Q. Why am I having this test done?
If you have recently been diagnosed with type 1 or type 2 diabetes, have
a history of diabetes in your family, have reason to believe you may
have any of the symptoms associated with insulin resistance (weight
control problems are often prevalent), or are undergoing treatment with
Byetta, then you may be asked to have this test done.
Q. What will the test reveal?
The C Peptide test helps us understand how much insulin your pancreas is
producing. Specifically, it is the measurement of the amount of insulin
released by your beta cells in the islets of Langerhans in response to a
meal. The results of this test also help us evaluate if the insulin is
being used effectively.
If you exhibit a degree of insulin resistance, your
beta cells can be affected, and over time (depending on the type or
degree of insulin resistance you have), it can lead to the damage or
destruction of beta cells. This translates into little or no C-peptide
Q. What are normal values?
Your lab slip will show fasting values. This is “maximal” stimulus that
needs to be roughly at 10 to be normal.
Q. What will this cost me?
Price varies per lab and changes over time. You must check with your lab to be
Q. Why is this test important to me?
The after meal value obtained through the test is dynamic, and indicates
how near to normal your Beta cells are at that moment.
C-Peptide Information specific to patients undergoing treatment with Byetta
Q. What can I expect will happen to my C Peptide
values as I go through treatment?
A small number of patients will have an increase in their value to over
10 in 3-4 months; this represents values that have returned to normal.
The majority of patients will
have a decrease in their value of about 20% in this time. This occurs
due to the increase in ALL of the cells of the islets of
Langerhans (alpha, beta, delta, PP, and D1 cells). This change precedes
the total cell growth in the islets. This means that this process of
increased cell growth will take more time.
Q. How often do I need to have this test done?
Every 3 months until you reach normal values. After you reach normal
values, the test will be needed every 3 months for the first year.
Testing beyond that will be occasional and determined by your physician.