Risk Factors:

About 10 million American adults have peripheral artery disease (PAD). Although it was once believed that PAD occurs more often in men than women, current research now indicates that both genders are equally susceptible. African-Americans have twice the risk for PAD as Caucasians. Between 15 - 20% of people over age 65 suffer from the condition.

PAD Risk Factors

The most important risk factors for PAD and intermittent claudication are the same as the major risk factors for heart disease and stroke. People with a combination of these conditions (including PAD) are at increased risk of a more severe form of the heart or circulatory disease. Smoking and high cholesterol levels may increase the risk for PAD progression in large blood vessels (such as the legs), while diabetes increases the risk for PAD in small blood vessels (such as the feet). Quitting smoking and controlling cholesterol are the two best ways to slow PAD progression.

The most important risk factors for PAD include:

• Smoking. Smoking is the number one risk factor for PAD and smoking even a few cigarettes a day can interfere with PAD treatment. Smoking increases the risk for PAD by 2 - 25 times, with the danger being higher when other risk factors are present. Between 80 - 90% of patients with PAD are current or former smokers. Progression to a more critical state of illness is likely for patients who continue to smoke. [For more information, see In-Depth Report #41: Smoking.]
• Diabetes. People with type 2 diabetes have 3 - 4 times the normal risk for PAD and intermittent claudication. In fact, their risk for PAD is higher than their risk for heart disease. People with type 2 diabetes also tend to develop PAD at an earlier age and have more severe cases. Patients with both diabetes and PAD are at high risk for complications in the feet and ankles. Poor blood sugar (glucose) control increases the risk of developing PAD. [For more information, see In-Depth Report #60: Diabetes - type 2.]
• Unhealthy cholesterol and lipid levels. The risk for PAD increases by 5 - 10% with every 10 mg/dL increase in total cholesterol levels. Levels of HDL ("good cholesterol") below 40 mg/dL and high triglyceride levels also increase the risk for PAD. LDL ("bad cholesterol") levels should be kept below 100 mg/dL in all patients with PAD, and probably as low as 70 mg/dL when other risk factors are present (such as diabetes, coronary artery disease, smoking, and HDL below 40 mg/dL). [For more information, see In-Depth Report #23: Cholesterol.]
• Hypertension. High blood pressure, especially when combined with other cardiovascular risk factors, increases the chances for PAD. [For more information, see In-Depth Report #14: High blood pressure.]

Blood pressure is the force applied against the walls of the arteries as the heart pumps blood through the body. The pressure is determined by the force and amount of blood pumped and the size and flexibility of the arteries.

• Family history of heart and artery disease. Genetic factors that cause specific lipid and cholesterol abnormalities may increase the risk for PAD.
• Artery inflammation and damage. High levels of C-reactive protein can indicate persistent inflammation in the arteries. Such inflammation can cause significant damage in blood vessels, and is highly associated with PAD.
• Age. PAD occurs more frequently in people over age 50 and affects 12 - 20% of Americans age 65 years and older.
• Ethnicity. African-Americans are at highest risk for PAD. They are twice as likely to develop PAD as Caucasians.