PLOD1 and hyperprolactinemia: The mechanisms of hypothalamic hypogonadism are complex, including the disorders of gonadotropin-releasing hormone (GnRH) secretion/transportation, pulsatile release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and/or hyperprolactinemia, etc. (1) Manifestations of somnolence were common in our and the previous reports (8).