Gonadotropin-releasing hormone agonists administration in polycystic ovary syndrome. Effects on bone mass

Women with amenorrhea and polycystic ovaries (PCO) seem to present a relative degree of protection against bone loss caused by hypoestrogenism. We treated 20 patients affected by polycystic ovary syndrome (PCOS) with a gonadotropin-releasing hormone agonist (GnRH-a) for 6 months. After treatment mean bone mineral density (BMD) significantly decreased. We concluded that patients with PCOS have to be considered at risk of developing osteopenia when treated with GnRH-a. The relative protection against osteoporosis, that is present in amenorrheic patients with PCO, might be attributed to the characteristics of amenorrhea in these patients.