Hyperinsulinemia and enlarged adipocytes in patients with endogenous hyperlipoproteinemia without obesity or diabetes mellitus.

Studies of adipocyte metabolism were performed in twelve male subjects with normal plasma lipids and eleven male patients with Type IV or Type V hyperlipoproteinemia. Patients with obesity or diabetes mellitus were excluded from the study. Although all patients had normal glucose tolerance tests, the blood glucose levels during these tests were higher in the hyperlipoproteinemic patients than in the normal control subjects and the plasma insulin responses were even more strikingly elevated in the hyperlipemic group. Adipocytes isolated from hypertriglyceridemic subjects were larger than those obtained from normal individuals and exhibited increased activities of both Type I and Type II hexokinase and increased rates of glucose oxidation and lipogenesis from glucose. Cell size, hexokinase isoenzyme activities and rates of lipogenesis from glucose were all strongly correlated with each other, but none of these measurements were correlated with glucose oxidation. It is not known how the adipocyte abnormalities are related to the lipid transport disorder.