Understanding Acromegaly

Medically Reviewed By Kelly Wood, MD
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Acromegaly occurs when a body produces too much growth hormone. An excess of this hormone can cause organs, cartilage, bones, and tissues to grow larger. The National Center for Advancing Translational Science estimates there may only be 300–3,000 people with acromegaly in the United States.

This article examines this rare disease’s symptoms, diagnosis process, and treatments. 

Sex and gender disclaimer

Sex and gender exist on a spectrum. This article uses the terms “female” and/or “male” to refer to sex that was assigned at birth. 

Learn more about the difference between sex and gender here.

What is acromegaly? 

Female hands
Nicholas Roberts/Stocksy United

Acromegaly is a progressive disorder in which the pituitary gland produces extra growth hormones. In most cases, doctors can treat the condition. Cases that progress without treatment can lead to other health issues, such as heart disease or sleep apnea. 

This disease presents itself in different ways. Some people may notice their feet and hands increasing in size. Others may experience extra body hair growth and excessive skin tags. Some people may develop a goiter or enlarged adrenal glands. 

Acromegaly vs. gigantism

Acromegaly primarily impacts middle-aged adults. However, a similar condition can occur in children, which is giantism.

Gigantism is a disease that causes a child’s body to produce too much growth hormone before puberty. The most common cause of gigantism is a benign tumor on the pituitary gland. Since gigantism occurs before a child’s growth plates close, the condition causes them to grow tall. 

What are the symptoms of acromegaly?

Acromegaly symptoms manifest in many different ways. As a person with acromegaly ages, the symptoms may appear more prominently. 

Common symptoms include: 

  • protruding lower jaw, known as prognathism
  • gradual enlargement of hands and feet
  • large cartilages that cause joint stiffness
  • spleen, liver, kidney, intestines, and thyroid gland enlargement
  • headaches
  • vision abnormalities
  • hypertension
  • increased metabolic rate
  • excessive sweating 

Some symptoms of acromegaly differ between males and females (assigned at birth). In males, acromegaly may manifest as decreased libido. Females with the condition may experience abnormal breast milk production, known as galactorrhea. However, this only occurs if the tumor produces another hormone called prolactin. Acromegaly may also cause delayed menstrual cycles. 

Acromegaly can cause health complications that lead to other conditions, such as heart disease and arthritis.

What are the causes of acromegaly?

According to the National Institute of Diabetes and Digestive and Kidney Diseases, a tumor in the pituitary gland causes more than 9 out of 10 acromegaly cases. In rare circumstances, a tumor in a different part of the body can cause increased growth hormone. 

People who develop a pituitary tumor do not usually have a family history of acromegaly. However, pituitary tumors may be a part of a syndrome due to unusual gene changes. 

Syndromes associated with acromegaly include: 

  • McCune-Albright syndrome: This syndrome occurs from a mutation in the GNAS1 gene. The mutation is not inherited, but the gene change occurs before birth. Symptoms include brown skin patches, called cafe-au-lait spots, and a tumor on the pituitary gland.
  • Carney complex: Many Carney complex cases result from a change in the PRKAR1A gene. This rare syndrome causes heart, skin, and adrenal issues. People with this condition sometimes develop acromegaly. 
  • Multiple endocrine neoplasia type 1: Changes in the MEN1 gene cause this syndrome. A person with multiple endocrine neoplasia type 1 typically passes on the condition to half of their children. This syndrome puts people at high risk for developing tumors on the pituitary glands, parathyroid glands, and pancreas. 

Click here to read more about what the pituitary gland does.

How do doctors diagnose acromegaly?

If you have a family history of acromegaly or one or more symptoms present, your doctor may order blood and imaging tests that can detect acromegaly. 

Doctors use an insulin-like growth factor-1 (IGF-1) test and an oral glucose tolerance test to identify the amount of growth hormone in the blood. If the IGF-1 test comes back elevated, it may suggest that you have acromegaly. 

After the IGF-1 test, your doctor may order an oral glucose tolerance test to confirm the diagnosis. The exam involves drinking a sugary beverage. A health practitioner then tests your blood at half-hour intervals for 2 hours. Sugar typically causes growth hormone blood levels to decrease. If your body is producing too much growth hormone, the level will not decrease enough or at all.

When blood work suggests acromegaly, a doctor will order imaging tests to examine the pituitary glands. An MRI creates detailed images of internal organs. However, some people cannot receive an MRI due to metal implants. In this case, a doctor may suggest a CT scan, which combines X-rays and technology to create an image of the pituitary gland. 

In acromegaly cases, an MRI or CT scan will typically reveal a tumor on the pituitary gland. 

What are the treatments for acromegaly?

Doctors tailor a treatment plan to ease the specific symptoms present. The goal of any treatment plan is to return growth hormone levels to regular levels. Treatment aims to reduce the pituitary tumor’s size and decrease any symptoms you are experiencing.

A medical team often uses a combination of transsphenoidal surgery and medications to remove or shrink the pituitary gland tumor. In some cases, radiation therapy may be necessary. Doctors typically suggest radiation therapy when the size or location of the pituitary tumor or another health condition makes surgery a large health risk.

Radiation therapy may also help if surgery does not remove all of the tumor.

Successful surgery to remove the portion of the tumorous pituitary gland usually results in a fast therapeutic response. You may feel an immediate release in pressure near your brain, and your body may start to decrease growth hormone levels right away. 

Before deciding on a treatment plan, ask your doctor about the risks of each approach. Asking questions can help you make an informed decision on your health. 

After surgery or radiation removal, your doctor will monitor your symptoms to ensure the increase in growth hormone does not occur. In cases of reoccurrence, doctors usually prescribe one of the following medications: 

  • octreotide
  • lanreotide
  • pasireotide
  • pegvisomant
  • dopamine antagonists

What are the potential complications of acromegaly?

Acromegaly may cause other health conditions, including the following:

Acromegaly tumors are usually benign. However, acromegaly may increase a person’s chances of developing some cancer types, such as colorectal cancer

Individuals with acromegaly have an increased risk of developing polyps in the colon. Individuals with acromegaly may also have a slightly greater risk of developing colon cancer than the general population.

Visit our hub to read about heart health.

What is the prognosis for someone with acromegaly?

Acromegaly is treatable in most situations. However, without treatment, the condition can lead to complications that may increase the mortality rate. 

A 20-year follow-up study published in 2016 reveals that males with acromegaly typically receive an earlier acromegaly diagnosis and are younger than females at their time of death.

In general, mortality increased during the 20 years of follow-up, particularly in females. However, the causes of death typically resulted from complications associated with acromegaly, such as cancer and cardiovascular deaths. 

Summary

Acromegaly is a rare condition in which your body produces too much growth hormone. People with this condition may notice their facial features, arms, and hands growing.

Doctors diagnose it using blood tests and medical imaging. Acromegaly can lead to serious health complications without treatment. Treatment involves surgery, medication, and radiation therapy. 

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Medical Reviewer: Kelly Wood, MD
Last Review Date: 2022 May 20
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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