What are other Names for this Test? (Equivalent Terms)
- Metopirone Blood Test
What is Metyrapone Blood Test? (Background Information)
- Metyrapone is a drug used to test the function of the adrenal glands. It is used to diagnose adrenal gland insufficiency and Cushing’s syndrome
- The adrenal glands are two pyramid-shaped organs that are positioned above the kidneys. They produce and release various hormones, including estrogen, dopamine, adrenaline, and cortisol
- Cortisol is a glucocorticoid stress hormone important for its anti-inflammatory effects. It also releases stored nutrients for immediate use
- The adrenal glands secrete cortisol upon stimulation by adrenocorticotropic hormone (ACTH) released by the pituitary gland, which in turn receives stimulation from corticotropin-releasing hormone (CRH) released by the hypothalamus of the brain
- Glucocorticoids, such as cortisol, are released when the body is in a state of physical or mental exertion. Cortisol increases energy availability and suppresses inflammation
- Cortisol is made from 11-deoxycortisol by the enzyme 11ß-hydroxylase. Metyrapone stops this process from being carried out by blocking the action of the enzyme
- As a result of the decreased levels of cortisol, the pituitary gland increases its production of ACTH, and thus 11-deoxycortisol levels increase, in an attempt to bring cortisol levels back to normal
- If the levels of ACTH rise, but an increase in 11-deoxycortisol does not follow, this suggests that the adrenal gland is unable to respond to stimulation by ACTH produced by the pituitary gland. In such a case, adrenal insufficiency may be the diagnosis
- If neither ACTH nor 11-deoxycortisol increases, the pituitary gland and/or hypothalamus may be dysfunctional
- The Metyrapone Blood Test consists of administering metyrapone to block cortisol production, then monitoring ACTH and 11-deoxycortisol levels in blood, to diagnose problems with the adrenal glands, pituitary gland, and/or hypothalamus
What are the Clinical Indications for performing the Metyrapone Blood Test?
Following are the clinical indicators for performing the Metyrapone Blood Test:
- Rapid weight change
- Fat deposition on the shoulders (“buffalo hump”) or face (“moon face”)
- Excessive urination
- Lesions in the mouth
- Fragile skin
- Purple streaks on the abdomen
How is the Specimen Collected for Metyrapone Blood Test?
Following is the specimen collection process for Metyrapone Blood Test:
Sample required: Blood
Process of obtaining a blood sample in adults:
- A band is wrapped around the arm, 3-4 inches above the collection site (superficial vein that lies within the elbow pit)
- The site is cleaned with 70% alcohol in an outward spiral, away from the zone of needle insertion
- The needle cap is removed and is held in line with the vein, pulling the skin tight
- With a small and quick thrust, the vein is penetrated using the needle
- The required amount of blood sample is collected by pulling the plunger of the syringe out slowly
- The wrap band is removed, gauze is placed on the collection site, and the needle is removed
- The blood is immediately transferred into the blood container, which has the appropriate preservative/clot activator/anti-coagulant
- The syringe and the needle are disposed into the appropriate “sharp container” for safe and hygienic disposal
Preparation required: No special preparation is needed prior to the test.
What is the Significance of the Metyrapone Blood Test Result?
- A high value (5-7 µg/dL of cortisol) for the Metyrapone Blood Test may point to a diagnosis of adrenal insufficiency
- In addition, an ACTH response from 10-200 pg/mL may point to a diagnosis of secondary adrenal insufficiency, whereas a higher ACTH response may point to a diagnosis of primary adrenal insufficiency
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- Cortisol’s anti-inflammatory effects make it useful for surface application through creams and gels. It may be administered onto a poison ivy rash or other area of irritation, where it may decrease swelling, but may not help in the healing process
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider of the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.