Joint association of urinary sodium and potassium excretion with cardiovascular events and mortality: prospective cohort study

OBJECTIVE: To evaluate the joint association of sodium and potassium urinary excretion (as surrogate measures of intake) with cardiovascular events and mortality, in the context of current World Health Organization recommendations for daily intake (<2.0 g sodium, >3.5 g potassium) in adults. DESIGN: International prospective cohort study. SETTING: 18 high, middle, and low income countries, sampled from urban and rural communities. PARTICIPANTS: 103 570 people who provided morning fasting urine samples. MAIN OUTCOME MEASURES: Association of estimated 24 hour urinary sodium and potassium excretion (surrogates for intake) with all cause mortality and major cardiovascular events, using multivariable Cox regression. A six category variable for joint sodium and potassium was generated: sodium excretion (low (<3 g/day), moderate (3-5 g/day), and high…