Hypertension, cognitive decline, and dementia: an epidemiological perspective

Toll-Like Receptor 4-Mediated Neuroinflammation: Updates on Pathological Roles and Therapeutic Strategies in Chronic Cerebral Hypoperfusion

Neuroinflammation has been acknowledged as being one of the main pathologies that occur following chronic cerebral hypoperfusion (CCH). Since it significantly contributes to neuronal cell damage and thereby leads to cognitive impairment, the signals related to inflammation in hypoperfusion injury have been extensively investigated over the past few years. Toll-like receptor 4 (TLR4) is the key receptor responsible for immune and inflammatory reactions. It has been reported that TLR4 is involved in the pathology of several diseases and has emerged as a therapeutic target for developing a variety of anti-inflammatory compounds. This study explored the pathological roles of TLR4 that potentially cause the promotion of neuroinflammation in CCH damage. The evidence pertinent to the activation of TLR4 and its downstream inflammatory cascades following CCH are also summarized. This study also demonstrated the therapeutic potential of TLR4 inhibition, whether through drugs, substances, or other treatment strategies, in models of CCH-induced neurological dysfunction. The limitations of the accumulated evidence are addressed and discussed in this study. A deeper understanding of the roles of TLR4 in neuroinflammation following CCH damage may help inform the machinery behind pathological processes for advancing further neuroscientific research and developing therapeutic strategies for vascular dementia.

Elevated TGF-β1 impairs synaptic and cognitive function through activation of Smad2/3-Sp1 pathway in AngII-related hypertension

Vascular dementia (VaD) is characterized by cognitive decline due to reduced cerebral blood flow, although its molecular mechanisms remain unclear. This study shows that angiotensin II (AngII) elevates blood pressure, reduces hippocampal blood flow, and impairs synaptic and cognitive function, which correlates with increased TGF-β1 levels. Overexpressing TGF-β1 in rats induces similar deficits, while its downregulation partially mitigates these effects, with the exception of hypoperfusion. Phosphorylation of Smad2/3, downstream of TGF-β1, is elevated in AngII-treated rats and TGF-β1-exposed neurons, and inhibiting Smad2/3 activation prevents synaptic damage. Additionally, phosphorylated Smad2/3 interacts more with the transcription factor Sp1 in hippocampal neurons of AngII-treated rats. Overexpression of Sp1 worsens synaptic and cognitive function, whereas Sp1 knockdown improves TGF-β1-induced impairments. These findings highlight TGF-β1 as a key mediator of AngII-induced cognitive deficits, beyond hypoperfusion, suggesting that targeting the TGF-β1/Smad2/3/Sp1 axis may offer therapeutic benefits for hypertension-related synaptic and cognitive dysfunction.

Double product is longitudinally associated with reduced cognitive function in type 2 diabetes with insights from cross-lagged panel analysis and mediation by leucine-rich α-2-glycoprotein 1

BackgroundElevated systolic blood pressure (SBP) and resting heart rate (RHR) contribute to pathogenesis of diabetic complications. They increase inflammation which can upregulate leucine-rich α-2-glycoprotein 1 (LRG1), an emerging biomarker of cognitive decline.ObjectiveTo examine association between double product (DP, derived from multiplying SBP and RHR) and cognitive function in type 2 diabetes (T2D), with possible mediation by plasma LRG1.MethodsIn this prospective cohort of 1319 patients (mean age 62.5 ± 7.3), plasma LRG1 was measured with enzyme-linked immunosorbent assay. Cognitive function was assessed using Repeatable Battery for Assessment of Neuropsychological Status (RBANS). Cross-lagged panel analysis was done to examine temporal relationship between DP and cognitive function.ResultsBaseline DP was associated with lower baseline RBANS total score (adjusted coefficient = -2.43; 95%CI -4.76, -0.10; p = 0.041). 586 patients were followed up to 8.6 years. Baseline DP was associated with follow-up RBANS total score (adjusted coefficient = -3.80; 95%CI -6.51, -1.10; p = 0.006). It was also associated with lower follow-up RBANS scores in immediate memory and delayed memory with adjusted coefficients -4.38 (95%CI -8.49, -0.28; p = 0.036) and -5.12 (95%CI -9.88, -0.35; p = 0.035) respectively. In cross-lagged panel analysis, standardized effect size of baseline DP on follow-up RBANS total score (β = -0.08; p = 0.002) was larger than that of baseline RBANS total score on follow-up DP (β = -0.04; p = 0.266). LRG1 accounted for 14.7% of the association in mediation analysis (p = 0.035).ConclusionsDP was independently associated with cognitive function with possible mediation by LRG1. DP preceded decline in cognitive function. DP may be potential intervention and monitoring target for prevention of cognitive impairment and possibly Alzheimer's disease in T2D.

Endothelium-related biomarkers and cognitive decline in prevalent hemodialysis patients: A prospective cohort study

INTRODUCTION

Cognitive decline is prevalent in maintenance hemodialysis patients. The blood-brain barrier has been implicated in cognitive decline. In this prospective cohort study, we investigated the associations between endothelium-related biomarkers and steeper cognitive decline in this population.

METHODS

Cognitive function was assessed using the Portuguese-adapted Cambridge Cognitive Examination (CAMCOG) with items of the Mini-Mental State Examination (MMSE). Endothelium-related biomarkers included syndecan-1, ICAM-1, VCAM-1 and angiopoietin-2 (AGPT2). Patients were followed up for 4 years, and cognitive assessments were repeated. Multinomial regression analyses were performed to evaluate associations between biomarkers and cognitive decline.

RESULTS

A total of 216 patients completed the test battery at baseline. After 4 years, 102 patients had follow-up data. There was a significant decrease in cognitive function according to the CAMCOG and MMSE scores: a change of -0.39 (95% CI -0.27 to -0.51) and -0.51 (95% CI -0.27 to -0.76) standard deviation (SD) of the baseline scores. Additionally, executive function but not memory significantly decreased. Syndecan-1 level was independently associated with steeper cognitive decline; each increase in the SD of the syndecan-1 level was associated with a decrease in the CAMCOG of 0.20 (95% CI 0.07-0.33) SD from baseline. Syndecan-1 was associated with a steeper decline in MMSE score (β 0.54, 95% CI 0.28-0.81) and executive function (β 0.17, 95% CI 0.02-0.32). Syndecan-1 predicted severe cognitive impairment with an area under the curve for receiver operating characteristic curves of 0.75 (95% CI 0.64-0.83).

CONCLUSION

Our findings highlight the potential of syndecan-1, a biomarker of endothelium glycocalyx derangement, as a predictor of steeper cognitive decline in prevalent hemodialysis patients.

Peripheral vascular dysfunction and the aging brain

Aging is the greatest non-modifiable risk factor for most diseases, including cardiovascular diseases (CVD), which remain the leading cause of mortality worldwide. Robust evidence indicates that CVD are a strong determinant for reduced brain health and all-cause dementia with advancing age. CVD are also closely linked with peripheral and cerebral vascular dysfunction, common contributors to the development and progression of all types of dementia, that are largely driven by excessive levels of oxidative stress (e.g., reactive oxygen species [ROS]). Emerging evidence suggests that several fundamental aging mechanisms (e.g., "hallmarks" of aging), including chronic low-grade inflammation, mitochondrial dysfunction, cellular senescence and deregulated nutrient sensing contribute to excessive ROS production and are common to both peripheral and cerebral vascular dysfunction. Therefore, targeting these mechanisms to reduce ROS-related oxidative stress and improve peripheral and/or cerebral vascular function may be a promising strategy to reduce dementia risk with aging. Investigating how certain lifestyle strategies (e.g., aerobic exercise and diet modulation) and/or select pharmacological agents (natural and synthetic) intersect with aging "hallmarks" to promote peripheral and/or cerebral vascular health represent a viable option for reducing dementia risk with aging. Therefore, the primary purpose of this review is to explore mechanistic links among peripheral vascular dysfunction, cerebral vascular dysfunction, and reduced brain health with aging. Such insight and assessments of non-invasive measures of peripheral and cerebral vascular health with aging might provide a new approach for assessing dementia risk in older adults.

