C-peptide can protect diabetics from heart attack
10 May 2010
Biologists at the University of Leeds have found that a
naturally occurring substance known as C-peptide protects blood vessels
from the damaging effects of insulin. Incorporating it with insulin
treatment could revolutionise treatment for diabetics.
Lead researcher, Dr Karen Porter from Leeds Institute of
Genetics, Health and Therapeutics (LIGHT), explains: “The hormone
insulin is given to diabetes patients to control blood sugar levels
but over time it can cause the vessels that supply blood to the
heart to become blocked. As a consequence people with diabetes are
more prone to heart attacks and even if they undergo a heart bypass
operation the new veins grafted into the heart are more likely to
become blocked, leading to further damage.
“We found that administering insulin with C-peptide — which is
released naturally in partnership with insulin in healthy people —
appears to protect blood vessels against this damage.”
The researchers found that insulin on its own causes some cells
in blood vessels to grow more than they should, which would lead to
narrowing of the passageway used by the blood to get to the heart.
Amazingly when C-peptide was given along with insulin, as happens
in normal people who release both together, the excessive growth and
movement of cells was completely stopped.
“It used to be thought that the C-peptide had no function and
therefore it was not incorporated in man-made replacement insulin,
but our work indicates this is not the case,” said Dr Porter.
“Patients with diabetes are known to have higher cardiovascular
risk and some will require coronary artery bypass grafting, using a
vein from the leg. Patients donated leg veins, left over after their
operations, for research and we found that insulin on its own caused
the cells lining these veins to go into ‘over-drive,’ with increased
growth and movement that we know contribute to blockages. We were
really surprised as to how powerful C-peptide was — it completely
took away this insulin effect”.
Around 2.5 million people in the UK have Type 2 diabetes. The
more common form of the disease, associated with obesity and a
sedentary lifestyle, results in the pancreas overworking and
eventually failing. These patients will require insulin therapy over
In those diagnosed with Type 1 diabetes insulin therapy is needed
at a much earlier stage.
Dr Porter added: “The number of people affected by diabetes each
year indicates this is a problem that is not going away. Patients
can generally learn to manage and live with their diabetes but heart
disease is a complication of diabetes that kills.
“Our work suggests that a combination of insulin and its partner
C-peptide may provide a more effective treatment than insulin alone
in controlling some of the cardiovascular complications associated
RS Mughal, JL Scragg, P Lister, P Warburton K Riches, DJ O’Regan,
SG Ball, NA Turner, KE Porter. Cellular mechanisms by which
proinsulin C-peptide prevents insulin-induced neointima formation in
human saphenous vein. Diabetologia (in press).