title: [Airway oxidative stress and inflammation markers in chronic obstructive pulmonary diseases(COPD) patients are linked with exposure to traffic-related air pollution: a panel study].
abstract: OBJECTIVE
  To investigate the effects of short-term exposure to traffic-related air pollution on airway oxidative stress and inflammation in chronic obstructive pulmonary diseases (COPD) patients.
  
  
  METHODS
  A panel of forty-five diagnosed COPD patients were recruited and followed with repeated measurements of biomarkers reflecting airway oxidative stress and inflammation in exhaled breath condensate (EBC), including nitrate and nitrite, 8-isoprostane, interleukin-8 and acidity of EBC (pH), between 5(th) September in 2014 and 26(th) May in 2015. The associations between air pollution and biomarkers were analyzed with mixed-effects models, controlling for confounding covariates.
  
  
  RESULTS
  The concentration of PM2.5, black carbon, NO2 and number concentration of particles with diameter less than 100 nm (PNC100), and particles in size ranges between 100 nm to 200 nm (PNC100-200) during the first follow-up were (156.5±117.7), (10.7±0.7), (165.9±66.0)μg/m(3) and 397 521±96 712, 79 421±44 090 per cubic meter, respectively; the concentration were (67.9±29.6), (3.4±1.3), (126.1±10.9) μg/m(3) and (295 682±39 430), (24 693±12 369) per cubic meter, respectively during the second follow-up. The differences were of significance, with t value being 3.10, 4.42, 2.61, 4.02, 5.12, respectively and P value being 0.005,<0.001, 0.016, <0.001 and <0.001, respectively. In our COPD-patient panel, per interquartile range (IQR) increase in PNC100-200, we observed an increase of 65% (95% CI: 8%-152%) in nitrate and nitrite in EBC reflecting airway oxidative stress. For an IQR increase in PM2.5, black carbon and PNC100-200, respective increases of 0.17 ng/ml (95% CI: 0.02-0.33), 0.12 ng/ml (95% CI: 0.01-0.24) and 0.13 ng/ml (95% CI:0.02-0.24) in interleukin-8 in EBC reflecting airway inflammation were also observed. An IQR increase in ozone was also associated with a 0.24 (95%CI: 0.05-0.42) decrease in pH of EBC reflecting increased airway inflammation. No significant association observed between air pollution and 8-isoprostane in EBC in COPD patients.
  
  
  CONCLUSIONS
  Our results suggested that short-term exposure to traffic-related air pollution was responsible for exacerbation of airway oxidative stress and inflammation in COPD patients.
authors.affiliation: Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: Q
authors.initials: Q
authors.lastname: Zhao
authors.forename: B B
authors.initials: BB
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: H B
authors.initials: HB
authors.lastname: Xu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: X M
authors.initials: XM
authors.lastname: Song
authors.forename: B
authors.initials: B
authors.lastname: He
authors.forename: W
authors.initials: W
authors.lastname: Huang
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis; D015415:Biomarkers / Q000378:metabolism; D015237:Dinoprost / Q000031:analogs & derivatives; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology / Q000378:metabolism*; D016209:Interleukin-8; D008137:Longitudinal Studies; D008297:Male; D018986:Motor Vehicles; D018384:Oxidative Stress / Q000187:drug effects*; D052638:Particulate Matter / Q000032:analysis; D029424:Pulmonary Disease, Chronic Obstructive; D012137:Respiratory System / Q000737:chemistry*; D053260:Soot / Q000032:analysis / Q000633:toxicity*; D014505:Urban Population; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D015415:Biomarkers; C508606:CXCL8 protein, human; D016209:Interleukin-8; D052638:Particulate Matter; D053260:Soot; D001335:Vehicle Emissions; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost