Inverse relationship of metabolic clearance rate of insulin to body mass index

Abstract

Twenty-five human subjects, whose body mass indices (BMI) ranged from 18.0 to 34.1 kg/m 2, underwent euglycemic clamps at both low (1.5 mU/kg/min) and high (10 mU/kg/min) insulin infusion rates. Mean C-peptide concentrations were ≤0.5 ng/mL at the end of each two-hour period. The metabolic clearance rates (MCR) of insulin (mL/kg/min) were significantly ( P < .001) inversely correlated with BMI at both the low ( r = −.65) and high ( r = −.71) insulin infusion rates. The negative inverse correlations with BMI remained significant at both the low ( r = −.42, P < .05) and high ( r = −.61, P < .005) insulin infusion rates if the MCR were expressed as mL/m 2/min. There were no significant correlations ( r < .21) between the MCR at either rates of insulin infusion and age or tracer insulin binding to monocytes. Decreased MCR of insulin may contribute to the hyperinsulinemia seen in obese subjects.