In a study published in the Jan. 21 issue of Circulation, the researchers say clogging of leg arteries, though often overlooked by primary-care doctors, can be a sign of serious coronary disease.
Diabetes and high blood pressure are key risk factors for peripheral arterial disease (PAD), a form of atherosclerosis that affects arteries leading to the legs and feet, say the researchers from the University of Colorado Health Sciences Center.
Giving blood pressure-lowering medications to those who have Type II, or adult-onset, diabetes and peripheral arterial disease substantially reduced the risk of heart attacks and strokes, the study says.
For five years, the researchers followed 950 people with adult-onset diabetes, including 53 with PAD.
Of the 53 patients with PAD, 22 in an "intensive treatment" group received the blood-pressure medications enalapril or nisoldipine, and 31 in a "moderate treatment" group received placebos. Among those who received the medications, three, or about 14 percent, had strokes or heart attacks, compared with 12, or nearly 39 percent, of those who did not take the medications.
"PAD is very common, but it's under-recognized and under-treated," says Dr. William R. Hiatt, the report's senior author and a professor of medicine at the University of Colorado Health Sciences Center. "It often presents itself as leg cramping during exercise, and physicians don't tune in to it too much."
Measuring blood pressure in the ankle can provide a crucial early warning sign of coronary disease -- and give physicians a chance to reduce the risk of heart attack or stroke through intensive blood-pressure control, the study found.
"The point of this is if you've got [PAD] in your leg, it is a sign of severe coronary disease, even in the absence of a heart attack," Hiatt says. "What we're discovering is if you treat those people aggressively, you can prevent heart attack and stroke."
Researchers also used the "ankle-brachial index," which compares the blood flow in the arm and ankle arteries of patients, to detect PAD.
Those in the moderate treatment group with PAD had an increased risk of heart attack and stroke. However, those in the intensive treatment group with PAD had no clinically relevant increased risk of either.
Hiatt says the study provides more evidence of the importance of aggressive blood-pressure control for diabetics. He adds the type of blood pressure medication -- a calcium-channel blocker or angiotensin-converting enzyme inhibitor -- did not matter.
Dr. Michael Davidson, director of preventive cardiology at Rush Heart Institute in Chicago, says the study's findings underscore the need for aggressive treatment to lower blood pressure in PAD patients.
"Before this study came out, there was kind of an impression that we should do this, but now there is more evidence that we should do this," Davidson says.
"The point is not just to treat the risk factors" for heart attack and stroke, he said, "but to treat them aggressively. Just treating them moderately may not be enough."
PAD affects 8 million to 12 million Americans, the American Heart Association says. Cholesterol-laden plaque builds up in the blood vessels and reduces blood flow to the legs. That limited blood flow can't meet the demand from legs when a person with PAD is walking or exercising, and that shortfall results in pain, aching and fatigue in the legs.