Elevated cerebrovascular resistance index is associated with cognitive dysfunction in the very-old

Evaluation of the correlation between cerebral hemodynamics and blood pressure by comparative analysis of variation in cerebral blood flow in hypertensive versus normotensive individuals: A systematic review and meta-analysis

Current understanding of the cerebral vascular response to variations in blood pressure (BP) among individuals with hypertension is limited. The aim of this meta-analysis was to determine the correlation between hypertension, risk of stroke, and cerebral blood flow (CBF). We reviewed studies published between 2000 and 2023 from PubMed, Google Scholar, and Science Direct that compared mean CBF in normotensive (NTN) and hypertensive (HTN) patients. A random effects model was used to construct the risk ratio (RR), 95% confidence interval (CI), forest plot, and inverse variance weighting. Additionally, a mixed-effects meta-regression was employed to examine the impact of study-specific patient variables. This meta-analysis included eight prospective cross-sectional studies published from 2002 to 2023. It revealed a significant average difference in the standard mean CBF of -0.45 (95% CI -0.60 to -0.30, I2 = 69%, P < 0.00001), distinguishing NTN from HTN subjects. A RR of 0.90 (95% CI 0.63 to 1.30, I2 = 89%, P = 0.04) indicated a significant decrease in CBF among individuals with hypertension. We found a statistically significant relationship between changes in diastolic and systolic BPs and the mean CBF (R -0.81, P = 0.001 and R = -0.90, P = 0.005, respectively). Our research demonstrates a strong relationship between elevated BP and reduced CBF, with hypertension reducing CBF compared to NTN individuals, by increasing cerebrovascular resistance.

Contrast-enhanced ultrasound imaging detects anatomical and functional changes in rat cervical spine microvasculature with normal aging

Normal aging is associated with significant deleterious cerebrovascular changes; these have been implicated in disease pathogenesis and increased susceptibility to ischemic injury. While these changes are well documented in the brain, few studies have been conducted in the spinal cord. Here, we utilize specialized contrast-enhanced ultrasound (CEUS) imaging to investigate age-related changes in cervical spinal vascular anatomy and hemodynamics in male Fisher 344 rats, a common strain in aging research. Aged rats (24-26 mo., N=6) exhibited significant tortuosity in the anterior spinal artery and elevated vascular resistance compared to adults (4-6 mo., N=6; tortuosity index 2.20±0.15 vs 4.74±0.45, p<0.05). Baseline blood volume was lower in both larger vessels and the microcirculation in the aged cohort, specifically in white matter (4.44e14±1.37e13 vs 3.66e14±2.64e13 CEUS bolus AUC, p<0.05). To elucidate functional differences, animals were exposed to a hypoxia challenge; whereas adult rats exhibited significant functional hyperemia in both gray and white matter (GM: 1.13±0.10-fold change from normoxia, p<0.05; WM: 1.16±0.13, p<0.05), aged rats showed no response. Immunohistochemistry revealed reduced pericyte coverage and activated microglia behavior in aged rats, which may partially explain the lack of vascular response. This study provides the first in vivo description of age-related hemodynamic differences in the cervical spinal cord.

Cerebrovascular adaptations to habitual resistance exercise with aging

Resistance training (RT) is associated with improved metabolism, bone density, muscular strength, and lower risk of osteoporosis, sarcopenia, and cardiovascular disease. Although RT imparts many physiological benefits, cerebrovascular adaptations to chronic RT are not well defined. Participation in RT is associated with greater resting peripheral arterial diameters, improved endothelial function, and general cardiovascular health, whereas simultaneously linked to reductions in central arterial compliance. Rapid blood pressure fluctuations during resistance exercise, combined with reduced arterial compliance, could lead to cerebral microvasculature damage and subsequent cerebral hypoperfusion. Reductions in cerebral blood flow (CBF) accompany normal aging, where chronic reductions in CBF are associated with changes in brain structure and function, and increased risk of neurodegeneration. It remains unclear whether reductions in arterial compliance with RT relate to subclinical cerebrovascular pathology, or if such adaptations require interpretation in the context of RT specifically. The purpose of this narrative review is to synthesize literature pertaining to cerebrovascular adaptations to RT at different stages of the life span. This review also aims to identify gaps in the current understanding of the long-term impacts of RT on cerebral hemodynamics and provide a mechanistic rationale for these adaptations as they relate to aging, cerebral vasculature, and overall brain health.

