Projections of Alzheimer's disease in the United States and the public health impact of delaying disease onset

Effect of music intervention on the cognitive and depression status of senior apartment residents in Taiwan

OBJECTIVE

To identify the effect of music intervention on cognitive function and depression status of residents in senior citizen apartments based on the existing evidence regarding music therapy.

METHODS

An experimental study was conducted from November 2008 to December 2009. Sixty healthy senior apartment residents over 65 years of age were recruited and separated into two groups. According to their opinion, 41 took part in the music intervention group and 19 in the comparison group. The music intervention involved Buddhist hymns. The short-term effects were evaluated based on the measurement of cognitive function and depression level using the Mini-Mental State Examination (MMSE) and the Geriatric Depression Scale-short form (GDS-SF) at the baseline, 1 month, and 4 months.

RESULTS

The means of the initial and the 1-month MMSE and GDS-SF scores did not differ between the two groups. The 4-month MMSE score significantly declined compared with the initial level in the comparison group, whereas no significant change was observed in the experimental group. Moreover, the 4-month GDS-SF score significantly improved in both groups compared with the initial level.

CONCLUSION

Music intervention may postpone cognitive decline in healthy residents preferring Buddhist hymns in the senior citizen apartments in 4 months follow-up, and intense contact with participants may improve their mood status.

Modeling test and treatment strategies for presymptomatic Alzheimer disease

OBJECTIVES

In this study, we developed a model of presymptomatic treatment of Alzheimer disease (AD) after a screening diagnostic evaluation and explored the circumstances required for an AD prevention treatment to produce aggregate net population benefit.

METHODS

Monte Carlo simulation methods were used to estimate outcomes in a simulated population derived from data on AD incidence and mortality. A wide variety of treatment parameters were explored. Net population benefit was estimated in aggregated QALYs. Sensitivity analyses were performed by individually varying the primary parameters.

FINDINGS

In the base-case scenario, treatment effects were uniformly positive, and net benefits increased with increasing age at screening. A highly efficacious treatment (i.e. relative risk 0.6) modeled in the base-case is estimated to save 20 QALYs per 1000 patients screened and 221 QALYs per 1000 patients treated.

CONCLUSIONS

Highly efficacious presymptomatic screen and treat strategies for AD are likely to produce substantial aggregate population benefits that are likely greater than the benefits of aspirin in primary prevention of moderate risk cardiovascular disease (28 QALYS per 1000 patients treated), even in the context of an imperfect treatment delivery environment.

Primary Prevention and Delay of Onset of AD/Dementia

Prevention in Alzheimer's disease and other dementias (AD/dementia) is defined on the basis of clinical states and their expressed symptoms. Primary prevention refers to delaying the development of the full-blown state of clinically expressed disease in normal individuals. Current primary prevention research is driven by evidence of AD/dementia protective factors that have emerged from epidemiological studies. The first randomized controlled trials (RCTs) of primary AD/dementia prevention have been designed to test the efficacy and safety of NSAIDs, hormonal therapy, antihypertensive drugs and antioxidants. The experience of these trials has indicated safety concerns as a key issue and highlighted significant design challenges in this type of research. These trials have required large sample sizes and unsustainable costs. There should be consideration given in future trials to enriching study samples with risk factors to increase progression rates to AD/dementia. Innovative strategies will also be needed to recruit and retain subjects given the long follow-up periods, modest perceived benefit and the potential for the risk-benefit ratio to change during the trial. It is foreseeable that regulatory authorities will be presented with primary prevention RCTs for approval and labelling, and that criteria to evaluate such evidence still need to be developed.

Diabetes in midlife and cognitive change over 20 years: a cohort study

BACKGROUND

Type 2 diabetes is associated with dementia risk, but evidence is limited for possible associations of diabetes and prediabetes with cognitive decline.

OBJECTIVE

To determine whether diabetes in midlife is associated with 20-year cognitive decline and to characterize long-term cognitive decline across clinical categories of hemoglobin A1c (HbA1c) levels.

DESIGN

Prospective cohort study.

SETTING

The community-based ARIC (Atherosclerosis Risk in Communities) study.

PARTICIPANTS

13,351 black and white adults aged 48 to 67 years at baseline (1990 to 1992).

MEASUREMENTS

Diabetes was defined by self-reported physician diagnosis or medication use or HbA1c level of 6.5% or greater. Undiagnosed diabetes, prediabetes, and glucose control in persons with diagnosed diabetes were defined by clinical categories of HbA1c level. Delayed word recall, digit symbol substitution, and word fluency tests were used to assess cognitive performance and were summarized with a global Z score.

RESULTS

Diabetes in midlife was associated with a 19% greater cognitive decline over 20 years (adjusted global Z-score difference, -0.15 [;95% CI, -0.22 to -0.08];) compared with no diabetes. Cognitive decline was significantly greater among persons with prediabetes (HbA1c level of 5.7% to 6.4%) than among those with an HbA1c level less than 5.7%. Participants with poorly controlled diabetes (HbA1c level ≥ 7.0%) had greater decline than those whose diabetes was controlled (adjusted global Z-score difference, -0.16; P = 0.071). Longer-duration diabetes was also associated with greater late-life cognitive decline (P for trend < 0.001). Rates of decline did not differ significantly between white and black persons (P for interaction = 0.44).

LIMITATION

Single HbA1c measurement at baseline, 1 test per cognitive domain, and potential geographic confounding of race comparisons.

CONCLUSION

Diabetes prevention and glucose control in midlife may protect against late-life cognitive decline.

PRIMARY FUNDING SOURCE

National Institutes of Health.

The impact of illiteracy on the assessment of cognition and dementia: a critical issue in the developing countries

BACKGROUND

Dementia and Alzheimer's disease (AD) is considered a major public health challenge in this decade and in the future. Early detection of AD through appropriate screening tools would be valuable approach in facing the burden of disease specifically in developing societies with insufficient resources. Selecting a screening tool which is non-expensive, non-invasive and implementable by trained primary healthcare providers is the first and probably the most important step in detecting high risk individuals. The goal of this review is to address the key issues in assessment tools in developing countries with a high level of illiteracy.

METHOD

We set about a review on literature on the subject of cognitive function assessment among minorities, people with low or no education, and people who live in underdeveloped societies. We also reviewed the studies on validation of such tests in a new society.

RESULTS

The most popular assessment tools are more or less biased by the level of education; not all of them are useful for any type of dementia as they assess only some domains of cognitive function.

CONCLUSION

Even though people with lower level of education have a higher rate of developing dementia, cognitive function cannot be accurately assessed because of limitations of current available tools. It is strongly suggested that special attention be paid to assess them by functional scales and activity daily living scales. For a more efficient assessment, cognitive tests can also benefit from illustrative questions, proverbs, metaphors, traditions, religious rituals and historical events.

