title: Ambient air pollution and racial/ethnic differences in carotid intima-media thickness in the Multi-Ethnic Study of Atherosclerosis (MESA).
abstract: BACKGROUND
  In the USA, ethnic disparities in atherosclerosis persist after accounting for known risk factors. Ambient air pollution is associated with increased levels of atherosclerosis and differs in the USA by race/ethnicity. We estimated the influence of ambient air pollution exposure to ethnic differences in common carotid intima-media thickness (IMT).
  
  
  METHODS
  We cross-sectionally studied 6347 Caucasian-American, African-American, Hispanic and Chinese adults across 6 US cities in 2000-2002. Annual ambient air pollution concentrations (fine particulate matter [PM2.5] and oxides of nitrogen [NOX]) were estimated at each participant's residence. IMT was assessed by ultrasound.
  
  
  RESULTS
  The mean IMT was 19.4 and 37.6 μm smaller for Hispanic women and men, 53.6 and 7.1 μm smaller for Chinese women and men, and 23.4 and 38.7 μm higher for African-American women and men compared with Caucasian-American women and men. After adjustment for PM2.5, the differences in IMT remained similar for Hispanic and African-American participants but was even more negative for Chinese participants (mean IMT difference of -58.4 μm for women and -15.7 μm for men) compared with Caucasian-American participants. The IMT difference in Chinese participants compared with Caucasian-American participants related to their higher PM2.5 exposures was 4.8 μm (95% CI 0.2 to 10.8) for women and 8.6 μm (95% CI 3.4 to 15.3) for men. NOX was not related to ethnic differences in IMT.
  
  
  CONCLUSIONS
  The smaller carotid IMT levels in Chinese participants were even smaller after accounting for higher PM2.5 concentrations in Chinese participants compared with Caucasian-American participants. Air pollution was not related to IMT differences in African-American and Hispanic participants compared with Caucasian-American participants.
authors.affiliation: Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Miranda R
authors.initials: MR
authors.lastname: Jones
authors.affiliation: University of Michigan School of Public Health, Ann Arbor, Michigan, USA Drexel University School of Public Health, Philadelphia, Pennsylvania, USA.
authors.forename: Ana V
authors.initials: AV
authors.lastname: Diez-Roux
authors.affiliation: University of Michigan School of Public Health, Ann Arbor, Michigan, USA.
authors.forename: Marie S
authors.initials: MS
authors.lastname: O'Neill
authors.affiliation: Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Eliseo
authors.initials: E
authors.lastname: Guallar
authors.affiliation: Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: A Richey
authors.initials: AR
authors.lastname: Sharrett
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Wendy
authors.initials: W
authors.lastname: Post
authors.affiliation: University of Washington School of Public Health, Seattle, Washington, USA.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Kaufman
authors.affiliation: Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Ana
authors.initials: A
authors.lastname: Navas-Acien
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D000397:Air Pollution / Q000009:adverse effects*; D001213:Asian / Q000706:statistics & numerical data; D050197:Atherosclerosis / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000209:etiology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000473:pathology; D059168:Carotid Intima-Media Thickness / Q000706:statistics & numerical data*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000009:adverse effects*; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects / Q000208:ethnology; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data
chemical_list: D052638:Particulate Matter
keywords: AIR POLLUTION; ARTHEROSCLEROSIS; ETHNICITY; Epidemiology of cardiovascular disease; Health inequalities