From the Guidelines
Addison's disease is not due to ACTH deficiency, but rather it is primarily caused by the destruction of the adrenal cortex, leading to a deficiency in cortisol and aldosterone production. This condition, also known as primary adrenal insufficiency, is most commonly caused by autoimmune destruction of the adrenal glands, where the body's immune system mistakenly attacks and damages the adrenal cortex [ 1 ]. Other causes of Addison's disease include infections, hemorrhage, cancer, or certain medications. In contrast, ACTH deficiency leads to secondary adrenal insufficiency, a distinct condition where the pituitary gland fails to produce sufficient ACTH to stimulate the adrenal glands.
Key Differences
- In Addison's disease, ACTH levels are elevated as the body attempts to compensate for the failing adrenal glands, while aldosterone levels are deficient.
- The treatment for Addison's disease typically involves lifelong hormone replacement therapy with glucocorticoids and mineralocorticoids to replace the hormones the adrenal glands can no longer produce.
Causes and Associations
- Approximately half of the patients with primary adrenal insufficiency have other co-existing autoimmune diseases, such as autoimmune thyroid disease, type-1 diabetes mellitus, and premature ovarian insufficiency [ 1 ].
- These combinations can be classified into several polyendocrine syndromes, including autoimmune polyendocrine syndrome type-1 (APS-1) and type-2 (APS-2) [ 1 ].
From the Research
Addison's Disease and ACTH Deficiency
- Addison's disease is a condition where the adrenal glands do not produce enough hormones, including cortisol and aldosterone [ 2 ].
- The disease can be primary or secondary, with primary adrenal insufficiency resulting from the destruction of the adrenal cortex and secondary adrenal insufficiency resulting from a lack of adrenocorticotropic hormone (ACTH) [ 3 ].
- In primary adrenal insufficiency, cortisol levels are low, and ACTH levels are high [ 2 ].
- In secondary adrenal insufficiency, both cortisol and ACTH levels are low [ 3 ].
Causes of Addison's Disease
- The most common cause of Addison's disease is autoimmune adrenalitis, which results from the destruction of the adrenal cortex [ 2 ].
- Other causes of Addison's disease include tuberculosis, fungal infections, and bleeding into the adrenal glands [ 4 ].
- Secondary adrenal insufficiency can be caused by a lack of ACTH, which can be due to a pituitary tumor or other conditions affecting the pituitary gland [ 3 ].
Diagnosis and Treatment
- The diagnosis of Addison's disease is typically made using a combination of clinical symptoms, laboratory tests, and imaging studies [ 2 ].
- Treatment of Addison's disease typically involves replacement of the deficient hormones, including cortisol and aldosterone [ 2 ].
- In some cases, treatment with continuous subcutaneous hydrocortisone infusion may be used to restore a more physiological circadian cortisol rhythm [ 5 ].