Cortisol: hormone functions, causes of increase and decrease
The content of the article:
- Functions of cortisol
- The rate of cortisol in the blood
- What does elevated cortisol mean?
- What does low cortisol mean?
- How to normalize cortisol levels
Cortisol (hydrocortisone) is a steroid hormone that is produced by the adrenal cortex. Refers to glucocorticoids, which received this name due to participation in glucose metabolism. In addition to carbohydrate metabolism, the hormone also affects the metabolism of proteins and lipids in the body, vascular tone, the functioning of the immune system, bone metabolism, the activity of the central nervous system and the formation of protective responses to stressful situations. Due to the latter function, cortisol is often referred to as the stress hormone.
The hormone cortisone is produced by the adrenal cortex
Cortisol is produced by ACTH, a pituitary hormone. The secretion of hydrocortisone increases in response to stress, infection, injury, and decreased blood sugar.
In the blood, the hormone cortisol is in two states: bound, in complex with α-globulin transcortin, and free. Free or unbound cortisol makes up about 8% of the total amount of the hormone in plasma and is a biologically active fraction.
Functions of cortisol
Cortisol affects many processes in the body:
- regulates carbohydrate, protein and lipid metabolism;
- is responsible for the formation of carbohydrate reserves in the body;
- maintains vascular tone, increases the vasoconstrictor effect of other hormones;
- controls the balance of sodium and water;
- increases diuresis;
- stimulates the activity of the heart muscle, increases the heart rate;
- improves the functioning of the central nervous system;
- suppresses humoral and cellular immunity, due to which it has an anti-inflammatory and hyposensitizing effect.
One of the most important functions of hydrocortisone is the regulation of carbohydrate metabolism. It stimulates gluconeogenesis and increases its level by 5-10 times. This effect of the hormone is due to two mechanisms:
- mobilizing amino acids from muscle tissue and transporting them to liver cells, where glucose is formed from them;
- an increase in the number of enzymes that convert amino acids into glucose.
The resulting glucose is deposited in the liver as glycogen.
Under the influence of the hormone, not only the synthesis of glucose increases, but also its consumption by cells decreases, which leads to an increase in blood sugar. If the blood sugar level rises above normal under the influence of glucocorticoids, this condition is called steroid diabetes.
The participation of hydrocortisone in lipid metabolism is associated with its ability to increase the breakdown of fats and reduce their formation, which leads to hyperlipidemia (elevated plasma lipids).
Cortisol got its name "stress hormone" due to its active participation in the formation of the body's response to emergency situations - trauma, hunger, physical and mental stress. This process also involves catecholamines (adrenaline, norepinephrine) and prolactin.
At high concentrations, hydrocortisone is capable of causing death of lymphocytes and involution of lymphoid tissue, as well as reducing the synthesis of inflammatory mediators, which leads to suppression of inflammatory reactions and the immune response. Due to its anti-inflammatory properties, the hormone and its synthetic analogues are used to treat allergic diseases, rheumatoid arthritis and a number of other pathologies.
The rate of cortisol in the blood
The level of hydrocortisone is one of the main indicators of the state of the adrenal glands. Its long-term change indicates diseases of the endocrine system. To determine the indicator, a laboratory determination of the level of cortisol in the blood and urine is used.
A blood test for cortisol is used to diagnose Itsenko-Cushing's disease, Addison's disease, and secondary adrenal insufficiency. Blood sampling is carried out in the morning, during 10-12 hours before the analysis it is necessary to avoid stressful situations and physical exertion, and also refrain from eating. Any drugs that can affect the level of hydrocortisone in the blood should be canceled two days before the test. If it is necessary to assess the daily dynamics of the level of cortisol, a second blood sampling is carried out in the period from 16 to 18 hours.
The test result depends on the time of blood sampling, normal indicators:
- morning (before 8 am) - 101.2-535.7 nmol / l;
- evening (after 4 pm) - 79.0–477.8 nmol / l.
Gender practically does not affect the result of the study, with the exception of pregnant women - they have a physiological increase in the level of the hormone by 2-5 times in the third trimester.
