Dietary salt reduction initiative effective, with modest BP benefits
A province-wide campaign to reduce salt intake in Shandong, China, resulted in significant decreases in dietary sodium, modest reductions in BP and improved attitude and knowledge about salt intake among participants.
According to a report on the Shandong Ministry of Health Action on Salt and Hypertension (SMASH) program published in JAMA Internal Medicine, government-led interventions for salt intake reduction were conducted in Shandong that included media campaigns, the distribution of scaled salt spoons, promotion of low-sodium foods, promotion of activities to support household sodium lowering, and school-based sodium reduction education between 2011 and 2016.
Among a subgroup of participants (2011: n = 2,024; mean age, 41 years; 50% men; 2016: n = 1,675; mean age, 43 years; 51% men), investigators used 24-hour urine samples to measure changes in sodium and potassium excretion.
For the total cohort (2011, n = 15,350; mean age, 41 years; 52% men; 2016, n = 16,490; mean age 41 years; 51% men), investigators measured changes in BP and sodium via examination and knowledge and behaviors via self-reported responses to survey questions.
Researchers observed a 25% reduction (P < .001) in 24-hour urinary sodium excretion between 2011 (5,338 mg per day; 95% CI, 5,065-5,612) and 2016 (4,013 mg per day; 95% CI, 3,837-4,190).
Additionally, researchers reported a 15% increase in potassium excretion (P < .001) during the same period (2011: 1,607 mg per day; 95% CI, 1,511-1,704; 2016, 1,850 mg per day; 95% CI, 1,771-1,929).
Among the overall cohort, mean systolic BP decreased from 131.8 mm Hg to 130 mm Hg (P = .04), and diastolic BP decreased from 83.9 mm Hg to 80.8 mm Hg (P < .001), according to the study.
“The SMASH program showed that a comprehensive, population-based intervention with strong government support was associated with a substantial decrease in urinary sodium excretion and a modest reduction in BP,” Aiqiang Xu, PhD, of the Shandong Center for Disease Control and Prevention and the Academy of Preventive Medicine at Shandong University in Jinan, China, and colleagues wrote. “The findings should be verified in other populations and periods. In particular, the value of such interventions compared with many potentially good interventions that could be considered at the population level merits more investigation.”
Behavioral and educational impact
In other findings, the proportion of participants with knowledge of the Chinese Dietary Guidelines recommendation for dietary sodium increased from 31.7% in 2011 (95% CI, 23.3-40.1) to 57.6% in 2016 (95% CI, 48.3-66.9).
Researchers also observed improvements in self-reported scaled salt spoon use (2011: 14.6%; 95% CI, 8.7-20.6; 2016: 36.1%; 95% CI, 28.4-43.8), greater attention to food labeling (2011: 18.4%; 95% CI, 12.5-24.2; 2016: 32.1%; 95% CI, 25.9-38.2) and more actions taken to reduce dietary sodium intake (2011: 35.7%; 95% CI, 28.6-42.8; 2016: 61.1%; 95% CI, 52.8-69.5).
“In 2013, the World Health Organization member states established a global target of 25% reduction in hypertension prevalence and 30% reduction in mean population sodium intake by 2025,” the researchers wrote. “Several countries have adopted national sodium reduction strategies. The findings from the SMASH program compared favorably with successful sodium reduction efforts in other countries.”
Significance for policymakers
“Policymakers in other regions of the world might consider following this approach for designing and implementing population-wide, health behavior-modifying strategies for other types of lifestyle intervention,” Tracy Y. Wang, MD, MHS, MSc, associate professor of medicine, member in the Duke Clinical Research Institute and director of health services and outcomes research at the Duke University School of Medicine, wrote in a related editorial. “Population-based approaches are more likely to achieve broad-based goals and reduce social inequities compared with interventions that target certain at-risk groups.” – by Scott Buzby
Disclosures: One author reports receiving grants from the China Ministry of Science and Technology and the Chongqing Jiankangyuan Company. The other authors report no relevant financial disclosures. Wang reports she received grants and personal fees from AstraZeneca and Cryolife; grants from Bristol-Myers Squibb, Chiesi Farmaceutici SpA, Merck, Portola and Regeneron; and personal fees from Sanofi.