title: Need for optimal body composition data analysis using air-displacement plethysmography in children and adolescents.
abstract: Air-displacement plethysmography (ADP) is now widely used for body composition measurement in pediatric populations. However, the manufacturer's software developed for adults leaves a potential bias for application in children and adolescents, and recent publications do not consistently use child-specific corrections. Therefore we analyzed child-specific ADP corrections with respect to quantity and etiology of bias compared with adult formulas. An optimal correction protocol is provided giving step-by-step instructions for calculations. In this study, 258 children and adolescents (143 girls and 115 boys ranging from 5 to 18 y) with a high prevalence of overweight or obesity (28.0% in girls and 22.6% in boys) were examined by ADP applying the manufacturer's software as well as published equations for child-specific corrections for surface area artifact (SAA), thoracic gas volume (TGV), and density of fat-free mass (FFM). Compared with child-specific equations for SAA, TGV, and density of FFM, the mean overestimation of the percentage of fat mass using the manufacturer's software was 10% in children and adolescents. Half of the bias derived from the use of Siri's equation not corrected for age-dependent differences in FFM density. An additional 3 and 2% of bias resulted from the application of adult equations for prediction of SAA and TGV, respectively. Different child-specific equations used to predict TGV did not differ in the percentage of fat mass. We conclude that there is a need for child-specific equations in ADP raw data analysis considering SAA, TGV, and density of FFM.
authors.affiliation: Institut für Humanernährung und Lebensmittelkunde der Christian-Albrechts University Kiel, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Bosy-Westphal
authors.forename: Sandra
authors.initials: S
authors.lastname: Danielzik
authors.forename: Christine
authors.initials: C
authors.lastname: Becker
authors.forename: Corinna
authors.initials: C
authors.lastname: Geisler
authors.forename: Simone
authors.initials: S
authors.lastname: Onur
authors.forename: Oliver
authors.initials: O
authors.lastname: Korth
authors.forename: Frederike
authors.initials: F
authors.lastname: Bührens
authors.forename: Manfred J
authors.initials: MJ
authors.lastname: Müller
mesh_terms: D000293:Adolescent; D000375:Aging; D016477:Artifacts; D001823:Body Composition; D015992:Body Mass Index; D001830:Body Surface Area; D001834:Body Water / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008953:Models, Anatomic; D009765:Obesity / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D010991:Plethysmography / Q000379:methods*; D012984:Software; D013909:Thorax / Q000503:physiopathology