November 20, 2012
Having HIV does not seem to be associated with neurocognitive impairment (NCI), which includes declines in memory, concentration and mental ability, according to results from a recent French cohort study. Instead, more traditional risk factors, including aging, education level, anxiety, depression, cardiovascular disease and history of head injury, were associated with NCI.
We know NCI affects many individuals living with HIV, but existing studies looking into the reasons why have been limited to groups already experiencing some form of impairment. Therefore, researchers in France designed a study to investigate a broader sample of HIV-infected patients receiving routine HIV care.
The study followed 400 HIV-infected patients with a median age of 47 years; 79% were male. About 89% were on treatment, of whom 93% had a viral load below 500 copies/mL.
To test neurocognitive function, standardized tests were given by psychologists. Information regarding traditional risk factors for NCI was also gathered from medical records. Additionally, half of the patients went through a brain MRI scan to measure white and gray matter volumes.
The prevalence of NCI was 59%, which consisted of 21% asymptomatic NCI, 31% mild neurocognitive disorders (MND) and 7% HIV-associated dementia (HAD). Risk factors associated with MND and HAD were low level of education, previous AIDS-defining events, anxiety, depression and history of brain damage. HIV and antiretroviral treatment were not related risk factors, while lower gray matter volume was associated with NCI.
"Most of the cases were related to non-HIV-related determinants," comment the authors. "The high prevalence of NCI observed in our cohort was neither associated with incomplete viral suppression nor current nor nadir CD4 count. Furthermore, we did not find any association with the current cART [combination antiretroviral therapy] regimen." [...]
After controlling for confounding factors, the investigators found that a number of traditional risk factors were associated with an increased risk of impairment.
These included lower levels of education, a history of cardiovascular disease, high cholesterol, anxiety, depression, a history of neurological disease or trauma, and diagnosis with an AIDS-defining neurological disease. No HIV-related factor such as CD4 cell count, viral load, duration of infection with the virus, or use of antiretroviral therapy had a significant association with the risk of impairment.
When the investigators restricted their analysis to the 192 participants without anxiety, depression, a history of brain damage and who also had a higher level of education, they found that only 19% had symptomatic impairment. Restricting analysis further to people without a history of cardiovascular disease reduced the prevalence to just 10%.
While more research needs to be done to further assess NCI in people living with HIV, with these results, the researchers suggested the need for better screening and treatment of cardiovascular disease, anxiety and depression.
Warren Tong is the research editor for TheBody.com and TheBodyPRO.com.
Follow Warren on Twitter: @WarrenAtTheBody.
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