Exercise training for asbestos-related and other dust-related respiratory diseases: a randomised controlled trial

Our plain-English summary of Exercise training for asbestos-related and other dust-related respiratory diseases: a randomised controlled trial, by M.T. Dale, Z.J. McKeough, P.A. Munoz, et al (BMC Pulmonary Medicine, 2014).

The study

• Authors: M.T. Dale, Z.J. McKeough, P.A. Munoz, P. Corte, P.T. Bye, J.A. Alison
• Journal: BMC Pulmonary Medicine
• Published: 2014;14:180
• Type of article: Randomized trial
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: The study aimed to determine the short and long-term effects of exercise training on exercise capacity and health-related quality of life (HRQoL) compared to usual care in people with dust-related pleural and interstitial respiratory diseases. No previous studies have specifically evaluated exercise training in this patient population.

Methods: Participants with a diagnosis of a dust-related respiratory disease including asbestosis and asbestos related pleural disease were recruited and randomised to an eight-week exercise training group (EG) or a control group (CG) of usual care. Six-minute walk distance (6MWD), St George's Respiratory Questionnaire (SGRQ) and Chronic Respiratory Disease Questionnaire (CRQ) were measured at baseline, eight weeks and 26 weeks by an assessor blinded to group allocation.

Results: Thirty-three of 35 male participants completed the study. Sixty-nine percent of participants had asbestos related pleural disease. At eight weeks, compared to the CG, the EG showed a significantly increased 6MWD (mean difference (95%CI)) 53 metres (32 to 74), improved SGRQ total score, -7 points (-13 to -1) and increased CRQ total score, 6.4 points (2.1 to 10.7). At 26 weeks significant between-group differences were maintained in 6MWD, 45 metres (17 to 73) and CRQ total score, 13.1 points (5.2 to 20.9).

Conclusion: Exercise training improved short and long-term exercise capacity and HRQoL in people with dust-related pleural and interstitial respiratory diseases.

Clinical Trial Registration Number: ANZCTR12608000147381. Date trial registered: 27.03.2008.

In plain English

This randomised controlled trial in New South Wales, Australia (2009 to 2011) tested an eight-week exercise programme for people with non-malignant dust-related lung and pleural disease. Thirty-five men took part. Twenty-four had asbestos related pleural disease; the others had asbestosis, silicosis, both asbestosis and pleural disease, or mixed-dust pneumoconiosis. People with mesothelioma or with pleural plaques only were excluded. Eighteen men were assigned to supervised walking and cycling training three times a week, and 15 of them attended at least 80% of sessions; 17 continued usual care. After eight weeks, allowing for starting distances, the exercise group's six-minute walk distance was 53 metres greater than the control group's (95% CI 32 to 74). It also scored better on two quality-of-life questionnaires. At 26 weeks, the walking difference (45 metres, 95% CI 17 to 73) and one questionnaire's difference remained. The other questionnaire no longer showed a significant difference. Gains in daily physical activity were small. No adverse events were reported during the exercise training. The authors concluded that exercise training improved short and long-term exercise capacity and quality of life. They noted that only men took part, none had severe disease, and diagnoses were mixed.

