Relationship of vascular risk to the progression of Alzheimer disease

Interactions between nanoparticles and pathological changes of vascular in Alzheimer's disease

Emerging evidence suggests that vascular pathological changes play a pivotal role in the pathogenesis of Alzheimer's disease (AD). The dysfunction of the cerebral vasculature occurs in the early course of AD, characterized by alterations in vascular morphology, diminished cerebral blood flow (CBF), impairment of the neurovascular unit (NVU), vasculature inflammation, and cerebral amyloid angiopathy. Vascular dysfunction not only facilitates the influx of neurotoxic substances into the brain, triggering inflammation and immune responses but also hampers the efflux of toxic proteins such as Aβ from the brain, thereby contributing to neurodegenerative changes in AD. Furthermore, these vascular changes significantly impact drug delivery and distribution within the brain. Therefore, developing targeted delivery systems or therapeutic strategies based on vascular alterations may potentially represent a novel breakthrough in AD treatment. This review comprehensively examines various aspects of vascular alterations in AD and outlines the current interactions between nanoparticles and pathological changes of vascular.

Non-immune system comorbidity in neuromyelitis optica spectrum disorders

Comorbidities may influence the clinical features, prognosis, and treatment outcomes of neuromyelitis optica spectrum disorders (NMOSD). The aim of this study was to determine the status of non-immune system comorbidities in patients with NMOSD and the effect on treatment response and prognosis. We retrospectively collected data from all patients who met the 2015 NMOSD diagnostic criteria from the NMOSD database established by our center. Patients were divided into positive and negative groups based on the presence of non-immune disease comorbidities. Patient data, clinical characteristics, treatment response, prognosis, and mortality were compared between the two groups. A total of 138 patients with NMOSD plus comorbidities were included, and 404 patients without comorbidities were selected as controls. The average age at onset was older (45 years vs 38 years, P < 0.001), the mean body mass index was higher (23.12 vs 22.04, P = 0.042) and more patients experienced relapse after immunotherapy (68.5 % vs 54.5 %, P = 0.020) in the comorbidity group than in the non-comorbidity group. Multifocal central nervous system lesions as an initial symptom was more common in the comorbidity group than in the non-comorbidity group (30.4 % vs 18.32 %, P = 0.003). Further, more patients experienced severe vision attacks (28.3 % vs 15.8 %, P = 0.003) and severe motor attacks (30.4 % vs 11.9 %, P < 0.001) in the comorbidity group than in the non-comorbidity group. In conclusion, patients with NMOSD with comorbidities tended to be older, less responsive to treatment, and at a higher risk of vision loss and paralysis.

The Relationship Between Cardiovascular Disease Risk Score and Postoperative Delirium: The PNDABLE Study

Objective

We aimed to investigate the relationship between Framingham Heart Study general cardiovascular disease risk score (FHS–CVD risk score) and postoperative delirium (POD) among patients who had unilateral total knee arthroplasty performed under epidural anesthesia. Furthermore, we examined whether such a hypothesized relationship was mediated by the cerebrospinal fluid (CSF) biomarkers.

Methods

A total of 750 participants were included in the current study. And the data were drawn from the database obtained from the Perioperative Neurocognitive Disorder And Biomarker Lifestyle (PNDABLE) study. The preoperative cognitive function of participants was measured by using Mini-Mental State Examination (MMSE). The incidence of POD was assessed using the Confusion Assessment Method (CAM). The POD severity was measured using the Memorial Delirium Assessment Scale (MDAS). The POD CSF biomarkers included in the current study were: Aβ42, T-tau, P-tau, Aβ42/T-tau, and Aβ42/P-tau. The level of the CSF biomarkers was measured using the enzyme-linked immune-sorbent assay (ELISA) in the PNDABLE study. Linear regression analysis was performed to examine the relationship between the FHS–CVD risk score and the POD CSF biomarkers. Logistic regression was used to analyze the relationship between FHS–CVD risk score, POD CSF biomarkers, and POD incidence. The proposed mediating effect of CSF biomarkers was evaluated using Mediation Analysis with 10,000 bootstrapped iterations. The receiver operating characteristic (ROC) curve is chosen as the evaluation metric for assessing the efficacy of the FHS–CVD risk score in predicting POD.

Results

In the PNDABLE study, the overall incidence of POD was 22.9% with 37.2% in the higher vascular risk group and 7.9% in the lower vascular risk group. Multiple linear regression models showed that a higher preoperative FHS–CVD risk score was positively correlated with CSF T-tau (β = 0.218, P = 0.015) and P-tau level (β = 0.309, P &lt; 0.001) in the higher vascular risk group. After adjusting for age (40–90 years), gender, education, MMSE, smoking history, drinking history, hypertension, diabetes, and the presence of CHD (cardiovascular heart disease), the results of the logistic regression analysis demonstrated the effect of Aβ42 (OR = 0.994, 95% CI 0.992–0.996, P &lt; 0.001), Aβ42/T-tau (OR = 0.353, 95% CI 0.254–0.491, P &lt; 0.001), and Aβ42/P-tau (OR = 0.744, 95% CI 0.684–0.809, P &lt; 0.001) in protecting patients against POD. However, the FHS–CVD risk score (OR = 1.142, 95% CI 1.017–1.282, P = 0.025) and the remaining two biomarkers: T-tau (OR = 1.005, 95% CI 1.004–1.007, P &lt; 0.001) and P-tau (OR = 1.045, 95%CI 1.029–1.062, P &lt; 0.001) were identified as the risk factors. Mediation analyses revealed that the association between FHS–CVD risk score and POD was partially mediated by T-tau (proportion: 31.6%) and P-tau (proportion: 23.6%). The predictive power of the FHS–CVD risk score was validated by the ROC curve with an AUC of 0.7364.

Conclusion

Higher vascular risk score is one of the preoperative risk factors for POD, which is partly mediated by CSF biomarker tau protein.

Clinical Trial Registration

[www.clinicaltrials.gov], identifier [ChiCTR2000033439].

Incident stroke in patients with Alzheimer's disease: systematic review and meta-analysis

Vascular mechanisms are increasingly recognized in the pathophysiology of Alzheimer's disease (AD), but less is known about the occurrence of stroke in AD patients. We aimed to quantify the risk of stroke in patients with AD and compare the incidence rates (IR) of stroke in individuals without AD. Systematic search of Embase and MEDLINE between 1970 and 2020. Inclusion criteria: reports with ≥ 50 patients with non-familial AD, which reported the occurrence of stroke (all types) and/or ischemic stroke and/or intracerebral hemorrhage (ICH) during follow-up. Meta-analyses of pooled data using random-effects model were performed. IR were calculated for each study. Incidence rate ratios (IRR) were calculated for studies presenting a control-group without AD. Among 5109 retrieved studies, 29 (0.6%) fulfilled the inclusion criteria, reporting a total of 61,824 AD patients. In AD patients the IR were 15.4/1000 person-years for stroke (all types), 13.0/1000 person-years for ischemic stroke and 3.4/1000 person-years for ICH. When compared to controls without AD, incidence rate for ICH in AD patients was significantly higher (IRR = 1.67, 95%CI 1.43-1.96), but similar for ischemic stroke. Incident stroke is not a rare event in AD population. AD is associated with an increased risk of intracerebral hemorrhage which warrants further clarification.

Modifiable, Non-Modifiable, and Clinical Factors Associated with Progression of Alzheimer's Disease

There is an extensive literature relating to factors associated with the development of Alzheimer's disease (AD), but less is known about factors which may contribute to its progression. This review examined the literature with regard to 15 factors which were suggested by PubMed search to be positively associated with the cognitive and/or neuropathological progression of AD. The factors were grouped as potentially modifiable (vascular risk factors, comorbidities, malnutrition, educational level, inflammation, and oxidative stress), non-modifiable (age at clinical onset, family history of dementia, gender, Apolipoprotein E ɛ4, genetic variants, and altered gene regulation), and clinical (baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs). Although conflicting results were found for the majority of factors, a positive association was found in nearly all studies which investigated the relationship of six factors to AD progression: malnutrition, genetic variants, altered gene regulation, baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs. Whether these or other factors which have been suggested to be associated with AD progression actually influence the rate of decline of AD patients is unclear. Therapeutic approaches which include addressing of modifiable factors associated with AD progression should be considered.

