Edited by: Douglas Robinson
Less small airway dysfunction in asymptomatic bronchial hyperresponsiveness than in asthma
Article first published online: 12 OCT 2013
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Volume 68, Issue 11, pages 1419–1426, November 2013
How to Cite
Less small airway dysfunction in asymptomatic bronchial hyperresponsiveness than in asthma. Allergy 2013; 68: 1419–1426., , , , , , , .
- Issue published online: 30 OCT 2013
- Article first published online: 12 OCT 2013
- Manuscript Accepted: 20 JUL 2013
- asymptomatic bronchial hyperresponsiveness;
- small airways
Bronchial hyperresponsiveness (BHR) can be present in subjects without any respiratory symptoms. Little is known about the role of the small airways in asymptomatic subjects with BHR.
We investigated small airway function assessed by spirometry and impulse oscillometry, as well as Borg dyspnea scores at baseline and during a methacholine provocation test in 15 subjects with asymptomatic BHR, 15 asthma patients, and 15 healthy controls.
At baseline, small airway function (R5–R20 and X5) was comparable between subjects with asymptomatic BHR and healthy controls, whereas asthma patients showed small airway dysfunction as reflected by higher R5–R20 and lower X5 values. During methacholine provocation, small airway dysfunction was more severe in asthma patients than in subjects with asymptomatic BHR. Interestingly, a higher increase in small airway dysfunction during methacholine provocation was associated with a higher increase in Borg dyspnea scores in subjects with asymptomatic BHR, but not in asthma patients.
Subjects with asymptomatic BHR may experience fewer symptoms in daily life because they have less small airway dysfunction.