Background:  During aging, HIV infection could accelerate the emergence of cognitive disorders, despite the widespread use of virologically effective combination ART (cART).

Methods:  We report here the neurocognitive subset (Neurosigma) of the Sigma study, an observational, cross-sectional study designed to describe the medical conditions and the psychosocial status of patients aged 60 years and more in the Bicetre HIV Cohort, a hospital cohort of 1350 HIV-infected patients. Demographic data, medical and therapeutic history, cardiovascular risk (CVR), plasma HIV RNA levels, and CD4 counts since HIV diagnosis were collected. Subjects with active neurologic or psychiatric diseases and low educational level were excluded. Subjects underwent a brief neuropsychological exam using the Trailmaking A/B and the Digit Symbol yielding a composite NPZ3 score (assessing psychomotor speed, attention, cognitive sequencing, and shifting cognitive sets). The Mini-Mental State Examination (MMSE), the Geriatric Depression Scale (GDS), and the Instrumental Activity of Daily Living (IADL) were performed.

Results:  Among the 66 patients older than 60 years, 37 (56%) achieved the Neurosigma substudy. At enrolment, all patients except 1 were treated with cART; 73% were men. Median age was 67 years (range 60 to 84). Median duration of HIV infection and of ART were respectively 11 (IQR 5 to 17) and 10 (IQR 3 to 14) years. Median nadir CD4 count was 113 cells/µL (IQR 80 to 239), whereas the last median CD4 count was 522 cells/µL (IQR 443 to 675). HIV RNA was <50 copies/mL in all treated patients. One or more CVR factors was present in 27 patients (diabetes 27%, hypertension 49%, dyslipidemia 43%). A neurocognitive impairment was detected in 19 patients (51%). MMSE was abnormal (<–1.65 SD) in 6 (16%) patients. Severe impairment (<–2) of NPZ3 was observed in 11 patients (30%) including 4 with abnormal IADL and mild (–2≤NPZ3<–1) in 8 (21%). GDS was abnormal (>5) in 7 patients (19%).

Conclusions:  Despite a sustained response to cART, neurocognitive disorders are more frequent in old HIV⁺ patients than in the general aging population, but are underdiagnosed by their physicians. In our patients, subcortical types of cognitive impairment remain more predominant than neocortical types. The respective role of HIV, ART, and co-morbidities is debated. Longitudinal studies are needed to assess the outcome of these disorders in aging and to determine their predictive factors.