT1 glucose transporter and a glucose oxidase and hydrogen peroxidase linked fluorescent reporter internally. Hence, a simplified artificial cell is formed that is able to take up glucose and process it.

  20. Blood Glucose Levels and Problem Behavior

    ERIC Educational Resources Information Center

    Valdovinos, Maria G.; Weyand, David

    2006-01-01

    The relationship between varying blood glucose levels and problem behavior during daily scheduled activities was examined. The effects that varying blood glucose levels had on problem behavior during daily scheduled activities were examined. Prior research has shown that differing blood glucose levels can affect behavior and mood. Results of this…

  1. Modeling of relationship between glucose concentration in blood and glucose concentration in interstitial fluid

    NASA Astrophysics Data System (ADS)

    Shi, Ting; Li, Dachao; Ji, Yongjie; Li, Guoqing; Xu, Kexin

    2012-03-01

    In recent years, using the detection of interstitial fluid glucose concentration to realize the real-time continuous monitoring of blood glucose concentration gets more and more attention, because for one person, the relationship between blood glucose concentration and interstitial fluid glucose concentration satisfies specific rules. However, the glucose concentration in interstitial fluid is not entirely equal to the glucose concentration in blood and has a physiological lag because of the physiological difference of cells in blood and interstitial fluid. Because the clinical diagnostic criteria of diabetes are still blood glucose concentration, the evaluation model of the physiological lag parameter between the glucose concentration in blood and the glucose concentration in interstitial fluid should be established. The physiological difference in glucose molecules uptake, utilization, and elimination by cells in blood and interstitial fluid and the diffusion velocity of glucose molecule from blood to interstitial fluid will be induced to the mass transfer model to express the physiological lag parameter. Based on the continuous monitoring of glucose concentration in interstitial fluid, the project had studied the mass transfer model to establish the evaluation model of the physiological lag parameter between the glucose concentration in blood and the glucose concentration in interstitial fluid. We have preliminary achieved to evaluate the physiological lag parameter exactly and predict the glucose concentration in blood through the glucose concentration in interstitial fluid accurately.

  2. Dexamethasone increases glucose cycling, but not glucose production, in healthy subjects

    SciTech Connect

    Wajngot, A.; Khan, A.; Giacca, A.; Vranic, M.; Efendic, S. )

    1990-11-01

    We established that measurement of glucose fluxes through glucose-6-phosphatase (G-6-Pase; hepatic total glucose output, HTGO), glucose cycling (GC), and glucose production (HGP), reveals early diabetogenic changes in liver metabolism. To elucidate the mechanism of the diabetogenic effect of glucocorticoids, we treated eight healthy subjects with oral dexamethasone (DEX; 15 mg over 48 h) and measured HTGO with (2-3H)glucose and HGP with (6-3H)glucose postabsorptively and during a 2-h glucose infusion (11.1 mumol.kg-1.min-1). (2-3H)- minus (6-3H)glucose equals GC. DEX significantly increased plasma glucose, insulin, C peptide, and HTGO, while HGP was unchanged. In controls and DEX, glucose infusion suppressed HTGO (82 vs. 78%) and HGP (87 vs. 91%). DEX increased GC postabsorptively (three-fold) P less than 0.005 and during glucose infusion (P less than 0.05) but decreased metabolic clearance and glucose uptake (Rd), which eventually normalized, however. Because DEX increased HTGO (G-6-Pase) and not HGP (glycogenolysis + gluconeogenesis), we assume that DEX increases HTGO and GC in humans by activating G-6-Pase directly, rather than by expanding the glucose 6-phosphate pool. Hyperglycemia caused by peripheral effects of DEX can also contribute to an increase in GC by activating glucokinase. Therefore, measurement of glucose fluxes through G-6-Pase and GC revealed significant early effects of DEX on hepatic glucose metabolism, which are not yet reflected in HGP.

  3. Non-invasive glucose monitor

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2001-01-01

    A non-invasive method for determining blood level of an analyte of interest, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed.

  4. Reimbursement for Continuous Glucose Monitoring

    PubMed Central

    DeVries, J. Hans

    2016-01-01

    Abstract Continuous glucose monitoring (CGM) systems have been available for more than 15 years by now. However, market uptake is relatively low in most countries; in other words, relatively few patients with diabetes use CGM systems regularly. One major reason for the reluctance of patients to use CGM systems is the costs associated (i.e., in most countries no reimbursement is provided by the health insurance companies). In case reimbursement is in place, like in the United States, only certain patient groups get reimbursement that fulfills strict indications. This situation is somewhat surprising in view of the mounting evidence for benefits of CGM usage from clinical trials: most meta-analyses of these trials consistently show a clinically relevant improvement of glucose control associated with a reduction in hypoglycemic events. More recent trials with CGM systems with an improved CGM technology showed even more impressive benefits, especially if CGM systems are used in different combinations with an insulin pump (e.g., with automated bolus calculators and low glucose suspend features). Nevertheless, sufficient evidence is not available for all patient groups, and more data on cost–efficacy are needed. In addition, good data from real-world studies/registers documenting the benefits of CGM usage under daily life conditions would be of help to convince healthcare systems to cover the costs of CGM systems. In view of the ongoing improvements in established needle-type CGM systems, the fact that new CGM technology will come to the market soon (e.g., implantable sensors), that CGM-like systems are quite successfully at least in certain markets (like the flash glucose monitoring systems), and that the first artificial pancreas systems will come to the market in the next few years, there is a need to make sure that this major improvement in diabetes therapy becomes more widely available for patients with diabetes, for which better reimbursement is essential. PMID

  5. Oxidative metabolism: glucose versus ketones.

    PubMed

    Prince, Allison; Zhang, Yifan; Croniger, Colleen; Puchowicz, Michelle

    2013-01-01

    The coupling of upstream oxidative processes (glycolysis, beta-oxidation, CAC turnover) to mitochondrial oxidative phosphorylation (OXPHOS) under the driving conditions of energy demand by the cell results in the liberation of free energy as ATP. Perturbations in glycolytic CAC or OXPHOS can result in pathology or cell death. To better understand whole body energy expenditure during chronic ketosis, we used a diet-induced rat model of ketosis to determine if high-fat-carbohydrate-restricted "ketogenic" diet results in changes in total energy expenditure (TEE). Consistent with previous reports of increased energy expenditure in mice, we hypothesized that rats fed ketogenic diet for 3 weeks would result in increased resting energy expenditure due to alterations in metabolism associated with a "switch" in energy substrate from glucose to ketone bodies. The rationale is ketone bodies are a more efficient fuel than glucose. Indirect calorimetric analysis revealed a moderate increase in VO2 and decreased VCO2 and heat with ketosis. These results suggest ketosis induces a moderate uncoupling state and less oxidative efficiency compared to glucose oxidation.

  6. Non-Invasive Glucose Measurement

    NASA Astrophysics Data System (ADS)

    Blakley, Daniel

    2010-10-01

    There are two little words, when taken together have great implications: ``What IF'' In the US alone, there are millions who are burdened with diabetes and who must maintain their glucose levels by taking blood samples and having it analyzed. Even though this procedure has improved over time, still it is very intrusive and is a burden to many that must live with it. What if it were not necessary? Although it is current practice to measure glucose levels invasively (using blood samples), it may be possible to measure glucose non-invasively. Although several companies around the world have invested millions of dollars to address this problem, none have been successful thus far. However, there are many methods that hold a potential and many approaches that have not yet been explored. We are working on a review of what has been approached thus far and are entertaining proposals for a combined interdisciplinary approach which combines expertise from bioengineering, physics, and biology. We hope to learn from the unsuccessful attempts of others whilst employing innovative new approaches to this problem.

  7. Effect of amiloride, or amiloride plus hydrochlorothiazide, versus hydrochlorothiazide on glucose tolerance and blood pressure (PATHWAY-3): a parallel-group, double-blind randomised phase 4 trial

    PubMed Central

    Brown, Morris J; Williams, Bryan; Morant, Steve V; Webb, David J; Caulfield, Mark J; Cruickshank, J Kennedy; Ford, Ian; McInnes, Gordon; Sever, Peter; Salsbury, Jackie; Mackenzie, Isla S; Padmanabhan, Sandosh; MacDonald, Thomas M

    2016-01-01

    Summary Background Potassium depletion by thiazide diuretics is associated with a rise in blood glucose. We assessed whether addition or substitution of a potassium-sparing diuretic, amiloride, to treatment with a thiazide can prevent glucose intolerance and improve blood pressure control. Methods We did a parallel-group, randomised, double-blind trial in 11 secondary and two primary care sites in the UK. Eligible patients were aged 18–80 years; had clinic systolic blood pressure of 140 mm Hg or higher and home systolic blood pressure of 130 mmHg or higher on permitted background drugs of angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, β blockers, calcium-channel blockers, or direct renin inhibitors (previously untreated patients were also eligible in specific circumstances); and had at least one component of the metabolic syndrome in addition to hypertension. Patients with known diabetes were excluded. Patients were randomly assigned (1:1:1) to 24 weeks of daily oral treatment with starting doses of 10 mg amiloride, 25 mg hydrochlorothiazide, or 5 mg amiloride plus 12·5 mg hydrochlorothiazide; all doses were doubled after 12 weeks. Random assignment was done via a central computer system. Both participants and investigators were masked to assignment. Our hierarchical primary endpoints, assessed on a modified intention-to-treat basis at 12 and 24 weeks, were the differences from baseline in blood glucose measured 2 h after a 75 g oral glucose tolerance test (OGTT), compared first between the hydrochlorothiazide and amiloride groups, and then between the hydrochlorothiazide and combination groups. A key secondary endpoint was change in home systolic blood pressure at 12 and 24 weeks. This trial is registered with ClinicalTrials.gov, number NCT00797862, and the MHRA, Eudract number 2009-010068-41, and is now complete. Findings Between Nov 18, 2009, and Dec 15, 2014, 145 patients were randomly assigned to amiloride, 146 to

  8. Differential associations of oral glucose tolerance test-derived measures of insulin sensitivity and pancreatic β-cell function with coronary artery calcification and microalbuminuria in type 2 diabetes.

    PubMed

    Mulvey, Claire K; McNeill, Ann M; Girman, Cynthia J; Churchill, Timothy W; Terembula, Karen; Ferguson, Jane F; Shah, Rachana; Mehta, Nehal N; Qasim, Atif N; Rickels, Michael R; Reilly, Muredach P

    2014-01-01

    OBJECTIVE We evaluated relationships of oral glucose tolerance testing (OGTT)-derived measures of insulin sensitivity and pancreatic β-cell function with indices of diabetes complications in a cross-sectional study of patients with type 2 diabetes who are free of overt cardiovascular or renal disease. RESEARCH DESIGN AND METHODS A subset of participants from the Penn Diabetes Heart Study (n = 672; mean age 59 ± 8 years; 67% male; 60% Caucasian) underwent a standard 2-h, 75-g OGTT. Insulin sensitivity was estimated using the Matsuda Insulin Sensitivity Index (ISI), and β-cell function was estimated using the Insulinogenic Index. Multivariable modeling was used to analyze associations between quartiles of each index with coronary artery calcification (CAC) and microalbuminuria. RESULTS The Insulinogenic Index and Matsuda ISI had distinct associations with cardiometabolic risk factors. The top quartile of the Matsuda ISI had a negative association with CAC that remained significant after adjusting for traditional cardiovascular risk factors (Tobit ratio -0.78 [95% CI -1.51 to -0.05]; P = 0.035), but the Insulinogenic Index was not associated with CAC. Conversely, the highest quartile of the Insulinogenic Index, but not the Matsuda ISI, was associated with lower odds of microalbuminuria (OR 0.52 [95% CI 0.30-0.91]; P = 0.022); however, this association was attenuated in models that included duration of diabetes. CONCLUSIONS Lower β-cell function is associated with microalbuminuria, a microvascular complication, while impaired insulin sensitivity is associated with higher CAC, a predictor of macrovascular complications. Despite these pathophysiological insights, the Matsuda ISI and Insulinogenic Index are unlikely to be translated into clinical use in type 2 diabetes beyond established clinical variables, such as obesity or duration of diabetes.

  9. Clinical features and natural course of acromegaly in patients with discordance in the nadir GH level on the oral glucose test and the IGF-1 value at 3 months after adenomectomy.

    PubMed

    Kinoshita, Yasuyuki; Tominaga, Atsushi; Usui, Satoshi; Arita, Kazunori; Sakoguchi, Tetsuhiko; Sugiyama, Kazuhiko; Kurisu, Kaoru

    2016-04-01

    Discordant GH and IGF-1 levels after adenomectomy are well recognized in acromegalics. The aim of this study was to evaluate the clinical features and natural course of postoperative acromegaly associated with discordant GH and IGF-1 levels over a postoperative period. A total of 69 acromegalics underwent surgery with at least 1 year of follow-up and received 75-g oral glucose tolerance tests (OGTTs) at 3 months postoperatively. The patients were categorized into four groups according to the postoperative nadir GH levels and IGF-1 levels: controlled group (normal GH and normal IGF-1), high-IGF-1 group (normal GH and high IGF-1), high-GH group (high GH and normal IGF-1), and uncontrolled group (high GH and high IGF-1). The incidence of discordant GH and IGF-1 levels was 27.5%: high-IGF-1 group = 10.1% (n = 7) and high-GH group = 17.4% (n = 12). All patients in the high-IGF-1 group exhibited a decline in the IGF-1 level after surgery, with normalization observed in 71.4% of the patients without additional treatment (median 23 months). These subjects had preoperatively high IGF-1 levels despite not demonstrating higher GH levels than the patients in the controlled group. On the other hand, four patients in the high-GH group exhibited an elevated nadir GH level higher than 1.0 μg/L on repeated OGTTs after 3 months, and one patient experienced a recurrence of acromegaly. Patients in the high-IGF-1 group require no additional treatments, and their IGF-1 levels are likely to normalize within a few years. However, patients in the high-GH group should be carefully followed due to the possibility of recurrence.

  10. Correspondence of continuous interstitial glucose measurement against arterialised and capillary glucose following an oral glucose tolerance test in healthy volunteers.

    PubMed

    Dye, Louise; Mansfield, Michael; Lasikiewicz, Nicola; Mahawish, Lena; Schnell, Rainer; Talbot, Duncan; Chauhan, Hitesh; Croden, Fiona; Lawton, Clare

    2010-01-01

    The aim of the present study was to validate the Glucoday continuous interstitial ambulatory glucose-monitoring device (AGD) against plasma glucose measured from arterialised venous (AV) and glucose from capillary whole blood (finger prick, FP) in non-diabetic subjects in response to an oral glucose tolerance test. Fifteen healthy overweight men (age 30-49 years, BMI 26-31 kg/m2) participated. Glucose levels were measured before, during and after consumption of an oral 75 g glucose load using twelve FP samples and forty-four 1 ml AV blood samples during 180 min. Interstitial glucose was measured via the AGD. Three venous samples for fasting insulin were taken to estimate insulin resistance. Profiles of AGD, AV and FP glucose were generated for each participant. Glucose values for each minute of the measurement period were interpolated using a locally weighted scatterplot smoother. Data were compared using Bland-Altman plots that showed good correspondence between all pairs of measurements. Concordance between the three methods was 0.8771 (Kendall's W, n 15, P < 0.001). Concordance was greater between AV and FP (W = 0.9696) than AGD and AV (W = 0.8770) or AGD and FP (W = 0.8764). Analysis of time to peak glucose indicated that AGD measures lagged approximately 15 min behind FP and AV measures. Percent body fat was significantly correlated with time to peak glucose levels for each measure, while BMI and estimated insulin resistance (homeostatic model assessment, HOMA) were not. In conclusion, AGD shows good correspondence with FP and AV glucose measures in response to a glucose load with a 15 min time lag. Taking this into account, AGD has potential application in nutrition and behaviour studies.

  11. A MEMS differential viscometric sensor for affinity glucose detection in continuous glucose monitoring

    NASA Astrophysics Data System (ADS)

    Huang, Xian; Li, Siqi; Davis, Erin; Leduc, Charles; Ravussin, Yann; Cai, Haogang; Song, Bing; Li, Dachao; Accili, Domenico; Leibel, Rudolph; Wang, Qian; Lin, Qiao

    2013-05-01

    Micromachined viscometric affinity glucose sensors have been previously demonstrated using vibrational cantilever and diaphragm. These devices featured a single glucose detection module that determines glucose concentrations through viscosity changes of glucose-sensitive polymer solutions. However, fluctuations in temperature and other environmental parameters might potentially affect the stability and reliability of these devices, creating complexity in their applications in subcutaneously implanted continuous glucose monitoring (CGM). To address these issues, we present a MEMS differential sensor that can effectively reject environmental disturbances while allowing accurate glucose detection. The sensor consists of two magnetically driven vibrating diaphragms situated inside microchambers filled with a boronic-acid based glucose-sensing solution and a reference solution insensitive to glucose. Glucose concentrations can be accurately determined by characteristics of the diaphragm vibration through differential capacitive detection. Our in vitro and preliminary in vivo experimental data demonstrate the potential of this sensor for highly stable subcutaneous CGM applications.

  12. FRET-based glucose monitoring for bioprocessing

    NASA Astrophysics Data System (ADS)

    Bartolome, Amelita; Smalls-Mantey, Lauren; Lin, Debora; Rao, Govind; Tolosa, Leah

    2006-02-01

    The glucose-mediated conformational changes in the glucose binding protein (GBP) have been exploited in the development of fluorescence based glucose sensors. The fluorescence response is generated by a polarity sensitive dye attached to a specific site. Such fluorescent sensors respond to submicromolar glucose at diffusion-controlled rates mimicking the wild type. However, such sensors have been limited to in vitro glucose sensing because of the preliminary dye-labeling step. In the study described here, the dye-labeling step is omitted by genetically encoding the GBP with two green fluorescent mutants namely, the green fluorescent protein (GFP) and the yellow fluorescent protein (YFP) in the N- and C-terminal ends, respectively. These two GFP mutants comprise a fluorescence resonance energy transfer (FRET) donor and acceptor pair. Thus, when glucose binds with GBP, the conformational changes affect the FRET efficiency yielding a dose-dependent response. A potential application for this FRET-based glucose biosensor is online glucose sensing in bioprocessing and cell culture. This was demonstrated by the measurement of glucose consumption in yeast fermentation. Further development of this system should yield in vivo measurement of glucose in bioprocesses.

  13. Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming.

    PubMed

    Choi, Kevin; Weber, Jean-Michel

    2016-03-15

    This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg(-1)·min(-1) and boost glucose disposal to 40.1 ± 13 μmol·kg(-1)·min(-1). These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise.

  14. Central acylated ghrelin improves memory function and hippocampal AMPK activation and partly reverses the impairment of energy and glucose metabolism in rats infused with β-amyloid.

    PubMed

    Kang, Suna; Moon, Na Rang; Kim, Da Sol; Kim, Sung Hoon; Park, Sunmin

    2015-09-01

    Ghrelin is a gastric hormone released during the fasting state that targets the hypothalamus where it induces hunger; however, emerging evidence suggests it may also affect memory function. We examined the effect of central acylated-ghrelin and DES-acetylated ghrelin (native ghrelin) on memory function and glucose metabolism in an experimentally induced Alzheimer's disease (AD) rat model. AD rats were divided into 3 groups and Non-AD rats were used as a normal-control group. Each rat in the AD groups had intracerebroventricular (ICV) infusion of β-amyloid (25-35; 16.8nmol/day) into the lateral ventricle for 3 days, and then the pumps were changed to infuse either acylated-ghrelin (0.2nmol/h; AD-G), DES-acylated ghrelin (0.2nmol/h; AD-DES-G), or saline (control; AD-C) for 3 weeks. The Non-AD group had ICV infusion of β-amyloid (35-25) which does not deposit in the hippocampus. During the next 3 weeks memory function, food intake, body weight gain, body fat composition, and glucose metabolism were measured. AD-C exhibited greater β-amyloid deposition compared to Non-AD-C, and AD-G suppressed the increased β-amyloid deposition and potentiated the phosphorylation AMPK. In addition, AD-G increased the phosphorylation GSK and decreased the phosphorylation of Tau in comparison to AD-C and AD-DES-G. Cognitive function, measured by passive avoidance and water maze tests, was much lower in AD-C than Non-AD-C whereas AD-G but not AD-DES-G prevented the decrease (p<0.021). Body weight gain was lower in AD-C group than Non-AD-C group without changing epididymal fat mass. AD-G reversed the decrease in body weight which was due to increased energy intake and decreased energy expenditure. The AD-G group exhibited a decrease in the second part of serum glucose levels during an oral glucose tolerance test (OGTT) compared to the AD-C and AD-DES-G group (p<0.009). However, area under the curve of insulin during the first part of OGTT was higher in AD-DES-G than other groups

  15. Regulation of Blood Glucose by Hypothalamic Pyruvate Metabolism

    NASA Astrophysics Data System (ADS)

    Lam, Tony K. T.; Gutierrez-Juarez, Roger; Pocai, Alessandro; Rossetti, Luciano

    2005-08-01

    The brain keenly depends on glucose for energy, and mammalians have redundant systems to control glucose production. An increase in circulating glucose inhibits glucose production in the liver, but this negative feedback is impaired in type 2 diabetes. Here we report that a primary increase in hypothalamic glucose levels lowers blood glucose through inhibition of glucose production in rats. The effect of glucose requires its conversion to lactate followed by stimulation of pyruvate metabolism, which leads to activation of adenosine triphosphate (ATP)-sensitive potassium channels. Thus, interventions designed to enhance the hypothalamic sensing of glucose may improve glucose homeostasis in diabetes.

  16. Why control blood glucose levels?

    PubMed

    Rossini, A A

    1976-03-01

    The controversy as to the relationship between the degree of control of diabetes and the progression of the complications of the disease has not been solved. However, in this review, various studies suggesting a relationship between the metabolic abnormality and the diabetic complications are examined. The disadvantages of the uncontrolled diabetes mellitus can be divided into two major categories-short-term and long-term. The short-term disadvantages of controlled diabetes mellitus include the following: (1) ketoacidosis and hyperosmolar coma; (2) intracellular dehydration; (3) electrolyte imbalance; (4) decreased phagocytosis; (5) immunologic and lymphocyte activity; (6) impairment of wound healing; and (7) abnormality of lipids. The long-term disadvantages of uncontrolled diabetes melitus include the following: (1) nephropathy; (2) neuropathy; (3) retinopathy; (4) cataract formation; (5) effect on perinatal mortality; (6) complications of vascular disease; and (7) the evaluation of various clinical studies suggesting the relationship of elevated blood glucose levels and complications of diabetes mellitus. It is suggested that until the question of control can absolutely be resolved, the recommendation is that the blood glucose levels should be controlled as close to the normal as possible.

  17. Circadian control of glucose metabolism.

    PubMed

    Kalsbeek, Andries; la Fleur, Susanne; Fliers, Eric

    2014-07-01

    The incidence of obesity and type 2 diabetes mellitus (T2DM) has risen to epidemic proportions. The pathophysiology of T2DM is complex and involves insulin resistance, pancreatic β-cell dysfunction and visceral adiposity. It has been known for decades that a disruption of biological rhythms (which happens the most profoundly with shift work) increases the risk of developing obesity and T2DM. Recent evidence from basal studies has further sparked interest in the involvement of daily rhythms (and their disruption) in the development of obesity and T2DM. Most living organisms have molecular clocks in almost every tissue, which govern rhythmicity in many domains of physiology, such as rest/activity rhythms, feeding/fasting rhythms, and hormonal secretion. Here we present the latest research describing the specific role played by the molecular clock mechanism in the control of glucose metabolism and speculate on how disruption of these tissue clocks may lead to the disturbances in glucose homeostasis.

  18. Sex steroids and glucose metabolism.

    PubMed

    Allan, Carolyn A

    2014-01-01

    Testosterone levels are lower in men with metabolic syndrome and type 2 diabetes mellitus (T2DM) and also predict the onset of these adverse metabolic states. Body composition (body mass index, waist circumference) is an important mediator of this relationship. Sex hormone binding globulin is also inversely associated with insulin resistance and T2DM but the data regarding estrogen are inconsistent. Clinical models of androgen deficiency including Klinefelter's syndrome and androgen deprivation therapy in the treatment of advanced prostate cancer confirm the association between androgens and glucose status. Experimental manipulation of the insulin/glucose milieu and suppression of endogenous testicular function suggests the relationship between androgens and insulin sensitivity is bidirectional. Androgen therapy in men without diabetes is not able to differentiate the effect on insulin resistance from that on fat mass, in particular visceral adiposity. Similarly, several small clinical studies have examined the efficacy of exogenous testosterone in men with T2DM, however, the role of androgens, independent of body composition, in modifying insulin resistance is uncertain.

  19. Pancreatic regulation of glucose homeostasis

    PubMed Central

    Röder, Pia V; Wu, Bingbing; Liu, Yixian; Han, Weiping

    2016-01-01

    In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed. PMID:26964835

  20. Short-Term Thermal-Humidity Shock Affects Point-of-Care Glucose Testing: Implications for Health Professionals and Patients.

    PubMed

    Lam, Mandy; Louie, Richard F; Curtis, Corbin M; Ferguson, William J; Vy, John H; Truong, Anh-Thu; Sumner, Stephanie L; Kost, Gerald J

    2014-01-01

    The objective was to assess the effects of short-term (≤1 hour) static high temperature and humidity stresses on the performance of point-of-care (POC) glucose test strips and meters. Glucose meters are used by medical responders and patients in a variety of settings including hospitals, clinics, homes, and the field. Reagent test strips and instruments are potentially exposed to austere environmental conditions. Glucose test strips and meters were exposed to a mean relative humidity of 83.0% (SD = 8.0%) and temperature of 42°C (107.6°F, SD = 3.2) in a Tenney BTRC environmental chamber. Stressed and unstressed glucose reagent strips and meters were tested with spiked blood samples (n = 40 measurements per time point for each of 4 trials) after 15, 30, 45, and 60 minutes of exposure. Wilcoxon's signed rank test was applied to compare measurements test strip and meter measurements to isolate and characterize the magnitude of meter versus test strip effects individually. Stressed POC meters and test strips produced elevated glucose results, with stressed meter bias as high as 20 mg/dL (17.7% error), and stressed test strip bias as high as 13 mg/dL (12.2% error). The aggregate stress effect on meter and test strips yielded a positive bias as high as 33 mg/dL (30.1% error) after 15 minutes of exposure. Short-term exposure (15 minutes) to high temperature and humidity can significantly affect the performance of POC glucose test strips and meters, with measurement biases that potentially affect clinical decision making and patient safety.

  1. Application of Semipermeable Membranes in Glucose Biosensing

    PubMed Central

    Kulkarni, Tanmay; Slaughter, Gymama

    2016-01-01

    Glucose biosensors have received significant attention in recent years due to the escalating mortality rate of diabetes mellitus. Although there is currently no cure for diabetes mellitus, individuals living with diabetes can lead a normal life by maintaining tight control of their blood glucose levels using glucose biosensors (e.g., glucometers). Current research in the field is focused on the optimization and improvement in the performance of glucose biosensors by employing a variety of glucose selective enzymes, mediators and semipermeable membranes to improve the electron transfer between the active center of the enzyme and the electrode substrate. Herein, we summarize the different semipermeable membranes used in the fabrication of the glucose biosensor, that result in improved biosensor sensitivity, selectivity, dynamic range, response time and stability. PMID:27983630

  2. Bioluminescence Imaging of Glucose in Tissue Surrounding Polyurethane and Glucose Sensor Implants

    PubMed Central

    Prichard, Heather L; Schroeder, Thies; Reichert, William M; Klitzman, Bruce

    2010-01-01

    Background The bioluminescence technique was used to quantify the local glucose concentration in the tissue surrounding subcutaneously implanted polyurethane material and surrounding glucose sensors. In addition, some implants were coated with a single layer of adipose-derived stromal cells (ASCs) because these cells improve the wound-healing response around biomaterials. Methods Control and ASC-coated implants were implanted subcutaneously in rats for 1 or 8 weeks (polyurethane) or for 1 week only (glucose sensors). Tissue biopsies adjacent to the implant were immediately frozen at the time of explant. Cryosections were assayed for glucose concentration profile using the bioluminescence technique. Results For the polyurethane samples, no significant differences in glucose concentration within 100 μm of the implant surface were found between bare and ASC-coated implants at 1 or 8 weeks. A glucose concentration gradient was demonstrated around the glucose sensors. For all sensors, the minimum glucose concentration of approximately 4 mM was found at the implant surface and increased with distance from the sensor surface until the glucose concentration peaked at approximately 7 mM at 100 μm. Then the glucose concentration decreased to 5.5–6.5 mM more than 100 μmm from the surface. Conclusions The ASC attachment to polyurethane and to glucose sensors did not change the glucose profiles in the tissue surrounding the implants. Although most glucose sensors incorporate a diffusion barrier to reduce the gradient of glucose and oxygen in the tissue, it is typically assumed that there is no steep glucose gradient around the sensors. However, a glucose gradient was observed around the sensors. A more complete understanding of glucose transport and concentration gradients around sensors is critical. PMID:20920425

  3. Is fructose sweeter than glucose for rats?

    PubMed

    Ramirez, I

    1996-11-01

    Because it is generally thought that the intensity of the taste of fructose is greater than that of glucose for rats, it seemed surprising when sham-fed rats drank substantially less of a mixture of 6% fructose plus saccharin than of a mixture of 6% glucose plus saccharin. At least 3 different factors contribute to this effect. First, the taste of fructose is less attractive to rats than is the taste of glucose; sham-fed rats strongly preferred glucose over fructose (no saccharin was used in this experiment). The second factor is experience. Rats having substantial previous experience with glucose, but not with fructose, consistently preferred glucose over fructose. Conversely, rats having substantial previous experience with fructose, but not with glucose, initially showed no consistent preference but subsequently tended to prefer glucose. The third factor is an interaction between saccharin and the type of sugar. Rats given only one solution at a time drink approximately as much fructose as glucose when the solutions contain no saccharin. The addition of 0.25% saccharin to 6% glucose stimulated intake, whereas the addition of the same amount of saccharin to 6% fructose did not stimulate intake. As a result, rats ingested substantially more of a mixture of 0.25% saccharin plus 6% glucose than they did of a comparable mixture of saccharin and fructose, even though rats ingest similar amounts of fructose and glucose without saccharin in single-bottle tests. Because the differential effect of saccharin on intake appeared within 2 h in naive rats, and did not greatly change over a 3-day period, it is probably not attributable to conditioning. These results suggest that these sugars have qualitatively different tastes.

  4. A self-powered glucose biosensing system.

    PubMed

    Slaughter, Gymama; Kulkarni, Tanmay

    2016-04-15

    A self-powered glucose biosensor (SPGS) system is fabricated and in vitro characterization of the power generation and charging frequency characteristics in glucose analyte are described. The bioelectrodes consist of compressed network of three-dimensional multi-walled carbon nanotubes with redox enzymes, pyroquinoline quinone glucose dehydrogenase (PQQ-GDH) and laccase functioning as the anodic and cathodic catalyst, respectively. When operated in 45 mM glucose, the biofuel cell exhibited an open circuit voltage and power density of 681.8 mV and 67.86 µW/cm(2) at 335 mV, respectively, with a current density of 202.2 µA/cm(2). Moreover, at physiological glucose concentration (5mM), the biofuel cell exhibits open circuit voltage and power density of 302.1 mV and 15.98 µW/cm(2) at 166.3 mV, respectively, with a current density of 100 µA/cm(2). The biofuel cell assembly produced a linear dynamic range of 0.5-45 mM glucose. These findings show that glucose biofuel cells can be further investigated in the development of a self-powered glucose biosensor by using a capacitor as the transducer element. By monitoring the capacitor charging frequencies, which are influenced by the concentration of the glucose analyte, a linear dynamic range of 0.5-35 mM glucose is observed. The operational stability of SPGS is monitored over a period of 63 days and is found to be stable with 15.38% and 11.76% drop in power density under continuous discharge in 10mM and 20mM glucose, respectively. These results demonstrate that SPGSs can simultaneously generate bioelectricity to power ultra-low powered devices and sense glucose.

  5. 76 FR 66925 - Guidance for 1-Hour SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-28

    ..., identified by Docket ID No. EPA-HQ- OAR-2010-1059, by one of the following methods: http://www.regulations... . Attention Docket ID No. EPA-HQ-OAR-2010-1059. Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR- 2010-1059. Mail: Air Docket, Attention Docket ID No. EPA-HQ-OAR-2010- 1059, Environmental Protection...

  6. 76 FR 61098 - Guidance for 1-Hour SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... Docket ID No. EPA-HQ- OAR-2010-1059, by one of the following methods: http://www.regulations.gov . Follow... No. EPA-HQ-OAR-2010-1059. Fax: 202-566-9744. Attention Docket ID No. EPA-HQ-OAR- 2010-1059. Mail: Air Docket, Attention Docket ID No. EPA-HQ-OAR-2010- 1059, Environmental Protection Agency, Mail Code:...

  7. Ocular torsion before and after 1 hour centrifugation.

    PubMed

    Groen, E; De Graaf, B; Bles, W; Bos, J E

    1996-01-01

    To assess a possible otolith contribution to effects observed following prolonged exposure to hypergravity, we used video oculography to measure ocular torsion during static and dynamic conditions of lateral body tilt (roll) before and after 1 h of centrifugation with a Gx-load of 3 G. Static tilt (from 0 to 57 degrees to either side) showed a 10% decrease in otolith-induced ocular torsion after centrifugation. This implies a reduced gain of the otolith function. The dynamic condition consisted of sinusoidal body roll (frequency 0.25 Hz, amplitude 45 degrees) about an earth horizontal and about an earth vertical axis (respectively, "with" and "without" otolith stimulation). Before centrifugation the gain of the slow component velocity (SCV) was significantly lower "with" otolith stimulation than "without" otolith stimulation. Apparently, the contribution of the otoliths counteracts the ocular torsion response generated by the semicircular canals. Therefore, the observed increase in SCV gain in the condition "with" otolith stimulation after centrifugation, seems in correspondence with the decreased otolith gain in the static condition.

  8. Glucose metabolism in rat retinal pigment epithelium.

    PubMed

    Coffe, Víctor; Carbajal, Raymundo C; Salceda, Rocío

    2006-01-01

    The retinal pigment epithelium (RPE) is the major transport pathway for exchange of metabolites and ions between choroidal blood supply and the neural retina. To gain insight into the mechanisms controlling glucose metabolism in RPE and its possible relationship to retinopathy, we studied the influence of different glucose concentrations on glycogen and lactate levels and CO(2) production in RPE from normal and streptozotocin-treated diabetic rats. Incubation of normal RPE in the absence of glucose caused a decrease in lactate production and glycogen content. In normal RPE, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO(2) yield, as well as reduction in lactate and glycogen production. In RPE from diabetic rats glucose accumulation did not increase in the presence of high glucose substrate, but it showed a four- and a seven-fold increase in CO(2) production through the mitochondrial and pentose phosphate pathways, respectively. We found high glycogen levels in RPE which can be used as an energy reserve for RPE itself and/or neural retina. Findings further show that the RPE possesses a high oxidative capacity. The large increase in glucose shunting to the pentose phosphate pathway in diabetic retina exposed to high glucose suggests a need for reducing capacity, consistent with increased oxidative stress.

