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

Hypertension and Mild Cognitive Impairment: State-of-the-Art Review

BACKGROUND

Mid-life hypertension is associated with cognitive decline and dementia in later life. Reducing high blood pressure (BP) with antihypertensive agents is a well-researched strategy to prevent dementia and mild cognitive impairment (MCI). However, there is still limited direct evidence to support the approach, and particularly for the treatment of the very old and those with existing MCI.

METHODS

This review presents an overview of the current evidence for the relationship between MCI and hypertension, and of the potential pathophysiological mechanisms related to cognitive decline and incidence dementia in relation to aging.

RESULTS

Although observational data are near consistent in showing an association between mid-life hypertension and MCI and/or dementia, the evidence in relation to hypertension in younger adults and the very old (age >80 years) is much more limited. Most of the commonly available antihypertensive agents appear to provide beneficial effects in reducing the risk dementia, but there is limited evidence to support such treatment in those with existing MCI.

CONCLUSIONS

Further studies are needed to determine the optimal levels of BP control across different age groups, especially in adults with MCI, and which class(es) of antihypertensive agents and duration of treatment best preserve cognitive function in those at risk of, or with established, MCI.

Can white matter hyperintensities based Fazekas visual assessment scales inform about Alzheimer's disease pathology in the population?

Background

White matter hyperintensities (WMH) are considered hallmark features of cerebral small vessel disease and have recently been linked to Alzheimer's disease pathology. Their distinct spatial distributions, namely periventricular versus deep WMH, may differ by underlying age-related and pathobiological processes contributing to cognitive decline. We aimed to identify the spatial patterns of WMH using the 4-scale Fazekas visual assessment and explore their differential association with age, vascular health, Alzheimer's imaging markers, namely amyloid and tau burden, and cognition. Because our study consisted of scans from GE and Siemens scanners with different resolutions, we also investigated inter-scanner reproducibility and combinability of WMH measurements on imaging.

Methods

We identified 1144 participants from the Mayo Clinic Study of Aging consisting of older adults from Olmsted County, Minnesota with available structural magnetic resonance imaging (MRI), amyloid, and tau positron emission tomography (PET). WMH distribution patterns were assessed on FLAIR-MRI, both 2D axial and 3D, using Fazekas ratings of periventricular and deep WMH severity. We compared the association of periventricular and deep WMH scales with vascular risk factors, amyloid-PET and tau-PET standardized uptake value ratio, WMH volume, and cognition using Pearson partial correlation after adjusting for age. We also evaluated vendor compatibility and reproducibility of the Fazekas scales using intraclass correlations (ICC).

Results

Periventricular and deep WMH measurements showed similar correlations with age, cardiometabolic conditions score (vascular risk), and cognition, (p < 0.001). Both periventricular WMH and deep WMH showed weak associations with amyloidosis (R = 0.07, p = < 0.001), and none with tau burden. We found substantial agreement between data from the two scanners for Fazekas measurements (ICC = 0.78). The automated WMH volume had high discriminating power for identifying participants with Fazekas ≥ 2 (area under curve = 0.97).

Conclusion

Our study investigates risk factors underlying WMH spatial patterns and their impact on global cognition, with no discernible differences between periventricular and deep WMH. We observed minimal impact of amyloidosis on WMH severity. These findings, coupled with enhanced inter-scanner reproducibility of WMH data, suggest the combinability of inter-scanner data assessed by harmonized protocols in the context of vascular contributions to cognitive impairment and dementia biomarker research.

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

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

The Relation Between Arterial Hypertension and Cognitive Impairment: A Literature Review

The global increase in dementia cases, driven by improved life expectancy and reduced elderly mortality rates, presents a significant public health challenge. Dementia, characterized by a gradual and irreversible decline in cognitive abilities, affects individuals aged 65 and older, disrupting lives and straining healthcare systems. Hypertension significantly influences dementia development. Research consistently links midlife hypertension to cognitive decline, mild cognitive impairment (MCI), and dementia, but findings in older adults vary. While some studies suggest that late-life hypertension accelerates cognitive decline and dementia risk, others propose a protective effect. The impact of hypertension on cognition varies across age groups, spanning from childhood to late life. High blood pressure during midlife and earlier life stages consistently predicts poorer cognitive outcomes. Executive function, attention, and motor speed are the cognitive domains most affected by hypertension, particularly in subcortical diseases. Memory impairments in hypertension-related dementias are complex, often overlapping with other causes. Understanding the inconsistent findings in older adults regarding hypertension, cognitive decline, and dementia risk requires comprehensive exploration of methodological and biological factors. Addressing hypertension and its management may hold the key to reducing the risk of cognitive decline and dementia, especially in midlife and earlier life stages.

What have clinical trials taught us about brain health?

The Global Burden of Disease Study projects an almost tripling of dementia cases worldwide in the next 30 years making it important to recognize and understand modifiable risks and preventatives for cognitive impairment. Recent studies suggest that prevention or treatment of cardiovascular risks may be an important strategy to prevent or slow the progression of cognitive impairment. In 2017, the American Heart Association and American Stroke Association introduced metrics for "optimal brain health". These metrics defined brain health in terms of ideal health behaviors and factors. Since then and leading up to 2017, a number of clinical trials have been conducted to investigate the potential of modification of cardiovascular risks on prevention of dementia or cognitive impairment and thus, enhancement of brain health. This discussion is a review of findings from clinical trials focusing on interventions, including antihypertensive agents, glycemic control and lipid-lowering therapies, multidomain approaches, and antithrombotic medications. Notably, the results highlight the promise of intensive blood pressure lowering strategies and multidomain approaches, as evidenced by the FINGER trial. The review also discusses the potential of treatment or prevention of cerebral small vessel disease (cSVD) and the application of Mendelian randomization as a strategy to preserve brain structure and function.

Blood pressure variability, dementia, and role of antihypertensive medications in older adults

INTRODUCTION

We assessed the association between visit-to-visit blood pressure variability (BPV) up to 12 years and subsequent dementia risk, and tested the modifying effect of antihypertensive medications.

METHODS

We studied 2234 participants from two community-based cohorts of older adults with normal cognition or mild cognitive impairment. Participants were followed through annual assessments for up to 27 years. Visit-to-visit BPV was quantified over 3, 6, 9, and 12 years, respectively.

RESULTS

Higher systolic BPV (SBPV) during 3, 6, 9, and 12 years was associated with a subsequent increased risk of dementia, with hazard ratios ranging from 1.02 (95% confidence interval [CI]: 1.01-1.04) to 1.10 (95% CI: 1.05-1.16). The association between SBPV and dementia risk was stronger among participants not taking calcium channel blockers (p-for interaction < 0.05).

DISCUSSION

Among older adults, long-term exposure to higher visit-to-visit SBPV is associated with an increased risk of dementia later in life, and calcium channel blockers may modify this association.

HIGHLIGHTS

Among adults aged >65, higher systolic blood pressure variability spanning 3-12 years is associated with an increased risk of dementia later in life. Single blood pressure measurement or mean blood pressure levels does not seem to associate with dementia risk among older adults. The association between systolic blood pressure variability and dementia risk is stronger among those not taking calcium channel blocker medications.

Clinical trials in vascular cognitive impairment following SPRINT-MIND: An international perspective

A large interventional trial, the Systolic Blood Pressure Intervention Trial sub-study termed Memory and Cognition in Decreased Hypertension (SPRINT-MIND), found reduced risk of cognitive impairment in older adults with intensive, relative to standard, blood-pressure-lowering targets (systolic BP < 120 vs. <140 mm Hg). In this perspective, we discuss key questions and make recommendations for clinical practice and for clinical trials, following SPRINT-MIND. Future trials should embody cognitive endpoints appropriate to the participant group, ideally with adaptive designs that ensure robust answers for cognitive and cardiovascular endpoints. Reliable data from diverse populations, including the oldest-old (age > 80 years), will maximize external validity and global implementation of trial findings. New biomarkers will improve phenotyping to stratify patients to optimal treatments. Currently no antihypertensive drug class stands out for dementia risk reduction. Multi-domain interventions, incorporating lifestyle change (exercise, diet) alongside medications, may maximize global impact. Given the low cost and wide availability of antihypertensive drugs, intensive BP reduction may be a cost-effective means to reduce dementia risk in diverse, aging populations worldwide.

