Urinary sodium and potassium excretion, mortality, and cardiovascular events

• Published in: New England Journal of Medicine
• Main Author: O'Donnell M.; Mente A.; Rangarajan S.; McQueen M.J.; Wang X.; Liu L.; Yan H.; Lee S.F.; Mony P.; Devanath A.; Rosengren A.; Lopez-Jaramillo P.; Diaz R.; Avezum A.; Lanas F.; Yusoff K.; Iqbal R.; Ilow R.; Mohammadifard N.; Gulec S.; Yusufali A.H.; Kruger L.; Yusuf R.; Chifamba J.; Kabali C.; Dagenais G.; Lear S.A.; Teo K.; Yusuf S.
• Format: Article
• Language: English
• Published: Massachussetts Medical Society 2014
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84906080079&doi=10.1056%2fNEJMoa1311889&partnerID=40&md5=428bb003cbc46430a74028447ea5ded8

BACKGROUND: The optimal range of sodium intake for cardiovascular health is controversial. METHODS: We obtained morning fasting urine samples from 101,945 persons in 17 countries and estimated 24-hour sodium and potassium excretion (used as a surrogate for intake). We examined the association between estimated urinary sodium and potassium excretion and the composite outcome of death and major cardiovascular events. RESULTS: The mean estimated sodium and potassium excretion was 4.93 g per day and 2.12 g per day, respectively. With a mean follow-up of 3.7 years, the composite outcome occurred in 3317 participants (3.3%). As compared with an estimated sodium excretion of 4.00 to 5.99 g per day (reference range), a higher estimated sodium excretion (≥7.00 g per day) was associated with an increased risk of the composite outcome (odds ratio, 1.15; 95% confidence interval [CI], 1.02 to 1.30), as well as increased risks of death and major cardiovascular events considered separately. The association between a high estimated sodium excretion and the composite outcome was strongest among participants with hypertension (P=0.02 for interaction), with an increased risk at an estimated sodium excretion of 6.00 g or more per day. As compared with the reference range, an estimated sodium excretion that was below 3.00 g per day was also associated with an increased risk of the composite outcome (odds ratio, 1.27; 95% CI, 1.12 to 1.44). As compared with an estimated potassium excretion that was less than 1.50 g per day, higher potassium excretion was associated with a reduced risk of the composite outcome. CONCLUSIONS: In this study in which sodium intake was estimated on the basis of measured urinary excretion, an estimated sodium intake between 3 g per day and 6 g per day was associated with a lower risk of death and cardiovascular events than was either a higher or lower estimated level of intake. As compared with an estimated potassium excretion that was less than 1.50 g per day, higher potassium excretion was associated with a lower risk of death and cardiovascular events. Copyright © 2014 Massachusetts Medical Society.