Frequency of Systemic Diseases and Oral Lesions Among the Institutionalized Elderly Subjects in the Northeast of Iran

Background

With ageing, the number of systemic diseases and the consumption of drugs increase. Moreover, some oral lesions, especially denture-related lesions, are commonly observed.

Aim and Objective

The purpose of this study was to determine the frequency of systemic diseases and oral lesions in the elderly in the Mashhad Geriatric Institutes.

Methods

Institutionalized elderly people, who could cooperate for oral examination, enrolled in this descriptive cross-sectional study. The frequency of oral lesions and their systemic diseases were recorded in the self-made checklist. For statistical analysis, Student's t-test and Chi-square test were utilized. The significance level was considered to be 0.05.

Results

During the study, 224 elderly subjects with a mean age of 75.63 ± 11.22 years were evaluated. The mean duration of residency in the elderly nursing centres was 1.87 ± 1.37 years. Hypertension, Alzheimer's disease and diabetes were the most common systemic diseases, and about 47% of the patients had two or multiple concurrent diseases. Among participants, 97.1% had at least one oral lesion. The most common oral lesions were fissured tongue (75%), sublingual varicosity (68.3%) and hairy or coated tongue (38.4%), respectively, which are classified as normal variations of oral mucosa. The most common pathological lesions were denture stomatitis, frictional keratosis and lichenoid reactions.

Conclusion

Regarding to the high frequency of oral lesions among ageing people, regular examination of the oral mucosa for early detection of oral lesions and appropriate treatments is recommended.

The association of cognition with protein energy wasting and synaptic transmission in chronic kidney disease

INTRODUCTION

In recent years, consciousness impairment in patients with end-stage renal disease (ESRD) has been paid more and more attention, but the cause and mechanism of consciousness state change is not clear.

METHODS

As the hippocampus played a crucial role in consciousness, we explored the pathological and electrophysiological changes in chronic kidney disease (CKD) mouse hippocampus.

RESULTS

Whole-cell recordings in hippocampal neurons showed that miniature excitatory postsynaptic current (mEPSC) frequency decreased, but the amplitude was unaltered in CKD_8w mice. In addition, α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor-mediated EPSCs (AMPAR-EPSCs) and N-methyl-D-aspartic acid receptor-mediated EPSCs (NMDAR-EPSCs) in hippocampal Schaffer collateral-CA1 synapses displayed a significant decline in CKD_8w mice. Although the ratio of AMPAR-/NMDAR-EPSCs did not change, the paired-pulse ratio (PPR) in CKD_8w mice increased. Intriguingly, the mEPSC frequency and AMPAR-/NMDAR-EPSCs amplitudes were positively associated with body weight, and the mEPSC frequency was negatively correlated with serum creatinine in CKD_8w mice, indicating a potential correlation between cognition and nutritional status in patients with CKD. To confirm the above hypothesis, we collected the clinical data from multiple hemodialysis centers to analyze the correlation between cognition and nutritional status.

CONCLUSION

Our analysis indicated that protein energy wasting (PEW) was a possible independent risk factor for consciousness dysfunction in maintenance hemodialysis (MHD) patients. Our results provided a more detailed mechanism underlying the cognitive impairment (CI) in ESRD patients at the synaptic level. Last but not least, our results showed that PEW was a probable new independent risk factor for CI in cases with ESRD.

Linking Cerebrovascular Dysfunction to Age-Related Hearing Loss and Alzheimer’s Disease—Are Systemic Approaches for Diagnosis and Therapy Required?

Alzheimer’s disease (AD), the most common cause of dementia in the elderly, is a neurodegenerative disorder associated with neurovascular dysfunction, cognitive decline, and the accumulation of amyloid β peptide (Aβ) in the brain and tau-related lesions in neurons termed neurofibrillary tangles (NFTs). Aβ deposits and NFT formation are the central pathological hallmarks in AD brains, and the majority of AD cases have been shown to exhibit a complex combination of systemic comorbidities. While AD is the foremost common cause of dementia in the elderly, age-related hearing loss (ARHL) is the most predominant sensory deficit in the elderly. During aging, chronic inflammation and resulting endothelial dysfunction have been described and might be key contributors to AD; we discuss an intriguing possible link between inner ear strial microvascular pathology and blood–brain barrier pathology and present ARHL as a potentially modifiable and treatable risk factor for AD development. We present compelling evidence that ARHL might well be seen as an important risk factor in AD development: progressive hearing impairment, leading to social isolation, and its comorbidities, such as frailty, falls, and late-onset depression, link ARHL with cognitive decline and increased risk of dementia, rendering it tempting to speculate that ARHL might be a potential common molecular and pathological trigger for AD. Additionally, one could speculate that amyloid-beta might damage the blood–labyrinth barrier as it does to the blood–brain barrier, leading to ARHL pathology. Finally, there are options for the treatment of ARHL by targeted neurotrophic factor supplementation to the cochlea to improve cognitive outcomes; they can also prevent AD development and AD-related comorbidity in the future.

Relationship Between Calcium Channel Blockers Therapy and Cognitive Function Improvement in Cognitive Decline Patients with Cerebrovascular Disease

INTRODUCTION

Amlodipine belongs to a class of calcium channel blockers that relax blood vessels to allow easier flow of blood. Higher blood pressure (BP) is associated with cerebrovascular disease and is an important contributor to cognitive decline and dementia.

AIM

This study aimed to evaluate the effect of 24 weeks of S-amlodipine besylate therapy on cognitive function in patients with hypertension and cerebrovascular disease.

METHODS

The data were obtained from a study of post-market surveillance of S-amlodipine besylate.

RESULTS

A total of 545 subjects (mean age 67 ± 9.68 years) with hypertension and ischemic cerebrovascular disease were enrolled. Patients with a baseline Mini-Mental State Examination (MMSE) score above 26 were assigned to the cognitive normal (CN) (n = 294) group, and those with MMSE score less than 26 were in the cognitive decline (CD) (n = 251) group. After 24 weeks of treatment with S-amlodipine besylate 5 mg, MMSE and Global Deterioration Scale (GDS) were evaluated again. Changes in MMSE were compared in the target BP reached (TBPR) and non-reached (NTBPR) groups and for CN and CD groups. Treatment with 5 mg of S-amlodipine besylate for 24 weeks improved MMSE and GDS scores (p < 0.001). The CD group showed improvement in MMSE score regardless of whether target BP was obtained (TBPR: p < 0.001, NTBPR: p < 0.01). However, the CN classification was not significant for either TBPR or NTBPR groups.

CONCLUSIONS

S-amlodipine besylate improved cognition of the CD group with hypertension and cerebrovascular disease regardless of obtaining target BP.

Cost of primary care approaches for hypertension management and risk-based cardiovascular disease prevention in Bangladesh: a HEARTS costing tool application

OBJECTIVE

To estimate the costs of scaling up the HEARTS pilot project for hypertension management and risk-based cardiovascular disease (CVD) prevention at the full population level in the four subdistricts (upazilas) in Bangladesh.

SETTINGS

Two intervention scenarios in subdistrict health complexes: hypertension management only, and risk-based integrated hypertension, diabetes, and cholesterol management.

