U-Shaped Association for Sodium Intake, Mortality
(HealthDay News) – Low and high sodium intake are associated with increased mortality, according to a meta-analysis published online March 20 in the American Journal of Hypertension.
Niels Graudal, MD, from Copenhagen University Hospital in Denmark, and colleagues conducted a meta-analysis to examine the correlation between sodium exposure and incidence of all-cause mortality (ACM) and cardiovascular disease events (CVDEs). Data were included from 23 cohort studies and two follow-up studies of randomized clinical trials, involving 274,683 individuals. Dietary intake of sodium was classified as low (<115mmol), usual (low usual: 115–165mmol; high usual: 166–215mmol), and high (>215mmol).
The researchers found that the risks of ACM and CVDEs were reduced in usual vs. low sodium intake (hazard ratio [HR], 0.91 [95% confidence interval (CI), 0.82–0.99] and 0.9 [95% CI, 0.82–0.99], respectively) and were elevated in high vs. usual sodium intake (HR, 1.16 [95% CI, 1.03–1.3] and 1.12 [95% CI, 1.02–1.24], respectively). After adjustment for multiple confounders there was a consistent decrease in ACM risk for usual vs. low sodium intake (HR, 0.86; 95% CI, 0.81–0.92), but no consistent increase was seen with high vs. usual sodium intake (HR, 1.04; 95% CI, 0.91–1.18). The number of events was stable within the usual sodium intake range (high usual vs. low usual sodium: HR, 0.98; 95% CI, 0.92–1.03).
"Both low sodium intakes and high sodium intakes are associated with increased mortality, consistent with a U-shaped association between sodium intake and health outcomes," the authors write.