Risk factors for vascular dementia: hypotension as a key point

Implication of Hypotension in the Pathogenesis of Cognitive Impairment and Brain Injury in Chronic Liver Disease

The incidence of chronic liver disease is on the rise. One of the primary causes of hospital admissions for patients with cirrhosis is hepatic encephalopathy (HE), a debilitating neurological complication. HE is defined as a reversible syndrome, yet there is growing evidence stating that, under certain conditions, HE is associated with permanent neuronal injury and irreversibility. The pathophysiology of HE primarily implicates a strong role for hyperammonemia, but it is believed other pathogenic factors are involved. The fibrotic scarring of the liver during the progression of chronic liver disease (cirrhosis) consequently leads to increased hepatic resistance and circulatory anomalies characterized by portal hypertension, hyperdynamic circulatory state and systemic hypotension. The possible repercussions of these circulatory anomalies on brain perfusion, including impaired cerebral blood flow (CBF) autoregulation, could be implicated in the development of HE and/or permanent brain injury. Furthermore, hypotensive insults incurring during gastrointestinal bleed, infection, or liver transplantation may also trigger or exacerbate brain dysfunction and cell damage. This review will focus on the role of hypotension in the onset of HE as well as in the occurrence of neuronal cell loss in cirrhosis.

Joint effects of air pollution and neighborhood socioeconomic status on cognitive decline - Mediation by depression, high cholesterol levels, and high blood pressure

Air pollution and neighborhood socioeconomic status (N-SES) are associated with adverse cardiovascular health and neuropsychiatric functioning in older adults. This study examines the degree to which the joint effects of air pollution and N-SES on the cognitive decline are mediated by high cholesterol levels, high blood pressure (HBP), and depression. In the Emory Healthy Aging Study, 14,390 participants aged 50+ years from Metro Atlanta, GA, were assessed for subjective cognitive decline using the cognitive function instrument (CFI). Information on the prior diagnosis of high cholesterol, HBP, and depression was collected through the Health History Questionnaire. Participants' census tracts were assigned 3-year average concentrations of 12 air pollutants and 16 N-SES characteristics. We used the unsupervised clustering algorithm Self-Organizing Maps (SOM) to create 6 exposure clusters based on the joint distribution of air pollution and N-SES in each census tract. Linear regression analysis was used to estimate the effects of the SOM cluster indicator on CFI, adjusting for age, race/ethnicity, education, and neighborhood residential stability. The proportion of the association mediated by high cholesterol levels, HBP, and depression was calculated by comparing the total and direct effects of SOM clusters on CFI. Depression mediated up to 87 % of the association between SOM clusters and CFI. For example, participants living in the high N-SES and high air pollution cluster had CFI scores 0.05 (95 %-CI:0.01,0.09) points higher on average compared to those from the high N-SES and low air pollution cluster; after adjusting for depression, this association was attenuated to 0.01 (95 %-CI:-0.04,0.05). HBP mediated up to 8 % of the association between SOM clusters and CFI and high cholesterol up to 5 %. Air pollution and N-SES associated cognitive decline was partially mediated by depression. Only a small portion (<10 %) of the association was mediated by HBP and high cholesterol.

Association between Blood Pressure and Post-Stroke Cognitive Impairment: A Meta-Analysis

Background

Post-stroke cognitive impairment (PSCI) represents a serious post-stroke complication with poor cognitive consequences. A vascular consequence after a stroke is that the occurrence and progression of PSCI may be closely related to blood pressure (BP). Thus, we systematically reviewed and performed a meta-analysis of the literature to examine the correlations between BP and PSCI.

Methods

We systematically queried databases, including PubMed, the Cochrane Library, Embase, and Scopus, and conducted meta-analyses on studies reporting odds ratios (ORs) related to the association between BP and PSCI. Two authors autonomously assessed all titles, abstracts, and full texts and extracted data following the Meta-Analysis of Observational Studies in Epidemiology guidelines. The quality of the studies was evaluated using the modified Newcastle-Ottawa scale.

Results

Meta-analyses incorporated 12 articles comprising a cumulative participant cohort of 21,732 individuals. The quality assessment indicated good in five studies, fair in one study, and poor in six. Through meta-analyses, we found that hypertension, systolic or diastolic BP (SBP or DBP) was significantly associated with PSCI (OR 1.53, 95% confidence interval (CI), 1.18-1.99; p = 0.001, I 2 = 66%; OR 1.13, 95% CI, 1.05-1.23; p = 0.002, I 2 = 52%; OR 1.38, 95% CI, 1.11-1.72; p = 0.004, I 2 = 90%, respectively). In the subgroup analysis, SBP < 120 mmHg, 120-139 mmHg, 140-159 mmHg, 160-179 mmHg, and DBP ≥ 100 mmHg highly predicted the occurrence of PSCI (OR 1.15, p = 0.0003; OR 1.26, p = 0.010; OR 1.15, p = 0.05; OR 1.02, p = 0.009; OR 1.96, p < 0.00001, respectively). However, the predictive effect of BP for PSCI declines when SBP ≥ 180 mmHg and DBP ≤ 99 mmHg (p > 0.05). Statistical heterogeneity was moderate to high, and publication bias was detected in SBP for PSCI.

Conclusions

Considering the multifactorial etiology of PSCI, it is difficult to conclude that BP is an independent risk factor for PSCI. Given the restricted inclusion of studies, caution is advised when interpreting the findings from this meta-analysis. Subsequent investigations with substantial sample sizes are essential to exploring BP as a prospective target for addressing PSCI.

Trial Registration Number

CRD42023437783 from PROSPERO.

Prevalence and risk factors of cognitive impairment in Chinese patients with hypertension: a systematic review and meta-analysis

Background

Cognitive impairment is prevalent in Chinese patients with hypertension; however, current evidence on prevalence and risk factors is required to be synthesized.

Objectives

This systematic review and meta-analysis aimed to evaluate the prevalence and risk factors of cognitive impairment in Chinese patients with hypertension.

Methods

Two reviewers independently searched PubMed, Web of Science, Embase, The Cochrane Library, CNKI, CBM, the Wanfang database, and the VIP database from their inception to 7 June 2023. The gray literature and the reference lists of the included studies were also retrieved manually. Moreover, we also independently performed the eligibility screening, data extraction, and data synthesis. The primary outcome was the prevalence of cognitive impairment in Chinese patients with hypertension, and the secondary outcomes were the risk factors for cognitive impairment in patients with hypertension. R (version 4.0.3) was used for data synthesis.

Results

In total, 82 studies involving 53,623 patients with hypertension were included in this meta-analysis. The pooled prevalence of cognitive impairment in patients with hypertension was 37.6% (95% CI: 33.2-42.2%). A total of 12 risk factors, including advanced age (r = -0.34, 95% CI: -0.45, -0.21), female sex (OR = 1.15, 95% CI: 1.01-1.32), BMI > 24 Kg/m2 (OR = 1.76, 95% CI: 1.04-3.00), lower educational level (OR = 2.01, 95% CI: 1.10-3.67), single status (OR = 1.63, 95% CI: 1.32-2.02), complications with diabetes (OR = 1.44, 95% CI: 1.14-1.80), coronary heart disease (OR = 1.49, 95% CI: 1.12-1.97), higher stage of hypertension [stage 3 vs. stage 1, OR = 3.08, 95% CI: 1.82-5.22; stage 2 vs. stage 1, OR = 1.83, 95% CI: 1.29-2.60], no regular physical activity (OR = 0.40, 95% CI: 0.21-0.77), higher levels of systolic blood pressure (r = -0.25, 95% CI: -0.42, -0.08), Hcy (r = -0.39, 95% CI: -0.63, -0.09), and IL-6 (r = -0.26, 95% CI: -0.48, -0.02) were detected.

Conclusion

Cognitive impairment is prevalent in Chinese patients with hypertension, and the increased prevalence was associated with several demographic characteristics, complicated disease, no regular physical activity, worse hypertension status (higher stages and SBP), and high levels of biomarkers. Therefore, more attention should be paid to the early identification and treatment of patients with hypertension who are at high risk for cognitive impairment in clinical practice. In addition, relevant risk factors should be controlled to reduce the incidence of cognitive impairment.

Systematic review registration

http://www.crd.york.ac.uk/PROSPERO, identifier [CRD42023410437].

