Growth Hormone Deficiency in Adults can be an extremely difficult process to diagnose. Often symptoms build slowly as people age. Patients as well as physicians are challenged to try and sort out what is normal aging and what is actually a serious health issue, such as growth hormone deficiency.
At MAGIC, we have many adults who have lived through this challenge. Some were growth hormone deficient as children and came to understand their health issues were repeating again in adulthood. Others had tumors or other conditions which led to growth hormone deficiency. Still others had no medical history of problems and faced years of struggle to get help.
We hope our information, Annual Educational Convention and social online-chat area's help those still searching for answers, as well as giving a safe place for those already diagnosed to share.
Why do adults need Growth Hormone?
Growth hormone maintains muscle, bone and fat tissues in healthy balance. Without growth hormone, these tissues get out of balance. Deficiency of growth hormone in children is easy to recognize. Children with low levels of growth hormone grow poorly and remain short. In adults, growth hormone deficiency is not easy to spot since adults have achieved adult height and have used their bones, thereby preventing further growth. The deficiency of growth hormone in adults can be appreciated by looking at body composition. Since growth hormone maintains a proper amount of fat, muscle and bone, these important parts of our bodies are not nurtured properly and change in an unhealthy direction. With this deficiency, fat is deposited more easily, especially around the middle of the abdomen, what doctors call visceral or abdominal fat. Since growth hormone affects muscles, they also change for the worse, which means there is less muscle and less ability to exercise. Bones, too, participate in the deficiency by becoming weaker (but not shorter). We call this weakening osteoporosis. This combination of more fat, less muscle and less bone structure represents the body composition changes as the result of growth hormone deficiency in adults.
Adults experience an additional problem with growth hormone deficiency. Since growth hormone controls fat metabolism, adults with growth hormone deficiency will have a change in their blood fats referred to as cholesterol. These changes result in a higher overall cholesterol level in blood, which is undesirable. The “good” cholesterol level to be as high as possible. This good cholesterol (also referred to as HDL cholesterol) changes to a lower level as the result of growth hormone deficiency, which is the opposite of what we want to be healthy.
Most children who develop growth hormone deficiency do so because the hypothalamus, for unknown reasons, fails to function and does not stimulate the pituitary gland to release growth hormone. There is not a visible cause of pituitary injury in most children with growth hormone deficiency. Adults, however, who develop growth hormone deficiency usually do so because of some damage to the pituitary gland. This damage results in an inability to make growth hormone in sufficient quantities. The most common cause of pituitary damage in adults is a pituitary tumor. Either the tumor itself, or surgery to remove the tumor or radiation therapy of the tumor, can result in damage to the pituitary and an inability to produce growth hormone. Less commonly, pituitary underproduction of growth hormone may result from head injury or irradiation to the head for treatment of a brain tumor. Some adults may also have under active thypothalamic drive (activity) as a cause of growth hormone deficiency similar to the most common reason for children to develop low growth hormone, but this is rare.
Adults who develop growth hormone deficiency often do not feel their usual selves. Most notice a decrease in their energy level and endurance for exercise. Some may avoid social contact or avoid meeting with or talking to their friends. Others will have deficient interest in sexual activity. Other people with growth hormone deficiency think they feel normal, but do not remember the way they felt before they developed the deficiency. People may feel a dramatic improvement only after growth hormone therapy is started.
If you are diagnosed with Adult Growth Hormone Deficiency because of low or absent growth hormone (GH) secretion levels you may have been experiencing a number of different physical and emotional symptoms. Feeling tired, listless, easily fatigued, and having a lack of motivation are often reported by patients. Some individuals report feeling anxious, irritable, losing interest in sex, and a pervasive sense of gloom and pessimism about their lives. Because of these effects, persons with Adult Growth Hormone Deficiency may tend to avoid contact with others, show signs of stress in their marriage, and experience a gradual decrease in their productivity at work. Quality of life begins to decline and the affected individual often suffers in silence.
