Relationships between cerebral tau and glucose metabolism in cognitively normal older adults

Background Alzheimer’s disease (AD) is characterised by the accumulation of amyloid-β and tau in brain subsequent neurodegeneration. The relationship between glucose metabolism has been elucidated AD, however two early stages AD trajectory remains elusive. Here, we examine this using fluorodeoxyglucose (FDG) flortaucipir (FTP) positron emission tomography (PET) a cohort cognitively normal older adults. Method 72 participants (mean±SD age 78.7±6.3 years old) were recruited through Harvard Ageing Brain Study had available FDG-PET, FTP-PET, structural MRI scans. Region interest analysis was utilised to determine regional uptake each PET tracer. 40 split into high-tau low-tau groups based on highest 20 lowest FTP values from medial temporal lobe excluding hippocampus (MTL (no hippocampus)). FDG compared groups, while correlations examined. Result Glucose significantly higher group than whole (p = 0.023), frontal 0.028), 0.014), parietal 0.027), MTL 0.01), hippocampus) 0.002), anterior cingulate cortex 0.045), posterior 0.023). Significant negative found (r -0.317,p 0.046), -0.383,p 0.015), -0.316,p 0.047), -0.437, p 0.005), -0.444,p 0.004), -0.320,p 0.044), -0.361,p 0.022). negatively correlated with -0.326, 0.04) -0.337,p 0.034). Conclusion High levels associated hypometabolism adults, suggesting that may cause decreased without inducing cognitive deficits. Furthermore, highlight link neurodegeneration before onset decline. association reduced supports need for research intervention be aimed at preclinical AD.