Circadian dysfunction and Alzheimer's disease - An updated review

Alzheimer's disease (AD) is considered to be the most typical form of dementia that provokes irreversible cognitive impairment. Along with cognitive impairment, circadian rhythm dysfunction is a fundamental factor in aggravating AD. A link among circadian rhythms, sleep, and AD has been well-documented. The etiopathogenesis of circadian system disruptions and AD serves some general characteristics that also open up the possibility of viewing them as a mutually reliant path. In this review, we have focused on different factors that are related to circadian rhythm dysfunction. The various pathogenic factors, such as amyloid-beta, neurofibrillary tangles, oxidative stress, neuroinflammation, and circadian rhythm dysfunction may all contribute to AD. In this review, we also tried to focus on melatonin which is produced from the pineal gland and can be used to treat circadian dysfunction in AD. Aside from amyloid beta, tau pathology may have a notable influence on sleep. Conclusively, the center of this review is primarily based on the principal mechanistic complexities associated with circadian rhythm disruption, sleep deprivation, and AD, and it also emphasizes the potential therapeutic strategies to treat and prevent the progression of AD.

Effects of Dihydropyridines on the Motor and Cognitive Outcomes of Patients with Parkinson's Disease

BACKGROUND

Dihydropyridines (DHPs) may have neuroprotective effects against Parkinson's disease (PD).

OBJECTIVE

This study investigated the effects of DHPs on nigrostriatal dopaminergic denervation and longitudinal motor and cognitive outcomes in PD.

METHODS

We classified 476 patients with drug-naive PD who had undergone dopamine transporter imaging into three groups. They were selected according to a prior diagnosis of hypertension and use of DHPs and were matched using propensity scores: patients without hypertension (HTN-; n = 50) and patients with hypertension treated without DHP (HTN+/DHP-; n = 50) or with DHP (HTN+/DHP+; n = 50). Multiple linear regression and linear mixed model analyses were performed to determine intergroup differences in baseline dopamine transporter availability and longitudinal changes in the levodopa-equivalent dose, respectively. Using Kaplan-Meier analyses, we compared the risks of levodopa-induced dyskinesia, wearing off, and dementia-free survival during the 5.06 years of the mean follow-up period. The Cox regression model determined the independent effects of DHPs on dementia conversion.

RESULTS

Dopamine transporter availability in all striatal subregions was comparable between the HTN-, HTN+/DHP-, and HTN+/DHP+ groups. The risks of levodopa-induced dyskinesia and wearing off, as well as longitudinal changes in the levodopa-equivalent dose, did not differ between the groups. The HTN+/DHP+ group had a lower risk of developing dementia than the HTN+/DHP- (Bonferroni-corrected P_log-rank  = 0.036) group. The use of DHP was independently associated with a lower risk of dementia conversion after controlling for other antihypertensive drugs and confounding factors (hazard ratio, 0.242; 95% confidence interval, 0.087-0.668; P = 0.006).

CONCLUSIONS

DHPs may be associated with better long-term cognitive outcomes in hypertensive patients with PD. © 2023 International Parkinson and Movement Disorder Society.

The 2022 focused update of the 2018 Korean Hypertension Society Guidelines for the management of hypertension

Hypertension is the leading cause of death in human being, which shows high prevalence and associated complications that increase the mortality and morbidity. Controlling blood pressure (BP) is very important because it is well known that lowering high BP effectively improves patients' prognosis. This review aims to provide a focused update of the 2018 Korean Hypertension Society Guidelines for the management of hypertension. The importance of ambulatory BP and home BP monitoring was further emphasized not only for the diagnosis but also for treatment target. By adopting corresponding BPs, the updated guideline recommended out-of-office BP targets for both standard and intensive treatment. Based on the consensus on corresponding BPs and Systolic Blood Pressure Intervention Trial (SPRINT) revisit, the updated guidelines recommended target BP in high-risk patients below 130/80 mmHg and it applies to hypertensive patients with three or more additional cardiovascular risk factors, one or more risk factors with diabetes, or hypertensive patients with subclinical organ damages, coronary or vascular diseases, heart failure, chronic kidney disease with proteinuria, and cerebral lacunar infarction. Cerebral infarction and chronic kidney disease are also high-risk factors for cardiovascular disease. However, due to lack of evidence, the target BP was generally determined at < 140/90 mmHg in patients with those conditions as well as in the elderly. Updated contents regarding the management of hypertension in special situations are also discussed.

Influence of Baseline Diastolic Blood Pressure on the Effects of Systolic Blood Pressure Lowering on Cognitive Function in Type 2 Diabetes Mellitus

BACKGROUND

Lowering of systolic blood pressure (SBP) in patients with low diastolic blood pressure (DBP), can further lower DBP. This can potentially decrease cerebral perfusion and cognition. We examined the influence of baseline DBP on the effect of lowering SBP on cognition.

METHODS

This is a post hoc analysis of the Memory in Diabetes (MIND) substudy (N = 1,430) of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study (NCT00000620). Standard neuropsychological tests (Digit Symbol Substitution Test [DSST], Mini-Mental State Examination [MMSE], Rey Auditory Verbal Learning Test [RAVLT], and Stroop test) were performed at baseline and months 20 and 40. We compared the effects of intensive (goal SBP <120 mm Hg) vs. standard (goal SBP <140 mm Hg) SBP control on the changes in the 4 test scores from baseline to the averages of months 20 and 40 across the range of baseline DBP using cubic spline terms.

RESULTS

Mean age was 63 ± 6 years, 55% were women and 66% White. Participates with lower baseline DBP were older, had more cardiovascular events and a longer duration of diabetes. There was no difference in the change in DSST (-0.22; 95% CI -0.97, 0.52), MMSE (-0.14; 95% CI -0.34, 0.06), RAVLT (-0.12; 95% CI -0.29, 0.06), and Stroop interference (-0.47; 95% CI -1.76, 0.82) in the intensive vs. standard SBP intervention. There was no interaction between baseline DBP and change in scores with the SBP intervention.

CONCLUSIONS

Intensive SBP reduction does not adversely affect cognition, even in those with low baseline DBP.

Cognitive impairment in patients with heart failure: molecular mechanism and therapy

Heart failure (HF) is associated with multiple organ dysfunction and many comorbidities. Its incidence is high among the elderly and is a major health burden worldwide. Cognitive impairment (CI) is highly prevalent in older patients with HF, which is an abnormality in one or more of the items of cognition, attention, memory, language, psychomotor function, and visual spatial acuity. Studies have shown that the incidence of CI in HF patients is between 13 and 54%, and patients with both conditions have poor self-care ability and prognosis, as well as increased mortality rates. However, the mechanisms of CI development in HF patients are still unclear. In this review, we describe the epidemiology and risk factors as well as measures of improving CI in HF patients. We update the latest pathophysiological mechanisms related to the neurocognitive changes in HF patients, expounding on the mechanisms associated with the development of CI in HF patients.

Blood pressure lowering and prevention of dementia: an individual patient data meta-analysis

AIMS

Observational studies indicate U-shaped associations of blood pressure (BP) and incident dementia in older age, but randomized controlled trials of BP-lowering treatment show mixed results on this outcome in hypertensive patients. A pooled individual participant data analysis of five seminal randomized double-blind placebo-controlled trials was undertaken to better define the effects of BP-lowering treatment for the prevention of dementia.

METHODS AND RESULTS

Multilevel logistic regression was used to evaluate the treatment effect on incident dementia. Effect modification was assessed for key population characteristics including age, baseline systolic BP, sex, and presence of prior stroke. Mediation analysis was used to quantify the contribution of trial medication and changes in systolic and diastolic BP on risk of dementia. The total sample included 28 008 individuals recruited from 20 countries. After a median follow-up of 4.3 years, there were 861 cases of incident dementia. Multilevel logistic regression reported an adjusted odds ratio 0.87 (95% confidence interval: 0.75, 0.99) in favour of antihypertensive treatment reducing risk of incident dementia with a mean BP lowering of 10/4 mmHg. Further multinomial regression taking account of death as a competing risk found similar results. There was no effect modification by age or sex. Mediation analysis confirmed the greater fall in BP in the actively treated group was associated with a greater reduction in dementia risk.

