Immediate and One-Year Outcomes of an Asthma-Tailored Pulmonary Rehabilitation Programme in Overweight and Obese People with Difficult-to-Treat Asthma

Helen Clare Ricketts; Varun Sharma; Femke Steffensen; Elaine Mackay; Gordon Wallace MacDonald; Duncan S Buchan; Michael Lean; Rekha Chaudhuri; Douglas C Cowan

doi:10.2147/JAA.S466894

Immediate and One-Year Outcomes of an Asthma-Tailored Pulmonary Rehabilitation Programme in Overweight and Obese People with Difficult-to-Treat Asthma

J Asthma Allergy. 2024 Sep 25:17:911-928. doi: 10.2147/JAA.S466894. eCollection 2024.

Authors

Helen Clare Ricketts¹, Varun Sharma¹, Femke Steffensen², Elaine Mackay³, Gordon Wallace MacDonald⁴, Duncan S Buchan⁵, Michael Lean⁶, Rekha Chaudhuri⁷, Douglas C Cowan⁴

Affiliations

¹ College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
² Glasgow Clinical Research Facility, Glasgow Royal Infirmary, Glasgow, UK.
³ Pulmonary Rehabilitation Team, Glasgow Royal Infirmary, Glasgow, UK.
⁴ Respiratory Department, Glasgow Royal Infirmary, Glasgow, UK.
⁵ Division of Sports and Exercise, University of the West of Scotland, Glasgow, UK.
⁶ School of Medicine, Dentistry and Nursing, University of Glasgow, Glasgow, UK.
⁷ Respiratory Department, Gartnavel General Hospital, Glasgow, UK.

Abstract

Introduction: Management of difficult-to-treat asthma is particularly challenging in people with elevated body mass index (BMI). Our randomised controlled trial of pulmonary rehabilitation (PR) showed improved outcomes at 8 weeks. Here we assess immediate and one-year effects of asthma-tailored PR in participants with difficult-to-treat asthma and BMI ≥25 kg/m², and identify response predictors.

Methods: A prospective observational study of PR, tailored to asthma, comparing outcomes at baseline (V1), immediately after 8 weeks of PR (V2), and at 1 year (V3). Baseline characteristics were compared in responders/non-responders defined by achievement of minimum clinically important difference (MCID) for asthma control questionnaire (ACQ6) (0.5) at 8 weeks and 1 year.

Results: Of 92 participants, 56 attended V2 and 45 attended V3. Mean age was 60 (SD 13) years, 60% were female, and median (IQR) BMI was 33.8 (29.5-38.7) kg/m². At V1, V2, and V3, respectively, there were significant differences in ACQ6 (mean (95% CI): 2.5 (2.1-2.9), 2.2 (1.8-2.5), and 2.3 (1.9-2.7), p<0.003), Borg breathlessness score post-6-minute walk test (median (IQR): 2 (0.5-3), 1 (0-2), and 1 (0.5-2), p<0.035), and annualised exacerbations requiring prednisolone (median (IQR): 3 (2-5), 0 (0-4.7), and 1.5 (0-4.2), p<0.003). A total of 27/56 (48%) had improvements >MCID for ACQ6 at V2 and 16 (33%) at V3. Participants with higher ACQ6 scores at baseline (suggesting poorer asthma control) were more likely to achieve MCID. Baseline BMI, within the range studied, was not predictive.

Conclusion: Pulmonary rehabilitation induced improvements in asthma-related outcomes including perception of breathlessness, asthma control, and exacerbation frequency at 1 year. Those with poorer baseline asthma control were more likely to benefit.

Keywords: asthma; difficult-to-treat asthma; obesity; pulmonary rehabilitation.

Grants and funding

This work was funded by a NHS Greater Glasgow & Clyde Endowment Fund - CG0435 North Glasgow Lung Research. The endowment fund holder is the corresponding author who designed the study, and has responsibility for collection, analysis and interpretation of some data, as well as substantive revision of the writing.