Selenium and the risk of cardiovascular disease and all-cause mortality: a meta-analysis of prospective observational studies and randomized controlled trials

Background This meta-analysis of prospective observational studies and randomized controlled trials (RCTs) was carried out to explore the association between selenium and the risk of cardiovascular disease (CVD) and all-cause mortality. Methods and Study Design We searched the PubMed, EMBASE and Web of Science database for eligible studies which included the relationship between selenium and the outcomes of interest. 25 prospective observational studies and 9 RCTs were included in our meta-analysis. Results The observational studies showed that there was a significant inverse association between serum selenium and the risk of CVD (RR: 0.78; 95% CI: 0.68–0.89), coronary heart disease (CHD) (RR: 0.75; 95% CI: 0.58–0.95) and all-cause mortality (RR: 0.77; 95% CI: 0.71–0.84). We also found a significant inverse association between selenium supplements and the risk of total CVD (RR: 0.78; 95% CI: 0.62–0.98) and all-cause mortality (RR: 0.81; 95% CI: 0.65-1.00) in RCTs studies. Conclusions Our meta-analysis found a significant inverse association between selenium and CVD, CHD, and all-cause mortality in prospective observational studies and RCTs, which indicate the selenium has protective effect in cardiovascular disease and all-cause mortality.