Few data are available on the outcome of boys with central precocious puberty (CPP) treated with gonadotropin-releasing hormone (GnRH) analogues. We report on final height, endocrine and exocrine testicular function, and bone mineral density (BMD) in nine males (age 16.7 +/- 1.5 years) treated with GnRH analogues from the age 6.0 +/- 1.8 years for a mean period of 5.6 +/- 2.4 years. The following parameters were evaluated: final height, serum gonadotropin and gonadal steroid levels, spermarche, semen analysis, area and volumetric BMD. Final height (-0.4 +/- 1.1 SDS) was significantly higher than pre-treatment predicted adult height (-2.0 +/- 1.2 SDS) and not significantly different than midparental height (-0.1 +/- 0.8 SDS). Pubertal response of gonadotropins to GnRH test occurred within 1.5 years (mean 0.7 +/- 0.4 years) and spermarche (n = 7) from 0.7 to 3 years (1.8 +/- 0.9 years) after the discontinuation of GnRH analogue therapy. No alteration in semen analysis was found (n = 6, sperm count, 10(6)/ml: 52.0 +/- 18.7; normal motility (%): 49.5 +/- 18.7; atypical morphology (%): 44.5 +/- 11.4). Area and volumetric BMD were not reduced (0.2 +/- 1.0 SDS and -0.1 +/- 0.9 SDS, respectively).
Conclusion: Long-term treatment with gonadotropin-releasing hormone analogues improves final height in boys with central precocious puberty. Post-therapy data demonstrating normal endocrine and exocrine testicular function support the safety of gonadotropin-releasing hormone analogues on reproductive function. Long-term pharmacological suppression of testicular function in childhood does not impair bone mineral density in late adolescence.