Visit-to-visit variability in blood pressure and Alzheimer's disease

Gray matter volume mediates the association of long-term blood pressure variability with cognitive function in an adult population

INTRODUCTION

We delineated the associations among long-term blood pressure variability (BPV), brain structure, and cognitive function.

METHODS

We included 1254 adult participants from the Kailuan study. BPV was calculated from 2006 to 2020. Brain magnetic resonance imaging (MRI) and Montreal Cognitive Assessment (MoCA) were conducted in 2020.

RESULTS

Higher systolic BPV (SBPV) and diastolic BPV (DBPV) were associated with lower total and frontal gray matter (GM) volume, and higher SBPV was associated with lower temporal GM volume. Elevated DBPV was associated with lower volume of total brain and parietal GM, and higher white matter hyperintensity (WMH) volume. Higher SBPV and DBPV were associated with lower MoCA scores. Decreased total and regional GM volume and increased WMH volume were associated with lower MoCA scores. The association between SBPV and cognitive function was mediated by total, frontal, and temporal GM volume.

DISCUSSION

GM volume may play key roles in the association between SBPV and cognitive function.

HIGHLIGHTS

SBPV and DBPV were negatively associated with total and regional brain volume. SBPV and DBPV were negatively associated with cognitive function. Decreased brain volume was associated with cognitive decline. GM volume mediated the negative association between SBPV and cognitive function.

High pulse wave velocity is associated with enlarged perivascular spaces in dementia with Lewy bodies

Previous studies have demonstrated associations between enlarged perivascular spaces (EPVS) and dementias such as Alzheimer's disease. However, an association between EPVS and dementia with Lewy bodies (DLB) has not yet been clarified. We performed a cross-sectional analysis of our prospective study cohort of 109 participants (16 with DLB). We assessed cognitive function, pulse wave velocity (PWV), and brain magnetic resonance imaging features. The relationships between EPVS and DLB were evaluated using multivariable logistic regression analyses. Compared with the non-dementia group, the DLB group was more likely to have EPVS in the basal ganglia. Compared with participants without EPVS, those with EPVS were older and had cognitive impairment and high PWV. In multivariable analyses, EPVS in the basal ganglia was independently associated with DLB. High PWV was also independently associated with EPVS in both the basal ganglia and centrum semiovale. High PWV may cause cerebrovascular pulsatility, leading to accelerated EPVS in DLB participants.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Blood pressure variability, central autonomic network dysfunction and cerebral small vessel disease in APOE4 carriers

Background

Increased blood pressure variability (BPV) is a risk factor for cerebral small vessel disease (CSVD) and neurodegeneration, independent of age and average blood pressure, particularly in apolipoprotein E4 (APOE4) carriers. However, it remains uncertain whether BPV elevation is a cause or a consequence of vascular brain injury, or to what degree injury to the central autonomic network (CAN) may contribute to BPV-associated risk in APOE4 carriers.

Methods

Independently living older adults (n=70) with no history of stroke or dementia were recruited from the community and underwent 5 minutes of resting beat-to-beat blood pressure monitoring, genetic testing, and brain MRI. Resting BPV, APOE genotype, CSVD burden on brain MRI, and resting state CAN connectivity by fMRI were analyzed. Causal mediation and moderation analysis evaluated BPV and CAN effects on CSVD in APOE4 carriers (n=37) and non-carriers (n=33).

Results

Higher BPV was associated with the presence and extent of CSVD in APOE4 carriers, but not non-carriers, independent of CAN connectivity (B= 18.92, P= .02), and CAN connectivity did not mediate the relationship between BPV and CSVD. In APOE4 carriers, CAN connectivity moderated the relationship between BPV and CSVD, whereby BPV effects on CSVD were greater in those with lower CAN connectivity (B= 36.43, P= .02).

Conclusions

Older APOE4 carriers with higher beat-to-beat BPV exhibit more extensive CSVD, independent of average blood pressure, and the strength of CAN connectivity does not mediate these effects. Findings suggest increased BPV is more likely a cause, not a consequence, of CSVD. BPV is more strongly associated with CSVD in APOE4 carriers with lower rsCAN connectivity, suggesting CAN dysfunction and BPV elevation may have synergistic effects on CSVD. Further studies are warranted to understand the interplay between BPV and CAN function in APOE4 carriers.

Analysis of the relationship between blood pressure variability and subtle cognitive decline in older adults

BACKGROUND

Blood pressure variability (BPV) has been shown to be related to mild cognitive impairment and Alzheimer's disease in a number of studies. However, the relationship between BPV and subtle cognitive decline (SCD) has received minimal attention in this field of research to date and has rarely been reported.

AIM

To examine whether SCD is independently associated with changes in BPV in older adults.

METHODS

Participants were selected based on having participated in cognitive function evaluation and ambulatory blood pressure measurement at the Shanghai Sixth People's Hospital Affiliated with Shanghai Jiao Tong University School of Medicine between June 2020 and August 2022. The participants included 182 individuals with SCD as the experimental group and 237 with normal cognitive function as the control group. The basic data, laboratory examinations, scale tests, and ambulatory blood pressure test results of the two groups were analyzed retrospectively, and the relationship between SCD and BPV was subsequently evaluated.

RESULTS

Significant differences were observed between the two groups of participants (P < 0.05) in terms of age, education level, prevalence rate of diabetes, fasting blood glucose level, 24-h systolic blood pressure standard deviation and coefficient of variation, 24-h diastolic blood pressure standard deviation and coefficient of variation. The scale monitoring results showed significant differences in the scores for memory, attention, and visual space between the experimental and control groups. Logistic regression analysis indicated that age, education level, blood sugar level, and BPV were factors influencing cognitive decline. Linear regression analysis showed that there was an independent correlation between blood pressure variation and SCD, even after adjusting for related factors. Each of the above differences was still significant.

CONCLUSION

This study suggests that increased BPV is associated with SCD.

Risk factors and prevalence of cognitive impairment in maintenance haemodialysis patients: A systematic review and meta-analysis of observational studies

AIMS

To systematically identify the risk factors for cognitive impairment in maintenance haemodialysis patients and to assess its prevalence in included studies.

DESIGN

Systematic review and meta-analysis about observational studies.

DATA SOURCES

Systematic search of seven databases, including PubMed, Web of Science, Scope, Wanfang Database, China National Knowledge Infrastructure, Chinese Biomedical Literature Database and Weipu Chinese Science and Technology Journal Database, from inception until October 2021.

REVIEW METHODS

Observational studies reporting the risk factors for cognitive impairment in maintenance haemodialysis patients in English and Chinese language were included. Meta-analysis was performed to identify risk factors and prevalence of cognitive impairment in maintenance haemodialysis patients with STATA 15.0 software.

RESULTS

Overall, 37 eligible studies encompassing 129,849 cases were included. The risk factors with statistical significance after meta-analysis were older age, female sex, fewer years of education, hypertension, diabetes, cerebrovascular accident, multiple comorbid conditions, systolic blood pressure variability, arterial stiffness and low haemoglobin and albumin level. The overall prevalence of cognitive impairment in maintenance haemodialysis patients was 49.1%.

CONCLUSION

The current analysis indicated a high prevalence of cognitive impairment in maintenance haemodialysis patients. Eleven risk factors for cognitive impairment in maintenance haemodialysis patients were identified, among which more attention should be paid to modifiable factors such as cardiovascular disease risk factors and specific kidney and dialysis-related factors.

