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, E 2, and sex hormone-binding globulin (SHBG) at fasting, 60 minutes, and 120 minutes after oral glucose loading. Result(s): Although androgens and E 2 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.