Prognostic factors in very old demented adults: a seven-year follow-up from a population-based survey in Stockholm

Acetyl-cholinesterase-inhibitors reconsidered. A narrative review of post-marketing studies on Alzheimer's disease

The real efficacy of Acetyl-cholinesterase-inhibitors (AChEI) has been questioned. In this narrative review we evaluated their effect on cognitive decline, measured by Mini Mental State Examination (MMSE), and on total mortality rates in patients with Alzheimer's disease (AD) recruited into post-marketing open/non-randomized/retrospective studies. In AD patients treated with AChEI, the mean MMSE loss ranged from 0.2 to 1.37 points/years, compared with 1.07-3.4 points/years in non-treated patients. Six studies also reported data about survival; a reduction in total mortality relative risk between 27% and 42% was observed, over a period of 2-8 years. The type of studies and the use of MMSE to assess cognitive decline, may have introduced several biases. However, the clinical effects of AChEI seem to be of the same order of magnitude as the drugs currently used in most common chronic disorders, as regards progression of the disease and total mortality. In the absence of long-term randomized trials on "standard" unselected AD outpatients, open/retrospective studies and health databases represent the best available evidence on the possible effect of AChEI in the real-word setting. Our data support the clinical benefit of AChEI in older patients affected by AD.

[Mortality associated with neurocognitive disorder and dependence in people over 55 years of age. Systematic review]

INTRODUCTION

The increasing aging of the population brings with it an increase in the incidence of neurocognitive disorder (NCD) as well as various situations that generate dependence.

OBJECTIVE

To analyze by means of a systematic review the relationship between NCD and dependence with the risk of mortality in the elderly.

METHODS

A bibliographic search of longitudinal studies published in Pubmed and Scopus addressing the relationship between NCI, dependence for basic activities of daily living (ADL) and mortality published between 1995 and 2021 was performed. Of the 1040 articles found, 10 studies were selected.

RESULTS

It was observed that cohorts of elderly people with NCI presented mortality risk associated with ABVD impairment (Barthel test) and Mini-Mental State Examination scores following a significant linear trend. Other factors associated with mortality risk were low levels of education, living alone, and frailty.

CONCLUSIONS

The results underline the importance of performing assessments of cognitive and functional status using validated scales, since both areas are associated with mortality. The link between the three terms used in the search for this work is clear, but it is noteworthy that there are few longitudinal studies that analyze them together. The assessment of dependence and cognitive function in older adults should be considered in both research and clinical practice as it would provide information on their possible relationship with mortality.

Sex differences in default mode network connectivity in healthy aging adults

Women show an increased lifetime risk of Alzheimer's disease (AD) compared with men. Characteristic brain connectivity changes, particularly within the default mode network (DMN), have been associated with both symptomatic and preclinical AD, but the impact of sex on DMN function throughout aging is poorly understood. We investigated sex differences in DMN connectivity over the lifespan in 595 cognitively healthy participants from the Human Connectome Project-Aging cohort. We used the intrinsic connectivity distribution (a robust voxel-based metric of functional connectivity) and a seed connectivity approach to determine sex differences within the DMN and between the DMN and whole brain. Compared with men, women demonstrated higher connectivity with age in posterior DMN nodes and lower connectivity in the medial prefrontal cortex. Differences were most prominent in the decades surrounding menopause. Seed-based analysis revealed higher connectivity in women from the posterior cingulate to angular gyrus, which correlated with neuropsychological measures of declarative memory, and hippocampus. Taken together, we show significant sex differences in DMN subnetworks over the lifespan, including patterns in aging women that resemble changes previously seen in preclinical AD. These findings highlight the importance of considering sex in neuroimaging studies of aging and neurodegeneration.

Single-cell transcriptomic atlas of Alzheimer's disease middle temporal gyrus reveals region, cell type and sex specificity of gene expression with novel genetic risk for MERTK in female

Alzheimer's disease, the most common age-related neurodegenerative disease, is closely associated with both amyloid-ß plaque and neuroinflammation. Two thirds of Alzheimer's disease patients are females and they have a higher disease risk. Moreover, women with Alzheimer's disease have more extensive brain histological changes than men along with more severe cognitive symptoms and neurodegeneration. To identify how sex difference induces structural brain changes, we performed unbiased massively parallel single nucleus RNA sequencing on Alzheimer's disease and control brains focusing on the middle temporal gyrus, a brain region strongly affected by the disease but not previously studied with these methods. We identified a subpopulation of selectively vulnerable layer 2/3 excitatory neurons that that were RORB-negative and CDH9-expressing. This vulnerability differs from that reported for other brain regions, but there was no detectable difference between male and female patterns in middle temporal gyrus samples. Disease-associated, but sex-independent, reactive astrocyte signatures were also present. In clear contrast, the microglia signatures of diseased brains differed between males and females. Combining single cell transcriptomic data with results from genome-wide association studies (GWAS), we identified MERTK genetic variation as a risk factor for Alzheimer's disease selectively in females. Taken together, our single cell dataset revealed a unique cellular-level view of sex-specific transcriptional changes in Alzheimer's disease, illuminating GWAS identification of sex-specific Alzheimer's risk genes. These data serve as a rich resource for interrogation of the molecular and cellular basis of Alzheimer's disease.

Effect of Comorbidities on Ten-Year Survival in Patients with Dementia

BACKGROUND

There is a verified association between comorbidity and survival in patients with dementia.

OBJECTIVE

To describe the ten-year survival probability of patients with dementia and to identify the impact of comorbidity.

METHODS

The prognostic retrospective cohort study was conducted using data from adults with dementia who had visited the outpatient departments at Maharaj Nakorn Chiang Mai hospital between 2006 and 2012. Dementia was verified in accordance with standard practice guidelines. Secondary data detailing about patient age, gender, date of dementia diagnosis and death, types of dementia, and comorbidities at the time of dementia diagnosis was obtained from electronic medical records. The association between comorbidity, patients' underlying disease at dementia diagnosis, and overall survival were analyzed using a multivariable Cox proportional hazard model adjusted for age, gender, types of dementia, and other comorbidities.

RESULTS

Of the 702 patients, 56.9% were female. Alzheimer's disease (39.6%) was the most prevalent type of dementia. Median overall survival was 6.0 years (95% CI 5.5- 6.7). The comorbidities associated with a high risk of mortality included liver disease (aHR 2.70, 95% CI 1.46- 5.00), atrial fibrillation (aHR 2.15, 95% CI 1.29- 3.58), myocardial infarction (aHR 1.55, 95% CI 1.07- 2.26), and type 2 diabetes mellitus (aHR 1.40, 95% CI 1.13- 1.74).

CONCLUSION

Overall survival rate of patients with dementia in Thailand was comparable to previous studies. Several comorbidities were associated with a ten-year survival. The prognosis of patients with dementia may be improved by appropriate care of comorbidities.

