New charts for the assessment of body composition, according to air-displacement plethysmography, at birth and across the first 6 mo of life

• Published in: The American journal of clinical nutrition Vol. 109; no. 5; pp. 1353 - 1360
• Main Authors: Norris, Tom, Ramel, Sara E, Catalano, Patrick, Caoimh, Carol ni, Roggero, Paola, Murray, Deirdre, Fields, David A, Demerath, Ellen W, Johnson, William
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2019; American Society for Clinical Nutrition, Inc
• Subjects: Adipose Tissue; Age; air-displacement plethysmography; Birth; Birth Weight; Body Composition; Body fat; Body Fluid Compartments; Body Mass Index; Body Weight; centiles; Charts; Childbirth & labor; densitometry; Fat-free body mass; Female; fetal development; Fetuses; Gestational Age; Humans; Infant; Infant, Newborn; Infant, Premature; Infants; Ireland; Italy; lean body mass; Male; monitoring; Neonates; Newborn babies; Plethysmography; Plethysmography - methods; premature birth; reference charts; Reference Values; Sampling methods; Sex; United States; Italy; Ireland; United States > US; United States; body composition; LMS; air-displacement plethysmography; PBF; EDF; centiles; AGA; infant; reference charts; DXA; ADP
• ISSN: 0002-9165; 1938-3207; 1938-3207
• DOI: 10.1093/ajcn/nqy377

Air-displacement plethysmography (ADP) is a good candidate for monitoring body composition in newborns and young infants, but reference centile curves are lacking that allow for assessment at birth and across the first 6 mo of life. Using pooled data from 4 studies, we aimed to produce new charts for assessment according to gestational age at birth (30 + 1 to 41 + 6 wk) and postnatal age at measurement (1–27 wk). The sample comprised 222 preterm infants born in the United States who were measured at birth; 1029 term infants born in Ireland who were measured at birth; and 149 term infants born in the United States and 57 term infants born in Italy who were measured at birth, 1 and 2 wk, and 1, 2, 3, 4, 5, and 6 mo of age. Infants whose birth weights were <3rd or >97th centile of the INTERGROWTH-21st standard were excluded, thereby ensuring that the charts depict body composition of infants whose birth weights did not indicate suboptimal fetal growth. Sex-specific centiles for fat mass (kg), fat-free mass (kg), and percentage body fat were estimated using the lambda-mu-sigma (LMS) method. For each sex and measure (e.g., fat mass), the new charts comprised 2 panels. The first showed centiles according to gestational age, allowing term infants to be assessed at birth and preterm infants to be monitored until they reached term. The second showed centiles according to postnatal age, allowing all infants to be monitored to age 27 wk. The LMS values underlying the charts were presented, enabling researchers and clinicians to convert measurements to centiles and z scores. The new charts provide a single tool for the assessment of body composition, according to ADP, in infants across the first 6 mo of life and will help enhance early-life nutritional management.