2014 Alzheimer's disease facts and figures

This report discusses the public health impact of Alzheimer's disease (AD), including incidence and prevalence, mortality rates, costs of care, and overall effect on caregivers and society. It also examines the impact of AD on women compared with men. An estimated 5.2 million Americans have AD. Approximately 200,000 people younger than 65 years with AD comprise the younger onset AD population; 5 million are age 65 years or older. By mid-century, fueled in large part by the baby boom generation, the number of people living with AD in the United States is projected to grow by about 9 million. Today, someone in the country develops AD every 67 seconds. By 2050, one new case of AD is expected to develop every 33 seconds, or nearly a million new cases per year, and the total estimated prevalence is expected to be 13.8 million. In 2010, official death certificates recorded 83,494 deaths from AD, making AD the sixth leading cause of death in the United States and the fifth leading cause of death in Americans aged 65 years or older. Between 2000 and 2010, the proportion of deaths resulting from heart disease, stroke, and prostate cancer decreased 16%, 23%, and 8%, respectively, whereas the proportion resulting from AD increased 68%. The actual number of deaths to which AD contributes (or deaths with AD) is likely much larger than the number of deaths from AD recorded on death certificates. In 2014, an estimated 700,000 older Americans will die with AD, and many of them will die from complications caused by AD. In 2013, more than 15 million family members and other unpaid caregivers provided an estimated 17.7 billion hours of care to people with AD and other dementias, a contribution valued at more than $220 billion. Average per-person Medicare payments for services to beneficiaries aged 65 years and older with AD and other dementias are more than two and a half times as great as payments for all beneficiaries without these conditions, and Medicaid payments are 19 times as great. Total payments in 2014 for health care, long-term care, and hospice services for people aged 65 years and older with dementia are expected to be $214 billion. AD takes a stronger toll on women than men. More women than men develop the disease, and women are more likely than men to be informal caregivers for someone with AD or another dementia. As caregiving responsibilities become more time consuming and burdensome or extend for prolonged durations, women assume an even greater share of the caregiving burden. For every man who spends 21 to more than 60 hours per week as a caregiver, there are 2.1 women. For every man who lives with the care recipient and provides around-the-clock care, there are 2.5 women. In addition, for every man who has provided caregiving assistance for more than 5 years, there are 2.3 women.

Impact of sleep on the risk of cognitive decline and dementia

PURPOSE OF REVIEW

Trouble falling or staying asleep, poor sleep quality, and short or long sleep duration are gaining attention as potential risk factors for cognitive decline and dementia, including Alzheimer's disease. Sleep-disordered breathing has also been linked to these outcomes. Here, we review recent observational and experimental studies investigating the effect of poor sleep on cognitive outcomes and Alzheimer's disease, and discuss possible mechanisms.

RECENT FINDINGS

Observational studies with self-report and objective sleep measures (e.g. wrist actigraphy, polysomnography) support links between disturbed sleep and cognitive decline. Several recently published studies demonstrate associations between sleep variables and measures of Alzheimer's disease pathology, including cerebrospinal fluid measures of Aβ and PET measures of Aβ deposition. In addition, experimental studies suggest that sleep loss alters cerebrospinal fluid Aβ dynamics, decrements in slow-wave sleep may decrease the clearance of Aβ from the brain, and hypoxemia characteristic of sleep-disordered breathing increases Aβ production.

SUMMARY

Findings indicate that poor sleep is a risk factor for cognitive decline and Alzheimer's disease. Although mechanisms underlying these associations are not yet clear, healthy sleep appears to play an important role in maintaining brain health with age, and may play a key role in Alzheimer's disease prevention.

Impacto econômico da doença de Alzheimer no Brasil: é possível melhorar a assistência e reduzir custos?

O objetivo deste estudo foi discutir dados relativos aos custos da Doença de Alzheimer (DA) e as iniciativas assistenciais para reduzir custos e auxiliar a família e os cuidadores no manejo com a doença. O fator de maior custo para as pessoas com DA leve foi o do tempo do cuidador não remunerado, enquanto que para aqueles com a doença em estágio avançado foi o dos cuidados relativos à institucionalização. Frente a esse panorama a literatura propõe a adoção de modelos de atenção que maximizem a independência funcional do idoso e a manutenção de suas habilidades, como a implantação do Centro Dia para Idosos e de programas de reabilitação e amparo ao idoso e família. Esses modelos de atenção precisam ser discutidos, estruturados e implantados na realidade brasileira.

An empirically derived composite cognitive test score with improved power to track and evaluate treatments for preclinical Alzheimer's disease

BACKGROUND

There is growing interest in the evaluation of preclinical Alzheimer's disease (AD) treatments. As a result, there is a need to identify a cognitive composite that is sensitive to track preclinical AD decline to be used as a primary endpoint in treatment trials.

METHODS

Longitudinal data from initially cognitively normal, 70- to 85-year-old participants in three cohort studies of aging and dementia from the Rush Alzheimer's Disease Center were examined to empirically define a composite cognitive endpoint that is sensitive to detect and track cognitive decline before the onset of cognitive impairment. The mean-to-standard deviation ratios (MSDRs) of change over time were calculated in a search for the optimal combination of cognitive tests/subtests drawn from the neuropsychological battery in cognitively normal participants who subsequently progressed to clinical stages of AD during 2- and 5-year periods, using data from those who remained unimpaired during the same period to correct for aging and practice effects. Combinations that performed well were then evaluated for representation of relevant cognitive domains, robustness across individual years before diagnosis, and occurrence of selected items within top performing combinations.

RESULTS

The optimal composite cognitive test score comprised seven cognitive tests/subtests with an MSDR = 0.964. By comparison, the most sensitive individual test score was Logical Memory Delayed Recall with an MSDR = 0.64.

CONCLUSIONS

We have identified a composite cognitive test score representing multiple cognitive domains that has improved power compared with the most sensitive single test item to track preclinical AD decline and evaluate preclinical AD treatments. We are confirming the power of the composite in independent cohorts and with other analytical approaches, which may result in refinements, have designated it as the primary endpoint in the Alzheimer's Prevention Initiative's preclinical treatment trials for individuals at high imminent risk for developing symptoms due to late-onset AD.

25-vitamin D, 1,25-vitamin D, parathyroid hormone, fibroblast growth factor-23 and cognitive function in men with advanced CKD: a veteran population

Abstract. Cognitive impairment is common in advanced chronic kidney disease (CKD), but little is known about its relation with abnormalities in mineral metabolism. Methods: The longitudinal association between plasma 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)2D), intact parathyroid hormone (iPTH), and fibroblast growth factor-23 (FGF-23) levels and cognitive function was assessed in 605 patients (67 ± 12 years) with advanced CKD not requiring dialysis (n = 247) or end-stage renal disease (ESRD; n = 358) who participated in the Homocysteine Study Cognitive Function Substudy (HOSTCOG)). Cognitive function was assessed using the Telephone Interview for Cognitive Status-modified (TICSm; mean follow-up 3.1 years) and associated with baseline mineral metabolite levels using linear regression analyses. Results: In unadjusted analyses, increasing log 1,25(OH)2D and decreasing log iPTH and FGF-23 levels were associated with worse cognitive status (p < 0.05). In fully adjusted multivariate analyses, the associations were no longer significant. Log 25(OH)D levels were not associated with cognitive function in unadjusted or adjusted analyses. Results were similar when analyzed by tertile or separately within CKD and ESRD groups. Conclusions: These results suggest that mineral metabolism dysregulation does not mediate the impairment in cognitive function common in advanced CKD.

