Insulin sensitivity index also accounting for insulin action dynamics: Importance in diabetes

The standard measures of insulin sensitivity, SI , obtained e.g. by clamp or minimal model (MM) techniques, do not account for how fast/slow insulin action reaches its plateau value. Recently, we have proposed a new dynamic insulin sensitivity index, S _I ^D, that incorporates this information. We have shown that in normal subjects S _I ^D offers, in comparison with S _I, a more comprehensive picture of insulin action on glucose metabolism. Here, we illustrate how S _I ^D is even more appropriate when studying type 2 diabetic patients whose insulin action is not only impaired in magnitude but also slow. In particular, by identifying MM from an intravenous glucose tolerance test (IVGTT) experiment in 10 diabetic subjects via a Bayesian strategy, we show that S _I ^D is not only more informative but also more precise than SI .We conclude that S _I ^D is the insulin sensitivity index of choice when studying subjects with impaired insulin action like impaired glucose tolerant or diabetics.