IMPACT

This paper provides an updated estimate of the pooled prevalence of cognitive impairment in maintenance haemodialysis patients. Identification of risk factors associated with cognitive impairment may assist in developing targeted prevention strategies for maintenance haemodialysis patients at high risk.

NO PATIENT OR PUBLIC CONTRIBUTION

This study was a systematic review completed by the authors in accordance with relevant guidelines and processes and did not include the participation of patients, service users, caregivers or the general public.

Cross-sectional associations between short and mid-term blood pressure variability, cognition, and vascular stiffness in older adults

Background

High blood pressure variability (BPV), particularly in older age, appears to be an independent risk factor for incident dementia. The current study aimed to investigate the association between different BPV measures (short- and mid-term BPV including circadian patterns) and cognitive functioning as well as vascular stiffness measures to better understand the role that BPV plays in cognitive impairment.

Methods

70 older adults (60-80-year-olds) without dementia completed a cognitive test battery and had their blood pressure (BP) assessed via a 24-hour ambulatory BP monitor (divided into sleep and wake for short-term BPV) and 4-day morning and evening home-based BP monitor (for day-to-day BPV). Arterial stiffness was evaluated via pulse wave analysis and pulse wave velocity (PWV) and cerebrovascular pulsatility was assessed via transcranial doppler sonography of the middle cerebral arteries.

Results

High systolic as well as diastolic short- and mid-term BPV were associated with poorer cognitive functioning, independent of the mean BP. Higher short-term BPV was associated with poorer attention and psychomotor speed, whilst day-to-day BPV was negatively linked with executive functioning. Circadian BP patterns (dipping and morning BP surge) showed no significant relationships with cognition after adjusting for covariates. Higher systolic short-term BPV was associated with higher arterial stiffness (PWV) and higher diastolic day-to-day BPV was linked with lower arterial stiffness. No significant associations between BPV measures and cerebrovascular pulsatility were present.

Conclusion

High BPV, independently of the mean BP, is associated with lower cognitive performance and increased arterial stiffness in older adults without clinically-relevant cognitive impairment. This highlights the role of systolic and diastolic BPV as a potential early clinical marker for cognitive impairment.

The relationship between long-term blood pressure variability and cortical thickness in older adults

High blood pressure variability (BPV) is a risk factor for cognitive decline and dementia, but its association with cortical thickness is not well understood. Here we use a topographical approach, to assess links between long-term BPV and cortical thickness in 478 (54% men at baseline) community dwelling older adults (70-88 years) from the ASPirin in Reducing Events in the Elderly NEURO sub-study. BPV was measured as average real variability, based on annual visits across three years. Higher diastolic BPV was significantly associated with reduced cortical thickness in multiple areas, including temporal (banks of the superior temporal sulcus), parietal (supramarginal gyrus, post-central gyrus), and posterior frontal areas (pre-central gyrus, caudal middle frontal gyrus), while controlling for mean BP. Higher diastolic BPV was associated with faster progression of cortical thinning across the three years. Diastolic BPV is an important predictor of cortical thickness, and trajectory of cortical thickness, independent of mean blood pressure. This finding suggests an important biological link in the relationship between BPV and cognitive decline in older age.

Toll-Like Receptor 4: A Promising Therapeutic Target for Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease that primarily manifests as memory deficits and cognitive impairment and has created health challenges for patients and society. In AD, amyloid β-protein (Aβ) induces Toll-like receptor 4 (TLR4) activation in microglia. Activation of TLR4 induces downstream signaling pathways and promotes the generation of proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β), which also trigger the activation of astrocytes and influence amyloid-dependent neuronal death. Therefore, TLR4 may be an important molecular target for treating AD by regulating neuroinflammation. Moreover, TLR4 regulates apoptosis, autophagy, and gut microbiota and is closely related to AD. This article reviews the role of TLR4 in the pathogenesis of AD and a range of potential therapies targeting TLR4 for AD. Elucidating the regulatory mechanism of TLR4 in AD may provide valuable clues for developing new therapeutic strategies for AD.

Blood pressure variability and structural brain changes: a systematic review

BACKGROUND

Blood pressure variability (BPV) has been linked with cognitive impairment and dementia. However, the pathophysiological mechanisms by which BPV affects cognition are unclear. This systematic review aims to assess the links between different BPV measures and white and grey matter structures.

METHODS AND RESULTS

The following databases were searched from inception through to January 2021; EMBASE, MEDLINE, EMCARE and SCOPUS. Studies that reported on the relationship between within-individual BPV (short, medium or long-term variability) or a circadian blood pressure (BP) measurement and MRI assessed brain structures were included. Overall, 20 studies met the criteria and were included, of which 11 studies looked at short-term BPV, eight articles investigated visit-to-visit BPV and one study looked at a compositional BPV measurement. Due to heterogeneity in study samples, meta-analysis was not possible. Across the included studies, associations between MRI indices and BP dipping patterns were mixed; higher long-term BPV and higher sleep systolic BPV was found to be associated with lower whole brain volume and hippocampal volume.

CONCLUSION

Increased BPV, in particular systolic long-term and systolic night-time BPV, appears to be associated with lower brain volume and hippocampal volume. This highlights the adverse effect that increased BPV has upon the brain, potentially contributing to cognitive decline, including dementia, in late-life.

Different hypertension thresholds and cognitive decline: a pooled analysis of three ageing cohorts

BACKGROUND

The 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for high blood pressure (BP) in adults came up with a new definition of hypertension with a threshold BP level of 130/80 mmHg. But the 2018 European Society of Cardiology (ESC)/European Society of Hypertension (ESH) guidelines adhered to a conventional hypertension definition as BP ≥ 140/90 mmHg. We aimed to compare the trajectories of cognitive decline between participants with BP < 130/80 mmHg in all BP measurement waves and others with all BP < 140/90 mmHg.

METHODS

This pooled analysis involved middle-aged and older participants from three nationally representative ageing cohorts, including the Health and Retirement Study (HRS), the English Longitudinal Study of Ageing (ELSA), and the China Health Retirement Longitudinal Study (CHARLS). Participants were divided into the Normal (BP < 130/80 mmHg on all occasions throughout the study), the Borderline (BP < 140/90 mmHg on all occasions throughout the study but not in the Normal group), and the High (the rest of participants) BP groups. Global cognitive Z score was calculated from tests on memory, executive function, and orientation.

RESULTS

A total of 17,590 participants (HRS 6964, median follow-ups 12 years; ELSA 5334, median follow-ups 16 years; CHARLS 5292, median follow-ups 7 years) were included. No significant difference in global cognitive decline rate was detected between the Normal and the borderline groups (men, pooled β = - 0.006 standard deviation [SD]/year; 95% confidence interval [CI], - 0.020 to 0.008; P = 0.377; women, pooled β = 0.006 SD/year; 95% CI - 0.005 to 0.018; P = 0.269). Participants in the High group had a significantly faster cognitive decline (men, pooled β = - 0.011 SD/year; 95% CI - 0.020 to - 0.002; P = 0.013; women, pooled β = - 0.017 SD/year; 95% CI - 0.026 to - 0.008; P < 0.001) than that in the Borderline group.

