Epidemiology of dementias and Alzheimer's disease

Age-related epigenetic changes in hippocampal subregions of four animal models of Alzheimer's disease

Both aging and Alzheimer's disease (AD) are associated with widespread epigenetic changes, with most evidence suggesting global hypomethylation in AD. It is, however, unclear how these age-related epigenetic changes are linked to molecular aberrations as expressed in animal models of AD. Here, we investigated age-related changes of epigenetic markers of DNA methylation and hydroxymethylation in a range of animal models of AD, and their correlations with amyloid plaque load. Three transgenic mouse models, including the J20, APP/PS1dE9 and 3xTg-AD models, as well as Caribbean vervets (a non-transgenic non-human primate model of AD) were investigated. In the J20 mouse model, an age-related decrease in DNA methylation was found in the dentate gyrus (DG) and a decrease in the ratio between DNA methylation and hydroxymethylation was found in the DG and cornu ammonis (CA) 3. In the 3xTg-AD mice, an age-related increase in DNA methylation was found in the DG and CA1-2. No significant age-related alterations were found in the APP/PS1dE9 mice and non-human primate model. In the J20 model, hippocampal plaque load showed a significant negative correlation with DNA methylation in the DG, and with the ratio a negative correlation in the DG and CA3. For the APP/PS1dE9 model a negative correlation between the ratio and plaque load was observed in the CA3, as well as a negative correlation between DNA methyltransferase 3A (DNMT3A) levels and plaque load in the DG and CA3. Thus, only the J20 model showed an age-related reduction in global DNA methylation, while DNA hypermethylation was observed in the 3xTg-AD model. Given these differences between animal models, future studies are needed to further elucidate the contribution of different AD-related genetic variation to age-related epigenetic changes.

Anodal Transcranial Direct Current Stimulation Promotes Frontal Compensatory Mechanisms in Healthy Elderly Subjects

Recent studies have demonstrated that transcranial direct current stimulation (tDCS) is potentially useful to improve working memory. In the present study, young and elderly subjects performed a working memory task (n-back task) during an electroencephalogram recording before and after receiving anodal, cathodal, and sham tDCS over the left dorsolateral prefrontal cortex (DLPFC). We investigated modulations of behavioral performance and electrophysiological correlates of working memory processes (frontal and parietal P300 event-related potentials). A strong tendency to modulated working memory performance was observed after the application of tDCS. In detail, young, but not elderly, subjects benefited from additional practice in the absence of real tDCS, as indicated by their more accurate responses after sham tDCS. The cathodal tDCS had no effect in any group of participants. Importantly, anodal tDCS improved accuracy in elderly. Moreover, increased accuracy after anodal tDCS was correlated with a larger frontal P300 amplitude. These findings suggest that, in elderly subjects, improved working memory after anodal tDCS applied over the left DLPFC may be related to the promotion of frontal compensatory mechanisms, which are related to attentional processes.

Transgender Medicare Beneficiaries and Chronic Conditions: Exploring Fee-for-Service Claims Data

PURPOSE

Data on the health and well-being of the transgender population are limited. However, using claims data we can identify transgender Medicare beneficiaries (TMBs) with high confidence. We seek to describe the TMB population and provide comparisons of chronic disease burden between TMBs and cisgender Medicare beneficiaries (CMBs), thus laying a foundation for national level TMB health disparity research.

METHODS

Using a previously validated claims algorithm based on ICD-9-CM codes relating to transsexualism and gender identity disorder, we identified a cohort of TMBs using Medicare Fee-for-Service (FFS) claims data. We then describe the demographic characteristics and chronic disease burden of TMBs (N = 7454) and CMBs (N = 39,136,229).

RESULTS

Compared to CMBs, a greater observed proportion of TMBs are young (under age 65) and Black, although these differences vary by entitlement. Regardless of entitlement, TMBs have more chronic conditions than CMBs, and more TMBs have been diagnosed with asthma, autism spectrum disorder, chronic obstructive pulmonary disease, depression, hepatitis, HIV, schizophrenia, and substance use disorders. TMBs also have higher observed rates of potentially disabling mental health and neurological/chronic pain conditions, as well as obesity and other liver conditions (nonhepatitis), compared to CMBs.

CONCLUSION

This is the first systematic look at chronic disease burden in the transgender population using Medicare FFS claims data. We found that TMBs experience multiple chronic conditions at higher rates than CMBs, regardless of Medicare entitlement. TMBs under age 65 show an already heavy chronic disease burden which will only be exacerbated with age.

Clinical Spectrum, Risk Factors, and Behavioral Abnormalities among Dementia Subtypes in a North Indian Population: A Hospital-Based Study

Background

As variability in the clinical profile of dementia subtypes had been reported with regional differences across the world, we conducted a retrospective hospital-based study in a North Indian population.

Methods

We retrieved patient records from 2007 to 2014 for details of clinical evaluation, diagnosis, neuroimaging, biochemical investigations, and follow-up of 1,876 patients with dementia (PwD), and the data were analyzed using descriptive statistics.

Results

Of the total PwD, Alzheimer disease (AD) accounted for 30% followed by vascular dementia (VaD) 26%, mixed dementia (MD) 21%, Parkinson-related dementia 11%, frontotemporal dementia (FTD) 7%, and infective dementia 5%. Of all PwD excluding the infective group (n = 1,777), 63% were men, 39% were from rural areas, 87% had behavioral abnormalities along with cognitive deficits, and 73% had impaired ADLs. Among dementia subtypes, a positive family history, cardiovascular and metabolic risk factors, and behavioral abnormalities were found to be distributed. However, there existed a predominance of specific behavioral pattern in each subtype. The mean duration of follow-up varied from 2.9 ± 2.3 (VaD) to 3.6 ± 2.1 (AD) and greater than 30% were found to be stable on treatment (except in dementia with Lewy body).

