Can Outpatient Pulmonary Rehabilitation Program Change the Quality of Muscle in Patients with Chronic Obstructive Pulmonary Disease?

̶ A Randomized Controlled Crossover Study ̶

抄録

[Background/Purpose]

In this study, we attempted to determine whether an outpatient pulmonary rehabilitation program can change the muscle quality in patients with chronic obstructive pulmonary disease (COPD).

[Methods]

Twelve outpatients with COPD were randomized to either the intervention (INT) or the control (CON) group with a 1-week washout period between the groups. The INT group participants completed an 8-week program involving a weekly outpatient pulmonary rehabilitation program. The INT group performed 4 resistance-training sessions, with the load on the modified Borg scale being 4 ‒ 7 per set. The set or the number of repetitions was increased or the rest time between consecutive sets was decreased every week. The subjects were also instructed in self-training. The CON group maintained their routine lifestyle. The evaluations were performed once at baseline and then after the intervention. The primary outcomes were assessed by measuring the quadriceps muscle echo intensity (EI) using ultrasonography. The ultrasonography images were recorded using a personal computer and analyzed. An unpaired t-test was used to compare the results of the INT and CON groups.

[Results]

There were no baseline differences between the groups. After 8 weeks, the EI of the INT group was significantly lower than that of the CON group (p < 0.05). The INT group showed significant improvements in the EI (p < 0.05).

[Discussion/Conclusion] This study demonstrated that 8-week outpatient pulmonary rehabilitation program involving weekly sessions improved the quadriceps muscle EI in COPD patients. The lower EI of quadriceps indicates that the muscle cell gap had little connective tissue, less fat, and lower extracellular fluid, associated with muscle strength and physical activity. Our study indicates that a pulmonary rehabilitation program could help improve the quadriceps muscle quality in COPD patients.

 

[Ethical consideration]

The study was approved by the regional ethics committee and conducted in accordance with the Declaration of Helsinki.