ESPE Abstracts

Objective: To explore the long-term effect of adjuvant treatment vin classic CAH 21OHD.

Methods: Clinical datas of 21OHD children with impaired growth potential (HtSDS_BA<-2) from the endocrinology clinics at the First Affiliated Hospital of Sun Yat-Sen University from January 1990 to February 2023 were included. Patients with adjuvant treatment were divided into different groups according to bone age (BA) and therapeutic drugs (letrozole, GnRHa and rhGH). The short-term effect (HtSDS_BA2-HtSDS_BA1) and the long-term effect [FAH and height gain (FAHSDS-HtSDS_BA1) were summarized and its related factors were discussed. The value of Bayley-Pinneau methods for predicting adult height (PAH_average & PAH_accelerate) in these patients was also discussed.

Results: A total of 162 children were included, among which 136/162 (83.95%) used adjuvant treatment.

1. Short-term effect: Adjuvant treatment improved the patients' linear growth with HtSDS_BA (1.63±1.09). There were no differences of HtSDS_BA2-HtSDS_BA1 in young, medium and old BA group, while better HtSDS_BA were observed in children with younger BA (-0.80±0.84 vs -1.53±1.20, P = 0.043). Better HtSDS_BA were also found in those treated with GnRHa plus letrozole compared with GnRHa alone (1.83±1.10 vs 1.09±0.99, P = 0.003).

2. Long-term effect: 84/162 had reached their final height. Patients with adjuvant therapy have better FAHSDS than those without adjuvant therapy (-1.25±1.10 vs -2.62±1.28, P = 0.000). Patients treated with GnRHa plus letrozole had better height gain than those with GnRHa alone (2.24±1.29 vs 1.40±1.28, P = 0.026). BA at the beginning of adjuvant therapy and progression of BA at the first year (△BA/△CA) were negatively correlated with height gain, while BA-CA at initiation of adjuvant therapy (BA₁-CA₁) was positively correlated with height gain (R²=0.564).

3. Predicted adult height at the end of adjuvant therapy & final adult height In boys, PAHSDS average (-1.80±1.25) was similar to FAHSDS (-1.78±1.17, P = 0.904), while PAHSDSaccelerate (-1.27 ± 1.27) was significantly higher than FAHSDS (P = 0.014). In girls, PAHSDSaverage (-1.35 ± 0.99) and PAHSDSaccelerate (-0.94 ± 0.89) was lower and higher than FAHSDS (-1.16 ± 0.89) (P = 0.039, P = 0.036, respectively).

4. No significant adverse reactions were found during the adjuvant treatment.

Conclusion: 1. Final adult height of 21-OHD children with impaired growth potential could be improved after adjuvant treatment. Better short-term efficacy were observed in younger BA. Children treated with GnRHa plus letrozole got better short-term and long-term effects than those with GnRHa alone.

2. BP average seems to be appropriate to adult height prediction in 21OHD boys after adjuvant treatment.

3. Adjuvant treatment with letrozole, GnRHa and rhGH in 21OHD children were relatively safe.

Key words: Congenital adrenal hyperplasia, 21-hydroxylase deficiency, children, adjuvant treatment, growth