Pulsatile gonadotropin-releasing hormone therapy in male patients with Kallmann's syndrome or constitutional delay of puberty.

The response to low-dose pulsatile gonadotropin-releasing hormone (GnRH) therapy was tested in three hypogonadotropic hypogonadal male patients and a boy with delayed puberty showing different luteinizing hormone responses (delta LH) to test doses of 25 micrograms GnRH intravenously before treatment. Four male patients, 16 to 20 years of age, three with Kallmann's syndrome and one with idiopathic delay of puberty, received 2 micrograms GnRH subcutaneously every 2 1/2 hours for 3 months by the use of the Zyklomat pump (Ferring GmbH, Kiel, FRG). In two patients with Kallmann's syndrome and decreased delta LH, serum testosterone did not increase during treatment, even after increasing the dosage and changing the route of administration (4 micrograms subcutaneously or 8 micrograms intravenously every 2 1/2 hours for 4 weeks with every dosage). The third patient with Kallmann's syndrome and the boy with delayed puberty, both with normal delta LH, presented normal serum testosterone after 3 months of subcutaneous low-dose treatment. The different responses to a GnRH test dose corresponding to the response to pulsatile GnRH therapy probably reflect different degrees of maturation of the pituitary gonadotrophs.