Pulse wave velocity is associated with β-amyloid deposition in the brains of very elderly adults

Objective: To determine arterial stiffness and beta-amyloid (A beta) deposition in the brain of dementia-free older adults. Methods: We studied a cohort of 91 dementia-free participants aged 83-96 years. In 2009, participants completed brain MRI and PET imaging using Pittsburgh compound B (PiB; a marker of amyloid plaques in human brain). In 2011, we measured resting blood pressure (BP), mean arterial pressure (MAP), and arterial stiffness by pulse wave velocity (PWV) in the central, peripheral, and mixed (e.g., brachial ankle PWV [baPWV]) vascular beds, using a noninvasive and automated waveform analyzer. Results: A total of 44/91 subjects were Ab-positive on PET scan. Ab deposition was associated with mixed PWV, systolic BP, and MAP. One SD increase in baPWV resulted in a 2-fold increase in the odds of being Ab-positive (p = 0.007). High white matter hyperintensity (WMH) burden was associated with increased central PWV, systolic BP, and MAP. Compared to Ab-negative individuals with low WMH burden, each SD increase in PWV was associated with a 2-fold to 4-fold increase in the odds of being A beta-positive and having high WMH. Conclusions: Arterial stiffness was associated with A beta plaque deposition in the brain, independent of BP and APOE epsilon 4 allele. The associations differed by type of brain abnormality and vascular bed measured (e.g., WMH with central stiffness and A beta deposition and mixed stiffness). Arterial stiffness was highest in individuals with both high A beta deposition and WMH, which has been suggested to be a "double hit" contributing to the development of symptomatic dementia.