  9. General aspects of muscle glucose uptake.

    PubMed

    Alvim, Rafael O; Cheuhen, Marcel R; Machado, Silmara R; Sousa, André Gustavo P; Santos, Paulo C J L

    2015-03-01

    Glucose uptake in peripheral tissues is dependent on the translocation of GLUT4 glucose transporters to the plasma membrane. Studies have shown the existence of two major signaling pathways that lead to the translocation of GLUT4. The first, and widely investigated, is the insulin activated signaling pathway through insulin receptor substrate-1 and phosphatidylinositol 3-kinase. The second is the insulin-independent signaling pathway, which is activated by contractions. Individuals with type 2 diabetes mellitus have reduced insulin-stimulated glucose uptake in skeletal muscle due to the phenomenon of insulin resistance. However, those individuals have normal glucose uptake during exercise. In this context, physical exercise is one of the most important interventions that stimulates glucose uptake by insulin-independent pathways, and the main molecules involved are adenosine monophosphate-activated protein kinase, nitric oxide, bradykinin, AKT, reactive oxygen species and calcium. In this review, our main aims were to highlight the different glucose uptake pathways and to report the effects of physical exercise, diet and drugs on their functioning. Lastly, with the better understanding of these pathways, it would be possible to assess, exactly and molecularly, the importance of physical exercise and diet on glucose homeostasis. Furthermore, it would be possible to assess the action of drugs that might optimize glucose uptake and consequently be an important step in controlling the blood glucose levels in diabetic patients, in addition to being important to clarify some pathways that justify the development of drugs capable of mimicking the contraction pathway.

  10. Glucose Transporters in Cardiac Metabolism and Hypertrophy

    PubMed Central

    Shao, Dan; Tian, Rong

    2016-01-01

    The heart is adapted to utilize all classes of substrates to meet the high-energy demand, and it tightly regulates its substrate utilization in response to environmental changes. Although fatty acids are known as the predominant fuel for the adult heart at resting stage, the heart switches its substrate preference toward glucose during stress conditions such as ischemia and pathological hypertrophy. Notably, increasing evidence suggests that the loss of metabolic flexibility associated with increased reliance on glucose utilization contribute to the development of cardiac dysfunction. The changes in glucose metabolism in hypertrophied hearts include altered glucose transport and increased glycolysis. Despite the role of glucose as an energy source, changes in other nonenergy producing pathways related to glucose metabolism, such as hexosamine biosynthetic pathway and pentose phosphate pathway, are also observed in the diseased hearts. This article summarizes the current knowledge regarding the regulation of glucose transporter expression and translocation in the heart during physiological and pathological conditions. It also discusses the signaling mechanisms governing glucose uptake in cardiomyocytes, as well as the changes of cardiac glucose metabolism under disease conditions. PMID:26756635

  11. Diauxic Growth of Azotobacter vinelandii on Galactose and Glucose: Regulation of Glucose Transport by Another Hexose.

    PubMed

    Wong, T Y; Pei, H; Bancroft, K; Childers, G W

    1995-02-01

    The growth curve of Azotobacter vinelandii was biphasic when the organism was grown in a medium containing a mixture of galactose and glucose. Galactose was the primary carbon source; glucose was also consumed, but the rate at which it was consumed was lower than the rate at which galactose was consumed during the first phase of growth. Metabolic pathways for both sugars were induced. Cell cultures exhibited a second lag period as galactose was depleted. The length of this lag phase varied from 2 to 10 h depending on the pregrowth history of the cells. The second log growth phase occurred at the expense of the remaining glucose in the medium and was accompanied by induction of the high-maximum rate of metabolism glucose-induced glucose permease and increases in the levels of glucose metabolic enzymes. The second lag phase of diauxie may have been due to the time required for induction of the glucose-induced glucose permease.

  12. Glucose-6-Phosphate Dehydrogenase Deficiency.

    PubMed

    Luzzatto, Lucio; Nannelli, Caterina; Notaro, Rosario

    2016-04-01

    G6PD is a housekeeping gene expressed in all cells. Glucose-6-phosphate dehydrogenase (G6PD) is part of the pentose phosphate pathway, and its main physiologic role is to provide NADPH. G6PD deficiency, one of the commonest inherited enzyme abnormalities in humans, arises through one of many possible mutations, most of which reduce the stability of the enzyme and its level as red cells age. G6PD-deficient persons are mostly asymptomatic, but they can develop severe jaundice during the neonatal period and acute hemolytic anemia when they ingest fava beans or when they are exposed to certain infections or drugs. G6PD deficiency is a global health issue.

  13. Evidence that humans can taste glucose polymers.

    PubMed

    Lapis, Trina J; Penner, Michael H; Lim, Juyun

    2014-11-01

    The sense of taste is essential for identifying potential nutrients and poisons. Accordingly, specialized taste receptor cells are activated by food-derived chemicals. Because of its importance in the human diet, oral detection of starch, or its degradation products, would presumably be highly beneficial. Yet, it has long been assumed that simple sugars are the only class of carbohydrates that humans can taste. There is, however, considerable evidence that rodents can taste starch degradation products (i.e., glucose polymers composed of maltooligosaccharides with 3-10 glucose units and maltopolysaccharides with >10 glucose units) and that their detection is independent of the sweet taste receptor, T1R2/T1R3. The present study was designed 1) to measure individual differences in human taste perception of glucose polymers, 2) to understand individual differences in the activity of salivary α-amylase, and 3) to investigate the role that salivary α-amylase may play in the taste perception of glucose polymers. In the first experiment, subjects rated taste intensity of glucose, sucrose, NaCl, and glucose polymers of various chain lengths, while their noses were clamped. Saliva samples from the subjects were also collected and their salivary α-amylase activity was assayed. Results showed that the perceived intensities of glucose, sucrose, and NaCl were significantly correlated (r = 0.75-0.85, P < 0.001), but not with the longer chain glucose polymers, whereas intensity ratings of all glucose polymers were highly correlated with one another (r = 0.69-0.82, P < 0.001). Importantly, despite large individual differences in α-amylase activity among subjects, responsiveness to glucose polymers did not significantly differ between individuals with high and low α-amylase activity. A follow up experiment was conducted to quantify the concentrations of glucose and maltose that were inherently present in the glucose polymer stimuli and to determine whether the amounts were

  14. Hypothalamic glucose sensing: making ends meet

    PubMed Central

    Routh, Vanessa H.; Hao, Lihong; Santiago, Ammy M.; Sheng, Zhenyu; Zhou, Chunxue

    2014-01-01

    The neuroendocrine system governs essential survival and homeostatic functions. For example, growth is needed for development, thermoregulation maintains optimal core temperature in a changing environment, and reproduction ensures species survival. Stress and immune responses enable an organism to overcome external and internal threats while the circadian system regulates arousal and sleep such that vegetative and active functions do not overlap. All of these functions require a significant portion of the body's energy. As the integrator of the neuroendocrine system, the hypothalamus carefully assesses the energy status of the body in order to appropriately partition resources to provide for each system without compromising the others. While doing so the hypothalamus must ensure that adequate glucose levels are preserved for brain function since glucose is the primary fuel of the brain. To this end, the hypothalamus contains specialized glucose sensing neurons which are scattered throughout the nuclei controlling distinct neuroendocrine functions. We hypothesize that these neurons play a key role in enabling the hypothalamus to partition energy to meet these peripheral survival needs without endangering the brain's glucose supply. This review will first describe the varied mechanisms underlying glucose sensing in neurons within discrete hypothalamic nuclei. We will then evaluate the way in which peripheral energy status regulates glucose sensitivity. For example, during energy deficit such as fasting specific hypothalamic glucose sensing neurons become sensitized to decreased glucose. This increases the gain of the information relay when glucose availability is a greater concern for the brain. Finally, changes in glucose sensitivity under pathological conditions (e.g., recurrent insulin-hypoglycemia, diabetes) will be addressed. The overall goal of this review is to place glucose sensing neurons within the context of hypothalamic control of neuroendocrine function

  15. Feedback Regulation of Glucose Transporter Gene Transcription in Kluyveromyces lactis by Glucose Uptake

    PubMed Central

    Milkowski, C.; Krampe, S.; Weirich, J.; Hasse, V.; Boles, E.; Breunig, K. D.

    2001-01-01

    In the respirofermentative yeast Kluyveromyces lactis, only a single genetic locus encodes glucose transporters that can support fermentative growth. This locus is polymorphic in wild-type isolates carrying either KHT1 and KHT2, two tandemly arranged HXT-like genes, or RAG1, a low-affinity transporter gene that arose by recombination between KHT1 and KHT2. Here we show that KHT1 is a glucose-induced gene encoding a low-affinity transporter very similar to Rag1p. Kht2p has a lower Km (3.7 mM) and a more complex regulation. Transcription is high in the absence of glucose, further induced by low glucose concentrations, and repressed at higher glucose concentrations. The response of KHT1 and KHT2 gene regulation to high but not to low concentrations of glucose depends on glucose transport. The function of either Kht1p or Kht2p is sufficient to mediate the characteristic response to high glucose, which is impaired in a kht1 kht2 deletion mutant. Thus, the KHT genes are subject to mutual feedback regulation. Moreover, glucose repression of the endogenous β-galactosidase (LAC4) promoter and glucose induction of pyruvate decarboxylase were abolished in the kht1 kht2 mutant. These phenotypes could be partially restored by HXT gene family members from Saccharomyces cerevisiae. The results indicate that the specific responses to high but not to low glucose concentrations require a high rate of glucose uptake. PMID:11514503

  16. Glucose-Induced Acidification in Yeast Cultures

    ERIC Educational Resources Information Center

    Myers, Alan; Bourn, Julia; Pool, Brynne

    2005-01-01

    We present an investigation (for A-level biology students and equivalent) into the mechanism of glucose-induced extracellular acidification in unbuffered yeast suspensions. The investigation is designed to enhance understanding of aspects of the A-level curriculum that relate to the phenomenon (notably glucose catabolism) and to develop key skills…

  17. Molecular Pathophysiology of Hepatic Glucose Production

    PubMed Central

    Sharabi, Kfir; Tavares, Clint D. J.; Rines, Amy K.; Puigserver, Pere

    2015-01-01

    Maintaining blood glucose concentration within a relatively narrow range through periods of fasting or excess nutrient availability is essential to the survival of the organism. This is achieved through an intricate balance between glucose uptake and endogenous glucose production to maintain constant glucose concentrations. The liver plays a major role in maintaining normal whole body glucose levels by regulating the processes of de novo glucose production (gluconeogenesis) and glycogen breakdown (glycogenolysis), thus controlling the levels of hepatic glucose release. Aberrant regulation of hepatic glucose production (HGP) can result in deleterious clinical outcomes, and excessive HGP is a major contributor to the hyperglycemia observed in Type 2 diabetes mellitus (T2DM). Indeed, adjusting glycaemia as close as possible to a non-diabetic range is the foremost objective in the medical treatment of patients with T2DM and is currently achieved in the clinic primarily through suppression of HGP. Here, we review the molecular mechanisms controlling HGP in response to nutritional and hormonal signals and discuss how these signals are altered in T2DM. PMID:26549348

  18. Toward a Continuous Intravascular Glucose Monitoring System

    PubMed Central

    Beier, Brooke; Musick, Katherine; Matsumoto, Akira; Panitch, Alyssa; Nauman, Eric; Irazoqui, Pedro

    2011-01-01

    Proof-of-concept studies that display the potential of using a glucose-sensitive hydrogel as a continuous glucose sensor are presented. The swelling ratio, porosity, and diffusivity of the hydrogel increased with glucose concentration. In glucose solutions of 50, 100, 200, and 300 mg/dL, the hydrogel swelling ratios were 4.9, 12.3, 15.9, and 21.7, respectively, and the swelling was reversible. The impedance across the hydrogel depended solely on the thickness and had an average increase of 47 Ω/mm. The hydrogels exposed to a hyperglycemic solution were more porous than the hydrogels exposed to a normal glycemic solution. The diffusivity of 390 Da MW fluorescein isothiocyanate in hydrogels exposed to normal and hyperglycemic solutions was examined using fluorescence recovery after photobleaching and was found to be 9.3 × 10−14 and 41.4 × 10−14 m2/s, respectively, compared to 6.2 × 10−10 m2/s in glucose solution. There was no significant difference between the permeability of hydrogels in normal and hyperglycemic glucose solutions with averages being 5.26 × 10−17 m2 and 5.80 × 10−17 m2, respectively, which resembles 2–4% agarose gels. A prototype design is presented for continuous intravascular glucose monitoring by attaching a glucose sensor to an FDA-approved stent. PMID:22344366

  19. Molecular pathophysiology of hepatic glucose production.

    PubMed

    Sharabi, Kfir; Tavares, Clint D J; Rines, Amy K; Puigserver, Pere

    2015-12-01

    Maintaining blood glucose concentration within a relatively narrow range through periods of fasting or excess nutrient availability is essential to the survival of the organism. This is achieved through an intricate balance between glucose uptake and endogenous glucose production to maintain constant glucose concentrations. The liver plays a major role in maintaining normal whole body glucose levels by regulating the processes of de novo glucose production (gluconeogenesis) and glycogen breakdown (glycogenolysis), thus controlling the levels of hepatic glucose release. Aberrant regulation of hepatic glucose production (HGP) can result in deleterious clinical outcomes, and excessive HGP is a major contributor to the hyperglycemia observed in Type 2 diabetes mellitus (T2DM). Indeed, adjusting glycemia as close as possible to a non-diabetic range is the foremost objective in the medical treatment of patients with T2DM and is currently achieved in the clinic primarily through suppression of HGP. Here, we review the molecular mechanisms controlling HGP in response to nutritional and hormonal signals and discuss how these signals are altered in T2DM.

  20. [Intracellular signals involved in glucose control].

    PubMed

    Cruz, M; Velasco, E; Kumate, J

    2001-01-01

    Many proteins are involved in glucose control. The first step for glucose uptake is insulin receptor-binding. Stimulation of the insulin receptor results in rapid autophosphorylation and conformational changes in the beta chain and the subsequent phosphorylation of the insulin receptor substrate. This results in the docking of several SH2 domain proteins, including PI 3-kinase and other adapters. The final event is glucose transporter (GLUT) translocation to the cell surface. GLUT is in the cytosol but after insulin stimulation, several proteins are activated either in the GLUT vesicles or in the inner membrane. The role of the cytoskeleton is not well known, but it apparently participates in membrane fusion and vesicle mobilization. After glucose uptake, several hexokines metabolize the glucose to generate energy, convert the glucose in glycogen and store it. Type 2 diabetes is characterized by high glucose levels and insulin resistance. The insulin receptor is diminished on the cell surface membrane, tyrosine phosphorylation is decreased, serine and threonine phosphorylation is augmented. Apparently, the main problem with GLUT protein is in its translocation to the cell surface. At present, we know the role of many proteins involved in glucose control. However, we do not understand the significance of insulin resistance at the molecular level with type 2 diabetes.

  1. Glucose Disappearance in Biological Treatment Systems

    PubMed Central

    Jeris, John S.; Cardenas, Raul R.

    1966-01-01

    Laboratory scale anaerobic and aerobic treatment units were conditioned with a daily slug-feed of glucose. After a period of acclimation and stabilization, glucose disappearance was monitored continuously after the slug feed. A continuous sampling apparatus is described. Mathematical analysis of the data indicate zero-order reactions for both biological treatment systems. PMID:16349685

  2. Glucose kinetics during prolonged exercise in highly trained human subjects: effect of glucose ingestion

    PubMed Central

    Jeukendrup, Asker E; Raben, Anne; Gijsen, Annemie; Stegen, Jos H C H; Brouns, Fred; Saris, Wim H M; Wagenmakers, Anton J M

    1999-01-01

    The objectives of this study were (1) to investigate whether glucose ingestion during prolonged exercise reduces whole body muscle glycogen oxidation, (2) to determine the extent to which glucose disappearing from the plasma is oxidized during exercise with and without carbohydrate ingestion and (3) to obtain an estimate of gluconeogenesis. After an overnight fast, six well-trained cyclists exercised on three occasions for 120 min on a bicycle ergometer at 50% maximum velocity of O2 uptake and ingested either water (Fast), or a 4% glucose solution (Lo-Glu) or a 22% glucose solution (Hi-Glu) during exercise. Dual tracer infusion of [U-13C]-glucose and [6,6-2H2]-glucose was given to measure the rate of appearance (Ra) of glucose, muscle glycogen oxidation, glucose carbon recycling, metabolic clearance rate (MCR) and non-oxidative disposal of glucose. Glucose ingestion markedly increased total Ra especially with Hi-Glu. After 120 min Ra and rate of disappearance (Rd) of glucose were 51-52 μmol kg−1 min−1 during Fast, 73-74 μmol kg−1 min−1 during Lo-Glu and 117–119 μmol kg−1 min−1 during Hi-Glu. The percentage of Rd oxidized was between 96 and 100% in all trials. Glycogen oxidation during exercise was not reduced by glucose ingestion. The vast majority of glucose disappearing from the plasma is oxidized and MCR increased markedly with glucose ingestion. Glucose carbon recycling was minimal suggesting that gluconeogenesis in these conditions is negligible. PMID:10050023

  3. Effect of Portal Glucose Sensing on Systemic Glucose Levels in SD and ZDF Rats

    PubMed Central

    Pal, Atanu; Rhoads, David B.; Tavakkoli, Ali

    2016-01-01

    Background The global epidemic of Type-2-Diabetes (T2D) highlights the need for novel therapeutic targets and agents. Roux-en-Y-Gastric-Bypass (RYGB) is the most effective treatment. Studies investigating the mechanisms of RYGB suggest a role for post-operative changes in portal glucose levels. We investigate the impact of stimulating portal glucose sensors on systemic glucose levels in health and T2D, and evaluated the role of sodium-glucose-cotransporter-3 (SGLT3) as the possible sensor. Methods Systemic glucose and hormone responses to portal stimulation were measured. In Sprague-Dawley (SD) rats, post-prandial state was simulated by infusing glucose into the portal vein. The SGLT3 agonist, alpha-methyl-glucopyranoside (αMG), was then added to further stimulate the portal sensor. To elucidate the neural pathway, vagotomy or portal denervation was followed by αMG+glucose co-infusion. The therapeutic potential of portal glucose sensor stimulation was investigated by αMG-only infusion (vs. saline) in SD and Zucker-Diabetic-Fatty (ZDF) rats. Hepatic mRNA expression was also measured. Results αMG+glucose co-infusion reduced peak systemic glucose (vs. glucose alone), and lowered hepatic G6Pase expression. Portal denervation, but not vagotomy, abolished this effect. αMG-only infusion lowered systemic glucose levels. This glucose-lowering effect was more pronounced in ZDF rats, where portal αMG infusion increased insulin, C-peptide and GIP levels compared to saline infusions. Conclusions The portal vein is capable of sensing its glucose levels, and responds by altering hepatic glucose handling. The enhanced effect in T2D, mediated through increased GIP and insulin, highlights a therapeutic target that could be amenable to pharmacological modulation or minimally-invasive surgery. PMID:27806092

  4. 21 CFR 862.1345 - Glucose test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Glucose test system. 862.1345 Section 862.1345....1345 Glucose test system. (a) Identification. A glucose test system is a device intended to measure glucose quantitatively in blood and other body fluids. Glucose measurements are used in the diagnosis...

  5. Canagliflozin Lowers Postprandial Glucose and Insulin by Delaying Intestinal Glucose Absorption in Addition to Increasing Urinary Glucose Excretion

    PubMed Central

    Polidori, David; Sha, Sue; Mudaliar, Sunder; Ciaraldi, Theodore P.; Ghosh, Atalanta; Vaccaro, Nicole; Farrell, Kristin; Rothenberg, Paul; Henry, Robert R.

    2013-01-01

    OBJECTIVE Canagliflozin, a sodium glucose cotransporter (SGLT) 2 inhibitor, is also a low-potency SGLT1 inhibitor. This study tested the hypothesis that intestinal canagliflozin levels postdose are sufficiently high to transiently inhibit intestinal SGLT1, thereby delaying intestinal glucose absorption. RESEARCH DESIGN AND METHODS This two-period, crossover study evaluated effects of canagliflozin on intestinal glucose absorption in 20 healthy subjects using a dual-tracer method. Placebo or canagliflozin 300 mg was given 20 min before a 600-kcal mixed-meal tolerance test. Plasma glucose, 3H-glucose, 14C-glucose, and insulin were measured frequently for 6 h to calculate rates of appearance of oral glucose (RaO) in plasma, endogenous glucose production, and glucose disposal. RESULTS Compared with placebo, canagliflozin treatment reduced postprandial plasma glucose and insulin excursions (incremental 0- to 2-h area under the curve [AUC0–2h] reductions of 35% and 43%, respectively; P < 0.001 for both), increased 0- to 6-h urinary glucose excretion (UGE0–6h, 18.2 ± 5.6 vs. <0.2 g; P < 0.001), and delayed RaO. Canagliflozin reduced AUC RaO by 31% over 0 to 1 h (geometric means, 264 vs. 381 mg/kg; P < 0.001) and by 20% over 0 to 2 h (576 vs. 723 mg/kg; P = 0.002). Over 2 to 6 h, canagliflozin increased RaO such that total AUC RaO over 0 to 6 h was <6% lower versus placebo (960 vs. 1,018 mg/kg; P = 0.003). A modest (∼10%) reduction in acetaminophen absorption was observed over the first 2 h, but this difference was not sufficient to explain the reduction in RaO. Total glucose disposal over 0 to 6 h was similar across groups. CONCLUSIONS Canagliflozin reduces postprandial plasma glucose and insulin by increasing UGE (via renal SGLT2 inhibition) and delaying RaO, likely due to intestinal SGLT1 inhibition. PMID:23412078

  6. Glucose Recognition in Vitro Using Fluorescent Spectroscopy

    SciTech Connect

    Noronha, G; Heiss, A M; Reilly, J R; Vachon, Jr, D J; Cary, D R; Zaitseva, N P; Reibold, R A; Lane, S M; Peyser, T A; Satcher, J H

    2001-04-25

    Diabetes is a disease that affects over 16 million people in the USA at a cost of 100 billion dollars annually. The ability to regulate insulin delivery in people with Type 1 diabetes is imperative as is the need to manage glucose levels in all people with this disease. Our current method for monitoring glucose is a (FDA approved) minimally invasive enzymatic sensor that can measure glucose levels in vivo for three days. We are focused on developing a noninvasive implantable glucose sensor that will be interrogated by an external device. The material must be robust, easy to process, biocompatible and resistant to biofouling. In this Presentation we will discuss the development of a new polymeric matrix that can recognize physiological levels of glucose in vitro using fluorescent spectroscopy.

  7. Diurnal Variation in Response to Intravenous Glucose*

    PubMed Central

    Whichelow, Margaret J.; Sturge, R. A.; Keen, H.; Jarrett, R. J.; Stimmler, L.; Grainger, Susan

    1974-01-01

    Intravenous glucose tolerance tests (25 g) were performed in the morning and afternoon on 13 apparently normal persons. The individual K values (rate of decline of blood sugar) were all higher in the morning tests, and the mean values were significantly higher in the morning. Fasting blood sugar levels were slightly lower in the afternoon. There was no difference between the fasting morning and afternoon plasma insulin levels, but the levels after glucose were lower in the afternoon. Growth hormone levels were low at all times in non-apprehensive subjects and unaffected by glucose. The results suggest that the impaired afternoon intravenous glucose tolerance, like oral glucose tolerance, is associated with impaired insulin release and insulin resistance. PMID:4817160

  8. Glucose Biosensor Based on Immobilization of Glucose Oxidase in Platinum Nanoparticles/Graphene/Chitosan Nanocomposite Film

    SciTech Connect

    Wu, Hong; Wang, Jun; Kang, Xinhuang; Wang, Chong M.; Wang, Donghai; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2009-09-01

    The bionanocomposite film consisting of glucose oxidase/Pt/functional graphene sheets/chitosan (GOD/Pt/FGS/chitosan) for glucose sensing was described. With the electrocatalytic synergy of FGS and Pt nanoparticles to hydrogen peroxide, a sensitive biosensor with detection limit of 0.6 µM glucose was achieved. The biosensor also had good reproducibility, long term stability and negligible interfering signals from ascorbic acid and uric acid comparing to the response to glucose. The large surface area and good conductivity of graphene suggests that graphene is a potential candidate for sensor material. The hybrid nanocomposite glucose sensor provides new opportunity for clinical diagnosis and point-of-care applications.

  9. Contribution of glucose kinase to glucose repression of xylose utilization in Bacillus megaterium.

    PubMed Central

    Späth, C; Kraus, A; Hillen, W

    1997-01-01

    The glk gene from Bacillus megaterium, which encodes glucose kinase, was isolated and analyzed. Disruption by a transcriptional glk-luxAB fusion indicated that glk is the only glucose kinase gene in that strain but did not affect growth of that mutant on glucose. Determination of luciferase activity under various growth conditions revealed constitutive transcription of glk. Expression of a xylA-lacZ fusion was repressed by glucose in the strain with the glk disruption about twofold less efficiently than in the wild type. The potential contribution of glk expression to glucose repression is discussed. PMID:9393732

  10. Identification of Glucose Transporters in Aspergillus nidulans

    PubMed Central

    dos Reis, Thaila Fernanda; Menino, João Filipe; Bom, Vinícius Leite Pedro; Brown, Neil Andrew; Colabardini, Ana Cristina; Savoldi, Marcela; Goldman, Maria Helena S.; Rodrigues, Fernando; Goldman, Gustavo Henrique

    2013-01-01

    To characterize the mechanisms involved in glucose transport, in the filamentous fungus Aspergillus nidulans, we have identified four glucose transporter encoding genes hxtB-E. We evaluated the ability of hxtB-E to functionally complement the Saccharomyces cerevisiae EBY.VW4000 strain that is unable to grow on glucose, fructose, mannose or galactose as single carbon source. In S. cerevisiae HxtB-E were targeted to the plasma membrane. The expression of HxtB, HxtC and HxtE was able to restore growth on glucose, fructose, mannose or galactose, indicating that these transporters accept multiple sugars as a substrate through an energy dependent process. A tenfold excess of unlabeled maltose, galactose, fructose, and mannose were able to inhibit glucose uptake to different levels (50 to 80 %) in these s. cerevisiae complemented strains. Moreover, experiments with cyanide-m-chlorophenylhydrazone (CCCP), strongly suggest that hxtB, -C, and –E mediate glucose transport via active proton symport. The A. nidulans ΔhxtB, ΔhxtC or ΔhxtE null mutants showed ~2.5-fold reduction in the affinity for glucose, while ΔhxtB and -C also showed a 2-fold reduction in the capacity for glucose uptake. The ΔhxtD mutant had a 7.8-fold reduction in affinity, but a 3-fold increase in the capacity for glucose uptake. However, only the ΔhxtB mutant strain showed a detectable decreased rate of glucose consumption at low concentrations and an increased resistance to 2-deoxyglucose. PMID:24282591

  11. Glucose-dependent insulinotropic polypeptide directly induces glucose transport in rat skeletal muscle.

    PubMed

    Snook, Laelie A; Nelson, Emery M; Dyck, David J; Wright, David C; Holloway, Graham P

    2015-08-01

    Several gastrointestinal proteins have been identified to have insulinotropic effects, including glucose-dependent insulinotropic polypeptide (GIP); however, the direct effects of incretins on skeletal muscle glucose transport remain largely unknown. Therefore, the purpose of the current study was to examine the role of GIP on skeletal muscle glucose transport and insulin signaling in rats. Relative to a glucose challenge, a mixed glucose+lipid oral challenge increased circulating GIP concentrations, skeletal muscle Akt phosphorylation, and improved glucose clearance by ∼35% (P < 0.05). These responses occurred without alterations in serum insulin concentrations. In an incubated soleus muscle preparation, GIP directly stimulated glucose transport and increased GLUT4 accumulation on the plasma membrane in the absence of insulin. Moreover, the ability of GIP to stimulate glucose transport was mitigated by the addition of the PI 3-kinase (PI3K) inhibitor wortmannin, suggesting that signaling through PI3K is required for these responses. We also provide evidence that the combined stimulatory effects of GIP and insulin on soleus muscle glucose transport are additive. However, the specific GIP receptor antagonist (Pro(3))GIP did not attenuate GIP-stimulated glucose transport, suggesting that GIP is not signaling through its classical receptor. Together, the current data provide evidence that GIP regulates skeletal muscle glucose transport; however, the exact signaling mechanism(s) remain unknown.

  12. Cell based metabolic barriers to glucose diffusion: macrophages and continuous glucose monitoring.

    PubMed

    Klueh, Ulrike; Frailey, Jackman T; Qiao, Yi; Antar, Omar; Kreutzer, Donald L

    2014-03-01

    It is assumed that MQ are central to glucose sensor bio-fouling and therefore have a major negative impact on continuous glucose monitoring (CGM) performance in vivo. However to our knowledge there is no data in the literature to directly support or refute this assumption. Since glucose and oxygen (O2) are key to glucose sensor function in vivo, understanding and controlling glucose and O2 metabolic activity of MQ is likely key to successful glucose sensor performance. We hypothesized that the accumulation of MQ at the glucose sensor-tissue interface will act as "Cell Based Metabolic Barriers" (CBMB) to glucose diffusing from the interstitial tissue compartment to the implanted glucose sensor and as such creating an artificially low sensor output, thereby compromising sensor function and CGM. Our studies demonstrated that 1) direct injections of MQ at in vivo sensor implantation sites dramatically decreased sensor output (measured in nA), 2) addition of MQ to glucose sensors in vitro resulted in a rapid and dramatic fall in sensor output and 3) lymphocytes did not affect sensor function in vitro or in vivo. These data support our hypothesis that MQ can act as metabolic barriers to glucose and O2 diffusion in vivo and in vitro.

  13. Glucose sensing mechanisms in hypothalamic cell models: glucose inhibition of AgRP synthesis and secretion.

    PubMed

    Chalmers, Jennifer A; Jang, Janet J; Belsham, Denise D

    2014-01-25

    Glucose-sensing neurons play a role in energy homeostasis, yet how orexigenic neurons sense glucose remains unclear. As models of glucose-inhibited (GI) neurons, mHypoE-29/1 and mHypoA-NPY/GFP cells express the essential orexigenic neuropeptide AgRP and glucose sensing machinery. Exposure to increasing concentrations of glucose or the glucose analog 2-deoxyglucose (2-DG) results in a decrease in AgRP mRNA levels. Taste receptor, Tas1R2 mRNA expression was reduced by glucose, whereas 2-DG reduced Tas1R3 mRNA levels. Increasing glucose concentrations elicited a rise in Akt and neuronal nitric oxide synthase (nNOS) phosphorylation, CaMKKβ levels, and a reduction of AMP-kinase alpha phosphorylation. Inhibitors of NOS and the cystic fibrosis transmembrane conductance regulator (CFTR) prevented a decrease in AgRP secretion with glucose, suggesting a pivotal role for nNOS and the CFTR in glucose-sensing. These models possess the hallmark characteristics of GI neurons, and can be used to disentangle the mechanisms by which orexigenic neurons sense glucose.

  14. Glucose biosensor based on nanocomposite films of CdTe quantum dots and glucose oxidase.

    PubMed

    Li, Xinyu; Zhou, Yunlong; Zheng, Zhaozhu; Yue, Xiuli; Dai, Zhifei; Liu, Shaoqin; Tang, Zhiyong

    2009-06-02

    A blood glucose sensor has been developed based on the multilayer films of CdTe semiconductor quantum dots (QDs) and glucose oxidase (GOD) by using the layer-by-layer assembly technique. When the composite films were contacted with glucose solution, the photoluminescence of QDs in the films was quickly quenched because the enzyme-catalyzed reaction product (H2O2) of GOD and glucose gave rise to the formation of surface defects on QDs. The quenching rate was a function of the concentration of glucose. The linear range and sensitivity for glucose determination could be adjusted by controlling the layers of QDs and GOD. The biosensor was used to successfully determine the concentration of blood glucose in real serum samples without sample pretreatment and exhibited satisfactory reproducibility and accuracy.

  15. Yeast AMP-activated Protein Kinase Monitors Glucose Concentration Changes and Absolute Glucose Levels*

    PubMed Central

    Bendrioua, Loubna; Smedh, Maria; Almquist, Joachim; Cvijovic, Marija; Jirstrand, Mats; Goksör, Mattias; Adiels, Caroline B.; Hohmann, Stefan

    2014-01-01

    Analysis of the time-dependent behavior of a signaling system can provide insight into its dynamic properties. We employed the nucleocytoplasmic shuttling of the transcriptional repressor Mig1 as readout to characterize Snf1-Mig1 dynamics in single yeast cells. Mig1 binds to promoters of target genes and mediates glucose repression. Mig1 is predominantly located in the nucleus when glucose is abundant. Upon glucose depletion, Mig1 is phosphorylated by the yeast AMP-activated kinase Snf1 and exported into the cytoplasm. We used a three-channel microfluidic device to establish a high degree of control over the glucose concentration exposed to cells. Following regimes of glucose up- and downshifts, we observed a very rapid response reaching a new steady state within less than 1 min, different glucose threshold concentrations depending on glucose up- or downshifts, a graded profile with increased cell-to-cell variation at threshold glucose concentrations, and biphasic behavior with a transient translocation of Mig1 upon the shift from high to intermediate glucose concentrations. Fluorescence loss in photobleaching and fluorescence recovery after photobleaching data demonstrate that Mig1 shuttles constantly between the nucleus and cytoplasm, although with different rates, depending on the presence of glucose. Taken together, our data suggest that the Snf1-Mig1 system has the ability to monitor glucose concentration changes as well as absolute glucose levels. The sensitivity over a wide range of glucose levels and different glucose concentration-dependent response profiles are likely determined by the close integration of signaling with the metabolism and may provide for a highly flexible and fast adaptation to an altered nutritional status. PMID:24627493

  16. Glucose uptake saturation explains glucose kinetics profiles measured by different tests.

    PubMed

    Bizzotto, Roberto; Natali, Andrea; Gastaldelli, Amalia; Muscelli, Elza; Krssak, Martin; Brehm, Attila; Roden, Michael; Ferrannini, Ele; Mari, Andrea

    2016-08-01

    It is known that for a given insulin level glucose clearance depends on glucose concentration. However, a quantitative representation of the concomitant effects of hyperinsulinemia and hyperglycemia on glucose clearance, necessary to describe heterogeneous tests such as euglycemic and hyperglycemic clamps and oral tests, is lacking. Data from five studies (123 subjects) using a glucose tracer and including all the above tests in normal and diabetic subjects were collected. A mathematical model was developed in which glucose utilization was represented as a Michaelis-Menten function of glucose with constant Km and insulin-controlled Vmax, consistently with the basic notions of glucose transport. Individual values for the model parameters were estimated using a population approach. Tracer data were accurately fitted in all tests. The estimated Km was 3.88 (2.83-5.32) mmol/l [median (interquartile range)]. Median model-derived glucose clearance at 600 pmol/l insulin was reduced from 246 to 158 ml·min(-1)·m(-2) when glucose was raised from 5 to 10 mmol/l. The model reproduced the characteristic lack of increase in glucose clearance when moderate hyperinsulinemia was accompanied by hyperglycemia. In all tests, insulin sensitivity was inversely correlated with BMI, as expected (R(2) = 0.234, P = 0.0001). In conclusion, glucose clearance in euglycemic and hyperglycemic clamps and oral tests can be described with a unifying model, consistent with the notions of glucose transport and able to reproduce the suppression of glucose clearance due to hyperglycemia observed in previous studies. The model may be important for the design of reliable glucose homeostasis simulators.

