Fosam A, Sikder S, Abel BS, et al. - Since the causal role of β-cell glucose sensitivity and insulin clearance in hyperinsulinemia in African Americans (AA) adults is not clear, researchers used a cross-sectional study design to compare β-cell function and insulin clearance in non-diabetic AA (n = 36) and non-Hispanic Whites (NHW) (n = 47) after a mixed meal test (MMT). From a mathematical model, insulin secretion rate (ISR), glucose sensitivity, rate sensitivity, and insulin sensitivity during MMT were derived. Findings suggested that lower insulin clearance contributes to greater levels of plasma insulin in AA. Lower levels of IDE activity in AA may explain a reduced insulin clearance. In AA, hepatic IDE activity was significantly lower.