Proinsulin C-peptide, released in equimolar amounts with insulin by pancreatic β cells, since its discovery in 1967 has been thought to be devoid of biological functions apart from correct insulin processing and formation of disulfide bonds between A and B chains. However, in the last two decades research has brought a substantial amount of data indicating a crucial role of C-peptide in regulating various processes in different types of cells and organs.

C-peptide acts presumably via either G-protein-coupled receptor or directly inside the cell, after being internalized. However, a receptor binding this peptide has not been identified yet. This peptide ameliorates pathological changes induced by type 1 diabetes mellitus, including glomerular hyperfiltration, vessel endothelium inflammation and neuron demyelinization.

In diabetic patients and diabetic animal models, C-peptide substitution in physiological doses improves the functional and structural properties of peripheral neurons and protects against hyperglycemia-induced apoptosis [cell death], promoting neuronal development, regeneration and cell survival. Moreover, it affects glycogen synthesis in skeletal muscles. In vitro C-peptide promotes disaggregation of insulin oligomers, thus enhancing its bioavailability and effects on metabolism.

There are controversies concerning the biological action of C-peptide, particularly with respect to its effect on Na+/K+-ATPase activity. Surprisingly, the excess of circulating peptide associated with diabetes type 2 contributes to atherosclerosis development. In view of these observations, long-term, large-scale clinical investigations using C-peptide physiological doses need to be conducted in order to determine safety and health outcomes of long-term administration of C-peptide to diabetic patients.

Health-e-Solutions comment: This brief abstract shows the importance of protecting remaining beta cells that produce insulin and c-peptide. Dr Bernstein believes we can preserve remaining beta cells by keeping blood sugars within normal ranges. That is our goal with the diabetic-alkaline lifestyle: to eat in such a way that blood sugars stay within normal ranges. If insulin injections are required to keep within normal ranges then we will give insulin. But our goal is to do all we can to protect remaining beta cells and thereby continue to produce as much endogenous insulin and c-peptide as possible. Since 2008, the date of diagnosis, we have been able to manage near-normal blood sugar control without the use of expgenous insulin.

Our Recipe e-Books provide alternatives to the typical high-carb, low nutrition foods that are standard fare for the average American diet. Our Home Study Course teaches you how to implement the diabetic-alkaline lifestyle in a practical and livable way. We think it can form the foundation for a natural, way to better manage all types of diabetes.