Conclusions

This large hospital-based study provides a distribution pattern and clinical spectrum of dementia subtypes in a North Indian population.

Neuropsychiatric symptoms as risk factors of dementia in a Mexican population: A 10/66 Dementia Research Group study

Introduction

Cognitive and/or memory impairment are the main clinical markers currently used to identify subjects at risk of developing dementia. This study aimed to explore the relationship between the presence of neuropsychiatric symptoms and dementia incidence.

Methods

We analyzed the association between neuropsychiatric symptoms and incident dementia in a cohort of 1355 Mexican older adults from the general population over 3 years of follow-up, modeling cumulative incidence ratios using Poisson models.

Results

Five neuropsychiatric symptoms were associated with incident dementia: delusions, hallucinations, anxiety, aberrant motor behavior, and depression. The simultaneous presence of two symptoms had a relative risk, adjusted for mild cognitive impairment, diabetes, indicators of cognitive function, and sociodemographic factors, of 1.9 (95% confidence interval, 1.2–2.9), whereas the presence of three to five, similarly adjusted, had a relative risk of 3.0 (95% confidence interval, 1.9–4.8).

Discussion

Neuropsychiatric symptoms are common in predementia states and may independently contribute as risk factors for developing dementia.

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Not only cognitive impairment and cognitive features are useful in identifying older adults at risk for developing dementia.

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Of the 12 neuropsychiatric symptoms evaluated, 5 were associated with incident dementia (delusions, hallucinations, depression, anxiety, and aberrant motor behavior) in a 3-year follow-up.

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The evaluation of neuropsychiatric symptoms, along with other simple, practical, and inexpensive features, may be useful in identifying subjects at risk of dementia in community health settings and by general practitioners.

Alzheimer's disease and metabolic syndrome: A link from oxidative stress and inflammation to neurodegeneration

Alzheimer's disease (AD) is the most common cause of dementia and one of the most important causes of morbidity and mortality among the aging population. AD diagnosis is made post-mortem, and the two pathologic hallmarks, particularly evident in the end stages of the illness, are amyloid plaques and neurofibrillary tangles. Currently, there is no curative treatment for AD. Additionally, there is a strong relation between oxidative stress, metabolic syndrome, and AD. The high levels of circulating lipids and glucose imbalances amplify lipid peroxidation that gradually diminishes the antioxidant systems, causing high levels of oxidative metabolism that affects cell structure, leading to neuronal damage. Accumulating evidence suggests that AD is closely related to a dysfunction of both insulin signaling and glucose metabolism in the brain, leading to an insulin-resistant brain state. Four drugs are currently used for this pathology: Three FDA-approved cholinesterase inhibitors and one NMDA receptor antagonist. However, wide varieties of antioxidants are promissory to delay or prevent the symptoms of AD and may help in treating the disease. Therefore, therapeutic efforts to achieve attenuation of oxidative stress could be beneficial in AD treatment, attenuating Aβ-induced neurotoxicity and improve neurological outcomes in AD. The term inflammaging characterizes a widely accepted paradigm that aging is accompanied by a low-grade chronic up-regulation of certain pro-inflammatory responses in the absence of overt infection, and is a highly significant risk factor for both morbidity and mortality in the elderly.

Real Time Monitoring of Children, and Adults with Mental Disabilities Using a Low-Cost Non-Invasive Electronic Device

There are a growing number of small children-as well as adults-with mental disabilities (including elderly citizens with Alzheimer's disease or other forms of age-related dementia) that are getting lost in rural and urban areas for various reasons. Establishing their location within the first 72 h is crucial because lost people are exposed to all kinds of adverse conditions and in the case of the elderly, this is further aggravated if prescribed medication is needed. Herein we describe a non-invasive, low-cost electronic device that operates constantly, keeping track of time, the geographical location and the identification of the subject using it. The prototype was made using commercial low-cost electronic components. This electronic device shows high connectivity in open and closed areas and identifies the geographical location of a lost subject. We freely provide the software and technical diagrams of the prototypes.

Nationwide Case-Control Study Examining the Association between Tamoxifen Use and Alzheimer's Disease in Aged Women with Breast Cancer in Taiwan

Background and Objectives: Little is known about the association between tamoxifen use and Alzheimer's disease in women with breast cancer. The study aimed to explore the association between tamoxifen use and Alzheimer's disease in aged women with breast cancer in Taiwan. Methods: We conducted a retrospective nationwide case-control study using the database of the Taiwan National Health Insurance Program. Totally, 173 female subjects with breast cancer aged ≥ 65 years with newly diagnosed Alzheimer's disease from 2000 to 2011 were identified as the cases. Additionally, 684 female subjects with breast cancer aged ≥ 65 years without any type of dementia were selected as the matched controls. The cases and the matched controls were matched with age and comorbidities. Ever use of tamoxifen was defined as subjects who had at least a prescription for tamoxifen before the index date. Never use of tamoxifen was defined as subjects who never had a prescription for tamoxifen before the index date. We used the logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of Alzheimer's disease associated with tamoxifen use. Results: The OR of Alzheimer's disease was 3.09 for subjects with ever use of tamoxifen (95% CI 2.10, 4.55), compared with never use. The OR of Alzheimer's disease was 1.23 for subjects with increasing cumulative duration of tamoxifen use for every 1 year (95% CI 1.13, 1.34), compared with never use. Conclusion: The increased odds of Alzheimer's disease associated with tamoxifen use may be due to the survival effect, not the toxic effect. That is, the longer the tamoxifen use, the longer the patients survive, and the greater the likelihood that she may have a chance to develop Alzheimer's disease.

