Vitamin E Supplementation Increases LDL Resistance to ex vivo Oxidation in Hemodialysis Patients

Abstract

Oxidative stress and alterations in lipid metabolism observed in hemodialysis patients potentiate the low-density lipoprotein (LDL) oxidability, recognized as a key event during early atherogenesis. To explore the effects of an oral vitamin E supplementation on oxidative stress markers and LDL oxidability in hemodialysis patients. Fourteen hemodialysis patients and six healthy volunteers were given oral vitamin E (500 mg/day) for six months. Oxidative stress was assessed using: plasma and lipoprotein vitamin E levels [high-performance liquid chromatography (HPLC) procedure]; thiobarbituric acid reactive substances (TBARS, Yaggi method); and copper-induced LDL oxidation. All parameters were evaluated before initiation of vitamin E supplementation, and at three and six months thereafter. At baseline, a significantly higher TBARS concentration and a higher LDL oxidability were observed in hemodialysis patients when compared to controls. After six months of vitamin E supplementation, TBARS and LDL oxidability were normalized in hemodialysis patients. Our data confirm that hemodialysis patients are exposed to oxidative stress and increased susceptibility to ex vivo LDL oxidation. Since oral vitamin E supplementation prevents oxidative stress and significantly increases LDL resistance to ex vivo oxidation, supplementation by natural antioxidants such as vitamin E may be beneficial in hemodialysis patients.