While type 1 diabetes is commonly considered an autoimmune type, type 2 develops due to a complex mix of factors. Since type 1 and 2 diabetes share some symptoms, it’s natural to ask, “Is diabetes an autoimmune disease?” 

Although researchers are still trying to understand the link between diabetes and autoimmunity, current knowledge can help to illuminate everything from disease development to treatment plans.

Keep reading to find out answers to common questions, such as “Is type 1 diabetes an autoimmune disease” and “Is type 2 diabetes an autoimmune disease?”

What Is Diabetes?

Diabetes, also known as diabetes mellitus, is a condition in which the body’s ability to make insulin is compromised. The hormone insulin helps the body use the energy obtained from food (like sugars). When the body can’t utilize insulin correctly, blood sugars rise as a result since sugar just “hangs out” in the blood instead of being properly circulated or used by the cells.

There are two main types of diabetes, type 1 and type 2. In either case, blood sugar levels become elevated beyond what is normal. Chronically high blood sugar levels can contribute to high blood pressure (hypertension), which is a risk factor for a host of other diseases and disorders.

In type 1 diabetes, the body’s immune system aims to target and eliminate insulin-producing cells in the pancreas (called beta cells). As a result, dangerous levels of blood glucose (blood sugar) can cause concerning symptoms. Type 1 diabetes most commonly develops during childhood, although it can be diagnosed at any age, and is influenced by genetic factors. 

With type 2, the onset of diabetes occurs much more slowly and usually appears in adults. Insulin resistance, a condition where the body experiences an impaired insulin response, causes too much blood sugar to build up in the blood over time. Without healthy lifestyle habits or medication to help balance these changes in the body, the risk of serious symptoms and developing other serious diseases rise.

One lesser-known type of diabetes is called latent autoimmune diabetes in adults (LADA). As the name suggests, it often presents in adults around 30 years old and is commonly misdiagnosed as type 2 diabetes. In reality, it’s a form of type 1 diabetes that develops gradually instead of suddenly, earning it the nickname “type 1.5” diabetes. 

Like type 1 diabetes, in LADA, the immune system attacks pancreatic beta cells. However, this attack occurs at a much slower rate than type 1 diabetes, but onset is still relatively quick compared to type 2. 

Is Type 1 Diabetes an Autoimmune Disease?

As mentioned above, type 1 diabetes is an autoimmune diabetes. One of the main characteristics of type 1 diabetes is a chronic inflammatory response, thanks to an ongoing immune reaction against insulin-creating cells in the pancreas. 

Cells that act in the body’s own organs are called autoantibodies. Certain types of autoantibodies are elevated in the bodies of people with type 1 diabetes.

Type 1 diabetes shares many similarities with other autoimmune diseases. For example, the onset of type 1 diabetes can occur in a person’s youth after some sort of triggering event. Essentially, the genes making them susceptible to autoimmune diabetes were already there, just waiting to be activated by some sort of trigger. 

Potential triggers suggested by research include: 

• Alterations in the microbiome, or the gut environment
• Early diet like formula-fed versus breastfed, introduced to solid foods later 
• Dietary antigens, akin to gluten’s role in celiac disease
• Geographic location like cold weather
• Infection, including viral infections

Cases of LADA are especially interesting. Although technically a form of type 1 diabetes, a recent study suggested LADA may represent an overlap of both autoimmune (type 1) and “non-autoimmune” (type 2 diabetes). 

LADA often occurs after some sort of “insult” to the body, which can be connected to the triggers listed above, and may slowly affect how insulin-producing pancreas cells operate.

Another similarity in characteristics between diabetes and other autoimmune diseases is the occurrence of a “flare” or “flare up.” People with chronic autoimmune conditions can continue to have periods of time where symptoms are triggered, even after onset of the disease. 

For example, diabetic neuropathy is a symptom that can cause damage to nerves, distinguished by a tingling or burning sensation that happens from time to time. These flares often occur after one of the triggers listed above activates an inflammatory pathway, such as the weather or eating an excessive amount of a certain food. 

Is Type 2 Diabetes an Autoimmune Disease?

According to current research, type 2 diabetes is primarily a metabolic disorder. However, some studies have suggested that type 2 diabetes could, in part, also be an autoimmune disease. Patients with diabetes are known to have altered amounts of immune cells, and these cells may experience a change in function as well.

Additionally, impaired glucose metabolism is a key contributor to type 2 diabetes. While much of this is commonly attributed to poor diet or lack of exercise, scientists are asking if other autoimmune factors may play a role. Autoimmune processes in the body may affect certain cell’s ability to respond to insulin in the right way. 

For example, some studies suggest people with rheumatoid arthritis (RA) are more likely to develop type 2 diabetes. In the case of RA, the immune system mistakenly attacks healthy cells in the body, particularly in the joints. While obesity, diabetes, and RA can overlap, the inflammatory and autoimmune aspects of RA are thought to “ramp up” the risk of diabetes. 

Other research looks at possible autoimmune “triggers,” such as unhealthy lifestyle choices or advanced age. The leading theory is that diabetes seems to be linked to autoimmunity by certain environmental factors (i.e. diet, climate) and genetic factors. 

In other words, type 1 and type 2 diabetes may exist along the same autoimmune spectrum. Type 1 exists on a more extreme end, while type 2 diabetes may exhibit more mild or moderate autoimmune markers. Being prediabetic may indicate you’re progressing to a more severe point in this sliding scale. 

It’s important to note that even with a propensity towards autoimmune factors, diet, and exercise can still make a big difference in diabetes management. 

A Final Word on Diabetes and Autoimmunity

Although type 1 diabetes is known as an autoimmune condition, type 2 diabetes may have some autoimmune markers, too. In both cases, symptoms can be severe after an autoimmune cascade is triggered. While more research is needed, it is clear that factors like climate, diet, and infection can play a role in the onset and development of diabetes and autoimmunity.

References:

American Diabetes Association. Learn the Genetics of Diabetes. Diabetes.org. Accessed April 2023.

Candia P, Prattichizzo F, Garavelli S, Rosa VD, Galgani M, et al. Type 2 Diabetes: How Much of an Autoimmune Disease? Front Endocrinol (Lausanne). 2019;10:451. 

Castro MR. Latent autoimmune diabetes in adults (LADA): What is it? Mayoclinic.org. Published February 2021.

Centers for Disease Control and Prevention. Rheumatoid Arthritis (RA). Cdc.gov. Published July 2020. 

Egan AM, Dinneen SF. What is diabetes? Medicine. 2019;47(1):1-4. 

Ellis E. Understanding Diabetes. Eatright.org. Published November 2021.

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Lindladh I, Svӓrd AA, Lernmark Å. The Autoimmune Diseases. 6th ed., Academic Press, 2020. 

National Institute of Diabetes and Digestive and Kidney Diseases. Type 1 Diabetes. Niddk.nih.gov. Published July 2017. 

National Library of Medicine. Type 1 diabetes. Medlineplus.gov. Accessed April 2023. 

Petrelli A, Giovenzana A, Insalaco V, Phillips BE, Pietropaolo M, Giannoukakis N. Autoimmune Inflammation and Insulin Resistance: Hallmarks So Far and Yet So Close to Explain Diabetes Endotypes. Current Diabetes Reports. 2021;54. 

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Vieira G. What is LADA? (Latent Autoimmune Diabetes in Adults). Beyondtype1.org. Accessed April 2023.