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Understanding
autoimmune
type 1 diabetes

What is autoimmune type 1 diabetes (T1D)?

  • Autoimmune diseases occur when a person’s immune system mistakenly attacks their own body1

  • In autoimmune type 1 diabetes (T1D), the body’s immune system attacks its own insulin-producing cells (also known as beta cells) in the pancreas, leading to insulin deficiency.2,3 Insulin is an essential hormone that helps the body turn food into energy4

  • Autoimmune T1D progresses in stages. In the early stages, T1D develops silently, meaning you could have the condition without noticing any symptoms2,5
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Autoimmune T1D is increasing worldwide

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Every year, more people are diagnosed with autoimmune T1D, with the condition affecting both children and adults.6,7

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Over 9 million people worldwide are living with autoimmune T1D.8

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Autoimmune T1D is one of the fastest-growing autoimmune conditions globally, with numbers rising by approximately 2–3% each year.6

What causes autoimmune T1D?

  • The exact cause of autoimmune T1D is unclear, but it is believed to result from a combination of genetic and environmental triggers, and is not directly linked to diet or lifestyle2,9

  • Certain genes (such as HLA genes) are thought to play a role in increasing the likelihood of developing autoimmune T1D, but not everyone who has them develops the condition.10 It is not clear why some people develop T1D while others with similar genetic backgrounds do not, and research continues to explore why6,11

  • Environmental triggers, including viral infections, changes in the gut microbiome and other unknown factors can initiate the autoimmune process in T1D11
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Autoimmune T1D can be mistaken for prediabetes or type 2 diabetes, especially in adults

  • Did you know that people suspected of having prediabetes or type 2 diabetes (T2D) could actually be living with autoimmune T1D?12,13

  • Prediabetes happens when someone has higher blood sugar than normal, and if not addressed, can develop into T2D.14 But unlike T1D, prediabetes and T2D are not autoimmune conditions2,3,6

  • Autoimmune T1D can look similar to prediabetes or T2D, so it’s important to get clarity on which condition you have10,14

  • Around 40% of adults with autoimmune T1D are initially misdiagnosed, most commonly with T2D12
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You don’t have to be caught off guard by the symptoms of autoimmune T1D

When people are unprepared, the onset of symptoms can be overwhelming for individuals and their families,15–17 disrupting daily routines and making it difficult to plan ahead.18–20 Many individuals find themselves needing to significantly adjust their lifestyles to manage the responsibilities that the condition brings.18,19,21


There is good news though, as detecting autoimmune T1D before symptoms appear can help you and your loved one’s plan ahead.15,22

Learn how T1D is diagnosed early

See more

References

  1. Smith DA, Germolec DR. Environ Health Perspect. 1999;107 (Suppl 5):661-665.
  2. Insel RA, Dunne JL, Atkinson MA, et al. Diabetes Care. 2015;38(10):1964-1974.
  3. Diabetes UK. Differences between type 1 and type 2 diabetes. Available at: https://www.diabetes.org.uk/diabetes-the-basics/differences-between-type-1-and-type-2-diabetes. Accessed April 2025
  4. Cleveland Clinic. Hyperglycemia (High blood sugar). Available at: https://my.clevelandclinic.org/health/diseases/9815-hyperglycemia-high-blood-sugar. Accessed April 2025.
  5. Sims EK, Besser REJ, Dayan C, et al. Diabetes. 2022;71(4):610-623.
  6. DiMeglio LA, Evans-Molina C, Oram RA. Lancet. 2018;391(10138):2449-2462.
  7. Gregory GA, Robinson TIG, Linklater SE, et al. Lancet Diabetes Endocrinol. 2022;10(10):741-760.
  8. Type 1 Diabetes Index. Available at: https://www.t1dindex.org/. Accessed April 2025.
  9. Weires MB, Tausch B, Haug PJ, et al. Exp Clin Endocrinol Diabetes. 2007;115(10):634-640.
  10. Haller MJ, Bell KJ, Besser REJ et al. Horm Res Paediatr. 2024;97(6):529-545.
  11. Bauer W, Gyenesei A, Krętowski A. Int J Mol Sci. 2021;22(14):7493.
  12. Muñoz C, Floreen A, Garey C, et al. Clin Diabetes. 2019;37(3):276-281.
  13. Phillip M, Achenbach P, Addala A, et al. Diabetes Care. 2024;47(8):1276-1298.
  14. Diabetes UK. Prediabetes symptoms and risk reduction. Available at: https://www.diabetes.org.uk/about-diabetes/type-2-diabetes/prediabetes. Accessed April 2025.
  15. Besser REJ, Ng SM, Gregory JW, et al. Arch Dis Child. 2022;107(9):790-795.
  16. Hummel S, Carl J, Friedl N, et al. Diabetologia. 2023;66(9):1633-1642.
  17. Fornasini S, Miele F, Piras EM. J Child Fam Stud. 2020;29:1467-1483.
  18. Chatwin H, Broadley M, Valdersdorf Jensen M, et al. BMJ Open Diabetes Res Care. 2021;9(1):e002322.
  19. van Duinkerken E, Snoek FJ, de Wit M. Diabet Med. 2020;37(4):555-563.
  20. Jönsson L, Lundqvist P, Tiberg I, et al. Scand J Caring Sci. 2015;29(1):126-135.
  21. The price of uncertainty: Unveiling the impact of unexpected type 1 diabetes diagnoses. Available at: https://beyondtype1.org/unexpected-type-1-diabetes-diagnoses/. Accessed April 2025.
  22. Besser REJ, Bell KJ, Couper JJ, et al. Pediatr Diabetes. 2022;23(8):1175-1187.​
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