CONCLUSIONS

Individuals in the Borderline group did not experience significantly faster cognitive decline compared with those in the Normal group. It might not be necessary for individuals with borderline BP (between 130/80 and 140/90 mmHg) to initiate antihypertension therapy in consideration of cognitive decline.

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

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

Association between Blood Pressure, Blood Pressure Variability, and Post-Stroke Cognitive Impairment

After stroke, dynamic changes take place from necrotic-apoptotic continuum, inflammatory response to poststroke neurogenesis, and remodeling of the network. These changes and baseline brain pathology such as small vessel disease (SVD) and amyloid burden may be associated with the occurrence of early or late poststroke cognitive impairment (PSCI) or dementia (PSD), which affect not only stroke victims but also their families and even society. We reviewed the current concepts and understanding of the pathophysiology for PSCI/PSD and identified useful tools for the diagnosis and the prediction of PSCI in serological, CSF, and image characteristics. Then, we untangled their relationships with blood pressure (BP) and blood pressure variability (BPV), important but often overlooked risk factors for PSCI/PSD. Finally, we provided evidence for the modifying effects of BP and BPV on PSCI as well as pharmacological and non-pharmacological interventions and life style modification for PSCI/PSD prevention and treatment.

Long-Term Blood Pressure Variability and Risk of Cognitive Decline and Dementia Among Older Adults

Background

Blood pressure variability (BPV) in midlife increases risk of late‐life dementia, but the impact of BPV on the cognition of adults who have already reached older ages free of major cognitive deficits is unknown. We examined the risk of incident dementia and cognitive decline associated with long‐term, visit‐to‐visit BPV in a post hoc analysis of the ASPREE (Aspirin in Reducing Events in the Elderly) trial.

Methods and Results

ASPREE participants (N=19 114) were free of dementia and significant cognitive impairment at enrollment. Measurement of BP and administration of a standardized cognitive battery evaluating global cognition, delayed episodic memory, verbal fluency, and processing speed and attention occurred at baseline and follow‐up visits. Time‐to‐event analysis using Cox proportional hazards regression models were used to calculate hazard ratios (HR) and corresponding 95% CI for incident dementia and cognitive decline, according to tertile of SD of systolic BPV. Individuals in the highest BPV tertile compared with the lowest had an increased risk of incident dementia and cognitive decline, independent of average BP and use of antihypertensive drugs. There was evidence that sex modified the association with incident dementia (interaction P=0.02), with increased risk in men (HR, 1.68; 95% CI, 1.19–2.39) but not women (HR, 1.01; 95% CI, 0.72–1.42). For cognitive decline, similar increased risks were observed for men and women (interaction P=0.15; men: HR, 1.36; 95% CI, 1.16–1.59; women: HR, 1.14; 95% CI, 0.98–1.32).

Conclusions

High BPV in older adults without major cognitive impairment, particularly men, is associated with increased risks of dementia and cognitive decline.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01038583; isrctn.com. Identifier: ISRCTN83772183.

Tau pathologies mediate the association of blood pressure with cognitive impairment in adults without dementia: The CABLE study

INTRODUCTION

This study delineated the interrelationships among blood pressure (BP), cerebrospinal fluid (CSF) core biomarkers of Alzheimer's disease (AD), and cognition.

METHODS

The linear regression analyses were conducted in 1546 non-demented participants (mean age of 61.58 years, range 40 to 89 years; 40% female; average days of BP measurement, 9.10 days). Mediation analyses with 10,000 bootstrapped iterations were used to explore the mediation effects.

RESULTS

A clear age-related pattern of BP was delineated. Mid-life hypertension (especially systolic BP), late-life lower diastolic BP, as well as mid- and late-life higher pulse pressure were associated with cognitive impairment and tau-related biomarkers. BP variability was associated only with cognition but not with CSF biomarkers. Overall, the associations between BP and cognition were partially mediated (proportion: 11% to 30%) by tau pathologies, independently of amyloid pathology.

DISCUSSION

Tau pathologies might play important roles in the relationship between BP and cognition, with significant age- and BP-type dependences.

Haemodynamic impairment along the Alzheimer's disease continuum

BACKGROUND AND PURPOSE

Alzheimer's disease (AD) is considered a clinical and biological continuum identified via cerebrospinal fluid (CSF) or imaging biomarkers. Chronic hypoperfusion is held as one of the main features of Alzheimer's disease, as part of the processes causing neuronal degeneration. The mechanism responsible for such condition is still debated, although recently a direct connection with amyloid peptides has been shown. Here the aim was to investigate whether measures of hypoperfusion change along the AD continuum.

METHODS

Seventy patients with mild AD were recruited and stratified according to their CSF biomarker profile-as indicated by the National Institute on Aging and Alzheimer's Association research framework-into patients with either isolated amyloid pathology (A+T-) or full-blown AD (A+T+), and further layered according to apolipoprotein E genotype. After evaluation of vascular risk factors, a transcranial Doppler was performed on each patient, to evaluate mean flow velocity and pulsatility index in the middle cerebral artery, and to calculate the breath-holding index. Patients were compared to a cohort of 17 healthy controls.

RESULTS

The breath-holding index was reduced in the AD continuum and was inversely correlated to CSF amyloid β42 levels. Such correlation was stronger in the A+T+ than in the A+T- group, and unexpectedly reached statistical significance only in the E3 and not in the E4 genotype carriers.

CONCLUSIONS

These results suggest a tight and effective relationship between amyloid β42, vascular hypoperfusion, cerebrovascular reactivity and epsilon genotype.

Visit-to-visit blood pressure variability and sleep architecture

Visit-to-visit blood pressure (BP) variability (BPV) is an independent risk factor of cardiovascular disease (CVD). Sleep architecture characterizes the distribution of different stages of sleep and may be important in CVD development. We examined the association between visit-to-visit BPV and sleep architecture using in-lab polysomnographic data from 3,565 patients referred to an academic sleep center. BPV was calculated using the intra-individual coefficient of variation of BP measures collected 12 months before the sleep study. We conducted multiple linear regression analyses to assess the association of systolic and diastolic BPV with sleep architecture-rapid eye movement (REM) and non-rapid eye movement (NREM) sleep duration. Our results show that systolic BPV was inversely associated with REM sleep duration (p = .058). When patients were divided into tertile groups based on their BPV, those in the third tertile (highest variability) spent 2.7 fewer minutes in REM sleep than those in the first tertile (lowest variability, p = .032), after adjusting for covariates. We did not find an association of systolic BPV with other measures of sleep architecture. Diastolic BPV was not associated with sleep architecture either. In summary, our study showed that greater systolic BPV was associated with lower REM sleep duration. Future investigation is warranted to clarify the directionality, mechanism, and therapeutic implications.

