title: The effect of subcutaneous injection site on absorption of human growth hormone: abdomen versus thigh.
abstract: OBJECTIVE
  To investigate whether growth hormone (GH) absorption is site dependent.
  
  
  METHODS
  Human growth hormone (hGH, Norditropin) 4 IU, was injected subcutaneously on two separate occasions: into the thigh on one occasion and into the abdomen on a second occasion. Blood was sampled for GH, insulin, glucose, non-esterified fatty acids and glycerol at baseline and hourly for 12 hours. Serum insulin-like growth factor I was measured at baseline, and after 12 and 24 hours.
  
  
  METHODS
  Eleven healthy young adults (8 M, 3 F).
  
  
  RESULTS
  Following the injection serum GH had risen by 1 hour and peaked by 3-6 hours. The peak GH and growth hormone area under the curve were significantly higher after injection in the abdomen compared with the thigh (GH peak (mean +/- SEM) 103 +/- 20 vs 41 +/- 8 mU/l, P = 0.002 and GH area 528 +/- 86 vs 239 +/- 34 mU/l h, P = 0.003 respectively). Serum insulin-like growth factor I at 12 and at 24 hours showed a significant rise from the baseline level, but no significant difference was observed between the two injection sites. No significant difference in plasma insulin, glucose, non-esterified fatty acids or glycerol was observed between the two methods of injection.
  
  
  CONCLUSIONS
  Subcutaneously injected GH is better absorbed from the abdominal site than from the thigh.
authors.affiliation: Unit of Metabolic Medicine, St Mary's Hospital Medical School, Imperial College of Technology, Science and Medicine, London, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Beshyah
authors.forename: V
authors.initials: V
authors.lastname: Anyaoku
authors.forename: R
authors.initials: R
authors.lastname: Niththyananthan
authors.forename: P
authors.initials: P
authors.lastname: Sharp
authors.forename: D G
authors.initials: DG
authors.lastname: Johnston
mesh_terms: D000005:Abdomen; D000042:Absorption; D000328:Adult; D005260:Female; D013006:Growth Hormone / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D007279:Injections, Subcutaneous / Q000379:methods*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D013848:Thigh
chemical_list: D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone