Beware of Fatty Deposits in Legs : Sufferers Prone to Heart Trouble, UCSD Researchers Find
A new study by researchers at the UC San Diego School of Medicine has found that people with atherosclerosis in their legs are 7 1/2 times more likely to die of cardiovascular diseases than people who don’t have such fatty deposits in their legs.
The results of the study, if confirmed by follow-up analysis, would give doctors yet another way of finding out whether their patients are in danger of suffering heart attacks and strokes.
Of particular note to patients, the test for atherosclerosis in the legs is pain-free and relatively inexpensive. It consists primarily of using ultrasound to measure the velocity of blood flow in the leg’s large arteries, and comparing pulse and blood pressure ratios in the leg, ankle and foot.
The most commonly used methods today for diagnosing atherosclerosis involve stress tests and angiography, both of which carry risks to the patient and can be painful, especially in the case of angiography, where a dye is injected into the arteries.
Dr. Michael Criqui, 41, associate professor of community and family medicine at the UCSD medical school and principal author of the study, cautions that while the study’s results are not yet definitive enough to change medical policy, “it points out that people who have the disease in their legs have a significantly increased risk of dying” of heart disease or stroke.
Criqui and his UCSD School of Medicine colleagues, Dr. Arnost Fronek and Steven Coughlin, conducted tests for atherosclerosis on the legs of 567 people from Rancho Bernardo. The tests, consisting of ultrasound and comparisons of blood pressure ratios, among others, were done from 1978 to 1981.
The researchers found that 69 people had atherosclerosis in their large arteries and 90 others had the disease in their small blood vessels.
This year, the researchers went back to find out what had happened to the people who had been tested.
What they found was that 20% of the people with diseased large arteries had died, as had 6% of those with atherosclerosis in their small blood vessels. Most of the deaths were caused by cardiovascular-related diseases.
By comparison, only 3% of the people without blocked leg arteries had died, and most of those died of other causes.
Even after the researchers adjusted their data for factors such as age, sex, cigarette smoking, cholesterol levels, blood pressure and other heart disease factors, they found that people with atherosclerosis in the large arteries of the leg had a death rate more than four times higher than people without the disease.
Criqui, in a telephone interview, said another sign of atherosclerosis in the legs, and one commonly used in the medical community, is called “claudication,” in which calf muscles ache during the beginning of exercise. This symptom is more prevalent among people 60 years of age and older.
However, Criqui noted, while people who have claudication have double the risk of heart disease, only one-tenth of the people with atherosclerosis in their large leg arteries exhibit claudication. As a result, diagnosing the disease using the methods used in the study is a more reliable predictor of a patient at risk, the study concludes.
The participants in the study ranged in age from 38 to 82, with the average age being 66. Of that group, 310 were women and 257 were men.
Criqui said people in the 60- to 65-year-old range would benefit from routine screening for atherosclerosis in the legs. “It’s easy to do and it’s inexpensive,” Criqui said. If they test positive, that would be “an alert button . . . for them to get help.”
The next step in the study, Criqui said, is to “continue to follow the population and to continue to look whether this holds up over time.” The researchers also want to find out if they can isolate specific arteries or areas of the leg that are more likely to show the presence of atherosclerosis.
The study is being reported in the October issue of Circulation, the official journal of the American Heart Assn.
