title: Biochemical markers of bone turnover in tibia fracture patients randomly assigned to growth hormone (GH) or placebo injections: Implications for detection of GH abuse.
abstract: BACKGROUND
  It has been argued that increased levels of bone remodelling markers are not suitable indicators of GH abuse, as bone injuries per se increase the expression levels of these markers.
  
  
  OBJECTIVE
  To investigate the impact of a recovering tibia fracture on circulating bone markers in subjects receiving placebo or GH treatment.
  
  
  METHODS
  A randomised, double-blind, placebo-controlled trial of up to 16weeks GH treatment, followed by a 16-week washout.
  
  
  METHODS
  Subjects (406 adult males and females) with a tibia fracture were randomly allocated within three days after surgery, to either placebo or GH treatment (15, 30 or 60μg/kg daily) until fracture healing or 16weeks after treatment initiation.
  
  
  METHODS
  IGF-I, serum C-terminal telopeptide of type I collagen (CTX), osteocalcin (OST) and bone-specific alkaline phosphatase (BAP) were measured during and after treatment.
  
  
  RESULTS
  Dose-dependent increases were observed in groups receiving GH, and mean levels in the highest GH dose group peaked at eight (IGF-I, CTX) or 12weeks (OST) after treatment initiation. Statistically significant differences between GH treatment and placebo were seen for IGF-I, CTX and OST in all GH dose groups throughout the treatment period, and persisted until eight (CTX) or 12 (OST) weeks after cessation of treatment.
  
  
  CONCLUSIONS
  IGF-I, CTX and OST are suitable candidate markers of prolonged, illicit administration of GH. Furthermore, CTX and OST have potentials to serve as markers also after cessation of GH administration.
authors.affiliation: Department of Internal Medicine and Endocrinology, University Hospital of Aarhus, Denmark. tk-h@ki.au.dk
authors.forename: Thomas
authors.initials: T
authors.lastname: Krusenstjerna-Hafstrøm
authors.forename: Michael Højby
authors.initials: MH
authors.lastname: Rasmussen
authors.forename: Michael
authors.initials: M
authors.lastname: Raschke
authors.forename: Shunmugam
authors.initials: S
authors.lastname: Govender
authors.forename: Jesper
authors.initials: J
authors.lastname: Madsen
authors.forename: Jens Sandahl
authors.initials: JS
authors.lastname: Christiansen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D016723:Bone Remodeling / Q000187:drug effects*; D024042:Collagen Type I / Q000097:blood; D004300:Doping in Sports; D004311:Double-Blind Method; D005260:Female; D019382:Human Growth Hormone / Q000008:administration & dosage*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010455:Peptides / Q000097:blood; D013978:Tibial Fractures / Q000097:blood / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D000469:Alkaline Phosphatase