Hypopituitarism Presenting as Recurrent Episodes of Hypoglycemia: Houssay Phenomenon

Hypopituitarism, a rare disorder, is defined as decreased production and secretion of one or more of the hormones that are normally secreted by the pituitary gland, resulting from the diseases of the pituitary gland itself or the hypothalamus. The clinical manifestations of this disorder are usually nonspecific and can lead to life-threatening complications and mortality. Here, we present a case of a 66-year-old female patient who was brought to the ER by her family with concerns of altered mentation. The altered mentation was found to be secondary to a severe hypoglycemic episode, which was later discovered to be due to underlying panhypopituitarism with secondary adrenal insufficiency. Endocrinology was consulted and recommended assessment of the hypothalamic-pituitary axis. The tests revealed low levels of serum insulin and C-peptide along with decreased levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, cortisol, free thyroxine (T4), and adrenocorticotropic hormone (ACTH). She was started on intravenous hydrocortisone and levothyroxine, which were later switched to oral hydrocortisone and levothyroxine after the stabilization of her blood glucose levels. She was later advised to follow up with endocrinology upon discharge. While evaluating a patient with hypoglycemia, it is important to keep hypopituitarism causing secondary adrenal insufficiency in mind as a differential diagnosis because it can be life-threatening if not recognized early and treated in a timely manner.