Prediction of 1 Year Growth in Girls with Precocious Puberty with GnRH Agonist Treatment by Measurement of Growth Velocity at 3 Months after Treatment

Purpose: The aim of this study was to assess the usefulness of growth velocity at 3 months after gonadotropin- releasing hormone (GnRH) agonist treatment as a predictive value of 1 year growth velocity after treatment in girls with precocious puberty. Methods: We studied 30 Korean girls with precocious puberty whose chronologic and bone age were less than 9 years and 11 years old, respectively at diagnosis. They treated with a 4 week interval GnRH agonist subcutaneous injections for at least more than 1 year. The patients who were treated with growth hormone simultaneously exclu- ded for this study. Data were collected from chart review retrospectively. We measured heights and calculated growth velocities of the subjects at 3 months and 1 year after GnRH agonist treatment. Results: The mean chronologic age and bone age of the subjects were 8.3 ± 0.8 year and 10.4 ± 0.6 years, respec- tively. The growth velocity at 3 months, 6 months, 9 months and 1 year after GnRH agonist treatment were 7.1 ± 2.6, 6.6 ± 2.1, 5.7 ± 1.3 and 5.8 ± 0.9 cm/yr, respectively. The positive correlation between the growth velocity at 3 months and 6 months, 9 months, 1 year after GnRH agonist treatment were shown(P ˂ 0.001, P ˂ 0.001, P = 0.002, respectively). Conclusion: In this study, the growth velocity at 1 year after GnRH agonist treatment may be predicted by the growth velocity at 3 months after treatment. The patient whose growth velocity at 3 months after GnRH agnoist treatment was low would be needed to observe the growth pattern carefully and to consider combined growth hormone treatment, if needed. It may be deserve further studies to improve final height in patients with central precocious puberty in various conditions. (J Korean Soc Pediatr Endocrinol 2011;16:80-85)