Hypertension & dementia: Pathophysiology & potential utility of antihypertensives in reducing disease burden

Dementia is a common cause of disability and dependency among the elderly due to its progressive neurodegenerative nature. As there is currently no curative therapy, it is of major importance to identify new ways to reduce its prevalence. Hypertension is recognised as a modifiable risk factor for dementia, particularly for the two most common subtypes; vascular dementia (VaD) and Alzheimer's disease (AD). From the current literature, identified through a comprehensive literature search of PubMed and Cochrane Library, this review aims to establish the stage in adulthood when hypertension becomes a risk for cognitive decline and dementia, and whether antihypertensive treatment is effective as a preventative therapy. Observational studies generally found hypertension in mid-life (age 45-64) to be correlated with an increased risk of cognitive decline and dementia incidence, including both VaD and AD. Hypertension manifesting in late life (age ≥ 65) was demonstrated to be less of a risk, to the extent that incidences of high blood pressure (BP) in the very elderly (age ≥ 75) may even be related to reduced incidence of dementias. Despite the evidence linking hypertension to dementia, there were conflicting findings as to whether the use of antihypertensives was beneficial for its prevention and this conflicting evidence and inconsistent results could be due to the methodological differences between the reviewed observational and randomised controlled trials. Furthermore, dihydropyridine calcium channel blockers and potassium-sparing diuretics were proposed to have neuroprotective properties in addition to BP lowering. Overall, if antihypertensives are confirmed to be beneficial by larger-scale homogenous trials with longer follow-up durations, treatment of hypertension, particularly in mid-life, could be an effective strategy to considerably lower the prevalence of dementia. Furthermore, greater clarification of the neuroprotective properties that some antihypertensives possess will allow for better clinical practice guidance on the choice of antihypertensive class for both BP lowering and dementia prevention.

Effect of Huangdisan grain on improving cognitive impairment in VD rats and its mechanism in immune inflammatory response

BACKGROUND

Vascular dementia (VD) is the second most common type of dementia after Alzheimer's disease (AD). Although the incidence rate is very high, there is no definitive treatment for VD. And it has serious impact on the quality of life of VD patients. In recent years, more and more studies about the clinical efficacy and pharmacological effects of traditional Chinese medicine (TCM) in the treatment of VD have been conducted. And Huangdisan grain has been used to treat VD patients with a good curative effect in clinic.

OBJECTIVE

This study was designed to investigate the effect of Huangdisan grain on the inflammatory response and cognitive function of VD rats modeled by bilateral common carotid artery occlusion (BCCAO), that aimed to improve the treatment methods for VD.

METHODS

8-week-old healthy SPF male Wistar rats (280 ± 20 g) were randomly divided into the normal group (Gn, n = 10), sham operated group (Gs, n = 10), and operated group (Go, n = 35). The VD rat models in Go group were established by BCCAO. 8 weeks after surgery, the operated rats were screened by the hidden platform trail of Morris Water Maze (MWM), and the rats with cognitive dysfunction were further randomly divided into the impaired group (Gi, n = 10) and TCM group (Gm, n = 10). The VD rats in Gm group were given the intragastric administration of Huangdisan grain decoction once a day for 8 weeks, and the other groups were given intragastric administration of normal saline. Then the cognitive ability of rats in each group was detected by the MWM Test. The lymphocyte subsets in peripheral blood and hippocampus of rats were measured by flow cytometry. The levels of cytokines (IL-1β, IL-2, IL-4, IL-10, TNF-α, INF-γ, MIP-2, COX-2, iNOS) in peripheral blood and hippocampus were measured by ELISA (enzyme linked immunosorbent assay). The number of Iba-1⁺ CD68⁺ co-positive cells in the CA1 region of hippocampus was measured by immunofluorescence.

RESULTS

Compared with the Gn group, the escape latencies of the Gi group were prolonged (P < 0.01), the time spent in the former platform quadrant was shortened (P < 0.01), and the number of times of crossing over the former platform location was reduced (P < 0.05). But compared with the Gi group, the escape latencies of Gm group were shortened (P < 0.01), the time spent in the former platform quadrant was prolonged (P < 0.05), and the number of times of crossing over the former platform location was increased (P < 0.05). The number of Iba-1⁺ CD68⁺ co-positive cells in the CA1 region of hippocampus of VD rats in Gi group was increased (P < 0.01) compared with the Gn group. And the proportions of T Cells, CD4⁺ T Cells, CD8⁺ T Cells in the hippocampus were increased (P < 0.01). The level of pro-inflammatory cytokines in the hippocampus was increased significantly, such as IL-1β (P < 0.01), IL-2 (P < 0.01), TNF-α (P < 0.05), IFN-γ (P < 0.01), COX-2 (P < 0.01), MIP-2 (P < 0.01) and iNOS (P < 0.05). And the level of IL-10 (P < 0.01), a kind of anti-inflammatory cytokine, was decreased. The proportions of T Cells (P < 0.05), CD4⁺ T Cells (P < 0.01) and NK Cells (P < 0.05) in the peripheral blood of the VD rats in Gi group were decreased, and the level of IL-1β, IL-2, TNF-α, IFN-γ, COX-2, MIP-2 and iNOS was increased significantly (P < 0.01) compared with the Gn group. Meanwhile, the level of IL-4 and IL-10 was decreased (P < 0.01). Huangdisan grain could reduce the number of Iba-1⁺ CD68⁺ co-positive cells in the CA1 region of hippocampus (P < 0.01), decrease the proportions of T Cells, CD4⁺ T Cells, CD8⁺ T Cells and the level of IL-1β, MIP-2 in hippocampus (P < 0.01) of VD rats. Moreover, it could rise the proportion of NK Cells (P < 0.01) and the level of IL-4 (P < 0.05), IL-10 (P < 0.05), and decrease the level of IL-1β (P < 0.01), IL-2 (P < 0.05), TNF-α (P < 0.01), IFN-γ (P < 0.01), COX-2 (P < 0.01) and MIP-2 (P < 0.01) in peripheral blood of VD rats.

CONCLUSION

This study indicated that Huangdisan grain could decrease the activation of microglia/macrophages, regulate the proportions of lymphocyte subsets and the level of cytokines, which could adjust the immunologic abnormalities of VD rats, and ultimately improve cognitive function.

Multimorbidity and Blood Pressure Control in Patients Attending Primary Care in Canada

BACKGROUND

There has been conflicting evidence on the association between multimorbidity and blood pressure (BP) control. This study aimed to investigate this associations in people with hypertension attending primary care in Canada, and to assess whether individual long-term conditions are associated with BP control.

METHODS

This was a cross-sectional study in people with hypertension attending primary care in Toronto between January 1, 2017 and December 31, 2019. Uncontrolled BP was defined as systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg. A list of 11 a priori selected chronic conditions was used to define multimorbidity. Multimorbidity was defined as having ≥1 long-term condition in addition to hypertension. Logistic regression models were used to estimate the association between multimorbidity (or individual long-term conditions) with uncontrolled BP.

RESULTS

A total of 67 385 patients with hypertension were included. They had a mean age of 70, 53.1% were female, 80.6% had multimorbidity, and 35.7% had uncontrolled BP. Patients with multimorbidity had lower odds of uncontrolled BP than those without multimorbidity (adjusted OR = 0.72, 95% CI 0.68-0.76). Among the long-term conditions, diabetes (aOR = 0.73, 95%CI 0.70-0.77), heart failure (aOR = 0.81, 95%CI 0.73-0.91), ischemic heart disease (aOR = 0.74, 95%CI 0.69-0.79), schizophrenia (aOR = 0.79, 95%CI 0.65-0.97), depression/anxiety (aOR = 0.91, 95%CI 0.86-0.95), dementia (aOR = 0.87, 95%CI 0.80-0.95), and osteoarthritis (aOR = 0.89, 95%CI 0.85-0.93) were associated with a lower likelihood of uncontrolled BP.

CONCLUSION

We found that multimorbidity was associated with better BP control. Several conditions were associated with better control, including diabetes, heart failure, ischemic heart disease, schizophrenia, depression/anxiety, dementia, and osteoarthritis.

The Power of Birth Cohorts to Study Risk Factors for Cognitive Impairment

PURPOSE OF REVIEW

Birth cohorts are studies of people the same time; some of which have continuously followed participants across the life course. These are powerful designs for studying predictors of age-related outcomes, especially when information on predictors is collected before these outcomes are known. This article reviews recent findings from these cohorts for the outcomes of cognitive function, cognitive impairment, and risk of dementia, in relation to prior cognitive function, and social and biological predictors.

RECENT FINDINGS

Cognitive function and impairment are predicted by a wide range of factors, including childhood cognition, education, occupational status and complexity, and biological factors, including genetic and epigenetic. The particular importance of high and rising blood pressure in midlife is highlighted, with some insight into brain mechanisms involved. Some limitations are noted, including sources of bias in the data. Despite these limitations, birth cohorts have provided valuable insights into factors across the life course associated with cognitive impairment.

Feasibility of Precision Medicine in Hypertension Management-Scope and Technological Aspects

Personalized management of diseases by considering relevant patient features enables optimal treatment, instead of management according to an average patient. Precision management of hypertension is important, because both susceptibility to complications and response to treatment vary between individuals. While the use of genomic and proteomic personal features for widespread precision hypertension management is not practical, other features, such as age, ethnicity, and cardiovascular diseases, have been utilized in guidelines for hypertension management. In precision medicine, more blood-pressure-related clinical and physiological characteristics in the patient's profile can be utilized for the determination of the threshold of hypertension and optimal treatment. Several non-invasive and simple-to-use techniques for the measurement of hypertension-related physiological features are suggested for use in precision management of hypertension. In order to provide precise management of hypertension, accurate measurement of blood pressure is required, but the available non-invasive blood pressure measurement techniques, auscultatory sphygmomanometry and oscillometry, have inherent significant inaccuracy-either functional or technological-limiting the precision of personalized management of hypertension. A novel photoplethysmography-based technique for the measurement of systolic blood pressure that was recently found to be more accurate than the two available techniques can be utilized for more precise and personalized hypertension management.

