Twenty-Four-Hour Urinary Sodium and Potassium Excretion in China: A Systematic Review and Meta-Analysis

Background In China, high sodium and low potassium intakes result in elevated blood pressure, a major cause of cardiovascular disease, yet the intake estimates lack accuracy and nutritional strategies remain limited. Methods and Results We aimed to determine sodium and potassium intake by systematically searching for and quantitatively summarizing all published 24-hour urinary sodium and potassium data (ie, the most accurate method). MEDLINE , EMBASE , Scopus, China National Knowledge Infrastructure, and Wanfang were searched up to February 2019. All studies reporting 24-hour urinary sodium or potassium in China were included; hospitalized patients were excluded. Data were pooled using random-effects meta-analysis and heterogeneity was explored with meta-regression. Sodium data were reported in 70 studies (n=26 767), 59 of which also reported potassium (n=24 738). Mean sodium and potassium excretions were 86.99 mmol/24 h (95% CI , 69.88-104.10) and 14.65 mmol/24 h (95% CI , 11.10-18.20) in children aged 3 to 6 years, 151.09 mmol/24 h (95% CI , 131.55-170.63) and 25.23 mmol/24 h (95% CI , 22.37-28.10) in children aged 6 to 16 years, and 189.07 mmol/24 h (95% CI , 182.14-195.99) and 36.35 mmol/24 h (95% CI , 35.11-37.59) in adults aged >16 years. Compared with southern China, sodium intake was higher in northern China ( P<0.0001) but is declining ( P=0.0066). Conclusions Average sodium intake in all age groups across China is approximately double the recommended maximum limits, and potassium intake is less than half that recommended. Despite a decline, sodium intake in northern China is still among the highest in the world, and the North-South divide persists. Urgent action is needed to simultaneously reduce sodium and increase potassium intake across China.