Clinical Research Studies

The current biomarker classification system (i.e., the ATN model) may not fully account for racial disparity and can’t explain the increased prevalence in blacks of both AD and vascular risk factors for AD such as diabetes and hypertension when compared to whites. Postmortem studies suggest that loss of LC neurons better predicts severity of AD clinical symptoms than Aß/neurofibrillary tangle pathology in any other cortical/subcortical brain region. Our decade-long studies in humans have demonstrated a special vulnerability of LC to aging and stress. Further, our preliminary data in black and white subjects reveals that the decline rate of LC neurons is much faster in blacks starting in the mid-30s, particularly in black males. We now aim to test the hypothesis that cumulative exposure to socioeconomic disadvantage and racial discrimination may cause long-lasting changes in LC function followed by LC neuronal loss, which would explain the different AD phenotypical presentation among blacks; by asking120 cognitively normal older adults (80 blacks and 40 whites) to perform clinical evaluation, cognitive measurement, biomarkers (ATN and vascular markers) assessment, stress and discrimination scale testing, and one [11C]MRB PET-MR scan to determine NET availability.