HIV-positive people face an increased risk of heart attacks and strokes due to clogging of the major blood vessels, and two studies have found variable rates of a related condition, peripheral artery disease (PAD), in two groups of HIV-positive people.
In PAD, blood vessels carrying oxygen-rich blood to the kidneys, stomach, arms, legs or feet become restricted by arteriosclerosis—thickening and hardening of the artery walls caused by excess cholesterol. Left untreated, PAD can cause claudication—cramping, fatigue and discomfort in the legs—and potentially serious kidney damage.
In the first study, published as a letter to the editor in the Journal of Acquired Immune Deficiency Syndromes, Enrique Bernal, MD, of the Infectious Diseases Unit Hospital General Universitario de Elche Universidad Miguel Hernández in Elche, Spain, and his colleagues assessed PAD in 112 HIV-positive patients, who had two or more traditional heart disease risk factors.
To diagnose PAD, the researchers determined each patient’s ankle-brachial index—a measure of the blood pressure in the arteries supplying the legs, compared with the blood pressure in the arms. A low ankle-brachia index reading, 0.9 or less, indicates narrowing of the arteries and has been linked to an increased risk of heart disease. A high index reading, 1.4 or more, may also carry a higher risk of heart disease.
Bernal’s team found an unusually low rate of PAD in this cohort of patients. Though the rate of PAD in a general population of people with heart disease risks ranges from 5 to 30 percent, the team found a low brachia index reading in only 3.5 percent of the 112 patients, despite the fact that nearly 29 percent of the patients had four or more known heart disease risk factors.
The researchers could not explain this lower-than-expected rate of PAD, but they encourage physicians to conduct this relatively easy test in HIV-positive patients at risk for heart disease. The team did not state if any of the patients had a high ankle-brachia index reading.
In a similar study with slightly different results published in HIV Medicine, Anjali Sharma, MD, of the department of medicine at Downstate Medical Center, State University of New York in Brooklyn, and her colleagues assessed heart disease risk and looked for PAD in 335 participants in the Women’s Interagency HIV Study (WIHS).
Sharma’s team also found lower-than-expected proportions of women with a low ankle-brachia index reading. Fewer than 1 percent of the women, had an index of 0.9 or less. A high ankle-brachia index reading was found in 6.9 percent of the women, however—a rate that was higher than expected.
The team is encouraging others to conduct similar studies to determine the clinical impact, specifically of high ankle-brachia index readings. Also, these two studies stand in contrast to an abstract presented this past September at the 47th Interscience Conference on Anitimicrobial Agents and Chemotherapy in Chicago, wherein researchers found PAD in almost 21 percent of the patients studied.