Illness and increased insulin resistance

I became aware when I received any Covid vaccinations that I had increased blood glucose levels that did not respond correctly to insulin. I am on a pump. When I actually got Covid it was worse.

I am suffering from a common cold and the same thing is happening. I have to do corrections, overriding the pump settings.

I put this in type 2 because type 2 always involves insulin resistance. Type 1 may or may not be compounded with IR.

Anyone else have this problem?


I’m surprised you haven’t seen this before. Yes, speaking as a T1, one of the classic symptoms of being sick or having an infection is an increased need for insulin, and an increased BG if insulin is not increased. The increase can be pretty dramatic (doubling or more) depending on the illness.

No way to predict needed increase, though with experience you will develop some ground rules for yourself. I tend to leave basal at standard rate, and use extra bolus insulin frequently as needed. To avoid lows when extra insulin is no longer needed, care is needed because insulin needs can return to normal levels abruptly when getting well.

Extra insulin required when sick This is not attributed to “insulin resistance” per se, but to your body going into overdrive to fight the illness, producing BG raising hormones in the process.


Surprisingly, I found that there are other factors that can drive up insulin requirements (beyond the obvious: potato chips, I mean).

  • stress
  • pain (broken leg)
  • sitting for long periods such as in a car or flying
  • acute illness (although I rarely get sick, fortunately) (and my four Covid vaccinations and more recently, flu shot, didn’t seem to have any effect on my glucose levels)

And some that seem to make me more sensitive to insulin:

  • any physical activity acts to supercharge any insulin I have on board
  • poor sleep; I’m lucky not generally to suffer from insomnia but when I do, my sugar will drop

These factors, as well as a knowledge of what foods drive my insulin requirements crazy, are much more evident to me since getting the Dexcom.

I guess it show that we’re all different, even with same diagnosis. T1DM in my case

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I have mild insulin resistance from illness but I get an extreme reaction to cortico steroids.
I also see it when I eat fats I get insulin resistance. I’ve done parallel testing of myself with toast and peanut butter toast and olive oil toast. No matter what the fat is, it gives me insulin resistance. A piece of dry toast, essentially all carb, needs half the insulin that a piece of toast with peanutbutter, something that is almost all fat.
So much so that I use about 20% less insulin when I’m eating a low fat diet even though I eat a lot more carbs on this diet
Of course I mean whole food carbs not processed things like bread. I mean I still have some bread but very little

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Yeah even topical cream spikes my BG

As others have said, it is very common to need more insulin when sick. I always test more frequently (or, if using a CGM, check it extremely frequently) when I am sick. On the other hand, when I had the COVID vaccinations, my blood sugars were quite low for 12 to 18 hours following the shots. Go figure! Fortunately, I was checking quite frequently in that situation as well and so did not encounter any real problems.

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