Oxidative stress markers in pre-uremic patients

The present study was designed to investigate a complex of oxidative stress (OS) markers in patients with chronic renal failure (CRF) and to study the relationship between different OS markers and degree of renal failure. The following indices of OS were measured in plasma: oxidized glutathione (GSSG), reduced glutathione (GSH), total glutathione (TGSH), glutathione redox ratio (GSSG/GSH) and resistance of lipoprotein fraction to oxidation (lag phase of LPF). Baseline diene conjugation level of lipoprotein fraction (BDC-LPF), total antioxidative activity (TAA), diene conjugates (DC), lipid hydroperoxides (LOOH) and thiobarbituric acid-reactive substances (TBARS) were measured in serum. All markers in plasma and serum were measured both in patients with CRF and in healthy controls.

Blood samples were obtained from 38 patients with CRF and from 61 healthy controls. Routine biochemical analyses were performed by using commercially available kits.

Levels of DC, BDC-LPF, LOOH, GSSG and GSSG/GSH ratio were significantly increased and lag phase of LPF was significantly shortened in patients with CRF compared with healthy controls. Serum creatinine and urea levels correlated significantly with GSSG level and GSSG/GSH in patients with CRF. A significant inverse correlation was found between glutathione redox ratio and lag phase of LPF and between GSSG level and BDC-LPF.

The findings suggest that renal patients are in a state of oxidative stress compared with healthy controls. The most informative indices to evaluate the degree of OS in CRF were: GSSG level, GSSG/GSH status, lag phase of LPF and BDC-LPF.