A while back, I wrote about hypothyroidism and diabetes. Recently, there was a press release from the American Association of Clinical Endocrinologists (AACE) about Hyperthyroidism: The Flip Side of the Thyroid Equation, and I decided to remind our readers that both hypo- (underactive) and hyperthyroidism (overactive thyroid functioning) are issues for people with diabetes (PWD).
It's been known for years that diabetes and thyroid problems can go hand-in-hand. More specifically, type 1 diabetes, which itself is an autoimmune disorder, is frequently associated with other autoimmune disorders including autoimmune thyroid disorders. These autoimmune thyroid disorders may cause the thyroid to fail (in a disorder called Hashimoto’s thyroiditis, which leads to hypothyroidism), or, sometimes, to become overactive (in a disorder called Graves’ disease, which leads to hyperthyroidism). Both Hashimoto’s and Graves’ will have positive blood tests for thyroid antibodies.
In general, hypothyroidism is far more common than hyperthyroidism, and can occur in both T2DM and T1DM. For more information on hypothyroidism, please see my previous essay. Hypothyroidism can sneak up on people, with symptoms developing so slowly that frequently patients just assume they were growing old prematurely. Symptoms of hypothyroidism, no matter what the cause, include fatigue, dry, coarse skin and hair, inability to tolerate cold weather, weight gain, hoarse voice, and heavy or irregular menstrual periods. Blood levels of thyroid hormone are low and levels of TSH (thyroid stimulating hormone) are typically very elevated. Blood glucose control isn’t changed dramatically, but blood levels of cholesterol will become very elevated (and should return to normal with treatment of the hypothyroidism).
Hyperthyroidism’s symptoms are pretty much the reverse of those seen with hypothyroidism, and they can develop over a short period of time. Symptoms can include rapid heart rate, heart rhythm disturbances and palpitations, tremor, insomnia, anxiety or agitation, sweating, heat intolerance and abnormal ability to tolerate cold weather, weight loss, hair loss, and scant or absent menses. In older patients (older than about 70 years of age), the typical findings may be absent. Blood levels of thyroid hormone are elevated and levels of TSH are depressed. PWD usually also have deterioration of their blood glucose control. Sometimes, people without a prior diagnosis of diabetes may develop hyperglycemia as a result of their revved-up metabolism.
In patients with Graves’ disease, the thyroid gland (which is located in the front of the neck) may become noticeably enlarged (an enlarged thyroid gland is called a "goiter"). Another problem may occur in Graves' disease: there may be swelling of the muscles and tissues around the eyes also may develop, causing the eyes to bulge forward.