About Adult Growth Hormone Deficiency

What is growth hormone?

Growth hormone (often referred to as hGH, or simply GH) is a protein that, among other things, tells a child's body to grow. It is produced by the pituitary gland (an organ about the size of a pea, located at the base of the brain) and released into the bloodstream.

What does growth hormone do?

As its name suggests, growth hormone is the chief hormone responsible for growth. In children, it stimulates the development of muscles and bones, and also helps regulate metabolism.

In adults, growth hormone is essential to the maintenance of healthy body composition and metabolism. Throughout adulthood, growth hormone plays an important role in maintaining an improved ratio of body fat to lean mass, "bad" to "good" cholesterol levels, and proper bone mineral density.

What is AGHD?

AGHD occurs when the pituitary gland does not secrete enough growth hormone. In adult patients, pituitary disease may occur as a result of pituitary tumors, pituitary surgery, radiation therapy, or head injury—impacting the gland's ability to produce sufficient growth hormone.

Are there two types of AGHD?

Generally, adults with growth hormone deficiency can be divided into 2 groups: those who were growth hormone deficient as children and continue to be so as adults (childhood-onset patients) and adults with pituitary disease who became growth hormone deficient as adults (adult-onset patients).

How is AGHD diagnosed?

Your healthcare provider will perform diagnostic tests if he or she feels you may be at risk for growth hormone deficiency. In order to be diagnosed with adult growth hormone deficiency you must meet either of the following two criteria:

First, you must be officially diagnosed with AGHD based on a smaller-than-normal response to a growth hormone stimulation test.

If you have adult-onset growth hormone deficiency, you must have a deficiency of growth hormone either alone, or in combination with deficiencies in other hormones resulting from disease, surgery, radiation therapy, or trauma.

If your growth hormone deficiency began in childhood, the diagnosis of your childhood condition will need to be confirmed prior to beginning therapy as an adult.

What pituitary problems cause adult-onset growth hormone deficiency?

In adults, growth hormone deficiency may often result when the pituitary gland becomes diseased or damaged. Particular tumors of the pituitary gland (pituitary adenomas), physical injury to the brain (hemorrhage, trauma, surgery), or radiation therapy can all injure the pituitary gland severely enough to cause growth hormone deficiency.

In the U.S. approximately 50,000 adults have growth hormone deficiency and 6,000 new cases of AGHD are diagnosed each year. Children who receive growth hormone therapy may need to continue with the therapy into adulthood if AGHD is confirmed.

When can I expect to see results from my Nutropin therapy?

It may be a number of months until you see the results of your Nutropin therapy. The changes may be so gradual at first that they are difficult to notice, but try not to get discouraged. Take your replacement therapy when and how your healthcare provider instructs. If you take it every day and don't miss doses, you can improve the likelihood of positive results.

I am taking other hormone medicines—why do I need to take Nutropin therapy?

Depending on the cause of AGHD, many patients need to take other hormones. GH is produced by the pituitary gland—a small gland located at the base of the brain. This small gland is actually responsible for releasing and controlling many hormones in our bodies. Each of these hormones is released in tiny amounts into the blood stream. Once in the blood, each hormone travels to a different part of the body to perform a specific function. GH released from the pituitary is important for growth, body composition, lipid metabolism, and strength. Each of the other hormones released from the pituitary are important for other reasons—from salt and water regulation to helping our bodies deal with stress. Nutropin cannot replace the function of these other hormones. Remember to tell your healthcare provider about all of the medications that you take, including nonprescription medications and vitamins.

Why did my healthcare provider order a DEXA scan before I started taking Nutropin therapy?

Dual-energy x-ray absorptiometry (DEXA) is a special kind of x-ray that uses a very low amount of radiation. It is the method that healthcare providers use to determine body composition or the proportion of your body that is made up of fat. DEXA is also considered the "gold standard" for measuring bone density. Patients with AGHD may experience changes in decreased bone density and body composition. By taking a DEXA scan before you begin treatment, your healthcare provider will have a baseline measurement of your bone density and the composition of your body.

How is the effectiveness of Nutropin therapy measured?

For adults on Nutropin therapy, success may be gauged using measures such as assessments of body fat and muscle mass, spine bone mineral density (in certain patients), and ratio of LDL to HDL cholesterol.

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