I am confused about ketone formation which I understand is a sign of insulin deficiency. Last week, my six year old son had moderate to large ketones during a viral illness despite good glycemic control. We checked his blood glucose at two- hour intervals and they were 72-154 mg/dl [4-8.6 mmol/L]. The ketones cleared with extra insulin and increased fluid intake. Were the ketones a result of improper insulin dosing or a direct result of the viral infection?

Ketones show up in blood and/or urine whenever fat is burned. If someone has type 1 diabetes, they can also indicate a need for much higher doses of insulin or impending DKA [diabetic ketoacidosis].

Checking ketone values gives you added information about how much extra insulin to consider providing. If the blood glucose levels are okay and even if the ketones are moderate to high, this only means you were not providing sufficient overall calories but were providing sufficient insulin.

You should review this with your son’s diabetes team so you are more comfortable with this information since it is so important. However, if the blood glucose values are less than 200 mg/dl [11.1 mmol/L], it only means that your child had an infection, needed some extra insulin but not so much extra. Most likely, he was not eating so that fat was being burned for energy. It sounds like you did a good job.

SB