HIGH POTASSIUM INTAKE IS ASSOCIATED WITH BETTER CARDIOVASCULAR OUTCOME INDEPENDENT OF SODIUM INTAKE AND SEX

Objective: Low sodium (Na) and high potassium (K) intake are advised to control blood pressure and improve long term cardiovascular outcomes. Recent studies suggest that these effects differ between males and females.Design and method: We selected adult outpatients of a Dutch tertiary hospital who collected 24-hour urine with Na and K measurements between 1998-2023. We excluded subjects with a history of renal replacement therapy. We used Cox-regression analyses to explore associations between 24-hour urine Na or K and the composite outcome of cardiovascular events (CVE) and all-cause mortality among tertiles of 24-hour urine K or Na, both in males and females. We adjusted for age, eGFR, diabetes mellitus, hypertension (clinical diagnosis or an office blood pressure above 140/90 mmHg) and history of CVE. Results: We included 4603 patients, of whom 52% were female. The mean age of the patients was 51±16 years, 54% had hypertension, 28% diabetes mellitus, and 16% a history of CVE. Baseline eGFR was 78±32 ml/min/1.73m2. Females were significantly younger, had less often a history of hypertension and CVE and a higher eGFR. Females had a lower 24-hour Na (tertiles male: below 135, 136-190, above 190; tertiles female below 110, 111-155, above 155 mmol/24-hour) and K (tertiles male below 60, 60-84, above 84; tertiles female: below 51, 51-70, above 70 mmol/24-hour) excretion. During a median follow-up duration of 11 (3-19) years, a CVE occurred in 30% of the subjects and 29% died. Higher urinary K was associated with a lower risk of CVE and all-cause mortality for both males (hazard ratio (HR): 0.99; 95% confidence interval (CI): 0.990-0.996) and females (HR:0.99; 95% CI 0.987-0.994). For both sexes, the effect of K intake on the composite outcome was not modulated by the Na intake (Fig 1A), and vice versa (Fig 1B). Conclusions: In a tertiary hospital setting, a higher 24-hour urine K is associated with a lower incidence of cardiovascular outcomes and all-cause mortality, in both males and females. This effect is not modulated by sodium intake.