The role of spirituality and religiosity on the cognitive decline of community-dwelling older adults: a 4-year longitudinal study

OBJECTIVES

This study aims to assess whether having religious beliefs, attending religious services and using spiritual-religious coping (SRC) are longitudinally associated with cognitive decline in community-dwelling older adults.

METHODS

A 4-year longitudinal study of 261 Brazilian older adults was conducted. Hierarchical adjusted linear regression models and logistic regression models were performed to evaluate the longitudinal effects of religious beliefs, church attendance and positive and negative SRC on cognitive decline.

RESULTS

The findings revealed that spiritual and religious beliefs at baseline could affect cognitive function in two different ways. When older adults use religiosity and spirituality (RS) in a functional positive manner, it results in better cognitive outcomes and a slower rate of decline. However, when used in a negative manner, it results in worse cognitive outcomes.

CONCLUSION

These results could help health care professionals address SRC among older adults, particularly those at a higher risk of cognitive decline. Considering that RS is very important for older adults, health care professionals should be aware of the beliefs of their patients and address RS in clinical practice.

Management in severe dementia: recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology

ABSTRACT Alzheimer’s disease (AD) and other neurodegenerative dementias have a progressive course, impairing cognition, functional capacity, and behavior. Most studies have focused on AD. Severe dementia is associated with increased age, higher morbidity-mortality, and rising costs of care. It is fundamental to recognize that severe dementia is the longest period of progression, with patients living for many years in this stage. It is the most heterogeneous phase in the process, with different abilities and life expectancies. This practice guideline focuses on severe dementia to improve management and care in this stage of dementia. As it is a long period in the continuum of dementia, clinical practice should consider non-pharmacological and pharmacological approaches. Multidisciplinary interventions (physical therapy, speech therapy, nutrition, nursing, and others) are essential, besides educational and support to caregivers.

Manejo das demências em fase avançada: recomendações do Departamento Científico de Neurologia Cognitiva e do Envelhecimento da Academia Brasileira de Neurologia

RESUMO A doença de Alzheimer (DA) e outras demências neurodegenerativas têm um curso progressivo com comprometimento da cognição, capacidade funcional e comportamento. A maioria dos estudos enfocou a DA. A demência grave está associada ao aumento da idade, maior morbimortalidade e aumento dos custos de cuidados. É fundamental reconhecer que a demência grave é o período mais longo de progressão, com o paciente vivendo muitos anos nesta fase. É a fase mais heterogênea do processo, com diferentes habilidades e expectativa de vida. Esta diretriz de prática concentra-se na demência grave para melhorar o manejo e o cuidado nessa fase da demência. Como um longo período no continuum da demência, as abordagens não farmacológicas e farmacológicas devem ser consideradas. Intervenções multidisciplinares (fisioterapia, fonoaudiologia, nutrição, enfermagem, entre outras) são essenciais, além de educacionais e de apoio aos cuidadores.

The effect of socioeconomic status on mortality among Alzheimer's disease patients: A nationwide population-based cohort study in Korea

To investigate the effects of household income level on all-cause mortality in patients with Alzheimer's disease (AD). Data was obtained from 7,937 participants in the Korean National Health Insurance cohort who was newly diagnosed with Alzheimer's disease using the anti-dementia medication between 2003 and 2013. All individuals were followed-up until December 2013 or death, whichever came first. Individual income was estimated from the national health insurance premium. Information on mortality was obtained from the Korean National Statistical Office. Cox proportional hazard models were used to compare mortality rates between different income groups after adjusting for possible confounding risk factors. Of 7937 participants, 2292 AD patients (28.9%) died. Those with low, middle-low, middle income level were likely to have more increasing risk of mortality (HR 1.142 [1.022-1.276], HR 1.211 [1.045-1.402], and HR 1.158 [1.009-1.328], respectively), compared to those with high income level. The findings of this study indicate that AD patients with low income level have higher risk for mortality. Promotion of targeted policies and priority support for these groups may help reduce the mortality rate in this vulnerable group.

A New Nomogram Model for Individualized Prediction of Cognitive Impairment in Patients with Acute Ischemic Stroke

BACKGROUND

Cognitive impairment is a common symptom after ischemic stroke. Such symptom can cause effect on rehabilitation of patients and their quality of life and. As stroke rapidly growth on nowadays, a reliable scoring tool to detect the risk of cognitive impairment after stroke is now being put on the first place.

METHODS

We enrolled patients with acute ischemic stroke (AIS) as samples and hospitalized all at the First Affiliated Hospital of Soochow University between October 2018 and June 2020. All patients were assessed by the Montreal Cognitive Assessment (MoCA) scales and MoCA score < 26 was defined as standard to have having cognitive impairment. All patients were randomly (7:3) divided into two cohorts: the primary ones and the validated ones. Based on multivariate logistic model, the independent predictors of cognitive impairment in the acute phase were identified. The predictive nomogram was generated and evaluated by Harrell's concordance index (C-index) and calibration plot both in two cohorts, respectively.

RESULTS

A total of 191 patients were enrolled, of whom 135 comprised the primary cohort and 56 comprised the validated cohort. Gender, age, baseline NIHSS score, hyperhomocysteinemia (HHcy) and multiple lesions were independently associated with acute cognitive impairment after stroke and included to construct the nomogram. The nomogram derived from the primary cohort had an Area Under Curve (AUC) of 0.773 and the validated ones had an AUC of 0.859. Calibration plot revealed adequate fit of the nomogram in predictive value.

CONCLUSION

The new nomogram based on gender, age, baseline NIHSS score, HHcy and multiple lesions gave rise to an accurate and comprehensive prediction for cognitive impairment in AIS patients. After further validation, it could potentially be a reliable forecasting tool.

Dementia increases mortality beyond effects of comorbid conditions: A national registry-based cohort study

BACKGROUND AND PURPOSE

Mortality is known to be markedly increased in people with dementia. However, the association between multiple chronic conditions and mortality in dementia is not well clarified. The aim of this study was to investigate the impact of somatic and psychiatric diseases on mortality in dementia compared with the general elderly population.

METHODS

Using a cohort study design, nationwide registry data from 2006 to 2015 on dementia and psychiatric and somatic comorbidities defined by the Charlson Comorbidity Index (CCI) were linked. Impact of chronic conditions was assessed according to mortality rate ratios (MRRs) in all Danish residents aged ≥65 years with and without dementia.

RESULTS

Our population comprised 1,518,917 people, of whom 114,109 people were registered with dementia. The MRRs was 2.70 (95% confidence interval 2.68, 2.72) in people with dementia after adjusting for sex, age, calendar year, and comorbidities. MRRs increased with higher CCI score, and when comparing people with a similar comorbidity load, MRRs were significantly higher for people with dementia.

