icon-folder.gif   Conference Reports for NATAP  
Neurocognitive Performance Falls Faster With Age in HIV-Positive People
  6th International Workshop on HIV and Aging
October 5-6, 2015, Washington, DC
Mark Mascolini
Neurocognitive skills fell faster with age in HIV-positive than HIV-negative people from two large cohorts [1]. Among people with HIV, a lower nadir CD4 count predicted a lower global deficit score on neuropsychological tests in participants both under and over 55 years old.
Researchers working with the US CHARTER cohort noted that age-related neurodegenerative and cerebrovascular changes can affect neurocognitive performance and that these organ changes may amplify the impact of HIV on the brain as people age. To explore that possibility, they conducted this analysis of the effects of age, HIV, and an immune activation marker on neurocognitive function in two cohorts.
A cross-sectional analysis compared cognitive performance of 1520 HIV-positive people receiving comprehensive neurocognitive assessments in CHARTER and 377 demographically similar HIV-negative people enrolled in various studies in the HIV Neurobehavioral Research Program of the University of California, San Diego.
Age averaged about 38 in the groups with and without HIV, and both groups had an average 13 to 14 years of education. Proportions of men in the HIV-positive and negative groups were 81% and 71% and proportions of whites 54% and 66%. Estimated HIV duration averaged 9.8 years, nadir CD4 count 213, and current CD4 count 412, and 43% had AIDS.
Global neuropsychological performance fell significantly with age in participants with and without HIV (P < 0.001) and the decline was significantly steeper in the HIV group (P < 0.0001). Among people with HIV, nadir CD4 count below 200 was associated with worse neuropsychological performance in both younger (under 55) and older (55+) people (P < 0.001). Maintaining an undetectable viral load was associated with better neuropsychological performance, but only in younger people.
The CHARTER team looked more closely at younger and older HIV-positive people who made 3 or more study visits. This analysis included 770 people under 55 (average age 41.1) and 73 people 55 or older (average age 58.7). About 60% of both groups were men, 42% of the younger group versus 63% of the older group were white, and 40% versus 63% had AIDS. Nadir CD4 count was similar in younger and older people (180 and 175), as was current CD4 count (430 and 457).
Through up to 8 years of follow-up, neurocognitive worsening proved 40% more likely in older than younger people with HIV (P = 0.04). In the older group, 23 people had no neuropsychological decline while 42 did. The people with declining scores were more likely to have HCV infection (38% versus 17%), more likely to have a history of substance use (69% versus 48%), but less likely to have current major depressive disorder (17% versus 30%). Higher plasma MCP-1 (a marker of immune activation) was associated with worse neuropsychological performance in HIV-positive people 55 or older with a nadir CD4 count below 200 (mean neuropsychological score 7.4 versus 9.0).
1. Heaton RK, Franklin DR, Letendre SL, et al. Aging amplifies HIV neurocognitive impairment. 6th International Workshop on HIV and Aging. October 5-6, 2015, Washington, DC. Abstract 7.