Endocrine Disorders Acromegaly

Gentle Giants: Harnessing Growth Hormone

The other class of symptoms associated with acromegaly is due to elevated levels of the growth hormone itself in the blood. And this is what can lead to the enlargement of the hands, the joints and some of the internal organs.

The joint pains may require joint replacements such as hip replacement and that can be terribly painful. Other symptoms include sleep disorders, including sleep apnea syndrome. In addition, patients can have heart disease from a thickened heart leading to shortness of breath, particularly with exercise.

So there can be a whole range of signs and symptoms with acromegaly that can be debilitating.

Is it hard to diagnose acromegaly?
Acromegaly is extremely difficult to diagnose. Patients' growth hormone levels are slowly increasing over the course of many years and the changes are often subtle. Sometimes patients see someone they haven't seen in a long time or a new physician, and that person comments on the changes, whereas patients won't see them day-to-day in the mirror.

In fact, if we look back at patients in terms of their symptoms before diagnosis, we find that patients probably had active acromegaly for at least 10 years prior to diagnosis.

What are the goals for therapy in acromegaly?
There are two major goals for the therapy. One is to reduce the tumor size in order to prevent the complications from the tumor on the brain. The second goal is to lower the growth hormone levels, because it is the growth hormone that circulates through the blood and leads to the changes in the body.

The bony changes of acromegaly, which can be very marked and disfiguring, are usually there to stay. All the soft-tissue stuff—the large hands, the large feet, the thickened heart—can regress in size with appropriate therapy.

What is the normal course of treatment for acromegaly?
The primary mode of therapy is surgery. Surgery leads to the most rapid normalization of growth hormone and decrease in tumor size. We can also use radiation therapy, usually for those patients who have residual tumors after surgery. But after surgery, most patients need therapy using medicines, and there are three main classes of medicines that we can use.

How is surgery used to treat acromegaly?
The surgery that is used for acromegaly is called transsphenoidal surgery, which means that the surgery is performed through the nose. It's a fairly benign surgery in experienced hands, and it can be very successful at decreasing tumor size and growth hormone levels.

The efficacy of surgery is really based on tumor size and location, and this is the problem with acromegaly. Often patients have had the disease for many years before it is diagnosed and the tumors often are quite large at the time of diagnosis, so surgery is successful in approximately half to two-thirds of patients. True surgical success is determined by normalization of the hormone levels.

What types of medications are used to treat acromegaly?
There are two major effects that the medicines have for the treatment of acromegaly. One is to lower the growth hormone levels to improve the signs and symptoms of acromegaly. The other very important effect is to prevent the tumors from either becoming larger or, if possible, to decrease the tumor size. The major classes of medication are somatostatin analogs and dopamine agonists.

One of the new categories of medications for acromegaly is called the growth hormone receptor antagonists. These are molecules that bypass the pituitary tumor altogether. Instead, they circulate in the blood and go everywhere that growth hormone will have its effects and block those effects, leading to improvement in the signs and symptoms of acromegaly.

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