Comparison of gonadotropin-releasing hormone and gonadotropin therapy in male patients with idiopathic hypothalamic hypogonadism

Abstract

To compare pulsatile gonadotropin-releasing hormone (GnRH) therapy with gonadotropin therapy in male patients with idiopathic hypothalamic hypogonadism. Prospective study. Patients had free choice between the two forms of therapy. Patients were treated on an outpatient basis in our department. Eighteen patients of matched age (mean [+/- SD] age: 21.1 +/- 3.0 years and 23.6 +/- 7.3 years) and similar testicular volume were treated in each group. Pulsatile GnRH therapy was started with 4 micrograms GnRH subcutaneously every 2 hours using a portable pump and gonadotropin therapy with 3 x 2,500 IU human chorionic gonadotropin (hCG) weekly injected intramuscularly. After 8 to 12 weeks of hCG treatment, 150 IU human menopausal gonadotropin two to four times weekly were added. Testosterone (T) and estradiol (E2) levels increased significantly higher (T: P less than 0.03; E2; P less than 0.001) in the gonadotropin group than in the GnRH group (T: 22.5 +/- 8.1 versus 16.8 +/- 5.5 nmol/L; E2: 150 +/- 70 versus 88. +/- 59 pmol/L). Five patients developed gynecomastia during gonadotropin therapy. The rise of testicular volume was significantly more pronounced (P less than 0.001) in the GnRH group (delta testicular volume = 8.1 +/- 2.0 mL) than in the gonadotropin group (delta testicular volume = 4.8 +/- 1.8 mL). Ten patients of the GnRH and 8 of the gonadotropin group had positive sperm counts, ranging from 1.5 to 26 x 10(6) spermatozoa/mL. The latter was achieved more rapidly in the GnRH group (12 +/- 1.6 versus 20 +/- 2.3 months: P less than 0.02). Endocrine and exocrine testicular function can be normalized by both forms of therapy. Gonadotropin therapy has more side effects. Gonadotropin-releasing hormone leads to a higher testicular volume and a more rapid initiation of spermatogenesis compared with gonadotropin therapy.