Studies of the pituitary-Leydig cell axis in young men with hypogonadotropic hypogonadism and hyposmia: comparison with normal men, prepuberal boys, and hypopituitary patients.

Pituitary and gonadal function was studied in seven chromatin-negative men, ages 15-27 yr, with retarded sexual and somatic development, skeletal anomalies, and hyposmia. These hyposmic patients were compared with normal men, prepuberal boys and hypogonadal patients with hypopituitarism. The urinary follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels of hyposmic subjects were the same as those of normal boys and hypopituitary patients but significantly lower than those of normal men. Clomiphene citrate did not cause an increase in plasma FSH and LH levels in either hypogonadal group as it does in normal men. In contrast to hypopituitary patients, thyroid and adrenocortical function and release of growth hormone in the hyposmic subjects were normal. The plasma testosterone levels were equally low in prepuberal, hypopituitary, and hyposmic patients but were increased to a greater extent by human chorionic gonadotropin (HCG) treatment in prepuberal and hypopituitary subjects than in the hyposmic patients. Prolonged treatment with HCG has failed to return plasma testosterone levels to normal in two hyposmic patients. These observations suggest that there are defects of both pituitary and Leydig cell function in men with the syndrome of hypogonadism, skeletal anomalies, and hyposmia. They have impaired secretion of FSH and LH and a Leydig cell insensitivity to gonadotropin.