Growth Hormone

What is Growth Hormone?

The growth hormone is a protein hormone that consist about 190 amino acids and is secreted in the anterior pituitary glands by cells known as ‘somatotrophs’. This hormone plays a vital part in several complex physiologic processes including development and growth and is also one of the most abundant hormones that is secreted by the human body. The production of the growth hormone peaks at adolescence when the major growth of the body takes place. Growing children with too little of the hormone remain dwarfs while too much of hormone turns them into giants. The amount of the hormone that is secreted daily reduces with age, for example the hormone that is secreted in a 60 year can be five times less when compared to the hormone that is secreted in a 20 year old. As a result, the clinical studies have associated aging with the decline in the amount of growth hormone that is produced in the body.

Excess Production of Growth Hormone

Excessive secretion of the growth hormone can produce adverse effects which depends on the age when the excessive production takes place:

• Giantism: is the result when the hormone is produced excessively in young children or adolescents. It is a comparatively rare disorder and is usually a result of a tumor of somatotrophs.
• Acromegaly: is the result when the hormone is produced excessively in adults. The onset of this condition is very subtle and is visible after a couple of years. The common clinical symptoms of this condition are the overgrowth of the extremities in the body, swelling of the soft tissues and cardiac disease. This condition can also cause hyperglycemia.

Growth Hormone Tests

Tests to measure levels of growth hormones are not part of the general screenings. It is only required in cases where there are symptoms of growth hormone abnormalities or in cases where the pituitary function has to be evaluated. These tests are also performed on children who have undergone radiation treatment of the central nervous system or the whole body before stem cell transplants.

These tests help in identifying the excess or diminished production of the growth hormone thereby helping the doctor assess the severity of the condition. The two forms of tests available are the Growth Hormone Stimulation Test and the Growth Hormone Suppression tests.

The Growth Hormone Stimulation tests help in diagnosing hypopituitarism. Here, blood is drawn after the patient has fasted for about 12 hours. Once the blood has been drawn, the patient is given an intravenous solution of insulin and blood is again drawn at regular intervals to test if the pituitary gland was stimulated by the insulin to produce the expected levels of the growth hormone.

The Growth Hormone Suppression tests help in diagnosing hyperpituitarism and identifying the presence of tumors in the pituitary glands. Here, blood is drawn after the patient has fasted for about 12 hours. Once the blood has been drawn, the patient is given a standard glucose solution to drink and blood is again drawn at regular intervals to test if the pituitary gland is sufficiently suppressed by the dose of glucose.

Growth Hormone Therapy

In children, the deficiency of the growth hormone can easily be treated by using artificial growth hormone that is manufactured by recombinant DNA technology. It is usually injected into the subcutaneous tissue or the muscle so that it is passed to the blood. The benefits of the treatment are usually obvious almost immediately and the side effects are very rare. The benefits that will be noticed are progress in motor development, increased strength and reduction on body fat. Depending on the amount of deficiency, these replacements may be required throughout the lifetime of the individual.

In adults the growth hormone treatment provides numerous benefits like enhanced strength and energy along with an improvement in the bone density and the lipids level in the blood.

Further, growth hormone is also currently approved and sold for enhancing the milk production in dairy cattle. It has been established that the hormones increases the production of the milk in cows and also that this milk does not pose any kind of risk to human or animal health.