Combined association of triglyceride-glucose index and systolic blood pressure with all-cause and cardiovascular mortality among the general population

Background

The combined association of triglyceride-glucose (TyG) index and different systolic blood pressure (SBP) levels with all-cause and cardiovascular mortality among the general population remains unclear.

Methods

In this study, 6245 individuals were from the National Health and Nutrition Examination Survey (1999–2002). The study endpoints were all-cause and cardiovascular mortality. Multivariate Cox proportional hazards regression models were used to explore the combined association of TyG index and different SBP levels with all-cause and cardiovascular mortality.

Results

During a mean follow-up period of 66.8 months, a total of 284 all-cause deaths (331/100000 person-years) and 61 cardiovascular deaths (66/100000 person-years) were recorded. Multivariate Cox regression analysis revealed that the combination of low TyG index and low SBP (< 120 mmHg and < 130 mmHg) was associated with a reduced risk of all-cause and cardiovascular mortality than others. However, survival benefit was not observed in the combined group with the low TyG index and SBP < 140 mmHg. Furthermore, the mortality rate in the combined group of low TyG index and low SBP gradually increased with the elevation of SBP level.

Conclusion

The combination of low TyG index and low SBP (< 120 mmHg and < 130 mmHg) was associated with a lower risk of all-cause and cardiovascular mortality. However, no survival benefit was observed in the combined group of low TyG index and SBP < 140 mmHg.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03678-z.

Relationships between educational attainment, hypertension, and amyloid negative subcortical vascular dementia: The brain-battering hypothesis

Purpose

Many epidemiological studies suggest that lower education levels and vascular risk factors increase the likelihood of developing Alzheimer's disease dementia (ADD) and subcortical vascular dementia (SVaD). However, whether the brain-battering hypothesis can explain the relationship between education levels and the clinical diagnosis of dementia remains controversial. The objective of this study was to investigate whether vascular risk factors mediate the association between education level and the diagnosis of amyloid-beta positive (Aβ+) ADD and amyloid-beta negative (Aβ-) SVaD.

Methods

We analyzed 376 participants with Aβ normal cognition (Aβ- NC), 481 with Aβ+ ADD, and 102 with Aβ- SVaD. To investigate the association of education level and vascular risk factors with these diagnoses, multivariable logistic regression analysis was used, with age, sex, and APOE ε4 carrier status used as covariates. Path analysis was performed to investigate the mediation effects of hypertension on the diagnosis of Aβ- SVaD.

Results

The Aβ- SVaD group (7.9 ± 5.1 years) had lower education levels than did the Aβ- NC (11.8 ± 4.8 years) and Aβ+ ADD (11.2 ± 4.9 years) groups. The frequencies of hypertension and diabetes mellitus were higher in the Aβ- SVaD group (78.4 and 32.4%, respectively) than in the Aβ- NC (44.4 and 20.8%) and Aβ+ ADD (41.8 and 15.8%, respectively) groups. Increased education level was associated with a lower risk of Aβ- SVaD [odds ratio (OR) 0.866, 95% confidence interval (CI), 0.824–0.911], but not Aβ+ ADD (OR 0.971, 95% CI 0.940–1.003). The frequency of hypertension was associated with a higher risk of developing Aβ- SVaD (OR 3.373, 95% CI, 1.908–5.961), but not Aβ+ ADD (OR 0.884, 95% CI, 0.653–1.196). In the path analysis, the presence of hypertension partially mediated the association between education level and the diagnosis of Aβ- SVaD.

Conclusion

Our findings revealed that education level might influence the development of Aβ- SVaD through the brain-battering hypothesis. Furthermore, our findings suggest that suitable strategies, such as educational attainment and prevention of hypertension, are needed for the prevention of Aβ- SVaD.

Increased Blood Pressure Variability and the Risk of Probable Dementia or Mild Cognitive Impairment: A Post Hoc Analysis of the SPRINT MIND Trial

Background

Increased systolic blood pressure variability (BPV) is associated with stroke, cardiovascular disease, and dementia and mild cognitive impairment. However, prior studies assessing the relationship between BPV and dementia or mild cognitive impairment had infrequent measurement of blood pressure or suboptimal blood pressure control.

Methods and Results

We performed a post hoc analysis of the SPRINT (Systolic Blood Pressure Intervention Trial) MIND (Memory and Cognition in Decreased Hypertension) trial. The primary outcome was probable dementia during follow‐up. We defined our exposure period, during which blood pressures were collected, as the first 600 days of the trial, and outcomes were ascertained during the subsequent follow‐up. BPV was measured as tertiles of systolic blood pressure standard deviation. We fit Cox proportional hazards models to our outcome. We included 8379 patients. The mean follow‐up was 3.2±1.4 years, during which 316 (3.8%) patients developed dementia. The mean number of blood pressure measurements was 7.8, and in the tertiles of BPV, the SD was 6.3±1.6, 10.3±1.1, and 16.3±3.6 mm Hg, respectively. The rate of dementia was 2.4%, 3.6%, and 5.4% by ascending tertile, respectively (P<0.001). In the Cox models, compared with the lowest tertile of BPV, the highest tertile of BPV increased the risk of dementia in both unadjusted (hazard ratio [HR], 2.36; 95% CI, 1.77–3.15) and adjusted (HR, 1.69; 95% CI, 1.25–2.28) models.

Conclusions

In a post hoc analysis of the SPRINT MIND trial, we found that higher BPV was associated with the development of probable dementia despite excellent blood pressure control. Additional research is needed to understand how to reduce BPV and if its reduction lowers the risk of cognitive impairment and dementia.

Orthostatic hypotension assessed by active standing is associated with worse cognition in geriatric rehabilitation inpatients, RESORT

PURPOSE

Geriatric rehabilitation inpatients who suffer from acute and chronic diseases that aggravate blood pressure (BP) dysregulation, may be particularly susceptible to orthostatic hypotension (OH). OH may increase the risk of cerebral small vessel disease and subsequent white matter hyperintensities inducing cognitive impairment (CI). This study investigates the association between OH and cognition in geriatric rehabilitation inpatients.

MATERIALS AND METHODS

Geriatric rehabilitation inpatients of the observational, longitudinal REStORing health of acutely unwell adulTs (RESORT) cohort in Melbourne, Australia, underwent intermittent BP measurements during active standing or partial postural change to sitting (when unable to stand). OH was defined as a systolic BP drop ≥20 mmHg and/or diastolic BP drop ≥10 mmHg within three minutes after postural change. CI included dementia diagnosis, Mini-Mental State Examination (MMSE) score <24 points (categorized as 18-23 (mild CI) and <18 points (severe CI)), Montreal Cognitive Assessment score <26 points or Rowland Universal Dementia Assessment Scale score <23 points.

RESULTS

In geriatric rehabilitation inpatients (n=1232, mean age 82.3 years (SD 8.2), 57.5% female), OH, CI and dementia prevalence was 20.0%, 61.0% and 20.4% respectively. MMSE was scored 18-23 in 32.6% and <18 points in 27.8% of patients (n=1033). In standing patients (51.7%), OH was associated with CI (p=0.045) and dementia (p=0.021), with a trend for MMSE scores <18 points (p=0.080), but not for MMSE scores 18-23 points (p=0.528). No association was found between seated OH and cognition.

CONCLUSION

OH assessed by active standing using intermittent BP measurements was associated with worse cognition in geriatric rehabilitation inpatients.

The Utility of Cerebrovascular Reactivity MRI in Brain Rehabilitation: A Mechanistic Perspective

Cerebrovascular control and its integration with other physiological systems play a key role in the effective maintenance of homeostasis in brain functioning. Maintenance, restoration, and promotion of such a balance are one of the paramount goals of brain rehabilitation and intervention programs. Cerebrovascular reactivity (CVR), an index of cerebrovascular reserve, plays an important role in chemo-regulation of cerebral blood flow. Improved vascular reactivity and cerebral blood flow are important factors in brain rehabilitation to facilitate desired cognitive and functional outcomes. It is widely accepted that CVR is impaired in aging, hypertension, and cerebrovascular diseases and possibly in neurodegenerative syndromes. However, a multitude of physiological factors influence CVR, and thus a comprehensive understanding of underlying mechanisms are needed. We are currently underinformed on which rehabilitation method will improve CVR, and how this information can inform on a patient's prognosis and diagnosis. Implementation of targeted rehabilitation regimes would be the first step to elucidate whether such regimes can modulate CVR and in the process may assist in improving our understanding for the underlying vascular pathophysiology. As such, the high spatial resolution along with whole brain coverage offered by MRI has opened the door to exciting recent developments in CVR MRI. Yet, several challenges currently preclude its potential as an effective diagnostic and prognostic tool in treatment planning and guidance. Understanding these knowledge gaps will ultimately facilitate a deeper understanding for cerebrovascular physiology and its role in brain function and rehabilitation. Based on the lessons learned from our group's past and ongoing neurorehabilitation studies, we present a systematic review of physiological mechanisms that lead to impaired CVR in aging and disease, and how CVR imaging and its further development in the context of brain rehabilitation can add value to the clinical settings.

