Does increased baseline ventilation heterogeneity following chest wall strapping predispose to airway hyperresponsiveness?

Chapman, DG; Berend, N; Horlyck, KR; King, GG; Salome, CM

Does increased baseline ventilation heterogeneity following chest wall strapping predispose to airway hyperresponsiveness?

Chapman, DG

Berend, N Horlyck, KR King, GG Salome, CM

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Publication Type:: Journal Article
Citation:: Journal of Applied Physiology, 2012, 113 (1), pp. 25 - 30
Issue Date:: 2012-07-01

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Field	Value	Language
dc.contributor.author	Chapman, DG https://orcid.org/0000-0002-8211-1817	en_US
dc.contributor.author	Berend, N	en_US
dc.contributor.author	Horlyck, KR	en_US
dc.contributor.author	King, GG	en_US
dc.contributor.author	Salome, CM	en_US
dc.date.issued	2012-07-01	en_US
dc.identifier.citation	Journal of Applied Physiology, 2012, 113 (1), pp. 25 - 30	en_US
dc.identifier.issn	8750-7587	en_US
dc.identifier.uri	http://hdl.handle.net/10453/115286
dc.description.abstract	Baseline ventilation heterogeneity is associated with airway hyperresponsiveness (AHR) in asthma; however, it is unknown whether increased baseline ventilation heterogeneity leads to AHR or both are independent effects of similar disease pathophysiology. Reducing functional residual capacity (FRC) in healthy subjects increases baseline ventilation heterogeneity and airway responsiveness, but the relationship between the two is unclear. The aim was to determine whether an increase in baseline ventilation heterogeneity due to a reduction in FRC correlated with the increase in response to methacholine. In 13 healthy male subjects, ventilation heterogeneity was measured by multiple-breath N2 washout before a cumulative high-dose (0.79-200 μmol) methacholine challenge. On a separate day, the protocol was performed with chest wall strapping (CWS) to reduce FRC. Indexes of ventilation heterogeneity in the convection-dependent (Scond) and diffusion-convection- dependent (Sacin) airways were calculated from the multiple-breath N2 washout. CWS decreased FRC by 15.6 ± 2.7% (P < 0.0001). CWS increased the percent fall in forced expiratory volume in 1 s during bronchial challenge (P = 0.006), and the magnitude of this effect was independently determined by the effect of CWS on Sacin and FRC (radj2 = 0.55, P = 0.02). This suggests that changes in baseline ventilation heterogeneity in healthy subjects are sufficient to increase airway responsiveness, independent of the presence of disease pathology. © 2012 the American Physiological Society.	en_US
dc.relation.ispartof	Journal of Applied Physiology	en_US
dc.relation.isbasedon	10.1152/japplphysiol.01582.2011	en_US
dc.subject.classification	Physiology	en_US
dc.subject.mesh	Thoracic Wall	en_US
dc.subject.mesh	Humans	en_US
dc.subject.mesh	Respiratory Hypersensitivity	en_US
dc.subject.mesh	Methacholine Chloride	en_US
dc.subject.mesh	Parasympathomimetics	en_US
dc.subject.mesh	Respiratory Function Tests	en_US
dc.subject.mesh	Bronchial Provocation Tests	en_US
dc.subject.mesh	Respiration	en_US
dc.subject.mesh	Adult	en_US
dc.subject.mesh	Male	en_US
dc.subject.mesh	Young Adult	en_US
dc.title	Does increased baseline ventilation heterogeneity following chest wall strapping predispose to airway hyperresponsiveness?	en_US
dc.type	Journal Article
utslib.citation.volume	1	en_US
utslib.citation.volume	113	en_US
utslib.for	1102 Cardiorespiratory Medicine and Haematology	en_US
utslib.for	1107 Immunology	en_US
utslib.for	1116 Medical Physiology	en_US
utslib.for	06 Biological Sciences	en_US
utslib.for	11 Medical and Health Sciences	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Faculty of Science/School of Life Sciences
utslib.copyright.status	closed_access
pubs.issue	1	en_US
pubs.publication-status	Published	en_US
pubs.volume	113	en_US

Abstract:

Baseline ventilation heterogeneity is associated with airway hyperresponsiveness (AHR) in asthma; however, it is unknown whether increased baseline ventilation heterogeneity leads to AHR or both are independent effects of similar disease pathophysiology. Reducing functional residual capacity (FRC) in healthy subjects increases baseline ventilation heterogeneity and airway responsiveness, but the relationship between the two is unclear. The aim was to determine whether an increase in baseline ventilation heterogeneity due to a reduction in FRC correlated with the increase in response to methacholine. In 13 healthy male subjects, ventilation heterogeneity was measured by multiple-breath N2 washout before a cumulative high-dose (0.79-200 μmol) methacholine challenge. On a separate day, the protocol was performed with chest wall strapping (CWS) to reduce FRC. Indexes of ventilation heterogeneity in the convection-dependent (Scond) and diffusion-convection- dependent (Sacin) airways were calculated from the multiple-breath N2 washout. CWS decreased FRC by 15.6 ± 2.7% (P < 0.0001). CWS increased the percent fall in forced expiratory volume in 1 s during bronchial challenge (P = 0.006), and the magnitude of this effect was independently determined by the effect of CWS on Sacin and FRC (radj2 = 0.55, P = 0.02). This suggests that changes in baseline ventilation heterogeneity in healthy subjects are sufficient to increase airway responsiveness, independent of the presence of disease pathology. © 2012 the American Physiological Society.

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http://hdl.handle.net/10453/115286