title: Cardiopulmonary exercise testing in children with cystic fibrosis: one centre's experience.
abstract: BACKGROUND
  While exercise testing is increasingly used as a prognostic indicator in cystic fibrosis (CF), it is reported to be underused in UK CF centres, particularly in children. Here, we evaluated the cardiopulmonary exercise testing (CPET) results in children and young people with CF at CF annual review and its possible clinical value.
  
  
  METHODS
  An observational study comparing CPET results using a cycle ergometer ramp test (peak oxygen uptake (Vo2peak)) and pulmonary function (forced expiratory volume in 1 s (FEV1)) was performed with body mass index (BMI) used as a disease severity marker. Data were identified from clinical case notes and our CF database.
  
  
  RESULTS
  Thirty-eight children and young people (mean age 11±2.4, range 7-14 years; 17 males and 21 females) completed at least one CPET with 95% achieving technically satisfactory tests allowing measurement of Vo2peak. Mean Vo2peakwas 107 ±17.6% predicted, range 74%-150% predicted, with 8% having a reduced Vo2peakof <85% of predicted. Mean FEV1z-score was -0.77±1.24, range -4.42 to 2.24. We did not demonstrate a significant correlation between Vo2peak% predicted and FEV1z-score (r=0.25, p=0.13), or between Vo2peak% predicted and BMI z-score (r=-0.05, p=0.77). Twenty-eight of 38 completed a second CPET the following year with 71% showing a decline in Vo2peak(mean decline of 8% of predicted value, equivalent to 3.8 mL/kg/min).
  
  
  CONCLUSIONS
  CPET is feasible with 95% of children and young people achieving technically satisfactory assessments starting from age 7. In this group with relatively mild CF, mean Vo2peakwas normal with no significant correlation between Vo2peakand FEV1or BMI, as markers of disease severity. The majority demonstrated a normal Vo2peak. However, 71% showed a downward trend on repeat testing 12-18 months later.
authors.affiliation: Department of Respiratory Paediatrics, Royal Hospital for Children, Glasgow, UK.
authors.forename: Elise
authors.initials: E
authors.lastname: Weir
authors.affiliation: Department of Respiratory and Sleep Physiology, Royal Hospital for Children, Glasgow, UK.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Burns
authors.affiliation: Department of Respiratory Paediatrics, Royal Hospital for Children, Glasgow, UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Devenny
authors.affiliation: Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK.
authors.forename: David
authors.initials: D
authors.lastname: Young
authors.affiliation: School of Medicine, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, UK.
authors.forename: James Y
authors.initials: JY
authors.lastname: Paton
mesh_terms: D000293:Adolescent; D000886:Anthropometry / Q000379:methods; D015992:Body Mass Index; D002648:Child; D003550:Cystic Fibrosis / Q000503:physiopathology*; D016552:Ergometry / Q000379:methods; D015444:Exercise / Q000502:physiology; D005080:Exercise Test / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D012129:Respiratory Function Tests / Q000379:methods; D012189:Retrospective Studies
keywords: Cystic Fibrosis; aerobic fitness; cardiopulmonary exercise testing; pulmonary function