title: Bronchial hyperresponsiveness in a population of north Finland with no previous diagnosis of asthma or chronic bronchitis assessed with histamine and methacholine tests.
abstract: OBJECTIVE
  To assess the prevalence of bronchial hyperresponsiveness (BHR) in a population of north Finland among subjects with no previous diagnosis of asthma or chronic bronchitis by using histamine and methacholine challenges. The agreement between the methods was also evaluated.
  
  
  METHODS
  An epidemiological study assessing the prevalence of BHR measured with 2 direct dosimetric challenge methods. METHODS; Seventy-nine randomly selected subjects (21-73 years) were studied; 67% had respiratory or allergic symptoms. The baseline spirometry was normal or showed mild obstruction. Bronchial challenges to methacholine and histamine were performed on each subject in a randomized order. Provocative doses inducing the decrease of FEV1 by 15% and 20% (PD15FEV1 and PD20FEV1) and dose response ratios (DDR) were calculated for both tests. RESULTS; BHR with the methacholine test (PD20FEV1 < or = 2.6 mg) was found in 20% and with the histamine test (PD15FEV1 < or = 1.6 mg) in 28% of subjects; the agreement was 80% (kappa 0.45; 95% CI 0.23-0.68). In staging the severity of BHR the methods had a good agreement (weighted kappa 0.64; CI 95% 0.46-0.82). Prevalence of BHR fulfilling the criteria of the both methods was 14%.
  
  
  CONCLUSIONS
  The findings suggest that the prevalence of BHR in the population of north Finland with no previous diagnosis of asthma or chronic bronchitis is at least 14%, probably around 20%, assessed by histamine and methacholine challenge methods. The methods have a good agreement to be used for classifying the severity of BHR.
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, Helsinki, Finland. marijuu@netti.fi
authors.forename: Maria
authors.initials: M
authors.lastname: Juusela
authors.forename: Tuija
authors.initials: T
authors.lastname: Poussa
authors.forename: Jyrki
authors.initials: J
authors.lastname: Kotaniemi
authors.forename: Bo
authors.initials: B
authors.lastname: Lundbäck
authors.forename: Anssi
authors.initials: A
authors.lastname: Sovijärvi
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis; D016535:Bronchial Hyperreactivity / Q000175:diagnosis* / Q000453:epidemiology; D001985:Bronchial Provocation Tests / Q000379:methods*; D001991:Bronchitis / Q000175:diagnosis; D005260:Female; D005387:Finland / Q000453:epidemiology; D006632:Histamine; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D015995:Prevalence; D055815:Young Adult
chemical_list: D016210:Methacholine Chloride; D006632:Histamine