What is the ACTH stimulation test (cosyntropin)?
The ACTH stimulation test, which assesses the hypothalamic-pituitary-adrenal axis, is a great tool in the diagnosis of adrenal insufficiency, although it does not usually distinguish the pituitary from the adrenal factor. This dynamic test measures serum cortisol levels before and after a dose of 1 or 250 mcg of ACTH. In patients with normal adrenal function, the cortisol level should be higher than 500 pmol / L 30 minutes after ACTH administration (may be lower in some tests).
A low cortisol level that does not rise after ACTH administration indicates an abnormal cortisol response, which is seen in primary adrenal insufficiency. However, due to adrenal insufficiency with chronic ACTH deficiency, the cortisol response is often abnormal in patients with hypopituitarism.
Your pituitary gland is a pea-sized gland located at the base of your brain. It produces a wide variety of hormones, including adrenocorticotropic hormone (ACTH).
ACTH stimulates the adrenal glands located above the kidneys to release two hormones, cortisol and adrenaline (also known as epinephrine). These hormones help your immune system respond to stress in a healthy way. Cortisol is a steroid hormone that affects many different systems in the body, including:
- Circulatory system
- Immune system
- Nervous system
- Bone metabolism
- Metabolism of nutrients such as carbohydrates, fats and proteins.
Adrenaline, or epinephrine, is a hormone used to maintain the normal nervous system and circulatory function. This hormone, along with another hormone called norepinephrine, is responsible for your defence fight or flight response when faced with a stressful situation.
If you suspect that your adrenal glands are not working properly, your healthcare provider may ask you to take an ACTH (cosyntropin) test. For this test, you must receive an injection of coctropin, a synthetic component of ACTH. You will also draw two blood samples, one before the injection and one after the injection. These samples measure the level of cortisol in your blood.
This ACTH stimulation test measures how your adrenal glands respond to ACTH in your blood. It does this by measuring the cortisol levels in your body. It is important not to confuse this test with the ACTH test, which measures the levels of ACTH in your blood.
Why do I need an ACTH stimulant test?
The ACTH stimulation test is used to diagnose adrenal insufficiency, also known as Addison’s disease. It is also used to confirm that the pituitary gland is not working properly due to hypopituitarism. Deficiency can cause secondary adrenal insufficiency as a substitute for cortisol.
As with Cushing’s syndrome, the ACTH stimulation test is used to determine the level of ACTH in the blood, as well as the level of cortisol secretion from the adrenal gland.
Below are some signs and symptoms that may alert your doctor to order an ACTH stimulus test. These codes are specific. However, they should be evaluated if they are progressive and interfere with your daily activities and normal functioning:
- Unexplained weight loss
- Low blood pressure
- Lack of appetite
- Muscular weakness
- Muscle and joint pain
- Darkening of the skin
- Humor changes
Some characteristic signs and symptoms of excessive cortisol secretion are:
- Round face
- Is Remaining (around the trunk)
- Increase in facial and body hair.
- Structural manipulations in women
- Low sex drive in men
If you experience these symptoms, your healthcare provider may order an ACTH (cosyntropin) stimulant test. This will help them determine if your symptoms are caused by dysfunctional adrenal glands.
What are the risks of the ACTH stimulation test?
There are some dangers every time you draw blood. In addition to:
- Mild headache
- Excessive bleeding
- Inflammation of the vein where the blood draws entered.
You may experience mild to moderate pain when the needle is inserted. You may also feel flushing at the puncture site after the needle has been removed. There may be slight bleeding after the needle is removed and you may develop small lesions in this area. All of these symptoms are limited and do not cause serious permanent effects.
How is the test used?
The ACTH stimulation test may be used to investigate a low cortisol test result. It may be used to help diagnose primary adrenal insufficiency (Addison disease) if your healthcare practitioner suspects that your adrenal glands may not be producing enough cortisol. The test may also be done to help determine whether a condition affecting the pituitary gland is causing low cortisol levels (secondary adrenal insufficiency).
This ACTH stimulation test is used to determine whether your adrenal glands are capable of responding to ACTH and whether this is a typical response. The Endocrine Society recommends using tests for ACTH, aldosterone (also produced by the adrenal glands), and renin (a hormone that controls aldosterone production) as part of the evaluation for primary adrenal insufficiency.
How should I prepare for the ACTH stimulation test?
Preparations for this ACTH stimulation test can vary. Make sure you get clear instructions from your healthcare provider. You will need to fast for eight hours before the test. Your provider may recommend that you stop taking certain medications 24 hours before the test. Some common medications that affect cortisol levels include (but are not limited to):
- Steroid drugs
- Male hormones
- Birth control pills
- Phenytoin (antiseptic drug)
It is important to make sure your doctor knows all the medications you are taking, including those that are over the counter.
The test will take place at the T4D Infusion Clinic on the fourth floor of the Tower building at Nationwide Children’s Hospital. Take your child to the Crossroads registration area on the first floor to register before coming to the clinic.
ACTH stimulation test
- The nurse starts the intravenous (IV) line (Image 1). The nurse may put a numbing cream on the baby’s skin before starting the IV to reduce pain.
- A blood sample is taken through an IV. The IV is used to draw blood and administer medications.
- Another name for ACTH is a medicine given by a nurse called short sine. Cortisin is released by the adrenal glands into cortisol.
- After administration of cortesin, blood samples are taken intravenously.
- There should be no hassle when drawing blood samples for your child as they are taken from an existing IV.
- At the end of the test, the IV needle is removed.
How is the ACTH (cosyntropin) stimulation test performed?
Your healthcare provider will take a blood sample when you arrive for your procedure. This blood sample measures your blood cortisol levels. Your doctor can use this sample as a reference to compare the results of a second blood test.
You will receive an injection of coctropin, a synthetic component of ACTH. This hormone must stimulate the adrenal glands to produce cortisol. Wait about an hour while your body responds to the atropine injection.
After this first hour, your healthcare provider will take a second blood sample. This pattern reflects your cortisol levels once your body has time to respond to the injection. Both blood samples will be tested to determine your cortisol levels. Usually, you will get the results of the ACTH stimulation test in one to two weeks.
After the test
- Your child can eat regular foods.
- Your child will be able to return to normal activities after the test.
- Test results take 1 to 2 weeks to return. When the report is ready, your paediatrician will talk with you about the results and future planning.
What do the results of the ACTH stimulation test mean?
Cortisol levels in the blood increase with ACTH stimulation if the adrenal glands are working properly. Test results may vary slightly, so you should check with your doctor if you are concerned.
Cortisol blood levels below the acceptable range after stimulation are considered low. These abnormal ACTH stimulation test results mean you have an adrenal condition such as a severe adrenal crisis, Addison’s disease, or hypopituitarism.
Cortisol blood levels higher than the range after ACTH stimulation may be associated with Cushing’s syndrome. More tests are needed to confirm this diagnosis. This testing process can be complicated, so talk to your healthcare provider about how to proceed.