Anticholinergic Drug Use and Risk to Cognitive Performance in Older Adults with Questionable Cognitive Impairment: A Cross-Sectional Analysis

BACKGROUND

Age-associated decline in central cholinergic activity makes older adults susceptible to the harmful effects of anticholinergic (AC) medications; however, there is an inadequate understanding of the association and possible effects of AC drugs on cognition. This cross-sectional study examines the associations of AC medications on cognition among older adults with questionable cognitive impairment (QCI).

METHODS

For this cross-sectional study, we used a multicenter database of community-dwelling older adults (N = 7351) aged 60+ years with QCI, from September 2005 to March 2014, as the baseline data. The Anticholinergic Drug Scale was used to categorize AC drug load into no, low, or moderate/high groups. Individuals with a Clinical Dementia Rating-Sum of Boxes score between 0.5 and 2.5 were identified as having QCI, while cognitive performance was evaluated using the Neuropsychological Test Battery. The mean z-scores of neuropsychological tests were grouped into a global cognition score.

RESULTS

Participants who took AC medications were older, largely female, and had a higher prevalence of incontinence than those without AC exposure. Global cognition was significantly greater in the moderate/high-AC group than the no-AC group (-0.23 ± 0.53 vs. -0.32 ± 0.53). Multivariable linear regression showed that the global cognition score among the low- and moderate/high-AC groups, compared with the no-AC group, was 0.064 higher (p = 0.006 and p = 0.12, respectively).

CONCLUSIONS

This cross-sectional study indicates that older adults with QCI who were exposed to AC medications might have higher global cognitive scores than those without AC exposure. The observed associations indicate that older adults might experience some beneficial cognitive effects from AC drugs, possibly due to the therapeutic effects of these medications in controlling comorbidities, thus outweighing their adverse effects on cognition.

LX2343 alleviates cognitive impairments in AD model rats by inhibiting oxidative stress-induced neuronal apoptosis and tauopathy

Alzheimer's disease (AD) is a progressive neurodegenerative disease leading to the irreversible loss of brain neurons and cognitive abilities, and the vicious interplay between oxidative stress (OS) and tauopathy is believed to be one of the major players in AD development. Here, we demonstrated the capability of the small molecule N-(1,3-benzodioxol-5-yl)-2-[5-chloro-2-methoxy(phenylsulfonyl)anilino]acetamide (LX2343) to ameliorate the cognitive dysfunction of AD model rats by inhibiting OS-induced neuronal apoptosis and tauopathy. Streptozotocin (STZ) was used to induce OS in neuronal cells in vitro and in AD model rats that were made by intracerebroventricular injection of STZ (3 mg/kg, bilaterally), and Morris water maze test was used to evaluate the cognitive dysfunction in ICV-STZ rats. Treatment with LX2343 (5-20 μmol/L) significantly attenuated STZ-induced apoptosis in SH-SY5Y cells and mouse primary cortical neurons by alleviating OS and inhibiting the JNK/p38 and pro-apoptotic pathways. LX2343 was able to restore the integrity of mitochondrial function and morphology, increase ATP biosynthesis, and reduce ROS accumulation in the neuronal cells. In addition, LX2343 was found to be a non-ATP competitive GSK-3β inhibitor with IC₅₀ of 1.84±0.07 μmol/L, and it potently inhibited tau hyperphosphorylation in the neuronal cells. In ICV-STZ rats, administration of LX2343 (7, 21 mg·kg^-1·d^-1, ip, for 5 weeks) efficiently improved their cognitive deficits. LX2343 ameliorates the cognitive dysfunction in the AD model rats by suppressing OS-induced neuronal apoptosis and tauopathy, thus highlighting the potential of LX2343 for the treatment of AD.

Improved Neuroprotection Provided by Drug Combination in Neurons Exposed to Cell-Derived Soluble Amyloid-β Peptide

Oligomeric amyloid-β (Aβ) peptide contributes to impaired synaptic connections and neurodegenerative processes, and as such, represents a primary therapeutic target for Alzheimer's disease (AD)-modifying approaches. However, the lack of efficacy of drugs that inhibit production of Aβ demonstrates the need for a better characterization of its toxic effects, both on synaptic and neuronal function. Here, we used conditioned medium obtained from recombinant HEK-AβPP cells expressing the human amyloid-β protein precursor (Aβ-CM), to investigate Aβ-induced neurotoxic and synaptotoxic effects. Characterization of Aβ-CM revealed that it contained picomolar amounts of cell-secreted Aβ in its soluble form. Incubation of primary cortical neurons with Aβ-CM led to significant decreases in synaptic protein levels as compared to controls. This effect was no longer observed in neurons incubated with conditioned medium obtained from HEK-AβPP cells grown in presence of the γ-secretase inhibitor, Semagacestat or LY450139 (LY-CM). However, neurotoxic and pro-apoptotic effects of Aβ-CM were only partially prevented using LY-CM, which could be explained by other deleterious compounds related to chronic oxidative stress that were released by HEK-AβPP cells. Indeed, full neuroprotection was observed in cells exposed to LY-CM by additional treatment with the antioxidant resveratrol, or with the pluripotent n-3 polyunsaturated fatty acid docosahexaenoic acid. Inhibition of Aβ production appeared necessary but insufficient to prevent neurodegenerative effects associated with AD due to other neurotoxic compounds that could exert additional deleterious effects on neuronal function and survival. Therefore, association of various types of protective agents needs to be considered when developing strategies for AD treatment.

