Overview of Acromegaly

Acromegaly is a rare hormonal disorder characterized by the excessive production of growth hormone (GH) by the pituitary gland, a small gland located at the base of the brain. This overproduction of GH leads to the abnormal growth of bones and tissues in the body, particularly in the hands, feet, and face.

One of the hallmark features of acromegaly is the enlargement of facial features such as the nose, lips, and jaw, which can result in a more pronounced and distorted appearance. Additionally, individuals with acromegaly may experience joint pain, enlarged organs, and a range of other health complications, including cardiovascular problems and diabetes.

In this article, we will provide an overview of acromegaly, including its known symptoms, risk factors, and treatment options.

The primary cause of acromegaly often stems from the presence of a benign (non-cancerous) pituitary tumor known as an adenoma. Pituitary adenomas trigger the pituitary gland to generate an overabundance of growth hormone, resulting in abnormal growth of bones and tissues throughout the body.

This tumor can exert pressure on adjacent brain structures, causing symptoms such as visual disturbances and headaches. In more than 90% of acromegaly cases, the continuous secretion of growth hormone originates from these benign pituitary adenomas.

Less commonly, acromegaly can be attributed to tumors located outside of the pituitary gland, such as those found in the pancreas, lungs, or adrenal glands. These tumors produce excessive amounts of growth hormone-releasing hormone, which in turn stimulates the pituitary gland to enhance its growth hormone production.

Acromegaly can present with a number of different symptoms, the most common of which include: 

• Enlarged hands and feet
• Changes in facial features, such as enlarged facial aspects (nose, lips, tongue) and protruding jaw
• Enlarged organs such as the heart, liver, and spleen
• Sweaty, oily skin
• Development of skin tags (small, benign growths)
• Headaches
• Deepening of the voice due to enlarged vocal cords
• Muscle weakness and fatigue
• Joint pain resulting from enlarged organs increasing pressure on the capsule
• Sleep apnea

Acromegaly can sometimes be a component of a genetic disorder. One such condition is Carney complex, a rare genetic disorder characterized by the development of multiple benign tumors, including pituitary adenomas that can result in acromegaly.

Additionally, McCune-Albright syndrome, another rare genetic disorder known for causing abnormal bone growth and skin pigmentation, can also give rise to pituitary tumors and subsequently lead to acromegaly.

If acromegaly goes untreated or is not adequately managed, it can result in a range of complications, spanning from heart disease to arthritis. If you suspect you might have acromegaly or are exhibiting any of these symptoms, it is crucial to seek the guidance of a healthcare provider for a thorough assessment and diagnosis.

There are no established preventive measures for acromegaly. However, early intervention can potentially halt the progression of the condition and mitigate the risk of complications.

Acromegaly and gigantism both result from an excessive production of growth hormone, but they differ primarily in the age group affected. Acromegaly typically manifests in adults, whereas gigantism affects children.

Gigantism arises when a child experiences elevated levels of growth hormone before their growth plates fuse, which typically occurs before the end of puberty. Consequently, they undergo significant height growth; this is the main symptom of gigantism.

Conversely, acromegaly occurs when an excess of growth hormone is present after the fusion of growth plates. In this scenario, further height growth is not possible, but the surplus growth hormone impacts bone structure, organ size, and other aspects of health. In all, people with acromegaly are not tall.

It's important to note that gigantism does not transform into acromegaly. If an individual experiences excessive growth hormone production during childhood, they will develop gigantism, and this condition persists into adulthood because it originated in their earlier years.

As adults, they will continue to be diagnosed with gigantism rather than transitioning to acromegaly.

The diagnosis of acromegaly typically involves a combination of medical history review, physical examination, imaging studies, and laboratory testing. Among the commonly employed laboratory tests, two key assessments are considered the gold standard for diagnosis:

Blood tests are conducted to measure levels of insulin-like growth factor-1 (IGF-1) in the bloodstream. IGF-1 is produced by the liver in response to signals from growth hormone. In individuals with acromegaly, IGF-1 levels are usually elevated, making this test a frequently used diagnostic tool.

To confirm an acromegaly diagnosis, an OGTT may be administered. During this test, the patient consumes a solution containing a known quantity of glucose, with blood samples taken at specific intervals to assess growth hormone levels.

In individuals without acromegaly, growth hormone levels typically decrease after glucose ingestion. However, in those with the condition, growth hormone levels remain elevated.

Acromegaly typically presents in middle-aged adults, between the ages of 30 and 50, although it can occur at any age. Nevertheless, the emergence of symptoms can be gradual, leading to delayed diagnosis, which can extend into a patient's 50s or 60s in some cases.

Notably, certain studies have indicated a higher prevalence of acromegaly among females compared to males. Early detection and intervention are crucial for reducing the likelihood of complications and enhancing long-term prognosis. 

Treatment options for acromegaly encompass surgery, radiation therapy, and medications. The preferred and most effective approach is typically transsphenoidal surgery, a minimally invasive procedure that involves removing the pituitary tumor responsible for excessive growth hormone production through instruments inserted via the nasal passage. Success rates for this treatment range from 70% to 80%.

In cases where complete tumor removal is not achieved, in instances of tumor recurrence, or when surgery is deemed too risky, healthcare providers may recommend radiation therapy or medication-based treatments. Radiation therapy is typically administered using stereotactic radiosurgery, employing precisely targeted radiation beams to shrink the pituitary tumor and impede further growth.

Medications such as somatostatin analogs, dopamine agonists, and growth hormone antagonists can also be employed to lower growth hormone levels or counteract its effects. Patients diagnosed with acromegaly should work closely with their care team, including an endocrinologist (a physician with special training in the management of hormone disorders) and a neurosurgeon to achieve optimal treatment results. 

Acromegaly can be treated and controlled effectively. Timely diagnosis and suitable treatment options can lead to substantial symptom improvement and enhance overall quality of life for people with acromegaly. With proper management, life expectancy can approach a normal level.

However, if the condition is neglected or inadequately addressed, it can raise the likelihood of developing various health complications. Acromegaly can create a range of physical, psychological, and social challenges, so it is important to contact your physician if you are concerned that you might have this disorder.

• Acromegaly is characterized by several distinct features: the abnormal growth of hands and feet, enlargement of facial features, thickened skin, and joint pain.
• The primary cause is a noncancerous pituitary gland tumor known as an adenoma.
• The estimated incidence of acromegaly ranges from approximately 40 to 125 cases per million people.
• Common laboratory tests used for acromegaly diagnosis include measuring IGF-1 levels and conducting an Oral Glucose Tolerance Test (OGTT).
• The preferred treatment method is transsphenoidal surgery.
• Effective management and control of acromegaly are achievable with appropriate treatment.

• Pituitary Network Association: Acromegaly
• The Pituitary Foundation [UK]: Acromegaly
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): Acromegaly
• National Health Service (NHS) [UK]: Acromegaly