Molecular imaging in genetics

Neuroimaging is a potentially valuable tool to link individual differences in the human genome to structure and functional variations, narrowing the gaps in the casual chain from a given genetic variation to a brain disorder. Because genes are not usually expressed at the level of mental behavior, but are mediated by their molecular and cellular effects, molecular imaging could play a key role. This article reviews the literature using molecular imaging as an intermediate phenotype and/or biomarker for illness related to certain genetic alterations, focusing on the most common neurodegenerative disorders, Alzheimer's disease (AD) and Parkinson disease.

Potential for primary prevention of Alzheimer's disease: an analysis of population-based data

BACKGROUND

Recent estimates suggesting that over half of Alzheimer's disease burden worldwide might be attributed to potentially modifiable risk factors do not take into account risk-factor non-independence. We aimed to provide specific estimates of preventive potential by accounting for the association between risk factors.

METHODS

Using relative risks from existing meta-analyses, we estimated the population-attributable risk (PAR) of Alzheimer's disease worldwide and in the USA, Europe, and the UK for seven potentially modifiable risk factors that have consistent evidence of an association with the disease (diabetes, midlife hypertension, midlife obesity, physical inactivity, depression, smoking, and low educational attainment). The combined PAR associated with the risk factors was calculated using data from the Health Survey for England 2006 to estimate and adjust for the association between risk factors. The potential of risk factor reduction was assessed by examining the combined effect of relative reductions of 10% and 20% per decade for each of the seven risk factors on projections for Alzheimer's disease cases to 2050.

FINDINGS

Worldwide, the highest estimated PAR was for low educational attainment (19·1%, 95% CI 12·3-25·6). The highest estimated PAR was for physical inactivity in the USA (21·0%, 95% CI 5·8-36·6), Europe (20·3%, 5·6-35·6), and the UK (21·8%, 6·1-37·7). Assuming independence, the combined worldwide PAR for the seven risk factors was 49·4% (95% CI 25·7-68·4), which equates to 16·8 million attributable cases (95% CI 8·7-23·2 million) of 33·9 million cases. However, after adjustment for the association between the risk factors, the estimate reduced to 28·2% (95% CI 14·2-41·5), which equates to 9·6 million attributable cases (95% CI 4·8-14·1 million) of 33·9 million cases. Combined PAR estimates were about 30% for the USA, Europe, and the UK. Assuming a causal relation and intervention at the correct age for prevention, relative reductions of 10% per decade in the prevalence of each of the seven risk factors could reduce the prevalence of Alzheimer's disease in 2050 by 8·3% worldwide.

INTERPRETATION

After accounting for non-independence between risk factors, around a third of Alzheimer's diseases cases worldwide might be attributable to potentially modifiable risk factors. Alzheimer's disease incidence might be reduced through improved access to education and use of effective methods targeted at reducing the prevalence of vascular risk factors (eg, physical inactivity, smoking, midlife hypertension, midlife obesity, and diabetes) and depression.

FUNDING

National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care for Cambridgeshire and Peterborough.

Personality and cognitive decline in the Baltimore Epidemiologic Catchment Area follow-up study

OBJECTIVE

To determine the association between personality domains and 11-year cognitive decline in a sample from a population-based study.

METHOD

Data from Waves 3 (1993-1996) and 4 (2003-2004) of the Baltimore cohort of the Epidemiologic Catchment Area (ECA) study were used for analyses. The sample included 561 adults (mean age ± SD: 45.2 ± 10.78 years) who completed the NEO Personality Inventory-Revised prior to Wave 4. Participants also completed the Mini-Mental State Examination (MMSE) and immediate and delayed word recall tests at Wave 3, and at Wave 4, 10.9 ± 0.6 years later.

RESULTS

In models adjusted for baseline cognitive performance, demographic characteristics, medical conditions, depressive symptoms, and psychotropic medication use, each 10-point increase in Neuroticism T-scores was associated with a 0.15-point decrease in MMSE scores (B = -0.15, 95% confidence interval [CI]: -0.30, -0.01), whereas each 10-point increase in Conscientiousness T-scores was associated with a 0.18-point increase on the MMSE (B = 0.18, 95% CI: 0.04, 0.32) and a 0.21-point increase in immediate recall (B = 0.21, 95% CI: 0.003, 0.41) between baseline and follow-up.

CONCLUSION

Findings suggest that greater Neuroticism is associated with decline, and greater Conscientiousness is associated with improvement in performance on measures of general cognitive function and memory in adults. Further studies are needed to determine the extent to which personality traits in midlife are associated with clinically significant cognitive outcomes in older adults, such as mild cognitive impairment and dementia, and to identify potential mediators of the association between personality and cognitive trajectories.

Invited commentary: how exposure to air pollution may shape dementia risk, and what epidemiology can say about it

The number of Americans with Alzheimer's disease (AD) dementia is expected to triple by 2050. No effective treatments exist, and prevention research has focused on behaviors and medical conditions, which have been difficult to modify at the population level. Cardiovascular disease epidemiology can inform the search for AD risk factors; exposure to fine particulate matter (PM) air pollution increases cardiovascular risk, pollutant regulations appear to reduce cardiovascular deaths, and vascular pathology influences dementia risk. In this issue of the Journal, Ailshire and Crimmins (Am J Epidemiol. 2014;180(4):359-366) report analyses of data from 14,000 older adults living across the United States, indicating an inverse association between exposure to PM and cognitive function, an outcome related to AD by virtue of the long period of cognitive decline that precedes clinical disease. Their work joins a growing body of data linking PM exposure to AD risk. If these data reflect causality, PM exposure would be 1 of few AD risk factors that are not only widespread, but that also can be modified at the population level using regulatory intervention. Active collaboration between air pollution and dementia epidemiologists will be critical for refining the available evidence and filling fundamental gaps, including the lack of studies on AD itself.

The recent decline in prevalence of dementia in developed countries: implications for prevention in the Republic of Korea

With the rapid aging of the population in Korea, the number of older people with dementia is projected to increase, forecasting an epidemic of dementia. Recent trends in dementia in several western countries, however, depict a gradual decline in prevalence and incidence. This decrease has been attributed to an improvement in education and living environments, engagement in healthy behaviors, and reduction in the prevalence of vascular risk factors. In Korea, however, trends in modifiable risk factors do not favor an optimistic outlook due to the continuous increase in the prevalence of hypertension, diabetes mellitus, and obesity. Given these observations, there is much to be gained through the promotion of healthy lifestyles. Moreover, public health resources need to be directed toward the provision of health promotion and preventive services, control and management of vascular risk factors, and improvement in the standard of living. Nationwide initiatives to develop and implement policies and strategies to protect cognitive health throughout the lifespan should be considered a public health priority.

The search for early markers of AD: hippocampal atrophy and memory deficits

There is increasing interest in finding markers of Alzheimer's disease (AD) that are discriminative even at an early, pre-dementia stage. This interest is driven partly by a desire to improve clinical diagnosis in more mildly affected individuals, and also by the recent paradigm shift in thinking about clinical trials for AD. This shift is a result of concern that the recent failures of high-profile clinical trials conducted in patients with mild to moderate AD may have been because therapy was “too little, too late.” The implication being that if only treatments had been trialled earlier they would have had a greater chance of success. Certainly, lessons from other aspects of medicine have shown that treatments may be most, or in some cases only, effective if given early in disease. If we did have therapies that could slow disease progression at a very early stage that would increase the interest in early markers of disease. Ideally, such therapies would be given when the minimum of functional decline and irreversible neuronal loss had already occurred. From economic and public health standpoints, delaying symptom onset would be very important: a delay of five years has been estimated to reduce projections for prevalence of symptomatic AD by about 50% (Brookmeyer et al. , 1998).

