|
Human Growth hormone (HGH) is a protein hormone made by the pituitary, a hormone producing gland located at the base of the skull. The pituitary gland not only produces HGH, but releases (secretes) HGH into the bloodstream. After entering the bloodstream, HGH attaches to certain tissues, especially bones, and results in height increase in children. Damage to the pituitary gland in children results in low HGH secretion in children, resulting in poor growth and resultant short stature. HGH can be given to children to restore their normal growth and development.
Over the last ten years, it has been discovered that adults need GH too. Like children, adults can be given this hormone if deficient. The approval by the FDA to give HGH to deficient adults has been in place for the last two years. Since adults have already achieved their genetically determined height, loss of HGH does not impact height, but it does affect the body in many other ways. If adults have a deficiency of HGH, major changes to the composition of the body results. These changes include loss of muscle, accumulation of fat, especially in the abdomen, and a decrease in the density (but not the length) of bones. Because HGH is also necessary for normal brain function, adults without this hormone have psychological changes in addition.
Description of the Adult HGH Deficiency Syndrome
There are three components to the adult HGH deficiency syndrome. These are body composition changes, blood lipid (cholesterol and fat) changes, and psychological changes. Because HGH maintains muscle and fat, loss of this hormone results in a decrease in muscle and in an accumulation of fat. The decrease in muscle translates to poor muscle function and decreased exercise capacity. The increase in fat occurs under the skin, but also in the abdomen or, more specifically, inside the abdomen. This location is referred to as visceral fat. Medical science has discovered that visceral fat accumulation is especially dangerous because it is associated with an increase in the aging of blood vessels, referred to as atherosclerosis. The blood lipid changes reflect the fat deposit changes and are all in the wrong direction. More specifically, there is an increase in the "bad" cholesterol ("LDL cholesterol") and a decrease in the "good" cholesterol ("HDL cholesterol"). There is also an increase in the blood triglycerides, another circulating fat, which is associated with blood vessel aging.
The psychological changes associated with HGH deficiency have been extensively studied. Patients who develop HGH deficiency seem to lose energy. Loss of energy is often the guiding symptom which prompts further investigation. Many individuals with pituitary disease, especially those with other hormone deficiencies, realize that something is missing. Frequently, it turns out to be a deficiency of HGH. Individuals with this problem, or their spouses, also notice a loss of interest in their usual hobbies or activities. A decrease in sociability referred to as social isolation is another symptom. Patients suffering with this symptom do not like to go out and meet with their friends or social acquaintances. Patients may also develop mild depression or decrease in sexual function.
Treatment with GH
Once a physician has proven HGH deficiency, he or she will begin the patient on a small dose of HGH and slowly raise the dose until a final maintenance dose is reached. The hormone is given by injection. Small needles and syringes are used. The test used to find out what HGH levels are is the insulin-like growth factor test ("IGF-1 test"). It is a single blood test which reflects the amount of HGH administered, although it is not HGH itself. IGF-1 values which are low prompt a larger dose or growth hormone is needed; values which are too high prompt a lower dose. The symptoms of HGH excess include muscle or joint pain, retention of fluid (called edema) and carpal tunnel, which consists of pain and/or numbness in the hands. These symptoms, if severe, will also help determine the dose.
Summary Deficiency of HGH in the adult has been recently described. It has recently been approved as acceptable therapy by the FDA. Improvement in most of the symptoms and body composition changes induced by this deficiency change for the better with successful therapy.
|