Autoantibodies against oxidized LDL in chronic renal failure: Role of renal function, diet, and lipids

Lipid peroxidation (LP) has recently been suggested to trigger the atherosc lerotic process as well as to worsen the progression of renal disease. Auto antibodies against oxidized low-density lipoproteins (Ox-LDLAb) were consid ered to provide a sensitive marker to detect LDL oxidation in vivo. To date few studies have been reported on Ox-LDLAb levels in patients with differe nt degrees of renal failure. The aim of this study was to evaluate the infl uences of renal function, dietary manipulation, and lipids on Ox-LDLAb conc entrations in uremic patients either on conservative or replacement therapy . Seventy-one patients (42 males, 29 females) aged 60 +/- 19 years with chr onic renal failure (CRF) of different etiology and deg ree were divided int o four groups according to serum creatinine levels [sCr(mg/dl)] and diet: C RF I greater than or equal to 1.5-3.0, CRF II > 3.0-5.5, and CRF III > 5.5 were all patients on a conventional low-protein diet, while a fourth group included patients on a vegetarian diet supplemented with keto analogues and amino acids (CRF SD >3.0). A further group was represented by patients on dialysis therapy. All patients were examined for Ox-LDLAb, triglycerides (T G), total cholesterol, HDL and LDL cholesterol, and apolipoproteins Apo Al, Apo B, and Lp(a). The results were compared with those of 20 controls (9 m ales and 11 females) aged 52 +/- 11 years with sCr <1.5 mg/dl. Ox-LDLAb inc reased, although not significantly, with TG and Lp(a) from the early stages of CRF along with the deterioration of renal function. However, TG and Lp( a) levels were significantly higher in all groups of patients except those on vegetarian diet (CRF SD). This group also showed the lowest Ox-LDLAb lev els. No relationship was observed between lipids or apolipoproteins and Ox- LDLAb. Hyperlipidemic patients did not show higher Ox-LDLAb levels than nor molipidemics. Our results show a progressive increase of LP as the renal fu nction declines, which may account for the increased risk of cardiovascular disease reported in uremia. Dialysis does not correct significantly the ox idative state observed in patients with end-stage renal disease. Vegan diet , by reducing LP, TG, and Lp(a), is supposed to decrease the risk of cardio vascular disease and worth being reconsidered as an alternative effective t herapeutic tool in patients with advanced CRF. Copyright (C) 2001 S. Karger AG. Basel.