Sep 27, 2010
Aids medication linked to dementia
Researchers at the University of California say they have found a link between antiretroviral medication used to treat patients with HIV and brain impairments such as dementia.
Data collected from HIV negative people, HIV positive people and AIDS patients between 1990 and 1995, when antiretroviral treatment was unavailable, was compared with data from different people in the same groups collected between 2000 and 2007 when the medications were available.
The study involved around 1500 people and all were matched for age, educational level, sex, ethnicity, and neuromedical and neuropsychological evaluations.
It was found that 40% of HIV positive patients on antiretroviral treatment showed evidence of brain impairment compared with 33% of HIV positive people in the era before the medication was available.
36% of those with impairments sampled between 2000 and 2007 were just in the early stages of their infection, compared to 25% of those sampled before medication was available.
"This study underscores [the idea] that despite the benefits of modern therapies in terms of decreased mortality, there seem to be persistent neurocognitive deficits" said the University of California’s Dr. Igor Grant who led the research.
Immune system stimulation
It’s thought that the problems could be a result of chronic immune system stimulation which is induced by the treatment to achieve long-term survival.
The antiretroviral therapy means people are living longer, therefore giving the virus more time to cause problems, said Dr Grant.
Dr Victor Valcour described a “Trojan horse effect”, where white blood cells become infected with HIV, cross the blood-brain barrier and disrupt brain function.
Types of brain impairment in HIV patients
Dr Valcour estimated that as many as 50% of all HIV-infected people may have some degree of brain dysfunction, even if it is asymptomatic. Patients from the pre- and post antiretrovirals groups showed different types of impairment. In the groups of people infected and receiving treatment it was noted that there were more problems with memory, and in planning and decision making but fewer problems with certain types of verbal and motor skills.
Smoking and lifestyle of HIV positive people
There was also a warning from Dr. Valcour that other factors could be influencing the brain impairment. He said more attention needed to be paid to the fact that smoking, hypertension, diabetes and high cholesterol are common among HIV positive people.