Visit-to-Visit Blood Pressure Variability Is Associated With Cognitive Decline and Incident Dementia: The S.AGES Cohort

To investigate the impact of visit-to-visit systolic blood pressure variability (BPV), diastolic BPV, mean arterial pressure variability, and pulse pressure variability on cognitive decline and incident dementia in noninstitutionalized patients aged ≥65 years. A total of 3319 subjects from the S.AGES (Sujets AGÉS-Aged Subjects) cohort underwent clinical examinations every 6 months during 3 years. Variability was evaluated using standard deviation (SD), coefficient of variation, average real variability, successive variation, variation independent of mean, and residual SD. Cognition was assessed using the Mini-Mental State Examination and dementia with the Diagnostic Statistical Manual of Mental Disorders. Linear mixed models and Cox proportional hazards models were used. Higher systolic BPV was associated with poorer cognition independently of baseline SBP: adjusted 1-SD increase of coefficient of variation: β (SE)=-0.12 (0.06), P=0.04. Similar results were observed for diastolic BPV and mean arterial pressure variability: β (SE)=-0.20 (0.06), P<0.001 for both. Higher pulse pressure variability was no longer associated with cognitive function after adjustment for age, except with residual SD (P=0.02). Among the 3319 subjects, 93 (2.8%) developed dementia. Higher systolic BPV was associated with greater dementia risk (adjusted 1-SD increase of coefficient of variation: hazard ratios=1.23 [95% CI, 1.01-1.50], P=0.04). Similar results were found for diastolic BPV and mean arterial pressure variability (P<0.01). Pulse pressure variability was not associated with dementia risk. Beyond hypertension, higher BPV is a major clinical predictor of cognitive impairment and dementia. Further studies are needed to assess whether controlling BP instability could be a promising interventional target in preserving cognition among older adults.

Effect of Visit-to-Visit Blood Pressure Variability on Cognitive and Functional Decline in Mild to Moderate Alzheimer's Disease

BACKGROUND

Visit-to-visit blood pressure (BP) variability (VVV) is increasingly recognized as a marker of cardiovascular risk. Although implicated in cognitive decline, few studies are currently available assessing its effects on established dementia.

OBJECTIVE

To investigate if VVV is associated with one-year rate of decline in measures of cognition and function in patients with mild to moderate Alzheimer's disease (AD) in the Doxycycline And Rifampicin for Alzheimer's Disease study.

METHODS

Patients were included if ≥3 BP readings were available (n = 392). VVV was defined using different approaches including the coefficient of variation (CV) in BP readings between visits. Outcomes included rates of decline in the Standardized Alzheimer's Disease Assessment Scale-Cognitive Subscale (SADAS-cog), Standardized MMSE, Clinical Dementia Rating Scale, the Quick Mild Cognitive Impairment screen and the Lawton-Brody activities of daily living (ADL) scale.

RESULTS

Half of the patients (196/392) had a ≥4-point decline in the SADAS-cog over one-year. Using this cut-off, there were no statistically significant associations between any measures of VVV, for systolic or diastolic BP, with and without adjustment for potential confounders including treatment allocation, history of hypertension and use of anti-hypertensive and cognitive enhancing medications. Multiple regression models examining the association between systolic BP CV by quartile and decline over one-year likewise showed no clinically significant effects, apart from a U-shaped pattern of ADL decline of borderline clinical significance.∥Conclusions: This observational study does not support recent research showing that VVV predicts cognitive decline in AD. Further studies are needed to clarify its effects on ADL in AD.

Association between Vitamin B12 levels and cognitive function in the elderly Korean population

Vitamin B12 (B12), also known as cobalamin, is a water-soluble vitamin. It is a cofactor in DNA synthesis and is involved in the metabolism of every cell of the human body, including the central nervous system. Those with a deficiency of B12 can present with peripheral neuropathy, pernicious anemia, or a cognitive disorder. Previous studies have revealed that a deficiency of B12 is associated with cognitive decline or Alzheimer disease.The data of 2991 people were evaluated from 2 years of the Korean Frailty and Aging Cohort Study, a nationwide multicenter survey. To assess cognitive function, a short form of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) was used. Of the CERAD-K tests, we included the Mini-Mental State Examination in the Korean version of the CERAD assessment packet (MMSE-KC), the word list: memory/recall/recognition, digit span (forward, backward), trail making test-A, and the frontal assessment battery. B12 concentrations were classified into clinically relevant categories, insufficient (<350 pg/mL) and sufficient (≥350 pg/mL). A linear regression analysis was used to evaluate the relationship between cognitive function and B12 levels.The mean age of the 2991 participants was 76.4 ± 3.9 years old. Overall, 414 (13.8%) were classified as B12 insufficient, and 2577 (86.2%) as B12 sufficient. The sufficient B12 group performed better in the MMSE-KC, Wordlist: memory, Wordlist: recognition, TMT-A test, digit span, and FAB tests. This was statistically significant (P < .05). However, in the multivariable linear regression analysis, after adjusting for age, sex, education period, marriage, smoking and drinking habits, and comorbidities, the association between the B12 group and cognitive function was not statistically significant.Although our study does not show that B12 insufficiency is a direct risk factor to cognitive decline, B12 levels could be a contributing factor to cognitive function. Our results suggest that cognition was affected by the B12 levels, along with demographic and sociological variables.

Examining the Link Between Cardiovascular Risk Factors and Neuropsychiatric Symptoms in Mild Cognitive Impairment and Major Depressive Disorder in Remission

BACKGROUND

Cardiovascular risk factors (CVRFs) have been linked to both depression and cognitive decline but their role in neuropsychiatric symptoms (NPS) has yet to be clarified.

OBJECTIVE

Understanding the role of CVRFs in the etiology of NPS for prospective treatments and preventive strategies to minimize these symptoms.

METHODS

We examined the distribution of NPS using the Neuropsychiatric Inventory (NPI) scores in three cohorts from the Prevention of Alzheimer's Dementia with Cognitive Remediation Plus Transcranial Direct Current Stimulation in Mild Cognitive Impairment and Depression (PACt-MD) study: older patients with a lifetime history of major depressive disorder (MDD) in remission, patients with mild cognitive impairment (MCI), and patients with combined MCI and MDD. We also examined the link between individual NPS and CVRFs, Framingham risk score, and Hachinski ischemic score in a combined sample.

RESULTS

Analyses were based on a sample of 140 subjects, 70 with MCI, 38 with MCI plus MDD, and 32 with MDD. There was no effect of age, gender, education, cognition, or CVRFs on the presence (NPI >1) or absence (NPI = 0) of NPS. Depression was the most prevalent affective NPS domain followed by night-time behaviors and appetite changes across all three diagnostic groups. Agitation and aggression correlated negatively while anxiety, disinhibition, night-time behaviors, and irritability correlated positively with CVRFs (all p-values <0.05). Other NPS domains showed no significant association with CVRFs.

CONCLUSION

CVRFs are significantly associated with individual NPI sub-scores but not with total NPI scores, suggesting that different pathologies may contribute to different NPS domains.

Association between red cell distribution width level and risk of stroke: A systematic review and meta-analysis of prospective studies

BACKGROUND

Red cell distribution width level may have relations with the incidence and prognosis of cerebrovascular diseases. Recent researches have reported that red cell distribution width level was linked to the occurrence of stroke. However, the predicted effect of red cell distribution width in stroke is still disputed. We sought to assess the relationship between red cell distribution width and risk of stroke in this meta-analysis.

METHODS

Relevant studies were picked out from the databases of Embase, PubMed, and Cochrane Library. Hazard ratio with 95% confidence interval was chosen to analyze each trial, which was extracted from results of the highest and lowest red cell distribution width group. Funnel plots, Begg and Egger test were used to assess publication bias in the meta-analysis. Stata(12.0) was utilized to perform statistic analysis in the process.