Associations between metabolic syndrome and type of dementia: analysis based on the National Health Insurance Service database of Gangwon province in South Korea

BACKGROUND

Metabolic syndrome is a cluster of conditions that occur together, increasing the risk of cardiovascular disease. However, the relationship between metabolic syndrome and dementia has remained controversial. Using nationwide population cohort data, we investigated the association between metabolic syndrome and dementia, according to the dementia type.

METHODS

We analyzed data of 84,144 individuals, in the aged group of more than 60 years, between January 1, 2009, to December 31, 2009, at Gangwon province by using the information of the (Korean) National Health Insurance Service. After eight years of gap, in 2017, we investigated the relationship between metabolic syndrome and dementia. We classified Dementia either as dementia of the Alzheimer type (AD) or vascular dementia (VD). AD and VD were defined as per the criteria of International Classification of Disease, Tenth Revision, Clinical Modification codes. Multiple logistic regression analyses examined the associations between metabolic syndrome or five metabolic syndrome components and dementia. Analyses included factors like age, sex, smoking, alcohol, physical inactivity, previous stroke, and previous cardiac disease.

RESULTS

Metabolic syndrome was associated with AD (OR = 11.48, 95% CI 9.03-14.59), not with VD. Each of five components of metabolic syndrome were also associated with AD. (high serum triglycerides: OR = 1.87, 95% CI 1.60-2.19; high blood pressure: OR = 1.85, 95% CI 1.55-2.21; high glucose: OR = 1.77, 95% CI 1.52-2.06; abdominal obesity: OR = 1.88, 95% CI 1.57-2.25; low serum high-density lipoprotein cholesterol: OR = 1.91, 95% CI 1.63-2.24) However, among components of metabolic syndrome, only the high glucose level was associated with VD. (OR = 1.26, 95% CI 1.01-1.56) body mass index (BMI), fasting glucose, and smoking were also associated with AD. (BMI: OR = 0.951, 95% CI 0.927-0.975; fasting glucose: OR = 1.003, 95% CI 1.001-1.005; smoking: OR = 1.020, 95% CI 1.003-1.039) A history of the previous stroke was associated with both AD and VD. (AD: OR = 1.827, 95% CI 1.263-2.644; VD: OR 2.775, 95% CI 1.747-4.406) CONCLUSIONS: Metabolic syndrome was associated with AD but not with VD. Patients with metabolic syndrome had an 11.48 times more likeliness to develop AD compared to those without metabolic syndrome. VD was associated only with several risk factors that could affect the vascular state rather than a metabolic syndrome. We suggested that the associations between metabolic syndrome and dementia would vary depending on the type of dementia.

Antihypertensive agents in Alzheimer's disease: beyond vascular protection

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

Mortality of Alzheimer's Disease Patients: A 10-Year Follow-up Pilot Study in Shanghai

BACKGROUND

Identifying risk factors and mortality of individuals with Alzheimer's disease (AD) could have important implications for the clinical management of AD.

OBJECTIVE

This pilot study aimed to examine the overall mortality of AD patients over a 10-year surveillance period in Shanghai, China. This study is an extension of our previous investigation on mortality of neurodegenerative diseases.

METHODS

One hundred and thirty-two AD patients recruited from the memory clinics of two hospitals in Shanghai in 2007 were followed up until December 31, 2017 or death, representing a follow-up period of up to 10 years. Overall standardized mortality ratios (SMRs) were calculated, and predictors for survival at recruitment were estimated.

RESULTS

Sixty-seven patients had died by December 31, 2017, and the SMR at 10 years of follow-up was 1.225 (95% confidence interval 0.944-1.563). Employing Cox's proportional hazard modeling, lower Mini-Mental State Examination score, and comorbid diabetes predicted poor survival in this cohort.

CONCLUSION

This pilot study suggests a similar survival trend of patients with AD compared to the general population in Shanghai urban region. Poor cognitive status and comorbid diabetes had a negative impact on the survival of AD patients.

From Stroke to Dementia: a Comprehensive Review Exposing Tight Interactions Between Stroke and Amyloid-β Formation

Stroke and Alzheimer’s disease (AD) are cerebral pathologies with high socioeconomic impact that can occur together and mutually interact. Vascular factors predisposing to cerebrovascular disease have also been specifically associated with development of AD, and acute stroke is known to increase the risk to develop dementia.

Despite the apparent association, it remains unknown how acute cerebrovascular disease and development of AD are precisely linked and act on each other. It has been suggested that this interaction is strongly related to vascular deposition of amyloid-β (Aβ), i.e., cerebral amyloid angiopathy (CAA). Furthermore, the blood–brain barrier (BBB), perivascular space, and the glymphatic system, the latter proposedly responsible for the drainage of solutes from the brain parenchyma, may represent key pathophysiological pathways linking stroke, Aβ deposition, and dementia.

In this review, we propose a hypothetic connection between CAA, stroke, perivascular space integrity, and dementia. Based on relevant pre-clinical research and a few clinical case reports, we speculate that impaired perivascular space integrity, inflammation, hypoxia, and BBB breakdown after stroke can lead to accelerated deposition of Aβ within brain parenchyma and cerebral vessel walls or exacerbation of CAA. The deposition of Aβ in the parenchyma would then be the initiating event leading to synaptic dysfunction, inducing cognitive decline and dementia. Maintaining the clearance of Aβ after stroke could offer a new therapeutic approach to prevent post-stroke cognitive impairment and development into dementia.

Summative Effects of Vascular Risk Factors on the Progression of Alzheimer Disease

OBJECTIVES

To investigate the summative effects of vascular risk factors (VRFs) on the progression of Alzheimer disease (AD).

DESIGN

Longitudinal follow-up cohort study.

SETTING

AD patients from two teaching hospitals in Taiwan with 3-year follow-ups.

PARTICIPANTS

A total of 330 AD patients with a mean age of 80.7 years, a mean Mini-Mental State Examination (MMSE) score 18.7, and a mean Clinical Dementia Rating Sum of Boxes (CDRSB) score of 6.9.

MEASUREMENTS

All patients completed a clinically functional assessment and a neuropsychological test battery at baseline and yearly follow-ups. The VRF burden was combined into a summative VRF index at baseline (ie, having one, two, or more VRFs); VRFs included coronary heart disease, cardiac arrhythmia, hypertension, cerebrovascular disease, diabetes mellitus, obesity, smoking, and physical inactivity. The generalized estimating equation (GEE) method was used to analyze the correlations between the VRFs and longitudinal MMSE and CDRSB changes.

RESULTS

The results of the GEE adjusted for age, years of education, sex, disease duration, baseline MMSE score, time, apolipoprotein E (APOE) ε4 carrier status, use of medications (acetylcholinesterase inhibitors or N-methyl-D-aspartate receptor antagonists), and hospitalization rates and showed that patients with more than three VRFs had more rapid cognitive decline than patients without VRFs (MMSE, P = .02; CDRSB, P = .001) as well as patients with three or fewer VRFs (MMSE, P = .009; CDRSB, P = .02). Subsequent analyses of APOE ε4 carriers with more than three VRFs also showed their more rapid cognitive decline compared with patients without VRFs (MMSE, P = .02; CDRSB, P = .001) and patients with three or fewer VRFs (MMSE, P = .009; CDRSB, P = .02), but no significant difference was found in APOE ε4 noncarriers.

CONCLUSION

Multiple VRFs have summative effects on the progression of AD, especially in APOE ε4 carriers. J Am Geriatr Soc 68:129-136, 2019.

Genome-wide association analysis of dementia and its clinical endophenotypes reveal novel loci associated with Alzheimer's disease and three causality networks: The GR@ACE project

INTRODUCTION

Large variability among Alzheimer's disease (AD) cases might impact genetic discoveries and complicate dissection of underlying biological pathways.

METHODS

Genome Research at Fundacio ACE (GR@ACE) is a genome-wide study of dementia and its clinical endophenotypes, defined based on AD's clinical certainty and vascular burden. We assessed the impact of known AD loci across endophenotypes to generate loci categories. We incorporated gene coexpression data and conducted pathway analysis per category. Finally, to evaluate the effect of heterogeneity in genetic studies, GR@ACE series were meta-analyzed with additional genome-wide association study data sets.

RESULTS

We classified known AD loci into three categories, which might reflect the disease clinical heterogeneity. Vascular processes were only detected as a causal mechanism in probable AD. The meta-analysis strategy revealed the ANKRD31-rs4704171 and NDUFAF6-rs10098778 and confirmed SCIMP-rs7225151 and CD33-rs3865444.

DISCUSSION

The regulation of vasculature is a prominent causal component of probable AD. GR@ACE meta-analysis revealed novel AD genetic signals, strongly driven by the presence of clinical heterogeneity in the AD series.

