HOMA-IR(μU/ml∙mg/dl)=fasting insulin(μU/ml)∙(fasting glucose (mg/dl))/405 Peripheral insulin sensitivity was assessed by the Oral Glucose Insulin Sensitivity (OGIS) model. OGIS is an index of insulin sensitivity calculated in this case from the 3 hours OGTT and it is an estimate of the glucose clearance during a hyperinsulinemic euglycemic glucose clamp expressed in ml/min per square meter of body surface area.