High-Normal Blood Pressure Is Associated With Poor Cognitive Performance

The Association Between Cardiovascular Disease and Dementia: A Review of Trends in Epidemiology, Risk Factors, Pathophysiologic Mechanisms, and Clinical Implications

With increases in life expectancy and the size of the aging population, cognitive decline and neurodegenerative pathologies are expected to increase in the next few decades. Age-related increases in risk for dementia and cardiovascular disease have been researched widely. Epidemiology trends reveal a predicted increase of neurodegenerative disease to more than 65 million by 2030 in the United States. There are several risk factors for the development of cardiovascular disease that have been widely studied for their impact on dementia; such as: diabetes, hypertension, and hyperlipidemia. Several pathophysiologic mechanisms exist by which cardiovascular disease could impact dementia including cerebral hypoperfusion, reactive oxidative species, and increased cleavage of amyloid precursor protein into amyloid beta plaques and accumulation of neurofibrillary tangles. Emerging evidence also suggests that treatment of cardiovascular disease risk factors could reduce the risk of dementia development. In this review, we seek to examine the relationship between cardiovascular disease and dementia by examining epidemiologic trends, common risk factors, pathophysiologic mechanisms and implications for clinical management.

Cerebral blood flow regulation and cognitive performance in hypertension

We examined the relation between transcranial Doppler (TCD) markers of cerebral blood flow regulation and cognitive performance in hypertension (HT) patients to evaluate the predictive value of these markers for cognitive decline. We assessed dynamic cerebral autoregulation (dCA), vasoreactivity to carbon dioxide, and neurovascular coupling (NVC) in the middle (MCA) and posterior (PCA) cerebral arteries of 52 patients. Neuropsychological evaluation included the Montreal Cognitive Assessment and tests covering attention, executive function, processing speed, and memory. Notably, reduced rate time in the PCA significantly predicted better processing speed (p = 0.003). Furthermore, reduced overshoot systolic cerebral blood velocity in the PCA and reduced phase in the VLF range in the MCA (p = 0.021 and p = 0.017, respectively) significantly predicted better memory. Intriguingly, enhanced dCA in the MCA predicted poorer memory performance, while reduced NVC in the PCA predicted both superior processing speed and memory performance. These findings suggest that HT-induced changes in cerebral hemodynamics impact cognitive performance. Further research should verify these observations and elucidate whether these changes represent adaptive responses or neurovascular inefficiency. TCD markers might provide insights into HT-related cognitive decline.

A pathway linking pulse pressure to dementia in adults with Down syndrome

Adults with Down syndrome are less likely to have hypertension than neurotypical adults. However, whether blood pressure measures are associated with brain health and clinical outcomes in this population has not been studied in detail. Here, we assessed whether pulse pressure is associated with markers of cerebrovascular disease and is linked to a diagnosis of dementia in adults with Down syndrome via structural imaging markers of cerebrovascular disease and atrophy. The study included participants with Down syndrome from the Alzheimer's Disease - Down Syndrome study (n = 195, age = 50.6 ± 7.2 years, 44% women, 18% diagnosed with dementia). Higher pulse pressure was associated with greater global, parietal and occipital white matter hyperintensity volume but not with enlarged perivascular spaces, microbleeds or infarcts. Using a structural equation model, we found that pulse pressure was associated with greater white matter hyperintensity volume, which in turn was related to increased neurodegeneration, and subsequent dementia diagnosis. Pulse pressure is an important determinant of brain health and clinical outcomes in individuals with Down syndrome despite the low likelihood of frank hypertension.

Pathways linking pulse pressure to dementia in adults with Down syndrome

Individuals with Down syndrome (DS) are less likely to have hypertension than neurotypical adults. However, whether blood pressure measures are associated with brain health and clinical outcomes in this population has not been studied in detail. Here, we assessed whether pulse pressure is associated with markers of cerebrovascular disease, entorhinal cortical atrophy, and diagnosis of dementia in adults with DS. Participants with DS from the Biomarkers of Alzheimer's Disease in Adults with Down Syndrome study (ADDS; n=195, age=50.6±7.2 years, 44% women, 18% diagnosed with dementia) were included. Higher pulse pressure was associated with greater global, parietal, and occipital WMH volume. Pulse pressure was not related to enlarged PVS, microbleeds, infarcts, entorhinal cortical thickness, or dementia diagnosis. However, in a serial mediation model, we found that pulse pressure was indirectly related to dementia diagnosis through parieto-occipital WMH and, subsequently through entorhinal cortical thickness. Higher pulse pressure may be a risk factor for dementia in people with DS by promoting cerebrovascular disease, which in turn affects neurodegeneration. Pulse pressure is an important determinant of brain health and clinical outcomes in individuals with Down syndrome despite the low likelihood of frank hypertension.

Systolic blood pressure at age 40 and cognitive function 25 years later: the Akershus Cardiac Examination (ACE) 1950 Study

OBJECTIVES

Hypertension in midlife is a risk factor for cognitive impairment. Still, the ideal midlife blood pressure (BP) remains unknown. We examined associations between different systolic blood pressure (SBP) levels at the age of 40-43 years and change in SBP over a 25-year period with cognitive function at age 62-65 years.

METHODS

We included 2424 individuals born in 1950 who had participated both in the Age 40 Program (1990-1993) and the Akershus Cardiac Examination (ACE) 1950 Study (2012-2015). The exposure was SBP at age 40-43 years and the outcome was cognitive function at age 62-65 years, assessed with Montreal Cognitive Assessment, Delayed recall trial from the Consortium to Establish a Registry for Alzheimer's Disease Word List Memory Task, and Trail Making Test part B (TMT B).

RESULTS

Participants were 40.1 ± 0.3 years old with mean SPB 128 ± 13 mmHg at the Age 40 Program, and 63.9 ± 0.6 years old with mean SPB 138 ± 18 at the ACE 1950 Study. Adjusted linear regressions showed no associations between SBP and subsequent cognitive function. In logistic regressions, individuals with SBP ≥140 mmHg, compared to individuals with SBP <120 mmHg (odds ratio 2.29, 95% confidence interval 1.28-4.10, P-value 0.005) had increased risk of an abnormal TMT B-score. Change in SBP during the 25-year follow-up was not associated with cognitive function.

CONCLUSIONS

SBP ≥140 mmHg at age 40-43 was associated with reduced capacity on TMT B, a domain specific cognitive test sensitive to vascular impairment. No other associations were found between SBP, or change in SBP, and cognitive function.

The Effects of Cardiovascular Risk Factors on Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Performance in Cognitively Healthy Older Adults

OBJECTIVE

The current study investigated the differential impact cardiovascular risk factors (CVRFs) on Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) performance in a large, cognitively healthy, older adult sample across 4 years.

METHOD

Participants were 486 individuals recruited through a longitudinal aging research study in the southeastern United States. Participants were 69.3% female, an average of 69.96 years old (SD = 6.58), 16.32 years of education (SD = 2.27), and Mini-Mental Status Exam score of 29.12 (SD = 1.16). Participants completed the RBANS at baseline and yearly thereafter, as well as the Uniform Data Set demographic and health questionnaires and the Geriatric Depression Scale.

RESULTS

Multilevel modeling was conducted using standardized RBANS index scores. Overall, across indices, performance generally improved across time consistent with practice effects from repeated testing. Some CVRFs were associated with worse performance over time. For example, individuals with hypertension performed more poorly on immediate memory over time (t = -2.06, p < .05). Other CVRFs (e.g., BMI) were not associated with baseline performance or performance over time. (p > .05).

