Dexamethasone is a powerful corticosteroid used to suppress inflammatory reactions. This substance affects a specific system of the human body. It controls reactions to situations, and in medical terminology is referred to as the HPA (hypothalamic-pituitary-adrenal). To study its functioning, a dexamethasone test is prescribed.
When is it necessary to test with dexamethasone?
The dexamethasone test is used in medical practice Often. This research method is used to diagnose pathological processes V various systems body.
- This analysis allows you to identify the slightest disturbance in the production of the stress hormone or cortisol in initial stage, and establish the causes of adrenal dysfunction.
- The results of the study are necessary for differentiating endocrinological diseases and identifying neoplasms of various etiologies.
- Often the test is prescribed when affective disorders. It allows you to establish the integrity of the HPA axis.
- In gynecology, such an examination is carried out when clear signs hyperandrogenism and infertility.
- Practicing psychiatrists use a test with dexamethasone to identify endogenous.
A test with dexamethasone is prescribed when pathological conditions caused by abnormal cortisol levels. They appear as:
- Dysplastic
- Myasthenia gravis
- Osteoporosis
- Hypertension
- Hirsutism in women
- Violations menstrual cycle
- Chronic thrush
- Amenorrhea
- Urolithiasis
- Chronic pyelonephritis
- Decreased libido in men and women
- Erectile dysfunction
- Purple stretch marks on the abdomen more than 1 cm wide
- Trophic ulcers and pustular skin lesions
- Decreased immune defense
- Insulin sensitivity disorders
- Chronic fatigue
- Fatigue
- Depressed
- Sleep disorders
- Systematic appearance of a euphoric state
Also, the reason for testing with dexamethasone may be slow healing of wounds and minor scratches, the unreasonable appearance of bruises on the body and sudden changes in weight.
Signs of cortisol imbalance in the body appear individually or in combination.
A dexamethasone test is prescribed by a gynecologist, endocrinologist or urologist. It is usually recommended to take the test when comprehensive examination after a physical examination.
Venous blood is used for the study. The collection of biomaterial is carried out in special medical laboratories either in inpatient conditions medical institutions.
To reduce the percentage of error in the result, it is necessary to adhere to the manipulation technique:
- Blood is drawn from a vein in the morning or at the time prescribed by the doctor.
- The biomaterial is placed in a sterile tube
- For blood preservation, it is permissible to use sterile tubes with gel
It is important that all sterility rules are observed in the laboratory. Medical staff should use disposable Consumables and sterile gloves.
To ensure maximum test results the right doctors It is recommended to carry out preliminary preparation. To do this you need:
- Donate blood on an empty stomach
- 8-10 hours before consuming heavy fatty foods
- Limit emotional stress in 12 hours
- Stop hormone therapy 2 days before the test
- For 1-2 limit physical activity and don't go to the gym
- Do not smoke 2-3 hours before the pick-up
- Stop drinking alcohol and painkillers one day before
Blood donation is carried out in calm state. To do this, you should sit or lie down for 15-20 minutes before the manipulation.
The following factors can distort the analysis results:
- Long-term use of potent medications
- Abuse
- Taking hormonal medications
- Obesity
- Diabetes mellitus of any type
- Diencephalic syndrome
- Chronic hepatitis
- Pregnancy
If one or more factors are present, the condition is corrected before the test and a dexamethasone test may be prescribed several times.
Dexamethasone test: protocol and explanation
To diagnose pathology, two main types of dexamethasone test are used:
- Small
- Big
Each type of test is performed in several ways. In diagnostics there is frequent use of:
- Classic
- Short
Small protocol classic test with dexamethasone:
- On the first day, in the morning at 8.00 am, blood is taken to determine the initial cortisol level.
- For two days, every 6 hours, dexamethasone in 0.5 m tablets is taken orally. A single dose is 1 pc.
- On the third day at 8 o'clock in the morning, blood is donated to determine the concentration.
- The accuracy of the method is within 98-99%.
- In the short version, a blood test is taken at 8.00 to determine the baseline cortisol level. On the same day at 11:00 pm, two 0.5 mg dexamethasone tablets are taken orally. The next morning, blood is donated again for cortisol concentration.
- Accuracy this method 95-96%.
- The decoding of the indicators is the same for the two options. If the level of cortisol after dexamethasone decreases by half, this is considered normal or is a sign of functional hypercortisolism. With such indicators, the sample is defined as positive.
- The test is considered negative if there are no changes in cortisone levels or if they increase. This result is a sign of endogenous hypercortisolism.
- A large test with dexamethasone is performed if the small test is negative. Using this analysis, the disease is differentiated from Itsenko Cushing's syndrome.
IN classical way When performing this test, a certain sequence is followed:
- On the first day at 8 a.m., blood is donated to determine baseline cortisol.
