POS-587 EFFECT OF ZINC AND VITAMIN C SUPPLEMENTATION ON OXIDATIVE STRESS IN HEMODIALYSIS AND RELATIONSHIP WITH INFECTIONS: A STUDY OF 46 PATIENTS.

Introduction: Oxidative stress (OS) has been linked with several complications in end-stage renal disease (ESRD) That result from excess amounts of reactive oxygen species (ROS) and/ or decreased antioxidant activity Infections occurring in hemodialysis expose patients to a higher level of OS The aim of the present study was to investigate oxidant and antioxidant status in chronic renal failure patients undergoing hemodialysis, effect of vitamin C and zinc therapy supplementation on these two status and OS variation with infections Methods: A prospective study was carried out in the hemodialysis unit of Sfax CNSS polyclinic, for a period of 75 days, from March 1st, to June 15th 2020, during the first wave of COVID-19 in Tunisia We administrated for all patients 15mg per day of zinc bisglycinate, for 60 days In order to minimize the risk of secondary oxalosis with vitamin C, we opted for discontinuous therapy with low doses (500mg/week for 8weeks) Blood samples were collected before and after the supplementation therapy The samples were analyzed for malondialdehyde (MDA) level, as index of lipid peroxidation, and for catalase level, as index of antioxidant activity We determined MDA levels by dosing thiobarbituric acid reactive substances (TBARS), detected by the TBARS assay, using thiobarbituric acid as a reagent The activity of catalase was measured based on the peroxidatic function of catalase with methanol as the hydrogen donor in the presence of H2O2 We compared the levels of each biomarker before and after the therapy To determine an association between infections and OS in hemodialysis recipients, we assessed all types of infections (viral, parasitic and bacterial, mild and severe) which occurred during the period of the study We compared MDA and catalase levels in infected patients and in non-infected patients, before and after the therapy supplementation Results: Increased levels of TBARS and decreased levels of catalase activity were noticed in all the patients before the therapy TBARS significantly decreased after the therapy (figure1), while catalase activity significantly increased (figure2) thirteen patients had infections during the study They were bacterial in 10 cases, viral in 2 cases parasitic in one case, cutaenous in 6 cases, pulmonary in 2 cases, urinary in 2 cases, digestive in 2 cases and vascular in one case Mild gravity was assessed in 8cases Severe infections were noticed in 5cases We noticed significantly higher levels of MDA in the infected Group as compared to the non-infected group Catalase activity was slightly higher in the infected group as compared to the non-infected group, with no statistically significant difference Nevertheless, levels variation after supplementation therapy are comparable in the two groups (figure3, figure4) Conclusions: Our results suggest the possible preventive role of antioxidant therapy by zinc and vitamin C in the oxidative stress in hemodialysis patients Also, patients who are susceptible to infections in hemodialysis have probably more levels of OS, specially lipid peroxidation Therefore, antioxidant therapies find its interest to improve their oxidative profile No conflict of interest