The effect of the coronavirus on blood sugar control

minute read
February 6, 2023
A virus as seen under a microscope.
Note: Image for illustration only. Image by Daniel Roberts.

COVID-19 changed the world. Even with vaccinations and previous infections, the continuous mutations have kept everyone at risk of repeat infections. And although the virus has become weaker, it can still cause severe inflammation throughout the body.

People with diabetes are at particular risk of repeat infections of COVID.

In 2022 I caught COVID 3 times, and despite following a strict diet and medication regime it still caused my blood glucose level to vary wildly.

Multiple infections and wild blood sugar control

I received both doses of the COVID-19 vaccine but still got infected by the Omicron variant in January of 2022. The symptoms were pretty severe and lasted a long time, making my body weak for over 25 days.

As a type 2 diabetic, my blood glucose level typically varied between diabetic and pre-diabetic levels. However, COVID caused my blood glucose level to vary wildly – I ate only one proper meal during the day and had to take metformin with it to avoid spikes.

It was a rough time for my health, but after the infection passed I thought it was over for good – I believed that once you’d had COVID, you probably couldn’t get it again (or if you do, not as severely).

I discovered I was wrong when I caught it again in June 2022. By then, the COVID restrictions were pretty relaxed and I have no idea where I got it. At first, it seemed to be just a typical cold or flu. However, the cough and body ache grew until day 4, then started to subside. My blood glucose level was also affected, but not to a great extent (taking 1 tablet of metformin was enough to get it back under control) – I wasn’t really aware that COVID was affecting my blood sugar, as the change in level was so mild.

Then in November 2022, a vaccination drive at my children’s school got my 10-year-old and 7-year-old sick, even though they weren’t getting vaccinated. This brought COVID into my home again. I caught the virus while looking after my sick children and started developing symptoms of a cold and fever – I never imagined I could get COVID-19 a third time in a year!

This time, though my symptoms were mild my blood glucose levels were uncontrollable.

I’d been exercising and losing weight, so before my infection, my blood glucose level was in control and I wasn’t taking any medication. With COVID, they went wild and I had to start taking medication immediately. Even taking 1000mg of metformin twice a day, my blood sugar would still spike – This was very worrying for me, as my diet meant I was eating minimal amounts and I couldn’t exercise while unwell.

The underlying cause of deranged blood sugar with COVID

I couldn’t understand why my blood glucose level was so out of control so, as a doctor, I looked through available literature and research.

The likely explanation is the cytokine storm (a severe immune response in which the body releases lots of pro-inflammatory signalling molecules) that COVID causes, leading to severe inflammation. This increases insulin resistance and leads to higher blood glucose levels.

It’s also thought that the COVID-19 infection may damage beta cells in the pancreas, which further contributes to wild blood glucose levels.

Long term effects

My personal experience suggests that the damage COVID does to blood glucose control lasts way beyond the actual infection. At the time of writing (a month after completely recovering from my last COVID infection), my blood sugar control is still not right.

I’m following a strict low-carb diet and workout for an hour every day, but my blood glucose level keeps spiking for no reason.

I’m also trying to eat foods known to increase insulin sensitivity and improve blood sugar control (such as black coffee, cumin water, flax seeds, chia seeds, etc.), but it’s not working.

My conclusion

Having caught COVID-19 multiple times, I believe not only are type 2 diabetics more likely to catch COVID but also that the effects of the COVID-19 inflammation on the body last longer than they do for non-diabetics.

As a diabetic, this means you should try to maintain strict blood glucose control at all times – This will help keep your immune system strong and avoid a severe infection from the COVID-19 virus.

We may think the danger of COVID has reduced, but sadly it’s still very much there. So keep practising preventative measures and keep your blood glucose in control.

Graphic of a female profile picture.
Amna Bajwa

Dr. Amna Bajwa is a doctor specialising in Radiology. While not currently practising, she likes to stay in touch with her field. She’s a mother of 4, loves to cook and travel, and has recently turned into a fitness enthusiast after being diagnosed with type 2 diabetes.

Editor's note: The opinions and experiences reflected in stories from the diabetic community belong to the authors, and do not necessarily represent the views of InDiabetes.

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