The rate of cortisol in children varies with age:
- children under one year old - 30-966 nmol / l;
- 1–5 years - 30–718 nmol / l;
- 5–10 years - 30–1049 nmol / l;
- 10-14 years old - 55-690 nmol / l;
- 14–18 years old - 28–856 nmol / L.
Urinalysis for cortisol is also of great diagnostic value. The level of free hydrocortisone in urine corresponds to the content of the free fraction of the hormone in the blood serum. This indicator does not depend on the time of day, its reference values do not differ in women and men and are in the range of 25–496 nmol / day.
Indications for a cortisol test are:
- osteoporosis;
- pigmentation of the skin;
- rapid weight loss or gain;
- change in the shape of the face;
- thinning of the arms and legs;
- diabetes;
- arterial hypertension with the ineffectiveness of standard drugs that lower blood pressure;
- the appearance of stretch marks (striae) on the skin;
- sexual dysfunction, infertility, amenorrhea or other menstrual irregularities in women;
- fragility of bones;
- depression, nervous state;
- sleep disorders.
What does elevated cortisol mean?
Elevated hydrocortisone levels may indicate the following:
- damage to the pituitary gland;
- dysfunction of the sex glands;
- diseases of the thyroid gland;
- severe obesity;
- uncompensated diabetes mellitus;
- malignant tumors of the adrenal glands, lungs, thymus, pancreas;
- Itsenko-Cushing's disease.
Itsenko-Cushing's disease (syndrome) is a neuroendocrine pathology associated with disruption of the hypothalamic-pituitary system. It is characterized by increased secretion of corticosteroids, more often develops in women 25-40 years old and manifests itself as specific obesity (fat is deposited in the face and trunk, and the limbs become thinner), excessive body hair growth, stretch marks and bone fragility.
The intake of certain medications can also lead to an increase in the level of the hormone: synthetic glucocorticoids, ACTH, estrogens, interferons, glucagon, opiates, vasopressin, and oral contraceptives.
The physiological long-term increase in hydrocortisone occurs only in pregnant women.
What does low cortisol mean?
The following disorders can lead to a decrease in the content of hydrocortisone in the blood:
- pituitary pathology;
- Addison's disease (chronic insufficiency of the adrenal cortex);
- congenital adrenal hyperplasia;
- hyperfunction of the thyroid gland;
- chronic liver diseases (hepatitis, cirrhosis);
- adrenogenital syndrome.
Also, a lowered hormone level can be the result of taking barbiturates, levodopa, magnesium sulfate, lithium preparations and synthetic corticosteroids.
A blood test for cortisol is indicated for suspected Itsenko-Cushing syndrome
How to normalize cortisol levels
In case of hormonal imbalance, it is important to establish its etiology.
If the deviation of the content of hydrocortisone from the norm is associated with a tumor of the adrenal glands, pituitary gland or other organs, anticancer treatment is performed. Surgical intervention for adrenal tumors is carried out by open or laparoscopic access, the entire affected adrenal gland is removed (adrenalectomy), and in the case of a malignant tumor, also nearby lymph nodes. After adrenalectomy, life-long hormone replacement therapy is prescribed.
If the concentration of cortisol is reduced due to a violation of its synthesis or secretion, hormone replacement therapy with corticosteroids is also indicated. Such an appointment is made only by a doctor.
With an increased level of hydrocortisone, drug therapy involves the use of blockers of the synthesis of steroid hormones, antihypertensive, hypoglycemic, diuretic drugs, cardiac glycosides, biostimulants and immunomodulators, antidepressants or sedatives, vitamins. Osteoporosis is treated according to indications. It is necessary to compensate for protein, water-salt and carbohydrate metabolism.
In addition, you should adjust your lifestyle and nutrition:
- give up caffeine;
- avoid drinking alcohol;
- drink enough water;
- reduce sugar intake;
- avoid stressful situations and emotional distress;
- give up excessive physical exertion.
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Anna Kozlova Medical journalist About the author
Education: Rostov State Medical University, specialty "General Medicine".
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