Prevention of dementia in randomised double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) trial

The Association Between Hypertension and Cognitive Impairment, and the Role of Antihypertensive Medications: A Literature Review

Vascular dementia (VD) is one of the leading causes of dementia, and hypertension is a known risk factor for VD. Hypertension treatment guidelines have previously discussed an optimal blood pressure goal to prevent further cardiovascular complications with long-term management. The treatment of hypertension can prevent stroke, kidney failure, and perhaps prevent cognitive decline as well. We reviewed studies that demonstrated an association between hypertension and cognitive impairment (CI). The role of antihypertensive medications (AHM) in preventing CI was also investigated. This topic is worth exploring as dementia has high healthcare costs and will become prominent as the population in the United States ages. We used the medical subject heading (MeSH) search strategy on Pubmed and reviewed 22 articles. The studies showed that there might be a link between hypertension, AHM, and CI. The studies did not suggest a superiority of any specific AHM class to prevent CI. Further research on optimal hypertension treatment goals to prevent cognitive impairment and dementia is recommended.

Arterial Stiffness, Cognitive Dysfunction and Adherence to Antihypertensive Agents. Is there a Link to Hypertensive Patients?

The incidence of hypertension (HTN) and its cardiovascular (CV) complications are increasing throughout the world. Blood pressure (BP) control remains unsatisfactory worldwide. Medical inertia and poor adherence to treatment are among the factors that can partially explain, why BP control rate remains low. The introduction of a method for measuring the degree of adherence to a given medication is now a prerequisite. Complex treatment regimes, inadequate tolerance and frequent replacements of pharmaceutical formulations are the most common causes of poor adherence. In contrast, the use of stable combinations of antihypertensive drugs leads to improved patient adherence. We aim to review the relationships between arterial stiffness, cognitive function and adherence to medication in patients with HTN. Large artery stiffening can lead to HTN. In turn, arterial stiffness induced by HTN is associated with an increased CV and stroke risk. In addition, HTN can induce disorders of brain microcirculation resulting in cognitive dysfunction. Interestingly, memory cognitive dysfunction leads to a reduced adherence to drug treatment. Compliance with antihypertensive treatment improves BP control and arterial stiffness indices. Early treatment of arterial stiffness is strongly recommended for enhanced cognitive function and increased adherence.

Increases in hypertension-induced cerebral microhemorrhages exacerbate gait dysfunction in a mouse model of Alzheimer's disease

Clinical studies show that cerebral amyloid angiopathy (CAA) associated with Alzheimer's disease (AD) and arterial hypertension are independent risk factors for cerebral microhemorrhages (CMHs). To test the hypothesis that amyloid pathology and hypertension interact to promote the development of CMHs, we induced hypertension in the Tg2576 mouse model of AD and respective controls by treatment with angiotensin II (Ang II) and the NO synthesis inhibitor L-NAME. The number, size, localization, and neurological consequences (gait alterations) of CMHs were compared. We found that compared to control mice, in TG2576 mice, the same level of hypertension led to significantly increased CMH burden and exacerbation of CMH-related gait alterations. In hypertensive TG2576 mice, CMHs were predominantly located in the cerebral cortex at the cortical-subcortical boundary, mimicking the clinical picture seen in patients with CAA. Collectively, amyloid pathologies exacerbate the effects of hypertension, promoting the genesis of CMHs, which likely contribute to their deleterious effects on cognitive function. Therapeutic strategies for prevention of CMHs that reduce blood pressure and preserve microvascular integrity are expected to exert neuroprotective effects in high-risk elderly AD patients.

Hypothetical blood-pressure-lowering interventions and risk of stroke and dementia

We aimed to study the effects of hypothetical interventions on systolic blood pressure (SBP) and smoking on risk of stroke and dementia using data from 15 years of follow-up in the Rotterdam Study. We used data from 4930 individuals, aged 55-80 years, with no prior history of stroke, dementia or cognitive impairment, followed for 15 years within the Rotterdam Study, a population-based cohort. We defined the following sustained interventions on SBP: (1) maintaining SBP below 120 mmHg, (2) maintaining SBP below 140 mmHg, (3) reducing SBP by 10% if above 140 mmHg, (4) reducing SBP by 20% if above 140 mmHg, and a combined intervention of quitting smoking with each of these SBP-lowering strategies. We considered incident stroke and incident dementia diagnoses as outcomes. We applied the parametric g-formula to adjust for baseline and time-varying confounding. The observed 15-year risk for stroke was 10.7%. Compared to no specified intervention (i.e., the "natural course"), all interventions that involved reducing SBP were associated with a stroke risk reduction of about 10% (e.g., reducing SBP by 20% if above 140 mmHg risk ratio: 0.89; 95% CI 0.76, 1). Jointly intervening on SBP and smoking status further decreased the risk of stroke (e.g., risk ratio: 0.83; 95% CI 0.71, 0.94). None of the specified interventions were associated with a substantive change in dementia risk. Our study suggests that a joint intervention on SBP and smoking cessation during later life may reduce stroke risk, while the potential for reducing dementia risk were not observed.

Is there a relationship between blood pressure values and dementia?

The relationship between arterial hypertension and cognitive decline, two among the conditions with higher prevalence in the elderly population, has gained significant interest, in the scientific community, during the last few years, stemming from the numerous epidemiologic, experimental, and therapeutic evidences suggesting a non-casual correlation between the two conditions. In fact, the brain, for its substantial metabolic and functional complexity, is more susceptible to the harmful effect of high blood pressure than the other target organs. Chronic ischaemic impairment, microvascular damage, and neurodegenerative phenomena are the likely pathophysiologic basis for the correlation between hypertension and cognitive decline. Vascular dementia and Alzheimer’s disease, the two prominent forms of senile dementia, seem to represent the end result of the chronic exposure, during the lifetime, to harmful stimuli, among which the most relevant are the cardiovascular risk factors, at least from an epidemiological perspective. Evidences from interventional studies, although limited, seems to support the concept that to limit the spread of senile dementia, the early optimization of the control of cardiovascular risk factors, first and foremost hypertension, is crucial. The occurrence of a variable degree of mental decline, till overt dementia, in the hypertensive patient, represents the final step of a pathophysiologic process that began many years before. There is, then, the clear opportunity to control the pathophysiologic mechanisms leading to cognitive decline in the hypertensive patient.

