If you have diabetes, you have a higher chance of getting severe COVID-19. But you also may be at risk for experiencing lingering COVID symptoms known as long COVID. It’s important to know how diabetes can impact COVID and long COVID -- and vice versa. Doctors still don’t have all the answers because there is a limited amount of research on the topic.
What’s Long COVID?
If you have symptoms of COVID that linger for weeks and months after you had the virus, you may have long COVID (also known as post-acute sequelae of SARS-CoV-2 infection or PASC).
Long COVID is pretty common among people who had COVID, but it can be more serious in people with diabetes. Anywhere from 10% to 30% of COVID survivors have or had long COVID (other research says about 50%). Symptoms tend to improve over time in many people.
Some symptoms of long COVID are:
- Symptoms that get worse after physical or mental effort
- Lung (respiratory) symptoms, including difficulty breathing or shortness of breath and cough
More possible symptoms include:
- Neurological symptoms or mental health conditions like headache, sleep problems, difficulty thinking or concentrating, dizziness when you stand, pins-and-needles feeling, loss of smell or taste, and depression or anxiety
- Joint or muscle pain
- Heart issues such as chest pain and fast or pounding heartbeat
- Digestive symptoms like diarrhea and stomach pain
- Menstrual cycle changes
- Blood clots and blood vessel (or vascular) issues, including pulmonary embolism (a blood clot that travels to the lungs from veins in the legs and blocks blood flow to the lungs)
Treating symptoms may be harder if you have diabetes. For example, muscle fatigue from COVID or long COVID -- an existing issue for people with diabetes -- may be more difficult to treat. In turn, that can delay rehabilitation and recovery overall.
What Do We Know About COVID-19 and Long COVID in People With Diabetes?
If you have diabetes, you are more likely to have serious complications when you get COVID. Uncontrolled diabetes can lead to organ damage and microvascular (small blood vessels) injury, which can be worse if you get COVID. If your diabetes is well managed, that risk is lower.
Research suggests people may have lingering blood sugar issues long after the virus is gone. Some people -- even if they didn’t have diabetes when they went into the hospital with COVID -- experienced spikes in blood sugar, or hyperglycemia, after they left. Other complications from the virus may impact people with diabetes differently from those who do not have the disease.
Is Diabetes a Risk Factor for COVID-19 and Long COVID?
One research team looked at how common long COVID was in people with and without diabetes. Out of seven studies, three of them claimed diabetes was a risk factor for long COVID. It’s hard to get a clear conclusion because the studies differed based on what symptoms counted as long COVID, populations evaluated, and how long researchers followed up on symptoms.
People with diabetes are at a disproportionate risk for long COVID, says Jessica L. Harding, PhD, an assistant professor at Emory University School of Medicine, who led the study. In an American Diabetes Association (ADA) statement, Harding called for more studies to know for certain if diabetes is a risk factor for long COVID.
An analysis of several studies presented at the European Association for the Study of Diabetes Annual Meeting says that a high body mass index (BMI) -- not blood sugar -- is linked to higher risk for COVID and long COVID.
The ADA says there isn’t enough data to show if people with diabetes are more likely to get COVID. If you have diabetes, though, you’re more at risk to have complications from the virus than someone who doesn’t have diabetes. You’re at a higher risk for having severe complications the more health conditions you have in general, the ADA says.
Can COVID-19 Cause Diabetes?
They’re linked, but researchers haven’t established that the virus (or long COVID) can cause diabetes.
If you had COVID -- even a mild case -- your chances of getting diabetes in the year after initial infection are higher than those who didn’t have the virus, one study reports. Researchers found that the risk for diabetes went up based on how severe the virus was. Almost all the cases were type 2 diabetes.
One limit of the data is that it was on older, mostly white males. Most of them already had elevated blood pressure and were overweight -- known diabetes risk factors.
Diabetes reversed or went back to prediabetes in about half of the people diagnosed with diabetes during their hospital stay for COVID in another study. Authors of that report say people diagnosed may have already had the condition and been undiagnosed before being in the hospital.
People who recover from COVID are 28% more likely to get diabetes in the months after infection, according to another study out of Germany. Similar results have been reported in other research. But scientists haven’t established for certain that COVID actually causes diabetes.
What about type 1 diabetes? The verdict is still out. There seems to be an increase of type 1 diabetes linked to COVID compared to other respiratory infections in children. Another study found an increased risk across ages but largely in kids. That same study noted that American Indian/Alaskan Native, Asian/Pacific Islander, and Black populations are disproportionately at risk. But another study says COVID wasn’t to blame for causing diabetes in people under 35.
As more research emerges, some experts say that COVID survivors in general are at a higher risk for cardiometabolic syndrome-associated diseases such as diabetes, chronic kidney disease, and heart failure.
More studies may be able to pinpoint if COVID can cause diabetes and how it may do so. Existing studies have tried to explore the connection but don’t have definitive answers.
If we do find out that the virus can trigger short- or long-term diabetes in some people, COVID survivors should be monitored, experts warn.
How Does Long COVID Impact People With Diabetes?
There isn’t a lot of research out there to define how long COVID specifically affects people with diabetes -- or how doctors can treat it.
One study examined 128 people, some who had diabetes before getting COVID-19, others who didn’t. They took their blood at 3 and 6 months after infection.
They didn’t notice any changes in signs of inflammation. But several people had higher levels of sugar in their blood -- even some that never had diabetes before getting the virus. This may mean that blood sugar problems may persist after the acute part of the infection, but it’s unclear if those issues are defined as long COVID.
Treating COVID and long COVID with steroids can play a role in long-term metabolic and endocrine disorders, which could lead to abnormal hormone levels.
Another study looked at three issues facing people with diabetes who have had COVID-19.
- A rise in postural tachycardia syndrome (POTS), which increases your heart rate when sitting up or standing. It can be common in people with diabetes, but it was seen in other research on long COVID.
- Muscle weakness that leads to fatigue and could limit mobility.
- Possible microvascular complications affecting eyes, kidneys, and nerves.
Talk to your doctor if you have any of those symptoms (or the above-referenced symptoms of long COVID), whether you have diabetes or not.
In most people who have diabetes and experience long COVID, symptoms do improveover time. Some people are still struggling with symptoms of long COVID, and it’s unclear how they will progress as time goes on. Hopefully more research provides answers for people with diabetes and blood sugar issues who recovered from COVID.