title: Impact of exacerbations of cystic fibrosis on muscle strength.
abstract: BACKGROUND
  Adult patients with cystic fibrosis have peripheral muscle weakness, which is related to exercise intolerance and poor prognosis. The influence of acute exacerbations on muscle strength has been poorly studied. This study aimed to investigate whether quadriceps force (QF), as assessed with an involuntary technique, changes during intravenous antibiotics therapy (IVAT) for an exacerbation.
  
  
  METHODS
  QF was measured in 20 patients using twitch stimulation of the femoral nerve at the day of hospitalization (day 1) and at termination (day 14) of the IVAT. Physical activity was monitored during IVAT using a SenseWear armband. Ten stable patients served as control subjects.
  
  
  RESULTS
  QF did not change during exacerbation (potentiated twitch force at day 1: 140 ± 42 N, at day 14: 140 ± 47 N), but a decrease was observed in individual patients. Changes in twitch force during exacerbation were correlated with time spent in activities of at least moderate intensity (r = 0.61, p = 0.007).
  
  
  CONCLUSIONS
  QF does not systematically decrease during exacerbations of cystic fibrosis. Individual changes in QF are well correlated with daily time spent in activities of at least moderate intensity.
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Chris
authors.initials: C
authors.lastname: Burtin
authors.forename: Hans
authors.initials: H
authors.lastname: Van Remoortel
authors.forename: Bart
authors.initials: B
authors.lastname: Vrijsen
authors.forename: Daniel
authors.initials: D
authors.lastname: Langer
authors.forename: Kristine
authors.initials: K
authors.lastname: Colpaert
authors.forename: Rik
authors.initials: R
authors.lastname: Gosselink
authors.forename: Marc
authors.initials: M
authors.lastname: Decramer
authors.forename: Lieven
authors.initials: L
authors.lastname: Dupont
authors.forename: Thierry
authors.initials: T
authors.lastname: Troosters
mesh_terms: D000328:Adult; D003550:Cystic Fibrosis / Q000503:physiopathology*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D009119:Muscle Contraction; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000503:physiopathology*