Effectiveness of a targeted lifestyle intervention in primary care on diet and physical activity among South Asians at risk for diabetes: 2-year results of a randomised controlled trial in the Netherlands

OBJECTIVES: In South Asian populations, little is known about the effects of intensive interventions to reduce the risk of type 2 diabetes on health behaviour. We examined the effectiveness at 2 years of a culturally targeted lifestyle intervention on diet, physical activity and determinants of behaviour change among South Asians at risk for diabetes. DESIGN: Randomised controlled trial with de facto masking. SETTING: Primary care. PARTICIPANTS: A total of 536 18- to 60-year-old South Asians at risk for diabetes (ie, with impaired glucose tolerance, impaired fasting glucose or relatively high insulin resistance) were randomised to the intervention (n=283) or a control (n=253) group. Data of 314 participants (n=165 intervention, n=149 control) were analysed. INTERVENTIONS: The culturally targeted intervention consisted of individual counselling using motivational interviewing (six to eight sessions in the first 6 months plus three to four booster sessions), a family session, cooking classes and a supervised physical activity programme. The control group received generic lifestyle advice. OUTCOME MEASURES: We compared changes in physical activity, diet and social-cognitive underlying determinants between the two groups at 2-year follow-up with independent-sample t-tests, chi-square tests and Fisher’s exact tests. RESULTS: At the 2-year follow-up, participants in the intervention group were more moderately to vigorously active than at baseline, but compared with changes in the control group, the difference was not significant (change min/week 142.9 vs 0.5, p=0.672). Also, no significant difference was found between the two groups in changes on any of the components of the diet or the social-cognitive determinants of diet and physical activity. CONCLUSIONS: The culturally targeted lifestyle intervention led to high drop-out and was not effective in promoting healthy behaviour among South Asians at risk for diabetes. Given the high a priori risk, we recommend to develop new strategies, preferably more acceptable, to promote healthy behaviour. TRIAL REGISTRATION: NTR1499; Results. www.trialregister.nl/trialreg/admin/rctview.asp?TC=1499