title: [Studies on airway hyperresponsiveness by the Astograph(r) method in asthmatics and young adult non-asthmatic asymptomatics].
abstract: We investigated airway hyperresponsiveness (AHR) by the continuous inhalation method using an Astograph(R) in 105 asthmatics and 141 non-asthmatic asymptomatics. The range of Dmin (1 U=one minute inhalation of 1 mg/ml of methacholine) of asthmatics was 0.001 to 28.70 U, and that of adjusted Dmin of non-asthmatic asymptomatics was 0.28 to 190 U; thus, an apparent overlap was recognized in the distributions of Dmin. Ninety-five percent of asthmatics had a Dmin lower than 7 U, and 95% of non-asthmatic asymptomatics had a Dmin higher than 0.9 U. Presuming that almost all asthmatics had AHR, it was inferred that nearly half of non-asthmatic asymptomatics had AHR, too. Comparison with previous reports suggests that AHR in healthy people may be increasing generally. When Dmin is determined to be>7 U by the Astograph(R) method, it is likely that the patient does not have asthma. When a patient has a Dmin<0.9 U, it is highly probable that the patient has asthma.
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Hokkaido, Japan. yo-fukui@med.hokudai.ac.jp
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Fukui
authors.forename: Etsuro
authors.initials: E
authors.lastname: Yamaguchi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hizawa
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Maeda
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takahashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Konno
authors.forename: Motoko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hosokawa
authors.forename: Eisei
authors.initials: E
authors.lastname: Jinushi
authors.forename: Kei
authors.initials: K
authors.lastname: Takamura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Nasuhara
authors.forename: Masaharu
authors.initials: M
authors.lastname: Nishimura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged
chemical_list: D016210:Methacholine Chloride