CONCLUSIONS

The comorbidity load was associated with increased mortality in both people with and without dementia. Mortality in dementia remained increased, even after adjusting for psychiatric and chronic somatic comorbidities. Our findings suggest that dementia disorders alone contribute to excess mortality, which may be further increased by comorbidities.

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.

Causes of death in a nationwide cohort of community-dwellers with Alzheimer's disease

Background

Alzheimer’s disease (AD) is related to higher mortality but it is not entirely evident which causes of death explain this. The objective of this study was to assess the causes of death in a nationwide cohort of clinically verified AD cases and compare the causes to a matched comparison cohort without AD.

Methods

Cohort of all community-dwellers with clinically verified AD residing in Finland on 31 December 2005 (n = 27,948) and a matched comparison cohort without AD (n = 27,948). Mortality (2006–2012, n = 30,641, 54.8%) and causes of death were obtained from register. Cause of death was ascertained with clinical examination (87.3% of deaths), forensic (8.0%) or medical autopsy (4.7%).

Results

In AD cohort, the most common causes were diseases of the nervous system (49.9%), circulatory system (31.7%) and neoplasms (7.7%), while diseases of circulatory system (53.5%), neoplasms (19.1%) and mental and behavioral disorders (7.3%) contributed for majority of deaths in the comparison cohort. There were no sex-wise differences. People with AD were over 20 times more likely to die due to diseases of the nervous system (OR, 95% CI 22.06, 19.87–24.25) than the comparison cohort, while other causes, e.g., diseases of the circulatory system (0.40, 0.38–0.42), neoplasms (0.35, 0.33–0.38), mental and behavioral disorders (0.27, 0.24–0.30) and external causes of morbidity and mortality (0.72, 0.62–0.81) were less common in the AD cohort.

Conclusions

Although half of the people with AD died due to diseases of the nervous system, cancers and especially cardio/cerebrovascular diseases were still important contributors to the overall mortality among them. This should be acknowledged when planning their terminal care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-020-01744-z.

The effect of insomnia on development of Alzheimer's disease

Alzheimer's disease (AD) is the most common type of dementia and a neurodegenerative disorder characterized by memory deficits especially forgetting recent information, recall ability impairment, and loss of time tracking, problem-solving, language, and recognition difficulties. AD is also a globally important health issue but despite all scientific efforts, the treatment of AD is still a challenge. Sleep has important roles in learning and memory consolidation. Studies have shown that sleep deprivation (SD) and insomnia are associated with the pathogenesis of Alzheimer's disease and may have an impact on the symptoms and development. Thus, sleep disorders have decisive effects on AD; this association deserves more attention in research, diagnostics, and treatment, and knowing this relation also can help to prevent AD through screening and proper management of sleep disorders. This study aimed to show the potential role of SD and insomnia in the pathogenesis and progression of AD.

A second X chromosome contributes to resilience in a mouse model of Alzheimer's disease

A major sex difference in Alzheimer's disease (AD) is that men with the disease die earlier than do women. In aging and preclinical AD, men also show more cognitive deficits. Here, we show that the X chromosome affects AD-related vulnerability in mice expressing the human amyloid precursor protein (hAPP), a model of AD. XY-hAPP mice genetically modified to develop testicles or ovaries showed worse mortality and deficits than did XX-hAPP mice with either gonad, indicating a sex chromosome effect. To dissect whether the absence of a second X chromosome or the presence of a Y chromosome conferred a disadvantage on male mice, we varied sex chromosome dosage. With or without a Y chromosome, hAPP mice with one X chromosome showed worse mortality and deficits than did those with two X chromosomes. Thus, adding a second X chromosome conferred resilience to XY males and XO females. In addition, the Y chromosome, its sex-determining region Y gene (Sry), or testicular development modified mortality in hAPP mice with one X chromosome such that XY males with testicles survived longer than did XY or XO females with ovaries. Furthermore, a second X chromosome conferred resilience potentially through the candidate gene Kdm6a, which does not undergo X-linked inactivation. In humans, genetic variation in KDM6A was linked to higher brain expression and associated with less cognitive decline in aging and preclinical AD, suggesting its relevance to human brain health. Our study suggests a potential role for sex chromosomes in modulating disease vulnerability related to AD.

Education and Cognitive Functioning Across the Life Span

Cognitive abilities are important predictors of educational and occupational performance, socioeconomic attainment, health, and longevity. Declines in cognitive abilities are linked to impairments in older adults' everyday functions, but people differ from one another in their rates of cognitive decline over the course of adulthood and old age. Hence, identifying factors that protect against compromised late-life cognition is of great societal interest. The number of years of formal education completed by individuals is positively correlated with their cognitive function throughout adulthood and predicts lower risk of dementia late in life. These observations have led to the propositions that prolonging education might (a) affect cognitive ability and (b) attenuate aging-associated declines in cognition. We evaluate these propositions by reviewing the literature on educational attainment and cognitive aging, including recent analyses of data harmonized across multiple longitudinal cohort studies and related meta-analyses. In line with the first proposition, the evidence indicates that educational attainment has positive effects on cognitive function. We also find evidence that cognitive abilities are associated with selection into longer durations of education and that there are common factors (e.g., parental socioeconomic resources) that affect both educational attainment and cognitive development. There is likely reciprocal interplay among these factors, and among cognitive abilities, during development. Education-cognitive ability associations are apparent across the entire adult life span and across the full range of education levels, including (to some degree) tertiary education. However, contrary to the second proposition, we find that associations between education and aging-associated cognitive declines are negligible and that a threshold model of dementia can account for the association between educational attainment and late-life dementia risk. We conclude that educational attainment exerts its influences on late-life cognitive function primarily by contributing to individual differences in cognitive skills that emerge in early adulthood but persist into older age. We also note that the widespread absence of educational influences on rates of cognitive decline puts constraints on theoretical notions of cognitive aging, such as the concepts of cognitive reserve and brain maintenance. Improving the conditions that shape development during the first decades of life carries great potential for improving cognitive ability in early adulthood and for reducing public-health burdens related to cognitive aging and dementia.

Sex/gender differences in cognitive trajectories vary as a function of race/ethnicity

INTRODUCTION

The present study sought to determine whether cognitive trajectories differ between men and women across and within racial/ethnic groups.

METHODS

Participants were 5258 non-Hispanic White (NHW), Black, and Hispanic men and women in the Washington/Hamilton Heights-Inwood Columbia Aging Project who were administered neuropsychological tests of memory, language, and visuospatial abilities at 18- to 24-month intervals for up to 25 years. Multiple-group latent growth curve modeling examined trajectories across sex/gender by race/ethnicity.

RESULTS

After adjusting for age and education, the largest baseline differences were between NHW men and Hispanic women on visuospatial and language, and between NHW women and Black men on memory. Memory and visuospatial decline was steeper for Black women compared with Hispanic men and NHW women, respectively.

