The Normal 93: Linking the β-Cell and Insulin Sensitivity: Revisiting a 1993 Diabetes Classic by Kahn et al

In this month's Classics in Diabetes featured article, published in Diabetes in 1993, the description by Kahn et al. of the relationship between insulin secretion and insulin sensitivity in 93 healthy adults without diabetes provided a model for the regulation of glucose tolerance that continues to be used today. In the study, data from a large sample of individuals studied with intravenous glucose tolerance tests demonstrated that in those with normal glucose tolerance, insulin secretion and sensitivity were related by a hyperbolic curve. This relationship supports adaptability between these parameters that maintains a constant amount of insulin action, and glycemia conforming to the normal range. These findings have led to the general view that type 2 diabetes mellitus is fundamentally a failure of β-cells to adequately supply tissues such as the liver, skeletal muscle, and adipose with insulin. This simple conception remains useful for explaining diabetes pathogenesis and interpreting experimental data some 30 years after publication, with impact meriting recognition as a Diabetes classic.