[Association of serum sex hormone-binding globulin with type 2 diabetes]

To explore the changes of serum sex hormone-binding globulin (SHBG) and sex hormone levels in type 2 diabetes and to explore the correlation of SHBG with blood glucose, BMI, insulin sensitivity and the intervention of pioglitazone.

Eighty-five cases with type 2 diabetes (38 women) and 59 normal controls (27 women) were recruited randomly in the study. Among all patients 48 underwent pioglitazone intervention. All women were postmenopausal. Fasting serum samples were taken separately. SHBG were measured with IRMA, and estrogen (E2), testosterone (T), fasting insulin (FINS ) were detected with RIA. Body weight, fasting blood glucose (FBG), blood lipids,BMI, HOMA-IS were measured and calculated as well. LN [1/ (FBG x FINS)] was used as insulin sensitivity index (ISI).

Patient groups had lower serum SHBG levels than control groups of both sexes (women, P<0.01; men, P<0.05). T/SHBG are higher in women patient group compared with control (P<0.01). Spearman analysis showed that in women patient group,serum SHBG was correlated with FBG, FINS and ISI (r(s)=-0.372 P<0.05; 0.332 P<0.05; 0.445 P<0.01). While in men patient group,BMI was negatively correlated with serum SHBG and total T (r(s)= 0.329 P<0.05 and-0.424 P<0.01). Significant improvements of blood glucose and lipids were demonstrated in patients after 12-week pioglitazone intervention compared with baseline values, while serum SHBG, sex hormones and ISI had not significantly changed.

Reduced serum SHBG of patients with type 2 diabetes might be related to insulin resistance to some extent.