Somatostatin potentiation of insulin-induced glucose uptake in normal individuals

The ability of somatostatin (SRIF) to enhance insulin-stimulated glucose uptake was evaluated during clamp studies in normal individuals and patients with non-insulin-dependent diabetes mellitus (NIDDM). The results demonstrated that glucose uptake at insulin levels of approximately 100 microU/ml was significantly greater (P less than 0.001) in normal individuals in response to insulin plus SRIF as compared with insulin alone. In contrast, SRIF did not enhance insulin-stimulated glucose uptake in patients with NIDDM. Measurements were also made of the relative ability of insulin as compared with insulin plus SRIF to suppress C-peptide and glucagon concentrations during the clamp studies. The results of these experiments showed that SRIF did not potentiate the ability of insulin to suppress C-peptide concentrations in normal subjects but did in patients with NIDDM. However, plasma glucagon levels were reduced to a greater degree when SRIF was added to insulin in both normal and diabetic individuals.