Antemortem visit‐to‐visit blood pressure variability and postmortem cerebrovascular disease lesion burden in older adults without dementia

Abstract

AbstractBackgroundBlood pressure management is an accessible therapeutic target for dementia prevention. Beyond the current focus of managing mean levels, there is a burgeoning interest in understanding the variability in blood pressure levels. Emerging research suggests elevated blood pressure variability is associated with increased risk for Alzheimer’s dementia and cerebrovascular disease, including white matter hyperintensities on MRI (e.g., Fazekas score), but relationships with white matter lesions and overall cerebrovascular pathology at autopsy remain understudied. The aim of the current study was to determine whether antemortem blood pressure variability predicts cerebrovascular pathology in older adults without clinical dementia.Method1866 older adults from the National Alzheimer’s Coordinating Center study underwent repeated approximately annual blood pressure measurement and autopsy and were free of clinical dementia at study baseline. Visit‐to‐visit blood pressure variability was calculated as variability independent of mean using at least 3 (median 5, range 3 ‐ 15) annual blood pressure measurements. White matter rarefaction was scored as none vs mild/moderate vs severe. An index of overall cerebrovascular lesion burden (range 0‐7) was calculated as the sum of severity (0‐2) of atherosclerosis in the Circle of Willis and arteriolosclerosis, and the presence/absence (0‐1) of microinfarcts, infarcts and lacunes, and microbleeds and hemorrhages. Linear and multinomial logistic regression models examined relationships between blood pressure variability, white matter rarefaction severity, and overall cerebrovascular lesion burden, controlling for age, sex, mean blood pressure, antihypertensive use, and Hachinski Ischemic Score, among other variables.ResultElevated blood pressure variability predicted increased severity of white matter rarefaction (OR of mild/moderate [vs none] = 1.21 [1.06, 1.33], p = .004; OR of severe [vs none] = 1.30 [1.07, 1.46], p = .008), and greater overall cerebrovascular lesion burden (ß = .12 [.11, .42]; p < .0001).ConclusionElevated blood pressure variability is related to postmortem cerebrovascular lesion burden, including increased severity of white matter rarefaction, in older adults without clinical dementia, independent of mean blood pressure. Findings are consistent with studies using MRI‐based markers of cerebrovascular disease and may help improve blood pressure as a risk indicator for dementia and cerebrovascular disease.