Treatment of hypertension reduces cognitive decline in older adults: a systematic review and meta-analysis

OBJECTIVES

To systematically analyse the effect of pharmacological treatment of hypertension (HTN) on cognitive decline in older adults.

METHODS

Randomised, placebo-controlled trials with a prespecified quantitative outcome of cognition and a pharmacological intervention for at least 12 months to treat HTN in older adults (>60 years). Our primary outcome was change in cognition with pharmacological treatment of HTN. Standardised mean difference (SMD) was used to analyse different outcomes reported in the selected studies. We searched PubMed CENTRAL and the Cochrane Library from inception to 6 July 2020. Two independent reviewers assessed trial quality and extracted data. Internal and external validity of the studies was assessed.

RESULTS

Nine randomised controlled trials with 34 994 participants were included in the final analysis. The net SMD for change in cognition was -0.049 (CI: -0.078 to -0.019) indicating that treatment of HTN decreased cognitive decline. Heterogeneity was low with an I² of 6%.

DISCUSSION

Current evidence does not indicate worsening of cognition with treatment of HTN. Treatment of HTN in older adults may reduce cognitive decline. These results have important implications in clinical management of patients at risk for dementia.

PROSPERO REGISTRATION NUMBER

CRD42020139750.

Canadian Consensus Conference on Diagnosis and Treatment of Dementia (CCCDTD)5: Guidelines for management of vascular cognitive impairment

INTRODUCTION

Vascular disease is a common cause of dementia, and often coexists with other brain pathologies such as Alzheimer's disease to cause mixed dementia. Many of the risk factors for vascular disease are treatable. Our objective was to review evidence for diagnosis and treatment of vascular cognitive impairment (VCI) to issue recommendations to clinicians.

METHODS

A subcommittee of the Canadian Consensus Conference on Diagnosis and Treatment of Dementia (CCCDTD) reviewed areas of emerging evidence. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to assign the quality of the evidence and strength of the recommendations.

RESULTS

Using standardized diagnostic criteria, managing hypertension to conventional blood pressure targets, and reducing risk for stroke are strongly recommended. Intensive blood pressure lowering in middle-aged adults with vascular risk factors, using acetylsalicylic acid in persons with VCI and covert brain infarctions but not if only white matter lesions are present, and using cholinesterase inhibitors are weakly recommended.

CONCLUSIONS

The CCCDTD has provided evidence-based recommendations for diagnosis and management of VCI for use nationally in Canada, that may also be of use worldwide.

Brain Renin-Angiotensin System at the Intersect of Physical and Cognitive Frailty

The renin–angiotensin system (RAS) was initially considered to be part of the endocrine system regulating water and electrolyte balance, systemic vascular resistance, blood pressure, and cardiovascular homeostasis. It was later discovered that intracrine and local forms of RAS exist in the brain apart from the endocrine RAS. This brain-specific RAS plays essential roles in brain homeostasis by acting mainly through four angiotensin receptor subtypes; AT₁R, AT₂R, MasR, and AT₄R. These receptors have opposing effects; AT₁R promotes vasoconstriction, proliferation, inflammation, and oxidative stress while AT₂R and MasR counteract the effects of AT₁R. AT₄R is critical for dopamine and acetylcholine release and mediates learning and memory consolidation. Consequently, aging-associated dysregulation of the angiotensin receptor subtypes may lead to adverse clinical outcomes such as Alzheimer’s disease and frailty via excessive oxidative stress, neuroinflammation, endothelial dysfunction, microglial polarization, and alterations in neurotransmitter secretion. In this article, we review the brain RAS from this standpoint. After discussing the functions of individual brain RAS components and their intracellular and intracranial locations, we focus on the relationships among brain RAS, aging, frailty, and specific neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and vascular cognitive impairment, through oxidative stress, neuroinflammation, and vascular dysfunction. Finally, we discuss the effects of RAS-modulating drugs on the brain RAS and their use in novel treatment approaches.

A molecular approach to treating cognition in schizophrenia by calcium channel blockade: An open-label pilot study of the calcium-channel antagonist isradipine

Cognitive impairment is a prominent and difficult to treat symptom in schizophrenia (SZ), which is directly related to functional disability. A variant in the gene coding for the alpha 1C subunit of L-type voltage gated calcium channel (CACNA1C) has been shown to negatively affect several neurocognitive domains. We conducted a 4-week, open label, pilot study of isradipine, a calcium channel blocker, to determine its feasibility, safety, and efficacy in improving cognition in SZ patients.

Ten adults with stable SZ were started on a flexible dose of isradipine 5 mg/day (up to 10 mg/day) for 4 weeks. Weekly in-person visits tracked side effects and symptoms while neurocognition and functional capacity were assessed at baseline and week 4.

There were no serious adverse events reported. Newly emergent side effects were dizziness (1 new incidence at week 4); difficulty sleeping (2 new incidences at week 4); and decreased energy (3 new incidences at week 4). 1 patient discontinued medication and was withdrawn. Treatment did not exacerbate clinical symptoms. Although power is limited, results indicate no clear benefit on neurocognition but a positive effect (baseline mean = 6.8 ± 1.3 to week 4 mean = 7.9 ± 1.1; t = 2.91, p = 0.017) on functional capacity was noted.

This open label, pilot study provides preliminary evidence that isradipine is a relatively safe medication when used adjunctively in SZ patients. This study suggests that isradipine offers no clear cognitive and only minimal functional benefit; however, additional studies may be warranted in symptomatic patients, or those with specific CACNA1C genotypes.

Hypertension management in older adults

Vascular aging leads to arterial hypertension, which is the leading cause of cardiovascular mortality and morbidity in older adults. Blood pressure reduction is effective in reducing the cardiovascular risk and is safe in ambulatory older adults. It is important to note that blood pressure control in this group of patients is challenging because of comorbidities, polypharmacy, and frailty. Choice of pharmacotherapy is not simple and should be individualized.

Association between chronic kidney disease and Alzheimer's disease: an update

It has been accepted that kidney function is connected with brain activity. In clinical studies, chronic kidney disease (CKD) patients have been found to be prone to suffering cognitive decline and Alzheimer's disease (AD). The cognitive function of CKD patients may improve after kidney transplantation. All these indicators show a possible link between kidney function and dementia. However, little is known about the mechanism behind the relation of CKD and AD. This review discusses the associations between CKD and AD from the perspective of the pathophysiology of the kidney and complications and/or concomitants of CKD that may lead to cognitive decline in the progression of CKD and AD. Potential preventive and therapeutic strategies for AD are also presented. Further studies are warranted in order to confirm whether the setting of CKD is a possible new determinant for cognitive impairment in AD.

