The evidence of benefits of exercise training in interstitial lung disease: a randomised controlled trial

Our plain-English summary of The evidence of benefits of exercise training in interstitial lung disease: a randomised controlled trial, by L.M. Dowman, C.F. McDonald, C.J. Hill, et al (Thorax, 2017).

The study

• Authors: L.M. Dowman, C.F. McDonald, C.J. Hill, A.L. Lee, K. Barker, C. Boote, I. Glaspole, N.S.L. Goh, A.M. Southcott, A.T. Burge, R. Gillies, A. Martin, A.E. Holland
• Journal: Thorax
• Published: 2017;72(7):610-619
• Type of article: Randomized trial
• Cited by: 210 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Uncertainty exists regarding the clinical relevance of exercise training across the range of interstitial lung diseases (ILDs).

Objective: To establish the impact of exercise training in patients with ILDs of differing aetiology and severity.

Methods: 142 participants with ILD (61 idiopathic pulmonary fibrosis (IPF), 22 asbestosis, 23 connective tissue disease-related ILD (CTD-ILD) and 36 with other aetiologies) were randomised to either 8 weeks of supervised exercise training or usual care. Six-minute walk distance (6MWD), Chronic Respiratory Disease Questionnaire (CRDQ), St George Respiratory Questionnaire IPF-specific version (SGRQ-I) and modified Medical Research Council dyspnoea score were measured at baseline, 9 weeks and 6 months.

Measurements And Main Results: Exercise training significantly increased 6MWD (25 m, 95% CI 2 to 47 m) and health-related quality of life (CRDQ and SGRQ-I) in people with ILD. Larger improvements in 6MWD, CRDQ, SGRQ-I and dyspnoea occurred in asbestosis and IPF compared with CTD-ILD, but with few significant differences between subgroups. Benefits declined at 6 months except in CTD-ILD. Lower baseline 6MWD and worse baseline symptoms were associated with greater benefit in 6MWD and symptoms following training. Greater gains were seen in those whose exercise prescription was successfully progressed according to the protocol. At 6 months, sustained improvements in 6MWD and symptoms were associated with better baseline lung function and less pulmonary hypertension.

Conclusions: Exercise training is effective in patients across the range of ILDs, with clinically meaningful benefits in asbestosis and IPF. Successful exercise progression maximises improvements and sustained treatment effects favour those with milder disease.

Trial Registration Number: Results, ACTRN12611000416998.

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

In plain English

This was a randomised, assessor-blinded, controlled trial at three hospitals in Melbourne, Australia. Between November 2011 and June 2014, 142 people with interstitial lung disease were randomised: 61 with idiopathic pulmonary fibrosis (IPF), 22 with asbestosis, 23 with connective tissue disease-related interstitial lung disease and 36 with other diagnoses. The exercise group attended twice-weekly supervised aerobic and resistance training for 8 weeks. The usual-care group received weekly support phone calls. Across all participants, the exercise group walked a mean of 25 m further than usual care in a six-minute walk test at 9 weeks (95% CI 2 to 47 m), but this was not sustained at 6 months. The largest changes were in the asbestosis group: 68 m (10 to 124) at 9 weeks and 92 m (36 to 148) at 6 months compared with usual care. Differences in walk distance between disease subgroups were not statistically significant. No adverse events occurred during training. The authors concluded that exercise training is effective for people with interstitial lung disease. They noted the results might not apply to people with more advanced disease.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Multicentre randomised, assessor-blinded, controlled trial (exercise training versus usual care)
• Who was studied: 142 patients with interstitial lung disease at three tertiary hospitals in Melbourne, Australia, randomised between November 2011 and June 2014. Of these, 61 had IPF, 22 had dust-related ILD (all asbestosis), 23 had connective tissue disease-related ILD and 36 had other diagnoses. All 22 asbestosis participants were male (11 per arm).
• Exposure: The study did not examine asbestos exposure. The intervention was 8 weeks of twice-weekly supervised outpatient exercise training (30 min of aerobic cycling and walking, plus upper and lower limb resistance training) with a home exercise programme. The comparison group received usual care with weekly support telephone calls.
• Main results:
  • All ILD participants: six-minute walk distance improved with exercise training by a mean difference to control of 25 m (95% CI 2 to 47 m) at 9 weeks. The improvement was not sustained at 6 months (21 m, 95% CI −3 to 44 m).
  • Asbestosis subgroup (11 usual care, 11 exercise, intention to treat): the difference in six-minute walk distance between exercise and control was 68 m (95% CI 10 to 124) at 9 weeks and 92 m (95% CI 36 to 148) at 6 months. The comparable 9-week figures were 31 m (−5 to 66) for IPF and 3 m (−53 to 60) for connective tissue disease-related ILD.
  • The largest changes after the intervention were in the asbestosis group for six-minute walk distance. However, there was no significant difference between subgroups in walk distance.
  • Participants with asbestosis and with connective tissue disease-related ILD had significantly greater improvements in SGRQ-I symptom scores than those with IPF. For asbestosis, the 9-week difference was −19.8 (95% CI −37.3 to −3.4); lower scores mean improvement.
  • All ILD participants: perceived walking ability improved in 50% of the exercise group and 17% of the control group after the intervention period (p less than 0.001).
  • No adverse events occurred during exercise training.
  • Among participants whose exercise intensity was progressed according to the protocol, six-minute walk distance improved by 37 m (95% CI 11 to 64 m).
  • Lower baseline walk distance predicted greater short-term gain: for every 10 m increase in baseline six-minute walk distance, the gain at 9 weeks declined by 1.4 m. At 6 months, better physiological markers of disease severity predicted gains, with no effect of group allocation.
• The authors' conclusion: The authors concluded that exercise training is effective for people with interstitial lung disease and that this strengthens the case for recommending it as a standard treatment. They stated that improvements were larger in asbestosis than in IPF, with both groups obtaining clinically meaningful improvements.
• Limitations the authors state:
  • The 'other ILD' subgroup contained a diverse range of diagnoses, and sample sizes were too small for detailed analyses of these conditions.
  • Few participants needed long-term or exertional oxygen, so the results might not be generalisable to people with more advanced disease.
  • The authors did not assess whether the education component included in the intervention produced comparable or greater outcomes compared with exercise training alone.
  • The study may not have been optimally powered for the IPF subgroup.

Topics

Medical terms in this study, explained in our Lexicon: Interstitial Lung Disease, Idiopathic, Pulmonary Fibrosis, Six-Minute Walk Test, Quality of Life, Pulmonary Hypertension.

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