title: High prevalence of current asthma and active smoking effect among the elderly.
abstract: BACKGROUND
  Although asthma is a common cause of morbidity in adults, relatively few objectively measured population studies of asthma prevalence in adult populations have been conducted.
  
  
  OBJECTIVE
  To evaluate the prevalence of asthma, based on both a questionnaire and methacholine bronchial provocation test, and to determine the risk factors of asthma prevalence in an adult population.
  
  
  METHODS
  A total of 2,467 adults, who were randomly selected from metropolitan urban, non-metropolitan urban and rural areas, responded to the modified ISAAC questionnaire, and underwent methacholine bronchial provocation tests and skin prick tests to locally common aeroallergens.
  
  
  RESULTS
  The prevalence of current asthma based on the questionnaire and the methacholine challenge was 2.0% in adults younger than 40, 3.8% in 40- to 54-year-olds, 7.7% in 55- to 64-year-olds and 12.7% in those aged 65 or higher. For subjects of 55-64 years, active smoking was found to be significantly related with the prevalence of current asthma and bronchial hyper-responsiveness, although smoking was positively associated with percentage predictive value of forced expiratory volume of 1 s (FEV1).
  
  
  CONCLUSIONS
  The prevalence of current asthma is common among the elderly, and active smoking may play an important role in the development of asthma and bronchial hyper-responsiveness among the elderly.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Y K
authors.initials: YK
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: Y J
authors.initials: YJ
authors.lastname: Tak
authors.forename: Y K
authors.initials: YK
authors.lastname: Jee
authors.forename: B J
authors.initials: BJ
authors.lastname: Lee
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: H W
authors.initials: HW
authors.lastname: Park
authors.forename: J W
authors.initials: JW
authors.lastname: Jung
authors.forename: J W
authors.initials: JW
authors.lastname: Bahn
authors.forename: Y S
authors.initials: YS
authors.lastname: Chang
authors.forename: D C
authors.initials: DC
authors.lastname: Choi
authors.forename: S I
authors.initials: SI
authors.lastname: Chang
authors.forename: K U
authors.initials: KU
authors.lastname: Min
authors.forename: Y Y
authors.initials: YY
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Cho
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology* / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology; D007723:Korea / Q000453:epidemiology; D016015:Logistic Models; D008168:Lung / Q000503:physiopathology; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D015995:Prevalence; D012423:Rural Health; D012882:Skin Tests; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D014504:Urban Health
chemical_list: D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride