January 14, 2002
Question from Winnipeg, Manitoba, Canada:
I have been told that you should continue to give your regular insulin shots when you are sick (i.e. flu), even if you are not eating regularly. Does this apply even if blood glucose readings are on the low side (i.e. 3 mmol/L [54 mg/dl] )?
Sick day management does indeed change insulin requirements. The first thing to remember though is that you do still have basal insulin requirements to allow the cells continued access to glucose for energy requirements. Insulins like Lantus (insulin glargine) (which lasts over 24 hours) can make this easier, but you will need to talk to your diabetes team about the details of any change in insulin regimen.
You can temporarily omit short term insulin if blood sugars are low, but it is especially important also that you maintain some calorie intake because without it the body has to revert to fat stores for energy and this in turn leads to ketosis. You will need to cover this source of glucose with some short acting insulin like Humalog or Novolog, and you may even need to do this as often as every two hours depending on the blood sugar and urine ketone readings. However, it is important to avoid a situation in which blood sugars become too low from insufficient glucose intake, and, at the same time, ketones are present which need extra insulin. Testing urine for ketones is therefore important. It is a good idea to keep a careful record of how you managed mild intercurrent infections so that you have a guide to the next time.
[Editor’s comment: See Sick Days for further information.