The relationship between diabetes and cardiovascular disease is clear, but the causes are complex.

Over time, too much glucose in the blood damages nerves and blood vessels. This, in turn, can cause heart disease and stroke. In addition, damage to the blood vessels in the legs can result in poor circulation and increase the risk of foot ulcers and amputations, while damage to the blood vessels that supply blood to the kidney can cause kidney failure and damage to the small blood vessels in the eye can eventually cause blindness.

High blood glucose levels don’t fully explain the relationship between diabetes and cardiovascular disease. People with diabetes also tend to have low-level inflammation of the lining of the arteries, which can interfere with the proper function of the blood vessels and make them more susceptible to developing atherosclerotic plaque – where cholesterol and other substances build up in the arteries, possibly limiting the flow of blood to the heart. 

With diabetes there is also a greater tendency for blood cells to clump together to form blood clots within the blood vessels. A blood clot that blocks the arteries supplying blood to the heart causes a heart attack, while a blood clot that blocks an artery supplying blood to the brain causes a stroke.

Diabetes & Heart Disease Risk Factors

The blood vessels in patients with diabetes are also more vulnerable to the harmful effects of other heart disease risk factors. These risk factors include:

• Smoking
• High blood pressure
• Abnormal blood lipids – High LDL (bad) cholesterol
• High triglycerides
• Low HDL (good) cholesterol
• Obesity
• Lack of physical activity
• Poorly controlled blood glucose levels
• Insulin resistance (common in Type 2 diabetes)

More than 90 percent of people with diabetes have at least one of these additional heart disease risk factors.