Homocysteine and lipid peroxidation in haemodialysis: role of folinic acidand vitamin E

Background. Cardiovascular diseases are the leading cause of death in haemo dialysis patients. Hyperhomocysteinaemia is an independent risk factor. Bas ic research has provided strong evidence that oxidation of low-density lipo protein (LDL) plays an important role in the pathogenesis of atherosclerosi s. Oxidative stress, lipid metabolism alterations. and hyperhomocysteinaemi a observed in haemodialysis patients could induce increases in LDL oxidatio n. This study was designed to determine the effect of folinic acid on hyper homocysteinaemia and to assess the antioxidant efficacy of folinic acid. Th e antioxidant effect of folinic acid was compared with that of vitamin E. Methods. Sixteen stable patients (I I men, five women. mean age 54.3 +/- 6. 32 years) on standard haemodialysis received 400 mg of vitamin E, orally, a t the end of each haemodialysis session for 3 months. After a 1-month wash- out, they received 10 mg of folinic acid. intravenously, at the end of each haemodialysis session for an additional 3 months. Blood samples were drawn in the morning after an overnight fast and before dialysis. Plasma vitamin E was analysed by high-pressure liquid chromatography. Malondialdehyde (MD A) was determined using a fluorimetric method and plasma copper oxidized an ti-LDL antibodies (Ab-LDLox) were measured with an ELISA method using nativ e LDL and oxLDL as antigens. Plasma homocysteine was determined by an FPIA method. Results. Folinic acid supplements significantly reduced hyperhomocysteinaem ia (-44%), MDA concentrations (-40%), and IgG-LDLox titres (-13%). Conclusions. Treatment with folinic acid lowers plasma homocysteine levels and, like vitamin E. affords antioxidant protection, which prevents lipid p eroxidation. This lowering of lipid peroxidation may reduce the risk of ath erosclerosis and prevent or delay cardiovascular complications in HD patien ts.