The Effect of Parenteral Selenium Therapy on Serum Concentration of Inflammatory Mediators: a Systematic Review and Dose-Response Meta-Analysis of Randomized Clinical Trials

Selenium can protect against inflammation through its incorporation in selenoenzymes; therefore, in this study, we assessed the effect of parenteral selenium on C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) through a systematic review and meta-analysis on randomized controlled trials (RCTs). A systematic search was performed in the databases, including PubMed, Scopus, Cochrane, clinicaltrials.gov, and ISI Web of Science, up to October 2022, with no limitation in study location or publication time. We calculated the effect size by the mean change from baseline in serum concentration of selected inflammatory mediators and their standard deviations. DerSimonian and Laird random effects model was used to estimate the heterogeneity and summary of the overall effects. Included studies in this systematic review and meta-analysis were 10 and 8 RCTs, respectively. Our results revealed parenteral selenium significantly decreased serum IL-6 (Weighted Mean Difference (WMD) = -3.85 pg/ml; 95% confidence interval (CI) = -7.37, -0.34 pg/ml; p = 0.032) but did not significantly change serum levels of CRP (WMD = 4.58 mg/L; 95% CI = -6.11, 15.27 mg/L; P = 0.401) compared to the comparison groups. According to our results, parenteral selenium supplementation might reduce serum levels of inflammatory mediators.