Effects of Zinc Supplementation on Oxidative Stress in Patients Undergoing Maintenance Hemodialysis

Abstract

Introduction: The aim of this study was to examine the effects of Zn supplementation on oxidative stress by evaluating changes in serum Copper (Cu) to Zinc (Zn) ratio, homocysteine (hCys), Glutathione (GSH), Total Bilirubin (TB) and Catalase (CAT) activity in hemodialysis patients. Methods: Seventy-seven HD patients were enrolled in a multicenter simple-blind randomized clinical trial. Only 37 HD patients completed the study. They were randomly divided into two groups and supplemented with zinc sulfate (n = 17) or placebo (n = 20) for two months. Serum Zn and Cu were measured by atomic absorption spectrophotometry. Serum hCys was measured by immunology method, serum GSH and CAT activity were assessed by spectrophotometry method and TB was measured by colorimetric method. Determinations were performed before and after supplementation. Findings: After zinc supplementation, serum Zn, serum GSH, and Serum Total Bilirubin (STB) significantly increased. Serum Cu to Zn ratio, serum hCys, and CAT activity significantly decreased in the Zn Zn-supplemented group. Conclusion: Zinc supplementation increased serum antioxidant factors such as Zn, GSH, and bilirubin and decreased serum oxidative factors such as copper to zinc ratio, hCys, and decreased CAT activity. The study results suggest that zinc supplementation may be a useful tool for the improvement of oxidative stress in HD patients.