Background: HIV infected (HIV+) individuals are now reaching an advanced age, through stable treatment with highly active anti-retroviral therapy (HAART). However, HIV and aging are still risk factors for cognitive decline and neuropathologic deterioration seen in magnetic resonance imaging (MRI). Healthy lifestyle factors such as regular exercise may provide benefits to HIV+ individuals. Few studies have shown definitive benefit of aerobic exercise (AE) to HIV+ cognitive status, and none have used MRI. In this study we determine if a history of AE is beneficial to brain integrity and neurocognitive test scores in a cohort of HIV+ individuals.
Methods: A cross-sectional cohort of 70 HIV+ individuals (19-82 age range) had neuropsychological performance (NP) testing, neuroimaging, and completed an extensive self-report AE questionnaire that split the cohort into physically active (n=22) and sedentary (n=48) groups. Student’s t-tests were used to analyze demographics. Analysis of variance (ANOVA) was used to study main effects of exercise on a brief NP battery, which consisted of the following tests: Trail Making Tests A and B, Hopkins Verbal Learning Test, Digit-Symbol Coding, F-A-S and Verbal Fluency. NP tests were grouped by executive and motor function for analysis. ANOVAs were also used to study the effects of exercise upon brain volumes. This included brain volumes affected by HIV, such as the caudate and putamen, regions affected by exercise, such as the hippocampus, and general brain regions like total gray and total white matter
Results: Active and sedentary HIV+ individuals were similar for age, sex, education, and laboratory values. Physically active HIV+ patients performed significantly better than sedentary HIV+ participants on NP tests of executive (p=.04, mean Z scores of -0.654 and -0.956 respectively, [95% CI, 0.27, 0.72]) but not motor function (p=.13, mean Z scores of -0.331 and -0.827, respectively). Additionally, physically active HIV+ individuals had a significantly larger putamen (p=0.028) across the lifespan compared to the sedentary cohort.
Conclusions: Across a range of ages, AE may maintain healthy brain volumetrics in HIV+ individuals and led to improved cognitive performance. Future studies should consider exercise as an adjunctive therapy to HAART for HIV+ individuals.