title: Total energy expenditure in stable patients with cystic fibrosis.
abstract: OBJECTIVE
  Undernutrition is a common problem in patients with cystic fibrosis and is associated with a poor prognosis. The two aims of this study were to assess and compare the two main field techniques in the measurement of total energy expenditure and, secondly, to assess total energy expenditure in stable patients and compare with healthy controls.
  
  
  METHODS
  Resting energy expenditure was measured using indirect calorimetry and total energy expenditure was measured using 24-h heart rate (HR) methodology and doubly isotopically labelled water.
  
  
  RESULTS
  Seventeen patients, mean age 23 years and FEV(1)52% predicted and thirteen controls were recruited. Resting energy expenditure was higher in patients 0.24 (0.03) MJ/kg Fat-Free Mass (FFM) compared to controls 0.22 (0.02) MJ/kg FFM, P=0.02. Twenty-four hour heart rate underestimated total energy expenditure, 9.49 (1.85) MJ/day in patients compared to 11.69 (2.79) MJ/day using doubly labelled water. There was no difference in total energy expenditure in patients and controls using both methods, 11.69 (2.79) MJ/day compared to 11.38 (2.71) MJ/day using doubly isotopically labelled water.
  
  
  CONCLUSIONS
  In clinically stable young adult patients with moderately severe respiratory disease total energy expenditure is comparable to that an a control population despite in increase in resting energy expenditure and both 24-h HR and doubly isotopically labelled water are suitable for use in patients with cystic fibrosis.
authors.affiliation: Adult and Paediatric Cystic Fibrosis Centres Belfast City Hospital and Royal Belfast Hospital for Sick Children, Belfast, Northern Ireland.
authors.forename: M
authors.initials: M
authors.lastname: McCloskey
authors.forename: A O
authors.initials: AO
authors.lastname: Redmond
authors.forename: S
authors.initials: S
authors.lastname: Pyper
authors.forename: C
authors.initials: C
authors.lastname: McCabe
authors.forename: K R
authors.initials: KR
authors.lastname: Westerterp
authors.forename: J S
authors.initials: JS
authors.lastname: Elborn
mesh_terms: D000328:Adult; D001481:Basal Metabolism / Q000502:physiology; D002153:Calorimetry, Indirect; D016022:Case-Control Studies; D003550:Cystic Fibrosis / Q000150:complications / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007553:Isotope Labeling; D008297:Male; D009748:Nutrition Disorders / Q000453:epidemiology / Q000209:etiology; D011379:Prognosis