HIV infection increases the risk of atherosclerosis – hardening and thickening of the arteries from plaque – by the same amount that traditional risk factors such as diabetes or smoking do, according to a study led by researchers from the San Francisco VA Medical Center and the University of California, San Francisco.
The results are significant because of the potential implications for treatment of an increasingly long-lived – and aging – cohort of HIV infected people, according to lead author Carl Grunfeld, MD, PhD, an endocrinologist at SFVAMC and a professor of medicine at UCSF.
He explains that when doctors examine patients, they classify the patients’ risk of atherosclerosis as low, intermediate, or high. Aggressive lipid-lowering drugs are recommended for high-risk patients, whereas treatment for intermediate-risk patients is “a judgment call” on the part of the physician. “Since HIV confers the same risk as diabetes,” says Grunfeld, “we would recommend that HIV infected patients in the intermediate-risk group be treated as if they are in the high-risk group.”
Grunfeld emphasizes that the impact on atherosclerosis is separate from the known effects of HIV and HIV medications on other cardiovascular risk factors – decreasing HDL or good cholesterol and increasing bad cholesterol, as well as being associated with an increased risk of diabetes. “This study indicates that HIV accelerates atherosclerosis on its own, in addition to those effects,” he says.
The study, which appears in the online “Published Ahead-of-Print” section of the journal AIDS, looked at 433 HIV infected subjects and 5,749 uninfected controls. Using ultrasound, the researchers measured the thickness of each participant’s carotid artery, a validated measure of atherosclerosis and of heart disease risk.
After adjusting for demographics – age, gender, and race – and traditional cardiovascular risk factors – blood pressure, HDL, total cholesterol, diabetes, and smoking – the authors saw that HIV infection is associated with the same magnitude of carotid arterial thickening as that associated with diabetes and smoking.
The effect is somewhat larger in women than in men, says Grunfeld, but is statistically significant in both genders.
HIV medications do not play a major role in this increased risk, according to Grunfeld, even though some of those medications are known to worsen cholesterol and increase diabetes: “This effect is so big that no drug or class of drugs stands out as being an effective contributor.”
The study does not examine possible reasons for the increased risk. However, notes Grunfeld, it is well-known that infection and inflammatory disease are associated with increased atherosclerosis, “and HIV is an infection that is accompanied by inflammation.”
Co-authors of the study are Chris Delany, PhD, of the University of Washington; Christine Wanke, MD, of Tufts Medical Center, Boston, Mass.; Judith S. Currier, MD, of UCLA; Rebecca Scherzer, PhD, of SFVAMC and UCSF; Mary Lou Biggs, PhD, of UW; Phyllis Tien, MD, and Michael Shlipak, MD, of SFVAMC and UCSF; Stephen Sidney, MD, of Kaiser Permanente, Oakland, Calif.; Joseph F. Polak, MD, MPH, of Tufts Medical Center; Daniel O’Leary, MD, of Carney Hospital, Boston, Mass.; Peter Bacchetti, PhD, of UCSF; and Richard A. Kronmal, PhD, of UW.
The study was supported by funds from the National Institutes of Health and the National Heart, Lung, and Blood Institute, some of which were administered by the Northern California Institute for Research and Education.
NCIRE - the Veterans Health Research Institute - is the largest research institute associated with a VA medical center. Its mission is to improve the health and well-being of veterans and the general public by supporting a world-class biomedical research program conducted by the UCSF faculty at SFVAMC.
SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.