Forty-five NGT obese subjects were submitted to OGTT with IRI and CPR determinations and to euglycemic hyperinsulinemic clamp, and divided into two groups: A) those with return of insulinemia toward basal values, and B) those with residual hyperinsulinism, in order to evaluate possible differences in insulin secretion and/or insulin action among them. Our data show the younger age of those with residual hyperinsulinism, that also seems related to insulin secretion, represented by IRI and CPR basal values, but not to insulin resistance parameters.