Prevalence of insulin resistance and prediction of glucose intolerance and type 2 diabetes mellitus in women with polycystic ovary syndrome

Background: Diabetes mellitus type 2 (DM2) affects 10% of women with polycystic ovary syndrome (PCOS). We evaluated the sensitivity and specificity of clinical and fasting biochemical parameters in screening for impaired glucose tolerance (IGT) and DM2. Methods: Women with PCOS [n = 244, age 27.4 +/- 7.5 years, body mass index (BMI) 27.5 +/- 6.9 k g/m(2)] and healthy women (n=57, age 26.8 +/- 5.8 years, BMI 21.3 +/- 2.1 k g/m(2)) underwent basal blood sampling and an oral glucose tolerance test (oGTT). Results: Insulin resistance was identified in 40.2% of PCOS women. Impaired fasting glucose (5.6-6.9 mmol/L) was found in 30 subjects (12.3%), but the oGTT revealed IGT in only six of these cases and DM2 in one subject. IGT was found in 23 (9.4%) and DM2 in four (1.6%) of the women with PCOS. The conventional upper limits for total cholesterol, triglycerides, systolic and diastolic blood pressure and fasting glucose revealed low sensitivity for the identification of impaired glucose metabolism. Conclusions: No single parameter nor any combination of them showed an accuracy sufficient for screening of IGT or DM2 in PCOS patients. All PCOS patients should be screened using an oGTT to identify disturbances in glucose metabolism.