Association of Blood Pressure Lowering With Incident Dementia or Cognitive Impairment: A Systematic Review and Meta-analysis

Antihypertensive medication classes and risk of incident dementia in primary care patients: a longitudinal cohort study in the Netherlands

Background

Hypertension is a modifiable risk factor for dementia affecting over 70% of individuals older than 60. Lowering dementia risk through preferential treatment with antihypertensive medication (AHM) classes that are otherwise equivalent in indication could offer a cost-effective, safe, and accessible approach to reducing dementia incidence globally. Certain AHM-classes have been associated with lower dementia risk, potentially attributable to angiotensin-II-receptor (Ang-II) stimulating properties. Previous study results have been inconclusive, possibly due to heterogeneous methodology and limited power. We aimed to comprehensively investigate associations between AHM (sub-)classes and dementia risk using large-scale continuous, real-world prescription and outcome data from primary care.

Methods

We used data from three Dutch General Practice Registration Networks. Primary endpoints were clinical diagnosis of incident all-cause dementia and mortality. Using Cox regression analysis with time-dependent covariates, we compared the use of angiotensin-converting enzyme inhibitors (ACEi) to angiotensin receptor blockers (ARBs), beta blockers, calcium channel blockers (CCBs), and diuretics; and Ang-II-stimulating- to Ang-II-inhibiting AHM.

Findings

Of 133,355 AHM-using participants, 5877 (4.4%) developed dementia, and 14,079 (10.6%) died during a median follow-up of 7.6 [interquartile range = 4.1-11.0] years. Compared to ACEi, ARBs [HR = 0.86 (95% CI = 0.80-0.92)], beta blockers [HR = 0.81 (95% CI = 0.75-0.87)], CCBs [HR = 0.77 (95% CI = 0.71-0.84)], and diuretics [HR = 0.65 (95% CI = 0.61-0.70)] were associated with significantly lower dementia risks. Regarding competing risk of death, beta blockers [HR = 1.21 (95% CI = 1.15-1.27)] and diuretics [HR = 1.69 (95% CI = 1.60-1.78)] were associated with higher, CCBs with similar, and ARBs with lower [HR = 0.83 (95% CI = 0.80-0.87)] mortality risk. Dementia [HR = 0.88 (95% CI = 0.82-0.95)] and mortality risk [HR = 0.86 (95% CI = 0.82-0.91)] were lower for Ang-II-stimulating versus Ang-II-inhibiting AHM. There were no interactions with sex, diabetes, cardiovascular disease, and number of AHM used.

Interpretation

Among patients receiving AHM, ARBs, CCBs, and Ang-II-stimulating AHM were associated with lower dementia risk, without excess mortality explaining these results. Extensive subgroup and sensitivity analyses suggested that confounding by indication did not importantly influence our findings. Dementia risk may be influenced by AHM-classes' angiotensin-II-receptor stimulating properties. An RCT comparing BP treatment with different AHM classes with dementia as outcome is warranted.

Funding

Netherlands Organisation for Health, Research and Development (ZonMw); Stoffels-Hornstra Foundation.

The Association Between Cardiometabolic Risk and Cognitive Function Among Older Americans and Chinese

BACKGROUND

Cardiometabolic risk (CMR) is associated with cognitive health, but the association can be affected by broader social, economic, and medical contexts. The United States and China have very different developmental and epidemiological histories, and thus CMR among older people could be linked to cognitive function differently in the 2 countries.

METHODS

Cross-sectional and longitudinal ordinary least squares regression models were estimated for each country using nationally representative samples of populations over age 50: 7 430/4 474 Americans and 6 108/3 655 Chinese in the cross-sectional/longitudinal samples.

RESULTS

In the United States, higher CMR is associated with worse cognitive function (b = -0.08, p < .016). Longitudinally, CMR increase is associated with worse cognitive function at a marginally significant level (b = -0.10, p = .055). No relationship between CMR level or change and cognitive function is observed in China. Higher education levels are linked to better cognitive function and slower cognitive decline in both countries. Unlike older Americans, relative to those with very low education levels, among older Chinese with the highest education level, a higher CMR links to better cognitive function (b = 0.63, p = .013) and slower cognitive decline (b = 0.35, p = .062); Nevertheless, a rapid increase in CMR is additionally harmful (b = -0.54, p = .050) for cognitive function and may lead to faster cognitive decline (b = -0.35, p = .079).

CONCLUSIONS

The significant relationship between CMR and cognitive function in the United States suggests the importance of monitoring and controlling CMR factors at older ages. The insignificant relationship in China may be explained by the high CMR among those with high education levels, highlighting the need for improving cardiometabolic health through education and promoting healthy lifestyles.

Nimodipine Protects Vascular and Cognitive Function in an Animal Model of Cerebral Small Vessel Disease

BACKGROUND

Cerebral small vessel disease is a common cause of vascular cognitive impairment and dementia. There is an urgent need for preventative treatments for vascular cognitive impairment and dementia, and reducing vascular dysfunction may provide a therapeutic route. Here, we investigate whether the chronic administration of nimodipine, a central nervous system-selective dihydropyridine calcium channel blocking agent, protects vascular, metabolic, and cognitive function in an animal model of cerebral small vessel disease, the spontaneously hypertensive stroke-prone rat.

METHODS

Male spontaneously hypertensive stroke-prone rats were randomly allocated to receive either a placebo (n=24) or nimodipine (n=24) diet between 3 and 6 months of age. Animals were examined daily for any neurological deficits, and vascular function was assessed in terms of neurovascular and neurometabolic coupling at 3 and 6 months of age, and cerebrovascular reactivity at 6 months of age. Cognitive function was evaluated using the novel object recognition test at 6 months of age.

RESULTS

Six untreated control animals were terminated prematurely due to strokes, including one due to seizure, but no treated animals experienced strokes and so had a higher survival (P=0.0088). Vascular function was significantly impaired with disease progression, but nimodipine treatment partially preserved neurovascular coupling and neurometabolic coupling, indicated by larger (P<0.001) and more prompt responses (P<0.01), and less habituation upon repeated stimulation (P<0.01). Also, animals treated with nimodipine showed greater cerebrovascular reactivity, indicated by larger dilation of arterioles (P=0.015) and an increase in blood flow velocity (P=0.001). This protection of vascular and metabolic function achieved by nimodipine treatment was associated with better cognitive function (P<0.001) in the treated animals.

CONCLUSIONS

Chronic treatment with nimodipine protects from strokes, and vascular and cognitive deficits in spontaneously hypertensive stroke-prone rat. Nimodipine may provide an effective preventive treatment for stroke and cognitive decline in cerebral small vessel disease.

Effect of vigorous-intensity physical activity on incident cognitive impairment in high-risk hypertension

INTRODUCTION

We investigated the effect vigorous physical activity (VPA) on the risk of incident mild cognitive impairment (MCI) and probable dementia among individuals with high-risk hypertension.

METHODS

Baseline self-reported frequency of VPA was categorized into low VPA (<1 session/week), and high VPA (≥1 session/week). We used multivariate Cox regression analysis to examine the association of VPA categories with incident MCI and probable dementia events.

RESULTS

Participants in the high VPA category, compared with low VPA, experienced lower events rates (per 1000 person-years) of MCI (13.9 vs 19.7), probable dementia (6.3 vs 9.0), and MCI/probable dementia (18.5 vs 25.8). In the multivariate Cox regression model, high VPA, compared with low VPA, was associated with lower risk of MCI, probable dementia, and MCI/probable dementia (HR [95% CI]: 0.81 [0.68-0.97], 0.80 [0.63-1.03], and 0.82 [0.70-0.96]), respectively.

DISCUSSION

This study provides evidence that VPA may preserve cognitive function in high-risk patients with hypertension.

HIGHLIGHTS

Hypertension is associated with an increased risk of cognitive impairment Physical activity (PA) is associated with a lower risk of decline in cognition The effect of ≥1 sessions of vigorous-intensity PA (VPA) per week was assessed This analysis included SPRINT MIND trial participants with high-risk hypertension ≥1 VPA sessions/week was associated with lower risk of future cognitive impairment.

Exploring the association between number of teeth, food intake, and cognitive function: A 9-year longitudinal study

OBJECTIVES

This study aimed to investigate the association between the number of teeth, food intake, and cognitive function in Japanese community-dwelling older adults.

METHODS

This 9-year longitudinal study included a total of 293 analyzable participants who participated in baseline and follow-up surveys. Dental status (number of teeth and periodontal pocket depth), dietary assessment using the brief-type self-administered diet history questionnaire, cognitive function, and the following confounding factors were evaluated: educational level, financial satisfaction, living situation, smoking and drinking habits, history of chronic diseases, apolipoprotein E-ε4 carrier, body mass index, handgrip strength, instrumental activities of daily living, and depressive symptomatology. The Japanese version of the Montreal Cognitive Assessment was used to evaluate cognitive function. A multinomial logistic regression analysis for the intake level of each food categorized into three groups (low, moderate, high), and a generalized estimating equation (GEE) for cognitive function over nine years were performed.

