December 30, 2005
Question from Fitzwilliam, New Hampshire, USA:
My son's physician has said my son has become insulin resistant. He says that he is unsure of the cause. My son's A1c has climbed to the 11s where it has stayed for nine months. His physician has placed him on Glucophage 1000 mg, twice daily. I've not heard of this condition. We have an appointment at the Joslin Diabetes Center in January. I would like some prior knowledge.
I understand from other parts of your letter that your son has been treated for type 1 diabetes for more than 10 years and is currently on an insulin pump. Apparently now, the degree of his response to insulin is not what it once was.
Type 1 diabetes, as you know, is a state of insulin deficiency. On the other hand, type 2 diabetes is more associated with RESISTANCE to the effect of insulin (there is also a degree of impaired insulin secretion). Insulin resistance (also called “insulin insensitivity”) has a variety of causes, some more worrisome, some not. For instance, excess weight, in and of itself, may lead to some insulin resistance. Puberty is associated with mild impaired effects of insulin as are a variety of chronic illnesses, use of some specific medications, pregnancy, and others.
On very, very rare occasions, a patient with type 1 diabetes will develop significant levels of immune protein antibodies that “attack” insulin (or its point of action) and render the insulin ineffective. There are inherited and acquired causes of SEVERE insulin resistance which, somewhat paradoxically, are associated with major DECREASES in body fat.
Nevertheless, in my experience, the most common cause of “relative” insulin resistance is actually a perceived one: it APPEARS that the patient requires more insulin, based on activities and stated meal plans, but when analyzed carefully. It often turns out that the meal plan is NOT being followed as carefully as it should be and the patient is underdosing the insulin. Sometimes, it only takes the hospitalization of the patient for a few days and NOT allowing the patient to dose insulin (leaving it TOTALLY to hospital staff and nursing) and having the staff control food intake, to see if the “resistance” goes away.
A degree of insulin resistance associated with type 1 diabetes is sometimes informally noted as “type 1-1/2 diabetes.”
Let us know what you learn. I hope this helps.