Blood pressure and cognitive decline - the impact of hypertension over one decade

BACKGROUND

Midlife hypertension is a risk factor for cognitive decline in late-life but little is known about the impact of long-term hypertension on cognitive change over time.

METHODS

We examined blood pressure and cognitive function in 2777 participants (baseline: 2000-2003, 45-75 years, 48.4% men) from the Heinz Nixdorf Recall study. Blood pressure was assessed at three study visits and cognitive function was assessed at both follow-ups (mean follow-up: 5.1 years). Z-score differences in five neuropsychological tests, defining cognitive decline, were derived from linear regression models including age and education. The association of cognitive decline over 5 years and blood pressure over 10 years (classified as: normal blood pressure (>10 years, reference), prevalent hypertension (>10 years), incident hypertension t1 (>5 years), incident hypertension t2 (<5 years), temporary hypertension (at least one hypertensive reading)) was calculated using linear regression models resulting in coefficient b and 95% confidence interval. We calculated interactions with age (linear and with a cutoff at 65 years).

RESULTS

Participants with prevalent hypertension showed a greater cognitive decline in both verbal memory tests. Incident hypertension t1 was associated with a greater decline in the visuospatial organization test. There was no interaction with age.

CONCLUSION

This study showed that prevalent high blood pressure over 10 years is related to cognitive decline. Prevalent hypertension with longer exposure time may be more detrimental than temporary hypertension for cognitive function.

The association of blood pressure with physical frailty and cognitive function in community-dwelling septuagenarians, octogenarians, and nonagenarians: the SONIC study

We investigated the association of systolic blood pressure (SBP) level with physical frailty and cognitive function in community-dwelling older Japanese. Using the 'Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians' survey as the baseline, we performed a cross-sectional analysis of people aged 70 ± 1 (n = 1000), 80 ± 1 (n = 978), and 90 ± 1 (n = 272) years. Medical histories and medications were collected via interviews conducted by medical professionals. Blood pressure (BP), grip strength, gait speed, and cognitive function were examined on site. Trend analysis and multiple regression analysis were used to determine the association of the SBP level with physical frailty and cognitive function. The principal finding was that the association of SBP with physical frailty and cognitive function varied depending on characteristics such as age, physical and cognitive function, and antihypertensive medication use. A lower SBP level was associated with a higher prevalence of physical frailty only among 80-year-olds who were on antihypertensive medication. A significant association was found between higher SBP and lower cognitive function among 70-year-olds, while among 90-year-olds, the opposite was found. No association was found among participants who were 80 years old or among participants of all ages without antihypertensive medication. Our finding that an inverted association between SBP and geriatric syndrome exists suggests that the treatment of older patients must be individualized to prevent geriatric syndrome.

Alzheimer's disease; a review of the pathophysiological basis and therapeutic interventions

Alzheimer's disease (AD) is a neurodegenerative disorder and is identified as the most common cause for dementia. Despite huge global economic burden and the impact on the close family of the patients, there is no definitive cure and thus, improved treatment methods are of need. While memory and cognition are severely affected in AD, exact etiology is yet unknown. The β-Amyloid plaque formation and aggregation hypothesis is among the well-known hypotheses used to explain disease pathogenesis. Currently there are five Food and Drug Administration (FDA) approved drugs as treatment options. All these drugs are used for symptomatic treatment of AD. Thus, disease modifying therapies which can directly address the pathological changes in AD, are needed. Such therapies could be designed based on inhibiting key steps of pathogenesis. Currently there are novel AD drug candidates with various therapeutic mechanisms, undergoing different stages of drug development. Extensive research is being done globally to broaden understanding of the exact mechanisms involved in AD and to develop therapeutic agents that can successfully hinder the occurrence and progression of the disease. In this review, a comprehensive approach to understanding AD and suggestions to be considered in the development of therapeutics for it are presented.

Pathological Continuum From the Rise in Pulse Pressure to Impaired Neurovascular Coupling and Cognitive Decline

The "biomechanical hypothesis" stipulates that with aging, the cumulative mechanical damages to the cerebral microvasculature, magnified by risk factors for vascular diseases, contribute to a breach in cerebral homeostasis producing neuronal losses. In other words, vascular dysfunction affects brain structure and function, and leads to cognitive failure. This is gathered under the term Vascular Cognitive Impairment and Dementia (VCID). One of the main culprits in the occurrence of cognitive decline could be the inevitable rise in arterial pulse pressure due to the age-dependent stiffening of large conductance arteries like the carotids, which in turn, could accentuate the penetration of the pulse pressure wave deeper into the fragile microvasculature of the brain and damage it. In this review, we will discuss how and why the vascular and brain cells communicate and are interdependent, describe the deleterious impact of a vascular dysfunction on brain function in various neurodegenerative diseases and even of psychiatric disorders, and the potential chronic deleterious effects of the pulsatile blood pressure on the cerebral microcirculation. We will also briefly review data from antihypertensive clinical trial aiming at improving or delaying dementia. Finally, we will debate how the aging process, starting early in life, could determine our sensitivity to risk factors for vascular diseases, including cerebral diseases, and the trajectory to VCID.

Association between Use of Angiotensin-converting Enzyme Inhibitors or Angiotensin Receptor Blockers and Postoperative Delirium

Background

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers improve cognitive function. The authors therefore tested the primary hypothesis that preoperative use of angiotensin inhibitors is associated with less delirium in critical care patients. Post hoc, the association between postoperative use of angiotensin system inhibitors and delirium was assessed.

Methods

The authors conducted a single-site cohort study of adults admitted to Cleveland Clinic critical care units after noncardiac procedures between 2013 and 2018 who had at least one Confusion Assessment Method delirium assessment. Patients with preexisting dementia, Alzheimer’s disease or other cognitive decline, and patients who had neurosurgical procedures were excluded. For the primary analysis, the confounder-adjusted association between preoperative angiotensin inhibitor use and the incidence of postoperative delirium was assessed. Post hoc, the confounder-adjusted association between postoperative angiotensin system inhibitor use and the incidence of delirium was assessed.

