Abstract

BACKGROUND
Sex hormone-binding globulin (SHBG) has been known to be associated with obesity, central fat accumulation and insulin resistance and thought to be a indirect marker for androgenicity in women. The relationships between circulating dehydroepiandrosterone(DHEA). dehydroepiandrosterone sulfate(DHEA-S) levels and body fat accumulation are still controversial. We conducted a cross-sectional study to eva]uate the relationships between serum levels of SHBG, DHEA-S, body fat distribution pattern and insulin sensitivity in women. METHODS: We tested 57 women(age 30~65yr; BMI 18.5~32.8kg/m, 45 premenopausal on the 5~10 day of the menstrual cycle, 12 postmenopausal who were not using hormone replacement therapy) with varying degree of glucose tolerance(32 normal glucose tolerance(NGT), 17 impaired glucose tolerance(IGT) and 8 newly diagnosed diabetes). lnsulin sensitivity was measured as minimal model derived sensitivity index(S) using insulin modified IV glucose tolerance test and fasting serum levels of SHBG and DHEA-S were measured by RIA. Body fat distribution pattern was assessed by waist to hip ratio(WHR),% body fat measured by bioelectrical impedance analyzer, subcutaneous fat area(SFA), visceral fat area(VFA) and VFA to SFA ratio(VSR) at the level of umbilicus using the computed tomography. RESULTS: 1) Measured SHBG and DHEA-S levels were not significantly different among subjects with NGT, IGT and diabetes. 2) SHBG was inversely associated with age, BMI, WHR, diastolic blood pressure, VFA, SFA, VSR,% body fat, fasting insulin and positively associated with S, whereas DHEA-S did not show any significant correlation with above variables except diastolic blood pressure. 3) SHBG level was significantly lower(p<0.05) and DHEA-S level was insignificantly lower (p=0.05) in postmenopausal women than in premenopausal women but the significance disappeared after adjustment for age, BMI, WHR and% body fat. 4) BMI was independently and negatively related to S, WHR and fasting insulin to SHBG by multiple regression analysis. CONCLUSION: We confirmed that SHBG was independently associated with central obesity and fasting hyperinsulinemia. However, S was independently associated with BMI only. It suggested that hyperinsulinemia in insulin resistance might cause the decreased level of SHBG even thaugh the directionality of the association was uncertain because of a cross-sectional nature of this study.

• Keywords: SHBG;DHEA-S;Insulin sensitivity;Body fat distribution pattern;