Abstract 17602: Dietary Sodium Intake and 10-Year Mortality in Older Adults: The Health, Aging, and Body Composition (Health ABC) Study

Abstract

Background: Evidence on the association of sodium intake with mortality is scarce in older adults. Additional information is needed on the optimal level of dietary sodium restriction in this population group.

Methods: Using Cox models, we examined the association between dietary sodium, assessed in year 2 by the food frequency questionnaire, and subsequent 10-year mortality in 2,642 participants of the Health ABC Study (age, 74.6±2.9 years; 48.8% men; 61.7% white; 38.3% black) who were free of heart failure at year 2. Sodium intake was clinically categorized: <1500 mg/d (N=291; 11.0%); 1500-2300 mg/d (N=779; 29.5%); and >2300 mg/d (N=1572; 59.5%). In multivariable models, we adjusted for previously identified mortality risk factors in the Health ABC Study.

Results: After 10 years, 881 participants had died (33.7%). Mortality was 33.8%, 30.7%, and 35.2% among participants consuming <1500, 1500-2300, and >2300 mg/d sodium, respectively (log-rank P=0.074). In unadjusted and adjusted models, sodium intake 1500-2300 mg/d was associated with lower 10-yr mortality compared to <1500- and >2300-mg/d, especially in women and blacks (Table 1). The trend towards higher mortality in the <1500 mg/d group was more prominent in blacks and those with hypertension. In post-hoc analyses in participants with hypertension, use of diuretics was associated with increased risk among those consuming either <1500 mg/d or >2300 mg/d sodium (Fig. 1).

Conclusions: In older adults, the lowest 10-yr mortality was observed in those consuming 1500-2300 mg/d sodium. Among those receiving diuretics, sodium intake <1500mg/d may be associated with increased risk. These findings need prospective validation.