Association between polymorphisms in the promoter region of the apolipoprotein E (APOE) gene and Alzheimer's disease: A meta-analysis

Several studies have evaluated the role of polymorphisms in the promoter region of APOE gene that encodes apolipoprotein E (APOE) and the susceptibility to Alzheimer's disease (AD). The aim of this literature review and meta-analysis was to investigate the relationship between the APOE promoter region single nucleotide polymorphisms (SNPs) (rs449647, -491A/T; rs769446, -427T/C and rs405509 -219T/G) and the risk of developing AD. Eligible controlled studies published up to November 2016 were retrieved from main online scientific and medical databases. Odds ratio (OR) and 95 % confidence interval (CI) were used to calculate the strength of the relationship. A total of 23 publications (19 for rs449647, ten for rs769446 and ten for rs405509) were retrieved that included 5,703 patients with AD and 5,692 controls. The C allele of the rs769446 variant of the promoter region of APOE gene was significantly associated with an increase of risk of AD (OR = 1.271, 95 % CI = 1.114-1.449, P < 0.0001), while other genetic models of this variant were not related with susceptibility to AD. Rs449647 and rs405509 polymorphisms of APOE gene were not associated with an increase of risk of AD. The findings of this literature review and meta-analysis have shown that rs769446 polymorphism in the promoter region of APOE gene could be a risk factor for AD. Future large-scale studies on the role of polymorphisms in the promoter region of APOE gene in AD are still awaited.

Transcranial direct current stimulation for depression in Alzheimer's disease: study protocol for a randomized controlled trial

Background

Patients with Alzheimer’s disease frequently elicit neuropsychiatric symptoms as well as cognitive deficits. Above all, depression is one of the most common neuropsychiatric symptoms in Alzheimer’s disease but antidepressant drugs have not shown significant beneficial effects on it. Moreover, electroconvulsive therapy has not ensured its safety for potential severe adverse events although it does show beneficial clinical effect. Transcranial direct current stimulation can be the safe alternative of neuromodulation, which applies weak direct electrical current to the brain. Although transcranial direct current stimulation has plausible evidence for its effect on depression in young adult patients, no study has explored it in older subjects with depression in Alzheimer’s disease. Therefore, we present a study protocol designed to evaluate the safety and clinical effect of transcranial direct current stimulation on depression in Alzheimer’s disease in subjects aged over 65 years.

Method

This is a two-arm, parallel-design, randomized controlled trial, in which patients and assessors will be blinded. Subjects will be randomized to either an active or a sham transcranial direct current stimulation group. Participants in both groups will be evaluated at baseline, immediately, and 2 weeks after the intervention.

Discussion

This study investigates the safety and effect of transcranial direct current stimulation that may bring a significant impact on both depression and cognition in patients with Alzheimer’s disease, and may be useful to enhance their quality of life.

Trial registration

ClinicalTrials.gov, NCT02351388. Registered on 27 January 2015. Last updated on 30 May 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2019-z) contains supplementary material, which is available to authorized users.

Long-term use of proton pump inhibitors among community-dwelling persons with and without Alzheimer's disease

PURPOSE

The aim of this study is to determine the prevalence of use and long-term use (≥180 days) of proton pump inhibitors (PPIs) and associated factors among community-dwellers with and without Alzheimer's disease (AD).

METHODS

MEDALZ cohort encompassed all persons who received a verified diagnosis of AD in Finland during the years 2005-2011 and their age-, sex-, and region of residence-matched comparison persons, including 69,353 persons with and 69,353 persons without AD. Data was derived from several Finnish administrative registers. A mathematical modelling method, PRE2DUP, was used for converting dispensing data to drug use periods (when regular PPI use started and ended). Morbid conditions and concomitant drugs associated with use and long-term use of PPIs were assessed with logistic regression models.

RESULTS

Use of PPIs was more common among comparison persons than persons with AD (39.0 and 35.8%, respectively, p < 0.001), whereas long-term use of PPIs was more frequent among persons with than without AD (20.3 and 17.9%, respectively, p < 0.001). Factors related to long-term use of PPIs were female sex, history of gastrointestinal bleedings, AD, rheumatoid arthritis, cardiovascular disease, asthma/COPD and use of bisphosphonates, SSRIs and antithrombotic agents. Median follow-up time was 2.6 years among persons with AD and 3.5 years among persons without AD. Median duration of the first long-term PPI use was similar in both groups (1.4 years).

CONCLUSION

Long-term use of PPIs was common among persons with and without AD. Due to possible adverse events associated with the long-term use of PPIs, need for PPIs should be assessed regularly.

Neurodegeneration and the Circadian Clock

Despite varied etiologies and symptoms, several neurodegenerative diseases—specifically, Alzheimer’s (AD), Parkinson’s (PD), and Huntington’s diseases (HDs)—share the common feature of abnormal circadian rhythms, such as those in behavior (e.g., disrupted sleep/wake cycles), physiological processes (e.g., diminished hormone release) and biochemical activities (e.g., antioxidant production). Circadian disturbances are among the earliest symptoms of these diseases, and the molecular mechanisms of the circadian system are suspected to play a pivotal, and possibly causal, role in their natural histories. Here, we review the common circadian abnormalities observed in ADs, PDs and HDs, and summarize the evidence that the molecular circadian clockwork directly influences the course of these disease states. On the basis of this research, we explore several circadian-oriented interventions proposed as treatments for these neurological disorders.

