A large-scale cluster randomized trial to determine the effects of community-based dietary sodium reduction—the China Rural Health Initiative Sodium Reduction Study

Abstract

Background Cardiovascular diseases are the leading cause of death and disability in China. High blood pressure caused by excess intake of dietary sodium is widespread and an effective sodium reduction program has potential to improve cardiovascular health. Design This study is a large-scale, cluster-randomized, trial done in five Northern Chinese provinces. Two counties have been selected from each province and 12 townships in each county making a total of 120 clusters. Within each township one village has been selected for participation with 1:1 randomization stratified by county. The sodium reduction intervention comprises community health education and a food supply strategy based upon providing access to salt substitute. Subsidization of the price of salt substitute was done in 30 intervention villages selected at random. Control villages continued usual practices. The primary outcome for the study is dietary sodium intake level estimated from assays of 24 hour urine. Trial status The trial recruited and randomized 120 townships in April 2011. The sodium reduction program was commenced in the 60 intervention villages between May and June of that year with outcome surveys scheduled for October to December 2012. Baseline data collection shows that randomisation achieved good balance across groups. Discussion The establishment of the China Rural Health Initiative has enabled the launch of this large-scale trial designed to identify a novel, scalable strategy for reduction of dietary sodium and control of blood pressure. If proved effective, the intervention could plausibly be implemented at low cost in large parts of China and other countries worldwide.

Joint association of urinary sodium and potassium excretion with cardiovascular events and mortality: prospective cohort study

“…A small cluster randomised controlled trial (five centres), which replaced table salt with low sodium salt substitute (partially replaced with potassium chloride) reported a reduced cardiovascular risk in those centres randomised to salt substitution, although findings were not conclusive owing to methodological limitations of the trial 41. An ongoing large cluster randomised controlled trial in China, evaluating the use of salt substitutes (potassium chloride substituted for sodium chloride) is expected to provide a more definitive answer 42. However, these trials evaluate simultaneous increased potassium intake with a reduction of high sodium intake to moderate intake levels, and it is unlikely to inform whether a very low sodium intake (<2.0 g/day) is beneficial or harmful.…”

Estimating daily salt intake based on 24 h urinary sodium excretion in adults aged 18–69 years in Shandong, China

“…Such public health approaches can be simple, at low cost and effective. Indeed, campaigns such as the SMASH and the China Rural Health Initiative Sodium Reduction Study are already underway 23. As reported by Yan et al ,24 in China, measures for salt reduction will include government initiatives, health education and promotion, promotion of low sodium salt in food processing companies and restaurants.…”

Innovative and Collaborative Strategies to Reduce Population-Wide Sodium Intake

“…Salt substitution was found to be a feasible and successful dietary approach for reducing salt intake in Chinese populations [24,25], which could greatly help reduce the estimated 1 million rural Chinese suffering a stroke each year [24]. An ongoing large-scale trial will evaluate the combined effect of health education and access to a salt substitute [43] and, importantly, assess the cost effectiveness of such a strategy for large parts of China. While replacement of table salt with salt substitutes involves individual behavior changes, where promoted and subsidized by governments it could also be considered a population-level strategy.…”