Hypertension-induced cognitive impairment: from pathophysiology to public health

Cognitive impairment in cerebral small vessel disease induced by hypertension

ABSTRACT

Hypertension is a primary risk factor for the progression of cognitive impairment caused by cerebral small vessel disease, the most common cerebrovascular disease. However, the causal relationship between hypertension and cerebral small vessel disease remains unclear. Hypertension has substantial negative impacts on brain health and is recognized as a risk factor for cerebrovascular disease. Chronic hypertension and lifestyle factors are associated with risks for stroke and dementia, and cerebral small vessel disease can cause dementia and stroke. Hypertension is the main driver of cerebral small vessel disease, which changes the structure and function of cerebral vessels via various mechanisms and leads to lacunar infarction, leukoaraiosis, white matter lesions, and intracerebral hemorrhage, ultimately resulting in cognitive decline and demonstrating that the brain is the target organ of hypertension. This review updates our understanding of the pathogenesis of hypertension-induced cerebral small vessel disease and the resulting changes in brain structure and function and declines in cognitive ability. We also discuss drugs to treat cerebral small vessel disease and cognitive impairment.

Hypertension Impacts the Oscillatory Dynamics Serving the Encoding Phase of Verbal Working Memory

BACKGROUND

Chronic hypertension is known to be a major contributor to cognitive decline, with executive function and working memory being among the domains most commonly affected. Despite the growing literature on such dysfunction in patients with hypertension, the underlying neural processes are poorly understood.

METHODS

In this cross-sectional study, we examine these neural processes by having participants with controlled hypertension, uncontrolled hypertension, and healthy controls perform a verbal working memory task during magnetoencephalography. Neural oscillations associated with the encoding and maintenance components of the working memory task were imaged and statistically evaluated among the 3 groups.

RESULTS

Differences related to hypertension emerged during the encoding phase, where the hypertension groups exhibited weaker α-β oscillatory responses compared with controls in the left parietal cortices, whereas such oscillatory activity differed between the 2 hypertension groups in the right prefrontal regions. Importantly, these neural responses in the prefrontal and parietal cortices during encoding were also significantly associated with behavioral performance across all participants.

CONCLUSIONS

Overall, our data suggest that hypertension is associated with neurophysiological abnormalities during working memory encoding, whereas the neural processes serving maintenance seem to be preserved. The right hemispheric neural responses likely reflected compensatory processing, which patients with controlled hypertension may use to achieve verbal working memory function at the level of controls, as opposed to the uncontrolled hypertension group where diminished resources may have limited such additional recruitment.

Post-acute sequelae of SARS-CoV-2 infection (Long COVID) in older adults

Long COVID, also known as PASC (post-acute sequelae of SARS-CoV-2), is a complex infection-associated chronic condition affecting tens of millions of people worldwide. Many aspects of this condition are incompletely understood. Among them is how this condition may manifest itself in older adults and how it might impact the older population. Here, we briefly review the current understanding of PASC in the adult population and examine what is known on its features with aging. Finally, we outline the major gaps and areas for research most germane to older adults.

Novel intravital approaches to quantify deep vascular structure and perfusion in the aging mouse brain using ultrasound localization microscopy (ULM)

Intra-vital visualization of deep cerebrovascular structures and blood flow in the aging brain has been a difficult challenge in the field of neurovascular research, especially when considering the key role played by the cerebrovasculature in the pathogenesis of both vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). Traditional imaging methods face difficulties with the thicker skull of older brains, making high-resolution imaging and cerebral blood flow (CBF) assessment challenging. However, functional ultrasound (fUS) imaging, an emerging non-invasive technique, provides real-time CBF insights with notable spatial-temporal resolution. This study introduces an enhanced longitudinal fUS method for aging brains. Using elderly (24-month C57BL/6) mice, we detail replacing the skull with a polymethylpentene window for consistent fUS imaging over extended periods. Ultrasound localization mapping (ULM), involving the injection of a microbubble (<<10 μm) suspension allows for recording of high-resolution microvascular vessels and flows. ULM relies on the localization and tracking of single circulating microbubbles in the blood flow. A FIJI-based analysis interprets these high-quality ULM visuals. Testing on older mouse brains, our method successfully unveils intricate vascular specifics even in-depth, showcasing its utility for longitudinal studies that require ongoing evaluations of CBF and vascular aspects in aging-focused research.

Under pressure: the interplay of hypertension and white matter hyperintensities with cognition in chronic stroke aphasia

While converging research suggests that increased white matter hyperintensity load is associated with poorer cognition, and the presence of hypertension is associated with increased white matter hyperintensity load, the relationship among hypertension, cognition and white matter hyperintensities is not well understood. We sought to determine the effect of white matter hyperintensity burden on the relationship between hypertension and cognition in individuals with post-stroke aphasia, with the hypothesis that white matter hyperintensity load moderates the relationship between history of hypertension and cognitive function. Health history, Fazekas scores for white matter hyperintensities and Wechsler Adult Intelligence Scale Matrix Reasoning subtest scores for 79 people with aphasia collected as part of the Predicting Outcomes of Language Rehabilitation study at the Center for the Study of Aphasia Recovery at the University of South Carolina and the Medical University of South Carolina were analysed retrospectively. We found that participants with a history of hypertension had increased deep white matter hyperintensity severity (P < 0.001), but not periventricular white matter hyperintensity severity (P = 0.116). Moderation analysis revealed that deep white matter hyperintensity load moderates the relationship between high blood pressure and Wechsler Adult Intelligence Scale scores when controlling for age, education, aphasia severity and lesion volume. The interaction is significant, showing that a history of high blood pressure and severe deep white matter hyperintensities together are associated with poorer Matrix Reasoning scores. The overall model explains 41.85% of the overall variation in Matrix Reasoning score in this group of participants. These findings underscore the importance of considering cardiovascular risk factors in aphasia treatment, specifically hypertension and its relationship to brain health in post-stroke cognitive function.

Distinct effects of blood pressure parameters on Alzheimer's and vascular markers in 1,952 Asian individuals without dementia

BACKGROUND

Risk factors for cardiovascular disease, including elevated blood pressure, are known to increase risk of Alzheimer's disease. There has been increasing awareness of the relationship between long-term blood pressure (BP) patterns and their effects on the brain. We aimed to investigate the association of repeated BP measurements with Alzheimer's and vascular disease markers.

METHODS

We recruited 1,952 participants without dementia between August 2015 and February 2022. During serial clinic visits, we assessed both systolic BP (SBP) and diastolic BP (DBP), and visit-to-visit BP variability (BPV) was quantified from repeated measurements. In order to investigate the relationship of mean SBP (or DBP) with Alzheimer's and vascular markers and cognition, we performed multiple linear and logistic regression analyses after controlling for potential confounders (Model 1). Next, we investigated the relationship of with variation of SBP (or DBP) with the aforementioned variables by adding it into Model 1 (Model 2). In addition, mediation analyses were conducted to determine mediation effects of Alzheimer's and vascular makers on the relationship between BP parameters and cognitive impairment.

RESULTS

High Aβ uptake was associated with greater mean SBP (β = 1.049, 95% confidence interval 1.016-1.083). High vascular burden was positively associated with mean SBP (odds ratio = 1.293, 95% CI 1.015-1.647) and mean DBP (1.390, 1.098-1.757). High tau uptake was related to greater systolic BPV (0.094, 0.001-0.187) and diastolic BPV (0.096, 0.007-0.184). High Aβ uptake partially mediated the relationship between mean SBP and the Mini-Mental State Examination (MMSE) scores. Hippocampal atrophy mediated the relationship between diastolic BPV and MMSE scores.

CONCLUSIONS

Each BP parameter affects Alzheimer's and vascular disease markers differently, which in turn leads to cognitive impairment. Therefore, it is necessary to appropriately control specific BP parameters to prevent the development of dementia. Furthermore, a better understanding of pathways from specific BP parameters to cognitive impairments might enable us to select the managements targeting the specific BP parameters to prevent dementia effectively.

Development and Validation of a Predictive Model for Early Identification of Cognitive Impairment Risk in Community-Based Hypertensive Patients

Objective: To investigate the risk factors for the development of mild cognitive dysfunction in hypertensive patients in the community and to develop a risk prediction model. Method: The data used in this study were obtained from two sources: the China Health and Retirement Longitudinal Study (CHARLS) and the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 1121 participants from CHARLS were randomly allocated into a training set and a validation set, following a 70:30 ratio. Meanwhile, an additional 4016 participants from CLHLS were employed for external validation of the model. The patients in this study were divided into two groups: those with mild cognitive impairment and those without. General information, employment status, pension, health insurance, and presence of depressive symptoms were compared between the two groups. LASSO regression analysis was employed to identify the most predictive variables for the model, utilizing 14-fold cross-validation. The risk prediction model for cognitive impairment in hypertensive populations was developed using generalized linear models. The model's discriminatory power was evaluated through the area under the receiver operating characteristic (ROC) curve and calibration curves. Results: In the modeling group, eight variables such as gender, age, residence, education, alcohol use, depression, employment status, and health insurance were ultimately selected from an initial pool of 21 potential predictors to construct the risk prediction model. The area under the curve (AUC) values for the training, internal, and external validation sets were 0.777, 0.785, and 0.782, respectively. All exceeded the threshold of 0.7, suggesting that the model effectively predicts the incidence of mild cognitive dysfunction in community-based hypertensive patients. A risk prediction model was developed using a generalized linear model in conjunction with Lasso regression. The model's performance was evaluated using the area under the receiver operating characteristic (ROC) curve. Hosmer-Lemeshow test values yielded p = .346 and p = .626, both of which exceeded the 0.05 threshold. Calibration curves demonstrated a significant agreement between the nomogram model and observed outcomes, serving as an effective tool for evaluating the model's predictive performance. Discussion: The predictive model developed in this study serves as a promising and efficient tool for evaluating cognitive impairment in hypertensive patients, aiding community healthcare workers in identifying at-risk populations.

