The effect of vitamin E supplementation on LDL oxidation in dialysis patients

Atherosclerotic cardiovascular disease is the leading cause of death in patients with end stage renal disease (ESRD) on dialysis. Dyslipidemia is a characteristic of most dialysis patients and may contribute to the high cardiovascular mortality. Oxidation of low density lipoprotein (LDL) may be the crucial step in the pathogenesis of atherosclerosis. Alpha-tocopherol (AT) is the major antioxidant in LDL and dietary supplementation has been shown to increase the oxidative resistence of LDL. The purpose of this study was to test the effect of AT supplementation on oxidative resistance of LDL in patients with chronic renal failure and healthy controls. 10 hemodialysis (HD), 10 peritoneal dialysis (PD), and 10 healthy controls (C) matched for age and gender were given 800 IU/day AT for 12 weeks. LDL was isolated by ultracentrifugation at baseline and after supplementation, and subjected to copper-catalyzed oxidation for 5 hours. Oxidation was measured by the formation of conjugated dienes (CD) and lipid peroxides (LP). Following AT supplementation, CD lag time increased significantly by 40% in the C group, 42% in the HD group, and by 57% in the PD group (p<0.005). Similarly, lipid peroxide lag phase was prolonged by 31%, 33%, and 47%, in C, HD, and PD, respectively (p<0.025). These results indicate that ESRD patients on dialysis respond favorably to AT supplementation.