Type 1 Diabetes Poses Risk of Thyroid Disease
Link between 'sister diseases' is rooted in immune system problem, expert says
By Serena Gordon
FRIDAY, March 15 (HealthDay News) -- People who have type 1 diabetes are more likely than others to develop an autoimmune thyroid condition.
Though estimates vary, the rate of thyroid disease -- either under- or overactive thyroid -- may be as high as 30 percent in people with type 1 diabetes, according to Dr. Betul Hatipoglu, an endocrinologist with the Cleveland Clinic in Ohio. And the odds are especially high for women, whether they have diabetes or not, she said, noting that women are eight times more likely than men to develop thyroid disease.
"I tell my patients thyroid disease and type 1 diabetes are sister diseases, like branches of a tree," she said. "Each is different, but the root is the same. And, that root is autoimmunity, where the immune system is attacking your own healthy endocrine parts."
Hatipoglu also noted that autoimmune diseases often run in families. A grandparent may have had thyroid problems, while an offspring may develop type 1 diabetes.
"People who have one autoimmune disease are at risk for another," explained Dr. Lowell Schmeltz, an endocrinologist and assistant professor at the Oakland University-William Beaumont School of Medicine in Royal Oak, Mich.
"There's some genetic risk that links these autoimmune conditions, but we don't know what environmental triggers make them activate," he explained, adding that the antibodies from the immune system that destroy the healthy tissue are different in type 1 diabetes than in autoimmune thyroid disease.
Hatipoglu said that people with type 1 diabetes are also more prone to celiac disease, another autoimmune condition.
Type 1 diabetes occurs when the immune system mistakenly attacks the insulin-producing cells in the pancreas, destroying them. Insulin is a hormone that's necessary for the metabolism of carbohydrates in foods. Without enough insulin, blood sugar levels can skyrocket, leading to serious complications or death. People who have type 1 diabetes have to replace the lost insulin, using shots of insulin or an insulin pump with a tube inserted under the skin. Too much insulin, however, can also cause a dangerous condition called hypoglycemia, which occurs when blood sugar levels drop too low.
The thyroid is a small gland that produces thyroid hormone, which is essential for many aspects of the body's metabolism.
Most of the time, people with type 1 diabetes will develop an underactive thyroid, a condition called Hashimoto's disease. About 10 percent of the time, Schmeltz said, the thyroid issue is an overactive thyroid, called Graves' disease.
In general, people develop type 1 diabetes and then develop thyroid problems at some point in the future, said Hatipoglu. However, with more people being diagnosed with type 1 diabetes in their 30s, 40s and 50s, Schmeltz said, it's quite possible that thyroid disease can come first.