Exploring the role of vitamin D in cognitive function: mediation by depression with diabetes modulation in older U.S. adults, a NHANES weighted analysis

Background

The relationship between vitamin D levels, depressive symptoms, and cognitive function has yet to be definitively understood in the elderly, particularly when considering the impact of chronic diseases. This study focuses on how depression mediates the impact of 25-hydroxyvitamin D3 (25(OH)D3) on cognitive performance in older U.S. adults.

Methods

We analyzed data from 2,745 elderly individuals extracted from the NHANES 2011-2014 cycles, applying weighted processing to account for the complex multi-stage sampling design characteristic of NHANES data. Utilizing weighted data for covariate and model selection, we conducted mediation analyses on both the overall population and subgroup data. Significant mediation pathways were validated using a stratified weighted bootstrap approach. For significant subgroup pathways, we explored interactive mechanisms through interactive mediation analysis.

Results

Mediation analyses, thoroughly accounting for the impact of chronic conditions, revealed significant pathways in both the weighted overall population and the weighted diabetes subgroup. After 1,000 stratified weighted bootstrap replications, the proportion of mediation effects were 10.6% [0.040, 0.268] and 20.9% [0.075, 0.663], respectively. Interactive mediation analysis for diabetes indicated that the interaction between diabetes and depression was not significant in the direct pathway (estimates = 0.050, p = 0.113) but was significant in the mediation pathway, yielding the largest effect size compared to other covariates (estimates = 0.981, p < 0.001).

Conclusion

This study highlights the mediating role of depression in the relationship between vitamin D levels and cognitive function in the elderly, particularly emphasizing diabetes as a key moderator. Our findings suggest targeted interventions addressing both vitamin D sufficiency and depression could significantly benefit cognitive health, especially in diabetic individuals.

Linking peripheral atherosclerosis to blood-brain barrier disruption: elucidating its role as a manifestation of cerebral small vessel disease in vascular cognitive impairment

Aging plays a pivotal role in the pathogenesis of cerebral small vessel disease (CSVD), contributing to the onset and progression of vascular cognitive impairment and dementia (VCID). In older adults, CSVD often leads to significant pathological outcomes, including blood-brain barrier (BBB) disruption, which in turn triggers neuroinflammation and white matter damage. This damage is frequently observed as white matter hyperintensities (WMHs) in neuroimaging studies. There is mounting evidence that older adults with atherosclerotic vascular diseases, such as peripheral artery disease, ischemic heart disease, and carotid artery stenosis, face a heightened risk of developing CSVD and VCID. This review explores the complex relationship between peripheral atherosclerosis, the pathogenesis of CSVD, and BBB disruption. It explores the continuum of vascular aging, emphasizing the shared pathomechanisms that underlie atherosclerosis in large arteries and BBB disruption in the cerebral microcirculation, exacerbating both CSVD and VCID. By reviewing current evidence, this paper discusses the impact of endothelial dysfunction, cellular senescence, inflammation, and oxidative stress on vascular and neurovascular health. This review aims to enhance understanding of these complex interactions and advocate for integrated approaches to manage vascular health, thereby mitigating the risk and progression of CSVD and VCID.

Predicting the reversion from mild cognitive impairment to normal cognition based on magnetic resonance imaging, clinical, and neuropsychological examinations

BACKGROUND

Reversion from mild cognitive impairment (MCI) to normal cognition (NC) is not uncommon and indicates a better cognitive trajectory. This study aims to identify predictors of MCI reversion and develop a predicting model.

METHOD

A total of 391 MCI subjects (mean age = 74.3 years, female = 61 %) who had baseline data of magnetic resonance imaging, clinical, and neuropsychological measurements were followed for two years. Multivariate logistic analyses were used to identify the predictors of MCI reversion after adjusting for age and sex. A stepwise backward logistic regression model was used to construct a predictive nomogram for MCI reversion. The nomogram was validated by internal bootstrapping and in an independent cohort.

RESULT

In the training cohort, the 2-year reversion rate was 19.95 %. Predictors associated with reversion to NC were higher education level (p = 0.004), absence of APOE4 allele (p = 0.001), larger brain volume (p < 0.005), better neuropsychological measurements performance (p < 0.001), higher glomerular filtration rate (p = 0.035), and lower mean arterial pressure (p = 0.060). The nomogram incorporating five predictors (education, hippocampus volume, the Alzheimer's Disease Assessment Scale-Cognitive score, the Rey Auditory Verbal Learning Test-immediate score, and mean arterial pressure) achieved good C-indexes of 0.892 (95 % confidence interval [CI], 0.859-0.926) and 0.806 (95 % CI, 0.709-0.902) for the training and validation cohort.

LIMITATION

Observational duration is relatively short; The predicting model warrant further validation in larger samples.

CONCLUSION

This prediction model could facilitate risk stratification and early management for the MCI population.

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.

2-(4-Methylthiazol-5-yl) Ethyl Nitrate Hydrochloride Ameliorates Cognitive Impairment via Modulation of Oxidative Stress and Nuclear Factor Kappa B (NF-κB) Signaling Pathway in Chronic Cerebral Hypoperfusion-Associated Spontaneously Hypertensive Rats

Hypertension reduces the bioavailability of vascular nitric oxide (NO) and contributes to the onset of vascular dementia (VaD). A loss of NO bioavailability increases inflammation and oxidative stress. 2-(4-Methylthiazol-5-yl) ethyl nitrate hydrochloride (W1302) is a novel nitric oxide donor (NOD) which is undergoing phase I clinical trials in China for the treatment of VaD. In this study, we investigated the protective effects of W1302 in VaD rats induced by the permanent occlusion of a bilateral common carotid arteries model related to spontaneous hypertension (SHR-2VO), and we further explored the underlying mechanisms. Nimodipine was used as a positive control. Our results showed that W1302 treatment for 4 weeks (10 mg/Kg/day) exhibited stronger improvement in the spatial learning and memory deficits in SHR-2VO rats compared with nimodipine with slightly lower systolic blood pressure (SBP). Meanwhile, W1302 treatment significantly increased NO and cGMP production, restored mitochondrial membrane potential and attenuated oxidative stress as evidenced by increasing ATP production and reducing malondialdehyde (MDA) levels in the brain. Furthermore, W1302 treatment markedly inhibited the iNOS activity and decreased TNF-α expression via inhibiting the nuclear factor kappa B (NF-κB) signaling pathway. Nimodipine treatment also restored these aberrant changes, but its ATP production was weaker than that of W1302, and there was no significant effect on NO release. Taken together, W1302 exhibited beneficial effects on complications in VaD with hypertension, which is involved in suppressing oxidative damage, and the inflammatory reaction might be mediated by an increase in NO release. Therefore, W1302 has therapeutic potential for the treatment of VaD caused by chronic cerebral hypoperfusion-associated spontaneous hypertension.

Young blood-mediated cerebromicrovascular rejuvenation through heterochronic parabiosis: enhancing blood-brain barrier integrity and capillarization in the aged mouse brain

Age-related cerebromicrovascular changes, including blood-brain barrier (BBB) disruption and microvascular rarefaction, play a significant role in the development of vascular cognitive impairment (VCI) and neurodegenerative diseases. Utilizing the unique model of heterochronic parabiosis, which involves surgically joining young and old animals, we investigated the influence of systemic factors on these vascular changes. Our study employed heterochronic parabiosis to explore the effects of young and aged systemic environments on cerebromicrovascular aging in mice. We evaluated microvascular density and BBB integrity in parabiotic pairs equipped with chronic cranial windows, using intravital two-photon imaging techniques. Our results indicate that short-term exposure to young systemic factors leads to both functional and structural rejuvenation of cerebral microcirculation. Notably, we observed a marked decrease in capillary density and an increase in BBB permeability to fluorescent tracers in the cortices of aged mice undergoing isochronic parabiosis (20-month-old C57BL/6 mice [A-(A)]; 6 weeks of parabiosis), compared to young isochronic parabionts (6-month-old, [Y-(Y)]). However, aged heterochronic parabionts (A-(Y)) exposed to young blood exhibited a significant increase in cortical capillary density and restoration of BBB integrity. In contrast, young mice exposed to old blood from aged parabionts (Y-(A)) rapidly developed cerebromicrovascular aging traits, evidenced by reduced capillary density and increased BBB permeability. These findings underscore the profound impact of systemic factors in regulating cerebromicrovascular aging. The rejuvenation observed in the endothelium, following exposure to young blood, suggests the existence of anti-geronic elements that counteract microvascular aging. Conversely, pro-geronic factors in aged blood appear to accelerate cerebromicrovascular aging. Further research is needed to assess whether the rejuvenating effects of young blood factors could extend to other age-related cerebromicrovascular pathologies, such as microvascular amyloid deposition and increased microvascular fragility.