DESIGN

Data obtained during July-August 2020 from subdistrict health complexes on the cost of medications, diagnostic materials, staff salaries and other programme components.

METHODS

Programme costs were assessed using the HEARTS costing tool, an Excel-based instrument to collect, track and evaluate the incremental annual costs of implementing the HEARTS programme from the health system perspective.

PRIMARY AND SECONDARY OUTCOME MEASURES

Programme cost, provider time.

RESULTS

The total annual cost for the hypertension control programme was estimated at US$3.2 million, equivalent to US$2.8 per capita or US$8.9 per eligible patient. The largest cost share (US$1.35 million; 43%) was attributed to the cost of medications, followed by the cost of provider time to administer treatment (38%). The total annual cost of the risk-based integrated management programme was projected at US$14.4 million, entailing US$12.9 per capita or US$40.2 per eligible patient. The estimated annual costs per patient treated with medications for hypertension, diabetes and cholesterol were US$18, US$29 and US$37, respectively.

CONCLUSION

Expanding the HEARTS hypertension management and CVD prevention programme to provide services to the entire eligible population in the catchment area may face constraints in physician capacity. A task-sharing model involving shifting of select tasks from doctors to nurses and local community health workers would be essential for the eventual scale-up of primary care services to prevent CVD in Bangladesh.

Diabetes, Hypertension, and the Risk of Dementia

BACKGROUND

Type 2 diabetes (T2D) and hypertension (HTN) are well-known modifiable risk factors for dementia, but their intricate attributes accounting for dementia development has not been clearly delineated.

OBJECTIVE

We conducted this study to investigate and compare the effects of T2D and HTN on dementia risk.

METHODS

We screened data of matched pairs of patients with T2D or HTN between January 1, 2000 and December 31, 2017 from Taiwan's National Health Insurance Research Database. Fine and Gray's subdistribution hazard models were used for calculating the risk of dementia.

RESULTS

Patients with T2D and subsequent HTN were associated with significantly higher risks of all-cause dementia (aHR 1.51, 95% CI 1.25-1.83) and vascular dementia (aHR 2.30, 95% CI 1.71-3.13) compared with those without subsequent HTN. Patients with HTN and subsequent T2D were associated with significantly higher risks of all-cause dementia (aHR 1.15, 95% CI 1.08-1.21), vascular dementia (aHR 1.25, 95% CI 1.62-1.34), and other dementia (aHR 1.31, 95% CI 1.03-1.66) compared with those without subsequent HTN. The subgroups of male and female patients, age of 50-69 and 70-90 years with subsequent comorbidity were associated with significantly higher risks of all-cause dementia and vascular dementia than those without subsequent comorbidity.

CONCLUSION

This nationwide cohort study demonstrated that patients with T2D and subsequent HTN had association with higher risks of all-cause dementia and vascular dementia, and those with HTN and subsequent T2D were associated with higher risks of all-cause dementia, vascular dementia, and other dementia.

Chronic Renin-Angiotensin System Activation Induced Neuroinflammation: Common Mechanisms Underlying Hypertension and Dementia?

Hypertension is a major risk factor for the pathogenesis of vascular dementia and Alzheimer's disease. Chronic activation of the renin-angiotensin system (RAS) contributes substantially to neuroinflammation. We propose that neuroinflammation arising from chronic RAS activation can initiate and potentiate the onset of hypertension and related dementia. Neuroinflammation induced by chronic activation of the RAS plays a key role in the pathogenesis of dementia. Increased levels of pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and transforming growth factor (TGF)-β have been reported in brain tissue of vascular dementia patients and animal models of vascular dementia induced by either angiotensin II infusion or transverse aortic coarctation. It is proposed that neuronal cell death and synaptic dysfunction induced by neuroinflammation lead to cognitive impairment in dementia. The neuroprotective RAS pathway, regulated by angiotensin-converting enzyme 2 (ACE2) which converts angiotensin II into angiotensin-(1-7), can attenuate hypertension and dementia. Furthermore, the use of anti-hypertensive medications in preventing dementia or cognitive decline in hypertensive patients and animal models of dementia have mostly been beneficial. Current evidence suggests a strong link between RAS induced neuroinflammation and the onset of hypertension and dementia, which warrants further investigation. Strategies to counteract an overactive RAS and enhance the neuroprotective arm of the RAS may help prevent or improve cognitive impairment associated with hypertension.

The Conspicuous Link between Ear, Brain and Heart-Could Neurotrophin-Treatment of Age-Related Hearing Loss Help Prevent Alzheimer's Disease and Associated Amyloid Cardiomyopathy?

Alzheimer's disease (AD), the most common cause of dementia in the elderly, is a neurodegenerative disorder associated with neurovascular dysfunction and cognitive decline. While the deposition of amyloid β peptide (Aβ) and the formation of neurofibrillary tangles (NFTs) are the pathological hallmarks of AD-affected brains, the majority of cases exhibits a combination of comorbidities that ultimately lead to multi-organ failure. Of particular interest, it can be demonstrated that Aβ pathology is present in the hearts of patients with AD, while the formation of NFT in the auditory system can be detected much earlier than the onset of symptoms. Progressive hearing impairment may beget social isolation and accelerate cognitive decline and increase the risk of developing dementia. The current review discusses the concept of a brain-ear-heart axis by which Aβ and NFT inhibition could be achieved through targeted supplementation of neurotrophic factors to the cochlea and the brain. Such amyloid inhibition might also indirectly affect amyloid accumulation in the heart, thus reducing the risk of developing AD-associated amyloid cardiomyopathy and cardiovascular disease.

Systemic Candesartan Treatment Modulates Behavior, Synaptic Protein Levels, and Neuroinflammation in Female Mice That Express Human APOE4

Evidence suggests that angiotensin receptor blockers (ARBs) could be beneficial for Alzheimer’s disease (AD) patients independent of any effects on hypertension. However, studies in rodent models directly testing the activity of ARB treatment on behavior and AD-relevent pathology including neuroinflammation, Aβ levels, and cerebrovascular function, have produced mixed results. APOE4 is a major genetic risk factor for AD and has been linked to many of the same functions as those purported to be modulated by ARB treatment. Therefore, evaluating the effects of ARB treatment on behavior and AD-relevant pathology in mice that express human APOE4 could provide important information on whether to further develop ARBs for AD therapy. In this study, we treated female and male mice that express the human APOE4 gene in the absence (E4FAD−) or presence (E4FAD+) of high Aβ levels with the ARB prodrug candesartan cilexetil for a duration of 4 months. Compared to vehicle, candesartan treatment resulted in greater memory-relevant behavior and higher hippocampal presynaptic protein levels in female, but not male, E4FAD− and E4FAD+ mice. The beneficial effects of candesartan in female E4FAD− and E4FAD+ mice occurred in tandem with lower GFAP and Iba1 levels in the hippocampus, whereas there were no effects on markers of cerebrovascular function and Aβ levels. Collectively, these data imply that the effects of ARBs on AD-relevant pathology may be modulated in part by the interaction between APOE genotype and biological sex. Thus, the further development of ARBs could provide therapeutic options for targeting neuroinflammation in female APOE4 carriers.

