Atherosclerosis, also known as hardening of the arteries, is a disease in which the arteries become narrowed and hardened as a result of a gradual buildup of plaque within the arteries. Atherosclerosis is the most common form of arteriosclerosis, a group of diseases in which the arteries become thick and hard. Although these terms are sometimes used interchangeably, atherosclerosis refers to hardening of medium and large arteries by the buildup of fat.

Normally, blood flows through the arteries, delivering oxygen and nutrients from the heart to the rest of the body. Healthy arteries are flexible and strong. With time, however, the arteries can become stiff and narrow, restricting the blood flow to organs and tissues. Tissues and cells in the body become damaged and may die without adequate blood supply.

Although some hardening of the arteries occurs naturally with age, atherosclerosis involves the buildup of plaque, composed of cholesterol (lipoproteins), calcium and other materials. Atherosclerosis is a slow, complex disease that typically starts with the appearance of fatty streaks around the aorta.

Narrowed arteries from atherosclerosis can reduce the blood supply to vital organs, such as the heart and brain. In addition, the plaque can rupture, causing larger blood clots to form that can block blood flow or travel to another part of the body.

Atherosclerosis is a major cause of death and disability in the United States, as it is the underlying problem in serious conditions including coronary artery disease, heart attack and stroke.

In addition to raising the risk of cardiovascular disease, atherosclerosis can contribute to other diabetic complications by impeding circulation. These include skin disorders, foot problems and impaired healing of wounds such as ulcers.

Individuals with diabetes are at increased risk of developing atherosclerosis for several reasons:

• High levels of glucose (blood sugar) make the blood vessels thicker and less elastic. It is more difficult for blood to pass through these arteries.
  
  
• This excess glucose (hyperglycemia) contributes to higher levels of fats in the blood. People with diabetes tend to have more fats (lipids) in their blood, which narrow and clog the arteries.
  
  
• People with type 2 diabetes, by far the most common form of diabetes, often have additional risk factors for atherosclerosis. These include high blood pressure, obesity and dyslipidemia (unhealthy levels of blood fats).

In addition, research indicates that insulin resistance, which is a feature in prediabetes, type 2 diabetes and double diabetes, may contribute to the development of atherosclerosis. It is not clear how insulin resistance is related to this disease, but it is thought to be through direct and indirect conditions. Directly, insulin resistance may change the composition and structure of the walls of the arteries. Indirectly, insulin resistance is associated with dyslipidemia (high levels of “bad” LDL cholesterol and low levels of “good” HDL cholesterol). This condition often occurs in individuals with early coronary artery disease.

According to the U.S. Centers for Disease Control and Prevention (CDC), individuals with diabetes are two to four times more likely to have heart disease than persons without diabetes. Further, the risk of stroke is about twice as likely in diabetes patients. Cardiovascular disease is the leading cause of death in patients with diabetes.