Lower complexity and higher variability in beat-to-beat systolic blood pressure are associated with elevated long-term risk of dementia: The Rotterdam Study

Introduction We hypothesized that subclinical disruption in blood pressure (BP) dynamics, captured by lower complexity and higher variability, may contribute to dementia risk, above and beyond BP levels. Methods This prospective cohort study followed 1835 older adults from 1997 to 2016, with BP complexity quantified by sample entropy and BP variability quantified by coefficient of variation using beat-to-beat BP measured at baseline. Results Three hundred thirty-four participants developed dementia over 20 years. Reduced systolic BP (SBP) complexity was associated with a higher risk of dementia (hazard ratio [HR] comparing extreme quintiles: 1.55; 95% confidence interval [CI]: 1.09-2.20). Higher SBP variability was also associated with a higher risk of dementia (HR comparing extreme quintiles: 1.57; 95% CI: 1.11-2.22. These findings were observed after adjusting for age, sex, apolipoprotein E (APOE) genotype, mean SBP, and other confounding factors. Discussions Our findings suggest that lower complexity and higher variability of beat-to-beat SBP are potential novel risk factors or biomarkers for dementia.