Article: article from journal or magazin.
Predictors of outcome of long-term GnRH therapy in men with idiopathic hypogonadotropic hypogonadism.
Journal of Clinical Endocrinology and Metabolism
GnRH treatment is successful in inducing virilization and spermatogenesis in men with idiopathic hypogonadotropic hypogonadism (IHH). However, a small subset of IHH men, poorly characterized to date, fail to reach a normal testicular volume (TV) and produce sperm on this therapy. To determine predictors of outcome in terms of TV and sperm count, we studied 76 IHH men (38% with anosmia) undergoing GnRH therapy for 12-24 months. The population was stratified according to the baseline degree of prior pubertal development: absent (group 1, n = 52), partial (group 2, n = 18), or complete (adult onset HH; group 3, n = 6). Cryptorchidism was recorded in 40% of group 1, 5% of group 2, and none in group 3. Pulsatile GnRH therapy was initiated at 5-25 ng/kg per pulse sc and titrated to attain normal adult male testosterone (T) levels. LH, FSH, T, and inhibin B (I(B)) levels were measured serially, and maximum sperm count was recorded. A longitudinal mixed effects model was used to determine predictors of final TV. LH (97%) and T (93%) levels were normalized in the majority of IHH men. Groups 2 and 3 achieved a normal adult testicular size (92%), FSH (96%), I(B) levels (93%), and sperm in their ejaculate (100%). However, given their prior complete puberty and thus primed gonadotropes and testes, group 3 responded faster, normalizing androgen production by 2 months and completing spermatogenesis by 6 months. In contrast, group 1 failed to normalize TV (11 +/- 0.4 ml) and I(B) levels (92 +/- 6 pg/ml) by 24 months, despite normalization of their FSH levels (11 +/- 2 IU/liter). Similarly, sperm counts of group 1 plateaued well below the normal range (median of 3 x 10(6)/ml) with 18% remaining azoospermic. The independent predictors of outcome of long-term GnRH therapy were: 1) the presence of some prior pubertal development (positive predictor; group effect (beta) = 4.3; P = 0.003); 2) a baseline I(B) less than 60 pg/ml (negative predictor; beta = -3.7; P = 0.009); and 3) prior cryptorchidism (negative predictor; beta = -1.8; P = 0.05). Notably, anosmia was not an independent predictor of outcome when adjusted for other baseline variables. Our conclusions are: 1) pulsatile GnRH therapy in IHH men is very successful in inducing androgen production and spermatogenesis; 2) normalization of the LH-Leydig cell-T axis is achieved more uniformly than the FSH-Sertoli cell-I(B) axis during GnRH therapy; and 3) favorable predictors for achieving an adult testicular size and consequently optimizing spermatogenesis are prior history of sexual maturation, a baseline I(B) greater than 60 pg/ml, and absence of cryptorchidism.
Adolescent, Adult, Cohort Studies, Cryptorchidism/epidemiology, Drug Administration Schedule, Gonadotropin-Releasing Hormone/therapeutic use, Humans, Hypogonadism/drug therapy, Male, Middle Aged, Puberty, Sperm Count, Testis/anatomy & histology, Time Factors, Treatment Outcome
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