![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Leeds Metropolitan University Carnegie Faculty of Sport and Education Headingley Campus, Leeds, UK
Department of Pediatrics University of Oklahoma Health Science Center Children's Medical Research Institute's Metabolic Research Center Oklahoma City, OK
1 To whom correspondence should be addressed. E-mail: d.radley{at}leedsmet.ac.uk.
Dear Editor:
The recent paper investigating the use of adult and child-specific air displacement plethysmography (ADP) corrections by Bosy-Westphal et al. (1) is an important contribution to the field of pediatric body composition analysis. ADP is particularly suited and, as noted by the authors, increasingly being used for analysis in children and adolescents. The authors clearly demonstrated the substantial error associated with the use of adult prediction equations for the conversion of body density to percentage body fat and thoracic gas volume. A number of studies have supported the authors' findings demonstrating an overestimation of the percentage of fat in children and adolescents using the Siri (1961) (2) 2-compartment density conversion equation compared with criterion 3- and 4-compartment models (3–5). Therefore, we commend the authors on their timely and important addition to the ADP literature as it specifically pertains to pediatric populations.
However, in the evaluation of adult and child-specific body surface area prediction equations, the authors calculated and used an incorrect k constant value for the subsequent derivation of the surface area artifact correction. The reported k constant value 4.67 x 10–4 should have been –4.67 x 10–5 (personal communication, MJ Yao, Life Measurement Incorporated, Concord, CA). Although the reporting of the k constant as a positive integer appears no more than a typographical error, the incorrect exponent (–4) resulted in erroneous conclusions regarding the effect of using the adult- or children-specific body surface area prediction equations. As such, the reported 2.97% body fat overestimation using the formula of DuBois and DuBois (6) compared with Haycock's (7) formula should be only a negligible 0.297% body fat difference. Recognition of the trivial error between equations is important considering that the formula of DuBois and DuBois is used within the manufacturer's software, whereas use of Haycock's formula would require manual correction.
Finally, as a further point of note, we feel it is important that users are aware that starting with software version 2.0 (released in December, 2003), Lohman's child-specific equations for the conversion of body density to percentage body fat have been included in the BOD POD software. Additionally, the Fields et al. (8) child-specific thoracic gas volume prediction equations are now included in new models, thus eliminating the need for researchers to use adult thoracic gas volume prediction equations in pediatric populations.
Manuscript received 15 September 2005.
 |
LITERATURE CITED |
|---|
 TOP LITERATURE CITED |
|---|
1. Bosy-Westphal A, Danielzik S, Becker C, Geisler C. Onur S, Korth O, Bührens F, Müller MJ. Need for optimal body composition data analysis using air-displacement plethysmography in children and adolescents. J Nutr. 2005;135:2257–62.
2. Siri WE. Body composition from fluid spaces and density: analysis of methods. In: Brozek J, Henschel A, editors. Techniques for measuring body composition. Washington, DC: National Academy of Sciences, National Research Council; 1961:223–44.
3. Roemmich JN, Clark PA, Weltman A, Rogol AD. Alterations in growth and body composition during puberty. I. Comparing multicompartment body composition models. J Appl Physiol. 1997;83:927–35.
4. Gately PJ, Radley D, Cooke CB, Carroll S, Oldroyd B, Truscott JG, Coward WA, Wright A. Comparison of body composition methods in overweight and obese children. J Appl Physiol. 2003;95:2039–46.
5. Parker L, Reilly JJ, Slater C, Wells JC, Pitsiladis Y. Validity of six field and laboratory methods for measurement of body composition in boys. Obes Res. 2003;11:852–8.[Medline]
6. DuBois D, DuBois EF. A formula to estimate the approximate surface area if height and weight be known. Arch Intern Med. 1916;17:863–71.
7. Haycock GB, Schwartz GJ, Wilsotsky DH. Geometric method for measuring body surface area: a height-weight formula validated in infants, children and adults. J Pediatr. 1978;93:62–6.[Medline]
8. Fields DA, Hull HR, Cheline AJ, Yao M, Higgins PB. Child-specific thoracic gas volume prediction equations for air-displacement plethysmography. Obes Res. 2004;12:1797–804.[Medline]
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
