MedWire News: HIV infection increases risk for aortic stiffness and coronary artery calcification (CAC), two subclinical markers of atherosclerosis, but CAC may be reduced by long term highly active antiretroviral therapy (HAART) therapy, show results from two studies.
"The association of increased cardiovascular risk in persons with HIV infection and exposure to antiretroviral therapy is not completely understood," comment Giuseppe Schillaci (University of Perugia, Italy) and colleagues in their study published in the journal Hypertension.
Schillaci and team investigated whether aortic stiffness, an early marker of atherosclerosis, was increased in 39 untreated HIV patients compared with 78 age-, gender-, and blood pressure-matched controls, by using aortic pulse wave velocity (PWV).
In a separate study, published in the journal AIDS, Lawrence Kingsley (University of Pittsburgh, Philadelphia, USA) and team investigated the extent of CAC using computed tomography imaging in 531 HIV-infected patients treated with HAART for varying durations, 84 HAART-naïve patients, and 332 HIV-negative controls.
Schillaci and co-authors found HIV-infected patients had higher aortic PWV than controls at 7.5 versus 6.7 m/s, respectively. After controlling for potential confounders they observed that age, mean arterial pressure, and HIV infection independently predicted aortic PWV.
Of note, they also found that more HIV infected patients had the metabolic syndrome than controls at 18% versus 5%, respectively.
Kingsley and colleagues found that after adjusting for factors such as age, race, lipid levels, and hypertension, both HIV infection and long-term HAART use increased the risk for CAC with respective odds ratios of 1.35 and 1.33. HAART therapy is also associated with elevated lipid levels in HIV infected individuals.
The researchers comment that, interestingly, for patients not taking lipid-lowering therapy, HAART usage of at least 8 years was linked with significantly reduced CAC scores compared with HIV-negative controls. However, they observed that use of lipid-lowering drugs was twice as high in patients taking long-term HAART therapy than in controls, so the relevance of this is unclear.
Schillaci et al conclude: "These findings suggest HIV infection as a potentially relevant contributor to arteriosclerosis and provide a conceptual background for the increased cardiovascular risk observed among HIV-infected individuals regardless of antiretroviral treatment."
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Hypertension 2008; 52: 308-313