Screening for abnormal glucose tolerance in adolescents with polycystic ovary syndrome

Insulin resistance is common in adults with polycystic ovary syndrome (PCOS). Although recent data demonstrate that insulin resistance is present in the early stages of PCOS, the prevalence of insulin resistance in adolescents with PCOS has not been determined. Likewise, the prevalence of impaired glucose tolerance (IGT) or type 2 diabetes mellitus (DM) in adolescent cohorts has not been established. In this study we sought to obtain preliminary data regarding the prevalence of IGT and DM in adolescents with PCOS and to assess the ability of screening tests to predict these abnormalities within this population. Twenty-seven adolescents with PCOS underwent oral glucose tolerance tests. Plasma glucose and insulin levels were obtained at baseline, and glucose was measured 2 h after a 75-g glucose challenge. The 2-h plasma glucose level was used to categorize subjects as having IGT or the provisional diagnosis of DM. Eight of our 27 subjects had IGT, and 1 had previously undiagnosed DM. These abnormalities were seen among lean and obese subjects. Fasting plasma glucose levels and simple measures of insulin resistance were suboptimal predictors of IGT and DM within our cohort. As in adults, our results indicate that adolescents with PCOS are at increased risk for IGT and DM and that the 2-h plasma glucose level after an oral glucose challenge appears to be the most reliable screening test for these abnormalities. Our results need to be corroborated by future studies that determine the prevalence of abnormalities in glucose tolerance among large populations of adolescents, both with and without PCOS. However, as DM may be preventable by lifestyle modifications, we would recommend that adolescents with PCOS undergo periodic screening for abnormal glucose tolerance using 2-h postchallenge plasma glucose levels.