CONCLUSION

The first single-stage individual patient data meta-analysis from randomized double-blind placebo-controlled clinical trials provides evidence to support benefits of antihypertensive treatment in late-mid and later life to lower the risk of dementia. Questions remain as to the potential for additional BP lowering in those with already well-controlled hypertension and of antihypertensive treatment commenced earlier in the life-course to reduce the long-term risk of dementia.

CLASSIFICATION OF EVIDENCE

Class I evidence in favour of antihypertensive treatment reducing risk of incident dementia compared with placebo.

Clinical impact of blood pressure on cardiovascular death in patients 80 years and older following acute myocardial infarction: a prospective cohort study

Numerous trials have shown that lowering blood pressure (BP) reduces cardiovascular risk and mortality, yet data about the impact of BP on cardiovascular death risk in patients aged ≥80 years with acute myocardial infarction (AMI) are sparse. This study explored the prognostic value of BP for cardiovascular death during the first 48 h after admission following AMI among patients aged ≥80 years. A total of 1005 patients ≥80 years with AMI were enrolled. Average BP parameters, including systolic, diastolic, and pulse BP, over the first 48 h after admission were calculated. The end point was cardiovascular death. Receiver operating curve (ROC) analysis was used to identify whether BP was relevant to cardiovascular death. The relationship between BP levels and cardiovascular death was evaluated by Cox regression models. ROC analysis showed that average diastolic blood pressure (aDBP), but not systolic and pulse BP, was relevant to cardiovascular death, and the optimal cutoff was 65 mmHg. During the 2.9-year follow-up, patients who died from a cardiovascular cause had lower aDBP levels than those who did not (p = 0.002). Patients with aDBP <65 mmHg had a 1.5-fold higher incidence of cardiovascular death than those with aDBP ≥65 mmHg (35.9% vs. 24.0%; p < 0.001). In multivariable regression analysis, low aDBP remained a strong and independent predictor of cardiovascular death (adjusted hazard ratio 1.907; 95% CI 1.303-2.792). aDBP was independently associated with cardiovascular death in patients aged ≥80 years with AMI, suggesting that aDBP may be a useful index to predict worse outcome in these patients.

Randomised controlled trials for the prevention of cognitive decline or dementia: A systematic review

Dementia prevention research has progressed rapidly in recent years, with publication of several large lifestyle intervention trials, and renewed interest in pharmacological interventions, notably for individuals with Alzheimer's disease biomarkers, warranting an updated review of results and methodology. We identified 112 completed trials testing the efficacy of single-domain pharmacological (n = 33, 29%), nutritional (n = 27, 24%), physical activity (n = 18, 16%) and cognitive stimulation (n = 13, 12%), or multidomain (n = 22, 20%) interventions on incident dementia, or a relevant intermediate marker (e.g. cognitive function, biomarkers or dementia risk scores) in people without dementia. The earliest trials tested pharmacological interventions or nutritional supplements, but lifestyle interventions predominated in the last decade. In total, 21 (19%) trials demonstrated a clear beneficial effect on the pre-specified primary outcome (or all co-primary outcomes), but only two (10%) were large-scale (testing blood pressure lowering (Syst-Eur) or multidomain (FINGER) interventions on incident dementia and cognitive change in cognitive function, respectively). Of the 116 ongoing trials, 40% (n = 46) are testing multidomain interventions. Recent methodological shifts concern target populations, primary outcome measures, and intervention design, but study design remains constant (parallel group randomised controlled trial). Future trials may consider using adaptive trials or interventions, and more targeted approaches, since certain interventions may be more effective in certain subgroups of the population, and at specific times in the life-course. Efforts should also be made to increase the representativeness and diversity of prevention trial populations.

Protofibrillar Amyloid Beta Modulation of Recombinant hCaV2.2 (N-Type) Voltage-Gated Channels

Cav2.2 channels are key regulators of presynaptic Ca²⁺ influx and their dysfunction and/or aberrant regulation has been implicated in many disease states; however, the nature of their involvement in Alzheimer's disease (AD) is less clear. In this short communication, we show that recombinant hCav2.2/b_1b/a₂d₁ channels are modulated by human synthetic AD-related protofibrillar amyloid beta Ab_1-42 peptides. Structural studies revealed a time-dependent increase in protofibril length, with the majority of protofibrils less than 100 nm at 24 h, while at 48 h, the majority were longer than 100 nm. Cav2.2 modulation by Ab_1-42 was different between a 'low' (100 nM) and 'high' (1 µM) concentration in terms of distinct effects on individual biophysical parameters. A concentration of 100 nM Ab_1-42 caused no significant changes in the measured biophysical properties of Cav2.2 currents. In contrast, 1 µM Ab_1-42 caused an inhibitory decrease in the current density (pA/pF) and maximum conductance (Gmax), and a depolarizing shift in the slope factor (k). These data highlight a differential modulation of Cav2.2 channels by the Ab_1-42 peptide. Discrete changes in the presynaptic Ca²⁺ flux have been reported to occur at an early stage of AD; therefore, this study reveals a potential mechanistic link between amyloid accumulation and Ca_v2.2 channel modulation.

The Correlation between Two Angiotensin-Converting Enzyme Inhibitor's Concentrations and Cognition

Both lisinopril and enalapril are angiotensin-converting enzyme (ACE) drugs and widely used in the treatment of hypertension. Enalapril does not cross the blood-brain barrier, but lisinopril is centrally active. Our goal was to find out if there was a link between the actual concentration of ACE inhibitors and cognition and if there was a detectable difference between the two types of ACE inhibitors. Asymptomatic, non-treated patients were diagnosed by screening and the hypertension was confirmed by ambulatory blood pressure monitoring (ABPM). A battery of cognitive tests was used to assess the impact of randomly assigning participants to receive either lisinopril or enalapril. All neurocognitive functions were measured, especially the most affected by conditions of compromised perfusion pressures, such as hypertension, which are attention and executive functions. The lisinopril concentration showed a significant inverse correlation with mosaic test (coeff. = -0.5779) and seemed to have a significant negative effect on perceptual motor skills (coeff. = -0.5779), complex attention (coeff. = -0.5104) and learning (coeff. = -0.5202). Compared with enalapril, lisinopril is less successful in improving the components of cognitive functions.

The relationship between isolated hypertension with brain volumes in UK Biobank

BACKGROUND

Hypertension is a well-established risk factor for cognitive impairment, brain atrophy, and dementia. However, the relationship of other types of hypertensions, such as isolated hypertension on brain health and its comparison to systolic-diastolic hypertension (where systolic and diastolic measures are high), is still relatively unknown. Due to its increased prevalence, it is important to investigate the impact of isolated hypertension to help understand its potential impact on cognitive decline and future dementia risk. In this study, we compared a variety of global brain measures between participants with isolated hypertension to those with normal blood pressure (BP) or systolic-diastolic hypertension using the largest cohort of healthy individuals.

METHODS

Using the UK Biobank cohort, we carried out a cross-sectional study using 29,775 participants (mean age 63 years, 53% female) with BP measurements and brain magnetic resonance imaging (MRI) data. We used linear regression models adjusted for multiple confounders to compare a variety of global, subcortical, and white matter brain measures. We compared participants with either isolated systolic or diastolic hypertension with normotensives and then with participants with systolic-diastolic hypertension.

RESULTS

The results showed that participants with isolated systolic or diastolic hypertension taking BP medications had smaller gray matter but larger white matter microstructures and macrostructures compared to normotensives. Isolated systolic hypertensives had larger total gray matter and smaller white matter traits when comparing these regions with participants with systolic-diastolic hypertension.

CONCLUSIONS

These results provide support to investigate possible preventative strategies that target isolated hypertension as well as systolic-diastolic hypertension to maintain brain health and/or reduce dementia risk earlier in life particularly in white matter regions.

