MON-240 - Beyond Mean Height Gain: Clinically Relevant Predictors of Height Outcomes in Boys With Early Puberty Treated With GnRH Agonists

Background: Data on boys with early puberty are limited, and prior studies have mainly focused on mean changes in predicted adult height (PAH) or final adult height. We aimed to identify clinically meaningful predictors of treatment response using outcomes directly applicable to counseling and treatment planning.

Methods: We retrospectively reviewed 91 boys with early puberty treated with gonadotropin-releasing hormone agonists (GnRHa) at a single center. Early puberty was defined as testicular volume =4 cc before 11 years of age, bone age (BA) advancement of at least 1 year, and peak luteinizing hormone =5 IU/L on GnRH stimulation testing. Mean paternal height was 172?5.5 cm, maternal height 159?5.1 cm, mid-parental height (MPH) 172?4.0 cm, age at diagnosis 10.1?0.5 years, baseline height 145?6.3 cm, baseline PAH 168?5.2 cm, and baseline BA 11.85?0.85 years. Treatment duration ranged from 18 months to 3 years 5 months. Multivariable analyses were performed to identify predictors of: 1) baseline PAH below MPH, 2) greater PAH improvement from baseline to treatment end, 3) final PAH =174 cm, 4) less favorable BA slowing during treatment, defined as final-minus-initial ?BA >0.5 years, 5) favorable annual growth velocity immediately before treatment discontinuation, defined as =6 cm/year, and 6) final PAH remaining below MPH.

Results: At treatment initiation, 70.3% had PAH below MPH. Higher MPH and more advanced baseline BA were independently associated with baseline PAH below MPH. Mean PAH improvement was 4.03 cm and was greater in boys with lower baseline PAH, more advanced baseline BA, and non-SGA status. Final PAH =174 cm was associated with greater baseline height, higher baseline PAH, and non-SGA status. Final PAH below MPH was associated with higher MPH, more advanced baseline BA, and shorter baseline height. Importantly, PAH improved significantly even in boys whose final PAH remained below MPH (+3.23 cm, p< 0.001). Favorable late-treatment growth velocity was strongly associated with GH co-treatment, whereas GnRHa formulation was not associated with differences in growth velocity or BA progression.

Conclusions: In boys with early puberty treated with GnRHa, height outcomes were influenced more by baseline auxology, target-height potential, BA advancement, SGA status, and GH co-treatment than by GnRHa formulation. These findings extend prior reports by providing a practical, outcome-based framework beyond mean height gain alone.

*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.*