C-peptide is a short peptide that is produced during the processing of proinsulin, a precursor molecule to insulin, in the pancreas. Proinsulin is cleaved by enzymes called prohormone convertases to produce insulin and C-peptide, which are released into the bloodstream in equimolar amounts.
C-peptide is not biologically active and does not have a direct effect on blood glucose levels. However, measuring C-peptide levels in the blood can be used as a marker of insulin production, as the amount of C-peptide released is proportional to the amount of insulin that is produced.
C-peptide can be used in the diagnosis and management of diabetes, as well as other conditions that affect insulin production, such as pancreatic tumors or certain genetic disorders. C-peptide levels can be measured using a variety of laboratory techniques, including immunoassays and mass spectrometry.
Publications where this method have been used:
Microbiome connections with host metabolism and habitual diet from 1,098 deeply phenotyped individuals.Asnicar F, Berry SE, Valdes AM, Nguyen LH, Piccinno G, Drew DA, Leeming E, Gibson R, Le Roy C, Khatib HA, Francis L, Mazidi M, Mompeo O, Valles-Colomer M, Tett A, Beghini F, Dubois L, Bazzani D, Thomas AM, Mirzayi C, Khleborodova A, Oh S, Hine R, Bonnett C, Capdevila J, Danzanvilliers S, Giordano F, Geistlinger L, Waldron L, Davies R, Hadjigeorgiou G, Wolf J, Ordovás JM, Gardner C, Franks PW, Chan AT, Huttenhower C, Spector TD, Segata N.Nat Med. 2021 Feb;27(2):321-332. doi: 10.1038/s41591-020-01183-8.
Human postprandial responses to food and potential for precision nutrition.Berry SE, Valdes AM, Drew DA, Asnicar F, Mazidi M, Wolf J, Capdevila J, Hadjigeorgiou G, Davies R, Al Khatib H, Bonnett C, Ganesh S, Bakker E, Hart D, Mangino M, Merino J, Linenberg I, Wyatt P, Ordovas JM, Gardner CD, Delahanty LM, Chan AT, Segata N, Franks PW, Spector TD.Nat Med. 2020 Jun;26(6):964-973. doi: 10.1038/s41591-020-0934-0.