C peptide of 6.1 why do I need an antibody test

I wrote a couple of days ago that my endo is suspicious that I may have LADA and ordered a C peptide test. That came back high (6.1) and she said that was unequivocal and ordered an antibody panel. I thought such a high number would certainly mean I am type 2 and not 1. Why does she still want the antibody test? Any thoughts?

Well, the interpretation of the c-peptide test really depends a lot on the glucose level of when you were tested. If you had even a slightly elevated glucose test, I would have thought a c-peptide of 6.1 (high on a typical american ng/ml scale) would indicate insulin resistance. However, that does not necessarily mean anything, and the fact that your endo is willing to order the antibody tests is great. Without knowing more about the details of your c-peptide test (i.e. was it a “stimulate” c-peptide test), it is hard to know what you endos reasoning is. Think of this like a “House” episode. In either case, more tests can only give you more information. I’ve been unable to get the antibody tests. The antibody test will pretty clearly show whether or not you have an autoimmunie reaction going on and whether you have LADA.

Good point…Yeah, I’m not at all disappointed at getting the Ab test, just trying to figure out the rationale. Just like a House episode…you’re right. By the way it was a fasting C peptide test and my glucose level was between 155 and 185 at the time.

Hi Scott: Although the c-peptide test is useful, antibody testing is definitive. If you are antibody positive, you have Type 1 autoimmune diabetes/LADA. For so many reasons, it is good to have a definitive diagnosis, as Type 1 and Type 2 are two different diseases with different treatments.