Results

The incidence of delirium was 39% (551 of 1,396) among patients who were treated preoperatively with angiotensin system inhibitors and 39% (1,344 of 3,468) in patients who were not. The adjusted odds ratio of experiencing delirium during critical care was 0.98 (95% CI, 0.86 to 1.10; P = 0.700) for preoperative use of angiotensin system inhibitors versus control. Delirium was observed in 23% (100 of 440) of patients who used angiotensin system inhibitors postoperatively before intensive care discharge, and in 41% (1,795 of 4,424) of patients who did not (unadjusted P &lt; 0.001). The confounder-adjusted odds ratio for experiencing delirium in patients who used angiotensin system inhibitors postoperatively was 0.55 (95% CI, 0.43 to 0.72; P &lt; 0.001).

Conclusions

Preoperative use of angiotensin system inhibitors is not associated with reduced postoperative delirium. In contrast, treatment during intensive care was associated with lower odds of delirium. Randomized trials of postoperative angiotensin-converting enzymes inhibitors and angiotensin receptor blockers seem justified.

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Effect of Combined Antihypertensive and Lipid-Lowering Therapies on Cognitive Function: A New Treatment Strategy?

Risk factors for cardiovascular disease such as hypertension and hyperlipidemia are associated with cognitive decline. However, there is still no clear evidence that the use of antihypertensive or lipid-lowering therapy can prevent or delay cognitive decline or development of dementia. To provide a reference for clinical treatment, we analyzed the potential mechanisms of cognitive dysfunction induced by hypertension and hyperlipidemia, the clinical research and controversy of antihypertensive and lipid-lowering therapies on cognitive function, and the clinical value of combined antihypertensive and lipid-lowering therapy. It is currently believed that hypertension and elevated blood cholesterol levels in middle-aged people may be related to cognitive impairment or dementia in the elderly. Some studies suggest that intensive antihypertensive or lipid-lowering therapies are better than standard antihypertensive or lipid-lowering therapy, yet further tests are needed to confirm their effects on cognitive function. Actively controlling potential risk factors from middle age may be important for Alzheimer's disease (AD) prevention.

The progression of carotid atherosclerosis and imaging markers of dementia

INTRODUCTION

We studied the association of carotid intima-media thickness (CIMT) with hippocampal volume (HV) in community dwelling individuals, testing the hypothesis that persons with carotid atherosclerosis progression would have lower HV.

METHODS

We studied 1376 Framingham Offspring participants with two carotid ultrasounds and brain magnetic resonance imaging (MRIs). We used multivariable linear regression analyses to relate CIMT progression and HV and total brain volume. Regression models were adjusted for demographics and vascular risk factors, time interval between imaging examinations, and baseline CIMT. We assessed effect modification by hypertension treatment (HRx).

RESULTS

Participants with higher ICA IMT progression had significantly lower HV after adjustment for vascular risk factors and baseline IMT (standardized beta ± standard error: -0.067 ± 0.027, P = .01). We observed weaker association between ICA IMT change and HV among subjects treated for hypertension (β = -0.047, P = .19 vs β = -0.096, P = .026).

DISCUSSION

Cumulative vascular risk factor exposure, reflected by CIMT progression, may increase the risk of neurodegeneration.

Impact of Hypertension on Cognitive Decline and Dementia

Dementia reduces a person’s ability to perform their activities of daily living and is the leading cause of morbidity worldwide. While most preventive measures are ineffective in reducing dementia risk, active treatment of hypertension in middle-aged and older adults without dementia may reduce the incidence of dementia. Hypertension is associated with vascular dementia but may also affect the manifestations of Alzheimer disease. Observational studies support the association between hypertension and white matter lesions, hippocampal atrophy, and cognitive decline. Both increased and decreased blood pressure were related to the development of white matter lesions. Cohort studies showed that hypertension treatment and treatment duration were associated with lower cognitive decline. This review describes findings from randomized controlled studies on the effects of antihypertensives on cognitive decline. Only the Systolic Hypertension in Europe (Syst-Eur) trial using calcium-channel blockers demonstrated a significant reduction in dementia incidence. Further studies are required to evaluate the long-term benefits of antihypertensive treatment in dementia.

Blood Pressure Variability and the Risk of Dementia: A Nationwide Cohort Study

To investigate the association between visit-to-visit variability in blood pressure and the incidence of dementia and its subtypes in a general population, we conducted a population-based retrospective cohort study using the Korean National Health Insurance System database. We identified 7 844 814 subjects without a history of any dementia who underwent ≥3 health examinations from 2005 to 2012 in the Korean National Health Insurance System cohort. Blood pressure variability (BPV) was measured using the variability independent of the mean, coefficient of variation, and SD. During the median follow-up of 6.2 years, there were 200 574 cases of all-cause dementia (2.8%), 165 112 cases of Alzheimer's disease (2.1%), and 27 443 cases of vascular dementia (0.3%). There was a linear association between higher BPV and outcome measures. In the multivariable adjusted model, the hazard ratios and 95% CIs of all-cause dementia were 1.06 (1.04-1.07) for the highest quartile of variability independent of the mean of diastolic blood pressure only, 1.09 (1.08-1.11) for that of systolic blood pressure only, and 1.18 (1.16-1.19) for that of both systolic and diastolic blood pressure compared with subjects having no highest quartile for BPV. Consistent results were noted for Alzheimer's disease and vascular dementia using other indices of variability and in various sensitivity and subgroup analyses. BPV is an independent predictor for developing dementia and its subtypes. A dose-response relationship was noted between higher BPV and dementia incidence. Reducing BPV may be a target for preventing dementia in the general population.

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.

[White matter hyperintensities in ageing: Pathophysiology, associated cognitive disorders and prevention]

White matter hyperintensities (WMH), also known as leukoaraïosis are very common neuroradiological manifestations in the elderly. The main risk factors for WMH are age and high blood pressure. The vascular origin of these lesions is classically accepted and WMH are considered as one feature of the small vessel disease. WMH may be associated with clinical symptoms, depending notably on their importance according to age. They are associated with increased mortality, strokes and changes in cognition with a higher risk of dementia (vascular dementia or Alzheimer's disease). Modification of vascular risk factors could have a beneficial effect, but few evidences from controlled trials are available.

