Spot Urine Sodium-to-Potassium Ratio Is a Predictor of Stroke: The MESA

• Published in: Stroke (1970) 2019-02, Vol.50 (2), p.321-327
• Main Authors: Averill, Michelle M, Young, Rebekah L, Wood, Alexis C, Kurlak, Emily O, Kramer, Holly, Steffen, Lyn, McClelland, Robyn L, Delaney, Joseph A, Drewnowski, Adam
• Format: Article
• Language: English
• ISSN: 0039-2499; 1524-4628
• DOI: 10.1161/STROKEAHA.118.023099

BACKGROUND AND PURPOSE—Dietary sodium reduction with concurrent increase in potassium intake is a current public health priority to reduce risk of cardiovascular events. This study explored associations between the spot urine sodium-to-potassium ratio and cardiovascular events in the MESA (Multi-Ethnic Study of Atherosclerosis) longitudinal cohort. METHODS—The MESA is a prospective cohort study of 6814 adults from 4 ethnic groups (European-, Asian-, African- and Hispanic-American) with a mean age of 62 (±10.2) years and an average of 11.7 (±2.2) years of follow-up. Participants were free of clinical cardiovascular disease at baseline. Spot urine sodium and potassium excretion, as a marker of dietary intake, was collected at baseline. The impact of urinary sodium-to-potassium ratio on adjudicated cardiovascular events was assessed using Cox proportional hazards models. RESULTS—Only 39% of MESA participants had a urinary sodium-to-potassium ratio ≤1, and these participants experienced only 74 of the 236 strokes. A sodium-to-potassium ratio >1 was associated with a hazard ratio of 1.47 (95% CI,1.07–2.00) for risk of stroke, adjusting for age, sex, race, cardiovascular risk factors, socio-demographic characteristics, body size, and kidney function. CONCLUSIONS—The spot urine sodium-to-potassium ratio (measurable in routine care) is associated with stroke. A urine sodium-to-potassium ratio of ≤1, may be related to a clinically relevant reduction in stroke risk and is a feasible target for health interventions.