The Relationship of Incident Diabetes with Chronic Particulate Matter Exposures

ISEE-0471 Background and Objective: Information is lacking as to whether Diabetes Mellitus (DM) merely modifies the impact of air pollution exposures on cardiovascular outcomes or whether it is also an air pollution associated outcome. Using two prospective cohorts, the Nurses' Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS), we investigated the relationship of incident DM with chronic exposures to PM10 (particulate matter less than 10 microns in diameter), PM2.5 (particulate matter less than 2.5 microns in diameter), and PM10-2.5 (particulate matter between 2.5 and 10 microns in diameter). Methods: Cases were initially reported through biennial questionnaires and confirmed by supplemental questionnaire. During the follow-up from 1992 to 2002, questionnaires also provided information on time-varying covariates and updated addresses which were geocoded and used to assign air pollution exposures that were estimated with GIS-based spatial statistical models. Results: Among participants living in metropolitan areas of the northeastern and midwestern US, there were 4,073 incident cases of DM in the NHS, and 646 cases in the HPFS. Among women, DM was significantly associated with increases in each size fraction of PM averaged over the 12 months prior to diagnosis in single pollutant time and age adjusted models. Risk of DM was also elevated for men. The greatest risk was related to PM2.5 exposure (HR for women: 1.32; 95%CI: 1.14-1.51; HR for men: 1.36; 95%CI: 0.98, 1.87). After adjustment for known risk factors for DM, risks remained elevated but were considerably attenuated. Conclusion: Using time-varying measures of covariates and long-term exposures, we found particulates were associated with increased risks of DM among women and men living in the northeastern and midwestern US. This relationship was confounded by known risk factors for DM.