title: Effects of woodsmoke exposure on airway inflammation in rural Guatemalan women.
abstract: BACKGROUND
  More than two-fifths of the world's population uses solid fuels, mostly biomass, for cooking. The resulting biomass smoke exposure is a major cause of chronic obstructive pulmonary disease (COPD) among women in developing countries.
  
  
  OBJECTIVE
  To assess whether lower woodsmoke exposure from use of a stove with a chimney, compared to open fires, is associated with lower markers of airway inflammation in young women.
  
  
  METHODS
  We carried out a cross-sectional analysis on a sub-cohort of participants enrolled in a randomized controlled trial in rural Guatemala, RESPIRE.
  
  
  METHODS
  We recruited 45 indigenous women at the end of the 18-month trial; 19 women who had been using the chimney stove for 18-24 months and 26 women still using open fires.
  
  
  METHODS
  We obtained spirometry and induced sputum for cell counts, gene expression of IL-8, TNF-α, MMP-9 and 12, and protein concentrations of IL-8, myeloperoxidase and fibronectin. Exhaled carbon monoxide (CO) and 48-hr personal CO tubes were measured to assess smoke exposure.
  
  
  RESULTS
  MMP-9 gene expression was significantly lower in women using chimney stoves. Higher exhaled CO concentrations were significantly associated with higher gene expression of IL-8, TNF-α, and MMP-9. Higher 48-hr personal CO concentrations were associated with higher gene expression of IL-8, TNF- α, MMP-9 and MMP-12; reaching statistical significance for MMP-9 and MMP-12.
  
  
  CONCLUSIONS
  Compared to using an open wood fire for cooking, use of a chimney stove was associated with lower gene expression of MMP-9, a potential mediator of airway remodeling. Among all participants, indoor biomass smoke exposure was associated with higher gene expression of multiple mediators of airway inflammation and remodeling; these mechanisms may explain some of the observed association between prolonged biomass smoke exposure and COPD.
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Guarnieri
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Janet V
authors.initials: JV
authors.lastname: Diaz
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Chandreyi
authors.initials: C
authors.lastname: Basu
authors.affiliation: Medical Entomology Research, University del Valle, Guatemala City, Guatemala.
authors.forename: Anaite
authors.initials: A
authors.lastname: Diaz
authors.affiliation: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Daniel
authors.initials: D
authors.lastname: Pope
authors.affiliation: Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America.
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Smith
authors.affiliation: Research Unit for General Practice, Uni Research, Bergen, Norway.
authors.forename: Tone
authors.initials: T
authors.lastname: Smith-Sivertsen
authors.affiliation: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Nigel
authors.initials: N
authors.lastname: Bruce
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, California, United States of America; School of Health and Sport Sciences, University of the Sunshine Coast, Queensland, Australia.
authors.forename: Colin
authors.initials: C
authors.lastname: Solomon
authors.affiliation: Emerging Infectious Disease Unit, University del Valle, Guatemala City, Guatemala.
authors.forename: John
authors.initials: J
authors.lastname: McCracken
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, California, United States of America; Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America.
authors.forename: John R
authors.initials: JR
authors.lastname: Balmes
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D002248:Carbon Monoxide / Q000737:chemistry; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D006166:Guatemala; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D016209:Interleukin-8 / Q000378:metabolism; D053508:Matrix Metalloproteinase 12 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology*; D012424:Rural Population; D012906:Smoke / Q000009:adverse effects*; D013147:Spirometry; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D055815:Young Adult
chemical_list: D000393:Air Pollutants; C508606:CXCL8 protein, human; D005353:Fibronectins; D016209:Interleukin-8; D012906:Smoke; D014409:Tumor Necrosis Factor-alpha; D002248:Carbon Monoxide; D009195:Peroxidase; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9; C507122:MMP12 protein, human; D053508:Matrix Metalloproteinase 12