title: Acute bronchodilator responsiveness in subjects with and without airflow obstruction in five Latin American cities: the PLATINO study.
abstract: BACKGROUND
  Acute bronchodilator responsiveness is an area of discussion in COPD. No information exists regarding this aspect of the disease from an unselected COPD population. We assessed acute bronchodilator responsiveness and factors influencing it in subjects with and without airway obstruction in an epidemiologic sample.
  
  
  METHODS
  COPD was defined by GOLD criteria (post-bronchodilator FEV(1)/FVC<0.70). In this analysis, subjects with pre-bronchodilator FEV(1)/FVC <0.70 but > or =0.70 post-bronchodilator were considered to have reversible obstruction. Bronchodilator responsiveness after albuterol 200microg was assessed using three definitions: a) FVC and/or FEV(1) increment > or =12% plus > or =200mL over baseline; b) FEV(1)> or =15% increase over baseline; and c) FEV(1) increase > or =10% of predicted value.
  
  
  RESULTS
  There were 756 healthy respiratory subjects, 481 subjects with reversible obstruction and 759 COPD subjects. Depending on the criterion used the proportion of person with acute bronchodilator responsiveness ranged between 15.0-28.2% in COPD, 11.4-21.6% in reversible obstructed and 2.7-7.2% in respiratory healthy. FEV(1) changes were lower (110.6+/-7.40 vs. 164.7+/-11.8mL) and FVC higher (146.5+/-14.2mL vs. -131.0+/-19.6mL) in COPD subjects compared with reversible obstructed. Substantial overlap in FEV(1) and FVC changes was observed among the groups. Acute bronchodilator responsiveness in COPD persons was associated with less obstruction and never smoking.
  
  
  CONCLUSIONS
  Over two-thirds of persons with COPD did not demonstrate acute bronchodilator responsiveness. The overall response was small and less than that considered as significant by ATS criteria. The overlap in FEV(1) and FVC changes after bronchodilator among the groups makes it difficult to determine a threshold for separating them.
authors.affiliation: Servicio de Neumonología, Hospital Universitario de Caracas, Facultad de Medicina, Los Chaguaramos, 1030, Universidad Central de Venezuela, Caracas, Venezuela. mmdeoca@cantv.net
authors.forename: Maria
authors.initials: M
authors.lastname: Montes de Oca
authors.forename: Rogelio
authors.initials: R
authors.lastname: Perez-Padilla
authors.forename: Carlos
authors.initials: C
authors.lastname: Tálamo
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Halbert
authors.forename: Dolores
authors.initials: D
authors.lastname: Moreno
authors.forename: Maria Victorina
authors.initials: MV
authors.lastname: Lopez
authors.forename: Adriana
authors.initials: A
authors.lastname: Muiño
authors.forename: B Jardim
authors.initials: BJ
authors.lastname: José Roberto
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Valdivia
authors.forename: Julio
authors.initials: J
authors.lastname: Pertuzé
authors.forename: B Menezes
authors.initials: BM
authors.lastname: Ana Maria
mesh_terms: D000368:Aged; D001980:Bronchi / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*