Synaptic Impairment in Alzheimer's Disease: A Dysregulated Symphony

Alzheimer's disease (AD) is characterized by memory loss, cognitive decline, and devastating neurodegeneration, not only as a result of the extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular accumulation of tau, but also as a consequence of the dysfunction and loss of synapses. Although significant advances have been made in our understanding of the relationship of the pathological role of Aβ and tau in synapse dysfunction, several questions remain as to how Aβ and tau interdependently cause impairments in synaptic function in AD. Overall, more insight into these questions should enable researchers in this field to develop novel therapeutic targets to mitigate or delay the cognitive deficits associated with this devastating disease.

Defining Disease Modifying Therapy for Alzheimer's Disease

BACKGROUND

Disease-modifying therapies (DMTs) are urgently needed to treat the growing number of individuals with Alzheimer's disease (AD) or at immanent risk for AD. A definition of DMT is required to facilitate the process of DMT drug development.

PROCESS

This is a review of the state of the science with regard to definition and development of DMTs.

RESULTS

A DMT is as an intervention that produces an enduring change in the clinical progression of AD by interfering in the underlying pathophysiological mechanisms of the disease process that lead to cell death. Demonstration of DMT efficacy is garnered through clinical trial designs and biomarkers. Evidence of disease modification in the drug development process is based on trial designs such as staggered start and delayed withdrawal showing an enduring effect on disease course or on combined clinical outcomes and correlated biomarker evidence of an effect on the underlying pathophysiological processes of the disease. Analytic approaches such as showing change in slope of cognitive decline, increasing drug-placebo difference over time, and delay of disease milestones are not conclusive by themselves but support the presence of a disease modifying effect. Neuroprotection is a related concept whose demonstration depends on substantiating disease modification. No single type of evidence in itself is sufficient to prove disease modification - consistency, robustness, and variety of sources of data will all contribute to convincing stakeholders that an agent is a DMT.

CONCLUSION

DMT is defined by its enduring effect on processes leading to cell death. A variety of types of data can be used to support the hypothesis that disease modification has occurred.

Validation of the short version of the 10/66 dementia diagnosis in multiethnic Asian older adults in Singapore

Background

To validate the short version of the 10/66 dementia diagnosis against the standard version of the 10/66 dementia diagnosis and clinical diagnosis and examine concurrent validity with the World Health Organisation Disability Assessment schedule and care needs in a multiethnic Asian older adult population in Singapore.

Methods

Data from the Well-being of the Singapore Elderly study, a nationally representative survey of the older Singapore Resident population aged 60 years and above was used. The validity of the short version of the 10/66 dementia diagnostic criteria derived from the Community Screening Instrument for Dementia, the modified Consortium to Establish a Registry of Alzheimer’s Disease 10-word list delayed recall and the EURO-D depression screen were examined against the standard version of the 10/66 dementia diagnosis and clinician diagnosis as a gold standard. Concurrent validity was tested by examining the relationships between the short version 10/66 dementia diagnosis, disability and care needs.

Results

A total of 2373 respondents who had completed data on the short version diagnosis were included in this study. The majority (82.63%) of respondents were of Chinese descent, 9.86% were Malays, 6.12% were of Indian descent and 1.39% belonged to other ethnic group. We found the short version 10/66 dementia diagnosis showed almost perfect agreement with the standard version 10/66 dementia diagnosis (kappa = 0.90, AUC = 0.96) and substantial agreement with clinical diagnosis (kappa = 0.70, AUC = 0.87). The weighted prevalence of dementia in the population was slightly higher based on the short version diagnosis than the standard version diagnosis (10.74% vs. 10.04%). We also found that those with the short version 10/66 dementia were significantly associated with higher disability (β = 28.90, 95% CI = 23.62, 9.62) and needed care occasionally (OR =35.21, 95% CI = 18.08, 68.59) or much of the time (OR = 9.02, 95% CI = 5.21, 15.61).

Conclusions

The study found that the short version 10/66 dementia diagnosis has excellent validity to diagnose dementia in a multiethnic Asian population in Singapore. Further research is required to determine the usefulness of this diagnosis in clinical practice or institutional settings to aid early detection and intervention for dementia.

Thymol improves high-fat diet-induced cognitive deficits in mice via ameliorating brain insulin resistance and upregulating NRF2/HO-1 pathway

The impaired insulin signaling has been recognized as a common pathogenetic mechanism between diabetes and Alzheimer's disease (AD). In the progression of AD, brain is characterized by defective insulin receptor substrate-1 (IRS-1) and increased oxidative stress. Thymol, a monoterpene phenol isolated from medicinal herbs, has exhibited robust neuroprotective effects. The present study was designed to investigate the protective effect of thymol on HFD-induced cognitive deficits, and explore the possible mechanisms. C57BL/6 J mice were fed for 12 weeks with either HFD or normal diet. The mice fed with HFD were dosed with metformin (200 mg/kg) or thymol (20, 40 mg/kg) daily. It was observed that thymol treatment significantly reversed the gain of body weight and peripheral insulin resistance induced by HFD. Meanwhile, thymol improved the cognitive impairments in the Morris Water Maze (MWM) test and decreased HFD-induced Aβ deposition and tau hyperphosphorylation in the hippocampus, which may be correlated with the inhibition of hippocampal oxidative stress and inflammation. In addition, thymol down-regulated the level of P-Ser307 IRS-1, and hence enhancing the expression of P-Ser473 AKT and P-Ser9 GSK3β. We further found that the protective effects of thymol on cognitive impairments were associated with the up-regulation of nuclear respiratory factor (Nrf2)/heme oxygenase-1(HO-1) pathway. In conclusion, thymol exhibited beneficial effects on HFD-induced cognitive deficits through improving hippocampal insulin resistance, and activating Nrf2/HO-1 signaling.

