Faith-Based Lifestyle Intervention for Diabetes Prevention Among Adults in Bangladesh: A Cluster Randomized Clinical Trial.

Importance: The incidence of type 2 diabetes (T2D) is increasing in low- and middle-income countries. Effective, culturally tailored interventions are needed for diabetes prevention. Objective: To evaluate the effectiveness of a 12-month, mosque-based, faith-integrated lifestyle intervention in reducing T2D incidence among adults with prediabetes in rural Bangladesh. Design, Setting, and Participants: This parallel-group, cluster randomized clinical trial (RCT) was conducted from April 2022 to April 2023 across 8 rural mosque clusters in 5 districts of Bangladesh, with a 12-month follow-up. Adults (aged 25-65 years) were screened using a validated diabetes risk score. Individuals with high risk scores underwent oral glucose tolerance testing, and those with prediabetes (fasting blood glucose of 6.1-6.9 mmol/L, 2-hour blood glucose of 7.8-11.0 mmol/L [to convert to milligrams per deciliter, multiply by 18], or both, according to World Health Organization criteria) were included in this trial. Participants were randomized (1:1) by mosque cluster to the intervention or the control. After baseline assessments, participants who completed the 12-month follow-up were included in the intention-to-treat analysis. Intervention: The intervention group attended monthly mosque-based sessions integrating Islamic teachings with structured guidance on diet, physical activity, and behavior modification delivered by imams and trained female assistants. The control group received usual care (standard health advice including a health leaflet and referral to local health services) at enrollment. Main Outcomes and Measures: The primary outcome was the 12-month cumulative incidence of T2D. Secondary outcomes included changes in weight, body mass index (BMI), glycemic markers, lipid profiles, blood pressure, diabetes-related knowledge, physical activity, and quality of life. Results: Of the 799 participants (mean [SD] age, 46.2 [11.6] years; 424 women [53.1%]) randomized, 641 completed the 12-month follow-up and were included in the intention-to-treat analysis: 341 (n = 4 mosques) in the intervention group and 300 (n = 4 mosques) in the control group. The intervention group had a significantly lower 12-month cumulative T2D incidence (9.8% [95% CI, 7.1%-13.5%]) vs the control group (17.1% [95% CI, 13.4%-21.6%]), with an absolute risk reduction of 7.3 percentage points (95% CI, 5.2-10.6 percentage points), a relative risk reduction of 42.5% (95% CI, 15.0%-70.0%), and a number needed to treat of 14 (95% CI, 9-39). In Cox proportional hazards regression adjusted for clustering, the hazard ratio was 0.75 (95% CI, 0.60-0.95; P = .02), corresponding to a 25.0% reduction in diabetes risk. Secondary outcomes including weight, BMI, fasting glucose, 2-hour blood glucose, hemoglobin A1c, lipid profiles, diabetes-related knowledge, physical activity, and quality of life also improved significantly more in the intervention group compared with the control group. Conclusions and Relevance: In this cluster RCT involving adults with prediabetes, a culturally adapted, mosque-based lifestyle intervention significantly reduced T2D incidence over 12 months in rural Bangladesh. These results demonstrate the potential for scalable and cost-effective diabetes prevention programs in low-resource, Muslim-majority communities. Trial Registration: ISRCTN Registry Identifier: ISRCTN91564707.