Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-07-02T15:12:39.909Z Has data issue: false hasContentIssue false

Evaluation of a model for total body protein mass based on dual-energy X-ray absorptiometry: comparison with a reference four-component model

Published online by Cambridge University Press:  09 March 2007

N. J. Fuller*
Affiliation:
MRC Childhood Nutrition Research Centre, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK MRC Dunn Clinical Nutrition Centre, Hills Road, Cambridge CB2 2DH, UK
J. C. K. Wells
Affiliation:
MRC Childhood Nutrition Research Centre, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
M. Elia
Affiliation:
Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK MRC Dunn Clinical Nutrition Centre, Hills Road, Cambridge CB2 2DH, UK
*
*Corresponding author: Dr Nigel J. Fuller, fax +44 (0)20 7831 9903, email N.Fuller@ich.ucl.ac.uk
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The aim of the present study was to evaluate a model of body composition for assessing total body protein (TBP) mass using dual-energy X-ray absorptiometry (DXA), with either measured or assumed total body water (TBW); it was intended to provide a less complex or demanding alternative technique to, for example, the four-component model (4-CM). The following measurements were obtained in healthy adults (n 46) aged 18–62 years, and children (n 30) aged 8–12 years: body weight (BWt), body volume (BV; under-water weighing), TBW (2H-dilution space or predicted using an assumed hydration fraction of fat-free mass (HFffm)), bone mineral content (BMC; DXA) and fat-free soft tissue (FFST; DXA). TBP was calculated using the 4-CM (TBP=3·050BWt-0·290TBW-2·734BMC-2·747BV) and the DXA model (TBP=FFST-0·2305BMC-TBW). DXA measurements were obtained using the Lunar DPX (Lunar Radiation Corporation, Madison, WI, USA) or Hologic QDR 1000/W (Hologic, Waltham, MA, USA). Precision of the DXA model for TBP with measured TBW (4·6–6·8 % mean TBP) was slightly worse than the 4-CM (4·0–5·4 %), whereas that modelled with assumed HFffm was more precise (2·4–5·2 %) because it obviated imprecision associated with measuring TBW. Agreement between the 4-CM and DXA model with measured TBW was also worse (e.g. bias, 15 % of the mean; 95 % limits of agreement up to ±39 % for adults measured on the Lunar DPX) than when a constant for HFffm was assumed (3·7 % and ±21 % respectively). Most of the variability in agreement between these various models was due to interpretation of biological factors, rather than to measurement imprecision. Therefore, the DXA model, which is less complex and demanding than the 4-CM, is of value for assessing TBP in groups of healthy subjects, but is of less value for individuals in whom there may be substantial differences from reference 4-CM estimates.