Risk of dementia and death in very-late-onset schizophrenia-like psychosis: A national cohort study

Knowledge is limited regarding the risks of death and dementia in very-late onset schizophrenia-like psychosis (VLOS). This study aims to scrutinize the associations between VLOS with the risks of death and dementia. Based on a prospective Israeli cohort study with national coverage, 94,120 persons without dementia or schizophrenia diagnoses aged 60 to 90 in 2012 were followed-up for the risks of dementia or death from 2013 to 2017. VLOS was classified as present from the age of the first ICD-9 diagnosis during follow-up, otherwise as absent. Hazard ratios (HR) with confidence intervals (95% CI) were computed with survival models to quantify the associations between VLOS and the risks of death and dementia, without and with adjustment for confounding. Nine sensitivity analyses were computed to examine the robustness of the results. The group with VLOS, compared to the group without, had higher death (n = 61, 18.5% vs. n = 7028, 7.5%, respectively) and dementia (n = 64, 19.5% vs. n = 5962, 6.4%, respectively) rates. In the primary analysis, the group with VLOS compared to the group without had increased risks of death (unadjusted HR = 3.10, 95% CI = 2.36, 4.06, P < .001; adjusted HR = 2.89, 95% CI = 2.15, 3.89; P < .001) and dementia (unadjusted HR = 3.81, 95% CI = 2.90, 4.99, P < .001; adjusted HR = 2.67, 95% CI = 1.82, 3.91; P < .001). The results remained statistically significant (P < .05) in all sensitivity analyses, including among persons without antipsychotic medication. The results may support notions of increased dementia risk and accelerated aging in VLOS, or that VLOS is a prodromal state of dementia.

Sleep, brain vascular health and ageing

Sleep maintains the function of the entire body through homeostasis. Chronic sleep deprivation (CSD) is a prime health concern in the modern world. Previous reports have shown that CSD has profound negative effects on brain vasculature at both the cellular and molecular levels, and that this is a major cause of cognitive dysfunction and early vascular ageing. However, correlations among sleep deprivation (SD), brain vascular changes and ageing have barely been looked into. This review attempts to correlate the alterations in the levels of major neurotransmitters (acetylcholine, adrenaline, GABA and glutamate) and signalling molecules (Sirt1, PGC1α, FOXO, P66^shc, PARP1) in SD and changes in brain vasculature, cognitive dysfunction and early ageing. It also aims to connect SD-induced loss in the number of dendritic spines and their effects on alterations in synaptic plasticity, cognitive disabilities and early vascular ageing based on data available in scientific literature. To the best of our knowledge, this is the first article providing a pathophysiological basis to link SD to brain vascular ageing.

Hypertension prevalence and its trend in Bangladesh: evidence from a systematic review and meta-analysis

BACKGROUND

Hypertension, itself being a major chronic condition, is one of the most significant risk factors for premature cardiovascular diseases and mortality. Hypertension is responsible for 13% of global deaths and three-quarters of the world's hypertensive population reside in low- and middle-income countries. Bangladesh is one of those countries that experiencing an epidemiological transition from communicable to non-communicable diseases, a nutritional transition from a traditional diet to process and fast food, and an increase in a sedentary lifestyle, resulting in increased hypertension prevalence. We carried out a systematic review and meta-analysis to identify existing research on hypertension prevalence in Bangladesh, summarize findings and assess its temporal change.

METHODS

We searched MEDLINE, EMBASE and PubMed and relevant references to identify studies on the prevalence of hypertension in Bangladesh. We used Random-effects meta-analysis to pool the prevalence estimates and performed subgroup analyses. We assessed heterogeneity, a trend in prevalence of hypertension and publication bias in selected studies.

RESULTS

Our search initially identified 735 articles and after removing duplicates, reviewing titles and abstracts, and screening full texts, 53 studies were finally selected. The studies comprised 305,432 subjects and reported overall, gender-specific, geographical location specific and criteria specific prevalence of hypertension. We identified the range of hypertension prevalence is from 1.10% to 75.0% and the overall weighted pooled prevalence of hypertension is 20.0%. An extremely high heterogeneity (I2 = 99.53%; Cochran Q-statistic p < 0.001) was observed in the prevalence of hypertension. Consequently, we performed subgroup analysis based on gender, age group and geographical location of the study participants, the cut-off level used to define hypertension, and the types of hypertension reported and presented our findings accordingly. An overall increasing trend of hypertension prevalence is also observed.

CONCLUSIONS

The prevalence of hypertension is high and rising in Bangladesh. Strategies targeting prevention are required to mitigate a further increase in the prevalence and reduce the morbidity and mortality associated with it.

High blood pressure in dementia: How low can we go?

Hypertension is an important public health concern. The prevalence keeps increasing, and it is a risk factor for several adverse health outcomes including a decline in cognitive function. Recent data also show that the prevalence of hypertension and age-related dementia is rising in Asian countries, including in the oldest old group. This study aims to discuss possible treatments for high blood pressure in the elderly and propose an optimal target for BP relative to cognitive outcomes. This review discusses several studies on related blood pressure treatments that remain controversial and the consequences if the treatment target is too low or aggressive. Longitudinal, cross-sectional, and RCT studies were included in this review. An optimum systolic blood pressure of 120-130 mm Hg is recommended, especially in nondiabetic hypertensive patients with significant risk factors. In the oldest old group of patients, hypertension might have a protective effect. The use of calcium channel blockers (CCB) and angiotensin receptor blocker (ARB) is independently associated with a decreased risk of dementia in older people. However, personalized care for patients with hypertension, especially for patients who are frail or very old, is encouraged.

Unsupervised machine learning for the discovery of latent disease clusters and patient subgroups using electronic health records

Machine learning has become ubiquitous and a key technology on mining electronic health records (EHRs) for facilitating clinical research and practice. Unsupervised machine learning, as opposed to supervised learning, has shown promise in identifying novel patterns and relations from EHRs without using human created labels. In this paper, we investigate the application of unsupervised machine learning models in discovering latent disease clusters and patient subgroups based on EHRs. We utilized Latent Dirichlet Allocation (LDA), a generative probabilistic model, and proposed a novel model named Poisson Dirichlet Model (PDM), which extends the LDA approach using a Poisson distribution to model patients' disease diagnoses and to alleviate age and sex factors by considering both observed and expected observations. In the empirical experiments, we evaluated LDA and PDM on three patient cohorts, namely Osteoporosis, Delirium/Dementia, and Chronic Obstructive Pulmonary Disease (COPD)/Bronchiectasis Cohorts, with their EHR data retrieved from the Rochester Epidemiology Project (REP) medical records linkage system, for the discovery of latent disease clusters and patient subgroups. We compared the effectiveness of LDA and PDM in identifying disease clusters through the visualization of disease representations. We tested the performance of LDA and PDM in differentiating patient subgroups through survival analysis, as well as statistical analysis of demographics and Elixhauser Comorbidity Index (ECI) scores in those subgroups. The experimental results show that the proposed PDM could effectively identify distinguished disease clusters based on the latent patterns hidden in the EHR data by alleviating the impact of age and sex, and that LDA could stratify patients into differentiable subgroups with larger p-values than PDM. However, those subgroups identified by LDA are highly associated with patients' age and sex. The subgroups discovered by PDM might imply the underlying patterns of diseases of greater interest in epidemiology research due to the alleviation of age and sex. Both unsupervised machine learning approaches could be leveraged to discover patient subgroups using EHRs but with different foci.

Neurovascular unit dysregulation, white matter disease, and executive dysfunction: the shared triad of vascular cognitive impairment and Alzheimer disease

Executive dysfunction is the most important predictor for loss of independence in dementia. As executive function involves the coordination of distributed cerebral functions, executive function requires healthy white matter. However, white matter is highly vulnerable to cerebrovascular insults, with executive dysfunction being a core feature of vascular cognitive impairment (VCI). At the same time, cerebrovascular pathology, white matter disease, and executive dysfunction are all increasingly recognized as features of Alzheimer disease (AD). Recent studies have characterized the crucial role of glial cells in the pathological changes observed in both VCI and AD. In comorbid VCI and AD, the glial cells of the neurovascular unit (NVU) emerge as important therapeutic targets for the preservation of white matter integrity and executive function. Our synthesis from current research identifies dysregulation of the NVU, white matter disease, and executive dysfunction as a fundamental triad that is common to both VCI and AD. Further study of this triad will be critical for advancing the prevention and management of dementia.

