Just because you have a normal C-Peptide level, does that mean you don’t have type 1 diabetes even though you have positive antibodies, hypothyroidism, and a strong family history of diabetes? Is it possible for your body to produce C-Peptide, but it doesn’t work and makes the test be normal?

C-Peptide is a marker of insulin secretion in the body. For every molecule of C-Peptide secreted, a molecule of insulin is secreted. Early in diabetes (loosely referring to the first few years), you may have measurable C-Peptide levels but still have type 1 diabetes. The thought is that over time, the autoimmune process that killed off the initial insulin-producing cells will do the same for the remaining cells. Therefore, you would see a gradual fall off in the C-Peptide level over time. However, it is not bad to have C-Peptide. In those patients who have some C-Peptide still secreted, it is probably easier to control blood sugars because you can still make some insulin on your own. Type 1 diabetes is less prone to have a marked family history than type 2 diabetes. Hypothyroidism tends to be more common in patients with type 1 diabetes as both are diseases that involve overactivity of the body’s immune system and often cluster together in the same patient.

JTL