C-Peptide
Pronunciation: SEE-peptide
A peptide cleaved from proinsulin during insulin synthesis, used to assess endogenous insulin production.
Full Definition
C-peptide (connecting peptide) is a 31-amino acid peptide that is cleaved from proinsulin during insulin processing in pancreatic beta cells, resulting in equimolar secretion of insulin and C-peptide. Unlike insulin, C-peptide has a longer half-life and is not extracted by the liver, making it a more stable marker of endogenous insulin secretion. C-peptide measurement is valuable in distinguishing type 1 from type 2 diabetes, assessing beta cell function, detecting factitious hypoglycemia, and monitoring pancreatic function after transplantation.
Usage
Usage note: Capitalize 'C' and hyphenate; useful for assessing insulin independence in diabetes.
In Context
- "Undetectable C-peptide levels confirmed absolute insulin deficiency in the diabetic patient." — Diabetes classification report
- "The C-peptide suppression test ruled out endogenous insulin secretion during hypoglycemia." — Hypoglycemia workup