Enlarged Perivascular Spaces Are Independently Associated with High Pulse Wave Velocity: A Cross-Sectional Study.

Background: Recent studies have demonstrated an association between pulse wave velocity (PWV), cerebral small vessel disease (SVD), and cognitive impairment such as Alzheimer's disease. However, the association between brachial-ankle PWV and enlarged perivascular spaces (EPVS), one component of cerebral SVD remains controversial. Objective: To investigate the relationship between brachial-ankle PWV and EPVS severity in participants without dementia. Methods: We performed a cross-sectional study of data of 74 participants from sub-analysis of ongoing research. We assessed cognitive function, brachial-ankle PWV, and brain magnetic resonance imaging (MRI) features. Using brain MRI, EPVS were separately assessed as basal ganglia (BG)-EPVS or centrum semiovale (CSO)-EPVS on the basis of their location. The relationship between EPVS severity and brachial-ankle PWV was evaluated using multivariable ordinal logistic regression analyses. Results: We analyzed 74 participants (women: 47%, mean age: 73 years, mild cognitive impairment [MCI]: 74%). Compared with participants with normal cognition, those with MCI were more likely to have both severe BG-EPVS and severe CSO-EPVS. In multivariable analyses, high brachial-ankle PWV and age were independently associated with BG-EPVS severity (odds ratio [95% confidence interval]: 1.19 [1.02-1.38], 1.09 [1.01-1.17], respectively), whereas only age was independently associated with CSO-EPVS severity. A causal mediation analysis under a counterfactual approach revealed a significant pure natural indirect effect of brachial-ankle PWV on MCI that was mediated by BG-EPVS (estimate: 1.04, 95% CI: 1.01-1.12, p = 0.006). Conclusions: Brachial-ankle PWV was associated with BG-EPVS severity. High PWV may cause cerebrovascular pulsatility, which accelerates BG-EPVS and may worsen cognitive impairment.