Changes in sex hormones during an oral glucose tolerance test in healthy premenopausal women.

Objective: To assess the effect of an acute elevation in circulating insulin on serum androgen levels in healthy obese women with different body-fat distributions.

Design: Controlled clinical study.

Setting: The Endocrinology Unit of an academic medical center.

Patient(s): Seventy healthy premenopausal women participated: 27 women with upper-body obesity, 22 women with lower-body obesity, and 21 normal-weight women as controls.

Intervention(s): A 75-g oral glucose tolerance test (OGTT) was performed for all participants.

Main Outcome Measure(s): Anthropometry and serum concentrations of glucose, insulin, free T, DHEAS, androstenedione, E2, and sex hormone-binding globulin (SHBG) at fasting, 60 minutes, and 120 minutes after oral glucose loading.

Result(s): Although androgens and E2 levels in all three groups declined modestly, there were no statistically significant differences in response of the sex hormones to an OGTT in the two obese groups and normal-weight women. No correlation was found between changes in sex-hormone levels during an OGTT and insulin rise. Increased body mass index and more pronounced abdominal fat localization resulted in basal hyperinsulinemia, markedly exaggerated glucose-induced insulin levels, and hyperandrogenism, as was evident by significantly elevated free T and low SHBG serum levels.

Conclusion(s): There were no statistically significant differences in androgen response to acute hyperinsulinemia during an OGTT between obese women with different regional fat distributions and lean controls.