Potential effect of 6 versus 12-weeks of physical training on cardiac autonomic function and exercise capacity in chronic obstructive pulmonary disease.
Eur J Phys Rehabil Med 2015;
51:211-221. [PMID:
24594853]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND
Exercise is an important part of chronic obstructive pulmonary disease (COPD) treatment. However, it is not know about the minimum effective time of physical training that could beneficially modify the cardiac autonomic modulation (CAM) and exercise capacity in these patients.
AIM
To contrast the potential effects of a physical training program (PTP), for 6 versus 12 weeks, on CAM by linear and nonlinear heart rate variability (HRV) indices and exercise capacity in COPD patients.
DESIGN
Prospective randomized controlled trial.
SETTING
Outpatient pulmonary rehabilitation.
POPULATION
Twenty moderate-to-severe COPD patients were randomly assigned to either a training group (N.=10) or a control group (N.=10).
METHODS
HRV at rest and during submaximal test was determined by linear (rMSSD and SDNN) and non-linear indices (SD1, SD2 and sample entropy [SE]). In addition, key responses were obtained during cardiopulmonary exercise testing (CPET), the walking distance (WD) during the six minute walking test and submaximal constant speed testing (CST). PTP consisted of 30 minutes of aerobic exercise training on a treadmill, 3 times per week at 70% of CPET peak speed rate. Patients were evaluated on baseline, 6 and 12 weeks.
RESULTS
Significant improvements in HRV indices, WD, as well as, other physiological responses were observed after 6 weeks of the PTP and maintained until 12 weeks (P<0.05). However, after 12 weeks, the SD1 index demonstrated an additional improvement compared with 6 weeks (P<0.05). Peak oxygen uptake and dioxide carbon production improved only after 12 weeks (P<0.05). Interestingly, the 6th week-baseline delta (6th week-baseline) of WD, SDNN and SE were significantly higher than 12th week-6th week delta (P<0.05).
CONCLUSION
These results indicate that beneficial changes on cardiac autonomic modulation in conjunction with improvement in submaximal functional capacity occur in the first 6 weeks of PTP in moderate to severe COPD.
CLINICAL REHABILITATION IMPACT
Short-term rehabilitation (6 weeks) is an effective sufficient time to beneficially modify important outcomes as cardiac modulation and exercise capacity in COPD patients.
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