title: The relationship between leptin, gonadotropic hormones, and body composition during puberty in a Dutch children cohort.
abstract: OBJECTIVE
  To investigate the relationship between leptin concentrations, gonadotropic hormone concentrations, and body composition during puberty in a Dutch children cohort.
  
  
  METHODS
  In a cohort of 98 children, we determined anthropometric measurements, body composition, and concentrations of leptin, FSH, and LH.
  
  
  RESULTS
  Sex differences were observed from Tanner stage 1 onwards in weight, body fat percentage, and leptin/fat mass ratio. In boys and girls, the relationship between leptin concentrations and FM was weaker at Tanner stage 2 (R(2)=0.33 and R(2)=0.39; P<0.001), 3 (R(2)=0.27 and R(2)=0.36; P<0.002), and 4 (R(2)=0.21 and R(2)=0.28; P<0.03) than at Tanner stage 1 (R(2)=0.51 and R(2)=0.67; P<0.001) and 5 (R(2)=0.46 and R(2)=0.78; P<0.01). In girls, a peak in leptin concentrations (8.5+/-6.0 ng/ml) preceded a peak in LH and FSH concentrations (15.1+/-3.5 and 5.0+/-4.5 IU/l). A lead/lag relationship was observed of leptin at Tanner stage 1 to LH and FSH at Tanner stage 2 (R(2)=0.12, P<0.05 and R(2)=0.18, P<0.05). In boys, there was no peak in leptin, LH, and FSH; additionally, leptin at Tanner stage 3 was related FSH at Tanner stage 4 (R(2)=0.17, P<0.04).
  
  
  CONCLUSIONS
  In boys and girls during puberty, factors independent of fat mass become (transiently) more important in the regulation of plasma leptin concentrations. Moreover, in girls, leptin is suggested to act as a permissive factor for the onset of puberty, while, in boys, leptin has a different timing and possibly different function.
authors.affiliation: Department of Human Biology, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Rutters
authors.forename: A G
authors.initials: AG
authors.lastname: Nieuwenhuizen
authors.forename: S P M
authors.initials: SP
authors.lastname: Verhoef
authors.forename: S G T
authors.initials: SG
authors.lastname: Lemmens
authors.forename: N
authors.initials: N
authors.lastname: Vogels
authors.forename: M S
authors.initials: MS
authors.lastname: Westerterp-Plantenga