A New Air Displacement Plethysmograph for the Measurement of Body Composition in Infants

Abstract

This article introduces and evaluates the PEA POD Infant Body Composition System, an air displacement plethysmograph designed for the assessment of body composition in infants between birth and 6 mo of age. The performance of the PEA POD was evaluated by repeated testing of National Institute of Standards and Technology-traceable weights and volumes. Mass was measured in a single session. Volume was measured in four sessions during a 2-d period (five times/session for both). The mean values for repeated mass measurements were almost identical to the masses of traceable weights. The SD and CV for repeated volume measurements were 1.1-4.5 mL and 0.02-0.09%, respectively. Both the mean SD and CV were within very narrow ranges (1.4-3.1 mL for SD and 0.03-0.08% for CV) across all volume levels. Furthermore, mean CV values using results from the four sessions indicated excellent within- and between-day reliability. Regression analyses (by session or with all sessions combined) of the measured volume against actual volume gave very low standard error of the estimate (SEE) (0.853-1.957 mL) and very high R(2) (1.000), with the intercept and slope not significantly different from 0 and 1, respectively. The mean percentage error in volume measurements was < or =0.05% at all volume levels. The study findings and the operational and physical characteristics of the system indicate that the PEA POD has the potential to provide clinicians and researchers with a diagnostic and research tool that is accurate, easily used by operators, and comfortable for subjects.

QMR: validation of an infant and children body composition instrument using piglets against chemical analysis

“…The infant size instrument (PeaPod, weight limit of 8 kg) has been validated in several studies. 5,4,[38][39][40] The procedure is easy, quick and results in excellent body fat measurement precision. …”

“…3 Although there are two main technologies commercially available: air-displacement plethysmography (ADP) and dual-energy X-ray absorptiometry (DXA); both have major drawbacks. ADP has been validated in infants up to 8 kg with the PeaPod [4][5][6] and in children 45 years of age with the BodPod, [7][8][9][10] but not in infants and children between 6 months and 5 years, which constitute a major gap in measuring early childhood body composition. DXA has been validated and used in all age ranges to estimate body fat and fat-free mass (FFM).…”

Is body fat percentage a better measure of undernutrition in newborns than birth weight percentiles?

“…Recently, a new technology using air displacement plethysmography (ADP) has become available to noninvasively, accurately, and quickly measure BF% in infants from birth to 6 mo of age. ADP has been validated against the four-compartment model and biological and physical phantoms (13) and is considered the criterion method for determining BF% in neonates (14)(15)(16)(17)(18). Several studies have investigated the BF% as the indicator of neonatal nutritional status using ADP (13,(19)(20)(21).…”

Evaluation of air-displacement plethysmography for body composition assessment in preterm infants

“…The system has proven to be accurate in mass and volume measurement of inanimate objects as small as 1 kg and in full-term newborn infants weighing >2.7 kg (7)(8)(9)(10)(11).…”