Glucose, insulin, and somatostatin infusion for the determination of insulin sensitivity in vivo

Abstract

Shen et al. 1 and Reaven et al. 2 have recently reported increased insulin resistance in adult-onset type diabetes based on the steady state plasma glucose (SSPG) method. In this method, epinephrine and propranolol were used to suppress endogenous insulin secretion. Epinephrine and propranolol themselves elevate SSPG levels. 3 Also, plasma levels of growth hormone (HGH) and glucagon may not be suppressed under these conditions, since paradoxical rises or less suppressibility of HGH 4 and glucagon 5 following glucose loads have been reported in diabetic subjects. We have therefore used somatostatin, which has been shown to have no direct effect on glucose and lipid metabolism, 6 to suppress endogenous secretion of insulin, glucagon, and HGH. Using the newly revised method, we have assessed insulin sensitivity in diabetics treated with diet alone, sulfonylureas, or insulin, and in obese nondiabetic subjects with hyperinsulinism.