The effect of short-term treatment with lithium carbonate on the outcome of radioiodine therapy in patients with long-lasting Graves' hyperthyroidism.

PubMed

Sekulić, Vladan; Rajić, Milena; Vlajković, Marina; Ilić, Slobodan; Stević, Miloš; Kojić, Marko

2017-12-01

The outcome of radioiodine therapy (RIT) in Graves' hyperthyroidism (GH) mainly depends on radioiodine ( 131 I) uptake and the effective half-life of 131 I in the gland. Studies have shown that lithium carbonate (LiCO 3 ) enhances the 131 I half-life and increases the applied thyroid radiation dose without affecting the thyroid 131 I uptake. We investigated the effect of short-term treatment with LiCO 3 on the outcome of RIT in patients with long-lasting GH, its influence on the thyroid hormones levels 7 days after RIT, and possible side effects. Study prospectively included 30 patients treated with LiCO 3 and 131 I (RI-Li group) and 30 patients only with 131 I (RI group). Treatment with LiCO 3 (900 mg/day) started 1 day before RIT and continued 6 days after. Anti-thyroid drugs withdrawal was 7 days before RIT. Patients were followed up for 12 months. We defined a success of RIT as euthyroidism or hypothyroidism, and a failure as persistent hyperthyroidism. In RI-Li group, a serum level of Li was 0.571 ± 0.156 mmol/l before RIT. Serum levels of TT 4 and FT 4 increased while TSH decreased only in RI group 7 days after RIT. No toxic effects were noticed during LiCO 3 treatment. After 12 months, a success of RIT was 73.3% in RI and 90.0% in RI-Li group (P < 0.01). Hypothyroidism was achieved faster in RI-Li (1st month) than in RI group (3rd month). Euthyroidism slowly decreased in RI-Li group, and not all patients became hypothyroid for 12 months. In contrast, euthyroidism rapidly declined in RI group, and all cured patients became hypothyroid after 6 months. The short-term treatment with LiCO 3 as an adjunct to 131 I improves efficacy of RIT in patients with long-lasting GH. A success of RIT achieves faster in lithium-treated than in RI group. Treatment with LiCO 3 for 7 days prevents transient worsening of hyperthyroidism after RIT. Short-term use of LiCO 3 shows no toxic side effects.

Role of pyruvate dehydrogenase inhibition in the development of hypertrophy in the hyperthyroid rat heart: a combined magnetic resonance imaging and hyperpolarized magnetic resonance spectroscopy study.

PubMed

Atherton, Helen J; Dodd, Michael S; Heather, Lisa C; Schroeder, Marie A; Griffin, Julian L; Radda, George K; Clarke, Kieran; Tyler, Damian J

2011-06-07

Hyperthyroidism increases heart rate, contractility, cardiac output, and metabolic rate. It is also accompanied by alterations in the regulation of cardiac substrate use. Specifically, hyperthyroidism increases the ex vivo activity of pyruvate dehydrogenase kinase, thereby inhibiting glucose oxidation via pyruvate dehydrogenase. Cardiac hypertrophy is another effect of hyperthyroidism, with an increase in the abundance of mitochondria. Although the hypertrophy is initially beneficial, it can eventually lead to heart failure. The aim of this study was to use hyperpolarized magnetic resonance spectroscopy to investigate the rate and regulation of in vivo pyruvate dehydrogenase flux in the hyperthyroid heart and to establish whether modulation of flux through pyruvate dehydrogenase would alter cardiac hypertrophy. Hyperthyroidism was induced in 18 male Wistar rats with 7 daily intraperitoneal injections of freshly prepared triiodothyronine (0.2 mg x kg(-1) x d(-1)). In vivo pyruvate dehydrogenase flux, assessed with hyperpolarized magnetic resonance spectroscopy, was reduced by 59% in hyperthyroid animals (0.0022 ± 0.0002 versus 0.0055 ± 0.0005 second(-1); P=0.0003), and this reduction was completely reversed by both short- and long-term delivery of dichloroacetic acid, a pyruvate dehydrogenase kinase inhibitor. Hyperpolarized [2-(13)C]pyruvate was also used to evaluate Krebs cycle metabolism and demonstrated a unique marker of anaplerosis, the level of which was significantly increased in the hyperthyroid heart. Cine magnetic resonance imaging showed that long-term dichloroacetic acid treatment significantly reduced the hypertrophy observed in hyperthyroid animals (100 ± 20 versus 200 ± 30 mg; P=0.04) despite no change in the increase observed in cardiac output. This work has demonstrated that inhibition of glucose oxidation in the hyperthyroid heart in vivo is mediated by pyruvate dehydrogenase kinase. Relieving this inhibition can increase the metabolic flexibility of the hyperthyroid heart and reduce the level of hypertrophy that develops while maintaining the increased cardiac output required to meet the higher systemic metabolic demand.

Amiodarone induced pneumonitis and hyperthyroidism: case report.

PubMed

Grabczak, Elzbieta Magdalena; Zielonka, Tadeusz M; Wiwała, Joanna; Bareła, Anna Dagmara; Opuchlik, Andrzej; Potulska, Anna; Ambroziak, Urszula; Chazan, Ryszarda

2008-09-01

Amiodarone is a highly effective antiarrhythmic agent used in life-threatening ventricular and supraventricular arrhythmias. Its long-term use may however lead to several adverse effects, including corneal deposits, liver and thyroid gland dysfunction, lung lesions, bone marrow injury, skin lesions, or neurological abnormalities. The article presents the case of a 56-year-old man with a history of a stroke, who after a few days of amiodarone therapy for an episode of atrial fibrillation was diagnosed with amiodarone-induced hyperthyroidism and interstitial pulmonary lesions. Clinical and laboratory symptoms of hyperthyroidism and radiographic signs of pulmonary involvement did not occur until several weeks after discontinuation of amiodarone therapy. Differential diagnosis of causes of hyperthyroidism and diseases causing nodular pulmonary lesions did not demonstrate any other pathologies. Empirical antibiotic therapy and administration of thiamazole and high doses of propranolol failed to improve the patient's clinical status. It was not until thiamazole was given in combination with glucocorticosteroids, when a slow relief of hyperthyroidism symptoms and resolution of radiographic pulmonary signs were observed. Based on the presented case, the risk of appearance of 2 serious concomitant adverse effects was demonstrated, even following a short-term amiodarone therapy. This paper also contains an overview of adverse effects which may be encountered during or after therapy with this effective antiarrhythmic agent. It was emphasized how important it is to select patients appropriately, and to monitor potential adverse effects during amiodarone therapy.

Mechanisms of impaired exercise capacity in short duration experimental hyperthyroidism.

PubMed Central

Martin, W H; Spina, R J; Korte, E; Yarasheski, K E; Angelopoulos, T J; Nemeth, P M; Saffitz, J E

1991-01-01

To investigate the mechanism of reduced exercise tolerance in hyperthyroidism, we characterized cardiovascular function and determinants of skeletal muscle metabolism in 18 healthy subjects aged 26 +/- 1 yr (mean +/- SE) before and after 2 wk of daily ingestion of 100 micrograms of triiodothyronine (T3). Resting oxygen uptake, heart rate, and cardiac output increased and heart rate and cardiac output at the same submaximal exercise intensity were higher in the hyperthyroid state (P less than 0.05). However, maximal oxygen uptake decreased after T3 administration (3.08 +/- 0.17 vs. 2.94 +/- 0.19 l/min; P less than 0.001) despite increased heart rate and cardiac output at maximal exercise (P less than 0.05). Plasma lactic acid concentration at an equivalent submaximal exercise intensity was elevated 25% (P less than 0.01) and the arteriovenous oxygen difference at maximal effort was reduced (P less than 0.05) in the hyperthyroid state. These effects were associated with a 21-37% decline in activities of oxidative (P less than 0.001) and glycolytic (P less than 0.05) enzymes in skeletal muscle and a 15% decrease in type IIA muscle fiber cross-sectional area (P less than 0.05). Lean body mass was reduced (P less than 0.001) and the rates of whole body leucine oxidation and protein breakdown were enhanced (P less than 0.05). Thus, exercise tolerance is impaired in short duration hyperthyroidism because of decreased skeletal muscle mass and oxidative capacity related to accelerated protein catabolism but cardiac pump function is not reduced. PMID:1752962

Effects of methimazole treatment on growth hormone (GH) response to GH-releasing hormone in patients with hyperthyroidism.

PubMed

Giustina, A; Ferrari, C; Bodini, C; Buffoli, M G; Legati, F; Schettino, M; Zuccato, F; Wehrenberg, W B

1990-12-01

In vitro studies have demonstrated that thyroid hormones can enhance basal and stimulated growth hormone secretion by cultured pituitary cells. However, both in man and in the rat the effects of high thyroid hormone levels on GH secretion are unclear. The aim of our study was to test the GH response to human GHRH in hyperthyroid patients and to evaluate the effects on GH secretion of short- and long-term pharmacological decrease of circulating thyroid hormones. We examined 10 hyperthyroid patients with recent diagnosis of Graves' disease. Twelve healthy volunteers served as controls. All subjects received a bolus iv injection of GHRH(1-29)NH2, 100 micrograms. Hyperthyroid patients underwent a GHRH test one and three months after starting antithyroid therapy with methimazole, 10 mg/day po. GH levels at 15, 30, 45, 60 min and GH peak after stimulus were significantly lower in hyperthyroid patients than in normal subjects. The GH peak was also delayed in hyperthyroid patients. After one month of methimazole therapy, most of the hyperthyroid patients had thyroid hormone levels in the normal range, but they did not show significant changes in GH levels after GHRH, and the GH peak was again delayed. After three months of therapy with methimazole, the hyperthyroid patients did not show a further significant decrease in serum thyroid hormone levels. However, mean GH levels from 15 to 60 min were significantly increased compared with the control study. The GH peak after GHRH was also earlier than in the pre-treatment study.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of experimental hyperthyroidism on protein turnover in skeletal and cardiac muscle.

PubMed

Carter, W J; Van Der Weijden Benjamin, W S; Faas, F H

1980-10-01

Since experimental hyperthyroidism reduces skeletal muscle mass while simultaneously increasing cardiac muscle mass, the effect of hyperthyroidism on muscle protein degradation was compared in skeletal and cardiac muscle. Pulse-labeling studies using (3H) leucine and (14C) carboxyl labeled aspartate and glutamate were carried out. Hyperthyroidism caused a 25%-29% increase in protein breakdown in both sarcoplasmic and myofibrillar fractions of skeletal muscle. Increased muscle protein degradation may be a major factor in the development of skeletal muscle wasting and weakness in hyperthyroidism. In contrast, protein breakdown appeared to be reduced 22% in the sarcoplasmic fraction of hyperthyroid heart muscle and was unchanged in the myofibrillar fraction. Possible reasons for the contrasting effects of hyperthyroidism on skeletal and cardiac muscle include increased sensitivity of the hyperthyroid heart to catecholamines, increased cardiac work caused by the hemodynamic effects of hyperthyroidism, and a different direct effect of thyroid hormone at the nuclear level in cardiac as opposed to skeletal muscle.

Short-term preoperative octreotide treatment for TSH-secreting pituitary adenoma.

PubMed

Fukuhara, Noriaki; Horiguchi, Kentaro; Nishioka, Hiroshi; Suzuki, Hisanori; Takeshita, Akira; Takeuchi, Yasuhiro; Inoshita, Naoko; Yamada, Shozo

2015-01-01

Preoperative control of hyperthyroidism in patients with TSH-secreting pituitary adenomas (TSHoma) may avoid perioperative thyroid storm. Perioperative administration of octreotide may control hyperthyroidism, as well as shrink tumor size. The effects of preoperative octreotide treatment were assessed in a large number of patients with TSHomas. Of 81 patients who underwent surgery for TSHoma at Toranomon Hospital between January 2001 and May 2013, 44 received preoperative short-term octreotide. After excluding one patient because of side effects, 19 received octreotide as a subcutaneous injection, and 24 as a long-acting release (LAR) injection. Median duration between initiation of octreotide treatment and surgery was 33.5 days. Octreotide normalized free T4 in 36 of 43 patients (84%) and shrank tumors in 23 of 38 (61%). Length of octreotide treatment did not differ significantly in patients with and without hormonal normalization (p=0.09) and with and without tumor shrinkage (p=0.84). Serum TSH and free T4 concentrations, duration of treatment, incidence of growth hormone (GH) co-secretion, results of octreotide loading tests, form of administration (subcutaneous injection or LAR), tumor volume, and tumor consistency did not differ significantly in patients with and without hormonal normalization and with and without tumor shrinkage. Short-term preoperative octreotide administration was highly effective for TSHoma shrinkage and normalization of excess hormone concentrations, with tolerable side effects.

Role of Cholestyramine in Refractory Hyperthyroidism: A Case Report and Literature Review

PubMed Central

Alswat, Khaled A.

2015-01-01

Patient: Female, 52 Final Diagnosis: Refractory iodine induced hyperthyroidism Symptoms: Neck swelling • shortness of breath Medication: Cholestyramine Clinical Procedure: Total thyroidectomy Specialty: Endocrinology and Metabolic Objective: Unusual clinical course Background: Hyperthyroidism is a common disease that usually responds to the conventional therapy of anti-thyroidal medications (methimazole or PTU) and beta-blocker. Refractory hyperthyroidism is a rare condition in which hyperthyroidism fails to respond to the above therapy. Cholestyramine has been shown to decrease thyroid hormone level when added to the ongoing anti-thyroidal medications. Case Report: A 52-year-old woman with past medical history of enlarging goiter presented with obstructive symptoms of worsening shortness of breath and snoring. Admission thyroid function test showed mild hyperthyroidism (suppressed TSH, slightly high FT4, and high normal FT3) that worsened after she received a CT scan with contrast and failed to respond to a 3-week course of high-dose dexamethasone, high-dose carbimazole, and up-titrated propranolol. Five days after cholestyramine was added, her FT4 decreased by 30% and normalized after 12 days. The patient underwent total thyroidectomy as definitive treatment for the hyperthyroidism and for the obstructive symptoms. Conclusions: Cholestyramine is an effective additional treatment for hyperthyroidism and may be an effective treatment for refractory iodine-induced hyperthyroidism. The possibility of self-remission (natural course) is less likely given the dramatic and rapid response to cholestyramine. PMID:26207323

Mild Thyrotoxicosis Leads to Brain Perfusion Changes: An Arterial Spin Labelling Study.

PubMed

Göbel, A; Heldmann, M; Sartorius, A; Göttlich, M; Dirk, A-L; Brabant, G; Münte, T F

2017-01-01

Hypo- and hyperthyroidism have effects on brain structure and function, as well as cognitive processes, including memory. However, little is known about the influence of thyroid hormones on brain perfusion and the relationship of such perfusion changes with cognition. The present study aimed to demonstrate the effect of short-term experimental hyperthyroidism on brain perfusion in healthy volunteers and to assess whether perfusion changes, if present, are related to cognitive performance. It is known that an interaction exists between brain perfusion and cerebral oxygen consumption rate and it is considered that neural activation increases cerebral regional perfusion rate in brain areas associated with memory. Measuring cerebral blood flow may therefore represent a proxy for neural activity. Therefore, arterial spin labelling (ASL) measurements were conducted and later analysed to evaluate brain perfusion in 29 healthy men before and after ingesting thyroid hormones for 8 weeks. Psychological tests concerning memory were performed at the same time-points and the results were correlated with the imaging results. In the hyperthyroid condition, perfusion was increased in the posterior cerebellum in regions connected with cerebral networks associated with cognitive control and the visual cortex compared to the euthyroid condition. In addition, these perfusion changes were positively correlated with changes of performance in the German version of the Auditory Verbal Learning Task [AVLT, Verbaler Lern-und-Merkfähigkeits-Test (VLMT)]. Cerebellar perfusion and function therefore appears to be modulated by thyroid hormones, likely because the cerebellum hosts a high number of thyroid hormone receptors. © 2016 British Society for Neuroendocrinology.

[Perioperative and postoperative management of two patients with uncontrolled hyperthyroidism using short acting beta blocker, landiolol].

PubMed

Fujita, Yasuki; Shimizu, Tomoaki; Matsumoto, Atsuhiro; Aoki, Motoaki

2008-09-01

Thyroid storm, sudden onset of life-threatening manifestations of hyperthyroidism, often appears during and after surgery in patients with uncontrolled hyperthyroidism. We report perioperative and postoperative management of two such cases with uncontrolled hyperthyroidism. The first patient is a 41-year-old man with a past history of uncontrolled Graves disease, and was scheduled for emergency video-assisted thoracoscopic surgery for spontaneous pneumothorax. The second patient is a 25-year-old man with a past history of hypertension, and was scheduled for open reduction and internal fixation for mandibular fracture. In both patients, tachycardia and hypertension were observed at admission to the operating room. Therapy included the use of landiolol infusion, a short acting beta blocker, for control of tachycardia. Heart rate was controlled around 90 beats x min(-1) using landiolol during surgery. In each case, landiolol was administered until they can take long acting beta blocker and antithyroid drug orally. In the postoperative period, delirium appeared for a few hours in the first case, but no severe complications were observed in each case. Short acting beta blocker was useful for control of tachycardia in the perioperative and postoperative management of the patient with uncontrolled hyperthyroidism.

Older subjects with hyperthyroidism present with a paucity of symptoms and signs: a large cross-sectional study.

PubMed

Boelaert, K; Torlinska, B; Holder, R L; Franklyn, J A

2010-06-01

The absence of classical symptoms and signs of hyperthyroidism often results in delayed diagnosis and treatment. The objective of the study was to determine the prevalence of symptoms and signs of hyperthyroidism according to patients' age and gender as well as severity and type of hyperthyroidism. This was a cross-sectional study of 3049 consecutive patients with hyperthyroidism presenting to a single secondary/tertiary care clinic. Calculation of adjusted odds ratios for presence/absence of symptoms/signs of hyperthyroidism simultaneously analyzing the influence of patients' age/gender, disease etiology/severity, symptom duration, and smoking. The majority of patients older than 61 yr had two or more symptoms. The lowest proportion of subjects reporting five or more symptoms was found in those older than 61 yr. Increasing age was associated with reduced adjusted odds ratio for the presence of most classical symptoms except for weight loss and shortness of breath, independent of disease severity. Those with more severe hyperthyroidism and smokers had increased odds ratios for most symptoms. Older age, higher serum free T(4) concentrations at diagnosis, male gender, and toxic nodular hyperthyroidism were independently associated with risk of atrial fibrillation. Signs of ophthalmopathy were associated with increasing age, smoking, longer symptom duration, and female gender. Classical symptoms and signs of hyperthyroidism are significantly less prevalent in older patients and more prevalent in smokers and subjects with higher free T(4) concentrations. We propose a lower threshold for performing thyroid function tests in patients older than 60 yr, especially in those presenting with atrial fibrillation, weight loss, or shortness of breath.

The Effect of Experimental Hyperthyroidism on Characteristics of Actin-Myosin Interaction in Fast and Slow Skeletal Muscles.

PubMed

Kopylova, G V; Shchepkin, D V; Bershitsky, S Y

2018-05-01

The molecular mechanism of the failure of contractile function of skeletal muscles caused by oxidative damage to myosin in hyperthyroidism is not fully understood. Using an in vitro motility assay, we studied the effect of myosin damage caused by oxidative stress in experimental hyperthyroidism on the actin-myosin interaction and its regulation by calcium. We found that hyperthyroidism-induced oxidation of myosin is accompanied by a decrease in the sliding velocity of the regulated thin filaments in the in vitro motility assay, and this effect is increased with the duration of the pathological process.

Autonomic nervous system function in chronic exogenous subclinical thyrotoxicosis and the effect of restoring euthyroidism.

PubMed

Eustatia-Rutten, Carmen F A; Corssmit, Eleonora P M; Heemstra, Karen A; Smit, Johannes W A; Schoemaker, Rik C; Romijn, Johannes A; Burggraaf, Jacobus

2008-07-01

Knowledge on the relationship between the autonomic nervous system and subclinical hyperthyroidism is mainly based upon cross-sectional studies in heterogeneous patient populations, and the effect of restoration to euthyroidism in subclinical hyperthyroidism has not been studied. We investigated the long-term effects of exogenous subclinical hyperthyroidism on the autonomic nervous system and the potential effects of restoration of euthyroidism. This was a prospective single-blinded, placebo-controlled, randomized trial. The study was performed at a university hospital. A total of 25 patients who were on more than 10-yr TSH suppressive therapy after thyroidectomy was examined. Patients were studied at baseline and subsequently randomized to a 6-month thyroid hormone substitution regimen to obtain either euthyroidism or maintenance of the subclinical hyperthyroid state. Urinary excretion of catecholamines and heart rate variability were measured. Baseline data of the subclinical hyperthyroidism patients were compared with data obtained in patients with hyperthyroidism and controls. Urinary excretion of norepinephrine and vanillylmandelic acid was higher in the subclinical hyperthyroidism patients compared with controls and lower compared with patients with overt hyperthyroidism. Heart rate variability was lower in patients with hyperthyroidism, intermediate in subclinical hyperthyroidism patients, and highest in the healthy controls. No differences were observed after restoration of euthyroidism. Long-term exogenous subclinical hyperthyroidism has effects on the autonomic nervous system measured by heart rate variability and urinary catecholamine excretion. No differences were observed after restoration to euthyroidism. This may indicate the occurrence of irreversible changes or adaptation during long-term exposure to excess thyroid hormone that is not remedied by 6-month euthyroidism.

Cardiac microvascular rarefaction in hyperthyroidism-induced left ventricle dysfunction.

PubMed

Freitas, Felipe; Estato, Vanessa; Carvalho, Vinícius Frias; Torres, Rafael Carvalho; Lessa, Marcos Adriano; Tibiriçá, Eduardo

2013-10-01

The pathophysiology underlying hyperthyroidism-induced left ventricle (LV) dysfunction and hypertrophy directly involves the heart and indirectly involves the neuroendocrine systems. The effects of hyperthyroidism on the microcirculation are still controversial in experimental models. We investigated the effects of hyperthyroidism on the cardiac function and microcirculation of an experimental rat model. Male Wistar rats (170-250 g) were divided into two groups: the euthyroid group (n = 10), which was treated with 0.9% saline solution, and the hyperthyroid group (n = 10), which was treated with l-thyroxine (600 μg/kg/day, i.p.) during 14 days. An echocardiographic study was performed to evaluate the alterations in cardiac function, structure and geometry. The structural capillary density and the expression of angiotensin II AT1 receptor in the LV were analyzed using histochemistry and immunohistochemistry, respectively. Hyperthyroidism was found to induce profound cardiovascular alterations, such as systolic hypertension, tachycardia, LV dysfunction, cardiac hypertrophy, and myocardial fibrosis. This study demonstrates the existence of structural capillary rarefaction and the down-regulation of the cardiac angiotensin II AT1 receptor in the myocardium of hyperthyroid rats in comparison with euthyroid rats. Microvascular rarefaction may be involved in the pathophysiology of hyperthyroidism-induced cardiovascular alterations. © 2013 John Wiley & Sons Ltd.

Effects of melatonin on lipid peroxidation and anti-oxidant enzyme activity in rats with experimentally induced hyperthyroidism.

PubMed

Baydas, Burhanettin; Meral, Ismail

2005-07-01

1. The present study was designed to investigate the effects of high-dose melatonin on lipid peroxidation and anti-oxidant enzyme activity in rats with experimentally induced hyperthyroidism. 2. Twenty-four albino male rats, weighing 240-260 g, were randomly allotted into one of three experimental groups (control, hyperthyroid and hyperthyroid + melatonin treatment), with each group containing eight animals. Hyperthyroidism was induced by a daily with i.p. injection of 200 microg l-thyroxine for 30 days. In addition to l-thyroxin treatment, rats in the hyperthyroid + melatonin treatment group were also given daily i.p. injections of 10 mg/kg melatonin on the last 10 days of l-thyroxine treatment. Control animals received injections of an equivalent volume of saline solution. Rats received the last injection 24 h before being killed. 3. At the end of the experiment, rats in all three groups were fasted for 12 h and killed by cardiac puncture under ether anaesthesia. Blood samples were taken for the determination of malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) levels and concentrations of tri-iodothyronine (T(3)) and thyroxine (T(4)). 4. It was found that MDA and SOD levels and concentrations of T(3) and T(4) were higher and the GSH level was lower in rats with hyperthyroidism compared with controls. Melatonin treatment decreased the elevated MDA and SOD levels and increased the lowered GSH level to control levels in rats with hyperthyroidism, but did not ameliorate the concentrations of T(3) and T(4). 5. It was concluded that high-dose melatonin treatment may decrease the hyperthyroidism-induced disturbances of lipid peroxidation and anti-oxidant enzyme activity and oxidative damage.

Management of hyperthyroidism during pregnancy and lactation.

PubMed

Azizi, Fereidoun; Amouzegar, Atieh

2011-06-01

Poorly treated or untreated maternal overt hyperthyroidism may affect pregnancy outcome. Fetal and neonatal hypo- or hyper-thyroidism and neonatal central hypothyroidism may complicate health issues during intrauterine and neonatal periods. To review articles related to appropriate management of hyperthyroidism during pregnancy and lactation. A literature review was performed using MEDLINE with the terms 'hyperthyroidism and pregnancy', 'antithyroid drugs and pregnancy', 'radioiodine and pregnancy', 'hyperthyroidism and lactation', and 'antithyroid drugs and lactation', both separately and in conjunction with the terms 'fetus' and 'maternal.' Antithyroid drugs are the main therapy for maternal hyperthyroidism. Both methimazole (MMI) and propylthiouracil (PTU) may be used during pregnancy; however, PTU is preferred in the first trimester and should be replaced by MMI after this trimester. Choanal and esophageal atresia of fetus in MMI-treated and maternal hepatotoxicity in PTU-treated pregnancies are of utmost concern. Maintaining free thyroxine concentration in the upper one-third of each trimester-specific reference interval denotes success of therapy. MMI is the mainstay of the treatment of post partum hyperthyroidism, in particular during lactation. Management of hyperthyroidism during pregnancy and lactation requires special considerations and should be carefully implemented to avoid any adverse effects on the mother, fetus, and neonate.

Efficacy of Low-dose (2 millicurie) versus Standard-dose (4 millicurie) Radioiodine Treatment for Cats with Mild-to-Moderate Hyperthyroidism.

PubMed

Lucy, J M; Peterson, M E; Randolph, J F; Scrivani, P V; Rishniw, M; Davignon, D L; Thompson, M S; Scarlett, J M

2017-03-01

Radioiodine ( 131 I) is effective treatment for hyperthyroidism in cats, but optimal dose to restore euthyroidism without inducing hypothyroidism is unclear. Treatment-induced hypothyroidism can lead to azotemia and reduced duration of survival. To compare efficacy and short-term outcomes of low-dose 131 I versus higher, standard-dose 131 I as treatment for hyperthyroidism. A total of 189 client-owned cats undergoing 131 I treatment for mild-to-moderate hyperthyroidism (serum T 4 ≥ 4.0 μg/dL and <13.0 μg/dL). Prospective, nonrandomized, cohort study comparing treatment with either low-dose (2 mCi, n = 150) or standard-dose (4 mCi, n = 39) 131 I. Serum T 4 , thyroid-stimulating hormone (TSH), and creatinine concentrations were measured after 1, 3, and 6 months to determine persistent hyperthyroidism, overt hypothyroidism (low T 4 , high TSH), subclinical hypothyroidism (normal T 4 , high TSH), and azotemia. There was no significant difference in prevalence of cats with persistent hyperthyroidism between standard- and low-dose treatment groups at 3 (0% versus 5.3%; P = .34) and 6 (0% versus 3.3%; P = .51) months. Overt (18% versus 1%; P = .0005) or subclinical (46% versus 21%; P = .004) hypothyroidism was more common in cats at 6 months after standard-dose 131 I. No difference in incidence of azotemia existed between groups, but cats treated with standard-dose 131 I had higher creatinine concentrations (P < .05) and higher percent rises in creatinine (P < .0001). Low-dose 131 I is safe and effective for cats with mild-to-moderate hyperthyroidism, as evidenced by a cure rate of >95% with reduced frequency of iatrogenic hypothyroidism and azotemia. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Effect of experimental hyperthyroidism on skeletal-muscle proteolysis.

PubMed

Carter, W J; van der Weijden Benjamin, W S; Faas, F H

1981-03-15

It is not clear whether the muscle wasting commonly observed in hyperthyroidism is due to alteration in the rate of protein synthesis or degradation. The effect of experimental hyperthyroidism on skeletal-muscle proteolysis in the rat was studied by measuring alanine and tyrosine release from isolated skeletal muscles in vitro and 3-methyl-histidine excretion in vivo. Alanine release from the isolated epitrochlaris-muscle preparation was increased as soon as 24h after a 25 microgram dose of L-tri-iodothyronine in vivo. Conversely, alanine release from muscles of hypothyroid rats was decreased, but restored by L-tri-iodothyronine supplementation before death. Furthermore, 3-methylhistidine excretion was increased in hyperthyroid rats throughout an 18-day treatment period. The increased amino acid release from isolated muscles and the increased 3-methylhistidine excretion in vivo strongly suggests that hyperthyroidism increases skeletal-muscle proteolysis. Furthermore, the thyroid-hormone concentration may be an important factor in regulating muscle proteolysis.

Effect of experimental hyperthyroidism on skeletal-muscle proteolysis.

PubMed Central

Carter, W J; van der Weijden Benjamin, W S; Faas, F H

1981-01-01

It is not clear whether the muscle wasting commonly observed in hyperthyroidism is due to alteration in the rate of protein synthesis or degradation. The effect of experimental hyperthyroidism on skeletal-muscle proteolysis in the rat was studied by measuring alanine and tyrosine release from isolated skeletal muscles in vitro and 3-methyl-histidine excretion in vivo. Alanine release from the isolated epitrochlaris-muscle preparation was increased as soon as 24h after a 25 microgram dose of L-tri-iodothyronine in vivo. Conversely, alanine release from muscles of hypothyroid rats was decreased, but restored by L-tri-iodothyronine supplementation before death. Furthermore, 3-methylhistidine excretion was increased in hyperthyroid rats throughout an 18-day treatment period. The increased amino acid release from isolated muscles and the increased 3-methylhistidine excretion in vivo strongly suggests that hyperthyroidism increases skeletal-muscle proteolysis. Furthermore, the thyroid-hormone concentration may be an important factor in regulating muscle proteolysis. PMID:7306017

[Effect of melaxen and valdoxan on free radical processes intensity, aconitate hydratase activity and citrate content in rats tissues under hyperthyroidism].

PubMed

Gorbenko, M V; Popova, T N; Shul'gin, K K; Popov, S S; Agarkov, A A

2014-01-01

The influence of melaxen and valdoxan on the biochemiluminescence parameters, aconitate hydratase activity and citrate level in rats heart and liver during development of experimental hyperthyroidism has been investigated. Administration of these substances promoted a decrease of biochemiluminescence parameters, which had been increased in tissues of rats in response to the development of oxidative stress under hyperthyroidism. Aconitate hydratase activity and citrate concentration in rats liver and heart, growing at pathological conditions, changed towards control value after administration of the drugs correcting melatonin level. The results indicate the positive effect of valdoxan and melaxen on oxidative status of the organism under the development of experimental hyperthyroidism that is associated with antioxidant action of melatonin.

Oxidative status and citrate concentration in rat tissues during experimental hyperthyroidism and melatonin treatment.

PubMed

Popov, S S; Pashkov, A N; Popova, T N; Zoloedov, V I; Semenikhina, A V; Rakhmanova, T I

2007-08-01

Biochemiluminescence increased, while aconitate hydratase activity and citrate accumulation in tissues of the liver and heart and blood decreased in rats with experimental hyperthyroidism. These changes reflect activation of free radical oxidation, damage to enzyme molecules with reactive oxygen species, and impaired utilization of citrate under pathological conditions. Melatonin treatment during hyperthyroidism normalized aconitate hydratase activity and citrate concentration. Biochemiluminescence study showed that the effect of melatonin is related to antioxidant activity of this hormone, inhibition of free radical oxidation, and suppression of reactive oxygen species generation.

[Congenital hyperthyroidism in maternal Basedow disease].

PubMed

Meden, H; Rath, W

1989-09-01

A case of congenital hyperthyroidism, after pregnancy complicated by Graves' disease is presented. Fetal tachycardia was the cardial symptom. Caesarean section was performed in the 29 years old patient with normal thyroid function in the 29th week of pregnancy. The neonate showed symptoms of a congenital hyperthyroidism with goitre. Antithyroid antibodies were found in the serum of both mother and child. At the age of ten weeks, after a short course of thyrostatic treatment, the infant was discharged with normal thyroid function following complicationfree progress.

Leptin, neuropeptide Y (NPY), melatonin and zinc levels in experimental hypothyroidism and hyperthyroidism: relation with melatonin and the pineal gland.

PubMed

Baltaci, Abdulkerim Kasım; Mogulkoc, Rasim

2018-03-02

Background Melatonin, an important neurohormone released from the pineal gland, is generally accepted to exercise an inhibitor effect on the thyroid gland. Zinc mediates the effects of many hormones and is found in the structure of numerous hormone receptors. Aim The present study aims to examine the effect of melatonin supplementation and pinealectomy on leptin, neuropeptide Y (NPY), melatonin and zinc levels in rats with hypothyroidism and hyperthyroidism. Methods This study was performed on the 70 male rats. Experimental animals in the study were grouped as follows: control (C); hypothyroidism (PTU); hypothyroidism + melatonin (PTU + M); hypothyroidism + pinealectomy (PTU + Pnx); hyperthyroidism (H); hyperthyroidism + melatonin (H + M) and hyperthyroidism + pinealectomy (H + Pnx). Blood samples collected at the end of 4-week procedures were analyzed to determine melatonin, leptin, NPY and zinc levels. Results It was found that thyroid parameters thyroid stimulating hormone (TSH), free triiodthyronine (FT3), free thyroxine (FT4), total T3 (TT3) and total T4 (TT4) decreased in hypothyroidism groups and increased in the groups with hyperthyroidism. The changes in these hormones remained unaffected by melatonin supplementation and pinealectomy. Melatonin levels rose in hyperthyroidism and fell in hypothyroidism. Leptin and NPY levels increased in both hypothyroidism and hyperthyroidism. Zinc levels, on the other hand, decreased in hypothyroidism and pinealectomy, but increased in hyperthyroidism. Conclusion The results of the study demonstrate that hypothyroidism and hyperthyroidism affect leptin, NPY, melatonin and zinc values in different ways in rats. However, melatonin supplementation and pinealectomy do not have any significant influence on the changes occurring in leptin, NPY and zinc levels in thyroid dysfunction.

Role of Cholestyramine in Refractory Hyperthyroidism: A Case Report and Literature Review.

PubMed

Alswat, Khaled A

2015-07-24

Hyperthyroidism is a common disease that usually responds to the conventional therapy of anti-thyroidal medications (methimazole or PTU) and beta-blocker. Refractory hyperthyroidism is a rare condition in which hyperthyroidism fails to respond to the above therapy. Cholestyramine has been shown to decrease thyroid hormone level when added to the ongoing anti-thyroidal medications. A 52-year-old woman with past medical history of enlarging goiter presented with obstructive symptoms of worsening shortness of breath and snoring. Admission thyroid function test showed mild hyperthyroidism (suppressed TSH, slightly high FT4, and high normal FT3) that worsened after she received a CT scan with contrast and failed to respond to a 3-week course of high-dose dexamethasone, high-dose carbimazole, and up-titrated propranolol. Five days after cholestyramine was added, her FT4 decreased by 30% and normalized after 12 days. The patient underwent total thyroidectomy as definitive treatment for the hyperthyroidism and for the obstructive symptoms. Cholestyramine is an effective additional treatment for hyperthyroidism and may be an effective treatment for refractory iodine-induced hyperthyroidism. The possibility of self-remission (natural course) is less likely given the dramatic and rapid response to cholestyramine.

Depression and anxiety in hyperthyroidism.

PubMed

Demet, Mehmet Murat; Ozmen, Bilgin; Deveci, Artuner; Boyvada, Sibel; Adigüzel, Hakan; Aydemir, Omer

2002-01-01

Our objective was to determine symptomatology of depression and anxiety in patients with untreated hyperthyroidism and compare with euthyroid patients. Thirty-two patients with hyperthyroidism (high free T3 and free T4, and suppressed TSH) and 30 euthyroid (normal free T3, free T4, and TSH) controls attending the Endocrinology Out-Patient Department at Celal Bayar University Hospital in Manisa, Turkey were included in the study. Hormonal screening was performed by immunoassay and hemagglutination method. For psychiatric assessment, Hospital Anxiety and Depression Scale [HAD], Hamilton Depression Rating Scale [HAM-D], and Hamilton Anxiety Rating Scale [HAM-A] were used. There was no difference between the two groups in terms of demographic features. Total scores obtained both from HAM-D and HAM-A were significantly greater in the hyperthyroidism group than that of the euthyroid group (p <0.05); there was no difference in terms of HAD. When compared in terms of symptomatology, early insomnia (HAM-D#6), work and activities (HAM-D#7), psychic anxiety (HAM-D#10), weight loss (HAM-D#16), insomnia (HAM-A#4), and cardiovascular symptoms (HAM-A#8) were significantly more frequent in the hyperthyroidism group. By Wilks lambda discriminant analysis, psychomotor agitation (HAM-D#9), weight loss (HAM-D#16), and insomnia (HAM-A#4) were found as the discriminating symptoms for the hyperthyroidism group, whereas somatic anxiety (HAM-A#11) and loss of interest (HAD#14) were distinguishing symptoms of the euthyroidism group. Hyperthyroidism and syndromal depression-anxiety have overlapping features that can cause misdiagnosis during acute phase. For differential diagnosis, one should follow-up patients with hyperthyroidism with specific hormonal treatment and evaluate persisting symptoms thereafter. In addition to specific symptoms of hyperthyroidism, psychomotor retardation, guilt, muscle pain, energy loss, and fatigue seem to appear more frequently in patients with comorbid depression and hyperthyroidism; thus, presence of these symptoms should be a warning sign to nonpsychiatric professionals for the need for psychiatric consultation.

Circulating Hepcidin-25 Is Reduced by Endogenous Estrogen in Humans.

PubMed

Lehtihet, Mikael; Bonde, Ylva; Beckman, Lena; Berinder, Katarina; Hoybye, Charlotte; Rudling, Mats; Sloan, John H; Konrad, Robert J; Angelin, Bo

2016-01-01

Hepcidin reduces iron absorption by binding to the intestinal iron transporter ferroportin, thereby causing its degradation. Although short-term administration of testosterone or growth hormone (GH) has been reported to decrease circulating hepcidin levels, little is known about how hepcidin is influenced in human endocrine conditions associated with anemia. We used a sensitive and specific dual-monoclonal antibody sandwich immunoassay to measure hepcidin-25 in patients (a) during initiation of in vitro fertilization when endogenous estrogens were elevated vs. suppressed, (b) with GH deficiency before and after 12 months substitution treatment, (c) with hyperthyroidism before and after normalization, and (d) with hyperprolactinemia before and after six months of treatment with a dopamine agonist. In response to a marked stimulation of endogenous estrogen production, median hepcidin levels decreased from 4.85 to 1.43 ng/mL (p < 0.01). Hyperthyroidism, hyperprolactinemia, or GH substitution to GH-deficient patients did not influence serum hepcidin-25 levels. In humans, gonadotropin-stimulated endogenous estrogen markedly decreases circulating hepcidin-25 levels. No clear and stable correlation between iron biomarkers and hepcidin-25 was seen before or after treatment of hyperthyroidism, hyperprolactinemia or growth hormone deficiency.

Circulating Hepcidin-25 Is Reduced by Endogenous Estrogen in Humans

PubMed Central

Lehtihet, Mikael; Bonde, Ylva; Beckman, Lena; Berinder, Katarina; Hoybye, Charlotte; Rudling, Mats; Sloan, John H.; Konrad, Robert J.; Angelin, Bo

2016-01-01

Objective Hepcidin reduces iron absorption by binding to the intestinal iron transporter ferroportin, thereby causing its degradation. Although short-term administration of testosterone or growth hormone (GH) has been reported to decrease circulating hepcidin levels, little is known about how hepcidin is influenced in human endocrine conditions associated with anemia. Research design and methods We used a sensitive and specific dual–monoclonal antibody sandwich immunoassay to measure hepcidin-25 in patients (a) during initiation of in vitro fertilization when endogenous estrogens were elevated vs. suppressed, (b) with GH deficiency before and after 12 months substitution treatment, (c) with hyperthyroidism before and after normalization, and (d) with hyperprolactinemia before and after six months of treatment with a dopamine agonist. Results In response to a marked stimulation of endogenous estrogen production, median hepcidin levels decreased from 4.85 to 1.43 ng/mL (p < 0.01). Hyperthyroidism, hyperprolactinemia, or GH substitution to GH-deficient patients did not influence serum hepcidin-25 levels. Conclusions In humans, gonadotropin-stimulated endogenous estrogen markedly decreases circulating hepcidin-25 levels. No clear and stable correlation between iron biomarkers and hepcidin-25 was seen before or after treatment of hyperthyroidism, hyperprolactinemia or growth hormone deficiency. PMID:26866603

P wave duration and dispersion in patients with hyperthyroidism and the short-term effects of antithyroid treatment.

PubMed

Guntekin, Unal; Gunes, Yilmaz; Simsek, Hakki; Tuncer, Mustafa; Arslan, Sevket

2009-09-01

Prolonged P wave duration and P wave dispersion (PWD) have been associated with an increased risk for atrial fibrillation (AF). Hyperthytodism is a frequent cause of atrial fibrillation (AF). Forty-two patients with newly diagnosed overt hyperthyroidism and 20 healthy people were enrolled in the study. Transthoracic echocardiography, 12 lead surface ECG and thyroid hormone levels were studied at the time of enrollment and after achievement of euthyroid state with propylthiouracil treatment. Maximum P wave duration (Pmax) (97.4+/-14.6 vs. 84.2+/-9.5 msec, p<0.001), PWD (42.9+/-10.7 vs. 31.0+/-6.2 msec, p<0.001), deceleration (DT) (190.7+/-22.6 vs. 177.0+/-10.2 msec, p=0.013) and isovolumetric relaxation times (IVRT) (90.9+/-11.2 vs. 79.6+/-10.5 msec, p<0.001) were significantly higher in hyperthyroid patients compared to control group. Pmax and PWD were significantly correlated with the presence of hyperthyroidism. Pmax (97.4+/-14.6 to 84.3+/-8.6 msec, p<0,001) Pmin (54.1+/-8.6 to 48.1+/-8.5 msec, p=0.002), PWD (42.9+/-10.7 to 35.9+/-8.1 msec, p=0.002) and DT (190.7+/-22.6 to 185.5+/-18.3, p=0.036) were significantly decreased after achievement of euthyroid state in patients with hyperthyroidism. Diastolic dyfunction was seen in 5 patients at hyperthroid state but only in one patient at euthyroid state. Hyperthyroidism is associated with prolonged P wave duration and dispersion. Achievement of euthyroid state with propylthiouracil treatment results in shortening of P wave variables. Diastolic function may have a partial effect for the increased Pmax and PWD. Shortening of Pmax and PWD may be a marker for the prevention of AF with the anti-thyroid treatment.

Hyperthyroidism in patients with ischaemic heart disease after iodine load induced by coronary angiography: Long-term follow-up and influence of baseline thyroid functional status.

PubMed

Bonelli, Nadia; Rossetto, Ruth; Castagno, Davide; Anselmino, Matteo; Vignolo, Francesca; Parasiliti Caprino, Mirko; Gaita, Fiorenzo; Ghigo, Ezio; Garberoglio, Roberto; Grimaldi, Roberto; Maccario, Mauro

2018-02-01

To study the effect of a iodine load on thyroid function of patients with ischaemic heart disease (IHD) and the long-term influence of unknown subclinical hyperthyroidism. Subclinical hyperthyroidism is considered an independent risk factors for cardiovascular morbidity of patients with IHD. They routinely undergo coronary angiography with iodine contrast media (ICM) which may induce or even worsen hyperthyroidism. A cross-sectional study followed by a longitudinal study on patients with subclinical hyperthyroidism. 810 consecutive IHD outpatients without known thyroid diseases or treatment with drugs influencing thyroid activity undergoing elective coronary angiography. We evaluated thyroid function either before and 1 month after ICM; patients with thyrotoxicosis at baseline or after ICM were then followed up for 1 year. 58 patients had hyperthyroidism at baseline (HB, 7.2%), independently associated to FT4 levels, thyroid nodules and family history of thyroid diseases. After ICM, the prevalence of hyperthyroidism was 81 (10%). Hyperthyroidism after ICM was positively predicted by baseline fT4 levels, thyroid nodules, age over 60, male gender, family history of thyroid diseases. Three months after ICM, 34 patients (4.2%) still showed hyperthyroidism (22 from HB, 13 treated with methimazole). One year after ICM, hyperthyroidism was still present in 20 patients (2.5%, all from HB, 13 treated). The prevalence of spontaneous subclinical hyperthyroidism in IHD is surprisingly elevated and is further increased by iodine load, particularly in patients with thyroid nodules and familial history of thyroid diseases, persisting in a not negligible number of them even after one year. © 2017 John Wiley & Sons Ltd.

Effects of thyroid status on NEI concentration in specific brain areas related to reproduction during the estrous cycle.

PubMed

Ayala, Carolina; Pennacchio, Gisela Erika; Soaje, Marta; Carreño, Norma Beatriz; Bittencourt, Jakson Cioni; Jahn, Graciela Alma; Celis, María Ester; Valdez, Susana Ruth

2013-11-01

We previously showed that short-term hypo- and hyperthyroidism induce changes in neuropeptide glutamic-acid-isoleucine-amide (NEI) concentrations in discrete brain areas in male rats. To investigate the possible effects of hypo- and hyperthyroidism on NEI concentrations mainly in hypothalamic areas related to reproduction and behavior, female rats were sacrificed at different days of the estrous cycle. Circulating luteinizing hormone (LH), estradiol and progesterone concentrations were measured in control, hypothyroid (hypoT, treated with PTU during 7-9 days) and hyperthyroid (hyperT, l-T4 during 4-7 days) animals. Both treatments blunted the LH surge. Hypo- and hyperthyroidism increased estradiol concentrations during proestrus afternoon (P-PM), although hypoT rats showed lower values compared to control during proestrus morning (P-AM). Progesterone levels were higher in all groups at P-PM and in the hyperT during diestrus morning (D2). NEI concentrations were lower in hypoT rats during the estrous cycle except in estrus (E) in the peduncular part of the lateral hypothalamus (PLH). They were also reduced by both treatments in the perifornical part of the lateral hypothalamus (PeFLH) during P-PM. Hypothyroidism led to higher NEI concentrations during P-PM in the organum vasculosum of the lamina terminalis and anteroventral periventricular nucleus (OVLT+AVPV). The present results indicate that NEI concentration is regulated in a complex manner by hypo- and hyperthyroidism in the different areas studied, suggesting a correlation between NEI values and the variations of gonadal steroid levels during estrous cycle. These changes could be, in part, responsible for the alterations observed in the hypothalamic-pituitary-gonadal axis in these pathologies. Copyright © 2013 Elsevier Inc. All rights reserved.

[THE STATUS OF CERTAIN PHYSIOLOGICAL ADRENERGIC RESPONSES IN ALBINO RATS DURING DEVELOPMENT OF EXPERIMENTAL HYPERTHYROIDISM].

PubMed

Osman, Nizar Salim; Ismail, Mohsen

2015-01-01

In this paper we investigated the effects of thyroid hormones on the expression of physiological reactions during adrenergic stimulation (20 min at a dose of 2.0 mg x kg(-1) x min(-1)) during the development of experimental hyperthyroidism. Rats were divided into two groups. The animals in Group 1 were injected woth triiodothyronine. The duration of injection ranged from 1 to 12 days. Consequently, 12 subgroups were formed. The second group was the control group. It is shown that in the process of development of experimental hyperthyroidism all physiological responses vary in accordance with the law, which can be described by a parabola of general form with the value of the degree in the equation equal to three.

[Subclinical hyperthyroidism: from diagnosis to treatment].

PubMed

Corvilain, B

2012-09-01

Subclinical hyperthyroidism is a common clinical entity. Subclinical hyperthyroidism is defined as a serum TSH below the reference range but a normal T4 and T3 level in an asymptomatic patient. Whether or not subclinical hyperthyroidism should be treated remains a matter of debate. Cross-sectional studies and longitudinal population-based studies demonstrate association between subclinical hyperthyroidism and risk of atrial fibrillation, osteoporosis and cardiovascular and global mortality. However, there are no randomized clinical trials answering the question whether long term-health outcomes are improved by the treatment of subclinical hyperthyroidism. Therefore in the absence of evidence for or against treatment of subclinical hyperthyroidism, it seems appropriate to follow algorithms that consider the level of TSH and the presence of risks factors (age > 65 years, osteoporosis, post menopause and cardiac disease).

Protein degradation in skeletal muscle during experimental hyperthyroidism in rats and the effect of beta-blocking agents.

PubMed

Angerås, U; Hasselgren, P O

1987-04-01

beta-Blocking agents are increasingly used in the management of hyperthyroid patients. The effect of this treatment on increased muscle protein breakdown in the hyperthyroid state is not known. In the present study, experimental hyperthyroidism was induced in rats by daily ip injections of T3 (100 micrograms/100 g BW) during a 10-day period. Control animals received corresponding volumes of solvent. In groups of rats the selective beta-1-blocking agent metoprolol or the nonselective beta-blocker propranolol was infused by miniosmotic pumps implanted sc on the backs of the animals. Protein degradation was measured in incubated intact soleus and extensor digitorum longus muscles by determining tyrosine release into the incubation medium. The protein degradation rate in incubated extensor digitorum longus and soleus muscles was increased by 50-60% during T3 treatment. Metoprolol or propranolol did not influence muscle protein breakdown in either T3-treated or control animals. The results suggest that T3-induced increased muscle proteolysis is not mediated by beta-receptors, and muscle weakness and wasting in hyperthyroidism might not be affected by beta-blockers.

History of hyperthyroidism and long-term outcome of catheter ablation of drug-refractory atrial fibrillation.

PubMed

Wongcharoen, Wanwarang; Lin, Yenn-Jiang; Chang, Shih-Lin; Lo, Li-Wei; Hu, Yu-Feng; Chung, Fa-Po; Chong, Eric; Chao, Tze-Fan; Tuan, Ta-Chuan; Chang, Yao-Ting; Lin, Chin-Yu; Liao, Jo-Nan; Lin, Yi-Chun; Chen, Yun-Yu; Chen, Shih-Ann

2015-09-01

Hyperthyroidism is a known reversible cause of atrial fibrillation (AF). However, some patients remain in AF despite restoration of euthyroid status. The purpose of this study was to compare the electrophysiologic characteristics and long-term ablation outcome in AF patients with and without history of hyperthyroidism. The study enrolled 717 consecutive patients with AF who underwent first AF ablation, which involved pulmonary vein (PV) isolation in paroxysmal AF and additional substrate modification in nonparoxysmal AF patients. Eighty-four patients (12%) with hyperthyroidism history were compared to those without. Euthyroid status was achieved for ≥3 months before ablation in hyperthyroid patients. Patients with hyperthyroid history were associated with older age, more female gender, lower mean right atrial voltage, higher number of PV ectopic foci (1.3 ± 0.4 vs 1.0 ± 0.2, P < .01), and higher prevalence of non-PV foci (42% vs 23%, P < .01). Ectopic foci from ligament of Marshall were demonstrated more often in hyperthyroid patients (7.1% vs 1.6%, P < .01) in whom alcohol ablations were required. After propensity score matching for potential covariates, history of hyperthyroidism was an independent predictor of AF recurrence after single procedure (hazard ratio 2.07, 95% confidence interval 1.27-3.38). AF recurrence rates after multiple procedures were not different between patients with and those without hyperthyroid history. Patients with hyperthyroid history had a significantly higher number of PV ectopies and higher prevalence of non-PV ectopic foci compared to euthyroid patients, which resulted in a higher AF recurrence rate after a single procedure. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Effects of hyperthyroidism induced by L-thyroxin administration on lipid peroxidation in various rat tissues.

PubMed

Mogulkoc, R; Baltaci, A Kasim; Oztekin, Esma; Sivrikaya, A; Aydin, Leyla

2006-06-01

Thyroid dysfunctions are associated with many pathological signs in the body. One of these is lipid peroxidation that develops due to over- or under-secretion of thyroid hormones. The present study was conducted to determine lipid peroxidation that develops in different tissues including the brain, liver and heart of rats in experimental hyperthyroidism induced by L-thyroxin. The study was carried out on 30 male Sprague-Dawley rats. They were divided into three groups as control, sham hyperthyroidism and hyperthyroidism. Malondialdehyde (MDA) and glutathione (GSH) levels in rat tissues were determined at the end of a 3-weeks period of L-thyroxin administration. It was observed that MDA levels in the hyperthyroidism group were significantly higher in the cerebral cortex, liver and ventriculer tissue of heart (p < 0.001) than in the control and in sham hyperthyroidism groups. GSH levels were higher in the hyperthyroidism group than in control and sham hyperthyroidism groups in all tissues (p < 0.001). Results demonstrate that hyperthyroidism induced by L-thyroxin activates both oxidant and antioxidant systems in cerebral, hepatic and cardiac tissues. However, the increase in antioxidant activity cannot adequately prevent oxidative damage.

Hyperthyroidism and cerebral venous thrombosis.

PubMed

Mouton, S; Nighoghossian, N; Berruyer, M; Derex, L; Philippeau, F; Cakmak, S; Honnorat, J; Hermier, M; Trouillas, P

2005-01-01

The demonstration of an underlying prothrombotic condition in cerebral venous thrombosis (CVT) may have important practical consequences in terms of prevention. Thyrotoxicosis through a hypercoagulable state may be a predisposing factor for CVT. The authors present the cases of 4 patients who developed CVT and hyperthyroidism. At the acute stage, hyperthyroidism was associated with an increase in factor VIII (FVIII). At follow-up, FVIII level remained increased in 2 patients. Hyperthyroidism may have an impact on FVIII level. Accordingly in patients with hyperthyroidism and neurological symptoms, the diagnosis of CVT should be considered and an exhaustive coagulation screening may be appropriate. (c) 2005 S. Karger AG, Basel.

Hyperthyroidism: diagnosis and management of Graves' disease.

PubMed

Schilling, J S

1997-06-01

Hyperthyroidism, or thyrotoxicosis, results when the body's tissues are exposed to excessive levels of thyroid hormone. Hyperthyroidism affects 2% of women but only one-tenth as many men. Graves' disease is the most common form of hyperthyroidism, often occurring in young adults. It is an autoimmune disorder with an important genetic component. Hyperthyroidism's hallmarks include goiter and myriad signs and symptoms related to increased metabolic activity in virtually all body tissues. Increased sensitivity to circulating catecholamines adds to the clinical picture. Diagnosed by patient history, physical examination, and laboratory tests, Graves' disease is treated with antithyroid drugs, radioactive iodine, and/or surgery, plus supportive therapy. A good treatment outcome can be expected; long-term follow-up is indicated.

Alterations in monoamines level in discrete brain regions and other peripheral tissues in young and adult male rats during experimental hyperthyroidism.

PubMed

Hassan, Wafaa A; Rahman, Taghride Abdel; Aly, Mona S; Shahat, Asmaa S

2013-08-01

The present study was conducted to investigate the effect of experimentally-induced hyperthyroidism on dopamine (DA), norepinephrine (NE) and serotonin (5-HT) levels in different brain regions as well as in blood plasma, cardiac muscle and adrenal gland of young and adult male albino rats (60 rats of each age). Hyperthyroidism was induced by daily s.c. injection of L-thyroxine (L-T4, 500 μg/kg body wt.) for 21 consecutive days. Induction of hyperthyroidism caused a significant elevation in DA and 5-HT levels in most of the tissues studied of both young and adult animals after 7, 14, and 21 days. NE content significantly decreased after 21 days in most of the brain regions examined and after 14 and 21 days in blood plasma of young rats following hyperthyroidism. In adult rats, NE content decreased after 14 and 21 days in cardiac muscle and after 21 days only in adrenal gland. It may be suggested that the changes in monoamines level induced by hyperthyroidism may be due to disturbance in the synthesis, turnover and release of these amines through the neurons impairment or may attributed to an alteration pattern of their synthesis and/or degradative enzymes or changes in the sensitivity of their receptors. Copyright © 2013 ISDN. Published by Elsevier Ltd. All rights reserved.

Effects of experimentally induced mild hyperthyroidism on growth hormone and insulin secretion and sex steroid levels in healthy young men.

PubMed

Lovejoy, J C; Smith, S R; Bray, G A; Veldhuis, J D; Rood, J C; Tulley, R

1997-12-01

Although triiodothyronine (T3) exerts major regulatory actions in both animals and humans, most clinical studies of T3 administration have been relatively short-term. The present study examined the effects of more than 2 months (63 days) of low-dose T3 treatment on overnight pulsatile growth hormone (GH) secretion, short-term insulin secretion, and of sex steroid levels in seven healthy, lean men studied at an inpatient metabolic unit. At baseline, there were strong correlations between sex hormone-binding globulin (SHBG) and several measures of GH production, including total GH production (r = .99), GH interburst interval (r = -.75), and GH mass (r = .82). SHBG was also inversely correlated with basal insulin secretion (r = -.74). There was a 42% increase in serum levels of total testosterone (18.5 +/- 1.3 to 26.3 +/- 1.8 nmol/L, P = .005) and a 150% increase in SHBG (18.0 +/- 2.2 to 44.9 +/- 7.0 nmol/L, P = .008) following T3 treatment. Estradiol and free testosterone levels were unchanged by treatment, although free testosterone decreased from 142.8 +/- 18.4 to 137.3 +/- 19.5 pmol/L. T3 treatment significantly reduced the GH interburst interval (P < .05) and produced slight increases in the measures of GH secretion. There were no statistically significant effects of T3 treatment on insulin secretion, although insulin peak amplitude, mass secreted per burst, and total production all decreased. We conclude that experimentally induced T3 excess in healthy men produces significant and sustained changes in sex hormone levels and GH secretion. Furthermore, there are strong associations between SHBG and both GH and insulin secretion independent of thyroid hormone excess that require additional study.

Leptin, NPY, Melatonin and Zinc Levels in Experimental Hypothyroidism and Hyperthyroidism: The Relation to Zinc.

PubMed

Baltaci, Abdulkerim Kasım; Mogulkoc, Rasim

2017-06-01

Since zinc mediates the effects of many hormones or is found in the structure of numerous hormone receptors, zinc deficiency leads to various functional impairments in the hormone balance. And also thyroid hormones have important activity on metabolism and feeding. NPY and leptin are affective on food intake and regulation of appetite. The present study is conducted to determine how zinc supplementation and deficiency affect thyroid hormones (free and total T3 and T4), melatonin, leptin, and NPY levels in thyroid dysfunction in rats. The experiment groups in the study were formed as follows: Control (C); Hypothyroidism (PTU); Hypothyroidism+Zinc (PTU+Zn); Hypothyroidism+Zinc deficient; Hyperthyroidism (H); Hyperthyroidism+Zinc (H+Zn); and Hyperthyroidism+Zinc deficient. Thyroid hormone parameters (FT 3 , FT 4 , TT 3 , and TT 4 ) were found to be reduced in hypothyroidism groups and elevated in the hyperthyroidism groups. Melatonin values increased in hyperthyroidism and decreased in hypothyroidism. Leptin and NPY levels both increased in hypo- and hyperthyroidism. Zinc levels, on the other hand, decreased in hypothyroidism and increased in hyperthyroidism. Zinc supplementation, particularly when thyroid function is impaired, has been demonstrated to markedly prevent these changes.

Effects of hyperthyroidism on hand grip strength and function.

PubMed

Erkol İnal, Esra; Çarlı, Alparslan Bayram; Çanak, Sultan; Aksu, Oğuzhan; Köroğlu, Banu Kale; Savaş, Serpil

2015-01-01

Hyperthyroidism is a pathologic condition in which the body is exposed to excessive amounts of circulating thyroid hormones. Skeletal muscle is one of the major target organs of thyroid hormones. We evaluated hand grip strength and function in patients with overt hyperthyroidism. Fifty-one patients newly diagnosed with hyperthyroidism and 44 healthy controls participated in this study. Age, height, weight, and dominant hand of all participants were recorded. The diagnosis of hyperthyroidism was confirmed by clinical examination and laboratory tests. Hand grip strength was tested at the dominant hand with a Jamar hand dynamometer. The grooved pegboard test (PGT) was used to evaluate hand dexterity. The Duruöz Hand Index (DHI) was used to assess hand function. No significant differences were found in terms of clinical and demographic findings between the patients with hyperthyroidism and healthy controls (p > 0.05). Significant differences were found between the patients with hyperthyroidism and healthy controls regarding PGT and DHI scores (p < 0.05). Hyperthyroidism seemed to affect hand dexterity and function more than hand grip strength and seemed to be associated with reduced physical function more than muscle strength. This may also indicate that patients with hyperthyroidism should be evaluated by multidisplinary modalities.

Role of Oxidative Stress in Thyroid Hormone-Induced Cardiomyocyte Hypertrophy and Associated Cardiac Dysfunction: An Undisclosed Story

PubMed Central

Elnakish, Mohammad T.; Ahmed, Amany A. E.; Mohler, Peter J.; Janssen, Paul M. L.

2015-01-01

Cardiac hypertrophy is the most documented cardiomyopathy following hyperthyroidism in experimental animals. Thyroid hormone-induced cardiac hypertrophy is described as a relative ventricular hypertrophy that encompasses the whole heart and is linked with contractile abnormalities in both right and left ventricles. The increase in oxidative stress that takes place in experimental hyperthyroidism proposes that reactive oxygen species are key players in the cardiomyopathy frequently reported in this endocrine disorder. The goal of this review is to shed light on the effects of thyroid hormones on the development of oxidative stress in the heart along with the subsequent cellular and molecular changes. In particular, we will review the role of thyroid hormone-induced oxidative stress in the development of cardiomyocyte hypertrophy and associated cardiac dysfunction, as well as the potential effectiveness of antioxidant treatments in attenuating these hyperthyroidism-induced abnormalities in experimental animal models. PMID:26146529

Pulmonary hypertension and isolated right heart failure complicating amiodarone induced hyperthyroidism.

PubMed

Wong, Sean-Man; Tse, Hung-Fat; Siu, Chung-Wah

2012-03-01

Hyperthyroidism is a common side effect encountered in patients prescribed long-term amiodarone therapy for cardiac arrhythmias. We previously studied 354 patients prescribed amiodarone in whom the occurrence of hyperthyroidism was associated with major adverse cardiovascular events including heart failure, myocardial infarction, ventricular arrhythmias, stroke and even death [1]. We now present a case of amiodarone-induced hyperthyroidism complicated by isolated right heart failure and pulmonary hypertension that resolved with treatment of hyperthyroidism. Detailed quantitative echocardiography enables improved understanding of the haemodynamic mechanisms underlying the condition. Copyright © 2011 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

[Subclinical hyperthyroidism].

PubMed

Tomkowicz, Aneta; Bednarek-Tupikowska, Grazyna

2011-01-01

Subclinical hyperthyroidism is a clinical condition with a laboratory diagnosis defined as a suppressed below the normal range TSH level and normal free thyroxine and triiodothyronine levels. The condition is frequently recognized but its long-term clinical consequences are constantly debated. There is little good evidence available to guide the management of patients with subclinical hyperthyroidism. This review summarizes current state of knowledge on the prevalence, aetiology, clinical consequences and treatment of subclinical hypertyroidism.

40 CFR 63.2990 - Can I conduct short-term experimental production runs that cause parameters to deviate from...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Can I conduct short-term experimental... I conduct short-term experimental production runs that cause parameters to deviate from operating limits? With the approval of the Administrator, you may conduct short-term experimental production runs...

40 CFR 63.2990 - Can I conduct short-term experimental production runs that cause parameters to deviate from...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Can I conduct short-term experimental... I conduct short-term experimental production runs that cause parameters to deviate from operating limits? With the approval of the Administrator, you may conduct short-term experimental production runs...

Melatonin alleviates hyperthyroidism induced oxidative stress and neuronal cell death in hippocampus of aged female golden hamster, Mesocricetus auratus.

PubMed

Rao, Geeta; Verma, Rakesh; Mukherjee, Arun; Haldar, Chandana; Agrawal, Neeraj Kumar

2016-09-01

Oxidative stress is a well known phenomenon under hyperthyroid condition that induces various physiological and neural problems with a higher prevalence in females. We, therefore investigated the antioxidant potential of melatonin (Mel) on hyperthyroidism-induced oxidative stress and neuronal cell death in the hippocampus region of brain (cognition and memory centre) of aged female golden hamster, Mesocricetus auratus. Aged female hamsters were randomly divided into four experimental groups (n=7); group-I: control, group-II: Melatonin (5mgkg(-1)day(-1), i.p., for one week), group-III: Hyperthyroid (100μg kg(-1)day(-1), i.p., for two weeks) and group-IV- Hyper+Mel. Hormonal profiles (thyroid and melatonin), activity of antioxidant enzymes (SOD, CAT and GPX), lipid peroxidation level (TBARS) and the specific apoptotic markers (Bax/Bcl-2 ratio and Caspase-3) expression were evaluated. A significant increase in the profile of total thyroid hormone (tT3 and tT4) in hyperthyroidic group as compared to control while tT3 significantly decreased in melatonin treated hyperthyroidic group. However, Mel level significantly decreased in hyperthyroidic group but increased in melatonin treated hyperthyroidic group. Further, the number of immune-positive cells for thyroid hormone receptor-alpha (TR-α) decreased in the hippocampus of hyperthyroidic group and increased in melatonin treated hyperthyroidic group. Profiles of antioxidant enzymes showed a significant decrease in hyperthyroidic group with a simultaneous increase in lipid peroxidation (TBARS). Melatonin treatment to hyperthyroidic group lead to decreased TBARS level with a concomitant increase in antioxidant enzyme activity. Moreover, increased expression of Bax/Bcl-2 ratio and Caspase-3, in hyperthyroidic group had elevated neuronal cell death in hippocampal area and melatonin treatment reduced its expression in hyperthyroidic group. Our findings thus indicate that melatonin reduced the hyperthyroidism-induced oxidative stress and neuronal cell death in the hippocampus region of brain, suggesting a novel therapeutic approach of melatonin for management of cognition and memory function in females under hyperthyroid condition. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of a protein-free diet on muscle protein turnover and nitrogen conservation in euthyroid and hyperthyroid rats.

PubMed Central

Carter, W J; van der Weijden Benjamin, W S; Faas, F H

1984-01-01

Although protein turnover in skeletal muscle is increased in hyperthyroidism and decreased in hypothyroidism, a deficient protein intake tends to increase serum T3 (tri-iodothyronine) while decreasing muscle protein turnover. To determine whether this diet-induced decrease in protein turnover can occur independent of thyroid status, we have examined muscle protein turnover and nitrogen conservation in hyperthyroid rats fed on a protein-free diet. After inducing hyperthyroidism by giving 20 micrograms of T3/100g body wt. daily for 7 days, groups of euthyroid and hyperthyroid animals were divided into subgroups fed on basal and protein-free diets. Muscle protein turnover was measured by N tau-methylhistidine excretion and [14C]tyrosine infusion. Urinary nitrogen output of euthyroid and hyperthyroid animals fed on the protein-free diet was also measured. Although hyperthyroidism increased the baseline rates of muscle protein synthesis and degradation, it did not prevent a decrease in these values in response to protein depletion. Furthermore, hyperthyroid rats showed greatly decreased nitrogen excretion in response to the protein-free diet, although not to values for euthyroid rats. These findings suggest that protein depletion made the experimental animals less responsive to the protein-catabolic effects of T3. PMID:6696742

40 CFR 63.2990 - Can I conduct short-term experimental production runs that cause parameters to deviate from...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Can I conduct short-term experimental... Plan § 63.2990 Can I conduct short-term experimental production runs that cause parameters to deviate from operating limits? With the approval of the Administrator, you may conduct short-term experimental...

Redox status and pro-survival/pro-apoptotic protein expression in the early cardiac hypertrophy induced by experimental hyperthyroidism.

PubMed

Fernandes, R O; Dreher, G J; Schenkel, P C; Fernandes, T R G; Ribeiro, M F M; Araujo, A S R; Belló-Klein, A

2011-10-01

This study was conducted to analyse the redox status and redox-sensitive proteins that may contribute to a non-genomic mechanism of cardiac hypertrophy induction by hyperthyroidism. Wistar rats, treated with L-thyroxine (T4) during 2 weeks (12 mg·l(-1) in drinking water), presented cardiac hypertrophy (68% higher than control), without signals of liver or lung congestion. Myocardial reduction of the reduced glutathione: oxidized glutathione (GSSG) ratio (45%) (redox status) and elevation in hydrogen peroxide concentration (H(2) O(2) ) (28%) were observed in hyperthyroid as compared with the control. No significant difference was found in thioredoxin (Trx), Trx reductase activity and Nrf2 (a transcriptional factor) protein expression between groups. Redox-sensitive proteins, quantified using Western blot, presented the following results: increased p-ERK: total extracellular-regulated kinase (ERK) (200%) and Bax:Bcl-2 (62%) ratios and reduced total-Akt (63%) and p-Akt (53%) expressions in the hyperthyroid rats as compared with the control. The redox imbalance, associated with increased immunocontent of a protein related to maladaptative growth (ERK) and reduced immunocontent of protein related to cytoprotection/survival (Akt), may suggest that the molecular scenario could favour the decompensation process of cardiac hypertrophy induced by experimental hyperthyroidism. Copyright © 2011 John Wiley & Sons, Ltd.

Shortness of Breath and Lower Limb Edema in a 54-Year-Old Woman, Is There Any Cure?

PubMed

Frogoudaki, Alexandra; Triantafyllis, Andreas S; Vassilatou, Evangeline; Tsamakis, Charalampos; Zacharoulis, Achilles; Lekakis, John

2016-02-01

Pulmonary hypertension is common among patients with hyperthyroidism, and Graves' disease constitutes the most common cause of thyrotoxicosis. We report the case of a female patient admitted to the cardiology department with shortness of breath and pretibial myxedema. The diagnostic work-up revealed combined pre- and post-capillary pulmonary hypertension due to Graves' disease superimposed on left ventricular diastolic dysfunction. Restoration of thyroid function led to normalization of the pulmonary pressure and symptom resolution. Thyroid disease is a cause of reversible pulmonary hypertension and thus should be appropriately considered in the diagnostic algorithm in patients with dyspnea, clinical signs of hyperthyroidism and elevated pulmonary pressure.

[The activity of glutathione antioxidant system at melaksen and valdoxan action under experimental hyperthyroidism in rats].

PubMed

Gorbenko, M V; Popova, T N; Shul'gin, K K; Popov, S S

2013-01-01

Investigation of glutathione antioxidant system activity and diene conjugates content in rats liver and blood serum at the influence of melaksen and valdoxan under experimental hyperthyroidism (EG) has been revealed. It has been established that the activities of glutathione reductase (GR), glutathione peroxidase (GP) and glutathione transferase (GT), growing at pathological conditions, change to the side of control value at these substunces introduction. Reduced glutathione content (GSH) at melaxen and valdoxan action increased compared with values under the pathology, that, obviously, could be associated with a reduction of its spending on the detoxication of free radical oxidation (FRO) toxic products. Diene conjugates level in rats liver and blood serum, increasing at experimental hyperthyroidism conditions, under introduction of melatonin level correcting drugs, also approached to the control meaning. Results of the study indicate on positive effect of melaxen and valdoxan on free radical homeostasis, that appears to be accompanied by decrease of load on the glutathione antioxidant system in comparison with the pathology.

Experimental hyperthyroidism in rats increases the expression of the ubiquitin ligases atrogin-1 and MuRF1 and stimulates multiple proteolytic pathways in skeletal muscle.

PubMed

O'Neal, Patrick; Alamdari, Nima; Smith, Ira; Poylin, Vitaliy; Menconi, Michael; Hasselgren, Per-Olof

2009-11-01

Muscle wasting is commonly seen in patients with hyperthyroidism and is mainly caused by stimulated muscle proteolysis. Loss of muscle mass in several catabolic conditions is associated with increased expression of the muscle-specific ubiquitin ligases atrogin-1 and MuRF1 but it is not known if atrogin-1 and MuRF1 are upregulated in hyperthyroidism. In addition, it is not known if thyroid hormone increases the activity of proteolytic mechanisms other than the ubiquitin-proteasome pathway. We tested the hypotheses that experimental hyperthyroidism in rats, induced by daily intraperitoneal injections of 100 microg/100 g body weight of triiodothyronine (T3), upregulates the expression of atrogin-1 and MuRF1 in skeletal muscle and stimulates lysosomal, including cathepsin L, calpain-, and caspase-3-dependent protein breakdown in addition to proteasome-dependent protein breakdown. Treatment of rats with T3 for 3 days resulted in an approximately twofold increase in atrogin-1 and MuRF1 mRNA levels. The same treatment increased proteasome-, cathepsin L-, and calpain-dependent proteolytic rates by approximately 40% but did not influence caspase-3-dependent proteolysis. The expression of atrogin-1 and MuRF1 remained elevated during a more prolonged period (7 days) of T3 treatment. The results provide support for a role of the ubiquitin-proteasome pathway in muscle wasting during hyperthyroidism and suggest that other proteolytic pathways as well may be activated in the hyperthyroid state. (c) 2009 Wiley-Liss, Inc.

Hyperthyroidism and pulmonary hypertension: an important association.

PubMed

Vallabhajosula, Sailaja; Radhi, Saba; Cevik, Cihan; Alalawi, Raed; Raj, Rishi; Nugent, Kenneth

2011-12-01

Pulmonary hypertension is a complex disorder with multiple etiologies. The World Health Organization Group 5 (unclear multifactorial mechanisms) includes patients with thyroid disorders. The authors reviewed the literature on the association between hyperthyroidism and pulmonary hypertension and identified 20 publications reporting 164 patients with treatment outcomes. The systolic pulmonary artery (PA) pressures in these patients ranged from 28 to 78 mm Hg. They were treated with antithyroid medications, radioactive iodine and surgery. The mean pretherapy PA systolic pressure was 39 mm Hg; the mean posttreatment pressure was 30 mm Hg. Pulmonary hypertension should be considered in hyperthyroid patients with dyspnea. All patients with pulmonary hypertension should be screened for hyperthyroidism, because the treatment of hyperthyroidism can reduce PA pressures, potentially avoid the side-effects and costs with current therapies for pulmonary hypertension and limit the consequences of untreated hyperthyroidism. However, the long-term outcome in these patients is uncertain, and this issue needs more study. Changes in the pulmonary circulation and molecular regulators of vascular remodeling likely explain this association.

[Neonatal hyperthyroidism and maternal Graves disease].

PubMed

Ben Ameur, K; Chioukh, F Z; Marmouch, H; Ben Hamida, H; Bizid, M; Monastiri, K

2015-04-01

The onset of Graves disease during pregnancy exposes the neonate to the risk of hyperthyroidism. The newborn must be monitored and treatment modalities known to ensure early treatment of the newborn. We report on the case of an infant born at term of a mother with Graves disease discovered during pregnancy. He was asymptomatic during the first days of life, before declaring the disease. Neonatal hyperthyroidism was confirmed by hormonal assays. Hyperthyroidism was treated with antithyroid drugs and propranolol with a satisfactory clinical and biological course. Neonatal hyperthyroidism should be systematically sought in infants born to a mother with Graves disease. The absence of clinical signs during the first days of life does not exclude the diagnosis. The duration of monitoring should be decided according to the results of the first hormonal balance tests. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Graves' Disease that Developed Shortly after Surgery for Thyroid Cancer.

PubMed

Yu, Hea Min; Park, Soon Hyun; Lee, Jae Min; Park, Kang Seo

2013-09-01

Graves' disease is an autoimmune disorder that may present with various clinical manifestations of hyperthyroidism. Patients with Graves' disease have a greater number of thyroid nodules and a higher incidence of thyroid cancer compared with patients with normal thyroid activity. However, cases in which patients are diagnosed with recurrence of Graves' disease shortly after partial thyroidectomy for thyroid cancer are very rare. Here we report a case of hyperthyroid Graves' disease that occurred after partial thyroidectomy for papillary thyroid cancer. In this case, the patient developed hyperthyroidism 9 months after right hemithyroidectomy, and antithyroglobulin autoantibody and thyroid stimulating hormone receptor stimulating autoantibody were positive. Therefore, we diagnosed Graves' disease on the basis of the laboratory test results and thyroid ultrasonography findings. The patient was treated with and maintained on antithyroid drugs. The mechanism of the recurrence of Graves' disease in this patient is still unclear. The mechanism may have been the improper response of the immune system after partial thyroidectomy. To precisely determine the mechanisms in Graves' disease after partial thyroidectomy, further studies based on a greater number of cases are needed.

Experimental hyperthyroidism and central mediators of stress axis and thyroid axis activity in common carp (Cyprinus carpio L.).

PubMed

Geven, Edwin J W; Verkaar, Folkert; Flik, Gert; Klaren, Peter H M

2006-12-01

The effect of experimental hyperthyroidism, realized by T(4) injection, on central mediators of the hypothalamo-pituitary-interrenal axis (HPI-axis) in common carp (Cyprinus carpio L.) was studied. Our results show that hyperthyroidism evokes a marked 3.2-fold reduction in basal plasma cortisol levels. Corticotropin-releasing hormone-binding protein (CRH-BP) mRNA levels in the hypothalamus, measured by real-time quantitative PCR, were significantly elevated by 40%, but CRH, urotensin-I, prepro-TRH, prohormone convertase-1 (PC1), and POMC mRNA levels were unchanged. In the pituitary pars distalis, PC1, CRH receptor-1, and POMC mRNA levels were unaffected, as was ACTH content. Plasma alpha-MSH concentrations were significantly elevated by 30% in hyperthyroid fish, and this was reflected in PC1 and POMC mRNA levels in pituitary pars intermedia that were increased 1.5- and 2.4-fold respectively. The alpha-MSH content of the pars intermedia was unchanged. Hyperthyroidism has profound effects on the basal levels of a central mediator, i.e., CRH-BP, of HPI-axis function in unstressed carp in vivo, and we conclude that HPI- and hypothalamo-pituitary-thyroid-axis functions are strongly interrelated. We suggest that the changes in plasma cortisol, thyroid hormone, and alpha-MSH levels reflect their concerted actions on energy metabolism.

Experimentally induced hyperthyroidism influences oxidant and antioxidant status and impairs male gonadal functions in adult rats.

PubMed

Asker, M E; Hassan, W A; El-Kashlan, A M

2015-08-01

The objective of the present experiment was to study the effect of hyperthyroidism on male gonadal functions and oxidant/antioxidant biomarkers in testis of adult rats. Induction of hyperthyroidism by L-thyroxine (L-T4, 300 μg kg(-1) body weight) treatment once daily for 3 or 8 weeks caused a decrease in body weight gain as well as in absolute genital sex organs weight. The epididymal sperm counts and their motility were significantly decreased in a time-dependent manner following L-T4 treatment. Significant decline in serum levels of luteinising hormone, follicle stimulating hormone and testosterone along with significant increase in serum estradiol level was observed in hyperthyroid rats compared with euthyroid ones. Significant increase in malondialdehyde and nitric oxide concentration associated with significant decrease in superoxide dismutase and catalase activity was also noticed following hyperthyroidism induction. Both reduced glutathione content and glutathione peroxidase activity were increased in hyperthyroid rats compared with control rats. Marked histopathological alterations were observed in testicular section of hyperthyroid rats. These results provide evidence that hypermetabolic state induced by excess level of thyroid hormones may be a causative factor for the impairment of testicular physiology as a consequence of oxidative stress. © 2014 Blackwell Verlag GmbH.

Both hypothyroidism and hyperthyroidism increase plasma irisin levels in rats.

PubMed

Atici, Emine; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim; Menevse, Esma

2017-11-28

Background A recently discovered hormone, irisin is accepted to be significantly involved in the regulation of body weight. Thyroid functions may be, directly or indirectly, associated with irisin. Aim The aim of the present study is to determine the effect of experimental thyroid dysfunction on irisin levels in rats. Methods The study registered 40 adult male Sprague-Dawley rats, which were allocated to groups as follows: 1. Control; 2. Hypothyroidism induced by injection of 10 mg/kg/day intraperitoneal propylthiouracil (PTU) for 3 weeks; 3. Hypothyroidism (PTU 2 weeks) + L-thyroxin (1.5 mg/kg/day for 1 week); 4. Hyperthyroidism induced in rats by 3-week thyroxin (0.3 mg/kg/day); 5. Hyperthyroidism + PTU. At the end of the study, blood samples were collected to quantify free triiodothyronine (FT3), free triiodothyronine (FT4) and irisin levels. Results FT3 and FT4 levels were reduced in hypothyroidism and were significantly elevated in hyperthyroidism (p < 0.001). Irisin values, on the other hand, were found to be elevated in both hypothyroidism and hyperthyroidism groups (p < 0.001). Conclusion The results of the study suggest that irisin values increase in thyroid dysfunction, hypo- and hyperthyroidism, and that when hypothyroidism is corrected by thyroxin administration and hyperthyroidism by PTU injection, plasma irisin values go back to normal.

No impact of dietary iodine restriction in short term development of hypothyroidism following fixed dose radioactive iodine therapy for Graves' disease.

PubMed

Jacob, Jubbin Jagan; Stephen, Charles; Paul, Thomas V; Thomas, Nihal; Oommen, Regi; Seshadri, Mandalam S

2015-01-01

The increased incidence of autoimmune thyroid disease with increasing dietary iodine intake has been demonstrated both epidemiologically and experimentally. The hypothyroidism that occurs in the first year following radioactive iodine therapy is probably related to the destructive effects of the radiation and underlying ongoing autoimmunity. To study the outcomes at the end of six months after fixed dose I, (131)therapy for Graves' disease followed by an iodine restricted diet for a period of six months. Consecutive adult patients with Graves' disease planned for I(131) therapy were randomized either to receive instructions regarding dietary iodine restriction or no advice prior to fixed dose (5mCi) I(131) administration. Thyroid functions and urinary iodine indices were evaluated at 3(rd) and 6(th) month subsequently. Forty seven patients (13M and 34F) were assessed, 2 were excluded, 45 were randomized (Cases 24 and Controls 21) and 39 patients completed the study. Baseline data was comparable. Median urinary iodine concentration was 115 and 273 μg/gm creat (p = 0.00) among cases and controls respectively. Outcomes at the 3(rd) month were as follows (cases and controls); Euthyroid (10 and 6: P = 0.24), Hypothyroid (3 and 5: P = 0.38) and Hyperthyroid (7 and 8: P = 0.64). Outcomes at the end of six months were as follows (cases and controls); Euthyroid (10 and 5: P = 0.12), Hypothyroid (3 and 5: P = 0.38) and Hyperthyroid (7 and 9: P = 0.43). Of the hypothyroid patients 5 (cases 1 and controls 4: P = 0.13) required thyroxine replacement. There was no statistical significant difference in the outcome of patients with dietary iodine restriction following I(131) therapy for Graves' disease.

Cardiovascular morbidity and mortality in surgically treated hyperthyroidism - a nation-wide cohort study with a long-term follow-up.

PubMed

Ryödi, Essi; Salmi, Jorma; Jaatinen, Pia; Huhtala, Heini; Saaristo, Rauni; Välimäki, Matti; Auvinen, Anssi; Metso, Saara

2014-05-01

Previous studies suggest that patients with hyperthyroidism remain at an increased risk of cardiovascular morbidity even after restoring euthyroidism. The mechanisms of the increased risk and its dependency on the different treatment modalities of hyperthyroidism remain unclear. The aim of this long-term follow-up study was to compare the rate of hospitalizations for cardiovascular causes and the mortality in hyperthyroid patients treated surgically with an age- and gender-matched reference population. A population-based cohort study was conducted among 4334 hyperthyroid patients (median age 46 years) treated with thyroidectomy in 1986-2007 in Finland and among 12,991 reference subjects. Firstly, the hospitalizations due to cardiovascular diseases (CVD) were analysed until thyroidectomy. Secondly, the hazard ratios for any new hospitalization due to CVDs after the thyroidectomy were calculated in Cox regression analysis adjusted with the prevalent CVDs at the time of thyroidectomy. The risk of hospitalization due to all CVDs started to increase already 5 years before the thyroidectomy, and by the time of the operation, it was 50% higher in the hyperthyroid patients compared to the controls (P < 0·001). After the thyroidectomy, the hospitalizations due to all CVDs (HR 1·15), hypertension (HR 1·23), heart failure (HR 1·17) and valvular diseases or cardiomyopathies (HR 1·55) remained more frequent among the patients than among the controls for 20 years after thyroidectomy. The increased morbidity was not clearly related to the aetiology of hyperthyroidism. Despite the increased CVD morbidity among the patients, there was no difference in cardiovascular mortality. The present study shows that hyperthyroidism increases the risk of hospitalization due to CVDs and the risk is sustained up to two decades after effective surgical treatment. However, there was no excess CVD mortality in the middle-aged patient cohort studied. © 2013 John Wiley & Sons Ltd.

Effects of experimentally induced maternal hypothyroidism and hyperthyroidism on the development of rat offspring: I. The development of the thyroid hormones-neurotransmitters and adenosinergic system interactions.

