[Effect of treatment with gonadotropin releasing hormone analogues in girls with idiopathic central precocious puberty].

UNLABELLED: It has been proven for more than two decades that gonadotropin releasing hormone analogue therapy is the only choice of treatment in patients with central precocious puberty.

AIMS: The aim of the authors was to assess the effect of gonadotropin releasing hormone analogue treatment on final height, body mass index, bone mineral density and ovarian function in girls with idiopathic central precocious puberty.

METHODS: Predicted adult height, target height and achieved height due to therapy was assessed in 15 girls with idiopathic precocious puberty treated with gonadotropin releasing hormone analogue. At the beginning of the treatment, the age of the girls was 7.0±0.8 years (mean±SD) and at the end of the treatment 12±0.8 years. The duration of gonadotropin-releasing hormone analogue treatment was 4.48±0.8 years. At the time of achieving final height, the age of the patients was 18.2±2.0 years and the height was 160.4±7.1 cm. When final height was reached, the authors evaluated bone mineral density Z-score values, levels of bone markers and the function of the hypothalamic-pituitary-gonadal axis. 15 healthy prepubertal girls, 15 pubertal girls and 15 girls who reached final height matched for chronological age were selected as control groups.

RESULTS: The majority of the gonadotropin releasing hormone-treated girls reached or almost reached their expected height predicted on the basis of the heights of their parents, but the therapy resulted only in a modest beneficial effect on height gain. Despite the fact that the body weight of patients increased during the treatment, there was no significant difference in their body mass index when they reached their final height as compared to controls. As compared to controls, patients had a decreased bone mineral density at the time when they reached their final height (lumbar spine 2-4 Z score, -0.27±1.2 vs. 0.5±0.7 in controls; p = 0.0377), which could be explained by their overweight that already existed before treatment, lack of exercise and poor calcium uptake. Their menarche occurred 12±4.6 months after discontinuing the treatment.

CONCLUSIONS: Gonadotropin releasing hormone analogue therapy exerts a modest beneficial effect on final height gain. There are no detrimental effects on body mass index, bone mineral density and ovarian function after treatment. Side-effects are of minor severity and they are tolerable.