Hypertension in older adults: Assessment, management, and challenges

Hypertension in older adults is related to adverse cardiovascular outcomes, such as heart failure, stroke, myocardial infarction, and death. The global burden of hypertension is increasing due to an aging population and increasing prevalence of obesity, and is estimated to affect one third of the world's population by 2025. Adverse outcomes in older adults are compounded by mechanical hemodynamic changes, arterial stiffness, neurohormonal and autonomic dysregulation, and declining renal function. This review highlights the current evidence and summarizes recent guidelines on hypertension, pertaining to older adults. Management strategies for hypertension in older adults must consider the degree of frailty, increasingly complex medical comorbidities, and psycho-social factors, and must therefore be individualized. Non-pharmacological lifestyle interventions should be encouraged to mitigate the risk of developing hypertension, and as an adjunctive therapy to reduce the need for medications. Pharmacological therapy with diuretics, renin-angiotensin system blockers, and calcium channel blockers have all shown benefit on cardiovascular outcomes in older patients. Given the economic and public health burden of hypertension in the United States and globally, it is critical to address lifestyle modifications in younger generations to prevent hypertension with age.

Neurovascular and Cognitive Dysfunction in Hypertension

Hypertension has emerged as a leading cause of age-related cognitive impairment. Long known to be associated with dementia caused by vascular factors, hypertension has more recently been linked also to Alzheimer disease-the major cause of dementia in older people. Thus, although midlife hypertension is a risk factor for late-life dementia, hypertension may also promote the neurodegenerative pathology underlying Alzheimer disease. The mechanistic bases of these harmful effects remain to be established. Hypertension is well known to alter in the structure and function of cerebral blood vessels, but how these cerebrovascular effects lead to cognitive impairment and promote Alzheimer disease pathology is not well understood. Furthermore, critical questions also concern whether treatment of hypertension prevents cognitive impairment, the blood pressure threshold for treatment, and the antihypertensive agents to be used. Recent advances in neurovascular biology, epidemiology, brain imaging, and biomarker development have started to provide new insights into these critical issues. In this review, we will examine the progress made to date, and, after a critical evaluation of the evidence, we will highlight questions still outstanding and seek to provide a path forward for future studies.

Antihypertensive agents in Alzheimer's disease: beyond vascular protection

Introduction: Midlife hypertension has been consistently linked with increased risk of cognitive decline and Alzheimer's disease (AD). Observational studies and randomized trials show that the use of antihypertensive therapy is associated with a lesser incidence or prevalence of cognitive impairment and dementia. However, whether antihypertensive agents specifically target the pathological process of AD remains elusive.Areas covered: This review of literature provides an update on the clinical and preclinical arguments supporting anti-AD properties of antihypertensive drugs. The authors focused on validated all classes of antihypertensive treatments such as angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), calcium channel blockers (CCB), β-blockers, diuretics, neprilysin inhibitors, and other agents. Three main mechanisms can be advocated: action on the concurrent vascular pathology, action on the vascular component of Alzheimer's pathophysiology, and action on nonvascular targets.Expert opinion: In 2019, while there is no doubt that hypertension should be treated in primary prevention of vascular disease and in secondary prevention of stroke and mixed dementia, the place of antihypertensive agents in the secondary prevention of 'pure' AD remains an outstanding question.

Change in NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) Level and Risk of Dementia in Multi-Ethnic Study of Atherosclerosis (MESA)

Cross-sectionally measured NT-proBNP (N-terminal pro-B-type natriuretic peptide) is related to incident dementia. However, data linking changes in NT-proBNP to risk of future dementia are lacking. We aimed to examine the association of change in NT-proBNP over 3.2 years with incident dementia. We included 4563 participants in MESA (Multi-Ethnic Study of Atherosclerosis) prospective cohort who were free of cardiovascular disease at enrollment, had NT-proBNP level measured at MESA exams 1 (baseline, 2000-2002) and 3 (2004-2005), and had no diagnosis of dementia before exam 3. The association of change in NT-proBNP level between MESA exams 1 through 3 and all-cause hospitalized dementia (by International Classification of Diseases, Ninth Revision, codes) after MESA exam 3 (2004-2005) through 2015 was assessed using competing-risks Cox proportional hazard regression analysis. During 45 522 person-years of follow-up, 223 dementia cases were documented. Increase in log-NT-proBNP from MESA exams 1 through 3 was positively associated with incidence of dementia (multivariable hazard ratio, 1.28 [95% CI, 1.001-1.64]; P=0.049). An increase of at least 25% in NT-proBNP level from MESA exam 1 through 3 was associated with a 55% (P=0.02) increase in the risk of dementia in multivariable analysis. Addition of temporal NT-proBNP change to a model including risk factors and baseline NT-proBNP improved the prediction of dementia (Harrell C statistic from 0.85 to 0.87, P=0.049). Increase in NT-proBNP is independently associated with future all-cause hospitalized dementia and offers a moderately better predictive performance for risk of dementia compared with risk factors and baseline NT-proBNP. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00005487.

Physical Activity Is Associated With Lower Odds of Cognitive Impairment in Women but Not Men Living With Human Immunodeficiency Virus Infection

Background

Cardiovascular comorbidities are risk factors for human immunodeficiency virus (HIV)-associated cognitive impairment. Given differences in cardiometabolic risk profiles between women and men with HIV, we investigated whether associations between cardiometabolic risk factors and prevalent cognitive impairment differ by sex.

Methods

Separate logistic regression models were constructed for women and men at entry into a prospective study of older persons with HIV (PWH) to assess the association of cardiometabolic and other risk factors with cognitive impairment.

Results

Of 988 participants, 20% were women. Women had higher total cholesterol (194 vs 186 mg/dL; P = .027), hemoglobin A1c (5.9% vs 5.7%; P = .003), and body mass index (30.8 vs 27.4 kg/m2; P < .001) compared with men, and were less physically active (43% vs 55%; P = .005). In a multivariable model, physical activity was associated with lower odds of cognitive impairment in women (odds ratio, 0.35 [95% confidence interval, .15-.80]; P = .013) but not men.

Conclusions

Physical activity may have a greater positive impact on cognitive health in women than in men with HIV. This finding should be confirmed in studies examining the longitudinal association between physical activity and incident cognitive impairment in PWH and the effect of interventions that increase physical activity on cognitive impairment in women with HIV.

