September 8, 2009
Diagnosis and Symptoms
Question from Orlando, Florida, USA:
What are the tests that should be used to diagnose type 1 and what are the routine tests to check the antibodies? I am very confused about what types of tests are used to diagnose type 1 diabetes. My son has had type 1 diabetes for five years and his GAD-65 AB tests have low values, i.e., 0.17, 2.5. When we was diagnosed with type 1, his GAD-65 was 0.17. He did not have the ICA512 test done. His A1c was 10.5. His insulin total was <1.0 uu/ml (normal). How did they come to the conclusion that he was type 1? I don't see anything except his A1c and maybe he was fighting some virus. Three months prior to his diagnosis he had the MMR, DtaP and IPV vaccines (all in one day). Recently, they tested his GAD-65 and it was 2.5. However, the Islet Cell Antibody Screen was negative. His A1c was 6.7. I don't understand. Does this mean he may still have some beta cells, and that his autoimmune system has stopped destroying them?
Answer:
Diabetes is a 126 mg/dl [7.0 mmol/L] glucose fasting or over 200 mg/dl [11.1 mmol/L] with symptoms. The type of diabetes is debatable if a six-year-old has lost weight, has classic symptoms and doesn’t have lots of family members with diabetes.
Tests include GAD, insulin antibodies, IA2 antibodies and islet cell. NONE are standardized! My research colleagues don’t trust the commercial laboratories. There is a movement to create standards, just like is done for A1c, but they are not yet in place. Some experts argue you cannot trust the commercial laboratories at all. Insulin reserve can be measured by C-Peptide. I expect your son has none now.
We don’t have perfect ways to tell type today. There is a new test in the research laboratories called Z8…and no commercial laboratory has it.
By the way, the best place to get diabetes and be sure of the type is Finland….research is done on every child!
LD
