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From Mumbai, India:

My nine-year-old son was diagnosed with type 1 diabetes about two months ago. He takes insulin shots three times a day. We have just received his blood test results and want a second opinion from the experts here. Antibody GAD - negative; Antibody Anti-Thyroid (both types) - negative; Antibody Transglutaminase - negative (no celiac disease); C-Peptide - 0.86 ng/ml (fasting) and 3.51 ng/ml (after eating) (normal range described as between 0.9 ng/ml to 4.0 ng/ml).

We have a very good doctor and he feels that since his fasting C-Peptide is below normal, my son may not have type 2, but has type 1 diabetes and we should continue with regular insulin shots for his treatment. My son's blood sugar levels are almost normal, although he experiences more hypoglycemia than hyperglycemia.

My questions are: Why is his C-Peptide almost normal? If it's because he's in his honeymoon, should we get the C-Peptide tested again in a few months? I think he is not in his honeymoon period. And, if his body is producing enough insulin, what should we do to help his body continue to do the same?


Antibody levels that are negative are not helpful. If positive, they confirm type 1 diabetes, but they are only positive about 60 to 80% of the time. This does not help one to decide how to treat. I believe such decisions should be made individually based upon a full profile of blood glucose levels: pre and postprandial checks for several days. If he is doing well clinically on insulin, then this should probably continue. C-Peptide levels are also not terribly useful unless part of a research project. Positive levels, as you describe, just indicate that his body is capable of making some insulin. Whether or not the pancreas makes the correct amount of insulin is better determined by blood glucose responses to food and insulin. We do not order C-Peptide levels very frequently since they are expensive and not easy to interpret and because they almost never help us to decide about insulin or other medications, meal planning, etc. Frequent blood glucose levels do this and are the best way to proceed. A1c levels provide back-up review of overall control coupled with downloaded blood glucose levels. If one can afford them, we would recommend at least five blood glucose levels each day and algorithms to decide how much insulin based upon activity, food/carbohydrate intake and blood glucose response/profile data.

In the future, we may be able to rely on genetic testing to help determine what exact type of diabetes one person has and which type of treatment regimen should be prescribed. But, this is still in research mode and not ready for clinical use.


Original posting 18 Sep 2007
Posted to Diagnosis and Symptoms


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Last Updated: Tuesday April 06, 2010 15:10:12
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