Back to Ask the Diabetes Team Ask the Diabetes Team

From Terre Haute, Indiana, USA:

My daughter had a positive GAD test and a low C-Peptide and an A1c of 7%. She had a GTT with the following results: Fasting--90 mg/dl [5.0 mmol/L]; 30 minutes--244 mg/dl [13.6 mmol/L]; one hour--256 mg/dl [14.2 mmol/L]; and two hours--157 mg/dl [8.7 mmol/L]. Does this mean she will get type 1 diabetes?


Please see other links about the Classification and Diagnosis of Diabetes. Distinguishing type 1 from type 2 takes other matters into account. You should review our previous questions on the Diagnosis and Symptoms of diabetes.

The results on the glucose tolerance test noted, assuming that the OGTT was done correctly, does NOT fit a diagnosis of diabetes (Type 1 or otherwise). It is consistent with impaired glucose tolerance. In the presence of a CONFIRMED diagnosis of diabetes, the low C-Peptide and the positive GAD antibodies are consistent with type 1 diabetes.

An elevated A1c is NOT the way to make or confirm a diagnosis of diabetes. But, the elevated A1c, irregular glucose values, low C-peptide, and positive GAD certainly would strongly suggest a predisposition to type 1, insulin-dependent diabetes.


Original posting 12 Oct 2006
Posted to Diagnosis and Symptoms


  Back to Ask the Diabetes Team Return to the Top of This Page

Last Updated: Tuesday April 06, 2010 15:10:10
This Internet site provides information of a general nature and is designed for educational purposes only. If you have any concerns about your own health or the health of your child, you should always consult with a physician or other health care professional.

This site is published by T-1 Today, Inc. (d/b/a Children with Diabetes), a 501c3 not-for-profit organization, which is responsible for its contents. Our mission is to provide education and support to families living with type 1 diabetes.
By using this site, you agree to our Terms of Use, Legal Notice, and Privacy Policy.
© Children with Diabetes, Inc. 1995-2018. Comments and Feedback.