RESULTS

A total of 6 studies with 5783 patients were included in this meta-analysis. The results showed that red cell distribution width level in patients with stroke was significantly higher than it in those without stroke (HR = 1.34, 95%CI:1.23-1.47, P < .001), in particular ischemic stroke(HR = 1.34,95% confidence interval:1.1-1.54, P < .001). There was no evidence of heterogeneity across the studies (P = .355, I = 5.53%).

CONCLUSIONS

The higher red cell distribution width level was associated with an increased risk of stroke, especially ischemic infarction.

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

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

Oral Administration of Alpha Linoleic Acid Rescues Aβ-Induced Glia-Mediated Neuroinflammation and Cognitive Dysfunction in C57BL/6N Mice

In this work, we evaluated the effects of alpha linoleic acid (ALA), an omega-3 polyunsaturated fatty acid, on amyloid-beta-induced glial-cell-mediated neuroinflammation, amyloidogenesis, and cognitive dysfunction in mice. After an infusion of Aβ_1-42 (Aβ_1-42, 5 μL/5 min/mouse, intracerebroventricular injection (i.c.v), and respective treatments of ALA (60 mg/kg per oral for six weeks), neuroinflammation, apoptotic markers, and synaptic markers were evaluated by Western blot and immunofluorescence analyses. According to our findings, the infusion of Aβ_1-42 activated Toll-like receptor 4 (TLR4), glial fibrillary acidic protein (GFAP), and ionized calcium adaptor molecule 1 (Iba-1) in the frontal cortices and hippocampi of the Aβ_1-42-injected mice to a greater extent than the Aβ_1-42 + ALA-cotreated mice. Similarly, there was an elevated expression of phospho-c-Jun-N-terminal kinase (p-JNK), phospho-nuclear factor-kB p65 (p-NF-kB p65 (Ser536)), and tissue necrosis factor (TNF) in the Aβ_1-42 infused mouse brains; interestingly, these markers were significantly reduced in the Aβ + ALA-cotreated group. The elevated expression of pro-apoptotic markers was observed during apoptotic cell death in the Aβ_1-42-treated mouse brains, whereas these markers were markedly reduced in the Aβ + ALA-cotreated group. Moreover, Aβ_1-42 infusion significantly increased amyloidogenesis, as assessed by the enhanced expression of the amyloid precursor proteins (APP) beta-amyloid cleaving enzyme-1 (BACE-1) and amyloid-beta (Aβ_1-42) in the mouse brains, whereas these proteins were markedly reduced in the Aβ + ALA-cotreated group. We also checked the effects of ALA against Aβ-triggered synaptic dysfunction and memory dysfunction, showing that ALA significantly improved memory and synaptic functions in Aβ-treated mouse brains. These results indicated that ALA could be an applicable intervention in neuroinflammation, apoptotic cell loss, amyloidogenesis, and memory dysfunction via the inhibition of TLR4 and its downstream targets in Aβ + ALA-cotreated mouse brains.

Effects of vitamin C supplementation on essential hypertension: A systematic review and meta-analysis

BACKGROUND

Vitamin C as a supplement to treat hypertension has been proposed. However, it remains controversial whether vitamin C can improve blood pressure in patients with primary hypertension.

OBJECTIVES

To analyze the effect of vitamin C (VitC) supplementation on systolic (SBP) and diastolic (DBP) blood pressure in patients with essential hypertension.

METHODS

We searched the Chinese Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, WANFANG Data, Cochrane Library, National Library of Medicine's PubMed, EMBASE, and other databases until June 2019. Eight RCTs involving 614 participants were analyzed. SBP and DBP before and after VitC supplementation were compared between the intervention and control groups. The risk of bias of individual studies was assessed using the Cochrane Collaboration risk of bias tool. Two reviewers selected studies independently of each other. The Cochrane Collaboration Review Manager 5.3 was used to perform the meta-analysis.

RESULTS

There was a significant difference in the change of SBP (weighted mean difference [WMD] = -4.09; 95% confidence interval [CI] -5.56, -2.62; P < .001) and DBP (WMD = -2.30; 95% CI -4.27, -.331; P = .02) between the groups. Further, there was a significant difference in the SBP (WMD = -3.75, 95% CI -6.24, -1.26, P = .003) and DBP (WMD = -3.29, 95% CI -5.98, -.60, P = .02) for the subgroup with an age ≥60 years and that with ≥35 participants. In the subgroup analysis, result for SBP with a study duration ≥6 weeks was statistically significant different (WMD = -4.77; 95% CI -6.46, -3.08; P < .001). For an intervention dose of VitC ≥500 mg daily, SBP was statistically significant (WMD = -5.01; 95% CI -8.55, -1.48; P = .005).

CONCLUSION

VitC supplementation resulted in a significant reduction of blood pressure in patients with essential hypertension.

The Effect of Metformin on Polycystic Ovary Syndrome in Overweight Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Metformin is an important component of PCOS treatment. At present, the effect of metformin in overweight women with PCOS has not been evaluated. Therefore, we conducted a systematic review to assess the effects of metformin in overweight women with PCOS and to analyze the effects of metformin in overweight women with PCOS.

METHODS

We searched the PubMed, Cochrane Library, Embase, CNKI, VIP, and Wanfang databases for studies published before March 2020. Randomized controlled trials were identified to study the effects of metformin in overweight women with PCOS. Data from studies including body mass index (BMI), waist circumference (WC), follicle-stimulating hormone (FSH), homeostasis model assessment of insulin resistance (HOMA-IR), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglycerides (TG), fasting blood glucose (FBG), fasting insulin, testosterone, and androstenedione were pooled. Qualified trials were selected, and methodological quality was strictly assessed. Two reviewers chose the studies independently of each other.

RESULTS

Twelve trials were included. The intervention group and the control group had significant differences in the changes in body mass index (BMI) (WMD = -1.25, 95% CI (-1.60, -0.91), p < 0.00001) and waist circumference (WC) (WMD = -1.41, 95% CI (-2.46, -0.37), p=0.008) after metformin. The comprehensive results show that, in all studies, overweight women with polycystic ovary syndrome treated with metformin had significantly improved endocrine and metabolic indicators, including testosterone, follicle-stimulating hormone, luteinizing hormone, and low-density lipoprotein cholesterol. However, metformin did not regulate the secretion indexes of fasting insulin, homeostasis model assessment of insulin resistance, sex hormone-binding globulin, high-density lipoprotein cholesterol, total cholesterol, triglycerides, fasting blood glucose, and androstenedione.

CONCLUSIONS

Compared with control interventions, metformin appears to be an effective intervention for overweight women with PCOS.

