An overview of Acromegaly

Acromegaly is a hormonal disorder that develops when your pituitary gland produces too much growth hormone during adulthood.

Acromegaly results from an excess amount of growth hormone (GH) in the body. The extra amount of GH causes excess growth in the bones and soft tissues of the body. Children with the condition can grow to abnormal heights. They may also have an exaggerated bone structure. Acromegaly mostly affects the arms, legs, and face.

Acromegaly and gigantism are both conditions that result from excess growth hormone (GH). The difference is in who the conditions affect — adults develop acromegaly, whereas children develop gigantism.

In children, gigantism occurs when they experience excess GH before the growth plates in their bones fuse (before the end of puberty). This causes them to grow very tall. Gigantism is more rare than acromegaly. Some healthcare providers refer to gigantism as pediatric acromegaly.

Once your growth plates have fused, excess GH causes acromegaly. In this case, you don’t grow in height, but the excess GH affects your bones’ shape and your organ size as well as other health factors.

The overproduction of growth hormone that is associated with acromegaly normally results from a tumor.

Pituitary adenoma

The most common type of tumor is a non-cancerous, or benign, tumor in the pituitary gland, known as a pituitary adenoma.

The tumor causes the pituitary gland to produce excess growth hormone (GH), leading to abnormal growth.

Pituitary tumors are not genetically inherited from parents. They can appear randomly, due to a small genetic change of one cell within the gland.

Over time, this cell will replicate and form a tumor, called an adenoma. Adenomas are not malignant, because they do not spread to other parts of the body, but they may cause problems due to their size and location.

As the tumor grows, it can put pressure on surrounding brain tissue. Because the skull is a closed space, this growth can crowd the remaining tissue, leading to headaches and vision problems.

The location of the tumor means that the production of other hormones can also be affected.

The impact can be different for men and women, due to the type of hormone affected. Women may find that it affects their menstrual cycle, while some men experience impotence.

Around 17 percent of the population are thought to have small pituitary adenomas that do not usually produce excess growth hormone or cause any symptoms. It is only when a larger tumor occurs that the problems arise.

It is also important to note that most pituitary adenomas do not secrete any hormone. However, of the ones that do, growth hormone-secreting adenomas account for a third of cases.

Other Causes

In rare cases, a tumor elsewhere in the body, such as the lungs, adrenal glands, or pancreas, can lead to an overproduction of GH, resulting in symptoms of acromegaly.

This growth hormone may either be produced by the tumors themselves or because the pituitary gland is responding to a stimulus to produce GH. For example, some hypothalamic tumors may secrete growth hormone releasing hormone (GHRH), which tells the body to produce GH.

Sometimes, acromegaly is due to increased growth hormone production from outside the pituitary gland, such as from neuroendocrine tumors like small cell lung cancer or carcinoid tumors.

A common sign of acromegaly is enlarged hands and feet. For example, you may notice that you aren't able to put on rings that used to fit, and that your shoe size has progressively increased.

Acromegaly may also cause gradual changes in your face's shape, such as a protruding lower jaw and brow bone, an enlarged nose, thickened lips, and wider spacing between your teeth.

Because acromegaly tends to progress slowly, early signs may not be obvious for years. Sometimes, people notice the physical changes only by comparing old photos with newer ones.

4. pain and tenderness when touched or not

Overall, acromegaly signs and symptoms tend to vary from one person to another, and may include any of the following:

1. Enlarged hands and feet

2. Enlarged facial features, including the facial bones, lips, nose and tongue

3. Excessive sweating and body odor

4. Small outgrowths of skin tissue (skin tags)

5. Fatigue and joint or muscle weakness

6. Pain and limited joint mobility

7. A deepened, husky voice due to enlarged vocal cords and sinuses

8. Severe snoring due to obstruction of the upper airway

9. Vision problems

10. Headaches, which may be persistent or severe

11. Menstrual cycle irregularities in women

12. Erectile dysfunction in men

13. Loss of interest in sex

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.

Blood Tests

Blood tests can determine if you have too much GH, but these aren’t always accurate because GH levels fluctuate throughout the day. Instead, your doctor may order a glucose tolerance test. This test requires you to drink 75 to 100 grams of glucose and then have your GH levels tested. If your body is secreting normal levels of GH, excess glucose will cause your body to suppress your GH levels. People who have acromegaly will still show high GH levels.

Insulin-Like Growth Factor 1 (IGF-1)

Doctors may also test for a protein called insulin-like growth factor 1 (IGF-1). Levels of IGF-1 can show if there is abnormal growth in the body. IGF-1 testing can also be used to monitor the progress of other hormone treatments.

Imaging Studies

X-rays and MRI scans may be ordered to check for excess bone growth if your doctor suspects you have acromegaly. Your doctor will also perform a physical exam, and they may order a sonogram to check the size of internal organs.

After you’re diagnosed with acromegaly, your doctor can use MRI and CT scans to help them find the pituitary tumor and determine its size. If they don’t find a tumor on the pituitary gland, your doctor will look for tumors in the chest, abdomen, or pelvis that may be causing excess GH production.

The NIH estimates that three to four out of every 1 million people develop acromegaly every year and that 60 out of every 1 million people have the condition at any given time. However, since the condition often goes undiagnosed, the total number of affected individuals is probably underestimated.

Treatment for acromegaly is based on your age and overall health. The goals of treatment are to:

1. bring GH production levels back to normal

2. relieve pressure around any growing pituitary tumors

3. maintain normal pituitary function

4. treat any hormone deficiencies and improve the symptoms of acromegaly

The treatments include :

Surgery

Surgery to remove the tumor causing excess GH is the first option doctors usually recommend to people with acromegaly. Usually, this treatment is quick and effective in reducing GH levels, which can improve symptoms. One possible complication is damage to the pituitary tissues that surrounded the tumor. If this happens, it can mean you’ll need to start a lifelong pituitary hormone replacement treatment. Rare but serious complications include cerebrospinal fluid leaks and meningitis.

Medication

Medication is another treatment option that’s often used if surgery isn’t successful in reducing GH levels, and it can also be used to shrink large tumors before surgery. These types of medications are used to regulate or block GH production:

somatostatin analogs

GH receptor antagonists

dopamine agonists

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.

If left untreated, acromegaly can lead to major health problems. Complications may include:

1. High blood pressure (hypertension)

2. High cholesterol

3. Heart problems, particularly enlargement of the heart (cardiomyopathy)

4. Type 2 diabetes

5. Enlargement of the thyroid gland (goiter)

6. Precancerous growths (polyps) on the lining of your colon

7. Sleep apnea, a condition in which breathing repeatedly stops and starts during sleep

8. Increased risk of cancerous tumors

9. Vision changes or vision loss

10. Spinal cord compression or fractures

The outlook for people with acromegaly is usually positive if the condition is discovered in the early stages. Surgery to remove pituitary tumors is usually successful. Treatment may also help keep acromegaly from having long-term effects.