Discovering Biomarkers and Pathways Shared by Alzheimer's Disease and Ischemic Stroke to Identify Novel Therapeutic Targets

Background and objectives: Alzheimer's disease (AD) is a progressive neurodegenerative disease that results in severe dementia. Having ischemic strokes (IS) is one of the risk factors of the AD, but the molecular mechanisms that underlie IS and AD are not well understood. We thus aimed to identify common molecular biomarkers and pathways in IS and AD that can help predict the progression of these diseases and provide clues to important pathological mechanisms. Materials and Methods: We have analyzed the microarray gene expression datasets of IS and AD. To obtain robust results, combinatorial statistical methods were used to analyze the datasets and 26 transcripts (22 unique genes) were identified that were abnormally expressed in both IS and AD. Results: Gene Ontology (GO) and KEGG pathway analyses indicated that these 26 common dysregulated genes identified several altered molecular pathways: Alcoholism, MAPK signaling, glycine metabolism, serine metabolism, and threonine metabolism. Further protein-protein interactions (PPI) analysis revealed pathway hub proteins PDE9A, GNAO1, DUSP16, NTRK2, PGAM2, MAG, and TXLNA. Transcriptional and post-transcriptional components were then identified, and significant transcription factors (SPIB, SMAD3, and SOX2) found. Conclusions: Protein-drug interaction analysis revealed PDE9A has interaction with drugs caffeine, γ-glutamyl glycine, and 3-isobutyl-1-methyl-7H-xanthine. Thus, we identified novel putative links between pathological processes in IS and AD at transcripts levels, and identified possible mechanistic and gene expression links between IS and AD.

Alzheimer's Disease Progression: Factors Influencing Cognitive Decline

BACKGROUND

Alzheimer's disease (AD) patients present high variability in the rate of cognitive decline. Despite the wide knowledge on factors influencing dementia risk, little is known on what accounts for AD progression. Previous studies on this topic have mainly analyzed each factor separately without taking into account the interaction between genetic and non-genetic factors.

OBJECTIVE

The aim of the present study is to evaluate the role of demographic, clinical, therapeutic, and genetic factors and their interaction on cognitive decline among newly diagnosed AD patients.

METHODS

We retrospectively selected 160 AD patients diagnosed at the Neurology Unit of Careggi University Hospital of Florence. We evaluated the occurrence of rapid cognitive changes defined as the worsening of more than four points at the Mini-Mental State Examination after 2-year follow up period.

RESULTS

Among the 160 AD patients, 50% presented rapid disease progression. Extrapyramidal signs at disease onset were predictors of worse outcome (OR 2.2), especially among Apolipoprotein E (APOE) ɛ4 allele carriers, while the presence of family history for dementia decreased the risk of rapid progression by about 50%. Higher educated ɛ4-carriers showed a slower AD progression. We identified the chronic use of aspirin as potential secondary preventative strategy for the non ɛ4-carriers.

CONCLUSION

At dementia onset, some clinical and demographic data can be predictors of future progression. The outcomes of the present study support the already hypothesized interaction between genetic and non-genetic factors during disease course and suggest genetic-based approaches.

The Progression of Alzheimer's Disease: Are Fast Decliners Really Fast? A Four-Year Follow-Up

Background: The rate of cognitive and functional decline in Alzheimer’s disease (AD) changes across individuals.

Objectives: Our purpose was to assess whether the concept of “fast decline” really fits its definition and whether cognitive and functional variables at onset can predict the progression of AD.

Methods: 324 AD patients were included. We retrospectively examined their Mini-Mental State Examination (MMSE) total score and sub-items, Activities of Daily Living (ADL), and Instrumental Activities of Daily Living (IADL) at baseline and every six months for a 4-year follow-up. Patients were divided into “fast decliners” (n = 62), defined by a loss ≥5 points on the MMSE score within the first year from the baseline; “intermediate decliners” (n = 37), by a loss ≥5 points after the first year and before the 18th month; or “slow decliners” (n = 225), composed of the remaining patients.

Results: At baseline, the groups did not differ on demographic, clinical, and cognitive variables. The decline at the end of the 4-year follow-up period seems to be similar among the different decline clusters. Predictors of disease progression have not been identified; only the MMSE total score at 12 months <14/30 was indicative of a poor prognosis.

Conclusions: Even with the limitation due to the small sample size, the lack of differences in the disease progression in time in the different clusters suggest the inconsistency of the so-called “fast decliners”. This study was unable to show any significant difference among clusters of AD progression within a 4-year time interval. Further studies should better clarify whether a more consistent distinction exists between slow and fast decliners.

Behavioural inflexibility in a comorbid rat model of striatal ischemic injury and mutant hAPP overexpression

Alzheimer disease (AD) and stroke coexist and interact; yet how they interact is not sufficiently understood. Both AD and basal ganglia stroke can impair behavioural flexibility, which can be reliably modeled in rats using an established operant based set-shifting test. Transgenic Fischer 344-APP21 rats (TgF344) overexpress pathogenic human amyloid precursor protein (hAPP) but do not spontaneously develop overt pathology, hence TgF344 rats can be used to model the effect of vascular injury in the prodromal stages of Alzheimer disease. We demonstrate that the injection of endothelin-1 (ET1) into the dorsal striatum of TgF344 rats (Tg-ET1) produced an exacerbation of behavioural inflexibility with a behavioural phenotype that was distinct from saline-injected wildtype & TgF344 rats as well as ET1-injected wildtype rats (Wt-ET1). In addition to profiling the types of errors made, interpolative modeling using logistic exposure-response regression provided an informative analysis of the timing and efficiency of behavioural flexibility. During set-shifting, Tg-ET1 committed fewer perseverative errors than Wt-ET1. However, Tg-ET1 committed significantly more regressive errors and had a less efficient strategy change than all other groups. Thus, behavioural flexibility was more vulnerable to striatal ischemic injury in TgF344 rats.

Development of a core outcome set for disease modification trials in mild to moderate dementia: a systematic review, patient and public consultation and consensus recommendations

BACKGROUND

There is currently no disease-modifying treatment available to halt or delay the progression of the disease pathology in dementia. An agreed core set of the best-available and most appropriate outcomes for disease modification would facilitate the design of trials and ensure consistency across disease modification trials, as well as making results comparable and meta-analysable in future trials.

OBJECTIVES

To agree a set of core outcomes for disease modification trials for mild to moderate dementia with the UK dementia research community and patient and public involvement (PPI).

DATA SOURCES

We included disease modification trials with quantitative outcomes of efficacy from (1) references from related systematic reviews in workstream 1; (2) searches of the Cochrane Dementia and Cognitive Improvement Group study register, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, EMBASE, Latin American and Caribbean Health Sciences Literature and PsycINFO on 11 December 2015, and clinical trial registries [International Standard Randomised Controlled Trial Number (ISRCTN) and clinicaltrials.gov] on 22 and 29 January 2016; and (3) hand-searches of reference lists of relevant systematic reviews from database searches.

REVIEW METHODS

The project consisted of four workstreams. (1) We obtained related core outcome sets and work from co-applicants. (2) We systematically reviewed published and ongoing disease modification trials to identify the outcomes used in different domains. We extracted outcomes used in each trial, recording how many used each outcome and with how many participants. We divided outcomes into the domains measured and searched for validation data. (3) We consulted with PPI participants about recommended outcomes. (4) We presented all the synthesised information at a conference attended by the wider body of National Institute for Health Research (NIHR) dementia researchers to reach consensus on a core set of outcomes.

RESULTS

We included 149 papers from the 22,918 papers screened, referring to 125 individual trials. Eighty-one outcomes were used across trials, including 72 scales [31 cognitive, 12 activities of daily living (ADLs), 10 global, 16 neuropsychiatric and three quality of life] and nine biological techniques. We consulted with 18 people for PPI. The conference decided that only cognition and biological markers are core measures of disease modification. Cognition should be measured by the Mini Mental State Examination (MMSE) or the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog), and brain changes through structural magnetic resonance imaging (MRI) in a subset of participants. All other domains are important but not core. We recommend using the Neuropsychiatric Inventory for neuropsychiatric symptoms: the Disability Assessment for Dementia for ADLs, the Dementia Quality of Life Measure for quality of life and the Clinical Dementia Rating scale to measure dementia globally.

