Methacholine-Induced Cough in the Absence of Asthma: Insights From Impulse Oscillometry

• DOI: 10.3389/fphys.2020.554679
• Publication Date: 2020-10-06T06:02:05Z
• Authors: Nilita Sood; Nastasia V. Wasil...; Andrew G. Day; Taylar Wall; Thomas Fisher; John T. Fisher; M. Diane Lougheed
• Keywords: Methacholine; Chronic Cough

The pathophysiologic differences between methacholine-induced cough but normal airway sensitivity (COUGH) and healthy individuals (CONTROL) are incompletely understood may be due to in the bronchodilating effect of deep inspirations (DIs). purpose this study is compare DIs with classic asthma (CA), variant (CVA), COUGH CONTROL assess impulse oscillometry (IOS) measures as predictors DIs.A total 43 adults [18 female; 44.8 ± 12.3 years (mean SD); n = 11 CA, 10 CVA, 7 COUGH, 15 CONTROL] underwent modified high-dose methacholine challenge, IOS partial/maximal expiratory flow volume (PEFV/MEFV) maneuvers (used calculate DI Index) a maximum change (Δ) FEV1 50% from baseline (MAX). Cough count dyspnea were measured at each dose. relation parameters Index was assessed MAX using multivariable linear regression analysis.Cough frequency, intensity, peripheral resistance (R5-R20) significantly greater compared (p 0.006, p 0.029, 0.035, respectively). At MAX, lower (0.01 0.36) CA (0.67 0.97, 0.008), CVA (0.51 0.73, 0.012), (0.68 0.45, 0.005). Fres R5-R20 independent Index.The impaired preserved mild CONTROL. Increased decreased resonant frequency associated Index. clinical phenotype distinct normals asthma.