Trace elements and lipid peroxidation abnormalities in patients with chronic renal failure

Plasma selenium (Se), zinc (Zn) and copper (Cu) levels and antioxidant metalloenzymes, glutathione peroxidase (GPX) and superoxide dismutase (SOD), were studied in 17 patients on maintenance hemodialysis (HD) (group I), 14 uremic patients (group II) and 14 healthy subjects (group III). Plasma Se levels and erythrocyte GPX were significantly lower in the HD group (for Se: 0.69 +/- 0.12 vs. 1.05 +/- 0.13 mumol/l in controls; for erythrocyte GPX: 34.4 +/- 6.4 vs. 49.2 +/- 9 IU/g hemoglobin in controls) and a significant correlation was found between the two parameters (r = 0.66, p less than 0.005). There was also a correlation between decreased plasma Zn and erythrocyte SOD activity (r = 0.58, p less than 0.02) and between decreased plasma Cu and erythrocyte SOD (r = 0.60, p less than 0.02). Plasma malondialdehyde levels were augmented in HD patients (5.08 +/- 0.26 vs. 2.55 +/- 0.15 mumol/l in controls and 2.79 +/- 0.40 mumol/l in the uremic group). The catalase activity was increased in HD patients (202 +/- 24 vs. 140 +/- 40 IU/mg hemoglobin in group III). A defective antioxidant activity may thus contribute to increased peroxidative damage to cells in the course of dialysis.