Growth Hormone: What is it? How is it controlled? Function and Consequences of High and Low Levels of this Hormone

It is produced by the pituitary gland . It has many functions, including the maintenance of normal body structure and metabolism.

Growth hormone is released into the bloodstream from the anterior pituitary gland. The pituitary gland also produces other hormones that have different functions of growth hormone.

Function

Growth hormone acts in many parts of the body to promote growth in children. Once the growth plates in the bones (epiphysis) have merged, the growth hormone does not increase the height.

In adults, it does not cause growth, but it helps maintain normal body structure and metabolism, which includes helping to keep blood glucose levels within established levels.

Growth hormone has been linked to a sense of well-being, specifically energy levels.

There is evidence that 30-50% of adults with growth hormone deficiency feel tired at a level that impairs their well-being. These adults can benefit from lifelong treatment with growth hormone.

Taking growth hormone as an adult will not result in an increase in height.

How is growth hormone controlled?

The release of growth hormone is not continuous, it is released in a number of “bursts” or pulses every three to five hours.

This release is controlled by two other hormones that are released from the hypothalamus: growth hormone-releasing hormone, which stimulates the pituitary gland to release growth hormone, and somatostatin , which inhibits that release.

Growth hormone levels are increased by sleep, stress , exercise and low blood glucose levels. They also increase around the time of puberty.

The release of growth hormone is reduced during pregnancy and if the brain detects high levels of growth hormone or insulin-like growth factors that are already in the blood.

What happens if there are high levels of growth hormone?

It is not surprising that too much growth hormone causes too much growth.

In adults, the hormone of excessive growth over a long period of time produces a condition known as acromegaly, in which patients have swollen hands and feet and altered facial features.

These patients also have organ enlargement and severe functional disorders, such as high blood pressure , diabetes and heart disease. More than 99% of cases are due to benign tumors of the pituitary gland, which produce growth hormone.

This condition is more common after middle age, when the growth is complete, so that the affected people do not get taller.

Very rarely, growth hormone levels can increase in children before they reach their final height, which can cause excessive growth of long bones, which makes the child abnormally tall. This is commonly known as gigantism

The overproduction of growth hormone is diagnosed by giving a sugary drink and measuring the level of growth hormone in the next few hours. Sugar should reduce the production of growth hormone.

What happens if there are low levels of growth hormone?

Very little growth hormone results in poor growth in children.

In adults, it causes a reduced sense of well-being, increased fat, increased risk of heart and heart disease, weak muscles and bones.

The condition may be present from birth, where the cause may be unknown, genetic or due to an injury to the pituitary gland (during development or at the time of birth).

Growth hormone deficiency can also develop in adults due to brain injury, a pituitary tumor, or damage to the pituitary gland (for example, after brain surgery or radiation therapy for cancer treatment).

The main treatment is to replace the growth hormone with injections, either once a day or several times a week.

In the past, treatment with growth hormone stopped at the end of growth. Now it is clear that growth hormone contributes to both bone mass and muscle mass by reaching the best possible level, and also reduces fat mass during development to an adult.