Effectiveness of a 16-Week Multimodal Exercise Program on Individuals With Dementia: Study Protocol for a Multicenter Randomized Controlled Trial

BACKGROUND

The increasing prevalence of dementia in the next decades is accompanied by various societal and economic problems. Previous studies have suggested that physical activity positively affects motor and cognitive skills in individuals with dementia (IWD). However, there is insufficient evidence probably related to several methodological limitations. Moreover, to date adequate physical activity interventions specifically developed for IWD are lacking.

OBJECTIVE

This study aims to investigate the effectiveness of a multimodal exercise program (MEP) on motor and cognitive skills in IWD in a high-quality multicenter trial.

METHODS

A multicenter randomized controlled trial with baseline and postassessments will be performed. It is planned to enroll 405 participants with dementia of mild to moderate stage, aged 65 years and older. The intervention group will participate in a 16-week ritualized MEP especially developed for IWD. The effectiveness of the MEP on the primary outcomes balance, mobility, and gait will be examined using a comprehensive test battery. Secondary outcomes are strength and function of lower limbs, activities of daily living, and cognition (overall cognition, language, processing speed, learning and memory, and visual spatial cognition).

RESULTS

Enrollment for the study started in May 2015. It is planned to complete postassessments by the beginning of 2017. Results are expected to be available in the first half of 2017.

CONCLUSIONS

This study will contribute to enhancing evidence for the effects of physical activity on motor and cognitive skills in IWD. Compared to previous studies, this study is characterized by a dementia-specific intervention based on scientific knowledge, a combination of motor and cognitive tasks in the intervention, and high standards regarding methodology. Findings are highly relevant to influence the multiple motor and cognitive impairments of IWD who are often participating in limited physical activity.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00010538; https://drks-neu.uniklinik-freiburg.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00010538 (Archived by WebCite at http://www.webcitation.org/6oVGMbbMD).

Hormone therapy for prostate cancer increases the risk of Alzheimer's disease: a nationwide 4-year longitudinal cohort study

INTRODUCTION

Androgen-deprivation therapy (ADT) is recognized to be the preferred first-line treatment for advanced prostate cancer. However, the risk-benefit ratio of ADT remains poorly defined and the relationship between androgen depletion and dementia is not clear.

AIM

To investigate the risk of developing Alzheimer's disease (AD) in patients undergoing ADT for prostate cancer.

METHODS

Data from 24 360 prostate cancer patients were collected from the Longitudinal Health Insurance Database of Taiwan. In total, 15 959 patients who underwent ADT were included in the study cohort, and another 8401 patients who did not receive ADT were included as a non-ADT cohort.

RESULTS

During the average 4-year follow-up period, the incidence of AD was 2.78 per 1000 person-years in the non-ADT cohort and 5.66 per 1000 person-years in the ADT cohort. After adjusting for age and all comorbidities, the combined ADT cohort was found to be 1.84 times more likely to develop AD than the non-ADT control group (95%CI 1.33-2.55, p < 0.001).

CONCLUSIONS

The present results suggest that ADT use is associated with an increased risk of developing AD.

Decreased HHV-6 IgG in Alzheimer's Disease

Human herpesviruses have previously been implicated in the pathogenesis of Alzheimer's disease (AD) but whether they are causal, facilitating, or confounding factors is yet to be established. A total of 50 AD subjects and 52 non-demented (ND) controls were analyzed in a multiplex assay for IgG reactivity toward herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), and human herpesvirus 6 (HHV-6). The HHV-6 IgG reactivity was significantly lower in AD subjects compared to ND controls, whereas there were no differences in HSV, VZV, or CMV antibody levels between the groups. Analysis of peripheral blood mononuclear cells with a subtype-specific HHV-6 PCR revealed no signs of reactivation, as AD and ND subjects presented with comparable HHV-6 DNA levels in PBMCs, and all positive samples were of subtype B. Whether HHV-6 is a factor in AD remains to be elucidated in future studies.

Prevalence of dementia subtypes in United States Medicare fee-for-service beneficiaries, 2011-2013

INTRODUCTION

Rapid growth of the older adult population requires greater epidemiologic characterization of dementia. We developed national prevalence estimates of diagnosed dementia and subtypes in the highest risk United States (US) population.

METHODS

We analyzed Centers for Medicare & Medicaid administrative enrollment and claims data for 100% of Medicare fee-for-service beneficiaries enrolled during 2011-2013 and age ≥68 years as of December 31, 2013 (n = 21.6 million).

RESULTS

Over 3.1 million (14.4%) beneficiaries had a claim for a service and/or treatment for any dementia subtype. Dementia not otherwise specified was the most common diagnosis (present in 92.9%). The most common subtype was Alzheimer's (43.5%), followed by vascular (14.5%), Lewy body (5.4%), frontotemporal (1.0%), and alcohol induced (0.7%). The prevalence of other types of diagnosed dementia was 0.2%.

DISCUSSION

This study is the first to document concurrent prevalence of primary dementia subtypes among this US population. The findings can assist in prioritizing dementia research, clinical services, and caregiving resources.

Ischemic optic neuropathy as a model of neurodegenerative disorder: A review of pathogenic mechanism of axonal degeneration and the role of neuroprotection

Optic neuropathy is a neurodegenerative disease which involves optic nerve injury. It is caused by acute or intermittent insults leading to visual dysfunction. There are number of factors, responsible for optic neuropathy, and the optic nerve axon is affected in all type which causes the loss of retinal ganglion cells. In this review we will highlight various mechanisms involved in the cell loss cascades during axonal degeneration as well as ischemic optic neuropathy. These mechanisms include oxidative stress, excitotoxicity, angiogenesis, neuroinflammation and apoptosis following retinal ischemia. We will also discuss the effect of neuroprotective agents in attenuation of the negative effect of factors involve in the disease occurrence and progression.

