Older individuals with HIV infection have greater memory deficits than younger individuals

I. Lin Tan, B. R. Smith, Edward Hammond, Heidi Vornbrock-Roosa, Jason Creighton, O. Selnes, Justin C. McArthur, Ned Sacktor

The prevalence of HIV-associated neurocognitive disorder (HAND) remains persistently high in the era of combination antiretroviral therapy. We aimed to characterize the pattern of neurocognitive dysfunction in older subjects with HAND in particular amnestic versus non-amnestic impairment. One hundred six subjects from the Johns Hopkins University NIMH Clinical Outcomes cohort underwent standardized neuropsychological (NP) testing between November 2006 and June 2010. We examined performance in seven cognitive domains (memory, attention, speed of processing,visuospatial, language, motor, and executive). Older subjects were defined as age >50 years at the time of NP testing.Subjects were diagnosed with HAND according to established criteria and dichotomized into amnestic cognitive impairment or non-amnestic cognitive impairment with deficit defined as z scores <−1.5 for the verbal and nonverbal memory domains.There were 32 older subjects with a mean age (SD) of 54.2 (2.8) years and 74 younger subjects, 43.7 (4.3) years. Older age was associated with a 4.8-fold higher odds of memory deficits adjusted for potential confounders (p =0.035) identified a priori. With age modeled as a continuous covariate,every 1 year increase in age was associated with a 1.11-fold higher odds of memory deficit (p =0.05). There was a higher proportion of amnestic cognitive impairment among older subjects than younger subjects with HIV infection. Neurodegenerative processes other than those directly due to HIV maybe increasingly important as individuals with chronic HIV infection and HAND survive into older age.