Association of sex hormone-binding globulin and insulin resistance among Japanese-American subjects

An association between sex hormone-binding globulin (SHBG) and insulin resi stance expressed by the homeostasis model (HOMA-R), and the significance of both variables as risk factors for the development of type 2 diabetes were investigated in 483 Japanese-American subjects. The serum SHBG level was s ignificantly higher in women (68.7 nmol/l) than in men (45.1 nmol/l). This difference was also significant independently of age, body mass index (BMI) , waist to hip ratio (WHR), and HOMA-R. When multiple regression analysis w as performed after adjustment for age and BMI, SHBG was not correlated with HOMA-R in men. In women, SHBG was not significantly correlated with HOMA-R after adjustment for age, BMI, and WHR. In a 3-year prospective analysis, HOMA-R was significantly higher in converters to type 2 diabetes than non-c onverters in both men and women which was independent of age, BMI and WHR. However, after adjusting these variables, SHBG was not a significant risk f actor either in men or women. These results indicate that SHBG might be rel ated to insulin resistance secondarily via BMI and/or WHR in both men and w omen among Japanese-Americans. HOMA-R is a useful index for both men and wo men as a risk factor of type 2 diabetes when only fasting blood samples can be obtained. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.