AVP and hypogonadotropic hypogonadism: Hence, hypopituitarism includes central or secondary adrenal insufficiency (SAI) caused by adrenocorticotropic hormone (ACTH) deficiency, secondary hypothyroidism (SHT) caused by thyroid-stimulating hormone (TSH) deficiency, secondary hypogonadism (SHG) caused by deficiency of the gonadotroph hormones (Luteinising (LH) and Follicle Stimulating Hormones (FSH)), growth hormone deficiency (GHD), and central diabetes insipidus (CDI) caused by antidiuretic hormone (ADH or arginine vasopressin, AVP) deficiency [1].