[Diagnosis and management of adult-onset idiopathic hypogonadotropic hypogonadism].

Objective: To investigate the clinical features and management of male patients with adult-onset idiopathic hypogonadotropic hypogonadism (AIHH). Methods: Clinical features and treatment of six patients with AIHH between January 2010 and June 2017 were retrospectively reviewed. Results: The patients were all male, with an age of 26 (20-35) years old and they experienced complete pubertal development. The main complaints were decreased libido, erectile dysfunction and gynecomastia. Physical examination found that the testicular size was 15 (12-20) ml and they were fully virilized. The serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and total testosterone was 0.1 (0.1-0.8) U/L, 0.4 (0.1-0.9) U/L and 0.62 (0.10-0.90) nmol/L, respectively. Pituitary MRI and other pituitary hormones were all normal. Testosterone was administrated to three patients and the libido and erectile function returned to normal. Sperm was successfully induced in two patients after combined gonadotropin therapy for 4-6 months. One patient had a reversed hypothalamus-pituitary-testis axis function. Conclusions: The mechanism of male AIHH is unknown. Compared to those with congenital hypogonadotropic hypogonadism, patients with AIHH may achieve better spermatogenesis after gonadotropin therapy. Small portion of patients may have a reversal of hypothalamus-pituitary-testis axis function.