Exercise as it relates to Disease/Walking: A step in the right direction for COPD patients

Ground Based Walking

This review was completed for The University of Canberra under the unit Health Disease and exercise and considers the relationship between exercise and increased quality of life in COPD patients. [1]

The Paper: Wootton, S.L., et al., Ground-based walking training improves quality of life and exercise capacity in COPD. Eur Respir J, 2014. 44(4): p. 885-94.

What is the background to the research

COPD is defined as a progressive limitation of airflow into the lungs over a period of time that is essentially irreversible. [2, 3] [4] There are certain risk factors associated with COPD including cigarette smoke, age, environmental exposures and pollutants that increase COPD prevalence [2] [5] [4]. The gold standard for classifying the disease severity is the global initiative for chronic obstructive lung disease (GOLD) [1]. This is based on the patients symptoms, exacerbation history and a spirometry assessment measuring airflow obstruction. [1] [3]It is considered that an increase in COPD exacerbation frequency is indicative of higher disease severities. [6]

Healthy Lungs Vs COPD

Chronic obstructive pulmonary disease (COPD) is impacting society on a global scale with predictions that in 2020 it will be the third leading cause of death for populations over 45 years old. [7] [4] The cost on health care is substantial with an estimate reportedly spending over 42 billion per annum. [7] However, COPD also imposes significant costs to the quality of life of the people living with the disease everyday [5]. There is a specific need to optimise treatments associated with COPD in the present as the the global burden of this respiratory disease is set to rapidly increase in the future. [5] [6] [3, 4] This current study uncovers the relationship between ground based walking training and improvements in the quality of life for the people living with COPD. [1]

Where is the research from?

Recruitment for this study included participants from both Perth and Sydney from pulmonary rehab outpatient referrals. This particular trial was registered prior to commencement by the Australia and New Zealand clinical trials registry [1].

This study additionally gained approval from multiple ethics committees as listed below,

• Sydney South West Area Health Service
• The university of Sydney
• Curtin University
• Sir Charles Gairdner Hospital
• Bentley hospital

What kind of research was this?

This study was a prospective, blinded multicenter, randomised control trial involving concealed allocation [1]. Given that randomised controls are the gold standard for research this study is both valid and reliable. The researchers however, did bias randomisation towards the walking group with a 2:1 ratio compared to controls given the strong hypothesis this study encompassed and the requirement for follow up results for legitimacy.

What did the research involve?

The research was gathered from a group of participants with moderate, severe and very severe COPD, as classified according to the global initiative for chronic obstructive lung disease spirometry. Randomisation occurred through an independent telephone service, dividing participants into either the walking group or control group. The walking groups intervention involved ground based walking on a flat indoor track with supervision from an experienced pulmonary rehabilitation physiotherapist. Ideally the intervention participants attended training sessions three times weekly for eight weeks, with training gradually progressing from 30 to 40 minutes’ duration. In this group, the patients were required to walk at a pace which produced a dyspnoea or shortness of breath score of 3-4, or more functionally, a pace where the patient could hold a conversation however not sing. (EVIDENCE) If the patient was unable to increase step length and thus speed, the addition of weights were added to increase exercise expenditure. Although rest breaks were allowed when symptoms became intolerable, this was not incorporated in the total walking training time. It was the individuals exercise tolerance and ability of which guided any increases in speed or intensity which was different for every participant. The control group however, had no exercise information provided and instead consisted of a letter which was sent to the patients GP discussing the patient’s involvement in the study regarding the intention to treat using usual medical care.

The limitations associated with this study included the lack of physiological insight and accompanied testing. It is not known what the improvements in exercise endurance or reduction of dyspnoea was specifically caused from with decreased ventilator demand, decreased anxiety or improved neuromuscular recruitment all plausible conclusions. Furthermore as this research paper excluded people with mild COPD, the idea of ground based walking as a global treatment cannot be extended to the entire COPD community and further research and test will need to be undertaken.

What were the basic results?

