Could Graves' disease raise the risk of other autoimmune conditions?

Q. Are people with Graves' disease more prone to developing other autoimmune problems?

A. Yes, there is evidence that people with Graves' disease tend to develop more autoimmune problems than people without Graves’ disease. According to one study, nearly 17% of people with Graves' disease have at least one other autoimmune disease; that’s about three times the rate found in the general population.

An autoimmune disease is one that occurs when the immune system attacks and damages normal body tissues.

In people with Graves' disease, the immune system produces abnormal antibodies that stimulate the thyroid gland. This leads to excess thyroid hormone. Symptoms include anxiety, tremulousness, weight loss, and a decreased tolerance for heat. In addition, some people with Graves' disease develop eye problems (double vision, irritation, bulging of or swelling around the eyes), or a lumpy, thickened area over the shins (called pretibial myxedema).

Other autoimmune conditions thought to be associated with Graves' disease include:

• Chronic autoimmune (Hashimoto's) thyroiditis. An immune attack on the thyroid can damage the gland, eventually leading to a reduction in the gland's function and low thyroid hormone levels (a condition called hypothyroidism).
• Type 1 diabetes. The immune system attacks the insulin-producing cells of the pancreas, leading to inadequate insulin and increased blood sugar.
• Pernicious anemia. This condition may develop when the immune system attacks stomach cells that produce intrinsic factor (a protein needed to absorb vitamin B₁₂). Or the immune system may directly attack intrinsic factor. Either way, the resulting B₁₂ deficiency may lead to anemia and nerve problems.
• Vitiligo. An immune attack on skin cells leads to loss of pigment in patches of skin.
• Rheumatoid arthritis. The target of immune attack is the lining of joints (called synovium); other organs can be affected, including the eyes, lungs, and heart.
• Multiple sclerosis. Damage to myelin, the protective coating of nerve cells, causes interruption of nerve signals. This leads to a host of neurologic symptoms such as vision problems, muscle weakness, and poor balance.

People with Graves' disease should have regular checkups to monitor the thyroid gland and, when appropriate, to check for the development of other autoimmune diseases.

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