Prevalence and predictors of risk for type 2 diabetes mellitus and impaired glucose tolerance in polycystic ovary syndrome: A prospective, controlledstudy in 254 affected women

Women with polycystic ovary syndrome (PCOS) are insulin resistant, have ins ulin secretory defects, and are at high risk for glucose intolerance. We pe rformed this study to determine the prevalence of glucose intolerance and p arameters associated with risk for this in PCOS women. Two-hundred and fift y-four PCOS women, aged 14-44 yr, were prospectively evaluated at 2 centers , 1 urban and ethnically diverse (n = 110) and 1 rural and ethnically homog eneous (n = 144). The rural PCOS women were compared to 80 control women of similar weight, ethnicity, and age. A 75-g oral glucose challenge was admi nistered after a 3-day 300-g carbohydrate diet and an overnight fast with 0 and 2 h blood samples for glucose levels. Diabetes was categorized accordi ng to WHO criteria. The prevalence of glucose intolerance was 31.1% impaire d glucose intolerance (IGT) and 1.5% diabetes. In nonobese PCOS women (body mass index, <27 kg/m(2)), 10.3% IGT and 1.5% diabetes were found. The prev alence of glucose intolerance was significantly higher in PCOS vs. control women(chi(2) = 7.0; P = 0.01; odds ratio = 2.76; 95% confidence interval = 1.23-6.57). Variables most associated with postchallenge glucose levels wer e fasting glucose levels (P < 0.0001), PCOS status (P = 0.002), waist/hip r atio (P = 0.01), and body mass index (P = 0.021). The American Diabetes Ass ociation criteria applied to fasting glucose significantly underdiagnosed d iabetes compared to the WHO criteria (3.2% vs. 7.5%; chi(2) = 4.7; P = 0.04 6; odds ratio = 2.48; 95% confidence interval = 1.01-6.69). We conclude tha t 1) PCOS women are at significantly increased risk for IGT and type 2 diab etes mellitus at all weights and at a young age; 2) these prevalence rates are similar in 2 different populations of PCOS women, suggesting that PCOS may be a more important risk factor than ethnicity or race for glucose into lerance in young women; and 3) the American Diabetes Association diabetes d iagnostic criteria failed to detect a significant number of PCOS women with diabetes by postchallenge glucose values.