Associations of Usual 24-Hour Sodium and Potassium Intakes with Blood Pressure and Risk of Hypertension among Adults in China’s Shandong and Jiangsu Provinces

Background/Aims: High sodium intake and low intake of potassium can increase blood pressure (BP) and risk of developing hypertension. Few studies have examined the association between 24-h urinary sodium and potassium excretion and BP or risk of hypertension in China, and most used only a single 24-h urinary sample. Methods: We analyzed data on 2281 participants aged 18-69 years by using two 24-h urinary sodium and potassium excretions from the supplemental baseline survey of the Shandong- Ministry of Health Action on Salt Reduction and Hypertension (SMASH) project. We used measurement error models to estimate usual intakes, multivariable linear regression to assess their association with BP, and logistic regression to estimate the risk of hypertension. Results: The average usual intakes of sodium and potassium, and the mean sodium-potassium ratio, were 166.9 mmol/day, 25.3 mmol/day, and 6.8, respectively. All three measures were significantly associated with systolic BP (SBP) and diastolic BP (DBP), with an increase of 1.39 mmHg (95% confidence interval [CI] 0.44-2.34) in SBP and 0.94 mmHg (95% CI 0.34-1.55) in DBP for a 1-standard deviation (SD) (25.6mmol/day) increase in sodium intake, a decrease of 1.42 mmHg (95% CI -2.37- -0.47) in SBP and 0.91 mmHg (95% CI -1.52- -0.30) in DBP for a 1-SD (3.4 mmol/day) increase in potassium intake, and an increase of 0.97 mmHg (95% CI 0.36-1.58) in SBP and of 0.65 mmHg (95% CI 0.26-1.04) in DBP per unit increase in the sodium-to-potassium ratio. The adjusted odds ratios comparing the risk of hypertension among adults in the highest with those in the lowest quintile differ significantly for potassium (0.51; 95% CI 0.29-0.88) and sodium-to-potassium ratio (1.40; 95% CI 1.01-1.94). Conclusions: Our results suggested that higher sodium and lower potassium intakes are associated with increased BP and risk of hypertension in the Shandong and Jiangsu adults. (C) 2017 The Author(s) Published by S. Karger AG, Basel