A school-based education programme to reduce salt intake in children and their families

Lead Research Organisation: Queen Mary, University of London
Department Name: Wolfson Institute

Abstract

Cardiovascular disease (i.e. strokes, heart attacks and heart failure) is the leading cause of death and disability worldwide. Raised blood pressure is a major cause of cardiovascular disease, accounting for 62% of strokes and 49% of heart attacks. Dietary salt intake is the major factor that increases blood pressure and is largely responsible for the rise in blood pressure with age.

Although cardiovascular events occur most frequently after the age of 40 years and the prevalence of hypertension is very low in children, the origins of hypertension and cardiovascular disease occur in childhood. Accordingly, the greatest long-term potential to reduce these conditions is to initiate prevention activities in youth. Such a public heath strategy aimed at preventing or slowing the progression of rising blood pressure altogether would have enormous benefits.

Previous studies have demonstrated that salt intake plays an important role in regulating blood pressure in children. A lower salt diet in children could prevent the development of hypertension and cardiovascular disease later in life.

Despite the evidence above, there is no reliable data on how much salt children are eating now and no strategy on how to keep children on a low salt intake.

We propose to carry out a cross-sectional study to determine the current salt intake in children by using the gold standard method, i.e. measuring 24-h urinary sodium. Furthermore, we will carry out a randomised trial to determine whether an education programme targeted at school children can lower salt intake in children and their families.

Our study will be carried out in China which is the largest low- and middle-income country in the world. The successful completion of our study will be the start of a national salt reduction programme which will reduce salt intake both in children and in adults. Furthermore, our salt reduction programme could be adopted by many other low- and middle-income countries. A modest reduction in salt intake across the whole population will lower population blood pressure and prevent many thousands of strokes, heart attacks and heart failure each year, and also lead to major cost-savings to individuals, their families and the health services.

Technical Summary

The first phase of our proposal is to carry out a cross-sectional study in 400 primary school children with age of 7 to 11 years, to assess salt intake by measuring 24h urinary sodium excretion. We will also measure blood pressure (BP), height, weight, hip and waist circumference using a standard protocol.

The second phase is to carry out a cluster randomised controlled trial in 240 children aged 10-11 years. After baseline assessments including 24h urine, BP and anthropometry, schools will be randomly allocated to either the control or intervention group. Additionally, both parents and grandparents of the participating children will be invited to take part in the study.

Intervention group: Our target is to lower salt intake by 20% for both children and their families. The intervention will be delivered to school children who will be empowered to persuade their parents and grandparents to reduce the amount of salt used during food preparation. The intervention consists of two components, i.e. classroom and family.

Control group: All children, their parents and grandparents in the control group will have the same measurements as those in the intervention group, but no salt awareness education will be given.

Duration and follow-up: The duration will be one school term, i.e. 5 months. All measurements made at baseline will be repeated at mid-term and again at the end of the trial. The biochemist who performs the measurements of urinary electrolytes will not be told which group the participant is allocated. The use of automatic BP device will minimise observer bias with BP measurement.

Outcomes: The primary outcome is the difference between the intervention and control group in the change in 24-h urinary sodium from baseline to the end of follow-up. The secondary outcome is the difference between the two groups in the change in BP.

Planned Impact

Humans only need a very small amount of salt from the diet, i.e. less than 1 g per day to maintain normal physiological function. However, the vast majority of the population including children eat far more salt than they need (on average most adult populations in the world eat 9-12 times that level). This high salt intake increases blood pressure and thereby increases the risk of cardiovascular disease such as stroke, heart attack and heart failure.

Our study will develop a new approach to reduce salt intake both in children and in adults. The immediate benefit from a reduction in salt intake is to lower blood pressure. For adults, this will have an immediate and significant benefit on reducing the risk of suffering a stroke, heart attack or heart failure. For children, a lower salt intake will prevent the development of hypertension and thereby cardiovascular disease later in life.

Because almost everyone eats far more salt than they require, almost everyone stands to benefit from a reduction in salt intake. From a population viewpoint, even a modest reduction in salt intake across the whole population will have a large impact on reducing the appalling burden of cardiovascular disease in the population.