CONCLUSIONS

CVRFs differentially affect RBANS performance over time. These results extend previous cross-sectional findings regarding the impact of different cardiovascular health risks to a large, cognitively healthy, longitudinal sample.

Effects of Blood Pressure on Cognitive Performance in Aging: A Systematic Review

INTRODUCTION

Cognitive functions play a crucial role in daily functioning. Unfortunately, some cognitive abilities decline in the process of healthy aging. An increasing body of evidence has highlighted the role of lifestyle habits and cardiovascular diseases, such as high blood pressure, in increasing the risk of cognitive decline. Surprisingly, although hypertension is a modifiable risk factor for cerebrovascular damage, the role of hypertension on cognitive impairment development is not still clear. Several key questions remain unresolved, and there are many inconsistent results in studies considering this topic. This review is aimed to systematically analyze the results found by the studies that investigated whether high blood pressure, in both hypertensive and healthy people, is related to cognitive performance. Furthermore, it points to evaluate the role of age in this relationship. Method: The review process was conducted according to the PRISMA statement. Restrictions were made, selecting the studies in English and published in peer-review journals, including at least one cognitive measure and blood pressure measurement. Studies that included participants with medical conditions, dementia, psychiatric disorders, strokes, and brain injury were excluded. Cross-sectional and longitudinal studies were analyzed separately. Finally, blood pressure measured at young life (18-39 years), midlife (age 40-64 years), elderly (65-74 years), and old age (≥75 years) were considered. Results: The review allows 68 studies to be selected, which include 154,935 participants. The results provided evidence of an adverse effect of exposure to high blood pressure on cognitive performance. High blood pressure in midlife was linked with poorer cognitive functioning; this evidence was found in cross-sectional and longitudinal studies. However, this association declines with increasing age and tends to become inconsistent. In older people, the relationship between blood pressure and cognitive performance is non-linear, highlighting a beneficial effect of high blood pressure on cognition. Conclusions: Despite some limitations, this review showed that cardiovascular and neuro-cognitive systems do not operate in isolation, but they are related. Blood pressure can be considered an early biomarker of cognitive impairment, and the necessity of early blood pressure measurement and control was underlined.

Cardiovascular risk factors and APOE-ε4 status affect memory functioning in aging via changes to temporal stem diffusion

Prior research investigating associations between hypertension, obesity, and apolipoprotein (APOE) genotype status with memory performance among older adults has yielded inconsistent results. This may reflect, in part, a lack of first accounting for the effects these variables have on structural brain changes, that in turn contribute to age-related memory impairment. The current study sought to clarify the relationships between these factors via path modeling. We hypothesized that higher body mass index (BMI), hypertension, and being an APOE-ε4 allele carrier would predict poorer memory scores, with much of these effects accounted for by indirect effects operating via differences in the integrity of temporal stem white matter. Participants included 125 healthy older adults who underwent neuropsychological assessment and diffusion-weighted MRI scanning. Direct effects were found for hypertension and demographic variables including age, sex, and education. Importantly, indirect effects were found for BMI, hypertension, APOE-ε4 status, age, and sex, where these factors predicted memory scores via their impact on temporal stem diffusion measures. There was also a dual effect of sex, with a direct effect indicating that females had better memory performance overall, and an indirect effect indicating that females with greater temporal stem diffusion had poorer memory performance. Results suggest that changes to the integrity of temporal white matter in aging may underpin reduced memory performance. These results highlight that accounting for variables that not only directly impact cognition, but also for those that indirectly impact cognition via structural brain changes, is crucial for understanding the impact of risk factors on cognition.

Effects of Blood Pressure on Cognitive Performance: A Systematic Review

Background: High blood pressure has been associated with an increased risk of developing cognitive impairment. However, this relationship is unclear. This study aims to systematically review the effects of blood pressure on executive functioning, language, memory, attention and processing speed. Methods: The review process was conducted according to the PRISMA-Statement, using the PubMed, PsycINFO, PsycARTICLES and MEDLINE databases. Restrictions were made by selecting studies, which included one or more cognitive measures and reported blood pressure recordings. Studies that included participants with medical conditions or people diagnosed with dementia, psychiatric disorders, stroke and head trauma were excluded. The review allows selecting fifty studies that included 107,405 participants. The results were reported considering different cognitive domains separately: global cognitive functioning, attention, processing speed, executive functions, memory and visuospatial abilities. Results: Higher blood pressure appears to influence cognitive performance in different domains in the absence of dementia and severe cardiovascular diseases, such as strokes. This relationship seems to be independent of demographic factors (gender and education), medical co-morbidity (diabetes), and psychiatric disorders (depression). Furthermore, it presents different patterns considering ageing. In the elderly, a sort of “cardiovascular paradox” is highlighted, which allows considering higher blood pressure as a protective factor for cognitive functioning. Conclusions: The results underline that higher blood pressure is associated with a higher risk of cognitive decline in people without dementia or stroke. These findings highlight the need to introduce early management of blood pressure, even in the absence of clinical hypertension, to prevent the risk of a decline of cognitive functioning typically associated with ageing.

Age-Related Effect of Antihypertensive Treatment on Cognitive Performance: Is it Better Preventing Dementia in Older Age?

The aim of this study is to investigate the impact of optimal antihypertensive medication on cognitive function. In this 6-month clinical trial, 248 adults were randomly selected by a registry of hypertensive-treated patients (based on a National Hypertension Treatment Program), followed health centers located in Rafsanjan County, Southeast, Iran. Blood pressure was measured 3 times in each appointment pre- and posttreatment. Mini-Mental State Examination was used for cognitive performance evaluation. Paired t test and multiple regression model showed significant correlation between "the differences of systolic and diastolic blood pressure levels" and "cognitive performance in treated patients more than 40 years old." Cognitive performance was not significantly different in patients less than 40 years old post antihypertensive treatment. Cognitive performance scores demonstrated significant increase in responders more than 40 years old post antihypertensive treatment. Antihypertensive treatment in responders with age equal or more than 40 years improves the level of cognitive performance significantly.

Emotional hyper-reactivity and cardiometabolic risk in remitted bipolar patients: a machine learning approach

OBJECTIVE

Remitted bipolar disorder (BD) patients frequently present with chronic mood instability and emotional hyper-reactivity, associated with poor psychosocial functioning and low-grade inflammation. We investigated emotional hyper-reactivity as a dimension for characterization of remitted BD patients, and clinical and biological factors for identifying those with and without emotional hyper-reactivity.

METHOD

A total of 635 adult remitted BD patients, evaluated in the French Network of Bipolar Expert Centers from 2010-2015, were assessed for emotional reactivity using the Multidimensional Assessment of Thymic States. Machine learning algorithms were used on clinical and biological variables to enhance characterization of patients.

RESULTS

After adjustment, patients with emotional hyper-reactivity (n = 306) had significantly higher levels of systolic and diastolic blood pressure (P < 1.0 × 10^-8 ), high-sensitivity C-reactive protein (P < 1.0 × 10^-8 ), fasting glucose (P < 2.23 × 10^-6 ), glycated hemoglobin (P = 0.0008) and suicide attempts (P = 1.4 × 10^-8 ). Using models of combined clinical and biological factors for distinguishing BD patients with and without emotional hyper-reactivity, the strongest predictors were: systolic and diastolic blood pressure, fasting glucose, C-reactive protein and number of suicide attempts. This predictive model identified patients with emotional hyper-reactivity with 84.9% accuracy.