DISCUSSION

This study takes an important first step in understanding interactions between race/ethnicity and sex/gender on cognitive trajectories by demonstrating variability in sex/gender differences across race/ethnicity.

Is Dementia More Fatal Than Previously Estimated? A Population-based Prospective Cohort Study

Dementia increases the risk of mortality (ROM) in the elderly and estimates of hazard ratio (HR) of dementia for mortality have ranged from 1.7 to 6.3. However, previous studies may have underestimated ROM of dementia due to length bias, which occurs when failing to include the persons with rapidly progressive diseases, who died before they could be included in the study. This population-based prospective cohort study conducted on 6,752 randomly sampled Koreans, aged 60 years or older (the Korean Longitudinal Study on Cognitive Aging and Dementia). Cognitive disorders were evaluated at baseline and 2-year follow-up using the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K), and prevalent and incident cases of dementia were identified. The participants' deaths were confirmed through the National Mortality Database of Statistics Korea. We compared the ROM between prevalent and incident dementia, and estimated HR of dementia for mortality using Cox proportional hazards model. Of the 5,097 responders to the 2-year follow-up assessment, 150 participants had dementia from the baseline (prevalent dementia), and 95 participants developed dementia during the 2-year follow-up period (incident dementia). The ROM of participants with incident dementia was about 3 times higher than the ROM of those with prevalent dementia (HR = 3.04, 95% confidence interval [CI] = 1.34-6.91). Compared to cognitively normal participants at both the baseline and 2-year follow-up assessments, the ROM of those with incident dementia approximately 8 times higher (HR = 8.37, 95 % CI = 4.23-16.54). In conclusion, the ROM of dementia using prevalent cases was underestimated due to length bias, and dementia may be much more fatal than previously estimated. In clinical settings, the ROM of dementia warrants the attention of physicians, particularly in recently incident dementia cases.

Can Animal Models Inform on the Relationship between Depression and Alzheimer Disease?

The focus on the β-amyloid (Aβ) peptide in clinical Alzheimer disease (AD) as well as in animal models of AD has perhaps biased our understanding of what contributes to the heterogeneity in disease onset and progression. Part of this heterogeneity could reflect the various neuropsychiatric risk factors that present with common symptomatology and can predispose the brain to AD-like changes. One such risk factor is depression. Animal models, particularly mouse models carrying variants of AD-related gene(s), many of which lead to an accumulation of Aβ, suggest that a fundamental shift in depression-related monoaminergic systems (including serotonin and noradrenaline) is a strong indicator of the altered cellular function associated with the earlier(est) stages of AD-related pathology. These changes in monoaminergic neurochemistry could provide for relevant targets for intervention in clinical AD and/or could support a polypharmacy strategy, which might include the targeting of Aβ, in vulnerable populations. Future studies must also include female mice as well as male mice in animal model studies on the relationship between depression and AD.

16-Year Survival of the Canadian Collaborative Cohort of Related Dementias

Background Survival estimates are integral to care for patients diagnosed with dementia. Few Canadian studies have carried out long-term follow-up of well-described cohorts, analyzing survival related to multiple risk factors. Methods Survival analysis of an inception cohort enrolled at a British Columbia (BC) tertiary dementia referral clinic between 1997 and 1999 was undertaken. Vital status was completed for 168 patients diagnosed with dementia. An evaluation of the effects of demographics, vascular risk factors, cognitive and functional ratings, apolipoprotein 4-status, and cholinesterase use on survival was performed using a log-rank test and time-dependent Cox regression. Survival of this dementia cohort was compared with the age-matched life expectancy of persons in BC. Results In all, 158/168 (94.0%) subjects died over 16.6 years, with a median survival of 7.08 years. Risk factors associated with shorter survival in dementia groups included age of onset ≥80 (hazard ratio [HR] 1.56, 95% confidence interval [CI] 1.05-2.32); greater functional disability (Disability Assessment for Dementia<55% [HR 1.47, 95% CI 1.04-2.08]); and cumulative medical illness severity (Cumulative Illness Rating Scale≥7 [HR 1.51, 95% CI 1.08-2.12)]. Compared with the BC population, years of potential life lost for dementia subjects aged <65 was 15.36 years, and for dementia subjects aged ≥80 it was 1.82 years. Conclusions Survival in dementia subjects is shorter than population life expectancies for each age strata, with greatest impact on younger patients. For people diagnosed with dementia, age ≥80 years, cumulative medical illness severity, and functional disabilities are the most significant survival predictors and can be used to guide prognosis.

Impacts of Illiteracy on the Risk of Dementia: A Global Health Perspective

Despite its significance as a contributing factor for late-life dementia risk, illiteracy is frequently underappreciated in the management of dementia. In this study, we estimated the proportion of dementia cases attributable to illiteracy using the population attributable fraction (PAF), and calculated to what extent the monetary cost of dementia could be saved in the future by reducing illiteracy from the South Korean, Latin American, South Asian/Middle Eastern, and African populations. We collected necessary data from the 2011 United Nations Human Development Report and prevalence studies conducted in these regions. Additional variables not included in the above sources were estimated using a logit model under a "trend scenario"-based assumption. Around 16% of the total number of dementia cases in South Korea in 2015 can be attributed to illiteracy, with this figure predicted to decline to around 2% by 2050. This translates to a saving in dementia care costs of approximately 52 billion USD, providing we are successful in theoretically eradicating illiteracy as of 2015, in the population aged 65 years or under. Likewise, reducing illiteracy to 50% in Latin America, South Asia/The Middle East, and Africa by 2050 could generate further cost savings of between 71 and 244 billion, 13 and 94 billion, and 17 and 78 billion USD, respectively. Even public policies aimed solely at reducing illiteracy in the childhood, adolescent, or middle-aged population could potentially have a role in the primary prevention of dementia. Moving forward, governments will need to address this issue in a purposeful and systematic manner.

Cognitive behavioral therapy (CBT) for preventing Alzheimer's disease

This review provides the rationale for implementing cognitive behavioral therapy (CBT) for the prevention of Alzheimer's disease (AD). There are known risk factors associated with the development of AD, some of which may be ameliorated with CBT. We posit that treating the risk factors of inactivity, poor diet, hyposmia and anosmia, sleep disorders and lack of regularly engaged challenging cognitive activity will modify the physiology of the brain sufficiently to avoid the accumulation of excess proteins, including amyloid beta, causal events in the development of AD. Further, the successful treatment of the listed risk factors is well within our technology to do so and, even further, it is cost effective. Also, there is considerable scientific literature to support the proposition that, if implemented by well-established practices, CBT will be effective and will be engaged by those of retirement age. That is, we present a biologically informed CBT for the prevention of the development of AD, i.e., an aspect of applied behavioral neuroscience.

High education accelerates cognitive decline in dementia: A brief report from the population-based NEDICES cohort

High education has been associated with faster cognitive decline after diagnosis of Alzheimer's disease (AD), but it is unclear whether these findings extend to other dementia subtypes.

