Explained | Can COVID lead to Diabetes? Decoding the Link

5 min read
Hindi Female

Even as early as spring of 2020, when the world was just beginning to piece together the effects of the strange new virus, Diabetes was associated with COVID as a 'comorbidity' to keep watch on.

"Patients who already have diabetes or are prediabetic are more likely to be hospitalised due to COVID because their saturation level is likely to drop much faster," explains Dr Sujeet Jha, Principal Director, Endocrinology, Diabetes, Max Super Speciality Hospital, Saket.

But soon enough, experts started picking up on the fact that this connection ran both ways.

Since then, the two have been intertwined. Diabetes has often popped up in talk of COVID risks, COVID comorbidities, COVID medication and even COVID symptoms.


Over the course of the year and a half, as the different manifestations of the infection unfolded, it became more and more clear that COVID is a multi-organ infection that haunts the body long after it leaves a patient's body.

So, can COVID also cause diabetes? FIT asks experts.

The Diabetogenic Affect of COVID

Covid leads to hyperglycemia, or elevated blood sugar levels, is now known. But why does this happen?

There are multiple reasons for it, but first, let's look at how COVID affects the pancreas.

Dr Anoop Misra, Chairperson, Fortis CDOC Hospital for Diabetes and Allied Sciences, who has published multiple studies on the subject, explains this as a twofold attack.

“Covid does many things. It causes a huge system stress with cytokine storms,” he says.

Cytokine storms are a flooding of inflammatory proteins triggered by certain infections, and have been linked to many COVID complications.

Dr Misra explains, "these cytokines are also injurious to the beta cells of the pancreas, causing the insulin levels to go down and the sugar levels to go up."

He also talks about how ketoalkalosis–a phenomenon where acid accumulates in the body, that is associated with considerable beta cell destruction–has been noticed in COVID patients, indicating definite damage to the pancreas.

There is also the question of whether the virus itself directly attacks the beta cells.

In vitro lab studies in 2020 have pointed to this possibility.


Recent studies, that looked at autopsies of patients who died of COVID, however, have found SARS Cov-2 virus in the pancreatic beta cells of the deceased patients, bolstering this theory.

“The receptors for the virus are also present on the pancreatic beta cells like they are present in the lungs. So beta cells may also be attacked the way the lungs are attacked.”
Dr Anoop Misra, Chairperson, Fortis CDOC Hospital for Diabetes and Allied Sciences

But, Dr Misra, underscores that direct attack of the virus on the beta cells isn't the most likely cause–though it is one – for diabetes in COVID patients.

“I would say most cases of diabetes in COVID patients is due to steroids and cytokine storms, and in some cases, attack on the beta cells.”
Dr Anoop Misra

Diabetes in the Second Wave vs in the First Wave

“In the first wave steroids were not being used that often. We didn't know at the time that they could do much good," says Dr Misra.

“In the second wave it was being used left right and centre, in high doses, for a longer duration of time. So the use and misuse was combined together. So in the first wave, it was more of a stress cytokine and perhaps some direct damage to the pancreas. But in the second wave, its mostly because of steroid use.”
Dr Anoop Misra

Steroids, especially in high doses, are known to spike blood sugar and cause what is known as hyperglycemia.


"In these patients, who didn't have diabetes prior to COVID, once they recover and are off steroids, their blood sugars also come back to normal." says Dr Sujeet Jha, an endocrinologist with Max Hospital.

Dr Misra adds, "A number of factors determine if steroid-induced diabetes will stay. If the patients was diabetic or prediabetic to begin with, or has other complications like if their liver is enlarged, they will continue to have high sugar."

Do the new variants change things?

Dr Misra doesn't think so, considering the type of diabetes, and the way they are presented remains the same as in the first wave.

“Ketoalkalosis and instances of direct attack of the virus on the pancreas has not increased really in the second wave.”
Dr Anoop Misra

"In the second wave, more people have had moderate to severe disease and of course that demands a high dose of steroids so severe cytokine storm and high dose of steroids are more likely causing the spike in diabetes cases this time around," he adds.

But Is It Really Diabetes?

Dr Sujeet Jha has his reservations about saying, 'Covid causes diabetes', and prefers calling it 'transient hyperglycemia'.

Hyperglycemia, Dr Jha explains, is an umbrella term used for high blood glucose and can include both diabetic and non diabetics who have high blood sugar levels.

“Even if these patients remain high risk for a little while, the ‘diabetes’ is still usually transient and tends to settle once the patient has recovered and stopped using steroids.”
Dr Sujeet Jha, Principal Director, Endocrinology, Diabetes, Max Super Speciality Hospital, Delhi

Dr Anoop Misra has something similar to say.

"The kind of diabetes is occurring due to COVID-19 is partial, and recoverable," he says.

And what of the cases where the virus has caused direct damage to the pancreatic beta cells? Are those transient too?

“If there was to be complete damage of the beta cells, it causes Type 1 Diabetes. This can only be treated with insulin injections because the insulin producing beta cells are all gone. This is permanent.”
Dr Anoop Misra

"But that kind of diabetes we haven't seen actually (in COVID patients)," he adds.

Dr Misra points out that its difficult to say how many such cases there are, as there isn't sufficient data for it.

Other Factors at Play

  • Background diabetes

"We are a country where 1/3 of the people are either pre-diabetic or diabetic," says Dr Sujeet Jha. "But many of them never get tested for it."

So really, a lot of these cases of diabetes in COVID patients is just diabetes being discovered in COVID patients thanks to, what Dr Jha calls, ‘opportunistic testing’ because of hospitalisation due to COVID illness.

Because regular blood sugar testing isn't a common practice in India, many don't realise they have it till they start presenting symptoms–a point at which the blood sugar is very high.

  • Not just COVID

Dr Jha also speaks of how any viral infection can lead to elevated sugar levels.

This, once again, is likely because any severe viral infection like maleria or AIDS will trigger a cytokine storm, just like in the case of COVID.

  • Lockdown lifestyle and mental stress

It's not just in COVID patients, Diabetes has been on the rise even in non-Covid patients since the start of the pandemic, and it can be traced back to our 'new normal' lifestyle that features way too much stress and not enough movement.

“People aren’t exercising enough, people are drinking alcohol more heavily, aren’t eating enough healthy,all of this has led to a rise in diabetes in general,”
Dr Sujeet Jha

For this reason, people who don't yet have diabetes, especially those who are on the cusp or have a high risk, are advised to monitor themselves in these times.

"If you know that you have a family history of diabetes, if you are clinically obese or have a sedentary lifestyle, other issues like high cholesterol or blood pressure, it is important to you must contact your doctor to discuss necessary lifestyle changes, and how frequently you'll need to check your blood sugar," says Dr Danendra Sahu, Associate Consultant, Endocrinology, Fortis Hospital Shalimar Bagh

Moreover, the number of added health issues stacking up with COVID itself, makes it even more imperative that those at risk get vaccinated as soon as they're able to.

(At The Quint, we are answerable only to our audience. Play an active role in shaping our journalism by becoming a member. Because the truth is worth it.)

Read Latest News and Breaking News at The Quint, browse for more from fit and coronavirus

Topics:  Diabetes   COVID-19   Long COVID-19 

Speaking truth to power requires allies like you.
Become a Member
3 months
12 months
12 months
Check Member Benefits
Read More