RESULTS

After controlling for confounding factors, the number of teeth was shown to be associated with the intake of green-yellow vegetables and meat. Furthermore, the GEE indicated that the lowest quartile of intake of green-yellow vegetables significantly associated with lower cognitive function (unstandardized regression coefficient [B] = -0.96, 95 % confidence interval [CI]: -1.72 to -0.20), and the lowest quartile of intake of meat significantly associated with lower cognitive function (B = -1.42, 95 % CI: -2.27 to -0.58).

CONCLUSIONS

The intake of green and yellow vegetables and meat, which is influenced by the number of teeth, was associated with cognitive function in Japanese community-dwelling older adults.

CLINICAL SIGNIFICANCE

There are few studies that have examined the association between oral health, food intake, and cognitive function. This 9-year longitudinal study suggests that it is important to maintain natural teeth to enable the functional means to consume green-yellow vegetables and meat, and thereby help maintain cognitive function.

Modifiable risk factors of inequalities in hypertension: analysis of 100 million health checkups recipients

Inequalities in health behaviors are thought to contribute to inequalities in hypertension. This study examined the extent to which modifiable mediating factors explain income inequalities in hypertension. This repeated cross-sectional study used data from National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) from 2009 to 2015. Those aged between 40 and 74 were enrollees in the Specific Health Checkups. Hypertension was defined as systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90, or the use of antihypertensive medication. The mediating effects of exercise, obesity, smoking, and alcohol drinking on the association between income, as an indicator of SES, and hypertension were determined by the Karlson-Holm-Breen (KHB) method. The mean age of the 68,684,025 men and 59,118,221 women was 54.7 (SD = 9.6) and 56.7 (SD = 10.0) years, respectively. Prevalence of hypertension was higher in the lowest income group (48.6% for men, 40.2% for women) than in the highest income group (33.3% for men, 21.5% for women). Inequalities tended to increase over time. Inequalities were larger among those who did not use antihypertensive medication. Modifiable risks explained 10.6% of the association between income and hypertension for men and 15.1% for women. In men, drinking and obesity explained 8.8% and 5.5% of the inequalities in hypertension, respectively. In women, obesity explained 18.8%. Exercise increased the proportion mediated over time. Smoking explained 5.5% among women taking antihypertensive medication. There were health inequalities in hypertension among Japanese adults, and the modifiable risk factors partially explained the inequalities.

Effect of Population-Level Blood Pressure Treatment Strategies on Cardiovascular and Cognitive Outcomes

BACKGROUND

The large and increasing number of adults living with dementia is a pressing societal priority, which may be partially mitigated through improved population-level blood pressure (BP) control. We explored how tighter population-level BP control affects the incidence of atherosclerotic cardiovascular disease (ASCVD) events and dementia.

METHODS

Using an open-source ASCVD and dementia simulation analysis platform, the Michigan Chronic Disease Simulation Model, we evaluated how optimal implementation of 2 BP treatments based on the Eighth Joint National Committee recommendations and SPRINT (Systolic Blood Pressure Intervention Trial) protocol would influence population-level ASCVD events, global cognitive performance, and all-cause dementia. We simulated 3 populations (usual care, Eighth Joint National Committee based, SPRINT based) using nationally representative data to annually update risk factors and assign ASCVD events, global cognitive performance scores, and dementia, applying different BP treatments in each population. We tabulated total ASCVD events, global cognitive performance, all-cause dementia, optimal brain health, and years lived in each state per population.

RESULTS

Optimal implementation of SPRINT-based BP treatment strategy, compared with usual care, reduced ASCVD events in the United States by ≈77 000 per year and produced 0.4 more years of stroke- or myocardial infarction-free survival when averaged across all Americans. Population-level gains in years lived free of ASCVD events were greater for SPRINT-based than Eighth Joint National Committee-based treatment. Survival and years spent with optimal brain health improved with optimal SPRINT-based BP treatment implementation versus usual care: the average patient with hypertension lived 0.19 additional years and 0.3 additional years in optimal brain health. SPRINT-based BP treatment increased the number of years lived without dementia (by an average of 0.13 years/person with hypertension), but increased the total number of individuals with dementia, mainly through more adults surviving to advanced ages.

CONCLUSIONS

Tighter BP control likely benefits most individuals but is unlikely to reduce dementia prevalence and might even increase the number of older adults living with dementia.

An assessment of the mediating role of hypertension in the effect of long-term air pollution exposure on dementia

Background

Growing evidence links air pollution exposure to the risk of dementia. We hypothesized that hypertension may partially mediate this effect.

Methods

We previously documented an association between air pollution and dementia in the Ginkgo Evaluation of Memory Study, a randomized, placebo-controlled trial of 3069 adults ≥75 years across four US sites who were evaluated for dementia every 6 months from 2000-2008. We utilized a two-stage regression approach for causal mediation analysis to decompose the total effect of air pollution on dementia into its natural direct and indirect effect through prevalent hypertension. Exposure to air pollution in the 10 or 20 years before enrollment was assigned using estimates from fine-scale spatial-temporal models for PM2.5, PM10, and NO2. We used Poisson regression models for hypertension and Cox proportional hazard models for time-to-incident all-cause dementia, adjusting for a priori confounders.

Results

Participants were free of mild cognitive impairment at baseline (n = 2564 included in analyses); 69% had prevalent hypertension at baseline. During follow-up, 12% developed all-cause dementia (Alzheimer's disease [AD] = 212; vascular dementia with or without AD [VaD/AD mixed] = 97). We did not find an adverse effect of any air pollutant on hypertension. Hypertension was associated with VaD/AD mixed (HR, 1.92 [95% CI = 1.14, 3.24]) but not AD. We did not observe mediation through hypertension for the effect of any pollutant on dementia outcomes.

Conclusions

The lack of mediated effect may be due to other mechanistic pathways and the minimal effect of air pollution on hypertension in this cohort of older adults.

Relationship Between Physical Exercise and Cognitive Function Among Older Adults in China: Cross-Sectional Population-Based Study

BACKGROUND

The existing literature reveals several significant knowledge gaps that hinder health care providers in formulating exercise prescriptions for cognitive health.

OBJECTIVE

This study endeavors to elucidate the relationship between the level of physical activity and cognitive function in older adults in China. Moreover, it seeks to explore the associations between distinct exercise behaviors-such as exercise types, the purpose motivating engagement in exercise, the accessibility of exercise fields, and the inclination toward exercise-and cognitive function.

METHODS

Using data from the China Longitudinal Aging Social Survey (CLASS conducted in 2016, cognitive function was meticulously assessed through the modified Chinese version of the Mini-Mental State Examination, encompassing measures of orientation, memory, and calculation. Using self-report structured questionnaires, a myriad of information about physical activity during leisure time, exercise engagement, exercise intensity, primary exercise types, reasons for exercise participation, availability of sports facilities, and exercise willingness was diligently gathered. Robust ordinary least squares regression models were then used to compute coefficients along with 95% CIs.

RESULTS

A discernible inverted U-shaped trend in cognitive scores emerged as the level of physical activity surpassed the threshold of 500 metabolic equivalents of task (MET) minutes per week. Notably, individuals with a physical activity level between 500 and 999 MET minutes per week exhibited a coefficient of 0.31 (95% CI 0.09 to 0.54), those with a physical activity level between 1000 and 1499 MET minutes per week displayed a coefficient of 0.75 (95% CI 0.52 to 0.97), and those with a physical activity level above 1500 MET minutes per week demonstrated a coefficient of 0.45 (95% CI 0.23 to 0.68). Older individuals engaging in exercise at specific MET levels showcased superior cognitive function compared to their inactive counterparts. Furthermore, individuals driven by exercise motivations aimed at enhancing physical fitness and health, as well as those using sports facilities or public spaces for exercise, exhibited notably higher cognitive function scores.

CONCLUSIONS

The findings underscore the potential of exercise as a targeted intervention for the prevention and treatment of dementia or cognitive decline associated with aging in older individuals. Leveraging these insights to formulate informed exercise recommendations holds promise in addressing a significant public health challenge linked to aging populations.

Specification curve analysis to identify heterogeneity in risk factors for dementia: findings from the UK Biobank

BACKGROUND

In 2020, the Lancet Commission identified 12 risk factors as priorities for prevention of dementia, and other studies identified APOE e4/e4 genotype and family history of Alzheimer's disease strongly associated with dementia outcomes; however, it is unclear how robust these relationships are across dementia subtypes and analytic scenarios. Specification curve analysis (SCA) is a new tool to probe how plausible analytical scenarios influence outcomes.

METHODS

We evaluated the heterogeneity of odds ratios for 12 risk factors reported from the Lancet 2020 report and two additional strong associated non-modifiable factors (APOE e4/e4 genotype and family history of Alzheimer's disease) with dementia outcomes across 450,707 UK Biobank participants using SCA with 5357 specifications across dementia subtypes (outcomes) and analytic models (e.g., standard demographic covariates such as age or sex and/or 14 correlated risk factors).

RESULTS

SCA revealed variable dementia risks by subtype and age, with associations for TBI and APOE e4/e4 robust to model specification; in contrast, diabetes showed fluctuating links with dementia subtypes. We found that unattributed dementia participants had similar risk factor profiles to participants with defined subtypes.

CONCLUSIONS

We observed heterogeneity in the risk of dementia, and estimates of risk were influenced by the inclusion of a combination of other modifiable risk factors; non-modifiable demographic factors had a minimal role in analytic heterogeneity. Future studies should report multiple plausible analytic scenarios to test the robustness of their association. Considering these combinations of risk factors could be advantageous for the clinical development and evaluation of novel screening models for different types of dementia.

