OBJECTIVE: To investigate the relationship between leptin concentrations, gonadotropic hormone concentrations, and body composition during puberty in a Dutch children cohort.
DESIGN: 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).
CONCLUSION: 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.