Associations of 24-Hour Urinary Sodium, Potassium Excretion and Sodium-to-Potassium Ratio With Longitudinal Home...

Dietary sodium and potassium intake are key determinants of blood pressure (BP) control in hypertensive patients. However, their associations with longitudinal home BP control in patients with apparent treatment-resistant hypertension (aTRH) remain unclear. In this prospective cohort study, baseline 24-hour urinary sodium and potassium excretion, objective biomarkers of dietary sodium and potassium intake, as well as urinary sodium-to-potassium (Na/K) ratio were evaluated as exposure variables. The primary outcome was longitudinal home BP control during follow-up. Mixed-effects models were used to assess these associations. A total of 172 patients were followed for a median of 39.3 months, contributing 7547 morning and 6640 evening home BP measurements. After multivariable adjustment, each 1-standard deviation (SD) increase in urinary sodium excretion (99.49 mmol) was associated with poorer home systolic BP (SBP) control (morning: odds ratio [OR] 0.59, 95% confidence interval [CI] 0.38-0.89; evening: OR 0.65, 95% CI 0.44-0.96). Each 1-SD increase in the urinary Na/K ratio (1.98 units) was associated with poorer morning (OR 0.68, 95% CI 0.48-0.97) and evening home SBP control (OR 0.69, 95% CI 0.51-0.94). A higher Na/K ratio was also associated with poorer overall evening home BP control (OR 0.73, 95% CI 0.54-0.98). Consistent associations were observed when BP was analyzed as a continuous outcome. Urinary potassium excretion alone was not significantly associated with home BP control. Dietary sodium restriction and maintenance of sodium-potassium balance may represent important strategies for improving home BP control in patients with aTRH. Trial Registration: Not applicable. This study was a prospective observational cohort study with no assignment of participants to any intervention; thereby clinical trial registration was not required.