[BlueSky]

Originally Posted by gambi

... I recenetly swtiched doctors and she did GAD test and it came back negatve. I know from my prior doctor that my C-peptide was a 1.2 ( don't know what the numbers mean) .... What am I???? ...

Your c-peptide is at the lower end of the normal range (0.5 - 3.0ng/ml). During the early stages of T2, one would expect to see a very high c-peptide. And the fact that you don't test positive for the GAD antibodies does not preclude T1 diabetes. So you could be a T1 who is still producing a fair amount of endogenous insulin. At the end of the day, it really doesn't matter what the type is. If the insulin treatment is working well for you, keep using it. Here is an article about c-peptide readings ...

Interpreting Your C-peptide Values
Thomas Connors, 1 September 2000

Normal C-peptide levels for a fasting test are generally considered to be anything between 0.5 nanograms (ng) per millileter (ml) and 3 ng/ml, although people who do not have diabetes may occasionally stray out of this range. The following is a range of C-peptide values in people without diabetes, as compiled by Endocrine Sciences, Inc., a California-based laboratory that conducts the test. It should be noted that, in some cases, subjects fell below the normal range of C-peptide values, but were still not found to have diabetes. The range of values may also vary according to what lab your health care practitioner uses.

Children (< 15 years old) 8:00 a.m. fasting: 0.4 to 2.2 ng/ml

Adults 8:00 a.m. fasting: 0.4 to 2.1 ng/ml

Two hours postprandial (after a meal): 1.2 to 3.4 ng/ml

Two hours post glucose load: 2.0 to 4.5 ng/ml

Although anything less than these numbers is generally an indicator of type 1 diabetes, values within the normal range can mean different things.

"Type 2s with insulin resistance could actually be making more insulin than a non-diabetic slim person," says Richard Bernstein, MD, FACE, FACN, CWS, of the Diabetes Center in Mamaroneck, New York. Values on the lower end may also indicate a honeymoon phase of type 1, when insulin production is slowing down but has not yet ground to a halt.

Bernstein also points out that even in type 1s, a positive C-peptide test should be a source of optimism.

"Of all my patients, I only have two who don't make any C-peptide, and I'm one of them," Bernstein says. He says this proves that most type 1s still produce at least some insulin and raises the possibility that therapies like beta-cell regeneration may eventually restore normal BG levels.

Interpreting Your C-peptide Values - Diabetes Health