title: Efficacy of lower-limb muscle training modalities in severely dyspnoeic individuals with COPD and quadriceps muscle weakness: results from the DICES trial.
abstract: BACKGROUND
  Strength training and neuromuscular electrical stimulation (NMES) improve lower-limb muscle function in dyspnoeic individuals with chronic obstructive pulmonary disease (COPD). However, high-frequency NMES (HF-NMES) and strength training have never been compared head-to-head; and effects of low-frequency NMES (LF-NMES) have never been studied in COPD. Therefore, the optimal training modality to improve lower-limb muscle function, exercise performance and other patient-related outcomes in individuals with severe COPD remains unknown.
  
  
  OBJECTIVE
  To study prospectively the efficacy of HF-NMES (75 Hz), LF-NMES (15 Hz) or strength training in severely dyspnoeic individuals with COPD with quadriceps muscle weakness at baseline.
  
  
  METHODS
  120 individuals with COPD (FEV1: 33±1% predicted, men: 52%, age: 64.8±0.8 years) were randomised to HF-NMES, LF-NMES or strength training as part of a comprehensive inpatient pulmonary rehabilitation programme. No treadmill walking or stationary cycling was provided.
  
  
  RESULTS
  Groups were comparable at baseline. Quadriceps muscle strength increased after HF-NMES (+10.8 Newton-metre (Nm)) or strength training (+6.1 Nm; both p<0.01), but not after LF-NMES (+1.4 Nm; p=0.43). Quadriceps muscle endurance, exercise performance, lower-limb fat-free mass, exercise-induced symptoms of dyspnoea and fatigue improved significantly compared with baseline after HF-NMES, LF-NMES or strength training. The increase in quadriceps muscle strength and muscle endurance was greater after HF-NMES than after LF-NMES.
  
  
  CONCLUSIONS
  HF-NMES is equally effective as strength training in severely dyspnoeic individuals with COPD and muscle weakness in strengthening the quadriceps muscles and thus may be a good alternative in this particular group of patients. HF-NMES, LF-NMES and strength training were effective in improving exercise performance in severely dyspnoeic individuals with COPD and quadriceps weakness.
  
  
  BACKGROUND
  NTR2322.
authors.affiliation: Department of Research & Education, CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Maurice J H
authors.initials: MJ
authors.lastname: Sillen
authors.affiliation: Department of Research & Education, CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Frits M E
authors.initials: FM
authors.lastname: Franssen
authors.affiliation: Department of Research & Education, CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Jeannet M L
authors.initials: JM
authors.lastname: Delbressine
authors.affiliation: Department of Research & Education, CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Anouk W
authors.initials: AW
authors.lastname: Vaes
authors.affiliation: Department of Research & Education, CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands Department of Respiratory Medicine, Maastricht University Medical Centre (MUMC+), Maastricht, The Netherlands.
authors.forename: Emiel F M
authors.initials: EF
authors.lastname: Wouters
authors.affiliation: Department of Research & Education, CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Martijn A
authors.initials: MA
authors.lastname: Spruit
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001823:Body Composition; D004417:Dyspnea / Q000503:physiopathology / Q000534:rehabilitation*; D004599:Electric Stimulation Therapy / Q000379:methods*; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D018908:Muscle Weakness / Q000503:physiopathology / Q000534:rehabilitation*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000534:rehabilitation*; D052097:Quadriceps Muscle; D055070:Resistance Training / Q000379:methods*; D016037:Single-Blind Method
keywords: COPD Pathology; Exercise; Pulmonary Rehabilitation