Ambient air pollution and incidence of early-onset paediatric type 1 diabetes: A retrospective population-based cohort study

摘要

Background: Studies have reported increasing incidence rates of paediatric diabetes, especially among those aged 0-5 years. Epidemiological evidence linking ambient air pollution to paediatric diabetes remains mixed. Objective: This study investigated the association between maternal and early-life exposures to common air pollutants (NO_2, PM_(2.5), O_3, and oxidant capacity [Ox; the redox-weighted average of O_3 and NO_2]) and the incidence of paediatric diabetes in children up to 6 years of age. Methods: All registered singleton births in Ontario, Ca nada occurring between April 1st' 2006 and March 31st 2012 were included through linkage from health administrative data. Monthly exposures to NO_2, PM_(2.5), O_3, and O_x were estimated across trimesters, the entire pregnancy period and during childhood. Random effects Cox proportional hazards models were used to assess the relationships with paediatric diabetes incidence while controlling for important covariates. We also modelled the shape of concentration-response (CR) relationships. Results: There were 1094 children out of a cohort of 754,698 diagnosed with diabetes before the age of six. O_3 exposures during the first trimester of pregnancy were associated with paediatric diabetes incidence (hazard ratio CHR) per interquartile (IQR) increase = 2.00, 95% CI: 1.04-3.86). The CR relationship between O_3 during the first trimester and paediatric diabetes incidence appeared to have a risk threshold, in which there was little-to-no risk below 25 ppb of O_3, while above this level risk increased sigmoidally. No other associations were observed. Conclusion: O_3 exposures during a critical period of development were associated with an increased risk of paediatric diabetes incidence.