title: Secondhand smoke exposure and inflammatory markers in nonsmokers in the trucking industry.
abstract: BACKGROUND
  Few studies have directly assessed the association of secondhand smoke (SHS) with cardiovascular disease-related inflammatory markers, and the findings are inconsistent.
  
  
  OBJECTIVE
  We assessed the association between SHS exposure and the inflammatory markers high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and soluble intercellular adhesion molecule-1 (sICAM-1) in 199 nonsmoking U.S. trucking industry workers.
  
  
  METHODS
  Participants provided blood samples either by mail (blood drawn at local health care provider near home) or at the work site (blood drawn by research staff on-site) and completed a health and work history questionnaire at the time of blood draw. Exposure to SHS was measured by plasma cotinine concentrations. We used multivariate regression analyses to assess the associations between levels of cotinine and inflammatory markers.
  
  
  RESULTS
  The median cotinine level was 0.10 ng/mL (interquartile range, 0.04-0.23 ng/mL). The odds ratios of elevated hs-CRP (above highest CRP tertile, 1.5 mg/L) were 2.85 [95% confidence interval (CI), 1.03-7.89] for the high-cotinine group (> 0.215 ng/mL) and 2.80 (95% CI, 1.11-7.10) for the moderate-cotinine group (0.05-0.215 ng/mL), compared with the low-cotinine group (< 0.05 ng/mL), adjusting for age, sex, race, educational level, obesity, previous smoking history, job title, and medical history. Plasma cotinine levels were not associated with IL-6 or sICAM-1.
  
  
  CONCLUSIONS
  SHS exposure, as assessed by plasma cotinine, was positively associated with hs-CRP in this group of blue-collar workers. The strength of the association with hs-CRP depended on the cut points selected for analysis.
authors.affiliation: Exposure, Epidemiology and Risk Program, Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA. yhchiu@gsph.harvard.edu
authors.forename: Yueh-Hsiu Mathilda
authors.initials: YH
authors.lastname: Chiu
authors.forename: Donna
authors.initials: D
authors.lastname: Spiegelman
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Dockery
authors.forename: Eric
authors.initials: E
authors.lastname: Garshick
authors.forename: S Katharine
authors.initials: SK
authors.lastname: Hammond
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Smith
authors.forename: Jaime E
authors.initials: JE
authors.lastname: Hart
authors.forename: Francine
authors.initials: F
authors.lastname: Laden
mesh_terms: D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D003367:Cotinine / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018986:Motor Vehicles; D015999:Multivariate Analysis; D016273:Occupational Exposure; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution; D014481:United States
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014028:Tobacco Smoke Pollution; D018799:Intercellular Adhesion Molecule-1; D002097:C-Reactive Protein; D003367:Cotinine