The Effect of Metformin on Androgen Production in Diabetic Women with Non-classic Congenital Adrenal Hyperplasia

Non-classic congenital adrenal hyperplasia (NC-CAH), one of the most common genetic disorders, is often associated with the clinical features of hyperandrogenism. This study included 19 women with recently diagnosed and previously untreated type 2 diabetes, 8 of whom suffered from NC-CAH, treated with metformin (2.55-3.0 g daily). Glucose homeostasis markers, plasma lipids, as well as plasma levels of 17-hydroxyprogesterone, androgens and gonadotropins were assessed at baseline and after 6 months of therapy. In both groups of patients, metformin reduced fasting plasma glucose, insulin resistance, triglycerides and glycated hemoglobin. Moreover, in patients with NC-CAH, but not in women with normal adrenal function, metformin decreased plasma levels of 17-hydroxyprogesterone, total and free testosterone, androstenedione and dehydroepiandrosterone sulphate. The obtained results suggest that metformin partially normalizes androgen production in symptomatic patients with NC-CAH.