Effect of a lifestyle intervention on weight change in south Asian individuals in the UK at high risk of type 2 diabetes: a family-cluster randomised controlled trial

Raj S Bhopal,Anne Douglas,Sunita Wallia,John F Forbes,Michael E J Lean,Jason M R Gill,John A Mcknight,Naveed Sattar,Aziz Sheikh,Sarah H Wild,Jaakko Tuomilehto,Anu Sharma,Ruby Bhopal,Joel B E Smith,Isabella Butcher,Gordon D Murray

doi:10.1016/s2213-8587(13)70204-3

Abstract

The susceptibility to type 2 diabetes of people of south Asian descent is established, but there is little trial-based evidence for interventions to tackle this problem. We assessed a weight control and physical activity intervention in south Asian individuals in the UK. We did this non-blinded trial in two National Health Service (NHS) regions in Scotland (UK). Between July 1, 2007, and Oct 31, 2009, we recruited men and women of Indian and Pakistani origin, aged 35 years or older, with waist circumference 90 cm or greater in men or 80 cm or greater in women, and with impaired glucose tolerance or impaired fasting glucose determined by oral glucose tolerance test. Families were randomised (using a random number generator program, with permuted blocks of random size, stratified by location [Edinburgh or Glasgow], ethnic group [Indian or Pakistani], and number of participants in the family [one vs more than one]) to intervention or control. Participants in the same family were not randomised separately. The intervention group received 15 visits from a dietitian over 3 years and the control group received four visits in the same period. The primary outcome was weight change at 3 years. Analysis was by modified intention to treat, excluding participants who died or were lost to follow-up. We used linear regression models to provide mean differences in baseline-adjusted weight at 3 years. This trial is registered, number ISRCTN25729565. Of 1319 people who were screened with an oral glucose tolerance test, 196 (15%) had impaired glucose tolerance or impaired fasting glucose and 171 entered the trial. Participants were in 156 family clusters that were randomised (78 families with 85 participants were allocated to intervention; 78 families with 86 participants were allocated to control). 167 (98%) participants in 152 families completed the trial. Mean weight loss in the intervention group was 1.13 kg (SD 4.12), compared with a mean weight gain of 0.51 kg (3.65) in the control group, an adjusted mean difference of -1.64 kg (95% CI -2.83 to -0.44). Modest, medium-term changes in weight are achievable as a component of lifestyle-change strategies, which might control or prevent adiposity-related diseases. National Prevention Research Initiative, NHS Research and Development; NHS National Services Scotland; NHS Health Scotland.

Highlights

Progression to diabetes was observed less frequently in the intervention group than the control group but the difference was not statistically significant
In this study of 171 individuals of south Asian descent living in the UK, a culturally adapted, family-based lifestyle intervention consisting of about 15 visits from a dietitian over 3 years resulted in significantly greater weight loss than did annual contact and simple lifestyle www.thelancet.com/diabetes-endocrinology Vol 2 March 2014
Our trial shows that provision of simple information about diet and lifestyle did not stop this tendency whereas a tailored, moderate-intensity intervention targeted at those at high risk of developing diabetes counteracted it

Summary

Introduction

The susceptibility to type 2 diabetes of people of south Asian descent was established in the UK in 1985.1 There is little trial-based evidence for interventions to tackle this problem[2,3,4] existing consensus guidelines emphasise weight management through dietary change and physical activity.[3,5,6] This approach has been shown to be effective in 3-year intervention trials of diabetes prevention programmes in other ethnic groups in several countries including China,[7] Finland,[8] the USA,[9] and India,[2] and is, arguably, cost effective.[10] Systematic reviews show that achieving sustained weight management (with or without increased physical activity) is difficult.[11,12] Intensive lifestyle interventions, can reduce progression from prediabetes (impaired glucose tolerance or impaired fasting glucose, or both) to diabetes by up to 60% over 3 years.[10,13,14].

Methods

Results

Conclusion