Polycystic ovary syndrome is associated with profound insulin resistance, c
onferring an approximately 7-fold increased risk for type 2 diabetes mellit
us in premenopausal women. The mechanisms of insulin resistance in PCOS are
distinct from those in obesity and in typical type 2 diabetes mellitus. Th
ere also is evidence for pancreatic beta-cell dysfunction in PCOS that can
occur independent of obesity and glucose intolerance. Insulin resistance co
ntributes to the reproductive abnormalities of PCOS.