LIMITATIONS

Most of the trials included participants with Alzheimer's disease, so recommendations may not apply to other types of dementia. We did not conduct economic analyses. The PPI consultation was limited to members of the Alzheimer's Society Research Network.

CONCLUSIONS

Cognitive outcomes and biological markers form the core outcome set for future disease modification trials, measured by the MMSE or ADAS-Cog, and structural MRI in a subset of participants.

FUTURE WORK

We envisage that the core set may be superseded in the future, particularly for other types of dementia. There is a need to develop an algorithm to compare scores on the MMSE and ADAS-Cog.

STUDY REGISTRATION

The project was registered with Core Outcome Measures in Effectiveness Trials [ www.comet-initiative.org/studies/details/819?result=true (accessed 7 April 2016)]. The systematic review protocol is registered as PROSPERO CRD42015027346.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Use of benzodiazepines and related drugs is associated with a risk of stroke among persons with Alzheimer's disease

The aim of our study was to investigate the risk of any, ischemic, and hemorrhagic stroke associated with incident benzodiazepine and related drug (BZDR) use among community-dwelling individuals with Alzheimer's disease (AD). Data from the MEDALZ cohort including all community-dwelling persons newly diagnosed with AD between 2005 and 2011 in Finland were utilized. Incident BZDR users were identified with a 1-year washout period for previous use. Persons with a previous stroke were excluded, resulting in a final study sample of 45 050 individuals. Incident any, ischemic, and hemorrhagic strokes were identified from the Hospital Discharge and Causes of Death registers. The risk of stroke between time on BZDRs was compared with nonuse time with Cox proportional hazard models. During the follow-up, 21.9% (N=9879) of persons started BZDR use. Compared with nonuse, BZDR use was associated with an increased risk of any stroke [adjusted hazard ratio (aHR): 1.21; 95% confidence interval (CI): 1.04-1.40] and ischemic stroke (aHR: 1.21; 95% CI: 1.02-1.44), but the association between BZDR use and hemorrhagic stroke did not reach significance (aHR: 1.26; 95% CI: 0.91-1.74). Z-drug use was associated with a similar risk as benzodiazepine use. In conclusion, BZDR use was associated with an increased risk of stroke among older individuals with AD.

Molecular Links and Biomarkers of Stroke, Vascular Dementia, and Alzheimer's Disease

Stroke is a very common neurological disease, and it occurs when the blood supply to part of the brain is interrupted and the subsequent shortage of oxygen and nutrients causes damage to the brain tissue. Stroke is the second leading cause of death and the third leading cause of disability-adjusted life years. The occurrence of stroke increases with age, but anyone at any age can suffer a stroke. Stroke can be broadly classified in two major clinical types: ischemic stroke (IS) and hemorrhagic stroke. Research also revealed that stroke, vascular dementia (VaD), and Alzheimer's disease (AD) increase with a number of modifiable factors, and most strokes can be prevented and/or controlled through pharmacological or surgical interventions and lifestyle changes. The pathophysiology of stroke, VaD, and AD is complex, and recent molecular and postmortem brain studies have revealed that multiple cellular changes have been implicated, including inflammatory responses, microRNA alterations, and marked changes in brain proteins. These molecular and cellular changes provide new information for developing therapeutic strategies for stroke and related vascular disorders treatment. IS is the major risk factor for VaD and AD. This chapter summarizes the (1) links among stroke-VaD-AD; (2) updates the latest developments of research in identifying protein biomarkers in peripheral and central nervous system tissues; and (3) critically evaluates miRNA profile and function in human blood samples, animal, and postmortem brains.

Empirically Defining Trajectories of Late-Life Cognitive and Functional Decline

BACKGROUND

Alzheimer's disease (AD) is associated with variable cognitive and functional decline, and it is difficult to predict who will develop the disease and how they will progress.

OBJECTIVE

This exploratory study aimed to define latent classes from participants in the Alzheimer's Disease Neuroimaging Initiative (ADNI) database who had similar growth patterns of both cognitive and functional change using Growth Mixture Modeling (GMM), identify characteristics associated with those trajectories, and develop a decision tree using clinical predictors to determine which trajectory, as determined by GMM, individuals will most likely follow.

METHODS

We used ADNI early mild cognitive impairment (EMCI), late MCI (LMCI), AD dementia, and healthy control (HC) participants with known amyloid-β status and follow-up assessments on the Alzheimer's Disease Assessment Scale - Cognitive Subscale or the Functional Activities Questionnaire (FAQ) up to 24 months postbaseline. GMM defined trajectories. Classification and Regression Tree (CART) used certain baseline variables to predict likely trajectory path.

RESULTS

GMM identified three trajectory classes (C): C1 (n = 162, 13.6%) highest baseline impairment and steepest pattern of cognitive/functional decline; C3 (n = 819, 68.7%) lowest baseline impairment and minimal change on both; C2 (n = 211, 17.7%) intermediate pattern, worsening on both, but less steep than C1. C3 had fewer amyloid- or apolipoprotein-E ɛ4 (APOE4) positive and more healthy controls (HC) or EMCI cases. CART analysis identified two decision nodes using the FAQ to predict likely class with 82.3% estimated accuracy.

CONCLUSIONS

Cognitive/functional change followed three trajectories with greater baseline impairment and amyloid and APOE4 positivity associated with greater progression. FAQ may predict trajectory class.

Effects of Diabetes Mellitus on Cognitive Decline in Patients with Alzheimer Disease: A Systematic Review

Basic and clinical research support a link between diabetes mellitus and Alzheimer disease (AD). However, the relationship with AD progression is unclear. This review focuses on the association between diabetes and cognitive decline in patients with AD. The literature published through May 2015 was searched in 3 databases: PubMed, Embase and Cochrane. Studies evaluating the effects of diabetes on patients with AD or cognitive decline were included, and extracted data were analyzed. A total of 10 articles met the inclusion criteria for review. The results of these studies were inconsistent in terms of the association between diabetes and cognitive decline. Only 2 studies demonstrated that the presence of diabetes was independently related to the progression of cognitive decline in the patients with AD, and 3 studies suggested that histories of diabetes were not correlated with the changes in cognitive function in patients with AD. Half of the included studies even indicated that histories of diabetes were associated with lesser declines in cognitive function in patients with AD. Current evidence indicates that the link between diabetes and cognitive decline in patients with AD is uncertain. Further clinical studies are needed, with larger samples, long-term follow up and an extended battery of cognitive assessments.

Shared genetic contribution to Ischaemic Stroke and Alzheimer's Disease

OBJECTIVE

Increasing evidence suggests epidemiological and pathological links between Alzheimer's disease (AD) and Ischaemic Stroke (IS). We investigated the evidence that shared genetic factors underpin the two diseases.

METHODS

Using genome wide association study (GWAS) data from METASTROKE+ (15,916 IS cases and 68,826 controls) and IGAP (17,008 AD cases and 37,154 controls), we evaluated known associations with AD and IS. On the subset of data for which we could obtain compatible genotype-level data (4,610 IS cases, 1,281 AD cases and 14,320 controls), we estimated the genome-wide genetic correlation (rG) between AD and IS, and the three subtypes (cardioembolic, small vessel, large vessel), using genome-wide SNP data. We then performed a meta-analysis and pathway analysis in the combined AD and small vessel stroke datasets to identify the SNPs and molecular pathways through which disease risk may be conferred.

RESULTS

We found evidence of a shared genetic contribution between AD and small vessel stroke (rG(SE)=0.37(0.17); p=0.011). Conversely, there was no evidence to support shared genetic factors in AD and IS overall, or with the other stroke subtypes. Of the known GWAS associations with IS or AD, none reached significance for association with the other trait (or stroke subtypes). A meta-analysis of AD IGAP and METASTROKE+ small vessel stroke GWAS data highlighted a region (ATP5H/KCTD2/ICT1), associated with both diseases (p=1.8x10-8 ). A pathway analysis identified four associated pathways, involving cholesterol transport and immune response.

INTERPRETATION

Our findings indicate shared genetic susceptibility to AD and small vessel stroke and highlight potential causal pathways and loci. This article is protected by copyright. All rights reserved.

Cardiovascular risk factors are associated with increased lesion burden and brain atrophy in multiple sclerosis

BACKGROUND

Cardiovascular (CV) risk factors have been associated with changes in clinical outcomes in patients with multiple sclerosis (MS).

OBJECTIVES

To investigate the frequency of CV risks in patients with MS and their association with MRI outcomes.