Angiotensin Converting Enzyme (ACE) expression in microglia reduces amyloid β deposition and neurodegeneration by increasing SYK signaling and endolysosomal trafficking

Genome-wide association studies (GWAS) have identified many gene polymorphisms associated with an increased risk of developing Late Onset Alzheimer's Disease (LOAD). Many of these LOAD risk-associated alleles alter disease pathogenesis by influencing microglia innate immune responses and lipid metabolism. Angiotensin Converting Enzyme (ACE), a GWAS LOAD risk-associated gene best known for its role in regulating systemic blood pressure, also enhances innate immunity and lipid processing in peripheral myeloid cells, but a role for ACE in modulating the function of myeloid-derived microglia remains unexplored. Using novel mice engineered to express ACE in microglia and CNS associated macrophages (CAMs), we find that ACE expression in microglia reduces Aβ plaque load, preserves vulnerable neurons and excitatory synapses, and greatly reduces learning and memory abnormalities in the 5xFAD amyloid mouse model of Alzheimer's Disease (AD). ACE-expressing microglia show enhanced Aβ phagocytosis and endolysosomal trafficking, increased clustering around amyloid plaques, and increased SYK tyrosine kinase activation downstream of the major Aβ receptors, TREM2 and CLEC7A. Single microglia sequencing and digital spatial profiling identifies downstream SYK signaling modules that are expressed by ACE expression in microglia that mediate endolysosomal biogenesis and trafficking, mTOR and PI3K/AKT signaling, and increased oxidative phosphorylation, while gene silencing or pharmacologic inhibition of SYK activity in ACE-expressing microglia abrogates the potentiated Aβ engulfment and endolysosomal trafficking. These findings establish a role for ACE in enhancing microglial immune function and they identify a potential use for ACE-expressing microglia as a cell-based therapy to augment endogenous microglial responses to Aβ in AD.

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.

Association between untreated and treated blood pressure levels and cognitive decline in community-dwelling middle-aged and older adults in China: a longitudinal study

BACKGROUND

Optimal blood pressure (BP) levels to reduce the long-term risk of cognitive decline remains controversial. We aimed to investigate the association between BP and anti-hypertensive treatment status with cognitive decline in older adults.

METHODS

This study used data from the China Health and Retirement Longitudinal Study. Cognitive function was assessed at year 2011, 2013, 2015, and 2018. Global cognitive Z-score was calculated as the average score of episodic memory and mental intactness. BP were measured at the first and second wave. Pulse pressure (PP) was calculated as systolic BP (SBP) minus diastolic BP. Cumulative BP was calculated as the area under the curve using BP measurements from 2011 to 2013. Linear mixed models were used to assess the longitudinal association between BP-related measurements and cognitive decline.

RESULTS

We included 11,671 participants (47.3% men and mean age 58.6 years). Individual with BP > 140/90 mm Hg or taking anti-hypertensive medication were independently associated with accelerated cognitive decline (β=-0.014, 95% CI: -0.020 to -0.007). Individuals with anti-hypertensive medication use, but with controlled SBP to less than 120 mm Hg did not have a significantly increased risk of cognitive decline compared with normotension (β=-0.003, 95% CI: -0.021 to 0.014). Individuals on anti-hypertensive treatment with PP of more than 70 mm Hg had a significantly higher risk of cognitive decline (β=-0.033, 95% CI: -0.045 to -0.020). Regardless of anti-hypertensive treatment status, both elevated baseline and cumulative SBP and PP were found to be independently associated with accelerated cognitive decline.

CONCLUSIONS

Cumulatively elevated SBP, PP and uncontrolled BP were associated with subsequent cognitive decline. Effectively controlling BP with anti-hypertensive treatment may be able to preserve cognitive decline in older adults.

Genetic Complexities of Cerebral Small Vessel Disease, Blood Pressure, and Dementia

Importance

Vascular disease is a treatable contributor to dementia risk, but the role of specific markers remains unclear, making prevention strategies uncertain.

Objective

To investigate the causal association between white matter hyperintensity (WMH) burden, clinical stroke, blood pressure (BP), and dementia risk, while accounting for potential epidemiologic biases.

Design, Setting, and Participants

This study first examined the association of genetically determined WMH burden, stroke, and BP levels with Alzheimer disease (AD) in a 2-sample mendelian randomization (2SMR) framework. Second, using population-based studies (1979-2018) with prospective dementia surveillance, the genetic association of WMH, stroke, and BP with incident all-cause dementia was examined. Data analysis was performed from July 26, 2020, through July 24, 2022.

Exposures

Genetically determined WMH burden and BP levels, as well as genetic liability to stroke derived from genome-wide association studies (GWASs) in European ancestry populations.

Main Outcomes and Measures

The association of genetic instruments for WMH, stroke, and BP with dementia was studied using GWASs of AD (defined clinically and additionally meta-analyzed including both clinically diagnosed AD and AD defined based on parental history [AD-meta]) for 2SMR and incident all-cause dementia for longitudinal analyses.

Results

In 2SMR (summary statistics-based) analyses using AD GWASs with up to 75 024 AD cases (mean [SD] age at AD onset, 75.5 [4.4] years; 56.9% women), larger WMH burden showed evidence for a causal association with increased risk of AD (odds ratio [OR], 1.43; 95% CI, 1.10-1.86; P = .007, per unit increase in WMH risk alleles) and AD-meta (OR, 1.19; 95% CI, 1.06-1.34; P = .008), after accounting for pulse pressure for the former. Blood pressure traits showed evidence for a protective association with AD, with evidence for confounding by shared genetic instruments. In the longitudinal (individual-level data) analyses involving 10 699 incident all-cause dementia cases (mean [SD] age at dementia diagnosis, 74.4 [9.1] years; 55.4% women), no significant association was observed between larger WMH burden and incident all-cause dementia (hazard ratio [HR], 1.02; 95% CI, 1.00-1.04; P = .07). Although all exposures were associated with mortality, with the strongest association observed for systolic BP (HR, 1.04; 95% CI, 1.03-1.06; P = 1.9 × 10-14), there was no evidence for selective survival bias during follow-up using illness-death models. In secondary analyses using polygenic scores, the association of genetic liability to stroke, but not genetically determined WMH, with dementia outcomes was attenuated after adjusting for interim stroke.

Conclusions

These findings suggest that WMH is a primary vascular factor associated with dementia risk, emphasizing its significance in preventive strategies for dementia. Future studies are warranted to examine whether this finding can be generalized to non-European populations.

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.

Treating Hypertension: Important for Heart Health, Fundamental for Brain Health

The Brain Health crisis stands as one of humankind's most pressing threats, with age-related noncommunicable brain diseases, particularly stroke, and dementia, affecting hundreds of millions annually and jeopardizing the economic well-being of populations worldwide. Epidemiological studies indicate that ≈40% of dementia and 60% of stroke cases are attributable to modifiable risk factors. In this Comments and Opinions article, we underscore the pivotal role of blood pressure (BP) control in reducing suffering, enhancing economic well-being, and promoting healthy longevity for populations worldwide. Emphasizing that BP control is crucial for both brain and heart health, it advocates for heightened awareness, positioning hypertension as a primary focus for preventing dementia and stroke with potential global impact. Despite its significance, BP control encounters global challenges, with proportions of the population maintaining adequately controlled hypertension ranging from 23% to 90%. The World Health Organization estimated that 46% of the 1.28 billion people with hypertension are unaware of their elevated BP. Given the notable disparities in BP management, addressing BP management also contributes to combating significant health inequalities. The next time you are faced with a patient anxious about the prospect of experiencing a fate similar to a parent with dementia or a sister with a stroke, we suggest a straightforward answer for health care providers: start ensuring BP control. BP is a matter of brain health, and it is a matter of our economic future.

Leukoaraiosis: Epidemiology, Imaging, Risk Factors, and Management of Age-Related Cerebral White Matter Hyperintensities

Leukoaraiosis (LA) manifests as cerebral white matter hyperintensities on T2-weighted magnetic resonance imaging scans and corresponds to white matter lesions or abnormalities in brain tissue. Clinically, it is generally detected in the early 40s and is highly prevalent globally in individuals aged >60 years. From the imaging perspective, LA can present as several heterogeneous forms, including punctate and patchy lesions in deep or subcortical white matter; lesions with periventricular caps, a pencil-thin lining, and smooth halo; as well as irregular lesions, which are not always benign. Given its potential of having deleterious effects on normal brain function and the resulting increase in public health burden, considerable effort has been focused on investigating the associations between various risk factors and LA risk, and developing its associated clinical interventions. However, study results have been inconsistent, most likely due to potential differences in study designs, neuroimaging methods, and sample sizes as well as the inherent neuroimaging heterogeneity and multi-factorial nature of LA. In this article, we provided an overview of LA and summarized the current knowledge regarding its epidemiology, neuroimaging classification, pathological characteristics, risk factors, and potential intervention strategies.

Association between hemoglobin trajectories and the incidence of dementia in a cohort of females aged 55-79 years

PURPOSE

To assess the association between pattern changes in hemoglobin levels over time and the incidence of dementia using trajectories in females aged 55-79 years.

