Body composition of preterm infants during infancy.
OBJECTIVE
To examine body composition in preterm infants.


METHODS
Body composition was measured by dual energy x-ray absorptiometry (DEXA) at hospital discharge, term, 12 weeks, and at 6 and 12 months corrected age in 125 infants (birthweight < or = 1750 g, gestational age < or = 34 weeks).


RESULTS
Body weight derived by DEXA accurately predicted that determined by conventional scales. In both sexes lean mass (LM), fat mass (FM), %FM, bone area (BA), bone mineral mass (BMM), and bone mineral density (BMD) increased rapidly during the study; significant changes were detectable between discharge and term. At 12 months, LM, BA, and BMM, but not FM, %FM, or BMD were greater in boys than in girls. Corrected for age, LM was less than those of the reference term infant; FM and %FM were similar; BMM was greater. Corrected for weight, LM was similar to those of the reference infant, while the FM and %FM of study infants were slightly greater.


CONCLUSIONS
DEXA accurately measures body mass. Body composition in preterm boys and girls differs. Interpretation of DEXA values may depend on whether age or body weight are regarded as the appropriate reference.
Cooke
R J
RJ
Regional Medical Physics Department Freeman Hospital Newcastle upon Tyne.
Rawlings
D J
DJ
McCormick
K
K
Griffin
I J
IJ
Faulkner
K
K
Wells
J C
JC
Smith
J S
JS
Robinson
S J
SJ
D015502:Absorptiometry, Photon; D001823:Body Composition / Q000502:physiology*; D001835:Body Weight; D015519:Bone Density / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development*; D016014:Linear Models; D008297:Male; D011446:Prospective Studies; D012737:Sex Factors