METHODS

In a prospective study, 326 patients with relapsing-remitting MS and 163 patients with progressive MS, 61 patients with clinically isolated syndrome (CIS) and 175 healthy controls (HCs) were screened for CV risks and scanned on a 3T MRI scanner. Examined CV risks included hypertension, heart disease, smoking, overweight/obesity and type 1 diabetes. MRI measures assessed lesion volumes (LVs) and brain atrophy. Association between individual or multiple CV risks and MRI outcomes was examined adjusting for age, sex, race, disease duration and treatment status.

RESULTS

Patients with MS showed increased frequency of smoking (51.7% vs 36.5%, p = 0.001) and hypertension (33.9% vs 24.7%, p=0.035) compared with HCs. In total, 49.9% of patients with MS and 36% of HCs showed ≥ 2 CV risks (p = 0.003), while the frequency of ≥ 3 CV risks was 18.8% in the MS group and 8.6% in the HCs group (p = 0.002). In patients with MS, hypertension and heart disease were associated with decreased grey matter (GM) and cortical volumes (p < 0.05), while overweight/obesity was associated with increased T1-LV (p < 0.39) and smoking with decreased whole brain volume (p = 0.049). Increased lateral ventricle volume was associated with heart disease (p = 0.029) in CIS.

CONCLUSIONS

Patients with MS with one or more CV risks showed increased lesion burden and more advanced brain atrophy.

Biochemical and Radiological Markers of Alzheimer's Disease Progression

Alzheimer's disease (AD) is a neurodegenerative, inevitably progressive disease with a rate of cognitive, functional, and behavioral decline that varies highly from patient to patient. Although several clinical predictors of AD progression have been identified, to our mind in clinical practice there is a lack of a reliable biomarker that enables one to stratify the risk of deterioration. Identification of biomarkers that allow the monitoring of AD progression could change the way physicians and caregivers make treatment decisions. This review summarizes the results of studies on potential biochemical and radiological markers related to AD progression.

Long-term PM2.5 Exposure and Neurological Hospital Admissions in the Northeastern United States

BACKGROUND

Long-term exposure to fine particles (particulate matter ≤ 2.5 μm; PM2.5) has been consistently linked to heart and lung disease. Recently, there has been increased interest in examining the effects of air pollution on the nervous system, with evidence showing potentially harmful effects on neurodegeneration.

OBJECTIVE

Our objective was to assess the potential impact of long-term PM2.5 exposure on event time, defined as time to first admission for dementia, Alzheimer's (AD), or Parkinson's (PD) diseases in an elderly population across the northeastern United States.

METHODS

We estimated the effects of PM2.5 on first hospital admission for dementia, AD, and PD among all Medicare enrollees ≥ 65 years in 50 northeastern U.S. cities (1999-2010). For each outcome, we first ran a Cox proportional hazards model for each city, adjusting for prior cardiopulmonary-related hospitalizations and year, and stratified by follow-up time, age, sex, and race. We then pooled the city-specific estimates by employing a random effects meta-regression.

RESULTS

We followed approximately 9.8 million subjects and observed significant associations of long-term PM2.5 city-wide exposure with all three outcomes. Specifically, we estimated a hazard ratio (HR) of 1.08 (95% CI: 1.05, 1.11) for dementia, an HR of 1.15 (95% CI: 1.11, 1.19) for AD, and an HR of 1.08 (95% CI: 1.04, 1.12) for PD admissions per 1-μg/m3 increase in annual PM2.5 concentrations.

CONCLUSIONS

To our knowledge, this is the first study to examine the relationship between long-term exposure to PM2.5 and time to first hospitalization for common neurodegenerative diseases. We found strong evidence of association for all three outcomes. Our findings provide the basis for further studies, as the implications of such exposures could be crucial to public health.

CITATION

Kioumourtzoglou MA, Schwartz JD, Weisskopf MG, Melly SJ, Wang Y, Dominici F, Zanobetti A. 2016. Long-term PM2.5 exposure and neurological hospital admissions in the northeastern United States. Environ Health Perspect 124:23-29; http://dx.doi.org/10.1289/ehp.1408973.

Vascular Health and Genetic Risk Affect Mild Cognitive Impairment Status and 4-Year Stability: Evidence From the Victoria Longitudinal Study

OBJECTIVES

Mild cognitive impairment (MCI) is a high-risk condition for progression to Alzheimer's disease (AD). Vascular health is a key mechanism underlying age-related cognitive decline and neurodegeneration. AD-related genetic risk factors may be associated with preclinical cognitive status changes. We examine independent and cross-domain interactive effects of vascular and genetic markers for predicting MCI status and stability.

METHOD

We used cross-sectional and 2-wave longitudinal data from the Victoria Longitudinal Study, including indicators of vascular health (e.g., reported vascular diseases, measured lung capacity and pulse rate) and genetic risk factors-that is, apolipoprotein E (APOE; rs429358 and rs7412; the presence vs absence of ε4) and catechol-O-methyltransferase (COMT; rs4680; met/met vs val/val). We examined associations with objectively classified (a) cognitive status at baseline (not impaired congnitive (NIC) controls vs MCI) and (b) stability or transition of cognitive status across a 4-year interval (stable NIC-NIC vs chronic MCI-MCI or transitional NIC-MCI).

RESULTS

Using logistic regression, indicators of vascular health, both independently and interactively with APOE ε4, were associated with risk of MCI at baseline and/or associated with MCI conversion or MCI stability over the retest interval.

DISCUSSION

Several vascular health markers of aging predict MCI risk. Interactively, APOE ε4 may intensify the vascular health risk for MCI.

Latent classes of course in Alzheimer's disease and predictors: the Cache County Dementia Progression Study

OBJECTIVE

Several longitudinal studies of Alzheimer's disease (AD) report heterogeneity in progression. We sought to identify groups (classes) of progression trajectories in the population-based Cache County Dementia Progression Study (N = 328) and to identify baseline predictors of membership for each group.

METHODS

We used parallel-process growth mixture models to identify latent classes of trajectories on the basis of Mini-Mental State Exam (MMSE) and Clinical Dementia Rating sum of boxes scores over time. We then used bias-corrected multinomial logistic regression to model baseline predictors of latent class membership. We constructed receiver operating characteristic curves to demonstrate relative predictive utility of successive sets of predictors.

RESULTS

We fit four latent classes; class 1 was the largest (72%) and had the slowest progression. Classes 2 (8%), 3 (11%), and 4 (8%) had more rapid worsening. In univariate analyses, longer dementia duration, presence of psychosis, and worse baseline MMSE and Clinical Dementia Rating sum of boxes were associated with membership in class 2, relative to class 1. Lower education was associated with membership in class 3. In the multivariate model, only MMSE remained a statistically significant predictor of class membership. Receiver operating characteristic areas under the curve were 0.98, 0.88, and 0.67, for classes 2, 3, and 4 relative to class 1.

CONCLUSIONS

Heterogeneity in AD course can be usefully characterized using growth mixture models. The majority belonged to a class characterized by slower decline than is typically reported in clinical samples. Class membership could be predicted using baseline covariates. Further study may advance our prediction of AD course at the population level and in turn shed light on the pathophysiology of progression.

Monetary costs of agitation in older adults with Alzheimer's disease in the UK: prospective cohort study

OBJECTIVE

While nearly half of all people with Alzheimer's disease (AD) have agitation symptoms every month, little is known about the costs of agitation in AD. We calculated the monetary costs associated with agitation in older adults with AD in the UK from a National Health Service and personal social services perspective.

DESIGN

Prospective cohort study.

SETTING

London and the South East Region of the UK (LASER-AD study).

PARTICIPANTS

224 people with AD recruited between July 2002 and January 2003 and followed up for 54 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was health and social care costs, including accommodation costs and costs of contacts with health and social care services. Agitation was assessed using the Neuropsychiatric Inventory (NPI) agitation score.

RESULTS

After adjustment, health and social care costs varied significantly by agitation, from £29,000 over a 1 year period with no agitation symptoms (NPI agitation score=0) to £57,000 at the most severe levels of agitation (NPI agitation score=12; p=0.01). The mean excess cost associated with agitation per person with AD was £4091 a year, accounting for 12% of the health and social care costs of AD in our data, and equating to £2 billion a year across all people with AD in the UK.

CONCLUSIONS

Agitation in people with AD represents a substantial monetary burden over and above the costs associated with cognitive impairment.

Differential subtypes of diabetic older adults diagnosed with Alzheimer's disease

AIM

The clinical management of diabetic elderly patients with Alzheimer's disease (AD) is hindered by several difficulties. The present study aimed to clarify the clinical characteristics and pathophysiological properties of AD in diabetic older adults.

