Assessment of total body fat using the skinfold technique in full-term and preterm infants.
BACKGROUND
Assessment of body composition may be of interest when the nutritional status of infants is evaluated but is often difficult since simple and valid methods are lacking. With appropriate validation, measurements based on skinfold thickness (SFT) may be useful for this purpose.


OBJECTIVE
To evaluate the potential of a published method, based on measurements of SFT, to assess total body fat (TBF) of infants; and to calculate the fat content of adipose tissue (AT) in infants using previously published information regarding AT volume and total body water.


METHODS
Forty-five full-term infants and eight infants born in gestational weeks 31-33 were studied at a postnatal age of 4-131 and 44-75 d, respectively. The body water dilution method was used to obtain reference estimates of TBF (TBF-BWD).


RESULTS
In full-term infants, TBF assessed using the skinfold method (TBF-SFT) minus TBF-BWD was 1.5+/-10.8% (mean+/-2 SD). Furthermore, TBF-SFT minus TBF-BWD (%, y) was correlated (p<0.0001) with the average of TBF-SFT and TBF-BWD (%, x), showing that TBF-SFT was too high in lean infants and too low in infants with more TBF. In the full-term infants, AT contained 0.68+/-0.14 g fat/ml. In the premature infants, TBF-SFT (%), TBF-BWD (%) and the AT fat content were similar to the corresponding figures in nine full-term newborns.


CONCLUSIONS
The results indicate that the SFT method produced inaccurate and biased estimates of TBF in infants. A considerable variation between infants regarding their AT fat content may be an important reason for these findings.
Olhager
Elisabeth
E
Department of Molecular and Clinical Medicine, Division of Paediatrics, University of Linköping, University Hospital, Linköping, Sweden. elisabeth.olhager@lio.se
Forsum
Elisabet
E
D050218:Body Fat Distribution; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D015203:Reproducibility of Results; D012885:Skinfold Thickness