Systolic blood pressure postural changes variability is associated with greater dementia risk

OBJECTIVE

To determine whether orthostatic hypotension (OHYPO) and visit-to-visit blood pressure (BP) postural changes variability are associated with incident dementia.

METHODS

We studied 2,131 older adults from the Health, Aging, and Body Composition cohort study. Orthostatic BP was repeatedly assessed over a 5-year baseline period. OHYPO was defined as a fall ≥15 mm Hg in systolic or ≥7 mm Hg in diastolic BP after standing from a sitting position for one-third or more of the visits. Systolic OHYPO and diastolic OHYPO were also examined separately. BP postural changes variability over time was evaluated with several indicators, including SD and coefficient of variation (CV). Incident dementia was determined over 12 years after the baseline period by dementia medication use, ≥1.5 SD decline in Modified Mini-Mental State Examination score, or hospitalization records.

RESULTS

Of 2,131 participants (mean age 73 years, 53% female, 39% Black), 309 (14.5%) had OHYPO, 192 (9.0%) had systolic OHYPO, 132 (6.2%) had diastolic OHYPO, and 462 (21.7%) developed dementia. After adjustment for demographics, seated systolic BP (SBP), antihypertensive drugs, cerebrovascular disease, diabetes mellitus, depressive symptoms, smoking, alcohol, body mass index, and presence of 1 or 2 APOE ε4 alleles, systolic OHYPO was associated with greater dementia risk (adjusted hazard ratio [HR] 1.37, 95% confidence interval [CI] 1.01-1.88), unlike diastolic OHYPO and OHYPO. SBP postural changes variability was also associated with higher dementia risk (highest tertile of variability [CV]: adjusted HR 1.35, 95% CI 1.06-1.71).

CONCLUSION

Systolic OHYPO and visit-to-visit SBP postural changes variability were associated with greater dementia risk. Our findings raise the question of potential preventive interventions to control orthostatic SBP and its fluctuations.

Double-blinded, placebo-controlled crossover trial to determine the effects of midodrine on blood pressure during cognitive testing in persons with SCI

Study Design:

Clinical trial.

Objectives:

Individuals with spinal cord injury (SCI) above T6 experience impaired descending cortical control of the autonomic nervous system which predisposes them to hypotension. However, treatment of hypotension is uncommon in the SCI population because there are few safe and effective pharmacological options available. The primary aim of this investigation was to test the efficacy of a single dose of midodrine (10 mg), compared to placebo, to increase and normalize systolic blood pressure (SBP) between 110–120 mmHg during cognitive testing in hypotensive individuals with SCI. Secondary aims were to determine the effects of midodrine on cerebral blood flow velocity (CBFv) and global cognitive function.

Setting:

United States clinical research laboratory.

Methods:

Forty-one healthy hypotensive individuals with chronic (≥ 1-year post-injury) SCI participated in this 2-day study.

Seated SBP, CBFv, cognitive performance were monitored before and after administration of identical encapsulated tablets, containing either midodrine or placebo.

Results:

Compared to placebo, midodrine increased SBP (4±13 vs. 18±24 mmHg, respectively; p<0.05); however, responses varied widely with midodrine (−15.7 to +68.6 mmHg). Further, the proportion of SBP recordings within the normotensive range did not improve during cognitive testing with midodrine compared to placebo. Although higher SBP was associated with higher CBFv (p=0.02), global cognitive function was not improved with midodrine.

Conclusions:

The findings indicate that midodrine increases SBP and may be beneficial in some hypotensive patients with SCI; however, large heterogeneity of responses to midodrine suggest careful monitoring of patients following administration.

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.

Is Baseline Orthostatic Hypotension Associated With a Decline in Global Cognitive Performance at 4-Year Follow-Up? Data From TILDA (The Irish Longitudinal Study on Ageing)

Background It is postulated that orthostatic hypotension ( OH ), a reduction in blood pressure (≥20/10 mm Hg) within 3 minutes of standing, may increase cognitive decline because of cerebral hypoperfusion. This study assesses the impact of OH on global cognition at 4-year follow-up, and the impact of age and hypertension on this association. Methods and Results Data from waves 1 and 3 of TILDA (The Irish Longitudinal Study on Ageing) were used. Baseline blood pressure response to active stand was assessed using beat-to-beat blood pressure monitoring. Two measures of OH were used-at 40 seconds ( OH 40) and 110 seconds ( OH 110). Global cognition was measured using the Montreal Cognitive Assessment. Mixed-effects Poisson regression assessed whether baseline OH was associated with a decline in global cognition at 4-year follow-up. The analysis was repeated, stratifying by age (age 50-64 years and age ≥65 years), and including an interaction between OH and hypertension. Baseline OH 110 was associated with an increased error rate in Montreal Cognitive Assessment at follow-up (incident rate ratio 1.17, P=0.028). On stratification by age, the association persists in ages 50 to 64 years (incident rate ratio 1.25, P=0.048), but not ages ≥65 years. Including an interaction with hypertension found those with co-existent OH 110 and hypertension (incident rate ratio 1.27, P=0.011), or OH 40 and hypertension (incident rate ratio 1.18, P=0.017), showed an increased error rate; however, those with isolated OH 110, OH 40, or isolated hypertension did not. Conclusions OH is associated with a decline in global cognition at 4-year follow-up, and this association is dependent on age and co-existent hypertension.

Predictors of Orthostatic Hypotension in the Elderly: Results from the Amirkola Health and Ageing Project (AHAP) Study

Background: Orthostatic hypotension (OH) in the elderly is an important health challenge that poses a significant burden. We sought to determine the prevalence and correlates of OH in an elderly population-based study. Methods: This study was conducted within the framework of the Amirkola Health and Ageing Project (AHAP) on 1,588 elderly individuals aged ≥60 years. The baseline measurement was performed from April 2011 to July 2012. The relationships between OH (dependent variable) and age, sex, diabetes, hypertension, and cognitive status (independent variables) were investigated by logistic regression. Results: The mean age of the participants was 69.37±7.42 years (men: 69.96±7.68 y, women: 68.66±7.02 y). The prevalence of OH was 10.7%: 8.4% in the male and 13.7% in the female patients. In the final model, hypertension (OR=2.4, 95% CI: 1.6-3.7), diabetes (OR=1.3, 95% CI: 1.0-1.9), age (OR=2.9, 95% CI: 1.7-4.8), and female sex (female [OR=1.6, 95% CI: 1.1-2.3]) were significantly correlated with OH. Conclusion: The prevalence of OH in our elderly subjects increased with age. Additionally, the older participants with diabetes and hypertension had a higher likelihood of having this OH.

Small vessel disease to subcortical dementia: a dynamic model, which interfaces aging, cholinergic dysregulation and the neurovascular unit

Background

Small vessels have the pivotal role for the brain’s autoregulation. The arteriosclerosis-dependent alteration of the brain perfusion is one of the major determinants in small vessel disease. Endothelium distress can potentiate the flow dysregulation and lead to subcortical vascular dementia (sVAD). sVAD increases morbidity and disability. Epidemiological studies have shown that sVAD shares with cerebrovascular disease most of the common risk factors. The molecular basis of this pathology remains controversial.

Purpose

To detect the possible mechanisms between small vessel disease and sVAD, giving a broad vision on the topic, including pathological aspects, clinical and laboratory findings, metabolic process and cholinergic dysfunction.

Methods

We searched MEDLINE using different search terms (“vascular dementia”, “subcortical vascular dementia”, “small vessel disease”, “cholinergic afferents”, etc). Publications were selected from the past 20 years. Searches were extended to Embase, Cochrane Library, and LILIACS databases. All searches were done from January 1, 1998 up to January 31, 2018.

Results

A total of 560 studies showed up, and appropriate studies were included. Associations between traditional vascular risk factors have been isolated. We remarked that SVD and white matter abnormalities are seen frequently with aging and also that vascular and endothelium changes are related with age; the changes can be accelerated by different vascular risk factors. Vascular function changes can be heavily influenced by genetic and epigenetic factors.

Conclusion

Small vessel disease and the related dementia are two pathologies that deserve attention for their relevance and impact in clinical practice. Hypertension might be a historical problem for SVD and SVAD, but low pressure might be even more dangerous; CBF regional selective decrease seems to be a critical factor for small vessel disease-related dementia. In those patients, endothelium damage is a super-imposed condition. Several issues are still debatable, and more research is needed.