PubMed

Ahmed, O M; Abd El-Tawab, S M; Ahmed, R G

2010-10-01

The adequate functioning of the maternal thyroid gland plays an important role to ensure that the offspring develop normally. Thus, maternal hypo- and hyperthyroidism are used from the gestation day 1 to lactation day 21, in general, to recognize the alleged association of offspring abnormalities associated with the different thyroid status. In maternal rats during pregnancy and lactation, hypothyroidism in one group was performed by antithyroid drug, methimazole (MMI) that was added in drinking water at concentration 0.02% and hyperthyroidism in the other group was induced by exogenous thyroxine (T4) (from 50 microg to 200 microg/kg body weight) intragastric administration beside adding 0.002% T4 to the drinking water. The hypothyroid and hyperthyroid states in mothers during pregnancy and lactation periods were confirmed by measuring total thyroxine (TT4) and triiodothyronine (TT3) at gestational day 10 and 10 days post-partum, respectively; the effect was more pronounced at the later period than the first. In offspring of control maternal rats, the free thyroxine (FT4), free triiodothyronine (FT3), thyrotropin (TSH) and growth hormone (GH) concentrations were pronouncedly increased as the age progressed from 1 to 3 weeks. In hypothyroid group, a marked decrease in serum FT3, FT4 and GH levels was observed while there was a significant increase in TSH level with age progress as compared with the corresponding control. The reverse pattern to latter state was recorded in hyperthyroid group. The thyroid gland of offspring of hypothyroid group, exhibited some histopathological changes as luminal obliteration of follicles, hyperplasia, fibroblastic proliferation and some degenerative changes throughout the experimental period. The offspring of hyperthyroid rats showed larger and less thyroid follicles with flattened cell lining epithelium, decreased thyroid gland size and some degenerative changes along the experimental period. On the other hand, the biochemical data revealed that in control offspring, the levels of iodothyronine 5'-monodeiodinase (5'-DI), monoamines, gamma-aminobutyric acid (GABA), acetylcholinesterase (AchE), ATPase-enzymes (Na(+),K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase) follow a synchronized course of development in all investigated brain regions (cerebrum, cerebellum and medulla oblongata). In addition, the depression in 5'-DI activity, monoamines levels with age progress in all investigated regions, was more pronounced in hypothyroid offspring, while they were increased significantly in hyperthyroid ones in comparison with their respective controls. Conversely, the reverse pattern was recorded in level of the inhibitory transmitter, GABA while there was a disturbance in AchE and ATPases activities in both treated groups along the experimental period in all studied regions. In conclusion, the hypothyroid status during pregnancy and lactation produced inhibitory effects on monoamines, AchE and ATPases and excitatory actions on GABA in different brain regions of the offspring while the hyperthyroid state induced a reverse effect. Thus, the maternal hypothyroidism and hyperthyroidism may cause a number of biochemical disturbances in different brain regions of their offspring and may lead to a pathophysiological state. These alterations were age dependent. Copyright 2010 ISDN. Published by Elsevier Ltd. All rights reserved.

The effects of experimentally induced hyperthyroidism on the diving physiology of harbor seals (Phoca vitulina)

PubMed Central

Weingartner, Gundula M.; Thornton, Sheila J.; Andrews, Russel D.; Enstipp, Manfred R.; Barts, Agnieszka D.; Hochachka, Peter W.

2012-01-01

Many phocid seals are expert divers that remain submerged longer than expected based on estimates of oxygen storage and utilization. This discrepancy is most likely due to an overestimation of diving metabolic rate. During diving, a selective redistribution of blood flow occurs, which may result in reduced metabolism in the hypoperfused tissues and a possible decline in whole-body metabolism to below the resting level (hypometabolism). Thyroid hormones are crucial in regulation of energy metabolism in vertebrates and therefore their control might be an important part of achieving a hypometabolic state during diving. To investigate the effect of thyroid hormones on diving physiology of phocid seals, we measured oxygen consumption, heart rate, and post-dive lactate concentrations in five harbor seals (Phoca vitulina) conducting 5 min dives on command, in both euthyroid and experimentally induced hyperthyroid states. Oxygen consumption during diving was significantly reduced (by 25%) in both euthyroid and hyperthyroid states, confirming that metabolic rate during diving falls below resting levels. Hyperthyroidism increased oxygen consumption (by 7–8%) when resting in water and during diving, compared with the euthyroid state, illustrating the marked effect of thyroid hormones on metabolic rate. Consequently, post-dive lactate concentrations were significantly increased in the hyperthyroid state, suggesting that the greater oxygen consumption rates forced seals to make increased use of anaerobic metabolic pathways. During diving, hyperthyroid seals also exhibited a more profound decline in heart rate than seals in the euthyroid state, indicating that these seals were pushed toward their aerobic limit and required a more pronounced cardiovascular response. Our results demonstrate the powerful role of thyroid hormones in metabolic regulation and support the hypothesis that thyroid hormones play a role in modulating the at-sea metabolism of phocid seals. PMID:23060807

Selective modification of the pyruvate dehydrogenase kinase isoform profile in skeletal muscle in hyperthyroidism: implications for the regulatory impact of glucose on fatty acid oxidation.

PubMed

Sugden, M C; Lall, H S; Harris, R A; Holness, M J

2000-11-01

The pyruvate dehydrogenase kinases (PDK1-4) regulate glucose oxidation through inhibitory phosphorylation of the pyruvate dehydrogenase complex (PDC). Immunoblot analysis with antibodies raised against recombinant PDK isoforms demonstrated changes in PDK isoform expression in response to experimental hyperthyroidism (100 microg/100 g body weight; 3 days) that was selective for fast-twitch vs slow-twitch skeletal muscle in that PDK2 expression was increased in the fast-twitch skeletal muscle (the anterior tibialis) (by 1. 6-fold; P<0.05) but not in the slow-twitch muscle (the soleus). PDK4 protein expression was increased by experimental hyperthyroidism in both muscle types, there being a greater response in the anterior tibialis (4.2-fold increase; P<0.05) than in the soleus (3.2-fold increase; P<0.05). The hyperthyroidism-associated up-regulation of PDK4 expression was observed in conjunction with suppression of skeletal-muscle PDC activity, but not suppression of glucose uptake/phosphorylation, as measured in vivo in conscious unrestrained rats (using the 2-[(3)H]deoxyglucose technique). We propose that increased PDK isoform expression contributes to the pathology of hyperthyroidism and to PDC inactivation by facilitating the operation of the glucose --> lactate --> glucose (Cori) and glucose --> alanine --> glucose cycles. We also propose that enhanced relative expression of the pyruvate-insensitive PDK isoform (PDK4) in skeletal muscle in hyperthyroidism uncouples glycolytic flux from pyruvate oxidation, sparing pyruvate for non-oxidative entry into the tricarboxylic acid (TCA) cycle, and thereby supporting entry of acetyl-CoA (derived from fatty acid oxidation) into the TCA cycle.

Low circulating IGF-I levels in hyperthyroidism are associated with decreased GH response to GH-releasing hormone.

PubMed

Ramos-Dias, J C; Yateman, M; Camacho-Hübner, C; Grossman, A; Lengyel, A M

1995-11-01

Several abnormalities in the GH response to pharmacological stimuli have been described in hyperthyroidism. Both normal and high serum IGF-I levels have been reported, as well as a decrease in IGF-I bioactivity. We have evaluated the GH response to GH-releasing hormone (GHRH) in hyperthyroid patients and the effects of hyperthyroidism on serum IGF-I levels. The possible relations between nutritional status, thyroid hormones and IGF-I levels were also investigated. We also studied the influence of long-term beta-adrenoceptor blockade on the GH response to GHRH in these patients. In 18 hyperthyroid patients and in 12 control subjects, GHRH (100 micrograms) was administered as an i.v. bolus injection. Eight hyperthyroid patients and 8 control subjects received 50 micrograms GHRH i.v. Seven hyperthyroid patients were reevaluated after beta-adrenoceptor blockade. IGF-I and albumin levels were measured initially in all hyperthyroid patients and control subjects. Body composition was determined in 11 hyperthyroid patients and in a group of 33 matched normal controls. Hyperthyroid patients were compared to control subjects. GH, TSH and free T4 were measured by immunofluorometric assay. IGF-I, total T3 and total T4 were measured by radioimmunoassay. Body composition was determined using a dual-energy X-ray absorptiometer. The GH response to 100 micrograms GHRH in hyperthyroid patients was blunted compared to control subjects. The mean peak GH levels and the area under the curve were significantly lower in hyperthyroid patients compared to control subjects (11 +/- 1 vs 27 +/- 5 micrograms/l and 820 +/- 113 vs 1879 +/- 355 micrograms/l 120 min, respectively; P < 0.01). IGF-I levels were significantly reduced in hyperthyroid patients compared to controls (131 +/- 10 vs 201 +/- 16 micrograms/l, respectively; P < 0.01). Ideal body weight, serum albumin levels and the lean body mass were also reduced in hyperthyroid patients. After beta-adrenoceptor blockade there were no changes in the blunted GH response to GHRH in hyperthyroid patients. Our data suggest that the blunted GH response to GHRH in hyperthyroidism is apparently not related to circulating IGF-I levels. It is possible that nutritional factors could play a role in the reduced circulating IGF-I levels found in these patients.

Hepatic amino nitrogen conversion and organ N-contents in hypothyroidism, with thyroxine replacement, and in hyperthyroid rats.

PubMed

Grøfte, T; Wolthers, T; Jensen, D S; Møller, N; Jørgensen, J O; Orskov, H; Vilstrup, H

1997-02-01

The role of thyroid hormones in the regulation of hepatic conversions of amino nitrogen to urea is unresolved. The present study was designed to assess ureagenesis in rats with experimentally well-established hypo- and hyperthyroidism. The possible role of propylthiuracil (PTU), used for induction of hypothyroidism, was ascertained during thyroxine replacement of PTU treated hypothyroid rats. Basal blood amino nitrogen concentrations (AAN), the urea nitrogen synthesis rate (UNSR) and the maximal hepatic capacity for urea nitrogen synthesis (CUNS) obtained during alanine infusion were determined together with N-contents in the soleus muscle and kidneys in experimentally hypothyroid rats (n = 19), upon thyroxine replacement (n = 14) and in experimentally hyperthyroid rats (n = 19). Hypothyroidism was induced by adding propylthiouracil (0.05%) to the drinking water for 5 weeks. Hyperthyroidism was induced by thyroxine 100 micrograms/100 g body weight. During hyperthyroidism, T3 fell to less than 10%, food intake was halved, and body weight fell by 13%. Basal blood AAN fell by 25% (p < 0.01), UNSR more than doubled (p < 0.01), and CUNS rose by 45% (p < 0.05). N-contents of the soleus muscle fell by 13% and by 20% in kidneys, respectively (p < 0.05). Thyroxine replacement normalized AAN, UNSR, CUNS and reduced N-loss to 7% in the soleus muscle (NS) and kidneys (p < 0.05), respectively. During hyperthyroidism, T3 rose five-fold, food intake rose by two thirds, and body weight fell by 10%. Basal AAN rose by 20% (p < 0.05), UNSR doubled (p < 0.01), and CUNS rose by 25% (p < 0.05). N-contents of the soleus muscle decreased by 19%, whereas kidney N-contents increased by 25% (p < 0.05). Overall liver function assessed by galactose elimination capacity did not differ among groups. Both conditions increased the rate of urea synthesis; in the hypothyroid state the hepatic waste of amino-N was limited by low blood concentration of amino-N, probably due to lower proteolysis. In the hyperthyroid state hepatic amino-N loss was aggravated by higher blood concentration of amino-N, probably due to higher proteolysis. This difference may explain the markedly different dietary nitrogen economy between the two groups. The findings suggest that distinct hepatic acceleration of urea synthesis may contribute to the protein loss seen in both myxedema and in thyrotoxicosis in humans.

Comparative study of the effects of experimentally induced hypothyroidism and hyperthyroidism in some brain regions in albino rats.

PubMed

El-Bakry, A M; El-Gareib, A W; Ahmed, R G

2010-08-01

Thyroid hormones (THs) play a crucial role in the development and physiological functioning of different body organs especially the brain. Therefore, the objective of this study was to show the histopathological effects of the different thyroid states on some brain regions (cerebrum and cerebellum) and the skeletal features of their newborns during the postnatal development from the 1st to 3rd week. The female white albino rats were allocated into 3 groups as follows: the experimental hypothyroidism group is induced by 0.02% methimazole (MMI) (w/v) in drinking water, while the experimental hyperthyroidism group is performed by exogenous T4 [from 50 to 200microg/kg body weight intragastric administration beside adding 0.002% T4 (w/v) to the drinking water] from the gestation day 1 to lactation day 21 and control group which received tap water. As well, both maternal hypo- and hyperthyroidism caused some malformation and developmental defects in the cerebellar and cerebral cortex of their newborns along the duration of the experiment. These degenerative symptoms became more prominent and widely spread at the 3rd postnatal week. Concomitantly, there were some degeneration, deformation and severe growth retardation in neurons of these regions in both treated groups throughout the experimental period. Moreover, the skeletal features of these newborns were accelerated in hyperthyroid group while these maturations were delayed partially in hypothyroid ones during the examined periods. These alterations, on both treated groups, were age and dose dependent. Thus, further studies need to be done to emphasize this concept. Published by Elsevier Ltd.

Short-Term Thyroid Hormone Excess Affects the Heart but Does not Affect Adrenal Activity in Rats

PubMed Central

Szkudlarek, Ariani Cavazzani; Aldenucci, Bruno; Miyagui, Nelson Itiro; Silva, Ilana Kassouf; Moraes, Rosana Nogueira; Ramos, Helton Estrela; Fogaça, Rosalva Tadeu Hochmuller

2014-01-01

Background Hyperthyroidism (Hy) exerts a broad range of influences on a variety of physiological parameters. Its disruptive effect on cardiovascular system is one of its most remarkable impacts. Moreover, Hy has been clinically associated with stress - induced hyperactivation of the hypothalamic-pituitary-adrenal axis. Objective Evaluate the impact of short-term Hy on cardiac performance and adrenal activity of rats. Methods Induction of Hy in Wistar rats through injections of T3 (150 µg/kg) for 10 days (hyperthyroid group - HG) or vehicle (control group). The cardiovascular performance was evaluated by: echocardiography (ECHO); heart weight/body weight (mg/gr) ratio; contractility of isolated papillary muscles (IPM) and direct measurement of blood pressures. Adrenal activity was evaluated by adrenal weight/body weight (mg/gr) ratio and 24-hour fecal corticosterone (FC) levels on the, 5th and 10th days of T3 treatment. Results In HG, the ECHO showed reduction of the End Systolic and End Diastolic Volumes, Ejection, Total Diastolic and Isovolumic Relaxation Times, Diastolic and Systolic Areas and E/A ratio. Heart Rate, Ejection Fraction and Cardiac Output increased. The heart weight/body weight ratio was higher. Similarly, in IPM, the maximum rate of force decay during relaxation was higher in all extracellular calcium concentrations. Systolic blood pressure (SBP) levels were higher. (p ≤ 0.05). On the other hand, there was no difference in the adrenal weight/body weight ratio or in the 24-hour FC levels. Conclusions Hy induces positive inotropic, chronotropic and lusitropic effects on the heart by direct effects of T3 and increases SBP. Those alterations are not correlated with changes in the adrenal activity. PMID:24676225

The effect of hyperthyroidism on procoagulant, anticoagulant and fibrinolytic factors: a systematic review and meta-analysis.

PubMed

Stuijver, Danka J F; van Zaane, Bregje; Romualdi, Erica; Brandjes, Dees P M; Gerdes, Victor E A; Squizzato, Alessandro

2012-12-01

Several coagulation and fibrinolytic parameters appear to be affected by thyroid hormone excess; however, the net effect on the haemostatic system remains unclear. We aimed to update our previous review and systematically summarise and meta-analyse the data by assessing the effects of thyrotoxicosis on the coagulation and fibrinolytic system in vivo . Data sources included MEDLINE (2006-2012), EMBASE (2006-2012), and reference lists. The sources were combined with our previous search containing studies from 1980-2006. Eligible studies were all observational or experimental studies. Two investigators independently extracted data and rated study quality. Weighted mean proportion and 95% confidence intervals were calculated and pooled using a fixed and a random-effects model. A total of 29 articles consisting of 51 studies were included, as in several articles more than one study was described. We included four intervention (before and after treatment in hyperthyroid patients), five cross-sectional (hyperthyroid subjects and euthyroid controls), and four experimental (before and after use of thyroid hormone in euthyroid subjects) medium/high quality studies for meta-analysis. We found that thyrotoxicosis shifts the haemostatic balance towards a hypercoagulable and hypofibrinolytic state with a rise in factors VIII and IX, fibrinogen, von Willebrand factor, and plasminogen activator inhibitor-1. This was observed in endogenous and exogenous thyrotoxicosis, and in subclinical as well as overt hyperthyroidism. We conclude that both subclinical and overt hyperthyroidism induce a prothrombotic state, which is therefore likely to be a risk factor for venous thrombosis.

New-onset atrial fibrillation is a predictor of subsequent hyperthyroidism: a nationwide cohort study.

PubMed

Selmer, Christian; Hansen, Morten Lock; Olesen, Jonas Bjerring; Mérie, Charlotte; Lindhardsen, Jesper; Olsen, Anne-Marie Schjerning; Madsen, Jesper Clausager; Schmidt, Ulla; Faber, Jens; Hansen, Peter Riis; Pedersen, Ole Dyg; Torp-Pedersen, Christian; Gislason, Gunnar Hilmar

2013-01-01

To examine the long-term risk of hyperthyroidism in patients admitted to hospital with new-onset AF. Hyperthyroidism is a well-known risk factor for atrial fibrillation (AF), but it is unknown whether new-onset AF predicts later-occurring hyperthyroidism. All patients admitted with new-onset AF in Denmark from 1997-2009, and their present and subsequent use of anti-thyroid medication was identified by individual-level linkage of nationwide registries. Patients with previous thyroid diagnosis or thyroid medication use were excluded. Development of hyperthyroidism was assessed as initiation of methimazole or propylthiouracil up to a 13-year period. Risk of hyperthyroidism was analysed by Poisson regression models adjusted for important confounders such as amiodarone treatment. Non-AF individuals from the general population served as reference. A total of 145,623 patients with new-onset AF were included (mean age 66.4 years [SD ±13.2] and 55.3% males) of whom 3% (4,620 events; 62.2% women) developed hyperthyroidism in the post-hospitalization period compared to 1% (48,609 events; 82% women) in the general population (n = 3,866,889). In both women and men we found a significantly increased risk of hyperthyroidism associated with new-onset AF compared to individuals in the general population. The highest risk was found in middle-aged men and was consistently increased throughout the 13-year period of observation. The results were confirmed in a substudy analysis of 527,352 patients who had thyroid screening done. New-onset AF seems to be a predictor of hyperthyroidism. Increased focus on subsequent risk of hyperthyroidism in patients with new-onset AF is warranted.

New-Onset Atrial Fibrillation Is a Predictor of Subsequent Hyperthyroidism: A Nationwide Cohort Study

PubMed Central

Selmer, Christian; Hansen, Morten Lock; Olesen, Jonas Bjerring; Mérie, Charlotte; Lindhardsen, Jesper; Olsen, Anne-Marie Schjerning; Madsen, Jesper Clausager; Schmidt, Ulla; Faber, Jens; Hansen, Peter Riis; Pedersen, Ole Dyg; Torp-Pedersen, Christian; Gislason, Gunnar Hilmar

2013-01-01

Aims To examine the long-term risk of hyperthyroidism in patients admitted to hospital with new-onset AF. Hyperthyroidism is a well-known risk factor for atrial fibrillation (AF), but it is unknown whether new-onset AF predicts later-occurring hyperthyroidism. Methods and Results All patients admitted with new-onset AF in Denmark from 1997–2009, and their present and subsequent use of anti-thyroid medication was identified by individual-level linkage of nationwide registries. Patients with previous thyroid diagnosis or thyroid medication use were excluded. Development of hyperthyroidism was assessed as initiation of methimazole or propylthiouracil up to a 13-year period. Risk of hyperthyroidism was analysed by Poisson regression models adjusted for important confounders such as amiodarone treatment. Non-AF individuals from the general population served as reference. A total of 145,623 patients with new-onset AF were included (mean age 66.4 years [SD ±13.2] and 55.3% males) of whom 3% (4,620 events; 62.2% women) developed hyperthyroidism in the post-hospitalization period compared to 1% (48,609 events; 82% women) in the general population (n = 3,866,889). In both women and men we found a significantly increased risk of hyperthyroidism associated with new-onset AF compared to individuals in the general population. The highest risk was found in middle-aged men and was consistently increased throughout the 13-year period of observation. The results were confirmed in a substudy analysis of 527,352 patients who had thyroid screening done. Conclusion New-onset AF seems to be a predictor of hyperthyroidism. Increased focus on subsequent risk of hyperthyroidism in patients with new-onset AF is warranted. PMID:23469097

Incidence of hypothyroidism occurring long after iodine-131 therapy for hyperthyroidism

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

Holm, L.E.; Lundell, G.; Israelsson, A.

1982-02-01

We have studied the long-term incidence of hypothyroidism in 4,473 formerly hyperthyroid patients given I-131 therapy between 1951 and 1975. The mean age at the first I-131 treatment was 56 yr. Six percent developed hypothyroidism within one year of therapy, and 72% within 26 yr. Prior antithyroid medication did not affect the incidence of hypothyroidism. Patients cured with one dose of I-131 had a lower cumulative long-term incidence of hypothyroidism than those requiring more than one dose.

Comparison of high-sensitivity C-reactive protein and fetuin-A levels before and after treatment for subjects with subclinical hyperthyroidism.

PubMed

Bilgir, Oktay; Bilgir, Ferda; Topcuoglu, Tuba; Calan, Mehmet; Calan, Ozlem

2014-03-01

This study was designed to show the effect of propylthiouracil treatment on sCD40L, high-sensitivity C-reactive protein, and fetuin-A levels on subjects with subclinical hyperthyroidism. After checking sCD40L, high-sensitivity C-reactive protein, and fetuin-A levels of 35 patients with subclinical hyperthyroidism, each was given 50 mg tablets of propylthiouracil three times daily. After 3 months, sCD40L, high-sensitivity C-reactive protein, and fetuin-A levels were then compared to the levels before treatment. Although high-sensitivity C-reactive protein and sCD40L levels were normal in the subclinical hyperthyroidism patients compared to the healthy controls, fetuin-A levels were statistically significantly higher (*p = 0.022). After treatment, fetuin-A levels of subclinical hyperthyroidism patients decreased statistically significantly compared to the levels before treatment (**p = 0.026). sCD40L and high-sensitivity C-reactive protein levels did not have a statistically significant difference compared to the control group and post-propylthiouracil treatment. In subclinical hyperthyroidism patients, high fetuin-A levels before propylthiouracil treatment and decreases in these levels after treatment in cases with subclinical hyperthyroidism indicated the possibility of preventing long-term cardiac complications with propylthiouracil treatment.

131I therapy for 345 patients with refractory severe hyperthyroidism: Without antithyroid drug pretreatment.

PubMed

Ding, Yong; Xing, Jialiu; Fang, Yi; Wang, Yong; Zhang, Youren; Long, Yahong

2016-02-01

The aim of this study is to evaluate the safety and long-term results of (131)I therapy alone for patients with refractory severe hyperthyroidism without antithyroid drug pretreatment. From January 2002 to December 2012, 408 patients with refractory severe hyperthyroidism were treated with (131)I alone. Among them, 345 were followed up for 1 to 10 years for physical examination, thyroid function, and thyroid ultrasound. Complete Blood Count (CBC) liver function, electrocardiogram, echocardiogram, and Emission Computed Tomography (ECT) thyroid imaging were performed as indicated. The 345 patients had concomitant conditions including thyrotoxic heart disease, severe liver dysfunction, enlarged thyroid weighing 80 to 400 g, severe cytopenia, and vasculitis. One to two weeks prior to (131)I therapy, all patients were given low-iodine diet. The dose of (131)I therapy was 2.59 to 6.66 MBq (70 to180 µCi) per gram of thyroid with an average of 3.83 ± 0.6 MBq (103.6 ± 16.4 µCi); and the total (131)I activity administrated for the individuals was 111 to 3507.6 MBq (3.0 to 94.8 mCi, mean 444 ± 336.7 MBq (12.0 ± 9.1 mCi)). Out of the 408 patients, 283 were cured, 15 with complete remission, and 47 with incomplete remission. No treatment failure or significant clinical worsening was noted in these patients. Our data indicated that (131)I therapy alone for patients with refractory severe hyperthyroidism without antithyroid drug pretreatment is safe and effective. © 2015 by the Society for Experimental Biology and Medicine.

[Management of hypothyroidism and hyperthyroidism].

PubMed

Jiskra, Jan

2015-10-01

Functional thyropathies present significant health risks for patients. Advanced functional thyropathies are always treated while indications for therapy of subclinical thyropathies are individual and often controversial. It is widely agreed that these disorders should be diagnosed and individuals should be followed. The drug of choice in substitution therapy of hypothyroidism is levothyroxine, in the treatment of hyperthyroidism it is methimazole. Administration of propylthiouracil should be limited to the first trimester of pregnancy, because its serious hepatotoxicity has been described. Hyperthyroidism based on thyroid nodules and immunogenic hyperthyroidism not reaching long-term remission, need to be treated radically: by surgery or radioiodine treatment. When radiation protection requirements are met, radioiodine can also be administered on an outpatient basis. Exceptionally, small doses of methimazole can be administered over an extended period of time in individual cases.

Cancer Incidence and Mortality in Patients Treated Either With RAI or Thyroidectomy for Hyperthyroidism.

PubMed

Ryödi, Essi; Metso, Saara; Jaatinen, Pia; Huhtala, Heini; Saaristo, Rauni; Välimäki, Matti; Auvinen, Anssi

2015-10-01

Some previous studies have suggested increased cancer risk in hyperthyroid patients treated with radioactive iodine (RAI). It is unclear whether the excess cancer risk is attributable to hyperthyroidism, its treatment, or the shared risk factors of the two diseases. The objective was to assess cancer morbidity and mortality in hyperthyroid patients treated with either RAI or surgery. We identified 4334 patients treated surgically for hyperthyroidism in Finland during 1986-2007 from the Hospital Discharge Registry and 1814 patients treated with RAI for hyperthyroidism at Tampere University Hospital. For each patient, three age- and gender-matched controls were chosen. Information on cancer diagnoses was obtained from the Cancer Registry. The follow-up began 3 months after the treatment and ended at cancer diagnosis, death, emigration, or the common closing date (December 31, 2009). The overall cancer incidence was not increased among the hyperthyroid patients compared to their controls (rate ratio [RR], 1.05; 95% confidence interval [CI], 0.96-1.15). However, the risk of cancers of the respiratory tract (RR, 1.46; 95% CI, 1.05-2.02) and the stomach (RR, 1.64; 95% CI, 1.01-2.68) was increased among the patients. The overall cancer mortality did not differ between the patients and the controls (RR, 1.08; 95% CI, 0.94-1.25). The type of treatment did not affect the overall risk of cancer (hazard ratio for RAI vs thyroidectomy, 1.03; 95% CI, 0.86-1.23) or cancer mortality (hazard ratio, 1.04; 95% CI, 0.91-1.21). In this cohort of Finnish patients with hyperthyroidism treated with thyroidectomy or RAI, the overall risk of cancer was not increased, although an increased risk of gastric and respiratory tract cancers was seen in hyperthyroid patients. Based on this large-scale, long-term follow-up study, the increased cancer risk in hyperthyroid patients is attributable to hyperthyroidism and shared risk factors, not the treatment modality.

Subclinical hyperthyroidism and cardiovascular risk: recommendations for treatment.

PubMed

Palmeiro, Christopher; Davila, Maria I; Bhat, Mallika; Frishman, William H; Weiss, Irene A

2013-01-01

Subclinical hyperthyroidism (SHy), the mildest form of hyperthyroidism, is diagnosed in patients having a persistently low or undetectable serum concentration of thyroid-stimulating hormone (TSH) with normal free T4 and T3 concentrations. Although overt hyperthyroidism is associated with an increased risk of adverse cardiovascular outcomes, the cardiovascular risk of SHy is controversial. Multiple studies have demonstrated an increased risk of atrial fibrillation, especially in older individuals with TSH levels <0.1 mU/L. The effects of SHy on all-cause and cardiovascular mortality are not clear, but recent meta-analyses suggest a modest increase in mortality, with the risk increasing with age and associated with the lowest TSH levels. The long-term consequences of SHy in young- and middle-aged adults, and in those with TSH levels are mildly low, are uncertain. For these reasons, guidelines for treatment are based on patient age, the degree of TSH suppression, symptoms consistent with hyperthyroidism, and overall cardiovascular and osteoporotic fracture risks.

Subclinical hyperthyroidism: possible danger of overzealous thyroxine replacement therapy.

PubMed

Ross, D S

1988-12-01

Many patients taking customary doses of levothyroxine have slightly elevated serum thyroxine (T4), apparently normal serum triiodothyronine, suppressed serum thyrotropin (thyroid-stimulating hormone; TSH) concentrations, and no clinical symptoms of hyperthyroidism. Recent reports suggest that these patients may have adverse effects from subclinical hyperthyroidism, including abnormally short systolic time intervals, elevations in liver enzymes, and reductions in bone density. Controversy exists about which thyroid function tests should be used to monitor patients taking levothyroxine. A review of currently available data suggests that replacement doses of levothyroxine given to hypothyroid patients should be adjusted so that serum TSH measured by the new sensitive assays is within the normal range. Patients requiring suppressive doses of levothyroxine to shrink goitrous thyroid tissue or to prevent growth of abnormal tissue should be given the minimal dose needed to accomplish the desired clinical or biochemical response.

The impact of carvedilol and metoprolol on serum lipid concentrations and symptoms in patients with hyperthyroidism.

PubMed

Ozbilen, Sabahattin; Eren, Mehmet Ali; Turan, Mehmet Nuri; Sabuncu, Tevfik

2012-01-01

Hyperthyroidism is associated with unpleasant symptoms and hypertension due to increased adrenergic tone. Therefore, beta-blockers are often used in hyperthyroid patients. While some beta-blockers (such as propronolol and metoprolol) may have unwanted effects on lipid profile, carvedilol, a new alpha- and beta-blocker, has been suggested to have some metabolic advantages with respect to lipid profiles in hypertensive patients. However, this has not been shown in hyperthyroid patients. We aimed to compare the effects of two beta-blockers (metoprolol and carvedilol) on the lipid profiles of hyperthyroid patients with hypertension. Thirty patients with hyperthyroidism and hypertension were randomly assigned to receive either carvedilol (n = 15) or metoprolol (n = 15). Thyroid-stimulating hormone (TSH), free T3, free T4, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride, and total cholesterol levels were measured before and following 3 months of treatment. Systolic and diastolic blood pressure, heart rate, TSH, and free T4 improved significantly in both treatment groups. There were no statistically significant changes in the lipid parameters in either of the two treatment groups; however, triglyceride levels slightly decreased with carvedilol treatment. There were also no differences between the two groups in terms of the typical symptoms of hyperthyroidism. Carvedilol might be a preferred agent to treat hyperthyroid patients who have hypertension and dyslipidemia. This is likely due to the possible beneficial effect of carvedilol on lipid parameters, especially on triglyceride levels.

Is herbal therapy safe in obesity? A case of Apium graveolens (Celery) induced hyperthyroidism.

PubMed

Rouhi-Boroujeni, Hojjat; Hosseini, Masih; Gharipour, Mojgan; Rouhi-Boroujeni, Hamid

2016-09-01

Apium graveolens is one of the well-known herbs used for the treatment of different; however, allergic reactions have been reported after its use. This report aimed to demonstrate the A. graveolens induced hyperthyroidism after its oral consumption for weight loss. Mr. A, 48-year-old, with no history of any thyroid diseases, was diagnosed with hyperthyroidism due to daily consumption of 4 g of dried celery leaves for 45 days. After cessation of consumption and treatment with methimazole, the symptoms remitted. Then, the medication was discontinued when the lab tests and ultrasound were normal and indicated the patient's definite recovery. In 2 months follow up of, he was normal and thyroid-stimulating hormone (TSH), T4, T3, anti-TSH receptor, anti thyroperoxidase and antithyroglobulin were in normal ranges. Hyperthyroidism may be induced by consumption celery. Although many studies have reported side effects such as allergic reactions for this herb, this is the first report of hyperthyroidism induced by celery in which the patient recovered after discontinuing the medication. Therefore, it can be assumed that celery induces hyperthyroidism as a side effect of this herb if it is used for a long term.

Effect of hypo- and hyperthyroidism on hexokinase in the developing cerebellum of the rat.

PubMed

Gutekunst, D I; Wilson, J E

1981-05-01

Total hexokinase levels (units/g tissue) have been measured during postnatal development of the cerebellum in control, hypothyroid, and hyperthyroid rats. In addition. distribution of hexokinase in the developing cerebellum has been observed with an immunofluorescence method. Hypothyroidism delays the normally observed postnatal increase in total hexokinase activity, whereas hyperthyroidism accelerates the increase. In normal animals, hexokinase levels in maturing Purkinje cells pass through a transient increase, with maximal levels at approximately 8 days postnatally followed by rapid decline to relatively low levels by 12 days; hypothyroidism delays this transient increase and subsequent decline, but hyperthyroidism does not appear to affect markedly the timing of this phenomenon. Cerebellar glomeruli are relatively enriched in hexokinase content, as judged by their intense fluorescence. Hypothyroidism delays the development of intensely stained glomeruli. Hyperthyroidism did not appear to cause precocious increase in numbers of glomeruli but may have increased the rate at which the hexokinase was assimilated by newly formed glomeruli. The effects of hypo- and hyperthyroidism on total cerebellar hexokinase levels are interpreted in terms of the effect of thyroid hormone on the biochemical maturation of synaptic structures rich in hexokinase.

Effect of hyper- and hypothyroidism on the alpha-tocopherol concentration in serum and some organs of growing rats.

PubMed

Hrubá, F; Neradilová, M; Nováková, V; Blahosová, I

1976-01-01

The finding of a raised alpha-tocopherol concentration in the heart muscle, liver, skeletal muscle and serum during experimental hyperthyroidism, lasting 30 days, made the authors assume that this cumulation is a transient phenomenon which would disappear during a prolonged metabolic disorder as a result of energetic breakdown of the organism. The purpose of the paper was to verify this view. The investigation with experimental hyper- and hypothyroidism was made in 120 rats with a mean weight of 160 g. To 60 animals daily 100 mug thyroxin were administered by the i.p. route, 48 animals were given 2.5 Carbimazol daily by mouth to induce hypothyroidism and 12 animals served as controls. The animals were fed the same diet. The effect of the administered preparations was examined after 20, 30, 40, 50 and 60 days. In hypothyroid animals the 50th day was omitted. The results revealed: 1. In hyperthyroid animals the body weight was almost constant to the end of the experiment. However these animals had a significantly raised weight of the heart muscle and liver, as compared with the remaining two groups. 2. In hyperthyroid animals the highest alpha-tocopherol concentration in the heart muscle and skeletal muscle was recorded after 20 days. During subsequent time intervals the alpha-tocopherol concentration in the heart muscle declined gradually. In the skeletal muscle a dramatic decline occurred after 40 days and proceeded to the end of the investigation when the recorded values were at the borderline of detectability. This finding confirmed the authors view that the alpha-tocopherol cumulation in muscle exposed to an increased work load is a transient phenomenon and disappears during prolonged hyperthyroidism before the breakdown of the organism. 3. In hyperthyroidism no correlation was found between the alpha-tocopherol concentration and the lipid content of organs and skeletal muscle. This correlation was found in hypothyroidism. 4. The alpha-tocopherol serum level in hyperthyroidism was significantly higher than in hypothyroidism. 5. In hyperthyroidism the alpha-tocopherol cumulation in liver increased gradually, and reached its maximum after 50 days. At a time when the alpha-tocopherol concentration in the heart muscle and skeletal muscle declined already, its liver concentration increased. This phenomenon may be associated with the increasing protein synthesis in the liver during hyperthyroidism, or with other phenomena which call for further investigation.

Quality-of-Life Impairments Persist Six Months After Treatment of Graves' Hyperthyroidism and Toxic Nodular Goiter: A Prospective Cohort Study.

PubMed

Cramon, Per; Winther, Kristian Hillert; Watt, Torquil; Bonnema, Steen Joop; Bjorner, Jakob Bue; Ekholm, Ola; Groenvold, Mogens; Hegedüs, Laszlo; Feldt-Rasmussen, Ulla; Rasmussen, Åse Krogh

2016-08-01

The treatment of hyperthyroidism is aimed at improving health-related quality of life (HRQoL) and reducing morbidity and mortality. However, few studies have used validated questionnaires to assess HRQoL prospectively in such patients. The purpose of this study was to assess the impact of hyperthyroidism and its treatment on HRQoL using validated disease-specific and generic questionnaires. This prospective cohort study enrolled 88 patients with Graves' hyperthyroidism and 68 with toxic nodular goiter from endocrine outpatient clinics at two Danish university hospitals. The patients were treated with antithyroid drugs, radioactive iodine, or surgery. Disease-specific and generic HRQoL were assessed using the thyroid-related patient-reported outcome (ThyPRO) and the Medical Outcomes Study 36-item Short Form (SF-36), respectively, evaluated at baseline and six-month follow-up. The scores were compared with those from two general population samples who completed ThyPRO (n = 739) and SF-36 (n = 6638). Baseline scores for patients with Graves' hyperthyroidism and toxic nodular goiter were significantly worse than those for the general population scores on all comparable ThyPRO scales and all SF-36 scales and component summaries. ThyPRO scores improved significantly with treatment on all scales in Graves' hyperthyroidism and four scales in toxic nodular goiter, while SF-36 scores improved on five scales and both component summaries in Graves' hyperthyroidism and only one scale in toxic nodular goiter. In Graves' hyperthyroidism, large treatment effects were observed on three ThyPRO scales (Hyperthyroid Symptoms, Tiredness, Overall HRQoL) and moderate effects on three scales (Anxiety, Emotional Susceptibility, Impaired Daily Life), while moderate effects were seen in two ThyPRO scales in toxic nodular goiter (Anxiety, Overall HRQoL). However, significant disease-specific and generic HRQoL deficits persisted on multiple domains across both patient groups. Graves' hyperthyroidism and toxic nodular goiter cause severe disease-specific and generic HRQoL impairments, and HRQoL deficits persist in both patient groups six months after treatment. These data have the potential to improve communication between physicians and patients by offering realistic estimates of expected HRQoL impairments and treatment effects. Future studies should identify risk factors for persistent HRQoL deficits, compare HRQoL effects of the various therapies, and thereby aid in determining the optimal treatment strategies.

Effect of arginine on the GHRH-stimulated GH secretion in patients with hyperthyroidism.

PubMed

Giustina, A; Schettino, M; Bussi, A R; Legati, F; Licini, M; Zuccato, F; Wehrenberg, W B

1992-01-01

Patients with hyperthyroidism have reduced GH responses to pharmacological stimuli and reduced spontaneous nocturnal GH secretion. The stimulatory effect of arginine on GH secretion has been suggested to depend on a decrease in hypothalamic somatostatin tone. The aim of our study was to evaluate the effects of arginine on the GH-releasing hormone (GHRH)-stimulated GH secretion in patients with hyperthyroidism. Six hyperthyroid patients with recent diagnosis of Graves' disease [mean age +/- SEM, 39.2 +/- 1.4 years; body mass index (BMI) 22 +/- 0.4 kg/m2] and 6 healthy nonobese volunteers (4 males, 2 females; mean age +/- SEM, 35 +/- 3.5 years) underwent two experimental trials at no less than 7-day intervals: GHRH (100 micrograms, i.v.)-induced GH secretion was evaluated after 30 min i.v. infusion of saline (100 ml) or arginine (30 g) in 100 ml of saline. Hyperthyroid patients showed blunted GH peaks after GHRH (13.2 +/- 2.9 micrograms/l) as compared with normal subjects (23.8 +/- 3.9 micrograms/l, p < 0.05). GH peaks after GHRH were only slightly enhanced by arginine in hyperthyroid subjects (17.6 +/- 2.9 micrograms/l), whereas, in normal subjects, the enhancement was clear cut (36.6 +/- 4.4 micrograms/l; p < 0.05). GH values after arginine + GHRH were still lower in hyperthyroid patients with respect to normal subjects. Our data demonstrate that arginine enhances but does not normalize the GH response to GHRH in patients with hyperthyroidism when compared with normal subjects. We hypothesize that hyperthyroxinemia may decrease GH secretion, both increasing somatostatin tone and acting directly at the pituitary level.

Linear Analysis of Autonomic Activity and Its Correlation with Creatine Kinase-MB in Overt Thyroid Dysfunctions.

PubMed

Mavai, Manisha; Singh, Yogendra Raj; Gupta, R C; Mathur, Sandeep K; Bhandari, Bharti

2018-04-01

Autonomic activity may be deranged in thyroid dysfunctions and may lead to cardiovascular morbidity and mortality. Myopathy is a common manifestation in thyroid disorders and may be associated with raised serum creatine kinase (CK). We hypothesized that cardiovascular abnormality in thyroid dysfunction may manifest as raised CK-MB. This study was designed to investigate the correlation of CK and its isoform CK-MB with thyroid profile and linear parameters of heart rate variability (HRV). The study was conducted on 35 hypothyroid and hyperthyroid patients each, and 25 age-matched healthy controls. Autonomic activity was assessed by simple short term 5-min HRV. Biochemical evaluation of serum thyroid profile, CK-NAC and CK-MB were estimated in all the subjects. Our results demonstrated low HRV in hypo- as well as hyperthyroid patients. We observed significantly higher serum CK levels in hypothyroid patients when compared to hyperthyroids and controls. However, no significant differences were observed in CK-MB levels in the three groups. Significant positive correlation of CK with TSH and negative correlation with some HRV parameters (LF power, HF power, total power, SDNN, RMSSD) was observed in hypothyroid patients. Whereas correlation of CK-MB with thyroid profile as well as HRV parameters was non-significant in all the groups. Based on the CK and CK-MB findings and their correlation, we conclude that the cardiovascular changes seen in thyroid dysfunctions may primarily be due to autonomic imbalance without apparent cardiac muscle involvement. Whereas, raised CK levels indicate predominantly skeletal muscle involvement in hypothyroid patients.

Altered regulation of energy homeostasis in older rats in response to thyroid hormone administration

PubMed Central

Walrand, Stephane; Short, Kevin R.; Heemstra, Lydia A.; Novak, Colleen M.; Levine, James A.; Coenen-Schimke, Jill M.; Nair, K. Sreekumaran

2014-01-01

Hyperthyroidism causes increased energy intake and expenditure, although anorexia and higher weight loss have been reported in elderly individuals with hyperthyroidism. To determine the effect of age on energy homeostasis in response to experimental hyperthyroidism, we administered 200 μg tri-iodothyronine (T3) in 7- and 27-mo-old rats for 14 d. T3 increased energy expenditure (EE) in both the young and the old rats, although the old rats lost more weight (147 g) than the young rats (58 g) because of the discordant effect of T3 on food intake, with a 40% increase in the young rats, but a 40% decrease in the old ones. The increased food intake in the young rats corresponded with a T3-mediated increase in the appetite-regulating proteins agouti-related peptide, neuropeptide Y, and uncoupling protein 2 in the hypothalamus, but no increase occurred in the old rats. Evidence of mitochondrial biogenesis in response to T3 was similar in the soleus muscle and heart of the young and old animals, but less consistent in old plantaris muscle and liver. Despite the comparable increase in EE, T3's effect on mitochondrial function was modulated by age in a tissue-specific manner. We conclude that older rats lack compensatory mechanisms to increase caloric intake in response to a T3-induced increase in EE, demonstrating a detrimental effect of age on energy homeostasis.—Walrand, S., Short, K. R., Heemstra, L. A., Novak, C. M., Levine, J. A., Coenen-Schimke, J. M., Nair, K. S. Altered regulation of energy homeostasis in older rats in response to thyroid hormone administration. PMID:24344330

Hyperthyroidism.

PubMed

Maji, D

2006-10-01

Hyperthyroidism is a clinical situation where there is excess thyroid hormones in the circulation due to increased synthesis of hormone from a hyperactive thyroid gland. Common causes are Graves' disease, toxic multinodular goitre and toxic solitary nodule. Excess thyroid hormones in the circulation are also found in thyroiditis (hormone leakage) and excess exogenous thyroxine intake. Thyrotoxicosis is the term applied when there is excess thyroid hormone in the circulation due to any cause. Thyrotoxicosis can be easily diagnosed by high serum level of thyroxine (T4) and triiodothyronine (T3) and low serum level of thyroid stimulating hormone (TSH). Hyperthyroidism is confirmed by high isotope (I 131 or Tc99) uptake by the thyroid gland, while in thyroiditis it will be low. Treatment of hyperthyroidism depends on the underlying cause. Antithyroid drugs, 1131 therapy and surgery are the options of treatment of hyperthyroidism. Surgery is the preferred treatment for toxic adenoma and toxic multinodular goitre, while 1131 therapy may be suitable in some cases. Antithyroid drugs and 1131 therapy are mostly preferred for Graves' disease. Beta-adrenergic blockers are used for symptomatic relief in most patients of thyrotoxicosis due to any cause. Other rare causes of hyperthyroidism like, amiodarone induced thyrotoxicosis, choriocarcinoma, thyrotropin secreting pituitary tumour are difficult to diagnose as well as to treat.

Improved endothelial function and lipid profile compensate for impaired hemostatic and inflammatory status in iatrogenic chronic subclinical hyperthyroidism of thyroid cancer patients on L-t4 therapy.

PubMed

Gazdag, A; Nagy, E V; Burman, K D; Paragh, G; Jenei, Z

2010-06-01

We aimed to compare the changes of endothelial function and haemostatic, inflammatory and metabolic parameters of short-term iatrogenic hypothyroidism to the characteristics of subclinical hyperthyroidism in patients with differentiated thyroid cancer. Twenty four women (mean age 42.4+/-8.1 years) had undergone total thyroidectomy and radioiodine ablation in treatment for differentiated thyroid cancer. We measured serum thyroglobulin, thyroid function, plasma levels of lipid parameters, homocystine, C-reactive protein, fibrinogen, von Willebrandt factor activity (vWF), nitric oxide, as well as flow-mediated vasodilatation (FMD) and nitroglycerin-mediated vasodilatation of the brachial artery during iatrogenic hypothyroidism (TSH 89.82+/-29.36 mU/L) and again in the same patients during subclinical hyperthyroidism secondary to exogenous levothyroxine administration (TSH 0.24+/-0.11 mU/L). In hypothyroidism, FMD was markedly lower than in subclinical hyperthyroidism (6.79+/-4.44 vs. 14.37+/-8.33%, p<0.005). Total cholesterol (7.34+/-1.23 vs. 4.75+/-1.14 mmol/L, p<0.001), LDL-cholesterol (4.55+/-1.10 vs. 2.70+/-0.89 mmol/L, p<0.005) and homocystine (12.95+/-4.49 vs. 9.62+/-2.29 micromol/L, p<0.005) were significantly higher in hypothyroidism. There was no difference in nitroglycerin-mediated vasodilatation, blood pressure, serum triglyceride and HDL-cholesterol levels according to thyroid function. Fibrinogen (3.23+/-0.50 vs. 4.01+/-0.84 g/L, p<0.005), vWF (90.09+/-25.92 vs.130.63+/-29.97%, p<0.001), C-reactive protein (4.39+/-5.16 vs. 5.55+/-5.15 mg/L, p<0.001) and plasma nitric oxide (24.56+/-6.71 vs. 32.34+/-7.0 micromol/L, <0.005) values were significantly lower in hypothyroidism. FMD correlated in a positive manner with fibrinogen, vWF and nitrogen oxide. Chronic subclinical hyperthyroidism was associated with improved endothelial function and lipid profile, while haemostatic and inflammatory parameters were impaired. The two opposite mechanisms may well compensate for each other at the level of the vessel wall. (c) J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart, New York.

Long-term associative learning predicts verbal short-term memory performance.

PubMed

Jones, Gary; Macken, Bill

2018-02-01

Studies using tests such as digit span and nonword repetition have implicated short-term memory across a range of developmental domains. Such tests ostensibly assess specialized processes for the short-term manipulation and maintenance of information that are often argued to enable long-term learning. However, there is considerable evidence for an influence of long-term linguistic learning on performance in short-term memory tasks that brings into question the role of a specialized short-term memory system separate from long-term knowledge. Using natural language corpora, we show experimentally and computationally that performance on three widely used measures of short-term memory (digit span, nonword repetition, and sentence recall) can be predicted from simple associative learning operating on the linguistic environment to which a typical child may have been exposed. The findings support the broad view that short-term verbal memory performance reflects the application of long-term language knowledge to the experimental setting.

Hyperthyroidism

PubMed Central

2016-01-01

Hyperthyroidism is characterised by increased thyroid hormone synthesis and secretion from the thyroid gland, whereas thyrotoxicosis refers to the clinical syndrome of excess circulating thyroid hormones, irrespective of the source. The most common cause of hyperthyroidism is Graves’ disease, followed by toxic nodular goitre. Other important causes of thyrotoxicosis include thyroiditis, iodine-induced and drug-induced thyroid dysfunction, and factitious ingestion of excess thyroid hormones. Treatment options for Graves’ disease include antithyroid drugs, radioactive iodine therapy, and surgery, whereas antithyroid drugs are not generally used long term in toxic nodular goitre, because of the high relapse rate of thyrotoxicosis after discontinuation. β blockers are used in symptomatic thyrotoxicosis, and might be the only treatment needed for thyrotoxicosis not caused by excessive production and release of the thyroid hormones. Thyroid storm and hyperthyroidism in pregnancy and during the post-partum period are special circumstances that need careful assessment and treatment. PMID:27038492

Management of hyper and hypo thyroid conditions

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

Locke, W.

1982-03-01

In hyperthyroidism, the primary objective of therapy is to reduce secretion of thyroid hormone, which can be accomplished in various ways. The stimulus to hypersecretion can be removed in some causes of hyperthyroidism; in others, hormone synthesis and release can be inhibited by drugs such as thioamides, adrenergic blocking agents, or possibly lithium or glucocorticoids. Radioactive iodine is indicated for primary therapy of uncomplicated hyperthyroidism due to Graves' disease in persons over 30 years of age (myxedema may be a complication) and for treatment of autonomous thyroid adenoma in patients who are not suitable candidates for surgery. Surgical ablation ismore » preferred for some causes of hyperthyroidism but may induce postoperative hypothyroidism. Hypothyroidism due to thyroid failure usually presents few therapeutic difficulties and can be managed simply by long-term hormone replacement. Before hormone replacement is prescribed for secondary or tertiary hypothyroidism, the other pituitary functions should be assessed.« less

Hyperthyroidism.

PubMed

De Leo, Simone; Lee, Sun Y; Braverman, Lewis E

2016-08-27

Hyperthyroidism is characterised by increased thyroid hormone synthesis and secretion from the thyroid gland, whereas thyrotoxicosis refers to the clinical syndrome of excess circulating thyroid hormones, irrespective of the source. The most common cause of hyperthyroidism is Graves' disease, followed by toxic nodular goitre. Other important causes of thyrotoxicosis include thyroiditis, iodine-induced and drug-induced thyroid dysfunction, and factitious ingestion of excess thyroid hormones. Treatment options for Graves' disease include antithyroid drugs, radioactive iodine therapy, and surgery, whereas antithyroid drugs are not generally used long term in toxic nodular goitre, because of the high relapse rate of thyrotoxicosis after discontinuation. β blockers are used in symptomatic thyrotoxicosis, and might be the only treatment needed for thyrotoxicosis not caused by excessive production and release of the thyroid hormones. Thyroid storm and hyperthyroidism in pregnancy and during the post-partum period are special circumstances that need careful assessment and treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

The role of AT1-receptor blockade on reactive oxygen species and cardiac autonomic drive in experimental hyperthyroidism.

PubMed

Baraldi, D; Casali, K; Fernandes, R O; Campos, C; Sartório, C; Conzatti, A; Couto, G K; Schenkel, P C; Belló-Klein, A; Araujo, A R S

2013-10-01

The objective of this study was to explore the influence of the renin-angiotensin system on cardiac prooxidants and antioxidants levels and its association to autonomic imbalance induced by hyperthyroidism. Male Wistar rats were divided into four groups: control, losartan (10mg/kg/day by gavage, 28 day), thyroxine (T4) (12 mg/L in drinking water for 28 days), and T4+losartan. Spectral analysis (autonomic balance), angiotensin II receptor (AT1R), NADPH oxidase, Nrf2 and heme-oxygenase-1 (HO-1) myocardial protein expression, and hydrogen peroxide (H2O2) concentration were quantified. Autonomic imbalance induced by hyperthyroidism (~770%) was attenuated in the T4+losartan group (~32%) (P<0.05). AT1R, NADPH oxidase, H2O2, as well as concentration, Nrf2 and HO-1 protein expression were elevated (~172%, 43%, 40%, 133%, and 154%, respectively) in T4 group (P<0.05). H2O2 and HO-1 levels were returned to control values in the T4+losartan group (P<0.05). The overall results demonstrate a positive impact of RAS blockade in the autonomic control of heart rate, which was associated with an attenuation of H2O2 levels, as well as with a reduced counter-regulatory response of HO-1 in experimental hyperthyroidism. Copyright © 2013 Elsevier B.V. All rights reserved.

B cell-targeted therapy with anti-CD20 monoclonal antibody in a mouse model of Graves' hyperthyroidism.

PubMed

Ueki, I; Abiru, N; Kobayashi, M; Nakahara, M; Ichikawa, T; Eguchi, K; Nagayama, Y

2011-03-01

Graves' disease is a B cell-mediated and T cell-dependent autoimmune disease of the thyroid which is characterized by overproduction of thyroid hormones and thyroid enlargement by agonistic anti-thyrotrophin receptor (TSHR) autoantibody. In addition to antibody secretion, B cells have recently been recognized to function as antigen-presenting/immune-modulatory cells. The present study was designed to evaluate the efficacy of B cell depletion by anti-mouse (m) CD20 monoclonal antibody (mAb) on Graves' hyperthyroidism in a mouse model involving repeated injection of adenovirus expressing TSHR A-subunit (Ad-TSHR289). We observe that a single injection of 250 µg/mouse anti-mCD20 mAb eliminated B cells efficiently from the periphery and spleen and to a lesser extent from the peritoneum for more than 3 weeks. B cell depletion before immunization suppressed an increase in serum immunoglobulin (Ig)G levels, TSHR-specific splenocyte secretion of interferon (IFN)-γ, anti-TSHR antibody production and development of hyperthyroidism. B cell depletion 2 weeks after the first immunization, a time-point at which T cells were primed but antibody production was not observed, was still effective at inhibiting antibody production and disease development without inhibiting splenocyte secretion of IFN-γ. By contrast, B cell depletion in hyperthyroid mice was therapeutically ineffective. Together, these data demonstrate that B cells are critical not only as antibody-producing cells but also as antigen-presenting/immune-modulatory cells in the early phase of the induction of experimental Graves' hyperthyroidism and, although therapeutically less effective, B cell depletion is highly efficient for preventing disease development. © 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.

Patients with chronic hepatitis type C and interferon-alpha-induced hyperthyroidism in two-years clinical follow-up.

PubMed

Czarnywojtek, Agata; Zgorzalewicz-Stachowiak, Magorzata; Wasko, Ryszard; Czepczynski, Rafal; Szczepanek-Parulska, Ewelina; Waligorska-Stachura, Joanna; Kurdybacha, Peter; Bereszynska, Iwona; Florek, Ewa; Stangierski, Adam; Zdanowska, Joanna; Nikisch, Elżbieta; Sowinski, Jerzy; Ruchala, Marek

2013-01-01

Interferon-α (IFN-α) is a gold standard in the therapy of viral chronic hepatitis type C (CHC). However, such treatment might lead to thyroid dysfunction. Patients usually present hypothyroidism, but rarely also hyperthyroidism may develop. The aim of the study is to present two-year clinical follow-up of patients with CHC and IFN-α-induced hyperthyroidism (IIH), with special regard to the methods and efficacy of the therapy. A group of 106 patients with CHC and IIH were analyzed. Subjects were divided into two groups according to etiology: group 1, with Graves' disease (GD) and group 2, with Hashitoxicosis (HT). The diagnosis of GD and HT was based on: clinical signs of hyperthyroidism, hormonal profile (TSH, fT4, fT3), level of thyroid autoantibodies (Tg-Abs, TPO-Abs, TSHRAbs). Treatment of hyperthyroidism was monitored by repeated clinical assessment and laboratory tests. RESULST: 28 patients (26 with GD of which 5 exhibited mild orbitopathy and 2 with HT) were treated with radioiodine [the average dose of was 17 mCi [668 MBq]. In adition 78 out of 80 patients with HT mostly β-blocker therapy was successful (transient hyperthyroidism). At the end of the observation period, in group 1 remission was achieved in 17 (65.4%) cases, 6 (23.1%) patients showed hypothyroidism and 3 (11.5%) presented recurrence of hyperthyroidism. Most patients with IIH present Hashitoxicosis, while a minority of them develop Graves' disease. In a majority of patients with HT spontaneous remission of disease occurs. In patients with long-term hyperthyroidism, radioiodine therapy is an effective and well-tolerated.

Benefit of Anticoagulation Therapy in Hyperthyroidism-Related Atrial Fibrillation.

PubMed

Chan, Pak-Hei; Hai, Jojo; Yeung, Chun-Yip; Lip, Gregory Y H; Lam, Karen Siu-Ling; Tse, Hung-Fat; Siu, Chung-Wah

2015-08-01

Existing data on the risk of ischemic stroke in hyperthyroidism-related atrial fibrillation (AF) and the impact of long-term anticoagulation in these patients, particularly those with self-limiting AF, remain inconclusive. Risk of stroke in hyperthyroidism-related AF is the same as nonhyperthyroid counterparts. This was a single-center observational study of 9727 Chinese patients with nonvalvular AF from July 1997 to December 2011. Patients with AF diagnosed concomitantly with hyperthyroidism were identified. Primary and secondary endpoints were defined as hospitalization with ischemic stroke and intracranial hemorrhage in the first 2 years. Patient characteristics, duration of AF, and choice of antithrombotic therapy were recorded. Self-limiting AF was defined as <7 days' duration. Out of 9727 patients, 642 (6.6%) had concomitant hyperthyroidism and AF at diagnosis. For stroke prevention, 136 and 243 patients (21.1% and 37.9%) were prescribed warfarin and aspirin, respectively, whereas the remaining patients (41.0%) received no therapy. Ischemic stroke occurred in 50 patients (7.8%), and no patient developed hemorrhagic stroke. Patients with CHA2 DS2 -VASc of 0 did not develop stroke. Warfarin effectively reduced the incidence of stroke compared with aspirin or no therapy in patients with CHA2 DS2 -VASc ≥1 and non-self-limiting AF, but not in those with self-limiting AF or CHA2 DS2 -VASc of 0. Presence of hyperthyroidism did not confer additional risk of ischemic stroke compared with nonhyperthyroid AF. Patients with hyperthyroidism-related AF are at high risk of stroke (3.9% per year). Warfarin confers stroke prevention in patients with CHA2 DS2 -VASc ≥1 and non-self-limiting AF. Overall stroke risk was lower in hyperthyroid non-self-limiting AF patients compared with nonhyperthyroid counterparts. © 2015 Wiley Periodicals, Inc.

Acute cardiovascular events and all-cause mortality in patients with hyperthyroidism: a population-based cohort study.

PubMed

Dekkers, Olaf M; Horváth-Puhó, Erzsébet; Cannegieter, Suzanne C; Vandenbroucke, Jan P; Sørensen, Henrik Toft; Jørgensen, Jens Otto L

2017-01-01

Several studies have shown an increased risk for cardiovascular disease (CVD) in hyperthyroidism, but most studies have been too small to address the effect of hyperthyroidism on individual cardiovascular endpoints. Our main aim was to assess the association among hyperthyroidism, acute cardiovascular events and mortality. It is a nationwide population-based cohort study. Data were obtained from the Danish Civil Registration System and the Danish National Patient Registry, which covers all Danish hospitals. We compared the rate of all-cause mortality as well as venous thromboembolism (VTE), acute myocardial infarction (AMI), ischemic and non-ischemic stroke, arterial embolism, atrial fibrillation (AF) and percutaneous coronary intervention (PCI) in the two cohorts. Hazard ratios (HR) with 95% confidence intervals (95% CI) were estimated. The study included 85 856 hyperthyroid patients and 847 057 matched population-based controls. Mean follow-up time was 9.2 years. The HR for mortality was highest in the first 3 months after diagnosis of hyperthyroidism: 4.62, 95% CI: 4.40-4.85, and remained elevated during long-term follow-up (>3 years) (HR: 1.35, 95% CI: 1.33-1.37). The risk for all examined cardiovascular events was increased, with the highest risk in the first 3 months after hyperthyroidism diagnosis. The 3-month post-diagnosis risk was highest for atrial fibrillation (HR: 7.32, 95% CI: 6.58-8.14) and arterial embolism (HR: 6.08, 95% CI: 4.30-8.61), but the risks of VTE, AMI, ischemic and non-ischemic stroke and PCI were increased also 2- to 3-fold. We found an increased risk for all-cause mortality and acute cardiovascular events in patients with hyperthyroidism. © 2017 European Society of Endocrinology.

Clinical outcomes after estimated versus calculated activity of radioiodine for the treatment of hyperthyroidism: systematic review and meta-analysis.

PubMed

de Rooij, A; Vandenbroucke, J P; Smit, J W A; Stokkel, M P M; Dekkers, O M

2009-11-01

Despite the long experience with radioiodine for hyperthyroidism, controversy remains regarding the optimal method to determine the activity that is required to achieve long-term euthyroidism. To compare the effect of estimated versus calculated activity of radioiodine in hyperthyroidism. Design Systematic review and meta-analysis. We searched the databases Medline, EMBASE, Web of Science, and Cochrane Library for randomized and nonrandomized studies, comparing the effect of activity estimation methods with dosimetry for hyperthyroidism. The main outcome measure was the frequency of treatment success, defined as persistent euthyroidism after radioiodine treatment at the end of follow-up in the dose estimated and calculated dosimetry group. Furthermore, we assessed the cure rates of hyperthyroidism. Three randomized and five nonrandomized studies, comparing the effect of estimated versus calculated activity of radioiodine on clinical outcomes for the treatment of hyperthyroidism, were included. The weighted mean relative frequency of successful treatment outcome (euthyroidism) was 1.03 (95% confidence interval (CI) 0.91-1.16) for estimated versus calculated activity; the weighted mean relative frequency of cure of hyperthyroidism (eu- or hypothyroidism) was 1.03 (95% CI 0.96-1.10). Subgroup analysis showed a relative frequency of euthyroidism of 1.03 (95% CI 0.84-1.26) for Graves' disease and of 1.05 (95% CI 0.91-1.19) for toxic multinodular goiter. The two main methods used to determine the activity in the treatment of hyperthyroidism with radioiodine, estimated and calculated, resulted in an equally successful treatment outcome. However, the heterogeneity of the included studies is a strong limitation that prevents a definitive conclusion from this meta-analysis.

Opposing Effects of Maternal Hypo- and Hyperthyroidism on the Stability of Thalamocortical Synapses in the Visual Cortex of Adult Offspring.

PubMed

Strobl, Marie-Therese J; Freeman, Daniel; Patel, Jenica; Poulsen, Ryan; Wendler, Christopher C; Rivkees, Scott A; Coleman, Jason E

2017-05-01

Insufficient or excessive thyroid hormone (TH) levels during fetal development can cause long-term neurological and cognitive problems. Studies in animal models of perinatal hypo- and hyperthyroidism suggest that these problems may be a consequence of the formation of maladaptive circuitry in the cerebral cortex, which can persist into adulthood. Here we used mouse models of maternal hypo- and hyperthyroidism to investigate the long-term effects of altering thyroxine (T4) levels during pregnancy (corresponding to embryonic days 6.5-18.5) on thalamocortical (TC) axon dynamics in adult offspring. Because perinatal hypothyroidism has been linked to visual processing deficits in humans, we performed chronic two-photon imaging of TC axons and boutons in primary visual cortex (V1). We found that a decrease or increase in maternal serum T4 levels was associated with atypical steady-state dynamics of TC axons and boutons in V1 of adult offspring. Hypothyroid offspring exhibited axonal branch and bouton dynamics indicative of an abnormal increase in TC connectivity, whereas changes in hyperthyroid offspring were indicative of an abnormal decrease in TC connectivity. Collectively, our data suggest that alterations to prenatal T4 levels can cause long-term synaptic instability in TC circuits, which could impair early stages of visual processing. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Prevalence of Hyperthyroidism Following Exposure During Childhood or Adolescence to Radioiodines from the Chornobyl Nuclear Accident: Dose-Response Results from the Ukrainian-American Cohort Study

PubMed Central

Hatch, M.; Furukawa, K.; Brenner, A.; Olinjyk, V.; Ron, E.; Zablotska, L.; Terekhova, G.; McConnell, R.; Markov, V.; Shpak, V.; Ostroumova, E.; Bouville, A.; Tronko, M.

2013-01-01

Relatively few data are available on the prevalence of hyperthyroidism (TSH concentrations of < 0.3 mIU/L, with normal or elevated concentrations of free T4) in individuals exposed to radioiodines at low levels. The accident at the Chornobyl (Chernobyl) nuclear plant in Ukraine on April 26, 1986 exposed large numbers of residents to radioactive fallout, principally to iodine-131 (I-131) (mean and median doses = 0.6 Gray (Gy) and 0.2 Gy). We investigated the relationship of I-131 and prevalent hyperthyroidism among 11,853 individuals exposed as children or adolescents in Ukraine who underwent an in-depth, standardized thyroid gland screening examination 12–14 years later. Radioactivity measurements taken shortly after the accident were available for all subjects and were used to estimate individual thyroid doses. We identified 76 cases of hyperthyroidism (11 overt, 65 subclinical). Using logistic regression, we tested a variety of continuous risk models and conducted categorical analyses for all subjects combined and for females (53 cases, n=5,767) and males (23 cases, n=6,086) separately, but found no convincing evidence of a dose response relationship between I-131 and hyperthyroidism. There was some suggestion of elevated risk among females in an analysis based on a dichotomous dose model with a threshold of 0.5 Gy chosen empirically (OR=1.86, P=0.06), but the statistical significance level was reduced (P=0.13) in a formal analysis with an estimated threshold. In summary, after a thorough exploration of the data, we found no statistically significant dose response relationship between individual I-131 thyroid doses and prevalent hyperthyroidism. PMID:21128800

Prediction of long-term transverse creep compliance in high-temperature IM7/LaRC-RP46 composites

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

Yuan, F.G.; Potter, B.D.

1994-12-31

An experimental study is performed which predicts long-term tensile transverse creep compliance of high-temperature IM7/LaRC-RP46 composites from short-term creep and recovery tests. The short-term tests were conducted for various stress levels at various fixed temperatures. Predictive nonlinear viscoelastic model developed by Schapery and experimental procedure were used to predict the long-term results in terms of master curve extrapolated from short-term tests.

Neonatal Outcomes and Birth Weight in Pregnancies Complicated by Maternal Thyroid Disease

PubMed Central

Männistö, Tuija; Mendola, Pauline; Reddy, Uma; Laughon, S. Katherine

2013-01-01

Maternal hypothyroidism has previously been shown to increase risk for neonatal intensive care treatment, but otherwise the association between thyroid diseases and neonatal morbidity is understudied. The Consortium on Safe Labor, a retrospective cohort (2002–2008), included 223,512 singleton deliveries of which 0.2% had hyperthyroidism, 1.4% primary and 0.1% iatrogenic hypothyroidism, and 1.3% other/unspecified thyroid disease. Logistic regression with generalized estimating equations estimated adjusted odds ratios of adverse outcomes. Intensive care treatment was more common for neonates of women with thyroid disease. Hyperthyroidism and primary hypothyroidism were associated with sepsis, respiratory distress syndrome, transient tachypnea, and apnea. Iatrogenic hypothyroidism was associated with sepsis and neonatal anemia. Hyperthyroidism was also associated with rare outcomes (prevalence, <1%) including cardiomyopathy, retinopathy of prematurity, and neonatal thyroid diseases. Hyperthyroid non-Hispanic black women had higher odds of term infants that weighed <2,500 g, and hypothyroid non-Hispanic white women had higher odds of large-for-gestational-age infants. These analyses were stratified by race/ethnicity due to interaction. Associations were similar in analyses restricted to term infants. In conclusion, thyroid diseases were associated with increased neonatal morbidity. Although we lacked data on treatment during pregnancy, these nationwide data suggest a need for better thyroid disease management to reduce neonatal morbidity. PMID:23666815

Acute effects of clonidine and growth-hormone-releasing hormone on growth hormone secretion in patients with hyperthyroidism.

PubMed

Giustina, A; Buffoli, M G; Bussi, A R; Wehrenberg, W B

1991-01-01

Patients with hyperthyroidism have reduced growth hormone (GH) responses to pharmacological stimuli and reduced spontaneous nocturnal GH secretion. The stimulatory effect of clonidine on GH secretion has been suggested to depend on an enhancement of hypothalamic GH-releasing hormone (GHRH) release. The aim of our study was to evaluate the effects of clonidine and GHRH on GH secretion in patients with hyperthyroidism. Eight hyperthyroid females with recent diagnosis of Graves' disease (age range 20-55 years, body mass index range 19.2-26.2 kg/m2) and 6 healthy female volunteers (age range 22-35 years, body mass index range 19-25 kg/m2) underwent two experimental trials at no less than 7-day intervals: (a) an intravenous infusion of clonidine 150 micrograms in 10 ml of saline, or (b) a bolus intravenous injection of human GHRH (1-29)NH2, 100 micrograms in 1 ml of saline. Hyperthyroid patients showed blunted GH peaks after clonidine (7.1 +/- 1.7 micrograms/l) as compared to normal subjects receiving clonidine (28.5 +/- 4.9 micrograms/l, p less than 0.05). GH peaks after GHRH were also significantly lower in hyperthyroid subjects (8.0 +/- 1.7 micrograms/l) as compared to normal subjects receiving GHRH (27.5 +/- 4.4 micrograms/l, p less than 0.05). No significant differences in the GH values either after clonidine or GHRH were observed in the two groups of subjects examined. Our data demonstrate that the GH responses to clonidine as well as to GHRH in patients with hyperthyroidism are inhibited in a similar fashion with respect to normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Managing hyperthyroidism in pregnancy: current perspectives

PubMed Central

Andersen, Stine Linding; Laurberg, Peter

2016-01-01

Hyperthyroidism in women who are of childbearing age is predominantly of autoimmune origin and caused by Graves’ disease. The physiological changes in the maternal immune system during a pregnancy may influence the development of this and other autoimmune diseases. Furthermore, pregnancy-associated physiological changes influence the synthesis and metabolism of thyroid hormones and challenge the interpretation of thyroid function tests in pregnancy. Thyroid hormones are crucial regulators of early development and play an important role in the maintenance of a normal pregnancy and in the development of the fetus, particularly the fetal brain. Untreated or inadequately treated hyperthyroidism is associated with pregnancy complications and may even program the fetus to long-term development of disease. Thus, hyperthyroidism in pregnant women should be carefully managed and controlled, and proper management involves different medical specialties. The treatment of choice in pregnancy is antithyroid drugs (ATDs). These drugs are effective in the control of maternal hyperthyroidism, but they all cross the placenta, and so need careful management and control during the second half of pregnancy considering the risk of fetal hyper- or hypothyroidism. An important aspect in the early pregnancy is that the predominant side effect to the use of ATDs in weeks 6–10 of pregnancy is birth defects that may develop after exposure to available types of ATDs and may be severe. This review focuses on four current perspectives in the management of overt hyperthyroidism in pregnancy, including the etiology and incidence of the disease, how the diagnosis is made, the consequences of untreated or inadequately treated disease, and finally how to treat overt hyperthyroidism in pregnancy. PMID:27698567

Managing hyperthyroidism in pregnancy: current perspectives.

PubMed

Andersen, Stine Linding; Laurberg, Peter

2016-01-01

Hyperthyroidism in women who are of childbearing age is predominantly of autoimmune origin and caused by Graves' disease. The physiological changes in the maternal immune system during a pregnancy may influence the development of this and other autoimmune diseases. Furthermore, pregnancy-associated physiological changes influence the synthesis and metabolism of thyroid hormones and challenge the interpretation of thyroid function tests in pregnancy. Thyroid hormones are crucial regulators of early development and play an important role in the maintenance of a normal pregnancy and in the development of the fetus, particularly the fetal brain. Untreated or inadequately treated hyperthyroidism is associated with pregnancy complications and may even program the fetus to long-term development of disease. Thus, hyperthyroidism in pregnant women should be carefully managed and controlled, and proper management involves different medical specialties. The treatment of choice in pregnancy is antithyroid drugs (ATDs). These drugs are effective in the control of maternal hyperthyroidism, but they all cross the placenta, and so need careful management and control during the second half of pregnancy considering the risk of fetal hyper- or hypothyroidism. An important aspect in the early pregnancy is that the predominant side effect to the use of ATDs in weeks 6-10 of pregnancy is birth defects that may develop after exposure to available types of ATDs and may be severe. This review focuses on four current perspectives in the management of overt hyperthyroidism in pregnancy, including the etiology and incidence of the disease, how the diagnosis is made, the consequences of untreated or inadequately treated disease, and finally how to treat overt hyperthyroidism in pregnancy.

Hyperthyroidism increases the uncoupled ATPase activity and heat production by the sarcoplasmic reticulum Ca2+-ATPase.

PubMed

Arruda, Ana Paula; Da-Silva, Wagner S; Carvalho, Denise P; De Meis, Leopoldo

2003-11-01

The sarcoplasmic reticulum Ca2+-ATPase is able to modulate the distribution of energy released during ATP hydrolysis, so that a portion of energy is used for Ca2+ transport (coupled ATPase activity) and a portion is converted into heat (uncoupled ATPase activity). In this report it is shown that T4 administration to rabbits promotes an increase in the rates of both the uncoupled ATPase activity and heat production in sarcoplasmic reticulum vesicles, and that the degree of activation varies depending on the muscle type used. In white muscles hyperthyroidism promotes a 0.8-fold increase of the uncoupled ATPase activity and in red muscle a 4-fold increase. The yield of vesicles from hyperthyroid muscles is 3-4-fold larger than that obtained from normal muscles; thus the rate of heat production by the Ca2+-ATPase expressed in terms of g of muscle in hyperthyroidism is increased by a factor of 3.6 in white muscles and 12.0 in red muscles. The data presented suggest that the Ca2+-ATPase uncoupled activity may represent one of the heat sources that contributes to the enhanced thermogenesis noted in hyperthyroidism.

Oxidative muscular injury and its relevance to hyperthyroidism.

PubMed

Asayama, K; Kato, K

1990-01-01

In experimental hyperthyroidism, acceleration of lipid peroxidation occurs in heart and slow-oxidative muscles, suggesting the contribution of reactive oxygen species to the muscular injury caused by thyroid hormones. This article reviews various models of oxidative muscular injury and considers the relevance of the accompanying metabolic derangements to thyrotoxic myopathy and cardiomyopathy, which are the major complications of hyperthyroidism. The muscular injury models in which reactive oxygen species are supposed to play a role are ischemia/reperfusion syndrome, exercise-induced myopathy, heart and skeletal muscle diseases related to the nutritional deficiency of selenium and vitamin E and related disorders, and genetic muscular dystrophies. These models provide evidence that mitochondrial function and the glutathione-dependent antioxidant system are important for the maintenance of the structural and functional integrity of muscular tissues. Thyroid hormones have a profound effect on mitochondrial oxidative activity, synthesis and degradation of proteins and vitamin E, the sensitivity of the tissues to catecholamine, the differentiation of muscle fibers, and the levels of antioxidant enzymes. The large volume of circumstantial evidence presented here indicates that hyperthyroid muscular tissues undergo several biochemical changes that predispose them to free radical-mediated injury.

[Pathogenesis and management of Grave's ophthalmopathy].

PubMed

Wierzbowska, Joanna; Stankiewicz, Andrzej

2002-01-01

The most recent hypothesis on pathogenesis of Graves' Ophthalmopathy (GO) and short characteristics of the disease was presented. Emphasis was placed on the necessity of coordinated treatment of the thyroid dysfunction and ophthalmopathy. Management of hyperthyroidism and Graves' ophthalmopathy, including the latest methods was described.

Estimation of gastric ghrelin-positive cells activity in hyperthyroid rats.

PubMed

Dadan, Jacek; Zbucki, Robert L; Sawicki, Bogusław; Winnicka, Maria M

2008-01-01

Ghrelin is a peptide of 28 amino acids that transmits appetite related signals from peripheral organs to the brain. The main source of ghrelin is stomach. The regulation of ghrelin secretion is still unknown. The finding that fasting and food intake, respectively increase and decrease the secretion of ghrelin suggests that this hormone may be a bridge connecting somatic growth with energy metabolism and appears to play an important role in the alteration of energy homeostasis and body weight in pathophisiological conditions. The purpose of this study was the evaluation of gastric ghrelin immunoreactivity and ghrelin plasma concentration in male Wistar rats with hyperthyroidism. Experimental model of hyperthyroidism was induced by intraperitoneal injection of levothyroxine at the dose of 80 microg/kg daily over 21 days. At the end of experiment the animals were anaesthetized, blood was taken from abdominal aorta to determinate plasma ghrelin concentration by RIA and then the animals underwent resection of distal part of stomach. Immunohistochemical study were performed using monoclonal specific antybodies against ghrelin. Hyperthyroidism was a reason of increase of gastric mucosal ghrelin - immunoreactivity, accompanied by a significant decreased of ghrelin plasma concentration. Those observations may indicate, that chronic administration of L-thyroxine cause the change of ghrelin plasma concentration in rats, probably via direct influence on gastric X/A-like cells, but this effect is not responsible for hyperphagia associated with hyperthyroidism.

The prevalence of thyroid cancer in patients with hyperthyroidism

PubMed Central

Kunjumohamed, Fathimabeebi P.; Al-Busaidi, Noor B.; Al-Musalhi, Hilal N.; Al-Shereiqi, Sulaiman Z.; Al-Salmi, Issa S.

2015-01-01

Objectives: To determine the prevalence of thyroid cancer in patients with hyperthyroidism. Methods: This is a retrospective observational study using the data of 71 Omani patients with a diagnosis of hyperthyroidism due to Grave’s disease, toxic multinodular goiter, and solitary toxic adenoma. These patients underwent thyroidectomy at the Royal Hospital (RH), Muscat, Oman, and were followed up at the National Diabetes and Endocrine Center (NDEC) between 2007 and 2013. The details were collected from the medical records of both the RH and the NDEC. Patients who underwent thyroidectomy for other reasons like non-toxic goiter and hypothyroidism with cancer were excluded from the study. Results: Thyroid cancer was identified in 32.8% (n=23) of patients with hyperthyroidism. Half of these patients 52.1% (n=12) had papillary micro-cancer (intra-thyroidal), and 3 patients with Grave’s disease (13%) had lymph nodes metastasis (loco-regional infiltration. The cancer preponderance was higher in young (n=21, 91.3%) and female patients (n=18, 73.9%). Most patients with thyroid cancer had abnormal ultrasound neck findings and thyroid scintigraphy (99 mTc uptake). Conclusion: Many patients with hyperthyroidism in Muscat, Oman, especially those with Grave’s disease, show malignancy, and hence a proper initial evaluation of these patients is required as part of long-term management. PMID:26108596

The prevalence of thyroid cancer in patients with hyperthyroidism.

PubMed

Kunjumohamed, Fathimabeebi P; Al-Busaidi, Noor B; Al-Musalhi, Hilal N; Al-Shereiqi, Sulaiman Z; Al-Salmi, Issa S

2015-07-01

To determine the prevalence of thyroid cancer in patients with hyperthyroidism. This is a retrospective observational study using the data of 71 Omani patients with a diagnosis of hyperthyroidism due to Grave's disease, toxic multinodular goiter, and solitary toxic adenoma. These patients underwent thyroidectomy at the Royal Hospital (RH), Muscat, Oman, and were followed up at the National Diabetes and Endocrine Center (NDEC) between 2007 and 2013. The details were collected from the medical records of both the RH and the NDEC. Patients who underwent thyroidectomy for other reasons like non-toxic goiter and hypothyroidism with cancer were excluded from the study. Thyroid cancer was identified in 32.8% (n=23) of patients with hyperthyroidism. Half of these patients 52.1% (n=12) had papillary micro-cancer (intra-thyroidal), and 3 patients with Grave's disease (13%) had lymph nodes metastasis (loco-regional infiltration. The cancer preponderance was higher in young (n=21, 91.3%) and female patients (n=18, 73.9%). Most patients with thyroid cancer had abnormal ultrasound neck findings and thyroid scintigraphy (99 mTc uptake). Many patients with hyperthyroidism in Muscat, Oman, especially those with Grave's disease, show malignancy, and hence a proper initial evaluation of these patients is required as part of long-term management.

RhoA/ROCK may involve in cardiac hypertrophy induced by experimental hyperthyroidism.

PubMed

Na, Wang; Peng, Guan; Jianping, Zhang; Yanzhong, Chang; Shengjiang, Guan; Li, Chu

2012-10-01

In this study, the role of the RhoA/Rho-kinase (RhoA/ROCK)-signaling pathway in cardiovascular dysfunction associated with hyperthyroidism was examined with the use of fasudil, a Rho-kinase inhibitor. Male Spraque-Dawley rats were treated with l-thyroxine (T(4)) alone, T(4) + low-dose fasudil (2 mg/kg/day) or T(4) + high-dose fasudil (10 mg/kg/day) and compared with control animals. Rats in the T(4) group showed an increase in the ratio of heart weight to body weight, which was ameliorated by fasudil at both low and high doses. Morphometric and hemodynamic parameters were also evaluated and confirmed that fasudil attenuated the cardiac hypertrophy induced by T(4). The extent of phosphorylation of the myosin phosphatase targeting subunit was quantified by Western blotting to evaluate the activity of Rho-kinase in the heart tissue. Both Western blotting and reverse transcriptase-polymerase chain reaction analyses revealed enhancement of Rho-kinase and activator protein 1 activity and reduction of c-FLIP(L) expression in the T(4) group, and this response was inhibited by fasudil in a dose-dependent manner. Furthermore, fasudil inhibited apoptosis induced by T(4) as evidenced by the detection of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells and the expressions of bax and bcl-2. These results suggested that the RhoA/ROCK pathway is involved in the cardiac hypertrophy induced by experimental hyperthyroidism. The antagonism of this pathway may thus be useful as an alternative target in the treatment of hyperthyroid heart disease.

Autonomic contribution to the blood pressure and heart rate variability changes in early experimental hyperthyroidism.

PubMed

Safa-Tisseront, V; Ponchon, P; Laude, D; Elghozi, J L

1998-12-01

To study the interaction between autonomic nervous activity and thyroid hormones in the control of heart rate (HR) and blood pressure (BP). Thyrotoxicosis was produced by injections of L-thyroxine (0.5 mg/kg/day for five days). Blockers were atropine (0.5 mg/kg), atenolol (1 mg/kg) or prazosin (1 mg/kg). Eight animals were studied in each group. Spectral analyses was performed using continuous BP time series obtained in conscious rats. Thyroxine treatment was sufficient to induce a significant degree of tachycardia (423+/-6 vs 353+/-4 bpm, P < 0.001, unpaired Student's t test), systolic BP elevation (142+/-3 vs 127+/-2 mmHg, P < 0.001) and cardiac hypertrophy (1.165+/-0.017 vs 1.006+/-0.012 g, P < 0.001). The intrinsic HR was markedly increased after treatment with thyroxine (497+/-16 vs 373+/-10 bpm, P < 0.05). Vagal tone was positively linearly related to intrinsic HR (r = 0.84, P< 0.01). Atenolol neither modified HR nor BP variability in rats with hyperthyroidism. The thyrotoxicosis was associated with a reduction of the 0.4 Hz component of BP variability (modulus 1.10+/-0.07 vs 1.41+/-0.06 mmHg, P < 0.01). Prazosin was without effect on this 0.4 Hz component in hyperthyroid animals. These data show a functional diminution of the vascular and cardiac sympathetic tone in early experimental hyperthyroidism. The marked rise in the intrinsic HR could be the main determinant of tachycardia. The BP elevation may reflexly induce vagal activation and sympathetic (vascular and cardiac) inhibition.

Vascular and renal function in experimental thyroid disorders.

PubMed

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

2006-02-01

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

Phospholipid composition of oligodendroglial cells during normal development and in 18 day old hyperthyroid and malnourished rats.

PubMed

Kreda, S M; Pasquini, J M; Soto, E F

1992-09-01

The phospholipid composition of isolated oligodendroglial cell perikarya was studied in normal rats during development and in 18 day old malnourished and hyperthyroid rats. Phosphatidyl choline and phosphatidyl ethanolamine were found to be the major phospholipid constituents of oligodendroglial cells. Phospholipid content increased during development, mainly due to an increase of the above mentioned phospholipids. The major changes were observed in sphingomyelin, phosphatidyl serine, phosphatidyl inositol and phosphatidyl ethanolamine between 18 and 30 days of age. The phospholipid and protein content per cell was significantly decreased in the oligodendroglial cells isolated from malnourished rats as compared to controls. When data were expressed as a function of total proteins, the composition was similar to that of normal animals. In the hyperthyroid rats on the other hand, there were no changes in the amount of phospholipids per cell, while phospholipids per milligram of total oligodendroglial cell protein were markedly decreased. The changes in myelin composition produced by hyperthyroidism that we have previously described, do not follow closely those produced by this experimental condition in oligodendroglial cells, suggesting that the metabolism of myelin might be to a certain extent, independent of that in the parent cell.

[Impact of thyroid diseases on bone].

PubMed

Tsourdi, E; Lademann, F; Siggelkow, H

2018-05-09

Thyroid hormones are key regulators of skeletal development in childhood and bone homeostasis in adulthood, and thyroid diseases have been associated with increased osteoporotic fractures. Hypothyroidism in children leads to an impaired skeletal maturation and mineralization, but an adequate and timely substitution with thyroid hormones stimulates bone growth. Conversely, hyperthyroidism at a young age accelerates skeletal development, but may also cause short stature because of a premature fusion of the growth plates. Hypothyroidism in adults causes an increase in the duration of the remodeling cycle and, thus, leads to low bone turnover and enhanced mineralization, but an association with a higher fracture risk is less well established. In adults, a surplus of thyroid hormones enhances bone turnover, mostly due to an increased bone resorption driven by osteoclasts. Thus, hyperthyroidism is a well-recognized cause of high-bone turnover secondary osteoporosis, resulting in an increased susceptibility to fragility fractures. Subclinical hyperthyroidism, especially resulting from endogenous disease, also has an adverse effect on bone mineral density and is associated with fractures. In most patients with overt or subclinical hyperthyroidism restoration of the euthyroid status reverses bone loss. In postmenopausal women who receive thyroid-stimulating hormone suppression therapy because of thyroid cancer, antiresorptive treatments may be indicated. Overall, extensive data support the importance of a euthyroid status for bone mineral accrual and growth in childhood as well as maintenance of bone health in adulthood.

Management of Subclinical Hyperthyroidism

PubMed Central

Santos Palacios, Silvia; Pascual-Corrales, Eider; Galofre, Juan Carlos

2012-01-01

The ideal approach for adequate management of subclinical hyperthyroidism (low levels of thyroid-stimulating hormone [TSH] and normal thyroid hormone level) is a matter of intense debate among endocrinologists. The prevalence of low serum TSH levels ranges between 0.5% in children and 15% in the elderly population. Mild subclinical hyperthyroidism is more common than severe subclinical hyperthyroidism. Transient suppression of TSH secretion may occur because of several reasons; thus, corroboration of results from different assessments is essential in such cases. During differential diagnosis of hyperthyroidism, pituitary or hypothalamic disease, euthyroid sick syndrome, and drug-mediated suppression of TSH must be ruled out. A low plasma TSH value is also typically seen in the first trimester of gestation. Factitial or iatrogenic TSH inhibition caused by excessive intake of levothyroxine should be excluded by checking the patient’s medication history. If these nonthyroidal causes are ruled out during differential diagnosis, either transient or long-term endogenous thyroid hormone excess, usually caused by Graves’ disease or nodular goiter, should be considered as the cause of low circulating TSH levels. We recommend the following 6-step process for the assessment and treatment of this common hormonal disorder: 1) confirmation, 2) evaluation of severity, 3) investigation of the cause, 4) assessment of potential complications, 5) evaluation of the necessity of treatment, and 6) if necessary, selection of the most appropriate treatment. In conclusion, management of subclinical hyperthyroidism merits careful monitoring through regular assessment of thyroid function. Treatment is mandatory in older patients (> 65 years) or in presence of comorbidities (such as osteoporosis and atrial fibrillation). PMID:23843809

Atypical Clinical Manifestations of Graves' Disease: An Analysis in Depth

PubMed Central

Hegazi, Mohamed Osama; Ahmed, Sherif

2012-01-01

Over the past few decades, there has been an increase in the number of reports about newly recognized (atypical or unusual) manifestations of Graves' disease (GD), that are related to various body systems. One of these manifestations is sometimes the main presenting feature of GD. Some of the atypical manifestations are specifically related to GD, while others are also similarly seen in patients with other forms of hyperthyroidism. Lack of knowledge of the association between these findings and GD may lead to delay in diagnosis, misdiagnosis, or unnecessary investigations. The atypical clinical presentations of GD include anemia, vomiting, jaundice, and right heart failure. There is one type of anemia that is not explained by any of the known etiological factors and responds well to hyperthyroidism treatment. This type of anemia resembles anemia of chronic disease and may be termed GD anemia. Other forms of anemia that are associated with GD include pernicious anemia, iron deficiency anemia of celiac disease, and autoimmune hemolytic anemia. Vomiting has been reported as a presenting feature of Graves' disease. Some cases had the typical findings of hyperthyroidism initially masked, and the vomiting did not improve until hyperthyroidism has been detected and treated. Hyperthyroidism may present with jaundice, and on the other hand, deep jaundice may develop with the onset of overt hyperthyroidism in previously compensated chronic liver disease patients. Pulmonary hypertension is reported to be associated with GD and to respond to its treatment. GD-related pulmonary hypertension may be so severe to produce isolated right-sided heart failure that is occasionally found as the presenting manifestation of GD. PMID:22132347

Outcome of very long-term treatment with antithyroid drugs in Graves' hyperthyroidism associated with Graves' orbitopathy.

PubMed

Elbers, Laura; Mourits, Maarten; Wiersinga, Wilmar

2011-03-01

It is still debated which treatment modality for Graves' hyperthyroidism (GH) is most appropriate when Graves' orbitopathy (GO) is present. The preference in our center has been always to continue antithyroid drugs for GH (as the block-and-replace [B-R] regimen) until all medical and/or surgical treatments for GO are concluded and the eye disease does not require any further therapy (except prescription of lubricants). This usually takes more than 2 years. The aim of this study was to evaluate the outcome of long-term B-R regimen for GH in GO patients by assessment (after discontinuation of B-R) of (a) the recurrence rate of GH and (b) the relapse rate of GO and its association with recurrent GH and/or (131)I therapy. A retrospective follow-up study was done among all patients referred to the Academic Medical Center in Amsterdam between 1995 and 2005 for GO. The inclusion criteria for the study were a history of GH and GO and a history of treatment for GH with a B-R regimen for more than 2 years. The exclusion criteria were a history of (131)I therapy or thyroidectomy before the end of GO treatment. A questionnaire was sent to 255 patients and returned by 114. Of these patients, 73 qualified for the study. Recurrences of GH and/or GO as indicated by returned questionnaires were checked with treating physicians. Patients were treated with B-R for a median of 41 months (range: 24-132). The median follow-up after discontinuation of the B-R regimen was 57 months (range: 12-170). Recurrent GH occurred in 27 of the 73 study patients (37%) at a median of 3 months (range: 1-65) after withdrawal of antithyroid drug therapy. Nineteen of the 27 patients with recurrent hyperthyroidism were treated with (131)I therapy. A relapse of GO was not encountered in any of the 73 patients. The study suggests that long-term B-R treatment of GH in GO patients is associated with a recurrence rate of hyperthyroidism of about 37%. With the regimen employed, recurrence of hyperthyroidism and recurrence of hyperthyroidism followed by treatment with (131)I appears not to be a likely cause of relapse of GO. The data suggest that B-R treatment of GH until GO has become inactive and does not require any further treatment is a feasible option and does not jeopardize the improvement that occurred in GO.

Preclinical models of Graves' disease and associated secondary complications.

PubMed

Moshkelgosha, Sajad; So, Po-Wah; Diaz-Cano, Salvador; Banga, J Paul

2015-01-01

Autoimmune thyroid disease is the most common organ-specific autoimmune disorder which consists of two opposing clinical syndromes, Hashimoto's thyroiditis and Graves' (hyperthyroidism) disease. Graves' disease is characterized by goiter, hyperthyroidism, and the orbital complication known as Graves' orbitopathy (GO), or thyroid eye disease. The hyperthyroidism in Graves' disease is caused by stimulation of function of thyrotropin hormone receptor (TSHR), resulting from the production of agonist antibodies to the receptor. A variety of induced mouse models of Graves' disease have been developed over the past two decades, with some reproducible models leading to high disease incidence of autoimmune hyperthyroidism. However, none of the models show any signs of the orbital manifestation of GO. We have recently developed an experimental mouse model of GO induced by immunization of the plasmid encoded ligand binding domain of human TSHR cDNA by close field electroporation that recapitulates the orbital pathology in GO. As in human GO patients, immune mice with hyperthyroid or hypothyroid disease induced by anti-TSHR antibodies exhibited orbital pathology and chemosis, characterized by inflammation of orbital muscles and extensive adipogenesis leading to expansion of the orbital retrobulbar space. Magnetic resonance imaging of the head region in immune mice showed a significant expansion of the orbital space, concurrent with proptosis. This review discusses the different strategies for developing mouse models in Graves' disease, with a particular focus on GO. Furthermore, it outlines how this new model will facilitate molecular investigations into pathophysiology of the orbital disease and evaluation of new therapeutic interventions.

Differential effects of experimental and cold-induced hyperthyroidism on factors inducing rat liver oxidative damage.

PubMed

Venditti, P; Pamplona, R; Ayala, V; De Rosa, R; Caldarone, G; Di Meo, S

2006-03-01

Thyroid hormone-induced increase in metabolic rates is often associated with increased oxidative stress. The aim of the present study was to investigate the contribution of iodothyronines to liver oxidative stress in the functional hyperthyroidism elicited by cold, using as models cold-exposed and 3,5,3'-triiodothyronine (T3)- or thyroxine (T4)-treated rats. The hyperthyroid state was always associated with increases in both oxidative capacity and oxidative damage of the tissue. The most extensive damage to lipids and proteins was found in T3-treated and cold-exposed rats, respectively. Increase in oxygen reactive species released by mitochondria and microsomes was found to contribute to tissue oxidative damage, whereas the determination of single antioxidants did not provide information about the possible contribution of a reduced effectiveness of the antioxidant defence system. Indeed, liver oxidative damage in hyperthyroid rats was scarcely related to levels of the liposoluble antioxidants and activities of antioxidant enzymes. Conversely, other biochemical changes, such as the degree of fatty acid unsaturation and hemoprotein content, appeared to predispose hepatic tissue to oxidative damage associated with oxidative challenge elicited by hyperthyroid state. As a whole, our results confirm the idea that T3 plays a key role in metabolic changes and oxidative damage found in cold liver. However, only data concerning changes in glutathione peroxidase activity and mitochondrial protein content favour the idea that dissimilarities in effects of cold exposure and T3 treatment could depend on differences in serum levels of T4.

[Effects of melaxen and valdoxan on the activity of glutathione antioxidant system and NADPH-producing enzymes in rat heart under experimental hyperthyroidism conditions].

PubMed

Gorbenko, M V; Popova, T N; Shul'gin, K K; Popov, S S

2013-01-01

The effects of melaxen and valdoxan on the activity of glutathione antioxidant system and some NADPH-producing enzymes have been studied under conditions of experimental hyperthyroidism in rat heart. Under the action of these drugs, reduced glutathione (GSH) content increased as compared to values observed under the conditions of pathology. It has been established that the activities of glutathione reductase (GR), glutathione peroxidase (GP), glucose-6-phosphate dehydrogenase, and NADP isocitrate dehydrogenase (increased under pathological conditions) change toward the intact control values upon the introduction of both drugs. The influence of melaxen and valdoxan, capable of producing antioxidant effect, leads apparently to the inhibition of free-radical oxidation processes and, as a consequence, the reduction of mobilization degree of the glutathione antioxidant system.

Experimental hypo/hyperthyroidism in rats and the perinatal development of the hypothalamo-neurohypophysial system in comparison with the thyroid gland state and external features.

PubMed

Kiessig, R; Wolf, G; Dietzmann, K

1983-05-01

Neurophysin was detected immunohistochemically in the hypothalamo-neurohypophysial system of Wistar rats not before fetal day 18. Formerly, neurophysin was identified on day 16 of intrauterine life using another breeding stock of Wistar rats, but the same immunohistochemical reagents. In pregnant rats, experimentally induced hypo/hyperthyroidism beginning with day 13 of gestation failed to show any evident influence on the first appearance of immunohistochemically detectable neurophysin during the fetal development. Otherwise, significant effects on fetal body growth and other external features as well as the fetal thyroid state and histochemically demonstrable thyroid peroxidase activity were shown. The influence of thiamazol on the fetal thyroid peroxidase points out a primary effect and indicates the permeability of the placenta to this antithyroid drug.

[Hyperthyroid and acute tonsillitis in a 23-year-old woman].

PubMed

Beyer, G; Küster, I; Budde, C; Wilhelm, E; Hoene, A; Evert, K; Stracke, S; Friesecke, S; Mayerle, J; Steveling, A

2016-07-01

A 23-year-old woman with preexisting Graves' disease who received thiamazole treatment presented with fever, dysphagia, hyperthyroidism and leukopenia. With suspicion of thyreotoxicosis accompanied by drug-induced agranulocytosis she was successfully managed by plasmapheresis, G‑CSF administration and inhibition of periphereal conversion of thyroid hormones. In due course she underwent thyroidectomy. Thiamazole is frequently associated with drug-induced agranulocytosis. Long-term therapy with thiamazole requires critical evaluation and alternatives should be considered early. Plasmapheresis is an adequate treatment option to achieve normal thyroid hormonal status.

Hyperthyroidism caused by a germline activating mutation of the thyrotropin receptor gene: difficulties in diagnosis and therapy.

PubMed

Bertalan, Rita; Sallai, Agnes; Sólyom, János; Lotz, Gábor; Szabó, István; Kovács, Balázs; Szabó, Eva; Patócs, Attila; Rácz, Károly

2010-03-01

Germline activating mutations of the thyrotropin receptor (TSHR) gene have been considered as the only known cause of sporadic nonautoimmune hyperthyroidism in the pediatric population. Here we describe the long-term follow-up and evaluation of a patient with sporadic nonautoimmune primary hyperthyroidism who was found to have a de novo germline activating mutation of the TSHR gene. The patient was an infant who presented at the age of 10 months in an unconscious state with exsiccation, wet skin, fever, and tachycardia. Nonautoimmune primary hyperthyroidism was diagnosed, and brain magnetic resonance imaging and computed tomography showed also Arnold-Chiari malformation type I. Continuous propylthiouracil treatment resulted in a prolonged clinical cure lasting for 10 years. At the age of 11 years and 5 months the patient underwent subtotal thyroidectomy because of symptoms of trachea compression caused by a progressive multinodular goiter. However, 2 months after surgery, hormonal evaluation indicated recurrent hyperthyroidism and the patient was treated with propylthiouracil during the next 4 years. At the age of 15 years the patient again developed symptoms of trachea compression. Radioiodine treatment resulted in a regression of the recurrent goiter and a permanent cure of hyperthyroidism without relapse during the last 3 years of his follow-up. Sequencing of exon 10 of the TSHR gene showed a de novo heterozygous germline I630L mutation, which has been previously described as activating mutation at somatic level in toxic thyroid nodules. The I630L mutation of the TSHR gene occurs not only at somatic level in toxic thyroid nodules, but also its presence in germline is associated with nonautoimmune primary hyperthyroidism. Our case report demonstrates that in this disorder a continuous growth of the thyroid occurs without any evidence of elevated TSH due to antithyroid drug overdosing. This may justify previous recommendations for early treatment of affected patients with removal of as much thyroid tissue as possible.

Short- and long-term memory contributions to immediate serial recognition: evidence from serial position effects.

PubMed

Purser, Harry; Jarrold, Christopher

2010-04-01

A long-standing body of research supports the existence of separable short- and long-term memory systems, relying on phonological and semantic codes, respectively. The aim of the current study was to measure the contribution of long-term knowledge to short-term memory performance by looking for evidence of phonologically and semantically coded storage within a short-term recognition task, among developmental samples. Each experimental trial presented 4-item lists. In Experiment 1 typically developing children aged 5 to 6 years old showed evidence of phonologically coded storage across all 4 serial positions, but evidence of semantically coded storage at Serial Positions 1 and 2. In a further experiment, a group of individuals with Down syndrome was investigated as a test case that might be expected to use semantic coding to support short-term storage, but these participants showed no evidence of semantically coded storage and evidenced phonologically coded storage only at Serial Position 4, suggesting that individuals with Down syndrome have a verbal short-term memory capacity of 1 item. Our results suggest that previous evidence of semantic effects on "short-term memory performance" does not reflect semantic coding in short-term memory itself, and provide an experimental method for researchers wishing to take a relatively pure measure of verbal short-term memory capacity, in cases where rehearsal is unlikely.

Pathophysiology of intraocular pressure increase and glaucoma prevalence in thyroid eye disease: a mini-review.

PubMed

Haefliger, I O; von Arx, G; Pimentel, A-R

2010-04-01

The aim of this study was to assess the pathophysiological mechanisms leading to intraocular pressure (IOP) increase and to review the prevalence of glaucoma in thyroid eye disease (TED), an autoimmune reaction affecting extra-ocular muscles and intra-orbital content in thyrotoxicosis (Grave's disease, hyperthyroidism). We applied the modified Friedenswald's and Goldmann's equations to explain the mechanisms by which IOP increases in TED and gave a brief review of the literature. In TED, Friedenswald's equation explains the ultra-short term IOP increase observed when eyes deviate from their primary gaze position (eyeball compression by enlarged and infiltrated extra-ocular muscles). Goldmann's equation explains the long-term IOP increase seen in TED (episcleral venous pressure elevation secondary to intraorbital content and pressure increase). Most studies did not find a significant increase in glaucoma prevalence in patients with TED. In TED, glaucoma prevalence does not seem to be significantly increased and, from a pathophysiological standpoint, the long-term IOP increase is essentially due to episcleral venous pressure elevation. Copyright Georg Thieme Verlag KG Stuttgart . New York.

Long-term follow-up in toxic solitary autonomous thyroid nodules treated with radioactive iodine

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

Huysmans, D.A.; Corstens, F.H.; Kloppenborg, P.W.

1991-01-01

The long-term effects of radioiodine treatment on thyroid function in patients with a toxic solitary autonomous thyroid nodule were evaluated. Fifty-two patients received a therapeutic dose of 20 mCi of iodine-131 ({sup 131}I). Duration of follow-up was 10 +/- 4 yr. Follow-up data included a biochemical evaluation of thyroid function. The failure rate (recurrent hyperthyroidism) was 2%. The incidence of hypothyroidism was 6% and was not related to the dose per gram of nodular tissue. Oral administration of 20 mCi of radioiodine is a simple and highly effective method for the treatment of patients with a toxic autonomous thyroid nodule.more » The risk of development of hypothyroidism is low if extranodular uptake of {sup 131}I is prevented. This can be achieved by not treating euthyroid patients, by no longer using injections of exogenous thyroid stimulating hormone in the diagnostic work-up of the patients and by always performing radioiodine imaging shortly before treatment.« less

Sclerostin and bone metabolism markers in hyperthyroidism before treatment and interrelations between them.

PubMed

Sarıtekin, İlker; Açıkgöz, Şerefden; Bayraktaroğlu, Taner; Kuzu, Fatih; Can, Murat; Güven, Berrak; Mungan, Görkem; Büyükuysal, Çağatay; Sarıkaya, Selda

2017-01-01

Sclerostin, which is a glycoprotein produced by osteocytes, reduces the formation of bones by inhibiting the Wnt signal pathway. Thyroid hormones are related with Wnt signal pathway and it has been reported that increased thyroid hormones in hyperthyroidism fasten epiphysis maturation in childhood, and increase the risk of bone fractures by stimulating the bone loss in adults. The aim of this study was to examine the sclerostin serum levels, the relation between sclerostin and thyroid hormones as well as the biochemical markers of the bone metabolism in patients with hyperthyroidism (including multinodular goiter and Graves' disease), whose treatments have not started yet. No difference was found in the serum sclerostin levels between the hyperthyroidism group (n=24) and the control group (n=24) (p=0.452). The serum osteocalcin levels and 24-hour urinary phosphorus excretion were found to be higher in the hyperthyroid group than in the control group (p<0.001, p=0.009). A positive correlation was determined between the sclerostin and bone alkaline phosphatase levels (p<0.001); a negative correlation between the osteocalcin and thyroid stimulating hormone (TSH) (p<0.05); a positive correlation between the osteocalcin and thyroid hormones (FT 3 ,FT 4 ) (p<0.001); and a positive correlation between the deoxypyridinoline and hydroxyproline (p<0.001). No correlation was determined between sclerostin and TSH,FT 3 ,FT 4 (p>0.05). Therefore, we consider that a long-term study that covers the pre-post treatment stages of hyperthyroidism, including both the destruction and construction of the skeleton would be more enlightening. Moreover, the assessment of the synthesis of sclerostin in the bone tissue and in the serum level might show differences.

MOK, a pharmacopuncture medicine, regulates thyroid dysfunction in L-thyroxin-induced hyperthyroidism in rats through the regulation of oxidation and the TRPV1 ion channel.

PubMed

Hwang, Ji Hye; Kang, Seok Yong; Kang, An Na; Jung, Hyo Won; Jung, Chul; Jeong, Jin-Ho; Park, Yong-Ki

2017-12-15

In this study, we evaluated the therapeutic effect of MOK, a pharmacopuncture medicine, on thyroid dysfunction in L-thyroxin (LT4)-induced hyperthyroidism rats. The experimental hyperthyroidism model was prepared by the intraperitoneal injection of LT4 (0.5 mg/kg) once daily for 2 weeks in SD rats. MOK extract was injected at doses of 0.3 or 3 mg/kg on acupuncture points in the thyroid glands of LT4-induced hypothyroidism rats once a day for 2 weeks. The body temperature, body weight, and food/water intake were measured once a week for 2 weeks. The levels of thyroid hormones, total cholesterol, LDL-cholesterol, GOT, and GPT were measured in the sera of rats using ELISA and an automatic blood analyzer. The histological changes of thyroid tissues were observed by H&E staining. The expression of thermo-regulating protein, TRPV1 was determined by western blot in dorsal root ganglion (DRG) and brain tissues. We also measured the contents of GSH in the liver and antioxidant enzymes, SOD, and catalase in the liver, heart, and brain tissues by enzyme-based assay and Western blot, respectively. The acupuncture of MOK extract on the thyroid gland of LT4-induced hyperthyroidism rats significantly decreased the body temperature, and did not change body weight and food and water intakes. MOK acupuncture significantly increased the level of TSH, and decreased the levels of T3 and T4 in hyperthyroidism rats. The expression of TRPV1 was inhibited in both DRG and brain tissues after MOK acupuncture, and the levels of GOT, GPT, total cholesterol, and LDL-cholesterol were also decreased. MOK acupuncture also inhibited the pathological feature with follicular lining epithelial thicknesses and increased follicular colloid depositions in the thyroid glands of hypothyroidism. MOK acupuncture significantly increased hepatic GSH levels and decreased the expression of SOD and catalase in the liver, heart, and brain tissues of hyperthyroidism rats. These results suggest that the pharmacopuncture with MOK extract in hyperthyroidism can improve the pathophysiological changes through regulating the body temperature, thyroid hormones imbalance, lipid accumulation, and oxidation. This anti-hyperthyroidism effect of MOK pharmacopuncture is thought to be related to the control of thermo-regulating protein TRPV1 in DRG and brain.

Contribution of the autonomic nervous system to blood pressure and heart rate variability changes in early experimental hyperthyroidism.

PubMed

Safa-Tisseront, V; Ponchon, P; Laude, D; Elghozi, J L

1998-07-10

A great deal of uncertainty persists regarding the exact nature of the interaction between autonomic nervous system activity and thyroid hormones in the control of heart rate and blood pressure. We now report on thyrotoxicosis produced by daily intraperitoneal (i.p.) injection of L-thyroxine (0.5 mg/kg body wt. in 1 ml of 5 mM NaOH for 5 days). Control rats received i.p. daily injections of the thyroxine solvent. In order to estimate the degree of autonomic activation in hyperthyroidism, specific blockers were administered intravenously: atropine (0.5 mg/kg), prazosin (1 mg/kg), atenolol (1 mg/kg) or the combination of atenolol and atropine. A jet of air was administered in other animals to induce sympathoactivation. Eight animals were studied in each group. The dose and duration of L-thyroxine treatment was sufficient to induce a significant degree of hyperthyroidism with accompanying tachycardia, systolic blood pressure elevation, increased pulse pressure, cardiac hypertrophy, weight loss, tachypnea and hyperthermia. In addition, the intrinsic heart period observed after double blockade (atenolol + atropine) was markedly decreased after treatment with L-thyroxine (121.5+/-3.6 ms vs. 141.2+/-3.7 ms, P < 0.01). Of the autonomic indices, vagal tone (difference between heart period obtained after atenolol and intrinsic heart period) was negatively linearly related to intrinsic heart period (r = 0.71, P < 0.05). Atenolol modified neither the heart period nor blood pressure variability in rats with hyperthyroidism and in these rats the jet of air did not significantly affect the heart period level. The thyrotoxicosis was associated with a reduction of the 0.4 Hz component of blood pressure variability (analyses on 102.4 s segments, modulus 1.10+/-0.07 vs. 1.41+/-0.06 mm Hg, P < 0.01) and prazosin was without effect on this 0.4 Hz component in these animals. These data show a functional diminution of the vascular and cardiac sympathetic tone in early experimental hyperthyroidism. The marked rise in the intrinsic heart rate could be the main determinant of tachycardia. The blood pressure elevation may reflexly induce vagal activation and sympathetic (vascular and cardiac) inhibition.

Ovarian ultrasound and ovarian and adrenal hormones before and after treatment for hyperthyroidism.

PubMed

Skjöldebrand Sparre, L; Kollind, M; Carlström, K

2002-01-01

To relate thyroid, steroid and pituitary hormones to ovarian ultrasonographic findings in hyperthyroid patients before and during treatment. Ultrasonography of the ovaries and serum hormone determination by immunoassay were performed before and during thiamazole therapy in 18 women of fertile age treated for hyperthyroidism at the Danderyd Hospital from 1996 to 1998. When hyperthyreotic, the patients had elevated serum levels of sex hormone-binding globulin (SHBG) and subnormal values of cortisol, free testosterone (fT) and dehydroepiandrosterone (DHEA). In the euthyreotic state following treatment, endocrine variables were normalized. Patients with a short duration of the disease had higher pretreatment levels of free thyroxine (fT4), SHBG and testosterone and lower corticosteroid binding globulin (CBG) and cortisol levels compared to patients with a long duration of the disease. The pretreatment ultrasonographic picture was abnormal in 16 of 18 patients. Of the 8 patients who were examined by ultrasonography after 3 months of treatment, all but 1 showed a normal picture. Samples from patients showing an abnormal ultrasonographic picture had significantly higher fT4 and lower free testosterone (fT) values than samples from patients with a normal ultrasonographic picture. Ultrasonographic findings showing a multicystic/multifollicular picture, resembling polycystic ovaries (PCO), in hyperthyroidism may be related to direct effects of thyroid hormones on the ovaries and/or altered intraovarian androgen environment due to elevated SHBG levels. It is highly recommended to assess the thyroid status in patients with multicystic/multifollicular ovaries/PCO. Copyright 2002 S. Karger AG, Basel

Primary hyperthyroidism--diagnosis and treatment. Indications and contraindications for radioiodine therapy.

PubMed

Gurgul, Edyta; Sowinski, Jerzy

2011-01-01

Isotope therapy is one of the methods used in primary hyperthyroidism. The therapy is based on short-range beta radiation emitted from radioactive iodine. Radioiodine administration must always be preceded by pharmacological normalization of thyroid function. Otherwise, post-radiation thyrocyte destruction and thyroid hormones release may lead to hyperthyroidism exacerbation. Indications for radioiodine therapy in Graves-Basedow disease include recurrent hyperthyroidism after thyrostatic treatment or thyroidectomy and side-effects observed during thyrostatic treatment. In toxic nodule, isotope therapy is the first choice therapy. Radioiodine is absorbed only in autonomous nodule. Therefore, it destroys only this area and does not damage the remaining thyroid tissue. In toxic goitre, radioiodine is used mostly in recurrent nodules. Absolute contraindications for radioiodine treatment are pregnancy and lactation. Relative contraindications are thyroid nodules suspected of malignancy and age under 15 years. In patients with thyroid nodules suspected of malignancy, radioiodine treatment may be applied as a preparation for surgery, if thyrostatic drugs are ineffective or contraindicated. In children, radioiodine therapy should be considered in recurrent toxic goitre and when thyrostatic drugs are ineffective. In patients with Graves-Basedow disease and thyroid-associated orbitopathy, radioiodine treatment may increase the inflammatory process and exacerbate the ophthalmological symptoms. However, thyroid-associated orbitopathy cannot be considered as a contraindication for isotope therapy. The potential carcinogenic properties of radioiodine, especially associated with tissues with high iodine uptake (thyroid, salivary glands, stomach, intestine, urinary tract, breast), have not been confirmed.

Thyroid Hormone Receptor Antagonists: From Environmental Pollution to Novel Small Molecules.

PubMed

Mackenzie, Louise S

2018-01-01

Thyroid hormone receptors (TRs) are nuclear receptors which control transcription, and thereby have effects in all cells within the body. TRs are an important regulator in many basic physiological processes including development, growth, metabolism, and cardiac function. The hyperthyroid condition results from an over production of thyroid hormones resulting in a continual stimulation of thyroid receptors which is detrimental for the patient. Therapies for hyperthyroidism are available, but there is a need for new small molecules that act as TR antagonists to treat hyperthyroidism. Many compounds exhibit TR antagonism and are considered detrimental to health. Some drugs in the clinic (most importantly, amiodarone) and environmental pollution exhibit TR antagonist properties and thus have the potential to induce hypothyroidism in some people. This chapter provides an overview of novel small molecules that have been specifically designed or screened for their TR antagonist activity as novel treatments for hyperthyroidism. While novel compounds have been identified, to date none have been developed sufficiently to enter clinical trials. Furthermore, a discussion on other sources of TR antagonists is discussed in terms of side effects of current drugs in the clinic as well as environmental pollution. © 2018 Elsevier Inc. All rights reserved.

Atrial fibrillation and hyperthyroidism: A literature review.

PubMed

Reddy, Vivek; Taha, Wael; Kundumadam, Shanker; Khan, Mazhar

Atrial fibrillation is the most common arrhythmia worldwide with increasing frequency noted with age. Hyperthyroidism is a well-known cause of atrial fibrillation with a 16%-60% prevalence of atrial fibrillation in patients with known hyperthyroidism Ross et al. (2016). While hyperthyroidism as a causative factor of atrial fibrillation is well established, this literature review aims to answer several questions on this topic including: 1. The relationship of atrial fibrillation to hyperthyroidism 2. Atrial fibrillation as a predictor of hyperthyroidism 3. The pathophysiology of thyrotoxic atrial fibrillation 4. Subclinical hyperthyroidism and the relationship with atrial fibrillation 5. Cardioversion and Catheter ablation of hyperthyroid patients with atrial fibrillation 6. Thrombotic risk of hyperthyroid patients with atrial fibrillation 7. Management of Thyrotoxic Atrial fibrillation 8. Pharmacological rhythm control in patients with hyperthyroidism and atrial fibrillation 9. Treatment of Hyperthyroidism to prevent atrial fibrillation 10. Clinical Implications of Hyperthyroidism and Atrial Fibrillation. Copyright © 2017 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

[Short-term memory characteristics of vibration intensity tactile perception on human wrist].

PubMed

Hao, Fei; Chen, Li-Juan; Lu, Wei; Song, Ai-Guo

2014-12-25

In this study, a recall experiment and a recognition experiment were designed to assess the human wrist's short-term memory characteristics of tactile perception on vibration intensity, by using a novel homemade vibrotactile display device based on the spatiotemporal combination vibration of multiple micro vibration motors as a test device. Based on the obtained experimental data, the short-term memory span, recognition accuracy and reaction time of vibration intensity were analyzed. From the experimental results, some important conclusions can be made: (1) The average short-term memory span of tactile perception on vibration intensity is 3 ± 1 items; (2) The greater difference between two adjacent discrete intensities of vibrotactile stimulation is defined, the better average short-term memory span human wrist gets; (3) There is an obvious difference of the average short-term memory span on vibration intensity between the male and female; (4) The mechanism of information extraction in short-term memory of vibrotactile display is to traverse the scanning process by comparison; (5) The recognition accuracy and reaction time performance of vibrotactile display compares unfavourably with that of visual and auditory. The results from this study are important for designing vibrotactile display coding scheme.

Hyperthyroidism in Childhood: Causes, When and How to Treat

PubMed Central

Léger, Juliane; Carel, Jean Claude

2013-01-01

Graves’ disease (GD) is the most common cause of hyperthyroidism in children. This review gives an overview and update of management of GD. Antithyroid drugs (ATD) are recommended as the initial treatment, but the major problem is the high relapse rate (30%) as remission is achieved after a first course of ATD. More prolonged medical treatment may increase the remission rate up to 50%. Alternative treatments, such as radioactive iodine or thyroidectomy, are considered in cases of relapse, lack of compliance, or ATD toxicity. Therefore, clinicians have sought prognostic indicators of remission. Relapse risk decreases with longer duration of the first course of ATD treatment, highlighting the positive impact of a long period of primary ATD treatment on outcome. The identification of other predictive factors such as severe biochemical hyperthyroidism at diagnosis, young age, and absence of other autoimmune conditions has made it possible to stratify patients according to the risk of relapse after ATD treatment, leading to improvement in patient management by facilitating the identification of patients requiring long-term ATD or early alternative therapy. Neonatal autoimmune hyperthyroidism is generally transient, occurring in only about 2% of the offspring of mothers with GD. Cardiac insufficiency, intrauterine growth retardation, craniostenosis, microcephaly and psychomotor disabilities are the major risks in these infants and highlight the importance of thyroid hormone receptor antibody determination throughout pregnancy in women with GD, as well as highlighting the need for early diagnosis and treatment of hyperthyroidism. Conflict of interest:None declared. PMID:23154161

Hyperthyroidism in childhood: causes, when and how to treat.

PubMed

Léger, Juliane; Carel, Jean Claude

2013-01-01

Graves' disease (GD) is the most common cause of hyperthyroidism in children. This review gives an overview and update of management of GD. Antithyroid drugs (ATD) are recommended as the initial treatment, but the major problem is the high relapse rate (30%) as remission is achieved after a first course of ATD. More prolonged medical treatment may increase the remission rate up to 50%. Alternative treatments, such as radioactive iodine or thyroidectomy, are considered in cases of relapse, lack of compliance, or ATD toxicity. Therefore, clinicians have sought prognostic indicators of remission. Relapse risk decreases with longer duration of the first course of ATD treatment, highlighting the positive impact of a long period of primary ATD treatment on outcome. The identification of other predictive factors such as severe biochemical hyperthyroidism at diagnosis, young age, and absence of other autoimmune conditions has made it possible to stratify patients according to the risk of relapse after ATD treatment, leading to improvement in patient management by facilitating the identification of patients requiring long-term ATD or early alternative therapy. Neonatal autoimmune hyperthyroidism is generally transient, occurring in only about 2% of the offspring of mothers with GD. Cardiac insufficiency, intrauterine growth retardation, craniostenosis, microcephaly and psychomotor disabilities are the major risks in these infants and highlight the importance of thyroid hormone receptor antibody determination throughout pregnancy in women with GD, as well as highlighting the need for early diagnosis and treatment of hyperthyroidism.

Late manifestation of subclinical hyperthyroidism after goitrogenesis in an index patient with a N670S TSH receptor germline mutation masquerading as TSH receptor antibody negative Graves' disease.

PubMed

Schaarschmidt, J; Paschke, S; Özerden, M; Jäschke, H; Huth, S; Eszlinger, M; Meller, J; Paschke, R

2012-12-01

In 27 families with familial non-autoimmune hyperthyroidism (FNAH) reported up to date, the onset of hyperthyroidism varies from 18 months to 60 years. Also the manifestation of goitres is variable in these families. A 74-year-old woman first presented at the age of 69 years with tachyarrhythmia and hypertension. After initial treatment of her hypertension and oral anticoagulation for her intermittent atrial fibrillation, a thyroid workup revealed a suppressed TSH and normal fT3 and fT4. TPO, TSH receptor (TSHR), and thyroglobulin antibodies were negative. Thyroid ultrasound revealed a thyroid volume of 102 ml with several nodules with diameters of up to 2.6 cm right and up to 1.8 cm left. Scintigraphy showed a homogeneous Technetium-99 m ((99 m)Tc) uptake of 1.27%. She was subsequently treated with 1 GBq radioiodine ((131)I). At the age of 74, her thyroid function was normal and her thyroid volume decreased to 90 ml. Because of the diffuse (99 m)Tc uptake and the negative TPO, TSHR, and thyroglobulin antibodies, genetic analysis of her TSHR gene was performed, in spite of her negative family history for hyperthyroidism. Sequencing revealed a N670S TSHR germline mutation. Previous in vitro characterisation of this TSHR mutation suggests a weak constitutive activity, yet the experimental data are ambiguous. This case illustrates the necessity to analyse patients with hyperthyroidism accompanied by diffuse (99 m)Tc uptake and negative TPO, TSHR, and thyroglobulin antibodies for TSHR germline mutations. Moreover, it demonstrates that TSHR germline mutations may first lead to longstanding nodular goitrogenesis before the late manifestation of subclinical hyperthyroidism. © Georg Thieme Verlag KG Stuttgart · New York.

Chronic severe axonal polyneuropathy associated with hyperthyroidism and multivitamin deficiency.

PubMed

Sugie, Kazuma; Umehara, Fujio; Kataoka, Hiroshi; Kumazawa, Aya; Ueno, Satoshi

2012-01-01

Hyperthyroidism is often associated with various neuromuscular disorders, most commonly proximal myopathy. Peripheral nerve involvement in hyperthyroidism is very uncommon and has rarely been reported. We describe a 29-year-old woman with untreated hyperthyroidism who presented with chronic severe axonal sensory-motor polyneuropathy. Peripheral nerve involvement developed together with other symptoms of hyperthyroidism 2 years before presentation. She also had anorexia nervosa for the past 6 months, resulting in multivitamin deficiency. Electrophysiological and pathological findings as well as clinical manifestations confirmed the diagnosis of severe axonal polyneuropathy. Anorexia nervosa has been considered a manifestation of untreated hyperthyroidism. We considered hyperthyroidism to be an important causal factor in the polyneuropathy in our patient, although peripheral nerve involvement in hyperthyroidism is rare. To our knowledge, this is the first documented case of chronic severe axonal polyneuropathy ascribed to both hyperthyroidism and multivitamin deficiency. Our findings strongly suggest that not only multivitamin deficiency, but also hyperthyroidism can cause axonal polyneuropathy, thus expanding the clinical spectrum of hyperthyroidism.

Evolution of a short-term study of lodgepole pine dwarf mistletoe vectors that turned into a long-term study of the remarkable gray jay on the Fraser Experimental Forest,Colorado, 1982-2009

Treesearch

Thomas H. Nicholls

2014-01-01

This is a summary of a 5-year short-term study that evolved into 28 years of long-term research on the US Department of Agriculture, Forest Service's Fraser Experimental Forest in Colorado. The study was begun in 1982 by Forest Service Research Scientists Thomas H. Nicholls and Frank G. Hawksworth to determine the importance of mammal and bird vectors in the long-...

Experimental Study of Short-Term Training in Social Cognition in Pre-Schoolers

ERIC Educational Resources Information Center

Houssa, Marine; Nader-Grosbois, Nathalie; Jacobs, Emilie

2014-01-01

Using an experimental approach, our study examined the differentiated effects on pre-schoolers' social cognition of two short-term social information processing (SIP) and Theory of Mind (ToM) training sessions dealing with emotions and beliefs. The links between ToM, SIP, and social adjustment or externalizing behavior were examined. 47…

Non-invasive detection and monitoring of experimental hydrocephalus with distortion product otoacoustic emissions.

PubMed

Ezerarslan, Hande; Beriat, Güçlü Kaan; Nurhat, Raziye Handan; Kazancı, Burak; Çelikkan, Ferda Topal; Sabuncuoğlu, Bizden; Sabuncuoğlu, Hakan

2016-08-01

We aimed to find out the effects of short term and long term hydrocephalus and intracranial ventricular volume changes on cochlear functions by using distortion product otoacoustic emission (DPOAE) in experimental hydrocephalus rat models for the first time in literature. This study was performed with 48 healthy, adult (8 weeks old), Sprague-Dawley rats which weighed between 200 and 240g. Six groups were formed in this study: short term control, short term sham, short term hydrocephalus, long term control, long term sham and long term hydrocephalus groups. Each group contained eight rats. Short term period was 4 weeks and long term period was 8 weeks after the study started. At the end of these periods, DPOAE measurements were performed and then rats were sacrificed to determine ventricular volumes. DPOAE values at all frequencies were significantly decreased in the short term hydrocephalus group when compared to the short term control and short term sham groups. DPOAE values at all frequencies were significantly decreased in the long term hydrocephalus group when compared to the long term control and long term sham groups. Besides, long term sham group which had higher ventricular volumes than long term control group also had lower DPOAE measurements. Significant associations were present between DPOAE measurements and ventricular volumes in hydrocephalus models. The functional disturbances in cochlear functions due to hydrocephalus have been demonstrated with DPOAE measurements in this study. DPOAE measurements may be thought as an easily applicable non-invasive method in detection and follow-up of patients with hydrocephalus. Our findings should be supported with clinical studies in humans. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A Short-Term Longitudinal Study of Memorial Development during Early Grade School.

ERIC Educational Resources Information Center

Kunzinger, Edward L., III

1985-01-01

Overt rehearsal and free recall performance was analyzed longitudinally in two experimental testing sessions at 7 and later at 9 years of age. Measures of short- and long-term memory recall, and two measures of input processing were obtained. Significant increases between age levels were exhibited by all variables except short-term memory.…

Short-Term Memory for Order but Not for Item Information Is Impaired in Developmental Dyslexia

ERIC Educational Resources Information Center

Hachmann, Wibke M.; Bogaerts, Louisa; Szmalec, Arnaud; Woumans, Evy; Duyck, Wouter; Job, Remo

2014-01-01

Recent findings suggest that people with dyslexia experience difficulties with the learning of serial order information during the transition from short-to long-term memory (Szmalec et al. "Journal of Experimental Psychology: Learning, Memory, & Cognition" 37(5): 1270-1279, 2011). At the same time, models of short-term memory…

Rapid restoration of bone mass after surgical management of hyperthyroidism: A prospective case control study in Southern India.

PubMed

Karunakaran, Poongkodi; Maharajan, Chandrasekaran; Mohamed, Kamaludeen N; Rachamadugu, Suresh V

2016-03-01

The rate and the extent of bone remineralization at cancellous versus cortical sites after treatment of hyperthyroidism is unclear. Few studies have examined the effect of operative management of hyperthyroidism on recovery of bone mass. To evaluate prospectively the bone mineral density (BMD), bone mineral content (BMC), and bone areal size at the spine, hip, and forearm before and after total thyroidectomy. A prospective case control observational study from August 2011 to July 2014 in a single center. This study evaluated 40 overt hyperthyroid patients and 31 age-matched euthyroid controls who were operative candidates. Bone indices were measured at baseline and 6-month postoperatively using dual energy x-ray absorptiometry. Serum levels of alkaline phosphatase and 25-hydroxy vitamin D3 (25OHD) were assessed. Baseline BMD of hyperthyroid subjects at the spine, hip, and forearm were less than euthyroid controls (P = .001) with concomitant increases in serum alkaline phosphatase (mean ± SD, 143 ± 72 vs 72 ± 23 IU/L control; P < .001). The 25OHD level was 24.3 ± 10.6 and 26.1 ± 14.6 ng/mL in patients and controls, respectively. Among hyperthyroid patients, posttreatment BMD expressed as g/cm(2) were 0.97 ± 0.12 (vs pretreatment 0.91 ± 0.14; P = .001) at the spine, 0.87 ± 0.12 (vs pretreatment 0.80 ± 0.13; P = .001) at the hip, and 0.67 ± 0.09 (vs pretreatment 0.64 ± 0.11; P = .191) at the forearm. The percent change in BMD was greatest at spine (8.3%) followed by the hip (7.6%) and forearm (3.0%). Operative management with total thyroidectomy improved the bone loss associated with hyperthyroidism as early as 6 months postoperatively at the hip and spine despite concomitant vitamin D deficiency. Delayed recovery of bone indices at the forearm, a cortical bone, requires further long-term evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

Immune stimulation improves endocrine and neural fetal outcomes in a model of maternofetal thyrotoxicosis.

PubMed

Ahmed, R G; Abdel-Latif, M; Mahdi, Emad A; El-Nesr, Khalid A

2015-12-01

The potentiation of the immune system in pregnant rats was performed with Complete Freund's Adjuvant [CFA; 20μl, subcutaneous at gestation day (GD) 18] in experimentally-induced hyperthyroidism by Levo-thyroxine (L-T4; 10μg/100g of b.w., intraperitoneal from GD 2 to 17). The potential effects on the fetal neuroendocrine function were evaluated by observing some histopathological investigations in pregnant rats and measuring some biochemical parameters in dams and their fetuses at GD 20. In hyperthyroid group, an increase in maternofetal serum thyroxine (T4), triiodothyronine (T3) and a decrease in thyrotropin (TSH) levels were noticed, while the concentrations of fetal serum growth hormone (GH) and insulin-like growth factor-1 (IGF1) levels were increased at tested GD with respect to control and CFA groups. Moreover, the activity of uterine and placental myeloperoxidase (MPO) was increased (P<0.001) in CFA and CFA-treated hyperthyroid groups in respect to control or hyperthyroid groups, respectively. The gestational thyrotoxicosis led to some histopathological lesions in uterine and placental tissues characterized by severe degeneration in trophoblast spongioblast cell layer with congestion, mild congested blood vessels in the endometrium and deficient in spiral artery remodeling. Although, the elevation in fetal serum transforming growth factor-beta (TGFβ) and cerebellar monoamines [norepineprine (NE), epinephrine (E), dopamine (DA) and 5-hydroxytryptamine (5-HT)] was observed, the reduction in fetal serum tumor necrosis factor-alpha (TNFα) and adipokines (Leptin and adiponectin) was detected. Treatment of dams with CFA showed an obviously reversing and protecting effect against hyperthyroid perturbations. Thus, the maternal CFA can be used in treatment of the fetal neuroendocrine dysfunctions. Copyright © 2015 Elsevier B.V. All rights reserved.

B cell-targeted therapy with anti-CD20 monoclonal antibody in a mouse model of Graves' hyperthyroidism

PubMed Central

Ueki, I; Abiru, N; Kobayashi, M; Nakahara, M; Ichikawa, T; Eguchi, K; Nagayama, Y

2011-01-01

Graves' disease is a B cell-mediated and T cell-dependent autoimmune disease of the thyroid which is characterized by overproduction of thyroid hormones and thyroid enlargement by agonistic anti-thyrotrophin receptor (TSHR) autoantibody. In addition to antibody secretion, B cells have recently been recognized to function as antigen-presenting/immune-modulatory cells. The present study was designed to evaluate the efficacy of B cell depletion by anti-mouse (m) CD20 monoclonal antibody (mAb) on Graves' hyperthyroidism in a mouse model involving repeated injection of adenovirus expressing TSHR A-subunit (Ad-TSHR289). We observe that a single injection of 250 µg/mouse anti-mCD20 mAb eliminated B cells efficiently from the periphery and spleen and to a lesser extent from the peritoneum for more than 3 weeks. B cell depletion before immunization suppressed an increase in serum immunoglobulin (Ig)G levels, TSHR-specific splenocyte secretion of interferon (IFN)-γ, anti-TSHR antibody production and development of hyperthyroidism. B cell depletion 2 weeks after the first immunization, a time-point at which T cells were primed but antibody production was not observed, was still effective at inhibiting antibody production and disease development without inhibiting splenocyte secretion of IFN-γ. By contrast, B cell depletion in hyperthyroid mice was therapeutically ineffective. Together, these data demonstrate that B cells are critical not only as antibody-producing cells but also as antigen-presenting/immune-modulatory cells in the early phase of the induction of experimental Graves' hyperthyroidism and, although therapeutically less effective, B cell depletion is highly efficient for preventing disease development. PMID:21235532

Radioiodine therapy versus antithyroid drugs in Graves' disease: a meta-analysis of randomized controlled trials.

PubMed

Wang, Junqi; Qin, Lan

2016-06-27

This meta-analysis was performed to compare radioiodine therapy with antithyroid drugs in terms of clinical outcomes, including development or worsening of ophthalmopathy, hyperthyroid cure rate, hypothyroidism, relapse rate and adverse events. Randomized controlled trials (RCTs) published in PubMed, Embase, Web of Science, SinoMed and National Knowledge Infrastructure, China, were systematically reviewed to compare the effects of radioiodine therapy with antithyroid drugs in patients with Graves' disease. Results were expressed as risk ratio with 95% confidence intervals (CIs) and weighted mean differences with 95% CIs. Pooled estimates were performed using a fixed-effects model or random-effects model, depending on the heterogeneity among studies. 17 RCTs involving 4024 patients met the inclusion criteria and were included. Results showed that radioiodine treatment has increased risk in new ophthalmopathy, development or worsening of ophthalmopathy and hypothyroidism. Whereas, compared with antithyroid drugs, radioiodine treatment seems to have a higher hyperthyroid cure rate, lower recurrence rate and lower incidence of adverse events. Radioiodine therapy is associated with a higher hyperthyroid cure rate and lower relapse rate compared with antithyroid drugs. However, it also increases the risk of ophthalmopathy and hypothyroidism. Considering that antithyroid drug treatment can be associated with unsatisfactory control of hyperthyroidism, we would recommend radioiodine therapy as the treatment of choice for patients with Graves' disease.

Thyroid hormones and female reproduction.

PubMed

Silva, Juneo F; Ocarino, Natália M; Serakides, Rogéria

2018-05-14

Thyroid hormones are vital for the proper functioning of the female reproductive system, since they modulate the metabolism and development of ovarian, uterine and placental tissues. Therefore, hypo- and hyperthyroidism may result in subfertility or infertility in both women and animals. Other well-documented sequelae of maternal thyroid dysfunctions include menstrual/estral irregularity, anovulation, abortion, preterm delivery, preeclampsia, intrauterine growth restriction, postpartum thyroiditis, and mental retardation in children. Several studies have been carried out involving prospective and retrospective studies of women with thyroid dysfunction, as well as in vivo and in vitro assays of hypo- and hyperthyroidism using experimental animal models and/or ovarian, uterine and placental cell culture. These studies have sought to elucidate the mechanisms by which thyroid hormones influence reproduction to better understand the physiology of the reproductive system and to provide better therapeutic tools for reproductive dysfunctions that originate from thyroid dysfunctions. Therefore, this review aims to summarize and update the available information related to the role of thyroid hormones in the morphophysiology of the ovary, uterus and placenta in women and animals and the effects of hypo- and hyperthyroidism on the female reproductive system.

Effects of experimental hyperthyroidism on protein turnover in skeletal and cardiac muscle as measured by [14C]tyrosine infusion.

PubMed Central

Carter, W J; Benjamin, W S; Faas, F H

1982-01-01

The effect of T3 (3,3',5-tri-iodothyronine) on protein turnover in skeletal and cardiac muscle was measured in intact rats by means of a 6 h [14C]tyrosine-infusion technique. Treatment with 25-30 micrograms of T3/100 g body wt. daily for 4-7 days increased the fractional rate of protein synthesis in skeletal muscle. Since the fractional growth rate of the muscle was decreased or unchanged, T3 treatment increased the rate of muscle protein breakdown. These findings suggest that increased protein degradation is an important factor in decreasing skeletal-muscle mass in hyperthyroidism. In contrast with skeletal muscle, T3 treatment for 7 days caused an equivalent increase in the rate of cardiac muscle growth and protein synthesis. This suggests that hyperthyroidism does not increase protein breakdown in heart muscle as it does in skeletal muscle. The failure of T3 to increase proteolysis in heart muscle may be due to a different action on the cardiac myocyte or to systemic effects of T3 which increase cardiac work. PMID:7115332

Oxidative Stress and Heart Failure in Altered Thyroid States

PubMed Central

Mishra, Pallavi; Samanta, Luna

2012-01-01

Increased or reduced action of thyroid hormone on certain molecular pathways in the heart and vasculature causes relevant cardiovascular derangements. It is well established that hyperthyroidism induces a hyperdynamic cardiovascular state, which is associated with a faster heart rate, enhanced left ventricular systolic and diastolic function whereas hypothyroidism is characterized by the opposite changes. Hyperthyroidism and hypothyroidism represent opposite clinical conditions, albeit not mirror images. Recent experimental and clinical studies have suggested the involvement of ROS tissue damage under altered thyroid status. Altered-thyroid state-linked changes in heart modify their susceptibility to oxidants and the extent of the oxidative damage they suffer following oxidative challenge. Chronic increase in the cellular levels of ROS can lead to a catastrophic cycle of DNA damage, mitochondrial dysfunction, further ROS generation and cellular injury. Thus, these cellular events might play an important role in the development and progression of myocardial remodeling and heart failure in altered thyroid states (hypo- and hyper-thyroidism). The present review aims at elucidating the various signaling pathways mediated via ROS and their modulation under altered thyroid state and the possibility of antioxidant therapy. PMID:22649319

Effects of experimental hyperthyroidism on protein turnover in skeletal and cardiac muscle as measured by [14C]tyrosine infusion.

PubMed

Carter, W J; Benjamin, W S; Faas, F H

1982-04-15

The effect of T3 (3,3',5-tri-iodothyronine) on protein turnover in skeletal and cardiac muscle was measured in intact rats by means of a 6 h [14C]tyrosine-infusion technique. Treatment with 25-30 micrograms of T3/100 g body wt. daily for 4-7 days increased the fractional rate of protein synthesis in skeletal muscle. Since the fractional growth rate of the muscle was decreased or unchanged, T3 treatment increased the rate of muscle protein breakdown. These findings suggest that increased protein degradation is an important factor in decreasing skeletal-muscle mass in hyperthyroidism. In contrast with skeletal muscle, T3 treatment for 7 days caused an equivalent increase in the rate of cardiac muscle growth and protein synthesis. This suggests that hyperthyroidism does not increase protein breakdown in heart muscle as it does in skeletal muscle. The failure of T3 to increase proteolysis in heart muscle may be due to a different action on the cardiac myocyte or to systemic effects of T3 which increase cardiac work.

The Effects of Phonological Short-Term Memory and Speech Perception on Spoken Sentence Comprehension in Children: Simulating Deficits in an Experimental Design

ERIC Educational Resources Information Center

Higgins, Meaghan C.; Penney, Sarah B.; Robertson, Erin K.

2017-01-01

The roles of phonological short-term memory (pSTM) and speech perception in spoken sentence comprehension were examined in an experimental design. Deficits in pSTM and speech perception were simulated through task demands while typically-developing children (N = 71) completed a sentence-picture matching task. Children performed the control,…

A Short-Term, Quasi-Experimental Evaluation of D.A.R.E.'s Revised Elementary School Curriculum

ERIC Educational Resources Information Center

Vincus, Amy A.; Ringwalt, Chris; Harris, Melissa S.; Shamblen, Stephen R.

2010-01-01

We present the short-term results of a quasi-experimental evaluation of the revised D. A. R. E. (Drug Abuse Resistance Education) curriculum. Study outcomes examined were D. A. R. E.'s effects on three substances, namely students' lifetime and 30-day use of tobacco, alcohol, and marijuana, as well as their school attendance and academic…

Effect of hyperthyroidism and its treatment on bone mineral content

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

Toh, S.H.; Claunch, B.C.; Brown, P.H.

1985-05-01

Patients with hyperthyroidism may develop osteopenia associated with fractures; however, there has been no general agreement on the incidence of osteopenia in hyperthyroidism or the recovery of the mineral loss after treatment of hyperthyroidism. The authors conducted a longitudinal prospective study on the effect of hyperthyroidism and its treatment on bone mineral content (BMC) using photon absorptiometry. They observed that both young and older hyperthyroid patients showed a significantly decreased baseline BMC compared with age- and sex-matched controls. They also observed a slight recovery of BMC in hyperthyroid patients at the two-year interval after a euthyroid state had been achieved.more » However, the BMC was still much lower than that of controls, and they did not find any significant restoration of BMC following ''cure'' of hyperthyroidism.« less

A Viscoelastic Constitutive Model Can Accurately Represent Entire Creep Indentation Tests of Human Patella Cartilage

PubMed Central

Pal, Saikat; Lindsey, Derek P.; Besier, Thor F.; Beaupre, Gary S.

2013-01-01

Cartilage material properties provide important insights into joint health, and cartilage material models are used in whole-joint finite element models. Although the biphasic model representing experimental creep indentation tests is commonly used to characterize cartilage, cartilage short-term response to loading is generally not characterized using the biphasic model. The purpose of this study was to determine the short-term and equilibrium material properties of human patella cartilage using a viscoelastic model representation of creep indentation tests. We performed 24 experimental creep indentation tests from 14 human patellar specimens ranging in age from 20 to 90 years (median age 61 years). We used a finite element model to reproduce the experimental tests and determined cartilage material properties from viscoelastic and biphasic representations of cartilage. The viscoelastic model consistently provided excellent representation of the short-term and equilibrium creep displacements. We determined initial elastic modulus, equilibrium elastic modulus, and equilibrium Poisson’s ratio using the viscoelastic model. The viscoelastic model can represent the short-term and equilibrium response of cartilage and may easily be implemented in whole-joint finite element models. PMID:23027200

Rare presentations of hyperthyroidism--Basedow's paraplegia and pancytopenia.

PubMed

Chen, Yi-Hsien; Lin, Hung-Jung; Chen, Kuo-Tai

2009-02-01

Typical presentations of hyperthyroidism are palpitation, nervousness, tremor, malaise, and weight loss. Hyperthyroidism affects nearly every system in the body, and some patients may manifest neurologic or hematologic symptoms. Atypical presentations of hyperthyroidism often pose a great challenge in diagnosis and treatment. We report a case of Basedow's paraplegia and pancytopenia that was precipitated by hyperthyroidism. The unusual manifestations led to unnecessary examinations and delayed the treatment of hyperthyroidism. The classical symptoms of Basedow's paraplegia are subacute symmetric weakness of the lower extremities with areflexia and sparing sensation or sphincter involvement. Control of the hyperthyroidism mitigated the neurologic and hematologic complications and prevented unnecessary studies.

[Reversible first-degree atrioventricular block due to hyperthyroidism].

PubMed

Çelebi, Aksüyek Savaş; Amasyalı, Basri

2017-04-01

Hyperthyroidism often causes tachyarrhythmia. Reversible atrioventricular block caused by hyperthyroidism is rare occurrence. Presently described is a case of atrioventricular block due to hyperthyroidism and recovery after antithyroid treatment.

Sentence Comprehension in Adolescents with down Syndrome and Typically Developing Children: Role of Sentence Voice, Visual Context, and Auditory-Verbal Short-Term Memory.

ERIC Educational Resources Information Center

Miolo, Giuliana; Chapman, Robins S.; Sindberg, Heidi A.

2005-01-01

The authors evaluated the roles of auditory-verbal short-term memory, visual short-term memory, and group membership in predicting language comprehension, as measured by an experimental sentence comprehension task (SCT) and the Test for Auditory Comprehension of Language--Third Edition (TACL-3; E. Carrow-Woolfolk, 1999) in 38 participants: 19 with…

CE with chemiluminescence detection for the determination of thyroxine in human serum.

PubMed

Mu, Xiaomei; Li, Shuting; Lu, Xin; Zhao, Shulin

2014-04-01

A sensitive and rapid approach to perform thyroxine (T4) assay by CE with chemiluminescence (CL) detection was developed. The sensitive detection was based on the enhancement effect of T4 on the CL reaction between luminol and potassium permanganate (KMnO4 ) in alkaline solution. A laboratory-built reaction flow cell and a photon counter were deployed for the CL detection. Experimental conditions for CL detection were studied in detail to achieve maximum assay sensitivity. Optimal conditions were found to be 5.0 × 10(-4) M luminol added to the CE running buffer and 9.2 × 10(-5) M KMnO4 in 0.072 M NaOH solution introduced postcolumn. In the optimized experimental conditions, the linear range for T4 detection was 6.0 × 10(-8) -6.0 × 10(-6) M, with the detection limit of 2.0 × 10(-8) M (S/N = 3). Six human serum samples from healthy subjects, hyperthyroid patients and hypothyroid patients were analyzed by the presented method. The serum level of T4 in healthy subjects was found be 9.0 × 10(-8) M, whereas the T4 level was found to be 15.6 × 10(-8) M in hyperthyroid patients and 1.3 × 10(-8) M in hypothyroid patients. The results suggested a potential application of the proposed assay in rapid primary diagnosis of diseases such as hyperthyroid and hypothyroid. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elevated Serum Fibroblast Growth Factor 21 Levels in Patients With Hyperthyroidism.

PubMed

Xiao, Fangsen; Lin, Mingzhu; Huang, Peiying; Zeng, Jinyang; Zeng, Xin; Zhang, Huijie; Li, Xiaoying; Yang, Shuyu; Li, Zhibin; Li, Xuejun

2015-10-01

Recent evidence from animal studies indicates that fibroblast growth factor 21 (FGF21), an endocrine hormone that regulates glucose, lipid metabolism, and energy homeostasis, is regulated by T3. However, the role of FGF21 in hyperthyroid patients is unknown. The objective was to study serum FGF21 levels in hyperthyroid patients and the association of serum FGF21 levels with hyperthyroidism. This was a case-control study. A total of 119 hyperthyroid patients and 108 healthy subjects were recruited. Of them, 41 hyperthyroid patients received thionamide treatment for 3 months until euthyroidism was obtained. Serum FGF21 levels were determined using the ELISA method. Serum FGF21 levels were significantly elevated in hyperthyroid patients as compared with normal subjects [median 290.67 (interquartile range, 156.60-502.33) vs 228.10 (169.85.25-320.10) pg/mL; P < .001]. After thionamide treatment, serum FGF21 levels in hyperthyroid patients declined markedly from 249.10 (139.10-444.00) to 106.90 (38.70-196.15) pg/mL (P < .001). Logistic regression revealed that FGF21, basal metabolic rate, low-density lipoprotein cholesterol, and alanine transaminase were significantly associated with hyperthyroidism. With adjustment for potential confounders, serum FGF21 remained independently associated with hyperthyroidism, with an adjusted odds ratio of 3.123 (95% confidence interval, 1.306-7.468) (P = .010). Serum FGF21 levels were elevated in patients with hyperthyroidism and declined after thionamide treatment. And serum FGF21 level was independently associated with hyperthyroidism.

Thyrotoxicosis: an under-recognised aetiology.

PubMed

Dave, Anjalee; Ludlow, Jason; Malaty, John

2015-05-20

A 53-year-old woman presented for evaluation of dizziness, shortness of breath and chest pain. She was found to be in atrial fibrillation with rapid ventricular response that was determined to be caused by iodine-induced thyrotoxicosis (from a CT scan with intravenous contrast 2 months prior to presentation). Jod-Basedow syndrome (iodine-induced hyperthyroidism) is infrequently considered as a cause of thyrotoxicosis, even when typical risk factors are present. However, this patient did not have typical risk factors: she did not reside in an iodine deficient area, did not have a prior diagnosis of thyroid disorder or goitre, had never been treated with thyroid medications or medications known to cause thyroid dysfunction and she presented later than is typical with this syndrome (2 months after receiving iodinated contrast). She had complete resolution of hyperthyroidism and atrial fibrillation 2 weeks later with no recurrence over the following 7 months. 2015 BMJ Publishing Group Ltd.

Thyrotoxicosis: an under-recognised aetiology

PubMed Central

Dave, Anjalee; Ludlow, Jason; Malaty, John

2015-01-01

A 53-year-old woman presented for evaluation of dizziness, shortness of breath and chest pain. She was found to be in atrial fibrillation with rapid ventricular response that was determined to be caused by iodine-induced thyrotoxicosis (from a CT scan with intravenous contrast 2 months prior to presentation). Jod-Basedow syndrome (iodine-induced hyperthyroidism) is infrequently considered as a cause of thyrotoxicosis, even when typical risk factors are present. However, this patient did not have typical risk factors: she did not reside in an iodine deficient area, did not have a prior diagnosis of thyroid disorder or goitre, had never been treated with thyroid medications or medications known to cause thyroid dysfunction and she presented later than is typical with this syndrome (2 months after receiving iodinated contrast). She had complete resolution of hyperthyroidism and atrial fibrillation 2 weeks later with no recurrence over the following 7 months. PMID:25994428

Effect of hypo- and hyperthyroidism on gastric myoelectrical activity.

PubMed

Gunsar, Fulya; Yilmaz, Sema; Bor, Serhat; Kumanlioğlu, Kamil; Cetinkalp, Sevki; Kabalak, Taylan; Ozutemiz, Omer Ahmet

2003-04-01

Although hypo- and hyperthyroid patients have different symptoms in the gastrointestinal tract, the mechanism of thyroid action on the gut remains poorly understood. Thus the aim of this study was to investigate the effect of hypo- and hyperthyroidism on gastric myoelectrical activity, gastric emptying, dyspeptic symptoms. Twenty-two hyperthyroid (median age 45, 15 females) and 11 hypothyroid (median age 42, 10 females) patients were included into the study. Dyspepsia score, hypo- and hyperthyroid symptom scale, abdominal ultrasonography and upper gastrointestinal endoscopy were performed. Gastric myoelectrical activity was measured by electrogastrograpy (EGG) before and after therapy both preprandially and postprandially and compared with age, gender, and body-matched controls (12 for hypothyroid, 15 for hyperthyroid patients). Radionuclide gastric emptying studies were performed with a solid meal. Hypothyroid patients revealed a significant increase in preprandial tachygastria as compared with controls (12.3% vs 4.8%). The percentage of preprandial normal slow waves (2.4-3.7 cpm) was below 70% (dysmotility) in 7 of 11 hypothyroid patients versus 2 of 12 controls (P < 0.05). Hyperthyroid patients revealed a significantly higher preprandial (3.1 vs 2.8) and postprandial (3.4 vs 3) DF when compared with the controls (P < 0.05). A higher percentage of postprandial taschygastria (7.9 vs 0) was present in hyperthyroid patients than in the controls (P < 0.05). The decrease on postprandial EGG power (power ratio < 1) was observed in 7 patients the in hyperthyroid group and 1 in controls (P < 0.05). The percentage of postprandial normal slow waves was below 70% in 10 of 20 hyperthyroid patients vs 1 of 15 controls (P < 0.05). After therapy these differences disappeared in the euthyroid state. The hypo- and hyperthyroid symptom scale correlated to dyspepsia score. Dyspepsia score in hyperthyroidism correlated to power ratios in hyperthyroid patients. We detected some correlations between serum levels of fT3 or fT4 and some EGG parameters in hypo- and hyperthyroidism. Dyspepsia score and hypo- and hyperthyroid symptom scale were improved significantly after therapy in the euthyroid state. In conclusions, we showed gastric dysrhythmia by EGG in both hypo- and hyperthyroid patients. Dyspeptic symptoms correlated to the activity of thyroid disease. After therapy, these findings and dyspeptic symptoms improved in the euthyroid state. Abnormalities of power ratios may be responsible of dyspeptic symptoms in hyperthyroid patients. EGG may be a useful and noninvasive tool for detecting gastric disturbances during hypo- and hyperthyroidism.

Iopanoic acid-induced decrease of circulating T3 causes a significant increase in GH responsiveness to GH releasing hormone in thyrotoxic patients.

PubMed

Ramos-Dias, J C; Lengyel, A M

1999-10-01

Thyroid hormones participate in GH synthesis and secretion, and an impaired GH response to many pharmacological stimuli, including GH releasing hormone (GHRH), has been found in thyrotoxicosis. Although the mechanisms involved in this process have not been fully elucidated, there is evidence that thyroid hormones could act at both hypothalamic and pituitary levels. There are no data in the literature about the effect of an acute reduction of circulating T3 levels on GH secretion in hyperthyroidism. The GH responsiveness to GHRH was therefore evaluated in a group of hyperthyroid patients during short-term treatment with iopanoic acid. Iopanoic acid is a compound that induces a rapid decrease in serum T3 levels, mainly by inhibition of peripheral conversion of T4 to T3. To the authors' knowledge, there is no evidence of a direct effect of iopanoic acid on GH secretion. Hyperthyroid patients were submitted to a GHRH test (100 microg, i.v.) before (day 0), and on days 4, 7 and 15 after oral treatment with iopanoic acid (3 g every 3 days) and propylthiouracil (200 mg every 8 h). A group of normal control subjects was also submitted to a single GHRH test (100 microg, i.v.). Nine patients with thyrotoxicosis (eight women, one man), with a mean age of 34 years, were studied. All patients had high serum levels of total T3 and total T4, and suppressed TSH levels. None of them had taken any medication for at least 3 months before the study. The patients were compared with a group of nine control subjects (five women, four men) with a mean age of 31 years. GH and TSH were measured by immunofluorometric assays. Total T3, total T4 and IGF-I were determined by radioimmunoassay. Albumin levels were measured by a colorimetric method. Iopanoic acid induced a rapid and maintained decrease in serum T3 concentrations, with a significant reduction on days 4, 7 and 15 compared with pre-treatment values. In hyperthyroidism, peak GH levels (mean +/- SE mU/l) after GHRH were significantly higher on day 15 (24.4 +/- 3.8) than those observed on days 0 (14.2 +/- 1.6), 4 (15.2 +/- 3.0) and 7 (19.6 +/- 5.0). There was a 79% increase in this response on day 15 compared with the pre-treatment period. Hyperthyroid patients had a blunted GH response to GHRH on days 0, 4 and 7 in comparison with control subjects. However, on day 15, no differences were observed between the area under the curve (mean +/- SE mU/l.120 min) in thyrotoxic patients (1770 +/- 306) and in the control group (3300 +/- 816). IGF-I and albumin levels did not change during iopanoic acid administration. The results show that an acute reduction in serum T3 levels elicits an increase in GH responsiveness to GHRH in hyperthyroidism. Although the mechanisms involved in this process are still unknown, it is possible that T3 influences GH responsiveness to GHRH via hypothalamic somatostatin release. Alternatively, T3 could have a direct effect at the pituitary somatotroph, modulating GHRH intracellular pathways.

Validation of a Supplemental Reading Intervention for First-Grade Children

ERIC Educational Resources Information Center

Case, Lisa Pericola; Speece, Deborah L.; Silverman, Rebecca; Ritchey, Kristen D.; Schatschneider, Christopher; Cooper, David H.; Montanaro, Elizabeth; Jacobs, Dawn

2010-01-01

This experimental study was designed to validate a short-term supplemental reading intervention for at-risk first-grade children. Although substantial research on long-term supplemental reading interventions exists, less is known about short-term interventions. Thirty first-grade children were randomly assigned to intervention or control…

Short-term fasting alters cytochrome P450-mediated drug metabolism in humans.

PubMed

Lammers, Laureen A; Achterbergh, Roos; de Vries, Emmely M; van Nierop, F Samuel; Klümpen, Heinz-Josef; Soeters, Maarten R; Boelen, Anita; Romijn, Johannes A; Mathôt, Ron A A

2015-06-01

Experimental studies indicate that short-term fasting alters drug metabolism. However, the effects of short-term fasting on drug metabolism in humans need further investigation. Therefore, the aim of this study was to evaluate the effects of short-term fasting (36 h) on P450-mediated drug metabolism. In a randomized crossover study design, nine healthy subjects ingested a cocktail consisting of five P450-specific probe drugs [caffeine (CYP1A2), S-warfarin (CYP2C9), omeprazole (CYP2C19), metoprolol (CYP2D6), and midazolam (CYP3A4)] on two occasions (control study after an overnight fast and after 36 h of fasting). Blood samples were drawn for pharmacokinetic analysis using nonlinear mixed effects modeling. In addition, we studied in Wistar rats the effects of short-term fasting on hepatic mRNA expression of P450 isoforms corresponding with the five studied P450 enzymes in humans. In the healthy subjects, short-term fasting increased oral caffeine clearance by 20% (P = 0.03) and decreased oral S-warfarin clearance by 25% (P < 0.001). In rats, short-term fasting increased mRNA expression of the orthologs of human CYP1A2, CYP2C19, CYP2D6, and CYP3A4 (P < 0.05), and decreased the mRNA expression of the ortholog of CYP2C9 (P < 0.001) compared with the postabsorptive state. These results demonstrate that short-term fasting alters cytochrome P450-mediated drug metabolism in a nonuniform pattern. Therefore, short-term fasting is another factor affecting cytochrome P450-mediated drug metabolism in humans. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Pediatric pulmonary arterial hypertension and hyperthyroidism: a potentially fatal combination.

PubMed

Trapp, Christine M; Elder, Robert W; Gerken, Adrienne T; Sopher, Aviva B; Lerner, Shulamit; Aranoff, Gaya S; Rosenzweig, Erika B

2012-07-01

Patients with pulmonary arterial hypertension (PAH) who develop hyperthyroidism are at risk for acute cardiopulmonary decompensation and death. We present a series of eight idiopathic PAH/heritable PAH pediatric patients who developed hyperthyroidism between 1999 and 2011. Institutional Review Board approval was obtained; informed consent was waived due to the retrospective nature of the series. All eight patients were receiving iv epoprostenol; five of the eight patients presented with acute cardiopulmonary decompensation in the setting of hyperthyroidism. In the remaining three patients, hyperthyroidism was detected during routine screening of thyroid function tests. The one patient who underwent emergency thyroidectomy was the only survivor of those who presented in cardiopulmonary decline. Aggressive treatment of the hyperthyroid state, including emergency total thyroidectomy and escalation of targeted PAH therapy and β-blockade when warranted, may prove lifesaving in these patients. Prompt thyroidectomy or radioactive iodine ablation should be considered for clinically stable PAH patients with early and/or mild hyperthyroidism to avoid potentially life-threatening cardiopulmonary decompensation. Although the association between hyperthyroidism and PAH remains poorly understood, the potential impact of hyperthyroidism on the cardiopulmonary status of PAH patients must not be ignored. Hyperthyroidism must be identified early in this patient population to optimize intervention before acute decompensation. Thyroid function tests should be checked routinely in patients with PAH, particularly those on iv epoprostenol, and urgently in patients with acute decompensation or symptoms of hyperthyroidism.

An improved Graves' disease model established by using in vivo electroporation exhibited long-term immunity to hyperthyroidism in BALB/c mice.

PubMed

Kaneda, Toshio; Honda, Asako; Hakozaki, Atsushi; Fuse, Tetsuya; Muto, Akihiro; Yoshida, Tadashi

2007-05-01

In Graves' disease, the overstimulation of the thyroid gland and hyperthyroidism are caused by autoantibodies directed against the TSH receptor (TSHR) that mimics the action of TSH. The establishment of an animal model is an important step to study the pathophysiology of autoimmune hyperthyroidism and for immunological analysis. In this study, we adopted the technique of electroporation (EP) for genetic immunization to achieve considerable enhancement of in vivo human TSHR (hTSHR) expression and efficient induction of hyperthyroidism in mice. In a preliminary study using beta-galactosidase (beta-gal) expression vectors, beta-gal introduced into the muscle by EP showed over 40-fold higher enzymatic activity than that introduced via previous direct gene transfer methods. The sustained hTSHR mRNA expression derived from cDNA transferred by EP was detectable in muscle tissue for at least 2 wk by RT-PCR. Based on these results, we induced hyperthyroidism via two expression vectors inserted with hTSHR or hTSHR289His cDNA. Consequently, 12.0-31.8% BALB/c mice immunized with hTSHR and 79.2-95.7% immunized with hTSHR289His showed high total T(4) levels due to the TSHR-stimulating antibody after three to four times repeated immunization by EP, and thyroid follicles of which were hyperplastic and had highly irregular epithelium. Moreover, TSHR-stimulating antibody surprisingly persisted more than 8 months after the last immunization. These results demonstrate that genetic immunization by in vivo EP is more efficient than previous procedures, and that it is useful for delineating the pathophysiology of Graves' disease.

Preoperative management in patients with Graves' disease.

PubMed

Piantanida, Eliana

2017-10-01

Graves' disease is the most frequent cause of hyperthyroidism in iodine-sufficient geographical areas and is characterized by the presence in patients' serum of autoantibodies directed against the thyrotropin receptor (TRAb) that cause overproduction and release of thyroid hormones. Clinical presentation results from both hyperthyroidism and underlying autoimmunity. The diagnosis is based on characteristic clinical features and biochemical abnormalities. If serum thyrotropin (TSH) is low, serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations should be measured to distinguish between subclinical (with normal circulating thyroid hormones) and overt hyperthyroidism (with increased circulating thyroid hormones). Graves' disease is treated with any of three effective and relatively safe initial treatment options: antithyroid drugs (ATDs), radioactive iodine ablation (RAIU), and surgery. Total thyroidectomy is favored in several clinical situations, such as intolerance, ineffectiveness or recurrence after ATD treatment, radioiodine therapy contraindicated, documented or suspected thyroid malignancy, one or more large thyroid nodules, coexisting moderate-to-severe active Graves' orbitopathy, women planning a pregnancy within 6 months. Whenever surgery is selected as treatment, selection of an expert high-volume thyroid surgeons is fundamental and careful preoperative management is essential to optimize surgical outcomes. Pretreatment with ATDs in order to promptly achieve the euthyroid state is recommended to avoid the risk of precipitating thyroid storm during surgery. For the majority of patients, euthyroidism is achieved after few weeks of ATD treatment. Beta-blockers, such as propranolol, are often added effectively to control hyperthyroid symptoms. Saturated solution of potassium iodide (SSKI) or potassium iodine (Lugol's solution), given for a short period prior to surgery, in order to reduce both thyroid hormone release and thyroid gland vascularity, is beneficial to decrease intra-operative blood loss.

[Hyperthyroidism in children at the University Hospital in Dakar (Senegal)].

PubMed

Boiro, Djibril; Diédhiou, Demba; Niang, Babacar; Sow, Djiby; Mbodj, Mandiaye; Sarr, Anna; Ndongo, Aliou Abdoulaye; Thiongane, Aliou; Guèye, Modou; Thiam, Lamine; Seck, Ndiogou; Dieng, Yaay Joor; Ba, Abou; Ba, Idrissa Demba; Diallo, Ibrahima Mané; Ndiaye, Ousmane; Diop, Said Nourou

2017-01-01

Hyperthyroidism in children is rare and constitutes a problem because of its psychosomatic impact. This study aimed to present an overview of the state of knowledge on these aspects in children from Dakar. We conducted a multicenter, descriptive study over a period of 15 years. We evaluated the epidemiological, clinical and etiologic aspects of hyperthyroidism in children. 239 patients were included in the study with a prevalence of 2.4%, a sex ratio (M/F) of 0.36 and an average age of 10.8 years. The inclusion criteria were being the eldest son in a family(26.3%), being advanced (36.9%) or delayed (12.5%) in maturation, having short stature (40.1%). It was caused by Graves' disease in 90.3% of cases with psychoaffective factor in 22.1%. On a clinical point of view tachycardia (92.4%), goiter (91.1%), exophthalmia (81.8%), weight loss (69.8%) prevailed but with bed-wetting (30.2%) and psychic manifestations (3.1%). Cardiovascular and cutaneous manifestations were positively associated with age (p < 0.05). Goiter was associated with female sex (p = 0.005), cardiovascular (p = 0.02), neuropsychic (p = 0.03), skin (p = 0.03) signs and diarrhea (p = 0.03). Free T4 was correlated with age (p = 0.007), diarrhea (p = 0.021), anxiety (p = 0.024), heart rate (p = 0.00) and Graves' disease (p = 0.04). More voluminous the goiter, higher the free T4 (p = 0.007). Hyperthyroidism in children differs from that in adults because of induction factors, growth disturbances and enuresis. Age and sex seem to favor the clinical picture of thyrotoxicosis and its associated signs.

Prevalence of thyrotropin receptor germline mutations and clinical courses in 89 hyperthyroid patients with diffuse goiter and negative anti-thyrotropin receptor antibodies.

PubMed

Nishihara, Eijun; Fukata, Shuji; Hishinuma, Akira; Amino, Nobuyuki; Miyauchi, Akira

2014-05-01

We studied the frequency of thyrotropin (TSH) receptor mutations in hyperthyroid patients with diffuse goiter and negative TSH receptor antibodies (TRAb), and the clinical pictures of the hyperthyroid patients in the presence and absence of mutations. From 2003 through 2012, 89 hyperthyroid patients with diffuse goiter and negative TRAb based on a second- or third-generation assay underwent sequence analysis of the TSH receptor gene from peripheral leukocytes. The outcome of hyperthyroidism in patients with a TSH receptor mutation and their affected family members was compared with that in patients without any mutation after a 1-10-year follow-up. Germline mutations of the TSH receptor occurred in 4 of the 89 patients (4.5%), including 3 definitive constitutively activating mutations (L512Q, E575K, and D617Y). The main difference in the clinical outcome of hyperthyroidism was that no patients with a TSH receptor mutation achieved euthyroidism throughout the follow-up, while 23.5% of patients without any mutation entered remission. The progression from subclinical to overt hyperthyroidism was not significantly different between patients with or without a mutation. Meanwhile, 10.3% of TRAb-negative patients without any TSH receptor mutation developed TRAb-positive Graves' hyperthyroidism during the follow-up. The prevalence of nonautoimmune hyperthyroidism with TSH receptor mutations is lower than that of latent Graves' disease in TRAb-negative patients with hyperthyroidism. However, all affected patients with a TSH receptor mutation showed persistent hyperthyroidism regardless of subclinical or overt hyperthyroidism throughout the follow-up.

The Influence of Antithyroid Drug Discontinuation to the Therapeutic Efficacy of (131)I in Hyperthyroidism.

PubMed

Kartamihardja, A Hussein Sundawa; Massora, Stepanus

2016-01-01

The influence of antithyroid drugs (ATDs) on the therapeutic efficacy of radioactive iodine in hyperthyroidism is still controversial. The aim of this study was to evaluate the effect of ATD discontinuation to the therapeutic efficacy of I-131 in hyperthyroidism patients with long-term ATD treatment. Retrospective study was done to 39 subjects with hyperthyroidism who had been treated with doses of 300 MBq radioactive iodine. The subjects were divided into three groups: Group I (n = 14) had been using ATDs for more than one year and discontinued more than three days; group II (n = 14) had been using ATDs for more than one year but discontinued only for three days or less, and group III (n = 11) has never been used any ATD before radioactive iodine treatment. There was a significant difference in the therapeutic efficacy after three months of radioactive iodine treatment between group I and group II (P = 0.018), group II and group III (P = 0.017), but not between group I and group III (P = 1.0). There was no observed difference on the therapeutic efficacy between the three groups at 6 months after radioactive iodine therapy (P = 0.143). Administration of ATDs more than 1 year without discontinuation decreased response of radioactive iodine treatment in 3 months follow-up. Discontinuation of ATDs for more than 3 days before radioactive iodine treatment is recommended.

Radioiodine therapy versus antithyroid drugs in Graves' disease: a meta-analysis of randomized controlled trials

PubMed Central

Qin, Lan

2016-01-01

Objective: This meta-analysis was performed to compare radioiodine therapy with antithyroid drugs in terms of clinical outcomes, including development or worsening of ophthalmopathy, hyperthyroid cure rate, hypothyroidism, relapse rate and adverse events. Methods: Randomized controlled trials (RCTs) published in PubMed, Embase, Web of Science, SinoMed and National Knowledge Infrastructure, China, were systematically reviewed to compare the effects of radioiodine therapy with antithyroid drugs in patients with Graves' disease. Results were expressed as risk ratio with 95% confidence intervals (CIs) and weighted mean differences with 95% CIs. Pooled estimates were performed using a fixed-effects model or random-effects model, depending on the heterogeneity among studies. Results: 17 RCTs involving 4024 patients met the inclusion criteria and were included. Results showed that radioiodine treatment has increased risk in new ophthalmopathy, development or worsening of ophthalmopathy and hypothyroidism. Whereas, compared with antithyroid drugs, radioiodine treatment seems to have a higher hyperthyroid cure rate, lower recurrence rate and lower incidence of adverse events. Conclusion: Radioiodine therapy is associated with a higher hyperthyroid cure rate and lower relapse rate compared with antithyroid drugs. However, it also increases the risk of ophthalmopathy and hypothyroidism. Advances in knowledge: Considering that antithyroid drug treatment can be associated with unsatisfactory control of hyperthyroidism, we would recommend radioiodine therapy as the treatment of choice for patients with Graves' disease. PMID:27266544

The Influence of Antithyroid Drug Discontinuation to the Therapeutic Efficacy of 131I in Hyperthyroidism

PubMed Central

Kartamihardja, A. Hussein Sundawa; Massora, Stepanus

2016-01-01

The influence of antithyroid drugs (ATDs) on the therapeutic efficacy of radioactive iodine in hyperthyroidism is still controversial. The aim of this study was to evaluate the effect of ATD discontinuation to the therapeutic efficacy of I-131 in hyperthyroidism patients with long-term ATD treatment. Retrospective study was done to 39 subjects with hyperthyroidism who had been treated with doses of 300 MBq radioactive iodine. The subjects were divided into three groups: Group I (n = 14) had been using ATDs for more than one year and discontinued more than three days; group II (n = 14) had been using ATDs for more than one year but discontinued only for three days or less, and group III (n = 11) has never been used any ATD before radioactive iodine treatment. There was a significant difference in the therapeutic efficacy after three months of radioactive iodine treatment between group I and group II (P = 0.018), group II and group III (P = 0.017), but not between group I and group III (P = 1.0). There was no observed difference on the therapeutic efficacy between the three groups at 6 months after radioactive iodine therapy (P = 0.143). Administration of ATDs more than 1 year without discontinuation decreased response of radioactive iodine treatment in 3 months follow-up. Discontinuation of ATDs for more than 3 days before radioactive iodine treatment is recommended. PMID:27134556

Effect of propranolol on heart rate variability in hyperthyroidism.

