Random Luteinizing Hormone Often Remains Pubertal in Children Treated with the Histrelin Implant for Central Precocious Puberty

Objective To investigate the use of random ultrasensitive (US) luteinizing hormone (LH) levels to monitor children being treated with a histrelin implant for central precocious puberty (CPP). Study design This was a prospective, uncontrolled, observational study at a pediatric endocrinology tertiary center. Thirty-three children (26 girls; mean age 7.2 ± 2.5 years) treated with a histrelin implant for CPP were enrolled. A random US LH measurement was obtained at 6 months, and a gonadotropin-releasing hormone analog stimulation test was performed at 12 months. Clinic visits occurred at baseline and at 6-month intervals. Results In 59% of the patients (17 of 29), the 6-month random US LH exceeded the prepubertal range of ≤0.3 IU/L. In contrast, gonadotropin-releasing hormone analog stimulation tests revealed complete hypothalamic-pituitary-gonadal axis suppression (peak LH