Comparison between Medgem and Deltatrac resting metabolic rate measurements

Abstract

Objective: The primary aims of this trial were to evaluate the reproducibility of a portable handheld calorimeter (Medgem) in a clinical population, and to compare its measures with a calorimeter in typical use with these patients. Design: Cross-sectional clinical validation study. Setting: Outpatient Clinical Research Center. Subjects: A total of 24 stable home nutrition support patients. Interventions: In random order three measures of resting metabolic rate (RMR) were taken after a 4-h fast, 15 min rest and 2-h abstention from exercise. Two measures were taken with the same Medgem (MG) and one with the traditional calorimeter (Deltatrac). Reproducibility of MG measures and their comparability to a Deltatrac measure were assessed by Bland-Altman analysis, with 47250 kcal/day established a priori as a clinically unacceptable error. In addition, disagreement between the two types of measures was defined as greater than 10% difference. Results: The mean difference between two MG measures was À6.8 kcal/day, with limits of agreement between 233 and À247 kcal/day and clinically acceptable. The mean difference between the Deltatrac and mean of two MG measures was À162 kcal/day, with limits of agreement between 577 and À253 kcal/day and clinically unacceptable. In all, 80% of the repeated MG RMR measures agreed within 10%, and the mean MG reading agreed with the Deltatrac in 60% of cases. Conclusions: RMR obtained using the MG calorimeter has an acceptable degree of reproducibility, and is acceptable to patients. The MG measures, however, are frequently lower than traditional measures and require further validation prior to application to practice in this vulnerable patient group.

A Systematic Review on Use of a Handheld Indirect Calorimeter to Assess Energy Needs in Adults and Children

“…Six of the 8 studies indicated that the Gem device performs very comparably (RMR range 0.1-4.0%, interclass reliability range 0.76-0.92) to traditional metabolic carts. The studies conducted by Compher et al (6) and Reeves et al (27) demonstrated that the Gem measures RMR significantly lower (RMR values range from -8.2 to -15.1%) than traditional metabolic carts do. Detailed results from the included comparison studies are presented in Table 2.…”

“…The Gem has been compared with 4 different metabolic-cart systems. Two of those studies suggest that it measures RMR significantly below the RMR values of metabolic carts (6,27), and the other 6 studies, when adjusting for subject positioning, suggest that it performs similarly to metabolic carts (1, 9, 18, 20, 30, 31, 32).…”

“…Because of this adjustment, the Gem device did not perform comparably to the reference system. The researchers did indicate that the Gem's readings have adequate reproducibility and acceptability for patients (6).…”

Estimating resting energy expenditure in patients requiring nutritional support: a survey of dietetic practice

“…More practical methods for measuring REE are under development and include the use of hand-held calorimeters, although their accuracy compared to standard calorimetry is questionable (Compher et al, 2005;Reeves et al, 2005).…”

Long-term effects of increased dietary polyunsaturated fat from walnuts on metabolic parameters in type II diabetes

“…Resting energy expenditure was measured using the BodyGem handheld indirect calorimeter (model 200-0001-01; HealtheTech, Golden, CO, USA), validated against other techniques (Melanson et al, 2004;Compher et al, 2005;Rubenbauer et al, 2006). Fasted blood samples were drawn by trained professionals and sent to a quality-assured pathology laboratory (Southern IML Pathology, Wollongong, Australia).…”