PubMed

Tankeu, Aurel T; Azabji-Kenfack, Marcel; Nganou, Chris-Nadège; Ngassam, Eliane; Kuate-Mfeukeu, Liliane; Mba, Camille; Dehayem, Mesmin Y; Mbanya, Jean-Claude; Sobngwi, Eugene

2018-02-22

We aimed to determine the effect of propanolol on heart rate variability (HRV) in hyperthyroidism before antithyroid treatment. This was a before and after study, on ten patients presenting overt hyperthyroidism naïve to treatment. In each patient, a resting electrocardiogram was done followed by estimation of cardiac autonomic dysfunction during five maneuvers (Ewing battery tests). Long term HRV measurement was done using 24 h ambulatory electrocardiographic recording. This automatically provided estimation of HRV using SDNN and RMSSD index, LF, HF, and HF/LF ratio. After baseline investigations, 40 mg of propanolol was given twice a day for 3 days and same parameters were measured after 72 h of treatment. Our patients were aged 40 ± 10 years. Propanolol significantly reduced RR and HR interval (669 ms vs 763 ms and 91 vs 79 bpm; p < 0.01). QT and PR space were significantly extended (360 vs 384 ms and 133 vs 172 ms; p = 0.01). It increases QRS complex and blood pressure response to sustained handgrip but failed to modify previously decreased heart response to deep breathing. HRV parameters such as SDNN, RMSSD, LF, HF and sympathovagal balance estimate by HF/LF ratio remained unchanged. Although a significant reduction in heart excitability, propanolol failed to restore a good sympathovagal balance in hyperthyroidism. Trial registration NCT03393728 "Retrospectively registered".

Coexistence of adult-onset Still's disease and autoimmune hyperthyroidism in a patient who responded to corticosteroids and β-blocker.

PubMed

Chen, Hsiao-Shuang; Yu, Kuang-Hui; Ho, Huei-Huang

2010-12-01

The pathogenesis of adult-onset Still's disease (AOSD), which is currently thought to be an autoimmune disorder, may share similarities with autoimmune hyperthyroidism. This report describes a middle-aged woman in whom hyperthyroidism and Still's disease developed concurrently. During the course of her illness, the hyperthyroidism was observed to be aggravated whenever her AOSD was in the active stage. After her AOSD activity was controlled, her hyperthyroidism improved clinically. The extent of activation of her hyperthyroidism was observed in parallel to the extent of activation of her AOSD. Furthermore, the patient developed neutropenia after receiving either propylthiouracil (PTU) or methimazole, both of which are standard accepted medications for treatment of hyperthyroidism. Immune mechanisms contributed to PTU induced neutropenia have been proposed, and hyperthyroid patients treated with standard antithyroid agents should be monitored for blood cell counts especially for AOSD patients. Corticosteroid may effect Graves' disease activity, and steroids may play a role in the treatment of hyperthyroidism if a patient had drug allergies to antithyroid agents.

Cardioprotective effect of hyperthyroidism on the stunned rat heart during ischaemia-reperfusion: energetics and role of mitochondria.

PubMed

Ragone, María Inés; Bonazzola, Patricia; Colareda, Germán A; Consolini, Alicia E

2015-06-01

What is the central question of this study? Hyperthyroidism is a cardiac risk factor, but thyroid therapy is used on myocardial stunning. What is the consequence of hyperthyroidism for mitochondrial metabolism and Ca(2+) handling of the postischaemic stunned heart? What is the main finding and its importance? Hyperthyroidism reduced stunning and improved muscle economy of the postischaemic rat heart. The activities of the mitochondrial sodium-calcium exchanger and mitochondrial K(+) channel in hyperthyroid rat hearts were different from those in the euthyroid rat hearts. These findings contribute to the understanding of mitochondrial bioenergetics in pathology and support thyroid therapy in the stunning induced by ischaemia. Transient ischaemia and hyperthyroidism are cardiovascular risk factors. Nevertheless, 3,5,3'-triiodothyronine/thyroxine therapy has been used to revert myocardial stunning. We studied the influence of hyperthyroidism on the role played by mitochondria in myocardial stunning consequent to ischaemia-reperfusion. Rats were injected s.c. daily with 20 μg kg(-1) triiodothyronine for 15 days (HpT group). Isolated ventricles from either HpT or euthyroid (EuT) rats were perfused in a calorimeter, and left intraventricular pressure (in millimetres of mercury) and heat release (Ht; in milliwatts per gram) were measured. Stunning was evoked by 20 min of no-flow ischaemia and 45 min reperfusion. The HpT hearts developed higher postischaemic contractile recovery (PICR) and improved total muscle economy (P/Ht) with lower diastolic contracture (ΔLVEDP) than EuT hearts. Release of Ca(2+) from the sarcoplasmic reticulum during reperfusion with 10 mm caffeine in low-[Na(+) ] Krebs solution evoked a higher contracture in EuT than in HpT hearts. Blockade of the mitochondrial sodium-calcium exchanger with clonazepam increased ΔLVEDP and reduced P/Ht and PICR in HpT but not in EuT hearts. The clonazepam-induced dysfunction in HpT hearts was reduced by ciclosporin, suggesting a dependance on activation of the mitochondrial permeability transition pore. Blockade of the mitochondrial Ca(2+) uniporter with Ru360 reduced P/Ht and PICR to ∼10% in both HpT and EuT hearts. Blockade of mitochondrial K(+) channels with 5-hydroxydecanoate increased LVEDP and reduced PICR and P/Ht in HpT hearts, while it only increased LVEDP in EuT hearts. The results suggest that hyperthyroidism prevents the stunning with high dependence on the mitochondrial sodium-calcium exchanger and mitochondrial K(+) channels. Both HpT and EuT hearts showed a similar and critical role of the uniporter. The HpT hearts have a slow sarcoplasmic reticulum Ca(2+) loss and low mitochondrial Ca(2+) uptake. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

Electrophysiological correlates of higher states of consciousness during sleep in long-term practitioners of the Transcendental Meditation program.

PubMed

Mason, L I; Alexander, C N; Travis, F T; Marsh, G; Orme-Johnson, D W; Gackenbach, J; Mason, D C; Rainforth, M; Walton, K G

1997-02-01

Standard ambulatory night sleep electroencephalograph (EEG) of 11 long-term practitioners of the Transcendental Meditation (TM) program reporting "higher states of consciousness" during sleep (the experimental group) was compared to that of nine short-term practitioners and 11 non-practitioners. EEG tracings during stages 3 and 4 sleep showed the experimental group to have: 1) theta-alpha activity simultaneously with delta activity and 2) decreased chin electromyograph (EMG) during deep sleep (p = 0.002) compared to short-term practitioners. Spectral analysis fast Fourier transform (FFT) data of the first three cycles showed that: 3) the experimental subjects had significantly greater theta 2 (6-8 Hz)-alpha 1 (8-10 Hz) relative power during stages 3 and 4 than the combined control groups [t(30) = 5.5, p = 0.0000008] with no difference in time in delta; 4) there was a graded difference across groups during stages 3 and 4 in theta 2-alpha 1 power, with experimentals having greater power than short-term practitioners, who in turn had greater power than non-practitioners [t(30) = 5.08, p = 0.00002]; and 5) experimentals also had increased rapid eye movement (REM) density during REM periods compared to short-term practitioners (p = 0.04). Previous studies have found increased theta-alpha EEG activity during reported periods of "transcendental consciousness" during the TM technique. In the Vedic tradition, as described by Maharishi Mahesh Yogi, transcendental consciousness is the first of a sequence of higher states. The maintenance of transcendental consciousness along with deep sleep is said to be a distinctive criterion of further, stabilized higher states of consciousness. The findings of this study are interpreted as physiological support for this model.

Pregnancy outcome in hyperthyroidism: a case control study.

PubMed

Aggarawal, Neelam; Suri, Vanita; Singla, Rimpi; Chopra, Seema; Sikka, Pooja; Shah, Viral N; Bhansali, Anil

2014-01-01

Data comparing pregnancy outcome in hyperthyroid women with euthyroid women are scarce. Hence, this study was carried out to assess the maternal and fetal outcome in pregnant women with hyperthyroidism to ascertain the effect of disease on pregnancy. This retrospective study was conducted over a period of 28 years. We compared the maternal and fetal outcomes of 208 hyperthyroid women with 403 healthy controls, between women with well-controlled and uncontrolled disease and amongst women diagnosed with hyperthyroidism before and during pregnancy. Maternal outcome: women with hyperthyroidism were at increased risk for preeclampsia (OR = 3.94), intrauterine growth restriction (OR = 2.16), spontaneous preterm labor (OR = 1.73), preterm birth (OR = 1.7), gestational diabetes mellitus (OR = 1.8), and cesarean delivery (OR = 1.47). Hyperthyroid women required induction of labor more frequently (OR = 3.61). Fetal outcome: newborns of hyperthyroid mothers had lower birth weight than normal ones (p = 0.0001). Women with uncontrolled disease had higher odds for still birth (OR = 8.42; 95% CI: 2.01-35.2) and lower birth weight (p = 0.0001). Obstetrical complications were higher in women with hyperthyroidism than normal women. Outcome was worsened by uncontrolled disease. Women with pregestational hyperthyroidism had better outcomes than those diagnosed with it during pregnancy. © 2014 S. Karger AG, Basel.

What is the evidence behind the evidence-base? The premature death of block-replace antithyroid drug regimens for Graves' disease.

PubMed

Razvi, Salman; Vaidya, Bijay; Perros, Petros; Pearce, Simon H S

2006-06-01

Block-replace and titration antithyroid drug regimens both give similar rates of medium- to long-term remission of hyperthyroid Graves' disease. Recent meta-analysis, however, has suggested that titration regimens may be preferable owing to a higher rate of adverse events seen in the block-replace arms of published comparative studies. This article critically re-evaluates the evidence upon which these meta-analyses were based. We suggest that there is little objective evidence that is pertinent to current clinical practice to separate block-replace from titration antithyroid drug regimens and that both remain satisfactory approaches to the medical management of hyperthyroid Graves' disease.

[ATP-synthetase activity, respiration and cytochromes of rat heart mitochondria in aging and hyperthyroidism].

PubMed

Lemeshko, V V; Kaliman, P A; Belostotskaia, L I; Uchitel', A A

1982-04-01

The ATP-synthetase activity, the rate of oxygen uptake under different metabolic conditions, the tightness of coupling of respiration to oxidative phosphorylation and the cytochrome contents in heart mitochondria of rats from different age groups were studied under normal conditions and in hyperthyroidism. It was found that heart mitochondria of aged animals did not practically differ in terms of their functional activity from those of the young animals. Administration of thyroxin to the animals from all age groups produced no significant effects on the state of mitochondria, increasing the rate of ATP synthesis on alpha-glycerophosphate, which was especially well-pronounced in aged animals, and the cytochrome content in 1-month-old rats.

Asymptomatic hyperthyroidism in older adults: is it a distinct clinical and laboratory entity?

PubMed

Mooradian, Arshag D

2008-01-01

Hyperthyroidism is the result of increased serum free thyroid hormone levels and is associated with a well recognized set of clinical signs and symptoms. However, older patients who develop hyperthyroidism tend to have fewer hyperadrenergic signs and an increased incidence of weight loss, cardiac arrhythmias and, occasionally, apathetic mood. This article highlights the paucity of clinical signs and symptoms of hyperthyroidism in older people and reviews the potential biochemical changes in thyroid hormone physiology that may account for an altered clinical presentation in older people with hyperthyroidism. First, a brief vignette from our own clinical practice is described to highlight an unusual presentation of hyperthyroidism in an older woman. The subject is then reviewed on the basis of relevant articles identified through a MEDLINE search of the English literature, using the key words 'hyperthyroidism' and 'aging'. The available evidence indicates that the clinical syndrome of asymptomatic hyperthyroidism in older adults appears to be distinct from the more widely recognized syndromes of apathetic hyperthyroidism or thyroid hormone resistance. Age-related changes in thyroid hormone economy and reduced cellular uptake of thyroid hormone as well as changes in thyroid hormone regulation of gene expression may account for reduced manifestations of hyperthyroidism in older adults. Thus, in addition to the well known changes in thyroid gland anatomy and function with aging, there may be an age-related resistance to thyroid hormone action. Asymptomatic hyperthyroidism may well be a syndrome that is currently under-diagnosed.

Pediatric Pulmonary Arterial Hypertension and Hyperthyroidism: A Potentially Fatal Combination

PubMed Central

Trapp, Christine M.; Elder, Robert W.; Gerken, Adrienne T.; Sopher, Aviva B.; Lerner, Shulamit; Rosenzweig, Erika B.

2012-01-01

Context: Patients with pulmonary arterial hypertension (PAH) who develop hyperthyroidism are at risk for acute cardiopulmonary decompensation and death. Cases and Setting: We present a series of eight idiopathic PAH/heritable PAH pediatric patients who developed hyperthyroidism between 1999 and 2011. Institutional Review Board approval was obtained; informed consent was waived due to the retrospective nature of the series. All eight patients were receiving iv epoprostenol; five of the eight patients presented with acute cardiopulmonary decompensation in the setting of hyperthyroidism. In the remaining three patients, hyperthyroidism was detected during routine screening of thyroid function tests. The one patient who underwent emergency thyroidectomy was the only survivor of those who presented in cardiopulmonary decline. Evidence Synthesis: Aggressive treatment of the hyperthyroid state, including emergency total thyroidectomy and escalation of targeted PAH therapy and β-blockade when warranted, may prove lifesaving in these patients. Prompt thyroidectomy or radioactive iodine ablation should be considered for clinically stable PAH patients with early and/or mild hyperthyroidism to avoid potentially life-threatening cardiopulmonary decompensation. Conclusions: Although the association between hyperthyroidism and PAH remains poorly understood, the potential impact of hyperthyroidism on the cardiopulmonary status of PAH patients must not be ignored. Hyperthyroidism must be identified early in this patient population to optimize intervention before acute decompensation. Thyroid function tests should be checked routinely in patients with PAH, particularly those on iv epoprostenol, and urgently in patients with acute decompensation or symptoms of hyperthyroidism. PMID:22622024

Graves hyperthyroidism and pregnancy: a clinical update.

PubMed

Patil-Sisodia, Komal; Mestman, Jorge H

2010-01-01

To provide a clinical update on Graves' hyperthyroidism and pregnancy with a focus on treatment with antithyroid drugs. We searched the English-language literature for studies published between 1929 and 2009 related to management of hyperthyroidism in pregnancy. In this review, we discuss differential diagnosis of hyperthyroidism, management, importance of early diagnosis, and importance of achieving proper control to avoid maternal and fetal complications. Diagnosing hyperthyroidism during pregnancy can be challenging because many of the signs and symptoms are similar to normal physiologic changes that occur in pregnancy. Patients with Graves disease require prompt treatment with antithyroid drugs and should undergo frequent monitoring for signs of fetal and maternal hyperthyroidism and hypothyroidism. Rates of maternal and perinatal complications are directly related to control of hyperthyroidism in the mother. Thyroid receptor antibodies should be assessed in all women with hyperthyroidism to help predict and reduce the risk of fetal or neonatal hyperthyroidism or hypothyroidism. The maternal thyroxine level should be kept in the upper third of the reference range or just above normal, using the lowest possible antithyroid drug dosage. Hyperthyroidism may recur in the postpartum period as Graves disease or postpartum thyroiditis; thus, it is prudent to evaluate thyroid function 6 weeks after delivery. Preconception counseling, a multidisciplinary approach to care, and patient education regarding potential maternal and fetal complications that can occur with different types of treatment are important. Preconception counseling and a multifaceted approach to care by the endocrinologist and the obstetric team are imperative for a successful pregnancy in women with Graves hyperthyroidism.

Pathophysiology and management of intracranial arterial stenosis around the circle of Willis associated with hyperthyroidism: case reports and literature review.

PubMed

Matano, Fumihiro; Murai, Yasuo; Adachi, Koji; Kitamura, Takayuki; Teramoto, Akira

2014-04-01

Cases of moyamoya disease or intracranial arterial stenosis around the circle of Willis (M/IAS) associated with hyperthyroidism have been reported. However, most of these previous reports were of the ischemic form of M/IAS and primary hyperthyroidism. To the best of our knowledge, no studies have documented therapy for M/IAS associated with hyperthyroidism. We discuss four previously unreported cases, including those involving the intracerebral hemorrhage form and thyroid-stimulating hormone (TSH) secretion from a pituitary adenoma (secondary hyperthyroidism). We analyzed data from 52 previously reported cases, including the 4 cases presented here, and discuss M/IAS associated with hyperthyroidism, treatment options, pathophysiology, the ischemic and hemorrhagic forms, secondary hyperthyroidism, and the relevant literature. Hyperthyroidism results in thyrotoxicosis and the stimulation of the superior cervical ganglion by TSH antibodies and f-T3/f-T4. Consequently, hypercoagulability and stenosis of the cerebral artery can occur. There are many reports of ischemic M/IAS associated with hyperthyroidism. A conservative approach to treatment is important in such cases; for example, antithyroid therapy should be the first choice to treat ischemic M/IAS. There have been only a limited number of reports on hemorrhagic M/IAS. We presume that hemorrhagic M/IAS tears the weakened vasculature in a manner similar to that of normal M/IAS (with no complicating hyperthyroidism). The authors also reported M/IAS associated with secondary hyperthyroidism due to pituitary thyroid secreting hormone secreting adenoma.

The Diagnosis and Management of Hyperthyroidism in Korea: Consensus Report of the Korean Thyroid Association

PubMed Central

Moon, Jae Hoon

2013-01-01

Hyperthyroidism is one of the causes of thyrotoxicosis and the most common cause of hyperthyroidism in Korea is Graves disease. The diagnosis and treatment of Graves disease are different according to geographical area. Recently, the American Thyroid Association and the American Association of Clinical Endocrinologists suggested new management guidelines for hyperthyroidism. However, these guidelines are different from clinical practice in Korea and are difficult to apply. Therefore, the Korean Thyroid Association (KTA) conducted a survey of KTA members regarding the diagnosis and treatment of hyperthyroidism, and reported the consensus on the management of hyperthyroidism. In this review, we summarized the KTA report on the contemporary practice patterns in the diagnosis and management of hyperthyroidism, and compared this report with guidelines from other countries. PMID:24396691

Anesthetic management of patient with myasthenia gravis and uncontrolled hyperthyroidism for thymectomy.

PubMed

Datt, Vishnu; Tempe, Deepak K; Singh, Baljit; Tomar, Akhlesh S; Banerjee, Amit; Dutta, Devesh; Bhandari, Hricha

2010-01-01

The relationship between myasthenia gravis (MG) and other autoimmune disorders like hyperthyroidism is well known. It may manifest earlier, concurrently or after the appearance of MG. The effect of treatment of hyperthyroidism on the control of MG is variable. There may be resolution or conversely, deterioration of the symptoms also. We present a patient who was diagnosed to be hyperthyroid two and half years before the appearance of myasthenic symptoms. Pharmacotherapy for three months neither improved the myasthenic symptoms nor the thyroid function tests. Thymectomy resulted in control of MG as well as hyperthyroidism. In conclusion, effective control of hyperthyroidism in the presence of MG may be difficult. The authors opine that careful peri-operative management of thymectomy is possible in a hyperthyroid state.

Hyperthyroidism and Risk for Bipolar Disorders: A Nationwide Population-Based Study

PubMed Central

Hu, Yu-Wen; Chen, Mu-Hong; Tsai, Chia-Fen; Chiang, Huey-Ling; Yeh, Chiu-Mei; Wang, Wei-Shu; Chen, Pan-Ming; Hu, Tsung-Ming; Chen, Tzeng-Ji; Su, Tung-Ping; Liu, Chia-Jen

2013-01-01

Background Thyroid disorders have long been associated with psychiatric illness, often with symptoms suggestive of mood disorders. The most common clinical features associated with hyperthyroidism are anxiety and depression. The risk of bipolar disorders, especially bipolar mania, among patients with thyroid disorders has not been well characterized. Objective We explored the relationship of hyperthyroidism and the subsequent development of bipolar disorders, and examined the risk factors for bipolar disorders in patients with hyperthyroidism. Methods We identified patients who were diagnosed with hyperthyroidism between 2000 and 2010 in the Taiwan National Health Insurance Research Database. A comparison cohort without hyperthyroidism was matched based on age, sex, and comorbidities. The occurrence of bipolar disorders was evaluated in both cohorts based on diagnosis and the use of mood stabilizer drugs. Results The hyperthyroidism cohort consisted of 21, 574 patients, and the comparison cohort consisted of 21, 574 matched control patients without hyperthyroidism. The incidence of bipolar disorders (incidence rate ratio [IRR], 2.31, 95% CI 1.80–2.99, P<.001) was higher for the hyperthyroidism patients than the control patients. Multivariate, matched regression models showed that women (HR 2.02, 95% CI 1.34–3.05, P = .001), patients with alcohol use disorders (HR 3.03, 95% CI 1.58–5.79, P = .001), and those with asthma (HR 1.70, 95% CI 1.18–2.43, P = .004) were independent risk factors for the development of bipolar disorders in hyperthyroidism patients. Conclusions Although a possibility that the diagnosis of bipolar disorders in this study actually includes "bipolar disorders due to hyperthyroidism" cannot be excluded, this study suggests that hyperthyroidism may increase the risk of developing bipolar disorders. PMID:24023669

Percentage and function of CD4+CD25+ regulatory T cells in patients with hyperthyroidism

PubMed Central

Jiang, Ting-Jun; Cao, Xue-Liang; Luan, Sha; Cui, Wan-Hui; Qiu, Si-Huang; Wang, Yi-Chao; Zhao, Chang-Jiu; Fu, Peng

2018-01-01

The current study observed the percentage of peripheral blood (PB) CD4+CD25+ regulatory T cells (Tregs) and the influence of CD4+CD25+ Tregs on the proliferation of naïve CD4 T cells in patients with hyperthyroidism. Furthermore, preliminary discussions are presented on the action mechanism of CD4+CD25+ Tregs on hyperthyroidism attacks. The present study identified that compared with the percentage of PB CD4+CD25+ Tregs in healthy control subjects, no significant changes were observed in the percentage of PB CD4+CD25+ Tregs in patients with hyperthyroidism (P>0.05). For patients with hyperthyroidism, CD4+CD25+ Tregs exhibited significantly reduced inhibition of the proliferation of naïve CD4 T cells and decreased secretion capacity on the cytokines of CD4 T cells, compared with those of healthy control subjects (P<0.05). In addition, it was demonstrated that thyroid function of patients with hyperthyroidism was significantly improved (P<0.05) subsequent to receiving medication. Compared with the percentage of PB CD4+CD25+ Tregs in patients with hyperthyroidism before treatment, no significant changes were observed in the percentage of PB CD4+CD25+ Tregs in hyperthyroidism patients following treatment (P>0.05). In the patients with hyperthyroidism, following treatment, CD4+CD25+ Tregs exhibited significantly increased inhibition of the proliferation of naïve CD4 T cells and increased secretion capacity of CD4 T cell cytokines, compared with those of the patients with hyperthyroidism prior to treatment (P<0.05). PB CD4+CD25+ Tregs function was decreased in patients with hyperthyroidism, and its non-proportional decrease may be closely associated with the occurrence and progression of hyperthyroidism. PMID:29207121

Excess Mortality in Treated and Untreated Hyperthyroidism Is Related to Cumulative Periods of Low Serum TSH.

PubMed

Lillevang-Johansen, Mads; Abrahamsen, Bo; Jørgensen, Henrik Løvendahl; Brix, Thomas Heiberg; Hegedüs, Laszlo

2017-07-01

Cumulative time-dependent excess mortality in hyperthyroid patients has been suggested. However, the effect of antithyroid treatment on mortality, especially in subclinical hyperthyroidism, remains unclarified. We investigated the association between hyperthyroidism and mortality in both treated and untreated hyperthyroid individuals. Register-based cohort study of 235,547 individuals who had at least one serum thyroid-stimulating hormone (TSH) measurement in the period 1995 to 2011 (7.3 years median follow-up). Hyperthyroidism was defined as at least two measurements of low serum TSH. Mortality rates for treated and untreated hyperthyroid subjects compared with euthyroid controls were calculated using multivariate Cox regression analyses, controlling for age, sex, and comorbidities. Cumulative periods of decreased serum TSH were analyzed as a time-dependent covariate. Hazard ratio (HR) for mortality was increased in untreated [1.23; 95% confidence interval (CI), 1.12 to 1.37; P < 0.001], but not in treated, hyperthyroid patients. When including cumulative periods of TSH in the Cox regression analyses, HR for mortality per every 6 months of decreased TSH was 1.11 (95% CI, 1.09 to 1.13; P < 0.0001) in untreated hyperthyroid patients (n = 1137) and 1.13 (95% CI, 1.11 to 1.15; P < 0.0001) in treated patients (n = 1656). This corresponds to a 184% and 239% increase in mortality after 5 years of decreased TSH in untreated and treated hyperthyroidism, respectively. Mortality is increased in hyperthyroidism. Cumulative periods of decreased TSH increased mortality in both treated and untreated hyperthyroidism, implying that excess mortality may not be driven by lack of therapy, but rather inability to keep patients euthyroid. Meticulous follow-up during treatment to maintain biochemical euthyroidism may be warranted. Copyright © 2017 by the Endocrine Society

Hyperthyroidism and risk for bipolar disorders: a nationwide population-based study.

PubMed

Hu, Li-Yu; Shen, Cheng-Che; Hu, Yu-Wen; Chen, Mu-Hong; Tsai, Chia-Fen; Chiang, Huey-Ling; Yeh, Chiu-Mei; Wang, Wei-Shu; Chen, Pan-Ming; Hu, Tsung-Ming; Chen, Tzeng-Ji; Su, Tung-Ping; Liu, Chia-Jen

2013-01-01

Thyroid disorders have long been associated with psychiatric illness, often with symptoms suggestive of mood disorders. The most common clinical features associated with hyperthyroidism are anxiety and depression. The risk of bipolar disorders, especially bipolar mania, among patients with thyroid disorders has not been well characterized. We explored the relationship of hyperthyroidism and the subsequent development of bipolar disorders, and examined the risk factors for bipolar disorders in patients with hyperthyroidism. We identified patients who were diagnosed with hyperthyroidism between 2000 and 2010 in the Taiwan National Health Insurance Research Database. A comparison cohort without hyperthyroidism was matched based on age, sex, and comorbidities. The occurrence of bipolar disorders was evaluated in both cohorts based on diagnosis and the use of mood stabilizer drugs. The hyperthyroidism cohort consisted of 21, 574 patients, and the comparison cohort consisted of 21, 574 matched control patients without hyperthyroidism. The incidence of bipolar disorders (incidence rate ratio [IRR], 2.31, 95% CI 1.80-2.99, P<.001) was higher for the hyperthyroidism patients than the control patients. Multivariate, matched regression models showed that women (HR 2.02, 95% CI 1.34-3.05, P = .001), patients with alcohol use disorders (HR 3.03, 95% CI 1.58-5.79, P = .001), and those with asthma (HR 1.70, 95% CI 1.18-2.43, P = .004) were independent risk factors for the development of bipolar disorders in hyperthyroidism patients. Although a possibility that the diagnosis of bipolar disorders in this study actually includes "bipolar disorders due to hyperthyroidism" cannot be excluded, this study suggests that hyperthyroidism may increase the risk of developing bipolar disorders.

Serum thyrotrophin at baseline predicts the natural course of subclinical hyperthyroidism.

PubMed

Das, G; Ojewuyi, T A; Baglioni, P; Geen, J; Premawardhana, L D; Okosieme, O E

2012-07-01

Optimal therapeutic strategies for subclinical hyperthyroidism are undecided. Overt disease develops in a minority of cases, but the risk factors for progression remain unclear. We examined whether a baseline thyrotrophin (TSH) predicted progression to overt hyperthyroidism in asymptomatic individuals with subclinical hyperthyroidism. This was a retrospective study of 323 patients with subclinical hyperthyroidism seen in our institution from 2003 to 2010 (mean age 71 years, males 26·9%, females 73·1%, mean follow-up duration 32 months, range 6-93 months). Serum TSH and free thyroxine (FT4) were documented at baseline and during follow-up. After excluding individuals with nonthyroid causes of low TSH, patients were grouped according to initial TSH as: TSH 0·10-0·39 mU/l (grade I) and TSH < 0·10 mU/l (grade II). Only 38 patients (11·8%) developed overt hyperthyroidism with annual progression rates of 0·6-3·7%. Most patients reverted to normal thyroid status (31·6%) or remained subclinically hyperthyroid (56·7%). Progression to frank hyperthyroidism was higher in grade II than in grade I patients (20·3% vs 6·8%, P < 0·001, Chi square test). Kaplan-Meier curves showed faster progression rates in grade II than grade I (P < 0·001, log rank test). In stepwise multivariate Cox regression analysis, TSH < 0·1 mU/l was associated with overt hyperthyroidism (hazard ratio 3·4, confidence interval 1·6-7·0), whereas age, gender, FT4 and aetiological diagnosis were not associated with hyperthyroidism. Thyrotrophin predicts overt hyperthyroidism in asymptomatic individuals with subclinical hyperthyroidism. Patients with TSH < 0·10 mU/l have a higher risk of progressing to hyperthyroidism than those with TSH 0·10-0·39 mU/l. © 2012 Blackwell Publishing Ltd.

Thyroid hormone regulates the expression of the sonic hedgehog signaling pathway in the embryonic and adult Mammalian brain.

PubMed

Desouza, Lynette A; Sathanoori, Malini; Kapoor, Richa; Rajadhyaksha, Neha; Gonzalez, Luis E; Kottmann, Andreas H; Tole, Shubha; Vaidya, Vidita A

2011-05-01

Thyroid hormone is important for development and plasticity in the immature and adult mammalian brain. Several thyroid hormone-responsive genes are regulated during specific developmental time windows, with relatively few influenced across the lifespan. We provide novel evidence that thyroid hormone regulates expression of the key developmental morphogen sonic hedgehog (Shh), and its coreceptors patched (Ptc) and smoothened (Smo), in the early embryonic and adult forebrain. Maternal hypo- and hyperthyroidism bidirectionally influenced Shh mRNA in embryonic forebrain signaling centers at stages before fetal thyroid hormone synthesis. Further, Smo and Ptc expression were significantly decreased in the forebrain of embryos derived from hypothyroid dams. Adult-onset thyroid hormone perturbations also regulated expression of the Shh pathway bidirectionally, with a significant induction of Shh, Ptc, and Smo after hyperthyroidism and a decline in Smo expression in the hypothyroid brain. Short-term T₃ administration resulted in a significant induction of cortical Shh mRNA expression and also enhanced reporter gene expression in Shh(+/LacZ) mice. Further, acute T₃ treatment of cortical neuronal cultures resulted in a rapid and significant increase in Shh mRNA, suggesting direct effects. Chromatin immunoprecipitation assays performed on adult neocortex indicated enhanced histone acetylation at the Shh promoter after acute T₃ administration, providing further support that Shh is a thyroid hormone-responsive gene. Our results indicate that maternal and adult-onset perturbations of euthyroid status cause robust and region-specific changes in the Shh pathway in the embryonic and adult forebrain, implicating Shh as a possible mechanistic link for specific neurodevelopmental effects of thyroid hormone.

Neonatal hyperthyroidism impairs epinephrine-provoked secretion of nerve growth factor and epidermal growth factor in mouse saliva.

PubMed

Lakshmanan, J; Landel, C P

1986-07-01

We examined long-term effects of neonatal hyperthyroidism on salivary secretions of nerve growth factor and epidermal growth factor in male and female mice at the age of 31 days. Hyperthyroidism was induced by thyroxine (T4) injections (0.4 microgram/g body weight/day) during days 0-6. Littermate control mice were treated with vehicle. T4 treatment did not alter the amounts of protein secreted into saliva but hormone administration induced alteration in the types of protein secreted. T4 treatment decreased the contents of both nerve growth factor and epidermal growth factor secreted into the saliva. A Sephadex G-200 column chromatographic profile revealed the presence of two distinct nerve growth factor immunoreactive peaks, while epidermal growth factor immunoreactivity predominantly eluted as a single low molecular weight form. T4 treatment did not alter the molecular nature of their secretion, but the treatment decreased their contents. These results indicate an impairment in salivary secretion of nerve growth factor and epidermal growth factor long after T4 treatment has been discontinued.

A simple test of one minute heart rate variability during deep breathing for evaluation of sympatovagal imbalance in hyperthyroidism.

PubMed

Shuvy, Mony; Arbelle, Jonathan E; Grosbard, Aviva; Katz, Amos

2008-01-01

Heart rate variability is a sensitive marker of cardiac sympathetic activity. To determine whether long-term hyperthyroidism induced by thyroxine suppressive therapy affects HRV. Nineteen patients treated with suppressive doses of thyroxin for thyroid cancer and 19 age-matched controls were enrolled. Thyroid function tests and 1 minute HRV were performed on all subjects and the results were compared between the groups. The 1 minute HRV was analyzed during deep breathing and defined as the difference in beats/minute between the shortest and the longest heart rate interval measured by eletrocardiographic recording during six cycles of deep breathing. One minute HRV during deep breathing was significantly lower among thyroxine-treated patients compared to healthy controls (25.6 +/- 10.5 vs. 34.3 +/- 12.6 beats/min, P < 0.05). There were no significant differences in mean, maximal and minimal heart rate between the groups. Thyroxine therapy administered for epithelial thyroid cancer resulted in subclinical hyperthyroidism and significantly decreased HRV due to autonomic dysfunction rather than basic elevated heart rate.

Unstable angina with normal coronary angiography in hyperthyroidism: a case report.

PubMed

Lin, Tsung-Hsien; Su, Ho-Ming; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung

2005-01-01

Hyperthyroidism is associated with an increase in myocardial oxygen consumption that, due to an imbalance of oxygen demand and supply, can cause angina. However, subclinical hyperthyroidism rarely presents as chest pain in the resting state. Herein, we present a case of subclinical hyperthyroidism involving a 58-year-old male who complained of frequent chest tightness and typical electrocardiographic changes while in a resting state. Coronary angiography showed no significant lesion. Laboratory data showed that the patient suffered from hyperthyroidism, for which he was successfully treated with anti-thyroid agents. We are reminded that typical chest pain might be the first symptom of hyperthyroidism.

Pitting type of pretibial edema in a patient with silent thyroiditis successfully treated by angiotensin ii receptor blockade.

PubMed

Kazama, Itsuro; Mori, Yoko; Baba, Asuka; Nakajima, Toshiyuki

2014-01-01

Female, 56 FINAL DIAGNOSIS: Thyroiditis - silent Symptoms: Palpitations • pretibial pitting edema • short of breath • sweating - Clinical Procedure: - Specialty: Endocrinology and Metabolic. Unknown etiology. Hyper- or hypothyroidism sometimes causes pretibial myxedema characterized by non-pitting infiltration of a proteinaceous ground substance. However, in those patients, the "pitting" type of pretibial edema as a result of increased sodium and fluid retention or vascular hyper-permeability rarely occurs, except in cases complicated by heart failures due to severe cardiomyopathy or pulmonary hypertension. A 56-year-old woman developed bilateral pretibial pitting edema, followed by occasional sweating, palpitations, and shortness of breath, which persisted for more than 2 months. The diagnosis of hyperthyroidism due to silent thyroiditis was supported by elevated levels of free thyroxine (T4) and triiodothyronine (T3), with a marked decrease in thyroid-stimulating hormone (TSH), and the negative results for TSH receptor antibodies with typical findings of destructive thyrotoxicosis. Despite her "pitting" type of pretibial edema, a chest radio-graph demonstrated the absence of cardiomyopathy or congestive heart failure. Oral administration of angiotensin II receptor blocker (ARB) was initiated for her systolic hypertension, with a relatively higher elevation of plasma renin activity compared to that of the aldosterone level. Although the symptoms characteristic to hyperthyroidism, such as increased sweating, palpitations and shortness of breath, slowly improved with a spontaneous resolution of the disease, ARB quickly resolved the pretibial pitting edema shortly after the administration.. In this case, increased activity of the renin-angiotensin-aldosterone system stimulated by thyroid hormone was likely responsible for the patient's pitting type of edema. The pharmacological blockade of the renin-angiotensin-aldosterone system was thought to be effective for the quick resolution of the symptom.

A new experimental method for the accelerated characterization of composite materials

NASA Technical Reports Server (NTRS)

Brinson, H. F.; Morris, D. H.; Yeow, Y. T.

1978-01-01

A method which permits the prediction of long-term properties of graphite/epoxy laminates on the basis of short-term (15 min) laboratory tests is described. Demonstration of delayed viscoelastic fracture in one laminate configuration, and data on the time and temperature response of a matrix-dominated unidirectional laminate contributed to a characterization of the viscoelastic process in the graphite/epoxy composites. Master curves from short-term tests of certain laminate configurations can be employed to generate long-term master curves. In addition, analytical predictions from short-term results can be used to predict long-term (25-hour) laminate properties.

Hyperthyroidism in pregnancy.

PubMed

Cooper, David S; Laurberg, Peter

2013-11-01

Changes in thyroid hormone concentrations that are characteristic of hyperthyroidism must be distinguished from physiological changes in thyroid hormone economy that occur in pregnancy, especially in the first trimester. Approximately one to two cases of gestational hyperthyroidism occur per 1000 pregnancies. Identification of hyperthyroidism in a pregnant woman is important because adverse outcomes can occur in both the mother and the offspring. Graves' disease, which is autoimmune in nature, is the usual cause; but hyperthyroidism in pregnancy can be caused by any type of hyperthyroidism--eg, toxic multinodular goitre or solitary autonomously functioning nodule. Gestational transient thyrotoxicosis is typically reported in women with hyperemesis gravidarum, and is mediated by high circulating concentrations of human chorionic gonadotropin. Post-partum thyroiditis occurs in 5-10% of women, and many of those affected ultimately develop permanent hypothyroidism. Antithyroid drug treatment of hyperthyroidism in pregnant women is controversial because the usual drugs--methimazole or carbimazole--are occasionally teratogenic; and the alternative--propylthiouracil--can be hepatotoxic. Fetal hyperthyroidism can be life-threatening, and needs to be recognised as soon as possible so that treatment of the fetus with antithyroid drugs via the mother can be initiated. In this Review, we discuss physiological and pathophysiological changes in thyroid hormone economy in pregnancy, the diagnosis and management of hyperthyroidism during pregnancy, severe life-threatening thyrotoxicosis in pregnancy, neonatal thyrotoxicosis, and post-partum hyperthyroidism. Copyright © 2013 Elsevier Ltd. All rights reserved.

Psychiatric manifestations of Graves' hyperthyroidism: pathophysiology and treatment options.

PubMed

Bunevicius, Robertas; Prange, Arthur J

2006-01-01

Graves' disease is an autoimmune disorder that is the most common cause of hyperthyroidism. Other symptoms associated with the disease are goitre, ophthalmopathy, and psychiatric manifestations such as mood and anxiety disorders and, sometimes, cognitive dysfunction. Graves' hyperthyroidism may result in these latter manifestations via the induction of hyperactivity of the adrenergic nervous system. This review addresses the psychiatric presentations, and their pathophysiology and treatment, in patients with hyperthyroidism, based on literature identified by a PubMed/MEDLINE database search. Although the focus is on mental symptoms associated with Graves' disease, it is not always clear from the literature whether patients had Graves' disease: in some studies, the patients were thought to have Graves' disease based on clinical findings such as diffuse goitre or ophthalmopathy or on measurements of thyroid antibodies in serum; however, in other studies, no distinction was made between Graves' hyperthyroidism and hyperthyroidism from other causes. Antithyroid drugs combined with beta-adrenoceptor antagonists are the treatments of choice for hyperthyroidism, as well as for the psychiatric disorders and mental symptoms caused by hyperthyroidism. A substantial proportion of patients have an altered mental state even after successful treatment of hyperthyroidism, suggesting that mechanisms other than hyperthyroidism, including the Graves' autoimmune process per se and ophthalmopathy, may also be involved. When psychiatric disorders remain after restoration of euthyroidism and after treatment with beta-adrenoceptor antagonists, specific treatment for the psychiatric symptoms, especially psychotropic drugs, may be needed.

Hyperthyroidism and erectile dysfunction: a population-based case-control study.

PubMed

Keller, J; Chen, Y-K; Lin, H-C

2012-01-01

Dysthyroidism has been highlighted as a common endocrine disorder associated with erectile dysfunction (ED); however, to date, no large-scale population-based study has investigated the association between hyperthyroidism and ED. This case-control study aimed to explore the association between ED and hyperthyroidism using a population-based data set. In total, 6310 adult patients who received new diagnoses of ED were recruited as cases together with 18 930 matched enrollees with no history of ED who served as controls. Conditional logistic regressions were conducted to explore the association between ED and having been previously diagnosed with hyperthyroidism. In total, 569 (2.3%) of the 25 240 sampled subjects had been diagnosed with hyperthyroidism before the index date; hyperthyroidism was found in 207 (3.3%) cases and 362 (1.90%) controls. After adjusting for potential confounding factors, the odds ratio (OR) of prior hyperthyroidism among cases was 1.64 (95% confidence interval=1.37-1.96, P<0.001) than that of controls. No association was detected between prior hyperthyroidism and ED for the 18-30, 30-39 and >70 age groups. Subjects aged between 60 and 69 years had the highest ORs for prior hyperthyroidism among cases when compared to controls (OR=1.84; 95% confidence interval=1.20-2.84; P<0.001). Our study further confirms the existence of an association between ED and prior hyperthyroidism.

[Thyroid diseases in old age. Clinical aspects and therapy. Part 1: Hyperthyroidism].

PubMed

Rudorff, K H; Fahrenkrog, U; Jahnke, K

1981-08-27

The clinical signs of thyroid disease in older people may differ considerably from those in younger patients. The symptoms are often incorrectly interpreted and attributed to old age. The age is also important to the kind of therapy. The normal clinical hyperthyroidism-indices are not relevant in the diagnosis of hyperthyroidism in older patients. Organic symptoms predominate in old age (loss of weight, muscular asthenia, tremor, cardiac arrhythmia, stenocardia, congestive cardiomyopathy). Most of the time they are wrongly interpreted as additional symptoms of old age. Probably it is not the age that causes the difficulties in hyperthyroidism-diagnostics in old age, but the atypical symptoms of solitary or multilocular adenomas, which increase with advancing age. A special symptom of hyperthyroidism in old age, often misinterpreted, is "apathetic" hyperthyroidism. Radioiodotherapy is indicated in older patients with hyperthyroidism.

Survival times for cats with hyperthyroidism treated with a 3.35 mCi iodine-131 dose: a retrospective study of 96 cases.

PubMed

Vagney, Marie; Desquilbet, Loic; Reyes-Gomez, Edouard; Delisle, Françoise; Devauchelle, Patrick; Rodriguez-Piñeiro, Maria Isabel; Rosenberg, Dan; de Fornel-Thibaud, Pauline

2018-06-01

Objectives Radioiodine ( 131 I) dose determination using radiotracer kinetic studies or scoring systems, and fixed relatively high 131 I dose (ie, 4 or 5 mCi) administration, are effective and associated with prolonged survival times for hyperthyroid cats. The latter method is less complicated but could expose patients and veterinary personnel to unnecessary levels of radiation. The aim of this study was to retrospectively evaluate the efficacy of a fixed 3.35 mCi 131 I dose for the treatment of 96 hyperthyroid cats with no length estimation for any palpated goitre ⩾20 mm, assess outcome and identify factors associated with survival. Methods Serum total thyroxine concentrations at diagnosis and at follow-up times, survival times and cause of death were recorded. Multivariable Cox regression analysis was used to identify factors associated with time to any cause of death from 131 I therapy initiation. Results Administration of a median (interquartile range) dose of 3.35 mCi (3.27-3.44 mCi) radioiodine was an effective treatment in 94/96 cats, but two cats remained hyperthyroid. No death related to hyperthyroidism was recorded. Median survival time was 3.0 years; the 1 and 2 year survival rates after 131 I therapy were 90% and 78%, respectively. Low body weight (⩽3.1 kg; adjusted hazard ratio [aHR] 5.88; 95% confidence interval [CI] 2.22-16.67; P <0.01) and male gender (aHR 2.63; 95% CI 1.01-7.14; P = 0.04) were independently associated with death, whereas age, prior treatment with antithyroid drugs, reason for treatment and pretreatment azotaemia were not. Conclusions and relevance This study suggests that a fixed 3.35 mCi 131 I dose treatment is effective for hyperthyroid cats with goitre(s) with a maximal length estimation <20 mm, that long-term survival can be achieved and that low body weight and male gender are significantly associated with shorter survival times.

Platysmal myoclonus in subclinical hyperthyroidism.

PubMed

Teoh, Hock-Luen; Lim, Erle Chuen-Hian

2005-08-01

Hyperthyroidism is associated with various movement disorders, such as chorea and tremors. We report on a young Chinese woman with an unusual presentation of myoclonus, involving both platysmal muscles, in association with subclinical hyperthyroidism. The myoclonus was preceded by symptoms of hyperthyroidism, namely weight loss, menstrual disturbances, and heat intolerance. The movements abated with clonazepam and hyperthyroidism was treated with carbimazole. The myoclonus recurred briefly when she stopped taking clonazepam, but she has since remained well and euthyroid. Copyright 2005 Movement Disorder Society

Hyperthyroidism and Jaundice

PubMed Central

Bal, CS; Chawla, Madhavi

2010-01-01

Development of hyperbilirubinemia, concurrent or subsequent to hyperthyroidism, can be due to thyrotoxicosis per se, or due to drug treatment of hyperthyroidism. Other rare conditions: autoimmune thyroid disease, or causes unrelated to hyperthyroidism like viral hepatitis, alcohol abuse, sepsis, cholangitis, or as a side effect of certain medications. In this article, we review these causes of co-existent hyperthyroidism and jaundice. We also highlight the changes to be expected while interpreting thyroid function tests vis-a-vis liver function tests in this subgroup of patients. PMID:21713219

Atrial fibrillation associated with subclinical hyperthyroidism.

PubMed

Patanè, Salvatore; Marte, Filippo

2009-05-29

Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with coronary heart disease or mortality from cardiovascular causes but it is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. It has also been reported that increased factor X activity in patients with subclinical hyperthyroidism represents a potential hypercoagulable state. We present a case of atrial fibrillation associated with subclinical hyperthyroidism, in a 78-year-old Italian woman. Also this case focuses attention on the importance of a correct evaluation of subclinical hyperthyroidism.

A new experimental method for the accelerated characterization of composite materials

NASA Technical Reports Server (NTRS)

Yeow, Y. T.; Morris, D. H.; Brinson, H. F.

1978-01-01

The use of composite materials for a variety of practical structural applications is presented and the need for an accelerated characterization procedure is assessed. A new experimental and analytical method is presented which allows the prediction of long term properties from short term tests. Some preliminary experimental results are presented.

Plasma levels of coenzyme Q10 in children with hyperthyroidism.

PubMed

Menke, Thomas; Niklowitz, Petra; Reinehr, Thomas; de Sousa, Gideon John; Andler, Werner

2004-01-01

In hyperthyroidism, increased oxygen consumption and free radical production in the stimulated respiratory chain leads to oxidative stress. Apart from its antioxidative function, coenzyme Q10 (CoQ10) is involved in electron transport in the respiratory chain. The aim of this study was to determine whether there is a correlation between an increased respiratory chain activity and the state of CoQ10 in children with hyperthyroidism. The CoQ10 plasma concentration was measured by high-performance liquid chromatography in 12 children with hyperthyroidism before and after treatment. In the hyperthyroid state, the plasma level of CoQ10 was significantly decreased in comparison with the level in the euthyroid state. The correction of the hyperthyroid state resulted in a normalization of the CoQ10 level. Plasma CoQ10 deficiency appears to be related to the stimulated respiratory chain activity in children with hyperthyroidism. Copyright 2004 S. Karger AG, Basel

Impairment of attention networks in patients with untreated hyperthyroidism.

PubMed

Yuan, Lili; Tian, Yanghua; Zhang, Fangfang; Dai, Fang; Luo, Li; Fan, Jin; Wang, Kai

2014-06-27

Attention disorders are common symptoms in patients with untreated hyperthyroidism. Nevertheless, it is unknown whether they represent a global attention deficit or selective impairment of attention networks. Thirty-seven patients with hyperthyroidism were recruited and underwent the Attention Network Test (ANT), which provided measures of three independent attention networks (alerting, orienting and executive control), before being treated with methimazole. This study demonstrated that patients with untreated hyperthyroidism had significant deficits in the alerting and executive control networks. Interestingly, a significant positive association was also found between T4 level and the value of the executive network in patients with hyperthyroidism. These results suggest that the patients with hyperthyroidism may not just exist a specific impairment of attention networks, and there was some relationship between the level of T4, not T3 or TSH, and the value of the executive control network in patients with hyperthyroidism. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Pancytopenia in a surgical patient, a rare presentation of hyperthyroidism.

PubMed

Jha, Prabhat; Singh, Yogendra Prasad; Ghimire, Bikal; Jha, Binit Kumar

2014-12-15

Pancytopenia is a rare complication of hyperthyroidism. Various mechanisms have been described such as immunological, bone marrow suppression. The possibility of hyperthyroidism should be considered in patients with unexplained pancytopenia. There are many case reports showing the association between hyperthyroidism and pancytopenia. All of these reports show association between Graves disease and pancytopenia but our case shows association between Multinodular goitre and pancytopenia. Besides it is uncommon to find such association in a surgical patient. This case report describes a 62 yr old hindu female with splenic injury and pancytopenia. On further investigations the patient was found to have hyperthyroidism. Though the definite mechanism regarding the association of pancytopenia with hyperthyroidism isn't clear, various cases have been described in the literature. This case shows the diagnostic dilemma that can occur in patients with pancytopenia. Any patient with unexplained pancytopenia should undergo thyroid function tests to rule out hyperthyroidism.

Atrial fibrillation and acute myocardial infarction without significant coronary stenoses associated with subclinical hyperthyroidism and erythrocytosis.

PubMed

Patanè, Salvatore; Marte, Filippo

2010-11-05

Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that sub-clinical hyperthyroidism is not associated with CHD or mortality from cardiovascular causes but is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. Moreover increased factor X activity in patients with subclinical hyperthyroidism represents a potential hypercoagulable state. It has been also reported an acute myocardial infarction with normal coronary arteries associated with iatrogenic hyperthyroidism and with a myocardial bridge too. It has been also reported an acute myocardial infarction without significant coronary stenoses associated with subclinical hyperthyroidism. Furthermore it has been reported that at highly increased hematocrit levels patients may experience hyperviscosity symptoms. We present a case of atrial fibrillation and acute myocardial infarction without significant coronary stenoses associated with subclinical hyperthyroidism and erythrocytosis. Also this case focuses attention on the importance of a correct evaluation of subclinical hyperthyroidism. Copyright © 2008 Elsevier Ireland Ltd. All rights reserved.

Diagnosis and Management of Hyperthyroidism in Pregnancy: A Review.

PubMed

King, Jennifer Renae; Lachica, Ruben; Lee, Richard H; Montoro, Martin; Mestman, Jorge

2016-11-01

Hyperthyroidism has important implications for pregnancy, affecting both mother and fetus. Appropriate maternal and fetal management iscritical to avoiding adverse pregnancy outcomes and requires a multidisciplinary approach. To describe maternal diagnosis and management of hyperthyroidism, across all stages of pregnancy. In addition, to review clinical signs of fetal thyroid dysfunction due to maternal Graves disease and discuss management considerations. Review of published articles on PubMed and guidelines by recognized governing organizations regarding the diagnostic and management considerations for hyperthyroidism in pregnancy, from preconception to the postpartum period. Diagnosis of maternal hyperthyroidism involves both clinical symptoms and laboratory findings. Antithyroid medications are the mainstay of therapy, with trimester-specific pregnancy goals. Hyperthyroidism due to Graves disease has important diagnostic and management considerations for the fetus and neonate. Hyperthyroidism in pregnancy affects mother, fetus, and neonate. Interpretation of thyroid tests and understanding the appropriate use of antithyroid drugs are fundamental. Proper education of physicians providing care to women with hyperthyroidism is essential and starts before pregnancy. Postpartum follow-up is an essential part of the care. A systematic approach to management will ensure optimal pregnancy outcomes.

Abnormal spontaneous brain activity is associated with impaired emotion and cognition in hyperthyroidism: A rs-fMRI study.

PubMed

Zhi, Mengmeng; Hou, Zhenghua; We, Qiong; Zhang, Yuqun; Li, Ling; Yuan, Yonggui

2018-06-07

Hyperthyroid patients undergo emotional and cognitive dysfunction. However, the neurological basis for it remains ambiguous. Amplitude of low frequency fluctuation (ALFF) and regional homogeneity (ReHo) were used to investigate abnormal spontaneous activity in hyperthyroidism for the first time. 29 hyperthyroid patients and 29 healthy controls (HC) received 3.0T magnetic resonance imaging (MRI) scans and neuropsychological assessments. Compared with HC, hyperthyroid patients showed decreased ALFF in left medial frontal gyrus (MeFG) and left posterior cingulate cortex (PCC). Hyperthyroidism group exhibited decreased ReHo in left MeFG. Within hyperthyroidism group, ALFF values in left MeFG were positively correlated with Hamilton Anxiety Rating Scale (HARS) Z-scores, but negatively correlated with processing speed Z-scores. Besides, ALFF values in left precuneus had a positive correlation with HARS Z-scores. As a result, abnormal brain spontaneous activity mainly in default mode network (DMN) implicated the neuro-pathological substrate of relevant emotional and cognitive dysfunction in hyperthyroid patients. Copyright © 2018 Elsevier B.V. All rights reserved.

Hyperthyroidism-associated hypercalcemic crisis: A case report and review of the literature.

PubMed

Chen, Ke; Xie, Yanhong; Zhao, Liling; Mo, Zhaohui

2017-01-01

Hyperthyroidism is one of the major clinical causes of hypercalcaemia, however, hyperthyroidism-related hypercalcemic crisis is rare, only 1 case have been reported. The potential mechanisms are still not too clear. It may be related that thyroid hormone stimulate bone turnover, elevate serum calcium, increase urinary and fecal calcium excretion. A 58-year-old female patient was found to have Graves' disease, a marked elevated serum calcium level (adjusted serum calcium: 3.74 mmol/L), and reduced parathyroid hormone level. She was diagnosed as hyperthyroidism-associated hypercalcemic crisis. Treatment with methimazole to correct the hyperthyroidism and treatment of the patient's hypercalcaemia was achieved by physiological saline, salmon calcitonin and furosemide. After treatment for hypercalcaemia and hyperthyroidism, her symptoms and serum calcium levels quickly returned to normal. hyperthyroid-associated hypercalcaemia crisis is rare, however, the diagnosis should pay attention to screening for other diseases caused by hypercalcemia. Timely treatment of hypercalcaemia is a critical step for rapidly control of symptoms, and treatment of hyperthyroidism is beneficial to relief the symptoms and maintain the blood calcium level.

Possible association between hyperthyroidism in pregnant women and obstructive congenital abnormalities of urinary tract in their offspring--a population-based case-control study.

PubMed

Bánhidy, Ferenc; Puhó, Erzsébet H; Czeizel, Andrew E

2011-02-01

The teratogenic potential of some antithyroid drugs is known, but the aim of the study was to estimate the risk of congenital abnormalities (CAs) in the offspring of pregnant women with hyperthyroidism with or without antithyroid drug treatment. Comparison of the occurrence of medically recorded hyperthyroidism who had malformed fetuses/newborns (cases) and who delivered healthy babies (controls) in the population-based Hungarian Case-Control Surveillance System of CAs, 1980-1996. Of 22,843 cases with congenital abnormalities, 71 (0.31%) while of 38,151 controls, 116 (0.30%) had mothers with hyperthyroidism. The rate of hyperthyroidism in the mothers of cases with different CAs and in the mothers of matched controls was compared. Preeclampsia-eclampsia occurred more frequently in pregnant women with hyperthyroidism without antithyroid treatment. The analysis of specific groups of CAs showed an association between hyperthyroidism in pregnant women and obstructive defects of urinary tract in their children. The lack of appropriate treatment of pregnant women affected with hyperthyroidism seems to be the major problem, because it would be necessary to prevent the hyperthyroidism related risks of pregnancy complications and CAs which exceed the risk of antithyroid medication in these pregnant women.

Male sex, African American race or ethnicity, and triiodothyronine levels at diagnosis predict weight gain after antithyroid medication and radioiodine therapy for hyperthyroidism.

PubMed

Ariza, Miguel A; Loken, Won Mee J; Pearce, Elizabeth N; Safer, Joshua D

2010-01-01

To determine whether racial or ethnic differences affect weight gain after treatment of hyperthyroidism and to reassess established risk factors such as sex, age, and cause of hyperthyroidism. We conducted a retrospective review of medical records of 111 patients treated with radioiodine (RAI) for hyperthyroidism, with or without preceding antithyroid medication, during 2002 to 2005. We ascertained age, sex, race or ethnicity, insurance status, compliance with visits, serum triiodothyronine (T3) level at diagnosis, and cause of hyperthyroidism. Weights and serum thyroidstimulating hormone levels were obtained at diagnosis, at time of RAI therapy, and at 0 to 4 months, 4 to 8 months, 8 to 12 months, and 24 months after RAI treatment. There was a significant weight increase after treatment of hyperthyroidism. Levels of T3 at initial diagnosis of hyperthyroidism, male sex, and black or Hispanic ethnicity were found to be independent predictors of weight gain after RAI treatment. We found a significant interaction between race or ethnicity and sex in multivariate models. There was no difference in thyroid function across racial or ethnic groups or the sexes. Age, cause of hyperthyroidism, posttreatment thyroid-stimulating hormone level, compliance, and insurance status were not found to be significant predictors of weight gain. The T3 level at the time of diagnosis of hyperthyroidism is a strong predictor of weight gain after treatment of hyperthyroidism. Black race or ethnicity and male sex are also risk factors for weight gain.

A comparative study of bone mineral density between premenopausal women with hyperthyroidism and healthy premenopausal women.

PubMed

Boonya-Ussadorn, Trirat; Punkaew, Boondharika; Sriassawaamorn, Narongchai

2010-11-01

To compare bone mineral density (BMD) of the lumbar spine (L1-L4), total hip (TH), and femoral neck (FN) analyzed by Dual Energy X-ray Absorptiometry (DXA) in premenopausal women with hyperthyroidism and in healthy premenopausal women. Cross-sectional study included 49 premenopausal women with hyperthyroidism and 49 healthy premenopausal women. Age, weight and body mass index (BMI) were comparable in both groups. All subjects had a BMD measurement by DXA in the region of L1-L4, TH and FN and the unpaired t-test was used to analyze. The mean BMD of premenopausal women with hyperthyroidism at L1-L4, TH and FN was 0.928, 0.838 and 0.774 g/cm2, which were lower than those of healthy premenopausal women; 0.991, 0.917 and 0.832 g/cm2 respectively (p-value is less than 0.05). Time interval that had elapsed for active hyperthyroidism was not associated with the decrease of BMD at L1-L4, TH and FN in hyperthyroid women. The BMD of L1-L4, TH and FN in premenopausal women with hyperthyroidism were significantly lower than those of healthy premenopausal women. Therefore, overt hyperthyroidism could be associated with bone loss and may be a risk factor for the development of osteoporosis. However, time interval of active hyperthyroidism was not related to the decrease of BMD in hyperthyroid women.

Accuracy of increased thyroid activity during pertechnetate scintigraphy by subcutaneous injection for diagnosing hyperthyroidism in cats.

PubMed

Page, Richard B; Scrivani, Peter V; Dykes, Nathan L; Erb, Hollis N; Hobbs, Jeff M

2006-01-01

Our purpose was to determine the accuracy of increased thyroid activity for diagnosing hyperthyroidism in cats suspected of having that disease during pertechnetate scintigraphy using subcutaneous rather than intravenous radioisotope administration. Increased thyroid activity was determined by two methods: the thyroid:salivary ratio (T:S) and visual inspection. These assessments were made on the ventral scintigram of the head and neck. Scintigraphy was performed by injecting sodium pertechnetate (111 MBq, SQ) in the right-dorsal-lumbar region; static-acquisition images were obtained 20 min after injection. We used 49 cats; 34 (69%) had hyperthyroidism based on serum-chemistry analysis. Using a Wilcoxon's rank-sum test, a significant difference (P < 0.0001) was detected in the T:S between cats with and without hyperthyroidism. Using a decision criterion of 2.0 for the T:S, the test accurately predicted hyperthyroidism in 32/34 cats (sensitivity, 94%; 95% confidence interval (CI), 85-100%) and correctly predicted that hyperthyroidism was absent in 15/15 cats (specificity, 100%; CI, 97-100%). Using visual inspection, the test accurately predicted hyperthyroidism in 34/34 cats (sensitivity, 100%; CI, 99-100%) and correctly predicted that hyperthyroidism was absent in 12/15 cats (specificity, 80%; CI, 56-100%). The positive and negative predictive values were high for a wide range of prevalence of hyperthyroidism. And, the test had excellent agreement within and between examiners. Therefore, detecting increased thyroid activity during pertechnetate scintigraphy by subcutaneous injection is an accurate and reproducible test for feline hyperthyroidism.

Genetics and phenomics of inherited and sporadic non-autoimmune hyperthyroidism.

PubMed

Gozu, Hulya Iliksu; Lublinghoff, Julia; Bircan, Rifat; Paschke, Ralf

2010-06-30

TSH receptor (TSHR) germline mutations occur as activating mutations in familial non-autoimmune hyperthyroidism (FNAH) or sporadic non-autoimmune hyperthyroidism (SNAH). Up to date 17 constitutively activating TSHR mutations have been reported in 24 families with FNAH. The diagnosis of FNAH should be considered in cases with a positive family history, early onset of hyperthyroidism, goiter, absence of clinical stigmata of autoimmunity and recurrent hyperthyroidism. Moreover, 14 subjects with sporadic non-autoimmune hyperthyroidism and 10 different TSH receptor germline mutations have been reported. The main characteristic of SNAH is a negative family history. Additional consequences of prolonged neonatal hyperthyroidism (mental retardation, speech disturbances and craniosynostosis) have often been reported in SNAH. No genotype-phenotype relationship has been reported in patients with germline TSHR mutations. There is no association of in vitro activities determined by linear regression analysis (LRA) and several clinical indicators of hyperthyroidism activity for SNAH. However, the comparison of the LRA values of sporadic TSHR mutations with LRA values of familial TSHR mutations does show a significantly higher median LRA value for sporadic as compared to familial autosomal dominant hyperthyroidism. This finding is in line with the clinical impression of a more active clinical course in patients with SNAH. However, additional genetic, constitutional or environmental factors are most likely responsible for the phenotypic variations of the disease and the lack of correlation between in vitro activities of the TSHR mutations and the severity of hyperthyroidism. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

The role of allopurinol on oxidative stress in experimental hyperthyroidism.

PubMed

Makay, O; Yenisey, C; Icoz, G; Genc Simsek, N; Ozgen, G; Akyildiz, M; Yetkin, E

2009-09-01

During hyperthyroidism, production of free oxygen radicals derives, where xanthine oxidase may also play an important role. Allopurinol, a xanthine oxidase inhibitor, has a significant effect on thyrotoxicosis-related oxidative stress. However, the relationship between thyroid hormones, oxidative stress parameters and allopurinol remains to be explored. Forty-two Wistar albino rats were divided into three groups. Rats in group A served as negative controls, while group B had untreated thyrotoxicosis and group C received allopurinol. Hyperthyroidism was induced by daily 0.2 mg/kg L-thyroxine intraperitoneally in groups B and C; 40 mg/kg allopurinol were given daily intraperitoneally. Efficacy of the treatment was assessed after 72 h and 21 days, by measuring serum xanthine oxidase (XO), malondialdehyde (MDA), glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx) and nitric oxide derivates (NO*x). In both time periods, serum XO, MDA, GSH and NO*x levels were significantly increased after thyroid hormone induction (p<0.05). Levels of XO, MDA and NO*x decreased with allopurinol treatment (p<0.05). There was a remarkable decrease in triiodothyronine levels in group C after 72 h (p<0.05), and in both triiodothyronine and thyroxine levels in group C after 21 days (p<0.05). There was no difference between groups B and C in means of serum GSH, GR and GPx levels (p>0.05). This study suggests an association between allopurinol and the biosynthesis of thyroid hormones. Allopurinol prevents the hyperthyroid state, which is mediated predominantly by triiodothyronine and not by XO. This issue has to be questioned in further studies where allopurinol is administered in control subjects.

The role of the autonomic nervous system in the resting tachycardia of human hyperthyroidism.

PubMed

Maciel, B C; Gallo, L; Marin Neto, J A; Maciel, L M; Alves, M L; Paccola, G M; Iazigi, N

1987-02-01

The mechanisms that control resting heart rate in hyperthyroidism were evaluated in six patients before and after treatment with propylthiouracil. The patients were subjected to pharmacological blockade under resting conditions in two experimental sessions: first session, propranolol (0.2 mg/kg body weight); second session, atropine (0.04 mg/kg body weight) followed by propranolol (0.2 mg/kg body weight). All drugs were administered intravenously. Resting heart rate was significantly reduced from 100 +/- 6.5 beats/min to 72 +/- 2.5 beats/min (P less than 0.005) after clinical and laboratory control of the disease. After double blockade, intrinsic heart rate was reduced from 105 +/- 6.8 beats/min before treatment to 98 +/- 6.0 beats/min after treatment (P less than 0.025). The reduction in heart rate caused by propranolol was not significantly different before (-13 +/- 1.4 beats/min) and after (-9 +/- 1.0 beats/min) propylthiouracil. In contrast, atropine induced a higher elevation of heart rate after treatment (45 +/- 8.6 beats/min) than before treatment (26 +/- 4.0 beats/min). The present results suggest no appreciable participation of the sympathetic component of the autonomic nervous system in the tachycardia of hyperthyroidism, at least under the conditions of the present study. The small change observed in intrinsic heart rate, although significant, seems to indicate that this is not the most important mechanism involved in this tachycardia. Our results suggest that an important reduction in the efferent activity of the parasympathetic component participates in the mechanisms that modify resting heart rte in hyperthyroidism.

Sclerostin Blockade and Zoledronic Acid Improve Bone Mass and Strength in Male Mice With Exogenous Hyperthyroidism.

PubMed

Tsourdi, Elena; Lademann, Franziska; Ominsky, Michael S; Rijntjes, Eddy; Köhrle, Josef; Misof, Barbara M; Roschger, Paul; Klaushofer, Klaus; Hofbauer, Lorenz C; Rauner, Martina

2017-11-01

Hyperthyroidism in mice is associated with low bone mass, high bone turnover, and high concentrations of sclerostin, a potent Wnt inhibitor. Here, we explored the effects of either increasing bone formation with sclerostin antibodies (Scl-Ab) or reducing bone turnover with bisphosphonates on bone mass and strength in hyperthyroid mice. Twelve-week-old C57BL/6 male mice were rendered hyperthyroid using l-thyroxine (T4; 1.2 µg/mL added to the drinking water) and treated with 20 mg/kg Scl-Ab twice weekly or 100 µg/kg zoledronic acid (ZOL) once weekly or phosphate-buffered saline for 4 weeks. Hyperthyroid mice displayed a lower trabecular bone volume at the spine (-42%, P < 0.05) and the distal femur (-55%, P < 0.05) compared with euthyroid controls. Scl-Ab and ZOL treatment of hyperthyroid mice increased trabecular bone volume at the spine by threefold and twofold, respectively. Serum bone formation and resorption markers were increased in hyperthyroid mice and suppressed by treatment with ZOL but not Scl-Ab. Trabecular bone stiffness at the lumbar vertebra was 63% lower in hyperthyroid mice (P < 0.05) and was increased fourfold by Sci-Ab (P < 0.001) and threefold by ZOL treatment (P < 0.01). Bone strength based on ultimate load, which was 10% lower in hyperthyroidism, was increased by Scl-Ab by 71% and ZOL by 22% (both P < 0.001). Increased proportion of low mineralized bone seen in hyperthyroid mice was restored by treatment with Scl-Ab and ZOL. Thus, bone-forming and antiresorptive drugs prevent bone loss in hyperthyroid mice via different mechanisms. Copyright © 2017 Endocrine Society.

Hyperthyroidism is associated with work disability and loss of labour market income. A Danish register-based study in singletons and disease-discordant twin pairs.

PubMed

Brandt, Frans; Thvilum, Marianne; Hegedüs, Laszlo; Brix, Thomas Heiberg

2015-11-01

To examine the risk of disability pension and changes in labour market income in patients with hyperthyroidism. From a 5% random sample of the Danish population and twins from the Danish Twin Registry we identified 1942 hyperthyroid singletons and 7768 non-hyperthyroid (matched 1:4) controls as well as 584 same-sex twin pairs discordant for hyperthyroidism. Singletons and twins were followed for a mean of 9 years (range 1-20). Cox regression analysis was used to examine the risk of disability pension and a difference-in-differences model was used to evaluate changes in labour market income. Hyperthyroid individuals had an increased risk of receiving disability pension: hazard ratio (HR) was 1.88, (95% CI: 1.57-2.24). Subdividing as to the cause of hyperthyroidism did not change this finding: Graves' disease (GD) HR was 1.51 (95% CI: 0.87-2.63) and toxic nodular goitre (TNG) HR was 2.10 (95% CI: 1.02-4.36). With respect to labour market income, the income of hyperthyroid individuals increased on average 1189 € less than their controls (P<0.001). This difference in income was more pronounced in GD (2539 €) than in TNG (132 €). Essentially similar results, with respect to disability pension and labour market income, were seen within monozygotic twin pairs discordant for hyperthyroidism. Hyperthyroidism is associated with severe work disability as reflected by an 88% increased risk of receiving disability pension and a significant loss of labour market income. Similar results in monozygotic twins discordant for hyperthyroidism suggest that genetic confounding is unlikely. © 2015 European Society of Endocrinology.

Hyperthyroidism and psychiatric morbidity: evidence from a Danish nationwide register study.

PubMed

Brandt, Frans; Thvilum, Marianne; Almind, Dorthe; Christensen, Kaare; Green, Anders; Hegedüs, Laszlo; Brix, Thomas Heiberg

2014-02-01

Thyroid hormones are essential for the normal development of the fetal brain, while hyperthyroidism in adults is associated with mood symptoms and reduced quality of life. In this study, we aimed to investigate the association and temporal relationship between hyperthyroidism and psychiatric morbidity. Register-based nationwide cohort study. Data on hyperthyroidism and psychiatric morbidity were obtained by record linkage of the Danish National Patient Registry and the Danish National Prescription Registry. A total of 2631 hyperthyroid individuals were identified and matched 1:4 with non-hyperthyroid controls and followed for a mean duration of 6 years (range 0-13). Logistic and Cox regression models were used to assess the risk of psychiatric morbidity before and after the diagnosis of hyperthyroidism respectively. BEFORE THE DIAGNOSIS OF HYPERTHYROIDISM, SUCH INDIVIDUALS HAD AN INCREASED RISK OF BEING HOSPITALIZED WITH PSYCHIATRIC DIAGNOSES (ODDS RATIO (OR): 1.33; 95% CI: 0.98-1.80) and an increased risk of being treated with antipsychotics (OR: 1.17; 95% CI: 1.00-1.38), antidepressants (OR: 1.13; 95% CI: 1.01-1.27), or anxiolytics (OR: 1.28; 95% CI: 1.16-1.42). After the diagnosis of hyperthyroidism, there was a higher risk of being hospitalized with psychiatric diagnoses (hazard ratio (HR): 1.51; 95% CI: 1.11-2.05) and an increased risk of being treated with antipsychotics (HR: 1.46; 95% CI: 1.20-1.79), antidepressants (HR: 1.54; 95% CI: 1.36-1.74), or anxiolytics (HR: 1.47; 95% CI: 1.27-1.69). Hyperthyroid individuals have an increased risk of being hospitalized with psychiatric diagnoses and being treated with antipsychotics, antidepressants, and anxiolytics, both before and after the diagnosis of hyperthyroidism.

Adrenocortical reserves in hyperthyroidism.

PubMed

Agbaht, Kemal; Gullu, Sevim

2014-02-01

Explicit data regarding the changes in adrenocortical reserves during hyperthyroidism do not exist. We aimed to document the capability (response) of adrenal gland to secrete cortisol and DHEA-S during hyperthyroidism compared to euthyroidism, and to describe factors associated with these responses. A standard-dose (0.25 mg/i.v.) ACTH stimulation test was performed to the same patients before hyperthyroidism treatment, and after attainment of euthyroidism. Baseline cortisol (Cor(0)), DHEA-S (DHEA-S(0)), cortisol binding globulin (CBG), ACTH, calculated free cortisol (by Coolen's equation = CFC), free cortisol index (FCI), 60-min cortisol (Cor(60)), and DHEA-S (DHEA-S(60)), delta cortisol (ΔCor), delta DHEA-S (ΔDHEA-S) responses were evaluated. Forty-one patients [22 females, 49.5 ± 15.2 years old, 32 Graves disease, nine toxic nodular goiter] had similar Cor(0), DHEA-S(0), CFC, FCI, and DHEA-S(60) in hyperthyroid and euthyroid states. Cor(60), ΔCor, and ΔDHEA-S were lower in hyperthyroidism. In four (10 %) patients the peak ACTH-stimulated cortisol values were lower than 18 μg/dL. When the test repeated after attainment of euthyroidism, all of the patients had normal cortisol response. Regression analysis demonstrated an independent association of Cor(60) with free T3 in hyperthyroidism. However, the predictors of CFC, FCI, and DHEA-S levels were serum creatinine levels in hyperthyroidism, and both creatinine and transaminase levels in euthyroidism. ACTH-stimulated peak cortisol, delta cortisol, and delta DHEA-S levels are decreased during hyperthyroidism, probably due to increased turnover. Since about 10 % of the subjects with hyperthyroidism are at risk for adrenal insufficiency, clinicians dealing with Graves' disease should be alert to the possibility of adrenal insufficiency during hyperthyroid stage.

Circulating Levels of Orexin-A, Nesfatin-1, Agouti-Related Peptide, and Neuropeptide Y in Patients with Hyperthyroidism.

PubMed

Tohma, Yusuf; Akturk, Mujde; Altinova, Alev; Yassibas, Emine; Cerit, Ethem Turgay; Gulbahar, Ozlem; Arslan, Metin; Sanlier, Nevin; Toruner, Fusun

2015-07-01

There is insufficient information about the appetite-related hormones orexin-A, nesfatin-1, agouti-related peptide (AgRP), and neuropeptide Y (NPY) in hyperthyroidism. The aim of the present study was to investigate the effects of hyperthyroidism on the basal metabolic rate (BMR) and energy intake, orexin-A, nesfatin-1, AgRP, NPY, and leptin levels in the circulation, and their relationship with each other and on appetite. In this prospective study, patients were evaluated in hyperthyroid and euthyroid states in comparison with healthy subjects. Twenty-one patients with overt hyperthyroidism and 33 healthy controls were included in the study. Daily energy intake in the hyperthyroid state was found to be higher than that in the euthyroid state patient group (p=0.039). BMR was higher in hyperthyroid patients than the control group (p=0.018). Orexin-A was lower and nesfatin-1 was higher in hyperthyroid patients compared to the controls (p<0.001), whereas orexin-A increased and nesfatin-1 decreased after euthyroidism (p=0.003, p<0.001). No differences were found in the AgRP, NPY, and leptin levels between the hyperthyroid and euthyroid states and controls (p>0.05). Orexin-A correlated negatively with nesfatin-1 (p=0.042), BMR (p=0.013), free triiodothyronine (fT3; p<0.001), and free thyroxine (fT4; p<0.001) and positively with thyrotropin (TSH; p<0.001). Nesfatin-1 correlated negatively with orexin-A (p=0.042) and TSH (p<0.001) and positively with fT3 (p=0.005) and fT4 (p=0.001). In the regression analysis, "diagnosis of hyperthyroidism" was the main factor affecting orexin-A (p<0.001). Although it seems that no relationship exists among orexin-A, nesfatin-1, and increased appetite in hyperthyroidism, the orexin-A and nesfatin-1 levels are markedly affected by hyperthyroidism.

Serum Cystatin C Concentrations in Cats with Hyperthyroidism and Chronic Kidney Disease.

PubMed

Williams, T L; Dillon, H; Elliott, J; Syme, H M; Archer, J

2016-07-01

Currently, no test can accurately predict the development of azotemia after treatment of hyperthyroidism. Serum cystatin C concentrations (sCysC) might be less influenced by changes in body muscle mass and so better indicate the presence of concurrent chronic kidney disease (CKD) in hyperthyroidism. sCysC will be higher in hyperthyroid cats that develop azotemia compared with hyperthyroid cats that remain nonazotemic after treatment; sCysC will be higher in nonhyperthyroid cats with azotemic CKD than healthy older cats and, sCysC will decrease after treatment of hyperthyroidism. Ninety-one cats treated in first opinion practice. Case-control study. sCysC were compared between hyperthyroid cats which developed azotemia within 4 months of successful treatment of hyperthyroidism (pre-azotemic group) and hyperthyroid cats which remained nonazotemic after treatment (nonazotemic group), and between nonhyperthyroid cats with azotemic CKD and healthy older cats. sCysC were also compared between hyperthyroid cats before treatment and at time of establishment of euthyroidism. Data are presented as median [25th, 75th percentile]. Baseline sCysC were not different between the pre-azotemic and nonazotemic groups (1.9 [1.4, 2.3] mg/L versus 1.5 [1.1, 2.2] mg/L, respectively; P = .22). sCysC in nonhyperthyroid cats with azotemic CKD and healthy older cats were not significantly different (1.5 [1.0, 1.9] mg/L versus 1.2 [0.8, 1.4] mg/L, respectively; P = .16). sCysC did not change significantly after treatment of hyperthyroidism (pretreatment 1.8 [1.2, 2.3] mg/L, after treatment 1.6 [1.1, 2.4] mg/L; P = .82). sCysC do not appear to be a reliable marker of renal function in hyperthyroid cats. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Evaluation of Serum Thyroid-Stimulating Hormone Concentration as a Diagnostic Test for Hyperthyroidism in Cats.

PubMed

Peterson, M E; Guterl, J N; Nichols, R; Rishniw, M

2015-01-01

In humans, measurement of serum thyroid-stimulating hormone (TSH) concentration is commonly used as a first-line discriminatory test of thyroid function. Recent reports indicate that canine TSH (cTSH) assays can be used to measure feline TSH and results can help diagnose or exclude hyperthyroidism. To investigate the usefulness of cTSH measurements as a diagnostic test for cats with hyperthyroidism. Nine hundred and seventeen cats with untreated hyperthyroidism, 32 euthyroid cats suspected of having hyperthyroidism, and 131 clinically normal cats. Prospective study. Cats referred to the Animal Endocrine Clinic for suspected hyperthyroidism were evaluated with serum T4, T3, free T4 (fT4), and TSH concentrations. Thyroid scintigraphy was used as the gold standard to confirm or exclude hyperthyroidism. Median serum TSH concentration in the hyperthyroid cats (<0.03 ng/mL) was significantly (P < .001) lower than concentrations in clinically normal cats (0.05 ng/mL) or euthyroid cats with suspected thyroid disease (0.06 ng/mL). Only 18 (2.0%) hyperthyroid cats had measurable TSH concentrations (≥0.03 ng/mL), whereas 114 (69.9%) of the 163 euthyroid cats had detectable concentrations. Combining serum TSH with T4 or fT4 concentrations lowered the test sensitivity of TSH from 98.0 to 97.0%, but markedly increased overall test specificity (from 69.9 to 98.8%). Serum TSH concentrations are suppressed in 98% of hyperthyroid cats, but concentrations are measurable in a few cats with mild-to-moderate hyperthyroidism. Measurement of serum TSH represents a highly sensitive but poorly specific test for diagnosis of hyperthyroidism and is best measured in combination with T4 and fT4. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Dietary-induced hyperthyroidism marginally affects neonatal testicular development.

PubMed

Rijntjes, Eddy; Wientjes, Anna T; Swarts, Hans J M; de Rooij, Dirk G; Teerds, Katja J

2008-01-01

The objective of this study was to determine whether dietary-induced mild fetal/neonatal hyperthyroidism influenced the initiation of spermatogenesis and the development of the adult-type Leydig cell population. Previously, the effects of neonatally induced hyperthyroidism have been investigated in rats using rather high doses (5 to 10 microg/100 g body weight) of tri-iodothyronine, which not only influenced testicular development, but also negatively affected the general body condition of the animals. To induce hyperthyroidism the diet of the dams was supplemented with 15 mug thyroxine (T(4))/100 g body weight 2 weeks prior to mating and the dams and their offspring were kept on this diet until sacrifice. Pups were killed between days 7 and 64 after birth. At the age of 12 days plasma thyroid-stimulating hormone (TSH) levels tended to be lower in hyperthyroid pups, and from the age of 15 days onwards plasma TSH levels were significantly lower in hyperthyroid animals. Concomitantly, plasma T(4) levels were significantly elevated. From the age of 12 days onwards, plasma follicle-stimulating hormone levels were lower in hyperthyroid animals compared with age-matched control groups. Sertoli cell differentiation did not seem to be influenced by the mild hyperthyroid condition, as no difference in tubule lumen formation was observed between euthyroid and hyperthyroid animals. Nevertheless, a small effect on the progression of spermatogenesis was observed 15 days after birth, as the most advanced type of germ cells in the control testis were pachytene spermatocytes, whereas in the hyperthyroid testis these were leptotene and zygotene spermatocytes. Leydig cell proliferation was decreased in the hyperthyroid pups at the age of 15 days and slightly elevated at later ages, suggesting a possible slower onset of the proliferative activity of these cells than in the euthyroid control animals. Taken together, the present results suggest that even mild dietary-induced hyperthyroidism transiently affects the development of the adult-type Leydig cell population as well as the initial progression of spermatogenesis.

Effect of hyperthyroidism on clearance and secretion of glucagon in man.

PubMed

Dimitriadis, G; Hatziagelaki, E; Mitrou, P; Lambadiari, V; Maratou, E; Raptis, A E; Gerich, J E; Raptis, S A

2011-04-01

Glucagon has been proposed to contribute to the increased glucose production found in hyperthyroidism. However, fasting plasma glucagon levels are not increased in hyperthyroidism suggesting that the activity of the α-cell is normal. Nevertheless, an increase in the clearance rate of glucagon may mask increased glucagon secretion. This study was designed to examine the effects of hyperthyroidism on the kinetics of glucagon. A primed-continuous infusion of glucagon was administered to 9 euthyroid and 9 hyperthyroid subjects at 3 sequential rates (1,200, 3,000 and 6,000 pg/kg/min, each given for 2 h). Arterialized blood was drawn at 15-30 min intervals for determination of glucagon. Fasting plasma glucagon levels were comparable in euthyroids (195±8 pg/ml) and hyperthyroids (231±16 pg/ml). During infusions (1,200, 3,000 and 6,000 pg/kg/min), plasma glucagon increased to 387±19, 624±44 and 977±51 pg/ml in euthyroids and to 348±23, 597±42 and 938±56 pg/ml in hyperthyroids respectively. At these infusion rates, metabolic clearance of glucagon (ml/kg/min) was 6.6±0.5, 7.4±0.6 and 7.9±0.5 in euthyroids and 12.6±2, 8.9±1 and 8.8±0.6 in hyperthyroids, respectively. Metabolic clearance of glucagon differed between hyperthyroids and euthyroids at 1 200 pg/kg/min infusion rate (p=0.001). The basal delivery rate of glucagon (ng/kg/min) was 1.3±0.1 in euthyroids and 2.9±0.6 in hyperthyroids (p=0.0005). In hyperthyroidism, the secretion and metabolic clearance rates of glucagon are increased. These effects may explain the changes in plasma glucagon levels observed in hyperthyroidism and support the important role of glucagon in increasing endogenous glucose production in this condition. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

Lower urinary tract symptoms and urinary flow rates in female patients with hyperthyroidism.

PubMed

Ho, Chen-Hsun; Chang, Tien-Chun; Guo, Ya-Jun; Chen, Shyh-Chyan; Yu, Hong-Jeng; Huang, Kuo-How

2011-01-01

To investigate lower urinary tract symptoms (LUTS) and voiding function in a cohort of hyperthyroid women. The autonomic nervous system (ANS) imbalance has been thought to cause LUTS in hyperthyroidism. Between January 2008 and December 2008, 65 newly diagnosed, untreated female hyperthyroid patients were enrolled in this study. Another 62 age-matched healthy women were enrolled as a control group. Demographics, LUTS, urinary flow rates, hyperthyroid symptoms, and serum levels of thyroid hormones were recorded before and after the medical treatment for hyperthyroidism. Compared with the control group, the hyperthyroid patients had a higher mean symptom score of frequency (1.15 ± 1.75 vs 0.31 ± 1.05, P = .01), incomplete emptying (0.91 ± 1.47 vs 0.29 ± 1.12, P = .02), straining (1.05 ± 0.85 vs 0.27 ± 0.51, P <.01), voiding symptoms (3.05 ± 3.28 vs 1.06 ± 2.63, P <.01), and total symptoms (5.88 ± 6.17 vs 2.76 ± 4.65, P <.01). Fifty-three (81.5%) of them had an IPSS of <8, while only 12 (18.5%) had an International Prostate Symptom Score (IPSS) of ≥8. Hyperthyroid women demonstrated a lower mean peak flow rate (25.0 ± 5.3 vs 28.6 ± 6.1 mL/s, P = .02). After treatment, both LUTS and flow rates improved significantly. The severity of LUTS was associated with neither serum levels of thyroid hormone nor other hyperthyroid symptoms. Hyperthyroid women have worse LUTS and lower peak flow rates than healthy controls. However, the severity of LUTS is only mild (IPSS <8) in the majority, and only 18.5% have moderate-to-severe LUTS. Both LUTS and flow rates improve after the treatment for hyperthyroidism. The exact mechanisms of LUTS and/or lower urinary tract dysfunction in hyperthyroidism require further investigation. Copyright © 2011 Elsevier Inc. All rights reserved.

