title: Validity of the ActiReg system in assessing energy requirement in chronic obstructive pulmonary disease patients.
abstract: OBJECTIVE
  Malnutrition and weight loss are common in patients with chronic obstructive pulmonary disease (COPD) and effective nutritional support relies on accurate assessment of energy requirement. This could only be performed by measuring energy expenditure using objective methods. The aim of this study was to examine the validity of the ActiReg system in assessing energy requirement in non-hospitalized patients with severe COPD, using doubly labelled water (DLW) as criterion method.
  
  
  METHODS
  Total energy expenditure (TEE) was assessed from 14 days DLW analysis in 13 patients. During the first 7 days TEE was simultaneously assessed using the ActiReg system, combining measured resting energy expenditure (REE) with physical activity monitoring.
  
  
  RESULTS
  A difference of -88 (782) kJ d(-1) (P = 0.69) was observed between the ActiReg system and DLW. REE explained 52% of the variation in TEE from DLW. Adding physical activity energy expenditure from the ActiReg system (PAEE(AR) = TEE(AR)-REE) increased the explained variation in TEE from DLW with 16%.
  
  
  CONCLUSIONS
  The ActiReg system is valid in assessing energy requirement in non-hospitalized patients with severe COPD. The unique feature of being able to discriminate within both the low intensity activity range and moderate-to-high intensity activity range makes the ActiReg system a valuable tool in clinical nutritional support.
authors.affiliation: Department of Clinical Nutrition, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden. daniel.arvidsson@nutrition.gu.se
authors.forename: Daniel
authors.initials: D
authors.lastname: Arvidsson
authors.forename: Frode
authors.initials: F
authors.lastname: Slinde
authors.forename: Anita
authors.initials: A
authors.lastname: Nordenson
authors.forename: Sven
authors.initials: S
authors.lastname: Larsson
authors.forename: Lena
authors.initials: L
authors.lastname: Hulthén
mesh_terms: D000368:Aged; D001481:Basal Metabolism / Q000502:physiology*; D001823:Body Composition; D001834:Body Water / Q000378:metabolism; D003903:Deuterium; D004734:Energy Metabolism / Q000502:physiology*; D016552:Ergometry / Q000295:instrumentation / Q000592:standards*; D015444:Exercise / Q000502:physiology; D005080:Exercise Test / Q000295:instrumentation / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009751:Nutritional Requirements; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software
chemical_list: D003903:Deuterium