deCODE Complete

Symptoms include leg-pain and cramping when walking that subside with rest.

Although genetics contribute to the risk of PAD, smoking is the most significant risk factor.

Understanding your overall risk may start you on a path to prevention.

PAD reduces blood-flow to head, arms, and legs

In peripheral arterial disease (PAD) the arteries that carry blood to the head, organs, or arms and legs, become narrowed or blocked due to fatty deposits on their inner lining. This atherosclerotic process is similar to the one that leads to coronary heart disease (CHD) and indeed, people with PAD sometimes also suffer from CHD. Peripheral arterial disease can occur in arteries anywhere in the body outside the heart, but most commonly in those of the legs and pelvis.

Early symptoms include leg pain when walking

The narrowing of arteries compromises normal blood flow and causes symptoms which vary with the severity of the disease. The earliest symptoms of PAD include leg pains and cramping associated with physical activity that subside with rest. This characteristic symptom of PAD is called claudication.

Insufficient blood flow can cause tissue damage

Severe disease in the legs can cause continuous pain and ulcers due to insufficient blood flow resulting in tissue death (gangrene) and amputation. Over 200,000 surgical and vascular (angioplasty) procedures are performed each year in the United States to prevent the onset of severe tissue damage in PAD.

Many mistake their symptoms for something else

It is estimated that PAD affects over 10% of the adult population in the industrialized world and one in five over the age of 75. In the United States about eight million people over the age of 40 are thought to have PAD. The condition often goes undetected as the symptoms can be elusive or absent.

Risk factors include environmental factors and genetics

Various factors are considered to contribute to the risk of developing of PAD, including environmental factors, of which smoking is considered the most significant. Less is currently known about the impact of genetics although it is generally believed that many genetic variations play a role and that each has a small or modest individual effect on disease development.

Genetics impact the risk of developing PAD

Scientists at deCODE genetics have discovered an association between the diagnosis of PAD and a specific variant in the genome. The variant is located on chromosome 15 within the nicotinic acetylcholine receptor gene cluster. In smokers, this same variant also increases the risk for Nicotine Dependence and Lung Cancer.

The deCODE Complete Scan identifies validated PAD risk variants and uses them to provide a personalized interpretation of the associated genetic risk for the disease. The number of variants included in the deCODE Complete Scan for each ethnic group are listed in the table below.

	Number of Variants Measured
European ancestry	2

At present, the necessary scientific information to interpret the genetic risk for individuals of other ethnicities is not available. This information will be added as soon as it becomes available and we are assured of its quality.

Risk factors for PAD

Various factors are considered to contribute to the development of PAD, of which the following are considered most significant:

• Smoking. The single most important risk factor for peripheral arterial disease is smoking.
• Age and gender. Peripheral arterial disease is more common in men than women and the incidence increases with age.
• Other cardiovascular risk factors. In addition to cigarette smoking, diabetes and high blood pressure are significant risk factors. Abnormal cholesterol levels are also associated with the disease.
• Ethnicity. Peripheral arterial disease is more common in African-American and Hispanic individuals than those of European or Asian descent.

Not smoking and exercising are important prevention strategies

In relation to PAD the importance of a healthy lifestyle cannot be overstated. Regular exercise and not smoking are the two most important steps in both prevention and treatment. Other interventions include risk factor management, medications and surgeries.

• Risk factor management: Never to start smoking – or stopping if you do smoke – is the single most important step in prevention and treatment of PAD. This cannot be emphasized enough. Other interventions include treatment of high blood pressure, high cholesterol and diabetes. Equally important is a structured exercise program which is often the most effective treatment for symptoms of PAD.
• Medication: Most patients are prescribed a weak blood thinner such as aspirin or clopidogrel to prevent blood clot formation and in some cases the medications cilostazol and pentoxifylline may help alleviate symptoms and increase walking distance.
• Surgical interventions: Bypass surgery or less invasive percutaneous procedures such as angioplasty can be recommended when noninvasive therapies have failed to improve symptoms. The choice of procedure depends on lesion characteristics and the surgical skills available.

More information

You can learn more about PAD by talking to a doctor and visiting these websites:

• American Heart Association on Peripheral Artery Disease
• Legs for Life, a risk asessment tool for PAD
• Medline Plus – Targeted Health Information for You
• The Society for Vascular Surgery on Peripheral Artery Disease
• Vascular Disease Foundation on Peripheral Artery Disease

This content was last reviewed on February 20, 2012.