Assessment of insulin resistance in lean women with polycystic ovary syndrome.

Objective To develop and validate a specific simple measure of insulin sensitivity using oral glucose tolerance test (OGTT) values for lean polycystic ovary syndrome (PCOS) women. Design Retrospective study. Setting Gynecologic Outpatient Clinic of University Hospital, affiliated with Unit of Gynecologic Endocrinology. Patient(s) Totals of 201 lean and 198 overweight/obese (ov-ob) nondiabetic PCOS patients were retrospectively selected. Intervention(s) None. Main Outcome Measure(s) All patients underwent OGTT, euglycemic-hyperinsulinemic clamp, and androgenic and biochemical assays. The predictive performance of each insulin resistance (IR) index was analyzed with the use of receiver operating characteristic (ROC) curves. Result(s) Higher correlation coefficients with clamp studies were obtained with the Belfiore Area ( R S = 0.579) and the homeostasis-model assessment (HOMA)-M 120 ( R S  = −0.576) in lean PCOS patients and with the Sib ( R S = 0.697) in ov-ob PCOS patients. The best predictive index of IR in lean PCOS was a HOMA-M 120 value of ≥12.8 or more (area under the ROC curve [AUC] 92.4%). In the ov-ob PCOS population, the best predictive performance was obtained by a Sib of ≤10.2 or less (AUC 85.7%). Conclusion(s) IR should be assessed in all PCOS women, both lean and ov-ob subjects. The HOMA-M 120 resulted as a very simple tool, validated specifically for the lean PCOS woman whose cardiometabolic impairment is more frequently misunderstood.