Acromegaly: Symptoms, Causes, Complications, Risks, Diagnosis, Treatment and Outlook

0
48
acromegaly

1Overview

The different hormones in the body are responsible for various body systems and functions. The pituitary gland is a pea-sized structure situated at the base of the brain which produces important hormones. These chemical substances control many body functions.

If there is a problem in the production of these hormones, it may lead to serious consequences. One condition that might transpire as a result of an abnormality in the hormones produced by the pituitary gland is acromegaly.

Some people are taller than others. However, in a condition called acromegaly, there is too much growth hormone (GH) in the body, resulting to a person having an increase in bone size in the hands, feet and even in the face. This condition often affects people in their middle adulthood.

Acromegaly can lead to serious health problems and in some cases, it can be life-threatening if it’s left untreated. The most serious health complications linked to acromegaly are high blood pressure, type 2 diabetes, arthritis and cardiovascular disease.

Also, since the condition is rare and the physical changes happen gradually, the condition is not recognized early. It may even take a couple of years before a diagnosis is made.

The incidence rate of acromegaly is about 5.3 per 1 million per year. An estimated 60 out of every 1 million people suffer from the condition at any time and it affects both men and women equally. People who are between the ages 40 to 60 are the ones most affected by the disease.

2Symptoms

Acromegaly comes from the Greek words that mean “enlargement” and “extremities”. These words describe what happens in acromegaly – the abnormal growth of the hands and feet. The inflammation of the hands and feet is the most common and early features. Most patients may observe the changes in the ring or shoe size, especially when it comes to the foot’s width.

Acromegaly may cause progressive changes in the shape of the face, such as an enlarged nose, thickened lips, protruding lower jaw and brow, and wider spaces between the teeth.

The most common signs and symptoms of acromegaly include:

  • Joint pain
  • Thick, coarse and oily skin
  • Excessive sweating and skin odor
  • Skin tags
  • Sleep apnea
  • Excessive tiredness
  • Headaches
  • Vision problems
  • Decreased libido
  • Erectile dysfunction
  • Abnormal menstrual cycle
  • Deep and husky voice
  • Severe snoring
  • Enlarged tongue
  • Increased chest size (barrel chest)
  • Enlarged liver, kidneys, heart, spleen and other organs

3Causes

Acromegaly is caused by a non-cancerous tumor in the pituitary gland, dubbed as pituitary adenoma. This tumor secretes excessive amounts of growth hormone. As a result, the hormone levels in the blood is increased. This also increases the levels of growth factor-1 (IGF-1), a hormone that’s secreted in the liver.

When GH is secreted in the blood, it stimulates the liver to produce IGF-1, to trigger the growth of bones and other tissues. Excessive IGF-1 levels in the body may lead to the abnormal growth of the soft tissues and skeletal system.

4Complications

Early treatment of acromegaly is important. If it’s left untreated, it may lead to serious complications such as:

  • Type 2 diabetes
  • High blood pressure
  • Cardiovascular disease
  • Cardiomyopathy
  • Osteoarthritis
  • Bowel polyps
  • Goiter
  • Sleep apnea
  • Carpal tunnel syndrome
  • Uterine fibroids
  • Hypopituitarism or reduced secretion of other pituitary hormones
  • Loss of vision
  • Spinal cord compression

5Risk Factors

Acromegaly can start at any time after puberty. The disease happens more often in middle adulthood, especially because the symptoms progress gradually. Sometimes, people are not aware that they have the condition and the changes in the body occur very slowly that they may take years to become noticeable.

Past history of pituitary humor – People who previously had pituitary tumors are more likely to develop acromegaly if the tumor recurs or when the secretion of the hormones is still not controlled.

The other risk factors include lung neoplasms, adrenal tumors, and pancreatic tumor.

6Diagnosis

Initially, the diagnosis of the condition is done through a series of tests. The doctor may start with a physical examination and an interview of medical history. The other diagnostic tests include:

Blood tests – If the doctor suspects acromegaly in a patient who manifests the symptoms, blood tests are requested to see the level of GH in the body.

