Dietary sodium and risk of stroke in the Northern Manhattan study

Abstract

Background and purpose: The American Heart Association recommends limiting sodium intake to ≤ 1500 mg/day for ideal cardiovascular health. Although sodium intake has been linked to vascular disease by direct relationship with hypertension, few studies have supported an association with stroke risk.

Methods: Participants were from the Northern Manhattan Study (mean age 69 ± 10 years, 64% women, 21% white, 53% Hispanic, 24% black), a population-based cohort study of stroke incidence. Sodium intake was assessed with a food frequency questionnaire at baseline and evaluated continuously and categorically: ≤ 1500 mg/day (12%), 1501 to 2300 mg/day (24%), 2301 to 3999 mg/day (43%), and ≥ 4000 mg/day (21%). Over a mean follow-up of 10 years, we examined the association between sodium consumption and 235 strokes using Cox models adjusting for sociodemographics, diet, behavioral/lifestyle, and vascular risk factors.

Results: Of 2657 participants with dietary data, the mean sodium intake was 3031 ± 1470 mg/day (median, 2787; interquartile range, 1966-3815 mg/day). Participants who consumed ≥ 4000 mg/day sodium had an increased risk of stroke (hazard ratio, 2.59; 95% CI, 1.27-5.28) versus those who consumed ≤ 1500 mg/day with a 17% increased risk of stroke for each 500-mg/day increase (95% CI, 1.07-1.27).

Conclusions: High sodium intake was prevalent and associated with an increased risk of stroke independent of vascular risk factors. The new American Heart Association dietary sodium goals will help reduce stroke risk.