USA: Higher intake of sodium measured in 24-hour urine samples is associated in a dose-response manner with a higher cardiovascular risk, shows a recent study. Similarly, lower potassium intake and higher sodium-to-potassium ratio were also associated with greater risk.
The findings, published in the New England Journal of Medicine (NEJM), may support reducing sodium intake and increasing potassium intake from current levels.
The association between sodium intake and cardiovascular disease remains controversial, this in part may be due to inaccurate assessment of sodium intake. Assessing 24-hour urinary excretion over a period of multiple days seems to be an accurate method. Yuan Ma and the team, therefore, aimed to determine the relation between sodium intake and cardiovascular disease using 24-hour urinary excretion over a period of multiple days.
For this purpose, the researchers included individual-participant data from six prospective cohorts of generally healthy adults. Individual-participant data were included from six prospective cohorts of generally healthy adults. Sodium and potassium excretion was assessed with the use of at least two 24-hour urine samples per participant. The primary outcome was a cardiovascular event (coronary revascularization or fatal or nonfatal myocardial infarction or stroke).
Among 10,709 participants, who had a mean age of 51.5±12.6 years and of whom 54.2% were women, 571 cardiovascular events were ascertained during a median study follow-up of 8.8 years (incidence rate, 5.9 per 1000 person-years).
Key findings include:
The median 24-hour urinary sodium excretion was 3270 mg (10th to 90th percentile, 2099 to 4899).
Higher sodium excretion, lower potassium excretion, and a higher sodium-to-potassium ratio were all associated with a higher cardiovascular risk in analyses that were controlled for confounding factors.
In analyses that compared quartile 4 of the urinary biomarker (highest) with quartile 1 (lowest), the hazard ratios were 1.60 for sodium excretion, 0.69 for potassium excretion, and 1.62 for the sodium-to-potassium ratio.
Each daily increment of 1000 mg in sodium excretion was associated with an 18% increase in cardiovascular risk (hazard ratio, 1.18), and each daily increment of 1000 mg in potassium excretion was associated with an 18% decrease in risk (hazard ratio, 0.82).
"Higher sodium and lower potassium intakes, as measured in multiple 24-hour urine samples, were associated in a dose-response manner with a higher cardiovascular risk," wrote the authors. "These findings may support reducing sodium intake and increasing potassium intake from current levels."
Reference:
The study titled, "24-Hour Urinary Sodium and Potassium Excretion and Cardiovascular Risk," is published in the New England Journal of Medicine.
DOI: https://www.nejm.org/doi/full/10.1056/NEJMoa2109794