Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2006
Publication Date: 1/20/2007
Citation: Ellis, K.J., Yao, M., Shypailo, R.J., Urlando, A., Wong, W.W., Heird, W.C. 2007. Body-composition assessment in infancy: Air-displacement plethysmography compared with a reference 4-compartment model. American Journal of Clinical Nutrition. 85(1):90-95. Interpretive Summary: There is increasing evidence that infant nutrition during the first year of life has a significant impact on health and disease in adulthood. To understand this association, accurate measurements of the changes in body composition of infants are needed. This study was performed to assess the performance of a new infant-sized instrument, called the PEA POD that can monitor changes in body fat stores of infants. This information can be used to better define the nutritional requirements needed to support healthy growth. For this assessment, the reference model was an advanced multi-compartment device that required 3 hours to complete four separate measurements. The PEA POD measurement, on the other hand, took only 2 minutes to complete, and no blood samples were needed. Measurements in 49 healthy infants, at 2 to 23 weeks of age, were obtained. The PEA POD system provided a reliable, accurate, and immediate assessment of body fat in infants. Because of its ease of use, good precision, virtually no safety concerns, and bedside accessibility, the PEA POD system is highly suitable for monitoring changes in body composition during infant growth in both the research and clinical settings.
Technical Abstract: Background: A better understanding of the associations of early infant nutrition and growth with adult health requires accurate assessment of body composition in infancy. Objective: This study evaluated the performance of an infant-sized air-displacement plethysmograph (PEA POD Infant Body Composition System) for the measurement of body composition in infants. Design: Healthy infants (n = 49; age: 1.7–23.0 wk; weight: 2.7–7.1 kg) were examined with the PEA POD system. Reference values for percentage body fat (%BF) were obtained from a 4-compartment (4-C) body-composition model, which was based on measurements of total body water, bone mineral content, and total body potassium. Results: Mean (+/-SD) reproducibility of %BF values obtained with the PEA POD system was 0.4 +/- 1.3%. Mean %BF obtained with the PEA POD system (16.9 +/- 6.5%) did not differ significantly from that obtained with the 4-C model (16.3 +/- 7.2%), and the regression between %BF for the 4-C model and that for the PEA POD system (R2= 0.73, SEE = 3.7%BF) did not deviate significantly from the line of identity (y = x). Conclusions: The PEA POD system provided a reliable, accurate, and immediate assessment of %BF in infants. Because of its ease of use, good precision, minimum safety concerns, and bedside accessibility, the PEA POD system is highly suitable for monitoring changes in body composition during infant growth in both the research and clinical settings.