My 11-year-old daughter weighs 63.5 pounds. Her fasting blood sugar was measured as 106 mg/dl [5.9 mmol/L]. Her beta cell function was 49.95, but it was supposed to be over 100. The doctors suggested that I put my daughter on a low glucose, low carbohydrate, low calorie diet. Furthermore, my daughter has allergies to wheat and peanuts. Since she is already so thin, is it safe to put her on such a diet?

A morning fasting (nothing to eat or drink but water for eight hours) serum glucose is not considered to be in the range of diabetes unless the value is confirmed to be more than 125 mg/dL [7.0 mmol/L] (126 mg/dl [7.0 mmol/L] or greater). A value between 100 mg/dl [5.6 mmol/L] and 126 mg/dl [7.0 mmol/L] is now considered to be consistent with “impaired fasting glucose,” which may signal that some one is on the way to diabetes. However, usually in that circumstance, the person is heavy, not thin.

I’m sorry but I really do not understand what test was assessing beta cell function and was “49.95” and not over 100.

I’d suggest that you certainly please follow up with your pediatrician, keeping in mind the following:

Is your daughter overall healthy and active? Does she have any chronic or recurring illnesses?
What medications does she take on a routine basis?
Is her appetite good?
Are her bowel habits regular and normal? Is there any recurring diarrhea?
Are there any signs of puberty yet, such as breast development?

Just to be complete, but not trying to worry you, there is a VERY RARE form of diabetes associated with SEVERE unresponsiveness to insulin. In this condition, the patient is commonly somewhat thin and has virtually no body fat (except, interestingly, around the face and genital areas), and commonly the skin gets rather uniformly dark. This may be hard to see in a person of color. The patient with this rare disorder can even look rather toned and muscular. But, the glucose values are certainly elevated into the diabetes range (much greater than or equal to 126 mg/dl [7.0 mmol/L]) and there are symptoms of diabetes such as increased urination and increased thirst.

Why don’t you write us again after you find out more?

DS