ESPE Abstracts

Objectives: By comparing the changes of bone turnover markers (BTMs) and bone mineral density (BMD) in girls with ICPP and RPP at different treatment time, To evaluate the effect of GnRHa treatment on bone metabolism in children.

Methods: The girls with ICPP and RPP aged 7-10 years old: who undergoing treatment with GnRHa were selected, participants were categorized into the pre-treatment group (n = 61), half-year treatment (n = 63), one-year treatment (n = 49), two-year treatment(n = 40), and withdrawal group (n = 52, who had completed GnRHa treatment for a period ranging from 3 to 12 months), And 95 healthy girls aged 6-11 years old were selected as control group, including 49 cases in the pre-puberty and 46 cases in the normal pubertal group. the differences of PINP, N-MID, β-CTX levels were compared. SPSS26.0 software was used for statistical analysis.

Results: 1. In serum PINP levels, there was no difference between the pre-treatment and withdrawal groups (P >0.05), also between the one-year treatment and the two-year treatment group (P >0.05). there was no difference between the drug-withdrawal and the normal pubertal group (P >0.05). Also no difference between the treatment and the pre-puberty group (P >0.05). The serum PINP level in the drug withdrawal group exhibited a significant increase compared to that in the control group (P <0.05). The serum PINP level of girls treated with GnRHa alone was significantly lower than that of girls treated with the combination of GnRHa and rhGH treatment groups (P <0.05). 2.In serum N-MID levels, there was no difference between the pre-treatment and the withdrawal group (P >0.05). The serum N-MID level in the pre-treatment exhibited significant elevation compared to that in the all treatment groups (P <0.05). The serum N-MID level in the drug withdrawal was higher than that in the normal pubertal group (P <0.05). 3. The serum β-CTX level did not exhibit a difference between the withdrawal and the normal pubertal group (P >0.05). Also no differences among all the treatment group and the pre-puberty group (P >0.05). 4. The BMD levels did not show differences among the pre-treatment group, and all treatment group (P >0.05).

Conclusion: 1. After drug withdrawal, the bone turnover level of ICPP/RPP girls could be quickly restored, and the activity of osteoblasts and osteoclasts could be restored to the level of normally pubertal development girls, but the bone turnover rate was still higher than that of normally pubertal development girls. 2. Bone mineral density in ICPP/RPP girls was always within the normal range before and after GnRHa treatment, but bone mass accumulation in girls was slow during treatment and began to accumulate rapidly after withdrawal of GnRHa.