Is COVID-19 Causing Type 1 Diabetes?

Editor’s Note: We have a simple goal: tap into the power of the global diabetes community to save lives. Visit coronavirusdiabetes.org to learn more about what you can do as a person with diabetes to keep yourself and others safe from COVID-19 until we’re all safe. Visit our COVID-19 and diabetes information portal here. For a deep-dive on COVID-19 vaccines for people with diabetes click here. 

This article was written with heavy consultation from and reviewed by Sanjoy Dutta, PhD, vice president of research at JDRF, Frank Martin, PhD, director of research at JDRF, and Kimber Simmons, MD, MS, assistant professor of pediatrics at the Barbara Davis Center for Diabetes in Aurora, CO. This article was published January 31, 2022.

The CDC’s January 2022 report on the risk for newly diagnosed diabetes in children who have had COVID-19 did not adequately explain the complex science of how type 1 diabetes develops, leading to a severe misunderstanding in media coverage. Here, we’ll explain what’s really going on — as we know so far.

COVID-19 has been a disease of many unknowns, largely due to its sheer scale. While coronaviruses are not new, they are usually more contained. COVID-19 has been as novel as it is because of how quickly it expanded to a pandemic level, impacting every human life across the globe.

The virus’s severity has prompted more questions than we currently have answers for — among them, can COVID-19 cause type 1 diabetes?

To fully answer this question, we first need to understand what causes type 1 diabetes (T1D) and how the disease develops.

What causes type 1 diabetes?

Type 1 diabetes is due to a combination of genetic and environmental factors, and it develops differently depending on the age at which it is diagnosed.

To develop T1D, several things have to happen:

Genetics are the underlying key. A person who later develops T1D will test positive for several specific types of Autoantibodies are abnormal antibodies that target an individual’s own tissue. Their development is the very beginning stages of an autoimmune reaction.autoantibodies. A person without diabetes can know their risk of developing T1D by getting screened for these autoantibodies with a simple at-home blood test.

If a person tests positive for two more of the autoantibodies related to T1D, the higher the likelihood is that they will develop T1D in the coming years. But having an autoantibody does not mean a person absolutely will develop T1D.

Also important to remember — while the disease begins in your genes, you do not need to have T1D in your family in order to develop it. In fact, 90 percent of people with T1D have no family history of the disease.

For someone who already has multiple autoantibodies, something then exacerbates the disease to progress further. Once you have begun to develop autoantibodies related to T1D, there must be something that triggers the immune system to attack your insulin-producing beta cells, inducing the progressive process of T1D development. The development of the disease does not typically happen quickly.

The tough part is that researchers have not identified one simple trigger. Instead, there are several theories that have been studied:

• Environmental triggers
• A viral infection of any kind (coxsackievirus, for example)
• Gut health and/or nutrition
• Inflammation
• A stressful event (starting college, divorce, car accident, etc.)

The most important thing to remember: T1D does not simply develop overnight or over the course of a few weeks.

The full onset of the disease can occur months to years after autoantibodies start developing and possible triggers for the full development of the disease are complex, with researchers working hard to understand their scope.

“Type 1 diabetes begins to develop long before the day you’re diagnosed,” explains Sanjoy Dutta, Ph.D., and Vice President of Research at JDRF. “The things that lead to a person developing type 1 diabetes are partially in your genes. Those genes control the way your immune system behaves.”

So what is happening in the initial stages of type 1 diabetes, years before diagnosis?

In T1D, the immune system is attacking and destroying the beta cells produced by your pancreas. Beta cells are responsible for producing insulin. Without healthy beta cells, your body will struggle to produce enough insulin to keep your blood sugar levels in a healthy range. If your insulin production drops to severely low levels — and you don’t begin a daily insulin regimen — you will eventually die.

The first stage of this is the development of autoantibodies. When your immune system starts attacking your own body, your body produces specific autoantibodies depending on what’s being attacked.

We now have ways of easily detecting and measuring 4 specific types of autoantibodies related to T1D that result from this attack. The presence of 2 or more autoantibodies related to T1D indicates the early development of the disease.

Organizations like JDRF are working to make screening (at any age) for these autoantibodies a standard medical practice so that:

• people who have T1D autoantibodies are aware of their risk
• medication can be prescribed to potentially delay the final stages of the onset of T1D
• insulin production and blood sugar levels can be monitored to prevent diabetic ketoacidosis (DKA) 

The key to remember: the earliest stages of T1D begin months to years before symptoms develop. Infants, toddlers, and children who exhibit symptoms of high blood sugar and are diagnosed under the age of seven seem to have a quicker loss of beta cells than older children, teenagers, and young adults. But diagnosis under the age of two is far less common. Most children and teenagers who are diagnosed with T1D were actually in the earliest stages of the immune system attacking insulin-producing cells before the age of eight, if not earlier​, but usually don’t exhibit symptoms — signaling the final stages of progression of the disease — until ages 10 to 15​.

