title: Lower-limb muscle function is a determinant of exercise tolerance after lung resection surgery in patients with lung cancer.
abstract: This study aims to investigate the association between exercise tolerance, pulmonary function and lower-limb muscle function in patients with lung cancer who underwent lung resection surgery in the previous year.
  
  
  
  Sixty-four patients (age: 67 ± 11 years, 66% males) performed a symptom-limited incremental cycle test to define peak oxygen consumption (VO2peak) and peak workload (Wpeak). The best of two 6-min walking distance (6MWD) tests was also included. Isometric quadriceps strength and isokinetic quadriceps endurance were measured. Post-bronchodilator spirometry, lung volumes and diffusing capacity of the lung for carbon monoxide (DLCO) measurements were assessed. Univariate correlation analysis and multiple regression analyses were performed.
  
  
  
  VO2peak, W peak and 6MWD showed moderate to strong correlations with quadriceps strength/endurance and DLCOwhile weak to moderate correlations were found with forced expiratory volume in 1 s (FEV1), functional residual capacity (FRC) and body weight. Multiple regression showed that peak isometric quadriceps strength (P < 0.001) and DLCO(P < 0.001) were significant predictors of VO2peak (explained variance R2= 0.67), while quadriceps endurance (P = 0.0015) and DLCO(P < 0.0001) were significant predictors of W peak (R2= 0.61). Quadriceps endurance capacity (P = 0.013), but not DLCO, significantly contributed to the 6MWD model (R2= 0.29).
  
  
  
  We identified a strong significant relationship between peak aerobic capacity and quadriceps muscle function and lung diffusing capacity. 6MWD was significantly related to quadriceps muscle function but not to pulmonary function. These findings suggest that accurate assessment of lower-limb muscle strength has a role in the accurate interpretation of exercise tests and in selecting optimal candidates for resistance training interventions targeting the lower-limb muscles after resection surgery.
authors.affiliation: Faculty of Medicine and Life Sciences, Rehabilitation Research Centre, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium.
authors.forename: Chris
authors.identifier: 0000-0002-1342-8554
authors.initials: C
authors.lastname: Burtin
authors.affiliation: Department of Research and Education, CIRO, Center of Expertise for Chronic Organ Failure, Horn, The Netherlands.|Department of Respiratory Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands.
authors.forename: Frits M E
authors.identifier: 0000-0002-1633-6356
authors.initials: FME
authors.lastname: Franssen
authors.affiliation: Department of Research and Education, CIRO, Center of Expertise for Chronic Organ Failure, Horn, The Netherlands.|Department of Respiratory Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands.
authors.forename: Lowie E G W
authors.initials: LEGW
authors.lastname: Vanfleteren
authors.affiliation: Department of Research and Education, CIRO, Center of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Miriam T J
authors.initials: MTJ
authors.lastname: Groenen
authors.affiliation: Department of Research and Education, CIRO, Center of Expertise for Chronic Organ Failure, Horn, The Netherlands.|Department of Respiratory Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands.
authors.forename: Emiel F M
authors.initials: EFM
authors.lastname: Wouters
authors.affiliation: Faculty of Medicine and Life Sciences, Rehabilitation Research Centre, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium.|Department of Research and Education, CIRO, Center of Expertise for Chronic Organ Failure, Horn, The Netherlands.|Department of Respiratory Medicine, Maastricht University Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands.
authors.forename: Martijn A
authors.initials: MA
authors.lastname: Spruit
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D010101:Oxygen Consumption; D011013:Pneumonectomy; D052097:Quadriceps Muscle / Q000503:physiopathology*; D012129:Respiratory Function Tests
keywords: 6-min walking distance; lung cancer; peak aerobic capacity; quadriceps endurance; quadriceps strength