title: Detection of C-Peptide in Urine as a Measure of Ongoing Beta Cell Function.
abstract: C-peptide is a protein secreted by the pancreatic beta cells in equimolar quantities with insulin, following the cleavage of proinsulin into insulin. Measurement of C-peptide is used as a surrogate marker of endogenous insulin secretory capacity. Assessing C-peptide levels can be useful in classifying the subtype of diabetes as well as assessing potential treatment choices in the management of diabetes.Standard measures of C-peptide involve blood samples collected either fasted or, most often, after a fixed stimulus (such as oral glucose, mixed meal, or IV glucagon). Despite the established clinical utility of blood C-peptide measurement, its widespread use is limited. In many instances this is due to perceived practical restrictions associated with sample collection.Urine C-peptide measurement is an attractive noninvasive alternative to blood measures of beta-cell function. Urine C-peptide creatinine ratio measured in a single post stimulated sample has been shown to be a robust, reproducible measure of endogenous C-peptide which is stable for three days at room temperature when collected in boric acid. Modern high sensitivity immunoassay technologies have facilitated measurement of C-peptide down to single picomolar concentrations.
authors.affiliation: Blood Sciences, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK. Timothy.mcdonald@nhs.ac.uk.|University of Exeter Medical School, RILD Building, Barrack Road, Exeter, EX2 5DW, UK. Timothy.mcdonald@nhs.ac.uk.
authors.forename: T J
authors.initials: TJ
authors.lastname: McDonald
authors.affiliation: Blood Sciences, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK.
authors.forename: M H
authors.initials: MH
authors.lastname: Perry
mesh_terms: D015415:Biomarkers / Q000652:urine*; D002096:C-Peptide / Q000652:urine*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D050417:Insulin-Secreting Cells / Q000502:physiology*
chemical_list: D015415:Biomarkers; D002096:C-Peptide
keywords: C-peptide; Endogenous; Insulin; UCPCR; Urine