title: Effect of selenium supplementation on glutathione peroxidase enzyme activity in patients with chronic kidney disease: a randomized clinical trial.
abstract: BACKGROUND
  Plasma selenium (Se) concentration and glutathione peroxidase (GSH-Pxs) enzyme activity of the patients with chronic kidney disease (CKD) are usually lower than healthy individuals; however, the effect of Se supplementation on the GSH-Pxs activity in those patients remains unclear.
  
  
  OBJECTIVE
  This study aimed to assess the effect of Se supplementation on plasma Se concentration and red blood cell (RBC) GSH-Pxs activity in patients with different stages of CKD.
  
  
  METHODS
  In this randomized clinical trial, forty-five patients with CKD who attended in a nephrology clinic were recruited. The patients were randomly allocated into three groups according to their creatinine clearance rate and were supplemented with daily Se 200 mcg for three months. Plasma Se concentration and RBC GSH-Pxs activity were measured in each patient at the beginning and at the end of the study. This clinical trial was registered in the Iranian Registry of Clinical Trials (www.irct.ir) with registration number ID of IRCT201305318501N2.
  
  
  RESULTS
  Plasma Se concentration and RBC GSH-Pxs activity increased significantly in all three groups of patients with CKD (P < 0.05). There were no significant differences between three groups regarding baseline plasma Se (P = 0.268) and RBC GSH-Pxs activity (P = 0.741).
  
  
  CONCLUSIONS
  Se supplementation can increase plasma Se concentration and RBC GSH-Pxs activity in patients with different stages of CKD.
authors.affiliation: Department of Nephrology, Faculty of Medicine, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Omid
authors.initials: O
authors.lastname: Sedighi
authors.affiliation: Department of Clinical Biochemistry and Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Mehryar
authors.initials: M
authors.lastname: Zargari
authors.affiliation: Department of Internal Medicine, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Gharmohammad
authors.initials: G
authors.lastname: Varshi
keywords: Glutathione Peroxidase; Renal Insufficiency, Chronic; Selenium