• People who’ve had COVID-19 — including those who’ve experienced only mild symptoms — appear to have a higher risk of developing diabetes, according to new research.
• Those who have none of the traditional risk factors associated with diabetes, such as obesity, also face a higher risk of developing diabetes.

While COVID-19 can be a serious life-threatening illness, the condition has also been linked to a long list of health problems that can appear well after the infection has passed. Lasting health effects may include long-term breathing problems, heart complications, chronic kidney impairment, stroke, mental health issues, and Guillain-Barré syndrome — a condition that causes temporary paralysis.

Recent research published in The Lancet Diabetes & Endocrinology has found that having even a mild case of COVID-19 can raise a person’s risk of developing diabetes within a year of infection. Data from the U.S. Department of Veterans Affairs (VA) showed that among 181,280 people who tested positive for COVID-19 in 2020 and 2021, 40 percent were more likely to be diagnosed with type 2 diabetes, compared to those who’d never had COVID-19.

The chances of developing diabetes increased in those whose illness was severe enough to require treatment in a hospital or an intensive care unit.

Study author Dr. Ziyad Al-Aly is the director of the Clinical Epidemiology Center and chief of research and education service with the VA Saint Louis Health Care System. He told myCOVIDteam, “The main eye-opening finding is that people who had COVID are at higher risk of developing diabetes, and that this is happening even in people who had no risk factors for diabetes — people who had no obesity and no other risk factors.”

Dr. Al-Aly noted, however, that people with certain risk factors exhibited higher risks and burdens. These risk factors include:

• Obesity
• Cardiovascular disease
• Hypertension
• Hyperlipidemia — Abnormally high levels of fats lipids in the blood, including cholesterol and triglycerides
• Prediabetes — Elevated blood sugar levels

A Contributor to Growing Chronic Disease

Researchers have estimated that between 1 percent and 2 percent of those who have had the virus may develop diabetes. That translates to between 800,000 and 1.6 million people in the U.S. alone.

Figures from the Centers for Disease Control and Prevention (CDC) show that more than 37 million Americans, or about 1 in 10, currently have diabetes. About 1 in 5 people with diabetes are unaware they have it. Statistics indicate that more Americans have been getting diabetes over the years. According to a 2017 CDC report, diabetes diagnoses increased from 0.93 percent of the U.S. population in 1958 to 7.4 percent in 2015. About 1.4 million new cases of diabetes were diagnosed in the U.S. in 2019.

Type 2 diabetes — the most common type of diabetes — is a condition where the body resists insulin’s effect of lowering blood sugar (glucose). Insulin — a hormone made in the pancreas — helps the body’s cells absorb blood sugar so it can be used for energy. Insulin also stimulates the liver to store blood sugar for later use.

Diabetes may lead to serious long-term health troubles, including:

• Cardiovascular disease, including heart attack, stroke, and narrowing of arteries (called atherosclerosis)
• Nerve damage (neuropathy)
• Kidney damage (nephropathy)
• Eye damage (retinopathy)
• Foot damage
• Skin conditions
• Hearing impairment
• Alzheimer’s disease
• Depression

COVID-19 and Diabetes: What’s the Connection?

Study authors aren’t sure why COVID-19 may fuel diabetes. “Some hypotheses suggest that in some people, the virus may persist in the body for months after the initial infection — and that may drive inflammation and increase diabetes risk,” said Dr. Al-Aly.

Other hypotheses, he said, focus on potential dysregulation (abnormality or impairment) of the pancreas and insulin sensitivity — that is, how well the cells in the body respond to insulin.

This research by Al-Aly and his colleagues adds to mounting evidence showing a link between COVID-19 and diabetes risk. A 2022 study out of Germany published in the journal Diabetologia found that the coronavirus may target the pancreas. Scientists have discovered that individuals who’ve had COVID-19 have impaired insulin secretion. The Diabetologia paper also said that some people develop insulin resistance (where cells don’t use insulin effectively) and have elevated blood glucose levels — despite no previous history of diabetes.

The German study also compared diabetes risk in more than 35,000 people diagnosed with COVID-19 to those with other acute upper respiratory tract infections. The researchers found that the relative risk of developing type 2 diabetes was 28 percent higher in the COVID-19 group.

The study authors stressed, however, that type 2 diabetes is unlikely to be a problem for the vast majority of people with mild COVID-19 disease.

Since COVID-19 is still relatively new, Dr. Al-Aly said that more research is needed to better determine the long-term risks from the virus.

“We are looking at what happens after the first year,” Dr. Al-Aly told myCOVIDteam. “We are also looking at the effect of vaccination, and more holistically at cardiometabolic risk — the risk of kidney disease, diabetes, and cardiovascular disease.”

As research progresses, Dr. Al-Aly advises that people should be aware that COVID-19 can lead to diabetes and that health care providers should consider COVID-19 as a risk factor for diabetes.

Find Your Team

On myCOVIDteam, the social support network for those recovering from the effects of COVID-19, you can connect with others. Members come together to ask questions, give advice, and share their stories with others who understand.

Are you living with COVID-19 or long COVID-19? Are you considering getting a second booster? Share your insights in the comments below, or start a conversation by posting on myCOVIDteam.