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

Abstract

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 B P, 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.

Paucity of high‐quality studies reporting on salt and health outcomes from the science of salt: A regularly updated systematic review of salt and health outcomes (April 2017 to March 2018)

“…Identified studies were meta‐analyses (n = 1), RCTs (n = 3), prospective cohort studies (n = 4), retrospective case–control studies (n = 1), cross‐sectional studies (n = 27), case–control studies (n = 1), post hoc analyses of RCTs (n = 2), and quasi‐experimental studies (n = 3). Three studies assessed morbidity outcomes, two studies assessed outcomes related to symptoms/quality of life/functional status, 31 studies assessed clinically relevant surrogate outcomes, including 26 that assessed blood pressure outcomes, and six studies assessed physiologic outcomes . Of these studies, only three studies met the minimum methodological criteria for detailed critical appraisal (Table ).…”

Mineral Intake Ratios Are a Weak but Significant Factor in Blood Pressure Variability in US Adults

“…Consistent with our findings, using urinary excretion rates as a biomarker for sodium intakes, a lower sodium to potassium intake ratio showed a stronger relation with lower BP than either nutrient alone ( 32 , 33 ). More recently in Shandong and Jiangsu, China, in adults, increased sodium intakes, sodium-to-potassium intake ratio, and reduced potassium intakes were associated with higher BP ( 34 ). Considering additional minerals or their ratios together had minor contributions for explaining the variance in BP by sodium:potassium alone in our study.…”

Assessment and validation of spot urine in estimating the 24-h urinary sodium, potassium, and sodium/potassium ratio in Chinese adults

“…The completeness of 24-h urine collection was defined by urine volume and urinary creatinine. A 24-h urinary volume less than 500 ml or a 24-h urinary creatinine volume that was ±2 standard deviations (SD) outside of the sex-specific mean were considered incomplete [15].…”