Most of the time a cramp in the leg is nothing to worry about. For 8 to 12 million Americans (or 1 in 20), the discomfort signals peripheral arterial disease (PAD), a narrowing of the arteries in the legs.
Despite its prevalence, PAD is not high on people's radar. According to a report in Circulation, the journal of the American Heart Association, of more than 2,500 people ages 50 and older surveyed, only 26 percent were familiar with PAD. By contrast nearly 74 percent were extremely familiar with stroke and 67 percent with coronary artery disease.
While people with PAD have a five-fold increased risk of heart attack and a two- to three-fold greater risk of stroke and death than those without the condition, just one in four people questioned equated PAD with heart attack and stroke. Only 14 percent were aware it can lead to leg amputation. Here's what you must know about this little-known but potentially serious condition:
What is PAD?
Just as fatty deposits, or plaque, can build up in your coronary arteries leading to heart disease, or in your carotid arteries causing a stroke, plaque can accumulate in the arteries of your legs. Whether the narrowing or blockages occur in your coronary, carotid (neck) or leg arteries, it's called atherosclerosis, or hardening of the arteries. And the end result is the same: An increased risk for heart attack and stroke.
While blocked leg arteries on their own are a concern, they can also be a red flag. "The blocked arteries in your legs indicate you are likely to have blocked arteries in your heart and brain, as well," explains Michael H. Criqui, M.D., M.P.H., professor and chief of the Department of Family and Preventive Medicine at the University of California, San Diego. Half of people with blocked leg arteries have significant heart disease, he adds. And up to one third have serious carotid artery disease.
What are the symptoms of PAD?
As leg arteries narrow, blood flow is reduced or blocked. The hallmark symptoms are leg cramps, tiredness or pain that flares up when you walk but eases when you rest, a phenomenon called intermittent claudication. "This occurs because the narrowed arteries can't generate enough blood flow to muscles when you walk," explains Evan Lipsitz, M.D., a vascular surgeon at Montefiore Medical Center and the Albert Einstein College of Medicine, in the Bronx, New York.
But when you stop walking, your leg muscles' demand for oxygen eases. While the cramping most often affects the calf, it can occur in the thighs or buttocks. In severe cases, it may affect the feet or toeseven at rest. Other symptoms: A wound that doesn't heal for eight to 12 weeks. PAD can make it difficult for you to fight infection; as a result, the blockage may cause ulcers and even gangrene. According to the National Institutes of Health (NIH), PAD is the main cause of leg amputation in the United States.
Who's at risk for PAD?
The older you are, the greater your risk. People 50 and over are most vulnerable, according to the Peripheral Arterial Disease Coalition. So are those who smoke or have type 2 diabetes, high blood pressure or high cholesterol. In fact, smokers have up to a four times greater risk of developing PAD than nonsmokers. If you have had a heart attack or a stroke or are African American, your risk is also higher.
How is PAD Diagnosed?
The main diagnostic tool is the ankle-branchial index (ABI), which compares the ratio of blood pressure in your ankle to the rate of blood pressure in your arm, explains Dr. Criqui. The ABI index is measured using a blood pressure cuff and ultrasound. A lower pressure at the ankle signals PAD and the lower the number, the more serious the condition. Typically ankle pressure is about 90 to 130 percent of the blood pressure in your arm; if leg arteries are extremely narrow, it may be less than 50 percent.
What can be done about PAD?
The same strategies that are good for the arteries of your heart will keep your leg arteries healthy, slowing down the build-up of plaque. Maintain a healthy weight; eat a low-fat diet; keep your blood pressure and cholesterol at healthy levels; exercise regularly; and don’t smoke. Avoid developing diabetes. And if you are diagnosed with it, be vigilant about controlling your glucose levels.
How is PAD treated?
Regular exercise is the best treatment. A prescribed regimen of walking and leg exercise can ease symptoms and help you increase the distance you can walk. "People can literally double the distance they can walk without pain," says Dr. Criqui. Typically the exercise program is supervised. If exercise isn't enough, two FDA-approved medicinespentoxifylline and cilostazolcan ease leg pain. According to the American Heart Association, aspirin, high-blood-pressure-lowering medications and cholesterol-lowering medications may also be recommended to those with PAD.
In serious cases, balloon angioplasty may be performed. Most people equate the procedure with coronary or carotid arteries but it can also be used to open leg arteries.
During the procedure, a thin tube with a balloon is inserted into the artery to widen it, and then a stent, or wire-like cage, is inserted to prop the artery open. Because arteries can re-narrow, doctors sometimes use a drug-coated stent to reduce the likelihood of this happening. Researchers recently launched a study to determine whether drug-coated stents can also help keep leg arteries open. "It's the first trial to evaluate these stents outside the heart," says Dr. Lipsitz who is the lead investigator.