Didem HELVACIOĞLU, Elif KELEŞTEMUR, İlknur KURT, Ahmet KAHVECİ, Büşra GÜRPINAR TOSUN, Abdullah BEREKET
Trends in Pediatrics - 2026;7(3):219-228
Objective: To compare first-year biochemical and auxological outcomes of monthly 3.75 mg and 3-monthly 11.25 mg depot leuprolide acetate (dLA) treatment in girls with central precocious puberty (CPP) and to evaluate factors associated with biochemical non-suppression and first-year growth velocity. Methods: This single-center prospective quasi-randomized comparative study included 87 girls with CPP treated with dLA for 12 months. Patients received either monthly 3.75 mg (n=46) or 3-monthly 11.25 mg dLA treatment (n=41). Auxological parameters, gonadotropin-releasing hormone (GnRH)-stimulated luteinizing hormone (LH) responses, and LH levels measured 40 minutes after dLA injection (40-minute post-dLA LH) were evaluated. Biochemical non-suppression was defined as a year-one 40-minute post-dLA LH level >3.07 IU/L. Logistic regression was used to identify predictors of biochemical non-suppression, and linear regression was performed to determine factors associated with first-year annual growth velocity. Results: One year after initiation of treatment, there was no difference in annual growth velocity (5.73 +/- 1.01 vs 5.81 +/- 0.92 cm/year, p=0.956), bone age, Deltabone age, and other auxological and pelvic ultrasonographic parameters between treatment groups. Year-one biochemical suppression was achieved in 33/46 patients (71.7%) in the 3.75 mg group and 33/41 patients (80.5%) in the 11.25 mg group, with no significant between-group difference (p=0.450). Biochemical non-suppression was associated with higher annual growth velocity and higher pretreatment GnRH-stimulated peak LH; in logistic regression analysis, pretreatment GnRH-stimulated peak LH was the only independent predictor of biochemical non-suppression (adjusted OR 1.04, 95% CI 1.01-1.07, p=0.012). First-year annual growth velocity correlated with 6-month GnRH-stimulated peak LH (r=0.320, p=0.003), 6-month 40-minute post-dLA LH (r=0.339, p=0.001), year-one basal LH (r=0.314, p=0.003), and year-one 40-minute post-dLA LH (r=0.517, p<0.001). In multivariable analysis, year-one 40-minute post-dLA LH remained independently associated with annual growth velocity (B=0.39, 95% CI 0.26-0.52, p<0.001), whereas other parameters did not. Conclusions: Monthly 3.75 mg and 3-monthly 11.25 mg depot leuprolide acetate provided comparable first-year auxological outcomes. Higher pretreatment GnRH-stimulated peak LH predicted biochemical non-suppression, whereas year-one 40-minute post-dLA LH level was independently associated with first-year growth velocity, suggesting that it may represent a more robust parameter for monitoring residual pubertal activity during treatment.
