New research suggests that the risk of strokes may be higher for HIV-positive patients.

The HIV medication HAART is associated with rises in cholesterol levels and weight. A study led by U. California-San Diego neuroscience professor Bruce Ovbiagele revealed that, due to the increase in cholesterol, HIV patients taking this medication had a higher incidence of strokes.

Ovbiagele and other researchers analyzed medical records from 1997 to 2006 and found that over time, there was a seven-percent total decrease in the rate of hospitalizations due to strokes. However, in HIV patients, there was a 60-percent increase in stroke-caused hospitalizations.

“Stroke is not very common in HIV patients, but to see such a dramatic increase, especially when the rest of the population is actually having a decrease in their stroke rate, was a little bit striking,” Ovbiagele said.

There are two different types of strokes, hemorrhagic and ischemic. Ischemic strokes, which occur when cholesterol deposits within blood vessels obstruct blood flow to the brain, are prevalent in HIV patients taking HAART medications.

The rate of hemorrhagic strokes — caused by the weakening and subsequent rupturing of blood vessels in the brain — did not change.

“Now, the data set did not permit us to actually make a cause-and-effect analysis, so we cannot directly say, ‘These medications are definitely the cause of the rise in strokes,’” Ovbiagele said. “But it is very curious that for every other person, at least for the general population, stroke rates went down at the same time, while for HIV patients being put on these medications, they went up.”

According to Ovbiagele, some researchers argued that this could be due to the fact that HIV patients are now surviving longer in general and, as a result, are exposed to more conditions that could lead to strokes.

“That’s possible. But the fact that just one type of stroke worsened, but the other type of stroke stayed the same, tends to not support that view too much,” Ovbiagele said.

Further studies will be done on the rate of heart attacks in HIV patients to see if they can reinforce this study’s findings, which is an ongoing process.

Researchers are currently applying for more funding to start up new studies that will add to the findings from the current one.

“We want to do a similar analysis, this time just looking at heart attacks because what causes strokes and heart attacks are very similar. So if we find the same trait showing that in the general population, heart attack rates are going down, but in the HIV population, they’re going up, this will lend further support to what we’ve found [about] strokes,” Ovbiagele said.

If these findings are reinforced, HIV patients on HAART medications should take extra measures to maintain a healthy weight and cholesterol level to reduce their likelihood of a stroke.