People with type 2 diabetes are far more likely than others to die from heart attacks due to reduced blood supply to the heart. Recently, a team of researchers at Joslin Diabetes Center found one reason why.
When people without diabetes develop a blockage in a heart vessel, their heart cells make VEGF (vascular endothelial growth factor), which then causes the growth of new vascular endothelium (cells that line the blood vessels). In this way, their bodies form new blood vessels that detour around the blockage and help keep the blood flowing. Insulin is the signal that gets the process going: It binds with receptors on the outer membranes of heart cells and activates a pathway that produces VEGF. This response is blunted in people with insulin resistance. The heart therefore produces less VEGF and forms fewer new blood vessels.
Sources: Diabetes in Control
Arteriosclerosis, Thrombosis, and Vascular Biology