Polycystic ovary syndrome, androgen excess, and the impact on bone.

Polycystic ovary syndrome (PCOS) is a unique, natural model for the study of the influence of androgen excess on bone mass among women. Both thin and obese women develop PCOS, a presentation that allows for the evaluation of the effects of life-long obesity, alterations in body composition (central adiposity), and related metabolic abnormalities (hyperandrogenemia, hyperinsulinemia) on the skeleton. The relatively high prevalence of PCOS and its manifestation early in life render this disorder of particular importance in assessing the influence of androgens and androgen-estrogen balance on the attainment of maximal bone mass and subsequent development of osteoporosis later in life.