Thyroid Disease, Celiac Disease, and Other Co-travellers with Type 1 Diabetes

Type 1 diabetes affects about three out of a thousand Canadians. It typically develops in younger people but can occur at any age. It is an autoimmune disease which means it develops because a person’s immune system attacks their insulin-producing cells in the pancreas. The damage eventually eliminates the ability of that person to make insulin, requiring them to take insulin injections to maintain their health. Reasons why the immune system turns against that person’s insulin-producing cells are not completely understood. We do know that they are related to genetics and may be triggered by something in the environment. This incomplete understanding means that it is impossible to know whether an individual with certain genetic factors will or will not develop the autoimmunity that leads to type 1 diabetes.

What we do know, however, is that people who develop type 1 diabetes are also prone to developing a few other autoimmune diseases that can cause symptoms and affect blood sugar control. These include thyroid disease and celiac disease (the most common) as well as Addison’s disease (in which the body doesn’t make enough cortisol), pernicious anemia (in which the body does not absorb vitamin B12), and vitiligo (in which the body’s immune system attacks the pigment cells of the skin leading to areas of depigmentation). Thyroid disease and celiac disease are discussed in more detail below.

The thyroid gland is situated in the neck and makes thyroid hormone. This hormone controls how fast a person’s cells burn energy. When the thyroid is damaged by autoimmune disease it typically stops producing thyroid hormone. This leads to a condition called hypothyroidism. This is the most common result of autoimmune thyroid disease and typically causes symptoms such as low energy, small amounts of weight gain and sensitivity to cold. Less commonly, the damaged thyroid gland can make excess thyroid hormone. This causes hyperthyroidism, which can lead to weight loss and affect concentration and mood. Most physicians screen for thyroid disease every year in people with type 1 diabetes. If a person with type 1 diabetes is feeling different than usual or develops new symptoms, it is always important to check for any thyroid disease. Once diagnosed, both hypothyroidism and hyperthyroidism are usually fairly easy to treat.

Celiac disease occurs when the body’s immune system attacks a component of food called gluten. The inflammation that happens in response to this attack damages the lining of the gut or intestine. This can cause symptoms such as changes in bowel habits, stomach cramps, or other non-specific symptoms. Clinicians often check for celiac disease if a person with type 1 diabetes complains of symptoms such as these. Once diagnosed, it usually responds to a gluten-free diet.

In summary, people with type 1 diabetes are susceptible to several other autoimmune diseases. The challenge is to think about these whenever new symptoms emerge. Once diagnosed, the available therapies usually work well.

About the author

Hertzel Gerstein

Hertzel is an endocrinologist and professor at McMaster University who is in high demand as a speaker, advocate, and educator on diabetes-related topics. His research focuses on using large, international randomized trials to identify and test new ways of preventing type 2 diabetes, reducing serious health outcomes like strokes and death, and achieving type 2 diabetes remissions.