Insulin Synthesis By-products association with Type 2 DM Complications

Abstract

C-peptide has long been considered to be a biologically inert portion of proinsulin. More recently, C-peptide has been found to bind to endothelial cells, renal tubular cells and fibroblasts in a stereospecific manner and to stimulate Na+-K+-ATPase, endothelial nitric oxide synthase activities and nuclear factor-κB activation in endothelial cells exposed to hyperglycaemia. Type 2 diabetes is characterised by higher circulating concentrations of intact and split proinsulin, in absolute amounts and as proportions of total insulin secretory products. Intact proinsulin predicts progression of insulin resistance, and elevated values reveal beta-cell dysfunction. Moreover, it has been suggested that proinsulin as a molecule might be atherogenic, and intact proinsulin is considered an independent cardiovascular risk factor. The aim of our work investigate the association of insulin synthesis by-products (proinsulin and C-peptide) and the microvascular and macrovascular complications of type 2 DM.