MATERIALS AND METHODS

We conducted a retrospective cohort study using females of aged 55-79 years from the National Health Insurance Service National Health Screening Cohort in Korea. To identify hemoglobin trajectories over eight years (2002-2009), we performed a three-step approach comprising measures of change, factor analysis, and cluster analysis. Univariate and multivariate Cox proportional hazard models were used to assess the associations between hemoglobin trajectories and the incidence of dementia.

RESULTS

We included 20,195 of 235,742 female participants. New dementia (N = 2664) was developed during follow-up period (2010-2015). Five hemoglobin trajectories were identified: high, mid, low, increasing, and decreasing. With high as a reference, the hazard ratios (HRs) for low and decreasing trajectories were significant, 1.28 (95% confidence interval [CI], 1.13-1.45) and 1.21 (95% CI, 1.10-1.34) in univariate models, respectively. However, only the HR for the decreasing trajectory was significant, 1.12 (95% CI, 1.01-1.24) after adjustment for confounders.

CONCLUSION

The decreasing trajectory of hemoglobin levels within the normal range was associated with dementia. Even females aged 55-79 years without anemia might be vulnerable to dementia development risk.

Spontaneous brain activity in the hippocampal regions could characterize cognitive impairment in patients with Parkinson's disease

OBJECTIVE

This study aimed to investigate whether spontaneous brain activity can be used as a prospective indicator to identify cognitive impairment in patients with Parkinson's disease (PD).

METHODS

Resting-state functional magnetic resonance imaging (RS-fMRI) was performed on PD patients. The cognitive level of patients was assessed by the Montreal Cognitive Assessment (MoCA) scale. The fractional amplitude of low-frequency fluctuation (fALFF) was applied to measure the strength of spontaneous brain activity. Correlation analysis and between-group comparisons of fMRI data were conducted using Rest 1.8. By overlaying cognitively characterized brain regions and defining regions of interest (ROIs) based on their spatial distribution for subsequent cognitive stratification studies.

RESULTS

A total of 58 PD patients were enrolled in this study. They were divided into three groups: normal cognition (NC) group (27 patients, average MoCA was 27.96), mild cognitive impairment (MCI) group (21 patients, average MoCA was 23.52), and severe cognitive impairment (SCI) group (10 patients, average MoCA was 17.3). It is noteworthy to mention that those within the SCI group exhibited the most advanced chronological age, with an average of 74.4 years, whereas the MCI group displayed a higher prevalence of male participants at 85.7%. It was found hippocampal regions were a stable representative brain region of cognition according to the correlation analysis between the fALFF of the whole brain and cognition, and the comparison of fALFF between different cognitive groups. The parahippocampal gyrus was the only region with statistically significant differences in fALFF among the three cognitive groups, and it was also the only brain region to identify MCI from NC, with an AUC of 0.673. The paracentral lobule, postcentral gyrus was the region that identified SCI from NC, with an AUC of 0.941. The midbrain, hippocampus, and parahippocampa gyrus was the region that identified SCI from MCI, with an AUC of 0.926.

CONCLUSION

The parahippocampal gyrus was the potential brain region for recognizing cognitive impairment in PD, specifically for identifying MCI. Thus, the fALFF of parahippocampal gyrus is expected to contribute to future study as a multimodal fingerprint for early warning.

Orthostatic blood pressure changes do not influence cognitive outcomes following intensive blood pressure control

BACKGROUND

Effects of intensive blood pressure (BP) control on cognitive outcomes in patients with excess orthostatic BP changes are unclear. We aimed to evaluate whether orthostatic BP changes modified the effects of BP intervention on cognitive impairment.

METHODS

We analyzed 8547 participants from the Systolic Blood Pressure Intervention Trial Memory and cognition IN Decreased Hypertension. Associations between orthostatic BP changes and incident cognitive outcomes were evaluated by restricted cubic spline curves based on Cox models. The interactions between orthostatic BP changes and intensive BP intervention were assessed.

RESULTS

The U-shaped associations were observed between baseline orthostatic systolic BP changes and cognitive outcomes. However, there were insignificant interactions between either change in orthostatic systolic BP (P for interaction = 0.81) or diastolic BP (P for interaction = 0.32) and intensive BP intervention for the composite outcome of probable dementia or mild cognitive impairment (MCI). The hazard ratio of intensive versus standard target for the composite cognitive outcome was 0.82 (95% CI 0.50-1.35) in those with an orthostatic systolic BP reduction of >20 mmHg and 0.41 (95% CI 0.21-0.80) in those with an orthostatic systolic BP increase of >20 mmHg. Results were similar for probable dementia and MCI. The annual changes in global cerebral blood flow (P for interaction = 0.86) consistently favored intensive BP treatment across orthostatic systolic BP changes.

CONCLUSION

Intensive BP control did not have a deteriorating effect on cognitive outcomes among hypertensive patients experiencing significant postural BP changes.

Cognitive Impairment in Heart Failure: A Heart Failure Society of America Scientific Statement

Cognitive impairment is common among adults with heart failure (HF), as both diseases are strongly related to advancing age and multimorbidity (including both cardiovascular and noncardiovascular conditions). Moreover, HF itself can contribute to alterations in the brain. Cognition is critical for a myriad of self-care activities that are necessary to manage HF, and it also has a major impact on prognosis; consequently, cognitive impairment has important implications for self-care, medication management, function and independence, and life expectancy. Attuned clinicians caring for patients with HF can identify clinical clues present at medical encounters that suggest cognitive impairment. When present, screening tests such as the Mini-Cog, and consideration of referral for comprehensive neurocognitive testing may be indicated. Management of cognitive impairment should focus on treatment of underlying causes of and contributors to cognitive impairment, medication management/optimization, and accommodation of deficiencies in self-care. Given its implications on care, it is important to integrate cognitive impairment into clinical decision making. Although gaps in knowledge and challenges to implementation exist, this scientific statement is intended to guide clinicians in caring for and meeting the needs of an increasingly complex and growing subpopulation of patients with HF.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Comorbid Conditions Are Associated With Cognitive Impairment in Native Hawaiians and Pacific Islanders

We examined the association between comorbid conditions and mild cognitive impairment (MCI) in Native Hawaiians and Pacific Islanders (NHPI) (n = 54). Cross-sectional, self-reported questionnaires were utilized to collect demographic, comorbid conditions, and MCI (via the AD8 index) data. Separate logistic regression models were conducted to investigate the relationship between comorbid conditions and MCI, adjusting for other covariates. We found significantly increased odds of MCI in those reporting high blood pressure (OR = 5.27; 95% CI: [1.36, 20.46]; p = 0.016), high cholesterol (OR = 7.30; 95% CI: [1.90, 28.14], p = 0.004), and prediabetes or borderline diabetes (OR = 4.53; 95% CI: [1.27, 16.16], p = 0.02) compared with those not reporting these respective conditions. These data show that hypertension, hypercholesterolemia, and prediabetes are associated with MCI in the NHPI community, suggesting that preventive strategies to reduce chronic conditions may also potentially slow cognitive decline in underrepresented/understudied NHPI.

Increased risk of dementia differs across cardiovascular diseases and types of dementia - Data from a nationwide study

AIMS

Dementia is a major health problem. Cardiovascular diseases (CVD) and risk factors are associated with incident dementia. However, whether there is an association among CVD, Alzheimer's disease (AD) and vascular dementia (VD) at the population level remains unclear.

METHODS

We analysed the association between CVD (heart failure [HF], atrial fibrillation [AF], myocardial infarction [MI], peripheral arterial disease, stroke and transient ischemic attack) and the incidence of dementia using nationwide FinnGen data of 218,192 individuals. The last follow-up information on dementia was available from October 2021.

RESULTS

The age at the end of the follow-up was 61.7 ± 17.1 years, and 53% were women. Overall, we observed 9701 (4.4%) dementia, 6323 (2.9%) AD and 1918 (0.7%) VD cases. Individuals with CVD had a higher risk of developing dementia than unexposed individuals. In the multivariable-adjusted Cox models, stroke was most strongly associated with dementia (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.6-1.8). CVD was more strongly associated with VD than with AD. Individuals with HF and MI had an increased risk of AD (HF: HR 1.11, 95% CI 1.04-1.19; MI: HR 1.10, 95% CI 1.02-1.18). AF was associated with VD (HR 1.58, 95% CI 1.42-1.77), but not with AD (HR 1.03, 95% CI 0.97-1.09). Clinical characteristics, such as diabetes, smoking and alcohol abuse, were associated with both types of dementia.

CONCLUSION

All major CVDs were associated with an increased risk of developing dementia, particularly VD. Therefore, CVD onset should prompt an assessment of cognitive decline and possible preventive measures.

Effect of overweight/obesity and metabolic syndrome on frailty in middle-aged and older Japanese adults

Background

The potential for developing frailty exists in middle-aged and older adults. While obesity and metabolic syndrome (MetS) increase the risk of frailty in older adults, this relationship remains unclear in middle-aged adults, who are prone to developing lifestyle-related diseases.

Objective

To examine the effect of overweight/obesity and MetS on frailty development in middle-aged and older Japanese adults using real-world data.

