The relationship between visfatin and serum concentrations of C-reactive protein, interleukin 6 in patients with metabolic syndrome.

AIM: To evaluate the relationship between inflammatory and pro inflammatory markers, with obesity and visceral adiposity in male subjects with or without metabolic syndrome (MS). SUBJECTS AND METHODS: A total of 37 patients with MS and 37 age matched controls were included (mean age 46.35 ± 1.6 years). MS was defined by the criteria of the international diabetes federation 2005. Anthropometric and biochemical profiles, including high-sensitivity C-reactive protein (Hs-CRP), visfatin and interleukin 6 (IL-6), were measured. Data were compared between groups by using t test. Pearson's correlation was used to evaluate the relationship between variables. P values less than 0.05 were considered as statistically significant. RESULTS: In patients with MS, CRP and IL-6 were significantly correlated with body mass index, waist circumference and waist to hip ratio. Visfatin levels were significantly lower in patients with MS compared to controls (log visfatin: 1.74 ± 0.27 vs. 1.86 ± 0.13 ng/ml, MS vs. control group respectively). We cannot find any significant correlation between visfatin, CRP and IL-6. Also there were no correlation between visfatin levels and any anthropometric parameters in patients with MS or control groups. CONCLUSION: Serum visfatin was lower in patients with MS. Therefore it seems that visfatin could not be considered as a pro inflammatory adipocytokine in MS. The positive associations of obesity and visceral adiposity with elevated CRP and IL-6 levels suggest the importance of reducing visceral adiposity to prevent the risk of coronary disease.

The effect of thyroidectomy and propylthiouracil-induced hypothyroidism on insulin secretion in male rats.

Data available on thyroid dysfunction and insulin secretion are inconsistent. The aim of this study was to assess the effect of hypothyroidism on insulin secretion, in vivo and in vitro, in rats. Adult Wistar male rats were divided into 4 groups, the control, the propylthiouracyl (PTU)-treated hypothyroid, the surgically thyroidectomized, and the sham-operated thyroidectomized. After 5 weeks, intravenous glucose tolerance test (IVGTT) was performed and 3 weeks later pancreatic islets were isolated to assess glucose induced insulin secretion and insulin content. Fasting serum glucose and insulin levels did not differ between the groups, but serum glucose concentration during IVGTT in the PTU-induced hypothyroid group was significantly higher as compared to controls, throughout 5-60 min. The serum glucose concentration during IVGTT in the thyroidectomized rats was also significantly higher than in the sham-operated ones, except at 10 and 60 min. The area under the curve of the serum insulin was significantly lower during IVGTT in the PTU-treated (10,010 ± 1,380 pmol/l/60 min) and thyroidectomized (13,930 ± 2,786) groups vs. their comparable groups (19,150 ± 2,110), p<0.01 and (20,650 ± 1,601), p<0.05, respectively. In the PTU-treated, but not in thyroidectomized animals, insulin secretion in response to glucose 8.3 and 16.7 mM was significantly lower than their comparable group. The results show that PTU- and thyroidectomy-induced hypothyroidism leads to impaired glucose tolerance due to reduced glucose stimulated insulin secretion. Islets insulin secretion is positively correlated with serum T3 and T4 concentrations.

Effect of neonatal hypothyroidism on carbohydrate metabolism, insulin secretion, and pancreatic islets morphology of adult male offspring in rats.

BACKGROUND: Neonatal hypothyroidism has serious effects on growth, development, and metabolism. AIM: This study aims to investigate the effects of the neonatal hypothyroidism on carbohydrate metabolism, islet insulin secretion and morphology of the pancreatic islets in adult male offspring. MATERIALS/SUBJECTS AND METHODS: Lactating mothers of Wistar rats consumed 0.02% solution of 6-propyl-2-thiouracil during the weaning period (neonatal hypothyroid group), while mothers of the control group drank merely tap water. Body weight and survival of pups were followed up. Intravenous glucose tolerance test was performed in adult male offspring and 5-6 weeks later, glucose-stimulated insulin secretion (GSIS) was evaluated. RESULTS: During the glucose tolerance test, plasma glucose level of the neonatal hypothyroid group (13.18 ± 0.59 mmol/l) was significantly higher at 5 min compared to the control group (11.54 ± 0.47 mmol/l), whereas plasma insulin concentrations and GSIS of the groups was not significantly different. Homeostasis model assessment of insulin resistance of adult male offspring of the hypothyroid group (9.1 ± 1.0) was significantly higher as compared to the control group (4.5 ± 0.6). Area (14,613.0 ± 2646.3 µm2) and the diameter of the islets (147 ± 3.0 µm) of the neonatal hypothyroid group were significantly lower, as compared to the control group (32,886.3 ± 4690.3 and 206.6 ± 5.9 µm2 and µm, respectively). CONCLUSION: Neonatal hypothyroidism can alter carbohydrate metabolism in euthyroid adult offspring, which may increase susceptibility to the development of glucose intolerance and occurrence of Type 2 diabetes later in life.

Association between serum nitric oxide metabolites and hypertension in a general population.

AIM: Endothelial dysfunction and impaired release of endothelial nitric oxide occurs in hypertension. The aim of this study was to determine the relation between nitric oxide metabolites (NOx) concentrations and blood pressure levels in a general population. METHODS: In a cross-sectional study, NO(x)was measured in 2,968 adult subjects, randomly selected from a population-based study, using the Griess method. Subjects were classified into normal, prehypertension, stage 1 hypertension and stage two hypertension groups, according to the seventh report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure. RESULTS: Serum NO(x)values were negatively correlated with systolic blood pressure ≥160 mm Hg in men (r=-0.523, P=0.002). Serum NOx was higher in men with stage 1 hypertension while those with stage 2 hypertension had significantly lower NO(x) levels. In men, medication increased serum NO(x) concentration in both stages of hypertension but in women, a significant increase was observed only in stage 1 hypertension. CONCLUSION: Serum NO(x) concentrations decreased in untreated stage 2 hypertension and increased in stage 1 hypertension in men, findings that suggest NOx measurement might be helpful for assessing endothelial (dys) function in male hypertensive subjects.

The effect of maternal hypothyroidism on the carbohydrate metabolism and insulin secretion of isolated islets in adult male offspring of rats.

Thyroid hormones have crucial developmental effect during fetal life. This study investigates the effects of maternal hypothyroidism on the carbohydrate metabolism and insulin secretion capacity of islets of the adult male offspring of rats. One group of pregnant mothers (fetal hypothyroid) of Wistar rats drank water containing 0.02% of 6-propyl-2-thiouracil during pregnancy, while the control group consumed only tap water. After delivery, survival and weight of the neonates from both groups were followed. In adult male offspring, the intravenous glucose tolerance test was performed and 5-6 weeks later, glucose-stimulated insulin secretion of isolated islets was assessed. Plasma glucose concentration of the fetal hypothyroid group during intravenous glucose tolerance test was significantly higher (p=0.003) at 5-20 min as compared to the control group, whereas plasma insulin concentration was significantly lower (p=0.012) at 5-20 min. Insulin secretion of the isolated islets stimulated with 16 mM glucose of the offspring in the fetal hypothyroid group (376.2 ± 57.1 pmol/islet/60 min) was significantly lower (p=0.02) as compared to the control group (618.1 ± 85.2). Although adult offspring born from hypothyroid mothers were euthyroid, their glucose tolerance and glucose stimulated insulin secretion of islets were altered, which may eventually contribute to the development of diabetes.