  17. Expression of Glucose Transporter 4 (GLUT4) is Increased by Cinnamaldehyde in C2C12 Mouse Muscle Cells

    PubMed Central

    Nikzamir, Abdolrahim; Palangi, Alireza; Kheirollaha, Alireza; Tabar, Hashemi; Malakaskar, Alimohamad; Shahbazian, Hajieh; Fathi, Mohammad

    2014-01-01

    Background: In diabetes mellitus because of the absence or insufficient sensitivity to insulin, glucose transporter protein in cell membrane, glucose transporter 4, is decreased. GLUT4 is the major glucose transporter in skeletal muscle and adipose tissue, which is under control of insulin. It remains, however, unclear whether cinnamaldehyde plays a regulatory role(s) or not. Objectives: The objective of this study was to investigate the effects of cinnamaldehyde on GLUT4 gene expression. Materials and Methods: This study was an experimental trial. Tests were performed in triplicates. This study examined effects of cinnamaldehyde on Glut4 gene expression in C2C12 skeletal muscle cells by using Real Time PCR. C2C12 myoblasts were cultured in DMEM + 10 % FBS. After differentiation of myoblasts to myotubes, the cells were serum deprived for 5 hours and then treated with 10, 20, or 50 µM of cinnamaldehyde for 1 hour. Results: Our data revealed a significant increase in the expression of Glut4 in cinnamaldehyde treated cells. In addition, GLUT4 mRNA level was increased in a dose dependent manner. Analyses were performed using the SPSS 16 for Windows software. Differences between the groups were determined by one-way ANOVA. Conclusions: These results demonstrate that cinnamaldehyde up regulates the expression of mouse skeletal muscle GLUT4 gene expression. PMID:24719730

  18. Glucose turnover and recycling in colorectal carcinoma.

    PubMed

    Kokal, W A; McCulloch, A; Wright, P D; Johnston, I D

    1983-11-01

    Glucose metabolism is affected by various pathologic states including tumors. In this project, glucose turnover and recycling rates in 11 patients with colorectal carcinoma were measured using a double-labelled 3-3H and 1-14C glucose injection technique. Fasting blood glucose, lactate, pyruvate, alanine, glycerol, 3-hydroxybutyrate, acetoacetate, plasma cortisol, and plasma insulin concentrations were also measured. No patient in the study had a history of diabetes mellitus or endocrine disorders, nor any abnormal liver function tests. The findings demonstrated a significantly elevated glucose turnover rate in patients with Dukes C and D lesions in comparison to patients with Dukes B lesions. Cori recycling rates were not significantly different between Dukes B vs. Dukes C and D patients. There were no differences between Dukes B and Dukes C and D patients in any of the metabolites measured. Furthermore, there were no significant differences in glucose turnover or recycling rates as a function of pre-illness weight loss. These data suggest that, when colorectal carcinoma extends beyond the limits of the bowel wall, glucose metabolism is significantly altered.

  19. Noninvasive glucose sensing by transcutaneous Raman spectroscopy

    PubMed Central

    Shih, Wei-Chuan; Bechtel, Kate L.; Rebec, Mihailo V.

    2015-01-01

    Abstract. We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ∼1.5−2  mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies. PMID:25688542

  20. Exercising Tactically for Taming Postmeal Glucose Surges

    PubMed Central

    Chacko, Elsamma

    2016-01-01

    This review seeks to synthesize data on the timing, intensity, and duration of exercise found scattered over some 39 studies spanning 3+ decades into optimal exercise conditions for controlling postmeal glucose surges. The results show that a light aerobic exercise for 60 min or moderate activity for 20–30 min starting 30 min after meal can efficiently blunt the glucose surge, with minimal risk of hypoglycemia. Exercising at other times could lead to glucose elevation caused by counterregulation. Adding a short bout of resistance exercise of moderate intensity (60%–80%  VO2max) to the aerobic activity, 2 or 3 times a week as recommended by the current guidelines, may also help with the lowering of glucose surges. On the other hand, high-intensity exercise (>80%  VO2max) causes wide glucose fluctuations and its feasibility and efficacy for glucose regulation remain to be ascertained. Promoting the kind of physical activity that best counters postmeal hyperglycemia is crucial because hundreds of millions of diabetes patients living in developing countries and in the pockets of poverty in the West must do without medicines, supplies, and special diets. Physical activity is the one tool they may readily utilize to tame postmeal glucose surges. Exercising in this manner does not violate any of the current guidelines, which encourage exercise any time. PMID:27073714

  1. The human brain produces fructose from glucose

    PubMed Central

    Hwang, Janice J.; Jiang, Lihong; Hamza, Muhammad; Dai, Feng; Cline, Gary; Rothman, Douglas L.; Mason, Graeme; Sherwin, Robert S.

    2017-01-01

    Fructose has been implicated in the pathogenesis of obesity and type 2 diabetes. In contrast to glucose, CNS delivery of fructose in rodents promotes feeding behavior. However, because circulating plasma fructose levels are exceedingly low, it remains unclear to what extent fructose crosses the blood-brain barrier to exert CNS effects. To determine whether fructose can be endogenously generated from glucose via the polyol pathway (glucose → sorbitol → fructose) in human brain, 8 healthy subjects (4 women/4 men; age, 28.8 ± 6.2 years; BMI, 23.4 ± 2.6; HbA1C, 4.9% ± 0.2%) underwent 1H magnetic resonance spectroscopy scanning to measure intracerebral glucose and fructose levels during a 4-hour hyperglycemic clamp (plasma glucose, 220 mg/dl). Using mixed-effects regression model analysis, intracerebral glucose rose significantly over time and differed from baseline at 20 to 230 minutes. Intracerebral fructose levels also rose over time, differing from baseline at 30 to 230 minutes. The changes in intracerebral fructose were related to changes in intracerebral glucose but not to plasma fructose levels. Our findings suggest that the polyol pathway contributes to endogenous CNS production of fructose and that the effects of fructose in the CNS may extend beyond its direct dietary consumption. PMID:28239653

  2. Noninvasive glucose sensing by transcutaneous Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Shih, Wei-Chuan; Bechtel, Kate L.; Rebec, Mihailo V.

    2015-05-01

    We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ˜1.5-2 mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies.

  3. Continuous Glucose Monitoring: Impact on Hypoglycemia.

    PubMed

    van Beers, Cornelis A J; DeVries, J Hans

    2016-11-01

    The necessity of strict glycemic control is unquestionable. However, hypoglycemia remains a major limiting factor in achieving satisfactory glucose control, and evidence is mounting to show that hypoglycemia is not benign. Over the past decade, evidence has consistently shown that real-time continuous glucose monitoring improves glycemic control in terms of lowering glycated hemoglobin levels. However, real-time continuous glucose monitoring has not met the expectations of the diabetes community with regard to hypoglycemia prevention. The earlier trials did not demonstrate any effect on either mild or severe hypoglycemia and the effect of real-time continuous glucose monitoring on nocturnal hypoglycemia was often not reported. However, trials specifically designed to reduce hypoglycemia in patients with a high hypoglycemia risk have demonstrated a reduction in hypoglycemia, suggesting that real-time continuous glucose monitoring can prevent hypoglycemia when it is specifically used for that purpose. Moreover, the newest generation of diabetes technology currently available commercially, namely sensor-augmented pump therapy with a (predictive) low glucose suspend feature, has provided more convincing evidence for hypoglycemia prevention. This article provides an overview of the hypoglycemia outcomes of randomized controlled trials that investigate the effect of real-time continuous glucose monitoring alone or sensor-augmented pump therapy with a (predictive) low glucose suspend feature. Furthermore, several possible explanations are provided why trials have not shown a reduction in severe hypoglycemia. In addition, existing evidence is presented of real-time continuous glucose monitoring in patients with impaired awareness of hypoglycemia who have the highest risk of severe hypoglycemia.

  4. Highly sensitive terahertz sensor for glucose detection

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-Suk; Lee, Dong-Kyu; Lee, Seok; Chung, Youngchul; Seo, Minah

    2015-07-01

    In this report, we present a new type of non-contact detection method for glucose molecule using nano antenna array based bio sensing chip that operates at terahertz frequency range (0.5 - 2.5 THz). Localized and hugely enhanced transmitted terahertz field by nano antenna array in the sensing chip induced enhancement of absorption coefficient of glucose molecule that enables us to detect even very small volume of molecules. Nano antenna based terahertz sensing chip can be expected to offer accurate identification of glucose level as a non-invasive and painless sensing tool with high sensitivity.

  5. Glucose and fructose metabolism in Zymomonas anaerobia

    PubMed Central

    McGill, D. J.; Dawes, E. A.

    1971-01-01

    Isotopic and enzymic evidence indicates that Zymomonas anaerobia ferments glucose via the Entner–Doudoroff pathway. The molar growth yields with glucose (5.89) and fructose (5.0) are lower than those for the related organism Zymomonas mobilis and the observed linear growth suggests that energetically uncoupled growth occurs. A survey of enzymes of carbohydrate metabolism revealed the presence of weak phosphofructokinase and fructose 1,6-diphosphate aldolase activities but phosphoketolase, transketolase and transaldolase were not detected. Fermentation balances for glucose and fructose are reported; acetaldehyde accumulated in both fermentations, to a greater extent with fructose which also yielded glycerol and dihydroxyacetone as minor products. PMID:4259336

  6. Self-powered glucose-responsive micropumps.

    PubMed

    Zhang, Hua; Duan, Wentao; Lu, Mengqian; Zhao, Xi; Shklyaev, Sergey; Liu, Lei; Huang, Tony Jun; Sen, Ayusman

    2014-08-26

    A self-powered polymeric micropump based on boronate chemistry is described. The pump is triggered by the presence of glucose in ambient conditions and induces convective fluid flows, with pumping velocity proportional to the glucose concentration. The pumping is due to buoyancy convection that originates from reaction-associated heat flux, as verified from experiments and finite difference modeling. As predicted, the fluid flow increases with increasing height of the chamber. In addition, pumping velocity is enhanced on replacing glucose with mannitol because of the enhanced exothermicity associated with the reaction of the latter.

  7. Chromatographic Separation of Glucose and Fructose

    NASA Astrophysics Data System (ADS)

    Kuptsevich, Yu E.; Larionov, Oleg G.; Stal'naya, I. D.; Nakhapetyan, L. A.; Pronin, A. Ya

    1987-03-01

    The structures, mutarotation, and the physicochemical properties of glucose and fructose as well as methods for their separation are examined. Their chromatographic separation on cation exchangers in the calcium-form is discussed in detail. A theory of the formation of complexes of carbohydrates with metal cations is described and the mechanism of the separation of glucose and fructose on cation exchangers in the calcium-form is discussed in detail. Factors influencing the chromatographic separation of glucose and fructose on sulphonic acid cation-exchange resins are also considered. The bibliography includes 138 references.

  8. Fetal programming of perivenous glucose uptake reveals a regulatory mechanism governing hepatic glucose output during refeeding.

    PubMed

    Murphy, Helena C; Regan, Gemma; Bogdarina, Irina G; Clark, Adrian J L; Iles, Richard A; Cohen, Robert D; Hitman, Graham A; Berry, Colin L; Coade, Zoe; Petry, Clive J; Burns, Shamus P

    2003-06-01

    Increased hepatic gluconeogenesis maintains glycemia during fasting and has been considered responsible for elevated hepatic glucose output in type 2 diabetes. Glucose derived periportally via gluconeogenesis is partially taken up perivenously in perfused liver but not in adult rats whose mothers were protein-restricted during gestation (MLP rats)-an environmental model of fetal programming of adult glucose intolerance exhibiting diminished perivenous glucokinase (GK) activity. We now show that perivenous glucose uptake rises with increasing glucose concentration (0-8 mmol/l) in control but not MLP liver, indicating that GK is flux-generating. The data demonstrate that acute control of hepatic glucose output is principally achieved by increasing perivenous glucose uptake, with rising glucose concentration during refeeding, rather than by downregulation of gluconeogenesis, which occurs in different hepatocytes. Consistent with these observations, glycogen synthesis in vivo commenced in the perivenous cells during refeeding, MLP livers accumulating less glycogen than controls. GK gene transcription was unchanged in MLP liver, the data supporting a recently proposed posttranscriptional model of GK regulation involving nuclear-cytoplasmic transport. The results are pertinent to impaired regulation of hepatic glucose output in type 2 diabetes, which could arise from diminished GK-mediated glucose uptake rather than increased gluconeogenesis.

  9. Hepatic glucose sensing is required to preserve β cell glucose competence.

    PubMed

    Seyer, Pascal; Vallois, David; Poitry-Yamate, Carole; Schütz, Frédéric; Metref, Salima; Tarussio, David; Maechler, Pierre; Staels, Bart; Lanz, Bernard; Grueter, Rolf; Decaris, Julie; Turner, Scott; da Costa, Anabela; Preitner, Frédéric; Minehira, Kaori; Foretz, Marc; Thorens, Bernard

    2013-04-01

    Liver glucose metabolism plays a central role in glucose homeostasis and may also regulate feeding and energy expenditure. Here we assessed the impact of glucose transporter 2 (Glut2) gene inactivation in adult mouse liver (LG2KO mice). Loss of Glut2 suppressed hepatic glucose uptake but not glucose output. In the fasted state, expression of carbohydrate-responsive element-binding protein (ChREBP) and its glycolytic and lipogenic target genes was abnormally elevated. Feeding, energy expenditure, and insulin sensitivity were identical in LG2KO and control mice. Glucose tolerance was initially normal after Glut2 inactivation, but LG2KO mice exhibited progressive impairment of glucose-stimulated insulin secretion even though β cell mass and insulin content remained normal. Liver transcript profiling revealed a coordinated downregulation of cholesterol biosynthesis genes in LG2KO mice that was associated with reduced hepatic cholesterol in fasted mice and reduced bile acids (BAs) in feces, with a similar trend in plasma. We showed that chronic BAs or farnesoid X receptor (FXR) agonist treatment of primary islets increases glucose-stimulated insulin secretion, an effect not seen in islets from Fxr(-/-) mice. Collectively, our data show that glucose sensing by the liver controls β cell glucose competence and suggest BAs as a potential mechanistic link.

  10. An integrated glucose-insulin model to describe oral glucose tolerance test data in type 2 diabetics.

    PubMed

    Jauslin, Petra M; Silber, Hanna E; Frey, Nicolas; Gieschke, Ronald; Simonsson, Ulrika S H; Jorga, Karin; Karlsson, Mats O

    2007-10-01

    An integrated model for the glucose-insulin system describing oral glucose tolerance test data was developed, extending on a previously introduced model for intravenous glucose provocations. Model extensions comprised the description of glucose absorption by a chain of transit compartments with a mean transit time of 35 minutes, a bioavailability of 80%, and a representation of the incretin effect, expressed as a direct effect of the glucose absorption rate on insulin secretion. The ability of the model to predict the incretin effect was assessed by simulating the observed difference in insulin response following an oral glucose tolerance test compared with an isoglycemic glucose infusion mimicking an oral glucose tolerance test profile. The extension of the integrated glucose-insulin model to gain information from oral glucose tolerance test data considerably expands its range of applications because the oral glucose tolerance test is one of the most common glucose challenge experiments for assessing the efficacy of hypoglycemic agents in clinical drug development.

  11. Lifestyle, glucose regulation and the cognitive effects of glucose load in middle-aged adults.

    PubMed

    Riby, Leigh M; McLaughlin, Jennifer; Riby, Deborah M; Graham, Cheryl

    2008-11-01

    Interventions aimed at improving glucose regulatory mechanisms have been suggested as a possible source of cognitive enhancement in the elderly. In particular, previous research has identified episodic memory as a target for facilitation after either moderate increases in glycaemia (after a glucose drink) or after improvements in glucose regulation. The present study aimed to extend this research by examining the joint effects of glucose ingestion and glucose regulation on cognition. In addition, risk factors associated with the development of poor glucose regulation in middle-aged adults were considered. In a repeated measures design, thirty-three middle-aged adults (aged 35-55 years) performed a battery of memory and non-memory tasks after either 25 g or 50 g glucose or a sweetness matched placebo drink. To assess the impact of individual differences in glucose regulation, blood glucose measurements were taken on four occasions during testing. A lifestyle and diet questionnaire was also administered. Consistent with previous research, episodic memory ability benefited from glucose ingestion when task demands were high. Blood glucose concentration was also found to predict performance across a number of cognitive domains. Interestingly, the risk factors associated with poor glucose regulation were linked to dietary impacts traditionally associated with poor health, e.g. the consumption of high-sugar sweets and drinks. The research replicates earlier work suggesting that task demands are critical to the glucose facilitation effect. Importantly, the data demonstrate clear associations between elevated glycaemia and relatively poor cognitive performance, which may be partly due to the effect of dietary and lifestyle factors.

  12. Myo-inositol inhibits intestinal glucose absorption and promotes muscle glucose uptake: a dual approach study.

    PubMed

    Chukwuma, Chika Ifeanyi; Ibrahim, Mohammed Auwal; Islam, Md Shahidul

    2016-12-01

    The present study investigated the effects of myo-inositol on muscle glucose uptake and intestinal glucose absorption ex vivo as well as in normal and type 2 diabetes model of rats. In ex vivo study, both intestinal glucose absorption and muscle glucose uptake were studied in isolated rat jejunum and psoas muscle respectively in the presence of increasing concentrations (2.5 % to 20 %) of myo-inositol. In the in vivo study, the effect of a single bolus dose (1 g/kg bw) of oral myo-inositol on intestinal glucose absorption, blood glucose, gastric emptying and digesta transit was investigated in normal and type 2 diabetic rats after 1 h of co-administration with 2 g/kg bw glucose, when phenol red was used as a recovery marker. Myo-inositol inhibited intestinal glucose absorption (IC50 = 28.23 ± 6.01 %) and increased muscle glucose uptake, with (GU50 = 2.68 ± 0.75 %) or without (GU50 = 8.61 ± 0.55 %) insulin. Additionally, oral myo-inositol not only inhibited duodenal glucose absorption and reduced blood glucose increase, but also delayed gastric emptying and accelerated digesta transit in both normal and diabetic animals. Results of this study suggest that dietary myo-inositol inhibits intestinal glucose absorption both in ex vivo and in normal or diabetic rats and also promotes muscle glucose uptake in ex vivo condition. Hence, myo-inositol may be further investigated as a possible anti-hyperglycaemic dietary supplement for diabetic foods and food products.

  13. [Artificial pancreas for automated glucose control].

    PubMed

    Blauw, Helga; van Bon, Arianne C; de Vries, J H Hans

    2013-01-01

    Strict glucose control is important for patients with diabetes mellitus in order to prevent complications. However, many patients find it difficult to achieve the recommended HbA1c level. The possibility of hypoglycaemia plays an important role in this. The artificial pancreas automates glucose control, improving glucose levels without increasing hypoglycaemic events. The required insulin dose is calculated and administered on the basis of continuous glucose measurements, taking over a large part of the treatment from the patient. Several research groups are working on making this technique suitable for home use. It is expected that the artificial pancreas will become available in the near future. However, effectiveness and safety will have to be investigated in long-term studies. A large number of insulin-dependent patients with diabetes could be eligible for this treatment.

  14. Sensing of glucose in the gastrointestinal tract.

    PubMed

    Raybould, Helen E

    2007-04-30

    In general, nutrient sensing mechanisms in the intestine are not well understood. Potential sensors include the terminals of extrinsic afferent nerves, enteric nerves, endocrine cells and other epithelial cells including enterocytes and immune cells. This short review will concentrate on the neural pathways that are activated by the presence of glucose in the intestinal lumen and the role of a specialized endocrine cell, the enterochromaffin cell in glucose-sensing and the subsequent activation of extrinsic neural pathways.

  15. Acid hydrolysis of cellulose to yield glucose

    DOEpatents

    Tsao, George T.; Ladisch, Michael R.; Bose, Arindam

    1979-01-01

    A process to yield glucose from cellulose through acid hydrolysis. Cellulose is recovered from cellulosic materials, preferably by pretreating the cellulosic materials by dissolving the cellulosic materials in Cadoxen or a chelating metal caustic swelling solvent and then precipitating the cellulose therefrom. Hydrolysis is accomplished using an acid, preferably dilute sulfuric acid, and the glucose is yielded substantially without side products. Lignin may be removed either before or after hydrolysis.

  16. The Kidney's role in glucose balance following partial hepatectomy.

    PubMed

    Jones, C E; Koshibu, K; DeCambre, M; Gerich, J E; Bessey, P Q; Krusch, D A

    1998-10-01

    It has long been believed that the liver is the major contributor to glucose balance during fasting and stressful situations. Recently, investigators have implicated the kidney as having a significant contribution to systemic glucose appearance. We studied the relative contributions of the kidney and liver to glucose homeostasis in fasted nonoperated, sham-operated, and 70% hepatectomized rats. Systemic glucose appearance, renal glucose release and uptake, and hepatic glucose release were determined by glucose balance and isotopic dilution techniques. Systemic glucose appearance remained unchanged following hepatectomy. There was a significant output of glucose by the kidney in all groups, accounting for >50% of total glucose appearance. Despite the kidney's appreciable contribution to circulating glucose in the postabsorptive state, renal glucose release was not increased in the hepatectomized rats compared to controls. Total glucose appearance was maintained following hepatectomy by an increase in hepatic glucogenesis. There was a significant increase in the rate of hepatic glucose release from resected rats when normalized to gram of remaining liver (P < 0.001). Despite the substantial amount of renal glucose output in the postabsorptive state, preservation of glucose balance following 70% hepatectomy is accomplished by adaptation in hepatic glucose output.

  17. Effects of fasting on plasma glucose and prolonged tracer measurement of hepatic glucose output in NIDDM

    SciTech Connect

    Glauber, H.; Wallace, P.; Brechtel, G.

    1987-10-01

    We studied the measurement of hepatic glucose output (HGO) with prolonged (3-/sup 3/H)glucose infusion in 14 patients with non-insulin-dependent diabetes mellitus (NIDDM). Over the course of 10.5 h, plasma glucose concentration fell with fasting by one-third, from 234 +/- 21 to 152 +/- 12 mg/dl, and HGO fell from 2.35 +/- 0.18 to 1.36 +/- 0.07 mg . kg-1 . min-1 (P less than .001). In the basal state, HGO and glucose were significantly correlated (r = 0.68, P = .03), and in individual patients, HGO and glucose were closely correlated as both fell with fasting (mean r = 0.79, P less than .01). Plasma (3-/sup 3/H)glucose radioactivity approached a steady state only 5-6 h after initiation of the primed continuous infusion, and a 20% overestimate of HGO was demonstrated by not allowing sufficient time for tracer labeling of the glucose pool. Assumption of steady-state instead of non-steady-state kinetics in using Steele's equations to calculate glucose turnover resulted in a 9-24% overestimate of HGO. Stimulation of glycogenolysis by glucagon injection demonstrated no incorporation of (3-/sup 3/H)glucose in hepatic glycogen during the prolonged tracer infusion. In a separate study, plasma glucose was maintained at fasting levels (207 +/- 17 mg/dl) for 8 h with the glucose-clamp technique. Total glucose turnover rates remained constant during this prolonged tracer infusion. However, HGO fell to 30% of the basal value simply by maintaining fasting hyperglycemia in the presence of basal insulin levels.

  18. pH-insensitive glucose indicators.

    PubMed

    Garrett, Jared R; Wu, Xinxin; Jin, Sha; Ye, Kaiming

    2008-01-01

    There is an urgent need for developing a biosensor that can real-time and noninvasively determine glucose concentration within living cells. In our previous study, we have engineered a glucose indicator protein (GIP) that can provide continuous glucose monitoring through a conformation change-induced Förster resonance-energy transfer measurement. Because of the pH-sensitivity of the fluorescent proteins used in the GIP construction, the GIP made from these fluorescent proteins is less tolerant to a pH change, especially to the acidic environment. It has been well documented that intracellular pH does not always remain the same, and it fluctuates in metabolism and other cellular activities and also differs between cellular compartments. To address these issues, we developed a GIP that can tolerate to pH change. This GIP was constructed by flanking a glucose binding protein with a cyan fluorescent protein and a pH-insensitive yellow fluorescent protein. Our experimental results indicated that the new GIP is more tolerant to pH change. The glucose response of this new GIP kept almost unchanged from pH 7.3 to 5.3, suggesting its capability of tolerating to acidic environment. This capability is desirable for intracellular glucose measurement.

  19. Hypoxia causes glucose intolerance in humans.

    PubMed

    Oltmanns, Kerstin M; Gehring, Hartmut; Rudolf, Sebastian; Schultes, Bernd; Rook, Stefanie; Schweiger, Ulrich; Born, Jan; Fehm, Horst L; Peters, Achim

    2004-06-01

    Hypoxic respiratory diseases are frequently accompanied by glucose intolerance. We examined whether hypoxia is a cause of glucose intolerance in healthy subjects. In a double-blind within-subject crossover design, hypoxic versus normoxic conditions were induced in 14 healthy men for 30 minutes by decreasing oxygen saturation to 75% (versus 96% in control subjects) under the conditions of a euglycemic clamp. The rate of dextrose infusion needed to maintain stable blood glucose levels was monitored. Neurohormonal stress response was evaluated by measuring catecholamine and cortisol concentrations as well as cardiovascular parameters, and symptoms of anxiety. To differentiate between the effects of stress hormonal response, and hypoxia itself, on glucose intolerance, we performed hypoglycemic clamps as a nonspecific control. We found a significant decrease in dextrose infusion rate over a period of 150 minutes after the start of hypoxia (p < 0.01). Hypoxia also increased plasma epinephrine concentration (p < 0.01), heart rate (p < 0.01), and symptoms of anxiety (p < 0.05), whereas the other parameters remained unaffected. Glucose intolerance was closely comparable between hypoxic and hypoglycemic conditions (p < 0.9) despite clear differences in stress hormonal responses. Hypoxia acutely causes glucose intolerance. One of the factors mediating this effect could be an elevated release of epinephrine.

  20. Glucose determination with fiber optic spectrometers

    NASA Astrophysics Data System (ADS)

    Starke, Eva; Kemper, Ulf; Barschdorff, Dieter

    1999-05-01

    Noninvasive blood glucose monitoring is the aim of research activities concerning the detection of small glucose concentrations dissolved in water and blood plasma. One approach for these measurements is the exploitation of absorption bands in the near infrared. However, the strong absorption of water represents a major difficulty. Transmission measurements of glucose dissolved in water and in blood plasma in the spectral region around 1600 nm with one- beam spectrometers and a FT-IR spectrometer are discussed. The evaluation of the data is carried out using a two-layer Lambert-Beer model and neural networks. In order to reduce the dimensions of a potential measuring device, an integrated acousto-optic tunable filter (AOTF) with an Erbium doped fiber amplifier as a radiation source is used. The fiber optic components are examined concerning their suitability. The smallest concentrations of glucose dissolved in water that can be separated are approximately 50 mg/dl. In the range of 50 mg/dl to 1000 mg/dl a correlation coefficient of 0.98 between real and estimated glucose concentrations is achieved using neural networks. In blood plasma so far glucose concentrations of about 100 mg/dl can be distinguished with good accuracy.

  1. Inhibition of hexose transport by glucose in a glucose-6-phosphate isomerase mutant of Saccharomyces cerevisiae.

    PubMed

    Alonso, A; Pascual, C; Romay, C; Herrera, L; Kotyk, A

    1989-01-01

    The rate of hexose transport was approximately 60% lower for both the high- and the low-affinity components of hexose uptake when a glucose-6-phosphate isomerase mutant of Saccharomyces cerevisiae was preincubated with glucose, as compared with preincubation with water. Similarly the Jmax value of the high-affinity system of the mutant was 25-35% of the corresponding Jmax value for normal cells incubated with glucose. Accumulation of glucose 6-phosphate or of some other metabolite, such as fructose 6-phosphate or trehalose, may be responsible for this striking inhibition.

  2. Glucose as substrate and signal in priming: Results from experiments with non-metabolizable glucose analogues

    NASA Astrophysics Data System (ADS)

    Mason-Jones, Kyle; Kuzyakov, Yakov

    2016-04-01

    Priming of soil organic matter remains the subject of intense research, but a mechanistic explanation of the phenomenon remains to be demonstrated. This is largely due to the multiple effects of easily available carbon on the soil microbial community, and the challenge of separating these influences from one another. Several glucose analogues can be taken up by microbial glucose transporters and have similar regulatory effects on metabolism. These substances are, however, not easily catabolized by the common glycolytic pathway, limiting their energy value. Therefore, they can be used to distinguish between the action of glucose as a metabolic signal, and its influence as an energy source. We incubated an agricultural Haplic Luvisol under controlled conditions for 24 days after addition of: 1) glucose, 2) 3-O-methyl-glucose, 3) α-methylglucoside or 4) 2-deoxyglucose, at three concentration levels, along with a control treatment of water addition. CO2 efflux from soil was monitored by trapping evolved CO2 in NaOH and back-titration with HCl. On the first day after amendment, CO2 efflux from soil increased strongly for glucose and much less for the analogues, relative to the control. Only glucose caused a peak in efflux within the first two days. Peak mineralization of 2-deoxyglucose and α-methylglucoside was delayed until the third day, while CO2 from 3-O-methyl-glucose increased gradually, with a peak delayed by approximately a week. For glucose, the immediate increase in respiration was strongly dependent on the amount of glucose added, but this was not the case for the analogues, indicating that the catabolic potential for these substances was saturated. This is consistent with only a small part of the microbial community being capable of utilizing these carbon sources. In a subsequent experiment, 14C-labelled glucose or 14C-labelled 3-O-methyl-glucose were added to the same soil, enabling quantification of the priming effect. For 3-O-methyl-glucose, priming was

  3. Fetal glucose uptake and utilization as functions of maternal glucose concentration.

    PubMed

    Hay, W W; Sparks, J W; Wilkening, R B; Battaglia, F C; Meschia, G

    1984-03-01

    Seventeen studies were performed in 12 pregnant sheep to examine the relationship among simultaneously measured glucose uptake via the umbilical circulation, fetal glucose utilization (mg X min-1 X kg-1), and maternal arterial glucose (Gm, mg/dl). Fetal glucose utilization was measured by means of tracer glucose infused into the fetus or both mother and fetus. By fasting the ewe, Gm was varied in the 62-22 range. A decrease in Gm was accompanied by a significant (P less than 0.001) decrease in umbilical uptake (uptake = 0.09 Gm - 0.96, r = 0.82) and in fetal utilization, measured either by [U-14C]glucose (utilization = 0.062 Gm + 0.91, r = 0.90) or [6-3H]glucose (utilization = 0.065 Gm + 0.51, r = 0.91). At uptake greater than 3 mg X min-1 X kg-1, utilization and uptake were not significantly different. At lower uptakes, utilization did not decline as much as uptake. The results demonstrate that maternal fasting decreases both the umbilical uptake and the fetal utilization of glucose and suggest that fetal glucogenesis increases when the availability of exogenous glucose is markedly reduced.

  4. Effect of glucose supplementation on appetite and the pyloric motor response to intraduodenal glucose and lipid.

    PubMed

    Andrews, J M; Doran, S; Hebbard, G S; Rassias, G; Sun, W M; Horowitz, M

    1998-04-01

    The effects of different macronutrients on appetite and pyloric motility and the impact of short-term dietary glucose supplementation on these responses were evaluated. Ten males (aged 19-38 yr) received isocaloric (2.9 kcal/min) intraduodenal infusions of glucose and lipid while antropyloroduodenal motility and appetite were assessed by manometry and visual analog scales, respectively. Effects of each intraduodenal nutrient on appetite and motility were evaluated before and after 7 days of dietary supplementation with glucose (400 g daily). Initially, both nutrients caused a similar rise in pyloric tone, but intraduodenal lipid was a more potent stimulus of phasic pyloric motility (P = 0.05) and suppressed appetite more (P = 0.013) than intraduodenal glucose. After dietary glucose supplementation, the increase in pyloric tone during intraduodenal glucose was attenuated. Although intraduodenal lipid remained a more potent stimulant of phasic pyloric motility (P = 0.016), it no longer decreased appetite. We conclude that in healthy young males 1) intraduodenal infusion of lipid is a more potent stimulus of phasic pyloric motility and suppresses appetite more than intraduodenal glucose and 2) dietary glucose supplementation alters both the appetite suppressant effect of intraduodenal lipid and the pyloric motor response to intraduodenal glucose infusion.

  5. Noninvasive Continuous Monitoring of Tear Glucose Using Glucose-Sensing Contact Lenses.

    PubMed

    Ascaso, Francisco J; Huerva, Valentín

    2016-04-01

    : The incidence of diabetes mellitus is dramatically increasing in the developed countries. Tight control of blood glucose concentration is crucial to diabetic patients to prevent microvascular complications. Self-monitoring of blood glucose is widely used for controlling blood glucose levels and usually performed by an invasive test using a portable glucometer. Many technologies have been developed over the past decades with the purpose of obtaining a continuous physiological glycemic monitoring. A contact lens is the ideal vehicle for continuous tear glucose monitoring of glucose concentration in tear film. There are several research groups that are working in the development of contact lenses with embedded biosensors for continuously and noninvasively monitoring tear glucose levels. Although numerous aspects must be improved, contact lens technology is one step closer to helping diabetic subjects better manage their condition, and these contact lenses will be able to measure the level of glucose in the wearer's tears and communicate the information to a mobile phone or computer. This article reviews studies on ocular glucose and its monitoring methods as well as the attempts to continuously monitor the concentration of tear glucose by using contact lens-based sensors.