Methods

This nationwide cohort study used exhaustive health insurance claims data of 3,958,708 Japanese people from 2015 to 2019 provided by the Japan Health Insurance Association. Participants aged ≥35 and < 70 years who received health checkups in 2015 were included. Multivariate logistic regression was used to assess the effect of body mass index (BMI) and MetS or MetS components (i.e., diabetes, hypertension, and dyslipidemia) in 2015 on frailty risk assessed using the hospital frailty risk score in 2019. Additionally, a subgroup analysis was performed to examine the interaction effects of MetS components and 4-year weight change (%) on frailty risk among participants who were overweight and obese (BMI ≥25 kg/m2).

Results

In 2019, 7204 (0.2%) and 253,671 (6.4%) participants were at high and intermediate frailty risks, respectively. Obesity and MetS were independently associated with intermediate/high frailty risk (odds ratio (OR) 1.36, p < 0.05; OR 1.23, p < 0.05, respectively) and high frailty risk (OR 1.80, p < 0.05; OR 1.37, p < 0.05, respectively) in all participants. Although all MetS components were frailty risk factors, these effects diminished with age in both sexes. Subgroup analysis of patients with diabetes revealed that 5%-10% weight loss was associated with reduced frailty risk in both sexes.

Conclusions

Obesity, MetS, and MetS components were independent frailty risk factors in middle-aged and older Japanese adults. Weight loss of up to 10% over 4 years prevented frailty in patients with diabetes who were overweight and obese.

Navigating the dementia landscape: Biomarkers and emerging therapies

The field of dementia research has witnessed significant developments in our understanding of neurodegenerative disorders, with a particular focus on Alzheimer's disease (AD) and Frontotemporal Dementia (FTD). Dementia, a collection of symptoms arising from the degeneration of brain cells, presents a significant healthcare challenge, especially as its prevalence escalates with age. This abstract delves into the complexities of these disorders, the role of biomarkers in their diagnosis and monitoring, as well as emerging neurophysiological insights. In the context of AD, anti-amyloid therapy has gained prominence, aiming to reduce the accumulation of amyloid-beta (Aβ) plaques in the brain, a hallmark of the disease. Notably, Leqembi recently received full FDA approval, marking a significant breakthrough in AD treatment. Additionally, ongoing phase 3 clinical trials are investigating novel therapies, including Masitinib and NE3107, focusing on cognitive and functional improvements in AD patients. In the realm of FTD, research has unveiled distinct neuropathological features, including the involvement of proteins like TDP-43 and progranulin, providing valuable insights into the diagnosis and management of this heterogeneous condition. Biomarkers, including neurofilaments and various tau fragments, have shown promise in enhancing diagnostic accuracy. Neurophysiological techniques, such as transcranial magnetic stimulation (TMS), have contributed to our understanding of AD and FTD. TMS has uncovered unique neurophysiological signatures, highlighting impaired plasticity, hyperexcitability, and altered connectivity in AD, while FTD displays differences in neurotransmitter systems, particularly GABAergic and glutamatergic circuits. Lastly, ongoing clinical trials in anti-amyloid therapy for AD, such as Simufilam, Solanezumab, Gantenerumab, and Remternetug, offer hope for individuals affected by this devastating disease, with the potential to alter the course of cognitive decline. These advancements collectively illuminate the evolving landscape of dementia research and the pursuit of effective treatments for these challenging conditions.

Alterations of White Matter Connectivity in Adults with Essential Hypertension

Purpose

To explore the topology of the white matter network in individuals with essential hypertension by graph theory.

Patients and Methods

T1-weighted image and diffusion tensor imaging (DTI) data from 43 patients diagnosed with essential hypertension (EHT) and 33 individuals with normotension (healthy controls, HCs) were incorporated in this cross-sectional study. Furthermore, structural networks were constructed by graph theory to calculate whole brain network characteristics and intracerebral node characteristics.

Results

Both EHT and HC groups displayed small-worldness in their structural networks. The area under the curve (AUC) of the small-worldness coefficient (σ) was higher in the EHT group compared to the HC group, whereas the AUC of assortativity was lower in the EHT group in contrast to the HC group. The nodal clustering coefficient (CP) and local efficiency (Eloc) of the EHT group decreased in the right dorsolateral superior frontal gyrus and the left medial superior frontal gyrus. These values increased in the left anterior cingulate and paracingulate gyrus. Furthermore, weight and body mass index (BMI) were positively correlated with σ.

Conclusion

The EHT group showed brain network separation and integration dysfunction. Weight and BMI were positively correlated with σ. The data acquired in this investigation implied that altered structural connectivity in the prefrontal region may be a potential neuroimaging marker in EHT patients.

Current perspectives on prevention of vascular cognitive impairment and promotion of vascular brain health

INTRODUCTION

The true global burden of vascular cognitive impairment (VCI) is unknown. Reducing risk factors for stroke and cardiovascular disease would inevitably curtail VCI.

AREAS COVERED

The authors review current diagnosis, epidemiology, and risk factors for VCI. VCI increases in older age and by inheritance of known genetic traits. They emphasize modifiable risk factors identified by the 2020 Lancet Dementia Commission. The most profound risks for VCI also include lower education, cardiometabolic factors, and compromised cognitive reserve. Finally, they discuss pharmacological and non-pharmacological interventions.

EXPERT OPINION

By virtue of the high frequencies of stroke and cardiovascular disease the global prevalence of VCI is expectedly higher than prevalent neurodegenerative disorders causing dementia. Since ~ 90% of the global burden of stroke can be attributed to modifiable risk factors, a formidable opportunity arises to reduce the burden of not only stroke but VCI outcomes including progression from mild to the major in form of vascular dementia. Strict control of vascular risk factors and secondary prevention of cerebrovascular disease via pharmacological interventions will impact on burden of VCI. Non-pharmacological measures by adopting healthy diets and encouraging physical and cognitive activities and urging multidomain approaches are important for prevention of VCI and preservation of vascular brain health.

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

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

Sex differences in the age-related decrease of spontaneous baroreflex function in healthy individuals

The baroreflex is a powerful physiological mechanism for rapidly adjusting heart rate in response to changes in blood pressure. Spontaneous baroreflex sensitivity (BRS) has been shown to decrease with age. However, studies of sex differences in these age-related changes are rare. Here we investigated several markers of spontaneous baroreflex function in a large sample of healthy individuals. Cardiovascular signals were recorded in the supine position under carefully controlled resting conditions. After quality control, n = 980 subjects were divided into five age groups [age < 30 yr (n = 612), 30-39 yr (n = 140), 40-49 yr (n = 95), 50-59 yr (n = 61), and >60 yr (n = 72)]. Spontaneous baroreflex function was assessed in the time domain (bradycardic and tachycardic slope) and in the frequency domain in the low- and high-frequency band (LF-α, HF-α) applying the transfer function. General linear models showed a significant effect of factor age (P < 0.001) and an age × sex interaction effect (P < 0.05) on each indicator of the baroreflex function. Simple main effects showed a significantly higher BRS as indicated by tachycardic slope, LF-α and HF-α in middle-aged women compared with men (30-39 yr) and higher LF-α, bradycardic and tachycardic slope in men compared with women of the oldest age group (>60 yr). Changes in BRS over the lifespan suggest that baroreflex function declines more slowly but earlier in life in men than in women. Our findings could be linked to age-related changes in major sex hormone levels, suggesting significant implications for diverse cardiovascular outcomes and the implementation of targeted preventive strategies.NEW & NOTEWORTHY In this study, we demonstrate that the age-related decrease of spontaneous baroreflex sensitivity is different in men and women by analyzing resting state cardiovascular data of a large sample of healthy individuals.

Hypertension and Mild Cognitive Impairment: Understanding the Complexities of the Relationship in Understudied Populations

The association between hypertension and mild cognitive impairment (MCI) is complex. Both are increasing in prevalence worldwide and will have disproportionate effects on lower income countries across Latin America. Despite this, there is insufficient evidence investigating this relationship in this region or those of Hispanic or Latino ancestry in higher income countries. In this context, the Study of Latinos-Investigation of Neurocognitive Aging represents a unique dataset. Although more research is required, Márquez and colleagues show that hypertension in this population in the United States is associated with decline in cognitive measures and greater odds of MCI over seven years follow-up.

Association of cardiovascular disease management drugs with Lewy body dementia: a case-control study

Lewy body dementia is the second most common neurodegenerative dementia after Alzheimer's disease. Disease-modifying therapies for this disabling neuropsychiatric condition are critically needed. To identify drugs associated with the risk of developing Lewy body dementia, we performed a population-based case-control study of 148 170 US Medicare participants diagnosed with Lewy body dementia between 1 January 2008 and 31 December 2014 and of 1 253 043 frequency-matched controls. We estimated odds ratios and 95% confidence intervals for the association of Lewy body dementia risk with 1017 prescription drugs overall and separately for the three major racial groups (Black, Hispanic and White Americans). We identified significantly reduced Lewy body dementia risk associated with drugs used to treat cardiovascular diseases (anti-hypertensives: odds ratio = 0.72, 95% confidence interval = 0.70-0.74, P-value = 0; cholesterol-lowering agents: odds ratio = 0.85, 95% confidence interval = 0.83-0.87, P-value = 0; anti-diabetics: odds ratio = 0.83, 95% confidence interval = 0.62-0.72, P-value = 0). Notably, anti-diabetic medications were associated with a larger risk reduction among Black Lewy body dementia patients compared with other racial groups (Black: odds ratio = 0.67, 95% confidence interval = 0.62-0.72, P-value = 0; Hispanic: odds ratio = 0.86, 95% = 0.80-0.92, P-value = 5.16 × 10-5; White: odds ratio = 0.85, 95% confidence interval = 0.82-0.88, P-value = 0). To independently confirm the epidemiological findings, we looked for evidence of genetic overlap between Lewy body dementia and cardiovascular traits using whole-genome sequence data generated for 2591 Lewy body dementia patients and 4027 controls. Bivariate mixed modelling identified shared genetic risk between Lewy body dementia and low-density lipoprotein cholesterol levels, Type 2 diabetes and hypertension. By combining epidemiological and genomic data, we demonstrated that drugs treating cardiovascular diseases are associated with reduced Lewy body dementia risk, and these associations varied across racial groups. Future randomized clinical trials need to confirm our findings, but our data suggest that assiduous management of cardiovascular diseases may be beneficial in this understudied form of dementia.

