Long-Term Exposure to Traffic-Related Air Pollution and Diabetes: A Systematic Review and Meta-Analysis

Int J Public Health. 2023 May 31:68:1605718. doi: 10.3389/ijph.2023.1605718. eCollection 2023.

Abstract

Objectives: We report results of a systematic review on the health effects of long-term traffic-related air pollution (TRAP) and diabetes in the adult population. Methods: An expert Panel appointed by the Health Effects Institute conducted this systematic review. We searched the PubMed and LUDOK databases for epidemiological studies from 1980 to July 2019. TRAP was defined based on a comprehensive protocol. Random-effects meta-analyses were performed. Confidence assessments were based on a modified Office for Health Assessment and Translation (OHAT) approach, complemented with a broader narrative synthesis. We extended our interpretation to include evidence published up to May 2022. Results: We considered 21 studies on diabetes. All meta-analytic estimates indicated higher diabetes risks with higher exposure. Exposure to NO2 was associated with higher diabetes prevalence (RR 1.09; 95% CI: 1.02; 1.17 per 10 μg/m3), but less pronounced for diabetes incidence (RR 1.04; 95% CI: 0.96; 1.13 per 10 μg/m3). The overall confidence in the evidence was rated moderate, strengthened by the addition of 5 recently published studies. Conclusion: There was moderate evidence for an association of long-term TRAP exposure with diabetes.

Keywords: NO2; confidence assessment; diabetes; particulate matter; traffic-related air pollution.

Publication types

  • Meta-Analysis
  • Systematic Review
  • Review

MeSH terms

  • Adult
  • Air Pollutants* / adverse effects
  • Air Pollutants* / analysis
  • Air Pollution* / adverse effects
  • Air Pollution* / analysis
  • Diabetes Mellitus* / epidemiology
  • Diabetes Mellitus* / etiology
  • Environmental Exposure / adverse effects
  • Environmental Exposure / analysis
  • Humans
  • Incidence
  • Particulate Matter / analysis

Substances

  • Air Pollutants
  • Particulate Matter

Grants and funding

Research described in this article was conducted under contract to the HEI, an organization jointly funded by the United States Environmental Protection Agency (EPA) [Assistance Award No. CR-83998101] and certain motor vehicle and engine manufacturers. MKJ work is supported by the Swiss Federal Office for the Environment [Grant No. 17.0094.PJ/R192-0332] as part of its funding for the work of the LUDOK-database. The funders were not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.