METHODS

A total of 91 patients with type 2 diabetes mellitus and 161 non-diabetic individuals who were diagnosed with AD were recruited. Diabetic patients were classified into two groups with glycated hemoglobin (HbA1c) < 7.0% or ≥ 7.0%. The demographics, cognition, daily-life function, metabolic changes, treatment, and behavioral and psychological symptoms of dementia (BPSD), as well as brain pathophysiology, were compared among the three groups.

RESULTS

Patients with higher HbA1c had increased diabetic vascular complications and impaired activities of daily living with decreased levels of serum high-molecular-weight adiponectin and 25-hydroxyvitamin D. Although cognitive status was similar among the three groups, BPSD, including apathy, overeating and excessive daytime sleeping appeared to be increased in the patients with HbA1c ≥ 7.0%. The frequency of apolipoprotein E4 carriers and of posterior cerebral hypoperfusion (AD-pattern) on single-photon emission computed tomography in poorly controlled diabetic subjects was similar to that in non-diabetic AD patients, whereas diabetic patients with HbA1c <7.0% included fewer apolipoprotein E4 carriers and fewer patients with an AD pattern on single-photon emission computed tomography.

CONCLUSION

Subtypes of older diabetic patients with AD were identified based on clinical features and brain pathophysiology. Physical and psychological complications of dementia are prevalent in patients with higher HbA1c. It seems likely that difficulties in the management of diabetes with AD are due not only to non-adherence to diabetes treatment, but also several symptoms and pathophysiological characteristics of dementia.

Pathogenesis and treatment of vascular cognitive impairment

SUMMARY 

Vascular cognitive impairment (VCI) defines a continuum of disorders ranging from mild cognitive impairment to full-blown dementia, attributable to cerebrovascular causes. Major morphological types – multi-infarct encephalopathy, strategic infarct type, subcortical arteriosclerotic leukoencephalopathy, multilacunar state, postischemic encephalopathy – result from systemic, cardiac and local large or small vessel disease. Cognitive decline is commonly caused by widespread small cerebrovascular lesions (CVLs) affecting regions/networks essential for cognition, memory and behavior. CVLs often coexist with Alzheimer-type and other pathologies, which interact in promoting dementia, but in many nondemented elderly individuals, mixed brain pathologies are also present. Due to the high variability of CVLs, no validated clinical and neuropathological criteria for VCI are available. Cholinesterase inhibitors and memantine produce small cognitive improvement but without essential effect. Antihypertensive treatment, cardiovascular control and lifestyle modifications reducing vascular risk factors are essential. Given its growing health, social and economic burden, prevention and treatment of VCI are a major challenge of neuroscience.

Vascular risk factors aggravate the progression of Alzheimer's disease: a 3-year follow-up study of Chinese population

PURPOSE

To explore the correlation of vascular risk factors for Alzheimer's disease (AD) in Chinese population.

METHODS

A total of 123 outpatients with probable AD followed up for 3 years were investigated. Severity of cognitive impairment and functional ability was assessed using Mini-Mental State Examination (MMSE) and modified activities of daily living (ADLs), respectively. The incidence of vascular risk factors was studied in patients with AD.

RESULTS

Univariate analysis showed significance difference in MMSE and ADL scores between patients with and without vascular risk factors (P < .05). Multiple regression analysis showed age, education, hyperhomocysteinemia, and hypertension were significant variables associated with annual MMSE, while there were no significant correlations between annual MMSE and sex, initial MMSE, diabetes, and so on.

CONCLUSIONS

Vascular risk factors are common comorbidities in patients with AD in China, with younger, better educated ones showing faster cognitive decline. Hypertension and hyperhomocysteinemia may also aggravate the progression, and it is important to prevent and treat patients with AD.

Single neuropsychological test scores associated with rate of cognitive decline in early Alzheimer disease

Alzheimer disease (AD) characteristically begins with episodic memory impairment followed by other cognitive deficits; however, the course of illness varies, with substantial differences in the rate of cognitive decline. For research and clinical purposes it would be useful to distinguish between persons who will progress slowly from persons who will progress at an average or faster rate. Our objective was to use neurocognitive performance features and disease-specific and health information to determine a predictive model for the rate of cognitive decline in participants with mild AD. We reviewed the records of a series of 96 consecutive participants with mild AD from 1995 to 2011 who had been administered selected neurocognitive tests and clinical measures. Based on Clinical Dementia Rating (CDR) of functional and cognitive decline over 2 years, participants were classified as Faster (n = 45) or Slower (n = 51) Progressors. Stepwise logistic regression analyses using neurocognitive performance features, disease-specific, health, and demographic variables were performed. Neuropsychological scores that distinguished Faster from Slower Progressors included Trail Making Test - A, Digit Symbol, and California Verbal Learning Test (CVLT) Total Learned and Primacy Recall. No disease-specific, health, or demographic variable predicted rate of progression; however, history of heart disease showed a trend. Among the neuropsychological variables, Trail Making Test - A best distinguished Faster from Slower Progressors, with an overall accuracy of 68%. In an omnibus model including neuropsychological, disease-specific, health, and demographic variables, only Trail Making Test - A distinguished between groups. Several neuropsychological performance features were associated with the rate of cognitive decline in mild AD, with baseline Trail Making Test - A performance best separating those who declined at an average or faster rate from those who showed slower progression.

Cognitive decline in patients with Alzheimer's disease and its related factors in a memory clinic setting, Shanghai, China

Objectives

Progressive cognitive decline is a characteristic hallmark of AD. It is important to identify prognostic markers to improve patient care and long-term planning. We aimed to identify the characteristics of disease progression in AD patients, focusing on cognitive decline and its related factors.

Methods

Clinically diagnosed AD patients in a memory clinic were followed. The mini–mental state examination (MMSE) and a battery of other neuropsychological tests were performed to assess the rate of cognitive decline and to analyze the related factors.

Results

A total of 165 AD patients were analyzed for cognitive changes. The MMSE scores declined at a rate of 1.52 points per year. Most neuropsychological test scores deteriorated significantly over time. Younger and early-onset AD patients deteriorated more rapidly than older and late-onset patients in global cognition and executive function. Men declined faster in memory but slower in attention than women. Higher education was associated with more rapid deterioration in visuo-spatial ability. Family history, hypertension and cerebral vascular disease were also associated with disease progression.

Conclusion

Attention, executive and visuo-spatial functions deteriorate at faster rates than other cognitive functions in AD patients. Age and age at onset were the main factors that associated with deterioration.

Under-provision of medical care for vascular diseases for people with dementia in primary care: a cross-sectional review

BACKGROUND

Vascular diseases contribute to the causation and progression of clinical dementia.

AIM

To evaluate the quality of medical care for vascular diseases provided to people with dementia, the patient and practice characteristics that influence quality, and to compare care with that provided to those without dementia.

DESIGN AND SETTING

Observational, cross-sectional review of primary care records of people with dementia from 52 general practices from five primary care trusts in the UK, and comparison with publicly available summary data on patients without dementia.

METHOD

A total of 700 patients with ≥1 diagnosed vascular disease or risk factor were identified from dementia registers. Quality of care was measured on 30 indicators from the UK Quality and Outcomes Framework (QOF) for hypertension, coronary heart disease, stroke, diabetes mellitus, atrial fibrillation, heart failure, and smoking. Overall quality of vascular care was calculated for each patient with dementia.

RESULT

Level of care received by people with dementia was significantly lower compared with those without dementia for 22 of 30 (73%) indicators; most notably for measurement processes such as peripheral pulses check and neuropathy testing for diabetes, and cholesterol measures for stroke. Among people with dementia, women, those in care homes, and those with fewer comorbid physical conditions and medications were associated with lower scores for overall quality of vascular care.

CONCLUSION

The quality of medical care provided to people with dementia with regard to vascular diseases is not concordant with quality, as defined by the QOF. Research is needed to improve access to high-quality care.

An overview of the LASER-AD study: a longitudinal epidemiological study of people with Alzheimer's disease

Research into the epidemiological, clinical characteristics and economic impact of dementia is critical to increase understanding and better inform care and policy, and empower people with Alzheimer's disease (AD) and their families to make preparations and timely decisions about accommodation, care and treatment. The LASER-AD longitudinal study of people with AD and their carers has contributed to our understanding of the progression, characteristics and costs of the disease, and to developing tools that help detect dementia earlier, and screen and identify problems experienced by carers. Our work on quality of life shows that even those with severe dementia can report this meaningfully, although family proxy ratings of quality of life do not necessarily mirror the views of the individual. Despite the impact of the disease process, people with AD experience well-being in adversity and still live fulfilling lives. The study highlights the high prevalence and severity of neuropsychiatric symptoms, carer anxiety, depression and abusive behaviour. It informs future directions for possible interventions, in particular the central role of carer coping strategies in predicting carer mental illness. Current research is building on our findings, which have also been used to inform national and international plans for managing people with dementia and their carers.

