Growth Hormone (GH)

What is Growth Hormone?

Children undergo a series of changes and development until they reach adulthood. To have a normal growth, they need a hormone called the Growth Hormone (GH). This protein helps the proper linear bone growth all the way until puberty. Both kids and adults need this GH. It helps regulate the rate of energy production from food, as well as makes lipids, proteins and glucose. From another angle, this hormone regulates the production of red blood cells, as well as maintains a healthy muscle mass.

Produced by the pituitary glands, the growth hormone is released into the bloodstream in specific amounts throughout the day and night. For children, a deficiency in this hormone will lead to a very slow bone growth leading to short statures, while an excess GH can lead to an overgrowth of the bones, far beyond puberty. The majority of the times, high GH levels are caused by a tumor on the pituitary gland that may be surgically removed to reverse GH levels into normal levels.

Why take the Growth Hormone test?

The growth hormone test is a great tool to diagnose a growth hormone deficiency as well as diagnose any malfunctions of the pituitary gland. It is also used as a follow-up test to detect the effectiveness of a given treatment or to re-assess the functions of the pituitary glands. This test is also used to detect excess GH production as well as diagnose acromegaly and gigantism. It is a great tool to monitor the treatment of these two conditions.

If your child has signs of hypopituitarism, you need to get him or her tested for the growth hormone. Also, children who have signs of growth hormone deficiency need to get tested. These include having a slow growth rate in early childhood, looking shorter than other kids with the same age, reaching puberty at a delayed pace, and showing signs of delayed bone development. In adults, signs include feeling tired all the time, noticing that the muscles are weak, having changes in body fat composition, becoming socially isolated, and lacking ambition. Some signs of GH deficiency may include high cholesterol levels, lack of energy and stamina as well as joints pain and low bone density.

The Growth Hormone test is normally ordered with additional tests, like the insulin-like growth factor binding proteins-3 (IGFBP-3).

What causes the levels of Growth Hormone to rise?

Growth Hormones are released by the pituitary glands at specific times, which makes it useless to get tested randomly. Getting tested at the wrong time can make a big difference and lead to abnormal results when dismissing normal daily variations. This hormone is at its peak in the morning. Its levels will be high after a workout or a stressful event.

Some drugs and medications can lead to false results. These include amphetamines, arginine, dopamine, estrogens, glucagon, histamines, insulin, levodopa, methyldopa and nicotinic acid. They can lead to higher levels of Growth Hormone. From another angle, drugs like corticosteroids and phenothiazines can lower this hormone’s levels. High doses of Biotin can also affect the levels of Growth Hormone.

What do the Growth Hormone test results mean?

Normal values for the Growth Hormone are different for men and women. Values also vary with age. For men, normal values between the ages of 0 and 10 years are between 0.09 and 6.29 ng/mL; between the ages of 11 and 17 years, values are between 0.08 and 10.8 ng/mL; and finally, above 18 years, normal values are between 0.01 and 2.47 ng/mL.

For women, normal values are different for different age groups. Between 0 and 10 years, normal values are between 0.12 and 7.79 ng/mL. For girls that are between the ages of 11 and 17, normal GH values are between 0.12 and 8.05. Finally, for females who are older than 18 years, the reference range of the Growth Hormone us between 0.13 and 9.99 ng/mL.

Once the lab results are ready; they can be interpreted. Sometimes, further testing may be needed to have a proper diagnosis. If you have high levels of GH, you may have acromegaly, gigantism or a tumor. Acromegaly is a hormonal disorder caused by an overproduction of growth hormone by the pituitary gland. It is a condition affecting adults leading to an increase in size of the bones in the hands, feet and face. If this condition affects a child, it is called gigantism and can lead to an abnormal increase in height. This abnormal hormonal production has to be detected as early as possible to avoid serious health conditions.

If your GH levels are low; you may have possible dwarfism, slow growth or hypopituitarism. This latter is a rare condition where the pituitary gland produces insufficient amounts of growth hormones, or none.

Generally speaking, and due to the daily changes of this hormone, testing general growth hormone levels may not give enough information. In that case, s suppression or a stimulation test may be ordered. GH stimulation test is recommended to help the doctor have a better diagnosis of your condition. In this test, your blood sample is taken initially, followed by other blood samples taken over the next two hours. After the initial test, the patient is given a medication that will trigger the release of GH. When the GH levels do not seem to be stimulated following a GH stimulation test, and you are showing signs of deficiency, you will be diagnosed with GH deficiency that needs to be addressed properly. The GH suppression test is given to those who may show high levels of GH. It follows the same protocol of the GH stimulation test; however, a drinking solution containing glucose will be given after the initial blood sample to suppress the production of GH. The drink will have to be taken within 5 minutes to lead to more accurate results.

When the causes for abnormal levels of the Growth Hormone are identified, they can be addressed suitably. While some situations can be reversed, others can’t. For example, low GH levels in children with a stunted growth can be resolved if detected at the right time. High GH levels caused by malfunctions or tumors in the pituitary glands can be addressed by undergoing surgery, taking medications or radiation therapy. It is essential to detect abnormalities in GH levels as soon as possible to minimize its damages. Children with low levels, who are not diagnosed at the right time, will stay shorter than their friends. Also, those who have bone growth alterations, caused by acromegaly or gigantism, cannot have their condition reversed.

Growth Hormones and Athletes

While we, humans, are capable of producing the growth hormone, athletes have an affinity to introduce it to their system in its synthetic form. This hormone is among the anabolic agents that are prohibited in the world of athletes and professional sports competition. Growth Hormone helps building speed, strength and speeding recovery; so, to keep games fair, athletes, whether they are elite, junior or masters-level are prohibited from using it unless they have an approved Therapeutic Use Exemption.

Only a few medical conditions may lead to the legal prescription of growth hormone. These include Prader-Willi syndrome, Chronic Kidney disease, Turney syndrome and idiopathic short stature. It is also indicated to treat growth failure in kids that were born very small in size and were not being able to catch up. Adults get prescribed this hormone, in its synthetic form, to treat a pituitary disease, or following a radiation therapy or trauma. Growth Hormone replacement therapy is advised to individuals who are HIV positive or have AIDS, to prevent muscle wasting and maintain a healthy body weight. If chosen as a treatment, your healthcare provider needs to be cautious as to when and how this hormone can be given: outweighing the benefits is essential.

While some use growth hormone, as a dietary supplement; many health risks have been associated with it. These include high brain blood pressure, damages to the retina and vision of diabetic individuals, a faster advance of scoliosis, hypothyroidism, pancreatitis, generalized pain, and damages to the growth plates of kids’ femur. A prolonged use can inhibit the natural production of growth hormones, to the point of damaging its normal pathways.

Where can I get a Growth Hormone test near me?

Please use our Lab Locator to find find a convenient testing location.

Reviewed By: Dr. Kurt Kloss, MD
Last Reviewed Date: Oct 24, 2019