Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2025 Jan 27;23(1):41.
doi: 10.1186/s12916-025-03868-8.

Persistent effect of salt reduction in schoolchildren and their families: 1-year follow-up after an application-based cluster randomized controlled trial

Yuan Li  1   2 , Puhong Zhang  3   4   5 , Feng J He  6 , Rong Luo  1 , Jing Song  6 , Changqiong Wang  6 , Fengge Chen  7 , Wei Zhao  7 , Yuhong Zhao  8 , Hang Chen  9 , Tianyong Wu  9 , Xiaoyan Wang  9 , Hui Zhou  10 , Zhi Han  10 , Jie Zhang  10
Affiliations
Randomized Controlled Trial

Persistent effect of salt reduction in schoolchildren and their families: 1-year follow-up after an application-based cluster randomized controlled trial

Yuan Li et al. BMC Med. .

Abstract

Background: A 12-month cluster randomized controlled trial (RCT) demonstrated the effectiveness of an application-based education program in reducing the salt intake and systolic blood pressure (SBP) of schoolchildren's adult family members. This study aimed to assess whether the effect at 12 months persisted at 24 months.

Methods: Fifty-four schools were randomly assigned to either the intervention or control group. All participants (594 children in grade 3 and 1188 of their adult family members) who completed the baseline survey were contacted again 12 months after the trial. The primary outcome was the difference in salt intake change between the intervention and control groups at 24 months versus baseline and 12 months, measured by the mean two consecutive 24-h urinary sodium excretions. The secondary outcome was the difference in the change of blood pressure and salt-related Knowledge, Attitude, Practice (KAP) score.

Results: The difference in salt intake change in adults between the intervention and control groups after adjusting for confounding factors was - 0.38 g/day at 24 months versus baseline (95% CI - 0.81 to 0.05, p = 0.09), following the - 0.83 g/day (95% CI - 1.25 to - 0.41, p < 0.001) at 12 months. The adjusted difference in SBP change was - 2.19 mm Hg (95% CI - 3.63 to - 0.76, p = 0.003) at 24 months versus baseline, following the - 1.80 mm Hg (95% CI - 3.19 to - 0.40, p = 0.01) at 12 months. The intervention group had a higher KAP score than the control group both at 12 months and at 24 months versus baseline. No significant changes were found in children.

Conclusions: The effect of the education program on adults' salt intake faded, but the SBP lowering effect and the improvement of KAP score remained 12 months after the completion of the RCT. Continuous efforts are needed to maintain the salt reduction effects in real-world settings.

Trial registration: ChiCTR1800017553. Registered on August 3, 2018.

Keywords: Blood pressure; Follow-up; Persistent effect; Salt reduction.

PubMed Disclaimer

Conflict of interest statement

Declarations. Ethics approval and consent to participate: The study was approved by the Queen Mary (University of London) Ethics of Research Committee (QMERC2018/13) and the Peking University Institutional Review Board in China (IRB00001052-18051). Permissions were obtained from the local education authorities and school headteachers. All participants who took part in the outcome assessments gave written informed consent. For children, participant assent and parental written consent were obtained. Consent for publication: Not applicable. Competing interests: FJH is an unpaid member of Action on Salt and World Action on Salt, Sugar and Health (WASSH); no other relationships or activities that could appear to have influenced the submitted work. All other authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Flowchart of participants
Fig. 2
Fig. 2
Unadjusted average salt intake and systolic blood pressure by visit and group in adults and children
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Huang L, Trieu K, Yoshimura S, Neal B, Woodward M, Campbell NRC, et al. Effect of dose and duration of reduction in dietary sodium on blood pressure levels: systematic review and meta-analysis of randomised trials. BMJ. 2020;368: m315. 10.1136/bmj.m315. - PMC - PubMed
    1. Ma Y, He FJ, Sun Q, Yuan C, Kieneker LM, Curhan GC, et al. 24-hour urinary sodium and potassium excretion and cardiovascular risk. N ENGL J MED. 2022;386:252–63. 10.1056/NEJMoa2109794. - PMC - PubMed
    1. Murray CJL, Aravkin AY, Zheng P, Abbafati C, Abbas KM, Abbasi-Kangevari M, et al. Global burden of 87 risk factors in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. The Lancet. 2020;396:1223–49. 10.1016/s0140-6736(20)30752-2. - PMC - PubMed
    1. World Health Organization. Tackling NCDs: “best buys” and other recommended interventions for the prevention and control of noncommunicable diseases. https://www.who.int/publications/i/item/WHO-NMH-NVI-17.9. Accessed 26 October 2017.
    1. World Health Organization. WHO global report on sodium intake reduction. https://www.who.int/publications-detail-redirect/97892400699859. Accessed 9 March 2023.

Publication types

Substances

LinkOut - more resources