title: Air pollution and atherosclerosis: a cross-sectional analysis of four European cohort studies in the ESCAPE study.
abstract: BACKGROUND
  In four European cohorts, we investigated the cross-sectional association between long-term exposure to air pollution and intima-media thickness of the common carotid artery (CIMT), a preclinical marker of atherosclerosis.
  
  
  METHODS
  Individually assigned levels of nitrogen dioxide, nitrogen oxides, particulate matter ≤ 2.5 μm (PM2.5), absorbance of PM2.5 (PM2.5abs), PM10, PMcoarse, and two indicators of residential proximity to highly trafficked roads were obtained under a standard exposure protocol (European Study of Cohorts for Air Pollution Effects-ESCAPE study) in the Stockholm area (Sweden), the Ausburg and Ruhr area (Germany), and the Girona area (Spain). We used linear regression and meta-analyses to examine the association between long-term exposure to air pollution and CIMT.
  
  
  RESULTS
  The meta-analysis with 9,183 individuals resulted in an estimated increase in CIMT (geometric mean) of 0.72% (95% CI: -0.65%, 2.10%) per 5-μg/m3 increase in PM2.5 and 0.42% (95% CI: -0.46%, 1.30%) per 10-5/m increase in PM2.5abs. Living in proximity to high traffic was also positively but not significantly associated with CIMT. Meta-analytic estimates for other pollutants were inconsistent. Results were similar across different adjustment sets and sensitivity analyses. In an extended meta-analysis for PM2.5 with three other previously published studies, a 0.78% (95% CI: -0.18%, 1.75%) increase in CIMT was estimated for a 5-μg/m3 contrast in PM2.5.
  
  
  CONCLUSIONS
  Using a standardized exposure and analytical protocol in four European cohorts, we found that cross-sectional associations between CIMT and the eight ESCAPE markers of long-term residential air pollution exposure did not reach statistical significance. The additional meta-analysis of CIMT and PM2.5 across all published studies also was positive but not significant.
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors.forename: Laura
authors.initials: L
authors.lastname: Perez
authors.forename: Kathrin
authors.initials: K
authors.lastname: Wolf
authors.forename: Frauke
authors.initials: F
authors.lastname: Hennig
authors.forename: Johanna
authors.initials: J
authors.lastname: Penell
authors.forename: Xavier
authors.initials: X
authors.lastname: Basagaña
authors.forename: Maria
authors.initials: M
authors.lastname: Foraster
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Aguilera
authors.forename: David
authors.initials: D
authors.lastname: Agis
authors.forename: Rob
authors.initials: R
authors.lastname: Beelen
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
authors.forename: Josef
authors.initials: J
authors.lastname: Cyrys
authors.forename: Kateryna B
authors.initials: KB
authors.lastname: Fuks
authors.forename: Martin
authors.initials: M
authors.lastname: Adam
authors.forename: Damiano
authors.initials: D
authors.lastname: Baldassarre
authors.forename: Marta
authors.initials: M
authors.lastname: Cirach
authors.forename: Roberto
authors.initials: R
authors.lastname: Elosua
authors.forename: Julia
authors.initials: J
authors.lastname: Dratva
authors.forename: Regina
authors.initials: R
authors.lastname: Hampel
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Koenig
authors.forename: Jaume
authors.initials: J
authors.lastname: Marrugat
authors.forename: Ulf
authors.initials: U
authors.lastname: de Faire
authors.forename: Göran
authors.initials: G
authors.lastname: Pershagen
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Probst-Hensch
authors.forename: Audrey
authors.initials: A
authors.lastname: de Nazelle
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Nieuwenhuijsen
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rathmann
authors.forename: Marcela
authors.initials: M
authors.lastname: Rivera
authors.forename: Jochen
authors.initials: J
authors.lastname: Seissler
authors.forename: Christian
authors.initials: C
authors.lastname: Schindler
authors.forename: Joachim
authors.initials: J
authors.lastname: Thiery
authors.forename: Barbara
authors.initials: B
authors.lastname: Hoffmann
authors.forename: Annette
authors.initials: A
authors.lastname: Peters
authors.forename: Nino
authors.initials: N
authors.lastname: Künzli
mesh_terms: D000328:Adult; D000368:Aged; D000397:Air Pollution / Q000009:adverse effects*; D050197:Atherosclerosis / Q000139:chemically induced / Q000453:epidemiology*; D015415:Biomarkers / Q000032:analysis; D059168:Carotid Intima-Media Thickness / Q000706:statistics & numerical data; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D015415:Biomarkers