Secondary Prevention in Patients With Stroke Versus Myocardial Infarction: Analysis of 2 National Cohorts

BACKGROUND

The implementation of preventive therapies among patients with stroke remains inadequately explored, especially when compared with patients with myocardial infarction (MI), despite sharing similar vascular risk profiles. We tested the hypothesis that participants with a history of stroke have a worse cardiovascular prevention profile in comparison to participants with MI.

METHODS AND RESULTS

In cross-sectional analyses within the UK Biobank and All of Us Research Program, involving 14 760 (9193 strokes, 5567 MIs) and 7315 (2948 strokes, 4367 MIs) participants, respectively, we evaluated cardiovascular prevention profiles assessing low-density lipoprotein (<100 mg/dL), blood pressure (systolic, <140 mm Hg; and diastolic, <90 mm Hg), statin and antiplatelet use, and a cardiovascular prevention score that required meeting at least 3 of these criteria. The results revealed that, within the UK Biobank, patients with stroke had significantly lower odds of meeting all the preventive criteria compared with patients with MI: low-density lipoprotein control (odds ratio [OR], 0.73 [95% CI, 0.68-0.78]; P<0.001), blood pressure control (OR, 0.63 [95% CI, 0.59-0.68]; P<0.001), statin use (OR, 0.45 [95% CI, 0.42-0.48]; P<0.001), antiplatelet therapy use (OR, 0.30 [95% CI, 0.27-0.32]; P<0.001), and cardiovascular prevention score (OR, 0.42 [95% CI, 0.39-0.45]; P<0.001). Similar patterns were observed in the All of Us Research Program, with significant differences across all comparisons (P<0.05), and further analysis suggested that the odds of having a good cardiovascular prevention score were influenced by race and ethnicity as well as neighborhood deprivation levels (interaction P<0.05 in both cases).

CONCLUSIONS

In 2 independent national cohorts, patients with stroke showed poorer cardiovascular prevention profiles and lower adherence to guideline-directed therapies compared with patients with MI. These findings underscore the need to explore the reasons behind the underuse of secondary prevention in vulnerable stroke survivors.

Association between intensity of physical activity and cognitive function in hypertensive patients: a case-control study

Previous studies have shown that a higher intensity of physical activity (PA) is associated with a lower risk of cognitive impairment (CI), whereas hypertension is associated with higher CI. However, there are few studies on the association between PA intensity and cognitive function in hypertensive patients. This study investigated the association between PA intensity and cognitive function in hypertensive patients. A total of 2035 hypertensive patients were included in this study, including 407 hypertensive patients with CI and 1628 hypertensive patients with normal cognitive function matched 1:4 by age and sex. The International Physical Activity Questionnaire-Long Form and the Mini-mental State Examination were used to evaluate PA intensity, total metabolic equivalents, and cognitive function in patients with hypertension. Multivariate logistic regression was used to analyze the correlation between PA intensity and CI in hypertensive patients. The Spearman correlation coefficient was used to analyze the correlation between PA intensity and the total score of each component of the MMSE and the correlation between PA total metabolic equivalents and cardiac structure in hypertensive patients. After adjusting for all confounding factors, PA intensity was negatively associated with CI in hypertensive patients (OR = 0.608, 95% CI: 0.447-0.776, P < 0.001), and this association was also observed in hypertensive patients with education level of primary school and below and junior high school and above (OR = 0.732, 95% CI: 0.539-0.995, P = 0.047; OR = 0.412, 95% CI: 0.272-0.626, P < 0.001). The intensity of PA in hypertensive patients was positively correlated with orientation (r = 0.125, P < 0.001), memory (r = 0.052, P = 0.020), attention and numeracy (r = 0.151, P < 0.001), recall ability (r = 0.110, P < 0.001), and language ability (r = 0.144, P < 0.001). PA total metabolic equivalents in hypertensive patients were negatively correlated with RVEDD and LAD (r = - 0.048, P = 0.030; r = - 0.051, P = 0.020) and uncorrelated with LVEDD (r = 0.026, P = 0.233). Higher PA intensity reduced the incidence of CI in hypertensive patients. Therefore, hypertensive patients were advised to moderate their PA according to their circumstances.

Hypertension, Neurodegeneration, and Cognitive Decline

Elevated blood pressure is a well-established risk factor for age-related cognitive decline. Long linked to cognitive impairment on vascular bases, increasing evidence suggests a potential association of hypertension with the neurodegenerative pathology underlying Alzheimer disease. Hypertension is well known to disrupt the structural and functional integrity of the cerebral vasculature. However, the mechanisms by which these alterations lead to brain damage, enhance Alzheimer pathology, and promote cognitive impairment remain to be established. Furthermore, critical questions concerning whether lowering blood pressure by antihypertensive medications prevents cognitive impairment have not been answered. Recent developments in neurovascular biology, brain imaging, and epidemiology, as well as new clinical trials, have provided insights into these critical issues. In particular, clinical and basic findings on the link between neurovascular dysfunction and the pathobiology of neurodegeneration have shed new light on the overlap between vascular and Alzheimer pathology. In this review, we will examine the progress made in the relationship between hypertension and cognitive impairment and, after a critical evaluation of the evidence, attempt to identify remaining knowledge gaps and future research directions that may advance our understanding of one of the leading health challenges of our time.

A non-linear relationship between blood pressure and mild cognitive impairment in elderly individuals: A cohort study based on the Chinese longitudinal healthy longevity survey (CLHLS)

BACKGROUND

Hypertension is an established risk factor for mild cognitive impairment (MCI) in elderly individuals. Nevertheless, the impact of different levels of blood pressure on the progression of MCI remains uncertain. This study aims to investigate the non-linear relationship between blood pressure and MCI in the elderly and detect the critical blood pressure threshold, thus, improving blood pressure management for individuals at high risk of MCI.

METHODS

Data was obtained from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) cohort. We chose normal cognitive elderly individuals who entered the cohort in 2014 for a 5-year follow-up to observe the progression of MCI. Subsequently, we utilized the Cox regression model to identify risk factors for MCI and conducted a Cox-based restricted cubic spline regression (RCS) model to examine the non-linear relationship between systolic blood pressure (SBP) and diastolic blood pressure (DBP) with MCI, determining the critical blood pressure threshold for MCI progression.

RESULTS

In the elderly population, female (HR = 1.489, 95% CI: 1.017-2.180), lacking of exercise in the past (HR = 1.714, 95% CI: 1.108-2.653), preferring animal fats (HR = 2.340, 95% CI: 1.348-4.061), increased age (HR = 1.061, 95% CI: 1.038-1.084), increased SBP (HR = 1.036, 95% CI: 1.024-1.048), and increased DBP (HR = 1.056, 95% CI: 1.031-1.081) were associated with MCI progression. After adjusting factors such as gender, exercise, preferred types of fats, and age, both SBP (P non-linear < 0.001) and DBP (P non-linear < 0.001) in elderly individuals exhibited a non-linear association with MCI. The risk of MCI rose when SBP exceeded 135 mmHg and DBP was in the range of 80-88 mmHg. However, when DBP exceeded 88 mmHg, there was a declining trend in MCI progression, although the HR remained above 1. The identified critical blood pressure management threshold for MCI was 135/80 mmHg.

CONCLUSION

In this study, we discovered that risk factors affecting the progression of MCI in elderly individuals comprise gender (female), preferring to use animal fat, lack of exercise in the past, increased age, increased SBP, and increased DBP. Additionally, a non-linear relationship between blood pressure levels and MCI progression was confirmed, with the critical blood pressure management threshold for MCI onset falling within the prehypertensive range.

Atherosclerotic burden and cerebral small vessel disease: exploring the link through microvascular aging and cerebral microhemorrhages

Cerebral microhemorrhages (CMHs, also known as cerebral microbleeds) are a critical but frequently underestimated aspect of cerebral small vessel disease (CSVD), bearing substantial clinical consequences. Detectable through sensitive neuroimaging techniques, CMHs reveal an extensive pathological landscape. They are prevalent in the aging population, with multiple CMHs often being observed in a given individual. CMHs are closely associated with accelerated cognitive decline and are increasingly recognized as key contributors to the pathogenesis of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). This review paper delves into the hypothesis that atherosclerosis, a prevalent age-related large vessel disease, extends its pathological influence into the cerebral microcirculation, thereby contributing to the development and progression of CSVD, with a specific focus on CMHs. We explore the concept of vascular aging as a continuum, bridging macrovascular pathologies like atherosclerosis with microvascular abnormalities characteristic of CSVD. We posit that the same risk factors precipitating accelerated aging in large vessels (i.e., atherogenesis), primarily through oxidative stress and inflammatory pathways, similarly instigate accelerated microvascular aging. Accelerated microvascular aging leads to increased microvascular fragility, which in turn predisposes to the formation of CMHs. The presence of hypertension and amyloid pathology further intensifies this process. We comprehensively overview the current body of evidence supporting this interconnected vascular hypothesis. Our review includes an examination of epidemiological data, which provides insights into the prevalence and impact of CMHs in the context of atherosclerosis and CSVD. Furthermore, we explore the shared mechanisms between large vessel aging, atherogenesis, microvascular aging, and CSVD, particularly focusing on how these intertwined processes contribute to the genesis of CMHs. By highlighting the role of vascular aging in the pathophysiology of CMHs, this review seeks to enhance the understanding of CSVD and its links to systemic vascular disorders. Our aim is to provide insights that could inform future therapeutic approaches and research directions in the realm of neurovascular health.

