Association of selenium and cadmium with heart failure and mortality based on the National Health and Nutrition Examination Survey

Background: The association of selenium and cadmium with heart failure and mortality has not been thoroughly explored. Methods: We analysed data from the National Health and Nutrition Examination Survey (NHANES) database over 12 years (1999–2000, 2003–2004 and 2011–2018), which includes blood selenium and cadmium. Multivariable logistic regression and Cox proportional hazards regression were used. Results: In total, 15,689 participants were enrolled. The multivariate analysis showed that low blood selenium (odds ratio [OR] = 0.952, p < 0.001) and high blood cadmium (OR = 1.345, p < 0.001) were independent risk factors of heart failure. During 96802 person-year follow-up, 1697 deaths occurred. The multivariable adjusted hazard ratio (HR) for all-cause mortality was 0.82 (95% confidence interval [CI] = 0.71–0.95) for middle selenium levels and 0.76 (95% CI = 0.65–0.88) for high selenium levels compared to low selenium levels. Taking the low cadmium levels as reference, the multivariable adjusted HR for all-cause mortality among high cadmium levels was 1.68 (95% CI = 1.44–1.96). Furthermore, the association between selenium, cadmium and cardiovascular mortality was similar to that of all-cause mortality. A subgroup analysis of the study population showed that in individuals with heart failure, although selenium levels were not associated with risk of all-cause mortality, high selenium levels were associated with a lower risk of cardiovascular mortality (HR = 0.33, p = 0.0032). Conclusions: Low blood selenium and high blood cadmium were independent risk factors of heart failure. Blood selenium was inversely associated with all-cause mortality and cardiovascular mortality, whereas blood cadmium was positively associated with them. Furthermore, blood selenium was associated with a lower risk of cardiovascular mortality in individuals with heart failure.