Differences in glucose metabolic enzyme activities in human adipose tissue from abdominal and gluteal regions

In order to verify whether intersite differences exist in glucose metabolism of subcutaneous human adipose tissue, basal and insulin-stimulated 14C-1-glucose incorporation into triglycerides and the activities of some enzymes of glucose disposal were tested in abdominal and gluteal adipose tissue of 31 nondiabetic obese otherwise healthy women during isocaloric diet and after 2 weeks of very-low-calorie-protein-sparing modified diet. Basal 14C-1-glucose incorporation into triglycerides was quite similar in the adipose tissue of the two sites, and it was not influenced by dietary restriction. Insulin stimulated this metabolic activity to the same extent in both sites during isocaloric diet; after hypocaloric diet this effect of insulin was slightly decreased in adipose tissue of the abdominal site and completely abolished in the gluteal site. No enzymatic activity was different between the examined subcutaneous regions during the isocaloric diet; after very-low-calorie intake, hexokinase activity decreased in both sites, once again more markedly in the gluteal one; glucose-6-P-dehydrogenase activity decreased in the adipose tissue of the gluteal region only. These data suggest that glucose metabolism of the adipose tissue of the gluteal region is particularly decreased by severe calorie restriction. Therefore, since lipolysis does not occur at a higher rate in gluteal adipose tissue during calorie restriction, this tissue seems to undergo a resting metabolic phase during hypocaloric diet.