Mechanistic insights and emerging therapeutic stratagems for Alzheimer's disease

Alzheimer's disease (AD), a multi-factorial neurodegenerative disorder has affected over 30 million individuals globally and these numbers are expected to increase in the coming decades. Current therapeutic interventions are largely ineffective as they focus on a single target. Development of an effective drug therapy requires a deep understanding of the various factors influencing the onset and progression of the disease. Aging and genetic factors exert a major influence on the development of AD. Other factors like post-viral infections, iron overload, gut dysbiosis, and vascular dysfunction also exacerbate the onset and progression of AD. Further, post-translational modifications in tau, DRP1, CREB, and p65 proteins increase the disease severity through triggering mitochondrial dysfunction, synaptic loss, and differential interaction of amyloid beta with different receptors leading to impaired intracellular signalling. With advancements in neuroscience tools, new inter-relations that aggravate AD are being discovered including pre-existing diseases and exposure to other pathogens. Simultaneously, new therapeutic strategies involving modulation of gene expression through targeted delivery or modulation with light, harnessing the immune response to promote clearance of amyloid deposits, introduction of stem cells and extracellular vesicles to replace the destroyed neurons, exploring new therapeutic molecules from plant, marine and biological sources delivered in the free state or through nanoparticles and use of non-pharmacological interventions like music, transcranial stimulation and yoga. Polypharmacology approaches involving combination of therapeutic agents are also under active investigation for superior therapeutic outcomes. This review elaborates on various disease-causing factors, their underlying mechanisms, the inter-play between different disease-causing players, and emerging therapeutic options including those under clinical trials, for treatment of AD. The challenges involved in AD therapy and the way forward have also been discussed.

Effect of the duration of hypertension on white matter structure and its link with cognition

The relation between hypertension (HTN) and cognition has been reported inclusive results, which may be affected by disease duration. Our study aimed to examine the influence of HTN duration on cognition and its underlying white matter (WM) changes including macrostructural WM hyperintensities (WMH) and microstructural WM integrity. A total of 1218 patients aged ≥55 years with neuropsychological assessment and a subgroup of 233 people with imaging data were recruited and divided into 3 groups (short duration: <5 years, medium duration: 5-20 years, long duration: >20 years). We found that greater HTN duration was preferentially related to worse executive function (EF), processing speed (PS), and more severe WMH, which became more significant during long duration stage. The reductions in WM integrity were evident at the early stage especially in long-range association fibers and then scattered through the whole brain. Increasing WMH and decreasing integrity of specific tracts consistently undermined EF. Furthermore, free water imaging method greatly enhanced the sensitivity in detecting HTN-related WM alterations. These findings supported that the neurological damaging effects of HTN is cumulative and neuroimaging markers of WM at macro- and microstructural level underlie the progressive effect of HTN on cognition.

The protective effects of Irbesartan in cognitive impairment in hypertension

Vascular cognitive impairment (VCI) is claimed as the second most common type of dementia after Alzheimer's disease (AD), in which hypertension is a critical inducer. Currently, hypertension-induced cognitive impairment lacks clinical treatments. Irbesartan is a long-acting angiotensin receptor antagonist with promising antihypertensive properties. Our research will focus on the potential function of Irbesartan on hypertension-induced cognitive impairment. Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats were orally dosed with normal saline or 20 mg/kg/day Irbesartan for 14 consecutive days, with 4 groups divided shown as below: WKY, Irbesartan, SHR, SHR+ Irbesartan. Firstly, the markedly increased systolic blood pressure observed in SHR rats was signally repressed by Irbesartan on Day 7 and 14 post-dosing. Moreover, notably decreased time of exploring the novel object in the object recognition task (ORT) test, elevated escape latency, and reduced time in the target quadrant in the Morris water maze (MWM) test were observed in SHR rats, which were prominently reversed by Irbesartan. Furthermore, the declined superoxide dismutase (SOD) activity, elevated malondialdehyde (MDA) level, increased cyclin-dependent kinase-5 (CDK5) activity, and enhanced protein level of p35/p25, p-Tau (pSer214)/Tau46, and brain-derived neurotrophic factor (BDNF) were memorably rescued by Irbesartan. Lastly, the activity of cAMP/cAMP response element binding protein (CREB) signaling in the hippocampus of SHR rats was markedly repressed, accompanied by an upregulation of phosphodiesterase 4B (PDE4B), which was observably rescued by Irbesartan. Collectively, Irbesartan protected against the hypertension-induced cognitive impairment in SHR rats by regulating the cAMP/CREB signaling.

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.

Risk factors for intracerebral hemorrhage in small-vessel disease and non-small-vessel disease etiologies-an observational proof-of-concept study

Background

Sporadic cerebral small-vessel disease (CSVD), i.e., hypertensive arteriopathy (HA) and cerebral amyloid angiopathy (CAA), is the main cause of spontaneous intracerebral hemorrhage (ICH). Nevertheless, a substantial portion of ICH cases arises from non-CSVD etiologies, such as trauma, vascular malformations, and brain tumors. While studies compared HA- and CAA-related ICH, non-CSVD etiologies were excluded from these comparisons and are consequently underexamined with regard to additional factors contributing to increased bleeding risk beyond their main pathology.

Methods

As a proof of concept, we conducted a retrospective observational study in 922 patients to compare HA, CAA, and non-CSVD-related ICH with regard to factors that are known to contribute to spontaneous ICH onset. Medical records (available for n = 861) were screened for demographics, antithrombotic medication, and vascular risk profile, and CSVD pathology was rated on magnetic resonance imaging (MRI) in a subgroup of 185 patients. The severity of CSVD was assessed with a sum score ranging from 0 to 6, where a score of ≥2 was defined as advanced pathology.

Results

In 922 patients with ICH (median age of 71 years), HA and CAA caused the majority of cases (n = 670, 73%); non-CSVD etiologies made up the remaining quarter (n = 252, 27%). Individuals with HA- and CAA-related ICH exhibited a higher prevalence of predisposing factors than those with non-CSVD etiologies. This includes advanced age (median age: 71 vs. 75 vs. 63 years, p < 0.001), antithrombotic medication usage (33 vs. 37 vs. 19%, p < 0.001), prevalence of vascular risk factors (70 vs. 67 vs. 50%, p < 0.001), and advanced CSVD pathology on MRI (80 vs. 89 vs. 51%, p > 0.001). However, in particular, half of non-CSVD ICH patients were either aged over 60 years, presented with vascular risk factors, or had advanced CSVD on MRI.

Conclusion

Risk factors for spontaneous ICH are less common in non-CSVD ICH etiologies than in HA- and CAA-related ICH, but are still frequent. Future studies should incorporate these factors, in addition to the main pathology, to stratify an individual's risk of bleeding.

Association between socio-demographic factors, lifestyle, eating habits and hypertension risk among middle-aged and older rural Chinese adults

BACKGROUND AND AIMS

Hypertension is a global health issue with increasing prevalence. This study aimed to understand the epidemiological characteristics and influencing factors of hypertension in rural Chinese populations and help develop effective prevention and control strategies.

METHODS AND RESULTS

This cross-sectional study used database from the Early Diagnosis and Early Treatment Project of Esophageal Cancer conducted in a rural population from September 2012 to December 2017. A total of 10,111 subjects aged 35-75 years residing in Huai'an District, Huai'an City, Jiangsu Province for at least three years were included. Unconditional univariate and multivariate logistic regression models were performed to evaluate the association between socio-demographic information, lifestyle habits, dietary characteristics and the risk of hypertension. The prevalence of hypertension was 34.32 % in this rural population. Men and older individuals are more likely to have hypertension when compared with women and young individuals, respectively. Factors associated with an increased risk of hypertension included: fast eating speed, a high-salt diet (both currently and ten years ago), a high-spicy diet ten years ago, high BMI, poor educational attainment, preference for fatty meats, hot diet, green tea drinking, intake of pickled potherb mustard and corn flour, family smoking and alcohol consumption. Light smoking in males, consumption of fruits, adzuki bean, and pork liver were associated with reduced risk of hypertension.

CONCLUSIONS

The study identified some factors, including eat habits and lifestyle, associated with hypertension risk, and highlighted the need for targeted policies and interventions in rural China to address potential risk factors for hypertension.

Digital computerised cognitive training for preventing cognitive decline among hypertensive patients: a study protocol for a multicentre randomised controlled trial (DELIGHT trial)

INTRODUCTION

Mild cognitive impairment (MCI) is an important intervenable stage for the prevention of dementia. Hypertension is associated with impaired cognition, and when combined with MCI, it may lead to a poor prognosis. Digital computerised cognitive training (CCT) has recently become a potential instrument for improving cognition, but evidence for its efficacy remains limited. This study aims to evaluate the efficacy of a digital adaptive CCT intervention in older patients with hypertension and MCI.

METHODS AND ANALYSIS

The multicentre, double-blinded, randomised, actively -controlled clinical trial will recruit 200 older (≥60 years) patients with hypertension and MCI from 11 hospitals across China. Participants will be randomly assigned in a 1:1 ratio to the intervention group (multidomain adaptative CCT) and active control group (non-adaptive cognitive training) for 12-week cognitive training for 30 min/day and 5 days/week. Those who have completed their 12-week training in the intervention group will be rerandomised into the continuation and discontinuation training groups. All participants will be followed up to 24 weeks. Neuropsychological assessments and structural and functional 7.0 T MRI will be obtained at baseline and at 12-week and 24-week follow-up. The primary outcome is the possible improvement of global cognitive function at 12 weeks, as measured by the Basic Cognitive Aptitude Tests. Secondary and exploratory endpoints include the major cognitive domain function improvement, self-efficacy, mental health, quality of life and MRI measurements of the brain.

