title: Effect of pulmonary rehabilitation on peripheral muscle fiber remodeling in patients with COPD in GOLD stages II to IV.
abstract: BACKGROUND
  In most patients with COPD, rehabilitative exercise training partially reverses the morphologic and structural abnormalities of peripheral muscle fibers. However, whether the degree of improvement in muscle fiber morphology and typology with exercise training varies depending on disease severity remains unknown.
  
  
  METHODS
  Forty-six clinically stable patients with COPD classified by GOLD (Global Initiative for Obstructive Lung Disease) as stage II (n = 14), III (n = 18), and IV (n = 14) completed a 10-week comprehensive pulmonary rehabilitation program consisting of high-intensity exercise three times weekly.
  
  
  RESULTS
  At baseline, muscle fiber mean cross-sectional area and capillary density did not significantly differ between patients with COPD and healthy control subjects, whereas muscle fiber type I and II proportion was respectively lower (P < .001) and higher (P < .002) in patients with GOLD stage IV compared with healthy subjects and patients with GOLD stages II and III. Exercise training improved, to a comparable degree, functional capacity and the St. George Respiratory Questionnaire health-related quality of life score across all three GOLD stages. Vastus lateralis muscle fiber mean cross-sectional area was increased (P < .001) in all patient groups (stage II: from 4,507 ± 280 μm² to 5,091 ± 271 μm² [14% ± 3%]; stage III: from 3,753 ± 258 μm² to 4,212 ± 268 μm² [14% ± 3%]; stage IV: from 3,961 ± 266 μm² to 4,551 ± 262 μm² [17% ± 5%]), whereas all groups exhibited a comparable reduction (P < .001) in type IIb fiber proportion (stage II: by 6% ± 2%; stage III: by 6% ± 1%; stage IV: by 7% ± 1%) and an increase (P < .001) in capillary to fiber ratio (stage II: from 1.48 ± 0.10 to 1.81 ± 0.10 [23% ± 5%]; stage III: from 1.29 ± 0.06 to 1.56 ± 0.09 [21% ± 5%]; stage IV: from 1.43 ± 0.10 to 1.71 ± 0.13 [18 ± 3%]). The magnitude of changes in the aforementioned variables did not differ across GOLD stages.
  
  
  CONCLUSIONS
  Functional capacity and morphologic and typologic adaptations to rehabilitation in peripheral muscle fibers were similar across GOLD stages II to IV. Pulmonary rehabilitation should be implemented in patients at all COPD stages.
authors.affiliation: Department of Critical Care Medicine, Pulmonary Rehabilitation Center, Evangelismos Hospital, Athens, Greece; Department of Physical Education and Sport Sciences, Athens, Greece. Electronic address: gianvog@phed.uoa.gr.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vogiatzis
authors.affiliation: Department of Physical Education and Sport Sciences, Athens, Greece; 1st Department of Neurology, Aeginition Hospital, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Terzis
authors.affiliation: Department of Critical Care Medicine, Pulmonary Rehabilitation Center, Evangelismos Hospital, Athens, Greece.
authors.forename: Grigoris
authors.initials: G
authors.lastname: Stratakos
authors.affiliation: Department of Physical Education and Sport Sciences, Athens, Greece.
authors.forename: Evgenia
authors.initials: E
authors.lastname: Cherouveim
authors.affiliation: Department of Critical Care Medicine, Pulmonary Rehabilitation Center, Evangelismos Hospital, Athens, Greece; Department of Physical Education and Sport Sciences, Athens, Greece.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Athanasopoulos
authors.affiliation: Department of Critical Care Medicine, Pulmonary Rehabilitation Center, Evangelismos Hospital, Athens, Greece; Department of Physical Education and Sport Sciences, Athens, Greece.
authors.forename: Stauroula
authors.initials: S
authors.lastname: Spetsioti
authors.affiliation: Department of Critical Care Medicine, Pulmonary Rehabilitation Center, Evangelismos Hospital, Athens, Greece; Department of Physical Education and Sport Sciences, Athens, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Nasis
authors.affiliation: 1st Department of Neurology, Aeginition Hospital, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Panagiota
authors.initials: P
authors.lastname: Manta
authors.affiliation: Department of Critical Care Medicine, Pulmonary Rehabilitation Center, Evangelismos Hospital, Athens, Greece.
authors.forename: Charis
authors.initials: C
authors.lastname: Roussos
authors.affiliation: Department of Critical Care Medicine, Pulmonary Rehabilitation Center, Evangelismos Hospital, Athens, Greece.
authors.forename: Spyros
authors.initials: S
authors.lastname: Zakynthinos
mesh_terms: D005081:Exercise Therapy; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000473:pathology*; D018657:Muscle Fibers, Slow-Twitch / Q000473:pathology; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology* / Q000503:physiopathology / Q000534:rehabilitation*; D011788:Quality of Life; D020127:Recovery of Function; D016896:Treatment Outcome