Body composition in children and adults by air displacement plethysmography

Abstract

Objectives: Air displacement plethysmography (ADP) may provide a partial alternative to body density (B d ) and therefore body composition measurement compared to conventional hydrodensitometry (H d ) in children. As there are no evaluation studies of ADP in children, this study had a two-fold objective: to compare B d estimates by ADP and H d ; and to compare fat estimates by both ADP and H d to fat estimates by another reference method, dual energy X-ray absorptiometry (DXA). Setting: Obesity Research Center, St. Luke'saRoosevelt Hospital, New York, USA. Subjects: One hundred and twenty subjects (66 femalesa54 males) who ranged in age from 6 ± 86 y and in body mass index (BMI, kgam 2 ) from 14.1 ± 40.0 kgam 2 met study entry criteria. Study Design: Cross-sectional study of healthy children (age 19 y) and adult group for comparison to earlier studies. Each subject completed ADP, H d , and DXA studies on the same day. Only subjects with subjectivelyjudged successful H d studies were entered into the study cohort.Results: There was a high correlation between B d by ADP and H d (B d Hd 0.11 0.8966B d ADP; r 0.93, SEE 0.008 gacm 3 , P`0.0001), although the regression line slope and intercept differed signi®cantly from 1 and 0, respectively. Additional analyses localized a small-magnitude B d bias in the child (n 48) subgroup. Both ADP and H d %fat estimates were highly correlated (r b 0.9, P`0.0001) with %fat by DXA in child and adult subgroups. Bland ± Altman analyses revealed no signi®cant %fat bias by either ADP or H d vs DXA in either children or adults, although a bias trend (P 0.11) was detected in the child subgroup. Conclusion: With additional re®nements, the air displacement plethysmography system has the potential of providing an accurate and practical method of quantifying body fat in children as it now does in adults. Sponsorship: This study was in-part supported by NIH Grants RR00645, NIDDK 42618 and NIDDK 37352.

The use of air displacement plethysmography in children and adolescents with cystic fibrosis

“…This is the first study to our knowledge that has attempted to validate ADP in children and adolescents with CF. In recent studies that have compared fatness measurements between ADP and DEXA in healthy children and adolescents, Lockner et al (2000) and Nicholson et al (2001) have demonstrated a significant negative mean difference between the methods, while a study by Nunez et al (1999) was consistent with the current study findings, showing no significant difference between the methods. Differences between findings may be attributed to interlaboratory method variation, differences in test conditions and the combined limitations of the methods (Fields et al, 2002).…”

“…ADP uses the pressure and volume relationship of Poisson's law to determine body volume, which in turn can be used to determine density and consequently fat and fat-free mass (FFM) (Dempster & Aitkens, 1995). ADP has been validated in adults (McCrory et al, 1995), and recently investigated in healthy children and adolescents, where it was found to be an acceptable, reliable and accurate technique (Nunez et al, 1999;Dewit et al, 2000;Fields & Goran, 2000;Nicholson et al, 2001;Demerath et al, 2002). However, to our knowledge no studies have examined the use of ADP in children and adolescents with CF.…”

Use of hand-to-hand impedancemetry to predict body composition of African women as measured by air displacement plethysmography

“…Whole-body ADP is a new practical alternative method (McCrory et al, 1995;Biaggi et al, 1999;Nunez et al, 1999) to more traditional body-composition reference methods. The ADP and hydrostatic weighing densitometry agree within 1% BF in adults (Fields et al, 2002).…”

Changes in thoracic gas volume with air-displacement plethysmography after a weight loss program in overweight and obese women

“…BOD POD; Life Measurement Incorporated, Concord, CA, USA), in part because of its wide applicability to many diverse populations and its relative ease both on the subject and tester as compared with more traditional techniques. This equipment has been widely validated against reference methods in healthy children, adolescents, adults and elderly (Sardinha et al, 1998;Collins et al, 1999;Levenhagen et al, 1999;Miyatake et al, 1999;Nunez et al, 1999;Wagner et al, 2000;Fields et al, 2001;Millard-Stafford et al, 2001;Bosy-Westphal et al, 2003;Silva et al, 2006). Furthermore, test-retest reliability, between-day variability, within-subject variability and between-instrument variability appear to be good to excellent (Fields et al, 2002;Ball, 2005;Going, 2005).…”