SEX HORMONE-BINDING GLOBULIN AND INSULIN-RESISTANCE IN AFRICAN-AMERICAN WOMEN

Sex hormone-binding globulin (SHBG) binds testosterone, determining th e level of free, biologically active hormone, acid is a sensitive indi cator of androgen status in women. SHBG is strongly correlated with hi gh-density lipoprotein (HDL), central obesity, and insulin sensitivity in Caucasian and Mexican-American women, thereby acting as a biologic marker for cardiovascular disease risk. The purpose of this study was to determine if SHBG was a significant correlate of metabolic cardiov ascular risk factors in African-American women. Eighty-one nondiabetic , normotensive African-American women were enrolled (mean age, 30 year s). After excluding women on oral contraceptives (n = 19), 62 women we re examined during the follicular phase of the menstrual cycle. All su bjects underwent an oral glucose tolerance test (OGTT) and a euglycemi c-hyperinsulinemic insulin clamp, and the lipid and sex hormone levels were measured. Correlation analyses showed a significant correlation between SHBG and the following variables in women: central obesity, bo dy mass index (BMI), HDL cholesterol, apolipoprotein B (apoB), insulin sensitivity adjusted for lean mass (M'), and the sum of insulin durin g the OGTT. The strongest correlates of SHBG in women were measures of insulin resistance (r = .421, P < .001), SHBG appears to be a biologi c marker for insulin resistance, which is linked to cardiovascular ris k, in African-American women. Copyright (C) 1998 by W.B. Saunders Comp any.