Prevention of diabetes And Obesity in South Asians Trial: lessons for the future

 

Raj Bhopal for the Prevention of Diabetes and Obesity in South Asians (PODOSA) Trial team

INTRODUCTION: People with Indian subcontinent ancestry are prone to type 2 diabetes particularly when they live overseas or in urban South Asia. The Prevention of Diabetes and Obesity in South Asians Trial (PODOSA) started in 2006 and completed in 2013.

METHODS: we tailored existing trial interventions by creating materials in specific languages, delivering the intervention in the family home and involving family members to provide support. The trial aimed to recruit 600 adults with prediabetes but we recruited 171 into a controlled, family-cluster, randomised trial (86 controls & 85 intervention participants in 156 families). The intervention group received 15, and the control group four, contacts with dietitians over 3-years. This analysis used linear regression models providing mean differences (95% CI) in baseline-adjusted weight at three-years.

RESULTS: Recruitment was difficult but retention was excellent as most participants (97.7%) finished. The primary outcome of the trial was changed from progression to diabetes to weight change (continuous outcomes provide more study power). We successfully tailored prior trials and materials for our populations. The intervention group lost 1·13 kg, and the control group gained 0·51 kg, an adjusted mean difference of 1·64 (0·44, 2·83) kg.  In the intervention group compared to the control group:  33 participants lost ≥2·5 kg compared to 12 (adjusted OR 3·92 (1·68, 9·3)); and the mean 3-year cost of dietitians, the main additional cost, was £1190 compared to £575 (95% CI for difference, £561-668).

CONCLUSIONS: The effect was modest but given that multiethnic societies need to ensure health interventions are equitable across all their populations, more trials of this kind are required. We will reflect on how this experience will help in controlling the diabetes epidemic.