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

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

Blood Pressure Variability and Progression of Clinical Alzheimer Disease

Blood pressure variability (BPV) has been shown to have predictive value over blood pressure (BP) levels alone in stroke patients. We assessed whether BPV predicts cognitive and functional decline in Alzheimer disease, using data from a randomized trial (NILVAD [A European Multicentre Double-blind Placebo-controlled Phase III Trial of Nilvadipine in Mild to Moderate Alzheimer’s Disease]). Patients with mild-to-moderate Alzheimer disease were included if they had ≥3 office BP measurements available to determine visit-to-visit BPV. Day-to-day BPV was assessed using home BP measurements in a subsample. The variation independent of mean was used to calculate BPV. Outcomes were change in Alzheimer’s Disease Assessment Scale–cognitive subscale-12 and Disability Assessment for Dementia after 1 and 1.5 years. A total of 460 patients aged 72.1 (SD=8.1) years, with mean BP of 134.0/75.1 (10.9/6.3) mm Hg were included. After 1 year, patients in the highest quartile of BPV had deteriorated more on Alzheimer’s Disease Assessment Scale–cognitive subscale compared with patients in the lowest quartile (systolic: β, 2.24 [95% CI, 0.11–4.38], P =0.040; diastolic: β, 2.54 [95% CI, 0.33–4.75] P =0.024). This association was still present after 1.5 years (systolic: β, 2.86 [95% CI, 0.35–5.36], P =0.026; diastolic: β, 3.30 [95% CI, 0.67–5.93], P =0.014). There was no effect of visit-to-visit BPV on Disability Assessment for Dementia. Day-to-day BPV was available for 46 patients. Significant associations were observed between day-to-day BPV and deterioration on Alzheimer’s Disease Assessment Scale–cognitive subscale (systolic: P =0.036) and Disability Assessment for Dementia (systolic: P =0.020; diastolic: P =0.007) after 1 year, but not after 1.5 years. All associations were adjusted for potential confounders, including intervention group. In conclusion, this post hoc analysis indicates that higher visit-to-visit and day-to-day BPV might be associated with progression of Alzheimer disease. Targeting BPV may be a future target to slow decline in patients with Alzheimer disease.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02017340.

The Angiotensin Type 1 Receptor Antagonist Losartan Prevents Ovariectomy-Induced Cognitive Dysfunction and Anxiety-Like Behavior in Long Evans Rats

Women who have bilateral oophorectomies prior to the age of natural menopause are at increased risk of developing mild cognitive decline, dementia, anxiety, and depressive type disorders. Clinical and animal studies indicate angiotensin type 1 receptor (AT₁R) blockers (ARBs) have blood pressure (BP)-independent neuroprotective effects. To investigate the potential use of ARBs in normotensive women at increased risk of developing neurocognitive problems, we studied a rat model of bilateral oophorectomy. Long Evans rats were sham-operated (Sham) or ovariectomized (Ovx) at 3 months of age and immediately treated continuously with vehicle (Veh) or the ARB losartan (Los) for the duration of the experiment. In contrast to many hypertensive rat models, ovariectomy did not increase mean arterial pressure (MAP) in these normotensive rats. Ovariectomized rats spent less time in the open arms of the elevated plus maze (EPM) [(% total time): Veh, 34.1 ± 5.1 vs. Ovx, 18.7 ± 4.4; p < 0.05] and in the center of the open field (OF) [(s): Veh, 11.1 ± 1.7 vs. Ovx, 6.64 ± 1.1; p < 0.05]. They also had worse performance in the novel object recognition (NOR) test as evidenced by a reduction in the recognition index [Veh, 0.62 ± 0.04 vs. Ovx, 0.45 ± 0.03; p < 0.05]. These adverse effects of ovariectomy were prevented by Los. Losartan also reduced plasma corticosterone in Ovx rats compared to Veh treatment [(ng/mL): Ovx–Veh, 238 ± 20 vs. Ovx–Los, 119 ± 42; p < 0.05]. Ovariectomy increased AT₁R mRNA expression in the CA3 region of the hippocampus (Hc) [(copies x 10⁶/µg RNA): Sham–Veh, 7.15 ± 0.87 vs. Ovx–Veh, 9.86 ± 1.7; p < 0.05]. These findings suggest the neuroprotective effects of this ARB in normotensive Ovx rats involve reduction of plasma corticosterone and blockade of increased AT₁R activity in the hippocampus. These data suggest ARBs have therapeutic potential for normotensive women at increased risk of developing cognitive and behavioral dysfunction due to bilateral oophorectomy prior to the natural age of menopause.

Common risk factors for major noncommunicable disease, a systematic overview of reviews and commentary: the implied potential for targeted risk reduction

Noncommunicable disease now contributes to the World Health Organization top 10 causes of death in low-, middle- and high-income countries. Particular examples include stroke, coronary heart disease, dementia and certain cancers. Research linking clinical and lifestyle risk factors to increased risk of noncommunicable disease is now well established with examples of confirmed risk factors, including smoking, physical inactivity, obesity and hypertension. However, despite a need to target our resources to achieve risk reduction, relatively little work has examined the overlap between the risk factors for these main noncommunicable diseases. Our high-level review draws together the evidence in this area. Using a systematic overview of reviews, we demonstrate the likely commonality of established risk factors having an impact on multiple noncommunicable disease outcomes. For example, systematic reviews of the evidence on physical inactivity and poor diet found each to be associated with increased risk of cancers, coronary heart disease, stroke, diabetes mellitus and dementia. We highlight the potential for targeted risk reduction to simultaneously impact multiple noncommunicable disease areas. These relationships now need to be further quantified to allow the most effective development of public health interventions in this area.

Hypertension and Its Impact on Stroke Recovery: From a Vascular to a Parenchymal Overview

Hypertension is the first modifiable vascular risk factor accounting for 10.4 million deaths worldwide; it is strongly and independently associated with the risk of stroke and is related to worse prognosis. In addition, hypertension seems to be a key player in the implementation of vascular cognitive impairment. Long-term hypertension, complicated or not by the occurrence of ischemic stroke, is often reviewed on its vascular side, and parenchymal consequences are put aside. Here, we sought to review the impact of isolated hypertension or hypertension associated to stroke on brain atrophy, neuron connectivity and neurogenesis, and phenotype modification of microglia and astrocytes. Finally, we discuss the impact of antihypertensive therapies on cell responses to hypertension and functional recovery. This attractive topic remains a focus of continued investigation and stresses the relevance of including this vascular risk factor in preclinical investigations of stroke outcome.