CONCLUSION

The assessment of emotional hyper-reactivity in remitted BD patients is clinically relevant, particularly for identifying those at higher risk of cardiometabolic dysfunction, chronic inflammation, and suicide.

Sex and Age Differences in the Association of Blood Pressure and Hypertension with Cognitive Function in the Elderly: The Rancho Bernardo Study

OBJECTIVES

This study examines sex and age differences in associations of systolic and diastolic blood pressure (SBP, DBP), pulse pressure and hypertension with cognitive function in a community-dwelling population.

DESIGN

Cross-sectional study.

SETTING

Research clinic visit in 1988-91.

PARTICIPANTS

Participants were 693 men and 1022 women aged 50-97 Measurements: Blood pressure was measured and 12 cognitive function tests were administered.

RESULTS

Average age was 73.8±9.9 in men and 73.2±9.3 in women; 62.6% of men and 63.4% of women were hypertensive (SBP≥140 mmHg, DBP≥90 mmHg, or antihypertensive medication use). Each 5-unit increment in SBP, DBP, or pulse pressure and categorical hypertension was associated with significantly increased odds of poor verbal fluency performance in men and poor Trails B performance in women, with strongest associations for hypertension (OR=1.97, CI:1.01,3.85 in men; OR=1.51, CI:1.01,2.26 in women). After age stratification, associations remained statistically significant in younger (<80 years ) but not older (≥80 years) participants.

CONCLUSION

Blood pressure as a continuous or categorical variable was associated with poor performance on cognitive function tests, but domains varied by sex and associations were found only in those younger than 80 years. The absent associations in those aged 80 years and older could support the hypothesis that increased blood flow is required to maintain cerebral perfusion with advancing age, or could reflect a survivor effect.

Blood Pressure and Hispanic/Latino Cognitive Function: Hispanic Community Health Study/Study of Latinos Results

BACKGROUND

Hispanics/Latinos are at increased risk for cardiovascular disease and cognitive decline and dementias. High blood pressure (BP) has been implicated in both stroke and dementias. Associations between BP and cognition among diverse Latinos are still unpublished.

OBJECTIVE

We examined associations between cognition and four BP based measures among diverse Hispanics/Latinos. We hypothesized that higher BP, particularly systolic pressure, and increased arterial stiffness (i.e., pulse pressure), would be associated with lower cognitive function.

METHODS

We used baseline (2008-2011) Hispanic Community Health Study/Study of Latinos (HCHS/SOL; n = 9,019; ages 45-74 years) data to examine cognition in relation to BP measures.

RESULTS

In age, sex, and education adjusted models, systolic, pulse, and mean arterial pressure were consistently negatively associated with executive function, psychomotor speed and sustained attention, verbal episodic learning and memory, speech fluency, and mental status measures. These associations were attenuated but remained statistically significant in fully adjusted models.

CONCLUSION

Among middle-aged and older diverse Hispanics/Latinos, we found modest but consistent associations between indicators of arterial stiffness, and compromised blood flow and lower cognitive function. Clinical management and public health interventions to raise awareness and enhance BP management beginning in midlife could reduce disparities and improve population health by reducing cognitive decline burdens.

Compensatory functional reorganization may precede hypertension-related brain damage and cognitive decline: a functional magnetic resonance imaging study

Supplemental Digital Content is available in the text

Objectives:

Our study aimed at exploring structural and functional differences in the brain during higher cognitive processing between middle-aged hypertensive patients and controls matched for sex, age and years of education.

Methods:

Two groups of 20 patients took part in MRI examinations. This article reports the results of functional MRI during a Stroop color interference task and structural evaluations based on a modified Fazekas scale.

Results:

No intergroup differences were found in regards to the severity of white matter lesions (Mann–Whitney U test = 150.5, P > 0.1), nor from the task performance in the scanner (t₍₃₅₎ = 0.2, P > 0.1). However, brain activation patterns between patients and controls varied. Hypertensive patients involved significantly more cerebral areas during the processing, regardless of the task difficulty. Differences were found in 26 diverse regions of both primary and associative cortices (with a peak voxel located in the cuneus, Z = 6.94, P < 0.05 family-wise error corrected at voxel level).

Conclusion:

Our findings provide an insight into the brain mechanisms related to essential hypertension and suggest a functional reorganization (neuroplasticity) early in the course of the disease.

Visit-to-Visit Blood Pressure Variability in Young Adulthood and Hippocampal Volume and Integrity at Middle Age: The CARDIA Study (Coronary Artery Risk Development in Young Adults)

The aims of this study are to assess the relationships of visit-to-visit blood pressure (BP) variability in young adulthood to hippocampal volume and integrity at middle age. We used data over 8 examinations spanning 25 years collected in the CARDIA study (Coronary Artery Risk Development in Young Adults) of black and white adults (age, 18-30 years) started in 1985 to 1986. Visit-to-visit BP variability was defined as by SDBP and average real variability (ARVBP, defined as the absolute differences of BP between successive BP measurements). Hippocampal tissue volume standardized by intracranial volume (%) and integrity assessed by fractional anisotropy were measured by 3-Tesla magnetic resonance imaging at the year-25 examination (n=545; mean age, 51 years; 54% women and 34% African Americans). Mean systolic BP (SBP)/diastolic BP levels were 110/69 mm Hg at year 0 (baseline), 117/73 mm Hg at year 25, and ARVSBP and SDSBP were 7.7 and 7.9 mm Hg, respectively. In multivariable-adjusted linear models, higher ARVSBP was associated with lower hippocampal volume (unstandardized regression coefficient [standard error] with 1-SD higher ARVSBP: -0.006 [0.003]), and higher SDSBP with lower hippocampal fractional anisotropy (-0.02 [0.01]; all P<0.05), independent of cumulative exposure to SBP during follow-up. Conversely, cumulative exposure to SBP and diastolic BP was not associated with hippocampal volume. There was no interaction by sex or race between ARVSBP or SDSBP with hippocampal volume or integrity. In conclusion, visit-to-visit BP variability during young adulthood may be useful in assessing the potential risk for reductions in hippocampal volume and integrity in midlife.

Association of Arterial Stiffness and Central Pressure With Cognitive Function in Incident Hemodialysis Patients: The PACE Study

Introduction

Cognitive impairment commonly occurs in hemodialysis patients, with vascular disease potentially implicated in its pathogenesis. However, the relationship of detailed vascular assessment with cognitive function in patients new to hemodialysis has not been demonstrated.

Methods

In a prospective study of incident hemodialysis participants enrolled in the Predictors of Arrhythmic and Cardiovascular Risk in ESRD (PACE) study, we determined aortic stiffness by pulse-wave velocity (PWV), systemic arterial stiffness by the augmentation index (AIx) and central pulse pressure (cPP), and examined their associations with cognitive processing speed, executive function, and global cognitive impairment measured by the Trail making test A (TMTA), Trail making test B (TMTB), and the modified Mini-Mental State Exam (3MS).

