Patients with rheumatoid arthritis (RA) are at increased cardiovascular risk. The urinary sodium-to-potassium ratio has emerged as a simple marker of diet quality and a potentially reliable index for cardiovascular risk assessment. A cross-sectional study published in Clinical Rheumatology, evaluated its association with myocardial health in RA.

The study included 61 patients with RA. Sodium and potassium intake were assessed from 24-hour urine samples, and the urinary sodium-to-potassium ratio was calculated. Myocardial perfusion was measured using the subendocardial viability ratio (SEVR) with applanation tonometry. Pulse wave velocity and augmentation index were assessed as measures of arterial stiffness with the same device.

Only two patients had an optimal sodium-to-potassium ratio of ≤1. Urinary sodium excretion was significantly associated with high-density lipoprotein cholesterol and uric acid. Potassium excretion correlated positively with estimated glomerular filtration rate (eGFR) and negatively with disease activity and inflammatory load. Both urinary sodium excretion and sodium-to-potassium ratio showed significant inverse correlations with SEVR after adjustment for other variables. No associations were found between arterial stiffness measures and sodium, potassium, or their ratio.