Rapid cognitive decline in Alzheimer's disease: a literature review

BACKGROUND

The rate of cognitive decline in Alzheimer's disease (AD) varies considerably between individuals. Predicting rapid cognitive decline might help clinicians provide prognostic information, select subjects for trial intervention and/or reduce costs.

METHODS

PubMed and PsycINFO were searched for all the English written studies published until the end of 2010 on rapid cognitive decline in AD and factors associated with it.

RESULTS

More than 300 individual articles were retrieved. We selected 82 relevant studies. The main findings of these papers are that younger, more educated and more impaired patients are more likely to show rapid cognitive decline. ApoE alleles seem not to modify the velocity of clinical progression of dementia, or at most could have a very small effect. No inference can be made for all the other variables analysed.

CONCLUSIONS

There are many studies on rapid cognitive decline. Results are heterogeneous and often contradictory. No reliable conclusions about factors that may be associated with rapid cognitive decline can yet be drawn.

Apolipoprotein E genotypes associated with Alzheimer disease and concomitant stroke

BACKGROUND

The ɛ4 allele of the apolipoprotein E (APOE) gene is a well-characterized genetic risk factor for Alzheimer disease (AD). The association between stroke and a higher risk for AD has also been reported. Our study sought to determine the relationship between the APOE gene and AD and the comorbid risk of stroke.

METHODS

The subjects of this study consisted of 48 patients with AD and 48 members of a control group. All subjects were genotyped for APOE.

RESULTS

The results clearly show a significant increased risk of AD in carriers of the APOE ε3/ε4 genotype (P = .003, odds ratio [OR] = 4.1) or ε4 allele (P = .001, OR = 4.2). The risk for stroke in AD patients was also increased for carriers of the APOE ε3/ε4 genotype (P = .02, OR = 9.0) and for carriers of the APOE ε4 allele (P = .004, OR = 5.5).

CONCLUSIONS

The present study is the first to establish a relationship between APOE ε4 and concomitant AD and stroke in the Tunisian population.

History of medically treated diabetes and risk of Alzheimer disease in a nationwide case-control study

OBJECTIVE

Type 2 diabetes in midlife or late life increases the risk of Alzheimer disease (AD), and type 1 diabetes has been associated with a higher risk of detrimental cognitive outcomes, although studies from older adults are lacking. We investigated whether individuals with AD were more likely to have a history of diabetes than matched controls from the general aged population.

RESEARCH DESIGN AND METHODS

Information on reimbursed diabetes medication (including both type 1 and 2 diabetes) of all Finnish individuals with reimbursed AD medication in 2005 (n = 28,093) and their AD-free control subjects during 1972-2005 was obtained from a special reimbursement register maintained by the Social Insurance Institute of Finland.

RESULTS

The prevalence of diabetes was 11.4% in the whole study population, 10.7% (n = 3,012) among control subjects, and 12.0% (n = 3,372) among AD case subjects. People with AD were more likely to have diabetes than matched control subjects (unadjusted OR 1.14 [95% CI 1.08-1.20]), even after adjusting for cardiovascular diseases (OR 1.31 [1.22-1.41]). The associations were stronger with diabetes diagnosed at midlife (adjusted OR 1.60 [1.34-1.84] and 1.25 [1.16-1.36] for midlife and late-life diabetes, respectively).

CONCLUSIONS

Individuals with clinically verified AD are more likely to have a history of clinically verified and medically treated diabetes than the general aged population, although the difference is small.

Earlier age of dementia onset and shorter survival times in dementia patients with diabetes

Diabetes is a risk factor for dementia, but relatively little is known about the epidemiology of the association. A retrospective population study using Western Australian hospital inpatient, mental health outpatient, and death records was used to compare the age at index dementia record (proxy for onset age) and survival outcomes in dementia patients with and without preexisting diabetes (n = 25,006; diabetes, 17.3%). Inpatient records from 1970 determined diabetes history in this study population with incident dementia in years 1990-2005. Dementia onset and death occurred an average 2.2 years and 2.6 years earlier, respectively, in diabetic compared with nondiabetic patients. Age-specific mortality rates were increased in patients with diabetes. In an adjusted proportional hazard model, the death rate was increased with long-duration diabetes, particularly with early age onset dementia. In dementia diagnosed before age 65 years, those with a ≥15-year history of diabetes died almost twice as fast as those without diabetes (hazard ratio = 1.9, 95% confidence interval: 1.3, 2.9). These results suggest that, in patients with diabetes, dementia onset occurs on average 2 years early and survival outcomes are generally poorer. The effect of diabetes on onset, survival, and mortality is greatest when diabetes develops before middle age and after 15 years' diabetes duration. The impact of diabetes on dementia becomes progressively attenuated in older age groups.

Pathology and pathogenesis of vascular cognitive impairment-a critical update

Vascular cognitive impairment (VCI) [vascular cognitive disorder (VCD), vascular dementia] describes a continuum of cognitive disorders ranging from mild cognitive impairment (MCI) to dementia, in which vascular brain injury involving regions important for memory, cognition and behavior plays an important role. Clinical diagnostic criteria show moderate sensitivity (ca 50%) and variable specificity (range 64-98%). In Western clinical series, VaD is suggested in 8-10% of cognitively impaired elderly subjects. Its prevalence in autopsy series varies from 0.03 to 58%, with means of 8 to 15% (in Japan 22-35%). Major types of sporadic VaD are multi-infarct encephalopathy, small vessel and strategic infarct type dementias, subcortical arteriosclerotic leukoencephalopathy (SAE) (Binswanger), multilacunar state, mixed cortico-subcortical type, granular cortical atrophy (rare), postischemic encephalopathy, and a mixture of cerebrovascular lesions (CVLs). They result from systemic, cardiac and local large or small vessel disease (SVD); their pathogenesis is multifactorial. Hereditary forms of VaD caused by gene mutations are rare. Cognitive decline is commonly associated with widespread small ischemic vascular lesions involving subcortical brain areas (basal ganglia and hemispheral white matter). The lesions affect neuronal networks involved in cognition, memory, and behavior (thalamo-cortical, striato-subfrontal, cortico-subcortical, limbic systems). CVLs often coexist with Alzheimer-type lesions and other pathologies; 25-80% of elderly demented show mixed pathologies. The lesion pattern of "pure" VaD differs from that in mixed dementia (AD + CVLs) suggesting different pathogenesis of both phenotypes. Minor CVLs, except for severe amyloid angiopathy, appear not essential for cognitive impairment in full-blown AD, while both mild AD-type pathology and SVD may interact synergistically in promoting dementia. However, in a large percentage of non-demented elderly individuals, both AD-related and vascular brain pathologies have been reported. Despite recent suggestions for staging and grading CVLs in specific brain areas, due to the high variability of CVLs associated with cognitive impairment, no validated neuropathological criteria are currently available for VaD and mixed dementia. Further clinico-pathological studies and harmonization of neuropathological procedures are needed to validate the diagnostic criteria for VaD and mixed dementia in order to clarify the impact of CVLs and other coexistent pathologies on cognitive impairment as a basis for further successful therapeutic options.

The effects of ramipril in individuals at risk for Alzheimer's disease: results of a pilot clinical trial

Research shows that certain antihypertensives taken during midlife confer Alzheimer's disease (AD) related benefits in later life. We conducted a clinical trial to evaluate the extent to which the angiotensin converting enzyme inhibitor (ACE-I), ramipril, affects AD biomarkers including cerebrospinal fluid (CSF) amyloid-β (Aβ) levels and ACE activity, arterial function, and cognition in participants with a parental history of AD. This four month randomized, double-blind, placebo-controlled, pilot clinical trial evaluated the effects of ramipril, a blood-brain-barrier crossing ACE-I, in cognitively healthy individuals with mild, or Stage I hypertension. Fourteen participants were stratified by gender and apolipoprotein E ε4 (APOE ε4) status and randomized to receive 5 mg of ramipril or matching placebo daily. Participants were assessed at baseline and month 4 on measures of CSF Aβ(1-42) and ACE activity, arterial function, and cognition. Participants were middle-aged (mean 54 y) and highly educated (mean 15.4 y), and included 50% men and 50% APOE ε4 carriers. While results did not show a treatment effect on CSF Aβ(1-42) (p = 0.836), data revealed that ramipril can inhibit CSF ACE activity (p = 0.009) and improve blood pressure, however, there were no differences between groups in arterial function or cognition. In this study, ramipril therapy inhibited CSF ACE activity and improved blood pressure, but did not influence CSF Aβ1-42. While larger trials are needed to confirm our CSF Aβ results, it is possible that prior research reporting benefits of ACE-I during midlife may be attributed to alternative mechanisms including improvements in cerebral blood flow or the prevention of angiotensin II-mediated inhibition of acetylcholine.