Natural language processing to identify social determinants of health in Alzheimer's disease and related dementia from electronic health records

OBJECTIVE

To develop a natural language processing (NLP) algorithm that identifies social determinants of health (SDoH), including housing, transportation, food, and medication insecurities, social isolation, abuse, neglect, or exploitation, and financial difficulties for patients with Alzheimer's disease and related dementias (ADRD) from unstructured electronic health records (EHRs).

DATA SOURCES AND STUDY SETTING

We leveraged 1000 medical notes randomly selected from 7401 emergency department and inpatient social worker notes generated between 2015 and 2019 for 231 unique patients diagnosed with ADRD at Michigan Medicine.

STUDY DESIGN

We developed a rule-based NLP algorithm for the identification of seven domains of SDoH noted above. We also compared the rule-based algorithm with deep learning and regularized logistic regression approaches. These models were compared using accuracy, sensitivity, specificity, F1 score, and the area under the receiver operating characteristic curve (AUC). All notes were split into 700 notes for training NLP algorithms, and 300 notes for validation.

DATA COLLECTION/EXTRACTION METHODS

Social worker notes used in this study were extracted from the Michigan Medicine EHR database.

PRINCIPAL FINDINGS

Of the 700 notes for training, F1 and AUC for the rule-based algorithm were at least 0.94 and 0.95, respectively, for all SDoH categories. Of the 300 notes for validation, F1 and AUC were at least 0.80 and 0.97, respectively, for all SDoH except housing and medication insecurities. The deep learning and regularized logistic regression algorithms had unsatisfactory performance.

CONCLUSIONS

The rule-based algorithm can accurately extract SDoH information in all seven domains of SDoH except housing and medication insecurities. Findings from the algorithm can be used by clinicians and social workers to proactively address social needs of patients with ADRD and other vulnerable patient populations.

Association of medication adherence quality measures for diabetes, hypertension, and hyperlipidemia with cognitive decline

Background

While diabetes, hypertension, and hyperlipidemia each are associated with increased risk of cognitive decline, little is known regarding how nonadherence to medications for these conditions is associated with cognitive decline risk.

Methods

We identified patients enrolled in a Medicare Advantage Prescription Drug plan who were eligible for inclusion in the CMS Star Medication Adherence quality measures for diabetes, hypertension, and hyperlipidemia in 2018, 2019, and 2020. To achieve an adherence quality measure, patients had to meet 80% of the proportion of days for the medication. We used propensity score with inverse probability of treatment weighting to balance outcomes for baseline characteristics and logistic regression models to compare odds of cognitive decline outcomes across patient groups.

Results

The study population of 99,774 individuals had a mean age of 71.0 years and was 49.1% female, 73.9% White, and 17.8% Black, with 62.0% living in an urban setting. Compared with patients who missed zero adherence measures, those who missed one measure had 23%-33% increased odds of cognitive decline (any decline OR = 1.23; dementia OR = 1.33; Alzheimer's disease OR = 1.27; all P values <0.01). Patients who missed 2-3 measures had 37%-96% increased odds of cognitive decline (any decline OR = 1.37; dementia OR = 1.58; Alzheimer's disease OR = 1.96; all P values <0.01). Patients who missed ≥4 adherence measures had the greatest odds of cognitive decline (any decline OR = 1.64; dementia OR = 2.05; Alzheimer's disease OR = 2.48; all P values <0.01).

Conclusion

Not achieving CMS Star Medication Adherence quality measures for diabetes, hypertension, and hyperlipidemia therapies was associated with increased risk of cognitive decline outcomes.

Mechanistic insights on age-related changes in heart-aorta-brain hemodynamic coupling using a pulse wave model of the entire circulatory system

Age-related changes in aortic biomechanics can impact the brain by reducing blood flow and increasing pulsatile energy transmission. Clinical studies have shown that impaired cardiac function in patients with heart failure is associated with cognitive impairment. Although previous studies have attempted to elucidate the complex relationship between age-associated aortic stiffening and pulsatility transmission to the cerebral network, they have not adequately addressed the effect of interactions between aortic stiffness and left ventricle (LV) contractility (neither on energy transmission nor on brain perfusion). In this study, we use a well-established and validated one-dimensional blood flow and pulse wave computational model of the circulatory system to address how age-related changes in cardiac function and vasculature affect the underlying mechanisms involved in the LV-aorta-brain hemodynamic coupling. Our results reveal how LV contractility affects pulsatile energy transmission to the brain, even with preserved cardiac output. Our model demonstrates the existence of an optimal heart rate (near the normal human heart rate) that minimizes pulsatile energy transmission to the brain at different contractility levels. Our findings further suggest that the reduction in cerebral blood flow at low levels of LV contractility is more prominent in the setting of age-related aortic stiffening. Maintaining optimal blood flow to the brain requires either an increase in contractility or an increase in heart rate. The former consistently leads to higher pulsatile power transmission, and the latter can either increase or decrease subsequent pulsatile power transmission to the brain.NEW & NOTEWORTHY We investigated the impact of major aging mechanisms of the arterial system and cardiac function on brain hemodynamics. Our findings suggest that aging has a significant impact on heart-aorta-brain coupling through changes in both arterial stiffening and left ventricle (LV) contractility. Understanding the underlying physical mechanisms involved here can potentially be a key step for developing more effective therapeutic strategies that can mitigate the contributions of abnormal LV-arterial coupling toward neurodegenerative diseases and dementia.

Higher systolic blood pressure in early-mid adulthood is associated with poorer cognitive performance in those with a dominantly inherited Alzheimer's disease mutation but not in non-carriers. Results from the DIAN study

BACKGROUND

The Dominantly Inherited Alzheimer Network (DIAN) is a longitudinal observational study that collects data on cognition, blood pressure (BP), and other variables from autosomal-dominant Alzheimer's disease mutation carriers (MCs) and non-carrier (NC) family members in early to mid-adulthood, providing a unique opportunity to evaluate BP and cognition relationships in these populations.

METHOD

We examined cross-sectional and longitudinal relationships between systolic and diastolic BP and cognition in DIAN MC and NC.

RESULTS

Data were available from 528 participants, who had a mean age of 38 (SD = 11) and were 42% male and 61% MCs, at a median follow-up of 2 years. Linear-multilevel models found only cross-sectional associations in the MC group between higher systolic BP and poorer performance on language (β = -0.181 [-0.318, -0.044]), episodic memory (-0.212 [-0.375, -0.049]), and a composite cognitive measure (-0.146 [-0.276, -0.015]). In NCs, the relationship was cross-sectional only and present for language alone.

DISCUSSION

Higher systolic BP was cross-sectionally but not longitudinally associated with poorer cognition, particularly in MCs. BP may influence cognition gradually, but further longitudinal research is needed.

Recent research progress on metabolic syndrome and risk of Parkinson's disease

Parkinson's disease (PD) is one of the most widespread neurodegenerative diseases. PD is associated with progressive loss of substantia nigra dopaminergic neurons, including various motor symptoms (e.g., bradykinesia, rigidity, and resting tremor), as well as non-motor symptoms (e.g., cognitive impairment, constipation, fatigue, sleep disturbance, and depression). PD involves multiple biological processes, including mitochondrial or lysosomal dysfunction, oxidative stress, insulin resistance, and neuroinflammation. Metabolic syndrome (MetS), a collection of numerous connected cerebral cardiovascular conditions, is a common and growing public health problem associated with many chronic diseases worldwide. MetS components include central/abdominal obesity, systemic hypertension, diabetes, and atherogenic dyslipidemia. MetS and PD share multiple pathophysiological processes, including insulin resistance, oxidative stress, and chronic inflammation. In recent years, MetS has been linked to an increased risk of PD, according to studies; however, the specific mechanism remains unclear. Researchers also found that some related metabolic therapies are potential therapeutic strategies to prevent and improve PD. This article reviews the epidemiological relationship between components of MetS and the risk of PD and discusses the potentially relevant mechanisms and recent progress of MetS as a risk factor for PD. Furthermore, we conclude that MetS-related therapies are beneficial for the prevention and treatment of PD.

