When it’s more than T1D

April 23, 2024

Many people know that type 1 diabetes is an autoimmune condition, but what you may not know is that autoimmune conditions sometimes come in multiples. Some are more commonly associated with type 1 diabetes than others, but most can affect blood glucose levels – especially if undiagnosed. Here are some of the most common conditions that coexist with T1D.

Hypothyroidism is when the thyroid gland, found in your neck and responsible for metabolism, among other things, does not make enough thyroid hormones.1
Symptoms: Weight gain, fatigue, cold intolerance, body aches, thinning hair, dry skin, depression, and even slowed heart rate. These symptoms can develop slowly, and the most common cause is an autoimmune condition known as Hashimoto’s disease or Hashimoto’s Thyroiditis.
Treatment: Typically treated relatively easily with oral thyroid hormone supplements. However, getting the correct dose can be tricky and will change across the lifespan.
Diagnosis: Both children and adults with type 1 diabetes should be screened yearly for hypothyroidism by getting laboratory measurements of thyroid-stimulating hormone (TSH) according to the American Diabetes Association’s Standards of Care in Diabetes.
Incidence with T1D: In a 2022 study, 16.1% of 13,570 adults with type 1 diabetes in the Mediterranean region were diagnosed with thyroid disease, making it the most common co-existing condition in this cohort.2 Another Finnish study from 2020 had similar results: 18.1% of almost 5,000 people with T1D also had hypothyroidism, again, the highest-ranking second autoimmune condition.3

Hyperthyroidism is the opposite of Hypothyroidism, where the body makes too much thyroid hormone. It is often caused by Grave’s Disease, which is autoimmune hyperthyroidism.4
Symptoms: Anxiety, sensitivity to heat, weight loss, an enlarged thyroid gland (goiter), frequent bowel movements, sleep disturbances, and bulging eyes.
Treatment: More complex than hypothyroid and can involve anti-thyroid medication, radioactive iodine therapy, or surgical removal of the thyroid gland.
Diagnosis: Laboratory test of thyroid hormones, typically TSH and T4.
Incidence with T1D: Though much less common than hypothyroidism, it still co-exists with T1D at low levels, around 1%2

Celiac Disease
Celiac disease is an allergy to gluten, which is found in wheat, rye, and barley.
Symptoms: When someone with celiac consumes gluten, it causes bloating, excess gas, diarrhea, vomiting, abdominal pain, and a rash called Dermatitis Herpetiformis. If untreated, it can lead to more severe problems such as weight loss, vitamin deficiencies, anemia, fatigue, and even osteoporosis. Some people with celiac disease have no symptoms, making it more tempting to consume gluten.
Treatment: Treatment is often difficult for those sensitive to gluten, as cross-contamination is very common. Ideally, people with celiac disease avoid gluten in all foods and other products, such as some makeup, dental products, and Play-Doh, and will not have any symptoms. In addition to the risks above, untreated celiac disease can damage the intestines and cause variability in blood glucose levels for people with diabetes, especially after meals.
Diagnosis: Laboratory test of antibodies to gluten, then biopsy of the small intestine for conclusive diagnosis.
Incidence: Celiac disease is something we hear about often as relating to type 1 diabetes, but the population studies out of Finland and the Mediterranean have relatively low incidences. In the Finland cohort, only 1.5% of people with T1D had celiac, while in the Mediterranean cohort, it was 1.6%.

Atrophic Gastritis
Atrophic gastritis is inflammation and thinning of the lining of the stomach.5 It can be caused by autoimmune disorders, infection by H. Pylori, and environmental factors that lead to chronic inflammation.
Symptoms: Some people don’t have any symptoms with either type of gastritis (autoimmune or environmental). Environmental-type symptoms include abdominal pain, nausea and vomiting, decreased appetite, peptic ulcers, iron-deficiency anemia, and unexplained weight loss. Autoimmune-type symptoms include chest pain, dizziness, confusion, nausea and vomiting, increased heart rate, ringing in the ears, and palpitations.
Treatment: Environmental type: medications to reduce acid and antibiotics to treat H. Pylori. Autoimmune type: iron or vitamin B12. For either type, monitoring for gastric cancer is essential because having atrophic gastritis increases the risk.
Diagnosis: Blood tests including iron, vitamin B12, gastrin, pepsinogen, and other antibodies. May perform endoscopy and biopsy as well.
Incidence with T1D: Typically around 0.9 – 1%2,3 in people with T1D.

Vitiligo is characterized by loss of pigment or color in the skin. It typically results in white patches of skin on the body.
Symptoms: patches of white or lighter skin on the body, usually on hands, feet, arms, and face. Sometimes, this can lead to the development of uveitis, which is inflammation in the eye.
Treatment: Light therapy, medicated skin creams, and other possibilities depend on the extent of depigmentation. Protecting the skin with sunscreen is also very important.
Diagnosis: Skin biopsies can show decreased melanocytes (cells that create skin pigment).
Incidence with T1D: 1.2%2

This condition causes skin cells to replicate more than usual, which creates scaly, inflamed, and reddened skin.6 It can occur on any body part but usually affects the scalp, knees, and elbows.
Symptoms: Scaly skin patches typically itch or may burn.
Treatment: There are a variety of creams, lotions, ointments, and shampoos for psoriasis on the scalp. In more severe cases, you can take immunosuppressive medications like methotrexate or biologics.
Diagnosis: Skin biopsy or visual assessment.
Incidence with T1D: 2.7%-9%2,3

This is by no means an exhaustive list, but it includes some of the most common conditions that tend to co-exist with T1D. Some other common conditions that co-exist with T1D are Multiple sclerosis, Addison’s disease, Rheumatoid arthritis, Lupus, and Sjögren syndrome. Check with your healthcare team about what screenings make sense for you.

  1. Hypothyroidism (Underactive Thyroid)
  2. Comorbid autoimmune diseases and burden of diabetes-related complications in patients with type 1 diabetes from a Mediterranean area
  3. Every Fifth Individual With Type 1 Diabetes Suffers From an Additional Autoimmune Disease: A Finnish Nationwide Study
  4. Graves’ disease
  5. Atrophic Gastritis
  6. Psoriasis

Written and clinically reviewed by Marissa Town, RN, BSN, CDCES