Background: Air pollution has been related to type 2 diabetes (T2D). However, little is known about the relation between long-term exposure to multiple ambient air pollutants and the risk of T2D. We aimed to prospectively assess the joint association of various air pollutants with the risk of T2D and examine the modification effect by obesity status on the relationship.
Methods: A total of 449,006 participants from UK Biobank who were free of T2D at baseline (2006-2010) were included in the current study and followed up to March 2020. Ambient air pollutants, including particulate matter (PM) with diameters ≤2.5 µm (PM2.5), between 2.5 µm and 10 µm (PM2.5-10), nitrogen oxides (NO2), and nitric oxide (NO) were estimated by a Land Use Regression model. An air pollution score was created to assess the joint exposure to the four air pollutants.
Results: During a median of 11 years follow-up, we documented 18,239 incident T2D cases. The hazard ratios (95% confidence interval) for T2D associated with the extreme quintiles of PM2.5, PM2.5-10, NO2, and NO were 1.12 (1.05 to 1.18), 1.06 (1.00 to 1.11), 1.11 (1.04 to 1.18), and 1.12 (1.06 to 1.18), respectively. We also found that the air pollution score was significantly associated with an increased risk of T2D. Compared to the lowest quintile of air pollution score, the multivariate-adjusted hazard ratio for T2D was 1.05 (0.99 to 1.10), 1.06 (1.00 to 1.11), 1.09 (1.03 to 1.15), and 1.12 (1.06 to 1.19) for the second to fifth quintile, respectively. In addition, we found a significant interaction between the air pollution score and obesity status on the risk of T2D (p-interaction <0.001). The observed association was more pronounced among overweight and obese participants than in the normal-weight people.
Conclusion: Our results indicate that an air pollution score, which incorporated PM2.5, PM2.5-10, NO2, and NO, is associated with an increased risk of T2D, and such association is strengthened by higher adiposity.
X. Li: None. M. Wang: None. H. Ma: None. T. Zhou: None. Y. Heianza: None. L. Qi: None.