Type 1 Diabetes Increases Risk of Other Autoimmune Diseases

Type 1 diabetes (T1D) is prevalent, with the CDC estimating that 1.7 million adults and 304,000 children and adolescents in the United States have the disease.¹ It is also one of the most burdensome diseases to manage in daily life; at least 42 factors affect blood glucose levels, with polls indicating that at least one-third of patients’ daily choices are affected by diabetes.^2,3 T1D can also cause long-term complications, including diabetic retinopathy, nephropathy, neuropathy, cardiovascular disease, cardiomyopathy, foot complications, skin conditions, gum disease, and depression.⁴

Type 1 diabetes can cause long-term complications, including the development of autoimmune diseases. | Image Credit: Sherry Young - stock.adobe.com

Yet another challenge for patients with T1D is their increased risk for other comorbid autoimmune diseases, with study data showing that an estimated one-fifth of individuals with T1D have at least 1 comorbid autoimmune condition.^5,6

“Hypothyroidism, celiac disease, autoimmune gastritis, vitiligo, hyperthyroidism, and adrenal insufficiency are diseases with increased frequency in [individuals] with type 1 diabetes,” Jason Gaglia, MD, MMSc, an assistant professor of medicine at Harvard Medical School, said in an interview. “This is likely due to the genetic underpinnings of each of these diseases—shared risk genes that impact immune function and increase chances of autoimmunity.”

In addition to these diseases, “Addison disease, pernicious anemia, rheumatoid arthritis, lupus, and alopecia areata are [also] autoimmune conditions that people with T1D are predisposed to,” Mindy P. Griffith, MD, chief of the Division of Endocrinology at Jersey City Medical Center, said in an interview. “Shared common genetic markers, an overactive immune system, environmental triggers, and molecular mimicry—immune cells that target β cells in T1D may crossreact with other tissues—all contribute to this predisposition.”

It can be particularly complicated when a patient with T1D develops a condition that affects their insulin resistance or complicates diabetes management.

“A number of conditions can increase insulin resistance,” Gaglia, codirector for Clinical Translation Research Core, part of the Joslin Diabetes Center, said. “It is now recognized that people can have features of both type 1 and type 2 diabetes and may need treatment for both diseases.”

“Autoimmune disease, infections, complications of poor glycemic control— gastroparesis, chronic kidney disease, retinopathy—mental health disorders, medications—steroids, β-blockers, atypical antipsychotics—pregnancy, physical inactivity, poor diet, and age-related changes can complicate and worsen glycemic control in T1D,” Griffith said.

“Less common conditions associated with insulin resistance include Cushing syndrome, acromegaly, and pheochromocytoma,” Gaglia added.

In addition to underlying genetics and cellular activity increasing the risk for comorbid autoimmune diseases, stress and environmental triggers can contribute to their development as well.

“There is evidence-based literature suggesting a correlation between stress and/or other life circumstances (trauma, socioeconomic factors) with the predisposition, development, and/or exacerbation of autoimmune disorders,” said Griffith.

Gaglia also added, “Similarly, posttraumatic stress disorder has been associated with increased risk of autoimmune diseases. Such effects may be due to direct effects on the immune system or increasing demand on potentially impacted tissues or organs, such as increased cortisol, increasing insulin requirements.”

This leads to questions of whether a circular loop of stress from the disease itself can contribute to the development of more autoimmune disorders, how trauma and psychology affect disease development, and whether other patterns exist concerning who develops autoimmune diseases and why.

The most common patterns Griffith sees in her practice regarding T1D and comorbid conditions include “a high prevalence of autoimmune thyroid disorders and…celiac disease.” Gaglia also added that “most autoimmune diseases are more common in women than in men.”

The reasons for gender differences in autoimmune diseases are still not widely understood in mainstream Western medicine. However, physicians are exploring the psychology and cultural conditioning that may be at the root of many autoimmune disorders, including the best-selling author Gabor Maté, MD.^7,8 Clinicians may be able to help patients better understand, prevent, or manage their diseases by taking a holistic look at their medical and psychological history and encouraging them to get help in these areas.