Cerebrovascular protection of β-asarone in Alzheimer's disease rats: a behavioral, cerebral blood flow, biochemical and genic study

AIM OF THE STUDY

Recent studies have suggested that β-asarone have neuroprotective and cardiovascular protective effects in animal model. However, the influence of β-asarone on cerebrovascular system has not been explored so far. Therefore, present study was designed to determine whether repeated exposures to β-asarone resulted in positive effects on cerebrovascular function in AD rats.

MATERIALS AND METHODS

Alzheimer's disease induced rats was established by injecting both D-galactose (D-gal) and aluminum chloride (AlCl(3)) into abdominal cavity for 42 days. After injection of AlCl(3) and D-gal or saline for 28 days, the rats were treated with volume-matched vehicle or β-asarone (25mg/kg, 50mg/kg or 100mg/kg, i.h.) or Nimodipine (40mg/kg, i.g) once daily for consecutive 14 days, respectively. Behavioral responses of animals were assessed in a Morris water maze. CBF was measured by laser Doppler flowmetry. At the end of this period all rats were sacrificed, lactic acid, pyruvic acid content, Na+K+ATPase activity were determined in brain tissue homogenate to estimate the brain biochemical changes and mRNA expression of ET-1, eNOS and APP was measured with real-time RT-PCR method.

RESULTS

The spatial navigation task latencies, the times through platform zone and the time for the first through platform zone in the target quadrant in probe task, rCBF of right parietal lobe, the contents of lactic acid, pyruvic acid, and the activity of Na-K-ATP of cortex, and ET-1 and eNOS mRNA expression in hippocampus of AG rats were different from those of BG, P<0.05; The level of APP mRNA expression in model control group rats was higher than that in BG, though there was not a statistically significant difference, P>0.05; Compared with AG, HG rats spatial navigation task latencies were shorter, in probe task the times through platform zone in the target quadrant were bigger, rCBF and blood cell concentration of right parietal lobe were higher, the contents of pyruvic acid was lower, the activity of Na-K-ATP was higher, and ET-1 mRNA expression in hippocampus was lower, P<0.05; The level of eNOS and APP mRNA expression in HG rats was lower than that in AG, though there was not a statistically significant difference, P>0.05;

CONCLUSION

The present results suggested that β-asarone may be useful in memory impairment due to its cerebrovascular protection in AD rats and may develop as a therapeutic drug for treatment of AD patients.

Review of cerebral microangiopathy and Alzheimer's disease: relation between white matter hyperintensities and microbleeds

Although Alzheimer's disease (AD) is basically considered to be a neurodegenerative disorder, cerebrovascular disease is also involved. The role of vascular risk factors and vascular disease in the progression of AD remains incompletely understood. With the development of brain MRI, it is now possible to detect small-vessel disease, whose prevalence and severity increase with age. The first types of small-vessel disease to be described were white matter hyperintensities (WMHs). More recently, small areas of signal loss on T(2)*-weighted images, also called microbleeds (MBs), have been reported. Cerebral MBs are focal deposits of hemosiderin that indicate prior microhemorrhages around small vessels, related to either ruptured atherosclerotic microvessels or amyloid angiopathy. Consequently, using brain MRI for the detection of microangiopathy may prove useful to improve our understanding of the impact of the vascular burden in AD pathology. The relationship between microangiopathy and the clinical course of AD or the conversion of mild cognitive impairment to AD remains questionable in terms of cognitive or affective symptoms, particularly if we consider MBs.

Diabetes mellitus as a modulator of functional impairment and decline in Alzheimer's disease. The Real.FR cohort

AIMS

To determine whether diabetes mellitus influences functional status in patients with Alzheimer's disease.

METHODS

We studied 608 community-dwelling patients with Alzheimer's disease from a prospective multicenter cohort. Diabetes was assessed at baseline. Functional status was assessed twice yearly with the Activities of Daily Living scale. Each patient had a baseline functional disability if their Activities of Daily Living score was < 6. Progression of functional disability was defined by a decreased Activities of Daily Living score over 4 years of follow-up visits.

RESULTS

At baseline, diabetes was present in 63 participants (10.4%) and, compared with those without diabetes, was associated with functional impairment [age- and sex-adjusted OR = 2.73 (95% CI 1.41-5.28)]. After controlling for confounders, the association remained significant [OR = 2.04 (95% CI 1.02-4.11)]. Follow-up demonstrated a significant interaction between duration of Alzheimer's disease and diabetes, which was associated with progression of functional impairment in patients who had been diagnosed with Alzheimer's disease for less than 1 year [age- and sex-adjusted hazard ratio = 1.52 (95% CI 1.01-2.30), P = 0.048], but not in those who had been diagnosed with Alzheimer's disease for more than 1 year [age- and sex-adjusted hazard ratio = 0.78 (95% CI 0.47-1.28), P = 0.32]. Abnormal one-leg balance, polymedication and obesity seem to be important factors explaining the association between diabetes and functional status.

CONCLUSIONS

At baseline, the presence of diabetes significantly increases the risk of functional disability in patients with Alzheimer's disease; our longitudinal data confirm that in patients with a recent diagnosis of Alzheimer's disease (but not in those who have had Alzheimer's disease for longer than 1 year), diabetes continues to worsen functional status.

Mild cognitive impairment: statistical models of transition using longitudinal clinical data

Mild cognitive impairment (MCI) refers to the clinical state between normal cognition and probable Alzheimer's disease (AD), but persons diagnosed with MCI may progress to non-AD forms of dementia, remain MCI until death, or recover to normal cognition. Risk factors for these various clinical changes, which we term "transitions," may provide targets for therapeutic interventions. Therefore, it is useful to develop new approaches to assess risk factors for these transitions. Markov models have been used to investigate the transient nature of MCI represented by amnestic single-domain and mixed MCI states, where mixed MCI comprised all other MCI subtypes based on cognitive assessments. The purpose of this study is to expand this risk model by including a clinically determined MCI state as an outcome. Analyses show that several common risk factors play different roles in affecting transitions to MCI and dementia. Notably, APOE-4 increases the risk of transition to clinical MCI but does not affect the risk for a final transition to dementia, and baseline hypertension decreases the risk of transition to dementia from clinical MCI.

Interaction between vascular factors and the APOE ε4 allele in predicting rate of progression in Alzheimer's disease

Vascular factors have been shown to affect the rate of Alzheimer's disease (AD) progression. However, the effect of the APOE ε4 allele on rate of progression has been ambiguous. Little research to date has examined an interaction between vascular factors and the APOE ε4 allele in predicting decline among AD patients. 216 participants with incident AD from a population of elderly persons in Cache County, Utah, were followed for a mean of 3.3 years and 4.2 follow-up visits. A history of vascular risk factors and conditions and anti-hypertensive use was assessed at the diagnostic visit. Linear mixed effects models tested interactions between the vascular factors, APOE ε4, and time as predictors of clinical progression on the Mini-Mental State Exam (MMSE) and Clinical Dementia Rating-Sum of Boxes (CDR-SB). Multiple comparisons were corrected using the Holm-Bonferroni method. There was a 3-way interaction between stroke, APOE ε4 and time in predicting MMSE decline (LR χ² = 10.32, 2 df, p = 0.006). For the CDR-SB, there were 3-way interactions between the APOE ε4, time and either myocardial infarction (LR χ² = 17.83, 2 df, p = 0.0001) or stroke (LR χ² = 11.48, 2 df, p = 0.003. Results suggest a complex relationship between the APOE ε4 and vascular factors in predicting cognitive and functional progression. Among individuals with a history of stroke or myocardial infarction at baseline, progression of AD is influenced by APOE ε4 carrier status and varies by time after AD diagnosis.