Oleanolic Acid Inhibiting the Differentiation of Neural Stem Cells into Astrocyte by Down-Regulating JAK/STAT Signaling Pathway

To investigate the effect of oleanolic acid (OA) on the differentiation of neural stem cells (NSCs) induced by A[Formula: see text] via regulating the JAK/STAT signaling pathway, a neurotoxicity cell model involving the induction of NSCs by soluble A[Formula: see text] (5 [Formula: see text]M) was used. The WST-1 method and immunofluorescence tests were used respectively to detect the activity of cell model and the expression of GFAP[Formula: see text]/DAPI and Tubulin[Formula: see text]/DAPI. Western blotting and real-time PCR analyses were used to observe the effects of OA on NSCs differentiation by examining key targets of the JAK/STAT signal transduction pathway. Compared with normal NSCs, A[Formula: see text]-induced NSCs had down-regulated expression of Ngn1 and up-regulated STAT3 expression and phosphorylation, and inhibited neuronal differentiation. OA treatment effectively inhibited the A[Formula: see text]-induced activation of JAK/STAT signaling, with a significant increase in Ngn1 expression and a significant decrease in p-STAT3/STAT3. These results indicate that OA could inhibit the excessive differentiation of NSCs into astrocytes by down-regulating JAK/STAT signaling which might retard the progress of AD.

Angiotensin-converting enzyme insertion/deletion polymorphism and the longitudinal progression of Alzheimer's disease

AIM

The angiotensin-converting enzyme gene (ACE) insertion (I)/deletion (D) polymorphism is considered a biologically plausible gene for Alzheimer's disease (AD) in cross-sectional studies. The present study aimed to investigate the longitudinal effect of ACE I/D polymorphism on AD progression.

METHODS

This 3-year observational study investigated the longitudinal effect of ACE I/D polymorphism on AD progression. Clinically diagnosed AD patients with a clinical dementia rating (CDR) of 0.5 or 1 were enrolled in the study. The Mini-Mental State Examination (MMSE), Cognitive Assessment Screening Instrument (CASI) and the CDR scale were carried out for all patients on the date of the initial interview and 36 ± 6 months after the initial evaluation.

RESULTS

A total of 177 patients with sporadic AD were enrolled in this study. Among all patients, those with the I/I genotype showed a higher risk of CDR deterioration (I/I versus I/D + D/D: adjusted OR 2.103, 95% CI 1.113-3.972; adjusted P = 0.022). Among 74 AD patients without hypertension, those with the I/I genotype showed significantly greater differences in the MMSE, CASI and the CDR-sum of box scores, and a higher risk of CDR deterioration (I/I versus I/D + D/D: adjusted OR 3.255, 95% CI 1.099-9.639; adjusted P = 0.033) after adjustment for possible confounders during the 3-year follow up.

CONCLUSIONS

Patients with AD who were homozygous for the I allele presented with a more rapid AD deterioration than did those who had other ACE genotypes, particularly those patients without hypertension. Geriatr Gerontol Int 2017; 17: 1544-1550.

Hippocampal Volumetry as a Biomarker for Dementia in People with Low Education

Background/Aims

To evaluate the relationship between hippocampal volume and cognitive decline in patients with dementia due to probable Alzheimer's disease (AD), amnestic mild cognitive impairment (aMCI) and education, and the possible relationship between cognitive reserve and education in this population.

Methods

From February 2013 to October 2015, 76 patients (25 men, 51 women) were classified according to the NIA-AA diagnostic criteria. We used two 3.0-tesla MRI scanners and performed manual hippocampal volumetry.

Results

Twenty-six patients were found to have AD, 20 aMCI and 30 had normal aging (NA). The mean normalized hippocampal volume in age-, sex- and education (years)-matched subjects was 2.38 ± 0.51 cm³ in AD (p < 0.001), 2.91 ± 0.78 cm³ in aMCI (p = 0.019) and 3.07 ± 0.76 cm³ in NA.

Conclusion

Psychometric test (MMSE and MoCA) scores had a good to strong positive correlation with statistically significant differences in the entire population and healthy subjects but not among dementia patients and lower educational level groups. The patients with low education had greater hippocampal volumes, which is in line with the cognitive reserve theory; lower-educated individuals can tolerate less neuropathology and will thus show less atrophy at a similar level of cognitive performance than higher-educated subjects.

Alzheimer's drug-development pipeline: 2016

Background

Alzheimer's disease (AD) is growing in frequency and new therapies are urgently needed.

Methods

We assessed clinicaltrials.gov (accessed 1-4-2016) to determine the number and characteristics of trials in phase I, phase II, and phase III for treatment of AD.

Results

There are currently 24 agents in 36 trials in phase III of AD drug development. Seven of these 24 agents are symptomatic cognitive-enhancing compounds, and 17 are disease-modifying treatments (DMTs). Most DMTs address amyloid-related targets (76%). There are 45 agents in phase II being assessed in 52 clinical trials. Phase II trials include 30 DMTs, with 26 small molecules and 4 immunotherapies. There are 24 agents in the first phase of AD drug development.

Discussion

Amyloid is the principal target of late-stage development programs. There are relatively few agents in clinical trials for AD suggesting a need to amplify the drug discovery ecosystem.

Interprofessional education in the care of people diagnosed with dementia and their carers: a systematic review

OBJECTIVES

This systematic review is linked to the multifaceted social, economic and personal challenges of dementia and the international recognition of the value of interprofessional education (IPE) and its influence on health and social care outcomes. This review therefore aimed to identify, describe and evaluate the impact of IPE interventions on health and social care practitioners (prequalification and postqualification) understanding of dementia, the quality of care for people with dementia and support for their carers.

