Acromegaly

Overview

Acromegaly is a chronic disease that is caused by the overproduction of growth hormone. Growth hormone is a substance secreted by the pituitary gland, a tiny gland located below the brain, behind the eyes. Growth hormone stimulates growth of bones and soft tissue in children and regulates metabolism in adults.

In most cases of acromegaly, this excessive production of growth hormone is due to a pituitary tumor, the majority of which are benign (not malignant). The excess growth hormone leads to enlargement of hands, feet, and facial features. It can also affect internal organs and cause a variety of potentially serious complications if left untreated.

 

Who Is More At Risk

Acromegaly most commonly affects middle-aged adults and is a relatively rare disorder. Most pituitary tumors arise spontaneously and are not inherited. It is estimated that about 3 of every million people develop acromegaly each year and that 60 of every million people have the disease at any time. However, because the symptoms of acromegaly are easily missed, these numbers may actually be higher.

 

Diagnosis

Acromegaly is diagnosed using blood and imaging testing. A doctor will use a blood test to measure the amount of GH, or growth hormone, in the bloodstream. But GH levels in the body can rise and fall in spurts, so a test that measures GH levels in the body is not enough to diagnose acromegaly.

As a next step, a doctor may conduct an oral glucose tolerance test. This test pushes a healthy person's GH levels below 1 nanogram per milliliter. If an individual has acromegaly, this drop in GH will not occur.

If a doctor does not use an oral glucose tolerance test, they will measure a patient's IGF-1 levels. IGF-1 levels are more stable in the body than GH levels are, so this test is a reliable indicator of acromegaly.

From this point, a doctor will request an MRI or CT scan to locate the tumor on the pituitary gland and indicate its size. Pituitary tumors are rarely too small to be detected. If a tumor can not be found, doctors may search for ectopic tumors in the chest, abdomen, or pelvis.

For additional information on acromegaly symptoms and diagnosis, visit Acromegaly Info.