[Role of leptin in development of peripubertal boys].
OBJECTIVE
To study the role of leptin in the development boys during their puberty and its relationship with insulin (INS), growth hormone (GH), estradiol (E2) and testosterone (T).


METHODS
One hundred and fifty boys with simple obese aged 7 to 17 years, 150 normal healthy boys and 150 boys with malnutrition matched for age (+/- 3 months) and height (+/- 2 cm) were selected. Serum levels of leptin, INS, GH, E2 and T were measured for them.


RESULTS
Serum level of leptin in obese group was significantly higher than that in normal group, and that in normal group was significantly higher than that in malnourished group. In the all three groups, serum level of leptin increased with age first until peak value, then began to decrease, with peak value of 6.96 microg/L at ages of 10-11 y in obese group, 10.25 microg/L at ages of 11-12 y in normal group and 5.08 microg/L at ages of 11-12 y in malnourished group. Serum level of leptin increased steadily from Tanner stages G1 to G2, then began to decrease steadily in G2 to G4. Serum level of leptin increased again in stage G5. Serum level of INS in boys increased steadily with age from 7 to 17 years old. Serum levels of GH, T and E2 in boys began to increase since 10-11 years old. Serum level of leptin positively correlated with serum level of INS and negatively correlated with serum levels of GH and T, but not correlated with serum level of E2.


CONCLUSIONS
Leptin may promote pubertal development of boys, but not the determinant factor in triggering and maintaining their pubertal development. Re-increase in level of leptin during stage G5 could inhibit secretion of GH, and signalize the end of puberty in boys.
Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin 150001, China.
Chang-Hao
CH
Sun
Ying
Y
Li
Xu
X
Wang
Rui
R
Ma
D000293:Adolescent; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D002648:Child; D004958:Estradiol / Q000378:metabolism; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D020738:Leptin / Q000097:blood / Q000502:physiology*; D008297:Male; D011627:Puberty / Q000502:physiology*; D013739:Testosterone / Q000378:metabolism
D020738:Leptin; D013739:Testosterone; D004958:Estradiol; D013006:Growth Hormone