METHODS

Following PRISMA guidelines, 9 databases were searched (MEDLINE, EMBASE, The Cochrane Library, PsycINFO, CINAHL Plus, Applied Social Sciences Index and Abstracts, Healthcare Management Information Consortium, ERIC and British Education Index). Narrative analysis of the findings was undertaken.

DESIGN

Systematic review.

RESULTS

6 studies meeting the inclusion criteria were identified. The majority of studies were conducted in North America. Participants in 4 studies were health and social care practitioners caring for people with dementia, whereas the remaining studies focused on training graduate or undergraduate students. Diverse IPE activities with varying content, delivery mode and duration were reported. Although some studies reported more positive attitudes to interprofessional working as a result of the interventions, none reported benefits to patients or carers. The quality of the included studies varied. Overall, the evidence for the reported outcomes was considered weak.

CONCLUSIONS

This review identified 6 studies describing IPE interventions intended to improve collaborative knowledge, skills, interprofessional practice and organisational awareness of dementia and dementia care. The small number of studies, their varied nature, scope and settings combined with poor quality of evidence limits our understanding of the effectiveness of IPE on the care and support of people with dementia and their carers. Further research is required to develop the evidence base and provide robust studies to inform IPE development.

TRIAL REGISTRATION NUMBER

CRD42014015075.

Active Vaccines for Alzheimer Disease Treatment

INTRODUCTION

Vaccination against peptides specific to Alzheimer disease may generate an immune response that could help inhibit disease and symptom progression.

METHODS

PubMed and Scopus were searched for clinical trial articles, review articles, and preclinical studies relevant to the field of active Alzheimer disease vaccines and raw searches yielded articles ranging from 2016 to 1973. ClinicalTrials.gov was searched for active Alzheimer disease vaccine trials. Manual research and cross-referencing from reviews and original articles was performed.

RESULTS

First generation Aβ42 phase 2a trial in patients with mild to moderate Alzheimer disease resulted in cases of meningoencephalitis in 6% of patients, so next generation vaccines are working to target more specific epitopes to induce a more controlled immune response. Difficulty in developing these vaccines resides in striking a balance between providing a vaccine that induces enough of an immune response to actually clear protein sustainably but not so much of a response that results in excess immune activation and possibly adverse effects such as meningoencephalitis.

CONCLUSIONS

Although much work still needs to be done in the field to make this a practical possibility, the enticing allure of being able to treat or even prevent the extraordinarily impactful disease that is Alzheimer disease makes the idea of active vaccination for Alzheimer disease very appealing and something worth striving toward.

Turning on the Light Within: Subcortical Nuclei of the Isodentritic Core and their Role in Alzheimer's Disease Pathogenesis

Pharmacological interventions in Alzheimer's disease (AD) are likely to be more efficacious if administered early in the course of the disease, foregoing the spread of irreversible changes in the brain. Research findings underline an early vulnerability of the isodendritic core (IC) network to AD neurofibrillary lesions. The IC constitutes a phylogenetically conserved subcortical system including the locus coeruleus in pons, dorsal raphe nucleus, and substantia nigra in the midbrain, and nucleus basalis of Meynert in basal forebrain. Through their ascending projections to the cortex, the IC neurons regulate homeostasis and behavior by synthesizing aminergic and cholinergic neurotransmitters. Here we reviewed the evidence demonstrating that neurons of the IC system show neurofibrillary tangles in the earliest stages of AD, prior to cortical pathology, and how this involvement may explain pre-amnestic symptoms, including depression, agitation, and sleep disturbances in AD patients. In fact, clinical and animal studies show a significant reduction of AD cognitive and behavioral symptoms following replenishment of neurotransmitters associated with the IC network. Therefore, the IC network represents a unique candidate for viable therapeutic intervention and should become a high priority for research in AD.

Concepts for communication about risk in dementia care: A review of the literature

Communication about risk is central to decisions in dementia care. This review synthesises research on risk concepts and communication in dementia. Twelve bibliographic databases and one online search engine were searched up to February 2016. Reference lists of two related literature reviews were used. Thirty-four articles were identified that focused on risk concepts; two articles related to risk communication. Concepts were often socially constructed, and perceptions may differ from actual adverse outcomes. Perceptions of risk and thresholds of risk-tolerance varied between individuals with dementia, carers and professionals. Individuals with dementia were found to behave differently from controls when making decisions involving risk information in experimental settings. Cognitive impairment was also associated with lower health numeracy. These findings highlight the importance of communication between stakeholders when making decisions and of presenting information in an appropriate way to support informed and positive risk taking. Research is required on risk communication in dementia.

Melanopsin retinal ganglion cell loss and circadian dysfunction in Alzheimer's disease (Review)

Alzheimer's disease affects 27 million individuals and is the most common cause of dementia worldwide. The pathology of Alzheimer's disease is primarily due to the β‑amyloid deposits and neurofibrillary tangles. These deposits exist largely in the cerebral blood vessels, but have also been shown to exist in retinal vessels. A new class of cells that were recently identified, known as melanopsin‑expressing retinal ganglion cells (mRGCs), are involved in the non‑image forming functions of the eye. These functions include circadian activities such as temperature rhythms, melatonin release and rest‑activity cycles. Circadian dysfunction has been investigated in many cases of Alzheimer's disease. In this review, we outline the current accepted Alzheimer's disease pathology, the role of mRCGs in optic neuropathies and the role of mRCGs, leading to circadian dysfunction, in Alzheimer's disease.