Furthermore, it has also been demonstrated that a reduction in salt intake not only saves lives, but also saves money to individuals and the health service. To put the magnitude of the potential benefits in context, a paper in the Lancet demonstrates that a modest reduction in salt intake is more, or at the very least just, as cost-effective as tobacco control in terms of reducing cardiovascular disease - the leading cause of death and disability worldwide.

Publications

10 25 50

 
Description GIC & Changzhi Medical College 
Organisation Changzhi Medical College
Country China 
Sector Academic/University 
PI Contribution The George Institute's research team serve as the liaison between the project and Changzhi Medical College, the headquarters for the field team.
Collaborator Contribution Changzhi Medical College serves as the headquarters for the field team. The director of the Medical College is a key member of the study team. Changzhi Medical College is responsible for the implementation of the study protocol.
Impact We have collaborated on a paper PMID: 23864214
Start Year 2011
 
Description GIC & Changzhi Medical College 
Organisation George Institute for Global Health
Country Australia 
Sector Academic/University 
PI Contribution The George Institute's research team serve as the liaison between the project and Changzhi Medical College, the headquarters for the field team.
Collaborator Contribution Changzhi Medical College serves as the headquarters for the field team. The director of the Medical College is a key member of the study team. Changzhi Medical College is responsible for the implementation of the study protocol.
Impact We have collaborated on a paper PMID: 23864214
Start Year 2011
 
Description GIC & PKU 
Organisation George Institute for Global Health
Country Australia 
Sector Academic/University 
PI Contribution The George Institute researchers serve as the primary liaison between Peking University Health Science Center and the project.
Collaborator Contribution Peking University Health Science Center provided the expertise in child and adolescent health to develop the salt reduction curriculum. They will also serve as the liaison between the study team and public health officials, as well as policy makers, to translate the research outputs into policy.
Impact The education materials, posters, curricula and message deliver strategies were developed by this partnership. This collaboration has resulted in a paper PMID: 23864214.
Start Year 2011
 
Description GIC & PKU 
Organisation Peking University
Department Institute of Child and Adolescent Health
Country China 
Sector Academic/University 
PI Contribution The George Institute researchers serve as the primary liaison between Peking University Health Science Center and the project.
Collaborator Contribution Peking University Health Science Center provided the expertise in child and adolescent health to develop the salt reduction curriculum. They will also serve as the liaison between the study team and public health officials, as well as policy makers, to translate the research outputs into policy.
Impact The education materials, posters, curricula and message deliver strategies were developed by this partnership. This collaboration has resulted in a paper PMID: 23864214.
Start Year 2011
 
Description GIC & UM 
Organisation George Institute for Global Health
Country Australia 
Sector Academic/University 
PI Contribution This research has provided an opportunity for global health research training and experience for a Fogarty Global Health Fellow.
Collaborator Contribution This partnership has provided support for a research team member in the international coordinator, qualitative evaluation and informatics role.
Impact The partnership has resulted in the development of the evaluation on field studies and software components of the intervention .
Start Year 2012
 
Description GIC & UM 
Organisation University of Michigan
Department Global REACH
Country United States 
Sector Academic/University 
PI Contribution This research has provided an opportunity for global health research training and experience for a Fogarty Global Health Fellow.
Collaborator Contribution This partnership has provided support for a research team member in the international coordinator, qualitative evaluation and informatics role.
Impact The partnership has resulted in the development of the evaluation on field studies and software components of the intervention .
Start Year 2012
 
Description QMUL & GIC 
Organisation George Institute for Global Health
Country Australia 
Sector Academic/University 
PI Contribution Queen Mary University of London (QMUL) and the George Institute China (GIC) collaborated on the initial proposal for this project. Dr Feng He (PI) and Professor Graham MacGregor (Co-PI) represent QMUL and Professor Yangfeng Wu (Co-PI) represents GIC. Researchers from QMUL contribute extensive experience in salt reduction research.
Collaborator Contribution The George Institute China serves as the primary liaison to the field team and field site.
Impact This collaboration has resulted in a paper PMID: 23864214.
Start Year 2011
 
