The rate of stroke diagnoses increased significantly between 1997 and 2006 in people living with HIV, while simultaneously falling in HIV-negative people, according to a study published online January 19 in the journal Neurology and reported by the Los Angeles Times.

Researchers have been reporting for years that cardiovascular disease (CVD) rates are on the rise in people with HIV, looking mostly at the number of heart attacks and clogged arteries in various cohorts. Less is known about the rate of stroke, which is another major form of CVD. It occurs when there is an interruption of the blood supply to any part of the brain. It can cause disability and, in many cases, death.

To explore this matter, Bruce Ovbiagele, MD—from the University of California at San Diego—and Avindra Nath, MD—from Johns Hopkins University in Baltimore—examined the medical records of HIV-positive and HIV-negative individuals from a national database of hospitalized patients who were treated for stroke between 1997 and 2006.

Ovbiagele and Nath found that while the risk of stroke in HIV-negative study participants had fallen by 7 percent over that time period, the risk had actually increased by 60 percent in people with HIV. Moreover, the researchers found that the higher stroke risk was from an increase in ischemic strokes—those caused by blood clots in the brain—rather than strokes caused by ruptured arteries (hemorrhagic stroke).

The authors concede that some of the increased risk might be tied to the fact that more people with HIV are simply living into old age, when strokes become more prevalent. They also point out, however, that the age at which HIV-positive patients experienced a stroke—the majority of whom were in their 50s—remained largely the same over the course of the study, and that this more likely points to both HIV and antiretroviral treatment as causes.

As the LA Times story concluded, “The researchers cautioned HIV physicians to be particularly alert to symptoms that might indicate that a patient is at above-normal risk for a stroke…[but that] the absolute risk of stroke was still very low, less than 0.2 percent.”