The results from this study were constructed from the outcome measure findings employed. The primary outcome measure, health related quality of life (HRQoL) was assessed via two questionnaires’. The Saint George Respiratory Questionnaire (SGRQ) considered symptoms, activity limitations and the impact of respiratory disease, while the Chronic Respiratory Questionnaire (CRQ) is specific to COPD and considers dyspnoea, fatigue and emotional function. The results comparing bassline and post intervention outcomes reveal significant improvements in all domains of both the SGRQ and CRQ for the walking group compared to controls. Additionally, the second aim of the study was to determine if there were any improvements in endurance, functional and peak exercise capacity with ground based walking. The outcome measures included the 6 minute walk test (6MWT), Endurance shuttle walk test (ESWT) and incremental shuttle walk test (ISWT). Compared to controls, the walking group had significant improvements in the 6MWT distance and ISWT time. Furthermore, at the conclusion of the study 18% of patients in the walking group compared to only 4% of patients in the control group completed 20 minutes on the ESWT.

The researchers reiterate the outcome measure findings in multiple sections throughout the paper as well as delving into why they may have acquired the results they produced. For the primary outcome measures it is discussed that the SGRQ may have generated more favorable results given the questionnaire itself focus on walking related activity. In relation to the secondary outcome measure findings, although there were significant improvements for walking endurance in the ESWT, preferable results for exercise capacity measured with the 6 minute walk distance covered (6MWD) is minimal. It is thought that the cause of improved results may be more related to the small reduction in the in the control group distance post intervention, rather than any improvements in the walking group.

What conclusions can we take from this research?

The conclusions gained from this randomised control trial is that ground based walking improves quality of life for people living with COPD. [1, 8] It is indicated from the intervention that while people are not able to walk faster, they are able to walk further with ground based walking training. This new found endurance is thus the critical factor for completion of activities of daily living and as a result improving health related quality of life. The findings of this study also parallel with other publications which report that exercise is the keystone of pulmonary rehabilitation [8] with the reduction of daily symptoms including fatigue and dyspnoea.

Practical advice

Ground based walking training for people living with moderate to severe COPD is an appropriate and resource efficient approach to improving HRQoL through walking endurance. Ground based walking provides an alternative to resource based pulmonary rehabilitation programs which involve equipment such as treadmills or cycle ergometers. Instead it offers a more simplistic, equipment free and easy to administer approach more suitable to remote areas. There were also no adverse effects reported throughout the study despite the severity of COPD the patients had as well as the long training sessions up to 45 mins long, thus reflecting the opportunities for this modality to incorporated safely in the wider community.

Further information/resources

Further readings regarding COPD and the possible benefits associated with physical activity can be found in the below links.

• http://lungfoundation.com.au/patient-support/copd/
• 1800 654 301 - Information and Patient Support Lung Foundation
• https://www.dailystrength.org/group/copd-emphysema

References

1. Wootton, S.L., et al., Ground-based walking training improves quality of life and exercise capacity in COPD. Eur Respir J, 2014. 44(4): p. 885-94. 2. Siafakas, N.M., et al., Optimal assessment and management of chronic obstructive pulmonary disease (COPD). The European Respiratory Society Task Force. Eur Respir J, 1995. 8(8): p. 1398-420. 3. Ahmed-Sarwar, N., D.P. Pierce, and D.C. Holub, COPD: Optimizing treatment. J Fam Pract, 2015. 64(10): p. 610-23. 4. Mannino, D.M. and A.S. Buist, Global burden of COPD: risk factors, prevalence, and future trends. Lancet, 2007. 370(9589): p. 765-73. 5. Halbert, R.J., et al., Global burden of COPD: systematic review and meta-analysis. Eur Respir J, 2006. 28(3): p. 523-32. 6. Donaldson, G.C. and J.A. Wedzicha, COPD exacerbations .1: Epidemiology. Thorax, 2006. 61(2): p. 164-8. 7. Blair, K.A. and A.J. Evelo, Risk factors for COPD: what do NPs know? J Am Assoc Nurse Pract, 2014. 26(3): p. 123-30. 8. Spruit, M.A., et al., COPD and exercise: does it make a difference? Breathe (Sheff), 2016. 12(2): p. e38-49.