Elevated cerebrospinal fluid sodium in hypertensive human subjects with a family history of Alzheimer's disease

High salt (sodium) intake leads to the development of hypertension despite the fact that plasma sodium concentration ([Na⁺]) is usually normal in hypertensive human patients. Increased cerebrospinal fluid (CSF) sodium contributes to elevated sympathetic activity and high blood pressure (BP) in rodent models of hypertension. However, whether there is an increased accumulation of sodium in the CSF of humans with chronic hypertension is not well defined. Here, we investigated CSF [Na⁺] from hypertensive and normotensive human subjects with family histories of Alzheimer's disease in samples collected in a clinical trial, as spinal tap is not a routine clinical procedure for hypertensive patients. The [Na⁺] and osmolality in plasma and CSF were measured by flame photometry. Daytime ambulatory BP was monitored while individuals were awake. Participants were deidentified and data were analyzed in conjunction with a retrospective analysis of patient history and diagnosis. We found that CSF [Na⁺] was significantly higher in participants with high BP compared with normotensive participants; there was no difference in plasma [Na⁺], or plasma and CSF osmolality between groups. Subsequent multiple linear regression analyses controlling for age, sex, race, and body mass index revealed a significant positive correlation between CSF [Na⁺] and BP but showed no correlation between plasma [Na⁺] and BP. In sum, CSF [Na⁺] was higher in chronic hypertensive individuals and may play a key role in the pathogenesis of human hypertension. Collectively, our findings provide evidence for the clinical significance of CSF [Na⁺] in chronic hypertension in humans.

Roles of vascular risk factors in the pathogenesis of dementia

The number of people with dementia is rapidly growing along with the aging of society and is becoming a social issue worldwide. The results of recent clinical and basic studies have suggested that vascular risk factors, such as hypertension and diabetes mellitus, affect the pathogenesis of dementia. Cerebrovascular damage due to vascular risk factors directly triggers vascular dementia, and it is becoming more apparent that vascular risk factors also increase the risk of neurodegenerative Alzheimer's disease, which is associated with the accumulation of neurotoxic proteins in the brain. Although disease-modifying therapy for dementia has not yet been established, several studies have shown that the management of vascular risk factors could possibly contribute to reducing the risk of developing dementia, thus making them important targets for dementia prevention. In this article, we review recent findings regarding the relationship between vascular risk factors and dementia, especially focusing on Alzheimer's disease, the underlying molecular mechanisms, and the potential strategies targeting these modifiable risk factors to prevent cognitive decline.

The comparison of cognitive function and risk of dementia in CKD patients under peritoneal dialysis and hemodialysis: A PRISMA-compliant systematic review and meta-analysis

BACKGROUNDS

Cognitive functions (CF) decline has been reported in end-stage renal disease (ESRD) patients. However, the influence of dialysis modalities on CF has not been investigated systematically.

METHODS

A systematic literature search was conducted in MEDLINE, Embase, Cochrane library and unpublished database Clinicaltrials.gov to identify the studies comparing the cognitive functions or risk of dementia between hemodialysis (HD) and peritoneal dialysis (PD). After data extraction, quality of studies was assessed using the Newcastle-Ottawa scale. Both qualitative and quantitative analyses were performed.

RESULTS

After study inclusion, totally 15 cohort or cross-sectional studies were included, comparing the cognitive functions using neuropsychological tests and covering the executive function, memory, orientation, attention, etc. By qualitative analysis, it showed that more studies are inclined to PD compared with HD with better cognitive functions. By quantitative analysis, it showed that PD showed better performance in the tests of Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), stroop interference test and exhibited lower risk of dementia compared with HD.

CONCLUSIONS

In this meta-analysis, we draw preliminary conclusion that patients treated with PD had better cognitive functions and lower dementia risk compared with patients with HD. Still more large-scale and well-conducted prospective cohort studies are needed to draw more convincing conclusions.

Cerebral Aβ40 and systemic hypertension

Mid-life hypertension and cerebral hypoperfusion may be preclinical abnormalities in people who later develop Alzheimer's disease. Although accumulation of amyloid-beta (Aβ) is characteristic of Alzheimer's disease and is associated with upregulation of the vasoconstrictor peptide endothelin-1 within the brain, it is unclear how this affects systemic arterial pressure. We have investigated whether infusion of Aβ₄₀ into ventricular cerebrospinal fluid modulates blood pressure in the Dahl salt-sensitive rat. The Dahl salt-sensitive rat develops hypertension if given a high-salt diet. Intracerebroventricular infusion of Aβ induced a progressive rise in blood pressure in rats with pre-existing hypertension produced by a high-salt diet ( p < 0.0001), but no change in blood pressure in normotensive rats. The elevation in arterial pressure in high-salt rats was associated with an increase in low frequency spectral density in systolic blood pressure, suggesting autonomic imbalance, and reduced cardiac baroreflex gain. Our results demonstrate the potential for intracerebral Aβ to exacerbate hypertension, through modulation of autonomic activity. Present findings raise the possibility that mid-life hypertension in people who subsequently develop Alzheimer's disease may in some cases be a physiological response to reduced cerebral perfusion complicating the accumulation of Aβ within the brain.

Molecular Basis of the Brain Renin Angiotensin System in Cardiovascular and Neurologic Disorders: Uncovering a Key Role for the Astroglial Angiotensin Type 1 Receptor AT1R

The central renin angiotensin system (RAS) is one of the most widely investigated cardiovascular systems in the brain. It is implicated in a myriad of cardiovascular diseases. However, studies from the last decade have identified its involvement in several neurologic abnormalities. Understanding the molecular functionality of the various RAS components can thus provide considerable insight into the phenotypic differences and mechanistic drivers of not just cardiovascular but also neurologic disorders. Since activation of one of its primary receptors, the angiotensin type 1 receptor (AT1R), results in an augmentation of oxidative stress and inflammatory cytokines, it becomes essential to investigate not just neuronal RAS but glial RAS as well. Glial cells are key homeostatic regulators in the brain and are critical players in the resolution of overt oxidative stress and neuroinflammation. Designing better and effective therapeutic strategies that target the brain RAS could well hinge on understanding the molecular basis of both neuronal and glial RAS. This review provides a comprehensive overview of the major studies that have investigated the mechanisms and regulation of the brain RAS, and it also provides insight into the potential role of glial AT1Rs in the pathophysiology of cardiovascular and neurologic disorders.