Morbidity before and after the diagnosis of hyperthyroidism: a nationwide register-based study.

PubMed

Brandt, Frans; Thvilum, Marianne; Almind, Dorthe; Christensen, Kaare; Green, Anders; Hegedüs, Laszlo; Brix, Thomas Heiberg

2013-01-01

Hyperthyroidism has been linked with different morbidities, like atrial fibrillation, stroke and diabetes mellitus. However, our knowledge regarding the extent and temporal relation between hyperthyroidism and other diseases is fragmented. Here, we aimed at evaluating various morbidities before and after the diagnosis of hyperthyroidism. Observational cohort study. From nationwide Danish health registers 2631 hyperthyroid singletons and 375 twin pairs discordant for hyperthyroidism were identified and followed for an average of 6 years (range 0-13). Data on the occurrence of cardiovascular diseases, lung diseases, diabetes mellitus, rheumatic diseases and malignant diseases was obtained by person-to-person record linkage with the National Danish Patient Register and/or the Danish National Prescription Registry (lung diseases and diabetes mellitus). Logistic and Cox regression models were used to assess the risk of morbidity before and after the diagnosis of hyperthyroidism, respectively. All Cox regression analyses were adjusted for the degree of co-morbidity preceding the diagnosis of hyperthyroidism, using the Charlson score. Hyperthyroid individuals had a significantly higher risk of being diagnosed with cardiovascular diseases (odds ratio (OR) 1.65; 95% confidence interval (CI): 1.45-1.87), lung diseases (OR 1.53; 95% CI: 1.29-1.60), and diabetes mellitus (OR 1.43, 95% CI: 1.20-1.72), but not with malignant diseases (OR 1.16, 95% CI: 0.99-1.36) prior to the diagnosis of hyperthyroidism. After the diagnosis of hyperthyroidism, subjects had a significantly higher risk of being diagnosed with cardiovascular diseases (hazard ratio (HR) 1.34; 95% CI: 1.15-1.56), lung diseases (HR 1.28; 95% CI: 1.10-1.49), and diabetes mellitus (HR 1.46; 95% CI: 1.16-1.84), but not with rheumatic diseases (HR 1.39, 95% CI: 0.92-2.09) or malignant diseases (HR 1.18, 95% CI 0.97-1.42). We demonstrate a significantly increased burden of morbidity, both before and after the diagnosis of hyperthyroidism.

Prediction of Neonatal Hyperthyroidism.

PubMed

Banigé, Maïa; Polak, Michel; Luton, Dominique

2018-06-01

To assess whether it is possible to identify the neonatal predictors of neonatal hyperthyroidism at the presymptomatic stage of the disease. This retrospective multicenter study in 10 maternity units was based on the medical records of all patients monitored for a pregnancy between January 1, 2007, and January 1, 2014. Among 280 000 births, 2288 medical records of women with thyroid dysfunction were selected and screened. Of these, 415 women had Graves disease and were positive for thyrotropin receptor antibody during pregnancy, and were included. A thyroid-stimulating hormone (TSH) level of less than 0.90 mIU/L between days 3 and 7 of life predicted neonatal hyperthyroidism with a sensitivity 78% (95% CI, 74%-82%) and a and specificity of 99% (95% CI, 98%-100%), a positive predictive value of 90% (95% CI, 87%-93%), a negative predictive value of 98% (95% CI, 97%-99%), and an area under the receiver operating characteristic curve of 0.99 (95% CI, 0.97-1.0). A thyrotropin receptor antibody (TRAb) elimination time was calculated using the equation: 7.28 + 2.88 × log() + 11.62 log(TRAb 2 ). All newborns with a TSH level of less than 0.90 mIU/L should be examined by a pediatrician. Using TSH, it is possible to screen for neonatal hypothyroidism and for neonatal hyperthyroidism with a TSH cutoff of 0.90 mIU/L, and this shows the relevance of our study in terms of public health. Copyright © 2018 Elsevier Inc. All rights reserved.

Influence of hyperthyroidism on growth hormone secretion.

PubMed

Valcavi, R; Dieguez, C; Zini, M; Muruais, C; Casanueva, F; Portioli, I

1993-05-01

Hyperthyroidism is associated with altered GH secretion. Whether this is due to changes of somatotroph responsiveness or reflects an alteration in negative feedback signals at the hypothalamic level is unknown. We therefore performed a series of studies to shed some light onto this issue. Study 1: GHRH (1 microgram/kg b.w.) was injected i.v. in 38 hyperthyroid patients and in 30 normal subjects; in 11 of the patients the GHRH test was repeated following methimazole-induced remission of hyperthyroidism. Study 2: hGH (2 U i.v.) or saline were administered 3 hours prior to GHRH; six hyperthyroid patients and six normal subjects were studied. Study 3: ten normal subjects and ten hyperthyroid patients were given 75 g oral glucose or water 30 minutes before GHRH. Study 4: 11 normal subjects and eight hyperthyroid patients were studied. TRH or vehicle were dissolved in 250 ml of saline solution and infused at a rate of 400 micrograms/h for 150 minutes. Thirty minutes after the beginning of the infusions, L-arginine (30 g infused over 45 min i.v.) was administered. Hyperthyroid patients were compared to normal subjects. Growth hormone was measured by RIA at 15-minute intervals. GH responses to GHRH were subnormal in hyperthyroid patients. Following antithyroid drug treatment with methimazole, GH responses to GHRH increased in these patients in comparison to pretreatment values. Serum IGF-I levels, which were elevated before treatment, decreased after methimazole administration. Exogenous GH administration induced a clear decrease of GH responses to GHRH in both control and hyperthyroid subjects. On the other hand, oral glucose load decreased the GH responses to GHRH in normal but not in hyperthyroid subjects. TRH administration did not modify the GH responses to arginine in either normal subjects or hyperthyroid patients. Hyperthyroidism is associated with increased serum IGF-I levels and marked alterations in the neuroregulation of GH secretion. These changes involve decreased GH responsiveness to GHRH at the pituitary level and, at the hypothalamic level, a lack of suppressive effect of an oral glucose load. The normal inhibitory effect of exogenous GH administration but not of an oral glucose load in hyperthyroid patients suggests that these two feedback signals act through different mechanisms. The lack of effect of a TRH infusion on GH responses to L-arginine in normal and hyperthyroid patients makes an inhibitory role for TRH in GH secretion unlikely, at least in Caucasian subjects.

[Isolated thyroid gland sarcoidosis and hyperthyroidism].

PubMed

Langsteger, W; Lind, P; Beham, A; Költringer, P; Eber, O

1989-04-29

A case of isolated sarcoidosis of the thyroid gland, associated with hyperthyroidism, is reported in a 28-year-old male patient whose thyroid was removed for hyperthyroid multinodular goitre. Histology revealed a regressive adenoma and sarcoidosis in non-adenomatous thyroid residue. Further diagnosis, therapeutic management and a 3-year follow-up did not disclose any specific changes or involvement of other tissues. Isolated thyroidal sarcoidosis with hyperthyroid alterations are extremely rare and mostly chance findings; simultaneous occurrence of thyroid sarcoidosis and hyperthyroidism may be a symptom of gland infiltration for which an adequate explanation is still lacking.

Maternal hyperthyroidism after intrauterine insemination due to hypertrophic action of human chorionic gonadotropin: a case report.

PubMed

Bakas, P; Tzouma, C; Creatsa, M; Boutas, I; Hassiakos, D

2016-01-01

To report a rare case of maternal hyperthyroidism after intrauterine insemination due to hypertrophic action of hCG. A 36-year-old woman after successful intrauterine insemination and triplet pregnancy, developed hyperthyroidism with resistance to medical treatment. All signs of hyperthyroidism resolved and the results of thyroid function tests returned to normal without any medication after embryo meiosis. De novo maternal hyperthyroidism may develop during pregnancy as a result of pathological stimulation of the thyroid gland from the high levels of hCG hormone that can be seen in multiple pregnancies. The risk of hyperthyroidism is related to the number of fetuses. Reversibility of symptomatology can be seen after fetal reduction of multiple pregnancies.

Speech and language delay in two children: an unusual presentation of hyperthyroidism.

PubMed

Sohal, Aman P S; Dasarathi, Madhuri; Lodh, Rajib; Cheetham, Tim; Devlin, Anita M

2013-01-01

Hyperthyroidism is rare in pre-school children. Untreated, it can have a profound effect on normal growth and development, particularly in the first 2 years of life. Although neurological manifestations of dysthyroid states are well known, specific expressive speech and language disorder as a presentation of hyperthyroidism is rarely documented. Case reports of two children with hyperthyroidism presenting with speech and language delay. We report two pre-school children with hyperthyroidism, who presented with expressive speech and language delay, and demonstrated a significant improvement in their language skills following treatment with anti-thyroid medication. Hyperthyroidism must be considered in all children presenting with speech and language difficulties, particularly expressive speech delay. Prompt recognition and early treatment are likely to improve outcome.

Effects of a short-term coordination exercise program during school recess: agility of seven- to eight-year-old elementary school children.

PubMed

Yasumitsu, Tatsuo; Nogawa, Haruo

2013-04-01

This study tested the effect of a short-term coordination program focused on improving the agility of school children ages 7 to 8 years. Healthy Japanese children were placed in an experimental group of 26 children (10 girls, 16 boys) and a control group of 20 children (9 girls, 11 boys). The experimental group participated in 10 coordination program sessions during recesses; each session was performed 1 to 3 times per week, for 26 days. No differences were observed between the groups in repeated side-step scores prior to the program, although an interaction was observed after the completion of the treatment. The short-term coordination program was effective in increasing the agility of elementary school children aged 7 to 8 years.

Slave to the Rhythm: Experimental Tests of a Model for Verbal Short-Term Memory and Long-Term Sequence Learning

ERIC Educational Resources Information Center

Hitch, Graham J.; Flude, Brenda; Burgess, Neil

2009-01-01

Three experiments tested predictions of a neural network model of phonological short-term memory that assumes separate representations for order and item information, order being coded via a context-timing signal [Burgess, N., & Hitch, G. J. (1999). Memory for serial order: A network model of the phonological loop and its timing. "Psychological…

Hyperthyroid and Hypothyroid Status Was Strongly Associated with Gout and Weakly Associated with Hyperuricaemia

PubMed Central

See, Lai-Chu; Kuo, Chang-Fu; Yu, Kuang-Hui; Luo, Shue-Fen; Chou, I-Jun; Ko, Yu-Shien; Chiou, Meng-Jiun; Liu, Jia-Rou

2014-01-01

Objectives The aim of this study was to estimate the risk of hyperuricaemia and gout in people with hypothyroid or hyperthyroid status. Methods This study analyzed data from individuals who participated in health screening programs at Chang Gung Memorial Hospital in northern Taiwan (2000–2010). Participants were categorized as having euthyroid, hypothyroid, or hyperthyroid status according to their thyroid-stimulating hormone (TSH) levels. Multinomial logistic regression models were used to calculate the odds ratios (95% CI) for hyperuricaemia and gout in participants with thyroid dysfunction compared to euthyroid participants. Results A total of 87,813 (euthyroid, 83,502; hypothyroid, 1,460; hyperthyroid, 2,851) participants were included. The prevalence of hyperuricaemia was higher in hyperthyroid subjects (19.4%) than in euthyroid subjects (17.8%) but not in hypothyroid subjects (19.3%). The prevalence of gout was significantly higher in both hypothyroid (6.0%) and hyperthyroid (5.3%) subjects than in euthyroid subjects (4.3%). In men, hypothyroid or hyperthyroid status was not associated with hyperuricaemia. However, hypothyroid or hyperthyroid status was associated with ORs (95% CI) of 1.47 (1.10–1.97) and 1.37 (1.10–1.69), respectively, for gout. In women, hypothyroid status was not associated with hyperuricaemia or gout. However, hyperthyroid status was associated with ORs (95% CI) of 1.42 (1.24–1.62) for hyperuricaemia and 2.13 (1.58–2.87) for gout. Conclusions Both hyperthyroid and hypothyroid status were significantly associated with gout and weakly associated with hyperuricaemia. A thyroid function test for gout patients may by warranted. PMID:25486420

GLP-1 and GIP Levels in Patients With Hyperthyroidism: The Effect of Antithyroid Treatment.

PubMed

Cira, Duygu Kalkan; Sari, Ramazan; Ozdem, Sebahat; Yilmaz, Nusret; Bozkurt, Selen

2017-08-01

Incretin hormones (glucagon-like peptide-1 [GLP-1] and gastric inhibitory polypeptide [GIP]) may play a role in the development of glucose intolerance and hyperglycemia in patients with hyperthyroidism. We aimed to assess both incretin levels and treatment-induced changes in incretin levels in those with hyperthyroidism. A total of 24 subjects (12 with hyperthyroidism and 12 healthy) were enrolled in the study. Oral glucose tolerance test was performed and serum glucose, insulin GLP1, and GIP levels were evaluated at 0 (baseline), 30, 60, 90, and 120 minutes using ELISA. Measurements were repeated after euthyroidism was reached in subjects with hyperthyroidism. The baseline glucose level was higher in those with hyperthyroidism compared with controls ( P = 0.03). GLP-1 and GIP responses to oral glucose load did not differ significantly between those with hyperthyroidism and controls. Peak GLP-1 and GIP levels were reached in both groups at 60 and 90 minutes, respectively. Areas under the curve (AUCs) for GLP1 and GIP were similar in those with hyperthyroidism and controls. Although GLP-1 and GIP levels did not change before and after antithyroid treatment in subjects with hyperthyroidism, time to peak GLP-1 and GIP levels were reached at 30 minutes after euthyroid state was achieved. Reversal of hyperthyroid to euthyroid status did not induce significant changes in AUCs for incretins. The findings of the present study suggest that the total incretin response to oral glucose load is preserved in patients with hypertyhroidism, but peak incretin responses may change after achieving euthyroid state.

Hemodynamic and tissue oxygenation responses to exercise and beta-adrenergic blockade in patients with hyperthyroidism.

PubMed

Monachini, Maristela C; Lage, Silvia G; Ran, Miguel A N; Cardoso, Rita H A; Medeiros, Caio; Caramelli, Bruno; Sposito, Andrei C; Ramires, José A F

2004-07-01

Exercise-induced dyspnea is a frequent feature in patients with hyperthyroidism. Data from clinical studies to elucidate the origin of this symptom are lacking. In the current study, we examined the hemodynamic and oxygenation responses to exercise and beta-adrenergic blockade in patients with hyperthyroidism and their relationship with dyspnea. Hemodynamic studies were performed under resting conditions and after isotonic exercise in 15 patients with hyperthyroidism and 11 control subjects. Exercise was applied using a bicycle ergometer, with progressive loads. In the hyperthyroid group, measurements were repeated at rest and during supine exercise after administering 15 mg of intravenous metoprolol. End-diastolic pulmonary artery pressure and cardiac index were higher in the hyperthyroid group than in controls (18.6 +/- 5.3 vs. 11.2 +/- 4.9 mmHg; p = 0.02, and 6.0 +/- 1.7 vs. 2.8 +/- 0.5 l/min/m2; p = 0.0001, respectively). After exercise, there was an increase in end-diastolic pulmonary artery pressure in the hyperthyroid group (18.6 +/- 5.3 to 25.5 +/- 9.9 mmHg; p = 0.02), revealing impaired cardiocirculatory reserve. Pulmonary arteriolar resistance increased significantly in parallel with end-diastolic pulmonary artery pressure after drug administration, suggesting an inadequate cardiovascular response after beta blockade in patients with hyperthyroidism. We observed that functional left ventricular reserve is impaired in patients with hyperthyroidism, suggesting an explanation for the frequent symptom of dyspnea and impaired exercise tolerance. Moreover, we also suggest that beta-adrenergic blockade may adversely affect cardiovascular function in patients with hyperthyroidism.

Association of transient hyperthyroidism and severity of hyperemesis gravidarum.

PubMed

Malek, Nor Zila Hassan; Kalok, Aida; Hanafiah, Zainal Abidin; Shah, Shamsul Azhar; Ismail, Nor Azlin Mohamed

2017-03-23

Background Transient non-immune hyperthyroidism in early pregnancy is hyperthyroidism diagnosed for the first time in early pregnancy, without evidence of thyroid autoimmunity or clinical findings of Grave's disease and resolved spontaneously as the pregnancy progressed. Hyperemesis gravidarum (HG) is the commonest cause with 66%-73% of women with severe HG were found to have elevated thyroid function. Materials and methods We conducted a cross sectional study to determine the prevalence of transient hyperthyroidism in patients with hyperemesis gravidarum and its relation to the severity of nausea and vomiting. Severity of nausea and vomiting in pregnancy was assessed using the modified pregnancy-unique quantification of emesis (PUQE) scoring system. Each patient had urine and blood investigations which also included a full blood count and thyroid and renal function tests. Patients with abnormal thyroid function were retested at 20 weeks of gestation. The patients' demographic data, electrolyte levels, thyroid function and their respective PUQE score were analyzed. Results The prevalence of transient hyperthyroidism in women with hyperemesis gravidarum was 4.8%. Although there was a significant association between the severity of the PUQE score and hypokalemia (p = 0.001), there was no significant association with transient hyperthyroidism in early pregnancy (p = 0.072). Free T4 and TSH values of all women with transient hyperthyroidism were normalized by 20 weeks of gestation. Conclusion Transient hyperthyroidism in pregnancy is not significantly associated with the severity of the PUQE score. Women with transient hyperthyroidism in pregnancy are normally clinically euthyroid, hence a routine thyroid function test is unnecessary unless they exhibit clinical signs or symptoms of hyperthyroidism.

Hyperthyroidism increases brown fat metabolism in humans.

PubMed

Lahesmaa, Minna; Orava, Janne; Schalin-Jäntti, Camilla; Soinio, Minna; Hannukainen, Jarna C; Noponen, Tommi; Kirjavainen, Anna; Iida, Hidehiro; Kudomi, Nobuyuki; Enerbäck, Sven; Virtanen, Kirsi A; Nuutila, Pirjo

2014-01-01

Thyroid hormones are important regulators of brown adipose tissue (BAT) development and function. In rodents, BAT metabolism is up-regulated by thyroid hormones. The purpose of this article was to investigate the impact of hyperthyroidism on BAT metabolism in humans. This was a follow-up study using positron emission tomography imaging. Glucose uptake (GU) and perfusion of BAT, white adipose tissue, skeletal muscle, and thyroid gland were measured using [18F]2-fluoro-2-deoxy-D-glucose and [15O]H2O and positron emission tomography in 10 patients with overt hyperthyroidism and in 8 healthy participants. Five of the hyperthyroid patients were restudied after restoration of euthyroidism. Supraclavicular BAT was quantified with magnetic resonance imaging or computed tomography and energy expenditure (EE) with indirect calorimetry. Compared with healthy participants, hyperthyroid participants had 3-fold higher BAT GU (2.7±2.3 vs 0.9±0.1 μmol/100 g/min, P=.0013), 90% higher skeletal muscle GU (P<.005), 45% higher EE (P<.005), and a 70% higher lipid oxidation rate (P=.001). These changes were reversible after restoration of euthyroidism. During hyperthyroidism, serum free T4 and free T3 were strongly associated with EE and lipid oxidation rates (P<.001). TSH correlated inversely with BAT and skeletal muscle glucose metabolism (P<.001). Hyperthyroidism had no effect on BAT perfusion, whereas it stimulated skeletal muscle perfusion (P=.04). Thyroid gland GU did not differ between hyperthyroid and euthyroid study subjects. Hyperthyroidism increases GU in BAT independently of BAT perfusion. Hyperthyroid patients are characterized by increased skeletal muscle metabolism and lipid oxidation rates.

Activation of adenosine A(1) receptors alters behavioral and biochemical parameters in hyperthyroid rats.

PubMed

Bruno, Alessandra Nejar; Fontella, Fernanda Urruth; Bonan, Carla Denise; Barreto-Chaves, Maria Luiza M; Dalmaz, Carla; Sarkis, João José Freitas

2006-02-28

Adenosine acting on A(1) receptors has been related with neuroprotective and neuromodulatory actions, protection against oxidative stress and decrease of anxiety and nociceptive signaling. Previous studies demonstrated an inhibition of the enzymes that hydrolyze ATP to adenosine in the rat central nervous system after hyperthyroidism induction. Manifestations of hyperthyroidism include increased anxiety, nervousness, high O(2) consumption and physical hyperactivity. Here, we investigated the effects of administration of a specific agonist of adenosine A(1) receptor (N(6)-cyclopentyladenosine; CPA) on nociception, anxiety, exploratory response, locomotion and brain oxidative stress of hyperthyroid rats. Hyperthyroidism was induced by daily intraperitoneal injections of l-thyroxine (T4) for 14 days. Nociception was assessed with a tail-flick apparatus and exploratory behavior, locomotion and anxiety were analyzed by open-field and plus-maze tests. We verified the total antioxidant reactivity (TAR), lipid peroxide levels by the thiobarbituric acid reactive species (TBARS) reaction and the free radicals content by the DCF test. Our results demonstrated that CPA reverted the hyperalgesia induced by hyperthyroidism and decreased the exploratory behavior, locomotion and anxiety in hyperthyroid rats. Furthermore, CPA decreased lipid peroxidation in hippocampus and cerebral cortex of control rats and in cerebral cortex of hyperthyroid rats. CPA also increased the total antioxidant reactivity in hippocampus and cerebral cortex of control and hyperthyroid rats, but the production of free radicals verified by the DCF test was changed only in cerebral cortex. These results suggest that some of the hyperthyroidism effects are subjected to regulation by adenosine A(1) receptor, demonstrating the involvement of the adenosinergic system in this pathology.

Cardiovascular haemodynamics and cardiac autonomic control in patients with subclinical and overt hyperthyroidism.

PubMed

Petretta, M; Bonaduce, D; Spinelli, L; Vicario, M L; Nuzzo, V; Marciano, F; Camuso, P; De Sanctis, V; Lupoli, G

2001-12-01

To characterize cardiac structure and function and cardiac autonomic control in patients with subclinical and overt hyperthyroidism. Thirty patients with subclinical hyperthyroidism and 30 with overt disease were selected from patients never previously treated for endocrinological disease in the outpatient clinic of our institution. Twenty normal individuals were studied as control group. Left ventricular structure and function and cardiac autonomic control were evaluated, respectively, by two-dimensional Doppler echocardiography and by 24-h Holter recording with heart rate variability analysis. Patients with overt hyperthyroidism showed greater values of left ventricular end-diastolic volume (P<0.05) and left ventricular mass (P<0.05) than patients with subclinical disease. In addition, the mean velocity of left ventricular fibre shortening (P<0.05) and left ventricular ejection fraction (P<0.05) were greater in patients with overt hyperthyroidism than in patients with subclinical disease. No difference in any of these parameters was detectable between normal subjects and patients with subclinical disease. The isovolumic relaxation period was shorter in patients with subclinical hyperthyroidism than in control individuals (P<0.05) and in patients with overt hyperthyroidism (P<0.05). As regards cardiac autonomic control, all time and frequency domain measures decreased progressively from control individuals to patients with subclinical hyperthyroidism and those with overt disease (P<0.001). Thyrotoxic patients show changes in left ventricular structure and increased echocardiographic indexes of myocardial contractility, whereas the only echocardiographic feature detectable in patients with subclinical hyperthyroidism is an increased velocity of left ventricular relaxation. Cardiac parasympathetic withdrawal is evident in patients with overt hyperthyroidism and in patients with subclinical disease.

Hyperthyroidism caused by acquired immune deficiency syndrome.

PubMed

Wang, J-J; Zhou, J-J; Yuan, X-L; Li, C-Y; Sheng, H; Su, B; Sheng, C-J; Qu, S; Li, H

2014-01-01

Acquired immune deficiency syndrome (AIDS) is an immune deficiency disease. The etiology of hyperthyroidism, which can also be immune-related, is usually divided into six classical categories, including hypophyseal, hypothalamic, thyroid, neoplastic, autoimmune and inflammatory hyperthyroidism. Hyperthyroidism is a rare complication of highly active antimicrobial therapy (HAART) for human immunodeficiency virus (HIV). Hyperthyroidism caused directly by AIDS has not been previously reported. A 29-year-old man who complained of dyspnea and asthenia for 1 month, recurrent fever for more than 20 days, and breathlessness for 1 week was admitted to our hospital. The thyroid function test showed that the level of free thyroxine (FT4) was higher than normal and that the level of thyroid-stimulating hormone (TSH) was below normal. He was diagnosed with hyperthyroidism. Additional investigations revealed a low serum albumin level and chest infection, along with diffuse lung fibrosis. Within 1 month, he experienced significant weight loss, no hand tremors, intolerance of heat, and perspiration proneness. We recommended an HIV examination; subsequently, AIDS was diagnosed based on the laboratory parameters. This is the first reported case of hyperthyroidism caused by AIDS. AIDS may cause hyperthyroidism by immunization regulation with complex, atypical, and easily ignored symptoms. Although hyperthyroidism is rare in patients with AIDS, clinicians should be aware of this potential interaction and should carefully monitor thyroid function in HIV-positive patients.

Pharmacokinetics and dromotropic activity of ajmaline in rats with hyperthyroidism.

PubMed Central

Hashimoto, Y.; Yasuhara, M.; Kamiya, A.; Okumura, K.; Hori, R.

1989-01-01

1. The pharmacokinetics and the dromotropic action (increased PQ interval) of intravenously administered ajmaline (2 mg kg-1) were studied in hyperthyroid rats with sinus tachycardia. The hyperthyroidism was induced by intraperitoneal injection of 3,5,3'-triiodo-L-thyronine (0.5 mg kg-1) for 4 days. 2. The change in the ajmaline concentration in whole blood could be described by a biexponential equation. The steady state distribution volume of ajmaline decreased from 4.81 l kg-1 in control rats to 3.80 l kg-1 in hyperthyroid rats and the total body blood clearance was slightly higher in hyperthyroid rats than in control rats. 3. Ajmaline exhibited a saturable binding to rat plasma proteins, and one kind of binding site was found in the observed range of concentrations. The binding capacity was 2 fold higher in hyperthyroid rats than in control rats. 4. On the basis of the plasma unbound concentration, ajmaline exhibited an increased negative dromotropic activity in hyperthyroid rats compared with control rats. 5. A positive correlation was found between the pacing rate and the dromotropic action of ajmaline on atrioventricular conduction in isolated perfused hearts. There was no significant difference in the rate-dependence of the effect of ajmaline on the heart between control and hyperthyroid rats. 6. Our findings suggest that the increased dromotropic activity of ajmaline is mainly due to the increased heart rate in hyperthyroid rats. PMID:2924068

Conversion of autoimmune hypothyroidism to hyperthyroidism.

PubMed

Furqan, Saira; Haque, Naeem-ul; Islam, Najmul

2014-08-03

Graves' disease and Hashimoto's thyroiditis are the two autoimmune spectrum of thyroid disease. Cases of conversion from hyperthyroidism to hypothyroidism have been reported but conversion from hypothyroidism to hyperthyroidism is very rare. Although such cases have been reported rarely in the past we are now seeing such conversions from hypothyroidism to hyperthyroidism more frequently in clinical practice. We are reporting three cases of middle aged Asian females who presented with classical symptoms of hypothyroidism and the investigations showed elevated thyroid stimulating hormone with positive thyroid antibodies. Diagnosis of autoimmune hypothyroidism was made and thyroxine replacement therapy was initiated. Patients became asymptomatic with normalization of thyroid stimulating hormone level. After few years they developed symptoms of hyperthyroidism with suppressed thyroid stimulating hormone level. Over replacement of thyroxine was considered and the dose of thyroxine was decreased, but they remain symptomatic. After gradual decrease in the dose of thyroxine it was stopped finally. Even after few months of stopping thyroxine, the symptoms of hyperthyroidism did not improve and the biochemical and imaging modalities confirmed that the patients have developed hyperthyroidism. Anti-thyroid treatment was then started and the patients became symptom free. High index of suspicion should be there for possible conversion of hypothyroidism to hyperthyroidism if a patient with primary hypothyroidism develops persistent symptoms of hyperthyroidism. Otherwise it can be missed easily considering it as an over replacement with thyroid hormone.

Decreased activity and expression of intestinal oligopeptide transporter PEPT1 in rats with hyperthyroidism in vivo.

PubMed

Ashida, Kayoko; Katsura, Toshiya; Saito, Hideyuki; Inui, Ken-ichi

2004-06-01

To examine the effect of thyroid hormone status on PEPT1 in vivo, the activity and expression of PEPT1 in the small intestine were examined in euthyroid and hyperthyroid rats. Hyperthyroidism was induced by treating rats with L-thyroxine (12 mg/L) in the drinking water for 21 days. Transport activity was measured by everted small intestinal preparations and in situ intestinal loop technique. Expressions of PEPT1 mRNA and protein were evaluated by competitive polymerase chain reaction and Western blotting, respectively. The uptake of [14C]glycylsarcosine by everted small intestinal preparations was significantly decreased in hyperthyroid rats, whereas that of methyl-alpha-D-[14C(U)]-glucopyranoside was not altered. Kinetic analysis showed that the Vmax value for [14C]glycylsarcosine uptake was significantly decreased in hyperthyroid rats, whereas the Km value was not affected. The mean portal vein concentrations after intrajejunal administration of [14C]glycylsarcosine were also decreased in hyperthyroid rats. Moreover, hyperthyroidism caused a significant decrease in the expression of PEPT1 mRNA in the small intestine, whereas the expression of Na+/glucose cotransporter (SGLT1) mRNA was not changed. The level of PEPT1 protein was also decreased in the small intestine of hyperthyroid rats. These results indicate that in hyperthyroid rats, the activity and expression of PEPT1 were decreased in the small intestine.

Liver function in cats with hyperthyroidism before and after 131I therapy.

PubMed

Berent, Allyson C; Drobatz, Kenneth J; Ziemer, Lisa; Johnson, Victoria S; Ward, Cynthia R

2007-01-01

The clinical significance of high serum concentration or activity of markers of liver damage in cats with hyperthyroidism is unknown. To evaluate serum markers of liver function and damage, and ultrasonographic changes in cats with hyperthyroidism and with high liver enzymes, and to determine if abnormalities resolve after treatment with 131I. Nineteen cats with hyperthyroidism (15 with high serum activities of liver enzymes) and 4 age-matched healthy control cats. Serum bile acids, albumin, ammonia, cholesterol, and blood urea nitrogen concentrations, and activities of liver-derived enzymes, and blood glucose concentrations were measured before and after 131I therapy. These values were compared with those of cats that were euthyroid. In addition, gross liver parenchymal changes detected by abdominal ultrasonographic examination, before and after 131I therapy were evaluated. High serum liver enzyme activities were not associated with abnormalities in hepatic parenchyma and liver functional variables, regardless of the degree of increase. Serum liver enzyme activities return to normal after control of hyperthyroidism with 131I therapy. Cats with hyperthyroidism have a significantly higher serum fasting ammonia concentration than cats who were euthyroid (P = .019). Cats with hyperthyroidism also have significantly lower serum cholesterol (P = .005) and glucose (P = .002) concentrations before compared with after 131I therapy. Nine of 19 cats with hyperthyroidism had trace ketonuria. These results demonstrate that extensive examination for hepatobiliary disease in most cats with hyperthyroidism is unnecessary.

Heart rate variability and turbulence in hyperthyroidism before, during, and after treatment.

PubMed

Osman, Faizel; Franklyn, Jayne A; Daykin, Jacqueline; Chowdhary, Saqib; Holder, Roger L; Sheppard, Michael C; Gammage, Michael D

2004-08-15

Patients with subclinical and treated overt hyperthyroidism have an excess vascular mortality rate. Several symptoms and signs in overt hyperthyroidism suggest abnormality of cardiac autonomic function that may account in part for this excess mortality rate, but few studies have examined cardiac autonomic function in untreated and treated hyperthyroidism. We assessed heart rate turbulence (HRT) and time-domain parameters of heart rate variability in a large, unselected cohort of patients with overt hyperthyroidism referred to our thyroid clinic (n = 259) and compared findings with a group of normal subjects with euthyroidism (n = 440). These measures were also evaluated during antithyroid therapy (when serum-free thyroxine and triiodothyronine concentrations returned to normal but thyrotropin remained suppressed (i.e., subclinical hyperthyroidism, n = 110) and when subjects were rendered clinically and biochemically euthyroid (normal serum thyrotropin, free thyroxine and triiodothyronine concentrations, n = 219). We found that overall measures of heart rate variability and those specific for cardiac vagal modulation were attenuated in patients with overt hyperthyroidism compared with normal subjects; measurements of overall heart rate variability remained low in those with low levels of serum thyrotropin but returned to normal in patients with biochemical euthyroidism. Measurements of HRT (onset and slope) were also decreased in patients with overt hyperthyroidism, but HRT slope returned to normal values with antithyroid treatment. This study is the first to evaluate HRT in overt and treated hyperthyroidism.

Conversion of autoimmune hypothyroidism to hyperthyroidism

PubMed Central

2014-01-01

Background Graves’ disease and Hashimoto’s thyroiditis are the two autoimmune spectrum of thyroid disease. Cases of conversion from hyperthyroidism to hypothyroidism have been reported but conversion from hypothyroidism to hyperthyroidism is very rare. Although such cases have been reported rarely in the past we are now seeing such conversions from hypothyroidism to hyperthyroidism more frequently in clinical practice. Case presentation We are reporting three cases of middle aged Asian females who presented with classical symptoms of hypothyroidism and the investigations showed elevated thyroid stimulating hormone with positive thyroid antibodies. Diagnosis of autoimmune hypothyroidism was made and thyroxine replacement therapy was initiated. Patients became asymptomatic with normalization of thyroid stimulating hormone level. After few years they developed symptoms of hyperthyroidism with suppressed thyroid stimulating hormone level. Over replacement of thyroxine was considered and the dose of thyroxine was decreased, but they remain symptomatic. After gradual decrease in the dose of thyroxine it was stopped finally. Even after few months of stopping thyroxine, the symptoms of hyperthyroidism did not improve and the biochemical and imaging modalities confirmed that the patients have developed hyperthyroidism. Anti-thyroid treatment was then started and the patients became symptom free. Conclusion High index of suspicion should be there for possible conversion of hypothyroidism to hyperthyroidism if a patient with primary hypothyroidism develops persistent symptoms of hyperthyroidism. Otherwise it can be missed easily considering it as an over replacement with thyroid hormone. PMID:25086829

Biventricular Takotsubo cardiomyopathy in Graves hyperthyroidism.

PubMed

Perkins, Matthew J; Schachter, David T

2014-03-01

Graves hyperthyroidism is commonly seen in clinical practice and Takotsubo stress cardiomyopathy is an increasingly recognized cardiac complication of physical or emotional stress. We report the rare case of a patient with Graves hyperthyroidism that was complicated by severe biventricular takotsubo cardiomyopathy, which was demonstrated on heart catheterization. After appropriate pharmacologic treatment of her hyperthyroidism, she had complete resolution of her cardiomyopathy.

Metabolic and Clinical Consequences of Hyperthyroidism on Bone Density

PubMed Central

Gorka, Jagoda; Taylor-Gjevre, Regina M.

2013-01-01

In 1891, Von Recklinghausen first established the association between the development of osteoporosis in the presence of overt hyperthyroidism. Subsequent reports have demonstrated that BMD loss is common in frank hyperthyroidism, and, to a lesser extent, in subclinical presentations. With the introduction of antithyroid medication in the 1940s to control biochemical hyperthyroidism, the accompanying bone disease became less clinically apparent as hyperthyroidism was more successfully treated medically. Consequently, the impact of the above normal thyroid hormones in the pathogenesis of osteoporosis may be presently underrecognized due to the widespread effective treatments. This review aims to present the current knowledge of the consequences of hyperthyroidism on bone metabolism. The vast number of recent papers touching on this topic highlights the recognized impact of this common medical condition on bone health. Our focus in this review was to search for answers to the following questions. What is the mechanisms of action of thyroid hormones on bone metabolism? What are the clinical consequences of hyperthyroidism on BMD and fracture risk? What differences are there between men and women with thyroid disease and how does menopause change the clinical outcomes? Lastly, we report how different treatments for hyperthyroidism benefit thyroid hormone-induced osteoporosis. PMID:23970897

Thyroid hormone reduces PCSK9 and stimulates bile acid synthesis in humans[S

PubMed Central

Bonde, Ylva; Breuer, Olof; Lütjohann, Dieter; Sjöberg, Stefan; Angelin, Bo; Rudling, Mats

2014-01-01

Reduced plasma LDL-cholesterol is a hallmark of hyperthyroidism and is caused by transcriptional stimulation of LDL receptors in the liver. Here, we investigated whether thyroid hormone (TH) actions involve other mechanisms that may also account for the reduction in LDL-cholesterol, including effects on proprotein convertase subtilisin/kexin type 9 (PCSK9) and bile acid synthesis. Twenty hyperthyroid patients were studied before and after clinical normalization, and the responses to hyperthyroidism were compared with those in 14 healthy individuals after 14 days of treatment with the liver-selective TH analog eprotirome. Both hyperthyroidism and eprotirome treatment reduced circulating PCSK9, lipoprotein cholesterol, apoB and AI, and lipoprotein(a), while cholesterol synthesis was stable. Hyperthyroidism, but not eprotirome treatment, markedly increased bile acid synthesis and reduced fibroblast growth factor (FGF) 19 and dietary cholesterol absorption. Eprotirome treatment, but not hyperthyroidism, reduced plasma triglycerides. Neither hyperthyroidism nor eprotirome treatment altered insulin, glucose, or FGF21 levels. TH reduces circulating PSCK9, thereby likely contributing to lower plasma LDL-cholesterol in hyperthyroidism. TH also stimulates bile acid synthesis, although this response is not critical for its LDL-lowering effect. PMID:25172631

Hyperthyroidism in pregnancy.

PubMed

Mestman, Jorge H

2012-10-01

Successful outcome in pregnancy hyperthyroidism depends on the cause, interpretation of laboratory tests, and careful use of antithyroid drug (ATD) therapy. Planning of a pregnancy in a woman with active or past history of Graves' hyperthyroidism is mandatory in order to avoid complications. Fetal health may be affected by three factors: poor control of maternal hyperthyroidism, titer of maternal TRAb, and inappropriate use of ATD. Careful assessment of thyroid function through pregnancy and evaluation of fetal development by ultrasonography is the cornerstone for a successful outcome. In a subgroup of women previously treated with ablation therapy, those whose serum TSRAb titers remained elevated, are at risk of having a fetus/neonate with Graves' hyperthyroidism. Use of ATD during lactation is well tolerated, if recommended guidelines are followed. Women during their childbearing age with active Graves' hyperthyroidism should plan their pregnancy. Causes of hyperthyroidism in pregnancy include Graves' disease or autonomous adenoma, and transient gestational thyrotoxicosis as a consequence of excessive production of human chroionic gonadotropin by the placenta. Careful interpretation of thyroid function tests and frequent adjustment of ATD is of utmost importance in the outcome of pregnancy. Graves' hyperthyroidism may relapse early in pregnancy or at the end of the first year postpartum.

Regression of the carotid intima media thickness by propylthiouracil therapy in Graves' hyperthyroidism.

PubMed

Bilir, Cemil; Gökosmanoglu, Feyzi; Caliskan, Mustafa; Cinemre, Hakan; Akdemir, Ramazan

2012-04-01

One of the cardiovascular effects of hyperthyroidism is increased carotid intima media thickness (CIMT). The aim of this study is to investigate the CIMT in patients with Graves' hyperthyroidism and the effect of propylthiouracil (PTU) therapy on CIMT. Twenty-six patients with Graves' hyperthyroidism and 33 healthy controls were included in the study. CIMT was measured at the right and left external carotid arteries in every patient in both groups. CIMT was measured before and after the PTU therapy in patients with Graves' hyperthyroidism. There was a significant difference in CIMT between the group of Graves' hyperthyroid patients and the control group (0.72 versus 0.55 mm, P < 0.0001) at baseline. Twenty-five of 26 patients with Graves' disease were followed up for 18 months prospectively. Euthyroidism has been achieved in 21 patients. After 18 months of treatment, CIMT decreased significantly compared with the baseline values [0.84 (0.54-1.3) to 0.72 (0.50-1.2), change 0.12 mm, P < 0.001]. Graves' hyperthyroidism is associated with atherosclerosis as assessed by CIMT. Treatment of Graves' hyperthyroidism with PTU decreases the CIMT.

Atrial fibrillation associated with exogenous subclinical hyperthyroidism.

PubMed

Patanè, Salvatore; Marte, Filippo

2010-11-19

Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with coronary heart disease or mortality from cardiovascular causes but it is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. It has also been reported that increased factor X activity in patients with subclinical hyperthyroidism represents a potential hypercoagulable state. Moreover acute myocardial infarction has been reported during L-thyroxine substitution therapy. Far more common and relatively less studied is exogenous subclinical hyperthyroidism caused by L-thyroxine administration to thyroidectomized or hypothyroid patients or patients with simple or nodular goiter. We present a case of atrial fibrillation associated with exogenous subclinical hyperthyroidism, in a 72-year-old Italian woman. Also this case focuses attention on the importance of a correct evaluation of subclinical hyperthyroidism. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Endogenous subclinical hyperthyroidism and cardiovascular system: time to reconsider?

PubMed

Patanè, Salvatore; Marte, Filippo; Sturiale, Mauro

2011-05-19

Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. Exogenous sublinical hyperthyroidism is a thyroid metabolic state caused by L-thyroxine administration. Endogenous subclinical hyperthyroidism is a thyroid metabolic state in patients with autonomously functioning thyroid nodule or multinodular goiter, various forms of thyroiditis, in areas with endemic goiter and particularly in elderly subjects. Endogenous subclinical hyperthyroidism is currently the subject of numerous studies and it yet remains controversial particularly as it relates to its treatment and to cardiovascular impact nevertheless established effects have been demonstrated. Recently, acute myocardial infarction without significant coronary stenoses and recurrent acute pulmonary embolism have been reported associated with subclinical hyperthyroidism without L-thyroxine administration. So, it is very important to recognize and to treat promptly also endogenous subclinical hyperthyroidism. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Management of Hyperthyroidism during the Preconception Phase, Pregnancy, and the Postpartum Period.

PubMed

Sarkar, Sudipa; Bischoff, Lindsay A

2016-11-01

Hyperthyroidism can occur during pregnancy and the postpartum period, and the treatment of hyperthyroidism should be considered in the preconception phase. Pregnancy has multiple normal physiologic effects on thyroid hormone, which is a separate process distinct from syndromes such as transient hyperthyroidism of hyperemesis gravidarum. The rationale regarding antithyroid drug use during different stages of pregnancy is reviewed, including the literature regarding adverse neonatal outcomes such as aplasia cutis and methimazole embryopathy in the setting of first trimester maternal methimazole use. The use of treatment modalities for hyperthyroidism during pregnancy such as surgery is also discussed. Studies of maternal, fetal, and neonatal complications of hyperthyroidism are examined in this article. Moreover, the evidence regarding antithyroid drugs, specifically methimazole and propylthiouracil, during lactation is considered. Other disease conditions that can take place during pregnancy and the postpartum period such as hyperemesis gravidarum, subclinical hyperthyroidism, gestational trophoblastic disease, and postpartum thyroiditis and their treatments are also presented. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Gynecomastia as the initial manifestation of hyperthyroidism.

PubMed

Gordon, D L; Brown, J L; Emanuele, N V; Hall, L

1997-01-01

To present two new cases of gynecomastia as the initial manifestation of hyperthyroidism. We describe detailed case reports of two men with breast enlargement who were found to have hyperthyroidism, and we review the related literature. Two men sought medical assistance because of unilateral tender gynecomastia. In one of these patients, thyroid, gonadal, and prostate examinations showed normal findings at the time of initial assessment, and symptoms of hyperthyroidism developed later. In our other patient with gynecomastia, other symptoms of hyperthyroidism--for example, nervousness, irritability, palpitations, and fatigue--had been present for a prolonged period but had been considered "normal" by the patient. In both patients, the hyperthyroidism was treated with radioiodine. Breast pain disappeared in both patients, and breast enlargement disappeared in one patient and was decreased in the other patient after euthyroidism was achieved. Review of the literature disclosed only two similar cases. Because of the rarity of gynecomastia as the initial symptom of hyperthyroidism, we believe that thyroid function tests are not indicated in the workup of patients whose major complaint is gynecomastia.

Inheritable and sporadic non-autoimmune hyperthyroidism.

PubMed

Ferraz, Carolina; Paschke, Ralf

2017-03-01

Hyperthyroidism is a clinical state that results from high thyroid hormone levels which has multiple etiologies, manifestations, and potential therapies. Excluding the autoimmune Graves disease, autonomic adenomas account for the most import cause of non-autoimmune hyperthyroidism. Activating germline mutations of the TSH receptor are rare etiologies for hyperthyroidism. They can be inherited in an autosomal dominant manner (familial or hereditary, FNAH), or may occur sporadically as a de novo condition, also called: persistent sporadic congenital non-autoimmune hyperthyroidism (PSNAH). These three conditions: autonomic adenoma, FNAH and PSNAH constitute the inheritable and sporadic non-autoimmune hyperthyroidism. Particularities in epidemiology, etiology, molecular and clinical aspects of these three entities will be discussed in this review in order to guide to an accurate diagnosis allowing among others genetic counseling and presymptomatic diagnosis for the affected families. The optimal treatment based on the right diagnosis will avoid consequences of a persistent or relapsing hyperthyroidism. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Montmorillonite ameliorates hyperthyroidism of rats and mice attributed to its adsorptive effect.

PubMed

Cai, Yan; Meng, Xin-fang; Cao, Yong-xiao; Lu, Hua; Zhu, Shao-fei; Zhou, Liang-zhen

2006-12-03

The present study aims to evaluate the adsorbing effect of montmorillonite on thyroid hormone in the entero-hepatic circulation. The concentration of thyroid hormone in the serum of hyperthyroidism model rats and in solution was measured by radioimmunoassay and ultraviolet spectrometry, respectively. The body weight, temperature, and consumption of food and water were observed in hyperthyroidism model rats. Furthermore, hypoxia tolerance, sodium-pentobarbital-induced sleep time, spontaneous activities were measured on hyperthyroidism model mice after being treated with montmorillonite. Results showed that montmorillonite adsorbed thyroxin (T(4)) and triiodothyronine (T(3)) in vitro. Montmorillonite at dosage of 1.0 g/kg and 0.3 g/kg decreased thyroid hormone levels on hyperthyroidism model rats; Montmorillonite (2.0 g/kg and 0.6 g/kg) prolonged the sleep time, improved the hypoxia tolerant capacity and reduced the spontaneous activities of the hyperthyroidism model mice. These results suggest montmorillonite has anti-hyperthyroidism effect attributed to its adsorptive effect.

[Bone histomorphometry of lactating and no lactating hyperthyroid rats].

PubMed

Serakides, Rogéria; Ocarino, Natália de Melo; Magalhães, Fernanda do Carmo; Souza, Cíntia de Almeida; Leite, Eveline Dias; Freitas, Edmilson Santos de

2008-06-01

The objective of this study was to verify if hyperthyroidism potentiates the osteopenia lactational. 24 adult female rats were distributed in four groups: euthyroid no lactating (control), euthyroid lactating, hyperthyroid no lactating and hyperthyroid lactating. 20 days after gestation, all the animals were necropsied. The thoracic and lumbar vertebrae, the femur and tibia were decalcified and processed for histomorphometric analysis. The euthyroid lactating group presented intense osteopenia in the studied bones. In the hyperthyroid no lactating group, there was not any change in trabecular bone percentage in none of the analyzed bone. In the hyperthyroid lactating group, there was osteopenia in the tibia and femur, similar to the one in the euthyroid lactating group. But the trabecular bone percentage in all the vertebral bodies was significantly larger in comparison with the euthyroid lactating group. It was concluded that the hyperthyroidism does not potentiate the osteopenia lactational in female rats, but it minimizes the vertebral osteopenia once it stimulates the osteoblastic activity.

A rare cause of hyperthyroidism: functioning thyroid metastases.

PubMed

Gardner, Daphne; Ho, Su Chin

2014-10-09

Hyperthyroidism is a common medical problem that is readily treated with antithyroid medications. However, attributing the correct aetiology of hyperthyroidism alters management and outcome. We present a case of a 66-year-old woman with a seemingly common problem of hyperthyroidism associated with a goitre, which was initially attributed to a toxic nodule. However, Tc-99m pertechnetate uptake scan and thyroid-stimulating hormone receptor antibody were negative, inconsistent with a toxic nodule or Grave's disease. Her thyroid function tests proved difficult to control over the next few months. She eventually proceeded to a total thyroidectomy and histology revealed follicular variant papillary thyroid carcinoma. She was started on levothyroxine postoperatively but developed severe hyperthyroidism, revealing the cause of hyperthyroidism to be autonomously functioning thyroid metastases. Although functioning thyroid metastases are very rare, they need to be considered among the differential diagnoses of hyperthyroidism, as there are nuances in management that could alter the eventual outcome. 2014 BMJ Publishing Group Ltd.

Evaluation of dermal symptoms in hypothyroidism and hyperthyroidism.

PubMed

Razi, Ahad; Golforoushan, Farideh; Nejad, Amir Bahrami Shahla Babaee; Goldust, Mohamad

2013-06-01

Many symptoms arise in thyroid diseases. The aim of this study was to evaluate the dermal symptoms in hypothyroidism and hyperthyroidism. In this cross sectional study, 120 patients with hyperthyroidism and 50 patients suffering from hypothyroidism were studied. Cutaneous, hair and nail clinical symptoms were studied and registered in a special questionnaire. Mean age of patients suffering from hypothyroidism and hyperthyroidism were 38.24 +/- 14.45 and 25.86 +/- 14.69 years old. Dry and Coarse/rough skin were the most prevalent manifestations in the skin involvement in hypothyroidism since softness was the most prevalent ones in hyperthyroidism. Fragileness was the most prevalent symptom in patients with nail involvement in hypothyroidism since soft skin was the most prevalent ones in hyperthyroidism. Coarse/rough skin was observed more in patients with hair involvement in hypothyroidism since the most prevalent ones was separation of nail from its bed in hyperthyroidism. High prevalence of skin, hair and nail symptoms in thyroid patients, early diagnosis of the signs may be helpful in premature diagnosis and treatment of thyroid diseases.

Is hyperthyroidism underestimated in pregnancy and misdiagnosed as hyperemesis gravidarum?

PubMed

Luetic, Ana Tikvica; Miskovic, Berivoj

2010-10-01

Thyroid changes are considered to be normal events that happen as a large maternal multiorganic adjustment to pregnancy. However, hyperthyroidism occurs in pregnancy with clinical presentation similar to hyperemesis gravidarum (HG) and pregnancy itself. Moreover, 10% of women with HG will continue to have symptoms throughout the pregnancy suggesting that the underlying cause might not be elevation of human chorionic gonadotropin in the first trimester. Variable frequency of both hyperthyroidism and HG worldwide might suggest the puzzlement of inclusion criteria for both diagnoses enhanced by the alternation of thyroid hormone levels assessed in normal pregnancy. Increased number of hyperthyroidism among women population without the expected rise in gestational hyperthyroidism encouraged us for creating the hypotheses that hyperthyroidism could be underestimated in normal pregnancy and even misdiagnosed as HG. This hypothesis, if confirmed, might have beneficial clinical implications, such as better detection of hyperthyroidism in pregnancies, application of therapy when needed with the reduction of maternal or fetal consequences. Copyright 2010 Elsevier Ltd. All rights reserved.

[Classification and etiology of hyperthyroidism].

PubMed

Łacka, Katarzyna; Fraczek, Magdalena Maria

2014-03-01

The prevalence of hyperthyroidism in women is between 0.5-2% and it is 10 times less common in men. The most common causes are Graves' disease, toxic multinodular goiter, and autonomously functioning thyroid adenoma. Rare causes of hyperthyroidisms are as follow: pituitary adenoma, autoimmune thyroiditis (Hashitoxicosis), levothyroxine overdose, inadequate iodine supplementation (including amiodaron induced hyperthyroidism, iodine-based contrast media), hCG excess (pregnancy, gestational trophoblastic disease, germ-cell tumors), drug induced hyperthyroidism, differentiated thyroid carcinomas and/or their metastases, struma ovarii, and familial nonautoimmune hyperthyroidism. This article focuses on the current data of etiopathogenesis of hyperthyroidisms. Genetic factors (like HLA-DR3,CD40, CTLA-4, PTPN22, FOXP3 CD25) and thyroid specific genes (thyroglobulin, TSHR, G(s)alpha) and environmental and endogenous factors (such as age, iodine, selenium, emotional stress, smoking, gender, pregnancy, sex hormones, fetal microchimerism, fetal growth, bacterial infections, viral infections, allergies, drugs (alemtuzumab, interferon alpha, iplimumab/tremelimumab, tyrosine kinase inhibitors, denileukindiftitox, thalidomide/lenalidomide, exposition to fallout and radiotherapy) have been described.

Recurrent severe vomiting due to hyperthyroidism

PubMed Central

Chen, Li-ying; Zhou, Bo; Chen, Zhou-wen; Fang, Li-zheng

2010-01-01

Thyrotoxicosis may present in many ways; severe vomiting as a prominent symptom of thyrotoxicosis is uncommon. In this paper, we report a 24-year-old Chinese male with hyperthyroidism who presented with recurrent severe vomiting. The patient had had intermittent vomiting for seven years and had lost approximately 15 kg of weight. Gastroscopic examinations revealed chronic gastritis and one occasion peptic ulcer. He was treated with antacid and proton pump inhibitors, but his symptoms had no relief. His presenting symptoms suggested hyperthyroidism and were confirmed by laboratory data. After a month of propylthiouracil therapy, his symptoms were relieved. It should be noted that hyperthyroidism patients can have unexplained vomiting, and that hyperthyroidism may coexist with peptic ulcer in rare cases. Awareness of such atypical presentations of hyperthyroidism may help to make a correct diagnosis. PMID:20205308

Case Report: Recurrent severe vomiting due to hyperthyroidism.

PubMed

Chen, Li-ying; Zhou, Bo; Chen, Zhou-wen; Fang, Li-zheng

2010-03-01

Thyrotoxicosis may present in many ways; severe vomiting as a prominent symptom of thyrotoxicosis is uncommon. In this paper, we report a 24-year-old Chinese male with hyperthyroidism who presented with recurrent severe vomiting. The patient had had intermittent vomiting for seven years and had lost approximately 15 kg of weight. Gastroscopic examinations revealed chronic gastritis and one occasion peptic ulcer. He was treated with antacid and proton pump inhibitors, but his symptoms had no relief. His presenting symptoms suggested hyperthyroidism and were confirmed by laboratory data. After a month of propylthiouracil therapy, his symptoms were relieved. It should be noted that hyperthyroidism patients can have unexplained vomiting, and that hyperthyroidism may coexist with peptic ulcer in rare cases. Awareness of such atypical presentations of hyperthyroidism may help to make a correct diagnosis.

Hyperthyroidism in adults: variable clinical presentations and approaches to diagnosis.

PubMed

Knudson, P B

1995-01-01

Hyperthyroidism is a disease that has various symptoms and can present in many ways. In the elderly patient hyperthyroidism often is not expressed in the classical manner. A case report of a middle-aged man who had hyperthyroidism with only one symptom is detailed. A literature review utilizing MEDLINE files from 1988 to the present, as well as current textbooks of medicine and endocrinology, was used to prepare this report. Keywords for the search were "hyperthyroidism," "symptoms," "unintentional weight loss," and "differential diagnosis." The clinical presentation of hyperthyroidism can vary from almost asymptomatic to apathetic in appearance to a marked hyperdynamic physiologic response. Family physicians must be well informed of this variation in disease expression. Overlooking the diagnosis of this relatively easily treated condition can be detrimental to patient care and expensive.

Bone mineral density and metabolic indices in hyperthyroidism.

PubMed

Al-Nuaim, A; El-Desouki, M; Sulimani, R; Mohammadiah, M

1991-09-01

Hyperthyroidism can alter bone metabolism by increasing both bone resorption and formation. The increase in bone resorption predominates, leading to a decrease in bone mass. To assess the effect of hyperthyroidism on bone and mineral metabolism, we measured bone density using single photon absorptiometry in 30 untreated hyperthyroid patients. Patients were categorized into three groups based on sex and alkaline phosphatase levels: 44 sex- and age-matched subjects were used as controls. Bone densities were significanlty lower in all patient groups compared with controls. Alkaline phosphatase was found to be a useful marker for assessing severity of bone disease in hyperthyroid patients as there is significant bone density among patients with higher alkaline phosphatase value. Hyperthyroidism should be considered in the differential diagnosis of unexplained alkaline phophatase activity.

Acute myocardial infarction without significant coronary stenoses associated with endogenous subclinical hyperthyroidism.

PubMed

Patanè, Salvatore; Marte, Filippo; Sturiale, Mauro

2012-04-05

Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with coronary heart disease or mortality from cardiovascular causes but it is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. Nowadays, there is growing interest regarding endogenous sublinical hyperthyroidism and the cardiovascular system. We present a case of acute myocardial infarction without significant coronary stenoses in a 75-year-old Italian woman with endogenous subclinical hyperthyroidism. Also this case focuses attention on the importance of a correct evaluation of endogenous subclinical hyperthyroidism. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Factitious hyperthyroidism

MedlinePlus

... by taking too much thyroid hormone medicine for hypothyroidism . This is called factitious hyperthyroidism. When this occurs ... D.A.M. Editorial team. Hyperthyroidism Read more Hypothyroidism Read more NIH MedlinePlus Magazine Read more A. ...

Surgical management of hyperthyroidism.

PubMed

Quérat, C; Germain, N; Dumollard, J-M; Estour, B; Peoc'h, M; Prades, J-M

2015-04-01

Hyperthyroidism includes several clinical and histopathological situations. Surgery is commonly indicated after failure of medical treatment. The aim of this study was to analyze the indications and complications of surgery as well as endocrine results. Patients operated on for hyperthyroidism between 2004 and 2012 were included in a retrospective study. Total thyroidectomy was performed for Graves' disease, toxic multinodular goiter and amiodarone-associated thyrotoxicosis; patients with toxic nodule underwent hemithyroidectomy. Pathologic analysis assessed surgical specimens; postoperative complications and resolution of hyperthyroidism were noted. Two hundred patients from 15 to 83 years old were included. One hundred and eighty-eight underwent primary surgery and 12 were re-operated for recurrent goiter (6 with subtotal thyroidectomy for multinodular goiter 25 years previously; 6 with hemithyroidectomy for solitary nodule 15 years previously). Eighty-two patients suffered from toxic multinodular goiter, 78 from Graves' disease, 35 from solitary toxic nodules and 5 from amiodarone-associated thyrotoxicosis. Fourteen papillary carcinomas (including 11 papillary microcarcinomas) and 34 healthy parathyroid glands (17%) were identified in the pathological specimens. Postoperative complications comprised 4% permanent recurrent laryngeal nerve palsy (1 year follow-up), 9% hematoma requiring surgical revision, and 3% definitive hypocalcemia. Normalization of thyroid hormone levels was observed in 198 patients. Two recurrences occurred due to incomplete resection (1 case of Graves' disease and 1 intrathoracic toxic goiter that occurred respectively 18 and 5 months after resection). Postoperative complications were more frequent in multinodular goiter (23%) than in Graves' disease (13%) (ns: P>0.05). Surgical management of hyperthyroidism enables good endocrinal control if surgery is complete. Patients need to be fully informed of all possible postoperative complications that could occur, especially vocal ones. Long-term follow-up is necessary to detect recurrence, which can occur more than 20 years after partial thyroidectomy surgery. Surgery allows early diagnosis of 12.5% of papillary carcinomas. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Prevalence and risk factors for hyperthyroidism in Irish cats from the greater Dublin area.

PubMed

Bree, Laura; Gallagher, Barbara A; Shiel, Robert E; Mooney, Carmel T

2018-01-01

Hyperthyroidism is common in older cats. Prevalence varies geographically, but is anecdotally considered low in Ireland. The aim of this study was to document prevalence of hyperthyroidism in older cats in the greater Dublin area of Ireland and to assess environmental and clinical associations for development and identification of the disease. Primary-care veterinary practices were requested to select cats aged 10 years or older where blood sampling was being performed for health screening or clinical investigations. Surplus serum/plasma samples were submitted to University College Dublin Diagnostic Endocrine Laboratory for total thyroxine (T 4 ) measurement. Cats were classified as hyperthyroid, equivocal or euthyroid based on a total T 4 concentration (reference interval, 15-60 nmol/L), of >60 nmol/L, 30-60 nmol/L or <30 nmol/L, respectively. Simultaneous free T 4 or repeat (after 4-6 weeks) total T 4 measurement was recommended in all equivocal cases. Animals receiving treatment for hyperthyroidism were excluded. A questionnaire completed by the client and veterinarian detailing historical and physical information was also required. Associations between categorical variables were analysed by Chi-square or Fisher's exact test and odds ratio (OR) calculated. A P value of <0.05 was considered statistically significant. Samples were submitted from 507 cats including 107 (21.1%) hyperthyroid, 54 (10.6%) equivocal and 346 (68.2%) euthyroid. The presence of goitre ( P  < 0.0001), tachypnoea ( P  = 0.0378), tachycardia ( P  = 0.002), polyphagia ( P  = 0.0003) and weight loss ( P  < 0.0001) were significantly associated with hyperthyroidism. Cats with goitre were more likely to be diagnosed as hyperthyroid [OR 2.85, (95% CI 1.75-4.62] compared to those without. However, goitre was only palpated in 40 of 102 (39.2%) hyperthyroid cats. Increasing age was the only significant ( P  < 0.002) risk factor for development of hyperthyroidism. A relationship between hyperthyroidism and sex, breed, lifestyle, parasite control, vaccination status or feeding habits was not identified. Hyperthyroidism is not uncommon in Irish cats. Age was the only significant risk factor for its development. The high proportion of hyperthyroid cats without palpable goitre (> 60%) may reflect failure to detect goitre and account for the perceived low prevalence of this condition in Ireland.

The role of early visual cortex in visual short-term memory and visual attention.

PubMed

Offen, Shani; Schluppeck, Denis; Heeger, David J

2009-06-01

We measured cortical activity with functional magnetic resonance imaging to probe the involvement of early visual cortex in visual short-term memory and visual attention. In four experimental tasks, human subjects viewed two visual stimuli separated by a variable delay period. The tasks placed differential demands on short-term memory and attention, but the stimuli were visually identical until after the delay period. Early visual cortex exhibited sustained responses throughout the delay when subjects performed attention-demanding tasks, but delay-period activity was not distinguishable from zero when subjects performed a task that required short-term memory. This dissociation reveals different computational mechanisms underlying the two processes.

Morbidity before and after the Diagnosis of Hyperthyroidism: A Nationwide Register-Based Study

PubMed Central

Brandt, Frans; Thvilum, Marianne; Almind, Dorthe; Christensen, Kaare; Green, Anders; Hegedüs, Laszlo; Brix, Thomas Heiberg

2013-01-01

Background Hyperthyroidism has been linked with different morbidities, like atrial fibrillation, stroke and diabetes mellitus. However, our knowledge regarding the extent and temporal relation between hyperthyroidism and other diseases is fragmented. Here, we aimed at evaluating various morbidities before and after the diagnosis of hyperthyroidism. Methods Observational cohort study. From nationwide Danish health registers 2631 hyperthyroid singletons and 375 twin pairs discordant for hyperthyroidism were identified and followed for an average of 6 years (range 0–13). Data on the occurrence of cardiovascular diseases, lung diseases, diabetes mellitus, rheumatic diseases and malignant diseases was obtained by person-to-person record linkage with the National Danish Patient Register and/or the Danish National Prescription Registry (lung diseases and diabetes mellitus). Logistic and Cox regression models were used to assess the risk of morbidity before and after the diagnosis of hyperthyroidism, respectively. All Cox regression analyses were adjusted for the degree of co-morbidity preceding the diagnosis of hyperthyroidism, using the Charlson score. Results Hyperthyroid individuals had a significantly higher risk of being diagnosed with cardiovascular diseases (odds ratio (OR) 1.65; 95% confidence interval (CI): 1.45–1.87), lung diseases (OR 1.53; 95% CI: 1.29–1.60), and diabetes mellitus (OR 1.43, 95% CI: 1.20–1.72), but not with malignant diseases (OR 1.16, 95% CI: 0.99–1.36) prior to the diagnosis of hyperthyroidism. After the diagnosis of hyperthyroidism, subjects had a significantly higher risk of being diagnosed with cardiovascular diseases (hazard ratio (HR) 1.34; 95% CI: 1.15–1.56), lung diseases (HR 1.28; 95% CI: 1.10–1.49), and diabetes mellitus (HR 1.46; 95% CI: 1.16–1.84), but not with rheumatic diseases (HR 1.39, 95% CI: 0.92–2.09) or malignant diseases (HR 1.18, 95% CI 0.97–1.42). Conclusions We demonstrate a significantly increased burden of morbidity, both before and after the diagnosis of hyperthyroidism. PMID:23818961

[Iatrogenic hyperthyroidism secondary to weight loss medication. Predictive factors for their precocious detention].

PubMed

Goday, A; Recasens, A; Manresa, J M; Vila, J; Moix, S

1998-05-01

To establish the differential clinical characteristics between the Iatrogenic hyperthyroidism for not conventional medication for obesity treatment (weight losers) and the endogenous by Graves Basedow disease. Observational and analytical study, populational based, in the one which prospectively were compared cases with Iatrogenic hyperthyroidism (secondary to weight losers) with those with endogenous hyperthyroidism (Graves Basedow disease) as controls. Consisted of the variable clinical record of 100 correlative patients that consulted in specialized attention of endocrinology for Iatrogenic hyperthyroidism secondary to weight losers and for Graves Basedow disease. The differences observed between Iatrogenic hyperthyroidism (secondary to weight losers) (n = 43) as compared to endogenous hyperthyroidism (Graves Basedow disease) (n = 57) were: smaller age (31.8 +/- 10 as compared to 37.8 +/- 12.6 years), greater body mass index (27.6 +/- 7.2 as compared to 23.4 +/- 3.1), smaller goiter frequency (16.3% as compared to 84.2%) as well as absence of signs of ophthalmopathy (0% as compared to 57.9%). Both groups had low levels of TSH, and the difference rests in the values of free T4, low in the first group and increased in the endogenous hyperthyroidism. The odds ratio were: IMC > 27: 3.92 (0.91-16.72), age < 33 years: 5.58 (1.42-21.99), absence of goiter: 23.29 (6.39-84.85). The precedent of weight losers use was not selective of the first group, being detected in a 12.3% of cases of endogenous hyperthyroidism, though in periods of time remoter in relationship to the beginning of the clinic. In the differential diagnosis of a case of hyperthyroidism, it can be suspected Iatrogenic hyperthyroidism (secondary to weight losers) for medication for the obesity in patients of the feminine sex with overweight, without previous or familiar history of thyroid disease, and in those which in the physical exploration is not verified goiter neither ophthalmopathy.

Excess Mortality in Hyperthyroidism: The Influence of Preexisting Comorbidity and Genetic Confounding: A Danish Nationwide Register-Based Cohort Study of Twins and Singletons

PubMed Central

Brandt, Frans; Almind, Dorthe; Christensen, Kaare; Green, Anders; Brix, Thomas Heiberg

2012-01-01

Context: Hyperthyroidism is associated with severe comorbidity, such as stroke, and seems to confer increased mortality. However, it is unknown whether this increased mortality is explained by hyperthyroidism per se, comorbidity, and/or genetic confounding. Objective: The objective of the study was to investigate whether hyperthyroidism is associated with an increased mortality and, if so, whether the association is influenced by comorbidity and/or genetic confounding. Methods: This was an observational cohort study using record-linkage data from nationwide Danish health registers. We identified 4850 singletons and 926 twins from same-sex pairs diagnosed with hyperthyroidism. Each case was matched with four controls for age and gender. The Charlson score was calculated from discharge diagnoses on an individual level to measure comorbidity. Cases and controls were followed up for a mean of 10 yr (range 0–31 yr), and the hazard ratio (HR) for mortality was calculated using Cox regression analyses. Results: In singletons there was a significantly higher mortality in individuals diagnosed with hyperthyroidism than in controls [HR 1.37; 95% confidence interval (CI) 1.30–1.46]. This persisted after adjustment for preexisting comorbidity (HR 1,28; 95% CI 1.21–1.36). In twin pairs discordant for hyperthyroidism (625 pairs), the twin with hyperthyroidism had an increased mortality compared with the corresponding cotwin (HR 1.43; 95% CI 1.09–1.88). However, this was found only in dizygotic pairs (HR 1.80; 95% CI 1.27–2.55) but not in monozygotic pairs (HR 0.95; 95% CI 0.60–1.50). Conclusions: Hyperthyroidism is associated with an increased mortality independent of preexisting comorbidity. The study of twin pairs discordant for hyperthyroidism suggests that genetic confounding influences the association between hyperthyroidism and mortality. PMID:22930783

Prevalence of and risk factors for feline hyperthyroidism among a clinic population in Southern Germany.

PubMed

Köhler, Ines; Ballhausen, Bianca Desiree; Stockhaus, Christian; Hartmann, Katrin; Wehner, Astrid

2016-06-16

Feline hyperthyroidism is a common endocrine disorder in older cats. Previous studies have identified nutritional imbalances, thyroid-disrupting compounds, increasing age and being non-purebred as risk factors but the final trigger remains unknown. The purpose of this prospective study was a) to determine the hospital prevalence of hyperthyroidism in a client-owned cat population in Southern Germany, b) to exploit how frequently hyperthyroidism was diagnosed after the initial clinical suspicion and c) to determine putative intrinsic and extrinsic risk factors from the cats' signalment and a questionnaire analysis, respectively. Total thyroxine (T4) was measured in sera of 495 cats ≥ 8 years. Prevalence was calculated with a 95% confidence interval (95% CI) Association between signalment and hyperthyroidism was analysed by Student's unpaired-t-test, chi-square test and Mann-Whitney U-test. Level of significance was set at 0.05. Multivariate logistic regression model was used to determine extrinsic risk factors. Sixty-one cats were diagnosed with hyperthyroidism leading to a prevalence of 12.3% (95% CI: 9.7-15.5). Older (p < 0.001) female cats (p = 0.019; odds ratio 1.9) were significantly more often affected. Domestic shorthair and domestic longhair cats were more likely hyperthyroid than purebred cats (p = 0.016). In 164 cats hyperthyroidism was considered a differential diagnosis and was verified in 20.1% (33/164). In 2.4% (12/495) cases the elevated T4 was an incidental finding. Hyperthyroid cats were more likely to be fed with moist cat food from aluminum tins (p < 0.013) compared to non-hyperthyroid cats. Older, female non-purebred cats are predisposed to hyperthyroidism which is frequently diagnosed after the initial clinical suspicion leading to a prevalence of 12.3% among the study population. Components of the aluminum tins or the moist food itself or both may play a role in the etiopathogenesis.

The Role of PDH Inhibition in the Development of Hypertrophy in the Hyperthyroid Rat Heart: A Combined MRI and Hyperpolarized MRS Study

PubMed Central

Atherton, Helen J.; Dodd, Michael S.; Heather, Lisa C.; Schroeder, Marie A.; Griffin, Julian L.; Radda, George K.; Clarke, Kieran; Tyler, Damian J.

2015-01-01

Background Hyperthyroidism increases heart rate, contractility and cardiac output, as well as metabolic rate. It is also accompanied by alterations in the regulation of cardiac substrate utilisation. Specifically, hyperthyroidism increases the ex vivo activity of pyruvate dehydrogenase kinase (PDK), thereby inhibiting glucose oxidation via pyruvate dehydrogenase (PDH). Cardiac hypertrophy is another effect of hyperthyroidism, with an increase in the abundance of mitochondria. Although the hypertrophy is initially beneficial, it can eventually lead to heart failure. The aim of this study was to use hyperpolarized magnetic resonance spectroscopy (MRS) to investigate the rate and regulation of in vivo pyruvate dehydrogenase (PDH) flux in the hyperthyroid heart, and to establish whether modulation of flux through PDH would alter cardiac hypertrophy. Methods & Results Hyperthyroidism was induced in 18 male Wistar rats with 7 daily intraperitoneal injections of freshly prepared triiodothyronine (T3; 0.2 mg/kg/day). In vivo PDH flux, assessed using hyperpolarized MRS, was reduced by 59% in hyperthyroid animals (0.0022 ± 0.0002 s−1 vs 0.0055 ± 0.0005 s−1, P = 0.0003) and this reduction was completely reversed by both acute and chronic delivery of the PDK inhibitor, dichloroacetic acid (DCA). Hyperpolarized [2-13C]pyruvate was also used to evaluate Krebs cycle metabolism and demonstrated a unique marker of anaplerosis, the level of which was significantly increased in the hyperthyroid heart. Cine MRI showed that chronic DCA treatment significantly reduced the hypertrophy observed in hyperthyroid animals (100 ± 20 mg vs 200 ± 30 mg; P = 0.04) despite no change to the increase observed in cardiac output. Conclusions This work has demonstrated that inhibition of glucose oxidation in the hyperthyroid heart in vivo is PDK mediated. Relieving this inhibition can increase the metabolic flexibility of the hyperthyroid heart and reduce the level of hypertrophy that develops whilst maintaining the increased cardiac output required to meet the higher systemic metabolic demand. PMID:21606392

Breed, Coat Color, and Hair Length as Risk Factors for Hyperthyroidism in Cats.

PubMed

Crossley, V J; Debnath, A; Chang, Y M; Fowkes, R C; Elliott, J; Syme, H M

2017-07-01

Hyperthyroidism is very common in older cats, but the etiopathogenesis is poorly understood. Decreased risk of hyperthyroidism has been reported in certain colorpoint breeds, and this observation previously has been hypothesized to result from relatively greater tyrosine availability for thyroid hormone production because of limited ability to convert tyrosine to melanin pigment. However, studies investigating a potential link between coat pigmentation and risk of hyperthyroidism are limited. To identify associations between coat phenotype and hyperthyroidism by investigation of breed, coat color, and hair length as risk factors for the disease. Data were used from 4,705 cats aged ≥10 years, referred to a single veterinary teaching hospital (2006-2014) in the United Kingdom. Retrospective, epidemiological, cross-sectional study using Bayesian multivariable logistic regression to assess risk factors for hyperthyroidism. Burmese (odds ratio [OR], 0.01; 0.00-0.23; P = .004), Tonkinese (OR, 0.05; 0.00-0.95; P = .046), Persian (OR, 0.21; 0.10-0.44; P < .001), Siamese (OR, 0.27; 0.12-0.61; P = .002), Abyssinian (OR, 0.04; 0.00-0.74; P = .031), and British shorthair (OR, 0.47; 0.28-0.79; P = .004) breeds had decreased risk of hyperthyroidism compared to domestic shorthairs. Longhaired, nonpurebred cats (OR, 1.30; 1.03-1.64; P = .028) were at increased risk of hyperthyroidism. Coat color/pattern was not associated with hyperthyroidism in nonpurebred cats. We identified decreased risk of hyperthyroidism in the Tonkinese, Abyssinian, and British shorthair breeds, identified an association between risk of hyperthyroidism and hair length, and confirmed decreased risk in Burmese, Siamese, and Persian breeds. Additional studies are warranted to further investigate these findings. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Optimization of (131)I doses for the treatment of hyperthyroidism.

PubMed

Araujo, F; Rebelo, A M O; Pereira, A C; Moura, M B; Lucena, E A; Dantas, A L A; Dantas, B M; Corbo, R

2009-11-15

Several methods can be used to determine the activity of (131)I in the treatment of hyperthyroidism. However, many of them do not consider all the parameters necessary for optimum dose calculation. The relationship between the dose absorbed by the thyroid and the activity administered depends basically on three parameters: organ mass, iodine uptake and effective half-life of iodine in the thyroid. Such parameters should be individually determined for each patient in order to optimize the administered activity. The objective of this work is to develop a methodology for individualized treatment with (131)I in patients with hyperthyroidism of the Grave's Disease. A neck-thyroid phantom developed at the IRD was used to calibrate a scintillation camera and a uptake probe SCT-13004 at the Nuclear Medicine Center of the University Hospital of Rio de Janeiro and a uptake probe SCT-13002, available at the Nuclear Medicine Institute in Goiânia. The biokinetic parameters were determined based on measurements performed in eight voluntary patients. It is concluded that the use of the equipment available at the hospital (scintillation camera and uptake probe) has shown to be a suitable and feasible procedure for dose optimization in terms of effectiveness, simplicity and cost.

Changes of TSH-Stimulation Blocking Antibody (TSBAb) and Thyroid Stimulating Antibody (TSAb) Over 10 Years in 34 TSBAb-Positive Patients with Hypothyroidism and in 98 TSAb-Positive Graves' Patients with Hyperthyroidism: Reevaluation of TSBAb and TSAb in TSH-Receptor-Antibody (TRAb)-Positive Patients

PubMed Central

Takasu, Nobuyuki; Matsushita, Mina

2012-01-01

Two TRAbs: TSBAb and TSAb. TSBAb causes hypothyroidism. TSAb causes Graves' hyperthyroidism. TSBAb and TSAb block TSH-binding to cells as TRAb, measured as TSH-binding inhibitory immunoglobulin (TBII). We reevaluate TSBAb and TSAb. We studied TSBAb, TSAb, and TBII over 10 years in 34 TSBAb-positives with hypothyroidism and in 98 TSAb-positives with hyperthyroidism. Half of the 34 TSBAb-positives with hypothyroidism continued to have persistently positive TSBAb, continued to have hypothyroidism, and did not recover from hypothyroidism. Ten of the 98 TSAb-positives with hyperthyroidism continued to have positive TSAb and continued to have hyperthyroidism. TSBAb had disappeared in 15 of the 34 TSBAb-positives with hypothyroidism. With the disappearance of TSBAb, recovery from hypothyroidism was noted in 13 (87%) of the 15 patients. TSAb had disappeared in 73 of the 98 TSAb-positives with hyperthyroidism. With the disappearance of TSAb, remissions of hyperthyroidism were noted in 60 (82%) of the 73. Two of the 34 TSBAb-positives with hypothyroidism developed TSAb-positive Graves' hyperthyroidism. Two of the 98 TSAb-positive Graves' patients with hyperthyroidism developed TSBAb-positive hypothyroidism. TSBAb and TSAb are TRAbs. TSBAb-hypothyroidism and TSAb-hyperthyroidism may be two aspects of one disease (TRAb disease). Two forms of autoimmune thyroiditis: atrophic and goitrous. We followed 34 TSBAb-positive patients with hypothyroidism (24 atrophic and 10 goitrous) over 10 years. All of the 10 TSBAb-positive goitrous patients recovered from hypothyroidism and 19 (79%) of the 24 TSBAb-positive atrophic patients continued to have hypothyroidism. PMID:22655217

Smoking and other lifestyle factors and the risk of Graves' hyperthyroidism.

PubMed

Holm, Ingrid A; Manson, Joann E; Michels, Karin B; Alexander, Erik K; Willett, Walter C; Utiger, Robert D

2005-07-25

Hyperthyroidism caused by Graves' disease is common in women, yet little is known about risk factors for the disease. We sought to determine whether lifestyle factors, including smoking, alcohol consumption, physical activity level, and body mass index, are risk factors for Graves' hyperthyroidism. This analysis was conducted using data from the Nurses' Health Study II, among 115109 women aged 25 to 42 at entry. Incident reports of women with Graves' hyperthyroidism, confirmed to have the disorder, were included. During 1 328 270 person-years of follow-up, incident diagnoses of Graves' hyperthyroidism were confirmed in 543 women; the 12-year incidence was 4.6 per 1000 women. Cigarette smoking was a predictor of Graves' hyperthyroidism. The hazard ratio among current smokers was 1.93 (95% confidence interval [CI], 1.54-2.43), and among past smokers it was 1.27 (95% CI, 1.03-1.56), after adjusting for recent pregnancy, parity, and other variables. Among current smokers, the hazard ratio increased with the intensity of smoking and was 2.63 (95% CI, 1.71-4.04) among women who smoked 25 or more cigarettes daily. Obesity was associated with a decreased risk of Graves' hyperthyroidism. The hazard ratio for the disorder among women with a body mass index of 30 kg/m(2) or higher was 0.68 (95% CI, 0.49-0.92). Alcohol intake and physical activity level were not associated with risk of Graves' hyperthyroidism. Smoking is a risk factor for Graves' hyperthyroidism in women. Obesity may be associated with a reduced risk, although weight loss as the first manifestation of hyperthyroidism cannot be excluded.

A case-control study of the association between ulcerative colitis and hyperthyroidism in an Asian population.

PubMed

Tsai, Ming-Chieh; Lin, Herng-Ching; Lee, Cha-Ze

2017-06-01

Ulcerative colitis (UC) is a chronic relapsing inflammatory disease with significant clinical diversity. However, the aetiology, pathogenesis and optimal treatment of UC remain unclear. The purpose of this case-control study was to investigate the association between previously diagnosed hyperthyroidism and UC using a large population-based data set in Taiwan. The data for this population-based case-control study were retrieved from the Taiwan Longitudinal Health Insurance Database 2005. We included 2709 patients with UC as cases and 8127 sex- and age-matched patients without UC as controls. A conditional logistic regression analysis was conducted to compute the odds ratio (OR) and corresponding 95% confidence interval (CI) for the association between UC and prior hyperthyroidism. We found that, in total, 327 of the 10 836 sampled patients (3.02%) had previously been diagnosed with hyperthyroidism. There was a higher proportion of prior hyperthyroidism among cases than controls (4.10% vs 2.66%, P<.001). A conditional logistic regression showed that the OR of prior hyperthyroidism was 1.57 (95% CI=1.24-1.98) compared to controls. Similarly, after adjusting for monthly income, geographic location and urbanization level, cases were still more likely to have previously been diagnosed with hyperthyroidism than controls (OR=1.61, 95% CI=1.27-2.05). Furthermore, we analysed the ORs of prior hyperthyroidism between cases and controls according to age group. We found that of the youngest group of sampled patients (18-39 years), cases had the greatest adjusted OR for having previously been diagnosed with hyperthyroidism than controls (OR=1.98, 95% CI=1.04-3.79). This study demonstrated an association between UC and hyperthyroidism. © 2017 John Wiley & Sons Ltd.

HYPERTHYROIDISM AND HYPERPROLACTINEMIA: IS THERE ANY ASSOCIATION?

PubMed

Sanjari, Mojgan; Safi, Zohreh; Tahroodi, Khatereh Mohammadi

2016-12-01

To compare the serum prolactin level in hyperthyroid and normal control females. Hyperthyroidism is a common disease. Although a direct association has been demonstrated between hypothyroidism and increased prolactin levels, this association has not been established for hyperthyroidism. Cross-sectional study in cases and control groups. Control subjects were chosen from those participating in the Kerman Coronary Artery Disease Risk Factors study. To select the cases, all women referred to the laboratories of Kerman with a thyroid-stimulating hormone (TSH) level ≤0.5 mIU/L who met the inclusion criteria were entered in the study. A total of 231 women aged 15 to 50 years were enrolled. The case group included 71 hyperthyroid women, and the control group included 160 women with normal thyroid function matched by age. The mean (SD) serum level of prolactin was 16.56 (0.97) ng/mL (95% confidence interval [CI], 15.41 ng/mL to 15.71 ng/mL) in the controls and 23.07 (1.49) ng/mL (95% CI, 22.7 ng/mL to 23.4 ng/mL) in the case subjects. Hyperprolactinemia was more common in the hyperthyroid group (16.5 [0.97] ng/mL versus 23.07 [1.49] ng/mL; P<.001). The prolactin level decreased with age. Hyperthyroidism and estradiol increased the prolactin level. After adjusting for age and estradiol, hyperthyroidism increased the serum prolactin level (P<.001). The results of this study revealed that hyperprolactinemia is more frequent in hyperthyroid females. Serum prolactin level can be increased in hyperthyroidism. PRL = prolactin T4 = thyroxine TRH = thyrotropin-releasing hormone TSH = thyroid-stimulating hormone.

Requirement definition of passenger motor transport enterprises for spare parts by method of short-term combined forecasting

NASA Astrophysics Data System (ADS)

Bulatov, S. V.

2018-05-01

The article considers the method of short-term combined forecasting, which includes theoretical and experimental estimates of the need for details of units and assemblies, which allows obtaining the optimum number of spare parts necessary for rolling stock operation without downtime in repair areas.