  6. Wireless glucose monitoring watch enabled by an implantable self-sustaining glucose sensor system

    NASA Astrophysics Data System (ADS)

    Rai, Pratyush; Varadan, Vijay K.

    2012-10-01

    Implantable glucose sensors can measure real time blood glucose as compared to conventional techniques involving drawing blood samples and in-vitro processing. An implantable sensor requires energy source for operation with wire inout provision for power and sending signals. Implants capable of generation-transmission of sensory signals, with minimal or no power requirement, can solve this problem. An implantable nanosensor design has been presented here, which can passively detect glucose concentration in blood stream and transmit data to a wearable receiver-recorder system or a watch. The glucose sensitive component is a redox pair of electrodes that generates voltage proportional to glucose concentration. The bio-electrode, made of carbon nanotubes-enzyme nanocluster, has been investigated because of the large surface area for taping electrical signals. This glucose sensor can charge a capacitor, which can be a part of a LCR resonance/inductive coupling based radio frequency (RF) sensor telemetry. Such a system can measure change in glucose concentration by the induced frequency shift in the LCR circuit. A simultaneous power transmission and signal transmission can be achieved by employing two separate LCR oscillating loops, one for each operation. The corresponding coupling LCR circuits can be housed in the wearable receiving watch unit. The data logged in this glucose monitoring watch can be instrumental in managing blood glucose as trigger for an insulin dispensing payload worn on person or implanted.

  7. Impaired glucose metabolism in hypertensive patients.

    PubMed

    Fragachan, F; Perez-Acuña, F; Monsalve, P; Sanabria, A

    1990-01-01

    We have studied glucose tolerance under carefully controlled conditions in 79 patients with arterial hypertension. The results show that, in patients with arterial hypertension but without clinical diabetes mellitus, the glucose tolerance was abnormal in 77.3% and normal in 22.3%. The corresponding figure in the control group of normotensive subjects was 0%. In each test the responses to glucose administration were analyzed by plotting the logarithm of the blood glucose concentration against time. For the points between 60 and 120 min, corresponding to the periods following glucose administration, a linear relationship was obtained and showed a decline at an exponential rate, as noted by other observers. An estimate of the volume of distribution of glucose was obtained as follows. Values observed in hypertensives with a pathological percent fall in blood glucose per minute (Kg) were 29.8 +/- 12.0 (mean +/- SD) liters and those in normal subjects with normal Kg values had a mean of 14.35 +/- 2.98, the difference being highly significant (p less than 0.0001). The results of the theoretical glucose concentration are also presented. Those obtained from subjects with normal Kg values (359.0 +/- 58.4 mg/dl) are significantly higher than in subjects with pathological Kg values (257.6 +/- 51.3 mg/dl; p less than 0.0001). All patients with either pathological or normal Kg values had normal glucose concentration levels, fasting blood sugar and no glucose in the urine specimen. The difference between pathological Kg values (107.0 +/- 25.8 mg/dl) and normal Kg values (90.6 +/- 13.0 mg/dl) was not found to be statistically different (p greater than 0.05). The distribution and means of glucose half time in controls with normal Kg values and hypertensives with pathological Kg values were: 63.5 +/- 11.5 and 137.8 +/- 48.1 min, respectively. The difference between normal and pathological Kg values being statistically significant at a confidence level above 99.5%. We also studied

  8. The effect of short-term dietary supplementation with glucose on gastric emptying of glucose and fructose and oral glucose tolerance in normal subjects.

    PubMed

    Horowitz, M; Cunningham, K M; Wishart, J M; Jones, K L; Read, N W

    1996-04-01

    Recent observations indicate that gastric emptying may be influenced by patterns of previous nutrient intake. The aims of this study were to determine the effects of a high glucose diet on gastric emptying of glucose and fructose, and the impact of any changes in gastric emptying on plasma concentrations of glucose, insulin and gastric inhibitory polypeptide in response to glucose and fructose loads. Gastric emptying of glucose and fructose (both 75 g dissolved in 350 ml water) were measured in seven normal volunteers on separate days while each was on a "standard' diet and an identical diet supplemented with 440 g/day of glucose for 4-7 days. Venous blood samples for measurement of plasma glucose, insulin and gastric inhibitory polypeptide levels were taken immediately before and for 180 min after ingestion of glucose and fructose loads. Dietary glucose supplementation accelerated gastric emptying of glucose (50% emptying time 82 +/- 8 vs 106 +/- 10 min, p = 0.004) and fructose (73 +/- 9 vs 106 +/- 9 min, p = 0.001). After ingestion of glucose, plasma concentrations of insulin (p < 0.05) and gastric inhibitory polypeptide (p < 0.05) were higher during the glucose-supplemented diet. In contrast, plasma glucose concentrations at 60 min and 75 min were lower (p < 0.05) on the glucose-supplemented diet. We conclude that short-term supplementation of the diet with glucose accelerates gastric emptying of glucose and fructose, presumably as a result of reduced feedback inhibition of gastric emptying from small intestinal luminal receptors. More rapid gastric emptying of glucose has a significant impact on glucose tolerance.

  9. 21 CFR 862.1340 - Urinary glucose (nonquantitative) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Urinary glucose (nonquantitative) test system. 862... Test Systems § 862.1340 Urinary glucose (nonquantitative) test system. (a) Identification. A urinary glucose (nonquantitative) test system is a device intended to measure glucosuria (glucose in...

  10. Microneedle electrodes toward an amperometric glucose-sensing smart patch.

    PubMed

    Invernale, Michael A; Tang, Benjamin C; York, Royce L; Le, Long; Hou, David Yupeng; Anderson, Daniel G

    2014-03-01

    Here, efforts toward the development of a microneedle-based glucose sensor or "smart patch" for intradermal glucose sensing are described. Metallic microneedle array electrodes, conducting polymers, and glucose oxidase form the sensor platform. This work represents the first steps toward the development of painless, transdermal-sensing devices for continuous glucose monitoring.

  11. Sodium salicylate restores the impaired insulin response to glucose and improves glucose tolerance in heroin addicts.

    PubMed

    Giugliano, D; Quatraro, A; Consoli, G; Stante, A; Simeone, V; Ceriello, A; Paolisso, G; Torella, R

    1987-01-01

    Plasma glucose, insulin, C-peptide, glucagon and growth hormone responses to intravenous glucose were evaluated in 10 heroin addicts in the basal state and during an infusion of sodium salicylate, an inhibitor of endogenous prostaglandin synthesis. Ten normal subjects, matched for age, sex and weight served as controls. In the basal state, the heroin addicts had markedly reduced insulin responses to intravenous glucose and low glucose disappearance rates (p less than 0.01 vs controls). The infusion of sodium salicylate caused a striking increase of the acute insulin response to intravenous glucose (from 14.5 +/- 4 microU/ml to 88 +/- 11 microU/ml, p less than 0.001) and restored to normal the reduced glucose tolerance (KG from 1.10 +/- 0.1% min-1 to 2.04 +/- 0.19% min-1). Hypoglycemic values were found in all addicts at the end of the test during salicylate infusion. Indomethacin pretreatment in five additional addicts also caused normalization of the impaired insulin responses to the intravenous glucose challenge and restored to normal the reduced glucose disappearance rate. Plasma glucagon and growth hormone levels were normally suppressed by glucose in addicts in basal conditions; sodium salicylate infusion completely overturned these hormonal responses which became positive in the first 15 min following the glucose challenge. These results demonstrate that the two prostaglandin synthesis inhibitors can restore the impaired B-cell response to glucose in heroin addicts to normal, indicating that this response is not lost but is inhibited by heroin itself or by other substances, perhaps by the endogenous prostaglandins.

  12. Simultaneous uptake of galactose and glucose by Azotobacter vinelandii.

    PubMed

    Wong, T Y; Murdock, C A; Concannon, S P; Lockey, T D

    1991-01-01

    Azotobacter vinelandii growing on galactosides induced two distinct permeases for glucose and galactose. The apparent Vmax and Km of the galactose permease were 16 nmol galactose/min per 10(10) cells and 0.5 mM, respectively. The apparent Vmax and Km of the glucose permease were 7.8 nmol glucose/min per 10(10) cells and 0.04 mM, respectively. Excess glucose had no effect on the galactose uptake. However, excess galactose inhibited glucose transport. The galactosides-induced glucose permease also exhibited different uptake kinetics from that induced by glucose.

  13. Effects of iriflophenone 3-C-β-glucoside on fasting blood glucose level and glucose uptake

    PubMed Central

    Pranakhon, Ratree; Aromdee, Chantana; Pannangpetch, Patchareewan

    2015-01-01

    Background: One of the biological activities of agar wood (Aquilaria sinensis Lour., Thymelaeaceae), is anti-hyperglycemic activity. The methanolic extract (ME) was proven to possess the fasting blood glucose activity in rat and glucose uptake transportation by rat adipocytes. Objective: To determine the decreasing fasting blood glucose level of constituents affordable for in vivo test. If the test was positive, the mechanism which is positive to the ME, glucose transportation, will be performed. Materials and Methods: The ME was separated by column chromatography and identified by spectroscopic methods. Mice was used as an animal model (in vivo), and rat adipocytes were used for the glucose transportation activity (in vitro). Result: Iriflophenone 3-C-β-glucoside (IPG) was the main constituent, 3.17%, and tested for the activities. Insulin and the ME were used as positive controls. The ME, IPG and insulin lowered blood glucose levels by 40.3, 46.4 and 41.5%, respectively, and enhanced glucose uptake by 152, 153, and 183%, respectively. Conclusion: These findings suggest that IPG is active in lowering fasting blood glucose with potency comparable to that of insulin. PMID:25709215

  14. Multiphasic Absorption of Glucose and 3-O-Methyl Glucose by Aged Potato Slices 1

    PubMed Central

    Linask, Juri; Laties, George G.

    1973-01-01

    The isotherm for glucose absorption by aged potato (Solanum tuberosum var. Russet Burbank) discs shows four distinct phases in the concentration ranges 1.0 to 75 μm, 75 μm to 1.5 mm, 1.5 to 15 mm, and 15 to 100 mm, respectively. Each segment of the multiphasic isotherm, when plotted reciprocally by the method of Lineweaver and Burk or of Hofstee, without regard for uptake in earlier phases, indicates absorption rate to be a hyperbolic function of concentration. The observations suggest that glucose uptake is carrier-mediated, and that the transport barrier undergoes a series of all-or-none transformations at critical external concentrations, yielding successive new and higher values for the parameters Km and Vmax 3-O-Methyl glucose, a nonmetabolizable analogue of glucose, shows the same multiphasic absorption isotherm, with Km values essentially similar to those for glucose uptake, and Vmax values somewhat lower than those for glucose absorption. Whereas the first three phases of the absorption isotherm are taken to reflect passage across the plasma membrane, the fourth phase may reflect kinetics of glucose or 3-O-methyl glucose transport to the vacuole. PMID:16658317

  15. Determination of Glucose Concentration in Yeast Culture Medium

    NASA Astrophysics Data System (ADS)

    Hara, Seiichi; Kishimoto, Tomokazu; Muraji, Masafumi; Tsujimoto, Hiroaki; Azuma, Masayuki; Ooshima, Hiroshi

    The present paper describes a sensor for measuring the glucose concentration of yeast culture medium. The sensor determines glucose concentration by measuring the yield of hydrogen peroxide produced by glucose oxidase, which is monitored as luminescence using photomultiplier. The present sensor is able to measure low glucose concentration in media in which yeast cells keep respiration state. We herein describe the system and the characteristics of the glucose sensor.

  16. Studies on Electrical behavior of Glucose using Impedance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Juansah, Jajang; Yulianti, Wina

    2016-01-01

    In this work we report the electrical characteristics of glucose at different frequencies. We show the correlation between electrical properties (impedance, reactance, resistance and conductance) of glucose and glucose concentration. Electrical property measurements on glucose solution were performed in order to formulate the correlation. The measurements were conducted for frequencies between 50 Hz and 1 MHz. From the measurements, we developed a single-pole Cole-Cole graph as a function of glucose concentration.

  17. Characterization of the intravenous glucose tolerance test and the combined glucose-insulin test in donkeys.

    PubMed

    Mendoza, F J; Aguilera-Aguilera, R; Gonzalez-De Cara, C A; Toribio, R E; Estepa, J C; Perez-Ecija, A

    2015-12-01

    Glucose-insulin dynamic challenges such as the intravenous glucose tolerance test (IVGTT) and combined glucose-insulin test (CGIT) have not been described in donkeys. The objectives of this study were (1) to characterize the IVGTT and CGIT in healthy adult donkeys, and (2) to establish normal glucose-insulin proxies. Sixteen donkeys were used and body morphometric variables obtained each. For the IVGTT, glucose (300 mg/kg) was given IV. For the CGIT, glucose (150 mg/kg) followed by recombinant insulin (0.1 IU/kg) were administered IV. Blood samples for glucose and insulin determinations were collected over 300 min. In the IVGTT the positive phase lasted 160.9 ± 13.3 min, glucose concentration peaked at 323.1 ± 9.2 mg/dL and declined at a rate of 1.28 ± 0.15 mg/dL/min. The glucose area under the curve (AUC) was 21.4 ± 1.9 × 10(3) mg/dL/min and the insulin AUC was 7.2 ± 0.9 × 10(3) µIU/mL/min. The positive phase of the CGIT curve lasted 44 ± 3 min, with a glucose clearance rate of 2.01 ± 0.18 mg/dL/min. The negative phase lasted 255.9 ± 3 min, decreasing glucose concentration at rate of -0.63 ± 0.06 mg/dL/min, and reaching a nadir (33.1 ± 3.6 mg/dL) at 118.3 ± 6.3 min. The glucose and insulin AUC values were 15.2 ± 0.9 × 10(3) mg/dL/min and 13.2 ± 0.9 × 10(3) µIU/mL/min. This is the first study characterizing CGIT and IVGTT, and glucose-insulin proxies in healthy adult donkeys. Distinct glucose dynamics, when compared with horses, support the use of species-specific protocols to assess endocrine function.

  18. Glucose metabolism in fish: a review.

    PubMed

    Polakof, Sergio; Panserat, Stéphane; Soengas, José L; Moon, Thomas W

    2012-12-01

    Teleost fishes represent a highly diverse group consisting of more than 20,000 species living across all aquatic environments. This group has significant economical, societal and environmental impacts, yet research efforts have concentrated primarily on salmonid and cyprinid species. This review examines carbohydrate/glucose metabolism and its regulation in these model species including the role of hormones and diet. Over the past decade, molecular tools have been used to address some of the downstream components of these processes and these are incorporated to better understand the roles played by carbohydrates and their regulatory paths. Glucose metabolism remains a contentious area as many fish species are traditionally considered glucose intolerant and, therefore, one might expect that the use and storage of glucose would be considered of minor importance. However, the actual picture is not so clear since the apparent intolerance of fish to carbohydrates is not evident in herbivorous and omnivorous species and even in carnivorous species, glucose is important for specific tissues and/or for specific activities. Thus, our aim is to up-date carbohydrate metabolism in fish, placing it to the context of these new experimental tools and its relationship to dietary intake. Finally, we suggest that new research directions ultimately will lead to a better understanding of these processes.

  19. Hypothalamic NUCKS regulates peripheral glucose homoeostasis.

    PubMed

    Qiu, Beiying; Shi, Xiaohe; Zhou, Qiling; Chen, Hui Shan; Lim, Joy; Han, Weiping; Tergaonkar, Vinay

    2015-08-01

    Nuclear ubiquitous casein and cyclin-dependent kinase substrate (NUCKS) is highly expressed in the brain and peripheral metabolic organs, and regulates transcription of a number of genes involved in insulin signalling. Whole-body depletion of NUCKS (NKO) in mice leads to obesity, glucose intolerance and insulin resistance. However, a tissue-specific contribution of NUCKS to the observed phenotypes remains unknown. Considering the pivotal roles of insulin signalling in the brain, especially in the hypothalamus, we examined the functions of hypothalamic NUCKS in the regulation of peripheral glucose metabolism. Insulin signalling in the hypothalamus was impaired in the NKO mice when insulin was delivered through intracerebroventricular injection. To validate the hypothalamic specificity, we crossed transgenic mice expressing Cre-recombinase under the Nkx2.1 promoter with floxed NUCKS mice to generate mice with hypothalamus-specific deletion of NUCKS (HNKO). We fed the HNKO and littermate control mice with a normal chow diet (NCD) and a high-fat diet (HFD), and assessed glucose tolerance, insulin tolerance and metabolic parameters. HNKO mice showed mild glucose intolerance under an NCD, but exacerbated obesity and insulin resistance phenotypes under an HFD. In addition, NUCKS regulated levels of insulin receptor in the brain. Unlike HNKO mice, mice with immune-cell-specific deletion of NUCKS (VNKO) did not develop obesity or insulin-resistant phenotypes under an HFD. These studies indicate that hypothalamic NUCKS plays an essential role in regulating glucose homoeostasis and insulin signalling in vivo.

  20. Statins impair glucose uptake in tumor cells.

    PubMed

    Malenda, Agata; Skrobanska, Anna; Issat, Tadeusz; Winiarska, Magdalena; Bil, Jacek; Oleszczak, Bozenna; Sinski, Maciej; Firczuk, Małgorzata; Bujnicki, Janusz M; Chlebowska, Justyna; Staruch, Adam D; Glodkowska-Mrowka, Eliza; Kunikowska, Jolanta; Krolicki, Leszek; Szablewski, Leszek; Gaciong, Zbigniew; Koziak, Katarzyna; Jakobisiak, Marek; Golab, Jakub; Nowis, Dominika A

    2012-04-01

    Statins, HMG-CoA reductase inhibitors, are used in the prevention and treatment of cardiovascular diseases owing to their lipid-lowering effects. Previous studies revealed that, by modulating membrane cholesterol content, statins could induce conformational changes in cluster of differentiation 20 (CD20) tetraspanin. The aim of the presented study was to investigate the influence of statins on glucose transporter 1 (GLUT1)-mediated glucose uptake in tumor cells. We observed a significant concentration- and time-dependent decrease in glucose analogs' uptake in several tumor cell lines incubated with statins. This effect was reversible with restitution of cholesterol synthesis pathway with mevalonic acid as well as with supplementation of plasma membrane with exogenous cholesterol. Statins did not change overall GLUT1 expression at neither transcriptional nor protein levels. An exploratory clinical trial revealed that statin treatment decreased glucose uptake in peripheral blood leukocytes and lowered (18)F-fluorodeoxyglucose ((18)F-FDG) uptake by tumor masses in a mantle cell lymphoma patient. A bioinformatics analysis was used to predict the structure of human GLUT1 and to identify putative cholesterol-binding motifs in its juxtamembrane fragment. Altogether, the influence of statins on glucose uptake seems to be of clinical significance. By inhibiting (18)F-FDG uptake, statins can negatively affect the sensitivity of positron emission tomography, a diagnostic procedure frequently used in oncology.

  1. Nanomaterial-mediated Biosensors for Monitoring Glucose

    PubMed Central

    Taguchi, Masashige; Ptitsyn, Andre; McLamore, Eric S.

    2014-01-01

    Real-time monitoring of physiological glucose transport is crucial for gaining new understanding of diabetes. Many techniques and equipment currently exist for measuring glucose, but these techniques are limited by complexity of the measurement, requirement of bulky equipment, and low temporal/spatial resolution. The development of various types of biosensors (eg, electrochemical, optical sensors) for laboratory and/or clinical applications will provide new insights into the cause(s) and possible treatments of diabetes. State-of-the-art biosensors are improved by incorporating catalytic nanomaterials such as carbon nanotubes, graphene, electrospun nanofibers, and quantum dots. These nanomaterials greatly enhance biosensor performance, namely sensitivity, response time, and limit of detection. A wide range of new biosensors that incorporate nanomaterials such as lab-on-chip and nanosensor devices are currently being developed for in vivo and in vitro glucose sensing. These real-time monitoring tools represent a powerful diagnostic and monitoring tool for measuring glucose in diabetes research and point of care diagnostics. However, concerns over the possible toxicity of some nanomaterials limit the application of these devices for in vivo sensing. This review provides a general overview of the state of the art in nanomaterial-mediated biosensors for in vivo and in vitro glucose sensing, and discusses some of the challenges associated with nanomaterial toxicity. PMID:24876594

  2. Glucose control during labor and delivery.

    PubMed

    Ryan, Edmond A; Al-Agha, Rany

    2014-01-01

    Neonatal hypoglycemia is an important consequence for the infant of the mother with diabetes. We have reviewed 24 published papers of various protocols for control of glucose in pregnant diabetic women during labor and delivery including our own published work. A relationship of maternal glucose during labor and neonatal hypoglycemia was sought in 19 of these studies. A significant inverse relationship was found in 10 reports with 3 others showing a similar trend. In all but 1 of these 13 studies the participants had pregestational diabetes. Three of the 6 studies not reporting an inverse relationship involved women with GDM. From this review it appears that the maternal glucose should be maintained between 4.0 and 6.0-7.0 mmol/L during labor. Most women with gestational diabetes, especially if they require <1.0 units/kg/d of insulin, can simply be monitored without intravenous insulin. Our own results demonstrate that a target glucose of 4.0-6.0 mmol/L can be used safely and results in a low rate of neonatal hypoglycemia using an iterative glucose insulin infusion protocol for women with pregestational diabetes and when needed for women with gestational diabetes.

  3. FOXN3 regulates hepatic glucose utilization

    PubMed Central

    Karanth, Santhosh; Zinkhan, Erin K.; Hill, Jonathon T.; Yost, H. Joseph; Schlegel, Amnon

    2016-01-01

    SUMMARY A SNP (rs8004664) in the first intron of the FOXN3 gene is associated with human fasting blood glucose. We find that carriers of the risk allele have higher hepatic expression of the transcriptional repressor FOXN3. Rat Foxn3 protein and zebrafish foxn3 transcripts are downregulated during fasting, a process recapitulated in human HepG2 hepatoma cells. Transgenic overexpression of zebrafish foxn3 or human FOXN3 increases zebrafish hepatic gluconeogenic gene expression, whole-larval free glucose, and adult fasting blood glucose, and also decreases expression of glycolytic genes. Hepatic FOXN3 overexpression suppresses expression of mycb, whose ortholog MYC is known to directly stimulate expression of glucose-utilization enzymes. Carriers of the rs8004664 risk allele have decreased MYC transcript abundance. Human FOXN3 binds DNA sequences in the human FOXN3 and zebrafish mycb loci. We conclude that the rs8004664 risk allele drives excessive expression of FOXN3 during fasting and that FOXN3 regulates fasting blood glucose. PMID:27292639

  4. Glucose transporter type1 (GLUT-1) deficiency.

    PubMed

    Gordon, Neil; Newton, Richard W

    2003-10-01

    Glucose transporter type1 (GLUT-1) deficiency may be rare, but it is a preventable cause of severe learning difficulties; and therefore there is an urgency in making an early diagnosis. Suspicions must be roused when intractable seizures occur in infancy. These may be associated with acquired microcephaly and developmental delay. The finding of low glucose sugar levels in the cerebrospinal fluid, but not in the blood will identify the condition. The gene encoding the GLUT-1 protein is located on the short arm of chromosome 1, and inheritance is by a dominant trait. Patients with this syndrome can have heterozygous mutations, with one allele being a normal wild type and one being mutant. An efficient transport of glucose across the blood-brain barrier is essential as it is such an important fuel for the brain, and this is provided by glucose transporter type1 in the endothelial cells of the brain capillaries. Another minor contribution to the symptomatology of GLUT-1 may be impaired transport of an oxidised form of vitamin C. Treatment with anti-epileptic drugs may be needed, and the ketogenic diet may reduce symptoms, as ketosis can provide an alternative source of fuel for the brain. It has also been suggested that antioxidant thioctic acid may be of benefit. Substances such as caffeine and phenobarbitone should be avoided as they inhibit glucose transport.

  5. Diabetes and Altered Glucose Metabolism with Aging

    PubMed Central

    Kalyani, Rita Rastogi; Egan, Josephine M.

    2013-01-01

    I. Synopsis Diabetes and impaired glucose tolerance affect a substantial proportion of older adults. While the aging process can be associated with alterations in glucose metabolism, including both relative insulin resistance and islet cell dysfunction, abnormal glucose metabolism is not a necessary component of aging. Instead, older adults with diabetes and altered glucose status likely represent a vulnerable subset of the population at high-risk for complications and adverse geriatric syndromes such as accelerated muscle loss, functional disability, frailty, and early mortality. Goals for treatment of diabetes in the elderly include control of hyperglycemia, prevention and treatment of diabetic complications, avoidance of hypoglycemia and preservation of quality of life. Given the heterogeneity of the elderly population with regards to the presence of comorbidities, life expectancy, and functional status, an individualized approach to diabetes management is often appropriate. A growing area of research seeks to explore associations of dysglycemia and insulin resistance with the development of adverse outcomes in the elderly and may ultimately inform guidelines on the use of future glucose-lowering therapies in this population. PMID:23702405

  6. MicroRNA 33 Regulates Glucose Metabolism

    PubMed Central

    Ramírez, Cristina M.; Goedeke, Leigh; Rotllan, Noemi; Yoon, Je-Hyun; Cirera-Salinas, Daniel; Mattison, Julie A.; Suárez, Yajaira; de Cabo, Rafael; Gorospe, Myriam

    2013-01-01

    Metabolic diseases are characterized by the failure of regulatory genes or proteins to effectively orchestrate specific pathways involved in the control of many biological processes. In addition to the classical regulators, recent discoveries have shown the remarkable role of small noncoding RNAs (microRNAs [miRNAs]) in the posttranscriptional regulation of gene expression. In this regard, we have recently demonstrated that miR-33a and miR33b, intronic miRNAs located within the sterol regulatory element-binding protein (SREBP) genes, regulate lipid metabolism in concert with their host genes. Here, we show that miR-33b also cooperates with SREBP1 in regulating glucose metabolism by targeting phosphoenolpyruvate carboxykinase (PCK1) and glucose-6-phosphatase (G6PC), key regulatory enzymes of hepatic gluconeogenesis. Overexpression of miR-33b in human hepatic cells inhibits PCK1 and G6PC expression, leading to a significant reduction of glucose production. Importantly, hepatic SREBP1c/miR-33b levels correlate inversely with the expression of PCK1 and G6PC upon glucose infusion in rhesus monkeys. Taken together, these results suggest that miR-33b works in concert with its host gene to ensure a fine-tuned regulation of lipid and glucose homeostasis, highlighting the clinical potential of miR-33a/b as novel therapeutic targets for a range of metabolic diseases. PMID:23716591

  7. Glucose measurement in interstitial fluid by microdialysis for the calibration of minimally invasive blood glucose monitoring

    NASA Astrophysics Data System (ADS)

    Li, Dachao; Wang, Ridong; Chong, Hao; Liu, Yu; Xu, Kexin

    2013-03-01

    According to the requirement of the calibration in minimally invasive blood glucose monitoring, a method based on microdialysis was presented to monitor glucose level in interstitial fluid continuously. An experimental system simulating the continuous change of glucose concentration in vivo was built. The influences on recovery of microdialysis caused by flow rate, glucose concentration, and temperature etc. were studied. The results led to the conclusion that the recovery fell by 71.7% when perfusion rate increased from 0.3 μL/min to 3.0 μL/min, while the different concentrations of glucose solutions scarcely contribute to the recovery instead, and the temperatures from 25 to 58 °C caused the recovery to increase by 34.6%.

  8. Glucose positions affect the phloem mobility of glucose-fipronil conjugates.

    PubMed

    Lei, Zhiwei; Wang, Jie; Mao, Genlin; Wen, Yingjie; Tian, Yuxin; Wu, Huawei; Li, Yufeng; Xu, Hanhong

    2014-07-02

    In our previous work, a glucose-fipronil (GTF) conjugate at the C-1 position was synthesized via click chemistry and a glucose moiety converted a non-phloem-mobile insecticide fipronil into a moderately phloem-mobile insecticide. In the present paper, fipronil was introduced into the C-2, C-3, C-4, and C-6 positions of glucose via click chemistry to obtain four new conjugates and to evaluate the effects of the different glucose isomers on phloem mobility. The phloem mobility of the four new synthetic conjugates and GTF was tested using the Ricinus seedling system. The results confirmed that conjugation of glucose at different positions has a significant influence on the phloem mobility of GTF conjugates.

  9. Glucose nanosensors based on redox polymer/glucose oxidase modified carbon fiber nanoelectrodes.

    PubMed

    Fei, Junjie; Wu, Kangbing; Wang, Fang; Hu, Shengshui

    2005-02-28

    This paper describes glucose nanosensors based on the co-electrodeposition of a poly(vinylimidazole) complex of [Os(bpy)(2)Cl](+/2+) and glucose oxidase (GOD) on a low-noise carbon fiber nanoelectrodes (CFNE). The SEM image shows that the osmium redox polymer/enzyme composite film is uniform. The film modified CFNE exhibits the classical features of a kinetically fast redox couple bound to the electrode surface. A strong and stable electrocatalytic current is observed in the presence of glucose. Under the optimal experimental conditions, the nanosensor offers a highly sensitive and rapid response to glucose at an operating potential of 0.22V. A wide linear dynamic rang of 0.01-15mM range was achieved with a detection limit of 0.004mM. Compared with the conventional gold electrode, the nanosensor possessed higher sensitivity and longer stability. Successful attempts were made in real time monitoring rabbit blood glucose levels.

  10. Exogenous amino acids suppress glucose oxidation and potentiate hepatic glucose production in late gestation fetal sheep.

    PubMed

    Brown, Laura D; Kohn, Jaden R; Rozance, Paul J; Hay, William W; Wesolowski, Stephanie R

    2017-02-08

    Acute amino acid (AA) infusion increases AA oxidation rates in normal late gestation fetal sheep. Because fetal oxygen consumption rate does not change with increased AA oxidation, we hypothesized that AA infusion would suppress glucose oxidation pathways and that the additional carbon supply from AA would activate hepatic glucose production. To test this, late gestation fetal sheep were infused intravenously for 3h with saline or exogenous AA (AA). Glucose tracer metabolic studies were performed and skeletal muscle and liver tissues samples were collected. AA infusion increased fetal arterial plasma branched chain AA, cortisol, and glucagon concentrations. Fetal glucose utilization rates were similar between basal and AA periods, yet the fraction of glucose oxidized and glucose oxidation rate were decreased by 40% in the AA period. AA infusion increased expression of PDK4, an inhibitor of glucose oxidation, nearly 2-fold in muscle and liver. In liver, AA infusion tended to increase PCK1 gluconeogenic gene and PCK1 correlated with plasma cortisol concentrations. AA infusion also increased liver mRNA expression of lactate transporter gene (MCT1), protein expression of GLUT2 and LDHA, and phosphorylation of AMPK, 4EBP1, and S6 proteins. In isolated fetal hepatocytes, AA supplementation increased glucose production and PCK1, LDHA, and MCT1 gene expression. These results demonstrate that AA infusion into fetal sheep competitively suppresses glucose oxidation and potentiates hepatic glucose production. These metabolic patterns support flexibility in fetal metabolism in response to increased nutrient substrate supply while maintaining a relatively stable rate of oxidative metabolism.

  11. Astrocytic glucose-6-phosphatase and the permeability of brain microsomes to glucose 6-phosphate.

    PubMed Central

    Forsyth, R J; Bartlett, K; Burchell, A; Scott, H M; Eyre, J A

    1993-01-01

    Cells from primary rat astrocyte cultures express a 36.5 kDa protein that cross-reacts with polyclonal antibodies to the catalytic subunit of rat hepatic glucose-6-phosphatase on Western blotting. Glucose-6-phosphate-hydrolysing activity of the order of 10 nmol/min per mg of total cellular protein can be demonstrated in cell homogenates. This activity shows latency, and is localized to the microsomal fraction. Kinetic analysis shows a Km of 15 mM and a Vmax. of 30 nmol/min per mg of microsomal protein in disrupted microsomes. Approx. 40% of the total phosphohydrolase activity is specific glucose-6-phosphatase, as judged by sensitivity to exposure to pH 5 at 37 degrees C. Previous reports that the brain microsomal glucose-6-phosphatase system does not distinguish glucose 6-phosphate and mannose 6-phosphate are confirmed in astrocyte microsomes. However, we demonstrate significant phosphomannose isomerase activity in brain microsomes, allowing for ready interconversion between mannose 6-phosphate and glucose 6-phosphate (Vmax. 15 nmol/min per mg of microsomal protein; apparent Km < 1 mM; pH optimum 5-6 for the two-step conversion). This finding invalidates the past inference from the failure of brain microsomes to distinguish mannose 6-phosphate and glucose 6-phosphate that the cerebral glucose-6-phosphatase system lacks a 'glucose 6-phosphate translocase' [Fishman and Karnovsky (1986) J. Neurochem. 46, 371-378]. Furthermore, light-scattering experiments confirm that a proportion of whole brain microsomes is readily permeable to glucose 6-phosphate. Images Figure 1 PMID:8395816

  12. Comparison of /sup 3/H-galactose and /sup 3/H-glucose as precursors of hepatic glycogen in control-fed rats

    SciTech Connect

    Michaels, J.E.; Garfield, S.A.; Hung, J.T.; Cardell, R.R. Jr.

    1989-05-01

    Labeling of hepatic glycogen derived from 3H-galactose and 3H-glucose was compared shortly after intravenous injection in control-fed rats. The rats were allowed to accumulate 5-8% glycogen prior to receiving label. Fifteen minutes to 2 hours after labeling, liver was excised and processed for routine light (LM) and electron microscopic (EM) radioautography (RAG) or biochemical analysis. After injection of 3H-galactose, LM-RAGs revealed that the percentage of heavily labeled hepatocytes increased from 37% after 15 minutes to 68% after 1 hour but showed no further increase after 2 hours. alpha-Amylase treatment removed most glycogen and incorporated label; thus few silver grains were observed, indicating little incorporation of label except into glycogen. EM-RAGs demonstrated that most label occurred where glycogen was located. Biochemical analysis showed initially a high blood level of label that rapidly plateaued at a reduced level by 5 minutes. Concomitantly, glycogen labeling determined by liquid scintillation counting reflected the increases observed in the RAGs. After injection of 3H-glucose, LM-RAGs revealed that only 12% of the hepatocytes were heavily labeled at 1 hour and 20% at 2 hours. In tissue treated with alpha-amylase, glycogen was depleted and label was close to background level at each interval observed. EM-RAGs showed most grains associated with glycogen deposits. Biochemically, blood levels of label persisted at a high level for 30 minutes and tissue levels increased slowly over the 2-hour period. This study shows that incorporation from 3H-galactose was more rapid than incorporation of 3H-glucose; however, label derived from both carbohydrates appeared to be incorporated mainly into glycogen.