Oral nimodipine treatment has no effect on amyloid pathology or neuritic dystrophy in the 5XFAD mouse model of amyloidosis

Dysregulation of calcium homeostasis has been hypothesized to play a role in Alzheimer's disease (AD) pathogenesis. Increased calcium levels can impair axonal transport, disrupt synaptic transmission, and ultimately lead to cell death. Given the potential role of calcium dyshomeostasis in AD, there is interest in testing the ability of already approved drugs targeting various calcium channels to affect amyloid pathology and other aspects of disease. The objective of this study was to test the effects of FDA-approved L-type calcium channel antagonist nimodipine on amyloid accumulation and dystrophic neurite formation in 5XFAD mice, a mouse model of amyloid pathology. 5XFAD transgenic mice and non-transgenic littermates were treated with vehicle or nimodipine-containing chow from two to eight months of age, then brains were harvested and amyloid pathology assessed by immunoblot and immunofluorescence microscopy analyses. Nimodipine was well tolerated and crossed the blood brain barrier, as expected, but there was no effect on Aβ accumulation or on the relative amount of neuritic dystrophy, as assessed by either immunoblot, dot blot or immunofluorescence imaging of Aβ42 and dystrophic neurite marker LAMP1. While we conclude that nimodipine treatment is not likely to improve amyloid pathology or decrease neuritic dystrophy in AD, it is worth noting that nimodipine did not worsen the phenotype suggesting its use is safe in AD patients.

Association between visit-to-visit blood pressure variability and risks of dementia in CKD patients: a nationwide observational cohort study

Background

The association between visit-to-visit blood pressure (BP) variability and dementia risk in chronic kidney disease (CKD) patients has rarely been studied.

Methods

In this retrospective observational study, individuals who received three or more general health screenings were identified in the nationwide database of Korea. Those with persistent non-dialysis-dependent CKD [estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² or dipstick albuminuria ≥1+] were included. The study exposure was systolic or diastolic BP variability, calculated as the variation independent of the mean and categorized into quartiles (Q4: the highest quartile; Q1: the lowest quartile). The risks of all-cause dementia, including Alzheimer's disease and vascular dementia, were analyzed by Cox regression adjusted for various clinical characteristics, including baseline BP and eGFR values.

Results

We included 103 139 CKD patients and identified 7574 (7%) dementia events, including 5911 (6%) Alzheimer's disease cases, 886 (1%) vascular dementia events and 777 (1%) cases categorized as other types of dementia. Higher systolic BP variability was significantly associated with higher risks of all-cause dementia {[Q4 versus Q1], hazard ratio [HR] 1.173 [95% confidence interval (CI) 1.102-1.249], P for trend < .001}. The results were also significant for the risk of Alzheimer's disease [HR 1.162 (95% CI 1.083-1.248), P < .001] and vascular dementia [HR 1.282 (95% CI 1.064-1.545), P = .039]. The results were similar when diastolic BP variability was the exposure, as high diastolic BP variability was significantly associated with higher risks of all-cause dementia [HR 1.191 (95% CI 1.117,1.270), P < .001].

Conclusions

Higher visit-to-visit BP variability is significantly associated with a higher risk of dementia in CKD patients.

Effect of a multi-domain lifestyle intervention on cardiovascular risk in older people: the FINGER trial

AIMS

Joint prevention of cardiovascular disease (CVD) and dementia could reduce the burden of both conditions. The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) demonstrated a beneficial effect on cognition (primary outcome) and we assessed the effect of this lifestyle intervention on incident CVD (pre-specified secondary outcome).

METHODS AND RESULTS

FINGER enrolled 1259 individuals aged 60-77 years (ClinicalTrials.gov NCT01041989). They were randomized (1:1) to a 2-year multi-domain intervention with diet, physical and cognitive activity, and vascular monitoring (n = 631), or general health advice (n = 628). National registries provided data on CVD including stroke, transient ischaemic attack (TIA), or coronary heart event. During an average of 7.4 years, 229 participants (18%) had at least one CVD diagnosis: 107 in the intervention group and 122 in the control group. The incidence of cerebrovascular events was lower in the intervention than the control group: hazard ratio (HR) for combined stroke/TIA was 0.71 [95% confidence interval (CI): 0.51-0.99] after adjusting for background characteristics. Hazard ratio for coronary events was 0.84 (CI: 0.56-1.26) and total CVD events 0.80 (95% CI: 0.61-1.04). Among those with history of CVD (n = 145), the incidence of both total CVD events (HR: 0.50, 95% CI: 0.28-0.90) and stroke/TIA (HR: 0.40, 95% CI: 0.20-0.81) was lower in the intervention than the control group.

CONCLUSION

A 2-year multi-domain lifestyle intervention among older adults was effective in preventing cerebrovascular events and also total CVD events among those who had history of CVD.

KEY QUESTION

Can a 2-year multi-domain lifestyle intervention, primarily designed for prevention of cognitive impairment, prevent new cardiovascular events among older adults over an extended follow-up?

KEY FINDING

Among the 1259 participants aged 60-77 years, the intervention resulted in 13-20% lower cardiovascular disease (CVD) event rates (unadjusted and adjusted analyses), but with large degree of uncertainty. Cerebrovascular event rates were lower but for total CVD only among those with earlier CVD events.

TAKE-HOME MESSAGE

A 2-year multi-domain lifestyle intervention among older adults was effective in preventing cerebrovascular events and also total CVD events among those with a history of CVD.

Trials and Treatments for Vascular Brain Health: Risk Factor Modification and Cognitive Outcomes

There is robust evidence linking vascular health to brain health, cognition, and dementia. In this article, we present evidence from trials of vascular risk factor treatment on cognitive outcomes. We summarize findings from randomized controlled trials of antihypertensives, lipid-lowering medications, diabetes treatments (including antidiabetic drugs versus placebo, and intensive versus standard glycemic control), and multidomain interventions (that target several domains simultaneously such as control of vascular and metabolic factors, nutrition, physical activity, and cognitive stimulation etc). We report that evidence on the efficacy of vascular risk reduction interventions is promising, but not yet conclusive, and several methodological limitations hamper interpretation. Evidence mainly comes from high-income countries and, as cognition and dementia have not been the primary outcomes of many trials, evaluation of cognitive changes have often been limited. As the cognitive aging process occurs over decades, it is unclear whether treatment during the late-life window is optimal for dementia prevention, yet older individuals have been the target of most trials thus far. Further, many trials have not been powered to explore interactions with modifiers such as age, race, and apolipoprotein E, even though sub-analyses from some trials indicate that the success of interventions differs depending on patient characteristics. Due to the complex multifactorial etiology of dementia, and variations in risk factors between individuals, multidomain interventions targeting several risk factors and mechanisms are likely to be needed and the long-term sustainability of preventive interventions will require personalized approaches that could be facilitated by digital health tools. This is especially relevant during the coronavirus disease 2019 (COVID-19) pandemic, where intervention strategies will need to be adapted to the new normal, when face-to-face engagement with participants is limited and public health measures may create changes in lifestyle that affect individuals’ vascular risk profiles and subsequent risk of cognitive decline.

Study Protocol of a Comprehensive Activity Promotion Program for the Prevention of Dementia: A Randomized Controlled Trial Protocol

BACKGROUND

Several technical devices are available to monitor and promote changes in behavior toward higher activity. In particular, smartphones are becoming the primary platform for recognizing human activity. However, the effects of behavior change techniques that promote physical, cognitive, and social activities on incident dementia in older adults remain unknown.

OBJECTIVES

This randomized controlled trial aims to examine the effects of behavior change techniques on the prevention of dementia among community-dwelling older adults using a smartphone as a behavior change tool.

DESIGN

A randomized controlled trial.

SETTING

Community in Japan.

PARTICIPANTS

The study cohort comprises 3,498 individuals, aged ≥60 years, randomized into two groups: the smartphone group (n = 1,749) and the control group (n = 1,749).

INTERVENTION

The smartphone group will be asked to use smartphone applications for at least 30 minutes daily to self-manage and improve their physical, cognitive, and social activities. The smartphone group will perform 60-minute group walking sessions using application-linked Nordic walking poles with cognitive stimulation twice a week during the intervention period. The walking poles are a dual-task exercise tool that works with a smartphone to perform cognitive tasks while walking, and the poles are equipped with switches to answer questions for simple calculation and memory tasks. The smartphone and control groups will receive lectures about general health that will be provided during the baseline and follow-up assessments.

MEASUREMENTS

Incident dementia will be detected using cognitive tests (at baseline, after 15 months, and after 30 months) and by preparing diagnostic monthly reports based on data from the Japanese Health Insurance System. Participants without dementia at baseline who will be diagnosed with dementia over the 30-month follow-up period will be considered to have incident dementia.

CONCLUSIONS

This study has the potential to provide the first evidence of the effectiveness of information communication technology and Internet of Things in incident dementia. If our trial results show a delayed dementia onset for self-determination interventions, the study protocol will provide a cost-effective and safe method for maintaining healthy cognitive aging.

