Gender differences in the relationship between insulin-mediated glucose utilization and sex hormones in young African-Americans.

OBJECTIVE

To determine whether there are gender differences in insulin-mediated glucose utilization and if sex hormones correlate with measures of insulin sensitivity in young adult African-Americans.

DESIGN

Cross-sectional case (women)-control (men) study.

PARTICIPANTS

African-American men and women aged 27 to 35 years. Excluded were known diabetics, individuals on antihypertensive therapy, and women taking exogenous estrogen preparations.

METHODS

Procedures included anthropometric and blood pressure measurement, oral glucose tolerance test, sex hormone assay, and euglycemic hyperinsulinemic clamp. Procedures for data analysis included two-way analysis of variance and Pearson's correlation coefficients.

RESULTS

Data were analyzed on 104 men and 142 women with a mean age of 31.5 years. Insulin sensitivity was lower in women than in men. When insulin-mediated glucose utilization was corrected for body fat, there was no gender difference in insulin sensitivity. There was a significant correlation of androgen status with insulin sensitivity, but this relationship was divergent between men and women. For men, the correlation between insulin sensitivity and free testosterone was positive (r = .36, P < .001). For women, this correlation was negative (r = -.28, P = .001).

CONCLUSION

These data on young African-Americans demonstrate no gender differences in insulin sensitivity when glucose utilization is corrected for adipose mass. Androgen status is significantly linked with insulin sensitivity, but the relationship is divergent in men and women. Insulin resistance in young women is strongly associated with relative androgen excess, which may augment the risk for cardiovascular disease.