Sodium Intake and Mortality Follow-Up in the Third National Health and Nutrition Examination Survey (NHANES III)
- 619 Downloads
Sodium restriction is commonly recommended as a measure to lower blood pressure and thus reduce cardiovascular disease (CVD) and all-cause mortality. However, some studies have observed higher mortality associated with lower sodium intake.
To test the hypothesis that lower sodium is associated with subsequent higher cardiovascular disease (CVD) and all cause mortality in the Third National Health and Nutrition Examination Survey (NHANES III).
Observational cohort study of mortality subsequent to a baseline survey.
Representative sample (n = 8,699) of non-institutionalized US adults age ≥30, without history of CVD events, recruited between 1988–1994.
Measurements and main results
Dietary sodium and calorie intakes estimated from a single baseline 24-h dietary recall. Vital status and cause of death were obtained from the National Death Index through the year 2000. Hazard ratio (HR) for CVD mortality of lowest to highest quartile of sodium, adjusted for calories and other CVD risk factors, in a Cox model, was 1.80 (95% CI 1.05, 3.08, p = 0.03). Non-significant trends of an inverse association of continuous sodium (per 1,000 mg) intake with CVD and all-cause mortality were observed with a 99% CI of 0.73, 1.06 (p = 0.07) and 0.86, 1.04 (p = 0.11), respectively, while trends for a direct association were not observed.
Observed associations of lower sodium with higher mortality were modest and mostly not statistically significant. However, these findings also suggest that for the general US adult population, higher sodium is unlikely to be independently associated with higher CVD or all-cause mortality.
KEY WORDSsodium intake mortality cardiovascular disease Third National Health and Nutrition Examination Survey (NHANES III)
The authors wish to acknowledge the NHANES III participants and the investigators as well as the National Center for Health Statistics and its Research Data Center for making available the limited access linked mortality data. However, the authors take full and sole responsibility for the integrity of the data analyses and the contents of this article.
We also wish to thank the Department of Epidemiology and Population Health of the Albert Einstein College of Medicine for financial support for this work.
Conflicts of Interest
Michael H. Alderman has been an unpaid consultant to the Salt Institute, a trade organization. He has never received research support, consulting fees or speaker honoraria from either the Salt Institute or any other commercial entity related to use of sodium. Hillel W. Cohen and Susan M. Hailpern have no conflicts of interest to disclose.
- 1.U.S. Department of Health and Human Services and U.S. Department of Agriculture. Dietary Guidelines for Americans, 2005. Available at: http://www.health.gov/dietaryguidelines/dga2005/. Last accessed February 16, 2007.
- 3.Pearson TA, Blair SN, Daniels SR, Eckel RH, Fair JM, Fortmann SP, Franklin BA, Goldstein LB, Greenland P, Grundy SM, Hong Y, Miller NH, Lauer RM, Ockene IS, Sacco RL, Sallis JF Jr, Smith SC Jr, Stone NJ, Taubert KA. AHA guidelines for primary prevention of cardiovascular disease and stroke: 2002 update. Circulation. 2002;106(33):88–91.PubMedCrossRefGoogle Scholar
- 4.Hooper L, Bartlett C, Davey Smith G, Ebrahim S. Advice to reduce dietary salt for prevention of cardiovascular disease. Cochrane Database of Systematic Reviews 2004, Issue 1. Art. No.: CD003656. DOI 10.1002/14651858.CD003656.pub2.
- 9.Cook NR, Cutler JA, Obarzanek E, Buring JE, Rexrode KM, Kumanyika SK, Appel LJ, Whelton PK. Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of trials of hypertension prevention (TOHP). BMJ 2007 DOI 10.1136/bmj.39147.604896.55.
- 10.Kagen A, Popper JS, Rhoads GG, Yano K. Dietary and other risk factors for stroke in Hawaiian Japanese men. Stroke. 1985;16:390–6.Google Scholar
- 11.Cohen JD, Grandis G, Cutler JA, Neaton JD, Juller LH, Stamler J. Dietary sodium intake and mortality: MRFIT Follow-up Study Results (abstract). Circulation. 1999;100(suppl 1):1–524.Google Scholar
- 14.Cohen HW, Hailpern SM, Fang J, Alderman MH. Sodium intake and mortality in the NHANES II Follow-up Study. Am J Med. 2006;119:274e7–5e14.Google Scholar
- 16.National Center for Health Statistics, Plan and Operation of the Third National Health and Nutrition Examination Survey 1988–94, Hyaftsville, MD, July 1994 DHHS Publication No, (PHS) 94-1308. Available at http://www.cdc.gov/nchs/data/series/sr_01/sr01_032.pdf Last accessed April 16, 2008.
- 17.National Death Index, Division of Vital Statistics, National Center for Health Statistics. What is the NDI? Hyattsville, MD, 1999. Available at http://www.cdc.gov/nchs/r&d/ndi/what_is_ndi.htm Last accessed April 16, 2008.
- 18.National Center for Health Statistics. Research Data Center Website, Hyattsville, MD, 2007. Available at http://www.cdc.gov/nchs/r&d/rdc.htm. Last accessed April 16, 2008.
- 19.National Center for Health Statistics. International Classification of Diseases, Ninth Revision (ICD-9). Available at: ftp://ftp.cdc.gov/pub/Health_Statistics/ NCHS/Publications/ICD-9. Last accessed April 16, 2008.Google Scholar
- 20.World Health Organization. International Statistical Classification of Diseases and Related Health Problems 10th Revision. WHO, 2007. Available at: http://www.who.int/classifications/apps/icd/icd10online/. Last accessed April 16, 2008.
- 21.Willett W, Stampfer MF. Total energy intake: implications for epidemiologic analyses. Am J Epidemiology. 1986;124:17–27.Google Scholar
- 22.Willett W. Nutritional Epidemiology. 2nd ed. Oxford, England: Oxford University Press; 1998.Google Scholar