  13. Preclinical Performance Evaluation of Percutaneous Glucose Biosensors

    PubMed Central

    Soto, Robert J.; Schoenfisch, Mark H.

    2015-01-01

    The utility of continuous glucose monitoring devices remains limited by an obstinate foreign body response (FBR) that degrades the analytical performance of the in vivo sensor. A number of novel materials that resist or delay the FBR have been proposed as outer, tissue-contacting glucose sensor membranes as a strategy to improve sensor accuracy. Traditionally, researchers have examined the ability of a material to minimize the host response by assessing adsorbed cell morphology and tissue histology. However, these techniques do not adequately predict in vivo glucose sensor function, necessitating sensor performance evaluation in a relevant animal model prior to human testing. Herein, the effects of critical experimental parameters, including the animal model and data processing methods, on the reliability and usefulness of preclinical sensor performance data are considered. PMID:26085566

  14. Stable and flexible system for glucose homeostasis

    NASA Astrophysics Data System (ADS)

    Hong, Hyunsuk; Jo, Junghyo; Sin, Sang-Jin

    2013-09-01

    Pancreatic islets, controlling glucose homeostasis, consist of α, β, and δ cells. It has been observed that α and β cells generate out-of-phase synchronization in the release of glucagon and insulin, counter-regulatory hormones for increasing and decreasing glucose levels, while β and δ cells produce in-phase synchronization in the release of the insulin and somatostatin. Pieces of interactions between the islet cells have been observed for a long time, although their physiological role as a whole has not been explored yet. We model the synchronized hormone pulses of islets with coupled phase oscillators that incorporate the observed cellular interactions. The integrated model shows that the interaction from β to δ cells, of which sign is a subject of controversy, should be positive to reproduce the in-phase synchronization between β and δ cells. The model also suggests that δ cells help the islet system flexibly respond to changes of glucose environment.

  15. Cerebral glucose consumption following verbal auditory stimulation.

    PubMed

    Kushner, M J; Schwartz, R; Alavi, A; Dann, R; Rosen, M; Silver, F; Reivich, M

    1987-04-14

    We studied the effect of auditory stimulation upon cerebral glucose metabolism in young normals. The stimulus consisted of a non-English discourse which was presented monaurally to 10 normal blindfolded subjects (5 left ear, 5 right); the opposite ear was plugged. Six subjects studied blindfolded and with ears plugged served as controls. Sixteen discrete homologous cortical and subcortical regions of interest were examined. Regional glucose consumption and side-to-side differences in glucose metabolism were analyzed. Monaural stimulation produced significant increases in temporal metabolism contralateral to the side of stimulation. Significant asymmetries in metabolism were found at the temporoparietal junction, inferior parietal region, insula and corpus collosum. The left frontal speech areas remained unaffected. These findings demonstrate that in man the primary auditory pathways retain a contralateral organization. Further, cerebral activation induced by non-meaningful verbal stimulation is widespread within the left temporal and parietal regions but does not impact upon the frontal speech cortices.

  16. Accuracy of Handheld Blood Glucose Meters at High Altitude

    PubMed Central

    de Vries, Suzanna T.; Fokkert, Marion J.; Dikkeschei, Bert D.; Rienks, Rienk; Bilo, Karin M.; Bilo, Henk J. G.

    2010-01-01

    Background Due to increasing numbers of people with diabetes taking part in extreme sports (e.g., high-altitude trekking), reliable handheld blood glucose meters (BGMs) are necessary. Accurate blood glucose measurement under extreme conditions is paramount for safe recreation at altitude. Prior studies reported bias in blood glucose measurements using different BGMs at high altitude. We hypothesized that glucose-oxidase based BGMs are more influenced by the lower atmospheric oxygen pressure at altitude than glucose dehydrogenase based BGMs. Methodology/Principal Findings Glucose measurements at simulated altitude of nine BGMs (six glucose dehydrogenase and three glucose oxidase BGMs) were compared to glucose measurement on a similar BGM at sea level and to a laboratory glucose reference method. Venous blood samples of four different glucose levels were used. Moreover, two glucose oxidase and two glucose dehydrogenase based BGMs were evaluated at different altitudes on Mount Kilimanjaro. Accuracy criteria were set at a bias <15% from reference glucose (when >6.5 mmol/L) and <1 mmol/L from reference glucose (when <6.5 mmol/L). No significant difference was observed between measurements at simulated altitude and sea level for either glucose oxidase based BGMs or glucose dehydrogenase based BGMs as a group phenomenon. Two GDH based BGMs did not meet set performance criteria. Most BGMs are generally overestimating true glucose concentration at high altitude. Conclusion At simulated high altitude all tested BGMs, including glucose oxidase based BGMs, did not show influence of low atmospheric oxygen pressure. All BGMs, except for two GDH based BGMs, performed within predefined criteria. At true high altitude one GDH based BGM had best precision and accuracy. PMID:21103399

  17. Sirtuins in glucose and lipid metabolism

    PubMed Central

    Ye, Xin; Li, Meiting; Hou, Tianyun; Gao, Tian; Zhu, Wei-guo; Yang, Yang

    2017-01-01

    Sirtuins are evolutionarily conserved protein, serving as nicotinamide adenine dinucleotide-dependent deacetylases or adenosine diphosphate-ribosyltransferases. The mammalian sirtuins family, including SIRT1~7, is involved in many biological processes such as cell survival, proliferation, senescence, stress response, genome stability and metabolism. Evidence accumulated over the past two decades has indicated that sirtuins not only serve as important energy status sensors but also protect cells against metabolic stresses. In this review, we summarize the background of glucose and lipid metabolism concerning sirtuins and discuss the functions of sirtuins in glucose and lipid metabolism. We also seek to highlight the biological roles of certain sirtuins members in cancer metabolism. PMID:27659520

  18. Purinergic inhibition of glucose transport in cardiomyocytes.

    PubMed

    Fischer, Y; Becker, C; Löken, C

    1999-01-08

    ATP is known to act as an extracellular signal in many organs. In the heart, extracellular ATP modulates ionic processes and contractile function. This study describes a novel, metabolic effect of exogenous ATP in isolated rat cardiomyocytes. In these quiescent (i.e. noncontracting) cells, micromolar concentrations of ATP depressed the rate of basal, catecholamine-stimulated, or insulin-stimulated glucose transport by up to 60% (IC50 for inhibition of insulin-dependent glucose transport, 4 microM). ATP decreased the amount of glucose transporters (GLUT1 and GLUT4) in the plasma membrane, with a concomitant increase in intracellular microsomal membranes. A similar glucose transport inhibition was produced by P2 purinergic agonists with the following rank of potencies: ATP approximately ATPgammaS approximately 2-methylthio-ATP (P2Y-selective) > ADP > alpha,betameATP (P2X-selective), whereas the P1 purinoceptor agonist adenosine was ineffective. The effect of ATP was suppressed by the poorly subtype-selective P2 antagonist pyridoxal-phosphate-6-azophenyl-2', 4'-disulfonic acid but, surprisingly, not by the nonselective antagonist suramin nor by the P2Y-specific Reactive Blue 2. Glucose transport inhibition by ATP was not affected by a drastic reduction of the extracellular concentrations of calcium (down to 10(-9) M) or sodium (down to 0 mM), and it was not mimicked by a potassium-induced depolarization, indicating that purinoceptors of the P2X family (which are nonselective cation channels whose activation leads to a depolarizing sodium and calcium influx) are not involved. Inhibition was specific for the transmembrane transport of glucose because ATP did not inhibit (i) the rate of glycolysis under conditions where the transport step is no longer rate-limiting nor (ii) the rate of [1-14C]pyruvate decarboxylation. In conclusion, extracellular ATP markedly inhibits glucose transport in rat cardiomyocytes by promoting a redistribution of glucose transporters from the

  19. Glucose electro-oxidizing biofuel cell anodes

    NASA Astrophysics Data System (ADS)

    Binyamin, Gary Neil

    The glucose electro-oxidizing anode for a proposed biofuel cell operating at a current density of 1 mA cm-2 in a 1 mW, 1 cm 3 cell with an oxygen cathode is developed. The anode is based on electrically "wiring" the reaction centers of glucose oxidase to a carbon electrode through an electron conducting redox hydrogel. A flow system is simulated using rotating disk electrodes in variable volumes. The relationship between the mechanical strength and electron transport within the redox hydrogels was determined and a mechanically stable composite anode was designed. The anode was successfully tested under the shear stress of 0.06 N/m2, similar to that produced by a fluid flowing at a linear velocity of ˜10 cm-1 in a tubular cell of 2--5 mm diameter. A composite anode was made of hydrophilized graphite particles bound by the "wired" enzyme. When the enzyme was fully glucose-complexed, glucose was electrooxidized at a current density of 1.9 mA cm-2. H2O2 and gluconolactone, the two known damaging reaction products of the glucose oxidase-catalyzed oxidation of glucose by O2, did not rapidly damage the anodes in this system. The anodes were, however damaged by the transition metal ions and urate present in serum. The transition metal ions coordinatively crosslinked heterocyclic nitrogens of the "wires" reducing their segmental mobility and thereby the transport of electrons and also inhibited the glucose oxidase catalyzed-oxidation of glucose. Urate damaged the anodes because it was oxidatively electropolymerized and the polymer formed precipitated in the enzyme "wiring" film. The damage by transition metal ions and by urate can be alleviated by overcoating the anode films with thin membranes that do not limit mass transport. A slightly (0.05mA cm2) oxidizing shift in Tafel region of a biofuel cell cathode is observed by overcoating high surface area platinum black with superoxide dismutase and albumin. A "wired" pyruvate oxidase anode, sensitive over physiological

  20. [Glucose transporter type 1 (GLUT-1) deficiency].

    PubMed

    Cano, A; Ticus, I; Chabrol, B

    2008-11-01

    Impaired glucose transport across the blood brain barrier results in glucose transporter type 1 (GLUT-1) deficiency syndrome, first described in 1991. It is characterized by infantile seizures refractory to anticonvulsive treatments, microcephaly, delays in mental and motor development, spasticity, ataxia, dysarthria and other paroxysmal neurologic phenomena, often occurring prior to meals. Affected infants are normal at birth following an uneventful pregnancy and delivery. Seizures usually begin between the age of one and four months and can be preceded by apneic episodes or abnormal eyes movements. Patients with atypical presentations such as mental retardation and intermittent ataxia without seizures, or movement disorders characterized by choreoathetosis and dystonia, have also been described. Glucose is the principal fuel source for the brain and GLUT-1 is the only vehicle by which glucose enters the brain. In case of GLUT-1 deficiency, the risk of clinical manifestations is increased in infancy and childhood, when the brain glucose demand is maximal. The hallmark of the disease is a low glucose concentration in the cerebrospinal fluid in a presence of normoglycemia (cerebrospinal fluid/blood glucose ratio less than 0.4). The GLUT-1 defect can be confirmed by molecular analysis of the SCL2A1 gene or in erythrocytes by glucose uptake studies and GLUT-1 immunoreactivity. Several heterozygous mutations, with a majority of de novo mutations, resulting in GLUT-1 haploinsufficiency, have been described. Cases with an autosomal dominant transmission have been established and adults can exhibit symptoms of this deficiency. Ketogenic diet is an effective treatment of epileptic manifestations as ketone bodies serve as an alternative fuel for the developing brain. However, this diet is not effective on cognitive impairment and other treatments are being evaluated. The physiopathology of this disorder is partially unclear and its understanding could explain the clinical

  1. Acute effects of nicorandil on glucose tolerance in subjects with borderline fasting blood glucose levels.

    PubMed

    Boes, U; Wallner, S; Wascher, T C

    2001-02-15

    The acute effect of the anti-ischemic potassium channel opener nicorandil on glucose tolerance and post-challenge insulin levels was investigated in 11 subjects (6 males and 5 females, age 59 +/- 2 years) with borderline fasting blood glucose in a single blinded randomised study. All participants were submitted to two oral glucose tolerance tests in randomised order, once without any premedication and once 30 minutes after oral administration of 20 mg nicorandil. This single dose of nicorandil significantly increased blood glucose levels at 120 minutes (173 +/- 16 vs. 150 +/- 11 mg/dl, p < 0.05 by ANOVA) and 180 minutes (106 +/- 11 vs. 88 +/- 7 mg/dl, p < 0.05 by ANOVA) after ingestion of 75 mg of glucose. Serum insulin levels were not significantly altered. In conclusion we suggest that controlled studies in patients with coronary artery disease should be performed to investigate whether long term treatment with nicorandil increases progression rates from impaired glucose tolerance to type-II diabetes and/or from normal to impaired glucose tolerance with a possibly negative impact on the course of cardiovascular disease in comparison to conventional anti-anginal drugs.

  2. Antipsychotics inhibit glucose transport: Determination of olanzapine binding site in Staphylococcus epidermidis glucose/H(+) symporter.

    PubMed

    Babkin, Petr; George Thompson, Alayna M; Iancu, Cristina V; Walters, D Eric; Choe, Jun-Yong

    2015-01-01

    The antipsychotic drug olanzapine is widely prescribed to treat schizophrenia and other psychotic disorders. However, it often causes unwanted side effects, including diabetes, due to disruption of insulin-dependant glucose metabolism through a mechanism yet to be elucidated. To determine if olanzapine can affect the first step in glucose metabolism - glucose transport inside cells - we investigated the effect of this drug on the transport activity of a model glucose transporter. The glucose transporter from Staphylococcus epidermidis (GlcPSe) is specific for glucose, inhibited by various human glucose transporter (GLUT) inhibitors, has high sequence and structure homology to GLUTs, and is readily amenable to transport assay, mutagenesis, and computational modeling. We found that olanzapine inhibits glucose transport of GlcPSe with an IC50 0.9 ± 0.1 mM. Computational docking of olanzapine to the GlcPSe structure revealed potential binding sites that were further examined through mutagenesis and transport assay to identify residues important for olanzapine inhibition. These investigations suggest that olanzapine binds in a polar region of the cytosolic part of the transporter, and interacts with residues R129, strictly conserved in all GLUTs, and N136, conserved in only a few GLUTs, including the insulin-responsive GLUT4. We propose that olanzapine inhibits GlcPSe by impeding the alternating opening and closing of the substrate cavity necessary for glucose transport. It accomplishes this by disrupting a key salt bridge formed by conserved residues R129 and E362, that stabilizes the outward-facing conformation of the transporter.

  3. Novel fungal FAD glucose dehydrogenase derived from Aspergillus niger for glucose enzyme sensor strips.

    PubMed

    Sode, Koji; Loew, Noya; Ohnishi, Yosuke; Tsuruta, Hayato; Mori, Kazushige; Kojima, Katsuhiro; Tsugawa, Wakako; LaBelle, Jeffrey T; Klonoff, David C

    2017-01-15

    In this study, a novel fungus FAD dependent glucose dehydrogenase, derived from Aspergillus niger (AnGDH), was characterized. This enzyme's potential for the use as the enzyme for blood glucose monitor enzyme sensor strips was evaluated, especially by investigating the effect of the presence of xylose during glucose measurements. The substrate specificity of AnGDH towards glucose was investigated, and only xylose was found as a competing substrate. The specific catalytic efficiency for xylose compared to glucose was 1.8%. The specific activity of AnGDH for xylose at 5mM concentration compared to glucose was 3.5%. No other sugars were used as substrate by this enzyme. The superior substrate specificity of AnGDH was also demonstrated in the performance of enzyme sensor strips. The impact of spiking xylose in a sample with physiological glucose concentrations on the sensor signals was investigated, and it was found that enzyme sensor strips using AnGDH were not affected at all by 5mM (75mg/dL) xylose. This is the first report of an enzyme sensor strip using a fungus derived FADGDH, which did not show any positive bias at a therapeutic level xylose concentration on the signal for a glucose sample. This clearly indicates the superiority of AnGDH over other conventionally used fungi derived FADGDHs in the application for SMBG sensor strips. The negligible activity of AnGDH towards xylose was also explained on the basis of a 3D structural model, which was compared to the 3D structures of A. flavus derived FADGDH and of two glucose oxidases.

  4. Investigation for terminal reflection optical fiber SPR glucose sensor and glucose sensitive membrane with immobilized GODs.

    PubMed

    Yuan, Yinquan; Yang, Xi; Gong, Dejing; Liu, Fang; Hu, Wenbin; Cai, Weiquan; Huang, Jun; Yang, Minghong

    2017-02-20

    Glucose sensitive membrane (GSM) consists of glucose oxidases (GODs) and matrix material (for example, polyacrylamide gel). In this paper, we have investigated the optical property and adsorption isotherms of a GSM based on a terminal reflection optical fiber SPR sensor. Firstly, we reported the fabrication of one kind of GSM which was made of immobilized GODs on SiO2 nanoparticles and PAM gel. Then, we investigated the effects of GSM thickness, GOD content, solution pH and ambient temperature on the reflected spectrum of sensor, and the optimum parameters of the sensor, such as, GSM thickness of 12 times pulling, 4 mg/mL of GOD content in GSM, 7.0 of solution pH and 40 °C of measuring temperature were obtained. Thirdly, we measured the wavelength shifts of the optimized SPR sensor in the solutions with different glucose concentrations. As the glucose concentration increases from 0 to 80 mg/dL, the resonance wavelength decreases approximately linearly and the corresponding sensitivity is about 0.14 nm/(mg/dL). Finally, we investigated the RI of the GSM, the concentration of glucose into GSM and the adsorption isotherm of GSM by the combination of SPR experiment data, theoretical simulation and Gladstone-Dale mixing rule. As the glucose concentration is in the region of [0, 80] mg/dL, the adsorption of GSM for glucose can be explained by the Freundlich isotherm model. As the glucose concentration is in the region of [120, 500] mg/dL, the Langmuir isotherm model is more suitable to describe the adsorption process of GSM for glucose.

  5. Metabolic ketoacidosis with normal blood glucose: A rare complication of sodium–glucose cotransporter 2 inhibitors

    PubMed Central

    Ullah, Saad; Khan, Noman; Zeb, Hassan; Tahir, Hassan

    2016-01-01

    Ketoacidosis is a significant and often a life-threatening complication of diabetes mellitus seen mostly in type 1 diabetes mellitus as well as occasionally in type 2 diabetes mellitus. Diabetic ketoacidosis usually manifests with high blood glucose more than 250 mg/dL, but euglycemic diabetic ketoacidosis is defined as ketoacidosis associated with blood glucose level less than 250 mg/dL. Normal blood glucose in such patients results in significant delay in diagnosis and management of diabetic ketoacidosis, thus increasing mortality and morbidity. We present a case of euglycemic diabetic ketoacidosis secondary to canagliflozin in a type 2 diabetic patient. PMID:27928503

  6. Predictive models of glucose control: roles for glucose-sensing neurones.

    PubMed

    Kosse, C; Gonzalez, A; Burdakov, D

    2015-01-01

    The brain can be viewed as a sophisticated control module for stabilizing blood glucose. A review of classical behavioural evidence indicates that central circuits add predictive (feedforward/anticipatory) control to the reactive (feedback/compensatory) control by peripheral organs. The brain/cephalic control is constructed and engaged, via associative learning, by sensory cues predicting energy intake or expenditure (e.g. sight, smell, taste, sound). This allows rapidly measurable sensory information (rather than slowly generated internal feedback signals, e.g. digested nutrients) to control food selection, glucose supply for fight-or-flight responses or preparedness for digestion/absorption. Predictive control is therefore useful for preventing large glucose fluctuations. We review emerging roles in predictive control of two classes of widely projecting hypothalamic neurones, orexin/hypocretin (ORX) and melanin-concentrating hormone (MCH) cells. Evidence is cited that ORX neurones (i) are activated by sensory cues (e.g. taste, sound), (ii) drive hepatic production, and muscle uptake, of glucose, via sympathetic nerves, (iii) stimulate wakefulness and exploration via global brain projections and (iv) are glucose-inhibited. MCH neurones are (i) glucose-excited, (ii) innervate learning and reward centres to promote synaptic plasticity, learning and memory and (iii) are critical for learning associations useful for predictive control (e.g. using taste to predict nutrient value of food). This evidence is unified into a model for predictive glucose control. During associative learning, inputs from some glucose-excited neurones may promote connections between the 'fast' senses and reward circuits, constructing neural shortcuts for efficient action selection. In turn, glucose-inhibited neurones may engage locomotion/exploration and coordinate the required fuel supply. Feedback inhibition of the latter neurones by glucose would ensure that glucose fluxes they stimulate

  7. Design of nanostructured-based glucose biosensors

    NASA Astrophysics Data System (ADS)

    Komirisetty, Archana; Williams, Frances; Pradhan, Aswini; Konda, Rajini B.; Dondapati, Hareesh; Samantaray, Diptirani

    2012-04-01

    This paper presents the design of glucose sensors that will be integrated with advanced nano-materials, bio-coatings and electronics to create novel devices that are highly sensitive, inexpensive, accurate, and reliable. In the work presented, a glucose biosensor and its fabrication process flow have been designed. The device is based on electrochemical sensing using a working electrode with bio-functionalized zinc oxide (ZnO) nano-rods. Among all metal oxide nanostructures, ZnO nano-materials play a significant role as a sensing element in biosensors due to their properties such as high isoelectric point (IEP), fast electron transfer, non-toxicity, biocompatibility, and chemical stability which are very crucial parameters to achieve high sensitivity. Amperometric enzyme electrodes based on glucose oxidase (GOx) are used due to their stability and high selectivity to glucose. The device also consists of silicon dioxide and titanium layers as well as platinum working and counter electrodes and a silver/silver chloride reference electrode. Currently, the biosensors are being fabricated using the process flow developed. Once completed, the sensors will be bio-functionalized and tested to characterize their performance, including their sensitivity and stability.

  8. Regulation of glucose homeostasis by GLP-1.

    PubMed

    Nadkarni, Prashant; Chepurny, Oleg G; Holz, George G

    2014-01-01

    Glucagon-like peptide-1(7-36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeostasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics.

  9. Enzymatic production of hydrogen from glucose

    SciTech Connect

    Woodward, J.; Mattingly, S.M.

    1995-06-01

    The objective of this research is to optimize conditions for the enzymatic production of hydrogen gas from biomass-derived glucose. This new project is funded at 0.5 PY level of effort for FY 1995. The rationale for the work is that cellulose is, potentially, a vast source of hydrogen and that enzymes offer a specific and efficient method for its extraction with minimal environmental impact. This work is related to the overall hydrogen program goal of technology development and validation. The approach is based on knowledge that glucose is oxidized by the NADP{sup +} requiring enzyme glucose dehydrogenase (GDH) and that the resulting NADPH can donate its electrons to hydrogenase (H{sub 2}ase) which catalyzes the evolution of H{sub 2}. Thus hydrogen production from glucose was achieved using calf liver GDH and Pyrococcus furiosus H{sub 2}ase yielding 17% of theoretical maximum expected. The cofactor NADP{sup +} for this reaction was regenerated and recycled. Current and future work includes understanding the rate limiting steps of this process and the stabilization/immobilization of the enzymes for long term hydrogen production. Cooperative interactions with the Universities of Georgia and Bath for obtaining thermally stable enzymes are underway.

  10. Continuous glucose monitoring: current clinical use.

    PubMed

    Kim, Hun-Sung; Shin, Jeong-Ah; Chang, Jin-Sun; Cho, Jae-Hyoung; Son, Ho-Young; Yoon, Kun-Ho

    2012-12-01

    Four kinds of subcutaneous continuous glucose monitoring (CGM) machines have been currently introduced in clinical practice. These machines exhibit real-time glucose on the monitor every 5 minutes and have alarms to indicate hypoglycaemia and hyperglycaemia. However, thus far, there is no clear consensus about the clinical indications for CGM in actual clinical practice. CGM should be an ideal and powerful tool for monitoring glucose variability. Glycaemic variability has become a major concern over the years with growing evidence on its detrimental impact with respect to the risk of diabetic complications. Although the HbA1c level is ubiquitously measures in clinical practice, this level does not adequately represent glycaemic variability. Currently available evidence indicates that CGM aids in lowering the HbA1c level without increasing the incidence of severe hypoglycaemic episodes in patients with type 1 diabetes. Thus far, CGM has not been indicated for preventing severe hypoglycaemia or for treating type 2 diabetes because sufficient supporting evidence has not been obtained. Promising results have been obtained for the use of CGM for pregnant women with diabetes and for patients with hospital hyperglycaemia. Predictions regarding the feasibility of the closed-loop system have proven to be optimistic. CGM-integrated communication systems using information technology such as smart phone help controlling blood glucose more easily and effectively.

  11. Clean conversion of cellulose into fermentable glucose.

    PubMed

    Sun, Yong; Zhuang, Junping; Lin, Lu; Ouyang, Pingkai

    2009-01-01

    We studied the process of conversion of microcrystalline-cellulose into fermentable glucose in the formic acid reaction system using cross polarization/magic angle spinning (13)C-nuclear magnetic resonance, X-ray diffraction and Fourier transform infrared spectroscopy. The results indicated that formic acid as an active agent was able to effectively penetrate into the interior space of the cellulose molecules, thus collapsing the rigid crystalline structure and allowing hydrolysis to occur easily in the amorphous zone as well as in the crystalline zone. The microcrystalline-cellulose was hydrolyzed using formic acid and 4% hydrochloric acid under mild conditions. The effects of hydrochloric acid concentration, the ratio of solid to liquid, temperature (55-75 degrees C) and retention time (0-9 h), and the concentration of glucose were analyzed. The hydrolysis velocities of microcrystalline-cellulose were 6.14 x 10(-3) h(-1) at 55 degrees C, 2.94 x 10(-2) h(-1) at 65 degrees C, and 6.84x10(-2) h(-1) at 75 degrees C. The degradation velocities of glucose were 0.01 h(-1) at 55 degrees C, 0.14 h(-1) at 65 degrees C, 0.34 h(-1) at 75 degrees C. The activation energy of microcrystalline-cellulose hydrolysis was 105.61 kJ/mol, and the activation energy of glucose degradation was 131.37 kJ/mol.

  12. Regulation of Glucose Homeostasis by GLP-1

    PubMed Central

    Nadkarni, Prashant; Chepurny, Oleg G.; Holz, George G.

    2014-01-01

    Glucagon-like peptide-1(7–36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeo-stasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics. PMID:24373234

  13. Ketosis proportionately spares glucose utilization in brain.

    PubMed

    Zhang, Yifan; Kuang, Youzhi; Xu, Kui; Harris, Donald; Lee, Zhenghong; LaManna, Joseph; Puchowicz, Michelle A

    2013-08-01

    The brain is dependent on glucose as a primary energy substrate, but is capable of utilizing ketones such as β-hydroxybutyrate and acetoacetate, as occurs with fasting, starvation, or chronic feeding of a ketogenic diet. The relationship between changes in cerebral metabolic rates of glucose (CMRglc) and degree or duration of ketosis remains uncertain. To investigate if CMRglc decreases with chronic ketosis, 2-[(18)F]fluoro-2-deoxy-D-glucose in combination with positron emission tomography, was applied in anesthetized young adult rats fed 3 weeks of either standard or ketogenic diets. Cerebral metabolic rates of glucose (μmol/min per 100 g) was determined in the cerebral cortex and cerebellum using Gjedde-Patlak analysis. The average CMRglc significantly decreased in the cerebral cortex (23.0±4.9 versus 32.9±4.7) and cerebellum (29.3±8.6 versus 41.2±6.4) with increased plasma ketone bodies in the ketotic rats compared with standard diet group. The reduction of CMRglc in both brain regions correlates linearly by ∼9% for each 1 mmol/L increase of total plasma ketone bodies (0.3 to 6.3 mmol/L). Together with our meta-analysis, these data revealed that the degree and duration of ketosis has a major role in determining the corresponding change in CMRglc with ketosis.

  14. Hydrolysis of ionic cellulose to glucose.

    PubMed

    Vo, Huyen Thanh; Widyaya, Vania Tanda; Jae, Jungho; Kim, Hoon Sik; Lee, Hyunjoo

    2014-09-01

    Hydrolysis of ionic cellulose (IC), 1,3-dimethylimidazolium cellulose phosphite, which could be synthesized from cellulose and dimethylimidazolium methylphosphite ([Dmim][(OCH3)(H)PO2]) ionic liquid, was conducted for the synthesis of glucose. The reaction without catalysts at 150°C for 12h produced glucose with 14.6% yield. To increase the hydrolysis yield, various acid catalysts were used, in which the sulfonated active carbon (AC-SO3H) performed the best catalytic activity in the IC hydrolysis. In the presence of AC-SO3H, the yields of glucose reached 42.4% and 53.9% at the reaction condition of 150°C for 12h and 180°C for 1.5h, respectively; however the yield decreased with longer reaction time due to the degradation of glucose. Consecutive catalyst reuse experiments on the IC hydrolysis demonstrated the catalytic activity of AC-SO3H persisted at least through four successive uses.

  15. An unbiased lipidomics approach identifies early second trimester lipids predictive of Maternal Glycemic Traits and Gestational Diabetes Mellitus

    PubMed Central

    Lu, Liangjian; Koulman, Albert; Petry, Clive J.; Jenkins, Benjamin; Matthews, Lee; Hughes, Ieuan A.; Acerini, Carlo L.; Ong, Ken K.; Dunger, David B.

    2016-01-01

    Objective To investigate the relationship between early second trimester serum lipidomic variation and maternal glycemic traits at 28 weeks, and to identify predictive lipid biomarkers for Gestational Diabetes (GDM). Research Design and Methods Prospective study of 817 pregnant women (Discovery cohort, n=200; Validation cohort, n=617) who provided an early second trimester serum sample, and underwent oral glucose tolerance testing (OGTT) at 28 weeks. In the discovery cohort, lipids were measured using direct infusion mass spectrometry, and correlated with OGTT results. Variable Importance in Projection (VIP) scores were used to identify candidate lipid biomarkers. Candidate biomarkers were measured in the validation cohort using Liquid Chromatography- Mass Spectrometry, and tested for associations with OGTT results and GDM status. Results Early second trimester lipidomic variation was associated with 1-hour post-load glucose levels, but not with fasting plasma glucose. Of the 13 lipid species identified by VIP scores, 10 had nominally significant associations with post-load glucose levels. In the validation cohort, 5 of these 10 lipids had significant associations with post-load glucose levels independent of maternal age and BMI, i.e. TG(51:1), TG(48:1), PC(32:1), PCae(40:3) and PCae(40:4). All except the last were also associated with maternal GDM status. Together, these 4 lipid biomarkers had moderate ability to predict GDM (Area under curve (AUC)= 0.71±0.04, p=4.85×10-7), and improved the prediction of GDM by age and BMI alone from AUC 0.69 to AUC 0.74. Conclusions Specific early second trimester lipid biomarkers can predict maternal GDM status independent of maternal age and BMI, potentially enhancing risk factor-based screening. PMID:27703025

  16. Cutpoints for screening blood glucose concentrations in healthy senior cats.

    PubMed

    Reeve-Johnson, Mia K; Rand, Jacquie S; Vankan, Dianne; Anderson, Stephen T; Marshall, Rhett; Morton, John M

    2017-02-01

    Objectives The objectives of this study were to determine the reference interval for screening blood glucose in senior cats, to apply this to a population of obese senior cats, to compare screening and fasting blood glucose, to assess whether screening blood glucose is predicted by breed, body weight, body condition score (BCS), behaviour score, fasting blood glucose and/or recent carbohydrate intake and to assess its robustness to changes in methodology. Methods The study included a total of 120 clinically healthy client-owned cats aged 8 years and older of varying breeds and BCSs. Blood glucose was measured at the beginning of the consultation from an ear/paw sample using a portable glucose meter calibrated for cats, and again after physical examination from a jugular sample. Fasting blood glucose was measured after overnight hospitalisation and fasting for 18-24 h. Results The reference interval upper limit for screening blood glucose was 189 mg/dl (10.5 mmol/l). Mean screening blood glucose was greater than mean fasting glucose. Breed, body weight, BCS, behaviour score, fasting blood glucose concentration and amount of carbohydrate consumed 2-24 h before sampling collectively explained only a small proportion of the variability in screening blood glucose. Conclusions and relevance Screening blood glucose measurement represents a simple test, and cats with values from 117-189 mg/dl (6.5-10.5 mmol/l) should be retested several hours later. Cats with initial screening blood glucose >189 mg/dl (10.5 mmol/l), or a second screening blood glucose >116 mg/dl (6.4 mmol/l) several hours after the first, should have fasting glucose and glucose tolerance measured after overnight hospitalisation.

  17. Glucose metabolism in pregnant sheep when placental growth is restricted

    SciTech Connect

    Owens, J.A.; Falconer, J.; Robinson, J.S. )

    1989-08-01

    The effect of restricting placental growth on glucose metabolism in pregnant sheep in late gestation was determined by primed constant infusions of D-(U-{sup 14}C)- and D-(2-{sup 3}H)glucose and antipyrine into fetuses of six control sheep and six sheep from which endometrial caruncles had been removed before pregnancy (caruncle sheep). In the latter, placental and fetal weights were reduced, as was the concentration of glucose in fetal arterial blood. Fetal glucose turnover in caruncle sheep was only 52-59% of that in controls, largely because of lower umbilical loss of glucose back to the placenta (38-39% of control) and lower fetal glucose utilization (61-74% of control). However, fetal glucose utilization on a weight-specific basis was similar in control and caruncle sheep. Significant endogenous glucose production occurred in control and caruncle fetal sheep. Maternal glucose production and partition of glucose between the gravid uterus and other maternal tissues were similar in control and caruncle sheep. In conclusion, when placental and fetal growth are restricted, fetal glucose utilization is maintained by reduced loss of glucose back to the placenta and mother and by maintaining endogenous glucose production.

  18. Insulin Signaling in the Control of Glucose and Lipid Homeostasis.

    PubMed

    Saltiel, Alan R

    2016-01-01

    A continuous supply of glucose is necessary to ensure proper function and survival of all organs. Plasma glucose levels are thus maintained in a narrow range around 5 mM, which is considered the physiological set point. Glucose homeostasis is controlled primarily by the liver, fat, and skeletal muscle. Following a meal, most glucose disposals occur in the skeletal muscle, whereas fasting plasma glucose levels are determined primarily by glucose output from the liver. The balance between the utilization and production of glucose is primarily maintained at equilibrium by two opposing hormones, insulin and glucagon. In response to an elevation in plasma glucose and amino acids (after consumption of a meal), insulin is released from the beta cells of the islets of Langerhans in the pancreas. When plasma glucose falls (during fasting or exercise), glucagon is secreted by α cells, which surround the beta cells in the pancreas. Both cell types are extremely sensitive to glucose concentrations, can regulate hormone synthesis, and are released in response to small changes in plasma glucose levels. At the same time, insulin serves as the major physiological anabolic agent, promoting the synthesis and storage of glucose, lipids, and proteins and inhibiting their degradation and release back into the circulation. This chapter will focus mainly on signal transduction mechanisms by which insulin exerts its plethora of effects in liver, muscle, and fat cells, focusing on those pathways that are crucial in the control of glucose and lipid homeostasis.