LRRTM4 and PCSK5 Genetic Polymorphisms as Markers for Cognitive Impairment in A Hypotensive Aging Population: A Genome-Wide Association Study in Taiwan

Hypotension can affect cerebral perfusion and worsen cognitive outcomes. The prevalence of low blood pressure (BP) rises with increasing age. To our knowledge, no study has examined the genetic biomarkers for hypotension-related cognitive impairment (CI) yet. Utilizing the population-based genome-wide study of the Taiwan Biobank containing the data of 2533 healthy aging subjects, we found after adjustments for age, sex, education years, and principal components at a suggestive level of 1 × 10⁻⁵ that minor alleles of leucine rich repeat transmembrane neuronal 4 (LRRTM4) (rs13388459, rs1075716, rs62171995, rs17406146, rs2077823, and rs62170897), proprotein convertase subtilisin/kexin type 5 (PCSK5) (rs10521467), and the intergenic variation rs117129097 (the nearby gene: TMEM132C) are risk factors for CI in hypotensive subjects. Except for rs117129097, these single nucleotide polymorphisms (SNPs) were not markers per se for CI or for BP regulation. However, we found a suggestive interaction effect between each of the eight SNPs and hypotension on CI risk. In the hypotensive participants, those carrying minor alleles were associated with a higher incidence of CI in an additive manner than were those carrying major alleles (2 × 10⁻⁴ to 9 × 10⁻⁷). Intensive BP lowering in elderly patients carrying a minor allele of the eight identified SNPs should raise cautions to prevent a potential treatment-induced neurodegeneration.

Comparative analysis of cognitive impairment prevalence and its etiological subtypes in a rural area of northern China between 2010 and 2015

The purpose of this study was to evaluate changes in the prevalence and risk factors of cognitive impairment (CI) by analyzing and comparing two cross-sectional epidemiological surveys of CI and its subtypes were performed in a rural area of northern China between 2010 and 2015. Residents aged ≥60 years were drawn in northern China. The Mini Mental State Examination (MMSE) is recommended to test for CI. Dementia was further categorised into Alzheimer’s disease (AD), vascular dementia (VaD), and dementia caused by other diseases (ODs). Mild cognitive impairment (MCI) was classified into MCI caused by AD (MCI-A), MCI caused by VaD (MCI-VD), and MCI caused by ODs (MCI-O). The prevalence of CI increased in China. The prevalence of all-cause CI was 30·5% (22.9% MCI and 7.6% dementia) in 2010. The prevalence of all-cause CI was 38.3% (27.8% MCI and 10.5% dementia) in 2015. Similar increases were observed for the prevalence of subtypes of dementia and MCI. These findings suggest an increasing prevalence of CI and its subtypes in China, which may be related to alterations in sociodemographic factors, vascular risk factors and lifestyle changes over time in these cohorts.

APOE Genotype Influences Postprandial Blood Pressure after High Fat Feeding in Older Adults

OBJECTIVE

Postprandial hypotension (PPH) is a common phenomenon among older adults. The degree to which individuals experience PPH is related to cerebrovascular risk factors and the presence of neurodegenerative diseases such as Alzheimer's disease (AD). Carrier status of the E4 allele of the apolipoprotein E (APOE) gene is a risk factor for AD and influences a variety of responses to metabolic and dietary interventions. However, it is unknown whether APOE genotype influences the risk of PPH and whether type of meal can mediate that response.

DESIGN

Acute meal study with a crossover design.

PARTICIPANTS

32 cognitively healthy older adults with (n=18) and without (n=14) E4+ carrier status.

INTERVENTION

As a part of an ongoing meal study we examined the postprandial blood pressure response after ingestion of a high carbohydrate (HCM) and high fat meal (HFM).

MEASUREMENTS

Blood pressure measurements were taken at 7 time points and change scores, area under the curve (AUC) scores were calculated. Data were analyzed by repeated measures ANOVA as well as Pearson correlation.

RESULTS

Both meals produced a sustained drop in systolic (SBP) and diastolic (DBP) blood pressure, with 37.5% of participants meeting criteria for PPH. Participants carrying the E4+ risk gene experienced a larger decrease in SBP than E4- participants, and this was significantly different after the HFM (E4+ AUC = -30.8 ± 7.6, E4- AUC = -0.2 ± 8.7, p=0.015). Increasing age was associated with a larger drop in postprandial blood pressure but only for the E4+ group after the HFM (p=0.002).

CONCLUSIONS

These data suggest that E4+ individuals experience a greater postprandial blood pressure response particularly following high fat feeding, and this effect becomes more pronounced with age. The prevalence of PPH may play a role in the development of AD and may be mediated by diet.

Effects of Blood Pressure in the Early Phase of Ischemic Stroke and Stroke Subtype on Poststroke Cognitive Impairment

BACKGROUND AND PURPOSE

Blood pressure (BP) control in the early phase of stroke is controversial to reduce the risk of poststroke cognitive impairment (PSCI). This study was to investigate the impact of BP levels in the early phase of ischemic stroke and stroke subtype on PSCI.

METHODS

Seven hundred and ninety-six patients with acute ischemic stroke were included. Cognitive function was assessed after stroke onset using the Montreal Cognitive Assessment. Patients were divided into quintiles according to systolic BP and diastolic BP levels in the early phase. Subtype analyses were according to Trial of ORG 10172 in Acute Stroke Treatment classification (infarct cause) and Oxfordshire Community Stroke Project classification (infarct location).

RESULTS

After adjusting for multiple variables, the quintiles with the lowest systolic BP (Q1, 102-127 mm Hg) and with the highest systolic BP (Q5, 171-215 mm Hg) were associated with increased PSCI risk (odds ratio, 1.83; 95% confidence interval, 1.64-2.28; P=0.007 in Q1; odds ratio, 2.32; 95% confidence interval, 1.74-2.90; P<0.001 in Q5) at 3 months as compared with the middle quintile (Q3, 143-158 mm Hg). Similar association was found in diastolic BP quintiles. The analysis of cerebral infarction subtype demonstrated that both large artery atherosclerosis and total anterior circulation infarct were associated with increased risk of PSCI at 3 months after adjusting for multiple variables (large artery atherosclerosis: odds ratio, 1.42; 95% confidence interval, 1.06-1.90; P=0.031; total anterior circulation infarct: odds ratio, 1.68; 95% confidence interval, 1.32-2.15; P=0.001).

CONCLUSIONS

Lower or higher BP in the early phase of ischemic stroke was correlated with increased PSCI risk at 3 months. Maintaining systolic/diastolic BP in the levels of 143 to 158/93 to 102 mm Hg might be beneficial to reduce the occurrence of PSCI. Moreover, large artery atherosclerosis subtype and total anterior circulation infarct subtype were correlated with increased PSCI risk at 3 months.

CLINICAL TRIAL REGISTRATION

URL: https://www.chictr.org. Unique identifier: ChiCTR-TRC-14004804.

Betulinic acid, a natural PDE inhibitor restores hippocampal cAMP/cGMP and BDNF, improve cerebral blood flow and recover memory deficits in permanent BCCAO induced vascular dementia in rats

Vascular dementia (VaD) is the second most common form of senile dementia, embraces memory deficits, neuroinflammation, executive function damage, mood and behavioral changes and abnormal cerebral blood flow. The purpose of the study was to explore the therapeutic potential of betulinic acid in bilateral common carotid artery occlusion (BCCAO) induced VaD in experimental rats. VaD was induced by BCCAO in rats and betulinic acid (10 and 15 mg/kg/day po) was administered 1 week after surgery. The cerebral blood pressure of the animal was recorded before and after the treatment using Laser Doppler flow meter. Object recognition task for non-spatial, Morris water maze for spatial and locomotor activity was performed to evaluate behavioral changes in rats. At the end of the study, animals were decapitated and hippocampus was separated to perform biochemical, neuroinflammatory and second messengers cAMP/cGMP analysis. Histology was done to study the brain pathophysiology. BCCAO surgery was able to significantly impaired memory in rats as observed behavioral and biochemical parameters. Moreover, BA demonstrated a neuroprotective effect in a dose-dependent manner. BA was able to re-establish cerebral blood flow, restore behavioral parameters and showed significant improvements in the as cAMP,cGMP and BDNF levels, restrain the oxidative stress and inflammatory parameters. In histopathology, betulinic acid treated groups showed a decrease in microgliosis and less pathological abnormalities comparable to diseased rat's brain. The observed effect might be attributed to the neuroprotective potential of betulinic acid and its ability to restore cognitive impairment and hippocampal neurochemistry in VaD.

Prevalence of hypotension and its association with cognitive function among older adults

BACKGROUND AND OBJECTIVE

The negative effect of hypertension has overshadowed possible health problems associated with hypotension. The purposes of this study were to describe the prevalence of hypotension in older adults and to determine the association between hypotension and cognitive function, after adjusting for possible covariates.

