Acromegaly is a hormonal disorder that develops when your pituitary gland produces too much growth hormone during adulthood.
The pituitary, a small gland in the brain, makes growth hormones. When this happens, your bones increase in size, including those of your hands, feet and face. Usually the excess GH comes from benign, or noncancerous, tumours on the pituitary. These benign tumours are called adenomas. Acromegaly usually affects middle-aged adults.
Over time, this leads to abnormally large hands and feet, and a wide range of other symptoms.
Acromegaly is usually diagnosed in adults aged 30 to 50 but can affect people of any age. When it develops before puberty, it's known as "gigantism"
Symptoms
The name acromegaly comes from the Greek words for "extremities" and "enlargement," reflecting one of its most common symptoms—the abnormal growth of the hands and feet.
One of the most common signs of acromegaly is enlarged hands and feet. People with this disorder often notice that they can no longer put on rings that used to fit and that their shoe size has progressively increased.
Acromegaly may produce the following signs and symptoms, which can vary from one person to another:
Enlarged hands and feet
Coarsened, enlarged facial features
Coarse, oily, thickened skin
Excessive sweating and body odour
Small outgrowths of skin tissue (skin tags)
Fatigue and muscle weakness
A deepened, husky voice due to enlarged vocal cords and sinuses
Severe snoring due to obstruction of the upper airway
Impaired vision
Headaches
Enlarged tongue
Pain and limited joint mobility
Menstrual cycle irregularities in women
Erectile dysfunction in men
Enlarged liver, heart, kidneys, spleen and other organs
Increased chest size (barrel chest)
Causes of acromegaly
Acromegaly happens because your pituitary gland (a pea-sized gland just below the brain) produces too much growth hormone.
Pituitary Tumours
In more than 95 percent of people with acromegaly, a benign tumour of the pituitary gland, called an adenoma, produces excess Growth Hormones. Pituitary tumors are labeled either micro- or macro-adenomas, depending on their size.
Nonpituitary Tumours
Rarely, acromegaly is caused not by pituitary tumors but by tumors of the pancreas, lungs, and other parts of the brain. These tumors also lead to excess Growth Hormones, either because they produce GH themselves or, more frequently, because they produce GHRH, the hormone that stimulates the pituitary to make GH. When these non-pituitary tumors are surgically removed, Growth Hormones levels fall and the symptoms of acromegaly improve.
Complications
Progression of acromegaly can result in major health problems. If you do not get treatment, you may be at risk of developing:
High blood pressure (hypertension)
Cardiovascular disease, particularly enlargement of the heart (cardiomyopathy)
Osteoarthritis
Diabetes mellitus
Goiter
Precancerous growths (polyps) on the lining of your colon
Sleep apnea, a condition in which breathing repeatedly stops and starts during sleep
Carpal tunnel syndrome
Reduced secretion of other pituitary hormones (hypopituitarism)
Uterine fibroids, benign tumors in the uterus
Spinal cord compression
Vision loss
Diagnosis
Many people with acromegaly don’t know they have the condition because the onset of symptoms is usually slow. However, if your doctor suspects you have acromegaly, they can test you for it. Acromegaly is most often diagnosed in middle-aged adults, but the symptoms may appear at any age.
GH and IGF-I measurement.
After you've fasted overnight, your doctor will take a blood sample to measure your levels of growth hormones and IGF-I (Insulin-like growth factor 1). Elevated levels of these hormones suggest acromegaly.
Growth hormone suppression test.
This is the definitive method for verifying acromegaly. In this test, your blood levels of growth hormones are measured before and after you drink a preparation of sugar. Normally, glucose ingestion depresses levels of growth hormones. If you have acromegaly, your growth hormones level will tend to stay high.
Imaging.
Your doctor may recommend that you undergo an imaging procedure, such as magnetic resonance imaging, to help pinpoint the location and size of a tumor of your pituitary gland. If radiologists, who usually perform the procedures, see no tumor of your pituitary gland, they may look for nonpituitary tumors that might be responsible for high levels of growth hormones.
Treatment
The type of treatment offered for acromegaly depends on the symptoms you have. Usually the goal is to:
Reduce growth hormone production to normal levels.
Relieve the pressure a tumour may be putting on surrounding tissues.
Treat any hormone deficiencies.
Improve your symptoms.
Medicines
If your levels of growth hormone are still higher than normal after surgery, or surgery wasn't possible, you may be prescribed medication.
Three different types of medicine are used:
Somatostatin analogues: A monthly injection of either octreotide, lanreotide or pasireotide. This slows down the release of growth hormone and can sometimes also shrink tumours.
Growth hormone antagonist: A daily pegvisomant injection blocks the effects of growth hormone and can significantly improve symptoms.
Dopamine agonists: Bromocriptine or cabergoline tablets can stop growth hormone being produced, but they only work in a small proportion of people.
Radiation
Radiation may be used to destroy large tumors or sections of tumor left after surgery or when medications alone aren’t effective. Radiation can slowly help to lower GH levels when used along with medication. A dramatic decrease in GH levels using this type of treatment may take several years, with radiation administered in multiple four- to six-week sessions. Radiation can impair your fertility. In rare cases, it can lead to vision loss, brain injury, or secondary tumors.
Surgery
surgeon can remove most pituitary tumors using a method called transsphenoidal surgery. In this procedure, your surgeon works through your nose to extract the pituitary tumor.
Removing the tumor can normalize GH production and eliminate the pressure on the tissues surrounding your pituitary gland to relieve associated signs and symptoms. In some cases, your surgeon may not be able to remove the entire tumor. This may result in persistently elevated GH levels after surgery, requiring further medical or radiation treatments.
Most people with acromegaly will have a pituitary tumour that needs to be surgically removed. Medication or radiotherapy may sometimes be needed after, or instead of, surgery.
