Prevalence and characteristics of the polycystic ovary syndrome in overweight and obese women

Background: Surprisingly, the prevalence of polycystic ovary syndrome ( PCOS) in otherwise unselected overweight or obese women is unknown, despite obesity being frequent in patients with PCOS. We conducted the present study to obtain an unbiased estimate of the prevalence of PCOS in unselected overweight and obese premenopausal women from Spain. Methods: All premenopausal women reporting to the Department of Endocrinology, Hospital Universitario Ramon y Cajal, for dietary treatment of overweight or obesity from May 2002 to December 2005 were prospectively recruited. Women referred for any other reason were automatically excluded to avoid selection bias. Diagnosis of PCOS relied on the presence of clinical and/or biochemical hyperandrogenism, oligo-ovulation, and exclusion of secondary causes. Anthropometric measurements, hirsutism scores, and androgen, gonadotropin, metabolic, and lipid profiles were obtained. Results: Of a total of 113 consecutive women recruited, 32 (28.3%) were diagnosed as having PCOS (95% confidence interval, 20.0%-36.6%). The prevalence of PCOS was not different when considering the degree of obesity. Another 3 women presented with hyperandrogenemia without oligo-ovulation, 2 had idiopathic hirsutism, 2 had chronic oligomenorrhea without clinical or biochemical hyperandrogenism, and 2 had oligomenorrhea with hyperprolactinemia, precluding the diagnosis of PCOS. The remaining 72 women (63.7%) had no evidence of hyperandrogenism or reproductive abnormalities. Conclusions: Our results demonstrate a 28.3% prevalence of PCOS in overweight and obese women from Spain, which is markedly increased compared with the 5.5% prevalence of PCOS in lean women of our country. Therefore, PCOS must be routinely ruled out in overweight and obese premenopausal women seeking advice for weight loss.