Objective: To establish whether HIV disease is associated with abnormal levels of age-related brain atrophy, by estimating apparent “brain age” using neuroimaging and exploring whether these estimates related to HIV-status, age, cognitive performance and HIV-related clinical parameters.
Methods: A large sample of virologically-suppressed HIV-positive adults (N = 162, aged 45-82 years) and highly-comparable HIV-negative controls (N = 105) were recruited as part of the COBRA collaboration. Using T1-MRI scans, a machine-learning model of healthy brain ageing was defined in an independent cohort (N = 2001, aged 18-90 years). Neuroimaging data from HIV-positive and HIV-negative individuals were then used to estimate brain-predicted age; then brain-predicted age difference (brain-PAD = brain-predicted brain age - chronological age) scores were calculated. Neuropsychological and clinical assessments were also carried out.
Results: HIV-positive individuals had greater brain-PAD score (mean ± SD = 2.15 ± 7.79 years) compared to HIV-negative individuals (-0.87 ± 8.40 years; b = 3.48, p < 0.01). Increased brain-PAD score was associated with decreased performance in multiple cognitive domains (information processing speed, executive function, memory) and general cognitive performance across all participants. Brain-PAD score was not associated with age, duration of HIV-infection or other HIV-related measures.
Conclusions: Increased apparent brain ageing, predicted using neuroimaging, was observed in HIV-positive adults, despite effective viral suppression. Furthermore, the magnitude of increased apparent brain ageing related to cognitive deficits. However, predicted brain age difference did not correlate with chronological age or duration of HIV-infection, suggesting that HIV disease may accentuate, rather than accelerate brain ageing.