HIV-associated cognitive performance and psychomotor impairment in a Thai cohort on long-term cART.

Objectives: To assess cognitive performance and psychomotor impairment in an HIV-positive cohort, well-suppressed on combination antiretroviral therapy (cART), in an Asian resource-limited setting.

Methods: Cross-sectional sociodemographic and cognitive data were collected in 329 HIV-positive and 510 HIV-negative participants. Cognitive performance was assessed using the International HIV Dementia Scale (IHDS), Montreal Cognitive Assessment (MoCA), WAIS-III Digit Symbol, Trail Making A, and Grooved Pegboard (both hands). Psychomotor test scores in the HIV-positive participants were converted to Z-scores using scores of the HIV-negative participants as normative data. Psychomotor impairment was defined as performance on two tests more than 1 standard deviation (SD) from controls or more than 2 SD on one test. Multivariate linear and logistic regression analyses were used to investigate associations between HIV and non-HIV-related covariates and poorer cognitive performance and psychomotor impairment.

Results: HIV-positive participants, mean age 45 (SD 7.69) years received cART for a median of 12.1 years (interquartile range [IQR] 9.1-14.4). Median CD4 cell count was 563 cells/mm (IQR 435-725), and 92.77% had plasma HIV RNA <40 copies/mL. The adjusted mean differences between HIV-positive versus HIV-negative cohorts indicated significantly inferior cognitive performance (tests all <0.001) with increasing age and lower income, independently associated. Psychomotor impairment was found (<0.02) in all tests except the Grooved Pegboard non-dominant hand (=0.48). Psychomotor impairment prevalence was 43% in the HIV-positive cohort, associated with male gender and lower income.

Conclusions: In this study, in individuals with viral suppression rates >90% on long-term cART, we found that inferior cognitive performance and psychomotor impairment were primarily associated with non-HIV-related factors.