Tannins Enriched Fraction of Emblica officinalis Fruits Alleviates High-Salt and Cholesterol Diet-Induced Cognitive Impairment in Rats via Nrf2-ARE Pathway

Modern diets containing high quantities of salt and cholesterol have exhibited to cause a considerable effect on our health. Such diets, when consumed in the long term, have also shown to be a precursor to several disorders such as the metabolic disorder and consequently, various other diseases, including cognitive deficits. In the present study, we used a high salt and cholesterol diet (HSCD) to induce cognitive impairment in rats and also investigated the pharmacological action of tannins enriched fractions of Emblica officinalis (EOT) - a fruit that has been traditionally used for the treatment of numerous disorders for centuries. Significant alterations in MDA, GSH, TBARS, GPx, mitochondrial ATP, and mitochondrial membrane potential levels were observed in rats fed HSCD, which indicated presence of oxidative stress. Moreover, classic signs of cognitive impairment and deficits in spatial learning and memory were observed in the neurobehavioral tests. E. officinalis tannins exhibited good affinity to Nrf2 receptors in in silico studies, significantly reversed the changes in the aforementioned biomarkers of oxidative stress which were altered in the model group, as well as improved the performance of rats in Morris water maze task. Our results also reflected that EOT supplementation significantly increased the expression of Nrf2 in the CA1 region of hippocampus and cortex. Additionally, TUNEL assay indicated that EOT supplementation led to reversal of DNA fragmentation and apoptosis caused by HSCD. Immunohistochemical analysis and western blot further revealed a surge in the nuclear location of Nrf2. Through our study, we have demonstrated that cognitive impairment can be caused in rats via HSCD as a result of the oxidative stress induced by the same. Additionally, we have investigated a novel mechanism of action for EOT (which strongly suggests to be via the Nrf2-ARE pathway) and demonstrated that it has the potential to be used in the treatment of cognitive impairment.

Peripheral and Cerebral Resistance Arteries in the Spontaneously Hypertensive Heart Failure Rat: Effects of Stilbenoid Polyphenols

Hypertension is associated with aberrant structure and mechanical properties of resistance arteries. We determined the effects of resveratrol, a non-flavonoid polyphenol found in foods such as red grapes, and structurally-similar analogues (pterostilbene and gnetol) on systolic blood pressure (SBP) and resistance arteries from the spontaneously hypertensive heart failure (SHHF) rat. SBP was elevated in 17-week-old SHHF vs. Sprague-Dawley rats (normotensive control; 194 ± 3 vs. 142 ± 6 mmHg, p < 0.01) and was unaffected by resveratrol, pterostilbene, or gnetol (2.5 mg/kg/d). Geometry and mechanical properties of pressurized mesenteric resistance arteries and middle cerebral arteries were calculated from media and lumen dimensions measured at incremental intraluminal pressures. SHHF arteries exhibited remodeling which consisted of augmented media-to-lumen ratios, and this was attenuated by stilbenoid treatment. Compliance was significantly reduced in SHHF middle cerebral arteries but not mesenteric arteries vis-à-vis increased wall component stiffness; stilbenoid treatment failed to normalize compliance and wall component stiffness. Our data suggest that neither AMPK nor ERK mediate stilbenoid effects. In conclusion, we observed arterial bed-specific abnormalities, where mesenteric resistance arteries exhibited remodeling and cerebral arteries exhibited remodeling and stiffening. Resveratrol, pterostilbene, and gnetol exhibited similar abilities to attenuate vascular alterations.

The blood brain barrier in Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia, affecting millions of people worldwide. One of the prominent causative factors of AD pathogenesis is cerebral vascular dysfunction, which results in diminished cerebral perfusion. Moreover, due to the loss of the protective function of the blood-brain barrier (BBB), impaired clearance of excess neurotoxic amyloid beta (Aβ) occurs, causing vascular perturbation and diminished cognitive functioning. The relationship between the prevalence of AD and vascular risk factors is complex and not fully understood. In this review we illustrate the vascular risk factors, their effects on BBB function and their contributions to the onset of AD. Additionally, we discuss the underlying factors that may lead to altered neurovascular function and/or cerebral hypoperfusion in AD.

Association between dialysis treatment and cognitive decline: A study from the Project in Sado for Total Health (PROST), Japan

AIM

Evidence for the association between dialysis treatment and cognitive decline is limited. The present study aimed to determine whether dialysis treatment is associated with cognitive decline in adult outpatients of a general hospital in Japan.

METHODS

This was a cross-sectional substudy of the Project in Sado for Total Health (PROST). Total Health PROST targeted adult outpatients of a general hospital in Sado City, Niigata, Japan. Among 753 patients (mean age 68.1 ± 11.6 years) analyzed, 66 received dialysis. Cognitive state was evaluated using the Mini-Mental State Examination, and those with a Mini-Mental State Examination score <24 were considered "cognitively declined." The prevalence of cognitive decline was compared by odds ratios calculated with multiple logistic regression analysis. Variables included in the analyses were dialysis, age, sex and self-reported histories of hypertension, diabetes, stroke and ischemic heart disease.

RESULTS

Of the 66 dialysis patients, 24 (36.4%) showed cognitive decline, whereas 172 (25.0%) of 687 non-dialysis patients showed cognitive decline. The age and sex-adjusted odds ratio for cognitive decline in dialysis patients was 2.57 (95% confidence interval 1.43-4.61), relative to non-dialysis patients. The odds ratio remained significant (odds ratio 2.69, 95% confidence interval 1.49-4.88) even after adjusting for all covariates.

CONCLUSION

The prevalence of cognitive decline was high in dialysis patients relative to non-dialysis patients among outpatients of a general hospital in Japan. Geriatr Gerontol Int 2017; 17: 1584-1587.

Cognition in People With End-Stage Kidney Disease Treated With Hemodialysis: A Systematic Review and Meta-analysis

BACKGROUND

Cognitive impairment is associated with poorer quality of life, risk for hospitalization, and mortality. Cognitive impairment is common in people with end-stage kidney disease treated with hemodialysis, yet the severity and specific cognitive deficits are uncertain.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING & POPULATION

Adults receiving hemodialysis compared with the general population, people with non-dialysis-dependent chronic kidney disease (NDD-CKD), people receiving peritoneal dialysis, or people with nondialyzed chronic kidney failure.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials, cohort or cross-sectional studies without language restriction.

INDEX TESTS

Validated neuropsychological tests of cognition.

OUTCOMES

Cognitive test scores, aggregated by cognitive domain: orientation and attention, perception, memory, language, construction and motor performance, concept formation and reasoning, and executive functions.

RESULTS

42 studies of 3,522 participants. Studies were of high or uncertain risk of bias, assessed by the Newcastle-Ottawa Scale. People treated with hemodialysis had worse cognition than the general population, particularly in attention (n=22; standardized mean difference [SMD], -0.93; 95% CI, -1.18 to -0.68). Hemodialysis patients performed better than nondialyzed patients with chronic kidney failure in attention (n=6; SMD, 0.70; 95% CI, 0.45 to 0.96) and memory (n=6; SMD, 0.36; 95% CI, 0.08 to 0.63), but had poorer memory than the general population (n=16; SMD, -0.41; 95% CI, -0.91 to 0.09) and people with NDD-CKD (n=5; SMD, -0.40; 95% CI, -0.60 to -0.21). There were insufficient data to show other differences among people receiving hemodialysis and those receiving peritoneal dialysis or with NDD-CKD.

LIMITATIONS

Potentially biased studies, not wholly adjusted for education. High heterogeneity, mainly due to the large variety of tests used to assess cognition.

CONCLUSIONS

People treated with hemodialysis have impaired cognitive function compared to the general population, particularly in the domains of orientation and attention and executive function. Cognitive deficits in specific domains should be further explored in this population and should be considered when approaching education and chronic disease management.