Survival Curves and Behavioral Profiles of Female 3xTg-AD Mice Surviving to 18-Months of Age as Compared to Mice with Normal Aging

New evidence reveals a high degree of heterogeneity in Alzheimer's disease (AD) clinical and temporal patterns, supporting the existence of several subgroups of patients. Prognosticators of end-of-life dementia specific to elderly patients are necessary to address this heterogeneity. Among 3xTg-AD mice, a widely-used model for AD, a very small number of animals overcome advanced neuropathological stages of disease beyond 18 months of age. They are usually females, which reach longevity in spite of worse neuropathological status as compared to males (the morbidity/mortality paradox). We posit that 3xTg-AD long-term survivors could serve to model end-of-life dementia but also aware about the mortality selection bias. In the present study, we performed behavioral and functional phenotype in long-term survivors, 18-month-old female 3xTg-AD mice and age-matched wildtype undergoing normal aging. Animals were followed up until natural death to correlate survival with phenotype assessments. Strong similarity of their behavioral profiles in all the variables analyzed (e.g. reflexes, sensorimotor functions, locomotion, exploration, emotionality, and anxiety-like behaviors) was found, with the exception of memory impairment, which was a salient trait in old 3xTg-AD survivors. The two groups showed similar mean life expectancy and had behavioral correlates among lifespan, neophobia and long-term memory in common, with some distinctions in 3xTg-AD, supporting recent studies in end-of-life patients. In spite of the small sample size, this brief report presents an interesting scenario to further study heterogeneity and survival in Alzheimer's disease. 3xTg-AD survivors may be a model to gain insight into the frailty/survival paradigm in normal and pathological aging.

Comorbidity and progression of late onset Alzheimer's disease: A systematic review

Background

Alzheimer’s disease is a neurodegenerative syndrome characterized by multiple dimensions including cognitive decline, decreased daily functioning and psychiatric symptoms. This systematic review aims to investigate the relation between somatic comorbidity burden and progression in late-onset Alzheimer’s disease (LOAD).

Methods

We searched four databases for observational studies that examined cross-sectional or longitudinal associations of cognitive or functional or neuropsychiatric outcomes with comorbidity in individuals with LOAD. From the 7966 articles identified originally, 11 studies were included in this review. The Newcastle-Ottawa quality assessment was used. The large variation in progression measures, comorbidity indexes and study designs hampered the ability to perform a meta-analysis. This review was registered with PROSPERO under DIO: 10.15124/CRD42015027046.

Results

Nine studies indicated that comorbidity burden was associated with deterioration in at least one of the three dimensions of LOAD examined. Seven out of ten studies investigating cognition found comorbidities to be related to decreased cognitive performance. Five out of the seven studies investigating daily functioning showed an association between comorbidity burden and decreased daily functioning. Neuropsychiatric symptoms (NPS) increased with increasing comorbidity burden in two out of three studies investigating NPS. Associations were predominantly found in studies analyzing the association cross-sectionally, in a time-varying manner or across short follow-up (≤2 years). Rarely baseline comorbidity burden appeared to be associated with outcomes in studies analyzing progression over longer follow-up periods (>2 years).

Conclusion

This review provides evidence of an association between somatic comorbidities and multifaceted LOAD progression. Given that time-varying comorbidity burden, but much less so baseline comorbidity burden, was associated with the three dimensions prospectively, this relationship cannot be reduced to a simple cause-effect relation and is more likely to be dynamic. Therefore, both future studies and clinical practice may benefit from regarding comorbidity as a modifiable factor with a possibly fluctuating influence on LOAD.

The association of antidepressant drug usage with cognitive impairment or dementia, including Alzheimer disease: A systematic review and meta-analysis

OBJECTIVE

To determine if antidepressant drug usage is associated with cognitive impairment or dementia, including Alzheimer disease (AD).

METHOD

We conducted a systematic search of Medline, PubMed, PsycINFO, Web of Science, Embase, CINAHL, and the Cochrane Library. An initial screen by abstracts and titles was performed, and relevant full articles were then reviewed and assessed for their methodologic quality. Crude effect estimates were extracted from the included articles and a pooled estimate was obtained using a random effects model.

RESULTS

Five articles were selected from an initial pool of 4,123 articles. Use of antidepressant drugs was associated with a significant twofold increase in the odds of some form of cognitive impairment or dementia (OR = 2.17). Age was identified as a likely modifier of the association between antidepressant use and some form of cognitive impairment or AD/dementia. Studies that included participants with an average age equal to or greater than 65 years showed an increased odds of some form of cognitive impairment with antidepressant drug usage (OR = 1.65), whereas those with participants less than age 65 revealed an even stronger association (OR = 3.25).

CONCLUSIONS

Antidepressant drug usage is associated with AD/dementia and this is particularly evident if usage begins before age 65. This association may arise due to confounding by depression or depression severity. However, biological mechanisms potentially linking antidepressant exposure to dementia have been described, so an etiological effect of antidepressants is possible. With this confirmation that an association exists, clarification of underlying etiologic pathways requires urgent attention.

Triad of Risk for Late Onset Alzheimer's: Mitochondrial Haplotype, APOE Genotype and Chromosomal Sex

Brain is the most energetically demanding organ of the body, and is thus vulnerable to even modest decline in ATP generation. Multiple neurodegenerative diseases are associated with decline in mitochondrial function, e.g., Alzheimer’s, Parkinson’s, multiple sclerosis and multiple neuropathies. Genetic variances in the mitochondrial genome can modify bioenergetic and respiratory phenotypes, at both the cellular and system biology levels. Mitochondrial haplotype can be a key driver of mitochondrial efficiency. Herein, we focus on the association between mitochondrial haplotype and risk of late onset Alzheimer’s disease (LOAD). Evidence for the association of mitochondrial genetic variances/haplotypes and the risk of developing LOAD are explored and discussed. Further, we provide a conceptual framework that suggests an interaction between mitochondrial haplotypes and two demonstrated risk factors for Alzheimer’s disease (AD), apolipoprotein E (APOE) genotype and chromosomal sex. We posit herein that mitochondrial haplotype, and hence respiratory capacity, plays a key role in determining risk of LOAD and other age-associated neurodegenerative diseases. Further, therapeutic design and targeting that involve mitochondrial haplotype would advance precision medicine for AD and other age related neurodegenerative diseases.

Cognitively-Related Basic Activities of Daily Living Impairment Greatly Increases the Risk of Death in Alzheimers Disease

INTRODUCTION

Some Alzheimer's disease (AD) patients die without ever developing cognitively impaired basic activities of daily living (basic ADL), which may reflect slower disease progression or better compensatory mechanisms. Although impaired basic ADL is related to disease severity, it may exert an independent risk for death. This study examined the association between impaired basic ADL and survival of AD patients, and proposed a multistate approach for modeling the time to death for patients who demonstrate different patterns of progression of AD that do or do not include basic ADL impairment.