Program level evaluation of ASAP diagnosis, referral and rehabilitation efforts. Volume 4, Development of the short term rehabilitation (STR) study

DOT National Transportation Integrated Search

1976-09-01

The present report discusses the development, implementation, and current status of the Short Term Rehabilitation (STR) Study initiates by the NHTSA in 1974. Experimental designs employed by each of the 11 ASAP/STR sites for the assignment of mid-ran...

Analysis of left ventricular function of the mouse heart during experimentally induced hyperthyroidism and recovery.

PubMed

Hübner, Neele Saskia; Merkle, Annette; Jung, Bernd; von Elverfeldt, Dominik; Harsan, Laura-Adela

2015-01-01

Many of the clinical manifestations of hyperthyroidism are due to the ability of thyroid hormones to alter myocardial contractility and cardiovascular hemodynamics, leading to cardiovascular impairment. In contrast, recent studies highlight also the potential beneficial effects of thyroid hormone administration for clinical or preclinical treatment of different diseases such as atherosclerosis, obesity and diabetes or as a new therapeutic approach in demyelinating disorders. In these contexts and in the view of developing thyroid hormone-based therapeutic strategies, it is, however, important to analyze undesirable secondary effects on the heart. Animal models of experimentally induced hyperthyroidism therefore represent important tools for investigating and monitoring changes of cardiac function. In our present study we use high-field cardiac MRI to monitor and follow-up longitudinally the effects of prolonged thyroid hormone (triiodothyronine) administration focusing on murine left ventricular function. Using a 9.4 T small horizontal bore animal scanner, cinematographic MRI was used to analyze changes in ejection fraction, wall thickening, systolic index and fractional shortening. Cardiac MRI investigations were performed after sustained cycles of triiodothyronine administration and treatment arrest in adolescent (8 week old) and adult (24 week old) female C57Bl/6 N mice. Triiodothyronine supplementation of 3 weeks led to an impairment of cardiac performance with a decline in ejection fraction, wall thickening, systolic index and fractional shortening in both age groups but with a higher extent in the group of adolescent mice. However, after a hormonal treatment cessation of 3 weeks, only young mice are able to partly restore cardiac performance in contrast to adult mice lacking this recovery potential and therefore indicating a presence of chronically developed heart pathology. Copyright © 2014 John Wiley & Sons, Ltd.

Causes of anorexia in untreated hyperthyroidism: a prospective study

PubMed Central

Dai, W.; Meng, X.

2000-01-01

Seventeen consecutive patients (mean (SD) 46 (11) years) with untreated hyperthyroidism and anorexia and 29 patients (35 (9) years) with untreated hyperthyroidism without anorexia were studied. The study was conducted at the thyroid clinic of the PUMC Hospital, Beijing, China from March to August 1997. The patients' ages, serum free calcium, liver function and emotional state, specifically the level of anxiety (using the self anxiety scale, Chinese version), were compared before and/or after antithyroid drug treatment in the two groups. This prospective study suggested that the causes of anorexia in untreated hyperthyroidism are complicated. Older age, abnormal liver function, and the level of anxiety are significantly related to anorexia in untreated hyperthyroidism, but hypercalcaemia was not confirmed to be related to anorexia in the study.


Keywords: hypercalcaemia; hyperthyroidism; anorexia; anxiety PMID:10775283

[Neonatal hyperthyroidism: a case report and literature review].

PubMed

Li, Ning; Li, Xiao-Hua; Yao, Ying-Min

2013-10-01

We report a case of neonatal thyrotoxicosis with concurrent respiratory failure in an infant born to a mother with Graves' disease and review the published literature describing neonatal hyperthyroidism. The male infant who was born by spontaneous delivery at 35 weeks of gestational age presented with fever, tachycardia and tachypnea at rest on day 11 after birth, and developed severe apnea on day 14. Thyroid function studies revealed hyperthyroidism in the infant, and his mother was confirmed to have Grave's disease during pregnancy. Literature review showed that among the 33 infants with similar conditions, tachycardia, tachypnea and poor weight gain were the most distinct clinical features of congenital hyperthyroidism. Accurate diagnosis of Graves' disease in the mother during pregnancy and awareness of the clinical presentations of neonatal hyperthyroidism are key to reducing missed diagnosis or misdiagnosis of neonatal hyperthyroidism.

Hypothalamic mTOR pathway mediates thyroid hormone-induced hyperphagia in hyperthyroidism.

PubMed

Varela, Luis; Martínez-Sánchez, Noelia; Gallego, Rosalía; Vázquez, María J; Roa, Juan; Gándara, Marina; Schoenmakers, Erik; Nogueiras, Rubén; Chatterjee, Krishna; Tena-Sempere, Manuel; Diéguez, Carlos; López, Miguel

2012-06-01

Hyperthyroidism is characterized in rats by increased energy expenditure and marked hyperphagia. Alterations of thermogenesis linked to hyperthyroidism are associated with dysregulation of hypothalamic AMPK and fatty acid metabolism; however, the central mechanisms mediating hyperthyroidism-induced hyperphagia remain largely unclear. Here, we demonstrate that hyperthyroid rats exhibit marked up-regulation of the hypothalamic mammalian target of rapamycin (mTOR) signalling pathway associated with increased mRNA levels of agouti-related protein (AgRP) and neuropeptide Y (NPY), and decreased mRNA levels of pro-opiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus (ARC), an area where mTOR co-localizes with thyroid hormone receptor-α (TRα). Central administration of thyroid hormone (T3) or genetic activation of thyroid hormone signalling in the ARC recapitulated hyperthyroidism effects on feeding and the mTOR pathway. In turn, central inhibition of mTOR signalling with rapamycin in hyperthyroid rats reversed hyperphagia and normalized the expression of ARC-derived neuropeptides, resulting in substantial body weight loss. The data indicate that in the hyperthyroid state, increased feeding is associated with thyroid hormone-induced up-regulation of mTOR signalling. Furthermore, our findings that different neuronal modulations influence food intake and energy expenditure in hyperthyroidism pave the way for a more rational design of specific and selective therapeutic compounds aimed at reversing the metabolic consequences of this disease. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Both Hypothyroidism and Hyperthyroidism Increase Atrial Fibrillation Inducibility in Rats

PubMed Central

Zhang, Youhua; Dedkov, Eduard I.; Teplitsky, Diana; Weltman, Nathan Y.; Pol, Christine J.; Rajagopalan, Viswanathan; Lee, Bianca; Gerdes, A. Martin

2014-01-01

Background Evidence indicates that cardiac hypothyroidism may contribute to heart failure (HF) progression. It is also known that HF is associated with an increased risk of atrial fibrillation (AF). While it is established that hyperthyroidism increases AF incidence, the effect of hypothyroidism on AF is unclear. This study investigated the effects of different thyroid hormone levels, ranging from hypothyroidism to hyperthyroidism on AF inducibility in thyroidectomized rats. Methods and Results Thyroidectomized rats with serum confirmed hypothyroidism 1 month after surgery were randomized into hypothyroid (n=9), euthyroid (n=9) and hyperthyroid (n=9) groups. Rats received placebo, 3.3mg L-thyroxine (T4), or 20 mg T4 pellets (60 day release form) for 2 months, respectively. At the end of treatment, hypothyroid, euthyroid and hyperthyroid status was confirmed. Hypothyroid animals showed cardiac atrophy and reduced cardiac systolic and diastolic function, while hyperthyroid rats exhibited cardiac hypertrophy and increased cardiac function. Hypothyroidism and hyperthyroidism produced opposite electrophysiological changes in heart rates and atrial effective refractory period, but both significantly increased AF susceptibility. AF incidence was 78% in hypothyroid, 67% in hyperthyroid, and the duration of induced AF was also longer, compared with 11% in the euthyroid group (all p<0.05). Hypothyroidism increased atrial interstitial fibrosis, but connexin 43 was not affected. Conclusions Both hypothyroidism and hyperthyroidism lead to increased AF vulnerability in a rat thyroidectomy model. Our results stress that normal thyroid hormone levels are required to maintain normal cardiac electrophysiology and prevent cardiac arrhythmias and AF. PMID:24036190

Mood and anxiety disorders in women with treated hyperthyroidism and ophthalmopathy caused by Graves' disease.

PubMed

Bunevicius, Robertas; Velickiene, Dzilda; Prange, Arthur J

2005-01-01

To evaluate the prevalence of mood and anxiety disorders in women with treated hyperthyroidism caused by Graves' disease and to compare them with the prevalence of such findings in women without past or present thyroid disease. Thirty inpatient women with treated hyperthyroidism and ophthalmopathy caused by Graves' disease and 45 women hospitalized for treatment of gynecologic disorders such as abnormal vaginal bleeding, benign tumors or infertility were evaluated for the prevalence of mood and anxiety diagnoses using a standard Mini-International Neuropsychiatric Interview and for mood and anxiety ratings using the Profile of Mood States (POMS). At the time of assessment, it was discovered that 14 of 30 women with treated hyperthyroidism caused by Graves' disease were still hyperthyroid, while 16 women were euthyroid. Significantly greater prevalence of social anxiety disorder, generalized anxiety disorder, major depression and total mood and anxiety disorders, as well as higher symptom scores on the POMS, was found in hyperthyroid women with Graves' disease in comparison with the control group. A prevalence of total anxiety disorder, as well as history of mania or hypomania and lifetime bipolar disorder, but not lifetime unipolar depression, was more frequent in both the euthyroid and the hyperthyroid subgroups of study women in comparison with the control group. These results confirm a high prevalence of mood and anxiety disorders in women with treated hyperthyroidism and ophthalmopathy caused by Graves' disease. Hyperthyroidism plays a major role in psychiatric morbidity in Graves' disease.

Diagnosis of hyperthyroidism in cats with mild chronic kidney disease.

PubMed

Wakeling, J; Moore, K; Elliott, J; Syme, H

2008-06-01

In cats with concurrent hyperthyroidism and non-thyroidal illnesses such as chronic kidney disease, total thyroxine concentrations are often within the laboratory reference range (19 to 55 nmol/l). The objective of the study was to determine total thyroxine, free thyroxine and/or thyroid-stimulating hormone concentrations in cats with mild chronic kidney disease. Total thyroxine, free thyroxine and thyroid-stimulating hormone were measured in three groups. The hyperthyroidism-chronic kidney disease group (n=16) had chronic kidney disease and clinical signs compatible with hyperthyroidism but a plasma total thyroxine concentration within the reference range. These cats were subsequently confirmed to be hyperthyroid at a later date. The chronic kidney disease-only group (n=20) had chronic kidney disease but no signs of hyperthyroidism. The normal group (n=20) comprised clinically healthy senior (>8 years) cats. In 4 of 20 euthyroid chronic kidney disease cats, free thyroxine concentrations were borderline or high (> or =40 pmol/l). In the hyperthyroidism-chronic kidney disease group, free thyroxine was high in 15 of 16 cats, while thyroid-stimulating hormone was low in 16 of 16 cats. Most hyperthyroidism-chronic kidney disease cats (14 of 16) had total thyroxine greater than 30 nmol/l, whereas all the chronic kidney disease-only cats had total thyroxine less than 30 nmol/l. The combined measurement of free thyroxine with total thyroxine or thyroid-stimulating hormone may be of merit in the diagnosis of hyperthyroidism in cats with chronic kidney disease.

Persistent high TRAb values during pregnancy predict increased risk of neonatal hyperthyroidism following radioiodine therapy for refractory hyperthyroidism.

PubMed

Hamada, Noboru; Momotani, Naoko; Ishikawa, Naofumi; Yoshimura Noh, Jaeduk; Okamoto, Yasuyuki; Konishi, Toshiaki; Ito, Koichi; Ito, Kunihiko

2011-01-01

Serum levels of TSH receptor antibody (TRAb) often increase after radioiodine treatment for Graves' disease, and high-serum levels of maternal TRAb in late pregnancy indicate a risk of neonatal hyperthyroidism. The aim of this retrospective study is to investigate the characteristics of Graves' women who had a history of radioiodine treatment for intractable Graves' disease, and whose neonates suffered from hyperthyroidism. The subjects of this study were 45 patients with Graves' disease who became pregnant during the period from 1988 to 1998 after receiving radioiodine treatment at Ito Hospital. 25 of the 45 subjects had had a relapse of hyperthyroidism after surgical treatment for Graves' disease. 19 pregnancies were excluded because of artificial or spontaneous abortion. In the remaining 44 pregnancies of 35 patients, neonatal hyperthyroidism developed in 5 (11.3%) pregnancies of 4 patients. Serum levels of TRAb at delivery were higher in patients whose neonates suffered from hyperthyroidism (NH mother) than those of patients who delivered normal infants (N mother). Furthermore, serum levels of TRAb in NH mother did not change during pregnancy, although those of 4 patients of N mother, in which serum levels of TRAb before radioiodine treatment were as high as in NH mother, decreased significantly during pregnancy. In conclusion, women who delivered neonates with hyperthyroidism following radioiodine treatment seem to have very severe and intractable Graves' disease. Persistent high TRAb values during pregnancy observed in those patients may be a cause of neonatal hyperthyroidism.

Both hypothyroidism and hyperthyroidism increase atrial fibrillation inducibility in rats.

PubMed

Zhang, Youhua; Dedkov, Eduard I; Teplitsky, Diana; Weltman, Nathan Y; Pol, Christine J; Rajagopalan, Viswanathan; Lee, Bianca; Gerdes, A Martin

2013-10-01

Evidence indicates that cardiac hypothyroidism may contribute to heart failure progression. It is also known that heart failure is associated with an increased risk of atrial fibrillation (AF). Although it is established that hyperthyroidism increases AF incidence, the effect of hypothyroidism on AF is unclear. This study investigated the effects of different thyroid hormone levels, ranging from hypothyroidism to hyperthyroidism on AF inducibility in thyroidectomized rats. Thyroidectomized rats with serum-confirmed hypothyroidism 1 month after surgery were randomized into hypothyroid (N=9), euthyroid (N=9), and hyperthyroid (N=9) groups. Rats received placebo, 3.3-mg l-thyroxine (T4), or 20-mg T4 pellets (60-day release form) for 2 months, respectively. At the end of treatment, hypothyroid, euthyroid, and hyperthyroid status was confirmed. Hypothyroid animals showed cardiac atrophy and reduced cardiac systolic and diastolic functions, whereas hyperthyroid rats exhibited cardiac hypertrophy and increased cardiac function. Hypothyroidism and hyperthyroidism produced opposite electrophysiological changes in heart rates and atrial effective refractory period, but both significantly increased AF susceptibility. AF incidence was 78% in hypothyroid, 67% in hyperthyroid, and the duration of induced AF was also longer, compared with 11% in the euthyroid group (all P<0.05). Hypothyroidism increased atrial interstitial fibrosis, but connexin 43 was not affected. Both hypothyroidism and hyperthyroidism lead to increased AF vulnerability in a rat thyroidectomy model. Our results stress that normal thyroid hormone levels are required to maintain normal cardiac electrophysiology and to prevent cardiac arrhythmias and AF.

Forecasting the short-term passenger flow on high-speed railway with neural networks.

PubMed

Xie, Mei-Quan; Li, Xia-Miao; Zhou, Wen-Liang; Fu, Yan-Bing

2014-01-01

Short-term passenger flow forecasting is an important component of transportation systems. The forecasting result can be applied to support transportation system operation and management such as operation planning and revenue management. In this paper, a divide-and-conquer method based on neural network and origin-destination (OD) matrix estimation is developed to forecast the short-term passenger flow in high-speed railway system. There are three steps in the forecasting method. Firstly, the numbers of passengers who arrive at each station or depart from each station are obtained from historical passenger flow data, which are OD matrices in this paper. Secondly, short-term passenger flow forecasting of the numbers of passengers who arrive at each station or depart from each station based on neural network is realized. At last, the OD matrices in short-term time are obtained with an OD matrix estimation method. The experimental results indicate that the proposed divide-and-conquer method performs well in forecasting the short-term passenger flow on high-speed railway.

Thyroid Hormone Regulates the Expression of the Sonic Hedgehog Signaling Pathway in the Embryonic and Adult Mammalian Brain

PubMed Central

Desouza, Lynette A.; Sathanoori, Malini; Kapoor, Richa; Rajadhyaksha, Neha; Gonzalez, Luis E.; Kottmann, Andreas H.; Tole, Shubha

2011-01-01

Thyroid hormone is important for development and plasticity in the immature and adult mammalian brain. Several thyroid hormone-responsive genes are regulated during specific developmental time windows, with relatively few influenced across the lifespan. We provide novel evidence that thyroid hormone regulates expression of the key developmental morphogen sonic hedgehog (Shh), and its coreceptors patched (Ptc) and smoothened (Smo), in the early embryonic and adult forebrain. Maternal hypo- and hyperthyroidism bidirectionally influenced Shh mRNA in embryonic forebrain signaling centers at stages before fetal thyroid hormone synthesis. Further, Smo and Ptc expression were significantly decreased in the forebrain of embryos derived from hypothyroid dams. Adult-onset thyroid hormone perturbations also regulated expression of the Shh pathway bidirectionally, with a significant induction of Shh, Ptc, and Smo after hyperthyroidism and a decline in Smo expression in the hypothyroid brain. Short-term T3 administration resulted in a significant induction of cortical Shh mRNA expression and also enhanced reporter gene expression in Shh+/LacZ mice. Further, acute T3 treatment of cortical neuronal cultures resulted in a rapid and significant increase in Shh mRNA, suggesting direct effects. Chromatin immunoprecipitation assays performed on adult neocortex indicated enhanced histone acetylation at the Shh promoter after acute T3 administration, providing further support that Shh is a thyroid hormone-responsive gene. Our results indicate that maternal and adult-onset perturbations of euthyroid status cause robust and region-specific changes in the Shh pathway in the embryonic and adult forebrain, implicating Shh as a possible mechanistic link for specific neurodevelopmental effects of thyroid hormone. PMID:21363934

Delayed puberty caused by hyperthyroidism in ram lambs is not a result of suppression in body growth.

PubMed

Chandrasekhar, Y; D'Occhio, M J; Setchell, B P

1986-03-01

Over a period of 8 weeks ram lambs (16 weeks old) were made hyperthyroidal (serum thyroxine approximately equal to 150 ng/ml, compared with control approximately equal to 48 ng/ml) by daily subcutaneous injections of thyroxine or maintained at a constant body weight by restriction of the feed intake. Hyperthyroidal and restricted-intake lambs remained at a constant body weight during the period of treatment whilst control rams gained body weight. Testicular growth was normal in restricted-intake lambs but was suppressed in hyperthyroidal animals. Hyperthyroidism, but not feed restriction, was also associated with decrease in LH pulse frequency (1.3 +/- 0.3/12 h compared with controls 4.8 +/- 0.9/12 h. Hyperthyroidal lambs showed normal LH responses to exogenous LHRH. After cessation of treatment testicular growth continued to be suppressed for up to 16 weeks in previously hyperthyroidic rams; thereafter testes began to increase in size but at 30 weeks after treatment were still smaller than those of control rams. It is concluded that elevated thyroxine concentrations directly influence sexual maturation in ram lambs through actions at hypothalamic and/or higher brain centres which control LH secretion. Transient hyperthyroidism during sexual maturation may cause permanent impairment of sexual development.

Antenatal management of recurrent fetal goitrous hyperthyroidism associated with fetal cardiac failure in a pregnant woman with persistent high levels of thyroid-stimulating hormone receptor antibody after ablative therapy.

PubMed

Matsumoto, Tadashi; Miyakoshi, Kei; Saisho, Yoshifumi; Ishii, Tomohiro; Ikenoue, Satoru; Kasuga, Yoshifumi; Kadohira, Ikuko; Sato, Seiji; Momotani, Naoko; Minegishi, Kazuhiro; Yoshimura, Yasunori

2013-01-01

High titer of maternal thyroid-stimulating hormone receptor antibody (TRAb) in patients with Graves' disease could cause fetal hyperthyroidism during pregnancy. Clinical features of fetal hyperthyroidism include tachycardia, goiter, growth restriction, advanced bone maturation, cardiomegaly, and fetal death. The recognition and treatment of fetal hyperthyroidism are believed to be important to optimize growth and intellectual development in affected fetuses. We herein report a case of fetal treatment in two successive siblings showing in utero hyperthyroid status in a woman with a history of ablative treatment for Graves' disease. The fetuses were considered in hyperthyroid status based on high levels of maternal TRAb, a goiter, and persistent tachycardia. In particular, cardiac failure was observed in the second fetus. With intrauterine treatment using potassium iodine and propylthiouracil, fetal cardiac function improved. A high level of TRAb was detected in the both neonates. To the best of our knowledge, this is the first report on the changes of fetal cardiac function in response to fetal treatment in two siblings showing in utero hyperthyroid status. This case report illustrates the impact of prenatal medication via the maternal circulation for fetal hyperthyroidism and cardiac failure.

Hyperthyroidism and human chorionic gonadotrophin production in gestational trophoblastic disease

PubMed Central

Walkington, L; Webster, J; Hancock, B W; Everard, J; Coleman, R E

2011-01-01

Background: Gestational trophoblastic disease (GTD) is a rare complication of pregnancy, ranging from molar pregnancy to choriocarcinoma. Patients with persistent disease require treatment with chemotherapy. For the vast majority, prognosis is excellent. Occasionally, GTD is complicated by hyperthyroidism, which may require treatment. This is thought to occur due to molecular mimicry between human chorionic gonadotrophin (HCG) and thyroid-stimulating hormone (TSH), and hence cross-reactivity with the TSH receptor. Hyperthyroidism usually resolves as the GTD is successfully treated and correspondingly HCG levels normalise. Methods: This paper reviews cases of GTD treated over a 5-year period at one of the three UK centres and identifies the prevalence of hyperthyroidism in this population. Four cases with clinical hyperthyroidism are discussed. Results: On review of the 196 patients with gestational trophoblastic neoplasia treated with chemotherapy in Sheffield since 2005, 14 (7%) had biochemical hyperthyroidism. Of these, four had evidence of clinical hyperthyroidism. Conclusion: Concomitant biochemical thyroid disease in patients with GTD is relatively common, and measurement of thyroid function in patients with persistent GTD is, therefore, important. The development of hyperthyroidism is largely influenced by the level of HCG and disease burden, and usually settles with treatment of the persistent GTD. However, rarely the thyroid stimulation can have potentially life-threatening consequences. PMID:21522146

Severe fetal and neonatal hyperthyroidism years after surgical treatment of maternal Graves' disease.

PubMed

Dierickx, I; Decallonne, B; Billen, J; Vanhole, C; Lewi, L; De Catte, L; Verhaeghe, J

2014-02-01

Fetal/neonatal hyperthyroidism is a well-known complication of maternal Graves' disease with high concentrations of TSH-receptor antibodies (TRAb). Few data are available on the management of fetal hyperthyroidism in surgically treated Graves' disease. Clinical, ultrasound and biochemical data are reported in a fetus/neonate whose mother underwent a thyroidectomy > 10 years before and whose sibling was thin and hyperthyroid at birth. Maternal TRAb were persistently > 40 U/l; unequivocal signs of fetal hyperthyroidism were identified at 29 weeks gestational age (GA). The fetus was treated through maternal antithyroid drug (ATD) administration; the dose was reduced gradually once fetal tachycardia and valve dysfunction disappeared and normal T4 was confirmed by fetal blood sampling. Maternal euthyroidism was maintained. The neonate showed normal growth for GA and T4 concentration at birth but severe hyperthyroidism relapsed from day 13 until day 58. TSH remained strongly suppressed throughout the pre- and postnatal course. Prenatal ATD in a taper-off regime allowed normal T4 and growth in a hyperthyroid fetus from a thyroidectomised Graves' mother. Fetal TSH cannot be used to adjust the ATD dose. Prenatal ATD appears to postpone the onset but does not affect the severity or duration of the neonatal hyperthyroid flare.

Subclinical hyperthyroidism due to a thyrotropin receptor (TSHR) gene mutation (S505R).

PubMed

Pohlenz, Joachim; Pfarr, Nicole; Krüger, Silvia; Hesse, Volker

2006-12-01

To identify the molecular defect by which non-autoimmune subclinical hyperthyroidism was caused in a 6-mo-old infant who presented with weight loss. Congenital non-autoimmune hyperthyroidism is caused by activating germline mutations in the thyrotropin receptor (TSHR) gene. Therefore, the TSHR gene was sequenced directly from the patient's genomic DNA. Molecular analysis revealed a heterozygous point mutation (S505R) in the TSHR gene as the underlying defect. A constitutively activating mutation in the TSHR gene has to be considered not only in patients with severe congenital non-autoimmune hyperthyroidism, but also in children with subclinical non-autoimmune hyperthyroidism.

[Prevention and multimodal therapy of hyperthyroidism].

PubMed

Palitzsch, K-D

2008-12-01

Subclinical and overt hyperthyroidism have been associated with various negative clinical outcomes as for example an increased risk of atrial fibrillation or increased cardiovascular mortality, especially in old age. In order to avoid hyperthyroidism it is strongly recommended not to start any iodine containing drug therapy or to avoid application of contrast agents unless the patient presents with an unremarkable clinical course. TSH suppressive therapy for the treatment of endemic goiter or differentiated low risk thyroid carcinoma is unnecessary, since it favours the development of subclinical hyperthyroidism. Overt hyperthyroidism is treated with antithyroid drugs and/or radioiodine therapy or surgery according to the underlying disease (toxic nodular goiter, Graves' disease).

Consequences of hyperthyroidism in male and female fertility: pathophysiology and current management.

PubMed

Mintziori, G; Kita, M; Duntas, L; Goulis, D G

2016-08-01

Thyroid hormone acts on the oocytes, sperm and embryo during fertilization, implantation and placentation. Both hypothyroidism and hyperthyroidism may influence fertility. However, evidence of the association of hyperthyroidism with infertility is scarce and sometimes conflicting. Thyroid hormone influences human reproduction via a variety of mechanisms at both the central and the peripheral level. Infertility may occur in hyperthyroid men and women, but it is usually reversible upon restoration of euthyroidism. This review aims to summarize the available data on the association of hyperthyroidism and infertility in both men and women and to provide practical suggestions for the management of these patients.

Various Manifestations of Hyperthyroidism in an Ambulatory Clinic: Case Studies

PubMed Central

Tripp, Warren; Rao, Vijaya; Creary, Ludlow B.

1987-01-01

This study reviews five cases of women with hyperthyroidism, three black women and two Hispanic women. Initially, two patients presented with voice changes, weight loss, and increased appetite. Only two patients presented with classical symptoms of hyperthyroidism. Examination showed all patients had diffusely enlarged thyroids and exaggerated reflexes. Two patients showed Graves' opthalmopathy. These cases document the variety of presentations of hyperthyroidism. Hence, a high index of suspicion must exist for this disease, even in the absence of a number of the classical manifestations of hyperthyroidism. When patients present to primary care centers with a constellation of symptoms, an examination of the thyroid gland is essential. PMID:3694696

The Clinical and Thyroid Function Studies of Lymphocytic Thyroiditis with Spontaneously Resolving Hyperthyroidism: Comparison to Subacute Thyroiditis

PubMed Central

Koh, Eun Hee; Park, Yong Joon; Lee, Hyun Chul; Hong, Chein Soo; Huh, Kap Bum; Lee, Sang Yong; Ryu, Kyung Za

1986-01-01

Lymphocytic thyroiditis with spontaneously resolving hyperthyroidism (LT-SRH) has been reported in the past years, and is referred to as “silent thyroiditis.” It is characterized by a low or decreased radioactive iodine uptake (RAIU) of thyroid in a patient with hyperthyroidism in whom initial diagnosis is generally thought to be Graves’ disease. Thirty-five patients who had hyperthyroidism or goiter with decreased RAIU have been assessed. Twenty-four (68.6%) of 35 patients had LT-SRH and the remaining patients, subacute thyroiditis (SAT). The clinical characteristics of the patients with LT-SRH were a history of delivery, painless goiter, elevated T3 and T4 levels and positive anti-microsomal antibodies. Anti-microsomal antibodies were positive in 70.8% of the LT-SRH group, whereas 12.5% in the SAT group. Resolution of the hyperthyroidism took 8 to 12 months. It is considered that LT-SRH is an autoimmune thyroiditis with spontaneously resolving hyperthyroidism and determination of the RAIU is very useful in differentiating from other forms of hyperthyroidism. PMID:15759376

Role of the renin-angiotensin system in cardiac hypertrophy induced in rats by hyperthyroidism

PubMed Central

KOBORI, HIROYUKI; ICHIHARA, ATSUHIRO; SUZUKI, HIROMICHI; TAKENAKA, TSUNEO; MIYASHITA, YUTAKA; HAYASHI, MATSUHIKO; SARUTA, TAKAO

2008-01-01

This study was conducted to examine whether the renin-angiotensin system contributes to hyperthyroidism-induced cardiac hypertrophy without involving the sympathetic nervous system. Sprague-Dawley rats were divided into control-innervated, control-denervated, hyperthyroid-innervated, and hyperthyroid-denervated groups using intraperitoneal injections of thyroxine and 6-hydroxydopamine. After 8 wk, the heart-to-body weight ratio increased in hyperthyroid groups (63%), and this increase was only partially inhibited by sympathetic denervation. Radioimmunoassays and reverse transcription-polymerase chain reaction revealed increased cardiac levels of renin (33%) and angiotensin II (53%) and enhanced cardiac expression of renin mRNA (225%) in the hyperthyroid groups. These increases were unaffected by sympathetic denervation or 24-h bilateral nephrectomy. In addition, losartan and nicardipine decreased systolic blood pressure to the same extent, but only losartan caused regression of thyroxine-induced cardiac hypertrophy. These results suggest that thyroid hormone activates the cardiac renin-angiotensin system without involving the sympathetic nervous system or the circulating renin-angiotensin system; the activated renin-angiotensin system contributes to cardiac hypertrophy in hyperthyroidism. PMID:9277473

Percutaneous transvenous mitral commissurotomy in patients with mitral stenosis and coexistent hyperthyroidism.

PubMed

Wang, P W; Hung, J S; Fu, M; Yeh, K H; Wu, J J

1996-01-01

Percutaneous transvenous mitral commissurotomy (PTMC) was performed successfully without complications in 3 patients with severe mitral stenosis and hyperthyroidism. All 3 patients had pliable, noncalcified mitral valves. One patient who had been treated with methimazole for 6 months was still in a hyperthyroid state when she presented with intractable congestive heart failure and was found to have severe mitral stenosis. The heart failure improved immediately after PTMC, but the patient remained in New York Heart Association functional class 2 until a euthyroid state was achieved with I131 therapy. In the other 2 patients, hyperthyroidism was unsuspected at the time of PTMC. Unexpectedly suboptimal symptom improvement led to the diagnosis of hyperthyroidism 1 month after the intervention. In all 3 patients, PTMC resulted in an immediate hemodynamic and clinical improvement. However, complete clinical improvement occurred only when euthyroid state was achieved after antithyroid treatment. The present study suggests that PTMC is a safe and effective intervention modality in patients with coexisting hyperthyroidism and severe mitral stenosis. The procedure may be considered a therapeutic option in patients with hyperthyroidism and severe mitral stenosis.

[Activity of antioxidative enzymes and concentration of malondialdehyde as oxidative status markers in women with non-autoimmunological subclinical hyperthyroidism].

PubMed

Rybus-Kalinowska, Barbara; Zwirska-Korczala, Krystyna; Kalinowski, Mariusz; Kukla, Michał; Birkner, Ewa; Jochem, Jerzy

2009-01-01

The recent investigations point out the significant role of oxidative stress in the development of thyroid gland disease. The present study was designed to investigate the variation of oxidative stae in women with non-autoimmunological subclinical hyperthyroidism. The study was conducted on 20 females with non-autoimmunological subclinical hyperthyroidism and 15 healthy women. Manganase-containing superoxide dismutase (Mn-SOD) and extracellular superoxide dismutase (EC-SOD) plasma activity, and malondialdehyde (MDA) plasma concentration were measured. EC-SOD plasma activity was significantly higher in women with subclinical hyperthyroidism when compared with the control group (13.3 +/- 2.1 vs. 10.9 +/- 1.4 NU/ml; p < 0.05), unlike Mn-SOD (4.2 +/- 0.5 vs. 4.0 +/- 1.0 NU/ml). MDA plasma concentration increased significantly in women with subclinical hyperthyroidism (3.5 +/- 1.2 vs. 2.0 +/- 0.6 micromol/l; p < 0.05). The increased EC-SOD plasma activity may reflect disturbances of oxidative state in subclinical hyperthyroidism. Parallel increase of MDA plasma concentration may indicate enhancement of lipid peroxidationin in patients with subclinical hyperthyroidism.

Role of the renin-angiotensin system in cardiac hypertrophy induced in rats by hyperthyroidism.

PubMed

Kobori, H; Ichihara, A; Suzuki, H; Takenaka, T; Miyashita, Y; Hayashi, M; Saruta, T

1997-08-01

This study was conducted to examine whether the renin-angiotensin system contributes to hyperthyroidism-induced cardiac hypertrophy without involving the sympathetic nervous system. Sprague-Dawley rats were divided into control-innervated, control-denervated, hyperthyroid-innervated, and hyperthyroid-denervated groups using intraperitoneal injections of thyroxine and 6-hydroxydopamine. After 8 wk, the heart-to-body weight ratio increased in hyperthyroid groups (63%), and this increase was only partially inhibited by sympathetic denervation. Radioimmunoassays and reverse transcription-polymerase chain reaction revealed increased cardiac levels of renin (33%) and angiotensin II (53%) and enhanced cardiac expression of renin mRNA (225%) in the hyperthyroid groups. These increases were unaffected by sympathetic denervation or 24-h bilateral nephrectomy. In addition, losartan and nicardipine decreased systolic blood pressure to the same extent, but only losartan caused regression of thyroxine-induced cardiac hypertrophy. These results suggest that thyroid hormone activates the cardiac renin-angiotensin system without involving the sympathetic nervous system or the circulating renin-angiotensin system; the activated renin-angiotensin system contributes to cardiac hypertrophy in hyperthyroidism.

Plasmatic endothelin-1 levels in hyperthyroid patients before and after antithyroid therapy.

PubMed

Cesareo, R; Tarabuso, A; Di Benedetto, M; Lacerna, F; Reda, G

2000-03-01

The Endothelin-1 (ET-1) is a powerful vasoconstrictor peptide produced by endothelial cells in many vascular diseases probably as a response to vessel damage. In hyperthyroidism as in other endocrinological diseases elevated ET-1 plasma levels have been found. The effect of antithyroid therapy on ET-1 plasmatic levels was evaluated by measuring ET-1 plasma levels before and 2 and 6 months after treatment with methimazole in 14 patients affected by hyperthyroidism. The hyperthyroid patients had significantly higher ET-1 levels than the controls (18.85 +/- 5.7 vs 10.9 +/- 2.1 pg/ml), while after treatment no difference was found. The ET-1 plasma levels of hyperthyroid patients correlated closely with the raised thyroid metabolic activity independently of its cause. It is possible that the increased ET-1 levels in hyperthyroid patients are the expression of blood vessel damage caused by high thyroid hormone levels. Moreover the results of this study could suggest that, in future, ET-1 plasmatic levels might be considered as a functional thyroid index in hyperthyroid diseases.

Incident thyroid disease in female spouses of private pesticide applicators.

PubMed

Shrestha, Srishti; Parks, Christine G; Goldner, Whitney S; Kamel, Freya; Umbach, David M; Ward, Mary H; Lerro, Catherine C; Koutros, Stella; Hofmann, Jonathan N; Beane Freeman, Laura E; Sandler, Dale P

2018-06-13

Little is known about modifiable risk factors for thyroid disease. Several pesticides have been implicated in thyroid disruption, but clinical implications are not clear. We assessed associations between pesticide use and other farm exposures and incident hypothyroidism and hyperthyroidism in female spouses of farmers in the Agricultural Health Study (AHS). We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals for risk of thyroid disease in 24,092 spouses who completed at least one follow-up questionnaire. We identified 1627 hypothyroid and 531 hyperthyroid cases over 20 years of follow-up. The fungicides benomyl, maneb/mancozeb, and metalaxyl, the herbicide pendimethalin, and among those over 60 years of age the insecticides parathion and permethrin (applied to crops) were associated with elevated hypothyroidism risk, with HR ranging from 1.56-2.44. Conversely, the insecticide phorate, and the herbicides imazethapyr and metolachlor were associated with decreased risk (HR ranging 0.63-0.73), as were long-term farm residence and other farm-related activities (HR ranging 0.69-0.84). For hyperthyroidism, the insecticide diazinon, the fungicides maneb/mancozeb, and the herbicide metolachlor were associated with increased risk (HR ranging 1.35-2.01) and the herbicide trifluralin with decreased risk (HR: 0.57). Several individual pesticides were associated with increased risk of hypothyroidism and hyperthyroidism, although some pesticides were associated with decreased risk. Some of the findings, specifically associations with fungicides, are consistent with results from an earlier analysis of prevalent diseases in AHS spouses. Published by Elsevier Ltd.

The role of short-term memory impairment in nonword repetition, real word repetition, and nonword decoding: A case study.

PubMed

Peter, Beate

2018-01-01

In a companion study, adults with dyslexia and adults with a probable history of childhood apraxia of speech showed evidence of difficulty with processing sequential information during nonword repetition, multisyllabic real word repetition and nonword decoding. Results suggested that some errors arose in visual encoding during nonword reading, all levels of processing but especially short-term memory storage/retrieval during nonword repetition, and motor planning and programming during complex real word repetition. To further investigate the role of short-term memory, a participant with short-term memory impairment (MI) was recruited. MI was confirmed with poor performance during a sentence repetition and three nonword repetition tasks, all of which have a high short-term memory load, whereas typical performance was observed during tests of reading, spelling, and static verbal knowledge, all with low short-term memory loads. Experimental results show error-free performance during multisyllabic real word repetition but high counts of sequence errors, especially migrations and assimilations, during nonword repetition, supporting short-term memory as a locus of sequential processing deficit during nonword repetition. Results are also consistent with the hypothesis that during complex real word repetition, short-term memory is bypassed as the word is recognized and retrieved from long-term memory prior to producing the word.

Accelerated characterization of graphite/epoxy composites

NASA Technical Reports Server (NTRS)

Griffith, W. I.; Morris, D. H.; Brinson, H. F.

1980-01-01

A method to predict the long term compliance of unidirectional off-axis laminates from short term laboratory tests is presented. The method uses an orthotropic transformation equation and the time-stress-temperature superposition principle. Short term tests are used to construct master curves for two off-axis unidirectional laminates with fiber angles of 10 and 90 degrees. Analytical predictions of long term compliance for 30 and 60 degrees laminates are made. Comparisons with experimental data are also given.

[Insulin, glucagon and growth hormone responses during glucose, arginine and insulin tolerance tests in children with hyperthyroidism].

PubMed

Kato, T; Matsuura, N; Fujita, H; Fujieda, K; Nohara, Y; Mikami, Y; Abe, K; Fukushima, N

1985-06-20

There are many reports of glucose intolerance in adult patients with hyperthyroidism but few reports of glucose intolerance in hyperthyroid children. In this study, we measured plasma levels of glucose, insulin, glucagon and growth hormone in hyperthyroid children and control subjects by the use of three kinds of tolerance tests: an oral glucose tolerance test, an arginine tolerance test and an insulin tolerance test. In the oral glucose tolerance test, mean fasting glucose levels (79.6 +/- 1.4 mg/dl) rose to maximum levels (157.3 +/- 4.3 mg/dl) at 30 min in hyperthyroid children which were significantly higher than the levels in control subjects (p less than 0.01). The maximum levels of glucose fell slowly and returned to fasting levels at 180 min. In this test, plasma insulin levels increased from basal levels (12.7 +/- 1.9 microU/ml) to maximum levels (120.8 +/- 22.1 microU/ml) at 30 min in the prepubertal age group of hyperthyroidism. On the other hand, in the pubertal age group of hyperthyroidism, maximum levels of insulin were observed at 60 min, but not at 30 min. These maximum levels of insulin of both hyperthyroid age groups were significantly higher than those in the control subjects (p less than 0.05, p less than 0.01 respectively). There was no difference in insulin-glucose ratio at 30 min (delta IRI/delta BG) and insulinogenic index (I.I.) at 0 to 60 min between these two groups of hyperthyroid children and control subjects. However, I.I. at 0 to 120 min and 0 to 180 min decreased significantly in the pubertal age group of hyperthyroidism as compared with those in the control group (p less than 0.05, p less than 0.02 respectively). In the oral glucose tolerance test, plasma glucagon levels decreased from basal levels (74.1 +/- 4.3 pg/ml) to minimum levels (36.4 +/- 4.7 pg/ml) at 90 min in hyperthyroidism, which were significantly lower than those in the controls (p less than 0.05). However, there was no difference in -epsilon delta IRG/epsilon delta BG (cumulative glucagon response/cumulative glucose response) between the subjects with hyperthyroidism and the controls. On the other hand, lower responses of blood glucose, insulin, glucagon and growth hormone to arginine were observed in subjects with hyperthyroidism than in the controls. Moreover in the insulin tolerance test, there was no difference in glucagon and growth hormone response between the subjects with hyperthyroidism and the controls. Thus our conclusions are as follows: A marked increase in blood glucose after oral glucose load was observed in spite of normal insulin-glucose ratio in hyperthyroid children, suggesting the existence of peripheral insulin resistance.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of feline hyperthyroidism on kidney function: a review.

PubMed

Vaske, Heather H; Schermerhorn, Thomas; Grauer, Gregory F

2016-02-01

Chronic kidney disease and hyperthyroidism are two commonly diagnosed conditions in the geriatric feline population, and are often seen concurrently. Management of both diseases is recommended; however, the physiologic implications of both diseases must be understood to ensure the most favorable outcome for each patient. This report reviews the complex interplay between hyperthyroidism and kidney function, as well as the effects of hyperthyroid therapy on kidney function. © ISFM and AAFP 2015.

Changing axis deviation and paroxysmal atrial flutter associated with subclinical hyperthyroidism.

PubMed

Patanè, Salvatore; Marte, Filippo

2010-10-08

Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with coronary heart disease or mortality from cardiovascular causes but it is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. It has also been reported that increased factor X activity in patients with subclinical hyperthyroidism represents a potential hypercoagulable state. Rarely, it has also been reported intermittent changing axis deviation during atrial fibrillation and during atrial flutter. We present a case of paroxysmal atrial flutter and changing axis deviation associated with subclinical hyperthyroidism, in a 76-year-old Italian man. Also this case focuses attention on the importance of a correct evaluation of subclinical hyperthyroidism. Copyright © 2008 Elsevier Ireland Ltd. All rights reserved.

Hyperthyroidism and cardiovascular complications: a narrative review on the basis of pathophysiology

PubMed Central

Cicero, Arrigo F.

2013-01-01

Cardiovascular complications are important in hyperthyroidism because of their high frequency in clinical presentation and increased mortality and morbidity risk. The cause of hyperthyroidism, factors related to the patient, and the genetic basis for complications are associated with risk and the basic underlying mechanisms are important for treatment and management of the disease. Besides cellular effects, hyperthyroidism also causes hemodynamic changes, such as increased preload and contractility and decreased systemic vascular resistance causes increased cardiac output. Besides tachyarrythmias, impaired systolic ventricular dysfunction and diastolic dysfunction may cause thyrotoxic cardiomyopathy in a small percentage of the patients, as another high mortality complication. Although the medical literature has some conflicting data about benefits of treatment of subclinical hyperthyroidism, even high-normal thyroid function may cause cardiovascular problems and it should be treated. This review summarizes the cardiovascular consequences of hyperthyroidism with underlying mechanisms. PMID:24273583

Serum apelin levels in patients with thyroid dysfunction

PubMed Central

Gürel, Ali; Doğantekin, Akif; Özkan, Yusuf; Aydın, Süleyman

2015-01-01

Adipocytes are not only for energy storage, but are also functionally active cells, producing biologically active peptides called adipocytokines. Adipocytokines control nutrition, thermogenesis, immunity, thyroid and reproductive hormones, and neuroendocrine functions. One of the most important new members of this family is apelin. In patients with thyroid dysfunctions, there are usually changes in weight, thermogenesis and adipose tissue lipolysis. Here, we investigated the serum apelin levels in different thyroid hormone states. Our study group consisted of the following patients: 32 thyrotoxicosis, 32 subclinical hyperthyroidism, 31 hypothyroidism, 34 subclinical hypothyroidism and 31 healthy control cases. In addition to routine blood tests, serum free T3 (FT3), free T4 (FT4), TSH and apelin levels were measured, and the body mass index (BMI) was recorded. In terms of the demographic characteristics, age and BMI, there was no statistically significant difference between the groups (P>0.05). The mean serum apelin levels of the groups were as follows: thyrotoxicosis group, 4.6±1.9 ng/ml; subclinical hyperthyroidism group, 3.7±1.9 ng/ml; hypothyroid group, 4.8±2.5 ng/ml; subclinical hypothyroidism group, 4.3±2.2 ng/mL; and control group, 3.4±1.4 ng/ml, respectively. There was no statistically significant difference in terms of the mean apelin levels between the groups (P>0.05). The hypothyroid group had the highest and the control group had the lowest mean apelin levels. As a result, the apelin levels were higher in both the patients with hypothyroidism and hyperthyroidism, in comparison with the normal population, but without statistical significance. PMID:26629164

Transient hyperthyroidism of hyperemesis gravidarum.

PubMed

Tan, Jackie Y L; Loh, Keh Chuan; Yeo, George S H; Chee, Yam Cheng

2002-06-01

To characterise the clinical, biochemical and thyroid antibody profile in women with transient hyperthyroidism of hyperemesis gravidarum. Prospective observational study. Hospital inpatient gynaecological ward. Women admitted with hyperemesis gravidarum and found to have hyperthyroidism. Fifty-three women were admitted with hyperemesis gravidarum and were found to have hyperthyroidism. Each woman was examined for clinical signs of thyroid disease and underwent investigations including urea, creatinine, electrolytes, liver function test, thyroid antibody profile and serial thyroid function test until normalisation. Gestation at which thyroid function normalised, clinical and thyroid antibody profile and pregnancy outcome (birthweight, gestation at delivery and Apgar score at 5 minutes). Full data were available for 44 women. Free T4 levels normalised by 15 weeks of gestation in the 39 women with transient hyperthyroidism while TSH remained suppressed until 19 weeks of gestation. None of these women were clinically hyperthyroid. Thyroid antibodies were not found in most of them. Median birthweight in the infants of mothers who experienced weight loss of > 5% of their pre-pregnancy weight was lower compared with those of women who did not (P = 0.093). Five women were diagnosed with Graves' disease based on clinical features and thyroid antibody profile. In transient hyperthyroidism of hyperemesis gravidarum, thyroid function normalises by the middle of the second trimester without anti-thyroid treatment. Clinically overt hyperthyroidism and thyroid antibodies are usually absent. Apart from a non-significant trend towards lower birthweights in the infants of mothers who experienced significant weight loss, pregnancy outcome was generally good. Routine assessment of thyroid function is unnecessary for women with hyperemesis gravidarum in the absence of any clinical features of hyperthyroidism.

Effects of hyperthyroidism on expression of vascular endothelial growth factor (VEGF) and apoptosis in fetal adrenal glands.

PubMed

Karaca, T; Hulya Uz, Y; Karabacak, R; Karaboga, I; Demirtas, S; Cagatay Cicek, A

2015-11-26

This study investigated the expression of vascular endothelial growth factor (VEGF), vascular density, and apoptosis in fetal rat adrenal glands with hyperthyroidism in late gestation. Twelve mature female Wistar albino rats with the same biological and physiological features were used for this study. Rats were divided into two groups: control and hyperthyroidism. Hyperthyroidism was induced by daily subcutaneous injections of L-thyroxine (250 μg/kg) before pregnancy for 21 days and during pregnancy. Rats in the control and hyperthyroidism groups were caged according to the number of male rats. Zero day of pregnancy (Day 0) was indicated when the animals were observed to have microscopic sperm in vaginal smears. Pregnant rats were sacrificed on the 20th day of pregnancy; blood from each animal was collected to determine the concentrations of maternal adrenocorticotropic hormone and thyroxine. Rat fetuses were then quickly removed from the uterus, and the adrenal glands of the fetuses were dissected. VEGF expression, vascular density, and apoptosis were analyzed in fetal rat adrenal glands. Maternal serum levels of the adrenocorticotropic hormone and free thyroxine were significantly higher in the hyperthyroidism group than in the control group. Immunohistochemistry revealed that the number of VEGF positive cells and vessel density significantly increased in the hyperthyroidism rat fetal adrenal group compared with the control group. Hyperthyroidism did not change the fetal and placental weights and the number of fetuses. This study demonstrates that hyperthyroidism may have an effect on the development of rat adrenal glands mediated by VEGF expression, angiogenesis, and apoptosis.

Effects of Hyperthyroidism on Expression of Vascular Endothelial Growth Factor (VEGF) and Apoptosis in Fetal Adrenal Glands

PubMed Central

Hulya Uz, Y.; Karabacak, R.; Karaboga, I.; Demirtas, S.; Cagatay Cicek, A.

2015-01-01

This study investigated the expression of vascular endothelial growth factor (VEGF), vascular density, and apoptosis in fetal rat adrenal glands with hyperthyroidism in late gestation. Twelve mature female Wistar albino rats with the same biological and physiological features were used for this study. Rats were divided into two groups: control and hyperthyroidism. Hyperthyroidism was induced by daily subcutaneous injections of L-thyroxine (250 µg/kg) before pregnancy for 21 days and during pregnancy. Rats in the control and hyperthyroidism groups were caged according to the number of male rats. Zero day of pregnancy (Day 0) was indicated when the animals were observed to have microscopic sperm in vaginal smears. Pregnant rats were sacrificed on the 20th day of pregnancy; blood from each animal was collected to determine the concentrations of maternal adrenocorticotropic hormone and thyroxine. Rat fetuses were then quickly removed from the uterus, and the adrenal glands of the fetuses were dissected. VEGF expression, vascular density, and apoptosis were analyzed in fetal rat adrenal glands. Maternal serum levels of the ACTH and free thyroxine were significantly higher in the hyperthyroidism group than in the control group. Immunohistochemistry revealed that the number of VEGF positive cells and vessel density significantly increased in the hyperthyroidism rat fetal adrenal group compared with the control group. Hyperthyroidism did not change the fetal and placental weights and the number of fetuses. This study demonstrates that hyperthyroidism may have an effect on the development of rat adrenal glands mediated by VEGF expression, angiogenesis, and apoptosis. PMID:26708182

Hyperthyroidism impairs pancreatic beta cell adaptations to late pregnancy and maternal liporegulation in the rat.

PubMed

Holness, M J; Greenwood, G K; Smith, N D; Sugden, M C

2005-11-01

Hyperthyroidism modifies lipid dynamics (increased oxidation), impairs insulin action and can suppress insulin secretion. We therefore examined the impact of hyperthyroidism on the relationship between glucose-stimulated insulin secretion (GSIS) and insulin action, using late pregnancy as a model of physiological insulin resistance that is associated with compensatory insulin hypersecretion to maintain glucose tolerance. Our aim was to examine whether hyperthyroidism compromises the regulation of insulin secretion and the ability of insulin to modulate circulating lipid concentrations in late pregnancy. Hyperthyroidism was induced by tri-iodothyronine (T(3)) administration from day 17 to 19 of pregnancy. GSIS was assessed during an IVGTT and during hyperglycaemic clamps in vivo and in vitro, using step-up and -down islet perifusions. Hyperthyroidism in pregnancy elevated the glucose threshold for GSIS and impaired GSIS at low and high glucose concentrations in islet perifusions. In the intact animal, insulin secretion (after bolus glucose) was more rapidly curtailed following removal of the glucose stimulus to secretion. In contrast, GSIS was maintained during protracted hyperglycaemia (hyperglycaemic clamps) in the hyperthyroid pregnant state in vivo. Hyperthyroidism in vivo during late pregnancy blunts GSIS in subsequently isolated and perifused islets at low and high glucose concentrations. It also adversely affects GSIS under conditions of an acute glucose challenge in vivo. In contrast, GSIS is maintained during sustained hyperglycaemia in vivo, suggesting that in vivo factors can rescue GSIS. The ability of insulin to suppress systemic lipid levels during hyperglycaemic clamps was impaired. We therefore suggest that higher circulating lipids may preserve GSIS under conditions of sustained hyperglycaemia in the hyperthyroid pregnancy.

Bladder Pain Syndrome/Interstitial Cystitis Is Associated with Hyperthyroidism

PubMed Central

Liu, Shih-Ping; Lin, Ching-Chun; Lin, Herng-Ching

2013-01-01

Background Although the etiology of bladder pain syndrome/interstitial cystitis (BPS/IC) is still unclear, a common theme with BPS/IC patients is comorbid disorders which are related to the autonomic nervous system that connects the nervous system to end-organs. Nevertheless, no study to date has reported the association between hyperthyroidism and BPS/IC. In this study, we examined the association of IC/BPS with having previously been diagnosed with hyperthyroidism in Taiwan. Design Data in this study were retrieved from the Longitudinal Health Insurance Database. Our study consisted of 736 female cases with BPS/IC and 2208 randomly selected female controls. We performed a conditional logistic regression to calculate the odds ratio (OR) for having previously been diagnosed with hyperthyroidism between cases and controls. Results Of the 2944 sampled subjects, there was a significant difference in the prevalence of prior hyperthyroidism between cases and controls (3.3% vs. 1.5%, p<0.001). The conditional logistic regression analysis revealed that compared to controls, the OR for prior hyperthyroidism among cases was 2.16 (95% confidence interval (CI): 1.27∼3.66). Furthermore, the OR for prior hyperthyroidism among cases was 2.01 (95% CI: 1.15∼3.53) compared to controls after adjusting for diabetes, coronary heart disease, obesity, hyperlipidemia, chronic pelvic pain, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, depression, panic disorder, migraines, sicca syndrome, allergies, endometriosis, and asthma. Conclusions Our study results indicated an association between hyperthyroidism and BPS/IC. We suggest that clinicians treating female subjects with hyperthyroidism be alert to urinary complaints in this population. PMID:23991081

Evaluation of oxidative status with exhaled breath 8-isoprostane levels in patients with hyperthyroidism.

PubMed

Bastug, Emrah; Tasliyurt, Turker; Kutluturk, Faruk; Sahin, Safak; Yilmaz, Ayse; Sivgin, Hakan; Yelken, Berna Murat; Ozturk, Banu; Yilmaz, Abdulkerim; Sahin, Semsettin

2013-12-01

Studies conducted so far on the effect of hyperthyroidism on oxidative stress (OS) have employed blood and urine samples. Exhaled Breath Condensate (EBC) is a non-invasive technique used to take sample from lungs to determine many biological indications. The aim of the present study was determine the possibility of using 8- isoprostane levels in EBC as an indicator of OS in hyperthyroid patients. The present study was performed on 42 patients with hyperthyroidism and 42 healthy control subjects. Hyperthyroid patients included patients with newly diagnosed Graves' disease, toxic multinodular goiter and toxic adenoma. Exhaled breath condensates were collected from patients in each group using a condensing device. 8- isoprostane levels as an indicator of OS in EBC were detected via immunoassay method. Hyperthyroid patients and control groups had 8-isoprostane levels of 6.08±6.31 and 1.56±0.88 pg/ml, respectively. The difference between patient and control groups was statistically significant (p<0.001). Of the hyperthyroid patients, eleven had Graves', 21 multinodular goiter, and 10 toxic adenoma diagnosis. There were no significant differences among patients of different diagnoses for 8-isoprostane levels (p=0.541). No significant correlations were found between 8-isoprostane and free thyroxine (fT4) or thyroid stimulating hormone (TSH) levels. In the present study, 8-isoprostane levels in EBC of hyperthyroid patients were found to be significantly higher than that in healthy control group. This study is important in that it is the first to evaluate the effects on respiratory system of elevated OS of hyperthyroidism in EBC.

Hyperthyroidism and thyroid cancer risk: a population-based cohort study.

PubMed

Yeh, N-C; Chou, C-W; Weng, S-F; Yang, C-Y; Yen, F-C; Lee, S-Y; Wang, J-J; Tien, K-J

2013-07-01

Thyroid hormones regulate the rate of metabolism and affect the differentiation and growth of many tissues in the body. We investigated the association between hyperthyroidism and cancer risk in Taiwan. A random sample of 1 000 000 individuals from Taiwan's National Health Insurance database was enrolled. We found 17 033 patients to have newly diagnosed hyperthyroidism between 2000 and 2005. These patients were recruited along with a match cohort of 34 066 patients without hyperthyroidism. Starting from index date, we followed up all patients for 4 years to identify those who developed cancer. During the 4-year follow-up study, cancer was diagnosed in 1.23% of patients with hyperthyroidism and 1.02% of the member of the comparison cohort. Regression analysis showed that patients with hyperthyroidism were at greater risk of cancer incidence, especially thyroid cancer, compared the comparison cohort (HR: 1.213; 95% CI: 1.022-1.440; p<0.05 and HR: 7.355; 95% CI: 3.885-13.92; p<0.05, respectively). After adjusting for age, gender, diabetes mellitus, hypertension, hyperlipidemia, gout, geographic region, and income, patients with hyperthyroidism remained at increased risk of cancer incidence and thyroid cancer (Adjusted HR: 1.206; 95% CI: 1.015-1.433 and 6.803; 95% CI: 3.584-12.91, respectively) (both p<0.05). The longer the duration of hyperthyroidism, the greater the risk of thyroid cancer. This 4-year follow up study suggests that patients with hyperthyroidism are at increased risk of cancer, especially thyroid cancer. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

Hyperthyroidism and female urinary incontinence: a population-based cohort study.

PubMed

Chung, Shiu-Dong; Chen, Yi-Kuang; Chen, Yi-Hua; Lin, Herng-Ching

2011-11-01

The imbalanced autonomic nervous system present in hyperthyroidism may cause lower urinary tract symptoms. Urinary incontinence (UI) is the most bothersome lower urinary tract symptom; however, in the literature, reports regarding urinary dysfunction and/or incontinence among hyperthyroid patients are scarce. This population-based cohort study aimed to examine the relationship between hyperthyroidism in women and the risk of developing UI in Taiwan. This study used data from the Longitudinal Health Insurance Database. For this study, 10,817 female patients diagnosed with hyperthyroidism from 2001 to 2005 were recruited together with a comparison cohort of 54,085 matched enrollees who did not have a history of hyperthyroidism. All patients were tracked for a 3-year period from their index date to identify those who had a subsequent UI. The stratified Cox proportional hazards models were used to compute the risk of UI between study and comparison cohorts. During the follow-up period, of 64,169 patients, 173 (1·60%) from the hyperthyroidism group and 560 (1·04%) from the comparison group, had a diagnosis of UI. The regression analysis showed that, after adjusting for monthly income, geographic region, urbanization level of the community in which the patient resided, obesity and hysterectomy, patients with hyperthyroidism were more likely to have UI during the 3-year follow-up period than the comparison patients (hazard ratio = 1·54; 95% CI = 1·30-1·83; P < 0·001). Our results suggest an increased risk of UI in patients with hyperthyroidism at the 3-year follow-up. © 2011 Blackwell Publishing Ltd.

Bladder pain syndrome/interstitial cystitis is associated with hyperthyroidism.

PubMed

Chung, Shiu-Dong; Liu, Shih-Ping; Lin, Ching-Chun; Li, Hsien-Chang; Lin, Herng-Ching

2013-01-01

Although the etiology of bladder pain syndrome/interstitial cystitis (BPS/IC) is still unclear, a common theme with BPS/IC patients is comorbid disorders which are related to the autonomic nervous system that connects the nervous system to end-organs. Nevertheless, no study to date has reported the association between hyperthyroidism and BPS/IC. In this study, we examined the association of IC/BPS with having previously been diagnosed with hyperthyroidism in Taiwan. Data in this study were retrieved from the Longitudinal Health Insurance Database. Our study consisted of 736 female cases with BPS/IC and 2208 randomly selected female controls. We performed a conditional logistic regression to calculate the odds ratio (OR) for having previously been diagnosed with hyperthyroidism between cases and controls. Of the 2944 sampled subjects, there was a significant difference in the prevalence of prior hyperthyroidism between cases and controls (3.3% vs. 1.5%, p<0.001). The conditional logistic regression analysis revealed that compared to controls, the OR for prior hyperthyroidism among cases was 2.16 (95% confidence interval (CI): 1.27∼3.66). Furthermore, the OR for prior hyperthyroidism among cases was 2.01 (95% CI: 1.15∼3.53) compared to controls after adjusting for diabetes, coronary heart disease, obesity, hyperlipidemia, chronic pelvic pain, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, depression, panic disorder, migraines, sicca syndrome, allergies, endometriosis, and asthma. Our study results indicated an association between hyperthyroidism and BPS/IC. We suggest that clinicians treating female subjects with hyperthyroidism be alert to urinary complaints in this population.

Metabolic clearance and blood production rates of estradiol in hyperthyroidism.

PubMed

Ridgway, E C; Longcope, C; Maloof, F

1975-09-01

The metabolic clearance rate of 17beta-estradiol (MCR2), the plasma levels of 17beta-estradiol (E2)1, sex-steroid binding globulin (SSBG), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured in 10 hyperthyroid subjects (7 men and 3 women). The blood production rate of 17beta-estradiol (PB2) was calculated for all subjects. Nine of the 10 hyperthyroid subjects had a decreased MCR2 which returned towards normal in 5 of the 6 subjects restudied following therapy. In all 10 subjects the levels of SSBG were increased when they were hyperthyroid and returned toward normal with therapy. It is concluded that the decrease in MCR2 is largely due to the increased binding of 17beta-estradiol to SSBG. In 7 of the 10 hyperthyroid the plasma E2 concentrations were normal whereas 3 had slightly elevated levels. In 8 of the 10 hyperthyroid the PB2 was within the normal range. Only 2 hyperthyroid subjects had slightly elevated PB2. In the 6 subjects who were restudied after therapy, there was no consistent change in PB2 which remained in the normal range in all cases. It is concluded that the MCR2 is decreased in most subjects with hyperthyroidism in association with an increase of SSBG. Despite this change in MCR2 there is no significant change in PB2. The increase in SSBG levels in hyperthyroidism appears to be a direct effect of the elevation of thyroid hormone activity and is not mediated through estrogen.

Sustained neonatal hyperthyroidism in the rat affects myelination in the central nervous system.

PubMed

Marta, C B; Adamo, A M; Soto, E F; Pasquini, J M

1998-07-15

We have carried out a study of the effects of sustained neonatal hyperthyroidism on myelin and on the oligodendroglial cells, in an effort to obtain further insight into the molecular mechanisms underlying the action of thyroid hormones on the central nervous system (CNS). Expression of the mRNAs of myelin basic protein (MBP) myelin proteolipid protein (PLP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), transferrin, and c-Jun was investigated in 10- and 17-day-old normal and hyperthyroid rats, using Northern blot analysis. At 10 days of age, the levels of all the explored mRNAs were markedly higher in the experimental animals. The mRNA of transferrin showed a ninefold increase over control values, suggesting the possibility that this putative trophic factor might act as one of the mediators in the action of thyroid hormones. At 17 days of age on the other hand, the levels of all the mRNAs decreased markedly, reaching values below control, except for c-Jun, which remained higher than in normals. At 70 days of age, hyperthyroid rats showed clear evidence of myelin deficit, in agreement with previous results of our laboratories (Pasquini et al.: J Neurochem 57: Suppl S124, 1991). Immunocytochemistry of 70-day-old rat brain tissue sections showed a substantial reduction in the amount of MBP-reacting structures and a marked decrease in the number of oligodendroglial cells. Although the above-mentioned results could be the consequence, as proposed by Barres et al. (Development 120:1097-1108, 1994) and Baas et al. (Glia 19:324-332, 1997) of a premature arrest in oligodendroglial cell proliferation followed by early differentiation, the persistent high levels of expression of c-Jun, together with the dramatic decrease in the number of oligodendrocytes, suggested the possibility that prolonged hyperthyroidism could activate apoptotic mechanisms in the myelin forming cells. Using propidium iodide-labeled isolated oligodendroglial cells, we found, by flow cytometry, a significant increase in the number of apoptotic/hypo-diploid propidium iodide-positive cells. These results indicate that one of the actions of sustained levels of thyroid hormones in the neonate rat is to increase oligodendroglial cell death by apoptosis.

Short-Term Memory Performance in 7- and 8-Year-Old Children: The Relationship between Phonological and Pitch Processing

ERIC Educational Resources Information Center

Flagge, Ashley Gaal; Estis, Julie M.; Moore, Robert E.

2016-01-01

Purpose: The relationship between short-term memory for phonology and pitch was explored by examining accuracy scores for typically developing children for 5 experimental tasks: immediate nonword repetition (NWR), nonword repetition with an 8-s silent interference (NWRS), pitch discrimination (PD), pitch discrimination with an 8-s silent…

Impact of Short-Term Training in Social Cognition in Preschoolers with Externalizing Behavior

ERIC Educational Resources Information Center

Houssa, Marine; Jacobs, Emilie; Nader-Grosbois, Nathalie

2017-01-01

In two experimental and exploratory studies, we wanted to test the differentiated effects on preschoolers with externalizing behavior (EB) of two short-term social information processing (SIP) and Theory of Mind (ToM) training sessions, in comparison with typically developing (TD) preschoolers or with preschoolers with EB whom didn't receive…

Drinking High Amounts of Alcohol as a Short-Term Mating Strategy: The Impact of Short-Term Mating Motivations on Young Adults' Drinking Behavior.

PubMed

Vincke, Eveline

2017-01-01

Previous research indicates that drinking large quantities of alcohol could function as a short-term mating strategy for young adults in mating situations. However, no study investigated whether this is actually the case. Therefore, in this article, the link between short-term mating motivations and drinking high amounts of alcohol is tested. First, a survey study ( N = 345) confirmed that young adults who engage in binge drinking are more short-term oriented in their mating strategy than young adults who never engage in binge drinking. Also, the more short-term-oriented young adults were in their mating strategy, the more often binge drinking behavior was conducted. In addition, an experimental study ( N = 229) empirically verified that short-term mating motivations increase young adults' drinking behavior, more so than long-term mating motivations. Results of the experiment clearly showed that young men and young women are triggered to drink more alcoholic beverages in a short-term mating situation compared to a long-term mating situation. Furthermore, the mating situation also affected young adults' perception of drinking behavior. Young adults in a short-term mating context perceived a higher amount of alcoholic beverages as heavy drinking compared to peers in a long-term mating context. These findings confirm that a high alcohol consumption functions as a short-term mating strategy for both young men and young women. Insights gained from this article might be of interest to institutions aimed at targeting youth alcohol (ab)use.

Expression level and clinical significance of IL-2, IL-6 and TGF-β in elderly patients with goiter and hyperthyroidism.

PubMed

Lv, L-F; Jia, H-Y; Zhang, H-F; Hu, Y-X

2017-10-01

To investigate the level of expression and the clinical significance of IL-2 (interleukin-2), IL-6 (interleukin-6) and TGF-β (transforming growth factor-β) in elderly patients with goiter and hyperthyroidism. Gender, age, course of disease, BMI (Body Mass Index), serum FT3 (Free triiodothyronine-3), FT4 (Free triiodothyronine-4), TT3 (Total triiodothyronine-3), TT4 (Total triiodothyronine-4), TSH (Thyroid Stimulating Hormone) and clinical manifestations on admission and other general clinical data and laboratory examination results were collected and statistically analyzed as case group in 128 elderly patients with goiter and hyperthyroidism. Additional 128 over 60-year-old patients with hyperthyroidism were selected as control group. The thyroid tissue of these patients and the control group were examined by fine needle aspiration biopsy. The expressions of IL-2, IL-6, TGF-β of the thyroid tissue in all patients were detected by immunohistochemistry, qRT-PCR (Real-time Quantitative Polymerase Chain Reaction) and Western blot method respectively, and the statistical analysis was carried out. p < 0.05 indicated that the difference had statistical significance. Compared with the control group, the expressions of IL-2, IL-6 and TGF-β in the group of patients were significantly higher (p < 0.05). The significantly higher expression of IL-2, IL-6, and TGF-β was mainly concentrated in the thyroid follicular cells of patients with hyperthyroidism and thyroid enlargement (p < 0.05). In the patients with goiter, hyperthyroidism, and symptoms of exophthalmos, the level of expression of IL-6 was significantly higher than that of patients without exophthalmos (p < 0.05). In the patients with goiter, hyperthyroidism and symptoms of exophthalmos, and the patients with goiter, hyperthyroidism without symptoms of exophthalmos, IL-2 and TGF-β expression level were not different (p > 0.05). The expression levels of IL-2, IL-6, and TGF-β were significantly increased in the patients with senile goiter and hyperthyroidism, but in the senile patients with goiter, hyperthyroidism and exophthalmos symptoms, IL-6 levels were significantly higher than those without exophthalmos. The use of IL-2, IL-6, and TGF-β is of great significance in the diagnosis of goiter with hyperthyroidism, especially for elderly patients with atypical clinical symptoms of hyperthyroidism.

Identification of Two Suppressors of CSG2 Calcium Sensitivity, SCS7 and SUR2, as Genes Encoding Hydroxylases of the Sphingolipid Biosynthetic Pathway of Saccharomyces cerevisiae

DTIC Science & Technology

1997-12-10

process can adjusted by experimental alteration of thyroid status. Hyperthyroidism speeds up the time table while hypothyroidism retards it. When 88... canine kidney MDCK cells. The relative amounts ofthe labeled products can be differentially recovered from the basolateral and apical surfaces of these

Experimental hyperthyroidism decreases gene expression and serum levels of adipokines in obesity.

PubMed

Luvizotto, Renata de Azevedo Melo; do Nascimento, André Ferreira; de Síbio, Maria Teresa; Olímpio, Regiane Marques Castro; Conde, Sandro José; Lima-Leopoldo, Ana Paula; Leopoldo, André Soares; Cicogna, Antonio Carlos; Nogueira, Célia Regina

2012-01-01

To analyze the influence of hyperthyroidism on the gene expression and serum concentration of leptin, resistin, and adiponectin in obese animals. Male Wistar rats were randomly divided into two groups: control (C)-fed with commercial chow ad libitum-and obese (OB)-fed with a hypercaloric diet. After group characterization, the OB rats continued receiving a hypercaloric diet and were randomized into two groups: obese animals (OB) and obese with 25 μg triiodothyronine (T(3))/100 BW (OT). The T(3) dose was administered every day for the last 2 weeks of the study. After 30 weeks the animals were euthanized. Samples of blood and adipose tissue were collected for biochemical and hormonal analyses as well as gene expression of leptin, resistin, and adiponectin. T(3) treatment was effective, increasing fT(3) levels and decreasing fT(4) and TSH serum concentration. Administration of T(3) promotes weight loss, decreases all fat deposits, and diminishes serum levels of leptin, resistin, and adiponectin by reducing their gene expression. Our results suggest that T(3) modulate serum and gene expression levels of leptin, resistin, and adiponectin in experimental model of obesity, providing new insights regarding the relationship between T(3) and adipokines in obesity.

Severe right heart failure in a patient with Grave's disease.

PubMed

Xenopoulos, N P; Braden, G A; Applegate, R J

1996-11-01

This brief report presents a patient with isolated right heart failure and two rare underlying causes, hyperthyroidism and dysplastic tricuspid valve. Repair of the tricuspid valve and treatment of the hyperthyroidism were both essential for successful treatment of the right heart failure. Most important, recrudescence of hyperthyroidism in this patient was associated with reappearance of florid right heart failure. This report provides further information about a potential linkage of hyperthyroidism and severe right heart failure.

Subclinical nonautoimmune hyperthyroidism in a family segregates with a thyrotropin receptor mutation with weakly increased constitutive activity.

PubMed

Nishihara, Eijun; Chen, Chun-Rong; Higashiyama, Takuya; Mizutori-Sasai, Yumiko; Ito, Mitsuru; Kubota, Sumihisa; Amino, Nobuyuki; Miyauchi, Akira; Rapoport, Basil

2010-11-01

Subclinical hyperthyroidism is usually associated with Graves' disease or toxic nodular goiter. Here we report a family with hereditary subclinical hyperthyroidism caused by a constitutively activating germline mutation of the thyrotropin receptor (TSHR) gene. The proband was a 64-year-old Japanese woman who presented with a thyroid nodule and was found to be euthyroid with a suppressed serum TSH. The nodule was not hot. Although antibodies to thyroid peroxidase and thyroglobulin antibodies were present, TSHR antibodies were not detected by TSH-binding inhibition or by bioassay. Two of her middle-aged sons, but not her daughter, also had subclinical hyperthyroidism without TSHR antibodies. Without therapy, the clinical condition of the affected individuals remained unchanged over 3 years without development of overt hyperthyroidism. A novel heterozygous TSHR point mutation causing a glutamic acid to lysine substitution at codon 575 (E575K) in the second extracellular loop was detected in the three family members with subclinical hyperthyroidism, but was absent in her one daughter with normal thyroid function. In vitro functional studies of the E575K TSHR mutation demonstrated a weak, but significant, increase in constitutive activation of the cAMP pathway. Although hereditary nonautoimmune overt hyperthyroidism is very rare, TSHR activating mutations as a cause of subclinical hyperthyroidism may be more common and should be considered in the differential diagnosis, especially if familial.

Age and stress as determinants of the severity of hyperthyroidism caused by Graves' disease in newly diagnosed patients.

PubMed

Vos, Xander G; Smit, Natalie; Endert, Erik; Brosschot, Jos F; Tijssen, Jan G P; Wiersinga, Wilmar M

2009-02-01

The evidence that stress may provoke Graves' hyperthyroidism in genetically susceptible subjects is substantial. Whether exposure to stress is related to the severity of thyrotoxicosis has not been studied. Advancing age is associated with not only less severe Graves' hyperthyroidism but also self-reported stress. We tested the hypothesis whether advancing age is associated with less exposure to stress, resulting in a lower immunological response, and less severe Graves' hyperthyroidism. Cross-sectional multicenter study. Two hundred and sixty-three consecutive untreated patients with a first episode of Graves' hyperthyroidism were included. The severity of Graves' hyperthyroidism was evaluated biochemically (freeT(4)-index and freeT(3)-index, thyrotropin-binding inhibitory immunoglobulin (TBII)) and clinically by the hyperthyroid symptom scale score (HSS score). Stress exposure was quantitated by three questionnaires. Advancing age was associated with less severe Graves' hyperthyroidism, both biochemically by lower serum freeT(3)-index and freeT(4)-index (P<0.01), lower serum TBII (P=0.05), and clinically by lower HSS scores (P=0.04) and smaller goiter size (P<0.01). FreeT(3)-index and freeT(4)-index were directly associated with HSS scores (P<0.01). Stress scores were associated with HSS scores (P<0.01) but not with biochemical severity of Graves' hyperthyroidism. Advancing age was associated with lower scores for stress exposure. Multivariate regression analysis showed that HSS score was independently related to the tendency to report negative feelings (P<0.01) but not to other stress scores and also not to age. Advancing age is associated with less exposure to stress, lower serum TBII and less severe clinical and biochemical Graves' hyperthyroidism. Because no direct relationship exists between stress exposure and TBII or freeT(3)-index and freeT(4)-index, we reject our hypothesis that less stress is causally related to biochemically less severe Graves' hyperthyroidism in old age. HSS score is primarily determined by negative feelings and not by age.

Renin-angiotensin-aldosterone system activity in hyperthyroid cats with and without concurrent hypertension.

PubMed

Williams, T L; Elliott, J; Syme, H M

2013-01-01

Hypertension is present in some hyperthyroid cats at diagnosis or can develop after treatment for hyperthyroidism. Activation of the renin-angiotensin-aldosterone system (RAAS) could be involved in the pathogenesis of hypertension. Hyperthyroid cats that develop hypertension before or after treatment for hyperthyroidism will have greater RAAS activation than normotensive cats. Ninety-nine hyperthyroid cats. Retrospective case-control study. Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured in untreated hyperthyroid hypertensive cats (HT-Pre group), initially normotensive hyperthyroid cats that develop hypertension after treatment (HT-Post group), and hyperthyroid cats that are normotensive (NT group). Data are presented as median [25th, 75th percentile]. Baseline PRA was not significantly different among the 3 groups (HT-Pre group 1.50 [0.05, 2.37] ng/mL/h, HT-Post group 0.66 [0.17, 2.31] ng/mL/h, NT group 1.11 [0.57, 2.18] ng/mL/h; P = .44). PRA decreased significantly after treatment in the NT group (1.09 [0.53, 2.47] versus 0.22 [0.05, 0.76] ng/mL/h; P < .001) and the HT-Post group (0.71 [0.17, 2.33] versus 0.28 [0.07, 0.57] ng/mL/h; P = .006). Baseline PAC was not significantly different among the 3 groups (HT-Pre group 72.2 [40.0, 145.6] pg/mL, HT-Post group 69.7 [43.3, 142.6] pg/mL, NT group 109.0 [68.2, 184.6] pg/mL; P = .10). PAC decreased significantly after treatment in the NT group (114.4 [56.6, 204.1] versus 59.5 [32.4, 98.2] pg/mL; P < .001) but did not change significantly in the HT-Post group (61.2 [44.9, 124.0] versus 58.4 [42.0, 97.7] pg/mL; P = .59). RAAS activation occurs in hyperthyroid cats, but is not associated with the development of hypertension. PAC is not influenced by changes in PRA in hyperthyroid cats that develop hypertension after treatment, perhaps indicating RAAS dysfunction in these cats. Copyright © 2013 by the American College of Veterinary Internal Medicine.

Accelerated characterization of graphite/epoxy composites

NASA Technical Reports Server (NTRS)

Griffith, W. I.; Morris, D. H.; Brinson, H. F.

1980-01-01

A method to predict the long-term compliance of unidirectional off-axis laminates from short-term laboratory tests is presented. The method uses an orthotropic transformation equation and the time-stress-temperature superposition principle. Short-term tests are used to construct master curves for two off-axis unidirectional laminates with fiber angles of 10 deg and 90 deg. In addition, analytical predictions of long-term compliance for 30 deg and 60 deg laminates are made. Comparisons with experimental data are also given.

Hemostasis in Overt and Subclinical Hyperthyroidism

PubMed Central

Ordookhani, Arash; Burman, Kenneth D.

2017-01-01

Context There are contradictory results on the effect of hyperthyroidism on hemostasis. Inadequate population-based studies limited their clinical implications, mainly on the risk of venous thromboembolism (VTE). The present review focuses on hemostatic changes in overt and subclinical hyperthyroidism. Methods A systematic literature search was conducted employing MEDLINE database. The following words were used for the search: Hyperthyroidism; thyrotoxicosis; Graves disease; goiter, nodular; hemostasis; blood coagulation factors; blood coagulation disorders; venous thromboembolism; bleeding; fibrinolysis. The articles that were related to hyperthyroidism and hemostasis are used in this manuscript. Results Hyperthyroidism, either overt or subclinical, renders a hypercoagulable state, although there are several studies with contradictory findings in the literature. Hypercoagulability may be caused by an increase in the level of various coagulation factors such as factor (F) VIII, FX, FIX, von Willebrand F (vWF), and fibrinogen, while hypofibrinolysis by changes in coagulation parameters such as a decrease in plasmin and plasmin activator or an increase in α2-antiplasmin, plasminogen activator inhibitor-1 and thrombin activatable fibrinolysis inhibitor Conclusions Although many reports are in favor of a hypercoagulable state in overt hyperthyroidism but this finding at the biochemical level and its clinical implication, on the occurrence of VTE, has yet to be confirmed. PMID:29201071

Interventions for preventing and treating hyperthyroidism in pregnancy.

PubMed

Earl, Rachel; Crowther, Caroline A; Middleton, Philippa

2010-09-08

Women with hyperthyroidism in pregnancy have increased risks of miscarriage, stillbirth, preterm birth, and intrauterine growth restriction; and they can develop severe pre-eclampsia or placental abruption. To assess the effects of interventions for preventing or treating hyperthyroidism in pregnant women. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 July 2010). We intended to include randomised controlled trials comparing antithyroid treatments in pregnant women with hyperthyroidism. Two review authors would have assessed trial eligibility and risk of bias, and extracted data. No trials were located. As we did not identify any eligible trials, we are unable to comment on implications for practice, although early identification of hyperthyroidism before pregnancy may allow a woman to choose radioactive iodine therapy or surgery before planning to have a child. Designing and conducting a trial of antithyroid drugs for pregnant women with hyperthyroidism presents formidable challenges. Not only is hyperthyroidism a relatively rare condition, both of the two main drugs used have potential for harm, one for the mother and the other for the child. More observational research is required about the potential harms of methimazole in early pregnancy and about the potential liver damage from propylthiouracil.

Therapy of hyperthyroidism in pregnancy and breastfeeding.

PubMed

Fumarola, Angela; Di Fiore, Agnese; Dainelli, Michela; Grani, Giorgio; Carbotta, Giovanni; Calvanese, Anna

2011-06-01

Uncontrolled hyperthyroidism in pregnancy is associated with an increased risk of perinatal complications. The state of the art discussed here has been derived through a wide MEDLINE search throughout English-language literature by using a combination of words such as hyperthyroidism, propylthiouracil (PTU), methimazole, rituximab, and pregnancy to identify original related works and review articles. Thioamides are the main first-line therapeutic options, whereas beta-blockers and iodine are second-choice drugs; surgery is resorted to only in exceptional cases. Methimazole and PTU reduce the production of thyroid hormones by selectively inhibiting thyroid peroxidase. PTU was once considered to be the first-choice drug in the treatment of gestational hyperthyroidism; however, the United States Food and Drug Administration now recommends it as a second-line thioamide, which should be used solely by women in their first trimester of pregnancy. Thyroidectomy is to be carried out only in pregnant women affected by life-threatening, uncontrollable hyperthyroidism, or in cases with thioamide intolerance. Obstetricians & Gynecologists, Family Physicians After completion of this article, the physician should be better able to choose appropriate therapies for hyperthyroidism in pregnant women, assess the risk of possible complications due to maternal hyperthyroidism, and evaluate strategies for patient follow-up.

Effect of hyperthyroidism on spontaneous physical activity and energy expenditure in rats.

PubMed

Levine, James A; Nygren, Jonas; Short, Kevin R; Nair, K Sreekumaran

2003-01-01

Thyroid hormone excess is associated with increased energy expenditure. The contributions of increases in spontaneous physical activity and nonexercise activity thermogenesis (NEAT) to this effect have not been defined. To address the hypothesis that hyperthyroidism is associated with increased spontaneous physical activity and NEAT, we rendered rats hyperthyroid by using continuous infusion of high-dose triiodothyronine for 14 days and measured the effects on physical activity and NEAT. On day 14, in the hyperthyroid group the mean +/- SD triiodothyronine concentration was 755 +/- 137 (range 574-919) ng/dl and in the control group 59 +/- 0.5 (58-59) ng/dl. Over the 14-day treatment period, mean spontaneous physical activity increased in the hyperthyroid rats from 24 +/- 7 to 36 +/- 6 activity units (AU)/min; P < 0.001 but did not increase in the controls (23 +/- 7 vs. 22 +/- 4 AU/min). Also, over the 14-day period, daily NEAT increased in the hyperthyroid rats from 8.1 +/- 2.8 to 19.7 +/- 5.0 kcal/day (P < 0.001) but did not increase in the controls (8.7 +/- 3.5 cf 9.4 +/- 1.7 kcal/day; not significant). In conclusion, hyperthyroidism is associated with increased spontaneous physical activity and NEAT.

Hyperthyroidism association with SLE, lessons from real-life data--A case-control study.

PubMed

Watad, Abdulla; Cohen, Arnon D; Comaneshter, Doron; Tekes-Manova, Dorit; Amital, Howard

2016-01-01

Despite the frequently encountered association between thyroid disease and systemic lupus erythematosus (SLE) is well known, it is of surprise that only several reports compromised of small population size support this observation. To investigate the association of comorbid SLE and hyperthyroidism. Using the database of the largest health maintenance organization (HMO) in Israel, the Clalit Health Services, we searched for the co-existence of SLE and hyperthyroidism. Patients with SLE were compared with age- and sex-matched controls regarding the prevalence of hyperthyroidism in a case-control study. Chi-square and t-tests were used for univariate analysis and a logistic regression model was used for multivariate analysis. The study included 5018 patients with SLE and 25,090 age- and sex- matched controls. The prevalence of hyperthyroidism in patients with SLE was increased compared with the prevalence in controls (2.59% and 0.91%, respectively, p < 0.001). In a multivariate analysis, SLE was associated with hyperthyroidism (odds ratio 2.52, 95% confidence interval 2.028-3.137). Patients with SLE have a greater prevalence of hyperthyroidism than matched controls. Therefore, physicians treating patients with SLE should be aware of this possibility of this thyroid dysfunction.

Cardiovascular involvement in patients with different causes of hyperthyroidism.

PubMed

Biondi, Bernadette; Kahaly, George J

2010-08-01

Various clinical disorders can cause hyperthyroidism, the effects of which vary according to the patient's age, severity of clinical presentation and association with other comorbidities. Hyperthyroidism is associated with increased morbidity and mortality from cardiovascular disease, although whether the risk of specific cardiovascular complications is related to the etiology of hyperthyroidism is unknown. This article will focus on patients with Graves disease, toxic adenoma and toxic multinodular goiter, and will compare the cardiovascular risks associated with these diseases. Patients with toxic multinodular goiter have a higher cardiovascular risk than do patients with Graves disease, although cardiovascular complications in both groups are differentially influenced by the patient's age and the cause of hyperthyroidism. Atrial fibrillation, atrial enlargement and congestive heart failure are important cardiac complications of hyperthyroidism and are prevalent in patients aged > or = 60 years with toxic multinodular goiter, particularly in those with underlying cardiac disease. An increased risk of stroke is common in patients > 65 years of age with atrial fibrillation. Graves disease is linked with autoimmune complications, such as cardiac valve involvement, pulmonary arterial hypertension and specific cardiomyopathy. Consequently, the etiology of hyperthyroidism must be established to enable correct treatment of the disease and the cardiovascular complications.

