Growth and bone mineralization in small-for-gestational-age preterm infants.
BACKGROUND
Preterm infants are at risk for metabolic bone disease and suboptimal growth. This study examined the hypothesis that, apart from prematurity, intrauterine growth status (expressed as gestational age-specific birthweight standard deviation score) influences bone mineralization and body composition in early infancy.


METHODS
In this retrospective study, the groups consisted of preterm small-for-gestational-age (SGA) infants (n = 18; SGA group) and preterm appropriate-for-gestational-age (AGA) infants (n = 24; AGA group). Postnatal bone mineralization was measured at term-adjusted age (postmenstrual age, 37-42 weeks). Bone mineral content (BMC) and body composition were determined on dual-energy X-ray absorptiometry of the whole body.


RESULTS
BMC and lean mass were significantly lower in the SGA group than in the AGA group at term-adjusted age (37-42 weeks postmenstrual age). Stepwise regression analysis identified weight at examination as the most significant factor, accounting for 51% of the variance in BMC.


CONCLUSIONS
Bodyweight at term-adjusted age, rather than intrauterine growth, may affect postnatal bone mineralization in preterm low-birthweight infants. Therefore, promoting an increase in body size might increase postnatal bone mineralization in preterm SGA infants.
Division of Neonatology, Children's Medical Center, Showa University Northern Yokohama Hospital, Yokohama, Kanagawa, Japan.
Shigetaka
S
Kitazawa
Kazuo
K
Itabashi
You
Y
Umeda
Makoto
M
Inoue
Takashi
T
Nishioka
D015519:Bone Density; D001846:Bone Development / Q000502:physiology*; D001851:Bone Diseases, Metabolic / Q000378:metabolism*; D001842:Bone and Bones / Q000378:metabolism*; D002113:Calcification, Physiologic; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development*; D007235:Infant, Premature, Diseases / Q000378:metabolism*; D007236:Infant, Small for Gestational Age; D008297:Male; D012189:Retrospective Studies
bone mineral content; dual-energy X-ray absorptiometry; intrauterine growth; preterm infant; small for gestational age