Although we refer to it as "growth" hormone, GH actually has many functions other than helping growth to occur. GH is a powerful brain hormone that is believed to play an important role in stimulating and controlling areas of the brain that regulate moods and emotions. Certain chemicals in the brain, called neurotransmitters are dependent on the effects of GH to help them carry their messages between brain centers. If GH is not available, these functions may not occur appropriately and the result can be uncontrolled changes in psychological functioning. Individuals may feel anxious, depressed or worried for no apparent reason when this happens, and this may cause changes in behavior or decline in social functioning.
How GH can cause Moods and Emotions to Change
Negative and sad feeling may dominate your mood, and positive or joyful feelings can be dampened. An affected individual could feel unable to enjoy life and lack the motivation to make change in their circumstance. It is important to remember that these emotional changes are not usually directly related to actual life events and therefore are difficult to anticipate. Research has shown that many GHD patients suffer these symptoms privately and do not report them to their doctors. This is unfortunate because there are several treatments available to help manage these problems.
Your doctor will choose a test to prove growth hormone deficiency. Since growth hormone in blood can often be low in normal individuals, a low level in blood does not prove growth hormone deficiency. Your doctor will choose a stimulation test that will cause growth hormone to be released by your pituitary gland into your bloodstream, by measuring your blood at intervals after the stimulation has been given, your responses to the stimulus can be obtained. In normal individuals there is a rise in blood growth hormone after a stimulus. In deficient individuals there is not rise or an insufficient rise, which will prove you are growth hormone deficient. A few of the growth hormone stimulants (growth hormone stimulation tests) include arginine, L-dopa, clonidine or insulin. Your doctor will choose one of these that best fits your lifestyle.
You have been referred to an endocrinologist, a doctor who specializes in the diagnosis and treatment of adult disorders caused by or affecting the endocrine glands. Endocrine glands release chemicals into the blood, which tell parts of the body to do certain jobs. These chemicals are referred to as hormones. Endocrine disorders are those that involve deficiencies or excesses of hormones. Therefore, growth hormone deficiency qualifies as an endocrine disorder. A growth hormone deficiency exists when there is not enough growth hormone in the body. In order for your doctor to make an accurate diagnosis, some testing may be necessary. This section was written to help you and your family understand the evaluation process of hormone deficiencies for adults.
Control of Hormones/ Hormone Deficiency
The hypothalamus controls the pituitary gland; both are located in the brain. The pituitary gland releases or controls many hormones in the body. The hormones are released in very small amounts into the bloodstream and then travel to parts of the body (referred to as target organs) to perform a specific job. These hormones control many of the body's functions, which are the following: Thyroid Stimulating Hormone (TSH) turns the thyroid gland "on" in order to control your metabolism. Adrenocorticotrophic hormone (ACTH) stimulates cortisol production to assist your body in daily function and stress. Vasopressin assists in the salt and water regulation of the body. Gonadotropins (FSH, LH) stimulate the ovaries (in women) or testes (in men) to release "sex" hormones (estradial or testosterone). Growth Hormone is released from the pituitary gland to cause growth in children and affects bone density, lipid metabolism, and muscle in children and adults.
Deficiencies of these hormones may occur alone or in combination with one or more other hormone deficiencies. The hormone(s) deficiency may be congenital, resulting from a defect in the brain. The deficiency may also be acquired, stemming from the damage to the brain after a severe head injury, serious illness (such as meningitis or encephalitis), brain tumor and/or radiation. Sometimes no cause for the hormone deficiency can be identified.
In order to confirm or determine the possibility of hormone deficiencies your doctor will perform an examination and ask you some questions. Past records may have to be reviewed. Screening blood tests will usually be done. These blood tests will check the secretion of the pituitary hormones and their target organs.
