Can your body become immune to insulin? My 11 year old son has been a type 1 diabetic for three years. Over the past year, we have had UNCONTROLLABLE blood sugar readings so I was wondering if his body was becoming immune to the insulin. He uses one unit of NovoLog per 7 grams of carbohydrates for all meals, plus 13 units of Lantus at bedtime, and 10 units of NPH at breakfast. I hope this isn’t a silly question, but his numbers are still out of control.

It is impossible to become immune to insulin. Typically, persistently high blood sugars means that the insulin dosing is inadequate. I would suggest reviewing your son’s blood sugars with your diabetes educator and physician who can best assist you with making insulin dosing changes to better meet his needs.

MSB
Additional comments from Dr. David Schwartz:

I agree with Dr. Brown that for all practical purposes, one does not become “immune” to insulin. However, there are situations, some pretty rare (and some not at all rare), whereby the body becomes RESISTANT (not “immune”) to insulin. For example, heavy set folks with Type 2 diabetes are relatively resistant to insulin. Some metabolic conditions may make a person with Type 1 diabetes resistant to insulin.

RARE forms of severe insulin resistance can occur with the body’s immune system makes antibody proteins against insulin or the receptor onto which insulin must attach. (Technically, I would not classify this as being “immune” to insulin, but the mechanisms are related). Other rare forms of severe insulin resistance occur associated with an odd decreased distribution of normal body fat.

I agree that Dr. Brown is right on the mark that the most common explanation for poor glucose control is inadequate dosing of insulin relative to daily meal and activity planning.

DS