ACTH stimulation test
The ACTH stimulation test is medical diagnostic test used most often to diagnose adrenal insufficiency.
How ACTH test is performed?
- In this test, a health care professional will give you an intravenous (IV) injection of man-made ACTH.
- Samples of blood are drawn before and 30 minutes or 60 minutes after the injection.
- The cortisol levels in your blood samples are measured in a lab.
Normal ACTH response test
The normal response after an ACTH injection is a rise in blood cortisol levels.
Abnormal ACTH response test
People with Addison’s disease and most people who have had secondary adrenal insufficiency for a long time have little or no increase in cortisol levels.
Cosyntropin injection is an adrenocorticotropic hormone analog intended for use as a diagnostic drug for the purpose of ACTH stimulation test.
SHORT SYNACTHEN TEST (ACTH stimulation test)
- The adrenal glands may be too damaged to respond to ACTH.
- The ACTH test may not be accurate in people who have had secondary adrenal insufficiency for a shorter time because their adrenal glands have not yet shrunk and can still respond to ACTH.
ACTH stimulation tests show the output of cortisol in response to synthetic ACTH and are done in conjunction with plasma cortisol levels taken at different times of the day. These tests need to be completed according to a strict protocol; otherwise, the results may not be definitive. Interpretation of plasma ACTH levels must be done in the context of simultaneous plasma cortisol levels.
- An increase in cortisol after stimulation by ACTH is normal.
- Post-stimulation blood cortisol should be greater than 20 mcg/dl.
Frequently asked questions - help answer these
- Do you need to fast for ACTH stimulation test?
No. This test can be performed with or without fasting at any time of the day.
- Is ACTH stimulation test safe?
Performed under experienced hands, the test is considered low risk.
- How accurate is the ACTH stimulation test?
With certain limitations as noted above, the test is a reliable indicator of the function of the adrenal glands
- What should my ACTH level be?
Normal results are: Adults: 6-76 pg/ml (1.3-16.7 pmol/L)
- What is the purpose of ACTH stimulation test?
The ACTH stimulation test measures how well the adrenal glands respond to adrenocorticotropic hormone (ACTH).
- What is ACTH?
ACTH is a hormone produced in the pituitary gland that stimulates the adrenal glands to release a hormone called cortisol.
- What is cortisol?
- How do you interpret ACTH stimulation results?
Post-stimulation blood cortisol should be greater than 20 mcg/dl
Additional FAQ's - answer these questions
* What does an ACTH stimulation test feel like?
- What happens to ACTH levels in Addison's disease?
- How long does it take to get ACTH stimulation test results?
- When should ACTH test be done?
- Dexamethasone suppression test
- Insulin tolerance test, another test used to identify sub-types of adrenal insufficiency
- Metyrapone, a drug used in the diagnosis of adrenal insufficiency
- Triple bolus test
- Renin, enzyme that converts angiotensinogen 1 to angiotensin 2, a precursor to aldosterone
- Renin–angiotensin–aldosterone system
- HPA axis, explains the connections of the hypothalamus, pituitary and adrenal glands
- Pituitary adenoma
- Adrenal adenoma