title: Validation of the VO2000 calorimeter for measuring resting metabolic rate.
abstract: OBJECTIVE
  Metabolic carts used in laboratory settings for the measurement of resting metabolism are cumbersome limiting their use in the field. The validity of a newly developed portable calorimeter (Medical Graphics VO2000) under resting conditions was assessed in comparison to a well-established reference system, the DELTATRAC.
  
  
  METHODS
  Gas exchange and energy expenditure were measured for 25 min consecutively using the two devices. Values of the last 20 min were averaged and used in the analysis. The order of device for the first subject was randomly chosen and the calorimeters were alternated thereafter.
  
  
  RESULTS
  Among 33 subjects, acceptable measures of resting metabolism were obtained in 25 (11 men) aged 20-78 years because eight subjects (three men) either hyperventilated or did not adapt well enough to the facemask. VO(2), VCO(2), and RQ were not significantly different between devices. Small (2.8%) non-clinically relevant mean differences (-0.145+/-0.341 MJ day(-1)) were found. Results of the two devices were highly correlated (r=0.95) yielding a more accurate estimate than predictive equations.
  
  
  CONCLUSIONS
  The VO2000 calorimeter is a valid system to measure resting metabolism but the facemask may not be suitable for some people.
authors.affiliation: Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rua Leopoldo Bulhões 1480, 24020-971 Manguinhos, Rio de Janeiro, Brazil.
authors.forename: Vivian
authors.initials: V
authors.lastname: Wahrlich
authors.forename: Luiz A
authors.initials: LA
authors.lastname: Anjos
authors.forename: Scott B
authors.initials: SB
authors.lastname: Going
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Lohman
mesh_terms: D000328:Adult; D000368:Aged; D001481:Basal Metabolism / Q000502:physiology*; D002153:Calorimetry, Indirect / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000032:analysis*; D010101:Oxygen Consumption / Q000502:physiology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen