Insulin Resistance in Polycystic Ovarian Disease

The classic polycystic ovarian syndrome (PCOS) was originally described by Stein and Leventhal as the association of amenorrhea with polycystic ovaries and, variably, hirsutism and/or obesity. It is estimated that 5 to 10% of women of reproductive age have PCOS. Although insulin resistance is not part of the diagnostic criteria for PCOS, its importance in the pathogenesis of PCOS can not be denied. PCOS is associated with insulin resistance, independent of total or fat-free body mass. Postreceptor defects in the action of insulin have been described in PCOS that are similar to those found in obesity and type 2 diabetes. Treatment with insulin sensitizers, metformin, and thiazolidinediones (TZDs) improve both metabolic and hormonal patterns and also improve ovulation in PCOS. Recent studies have shown that women who have PCOS have higher circulating levels of inflammatory mediators such as C-reactive protein, tumor necrosis factor, tissue plasminogen activator, and plasminogen activator inhibitor-1 (PAI-1). It is possible that the beneficial effect of insulin sensitizers in PCOS may be partly due to a decrease in inflammation.