In adults who develop T1D after age 30, the disease’s progression is less clear, simply because there has been less research on this age group. In fact, researchers are not even completely sure that T1D diagnosed in late adulthood is actually the exact same type of diabetes as T1D diagnosed in children, teens, and young adults. But T1D can be diagnosed at any age; the diagnosis is just as common in adults as it is in children.

So can COVID-19 cause type 1 diabetes?

Short answer: there’s no way to know yet.

Developing T1D takes time. No single event is solely responsible for the development of T1D. From the time someone develops autoantibodies to the time blood sugar levels are high enough (because insulin production is low enough) that symptoms develop can be years apart, and in some cases, more than a decade.

In T1D, we know the immune system malfunctions and attacks the body’s own cells, but we still do not know why beyond the fact that this person has a genetic predisposition toward the disease.

While some US-based diabetes centers were anecdotally sharing a perceived increased rate of T1D diagnosis during the pandemic, the data does not show there has been an increase during the pandemic itself. Actually, we’ve been seeing T1D diagnosis rates increase steadily for years, particularly among Black and brown youth. We don’t yet know why.

So when we ask whether or not COVID-19 is causing T1D, the reality is that we don’t know yet, and we cannot know for some time. But we do know that COVID-19 cannot be causing entirely new cases of T1D so quickly in people who would otherwise not develop the disease.

Here’s what could actually be happening:

• A person who already has the underlying autoantibodies for T1D could then have the environmental trigger of COVID-19 cause their immune system to take that last step toward late-stage T1D.
• A person who already has the underlying autoantibodies for T1D and already had the immune system trigger to make it start developing then gets more medical attention because of COVID-19, so the T1D they already had gets caught.

In some unfortunate cases, likely because COVID-19 has been the focus, T1D symptoms may be getting missed, leading to higher rates of DKA, which can result in death if not caught early enough. That’s one of many reasons why it is so important to know the warning signs of type 1 diabetes and how the symptoms are different from COVID-19 symptoms.

Then why do people think COVID-19 may be causing type 1 diabetes?

A common phrase in the research community is “correlation does not equal causation.” This is a common error in many media headlines — taking two things that happen to exist at the same time and assuming that one is causing the other.

In this case, it is understandable that people who recently experienced a COVID-19 infection and were later diagnosed with T1D think that the COVID caused the T1D. But as we know from our understanding of autoantibodies, these people were most likely already developing T1D.

Again, the CDC’s January 2022 report on risk for newly diagnosed diabetes in children who have had COVID-19 did not adequately explain this science, leading to a severe misunderstanding in media coverage. And most media reports also do not differentiate between types of diabetes.

Here’s where more questions get raised, though. There is very early-stage research that COVID-19 may have some sort of impact on beta cells — the cells within the pancreas that produce insulin. This does not equate to an immediate T1D diagnosis, but it does raise questions that further research will need to answer in the coming years about the impact of COVID-19 on our bodies.

Two specific studies have come out looking at what happens to the beta cells in someone who has had COVID-19. However, neither study was done on people who have been diagnosed with T1D after having COVID.

One study analyzed the beta cells of people who did not have diabetes who had passed away from COVID. Another study showed that the COVID-19 virus could potentially infect insulin-producing cells, but this has only been demonstrated in stem-cell-derived beta cells, not in humans. In a petri dish environment, experts say many viruses yield these same results but these results do not cross over to humans.

Since the disease takes so long to develop, the overall conclusion from leading experts in diabetes research is that it will take at least five years, if not more, to truly determine if the COVID-19 virus is acting as an environmental factor that could increase rates of T1D.

Could COVID-19 be increasing rates of type 2 diabetes?

There’s a good chance the COVID-19 pandemic — both the disease itself and the resulting lifestyle impacts — could be increasing rates of type 2 diabetes, which is a metabolic disease caused by a complex mix of genetics, environmental impacts, socioeconomic disparities, and lifestyle.

We’ve already seen this to be true in increasing rates of childhood-onset T2D, particularly amongst children who have lost access to daily exercise and nutritious food because of school closures.

It’s also possible that people diagnosed with T2D during or after a COVID-19 infection have been living with undiagnosed T2D prior to having the virus. Going to the doctor to be tested and treated for COVID-19 could have led to basic testing of things like blood sugar, HbA1c, blood pressure, etc., leading to the sudden awareness of previously undiagnosed T2D.

What can you do?

Avoiding COVID-19 is still the goal, as the virus can lead to a large variety of long-term health issues, like long-haul COVID-19. It is best to stay as healthy as possible now.

• Get vaccinated.
• Know the symptoms of T1D and T2D.
• Screen your children (and yourself) for T1D.
• Get active! Stay active.
• Work to improve your diet, striving to eat plenty of nutrient-dense foods.
• Keep your routine healthcare visits.
• Talk to your doctor ASAP if you are concerned about your health.

Editor’s Note: The only known exception to the length of time it takes for T1D to develop is with a medication used to treat cancer. This medication can sometimes trigger the rapid development of T1D over the course of weeks.