Urinary Sodium and Potassium Excretion, Mortality, and Cardiovascular Events

N Engl J Med. 2014 Aug 14;371(7):612-23. doi: 10.1056/NEJMoa1311889.

Abstract

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. (Funded by the Population Health Research Institute and others.).

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cardiovascular Diseases / epidemiology*
  • Cardiovascular Diseases / etiology
  • Diet*
  • Female
  • Follow-Up Studies
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Mortality*
  • Potassium / administration & dosage
  • Potassium / urine*
  • Sodium / urine*
  • Sodium, Dietary / administration & dosage*
  • Sodium, Dietary / adverse effects

Substances

  • Sodium, Dietary
  • Sodium
  • Potassium

Grant support