Blood pressure screening in midlife aids in prediction of dementia later in life

BACKGROUND

There is substantial evidence that midlife hypertension is a risk factor for late life dementia. Our aim was to investigate if even high blood pressure at a single timepoint in midlife can predict an increased risk for all-cause dementia, Alzheimer's disease (AD), or vascular dementia (VaD) later in life.

METHODS

The community-based study population comprised 30,102 dementia-free individuals from the Westmannia Cardiovascular Risk Factors Study. The participants were aged 40 or 50 years when the health examination took place in 1990-2000. Diagnose registers from both hospitals and primary healthcare centers were used to identify individuals who after inclusion to the study developed dementia. The association between midlife high blood pressure (defined as systolic blood pressure >140 and/or diastolic blood pressure >90 mmHg) at a single timepoint and dementia was adjusted for age, gender, body mass index (BMI), fasting blood glucose, education, smoking, and physical activity level. Multivariate binary cox regression analyses were used.

RESULTS

After a mean follow-up time of 24 years resulting in 662,244 person/years, 761 (2.5%) individuals had been diagnosed with dementia. Midlife high blood pressure at a single timepoint predicted all-cause dementia (hazard ratio [HR]: 1.22, 95% confidence interval [CI]: 1.02-1.45) and VaD (HR: 2.10, 95% CI: 1.47-3.00) but not AD (HR: 1.06, 95% CI: 0.81-1.38).

CONCLUSION

This study suggests that even midlife high blood pressure at a single timepoint predicts all-cause dementia and more than doubles the risk for VaD later in life independently of established confounders. Even though there was no such association with AD, this strengthens the importance of midlife health examinations in order to identify individuals with hypertension and initiate treatment.

Vascular Cognitive Impairment (VCI)

Vascular cognitive impairment (VCI) is predominately caused by vascular risk factors and cerebrovascular disease. VCI includes a broad spectrum of cognitive disorders, from mild cognitive impairment to vascular dementia caused by ischemic or hemorrhagic stroke, and vascular factors alone or in a combination with neurodegeneration including Alzheimer's disease (AD) and AD-related dementia. VCI accounts for at least 20-40% of all dementia diagnosis. Growing evidence indicates that cerebrovascular pathology is the most important contributor to dementia, with additive or synergistic interactions with neurodegenerative pathology. The most common underlying mechanism of VCI is chronic age-related dysregulation of CBF, although other factors such as inflammation and cardiovascular dysfunction play a role. Vascular risk factors are prevalent in VCI and if measured in midlife they predict cognitive impairment and dementia in later life. Particularly, hypertension, high cholesterol, diabetes, and smoking at midlife are each associated with a 20 to 40% increased risk of dementia. Control of these risk factors including multimodality strategies with an inclusion of lifestyle modification is the most promising strategy for treatment and prevention of VCI. In this review, we present recent developments in age-related VCI, its mechanisms, diagnostic criteria, neuroimaging correlates, vascular risk determinants, and current intervention strategies for prevention and treatment of VCI. We have also summarized the most recent and relevant literature in the field of VCI.

Evaluation of High Cholesterol and Risk of Dementia and Cognitive Decline in Older Adults Using Individual Patient Meta-Analysis

INTRODUCTION

Although increased cholesterol level has been acknowledged as a risk factor for dementia, evidence synthesis based on published data has yielded mixed results. This is especially relevant in older adults where individual studies report non-linear relationships between cholesterol and cognition and, in some cases, find higher cholesterol associated with a lower risk of subsequent cognitive decline or dementia. Prior evidence synthesis based on published results has not allowed us to focus on older adults or to standardize analyses across studies. Given our ageing population, an increased risk of dementia in older adults, and the need for proportionate treatment in this age group, an individual participant data (IPD) meta-analysis is timely.

METHOD

We combined data from 8 studies and over 21,000 participants aged 60 years and over in a 2-stage IPD to examine the relationship between total, high-density, and low-density lipoprotein (HDL and LDL) cholesterol and subsequent incident dementia or cognitive decline, with the latter categorized using a reliable change index method.

RESULTS

Meta-analyses found no relationship between total, HDL, or LDL cholesterol (per millimoles per litre increase) and risk of cognitive decline in this older adult group averaging 76 years of age. For total cholesterol and cognitive decline: odds ratio (OR) 0.93 (95% confidence interval [CI] 0.86: 1.01) and for incident dementia: OR 1.01 [95% CI 0.89: 1.13]. This was not altered by rerunning the analyses separately for statin users and non-users or by the presence of an APOE e4 allele.

CONCLUSION

There were no clear consistent relationships between cholesterol and cognitive decline or dementia in this older adult group, nor was there evidence of effect modification by statin use. Further work is needed in younger populations to understand the role of cholesterol across the life-course and to identify any relevant intervention points. This is especially important if modification of cholesterol is to be further evaluated for its potential influence on risk of cognitive decline or dementia.

Can platelet activation result in increased plasma Aβ levels and contribute to the pathogenesis of Alzheimer's disease?

One of the central lesions in the brain of subjects with Alzheimer's disease (AD) is represented by aggregates of β-amyloid (Aβ), a peptide of 40-42 amino acids derived from the amyloid precursor protein (APP). The reasons why Aβ accumulates in the brain of individuals with sporadic forms of AD are unknown. Platelets are the primary source of circulating APP and, upon activation, can secrete significant amounts of Aβ into the blood which can be actively transported to the brain across the blood-brain barrier and promote amyloid deposition. Increased platelet activity can stimulate platelet adhesion to endothelial cells, trigger the recruitment of leukocytes into the vascular wall and cause perivascular inflammation, which can spread inflammation in the brain. Neuroinflammation is fueled by activated microglial cells and reactive astrocytes that release neurotoxic cytokines and chemokines. Platelet activation is also associated with the progression of carotid artery disease resulting in an increased risk of cerebral hypoperfusion which may also contribute to the AD neurodegenerative process. Platelet activation may thus be a pathophysiological mechanism of AD and for the strong link between AD and cerebrovascular diseases. Interfering with platelet activation may represent a promising potential adjunct therapeutic approach for AD.

Systems Biology and Chemoinformatics-Based Strategies to Explore the Biological Mechanism of Fugui Wenyang Decoction in Treating Vascular Dementia Rats

OBJECTIVE

To explore the biological mechanism of Fugui Wenyang Decoction (FGWYD) in treating vascular dementia (VD) rats based on systems pharmacology, proteomics, and a multidirectional pharmacology integration strategy.

METHODS

Chemoinformatics was utilized to construct and analyze the FGWYD-VD protein-protein interaction (PPI) network. Then, the total protein in the brain tissue of the infarcted side of the rat was extracted for protein identification, pattern identification, and protein quantitative analysis. The differentially expressed proteins are analyzed by bioinformatics. Finally, the important proteins in the oxidative stress-related biological process proteins and indicators were detected through experimental pharmacology to verify the findings of systems biology and chemoinformatics.

RESULTS

There were a total of 73 FGWYD components with 245 FGWYD and 145 VD genes. The results of GO enrichment analysis and pathway enrichment analysis showed that MBHD may regulate the inflammation module, oxidative stress, the synaptic plasticity regulation module, and the neuronal apoptosis section module. Compared with the sham operation group, there were 23 upregulated proteins and 17 downregulated proteins in the model group (P < 0.05). Compared with the model group, there were 16 upregulated proteins and 10 downregulated proteins in the FGWYD group (P < 0.05). Bioinformatics analysis shows that those proteins were closely related to processes such as inflammation, oxidative stress, neuronal apoptosis, neuronal growth and differentiation, signaling pathways, and transcriptional regulation. Multidirectional pharmacology further verified the neuroprotective mechanism of the Nrf2/HO-1 pathway in FGWYD treatment of VD.

CONCLUSION

The mechanism of FGWYD in the treatment of VD may be related to inflammation, oxidative stress, angiogenesis, and neuronal apoptosis.

