Does C-peptide have a physiological role?

Erythrocyte Na/K ATPase activity and diabetes: relationship with C-peptide level

“…Recent studies have suggested that C-peptide could have a biological activity [17]. C-peptide is released from the beta cells into the circulation in equimolar amount with insulin and fulfils an important function in the assembly of the two-chain insulin structure.…”

Proinsulin C peptide obviates sympathetically mediated suppression of splenic lymphocyte activity in rats

“…Although the pathogenesis of diabetic neuropathy is not known, a lack of endogenous C peptide is a possible cause [1,2]. Our results suggest that C peptide is an activator of the parasympathetic nervous system.…”

Plasma C-peptide level is inversely associated with family history of type 2 diabetes in Korean type 2 diabetic patients

“…Thus, in practice, C-peptide levels have been used as an indirect measurement of β-cell function [9][10][11]. In addition, C-peptide has been also reported as a bioactive molecule in several studies [12,13].…”