Diseases & Conditions

 

Acromegaly

Diseases & Conditions

 

What is acromegaly?

Acromegaly is a hormonal disorder characterized by overgrowth of body tissues increasing the size of the hands, feet and face. Normally, the pituitary gland located at the base of the brain releases growth hormone to stimulate growth and development in children. In adults, growth hormone affects energy levels, muscle strength, and bone health. In acromegaly, the pituitary gland produces excessive amounts of growth hormone.

Acromegaly is a rare disease with a prevalence of 60 per million and an incidence of 3-4 per million per year.1

 

What causes acromegaly?

Acromegaly is usually caused when the pituitary gland overproduces growth hormone and raises its level in the blood. Secretion of growth hormone raises the level of insulin-like growth factor, a hormone produced by the liver that causes tissue growth in the body. The overproduction of growth hormone can be caused by:2

  • Pituitary tumors: A benign tumor of the pituitary gland called adenoma
  • Nonpituitary tumors: Some tumors in the lungs, pancreas or adrenal gland can secrete growth hormone and lead to acromegaly

 

What are the symptoms of acromegaly?

The main symptom of acromegaly is the abnormal growth of skin, connective tissue, cartilage, bone, organs, and other tissues in the body. This enlargement is caused by the excessive amount of insulin-like growth factor. The main symptoms include:3

  • Enlargement of hands and feet.
  • Excessive growth of face and head
  • Excessive soft tissue growth of the throat
  • Thickening of the skin
  • Overgrowth of the bones

 

 What are the complications of acromegaly?

If left untreated, acromegaly can result in major health problems. Complications may include:4

  • Hypertension
  • Enlargement of the heart muscle leading to cardiovascular disease
  • Osteoarthritis
  • Diabetes: Excessive growth hormone production leads to an increase of glucose levels in the blood
  • Tumors: If acromegaly is not treated, patients have an increased risk of developing tumors such as colon cancer.
  • Snoring and sleep apnea, a breathing problem that happens during sleep
  • Tingling or pain in fingers known as carpal tunnel syndrome
  • Reduced secretion of other pituitary hormones (hypopituitarism)
  • Benign tumor of the uterus
  • Spinal cord compression
  • Vision problems

 

How is acromegaly diagnosed?

If acromegaly is suspected based upon a person's appearance, the diagnosis must be confirmed by:5

  • Blood test to measure the levels of growth hormone and insulin-like growth factor. Usually the level of these hormones fluctuates; therefore several blood tests are needed.

 

  • Imaging tests to learn about the location and size of the tumor:
    • X-ray
    • Computerized tomography (CT) scan
    • Magnetic resonance imaging (MRI)

 

How is acromegaly treated?

Treating acromegaly includes medications, surgery to remove the tumor and radiation therapy of the pituitary gland:6

Medication:

  • Somatostatin analogs to stop growth hormone production and lower the level of insulin-like growth factor in the blood
  • Growth hormone receptor antagonists which interfere with the action of growth hormone normalizing the level of insulin-like growth factor in the blood
  • Dopamine agonists to lower the level of these hormones

Surgery

to remove the pituitary gland which will lower growth hormone levels. Face and soft tissue swelling improve within a few days after surgery.

Radiation therapy:

If some tumor remains after surgery, radiation is used to slowly lower growth hormone and insulin-like growth factor levels. Radiation therapy targets the tumor with beams but can damage surrounding tissue.


 References:

  1. Holdaway, I. M., and C. Rajasoorya. "Epidemiology of acromegaly." Pituitary 2.1 (1999): 29-41.
  2. Acromegaly (Causes) http://www.mayoclinic.org/diseases-conditions/acromegaly/basics/causes/con-20019216 (Accessed December 17, 2015)
  3. Patient information: Acromegaly (Beyond the Basics) (Acromegaly) http://www.uptodate.com/contents/acromegaly-beyond-the-basics (Accessed December 17, 2015)
  4. Acromegaly (Complications) http://www.mayoclinic.org/diseases-conditions/acromegaly/basics/complications/con-20019216 (Accessed December 17, 2015)
  5. Acromegaly: Causes, Symptoms, and Treatment (WebMD) http://www.webmd.com/a-to-z-guides/acromegaly-causes-symptoms-treatment?page=2 (Accessed December 17, 2015)
  6. Acromegaly (Acromegaly) http://www.niddk.nih.gov/health-information/health-topics/endocrine/acromegaly/Pages/fact-sheet.aspx (Accessed December 17, 2015)