Most of us stop growing by our early twenties, but for a very few people with a rare condition, their bodies continue to grow. Learn more about this rare disease.
What is acromegaly?
Acromegaly is a disease that causes some bones, organs and other tissue to continue to grow bigger, well after most adults stop growing, due to excessive human growth hormone. It is very rare—according to the National Institute of Diabetes and Digestive and Kidney Diseases, only an estimated three to 14 people out of 100,000 have been diagnosed with it.
What causes acromegaly?
Most people diagnosed with acromegaly have no known risk factors. Most of the time, acromegaly is caused by a benign tumor, known as an adenoma, on the pituitary gland. The pituitary is a small gland attached to the base of the brain. It is responsible for controlling our growth and physical development, as well as controlling the other endocrine glands, such as the thyroid, adrenal glands, ovaries and testes.
These non-lethal pituitary tumors produce an excessive amount of human growth hormone (GH) which stimulates the liver to produce high levels of insulin-like growth factor-I (IGF-I). Both GH and IGF-I lead to the relatively slow but continuous growth of body parts well into adulthood.
A rare inherited condition, known as multiple endocrine neoplasia type 1 (MEN1), is the main known risk factor for developing acromegaly. This condition can lead to tumor formation in certain areas, including the pituitary gland and pancreas. Acromegaly can also run in families, though that is even more rare than MEN1.
What are the symptoms of acromegaly?
The most obvious symptom is also difficult to notice—the continued growth of body parts happens slowly, over time, and most people won’t realize it for many years. Any part of the body can be affected, but the body parts where it’s most noticeable include:
- Hands and feet
- Jaw and forehead structure
- Nose, lips and tongue
Other common symptoms include:
- Elevated blood pressure
- Diabetes
- Irregular menstrual cycles
- Decreased sexual desire and erectile dysfunction
- Joint pain
- Fatigue
- Sweating
- Skin tags
- Sleep apnea
- Carpal tunnel syndrome or tingling and numbness in the hands
- Headaches
- Visual impairment
- Colon polyps
- Heart arrythmia
These common symptoms can share many different causes, which makes it difficult to diagnose acromegaly early on.
How is acromegaly diagnosed?
Once acromegaly is suspected, it can be diagnosed by checking the level of IGF-I in the blood, which is a screening test. Then blood tests will need to be done to see whether blood growth hormone (GH) level can be suppressed after taking certain amounts of glucose by mouth, which is called an oral glucose tolerance test (OGTT). A pituitary MRI is used to find pituitary tumors in patients with elevated levels of IGF-I and growth hormone.
How is acromegaly treated?
Surgery, medications and irradiation are three modes of treatment for acromegaly.
In certain early cases, when the pituitary tumor is diagnosed early, typically when the tumor is less than 5-10 mm in diameter and confined in the pituitary gland, acromegaly can be completely cured through surgical removal of the pituitary tumor.
In cases where the tumor is larger, or if it’s too close to important nerves or blood vessels, some of the tumor may remain after surgery, which can lead to continuous elevated growth hormone levels.
There are certain medications that can help reduce the levels of growth hormone and insulin-like growth hormone-I (IGF-I) in the body. These medications can signal the pituitary to produce less growth hormone, or block GH effects or shrink tumors, but they do not remove the tumors entirely as surgery can. The medications can be monthly injections or daily oral pills.
Depending on the patient and the tumor, radiation therapy can be used to target the adenoma. For instance, when there is remaining tumor after surgery, and when the patient failed medication treatments, or is not able to tolerate medications or prefers not to receive long term injections, radiation therapy will be considered.
It should be noted that the effects of radiation therapy occur gradually over time. It takes several years for the radiation to effectively lower the growth hormone levels. Before the effects occur, patients need to be treated with medications. Also, irradiation of a pituitary tumor sometimes causes long term low pituitary function (hypopituitarism) which requires hormonal replacements.
When to talk to a doctor about symptoms
As most of the symptoms for acromegaly are shared among many other conditions, it’s important to talk to your doctor about changes in your health. While it’s unlikely that acromegaly is causing these health concerns, there may be other conditions that require treatment.
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