Diet, physical activity and cardiometabolic health in Malaysian adolescents: from epidemiology to intervention

Lead Research Organisation: University of Bristol
Department Name: Sch for Policy Studies


In Malaysia the prevalence of obesity among adolescents is increasing and non-communicable diseases, like type 2 diabetes and cardiovascular disease, account for two out of three deaths. While research in European and US-based populations has found that particular lifestyle factors might cause adolescents to be fatter and less fit we do not have a complete picture of what causes these problems in Malaysia. In this study we are going to look at how different lifestyle factors, like foods eaten, timing or frequency of eating, physical activity, sedentary behaviours and their timing or location, combine together to create an overall behavioural pattern score that indicates whether adolescents have good health.
We've previously found that a combination of factors is more important for health compared with single factors alone. Initial analysis of health outcomes will focus on obesity, blood pressure, and how much LDL cholesterol, fats and glucose are in blood samples. We also plan to use a new, reproducible laboratory technique, known as metabolomics, to measure 233 different components of blood that indicate a range of metabolic processes. This will help us find out in much more detail than ever before how behaviour leads to better cardiovascular health via metabolic pathways. When we know more about the pathway that leads from lifestyle to disease we will be better able to predict who will stay healthy and who will not. In this study, one of our aims is to find the main behaviours related to keeping a healthy metabolism and reducing the risk of cardiovascular disease in the future. We'll then work out how these behaviours can changed by an intervention.
This research is possible because of a large study of over 1361 adolescents, called MyHeARTs. The aim of MyHeARTs was to identify which factors best predict health to enable the early detection and prevention of type 2 diabetes and cardiovascular disease. MyHeARTs started in 2012, collecting information on the behaviour and health of 1361 adolescents from 15 urban and rural schools in 3 regions of Malaysia and has just completed a third follow-up in 2016. The participants have provided detailed reports of their diet, activity, and other health behaviours as well as measurements of body composition, physical fitness and blood samples at age 13, 15 and 17, which we will use for this study. We are interested to see whether combinations of lifestyle behaviours can accurately predict changes in the blood chemical profile of participants as they progress through adolescence before they develop clear symptoms of cardiovascular disease or diabetes.
Finally, within this project we lay the foundations for improving adolescents' metabolic health. We will talk to adolescents and school staff about how they could adopt the behaviours we found were important for health in MyHeART. We will then use their views paired with known methods of behaviour change to encourage a healthy lifestyle and prevent disease that will work in countries, like Malaysia, where resources are limited.

Technical Summary

We propose a mixed methods approach including secondary analysis of MyHeARTs cohort data, conducting systematic reviews, metabolic analysis of stored serum samples, qualitative research with key stakeholders and full evaluation of a pilot intervention. We will use detailed data on health behaviours and intermediate risk factors from 1361 adolescents aged 13-17 years to generate behavioural patterns predictive of cardiometabolic risk. Patterns will incorporate diet, eating architecture, physical activity, and sedentary behaviours and key intermediate risk factors like high fat intake, low cardiorespiratory fitness or obesity. A hybrid of data-driven and hypothesis-based multivariate pattern analysis, RRR will be applied to generate different behavioural patterns that explain variation in hypothesised intermediate variables on the causal pathway from behaviour to disease. Patterns will reveal specific behaviours with the highest weights, thus explaining the highest variation in the pathway to disease, which should be the most promising targets for intervention. We will conduct prospective analyses of change in behavioural patterns with change in blood lipids, glucose and blood pressure from age 13-17 years using linear and logistic regression. We will then explore associations with metabolic health further by incorporating selected novel metabolites from lab-analysis of stored serum samples collected at age 15 and 17. Combining findings of the systematic review with MyHeART analyses, we will conduct semi-structured qualitative focus groups and interviews with adolescents and school staff to explore how health behaviours might be changed. After mapping intervention to behaviour change techniques, a pilot intervention will be run in 6 secondary schools (3 intervention and 3 control) with a comprehensive outcome and process evaluation. Based on experience in UK studies, we will pilot tools to assess costs associated with developing and delivering the intervention.

Planned Impact

We will utilise and build on an established cohort, MyHeARTs, and engage with regional and national stakeholders through all phases of the proposed study, to maximise the potential for impact in Malaysia. Short-term, our findings will be useful to researchers. A specific aim of this project is to create the infrastructure for open access required for wide-spread sharing of MyHeARTs data. In addition to academic beneficiaries (outlined elsewhere) in the medium to long-term, the proposed study is expected to have a sustained impact on: 1) Adolescents; 2) Schools; 3) Policy makers; 4) Society and the Economy. The way in which each group could benefit are summarised below:
1. Adolescents: Our approach to intervention development engages with adolescents, therefore they are directly involved in creating solutions to health problems they face. We hope adolescents involved in the intervention will enjoy it and find their diet, physical activity and biomarkers of health improve. Over the long-term, if the pilot study indicates feasibility then it will be tested via a full randomised controlled trial (RCT), for which further funding will be sought. If intervention is shown to be effective it will be widely disseminated to benefit the behavioural patterns and health of a large number of Malaysian adolescents.
2. Schools: Intervention schools will benefit directly from a new, evidence-based behaviour change programme that is informed by their own students and staff. Depending on how the intervention is delivered, intervention schools may immediately benefit from the training of the teachers or other staff who will deliver the intervention, or from the availability to them of the developed intervention materials. More broadly, control schools and Malaysian Education Authorities, to whom we will disseminate the findings, will understand more about the feasibility of utilising existing staff to deliver a diet and physical activity programme at school level. These benefits will be evident at the end of the study (Dec 2018).
3. Policy makers: Our project will provide policy makers in Malaysia with information about the most important behaviours contributing to cardiometabolic health based on a large representative cohort of Malaysian adolescents. To maximise information exchange and knowledge transfer, a dissemination event will be held at the end of the project. Findings from all phases of the study will also be disseminated via scientific reports, infographics, press releases and policy briefings to policy makers and professional groups in Malaysia, including the Malaysian Association for the Study of Obesity, Malaysian Paediatric Association and the ASM Obesity Task Force. The Malaysian Ministry of Health supports the research proposed in this project and have an interest in providing funds to ensure the sustainability of our international research partnership beyond the end of this project (see letter of support). Information about the potential utility of the intervention will become available and will help policy makers in Malaysia develop public health policy over the next 5-10 years.
4. Society and the economy: Our trial aims to evaluate potentially effective and sustainable strategies for preventing obesity and promoting cardiovascular health in Malaysian adolescents. In the longer-term (i.e. 5-10 years), it is envisaged that the data obtained from this study lead directly to a phase II trial of a feasible intervention. The identification of dietary and physical activity behaviours linked to improved cardiometabolic health will help target public health strategies and improve cost-effectiveness. We will pilot the development of tools to assess all costs associated with developing and delivering the intervention during the pilot study, to provide country-specific estimates for local applicability. This information is likely to lead to improved intervention uptake and longer-term sustainable impact at local and national levels.


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