ETHICS AND DISSEMINATION

The trial has been approved by the institutional review board of Beijing Anzhen Hospital and thereafter by all other participating centres. Trial findings will be disseminated in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05704270.

Investigating the effect of hypertension on vascular cognitive impairment by using the resting-state functional connectome

Hypertension (HTN) affects over 1.2 billion individuals worldwide and is defined as systolic blood pressure (BP) ≥ 140 mmHg and diastolic BP ≥ 90 mmHg. Hypertension is also considered a high risk factor for cerebrovascular diseases, which may lead to vascular cognitive impairment (VCI). VCI is associated with executive dysfunction and is also a transitional stage between hypertension and vascular dementia. Hence, it is essential to establish a reliable approach to diagnosing the severity of VCI. In 28 HTN (51-83 yrs; 18 males, 10 females) and 28 healthy controls (HC) (51-75 yrs; 7 males, 21 females), we investigated which regions demonstrate alterations in the resting-state functional connectome due to vascular cognitive impairment in HTN by using the amplitude of the low-frequency fluctuations (ALFF), regional homogeneity (ReHo), graph theoretical analysis (GTA), and network-based statistic (NBS) methods. In the group comparison between ALFF/ReHo, HTN showed reduced spontaneous activity in the regions corresponding to vascular or metabolic dysfunction and enhanced brain activity, mainly in the primary somatosensory cortex and prefrontal areas. We also observed cognitive dysfunction in HTN, such as executive function, processing speed, and memory. Both the GTA and NBS analyses indicated that the HTN demonstrated complex local segregation, worse global integration, and weak functional connectivity. Our findings show that resting-state functional connectivity was altered, particularly in the frontal and parietal regions, by hypertensive individuals with potential vascular cognitive impairment.

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

Background

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

Objectives

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

Methods

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

Results

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

Conclusion

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

Systematic review registration

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

Microvascular rarefaction caused by the NOTCH signaling pathway is a key cause of TKI-apatinib-induced hypertension and cardiac damage

With the advancement of tumour-targeted therapy technology, the survival of cancer patients has continued to increase, and cardiovascular events have gradually become an important cause of death in cancer patients. This phenomenon occurs due to adverse cardiovascular reactions caused by the cardiovascular toxicity of antitumour therapy. Moreover, the increase in the proportion of elderly patients with cancer and cardiovascular diseases is due to the extension of life expectancy. Hypertension is the most common cardiovascular side effect of small molecule tyrosine kinase inhibitors (TKIs). The increase in blood pressure induced by TKIs and subsequent cardiovascular complications and events affect the survival and quality of life of patients and partly offset the benefits of antitumour therapy. Many studies have confirmed that in the pathogenesis of hypertension, arterioles and capillary thinness are involved in its occurrence and development. Our previous findings showing that apatinib causes microcirculation rarefaction of the superior mesenteric artery and impaired microvascular growth may inspire new therapeutic strategies for treating hypertension. Thus, by restoring microvascular development and branching patterns, total peripheral resistance and blood pressure are reduced. Therefore, exploring the key molecular targets of TKIs that inhibit the expression of angiogenic factors and elucidating the specific molecular mechanism involved are key scientific avenues for effectively promoting endothelial cell angiogenesis and achieving accurate repair of microcirculation injury in hypertension patients.

Systolic blood pressure is associated with abnormal alterations in brain cortical structure: Evidence from a Mendelian randomization study

BACKGROUND

Hypertension has been recognized as a significant risk factor for cerebrovascular diseases and cognitive decline. However, the specific impact of hypertension, systolic/diastolic blood pressure, pulse pressure (PP) and mean arterial pressure (MAP) on brain cortical structure remains unclear. Mendelian randomization (MR) provides a robust approach to investigate the causal relationship between blood pressure components and brain cortical changes.

METHODS

In this MR study, data from large-scale genome-wide association studies for blood pressure components and neuroimaging were utilized to conduct our analyses. We leveraged genetic variants associated specifically with hypertension (122,620 cases and 332,683 controls), systolic (469,767 individuals), diastolic (490,469 individuals) blood pressure, PP (810,865 individuals) and MAP (over 1 million individuals) to evaluate their effects on brain cortex surficial area (51,665 individuals) and cortex thickness (51,665 individuals).

RESULTS

Our findings revealed a significant correlation between systolic blood pressure and abnormal reduction in brain cortex surficial area (β=-1330.69, 95% confident interval [CI]: -2655.35 to -6.02, p = 0.0489); however, no significant relationship was found between systolic blood pressure and brain cortex thickness (β=-0.0078, 95% CI: -0.0178 to 0.0022, p = 0.1287). Additionally, no significant associations were observed between hypertension (β=-200.05, p = 0.6884; β=-0.0051, p = 0.1179, respectively), diastolic blood pressure (β=-460.63, p = 0.5160; β=0.0047, p = 0.2448, respectively), PP (β=1041.84, p = 0.3725; β=-0.0112, p = 0.2212, respectively), MAP (β=-18.84, p = 0.8841; β=0.0002, p = 0.7654, respectively) and both brain cortex surficial area and brain cortex thickness.

CONCLUSION

Our MR study provides evidence supporting the hypothesis that systolic blood pressure, rather than diastolic blood pressure, PP or MAP, is associated with abnormal changes in brain cortical structure.

Time in target range of systolic blood pressure and cognitive outcomes in patients with hypertension

BACKGROUND

Blood pressure (BP) is a dynamic measure that fluctuates over time. However, conventional BP control indicators may not adequately reflect the variability of BP during a period of time.

METHODS

We performed a secondary analysis of the Systolic Blood Pressure Intervention Trial (SPRINT), which compared systolic blood pressure (SBP) targets of <120 mmHg (intensive) and <140 mmHg (standard) among patients with hypertension and high cardiac risks. The target ranges were defined as 110 to 130 mmHg in intensive treatment arm and 120 to 140 mmHg in standard treatment arm, respectively. Time in target range (TTR) was calculated based on SBP measurements recorded during the first 3-month follow-up using linear interpolation method. The Fine-Gray competing risk regression models were used to evaluate the association between TTR and cognitive outcomes.

RESULTS

A total of 7965 patients with the mean (SD) age of 68.0 (9.2) years were included, and 35% were female. Patients with higher TTR were younger, more likely to be male and take <3 BP-lowering agents. Compared to the last quartile, the first quartile of TTR was significantly associated with a higher risk of probable dementia (HR: 1.74; 95% CI: 1.22-2.46; p = 0.002) and the composite of probable dementia or mild cognitive impairment (HR: 1.26; 95% CI: 1.03-1.55; p = 0.025). The risk of probable dementia and the composite outcome increased with per quartile decrease of TTR (HR: 1.18; 95% CI: 1.06-1.30; p = 0.002 and HR: 1.07; 95% CI: 1.00-1.14; p = 0.036). Sensitivity analyses showed similar results after adjusting mean SBP during the first 3-month follow-up.

CONCLUSIONS

In this secondary analysis of SPRINT data, TTR was independently associated with probable dementia among patients with hypertension, suggesting that TTR could be used as a practical metric of BP control to evaluate the risk of dementia in older adults.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Identifier: NCT01206062.

Sex Differences in the Association of Age at Hypertension Diagnosis With Brain Structure

BACKGROUND

Sex differences exist in the likelihood of cognitive decline. The age at hypertension diagnosis is a unique contributor to brain structural changes associated with cerebral small vessel disease. However, whether this relationship differs between sexes remains unclear. Therefore, our objective was to evaluate sex differences in the association between the age at hypertension diagnosis and cerebral small vessel disease-related brain structural changes.

METHODS

We used data from the UK Biobank to select participants with a known age at hypertension diagnosis and brain magnetic resonance imaging (n=9430) and stratified them by sex and age at hypertension diagnosis. Control participants with magnetic resonance imaging scans but no hypertension were chosen at random matched by using propensity score matching. For morphological brain structural changes, generalized linear models were used while adjusting for other vascular risk factors. For the assessment of white matter microstructure, principal component analysis led to a reduction in the number of fractional anisotropy variables, followed by regression analysis with major principal components as outcomes.

RESULTS

Males but not females with a younger age at hypertension diagnosis exhibited lower brain gray and white matter volume compared with normotensive controls. The volume of white matter hyperintensities was greater in both males and females with hypertension than normotensive controls, significantly higher in older females with hypertension. Compared with normotensive controls, white matter microstructural integrity was lower in individuals with hypertension, which became more prominent with increasing age.

CONCLUSIONS

Our study demonstrates that the effect of hypertension on cerebral small vessel disease-related brain structure differs by sex and by age at hypertension diagnosis.

Severer air pollution, poorer cognitive function: Findings from 176,345 elders in Northwestern China

BACKGROUND

Limited evidence exists regarding the link between air pollution exposure and cognitive function in developing countries, particularly in areas with abundant natural sources of particulate matter.

OBJECTIVES

To investigate this association in a large representative sample of the elderly in northwestern China.

METHODS

We performed a cross-sectional study among 176,345 participants aged 60-100 years in northwestern China in 2020. A satellite-based spatiotemporal model was applied to assess three-year annual averages of particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM2.5), ≤ 10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) at residential address. Poor cognitive function was assessed using the Mini-Mental State Examination (MMSE). Generalized linear mixed models were used to assess associations.

