Effect of carnitine supplementation on cardiac function in hemodialyzed children

Previous studies have reported conflicting results of carnitine supplementation on plasma lipids in patients with chronic renal failure. We therefore performed a four center, double-blind placebo controlled trial to evaluate the effects of post-hemodialysis intravenous injection of L-carnitine in ESRD patients on maintenance hemodialysis. Thirty-eight patients received up to six months of L-carnitine infusions (20 mg/kg) post-dialysis and 44 patients received placebo infusions. In both groups of patients, baseline pre-dialysis plasma and red blood cell total carnitine levels were normal, but pre-dialysis plasma-free carnitine concentrations and free/total ratios were subnormal, and plasma acyl levels were elevated. Post-dialysis plasma free and total carnitine concentrations were also subnormal. Plasma and red blood cell total carnitine levels rose eightfold in carnitine recipients, but were unchanged from baseline in those receiving placebo. There were no significant changes observed in plasma triglycerides, HDL-cholesterol or other lipoprotein parameters in either the carnitine or placebo treated groups. We conclude that carnitine metabolism is altered in uremia. Furthermore, in a randomly-selected hemodialysis population, L-carnitine injection at the dose of 20 mg/kg results in significant increases in blood (and perhaps tissue) carnitine levels, but this is not associated with any major effects on lipid profiles.

Twenty-nine hemodialyzed patients with hypertriglyceridemia were given L-carnitine (20 mg/kg iv at the end of each dialysis) for 120 days and then placebo for the same duration in order to evaluate the lipid-lowering effects of the metabolite. A dramatic reduction in triglyceride levels was observed only in the group of patients (n = 12) with high basal triglyceride values, low levels of high-density lipoprotein-cholesterol, and with apoprotein A at the lower limit of normal range. During L-carnitine treatment these patients exhibited significantly increased high-density lipoprotein-cholesterol and apoprotein A. No rebound effects were observed. L-Carnitine did not provoke changes in the lipid parameters in the group (n = 17) with high basal triglyceride values, and normal high-density lipoprotein-cholesterol and apoprotein A. Hematocrit values increased in all the 29 patients during L-carnitine treatment. At the end of the experimental protocol, L-carnitine dosage was increased to 60 mg/kg iv (at the end of each dialysis) in four patients of the group of nonresponders and prolonged for 60 days. This produced a considerable reduction in triglyceride levels. The above results suggest that L-carnitine can be effective in the management of hypertriglyceridemia in the hemodialyzed patient especially when low high-density lipoprotein-cholesterol levels are present.