Benefits from the First Year of GnRHa Therapy in Boys with Idiopathic Central Precocious Puberty when Initiating Treatment After Age 9 years: Findings from a Real-world Retrospective Study

Background: GnRHa treatment was established for improving final adult height (FAH) in children presenting with Idiopathic central precocious puberty (ICPP) up to age 8, while several controversies remained for older age groups. The primary objective was to evaluate whether boys diagnosed with ICPP over 9 years of chronological age (CA) could achieve a height benefit from GnRHa treatment.

Methods: We retrospectively evaluated the medical records of 23 boys treated for idiopathic central precocious puberty between January 2018 and January 2021 at Jiangsu Children's Medical Center. All patients started treatment with intramuscular depot GnRHa at a dose of 80-100 μg/kg, followed by continuous intramuscular injection every 28 days at a dose of 60-80 μg/kg. The hormonal parameters, bone age/chronological age ratio, FAH, growth velocity (GV), tanner staging and body mass index (BMI) were assessed during the treatment period.

Results: After one course of treatment (3 months), the basal FSH and testosterone levels were reduced, while the basal LH value was not significantly changed compared with those before treatment. Furthermore, the mean BA/CA ratio reduction was statistically significant at month 12. The mean PAH following administration of GnRHa after 12 months was statistically improved compared with those at baseline. In addition, the clinical sign of puberty and GV were significantly improved and the BMI remained unchanged as desired at month 12.

Conclusions: This analysis highlighted the positive outcome on the decrease in the rate of bone maturation, with a favorable effect on progression of clinical signs of puberty. Furthermore, our study confirmed PAH was improved even in the older children at onset of treatment (ages 9-10), emphasizing the importance of personalized treatment in such population.