Hyperthyroid-associated osteoporosis is exacerbated by the loss of TSH signaling

USDA-ARS?s Scientific Manuscript database

The osteoporosis associated with human hyperthyroidism has traditionally been attributed to elevated thyroid hormone levels. There is evidence, however, that thyroid-stimulating hormone (TSH), which is low in most hyperthyroid states, directly affects the skeleton. Importantly, Tshr-knockout mice ar...

Hyperthyroidism

PubMed Central

Whitner, Tanya E.; Hudson, Christopher J.; Smith, Timothy D.; Littmann, Laszlo

2005-01-01

Although hyperthyroidism has many signs and symptoms, right heart failure can occasionally be the main presenting symptom. We describe the case of a previously healthy 42-year-old woman whose chief complaint was progressive bilateral lower extremity edema. The echocardiogram revealed right atrial dilatation and moderate-to-severe tricuspid regurgitation. Results of laboratory studies were consistent with hyperthyroidism. Thyroid ablation resulted in permanent resolution of symptoms and resolution of tricuspid incompetence on echocardiography. In a case of isolated, unexplained tricuspid regurgitation, it is important to consider indolent hyperthyroidism in the differential diagnosis. PMID:16107128

Atypical Manifestations of Hyperthyroidism

PubMed Central

Boxall, E. A.; Lauener, R. W.; McIntosh, H. W.

1964-01-01

Patients with hyperthyroidism usually present with symptoms of hypermetabolism with or without goitre and/or eye signs. Occasionally, however, the chief complaints are not immediately suggestive of hyperthyroidism. Patients with hyperthyroidism are described who presented with such atypical manifestations as periodic muscular paralysis, myasthenia, myopathy, encephalopathy, psychosis, angina pectoris, atrial fibrillation, heart failure without underlying heart disease, skeletal demineralization, pretibial myxedema, unilateral eye signs, and pitting edema of the ankles. ImagesFig. 2Fig. 3Fig. 5Fig. 7Fig. 8Fig. 9Fig. 10 PMID:14178405

Hyperthyroidism and Hypothyroidism in Male Mice and Their Effects on Bone Mass, Bone Turnover, and the Wnt Inhibitors Sclerostin and Dickkopf-1.

PubMed

Tsourdi, Elena; Rijntjes, Eddy; Köhrle, Josef; Hofbauer, Lorenz C; Rauner, Martina

2015-10-01

Thyroid hormones are key regulators of bone homeostasis, and Wnt signaling has been implicated in thyroid hormone-associated bone loss. Here we tested whether hyperthyroidism and hypothyroidism interfere with dickkopf-1 (DKK1) and sclerostin, two inhibitors of Wnt signaling. Twelve-week-old male C57BL/6 mice were rendered either hyperthyroid or hypothyroid. Hyperthyroid mice displayed decreased trabecular (-54%, P < .001) and cortical bone density (-5%, P < .05) and reduced cortical thickness (-15%, P < .001), whereas hypothyroid mice showed a higher trabecular bone density (+26%, P < .001) with unchanged cortical bone parameters. Histomorphometry and biochemical markers of bone remodeling indicated high bone turnover in hyperthyroid mice and low bone turnover in hypothyroid mice. In vivo, serum DKK1 concentrations were decreased in hyperthyroid mice (-24%, P < .001) and increased in hypothyroid mice (+18%, P < .01). The increase of the number of DKK1-positive cells in hypothyroid mice was confirmed at the tissue level. Interestingly, sclerostin was increased in both disease models, although to a higher extent in hyperthyroid mice (+50%, P < .001, and +24%, P < .05). Serum sclerostin concentrations adjusted for bone mass were increased by 3.3-fold in hyperthyroid (P < .001) but not in hypothyroid mice. Consistently, sclerostin mRNA expression and the number of sclerostin-positive cells were increased in hyperthyroid but not in hypothyroid mice. Our data show that thyroid hormone-induced changes in bone remodeling are associated with a divergent regulation of DKK1 and sclerostin. Thus, the modulation of Wnt signaling by thyroid hormones may contribute to thyroid hormone-associated bone disease and altered expression of Wnt inhibitors may emerge as potential therapeutic targets.

Histomorphometry and expression of Cdc47 and caspase-3 in hyperthyroid rat uteri and placentas during gestation and postpartum associated with fetal development.

PubMed

Freitas, E S; Leite, E D; Souza, C A; Ocarino, N M; Ferreira, E; Cassali, G D; Gomes, M G; Serakides, R

2007-01-01

In two different experiments, the effects of hyperthyroidism on the histomorphometry and expression of Cdc47 and caspase-3 were evaluated in the uteri and placentas during gestation and postpartum. Fetal development was also evaluated during gestation. In the first experiment, 36 adult female Wistar rats were divided into two groups of 18 animals each: (1) hyperthyroid; and (2) euthyroid (control). Female rats were mated and killed at 7, 14 and 19 days of gestation. Uteri and placentas were weighed and subjected to histomorphometric and immunohistochemical evaluation to determine the expression of Cdc47 and caspase-3. Ovaries were also evaluated for weight and subjected to morphometric analysis. Fetuses were quantified and weighed individually. In the second experiment, 12 adult female Wistar rats were divided into two groups of six animals each: (1) hyperthyroid; and (2) euthyroid (control). Female rats were mated and killed 2 days postpartum. Uteri were evaluated in the same way as for the first experiment. Hyperthyroidism increased ovulation and conception rates without disturbing the size and viability of the fetuses. In the pregnant uteri, hyperthyroidism did not change the thickness of the layers or the expression of Cdc47 and caspase-3. However, in the placentas, hyperthyroidism increased the medium diameter of trophoblast cells, as well as the thickness and the expression of Cdc47 of spongiotrophoblast cells, at 14 days of gestation. During uterine involution, hyperthyroidism significantly increased the expression of Cdc47 and reduced the expression of caspase-3 in the uterine layers. In conclusion, hyperthyroidism increased the conception rate because of an ovulation gain, induced significant placental changes during pregnancy and, in the uterus, increased Cdc47 expression and decreased caspase-3 expression after parturition.

Spontaneous Abortion, Stillbirth and Hyperthyroidism: A Danish Population-Based Study

PubMed Central

Andersen, Stine Linding; Olsen, Jørn; Wu, Chun Sen; Laurberg, Peter

2014-01-01

Objectives Pregnancy loss in women suffering from hyperthyroidism has been described in case reports, but the risk of pregnancy loss caused by maternal hyperthyroidism in a population is unknown. We aimed to evaluate the association between maternal hyperthyroidism and pregnancy loss in a population-based cohort study. Study Design All pregnancies in Denmark from 1997 to 2008 leading to hospital visits (n = 1,062,862) were identified in nationwide registers together with information on maternal hyperthyroidism for up to 2 years after the pregnancy [hospital diagnosis/prescription of antithyroid drug (ATD)]. The Cox proportional hazards model was used to estimate adjusted hazard ratio (aHR) with 95% confidence interval (CI) for spontaneous abortion (gestational age <22 weeks) and stillbirth (≥22 weeks), reference: no maternal thyroid dysfunction. Results When maternal hyperthyroidism was diagnosed before/during the pregnancy (n = 5,229), spontaneous abortion occurred more often both in women treated before the pregnancy alone [aHR 1.28 (95% CI 1.18-1.40)] and in women treated with ATD in early pregnancy [1.18 (1.07-1.31)]. When maternal hyperthyroidism was diagnosed and treated for the first time in the 2-year period after the pregnancy (n = 2,361), there was a high risk that the pregnancy under study had terminated with a stillbirth [2.12 (1.30-3.47)]. Conclusions Both early (spontaneous abortion) and late (stillbirth) pregnancy loss were more common in women suffering from hyperthyroidism. Inadequately treated hyperthyroidism in early pregnancy may have been involved in spontaneous abortion, and undetected high maternal thyroid hormone levels present in late pregnancy may have attributed to an increased risk of stillbirth. PMID:25538898

A comparison of 20 or 40 mg per day of carbimazole in the initial treatment of hyperthyroidism.

PubMed

Page, S R; Sheard, C E; Herbert, M; Hopton, M; Jeffcoate, W J

1996-11-01

The optimal dosage regimen for carbimazole (CBZ) in the treatment of hyperthyroidism remains uncertain, despite clinical use of the drug for approximately fifty years. We have compared the early clinical and biochemical responses to 20 or 40 mg/day of CBZ given as initial treatment for hyperthyroidism. Prospective open multicentre trial. Sixty-three patients presenting with hyperthyroidism. Serum total and free thyroid hormones, serum TSH and SHBG were measured at baseline and at 4 and 10 weeks after start of therapy. Weight, pulse and a symptom questionnaire were also monitored at 6 and 12 weeks. Patients randomized to a starting dose of 40 mg/day CBZ had lower total (98 +/- 10 vs 158 +/- 11 nmol/l, P < 0.001) and free T4 (19.4 +/- 2.6 vs 35.2 +/- 3.7 pmol/l, P < 0.001) and total (2.6 +/- 0.3 vs 4.3 +/- 0.4 nmol/l, P < 0.001) and free T3 (8.3 +/- 1.0 vs 13.7 +/- 1.2 pmol/l, P < 0.01) at 4 weeks than those receiving 20 mg/day. Clinical responses at 6 and 12 weeks (weight, pulse, symptom score) and SHBG concentrations were similar. Drug-related hypothyroidism was less likely to occur at 4 and 10 weeks in those patient who initially received 20 mg CBZ/day, but this dose was less effective at controlling hyperthyroidism in those with more severe hyperthyroidism with baseline TT4 > 260 nmol/l. In treating hyperthyroidism, 20 mg/day carbimazole is effective, convenient and has a lower risk than 40 mg/day of iatrogenic hypothyroidism in patients with mild or moderate hyperthyroidism. Higher doses are required for those with severe hyperthyroidism.

Relationship Among Pulmonary Hypertension, Autoimmunity, Thyroid Hormones and Dyspnea in Patients With Hyperthyroidism.

PubMed

Zuhur, Sayid Shafi; Baykiz, Derya; Kara, Sonat Pinar; Sahin, Ertan; Kuzu, Idris; Elbuken, Gulsah

2017-04-01

Previous studies have reported conflicting results regarding the mechanisms underlying the pathophysiology of pulmonary hypertension (PHT) in patients with hyperthyroidism. Therefore, in this study, we investigated the association between PHT and thyroid-stimulating hormone (TSH) receptor antibody, thyroid peroxidase antibody, thyroglobulin antibody, TSH, fT3, fT4 and dyspnea during daily activities in a large population of patients with hyperthyroidism. A total of 129 consecutive patients with hyperthyroidism, 37 with hypothyroidism and 38 euthyroid controls were enrolled in this study. The modified medical research council scale was used for the assessment of dyspnea in daily activities. All the patients and euthyroid controls underwent transthoracic echocardiography for the assessment of PHT. Mild PHT was present in 35%, 36%, 13.5% and 5% of the patients with Graves׳ disease, toxic multinodular goiter, hypothyroidism and euthyroid controls, respectively. Pulmonary vascular resistance (PVR) was higher in hyperthyroid patients with PHT than in those without PHT. Moreover, a significant positive correlation was found between modified medical research council scale and pulmonary artery systolic pressure as well as PVR in patients with hyperthyroidism. No association was found between PHT and serum TSH receptor antibody, thyroid peroxidase antibody, thyroglobulin antibody, TSH, fT3 and fT4 levels. Mild PHT is present in a significant proportion of patients with hyperthyroidism, regardless of etiology. PVR appears to be the main cause of PHT in patients with hyperthyroidism, and neither autoimmunity nor thyroid hormones are associated with PHT in these patients. Mild dyspnea during daily activities in patients with hyperthyroidism may be related to PHT; however, severe dyspnea requires further evaluation. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Work capacity and oxygen uptake abnormalities in hyperthyroidism.

PubMed

Irace, L; Pergola, V; Di Salvo, G; Perna, B; Tedesco, M A; Ricci, C; Tuccillo, B; Iacono, A

2006-06-01

The aim of our study was to evaluate the haemodynamic and the respiratory response to exercise in patients with hyperthyroidism before and 30 days after normalized thyroid hormones levels. These findings were compared with those of 10 control patients. Thirty patients (23 women, aged 34.3 +/- 12 years) with untreated hyperthyroidism were studied. Twenty-four patients were treated with methimazole, 13 of which were also treated with propranolol. Six patients underwent surgery. A symptom-limited cardiopulmonary exercise test and an echocardiography were performed in all patients. At rest patients with hyperthyroidism showed at echocardiography an increased cardiac index (P = 0.006 vs euthyroid, P = 0.007 vs normal) and a higher ejection fraction (P = 0.008 vs euthyroid, P = 0.007 vs normal). The duration of the exercise was lower in hyperthyroid patients (P = 0.006 vs euthyroid; P = 0.0068 vs normal). Anaerobic threshold was reached at 49.6% of peak VO2 during hyperthyroidism, at 60.8% during euthyroidism (P = 0.01) and at 62% in normal (P = 0.01). Work rate was lower in patients with hyperthyroidism at anaerobic threshold (P = 0.01 vs euthyroid, P = 0.03 vs normal) and at maximal work (P = 0.001 vs euthyroid, P = 0.01 vs normal). Patients in hyperthyroidism showed a lower increment of heart rate between rest and anaerobic threshold (P = 0.021 vs euthyroid, P < 0.0001 vs normal) and a lower VO2 at anaerobic threshold (P = 0.03 vs euthyroid; P = 0.04 vs normal). Oxygen pulse at anaerobic threshold was significantly reduced in hyperthyroidism (P = 0.04 vs euthyroid, P = 0.005 vs normal). The mean result is that after only 30 days of appropriate antithyroid treatment there was an appreciable improvement of exertion capacity.

Hyperthyroidism is characterized by both increased sympathetic and decreased vagal modulation of heart rate: evidence from spectral analysis of heart rate variability.

PubMed

Chen, Jin-Long; Chiu, Hung-Wen; Tseng, Yin-Jiun; Chu, Woei-Chyn

2006-06-01

The clinical manifestations of hyperthyroidism resemble those of the hyperadrenergic state. This study was designed to evaluate the impact of hyperthyroidism on the autonomic nervous system (ANS) and to investigate the relationship between serum thyroid hormone concentrations and parameters of spectral heart rate variability (HRV) analysis in hyperthyroidism. Thirty-two hyperthyroid Graves' disease patients (mean age 31 years) and 32 sex-, age-, and body mass index (BMI)-matched normal control subjects were recruited to receive one-channel electrocardiogram (ECG) recording. The cardiac autonomic nervous function was evaluated by the spectral analysis of HRV, which indicates the autonomic modulation of the sinus node. The correlation coefficients between serum thyroid hormone concentrations and parameters of the spectral HRV analysis were also computed. The hyperthyroid patients revealed significant differences (P < 0.001) compared with the controls in the following HRV parameters: a decrease in total power (TP), very low frequency power (VLF), low frequency power (LF), high frequency power (HF), and HF in normalized units (HF%); and an increase in LF in normalized units (LF%) and in the ratio of LF to HF (LF/HF). After correction of hyperthyroidism in 28 patients, all of the above parameters were restored to levels comparable to those of the controls. In addition, serum thyroid hormone concentrations showed significant correlations with spectral HRV parameters. Hyperthyroidism is in a sympathovagal imbalanced state, characterized by both increased sympathetic and decreased vagal modulation of the heart rate. These autonomic dysfunctions can be detected simultaneously by spectral analysis of HRV, and the spectral HRV parameters could reflect the disease severity in hyperthyroid patients.

Quiet Clean Short-Haul Experimental Engine (QCSEE): Acoustic treatment development and design

NASA Technical Reports Server (NTRS)

Clemons, A.

1979-01-01

Acoustic treatment designs for the quiet clean short-haul experimental engines are defined. The procedures used in the development of each noise-source suppressor device are presented and discussed in detail. A complete description of all treatment concepts considered and the test facilities utilized in obtaining background data used in treatment development are also described. Additional supporting investigations that are complementary to the treatment development work are presented. The expected suppression results for each treatment configuration are given in terms of delta SPL versus frequency and in terms of delta PNdB.

BROMINATED-FLAME RETARDANTS (BFRS) IN CATS – POSSIBLE LINKAGE TO FELINE HYPERTHYROIDISM?

EPA Science Inventory

Coincident with global introduction of BFRs into house¬hold consumer products nearly 30 years ago, hyperthyroidism in cats has increased considerably. The etiopathogenesis of feline hyperthyroidism remains unknown. We hypothesized that increasing exposure of pet cats to BFRs such...

Forecasting the Short-Term Passenger Flow on High-Speed Railway with Neural Networks

PubMed Central

Xie, Mei-Quan; Li, Xia-Miao; Zhou, Wen-Liang; Fu, Yan-Bing

2014-01-01

Short-term passenger flow forecasting is an important component of transportation systems. The forecasting result can be applied to support transportation system operation and management such as operation planning and revenue management. In this paper, a divide-and-conquer method based on neural network and origin-destination (OD) matrix estimation is developed to forecast the short-term passenger flow in high-speed railway system. There are three steps in the forecasting method. Firstly, the numbers of passengers who arrive at each station or depart from each station are obtained from historical passenger flow data, which are OD matrices in this paper. Secondly, short-term passenger flow forecasting of the numbers of passengers who arrive at each station or depart from each station based on neural network is realized. At last, the OD matrices in short-term time are obtained with an OD matrix estimation method. The experimental results indicate that the proposed divide-and-conquer method performs well in forecasting the short-term passenger flow on high-speed railway. PMID:25544838

A Probabilistic Clustering Theory of the Organization of Visual Short-Term Memory

ERIC Educational Resources Information Center

Orhan, A. Emin; Jacobs, Robert A.

2013-01-01

Experimental evidence suggests that the content of a memory for even a simple display encoded in visual short-term memory (VSTM) can be very complex. VSTM uses organizational processes that make the representation of an item dependent on the feature values of all displayed items as well as on these items' representations. Here, we develop a…

An Empirical Assessment of Selected Software Purported to Raise SAT Scores Significantly When Utilized With Short-Term CAI on the Microcomputer.

ERIC Educational Resources Information Center

Davis, Wesley D.

This study evaluated Krell's 1981-82 Scholastic Aptitude Test (SAT) preparatory series software purported to raise students' scores substantially after only a short term of computer-assisted instruction (CAI). Forty-eight college-bound juniors from Escambia County (Florida) were assigned to experimental and control groups. A two-phased pre- and…

Serum nesfatin-1 levels in overt and subclinical hyperthyroidism.

PubMed

Gungunes, A; Ozbek, M; Ginis, Z; Sahin, M; Demirci, T; Cakir Ozkaya, E; Karbek, B; Sayki Arslan, M; Ozturk Unsal, I; Tutal Akkaya, E; Ucan, B; Gultuna Ozguclu, S; Cakal, E; Topaloglu, O; Delibasi, T

2014-09-01

Nesfatin-1 was recently discovered anorexigenic peptide in the brain which is derived from nucleobindin-2. Central and peripheral administration of nesfatin-1, inhibits food intake, dose-dependently. Hyperthyroid patients have increased appetite and food intake with a craving for carbohydrate-rich food, at the beginning of disease, but the physiological mechanisms underlying this behavior is not known exactly. In this study, we investigated whether nesfatin-1 is involved in the regulation of appetite and body weight in hyperthyroidism, or not. A total of 70 patients with subclinical (35) and overt hyperthyroidism (35) compared with 35 control patients. Serum nesfatin-1 level was measured from all samples by commercial ELISA kit. Serum nesfatin-1 levels were similar between three groups (P=0.293). After adjusting for age and body mass index, nesfatin-1 levels in control group was not different from subclinical and overt hyperthyroid group, respectively (P=0.567 and P=0.519). These data showed that serum nesfatin-1 levels do not significant change in overt and subclinical hyperthyroidism.

High prevalence of iatrogenic hyperthyroidism in elderly patients with atrial fibrillation in an anticoagulation clinic.

PubMed

Krishnan, Sandeep Kumar; Dohrmann, Mary L; Brietzke, Stephen A; Fleming, David A; Flaker, Greg C

2011-01-01

In elderly patients with established atrial fibrillation (AF) who are receiving thyroid replacement, regular testing for thyroid function is often not performed, placing the patient at risk for iatrogenic hyperthyroidism. Of 215 patients followed in an anticoagulation clinic, 41 were receiving thyroid replacement and 15 of these were found to have hyperthyroidism. Eight had documented AF coincident with abnormal thyroid function. In addition, only 22 patients on thyroid replacement had an annual TSH. In conclusion, iatrogenic hyperthyroidism may frequently be missed in AF patients because of inadequate monitoring of serum TSH. Thyroid replacement is common in elderly patients with AF followed in an anticoagulation clinic. Laboratory evidence of hyperthyroidism occurred in 37%, usually in patients with higher doses of thyroid replacement, and often associated with AF. The frequency of iatrogenic hyperthyroidism may be underestimated in patients with AF since many patients who receive thyroid replacement therapy are not monitored regularly with serum TSH.

Red cell changes in hyperthyroidism.

PubMed

How, J; Davidson, R J; Bewsher, P D

1979-10-01

The Coulter 'S' red cell profile was studied prospectively in 100 untreated non-anaemic hyperthyroid patients and followed up in 52 of them until they had become euthyroid with radio-iodine or carbimazole treatment. Serial haematological data were also obtained in 23 hyperthyroid patients during treatment with beta-adrenoreceptor blocking drug alone. The most significant finding was a low mean corpuscular volume (MCV) which was invariably present throughout the hyperthyroid state. Treatment with beta-adrenoreceptor blocking drugs did not significantly alter any of the red cell parameters. On the other hand, the MCV increased and was restored to normal with radio-iodine or carbimazole treatment although there was a lag period of about 6--8 weeks between achieving the euthyroid state and the normalisation of this red cell index. While none of the patients were aneaemic, the haemoglobin level rose significantly following effective anti-thyroid treatment. It is suggested that measurement of the MCV may have a useful role in the diagnosis of hyperthyroidism. 2 possible mechanisms leading to the observed red cell changes in hyperthyroidism are postulated.

Hyperthyroidism differentially regulates neuropeptide S system in the rat brain.

PubMed

González, Carmen R; Martínez de Morentin, Pablo B; Martínez-Sánchez, Noelia; Gómez-Díaz, Consuelo; Lage, Ricardo; Varela, Luis; Diéguez, Carlos; Nogueiras, Rubén; Castaño, Justo P; López, Miguel

2012-04-23

Thyroid hormones play an important role in the regulation of energy balance, sleep and emotional behaviors. Neuropeptide S (NPS) is a recently discovered neuropeptide, regulating feeding, sleep and anxiety. Here, we examined the effect of hyperthyroidism on the gene and protein expression of neuropeptide S and its receptor (NPS-R) in the hypothalamus, brainstem and amygdala of rats. Our results showed that the expression of NPS and NPS-R was differentially modulated by hyperthyroidism in the rat brain. NPS and NPS-R mRNA and protein levels were decreased in the hypothalamus of hyperthyroid rats. Conversely NPS-R expression was highly increased in the brainstem and NPS and NPS-R expression were unchanged in the amygdala of these rats. These data suggest that changes in anxiety and food intake patterns observed in hyperthyroidism could be associated with changes in the expression of NPS and NPS-R. Thus, the NPS/NPS-R system may be involved in several hyperthyroidism-associated comorbidities. Copyright © 2012 Elsevier B.V. All rights reserved.

[Heart failure as early manifestation of neonatal hyperthyroidism. Case report].

PubMed

Alvarado S, Jorge Luis; Fernández V, Zhirly Andrea

2014-04-01

Neonatal hyperthyroidism is usually a self-limited condition frequently associated with transplacental passage of thyroid stimulating antibodies secondary to maternal autoimmune disorders. To timely detect mothers with this medical antecedents decreases the risk for fetal adverse events. To report a case of neonatal hyperthyroidism associated with intrauterine growth restriction and heart failure. A 36 week-old newborn with birth weight of 1,240 g. Symptoms were tachycardia, distal coldness, exophthalmos, hepatomegaly and tremors. Echocardiogram ruled out structural heart disorders. Due to maternal symptoms suggestive of hyperthyroidism, TSH tests were performed showing 0.01 ulU/ml, free T4 7.7 ng/dl, so the diagnosis of neonatal hyperthyroidism was confirmed. It was treated with methimazole and propanol, alleviating the symptoms and decreasing the levels of free T4. To know the maternal history helps identify and manage neonatal complications of hyperthyroidism. Heart failure and other cardiopulmonary disorders are determinants of mortality during early neonatal period. High-risk newborns should receive follow up assessments.

The skeletal consequences of thyrotoxicosis.

PubMed

Nicholls, Jonathan J; Brassill, Mary Jane; Williams, Graham R; Bassett, J H Duncan

2012-06-01

Euthyroid status is essential for normal skeletal development and the maintenance of adult bone structure and strength. Established thyrotoxicosis has long been recognised as a cause of high bone turnover osteoporosis and fracture but more recent studies have suggested that subclinical hyperthyroidism and long-term suppressive doses of thyroxine (T4) may also result in decreased bone mineral density (BMD) and an increased risk of fragility fracture, particularly in postmenopausal women. Furthermore, large population studies of euthyroid individuals have demonstrated that a hypothalamic-pituitary-thyroid axis set point at the upper end of the normal reference range is associated with reduced BMD and increased fracture susceptibility. Despite these findings, the cellular and molecular mechanisms of thyroid hormone action in bone remain controversial and incompletely understood. In this review, we discuss the role of thyroid hormones in bone and the skeletal consequences of hyperthyroidism.

Comparison of modeled estimates of inhalation exposure to aerosols during use of consumer spray products.

PubMed

Park, Jihoon; Yoon, Chungsik; Lee, Kiyoung

2018-05-30

In the field of exposure science, various exposure assessment models have been developed to complement experimental measurements; however, few studies have been published on their validity. This study compares the estimated inhaled aerosol doses of several inhalation exposure models to experimental measurements of aerosols released from consumer spray products, and then compares deposited doses within different parts of the human respiratory tract according to deposition models. Exposure models, including the European Center for Ecotoxicology of Chemicals Targeted Risk Assessment (ECETOC TRA), the Consumer Exposure Model (CEM), SprayExpo, ConsExpo Web and ConsExpo Nano, were used to estimate the inhaled dose under various exposure scenarios, and modeled and experimental estimates were compared. The deposited dose in different respiratory regions was estimated using the International Commission on Radiological Protection model and multiple-path particle dosimetry models under the assumption of polydispersed particles. The modeled estimates of the inhaled doses were accurate in the short term, i.e., within 10 min of the initial spraying, with a differences from experimental estimates ranging from 0 to 73% among the models. However, the estimates for long-term exposure, i.e., exposure times of several hours, deviated significantly from the experimental estimates in the absence of ventilation. The differences between the experimental and modeled estimates of particle number and surface area were constant over time under ventilated conditions. ConsExpo Nano, as a nano-scale model, showed stable estimates of short-term exposure, with a difference from the experimental estimates of less than 60% for all metrics. The deposited particle estimates were similar among the deposition models, particularly in the nanoparticle range for the head airway and alveolar regions. In conclusion, the results showed that the inhalation exposure models tested in this study are suitable for estimating short-term aerosol exposure (within half an hour), but not for estimating long-term exposure. Copyright © 2018 Elsevier GmbH. All rights reserved.

Chromosomes on the move: The educational and neurological advantages of using body movement to teach cellular division

NASA Astrophysics Data System (ADS)

Baumwoll, Alma Aron

As education and neuroscience begin to merge, creating the new field of brain-based education, teachers are working to integrate scientific research into the classroom. While working to improve my own teaching, I developed a lesson plan to teach mitosis and meiosis through movement. My thesis reviews education theory and neuroscience to support using movement as a teaching tool in high-level, subject-based classrooms. I then outline my lesson plan and present my investigations of its effectiveness as demonstrated through short-term memory, long-term memory, and students' personal responses to the class. Two experiments were completed with biology lab sections at Northeastern University between 2009 and 2012; I taught my lesson to experimental groups while control groups learned through video-based lessons. The short-term study showed significant improvement in both the grades and enjoyment of the experimental groups. The long-term, retroactive study yielded no significant data, possibly due to weaknesses in the experimental design.

Antiarrhythmic effect of tamoxifen on the vulnerability induced by hyperthyroidism to heart ischemia/reperfusion damage.

PubMed

Pavón, Natalia; Hernández-Esquivel, Luz; Buelna-Chontal, Mabel; Chávez, Edmundo

2014-09-01

Hyperthyroidism, known to have deleterious effects on heart function, and is associated with an enhanced metabolic state, implying an increased production of reactive oxygen species. Tamoxifen is a selective antagonist of estrogen receptors. These receptors make the hyperthyroid heart more susceptible to ischemia/reperfusion. Tamoxifen is also well-known as an antioxidant. The aim of the present study was to explore the possible protective effect of tamoxifen on heart function in hyperthyroid rats. Rats were injected daily with 3,5,3'-triiodothyronine at 2mg/kg body weight during 5 days to induce hyperthyroidism. One group was treated with 10mg/kg tamoxifen and another was not. The protective effect of the drug on heart rhythm was analyzed after 5 min of coronary occlusion followed by 5 min reperfusion. In hyperthyroid rats not treated with tamoxifen, ECG tracings showed post-reperfusion arrhythmias, and heart mitochondria isolated from the ventricular free wall lost the ability to accumulate and retain matrix Ca(2+) and to form a high electric gradient. Both of these adverse effects were avoided with tamoxifen treatment. Hyperthyroidism-induced oxidative stress caused inhibition of cis-aconitase and disruption of mitochondrial DNA, effects which were also avoided by tamoxifen treatment. The current results support the idea that tamoxifen inhibits the hypersensitivity of hyperthyroid rat myocardium to reperfusion damage, probably because its antioxidant activity inhibits the mitochondrial permeability transition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Food choice in hyperthyroidism: potential influence of the autonomic nervous system and brain serotonin precursor availability.

PubMed

Pijl, H; de Meijer, P H; Langius, J; Coenegracht, C I; van den Berk, A H; Chandie Shaw, P K; Boom, H; Schoemaker, R C; Cohen, A F; Burggraaf, J; Meinders, A E

2001-12-01

We explored energy and macronutrient intake in patients with Graves' hyperthyroidism. We specifically hypothesized that hyperthyroidism is associated with increased appetite for carbohydrates, because of enhanced sympathetic tone and diminished serotonin mediated neurotransmission in the brain. To test this hypothesis, we measured food intake by dietary history and food selected for lunch in the laboratory in 14 patients with Graves' hyperthyroidism. Twenty-four-hour catecholamine excretion was used as a measure of activity of the sympathetic nervous system (SNS) and the plasma [Trp]/[NAA] ratio was measured to estimate (rate limiting) precursor availability for brain 5-hydroxytryptamine synthesis. All measurements were repeated after the subjects had been treated to establish euthyroidism. In addition, the effects of nonselective beta-adrenoceptor blockade upon these parameters were studied to evaluate the influence of beta-adrenergic hyperactivity on food intake. Hyperthyroidism was marked by increased SNS activity and reduced plasma [Trp]/[NAA] ratio. Accordingly, energy intake was considerably and significantly increased in hyper vs. euthyroidism, which was fully attributable to enhanced carbohydrate consumption, as protein and fat intake were not affected. These results suggest that hyperthyroidism alters the neurophysiology of food intake regulation. Increased SNS activity and reduced Trp precursor availability for 5-hydroxytryptamine synthesis in the brain may drive the marked hyperphagia and craving for carbohydrates that appears to characterize hyperthyroid patients. Because propranolol did not affect food intake in hyperthyroidism, the potential effect of catecholamines on food intake might be mediated by alpha-adrenoceptors.

Sympathovagal response to orthostatism in overt and in subclinical hyperthyroidism.

PubMed

Goichot, B; Brandenberger, G; Vinzio, S; Perrin, A E; Geny, B; Schlienger, J L; Simon, C

2004-04-01

Heart rate variability (HRV) is a measure of the physiological variation of R-R intervals, reflecting the sympathovagal balance. In both overt and subclinical hyperthyroidism, a relative increase in sympathetic activity has been demonstrated, mainly due to a decrease in vagal activity. The modifications of HRV during orthostatism in normal subjects resemble those seen in hyperthyroidism. We have studied the response of 19 patients with overt hyperthyroidism and 12 with subclinical hyperthyroidism during orthostatism using HRV and compared the results to those of 32 healthy controls. In the three groups, the R-R intervals decreased in the same proportion after orthostatism. The low frequency power (LF)/[LF + high frequency power (HF)] ratio, which reflects the sympathetic tone, also increased in the same proportion in the three groups. However, the mechanisms of the modulation of the sympathovagal balance during orthostatism were different among the three groups. In controls, the relative increase of sympathetic tone after orthostatism was due principally to a decrease in vagal tone (reflected by decreased power in the HF band), while in overt hyperthyroidism, where the power in the HF band was already minimal in the lying position, there was a clear increase in the LF band power during orthostatism. The results were intermediate in the subclinical hyperthyroidism group, reflecting a continuum of effects of the thyroid hormone excess on the autonomic nervous system. Our study shows that despite an apparent normal cardiovascular adaptation to orthostatism in hyperthyroidism, the modulation of the autonomic nervous system is profoundly modified.

Subclinical Nonautoimmune Hyperthyroidism in a Family Segregates with a Thyrotropin Receptor Mutation with Weakly Increased Constitutive Activity

PubMed Central

Chen, Chun-Rong; Higashiyama, Takuya; Mizutori-Sasai, Yumiko; Ito, Mitsuru; Kubota, Sumihisa; Amino, Nobuyuki; Miyauchi, Akira; Rapoport, Basil

2010-01-01

Background Subclinical hyperthyroidism is usually associated with Graves' disease or toxic nodular goiter. Here we report a family with hereditary subclinical hyperthyroidism caused by a constitutively activating germline mutation of the thyrotropin receptor (TSHR) gene. Methods The proband was a 64-year-old Japanese woman who presented with a thyroid nodule and was found to be euthyroid with a suppressed serum TSH. The nodule was not hot. Although antibodies to thyroid peroxidase and thyroglobulin antibodies were present, TSHR antibodies were not detected by TSH-binding inhibition or by bioassay. Two of her middle-aged sons, but not her daughter, also had subclinical hyperthyroidism without TSHR antibodies. Without therapy, the clinical condition of the affected individuals remained unchanged over 3 years without development of overt hyperthyroidism. Results A novel heterozygous TSHR point mutation causing a glutamic acid to lysine substitution at codon 575 (E575K) in the second extracellular loop was detected in the three family members with subclinical hyperthyroidism, but was absent in her one daughter with normal thyroid function. In vitro functional studies of the E575K TSHR mutation demonstrated a weak, but significant, increase in constitutive activation of the cAMP pathway. Conclusion Although hereditary nonautoimmune overt hyperthyroidism is very rare, TSHR activating mutations as a cause of subclinical hyperthyroidism may be more common and should be considered in the differential diagnosis, especially if familial. PMID:20929407

Short-Term Synaptic Plasticity Regulation in Solution-Gated Indium-Gallium-Zinc-Oxide Electric-Double-Layer Transistors.

PubMed

Wan, Chang Jin; Liu, Yang Hui; Zhu, Li Qiang; Feng, Ping; Shi, Yi; Wan, Qing

2016-04-20

In the biological nervous system, synaptic plasticity regulation is based on the modulation of ionic fluxes, and such regulation was regarded as the fundamental mechanism underlying memory and learning. Inspired by such biological strategies, indium-gallium-zinc-oxide (IGZO) electric-double-layer (EDL) transistors gated by aqueous solutions were proposed for synaptic behavior emulations. Short-term synaptic plasticity, such as paired-pulse facilitation, high-pass filtering, and orientation tuning, was experimentally emulated in these EDL transistors. Most importantly, we found that such short-term synaptic plasticity can be effectively regulated by alcohol (ethyl alcohol) and salt (potassium chloride) additives. Our results suggest that solution gated oxide-based EDL transistors could act as the platforms for short-term synaptic plasticity emulation.

Osteoporotic cytokines and bone metabolism on rats with induced hyperthyroidism; changes as a result of reversal to euthyroidism.

PubMed

Simsek, Gönül; Karter, Yesari; Aydin, Seval; Uzun, Hafize

2003-12-31

Hyperthyroidism is characterized by increased bone turnover and resorptive activity. Raised levels of serum osteoporotic cytokines, such as interleukin (IL) -1beta, IL-6 and tumor necrosis factor (TNF)-alpha have been demonstrated previously in hyperthyroidism. These elevations are controversial and it is difficult to differentiate the contribution of thyroid hormones to the elevation of cytokines from that of the autoimmune inflammation in Graves' disease (GD) and follicular cell damage in thyroiditis. Therefore, we investigated the effect of thyroid hormones on serum IL-1beta, IL-6, TNF-alpha levels and bone metabolism on L-thyroxine induced hyperthyroid rats and changes in cytokine levels and bone metabolism on the same rats after reversal to euthyroidism. Rats were treated with L-thyroxine for 5 weeks (0.4 mg/ 100 g food). Plasma T3, T4, TSH and serum IL-1beta, IL-6, TNFalpha, Calcium (Ca), phosphorous (P), parathyroid hormone (PTH), alkaline phosphatase (ALP), bone alkaline phosphatase (B-ALP) levels were measured and differential leucocyte counts were made initially, at the 5th week of the experiment (hyperthyroid state) and 5 weeks after quitting the administration of L-thyroxine (euthyroid state). Significant rises in serum IL-1beta, IL-6 and TNFalpha were noted in hyperthyroidism (P < 0.001). In euthyroid state, IL-15, IL-6 and TNFalpha decreased significantly, but IL-beta and TNFalpha were significantly higher than the baseline values (P < 0.05) while IL-6 levels turned back to the baseline values. Plasma T3 and T4 levels were significantly correlated with serum cytokines in hyperthyroid state while there was no correlation in euthyroid states. Ca and P levels did not differ significantly while PTH levels declined significantly in the hyperthyroid state (P < 0.05). After the reversal to the euthyroidism, there was no significant change in Ca, P and PTH levels. ALP and B-ALP increased significantly in hyperthyroidism (P < 0.001, P < 0.01) and they did not decrease in euthyroid state. The lymphocyte number and ratio in differentials increased significantly in the hyperthyroid state (P < 0.001). In euthyroidism they decreased significantly (P < 0.001) but it was significantly higher than the baseline value (P < 0.05). Our findings showed that the deleterious effect on bone metabolism in hyperthyroidism might be mediated by cytokines and the increased bone turnover in hyperthyroidism failed to decrease despite euthyroidism.

Best practice for the pharmacological management of hyperthyroid cats with antithyroid drugs.

PubMed

Daminet, S; Kooistra, H S; Fracassi, F; Graham, P A; Hibbert, A; Lloret, A; Mooney, C T; Neiger, R; Rosenberg, D; Syme, H M; Villard, I; Williams, G

2014-01-01

Pharmacological management of feline hyperthyroidism offers a practical treatment option for many hyperthyroid cats. Two drugs have been licensed for cats in the last decade: methimazole and its pro-drug carbimazole. On the basis of current evidence and available tablet sizes, starting doses of 2·5 mg methimazole twice a day and 10 to 15 mg once a day for the sustained release formulation of carbimazole are recommended. These doses should then be titrated to effect in order to obtain circulating total thyroxine (TT4) concentrations in the lower half of the reference interval. Treated cases should be monitored for side-effects, especially during the first months of treatment. Some side-effects may require discontinuation of treatment. At each monitoring visit, clinical condition and quality of life should also be evaluated, with special attention to possible development of azotaemia, hypertension and iatrogenic hypothyroidism. When euthyroidism has been achieved, monitoring visits are recommended after 1 month, 3 months and biannually thereafter. Cats with pre-existing azotaemia have shorter survival times. However, development of mild azotaemia during the initial course of treatment, unless associated with hypothyroidism, does not appear to decrease survival time. The long-term effects of chronic medical management require further study. © 2013 British Small Animal Veterinary Association.

131I therapy for 345 patients with refractory severe hyperthyroidism: Without antithyroid drug pretreatment

PubMed Central

Xing, Jialiu; Fang, Yi; Wang, Yong; Zhang, Youren; Long, Yahong

2015-01-01

The aim of this study is to evaluate the safety and long-term results of 131I therapy alone for patients with refractory severe hyperthyroidism without antithyroid drug pretreatment. From January 2002 to December 2012, 408 patients with refractory severe hyperthyroidism were treated with 131I alone. Among them, 345 were followed up for 1 to 10 years for physical examination, thyroid function, and thyroid ultrasound. Complete Blood Count (CBC) liver function, electrocardiogram, echocardiogram, and Emission Computed Tomography (ECT) thyroid imaging were performed as indicated. The 345 patients had concomitant conditions including thyrotoxic heart disease, severe liver dysfunction, enlarged thyroid weighing 80 to 400 g, severe cytopenia, and vasculitis. One to two weeks prior to 131I therapy, all patients were given low-iodine diet. The dose of 131I therapy was 2.59 to 6.66 MBq (70 to180 µCi) per gram of thyroid with an average of 3.83 ± 0.6 MBq (103.6 ± 16.4 µCi); and the total 131I activity administrated for the individuals was 111 to 3507.6 MBq (3.0 to 94.8 mCi, mean 444 ± 336.7 MBq (12.0 ± 9.1 mCi)). Out of the 408 patients, 283 were cured, 15 with complete remission, and 47 with incomplete remission. No treatment failure or significant clinical worsening was noted in these patients. Our data indicated that 131I therapy alone for patients with refractory severe hyperthyroidism without antithyroid drug pretreatment is safe and effective. PMID:26341470

RADIOACTIVE IODINE THERAPY WITHOUT RECENT ANTITHYROID DRUG PRETREATMENT FOR HYPERTHYROIDISM COMPLICATED BY SEVERE HYPERBILIRUBINEMIA DUE TO HEPATIC DYSFUNCTION: EXPERIENCE OF A CHINESE MEDICAL CENTER.

PubMed

Ding, Yong; Xing, Jialiu; Qiu, Zewu; Wang, Yong; Zhang, Youren; Fang, Yi; Peng, Xiaobo; Long, Yahong; Deng, Pei

2016-02-01

The objective of this work is to report our experience with (131)I therapy without recent antithyroid drug (ATD) pretreatment for refractory severe hyperthyroidism complicated by hyperbilirubinemia due to hepatic dysfunction. Five patients with refractory severe hyperthyroidism were treated with (131)I at 90 to 120 μCi/g-thyroid (total activity, 6.2 to 10.1 mCi). The patients previously had received ATD treatment from 2 months to 12 years and discontinued ATDs from 2 months to 4 years before (131)I treatment due to treatment failure or severe jaundice. Prior to (131)I therapy, the patients were asked to take a low-iodine diet and were treated with bisoprolol fumarate, digoxin, furosemide, S-adenosylmethionine, polyene phosphatidylcholine, and plasma exchange as supportive treatment for related clinical conditions. Four of the patients also received lithium carbonate in conjunction with their (131)I treatment. The patients were followed for 4 to 9 years after (131)I therapy. After (131)I treatment, jaundice disappeared completely within 3 to 4 months in all patients, and liver function tests returned to normal. Concurrent atrial fibrillation and heart failure, leukopenia and thrombocytopenia, or thrombocytopenia and left cardiac enlargement improved remarkably in 3 patients during the follow-up period. Three to 45 months after (131)I treatment, hypothyroidism was noted in the patients and they were treated with L-thyroxine replacement therapy. (131)I therapy without recent ATD pretreatment for refractory severe hyperthyroidism complicated by serious jaundice appears to be safe and effective, with good long-term results. It may be the preferred therapy for such patients and should be used as early as possible.

Hyperthyroidism causes mechanical insufficiency of myocardium with possibly increased SR Ca2+-ATPase activity.

PubMed

Takeuchi, Koh; Minakawa, M; Otaki, M; Odagiri, S; Itoh, K; Murakami, A; Yaku, H; Kitamura, N

2003-12-01

Hyperthyroidism is known to affect multiple organ functions, and thyroid hormone has been known to improve myocardial function in a failing heart. The purpose of this study is to elucidate the functional and metabolic effects of thyroid hormone on myocardium in a rat model exposed to long-term excess thyroid hormone, particularly focusing on the SR Ca(2+)-ATPase (SERCA2) function. 3,5,3'-Triiodo-L-thyronine (T3), or the vehicle, was subcutaneously given for 4 weeks (T3 and control [C] group). Bolus I.V. Thapsigargin (TG) was used to test the SERCA2 function (C-TG and T3-TG) in Langendorff perfused heart. Myocardial functions such as LV-developed pressure (LVDP; mmHg), +/- dP/dt (mmHg/s), tau (ms), and oxygen consumption (MVO(2); ml/min/g wt) were measured. SERCA2 and GLUT4 protein level were also evaluated by Western immunoblotting. Left ventricle to body weight (LV/BW) ratio was significantly higher in the T3 group. Both negative dP/dt and tau were significantly decreased by TG. It is interesting that the decrement of negative dP/dt and tau attained by TG was significantly larger in the hyperthyroid group (T3-TG) than in a normal heart (C-TG). SERCA2 and GLUT4 protein levels were not significantly different between control and the T3 group. We conclude that prolonged exposure to thyroid hormone causes hypertrophy of the myocardium and an augmentation of the SR Ca(2+) ATPase activity. Care must be taken in hyperthyroid heart during the ischemia-reperfusion process where the SRECA2 function is inhibited.

Triiodothyronine, beta-adrenergic receptors, agonist responses, and exercise capacity.

PubMed

Martin, W H

1993-07-01

Although thyroid hormone excess results in increased beta-adrenergic receptor density or agonist responses in some cells of experimental animals, the role of these effects in contributing to clinical manifestations of hyperthyroidism in human subjects is unclear. To shed further light on this issue, we characterized the effect of 2 weeks of excess triiodothyronine administration on cardiac and metabolic responses to graded-dose isoproterenol infusion, skeletal muscle beta-adrenergic receptor density, and physiologic determinants of exercise capacity in young healthy subjects. The slope of the heart rate response to isoproterenol was 36% greater (p < 0.05) after triiodothyronine administration. In addition, beta-adrenergic receptor density was increased (p < 0.01) in all types of skeletal muscle fibers. Maximal oxygen uptake during treadmill exercise declined 5% (p < 0.001) after triiodothyronine administration because of a decrease in the arteriovenous oxygen difference (p < 0.05). The plasma lactate response to submaximal exercise was 25% greater (p < 0.01) in the hyperthyroid state. These effects were paralleled by a decrement in skeletal muscle oxidative capacity and a decrease in cross-sectional area of type 2A skeletal myocytes. Thus, thyroid hormone excess enhances cardiac beta-adrenergic sensitivity under in vivo conditions in human subjects. Nevertheless, exercise capacity is diminished in the hyperthyroid state, an effect that may be related to reduced skeletal muscle oxidative capacity and type 2A fiber atrophy.

Redox regulation of myocardial ERK 1/2 phosphorylation in experimental hyperthyroidism: role of thioredoxin-peroxiredoxin system.

PubMed

Araujo, Alex Sander da Rosa; Fernandes, Tania; Ribeiro, Maria Flavia; Khaper, Neelam; Belló-Klein, Adriane

2010-11-01

The present study was conducted to test whether adaptation in the antioxidant system would differentially modulate prosurvival and proapoptotic proteins in hyperthyroidism-induced cardiac hypertrophy. Male Wistar rats were divided into 4 groups: control, vitamin E (20 mg · kg(-1) · d(-1) subcutaneously, 28 days), thyroxine (T4) (12 mg/L in drinking water for 28 days), and T4 + vitamin E. Cardiac mass, redox ratio, glutathione peroxidase (GPx) and glutathione reductase (GR) activities, NF-E2-related factor 2 (Nrf2) thioredoxin-1 (Trx-1), peroxiredoxin-6 (Prx-6), phospho-extracellular-signal-regulated kinases 1/2 (p-ERK 1/2)/extracellular-signal-regulated kinases 1/2 (ERK1/2), and phospho-c-Jun N-terminal kinase (p-JNK)/c-Jun N-terminal kinase (JNK) myocardial protein expression were quantified. Cardiac hypertrophy was attenuated in the T4 + vitamin E group. The redox ratio; GPx and GR; as well as Nrf2, Trx-1, Prx-6, and p-ERK1/2/ERK1/2 immunocontent were elevated in T4 group. All these effects were attenuated by vitamin E administration. p-JNK/JNK remained unchanged in all the groups. The overall results suggest that redox imbalance due to hyperthyroidism induce adaptation of antioxidant systems, favoring ERK1/2 activation and leading to development of cardiac hypertrophy.

Weight loss and severe jaundice in a patient with hyperthyroidism.

PubMed

Breidert, M; Offensperger, S; Blum, H E; Fischer, R

2011-09-01

Thyrotoxicosis may significantly alter hepatic function and is associated with autoimmune disorders of the liver. We report the case of a thyrotoxic patient with Graves' disease and histologically established cholestatic hepatitis. Medical treatment of hyperthyroidism normalized liver function tests. In patients with elevated liver function parameters and jaundice of unknown origin, thyroid function should generally be tested. Moreover, medical treatment of hyperthyroidism with thyrostatics may cause severe hepatitis whereas untreated hyperthyroid patients are at risk of developing chronic liver failure. © Georg Thieme Verlag KG Stuttgart · New York.

Hyperthyroidism presenting as isolated tricuspid regurgitation and right heart failure.

PubMed

Whitner, Tanya E; Hudson, Christopher J; Smith, Timothy D; Littmann, Laszlo

2005-01-01

Although hyperthyroidism has many signs and symptoms, right heart failure can occasionally be the main presenting symptom. We describe the case of a previously healthy 42-year-old woman whose chief complaint was progressive bilateral lower extremity edema. The echocardiogram revealed right atrial dilatation and moderate-to-severe tricuspid regurgitation. Results of laboratory studies were consistent with hyperthyroidism. Thyroid ablation resulted in permanent resolution of symptoms and resolution of tricuspid incompetence on echocardiography. In a case of isolated, unexplained tricuspid regurgitation, it is important to consider indolent hyperthyroidism in the differential diagnosis.

[Children with hyperthyroidism due to elevated hCG levels].

PubMed

Jöbsis, Jasper J; van Trotsenburg, A S Paul; Merks, Johannes H M; Kamp, Gerdine A

2014-01-01

We describe two children with hyperthyroidism secondary to elevated hCG levels: one patient with gestational trophoblastic disease and one patient with choriocarcinoma. hCG resembles other glycoproteins that can lead to hyperthyroidism through TSH receptor activation. Also, through its LH-mimicking effect, hCG can induce high oestradiol levels, resulting in stormy pubertal development. False negative hCG tests due to the high-dose hook effect may complicate the diagnostic process. In patients with antibody-negative thyrotoxicosis, the diagnosis of hCG-induced hyperthyroidism must be considered.

Painless thyroiditis complicating with hypercalcemic encephalopathy.

PubMed

Thewjitcharoen, Yotsapon; Lumlertgul, Nuttha

2012-01-01

Severe hypercalcemia has rarely been reported in patients with hyperthyroidism. Although the pathogenesis is not clear; it is believed to be due to activation of osteoclasts resulting in excessive bone resorption. To recognize the unusual cause of hypercalcemia from painless thyroiditis, which could manifest with transient hyperthyroidism in the early stage. A 70-year-old woman presented with watery diarrhea, nausea and vomiting and significant weight loss for two months. Initially, she was misdiagnosed as having Graves'disease from her clinical presentation and thyroid function tests. Oral propylthiouracil was given to treat hyperthyroidism. However two weeks after discharge, she developed altered consciousness due to severe hypercalcemia. After combined treatment of hypercalcemia and severe hyperthyroidism, her symptoms resolved quickly. Later on, her thyroid function tests switched to subclinical hypothyroid at two months after initial presentation. No concurrent pathological conditions could be found to explain the other causes of hypercalcemia. Therefore, painless thyroiditis complicated with severe hypercalcemia was subsequently diagnosed based on her clinical course. Hypercalcemic encephalopathy is an uncommon manifestation of hyperthyroidism that should be kept in mind in patients who demonstrated clinical pictures of hyperthyroidism and alteration of consciousness. Moreover the present case emphasizes the consideration of painless thyroiditis as a differential diagnosis of hyperthyroidism because anti-thyroid medications were not indicated in this condition.

Galanin does not affect the growth hormone-releasing hormone-stimulated growth hormone secretion in patients with hyperthyroidism.

PubMed

Giustina, A; Bussi, A R; Legati, F; Bossoni, S; Licini, M; Schettino, M; Zuccato, F; Wehrenberg, W B

1992-12-01

Patients with hyperthyroidism have reduced spontaneous and stimulated growth hormone (GH) secretion. The aim of our study was to evaluate the effects of galanin, a novel neuropeptide which stimulates GH secretion in man, on the GH response to GHRH in patients with hyperthyroidism. Eight untreated hyperthyroid patients with Graves' disease (6F, 2M, aged 25-50 years) and six healthy volunteers (3F, 3M, aged 27-76 years) underwent from -10 to 30 min in random order: (i) porcine galanin, iv, 500 micrograms in 100 ml saline; or (ii) saline, iv, 100 ml. A bolus of human GHRH(1-29)NH2, 100 micrograms, was injected iv at 0 min. Hyperthyroid patients showed blunted GH peaks after GHRH+saline (10.2 +/- 2.5 micrograms/l) compared to normal subjects (20.7 +/- 4.8 micrograms/l, p < 0.05). GH peaks after GHRH+galanin were also significantly lower in hyperthyroid subjects (12.5 +/- 3 micrograms/l) compared to normal subjects (43.8 +/- 6 micrograms/l, p < 0.05). That galanin is not able to reverse the blunted GH response to GHRH in hyperthyroidism suggests that hyperthyroxinemia may either increase the somatostatin release by the hypothalamus or directly affect the pituitary GH secretory capacity.

Hyperthyroidism (primary)

PubMed Central

2008-01-01

Introduction Hyperthyroidism is characterised by high levels of serum thyroxine and triiodothyronine, and low levels of thyroid-stimulating hormone. The main causes of hyperthyroidism are Graves' disease, toxic multinodular goitre, and toxic adenoma. About 20 times more women than men have hyperthyroidism. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments for primary hyperthyroidism? What are the effects of surgical treatments for primary hyperthyroidism? What are the effects of treatments for subclinical hyperthyroidism? We searched: Medline, Embase, The Cochrane Library and other important databases up to June 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 14 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: adding thyroxine to antithyroid drugs (carbimazole, propylthiouracil, and thiamazole), antithyroid drugs (carbimazole, propylthiouracil, and thiamazole), radioactive iodine, and thyroidectomy. PMID:19450325

Hyperthyroidism in cats: what's causing this epidemic of thyroid disease and can we prevent it?

PubMed

Peterson, Mark

2012-11-01

Since first being reported in the late 1970s, there has been a dramatic increase in the prevalence of hyperthyroidism in cats. It is now recognized worldwide as the most common feline endocrine disorder. Hyperthyroidism is an important cause of morbidity in cats older than 10 years of age. It is estimated that over 10% of all senior cats will develop the disorder. Despite its frequency, the underlying cause(s) of this common disease is/are not known, and no one has suggested a means to prevent the disorder. Because of the multiple risk factors that have been described for feline hyperthyroidism, it is likely that more than one factor is involved in its pathogenesis. Continuous, lifelong exposure to environmental thyroid disruptor chemicals or goitrogens in food or water, acting together in an additive or synergistic manner, may first lead to euthyroid goiter and then to autonomous adenomatous hyperplasia, thyroid adenoma and hyperthyroidism. This review draws on published research studies to summarize the available evidence about the risk factors for feline hyperthyroidism. Based on the known goitrogens that may be present in the cat's food, drinking water or environment, it proposes measures that cat owners can implement that might prevent, or reduce the prevalence of, thyroid tumors and hyperthyroidism in their cats.

Interventions for preventing and treating hyperthyroidism in pregnancy

PubMed Central

Earl, Rachel; Crowther, Caroline A; Middleton, Philippa

2014-01-01

Background Women with hyperthyroidism in pregnancy have increased risks of miscarriage, stillbirth, preterm birth, and intrauterine growth restriction; and they can develop severe pre-eclampsia or placental abruption. Objectives To assess the effects of interventions for preventing or treating hyperthyroidism in pregnant women. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (28 July 2010). Selection criteria We intended to include randomised controlled trials comparing antithyroid treatments in pregnant women with hyperthyroidism. Data collection and analysis Two review authors would have assessed trial eligibility and risk of bias, and extracted data. Main results No trials were located. Authors’ conclusions As we did not identify any eligible trials, we are unable to comment on implications for practice, although early identification of hyperthyroidism before pregnancy may allow a woman to choose radioactive iodine therapy or surgery before planning to have a child. Designing and conducting a trial of antithyroid drugs for pregnant women with hyperthyroidism presents formidable challenges. Not only is hyperthyroidism a relatively rare condition, both of the two main drugs used have potential for harm, one for the mother and the other for the child. More observational research is required about the potential harms of methimazole in early pregnancy and about the potential liver damage from propylthiouracil. PMID:20824882

Hyperthyroidism is a Risk Factor for Developing Adhesive Capsulitis of the Shoulder: A Nationwide Longitudinal Population-Based Study

PubMed Central

Huang, Shih-Wei; Lin, Jia-Wei; Wang, Wei-Te; Wu, Chin-Wen; Liou, Tsan-Hon; Lin, Hui-Wen

2014-01-01

The purpose of this study was to investigate the prevalence and risk of adhesive capsulitis among hyperthyroidism patients. The data were obtained from the Longitudinal Health Insurance Database 2005 (LHID 2005) in Taiwan, using 1 million participants and a prospective population-based 7-year cohort study of survival analysis. The ambulatory-care claim records of patients diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes relating to hyperthyroidism between January 1, 2004 and December 31, 2007, were obtained. The prevalence and the adjusted hazard ratio (HR) of adhesive capsulitis among hyperthyroid patients and the control group were estimated. Of 4472 hyperthyroid patients, 162 (671/100 000 person-years) experienced adhesive capsulitis during the 24 122 person-year follow-up period. The crude HR of stroke was 1.26 (95% confidence interval [CI], 1.06 to 1.49), which was larger than that of the control group. The adjusted HR of developing adhesive capsulitis was 1.22 (95% CI, 1.03 to 1.45) for hyperthyroid patients during the 7-year follow-up period, which achieved statistical significance. The results of our large-scale longitudinal population-based study indicated that hyperthyroidism is an independent risk factor of developing adhesive capsulitis. PMID:24567049

Hyperthyroidism is a risk factor for developing adhesive capsulitis of the shoulder: a nationwide longitudinal population-based study.

PubMed

Huang, Shih-Wei; Lin, Jia-Wei; Wang, Wei-Te; Wu, Chin-Wen; Liou, Tsan-Hon; Lin, Hui-Wen

2014-02-25

The purpose of this study was to investigate the prevalence and risk of adhesive capsulitis among hyperthyroidism patients. The data were obtained from the Longitudinal Health Insurance Database 2005 (LHID 2005) in Taiwan, using 1 million participants and a prospective population-based 7-year cohort study of survival analysis. The ambulatory-care claim records of patients diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes relating to hyperthyroidism between January 1, 2004 and December 31, 2007, were obtained. The prevalence and the adjusted hazard ratio (HR) of adhesive capsulitis among hyperthyroid patients and the control group were estimated. Of 4472 hyperthyroid patients, 162 (671/100,000 person-years) experienced adhesive capsulitis during the 24,122 person-year follow-up period. The crude HR of stroke was 1.26 (95% confidence interval [CI], 1.06 to 1.49), which was larger than that of the control group. The adjusted HR of developing adhesive capsulitis was 1.22 (95% CI, 1.03 to 1.45) for hyperthyroid patients during the 7-year follow-up period, which achieved statistical significance. The results of our large-scale longitudinal population-based study indicated that hyperthyroidism is an independent risk factor of developing adhesive capsulitis.

Hyperthyroidism (primary)

PubMed Central

2010-01-01

Introduction Hyperthyroidism is characterised by high levels of serum thyroxine and triiodothyronine, and low levels of thyroid-stimulating hormone. The main causes of hyperthyroidism are Graves' disease, toxic multinodular goitre, and toxic adenoma. About 20 times more women than men have hyperthyroidism. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments for primary hyperthyroidism? What are the effects of surgical treatments for primary hyperthyroidism? What are the effects of treatments for subclinical hyperthyroidism? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 15 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: adding thyroxine to antithyroid drugs (carbimazole, propylthiouracil, and thiamazole), antithyroid drugs (carbimazole, propylthiouracil, and thiamazole), radioactive iodine, and thyroidectomy. PMID:21418670

Activity of the hypothalamo-pituitary axis and testicular development in prepubertal ram lambs with induced hypothyroidism or hyperthyroidism.

PubMed

Chandrasekhar, Y; D'Occhio, M J; Holland, M K; Setchell, B P

1985-10-01

Prepubertal (16 weeks old) ram lambs were used to investigate the effects of hyperthyroidism and hypothyroidism on development of reproductive endocrine function. Over a period of 8 weeks, ram lambs were made hypothyroid (serum T4 less than or equal to 3 ng/ml compared with controls congruent to 30 ng/ml) by daily oral administration of methyl thiouracil or hyperthyroid (serum T4 congruent to 135 ng/ml) by daily sc injection of T4. Hyperthyroidism was associated with decreases in LH pulse frequency (2.25 +/- 0.75/12 h compared with controls 5.75 +/- 0.48/12 h), basal LH, and mean LH concentrations, together with arrested testicular growth and aspermatogenesis. Hypothyroid rams showed normal pubertal development. After iv injection of LHRH, hyperthyroid ram lambs showed similar LH responses to control and hypothyroid rams. Basal testosterone production (5.6 +/- 1.0 ng/min) and plasma testosterone concentrations after human CG (2.0 +/- 0.7 ng/ml) in hyperthyroid rams were significantly lower than in controls (67.5 +/- 24.0 ng/min and 5.2 +/- 1.0 ng/ml, respectively). It is concluded that retarded testicular development in hyperthyroid ram lambs results from changes in hypothalamo-pituitary activity manifested in a decreased LH pulse frequency.

[Surgical Diagnosis and Treatment of Primary Hyperthyroidism Complicated with Occult Thyroid Carcinoma].

PubMed

Wu, Xin; Yu, Jian-chun; Kang, Wei-ming; Ma, Zhi-qiang; Ye, Xin

2015-08-01

To evaluate the surgical diagnosis and treatment of primary hyperthyroidism complicated with occult thyroid carcinoma. Data of 51 cases of primary hyperthyroidism complicated with occult thyroid carcinoma admitted during January 2004 to November 2014 were analyzed retrospectively. The incidence of occult thyroid carcinoma was 5.03% in hyperthyroidism,and 47 cases (92.16%) were female. The preoperative diagnosis of all these 51 cases was primary hyperthyroidism and 11 cases were diagnosed thyroid carcinoma at the same time;25 cases were diagnosed thyroid carcinoma by frozen section and the remaining 26 cases were diagnosed by postoperative pathology. Finally,26 cases underwent subtotal thyroidectomy,4 cases underwent total thyroidectomy, and 21 cases underwent total thyroidectomy with lymphadenectomy. The tumor size ranged from 0.1 to 1.0 cm [mean:(0.63 ± 0.35) cm]. The lesions were less than or equal to 0.5 cm in 28 cases (54.9%). The follow-up lasted from 1 to 121 months [mean:(28.6 ± 22.7)months] in 43 patients,and all of them survived. Primary hyperthyroidism complicated with occult thyroid carcinoma is commonly found in female patients. Preoperative diagnosis is difficult. Ultrasound is the major examining method. Frozen section can increase the detection rate. The postoperative prognosis of hyperthyroidism complicated with occult thyroid carcinoma is satisfactory.

Elevated levels of circulating thyroid hormone do not cause the medical sequelae of hyperthyroidism.

PubMed

Kelly, Tammas; Denmark, Lawrence; Lieberman, Daniel Z

2016-11-03

Clinicians have been reluctant to use high dose thyroid (HDT) to treat affective disorders because high circulating levels of thyroid hormone have traditionally been equated with hyperthyroidism, and understood as the cause of the medical sequelae of hyperthyroidism, such as osteoporosis and cardiac abnormalities. This conclusion is not supported by (HDT) research. A literature review of research related to the morbidity and mortality of HDT treatment was performed. There exists a large body of research involving the use of HDT treatment to prevent the recurrence of differentiated thyroid cancer and to treat affective disorders. A review of this literature finds a lack of support for HDT as a cause of osteoporosis, nor is there support for an increase in morbidity or mortality associated with HDT. This finding contrasts with the well-established morbidity and mortality associated with Graves' disease, thyroiditis, and other endogenous forms of hyperthyroidism. The lack of evidence that exogenous HDT causes osteoporosis, cardiac abnormalities or increases mortality compared with the significant morbidity and mortality of hyperthyroidism requires an alternative cause for the medical sequelae of hyperthyroidism. One possibility is an autoimmune mechanism. High circulating levels of thyroid hormone is not the cause of the sequela of hyperthyroidism. The reluctance to using high dose thyroid is unwarranted. Copyright © 2016 Elsevier Inc. All rights reserved.

Levels of plasma fibrinogen and D-dimer in subjects with subclinical hyperthyroidism.

PubMed

Coban, Erkan; Aydemir, Mustafa

2008-01-01

During the last 15 years, several risk markers for atherosclerosis, such as fibrinogen and D-dimer, have been identified. The role of elevated fibrinogen levels as an independent risk factor for coronary, cerebral, and peripheral vascular disease is well established on the basis of clinical and epidemiological studies. Increased D-dimer levels are associated with increased risk of future myocardial infarction, stroke, and peripheral vascular disease. The aim of this study was to evaluate the alterations in fibrinogen and D-dimer, which indicates overall thrombotic activity, in subjects with subclinical hyperthyroidism. Thirty-six subclinical hyperthyroidic subjects and 36 euthyroidic control subjects matched for age, gender, and body mass index were selected. The levels of plasma fibrinogen and D-dimer in all subjects were measured. The level of fibrinogen was significantly higher in the subclinical hyperthyroidic group than in the euthyroidic group (296.9+/-74.3 mg/dl vs. 255.0+/-41.7 mg/dl, p<0.001). The level of D-dimer was significantly higher in the subclinical hyperthyroidic group than in the euthyroidic group (261.9+/-47.8 mg/dl vs. 216.4+/-32.1 mg/dl, p<0.000). The results suggest that subjects with subclinical hyperthyroidism present a relatively hypercoagulable state. This state could contribute to increased thromboembolic risk in subclinical hyperthyroidism.

Neurological and psychiatric disorders in thyroid dysfunctions. The role of nuclear medicine: SPECT and PET imaging.

PubMed

Lass, P; Slawek, J; Derejko, M; Rubello, D

2008-06-01

Thyroid dysfunctions may be accompanied by numerous neurological and psychiatric disorders. The most known is cognitive impairment and depression in hypothyroid patients, as well as an increased risk of cerebrovascular accidents. A separate, although a rare entity, is Hashimoto's encephalopathy. In hyperthyroidism there is an increased incidence of psychiatric disorders, including apathetic hyperthyroidism and hyperthyroid dementia. Functional imaging of cerebral blood flow and metabolism helped establish both global and/or regional decrease of both cerebral blood flow and metabolism in hypothyroidism, particularly in regions mediating attention, motor speed and visuospatial processing. Hypothyroid dementia may be mediated by neurocircuitry different from that in major depression. Less is known on flow/metabolism changes in hyperthyroidism. Global blood flow may be slightly increased, with regional deficits of blood flow, particular in hyperthyroid dementia. As presented above radionuclide functional imaging showed some metabolic patterns in thyroid dysfunctions, but still many issues remain unresolved. In particular little is known about the underlying pathology of cognitive impairment and depression in hypothyroidism, which may differ from ones in euthyroid patients. Also little is known about the reversibility of changes in cerebral blood flow following thyroid replacement therapy. In hyperthyroid patients functional imaging might contribute to elucidate the background of apathetic hyperthyroidism and potential different background of psychiatric complications.

Negative correlation between bone mineral density and TSH receptor antibodies in long-term euthyroid postmenopausal women with treated Graves’ disease

PubMed Central

2013-01-01

Background Thyrotoxicosis is a cause of secondary osteoporosis. High concentrations of triiodotironine (T3) in Graves’ disease stimulate bone turnover, but it is unclear if euthyroidism will always normalize bone metabolism. Thyrotropin (TSH) is known to affect directly the bone metabolism through the TSH receptor and TSH receptor antibodies (TRAb) may have an important role in bone turn-over. The aim of our study was to determine, in pre and postmenopausal euthyroidism patients with previous overt hyperthyroidism due to Graves’ disease the bone mineral density (BMD) as well as factors that could affect BMD in each group, including TRAb. Methods Cross-sectional, non-interventional study. Fifty-seven patients with previous hyperthyroidism due to Graves’ disease (premenopausal: 30, postmenopausal: 27) that remained euthyroid for at least 6 months prior to study were included and compared with fifty- two matched respective controls. Thyrotoxine (T4), TSH, TRAb and BMD were measured. Results Only euthyroid postmenopausal patients with a history of hyperthyroidism due to Graves’ disease showed lower whole body BMD than matched controls. The BMD expressed as Z-score was less in whole body and lumbar spine in postmenopausal in relation to premenopausal women with previous overt hyperthyroidism due to Graves’ disease. In the postmenopausal patients, the Z-score of lumbar spine BMD correlated negatively with TRAb (r = −0,53, p < 0.008), positively with the time of evolution of the disease (r = +0.42, p < 0.032) and positively with the time of euthyroidism (r = + 0.50, p < 0.008), but neither with serum T4 nor TSH. In a multiple regression analysis TRAb was the only significant independent variable in relation to lumbar spine BMD (F = 3. 90, p < 0.01). Conclusions In euthyroid women with a history of Graves’ hyperthyroidism, BMD was only affected in the postmenopausal group. The negative correlation of Z-score of lumbar spine BMD with TRAb suggests that this antibody may affect the bone metabolism. PMID:24020400

76 FR 28788 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-18

... studies have been quasi-experimental designs focused on short term workload assessments as outcomes. The... experimental research to define further the effectiveness and cost-benefit of MSD control interventions. A... prospective experimental design (multiple baselines across groups with randomization). These interventions...

The Short-Term and Maintenance Effects of Self-Regulated Strategy Development in Writing for Middle School Students

ERIC Educational Resources Information Center

Hacker, Douglas J.; Dole, Janice A.; Ferguson, Monica; Adamson, Sharon; Roundy, Linda; Scarpulla, Laura

2015-01-01

Our purpose for this quasi-experimental study was to evaluate the short-term and maintenance effects of the self-regulated strategy development writing instructional model by Graham and Harris with 7th-grade students in an urban, ethnically diverse Title I middle school. We compared the writing skills of our intervention students with those of…

Induced Versus Spontaneous Rehearsal in Short-Term Memory in Nursery School Children. Study M: Development of Selective Attention Abilities.

ERIC Educational Resources Information Center

Kingsley, Phillip R.; Hagen, John W.

Eighty nursery school children were randomly divided into four groups of 20 and given a serial short-term memory task in which difficult-to-label stimuli were used. Three experimental groups were provided with labels for the stimuli. Of these, one group overtly pronounced the labels and rehearsed them during the task, one group merely pronounced…

Cardiovascular morbidity and mortality after treatment of hyperthyroidism with either radioactive iodine or thyroidectomy.

PubMed

Ryodi, Essi; Metso, Saara; Huhtala, Heini; Välimäki, Matti; Auvinen, Anssi; Jaatinen, Pia

2018-06-08

BACKGROUND Hyperthyroid patients remain at an increased risk of cardiovascular diseases (CVDs) after restoring euthyroidism. The impact of the different treatment modalities of hyperthyroidism on future CVD risk remains unclear. The aim of this paper is to assess cardiovascular morbidity and mortality in hyperthyroidism before and after the treatment, and to compare the effects of two different treatment modalities, radioactive iodine (RAI) and thyroid surgery. METHODS A comparative cohort study was conducted among 6,148 hyperthyroid patients treated either with RAI or thyroidectomy, and 18,432 age- and gender-matched controls. Firstly, hospitalizations due to CVDs prior to the treatment were analyzed. Secondly, the hazard ratios (HR) for any new hospitalization and mortality due to CVDs after the treatment were estimated among all the hyperthyroid patients compared to the age- and gender-matched controls and also in the RAI-treated patients compared to the thyroidectomy-treated patients. The results were adjusted for prevalent CVDs at the time of treatment. RESULTS Before the treatment of hyperthyroidism, hospitalizations due to all CVDs were more common in the hyperthyroid patients compared to the controls (OR 1.61, 95% CI 1.49-1.73). During the post-treatment follow-up, hospitalizations due to CVDs remained more frequent among the patients (HR 1.15, 95% CI 1.09-1.21), but there was no difference in CVD mortality (HR 0.93, 95% CI 0.84-1.03). Compared to the patients treated with thyroidectomy, the RAI-treated patients had a higher risk of hospitalization due to all CVDs (HR 1.17), and atrial fibrillation (HR 1.28), as well as a higher CVD mortality (HR 2.56). Yet, treatment with RAI resulting in hypothyroidism was not associated with increased CVD morbidity compared with thyroidectomy. CONCLUSIONS Hyperthyroidism increases the risk of CVD-related hospitalization, and the risk is sustained for up to two decades after treatment with RAI or surgery. Hyperthyroid patients treated with RAI remain at a higher CVD risk compared to patients treated with thyroidectomy. Hypothyroidism during the follow-up, however, predicts better cardiovascular outcome.

Prevalence of and risk factors for feline hyperthyroidism in South Africa.

PubMed

McLean, Joanne L; Lobetti, Remo G; Mooney, Carmel T; Thompson, Peter N; Schoeman, Johan P

2017-10-01

Objectives Hyperthyroidism is a disorder of older cats that may have a geographical variation in prevalence. Prevalence studies have not yet been performed in South Africa, a geographical area where hyperthyroidism in cats has recently been observed and where, reportedly, the incidence appears to be increasing. The purpose of this study was to determine the prevalence of feline hyperthyroidism in South Africa and to identify any potential risk factors. Further information on the worldwide prevalence and possible causative factors would increase our understanding of the aetiology of this disease and help identify any preventive measures. Methods Serum total thyroxine (tT4) and canine thyroid-stimulating hormone (cTSH) were measured in 302 cats aged 9 years and older that were presented at various veterinary clinics throughout South Africa. In cats with equivocal tT4 and undetectable cTSH values, serum free thyroxine (fT4) was also measured. At the time of blood sampling a questionnaire was completed regarding vaccination history, internal and external parasite control, diet and environment. Results Prevalence of hyperthyroidism (tT4 >50 nmol/l or tT4 between 30 and 50 nmol/l with TSH <0.03 ng/ml and fT4 >50 pmol/l) was 7% (95% confidence interval 4.4-10.4), with no significant difference between healthy (5%) and sick (8%) cats. Cats ⩾12 years of age (odds ratio [OR] 4.3, P = 0.02) and cats eating canned food (OR 2.1, P = 0.1) were more likely to be diagnosed with hyperthyroidism. No significant relationship between vaccinations, parasite control or indoor environment and hyperthyroidism was observed. Hyperthyroid cats were more likely to present with weight loss (OR 3.2, P = 0.01) and with a heart rate ⩾200 beats per min (OR 5, P = 0.01) than cats without the disease. Conclusions and relevance Hyperthyroidism does not appear to be uncommon in the South African cat population. Risk factors for hyperthyroidism, specifically older age and eating canned food, were present in this as in other reported populations.

Association of iatrogenic hypothyroidism with azotemia and reduced survival time in cats treated for hyperthyroidism.

PubMed

Williams, T L; Elliott, J; Syme, H M

2010-01-01

Iatrogenic hypothyroidism can occur after treatment of hyperthyroidism, and is correlated with a reduced glomerular filtration rate in humans and dogs. Cats with iatrogenic hypothyroidism after treatment for hyperthyroidism will have a greater incidence of azotemia than euthyroid cats. Eighty client owned cats with hyperthyroidism. Two retrospective studies. (1) Longitudinal study of 12 hyperthyroid cats treated with radioiodine (documented as euthyroid after treatment), to assess changes in plasma thyroid stimulating hormone (TSH) concentration over a 6-month follow-up period, (2) Cross-sectional study of 75 hyperthyroid cats (documented as euthyroid) 6 months after commencement of treatment for hyperthyroidism to identify the relationship between thyroid status and the development of azotemia. Kaplan-Meier survival analysis was performed to identify relationships between thyroid and renal status and survival. Plasma TSH concentrations were not suppressed in 7 of 8 cats with hypothyroidism 3 months after radioiodine treatment. The proportion of cats with azotemia was significantly (P= .028) greater in the hypothyroid (16 of 28) than the euthyroid group (14 of 47). Twenty-eight of 41 cats (68%) with plasma TT4 concentration below the laboratory reference range had an increased plasma TSH concentration. Hypothyroid cats that developed azotemia within the follow-up period had significantly (P= .018) shorter survival times (median survival time 456 days, range 231-1589 days) than those that remained nonazotemic (median survival time 905 days, range 316-1869 days). Iatrogenic hypothyroidism appears to contribute to the development of azotemia after treatment of hyperthyroidism, and reduced survival time in azotemic cats. Copyright © 2010 by the American College of Veterinary Internal Medicine.

Increase in incidence of hyperthyroidism predominantly occurs in young people after iodine fortification of salt in Denmark.

PubMed

Bülow Pedersen, Inge; Laurberg, Peter; Knudsen, Nils; Jørgensen, Torben; Perrild, Hans; Ovesen, Lars; Rasmussen, Lone Banke

2006-10-01

To prevent goiter and nodular hyperthyroidism, iodine fortification (IF) of salt was introduced in Denmark in 1998. We prospectively registered all new cases of overt hyperthyroidism in two areas of Denmark before and for the first 6 yr after iodine fortification. We used a computer-based register of all new cases of hyperthyroidism in two population subcohorts with moderate iodine deficiency (Aalborg, n = 310,124) and mild iodine deficiency (Copenhagen, n = 225,707), respectively. Data were obtained 1) before IF (1997-1998); 2) during voluntary IF (1999-2000); 3) during the early (2001-2002) period of mandatory IF; and 4) during the late (2003-2004) period with mandatory IF. The overall incidence rate of hyperthyroidism increased [baseline, 102.8/100,000/year; voluntary IF, 122.8; early mandatory IF, 140.7; late mandatory IF, 138.7 (P for trend <0.001)]. Hyperthyroidism increased in both sexes (P < 0.001) and in all age groups: 0-19, 20-39, 40-59, and 60+ yr (P for trend <0.001). The increase was relatively highest in young adults aged 20-39 yr: late mandatory IF (percent increase from baseline), age 20-39, 160%, P < 0.001; age 40-59, 29%, P < 0.01; age 60+ yr, 13%, P = not significant. Even a cautious iodization of salt results in an increase in the incidence rate of hyperthyroidism. Contrary to current concepts, many of the new cases were observed in young subjects, and are presumably of autoimmune origin. Furthermore, monitoring is expected to show a decrease in the number of elderly subjects suffering from nodular hyperthyroidism.

Treatment of paediatric hyperthyroidism but not hypothyroidism has a significant effect on weight.

PubMed

Crocker, Melissa K; Kaplowitz, Paul

2010-12-01

Thyroid hormones are involved in metabolic regulation, but the degree to which they affect body weight and body mass index (BMI) in children is unclear. We examined the effect of hypo- and hyperthyroidism on weight and BMI at the time of diagnosis and after appropriate treatment. Prospective and retrospective case series. Children referred for thyroid dysfunction were enrolled prospectively if their total or free T4 was elevated with TSH <0·05 mIU/ml (N = 57) or if they had a subnormal total or free T4 and TSH >20 (N = 29). Almost all patients had at least 2 classic signs or symptoms including goitre, but hyperthyroid patients had more symptoms. Mean BMI z scores at the time of diagnosis did not significantly differ between the two groups. Males with hyperthyroidism complained of weight loss more frequently and had a lower pretreatment BMI z score than hyperthyroid females. Hypothyroid patients lost a minimal amount of weight by the first follow-up (mean of 0·3 kg) and on average gained weight by the second follow-up visit. In contrast hyperthyroid patients gained a mean of 3·4 kg at the first follow-up visit and a mean of 7·1 kg by the second. Correction of hypothyroidism resulted in minimal weight loss, suggesting that hypothyroidism does not cause significant weight gain in children. In contrast, correction of the hyperthyroid state had a somewhat greater impact on weight status. These results are consistent with prior reports but surprising given the opposite metabolic effects of hypo- and hyperthyroidism. © 2010 Blackwell Publishing Ltd.

Treatment of pediatric hyperthyroidism but not hypothyroidism has a significant effect on weight

PubMed Central

Crocker, Melissa K.; Kaplowitz, Paul

2010-01-01

Objective Thyroid hormones are involved in metabolic regulation, but the degree to which they affect body weight and body mass index (BMI) in children is unclear. We examined the effect of hypo- and hyperthyroidism on weight and BMI at the time of diagnosis and after appropriate treatment. Design Prospective and retrospective case series Patients Children referred for thyroid dysfunction were enrolled prospectively if their total or free T4 was elevated with TSH <0.05 mIU/mL (N=57) or if they had a subnormal total or free T4 and TSH >20 (N=29). Results Almost all patients had at least 2 classic signs or symptoms including goiter, but hyperthyroid patients had more symptoms. Mean BMI z scores at the time of diagnosis did not significantly differ between the two groups. Males with hyperthyroidism complained of weight loss more frequently and had a lower pretreatment BMI z score than hyperthyroid females. Hypothyroid patients lost a minimal amount of weight by the first follow-up (mean of 0.3 kilograms (kg)) and on average gained weight by the second follow-up visit. In contrast hyperthyroid patients gained a mean of 3.4 kg at the first follow-up visit and a mean of 7.1 kg by the second. Conclusions Correction of hypothyroidism resulted in minimal weight loss, suggesting that hypothyroidism does not cause significant weight gain in children. In contrast, correction of the hyperthyroid state had a somewhat greater impact on weight status. These results are consistent with prior reports but surprising given the opposite metabolic effects of hypo- and hyperthyroidism. PMID:20874768

Thyroid diseases and cerebrovascular disease.

PubMed

Squizzato, A; Gerdes, V E A; Brandjes, D P M; Büller, H R; Stam, J

2005-10-01

Acute cerebral ischemia has been described in different diseases of the thyroid gland, and not only as a result of thyrotoxic atrial fibrillation and cardioembolic stroke. The purpose of this review is to summarize the studies on the relationship between thyroid diseases and cerebrovascular diseases, discussing the main findings for overt hyperthyroidism and hypothyroidism, as well as for subclinical thyroid dysfunction. In overt hyperthyroidism, cardioembolic stroke is clearly associated to thyrotoxic atrial fibrillation, and in subclinical hyperthyroidism with serum thyroid-stimulating hormone levels <0.1 mU/L, the incidence of atrial fibrillation is increased. Although in vitro and in vivo studies indicate a hypercoagulability state in hyperthyroidism, there is insufficient evidence to prove that this state leads to an increased risk of cardiac emboli. However, the hypothesis that overt hyperthyroidism may cause acute cerebral venous thrombosis is intriguing. Possible associations between hyperthyroidism and Moyamoya or Giant cell arteritis have only been described in case reports. There is enough evidence that overt hypothyroidism is associated with several traditional and newer atherosclerotic risk factors, especially hypertension, hyperlipidemia, and hyperhomocysteinemia. For subclinical hypothyroidism, these associations are less certain. Hypothyroidism has been associated with signs of aortic or coronary atherosclerosis, but no case-control or cohort studies have ever investigated hypothyroidism as a possible risk factor for atherothrombotic stroke. Hyperthyroidism is associated with atrial fibrillation and cardioembolic stroke. Hypothyroidism is associated with a worse cardiovascular risk factor profile and leads to progression of atherosclerosis. Associations between hyperthyroidism and acute cerebral venous thrombosis, Moyamoya, and Giant cell arteritis have been suggested, but sound evidence is lacking. Additional studies are needed to clarify these issues.

Beta-adrenergic blockade for the treatment of hyperthyroidism.

PubMed

Geffner, D L; Hershman, J M

1992-07-01

To review the clinical and biochemical effects of beta-adrenergic blocking drugs on hyperthyroidism. Studies published since 1972 were identified through a computerized search of MEDLINE and extensive searching of the bibliographies of the articles identified. Based on an understanding of the differences in beta-blocker metabolism in euthyroid and hyperthyroid patients, we reviewed the differences in pharmacokinetics and metabolic and clinical outcomes during their use in hyperthyroidism, as reported in the articles reviewed. beta Blockers have been used to modify the severity of the hyperadrenergic symptoms of hyperthyroidism for the past 20 years. The clinical efficacy of these agents is affected by hyperthyroid-induced alterations in their gastrointestinal absorption, hepatic metabolism, and renal excretion. The mechanisms whereby these clinical changes are effected is unknown. The agents differ in their beta 1 cardioselectivity, membrane-stabilizing activity, intrinsic sympathomimetic activity, and lipid solubility. They do not appear to alter synthesis or secretion of thyroid hormone by the thyroid gland. Their effects on thyroxine metabolism are contradictory. Decreased thyroxine to triiodothyronine conversion is caused by some, but not all, beta blockers, and this appears to correlate with membrane-stabilizing activity. There does not appear to be any alteration in catecholamine sensitivity during beta-adrenergic blockade. The principal mechanism of action of beta blockers in hyperthyroidism is to antagonize beta-receptor-mediated effects of catecholamines. beta Blockers are effective in treating hypermetabolic symptoms in a variety of hyperthyroid states. Used alone, they offer significant symptomatic relief. They are also useful adjuvants to antithyroid medications, surgery, and radioactive iodide treatment in patients with Graves' disease and toxic nodular goiters.

