Primary research aim
Determine whether a family-based lifestyle modification delivered by community health workers vs usual care is clinically- and cost-effective for prevention and risk reduction of T2D.
Secondary research aims
Assess effects on adiposity measures, glucose metabolism and other measures of well-being in the index case and family members.
Research objectives and methodology
Our goal is to develop approaches to health promotion through lifestyle modification (healthy diet, increased physical activity) that are acceptable, effective and efficient for prevention of T2D in South Asian communities from diverse settings, for scale-up across the Indian subcontinent and Europe.
iHealth-T2D will study men and women from the Indian subcontinent (India, Pakistan and Sri Lanka), as well as Europe (UK) to provide evidence about the implementation of lifestyle modifications in both high and low income settings. We will enrol men and women equally, in rural and urban settings, and across a range of socio-economic classes, to reduce inequalities. We will use focus groups, and the experience and knowledge of local leaders and local experts to develop approaches that are culturally appropriate, acceptable, sustainable and scalable amongst all segments of the community.
We will determine the factors that influence participation in and benefit from health promotion. We will thereby identify the obstacles that underlie inequities and gender gaps, and the barriers and facilitators that inhibit or strengthen local and national implementation. Our approach is thus carefully designed to be equitable and reduce gender, social and socio-economic inequalities in health promotion, locally, nationally and globally. We will complete a detailed health economic analysis of our approaches to implementation of lifestyle modification. This will include assessment of incremental value, and potential ethical, legal, regulatory, social and economic implications of scaling up at the local, regional and national levels.
The findings will provide objective evidence to enable local and national experts and policy makers to scale up intervention in a sustainable way, and to translate and embed the findings from our research into clinical practice and policy, and thereby help reverse the epidemic of T2D amongst South Asians.
The secondary objectives of the study are to:
- Engage local investigators and local communities in adapting our established protocols for use amongst South Asians on the Indian subcontinent;
- Analyse the data to determine whether family-based lifestyle modification vs usual care reduces risk of T2D (primary endpoint) amongst South Asians with i. central obesity; ii. prediabetes and iii. overall (with central obesity and / or obesity). Compare effectiveness of the intervention between groups.
- Investigate secondary endpoints, including health gains in family members. Identify social, demographic and environmental factors influencing primary and secondary endpoints.
- Carry out a health economic analysis of family-based lifestyle modifications vs usual care for prevention of T2D on the Indian subcontinent and Europe. Quantify the cost-effectiveness of screening by waist circumference vs HbA1c. Assess incremental value, and potential ethical, legal, regulatory, social and economic implications of scaling up locally and nationally.
- Disseminate and exploit the findings. Engage local and national experts and policy makers in translating and embedding the findings into practice and policy.
South Asians typically live together as extended families, in a single household. Many behaviours relevant to healthy lifestyle take place within the family home, including meal preparation, communal eating and use of recreational time. These identify family environment as an important determinant of metabolic health, a hypothesis supported by the clustering of obesity and T2D in South Asian families. Recent studies suggest that lifestyle intervention which targets the family environment is effective at achieving weight loss amongst South Asians with IGT in Europe, but this has not yet been extended to prevention of T2D.
We have developed and evaluated a family-based intervention for health promotion amongst UK South Asians with central obesity. The intervention is closely based on established, successful protocols for prevention of T2D through weight loss in Europeans, but has been culturally adapted for South Asians (e.g. detailed food composition tables that capture customary diet, and translation of materials into relevant languages). Family members of the index obese South Asian are strongly encouraged to join the program, in particular children and the family cook(s). The ambition is for the family to take joint responsibility for change to a healthy lifestyle, supporting and guiding the obese index case in making healthy choices, and maintaining long-term engagement in the lifestyle intervention program. The target is for the index case to avoid new onset of T2D as defined by the primary endpoint, through a combination of reduced calorific intake, lower consumption of fat and refined sugars, and increased physical activity (150 minutes of moderate physical activity per week). Family members are also encouraged to make healthier choices.
Lifestyle modification is delivered over 22 contact sessions (weekly for 3 months, then every 4 weeks for 9 months). Sessions are delivered in the family home and community settings, by affordable community health workers from a range of healthcare backgrounds. The initial session focuses on education around obesity and diabetes for the whole family. Subsequent sessions focus on implementation of healthy diet and increased physical activity, and are attended by the index case and family members. Nutritional education is focused on the shopper and cook of the family, with attention to cooking methods, portion size, food choices, amount of fat used in cooking and encouraging foods high in dietary fibre.
On the other hand, the control group will be invited to attend one single health promotion session at the beginning of the study and provided written material about the study.
- John Chambers, Imperial College, London (United Kingdom)
- Gary Frost, Imperial College, London, United Kingdom
- Ninha Silva, Imperial College, London, United Kingdom
- Jaspal Kooner, Imperial College, London, United Kingdom
- Sujeet Jha, Devki Devi Foundation, Delhi, India
- Prasad Katulanda University of Colombo, Comlombo, Sri Lanka
- Rajitha Wickremasinghe, University of Kelaniya, Colomobo, Sri Lanka
- Graham Cookson, University of Surrey, Guildford, United Kingdom)
- Ravindra Rannan-Eliya, Institute of Health Policy, Colombo, Sri Lanka
- Karien Stronks, University of Amsterdam, Amsterdam, Netherlands
- Marjo-Riitta Jarvelin, University of Oulu, Oulu, Finland
- Sajjad Ahmad, Punjab Institute of Cardiology, Lahore, Pakistan
- Khadija Irfan Khawaja, Services Institute of Medical Sciences, Lahore, Pakistan
- Wahl, S., Drong, A., Lehne, B., Loh, M., Scott, W. R., Kunze, S., . . . Chambers, J. C. (2017). Epigenome-wide association study of body mass index, and the adverse outcomes of adiposity. Nature, 541(7635), 81-86. doi:10.1038/nature20784
- Chambers JC, Loh M, Lehne B, Drong A, Kriebel J, Motta V et al. Epigenome-wide association of DNA methylation markers in peripheral blood from Indian Asians and Europeans with incident type 2 diabetes: a nested case-control study. Lancet Diabetes Endocrinol. 2015;3(7):526-34.
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- Fuchsberger, C., Flannick, J., Teslovich, T. M., Mahajan, A., Agarwala, V., Gaulton, K. J., . . . McCarthy, M. I. (2016). The genetic architecture of type 2 diabetes. Nature, 536(7614), 41-47. doi:10.1038/nature18642Chambers JC, Abbott J, Zhang W, Turro E, Scott WR, Tan ST et al. The South Asian genome. PLoS One. 2014;9(8):e102645. doi:10.1371/journal.pone.0102645.
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- Chambers JC, Elliott P, Zabaneh D, et al. Common genetic variation near MC4R is associated with waist circumference and insulin resistance. Nat Genet 2009; 40: 716-718