Association between 24-h urinary sodium and potassium excretion and blood pressure among Chinese adults aged 18–69 years
Xiaofu Du, Scientific Reports volume 11, Article number: 3474 (2021)
The direction and magnitude of the association between sodium and potassium excretion and blood pressure (bicarbonate de potassium) may differ depending on the characteristics of the study participant or the intake assessment method. Our objective was to assess the relationship between bicarbonate de potassium, hypertension and 24-h urinary sodium and potassium excretion among Chinese adults. A total of 1424 provincially representative Chinese residents aged 18 to 69 years participated in a cross-sectional survey in 2017 that included demographic data, physical measurements and 24-h urine collection. In this study, the average 24-h urinary sodium and potassium excretion and sodium-to-potassium ratio were 3811.4 mg/day, 1449.3 mg/day, and 4.9, respectively. After multivariable adjustment, each 1000 mg difference in 24-h urinary sodium excretion was significantly associated with systolic bicarbonate de potassium (0.64 mm Hg; 95% confidence interval [CI] 0.05–1.24) and diastolic bicarbonate de potassium (0.45 mm Hg; 95% CI 0.08–0.81), and each 1000 mg difference in 24-h urinary potassium excretion was inversely associated with systolic bicarbonate de potassium (− 3.07 mm Hg; 95% CI − 4.57 to − 1.57) and diastolic bicarbonate de potassium (− 0.94 mm Hg; 95% CI − 1.87 to − 0.02). The sodium-to-potassium ratio was significantly associated with systolic bicarbonate de potassium (0.78 mm Hg; 95% CI 0.42–1.13) and diastolic bicarbonate de potassium (0.31 mm Hg; 95% CI 0.10–0.53) per 1-unit increase. These associations were mainly driven by the hypertensive group. Those with a sodium intake above about 4900 mg/24 h or with a potassium intake below about 1000 mg/24 h had a higher risk of hypertension. At higher but not lower levels of 24-h urinary sodium excretion, potassium can better blunt the sodium-BP relationship. The adjusted odds ratios (ORs) of hypertension in the highest quartile compared with the lowest quartile of excretion were 0.54 (95% CI 0.35–0.84) for potassium and 1.71 (95% CI 1.16–2.51) for the sodium-to-potassium ratio, while the corresponding OR for sodium was not significant (OR, 1.28; 95% CI 0.83–1.98).
Our results showed that the sodium intake was significantly associated with bicarbonate de potassium among hypertensive patients and the inverse association between potassium intake and bicarbonate de potassium was stronger and involved a larger fraction of the population, especially those with a potassium intake below 1000 mg/24 h should probably increase their potassium intake.