Results

Mean baseline age was 55 ± 13 years, 58% were male, 72% were African American, 35% had coronary artery disease, 55% had diabetes, and 10% had cognitive impairment. At baseline, higher PWV and cPP were associated with a longer TMTA, and a higher PWV was associated with a longer TMTB, but the associations were attenuated after multivariable adjustment. At 1 year, PWV was not independently associated with TMTA, TMTB, or 3MS. However, unadjusted and adjusted analyses revealed every 10% increase in AIx and 10 mm Hg increase in cPP were associated with longer TMTB (time difference_AIx: 0.14; 95% confidence interval [CI]: 0.02−0.25 log-seconds; time difference_cPP: 0.11; 95% CI: 0.05−0.17 log-seconds) and global cognitive impairment (odds ratio [OR]_AIx: 10.23; 95% CI: 1.77−59.00; OR_cPP: 2.88; 95% CI: 1.48−5.59).

Discussion

Higher AIx and cPP, which are indicative of abnormal wave reflections in distal vessels, are associated with, and might contribute to, declining cognitive function in patients starting hemodialysis.

Therapeutic potential of systemic brain rejuvenation strategies for neurodegenerative disease

Neurodegenerative diseases are a devastating group of conditions that cause progressive loss of neuronal integrity, affecting cognitive and motor functioning in an ever-increasing number of older individuals. Attempts to slow neurodegenerative disease advancement have met with little success in the clinic; however, a new therapeutic approach may stem from classic interventions, such as caloric restriction, exercise, and parabiosis. For decades, researchers have reported that these systemic-level manipulations can promote major functional changes that extend organismal lifespan and healthspan. Only recently, however, have the functional effects of these interventions on the brain begun to be appreciated at a molecular and cellular level. The potential to counteract the effects of aging in the brain, in effect rejuvenating the aged brain, could offer broad therapeutic potential to combat dementia-related neurodegenerative disease in the elderly. In particular, results from heterochronic parabiosis and young plasma administration studies indicate that pro-aging and rejuvenating factors exist in the circulation that can independently promote or reverse age-related phenotypes. The recent demonstration that human umbilical cord blood similarly functions to rejuvenate the aged brain further advances this work to clinical translation. In this review, we focus on these blood-based rejuvenation strategies and their capacity to delay age-related molecular and functional decline in the aging brain. We discuss new findings that extend the beneficial effects of young blood to neurodegenerative disease models. Lastly, we explore the translational potential of blood-based interventions, highlighting current clinical trials aimed at addressing therapeutic applications for the treatment of dementia-related neurodegenerative disease in humans.

"Do it-yourself": Home blood pressure as a predictor of traditional and everyday cognition in older adults

BACKGROUND

Hypertension guidelines recommend home blood pressure (HBP) monitoring in adjunct to office blood pressure (OBP) for its greater reproducibility and prognostic utility in the prevention of cardiovascular outcomes, especially stroke. To date, the relationship between HBP and cognitive function remains unexplored.

METHODS

We examined HBP as a cognitive predictor in a multi-ethnic group of community-dwelling adults aged 60 and over (N = 133) using neuropsychological measures and analyzed the data using multiple regression analyses. We also employed "everyday cognition" measures that have been found to have higher prognostic utility for real-world functioning than traditional cognitive tasks.

RESULTS

Good to perfect HBP monitoring compliance over seven days was achieved by 88.7% of the participants with superior reliability (ICC≥.96) to office readings. Higher home systolic BP and pulse pressure predicted worse processing speed, executive function, and everyday cognitive function, whereas lower home diastolic BP predicted worse everyday cognition. Office readings were similarly associated with everyday cognitive function but with no other cognitive measures.

CONCLUSION

Our findings are the first to validate HBP as a predictor of neuropsychological function in older adults beyond cognitive screening. Differential relationships among blood pressure variables and specific cognitive domains were observed. With proper standardization and training, we demonstrated that HBP can be obtained in a multi-ethnic community-dwelling older adult cohort. Our findings emphasize the importance of employing blood pressure and cognitive measures that are adequately sensitive to detect vascular-related cognitive impairment in a relatively healthy population. Implications regarding proper HBP measurement for hypertension management, cognitive health, and everyday function are discussed.

Administration of bovine casein-derived peptide prevents cognitive decline in Alzheimer disease model mice

There is a growing interest in identifying natural food ingredients that may serve to prevent dementia such as that due to Alzheimer disease (AD). Peptides derived from food proteins have been demonstrated to have various physiological activities such as a hypotensive action. Recent findings have indicated possible associations of hypertension with AD progression, and suggest that angiotensin converting enzyme (ACE) inhibitors with potential to pass through the blood brain barrier (BBB) may reduce the risk of AD. In this study, we investigated the effect of milk peptide (CH-3) on cognitive function in AD model mice. CH-3 contains a tripeptide (methionine-lysine-proline, MKP) that has been found to have a strong ACE inhibitory effect and the potential to pass through the BBB. Adult male ddY mice were used in this study, and an animal model of AD was induced by intracerebroventricular (ICV) injection of Aβ1-42. CH-3 (250 mg/kg/day) or MKP (0.5 mg/kg/day) was orally administered every day starting 2 days before ICV injection. At 3 weeks after ICV injection, cognitive function was evaluated by the Morris water maze test. Brain samples were obtained after behavioral testing, and expression of inflammatory cytokines and NADPH oxidase subunits was measured by real-time quantitative RT-PCR. ICV injection of Aβ1-42 significantly impaired cognitive function compared with that in PBS-injected mice. Daily administration of CH-3 markedly attenuated this Aβ1-42-induced cognitive decline. Aβ1-42 injection significantly enhanced the expression of tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS) and p22phox in the mouse hippocampus compared with PBS injection, and showed a tendency to increase the expression of monocyte chemoattractant protein-1 (MCP-1), p47phox and gp91phox, whereas CH-3 treatment markedly reduced Aβ1-42-induced TNF-α, MCP-1, iNOS, p47phox and gp91phox expression. Finally, administration of MKP also attenuated Aβ1-42-induced cognitive impairment with an increase in cerebral blood flow. The present study demonstrated that repeated oral administration of CH-3 to AD model mice not only improved cognitive function but also suppressed the expression of inflammatory cytokines and production of oxidative stress, and suggests its therapeutic potential for preventing cognitive impairment in AD.

Effect size for the main cognitive function determinants in a large cross-sectional study

BACKGROUND AND PURPOSE

The aim of our study was to examine the effect sizes of different cognitive function determinants in middle and early old age.

METHODS

Cognitive functions were assessed in 11 711 volunteers (45 to 75 years old), included in the French CONSTANCES cohort between January 2012 and May 2014, using the free and cued selective reminding test (FCSRT), verbal fluency tasks, digit-symbol substitution test (DSST) and trail making test (TMT), parts A and B. The effect sizes of socio-demographic (age, sex, education), lifestyle (alcohol, tobacco, physical activity), cardiovascular (diabetes, blood pressure) and psychological (depressive symptomatology) variables were computed as omega-squared coefficients (ω² ; part of the variation of a neuropsychological score that is independently explained by a given variable).

RESULTS

These sets of variables explained from R² = 10% (semantic fluency) to R² = 26% (DSST) of the total variance. In all tests, socio-demographic variables accounted for the greatest part of the explained variance. Age explained from ω² = 0.5% (semantic fluency) to ω² = 7.5% (DSST) of the total score variance, gender from ω² = 5.2% (FCSRT) to a negligible part (semantic fluency or TMT) and education from ω² = 7.2% (DSST) to ω² = 1.4% (TMT-A). Behavioral, cardiovascular and psychological variables only slightly influenced the cognitive test results (all ω² < 0.8%, most ω² < 0.1%).

