Cardiovascular Disease, Brain Glucose Metabolism, and Neurocognitive Decline in People With Human Immunodeficiency Virus

Abstract

Background Cardiovascular disease (CVD) and neuroinflammation are thought to exacerbate neurocognitive dysfunction in treated people with HIV (PWH). Here, we longitudinally measured brain glucose metabolism as a measure of neuronal integrity in treated PWH using [18F]Fluorodeoxyglucose (FDG) PET/CT in correlation with atherosclerotic cardiovascular disease (ASCVD) scores, CSF neuroinflammatory markers, neurocognitive outcomes and other clinical/laboratory variables (CLVs). Methods Well-controlled PWH (n=36) underwent baseline and follow-up FDG PET/CT obtained 3.5 years apart on average. Longitudinal changes in whole brain (WB) and regional relative FDG uptake, brain volumes, CLVs, CSF cytokines and neuropsychological measures were measured. A variable selection model identified baseline variables related to future brain metabolic changes while multivariable models explored neuropsychological implications of brain metabolism and volumetric. Results High ASCVD scores predicted future decreased thalamic uptake (slope=-0.0068, p=0.027) and decreasing thalamic uptake correlated with worsening cognition (slope=15.80, p=0.020). Despite longitudinal greater than expected gray matter loss, WB FDG uptake did not change over the follow-up period. Most CSF cytokines decreased longitudinally but were not predictive of FDG changes. Conclusions We found that high ASCVD scores in a group of treated PWH were related to thalamic hypometabolism, which in turn correlated with neurocognitive decline. Our findings support the contribution of CVD to neurocognitive dysfunction. More proactive CVD management may have a role in mitigating progression of cognitive impairment. Lack of change in global brain glucose metabolism despite documented accelerated gray matter volume loss over the same period suggests that FDG PET might underestimate neuronal injury in PWH compared to structural MRI.