Antioxidant therapy by oral vitamin E and vitamin E-coated dialyzer in CAPD and haemodialysis patients

Oxidative stress, increased lipid peroxidation, and impaired function of antioxidant system may contribute to the accelerated development of atherosclerosis in chronic renal failure patients during renal replacement therapy. The aim of the study was to investigate the influence of oral vitamin E (400 mg/day) in 14 patients who underwent continuous ambulatory peritoneal dialysis (CAPD) and effects of the vitamin E-coated dialyzer in 14 haemodialysis patients on several antioxidant biochemical parameters. Six-week treatment with oral vitamin E in CAPD patients and three-month treatment using vitamin E-coated dialyzer in haemodialysis patients led to the significant decrease of plasma malondialdehyde, to the increase of plasma vitamin E and to the increase of erythrocyte vitamin E in haemodialysis patients. No significant changes of erythrocyte antioxidant enzyme--superoxide dismutase, glutathione peroxidase and catalase were found during the both types of antioxidant therapy. At the end of the third month of haemodialysis study the significant increase of erythrocyte glutathione in haemodialysis patients was found, but that value was significantly lower as normal range. Six-week interruption of the administration of oral vitamin E in CAPD patients led to the significant decrease of erythrocyte superoxide dismutase and plasma vitamin E. Ten-week interruption of the use of vitamin E-coated dialyzer led to the significant increase of plasma malondialdehyde and to the decrease of plasma and erythrocyte vitamin E in haemodialysis patients, near to the values at the beginning of the study. Our study confirmed the beneficial effect of oral administration of vitamin E and the use of vitamin E-coated dialyzer against oxidative stress in CAPD and haemodialysis patients.