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: Multi-centred, assessor-blinded, parallel-group randomised controlled trial comparing exercise training with usual care
• Who was studied: 35 men with non-malignant dust-related pleural or interstitial respiratory disease, recruited in New South Wales, Australia, between January 2009 and July 2011 (44 were assessed). Diagnoses were: 24 (69%) asbestos related pleural disease (diffuse pleural thickening and/or rounded atelectasis), 5 asbestosis, 3 silicosis, 2 combined asbestos related pleural disease and asbestosis, and 1 mixed-dust pneumoconiosis. 18 were in the exercise group and 17 in the control group, with a mean age of 71 years. People with mesothelioma or with discrete parietal pleural plaques as their only sign of exposure were excluded.
• Exposure: The factor studied was the intervention, not dust exposure. The exercise group did individually prescribed, supervised aerobic walking and cycling training at one of seven pulmonary rehabilitation programmes, three times weekly for eight weeks, with no strength training and no education component. The control group continued usual medical care. Dust exposure (fiber type, jobs, dose) was not measured or described.
• Main results:
  • 33 of the 35 male participants completed the study.
  • In the exercise group, 15 of 18 participants were adherent with the training, defined as attending at least 80% of sessions. Three were non-adherent and attended 3, 9 and 17 sessions.
  • At eight weeks, the between-group difference in six-minute walk distance from the analysis adjusting for baseline was 53 metres (95% CI 32 to 74), in favour of the exercise group. The observed mean distances at eight weeks were 548 metres in the exercise group and 489 metres in the control group.
  • At 26 weeks, the between-group difference in change in six-minute walk distance from baseline was 45 metres (95% CI 17 to 73, p = 0.003), in favour of the exercise group.
  • At eight weeks, the exercise group improved on the St George's Respiratory Questionnaire total score compared with the control group: -7 points (95% CI -13 to -1). Lower scores mean better quality of life.
  • At 26 weeks, there were no significant differences between groups on the St George's Respiratory Questionnaire. The total score difference was -4 (95% CI -12 to 4, p = 0.293).
  • The Chronic Respiratory Disease Questionnaire total score was higher in the exercise group than in the control group by 6.4 points (95% CI 2.1 to 10.7) at eight weeks and by 13.1 points (95% CI 5.2 to 20.9) at 26 weeks.
  • At eight weeks, the exercise group improved endurance cycle time by a mean of 222 seconds compared with the control group (95% CI 84 to 360).
  • At eight weeks, the exercise group improved peak work rate by a mean of 12 watts compared with the control group (95% CI 5 to 19).
  • At eight weeks, the exercise group showed small, statistically significant improvements compared with the control group in average daily steps (1514, 95% CI 15 to 3012) and average daily METs (0.08, 95% CI 0.01 to 0.15).
  • At 26 weeks, the difference in average daily METs was 0.11 (95% CI 0.03 to 0.20, p = 0.012), which the authors called very small. The difference in average daily steps was not significant (1206, 95% CI -156 to 2568, p = 0.08).
  • No adverse events were reported during the exercise training.
• The authors' conclusion: The authors concluded that exercise training improved short and long-term exercise capacity and health-related quality of life in people with dust-related pleural and interstitial respiratory diseases.
• Limitations the authors state:
  • The cycle tests were not repeated at 26 weeks, so it is unknown whether the gains in peak and endurance exercise capacity lasted.
  • The programme did not include resistance training, so its effects in this population remain unclear.
  • Only men volunteered, so the findings cannot be extended to women.
  • No participants had severe disease or were on long-term oxygen therapy, so the findings cannot be extended to those groups.
  • The participants had a mix of diagnoses, which limits how far the findings can be generalised.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Quality of Life, Interstitial, Six-Minute Walk Test.

Related studies

• Exercise training to improve exercise capacity and quality of life in people with non-malignant dust-related respiratory diseases — M.T. Dale, Z.J. McKeough, et al. (2015)
• The evidence of benefits of exercise training in interstitial lung disease: a randomised controlled trial — L.M. Dowman, C.F. McDonald, et al. (2017)
• Physical activity in people with asbestos related pleural disease and dust-related interstitial lung disease: An observational study — M.T. Dale, Z.J. McKeough, et al. (2015)
• Functional exercise capacity and health-related quality of life in people with asbestos related pleural disease: an observational study — M.T. Dale, Z.J. McKeough, et al. (2013)
• Spiroergometric parameters at maximal exercise testing assessed functional respiratory impairment in asbestos-induced fibrosis — J. Schneider, R. Arhelger, et al. (2014)
• Factors influencing exercise performance in thoracic cancer — R. England, M. Maddocks, et al. (2012)

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