Altered body composition in preterm infants at hospital discharge.
OBJECTIVE
To test the hypotheses that body size is reduced and body composition altered in preterm infants at hospital discharge.


METHODS
Preterm infants (< or = 34 weeks gestation, < or = 1750 g at birth) were enrolled. Body weight, length and head circumference were converted to standard deviation or z-scores. Body composition was measured using dual emission X-ray absorptiometry. The results were analysed using standard statistics.


RESULTS
One hundred and forty-nine infants (birth weight = 1406 +/- 248 g, gestation = 31 +/- 1.7 weeks) were studied. Postmenstrual age at discharge was 37 +/- 1.2 weeks. Z-scores for head circumference, weight and length differed (-0.1 +/- 0.6 > -1.4 +/- 0.6 > -1.9 +/- 0.6; p < 0.0001). Global fat-free mass was less in study infants than the reference infant at the same weight (2062 < 2252 g; p < 0.0001) or gestation (2062 < 2667 g; p < 0.0001). Global fat mass was greater in study infants than the reference infant at the same weight (307 > 198 g, 13 > 8%) or gestation (307 > 273 g; 13 > 9%; p < 0.0001). Changes in central fat mass closely paralleled those in global fat mass (r(2) = 0.76, p < 0.0001).


CONCLUSIONS
Reduced linear growth and a reduced fat-free mass suggest that dietary protein needs were not met before discharge. A reduced fat-free mass coupled with an increased global and central fat mass echoes concerns about the development of insulin resistance and metabolic syndrome X in these high-risk infants.
Cooke
Richard J
RJ
Department of Pediatrics, University of California Davis, Sacramento, California 95817, USA. richardjcooke@mac.com
Griffin
Ian
I
D015502:Absorptiometry, Photon; D000273:Adipose Tissue; D000367:Age Factors; D000704:Analysis of Variance; D001823:Body Composition; D015992:Body Mass Index; D049628:Body Size; D005260:Female; D005865:Gestational Age; D006801:Humans; D007227:Infant Nutritional Physiological Phenomena / Q000592:standards; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development*; D008297:Male; D010351:Patient Discharge; D011446:Prospective Studies; D012044:Regression Analysis; D012737:Sex Factors