Sodium intake and mortality in the NHANES II follow-up study.
OBJECTIVE
US Dietary Guidelines recommend a daily sodium intake <2300 mg, but evidence linking sodium intake to mortality outcomes is scant and inconsistent. To assess the association of sodium intake with cardiovascular disease (CVD) and all-cause mortality and the potential impact of dietary sodium intake <2300 mg, we examined data from the Second National Health and Nutrition Examination Survey (NHANES II).


METHODS
Observational cohort study linking sodium, estimated by single 24-hour dietary recall and adjusted for calorie intake, in a community sample (n = 7154) representing 78.9 million non-institutionalized US adults (ages 30-74). Hazard ratios (HR) for CVD and all-cause mortality were calculated from multivariable adjusted Cox models accounting for the sampling design.


RESULTS
Over mean 13.7 (range: 0.5-16.8) years follow-up, there were 1343 deaths (541 CVD). Sodium (adjusted for calories) and sodium/calorie ratio as continuous variables had independent inverse associations with CVD mortality (P = .03 and P = .008, respectively). Adjusted HR of CVD mortality for sodium <2300 mg was 1.37 (95% confidence interval [CI]: 1.03-1.81, P = .033), and 1.28 (95% CI: 1.10-1.50, P = .003) for all-cause mortality. Alternate sodium thresholds from 1900-2700 mg gave similar results. Results were consistent in the majority of subgroups examined, but no such associations were observed for those <55 years old, non-whites, or the obese.


CONCLUSIONS
The inverse association of sodium to CVD mortality seen here raises questions regarding the likelihood of a survival advantage accompanying a lower sodium diet. These findings highlight the need for further study of the relation of dietary sodium to mortality outcomes.
Cohen
Hillel W
HW
Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY 10461, USA. hicohen@aecom.yu.edu
Hailpern
Susan M
SM
Fang
Jing
J
Alderman
Michael H
MH
D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000401:mortality*; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D009749:Nutrition Surveys; D011159:Population Surveillance / Q000379:methods*; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage / Q000009:adverse effects*; D014481:United States / Q000453:epidemiology
D017673:Sodium Chloride, Dietary