Sodium excretion and risk of developing coronary heart disease

Abstract

Background: Despite compelling evidence for sodium's adverse effects on blood pressure, it remains uncertain whether excess sodium intake is a risk factor for coronary heart disease (CHD) in the overall population and in potentially more susceptible subgroups.

Methods and results: We prospectively followed 7543 adults aged 28 to 75 years and free of cardiovascular and kidney disease in 1997/1998 of the Prevention of Renal and Vascular End-stage Disease (PREVEND) study. Sodium excretion was measured in two 24-hour urine collections at baseline. Potential susceptibility factors were blood pressure and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP). Median 24-hour sodium excretion was 137 mmol (Q1-Q3, 106-171 mmol). During a median follow-up of 10.5 (Q1-Q3: 9.9-10.8) years, 452 CHD events occurred. In the entire cohort, there was no association between each 1-g/d (43 mmol/24 h) increment in sodium excretion and CHD risk (adjusted hazard ratio, 1.07; 95% confidence interval, 0.98-1.18; P=0.15). However, the association of sodium excretion with CHD risk tended to be modified by mean arterial pressure (Pinteraction=0.08) and was modified by NT-proBNP (Pinteraction=0.002). When stratified, each 1-g/d increment in sodium excretion was associated with an increased risk for CHD in subjects with hypertension (adjusted hazard ratio, 1.14; 95% confidence interval, 1.01-1.28; n=2363) and in subjects with NT-proBNP concentrations above the sex-specific median (adjusted hazard ratio, 1.16; 95% confidence interval, 1.03-1.30; n=3771).

Conclusions: Overall, there was no association between sodium excretion and risk of CHD. The association between sodium excretion and CHD risk was modified by NT-proBNP. Higher sodium excretion was associated with an increased CHD risk among subjects with increased NT-proBNP concentrations or with hypertension.

Keywords: diet; epidemiology; heart diseases; natriuretic peptides; nutrition assessment; sodium; urine specimen collection.