Blunted cerebrovascular response is associated with elevated beta

The goal of this study was to explore the association of beta-amyloid accumulation and 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？±？3.7？cm/s) compared to non-elevated individuals (n？=？45, age 72.0？±？4.9; 7.2？±？5.0？cm/s, p？<？0.001). Further, greater beta-amyloid burden was linearly associated with less CVR across all participants (b？=？？11.7, p？<？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