Post-heparin hepatic and lipoprotein lipase activities in nephrotic syndrome.

Lipid metabolism was studied in 18 patients with nephrotic syndrome due to various glomerulonephritides. Nephrotic patients had hypercholesterolemia with or without hypertriglyceridemia. The mean serum high-density lipoprotein cholesterol concentration was not significantly reduced in nephrotic patients. Hepatic lipase and lipoprotein lipase activities were measured selectively in post-heparin plasma from all 18 patients using a substrate-specific method. The mean lipoprotein lipase activity in nephrotic patients was markedly reduced while the mean hepatic lipase activity was not significantly different from that of controls. Lipoprotein lipase activities correlated inversely with serum triglyceride concentrations, but positively with in vivo post-heparin fractional clearance rates of Intralipid and with serum high-density lipoprotein concentrations. Nephrotic serum inhibited lipoprotein lipase activity in normal subjects. The percentage inhibition, however, did not correlate with the degree of hypertriglyceridemia. A relatively weak inverse correlation was shown to exist between plasma albumin concentration and hepatic lipase activities.