Mediating effect of BMI on the association of economic status and coexistence of hypertension and diabetes in Bangladesh: A counterfactual framework-based weighting approach.

ABSTRACT

Background and Aims: Non-communicable diseases such as hypertension and diabetes are matters of huge concern worldwide, with an increasing trend in prevalence over the previous decade. First of all, this study aimed to evaluate the association between economic status (ES) and body mass index (BMI), ES and comorbidity of hypertension and diabetes, and BMI and comorbidity independently. Second, it explored the mediating role of BMI in the association between ES and comorbidity of hypertension and diabetes. Finally, it investigated whether the mediating effect differs with the place of residence, gender, and education levels. Methods: A total of 11,291 complete cases from the Bangladesh demographic and health survey 2017-18 were utilized for this study. Survey-based binary logistic regression or multiple logistic regression was used to find the association among outcome, exposure, and mediator variables, and a counterfactual framework-based weighting approach was utilized for mediation analysis. Results: Middle-income (adjusted odds ratio [AOR] 1.696, 95% confidence interval [CI] 1.219, 2.360) and rich (AOR 2.770, CI 2.054, 3.736) respondents were more likely to have comorbidity of hypertension and diabetes compared to the poor. The odds of comorbidity increased with the increase in BMI. A positive association was observed between ES and BMI. A significant mediating role of BMI in the association between ES and comorbidity was found. We observed that 19.85% (95% CI 11.50%, 49.6%) and 20.35% (95% CI 14.9%, 29.3%) of total effect was mediated by BMI for middle and rich respondents, respectively, compared to the poor. Conclusions: The mediating role of BMI was greater for female, no or primary educated respondents, and respondents from rural areas. Therefore, the study will facilitate policymakers of Bangladesh and other countries with a similar set-up to decide on health policies regarding hypertension and diabetes.