METHODOLOGY

The data for the study consisting of 1067 community-dwelling older adults were obtained from a national survey entitled "Identifying Psychosocial and Identifying Economic Risk Factor of Cognitive Impairment among Elderly", conducted in Malaysia. The hypotension was considered as blood pressure <120/75 mm Hg, measuring by standard mercury manometer. Data analysis was performed using the SPSS Version 22.0.

RESULTS

The mean age of the respondents was 68.27 (SD = 5.93). Mean score of cognitive function as measured by MMSE was 22.70 (SD = 4.95). The prevalence of hypotension was 29.3%. The prevalence of cognitive impairment for hypotension group was 25.6%. Results of multiple linear regression analysis revealed that hypotension is negatively associated with cognitive function (Beta = -0.11, p<.01), after adjusting for age, gender, education, marital status, employment status, diabetes, heart disease, stroke and gastritis.

CONCLUSION

The study showing hypotension is significantly associated with decreased cognitive function in later life, implies more attention to low blood pressure in old age.

Immunological, vascular, metabolic, and autonomic changes seen with aging possible implications for poor outcomes in the elderly following decompressive hemicraniectomy for malignant MCA stroke: a critical review

INTRODUCTION

Stroke is one of the leading causes of mortality and morbidity worldwide and requires rapid and intensive treatment to prevent adverse outcomes. Decompressive hemicraniectomy stands as the gold standard for surgical resolution of the intracranial swelling which accompanies cerebral infarction; however, the benefits of this procedure are not as well achieved in the elderly (age >65 years) compared to the younger population.

EVIDENCE ACQUISITION

This is a critical review performed on all available literature relating to middle cerebral artery (MCA) stroke in the elderly with emphasis on articles examining causality of adverse outcomes in this group over younger populations. Utilizing PRISMA guidelines, we initially identified 1462 articles.

EVIDENCE SYNTHESIS

After screening, four clear areas of physiological change associated with aging were identified and expounded upon as they relate to MCA stroke. These four areas include: immunological, autonomic, mitochondrial, and vascular changes. Elderly patients have a decreased and declining capacity to regulate the inflammation that develops postinfarction and this contributes to adverse outcomes from a neurological stand point. Additionally, aging decreases the ability of elderly patients to regulate their autonomic system resulting in aberrant blood pressures systemically post infarction. With age, the mitochondrial response to ischemia is exaggerated and causes greater local damage in elderly patients compared to younger populations. Finally, there are numerous vascular changes that occur with age including accumulation of homocysteine and atherosclerosis which together contributed to decreased structural integrity of the vasculature in the elderly and render decreased support to the recovery process post infarction.

CONCLUSIONS

We conclude that physiological changes inherent in the aging process serve to intensify adverse outcomes that are commonly associated with strokes in the elderly. Identification and subsequent minimization of these risk factors could allow for more effective management of elderly patients, post stroke, and promote better clinical outcomes.

Screening for mild cognitive impairment in patients with cardiovascular risk factors

AIM

Cardiovascular risk factors are also risk factors for cognitive impairment. They have cumulative effect in target organ damage. The precise correlation between cardiovascular risk factors and cognitive impairment, as well as assessing the extent to which they may affect cognitive functioning, is difficult to ascertain in everyday clinical practice. Quick, specific, and sensitive neuropsychological tests may be useful in screening for, and the prophylaxis of, target organ damage in hypertensive patients.

METHODS

We gathered full anamnesis, performed physical examination, laboratory screening and echocardiography. These variables were observed at office and home for all patients, For half of the patients, 24-hour ambulatory blood pressure monitoring and neuropsychological testing using Montreal Cognitive Assessment (MoCA), Mini Mental State Examination (MMSE), Geriatric Depression Scale, and the 4-instrumental activities of daily living scale were undertaken.

RESULTS

For a period of 2 years, 931 patients were included after applying the inclusion and exclusion criteria. The mean age was 65.90±10.00 years. Two hundred and sixty three patients (85 [32.32%] males and 178 [67.68%] females) were reevaluated after a mean follow-up period of 12 months (6-20 months). The mean results of MoCA and MMSE were significantly lower (p<0.05) in the group of patients with poorly controlled blood pressure and cardiovascular risk factors. There was mild to intermediate negative correlation between Systematic Coronary Risk Evaluation (SCORE) and the neuropsychological tests' results.

CONCLUSION

Cardiovascular risk factors play an important role for the development of cognitive impairment in the eastern European population because of their high frequency and interaction. The use of easily applicable neuropsychological tests in everyday clinical practice of specialties other than neurology may help in stratifying the risk for development and progression of mild cognitive impairment in this high-risk group.

Cerebral Autoregulation in Hypertension and Ischemic Stroke: A Mini Review

Aging and chronic hypertension are associated with dysfunction in vascular smooth muscle, endothelial cells, and neurovascular coupling. These dysfunctions induce impaired myogenic response and cerebral autoregulation, which diminish the protection of cerebral arterioles to the cerebral microcirculation from elevated pressure in hypertension. Chronic hypertension promotes cerebral focal ischemia in response to reductions in blood pressure that are often seen in sedentary elderly patients on antihypertensive therapy. Cerebral autoregulatory dysfunction evokes Blood-Brain Barrier (BBB) leakage, allowing the circulating inflammatory factors to infiltrate the brain to activate glia. The impaired cerebral autoregulation-induced inflammatory and ischemic injury could cause neuronal cell death and synaptic dysfunction which promote cognitive deficits. In this brief review, we summarize the pathogenesis and signaling mechanisms of cerebral autoregulation in hypertension and ischemic stroke-induced cognitive deficits, and discuss our new targets including 20-Hydroxyeicosatetraenoic acid (20-HETE), Gamma-Adducin (Add3) and Matrix Metalloproteinase-9 (MMP-9) that may contribute to the altered cerebral vascular function.

Systolic orthostatic hypotension is related to lowered cognitive function: Findings from the Maine-Syracuse Longitudinal Study

The aim of the present study was to examine the relationship between orthostatic changes in blood pressure (BP) and cognition, with consideration given to cardiovascular risk factors and lifestyle variables. The cross-sectional analysis included 961 community-dwelling participants of the Maine-Syracuse Longitudinal Study, for whom BP clinic measures (five sitting, five recumbent, and five standing) were obtained. Eighteen percent of participants had orthostatic hypotension (fall in systolic BP ≥20 mm Hg or diastolic BP ≥10 mm Hg upon standing) and 6% had orthostatic hypertension (rise in systolic BP ≥20 mm Hg). Orthostatic hypotension and hypertension defined using traditional criteria were unrelated to cognition with covariate adjustment. However, an examination of systolic and diastolic BP change independently revealed that participants with systolic orthostatic hypotension had poorer global cognition, verbal memory, and scanning and tracking scores than those with normal systolic BP change. The authors conclude that systolic orthostatic hypotension is significantly associated with reduced cognitive function.

More accurate systolic blood pressure measurement is required for improved hypertension management: a perspective

The commonly used techniques for systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurement are the auscultatory Korotkoff-based sphygmomanometry and oscillometry. The former technique is relatively accurate but is limited to a physician's office because its automatic variant is subject to noise artifacts. Consequently, the Korotkoff-based measurement overestimates the blood pressure in some patients due to white coat effect, and because it is a single measurement, it cannot properly represent the variable blood pressure. Automatic oscillometry can be used at home by the patient and is preferred even in clinics. However, the technique's accuracy is low and errors of 10-15 mmHg are common. Recently, we have developed an automatic technique for SBP measurement, based on an arm pressure cuff and a finger photoplethysmographic probe. The technique was found to be significantly more accurate than oscillometry, and comparable to the Korotkoff-based technique, the reference-standard for non-invasive blood pressure measurements. The measurement of SBP is a mainstay for the diagnosis and follow-up of hypertension, which is a major risk factor for several adverse events, mainly cardiovascular. Lowering blood pressure evidently reduces the risk, but excessive lowering can result in hypotension and consequently hypoperfusion to vital organs, since blood pressure is the driving force for blood flow. Erroneous measurement by 10 mmHg can lead to a similar unintended reduction of SBP and may adversely affect patients treated to an SBP of 120-130 mmHg. In particular, in elderly patients, unintended excessive reduction of blood pressure due to inaccurate SBP measurement can result in cerebral hypoperfusion and consequent cognitive decline. By using a more accurate technique for automatic SBP measurement (such as the photoplethysmographic-based technique), the optimal blood pressure target can be achieved with lower risk for hypotension and its adverse events.

Association between blood pressure and Alzheimer disease measured up to 27 years prior to diagnosis: the HUNT Study

Background

A lot of attention has been paid to the relationship of blood pressure and dementia because epidemiological research has reported conflicting evidence. Observational data has shown that midlife hypertension is a risk factor for cognitive decline and dementia later in life, whereas there is evidence that low blood pressure is predictive in later life. The aim of the present study was to examine the association between dementia and blood pressure measured up to 27 years (mean 17.6 years) prior to ascertainment.

