title: The relationship between the GH/IGF-I axis and serum markers of bone turnover metabolism in healthy children.
abstract: BACKGROUND
  There is evidence to suggest that IGF-I plays a role in regulating bone turnover.
  
  
  OBJECTIVE
  To evaluate the relationships between serum concentrations of IGF-I and IGF-binding protein-3 (IGFBP-3), and bone metabolism markers in healthy children.
  
  
  METHODS
  Prospective cross-sectional study.
  
  
  METHODS
  A cohort of 579 boys and 540 girls, all healthy Caucasian, were included in this study. Serum IGF-I and IGFBP-3 concentrations, bone alkaline phosphatase (BAP) and CrossLaps (markers of bone formation and bone resorption respectively) levels were evaluated as a function of age, gender, pubertal stage and body mass index.
  
  
  RESULTS
  Serum IGF-I SDS levels were positively correlated with BAP and CrossLaps SDS levels before and after puberty, and also with CrossLaps during puberty (weak correlation). Serum IGFBP-3 SDS levels were positively correlated with BAP and CrossLaps levels before, during (weak correlation) and after puberty (for BAP levels only).
  
  
  CONCLUSIONS
  This study demonstrated the independent association between serum IGF-I and IGFBP-3 concentrations with both serum bone formation and resorption markers in healthy children. Physiological differences before, during and after puberty in the association of serum IGF-I and IGFBP-3 levels with the serum bone metabolism markers were found. These differences may be related to differences in interactions between sex steroid hormones and the GH/IGF-I system, bone metabolism and growth during the pubertal transition. Improvements in our understanding of life course determinants of the IGF-I system and bone metabolism are required to shed further light on the role of the GH/IGF-I axis in bone remodelling.
authors.affiliation: Pediatric Endocrinology Department, Centre de Référence des Maladies Endocriniennes Rares de la Croissance and INSERM Unit 690, Assistance Publique-Hôpitaux de Paris, Université Paris VII, Robert Debré Hospital, France. juliane.leger@rdb.aphp.fr
authors.forename: Juliane
authors.initials: J
authors.lastname: Léger
authors.forename: Isabelle
authors.initials: I
authors.lastname: Mercat
authors.forename: Corinne
authors.initials: C
authors.lastname: Alberti
authors.forename: Didier
authors.initials: D
authors.lastname: Chevenne
authors.forename: Priscilla
authors.initials: P
authors.lastname: Armoogum
authors.forename: Jean
authors.initials: J
authors.lastname: Tichet
authors.forename: Paul
authors.initials: P
authors.lastname: Czernichow
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D016723:Bone Remodeling / Q000502:physiology*; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D019382:Human Growth Hormone / Q000097:blood* / Q000502:physiology; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism* / Q000502:physiology; D008297:Male; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I