METHODS

1029 patients with probable AD at the Baylor College of Medicine Alzheimer's Disease and Memory Disorders Center met the criteria for this study. Two complementary definitions were used to define development of basic ADL impairment using the Physical Self-Maintenance Scale score. A weighted Cox regression model, including a time-dependent covariate (development of basic ADL impairment), and a multistate survival model were applied to examine the effect of basic ADL impairment on survival.

RESULTS

As expected decreased ability to perform basic ADL at baseline, age at initial visit, years of education, and sex were all associated with significantly higher mortality risk. In those unimpaired at baseline, the development of basic ADL impairment was also associated with a much greater risk of death (hazard ratios 1.77-4.06) over and above the risk conferred by loss of MMSE points. A multi-state Cox model, controlling for those other variables quantified the substantive increase in hazard ratios for death conferred by the development of basic ADL impairment by two definitions and can be applied to calculate the short term risk of mortality in individual patients.

CONCLUSIONS

The current study demonstrates that the presence of basic ADL impairment or the development of such impairments are important predictors of death in AD patients, regardless of severity.

The Potential of Gonadal Hormone Signalling Pathways as Therapeutics for Dementia

Dementia is an ever-expanding problem facing an ageing society. Currently, there is a sharp paucity of treatment strategies. It has long been known that sex hormones, namely 17β-estradiol and testosterone, possess neuroprotective- and cognitive-enhancing qualities. However, certain lacunae in the knowledge underlying their molecular mechanisms have delayed their use as treatment strategies in dementia. With recent advancements in pharmacology and molecular biology, especially in the development of safer selective oestrogen receptor modulators and the recent discovery of the small-molecule brain-derived neurotrophic factor receptor agonist, 7,8-dihydroxyflavone, the exploitation of these signalling pathways for clinical use has become possible. This review aims to adumbrate the evidence and hurdles underscoring the use of sex hormones in the treatment of dementia as well as discussing some direction that is required to advance the translation of evidence into practise.

Longitudinal Neuropsychiatric Predictors of Death in Alzheimer's Disease

Characteristics associated with life expectancy in Alzheimer's disease (AD) are still far from known. Here we aimed at examining the ability of baseline/longitudinal clinical variables to predict time to death. One-hundred fifty AD outpatients underwent diagnostic, neuropsychiatric, and functional assessment at baseline (when ApoE ɛ4 was also investigated) and at each subsequent annual visit. A random effects joint modeling approach was used to simultaneously model the baseline and longitudinal trajectory of each factor and predict the time to death, adjusting for demographic covariates. An ancillary analysis of ApoE ɛ4 status as a predictor was also conducted. Kaplan-Meier survival curves were constructed to elucidate the relationship between each factor and the estimated probability of death over time. Shorter survival was associated with male gender, higher education, older age, lower cognition, and worse functioning in daily life, but not ApoE ɛ4 status. Longitudinal trajectories increased predictive power over using just baseline levels highlighting apathy, and secondarily aberrant motor behaviors and sleep disorders, as a highly reliable predictor for mortality. Apathy was the strongest neuropsychiatric predictor of time to death, which supports its role in the pathogenesis of the disorder. An increased knowledge of factors modulating survival in AD is a strategic prerequisite to plan therapeutic interventions.

Advanced dementia: opinions of physicians and nurses about antibiotic therapy, artificial hydration and nutrition in patients with different life expectancies

AIM

The aim of the present study was to investigate the proportion of physicians and nurses who agree with the administration of antibiotic therapy (AT), artificial hydration (AH), and artificial nutrition (AN) in patients with advanced dementia and different life expectancies. Furthermore, we aimed at analyzing the correlates of the opinion according to which medical treatments should no longer be given to advanced dementia patients once their life expectancy falls.

METHODS

End-of-life decisions and opinions were measured with a questionnaire that was sent to geriatric units, hospices and nursing homes in three different regions of Italy. Multivariate logistic regressions were carried out to ascertain the correlates of the agreement with the administration of AH, AT or AN.

RESULTS

When the patient's life expectancy was 1-6 months, 83% of respondents agreed with AH, 79% with AT and 71% with AN. When the life expectancy was less than 1 month, a large proportion of respondents still agreed with AH and AT (73% and 61%), whereas less than one in two respondents (48%) agreed with AN.

CONCLUSIONS

The findings of the present study showed that AN creates more ethical dilemmas in the clinical management of end of life than other treatments, such as AH or AT. Opinions on whether or not these practices are appropriate at the end of life were related with feelings, thoughts and ethical issues that played a different part for physicians and nurses. Geriatr Gerontol Int 2017; 17: 487-493.

Survival in Subcortical Vascular Dementia: Predictors and Comparison to Probable Alzheimer's Disease in a Tertiary Memory Clinic Population

BACKGROUND

Subcortical vascular dementia (SVaD) is one of the most common dementias, after Alzheimer's disease (AD) dementia. Few survival analyses in SVaD patients have been reported.

METHODS

The dates and causes of death of 146 SVaD and 725 AD patients were included. We used the Cox proportional hazards model to compare survival between SVaD and AD patients and to explore possible factors related to survival of SVaD patients.

RESULTS

The median survival time after the onset of SVaD (109 months) was shorter than that recorded for AD (152 months). The most common cause of death in SVaD was stroke (47.1%). Factors associated with shorter survival in SVaD were late onset, male sex, worse baseline cognition, absence of hypertension and a family history of stroke.

CONCLUSIONS

Stroke prevention may be important in SVaD treatment because 47.1% of SVaD patients died of stroke. A family history of stroke and absence of hypertension were associated with a shorter survival in SVaD, suggesting the existence of genetic or unknown risk factors.

Mortality in incident dementia - results from the German Study on Aging, Cognition, and Dementia in Primary Care Patients

OBJECTIVE

Dementia is known to increase mortality, but the relative loss of life years and contributing factors are not well established. Thus, we aimed to investigate mortality in incident dementia from disease onset.

METHOD

Data were derived from the prospective longitudinal German AgeCoDe study. We used proportional hazards models to assess the impact of sociodemographic and health characteristics on mortality after dementia onset, Kaplan-Meier method for median survival times.

RESULTS

Of 3214 subjects at risk, 523 (16.3%) developed incident dementia during a 9-year follow-up period. Median survival time after onset was 3.2 years (95% CI = 2.8-3.7) at a mean age of 85.0 (SD = 4.0) years (≥2.6 life years lost compared with the general German population). Survival was shorter in older age, males other dementias than Alzheimer's, and in the absence of subjective memory complaints (SMC).

CONCLUSION

Our findings emphasize that dementia substantially shortens life expectancy. Future studies should further investigate the potential impact of SMC on mortality in dementia.

