Determinants of body composition in breastfed infants using bioimpedance spectroscopy and ultrasound skinfolds-methods comparison.
Accurate, noninvasive, and inexpensive methods are required to measure infant body composition. Ultrasound (US) and bioimpedance spectroscopy (BIS) have been validated in adults and introduced in pediatric populations. The aim of this study was to evaluate the performance of both methods in determining percentage fat mass (%FM) in breastfed infants.



%FM of 2, 5, 9, and 12 mo-old healthy, breastfed term infants (n = 58) was calculated using BIS-derived total body water equations and skinfold equations then compared with reference models. Skinfolds were measured with US at two and four sites (biceps, suprailiac and/or triceps, and subscapular).



%FM differed widely within and between methods, with the degree of variation affected by infant age/sex. Not a single method/equation was consistent with the distributions of appropriate reference values for all age/sex groups. Moderate number of matches with references values (13-24 out of 36) was seen for both types of equations. High number of matches (25-36) was seen for US skinfold-based equations. %FM values calculated from US and BIS were not significantly different (P = 0.35).



Both BIS and US are practical for predicting %FM in infants. BIS calculations are highly dependent upon an appropriate set of validated age-matched equations.
School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Australia.
Zoya
Z
Gridneva
School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Australia.
Anna R
AR
Hepworth
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia.
Leigh C
LC
Ward
School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Australia.
Ching T
CT
Lai
School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Australia.
Peter E
PE
Hartmann
School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Australia.
Donna T
DT
Geddes
D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000886:Anthropometry / Q000379:methods*; D001823:Body Composition; D015992:Body Mass Index; D001942:Breast Feeding; D058266:Dielectric Spectroscopy; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D063766:Pediatric Obesity / Q000000981:diagnostic imaging; D012016:Reference Values; D015203:Reproducibility of Results; D012885:Skinfold Thickness; D014463:Ultrasonography