Effect of hypertension status on the association between sleep duration and stroke among middle-aged and elderly population

We aimed to examine whether hypertension status modified the association between sleep duration and stroke among middle-aged and elderly population. This cross-sectional study included 10 516 participants aged ≥45 years from the China Hypertension Survey study. Sleep duration and history of stroke were assessed by questionnaires. Multivariate logistic regression analyses, a generalized additive model (GAM) and smooth curve fitting (penalized spline method) and a two-piecewise logistic regression models were performed to evaluate the association between sleep duration and stroke in different status of hypertension. 95% confidence interval (CI) for turning point was obtained by bootstrapping. Multiple logistic analyses showed that per 1 hour increase in sleep duration was associated with a 37% increased prevalence of stroke among participants without hypertension and associated with a 8% increased prevalence of stroke among hypertensive participants (without hypertension: odds ratio [OR] = 1.37, 95% CI 1.09-1.71; with hypertension: OR = 1.08, 95% CI 0.95-1.21; P_Interaction  = .029). The fully adjusted smooth curves presented a linear association between sleep duration and stroke among participants without hypertension, but a threshold, nonlinear association among hypertensive participants. The turning point for the curve was found at a sleep duration of 8 (95% CI 5-9) h among hypertensive patients. The ORs (95% CIs) for stroke were 0.92 (0.79, 1.06) and 1.60 (1.23, 2.08) to the left and right of the turning point, respectively. In conclusion, we found a linear association between sleep duration and stroke among middle-aged and elderly participants without hypertension, but a threshold, nonlinear association among hypertensive participants.

Chart review of patients receiving valsartan-amlodipine single-pill combination versus valsartan and amlodipine combination for blood pressure goal achievement and effects on the Hamilton anxiety rating/Hamilton depression rating scales

This study aimed to compare the Hamilton anxiety rating/Hamilton depression rating (HAMA/HAMD) scale scores and blood pressure (BP) goal achievement associated with the use of valsartan-amlodipine single-pill combinations (SPCs) versus valsartan and amlodipine combination in adult hypertensive patients.A total of 476 hypertensive patients were randomly assigned into the SPC (valsartan-amlodipine) and control (valsartan and amlodipine combination) groups. All patients had an uncontrolled BP (160-179/100-109 mm Hg). BP goal was <140/90 mm Hg. Cox proportional hazards regression analysis was used to analyze the likelihood of HAMA/HAMD scales, SPCs, control group, and daily dosage number. Kaplan-Meier analysis was used to estimate the rates of BP goal achievement over time among the 2 groups.A total of 476 patients were included in the study, and 439 patients completed the follow-up and received the index drug therapy. There was a significant difference in BP between the 2 groups on days 28, 42, and 56. Patients who received SPCs had a significantly higher rate of BP goal achievement over time (P = .000). The average HAMD scores in the SPC and control groups were 5.54 and 5.49 and 6.06 and 6.21 on days 28 and 56, respectively. The average HAMA scores in the SPC and control groups were 7.41 and 7.13 and 7.90 and 8.01 on days 28 and 56, respectively. The means of HAMD and HAMA scores were 5.826 and 7.614, respectively. The higher the HAMA/HAMD scores, the lower was the BP goal achievement. The number of drugs taken by the patients was associated with the HAMA and HAMD scores. There was no significant difference between HAMA scores of patients taking 1 tablet daily (7.22 ± 1.885) and those taking two-tablets daily (7.38 ± 1.953) (P = .408). However, when these scores were compared to those of patients taking 4 tablets daily (8.08 ± 2.285), a significant difference was observed (P = .000, P = .000).Hypertensive patients treated with valsartan-amlodipine SPCs were significantly more likely to achieve BP goal and have lesser HAMA/HAMD scores compared to patients treated with valsartan and amlodipine combination.

High prevalence of sleep disorders and behavioral and psychological symptoms of dementia in late-onset Alzheimer disease: A study in Eastern China

Alzheimer disease (AD) is the most common neurodegenerative brain disease that causes cognitive impairment in the elderly. Behavioral and psychological symptoms of dementia (BPSD), also known as neuropsychiatric symptoms, represent a heterogeneous group of non-cognitive symptoms and behaviors for AD patients. Sleep disorder is one closely-related psychiatric symptom of AD. In this cross-section study, we aimed to investigate the characteristics of sleep status and BPSD among AD patients in Eastern China and to assess the relationship among sleep disorder, BPSD, and cognition.A total of 176 participants were enrolled in the study, including 84 AD patients and 92 healthy individuals as controls. Mini-mental state examination (MMSE), cooperative study-activities of daily living (ADCS-ADL) and clinical dementia rating (CDR) were used to measure cognition, the competence in basic and instrumental activities of daily living, and severity of dementia, respectively. BPSD were evaluated by neuropsychiatric inventory (NPI). Pittsburgh sleep quality index (PSQI) and Epworth sleepiness scale were designed to assess the sleep status and daytime naps. Spearman correlation analyses were performed to determine the relations between PSQI, MMSE, ADCS-ADL, and NPI scores and CDR.Sleep disorders occurred in 55.9% of AD patients versus only 15.2% of controls. 89.2% of AD patients had BPSD while only 22.9% of controls did, with apathy (64.2%) the most common among AD patients. Among AD patients, PSQI was negatively correlated with both MMSE (r = -0.600, P < .01) and ADCS-ADL (r = -0.725, P < .01), and was positively correlated with total NPI score (r = 0.608, P < .01). PSQI was closely associated with depression (r = 0.653, P < .01) and apathy (r = 0.604, P < .01).This study showed that AD patients have a higher prevalence of sleep disorders and BPSD than healthy elderly adults. Sleep disorders affect cognition of AD patients and increase apathy and depression. These results can help investigate new therapeutic targets in AD treatments.

Comparison of prevalence and associated risk factors of cognitive function status among elderly between nursing homes and common communities of China: A STROBE-compliant observational study

Dementia among elderly is a serious problem worldwide. This study was conducted to estimate the prevalence and associated risk factors of dementia and mild cognitive impairment (MCI) in nursing homes (NHs) and common communities (CCs) among elderly in China.A cross-sectional survey was conducted in 4 communities across 12 cities in Southern China from May to November of 2014. Qualified psychiatrists and trained nurses carried out relevant diagnosis, assessments, interviews, and information collection. Screening test of mini-mental state examination was conducted among participants firstly, then confirmed diagnosis was carried out among the ones with positive results. Student t test, χ test, univariate, and multivariate logistic regression analysis were conducted to analyze data.A total of 2015 participants aged 65 or older were included in the final analysis; 908 came from NHs while 1107 came from CCs. The crude prevalence rates of dementia and MCI were 22.0% and 15.8%, respectively among all the participants. Dementia prevalence was 42.4% among those living in NHs, which was significantly higher than that of 5.3% in CCs (P < .0001). There were more moderate and severe dementia in NHs compared with CCs (P < .0001). It showed that older age, illiterate compared with high level of education (adjusted odds ratio, AOR = 3.32, 95% CI: 1.53-7.21), heavy drinking (AOR = 1.51 (1.00-2.24), having a medical history of diabetes (AOR = 1.41, 95% CI: 1.02-2.33), and stroke (AOR = 1.21, 95% CI: 1.01-1.23) were associated with dementia in NHs, and middle socioeconomic status might be a protective factor for dementia (AOR = 0.33, 95% CI: 0.21-0.51).The problem of senile dementia in NHs is much more serious than our estimation, and there are not enough trained nursing staffs in NHs. More population-based strategies in NHs, including conducting cognitive screening accompanied with routine physical examination among elderly population, carrying out related primary prevention policies and public health services, and paying attention to some modifiable associated risk factors such as heavy smoking and drinking are needed.

Blood Pressure Variability and Progression of Clinical Alzheimer Disease

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

Clinical Trial Registration

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

Low-Frequency Fluctuations Amplitude Signals Exhibit Abnormalities of Intrinsic Brain Activities and Reflect Cognitive Impairment in Leukoaraiosis Patients

Background

This study aimed to explore the amplitude of low-frequency fluctuations (ALFF) for whole-brain in leukoaraiosis (LA) patients suffering from cognitive decline or impairment.

