Overview

Acromegaly is a rare hormonal disorder characterized by excessive growth hormone (GH) production in the body, typically due to a benign tumor in the pituitary gland known as a pituitary adenoma. The condition causes abnormal enlargement of bones and tissues, especially noticeable in the hands, feet, and facial features. Because the onset of acromegaly is gradual, it often goes undiagnosed for years. If left untreated, acromegaly can lead to severe health complications, including diabetes, high blood pressure, cardiovascular disease, and joint problems. Early diagnosis and appropriate treatment can significantly improve quality of life and reduce the risk of complications.

Causes

The primary cause of acromegaly is the overproduction of growth hormone, most commonly due to a noncancerous tumor in the pituitary gland. The main causes include:

• Pituitary Adenomas: Around 95% of acromegaly cases are caused by benign tumors in the pituitary gland, which secrete excess growth hormone.
• Non-Pituitary Tumors (Ectopic Acromegaly): Rarely, tumors in other parts of the body, such as the lungs, pancreas, or adrenal glands, produce growth hormone-releasing hormone (GHRH), stimulating the pituitary gland to release more GH.
• Genetic Syndromes: Certain genetic conditions, such as Multiple Endocrine Neoplasia type 1 (MEN1), may increase the risk of developing pituitary tumors.

Overall, the most common and significant cause remains a pituitary adenoma, which disrupts the normal hormonal balance and leads to characteristic changes in body structure and function.

Symptoms

Acromegaly develops slowly, and symptoms may not be obvious in the early stages. As the disease progresses, characteristic physical and systemic changes appear, including:

• Enlarged Hands and Feet: Patients may notice that rings no longer fit and shoe sizes increase.
• Facial Changes: Coarsened facial features, including protruding jaw (prognathism), enlarged nose, thickened lips, and pronounced brow ridge.
• Skin Changes: Thickened, oily skin with excessive sweating (hyperhidrosis).
• Joint Pain: Arthritis and joint stiffness due to abnormal bone and cartilage growth.
• Voice Changes: Deepening of the voice caused by enlarged vocal cords and sinuses.
• Sleep Apnea: Interrupted breathing during sleep due to soft tissue swelling around the airway.
• Headaches: Common due to pressure effects of the pituitary tumor.
• Visual Disturbances: Tumor growth can compress the optic nerves, leading to vision problems, especially peripheral vision loss.
• Fatigue and Weakness: General tiredness due to metabolic imbalances.
• Metabolic Problems: Increased risk of type 2 diabetes, insulin resistance, high blood pressure, and cardiovascular issues.

Diagnosis

Diagnosing acromegaly involves a combination of clinical evaluation, biochemical tests, and imaging studies:

• Medical History and Physical Examination: A doctor examines typical physical changes and asks about progressive changes in appearance, headaches, or vision issues.
• Growth Hormone Testing: Elevated levels of growth hormone in blood samples are indicative of acromegaly.
• IGF-1 Levels: Insulin-like Growth Factor 1 (IGF-1) is consistently elevated in acromegaly and reflects overall GH activity in the body.
• Oral Glucose Tolerance Test (OGTT): In healthy individuals, GH levels decrease after glucose intake. In acromegaly, GH levels remain high.
• MRI Scan of the Pituitary Gland: Magnetic Resonance Imaging helps identify and locate pituitary adenomas, the most common cause of acromegaly.
• Visual Field Testing: Eye tests are conducted to assess if the tumor is affecting vision.
• Additional Tests: In some cases, tests for other pituitary hormones or imaging for ectopic tumors may be necessary.

Treatment

The goal of treatment in acromegaly is to reduce growth hormone production to normal levels, relieve pressure symptoms, and prevent complications. The primary treatment options include:

• Surgery:
  • Transsphenoidal Surgery: The most common approach where the pituitary tumor is removed through the nose using minimally invasive techniques. This can normalize GH levels in many cases.
• Medications:
  • Somatostatin Analogs (e.g., octreotide, lanreotide): Reduce GH secretion.
  • Growth Hormone Receptor Antagonists (e.g., pegvisomant): Block the action of GH in the body.
  • Dopamine Agonists (e.g., cabergoline): May be effective in some cases, especially with mild disease.
• Radiation Therapy:
  • Used when surgery and medications do not fully control the condition. Radiotherapy may take years to achieve full effect but helps reduce hormone levels.
• Ongoing Monitoring: Regular follow-up with hormone level tests and MRI scans to monitor for recurrence or progression.

Prognosis

The prognosis of acromegaly depends largely on the success of early diagnosis and treatment. With effective management, many patients can achieve normal hormone levels and significantly improve their symptoms. Specific considerations include:

• Successful Surgery: Many patients experience significant improvement after surgery, though some may need medications or radiation therapy afterward.
• Quality of Life: Effective treatment can relieve symptoms like joint pain, headaches, and sleep apnea, improving overall well-being.
• Complications: If untreated, acromegaly increases the risk of life-threatening conditions such as cardiovascular disease, diabetes, and respiratory disorders, which can reduce life expectancy.
• Long-Term Outlook: With appropriate therapy and regular monitoring, life expectancy can approach that of the general population.

Overall, early recognition and prompt treatment of acromegaly are key to minimizing complications and allowing patients to lead healthier, more active lives.