title: Physiological correlates of pulmonary function in children with cystic fibrosis.
abstract: BACKGROUND
  Although peak aerobic capacity (VO(2peak)) has been linked to outcome in patients with cystic fibrosis (CF), measuring is time consuming, and requires expensive equipment and expertise that is not readily available in all centers. Other fitness parameters such as peak anaerobic power, measures of power and strength may be simpler to deliver in the clinic. The relationship between these measures and established outcomes such as forced expiratory volume in one second (FEV(1)) and peak aerobic power (VO(2peak)) in CF remains unclear. Therefore we evaluated (a) aerobic fitness, (b) anaerobic fitness, and (c) upper and lower body muscle strength to determine their relationship to FEV(1) and VO(2peak) in children with CF.
  
  
  METHODS
  Eighty-two patients (7-18 years) with CF (40 female) from the CF clinic at The Hospital for Sick Children in Toronto performed a maximal incremental cycling test to exhaustion. Anaerobic power (W) for 10 and 30 sec cycling trials as well as vertical jump (VJ) and hand grip strength (HG) were compared to FEV(1) and VO(2peak).
  
  
  RESULTS
  Absolute VO(2peak) (R(2)  = 0.16, P < 0.001), anaerobic power (R(2)  = 0.21, P < 0.001), and hand grip strength (R(2)  = 0.10, P = 0.003) were significantly correlated to lung function whereas measures of explosive lower body strength (VJ) were not. Anaerobic power (R(2)  = 0.16, P = 0.001) and hand grip strength (R(2)  = 0.08, P = 0.01) were related to VO(2peak). Vertical jump was correlated with VO(2peak) (R(2)  = 0.29, P < 0.001) but not FEV(1).
  
  
  CONCLUSIONS
  Simple fitness tests such as hand grip strength and anaerobic cycle tests may be useful indicators of lung health and fitness.
authors.affiliation: Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Canada; Faculty of Kinesiology, Physical Education, The University of Toronto, Toronto, Canada.
authors.forename: Greg D
authors.initials: GD
authors.lastname: Wells
authors.forename: Donna L
authors.initials: DL
authors.lastname: Wilkes
authors.forename: Jane E
authors.initials: JE
authors.lastname: Schneiderman
authors.forename: Sara
authors.initials: S
authors.lastname: Thompson
authors.forename: Allan L
authors.initials: AL
authors.lastname: Coates
authors.forename: Felix
authors.initials: F
authors.lastname: Ratjen
mesh_terms: D000293:Adolescent; D002648:Child; D003550:Cystic Fibrosis / Q000503:physiopathology*; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology
keywords: cystic fibrosis; exercise; muscle; pediatric; pulmonary function; respiratory