ANTIOXIDANT EFFECTS OF A SUPPLEMENTED VERY-LOW PROTEIN-DIET IN CHRONIC-RENAL-FAILURE

Increased peroxidation of lipids in red blood cells (RBC) in patients with advanced chronic renal failure (CRF) reflects increased generatio n of reactive oxygen species (ROS), which may contribute to the metabo lic damage induced by CRF and to its progression. We have evaluated pa rameters indicative of lipoperoxidation (LPO) of RBC at baseline in pa tients with CRF compared to controls, and the effects of a very low pr otein diet supplemented with amino and keto acids and vitamins A, C, E (VLPD) over a 6-month period. The presence of peroxidation damage in CRF patients before the administration of VLPD was demonstrated by ele vated levels of free malondialdehyde (MDA) (p < .0003) and decreased l evels of polyunsaturated fatty acids (PUFA), particularly C20:4 (p (.0 01), C22:4 (p < .0001) and C22:5 (p < .0001) when compared to controls . Similarly, RBC vitamin E content was significantly decreased (p < .0 001) while enzymatic activities were unalterated. VLPD reduced erythro cyte LPO as suggested by (a) decreased levels of free and total RBC MD A (p < .003 and p < .03, respectively), (b) increased levels of PUFA, particularly C22:4 and C22:5 (p < .003 and p < .03, respectively), and (c) increased levels of vitamins A and E (p < .001 and p < .04, respe ctively) as compared to prediet results. Antioxidant enzyme activities were not modified. These results suggest that VLPD has a protective r ole against LPO of erythrocytes in patients with CRF. Copyright (C) 19 96 Elsevier Science Inc.