  19. Experience-dependent escalation of glucose drinking and the development of glucose preference over fructose - association with glucose entry into the brain.

    PubMed

    Wakabayashi, Ken T; Spekterman, Laurence; Kiyatkin, Eugene A

    2016-06-01

    Glucose, a primary metabolic substrate for cellular activity, must be delivered to the brain for normal neural functions. Glucose is also a unique reinforcer; in addition to its rewarding sensory properties and metabolic effects, which all natural sugars have, glucose crosses the blood-brain barrier and acts on glucoreceptors expressed on multiple brain cells. To clarify the role of this direct glucose action in the brain, we compared the neural and behavioural effects of glucose with those induced by fructose, a sweeter yet metabolically equivalent sugar. First, by using enzyme-based biosensors in freely moving rats, we confirmed that glucose rapidly increased in the nucleus accumbens in a dose-dependent manner after its intravenous delivery. In contrast, fructose induced a minimal response only after a large-dose injection. Second, we showed that naive rats during unrestricted access consumed larger volumes of glucose than fructose solution; the difference appeared with a definite latency during the initial exposure and strongly increased during subsequent tests. When rats with equal sugar experience were presented with either glucose or fructose in alternating order, the consumption of both substances was initially equal, but only the consumption of glucose increased during subsequent sessions. Finally, rats with equal glucose-fructose experience developed a strong preference for glucose over fructose during a two-bottle choice procedure; the effect appeared with a definite latency during the initial test and greatly amplified during subsequent tests. Our results suggest that direct entry of glucose in the brain and its subsequent effects on brain cells could be critical for the experience-dependent escalation of glucose consumption and the development of glucose preference over fructose.

  20. Fabrication of Amperometric Glucose Sensor Using Glucose Oxidase-Cellulose Nanofiber Aqueous Solution.

    PubMed

    Yasuzawa, Mikito; Omura, Yuya; Hiura, Kentaro; Li, Jiang; Fuchiwaki, Yusuke; Tanaka, Masato

    2015-01-01

    Cellulose nanofiber aqueous solution, which remained virtually transparent for more than one week, was prepared by using the clear upper layer of diluted cellulose nanofiber solution produced by wet jet milling. Glucose oxidase (GOx) was easily dissolved in this solution and GOx-immobilized electrode was easily fabricated by simple repetitious drops of GOx-cellulose solution on the surface of a platinum-iridium electrode. Glucose sensor properties of the obtained electrodes were examined in phosphate buffer solution of pH 7.4 at 40°C. The obtained electrode provided a glucose sensor response with significantly high response speed and good linear relationship between glucose concentration and response current. After an initial decrease of response sensitivity for a few days, relatively constant sensitivity was obtained for about 20 days. Nevertheless, the influence of electroactive compounds such as ascorbic acid, uric acid and acetoaminophen were not negletable.

  1. Sodium-Glucose Cotransporter Inhibitors: Effects on Renal and Intestinal Glucose Transport: From Bench to Bedside.

    PubMed

    Mudaliar, Sunder; Polidori, David; Zambrowicz, Brian; Henry, Robert R

    2015-12-01

    Type 2 diabetes is a chronic disease with disabling micro- and macrovascular complications that lead to excessive morbidity and premature mortality. It affects hundreds of millions of people and imposes an undue economic burden on populations across the world. Although insulin resistance and insulin secretory defects play a major role in the pathogenesis of hyperglycemia, several other metabolic defects contribute to the initiation/worsening of the diabetic state. Prominent among these is increased renal glucose reabsorption, which is maladaptive in patients with diabetes. Instead of an increase in renal glucose excretion, which could ameliorate hyperglycemia, there is an increase in renal glucose reabsorption, which helps sustain hyperglycemia in patients with diabetes. The sodium-glucose cotransporter (SGLT) 2 inhibitors are novel antidiabetes agents that inhibit renal glucose reabsorption and promote glucosuria, thereby leading to reductions in plasma glucose concentrations. In this article, we review the long journey from the discovery of the glucosuric agent phlorizin in the bark of the apple tree through the animal and human studies that led to the development of the current generation of SGLT2 inhibitors.

  2. Brain areas and pathways in the regulation of glucose metabolism.

    PubMed

    Diepenbroek, Charlene; Serlie, Mireille J; Fliers, Eric; Kalsbeek, Andries; la Fleur, Susanne E

    2013-01-01

    Glucose is the most important source of fuel for the brain and its concentration must be kept within strict boundaries to ensure the organism's optimal fitness. To maintain glucose homeostasis, an optimal balance between glucose uptake and glucose output is required. Besides managing acute changes in plasma glucose concentrations, the brain controls a daily rhythm in glucose concentrations. The various nuclei within the hypothalamus that are involved in the control of both these processes are well known. However, novel studies indicate an additional role for brain areas that are originally appreciated in other processes than glucose metabolism. Therefore, besides the classic hypothalamic pathways, we will review cortico-limbic brain areas and their role in glucose metabolism.

  3. The effect of diet fat on rat adipocyte glucose transport.

    PubMed

    Ip, C; Tepperman, H M; De Witt, J; Tepperman, J

    1977-05-01

    Rats were fed either a high fat diet (67% of calories as lard) or high glucose diet (67% of calories as glucose) for 7-8 days. Basal and insulin stimulated net uptake of D glucose (D-L) and 2 deoxy D glucose uptake by free fat cells of fat rats were depressed. Net transport of D glucose (D-L) by purified adipocyte plasma membranes of fat red rats was also diminished. Incubation of fat cells from glucose fed rats with insulin before homogenization for membrane preparation increased net D glucose transport by subsequently purified membranes in two experiments to a greater extent than in similar preparations from rat fed rats. These experiments suggest that fat feeding modifies the plasma membranes of fat cells so that both glucose transport and the stimulatory effect of insulin on the process are decreased.

  4. Peripheral and Central Glucose Sensing In Hypoglycemic Detection

    PubMed Central

    Watts, Alan G.

    2014-01-01

    Hypoglycemia poses a serious threat to the integrity of the brain, owing to its reliance on blood glucose as a fuel. Protecting against hypoglycemia is an extended network of glucose sensors located within the brain and in the periphery that serve to mediate responses restoring euglycemia, i.e., counterregulatory responses. This review examines the various glucose sensory loci involved in hypoglycemic detection, with a particular emphasis on peripheral glucose sensory loci and their contribution to hypoglycemic counterregulation. PMID:25180261

  5. Modeling of glucose pH enzyme electrode

    SciTech Connect

    Sarbolouki, M.N.; Ghoorchian, H.; Mozaffari, S. )

    1990-08-01

    Fabrication of a modified glucose pH enzyme electrode, using cellulose acetate instead of cellophane, and its performance are described. A physico-mathematical model that considers glucose transport across the membrane from the bulk into the enzyme solution layer, subsequent proton generation as a consequence of glucose oxidation by the enzyme glucose oxidase, and proton transport back through the membrane into the bulk solution is developed. Proper rate equations are simultaneously solved. Experimental and theoretical results are compared.

  6. Regulation of glucose transport in skeletal muscle.

    PubMed

    Barnard, R J; Youngren, J F

    1992-11-01

    The entry of glucose into muscle cells is achieved primarily via a carrier-mediated system consisting of protein transport molecules. GLUT-1 transporter isoform is normally found in the sarcolemmal (SL) membrane and is thought to be involved in glucose transport under basal conditions. With insulin stimulation, glucose transport is accelerated by translocating GLUT-4 transporters from an intracellular pool out to the T-tubule and SL membranes. Activation of transporters to increase the turnover number may also be involved, but the evidence is far from conclusive. When insulin binds to its receptor, it autophosphorylates tyrosine and serine residues on the beta-subunit of the receptor. The tyrosine residues are thought to activate tyrosine kinases, which in turn phosphorylate/activate as yet unknown second messengers. Insulin receptor antibodies, however, have been reported to increase glucose transport without increasing kinase activity. Insulin resistance in skeletal muscle is a major characteristic of obesity and diabetes mellitus, especially NIDDM. A decrease in the number of insulin receptors and the ability of insulin to activate receptor tyrosine kinase has been documented in muscle from NIDDM patients. Most studies report no change in the intracellular pool of GLUT-4 transporters available for translocation to the SL. Both the quality and quantity of food consumed can regulate insulin sensitivity. A high-fat, refined sugar diet, similar to the typical U.S. diet, causes insulin resistance when compared with a low-fat, complex-carbohydrate diet. On the other hand, exercise increases insulin sensitivity. After an acute bout of exercise, glucose transport in muscle increases to the same level as with maximum insulin stimulation. Although the number of GLUT-4 transporters in the sarcolemma increases with exercise, neither insulin or its receptor is involved. After an initial acute phase, which may involve calcium as the activator, a secondary phase of increased

  7. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  8. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  9. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  10. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  11. Osmotic water transport with glucose in GLUT2 and SGLT.

    PubMed

    Naftalin, Richard J

    2008-05-15

    Carrier-mediated water cotransport is currently a favored explanation for water movement against an osmotic gradient. The vestibule within the central pore of Na(+)-dependent cotransporters or GLUT2 provides the necessary precondition for an osmotic mechanism, explaining this phenomenon without carriers. Simulating equilibrative glucose inflow via the narrow external orifice of GLUT2 raises vestibular tonicity relative to the external solution. Vestibular hypertonicity causes osmotic water inflow, which raises vestibular hydrostatic pressure and forces water, salt, and glucose into the outer cytosolic layer via its wide endofacial exit. Glucose uptake via GLUT2 also raises oocyte tonicity. Glucose exit from preloaded cells depletes the vestibule of glucose, making it hypotonic and thereby inducing water efflux. Inhibiting glucose exit with phloretin reestablishes vestibular hypertonicity, as it reequilibrates with the cytosolic glucose and net water inflow recommences. Simulated Na(+)-glucose cotransport demonstrates that active glucose accumulation within the vestibule generates water flows simultaneously with the onset of glucose flow and before any flow external to the transporter caused by hypertonicity in the outer cytosolic layers. The molar ratio of water/glucose flow is seen now to relate to the ratio of hydraulic and glucose permeability rather than to water storage capacity of putative water carriers.

  12. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Insoluble glucose isomerase enzyme preparations... Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production of high fructose corn syrup described in §...

  13. Enzymatic Glucose Sensor Compensation for Variations in Ambient Oxygen Concentration

    PubMed Central

    Collier, Bradley B.; McShane, Michael J.

    2014-01-01

    Due to the increasing prevalence of diabetes, research toward painless glucose sensing continues. Oxygen sensitive phosphors with glucose oxidase (GOx) can be used to determine glucose levels indirectly by monitoring oxygen consumption. This is an attractive combination because of its speed and specificity. Packaging these molecules together in “smart materials” for implantation will enable non-invasive glucose monitoring. As glucose levels increase, oxygen levels decrease; consequently, the luminescence intensity and lifetime of the phosphor increase. Although the response of the sensor is dependent on glucose concentration, the ambient oxygen concentration also plays a key role. This could lead to inaccurate glucose readings and increase the risk of hyper- or hypoglycemia. To mitigate this risk, the dependence of hydrogel glucose sensor response on oxygen levels was investigated and compensation methods explored. Sensors were calibrated at different oxygen concentrations using a single generic logistic equation, such that trends in oxygen-dependence were determined as varying parameters in the equation. Each parameter was found to be a function of oxygen concentration, such that the correct glucose calibration equation can be calculated if the oxygen level is known. Accuracy of compensation will be determined by developing an overall calibration, using both glucose and oxygen sensors in parallel, correcting for oxygen fluctuations in real time by intentionally varying oxygen, and calculating the error in actual and predicted glucose levels. While this method was developed for compensation of enzymatic glucose sensors, in principle it can also be implemented with other kinds of sensors utilizing oxidases. PMID:26257458

  14. Glucose utilization rates regulate intake levels of artificial sweeteners.

    PubMed

    Tellez, Luis A; Ren, Xueying; Han, Wenfei; Medina, Sara; Ferreira, Jozélia G; Yeckel, Catherine W; de Araujo, Ivan E

    2013-11-15

    It is well established that animals including humans attribute greater reinforcing value to glucose-containing sugars compared to their non-caloric counterparts, generally termed 'artificial sweeteners'. However, much remains to be determined regarding the physiological signals and brain systems mediating the attribution of greater reinforcing value to sweet solutions that contain glucose. Here we show that disruption of glucose utilization in mice produces an enduring inhibitory effect on artificial sweetener intake, an effect that did not depend on sweetness perception or aversion. Indeed, such an effect was not observed in mice presented with a less palatable, yet caloric, glucose solution. Consistently, hungry mice shifted their preferences away from artificial sweeteners and in favour of glucose after experiencing glucose in a hungry state. Glucose intake was found to produce significantly greater levels of dopamine efflux compared to artificial sweetener in dorsal striatum, whereas disrupting glucose oxidation suppressed dorsal striatum dopamine efflux. Conversely, inhibiting striatal dopamine receptor signalling during glucose intake in sweet-naïve animals resulted in reduced, artificial sweetener-like intake of glucose during subsequent gluco-deprivation. Our results demonstrate that glucose oxidation controls intake levels of sweet tastants by modulating extracellular dopamine levels in dorsal striatum, and suggest that glucose utilization is one critical physiological signal involved in the control of goal-directed sweetener intake.

  15. Glucose cycling in islets from healthy and diabetic rats

    SciTech Connect

    Khan, A.; Chandramouli, V.; Ostenson, C.G.; Loew, H.L.; Landau, B.R.; Efendic, S. )

    1990-04-01

    Pancreatic islets from healthy (control) and neonatally streptozocin-induced diabetic (STZ-D) rats, a model for non-insulin-dependent diabetes mellitus, were incubated with {sup 3}H{sub 2}O and 5.5 or 16.7 mM glucose. At 5.5 mM glucose, no detectable ({sup 3}H)glucose was formed. At 16.7 mM, 2.2 patom.islet-1.h-1 of {sup 3}H was incorporated into glucose by the control islets and 5.4 patom.islet-1.h-1 by STZ-D islets. About 75% of the {sup 3}H was bound to carbon-2 of the glucose. Glucose utilization was 35.3 pmol.islet-1.h-1 by the control and 19.0 pmol.islet-1.h-1 by the STZ-D islets. Therefore, 4.5% of the glucose-6-phosphate formed by the control islets and 15.7% by the STZ-D islets was dephosphorylated. This presumably occurred in the beta-cells of the islets catalyzed by glucose-6-phosphatase. An increased glucose cycling, i.e., glucose----glucose-6-phosphate----glucose, in islets of STZ-D rats may contribute to the decreased insulin secretion found in these animals.

  16. Glucose utilization rates regulate intake levels of artificial sweeteners

    PubMed Central

    Tellez, Luis A; Ren, Xueying; Han, Wenfei; Medina, Sara; Ferreira, Jozélia G; Yeckel, Catherine W; de Araujo, Ivan E

    2013-01-01

    It is well established that animals including humans attribute greater reinforcing value to glucose-containing sugars compared to their non-caloric counterparts, generally termed ‘artificial sweeteners’. However, much remains to be determined regarding the physiological signals and brain systems mediating the attribution of greater reinforcing value to sweet solutions that contain glucose. Here we show that disruption of glucose utilization in mice produces an enduring inhibitory effect on artificial sweetener intake, an effect that did not depend on sweetness perception or aversion. Indeed, such an effect was not observed in mice presented with a less palatable, yet caloric, glucose solution. Consistently, hungry mice shifted their preferences away from artificial sweeteners and in favour of glucose after experiencing glucose in a hungry state. Glucose intake was found to produce significantly greater levels of dopamine efflux compared to artificial sweetener in dorsal striatum, whereas disrupting glucose oxidation suppressed dorsal striatum dopamine efflux. Conversely, inhibiting striatal dopamine receptor signalling during glucose intake in sweet-naïve animals resulted in reduced, artificial sweetener-like intake of glucose during subsequent gluco-deprivation. Our results demonstrate that glucose oxidation controls intake levels of sweet tastants by modulating extracellular dopamine levels in dorsal striatum, and suggest that glucose utilization is one critical physiological signal involved in the control of goal-directed sweetener intake. PMID:24060992

  17. Glucose metabolic gene expression in growth hormone transgenic coho salmon.

    PubMed

    Panserat, Stéphane; Kamalam, Biju Sam; Fournier, Jeanne; Plagnes-Juan, Elisabeth; Woodward, Krista; Devlin, Robert H

    2014-04-01

    Salmonids are generally known to be glucose intolerant. However, previous studies have shown that growth hormone (GH) transgenic coho salmon display modified nutritional regulation of glycolysis and lipogenesis compared to non-transgenic fish, suggesting the potential for better use of glucose in GH transgenic fish. To examine this in detail, GH transgenic and non-transgenic coho salmon were subjected to glucose tolerance test and subsequent metabolic assessments. After intra-peritoneal injection of 250mg/kg glucose, we analysed post-injection kinetics of glycaemia and expression of several key target genes highly involved in glucose homeostasis in muscle and liver tissues. Our data show no significant differences in plasma glucose levels during peak hyperglycaemia (3-6h after injection), demonstrating a similar glucose tolerance between transgenic and non transgenic. However, and unrelated to the hyperglycaemic episode, GH transgenic fish return to a slightly lower basal glycaemia values 24h after injection. Correspondingly, GH transgenic fish exhibited higher mRNA levels of glucokinase (GK) and glucose-6-phosphate dehydrogenase (G6PDH) in liver, and glucose transporter (GLUT4) in muscle. These data suggest that these metabolic actors may be involved in different glucose use in GH transgenic fish, which would be expected to influence the glucose challenge response. Overall, our data demonstrate that GH transgenic coho salmon may be a pertinent animal model for further study of glucose metabolism in carnivorous fish.

  18. Critical Care Glucose Point-of-Care Testing.

    PubMed

    Narla, S N; Jones, M; Hermayer, K L; Zhu, Y

    Maintaining blood glucose concentration within an acceptable range is a goal for patients with diabetes mellitus. Point-of-care glucose meters initially designed for home self-monitoring in patients with diabetes have been widely used in the hospital settings because of ease of use and quick reporting of blood glucose information. They are not only utilized for the general inpatient population but also for critically ill patients. Many factors affect the accuracy of point-of-care glucose testing, particularly in critical care settings. Inaccurate blood glucose information can result in unsafe insulin delivery which causes poor glucose control and can be fatal. Healthcare professionals should be aware of the limitations of point-of-care glucose testing. This chapter will first introduce glucose regulation in diabetes mellitus, hyperglycemia/hypoglycemia in the intensive care unit, importance of glucose control in critical care patients, and pathophysiological variables of critically ill patients that affect the accuracy of point-of-care glucose testing. Then, we will discuss currently available point-of-care glucose meters and preanalytical, analytical, and postanalytical sources of variation and error in point-of-care glucose testing.

  19. Postprandial glucose regulation and diabetic complications.

    PubMed

    Ceriello, Antonio; Hanefeld, Markolf; Leiter, Lawrence; Monnier, Louis; Moses, Alan; Owens, David; Tajima, Naoko; Tuomilehto, Jaakko

    2004-10-25

    Atherosclerotic disease accounts for much of the increased mortality and morbidity associated with type 2 diabetes. Epidemiological studies support the potential of improved glycemic control to reduce cardiovascular complications. An association between glycosylated hemoglobin (HbA(1c)) level and the risk for cardiovascular complications has frequently been reported. Most epidemiological data implicate postprandial hyperglycemia in the development of cardiovascular disease, whereas the link between fasting glycemia and diabetic complications is inconclusive. Moreover, in many studies, postprandial glycemia is a better predictor of cardiovascular risk than HbA(1c) level. Postprandial glucose may have a direct toxic effect on the vascular endothelium, mediated by oxidative stress that is independent of other cardiovascular risk factors such as hyperlipidemia. Postprandial hyperglycemia also may exert its effects through its substantial contribution to total glycemic exposure. The present review examines the hypothesis that controlling postprandial glucose level is an important strategy in the prevention of cardiovascular complications associated with diabetes.

  20. Melatonin and glucose metabolism: clinical relevance.

    PubMed

    Lardone, P J; Alvarez-Sanchez, Sanchez N; Guerrero, J M; Carrillo-Vico, A

    2014-01-01

    The role of melatonin in glucose homeostasis is an active area of investigation. There is a growing body of evidence suggesting a link between disturbances in melatonin production and impaired insulin, glucose, lipid metabolism, and antioxidant capacity. Furthermore, melatonin has been found to influence insulin secretion both in vivo and in vitro, and night-time melatonin levels are related to night-time insulin concentrations in patients with diabetes. In several recent studies, a single nucleotide polymorphism of the human melatonin receptor 1B has been described as being causally linked to an increased risk of developing type 2 diabetes. Taken together, these data suggest that endogenous as well as exogenous melatonin may play a role in diabetes and associated metabolic disturbances not only by regulating insulin secretion but also by providing protection against reactive oxygen species, considering pancreatic β-cells are particularly susceptible to oxidative stress because they possess only low-antioxidative capacity.

  1. A role for glucose in hypothermic hamsters

    NASA Technical Reports Server (NTRS)

    Resch, G. E.; Musacchia, X. J.

    1976-01-01

    Hypothermic hamsters at a rectal temperature of 7 C showed a fivefold increase in survival times from 20 to 100.5 hr when infused with glucose which maintained a blood level at about 45 mg/100 ml. A potential role for osmotic effects of the infusion was tested and eliminated. There was no improvement in survival of 3-O-methylglucose or dextran 40-infused animals. The fact that death eventually occurs even in the glucose-infused animal after about 4 days and that oxygen consumption undergoes a slow decrement in that period suggests that hypothermic survival is not wholly substrate limited. Radioactive tracer showed that localization of the C-14 was greatest in brain tissue and diaphragm, intermediate in heart and kidney, and lowest in skeletal muscle and liver. The significance of the label at sites important to respiration and circulation was presented.

  2. Accurate glucose detection in a small etalon

    NASA Astrophysics Data System (ADS)

    Martini, Joerg; Kuebler, Sebastian; Recht, Michael; Torres, Francisco; Roe, Jeffrey; Kiesel, Peter; Bruce, Richard

    2010-02-01

    We are developing a continuous glucose monitor for subcutaneous long-term implantation. This detector contains a double chamber Fabry-Perot-etalon that measures the differential refractive index (RI) between a reference and a measurement chamber at 850 nm. The etalon chambers have wavelength dependent transmission maxima which dependent linearly on the RI of their contents. An RI difference of ▵n=1.5.10-6 changes the spectral position of a transmission maximum by 1pm in our measurement. By sweeping the wavelength of a single-mode Vertical-Cavity-Surface-Emitting-Laser (VCSEL) linearly in time and detecting the maximum transmission peaks of the etalon we are able to measure the RI of a liquid. We have demonstrated accuracy of ▵n=+/-3.5.10-6 over a ▵n-range of 0 to 1.75.10-4 and an accuracy of 2% over a ▵nrange of 1.75.10-4 to 9.8.10-4. The accuracy is primarily limited by the reference measurement. The RI difference between the etalon chambers is made specific to glucose by the competitive, reversible release of Concanavalin A (ConA) from an immobilized dextran matrix. The matrix and ConA bound to it, is positioned outside the optical detection path. ConA is released from the matrix by reacting with glucose and diffuses into the optical path to change the RI in the etalon. Factors such as temperature affect the RI in measurement and detection chamber equally but do not affect the differential measurement. A typical standard deviation in RI is +/-1.4.10-6 over the range 32°C to 42°C. The detector enables an accurate glucose specific concentration measurement.

  3. Regulation of Glucose Metabolism in Pseudomonas

    PubMed Central

    Daddaoua, Abdelali; Krell, Tino; Ramos, Juan-Luis

    2009-01-01

    In Pseudomonas putida, genes for the glucose phosphorylative pathway and the Entner-Doudoroff pathway are organized in two operons; one made up of the zwf, pgl, and eda genes and another consisting of the edd, glk, gltR2, and gltS genes. Divergently with respect to the edd gene is the gap-1 gene. Expression from Pzwf, Pedd, and Pgap is modulated by HexR in response to the availability of glucose in the medium. To study the regulatory process in greater detail we purified HexR and showed that it is a monomer in solution. Electrophoretic mobility shift assays and isothermal titration calorimetry assays were done showing that HexR recognizes the Pedd, Pzwf, and Pgap-1 promoters with affinity in the nanomolar range. DNA footprinting assays identified the binding site between +30 and +1 at Pzwf, between +16 and +41 at Pedd, and between −6 and +18 at Pgap-1. Based on DNA sequence alignment of the target sites and isothermal titration calorimetry data, two monomers of HexR bind to a pseudopalindrome with a consensus sequence of 5′-TTGTN7–8ACAA-3′. Binding of the Entner-Doudoroff pathway intermediate 2-keto-3-deoxy-6-phosphogluconate to HexR released the repressor from its target operators, whereas other chemicals such as glucose, glucose 6-phosphate, and 6-phosphogluconate did not induce complex dissociation. The phosphorylated effector is likely to be recognized by a sugar isomerase domain located at the C-terminal end of HexR, whereas the helix-turn-helix DNA binding domain of HexR exhibits high similarity to proteins of the RpiR family of regulators. PMID:19506074

  4. The appropriation of glucose through primate neurodevelopment.

    PubMed

    Bauernfeind, Amy L; Babbitt, Courtney C

    2014-12-01

    The human brain is considerably larger and more energetically costly than that of other primate species. As such, discovering how human ancestors were able to provide sufficient energy to their brains is a central theme in the study of hominin evolution. However, many discussions of metabolism frequently omit the different ways in which energy, primarily glucose, is used once made available to the brain. In this review, we discuss two glucose metabolic pathways, oxidative phosphorylation and aerobic glycolysis, and their respective contributions to the energetic and anabolic budgets of the brain. While oxidative phosphorylation is a more efficient producer of energy, aerobic glycolysis contributes essential molecules for the growth of the brain and maintaining the structure of its cells. Although both pathways occur in the brain throughout the lifetime, aerobic glycolysis is a critical pathway during development, and oxidative phosphorylation is highest during adulthood. We outline how elevated levels of aerobic glycolysis may support the protracted neurodevelopmental sequence of humans compared with other primates. Finally, we review the genetic evidence for differences in metabolic function in the brains of primates and explore genes that may provide insight into how glucose metabolism may differ across species.

  5. Altered Brain Glucose Consumption in Cogan's Syndrome

    PubMed Central

    Ruffini, Livia; Ghirardini, Stella; Scarlattei, Maura; Baldari, Giorgio; Cidda, Carla; Gandolfi, Stefano A.; Orsoni, Jelka G.

    2016-01-01

    Purpose. Prospective, controlled cohort study to investigate possible alterations in brain glucose metabolism (CMRglc) in patients with Cogan's syndrome (CS). Patients and Methods. Functional mapping of the CMRglc was obtained by quantitative molecular imaging positron emission tomography, combined with computed tomography (FDG-PET/CT). The patients were divided into three clinical groups: typical CS; atypical CS (ACS); autoimmune inner ear disease (AIED). The unmatched control group (CG) consisted of subjects requiring FDG-PET/CT for an extracranial pathology. Statistical mapping searched areas of significant glucose hypometabolism in all the affected patients (DG) and in each clinical subgroup. The results were compared with those of the CG. Results. 44 patients were enrolled (DG) and assigned to the three study groups: 8 patients to the CS group; 21 patients to the ACS group; and 15 to the AIED group. Sixteen subjects formed the CG group. Areas of significant brain glucose hypometabolism were identified in all the study groups, with the largest number and extension in the DG and CS. Conclusions. This study revealed areas of significantly altered CMRglc in patients with CS (any subform) without neurologic complains and normal conventional neuroimaging. Our results suggest that FDG-PET/CT may represent a very useful tool for the global assessment of patients with Cogan's syndrome. PMID:28050276

  6. Effects of celiac superior mesenteric ganglionectomy on glucose homeostasis and hormonal changes during oral glucose tolerance testing in rats.

    PubMed

    Kumakura, Atsushi; Shikuma, Junpei; Ogihara, Norikazu; Eiki, Jun-ichi; Kanazawa, Masao; Notoya, Yōko; Kikuchi, Masatoshi; Odawara, Masato

    2013-01-01

    The liver plays an important role in maintaining glucose homeostasis in the body. In the prandial state, some of the glucose which is absorbed by the gastrointestinal tract is converted into glycogen and stored in the liver. In contrast, the liver produces glucose by glycogenolysis and gluconeogenesis while fasting. Thus, the liver contributes to maintaining blood glucose level within normoglycemic range. Glycogenesis and glycogenolysis are regulated by various mechanisms including hormones, the sympathetic and parasympathetic nervous systems and the hepatic glucose content. In this study, we examined a rat model in which the celiac superior mesenteric ganglion (CSMG) was resected. We attempted to elucidate how the celiac sympathetic nervous system is involved in regulating glucose homeostasis by assessing the effects of CSMG resection on glucose excursion during an oral glucose tolerance test, and by examining hepatic glycogen content and hepatic glycogen phosphorylase (GP) activity. On the oral glucose tolerance test, CSMG-resected rats demonstrated improved glucose tolerance and significantly increased GP activity compared with sham-operated rats, whereas there were no significant differences in insulin, glucagon or catecholamine levels between the 2 groups. These results suggest that the celiac sympathetic nervous system is involved in regulating the rate of glycogen consumption through GP activity. In conclusion, the examined rat model showed that the celiac sympathetic nervous system regulates hepatic glucose metabolism in conjunction with vagal nerve innervations and is a critical component in the maintenance of blood glucose homeostasis.

  7. Modulation of memory with septal injections of morphine and glucose: effects on extracellular glucose levels in the hippocampus.

    PubMed

    McNay, Ewan C; Canal, Clinton E; Sherwin, Robert S; Gold, Paul E

    2006-02-28

    The concentration of glucose in the extracellular fluid (ECF) of the hippocampus decreases substantially during memory testing on a hippocampus-dependent memory task. Administration of exogenous glucose, which enhances task performance, prevents this decrease, suggesting a relationship between hippocampal glucose availability and memory performance. In the present experiment, spontaneous alternation performance and task-related changes in hippocampal ECF glucose were assessed in rats after intraseptal administration of morphine, which impairs memory on a spontaneous alternation task, and after co-administration of intraseptal glucose, which attenuates that impairment. Consistent with previous findings, spontaneous alternation testing resulted in a decrease in hippocampal ECF glucose levels in control rats. However, rats that received intraseptal morphine prior to testing showed memory impairments and an absence of the task-related decrease in hippocampal ECF glucose levels. Intraseptal co-administration of glucose with morphine attenuated the memory impairment, and ECF glucose levels in the hippocampus decreased in a manner comparable to that seen in control rats. These data suggest that fluctuations in hippocampal ECF glucose levels may be a marker of mnemonic processing and support the view that decreases in extracellular glucose during memory testing reflect increased glucose demand during memory processing.

  8. Intragastric administration of allyl isothiocyanate reduces hyperglycemia in intraperitoneal glucose tolerance test (IPGTT) by enhancing blood glucose consumption in mice.

    PubMed

    Mori, Noriyuki; Kurata, Manami; Yamazaki, Hanae; Hosokawa, Hiroshi; Nadamoto, Tomonori; Inoue, Kazuo; Fushiki, Tohru

    2013-01-01

    We investigated the effects of allyl isothiocyanate (AITC) on the blood glucose levels of mice using an intraperitoneal glucose tolerance test. The intragastric administration of 25 mg/kg body weight AITC reduced the increase in blood glucose level after 2 g/kg body weight glucose was given intraperitoneally, compared with that of control mice. To elucidate the mechanism responsible for the reduction, respiratory gas analysis employing (13)C-labeled glucose was performed. The intragastrically administering AITC increased (13)CO2 emission, compared to vehicle, after intraperitoneal administration of (13)C-labeled glucose. This indicated that AITC increased the utilization of exogenously administered glucose, which was excessive glucose in the blood. To examine whether transient receptor potential (TRP) channels mediated this reduction in the blood glucose levels, we used TRPA1 and TRPV1 knockout (KO) mice. Intragastrically administering AITC reduced the increase in the blood glucose level in TRPA1 KO mice but not in TRPV1 KO mice. These findings suggest that dietary AITC might reduce the increases in blood glucose levels by increasing the utilization of excessive glucose in the blood by activating TRPV1.

  9. Time-saving screening for diabetes in patients with coronary artery disease: a report from EUROASPIRE IV

    PubMed Central

    Gyberg, Viveca; De Bacquer, Dirk; Kotseva, Kornelia; De Backer, Guy; Schnell, Oliver; Tuomilehto, Jaakko; Wood, David; Rydén, Lars

    2016-01-01

    Background WHO advocates 2-hour oral glucose tolerance test (OGTT) for detecting diabetes mellitus (DM). OGTT is the most sensitive method to detect DM in patients with coronary artery disease (CAD). Considered time consuming, the use of OGTT is unsatisfactory. A 1-hour plasma glucose (1hPG) test has not been evaluated as an alternative in patients with CAD. Objectives To create an algorithm based on glycated haemoglobin (HbA1c), fasting plasma glucose (FPG) and 1hPG limiting the need of a 2-hour plasma glucose (2hPG) in patients with CAD. Methods 951 patients with CAD without DM underwent OGTT. A 2hPG≥11.1 mmol/L was the reference for undiagnosed DM. The yield of HbA1c, FPG and 1hPG was compared with that of 2hPG. Results Mean FPG was 6.2±0.9 mmol/L, and mean HbA1c 5.8±0.4%. Based on 2hPG≥11.1 mmol/L 122 patients (13%) had DM. There was no value for the combination of HbA1c and FPG to rule out or in DM (HbA1c≥6.5%; FPG≥7.0 mmol/L). In receiver operating characteristic analysis a 1hPG≥12 mmol/L balanced sensitivity and specificity for detecting DM (both=82%; positive and negative predictive values 40% and 97%). A combination of FPG<6.5 mmol/L and 1hPG<11 mmol/L excluded 99% of DM. A combination of FPG>8.0 mmol/L and 1hPG>15 mmol/L identified 100% of patients with DM. Conclusions Based on its satisfactory accuracy to detect DM an algorithm is proposed for screening for DM in patients with CAD decreasing the need for a 2-hour OGTT by 71%. PMID:27932342

  10. Optical glucose monitoring using vertical cavity surface emitting lasers (VCSELs)

    NASA Astrophysics Data System (ADS)

    Talebi Fard, Sahba; Hofmann, Werner; Talebi Fard, Pouria; Kwok, Ezra; Amann, Markus-Christian; Chrostowski, Lukas

    2009-08-01

    Diabetes Mellitus is a common chronic disease that has become a public health issue. Continuous glucose monitoring improves patient health by stabilizing the glucose levels. Optical methods are one of the painless and promising methods that can be used for blood glucose predictions. However, having accuracies lower than what is acceptable clinically has been a major concern. Using lasers along with multivariate techniques such as Partial Least Square (PLS) can improve glucose predictions. This research involves investigations for developing a novel optical system for accurate glucose predictions, which leads to the development of a small, low power, implantable optical sensor for diabetes patients.

