Reference Range
C-peptide is a peptide composed of 31 amino acids. It is released from the pancreatic beta cells during cleavage of insulin from proinsulin. It is mainly excreted by the kidney, and its half-life is 3-4 times longer than that of insulin.
The reference ranges for C-peptide are as follows
:
Fasting: 0.78-1.89 ng/mL or 0.26-0.62 nmol/L (SI units)
1 hour after glucose load: 5-12 ng/mL