Insulin Sensitivity Suppressing Endogenous Glucose Production Assessed by a 2-Compartment Model

Abstract

Frequently sampled insulin-modified intravenous glucose tolerance tests with stable-labeled glucose were conducted on 23 individuals with normal glucose tolerance.The time course of labeled glucose was analyzed using a 2-compartment minimal model (Am J Physiol 277: E 481-, 1999) to evaluate insulin sensitivity specific to glucose uptake (SI²*) and kinetic parameters for exchanging glucose between the 2 compartments (k₁₂, k₂₁ and V₁).From these parameters and the time course of glucose until its nadir, insulin sensitivity (total insulin sensitivity: SI²) responsible for stimulating glucose uptake and suppressing endogenous glucose output was calculated by the 2-compartment minimalmodel.Consistent with theoretical considerations, SI² greater than SI²* in all subjects.The ability of insulin to suppress endogenous glucose production (hepaticinsulin sensitivity: HSI²) was defined as the difference between SI² and SI²* and consisted 40% of total insulin sensitivity.