[Comparison between complete and incomplete suppression of the hypophyseal-gonadal axis in girls with central precocious puberty: effect on growth and prospective final height].

BACKGROUND: Whether short-acting or slow-release gonadotropin-releasing hormone agonists have different effects on growth and bone maturation in children with central precocious puberty is still unknown.

METHODS: In a meta-analysis, we studied 21 previously untreated girls with central precocious puberty treated with Buserelin and 22 previously untreated girls with central precocious puberty treated with Decapeptyl Depot. Duration of treatment was at least 18 months in both groups.

RESULTS: At start of therapy, chronological age, bone age, height velocity and pubertal stage were well comparable between the groups. During the first 6 months of treatment, clinical and biochemical escapes from suppression were more frequent in the Buserelin group; height velocity and bone maturation (delta bone age/delta chronological age) remained significantly higher (p < 0.0001 and p < 0.01, resp.) in Buserelin than in Decapeptyl Depot patients. In contrast to the Decapeptyl Depot group, in the Buserelin patients height standard deviation score for bone age did not change and predicted adult height decreased. From 6 to 18 months of therapy, the development of height velocity, delta bone age/delta chronological age, standard deviation score for bone age and predicted adult height showed an almost parallel course in both groups. Height velocity and bone maturation tended to be faster in the Buserelin group. Mean predicted adult height rose significantly in the Decapeptyl Depot group, but not in the Buserelin-treated girls.

CONCLUSIONS: A slow-release gonadotropin-releasing hormone agonist appears to be superior to short-acting drugs not only in terms of long-term tolerance but also for achieving the auxological objectives in central precocious puberty therapy. This is mainly due to their faster and more complete suppression of gonadotropins during the first 6 months of treatment.