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Chen S, Scott C, Pearce JV, Farrar JS, Evans RK, Celi FS. An appraisal of whole-room indirect calorimeters and a metabolic cart for measuring resting and active metabolic rates. Sci Rep 2020; 10:14343. [PMID: 32868770 PMCID: PMC7459349 DOI: 10.1038/s41598-020-71001-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 07/24/2020] [Indexed: 12/13/2022] Open
Abstract
Whole-room indirect calorimeters (WRICs) have traditionally been used for real-time resting metabolic rate (RMR) measurements, while metabolic rate (MR) during short-interval exercises has commonly been measured by metabolic carts (MCs). This study aims to investigate the feasibility of incorporating short-interval exercises into WRIC study protocols by comparing the performance of WRICs and an MC. We assessed the 40-min RMR of 15 subjects with 2-day repeats and the 10-15 min activity MR (AMR) of 14 subjects at three intensities, using a large WRIC, a small WRIC, and an MC. We evaluated the biases between the instruments and quantified sources of variation using variance component analysis. All three instruments showed good agreement for both RMR (maximum bias = 0.07 kcal/min) and AMR assessment (maximum bias = 0.53 kcal/min). Moreover, the majority of the variability was between-subject and between-intensity variation, whereas the types of instrument contributed only a small amount to total variation in RMR (2%) and AMR (0.2%) data. In Conclusion, the good reproducibility among the instruments indicates that they may be used interchangeably in well-designed studies. Overall, WRICs can serve as an accurate and versatile means of assessing MR, capable of integrating RMR and short-interval AMR assessments into a single protocol.
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Affiliation(s)
- Shanshan Chen
- Department of Biostatistics, School of Medicine, Virginia Commonwealth University, Richmond, USA. .,Division of Endocrinology Diabetes and Metabolism, Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Sanger Hall, Room 7-007, PO Box 980111, Richmond, VA, 23298-0111, USA.
| | - Cory Scott
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, USA
| | - Janina V Pearce
- Division of Endocrinology Diabetes and Metabolism, Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Sanger Hall, Room 7-007, PO Box 980111, Richmond, VA, 23298-0111, USA
| | - Jared S Farrar
- Division of Endocrinology Diabetes and Metabolism, Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Sanger Hall, Room 7-007, PO Box 980111, Richmond, VA, 23298-0111, USA
| | - Ronald K Evans
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, USA
| | - Francesco S Celi
- Division of Endocrinology Diabetes and Metabolism, Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Sanger Hall, Room 7-007, PO Box 980111, Richmond, VA, 23298-0111, USA.
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Schoffelen PFM, Plasqui G. Classical experiments in whole-body metabolism: open-circuit respirometry-diluted flow chamber, hood, or facemask systems. Eur J Appl Physiol 2018; 118:33-49. [PMID: 29080000 PMCID: PMC5754424 DOI: 10.1007/s00421-017-3735-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/30/2017] [Indexed: 11/25/2022]
Abstract
For over two centuries, scientists have measured gas exchange in animals and humans and linked this to energy expenditure of the body. The aim of this review is to provide a comprehensive overview of open-circuit diluted flow indirect calorimetry and to help researchers to make the optimal choice for a certain system and its application. A historical perspective shows that 'open circuit diluted flow' is a technique first used in the 19th century and applicable today for room calorimeters, ventilated hood systems, and facemasks. Room calorimeters are a classic example of an open-circuit diluted flow system. The broadly applied ventilated hood calorimeters follow the same principle and can be classified as a derivative of these room calorimeters. The basic principle is that the subject breathes freely in a passing airflow that is fully captured and analyzed. Oxygen and CO2 concentrations are measured in inlet ambient air and captured outlet air. The airflow, which is adapted depending on the application (e.g., rest versus exercise), is measured. For a room indirect calorimeter, the dilution in the large room volume is also taken into account, and this is the most complex application of this type of calorimeter. Validity of the systems can be tested by alcohol burns, gas infusions and by performing repeated measurements on subjects. Using the latter, the smallest CV (%) was found for repeated VO2max tests (1.2%) with an SD of approximately 1 kJ min-1. The smallest SD was found for sleeping metabolic rate (0.11 kJ min-1) with a CV (%) of 2.4%.
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Affiliation(s)
- P F M Schoffelen
- Department of Human Biology and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre +, PO Box 616, 6200 MD, Maastricht, The Netherlands
| | - G Plasqui
- Department of Human Biology and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre +, PO Box 616, 6200 MD, Maastricht, The Netherlands.
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