Pharmacology of conjugated equine estrogens: efficacy, safety and mechanism of action

Oral conjugated equine estrogens (CEE) are the most used estrogen formulation for postmenopausal hormone therapy either alone or in combination with a progestin. CEE is most commonly used for the management of early menopausal symptoms such as hot flashes, vaginitis, insomnia, and mood disturbances. Additionally, if used at the start of the menopausal phase (age 50-59 years), CEE prevents osteoporosis and may in some women reduce the risk of cardiovascular disease (CVD) and Alzheimer's disease (AD). There appears to be a common mechanism through which estrogens can protect against CVD and AD. CEE is a natural formulation of an extract prepared from pregnant mares' urine. The product monogram lists the presence of only 10 estrogens consisting of the classical estrogens, estrone and 17β-estradiol, and a group of unique ring B unsaturated estrogens such as equilin and equilenin. The ring B unsaturated estrogens are formed by an alternate steroidogenic pathway in which cholesterol is not an obligatory intermediate. Both the route of administration and structure of these estrogens play a role in the overall pharmacology of CEE. In contrast to 17β-estradiol, ring B unsaturated estrogens express their biological effects mainly mediated by the estrogen receptor β and not the estrogen receptor α. All estrogen components of CEE are antioxidants, and some ring B unsaturated estrogens have several fold greater antioxidant activity than estrone and 17β-estradiol. The cardioprotective and neuroprotective effects of CEE appear to be, to some extent, due to its ability to prevent the formation of oxidized LDL and HDL, and by inhibiting or modulating some of the key proteases involved in programmed cell death (apoptosis) induced by the excess neurotransmitter glutamate and other neurotoxins. Selective combinations of ring B unsaturated estrogens have the potential of being developed as novel therapeutic agents for the prevention of cardiovascular disease and Alzheimer's disease in both aging women and men. This article is part of a Special Issue entitled 'Menopause'.

The cognition battery of the NIH toolbox for assessment of neurological and behavioral function: validation in an adult sample

This study introduces a special series on validity studies of the Cognition Battery (CB) from the U.S. National Institutes of Health Toolbox for the Assessment of Neurological and Behavioral Function (NIHTB) (Gershon, Wagster et al., 2013) in an adult sample. This first study in the series describes the sample, each of the seven instruments in the NIHTB-CB briefly, and the general approach to data analysis. Data are provided on test-retest reliability and practice effects, and raw scores (mean, standard deviation, range) are presented for each instrument and the gold standard instruments used to measure construct validity. Accompanying papers provide details on each instrument, including information about instrument development, psychometric properties, age and education effects on performance, and convergent and discriminant construct validity. One study in the series is devoted to a factor analysis of the NIHTB-CB in adults and another describes the psychometric properties of three composite scores derived from the individual measures representing fluid and crystallized abilities and their combination. The NIHTB-CB is designed to provide a brief, comprehensive, common set of measures to allow comparisons among disparate studies and to improve scientific communication.

Plasma-Enabled Carbon Nanostructures for Early Diagnosis of Neurodegenerative Diseases

Carbon nanostructures (CNs) are amongst the most promising biorecognition nanomaterials due to their unprecedented optical, electrical and structural properties. As such, CNs may be harnessed to tackle the detrimental public health and socio-economic adversities associated with neurodegenerative diseases (NDs). In particular, CNs may be tailored for a specific determination of biomarkers indicative of NDs. However, the realization of such a biosensor represents a significant technological challenge in the uniform fabrication of CNs with outstanding qualities in order to facilitate a highly-sensitive detection of biomarkers suspended in complex biological environments. Notably, the versatility of plasma-based techniques for the synthesis and surface modification of CNs may be embraced to optimize the biorecognition performance and capabilities. This review surveys the recent advances in CN-based biosensors, and highlights the benefits of plasma-processing techniques to enable, enhance, and tailor the performance and optimize the fabrication of CNs, towards the construction of biosensors with unparalleled performance for the early diagnosis of NDs, via a plethora of energy-efficient, environmentally-benign, and inexpensive approaches.

Analyses of the similarity and difference of global gene expression profiles in cortex regions of three neurodegenerative diseases: sporadic Creutzfeldt-Jakob disease (sCJD), fatal familial insomnia (FFI), and Alzheimer's disease (AD)

Neurodegenerative disease is a general designation for the disorders that are progressive loss of structure or function and final death of neurons, including Alzheimer's, Parkinson's, Huntington's, prion diseases, etc. In this study, we comparatively analyzed 21 individual microarray data sets of the cortex tissues from 11 sporadic Creutzfeldt-Jakob disease (sCJD), 3 fatal familial insomnia (FFI), 3 Alzheimer's disease (AD), and 4 normal controls. After normalization, a collection of 730 differently expressed sets (DESets) were obtained by comparison of the data of three diseases with their original controls. Principal component analysis (PCA) showed a background-related distribution within the groups of FFI, AD, and normal control, but two apparently different subgroups within the group of sCJD were observed. Review of the clinical materials of 11 sCJD patients identified the difference in brain PrP(Sc) deposits between two subgroups. Hierarchical cluster analysis illustrated the relatively independent clusters of normal controls, FFIs, six sCJD cases (subgroup 1) with more PrP(Sc) deposits, respectively, while an overlapped cluster of five cases of sCJD2 (subgroup 2) with less PrP(Sc) deposits and AD patients. Despite of the presence of special gene expressions, many common features were found among those neurodegenerative diseases. The most commonly changed biological processes (BPs) were signal transduction, synaptic transmission, and neuropeptide signaling pathway. The most commonly changed pathways were MAPK signaling pathway, Parkinson's disease, and oxidative phosphorylation. Our data here provide the similarity and difference in global gene expressions among the patients with sCJD, FFI, and AD, which may help to understand the common mechanism of neurodegenerative diseases.

Potential benefits of mindfulness-based interventions in mild cognitive impairment and Alzheimer's disease: an interdisciplinary perspective

The present article is based on the premise that the risk of developing Alzheimer's disease (AD) from its prodromal phase (mild cognitive impairment; MCI) is higher when adverse factors (e.g., stress, depression, and metabolic syndrome) are present and accumulate. Such factors augment the likelihood of hippocampal damage central in MCI/AD aetiology, as well as compensatory mechanisms failure triggering a switch toward neurodegeneration. Because of the devastating consequences of AD, there is a need for early interventions that can delay, perhaps prevent, the transition from MCI to AD. We hypothesize that mindfulness-based interventions (MBI) show promise with regard to this goal. The present review discusses the associations between modifiable adverse factors and MCI/AD decline, MBI's impacts on adverse factors, and the mechanisms that could underlie the benefits of MBI. A schematic model is proposed to illustrate the course of neurodegeneration specific to MCI/AD, as well as the possible preventive mechanisms of MBI. Whereas regulation of glucocorticosteroids, inflammation, and serotonin could mediate MBI's effects on stress and depression, resolution of the metabolic syndrome might happen through a reduction of inflammation and white matter hyperintensities, and normalization of insulin and oxidation. The literature reviewed in this paper suggests that the main reach of MBI over MCI/AD development involves the management of stress, depressive symptoms, and inflammation. Future research must focus on achieving deeper understanding of MBI's mechanisms of action in the context of MCI and AD. This necessitates bridging the gap between neuroscientific subfields and a cross-domain integration between basic and clinical knowledge.