CONCLUSION

Socio-demographic variables (age, gender and education) are the main variables associated with cognitive performance variations between 45 and 75 years of age in the general population.

Blood pressure and neuropsychological test performance in healthy postmenopausal women

PURPOSE

To study the association between blood pressure and neuropsychological test performance in healthy postmenopausal women.

METHODS

Data from 88 healthy postmenopausal women aged 46-73 years, who were not experiencing hot flashes, and who had participated in a prior drug trial, were analyzed to find whether baseline blood pressure was associated with impaired performance on neuropsychological testing done at 3 follow-up visits separated by 4 weeks. Factor analysis was used to reduce the dimensions of neuropsychological test performance. Mixed linear modeling was used to evaluate the association between baseline blood pressure and repeatedly measured neuropsychological test performance at follow-up in a complete case analysis (n=53). In a sensitivity analysis (n=88), multiple-imputation using the Markov Chain Monte Carlo method was used to account for missing data (blood pressure results) for some visits.

RESULTS

The variables recording neuropsychological test performance were reduced to two main factors (Factor 1=selective attention; Factor 2=complex processing). In the complete case analysis, the association between a 20-mmHg increase in diastolic blood pressure and Factor 1 remained statistically significant after adjusting for potential confounders, before adjusting for systolic blood pressure (slope=0.60; 95%CI=0.04,1.16), and after adjusting for systolic blood pressure (slope=0.76; 95%CI=0.06, 1.47). The positive slopes indicated an increase in the time spent performing a given task (i.e., a decrease in neuropsychological test performance). No other significant associations were found between systolic blood pressure and either factor. The results did not materially change after applying the multiple-imputation method.

CONCLUSIONS

An increase in diastolic blood pressure was associated with a decrease in neuropsychological test performance among older healthy postmenopausal women experiencing hot flashes.

Neurocognitive Dysfunction in Children, Adolescents, and Young Adults With CKD

BACKGROUND

Neurocognitive dysfunction is a known complication in children with chronic kidney disease (CKD). However, less is known about putative mechanisms or modifiable risk factors. The objective of this study was to characterize and determine risk factors for cognitive dysfunction in children, adolescents, and young adults with CKD compared with controls.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

The Neurocognitive Assessment and Magnetic Resonance Imaging Analysis of Children and Young Adults With Chronic Kidney Disease (NiCK) Study included 90 individuals aged 8 to 25 years with CKD compared with 70 controls.

PREDICTORS

CKD versus control, estimated glomerular filtration rate (eGFR), ambulatory blood pressure.

OUTCOMES

Performance on neurocognitive assessment with relevant tests grouped into 11 domains defined a priori by expert opinion. Results of tests were converted to age-normalized z scores.

MEASUREMENTS

Each neurocognitive domain was analyzed through linear regression, adjusting for eGFR and demographic and clinical variables. For domains defined by multiple tests, the median z score of tests in that domain was used.

RESULTS

We found significantly poorer performance in multiple areas of neurocognitive function among individuals with CKD compared with controls. Particular deficits were seen in domains related to attention, memory, and inhibitory control. Adjusted for demographic and clinical factors, we found lower performance in multiple domains with decreasing eGFRs (attention: β=0.053, P=0.02; visual spatial: β=0.062, P=0.02; and visual working memory: β=0.069, P=0.04). Increased diastolic load and decreased diastolic nocturnal dipping on ambulatory blood pressure monitoring were independently associated with impairments in neurocognitive performance.

LIMITATIONS

Unable to assess changes in neurocognitive function over time, and neurocognitive tests were grouped into predetermined neurocognitive domains.

CONCLUSIONS

Lower eGFR in children, adolescents, and young adults is associated with poorer neurocognitive performance, particularly in areas of attention, memory, and inhibitory control. Hypertension identified on ambulatory blood pressure monitoring may be an important risk factor, illustrating that neurocognitive function is an area of target-organ damage in CKD.

Association between intraoperative blood pressure and postoperative delirium in elderly hip fracture patients

Background

One possible area of intervention to prevent postoperative delirium (PD) is intraoperative blood pressure management. However, the relationship between intraoperative blood pressure and PD is unclear. A secondary analysis of a RCT study examining the PD risk over the range of absolute intraoperative mean arterial blood pressure (MAP) readings and the corresponding relative changes from preoperative baseline level was performed to determine the role of MAP on PD.

Methods

Nonparametric locally weighted quadratic polynomial smoothing (LOESS) regression explored the pattern of PD risk at postoperative day 2 as a function of mean surgery MAP (msMAP) and percent change of msMAP from baseline in 103 elderly hip fracture patients. Segment-linear logistic regression models were then constructed to determine the odds ratios (OR) of PD over the observed range of these msMAP measures, adjusting for potential confounds.

Results

Twenty-three patients (22%) developed PD on day 2. LOESS regression revealed a j-shaped association between absolute levels of msMAP and PD risk. When msMAP was ≥80 mmHg, higher msMAP imparted greater PD risk (OR = 2.28 per 10 mmHg msMAP increase; 95% CI: 1.11–4.70), while higher msMAP was associated with lower PD risk (OR = 0.19 per 10 mmHg increase; CI: 0.05–0.76) if msMAP was <80 mmHg. There was no statistically significant relationship between PD risk and average percent change from baseline in these msMAP measures.

Conclusion

In elderly hip fracture patients, both very high and very low levels of msMAP were associated with significantly increased risk of PD.

Blood pressure interacts with APOE ε4 to predict memory performance in a midlife sample

OBJECTIVE

Elevated blood pressure and the Apolipoprotein ε4 allele (APOE ε4) are independent risk factors for Alzheimer's disease. We sought to determine whether the combined presence of the APOE ε4 allele and elevated blood pressure is associated with lower cognitive performance in cognitively healthy middle-aged adults.

METHODS

A total of 975 participants aged 30-54 (mean age = 44.47) were genotyped for APOE. Cardiometabolic risk factors including blood pressure, lipids, and glucose were assessed and cognitive function was measured using the Trail Making Test and the Visual Reproduction and Logical Memory subtests from the Wechsler Memory Scale.

RESULTS

Multivariable regression analysis showed that the association between APOE ε4 and episodic memory performance varied as a function of systolic blood pressure (SBP), such that elevated SBP was predictive of poorer episodic memory performance only in APOE ε4 carriers (β = -.092; t = -2.614; p = .009). Notably, this association was apparent at prehypertensive levels (≥130 mmHg), even after adjusting for physical activity, depression, smoking, and other cardiometabolic risk factors.

CONCLUSIONS

The joint presence of APOE ε4 and elevated SBP, even at prehypertensive levels, is associated with lower cognitive performance in healthy, middle-aged adults. Results of this study suggest that the combination of APOE ε4 and elevated SBP may synergistically compromise memory function well before the appearance of clinically significant impairments. Interventions targeting blood pressure control in APOE ε4 carriers during midlife should be studied as a possible means to reduce the risk of cognitive decline in genetically susceptible samples.

