The Association between Blood Pressure Variability and Dementia and Cognitive Impairment: A Meta-Analysis

Abstract

Background: Blood pressure irregularities are the precursor to all vascular diseases. Elevated systolic blood pressure (BP) is the leading cause of death and disability worldwide. Similarly, the burden of dementia is on the rise. BP variability (BPV) has been suggested to be able to predict dementia and cognitive impairment more accurately than mean BP. A body of literature has shown the link between increased BPV, a high average BP, cognitive impairment, and incident dementia. However, the extent of this association is controversial, and remains unknown. Aim: To identify the magnitude of the association between BPV, cognitive impairment, and incident dementia. Meta-Analysis: Eleven studies, comprised of 52, 784 individuals, were identified after a comprehensive search of the Embase, PsychINFO, PubMed, and Scopus databases. Data was extracted and prepared to calculate risk ratios with 95% confidence intervals. Forest plots were created. Heterogeneity was identified and publication bias was assessed. Results: Systolic BPV was significantly associated with cognitive impairment [RR: 1.29; 95% CI 1.06 – 1.57; p = 0.01] and overall cognitive decline [RR: 1.23; 95% CI 1.08 – 1.40; p = 0.001]. Conclusion: This meta-analysis has clinical implications on potential clinical interventions and treatments for dementia and cognitive impairment. It may also aid in healthcare policy regarding patient BP monitoring and modulation. We live in a world with an increasingly ageing population, which makes the present a critical time to uncover the relationship between BPV and dementia and cognitive impairment. Keywords: blood pressure variability, dementia, cognitive impairment, cognitive decline