Cortisol studies

Cortisol is a hormone produced in the cortex of the adrenal glands. Its formation is regulated by adrenocorticotropic hormone (ACTH). It plays an important role in such processes as:

• glucose metabolism;
• regulation of the response of the immune system;
• maintaining blood vessels in tone;
• the body's reaction to stressful situations

Increased cortisol concentration leads to increased blood sugar, obesity, and increased blood pressure.

The very rhythm of the formation of this hormone is formed in babies aged 6-12 months and becomes stable after three years of life. When changing the time zone, it changes only after 15-20 days. In women, after childbirth or the end of taking contraceptives, the normalization of cortisol levels lasts up to 6 weeks.

Less than 5% of the total amount of cortisol substance is in the blood in a free state. It is the free form of the hormone that has the full biological effect on the body. Therefore, the total amount of the substance is not a reflection of the current clinical picture.

The concentration of the hormone is directly affected by the amount of transcortin. An increase in the amount of protein for transportation can be caused by diabetes of various types, hyperfunction of the thyroid gland, and other diseases. A decrease in concentration is due to the occurrence of kidney diseases, hypothyroidism, obesity and some other conditions.

In the laboratory, you can take a blood test for the level of the hormone cortisol. The result will be ready within 1-2 days. If necessary, you can make an appointment with an experienced endocrinologist for interpretation of indicators, appointment of additional examination and treatment.

Synonyms
Hydrocortisone, Compound F, Cortisol, Hydrocortisone.

Indications for the appointment of the analysis
Passing a blood test for cortisol is indicated in the following cases:

1. in the presence of symptoms of Itsenko-Cushing syndrome, including hypertension, myopathy, obesity, etc.;
2. growth retardation and overweight in children;
3. the need to diagnose adrenal gland insufficiency, suspicion of Addison's disease (manifested by specific skin pigmentation, weakness, fatigue, low blood pressure);
4. incidentaloma of the adrenal glands or suspicion of it.

In addition, the study is regularly conducted in the treatment of Addison's disease or Itsenko-Cushing's to monitor the effectiveness of therapy.

Description of the study
The study of the cortisol level is carried out by the method of competitive solid-phase chemiluminescent immunoenzymatic analysis. The patient needs to donate venous blood.

Preparation
It is recommended to donate venous blood on an empty stomach (eight to twelve hours before the procedure you should refuse to eat). Dinner the day before should be as light as possible, it is better not to eat fatty food. This is a necessary increase in the accuracy of laboratory research.

Before donating blood, it is important not to drink coffee, tea or juice for 1-2 hours. You can drink still water. It is necessary to refrain from smoking and drinking alcohol. It is preferable to avoid emotional excitement, as well as strong physical exertion, including rapid climbing of stairs, running for 48 hours before passing the analysis.

If you are taking medications on a regular basis (especially vitamin C, oral contraceptives, corticosteroids or other substances that can affect the concentration of cortisol), you should consult a doctor about preparing for the tests. Do not take androgens and estrogens 48 hours before the analysis. You should not conduct research on the day of instrumental examinations, physiotherapeutic procedures, massage, ultrasound, X-ray examinations. It is necessary to consult a doctor if other medical procedures were performed.

To clarify the diagnosis, it is recommended to take a cortisol test several times with an interval of 2-3 days under the same conditions. To do this, you need to choose one laboratory, come at approximately the same time. To determine the individual daily rhythm, it may be recommended to take several blood samples during the day.

Interpretation of the result
Units of measurement: nmol/l (nanomole per liter).

Reference values
The concentration of the hormone in serum depends on the time of day. The researchers determined that the maximum values are observed in the period of 8 am, and the minimum values are observed at 11 pm. In the evening, the concentration decreases significantly. If a person is healthy, the difference in the amount of cortisol between morning and afternoon is 50%, and if you compare morning and evening, the difference can be up to 350%.

The average norm for morning samples (from 6 to 10 a.m.) is 166-507 nmol/l, for evening samples (from 4 to 8 p.m.) - 73.8-291 nmol/l.

Analytical result
An excess of cortisol can be associated with one of the following pathologies:

• tumors of the pituitary gland or hypothalamus;
• neoplasms producing ACTH (can be located in the testicles, ovaries, bronchi);
• tumors of the adrenal glands or other organs that produce cortisol;
• hyperplasia of the adrenal cortex;
• adiposity;
• hyperthyroidism: excessive concentration of thyroid hormones in the blood.

A physiological increase in the concentration of the hormone is observed during pregnancy after stress (trauma, surgery), as well as against the background of alcohol abuse, smoking, the use of COCs and some diuretics.

A reduced cortisol level occurs against the background of:

1. tumors of the pituitary gland or hypothalamus;
2. neoplasms that produce ACTH (may be located in the testicles)
3. dysfunction of the adrenal cortex associated with inflammatory, autoimmune, tuberculous lesions;
4. androgenetic syndrome (congenital growth of the cortex of the adrenal glands);
5. hypothyroidism (decreased thyroid gland function).

Also, a decrease in the concentration of the hormone can be a consequence of long-term use of drugs based on corticosteroids.

Additional studies in case of deviation from the norm
If the patient has a change in the cortisol level, it is recommended to repeat the analysis several times, including at different times of the day to determine fluctuations in concentration. It is also necessary to assess the amount of the hormone in urine and saliva, to give blood for ACTH.

In most cases, an examination aimed at visualizing the adrenal glands and/or searching for a tumor of another location is performed.