Association between Long-term Exposure to PM
2.5and Incidence of Type 2 Diabetes in Taiwan
Chia-Ying Li, National Cheng Kung University, Tainan, Taiwan Huey-Jen Su, National Cheng Kung University, Tainan, Taiwan Chih-Da Wu, National Chiayi University, Chiayi, Taiwan Wen-Chi Pan, National Yang-Ming University, Taipei, Taiwan Yi-Chen Chen, National Cheng Kung University, Tainan, Taiwan;
Background and Aim:
Long-term PM2.5 exposure may contribute to elevated incidence of type 2 diabetes, but the results were not always significant. Furthermore, empirical research evidence relating PM2.5 and diabetes is still lack in Asian countries. This study assessed the association between PM2.5 and type 2 diabetes in Taiwan.
Methods:
We conducted a retrospective cohort study from 1st January, 2001 through 31st December, 2011. Health information of participants was retrieved from the Longitudinal Health Insurance Database 2000 (LHID 2000) of the National Health Insurance Research Database (NHIRD). Incidence of diabetes was defined as participants who were seen for diabetes (ICD 9 code: 250) more than 3 times in a year.
A 6-year (2006-2011) exposure to PM2.5 was estimated using Oridinary Kriging to approximate participants’ long-term exposure to particle pollutants. With the adjustment for Individual-level variables, comorbidities, and environmental factors, the Cox proportional hazards models were used to investigate the associations between PM2.5 exposure and type 2 diabetes incidence.
Results:
The study excluded subjects with diagnosed diabetes before 2001 and subjects who were less than 20 years old. Of the 492,878 eligible participants enrolled in the study, a total of 44,029 newly developed diabetes cases were identified in the study period, and the 6-year average incidence rate was 1.16%. The averaged 6-year exposure to PM2.5 (2006-2011) was 33.2 μm/m3 (range, 13.6 to 47.8 μm/m3). For every 10 μg/m3 increase of PM2.5, the adjusted hazard ratio (HR) for incidence diabetes was 1.03 (95% confidence interval [CI] = 1.02 to 1.04).
Conclusions:
Long-term exposure to PM2.5 increased the risk of type 2 diabetes in the population of
Taiwan. These findings add to the growing evidence that PM2.5 is a potential risk factor for type 2 diabetes.
