Sodium and Potassium Intake and Mortality Among US Adults: Prospective Data From the Third National Health and Nutrition Examination Survey

Study Questions:

What are the joint effects of dietary sodium and potassium intake on risk of mortality?


To investigate estimated usual intakes of sodium and potassium as well as their ratio in relation to risk of all-cause and cardiovascular disease (CVD) mortality, the Third National Health and Nutrition Examination Survey Linked Mortality File (1988-2006), a prospective cohort study of a nationally representative sample of 12,267 US adults, studied all-cause, cardiovascular, and ischemic heart disease (IHD) mortality. The investigators used Cox proportional hazards regression to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause, CVD, and IHD mortality.


During a mean follow-up period of 14.8 years, the investigators documented a total of 2,270 deaths, including 825 CVD deaths and 443 IHD deaths. After multivariable adjustment, higher sodium intake was associated with increased all-cause mortality (HR, 1.20; 95% CI, 1.03-1.41 per 1000 mg/d), whereas higher potassium intake was associated with lower mortality risk (HR, 0.80; 95% CI, 0.67-0.94 per 1000 mg/d). For sodium-potassium ratio, the adjusted HRs comparing the highest quartile with the lowest quartile were HR, 1.46 (95% CI, 1.27-1.67) for all-cause mortality; HR, 1.46 (95% CI, 1.11-1.92) for CVD mortality; and HR, 2.15 (95% CI, 1.48-3.12) for IHD mortality. These findings did not differ significantly by sex, race/ethnicity, body mass index, hypertension status, education levels, or physical activity.


The authors concluded that a higher sodium-potassium ratio is associated with significantly increased risk of CVD and all-cause mortality.


This study reports a significant monotonic association between increasing sodium-potassium ratio and risk for all-cause, CVD, or IHD mortality. This association was independent of age, sex, race/ethnicity, and other covariates. Based on these data, public health recommendations should consider emphasizing simultaneous reduction in sodium intake and increase in potassium intake. Encouraging consumption of fruits and vegetables would the safest and preferred way to increase potassium intake.

Keywords: Cause of Death, Potassium, Myocardial Ischemia, Follow-Up Studies, Sodium, Dietary, Cardiovascular Diseases, Nutrition Surveys

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