- For two days, every 6 hours, take 4 tablets of dexamethasone at a dosage of 0.5 mg. Single dosage 2 mg.
- On the third day, in the morning at 8 o’clock, the cortisol level is analyzed again.
- The test accuracy is at least 98%.
- In the short method, on the first day in the morning at 8 o’clock, a blood test is taken for basic cortisol. At 23.00, 8 mg of dexamethasone is taken in one dose. These are 16 tablets of 0.5 mg. At 8.00, blood is again donated for cortisol concentration.
- The sensitivity of the test is within 96%.
Decryption for two methods:
A decrease in the concentration of free cortisol by half or more is considered a sign of Itsenko's Cushing's disease. IN in this case the test is considered positive. If the indicators do not change, the sample is defined as negative.
While watching the video you will learn about food.
The dexamethasone test is an accessible test and allows you to detect changes in cortisol levels by early stage. This will allow doctors to quickly diagnose accurate diagnosis and select the most effective therapeutic method.
Dexamethasone is a powerful corticosteroid. It is many times more powerful than its analogues: hydrocortisone, prednisolone, and predisalone. Dexamethasone, like any corticosteroid, is used when it is necessary to suppress the inflammatory response.
Dexamethasone affects the functioning of a very specific system in the body. This system controls the stress response and is called hypothalamic-pituitary-adrenal or HPA. When Dexamethasone is introduced into the body, the production of the stress hormone (cortisol) decreases and the production of anti-inflammatory substances increases. This useful aspect is used in this suppression test.
Reasons for taking the test
The Dexamethasone Suppression Test is a test used to see if the body is oversecreting adrenal hormones. If these hormones are produced more than normal, then this is a disease called "Cushing's syndrome". Usually it indicates the presence of some kind of tumor. The test is also used to test the integrity of the HPA axis in mood disorders.
Preparation
There is no special preparation for the test, but the patient is usually advised not to take any painkillers. If the suppression test is to be performed at night, the person will be advised to prepare to spend the night in medical center. If the suppression test results show low level ACTH (adrenocorticotropic hormone) and high cortisol levels, which were not affected even by the administered Dexamethasone, then it is quite possible that the patient has an adrenal tumor. Normal or elevated ACTH levels with high level cortisol, which does not decrease even despite large doses of Dexamethasone, indicates that there is a tumor in another organ. If the ACTH level is normal or elevated, and the cortisol level is high and can only be reduced with large doses of Dexamethasone, then the patient has a pituitary tumor. The normal result is a decrease in cortisol levels with the administration of small doses of Dexamethasone.
Procedure
Before the test begins, a Dexamethasone injection is given. A blood sample is then taken and tested for cortisol and ACTH levels.
The large Dexamethasone suppression test is performed to test the immediate response of drug administration on the HPA axis. Typically, the HPA axis uses a negative mechanism feedback to control hormone levels. The hypothalamus, responding to a stressful situation, will stimulate the pituitary gland to secrete the hormone. ACTH then stimulates the adrenal glands to immediately synthesize cortisol from cholesterol. In addition, the levels of norepinephrine and cortisol increase. After finishing stressful situation, the brain suppresses further production of ACTH, which restores peace of mind.
Dexamethasone Suppression Test (DST) Dexamethasone is synthetic glucocorticoid long acting with a long half-life.
Approximately 1 mg of dexamethasone is equivalent to 25 mg of cortisol. The dexamethasone suppression test is used to confirm the diagnosis of depression with melancholia or endogenous depression. Procedure. The patient is administered 1 mg of dexamethasone orally at 23:00; Plasma cortisol measurements are taken at 8 a.m., as well as at 4 and 11 p.m.
If the plasma cortisol level exceeds 5 mg/dL, this indicates a lack of suppression and is considered a pathological or positive reaction. Suppression of cortisol indicates that the hypothalamic-adrenal-pituitary axis is functioning normally. As early as 1930, it was shown that dysfunction of these systems is caused by stress.
TPD can be used to monitor the effectiveness of treatment. Normalization of this test, however, does not mean that antidepressant treatment can be stopped, since. TPD sometimes normalizes before it disappears Clinical signs depression. There is evidence that patients who respond positively to TPD, especially those with cortisol levels greater than 10 mg/dL, typically respond well to somatic therapies such as electroconvulsive therapy (ECT) or cyclic antidepressant therapy. However, due to the different sensitivity and specificity of TPD, sometimes false results, severe weight loss (eating disorders, anorexia), alcohol abuse.
False negative results can be caused by hypofunction of the pituitary gland, Addison's disease, long-term therapy with synthetic steroids, indomethacin, large doses of cyproheptidine and large doses of benzodiazepines.
A dexamethasone test is needed to detect elevated levels of cortisol in a person’s blood. Not many people know what dexamethasone is - it is a hormone produced by the adrenal cortex, it should be noted that it is the strongest and most powerful among them.
