High selenium levels associate with reduced risk of mortality and new-onset heart failure: data from PREVEND

To elucidate the relationship between serum selenium levels and the risk of mortality and new-onset heart failure (HF) in the general adult population.

Selenium was measured in a Dutch cohort and a retrospective analysis of prospectively assessed data was performed. Main outcome measures were all-cause mortality and incidence of new-onset HF separately, and combined as a composite endpoint. Serum selenium was measured in 5973 subjects and mean selenium concentration was 84.6 (±19.5) µg/L. Mean age was 53.6 (±12.1) years and 3103 subjects (52%) were female. Median follow-up was 8.4 years. Selenium levels associated positively with female sex, higher total cholesterol and glucose concentrations, and associated negatively with incidence of anaemia, iron deficiency, current smoking, increased C-reactive protein levels, and higher body mass index. Univariate analysis on all subjects showed no association of continuous selenium concentrations, per 10 µg/L increase, with the composite endpoint (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.87-1.06, p = 0.407). However, significant interaction with smoking status was observed. In non-smoking subjects (n = 4288), continuous selenium concentrations were independently associated with reduced mortality risk (HR 0.87, 95% CI 0.79-0.96, p = 0.005), lower risk of new-onset HF (HR 0.82, 95% CI 0.69-0.96, p = 0.017), as well as reduced risk of the composite endpoint (HR 0.86, 95% CI 0.79-0.94, p = 0.001). In smoking subjects, no associations were found.

Serum selenium was independently associated with multiple indicators of the metabolic syndrome. In addition, high selenium levels were independently associated with reduced mortality and new-onset HF in non-smokers. Well-powered interventional studies are necessary to evaluate the potential benefit of repleting selenium, especially in non-smoking subjects.