Lipid hydroperoxides: Elevated levels in patients on haemodialysis and patients with chronic renal failure

Patients with renal disease often develop accelerated atherosclerosis resulting in more frequent cardiovascular complications compared to the general population. It has been suggested that peroxidation of low density lipoprotein (LDL) contributes to the pathogenesis of atherosclerosis and glomerulosclerosis. The present study aimed to investigate the phosphatidylcholine hydroperoxide (PC-OOH) content of LDL in patients with chronic renal failure (CRF) and patients on haemodialysis (HD). Plasma was obtained from healthy volunteers (n=20; age 45.8+/-16.9 years), CRF patients (n=23; age 49.4+/-18.1 years) and patients on HD (n=19; age 59.1+/-10.3 years). The lipid profile was studied in all patients. The LDL was isolated by sequential ultracentrifugation. The oxidized PC-OOH content of LDL was measured by high performance liquid chromatography with chemiluminescence detection (HPLC-CL). Compared to the controls, patients with proteinuria had significantly higher plasma concentrations for total cholesterol, LDL-cholesterol and apoB, whereas patients on HD had significantly higher levels of triglycerides and reduced HDL and apoA1 plasma concentrations. Significantly elevated levels of PC-OOH were found in HD patients (22.56+/-13.40 pmol/mg LDL-cholesterol) and CRF patients (13.12+/-15.15 pmol/mg LDL-cholesterol) compared to the controls (0.56+/-0.38 pmol/mg LDL-cholesterol; P<0.001). In HD patients the PC-OOH concentration was higher compared to CRF patients (P<0.05). It was concluded that lipid hydroperoxides increase in renal disease and in patients on HD. These elevated lipid hydroperoxides may contribute to the increased risk for atherosclerosis in these patients.