C-peptide – you’ve never heard of it? You’re not alone. C-peptide is produced when the beta cells in the pancreas manufacture insulin. For every molecule of insulin produced, the body also produces one molecule of C-peptide. People suffering from Type 1 diabetes produce less insulin and less C-peptide than other people. Why? Their beta cells are progressively destroyed, leaving the body unable to manufacture a typical level of insulin or C-peptides. In fact, testing the bloodstream for C-peptide levels is one of the ways that doctors can diagnose Type 1 diabetes.
For many years, scientists have assumed that C-peptide was merely a byproduct of the insulin-making process, with no usefulness of its own. This seemingly-insignificant molecule never seemed worthy of making the news—until now. It turns out that C-peptides may be helpful in fighting the effects of diabetes after all.
Researchers now theorize that C-peptides may enhance the ability of red blood cells to use glucose more effectively. When C-peptides bond with metal ions in the bloodstream, this seems to activate proteins on the surface of red blood cells. These activated proteins may transport glucose into the red blood cell. Why is this important? Because red blood cells do not respond to insulin, unlike other cells in the body. The increased glucose uptake apparently caused by C-peptides may be significant in improving the condition of diabetes.
What effects do C-peptides have on people with Type 1 diabetes? Studies have shown that C-peptides can improve blood flow, kidney function, and nerve function in these patients. In one trial, administering C-peptides increased the blood flow to the heart, skin, and muscles for patients with Type 1 diabetes, but had no effect on healthy patients. In other trials, administration of C-peptides improved both the speed of nerve functions and the level of sensibility impairment.
Although studies have not yet proved its efficacy conclusively, further research should shed light on whether C-peptide can help prevent or delay the onset of complications from Type 1 diabetes.
 American Chemical Society (2008, January 16). Once-irrelevant Compound May Have Medical Role In Preventing Diabetes Complications. ScienceDaily. Retrieved February 11, 2008, from http://www.sciencedaily.com/releases/2008/01/080114095556.htm