Lower complexity and higher variability in beat-to-beat systolic blood pressure are associated with elevated long-term risk of dementia: The Rotterdam Study.
Ma Yuan,Zhou Junhong,Kavousi Maryam,Lipsitz Lewis A,Mattace-Raso Francesco,Westerhof Berend E,Wolters Frank J,Wu Julia W,Manor Brad,Ikram M Kamran,Goudsmit Jaap,Hofman Albert,Ikram M Arfan
Alzheimer's & dementia : the journal of the Alzheimer's Association
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.
Diastolic Blood Pressure Variability in Later Life May Be a Key Risk Marker for Cognitive Decline.
Hypertension (Dallas, Tex. : 1979)
BACKGROUND:There is an increasing awareness of the need to understand the interaction between long-term blood pressure patterns and their impact on the brain and cognition. METHODS:Our aim was to investigate the relationship between repeated blood pressure measures and change in cognitive performance over 12 years and imaging data at 12 years using a longitudinal population study. The data consisted of 2 cohorts, one midlife and one later life. Using linear regression, we examined the relationship between blood pressure (systolic, diastolic, change in blood pressure between visits, and visit-to-visit variability), change in cognitive performance and imaging at 12 years. RESULTS:Data on cognitive change were available in 1054 at midlife, baseline age 42.7 (SD 1.5) and 1233 in later life, 62.5 (1.5) years. Imaging data were available in 168 and 233, respectively. After adjustment for multiple comparisons greater diastolic blood pressure variability in later life was associated with a -1.95 point decline (95% CI, -2.89 to -1.01) on an attention-based task and a -0.42 point (95% CI, -0.68 to -0.15) decline in performance on a psychomotor task. A higher SD in diastolic pressure across follow-up was associated with greater white matter hyperintensity volume (%increase per 10 mm Hg increase in the SD [1.50 (95% CI, 1.16-1.94]). CONCLUSIONS:In a largely normotensive/mildly hypertensive population, our analyses reported no relationships between blood pressure and cognition in midlife but a potential role for diastolic blood pressure variability in later life as a risk marker for cognitive decline. This may indicate an at-risk period or a means to identify an at-risk population at the age where diastolic pressure is starting to decline.