Lipoprotein Metabolism in Patients with Chronic Uremia

Lipoprotein metabolism has been studied in six patients with chronic uremia before and during maintenance hemodialysis. Special attention was paid to experimental conditions to control the effect of intermittent heparin administration on various parameters of lipid metabolism. The concentration of VLDL was elevated in five of the six patients before dialysis. During hemodialysis the concentration decreased in these five patients but increased in the patient with an initially normal VLDL level. The concentration of HDL cholesterol was abnormally low before dialysis and increased in all patients after the beginning of dialysis. No consistent changes were observed in the concentration of LDL. The cholesterol/triglyceride ratio of LDL was significantly lower in uremic patients than in controls both before and during dialysis. The activity of postheparin plasma hepatic lipase was markedly decreased in uremic patients both before and during dialysis as compared to age‐matched controls. The activity of postheparin plasma lipoprotein lipase was lower in uremic patients than in controls both before and after the initiation of dialysis, but the difference was statistically significant only before the beginning of the treatment. Hemodialysis did not sect the activity of postheparin plasma lipoprotein lipase or hepatic lipase. The removal constant of i.v. administered lipid emulsion (Intralipid®) decreased in four patients and increased in one patient after the beginning of dialysis. Intermittent heparin administration at two‐day intervals in three healthy volunteers did not influence the acitvity of postheparin plasma lipases. The activity of both enzymes decreased during a long‐term heparin infusion in three patients with deep vein thrombosis. After termination of the heparin treatment the activity of both enzymes gradually returned to the pretreatment level.