Self-reported fraud victimization and objectively measured blood pressure: Sex differences in post-fraud cardiovascular health

BACKGROUND

Over 5 million older Americans are victims of financial exploitation, schemes, and/or scams per year. Such victimization is associated with increased hospitalizations, admittance to skilled nursing facilities, and lower 5-year all-cause mortality survival rates. Despite this, associations with medical comorbidities like elevated blood pressure (BP) have not been examined.

METHODS

We investigated the association of self-reported fraud victimization (presence/absence) with objectively measured BP metrics leveraging cross-sectional and longitudinal data from over 1200 non-demented adults (75% female; age ~81 years) from the Rush Memory and Aging Project. We first examined cross-sectional associations between baseline fraud victimization and BP, then used longitudinal data to test the hypothesis that fraud victimization is associated with increases in BP after incident fraud. During up to 11 years of annual observation, participants were queried for fraud victimization and underwent serial BP measurements to calculate per visit averages of systolic and diastolic BP, mean arterial pressure (MAP), and pulse pressure.

RESULTS

Cross-sectional analyses established that fraud victimization at baseline was associated with higher BP values. Next, using longitudinal changepoint analyses, we showed that fraud victimization was associated with elevations in BP among men but not women. Specifically, men who reported incident fraud exhibited increases in all BP metrics post-fraud.

CONCLUSION

Results suggest an important link between fraud victimization and BP, particularly among men. Older men showed significant elevations in BP after incident fraud that, compounded over time, may portend other adverse health outcomes.

Cortical Anoxic Spreading Depolarization During Cardiac Arrest is Associated with Remote Effects on Peripheral Blood Pressure and Postresuscitation Neurological Outcome

BACKGROUND

Spreading depolarizations (SDs) are self-propagating waves of neuronal and glial depolarizations often seen in neurological conditions in both humans and animal models. Because SD is thought to worsen neurological injury, the role of SD in a variety of cerebral insults has garnered significant investigation. Anoxic SD is a type of SD that occurs because of anoxia or asphyxia. Although asphyxia leading to a severe drop in blood pressure may affect cerebral hemodynamics and is widely known to cause anoxic SD, the effect of anoxic SD on peripheral blood pressure in the extremities has not been investigated. This relationship is especially important to understand for conditions such as circulatory shock and cardiac arrest that directly affect both peripheral and cerebral perfusion in addition to producing anoxic SD in the brain.

METHODS

In this study, we used a rat model of asphyxial cardiac arrest to investigate the role of anoxic SD on cerebral hemodynamics and metabolism, peripheral blood pressure, and the relationship between these variables in 8- to 12-week-old male rats. We incorporated a multimodal monitoring platform measuring cortical direct current simultaneously with optical imaging.

RESULTS

We found that during anoxic SD, there is decoupling of peripheral blood pressure from cerebral blood flow and metabolism. We also observed that anoxic SD may modify cerebrovascular resistance. Furthermore, shorter time difference between anoxic SDs measured at different locations in the same rat was associated with better neurological outcome on the basis of the recovery of electrocorticography activity (bursting) immediately post resuscitation and the neurological deficit scale score 24 h post resuscitation.

CONCLUSIONS

To our knowledge, this is the first study to quantify the relationship between peripheral blood pressure, cerebral hemodynamics and metabolism, and neurological outcome in anoxic SD. These results indicate that the characteristics of SD may not be limited to cerebral hemodynamics and metabolism but rather may also encompass changes in peripheral blood flow, possibly through a brain-heart connection, providing new insights into the role of anoxic SD in global ischemia and recovery.

Potential Mechanisms Underlying Resistance to Dementia in Non-Demented Individuals with Alzheimer's Disease Neuropathology

Alzheimer’s disease (AD) is the most common form of dementia and typically characterized by the accumulation of amyloid-β plaques and tau tangles. Intriguingly, there also exists a group of elderly which do not develop dementia during their life, despite the AD neuropathology, the so-called non-demented individuals with AD neuropathology (NDAN). In this review, we provide extensive background on AD pathology and normal aging and discuss potential mechanisms that enable these NDAN individuals to remain cognitively intact. Studies presented in this review show that NDAN subjects are generally higher educated and have a larger cognitive reserve. Furthermore, enhanced neural hypertrophy could compensate for hippocampal and cingulate neural atrophy in NDAN individuals. On a cellular level, these individuals show increased levels of neural stem cells and ‘von Economo neurons’. Furthermore, in NDAN brains, binding of Aβ oligomers to synapses is prevented, resulting in decreased glial activation and reduced neuroinflammation. Overall, the evidence stated here strengthens the idea that some individuals are more resistant to AD pathology, or at least show an elongation of the asymptomatic state of the disease compared to others. Insights into the mechanisms underlying this resistance could provide new insight in understanding normal aging and AD itself. Further research should focus on factors and mechanisms that govern the NDAN cognitive resilience in order to find clues on novel biomarkers, targets, and better treatments of AD.

