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Sood N, Wasilewski NV, Day AG, Wall T, Fisher T, Fisher JT, Lougheed MD. Methacholine-Induced Cough in the Absence of Asthma: Insights From Impulse Oscillometry. Front Physiol 2020; 11:554679. [PMID: 33123021 PMCID: PMC7573225 DOI: 10.3389/fphys.2020.554679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 09/11/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction The pathophysiologic differences between methacholine-induced cough but normal airway sensitivity (COUGH) and healthy individuals (CONTROL) are incompletely understood and may be due to differences in the bronchodilating effect of deep inspirations (DIs). The purpose of this study is to compare the bronchodilating effect of DIs in individuals with classic asthma (CA), cough variant asthma (CVA), and COUGH with CONTROL and to assess impulse oscillometry (IOS) measures as predictors of the bronchodilating effect of DIs. Methods A total of 43 adults [18 female; 44.8 ± 12.3 years (mean ± SD); n = 11 CA, n = 10 CVA, n = 7 COUGH, n = 15 CONTROL] underwent modified high-dose methacholine challenge, with IOS and partial/maximal expiratory flow volume (PEFV/MEFV) maneuvers (used to calculate DI Index) to a maximum change (Δ) in FEV1 of 50% from baseline (MAX). Cough count and dyspnea were measured at each dose. The relation between IOS parameters and DI Index was assessed at baseline and MAX using multivariable linear regression analysis. Results Cough frequency, dyspnea intensity, and baseline peripheral resistance (R5-R20) were significantly greater in COUGH compared with CONTROL (p = 0.006, p = 0.029, and p = 0.035, respectively). At MAX, the DI Index was significantly lower in COUGH (0.01 ± 0.36) compared with CA (0.67 ± 0.97, p = 0.008), CVA (0.51 ± 0.73, p = 0.012), and CONTROL (0.68 ± 0.45, p = 0.005). Fres and R5-R20 were independent IOS predictors of the DI Index. Conclusion The bronchodilating effect is impaired in COUGH and preserved in mild CA, CVA, and CONTROL. Increased peripheral airway resistance and decreased resonant frequency are associated with a decreased DI Index. COUGH is a clinical phenotype distinct from healthy normals and asthma.
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Affiliation(s)
- Nilita Sood
- Department of Medicine, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada.,Department of Biomedical and Molecular Sciences, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada
| | - Nastasia V Wasilewski
- Department of Medicine, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada.,Department of Biomedical and Molecular Sciences, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada
| | - Andrew G Day
- Kingston General Health Research Institute, Kingston Health Sciences Centre, Queen's University, Kingston, ON, Canada
| | - Taylar Wall
- Department of Medicine, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada
| | - Thomas Fisher
- Department of Medicine, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada
| | - John T Fisher
- Department of Biomedical and Molecular Sciences, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada
| | - M Diane Lougheed
- Department of Medicine, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada.,Department of Biomedical and Molecular Sciences, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada.,Kingston General Health Research Institute, Kingston Health Sciences Centre, Queen's University, Kingston, ON, Canada
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Eichenberger PA, Kurzen AC, Rijks L, Diener SN, Scherer TA, Spengler CM. Similar Airway Function after Volitional Hyperpnea in Mild-Moderate Asthmatics and Healthy Controls. Respiration 2019; 97:558-568. [PMID: 30933945 DOI: 10.1159/000496028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 12/04/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The beneficial effects of exercise training for asthmatics might relate to repetitive airway stretching. Thus, a training with more pronounced airway stretch using isolated, volitional hyperpnea (HYP) might be similarly or more effective. However, in healthy subjects, a bout of HYP training is known to cause an acute FEV1 decline. OBJECTIVE The aim of the present study was therefore to test whether these changes are more pronounced in asthmatics, possibly putting them at risk with HYP training. METHODS Nine subjects with mild-moderate asthma (confirmed by mannitol challenge) and 11 healthy subjects performed six 5-min bouts (with 6-min breaks; HYP1) and one 30-min bout (HYP2) of normocapnic HYP at 60% of maximal voluntary ventilation using warm and humid air. FEV1 and airway resistance (R5) were measured before, in breaks (HYP1), and immediately after HYP, and during 60 min of recovery. RESULTS In both groups, a significant and similar decrease in FEV1 during HYP1 (asthmatics: -3 ± 3%; healthy subjects: -2 ± 3%), after HYP1 (asthmatics: -2 ± 5%; healthy subjects: -1 ± 4%), and after HYP2 (asthmatics: -4 ± 5%; healthy subjects: -3 ± 3%), and an increase in R5 during and after both HYPs were observed. Maximal changes in FEV1 and R5 did not correlate with baseline lung function or responsiveness to mannitol. CONCLUSIONS A bout of HYP does not lead to relevant bronchoconstriction and the observed changes in lung function and airway resistance are neither of the magnitude of clinical relevance, nor do they differ from responses in healthy individuals. Thus, HYP training can safely be tested as an airway-specific exercise training alternative (or add-on) modality to regular aerobic exercise training.
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Affiliation(s)
- Philipp A Eichenberger
- Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | - Andrea C Kurzen
- Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | - Laura Rijks
- Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | - Stephanie N Diener
- Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | | | - Christina M Spengler
- Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland, .,Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland,
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