Multi-level community interventions for primary stroke prevention: A conceptual approach by the World Stroke Organization

The increasing burden of stroke and dementia emphasizes the need for new, well-tolerated and cost-effective primary prevention strategies that can reduce the risks of stroke and dementia worldwide, and specifically in low- and middle-income countries (LMICs).

 This paper outlines conceptual frameworks of three primary stroke prevention strategies: (a) the “polypill” strategy; (b) a “population-wide” strategy; and (c) a “motivational population-wide” strategy.

 (a) A polypill containing generic low-dose ingredients of blood pressure and lipid-lowering medications (e.g. candesartan 16 mg, amlodipine 2.5 mg, and rosuvastatin 10 mg) seems a safe and cost-effective approach for primary prevention of stroke and dementia.

 (b) A population-wide strategy reducing cardiovascular risk factors in the whole population, regardless of the level of risk is the most effective primary prevention strategy. A motivational population-wide strategy for the modification of health behaviors (e.g. smoking, diet, physical activity) should be based on the principles of cognitive behavioral therapy. Mobile technologies, such as smartphones, offer an ideal interface for behavioral interventions (e.g. Stroke Riskometer app) even in LMICs.

 (c) Community health workers can improve the maintenance of lifestyle changes as well as the adherence to medication, especially in resource poor areas. An adequate training of community health workers is a key point.

Conclusion

An effective primary stroke prevention strategy on a global scale should integrate pharmacological (polypill) and lifestyle modifications (motivational population-wide strategy) interventions. Side effects of such an integrative approach are expected to be minimal and the benefits among individuals at low-to-moderate risk of stroke could be significant. In the future, pragmatic field trials will provide more evidence.

A Low Ankle-Brachial Index and High Brachial-Ankle Pulse Wave Velocity Are Associated with Poor Cognitive Function in Patients Undergoing Hemodialysis

Patients with end-stage renal disease (ESRD) have an increased risk of both impaired cognitive function and peripheral artery disease (PAD) than the general population. The association between PAD and dementia is recognized, but there are limited studies in patients with ESRD. The aim of this study was to evaluate the relationship between ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) and cognitive impairment in patients receiving hemodialysis (HD). We enrolled 136 prevalent HD patients (mean age 59.3 ± 10.5 years, 55.9% male). Cognitive performance was measured using the Montreal Cognitive Assessment (MoCA) and Cognitive Abilities Screening Instrument (CASI) by trained psychiatrists. Associations between the cognitive function and ABI and baPWV were assessed using multiple linear regression analysis. Compared with HD patients with ABI ≥ 0.9, patients with ABI < 0.9 had lower MoCA score (p = 0.027) and lower CASI score but did not achieve significant level (p = 0.056). In the multivariate stepwise linear regression analysis, ABI (per 0.1) was independently positively associated with the MoCA score (β coefficient = 0.62, p = 0.011) and the CASI score (β coefficient = 1.43, p = 0.026). There is a negative association between baPWV (per 100 cm/s) and CASI (β coefficient = −0.70, p = 0.009). In conclusion, a low ABI or high baPWV was associated with a lower cognitive function in HD patients.

Hypertension, Diabetes and Neurodegenerative Diseases: Is there a Clinical Link through the Ca2+/cAMP Signalling Interaction?

BACKGROUND

Hypertension, diabetes and neurodegenerative diseases are among the most prevalent medical problems around the world, costing millions of dollars to the medical health systems. Indeed, hypertension has been associated with higher risk for decline of cognition, as evidenced in patients with Alzheimer´s disease (AD). Furthermore, there is a clear relationship between hypertension and diabetes, reflecting substantial overlap in their etiology. Calcium (Ca2+) channel blockers (CCBs) have been classically prescribed for treating hypertension because of their mechanism of action due to reducing the influx of Ca2+ into the smooth muscles cells. In addition, many clinical and experimental studies have been demonstrating pleiotropic effects for CCBs. For instance, in hypertensive patients treated with CCBs, it can be observed lower incidence of neurodegenerative diseases such as AD. The virtual mechanism of action could be attributed to a restoration and maintenance of Ca2+ homeostasis, which is dysregulated in the neurodegenerative diseases, including also a reduction of neuronal apoptosis as part of these CCBs pleiotropic effects. Similarly, in hypertensive patients treated with CCBs, it can be observed an improvement of diabetes status such as glycemic control. A possible mechanism of action under debate could be attributed to a restoration of insulin secretion, then achieving glycemic control, and reduction of pancreatic β-cell apoptosis.

CONCLUSION

Considering the discovery of our group entitled "calcium paradox" due to Ca2+/cAMP signalling interaction, in this review I discussed the virtual involvement of this interaction in the pleiotropic effects of CCBs, including the possible role of the Ca2+/cAMP signalling interaction in the association between hypertension and higher risk for the decline of cognition, and diabetes.

Study protocol of the self-monitoring activity program: Effects of activity on incident dementia

Introduction

Numerous studies have focused on nonpharmacological interventions on cognitive function and the effects of cognitive function on daily living. However, effects of behavior change techniques that promote physical, cognitive, and social activities on cognitive function and incident dementia in the elderly are yet to be elucidated. In this study, we aimed to design a single-blind, randomized controlled trial to study dementia prevention effects of behavior change techniques, using an accelerometer and a newly developed daily activity booklet in community-living older adults.

Methods

The study cohort comprised 5390 individuals aged 65 years and older who were randomized into one of the following three groups: accelerometer group (n = 1508), accelerometer and daily activity booklet group (n = 1180), or a control group (n = 2702; vs. accelerometer group [n = 1509] vs. accelerometer and daily activity booklet group [n = 1193]). Incident dementia was diagnosed based on the Japanese Health Insurance System data. The participants without dementia at baseline, who are diagnosed with dementia over a 36-month follow-up period, are considered to have incident dementia. The participants of the accelerometer group were asked to wear the accelerometer everyday and visit a site having data readers to download the accelerometer data every month. The subjects of the booklet group were requested to not only wear the accelerometer but also record the physical, cognitive, and social activities. The participants receive a feedback report from the data of the accelerometer and booklet.