Description QMUL & GIC 
Organisation Queen Mary University of London
Department Wolfson Institute of Preventive Medicine
Country United Kingdom 
Sector Academic/University 
PI Contribution Queen Mary University of London (QMUL) and the George Institute China (GIC) collaborated on the initial proposal for this project. Dr Feng He (PI) and Professor Graham MacGregor (Co-PI) represent QMUL and Professor Yangfeng Wu (Co-PI) represents GIC. Researchers from QMUL contribute extensive experience in salt reduction research.
Collaborator Contribution The George Institute China serves as the primary liaison to the field team and field site.
Impact This collaboration has resulted in a paper PMID: 23864214.
Start Year 2011
 
Description Engagement with policy makers 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact A book that provides detailed description of the school-based education programme to reduce salt was sent to 20 members of the National Committee of the Chinese People's Political Consultative Conference who have interests in salt and health. Policies to promote salt reduction and salt substitute are expected to be proposed through the committee.
Year(s) Of Engagement Activity 2016
 
Description Luzhou International Cardiology Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr. Feng He was an invited Keynote speaker at Luzhou International Cardiology Conference July 2017. Approximately 700 people attended the conference. The attendees were a mix of academics, health professionals, government officials, representatives from non-government organisations, and students. Dr. He gave a presentation on salt, blood pressure and cardiovascular disease. She also took the opportunity to present the School-EduSalt programme, calling for widespread implementation across China. The presentation received very positive feedback.
Year(s) Of Engagement Activity 2017
 
Description NIHR Global Health Research Unit Action on Salt China (ASC) Launch 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Following the success of the school-based education programme to reduce salt (School-EduSalt) in northern China, Dr Feng He and Professor Graham MacGregor have secured an NIHR grant to further the salt reduction programme in China. In collaboration with Professor Puhong Zhang at the George Institute China, they have set up an NIHR Global Health Research Unit Action on Salt China (ASC). ASC will carry out various research and public health programmes with an aim of reducing salt intake by 15% by 2021 in China.

ASC has established partnerships with several Chinese health authorities including Chinese Centre for Disease Control and Prevention (China CDC), Chinese Centre for Health Education (CCHE) and China National Centre for Food Safety Risk Assessment (CFSA).

ASC organised a Launch event in Beijing on 11th October 2017. The event was very successful in generating the momentum of salt reduction in China. The key message has reached a wide range of the population through press release and media coverage. Importantly, the event was attended by several senior officials from central and provincial government, e.g. Mr. Qunan Mao, Director-General of Department of Communication and Health Promotion at the National Health and Family Planning Commission (former Ministry of Health), Mr. Changning Li, Director-General of Chinese Center for Health Education, Professor Xinhua Li, Party Committee Secretary of China CDC, Professor Weixing Yan, Vice Director-General of China National Center for Food Safety Risk Assessment. There were also representatives from non-governmental organisations, WHO China office, British Embassy in Beijing, Academic Associations, the food industry, etc. All have expressed strong support for salt reduction and their willingness to collaborate and cooperate with ASC on this important course which will not only benefit the Chinese people, but also contribute to global health development.

ASC will continue to engage policy makers and other stakeholders to ensure research findings can be translated into public health policies, leading to a sustainable impact.
Year(s) Of Engagement Activity 2017
 
Description Press release for paper published in BMJ 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Upon publication of the BMJ paper, both WASH (World Action on Salt and Health) and The George Institute issued press releases which were picked up by many media outlets, generating wide media coverage in the UK, China and many other countries. Therefore, this research has had a wide reach, and has been disseminated to a large proportion of the general population.
Year(s) Of Engagement Activity 2015
URL http://www.actiononsalt.org.uk/news/Salt%20in%20the%20news/2015/150750.html
 
Description School-EduSalt was included in the impact Brochure for RCUK funded programmes in China 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The School-EduSalt programme, as a case study, was included in the impact Brochure for RCUK funded programmes in China - "Shaping the Future: UK-China Collaborative Research" and received lots of positive feedback.
Year(s) Of Engagement Activity 2015
URL http://www.rcuk.ac.uk/international/offices/china/chinanews/150727/
 
Description World Salt Awareness Week 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact The study was published coinciding with the World Salt Awareness Week 2015, the theme of which was "Salt and Children". The Week highlighted the importance of reducing salt intake in children. Over 30 countries took part in the salt awareness week. Many countries expressed interest in the School-EduSalt programme.
Year(s) Of Engagement Activity 2015
URL http://www.worldactiononsalt.com/awarenessweek/World%20Salt%20Awareness%20Week%202015/142120.html