Lipid metabolism in lipoatrophic diabetes

Some aspects of lipid metabolism were studied in 4 patients with a congenital lipoatrophic diabetes (LAD) associated to a type IV hyperlipoproteinemia. The analysis of lipoprotein composition, expressed as mg/dl, demonstrates a significant increase of VLDL mass and a significant reduction of HDL mass. The analysis of lipoprotein composition, expressed as per cent of total mass demonstrates an increase of the triglyceride content in all fractions and a significant reduction of the cholesterol and phospholipid content in HDL2 particles. Apo C-II, C-III0, C-III1 and C-III2 levels in lipoprotein fractions were normal in LAD patients. Lipoprotein lipase activity in omental adipose tissue, collected during laparoscopy in one patient was undetectable. The serum of this patient did not fully activate the lipoprotein lipase eluted from normal adipose tissue. In all patients the adipose tissue lipoprotein lipase activity in post-heparin plasma was blunted or near absent. Thus a reduced peripheral clearance of triglyceride-rich lipoprotein could be an important determinant of lipoprotein abnormalities in lipoatrophic diabetes.