title: Increase of serum leptin after short-term pulsatile GnRH administration in children with delayed puberty.
abstract: OBJECTIVE
  Leptin is known to play an important role in pubertal development in humans, probably acting as one permissive factor for the onset of puberty. Leptin serum concentrations change during pubertal development and an initial increase before the onset of puberty has been reported. The underlying mechanism for this increase in leptin levels is unknown. We hypothesized that the pulsatile release of GnRH stimulates leptin metabolism. In this study, the effect of short-term pulsatile GnRH administration on leptin levels in children with delayed onset of puberty was investigated.
  
  
  METHODS
  Nineteen children (15 males and four females, mean age 15.5 years, range 13.1-20.5 years), who underwent evaluation for delayed sexual maturation, were included in the study. Sixteen subjects received 36 h of pulsatile intravenous GnRH, using an infusion pump that released 5 microg GnRH every 90 min. Serum concentrations of LH, FSH, testosterone, estradiol and leptin were analysed before and up to 36 h after GnRH administration. Eight patients received a single dose GnRH-agonist stimulation test (buserelin acetate test, 10 microg/kg body weight) with a 24-h follow-up (five patients underwent both tests).
  
  
  RESULTS
  Mean (+/-s.e.m.) serum leptin increased significantly (P<0.01) after 36 h of pulsatile GnRH administration (7.26+/-1.35 vs 9.75+/-1.76 ng/ml). In contrast, no increase in leptin concentrations was observed after administration of a single dose of buserelin.
  
  
  CONCLUSIONS
  These findings suggested that the increase in serum leptin at the onset of puberty is triggered by the pulsatile release of GnRH.
authors.affiliation: Department of Haematology, Oncology and Endocrinology, Children's Hospital, University of Essen, Hufelandstrasse 55, 45122 Essen, Germany. corinna.grasemann@medizin.uni-essen.de
authors.forename: Corinna
authors.initials: C
authors.lastname: Grasemann
authors.forename: Hendrika T
authors.initials: HT
authors.lastname: Wessels
authors.forename: Sabine
authors.initials: S
authors.lastname: Knauer-Fischer
authors.forename: Annette
authors.initials: A
authors.lastname: Richter-Unruh
authors.forename: Berthold P
authors.initials: BP
authors.lastname: Hauffa
mesh_terms: D000293:Adolescent; D000328:Adult; D002064:Buserelin / Q000008:administration & dosage; D004334:Drug Administration Schedule; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage* / Q000819:agonists; D006801:Humans; D007260:Infusion Pumps; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D020738:Leptin / Q000097:blood*; D008297:Male; D009994:Osmolar Concentration; D011628:Puberty, Delayed / Q000097:blood*
chemical_list: D020738:Leptin; D007987:Gonadotropin-Releasing Hormone; D002064:Buserelin