title: PHYSIOLOGIC AIRWAY RESPONSES TO INHALED HISTAMINE AND ACETYLCHOLINE IN PATIENTS WITH MILD ASTHMA AS ANALYZED BY FORCED OSCILLATION.
abstract: Asthma is a chronic disease characterized by airway inflammation; it is sometimes difficult to diagnose. For clinical diagnosis, forced oscillation technique (FOT) measures airway reactance and resistance. By FOT, we investigated respiratory resistance and ventilation perfusion ratio inequality in adults with mild asthma.
  
  
  
  We examined 58 adult patients with mild asthma having no inhaled corticosteroid treatment, and 10 adult patients with post-infectious prolonged cough. Using a MostGraph-01 FOT instrument, we evaluated these patients before and after bronchial hyperresponsiveness to acetylcholine (ACh) or histamine (Hist). We measured the following conditions: change of resistance at 5Hz (R5) and 20Hz (R20), R5-R20, reactance at 5Hz, frequency of resonance (Fres), low-frequency reactance area (ALX), and forced expiratory volume in 1 second (FEV1).
  
  
  
  There were significant changes of R5, R20, R5-R20, X5, Fres, ALX after provocations for ACh or Hist in all patients with asthma, but not in patients with post-infectious prolonged cough. We calculated the percent decrease in FEV1 after provocation with ACh or Hist. For Ach, this decrease in FEV1 correlated with changes in R20 and Fres for all patients. For Hist, the percent decrease in FEV1 correlated with changes in R5, R20, Fres, and ALX for all patients. Furthermore, we investigated these correlations in patients with normalized bronchial hyperresponsiveness to ACh or Hist. For Ach, the percent decrease in FEV1 correlated with changes in Fres or R5-R20. For Hist, this decrease in FEV1 correlated with changes in R5, R20, and Fres. ROC analysis was used to evaluate the diagnostic value of the ratio of change of Fres in BHR to Hist. The area under the curve was 0.7808 (95% CI=0.657-0.904). A reasonably high specificity (100.0%) and a high sensitivity (53.8%) with a cut-off point of 1.5 in the ratio before and after of Fres were obtained.
  
  
  
  The changes in FOT parameters (before and after bronchial airway responses) may detect airway resistance and ventilation perfusion ratio inequality even in adult patients with asthma having normalized bronchial hyperresponsiveness to ACh or Hist. That results may be useful for an early diagnosis of asthma.
authors.affiliation: National Hospital Organization, Sagamihara National Hospital.
authors.forename: Naomi
authors.initials: N
authors.lastname: Tsurikisawa
authors.forename: Chiyako
authors.initials: C
authors.lastname: Oshikata
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsuburai
authors.forename: Mina
authors.initials: M
authors.lastname: Asaji
authors.forename: Natsumi
authors.initials: N
authors.lastname: Saito
authors.forename: Kentaro
authors.initials: K
authors.lastname: Watai
authors.forename: Arisa
authors.initials: A
authors.lastname: Kinoshita
authors.forename: Yu
authors.initials: Y
authors.lastname: Sato
authors.forename: Masanori
authors.initials: M
authors.lastname: Fukuhara
authors.forename: Takafumi
authors.initials: T
authors.lastname: Minami
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Hayashi
authors.forename: Hidenori
authors.initials: H
authors.lastname: Tanimoto
authors.forename: Jun
authors.initials: J
authors.lastname: Ito
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Sekiya
authors.forename: Mamoru
authors.initials: M
authors.lastname: Otomo
authors.forename: Yuji
authors.initials: Y
authors.lastname: Maeda
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Suzuki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Akiyama
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D001249:Asthma / Q000503:physiopathology*; D001980:Bronchi / Q000503:physiopathology; D005260:Female; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D014692:Ventilation-Perfusion Ratio
chemical_list: D006632:Histamine; D000109:Acetylcholine