Awareness of Aging: Theoretical Considerations on an Emerging Concept

Humans are able to reflect on and interpret their own aging. Thus, as individuals grow older, calendar age may become increasingly a subjective variable. This theoretical paper proposes the concept of Awareness of Aging (AoA) as a superordinate construct that can serve an integrative function in developmental research on subjective aging. It is argued that the AoA construct can incorporate the theoretical components of other existing concepts by acknowledging that judgments of subjective aging tend to be made on an awareness continuum ranging from pre-conscious/implicit to conscious/explicit. We also argue that processes of AoA are inherently self-related processes and that AoA is a particular aspect of self-awareness that results in specific aging-related self-knowledge. Over time, aging individuals incorporate this self-knowledge into their self-concept and personal identity. We provide theoretical evidence showing that although all major theories of adult development and aging draw on phenomena related to AoA, the explicit incorporation of aging-related awareness processes has been missing. We also provide an overarching framework to illustrate in a heuristic way how AoA in combination and interaction with other influences affects developmental outcomes. Finally, we argue that attention to AoA-related processes has a number of societal and applied implications and thereby addresses issues of applied developmental psychology.

Correlates of quality of life for individuals with dementia living at home: the role of home environment, caregiver, and patient-related characteristics

OBJECTIVES

To examine prevalence of modifiable risk factors and their contribution to patient quality of life (QoL) as rated by dementia patients and family caregivers.

DESIGN

Cross-sectional.

SETTING

Home environment.

PARTICIPANTS

88 patients and their caregivers.

MEASUREMENTS

Modifiable characteristics of home environments, patients, and caregivers were observed or obtained through interview. Demographics and ratings of patients' QoL were obtained from patients and caregivers.

RESULTS

Patients had mean Mini-mental Status Examination (MMSE) score = 17.7 ± 4.6, (range: 10-28) on an average 7.7 ± 2.4 neuropsychiatric behaviors, 6.0 ± 3.1 health conditions and moderate functional challenges; 70.7% (N = 58) had fall risk; 60.5% (N = 52) had sleep problems at least once weekly; and 42.5% (N = 37) had pain. An average of 8.1 ± 5.2 home hazards and 5.4 ± 4.1 adaptations were observed; 51.7% had unmet device/navigation needs. Patients' and caregivers' QoL ratings were unrelated to MMSE; and patients' self-rated QoL was higher than rated by caregivers. Number of health conditions and unmet device/navigation needs were inversely associated with patient self-rated QoL, and number of health conditions, frequency of behaviors, and level of negative communications were inversely associated with caregiver's assessment of patient QoL. Positive endorsement of caregiving was positively associated with caregiver's appraisal of patient QoL. Other factors were unrelated.

CONCLUSIONS

Most patients lived at home with high fall risk, unmanaged behavioral symptoms, pain, sleep disturbances, environmental challenges, and multiple hazards. Except for health, factors associated with lower QoL differed for patients and caregivers. Results suggest need to improve QoL by addressing modifiable risk factors and tailoring interventions to patient and caregiver perspectives.

Age-specific incidence rates for dementia and Alzheimer disease in NIA-LOAD/NCRAD and EFIGA families: National Institute on Aging Genetics Initiative for Late-Onset Alzheimer Disease/National Cell Repository for Alzheimer Disease (NIA-LOAD/NCRAD) and Estudio Familiar de Influencia Genetica en Alzheimer (EFIGA)

IMPORTANCE

Late-onset Alzheimer disease (LOAD), defined as onset of symptoms after age 65 years, is the most common form of dementia. Few reports investigate incidence rates in large family-based studies in which the participants were selected for family history of LOAD.

OBJECTIVE

To determine the incidence rates of dementia and LOAD in unaffected members in the National Institute on Aging Genetics Initiative for Late-Onset Alzheimer Disease/National Cell Repository for Alzheimer Disease (NIA-LOAD/NCRAD) and Estudio Familiar de Influencia Genetica en Alzheimer (EFIGA) family studies.

DESIGN, SETTING, AND PARTICIPANTS

Families with 2 or more affected siblings who had a clinical or pathological diagnosis of LOAD were recruited as a part of the NIA-LOAD/NCRAD Family Study. A cohort of Caribbean Hispanics with familial LOAD was recruited in a different study at the Taub Institute for Research on Alzheimer's Disease and the Aging Brain in New York and from clinics in the Dominican Republic as part of the EFIGA study.

MAIN OUTCOMES AND MEASURES

Age-specific incidence rates of LOAD were estimated in the unaffected family members in the NIA-LOAD/NCRAD and EFIGA data sets. We restricted analyses to families with follow-up and complete phenotype information, including 396 NIA-LOAD/NCRAD and 242 EFIGA families. Among the 943 at-risk family members in the NIA-LOAD/NCRAD families, 126 (13.4%) developed dementia, of whom 109 (86.5%) met criteria for LOAD. Among 683 at-risk family members in the EFIGA families, 174 (25.5%) developed dementia during the study period, of whom 145 (83.3%) had LOAD.

RESULTS

The annual incidence rates of dementia and LOAD in the NIA-LOAD/NCRAD families per person-year were 0.03 and 0.03, respectively, in participants aged 65 to 74 years; 0.07 and 0.06, respectively, in those aged 75 to 84 years; and 0.08 and 0.07, respectively, in those 85 years or older. Incidence rates in the EFIGA families were slightly higher, at 0.03 and 0.02, 0.06 and 0.05, 0.10 and 0.08, and 0.10 and 0.07, respectively, in the same age groups. Contrasting these results with the population-based estimates, the incidence was increased by 3-fold for NIA-LOAD/NCRAD families (standardized incidence ratio, 3.44) and 2-fold among the EFIGA compared with the NIA-LOAD/NCRAD families (1.71).

CONCLUSIONS AND RELEVANCE

The incidence rates for familial dementia and LOAD in the NIA-LOAD/NCRAD and EFIGA families are significantly higher than population-based estimates. The incidence rates in all groups increase with age. The higher incidence of LOAD can be explained by segregation of Alzheimer disease-related genes in these families or shared environmental risks.

Older age at retirement is associated with decreased risk of dementia

To test the hypothesis that age at retirement is associated with dementia risk among self-employed workers in France, we linked health and pension databases of self-employed workers and we extracted data of those who were still alive and retired as of December 31st 2010. Dementia cases were detected in the database either through the declaration of a long-term chronic disease coded as Alzheimer's disease and other dementia (International Classification of Disease codes G30, F00, F01, F03) or through the claim for reimbursement of one of the anti-dementia drugs. Data were analyzed using Cox proportional hazard model adjusting for potential confounders. Among the 429,803 retired self-employed workers alive on December 31st 2010, prevalence of dementia was 2.65 %. Multivariable analyses showed that the hazard ratio of dementia was 0.968 [95 % confidence interval = (0.962-0.973)] per each extra year of age at retirement. After excluding workers who had dementia diagnosed within the 5 years following retirement, the results remained unchanged and highly significant (p < 0.0001). We show strong evidence of a significant decrease in the risk of developing dementia associated with older age at retirement, in line with the "use it or lose it" hypothesis. Further evidence is necessary to evaluate whether this association is causal, but our results indicate the potential importance of maintaining high levels of cognitive and social stimulation throughout work and retiree life.