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.

Serum docosahexaenoic and eicosapentaenoic acid and risk of cognitive decline over 10 years among elderly Japanese

BACKGROUND/OBJECTIVES

To clarify the association of serum docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) levels with cognitive decline over 10 years.

SUBJECTS/METHODS

This study was part of the National Institute for Longevity Sciences - Longitudinal Study of Aging, and was conducted with 232 male and 198 female Japanese community-dwelling subjects aged 60-79 years in the second wave (2000-2002). Cognitive function was assessed with the Mini-Mental State Examination (MMSE) in both the second and seventh (2010-2012) waves. Fasting venous blood samples were collected in the morning, and serum DHA and EPA levels were measured. Multiple logistic regression analysis was performed among participants with an MMSE score ≥ 24 in the second wave (n=430) to estimate the odds ratio (OR) and 95% confidence interval (CI) for MMSE score ≤ 23 or MMSE score decline ≥ 4 10 years later. These estimates were based on baseline tertiles of serum DHA or EPA levels, and controlled for age, sex, education, MMSE score at baseline, alcohol consumption, current smoking, body mass index and disease history.

RESULTS

Fifteen (3.5%) subjects whose MMSE score was ≤ 23 and 36 (8.3%) subjects whose MMSE score declined to ≥ 4 showed cognitive decline. Multivariate-adjusted OR (95% CI) for the lowest through highest tertiles of serum DHA to MMSE score ≤ 23 or decline ≥ 4 were 1.00 (reference), 0.11 (0.02-0.58) and 0.17 (0.04-0.74), or 1.00 (reference), 0.22 (0.08-0.61) and 0.31 (0.12-0.75), respectively (P for trend=0.01 or 0.04). Serum EPA was not associated with cognitive decline.

CONCLUSIONS

The study gives some indication that a moderately high level of serum DHA might prevent cognitive decline among community-dwelling elderly Japanese individuals.

Clinical epidemiology of Alzheimer's disease: assessing sex and gender differences

With the aging of the population, the burden of Alzheimer’s disease (AD) is rapidly expanding. More than 5 million people in the US alone are affected with AD and this number is expected to triple by 2050. While men may have a higher risk of mild cognitive impairment (MCI), an intermediate stage between normal aging and dementia, women are disproportionally affected with AD. One explanation is that men may die of competing causes of death earlier in life, so that only the most resilient men may survive to older ages. However, many other factors should also be considered to explain the sex differences. In this review, we discuss the differences observed in men versus women in the incidence and prevalence of MCI and AD, in the structure and function of the brain, and in the sex-specific and gender-specific risk and protective factors for AD. In medical research, sex refers to biological differences such as chromosomal differences (eg, XX versus XY chromosomes), gonadal differences, or hormonal differences. In contrast, gender refers to psychosocial and cultural differences between men and women (eg, access to education and occupation). Both factors play an important role in the development and progression of diseases, including AD. Understanding both sex- and gender-specific risk and protective factors for AD is critical for developing individualized interventions for the prevention and treatment of AD.

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.

The Cache County Study on Memory in Aging: factors affecting risk of Alzheimer's disease and its progression after onset

The Cache County Study on Memory in Aging is a longitudinal, population-based study of Alzheimer's disease (AD) and other dementias. Initiated in 1995 and extending to 2013, the study has followed over 5,000 elderly residents of Cache County, Utah (USA) for over twelve years. Achieving a 90% participation rate at enrolment, and spawning two ancillary projects, the study has contributed to the literature on genetic, psychosocial and environmental risk factors for AD, late-life cognitive decline, and the clinical progression of dementia after its onset. This paper describes the major study contributions to the literature on AD and dementia.

Do Alzheimer's disease (AD) and subcortical ischemic vascular dementia (SIVD) progress differently?

Our study aimed to compare cognitive status and declines in AD with/without small vessel disease (SVD) and SIVD at baseline and 1-year follow-up. Patients with Alzheimer's disease without small vessel disease (AD(-)SVD) (n=148), Alzheimer's disease with small vessel disease (AD(+)SVD) (n=94) and SIVD (n=60) were recruited from database of multiple centers in Korea. Basic demographics and detailed neuropsychological results were compared. AD, regardless of SVD, showed worse memory and better executive function than SIVD at baseline. Mini-Mental State Examination scores and visual memory function declined more in AD than those in SIVD whereas Barthel Activities of Daily Living (B-ADL) scores declined more in SIVD. AD showed different patterns of cognitive impairment compared with SIVD. After 1 year, AD showed more rapid cognitive decline in some domains. Further investigations with longer follow-up duration may be needed to confirm the cumulative effects of SVD in AD and different patterns of decline between AD and SIVD.

Survival in dementia and predictors of mortality: a review

OBJECTIVE

Dementia is an important cause of mortality and, with the ageing population and increasing prevalence of dementia, reliable data on prognosis and survival will be of interest to patients and caregivers as well as providers and commissioners of health and social care. A review of the literature was undertaken to determine the rates of survival in dementia and Alzheimer's disease (AD) and to identify factors that are or are not predictive of mortality in dementia and AD.

METHODS

Relevant articles on mortality in dementia were identified following a search of several electronic databases from 1990 to September 2012. Inclusion criteria were reports on prospective community or clinic based cohorts published in English since 1990, to reflect more recent recognition of possible predictors.

RESULTS

Median survival time from age of onset of dementia ranges from 3.3 to 11.7 years, with most studies in the 7 to 10-year period. Median survival time from age of disease diagnosis ranges from 3.2 to 6.6 years for dementia or AD cohorts as a whole. Age was consistently reported as a predictor of mortality, with male gender a less consistent predictor. Increased disease severity and functional impairment were often associated with mortality.

CONCLUSIONS

Substantial heterogeneity in the design of included studies limits the ability to prognosticate for individual patients. However, it is clear that dementia and AD are associated with significant mortality. Reasons for the increased mortality are not established.

Survival of Alzheimer's disease patients in Korea

BACKGROUND/AIMS

The natural history of Alzheimer's disease (AD) has rarely been studied in the Korean population. Our study on survival analyses in Korean AD patients potentially provides a basis for cross-cultural comparisons.

METHODS

We studied 724 consecutive patients from a memory disorder clinic in a tertiary hospital in Seoul, who were diagnosed as having AD between April 1995 and December 2005. Deaths were identified by the Statistics Korea database. The Kaplan-Meier method was used for survival analysis, and a Cox proportional hazard model was used to assess factors related to patient survival.

RESULTS

The overall median survival from the onset of first symptoms and from the time of diagnosis was 12.6 years (95% confidence interval 11.7-13.4) and 9.3 years (95% confidence interval 8.7-9.9), respectively. The age of onset, male gender, history of diabetes mellitus, lower Mini-Mental State Examination score, and higher Clinical Dementia Rating score were negatively associated with survival. There was a reversal of risk of AD between early-onset and later-onset AD, 9.1 years after onset.

