Sodium intake, mortality, and life expectancy in US adults: a retrospective cohort study stratified by cardiovascular health

Purpose This study aims to examine the associations of sodium intake with mortality and life expectancy, stratified by cardiovascular health (CVH) levels. Design/methodology/approach A retrospective cohort study was conducted using NHANES 2007–2014 data linked to mortality follow-up through December 31, 2019, from the National Center for Health Statistics. Sodium intake was measured via 24-h recall, and CVH was assessed by the Life’s Essential 8 score. Weighted Cox models and life table method were used for analysis. Findings During a median follow-up of 8.9 years, 690 total deaths and 198 cardiovascular disease (CVD) deaths occurred. After adjustment for confounders, no significant associations between sodium intake and CVD mortality were observed across CVH strata. In moderate CVH participants, there was a significant inverse association between sodium intake and all-cause mortality (third quartile [Q3] vs first quartile [Q1]: hazard ratio [HR] 0.62, 95% confidence intervals [CI] 0.39–0.98; fourth quartile [Q4] vs Q1: HR 0.39, 95% CI 0.18–0.85). Similar but nonsignificant associations were seen in good CVH participants. Compared with lowest sodium intake, higher sodium intake was generally associated with higher estimated life expectancy among participants with moderate and good CVH, whereas this pattern was not observed among those with poor CVH. Originality/value These findings suggest that the association between sodium intake and mortality may vary across levels of cardiovascular health. Further prospective studies are needed to determine whether cardiovascular health modifies these associations.