Abstract
Purpose
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.
Conclusion
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.
Keywords
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Article Info
Footnotes
One author (MHA) has been an unpaid consultant to the Salt Institute, a trade organization. Neither he nor the other authors have ever received research support, consulting fees, or speaker honoraria from either the Salt Institute or any other commercial entity related to use of sodium.
Identification
Copyright
© 2006 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