Grey matter abnormalities in untreated hyperthyroidism: a voxel-based morphometry study using the DARTEL approach.

PubMed

Zhang, Wei; Song, Lingheng; Yin, Xuntao; Zhang, Jiuquan; Liu, Chen; Wang, Jian; Zhou, Daiquan; Chen, Bing; Lii, Haitao

2014-01-01

Hyperthyroidism is frequently associated with pronounced neuropsychiatric symptoms such as impulsiveness, irritability, poor concentration, and memory impairments. Functional neuroimaging has revealed changes in cerebral metabolism in hyperthyroidism, but regional changes in cortical morphology associated with specific neurological deficits have not been studied so far. To investigate the pathophysiology underlying hyperthyroid-associated neural dysfunction, we compared grey matter volume (GMV) between adult hyperthyroid patients and matched healthy controls using voxel-based morphometry (VBM). High resolution 3D T1-weighted images were acquired by 3T MRI from 51 hyperthyroid patients and 51 controls. VBM analysis was performed using SPM8. Correlations between regional GMV and both serum free thyroid hormone (TH) concentrations and disease duration were assessed by multiple regression analysis. Compared to controls, GM volumes in the bilateral hippocampus, parahippocampal gyrus, calcarine, lingual gyrus, and left temporal pole were lower and bilateral supplementary motor area GMV higher in hyperthyroid patients. Serum free triiodothyronine (FT3) concentration was negatively correlated with the normalized regional volume (NRV) of the left parahippocampal gyrus and serum free thyroxine (FT4) concentration negatively correlated with the NRV of the left hippocampus and right parahippocampal gyrus. Disease duration was negatively correlated with the NRV of the left hippocampus, bilateral parahippocampal gyrus, and left temporal pole. Hyperthyroid patients exhibited reduced GMV in regions associated with memory, attention, emotion, vision, and motor planning. Negative correlations between GMV and both free TH and disease duration suggest that chronic TH elevation induces abnormalities in the adult cortex. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Treatment of Hyperthyroidism in Down Syndrome: Case Report and Review of Literature.

ERIC Educational Resources Information Center

Ali, Fawzi E.; Al-Busairi, Waleed A.; Al-Mulla, Fatema A.

1999-01-01

A case of an institutionalized adult male with Down syndrome and hyperthyroidism is reported. After treatment with radioactive iodine, he was found to be markedly hypothyroid when he was reviewed 11 weeks later. Three treatment options for hyperthyroidism in Down syndrome are reviewed: surgery, medical treatments, and radiotherapy. (Author/CR)

[Efficacy of iodine-131 in treating hyperthyroid heart disease].

PubMed

Song, Juan-Juan; Lin, Yan-Song; Zhu, Li; Li, Fang

2013-04-01

To investigate the value of iodine-131 therapy for hyperthyroidism complicated hyperthyroid heart disease(HHD) induced by Graves' disease or Plummer disease. Totally 40 HHD cases who were confirmed in our department from 2009 to 2010 were enrolled in this study. All patients received serum thyroid hormones and associated antibodies tests, 12-lead electrocardiogram, and/or thyroid imaging before and after iodine-131 therapy to access the treatment effectiveness. Among 31 patients with HHD due to Graves' disease and 9 due to Plummer disease, iodine-131 treatment resulted in euthyroidism in 15 and 5 patients and hypothyroid in 7 and 2 patients, while 9 and 2 remain hyperthyroid, respectively.Serum free triiodothyronine, free thyroxine, and thyroid-stimulating hormone were statistically significant(P<0.05) before and after iodine-131 therapy, while no significant difference for serum thyrotrophin receptor antibody, antithyroid peroxidase autoantibody, and anti-thyroglobulin antibody.Atrial fibrillation was the most common cardiac complication of hyperthyroidism(n=25, 62.5%) .The remission rate after iodine-131 treatment was 76.0%. Iodine-131 therapy can effectively and timely control hyperthyroid in HHD patients.

Hyperthyroidism with Periodic Paralysis

PubMed Central

Feldman, David L.; Goldberg, W. M.

1969-01-01

Hyperthyroidism may be associated with hypokalemic periodic paralysis. Two cases are presented demonstrating intermittent attacks of flaccid paralysis associated with clinical symptoms, signs and laboratory findings of hyperthyroidism. During an attack, one patient had a serum potassium of 2.1 mEq. per litre. Various factors such as trauma, exposure to cold, excessive carbohydrate ingestion and certain medications have been stated to precipitate an episode of paralysis. Attacks may range from mild weakness to generalized flaccid paralysis with loss of deep tendon reflexes. Several reported patients have died owing to cardiac arrest or respiratory paralysis. During attacks, the serum potassium is usually in the range of 2.2 to 3.2 mEq. per litre. It is postulated that a metabolic abnormality affecting the muscle-cell membrane can occur in the hyperthyroid state resulting in a shift of potassium to the intracellular position, thus producing a situation of hyperpolarization of the muscle-cell membrane which in turn alters the muscle contractibility. The importance of recognizing the unusual association of hypokalemic periodic paralysis with hyperthyroidism is stressed because, with successful treatment of the hyperthyroidism, the episodes of paralysis disappear. PMID:5353150

Assessment of bone metabolism in premenopausal females with hyperthyroidism and hypothyroidism.

PubMed

Tuchendler, Dominika; Bolanowski, Marek

2013-01-01

Osteoporosis is one of the commonest metabolic diseases of bone. Its possible causes may include thyroid hormonal dysfunction. The objective of this study was to evaluate the effects of hyperthyroidism and hypothyroidism on osseous tissue metabolism in premenopausal women. 38 women with hyperthyroidism, 40 with hypothyroidism and 41 healthy women participated in this study. Initially after 6 and 12 months, each patient underwent selected hormonal, immunological and biochemical tests, measurement of concentrations of bone turnover markers and densitometry were also performed. On initial evaluation, lower cortical bone density was found in patients with hyperthyroidism (femoral neck). After 12 months, an increase in BMD was seen, but it was still lower than in the control group. Statistically significantly higher concentrations of bone turnover markers, decreasing from the sixth month of treatment, were noted only in the group with hyperthyroidism. Statistically significant differences were not noted in the femoral neck nor in the lumbar spine BMD in patients with hypothyroidism. Hyperthyroidism poses a negative effect on bone metabolism. Hypothyroidism in premenopausal females does not have any influence on bone density.

Update on subclinical hyperthyroidism.

PubMed

Donangelo, Ines; Braunstein, Glenn D

2011-04-15

Subclinical hyperthyroidism is defined by low or undetectable serum thyroid-stimulating hormone levels, with normal free thyroxine and total or free triiodothyronine levels. It can be caused by increased endogenous production of thyroid hormone (as in Graves disease or toxic nodular goiter), administration of thyroid hormone for treatment of malignant thyroid disease, or unintentional excessive thyroid hormone therapy. The rate of progression to overt hyperthyroidism is higher in persons who have suppressed thyroid-stimulating hormone levels compared with those who have low but detectable levels. Subclinical hyperthyroidism is associated with an increased risk of atrial fibrillation in older adults, and with decreased bone mineral density in postmenopausal women; however, the effectiveness of treatment in preventing these conditions is unknown. There is lesser-quality evidence suggesting an association between subclinical hyperthyroidism and other cardiovascular effects, including increased heart rate and left ventricular mass, and increased bone turnover markers. Possible associations between subclinical hyperthyroidism and quality of life parameters, cognition, and increased mortality rates are controversial. Prospective randomized controlled trials are needed to address the effects of early treatment on potential morbidities to help determine whether screening should be recommended in the asymptomatic general population.

Influence of thyroid disorders on the kidney expression and plasma activity of aminopeptidase A.

PubMed

Wangensteen, R; Segarra, A B; Ramirez-Sanchez, M; Gasparo, M De; Dominguez, G; Banegas, I; Vargas, F; Vives, F; Prieto, I

2015-04-01

Thyroid disorders may affect blood pressure and renal function modifying factors of the plasmatic and kidney renin-angiotensin system such as aminopeptidase A (AP A) that metabolizes angiotensin II to angiotensin III. We investigated the expression of AP A in the kidney, as well as its enzymatic activity in the plasma of euthyroid, hyperthyroid, and hypothyroid adult male rats. Hyperthyroidism was induced by daily subcutaneous injections of tetraiodothyronine. Hypothyroid rats were obtained by administration of methimazole in drinking water. Expression of AP A was determined by Western blot analysis. Plasma AP A activity was measured fluorometrically using glutamyl-β-naphthylamide as substrate. While hyperthyroid rats exhibited lower levels of plasma AP A activity than controls, the kidney of hyperthyroid animals expressed significantly higher AP A than controls and hypothyroid animals. A discrepancy between the high expression of AP A in kidney of hyperthyroid rats and the low activity of AP A measured in plasma and kidney of hyperthyroid animals was found. The posttranslational influence of environmental biochemical factors may be in part responsible for that divergence.

The role of short- and long-term cognitive empathy activation in preventing cyberbystander reinforcing cyberbullying behavior.

PubMed

Barlińska, Julia; Szuster, Anna; Winiewski, Mikołaj

2015-04-01

The long- versus short-term effectiveness of empathy activation on reducing bystander behavior reinforcing cyberbullying was tested. The focus was on limiting the frequency of forwarding a message ridiculing a peer. Experimental research on adolescent students was conducted in conditions simulating online contact. The results confirmed the significance of cognitive empathy activated immediately prior to decision making on limiting involvement in reinforcing cyberbullying behavior. The long-term impact of empathy was markedly limited.

A case report of neonatal thyrotoxicosis due to maternal autoimmune hyperthyroidism.

PubMed

Markham, Lori A; Stevens, Debra L

2003-12-01

A case of neonatal thyrotoxicosis secondary to maternal autoimmune hyperthyroidism is reported in an infant born at 34 weeks gestation who presented with tachycardia, jitteriness, diarrhea, and a small goiter. Propranolol and oxygen were used to treat high-output cardiac failure and transient persistent pulmonary hypertension. The infant's response to propylthiouracil therapy, gradual resolution of cardiac and systemic symptoms, and normaliziation of thyroid studies are described. Thyroid physiology and function and the special considerations in a premature infant are reviewed. An overview of maternal autoimmune hyperthyroidism and the implications for the developing fetus and neonate are presented. The risk factors for, and clinical presentation of, hyperthyroidism are outlined and treatment strategies highlighted. The nursing care of infants with hyperthyroidism is carefully described with an emphasis on the surveillance for and management of multisystem manifestations.

Fetal neonatal hyperthyroidism: diagnostic and therapeutic approachment

PubMed Central

Kurtoğlu, Selim; Özdemir, Ahmet

2017-01-01

Fetal and neonatal hyperthyroidism may occur in mothers with Graves’ disease. Fetal thyrotoxicosis manifestation is observed with the transition of TSH receptor stimulating antibodies to the fetus from the 17th–20th weeks of pregnancy and with the fetal TSH receptors becoming responsive after 20 weeks. The diagnosis is confirmed by fetal tachycardia, goiter and bone age advancement in pregnancy and maternal treatment is conducted in accordance. The probability of neonatal hyperthyroidism is high in the babies of mothers that have ongoing antithyroid requirement and higher antibody levels in the last months of pregnancy. Clinical manifestation may be delayed by 7–17 days because of the antithyroid drugs taken by the mother. Neonatal hyperthyroidism symptoms can be confused with sepsis and congenital viral infections. Herein, the diagnosis and therapeutic approach are reviewed in cases of fetal neonatal hyperthyroidism. PMID:28439194

In search of consolidation of short-term memory in nonhuman animals.

PubMed

Calder, Amanda; White, K Geoffrey

2014-03-01

Wixted (Annual Review of Psychology, 55, 235 – 269, 2004) has argued that forgetting is due to consolidation failure. Previous research with humans and nonhuman animals has reported evidence for consolidation in intermediate or long-term memory (LTM). The present study examines whether consolidation occurs in short-term memory in pigeons. Delayed matching-to-sample accuracy was reduced when retroactive interference (an extraneous task in Experiment 1 or houselight illumination in Experiment 2) was interpolated in the retention interval. Accuracy was not greater, however, when interference occurred at the end of the retention interval, as compared with when it occurred at the beginning. That is, there was no evidence for consolidation in short-term memory for pigeons. We did find, however, the beginning–end effect originally reported by Roberts and Grant (Journal of Experimental Psychology: Animal Behavior Processes, 4, 219–236, 1978) and the recovery from forgetting reported by White and Brown (Journal of the Experimental Analysis of Behavior, 96, 177–189, 2011). The results are discussed in relation to temporal distinctiveness theory as an alternative to consolidation.

Association of Polybrominated Diphenyl Ethers (PBDEs) and Polychlorinated Biphenyls (PCBs) with Hyperthyroidism in Domestic Felines, Sentinels for Thyroid Hormone Disruption.

PubMed

Walter, Kyla M; Lin, Yan-Ping; Kass, Philip H; Puschner, Birgit

2017-05-03

Hyperthyroidism is the most common endocrine disorder observed in domestic felines; however, its etiology is largely unknown. Two classes of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are known to interfere with thyroid hormone (TH) signaling and regulation; thus, it is postulated that they contribute to the etiopathogenesis of feline hyperthyroidism and pose a risk to humans and other species. In this case-control study, the concentrations of 13 PBDE and 11 PCB congeners were measured by gas chromatography mass spectrometry in serum or plasma samples from 20 hyperthyroid and 31 control cats in order to investigate the association between concentration of PBDE and PCB congeners and feline hyperthyroidism. Logistic regression analysis was used to determine whether elevated concentrations of individual congeners were associated with a higher risk of feline hyperthyroidism. Hyperthyroid cats had higher concentrations of four PBDE congeners (BDE17, BDE100, BDE47, and BDE49) and five PCB congeners (PCB131, PCB153, PCB174, PCB180, and PCB196), compared to control cats. In addition, the sum of both PBDE and PCB congener concentrations were elevated in the hyperthyroid group compared to control cats; however, only the increased PCB concentrations were statistically significant. The sum total PBDE concentrations in our feline samples were approximately 50 times greater than concentrations previously reported in human populations from a geographically similar area, whereas sum total PCB concentrations were comparable to those previously reported in humans. These observational findings support the hypothesis that PBDEs and PCBs may contribute to the etiopathogenesis of hyperthyroidism in felines. As domestic house cats are often exposed to higher concentrations of PBDEs than humans, they may serve as sentinels for the risk of TH disruption that these pollutants pose to humans and other species.

Multicompartmental model for iodide, thyroxine, and triiodothyronine metabolism in normal and spontaneously hyperthyroid cats

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

Hays, M.T.; Broome, M.R.; Turrel, J.M.

A comprehensive multicompartmental kinetic model was developed to account for the distribution and metabolism of simultaneously injected radioactive iodide (iodide*), T3 (T3*), and T4 (T4*) in six normal and seven spontaneously hyperthyroid cats. Data from plasma samples (analyzed by HPLC), urine, feces, and thyroid accumulation were incorporated into the model. The submodels for iodide*, T3*, and T4* all included both a fast and a slow exchange compartment connecting with the plasma compartment. The best-fit iodide* model also included a delay compartment, presumed to be pooling of gastrosalivary secretions. This delay was 62% longer in the hyperthyroid cats than in themore » euthyroid cats. Unexpectedly, all of the exchange parameters for both T4 and T3 were significantly slowed in hyperthyroidism, possibly because the hyperthyroid cats were older. None of the plasma equivalent volumes of the exchange compartments of iodide*, T3*, or T4* was significantly different in the hyperthyroid cats, although the plasma equivalent volume of the fast T4 exchange compartments were reduced. Secretion of recycled T4* from the thyroid into the plasma T4* compartment was essential to model fit, but its quantity could not be uniquely identified in the absence of multiple thyroid data points. Thyroid secretion of T3* was not detectable. Comparing the fast and slow compartments, there was a shift of T4* deiodination into the fast exchange compartment in hyperthyroidism. Total body mean residence times (MRTs) of iodide* and T3* were not affected by hyperthyroidism, but mean T4* MRT was decreased 23%. Total fractional T4 to T3 conversion was unchanged in hyperthyroidism, although the amount of T3 produced by this route was increased nearly 5-fold because of higher concentrations of donor stable T4.« less

Leptin and ghrelin concentration in hyperthyroid cats before and after radioactive iodine therapy compared to euthyroid control cats.

PubMed

Marsilio, Sina; Glanemann, Barbara; Martin, Lucile; Szladovits, Balazs; Neiger, Reto

2017-04-19

Leptin and ghrelin, two peptide hormones with antagonistic effects on satiety and energy balance, could be involved in the pathogenesis of weight loss and polyphagia in cats with hyperthyroidism. Leptin generally decreases appetite and increases energy expenditure, while ghrelin exerts the opposite effects. Leptin and ghrelin were measured in 42 client owned hyperthyroid cats with a body condition score (BCS) ≤ 5/9 before (T0) and 4 weeks after radioactive iodine treatment (RAIT) (T1). Dependent on the serum total thyroxine concentration concentration at T1, cats were sub-classified as still hyperthyroid (ht-ht) (n = 4), euthyroid (ht-eu) (n = 10) or hypothyroid (ht-hypo) (n = 28). Results were compared to those of 22 healthy, euthyroid control cats with a comparable BCS (≤ 5/9) and age (≥ 8 years) to hyperthyroid cats. At T0, there were no significant differences between hyperthyroid and control cats for leptin (p = 0.06) or ghrelin concentrations (p = 0.27). At T1, leptin significantly decreased in ht-hypo cats compared to T0 (p = 0.0008) despite a significantly increased body weight in this group (p = 0.0001). Serum ghrelin concentrations did not differ between hyperthyroid cats with a history of polyphagia compared to non-polyphagic cats (p = 0.42). After RAIT, ghrelin concentration significantly increased in all hyperthyroid cats (p < 0.0001), as well as in the subgroups ht-eu (p = 0.014) and ht-hypo (p < 0.0001) compared to their respective T0 baseline concentrations. Leptin and ghrelin fluctuations may be indicative of changes in metabolic functions in cats with thyroid dysfunction. Leptin fluctuations occurred independently of body weight in different states of thyroid dysfunction; increasing ghrelin concentrations after RAIT suggest a ghrelin-independent mechanism for polyphagia in hyperthyroid cats.

Effect of di(n-butyl) phthalate on testicular oxidative damage and antioxidant enzymes in hyperthyroid rats.

PubMed

Lee, Ena; Ahn, Mee Young; Kim, Hee Jin; Kim, In Young; Han, Soon Young; Kang, Tae Seok; Hong, Jin Hwan; Park, Kui Lea; Lee, Byung Mu; Kim, Hyung Sik

2007-06-01

This study compared the effects of di(n-butyl) phthalate (DBP) on the oxidative damage and antioxidant enzymes activity in testes of hyperthyroid rats. Hyperthyroidism was induced in pubertal male rats by intraperitoneal injection of triiodothyronine (T3, 10 microg/kg body weight) for 30 days. An oral dose of DBP (750 mg/kg) was administered simultaneously to normal or hyperthyroid (T3) rats over a 30-day period. No changes in body weight were observed in the hyperthyroid groups (T3, T3 + DBP) compared with controls. There were significantly higher serum T3 levels observed in the hyperthyroid rats than in the control, but the serum thyroid stimulating hormone levels were markedly lower in the hyperthyroid rats. DBP significantly decreased the weight of the testes in the normal (DBP) and hyperthyroid (T3 + DBP) groups. The serum testosterone concentrations were significantly lower in only DBP group. DBP significantly increased the 8-hydroxy-2-deoxyguanosine (8-OHdG) level in the testes, whereas the DBP-induced 8-OHdG levels were slightly higher in T3 + DBP group. Superoxide dismutase and glutathione peroxidase activities were significantly higher in the testes of the DBP or T3 + DBP groups. Catalase (CAT) activity was significantly higher in the DBP treatment group, but the T3 + DBP group showed slightly lower DBP-induced CAT activity. The testicular expression of thyroid hormone receptor alpha-1 (TRalpha-1) was significantly higher in the DBP groups, and androgen receptor (AR) expression was not detected in the DBP treatment group. In addition, DBP significantly increased the peroxisome proliferator-activated receptor-r (PPAR-r) levels in the testis. These results suggest that hyperthyroidism can cause a change in the expression level of PPAR-r in testes, and may increase the levels of oxidative damage induced by the metabolic activation of DBP.

Hyperthyroidism incidence fluctuates widely in and around pregnancy and is at variance with some other autoimmune diseases: a Danish population-based study.

PubMed

Andersen, Stine Linding; Olsen, Jørn; Carlé, Allan; Laurberg, Peter

2015-03-01

Hyperthyroidism in women of reproductive age is predominantly caused by Graves' disease. Pregnancy associated changes in the immune system may influence the onset of disease, but population-based incidence rates in and around pregnancy have not been reported. The objective of the study was to estimate the incidence of maternal hyperthyroidism (defined by redeemed prescription of antithyroid drugs) in and around pregnancy and to compare this with the incidence of other autoimmune diseases such as rheumatoid arthritis (RA) and inflammatory bowel disease (IBD). This was a population-based cohort study. The study used the Danish nationwide registers. The participants were women who gave birth to singleton liveborn children in Denmark from 1999 to 2008 (n = 403,958). Incidence rates (IR) of maternal hyperthyroidism during a 4-year period beginning 2 years before and ending 2 years after the date when the mother was giving birth for the first time in the study period were measured. Altogether 3673 women (0.9%) were identified with an onset of hyperthyroidism from 1997 to 2010, and the overall IR of maternal hyperthyroidism was 65.0/100,000/year. The IR of hyperthyroidism in and around pregnancy varied widely and was high in the first 3 months of pregnancy [incidence rate ratio (IRR) vs the remaining study period: 1.50 (95% CI 1.09-2.06)), very low in the last 3 months of pregnancy (0.26 (0.15-0.44)], and reached the highest level 7-9 months postpartum [3.80 (2.88-5.02)]. The incidence variation in and around pregnancy was different for RA and IBD. These are the first population-based data on the incidence of hyperthyroidism in and around pregnancy. The incidence of hyperthyroidism was high in early pregnancy and postpartum, whereas such particular pattern was not observed for other diseases of autoimmune origin.

Lithium-associated hyperthyroidism.

PubMed

Siyam, Fadi F; Deshmukh, Sanaa; Garcia-Touza, Mariana

2013-08-01

Goiters and hypothyroidism are well-known patient complications of the use of lithium for treatment of bipolar disease. However, the occurrence of lithium-induced hyperthyroidism is a more rare event. Many times, the condition can be confused with a flare of mania. Monitoring through serial biochemical measurement of thyroid function is critical in patients taking lithium. Hyperthyroidism induced by lithium is a condition that generally can be controlled medically without the patient having to discontinue lithium therapy, although in some circumstances, discontinuation of lithium therapy may be indicated. We report on a patient case of lithium-associated hyperthyroidism that resolved after discontinuation of the medication.

Advances in assessment, diagnosis, and treatment of hyperthyroidism in children.

PubMed

Amer, Kim Siarkowski

2005-04-01

The thyroid gland is responsible for regulating multiple complex metabolic processes that affect most organs. Physical growth and cognitive development are dependent on proper levels of thyroid hormone. This article will review common challenges in the diagnosis of hyperthyroidism in children, the approaches to treatment, and the nursing interventions guided toward child and family responses to thyroid disease. A comparison of signs and symptoms of hypothyroidism and hyperthyroidism is also included. The nursing interventions addressed in the article integrate the biological, psychological, social, and environmental stresses and adaptations necessary to cope with hyperthyroid disease.

Management of hyperthyroidism due to Graves' disease: frequently asked questions and answers (if any).

PubMed

Bartalena, L; Chiovato, L; Vitti, P

2016-10-01

Graves' disease is the most common cause of hyperthyroidism in iodine-replete areas. Although progress has been made in our understanding of the pathogenesis of the disease, no treatment targeting pathogenic mechanisms of the disease is presently available. Therapies for Graves' hyperthyroidism are largely imperfect because they are bound to either a high rate of relapsing hyperthyroidism (antithyroid drugs) or lifelong hypothyroidism (radioiodine treatment or thyroidectomy). Aim of the present article is to offer a practical guidance to the reader by providing evidence-based answers to frequently asked questions in clinical practice.

Hyperthyroidism. Causes, clinical features, and diagnosis.

PubMed

Spaulding, S W; Lippes, H

1985-09-01

The usual patient with hyperthyroidism has Graves' disease: If serum levels of thyroid hormone are clearly elevated, the presence of infiltrative ophthalmopathy or pretibial myxedema is probably sufficient for establishing the diagnosis. However, if the ancillary findings of Graves' are not present, the radioactive iodine uptake should be determined to rule out other possible etiologies of hyperthyroidism. Signs of hyperthyroidism may be subtle or misleading, particularly in the elderly; the well-informed clinician keeps the diagnosis in mind, and if the initial thyroid hormone tests are not definitive, employs additional tests that are cost-effective in the individual clinical situation.

Histomorphometry and expression of CDC-47 and caspase-3 in mammary glands of pregnant female rats with artificial hyperthyroidism.

PubMed

Leite, Eveline Dias; de Freitas, Edmilson Santos; de Almeida Souza, Cintia; de Melo Ocarino, Natalia; Cassali, Geovanni Dantas; Serakides, Rogéria

2008-01-01

The purpose of this study was to evaluate the effect of hyperthyroidism on mammary gland development and expression of two protein markers, CDC-47 for proliferation and caspase-3 for apoptosis in pregnant female rats. Thirty-six adult female Wistar rats were used in two groups: hyperthyroid and control. Rats were mated 60 days after the onset of thyroxine administration. Six animals/group were sacrificed on gestation days 7, 14, and 19. Artificial hyperthyroidism was induced by daily administration of thyroxine in the drinking water until the end of gestation. At the end of each period, rats were sacrificed, and their inguinal mammary glands were collected and processed for morphometric analysis. The percentages of epithelium, stroma, adipose tissue, and lacteal secretion were determined. Immunohistochemical analysis was also carried out using anti-CDC-47 and anti-caspase-3 antibodies to study proliferation and apoptosis, respectively. On the 19th day of gestation, thyroxine treatment significantly increased the percentage of mammary epithelium. Hyperthyroidism, however, did not change CDC-47 expression. The hyperthyroid group presented early lactogenesis and significantly larger lacteal secretion on the 19th day of gestation. There was no significant difference in caspase-3 expression between groups in any period. We may conclude that hyperthyroidism accelerates mammary gland development and increases lacteal secretion during gestation without increasing the proliferation rate and the expression of caspase-3.

Interventions for hyperthyroidism pre-pregnancy and during pregnancy.

PubMed

Earl, Rachel; Crowther, Caroline A; Middleton, Philippa

2013-11-19

Women with hyperthyroidism in pregnancy have increased risks of miscarriage, stillbirth, preterm birth, and intrauterine growth restriction; and they can develop severe pre-eclampsia or placental abruption. To identify interventions used in the management of hyperthyroidism pre-pregnancy or during pregnancy and to ascertain the impact of these interventions on important maternal, fetal, neonatal and childhood outcomes. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2013). We planned to include randomised controlled trials, quasi-randomised controlled trials, and cluster-randomised trials comparing antithyroid interventions for hyperthyroidism pre-pregnancy or during pregnancy with another intervention or no intervention (placebo or no treatment). Two review authors assessed trial eligibility and planned to assess trial quality and extract the data independently. No trials were included in the review. As we did not identify any eligible trials, we are unable to comment on implications for practice, although early identification of hyperthyroidism before pregnancy may allow a woman to choose radioactive iodine therapy or surgery before planning to have a child. Designing and conducting a trial of antithyroid interventions for pregnant women with hyperthyroidism presents formidable challenges. Not only is hyperthyroidism a relatively rare condition, both of the two main drugs used have potential for harm, one for the mother and the other for the child. More observational research is required about the potential harms of methimazole in early pregnancy and about the potential liver damage from propylthiouracil.

Human chorionic gonadotropin-induced hyperthyroidism in germ cell cancer--a case presentation and review of the literature.

PubMed

Voigt, Wieland; Maher, Gita; Wolf, Hans-Heinrich; Schmoll, Hans-Joachim

2007-06-01

Human chorionic gonadotropin (hCG)-induced hyperthyroidism represents a rare paraneoplastic syndrome in hCG-secreting testicular cancer. In most cases, this hyperthyroidism remains subclinical. hCG belongs to the family of glycoprotein hormones with structural homology to thyroid- stimulating hormone (TSH). The thyrotropic potency and thereby the degree of cross reactivity of hCG is determined by several factors, such as content of sialic acid or lack of the C-terminal tail. In the absence of clinical signs of hyperthyroidism, treatment usually consists of specific antitumor therapy which will result in normalization of thyroid function if hCG declines. Where there are clinical signs of hyperthyroidism, overlapping thyreostatic treatment is recommended. Here, we report of a young man presenting biochemical signs of hyperthyroidism without clinical signs at the time of diagnosis of non-seminomatous germ cell cancer. Beta-hCG initially exceeded 1,000,000 IU/ml and declined close to normal at the end of cancer treatment. Concomitantly, thyroid hormones returned to the normal range without any thyreostatic therapy. We observed a significant correlation of neta-hCG and thyroid hormones in linear regression analysis (r2 = 0.98, p< 0.05). A concise overview of potential mechanisms of hCG-induced hyperthyroidism in germ cell cancer but also in pregnancy is given and the case discussed according to the cited literature.

Oxidative stress markers during a course of hyperthyroidism.

PubMed

Lampka, Magdalena; Junik, Roman; Nowicka, Anna; Kopczyńska, Ewa; Tyrakowski, Tomasz; Odrowaz-Sypniewska, Grazyna

2006-01-01

Previous studies have shown the presence of oxidative stress in hyperthyroid patients. The aim of this study was to evaluate the influence of hyperthyroidism on lipid peroxidation, plasma lipoprotein oxidation and antioxidant status. We have estimated the clinical utility of the biochemical parameters analysed as markers of oxidative stress in hyperthyroidism. Twenty five patients with overt hyperthyroidism because of Graves' disease or toxic multinodular goitre and 20 healthy subjects were included in the study. Lipid peroxidation was evaluated by measurement of peroxides and malondialdehyde with 4-hydroxynonenal (MDA + 4-HNE) concentrations. Autoantibodies against oxidised LDL (anti-oxLDL) were assayed as a marker of lipoprotein oxidation. Changes in the antioxidant defence system were estimated by measurement of total antioxidant status in serum (TAS) and erythrocyte superoxide dismutase activity (SOD). A significant increase in serum concentration of peroxides and MDA + 4-HNE was observed in patients with hyperthyroidism. However, no difference was found in anti-oxLDL concentration and antioxidant status parameters (TAS, SOD) between the control group and the patient group. Our results indicate an intensification of the oxidative processes caused by an excess of thyroid hormones, which is not accompanied by a response from the antioxidant system. Elevated concentrations of lipid peroxidation products in serum, both peroxides and malondialdehyde with 4-hydroxynonenal, may be useful as markers of oxidative stress during the course of hyperthyroidism.

Sympathovagal imbalance in thyroid dysfunctions in females: correlation with thyroid profile, heart rate and blood pressure.

PubMed

Karthik, S; Pal, G K; Nanda, Nivedita; Hamide, Abdoul; Bobby, Zachariah; Amudharaj, D; Pal, Pravati

2009-01-01

The aim of the study was to investigate the role of spectral analysis of heart rate variability (HRV) for assessing the type and degree of sympathovagal imbalance (SVI) and their link to cardiovascular morbidities in thyroid dysfunctions. Forty-five female subjects (15 control subjects and freshly diagnosed untreated 15 hypothyroid and 15 hyperthyroid patients) were recruited for the study. Thyroid profile, body mass index (BMI), basal heart rate (BHR), blood pressure (BP) and spectral indices of HRV (TP, LFnu, HFnu and LF-HF ratio, mean RR, SDNN and RMSSD) were assessed in all the three groups. LF-HF ratio was correlated with thyroid profile, BMI, BHR and BP. SVI was more prominent in hyperthyroid (P < 0.001) compared to hypothyroid (P < 0.05) subjects. LF-HF ratio was correlated with thyroid profile in both hypo and hyperthyroid subjects; but correlation with BHR and BP was significant only in hyperthyroidism. Though the SVI was found to be due to both vagal withdrawal and sympathetic activation, especially in hyperthyroidism, contribution by vagal inhibition was prominent. Vagal inhibition contributes significantly to SVI in thyroid dysfunctions, especially in hyperthyroidism. As the present study indicates poor cardiovascular health due to vagal inhibition in patients suffering from thyroid dysfunctions, attempt should be made to improve vagal tone especially in hyperthyroid subjects to attain a stable sympathovagal and cardiovascular homeostasis.

Reduced posterior cingulate glutamate measured by magnetic resonance spectroscopy in hyperthyroidism.

PubMed

Liu, Xinxin; Bai, Zhilan; Liu, Feng; Li, Min; Zhang, Qiujuan; Song, Guangyi; Xu, Jing

2012-01-01

Patients with hyperthyroidism frequently have neuropsychiatric complaints such as lack of concentration, poor performance in memory, depression, anxiety and mania. These symptoms suggest the dysfunction of brain. However, the underlying process of this dysfunction is not well understood. At the same time, glutamatergic system has been considered important in neuropsychiatric process by recent studies. Thus, this study is to investigate the change of glutamate concentration in patients with hyperthyroidism using proton magnetic resonance spectroscopy. Fifteen untreated patients with hyperthyroidism and fifteen age- and gender- matched controls participated in the study. The region of the posterior cingulate cortex was examined by magnetic resonance spectroscopy with a technique referred as TE-averaged PRESS at 3T field strength. The concentrations of N-Acetylaspartate, creatine, choline and glutamate were assessed using jMRUI v4.0 software. Hyperthyroid patients, compared with controls, showed a decrease of glutamate concentration (P<0.047) and glutamate/creatine ratios (P<0.009) in the posterior cingulate cortex. The decrease of choline concentration (P<0.004) and choline/creatine ratios (P<0.012) were also discovered. No significant difference was found in the concentrations of N-Acetylaspartate or creatine between patients and controls. Concentration of glutamate decreased in the region of posterior cingulate cortex in patients with hyperthyroidism. This reduction indicated a possible involvement of glutamate in the brain dysfunction in hyperthyroidism.

Hyperfunctioning thyroid cancer: a five-year follow-up.

PubMed

Azevedo, Monalisa Ferreira; Casulari, Luiz Augusto

2010-02-01

Differentiated thyroid cancer rarely occurs in association with hyperfunctioning nodules. We describe a case of a 47-year-old woman who developed symptoms of hyperthyroidism associated with a palpable thyroid nodule. Thyroid scintigraphy showed an autonomous nodule, and fine-needle aspiration biopsy was suggestive of papillary carcinoma. Laboratorial findings were consistent with the diagnosis of hyperthyroidism. The patient underwent thyroidectomy and a papillary carcinoma of 3.0 x 3.0 x 2.0 cm, follicular variant, was described by histological examination. The surrounding thyroid tissue was normal. Postoperatively, the patient received 100 mCi of (131)I, and whole body scans detected only residual uptake. No evidence of metastasis was detected during five years of follow-up. Hot thyroid nodules rarely harbor malignancies, and this case illustrated that, when a carcinoma occurs the prognosis seems to be very good with no evidence of metastatic dissemination during a long-term follow-up.

Quality of life, clinical outcomes and safety of early prophylactic levothyroxine administration in patients with Graves' hyperthyroidism undergoing radioiodine therapy: a randomized controlled study.

PubMed

Taïeb, David; Bournaud, Claire; Eberle, Marie-Claude; Catargi, Bogdan; Schvartz, Claire; Cavarec, Marie-Béatrice; Faugeron, Isabelle; Toubert, Marie-Elisabeth; Benisvy, Danielle; Archange, Cendrine; Mundler, Olivier; Caron, Philippe; Abdullah, Ahmad Esmaeel; Baumstarck, Karine

2016-04-01

While radioiodine therapy is commonly used for treating Graves' disease, a prolonged and clinical hypothyroidism may result in disabling symptoms leading to deterioration of quality of life (QoL) of patients. Introducing levothyroxine (LT4) treatment in the early post-therapeutic period may be an interesting approach to limit this phenomenon. A multicenter, prospective, open-label randomized controlled trial enrolled 94 patients with Graves' hyperthyroidism randomly assigned to the experimental group (n=46) (group A: early prophylactic LT4 treatment) or the control group (n=48) (group B: standard follow-up). The primary endpoint was the 6-month QoL. The secondary endpoints were other QoL scores such as Graves' ophthalmopathy (GO) outcomes, thyroid function tests and safety. The primary endpoint at 6 months was achieved: the mental composite score (MCS) of Short Form 36 (SF-36) was significantly higher in group A compared to group B (P=0.009). Four other dimension scores of the SF-36 and four dimension scores of the thyroid-specific patient-reported outcome (ThyPRO) significantly differed between the two groups, indicating better QoL in group A. After adjustment for variables, the early LT4 administration strategy was found as an independent factor for only two scores of SF-36: the MCS and the general health (GH) score. There were no differences in GO, final thyroid status and changes in the anti-TSH receptor antibodies (TRAbs) levels between the two groups. No adverse cardiovascular event was reported. Early LT4 administration post-radioactive iodine (RAI) could represent a safe potential benefit for patients with regard to QoL. The optimal strategy taking into account administered RAI activities and LT4 treatment dosage and timing remains to be determined. © 2016 European Society of Endocrinology.

Effects of Short-Term Thermal Alteration on Organic Matter in Experimentally-Heated Tagish Lake Observed by Raman Spectroscopy

NASA Technical Reports Server (NTRS)

Chan, Q. H. S.; Nakato, A.; Zolensky, M. E.; Nakamura, T.; Kebukawa, Y.

2007-01-01

Carbonaceous chondrites exhibit a wide range of aqueous and thermal alteration characteristics. Examples of the thermally metamorphosed carbonaceous chondrites (TMCCs) include the C2-ung/CM2TIVs Belgica (B)-7904 and Yamato (Y) 86720. The alteration extent is the most complete in these meteorites and thus they are considered typical end-members of TMCCs exhibiting complete dehydration of matrix phyllosilicates [1, 2]. The estimated heating conditions are 10 to 10(sup 3) days at 700 C to 1 to 100 hours at 890 C, i.e. short-term heating induced by impact and/or solar radiation [3]. The chemical and bulk oxygen isotopic compositions of the matrix of the carbonate (CO3)-poor lithology of the Tagish Lake (hereafter Tag) meteorite bears similarities to these TMCCs [4]. We investigated the experimentally-heated Tag with the use of Raman spectroscopy to understand how short-term heating affects the maturity of insoluble organic matter (IOM) in aqueously altered meteorites.

Short-term effects of different genetically modified maize varieties on arthropod food web properties: an experimental field assessment.

PubMed

Szénási, Ágnes; Pálinkás, Zoltán; Zalai, Mihály; Schmitz, Oswald J; Balog, Adalbert

2014-06-17

There is concern that genetically modified (GM) plants may have adverse affects on the arthropod biodiversity comprising agricultural landscapes. The present study report on a two year field experimental test of whether four different genotypic lines, some are novel with no previous field tests, of GM maize hybrids alter the structure of arthropod food webs that they harbour, relative to non-GM maize (control) that is widely used in agriculture. The different GM genotypes produced either Bt toxins, conferred glyphosate tolerance or a combination of the two traits. Quantitative food web analysis, based on short-term assessment assigning a total of 243,896 arthropod individuals collected from the treatments to their positions in food webs, revealed that complex and stable food webs persisted in each maize treatment. Moreover, food web structure remained relatively unchanged by the GM-genotype. The results suggest that at least in short-term period these particular GM maize genotypes will not have adverse effects on arthropod biota of agricultural landscapes.

Experimental Hyperthyroidism Decreases Gene Expression and Serum Levels of Adipokines in Obesity

PubMed Central

Luvizotto, Renata de Azevedo Melo; do Nascimento, André Ferreira; de Síbio, Maria Teresa; Olímpio, Regiane Marques Castro; Conde, Sandro José; Lima-Leopoldo, Ana Paula; Leopoldo, André Soares; Cicogna, Antonio Carlos; Nogueira, Célia Regina

2012-01-01

Aims. To analyze the influence of hyperthyroidism on the gene expression and serum concentration of leptin, resistin, and adiponectin in obese animals. Main Methods. Male Wistar rats were randomly divided into two groups: control (C)—fed with commercial chow ad libitum—and obese (OB)—fed with a hypercaloric diet. After group characterization, the OB rats continued receiving a hypercaloric diet and were randomized into two groups: obese animals (OB) and obese with 25 μg triiodothyronine (T3)/100 BW (OT). The T3 dose was administered every day for the last 2 weeks of the study. After 30 weeks the animals were euthanized. Samples of blood and adipose tissue were collected for biochemical and hormonal analyses as well as gene expression of leptin, resistin, and adiponectin. Results. T3 treatment was effective, increasing fT3 levels and decreasing fT4 and TSH serum concentration. Administration of T3 promotes weight loss, decreases all fat deposits, and diminishes serum levels of leptin, resistin, and adiponectin by reducing their gene expression. Conclusions. Our results suggest that T3 modulate serum and gene expression levels of leptin, resistin, and adiponectin in experimental model of obesity, providing new insights regarding the relationship between T3 and adipokines in obesity. PMID:22645452

Delayed cerebral development in twins with congenital hyperthyroidism.

PubMed

Kopelman, A E

1983-09-01

Twins had congenital hyperthyroidism and delayed cerebral development manifested as ventriculomegaly, increased space in the interhemispheric fissure, and an exaggerated gyral pattern on cranial computed tomographic scans. At 3 1/2 years of age, both children had delayed development. Fetal and neonatal hyperthyroidism may interfere with normal brain growth and maturation with both neuranatomic and developmental sequelae.

Surgical Intervention for Medically Refractory Hyperthyroidism.

PubMed

Knollman, Philip D; Giese, Ann; Bhayani, Mihir K

2016-05-01

Pediatric hyperthyroidism can be multifactorial, with Graves' disease (GD) being the most common etiology. Treatment focuses on identification of the cause of the hyperthyroidism and achieving a biochemical cure with symptom resolution. This article highlights the clinical presentation, diagnosis, and treatment of a pediatric patient with GD. [Pediatr Ann. 2016;45(5):e171-e175.]. Copyright 2016, SLACK Incorporated.

Thyrotoxic Atrial Fibrillation

PubMed Central

Parmar, Malvinder S.

2005-01-01

Abstract and Introduction Abstract Atrial fibrillation is the most common cardiac complication of hyperthyroidism and occurs in 15% of patients with hyperthyroidism. It is associated with a higher risk of thromboembolism that often involves the central nervous system. Oral anticoagulation is important in the majority of these patients to prevent thromboembolic complications. These patients require adjustment in the dose of various rate-controlling agents because of increased clearance associated with hyperthyroidism and a decrease in warfarin dosage because of increased clearance of vitamin K-dependent clotting factors. The management of thyrotoxic atrial fibrillation is summarized in this clinical review. Introduction A 52-year-old woman presents with symptoms of palpitations and mild shortness of breath. She is noted to be in atrial fibrillation with a rapid ventricular response of 157 beats per minute. She gives a 1-year history of increasing fatigue, intermittent palpitations, hot flashes, and weight loss of 15 lb in the past 6 months. She denies chest pain. Examination revealed an apprehensive woman with mild proptosis and diffuse thyroid enlargement. Lungs are clear. Heart sounds are irregular and rapid. Thyroid function studies performed last week at the doctor's office show a suppressed thyroid-stimulating hormone (TSH) level of .01 with elevated free thyroxine (T4) of 60 pmol/L (normal, 9–23 pmol/L). How Should This Patient Be Managed in the Emergency Department? Management of the patient in the emergency department with thyrotoxic atrial fibrillation depends on the presence or absence of associated cardiac symptoms. A conservative management with antithyroid agents is appropriate for patients without associated cardiac complications, such as angina or heart failure. However, if the patient is symptomatic with angina or heart failure, then in addition to control of rapid heart rate, therapy to inhibit thyroid hormone release and synthesis should be initiated at the same time. The goal of therapy in the emergency department is the control of ventricular rate and relief of associated cardiac symptoms. Beta-adrenergic blocking agents may be particularly helpful because of the hypersympathetic state associated with hyperthyroidism. A cardiologist and a thyroid specialist should be involved early on in the management of such patients. PMID:16369379

The Effect of Short-term Intra-arterial Delivery of Paclitaxel on Neointimal Hyperplasia and the Local Thrombotic Environment after Angioplasty

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

Yajun, E, E-mail: eyj7681@yahoo.com.cn; He Nengshu, E-mail: eyajun@hotmail.com; Fan Hailun, E-mail: mydream510@yahoo.com.cn

2013-08-01

PurposeTo evaluate the effects of short-term intra-arterial delivery of paclitaxel on neointimal hyperplasia and the local thrombotic environment after angioplasty.MethodsAn experimental common carotid artery injury model was established in 60 rats, which were divided into experimental groups (40 rats) and controls (20 rats). Local intra-arterial administration of paclitaxel was applied at 2 doses (90 and 180 {mu}g/30 {mu}l), and the effects of short-term delivery of paclitaxel on neointimal hyperplasia and the expression of tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) were evaluated at days 15 and 30 by hematoxylin and eosin staining and immunohistochemistry.ResultsAt 15more » and 30 days after injury, neointimal thickness and area, the ratio of intimal area to medial area and the stenotic rate were all significantly decreased in the group provided the high concentrations (180 {mu}g/30 {mu}l) of paclitaxel for 2 min or 10 min and in the group provided the low concentration (90 {mu}g/30 {mu}l) of paclitaxel for 10 min (p < 0.05). At 30 days after injury, there were no significant changes in TF expression among all experimental groups. PAI-1 expression increased in the neointima of the high concentration 10 min group (p < 0.05), while t-PA expression decreased in the neointima of the high concentration 2 min group (p < 0.05).ConclusionIn the rat common carotid artery injury model, the short-term delivery of paclitaxel could effectively inhibit neointimal hyperplasia in the long term, with very little influence on the local expression of TF and PAI-1.« less

Individual Differences in Arousal and Their Relationship to Short- and Long-Term Retention. Report From the Project on Motivation and Individual Differences in Learning and Retention.

ERIC Educational Resources Information Center

Osborne, John W.; Farley, Frank H.

In two separate paired-associate learning experiments each employing 40 university students as subjects, the contribution of individual differences (IDs) in arousal to short- and long-term retention was investigated using IDs in salivary response to lemon juice stimulation as an index of arousal. Experimental subjects were pre-selected out of 184…

Evaluation of Body Weight, Body Condition, and Muscle Condition in Cats with Hyperthyroidism.

PubMed

Peterson, M E; Castellano, C A; Rishniw, M

2016-11-01

The contribution of fat loss versus muscle wasting to the loss of body weight seen in hyperthyroid cats is unknown. To investigate body weight, body condition score (BCS), and muscle condition score (MCS) in hyperthyroid cats. Four hundred sixty-two cats with untreated hyperthyroidism, 117 of which were reevaluated after treatment. Prospective cross-sectional and before-after studies. Untreated hyperthyroid cats had body composition evaluated (body weight, BCS, and MCS). A subset of these cats were reevaluated 3-12 months after treatment when euthyroid. Pretreatment body weight (median, 4.36 kg; IQR, 3.5 to 5.2 kg) was lower than premorbid weight (5.45 kg; IQR, 4.6 to 6.4 kg, P < .0001) recorded 1-2 years before diagnosis. 154 (35.3%) cats were thin or emaciated; 357 (77.3%) had loss of muscle mass. Cats showed increases in body weight (median, 4.1 kg to 5.0 kg), BCS (median, 3/5 to 3.5/5), and MCS (2/3 to 3/3) after treatment (P < .001), but mild-to-moderate muscle wasting persisted in 45% of treated cats. Most hyperthyroid cats lose body weight but maintain an ideal or overweight BCS, with only a third being underweight. As in human hyperthyroid patients, this weight loss is associated with muscle wasting, which affects >75% of hyperthyroid cats. Successful treatment leads to weight gain and increase of BCS in most cats, but almost half fail to regain normal muscle mass. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Is CHA2DS2-VASc appropriate for hyperthyroid patients with atrial fibrillation? Implications of adding a transesophageal echocardiography evaluation.

PubMed

de Souza, Marcus Vinicius Leitão; de Fátima Dos Santos Teixeira, Patricia; Vaisman, Mario; Xavier, Sergio Salles

2017-02-01

Anticoagulation remains a controversial issue among hyperthyroid patients with atrial fibrillation (AF). We aimed to evaluate the prevalence of the thrombogenic milieu (TM), detected using transesophageal echocardiography (TEE), among patients with AF related to hyperthyroidism, and to correlate these findings with the clinical embolic risk classification (CHA 2 DS 2 -VASc). CHA 2 DS 2 -VASc score, thyroid hormonal status, time since hyperthyroidism diagnosis, transthoracic echocardiography (TTE) and TEE were assessed in 47 consecutive patients aged between 18 and 65years with AF related to hyperthyroidism. The following TEE parameters defined TM: dense spontaneous echo contrast, thrombi, or left atrial appendage (LAA) blood flow velocities <0.20m/s. Non-classic TM was defined as non-dense SEC plus LAA flow velocity 0.20-0.40m/s. Pulmonary hypertension was present in 39/47 (81.4%) and TM in 22/47 (46.8%) patients. Despite a low CHA 2 DS 2 -VASc score of 0/1, 10 of 19 (52.6%) patients had a TM, whereas 16 of 28 (57.1%) patients with score ≥2 had none. The probability of having a TM did not correlate with CHA 2 DS 2 -VASc scores. On regression binary analysis, hyperthyroidism diagnosed more than 12months previous was independently associated with non-classic TM (p=0.031). Among patients younger than 65years of age with AF related to hyperthyroidism, pulmonary hypertension and TM on TEE were highly prevalent. There was no association between CHA 2 DS 2 -VASc with TEE markers of TM. Thyroid status, especially longer duration of hyperthyroidism might influence thrombogenic abnormalities. TEE adds useful information that may change antithrombotic therapy if otherwise guided solely by clinical risk classification. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Prevalence of silent vertebral fractures detected by vertebral fracture assessment in young Portuguese men with hyperthyroidism.

PubMed

Barbosa, Ana Paula; Rui Mascarenhas, Mário; Silva, Carlos Francisco; Távora, Isabel; Bicho, Manuel; do Carmo, Isabel; de Oliveira, António Gouveia

2015-02-01

Hyperthyroidism is a risk factor for reduced bone mineral density (BMD) and osteoporotic fractures. Vertebral fracture assessment (VFA) by dual-energy X-ray absorptiometry (DXA) is a radiological method of visualization of the spine, which enables patient comfort and reduced radiation exposure. This study was carried out to evaluate BMD and the prevalence of silent vertebral fractures in young men with hyperthyroidism. We conducted a cross-sectional study in a group of Portuguese men aged up to 50 years and matched in hyperthyroidism (n=24) and control (n=24) groups. A group of 48 Portuguese men aged up to 50 years was divided and matched in hyperthyroidism (n=24) and control (n=24) groups. BMD (g/cm(2)) at L1-L4, hip, radius 33%, and whole body as well as the total body masses (kg) were studied by DXA. VFA was used to detect fractures and those were classified by Genant's semiquantitative method. No patient had previously been treated for hyperthyroidism, osteoporosis, or low bone mass. Adequate statistical tests were used. The mean age, height, and total fat mass were similar in both groups (P≥0.05). The total lean body mass and the mean BMD at lumbar spine, hip, and whole body were significantly decreased in the hyperthyroidism group. In this group, there was also a trend for an increased prevalence of reduced BMD/osteoporosis and osteoporotic vertebral fractures. The results obtained using VFA technology (confirmed by X-ray) suggest that the BMD changes in young men with nontreated hyperthyroidism may lead to the development of osteoporosis and vertebral fractures. This supports the pertinence of using VFA in the routine of osteoporosis assessment to detect silent fractures precociously and consider early treatment. © 2015 European Society of Endocrinology.

Potential Involvement of P2 Receptors in the Pathological Processes of Hyperthyroidism: A Pilot Study.

PubMed

Hong, Wu; Li, Guodong; Nie, Yijun; Zou, Lifang; Zhang, Xi; Liu, Shuangmei; Li, Guilin; Xu, Hong; Zhang, Chun-Ping; Liang, Shangdong

2016-05-01

Symptoms of hyperthyroidism manifest mainly as changes in the nervous and metabolic systems. Whether P2X receptors (ionotropic ATP purinergic receptors, including P2X3 receptor and P2X7 receptor) are involved in the alterations of these disorders still remains unclear. Thus, this study aimed to assess the association of hyperthyroidism with the expression of P2X3 and P2X7 receptors and the concentrations of ATP in blood leukocytes and catecholamine. Twelve healthy subjects and twelve patients diagnosed with hyperthyroidism were recruited. Serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) levels had been detected by chemiluminescence method. Meanwhile, the catecholamine levels (including adrenaline, noradrenaline, and dopamine) in plasma, ATP level and P2X receptors (including P2X3 receptor and P2X7 receptor) in peripheral blood had been detected by high performance liquid chromatography, bioluminescence method, and reverse transcription polymerase chain reaction, respectively. Levels of epinephrine and norepinephrine were significantly higher in the hyperthyroidism group compared with the control group. The concentration of ATP in the hyperthyroidism group was significantly higher than its in the control group. The expression of P2X3 mRNA and P2X7 mRNA in hyperthyroidism group were significantly increased compared with those in control group. In a conclusion, there is a relationship between the elevated expression of P2X3 receptor and P2X7 receptor in peripheral blood leukocytes and high serum epinephrine and norepinephrine levels in hyperthyroidism patients. © 2016 by the Association of Clinical Scientists, Inc.

The significance of alteration 2-[fluorine-18]fluoro-2-deoxy-(D)-glucose uptake in the liver and skeletal muscles of patients with hyperthyroidism.

PubMed

Chen, Yen-Kung; Chen, Yen-Ling; Tsui, Chih-Cheng; Wang, Su-Chen; Cheng, Ru-Hwa

2013-10-01

Hyperthyroidism leads to an enhanced demand for glucose. The hypothesis of the study is that 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) can demonstrate the alteration of systemic glucose metabolism in hyperthyroidism patients by measuring the FDG standard uptake value (SUV) in liver and skeletal muscle. Forty-eight active hyperthyroidism patients and 30 control participants were recruited for the study. The intensity of FDG uptake in the liver and thigh muscles was graded subjectively, comprising three groups: group I, higher FDG uptake in the liver; group II, equal FDG uptake in the liver and muscles; and group III, higher FDG uptake in the muscles. Ten subjects with FDG PET scans at hyperthyroid and euthyroid status were analyzed. Serum levels of thyroxine (T4) and triiodothyronine (T3) correlated to the SUVs of the liver and muscles. Forty-one patients (41/48, 85.4%) showed symmetrically increased FDG uptake in the muscles (22 in group I, 9 in group II, and 17 in group III). Group I patients were significantly older than group II (P = .02) and group III (P = .001) patients. The correlation coefficient between the serum T3, T4, and SUV levels in the muscles was significant (r = 0.47-0.77, P < .01), particularly in liver and muscle FDG uptake between hyperthyroid and euthyroid states. In the 30 control subjects, there was normal physiological FDG uptake in the liver and muscles. In PET scans showing a pattern of decreased liver and increased skeletal muscle FDG uptake in hyperthyroidism patients, this change of FDG distribution is correspondence to the severity of hyperthyroidism status. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

How Does Subclinical Hyperthyroidism Affect Right Heart Function and Mechanics?

PubMed

Tadic, Marijana; Celic, Vera; Cuspidi, Cesare; Ilic, Sanja; Zivanovic, Vladimir; Marjanovic, Tamara

2016-02-01

Right heart function and mechanics have not been investigated in patients with subclinical hyperthyroidism. Our aim was to investigate right ventricular (RV) and right atrial (RA) function and deformation as evaluated by 3-dimensional echocardiography (3DE) and speckle-tracking 2-dimensional echocardiography (2DE) in these individuals. We included 39 untreated women with endogenous subclinical hyperthyroidism and 39 healthy women matched by age. All participants underwent laboratory analyses that included thyroid hormone levels and comprehensive 2DE and 3DE examinations. Three-dimensional echocardiographic RV volumes were significantly elevated in the patients with subclinical hyperthyroidism (P < .05), whereas the 3DE RV ejection fraction was reduced in this group, but with borderline significance. Two-dimensional echocardiographic longitudinal RV and RA strain were significantly reduced in the patients with subclinical hyperthyroidism. Two-dimensional echocardiographic RV systolic and early diastolic strain rates were reduced, whereas late diastolic strain rates were increased in the patients with subclinical hyperthyroidism. The same changes were detected in RA mechanics among the patients with subclinical hyperthyroidism. The thyrotropin (TSH) level correlated with the left ventricular mass index, transmitral early diastolic peak flow velocity (E)/late diastolic flow velocity (A) ratio, tricuspid E/A ratio, 2DE RV global strain, 2DE RA, strain, and 3DE RV end-diastolic volume. A multivariate regression analysis showed that the mitral E/A ratio, 2DE RV global strain, and 3DE RV end-diastolic volume were independently associated with the TSH level. Right ventricular and RA function as evaluated by 3DE and speckle-tracking 2DE is significantly impaired in patients with subclinical hyperthyroidism. The TSH level correlated with parameters for RV function and mechanics in the whole study population. © 2016 by the American Institute of Ultrasound in Medicine.

Hypothyroidism and hyperthyroidism and breast cancer risk: a nationwide cohort study.

PubMed

Søgaard, Mette; Farkas, Dóra Körmendiné; Ehrenstein, Vera; Jørgensen, Jens Otto Lunde; Dekkers, Olaf M; Sørensen, Henrik Toft

2016-04-01

The association between thyroid disease and breast cancer risk remains unclear. We, therefore examined the association between hypothyroidism, hyperthyroidism and breast cancer risk. This was a population-based cohort study. Using nationwide registries, we identified all women in Denmark with a first-time hospital diagnosis of hypothyroidism or hyperthyroidism, 1978-2013. We estimated the excess risk of breast cancer among patients with hypothyroidism or hyperthyroidism compared with the expected risk in the general population, using standardized incidence ratios (SIRs) as a measure of risk ratio. Breast cancer diagnoses in the first 12 months following diagnosis of thyroid disease were excluded from the calculations to avoid diagnostic work-up bias. We included 61, 873 women diagnosed with hypothyroidism and 80, 343 women diagnosed with hyperthyroidism. Median follow-up time was 4.9 years (interquartile range (IQR): 1.8-9.5 years) for hypothyroidism and 7.4 years (IQR: 3.1-13.5 years) for hyperthyroidism. Hyperthyroidism was associated with a slightly increased breast cancer risk compared with the general population (SIR: 1.11, 95% CI: 1.07-1.16), which persisted beyond 5 years of follow-up (SIR: 1.13, 95% CI: 1.08-1.19). In comparison, hypothyroidism was associated with a slightly lower risk of breast cancer (SIR: 0.94, 95% CI: 0.88-1.00). Stratification by cancer stage at diagnosis, estrogen receptor status, age, comorbidity, history of alcohol-related disease and clinical diagnoses of obesity produced little change in cancer risk. We found an increased risk of breast cancer in women with hyperthyroidism and a slightly decreased risk in women with hypothyroidism indicating an association between thyroid function level and breast cancer risk. © 2016 European Society of Endocrinology.

Effect of Feeding an Iodine-Restricted Diet in Cats with Spontaneous Hyperthyroidism.

PubMed

Hui, T Y; Bruyette, D S; Moore, G E; Scott-Moncrieff, J C

2015-01-01

Exclusive feeding of an iodine-restricted diet has been proposed as a method for controlling clinical manifestations of hyperthyroidism in hyperthyroid cats. To determine the effect of feeding an iodine-restricted diet on TT4 concentrations and clinical signs in cats with spontaneous hyperthyroidism. Forty-nine client-owned cats with spontaneous hyperthyroidism. Retrospective case series. Hyperthyroid cats were exclusively fed a commercially available iodine-restricted diet. Clinical response was assessed by change in weight and heart rate and serum TT4, blood urea nitrogen (BUN), and creatinine concentrations at various times during dietary management (21-60 days, 60-180 days). Serum TT4 normalized in 20/48 cats (42%) and 39/47 cats (83%) at 21-60 days and 61-180 days, respectively. Cats in which the TT4 concentrations were still above reference range at 21-60 days had a significantly higher starting TT4 than those that normalized their TT4 levels during the same time period (P = .038). Body weight did not significantly increase (P = .34) nor heart rate decrease (P = .64) during the study. There was a significant decrease in serum creatinine (P = .028). Cats in the low reference range for serum TT4 concentrations did not have a significant increase in body weight (P = .41) nor creatinine (P = .54) when compared to those with high reference range. Restricted-iodine diets were effective at maintaining serum TT4 concentrations within reference ranges for a majority of cats with spontaneous hyperthyroidism over 1 year, although not all clinical signs of hyperthyroidism improved. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Incidence of hyperthyroidism in Sweden.

PubMed

Abraham-Nordling, Mirna; Byström, Kristina; Törring, Ove; Lantz, Mikael; Berg, Gertrud; Calissendorff, Jan; Nyström, Helena Filipsson; Jansson, Svante; Jörneskog, Gun; Karlsson, F Anders; Nyström, Ernst; Ohrling, Hans; Orn, Thomas; Hallengren, Bengt; Wallin, Göran

2011-12-01

The incidence of hyperthyroidism has been reported in various countries to be 23-93/100,000 inhabitants per year. This extended study has evaluated the incidence for ~40% of the Swedish population of 9 million inhabitants. Sweden is considered to be iodine sufficient country. All patients including children, who were newly diagnosed with overt hyperthyroidism in the years 2003-2005, were prospectively registered in a multicenter study. The inclusion criteria are as follows: clinical symptoms and/or signs of hyperthyroidism with plasma TSH concentration below 0.2 mIE/l and increased plasma levels of free/total triiodothyronine and/or free/total thyroxine. Patients with relapse of hyperthyroidism or thyroiditis were not included. The diagnosis of Graves' disease (GD), toxic multinodular goiter (TMNG) and solitary toxic adenoma (STA), smoking, initial treatment, occurrence of thyroid-associated eye symptoms/signs, and demographic data were registered. A total of 2916 patients were diagnosed with de novo hyperthyroidism showing the total incidence of 27.6/100,000 inhabitants per year. The incidence of GD was 21.0/100,000 and toxic nodular goiter (TNG=STA+TMNG) occurred in 692 patients, corresponding to an annual incidence of 6.5/100,000. The incidence was higher in women compared with men (4.2:1). Seventy-five percent of the patients were diagnosed with GD, in whom thyroid-associated eye symptoms/signs occurred during diagnosis in every fifth patient. Geographical differences were observed. The incidence of hyperthyroidism in Sweden is in a lower range compared with international reports. Seventy-five percent of patients with hyperthyroidism had GD and 20% of them had thyroid-associated eye symptoms/signs during diagnosis. The observed geographical differences require further studies.

N-3 polyunsaturated fatty acids supplementation does not affect changes of lipid metabolism induced in rats by altered thyroid status.

PubMed

Rauchová, H; Vokurková, M; Pavelka, S; Behuliak, M; Tribulová, N; Soukup, T

2013-07-01

Epidemiological studies have demonstrated that n-3 polyunsaturated fatty acid (PUFA) consumption is associated with a reduced risk of atherosclerosis and hyperlipidemia. It is well known that lipid metabolism is also influenced by thyroid hormones. The aim of our study was to test whether n-3 PUFA supplementation (200 mg/kg of body weight/day for 6 weeks given intragastrically) would affect lipid metabolism in Lewis male rats with altered thyroid status. Euthyroid, hypothyroid, and hyperthyroid status of experimental groups was well defined by plasma levels of triiodothyronine, the activity of liver mitochondrial glycerol-3-phosphate dehydrogenase, and by relative heart weight. Fasting blood glucose levels were significantly higher in the hyperthyroid compared to the euthyroid and hypothyroid rats (5.0±0.2 vs. 3.7±0.4 and 4.4±0.2 mmol/l, respectively). In hyperthyroid animals, the concentration of plasma postprandial triglycerides was also increased compared to euthyroid and hypothyroid rats (0.9±0.1 vs. 0.5±0.1 and 0.4±0.1 mmol/l, respectively). On the other hand, hypothyroidism compared to euthyroid and hyperthyroid status was associated with elevated plasma levels of total cholesterol (2.6±0.2 vs. 1.5±0.1 and 1.6±0.1 mmol/l, respectively), LDL cholesterol (0.9±0.1 vs. 0.4±0.1 and 0.2±0.1 mmol/l, respectively) as well as HDL cholesterol (1.6±0.1 vs. 1.0±0.1 and 1.3±0.1 mmol/l, respectively). Supplementation of n-3 PUFA in the present study did not significantly modify either relative heart weight or glucose and lipid levels in any thyroid status. © Georg Thieme Verlag KG Stuttgart · New York.

An enriched stable-isotope approach to determine the gill-zinc binding properties of juvenile rainbow trout (Oncorhynchus mykiss) during acute zinc exposures in hard and soft waters

USGS Publications Warehouse

Todd, A.S.; Brinkman, S.; Wolf, R.E.; Lamothe, P.J.; Smith, K.S.; Ranville, J.F.

2009-01-01

The objective of the present study was to employ an enriched stable-isotope approach to characterize Zn uptake in the gills of rainbow trout (Oncorhynchus mykiss) during acute Zn exposures in hard water (???140 mg/L as CaCO 3) and soft water (???30 mg/L as CaCO3). Juvenile rainbow trout were acclimated to the test hardnesses and then exposed for up to 72 h in static exposures to a range of Zn concentrations in hard water (0-1,000 ??g/L) and soft water (0-250 ??g/L). To facilitate detection of new gill Zn from endogenous gill Zn, the exposure media was significantly enriched with 67Zn stable isotope (89.60% vs 4.1% natural abundance). Additionally, acute Zn toxicity thresholds (96-h median lethal concentration [LC50]) were determined experimentally through traditional, flow-through toxicity tests in hard water (580 ??g/L) and soft water (110 ??g/L). Following short-term (???3 h) exposures, significant differences in gill accumulation of Zn between hard and soft water treatments were observed at the three common concentrations (75, 150, and 250 ??g/L), with soft water gills accumulating more Zn than hard water gills. Short-term gill Zn accumulation at hard and soft water LC50s (45-min median lethal accumulation) was similar (0.27 and 0.20 ??g/g wet wt, respectively). Finally, comparison of experimental gill Zn accumulation, with accumulation predicted by the biotic ligand model, demonstrated that model output reflected short-term (<1 h) experimental gill Zn accumulation and predicted observed differences in accumulation between hard and soft water rainbow trout gills. Our results indicate that measurable differences exist in short-term gill Zn accumulation following acclimation and exposure in different water hardnesses and that short-term Zn accumulation appears to be predictive of Zn acute toxicity thresholds (96-h LC50s). ?? 2009 SETAC.

Iodine-induced hyperthyroidism--an epidemiological survey several years after institution of iodine prophylaxis in Poland.

PubMed

Lewiński, A; Szybiński, Z; Bandurska-Stankiewicz, E; Grzywa, M; Karwowska, A; Kinalska, I; Kowalska, A; Makarewicz, J; Nauman, J; Słowińska-Klencka, D; Sowiński, J; Syrenicz, A; Zonenberg, A; Huszno, B; Klencki, M

2003-01-01

In 1997, the obligatory model of iodine prophylaxis was introduced in Poland in order to correct the existing status of mild and/or moderate iodine deficiency. In order to monitor possible side-effects of increased iodine supply, studies on iodine-induced hyperthyroidism were initiated by establishing several regional registers of hyperthyroidism. In the present paper, the results of a two-year monitoring (2000-2001) have been summarized. There are no epidemiological data on hyperthyroidism prior to starting the iodine prophylaxis, but the obtained current data are comparable to observations in other countries, made after iodine supplementation. The incidence of iodine-induced hyperthyroidism did not exceed the acceptable level, thus confirming--together with previous observations on the effectiveness of iodine prophylaxis--the adequacy of applied dose of KI (30 microg/kg NaCl), used for salt iodization in Poland.

[Atypical presentation of an induced hyperthyroidism].

PubMed

Duque, María Del Pilar Velásquez; Miranda, Jaime Bernal

2013-03-01

We present the case of a person with baseline Bipolar Affective Disorder, who starts receiving medical treatment for subclinical Hypothyroidism, during this time the patient develops Hyperthyroidism. During the course of the latter, the patient started to exhibit depressed mood symptoms and worsening of her baseline disorder. Typically there are depressive symptoms in hypothyroidism and manic symptoms in hyperthyroidism, there have been a few cases of depressive symptoms (depressed mood, asthenia and apathy) reported in patients with hyperthyroidism. Up till now it's a fact that Hyperthyroidism constitutes itself as a risk factor for developing or precipitating depressive states, thus increasing hospital readmissions, and another important fact is that of manifesting or worsening affective symptoms due to the influence of thyroid hormones. We also present the well-known relationship between thyroid malfunction and affective disorders. Copyright © 2013 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Thyrotoxicosis.

PubMed

Franklyn, Jayne A; Boelaert, Kristien

2012-03-24

Thyrotoxicosis is a common disorder, especially in women. The most frequent cause is Graves' disease (autoimmune hyperthyroidism). Other important causes include toxic nodular hyperthyroidism, due to the presence of one or more autonomously functioning thyroid nodules, and thyroiditis caused by inflammation, which results in release of stored hormones. Antithyroid drugs are the usual initial treatment (thionamides such as carbimazole or its active metabolite methimazole are the drugs of choice). A prolonged course leads to remission of Graves' hyperthyroidism in about a third of cases. Because of the low remission rate in Graves' disease and the inability to cure toxic nodular hyperthyroidism with antithyroid drugs alone, radioiodine is increasingly used as first line therapy, and is the preferred choice for relapsed Graves' hyperthyroidism. Total thyroidectomy is an option in selected cases. Future efforts are likely to concentrate on novel and safe ways to modulate the underlying disease process rather than stopping excess thyroid hormone production. Copyright © 2012 Elsevier Ltd. All rights reserved.

Embolic risk in atrial fibrillation that arises from hyperthyroidism: review of the medical literature.

PubMed

Traube, Elie; Coplan, Neil L

2011-01-01

Atrial fibrillation, the most common cardiac complication of hyperthyroidism, occurs in an estimated 10% to 25% of overtly hyperthyroid patients. The prevalence of atrial fibrillation increases with age in the general population and in thyrotoxic patients. Other risk factors for atrial fibrillation in thyrotoxic patients include male sex, ischemic or valvular heart disease, and congestive heart failure. The incidence of arterial embolism or stroke in thyrotoxic atrial fibrillation is less clear. There are many reports of arterial thromboembolism associated with hyperthyroidism, including cases of young adults without coexisting risk factors other than thyrotoxic atrial fibrillation. The use of anticoagulative agents to prevent thromboembolic sequelae of thyrotoxic atrial fibrillation is controversial: National organizations provide conflicting recommendations in their practice guidelines. Herein, we review the medical literature and examine the evidence behind the recommendations in order to determine the best approach to thromboembolic prophylaxis in patients who have atrial fibrillation that is associated with hyperthyroidism.

Embolic Risk in Atrial Fibrillation that Arises from Hyperthyroidism

PubMed Central

Traube, Elie; Coplan, Neil L.

2011-01-01

Atrial fibrillation, the most common cardiac complication of hyperthyroidism, occurs in an estimated 10% to 25% of overtly hyperthyroid patients. The prevalence of atrial fibrillation increases with age in the general population and in thyrotoxic patients. Other risk factors for atrial fibrillation in thyrotoxic patients include male sex, ischemic or valvular heart disease, and congestive heart failure. The incidence of arterial embolism or stroke in thyrotoxic atrial fibrillation is less clear. There are many reports of arterial thromboembolism associated with hyperthyroidism, including cases of young adults without coexisting risk factors other than thyrotoxic atrial fibrillation. The use of anticoagulative agents to prevent thromboembolic sequelae of thyrotoxic atrial fibrillation is controversial: national organizations provide conflicting recommendations in their practice guidelines. Herein, we review the medical literature and examine the evidence behind the recommendations in order to determine the best approach to thromboembolic prophylaxis in patients who have atrial fibrillation that is associated with hyperthyroidism. PMID:21720457

A Japanese family with nonautoimmune hyperthyroidism caused by a novel heterozygous thyrotropin receptor gene mutation.

PubMed

Nakamura, Akie; Morikawa, Shuntaro; Aoyagi, Hayato; Ishizu, Katsura; Tajima, Toshihiro

2014-06-01

Hyperthyroidism caused by activating mutations of the thyrotropin receptor gene (TSHR) is rare in the pediatric population. We found a Japanese family with hyperthyroidism without autoantibody. DNA sequence analysis of TSHR was undertaken in this family. The functional consequences for the Gs-adenylyl cyclase and Gq/11-phospholipase C signaling pathways and cell surface expression of receptors were determined in vitro using transiently transfected human embryonic kidney 293 cells. We identified a heterozygous mutation (M453R) in exon 10 of TSHR. In this family, this mutation was found in all individuals who exhibited hyperthyroidism. The results showed that this mutation resulted in constitutive activation of the Gs-adenylyl cyclase system. However, this mutation also caused a reduction in the activation capacity of the Gq/11-phospholipase C pathway, compared with the wild type. We demonstrate that the M453R mutation is the cause of nonautoimmune hyperthyroidism.

Thyroid hormone-induced oxidative stress.

PubMed

Venditti, P; Di Meo, S

2006-02-01

Hypermetabolic state in hyperthyroidism is associated with tissue oxidative injury. Available data indicate that hyperthyroid tissues exhibit an increased ROS and RNS production. The increased mitochondrial ROS generation is a side effect of the enhanced level of electron carriers, by which hyperthyroid tissues increase their metabolic capacity. Investigations of antioxidant defence system have returned controversial results. Moreover, other thyroid hormone-linked biochemical changes increase tissue susceptibility to oxidative challenge, which exacerbates the injury and dysfunction they suffer under stressful conditions. Mitochondria, as a primary target for oxidative stress, might account for hyperthyroidism linked tissue dysfunction. This is consistent with the inverse relationship found between functional recovery of ischemic hyperthyroid hearts and mitochondrial oxidative damage and respiration impairment. However, thyroid hormone-activated mitochondrial mechanisms provide protection against excessive tissue dysfunction, including increased expression of uncoupling proteins, proteolytic enzymes and transcriptional coactivator PGC-1, and stimulate opening of permeability transition pores.

Paralysis as a Presenting Symptom of Hyperthyroidism in an Active Duty Soldier.

PubMed

Jennette, John; Tauferner, Dustin

2015-01-01

Thyrotoxic periodic paralysis (TPP) is an endocrine disorder presenting with proximal motor weakness, typically greatest in the lower extremities, hypokalemia, and signs or laboratory findings consistent with hyperthyroidism. The incidence of TPP is highest in Asian males. This is a case report of a 30-year-old male active duty Soldier who presented to the emergency department complaining of several recent episodes of lower extremity paralysis. The patient underwent a workup which included serum and cerebrospinal fluid studies, and was found to be hypokalemic and hyperthyroid. Following consultation with neurology, the patient was admitted to the medicine service and treated for thyrotoxic periodic paralysis with potassium replacement and treatment of his hyperthyroidism. Since achieving a euthyroid state, he has had no recurrences of TPP. This disease should be considered in patients presenting with symmetric motor weakness and hypokalemia, whether or not symptoms of hyperthyroidism are elicited during the review of systems.

Effects of experimentally induced maternal hypothyroidism and hyperthyroidism on the development of rat offspring: II-the developmental pattern of neurons in relation to oxidative stress and antioxidant defense system.

PubMed

Ahmed, O M; Ahmed, R G; El-Gareib, A W; El-Bakry, A M; Abd El-Tawab, S M

2012-10-01

Excessive concentrations of free radicals in the developing brain may lead to neurons maldevelopment and neurons damage and death. Thyroid hormones (THs) states play an important role in affecting the modulation of oxidative stress and antioxidant defense system. Thus, the objective of this study was to clarify the effect of hypothyroidism and hyperthyroidism in rat dams on the neurons development of different brain regions of their offspring at several postnatal weeks in relation to changes in the oxidative stress and antioxidant defense system. The adult female rats were administered methimazole (MMI) in drinking water (0.02% w/v) from gestation day 1 to lactation day 21 to induce hypothyroidism and exogenous thyroxine (T4) in drinking water (0.002% w/v) beside intragastric incubation of 50--200 T4 μg/kg body weight (b. wt.) to induce hyperthyroidism. In normal female rats, the sera total thyroxine (TT4) and total triiodothyronine (TT3) levels were detectably increased at day 10 post-partum than those at day 10 of pregnancy. Free thyroxine (FT4), free triiodothyronine (FT3), thyrotropin (TSH) and growth hormone (GH) concentrations in normal offspring were elevated at first, second and third postnatal weeks in an age-dependent manner. In hypothyroid group, a marked depression was observed in sera of dam TT3 and TT4 as well as offspring FT3, FT4 and GH, while there was a significant increase in TSH level with the age progress. The reverse pattern to latter state was recorded in hyperthyroid group. Concomitantly, in control offspring, the rate of neuron development in both cerebellar and cerebral cortex was increased in its density and complexity with age progress. This development may depend, largely, on THs state. Both maternal hypothyroidism and hyperthyroidism caused severe growth retardation in neurons of these regions of their offspring from the first to third weeks. Additionally, in normal offspring, seven antioxidant enzymes, four non-enzymatic antioxidants and one oxidative stress marker (lipid peroxidation, LPO) followed a synchronized course of alterations in cerebrum, cerebellum and medulla oblongata. In both thyroid states, the oxidative damage has been demonstrated by the increased LPO and inhibition of enzymatic and non-enzymatic antioxidants in most examined ages and brain regions. These disturbances in the antioxidant defense system led to deterioration in the neuronal maturation and development. In conclusion, it can be suggested that the maldevelopment of neurons and dendrites in different brain regions of offspring of hypothyroid and hyperthyroid mother rat dams may be attributed, at least in part, to the excess oxidative stress and deteriorated antioxidant defense system in such conditions. Published by Elsevier Ltd.

Hyperthyroidism as a cause of persistent vomiting.

PubMed

Hoogendoorn, E H; Cools, B M

2004-09-01

A 32-year-old woman presented with persistent vomiting, epigastric pain and weight loss. A sinus tachycardia was the clue to the diagnosis of hyperthyroidism due to Graves' disease. On treatment with propylthiouracil and a beta-blocking agent, her symptoms resolved within one day, even though her free thyroxine level was still high. Hyperthyroidism is an uncommon, but previously reported cause of persistent vomiting.

Synaptogenesis in the rat cerebellum: effects of early hypo- and hyperthyroidism.

PubMed

Nicholson, J L; Altman, J

1972-05-05

The number of synapses in the molecular layer of the rat cerebellum is reduced by early hypo-and hyperthyroidism within 30 days. Hypothyroidism retards synaptogenesis after 10 days, while hyperthyroidism accelerates synaptogenesis initially, but by 21 days the number of synapses is reduced. The sensitivity of developing synapses to thyroid hormone may permit analysis of the events triggering synaptogenesis.

Thyrotropinoma and multinodular goiter: A diagnostic challenge for hyperthyroidism.

PubMed

Aksoy, Duygu Yazgan; Gedik, Arzu; Cinar, Nese; Soylemezoglu, Figen; Berker, Mustafa; Gurlek, Omer Alper

2013-11-01

Thyroid disorders are frequently encountered. The diagnosis is straightforward unless clinical or laboratory findings are inconclusive and/or perplexing. Hyperthyroidism due to a thyrotropin-secreting pituitary adenoma rarely occurs and symptoms due to thyroid hormone excess are subtle. The presentation of the disease becomes unusual when co-secretion of other hormones with thyrotropin or concomitant thyroid parenchymal pathology exist. We present the case of a 63-year-old female patient with thyrotropinoma co-secreting growth hormone and multinodular goiter. She developed hyperthyroidism first due to thyrotropinoma and later due to a toxic nodule. Herein, we discuss the diagnostic and therapeutic challenges of hyperthyroidism with atypical presentation.

[Hyperthyroidism in molar pregnancy].

PubMed

Boufettal, H; Mahdoui, S; Noun, M; Hermas, S; Samouh, N

2014-03-01

Hyperthyroidism is a rare complication of molar pregnancy. We report a 39-year-old woman who presented a thyrotoxic syndrome accompanying a molar pregnancy. Serum thyroid hormones were elevated and returned to normal level after uterine evacuation of a molar pregnancy. The authors detail the role of thyroid stimulating property of human gonadotropin chorionic hormone and its structural changes during the gestational trophoblastic diseases. These changes give the latter the thyroid stimulating properties and signs of hyperthyroidism. Molar pregnancy may be a cause of hyperthyroidism. The diagnosis of molar pregnancy should be a mention to thyrotoxicosique syndrome in a woman of childbearing age. Copyright © 2013. Published by Elsevier SAS.

Worldwide prevalence and risk factors for feline hyperthyroidism: A review.

PubMed

McLean, Joanne L; Lobetti, Remo G; Schoeman, Johan P

2014-11-14

Since first reported in the late 1970s, there has been a steady but dramatic increase in the worldwide prevalence of hyperthyroidism in cats. It is now regarded as the most common feline endocrine disorder, with diabetes mellitus coming a close second. Not only is there evidence for an increased worldwide prevalence of feline hyperthyroidism, but also for geographical variation in the prevalence of the disease. Despite its frequency, the underlying cause(s) of this common disease is or are not known, and therefore prevention of the disease is not possible. Due to the multiple risk factors that have been described for feline hyperthyroidism, however, it is likely that more than one factor is involved in its pathogenesis. Continuous, lifelong exposure to environmental thyroid-disruptor chemicals or goitrogens in food or water, acting together or in an additive fashion, may lead to euthyroid goitre and ultimately to autonomous adenomatous hyperplasia, thyroid adenoma and hyperthyroidism. This review aims to summarise the available published evidence for the changes observed in the worldwide prevalence of the disease, as well as risk factors that may contribute to development of hyperthyroidism in susceptible cats.

The role of hyperthyroidism as the predisposing factor for superior sagittal sinus thrombosis.

PubMed

Hwang, Jong-Uk; Kwon, Ki-Young; Hur, Jin-Woo; Lee, Jong-Won; Lee, Hyun-Koo

2012-09-01

Superior sagittal sinus thrombosis (SSST) is an uncommon cause of stroke, whose symptoms and clinical course are highly variable. It is frequently associated with a variety of hypercoagulable states. Coagulation abnormalities are commonly seen in patients with hyperthyroidism. To the best of our knowledge, there are few reports on the association between hyperthyroidism and cerebral venous thrombosis. We report on a 31-year-old male patient with a six-year history of hyperthyroidism who developed seizure and mental deterioration. Findings on brain computed tomography (CT) showed multiple hemorrhages in the subcortical area of both middle frontal gyrus and cerebral digital subtraction angiography (DSA) showed irregular intra-luminal filling defects of the superior sagittal sinus. These findings were consistent with hemorrhagic transformation of SSST. Findings on clinical laboratory tests were consistent with hyperthyroidism. In addition, our patient also showed high activity of factors IX and XI. The patient received treatment with oral anticoagulant and prophylthiouracil. His symptoms showed complete improvement. A follow-up cerebral angiography four weeks after treatment showed a recanalization of the SSS. In conclusion, findings of our case indicate that hypercoagulability may contribute to development of SSST in a patient with hyperthyroidism.

Effect of prolonged exercise on oxidative damage and susceptibility to oxidants of rat tissues in severe hyperthyroidism.

PubMed

Venditti, P; De Rosa, R; Caldarone, G; Di Meo, S

2005-10-15

We investigated effects of prolonged aerobic exercise and severe hyperthyroidism on indices of oxidative damage, susceptibility to oxidants, and respiratory capacity of homogenates from rat liver, heart and skeletal muscle. Both treatments induced increases in hydroperoxide and protein-bound carbonyl levels. Moreover, the highest increases were found when hyperthyroid animals were subjected to exercise. These changes, which were associated to reduced exercise endurance capacity, were in part due to higher susceptibility to oxidants of hyperthyroid tissues. Levels of oxidative damage indices were scarcely related to changes in antioxidant enzyme activities and lipid-soluble antioxidant concentrations. However, the finding that, following exercise the scavenger levels generally decreased in liver homogenates and increased in heart and muscles ones, suggested a net shuttle of antioxidants from liver to other tissues under need. Aerobic capacity, evaluated by cytochrome oxidase activity, was not modified by exercise, which, conversely, affected the rates of oxygen consumption of hyperthyroid preparations. These results seem to confirm the higher susceptibility of hyperthyroid tissues to oxidative challenge, because the mechanisms underlying the opposite changes in respiration rates during State 4 and State 3 likely involve oxidative modifications of components of mitochondrial respiratory chain, different from cytochrome aa3.