Serum Levels of ApoA1 and ApoA2 Are Associated with Cognitive Status in Older Men

Background. Advancing age, chronic inflammation, oxidative damage, and disorders of lipid metabolism are positively linked to the late-life cognitive impairment. Serum biomarkers may be associated with the cognitive status in older men. Methods. 440 old male subjects with different cognitive functions were recruited to investigate probable serum markers. Pearson Chi-Squared test, univariate analysis, and multivariate logistic regression analysis were performed to evaluate biomarkers which may be associated with cognitive status. Results. Levels of fundus atherosclerosis (AS) (P < 0.001), age (P < 0.001), serum biomarkers peroxidase (POD) (P = 0.026) and interleukin-6 (IL-6) (P = 0.001), serum levels of high-density lipoprotein cholesterol (HDL-C) (P < 0.001), apolipoprotein A2 (ApoA2) (P = 0.001), and ApoC2 (P = 0.005) showed significant differences. Compared to group 3, ApoA1 in group 1 (OR = 1.30, 95% CI 1.01–1.67) and group 2 (OR = 1.47, 95% CI 1.11–1.94) were higher, while ApoA2 were lower (group 1: OR = 0.43, 95% CI 0.18–1.02; group 2: OR = 0.21, 95% CI 0.08–0.54) after adjusting for control variables. Conclusion. The results demonstrated that age, AS levels, POD, IL-6, HDL-C, ApoA2, and ApoC2 were significantly related to cognitive status. Moreover, ApoA1 and ApoA2 were independently associated with cognitive impairment and late-life dementia.

The increased potassium intake improves cognitive performance and attenuates histopathological markers in a model of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by hallmarks that include an accumulation of amyloid-β peptide (Aβ), inflammation, oxidative stress and synaptic dysfunction, which lead to a decrease in cognitive function. To date, the onset and progression of AD have been associated with pathologies such as hypertension and diabetes. Hypertension, a disease with a high incidence worldwide, is characterized by a chronic increase in blood pressure. Interestingly, this disease has a close relationship to the eating behavior of patients because high Na(+) intake is a significant risk factor for hypertension. In fact, a decrease in Na(+) consumption, along with an increase in K(+) intake, is a primary non-pharmacological approach to preventing hypertension. In the present work, we examined whether an increase in K(+) intake affects the expression of certain neuropathological markers or the cognitive performance of a murine model of AD. We observed that an increase in K(+) intake leads to a change in the aggregation pattern of the Aβ peptide, a partial decrease in some epitopes of tau phosphorylation and improvement in the cognitive performance. The recovery in cognitive performance was correlated with a significant improvement in the generation of long-term potentiation. We also observed a decrease in markers related to inflammation and oxidative stress such as glial fibrillary acidic protein (GFAP), interleukin 6 (IL-6) and 4-hydroxynonenal (4-HNE). Together, our data support the idea that changes in diet, such as an increase in K(+) intake, may be important in the prevention of AD onset as a non-pharmacological therapy.

Hypertension exacerbates predisposition to neurodegeneration and memory impairment in the presence of a neuroinflammatory stimulus: Protection by angiotensin converting enzyme inhibition

Hypertension is a risk factor for cognitive impairment. Furthermore, neuroinflammation and neurodegeneration are intricately associated with memory impairment. Therefore, the present study aimed to explore the involvement of hypertension and angiotensin system in neurodegeneration and memory dysfunction in the presence of neuroinflammatory stimulus. Memory impairment was induced by chronic neuroinflammation that was developed by repeated intracerebroventricular (ICV) injections of lipopolysaccharide (LPS) on the 1st, 4th, 7th, and 10th day. Memory functions were evaluated by the Morris water maze (MWM) test on days 13-15, followed by biochemical and molecular studies in the cortex and hippocampus regions of rat brain. LPS at the dose of 25μg ICV caused memory impairment in spontaneously hypertensive rats (SHRs) but not in normotensive Wistar rats (NWRs). Memory deficit was obtained with 50μg of LPS (ICV) in NWRs. Control SHRs already exhibited increased angiotensin converting enzyme (ACE) activity and expression, neuroinflammation (increased TNF-α, GFAP, COX-2 and NF-kB), oxidative stress (increased iNOS, ROS and nitrite levels), TLR-4 expression and TUNEL positive cells as compared to control NWRs. Further, LPS (25μg ICV) exaggerated inflammatory response, oxidative stress and apoptosis in SHRs but similar effects were witnessed at 50μg of LPS (ICV) in NWRs. Oral administration of perindopril (ACE inhibitor), at non-antihypertensive dose (0.1mg/kg), for 15days attenuated LPS induced deleterious changes in both NWRs and SHRs. Our data suggest that susceptibility of the brain for neurodegeneration and memory impairment induced by neuroinflammation is enhanced in hypertension, and that can be protected by ACE inhibition.

Cognitive function and associated factors among older people in Taiwan: age and sex differences

PURPOSE

The aim of this study was to examine cognitive function and the risk and the protective factors by age and sex among Taiwanese older people.

METHODS

The data were from a nation-representative panel of older people in Taiwan. The participants completing both the 2003 and 2007 waves were included for analysis in this study (n=3228). Descriptive analysis and generalized linear model were applied, and the samples were stratified by age groups and by sex.

RESULTS

The factors related to higher cognitive function at the intercept included being younger, male, higher education, and doing unpaid work. At the time slope, the age effect and physical function difficulties would reduce the cognitive function across time, while education and providing informational support would increase the cognitive function across time. There were age- and sex-differences in the factors related to cognitive function, particularly on the working status and social participation.

CONCLUSION

Different health promotion strategies to target these populations should be accordingly developed.

Current readings: neurocognitive impairment and clinical implications after cardiac surgery

The earliest reports of cardiac surgery literatures reported evidence of neurocognitive decline, highlighted in the 1995 statement of Consensus on assessment of neurobehavioral outcomes after cardiac surgery. Until now, the magnitude and clinical importance of neurocognitive outcomes continues to fluctuate and lack clarity. The aim of this review is to evaluate the contemporary status of neurocognitive outcomes in relation to pre-existing impairment, revascularization strategy, broader cardiovascular pathophysiological processes, and any longer-term clinical implications. Five studies published between 2009 and 2013 were reviewed. A meta-analysis did not find differences between on- and off-pump procedures. In other studies, there was evidence for extensive preoperative neurocognitive impairments. Additional 2 studies showed that longer-term neurocognitive impairment, including dementia, was not dissimilar to nonsurgical patients with cardiovascular disease. Currently, there is no convincing evidence to suggest that cardiac surgery, and cardiopulmonary bypass in particular, has a causal role in progression to dementia, or long-term deficit, independent of pre-existing neurocognitive impairments and cardiovascular disease.

Motor Variability during Sustained Contractions Increases with Cognitive Demand in Older Adults

To expose cortical involvement in age-related changes in motor performance, we compared steadiness (force fluctuations) and fatigability of submaximal isometric contractions with the ankle dorsiflexor muscles in older and young adults and with varying levels of cognitive demand imposed. Sixteen young (20.4 ± 2.1 year: 8 men, 9 women) and 17 older adults (68.8 ± 4.4 years: 9 men, 8 women) attended three sessions and performed a 40 s isometric contraction at 5% maximal voluntary contraction (MVC) force followed by an isometric contraction at 30% MVC until task failure. The cognitive demand required during the submaximal contractions in each session differed as follows: (1) high-cognitive demand session where difficult mental math was imposed (counting backward by 13 from a 4-digit number); (2) low-cognitive demand session which involved simple mental math (counting backward by 1); and (3) control session with no mental math. Anxiety was elevated during the high-cognitive demand session compared with other sessions for both age groups but more so for the older adults than young adults (p  < 0.05). Older adults had larger force fluctuations than young adults during: (1) the 5% MVC task as cognitive demand increased (p  = 0.007), and (2) the fatiguing contraction for all sessions (p  = 0.002). Time to task failure did not differ between sessions or age groups (p  > 0.05), but the variability between sessions (standard deviation of three sessions) was greater for older adults than young (2.02 ± 1.05 vs. 1.25 ± 0.51 min, p  < 0.05). Thus, variability in lower limb motor performance for low- and moderate-force isometric tasks increased with age and was exacerbated when cognitive demand was imposed, and may be related to modulation of synergist and antagonist muscles and an altered neural strategy with age originating from central sources. These data have significant implications for cognitively demanding low-force motor tasks that are relevant to functional and ergonomic in an aging workforce.

