Effect of Metformin on Sensitivity of the GnRH Pulse Generator to Suppression by Estradiol and Progesterone

Overview

Many, but not all, girls with high levels of the male hormone testosterone go on to develop polycystic ovary syndrome (PCOS) as adults. Women with PCOS often have irregular menstrual periods, excess facial and body hair, and weight gain. PCOS is also a leading cause of difficulty becoming pregnant. The investigators do not understand why some girls with high hormones develop PCOS and others do not. In a previous study by our group, some girls with high levels of male hormones had abnormalities in the secretion of another hormone, called luteinizing hormone (LH), that are often seen in women with PCOS. However, another group had normal LH secretion. The girls with the abnormal LH secretion had higher levels of another hormone, called insulin, than the girls with normal LH secretion. The investigators will test whether metformin, an insulin-sensitizing agent, changes the effects of high male hormone levels in adolescent girls, specifically by looking at their LH secretion response following metformin treatment.

A better understanding of the factors that make adolescent girls more or less susceptible to the adverse neuroendocrine effects of elevated androgens will hopefully lead to improved prevention and treatment strategies for PCOS. In this study, we propose to explore the role of hyperinsulinemia on neuroendocrine function in hyperandrogenic adolescent girls by assessing the effect of the insulin sensitizer Metformin on hypothalamic progesterone sensitivity. Other differences between the progesterone sensitive and progesterone insensitive subgroups, including racial and ethnic differences between the two populations and a trend towards older gynecologic age in the progesterone insensitive population, are being pursued through other ongoing studies (IRB-HSR# 8588 and 12160).