Methods

In Nord-Trøndelag County, Norway, incident dementia data were collected during 1995–2011, and the diagnoses were validated by a panel of experts in the field. By using the subjects’ personal identification numbers, the dementia data were linked to data from the Nord-Trøndelag Health Study (the HUNT Study), a large, population-based health study performed in 1984–1986 (HUNT 1) and 1995–1997 (HUNT 2). A total of 24,638 participants of the HUNT Study were included in the present study, 579 of whom were diagnosed with Alzheimer disease, mixed Alzheimer/vascular dementia, or vascular dementia. Multiple logistic regression analyses were conducted to analyze the association between dementia and blood pressure data from HUNT 1 and HUNT 2.

Results

Over the age of 60 years, consistent inverse associations were observed between systolic blood pressure and all-cause dementia, mixed Alzheimer/vascular dementia, and Alzheimer disease, but not with vascular dementia, when adjusting for age, sex, education, and other relevant covariates. This was observed for systolic blood pressure in both HUNT 1 and HUNT 2, regardless of antihypertensive medication use. There was an adverse association between systolic blood pressure, pulse pressure, and Alzheimer disease in individuals treated with antihypertensive medication under the age of 60 years.

Conclusions

Our data are in line with those in previous studies demonstrating an inverse association between dementia and systolic blood pressure in individuals over the age of 60 years. We cannot exclude a survival effect, however. Among middle-aged subjects (<60 years), elevated systolic blood pressure and pulse pressure were associated with eventual Alzheimer disease in individuals who reported using antihypertensive medication.

Electronic supplementary material

The online version of this article (doi:10.1186/s13195-017-0262-x) contains supplementary material, which is available to authorized users.

Factors Influencing Decision Making for Carotid Endarterectomy versus Stenting in the Very Elderly

As the population ages worldwide, the number of elderly patients with carotid stenosis is also increasing. There have been many large clinical trials comparing carotid endarterectomy (CAE) versus stenting, but the inclusion criteria (i.e., symptomatic or asymptomatic), stenting methods (i.e., protection device), and primary end point (i.e., the definition of myocardial infarction and follow-up period) were different between trials. Therefore, the interpretation of those results is difficult and requires attention. When it comes to age, the patients older than 80 years were excluded or stratified to a high risk group in previous landmark trials. However, a recent guideline recommended that endarterectomy may be associated with lower stroke risk compared with carotid artery stenting in patients older than 70 years with symptomatic carotid disease. The annual risk of stroke in individuals with asymptomatic carotid stenosis is about 1-3% but the risk is about 4-12% with symptomatic stenosis without carotid intervention. Although the outcome of CAE is better than that of carotid stenting in patients older than 70 years, the perioperative risk is higher in older patients. Therefore, it is important to classify high risk patients and consider underlying disability and life expectancy of very elderly patients before deciding whether to undergo a carotid intervention. In addition, we should also consider that the stroke rate with intensive medical treatment is unknown and is currently being investigated in randomized controlled trials. Intensive medical treatment includes high intensity statins, diabetes and blood pressure control, and aggressive antiplatelet treatment. The aim of this review is to report the factors that may be responsible for the variability in the treatment of carotid stenosis, particularly in the elderly population. This will allow the readers to integrate the current available evidence to individualize the treatment of carotid stenosis in this challenging population.

Neurogenic orthostatic hypotension and supine hypertension in Parkinson's disease and related synucleinopathies: prioritisation of treatment targets

Neurogenic orthostatic hypotension and supine hypertension are common manifestations of cardiovascular dysautonomia in Parkinson's disease and related synucleinopathies. Because these disorders are haemodynamic opposites, improvement in one might be achieved at the expense of worsening of the other. Thus, management decisions necessitate assessment of the individual risks for patients with coexistent neurogenic orthostatic hypotension and supine hypertension. Whereas neurogenic orthostatic hypotension poses risks for falls and can be associated with cognitive impairment in the short term, chronic supine hypertension can be associated with stroke and myocardial infarction in the long term. Because few clinical trial data exist for outcomes in patients with coexistent neurogenic orthostatic hypotension and supine hypertension, clinicians need to balance, on the basis of comorbidities and disease staging, the potential immediate benefits of treatment for neurogenic orthostatic hypotension and the long-term risks of supine hypertension treatment in each patient. Future research needs to focus on ascertaining a safe degree of supine hypertension when treating neurogenic orthostatic hypotension; the effectiveness of nocturnal antihypertensive therapy in patients with coexistent neurogenic orthostatic hypotension and supine hypertension; and the prevalence, scope, and therapeutic requirements for managing neurogenic orthostatic hypotension that manifests with falls or cognitive impairment, but without postural lightheadedness or near syncope.

Longitudinal and postural changes of blood pressure predict dementia: the Malmö Preventive Project

The role of blood pressure (BP) changes in dementia is debatable. We aimed to analyse how resting and postural BP changes relate to incident dementia over a long-term follow-up. In the prospective population-based Malmö Preventive Project, 18,240 study participants (mean age: 45 ± 7 years, 63% male) were examined between 1974 and 1992 with resting and standing BP measurement, and re-examined between 2002 and 2006 at mean age of 68 ± 6 years with resting BP. A total of 428 participants (2.3%) were diagnosed with dementia through Dec 31, 2009. The association of resting and postural BP changes with risk of dementia was studied using multivariable-adjusted Cox regression models controlling for traditional risk factors. Diastolic BP (DBP) decrease on standing indicated higher risk of dementia [Hazard ratio (HR) per 10 mmHg: 1.22; 95% confidence interval (CI) 1.01-1.44, p = 0.036], which was mainly driven by increased risk in normotensive individuals. Higher systolic (SBP) and diastolic BP at re-examination was associated with lower risk of dementia (HR per 10 mmHg: 0.94; 95% CI 0.89-0.99, p = 0.011; and 0.87; 0.78-0.96, p = 0.006, respectively). Extreme decrease in SBP/DBP between baseline and re-examination (4th quartile; -7 ± 12/-15 ± 7 mmHg, respectively) indicated higher risk of dementia (HR 1.46; 95% CI 1.11-1.93, p = 0.008, and 1.54; 95% CI 1.14-2.08, p = 0.005; respectively) compared with reference group characterised by pronounced BP increase over the same period (1st quartile; +44 ± 13/+15 ± 7 mmHg). Diastolic BP decrease on standing in the middle age, decline in BP between middle-and advanced age, and lower BP in advanced age are independent risk factors of developing dementia.

Orthostatic Changes in Blood Pressure and Cognitive Status in the Elderly

We studied a cohort of 1408 older subjects to explore whether postural changes in blood pressure (BP; defined as orthostatic hypo- or hypertension) can predict the onset of cognitive deterioration. Orthostatic hypotension was defined as a drop of 20 mm Hg in systolic or 10 mm Hg in diastolic BP and orthostatic hypertension as a rise of 20 mm Hg in systolic BP. Orthostatic BP values were grouped into quintiles for secondary analyses. Two cognitive assessments were considered: (1) cognitive impairment, that is, Mini-Mental State Examination scores ≤24/30, and (2) cognitive decline (CD), that is, a 3-point decrease in Mini-Mental State Examination score from the baseline to the follow-up. At the baseline, the prevalence of orthostatic hypotension and hypertension was 18.3% and 10.9%, respectively. At the follow-up (4.4±1.2 years), 286 participants were found cognitively impaired and 138 had a CD. Using logistic regression analysis adjusted for potential baseline confounders, participants with orthostatic hypertension were at significantly higher risk of CD (odds ratio =1.50; 95% confidence intervals =1.26–1.78). Neither orthostatic hypotension nor orthostatic hypertension raised the risk of developing a cognitive impairment. Using quintiles of orthostatic BP values, we found that both decreases and increases in systolic and diastolic BP raised the risk of CD, but not of cognitive impairment. In conclusion, we found that orthostatic hypertension predicts the onset of CD, but not of cognitive impairment in the elderly, whereas orthostatic hypotension predicts neither of these conditions. Further studies are needed to confirm our findings.

Blood Pressure and Risk of Vascular Dementia: Evidence From a Primary Care Registry and a Cohort Study of Transient Ischemic Attack and Stroke

BACKGROUND AND PURPOSE

Vascular dementia is the second most common form of dementia but reliable evidence on age-specific associations between blood pressure (BP) and risk of vascular dementia is limited and some studies have reported negative associations at older ages.

METHODS

In a cohort of 4.28 million individuals, free of known vascular disease and dementia and identified from linked electronic primary care health records in the United Kingdom (Clinical Practice Research Datalink), we related BP to time to physician-diagnosed vascular dementia. We further determined associations between BP and dementia in a prospective population-based cohort of incident transient ischemic attack and stroke (Oxford Vascular Study).

