Objective cough frequency, airway inflammation, and disease control in asthma

Marsden, P. A., Satia, I., Ibrahim, B., Woodcock, A., Yates, L., Donnelly, I., Jolly, L., Thomson, N., Fowler, S. J. and Smith, J. A. (2016) Objective cough frequency, airway inflammation, and disease control in asthma. Chest, 149(6), pp. 1460-1466. (doi: 10.1016/j.chest.2016.02.676) (PMID:26973014)

[img]
Preview
Text
120652.pdf - Accepted Version

359kB

Abstract

Background Cough is recognized as an important troublesome symptom in the diagnosis and monitoring of asthma. Asthma control is thought to be determined by the degree of airway inflammation and hyperresponsiveness but how these factors relate to cough frequency is unclear. The goal of this study was to investigate the relationships between objective cough frequency, disease control, airflow obstruction, and airway inflammation in asthma. Methods Participants with asthma underwent 24-h ambulatory cough monitoring and assessment of exhaled nitric oxide, spirometry, methacholine challenge, and sputum induction (cell counts and inflammatory mediator levels). Asthma control was assessed by using the Global Initiative for Asthma (GINA) classification and the Asthma Control Questionnaire (ACQ). The number of cough sounds was manually counted and expressed as coughs per hour (c/h). Results Eighty-nine subjects with asthma (mean ± SD age, 57 ± 12 years; 57% female) were recruited. According to GINA criteria, 18 (20.2%) patients were classified as controlled, 39 (43.8%) partly controlled, and 32 (36%) uncontrolled; the median ACQ score was 1 (range, 0.0-4.4). The 6-item ACQ correlated with 24-h cough frequency (r = 0.40; P < .001), and patients with uncontrolled asthma (per GINA criteria) had higher median 24-h cough frequency (4.2 c/h; range, 0.3-27.6) compared with partially controlled asthma (1.8 c/h; range, 0.2-25.3; P = .01) and controlled asthma (1.7 c/h; range, 0.3-6.7; P = .002). Measures of airway inflammation were not significantly different between GINA categories and were not correlated with ACQ. In multivariate analyses, increasing cough frequency and worsening FEV1 independently predicted measures of asthma control. Conclusions Ambulatory cough frequency monitoring provides an objective assessment of asthma symptoms that correlates with standard measures of asthma control but not airflow obstruction or airway inflammation. Moreover, cough frequency and airflow obstruction represent independent dimensions of asthma control.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Thomson, Professor Neil and Jolly, Miss Lisa and Donnelly, Mrs Iona
Authors: Marsden, P. A., Satia, I., Ibrahim, B., Woodcock, A., Yates, L., Donnelly, I., Jolly, L., Thomson, N., Fowler, S. J., and Smith, J. A.
College/School:College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:Chest
Publisher:Elsevier
ISSN:0012-3692
ISSN (Online):1931-3543
Published Online:10 March 2016
Copyright Holders:Copyright © 2016 Elsevier
First Published:First published in Chest 149(6):1460-1466
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

University Staff: Request a correction | Enlighten Editors: Update this record