Exposure to particulate matter (PM2.5) and prevalence of diabetes mellitus in Indonesia

Background
Recently emerging evidence suggests an association between particulate matter less than 2.5 µm in diameter (PM2.5) exposure and diabetes risk. However, evidence from Asia is limited. Here, we evaluated the association between PM2.5 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 PM2.5 using QGIS software. Multilevel logistic regression with a random intercept based on village and cubic spline analysis were used to assess the association between PM2.5 exposure and the prevalence of diabetes mellitus. We also assessed the lower exposure at which PM2.5 has potential adverse effects.
Results
We included 647,947 subjects with a mean age of 41.9 years in our study. Exposure to PM2.5 levels was associated with a 10-unit increase in PM2.5 (fully adjusted odds ratio: 1.09; 95% confidence interval: 1.05–1.14). The findings were consistent for quartile increases in PM2.5 levels and the cubic spline function. Even when we restricted to those exposed to PM2.5 concentrations of less than 10.0 µg/m3 in accordance with the recommended guidelines for annual exposure to PM2.5 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 PM2.5 and the risk of diabetes.
Conclusions
Our findings suggest a positive association between PM2.5 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.