This test also allows us to identify various hormonal disorders and establish the main reason why the fair sex may experience irregular menstrual cycles. In addition, the dexamethasone test can reveal pathological disorders in the female reproductive system and clearly identify the reasons for the appearance of traits that are inherent only in representatives of the stronger half of humanity.
A dexamethasone test is prescribed to patients with increased levels of male hormone production. Only such a procedure can identify the source of the violation and establish its nature. It has been scientifically proven that hormonal tests are the most effective and accurate diagnostic procedures. That is why at the slightest hormonal imbalance any representative of the fair sex should immediately contact a medical facility and make an appointment with a specialist. Only a doctor, after the results of an appropriate examination, will be able to prescribe the necessary test to the patient.
As previously mentioned, a test with dexamethasone is prescribed only to those patients in whom it is necessary to identify the main cause of the manifestation male characteristics, such as testosterone. Such signs usually occur due to excessive production of male hormones in female body. It should be noted that depending on the dose, the sample may be:
- A small dexamethasone test can be performed in a specialized medical institution two methods - classic and shortened. The first method is that the patient takes blood on the first day at eight in the morning, which is necessary to determine the level of cortisol. Then, over the next two days, the patient should take one dexamethasone tablet every six hours. On the third day, at exactly eight in the morning, a reanalysis. This is a fairly sensitive method, because its result is 97-100%. The second method is that on the first day at eight in the morning, blood is also taken from the patient to determine the level of free cortisol. At eleven o'clock in the evening of the same day, the patient must take two dexamethasone tablets at once, and the next day be tested again. The sensitivity of this method will be slightly lower and will be approximately 95%, however, you will be able to get the result faster. As for the results, their interpretation will be the same for both options. So, for example, if the results of the study reveal that cortisol has dropped by half, then the test is positive;
- A large dexamethasone test is prescribed by a specialist, provided that the small one shows a negative result. In this case, a large dose of dexamethasone is used during the study. To carry out such a test, two methods are also used - classic and shortened. The first method is practically no different from that used for a small dexamethasone test, the only difference is in the number of tablets - the patient takes four every six hours, after which he is tested again. A shortened version of the large dexamethasone test involves taking sixteen tablets at a time. Samples are interpreted in the same way, regardless of the method. If the results of the study reveal a decrease in cortisol by fifty percent from the original level, the test will be considered positive. If no changes are noted, the sample will be considered negative.
The differences between these samples lie not only in the dosage, but also in the process itself. A small test, or also called a short test, allows specialists to distinguish exogenous hypercortisolism from endogenous one. As a rule, exogenous refers to too much intake of various medicines and increase normal level cortisol.
This hormone can increase in human body with obesity, excessive consumption of alcoholic beverages, diabetes and pregnancy. Usually, when the underlying cause is eliminated, the hormone returns to its normal state and no longer bothers the person.
Preparatory stages
No special preparation is required from the patient to determine the level of the hormone in the blood; experts recommend that their patients refrain from taking any painkillers the day before the test. The dexamethasone test involves taking the drug strictly according to the regimen, which, as a rule, can only be prescribed by the treating doctor.
In addition, the specialist must strictly monitor compliance with the prescribed dosage and time intervals. Therefore, experimenting with the dosage and breaking the rules will not work in any case. Unauthorized prescription of the drug will not lead to anything good, the patient must understand this.
It is not necessary to follow any diet before donating blood and identifying hormone levels. The only limitation is that it is not recommended to eat or drink water approximately ten hours before the test. Also, be sure to tell your doctor about any medicines that you take on this moment– this is very important, since many of them can have a direct impact on the test results.
Otherwise, you will have to take the test again. It is likely that after announcing the medications you are taking, the doctor will decide to prohibit some of them in order to achieve the most accurate result. If the test is performed at night, the patient will be warned that they will have to spend the night at the medical center.
Hormonal tests allow you to obtain the most accurate results, which may indicate a particular disorder associated with the normal production of the hormone. As a result of such a test, a specialist can detect the following diseases or deviations:
- Adrenal tumor;
- Ovarian tumor;
- Adrenal hyperplasia;
- Cyst;
- Pituitary tumor;
- Chorionepithelioma of the ovary.
In fact this is far from full list diseases that can be identified as a result of the study. It is also worth noting that the dexamethasone test is simply irreplaceable if a specialist needs to confirm the presence of Cushing’s syndrome and hypercortisolemia. Such studies are often practiced by specialists in the field of gynecology, thanks to them it becomes possible to identify even the most subtle deviations in the secretion of a particular hormone.
According to the results obtained, the specialist can determine the cause of the absence of the menstrual cycle, excessive production of male hormones, infertility and various tumors. All procedures are absolutely painless and do not cause any discomfort, so do not be afraid.