RESULTS

Compared with participants with the lowest quartiles of PM2.5, PM10, and O3 levels, those with the second, third, and highest quartiles of air pollutants consistently showed increased odds of poor cognitive function and decreased MMSE scores. The odds ratios of poor cognitive function associated with a 10 μg/m3 increment in PM2.5, PM10, and O3 were 1.26 (95 % confidence interval [CI]: 1.17, 1.36), 1.06 (95 %CI: 1.04, 1.08), and 2.76 (95 %CI: 2.11, 3.62), respectively. Subgroup analyses suggested stronger associations between air pollution exposures and poor cognitive function among participants who were younger, were non-Uyghur and were physically active.

CONCLUSION

Long-term exposures to PM2.5, PM10 and O3 were associated with poor cognitive function in elders. Our results suggest that reducing air pollution may alleviate the burden of poor cognitive function in the elderly.

From Liver to Brain: How MAFLD/MASLD Impacts Cognitive Function

Metabolic dysfunction-associated fatty liver disease or metabolic dysfunction-associated steatotic liver disease (MAFLD/MASLD), is a common chronic liver condition affecting a substantial global population. Beyond its primary impact on liver function, MAFLD/MASLD is associated with a myriad of extrahepatic manifestations, including cognitive impairment. The scope of cognitive impairment within the realm of MAFLD/MASLD is a matter of escalating concern. Positioned as an intermediate stage between the normal aging process and the onset of dementia, cognitive impairment manifests as a substantial challenge associated with this liver condition. Insights from studies underscore the presence of compromised executive function and a global decline in cognitive capabilities among individuals identified as being at risk of progressing to liver fibrosis. Importantly, this cognitive impairment transcends mere association with metabolic factors, delving deep into the intricate pathophysiology characterizing MAFLD/MASLD. The multifaceted nature of cognitive impairment in the context of MAFLD/MASLD is underlined by a spectrum of factors, prominently featuring insulin resistance, lipotoxicity, and systemic inflammation as pivotal contributors. These factors interplay within the intricate landscape of MAFLD/MASLD, fostering a nuanced understanding of the links between hepatic health and cognitive function. By synthesizing the available evidence, exploring potential mechanisms, and assessing clinical implications, the overarching aim of this review is to contribute to a more complete understanding of the impact of MAFLD/MASLD on cognitive function.

Associations of Intracranial Artery Length and Branch Number on Time-of-Flight MRA With Cognitive Impairment in Hypertensive Older Males

BACKGROUND

Hypertension-induced impairment of the cerebral artery network contributes to cognitive impairment. Characterizing the structure and function of cerebral arteries may facilitate the understanding of hypertension-related pathological mechanisms and lead to the development of new indicators for cognitive impairment.

PURPOSE

To investigate the associations between morphological features of the intracranial arteries distal to the circle of Willis on time-of-flight MRA (TOF-MRA) and cognitive performance in a hypertensive cohort.

STUDY TYPE

Prospective observational study.

POPULATION

189 hypertensive older males (mean age 64.9 ± 7.2 years).

FIELD STRENGTH/SEQUENCE

TOF-MRA sequence with a 3D spoiled gradient echo readout and arterial spin labeling perfusion imaging sequence with a 3D stack-of-spirals fast spin echo readout at 3T.

ASSESSMENT

The intracranial arteries were segmented from TOF-MRA and the total length of distal arteries (TLoDA) and number of arterial branches (NoB) were calculated. The mean gray matter cerebral blood flow (GM-CBF) was extracted from arterial spin labeling perfusion imaging. The cognitive level was assessed with short-term and long-term delay-recall auditory verbal learning test (AVLT) scores, and with montreal cognitive assessment.

STATISTICAL TESTS

Univariable and multivariable linear regression were used to analyze the associations between TLoDA, NoB, GM-CBF and the cognitive assessment scores, with P < 0.05 indicating significance.

RESULTS

TLoDA (r = 0.314) and NoB (r = 0.346) were significantly correlated with GM-CBF. Multivariable linear regression analyses showed that TLoDA and NoB, but not GM-CBF (P = 0.272 and 0.141), were significantly associated with short-term and long-term delay-recall AVLT scores. These associations remained significant after adjusting for GM-CBF.

DATA CONCLUSION

The TLoDA and NoB of distal intracranial arteries on TOF-MRA are significantly associated with cognitive impairment in hypertensive subjects.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 3.

Blood pressure variability supersedes heart rate variability as a real-world measure of dementia risk

Blood pressure variability (BPV) and heart rate variability (HRV) have been associated with Alzheimer's Disease and Related Dementias (ADRD) in rigorously controlled studies. However, the extent to which BPV and HRV may offer predictive information in real-world, routine clinical care is unclear. In a retrospective cohort study of 48,204 adults (age 54.9 ± 17.5 years, 60% female) receiving continuous care at a single center, we derived BPV and HRV from routinely collected clinical data. We use multivariable Cox models to evaluate the association of BPV and HRV, separately and in combination, with incident ADRD. Over a median 3 [2.4, 3.0] years, there were 443 cases of new-onset ADRD. We found that clinically derived measures of BPV, but not HRV, were consistently associated with incident ADRD. In combined analyses, only patients in both the highest quartile of BPV and lowest quartile of HRV had increased ADRD risk (HR 2.34, 95% CI 1.44-3.81). These results indicate that clinically derived BPV, rather than HRV, offers a consistent and readily available metric for ADRD risk assessment in a real-world patient care setting. Thus, implementation of BPV as a widely accessible tool could allow clinical providers to efficiently identify patients most likely to benefit from comprehensive ADRD screening.

Sex and gender correlates of sexually polymorphic cognition

BACKGROUND

Sexually polymorphic cognition (SPC) results from the interaction between biological (birth-assigned sex (BAS), sex hormones) and socio-cultural (gender identity, gender roles, sexual orientation) factors. The literature remains quite mixed regarding the magnitude of the effects of these variables. This project used a battery of classic cognitive tests designed to assess the influence of sex hormones on cognitive performance. At the same time, we aimed to assess the inter-related and respective effects that BAS, sex hormones, and gender-related factors have on SPC.

METHODS

We recruited 222 adults who completed eight cognitive tasks that assessed a variety of cognitive domains during a 150-min session. Subgroups were separated based on gender identity and sexual orientation and recruited as follows: cisgender heterosexual men (n = 46), cisgender non-heterosexual men (n = 36), cisgender heterosexual women (n = 36), cisgender non-heterosexual women (n = 38), gender diverse (n = 66). Saliva samples were collected before, during, and after the test to assess testosterone, estradiol, progesterone, cortisol, and dehydroepiandrosterone. Psychosocial variables were derived from self-report questionnaires.

RESULTS

Cognitive performance reflects sex and gender differences that are partially consistent with the literature. Interestingly, biological factors seem to better explain differences in male-typed cognitive tasks (i.e., spatial), while psychosocial factors seem to better explain differences in female-typed cognitive tasks (i.e., verbal).

CONCLUSION

Our results establish a better comprehension of SPC over and above the effects of BAS as a binary variable. We highlight the importance of treating sex as a biological factor and gender as a socio-cultural factor together since they collectively influence SPC.

Methylglyoxal accumulation contributes to accelerated brain aging in spontaneously hypertensive rats

While it is well-acknowledged that neurovascular dysfunction in hypertension is tightly associated with accelerated brain aging, we contend that the deleterious effects of hypertension may extend beyond affecting only the arteries. Methylglyoxal (MG) derived from glycolysis, is involved in the accumulation of advanced glycated end products (AGEs), which are the hallmarks of neurodegenerative disorders. Therefore, the present study aims to firstly investigate the role of MG metabolism in the hypertension-accelerated brain aging process. The results of our study indicate that the levels of MG increase with age in both the plasma and hippocampus of SHRs at 12, 16, and 30 weeks old. AGE methylglyoxal-hydro imidazoline-1 (MG-H1) is primarily localized in astrocytes, while its presence was not observed in neurons and microglia within the hypertensive hippocampus. Our observations also suggest that angiotensin II (Ang II) enhances glucose uptake and glycolysis while reducing the expression of Glo1 in cultured astrocytes. N-acetylcysteine (NAC) was found to counteract the increase in escape latency and inhibit the activation of the AGEs-RAGE axis in 30-week-old SHRs. NAC decreased Iba-1 immunofluorescence intensity, inhibited the levels of pro-inflammatory markers, and enhanced the abundance of anti-inflammatory markers in the hippocampus of SHRs. Moreover, NAC reduced the immunofluorescence signal of 4HNE and increased the content of GSH and SOD in SHRs. Finally, NAC was observed to inhibit apoptosis in the hippocampus of SHRs. Collectively, we firstly showed the enhanced accumulation of MG in the hypertensive brain, whereas the clearance of MG by NAC treatment mitigated the aging process and attenuated AGEs generation, neuroinflammation, and oxidative damage.

CAIDE Score, Alzheimer's Disease Pathology, and Cognition in Cognitively Normal Adults: The CABLE Study

Background

Cardiovascular Risk Factors, Ageing and Dementia (CAIDE) risk score serves as a credible predictor of an individual's risk of dementia. However, studies on the link of the CAIDE score to Alzheimer's disease (AD) pathology are scarce.

Objective

To explore the links of CAIDE score to cerebrospinal fluid (CSF) biomarkers of AD as well as to cognitive performance.

Methods

In the Chinese Alzheimer's Biomarker and LifestylE (CABLE) study, we recruited 600 cognitively normal participants. Correlations between the CAIDE score and CSF biomarkers of AD as well as cognitive performance were probed through multiple linear regression models. Whether the correlation between CAIDE score and cognitive performance was mediated by AD pathology was researched by means of mediation analyses.

