title: Bone mineral density of the lumbar spine in very-low-birth-weight infants: a longitudinal study.
abstract: To examine osteopenia in very low birth weight (VLBW) infants we used repeated dual-energy X-ray absorptiometry in a prospective study of lumbar spinal bone mineral density (BMD) in Japanese VLBW infants (birthweight 426-1498 g; n = 61, group 1) aged 40 weeks postconception to 3 years of age. Control subjects were Japanese infants with birthweight 1500-1999 g (group 2), 2000-2499 g (group 3), or more than 2500 g (group 4). BMD in group 1 during the early period after birth was very low, increased rapidly for 1 year, and then gradually increased until 3 years of age (r = 0.931, P < 0. 0001). BMD at the age of 40 weeks postconception was 0.085 +/- 0.026, 0.132 +/- 0.039, 0.178 +/- 0.042, and 0.196 +/- 0.046 g/cm(2) in groups 1, 2, 3, and 4, respectively (P < 0.0001). However, at 1 and 2 years of age no differences were observed among the groups in BMD.
  
  
  CONCLUSIONS
  This study shows that lumbar spinal BMD in VLBW infants can normalize by the age of 2 years.
authors.affiliation: Department of Pediatrics, Osaka City University Medical School, 1-4-3 Asahimachi, Abenoku, Osaka 545-8586, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ichiba
authors.forename: H
authors.initials: H
authors.lastname: Shintaku
authors.forename: M
authors.initials: M
authors.lastname: Fujimaru
authors.forename: C
authors.initials: C
authors.lastname: Hirai
authors.forename: Y
authors.initials: Y
authors.lastname: Okano
authors.forename: M
authors.initials: M
authors.lastname: Funato
mesh_terms: D015502:Absorptiometry, Photon; D015519:Bone Density; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight / Q000502:physiology*; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000502:physiology*; D008297:Male; D011446:Prospective Studies