Hypertension-induced cognitive impairment: from pathophysiology to public health

Hypertension affects two-thirds of people aged >60 years and significantly increases the risk of both vascular cognitive impairment and Alzheimer's disease. Hypertension compromises the structural and functional integrity of the cerebral microcirculation, promoting microvascular rarefaction, cerebromicrovascular endothelial dysfunction and neurovascular uncoupling, which impair cerebral blood supply. In addition, hypertension disrupts the blood-brain barrier, promoting neuroinflammation and exacerbation of amyloid pathologies. Ageing is characterized by multifaceted homeostatic dysfunction and impaired cellular stress resilience, which exacerbate the deleterious cerebromicrovascular effects of hypertension. Neuroradiological markers of hypertension-induced cerebral small vessel disease include white matter hyperintensities, lacunar infarcts and microhaemorrhages, all of which are associated with cognitive decline. Use of pharmaceutical and lifestyle interventions that reduce blood pressure, in combination with treatments that promote microvascular health, have the potential to prevent or delay the pathogenesis of vascular cognitive impairment and Alzheimer's disease in patients with hypertension.

Preventing Alzheimer's disease within reach by 2025: Targeted-risk-AD-prevention (TRAP) strategy

INTRODUCTION

Alzheimer's disease (AD) is a progressive neurodegenerative disease that currently affects 6.2 million people in the United States and is projected to impact 12.7 million worldwide in 2050 with no effective disease-modifying therapeutic or cure. In 2011 as part of the National Alzheimer's Project Act, the National Plan to Address Alzheimer's Disease was signed into law which proposed to effectively prevent AD by 2025, which is rapidly approaching. The preclinical phase of AD can begin 20 years prior to diagnosis, which provides an extended window for preventive measures that would exert a transformative impact on incidence and prevalence of AD.

METHODS

A novel combination of text-mining and natural language processing strategies to identify (1) AD risk factors, (2) therapeutics that can target risk factor pathways, and (3) studies supporting therapeutics in the PubMed database was conducted. To classify the literature relevant to AD preventive strategies, a relevance score (RS) based on STRING (search tool for the retrieval of interacting genes/proteins) score for protein-protein interactions and a confidence score (CS) on Bayesian inference were developed. To address mechanism of action, network analysis of protein targets for effective drugs was conducted. Collectively, the analytic approach, referred to as a targeted-risk-AD-prevention (TRAP) strategy, led to a ranked list of candidate therapeutics to reduce AD risk.

RESULTS

Based on TRAP mining of 9625 publications, 364 AD risk factors were identified. Based on risk factor indications, 629 Food and Drug Administration-approved drugs were identified. Computation of ranking scores enabled identification of 46 relevant high confidence (RS & CS > 0.7) drugs associated with reduced AD risk. Within these candidate therapeutics, 16 had more than one clinical study supporting AD risk reduction. Top-ranked therapeutics with high confidence emerged within lipid-lowering, anti-inflammatory, hormone, and metabolic-related drug classes.

DISCUSSION

Outcomes of our novel bioinformatic strategy support therapeutic targeting of biological mechanisms and pathways underlying relevant AD risk factors with high confidence. Early interventions that target pathways associated with increased risk of AD have the potential to support the goal of effectively preventing AD by 2025.

Arterial hypertension and antihypertensive therapy in older patients. The agreed opinion of experts from the Russian Association of Gerontologists and Geriatricians, the Antihypertensive League, the National Society for Preventive Cardiology

High blood pressure is a risk factor for cardiovascular morbidity and mortality, as well as cognitive decline and loss of autonomy in the elderly and old age. Randomized clinical trials (RCTs) in populations of older patients living at home with low comorbidity and preserved autonomy indicate the benefit of lowering elevated blood pressure in patients over 80 years of age. Older patients with senile asthenia, loss of autonomy and other geriatric problems were excluded from RCTs, and observational studies in these groups of patients indicate an increase in morbidity and mortality with lower blood pressure and antihypertensive therapy. Obviously, in very elderly patients, a universal strategy for the treatment of arterial hypertension cannot be applied due to the significant heterogeneity of their functional status. The geriatric approach to the management of arterial hypertension in older patients involves an assessment of the functional status, the presence of senile asthenia, and the degree of autonomy for the choice of antihypertensive therapy tactics.

Cerebrovascular Contributions to Neurocognitive Disorders in People Living With HIV

BACKGROUND

To investigate a comprehensive array of magnetic resonance imaging (MRI)-based biomarkers of cerebrovascular disease (CVD) in a cohort of people living with HIV (PLWH) and relate these imaging biomarkers to cognition.

SETTINGS

Cross-sectional, community-based study.

METHODS

Participants were PLWH in New York City, aged 50 years or older. They underwent a brain magnetic resonance angiography or MRI to ascertain 7 MRI markers of CVD: silent brain infarcts, dilated perivascular spaces, microhemorrhages, white matter hyperintensity volume, white matter fractional anisotropy and mean diffusivity (measures of white matter integrity), and intracranial large artery stenosis. Participants underwent a battery of neurocognitive tests to obtain individual and global cognitive scores representative of various aspects of cognition.

RESULTS

We included 85 participants (mean age 60 ± 6 years, 48% men, 78% non-Hispanic Black), most of them with well-controlled HIV (75% with CD4 cell count > 200 cells/mm3 and viral load < 400 copies/mL at or near the time of the MRI scan). Silent brain infarcts, intracranial large artery stenosis, and poor white matter integrity were associated with poorer performance in at least one cognitive domain, but the sum of these 3 MRI markers of CVD was associated with lower working memory (B = -0.213, P = 0.028), list learning (B = -0.275, P = 0.019), and global cognition (B = -0.129, P = 0.007).

CONCLUSIONS

We identified silent brain infarcts, intracranial large artery stenosis, and poor white matter integrity as exposures that may be modifiable and may, therefore, influence cognitive decline. In addition, these MRI markers of CVD may help in identifying PLWH at higher risk of cognitive decline, which may be more amenable to targeted therapies.

Long-term effect of masked hypertension management on cognitive functions in geriatric age: geriatric MASked hypertension and cognition follow-up study (G-MASH-cog MONITOR)

OBJECTIVES

Masked hypertension, defined as nonelevated clinic blood pressure with elevated out of clinic blood pressure, has been associated with increased cardiovascular events, mortality and cognitive impairment. No evidence exists regarding the effect of treating masked hypertension. In this study, we followed-up the patients in the G-MASH-cog study for 1 year and aimed to examine the effect of the management of masked hypertension on cognitive functions.

METHODS

The G-MASH-cog study participants were followed-up for 1 year. In masked hypertensive individuals, lifestyle modification and antihypertensive treatment (perindopril or amlodipine) were initiated for blood pressure control. Measurements of cognitive tests and ambulatory blood pressure monitoring at baseline and at 1-year follow-up were compared.

RESULTS

A total of 61 patients (30 in masked hypertension group; 31 in normotensive group) were included. Mean age was 72.3 ± 5.1 and 59% of the participants were female. Compared with baseline ambulatory blood pressure measurement results, patients with masked hypertension had significantly lower ambulatory blood pressure measurement results after 1-year follow-up. The quick mild cognitive impairment test (Q-MCI-TR) score increased with antihypertensive treatment (Q-MCI score at baseline = 41(19-66.5), at 1 year = 45.5 (22-70), P = 0.005) in masked hypertensive patients. In the final model of the mixed-effects analysis, when adjusted for covariates, interaction effect of the masked hypertension treatment with time was only significant in influencing the changes in Q-MCI scores over time in patients aged between 65 and 74 years (P = 0.002).

CONCLUSIONS

Treatment of masked hypertension in older adults was associated with improvement in cognitive functions.

The Insular Cortex, Alzheimer Disease Pathology, and Their Effects on Blood Pressure Variability

Recent findings indicate that the human cardiovascular system is regulated by a cortical network comprised of the insular cortex (Ic), anterior cingulate gyrus, and amygdala which is necessary for the regulation of the central autonomic network system. Alzheimer disease (AD) affects the Ic at a preclinical stage. The pathology of AD at the Ic is suggested to predispose the cardiovascular system to detrimental changes such as increased blood pressure variability (BPV). In this review article, we focus on the physiology of the Ic in the relationship between the central autonomic network and BPV. We provide a summary of the published evidence regarding the relationship between Ic damage and exaggerated BPV in the context of AD pathology.

