ESPE Abstracts

Background: Although it is reported that central precocious puberty (CPP) GnRH analogue (GnRHa) treatment decreases the growth velocity, its relation with IGF-1 is controversial. We aimed to investigate the effects of GnRHa treatment on IGF-1 level and the relationship between IGF-1 level and growth velocity (GV) in our study.

Method: Forty-four girls with CPP, who started breast development before the age of 8 years, were enrolled in the study. IGF-1 level was measured at the onset of treatment and at sixth month of treatment. The first year growth velocities of the patients were evaluated.

Results: The mean IGF-1 level was 317.7±127.4 at pretreatment. IGF-1 SDS according to chronologic age (CA-IGF-1) was 1.41±1.56; while IGF-1 SDS according to BA (BA-IGF-1) was 0.41±1.05. The GV SDS in the first year of treatment was 1.24±2.23. The mean level of IGF-I in the 6th month was 319.1±129.6. The 6th month CA-IGF-1 SDS was 1.12±1.30. Level of IGF-1 at diagnosis and 6th month were positively correlated with CA, BA, BA-CA, height, weight, breast stage, pubic stage, FSH, LH, estradiol, uterine length, over volume (P<0.05). CA-IGF-1 SDS at diagnosis was positively correlated with height SDS, weight SDS at diagnosis and BA-CA (P<0.05). Δ-IGF-1 SDS according to CA was positively correlated with height SDS, weight SDS at the diagnosis, height SDS, weight SDS at the first year of treatment (P<0.05). There was no correlation between IGF-1 and GV SDS but ΔIGF-1 level in patients with decreased IGF-1 level at 6th; was positively correlated with GV and GV SDS (P<0.05). We found that the patients whose IGF-1 level was decreased by treatment, have lower height SDS, CA-IGF-1 SDS and BA-IGF-1 SDS (P<0.05).

Conclusion: In our study, there was a positive correlation between IGF-1 level and GV in patients whose IGF-1 level was decreased by treatment. It suggests that starting the treatment at the beginning of puberty increases risk of the IGF-1 and growth velocity’s decrease because the patients whose IGF-1 level was decreased by treatment have lower height SDS and IGF-1 SDS. However, it should be considered that the decreased GV in patients with no IGF-1 decrease may be due to excessive suppression of sex steroids.