Plasma HIV RNA level has been shown to correlate with HIV disease progression, morbidity and mortality. We examined the association between levels of plasma HIV RNA and cognitive function among patients in Nigeria.
A total of 179 HIV-1 infected participants with available plasma HIV RNA results and followed longitudinally for up to 2 years were included in this study. Blood samples from participants were used for the measurement of plasma HIV RNA and CD4+ T cell count. Utilizing demographic and practice effect adjusted T scores obtained from a 7-domain neuropsychological test battery, cognitive status was determined by the global deficit score (GDS) approach, with a GDS a 0.5 indicating cognitive impairment.
In a longitudinal multivariable linear regression analysis, adjusting for CD4 cell count, Beck's depression score, age, gender, years of education, and antiretroviral treatment status, global T scores decreased by 0.35 per log10 increase in Plasma HIV RNA (p = 0328). Adjusting for the same variables in a multivariable logistic regression, the odds of neurocognitive impairment were 30% higher per log10 increase in plasma HIV RNA (OR: 1.28 [95% CI: 1.08 to 1.51]; p = 0.0048). There were statistically significant associations for the speed of information processing, executive and verbal fluency domains in both linear and logistic regression analyses.
We found a significant association between plasma HIV RNA levels and cognitive function in both baseline (cross-sectional) and longitudinal analyses. However, the latter was significantly attenuated, and appeared to be driven largely by strong associations among antiretroviral naive individuals.