Comparative Study of Oxidative Stress and Antioxidant Enzymes in Post-Hemodialysis Patients and Healthy Controls

Abstract

Background: Chronic kidney disease (CKD) is associated with increased inflammation. Oxidative stress (OS) arises when there is an imbalance between free radical production and antioxidant defense. Thiobarbituric acid-reactive substance (TBARS) is a marker of oxidative stress. In patients treated with regular hemodialysis, the activity of enzymatic and non-enzymatic antioxidative systems is reduced. Oxidative stress damage is further compounded in patients requiring dialysis therapy due to the bio-incompatibility of dialysis membranes in hemodialysis or solutions in peritoneal dialysis.

Methodology: The study includes total N 70; healthy controls (35) and post hemodialysis (HD) patients (35) with age and sex matched undergoing dialysis treatment in Hemodialysis unit of a tertiary care. The levels of oxidative stress markers such as GSSG/GSH, TBARS, Oxidized GSSG along with the activities of antioxidant enzymes Catalase, reduced glutathione (GSH), superoxide dismutase (SOD), Glutathione peroxidase (GPX) were analyzed by spectrophotometric method.

Results: The levels of TBARS, ratio of GSSG/GSH (0.6297±0.6178) and antioxidant enzymes SOD (48.594±14.540), GPX (226.257±179.811) significantly increased in post HD patients compared with control subjects. Similarly, the levels of GSSG and antioxidant enzymes CAT, GSH were significantly decreased in post HD patients compared with control subjects.

Conclusion: In post HD patients the oxidative stress increased with markers such as TBARS and GSSG/GSH with a concomitant decrease in antioxidant systems such as GSH and catalase. The oxidative stress is due to the use of bio-incompatibility membrane during dialysis therapy which is reduced by the use of antioxidant coated membranes