Air Pollution and Diabetes Mellitus

Abstract

Background: Air pollution is a leading contributor to the burden of disease globally. Recent systematic reviews suggested that air pollution may cause diabetes mellitus among adults. However, the number of studies included in these reviews were small and the confidence intervals were wide. Leading health practitioners have called on studies to quantify the burden of disease due to air pollution and examine health disparities associated with such burden. In response, our study aims to update previous reviews with recent studies and to quantify the burden of diabetes due to air pollution in the United States (US) while examining health disparities. Method: We conducted a systematic review and meta-analysis of studies examining exposure to air pollution in the form of Nitrogen dioxide (NO2), Black Carbon (BC), and Ultra Fine Particles (UFP) and the risk of developing diabetes mellitus among adults. Using joined the concentration-response function of the pooled estimate with air pollution, census, and diabetes prevalence and incidence across the US to produce burden estimates. We explored health disparities across geographical and social stratum. Finally, we developed accessible interactive maps and tables to visualize and explore the burden of disease across counties. Results: Our search yielded 21 studies included in our analysis. We found that exposure to NO2 increased the risk of developing diabetes among adults OR = 1.05 [1.04-1.05, I2 = 95%] per 10 μg/m3 unit increase. For BC and UFP, we could not reach a similar conclusion since the number of included studies was small. We estimated that around 5,978,048 prevalent and 213, 641 incident diabetes cases may be attributable to air pollution exposure representing 28.1% and 11.0% of all diabetes prevalent and incident cases, respectively. The fraction of attributable cases were higher in urban areas compared to rural areas, and in census blocks with a predominantly Asian population and lower-income groups. Conclusion: This study updates the current knowledge of exposure to air pollution and the risk of developing diabetes mellitus, quantifies the burden of disease to air pollution exposure, explores the health disparity associated with the burden of disease, and presents interactive tools that make our results accessible.