1 / 20

Diabetes incidence and long-term exposure to air pollution: a cohort study

Diabetes incidence and long-term exposure to air pollution: a cohort study. Zorana Jovanovic Andersen 14.09.2011 ISEE. Diabetes. Diabetes epidemic , cased in large part by obesity epidemic and physical inactivity

lenci
Download Presentation

Diabetes incidence and long-term exposure to air pollution: a cohort study

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Diabetes incidence and long-termexposure to air pollution: a cohortstudy Zorana Jovanovic Andersen 14.09.2011 ISEE

  2. Diabetes • Diabetes epidemic, cased in large part by obesityepidemic and physicalinactivity • Metabolicdisease, highbloodsugar, type-2, insulin resistance • In USA

  3. Background: Diabetes & Air Pollution • Diabetes established modifier of a link between air pollution andCVD (inflammation, endothelial dysfunction, prothrombotic changes, altered heart rate variability) • Biological mechanismprolonged exposure to air pollution involves inflammation in adipose tissue, increased blood glucose levels, insulin resistance, glucose intolerance in mice • Short-term exposure to elevated air pollution linked to increased risk of diabetes mortality and hospitalization

  4. Evidence: Diabetes Prevalence & Air Pollution

  5. Evidence: Diabetes Incidence & Air Pollution

  6. Aim of thisstudy • We studied the association between traffic-related air pollution levels at the residence and the risk for diabetes in an elderly Danish cohort, and tested for an effect modification by lifestyle, education, and co-morbid conditions.

  7. Methods - Cohort • Danish Diet, Cancer and Health cohort • 57 053 subjects, Copenhagen and Aarhus • Interviewed in 1993-1997 (baseline) • Age 50-65 years • Linkage to Central Population Registry and Danish Address Database - residential address history (1971) • Linkage to Danish National Diabetes Register (1995) for assessment of health outcome

  8. Danish Diabetes Register • The NDR was established by linking existing nationwide administrative records in the Danish healthcare system

  9. Danish Diabetes Register • Results of blood glucose measurements are not included • 50-60% of the patients > 1 inclusion criterion • Not possible to distinguish type 1 and type 2 diabetes • Due to different dates of initiation of the underlying registers and accumulation of prevalent cases, only incidence values after 1 January 1995 were found to be reliable • Incidence of diabetes was defined as the earliest record in the diabetes register occurring after 1 January 1995, between baseline (1993-1997) and 27 June 2006.

  10. Methods – Air Pollution Exposure • AirGIS dispersion model, sum of: 1) regionalbackground, 2) urbanbackground, & 3) streetlevelcontribution • Input for AirGIS model • Street/building geometry • Street network and traffic data • Meteorology Traffic counts, emission factors, density, speed, types, variation patterns over time GIS Mapsbuildingheight, streetwidth, opensector

  11. Methods – Air Pollution Exposure • AirGIS Model output: • Annual mean NO2 /NOx concentrations at individual address Flow and dispersion inside a street canyon

  12. Methods – Statistical Model • Cox proportional hazards model, left truncation at age at baseline, and right censoring at age at hospital admission for ACS, death, emigration, or 27 June 2006 • NO2 /NOx ,time-dependent variables, the estimates per IQR • Confounders: smoking (status, intensity, duration, ETS), occupational exposures, BMI, educational level, fruit consumption • Effect modification: interaction term, Wald-test • Spline (rcs) in R, for dose-repsonse curve

  13. Results • Exclusions: • 571 cancer before baseline • 962 missing address or geocode • 1 341 missing address • 1 147 self-reported diabetes at baseline • 173 diabetes record in the NDR before baseline • 6 with diabetes between baseline and 01.01.1995 • 1 035 missing covariates Original Cohort Final Study Population ”All Diabetes” 7.8% diabetes originallyincluded in NDR Incidence rate: 8 per1 000 person-years Exclusion of 1163 included solely due to blood glucose measurements 5.5% diabetes ‘strict definition’ Incidence rate: 5.7 per 1 000 person-years ”Confirmed Diabetes”

  14. Results

  15. Results: Exposure to Air Pollution

  16. Results: Main Analysis Model WITHOUT waist-to-hip ratio: 1.05 (1.02-1.10) Model WITHOUT BMI and waist-to-hip ratio: 1.08 (1.04-1.12)

  17. Results: EffectModification

  18. Results: EffectModification

  19. Results: dose-response

  20. Conclusions • The risk for diabetes was weakly positively associated with increasing mean levels of traffic-related air pollution at the residence • The risk was highest in non-smokers and physically active people, those with a-priori low risk

More Related