The source of cognitive complaints predicts diagnostic conversion differentially among nondemented older adults

OBJECTIVE

The objective of this study was to compare whether different sources of cognitive complaint (i.e., subjective and informant) predict diagnostic conversion in nondemented older adults.

METHODS

Participants from the National Alzheimer's Coordinating Center had a baseline diagnosis of normal cognition (NC; n = 4414; mean age, 73 ± 8 years; 69% female) or mild cognitive impairment (MCI; n = 1843; mean age, 74 ± 8 years; 52% female). Multinomial logistic regression related baseline cognitive complaint (no complaint, self only, informant only, or both self and informant) to diagnostic outcome (reversion, stable, or conversion).

RESULTS

At follow-up, 14% of NC participants converted to MCI/dementia (3.5 ± 1.8 years), and 41% of MCI participants converted to dementia (3.0 ± 1.6 years). Among NC participants, self complaint only (odds ratio [OR], 2.1; 99% confidence interval (CI),1.5-2.9; P < .001), informant complaint only (OR, 2.2; 99% CI, 1.2-3.9; P < .001), and both self and informant complaint (OR, 4.2; 99% CI, 2.9-6.0; P < .001) were associated with diagnostic conversion compared with no complaint. Among participants with MCI-compared with no complaint, informant complaint only (OR, 2.2; 99% CI, 1.2-4.3, P = .002), and both self and informant complaint (OR, 2.9; 99% CI, 1.8-4.8; P < .001)-were associated with conversion.

CONCLUSIONS

Cognitive complaints are related to conversion among nondemented older adults. Complaint from both (i.e. mutual complaint) sources was most predictive of diagnostic outcome, followed by informant complaint, highlighting the need for obtaining informant corroboration to enhance prognosis and distinguish underlying pathological processes from normal cognitive aging. Self complaint was related inconsistently to diagnostic outcome.

Fluorogenic resveratrol-confined graphene oxide for economic and rapid detection of Alzheimer's disease

Developing an effective means for the real-time probing of amyloid β (Aβ) that is closely implicated in Alzheimer's disease (AD) could help better understand and monitor the disease. Here we describe an economic approach based on the simple composition of a natural product, resveratrol (Res), with graphene oxide (GO) for the rapid, fluorogenic recognition of Aβ. The Res@GO composite has proved specific for Aβ over a range of proteins and ions, and could sensitively capture both Aβ monomers and fibers in a physiological buffer solution within only 3 min. The composite can also fluorescently image amyloid deposits in a mouse brain section within 30 min. This new protocol is much cheaper and more timesaving than the conventional immunofluorescence staining technique employed clinically, providing an economic tool for the concise detection of AD.

Herbal medicine in the treatment of Alzheimer's disease

Associated with the aging of our world population is a sharp increase in the incidence of Alzheimer's disease, which not only poses a significant health issue but also presents a serious social problem. Although pharmacological treatments were developed based on existing hypotheses, the disease pathogenesis remains to be fully elucidated. Given the complexity of Alzheimer's disease, Chinese herbal medicine appears to have therapeutic potential for Alzheimer's disease through multi-target and multi-pathway approach at cellular and molecular levels and holistic adjustment of the body at organ system levels. Recently, a significant breakthrough has been made in the research of Chinese medicine for Alzheimer's disease. In this article, we review the experimental research progress in understanding how Chinese medicine could be used for the treatment of Alzheimer's disease.

Effects of metabolic syndrome, apolipoprotein E, and CYP46 on cognition among Taiwanese Chinese

The combined effects of metabolic syndrome and the apolipoprotein E and CYP46 genotypes on the risk of cognitive decline has yet to be determined among Taiwanese Chinese. Two hundred and nine mentally healthy middle-aged and older adults were assessed for metabolic syndrome, cognitive function using the Cognitive Abilities Screening Instrument, Mini-Mental State Examination, ApoE, and CYP46 polymorphisms. There were no differences in cognitive performance, ApoE epsilon4 (ε4) carrier status, or CYP46 genotypes between participants with and those without metabolic syndrome. The ε4 carriers and participants with the AA allele of CYP46 had significantly lower mental manipulation score. Metabolic syndrome and ε4 had synergistic effects on cognitive decline. Therefore, the ε4 carriers and participants with the AA allele of CYP46 have decreased mental manipulation ability. The metabolic syndrome may play a role in subtle cognitive dysfunction in ε4 carriers among Taiwanese Chinese.

Effect of flavonoids on learning, memory and neurocognitive performance: relevance and potential implications for Alzheimer's disease pathophysiology

Recent evidence has indicated that a group of plant-derived compounds known as flavonoids may exert particularly powerful actions on mammalian cognition and may reverse age-related declines in memory and learning. In addition, growing evidence is also suggestive that flavonoids may delay the development of Alzheimer's disease-like pathology, suggestive of potential dietary strategies in dementia. Although these low-molecular-weight phytochemicals are absorbed to only a limited degree, they have been found to counteract age-related cognitive declines possibly via their ability to interact with the cellular and molecular architecture of the brain responsible for memory. However, the majority of the research has been carried out at rather supraphysiological concentrations and only a few studies have investigated the neuromodulatory effects of physiologically attainable flavonoid concentrations. This review will summarize the evidence for the effects of flavonoids and their metabolites in age-related cognitive decline and Alzheimer's disease. Mechanisms of actions will be discussed and include those activating signalling pathways critical in controlling synaptic plasticity, reducing neuroinflammation and inducing vascular effects potentially capable of causing new nerve cell growth in the hippocampus. Altogether, these processes are known to be important in maintaining optimal neuronal function, to limit neurodegeneration and to prevent or reverse age-dependent deteriorations in cognitive performance.

Associations of objectively and subjectively measured sleep quality with subsequent cognitive decline in older community-dwelling men: the MrOS sleep study

STUDY OBJECTIVES

To examine associations of objectively and subjectively measured sleep with subsequent cognitive decline.

DESIGN

A population-based longitudinal study.

SETTING

Six centers in the United States.

PARTICIPANTS

Participants were 2,822 cognitively intact community-dwelling older men (mean age 76.0 ± 5.3 y) followed over 3.4 ± 0.5 y.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

OBJECTIVELY MEASURED SLEEP PREDICTORS FROM WRIST ACTIGRAPHY: total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), number of long wake episodes (LWEP). Self-reported sleep predictors: sleep quality (Pittsburgh Sleep Quality Index [PSQI]), daytime sleepiness (Epworth Sleepiness Scale [ESS]), TST. Clinically significant cognitive decline: five-point decline on the Modified Mini-Mental State examination (3MS), change score for the Trails B test time in the worse decile. Associations of sleep predictors and cognitive decline were examined with logistic regression and linear mixed models. After multivariable adjustment, higher levels of WASO and LWEP and lower SE were associated with an 1.4 to 1.5-fold increase in odds of clinically significant decline (odds ratio 95% confidence interval) Trails B test: SE < 70% versus SE ≥ 70%: 1.53 (1.07, 2.18); WASO ≥ 90 min versus WASO < 90 min: 1.47 (1.09, 1.98); eight or more LWEP versus fewer than eight: 1.38 (1.02, 1.86). 3MS: eight or more LWEP versus fewer than eight: 1.36 (1.09, 1.71), with modest relationships to linear change in cognition over time. PSQI was related to decline in Trails B performance (3 sec/y per standard deviation increase).

