title: Airway hyperresponsiveness and quality of life in Western red cedar asthmatics removed from exposure.
abstract: OBJECTIVE
  Most western red cedar asthmatics (WRCA) continue to have symptoms even after removal from exposure. Consequently, health-related quality of life (HRQL) is often impaired. The objective of this study was to evaluate the relationship between two measures of AHR and HRQL scores in those with WRCA.
  
  
  METHODS
  HRQL was determined by the short form 36 (SF-36) in 46 male, non-smoking individuals with WRCA removed from exposure to western red cedar, on average, 15 years earlier. The relationships between the SF-36 total score and its eight domains with 2 indices from methacholine-stimulated airway hyperresponsiveness (the provocative concentration of methacholine causing a 20% fall in FEV(1) [PC(20)] and bronchial reactivity index [BRI]) were analyzed by the Pearson correlation and multiple linear regression.
  
  
  RESULTS
  PC(20) was significantly correlated with the SF-36 total score and its two domains of bodily pain and general health (r = 0.34, 0.40, 0.40, p = 0.023, 0.006, 0.006, respectively). BRI was significantly correlated with bodily pain and general health (r = -0.35, -0.42, p = 0.017, 0.004, respectively); correlations remain significant after adjusting for age, ethnicity, years since diagnosis, years since last exposure and use of inhaled corticosteroid. BRI and other measures of airway responsiveness were not associated with inhaled corticosteroids use.
  
  
  CONCLUSIONS
  In Western red cedar asthmatics removed from exposure, measures of airway responsiveness are associated with HRQL.
authors.affiliation: Department of Respiratory Medicine. West China Hospital, West China Medical School, Sichuan University, Chengdu, China. jianqing.he@hli.ubc.ca
authors.forename: Jian-Qing
authors.initials: JQ
authors.lastname: He
authors.forename: Moira
authors.initials: M
authors.lastname: Chan-Yeung
authors.forename: Chris
authors.initials: C
authors.lastname: Carlsten
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D003710:Demography; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage; D008875:Middle Aged; D011788:Quality of Life; D013147:Spirometry; D011795:Surveys and Questionnaires; D029783:Thuja / Q000276:immunology*
chemical_list: D000305:Adrenal Cortex Hormones; D016210:Methacholine Chloride