The Activities of the Slovenian Strategic Council for Nutrition 2023/24 to Improve the Health of the Slovenian Population and the Sustainability of Food: A Narrative Review

The health status of individuals in Slovenia across age groups is a matter of concern, as current unsustainable lifestyle choices are already leading to various chronic noncommunicable diseases (NCDs). Outdated national dietary guidelines, their inconsistent implementation, and a lack of structural changes represent obstacles to promoting healthy and sustainable nutrition. Limited access to and rising prices of healthy, sustainable foods, in addition to the high availability of low-priced, highly processed foods, increase the risk of NCDs. The lack of systematic health monitoring and early disease detection poses a challenge. Global and local environmental issues, resistance, and/or the inability to adopt healthier diets hinder individuals from changing their nutritional behaviours. In this narrative review, we provide an overview of the current situation in Slovenia as well as planned activities initiated by the Slovenian government and the Prime Minister's Strategic Council for Nutrition, aiming to make progress in supporting healthy and sustainable nutrition, limiting food waste, and increasing the availability of healthier foods for all. Improving the sustainability of the Slovenian food system can contribute to several Sustainable Development Goals (SDGs), ensuring Slovenia's commitment to internationally agreed-upon targets. This could lead Slovenia to take a role as a pilot country in testing and implementing the necessary systemic changes, which could be further applied in other countries.

Longitudinal associations of cardiovascular health and vascular events with incident dementia

INTRODUCTION

Evidence supporting cardiovascular diseases could increase the risk of dementia remains fragmented. A comprehensive study to illuminate the distinctive associations across different dementia types is still lacking. This study is sought to: (1) determine the clinical validity of Framingham General Cardiovascular Risk Score (FGCRS) for dementia assessment and (2) examine the associations between cardiovascular diseases and the risk of dementia.

METHODS

A total of 432 079 dementia-free individuals at baseline from UK Biobank were included. Multivariable Cox proportional hazard models were used to investigate the prospective associations for FGCRS and a series of cardiovascular diseases with all-cause dementia (ACD) and its major components, Alzheimer's disease (AD) and vascular dementia (VaD).

RESULTS

During a median follow-up of 110.1 months, 4711 individuals were diagnosed with dementia. FGCRS was associated with increased risks across the dementia spectrum. In stratification analysis, high-risk groups have demonstrated the greatest dementia burdens, particularly to VaD. Over 74 traits, 9 adverse associations, such as chronic ischaemic heart disease (ACD: HR=1.354; AD: HR=1.269; VaD: HR=1.768), atrioventricular block (ACD: HR=1.562; AD: HR=1.556; VaD: HR=2.069), heart failure (ACD: HR=1.639; AD: HR=1.543; VaD: HR=2.141) and hypotension (ACD: HR=2.912; AD: HR=2.361; VaD: HR=3.315) were observed. Several distinctions were also found, with atrial fibrillation, cerebral infarction, and haemorrhage only associated with greater risks of ACD and VaD.

DISCUSSION

By identifying distinctive associations between cardiovascular diseases and dementia, this study has established a comprehensive 'mapping' that may untangle the long-standing discrepancy. FGCRS has demonstrated its predictivity beyond cardiovascular diseases burdens, suggesting potential opportunities for implantation.

Year-by-Year Blood Pressure Variability From Midlife to Death and Lifetime Dementia Risk

Importance

High visit-to-visit blood pressure variability (BPV) in late life may reflect increased dementia risk better than mean systolic blood pressure (SBP). Evidence from midlife to late life could be crucial to understanding this association.

Objective

To determine whether visit-to-visit BPV at different ages was differentially associated with lifetime incident dementia risk in community-dwelling individuals.

Design, Setting, and Participants

This cohort study analyzed data from the Adult Changes in Thought (ACT) study, an ongoing population-based prospective cohort study in the US. Participants were 65 years or older at enrollment, community-dwelling, and without dementia. The study focused on a subset of deceased participants with brain autopsy data and whose midlife to late-life blood pressure data were obtained from Kaiser Permanente Washington medical archives and collected as part of the postmortem brain donation program. In the ACT study, participants underwent biennial medical assessments, including cognitive screening. Data were collected from 1994 (ACT study enrollment) through November 2019 (data set freeze). Data analysis was performed between March 2020 and September 2023.

Exposures

Visit-by-visit BPV at ages 60, 70, 80, and 90 years, calculated using the coefficient of variation of year-by-year SBP measurements over the preceding 10 years.

Main Outcomes and Measures

All-cause dementia, which was adjudicated by a multidisciplinary outcome adjudication committee.

Results

A total of 820 participants (mean [SD] age at enrollment, 77.0 [6.7] years) were analyzed and included 476 females (58.0%). A mean (SD) of 28.4 (8.4) yearly SBP measurements were available over 31.5 (9.0) years. The mean (SD) follow-up time was 32.2 (9.1) years in 27 885 person-years from midlife to death. Of the participants, 372 (45.4%) developed dementia. The number of participants who were alive without dementia and had available data for analysis ranged from 280 of those aged 90 years to 702 of those aged 70 years. Higher BPV was not associated with higher lifetime dementia risk at age 60, 70, or 80 years. At age 90 years, BPV was associated with 35% higher dementia risk (hazard ratio [HR], 1.35; 95% CI, 1.02-1.79). Meta-regression of HRs calculated separately for each age (60-90 years) indicated that associations of high BPV with higher dementia risk were present only at older ages, whereas the association of SBP with dementia gradually shifted direction linearly from being incrementally to inversely associated with older ages.

Conclusions and Relevance

In this cohort study, high BPV indicated increased lifetime dementia risk in late life but not in midlife. This result suggests that high BPV may indicate increased dementia risk in older age but might be less viable as a midlife dementia prevention target.

Blood pressure-related white matter microstructural disintegrity and associated cognitive function impairment in asymptomatic adults

BACKGROUND AND OBJECTIVES

We aimed to investigate the white matter (WM) microstructural/cytostructural disintegrity patterns related to higher systolic blood pressure (SBP), and whether they mediate SBP effects on cognitive performance in middle-aged adults.

METHODS

Using the UK Biobank study of community-dwelling volunteers aged 40-69 years, we included participants without a history of stroke, dementia, demyelinating disease or traumatic brain injury. We investigated the association of SBP with MRI diffusion metrics: fractional anisotropy (FA), mean diffusivity (MD), intracellular volume fraction (a measure of neurite density), isotropic (free) water volume fraction (ISOVF) and orientation dispersion across WM tracts. Then, we determined whether WM diffusion metrics mediated the effects of SBP on cognitive function.

RESULTS

We analysed 31 363 participants-mean age of 63.8 years (SD: 7.7), and 16 523 (53%) females. Higher SBP was associated with lower FA and neurite density, but higher MD and ISOVF. Among different WM tracts, diffusion metrics of the internal capsule anterior limb, external capsule, superior and posterior corona radiata were most affected by higher SBP. Among seven cognitive metrics, SBP levels were only associated with 'fluid intelligence' (adjusted p<0.001). In mediation analysis, the averaged FA of external capsule, internal capsule anterior limb and superior cerebellar peduncle mediated 13%, 9% and 13% of SBP effects on fluid intelligence, while the averaged MD of external capsule, internal capsule anterior and posterior limbs, and superior corona radiata mediated 5%, 7%, 7% and 6% of SBP effects on fluid intelligence, respectively.

DISCUSSION

Among asymptomatic adults, higher SBP is associated with pervasive WM microstructure disintegrity, partially due to reduced neuronal count, which appears to mediate SBP adverse effects on fluid intelligence. Diffusion metrics of select WM tracts, which are most reflective of SBP-related parenchymal damage and cognitive impairment, may serve as imaging biomarkers to assess treatment response in antihypertensive trials.

Antihypertensives in dementia: Good or bad for the brain?

Hypertension is associated with both ageing and dementia. Despite this, optimal blood pressure targets in dementia remain unclear. Both high and low blood pressure are associated with poorer cognition. Changes in vascular physiology in dementia may increase the vulnerability of the brain to hypoperfusion associated with antihypertensives. We discuss the potential risks of antihypertensives in the context of altered cerebral haemodynamics, and evidence from antihypertensive trials in dementia. We suggest that individualised blood pressure targets should be the focus for antihypertensive therapy in dementia, rather than strict control to uniform targets extrapolated from trials in cognitively healthy individuals.

Blood Pressure, Incident Cognitive Impairment, and Severity of CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

RATIONALE & OBJECTIVE

Hypertension is a known risk factor for dementia and cognitive impairment. There are limited data on the relation of systolic blood pressure (SBP) and diastolic blood pressure (DBP) with incident cognitive impairment in adults with chronic kidney disease. We sought to identify and characterize the relationship among blood pressure, cognitive impairment, and severity of decreased kidney function in adults with chronic kidney disease.

STUDY DESIGN

Longitudinal cohort study.

SETTING & PARTICIPANTS

3,768 participants in the Chronic Renal Insufficiency Cohort (CRIC) Study.

EXPOSURE

Baseline SBP and DBP were examined as exposure variables, using continuous (linear, per 10-mm Hg higher), categorical (SBP<120 [reference], 120 to 140,>140mm Hg; DBP<70 (reference), 70 to 80, > 80mm Hg) and nonlinear terms (splines).

OUTCOME

Incident cognitive impairment defined as a decline in Modified Mini-Mental State Examination (3MS) score to greater than 1 standard deviation below the cohort mean.