Arterial stiffening acts synergistically with APOE genotype and AD biomarker status to influence memory in older adults without dementia

BACKGROUND

Arterial stiffening has emerged as an important risk factor for Alzheimer's disease (AD) and related dementias. Carotid-femoral pulse wave velocity has been proposed as a non-invasive and reproducible method to assess arterial stiffness. However, the association of pulse wave velocity with performance across multiple cognitive domains as well as interactions with in vivo AD biomarkers and apolipoprotein E (APOE) genotype has received limited study.

METHOD

We studied 193 older adult volunteers (167 with normal cognition and 26 with mild cognitive impairment) who underwent comprehensive medical and neuropsychological evaluation at the University of California, San Diego Alzheimer's Disease Research Center. Cerebrospinal fluid (CSF) biomarkers were available on 123 participants (63%). Linear models examined whether pulse wave velocity significantly interacted with APOE ε4 status and CSF AD biomarker positivity (based on the ratio of total tau over beta-amyloid [tau/Aβ42]) on memory, language, executive functioning, attention, and visuospatial abilities.

RESULTS

After adjusting for demographic characteristics and vascular risk burden, across the entire sample, pulse wave velocity was associated with poorer executive functioning but not the performance in the other cognitive domains. When the modifying effects of AD genetic risk and CSF AD biomarkers were considered, pulse wave velocity interacted with APOE genotype and CSF tau/Aβ ratio such that a stronger association between elevated pulse wave velocity and poorer memory performance was found among those positive for CSF and genetic AD markers. There were no significant interaction effects for non-memory cognitive domains.

CONCLUSION

The findings suggest that pulse wave velocity, a non-invasive method to assess arterial wall properties, may be a useful marker of risk for cognitive decline, particularly among individuals who are APOE ε4 carriers or CSF AD biomarke0r-positive.

Effects of cardiorespiratory fitness and exercise training on cerebrovascular blood flow and reactivity: a systematic review with meta-analyses

We address two aims: Aim 1 (Fitness Review) compares the effect of higher cardiorespiratory fitness (CRF) (e.g., endurance athletes) with lower CRF (e.g., sedentary adults) on cerebrovascular outcomes, including middle cerebral artery velocity (MCAv), cerebrovascular reactivity and resistance, and global cerebral blood flow, as assessed by transcranial Doppler (TCD) or magnetic resonance imaging (MRI). Aim 2 (Exercise Training Review) determines the effect of exercise training on cerebrovascular outcomes. Systematic review of studies with meta-analyses where appropriate. Certainty of evidence was assessed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Twenty studies (18 using TCD) met the eligibility criteria for Aim 1, and 14 studies (8 by TCD) were included for Aim 2. There was a significant effect of higher CRF compared with lower CRF on cerebrovascular resistance (effect size = -0.54, 95% confidence interval = -0.91 to -0.16) and cerebrovascular reactivity (0.98, 0.41-1.55). Studies including males only demonstrated a greater effect of higher CRF on cerebrovascular resistance than mixed or female studies (male only: -0.69, -1.06 to -0.32; mixed and female studies: 0.10, -0.28 to 0.49). Exercise training did not increase MCAv (0.05, -0.21 to 0.31) but showed a small nonsignificant improvement in cerebrovascular reactivity (0.60, -0.08 to 1.28; P = 0.09). Exercise training showed heterogeneous effects on regional but little effect on global cerebral blood flow as measured by MRI. High CRF positively effects cerebrovascular function, including decreased cerebrovascular resistance and increased cerebrovascular reactivity; however, global cerebral blood flow and MCAv are primarily unchanged following an exercise intervention in healthy and clinical populations.NEW & NOTEWORTHY Higher cardiorespiratory fitness is associated with lower cerebrovascular resistance and elevated cerebrovascular reactivity at rest. Only adults with a true-high fitness based on normative data exhibited elevated middle cerebral artery velocity. The positive effect of higher compared with lower cardiorespiratory fitness on resting cerebrovascular resistance was more evident in male-only studies when compared with mixed or female-only studies. A period of exercise training resulted in negligible changes in middle cerebral artery velocity and global cerebral blood flow, with potential for improvements in cerebrovascular reactivity.