  11. Economics of the hydrolysis of cellulosic sludge to glucose.

    PubMed

    Mora, Sandeep; Banerjee, Sujit

    2013-08-01

    Cellulosic sludge from paper mills making bleached products can be enzymatically converted to glucose. A kinetic model that accounts for product inhibition was used to estimate the cost:benefits of the process. In the proposed scheme, the sludge is enzymatically hydrolyzed in a sequence of CSTRs, the ash separated, and the product glucose concentrated through reverse osmosis. The water recovered is mostly recycled. By far, the most important economic variable is the value of the glucose. However, even if the glucose is assumed to be of no value the avoided cost of sludge disposal approximately offsets the process costs. The approach should generate significant revenue if the glucose is valued at market.

  12. Molecular and industrial aspects of glucose isomerase.

    PubMed Central

    Bhosale, S H; Rao, M B; Deshpande, V V

    1996-01-01

    Glucose isomerase (GI) (D-xylose ketol-isomerase; EC. 5.3.1.5) catalyzes the reversible isomerization of D-glucose and D-xylose to D-fructose and D-xylulose, respectively. The enzyme has the largest market in the food industry because of its application in the production of high-fructose corn syrup (HFCS). HFCS, an equilibrium mixture of glucose and fructose, is 1.3 times sweeter than sucrose and serves as a sweetener for use by diabetics. Interconversion of xylose to xylulose by GI serves a nutritional requirement in saprophytic bacteria and has a potential application in the bioconversion of hemicellulose to ethanol. The enzyme is widely distributed in prokaryotes. Intensive research efforts are directed toward improving its suitability for industrial application. Development of microbial strains capable of utilizing xylan-containing raw materials for growth or screening for constitutive mutants of GI is expected to lead to discontinuation of the use of xylose as an inducer for the production of the enzyme. Elimination of Co2+ from the fermentation medium is desirable for avoiding health problems arising from human consumption of HFCS. Immobilization of GI provides an efficient means for its easy recovery and reuse and lowers the cost of its use. X-ray crystallographic and genetic engineering studies support a hydride shift mechanism for the action of GI. Cloning of GI in homologous as well as heterologous hosts has been carried out, with the prime aim of overproducing the enzyme and deciphering the genetic organization of individual genes (xylA, xylB, and xylR) in the xyl operon of different microorganisms. The organization of xylA and xylB seems to be highly conserved in all bacteria. The two genes are transcribed from the same strand in Escherichia coli and Bacillus and Lactobacillus species, whereas they are transcribed divergently on different strands in Streptomyces species. A comparison of the xylA sequences from several bacterial sources revealed the

  13. Amperometric Glucose Biosensor Based on Self-Assembling Glucose Oxidase on Carbon Nanotubes

    SciTech Connect

    Liu, Guodong; Lin, Yuehe

    2006-01-01

    A flow injection amperometric glucose biosensor based on electrostatic self-assembling glucose oxidase (GOx) on a carbon nanotube (CNT)-modified glassy carbon transducer is described. GOx is immobilized on the negatively charged CNT surface by alternatively assembling a cationic polydiallyldimethylammonium chloride (PDDA) layer and a GOx layer. The unique sandwich-like layer structure (PDDA/GOx/PDDA/CNT) formed by self-assembling provides a favorable microenvironment to keep the bioactivity of GOx and to prevent enzyme molecule leakage. The direct electrochemistry behavior of GOx and electrocatalysis of H2O2 on the fabricated PDDA/GOx/PDDA/CNT electrode demonstrated that such a biosensor fabrication method preserves the activity of enzyme molecules and the mechanical and electrocatalytic properties of carbon nanotubes, enabling sensitive determination of glucose. Flow injection amperometric detection of glucose is carried out at -100 mV (vs Ag/AgCl) in 0.05 M phosphate buffer solution (pH 7.4) with wide linear response range of 15 uM- 6 mM and a detection limit of 7 uM. The PDDA/GOx/PDDA/CNT/GC biosensor showed excellent properties for the sensitive determination of glucose with good reproducibility, remarkable stability, and free of interference from other co-existing electroactive species. The present methods can be applied to assemble other enzyme molecules and biological molecules, such as antibody, antigen, and DNA, to the CNT surface for wide biosensor and bioassay applications.

  14. Testing the Glucose Hypothesis among Capuchin Monkeys: Does Glucose Boost Self-Control?

    PubMed Central

    Parrish, Audrey E.; Emerson, Ishara D.; Rossettie, Mattea S.; Beran, Michael J.

    2016-01-01

    The ego-depletion hypothesis states that self-control diminishes over time and with exertion. Accordingly, the glucose hypothesis attributes this depletion of self-control resources to decreases in blood glucose levels. Research has led to mixed findings among humans and nonhuman animals, with limited evidence for such a link between glucose and self-control among closely-related nonhuman primate species, but some evidence from more distantly related species (e.g., honeybees and dogs). We tested this hypothesis in capuchin monkeys by manipulating the sugar content of a calorie-matched breakfast meal following a nocturnal fast, and then presenting each monkey with the accumulation self-control task. Monkeys were presented with food items one-by-one until the subject retrieved and ate the accumulating items, which required continual inhibition of food retrieval in the face of an increasingly desirable reward. Results indicated no relationship between self-control performance on the accumulation task and glucose ingestion levels following a fast. These results do not provide support for the glucose hypothesis of self-control among capuchin monkeys within the presented paradigm. Further research assessing self-control and its physiological correlates among closely- and distantly-related species is warranted to shed light on the mechanisms underlying self-control behavior. PMID:27527225

  15. Blood Glucose Self-Monitoring with a Long-Term Subconjunctival Glucose Sensor

    PubMed Central

    Müller, Achim Josef; Knuth, Monika; Nikolaus, Katharina Sibylle; Krivánek, Roland; Küster, Frank; Hasslacher, Christoph; Auffarth, Gerd Uwe

    2013-01-01

    Background To evaluate the feasibility of an implantable subconjunctival glucose monitoring system (SGMS) for long-term glucose monitoring, we investigated the in vivo performance of the system. Method The SGMS consists of an implantable ocular mini implant (OMI) and a handheld fluorescence photometer. A clinical study was performed on 47 diabetes patients split into two cohorts. Two different types of OMI were used, with and without a biocompatible surface coating. Duration of the study was 1 year. Correlation between capillary blood glucose and SGMS-derived interstitial fluid glucose was investigated during the first 6 months of the study. Results Both OMI types were tolerated well in the eyes of the patients. At the beginning of the study, the SGMS of both cohorts revealed a high accuracy with mean absolute relative difference (MARD) values of 7–12%. The performance of the uncoated OMIs deteriorated within 3 months of wearing time, exhibiting a MARD value of 20%. The performance of the surface-coated OMIs was preserved longer. Glucose correlation measurement with reasonable results (MARD of 14%) could be performed for up to 6 months of wear. Conclusions The biocompatible surface coating on the OMIs enabled a longer duration of action of up to 6 months compared with 3 months for uncoated implants in a clinical trial. PMID:23439157

  16. Effect of endurance training on glucose transport capacity and glucose transporter expression in rat skeletal muscle

    SciTech Connect

    Ploug, T.; Stallknecht, B.M.; Pedersen, O.; Kahn, B.B.; Ohkuwa, T.; Vinten, J.; Galbo, H. )

    1990-12-01

    The effect of 10 wk endurance swim training on 3-O-methylglucose (3-MG) uptake (at 40 mM 3-MG) in skeletal muscle was studied in the perfused rat hindquarter. Training resulted in an increase of approximately 33% for maximum insulin-stimulated 3-MG transport in fast-twitch red fibers and an increase of approximately 33% for contraction-stimulated transport in slow-twitch red fibers compared with nonexercised sedentary muscle. A fully additive effect of insulin and contractions was observed both in trained and untrained muscle. Compared with transport in control rats subjected to an almost exhaustive single exercise session the day before experiment both maximum insulin- and contraction-stimulated transport rates were increased in all muscle types in trained rats. Accordingly, the increased glucose transport capacity in trained muscle was not due to a residual effect of the last training session. Half-times for reversal of contraction-induced glucose transport were similar in trained and untrained muscles. The concentrations of mRNA for GLUT-1 (the erythrocyte-brain-Hep G2 glucose transporter) and GLUT-4 (the adipocyte-muscle glucose transporter) were increased approximately twofold by training in fast-twitch red muscle fibers. In parallel to this, Western blot demonstrated a approximately 47% increase in GLUT-1 protein and a approximately 31% increase in GLUT-4 protein. This indicates that the increases in maximum velocity for 3-MG transport in trained muscle is due to an increased number of glucose transporters.

  17. Sensitivity analysis of near-infrared glucose absorption signals: toward noninvasive blood glucose sensing

    NASA Astrophysics Data System (ADS)

    Saptari, Vidi A.; Youcef-Toumi, Kamal

    2000-11-01

    Noninvasive blood glucose monitoring is a long pursued goal in clinical diagnostic. Among several other optical methods, near infrared absorption spectroscopy is the most promising one for the noninvasive application to date. However, realization has not been achieved. A major obstacle is the low signal-to-noise ration pertinent to physiological blood glucose measurement using the near infrared absorption technique. Sensitivity analysis of aqueous glucose absorption signals was performed in the combination band region and in the first-overtone region. The analysis involved quantification of both glucose absorption signal and the corresponding spectral noise within a particular wavelength region. Glucose absorption band at 4430cm-1 (2257nm) in the combination band region was found to give an order of magnitude higher signal-to-noise ratio than the strongest band in the first-overtone region. A Fourier- filtering algorithm was applied to the raw absorbance data to remove some of the unwanted spectral variations. With simple peak-to-peak analysis to the Fourier-filtered absorbance data, repeatability of less than +/-0.5mmol/L was achieved. In addition, effects of temperature variations on the absorption spectra were studied. The effects of sample temperature were compensated with the application of the Fourier filter.

  18. Glucose enhances indolic glucosinolate biosynthesis without reducing primary sulfur assimilation

    PubMed Central

    Miao, Huiying; Cai, Congxi; Wei, Jia; Huang, Jirong; Chang, Jiaqi; Qian, Hongmei; Zhang, Xin; Zhao, Yanting; Sun, Bo; Wang, Bingliang; Wang, Qiaomei

    2016-01-01

    The effect of glucose as a signaling molecule on induction of aliphatic glucosinolate biosynthesis was reported in our former study. Here, we further investigated the regulatory mechanism of indolic glucosinolate biosynthesis by glucose in Arabidopsis. Glucose exerted a positive influence on indolic glucosinolate biosynthesis, which was demonstrated by induced accumulation of indolic glucosinolates and enhanced expression of related genes upon glucose treatment. Genetic analysis revealed that MYB34 and MYB51 were crucial in maintaining the basal indolic glucosinolate accumulation, with MYB34 being pivotal in response to glucose signaling. The increased accumulation of indolic glucosinolates and mRNA levels of MYB34, MYB51, and MYB122 caused by glucose were inhibited in the gin2-1 mutant, suggesting an important role of HXK1 in glucose-mediated induction of indolic glucosinolate biosynthesis. In contrast to what was known on the function of ABI5 in glucose-mediated aliphatic glucosinolate biosynthesis, ABI5 was not required for glucose-induced indolic glucosinolate accumulation. In addition, our results also indicated that glucose-induced glucosinolate accumulation was due to enhanced sulfur assimilation instead of directed sulfur partitioning into glucosinolate biosynthesis. Thus, our data provide new insights into molecular mechanisms underlying glucose-regulated glucosinolate biosynthesis. PMID:27549907

  19. Gliotransmission and brain glucose sensing: critical role of endozepines.

    PubMed

    Lanfray, Damien; Arthaud, Sébastien; Ouellet, Johanne; Compère, Vincent; Do Rego, Jean-Luc; Leprince, Jérôme; Lefranc, Benjamin; Castel, Hélène; Bouchard, Cynthia; Monge-Roffarello, Boris; Richard, Denis; Pelletier, Georges; Vaudry, Hubert; Tonon, Marie-Christine; Morin, Fabrice

    2013-03-01

    Hypothalamic glucose sensing is involved in the control of feeding behavior and peripheral glucose homeostasis, and glial cells are suggested to play an important role in this process. Diazepam-binding inhibitor (DBI) and its processing product the octadecaneuropeptide (ODN), collectively named endozepines, are secreted by astroglia, and ODN is a potent anorexigenic factor. Therefore, we investigated the involvement of endozepines in brain glucose sensing. First, we showed that intracerebroventricular administration of glucose in rats increases DBI expression in hypothalamic glial-like tanycytes. We then demonstrated that glucose stimulates endozepine secretion from hypothalamic explants. Feeding experiments indicate that the anorexigenic effect of central administration of glucose was blunted by coinjection of an ODN antagonist. Conversely, the hyperphagic response elicited by central glucoprivation was suppressed by an ODN agonist. The anorexigenic effects of centrally injected glucose or ODN agonist were suppressed by blockade of the melanocortin-3/4 receptors, suggesting that glucose sensing involves endozepinergic control of the melanocortin pathway. Finally, we found that brain endozepines modulate blood glucose levels, suggesting their involvement in a feedback loop controlling whole-body glucose homeostasis. Collectively, these data indicate that endozepines are a critical relay in brain glucose sensing and potentially new targets in treatment of metabolic disorders.

  20. Evolution of glucose utilization: Glucokinase and glucokinase regulator protein

    PubMed Central

    Irwin, David M.; Tan, Huanran

    2014-01-01

    Glucose is an essential nutrient that must be distributed throughout the body to provide energy to sustain physiological functions. Glucose is delivered to distant tissues via be blood stream, and complex systems have evolved to maintain the levels of glucose within a narrow physiological range. Phosphorylation of glucose, by glucokinase, is an essential component of glucose homeostasis, both from the regulatory and metabolic point-of-view. Here we review the evolution of glucose utilization from the perspective of glucokinase. We discuss the origin of glucokinase, its evolution within the hexokinase gene family, and the evolution of its interacting regulatory partner, glucokinase regulatory protein (GCKR). Evolution of the structure and sequence of both glucokinase and GCKR have been necessary to optimize glucokinase in its role in glucose metabolism. PMID:24075984

  1. Effect of different glucose concentrations on proteome of Saccharomyces cerevisiae.

    PubMed

    Guidi, Francesca; Francesca, Guidi; Magherini, Francesca; Francesca, Magherini; Gamberi, Tania; Tania, Gamberi; Borro, Marina; Marina, Borro; Simmaco, Maurizio; Maurizio, Simmaco; Modesti, Alessandra; Alessandra, Modesti

    2010-07-01

    We performed a proteomic study to understand how Saccharomyces cerevisiae adapts its metabolism during the exponential growth on three different concentrations of glucose; this information will be necessary to understand yeast carbon metabolism in different environments. We induced a natural diauxic shift by growing yeast cells in glucose restriction thus having a fast and complete glucose exhaustion. We noticed differential expressions of groups of proteins. Cells in high glucose have a decreased growth rate during the initial phase of fermentation; in glucose restriction and in high glucose we found an over-expression of a protein (Peroxiredoxin) involved in protection against oxidative stress insult. The information obtained in our study validates the application of a proteomic approach for the identification of the molecular bases of environmental variations such as fermentation in high glucose and during a naturally induced diauxic shift.

  2. Flurbiprofen Ameliorates Glucose Deprivation-Induced Leptin Resistance

    PubMed Central

    Hosoi, Toru; Suyama, Yuka; Kayano, Takaaki; Ozawa, Koichiro

    2016-01-01

    Leptin resistance is one of the mechanisms involved in the pathophysiology of obesity. The present study showed that glucose deprivation inhibited leptin-induced phosphorylation of signal transducer and activator of transcription 3 (STAT3) and signal transducer and activator of transcription 5 (STAT5) in neuronal cells. Flurbiprofen reversed glucose deprivation-mediated attenuation of STAT3, but not STAT5 activation, in leptin-treated cells. Glucose deprivation increased C/EBP-homologous protein and glucose regulated protein 78 induction, indicating the activation of unfolded protein responses (UPR). Flurbiprofen did not affect the glucose deprivation-induced activation of UPR, but did attenuate the glucose deprivation-mediated induction of AMP-activated protein kinase phosphorylation. Flurbiprofen may ameliorate glucose deprivation-induced leptin resistance in neuronal cells. PMID:27746736

  3. Specificity of noninvasive blood glucose monitoring with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Larin, Kirill V.; Ashitkov, Taras V.; Motamedi, Massoud; Esenaliev, Rinat O.

    2003-07-01

    Management of diabetic disease requires frequent monitoring of blood glucose concentration. Development of a noninvasive technique capable of reliable and sensitive monitoring of blood glucose concentration would considerably improve quality of life of diabetic patients and reduce mortality associated with this disease. Recently, we proposed to use Optical Coherence Tomography (OCT) technique for noninvasive glucose monitoring. In this paper, we tested in animals several aspects of specificity of noninvasive blood glucose monitoring with the OCT technique. Influence of temperature and tissue heterogeneity on the OCT signal profile is experimentally studied in this paper. We also theoretically investigated the changes in tissue scattering induced by variation of concentration of glucose and other osmolytes. Obtained results suggest that although several physical and chemical agents could potentially interfere with blood glucose concentration measurements using the OCT technique, their effect is smaller compared to that of glucose under normal physiological conditions.

  4. Role of Adrenergic Receptors in Glucose, Fructose and Galactose-Induced Increases in Intestinal Glucose Uptake in Dogs.

    PubMed

    Salman, T M; Alada, A R A; Oyebola, D D O

    2014-12-29

    The study investigated the role of adrenergic receptors in glucose, fructose-, and galactose- induced increases in intestinal glucose uptake. Experiments were carried out on fasted male anaesthetized Nigerian local dogs divided into seven groups (with five dogs per group). Group I dogs were administered normal saline and served as control. Dogs in groups II, III and IV were intravenously infused with glucose (1.1 mg/kg/min), fructose (1.1 mg/kg/min) and galactose (1.1 mg/kg/min) respectively. Another three groups, V, VI and VII were pretreated with prazosin (0.2mg/kg), propranolol (0.5mg/kg) or a combination of prazosin (0.2mg/kg) and propranolol (0.5mg/kg) followed by glucose infusion, frutose infusion or galactose infusion respectively. Through a midline laparatomy, the upper jejunum was cannulated for blood flow measurement and blood samples were obtained for measurement of glucose content of the arterial blood and venous blood from the upper jejunal segment. Glucose uptake was calculated as the product of jejunal blood flow and the difference between arterial and venous glucose levels (A-V glucose). The results showed that pretreatment of the animal with prazosin had no effect on glucose and galactose induced increases in glucose uptake. However, pretreatment with propranolol completely abolished glucose, fructose and galactose-induced increases in intestinal glucose uptake. Prazosin also significantly reduced galactose-induced increase in intestinal glucose uptake. The results suggest that the increases in intestinal glucose uptake induced by glucose and fructose are mediated mostly by beta adrenergic receptors while that of galactose is mediated by both alpha and beta adrenergic receptors.

  5. Convergence of hepatoportal glucose-sensitive afferent signals to glucose-sensitive units within the nucleus of the solitary tract.

    PubMed

    Adachi, A; Shimizu, N; Oomura, Y; Kobáshi, M

    1984-05-04

    Units which are activated by ascending impulses from the liver within the nucleus of the solitary tract (NTS) were identified by electrical stimulation delivered to the hepatic branch of the vagus. Responses of descending units were eliminated by a collision test. The units which showed decreased firing rates during portal infusion of isotonic glucose solution were also glucose-sensitive so that they showed decreased firing rates during topical application of glucose by means of micro-electro-osmotic techniques. It is concluded that glucose-sensitive neurons exist within the NTS and also that they are functionally linked with hepatoportal glucose-sensitive afferent units.

  6. Seasonal variations in plasma glucose and insulin concentrations after glucose loading in the edible dormouse (Glis glis L.).

    PubMed

    Castex, C; Donnio, R; Sutter, B C

    1979-01-01

    Glucose tolerance tests made in the Edible dormouse showed annual variations in B cell secretory capacity, associated with glucose tolerance changes. 1. During autumn and winter, the B cell is sensitive to glucose, and insulin regulates the high peripheral consumption of this hexose. 2. At the beginning of spring, insulin secretion decreases and glucose tolerance is impaired. In June, the B cell response si low or absent and a poor tolerance to glucose still persists. 3. The variations in B cell activity can be related to changing energy requirements during the year.

  7. CGM Versus FGM; or, Continuous Glucose Monitoring Is Not Flash Glucose Monitoring.

    PubMed

    Heinemann, Lutz; Freckmann, Guido

    2015-09-01

    It remains to be seen as to what share of the market FGM will achieve if the manufacturer can supply any amount desired.Will a significant portion of the glucose monitoring market then be taken over by FGM? The availability of FGM as anew option for glucose monitoring can basically be evaluated positively and it does indeed clearly show the benefit of“more information” on the glucose trend. The relatively low price for glucose monitoring using FGM and the unusual market introduction (not first via the National Association of Statutory Health Insurance Funds, as was the case with CGM) have given increased attention to the use of more glucose information. It will likely take a certain amount of time before other providers are able to bring different FGM systems to the market.The option of coupling a CGM system with an insulin pump offers the perspective of an automated insulin application,that is, a closed-loop system. Such systems are currently being tested under everyday conditions, although it is not possible to predict when they will actually reach the market.There are, however, such couplings where algorithms are responsible for shutting off insulin delivery when the glucose concentration reaches a defined level or if it will be reached in the foreseeable future. This significantly helps prevent hypoglycemia. These options are only available with CGM. The aim of this commentary is to present the differences between CGM and FGM, including the advantages and disadvantages of both approaches. We see significant benefits in both options based on the different positioning of the approaches and the different user groups.

  8. Genetic variation in GIPR influences the glucose and insulin responses to an oral glucose challenge

    PubMed Central

    Saxena, Richa; Hivert, Marie-France; Langenberg, Claudia; Tanaka, Toshiko; Pankow, James S; Vollenweider, Peter; Lyssenko, Valeriya; Bouatia-Naji, Nabila; Dupuis, Josée; Jackson, Anne U; Kao, W H Linda; Li, Man; Glazer, Nicole L; Manning, Alisa K; Luan, Jian’an; Stringham, Heather M; Prokopenko, Inga; Johnson, Toby; Grarup, Niels; Boesgaard, Trine W; Lecoeur, Cécile; Shrader, Peter; O’Connell, Jeffrey; Ingelsson, Erik; Couper, David J; Rice, Kenneth; Song, Kijoung; Andreasen, Camilla H; Dina, Christian; Köttgen, Anna; Le Bacquer, Olivier; Pattou, François; Taneera, Jalal; Steinthorsdottir, Valgerdur; Rybin, Denis; Ardlie, Kristin; Sampson, Michael; Qi, Lu; van Hoek, Mandy; Weedon, Michael N; Aulchenko, Yurii S; Voight, Benjamin F; Grallert, Harald; Balkau, Beverley; Bergman, Richard N; Bielinski, Suzette J; Bonnefond, Amelie; Bonnycastle, Lori L; Borch-Johnsen, Knut; Böttcher, Yvonne; Brunner, Eric; Buchanan, Thomas A; Bumpstead, Suzannah J; Cavalcanti-Proença, Christine; Charpentier, Guillaume; Chen, Yii-Der Ida; Chines, Peter S; Collins, Francis S; Cornelis, Marilyn; Crawford, Gabriel J; Delplanque, Jerome; Doney, Alex; Egan, Josephine M; Erdos, Michael R; Firmann, Mathieu; Forouhi, Nita G; Fox, Caroline S; Goodarzi, Mark O; Graessler, Jürgen; Hingorani, Aroon; Isomaa, Bo; Jørgensen, Torben; Kivimaki, Mika; Kovacs, Peter; Krohn, Knut; Kumari, Meena; Lauritzen, Torsten; Lévy-Marchal, Claire; Mayor, Vladimir; McAteer, Jarred B; Meyre, David; Mitchell, Braxton D; Mohlke, Karen L; Morken, Mario A; Narisu, Narisu; Palmer, Colin N A; Pakyz, Ruth; Pascoe, Laura; Payne, Felicity; Pearson, Daniel; Rathmann, Wolfgang; Sandbaek, Annelli; Sayer, Avan Aihie; Scott, Laura J; Sharp, Stephen J; Sijbrands, Eric; Singleton, Andrew; Siscovick, David S; Smith, Nicholas L; Sparsø, Thomas; Swift, Amy J; Syddall, Holly; Thorleifsson, Gudmar; Tönjes, Anke; Tuomi, Tiinamaija; Tuomilehto, Jaakko; Valle, Timo T; Waeber, Gérard; Walley, Andrew; Waterworth, Dawn M; Zeggini, Eleftheria; Zhao, Jing Hua; Illig, Thomas; Wichmann, H Erich; Wilson, James F; van Duijn, Cornelia; Hu, Frank B; Morris, Andrew D; Frayling, Timothy M; Hattersley, Andrew T; Thorsteinsdottir, Unnur; Stefansson, Kari; Nilsson, Peter; Syvänen, Ann-Christine; Shuldiner, Alan R; Walker, Mark; Bornstein, Stefan R; Schwarz, Peter; Williams, Gordon H; Nathan, David M; Kuusisto, Johanna; Laakso, Markku; Cooper, Cyrus; Marmot, Michael; Ferrucci, Luigi; Mooser, Vincent; Stumvoll, Michael; Loos, Ruth J F; Altshuler, David; Psaty, Bruce M; Rotter, Jerome I; Boerwinkle, Eric; Hansen, Torben; Pedersen, Oluf; Florez, Jose C; McCarthy, Mark I; Boehnke, Michael; Barroso, Inês; Sladek, Robert; Froguel, Philippe; Meigs, James B; Groop, Leif; Wareham, Nicholas J; Watanabe, Richard M

    2010-01-01

    Glucose levels 2 h after an oral glucose challenge are a clinical measure of glucose tolerance used in the diagnosis of type 2 diabetes. We report a meta-analysis of nine genome-wide association studies (n = 15,234 nondiabetic individuals) and a follow-up of 29 independent loci (n = 6,958–30,620). We identify variants at the GIPR locus associated with 2-h glucose level (rs10423928, β (s.e.m.) = 0.09 (0.01) mmol/l per A allele, P = 2.0 × 10−15). The GIPR A-allele carriers also showed decreased insulin secretion (n = 22,492; insulinogenic index, P = 1.0 × 10−17; ratio of insulin to glucose area under the curve, P = 1.3 × 10−16) and diminished incretin effect (n = 804; P = 4.3 × 10−4). We also identified variants at ADCY5 (rs2877716, P = 4.2 × 10−16), VPS13C (rs17271305, P = 4.1 × 10−8), GCKR (rs1260326, P = 7.1 × 10−11) and TCF7L2 (rs7903146, P = 4.2 × 10−10) associated with 2-h glucose. Of the three newly implicated loci (GIPR, ADCY5 and VPS13C), only ADCY5 was found to be associated with type 2 diabetes in collaborating studies (n = 35,869 cases, 89,798 controls, OR = 1.12, 95% CI 1.09–1.15, P = 4.8 × 10−18). PMID:20081857

  9. Effects of glucose and insulin administration on glucose transporter expression in the North Pacific spiny dogfish (Squalus suckleyi).

    PubMed

    Deck, Courtney A; Gary Anderson, W; Walsh, Patrick J

    2017-01-16

    Elasmobranchs (sharks, skates, and rays) are a primarily carnivorous group of fish, consuming few carbohydrates. Further, they tend to exhibit delayed responses to glucose and insulin administration in vivo relative to mammals, leading to a presumption of glucose-intolerance. To investigate the glucoregulatory capabilities of the spiny dogfish (Squalus suckleyi), plasma glucose concentration, muscle and liver glycogen content, and glucose transporter (glut1 and 4) mRNA levels were measured following intra-arterial administration of bovine insulin (10ngkg(-1)) or an approximate doubling of fasting plasma glucose concentration. Within 6h, following glucose administration, approximately half of the introduced glucose load had been cleared, with control levels being restored by 24h post-injection. It was determined that plasma clearance was due in part to increased uptake by the tissues as muscle and liver glycogen content increased significantly, correlating with an upregulation of glut mRNA levels. Following administration of bovine insulin, plasma glucose steadily decreased through 18h before returning toward control levels. Observed decreases in plasma glucose following insulin injection were, however, relatively minor, and no increases in tissue glycogen content were observed. glut4 and glycogen synthase mRNA levels did significantly increase in the muscle in response to insulin, but no changes occurred in the liver. The responses observed mimic what occurs in mammals and teleosts, thus suggesting a conserved mechanism for glucose homeostasis in vertebrates and a high degree of glucose tolerance in these predominantly carnivorous fish.

  10. Quantifying the contribution of the liver to glucose homeostasis: a detailed kinetic model of human hepatic glucose metabolism.

    PubMed

    König, Matthias; Bulik, Sascha; Holzhütter, Hermann-Georg

    2012-01-01

    Despite the crucial role of the liver in glucose homeostasis, a detailed mathematical model of human hepatic glucose metabolism is lacking so far. Here we present a detailed kinetic model of glycolysis, gluconeogenesis and glycogen metabolism in human hepatocytes integrated with the hormonal control of these pathways by insulin, glucagon and epinephrine. Model simulations are in good agreement with experimental data on (i) the quantitative contributions of glycolysis, gluconeogenesis, and glycogen metabolism to hepatic glucose production and hepatic glucose utilization under varying physiological states. (ii) the time courses of postprandial glycogen storage as well as glycogen depletion in overnight fasting and short term fasting (iii) the switch from net hepatic glucose production under hypoglycemia to net hepatic glucose utilization under hyperglycemia essential for glucose homeostasis (iv) hormone perturbations of hepatic glucose metabolism. Response analysis reveals an extra high capacity of the liver to counteract changes of plasma glucose level below 5 mM (hypoglycemia) and above 7.5 mM (hyperglycemia). Our model may serve as an important module of a whole-body model of human glucose metabolism and as a valuable tool for understanding the role of the liver in glucose homeostasis under normal conditions and in diseases like diabetes or glycogen storage diseases.

  11. The low affinity glucose transporter HxtB is also involved in glucose signalling and metabolism in Aspergillus nidulans.

    PubMed

    Dos Reis, Thaila Fernanda; Nitsche, Benjamin M; de Lima, Pollyne Borborema Almeida; de Assis, Leandro José; Mellado, Laura; Harris, Steven D; Meyer, Vera; Dos Santos, Renato A Corrêa; Riaño-Pachón, Diego M; Ries, Laure Nicolas Annick; Goldman, Gustavo H

    2017-03-31

    One of the drawbacks during second-generation biofuel production from plant lignocellulosic biomass is the accumulation of glucose, the preferred carbon source of microorganisms, which causes the repression of hydrolytic enzyme secretion by industrially relevant filamentous fungi. Glucose sensing, subsequent transport and cellular signalling pathways have been barely elucidated in these organisms. This study therefore characterized the transcriptional response of the filamentous fungus Aspergillus nidulans to the presence of high and low glucose concentrations under continuous chemostat cultivation with the aim to identify novel factors involved in glucose sensing and signalling. Several transcription factor- and transporter-encoding genes were identified as being differentially regulated, including the previously characterized glucose and xylose transporter HxtB. HxtB was confirmed to be a low affinity glucose transporter, localizing to the plasma membrane under low- and high-glucose conditions. Furthermore, HxtB was shown to be involved in conidiation-related processes and may play a role in downstream glucose signalling. A gene predicted to encode the protein kinase PskA was also identified as being important for glucose metabolism. This study identified several proteins with predicted roles in glucose metabolic processes and provides a foundation for further investigation into the response of biotechnologically important filamentous fungi to glucose.

  12. The low affinity glucose transporter HxtB is also involved in glucose signalling and metabolism in Aspergillus nidulans

    PubMed Central

    dos Reis, Thaila Fernanda; Nitsche, Benjamin M.; de Lima, Pollyne Borborema Almeida; de Assis, Leandro José; Mellado, Laura; Harris, Steven D.; Meyer, Vera; dos Santos, Renato A. Corrêa; Riaño-Pachón, Diego M.; Ries, Laure Nicolas Annick; Goldman, Gustavo H.

    2017-01-01

    One of the drawbacks during second-generation biofuel production from plant lignocellulosic biomass is the accumulation of glucose, the preferred carbon source of microorganisms, which causes the repression of hydrolytic enzyme secretion by industrially relevant filamentous fungi. Glucose sensing, subsequent transport and cellular signalling pathways have been barely elucidated in these organisms. This study therefore characterized the transcriptional response of the filamentous fungus Aspergillus nidulans to the presence of high and low glucose concentrations under continuous chemostat cultivation with the aim to identify novel factors involved in glucose sensing and signalling. Several transcription factor- and transporter-encoding genes were identified as being differentially regulated, including the previously characterized glucose and xylose transporter HxtB. HxtB was confirmed to be a low affinity glucose transporter, localizing to the plasma membrane under low- and high-glucose conditions. Furthermore, HxtB was shown to be involved in conidiation-related processes and may play a role in downstream glucose signalling. A gene predicted to encode the protein kinase PskA was also identified as being important for glucose metabolism. This study identified several proteins with predicted roles in glucose metabolic processes and provides a foundation for further investigation into the response of biotechnologically important filamentous fungi to glucose. PMID:28361917

  13. Recommendations for Standardizing Glucose Reporting and Analysis to Optimize Clinical Decision Making in Diabetes: The Ambulatory Glucose Profile

    PubMed Central

    Bergenstal, Richard M.; Ahmann, Andrew J.; Bailey, Timothy; Beck, Roy W.; Bissen, Joan; Buckingham, Bruce; Deeb, Larry; Dolin, Robert H.; Garg, Satish K.; Goland, Robin; Hirsch, Irl B.; Klonoff, David C.; Kruger, Davida F.; Matfin, Glenn; Mazze, Roger S.; Olson, Beth A.; Parkin, Christopher; Peters, Anne; Powers, Margaret A.; Rodriguez, Henry; Southerland, Phil; Strock, Ellie S.; Tamborlane, William; Wesley, David M.