ANALYTICAL APPROACH

Cox proportional hazard models adjusted for demographics as well as kidney disease and cardiovascular disease risk factors.

RESULTS

The mean age of participants was 58±11 (SD) years, estimated glomerular filtration rate (eGFR) was 44mL/min/1.73m2 ± 15 (SD), and the median follow-up time was 11 (IQR, 7-13) years. In 3,048 participants without cognitive impairment at baseline and with at least 1 follow-up 3MS test, a higher baseline SBP was significantly associated with incident cognitive impairment only in the eGFR>45mL/min/1.73m2 subgroup (adjusted hazard ratio [AHR], 1.13 [95% CI, 1.05-1.22] per 10mm Hg higher SBP]. Spline analyses, aimed at exploring nonlinearity, showed that the relationship between baseline SBP and incident cognitive impairment was J-shaped and significant only in the eGFR>45mL/min/1.73m2 subgroup (P=0.02). Baseline DBP was not associated with incident cognitive impairment in any analyses.

LIMITATIONS

3MS test as the primary measure of cognitive function.

CONCLUSIONS

Among patients with chronic kidney disease, higher baseline SBP was associated with higher risk of incident cognitive impairment specifically in those individuals with eGFR>45mL/min/1.73m2.

PLAIN-LANGUAGE SUMMARY

High blood pressure is a strong risk factor for dementia and cognitive impairment in studies of adults without kidney disease. High blood pressure and cognitive impairment are common in adults with chronic kidney disease (CKD). The impact of blood pressure on the development of future cognitive impairment in patients with CKD remains unclear. We identified the relationship between blood pressure and cognitive impairment in 3,076 adults with CKD. Baseline blood pressure was measured, after which serial cognitive testing was performed over 11 years. Fourteen percent of participants developed cognitive impairment. We found that a higher baseline systolic blood pressure was associated with an increased risk of cognitive impairment. We found that this association was stronger in adults with mild-to-moderate CKD compared with those with advanced CKD.

L-Arginine-eNOS-NO Functional System in Brain Damage and Cognitive Impairments in Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) is a significant cause of cognitive impairment (CI), disability, and mortality. The insufficient effectiveness of antihypertensive therapy in curbing the disease justifies the search for potential targets for modifying therapy and indicators supporting its use. Using a laser-assisted optical rotational cell analyzer (LORRCA, Mechatronics, The Netherlands), the rheological properties and deformability of erythrocytes before and after incubation with 10 μmol/L of L-arginine, the nitric oxide (NO) donor, blood-brain barrier (BBB) permeability assessed by dynamic contrast-enhanced MRI, clinical, and MRI signs were studied in 73 patients with CSVD (48 women, mean age 60.1 ± 6.5 years). The control group consisted of 19 volunteers (14 women (73.7%), mean age 56.9 ± 6.4 years). The erythrocyte disaggregation rate (y-dis) after incubation with L-arginine showed better performance than other rheological characteristics in differentiating patients with reduced NO bioavailability/NO deficiency by its threshold values. Patients with y-dis > 113 s-1 had more severe CI, arterial hypertension, white matter lesions, and increased BBB permeability in grey matter and normal-appearing white matter (NAWM). A test to assess changes in the erythrocyte disaggregation rate after incubation with L-arginine can be used to identify patients with impaired NO bioavailability. L-arginine may be part of a therapeutic strategy for CSVD with CI.

Vegetarian and vegan diets: benefits and drawbacks

Plant-based diets have become increasingly popular thanks to their purported health benefits and more recently for their positive environmental impact. Prospective studies suggest that consuming vegetarian diets is associated with a reduced risk of developing cardiovascular disease (CVD), diabetes, hypertension, dementia, and cancer. Data from randomized clinical trials have confirmed a protective effect of vegetarian diets for the prevention of diabetes and reductions in weight, blood pressure, glycosylated haemoglobin and low-density lipoprotein cholesterol, but to date, no data are available for cardiovascular event rates and cognitive impairment, and there are very limited data for cancer. Moreover, not all plant-based foods are equally healthy. Unhealthy vegetarian diets poor in specific nutrients (vitamin B12, iron, zinc, and calcium) and/or rich in highly processed and refined foods increase morbidity and mortality. Further mechanistic studies are desirable to understand whether the advantages of healthy, minimally processed vegetarian diets represent an all-or-nothing phenomenon and whether consuming primarily plant-based diets containing small quantities of animal products (e.g. pesco-vegetarian or Mediterranean diets) has beneficial, detrimental, or neutral effects on cardiometabolic health outcomes. Further, mechanistic studies are warranted to enhance our understanding about healthy plant-based food patterns and the biological mechanisms linking dietary factors, CVD, and other metabolic diseases.

Use of Antihypertensives, Blood Pressure, and Estimated Risk of Dementia in Late Life: An Individual Participant Data Meta-Analysis

Importance

The utility of antihypertensives and ideal blood pressure (BP) for dementia prevention in late life remains unclear and highly contested.

Objectives

To assess the associations of hypertension history, antihypertensive use, and baseline measured BP in late life (age >60 years) with dementia and the moderating factors of age, sex, and racial group.

Data Source and Study Selection

Longitudinal, population-based studies of aging participating in the Cohort Studies of Memory in an International Consortium (COSMIC) group were included. Participants were individuals without dementia at baseline aged 60 to 110 years and were based in 15 different countries (US, Brazil, Australia, China, Korea, Singapore, Central African Republic, Republic of Congo, Nigeria, Germany, Spain, Italy, France, Sweden, and Greece).

Data Extraction and Synthesis

Participants were grouped in 3 categories based on previous diagnosis of hypertension and baseline antihypertensive use: healthy controls, treated hypertension, and untreated hypertension. Baseline systolic BP (SBP) and diastolic BP (DBP) were treated as continuous variables. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-Analyses of Individual Participant Data reporting guidelines.

Main Outcomes and Measures

The key outcome was all-cause dementia. Mixed-effects Cox proportional hazards models were used to assess the associations between the exposures and the key outcome variable. The association between dementia and baseline BP was modeled using nonlinear natural splines. The main analysis was a partially adjusted Cox proportional hazards model controlling for age, age squared, sex, education, racial group, and a random effect for study. Sensitivity analyses included a fully adjusted analysis, a restricted analysis of those individuals with more than 5 years of follow-up data, and models examining the moderating factors of age, sex, and racial group.

Results

The analysis included 17 studies with 34 519 community dwelling older adults (20 160 [58.4%] female) with a mean (SD) age of 72.5 (7.5) years and a mean (SD) follow-up of 4.3 (4.3) years. In the main, partially adjusted analysis including 14 studies, individuals with untreated hypertension had a 42% increased risk of dementia compared with healthy controls (hazard ratio [HR], 1.42; 95% CI 1.15-1.76; P = .001) and 26% increased risk compared with individuals with treated hypertension (HR, 1.26; 95% CI, 1.03-1.53; P = .02). Individuals with treated hypertension had no significant increased dementia risk compared with healthy controls (HR, 1.13; 95% CI, 0.99-1.28; P = .07). The association of antihypertensive use or hypertension status with dementia did not vary with baseline BP. There was no significant association of baseline SBP or DBP with dementia risk in any of the analyses. There were no significant interactions with age, sex, or racial group for any of the analyses.

Conclusions and Relevance

This individual patient data meta-analysis of longitudinal cohort studies found that antihypertensive use was associated with decreased dementia risk compared with individuals with untreated hypertension through all ages in late life. Individuals with treated hypertension had no increased risk of dementia compared with healthy controls.

Effects of intensive blood pressure control on cognitive function in patients with cerebral small vessel disease

OBJECTIVE

This study aimed to investigate the effects of intensive blood pressure control on cognitive function in elderly patients with cerebral small vessel disease (CSVD).

METHODS

From May 2020 to June 2022, 140 outpatients and inpatients with CSVD and hypertension in the Department of Neurology of Beijing Shijingshan Hospital were selected. They were randomly divided into the standard and intensive blood pressure control groups, and the dosage of antihypertensive drugs was adjusted to reduce the blood pressure to the target level. The patients were followed up for 2 years. The medical records or data at "enrollment" and "2-year follow-up" were analyzed and evaluated. The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were used to evaluate cognitive function. Cranial magnetic resonance imaging was performed to evaluate lacunar infarctions (LIs) and white matter hyperintensity (WMH). Multiple linear regression was used to analyze the correlation between MMSE scores and blood pressure, WMH, and LIs.

RESULTS

(1) The MMSE and MoCA scores in the standard group were significantly lower than those at enrollment. The WMH score in the standard group was significantly higher than that at enrollment. (2) After the 2-year follow-up, the 24-h systolic blood pressure (SBP), 24-h diastolic blood pressure (DBP), daytime mean SBP, daytime mean DBP, and nighttime mean SBP in the two groups significantly decreased, which had significant statistical significance (P < 0.05). (3) The correlation between blood pressure and MMSE score was analyzed using multiple linear regression analysis. The WMH score, LIs, 24-h SBP, and 24-h DBP were independently correlated with MMSE scores.

CONCLUSION

In elderly patients with hypertension, a decrease in SBP to 126 mmHg, compared with 134 mmHg, can delay cognitive impairment as well as reduce LIs and cerebral WMH lesions in patients with CSVD.