#1575 Higher dietary potassium intake and a lower dietary Na/K ratio are associated with a lower incidence of new-onset hypertension

Abstract Background and Aims A diet high in potassium (K) and low in sodium (Na) has been associated with lower blood pressure in the general population. With the advent of potassium-rich salt substitutes it is of interest to investigate how dietary Na and K intake interact in the setting of hypertension prevention. For this purpose, the 24-hour urine Na/K-ratio could be of added value. Method We selected adult outpatients of a Dutch tertiary hospital who collected 24-hour urine with Na and K measurements, as a proxy for dietary intake, between 1998–2023. We excluded subjects with a history of renal replacement therapy or hypertension (clinical diagnosis or an office blood pressure of >140/90 mmHg). We used Cox-regression analyses to explore the association between 24-hour urine Na, K or Na/K-ratio and new-onset hypertension. We adjusted for age, sex, diabetes mellitus, history of cardiovascular events and estimated glomerular filtration rate (eGFR). Results We included 2104 patients, of whom 54% were female. The mean age of the patients was 46 ± 15 years, 22% had diabetes mellitus, and 9% a history of CVE. Baseline eGFR was 90 ± 29 ml/min/1.73 m². Mean 24-h urine Na was 155 ± 70 mmol/24 h, K was 69 ± 27 mmol/24h and the Na/K-ratio 2.4 ± 1.2 mmol/mmol. During a median follow-up duration of 12 (2–20) years, hypertension was diagnosed in 32%. Higher 24-hour urine K was associated with a 22% lower risk (HR 0.78 per standard deviation (SD) change, 95% CI 0.95–0.87, p-value < 0.001) for new-onset hypertension, whereas 24-hour urinary Na was not associated with the composite outcome (HR 0.93 per SD change, 95% CI 0.93–1.07, p-value = 0.37). A higher 24-hour urine Na/K ratio was associated with a 19% (HR 1.19 per SD change, 95% CI 1.12–1.28, p-value < 0.001) for new-onset hypertension. Conclusion Higher 24-hour urine K and a lower 24-hour urine Na/K-ratio are associated with a lower incidence of new-onset hypertension. These data support the notion that high potassium intake contributes to the prevention of hypertension in the outpatient setting.