My son was diagnosed two weeks ago. They drew insulin and C-Peptide levels, and started him on insulin injections. I am a nurse and have type 2 diabetes (as do all my eight brothers and sisters). My son is 5 feet, 5 inches, 170 pounds and is 14 years old. The pediatrician is wanting the endocrinologist to explain the insulin and C-Peptide levels, but I would just like to know if my son is really type 1 or not. We don’t have an appointment with the endocrinologist until June 26, 2006. The pediatrician told me his insulin was 4.1 and his C-Peptide 2 was 429. Maybe you could just explain to me what those numbers may mean.

I hope you are not disappointed in this answer….

The measurability of insulin and/or C-Peptide does not have the high correlation that you would want or might expect with type 1 diabetes. Perhaps more important is the level of insulin and C-Peptide measured simultaneously with the glucose level.

Probably the better test to determine type 1 versus type 2 diabetes is the presence or absence of pancreatic antibodies (most often GAD, ICA, or insulin autoantibodies).

But also, the child’s symptoms and findings at presentation would be helpful: was there weight loss? was there the presence of ketones and or acids? Did he have relatively acute onset of notable increased thirst and increased urination? These may lean more towards type 1 diabetes.

Finally, measuring a compound (such as insulin), without providing the units as to how you are measuring it, is so very not helpful. You indicated that the insulin was “4.1;” 4.1 what? The C-Peptide was “429;” 429-what?

For instance, if I asked you “How far away are you from your hospital?” and you answered “six;” what does that mean? Does that mean six blocks? Six miles? Six minutes? Six bus rides? If you can fill in the blanks about the insulin and the C-Peptide, my response can be more specific, especially if you know the glucose level (probably in “mg/dL”) measured at the same time.

DS