Older adults in more disadvantaged neighborhoods exhibit brain vascular dysfunction.

Neighborhood disadvantage is a risk factor for dementia, but the mechanisms involved are not well understood. In this study, we explored the relationship between neighborhood deprivation and whole-brain cerebrovascular reactivity (CVR) in 132 older adults without a history of clinical stroke or dementia. Participants underwent brain MRI and venipuncture. Relative neighborhood deprivation was quantified using the Area Deprivation Index. Spontaneous CVR was calculated as the percent change in resting cerebral blood flow per unit change in end-tidal CO2. Greater neighborhood deprivation was associated with lower whole-brain CVR when adjusted for age and sex (p = 0.027). Further adjustment for APOE ε4 carrier status, vascular risk factors, and plasma Alzheimer's disease (AD) biomarker p-tau217 did not alter the results. These findings show that older adults in more disadvantaged environments exhibit reduced cerebrovascular function, independent of traditional vascular risk and AD-related pathology. However, further investigation with more diverse samples and a life-course model is warranted to better understand these microvascular differences.