C-peptide

Summary

C-peptide is the central connecting segment of proinsulin, cleaved during insulin biosynthesis. Long considered biologically inert, it is now recognized to have distinct biological activity. It is under investigation primarily as a therapeutic agent for diabetic complications, particularly peripheral neuropathy, nephropathy, and microvascular dysfunction in type 1 diabetes, where C-peptide is absent or severely deficient.

Mechanism of Action

C-peptide is a 31-amino-acid peptide co-secreted equimolarly with insulin from pancreatic beta cells. It binds to G-protein-coupled receptors (potentially GPR146 and others) on cell membranes, activating signaling pathways including Na+/K+-ATPase stimulation, nitric oxide synthase activation, and MAPK/ERK pathways, leading to improved microvascular blood flow, renal function, and nerve conduction.

Routes of Administration

Goals & Uses

• Cardiac function improvement in type 1 diabetesCardioprotectionLow
• Diabetic peripheral neuropathy improvementNeuroprotection / Nerve FunctionModerate
• Microvascular blood flow improvementVascular FunctionModerate
• Endogenous insulin secretion biomarkerDiagnostic / MonitoringHigh
• Diabetic nephropathy attenuationRenal ProtectionModerate

Contraindications

• Hypersensitivity to C-peptide or formulation componentsImmunologicHigh
• Type 2 diabetes or conditions with endogenous C-peptideEndocrineModerate

Adverse Effects

• HypoglycemiaMetabolicUnknownAbnormally low blood glucose
• Injection site reactionsLocalCommon
• Antibody FormationImmunologicalUnknown
• NauseaGastrointestinalUncommonFeeling of sickness or urge to vomit

Drug Interactions

• InsulinLowMay increase risk of low blood sugar
• ACE inhibitors / ARBsLow

Population Constraints

• PregnancyReproductive SafetyRelative
• Renal impairmentOrgan ImpairmentRelative
• Pediatric patientsAgeRelative

Regulatory Status

• European UnionInvestigationalNo EMA approval for therapeutic use. Clinical trials conducted in Scandinavian countries. Used diagnostically.
• United StatesInvestigationalNo FDA approval for therapeutic use. Used as a diagnostic biomarker (laboratory test). IND studies have been conducted for diabetic neuropathy and nephropathy.
• United KingdomInvestigationalNo MHRA approval for therapeutic use. Diagnostic use established via laboratory assay.

C-peptide is not approved as a therapeutic agent by any major regulatory authority. It is used clinically as a biomarker to assess endogenous insulin secretion and beta-cell reserve. Investigational therapeutic use is limited to clinical trials. Exogenous C-peptide products are not commercially available for therapeutic use.

Evidence & Sources

No sources recorded yet.