Oxidative Stress in the Pathogenesis of Alzheimer's Disease and Cerebrovascular Disease with Therapeutic Implications

The significant gain in life expectancy led to an increase in the incidence and prevalence of dementia. Although vascular risk factors have long and repeatedly been shown to increase the risk of Alzheimer's Disease (AD), translating these findings into effective preventive measures has failed. In addition, the finding that incident ischemic stroke approximately doubles the risk of a patient to develop AD has been recently reinforced. Current knowledge and pathogenetic hypotheses of AD are discussed. The implication of oxidative stress in the development of AD is reviewed, with special emphasis on its sudden burst in the setting of acute ischemic stroke and the possible link between this increase in oxidative stress and consequent cognitive impairment. Current knowledge and future directions in the prevention and treatment of AD are discussed outlining the hypothesis of a possible beneficial effect of antioxidant treatment in acute ischemic stroke in delaying the onset/progression of dementia.

Effects of Antihypertensive Drugs on Cognitive Function in Elderly Patients with Hypertension: A Review

Hypertension is a common comorbidity that contributes to the development of various cardiovascular disorders in elderly patients. Moreover, hypertension has been associated with cognitive decline and dementia. Cognitive impairment leads to increased morbidity and mortality in elderly patients with hypertension. However, previous studies investigating the association between blood pressure (BP), BP variability (BPV), and antihypertensive drug use and the risk of cognitive impairment in elderly patients with hypertension have reported inconsistent findings. Given the global burden of hypertension, the aging population, and the low quality of life associated with cognitive impairment, a more comprehensive understanding of the association between hypertension and cognitive decline is needed. In this review, we summarized the current preclinical evidence and clinical research regarding the association of BP control, BPV, and antihypertensive drug use and cognitive function. We particularly focused on the differences among categories of antihypertensive drugs. We concluded that the correlation of BP and risk of cognitive function is non-linear and dependent on a patient’s age. Intensive BP control is generally not recommended, particularly for the oldest-old. Increased BPV and characteristics of orthostatic hypotension in the elderly also increase the risk of cognitive decline. The current evidence does not support one category of antihypertensive drugs as superior to others for preventing dementia in elderly patients with hypertension.

Pharmacological treatment of hypertension in people without prior cerebrovascular disease for the prevention of cognitive impairment and dementia

BACKGROUND

This is an update of a Cochrane Review first published in 2006 (McGuinness 2006), and previously updated in 2009 (McGuinness 2009). Hypertension is a risk factor for dementia. Observational studies suggest antihypertensive treatment is associated with lower incidences of cognitive impairment and dementia. There is already clear evidence to support the treatment of hypertension after stroke.

OBJECTIVES

To assess whether pharmacological treatment of hypertension can prevent cognitive impairment or dementia in people who have no history of cerebrovascular disease.

SEARCH METHODS

We searched the Specialised Register of the Cochrane Dementia and Cognitive Improvement Group, CENTRAL, MEDLINE, Embase, three other databases, as well as many trials registries and grey literature sources, most recently on 7 July 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which pharmacological interventions to treat hypertension were given for at least 12 months. We excluded trials of pharmacological interventions to lower blood pressure in non-hypertensive participants. We also excluded trials conducted solely in people with stroke.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We collected information regarding incidence of dementia, cognitive decline, change in blood pressure, adverse effects and quality of life. We assessed the certainty of evidence using GRADE.

MAIN RESULTS

We included 12 studies, totaling 30,412 participants, in this review. Eight studies compared active treatment with placebo. Of the four non-placebo-controlled studies, two compared intensive versus standard blood pressure reduction. The two final included studies compared different classes of antihypertensive drug. Study durations varied from one to five years. The combined result of four placebo-controlled trials that reported incident dementia indicated no evidence of a difference in the risk of dementia between the antihypertensive treatment group and the placebo group (236/7767 versus 259/7660, odds ratio (OR) 0.89, 95% confidence interval (CI) 0.72 to 1.09; very low certainty evidence, downgraded due to study limitations and indirectness). The combined results from five placebo-controlled trials that reported change in Mini-Mental State Examination (MMSE) may indicate a modest benefit from antihypertensive treatment (mean difference (MD) 0.20, 95% CI 0.10 to 0.29; very low certainty evidence, downgraded due to study limitations, indirectness and imprecision). The certainty of evidence for both cognitive outcomes was downgraded on the basis of study limitations and indirectness. Study durations were too short, overall, to expect a significant difference in dementia rates between groups. Dementia and cognitive decline were secondary outcomes for most studies. Additional sources of bias include: the use of antihypertensive medication by the placebo group in the placebo-controlled trials; failure to reach recruitment targets; and early termination of studies on safety grounds. Meta-analysis of the placebo-controlled trials reporting results found a mean change in systolic blood pressure of -9.25 mmHg (95% CI -9.73, -8.78) between treatment (n = 8973) and placebo (n = 8820) groups, and a mean change in diastolic blood pressure of -2.47 mmHg (95% CI -2.70, -2.24) between treatment (n = 7700) and placebo (n = 7509) groups (both low certainty evidence downgraded on the basis of study limitations and inconsistency). Three trials - SHEP 1991, LOMIR MCT IL 1996 and MRC 1996 - reported more withdrawals due to adverse events in active treatment groups than placebo groups. Participants on active treatment in Syst Eur 1998 were less likely to discontinue treatment due to side effects, and participants on active treatment in HYVET 2008 reported fewer 'serious adverse events' than in the placebo group. There was no evidence of a difference in withdrawals rates between groups in SCOPE 2003, and results were unclear for Perez Stable 2000 and Zhang 2018. Heterogeneity precluded meta-analysis. Five of the placebo-controlled trials provided quality of life (QOL) data. Heterogeneity again precluded meta-analysis. SHEP 1991, Syst Eur 1998 and HYVET 2008 reported no evidence of a difference in QOL measures between active treatment and placebo groups over time. The SCOPE 2003 sub-study (Degl'Innocenti 2004) showed a smaller drop in QOL measures in the active treatment compared to the placebo group. LOMIR MCT IL 1996 reported an improvement in a QOL measure at twelve months in one active treatment group and deterioration in another.

AUTHORS' CONCLUSIONS

High certainty randomised controlled trial evidence regarding the effect of hypertension treatment on dementia and cognitive decline does not yet exist. The studies included in this review provide low certainty evidence (downgraded primarily due to study limitations and indirectness) that pharmacological treatment of hypertension, in people without prior cerebrovascular disease, leads to less cognitive decline compared to controls. This difference is below the level considered clinically significant. The studies included in this review also provide very low certainty evidence that pharmacological treatment of hypertension, in people without prior cerebrovascular disease, prevents dementia.

Deciphering the Interacting Mechanisms of Circadian Disruption and Alzheimer's Disease

Alzheimer's disease (AD) is one of the crucial causative factors for progressive dementia. Neuropathologically, AD is characterized by the extracellular accumulation of amyloid beta plaques and intracellular neurofibrillary tangles in cortical and limbic regions of the human brain. The circadian system is one of the many affected physiological processes in AD, the dysfunction of which may reflect in the irregularity of the sleep/wake cycle. The interplay of circadian and sleep disturbances inducing AD progression is bidirectional. Sleep-associated pathological alterations are frequently evident in AD. Understanding the interrelation between circadian disruption and AD may allow for earlier identification of AD pathogenesis as well as better suited approaches and potential therapies to combat dementia. In this article, we examine the existing literature related to the molecular mechanisms of the circadian clock and interacting mechanisms of circadian disruption and AD pathogenesis.

Calcium channel blockers, survival and ischaemic stroke in patients with dementia: a Swedish registry study

BACKGROUND

The effect of calcium channel blockers (CCB) on mortality and ischaemic stroke risk in dementia patients is understudied.

OBJECTIVES

To calculate the risk of death and ischaemic stroke in dementia patients treated with CCBs, considering individual agents and dose response.

METHODS

Longitudinal cohort study with 18 906 hypertensive dementia patients from the Swedish Dementia Registry (SveDem), 2008-2014. Other Swedish national registries contributed information on comorbidities, dispensed medication and outcomes. Individual CCB agents and cumulative defined daily doses (cDDD) were considered.