CONCLUSIONS

The results of our study show a different pattern of survival compared to those studies carried out with western AD populations. Mortality risk of early-onset AD varied depending on the duration of follow-up.

Burden of disease due to dementia in the elderly population of Korea: present and future

BACKGROUND

With the rapid aging of populations around the world, dementia has become one of the most important public health problems in Eastern Asian countries. The purpose of the present study was to provide an estimate of the burden of dementia and forecast its future burden, as generalized to the Korean population, and to provide detailed gender- and age-specific information regarding the burden of dementia in the elderly population of Korea.

METHODS

'Disability-adjusted life years' (DALYs) were used to estimate the burden of dementia. Epidemiologic data from national statistics and nationwide epidemiologic studies in the year 2008 were used to obtain representative outcomes for the Korean population. We estimated the DALYs due to dementia from the years 2010 to 2050 by applying demographic structure projections in terms of 5-year age groups in Korea.

RESULTS

The burden of disease due to dementia in Korea is 528 per 100,000 population (males: 435, females: 622) and 5,117 per 100,000 in those over the age of 65 years (males: 5,228; females: 5,041); this accounts for 4.5% of the total burden of disease in the year 2008. In the year 2050, DALYs due to dementia (814,629) are expected to be 3.0 times higher than those in the year 2010 (274,849).

CONCLUSION

Dementia has the highest burden of disease in the elderly Korean population, and this burden will increase sharply with the aging of the population. More comprehensive and multi-dimensional approaches, including clinical, psychological, social, and political means will be needed for the management of the dramatically increasing burden of dementia.

Sex-specific risk of cardiovascular disease and cognitive decline: pregnancy and menopause

Understanding the biology of sex differences is integral to personalized medicine. Cardiovascular disease and cognitive decline are two related conditions, with distinct sex differences in morbidity and clinical manifestations, response to treatments, and mortality. Although mortality from all-cause cardiovascular diseases has declined in women over the past five years, due in part to increased educational campaigns regarding the recognition of symptoms and application of treatment guidelines, the mortality in women still exceeds that of men. The physiological basis for these differences requires further research, with particular attention to two physiological conditions which are unique to women and associated with hormonal changes: pregnancy and menopause. Both conditions have the potential to impact life-long cardiovascular risk, including cerebrovascular function and cognition in women. This review draws on epidemiological, translational, clinical, and basic science studies to assess the impact of hypertensive pregnancy disorders on cardiovascular disease and cognitive function later in life, and examines the effects of post-menopausal hormone treatments on cardiovascular risk and cognition in midlife women. We suggest that hypertensive pregnancy disorders and menopause activate vascular components, i.e., vascular endothelium and blood elements, including platelets and leukocytes, to release cell-membrane derived microvesicles that are potential mediators of changes in cerebral blood flow, and may ultimately affect cognition in women as they age. Research into specific sex differences for these disease processes with attention to an individual's sex chromosomal complement and hormonal status is important and timely.

Considerations of sex and gender differences in preclinical and clinical trials

Women continue to be underrepresented in clinical trials, particularly in Phases I and II of experimental drug studies in spite of legislative guidelines in the USA, Canada, the European Union, Australia, and Japan requiring the inclusion of women in clinical trials. As such, women remain a vulnerable population subject to the adverse effects of pharmacological therapies. Thus, women experience higher rates of adverse drug reactions than do men and for women of reproductive age or who may be pregnant, therapeutic options may be limited. This chapter provides a brief history of inclusion of sex and gender as variables in clinical trials, summarizes governmental legislation for consideration of sex and gender in clinical trials and provides specific examples of drugs which have been withdrawn from the market because of side effects in women. Additional information related to sex and gender in preclinical testing, trial design, challenges to recruitment of women for clinical trials and statistical methods for analysis of data also is considered.

Cognitive and behavioural predictors of survival in Alzheimer disease: results from a sample of treated patients in a tertiary-referral memory clinic

OBJECTIVE

This study examined the influence of cognitive and non-cognitive factors at the time of diagnosis on the survival of patients with treated probable Alzheimer Disease (AD).

METHODS

Consecutive patients seen at a regional, tertiary-referral clinic completed a battery of cognitive tests and assessments of activities of daily living and neuropsychiatric symptoms. These clinic data were linked with death certificate data for all individuals and survival from diagnosis was calculated. Cox regression models were constructed using the baseline covariates.

RESULTS

The sample comprised 653 patients (459 women), mean age 77.1 years (SD 7.6, range 48-94 years), diagnosed with probable AD and treated with a cholinesterase inhibitor. In the survival analysis, age was a consistently significant predictor of survival with a gender-adjusted hazard ratio of 1.35 (95% CI 1.23, 1.48) for one standard deviation increase in age. Men were at greater risk of death than women (age-adjusted HR 1.44, 95% CI 1.19, 1.73). In a model adjusted for all study variables, Paired-Associate Learning (Cambridge Automated Neuropsychological Test Assessment Battery) and the psychotic factor of the Neuropsychiatric Inventory were significant predictors of survival.

CONCLUSIONS

At diagnosis, in addition to the anticipated impact of age and gender, the presence of psychotic symptoms and poor performance on paired-associate learning are also indicators of poor prognosis.

Effects of Food and Drug Administration-approved medications for Alzheimer's disease on clinical progression

BACKGROUND

Observational studies suggest that cholinesterase inhibitors and/or memantine may delay clinical progression of Alzheimer's disease (AD) in 40% of individuals taking the medications. Given this response and existence of side effects, we sought to quantify medication use and benefits in a population-based study of incident AD cases.

METHODS

The Cache County Dementia Progression Study enrolled and followed a cohort of 327 incident AD cases for a maximum of 9 years. Drug exposure was expressed using a persistency index (PI), calculated as total years of drug use divided by total years of observation. Linear mixed-effects models examined PI, and interactions with sex and apolipoprotein E (APOE) as predictors of clinical progression on the Mini-Mental State Examination and Clinical Dementia Rating-Sum of Boxes.

RESULTS

A total of 69 participants (21.1%) reported having ever used cholinesterase inhibitors or memantine. There was a strong three-way interaction between PI, sex, and time. Among women, a higher PI (i.e., greater duration of use) of cholinesterase inhibitors was associated with slower progression on the Mini-Mental State Examination and Clinical Dementia Rating-Sum of Boxes, particularly among those with an APOE ɛ4 allele. In contrast, higher PI was associated with faster progression in males.

CONCLUSION

A low percentage of individuals with AD in the community are taking cholinesterase inhibitors or memantine. This study suggests that women, particularly those with an APOE ɛ4 allele, may benefit the most from these medications. With the newly approved increased dose of donepezil, it will be imperative to determine whether a higher dose is needed in men or whether other factors warrant consideration.