title: Prematurity and low birth weight lead to altered bone geometry, strength, and quality in children.
abstract: OBJECTIVE
  Prematurity and low birth weight are associated with a decrease in bone mass. Aim of the study was to investigate bone geometry, strength, and quality in children born at term small for gestational age (term SGA), premature appropriate for gestational age (prem AGA), and premature SGA (prem SGA).
  
  
  METHODS
  91 patients (46 f, 45 m), mean age 11.28 years, height SDS 0.03 ± 0.21, and BMI SDS -0.31 ± 0.19. 20 were term SGA, 22 prem SGA, and 49 prem AGA. Bone geometry was assessed on the 2nd metacarpal bone, by evaluating the outer and inner diameter, the cortical area, medullary area, metacarpal index, cross-sectional area, and bone strength. Bone quality was evaluated by ultrasound and expressed as amplitude-dependent speed of sound and bone transmission time (BTT).
  
  
  RESULTS
  Term SGA, prem SGA, and prem AGA had values of bone geometry, strength, and quality significantly lower than our reference range (p < 0.05). Findings in the three groups were similar, apart from BTT, which was significantly reduced in prem SGA (p < 0.05). Fat percentage was the main determinant of BTT.
  
  
  CONCLUSIONS
  Children born either prematurely or SGA seem to have smaller and weaker bones. Those born both premature and SGA were the most affected.
authors.affiliation: Department of Pediatrics, Regional Hospital, Via L. Boehler 5, 39100, Bolzano, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Longhi
authors.affiliation: Department of Pediatrics, Regional Hospital, Via L. Boehler 5, 39100, Bolzano, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Mercolini
authors.affiliation: Department of Pediatrics, Regional Hospital, Via L. Boehler 5, 39100, Bolzano, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Carloni
authors.affiliation: Clinical Biochemistry Laboratory, Regional Hospital, Bolzano, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Nguyen
authors.affiliation: Department of Biostatistics, Regional Hospital, Bolzano, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Fanolla
authors.affiliation: Department of Pediatrics, Regional Hospital, Via L. Boehler 5, 39100, Bolzano, Italy. giorgio.radetti@asbz.it.
authors.forename: G
authors.initials: G
authors.lastname: Radetti
mesh_terms: D000293:Adolescent; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D008297:Male; D011859:Radiography; D014463:Ultrasonography
keywords: Bone geometry; Bone strength; Bone ultrasound; Prematurity; Small for gestational age