title: FEV1 decline in patients with chronic obstructive pulmonary disease associated with biomass exposure.
abstract: BACKGROUND
  Biomass exposure is an important risk factor for chronic obstructive pulmonary disease (COPD). However, the time-course behavior of FEV1 in subjects exposed to biomass is unknown.
  
  
  OBJECTIVE
  We undertook this study to determine the FEV1 rate decline in subjects exposed to biomass.
  
  
  METHODS
  Pulmonary function was assessed every year in a Mexican cohort of patients with COPD associated with biomass or tobacco during a 15-year follow-up period.
  
  
  RESULTS
  The mean rate of decline was significantly lower for the biomass exposure COPD group (BE-COPD) than for the tobacco smoke COPD group (TS-COPD) (23 vs. 42 ml, respectively; P < 0.01). Of the TS-COPD group, 11% were rapid decliners, whereas only one rapid decliner was found in the BE-COPD group; 69 and 21% of smokers versus 17 and 83% of the BE-COPD group were slow decliners and sustainers, respectively. A higher FEV1 both as % predicted and milliliters was a predictive factor for decline for BE-COPD and TS-COPD, whereas reversibility to bronchodilator was a predictive factor for both groups when adjusted by FEV1% predicted and only for the TS-COPD group when adjusted by milliliters.
  
  
  CONCLUSIONS
  In the biomass exposure COPD group the rate of FEV1 decline is slower and shows a more homogeneous rate of decline over time in comparison with smokers. The rapid rate of FEV1 decline is a rare feature of biomass-induced airflow limitation.
authors.affiliation: Departamento de Investigación en Tabaquismo y EPOC, Instituto Nacional de Enfermedades Respiratorias, Ismael Cosio Villegas, Mexico City, Mexico.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Ramírez-Venegas
authors.forename: Raul H
authors.initials: RH
authors.lastname: Sansores
authors.forename: Roger H
authors.initials: RH
authors.lastname: Quintana-Carrillo
authors.forename: Monica
authors.initials: M
authors.lastname: Velázquez-Uncal
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Hernandez-Zenteno
authors.forename: Candelaria
authors.initials: C
authors.lastname: Sánchez-Romero
authors.forename: Alejandra
authors.initials: A
authors.lastname: Velazquez-Montero
authors.forename: Fernando
authors.initials: F
authors.lastname: Flores-Trujillo
mesh_terms: D000368:Aged; D018533:Biomass; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012906:Smoke / Q000009:adverse effects*; D012907:Smoking / Q000503:physiopathology
chemical_list: D012906:Smoke
keywords: biomass exposure; lung function decline; phenotypes