Mildly elevated blood pressure is a marker for better health status in Polish centenarians

The number of centenarians is projected to rise rapidly. However, knowledge of evidence-based health care in this group is still poor. Hypertension is the most common condition that leads to multiple organ complications, disability, and premature death. No guidelines for the management of high blood pressure (BP) in centenarians are available. We have performed a cross-sectional study to characterize clinical and functional state of Polish centenarians, with a special focus on BP. The study comprised 86 consecutive 100.9 ± 1.2 years old (mean ± SD) subjects (70 women and 16 men). The assessment included structured interview, physical examination, geriatric functional assessment, resting electrocardiography, and blood and urine sampling. The subjects were followed-up on the phone. Subjects who survived 180 days (83 %) as compared to non-survivors had higher systolic BP (SBP), diastolic BP (DPB), mean arterial pressure (MAP), pulse pressure (PP), higher mini-mental state examination, Barthel Index of Activities of Daily Living and Lawton Instrumental Activities of Daily Living Scale scores, higher serum albumin and calcium levels, and total iron-binding capacity, while lower serum creatinine, cystatin C, folate, and C-reactive protein levels. SBP ≥140 mm Hg, DBP ≥90 mm Hg, MAP ≥100 mm Hg, and PP ≥40 mm Hg were associated with higher 180-day survival probability. Results suggest that mildly elevated blood pressure is a marker for better health status in Polish centenarians.

The KEEPS-Cognitive and Affective Study: baseline associations between vascular risk factors and cognition

Midlife vascular risk factors influence later cognitive decline and Alzheimer's disease (AD). The decrease in serum estradiol levels during menopause has been associated with cognitive impairment and increased vascular risk, such as high blood pressure (BP), which independently contributes to cognitive dysfunction and AD. We describe the extent to which vascular risk factors relate to cognition in healthy, middle-aged, recently postmenopausal women enrolled in the Kronos Early Estrogen Prevention Cognitive and Affective Study (KEEPS-Cog) at baseline. KEEPS-Cog is a double-blind, randomized, placebo-controlled, parallel group, clinical trial, investigating the efficacy of low-dose, transdermal 17β-estradiol and oral conjugated equine estrogen on cognition. All results are cross-sectional and represent baseline data only. Analyses confirm that the KEEPS-Cog cohort (n = 571) was middle aged (mean 52.7 years, range 42-59 years), healthy, and free of cognitive dysfunction. Higher systolic BP was weakly related to poorer performance in auditory working memory and attention (p = 0.004; adjusted for multiple comparisons p = 0.10). This relationship was not associated with endogenous hormone levels, and systolic BP was not related to any other cognitive domain. BP levels may be more sensitive than other vascular risk factors in detecting subtle differences in cognitive task performance in healthy, recently menopausal women. Lower BP early in menopause may affect cognitive domains known to be associated with AD.

A systematic review of type 2 diabetes mellitus and hypertension in imaging studies of cognitive aging: time to establish new norms

The rising prevalence of type 2 diabetes (T2DM) and hypertension in older adults, and the deleterious effect of these conditions on cerebrovascular and brain health, is creating a growing discrepancy between the "typical" cognitive aging trajectory and a "healthy" cognitive aging trajectory. These changing health demographics make T2DM and hypertension important topics of study in their own right, and warrant attention from the perspective of cognitive aging neuroimaging research. Specifically, interpretation of individual or group differences in blood oxygenation level dependent magnetic resonance imaging (BOLD MRI) or positron emission tomography (PET H2O(15)) signals as reflective of differences in neural activation underlying a cognitive operation of interest requires assumptions of intact vascular health amongst the study participants. Without adequate screening, inclusion of individuals with T2DM or hypertension in "healthy" samples may introduce unwanted variability and bias to brain and/or cognitive measures, and increase potential for error. We conducted a systematic review of the cognitive aging neuroimaging literature to document the extent to which researchers account for these conditions. Of the 232 studies selected for review, few explicitly excluded individuals with T2DM (9%) or hypertension (13%). A large portion had exclusion criteria that made it difficult to determine whether T2DM or hypertension were excluded (44 and 37%), and many did not mention any selection criteria related to T2DM or hypertension (34 and 22%). Of all the surveyed studies, only 29% acknowledged or addressed the potential influence of intersubject vascular variability on the measured BOLD or PET signals. To reinforce the notion that individuals with T2DM and hypertension should not be overlooked as a potential source of bias, we also provide an overview of metabolic and vascular changes associated with T2DM and hypertension, as they relate to cerebrovascular and brain health.

Cortical reorganization due to impaired cerebral autoregulation in individuals with occlusive processes of the internal carotid artery

BACKGROUND AND PURPOSE

To study the impact of impaired cerebral autoregulation on cortical neurophysiology, long term potentiation (LTP)-like plasticity, motor learning and brain structure.

METHODS

12 patients with unilateral occlusion or severe stenosis of the internal carotid artery were included. Impairment of cerebral autoregulation was determined by vasomotor reactivity in transcranial Doppler sonography. Corticomotor excitability, cortical silent period and LTP-like plasticity were assessed with transcranial magnetic stimulation, motor learning with a force production task, and brain structure with high-resolution MRI of the brain.

RESULTS

In the affected hemisphere, corticomotor excitability was significantly higher, cortical silent period and LTP-like plasticity significantly lower, compared to the contralateral side. No significant difference emerged for motor learning, cortical thickness and white matter integrity between the hemispheres.

CONCLUSION

Despite decreased LTP-like plasticity in the affected hemisphere, motor learning was comparable between hemispheres, possibly due to gamma-aminobutyric-acid (GABA)B-mediated corticomotor excitability changes within the affected hemisphere. Our results may help to develop interventions to beneficially modulate cortical physiology in the presence of cerebral hypoperfusion.

Impaired cognitive executive dysfunction in adult treated hypertensives with a confirmed diagnosis of poorly controlled blood pressure

BACKGROUND

High blood pressure (BP) poses a major risk for cognitive decline. Aim of the study was to highlight the relationship between cognitive assessment scores and an effective therapeutic BP control.

METHODS

By medical visit and ambulatory BP monitoring (ABPM), we studied 302 treated hypertensives, subdivided according to office/daytime BP values into 120 with good (GC) and 98 poor (PC) BP control, 40 with "white coat hypertension" (WCH) and 44 a "masked-hypertension" phenomenon (MH). Patients underwent neuropsychological assessment to evaluate global cognitive scores at the Mini Mental State Examination (MMSE) and Frontal Assessment Battery (FAB) and attention/executive functions (Delayed Recall, Digit Span Forwards, Digit Span Backwards, Selective Attention, Verbal Fluency, Stroop Test and Clock Drawing). Carotid intima-media thickness (IMT) served as the index of vascular damage.

RESULTS

There were no differences among the groups in terms of gender, age, education, metabolic assessment, clinical history and hypertension treatment. GC presented lower office and ambulatory BP values and IMT. PC performed worse than GC on global executive and attention functions, especially executive functions. In PC, office systolic BP (SBP) was significantly associated to the MMSE and FAB scores and, in particular, to Verbal Fluency, Stroop Errors and Clock Drawing tests. Office diastolic BP (DBP) was associated to Selective attention, nocturnal SBP to Digit Span backwards and Verbal Fluency. Worse cognitive assessment scores were obtained in WCH than GC.

CONCLUSIONS

The findings showed that in adult treated hypertensives, a poor BP control, as both doctor's office and daytime scores, is associated to impaired global cognitive and especially executive/attention functions.

