Back to Journals » Journal of Asthma and Allergy » Volume 6

Effects of two inhaled corticosteroid/long-acting beta-agonist combinations on small-airway dysfunction in mild asthmatics measured by impulse oscillometry

Authors Diong B, Singh K, Menendez R

Received 22 May 2013

Accepted for publication 2 July 2013

Published 5 August 2013 Volume 2013:6 Pages 109—116


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 3

Bill Diong,1 Kshitiz Singh,2 Rogelio Menendez3

1School of Engineering, Southern Polytechnic State University, Marietta, GA, USA; 2College of Science and Engineering, Texas Christian University, Fort Worth, TX, USA; 3Allergy and Asthma Research Center of El Paso, El Paso, TX, USA

Background: We previously showed that the long-acting beta agonist (LABA) salmeterol as inhalation powder or metered-dose inhaler improves lung-function parameters assessed by impulse oscillometry (IOS) in 2- to 5-year-old children with reversible-airway disease within 15 minutes.
Objective: We studied 12- to 45-year-olds with mild persistent asthma in order to compare the onset and extent of peripheral airway effects following the first dose and after 4 weeks dosing with two inhaled corticosteroid (ICS)/LABA combinations: fluticasone propionate/salmeterol 115/21 and budesonide/formoterol 160/4.5.
Methods: Thirty subjects with mild persistent asthma using only an as-needed short-acting beta-agonist (albuterol) who had at least a 40% change in integrated low-frequency reactance postalbuterol were selected and randomized to receive either fluticasone propionate/salmeterol or budesonide/formoterol (15 subjects each). We collected three to six IOS replicates at baseline, at 5, 20, 40, 60, 120, and 240 minutes postdose at randomization, and after 4 weeks of twice-daily dosing. Blinded investigators calculated IOS frequency-dependent resistance and reactance (R5–R20 and AX), indicative of small-airway dysfunction, and also estimated the peripheral airway resistance (Rp) and peripheral airway compliance (Cp), using a respiratory-impedance model.
Results: At randomization visits, onset of action was detected as early as 5 minutes (t-test, P < 0.05) after fluticasone propionate/salmeterol by Cp, and within 5 minutes after budesonide/formoterol by R5–R20, AX, Rp, and Cp. However, after 4 weeks of dosing, only Rp was significantly different (from 60 to 120 minutes) after fluticasone propionate/salmeterol, while R5–R20, AX, Rp, and Cp were not significantly different within 240 minutes after budesonide/formoterol.
Conclusion: These two ICS/LABA combinations initially improved the peripheral airway function of 12- to 45-year-old asthmatics significantly in about 5 minutes or less, as measured by R5–R20, AX, Rp, and/or Cp. After regular dosing for 4 weeks, pre- to postdose differences in these parameters had diminished significantly due to improved predose status of peripheral airways. Single dosing with ICS/LABA combinations in mild persistent asthma improves small-airway function, and the effect is maintained over a 12-hour interval by regular use for 4 weeks.

Keywords: asthma, ICS/LABA combination, impulse oscillometry parameters, lung-model parameters, peripheral airway resistance, peripheral airway compliance

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]