ACTH (Adreno Corticotropic Hormone) Test

An ACTH test is considered a gold standard in diagnosing adrenal insufficiency, which is a life-threatening disorder. Early diagnosis and prompt hormonal replacement treatment can reduce mortality rates and improve the health of patients suffering from adrenal insufficiency. The test is highly recommended in patients who present with the following symptoms:

• Fatigue
• Lethargy
• Muscle weakness
• Increased thirst
• Loss of appetite and weight loss
• Frequent urination
• Hyperpigmentation
• Low blood sugar levels
• Low blood pressure
• Precocious puberty
  
  If you are tired of dieting and exercising and are not able to lose weight, then use myUpchar Ayurveda Medarodh Fat Burner Capsule, it has no side effects, order it today and avail the benefits.

It is a simple, painless and noninvasive procedure, and requires no special preparation. The patient may be asked to limit physical activities and eat a carbohydrate-rich diet 12-20 hours before the test. Fasting may be recommended for about 6 hours before the test.

Also, if the patient is on hydrocortisone, he or she is not allowed to take the medication before the test. The patient is given an injection of artificial ACTH, and blood samples are withdrawn at regular intervals from the vein to detect the concentration of serum cortisol. The test must be carried under medical supervision in patients having asthma.

ACTH test is a simple blood test wherein an experienced lab practitioner will swab the skin over a vein of your arm with an appropriate antiseptic and draw a blood sample with the help of a needle. It is necessary to withdraw a blood sample before the injection of artificial ACTH to note the initial concentration of cortisol in serum. Artificial ACTH is injected intramuscularly or intravenously then, and blood samples are withdrawn at 30- and 60-minute intervals for the short duration test.

In the long ACTH test, artificial ACTH is injected over two consecutive days as a depot preparation, and a blood sample is collected once before the test and then 5 hours after each dose. This test is mainly done to differentiate between primary and secondary adrenal failure.

Basal levels of cortisol are noted at 9 AM, considering the fluctuating levels of ACTH and cortisol during the day.

Normal results: Negative results of the ACTH test suggest a peak cortisol response of >550 nanomoles (nmol)/litre (L) after 30 and 60 minutes in the short duration test.

For the long ACTH test, the response of cortisol should rise above 1000 nmol/L at the end of the second day. After injecting ACTH, cortisol concentrations are expected to rise in healthy individuals.

In some laboratories, ACTH concentration may also be analysed, as the levels of cortisol may be depressed in some diseases despite a normal or elevated ACTH. Normal values of ACTH concentration fall in the range of 9-52 picograms/millilitre. Ranges of cortisol concentration may vary in different laboratories.

Abnormal results: Presence of lower than normal concentrations of cortisol indicate the presence of a health condition.

Low levels suggest that ACTH is not being able to stimulate the secretion of cortisol. Abnormally elevated concentrations of ACTH indicate Nelson’s syndrome, Cushing’s syndrome, Addison’s disease or ectopic ACTH-producing tumours.

ACTH concentration is decreased in secondary adrenocortical insufficiency and adrenal adenoma. Diseased conditions, such as tuberculosis, histoplasmosis or meningococcal sepsis, may damage the adrenal glands. Undetectable plasma ACTH levels suggest the presence of adrenal tumour.

Abnormal values of cortisol in an ACTH test suggest the following conditions:

• Adrenal insufficiency
• Low pituitary functioning
• Pituitary tumours
• Adrenal crisis

Conclusively, it can be said that the ACTH test is a gold standard to test adrenal insufficiency. However, there may be some secondary causes for dysfunctions in the adrenal gland, and hence differential diagnosis is required. The diagnosis can be confirmed using other tests, such as insulin-induced hypoglycaemic tests, whereas magnetic resonance imaging (MRI) and computerised tomography (CT) scans can help in case of adrenal tumours. Timely diagnosis with an ACTH test and prompt treatment can reduce the risk of adrenal crisis.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational perspective and is in no way a substitute for medical advice from a qualified doctor.