Plasma Levels of Selenium (SE) and Glutathion Peroxydase (GSH-PX) and their Relationship to Supplementation of Selenium in Patients with Chronic Renal Failure (CRF) on Hemodialysis (HD)
Author(s): Popov I, Manolov IV, Atanasova B, Vasilev V, Dimitrova V, Arabadjieva D, Velkova N, Yonova D
Introduction: Plasma levels of Se and GSH-Px decrease with the progression of renal impairment and is particularly pronounced at the end stage of chronic kidney disease (CKD) as kidney proximal tubular cells are the main source of pGSH-Px activity. A number of authors found that Se supplementation increases its plasma levels in patients on HD, but publications about influence of Se supplementation on plasma GSH-Px are controversial-from a lack of any effect to a significant increase of the enzyme. The study aims to monitor levels of plasma selenium (pSe) and glutathione peroxidase (pGSH-Px) in patients on HD treatment with Se deficit, orally supplemented with Se for 3 months, and to evaluate the supplementation on pSe and pGSH-Px.
Material and Methods: 61 patients on regular hemodialysis, divided into two groups (1st group-33 pts. with pSe deficit and, 2nd group-28 with normal pSe levels) were tested at the beginning of dialysis sessions for serum hemoglobin, total protein, albumin, creatinine, urea, uric acid, C-reactive protein (CRP), phosphorus, potassium plasma Se and pGSH-Px activity. The same parameters were re-examined at the end of the study. The patients of the 1st group were supplemented with oral Se for 3 months and the results in the two groups were compared.
Results: All parameters (except pSe and pGSH-Px in the 1st group) showed no significant differences in the beginning and the end of the follow-up period in both patients groups. The levels of pSe and pGSH-Px in the 2nd group also showed no significant change, but in the 1st group both parameters increased significantly at the end of the 3-months period. We found a significant correlation between pSe/pGSH-Px (p<0.01), and between pGSH-Px/Creatinine (p<0.01) at the start and the end of the study.
Conclusion: Our study suggests that supplementation of oral Se in patients with CKD on regular HD, significantly increases not only pSe, but pGSH-Px as well, despite a proved presence of bilateral nephrosclerosis in all patients of both groups. As a positive effect, at least one of the members of anti-oxidant system in this patients contingent is enhanced, namely pGSH-Px.