CONCLUSIONS

Among older community-dwelling men, reduced sleep efficiency, greater nighttime wakefulness, greater number of long wake episodes, and poor self-reported sleep quality were associated with subsequent cognitive decline.

Economic analysis of opportunities to accelerate Alzheimer's disease research and development

The development of disease-modifying treatments for Alzheimer's disease (AD) faces a number of barriers. Among these are the lack of surrogate biomarkers, the exceptional size and duration of clinical trials, difficulties in identifying appropriate populations for clinical trials, and the limitations of monotherapies in addressing such a complex multifactorial disease. This study sets out to first estimate the consequent impact on the expected cost of developing disease-modifying treatments for AD and then to estimate the potential benefits of bringing together industry, academic, and government stakeholders to co-invest in, for example, developing better biomarkers and cognitive assessment tools, building out advanced registries and clinical trial-readiness cohorts, and establishing clinical trial platforms to investigate combinations of candidate drugs and biomarkers from the portfolios of multiple companies. Estimates based on interviews with experts on AD research and development suggest that the cost of one new drug is now $5.7 billion (95% confidence interval (CI) $3.7-9.5 billion) and could be reduced to $2.0 billion (95% CI $1.5-2.9 billion). The associated acceleration in the arrival of disease-modifying treatments could reduce the number of case years of dementia by 7.0 million (95% CI 4.4-9.4 million) in the United States from 2025 through 2040.

Genome-wide association studies in Alzheimer's disease: a review

Over the past decade, research aiming to disentangle the genetic underpinnings of late-onset Alzheimer’s disease has mostly focused on the identification of common variants through genome-wide association studies. The identification of several new susceptibility genes through these efforts has reinforced the importance of amyloid precursor protein and tau metabolism in the cause of the disease and has implicated immune response, inflammation, lipid metabolism, endocytosis/intracellular trafficking, and cell migration in the cause of the disease. Ongoing and future large-scale genome-wide association studies, translational studies, and next-generation whole genome or whole exome sequencing efforts, hold the promise to map the specific causative variants in these genes, to identify several additional risk variants, including rare and structural variants, and to identify novel targets for genetic testing, prevention, and treatment.

Cognitive lifestyle jointly predicts longitudinal cognitive decline and mortality risk

Cognitive lifestyle measures such as education, occupation, and social engagement are commonly associated with late-life cognitive ability although their associations with cognitive decline tend to be mixed. However, longitudinal analyses of cognition rarely account for death and dropout, measurement error of the cognitive phenotype, and differing trajectories for different population sub-groups. This paper applies a joint latent class mixed model (and a multi-state model in a sensitivity analysis) that accounts for these issues to a large (n = 3,653), population-based cohort, Paquid, to model the relationship between cognitive lifestyle and cognitive decline. Cognition was assessed over a 20-year period using the Mini-Mental State Examination. Three cognitive lifestyle variables were assessed: education, mid-life occupation, and late-life social engagement. The analysis identified four latent sub-populations with class-specific longitudinal cognitive decline and mortality risk. Irrespective of the cognitive trajectory, increased social engagement was associated with a decreased mortality risk. High education was associated with the most favourable cognitive trajectory, and after adjusting for cognitive decline, with an increased mortality risk. Mid-life occupational complexity was also associated with more favourable trajectories but not with mortality risk. To realistically examine the link between cognitive lifestyle and cognitive decline, complex statistical models are required. This paper applies and compares in a sensitivity analysis two such models, and shows education to be linked to a compression of cognitive morbidity irrespective of cognitive trajectory. Furthermore, a potentially modifiable variable, late-life social engagement is associated with a decreased mortality risk in all of the population sub-groups.

Active music therapy improves cognition and behaviour in chronic vascular encephalopathy: a case report

OBJECTIVES

This study describes the effects of active music therapy (AMT) on cognition and behaviour in chronic vascular encephalopathy.

DESIGN

A single case study investigated different cognitive and psycho-behavioural changes after AMT.

SETTING

An adult patient with memory, attention, and verbal fluency deficits associated with Vascular Cognitive Impairment-No Dementia (VCI-ND) was treated.

INTERVENTION

A four-months AMT course was based on creative and interactive music playing. Sixteen sessions were conducted simultaneously to the pharmacological therapy.

MAIN OUTCOMES MEASURES

Cognitive performances, mood, interpersonal interactions, and perceived abilities were assessed using standardized neuropsychological and psycho-behavioural measurements.

RESULTS

At baseline, the patient reported a tendency to feel tense, nervous, and angry and difficulties in memory and visuospatial performances, frequently accompanied by attention drops. The social network was a habitual component of the patient's life, but not a source of sharing of personal experiences, safety or comfort. Neuropsychological tests showed deficits in object and figure naming, verbal fluency, short and long-term verbal memory, short-term spatial memory, selective attention, and visuomotor coordination. After AMT, the cognitive profile significantly improved in attention, visuomotor coordination, and verbal and spatial memory. Such positive changes were confirmed at the three-months follow-up. An increase of the interpersonal interactions and consistent reduction of anxiety were also observed.

CONCLUSIONS

In selected patients with VCI-ND, a well-structured AMT intervention added to standard therapy may contribute in determining a stable improvement of cognitive and psycho-behavioural aspects. Controlled studies are needed to confirm these promising results.

Metal protein attenuating compounds for the treatment of Alzheimer's dementia

BACKGROUND

Alzheimer's dementia (AD) may be caused by the formation of extracellular senile plaques comprised of beta-amyloid (Aß). In vitro and mouse model studies have demonstrated that metal protein attenuating compounds (MPACs) promote the solubilisation and clearance of Aß.

OBJECTIVES

To evaluate the efficacy of metal protein attenuating compounds (MPACs) for the treatment of cognitive impairment due to Alzheimer's dementia.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group Specialized Register, on 29 July 2010 using the terms: Clioquinol OR PBT1 OR PBT2 OR "metal protein" OR MPACS OR MPAC.

SELECTION CRITERIA

Randomised double-blind trials in which treatment with an MPAC was administered to participants with Alzheimer's dementia in a parallel group comparison with placebo were included.

DATA COLLECTION AND ANALYSIS

Three review authors (RM, LJ, ELS) independently assessed the quality of trials according to the Cochrane Handbook for Systematic Reviews of Interventions.The primary outcome measure of interest was cognitive function (as measured by psychometric tests). The secondary outcome measures of interest were in the following areas: quality of life, functional performance, effect on carer, biomarkers, safety and adverse effects, and death.