Association Between Doppler Snuffbox Resistive Index and Tissue Perfusion in Septic Patients

BACKGROUND

Peripheral vascular disorders leading to tissue hypoperfusion play a central role in the pathophysiology of organ failure in septic shock. The Doppler snuffbox resistive index (SBRI) can be an accurate parameter to evaluate the status of peripheral vasculature at the bedside. We evaluated whether the SBRI is related to lactate levels or the peripheral perfusion index (PI) and its ability to predict lactate clearance in septic patients.

METHODS

We conducted a prospective observational study in a tertiary general and teaching hospital in China. From July 2019 to December 2019, all consecutive adult patients with septic shock who required intensive care unit admission were included. At the same time, 20 stable postoperative patients were studied as a control group. We recorded the hemodynamic parameters, including the SBRI and PI, which were measured simultaneously after patient recruitment.

RESULTS

We evaluated 44 patients with septic shock in the study group and 20 stable postoperative patients in the control group. Patients with septic shock had higher Sequential Organ Failure Assessment scores, procalcitonin levels, cardiac index (CI) and lactate levels than patients in the control group. The SBRI was correlated with the PI and lactate level. The CI was not correlated with lactate level in the patients examined. Based on lactate clearance in the first 6 h, the septic shock patients were divided into two groups: one with lactate clearance ≥20% (n = 28) and the other with lactate clearance <20% (n = 16). The CI was not significantly different between the two groups. The SBRI of the lactate clearance <20% group was higher than that of the lactate clearance ≥20% group and the control group. The PI of the lactate clearance <20% group was lower than that of the lactate clearance ≥20% group and the control group. The SBRI cutoff value for predicting 6-h lactate clearance after resuscitation was ≥1.09, with a sensitivity of 68.8% and a specificity of 85.7%. The PI cutoff value for predicting 6-h lactate clearance after resuscitation was ≤0.99, with a sensitivity of 64.3% and a specificity of 81.2%. The SBRI was significantly better than the PI for predicting 6-h lactate clearance after resuscitation (area under the curve: 0.805 vs. 0.703, P < 0.05).

CONCLUSIONS

The Doppler SBRI is correlated with tissue perfusion parameters in critically ill patients. An abnormal SBRI may be better than the PI for predicting poor lactate clearance in septic patients. Further investigations are required to determine whether correcting an abnormal SBRI and PI may improve the success rate of septic shock resuscitation.

Associations of decision making abilities with blood pressure values in older adults

OBJECTIVES

Decision making, key to successful aging, has implications for financial success, physical health, and well being. While poor decision making has been linked with increased risk of mortality, age-related cognitive decline, and dementia, less is known regarding its associations with chronic disease indicators. We investigated the associations of decision making with blood pressure (BP) values [i.e., SBP, mean arterial pressure (MAP), and pulse pressure (PP), separately] in a community-based cohort study of aging.

METHODS

Participants were 908 nondemented older adults (age ∼81 years; 75% women) from the Rush Memory and Aging Project. Decision making was measured using questions designed to simulate materials used in financial and healthcare settings in the real world and yielded a total score and domain-specific health and financial decision making scores. Two seated and one standing BP measurement were taken with all three contributing to average SBP, MAP that is, [SBP + (2 × DBP)]/3, and PP, that is, SBP - DBP. Participants were queried about hypertension status and antihypertension medications were visually inspected and coded. Participants also underwent medical history and cognitive assessments.

RESULTS

In separate multivariable linear regression models, total decision making scores were inversely associated with SBP, MAP, and PP after adjusting for age, sex, education, antihypertension medication use, diabetes, and cumulative cardiovascular disease burden (P values = 0.03). Decision making remained associated with these BP values after additional adjustment for global cognition.

CONCLUSION

Poorer decision making is associated with higher BP values in nondemented older adults.

