Peripheral artery disease is a condition caused by atherosclerosis, which also causes coronary artery disease and carotid artery disease. Fatty deposits build up in artery walls and restrict blood circulation, mainly in arteries leading to the legs and feet. A common symptom is intermittent claudication - cramping or fatigue in the legs and buttocks during activity that eases during rest.
About 5 percent of people age 60 and older are believed to have claudication, says Mark A. Creager, M.D., the study's senior author and director of the Vascular Center at Brigham and Women's Hospital, Boston.
Cholesterol-lowering drugs called statins have been shown to reduce heart attacks and other cardiovascular events in patients with atherosclerosis. Creager and colleagues investigated if the statin drug atorvastatin could also reduce claudication.
Researchers examined 354 people in their 60s with claudication in a randomized, double-blind study. Participants were treated daily with either a placebo, 10 milligrams (mg) of atorvastatin or 80 mg of atorvastatin for one year. Researchers measured the total amount of time that participants could walk on a treadmill, and how long they could walk without pain. Participants were also given a quality-of-life questionnaire to gauge their total energy expenditure at work and during home and leisure-time activities for the preceding week.
"The significance of the finding is that patients with claudication treated with a statin may experience an improvement in walking distance and lifestyle in addition to the known benefits of reduced risk for heart attack, stroke and death," Creager says.
As expected, researchers found that patients taking either dose of the cholesterol-lowering drug had reductions in their total cholesterol, LDL (bad) cholesterol and triglyercides, while their HDL (good) cholesterol increased. Cholesterol levels didn't improve in patients taking placebo.
Maximal walking time didn't differ significantly between the three groups. However, the amount of time participants could walk without having leg pain improved by 63 percent for patients taking 80 mg of atorvastatin. Pain-free walking time improved by about 38 percent for patients taking placebo and those taking 10 mg of atorvastatin.
On the quality-of-life questionnaire, people taking either dose of atorvastatin showed improvement in physical activity compared to people taking placebo, Creager says.
Creager notes that only 1.3 percent of patients receiving either dose of atorvastatin experienced a worsening of claudication, foot pain or underwent a procedure to open clogged arteries. The comparable figure for the placebo patients was 7.9 percent.
Researchers say there are several possible mechanisms at work. Statins may reduce the size of the fatty plaque deposits in the artery, improve blood flow or promote the formation of new blood vessels.
Co-authors are Emile R. Mohler III, M.D., and William R. Hiatt, M.D.
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