Increased systemic inflammatory interleukin-1ß and interleukin-6 during agitation as predictors of Alzheimer's disease

OBJECTS

Identification of biomarkers for Alzheimer's disease (AD) is important for its early diagnosis and prevention and a key in advancing our understanding of its pathophysiology. The aim of this study was to determine whether systemic inflammatory interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) as well as hypertension (HT), diabetes mellitus (DM), and body mass index (BMI) are predictors of AD.

METHODS

We performed a 10-year follow-up study on 133 elderly who were institutionalized in a nursing home. The associations of IL-1ß and IL-6 at both rest and agitation, as well as HT, DM, and BMI at baseline, were analyzed with the incidences of vascular dementia (VD) and AD during a 10-year follow-up period.

RESULTS

The Kaplan-Meier method with log-rank test and Cox regression analyses for the total of 133 subjects showed significantly higher incidences of both VD and AD in subjects with DM or HT at baseline. Resting IL-1ß or IL-6 value, or agitation score, was not significantly associated with the subsequent development of VD or AD. The analyses of 40 subjects who had shown agitation at least once in the previous 3 months demonstrated that IL-1ß and IL-6 values at the agitation stage were significantly associated with AD, but not with VD.

CONCLUSION

Our results indicate that systemic inflammatory IL-1ß and IL-6 at the agitation stage are risk factors for the development of AD, but not VD. Inflammatory mechanisms for AD seem to be causal and specific to the development of AD.

Cardiovascular risk factors promote brain hypoperfusion leading to cognitive decline and dementia

Heart disease is the major leading cause of death and disability in the world. Mainly affecting the elderly population, heart disease and its main outcome, cardiovascular disease, have become an important risk factor in the development of cognitive decline and Alzheimer's disease (AD). This paper examines the evidence linking chronic brain hypoperfusion induced by a variety of cardiovascular deficits in the development of cognitive impairment preceding AD. The evidence indicates a strong association between AD and cardiovascular risk factors, including ApoE(4), atrial fibrillation, thrombotic events, hypertension, hypotension, heart failure, high serum markers of inflammation, coronary artery disease, low cardiac index, and valvular pathology. In elderly people whose cerebral perfusion is already diminished by their advanced age, additional reduction of cerebral blood flow stemming from abnormalities in the heart-brain vascular loop ostensibly increases the probability of developing AD. Evidence also suggests that a neuronal energy crisis brought on by relentless brain hypoperfusion may be responsible for protein synthesis abnormalities that later result in the classic neurodegenerative lesions involving the formation of amyloid-beta plaques and neurofibrillary tangles. Insight into how cardiovascular risk factors can induce progressive cognitive impairment offers an enhanced understanding of the multifactorial pathophysiology characterizing AD and ways at preventing or managing the cardiovascular precursors of this dementia.

Arterial hypertension, cerebrovascular diseases and dementia

Arterial hypertension (AH) is the most relevant risk factor for acute cerebrovascular disease in general. However, the prevalence of AH is not the same for the different stroke subtypes and is particularly high in lacunar infarcts and atherothrombotic stroke, low in infarcts of unusual cause and undetermined origin, and intermediate in cardioembolic stroke. This risk factor has also been related to vascular dementia and Alzheimer’s disease and their pathological manifestations (senile plaques, neurofibrillary tangles, hippocampal atrophy). The mechanisms linking AH to Alzheimer’s disease remain to be elucidated but some recent studies showed that white matter lesions seen on cerebral magnetic resonance imaging appear to be a good marker of this association. Hypertension-associated pathological changes in the brain and its vasculature include vascular remodelling and impaired cerebral autoregulation like hypoperfusion, ischemia and hypoxia, which may initiate the pathological process of Alzheimer’s disease and the expression of dementia. Therefore, prompt diagnosis and adequate control of hypertension and different vascular risk factors are the rational basis for a more effective strategy in the secondary prevention of cerebrovascular disease and dementia.

Neuropsychological function 5 years after cardiac surgery and the effect of psychological distress

Research has shown conflicting results with regard to the influence of depression and anxiety on neuropsychological performance following coronary artery bypass graft (CABG) surgery. Notably, the independent effects of depression and anxiety have not been examined among CABG candidates in the longer term where it is has been suggested that these patients show marked cognitive deterioration. A neuropsychological test battery and measures of psychological distress were completed by 86 CABG patients and 50 nonsurgical control participants at baseline and 6 months, whereas 75 patients and 36 controls, respectively, completed a 5-year follow-up. In CABG patients, cognitive and affective depressive symptoms were independently associated with lower and worse performance on the Boston Naming Test, Purdue Peg Board, and Digit Symbol Coding 6 months after surgery, whereas at 5-year follow-up an effect for Digit Symbol persisted, and an association was also observed for the Trail Making Test (TMT). On average, CABG patients performed worse on TMT and Digit Symbol at 6 months, whereas at 5-year follow-up their performance was worse on short-term delayed verbal recall. The results among the CABG patients did not show a consistent pattern of association between psychological distress and those neuropsychological domains that were on average significantly lower than a nonsurgical control group. The results here also support the use of nonbiased statistical methodology to document dysfunction among heterogeneous cognitive domains after CABG surgery.

Barriers and enablers of health promotion, prevention and early intervention in primary care: evidence to inform the Australian national dementia strategy

A comprehensive literature review was undertaken to: (i) identify and summarise the research evidence regarding barriers and enablers of health promotion, prevention and early intervention (PPEI) in primary care to reduce the risk of chronic disease in the older population; and (ii) use this evidence to make recommendations to inform the Australian national dementia prevention strategy around the translation of evidence-based care into practice. PPEI activities in primary care have the potential to not only reduce the prevalence and impact of a number of chronic diseases, but may also prevent or slow the onset of dementia given the apparent overlap in risk factors. While sizeable gaps exist regarding the most effective ways to promote the adoption of these activities, limited evidence suggests that, to be effective, PPEI activities should be quick and easy to administer, have a sound rationale and be readily incorporated into existing work processes.

Cerebral White Matter Lesions Are Associated With the Risk of Stroke But Not With Other Vascular Events

Background and Purpose— White matter lesions (WMLs) have been shown to be associated with the risk of stroke in previous studies but little is known about the prediction of other vascular events. We evaluated the risk of stroke and other vascular events according to WML volume in a large population-based sample. We also studied WML volume by type (deep or periventricular) in relation to these events.

Methods— The 3-City Study is a population-based prospective cohort of people aged ≥65 years followed up for, on average, 4.9 years. Among them, 1643 participants free of prevalent vascular events had quantitative measurements of WML volume at baseline using a fully automatic method. The risks of incident major vascular events according to WML volume were evaluated using Cox proportional hazards models.

Results— The risk of incident stroke significantly increased with increasing baseline WML volume and was multiplied by 5 for those in the highest quartile of WML volume. Nonstroke vascular events’ incidence was not associated with WML volumes, whatever their type.

Conclusions— WMLs are an independent predictor of stroke in the elderly. This association is specific because WMLs are not associated with the risk of other vascular events.

Hypertension and cognitive function

Cumulative evidence implicates hypertension in the pathogenesis of Alzheimer disease. Although it may not presently be possible to completely differentiate the effects of treatment and control of hypertension itself from those of the medication used to achieve such treatment goals, efforts directed at the treatment and control of hypertension can have significant public health impact.