Higher serum selenium concentration is associated with lower risk of all-cause and cardiovascular mortality among individuals with chronic kidney disease: A population-based cohort study of NHANES

Abstract

Background: Selenium is an essential nutrient and trace element required for human health and plays an important role in antioxidative and anti-inflammatory processes. However, the long-term impact of selenium levels on the health of patients with chronic kidney disease remains unclear.

Method: Participants in this study were 3,063 CKD adults from the Third National Health and Nutrition Examination Survey (NHANES 1999-2000, 2003-2004, and 2011-2018). The mortality status and the cause of death of the study participants were obtained from the National Death Index records. For all-cause and cardiovascular disease (CVD) mortality, the models employed to estimate hazard ratios (HRs) and 95% CI were Cox proportional hazard models and competing risk models, respectively.

Result: During the follow-up period, 884 deaths occurred, including 336 heart-disease-associated deaths. The median (IQR) concentration of serum selenium was 181.7 (156.1, 201.5) μg/L. After full adjustment, serum selenium levels were associated with a decreased risk of mortality in patients with CKD, including all-cause and CVD mortality (P < 0.001). The multivariate-adjusted HRs (95%CI) were 0.684 (0.549-0.852) for all-cause mortality (P _trend < 0.001) and 0.513 (0.356-0.739) for CVD mortality (P _trend < 0.001) when selenium concentrations were compared according to the extreme quartiles. Selenium levels are inversely associated with an increased risk of all-cause mortality and CVD mortality. Similar results were observed in subgroup and sensitivity analyses.

Conclusion: Higher serum selenium concentration was independently associated with a decreased risk of all-cause and CVD mortality in patients with CKD.

Keywords: antioxidant; chronic kidney disease; mortality; oxidative stress; selenium.

Figure 1

Flow chart.

Figure 2

The cumulative incidence of all-cause death in the four study groups during the follow-up period.

Figure 3

The cumulative incidence of cardiovascular-cause death in the four study groups during the follow-up period.

Figure 4

(A) Restricted cubic spline analyses between serum selenium concentrations and all-cause mortality; (B) Restricted cubic spline analyses between serum selenium concentrations and cardiovascular-cause mortality.