Material/Methods

Patients were selected by employing magnetic resonance imaging (MRI) technique. According to results of the clinical dementia rating and Montreal cognitive assessment (MoCA), patients were divided into 3 groups: LA patients diagnosed as vascular mild-cognitive impairment (LA-VaMCI, n=28), LA patients diagnosed as vascular-dementia (LA-VaD, n=18), and normal individuals (NC, n=28). Executive functions were evaluated by using the Stroop test and Trail Making Test (TMT). The higher scores in TMT test mean greater impairments. Changes for the ALFF were measured by using resting-state functional MRI (rs-fMRI) technique. Correlations between ALFF and cognition scores were analyzed.

Results

It was found that widespread differences in ALFF were present predominantly in the posterior cingulate cortex/precuneus (PCC/PCu) and in the right inferior temporal gyrus (ITG). Compared with the NC group, ALFF values in PCC/PCu were significantly decreased (F=3.273, P=0.022) and ALFF values were significantly increased (F=2.864, P=0.033) in temporal regions of the LA-VaD patients. ALFF values in LA-VaMCI patients were significantly increased in ITG compared to that in the NC group (F=1.064, P=0.042) and the LA-VaD group (F=2.725, P=0.037). Impairment in executive functions were positively correlated with average ALFF of the left PCu.

Conclusions

This research showed that LA patients exhibited abnormal intrinsic-brain activities. Furthermore, altered ALFF was positively correlated with executive function scores.

Evaluation of hippocampal volume and serum brain-derived neurotrophic factor as potential diagnostic markers of conversion from amnestic mild cognitive impairment to Alzheimer disease: A STROBE-compliant article

Amnestic mild cognitive impairment (aMCI) is a transitional stage between normal aging and Alzheimer disease (AD), and is associated with an increased risk of AD. Many studies have shown that apolipoprotein E epsilon 4 (APOE ε4) genotype is a major genetic predictor of AD progression, especially in patients with aMCI. However, the application of APOE genotyping in the diagnosis of MCI progressing to AD is limited by its low sensitivity and specificity, which often leads to high false-positive rate. The aim of this study was to evaluate serum brain-derived neurotrophic factor (BDNF) and hippocampal volume as predictors of aMCI to AD transition in APOE ε4 genotype patients.A total of 178 subjects were diagnosed with aMCI. The patients with aMCI that progressed to AD within 2 years were included in the MCI-AD group (n = 86), those maintaining an aMCI diagnosis after 2 years were placed in the MCI-MCI group (n = 92), and neurologically healthy age-matched individuals were set as controls (n = 90). APOE genotypes were determined. Blood samples from all subjects were drawn at baseline, 12 months, and 24 months for serum BNDF assessments. Hippocampal delineations were monitored by magnetic resonance imaging.Compared to control group, aMCI-AD patients (the patients with aMCI that progressed to AD within 2 years) exhibited worse performance on cognitive and neuropsychological batteries. Meanwhile, we found that aMCI-AD patients were associated with abnormally low serum BDNF level and greater hippocampal volume loss than MCI-MCI patients (patients maintaining an aMCI diagnosis after 2 years). Moreover, patients with aMCI who were carriers of APOE ε4 showed a notable decrease in serum BDNF and a significant reduction in hippocampal volume, especially in those who progressed to AD.The present study demonstrates that aMCI that evolves into AD in patients with the APOE ε4 genotype may be predicted by hippocampal volume and serum BDNF.

Visit-to-visit variability of metabolic parameters and risk of heart failure: A nationwide population-based study

BACKGROUND

This study examined the effects of variability of four metabolic parameters, namely systolic blood pressure (BP), body mass index (BMI), fasting blood glucose (FBG), and total cholesterol level (TC) on the risk of HF. The effects of metabolic parameter variability on the risk of heart failure (HF) remain unclear.

METHODS

We studied individuals aged ≥40 years who had undergone ≥3 health check-ups under the Korean National Health Insurance Corporation during 2009 and 2012, and those who did not have hypertension, diabetes, or dyslipidemia. BP, BMI, FBG, and TC were measured at every visit. We defined the variability of each parameter using the variability independent of the mean (VIM) method. VIMs were categorized into four groups according to quartiles. The metabolic variability (MV) score for each subject was defined as the number of VIMs in the highest quartile.

RESULTS

Among the 3,820,191 subjects, 17,253 (0.45%) had incident HF during a mean 5.3 ± 1.1 years of follow-up. High variability of each parameter was associated with increased HF risk, which increased according to the MV score. After multivariable adjustment, compared to subjects with MV score = 0, subjects with MV score = 1-4 had an increased risk of HF (adjusted HR [95% CI], 1.15 [1.10-1.19] for MV score = 1, 1.33 [1.28-1.39] for MV score = 2, 1.48 [1.40-1.57] for MV score = 3, 1.74 [1.55-1.96] for MV score = 4 [p-for-trend ≪0.0001]).

CONCLUSIONS

High variability of BP, BMI, FBG, and TC was synergistically associated with a higher incidence of new-onset HF.

Acupuncture Administration Improves Cognitive Functions and Alleviates Inflammation and Nuclear Damage by Regulating Phosphatidylinositol 3 Kinase (PI3K)/Phosphoinositol-Dependent Kinase 1 (PDK1)/Novel Protein Kinase C (nPKC)/Rac 1 Signaling Pathway in Senescence-Accelerated Prone 8 (SAM-P8) Mice

BACKGROUND Alzheimer's disease (AD) is an age-associated neurodegenerative disorder. This study aimed to investigate effects of acupuncture administration on cognitive function and associated mechanisms. MATERIAL AND METHODS Senescence-accelerated prone 8 (SAM-P8) mice were randomly divided into 3 groups: the SAM-P8 group (P8-CN), the SAM-P8 administrating with acupuncture (P8-Acup) group, and the SAM-P8 administrating without acupuncture (P8-Sham) group. Morris water maze test was conducted to evaluate cognitive functions (memory and learning ability). PDK1, nPKC, and Rac1 inhibitors were used to treat SAM-P8 mice. Transmission electron microscope analysis was used to examine nuclear damage hippocampal tissues. Hematoxylin and eosin (H&E) staining was employed to evaluate inflammation. Western blot was used to detect PI3K, PDK1, nPKC, and Rac 1 expression in hippocampal tissues. RESULTS Acupuncture administration significantly reduced PI3K, PDK1, nPKC, and Rac 1 levels compared to P8-CN group (P<0.05). Both acupuncture and enzyme inhibitors (NSC23766, Rottlerin, OSU03012) significantly improved cognitive functions, reduced inflammation, and alleviated nuclear damages of SAM-P8 mice compared to P8-CN group (P<0.05). Acupuncture significantly enhanced effects of inhibitors on inflammation and nuclear damages compared to inhibitor treatment single (P<0.05). Acupuncture significantly enhanced down-regulative effects of OSU03012 on PI3K and PDK1 levels, increased down-regulative effects of Rottlerin on nPKC and Rac 1 levels and enhanced effects of Rottlerin on Rac 1 compared to P8-CN group (P<0.05). CONCLUSIONS Acupuncture administration improved cognitive functions and alleviated inflammatory response and nuclear damage of SAM-P8 mice, by downregulating PI3K/PDK1/nPKC/Rac 1 signaling pathway. This study could provide potential insight for treating cognitive dysfunction and aging of AD patients.

