ACTH stimulation test

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The ACTH stimulation test (Also called Rapid stimulation test with Acth O Synacthen test ) It is a medical test performed to determine the operation of the adrenal glands. [ first ] ​ [ 2 ] Specifically, it is used to diagnose or exclude adrenal insufficiency (Addison disease and related conditions). It is practiced by injecting adrenocorticotropa hormone (Acth) synthetic and measuring the amount of cortisol that the adrenal glands produce in response. Apart from objectifying adrenal insufficiency, this test also allows differentiating its causes. [ 3 ] ​

Method of Preparation and Administration [ To edit ]

The patient should fast for 12 hours before the start of the test, and the same must be practiced before 10 am, but as close at 7 am as possible. [ 4 ] If the patient is being treated or supplemented with glucocorticoids, DHEA, pre -cancer or adrenal extract, they must gradually withdraw safely, achieved which should still be expected a minimum of 2 weeks before undergoing the test. The recent stress and administration of gammographies can artificially increase the levels and invalidate, where appropriate, the results of the test. [ 5 ] Similarly, the therapies with Spironolactone, contraceptive, estrogen, androgens and progesterone can also affect the results of the stimulation test, both the aldosterone and cortisol. If the aldosterone is going to stimulate, the patient must refrain from ingesting salt and salty foods or with high sodium content for 24 hours before the test, in order to allow such hormone to rise as much as possible. Women must be in the first week of the menstrual cycle when the aldosterone is going to be measured. [ 6 ] The procedure that constitutes the test should be explained well to the patient before practicing it.

Initially, a first blood sample is extracted to the patient to obtain the basal level of cortisol (the serum Acth level must also be measured). Next, synthetic act is injected ( Synacthen O Cortrosyn , commercial names of the tetraracosactido and the cosintropin, respectively). Subsequently, two or three blood samples are extracted again, heparinized with approximately 20 mg (in a red lid tube that, after the last extraction, will be immediately sent to the ice -wrapped laboratory), which is done at 30 minutes , sometimes 45 minutes, and at 60 minutes of having injected the synthetic Act. [ 7 ] The test must have a minimum duration of 60 minutes. If the adrenal glands work properly, the cortisol level must be doubled in said 60 -minute period. If the cortisol level was 25 before the stimulation (basal level), after the same should reach at least 50. The majority of patients notice anything during or after the test, but a certain blush could appear on the skin, anxiety, anxiety, nausea or even an accentuated feeling of well -being.

Method and interpretation of cortisol stimulation [ To edit ]

The Hydrocortisone O cortisol It is the main glucocorticoid segregated by the human adrenal cortex and the most abundant steroid in peripheral blood, although minor amounts of corticosterone are also formed.

  • In primary adrenal insufficiency, the basal cortisol level is usually slightly low, around 15 (it can be much lower). If the ACTH stimulation test raises level to 20, the value would not be doubled and this would support the diagnosis of primary adrenal insufficiency.
  • In secondary adrenal insufficiency, the level of basal cortisol can double, triple, quadruple or more, after stimulation, based on low value. Cases have been reported in which this value comes to quintuplic (5 rising to 25 ng/dl; 6 rising to 30), sexupply (4 rising to 24; 5 rising to 30), septible (0.7 rising to 4.9 ) and decupply (2 rising to 20; 2.7 rising to 27.6). Recently, a stimulation almost multiplied by 13 (from 1.25 to 16: ascended 12.8 times) and another to multiply by 14 (1.7 rising to 24), reaching the value of 27.5 (16 times higher ) After an hour and a half of stimulation. These examples illustrate how extremes can become the results in these cases during a stimulation test with Acth. Most of them only double or triple and normally start with a basal cortisol value of at least 10. This level is so low due to the physiological deficit of Acth Natural. When synthetic Acts is administered during the test, patients adrenals react profusely since, in reality, they work well, only they cannot do it by not receiving enough natural acth from the pituitary gland. [ 7 ] ​

Some people report that their first stimulation test with Acth doubled or more cortisol from a low basal value, while another test carried out later suggested primary adrenal insufficiency (the cortisol value did not double). Several have referred the change in diagnosis made by their doctor, ruling primary adrenal insufficiency instead of high school. In secondary adrenal insufficiency, if the natural Acth deficit is extended for sufficient time, the adrenal production of cortisol can be stunned, so that it can no longer be raised before a stimulation test with Acth, with a serum value of the latter in The lower half of the range. The right thing is to maintain the diagnosis of secondary insufficiency.