APOE genotype modifies the association between central arterial stiffening and cognition in older adults

Arterial stiffening is associated with cognitive impairment and prodromal Alzheimer's disease. This study tested the interaction between arterial stiffening and an Alzheimer's disease genetic risk factor (apolipoprotein E [APOE] genotype) on cognition among older adults. Vanderbilt Memory & Aging Project participants with normal cognition (n = 162, 72 ± 7 years, 29% APOE-ε4 carrier) and mild cognitive impairment (n = 121, 73 ± 8 years, 42% APOE-ε4 carrier) completed neuropsychological assessment and cardiac MRI to assess aortic stiffening using pulse wave velocity (PWV, m/s). Linear regression models stratified by cognitive diagnosis related aortic PWV × APOE-ε4 status to neuropsychological performances, adjusting for demographic and vascular risk factors. PWV × APOE-ε4 related to poorer performance on measures of lexical retrieval (β = -0.29, p = 0.01), executive function (β = -0.44, p = 0.02), and episodic memory (β = -3.07, p = 0.02). Among participants with higher aortic PWV, APOE-ε4 modified the association between central arterial stiffening and cognition, such that carriers had worse performances than noncarriers. Findings add to a growing body of evidence for APOE-vascular interactions on cognition in older adults and warrant further research into less heart-healthy cohorts where the association between PWV and cognition among older adults might be stronger.

Detrimental effect of systemic vascular risk factors on brain hemodynamic function assessed with MRI

Background and purpose Vascular risk factors have been associated with decreased cerebral blood flow (CBF) but this is etiologically nonspecific and may result from vascular insufficiency or a response to decreased brain metabolic activity. We apply new MRI techniques to measure oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen consumption (CMRO₂), hypothesizing that decreased CBF related to these vascular risk factors will be associated with increased OEF, confirming a primary vascular insufficiency. Methods 3T MRI was obtained on 70 community-based participants in this IRB-approved study with informed consent, with previous assessment of systolic blood pressure, hypertension medication, elevated serum triglycerides, low serum HDL, and diabetes mellitus. CBF was measured using phase contrast adjusted for brain volume (ml/100 g/min), OEF (%) was obtained from T2-Relaxation-Under-Spin-Tagging (TRUST), and CMRO₂ (μmol/100 g/min) was derived using the Fick principle. Stepwise linear regression identified optimal predictors of CBF with age, sex, and hematocrit included for adjustment. This predictive model was then evaluated against OEF and CMRO₂. Results Hypertriglyceridemia was associated with low CBF and high OEF. High systolic blood pressure was associated with high CBF and low OEF, which was primarily attributable to those with pressures above 160 mmHg. Neither risk factor was associated with significant differences in cerebral metabolic rate. Conclusion Low CBF related to hypertriglyceridemia was accompanied by high OEF with no significant difference in CMRO₂, confirming subclinical vascular insufficiency. High CBF related to high systolic blood pressure likely reflected limitations of autoregulation at higher blood pressures.

The Role of Exercise-Induced Cardiovascular Adaptation in Brain Health

Regular aerobic exercise improves brain health; however, a potential dose-response relationship and the underling physiological mechanisms remain unclear. Existing data support the following hypotheses: 1) exercise-induced cardiovascular adaptation plays an important role in improving brain perfusion, structure, and function, and 2) a hormetic relation seems to exist between the intensity of exercise and brain health, which needs to be further elucidated.

Brain imaging of neurovascular dysfunction in Alzheimer's disease

Neurovascular dysfunction, including blood-brain barrier (BBB) breakdown and cerebral blood flow (CBF) dysregulation and reduction, are increasingly recognized to contribute to Alzheimer's disease (AD). The spatial and temporal relationships between different pathophysiological events during preclinical stages of AD, including cerebrovascular dysfunction and pathology, amyloid and tau pathology, and brain structural and functional changes remain, however, still unclear. Recent advances in neuroimaging techniques, i.e., magnetic resonance imaging (MRI) and positron emission tomography (PET), offer new possibilities to understand how the human brain works in health and disease. This includes methods to detect subtle regional changes in the cerebrovascular system integrity. Here, we focus on the neurovascular imaging techniques to evaluate regional BBB permeability (dynamic contrast-enhanced MRI), regional CBF changes (arterial spin labeling- and functional-MRI), vascular pathology (structural MRI), and cerebral metabolism (PET) in the living human brain, and examine how they can inform about neurovascular dysfunction and vascular pathophysiology in dementia and AD. Altogether, these neuroimaging approaches will continue to elucidate the spatio-temporal progression of vascular and neurodegenerative processes in dementia and AD and how they relate to each other.

