Agatha Walston leads a busy life. She’s a nurse in southern Indiana and a single mother of two young kids.

She’s kept control of her type 1 diabetes for over 28 years — partly through a healthy lifestyle. “I would rather snack on veggies than trash food,” the Clarksville woman says.

But when the pandemic hit, she feared that the control she maintained for so long could be unraveling. “I told my kids, I said, ‘Okay, there’s this super-killer virus on the loose, and I’m a nurse and I will probably get it.’

“That was really hard conversation to have with the kids to make sure that they knew that, you know, if mom goes, they’re still going to have each other.

People living with diabetes are not more likely to get COVID-19. But they are at a much greater risk of developing severe symptoms and complications. A COVID study in England examined more than 20,000 deaths and found that a third of those people were diabetic.

In mid-April, Walston tested positive.

She survived without hospitalization, but months later, she noticed new health issues. She was diagnosed with high cholesterol, elevated blood pressure, heart problems and glaucoma — a  condition that could cause blindness.

She recalls, “The glaucoma specialist, he had said, ‘You know, you’re already at risk for glaucoma. So we won’t know if it was COVID or diabetes.”

Walston’s doctors are unsure if COVID is behind any of these complications or if her diabetes was a contributing factor.

But many diabetics worldwide are battling health complications from a COVID infection.

“Even if your blood glucose control is perfect, you’re still going to have some risks,” says Carmella Evans-Molina, MD, PhD, director of the Diabetes Research Center at Indiana University.

COVID has the power to elevate blood sugar levels and cause insulin resistance even in previously healthy people, she says. For diabetics, this effect is magnified.

“So they might then need to make changes in their insulin regimen or changes in their diabetes medication,” Evans-Molina says. “If they’re in the hospital, obviously their providers in the hospital will be taking care of these things. But if they’re recovering from COVID at home, they need to be very careful and checking their blood glucose very frequently, and then be in communication with their doctors.”

She says that such drastic changes in blood sugar levels could cause long-term complications if not managed carefully.

Francesco Rubino, MD, a professor at King’s College London, also has been watching the emerging problem. “Since the beginning of the pandemic, we noticed there is a bidirectional relationship between COVID and diabetes.”

In a letter to the New England Journal of Medicine, he and other healthcare professionals noted that the severe insulin resistance caused by COVID might have another shocking effect. “Even people who didn’t have any history of diabetes, coming up to the hospital with clear signs of having diabetes,” he says. 

Rubino says data is still limited, so he set up a global registry called CoviDiab to track these cases.

Evans-Molina’s team has studied pancreatic cells of patients who died from COVID. They did not see evidence of the virus being able to trigger new on-set diabetes, she says, adding, “I think we’re really early in our understanding of that.”

She notes that managing COVID patients requires the use of steroids, which causes elevated blood sugar levels. This is one of many factors that could have damaging effects on diabetics — or someone with pre-diabetes.

“So we know that we’re probably seeing people who were very close to a diagnosis pass over that threshold and become diagnosed with diabetes,” she says. 

As doctors and scientists work to understand the relationship between COVID and diabetes, Walston is dealing with her medical problems. She says this year has been rough — physically and emotionally.

She adds, “The best thing about 2020 [is] not dying.”

This story was produced by Side Effects Public Media, a news collaborative covering public health. It Is republished with permission. 

This reporting is supported by the GBH Educational Foundation through the Corporation for Public Broadcasting. To learn more about the diabetes epidemic in America, watch the documentary “Blood Sugar Rising.”