Acromegaly

Acromegaly is a disease caused by excessive secretion of growth hormone (somatotropin) by the anterior lobe of the pituitary gland. The disease affects adults in whom the process of bone growth has been completed. In children, in whom the growth process has not been completed, excessive secretion of somatotropin causes gigantism.

 Acromegaly is a rare disease, occurring on average among 3-4 people per million. In Poland, there are an estimated 2,000 cases of acromegaly.

Symptoms

Due to excessive amounts of growth hormone and disturbed hormone metabolism, there’s overgrowth of bones and tissues, resulting in many dangerous changes in the body.

The most characteristic symptoms of acromegaly are:

• Overgrowth of the feet and hands – this is the first visible, most characteristic symptom, requiring a change in the size of shoes, gloves or rings
• Proliferation of soft tissues – initially of the nose, and then of the jaw, auricles, supraorbital shafts and tongue, which can result in difficulty speaking and sleep apnea
• Hypertrophy, deformation and pain in bones and joints
• Enlargement of internal organs
• Muscle hypertrophy
• Hypertension and cardiovascular disease caused by cardiac hypertrophy
• Excessive sweating
• Skin thickening and hair growth
• Type II diabetes with insulin resistance
• Hyperthyroidism
• Changes in the nervous system causing headaches or paresis of the wrist (carpal tunnel syndrome)
• Visual dysfunction, restricted visual fields
• Potency disorders, reduced libido
• In women, menstrual disorders, absence of menstruation, galactorrhea
• Changes in the digestive system – constipation, colon polyps
• Kidney stones
• Initial changes in external appearance progress slowly (take several years), so they may not be visible to the patient at first.

Causes of acromegaly

The main cause of acromegaly is a benign pituitary tumour (adenoma), which, by exerting pressure on the anterior lobe of the pituitary gland, causes more growth hormone to be secreted. Growth hormone leads to the liver’s production of growth factors, mainly insulin-resistant growth factor (IGF-1).

Contrary to belief, twice as many women as men suffer from acromegaly. Unfortunately, ways to prevent the onset of acromegaly are currently unknown.

Diagnosis and treatment

If you notice symptoms, you should see an endocrinologist for proper diagnosis. The tests used to diagnose acromegaly are insulin-like growth factor (IGF-1) assay, serum growth hormone test and growth hormone inhibition test after glucose administration.

An MRI or CT scan is then performed to visualise the tumour, assessing its exact location and size. Depending on the size of the tumour, there may be characteristic symptoms – for example, large tumours (macroadenomas), which are the most common diagnosis in people with acromegaly, can cause headaches and visual disturbances.

Currently, the most effective method of treatment is surgical removal of the tumour. In most cases, surgery is performed without opening the skull, using endoscopic methods – through the nose and wedge sinus. Unfortunately, in the case of macroadenoma, additional treatment or re-surgery is necessary.

The most commonly used drugs are somatostatin analogs, which lower the level of growth hormone and, as a result, reduce the size of the tumour. If this method is not effective, dopaminergic drugs, growth hormone receptor antagonist therapy or radiation therapy are included. Today’s medical capabilities make it possible to fully cure patients with acromegaly, and current clinical trials are being conducted to improve current methods.