title: Estimation of fat-free mass in Asian neonates using bioelectrical impedance analysis.
abstract: The aims of this study were to develop and validate a prediction equation of fat-free mass (FFM) based on bioelectrical impedance analysis (BIA) and anthropometry using air-displacement plethysmography (ADP) as a reference in Asian neonates and to test the applicability of the prediction equations in an independent Western cohort. A total of 173 neonates at birth and 140 at two weeks of age were included. Multiple linear regression analysis was performed to develop the prediction equations in a two-third randomly selected subset and validated on the remaining one-third subset at each time point and in an independent Queensland cohort. FFM measured by ADP was the dependent variable, and anthropometric measures, sex and impedance quotient (L2/R50) were independent variables in the model. Accuracy of prediction equations was assessed using intra-class correlation and Bland-Altman analyses. L2/R50 was the significant predictor of FFM at week two but not at birth. Compared with the model using weight, sex and length, including L2/R50 slightly improved the prediction with a bias of 0·01 kg with 2 sd limits of agreement (LOA) (0·18, -0·20). Prediction explained 88·9 % of variation but not beyond that of anthropometry. Applying these equations to the Queensland cohort provided similar performance at the appropriate age. However, when the Queensland equations were applied to our cohort, the bias increased slightly but with similar LOA. BIA appears to have limited use in predicting FFM in the first few weeks of life compared with simple anthropometry in Asian populations. There is a need for population- and age-appropriate FFM prediction equations.
authors: 1Department of Obstetrics & Gynaecology,National University of Singapore,1E Kent Ridge Road,NUHS Tower Block,Level 12,Singapore,Singapore119228.
authors: Mya-Thway
authors: MT
authors: Tint
authors: 3School Chemistry and Molecular Biosciences,The University of Queensland,Brisbane,QLD 4072,Australia.
authors: Leigh C
authors: LC
authors: Ward
authors: 4Brenner Centre for Molecular Medicine,Singapore Institute for Clinical Sciences (SICS),Agency for Science, Technology and Research (A*STAR),30 Medical Drive,Singapore,Singapore117609.
authors: Shu E
authors: SE
authors: Soh
authors: 4Brenner Centre for Molecular Medicine,Singapore Institute for Clinical Sciences (SICS),Agency for Science, Technology and Research (A*STAR),30 Medical Drive,Singapore,Singapore117609.
authors: Izzuddin M
authors: IM
authors: Aris
authors: 5Department of Neonatology,Khoo Teck Puat - National University Children's Medical Institute,National University Health System,5 Lower Kent Ridge Road,Singapore,Singapore119074.
authors: Amutha
authors: A
authors: Chinnadurai
authors: 6Saw Swee Hock School of Public Health,Tahir Foundation Building,National University of Singapore,12 Science Drive 2,#10-01, Singapore,Singapore117549.
authors: Seang Mei
authors: SM
authors: Saw
authors: 4Brenner Centre for Molecular Medicine,Singapore Institute for Clinical Sciences (SICS),Agency for Science, Technology and Research (A*STAR),30 Medical Drive,Singapore,Singapore117609.
authors: Peter D
authors: PD
authors: Gluckman
authors: 8MRC Lifecourse Epidemiology Unit,NIHR Southampton Biomedical Research Centre,University of Southampton & University Hospital Southampton NHS Foundation Trust,Southampton General Hospital,MP 218,Tremona Road,Southampton SO16 6YD,UK.
authors: Keith M
authors: KM
authors: Godfrey
authors: 1Department of Obstetrics & Gynaecology,National University of Singapore,1E Kent Ridge Road,NUHS Tower Block,Level 12,Singapore,Singapore119228.
authors: Yap-Seng
authors: YS
authors: Chong
authors: 9Departments of Pediatrics and of Epidemiology,Biostatistics and Occupational Health,McGill University Faculty of Medicine,Purvis Hall,1020 Pine Ave,West Montreal,QC H3A 1A2,Canada.
authors: Michael S
authors: MS
authors: Kramer
authors: 10Department of Pediatric Endocrinology,KK Women's and Children's Hospital,100 Bukit Timah Road,Singapore,Singapore229899.
authors: Fabian
authors: F
authors: Yap
authors: 12UQ Centre for Clinical Research,The University of Queensland,Royal Brisbane & Women's Hospital Campus,Building 71/918,Herston,QLD 4029,Australia.
authors: Barbara
authors: B
authors: Lingwood
authors: 2Department of Pediatrics,Yong Loo Lin School of Medicine,National University of Singapore,1E Kent Ridge Road,NUHS Tower Block,Level 12,Singapore,Singapore119228.
authors: Yung Seng
authors: YS
authors: Lee
mesh_terms: D000465:Algorithms; D044466:Asian People; D001823:Body Composition; D002657:Child Development; D015331:Cohort Studies; D017097:Electric Impedance; D005260:Female; D047109:Fetal Development; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008954:Models, Biological; D041641:Musculoskeletal Development; D010993:Plethysmography, Whole Body; D011446:Prospective Studies; D011793:Queensland; D012727:Sex Characteristics; D012846:Singapore; D044465:White People
keywords: ADP air-displacement plethysmography; Air-displacement plethysmography; Asian neonates; BIA bioelectrical impedance analysis; Bioelectrical impedance analysis; FFA fat-free mass; FM fat mass; GUSTO Growing Up in Singapore Towards Healthy Outcomes; L length; LOA limits of agreement; S sex; TBW total body water; Validation; W weight