Relationship of the metabolic syndrome and obesity to polycystic ovary syndrome: a controlled, population-based study.

OBJECTIVE: Although hyperinsulinemia seems to be an essential feature of polycystic ovary syndrome, the frequency of gynecologic disorders related to polycystic ovary syndrome at a population level in women with evident metabolic syndrome is not known. STUDY DESIGN: We conducted a cross-sectional, population-based study. Participants (N = 204) were recruited from a random sample of women in 5 age groups (range, 35-54 years) living in a defined area. Metabolic syndrome was considered to be present if 3 of the following 8 criteria were fulfilled: (1) first-degree relative with type II diabetes, (2) body mass index > or = 30 kg/m2, (3) waist/hip ratio > or = 0.88, (4) blood pressure > or = 160/95 mm Hg or drug treatment for hypertension, (5) fasting serum triglyceride level > or = 1.70 mmol/L, (6) high-density lipoprotein cholesterol value < 1.20 mmol/L, (7) abnormal glucose metabolism, and (8) fasting insulin value > or = 13.0 mU/L. The frequency of metabolic syndrome was 106 (19.5%) of 543 cases. The control group consisted of 62 overweight women without central obesity or metabolic syndrome and 53 healthy lean women (body mass index < 27 kg/m2. RESULTS: The group with metabolic syndrome differed from the other women according to most of the selection criteria and also had the highest free testosterone concentration. However, there were no differences between the groups regarding parity, infertility problems, or obstetric outcome. However, oligomenorrhea appeared to be more common in women with metabolic syndrome, especially in those with more severe symptoms (46.2%), than in obese (25.4%) and lean (15.1%) control subjects. Polycystic-like ovaries were detected by vaginal ultrasonography with similar frequency (13.1%, 15.3%, and 13.2% in women with metabolic syndrome, obese women, and lean women, respectively). CONCLUSIONS: Surprisingly few women with metabolic syndrome had symptoms suggestive of polycystic ovary syndrome, in comparison with obese and lean women. Our results suggest that at the population level polycystic ovary syndrome only accounts for a distinct subgroup of a much wider problem, metabolic syndrome.