title: Circulating biomarkers of inflammation, antioxidant activity, and platelet activation are associated with primary combustion aerosols in subjects with coronary artery disease.
abstract: BACKGROUND
  Biomarkers of systemic inflammation have been associated with risk of cardiovascular morbidity and mortality.
  
  
  OBJECTIVE
  We aimed to clarify associations of particulate matter (PM) air pollution with systemic inflammation using models based on size-fractionated PM mass and markers of primary and secondary aerosols.
  
  
  METHODS
  We followed a panel of 29 nonsmoking elderly subjects with a history of coronary artery disease (CAD) living in retirement communities in the Los Angeles, California, air basin. Blood plasma biomarkers were measured weekly over 12 weeks and included C-reactive protein (CRP), fibrinogen, tumor necrosis factor-alpha (TNF-alpha) and its soluble receptor-II (sTNF-RII), interleukin-6 (IL-6) and its soluble receptor (IL-6sR), fibrin D-dimer, soluble platelet selectin (sP-selectin), soluble vascular cell adhesion molecule-1 (sVCAM-1), intracellular adhesion molecule-1 (sICAM-1), and myeloperoxidase (MPO). To assess changes in antioxidant capacity, we assayed erythrocyte lysates for glutathione peroxidase-1 (GPx-1) and copper-zinc superoxide dismutase (Cu,Zn-SOD) activities. We measured indoor and outdoor home daily size-fractionated PM mass, and hourly pollutant gases, total particle number (PN), fine PM elemental carbon (EC) and organic carbon (OC), estimated secondary organic aerosol (SOA) and primary OC (OCpri) from total OC, and black carbon (BC). We analyzed data with mixed models controlling for temperature and excluding weeks with infections.
  
  
  RESULTS
  We found significant positive associations for CRP, IL-6, sTNF-RII, and sP-selectin with outdoor and/or indoor concentrations of quasi-ultrafine PM < or = 0.25 microm in diameter, EC, OCpri, BC, PN, carbon monoxide, and nitrogen dioxide from the current-day and multiday averages. We found consistent positive but largely nonsignificant coefficients for TNF-alpha, sVCAM-1, and sICAM-1, but not fibrinogen, IL-6sR, or D-dimer. We found inverse associations for erythrocyte Cu,Zn-SOD with these pollutants and other PM size fractions (0.25-2.5 and 2.5-10 microm). Inverse associations of GPx-1 and MPO with pollutants were largely nonsignificant. Indoor associations were often stronger for estimated indoor EC, OCpri, and PN of outdoor origin than for uncharacterized indoor measurements. There was no evidence for positive associations with SOA.
  
  
  CONCLUSIONS
  Results suggest that traffic emission sources of OCpri and quasi-ultrafine particles lead to increased systemic inflammation and platelet activation and decreased antioxidant enzyme activity in elderly people with CAD.
authors.affiliation: Department of Epidemiology, School of Medicine, University of California, Irvine, Irvine, California 92617-7555, USA. rdelfino@uci.edu
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Delfino
authors.forename: Norbert
authors.initials: N
authors.lastname: Staimer
authors.forename: Thomas
authors.initials: T
authors.lastname: Tjoa
authors.forename: Andrea
authors.initials: A
authors.lastname: Polidori
authors.forename: Mohammad
authors.initials: M
authors.lastname: Arhami
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Gillen
authors.forename: Micheal T
authors.initials: MT
authors.lastname: Kleinman
authors.forename: Nosratola D
authors.initials: ND
authors.lastname: Vaziri
authors.forename: John
authors.initials: J
authors.lastname: Longhurst
authors.forename: Frank
authors.initials: F
authors.lastname: Zaldivar
authors.forename: Constantinos
authors.initials: C
authors.lastname: Sioutas
mesh_terms: D000336:Aerosols; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003324:Coronary Artery Disease / Q000097:blood / Q000378:metabolism*; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D015539:Platelet Activation; D012306:Risk
chemical_list: D000336:Aerosols; D015415:Biomarkers; D052638:Particulate Matter