In addition to getting psychological help for their diseases and other life stressors, patients can also make positive changes to their health, minimize complications, and potentially prevent the development of more autoimmune diseases by “eating a healthy diet, exercising regularly, maintaining a regular sleep schedule, maintaining a healthy weight, avoiding environmental toxins, [reducing] stress, [receiving] regular medical checkups, and not smoking,” said Gaglia. “Patient education around autoimmune disease risk is important.”

“In individuals with T1D, while there is no evidence-based approach to prevent[ing] additional autoimmune conditions, adopting a healthy lifestyle and staying vigilant regarding new symptoms can help mitigate risks,” Griffith said. “Clinicians should emphasize the importance of overall health and well-being through routine care, screening, patient education, and proactive management.”

Research into curing and preventing T1D is still very new, with most research and treatment thus far focused on managing the disease. However, “research is ongoing and rapidly evolving as it relates to the field of autoimmune disease. There are emerging therapies, including but not limited to biologics, stem cell therapies, and microbiome-based treatments,” Griffith said.

“We are starting to develop therapies that directly target the autoimmunity, and in diseases for which those therapies are available, presymptomatic and early screening should be considered (eg, teplizumab in presymptomatic T1D),” added Gaglia. Clinicians may be able to advise their patients who are at risk before they get the disease, but there is an important balance to be struck regarding whether to advise being screened for diseases in advance.

“Once someone has one autoimmune disease, it is important to be on the lookout for other autoimmune diseases, but keep in mind the implications of the autoimmunity itself vs symptomatic or clinical end-organ disease,” Gaglia said. “Just because someone has evidence of autoimmunity, via autoantibody testing, for example, depending upon the specifics, [this] may not mean clinical disease that warrants treatment is occurring at that moment. Autoimmunity may wax and wane over time. In the case of autoimmunity targeting endocrine organs, it is only when there is insufficient hormone(s) being produced that replacement therapy is undertaken. Indiscriminate testing without appropriate context and explanation can lead to anxiety, which can itself be harmful.”

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REFERENCES

1. National Diabetes Statistics Report. CDC. May 15, 2024. Accessed March 9, 2025. https://www.cdc.gov/diabetes/php/data-research/index.html

2. Brown A. 42 factors that affect blood glucose?! a surprising update. The diaTribe Foundation. February 13, 2018. Updated September 29, 2022. Accessed March 9, 2025. https://diatribe.org/diabetes-management/42-factors-affect-blood-glucose-surprising-update

3. Turrill K. TRAPPED: More than half of adults with ‘relentless’ condition say it stops them being spontaneous. Sun. February 10, 2025. Accessed March 9, 2025. https://www.thesun.co.uk/health/33292390/type-1-diabetes-stops-being-spontaneous/

4. Complications of type 1 diabetes. NHS. Updated October 31, 2024. Accessed March 9, 2025. https://www.nhs.uk/conditions/type-1-diabetes/complications/

5. Samuelsson J, Bertilsson R, Bülow E, et al. Autoimmune comorbidity in type 1 diabetes and its association with metabolic control and mortality risk in young people: a population-based study. Diabetologia. 2024;67(4):679-689. doi:10.1007/s00125-024-06086-8

6. Mäkimattila S, Harjutsalo V, Forsblom C, Groop PH; FinnDiane Study Group. Every fifth individual with type 1 diabetes suffers from an additional autoimmune disease: a Finnish nationwide study. Diabetes Care. 2020;43(5):1041-1047. doi:10.2337/dc19-2429

7. 80% of all autoimmune diseases happen to women. Mel Robbins. YouTube. November 22, 2024. Accessed March 9, 2025. https://www.youtube.com/watch?v=X2Bgpl4wYvs

8. When the body says no: the cost of hidden stress. Dr. Gabor Maté. 2025. Accessed March 9, 2025. https://drgabormate.com/book/when-the-body-says-no/