title: A better response in exercise capacity after pulmonary rehabilitation in more severe COPD patients.
abstract: OBJECTIVE
  Pulmonary rehabilitation (PR) has positive effects on exercise capacity in Chronic Obstructive Pulmonary Disease (COPD). However, not all COPD patients benefit from PR to the same extent. We investigated whether there is a patient profile, which is associated with the improvement in endurance exercise capacity.
  
  
  METHODS
  In this observational study, we included 102 COPD patients who followed PR (age 60 ± 10 (mean ± SD) years, FEV(1)%predicted 44 ± 16%, 54 men). Lung function, maximal incremental cycle testing (Wpeak, VO(2)peak, Δlactate), quadriceps force and incremental and endurance shuttle walk test (ISWT/ESWT) were performed at the start of PR. The ESWT was repeated after 7 weeks of PR.
  
  
  RESULTS
  Mean change in ESWT (ΔESWT) was 100 ± 154%. Four variables showed a statistically significant negative correlation with ΔESWT: FEV(1)%pred. (ρ = -0.20), Wpeak (ρ = -0.24), Δlactate (ρ = -0.33) and incremental shuttle walk test (ISWT) (ρ = -0.31). A cluster analysis identified two patient profiles: A profile with high ΔESWT, TLC and RV and low FEV(1), VO(2)peak, quadriceps force, Δlactate, HR(peak)%pred. and ISWT distance and a profile with low ΔESWT, TLC and RV and high FEV(1), VO(2)peak, quadriceps force, Δlactate, HR(peak)%pred. and ISWT distance.
  
  
  CONCLUSIONS
  Single variables from lung function or exercise testing at baseline have limited predictive value for response to exercise training. However, patients with worse disease status (i.e. a combination of lower FEV(1), more hyperinflation, lower exercise capacity and worse quadriceps force) improve more in endurance exercise capacity.
authors.affiliation: Department of Pulmonary Diseases, University Medical Centre Groningen, University of Groningen, P.O. Box 30001, Internal Mail Address AA11, 9700 RB Groningen, The Netherlands. w.a.altenburg@cvr.umcg.nl
authors.forename: Wytske A
authors.initials: WA
authors.lastname: Altenburg
authors.forename: Mathieu H G
authors.initials: MH
authors.lastname: de Greef
authors.forename: Nick H T
authors.initials: NH
authors.lastname: ten Hacken
authors.forename: Johan B
authors.initials: JB
authors.lastname: Wempe
mesh_terms: D000368:Aged; D005080:Exercise Test / Q000379:methods; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000534:rehabilitation*; D052097:Quadriceps Muscle / Q000503:physiopathology; D016896:Treatment Outcome
chemical_list: D019344:Lactic Acid