RESULTS

For a median follow-up of 7.0 years, 11 114 initial presentations of vascular dementia were observed in the primary care cohort after exclusion of the first 4 years of follow-up. The association between usual systolic BP and risk of vascular dementia decreased with age (hazard ratio per 20 mm Hg higher systolic BP, 1.62; 95% confidence interval, 1.13-2.35 at 30-50 years; 1.26, 1.18-1.35 at 51-70 years; 0.97, 0.92-1.03 at 71-90 years; P trend=0.006). Usual systolic BP remained predictive of vascular dementia after accounting for effect mediation by stroke and transient ischemic attack. In the population-based cohort, prior systolic BP was predictive of 5-year risk of dementia with no evidence of negative association at older ages.

CONCLUSIONS

BP is positively associated with risk of vascular dementia, irrespective of preceding transient ischemic attack or stroke. Previous reports of inverse associations in old age could not be confirmed.

Neurocardiovascular Instability and Cognition

Neurocardiovascular instability (NCVI) refers to abnormal neural control of the cardiovascular system affecting blood pressure and heart rate behavior. Autonomic dysfunction and impaired cerebral autoregulation in aging contribute to this phenomenon characterized by hypotension and bradyarrhythmia. Ultimately, this increases the risk of falls and syncope in older people. NCVI is common in patients with neurodegenerative disorders including dementia. This review discusses the various syndromes that characterize NCVI icluding hypotension, carotid sinus hypersensitivity, postprandial hypotension and vasovagal syncope and how they may contribute to the aetiology of cognitive decline. Conversely, they may also be a consequence of a common neurodegenerative process. Regardless, recognition of their association is paramount in optimizing management of these patients.

Potential Interactions between the Autonomic Nervous System and Higher Level Functions in Neurological and Neuropsychiatric Conditions

The autonomic nervous system (ANS) maintains the internal homeostasis by continuously interacting with other brain structures. Its failure is commonly observed in many neurological and neuropsychiatric disorders, including neurodegenerative and vascular brain diseases, spinal cord injury, and peripheral neuropathies. Despite the different underlying pathophysiological mechanisms, ANS failure associates with various forms of higher level dysfunctions, and may also negatively impact on patients’ clinical outcome. In this review, we will discuss potential relationships between ANS and higher level dysfunctions in a selection of neurological and neuropsychiatric disorders. In particular, we will focus on the effect of a documented fall in blood pressure fulfilling the criteria for orthostatic hypotension and/or autonomic-reflex impairment on cognitive performances. Some evidence supports the hypothesis that cardiovascular autonomic failure may play a negative prognostic role in most neurological disorders. Despite a clear causal relationship between ANS involvement and higher level dysfunctions that is still controversial, this might have implications for neuro-rehabilitation strategies aimed at improving patients’ clinical outcome.

Pathogenesis and treatment of vascular cognitive impairment

SUMMARY 

Vascular cognitive impairment (VCI) defines a continuum of disorders ranging from mild cognitive impairment to full-blown dementia, attributable to cerebrovascular causes. Major morphological types – multi-infarct encephalopathy, strategic infarct type, subcortical arteriosclerotic leukoencephalopathy, multilacunar state, postischemic encephalopathy – result from systemic, cardiac and local large or small vessel disease. Cognitive decline is commonly caused by widespread small cerebrovascular lesions (CVLs) affecting regions/networks essential for cognition, memory and behavior. CVLs often coexist with Alzheimer-type and other pathologies, which interact in promoting dementia, but in many nondemented elderly individuals, mixed brain pathologies are also present. Due to the high variability of CVLs, no validated clinical and neuropathological criteria for VCI are available. Cholinesterase inhibitors and memantine produce small cognitive improvement but without essential effect. Antihypertensive treatment, cardiovascular control and lifestyle modifications reducing vascular risk factors are essential. Given its growing health, social and economic burden, prevention and treatment of VCI are a major challenge of neuroscience.

Orthostatic intolerance predicts mild cognitive impairment: incidence of mild cognitive impairment and dementia from the Swedish general population cohort Good Aging in Skåne

INTRODUCTION

Contradictory results have been reported on the relationship between orthostatic hypotension (OH) and mild cognitive impairment (MCI).

OBJECTIVE

To study the incidence of MCI and dementia and their relationship to OH and subclinical OH with orthostatic symptoms (orthostatic intolerance).

STUDY DESIGN AND SETTING

This study used a prospective general population cohort design and was based on data from the Swedish Good Aging in Skåne study (GÅS-SNAC), they were studied 6 years after baseline of the present study, with the same study protocol at baseline and at follow-up. The study sample comprised 1,480 randomly invited subjects aged 60 to 93 years, and had a participation rate of 82% at follow-up. OH test included assessment of blood pressure and symptoms of OH.

RESULTS

The 6-year incidence of MCI was 8%, increasing from 12.1 to 40.5 per 1,000 person-years for men and 6.9 to 16.9 per 1,000 person-years for women aged 60 to >80 years. The corresponding 6-year incidence of dementia was 8%. Orthostatic intolerance during uprising was related to risk for MCI at follow-up (odds ratio [OR] =1.84 [1.20-2.80][95% CI]), adjusted for age and education independently of blood pressure during testing. After stratification for hypertension (HT), the corresponding age-adjusted OR for MCI in the non-HT group was 1.71 (1.10-2.31) and 1.76 (1.11-2.13) in the HT group. Among controls, the proportion of those with OH was 16%; those with MCI 24%; and those with dementia 31% (age-adjusted OR 1.93 [1.19-3.14]).

CONCLUSION

Not only OH, but also symptoms of OH, seem to be a risk factor for cognitive decline and should be considered in the management of blood pressure among the elderly population.

Increased pulse pressure linked to dementia: further results from the Hypertension in the Very Elderly Trial - HYVET

OBJECTIVES

High blood pressure (BP) has been associated with increased risk of dementia. Concerns have been raised about lowering BP too far in the very elderly and thereby increasing risk. There is some evidence to suggest a potential 'J'-shaped relationship between DBP and risk of cognitive impairment. This was investigated using data from the HYpertension in the Very Elderly Trial (HYVET).

METHODS

HYVET was a double-blind, placebo-controlled trial of antihypertensives in patients aged at least 80 years with an untreated SBP of 160-199 mmHg. Active medication was indapamide sustained release 1.5 mg+/- perindopril 2-4 mg to reach goal pressure of less than 150/80 mmHg. Incident dementia was a secondary endpoint and was not significantly different between the two treatment groups. The relationship between pressure and incident dementia was assessed using Cox proportional hazards regression with BP entered as either a discrete (quartile analysis) or continuous predictor variable. Achieved BP was calculated as the mean of all pressures from the 9 month visit onwards.

RESULTS

During a mean follow-up of 2.2 years 263 incident cases of dementia were diagnosed. After adjustment for various covariates, baseline DBP was inversely related to incident dementia (P=0.0064). Achieved DBP did not predict later dementia in the placebo group (P=0.43), but showed a U-shaped relationship in the active treatment group (P=0.0195). The relationship between incident dementia and DBP did however not differ significantly between the placebo and active treatment groups (P=0.38). SBP was not associated with incident dementia, at baseline (P=0.62) or during follow-up (placebo group P=0.13, active group P=0.36). Wider achieved pulse pressure (PP) was associated with increased risk of dementia in both treatment groups (placebo P=0.032, active P=0.0046). The same tendency was observed for baseline PP (P=0.095).

CONCLUSION

Wider PP may possibly indicate an increased risk for dementia. Active treatment may act to change the shape of the relationship between DBP and dementia. Future studies need to focus on exploring the ideal goal pressure for this age group.

The evidence for treating hypertension in older people with dementia: a systematic review

Hypertension and dementia commonly co-exist in older people, yet guidance is lacking on how to manage these co-existing conditions. The aim of this systematic review was to assess the evidence for the treatment of hypertension in older people with dementia. Medline, EMBASE, Cochrane Library and the national research register archives were searched. Inclusion criteria were: randomised controlled trial of hypertension treatment, included participants aged 65+ years, participants had a diagnosis of dementia (global cognitive decline for at least 6 months affecting daily function), and the study assessed cognitive outcomes using validated tools. Dementia prevention studies and poor quality studies were excluded. The initial search revealed 1178 papers of potential interest, of which 24 were selected for review and six met the full inclusion criteria. Trials included people with mild-to-moderate but not severe dementia; exclusion criteria for the trials were extensive. Four trials were placebo-controlled RCTs; the remaining two compared different antihypertensives. All trials reported MMSE scores at baseline and follow-up; four reported blood pressure changes at follow-up; and only three reported cardiovascular morbidity or mortality at follow-up. Only one of four placebo-controlled studies showed evidence of blood pressure reduction, but no clear evidence for benefit (or harm) from antihypertensives on cognition, physical function or other cardiovascular outcomes. We found no evidence to confirm or refute the hypothesis that treatment of hypertension in people with dementia leads to overall health benefit.