Glucose-Mediated Glucose Dynamics after Intravenous Glucose Injection in Insulin-Dependent Diabetic Subjects

Abstract

In this study, intravenous glucose tolerance tests were performed in a group of insulin-dependent diabetic subjects who had no residual insulin secretion. Under these circumstances, it was possible to measure directly glucose-mediated glucose disappearance in response to intravenous glucose administration. Two models, the minimal model of unlabeled glucose kinetics and a linear two-compartment model, were identified from the observed plasma glucose data. The performances of those two models were compared on the basis of goodness-of-fit criteria and of practical identifiability. The results suggest the inadequacy of the minimal model to describe glucose-mediated glucose disappearance after glucose administration. In contrast, the considered two-compartment model was able to account for the observed glucose-mediated glucose dynamics. The two-compartment model exhibited a better performance, because it considers not only the effect of glucose per se on glucose production and glucose uptake, but also the glucose exchange dynamics between vascular and extravascular spaces.