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

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

Exosomes in Pathogenesis, Diagnosis, and Treatment of Alzheimer's Disease

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the accumulation of β-amyloid peptide 1-42 and phosphorylation of tau protein in the brain. Thus far, the transfer mechanism of these cytotoxic proteins between nerve cells remains unclear. Recent studies have shown that nanoscale extracellular vesicles (exosomes) originating from cells may play important roles in this transfer process. In addition, several genetic materials and proteins are also involved in intercellular communication by the secretion of the exosomes. That proposes novel avenues for early diagnosis and biological treatment in AD, based on exosome detection and intervention. In this review, exosome-related pathways of cytotoxic protein intercellular transfer in AD, and the effect of membrane proteins on exosomes targeting cells are first introduced. The advances in exosome-related biomarker detection in AD are summarized. Finally, the advantages and challenges of reducing cytotoxic protein accumulation via exosomal intervention for AD treatment are discussed. It is envisaged that future research in exosomes may well provide new insights into the pathogenesis, diagnosis, and treatment of AD.

Blood pressure variability and brain morphology in elderly women without cardiovascular disease

OBJECTIVE

To examine the relationship between blood pressure (BP) variability (BPV), brain volumes, and cognitive functioning in postmenopausal women with few modifiable cardiovascular risk factors.

METHODS

Study participants consisted of postmenopausal women enrolled in the Women's Health Initiative Memory MRI study (WHIMS-MRI) without cardiovascular disease, diabetes mellitus, hypertension, or current smoking at baseline (1996-1999). BP readings were taken at baseline and each annual follow-up visit. BPV was defined as the SD associated with a participant's mean BP across visits and the SD associated with the participant's regression line with BP regressed across visits. Brain MRI scans were performed between 2004 and 2006. Cognitive functioning was assessed at baseline and annually thereafter with the Modified Mini-Mental State Examination (3MSE) scoring until 2008. The final sample consisted of 558 women (mean age 69 years, median follow-up time [interquartile range] 8 [0.8] years).

RESULTS

In adjusted models including mean systolic BP, women in the highest tertile of systolic BPV had lower hippocampal volumes and higher lesion volumes compared to women in the lowest tertile. No relationship between BPV and 3MSE scoring was detected.

CONCLUSIONS

In postmenopausal women with few modifiable cardiovascular risk factors, greater visit-to-visit systolic BPV was associated with reductions in hippocampal volume and increases in lesion volumes at later life. These data add evidence to the emerging importance of BPV as a prognostic indicator even in the absence of documented cardiovascular risk factors.

Randomised controlled trial of a Calcium Channel or Angiotensin Converting Enzyme Inhibitor/Angiotensin Receptor Blocker Regime to Reduce Blood Pressure Variability following Ischaemic Stroke (CAARBS): a protocol for a feasibility study

INTRODUCTION

Raised blood pressure (BP) is common after stroke and is associated with a poor prognosis, yet trials of BP lowering in the immediate poststroke period have not demonstrated a benefit. One possible explanation for this may be that BP variability (BPV) rather than absolute levels predicts outcome, as BPV is increased after stroke and is associated with poor outcomes. Furthermore, there is evidence of distinct antihypertensive class effects on BPV despite similar BP-lowering effects. However, whether BPV in the immediate poststroke period is a therapeutic target has not been prospectively investigated.The objectives of this trial are to assess the feasibility and safety of recruiting patients following an acute ischaemic stroke or transient ischaemic attack (TIA) to an interventional randomised controlled trial comparing the effects of two different antihypertensive drug classes on BPV. Secondary exploratory objectives are to assess if different therapeutic strategies have diverse effects on levels of BPV and if this has an impact on outcomes.

METHODS

150 adult patients with first-ever ischaemic stroke or TIA who require antihypertensive therapy for secondary prevention will be recruited within 7 days of the event from stroke services across three sites. After baseline assessments they will be randomly assigned to treatment with a calcium channel blocker or ACE inhibitor/angiotensin receptor blocker-based regimen and followed up for a period of three months.

ETHICS AND DISSEMINATION

Ethical and regulatory approvals have been granted. Dissemination is planned via publication in peer-reviewed medical journals and presentation at relevant conferences.

TRIAL REGISTRATION NUMBER

ISRCTN10853487.

Peripapillary Retinal Nerve Fiber Layer Thickness in Patients with Alzheimer's Disease: A Comparison of Eyes of Patients with Alzheimer's Disease, Primary Open-Angle Glaucoma, and Preperimetric Glaucoma and Healthy Controls

BACKGROUND The aim of this study was to assess and compare peripapillary retinal nerve fiber layer (RNFL) thickness in patients with Alzheimer's disease (AD), primary open-angle glaucoma (POAG), preperimetric glaucoma (PPG), and healthy controls with the use of Spectral Domain Optical Coherence Tomography (SD-OCT). MATERIAL AND METHODS Thirty patients with AD, 30 patients with POAG, 30 patients with PPG, and 30 healthy controls were enrolled in this cross-sectional study. Only 1 randomly selected eye of each patient was analyzed. Every subject underwent a thorough ophthalmological examination and OCT of the optic disc. The peripapillary RNFL thickness in each of the 6 sectors and globally was analyzed. RESULTS The RNFL was thinnest in patients with POAG. The mean RNFL thickness value was 60.97±12.97 µm and it was significantly lower than in healthy controls (106.30±8.95 µm), patients with PPG (93.20±12.04 µm), and AD patients (95.73±13.52 µm). Mean RNFL thickness in patients with AD was significantly lower when compared to healthy controls, and was higher compared to eyes with POAG, while there were no significant differences compared to patients with PPG. CONCLUSIONS Neuronal damage in the central nervous system (CNS) also affects to retinal axons. A major problem is to distinguish the cause for a moderate decrease in the RNFL thickness. This is particularly true for patients with glaucoma who have not been diagnosed with changes in the visual field. It is not possible to distinguish the cause of a mild decrease in the RNFL thickness based on the SD-OCT. This may result in misdiagnosis of glaucoma, unnecessary use of anti-glaucoma eye drops, and a delayed diagnosis of AD.

Use of Multimodal Magnetic Resonance Imaging Techniques to Explore Cognitive Impairment in Leukoaraiosis

Leukoaraiosis, also referred to as white-matter hyperintensities (WMHs) or age-related white matter changes, is the most frequently seen lesion on brain magnetic resonance images (MRI) in the elderly. LA is a subject of intense research interest, and is correlated with stroke, cognitive impairment or dementia, disturbances, affective disorders, and poor prognoses. Rapid advances in neuroimaging have enabled greater understanding of LA associated with aging-related cognitive decline or dementia. Recently, the techniques of multimodal MRI, such as structural MRI (sMRI), resting-state functional MRI (rs-MRI), cerebrovascular reactivity (CVR), diffusion tensor imaging (DTI), magnetic resonance spectroscopy (MRS), and dynamic contrast-enhanced MRI (DCE-MRI), have been used to explore the underlying mechanism of cognitive impairment in patients with LA. These multimodal MRI techniques may provide further insights into the structural and functional changes of LA with cognitive dysfunction.