Results

Linear regression analyses illustrated that CAIDE score was positively associated with tau-related biomarkers, including pTau (p < 0.001), tTau (p < 0.001), as well as tTau/Aβ42 (p = 0.008), while it was in negative association with cognitive scores, consisting of MMSE score (p < 0.001) as well as MoCA score (p < 0.001). The correlation from CAIDE score to cognitive scores was in part mediated by tau pathology, with a mediation rate varying from 3.2% to 13.2%.

Conclusions

A higher CAIDE score, as demonstrated in our study, was linked to more severe tau pathology and poorer cognitive performance, and tau pathology mediated the link of CAIDE score to cognitive performance. Increased dementia risk will lead to cognitive decline through aggravating neurodegeneration.

Effects of physical activity and depressive symptoms on cognitive function in older adults: National Health and Nutrition Examination Survey

BACKGROUND & AIMS

Population aging is a growing phenomenon, with cognitive impairment becoming a prevalent issue among the elderly. This study aimed to investigate the impact of physical activity and depressive symptoms on cognitive function in older adults using a nationally representative data set of U.S. older adults aged ≥ 60 years.

METHODS

The study comprised 2713 participants aged ≥ 60 from the National Health and Nutrition Examination Survey 2011-2014. Participants were classified into two groups: Cognitive impairment and No-Cognitive impairment, determined by the results of the Digit Symbol Substitution Test (DSST). Physical activity (PA) was assessed using the Global Physical Activity questionnaire (GPAQ), while depressive symptoms were evaluated using the Patient Health Questionnaire (PHQ-9). Logistic regression analysis examined the relationship between physical activity, depressive symptoms and cognitive function.

RESULTS

Multifactorial logistic regression analysis showed that high levels of physical activity were found to be significantly associated with a lower risk of cognitive impairment compared to low levels of physical activity [OR = 0.789, 95% CI:0.632 ~ 0.986, P = 0.037]. On the other hand, the presence of major depressive symptoms was significantly associated with a higher risk of cognitive impairment compared to the absence of depressive symptoms [OR = 3.482, 95% CI: 2.278 ~ 5.324, P < 0.001]. Participants in the recreational physical activity group exhibited higher Cognitive scores (P < 0.001), indicating better cognitive functioning.

CONCLUSION

High levels of Physical activity were independently associated with a lower incident cognitive impairment. Additionally, the severity of depression was positively correlated with an increased risk of cognitive impairment.

Angiotensin Receptor Blockers and Cognition: a Scoping Review

PURPOSE OF REVIEW

To provide an overview of the association between angiotensin II receptor blocker (ARB) use and cognitive outcomes.

RECENT FINDINGS

ARBs have previously shown greater neuroprotection compared to other anti-hypertensive classes. The benefits are primarily attributed to the ARB's effect on modulating the renin-angiotensin system via inhibiting the Ang II/AT1R pathway and activating the Ang II/AT2R, Ang IV/AT4R, and Ang-(1-7)/MasR pathways. These interactions are associated with pleiotropic neurocognitive benefits, including reduced β-amyloid accumulation and abnormal hyperphosphorylation of tau, ameliorated brain hypo-fusion, reduced neuroinflammation and synaptic dysfunction, better neurotoxin clearing, and blood-brain barrier function restoration. While ACEis also inhibit AT1R, they simultaneously lower Ang II and block the Ang II/AT2R and Ang IV/AT4R pathways that counterbalance the potential benefits. ARBs may be considered an adjunctive approach for neuroprotection. This preliminary evidence, coupled with their underlying mechanistic pathways, emphasizes the need for future long-term randomized trials to yield more definitive results.

Hypertension, Cognitive Decline, and Mild Cognitive Impairment Among Diverse Hispanics/Latinos: Study of Latinos-Investigation of Neurocognitive Aging Results (SOL-INCA)

BACKGROUND

Hypertension can have deleterious effects on cognitive function; however, few studies have examined its effects on cognition among Hispanics/Latinos.

OBJECTIVE

To assess associations between hypertension status with 1) change in cognitive performance, and 2) having mild cognitive impairment (MCI) among diverse Hispanics/Latinos.

METHODS

This population-based, prospective cohort, multisite study included Hispanic/Latino adults aged 45 to 72 years in enrolled in the Hispanic Community Health Study/Study of Latinos at Visit 1 (2008-2011; mean age of 63.40±8.24 years), and the Study of Latinos-Investigation of Neurocognitive Aging at Visit 2 (2016-2018), with a mean follow-up duration of 7 years (n = 6,173). Hypertension status was assessed at both visits: normotension (no hypertension), incident hypertension (only at Visit 2), and persistent hypertension (at both visits). We examined change in cognitive performance and having MCI (only assessed at Visit 2) relative to hypertension status and adjusted for demographics and cardiovascular disease risk factors.

RESULTS

Compared to normotension, persistent hypertension was associated with significantly increased decline in verbal fluency (β= -0.08; CI = [-0.16;-0.01]; p < 0.05), and processing speed (β= -0.11; CI = [-0.20;-0.02]; p < 0.05). Incident hypertension was not associated with significant change in cognitive performance. Both incident (OR = 1.70; CI = [1.16;2.50]; p < 0.01) and persistent hypertension (OR = 2.13; CI = [1.57;2.88]; p < 0.001) were associated with significantly higher odds ratios of having MCI.

CONCLUSIONS

These findings indicate that persistent hypertension is associated with clinical impairment and domain-specific cognitive decline in middle-aged and older Hispanics/Latinos. It underscores the importance of monitoring blood pressure in routine healthcare visits beginning at midlife in this population to reduce the burden of cognitive decline.

Analysis of the correlations between the extracranial internal carotid artery and extracranial vertebral artery and mild cognitive impairment

BACKGROUND

Vascular tortuosity is a prevalent morphological change that frequently occurs in arteries across different parts of the body.

OBJECTIVE

To analyze the relationship between the tortuosities of the extracranial internal carotid artery (EICA) and extracranial vertebral artery (EVA) with mild cognitive impairment.

METHODS

The tortuosity index (TI), vascular deviation degree, tortuosity degree, and angle number of the EICA and EVA were retrospectively analyzed and calculated in 160 patients who underwent computed tomography angiography (CTA) in this study's department, and the Montreal cognitive assessment was adopted to evaluate the cognitive function of the patients.

RESULTS

The differences in age, gender, arterial hypertension (AH), and diabetes mellitus (DM) between the normal group and the mild cognitive impairment group were statistically significant (p< 0.01). The TI was negatively correlated with the score of cognitive function. The tortuosities of the EICA and EVA were correlated with mild cognitive impairment (p< 0.05). The reduction in visual-spatial ability was correlated with the right EICA tortuosity, and the reduction in memory was correlated with the EVA tortuosity. Age, gender, HP, DM, and coronary heart disease (CHD) were potential risk factors for carotid tortuosity (p< 0.05).

CONCLUSION

There was a significant correlation observed between the TIs of both the EICA and EVA and the presence of mild cognitive impairment. Advanced age, female, HP, DM, and CHD were independent risk factors for EICA and EVA tortuosities.

Basic Mechanisms of Brain Injury and Cognitive Decline in Hypertension

Dementia affects almost 50 million adults worldwide, and remains a major cause of death and disability. Hypertension is a leading risk factor for dementia, including Alzheimer disease and Alzheimer disease-related dementias. Although this association is well-established, the mechanisms underlying hypertension-induced cognitive decline remain poorly understood. By exploring the mechanisms mediating the detrimental effects of hypertension on the brain, studies have aimed to provide therapeutic insights and strategies on how to protect the brain from the effects of blood pressure elevation. In this review, we focus on the basic mechanisms contributing to the cerebrovascular adaptions to elevated blood pressure and hypertension-induced microvascular injury. We also assess the cellular mechanisms of neurovascular unit dysfunction, focusing on the premise that cognitive impairment ensues when the dynamic metabolic demands of neurons are not met due to neurovascular uncoupling, and summarize cognitive deficits across various rodent models of hypertension as a resource for investigators. Despite significant advances in antihypertensive therapy, hypertension remains a critical risk factor for cognitive decline, and several questions remain about the development and progression of hypertension-induced cognitive impairment.

Spatio-temporal dynamics of microglia phenotype in human and murine cSVD: impact of acute and chronic hypertensive states

Vascular risk factors such as chronic hypertension are well-established major modifiable factors for the development of cerebral small vessel disease (cSVD). In the present study, our focus was the investigation of cSVD-related phenotypic changes in microglia in human disease and in the spontaneously hypertensive stroke-prone rat (SHRSP) model of cSVD. Our examination of cortical microglia in human post-mortem cSVD cortical tissue revealed distinct morphological microglial features specific to cSVD. We identified enlarged somata, an increase in the territory occupied by thickened microglial processes, and an expansion in the number of vascular-associated microglia. In parallel, we characterized microglia in a rodent model of hypertensive cSVD along different durations of arterial hypertension, i.e., early chronic and late chronic hypertension. Microglial somata were already enlarged in early hypertension. In contrast, at late-stage chronic hypertension, they further exhibited elongated branches, thickened processes, and a reduced ramification index, mirroring the findings in human cSVD. An unbiased multidimensional flow cytometric analysis revealed phenotypic heterogeneity among microglia cells within the hippocampus and cortex. At early-stage hypertension, hippocampal microglia exhibited upregulated CD11b/c, P2Y12R, CD200R, and CD86 surface expression. Detailed analysis of cell subpopulations revealed a unique microglial subset expressing CD11b/c, CD163, and CD86 exclusively in early hypertension. Notably, even at early-stage hypertension, microglia displayed a higher association with cerebral blood vessels. We identified several profound clusters of microglia expressing distinct marker profiles at late chronic hypertensive states. In summary, our findings demonstrate a higher vulnerability of the hippocampus, stage-specific microglial signatures based on morphological features, and cell surface protein expression in response to chronic arterial hypertension. These results indicate the diversity within microglia sub-populations and implicate the subtle involvement of microglia in cSVD pathogenesis.

