Dyslipidemia, oxidative stress and cardiac dysfunction in children with chronic renal failure: effects of l-carnitine supplementation

ABSTRACT

Secondary carnitine deficiency may develop in chronic renal failure [CRF] patients undergoing long-term hemodialysis [HD], with a resulting higher incidence of cardiovascular diseases, dyslipidemia and oxidative stress. We studied the efficacy of 12 months of L-carnitine supplementation on the amelioration of dyslipidemia, oxidative stress and cardiac dysfunction in 24 CRF children undergoing long-term HD compared with 24 age- and sex-matched controls. Plasma samples were analyzed spectrophotometerically before and after dialysis sessions and after 2-month supplementation with oral L-carnitine [50 mg/kg/day] for free carnitine [FC], the lipid profile, and oxidative stress markers. Echocardiography the day following dialysis measured cardiac diameters, wall thicknesses, left ventricular mass index [MI], end diastole and systole volume indices and functions. The pre-dialysis FC concentration was substantially lower than controls and decreased significantly at the end of the dialysis session. Pre- and post-dialysis plasma levels of free fatty acids [FFAs], trigyleride [TG], total cholesterol [TC] and oxidative stress markers significantly increased while high-density lipoprotein cholesterol [HDL-C] and phospholipids significantly decreased compared to controls. Echocardiography detected a significant increase in cardiac diameters and thickness, and systolic and diastolic cardiac dysfunction. After L-carnitine supplementation, plasma levels of FC increased to normal levels. FFAs, TC and HDL-C returned to control levels while TG, phospholipids, and the oxidative stress markers decreased but remained significantly higher than controls. There was a significant decrease in cardiac diameters and an increase in left ventricular diastolic function [E/A ratio], but no correlation between FC levels and echocardiographic parameters. Pre-dialysis, post-dialysis and after treatment, plasma FC level showed a significant positive correlation with HDL-C and phospholipids and a significant negative correlation with each of oxidative stress markers, FFAs, TG and TC. On the other hand, FFAs showed a significant positive correlation with TG, TC, DC, NO and a significant negative correlation with HDL-C and phospholipids. This study demonstrates that CRF children under regular HD suffer from a decrease in the level of plasma FC, dyslipidemia, oxidative stress, and an increase in cardiac diameters and thickness with impairment of cardiac functions. Oral L-carnitine supplementation at a dose of 50 mg/kg for 2 months can increase plasma FC level, improve dyslipidemia, decrease oxidative stress with reduction of cardiac diameters and increase in diastolic function