Air-displacement plethysmography for the measurement of body composition in children aged 6–48 months

摘要

Introduction:Air-displacement plethysmography (ADP) is an age-appropriate method for measuring relative fat mass (%FM) in children; however, the accuracy of this method has not been evaluated in children aged 5 y or younger.Results:Mean %FM values measured by ADP (17.9 ± 8.0%) and by total body water (TBW) (23.7 ± 6.3%) were significantly different (P < 0.001). Regression analysis of %FM by ADP vs. TBW provided a line of best fit with a slope of 0.089, r2 = 0.013, and standard error of the estimate (SEE) = 6.3% FM (P = 0.40).Discussion:The error was related to child weight and %FM, but not to behaviors (movement or vocalizations) occurring during the test sequence. A large portion of the error was attributable to imprecision in measuring small volumes. As currently designed, ADP is not an accurate method for measuring %FM in young children. Further investigation of the sources of variability will provide insight into ways of improving the accuracy of this technology for this population.Methods:This study examined the accuracy of an ADP system modified for young children (BOD POD; Life Measurement, Concord, CA) by comparing %FM results from ADP with those obtained from TBW by deuterium (D2O) dilution (reference method) in 72 children aged 6–48 mo.