Exposure to particulate matter (PM_2.5) and prevalence of diabetes mellitus in Indonesia

Background: Recently emerging evidence suggests an association between particulate matter less than 2.5 µm in diameter (PM_2.5) exposure and diabetes risk. However, evidence from Asia is limited. Here, we evaluated the association between PM_2.5 exposure and the prevalence of diabetes mellitus in one of the most populated countries in Asia, Indonesia. Methods: We used the 2013 Indonesia Basic Health Research, which surveyed households in 487 regencies/municipalities in all 33 provinces in Indonesia (n = 647,947). We assigned individual exposure to PM_2.5 using QGIS software. Multilevel logistic regression with a random intercept based on village and cubic spline analysis were used to assess the association between PM_2.5 exposure and the prevalence of diabetes mellitus. We also assessed the lower exposure at which PM_2.5 has potential adverse effects. Results: We included 647,947 subjects with a mean age of 41.9 years in our study. Exposure to PM_2.5 levels was associated with a 10-unit increase in PM_2.5 (fully adjusted odds ratio: 1.09; 95% confidence interval: 1.05–1.14). The findings were consistent for quartile increases in PM_2.5 levels and the cubic spline function. Even when we restricted to those exposed to PM_2.5 concentrations of less than 10.0 µg/m³ in accordance with the recommended guidelines for annual exposure to PM_2.5 made by the World Health Organization, the association remained elevated, especially among subjects living in the urban areas. Hence, we were unable to establish a safe threshold for PM_2.5 and the risk of diabetes. Conclusions: Our findings suggest a positive association between PM_2.5 exposure and prevalence of diabetes mellitus, which is possibly below the current recommended guidelines. Further studies are needed to ascertain the causal association of this finding.