HIV, HIV/HCV coinfection double the risk for stroke
February 26, 2010 (San Francisco, California) — Patients who are coinfected with HIV and hepatitis C virus (HCV) have a markedly increased risk for stroke — a finding that indicates that vascular risk factors need to be controlled in those with these infections, according to research presented here at the 17th Conference on Retroviruses and Opportunistic Infections.
In a large study of more than 8000 veterans, HIV-positive status was found to be associated with an increased risk for stroke, compared with those without the infection, said lead researcher and neurologist Jason Sico, MD, from the Yale University School of Medicine in New Haven, Connecticut.
"It's understood that those with HIV are more at risk for heart disease, but the risk for stroke may be underappreciated," Dr. Sico said in an interview with Medscape HIV/AIDS. "Our research shows that health risks for stroke, such as high cholesterol and metabolic syndrome, need to be addressed in those with HIV, as well as in those coinfected with HIV and HCV," he said.
In the study, researchers analyzed data on 8579 male participants in the Veterans Aging Cohort Study Virtual Cohort, and compared the incidence of stroke among those with HIV or HIV/HCV coinfection and those without these infections.
During the median follow-up of 7.3 years, the veterans experienced 160 strokes and 1181 deaths. When those with HIV or HCV/HIV were compared with uninfected individuals, the researchers found that those with HIV/HCV were at a 2-fold increased risk for stroke.
In a model in which death was used as a competing risk, those with HIV were also at a 2-fold increased risk for stroke. Because patients with HIV die sooner than those who are uninfected, adjustment for death as a confounding variable was an important part of their assessment, Dr. Sico explained. The hazard ratio dropped to 1.34 when the researchers did not adjust for mortality.
The researchers also adjusted for age, race, education, body mass index, hypertension, diabetes, smoking, hypercholesterolemia, and alcohol abuse and dependence when they characterized risk for stroke by viral status.
He noted that both HIV and HCV infection create inflammation that can increase the risk for stroke, and antiretroviral medications have adverse effects such as dyslipidemia that contribute to the enhanced risk. However, the exact biologic mechanisms for the increased risk for stroke in those with HIV and HCV need to be explored in further studies, Dr. Sico said.
"Historically, people with HIV/AIDS have not lived long enough to experience stroke. But now, in the age of antiretroviral therapy, they are surviving long enough to experience stroke," said Dr. Daniel Lackland, MD, from the Medical University of South Carolina in Charleston and a spokesperson for the American Stroke Association, in an interview with Medscape HIV/AIDS. "We do know that inflammation plays a large role in stroke, and is also part of the HIV and HCV disease process. But we need more information about the mechanisms involved," he added.
"If these findings are confirmed, a concerted effort will need to be undertaken to determine if modification of vascular risk factors adversely affected by HIV and its treatment can improve clinical outcomes," said John Booss, MD, professor emeritus in the Departments of Neurology and Laboratory Medicine at Yale University School of Medicine.
"Dr. Sico's study sheds light on the intersection of aging and chronic treated HIV infection," Dr. Booss told Medscape HIV/AIDS. "There is concern about cognitive decline in HIV infection. If one adds an increased risk of stroke, the usual complications of aging on the brain are amplified and accelerated in those with HIV infection," he added.
Dr. Sico, Dr. Booss, and Dr. Lackland have disclosed no relevant financial relationships.
By arbara Boughton
17th Conference on Retroviruses and Opportunistic Infections (CROI): Abstract 668. Presented February 18, 2010.
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