Peripheral Arterial Disease, or PAD, refers to plaque buildup in the blood vessels that carry blood away from your heart, especially to the legs. Plaque is composed of fat, cholesterol, and other substances.
Peripheral Artery Disease is caused by arteriosclerosis or atherosclerosis, which refers to the hardening of arteries from plaque buildup. Plaque may result from a cholesterol buildup, or it may result from injury to the blood vessel. When vessels are injured, blood clots form for healing, but may result in plaque buildup.
African Americans are twice as likely as Caucasians to have Peripheral Artery Disease.
Half of people with PAD do not have signs or symptoms. Others have intermittent claudication (pain in the legs), especially when walking up stairs, as well as ulcers and foot sores that do not heal. The severity of pain varies widely, and may occur before, during, or after activity.
Clinical Manifestations
The classic manifestation of Peripheral Artery Disease is intermittent claudication (IC). A study by Northwestern University Medical School pointed out the limitations of using IC to diagnose PAD, and identified the spectrum of leg symptoms reported. Since half of people do not have symptoms, another method was devised to test for PAD. The noninvasive ankle-brachial index (ABI) is now the standard for diagnosing the disease.
Risk Factors
The main risk factor for Peripheral Arterial Disease is smoking. In fact, smoking increases a person’s risk for PAD by four (NIH). However, quitting smoking will slow PAD progression. Diabetes is also a significant risk factor.
Additional risk factors include high cholesterol, high blood pressure, and hypoglycemia.
If blood flow is being blocked, the stagnant blood can be a potential source for infection. Pain and numbness are associated with the disease as well. The most severe result of PAD is tissue death, which could possibly lead to amputation.
In addition to the above-mentioned risks, there is a six to seven times greater risk for PAD patients to develop coronary artery disease, heart attack, and strokes than those without PAD (NIH).
A review of recent evidence was done in 2003 to name emerging risk factors for PAD. It was discovered that C-reactive protein, lipoprotein(a), fibrinogen, and homocystein are emerging risk predictors. However at the conclusion of the review, the authors suggested more research be done before those factors are included for routine screenings. They also stated the importance of modifiable risk factors, such as smoking and obesity, over the four factors they were reviewing.
Treatment
There are two goals of Peripheral Arterial Disease treatment. The first is symptoms management, like leg pain, so daily activities can be resumed. The second goal is to stop the progression of arteriosclerosis, thereby reducing risk of stroke and heart disease.
Treatment methods include stopping smoking, lowering blood pressure, lowing cholesterol, lowering glucose levels, exercise, and diet low in fat, saturated fat, trans fat, cholesterol, and sodium.
“Smoking is the dominant modifiable risk factor for PAD” (JAMA).
A study by the University of Western Australia supports the effect of lifestyle modifications—smoking cessation, exercise, and a healthy diet—in treating and preventing PAD.
Angioplasty, or surgery to open a narrow or blocked artery, may be necessary.
A clinical study in 2009 offers treatment options in the form of treadmill exercises. They found that a 6-month supervised treadmill exercise program “increases walking endurance… increases brachial arterial flow, and improved quality of life.”
Research
A 2001 study at the University of Minnesota pointed out the dangerous incidence of low physician awareness of Peripheral Arterial Disease in primary care practices, despite its prevalence. They proposed a “ABI measurement” (ankle-brachial index) to identify patients with unrecognized PAD.
Artery Disease Prevention
A meta-analysis at the University of Pennsylvania was done to establish the effect of aspirin on Peripheral Arterial Disease patients. The benefit of aspirin is well established for people with coronary or cerebrovascular disease, but until 2009 the effect on PAD patients was not known. The result of the meta-analysis was “a significant reduction in nonfatal stroke”, but inconclusive with regard to nonfatal MI and cardiovascular mortality.
The best methods of prevention against PAD include not smoking, low cholesterol, normal blood pressure, a healthy diet, and an active lifestyle.