Acth test generally represents the last word in cases of adrenal insufficiency, but it happens that most doctors only look for Addison’s disease. If the test does not suggest Addison (for example, in the authentic Addison the stimulation can start from 3 and rise to 4, or 6 rising to 8), doctors then value it as an obvious test of the proper adrenal proper functioning. His failure lies in not being able to appreciate any other degree of insufficiency between Addison’s disease and a healthy adrenal function. Many patients with secondary adrenal insufficiency go unnoticed, since most doctors see duplication or more, even starting from low basal levels of Acth and Cortisol, without noticing that what this indicates is a decreased production of Acth.

Serum Acth [ To edit ]

The serum Acth test must always be performed simultaneously to stimulation. This test measures the amount of Acth that secretes the pituitary. Serum Acth tests and ACTH stimulation, jointly practiced, can offer a more clear photograph, especially if secondary adrenal insufficiency is suffered.

In primary adrenal insufficiency (including Addison’s disease), the value of serum Acth must be in the upper part of the range or above it. Sometimes, in Addison’s disease, Acth will be well above the upper limit of the range, getting to register values ​​as high as hundreds and even thousands of times.

In secondary adrenal insufficiency, the value of serum Acth % of the secondary ones are within the range). A healthy value of serum Acth must be found in the upper third of the range (assuming a range of 10 – 60, as it almost always was about 3 years ago).

Method and interpretation of aldosterone stimulation [ To edit ]

ACTH stimulation test is occasionally used to stimulate aldosterone and cortisol production at the same time, [ 8 ] Which helps when determining whether, together with adrenal insufficiency, primary (hyperreninemic) or secondary (hyporareninemic) is also present. The natural human actr exerts a small influence on aldosterone, but the amount of synthetic Acts that is administered during stimulation exceeds the global daily production of natural Acth, so the response of the aldosterone can be easily measured. In the same way as cortisol, aldosterone must double from a respectable basal value (about 20 ng/dl, it must refrain from salt for 24 hours and sit up to blood extraction).

  • In primary adrenal insufficiency, the basal value of aldosterone must be lower (less than 10 or slightly above) and rise up to less than double that value. If the aldosterone is doubled or more, based on a low basal value, a secondary hypoaldosteronism is probably suffered and together with the stimulation of cortisol can help support the diagnosis of secondary adrenal insufficiency.
  • In secondary adrenal insufficiency, aldosterone production can be multiplied by several factors based on low basal value. The deciplication of aldosterone in a stimulation test with Acth is possible (for example, 2 ng/dl rising to 20). [ 9 ] As in the stimulation of cortisol, many doctors lack sufficient knowledge when properly interpreting secondary hypoaldosteronism and thinks that this result is fantastic. As a general rule, what can be seen in case of secondary adrenal insufficiency is from a duplication to a quadruplication, based on a low basal value of aldosterone.

See also [ To edit ]

References [ To edit ]

  1. ↑ Dorin RI, Qualls CR, Crapo LM (2003). «Diagnosis of adrenal insufficiency» (PDF) . Ann. Internal. With. 139 (3): 194-204. PMID  12899587 .
  2. ↑ Elizabeth H. Holt, MD, PhD (2008). ACTH (cosyntropin) stimulation test .
  3. ↑ “Adrenal insufficiency diagnosis | Publication” , Dorin ri, qualls cr, crapping, ann. Intern. Med. Volume 139 Topic 3 pages 194–204 years
  4. ↑ K. Pagana, PhD, RN and T. PAGENA, MD, FACS. “Mosby’s Diagnostic and Laboratory Test Reference 2nd ed: Adrenocorticotropic hormone stimulation test . p. 17.
  5. ↑ K. Pagana, PhD, RN and T. PAGENA, MD, FACS. Mosby’s Diagnostic and Lab Test Reference 2nd ed: Aldosterone, Cortisol . pp. 29 and 260.
  6. ↑ Emily D. Szmuilowicz, Gail K. Adler, Jonathan S. Williams, Dina E.Green, Tham M. Yao, Paul N. Hopkins and Ellen W. Seely (2006). «Relationship between Aldosterone and Progesterone in the Human Menstrual Cycle» . Journal of Clinical Endocrinology & Metabolism 91 (10): 3981-3987. doi: 10.1210/jc.2006-1154 .
  7. ↑ a b K. Pagana, PhD, RN and T. PAGENA, MD, FACS. Mosby’s Diagnostic and Laboratory Test Reference 2nd ed.: Adrenocorticotropic hormone stimulation test . pp. 17-18.
  8. ↑ “Acth paper in the regulation and action of adrenocorticoids” Discovered Page 7 of
  9. ↑ “The vasoactive intestinal peptide stimulates adrenal aldosterone and corticosterone secretion” L.A. Cunningham y M.A. Holzwarth, endocrinology volumen 122, páininas 2090-2097, 1988