Relationship among obesity, insulin resistance, and hyperinsulinemia in the polycystic ovary syndrome.

PCOS subjects have increased magnitudes of insulin resistance when compared to ovulatory controls, when controlling for age, BMI, fasting glucose, and insulin levels. However, the magnitude of this insulin resistance in lean subjects is mild. Quantity of excess body fat, particularly subjects with a BMI of at least 30 kg/m2 is the primary predictor of insulin resistance of sufficient magnitude to put PCOS subjects at increased risk for metabolic abnormalities.