Dr.M.J. Bazos, MD Patient Handout


About Your Diagnosis

Acromegaly is a disease caused by excess growth hormone (GH). Growth hormone levels are tightly regulated by the body to allow for normal growth and development. Growth hormone–releasing hormone (GHRH) is secreted from the hypothalamus in the brain, causing the pituitary to secrete GH. Growth hormone circulates in the blood and causes the liver to secrete insulin-like growth factor-1 (IGF- 1). Insulin-like growth factor-1 acts on the bones and body tissues to promote growth and development. In most individuals, GH is decreased by IGF-1 and a hormone called somatostatin. In acromegaly, there is abnormal secretion of GH from a tumor, usually located in the pituitary. The tumor does not decrease GH secretion in response to IGF-1 or somatostatin, leading to increased GH levels over time. Occasionally, tumors elsewhere in the body may produce extra GHRH, which causes the pituitary to secondarily overproduce GH. There are approximately 750 new cases of acromegaly each year in the United States. However, 10–20 times as many individuals are currently living with the disease. After a complete medical history and physical examination, acromegaly is detected by measuring levels of GH and IGF-1 in the blood. Levels of IGF- 1 are more easily measured because they are stable throughout the day. Insulin-like growth factor-1 levels may be falsely elevated during pregnancy, whereas IGF-1 levels decrease in older individuals
and individuals with diabetes. Because GH levels fluctuate widely during the day, GH is best measured 1 hour after drinking a sweet liquid during an oral glucose tolerance test (OGTT). Acromegaly is confirmed by an elevated GH level. Pituitary magnetic resonance imaging (MRI) is then used to locate the lesion. If the pituitary MRI is normal, a GHRH level is measured. An elevated GHRH suggests a tumor elsewhere in the body is causing acromegaly. Most individuals can expect significant relief of their symptoms once the diagnosis is established and the tumor is surgically removed. Some tumors may not be completely respectable. Symptomatic relief may still be obtained through a combination of surgery, radiation therapy, and medications.

Living With Your Diagnosis
Signs and symptoms include an increase in the size of hands and feet (gloves, rings, and shoes are too tight), headaches, blurry vision, high blood pressure,
joint pains, carpal tunnel syndrome (numbness of the fingers in the hand), high blood sugars, changes in a woman’s menstrual cycle, or male impotence. There may be a change in facial features (more prominent forehead, jaw, lips, tongue, and increased space between teeth), deepening of the voice, or increased snoring. Acromegaly may cause hypertension, diabetes, arthritis, carpal tunnel syndrome, heart disease, and sleep apnea.

The best treatment is transsphenoidal surgery to remove the pituitary tumor. The operation is performed through the nose or above the lip. No scar is noticed on the skin. Cure rates of 60% or greater are achieved by the most experienced surgeons. Transsphenoidal surgery may be complicated by infections of the cerebrospinal fluid, leakage of cerebrospinal fluid into the mouth, or damage to the pituitary. Medications are also effective for acromegaly. Bromocriptine is the most commonly used medicine. It should be taken at bedtime with food and started at a very low dose to minimize side effects such as nausea, lightheadedness, and nasal congestion. Approximately 50% of those individuals not cured by surgery will have normal GH and IGF-1 levels with bromocriptine. Octreotide, a somatostatin analogue, may be used for the remaining patients. This medicine must be given via subcutaneous injection every 8 hours. Octreotide may cause nausea, diarrhea, gallstone formation, or diabetes. Finally, radiation therapy may be used to control acromegaly. This is best used for patients who are not candidates for surgery or who are not cured by surgery alone. Approximately 50% of patients will have normal GH and IGF-1 levels within 2–5 years of therapy. Visual loss may occur if the optic nerves are damaged from the radiation.

The DOs
• Initially take bromocriptine at bedtime with food.
• Start with a low dose of bromocriptine and increase the dose slowly (over several weeks).
• Follow-up with your doctor regularly. Tumors may recur.
• Have your blood pressure, blood sugars, and heart examined regularly for possible complications from acromegaly.

The DON’Ts
• Don’t expect immediate relief of all your symptoms.
• Don’t be afraid to try a combination of treatments.
• Don’t eat before your OGTT. This will invalidate the test.
• Don’t forget to have your eyes examined.

When to Call Your Doctor
• Your vision changes.
• You have worsening headaches.
• You notice new nerve pains or numbness anywhere in your body.
• You have chest pain or pressure.
• You have side effects from your medication including nausea, dizziness, or lightheadedness.

National Institute of Diabetes and Digestive and Kidney Diseases