What can interfere with the test?
There are certain reasons the presence of which can affect the test results, these include: pregnancy, obesity, diabetes, great loss weight, sudden cessation of alcohol abuse, rapid metabolism, and serious injuries.
As a rule, if such reasons are discovered, the specialist decides to cancel the study; the patient must understand that in this case it will simply be pointless, and it will not be possible to establish the correct level of the hormone. It is possible that the patient will be offered an alternative option, but please note that this will not give the most accurate and effective results.
Many patients who are prescribed a test to detect levels of a hormone called cortisol by a specialist wonder what complications or risks there may be after the procedure. No serious complications were observed. Possible risk may only be associated with the procedure of drawing blood from a vein, which will result in a small bruise at the puncture site.
In some cases, inflammation of the vein has been observed, but warm compresses applied to the arm several times a day quickly relieve patients from such incidents. Also, if at the time of the test you were taking or are taking any medications that thin the blood, then you may experience slight bleeding at the puncture site.
Remember that if you detect any hormonal abnormalities, you don’t need to put off your visit to the doctor, don’t be lazy, but contact us right away qualified help. You cannot solve such problems on your own, otherwise everything could be much more serious later. It is much easier to detect and eliminate any disease at the initial stage than later. In addition, the procedure for identifying the level of a hormone called cortisol is quite simple, painless and will not take much of your time.
Dexamethasone test used to detect hypercortisolism ( higher level cortisol in the blood). In this article you will learn how and when a dexamethasone test is performed.
Large doses include non-physiological doses of the drug, i.e. those that exceed the replacement dose by several times. This response to dexamethasone is dose-dependent, that is, it depends on the dose administered. This is what they are based on different variants dexamethasone test.
How is the dexamethasone test performed?
Dexamethasone test depending on the dose it may be:
- Small dexamethasone test.
- Large dexamethasone test.
Small dexamethasone test
A small dexamethasone test allows one to distinguish exogenous hypercortisolism from endogenous one.
Exogenous hypercortisolism includes:
- Excessive intake of glucocorticoid drugs in various diseases
- Increased cortisol levels with
- obesity
- alcoholism
- false results
- diencephalic syndrome
- chronic hepatitis and liver cirrhosis
- pregnancy
This increase in cortisol in the blood (in addition to excess intake of drugs) is also called functional hypercortisolism. Cortisol levels decrease when the cause is eliminated.
The small one is carried out as follows. There are several options for conducting the test: classic and shortened.
Classic version T.
On the first day at 8:00 a.m., blood is drawn to determine baseline cortisol levels. Then, 0.5 mg (1 tablet) of dexamethasone is taken every 6 hours for 48 hours. On the third day in the morning at 8:00 am, the level of free cortisol is determined again. The sensitivity of the method is 97-100%.
Short version.
On the first day at 8:00 - blood sampling for the initial level of free cortisol. At 23:00 on the same day, the patient takes 1 mg (2 tablets) of dexamethasone. On the second day in the morning at 8:00, blood is taken again to determine free cortisol. The sensitivity of the method is slightly lower - 95%.
Interpretation of results.
The interpretation of the results is the same for both options. Normally and with functional hypercortisolism, cortisol levels decrease by more than 2 times. In this case, the sample is considered positive.
With endogenous hypercortisolism, the test is negative, because there are foci of autonomous hormone secretion that are not affected by the administered dexamethasone at this dose.
Large dexamethasone test
When the endogenous cause of elevated cortisol levels in the blood is established, i.e. small sample turned out to be negative, a large dexamethasone test is performed. This test will allow you to distinguish between the disease and Cushing's syndrome. Read more about this syndrome. A large dose of dexamethasone is used here. This sample also has 2 options: classic and shortened.
Classic version.
On the first day at 8:00 am the initial level of free cortisol in the blood is determined. Then, for 48 hours, 2 mg (4 tablets) of dexamethasone is taken every 6 hours. On the third day at 8:00 am, blood samples are taken again for free cortisol.
Shortened version T.
On the first day at 8:00, blood is also taken and the initial level of free cortisol is determined. At 23:00 on the same day, the patient takes 8 mg (16 tablets) of dexamethasone. On the second day at 8:00 - repeated blood sampling for free cortisol.
Interpretation of results.
The interpretation of the sample is the same in both cases.
Upon admission large dose dexamethasone in Itsenko's Cushing's disease, the level of free cortisol decreases by 50% or more from the original level. The test is considered positive. Read about Itsenko Cushing's disease.
With adrenal forms of Itsenko Cushing, as well as with a decrease, this does not occur and the test remains negative.
Thus, it is an excellent tool in the diagnosis of diseases that occur with symptoms of hypercortisolism.
With warmth and care, endocrinologist Dilyara Lebedeva
