Aerobic exercise training improves autonomic nervous control in patients with COPD.
OBJECTIVE
Autonomic modulation is adversely impacted in patients with chronic obstructive pulmonary disease (COPD). The purpose of the present investigation is to assess the effects of a 6-week aerobic exercise training program on autonomic modulation of heart rate in patients with COPD.


METHODS
Forty patients of both sexes with moderate-to-severe COPD were randomly allocated to aerobic exercise training (PT, n=20) or to usual care (Control, n=20). The training program consisted of lower and upper limb stretching and 30 min of treadmill exercise, 3 times per week for a 6-week period. Physiological data during symptom-limited exercise testing and the six-minute walk test (6MWT) were assessed. In addition, R-R intervals were obtained at rest and during the 6MWT. Heart rate variability was analyzed by time (rMSSD and SDNN index) and frequency domains (high frequency--HF, low frequency--LF and HF/LF ratio).


RESULTS
Peak oxygen consumption significantly improved in the training group only (p<0.05). Moreover, the training group demonstrated significant improvements (p<0.05) in blood lactate, minute ventilation, dyspnea at peak exercise, sympathetic activity, and parasympathetic activity at rest and during submaximal exercise. Lastly, a positive and significant correlation was found between change in 6MWT distance and rMSSD index (r=0.65 and p=0.001).


CONCLUSIONS
Neural control of heart rate, in addition to other clinically valuable measures, is positively altered in moderate-severe COPD patients following 6 weeks of aerobic exercise training. The improvement in submaximal performance after exercise training was associated with parasympathetic activity.
Borghi-Silva
Audrey
A
Cardiopulmonary Physiotherapy Laboratory, Nucleus of Research in Physical Exercise, Department of Physiotherapy, Federal University of Sao Carlos, UFSCar, Rodovia Washington Luis, KM 235, Monjolinho, CEP: 13565-905 Sao Carlos, SP, Brazil. audrey@ufscar.br
Arena
Ross
R
Castello
Viviane
V
Simões
Rodrigo Polaquini
RP
Martins
Luis Eduardo Barreto
LE
Catai
Aparecida Maria
AM
Costa
Dirceu
D
D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D005081:Exercise Therapy; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D015397:Program Evaluation; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000534:rehabilitation; D016896:Treatment Outcome