    2013-01-01

    Underutilization of glucose data and lack of easy and standardized glucose data collection, analysis, visualization, and guided clinical decision making are key contributors to poor glycemic control among individuals with type 1 diabetes mellitus. An expert panel of diabetes specialists, facilitated by the International Diabetes Center and sponsored by the Helmsley Charitable Trust, met in 2012 to discuss recommendations for standardizing the analysis and presentation of glucose monitoring data, with the initial focus on data derived from continuous glucose monitoring systems. The panel members were introduced to a universal software report, the Ambulatory Glucose Profile, and asked to provide feedback on its content and functionality, both as a research tool and in clinical settings. This article provides a summary of the topics and issues discussed during the meeting and presents recommendations from the expert panel regarding the need to standardize glucose profile summary metrics and the value of a uniform glucose report to aid clinicians, researchers, and patients. PMID:23567014

  14. Dynamics of the reaction glucose-catalase-glucose oxidase-hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Číp, M.; Schreiberová, L.; Schreiber, I.

    2011-12-01

    Glucose-catalase-glucose oxidase-hydrogen peroxide reaction is one of the few known enzymatic systems studied in vitro in the field of nonlinear chemical dynamics. This reaction belongs to the family of oscillatory enzymatic reactions, which form a natural basis of oscillations in biological systems. A parametric study of dependence on mixing, temperature and initial concentrations of components in a batch stirred reactor was carried out. A newly proposed mathematical model of the reaction conforms to the obtained experimental data. Results of our experiments and simulations hint at further directions of research of non-linear dynamics in this reaction.

  15. Toward an Injectable Continuous Osmotic Glucose Sensor

    PubMed Central

    Johannessen, Erik; Krushinitskaya, Olga; Sokolov, Andrey; Philipp, Häfliger; Hoogerwerf, Arno; Hinderling, Christian; Kautio, Kari; Lenkkeri, Jaakko; Strömmer, Esko; Kondratyev, Vasily; Tønnessen, Tor Inge; Mollnes, Tom Eirik; Jakobsen, Henrik; Zimmer, Even; Akselsen, Bengt

    2010-01-01

    Background The growing pandemic of diabetes mellitus places a stringent social and economic burden on the society. A tight glycemic control circumvents the detrimental effects, but the prerogative is the development of new more effective tools capable of longterm tracking of blood glucose (BG) in vivo. Such discontinuous sensor technologies will benefit from an unprecedented marked potential as well as reducing the current life expectancy gap of eight years as part of a therapeutic regime. Method A sensor technology based on osmotic pressure incorporates a reversible competitive affinity assay performing glucose-specific recognition. An absolute change in particles generates a pressure that is proportional to the glucose concentration. An integrated pressure transducer and components developed from the silicon micro- and nanofabrication industry translate this pressure into BG data. Results An in vitro model based on a 3.6 × 8.7 mm large pill-shaped implant is equipped with a nanoporous membrane holding 4–6 nm large pores. The affinity assay offers a dynamic range of 36–720 mg/dl with a resolution of ±16 mg/dl. An integrated 1 × 1 mm2 large control chip samples the sensor signals for data processing and transmission back to the reader at a total power consumption of 76 µW. Conclusions Current studies have demonstrated the design, layout, and performance of a prototype osmotic sensor in vitro using an affinity assay solution for up to four weeks. The small physical size conforms to an injectable device, forming the basis of a conceptual monitor that offers a tight glycemic control of BG. PMID:20663452

  16. Astrocytic Insulin Signaling Couples Brain Glucose Uptake with Nutrient Availability.

    PubMed

    García-Cáceres, Cristina; Quarta, Carmelo; Varela, Luis; Gao, Yuanqing; Gruber, Tim; Legutko, Beata; Jastroch, Martin; Johansson, Pia; Ninkovic, Jovica; Yi, Chun-Xia; Le Thuc, Ophelia; Szigeti-Buck, Klara; Cai, Weikang; Meyer, Carola W; Pfluger, Paul T; Fernandez, Ana M; Luquet, Serge; Woods, Stephen C; Torres-Alemán, Ignacio; Kahn, C Ronald; Götz, Magdalena; Horvath, Tamas L; Tschöp, Matthias H

    2016-08-11

    We report that astrocytic insulin signaling co-regulates hypothalamic glucose sensing and systemic glucose metabolism. Postnatal ablation of insulin receptors (IRs) in glial fibrillary acidic protein (GFAP)-expressing cells affects hypothalamic astrocyte morphology, mitochondrial function, and circuit connectivity. Accordingly, astrocytic IR ablation reduces glucose-induced activation of hypothalamic pro-opio-melanocortin (POMC) neurons and impairs physiological responses to changes in glucose availability. Hypothalamus-specific knockout of astrocytic IRs, as well as postnatal ablation by targeting glutamate aspartate transporter (GLAST)-expressing cells, replicates such alterations. A normal response to altering directly CNS glucose levels in mice lacking astrocytic IRs indicates a role in glucose transport across the blood-brain barrier (BBB). This was confirmed in vivo in GFAP-IR KO mice by using positron emission tomography and glucose monitoring in cerebral spinal fluid. We conclude that insulin signaling in hypothalamic astrocytes co-controls CNS glucose sensing and systemic glucose metabolism via regulation of glucose uptake across the BBB.

  17. Characterization of mammalian glucose transport proteins using photoaffinity labeling techniques

    SciTech Connect

    Wadzinski, B.E.

    1989-01-01

    A carrier-free radioiodinated phenylazide derivative of forskolin, 3-iodo-4-azidophenethylamido-7-O-succinyl-deacetyl-forskolin (({sup 125}I)IAPS-forskolin), has been shown to be a highly selective photoaffinity probe for the human erythrocyte glucose transported and the glucose transport proteins found in several mammalian tissues and cultured cells where the glucose transport protein is present at a low concentration. The photoincorporation of ({sup 125}I)IAPS-forskolin into these glucose transporters was blocked by D- (but not L-) glucose, cytochalasin B, and forskolin. In addition to labeling the mammalian glucose transport proteins, ({sup 125}I)IAPS-forskolin also labeled the L-arabinose transporter from E. coli. In muscle and adipose tissues, glucose transport is markedly increased in response to insulin. ({sup 125}I)IAPS-forskolin was shown to selectivity tag the glucose transporter in membranes derived from these cells. In addition, the covalent derivatization of the transport protein in subcellular fractions of the adipocyte has provided a means to study the hormonal regulation of glucose transport. ({sup 125}I)IAPS-forskolin has also been used to label the purified human erythrocyte glucose transporter. The site of insertion has therefore been localized by analysis of the radiolabeled peptides which were produced following chemical and proteolytic digestion of the labeled transport protein.

  18. Atorvastatin delays the glucose clearance rate in hypercholesterolemic rabbits.

    PubMed

    Cheng, Daxin; Wang, Yanli; Gao, Shoucui; Wang, Xiaojing; Sun, Wentao; Bai, Liang; Cheng, Gong; Chu, Yonglie; Zhao, Sihai; Liu, Enqi

    2015-05-01

    The administration of statin might increase the risk of new-onset diabetes in hypercholesterolemic patients based on the recent clinical evidence. However, the causal relationship must be clarified and confirmed in animal experiments. Therefore, we mimicked hypercholesterolemia by feeding rabbits a high-cholesterol diet (HCD) and performed 16 weeks of atorvastatin administration to investigate the effect of statin on glucose metabolism. The intravenous glucose tolerance test showed that plasma glucose levels in the statin-treated rabbits were consistently higher and that there was a slower rate of glucose clearance from the blood than in HCD rabbits. The incremental area under the curve for glucose in the statin-treated rabbits was also significantly larger than in the HCD rabbits. However, there was no significant difference between the two groups in the intravenous insulin tolerance test. The glucose-lowering ability of exogenous insulin was not impaired by statin treatment in hypercholesterolemic rabbits. The administration of a single dose of statin did not affect glucose metabolism in normal rabbits. The statin also significantly increased the levels of high-density lipoprotein cholesterol, alanine aminotransferase and aspartate transaminase and decreased plasma levels of total cholesterol, triglycerides and low-density lipoprotein cholesterol in the hypercholesterolemic rabbits, whereas it did not affect plasma levels of glucose and insulin. The current results showed that atorvastatin treatment resulted in a significant delay of glucose clearance in hypercholesterolemic rabbits, and this rabbit model could be suitable for studying the effects of statin on glucose metabolism.

  19. Effect of anesthesia on glucose production and utilization in rats

    SciTech Connect

    Penicaud, L.; Ferre, P.; Kande, J.; Leturque, A.; Issad, T.; Girard, J.

    1987-03-01

    This study was undertaken to determine the effects of pentobarbital anesthesia (50 mg/kg ip) on glucose kinetics and individual tissue glucose utilization in vivo, in chronically catheterized rats. Glucose turnover studies were carried out using (3-/sup 3/H) glucose as tracer. A transient hyperglycemia and an increased glucose production were observed 3 min after induction of anesthesia. However, 40 min after induction of anesthesia, glycemia returned to the level observed in awake animals, whereas glucose turnover was decreased by 30% as compared with unanesthetized rats. These results are discussed with regard to the variations observed in plasma insulin, glucagon, and catecholamine levels. Glucose utilization by individual tissues was studied by the 2-(1-/sup 3/H) deoxyglucose technique. A four- to fivefold decrease in glucose utilization was observed in postural muscles (soleus and adductor longus), while in other nonpostural muscles (epitrochlearis, tibialis anterior, extensor digitorum longus, and diaphragm) and other tissues (white and brown adipose tissues) anesthesia did not modify the rate of glucose utilization. A decrease in glucose utilization was also observed in the brain.

  20. Alcohol from glucose without using yeast

    SciTech Connect

    Not Available

    1980-12-17

    Researchers at the Oak Ridge National Laboratory (Oak Ridge, Tenn.) have demonstrated a continuous way to make ethanol by bacterial fermentation of glucose using the bacterium Zymomonas mobilis. The bacterium has several advantages over yeasts and can be maintained at higher cell densities in immobilized-cell reactors. Nevertheless, even the most ethanol-tolerant strains of Zymomonas can't survive a concentration greater than 15%, and further studies are required before the bacterium can be used in large-scale alcohol- from-biomass schemes.

  1. Placental glucose dehydrogenase polymorphism in Koreans.

    PubMed

    Kim, Y J; Paik, S G; Park, H Y

    1994-12-01

    The genetic polymorphism of placental glucose dehydrogenase (GDH) was investigated in 300 Korean placentae using horizontal starch gel electrophoresis. The allele frequencies for GDH1, GDH2 and GDH3 were 0.537, 0.440 and 0.005, respectively, which were similar to those in Japanese. We also observed an anodal allele which was similar to the GDH4 originally reported in Chinese populations at a low frequency of 0.015. An additional new cathodal allele (named GDH6) was observed in the present study with a very low frequency of 0.003.

  2. In vivo metabolic response of glucose to dichloroacetate in humans.

    PubMed

    Brown, J A; Gore, D C

    1996-03-01

    Hyperglycemia is common in severely ill patients and is related principally to an increase in glucose production. Dichloroacetate (DCA), which is known to increase the rate of pyruvate oxidation, has been shown to lower plasma glucose concentrations in normal fasting subjects and in diabetics and thus may be efficacious in treating stress induced hyperglycemia. However, the mechanism by which DCA lowers the plasma glucose concentration in humans has not been elucidated. To examine the human in vivo metabolic alterations induced by DCA, six fasting volunteers were infused with 6,6-D2-glucose and indirect calorimetry was performed prior to and following DCA administration. Glucose, lactate, and alanine net balance across the leg were also quantitated. Following DCA administration, plasma glucose concentrations decreased by 9% due to a proportional decrease in the rate of glucose production (P < 0.05). DCA had no affect on glucose clearance or leg net balance; however, the rate of glucose oxidation increased by 24% from baseline (P < 0.05). This increase in glucose oxidation without a compensatory change in peripheral glucose consumption suggests an improved efficiency in peripheral glucose utilization induced by DCA. Plasma concentrations of lactate and alanine were also lowered by DCA (56% for lactate, 66% for alanine, P < 0.05) without a significant alteration in leg net balance. These results suggest that DCA may decrease gluconeogenesis by limiting the availability of the precursor substrates lactate and alanine. Thus dichloroacetate may be an appropriate alternative to insulin in correcting mild elevations in plasma glucose concentrations. Furthermore, DCA may be especially effective in severely ill patients where hyperglycemia is largely due to increases in gluconeogenesis.

  3. DENSITY FUNCTIONAL CALCULATION OF ENERGIES AND VIBRATIONAL FREQUENCIES OF GLUCOSE AND GLUCOSE-WATER COMPLEXES: WATER PLACEMENT AND GLUCOSE CONFORMATIONAL EFFECTS ON THE CALCULATED INFRARED SPECTRUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structures and energies of glucose and glucose monohydrates have been calculated at the B3LYP/6-311++G** level of theory. Both the alpha and beta anomers were studied, with all possible combinations of hydroxymethyl rotamer (gg, gt, or tg) and hydroxyl orientation (clockwise or counter-clockwis...

  4. SY 10-1 RENAL GLUCOSE HANDLING AND SGLT2.

    PubMed

    Poudel, Resham

    2016-09-01

    The kidneys maintain glucose homeostasis through its utilization, gluconeogenesis, and reabsorption. Glucose is freely filtered and reabsorbed in order to retain energy essential between meals. The amount of glucose reabsorbed by the kidneys is equivalent to the amount entering the filtration system. With a daily glomerular filtration rate of 180 L, approximately 180 g (180 L/day × 100 mg/dL) of glucose must be reabsorbed each day to maintain an average fasting plasma glucose concentration of 5.6 mmol/L (100 mg/dL). The reabsorption increases with increase in plasma glucose concentration up to approximately 11 mmol/L (198 mg/dL). At this threshold level, the system becomes saturated and the maximal resabsorption rate-the glucose transport maximum (Tm G ) is reached. No more glucose can be absorbed, and the kidneys begin excreting it in the urine-the beginning of glycosuria. Reabsorption of glucose occurs mainly in the proximal tubule and is mediated by 2 different transport proteins, Sodium Glucose Cotransporter (SGLT)1 and SGLT2. SGLT1, which are found in the straight section of the proximal tubule (S3), are responsible for approximately 10% of glucose reabsorption. The other 90% of filtered glucose is reabsorbed through by SGLT2, which are located in the convoluted section on the proximal tubule (S1). The SGLT2 are located on the luminal side of the early proximal tubule S1 segment. Absorption of sodium across the cell membrane creates an energy gradient that in turn allows glucose to be absorbed. On the other side of the cell, sodium is reabsorbed through sodium-potassium ATPase pump into the bloodstream. The concentration gradient within the cell, resulting from this exchange drives glucose reabsorption into the bloodstream via the Glucose transporter (GLUT) 2. The role of kidneys in glucose regulation has been well recognized in the recent years, and inhibition of glucose reabsorption by SGLT2 inhibitors has evolved as a promising target for

  5. Glucose-fructose likely improves gastrointestinal comfort and endurance running performance relative to glucose-only.

    PubMed

    Wilson, P B; Ingraham, S J

    2015-12-01

    This study aimed to determine whether glucose-fructose (GF) ingestion, relative to glucose-only, would alter performance, metabolism, gastrointestinal (GI) symptoms, and psychological affect during prolonged running. On two occasions, 20 runners (14 men) completed a 120-min submaximal run followed by a 4-mile time trial (TT). Participants consumed glucose-only (G) or GF (1.2:1 ratio) beverages, which supplied ∼ 1.3 g/min of carbohydrate. Substrate use, blood lactate, psychological affect [Feeling Scale (FS)], and GI distress were measured. Differences between conditions were assessed using magnitude-based inferential statistics. Participants completed the TT 1.9% (-1.9; -4.2, 0.4) faster with GF, representing a likely benefit. FS ratings were possibly higher and GI symptoms were possibly-to-likely lower with GF during the submaximal period and TT. Effect sizes for GI distress and FS ratings were relatively small (Cohen's d = ∼0.2 to 0.4). GF resulted in possibly higher fat oxidation during the submaximal period. No clear differences in lactate were observed. In conclusion, GF ingestion - compared with glucose-only - likely improves TT performance after 2 h of submaximal running, and GI distress and psychological affect are likely mechanisms. These results apply to runners consuming fluid at 500-600 mL/h and carbohydrate at 1.0-1.3 g/min during running at 60-70% VO2peak .

  6. Effect of Helicteres isora root extracts on glucose tolerance in glucose-induced hyperglycemic rats.

    PubMed

    Venkatesh, Sama; Dayanand Reddy, G; Reddy, Y S R; Sathyavathy, D; Madhava Reddy, B

    2004-06-01

    The ethanol, ethyl acetate and butanol extracts of Helicteres isora root showed significant oral hypoglycemic activity on glucose loaded rats at a dose of 250 mg/kg. The butanol extract showed maximum antihyperglycemic activity and effect being comparable to that of glibenclamide.

  7. Glycolysis-induced discordance between glucose metabolic rates measured with radiolabeled fluorodeoxyglucose and glucose

    SciTech Connect

    Ackermann, R.F.; Lear, J.L. )

    1989-12-01

    We have developed an autoradiographic method for estimating the oxidative and glycolytic components of local CMRglc (LCMRglc), using sequentially administered ({sup 18}F)fluorodeoxyglucose (FDG) and ({sup 14}C)-6-glucose (GLC). FDG-6-phosphate accumulation is proportional to the rate of glucose phosphorylation, which occurs before the divergence of glycolytic (GMg) and oxidative (GMo) glucose metabolism and is therefore related to total cerebral glucose metabolism GMt: GMg + GMo = GMt. With oxidative metabolism, the {sup 14}C label of GLC is temporarily retained in Krebs cycle-related substrate pools. We hypothesize that with glycolytic metabolism, however, a significant fraction of the {sup 14}C label is lost from the brain via lactate production and efflux from the brain. Thus, cerebral GLC metabolite concentration may be more closely related to GMo than to GMt. If true, the glycolytic metabolic rate will be related to the difference between FDG- and GLC-derived LCMRglc. Thus far, we have studied normal awake rats, rats with limbic activation induced by kainic acid (KA), and rats visually stimulated with 16-Hz flashes. In KA-treated rats, significant discordance between FDG and GLC accumulation, which we attribute to glycolysis, occurred only in activated limbic structures. In visually stimulated rats, significant discordance occurred only in the optic tectum.

  8. Exercise training, glucose transporters, and glucose transport in rat skeletal muscles

    NASA Technical Reports Server (NTRS)

    Rodnick, K. J.; Henriksen, E. J.; James, D. E.; Holloszy, J. O.

    1992-01-01

    It was previously found that voluntary wheel running induces an increase in the insulin-sensitive glucose transporter, i.e., the GLUT4 isoform, in rat plantaris muscle (K. J. Rodnick, J. O. Holloszy, C. E. Mondon, and D. E. James. Diabetes 39: 1425-1429, 1990). The present study was undertaken to determine whether 1) the increase in muscle GLUT4 protein is associated with an increase in maximally stimulated glucose transport activity, 2) a conversion of type IIb to type IIa or type I muscle fibers plays a role in the increase in GLUT4 protein, and 3) an increase in the GLUT1 isoform is a component of the adaptation of muscle to endurance exercise. Five weeks of voluntary wheel running that resulted in a 33% increase in citrate synthase activity induced a 50% increase in GLUT4 protein in epitrochlearis muscles of female Sprague-Dawley rats. The rate of 2-deoxy-glucose transport maximally stimulated with insulin or insulin plus contractions was increased approximately 40% (P less than 0.05). There was no change in muscle fiber type composition, evaluated by myosin ATPase staining, in the epitrochlearis. There was also no change in GLUT1 protein concentration. We conclude that an increase in GLUT4, but not of GLUT1 protein, is a component of the adaptive response of muscle to endurance exercise and that the increase in GLUT4 protein is associated with an increased capacity for glucose transport.

  9. Proposal for study on IR light and glucose phantom interaction for human glucose quantification applications

    NASA Astrophysics Data System (ADS)

    Romo-Cárdenas, Gerardo S.; Sanchez-Lopez, Juan D.; Nieto-Hipolito, Juan I.; Cosio-León, María.; Luque-Morales, Priscy; Vazquez-Briseno, Mabel

    2016-09-01

    It has been established the importance of a constant glucose monitoring in order to keep a regular control for diabetes patients. Several medical studies accept the necessity of exploring alternatives for the traditional digital glucometer, given the pain and discomfort related to this technique, which can lead to a compromised control of the disease. Several efforts based on the application of IR spectroscopy had been done with favorable, yet not conclusive results. Therefore it's necessary to apply a comprehensive and interdisciplinary study based on the biochemical and optical properties of the glucose in the human body, in order to understand the interaction between this substance, its surroundings and IR light. These study propose a comprehensive approach of the glucose and IR light interaction, considering and combining important biochemical, physiological and optical properties, as well as some machine learning techniques for the data analysis. The results of this work would help to define the right parameters aiming to obtain an optical glucose quantification system and protocol.

  10. Measurement of glucose concentration in interstitial fluid by surface plasmon resonance with D-galactose/D-glucose binding protein

    NASA Astrophysics Data System (ADS)

    Li, D. C.; Zhang, J. X.; Wu, P.; Huang, F. X.; Song, B.; Xu, K. X.

    2009-08-01

    A novel minimally invasive way to measure blood glucose concentration is proposed by combining interstitial fluid transdermal extraction and surface plasma resonance (SPR) detecting. 55K Hz low-frequency ultrasound pulse is applied for less than 30 seconds to enhance the skin permeability and then interstitial fluid is extracted out of skin by vacuum. The mathematical model to express the correlation between interstitial fluid glucose and blood glucose is also developed by considering the changes of the skin conductivity. The glucose concentration in the interstitial fluid is determined using an optical SPR biological sensor that measures the refractive index. A protein-glucose binding technology using Dgalactose/ D-glucose Binding Protein for specific absorption of glucose is employed to increase SPR measurement precision. By immobilizing GGBP onto the surface of the SPR sensor, the experimental result indicates the detecting resolution of glucose rises to 1mg/L, the system succeeds in distinguishing glucose from other components in mixture. The feasibility of this method is validated for clinical application with the requirements of bloodless, painless, continuous glucose monitoring and a prototype microfluidic diabetes-monitoring device is under development.

  11. Glucose biosensor prepared by glucose oxidase encapsulated sol-gel and carbon-nanotube-modified basal plane pyrolytic graphite electrode.

    PubMed

    Salimi, Abdollah; Compton, Richard G; Hallaj, Rahman

    2004-10-01

    A new glucose biosensor has been fabricated by immobilizing glucose oxidase into a sol-gel composite at the surface of a basal plane pyrolytic graphite (bppg) electrode modified with multiwall carbon nanotube. First, the bppg electrode is subjected to abrasive immobilization of carbon nanotubes by gently rubbing the electrode surface on a filter paper supporting the carbon nanotubes. Second, the electrode surface is covered with a thin film of a sol-gel composite containing encapsulated glucose oxidase. The carbon nanotubes offer excellent electrocatalytic activity toward reduction and oxidation of hydrogen peroxide liberated in the enzymatic reaction between glucose oxidase and glucose, enabling sensitive determination of glucose. The amperometric detection of glucose is carried out at 0.3 V (vs saturated calomel electrode) in 0.05 M phosphate buffer solution (pH 7.4) with linear response range of 0.2-20 mM glucose, sensitivity of 196 nA/mM, and detection limit of 50 microM (S/N=3). The response time of the electrode is < 5s when it is stored dried at 4 degrees C, the sensor showed almost no change in the analytical performance after operation for 3 weeks. The present carbon nanotube sol-gel biocomposite glucose oxidase sensor showed excellent properties for the sensitive determination of glucose with good reproducibility, remarkable stability, and rapid response and in comparison to bulk modified composite biosensors the amounts of enzyme and carbon nanotube needed for electrode fabrication are dramatically decreased.

  12. Construction of near-infrared photonic crystal glucose-sensing materials for ratiometric sensing of glucose in tears.

    PubMed

    Hu, Yumei; Jiang, Xiaomei; Zhang, Laiying; Fan, Jiao; Wu, Weitai

    2013-10-15

    Noninvasive monitoring of glucose in tears is highly desirable in tight glucose control. The polymerized crystalline colloidal array (PCCA) that can be incorporated into contact lens represents one of the most promising materials for noninvasive monitoring of glucose in tears. However, low sensitivity and slow time response of the PCCA reported in previous arts has limited its clinical utility. This paper presents a new PCCA, denoted as NIR-PCCA, comprising a CCA of glucose-responsive sub-micrometered poly(styrene-co-acrylamide-co-3-acrylamidophenylboronic acid) microgels embedded within a slightly positive charged hydrogel matrix of poly(acrylamide-co-2-(dimethylamino)ethyl acrylate). This newly designed NIR-PCCA can reflect near-infrared (NIR) light, whose intensity (at 1722 nm) would decrease evidently with increasing glucose concentration over the physiologically relevant range in tears. The lowest glucose concentration reliably detectable was as low as ca. 6.1 μg/dL. The characteristic response time τ(sensing) was 22.1±0.2s when adding glucose to 7.5 mg/dL, and the higher the glucose concentration is, the faster the time response. Such a rationally designed NIR-PCCA is well suited for ratiometric NIR sensing of tear glucose under physiological conditions, thereby likely to bring this promising glucose-sensing material to the forefront of analytical devices for diabetes.

  13. Chinese herbal medicines for people with impaired glucose tolerance or impaired fasting blood glucose

    PubMed Central

    Grant, Suzanne J; Bensoussan, Alan; Chang, Dennis; Kiat, Hosen; Klupp, Nerida L; Liu, Jian Ping; Li, Xun

    2011-01-01

    Background Around 308 million people worldwide are estimated to have impaired glucose tolerance (IGT); 25% to 75% of these will develop diabetes within a decade of initial diagnosis. At diagnosis, half will have tissue-related damage and all have an increased risk for coronary heart disease. Objectives The objective of this review was to assess the effects and safety of Chinese herbal medicines for the treatment of people with impaired glucose tolerance or impaired fasting glucose (IFG). Search strategy We searched the following databases: The Cochrane Library, PubMed, EMBASE, AMED, a range of Chinese language databases, SIGLE and databases of ongoing trials. Selection criteria Randomised clinical trials comparing Chinese herbal medicines with placebo, no treatment, pharmacological or non-pharmacological interventions in people with IGT or IFG were considered. Data collection and analysis Two authors independently extracted data. Trials were assessed for risk of bias against key criteria: random sequence generation, allocation concealment, blinding of participants, outcome assessors and intervention providers, incomplete outcome data, selective outcome reporting and other sources of bias. Main results This review examined 16 trials lasting four weeks to two years involving 1391 participants receiving 15 different Chinese herbal medicines in eight different comparisons. No trial reported on mortality, morbidity or costs. No serious adverse events like severe hypoglycaemia were observed. Meta-analysis of eight trials showed that those receiving Chinese herbal medicines combined with lifestyle modification were more than twice as likely to have their fasting plasma glucose levels return to normal levels (i.e. fasting plasma glucose <7.8 mmol/L and 2hr blood glucose <11.1 mmol/L) compared to lifestyle modification alone (RR 2.07; 95% confidence intervall (CI) 1.52 to 2.82). Those receiving Chinese herbs were less likely to progress to diabetes over the duration of the

  14. Targeting glucose metabolism for healthy aging

    PubMed Central

    Brewer, Rachel A.; Gibbs, Victoria K.; Smith, Daniel L.

    2016-01-01

    Advancing age is the greatest single risk factor for numerous chronic diseases. Thus, the ability to target the aging process can facilitate improved healthspan and potentially lifespan. Lack of adequate glucoregulatory control remains a recurrent theme accompanying aging and chronic disease, while numerous longevity interventions result in maintenance of glucoregulatory control. In this review, we propose targeting glucose metabolism to enhance regulatory control as a means to ameliorate the aging process. We highlight that calorie restriction improves glucoregulatory control and extends both lifespan and healthspan in model organisms, but we also indicate more practical interventions (i.e., calorie restriction mimetics) are desirable for clinical application in humans. Of the calorie restriction mimetics being investigated, we focus on the type 2 diabetes drug acarbose, an α-glucosidase inhibitor that when taken with a meal, results in reduced enzymatic degradation and absorption of glucose from complex carbohydrates. We discuss alternatives to acarbose that yield similar physiologic effects and describe dietary sources (e.g., sweet potatoes, legumes, and berries) of bioactive compounds with α-glucosidase inhibitory activity. We indicate future research should include exploration of how non-caloric compounds like α-glucosidase inhibitors modify macronutrient metabolism prior to disease onset, which may guide nutritional/lifestyle interventions to support health and reduce age-related disease risk. PMID:28035340

  15. Molecular "wiring" glucose oxidase in supramolecular architecture.

    PubMed

    Deng, Liu; Liu, Ying; Yang, Guocheng; Shang, Li; Wen, Dan; Wang, Fuan; Xu, Zhiai; Dong, Shaojun

    2007-07-01

    Supramolecular organized multilayers were constructed by multiwalled carbon nanotubes modified with ferrocene-derivatized poly(allylamine) redox polymer and glucose oxidase by electrostatic self-assembly. From the analysis of voltammetric signals and fluorescence results, a linear increment of the coverage of enzyme per bilayer was estimated, which demonstrated that the multilayer is constructed in a spatially ordered manner. The cyclic voltammograms obtained from the indium tin oxide (ITO) electrodes coated by the (Fc-PAH@CNT/GOx)n multilayers revealed that bioelectrocatalytic response is directly correlated to the number of deposited bilayers; that is, the sensitivity is tunable by controlling the number of bilayers associated with ITO electrodes. The incorporation of redox-polymer-functionalized carbon nanotubes (CNT) into enzyme films resulted in a 6-10-fold increase in the glucose electrocatalytic current; the bimolecular rate constant of FADH2 oxidation (wiring efficiency) was increased up to 12-fold. Impedance spectroscopy data have yielded the electron diffusion coefficient (De) of this nanostructure to be over 10(-8) cm2 s(-1), which is typically higher than those systems without CNT by at least a factor of 10, indicating that electron transport in the new supramolecular architecture was enhanced by communication of the redox active site of enzyme, redox polymer, and CNT.

  16. Peritoneal Dialysate Glucose Load and Systemic Glucose Metabolism in Non-Diabetics: Results from the GLOBAL Fluid Cohort Study

    PubMed Central

    Chess, James; Do, Jun-Young; Noh, Hyunjin; Lee, Hi-Bahl; Kim, Yong-Lim; Summers, Angela; Williams, Paul Ford; Davison, Sara; Dorval, Marc

    2016-01-01

    Background and Objectives Glucose control is a significant predictor of mortality in diabetic peritoneal dialysis (PD) patients. During PD, the local toxic effects of intra-peritoneal glucose are well recognized, but despite large amounts of glucose being absorbed, the systemic effects of this in non-diabetic patients are not clear. We sought to clarify whether dialysate glucose has an effect upon systemic glucose metabolism. Methods and Materials We analysed the Global Fluid Study cohort, a prospective, observational cohort study initiated in 2002. A subset of 10 centres from 3 countries with high data quality were selected (368 incident and 272 prevalent non-diabetic patients), with multilevel, multivariable analysis of the reciprocal of random glucose levels, and a stratified-by-centre Cox survival analysis. Results The median follow up was 5.6 and 6.4 years respectively in incident and prevalent patients. On multivariate analysis, serum glucose increased with age (β = -0.007, 95%CI -0.010, -0.004) and decreased with higher serum sodium (β = 0.002, 95%CI 0.0005, 0.003) in incident patients and increased with dialysate glucose (β = -0.0002, 95%CI -0.0004, -0.00006) in prevalent patients. Levels suggested undiagnosed diabetes in 5.4% of prevalent patients. Glucose levels predicted death in unadjusted analyses of both incident and prevalent groups but in an adjusted survival analysis they did not (for random glucose 6–10 compared with <6, Incident group HR 0.92, 95%CI 0.58, 1.46, Prevalent group HR 1.42, 95%CI 0.86, 2.34). Conclusions In prevalent non-diabetic patients, random glucose levels at a diabetic level are under-recognised and increase with dialysate glucose load. Random glucose levels predict mortality in unadjusted analyses, but this association has not been proven in adjusted analyses. PMID:27249020

  17. Persistent impaired glucose metabolism in a zebrafish hyperglycemia model.

    PubMed

    Capiotti, Katiucia Marques; Antonioli, Régis; Kist, Luiza Wilges; Bogo, Maurício Reis; Bonan, Carla Denise; Da Silva, Rosane Souza

    2014-05-01

    Diabetes mellitus (DM) affects over 10% of the world's population. Hyperglycemia is the main feature for the diagnosis of this disease. The zebrafish (Danio rerio) is an established model organism for the study of various metabolic diseases. In this paper, hyperglycemic zebrafish, when immersed in a 111 mM glucose solution for 14 days, developed increased glycation of proteins from the eyes, decreased mRNA levels of insulin receptors in the muscle, and a reversion of high blood glucose level after treatment with anti-diabetic drugs (glimepiride and metformin) even after 7 days of glucose withdrawal. Additionally, hyperglycemic zebrafish developed an impaired response to exogenous insulin, which was recovered after 7 days of glucose withdrawal. These data suggest that the exposure of adult zebrafish to high glucose concentration is able to induce persistent metabolic changes probably underlined by a hyperinsulinemic state and impaired peripheral glucose metabolism.

  18. Glucose sensor with a Sagnac interference optical system.

    PubMed

    Kumagai, Tatsuya; Tottori, Yusaku; Miyata, Ryusuke; Kajioka, Hiroshi

    2014-02-01

    The angle of optical rotation was measured by detecting the phase difference between clockwise and counterclockwise circular polarized light that propagated in a sensing loop. This polarimeter, or glucose sensor, consisted of a Sagnac interference optical system with a polarization-maintaining optical fiber, so it was not affected by the control limitations of the polarization rotation angle or the optical power fluctuation that occurs with scattered light, reflection, or polarization rotation in an optical system. The angle of rotation was measured from the phase difference of the glucose sensor when the concentration of glucose was changed. We confirmed that the resolution of optical rotation was 5×10(-4)  deg, and the resolution of the glucose concentration was 1  mg/dl accordingly. The measured specific rotation of glucose was mostly equal to a physical property value. One applications of this glucose sensor is in measuring the blood sugar levels of diabetic patients.

  19. Glucose Augments Killing Efficiency of Daptomycin Challenged Staphylococcus aureus Persisters.

    PubMed

    Prax, Marcel; Mechler, Lukas; Weidenmaier, Christopher; Bertram, Ralph

    2016-01-01

    Treatment of Staphylococcus aureus in stationary growth phase with high doses of the antibiotic dapt