Long-term treatment of central precocious puberty with a long-acting analogue of luteinizing hormone release hormone (D-Tryp6-GnRH) in monthly injections : its possible use in normal puberty

The gonadotropin-releasing-hormone-like agonist D-Tryp6-GnRH (GnRHa) has been shown to induce reversible suppression of gonadotropins and gonadal steroids in patients with central precocious puberty. We examined the effect of a long-acting preparation of GnRHa in biodegradable microcapsules. D-Tryptophane6-GnRH, administered intramuscularly at 1 month intervals, for 12 consecutive months, on growth and skeletal maturation in 3 girls and 4 boys with neurogenic or idiopathic precocious puberty. Suppression of gonadotropin release after GnRH stimulation and gonadal steroids was maintained in all subjects. Growth velocity fell from a mean rate (+/- SEM) or 8.60 +/- 0.75 cm/year before treatment to 5.81 +/- 0.60 cm/year (p < 0.005) after 1 year. Bone age advanced a mean of 8.0 +/- 0.45 months during treatment, suggesting an increase in predicted height from the ratio delta bone age/delta chronological age. Two subjects, one of them with compensated Bartter's syndrome with normal hypothalamic pituitary-gonadal-axis, received the analogue to delay pubertal growth with the hope to improve final height. In the first one, the growth velocity fell from 9.9 cm/year to 8 cm/year and delta bone age/delta chronological age decreased from 1.28 to 1.0 and in the other subject, the growth velocity fell from 12 cm/year to 6.0 cm/year in the last year of treatment and delta bone age/delta chronological age fell from 3.2 to 0.75, indicating an improvement in predicted height.