"Our finding suggests that it would be reasonable to consider HIV infection a cardiac risk factor," said principal investigator Priscilla Y. Hsue, M.D., assistant professor of medicine at the University of California, San Francisco. "Other risk factors, such as high cholesterol and high blood pressure, need to be aggressively treated in HIV patients – even if it means changes in their HIV medications to control cholesterol levels."
Researchers studied 148 HIV patients (average age 45), who had been infected 11 years and treated with protease inhibitor medications for 3.3 years. They were compared with 63 uninfected adults matched for age and gender. Protease inhibitor drugs are a common treatment for people infected with HIV.
The researchers used ultrasound to measure intima-media thickness (IMT) of the carotid arteries, which are in the neck and supply blood to the brain. IMT indicates the thickness of muscle layers in the middle of the artery wall. Carotid IMT measurement is a well-accepted, noninvasive way to assess plaque build-up in the arteries and monitor its progression.
The average carotid IMT was significantly larger in the HIV patients (0.91 millimeters) than in the controls (0.74 mm). Areas of carotid plaque were found in 45 percent of the HIV patients, compared with 24 percent of controls. When a subset of patients was retested a year later, the rate of carotid IMT growth was significantly faster among HIV patients than in the controls.
"In the HIV patients, the extent of atherosclerosis was associated with classic cardiac risk factors such as age, cholesterol levels, cigarette smoking and high blood pressure," Hsue said. "There were also indications that HIV infection itself may play a role, since patients with the lowest CD4 immune cell counts (a marker of immunodeficiency) had the thickest carotid IMT."
Co-authors are Joan C. Lo, M.D.; Arlana Franklin, R.D., M.S.; Ann F. Bolger, M.D.; Jeffrey N. Martin, M.D.; Steven G. Deeks, M.D.; and David D. Waters, M.D.
The research was partly funded by the National Institutes of Health.