Cardiovascular risk factors associated with lower baseline cognitive performance in HIV-positive persons

Abstract

Objective: To determine factors associated with baseline neurocognitive performance in HIV-infected participants enrolled in the Strategies for Management of Antiretroviral Therapy (SMART) neurology substudy.

Methods: Participants from Australia, North America, Brazil, and Thailand were administered a 5-test neurocognitive battery. Z scores and the neurocognitive performance outcome measure, the quantitative neurocognitive performance z score (QNPZ-5), were calculated using US norms. Neurocognitive impairment was defined as z scores <-2 in two or more cognitive domains. Associations of test scores, the QNPZ-5, and impairment with baseline factors including demographics and risk factors for HIV-associated dementia (HAD) and cardiovascular disease (CVD) were determined in multiple regression.

Results: The 292 participants had a median CD4 cell count of 536 cells/mm(3), 88% had an HIV viral load < or =400 copies/mL, and 92% were taking antiretrovirals. Demographics, HIV, and clinical factors differed between locations. The mean QNPZ-5 score was -0.72; 14% of participants had neurocognitive impairment. For most tests, scores and z scores differed significantly between locations, with and without adjustment for age, sex, education, and race. Prior CVD was associated with neurocognitive impairment. Prior CVD, hypercholesterolemia, and hypertension were associated with poorer neurocognitive performance but conventional HAD risk factors and the CNS penetration effectiveness rank of antiretroviral regimens were not.

Conclusions: In this HIV-positive population with high CD4 cell counts, neurocognitive impairment was associated with prior CVD. Lower neurocognitive performance was associated with prior CVD, hypertension, and hypercholesterolemia, but not conventional HAD risk factors. The contribution of CVD and cardiovascular risk factors to the neurocognition of HIV-positive populations warrants further investigation.

Figure z Scores and summary QNPZ-5 for 5 neuropsychological tests, by location Box plots show the distributions of baseline z scores of 292 participants; 102 participants were enrolled in Australia and North America, 45 in Brazil, and 145 in Thailand. Brackets below the location labels connect pairs of locations where mean scores are not significantly different. Boxes show the interquartile range; the horizonta line in the box denotes the median; the diamond denotes the mean. Whiskers extend 1.5 times the interquartile range above and below the z score quartiles. Circles denote outliers. Au = Australia; Br = Brazil; CT = Color Trails Test; FT = Finger Tapping Test; GPB = Grooved Pegboard Test; NA = North America; QNPZ-5 = quantitative neurocognitive performance z score; TG = Timed Gait Test; Thai = Thailand.