Isolated adrenocorticotrophic hormone (ACTH) deficiency presenting with recurrent hypoglycemia and hyponatremia

Isolated adrenocorticotropic deficiency (IAD) is a rare disorder characterized by secondary adrenal insufficiency (AI) with low or absent cortisol production, normal secretion of pituitary hormones other than ACTH, and the absence of structural pituitary defects. This case report highlights the atypical presentation of IAD, presenting with recurrent hypoglycemia and hyponatremia.

A 20-year-old female presented to the emergency department with a loss of consciousness. Initial laboratory evaluation revealed hypoglycemia and hyponatremia. She had a history of recurrent hospitalization for the same problem for 4 months. Further investigations showed deceased cortisol and adrenocorticotrophic (ACTH) levels. The rest of the pituitary hormones were normal. The patient was diagnosed with a case of Isolated ACTH deficiency and was started on oral prednisolone, and her symptoms resolved with no recurrence of the symptoms.

The etiology of acquired IAD remains largely unclear. However, it is sometimes associated with other autoimmune diseases, such as Hashimoto's thyroiditis. Idiopathic isolated ACTH deficiency (IIAD) is a rare condition that can present either congenitally (CIIAD) or later in life as adult idiopathic isolated ACTH deficiency (AIIAD).

Isolated ACTH deficiency can rarely present with hyponatremia concurrent with recurrent hypoglycemic episodes and hypotension. However, further research is needed to find the pathophysiology behind it.