Abstract
Respiratory symptoms, including cough, are prevalent in individuals with asthma when exercising. This study investigates whether a heat and moisture exchanger (HME) face mask is effective in modulating exercise-induced bronchoconstriction (EIB) and post-exercise cough in a cold, dry environment in individuals with asthma.
Twenty-six participants diagnosed with asthma (20 males, 6 females) completed three cycling exercise challenges at 8°C and 24% relative humidity in a randomised order. Participants wore either an HME mask (MASK), sham mask (SHAM), or no mask (CONT). Following a 3-min warm-up, participants completed 6-min cycling at 80% peak power output. Before and after exercise, maximal flow-volume loops were recorded. Post-exercise cough was monitored with a Leicester Cough Monitor (LCM) for 24 h. Results were analysed using repeated-measures ANOVA and Friedman's tests and data were presented as the mean±sd or median (interquartile range (IQR)).
Eleven participants failed to demonstrate EIB (i.e. >10% fall in forced expiratory volume in 1 s after exercise) and were removed from analysis. The percentage fall in forced expiratory volume in 1 s following exercise in CONT was greater than MASK (MASK: −6% (7%), SHAM: −11% (11%), CONT: −13% (9%); p<0.01). No difference was found between exercise in cough count per hour over the 24-h monitoring period or the number of coughs in the first hour after exercise.
HME masks can attenuate EIB when exercising in cold, dry environments. The SHAM mask may not have been entirely inert, demonstrating the challenges of running randomised control trials utilising control and sham conditions.
Abstract
Heat and moisture exchanger masks can reduce bronchoconstriction in individuals with exercise-induced bronchoconstriction when exercising in cold, dry environments https://bit.ly/2JKeLnX
Footnotes
Data available from the Dryad Digital Repository: https://doi.org/10.5061/dryad.gf1vhhmkm.
ClinicalTrials.gov identifier: NCT04302610.
This article has been republished to correct the presentation of an author name.
Conflict of interest: A.R. Jackson has nothing to disclose.
Conflict of interest: J.H. Hull has nothing to disclose.
Conflict of interest: J.G. Hopker has nothing to disclose.
Conflict of interest: H. Fletcher has nothing to disclose.
Conflict of interest: W. Gowers has nothing to disclose.
Conflict of interest: S.S. Birring reports grants and personal fees from Merck, and personal fees from Bayer, NeRRe and Sanofi, outside the submitted work.
Conflict of interest: J.W. Dickinson has nothing to disclose.
Support statement: This study was funded by AsthmaUK. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received October 1, 2019.
- Accepted March 31, 2020.
- Copyright ©ERS 2020
This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial Licence 4.0.