Trace Elements Status and Their Associations With Related Antioxidant Enzyme Activities in Patients Receiving Peritoneal Dialysis and Hemodialysis

Objective: It remains ambiguous as to whether the status of trace elements would affect their related enzyme activities toward defending a possible higher oxidative stress in patients receiving peritoneal dialysis (PD) or hemodialysis (HD) treatment. We investigated copper (Cu), zinc (Zn), and selenium (Se) status in patients receiving PD or HD treatments and further determined the association of these trace elements with their related antioxidant capacities in those patients. Methods: Sixty PD and 80 HD patients before and after HD treatment had their blood drawn. Demographic, clinical, and 24-hour diet recall data were recorded and collected. Plasma trace elements, oxidative stress indicators, and antioxidant enzyme activities were measured. Results: Patients receiving PD or HD treatments experienced similar Zn and Cu intakes. PD and HD patients displayed adequate mean plasma Cu, Zn, and Se levels. Patients receiving PD treatment showed significantly higher levels of Cu, Zn, advanced oxidation protein products (AOPPs), and superoxide dismutase (SOD) activity, but had significantly lower levels of Se and total antioxidant capacity when compared to levels in the HD patients at the pre-HD session. The levels of 3 trace elements and AOPP increased significantly, while the levels of glutathione (GSH), oxidized glutathione (GSSG), GPx, and SOD activities decreased significantly after receiving HD treatment than did the levels in the pre-HD session. Plasma Cu, Se, and Zn levels had a different correlation with plasma AOPP level, GPx, and SOD activities during PD, pre- or post-HD sessions. Plasma Cu, Zn, and Se levels did not have any association with their associated enzyme activities in patients with PD, while plasma Cu and Zn levels may have influenced SOD activity in HD patients. Conclusions: An adequate Cu, Zn, and Se status is required in order to help their associated enzyme activity cope with increased oxidative stress during PD or HD sessions.