Type 1 Diabetes Poses Risk of Thyroid Disease
Link between 'sister diseases' is rooted in immune system problem, expert says
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.
Thyroid problems are often diagnosed through routine annual blood tests, according to both experts.
Untreated thyroid problems can affect blood sugar levels in people with type 1 diabetes. "If I see someone having a lot of trouble controlling their blood sugars, it could be the thyroid," noted Hatipoglu.
"People who are diagnosed with type 1 diabetes often work very hard to control their blood sugar, but if they're not aware of an underactive thyroid, they may have a lot of unexplained low blood sugars," she said. "If someone is hyperthyroid, they may have unexplained high blood sugars."
Sometimes people with type 1 diabetes gain weight from taking insulin, but unexplained weight gain can also be due to an underactive thyroid.
"People really need to be aware that if you have one of these conditions, you're at risk of the other," Schmeltz said. "And, symptoms aren't always so obvious. Someone might be tired a lot and think it's because of diabetes, and they end up ignoring thyroid symptoms."
He said the classic symptoms of an underactive thyroid are decreased energy, hair loss, inappropriate weight gain, feeling cold, constipation, dry skin, heavy periods and difficulty concentrating. Some of the symptoms also overlap with a diagnosis of depression.
Symptoms of an overactive thyroid, which are often mistaken for other conditions, include trouble concentrating, heat intolerance, frequent bowel movements, excessive sweating, increased appetite, unexpected weight loss, restlessness, a visible lump in the throat (goiter), nervousness and irregular menstrual periods, according to the U.S. National Library of Medicine.