The Utility of Cerebral Blood Flow as a Biomarker of Preclinical Alzheimer's Disease

There is accumulating evidence suggesting that changes in brain perfusion are present long before the clinical symptoms of Alzheimer's disease (AD), perhaps even before amyloid-β accumulation or brain atrophy. This evidence, consistent with the vascular hypothesis of AD, implicates cerebral blood flow (CBF) in the pathogenesis of AD and suggests its utility as a biomarker of preclinical AD. The extended preclinical phase of AD holds particular significance for disease modification, as treatment would likely be most effective in this early asymptomatic stage of disease. This highlights the importance of identifying reliable and accurate biomarkers of AD that can differentiate normal aging from preclinical AD prior to clinical symptom manifestation. Cerebral perfusion, as measured by arterial spin labeling magnetic resonance imaging (ASL-MRI), has been shown to distinguish between normal controls and adults with AD. In addition to demonstrating diagnostic utility, CBF has shown usefulness as a tool for identifying those who are at risk for AD and for predicting subtle cognitive decline and conversion to mild cognitive impairment and AD. Taken together, this evidence not only implicates CBF as a useful biomarker for tracking disease severity and progression, but also suggests that ASL-measured CBF may be useful for identifying candidates for future AD treatment trials, especially in the preclinical, asymptomatic phases of the disease.

Pulse pressure in relation to tau-mediated neurodegeneration, cerebral amyloidosis, and progression to dementia in very old adults

IMPORTANCE

Increased pulse pressure associated with age-related arterial stiffening increases risk for Alzheimer dementia but the mechanism responsible for this association remains unclear.

OBJECTIVES

To determine the relationship between pulse pressure and cerebral spinal fluid biomarker profiles of preclinical Alzheimer disease, investigate whether observed relationships are stronger in adults with more advanced arterial age (≥80 years of age), and examine the relationship between pulse pressure and progression to dementia.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cohort study, 877 participants without dementia (55-91 years of age) from the Alzheimer's Disease Neuroimaging Initiative underwent baseline health assessment, including blood pressure assessment and lumbar puncture for determination of cerebral spinal fluid phosphorylated tau (P-tau) and β-amyloid 1-42. Participants have been followed up longitudinally since 2005. The last date of examination was October 15, 2013. Clinical follow-up between 6 and 96 months tracked progression to dementia.

MAIN OUTCOMES AND MEASURES

Regression and analysis of covariance analyses investigated relationships between pulse pressure and distinct cerebral spinal fluid biomarker profiles. Very old participants (80 years or older) were compared with younger participants (55-79 years of age) on clinical measures and pulse pressure × age group interactions were investigated. Survival analysis examined the effect of baseline pulse pressure on progression to dementia. Covariates were age, sex, apolipoprotein E genotype, body mass index, vascular risk factors, and antihypertensive medication use.

RESULTS

Individuals with a P-tau-positive biomarker profile exhibited mean (SD) elevated pulse pressure regardless of age (62.0 [15.6] mm Hg for a P-tau-positive biomarker vs 57.4 [14.0] mm Hg for P-tau-negative biomarker; P = .04). In very old participants, a further increase in pulse pressure was observed in those exhibiting both P-tau elevation and β-amyloid 1-42 reduction vs either biomarkers alone (69.7 [16.0] mm Hg for both positive biomarkers vs 63.18 [13.0] mm Hg for P-tau alone vs 60.1 [16.4] mm Hg for β-amyloid 1-42 alone vs 56.6 [14.5] mm Hg for negative biomarkers; P = .003). Those with higher baseline pulse pressure progressed to dementia more rapidly (95% CI, 1.000-1.048; P = .05; hazard ratio = 1.024). Systolic pressure exhibited similar relationships with Alzheimer disease biomarkers and progression to dementia in the very old subgroup (P < .05) but showed no associations in the young old subgroup (P > .10). Diastolic pressure was reduced in young old participants with isolated phosphorylated tau elevation (P = .04).

CONCLUSIONS AND RELEVANCE

Pulse pressure, an index of vascular aging, was associated with neurodegenerative change prior to the onset of dementia across a broad age range. Among those with more advanced age, higher pulse pressure was also associated with cerebral amyloidosis in the presence of neurodegeneration and more rapid progression to dementia. Diastolic contributions to these biomarker associations were limited to young old participants whereas systolic contributions were found only in very old participants.