Age- and gender-adjusted normative data for the German version of Rey's Auditory Verbal Learning Test from healthy subjects aged between 50 and 70 years

Rey's Auditory Verbal Learning Test (AVLT) is widely used to evaluate dysfunctional episodic memory. The current study aimed to provide extended age- and gender-specific norms for the German AVLT for individuals older than 50 years. In 690 subjects, a comprehensive medical examination including a structural 3.0-tesla magnetic resonance imaging scan was administered, as well as extensive neuropsychological tests. After controlling for exclusion criteria, 407 subjects were included in the analysis. AVLT performance decreased with age, and women outperformed men. We present age- and gender-specific normative data for the German AVLT from subjects aged between 50 and 70 years.

Physical exercise and cognitive performance in the elderly: current perspectives

In an aging population with increasing incidence of dementia and cognitive impairment, strategies are needed to slow age-related decline and reduce disease-related cognitive impairment in older adults. Physical exercise that targets modifiable risk factors and neuroprotective mechanisms may reduce declines in cognitive performance attributed to the normal aging process and protect against changes related to neurodegenerative diseases such as Alzheimer’s disease and other types of dementia. In this review we summarize the role of exercise in neuroprotection and cognitive performance, and provide information related to implementation of physical exercise programs for older adults. Evidence from both animal and human studies supports the role of physical exercise in modifying metabolic, structural, and functional dimensions of the brain and preserving cognitive performance in older adults. The results of observational studies support a dose-dependent neuroprotective relationship between physical exercise and cognitive performance in older adults. Although some clinical trials of exercise interventions demonstrate positive effects of exercise on cognitive performance, other trials show minimal to no effect. Although further research is needed, physical exercise interventions aimed at improving brain health through neuroprotective mechanisms show promise for preserving cognitive performance. Exercise programs that are structured, individualized, higher intensity, longer duration, and multicomponent show promise for preserving cognitive performance in older adults.

A statistical cerebroarterial atlas derived from 700 MRA datasets

OBJECTIVES

The cerebroarterial system is a complex network of arteries that supply the brain cells with vitally important nutrients and oxygen. The inter-individual differences of the cerebral arteries, especially at a finer level, are still not understood sufficiently. The aim of this work is to present a statistical cerebroarterial atlas that can be used to overcome this problem.

METHODS

Overall, 700 Time-of-Flight (TOF) magnetic resonance angiography (MRA) datasets of healthy subjects were used for atlas generation. Therefore, the cerebral arteries were automatically segmented in each dataset and used for a quantification of the vessel diameters. After this, each TOF MRA dataset as well as the corresponding vessel segmentation and vessel diameter dataset were registered to the MNI brain atlas. Finally, the registered datasets were used to calculate a statistical cerebroarterial atlas that incorporates information about the average TOF intensity, probability for a vessel occurrence and mean vessel diameter for each voxel.

RESULTS

Visual analysis revealed that arteries with a diameter as small as 0.5 mm are well represented in the atlas with quantitative values that are within range of anatomical reference values. Moreover, a highly significant strong positive correlation between the vessel diameter and occurrence probability was found. Furthermore, it was shown that an intensity-based automatic segmentation of cerebral vessels can be considerable improved by incorporating the atlas information leading to results within the range of the inter-observer agreement.

CONCLUSION

The presented cerebroarterial atlas seems useful for improving the understanding about normal variations of cerebral arteries, initialization of cerebrovascular segmentation methods and may even lay the foundation for a reliable quantification of subtle morphological vascular changes.

Characterization of a normal control group: are they healthy?

We examined the health of a control group (18-81years) in our aging study, which is similar to control groups used in other neuroimaging studies. The current study was motivated by our previous results showing that one third of the elder control group had moderate to severe white matter hyperintensities and/or cortical volume loss which correlated with poor performance on memory tasks. Therefore, we predicted that cardiovascular risk factors (e.g., hypertension, high cholesterol) within the control group would account for significant variance on working memory task performance. Fifty-five participants completed 4 verbal and spatial working memory tasks, neuropsychological exams, diffusion tensor imaging (DTI), and blood tests to assess vascular risk. In addition to using a repeated measures ANOVA design, a cluster analysis was applied to the vascular risk measures as a data reduction step to characterize relationships between conjoint risk factors. The cluster groupings were used to predict working memory performance. The results show that higher levels of systolic blood pressure were associated with: 1) poor spatial working memory accuracy; and 2) lower fractional anisotropy (FA) values in multiple brain regions. In contrast, higher levels of total cholesterol corresponded with increased accuracy in verbal working memory. An association between lower FA values and higher cholesterol levels were identified in different brain regions from those associated with systolic blood pressure. The conjoint risk analysis revealed that Risk Cluster Group 3 (the group with the greatest number of risk factors) displayed: 1) the poorest performance on the spatial working memory tasks; 2) the longest reaction times across both spatial and verbal memory tasks; and 3) the lowest FA values across widespread brain regions. Our results confirm that a considerable range of vascular risk factors are present in a typical control group, even in younger individuals, which have robust effects on brain anatomy and function. These results present a new challenge to neuroimaging studies both for defining a cohort from which to characterize 'normative' brain circuitry and for establishing a control group to compare with other clinical populations.

Blood pressure and cognition among older adults: a meta-analysis

Hypertension has adverse effects on cognition, can alter cerebral vasculature integrity, and is associated with the pathogenesis of dementia. Using meta-analysis, we correlated blood pressure to multiple cognitive domains among older adults free of clinical stroke and dementia. We identified 230 studies indexed in PubMed and PsycINFO relating blood pressure and cognition. After applying exclusion criteria, we selected n = 12 articles with n = 4,076 participants (age range 43-91 years). Meta-analysis yielded an association between blood pressure and episodic memory (r = -.18, p < .001) and between blood pressure and global cognition (r = -.07, p < .001). When limiting analyses to studies adjusting for vascular covariates (n = 8, n = 2,141), blood pressure was modestly related to global cognition (r = -.11, p < .001), attention (r = .14, p = .002), and episodic memory (r = -.20, p < .001) with a trend for language (r = -.22, p = .07). Findings underscore the need to manage blood pressure as a key prevention method in minimizing abnormal cognitive aging prior to the onset of clinical dementia.

Sex-specific effects on spatial learning and memory, and sex-independent effects on blood pressure of a <3.3 Mbp rat chromosome 2 QTL region in Dahl salt-sensitive rats

Epidemiological studies have consistently found that hypertension is associated with poor cognitive performance. We hypothesize that a putative causal mechanism underlying this association is due to genetic loci affecting both blood pressure and cognition. Consistent with this notion, we reported several blood pressure (BP) quantitative trait loci (QTLs) that co-localized with navigational performance (Nav)-QTLs influencing spatial learning and memory in Dahl rats. The present study investigates a chromosome 2 region harboring BP-f4 and Nav-8 QTLs. We developed two congenic strains, S.R2A and S.R2B introgressing Dahl R-chromosome 2 segments into Dahl S chromosome 2 region spanning BP-f4 and Nav-8 QTLs. Radiotelemetric blood pressure analysis identified only S.R2A congenic rats with lower systolic blood pressure (females: -26.0 mmHg, P = 0.003; males: -30.9 mmHg, P<1×10(-5)), diastolic blood pressure (females: -21.2 mmHg, P = 0.01; males: -25.7 mmHg, P<1×10(-5)), and mean arterial pressure (females: -23.9 mmHg, P = 0.004; males: -28.0 mmHg, P<1×10(-5)) compared with corresponding Dahl S controls, confirming the presence of BP-f4 QTL on rat chromosome 2. The S.R2B congenic segment did not affect blood pressure. Testing of S.R2A, S.R2B, and Dahl S male rats in the Morris water maze (MWM) task revealed significantly decreased spatial navigation performance in S.R2A male congenic rats when compared with Dahl S male controls (P<0.05). The S.R2B congenic segment did not affect performance of the MWM task in males. The S.R2A female rats did not differ in spatial navigation when compared with Dahl S female controls, indicating that the Nav-8 effect on spatial navigation is male-specific. Our results suggest the existence of a single QTL on chromosome 2 176.6-179.9 Mbp region which affects blood pressure in both males and females and cognition solely in males.

