Abstract 10005: Sodium Intake and Risk of Cardiovascular Disease: A Pooled Analysis of Individual Data from Six Cohort Studies with Multiple 24-Hour Urine Collections

Background: The relationship between sodium intake and cardiovascular disease (CVD) remains controversial, in part, due to inaccurate assessment of sodium intake. 24-hour urinary excretion over multiple days is considered the optimal method. Methods: We included individual participant data from 6 prospective cohorts among generally healthy adults with sodium and potassium excretion assessed by at least two 24-hour urine collections. Out of 10,709 participants (54% women; mean [SD] age, 51.5 [12.6] years), 571 incident CVD events (including myocardial infarction, coronary revascularization, and stroke) were ascertained during a median follow-up of 8.8 years. We analyzed each cohort using consistent methods and combined the results using random-effects meta-analysis. Results: Median 24-hour urinary sodium excretion (10 th -90 th percentile) was 3,270 (2,099-4,899) mg. Higher sodium excretion, lower potassium excretion and higher sodium-to-potassium ratio were all associated with higher risk of CVD events after controlling for confounding factors (all P values for trend≤0.02); there was no evidence of nonlinearity. The hazard ratio [HR] comparing top with bottom quartiles was 1.67 [95% confidence interval [CI]: 1.21-2.30] for sodium, 0.77 [0.57-1.02] for potassium and 1.72 [1.27-2.32] for sodium-to-potassium ratio. Each 1,000 mg/d increment in sodium excretion was associated with an 18% increase in CVD risk (95%CI: 5%-32%) and each 1,000 mg/d increment in potassium excretion was associated with 18% lower risk (95%CI: 6%-28%). Conclusions: Higher sodium and lower potassium intakes, measured in multiple 24-hour urine samples, were associated with higher risk of CVD in a dose-response manner. These findings support current recommendations to reduce sodium and increase potassium intakes.