Discussion

The study has the potential to provide the first evidence of effectiveness of the self-monitoring tools in incident dementia. In case our trial results suggest a delayed dementia onset upon self-monitoring interventions, the study protocol will provide a cost-effective and safe method for maintaining a healthy cognitive aging.

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We aim to study dementia prevention effects of behavior change techniques.

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The study may shed light on the effect of self-monitoring in dementia prevention.

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The findings may provide a safe method for maintaining a healthy cognitive aging.

2018 Korean society of hypertension guidelines for the management of hypertension: part III-hypertension in special situations

Treatment of hypertension improves cardiovascular, renal, and cerebrovascular outcomes. However, the benefit of treatment may be different according to the patients’ characteristics. Additionally, the target blood pressure or initial drug choice should be customized according to the special conditions of the hypertensive patients. In this part III, we reviewed previous data and presented recommendations for some special populations such as diabetes mellitus, chronic kidney disease, elderly people, and cardio-cerebrovascular disease.

Vascular Cognitive Impairment and Dementia: JACC Scientific Expert Panel

Cognitive impairment associated with aging has emerged as one of the major public health challenges of our time. Although Alzheimer's disease is the leading cause of clinically diagnosed dementia in Western countries, cognitive impairment of vascular etiology is the second most common cause and may be the predominant one in East Asia. Furthermore, alterations of the large and small cerebral vasculature, including those affecting the microcirculation of the subcortical white matter, are key contributors to the clinical expression of cognitive dysfunction caused by other pathologies, including Alzheimer's disease. This scientific expert panel provides a critical appraisal of the epidemiology, pathobiology, neuropathology, and neuroimaging of vascular cognitive impairment and dementia, and of current diagnostic and therapeutic approaches. Unresolved issues are also examined to shed light on new basic and clinical research avenues that may lead to mitigating one of the most devastating human conditions.

Comparative study of pharmacological correction strategies for moderate cognitive impairment in hypertensive patients

Objective: to investigate the prevalence of cognitive impairment (CI) and possibilities of its pharmacological correction in hypertensive patients, by comparatively evaluating the efficiency of different treatment options: antihypertensive therapy and its combinations with vasoactive drugs and the dopamine receptor agonist piribedil.

Patients and methods. At the first stage of the investigation, the prevalence of CI was assessed in a continuous sample of hypertensive patients (n=350). The second stage included a naturalistic comparative study of the efficiency of various therapeutic strategies for moderate CI (MCI) in patients with Stage 1–2 hypertension (n=91). This investigation lasted 48 weeks and consisted of a 24-week treatment period and a 24-weeks follow-up period.

Results and discussion. CI was diagnosed in 83.4% of patients in the continuous sample, while it reached the level of dementia in 16.9%. Therapy aimed at achieving and maintaining blood pressure (BP) targets did not lead to the regression of MCI. However, BP correction in combination with a 24-week piribedil therapy cycle was optimal in patients with CI. By the end of treatment, the Montreal Cognitive Assessment (MoCa) scores increased from 24.5Ѓ}0.8 to 27.5Ѓ}0.6 (p<0.05) and from 24.9Ѓ}0.7 to 27.1Ѓ}0.8 (p<0.05) in the groups of patients randomized to supplemental piribedil alone or in combination with nootropic and/or vascular drugs, respectively. There were no intergroup differences in the groups of patients randomized to supplemental piribedil. The time course of cognitive changes in the further follow-up period showed a longterm positive effect of piribedil on cognitive function.

Conclusion. It is necessary to regularly screen for cognitive dysfunction in hypertensive patients. The most effective treatment in combination with a long-term piribedil therapy cycle for hypertension-associated MCI was to promote the achievement and retention of blood pressure targets.

Hypertension and Dementia: A comprehensive review from the HOPE Asia Network

Approximately 365 million people in Asia were classified as elderly in 2017. This number is rising and expected to reach approximately 520 million by 2030. The risk of hypertension and cognitive impairment/dementia increases with age. Recent data also show that the prevalence of hypertension and age-related dementia are rising in Asian countries. Moreover, not many people in Asian countries are aware of the relationship between hypertension and cognitive impairment/dementia. Furthermore, hypertension control is poorer in Asia than in developed countries. Hypertension is known to be a major risk factor for damage to target organs, including the brain. Decreased cognitive function can indicate the presence of target organ damage in the brain. Twenty-four-hour blood pressure profiles and blood pressure variability have been associated with cognitive impairment and/or silent cerebral diseases, such as silent cerebral infarction or white matter lesions, which are predisposing conditions for cognitive impairment and dementia. Hypertension that occurs in midlife also affects the incidence of cognitive impairments in later life. Managing and controlling blood pressure could preserve cognitive functions, such as by reducing the risk of vascular dementia and by reducing the global burden of stroke, which also affects cognitive function.

The Coming of Age of the Angiotensin Hypothesis in Alzheimer's Disease: Progress Toward Disease Prevention and Treatment?

There is wide recognition of a complex association between midlife hypertension and cardiovascular disease and later development of Alzheimer’s disease (AD) and cognitive impairment. While significant progress has been made in reducing rates of mortality and morbidity due to cardiovascular disease over the last thirty years, progress towards effective treatments for AD has been slower. Despite the known association between hypertension and dementia, research into each disease has largely been undertaken in parallel and independently. Yet over the last decade and a half, the emergence of converging findings from pre-clinical and clinical research has shown how the renin angiotensin system (RAS), which is very important in blood pressure regulation and cardiovascular disease, warrants careful consideration in the pathogenesis of AD. Numerous components of the RAS have now been found to be altered in AD such that the multifunctional and potent vasoconstrictor angiotensin II, and similarly acting angiotensin III, are greatly altered at the expense of other RAS signaling peptides considered to contribute to neuronal and cognitive function. Collectively these changes may contribute to many of the neuropathological hallmarks of AD, as well as observed progressive deficiencies in cognitive function, while also linking elements of a number of the proposed hypotheses for the cause of AD. This review discusses the emergence of the RAS and its likely importance in AD, not only because of the multiple facets of its involvement, but also perhaps fortuitously because of the ready availability of numerous RAS-acting drugs, that could be repurposed as interventions in AD.