Lg Cwd
Need Help

Submit your question to our team of health care professionals.

Current Question

See what's on the mind of the community right now.

Meet the Team

Learn more about our world-renowned team.

DTeam Archives

Review the entire archive according to the date it was posted.

April 6, 2001

Blood Tests and Insulin Injections

Question from Chicago, Illinois, USA:

I am 30 years old, was diagnosed with type 1 diabetes a year ago, and my control has been excellent with very little insulin (before breakfast: 3 units of Humalog and 8 units of NPH; dinner: 3 units of Humalog and 3 units of NPH). Recently, my non-fasting C-peptide was 3.6. How reliable is the C-Peptide test? Based on this information, how much, if any, insulin is my pancreas is producing?


C-peptide represents a portion of the precursor hormone which is cleaved away as insulin is secreted. Therefore, a molecule of C-peptide represents a molecule of insulin secreted. It is a good test to evaluate residual insulin secretion. It is best interpreted with a simultaneous glucose to determine whether there is adequate insulin secretion for a given level of blood sugar. Your level clearly indicates you have residual insulin secretion left. Based on what you have told me, I cannot determine whether you have type 1 or type 2 diabetes.

The small amount of insulin you are taking is consistent with type 1 diabetes, good insulin sensitivity, and residual insulin secretion. For patients with Late-onset Autoimmune Diabetes of Adulthood (LADA), the onset is more insidious with progressive beta cell loss. It is almost as if you are in a protracted honeymoon phase.

Keep it up. The best way to prolong the honeymoon phase is to maintain the good blood sugar control.