SHBG levels correlate with insulin resistance in postmenopausal women.

BACKGROUND: Overweight or central obesity is generally associated with increases in fasting insulin levels, insulin resistance, and glucose intolerance and has been identified as a target for new therapeutic strategies, including early change in lifestyle. Early biochemical markers for identifying at-risk patients will be useful for prevention studies. The aim of this study is to investigate whether or not SHBG level is a useful index of hyperinsulinemia and/or insulin resistance in pre- and postmenopausal obese women. At the same time, the relationship between SHBG concentrations and features of the metabolic syndrome were evaluated. METHODS: 229 women were eligible for this study. MetS was defined by using a modification of the ATP III guidelines. All patients were euthyroid, obese and overweight, 25 to 69 years of age. Subjects were divided into groups of premenopausal women (n=125) and postmenopausal women (n=104). Various fatness and fat distribution parameters, SHBG, sex hormones, FSH, LH, thyroid hormones, serum levels of fasting and postprandial glucose, lipid profile, uric acid and serum insulin, and blood pressure were measured. RESULTS: No significant difference was found in mean SHBG levels between pre- and postmenopausal obese women in this study (p=0.866). In premenopausal obese women, SHBG correlated negatively with BMI, waist circumference, fasting glucose, uric acid levels and FAI. In postmenopausal obese women, SHBG correlated negatively with fasting glucose, postprandial plasma glucose, fasting insulin, HOMA-IR and FAI and positively with HDL. SHBG had a significant inverse association with MetS parameters only in postmenopausal women, also after adjusting for BMI, age and estradiol. CONCLUSIONS: Obesity may influence the levels of endogenous sex steroid, especially after menopause. SHBG concentrations are correlated with features of the metabolic syndrome, particularly in postmenopausal obese women. These results suggest that SHBG may be an index of insulin resistance in postmenopausal obese women.

Associations between sex hormone binding globulin and metabolic syndrome parameters in premenopausal obese women.

BACKGROUND AND AIMS: The aim of this study was to determine sex hormone binding globulin (SHBG) concentrations in premenopausal obese women and to evaluate the relationships between sex hormones and features of the metabolic syndrome (MetS). SETTINGS AND DESIGN: Retrospective cross-sectional analysis was carried out on 350 obese patients aged 25 to 69 years referred to the Department of Endocrinology, Pamukkale University in 2002-2003. MATERIALS AND METHODS: 125 premenopausal euthyroid patients were eligible for this study. Subjects were divided into two groups according to the body mass index (BMI): Group I, women with BMI 2 (n = 17) and Group II,, women with BMI > or = 30 kg/m 2 (n = 108). Median SHBG concentration of Group I was 50.1 nmol/L. Group II was divided into two subgroups according to the median SHBG concentration of Group I: subjects with high SHBG levels (SHBG concentration > or = median level of the control group, i.e > or = 50.1 nmol/L) and subjects with low SHBG levels ( RESULTS: No significant difference was found in mean age between the low and high SHBG groups. The low SHBG group was significantly heavier, and with higher waist circumference than the high SHBG group. In the low SHBG group, fasting glucose, postprandial glucose and gamma glutamyl transferase (GGT) and free androgen index (FAI) were significantly higher. Lipid profile, blood pressure, uric acid, insulin and HOMA were found similar between two groups. Linear regression analyses revealed that body mass index and FAI were significant, being independent predictors of SHBG concentrations in premenopausal women. (r = 0.365, r square = 0.134). CONCLUSIONS: It is concluded that low SHBG concentrations may indicate visceral obesity and glucose intolerance in premenopausal women.

Obesity is associated with increased serum TSH level, independent of thyroid function.

OBJECTIVE: To reinvestigate the relationship between circulating TSH levels and adiposity in a cohort of obese people, who have normal thyroid function. METHODS: Retrospective cross-sectional analysis was carried out on 226 euthyroid obese or overweight female patients. Thirty-nine female lean and euthyroid subjects (BMI<25 kg/m2) were included in the study group. TSH, free thyroxine (FT4), free triiodothyronine (FT3), fasting plasma levels of insulin and glucose, homeostasis model assessment (HOMA) for insulin resistance (HOMA-IR) and insulin secretion (HOMA-b cell), body weight, height, body mass index (BMI) and waist circumference were assessed. RESULTS: Serum TSH levels were higher in the obese than in the lean subjects. In the study group (lean and obese subjects), there was a significant positive correlation between serum TSH and body weight (r=0.231, p<0.001), BMI (r=0.270, p<0.001), waist circumference (r=0.219, p=0.001), fasting insulin (r=0.201, p=0.002) and HOMA-IR (r=0.201, p=0.002); there was no correlation between serum FT4 and any of the parameters. A multivariate linear regression analysis revealed that only BMI (p=0.012, 95% CI=0.01-0.08) contributed significantly to the variance of TSH. CONCLUSIONS: This study strongly supports existing, but contradictory evidence that serum TSH levels are positively correlated with the degree of obesity and some of its metabolic consequences in overweight people with normal thyroid function.

Effect of insulin sensitivity on SHBG levels in premenopausal versus postmenopausal obese women.

This study was performed to evaluate the impact of insulin sensitivity on sex hormone-binding globulin (SHBG) and sex steroids in premenopausal and postmenopausal euthyroid obese women. A total of 227 women were eligible for this study. All were euthyroid, obese, and overweight; ages ranged from 25 to 69 years. Women were divided into premenopausal (n=151) and postmenopausal (n=76) groups. SHBG, sex steroids, thyrotropin, fasting and postprandial glucose, lipid profile, uric acid, serum insulin, and blood pressure were measured. No significant difference was found in mean SHBG levels between premenopausal and postmenopausal women. The investigators observed that during transition from premenopause to postmenopause, SHBG levels increased in insulin-sensitive women in the postmenopausal group; however, SHBG levels decreased in insulinresistant women. It was concluded that SHBG blood concentration factors are likely to change during transition from premenopause to postmenopause. The positive effect of estradiol on SHBG levels is probably stronger in premenopausal women than in postmenopausal women. It has been noted that after menopause, the impact of insulin resistance on SHBG level seems more important than the effect of estradiol.

Epidemiology and symptomatology of migraine among school children: Denizli urban area in Turkey.

OBJECTIVE: This study was aimed at finding the prevalence, associated factors, and symptomatology of migraine among 5 to 8 grades of secondary and 9 to 11 grades of high school children (age range between 11 and 18 years old) in the Denizli urban area in the western part of Turkey. BACKGROUND: Data from the developed countries indicate that migraine is the most common cause of recurrent headaches in children. Also, childhood migraine is sufficiently severe to prevent the half of the suffering children from carrying on their usual daily activities. METHODS: A cross-sectional school-based study was conducted between May 2000 and June 2000. There were 2,490 participants selected by a multistage stratified clustered sampling procedure. A validated self-administered questionnaire designed according to the International Headache Society criteria was given to the school children of age between 11 and 18 years. RESULTS: Overall migraine prevalence was 8.8%; it was 6.7% in boys and 11.0% in girls (OR: 1.7; 95% CI: 1.3 to 2.3). Among girls, the highest prevalence (17.7%) occurred at 15 years of age, but among boys, the highest prevalence (11.9%) occurred at 16 years of age. Of children with migraine, 56.5% had a positive family history, and only 29.1% visited a doctor for headache. CONCLUSION: Migraine is a common health problem among school children in Denizli urban area and it often goes underdiagnosed.