ESPE Abstracts

Introduction: Optimal height during pediatric and adolescent growth is a significant factor affecting a child's self-esteem and future outcomes. Aromatase Inhibitors such as Anastrozole are utilized to enhance final adult height in peripubertal boys by impeding the conversion of androgens to estrogens, a critical process in growth plate closure. However, concerns have been raised about the potential adverse effect of aromatase inhibitors on bone health, as estrogen plays a critical role in maintaining bone density and strength. The impact of Anastrozole on bone health in peripubertal boys has not been extensively investigated.

Objectives: To evaluate the efficacy of Anastrozole in increasing expected final adult height (AHP) in adolescent males with idiopathic short stature and to study the effect of Anastrozole on metacarpal bone health parameters [metacarpal index (MCI) and the bone health index (BHI)] using the standalone BoneXpert v3.2.2, in boys before and 2 years after anastrozole treatment.

Methodology: This was a retrospective observational cross-sectional study conducted using electronic medical records of 30 adolescent boys under 18 years with idiopathic short stature who received Anastrozole treatment from January 2018 to January 2022. Patients with chronic medical conditions or those treated with growth hormone were excluded. The study analyzed demographics, anthropometric measurements, diagnosis, puberty stage, and bone age radiograph data. The bone age, predicted adult height (AHP), metacarpal index (MCI) and bone health index (BHI) were measured using automated bone age radiograph analysis by BoneXpert software. The data (AHP, MCI, BHI) were analyzed using paired T-tests with a significance level of P < 0.05.

Results: The mean (SD) age of starting Anastrozole was 13.5 (1.69) years with a mean bone age SD score of 0.05 and height SD score of -1.23 before treatment. The average height gain after 1 and 2 years of Anastrozole was 8.3 cm and 13.62 cm, respectively, with an average increase in height SDS after 2 years of 0.44 (P < 0.05). AHP increased by an average of 2.97 cm after 1 year and 4.41 cm after 2 years (P < 0.05). Additionally, Anastrozole treatment did not adversely affect metacarpal bone health parameters, with significant improvements observed in MCI and BHI SD scores following treatment.

Conclusion: Anastrozole is effective in increasing the expected final adult height in adolescent males with short stature and does not compromise bone health, as evidenced by improved metacarpal bone health parameters. Further research is recommended to validate these results and assess long-term clinical implications.