Isolated ACTH deficiency confirmed by ACTH radioimmunoassay

Area of Science:

• Endocrinology
• Internal Medicine

Background:

• Hypoglycemia can stem from various endocrine disorders.
• Secondary adrenocortical insufficiency is a potential cause of hypoglycemia.

Observation:

• A 28-year-old woman exhibited symptoms and biochemical markers indicative of hypoglycemia.
• Endocrine investigations revealed a lack of response in plasma ACTH and cortisol levels to insulin-induced hypoglycemia and vasopressin infusion.

Findings:

• The patient's adrenal glands demonstrated normal cortisol production following prolonged stimulation with depot tetracosactrin.
• Other anterior pituitary hormones were released normally during stimulation tests.
• ACTH (adrenocorticotropic hormone) radioimmunoassays confirmed isolated ACTH deficiency, a rare condition.

Implications:

• This case underscores the importance of comprehensive endocrine testing in unexplained hypoglycemia.
• Accurate diagnosis of isolated ACTH deficiency is crucial for appropriate management and preventing adrenal crisis.
• The study contributes to the limited literature on ACTH deficiency, supported by robust diagnostic assays.