Type
Research Article
Copyright
Copyright © The Nutrition Society 2001

References

Bland, JM & Altman, DG (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet i, 307310.Google Scholar
Borovnicar, DJ, Wong, KC, Kerr, PG, Stroud, DB, Xiong, DW, Strauss, BJG & Atkins, RC (1996) Total body protein status assessed by different estimates of fat-free mass in adult peritoneal dialysis patients. European Journal of Clinical Nutrition 50, 607616.Google Scholar
Brozek, J, Grande, F, Anderson, JT & Keys, A (1963) Densitometric analysis of body composition: revision of some quantitative assumptions. Annals of New York Academy of Sciences 110, 113140.Google Scholar
Cohn, SH (1992) In vivo neutron activation analysis; a new technique in nutritional research. Journal of Nutritional Biochemistry 3, 378386.Google Scholar
Dewit, O, Fuller, NJ, Fewtrell, MS, Elia, M & Wells, JCK (2000) Whole body air displacement plethysmography compared with hydrodensitometry for body composition analysis. Archives of Disease in Childhood 82, 159164.Google Scholar
Fuller, NJ, Hardingham, CR, Graves, M, Screaton, N, Dixon, AK, Ward, LC & Elia, M (1999 a) Predicting composition of leg sections with anthropometry and bioelectrical impedance analysis, using magnetic resonance imaging as reference. Clinical Science 96, 647657.CrossRefGoogle ScholarPubMed
Fuller, NJ, Hardingham, CR, Graves, M, Screaton, N, Dixon, AK, Ward, LC & Elia, M (1999 b) Assessment of limb muscle and adipose tissue by dual-energy X-ray absorptiometry using magnetic resonance imaging for comparison. International Journal of Obesity 23, 12951302.CrossRefGoogle ScholarPubMed
Fuller, NJ, Jebb, SA, Laskey, MA, Coward, WA & Elia, M (1992 a) Four-component model for the assessment of body composition in humans: comparison with alternative methods, and evaluation of the density and hydration of fat-free mass. Clinical Science 82, 687693.CrossRefGoogle ScholarPubMed
Fuller, NJ, Laskey, MA & Elia, M (1992b) Assessment of the composition of major body regions by dual-energy X-ray absorptiometry (DEXA), with special reference to limb muscle mass. Clinical Physiology 12, 253266.CrossRefGoogle ScholarPubMed
Fuller, NJ, Sawyer, MB, Laskey, MA, Paxton, P & Elia, M (1996) Prediction of body composition in elderly men over 75 years of age. Annals of Human Biology 23, 127147.Google Scholar
Heymsfield, SB, Lichtman, S, Baumgartner, RN, Wang, J, Kamen, Y, Aliprantis, A & Pierson, RN Jr (1990) Body composition of humans: comparison of two improved four-compartment models that differ in expense, technical complexity, and radiation exposure. American Journal of Clinical Nutrition 52, 5258.Google Scholar
Hill, GL (1992) Body composition research: implications for the practice of clinical nutrition. Journal of Parenteral and Enteral Nutrition 16, 197218.CrossRefGoogle ScholarPubMed
Jebb, SA, Goldberg, GR, Jennings, G & Elia, M (1995) Dual-energy X-ray absorptiometry measurements of body composition: effects of depth and tissue thickness, including comparisons with direct analysis. Clinical Science 88, 319324.CrossRefGoogle ScholarPubMed
Jennings, G, Bluck, LJC, Wright, A & Elia, M (1999) The use of infra-red spectrophotometry for measuring body water spaces. Clinical Chemistry 45, 10771081.CrossRefGoogle Scholar
Laskey, MA (1996) Dual-energy X-ray absorptiometry and body composition. Nutrition 12, 4551.CrossRefGoogle ScholarPubMed
Lohman, TG (1989) Assessment of body composition in children. Pediatric Exercise Science 1, 1930.Google Scholar
McCrory, MA, Gomez, TD, Bernauer, EM & Molé, PA (1995) Evaluation of a new air displacement plethysmograph for measuring human body composition. Medicine and Science in Sports and Exercise 27, 16861691.Google Scholar
Murgatroyd, PR & Coward, WA (1989) An improved method for estimating changes in whole-body fat and protein mass in man. British Journal of Nutrition 62, 311314.Google Scholar
Pullicino, E, Coward, WA, Stubbs, RJ & Elia, M (1990) Bedside and field methods for assessing body composition: comparison with the deuterium dilution technique. European Journal of Clinical Nutrition 44, 753762.Google ScholarPubMed
Roubenoff, R, Kehayias, JJ, Dawson-Hughes, B & Heymsfield, SB (1993) Use of dual-energy X-ray absorptiometry in body composition studies: not yet a "gold standard". American Journal of Clinical Nutrition 58, 589591.CrossRefGoogle ScholarPubMed
Siri, WE (1961) Body composition from fluid spaces and density: analysis of methods. In Techniques for Measuring Body Composition pp. 223244 [Brozek, J and Henschel, A, editors]. Washington, DC: National Academy of Sciences – NRC.Google Scholar
Tothill, P (1995) Dual-energy X-ray absorptiometry for the measurement of bone and soft tissue composition. Clinical Nutrition 14, 263268.Google Scholar
Tothill, P, Avenell, A, Love, J & Reid, DM (1994a) Comparisons between Hologic, Lunar and Norland dual-energy X-ray absorptiometers and other techniques used for whole-body soft tissue measurements. European Journal of Clinical Nutrition 48, 781794.Google ScholarPubMed
Tothill, P, Avenell, A & Reid, DM (1994b) Precision and accuracy of measurements of whole-body bone mineral: comparisons between Hologic, Lunar and Norland dual-energy X-ray absorptiometers. British Journal of Radiology 67, 12101217.CrossRefGoogle ScholarPubMed
Wells, JCK, Fuller, NJ, Dewit, O, Fewtrell, MS, Elia, M & Cole, TJ (1999) Four-component model of body composition in children: density and hydration of fat-free mass and comparison with simpler models. American Journal of Clinical Nutrition 69, 904912.Google Scholar