Insulin Response in Relation to Insulin Sensitivity: An Appropriate β-Cell Response in Black South African Women: Response to Joffe and Distiller

We are in agreement with Joffe and Distiller (1) that the pathogenesis of type 2 diabetes in black South Africans cannot be inferred from limited studies of insulin responses in small cross-sectional studies. In our cross-sectional study, we only examined black and white premenopausal normoglycemic South African women to determine whether there were differences in insulin sensitivity and β-cell function in the absence of the potential confounding effects of hyperglycemia. We thus did not extrapolate our findings to diabetic individuals, but rather recommended “longitudinal studies to determine whether the β-cell will continue to compensate in the black women with increasing age or whether it will fail over time leading to disturbances in glucose tolerance” (2).