INS and Insulin resistance: On purpose, we excluded from our investigation women with IGT, who, for sure would present with increased insulin resistance, defective β-cell function and, therefore, reduced glucose disposition index to focus, on the contrary, on NGT women with various BMI, from normal weight to excess weight, to answer the question whether β-cell function is dysfunctional or, conversely, women with PCOS have insulin hypersecretion and to look at the impact of excessive body weight on insulin secretion.