Common exonic missense variants in the C2 domain of the human KIBRA protein modify lipid binding and cognitive performance

The human KIBRA gene has been linked to human cognition through a lead intronic single-nucleotide polymorphism (SNP; rs17070145) that is associated with episodic memory performance and the risk to develop Alzheimer's disease. However, it remains unknown how this relates to the function of the KIBRA protein. Here, we identified two common missense SNPs (rs3822660G/T [M734I], rs3822659T/G [S735A]) in exon 15 of the human KIBRA gene to affect cognitive performance, and to be in almost complete linkage disequilibrium with rs17070145. The identified SNPs encode variants of the KIBRA C2 domain with distinct Ca(2+) dependent binding preferences for monophosphorylated phosphatidylinositols likely due to differences in the dynamics and folding of the lipid-binding pocket. Our results further implicate the KIBRA protein in higher brain function and provide direction to the cellular pathways involved.

A novel dynamic cardiac simulator utilizing pneumatic artificial muscle

With the development of methods and skills of minimally invasive surgeries, equipments for doctors' training and practicing are in high demands. Especially for the cardiovascular surgeries, operators are requested to be familiar with the surgical environment of a beating heart. In this paper, we present a new dynamic cardiac simulator utilizing pneumatic artificial muscle to realize heartbeat. It's an artificial left ventricular of which the inner chamber is made of thermoplastic elastomers (TPE) with an anatomical structure of the real human heart. It is covered by another layer of material forming the artificial muscle which actuates the systole and diastole uniformly and omnidirectionally as the cardiac muscle does. Preliminary experiments were conducted to evaluate the performance of the simulator. The results indicated that the pressure at the terminal of the aorta could be controlled within the range of normal human systolic pressure, which quantitatively validated the new actuating mode of the heart-beating is effective.

[Prevention of vascular dementia. Evidence and practice]

During recent years, increasing knowledge has been obtained from clinical studies about the impact that vascular factors have on cognitive function and dementia. Due to demographic reasons and still insufficient control of all vascular risk factors, dementia and associated problems are of increasing importance and will have impact on economical and social development in most countries. The incidence of cognitive impairment and dementia will increase exponentially. As long as no causal therapy for dementia exists, diagnosis and control of risk factors for dementia will need much more attention. Hypertension is not only the most important risk factor for stroke that often leads to dementia but also for silent brain infarcts, which are also associated with onset of dementia. Uncontrolled hypertension is associated with cognitive impairment and sufficient control of hypertension in middle-aged patients can reduce the risk of dementia in older ages. Nevertheless, treatment of all other risk factors (e.g., diabetes mellitus, hyperlipidemia, atrial fibrillation) is important to reduce the onset of not only vascular but also Alzheimer dementia.

Neurocognitive alterations in hypertensive children and adolescents

Hypertensive adults demonstrate performance deficits on neuropsychological testing compared with scores of normotensive controls. This article reviews emerging preliminary evidence that children with hypertension also manifest neurocognitive differences when compared with normotensive controls. Database and single-center studies suggest that children with hypertension manifest deficits on measures of neurocognition and have an increased prevalence of learning difficulties and that children with hypertension associated with obesity may be at increased risk for depression and anxiety. Studies suggesting blunted cerebrovascular reactivity in children with hypertension are also reviewed.

Cortical plasticity is preserved in nondemented older individuals with severe ischemic small vessel disease

Ischemic small vessel disease (SVD) is a common finding on routine scans in older people, but cognitive sequelae vary considerably. To improve understanding of mechanisms underlying decline or preservation of cognitive function in this condition, we assessed cognition and cortical plasticity in 20 elderly subjects with severe SVD and 20 age-matched controls without SVD, as rated on conventional MRI. Cognitive status was determined with a neuropsychological test battery, cortical plasticity induced with a paired associative stimulation protocol. Microstructural white matter changes were further analyzed for fractional anisotrophy using diffusion tensor imaging. We found that cortical plasticity as well as memory functions were preserved in severe SVD, while executive functions showed trendwise or significant decreases. Within the SVD group, lower white matter integrity in parahippocampal regions and posterior parts of the corpus callosum was associated with larger cortical plasticity, an association not seen for prefrontal white matter tracts. Enhanced cortical plasticity in subjects with lower white matter integrity in memory-relevant areas might thus indicate a compensatory mechanism to counteract memory decline in severe SVD.

Decreased Cognitive/CNS Function in Young Adults at Risk for Hypertension: Effects of Sleep Deprivation

Hypertension has been linked to impaired cognitive/CNS function, and some of these changes may precede development of frank essential hypertension. The stress and fatigue of sleep deprivation may exacerbate these cognitive changes in young adults at risk. We hypothesize that individuals at risk for hypertension will show significant declines in cognitive function during a night of sleep deprivation. Fifty-one young adults were recruited for 28-hour total sleep deprivation studies. Hypertension risk was assessed by mildly elevated resting blood pressure and by family history of hypertension. A series of cognitive memory tasks was given at four test sessions across the sleep deprivation period. Although initially comparable in cognitive performance, persons at risk showed larger declines across the night for several indices of working memory, including code substitution, category, and order recall. These results suggest that cognitive/CNS changes may parallel or precede blood pressure dysregulation in the early stages of hypertension development. The role of CNS changes in the etiology of essential hypertension is discussed.

Association of cognitive function with cardiovascular risk factors in middle age individuals

Objective. To find the association between cognitive function and cardiovascular risk factors and to develop statistic model. Results. Our study demonstrated that cognitive dysfunction is more profound in middle-aged patients with metabolic syndrome (MS) compared to the individuals with single risk factors without MS. Multiple regression analysis defined glucose (β = 0,0114) and systolic blood pressure (SBP) (β = -0,212) to be factors related with MMSE-test results. When glucose level was excluded from the model, the following factors were shown to be significant: SBP (β = -0,202), age (β = -0,093), operative memory (β = -0,169), total cholesterol level (β = -0,065), therapy by calcium antagonist (β = 0,082), obesity (β = 0,06), R = 92 %.

Age-related effects of blood pressure on everyday cognitive function in community-dwelling women

OBJECTIVES

Blood pressure is an indicator of vascular health that has been associated with cognition and quality of life in older age. Few studies have examined blood pressure across everyday cognitive tasks, which may have superior predictive functional utility than traditional cognitive measures. We explored blood pressure as a predictor of everyday problem solving (EPS) performance in middle-aged and older women.

METHOD

Community-dwelling women (age: 51-91) with low-normal blood pressure to mild hypertension underwent traditional and everyday cognitive testing. EPS was determined by the number of safe/effective solutions generated for real-world scenarios.

RESULTS

Analyses revealed that lower systolic blood pressure and pulse pressure were associated with worse EPS ability after controlling for age, education, and traditional cognitive abilities.

DISCUSSION

These results support that blood pressure may be an important predictor of everyday cognitive abilities in older age. Potential implications for real-world functioning are discussed.