Long-term efficacy of intensive cycle ergometer exercise training program for advanced COPD patients

Abstract

Background: Exercise training has been incorporated into the international guidelines for the treatment of chronic obstructive pulmonary disease (COPD). However, the long-term efficacy of the training program for patients with advanced COPD has never been evaluated in Thailand.

Purpose: To determine the long-term efficacy of intensive cycle ergometer exercise program on various clinical parameters of patients with advanced COPD.

Materials and methods: The patients with advanced COPD were separated into two groups: the intensive ergometer exercise program group and the control group. The clinical parameters of all the patients were assessed at baseline, every month for the first 3 months, and then every 3 months until they had completed the 24-month follow-up. Mann-Whitney U test was used to compare baseline mean differences between the groups. Repeated measure analysis was applied to determine the progress in all parameters during the entire follow-up period. Mean incase imputation method was applied to estimate the parameters of dropout cases.

Results: A total of 41 patients were enrolled: 27 in the intensive ergometer exercise program group and 14 in the control group. The intensive cycle ergometer exercise program group showed statistically significant improvements in muscle strength (from month 1 till the end of the study, month 24), endurance time (from month 1 till the end of measurement, month 12) and clinically significant improvements in 6-minute walk distance (from month 2 until month 9), dyspnea severity by transitional dyspnea index (from month 1 till the end of the study, month 24), and quality of life (from month 1 till the end of the study, month 24). There was no significant difference in survival rates between the groups.

Conclusion: The intensive ergometer exercise training program revealed meaningful long-term improvements in various clinical parameters for up to 2 years. These promising results should encourage health care professionals to promote exercise training for patients with advanced COPD who have limited daily activities despite optimal medication control.

Keywords: chronic obstructive pulmonary disease; ergometer training; physical endurance; pulmonary rehabilitation; strength training.

Figure 1

Flow-chart showing participation throughout the study. Abbreviations: Pre disc, prediscontinuation; SET, Suandok exercise training; mo, months; F/U, follow-up.

Figure 2

Change from baseline over 24 months in muscle strength. Notes: (A) Change from baseline over 24 months in upper limb muscle strength. (B) Change from baseline over 24 months in lower limb muscle strength. (C) Change from baseline over 24 months in respiratory muscle strength. Values and error bars represent the mean ± standard error. Within-group change from baseline; *P<0.05. Comparison between patients with SET and control groups; ^#P<0.05. Abbreviations: MIP, maximum inspiratory pressure; SET, Suandok exercise training.

Figure 2

Change from baseline over 24 months in muscle strength. Notes: (A) Change from baseline over 24 months in upper limb muscle strength. (B) Change from baseline over 24 months in lower limb muscle strength. (C) Change from baseline over 24 months in respiratory muscle strength. Values and error bars represent the mean ± standard error. Within-group change from baseline; *P<0.05. Comparison between patients with SET and control groups; ^#P<0.05. Abbreviations: MIP, maximum inspiratory pressure; SET, Suandok exercise training.

Figure 3

Change from baseline over 24 months in exercise capacities. Notes: (A) Change from baseline over 24 months in 6-MWD. (B) Change from baseline over 12 months in endurance time. Values and error bars represent the mean ± standard error. Within-group change from baseline in 6-MWD. Within-group change from baseline in endurance time; *P<0.05. Comparison between patients with SET and control groups; ^#P<0.05. Abbreviations: 6-MWD, 6-minute walk distance; SET, Suandok exercise training; MCID, minimal clinically important difference.

Figure 4

Effect on breathlessness. Notes: (A) Change from baseline over 24 months in mMRC score. (B) Change from baseline over 24 months in TDI score. Values and error bars represent the mean ± standard error. Within-group change from baseline in TDI; *MCID +1 unit. Comparison between patients with SET and control groups; ^#P<0.05. Abbreviations: mMRC, modified Medical Research Council; TDI, transitional dyspnea index; SET, Suandok exercise training; MCID, minimal clinically important difference; BDI, baseline dyspnea index.

Figure 5

Effect on HRQoL. Notes: Change from baseline over 24 months in SGRQ score. Values and error bars represent the mean ± standard error. Within-group change from baseline; *MCID −4 unit. Comparison between patients with SET and control groups; ^#P<0.05. Abbreviations: HRQoL, health-related quality of life; SGRQ, St George’s Respiratory Questionnaire; SET, Suandok exercise training; MCID, minimal clinically important difference.

Figure 6

Kaplan–Meier survival curves for patients in SET and control groups during 2 years of follow-up. Abbreviation: SET, Suandok exercise training.