  • GH and IGF-1 measurement – This test entails fasting overnight and the doctor will take a blood sample to measure the levels of these hormones in the body. Having high levels would signal acromegaly.
  • Growth hormone suppression test – This is a confirmatory test to diagnose acromegaly. The blood levels of GH are measured before and after the patient drinks a glucose solution.

Imaging tests – The doctor will request for imaging tests to determine the location and size of the pituitary tumor. One of the most commonly used imaging tests is the magnetic resonance imaging. Sometimes, if there is no pituitary adenoma, doctors will look for non-pituitary tumors that can cause the condition.

7Treatment

The treatment of acromegaly aims to reduce the excess levels of the growth hormones to normal amounts, treat hormonal deficiencies, improve the symptoms of the disease, relieve the pressure of the tumor in the adjacent structures in the brain and prevent the occurrence of certain complications.

Surgery – A brain surgery is usually performed if the tumor is big enough that is causes increased pressure in the surrounding structures in the brain. Surgery is effective in most people and it is done usually under a general anesthesia.

The doctor will make the incision inside the nose or behind the upper lip to access the gland. An endoscope is used to visualize the organ and to provide light. Miniature surgical instruments are passed through the incision to remove the adenoma in the pituitary gland.

When the tumor is removed, it will relieve the pressure on the adjacent parts. Also, it will reduce the levels of the hormones to normal. The physical symptoms like swelling and facial appearance will improve over a few days after surgery.

There are possible complications of brain surgery such as meningitis or the inflammation of the meninges, and the leakage of cerebrospinal fluid.

However, in some cases, the doctor can’t remove the entire tumor and this may result in a persistently increased GH levels after surgery. The patient may need medical or radiation therapies for the tumor to disappear completely.

Medical therapy

  • Dopamine agonists – These drugs like bromocriptine (Parlodel) and cabergoline are taken orally once or twice a week and this can suppress the production of growth hormone in the pituitary gland. However, this treatment may not work in other patients. In some patients, these drugs can lower the levels of IGF-1 and GH and the tumor may decrease in size. While in others, the drugs may cause the patient to have compulsive behaviors like gambling when taking these medications.
  • Somatostatin analogues – The drugs in this class, including lanreotide (Somatuline Depot) and octreotide (Sandostatin), are synthetic versions of somatostatin, a brain hormone. They can help reduce the levels of GH in the body. These drugs are given by an injection under the skin or into the muscle once a month. These control the levels of the hormones and eventually lead to the shrinkage of the tumor in some people.
  • Growth hormone antagonist – The medicine in this class, pegvisomant (Somavert), is a growth hormone antagonist. This means that it blocks the effect of the growth hormone and can improve the symptoms. Consequently, it helps lower IGF-1 levels too, but not the growth hormone levels. The drug is administered by the patient daily by subcutaneous injection.

Radiotherapy – If the surgery in the patient can’t be done, or the medication can’t cure the condition, the last option is radiotherapy. The process involves the destruction of any existing tumor cells. Eventually, the levels of the GH will decrease. However, for this treatment, it may take years before the improvement of the symptoms will be noticeable. There are three types of radiotherapy:

  • Conventional therapy – This type of radiotherapy is aimed where the tumor is. External beams are targeted to this area. It’s usually given every weekday over a period of four to six weeks. The full effects of this type of treatment may take for 10 or more years of the therapy.
  • Stereotactic radiosurgery – This type is precisely aimed at the tumor. The patient is required to wear a head frame to keep the head in one position. This also minimizes the risk of damage to nearby healthy tissue.
  • Proton beam therapy – Proton beam therapy delivers a targeted and high dosage of radiation to the tumor. This spares the exposure to normal tissues.

Radiotherapy has many side effects. The treatment may cause a gradual decrease in the levels of the other hormones produced by the pituitary gland.

8Outlook

The treatment for acromegaly is often effective in reducing and blocking the excessive production of growth hormones. Also, the treatment may reduce the risk of the person developing serious complications.

Though some individuals may improve and become cured of the disease through treatment, some therapies may take longer to become effective. However, the treatments have been linked to an increase in the life expectancy of people with the disease.