Physical activity, sleep disorders, and type of work in the prevention of cognitive function decline in patients with hypertension

BACKGROUND

Hypertensive patients are likelier to have cognitive function decline (CFD). This study aimed to explore physical activity level, sleep disorders, and type of work that influenced intervention effects on cognitive function decline in hypertensive patients and to establish a decision tree model to analyze their predictive significance on the incidence of CFD in hypertensive patients.

METHODS

This cross-sectional study recruited patients with essential hypertension from several hospitals in Shandong Province from May 2022 to December 2022. Subject exclusion criteria included individuals diagnosed with congestive heart failure, valvular heart disease, cardiac surgery, hepatic and renal dysfunction, and malignancy. Recruitment is through multiple channels such as hospital medical and surgical outpatient clinics, wards, and health examination centers. Cognitive function was assessed using the Mini-Mental State Examination (MMSE), and sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Moreover, we obtained information on the patients' type of work through a questionnaire and their level of physical activity through the International Physical Activity Questionnaire (IPAQ).

RESULTS

The logistic regression analysis results indicate that sleep disorder is a significant risk factor for CFD in hypertension patients(OR:1.85, 95%CI:[1.16,2.94]), mental workers(OR:0.12, 95%CI: [0.04,0.37]) and those who perform both manual and mental workers(OR: 0.5, 95%CI: [0.29,0.86]) exhibit protective effects against CFD. Compared to low-intensity, moderate physical activity(OR: 0.53, 95%CI: [0.32,0.87]) and high-intensity physical activity(OR: 0.26, 95%CI: [0.12,0.58]) protects against CFD in hypertension patients. The importance of predictors in the decision tree model was ranked as follows: physical activity level (54%), type of work (27%), and sleep disorders (19%). The area under the ROC curves the decision tree model predicted was 0.72 [95% CI: 0.68 to 0.76].

CONCLUSION

Moderate and high-intensity physical activity may reduce the risk of developing CFD in hypertensive patients. Sleep disorders is a risk factor for CFD in hypertensive patients. Hypertensive patients who engage in mental work and high-intensity physical activity effectively mitigate the onset of CFD in hypertensive patients.

Etiology of White Matter Hyperintensities in Autosomal Dominant and Sporadic Alzheimer Disease

Importance

Increased white matter hyperintensity (WMH) volume is a common magnetic resonance imaging (MRI) finding in both autosomal dominant Alzheimer disease (ADAD) and late-onset Alzheimer disease (LOAD), but it remains unclear whether increased WMH along the AD continuum is reflective of AD-intrinsic processes or secondary to elevated systemic vascular risk factors.

Objective

To estimate the associations of neurodegeneration and parenchymal and vessel amyloidosis with WMH accumulation and investigate whether systemic vascular risk is associated with WMH beyond these AD-intrinsic processes.

Design, Setting, and Participants

This cohort study used data from 3 longitudinal cohort studies conducted in tertiary and community-based medical centers-the Dominantly Inherited Alzheimer Network (DIAN; February 2010 to March 2020), the Alzheimer's Disease Neuroimaging Initiative (ADNI; July 2007 to September 2021), and the Harvard Aging Brain Study (HABS; September 2010 to December 2019).

Main Outcome and Measures

The main outcomes were the independent associations of neurodegeneration (decreases in gray matter volume), parenchymal amyloidosis (assessed by amyloid positron emission tomography), and vessel amyloidosis (evidenced by cerebral microbleeds [CMBs]) with cross-sectional and longitudinal WMH.

Results

Data from 3960 MRI sessions among 1141 participants were included: 252 pathogenic variant carriers from DIAN (mean [SD] age, 38.4 [11.2] years; 137 [54%] female), 571 older adults from ADNI (mean [SD] age, 72.8 [7.3] years; 274 [48%] female), and 318 older adults from HABS (mean [SD] age, 72.4 [7.6] years; 194 [61%] female). Longitudinal increases in WMH volume were greater in individuals with CMBs compared with those without (DIAN: t = 3.2 [P = .001]; ADNI: t = 2.7 [P = .008]), associated with longitudinal decreases in gray matter volume (DIAN: t = -3.1 [P = .002]; ADNI: t = -5.6 [P < .001]; HABS: t = -2.2 [P = .03]), greater in older individuals (DIAN: t = 6.8 [P < .001]; ADNI: t = 9.1 [P < .001]; HABS: t = 5.4 [P < .001]), and not associated with systemic vascular risk (DIAN: t = 0.7 [P = .40]; ADNI: t = 0.6 [P = .50]; HABS: t = 1.8 [P = .06]) in individuals with ADAD and LOAD after accounting for age, gray matter volume, CMB presence, and amyloid burden. In older adults without CMBs at baseline, greater WMH volume was associated with CMB development during longitudinal follow-up (Cox proportional hazards regression model hazard ratio, 2.63; 95% CI, 1.72-4.03; P < .001).

Conclusions and Relevance

The findings suggest that increased WMH volume in AD is associated with neurodegeneration and parenchymal and vessel amyloidosis but not with elevated systemic vascular risk. Additionally, increased WMH volume may represent an early sign of vessel amyloidosis preceding the emergence of CMBs.

Assessment of cerebral autoregulatory function and inter-hemispheric blood flow in older adults with internal carotid artery stenosis using transcranial Doppler sonography-based measurement of transient hyperemic response after carotid artery compression

Unhealthy vascular aging promotes atherogenesis, which may lead to significant internal carotid artery stenosis (CAS) in 5 to 7.5% of older adults. The pathogenic factors that promote accelerated vascular aging and CAS also affect the downstream portion of the cerebral microcirculation in these patients. Primary treatments of significant CAS are eversion endarterectomy or endarterectomy with patch plasty. Factors that determine adequate hemodynamic compensation and thereby the clinical consequences of CAS as well as medical and surgical complications of carotid reconstruction surgery likely involve the anatomy of the circle of Willis (CoW), the magnitude of compensatory inter-hemispheric blood flow, and the effectiveness of cerebral microcirculatory blood flow autoregulation. This study aimed to test two hypotheses based on this theory. First, we hypothesized that patients with symptomatic and asymptomatic CAS would exhibit differences in autoregulatory function and inter-hemispheric blood flow. Second, we predicted that anatomically compromised CoW would associate with impaired inter-hemispheric blood flow compensation. We enrolled older adults with symptomatic or asymptomatic internal CAS (>70% NASCET criteria; n = 46) and assessed CoW integrity by CT angiography. We evaluated transient hyperemic responses in the middle cerebral arteries (MCA) after common carotid artery compression (CCC; 10 s) by transcranial Doppler sonography (TCD). We compared parameters reflecting autoregulatory function (e.g., transient hyperemic response ratio [THRR], return to baseline time [RTB], changes of vascular resistance) and inter-hemispheric blood flow (residual blood flow velocity). Our findings revealed that CAS was associated with impaired cerebral vascular reactivity. However, we did not observe significant differences in autoregulatory function or inter-hemispheric blood flow between patients with symptomatic and asymptomatic CAS. Moreover, anatomically compromised CoW did not significantly affect these parameters. Notably, we observed an inverse correlation between RTB and THRR, and 49% of CAS patients exhibited a delayed THRR, which associated with decreased inter-hemispheric blood flow. Future studies should investigate how TCD-based evaluation of autoregulatory function and inter-hemispheric blood flow can be used to optimize surgical techniques and patient selection for internal carotid artery revascularization.

Unveiling the dual role of autophagy in vascular remodelling and its related diseases

Vascular remodelling is an adaptive response to physiological and pathological stimuli that leads to structural and functional changes in the vascular intima, media, and adventitia. Pathological vascular remodelling is a hallmark feature of numerous vascular diseases, including atherosclerosis, hypertension, abdominal aortic aneurysm, pulmonary hypertension and preeclampsia. Autophagy is critical in maintaining cellular homeostasis, and its dysregulation has been implicated in the pathogenesis of various diseases, including vascular diseases. However, despite emerging evidence, the role of autophagy and its dual effects on vascular remodelling has garnered limited attention. Autophagy can exert protective and detrimental effects on the vascular intima, media and adventitia, thereby substantially influencing the course of vascular remodelling and its related vascular diseases. Currently, there has not been a review that thoroughly describes the regulation of autophagy in vascular remodelling and its impact on related diseases. Therefore, this review aimed to bridge this gap by focusing on the regulatory roles of autophagy in diseases related to vascular remodelling. This review also summarizes recent advancements in therapeutic agents targeting autophagy to regulate vascular remodelling. Additionally, this review offers an overview of recent breakthroughs in therapeutic agents targeting autophagy to regulate vascular remodelling. A deeper understanding of how autophagy orchestrates vascular remodelling can drive the development of targeted therapies for vascular diseases.