Determination of insulin-c peptide and its release test

Insulin-c peptide measurement and its release test are based on the determination of fasting and postprandial plasma insulin and C-peptide levels that can reflect the function of pancreatic islet B cells, and guide a clinical method of examination. Because insulin and C-peptide have a common precursor, proinsulin, one molecule of proinsulin breaks down into one molecule of insulin and one molecule of C-peptide under special effects and is released into the blood at the same time. The half-life of insulin is 4-5 minutes, while the half-life of C-peptide is about 10-13.5 minutes, and 50% of insulin is cleared by the liver, C-peptide clearance is very low, and C-peptide is not affected by external The effect of source insulin, therefore, on patients receiving insulin treatment should pay more attention to C-peptide levels to understand the function of islet B cells.