JCBFM_Billinger2017.pdf

<p>The goal of this study was to explore the association of beta-amyloid accumulation and<b><i></i></b>cerebrovascular response (CVR) in cognitively normal older adults. Beta-amyloid accumulation was characterized with [18F] Florbetapir positron emission tomography scans. CVR was calculated as middle cerebral artery blood flow velocity change from rest to moderate intensity exercise. We found that individuals with elevated beta-amyloid aggregation had a blunted CVR (n = 25, age 70.1 ± 4.8; 3.3 ± 3.7cm/s) compared to non-elevated individuals (n = 45,age 72.0 ± 4.9; 7.2 ± 5.0 cm/s,<i>p </i>< 0.001). Further, greater beta-amyloid burden was linearly associated with less CVR across all participants (b = -11.7, <i>p</i><0.001). Greater CVR and less beta-amyloid burden were associated with Processing Speed (p<0.05). This study is the first to show that CVR from rest to exercise is blunted across increased global beta-amyloid burden.</p>