RESULTS

In patients with hypertension and dementia, nifedipine was associated with increased mortality risk (aHR 1.32; CI 1.01-1.73; P < 0.05) compared to non-CCB users. Patients diagnosed with Alzheimer's dementia (AD) or dementia with Lewy bodies/Parkinson's disease dementia (DLB-PDD) taking amlodipine had lower mortality risk (aHR, 0.89; CI, 0.80-0.98; P < 0.05 and aHR 0.58; CI, 0.38-0.86; P < 0.01, respectively), than those taking other CCBs. Amlodipine was associated with lower stroke risk in patients with Alzheimer's dementia compared to other CCBs (aHR 0.63; CI, 0.44-0.89; P < 0.05). Sensitivity analyses with propensity score-matched cohorts repeated the results for nifedipine (aHR 1.35; 95% CI, 1.02-1.78; P < 0.05) and amlodipine in AD (aHR, 0.87; CI, 0.78-0.97; P < 0.05) and DLB-PDD (aHR, 0.56, 95%CI, 0.37-0.85; P < 0.05).

CONCLUSION

Amlodipine was associated with reduced mortality risk in dementia patients diagnosed with AD and DLB-PDD. AD patients using amlodipine had a lower risk of ischaemic stroke compared to other CCB users.

Pharmacological Treatment of Vascular Dementia: A Molecular Mechanism Perspective

Vascular dementia (VaD) is a neurodegenerative disease, with cognitive dysfunction attributable to cerebrovascular factors. At present, it is the second most frequently occurring type of dementia in older adults (after Alzheimer's disease). The underlying etiology of VaD has not been completely elucidated, which limits its management. Currently, there are no approved standard treatments for VaD. The drugs used in VaD are only suitable for symptomatic treatment and cannot prevent or reduce the occurrence and progression of VaD. This review summarizes the current status of pharmacological treatment for VaD, from the perspective of the molecular mechanisms specified in various pathogenic hypotheses, including oxidative stress, the central cholinergic system, neuroinflammation, neuronal apoptosis, and synaptic plasticity. As VaD is a chronic cerebrovascular disease with multifactorial etiology, combined therapy, targeting multiple pathophysiological factors, may be the future trend in VaD.

Antihypertensive Medication Classes and the Risk of Dementia: A Systematic Review and Network Meta-Analysis

OBJECTIVES

To systematically review and synthesize the evidence on differential associations between antihypertensive medication (AHM) classes and the risk of incident dementia.

DESIGN

Systematic review and random effects frequentist network meta-analysis. Embase, MEDLINE, and the Cochrane library were searched from origin to December 2019.

SETTING AND PARTICIPANTS

Randomized controlled trials (RCTs) and prospective cohort studies that compared associations of different AHM classes with incident all-cause dementia and/or Alzheimer's disease over at least 1 year of follow-up.

MEASURES

All cause dementia and/or Alzheimer's disease.

RESULTS

Fifteen observational studies and 7 RCTs were included. Data on AHM classes were available for 649,790 participants and dementia occurred in 19,600 (3.02%). Network meta-analysis showed that in observational studies, treatment with either calcium channel blockers (CCBs) or angiotensin II receptor blockers (ARBs) was associated with lower dementia risks than treatment with other antihypertensives: CCBs vs angiotensin converting enzyme inhibitors (ACE inhibitors) (HR=0.84, 95% CI 0.74-0.95), beta blockers (HR=0.83, 95% CI 0.73-0.95) and diuretics (HR=0.89, 95% CI 0.78-1.01) and ARBs vs ACE inhibitors (HR=0.88, 95% CI 0.81-0.97), beta blockers (HR=0.87, 95% CI 0.77-0.99), and diuretics (HR=0.93, 95% CI 0.83-1.05). There were insufficient RCTs to create a robust network based on randomized data alone.

CONCLUSIONS AND IMPLICATIONS

Recommending CCBs or ARBs as preferred first-line antihypertensive treatment may significantly reduce the risk of dementia. If corroborated in a randomized setting, these findings reflect a low-cost and scalable opportunity to reduce dementia incidence worldwide.

The Interactions Between Alzheimer's Disease and Major Depression: Role of Ca2+ Channel Blockers and Ca2+/cAMP Signalling

BACKGROUND

The interactions between Alzheimer's Disease (AD) and major depression can be translated into clinical data showing that depressive patients have had an enhanced risk for developing AD (later in life). The cellular mechanisms involved in these interactions remain under intensive debate in the literature. In addition, the role of a Ca²⁺ homeostasis dysregulation in the pathogenesis of neurodegenerative diseases, like AD, and major depression has been under intensive discussion.

OBJECTIVE

Thus, revealing the interplay between AD and major depression may provide novel insights into the pathogenesis of these diseases.

METHODS

Publications involving Ca²⁺ signalling pathways, AD, and major depression (alone or combined) were collected by searching multiple databases to find the maximum number of relevant citations (using a search strategy with high sensitivity for studies of etiology).

RESULTS

Ca²⁺ Channel Blockers (CCBs), classically prescribed for hypertensive patients, have been demonstrating neuroprotective effects, such as decreasing the incidence of AD in hypertensive patients, including alleviating major depression symptoms. A mechanism under debate is focused on the restoration of the Ca²⁺ homeostasis. Indeed, previous studies of our own have correlated Ca²⁺ and cAMP signalling pathways (Ca²⁺/cAMP signalling) in controlling both the neurotransmitter release and neuronal death. These studies also observed that CCBs can affect Ca²⁺/cAMP signalling.

CONCLUSION

This review discussed the plausible role of Ca²⁺/cAMP signalling in the neuroprotective effects of CCBs, including the participation of Ca²⁺/cAMP signalling in the interactions between major depression and AD. Considering both AD and major depression have become highly prevalent medical problems in the world, the comprehension of the interactions between these diseases could improve drug development.

The neuroimaging of neurodegenerative and vascular disease in the secondary prevention of cognitive decline

Structural brain changes indicative of dementia occur up to 20 years before the onset of clinical symptoms. Efforts to modify the disease process after the onset of cognitive symptoms have been unsuccessful in recent years. Thus, future trials must begin during the preclinical phases of the disease before symptom onset. Age related cognitive decline is often the result of two coexisting brain pathologies: Alzheimer’s disease (amyloid, tau, and neurodegeneration) and vascular disease. This review article highlights some of the common neuroimaging techniques used to visualize the accumulation of neurodegenerative and vascular pathologies during the preclinical stages of dementia such as structural magnetic resonance imaging, positron emission tomography, and white matter hyperintensities. We also describe some emerging neuroimaging techniques such as arterial spin labeling, diffusion tensor imaging, and quantitative susceptibility mapping. Recent literature suggests that structural imaging may be the most sensitive and cost-effective marker to detect cognitive decline, while molecular positron emission tomography is primarily useful for detecting disease specific pathology later in the disease process. Currently, the presence of vascular disease on magnetic resonance imaging provides a potential target for optimizing vascular risk reduction strategies, and the presence of vascular disease may be useful when combined with molecular and metabolic markers of neurodegeneration for identifying the risk of cognitive impairment.

The Links between Cardiovascular Diseases and Alzheimer's Disease

The root cause of non-inherited Alzheimer's disease (AD) remains unknown despite hundreds of research studies performed to attempt to solve this problem. Since proper prophylaxis remains the best strategy, many scientists have studied the risk factors that may affect AD development. There is robust evidence supporting the hypothesis that cardiovascular diseases (CVD) may contribute to AD progression, as the diseases often coexist. Therefore, a lack of well-defined diagnostic criteria makes studying the relationship between AD and CVD complicated. Additionally, inflammation accompanies the pathogenesis of AD and CVD, and is not only a consequence but also implicated as a significant contributor to the course of the diseases. Of note, АроЕε4 is found to be one of the major risk factors affecting both the cardiovascular and nervous systems. According to genome wide association and epidemiological studies, numerous common risk factors have been associated with the development of AD-related pathology. Furthermore, the risk of developing AD and CVDs appears to be increased by a wide range of conditions and lifestyle factors: hypertension, dyslipidemia, hypercholesterolemia, hyperhomocysteinemia, gut/oral microbiota, physical activity, and diet. This review summarizes the literature and provides possible mechanistic links between CVDs and AD.

The relationship between heart disease and cognitive impairment

Neurodegenerative dementias, such as Alzheimer's disease, and vascular cognitive impairment were once considered unrelated processes. Emerging evidence, however, shows that both conditions often coexist and that vascular risk factors in midlife predispose to the development of cognitive decline later in older adults. In addition, recent advanced in basic science research have elucidated key underpinnings of this association. In this chapter, we review the clinical and basic science data that explain the relationship between vascular risk factors, heart disease, and cognitive decline.