How does growth hormone work? | What we need to know

05.08.2024

What is growth hormone?

Human growth hormone, also known as somatotropin, is a hormone that is produced and secreted by the pituitary gland, a giant-sized gland located at the base of the brain. Growth hormone ensures the growth of various body parts and tissues during childhood.

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There are two forms of growth hormone: natural - produced by the brain (pituitary gland) and synthetic. Synthetic somatotropin is used to treat specific conditions.

What stimulates the release of growth hormone?

The release of growth hormone by the pituitary gland is impulsive (periodic) in nature, and the duration and intensity of its release depends on the time of day, age and gender. Growth hormone secretion is mainly controlled by hypothalamic hormones: growth hormone-stimulating factor – which enhances growth hormone secretion. Somatostatin - inhibits (blocks) the release of growth hormone.

Other endocrine hormones also affect growth hormone release:

Insulin-like growth factor-1 (IGF-1) blocks the release of growth hormone
Thyroxine, glucocorticoids and ghrelin – stimulate the release of growth hormone.

In healthy adults, the release of growth hormone is inhibited by hyperglycemia (high blood sugar), and its release is stimulated by: sleep, stress, physical activity, hypoglycemia (low blood sugar), and exposure to amino acids.

What is the function of growth hormone?

Stimulates growth - mainly in children
It affects metabolism – the process of converting food into energy.

Growth hormone ensures the growth of almost all tissues and organs. However, the most pronounced effect is on cartilage and bones, especially during adolescence. Osteoblasts (bone cells) and chondrocytes (cartilage cells) are stimulated by growth hormone to multiply and increase in size, which ensures the physical growth of the child. After puberty, the bone epiphyses (growth area in the barrel bones) no longer respond to growth hormone and the person does not grow in height, however, growth hormone is constantly needed to maintain normal tissue structure and adequate body metabolism.

Metabolism is a set of chemical processes in the body, through which food is converted into energy. Energy is necessary for the functioning of any cell.

Growth hormone activates insulin-like growth factor (IGF-1) and stimulates its effects on cells. IGF-1 is an insulin-like hormone that is involved in maintaining blood sugar levels and also regulates growth hormone production itself, through a negative feedback mechanism.

Normal levels of growth hormone are:

In men: 0.4-10 ng/ml or 18-44 ppm
In women: 2-14 ng/ml or 44-616 ppm/L
In children: 10-50 ng/ml or 440-2200 ppm/L

Effects of growth hormone treatment

A synthetic form of growth hormone was developed in 1985 and introduced to treat a variety of medical conditions in children and adults.

In children, growth hormone is used to treat growth retardation due to various causes, such as:

Turner's syndrome is a genetic defect of sex chromosomes that occurs in girls
Prader-Willi syndrome is a rare genetic disease characterized by decreased muscle tone, sex hormone deficiency, and constant hunger.
Chronic kidney diseases
Growth hormone deficiency
Children born with small weight and size for gestational age

Growth hormone in adults

The use of synthetic growth hormone in adults occurs during the following pathologies:

Short bowel syndrome – a condition in which nutrients cannot be absorbed from the intestine due to chronic diseases or intestinal resection.
Growth hormone deficiency as a result of pituitary tumors or its treatment.
Diseases that proceed with the loss of muscle mass (for example, during AIDS).

What happens when growth hormone levels are too low?

Growth hormone deficiency is usually associated with damage to the pituitary gland or a decrease in its function.

Growth hormone deficiency manifests differently in children and adults.

in adulthood Growth hormone deficiency may develop due to pituitary adenoma, or damage to the pituitary and/or hypothalamus. is developing

Tendency to fat accumulation
Increased risk of heart disease
Muscle and bone weakness
General weakness

in children The cause of growth hormone deficiency is often unknown and may be genetic or the result of acquired hypopituitarism. At this time, stunted growth, hair growth problems, and delayed puberty develop.

What happens when growth hormone levels are too high?

Growth hormone excess is a very rare condition and, like growth hormone deficiency, affects children and adults differently.

Growth hormone excess in adults usually begins after middle age, when growth in height is complete. Acromegaly develops. Such people have very large, swollen, thick limbs, an increase in the size of some organs - for example, the lower jaw and tongue, high blood pressure, type 2 diabetes, heart diseases. 99% of acromegaly cases are the result of pituitary adenomas or other benign tumors.

Excess production of growth hormone in children is very rare. Mizyzei is often undiagnosed, but in most cases it is the result of a pituitary adenoma. This condition causes gigantism – intense elongation of long bones and rapid growth in height. Without treatment, the height of the child may exceed 2 meters. Noteworthy is general weakness, headaches and delay in puberty.

When is a growth hormone laboratory test performed?

In the presence of the above-mentioned symptoms, it is necessary to determine the growth hormone in the blood serum. Since the release of growth hormone in the blood is of a peak nature, especially at night, the determination of the hormone in a single study is often insufficient. If necessary, growth hormone stimulation and suppression tests are used to diagnose hormone excess or deficiency. Insulin-like growth factor-1 is often prescribed along with growth hormone research.

Other forms of growth hormone

The injectable form of synthetic growth hormone is a medicinal product and can only be prescribed by a doctor. Taking growth hormone or its products as stimulants to increase muscle mass is not recommended.

Synthetic growth hormone in children is prescribed in the following conditions: