Reduction of oxidized low-density lipoprotein by the long-term use of vitamin E-coated dialyzers in hemodialysis patients

Purpose. Recently, oxidative stress and oxidized low-density lipoprotein (Ox-LDL) have been suggested as causative factors for the progression of arteriosclerosis. Antioxidants such as vitamin E are known to reduce oxidative stress. Therefore, we evaluated the oxidative stress exhibited by different dialysis membranes and clarified the possibility of the effectiveness of the antioxidative action of a vitamin E-coated dialyzer, the Excebrane (EX), in patients receiving maintenance hemodialysis (HD). Methods. We compared the serum levels of Ox-LDL among four groups of subjects: healthy volunteers, patients with mild or moderate renal failure, patients receiving continuous ambulatory peritoneal dialysis, and patients undergoing HD. In order to evaluate the newly developed antioxidative EX membrane, we measured serum Ox-LDL in patients receiving HD with conventional dialyzers who were then switched to dialyzers equipped with the EX membrane. Data were compared in terms of time-course changes following the switch to the new dialyzer to evaluate the effectiveness of its antioxidative action. Results. The highest levels of Ox-LDL were obtained for patients receiving HD. The values of Ox-LDL in the EX group were significantly lower than those in the conventional HD group. In addition, serum levels of Ox-LDL dropped significantly after the switch from the conventional dialyzer to the EX dialyzer. Conclusions. As emphasized in the present study, improvement of the HD process, especially the dialysis membrane system in terms of reduction in oxidative stress, may be important for the prevention of arteriosclerosis progression.