MAIN RESULTS

Two MPAC trials were identified. One trial compared clioquinol (PBT1) with placebo in 36 patients and 32 had sufficient data for per protocol analysis. There was no statistically significant difference in cognition (as measured on the Alzheimer's Disease Assessment Scale - Cognition (ADAS-Cog)) between the active treatment and placebo groups at 36 weeks. The difference in mean change from baseline ADAS-Cog score in the clioquinol arm compared with the placebo arm at weeks 24 and 36 was a difference of 7.37 (95% confidence interval (CI) 1.51 to 13.24) and 6.36 (95% CI -0.50 to 13.23), respectively.There was no significant impact on non-cognitive symptoms or clinical global impression. One participant in the active treatment group developed neurological symptoms (impaired visual acuity and colour vision) which resolved on cessation of treatment and were possibly attributable to the drug.In the second trial a successor compound, PBT2, was compared with placebo in 78 participants with mild Alzheimer's dementia; all were included in the intention-to-treat analysis. There was no significant difference in the Neuropsychological Test Battery (NTB) composite or memory between placebo and PBT2 in the least squares mean change from baseline at week 12. However, two executive function component tests of the NTB showed significant improvement over placebo in the PBT2 250 mg group from baseline to week 12: category fluency test (2.8 words, 95% CI 0.1 to 5.4; P = 0.041) and trail making part B (-48.0 s, 95% CI -83.0 to -13.0; P = 0.009). In the executive factor Z score, the difference in least squares mean change from baseline at week 12 for PBT2 250 mg compared with placebo was 0·27 (0·01 to 0·53; p=0·042).There was no significant effect on cognition on Mini-Mental State Examination (MMSE) or ADAS-Cog scales. PBT2 had a favourable safety profile.

AUTHORS' CONCLUSIONS

There is an absence of evidence as to whether clioquinol (PBT1) has any positive clinical benefit for patients with AD, or whether the drug is safe. We have some concerns about the quality of the study methodology; there was an imbalance in treatment and control groups after randomisation (participants in the active treatment group had a higher mean pre-morbid IQ) and the secondary analyses of results stratified by baseline dementia severity. The planned phase III trial of PBT1 has been abandoned and this compound has been withdrawn from development. The second trial of PBT2 was more rigorously conducted and showed that after 12 weeks this compound appeared to be safe and well tolerated in people with mild Alzheimer's dementia. Larger trials are now required to demonstrate cognitive efficacy.

Cognitive dysfunction and greater visit-to-visit systolic blood pressure variability

OBJECTIVES

To determine whether variability in blood pressure (BP) is negatively associated with performance on cognitive testing.

DESIGN

Multinational, longitudinal, observational cohort study.

SETTING

The Alzheimer's Disease Neuroimaging Initiative study.

PARTICIPANTS

Individuals with a screening diagnosis of mild cognitive impairment or normal cognition (N=626).

MEASUREMENTS

Mean, variance, and maximum BP were calculated based on measures collected from screening to 36 months. Analysis of covariance models were used to determine the association between BP measures and cognitive scores at 36 months after adjusting for covariates.

RESULTS

Greater variability in systolic (P<.05) but not diastolic (P>.18) BP was associated with worse global (Modified Alzheimer's Disease Assessment Scale Cognitive Component and Clinical Dementia Rating sum of boxes) and executive (Trail-Making Test Part B, Animal Fluency, and Vegetable Fluency) function and episodic memory (Rey Auditory Verbal Learning Test Total Score).

CONCLUSION

There is a clinically significant association between greater systolic BP variability and greater cognitive dysfunction. These results should be verified in other well-characterized cohorts, and the neuroanatomical pathophysiology underlying the observed greater cognitive impairment should be further explored.

Registration of Alzheimer's disease in Taiwan: patient and informant

BACKGROUND

To obtain updated data of patients with Alzheimer's disease (AD) and their informants in Taiwan with the aim of fostering and supporting collaborative research.

METHODS

In total, 691 patients with the diagnosis of AD were recruited at 6 sites in Taiwan. The Uniform Data Set (UDS; form A) was administrated.

RESULTS

The mean age of the patients with AD was 79.3 ± 7.7 years and the mean age of informants was 57.5 ± 13.7 years. In all, 69% of the informants lived with patients and 77% of patients lived with spouse, partner, or children; 11% had 1 sibling with dementia, 1.8% had 2 siblings with dementia, and 0.5% had 3 or more siblings with dementia.

CONCLUSION

We have reported the updated status of AD in Taiwan through a UDS that will foster future collaboration among countries using UDS. The updated information of patients with AD and their informants will direct the future care of AD in Taiwan.

Influence of sex differences on microRNA gene regulation in disease

Sexual dimorphism is observed in most human diseases. The difference in the physiology and genetics between sexes can contribute tremendously to the disease prevalence, severity, and outcome. Both hormonal and genetic differences between males and females can lead to differences in gene expression patterns that can influence disease risk and course. MicroRNAs have emerged as potential regulatory molecules in all organisms. They can have a broad effect on every aspect of physiology, including embryogenesis, metabolism, and growth and development. Numerous microRNAs have been identified and elucidated to play a key role in cardiovascular diseases, as well as in neurological and autoimmune disorders. This is especially important as microRNA-based tools can be exploited as beneficial therapies for disease treatment and prevention. Sex steroid hormones as well as X-linked genes can have a considerable influence on the regulation of microRNAs. However, there are very few studies highlighting the role of microRNAs in sex biased diseases. This review attempts to summarize differentially regulated microRNAs in males versus females in different diseases and calls for more attention in this underexplored area that should set the basis for more effective therapeutic strategies for sexually dimorphic diseases.

Self-reported burden among caregivers of patients with multiple sclerosis

Multiple sclerosis (MS) and Alzheimer's disease (AD) are chronic and progressive diseases that may impose a significant burden on caregivers and patients' immediate families. Extensive research shows MS and AD caregiver burden on physical and mental health, but no direct comparisons between MS and AD caregivers have been reported in the literature. The objective of this study was to examine the extent of MS caregiver burden compared with that of noncaregivers and AD caregivers. Data were obtained from the 2009 National Health and Wellness Survey administered online to a US representative adult sample (N = 75,000). Respondents reported health status, quality of life, work productivity, health-care utilization, and caregiver status. Multivariable regressions, adjusting for key characteristics (eg, age, gender, marital status, depression), were conducted to explore differences between MS caregivers (n = 215) and noncaregivers (n = 69,224) and between MS caregivers and AD caregivers (n = 1341). The results indicated that MS caregivers had significantly greater activity impairment (P = .01), poorer mental (P = .015) and physical (P = .002) health status, lower health utility scores (P = .002), and more traditional health-care provider visits (P < .001), emergency room (ER) visits (P < .001), and hospitalizations (P = .001) than noncaregivers, adjusting for covariates. After adjustments, MS caregivers had greater activity impairment (P = .044), more ER visits (P = .017), and more hospitalizations (P = .008) than AD caregivers. Significant work productivity differences were not observed across groups, possibly owing to fewer employed respondents. Thus, in this study, MS caregivers had significantly more burden than noncaregivers, and for some measures, even AD caregivers. The results reveal the hidden toll on those providing care for MS patients and highlight the need for health-care providers to recognize their burden so that appropriate measures can be implemented.