0003
EFFECT OF
GONADOTROPIN-RELEASING HORMONE ANALOGUE ON THE SOMATOTROPIN AXES’ FUNCTION
IN GIRLS WITH IDIOPATHIC CENTRAL PRECOCIOUS PUBERTY Ma HM1, Du Ml2. First Affiliated Hospital of Sun Yat-sen University
of Medical Sciences, Guangzhou, China Objectives:
To recognize the changes in the somatotropin axe’s function of girls with
Idiopathic central precocious puberty (ICPP) treated with
Gonadotropin-releasing hormone analogue(GnRHa), and to probe into the cause
of growth velocity reduction during GnRHa treatment. Methods: 14
girls with ICPP were studied. Their growth velocity at the beginning and
the end of 6-month of GnRHa treatment were observed. Maturation rates (MI)
were got from vaginal smear, serum estradiol(E2), insulin-like
growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3
(IGFBP-3) were determinated and the ratio of IGF-1 to IGFBP-3 were
calculated at the beginning and the end of 6-month of GnRHa treatment. 13
age-matched healthy prepubertal girls served as controls. Result: With 6-month GnRHa treatment, the growth velocity
reduced significantly [(8.23±1.67)cm/y
versus ( 6.27±1.54)cm/y,P=0.00091]. MI and
serum E2 concentration returned to prepubertal level. At the
beginning of GnRHa treatment, serum IGF-1, IGFBP-3 concentration and
IGF-1/IGFBP-3 were all markedly higher in ICPP girls as compared with the
controls[(0.21±0.14)μg/ml, (4.04±0.51)μg/ml and 0.051±0.024),P=0.000082, 0.023
and 0.00018 respectively]. After 6-month GnRHa treatment, serum IGF-1 and
IGFBP-3 level remained high, moreover, serum IGFBP-3 tended to increase but
not significantly[(5.29±1.24)μg/ml versus
(4.91±1.17)μg/ml, P =0.063].
Neither serum IGF-1 level nor IGF-1/IGFBP-3 changed significantly[(0.49±0.15) μg/ml versus
(0.49±0.16)μg/ml, P=0.98 and (0.093±0.020) versus (0.10±0.034), P=0.31
respectively]. Conclusion: GnRHa slows growth velocity in girls with ICPP,
which doesn’t relate to the changes of serum blood free IGF-1
concentration. Changes in local IGF-1 and IGFBP-3 concentration in the
growth plate or its IGF-1 receptor after GnRHa treatment were worth to be
further studied.