Evidence for Distinctive and Intrinsic Defects in Insulin Action in Polycystic Ovary Syndrome

Women with PCO have a unique but poorly characterized disorder of insulin action. Obese ( n = 16) and nonobese ( n = 14) PCO women and age- and weight-matched normal, nondiabetic ovulatory women (obese, n = 15; nonobese, n = 17) had insulin action determined in vivo with sequential multiple insulin dose euglycemic clamps and in isolated abdominal adipocytes to clarify the mechanisms of insulin resistance. PCO resulted in significant increases in the ED 50 insulin for glucose utilization in vivo ( P P P P 50 insulin, P P V max P 50 insulin for suppression of HGP was increased only in obese PCO women ( P