Acromegaly is a rare condition caused by a prolonged increase in the amount of growth hormone (GH), which regulates physical growth. It most often is seen in middle-aged adults. Acromegaly is almost always caused by a GH-secreting pituitary tumor. Very rarely, a tumor in another part of the body will produce excess GH or another hormone (GHRH) that causes the pituitary gland to release more GH.
GH triggers the liver to produce and release yet another hormone called IGF-1 (insulin-like growth factor-1). IGF-1 causes bone, cartilage and body tissues to grow. It can also affect the way the body handles blood sugar and fats (lipids).
Because the changes associated with acromegaly occur gradually, patients may note the need to get larger gloves, rings, shoes or hats. Your physician may ask you to bring in old photos of yourself to compare to your current appearance.
In children, the growth plates of long bones do not fuse until the end of puberty. Excess GH in childhood leads to gigantism. There is very rapid growth of all bones so that the child becomes extremely tall. There may also be increased sweating and joint pain.
Signs and Symptoms
Acromegaly produces a variety of medical problems and leads to a change in appearance. Some of the typical signs and symptoms of acromegaly include:
- Growth and swelling in the hands and feet
- Enlargement of the lips, nose and tongue
- Deeper voice
- Changes in the facial structure. The brow may become more prominent, the jaw bone will jut out, the bridge of the nose widens and space(s) between teeth increase.
- Changes in skin, such as increased thickness, coarseness and/or oiliness
- Increases in sweating and body odor
- Enlargement or darkening of skin tags
- Aches in joints
- Problems with vision
- Medical problems
- High blood pressure (hypertension)
- Heart disease
- Type 2 diabetes
- Sleep apnea
- Colon polyps
The exact cause of acromegaly is not currently known. Genetic factors may play a role in the development of tumors which produce GH. Acromegaly has been linked to defects in certain genes.
The presence of symptoms often leads to a physician visit. Diagnosis begins with the medical history and physical examination. The same imaging tests for a pituitary adenoma are used. Since the levels of GH vary throughout the day, two specific blood tests are used to help diagnose acromegaly: IFG-1 and oral glucose tolerance test. These tests are elevated in acromegaly.