Possible tests that may be done are listed:
T4/TSH (to test thyroid function
Cortisol FHS/LH (to test stimulation ability of the ovaries/testes)
IGF-1 (an indirect measure of growth hormone)
Electrolytes (measures water & salt balance)
You may need to have a picture of the brain; this is done by a CT Scan or MRI. A CT scan gives a detailed picture of the brain using x-rays and a computer. A MRI gives a detailed picture of the brain using a magnet, radio waves and a computer. These tests are not painful but you will have to hold still for approximately one hour during the test.
If there is a possibility that you have growth hormone deficiency more testing will have to be performed. Growth hormone is secreted by the pituitary gland in quick bursts and does not last long in the blood, so checking a single blood sample for growth hormone will not be helpful. Deep sleep, vigorous exercise, and certain drugs are known to stimulate the secretion of growth hormone. The amount of growth hormone in the blood is measured by taking blood samples over a period of time. This is done by performing a "stimulation test." This refers to drawing baseline hormone levels, stimulating growth hormone release by giving a drug, and drawing intermittent growth hormone levels for one to three hours. The specifics of the tests, such as type of drug, length of test, and amount of the samples, will be determined by your doctor.
The doctor will need to make sure you are on adequate hormone replacement for other hormone deficiencies prior to stimulation testing. You will be given instructions. You should not have anything to eat or drink, except for water, after midnight the night before the test. You should have minimal activity before the test (no exercise that morning). An indwelling venous line (IV) will be started and baseline hormone levels drawn. You will be given a medication. The medication and its effects will be reviewed by your doctor or nurse. Growth hormone levels will be drawn intermittently from the IV at specified times for a period of two hours. If the IV stops working during the test, it is important that it be restarted so the samples may be obtained at the specified times.
The purpose of the testing is to determine if you are growth hormone deficient and/or eligible for growth hormone therapy. In order to start growth hormone treatment you will have one to two simulation tests performed. The number of tests will be decided by your doctor. Adults with peak growth hormone levels less than 3-5 mcg/L are identified as Growth Hormone Deficient. Please keep in mind that these numbers are not definitive; your doctor will make the final diagnosis. It may take several weeks for your doctor to receive and review the test results. You should discuss the results and the possibility of growth hormone therapy with your doctor.
Hormone replacement will be prescribed by your doctor if you are deficient in pituitary hormones. Remember that each hormone has a specific function in your body, replacement medication is very important. If you have any questions don't hesitate to call your doctor, nurse, or the MAGIC Foundation for resources.
[Note: Despite advertisements for oral Growth Hormone, the fact is that in order for GH medication to actually "work" on a body it must be by injection.]
Growth hormone is given by injection. It is given daily underneath the skin into fat tissues. Most individuals give it in the fat in the lower abdomen. The needles and syringes are the same used by diabetic patients. These are dispensed by the pharmacist with a prescription for insulin syringes and attached needles. You will also need a container to dispose of these needles and syringes. They should not be disposed of in the usual trash. You will need a special “sharps container” for disposal. The dose of growth hormone will be calculated by your doctor. The dose may change depending upon your responses and blood tests taken to monitor therapy.
What Symptoms Suggest Too Much Growth Hormone Therapy?
If you are receiving too much growth hormone you may have symptoms such as swelling of the ankles, aching in your joints, or pain in your hands. Your blood pressure may also rise to a level above normal. If these symptoms occur, you should notify your physician. Most patients feel more energy and an improved sense of well-being shortly after beginning therapy. You can expect to feel better in two to three weeks, but may not feel the full improvement for three to six months as your doctor slowly increases the does to the right level for you.
We need growth hormone all of our lives, not only as children for growth purposes. We need growth hormone as adults to keep our bodies in proper balance. Without growth hormone as adults we have reduced energy and our body composition changes to more fat, less muscle and less bone. Replacement of this hormone in adults, when this hormone is deficient, will restore the body to a more normal and healthy balance. This continued, lifelong therapy should help you live a more normal and healthy life.
Contributing Medical Specialists
David Cook, M.D.
Oregon Health Sciences Univ.
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