Inflammation and acute traffic-related air pollution exposures among a cohort of youth with type 1 diabetes

Environ Int. 2019 Nov;132:105064. doi: 10.1016/j.envint.2019.105064. Epub 2019 Aug 13.

Abstract

Background: Evidence remains equivocal regarding the association of inflammation, a precursor to cardiovascular disease, and acute exposures to ambient air pollution from traffic-related particulate matter. Though youth with type 1 diabetes are at higher risk for cardiovascular disease, the relationship of inflammation and ambient air pollution exposures in this population has received little attention.

Objectives: Using five geographically diverse US sites from the racially- and ethnically-diverse SEARCH for Diabetes in Youth Cohort, we examined the relationship of acute exposures to PM2.5 mass, Atmospheric Dispersion Modeling System (ADMS)-Roads traffic-related PM concentrations near roadways, and elemental carbon (EC) with biomarkers of inflammation including interleukin-6 (IL-6), c-reactive protein (hs-CRP) and fibrinogen.

Methods: Baseline questionnaires and blood were obtained at a study visit. Using a spatio-temporal modeling approach, pollutant exposures for 7 days prior to blood draw were assigned to residential addresses. Linear mixed models for each outcome and exposure were adjusted for demographic and lifestyle factors identified a priori.

Results: Among the 2566 participants with complete data, fully-adjusted models showed positive associations of EC average week exposures with IL-6 and hs-CRP, and PM2.5 mass exposures on lag day 3 with IL-6 levels. Comparing the 25th and 75th percentiles of average week EC exposures resulted in 8.3% higher IL-6 (95%CI: 2.7%,14.3%) and 9.8% higher hs-CRP (95%CI: 2.4%,17.7%). We observed some evidence of effect modification for the relationships of PM2.5 mass exposures with hs-CRP by gender and with IL-6 by race/ethnicity.

Conclusions: Indicators of inflammation were associated with estimated traffic-related air pollutant exposures in this study population of youth with type 1 diabetes. Thus youth with type 1 diabetes may be at increased risk of air pollution-related inflammation. These findings and the racial/ethnic and gender differences observed deserve further exploration.

Keywords: Diabetes; Inflammation; Traffic-related air pollution.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Air Pollutants / analysis*
  • Air Pollution / analysis
  • Biomarkers / blood
  • C-Reactive Protein / analysis
  • Carbon / analysis
  • Child
  • Cohort Studies
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / epidemiology
  • Environmental Exposure / analysis*
  • Female
  • Fibrinogen / analysis
  • Humans
  • Inflammation / blood*
  • Inflammation / epidemiology
  • Interleukin-6 / blood
  • Male
  • Particulate Matter / analysis
  • United States / epidemiology
  • Vehicle Emissions / analysis*

Substances

  • Air Pollutants
  • Biomarkers
  • IL6 protein, human
  • Interleukin-6
  • Particulate Matter
  • Vehicle Emissions
  • Carbon
  • Fibrinogen
  • C-Reactive Protein