Association of a Province-Wide Intervention With Salt Intake and Hypertension in Shandong Province, China, 2011-2016.

Importance High salt intake is associated with hypertension, which is a leading modifiable risk factor for cardiovascular disease. Objective To assess the association of a government-led, multisectoral, and population-based intervention with reduced salt intake and blood pressure in Shandong Province, China. Design, Setting, and Participants This cross-sectional study used data from the Shandong-Ministry of Health Action on Salt and Hypertension (SMASH) program, a 5-year intervention to reduce sodium consumption in Shandong Province, China. Two representative samples of adults (aged 18-69 years) were surveyed in 2011 (15350 preintervention participants) and 2016 (16490 postintervention participants) to examine changes in blood pressure, and knowledge, attitudes, and behaviors related to sodium intake. Urine samples were collected from random subsamples (2024 preintervention participants and 1675 postintervention participants) for measuring sodium and potassium excretion. Data were analyzed from January 20, 2017, to April 9, 2019. Interventions Media campaigns, distribution of scaled salt spoons, promotion of low-sodium products in markets and restaurants, and activities to support household sodium reduction and school-based sodium reduction education. Main Outcomes and Measures The primary outcome was change in urinary sodium excretion. Secondary outcomes were changes in potassium excretion, blood pressure, and knowledge, attitudes, and behaviors. Outcomes were adjusted for likely confounders. Means (95% CIs) and percentages were weighted. Results Among 15350 participants in 2011, 7683 (50.4%) were men and the mean age was 40.7 years (95% CI, 40.2-41.2 years); among 16490 participants in 2016, 8077 (50.7%) were men and the mean age was 42.8 years (95% CI, 42.5-43.1 years). Among participants with 24-hour urine samples, 1060 (51.8%) were men and the mean age was 40.9 years (95% CI, 40.5-41.3 years) in 2011 and 836 (50.7%) were men and the mean age was 40.7 years (95% CI, 40.1-41.4 years) in 2016. The 24-hour urinary sodium excretion decreased 25% from 5338 mg per day (95% CI, 5065-5612 mg per day) in 2011 to 4013 mg per day (95% CI, 3837-4190 mg per day) in 2016 (P < .001), and potassium excretion increased 15% from 1607 mg per day (95% CI, 1511-1704 mg per day) to 1850 mg per day (95% CI, 1771-1929 mg per day) (P < .001). Adjusted mean systolic blood pressure among all participants decreased from 131.8 mm Hg (95% CI, 129.8-133.8 mm Hg) to 130.0 mm Hg (95% CI, 127.7-132.4 mm Hg) (P = .04), and diastolic blood pressure decreased from 83.9 mm Hg (95% CI, 82.6-85.1 mm Hg) to 80.8 mm Hg (95% CI, 79.4-82.1 mm Hg) (P < .001). Knowledge, attitudes, and behaviors associated with dietary sodium reduction and hypertension improved significantly. Conclusions and Relevance The findings suggest that a government-led and population-based intervention in Shandong, China, was associated with significant decreases in dietary sodium intake and a modest reduction in blood pressure. The results of SMASH may have implications for sodium reduction and blood pressure control in other regions of China and worldwide. Question Was a government-led, multisectoral, province-wide intervention associated with reduced sodium intake and blood pressure in Shandong Province, China, from 2011 to 2016? Findings In this cross-sectional study of 15350 preintervention participants and 16490 postintervention participants, 24-hour urinary sodium excretion based on the subsamples of total preintervention and postintervention survey samples decreased 25% from before to after implementation of the intervention. Systolic and diastolic blood pressure decreased significantly. Meaning The findings suggest that this population-based intervention was associated with lower urinary sodium excretion and blood pressure in a large population in China. This cross-sectional study evaluates the change in urinary sodium excretion and other factors associated with blood pressure during a government-led, multisectoral, province-wide 5-year intervention in Shandong Province, China, from 2011 to 2016.