Dietary and serum selenium in coronary heart disease and all-cause mortality: An international perspective

Background and Objectives: The objective of this study was to explore the associations of dietary selenium and serum selenium concentration with coronary heart disease (CHD) prevalence and all-cause mortality among participants in United States. Methods and Study Design: Using data collected from the National Health and Nutrition Examination Survey (NHANES) 1999-2006, 17867 individuals were included. Logistic regression analyses were used to explore the associations between dietary selenium intake and serum selenium concentration and prevalent of CHD. Multivariable Cox regression was used to identify the association between dietary selenium intake and all-cause mortality. The nonlinear relationships were assessed using generalized additive models. Results: A U-shaped association between dietary intake of selenium and all-cause mortality was observed. Compared with the lowest quartile, the second quartile of dietary intake of selenium was inversely associated with all-cause mortality (Hazard ratio [HR]: 0.802, 95% confidence interval [CI]: 0.658, 0.977, p=0.029). There was no evidence of association between dietary selenium intake and CHD risk (Odds ratio [OR]: 1.001, 95% CI: 0.999, 1.003, p=0.206). Furthermore, serum selenium concentration was negatively associated with CHD risk (OR: 0.989, 95% CI: 0.981, 0.997, p=0.006). Comparing with the lowest quartile, participants with the highest serum selenium concentration had a statistically significant decreased prevalence of CHD, with OR (95% CI) of 0.417 (0.259, 0.669) (p<0.001). The smoothing curve also showed a non-linear relationship between serum selenium and risk of CHD. Conclusions: This analysis suggested that a higher serum selenium concentration was associated with reduced risk of CHD, and that the relationship was non-linear. In addition, an appropriate dietary selenium intake might reduce all-cause mortality.