Prevalence of dementia in East Asia: a synthetic review of time trends

A cross-sectional study of the major risk factor at different levels of cognitive performance within Chinese-origin middle-aged and elderly individuals

OBJECTIVE

Senior citizens suffering from cognitive impairment (CI) are on the East Asia rise. Multiple variables could lead to inter-/intra-individual cognition effectiveness variations, though previous research efforts did not consider weighting issues.

METHODS

This study scrutinized 5639 participants meeting required inclusion criteria by the CHARLS. Cognitive capacity was evaluated through Mini-Mental State Examination (MMSE). Considering that MMSE scorings were not following normal distribution, a non-parametric test and multiple linear regression were performed to screen candidate variables linked to cognitive capacity. Such applicability of candidate factors in the cumulative effect and the weighting of the impact on cognitive performance were evaluated by random forest (RF) algorithm.

RESULTS

Age, gender, education, marital status, residence, the type of residence, exercise, socialization level and drinking were correlated to MMSE scorings (p < 0.05). Among them, age, education, gender and sociality were correlated to individual MMSE items (p < 0.05). Regardless of MMSE scores and several MMSE items, age is always a prime factor. However, in the attention and computation item, education is better than age and ranks first.

CONCLUSIONS

This preliminary study prompted age, education, gender, and sociality with varying weightings to be linked to cognitive capacity within a Chinese cohort by differing cognitive aspects. At different levels of cognitive performance, the main risk factors are basically similar, but there are still some differences.

New evidence of trends in cognitive function among middle-aged and older adults in China, 2011-2018: an age-period-cohort analysis

BACKGROUND

Increasing evidence from high-income countries suggests the risk of cognitive impairment has been declining recently. However, related studies in China have rarely been done, and the results are inconsistent. We analyze the trends in cognitive function among middle-aged and older adults in China between 2011 and 2018.

METHODS

We used data from four waves of the China Health and Retirement Longitudinal Study (CHARLS), including 48918 individuals aged 45 years and older. Cognitive function was assessed using the CHARLS cognitive measures containing episodic memory, orientation, attention, and visuospatial abilities. The hierarchical age-period-cohort (APC) model was used to quantify the separate age, period, and cohort effects on trends in cognitive function.

RESULTS

The study sample's ages ranged from 45 to 105 years (Mean = 59.2, SD = 9.4). Cognitive function declined with age net of period and cohort effects, an apparent acceleration in the rate of cognitive decline after age 65 was found adjusting for individual characteristics. Although period effects on trends in cognitive function remained stable during the study period, hierarchical APC models demonstrated significant cohort variations. Independent of age and period effects, there was a fluctuating trend across cohorts before 1960 and an overall decline across successive cohorts.

CONCLUSIONS

Our study indicates that the age effect remains the most crucial factor regarding cognitive decline. Moreover, results demonstrate that cohorts living in social upheaval leading to educational deprivation and/or nutritional deficiency in early life may face a higher risk for cognitive deterioration later in life. Such findings indicate that dementia prevention from a life course perspective and cohort-specific strategies are critical to alleviating the future public-health burdens related to cognitive aging. Ongoing attention should be paid to the role of cross-cohort differences in education on cohort trends in cognition in countries like China that are aging rapidly and have a late start in educational expansion compared to other countries. Other factors, such as environmental stimulation, need to be noticed in younger cohorts.

White matter hyperintensities in cholinergic pathways are associated with dementia severity in e4 carriers but not in non-carriers

Background and objectives

Among individuals with Alzheimer's disease (AD), APOE e4 carriers with increased white matter hyperintensities (WMHs) may selectively be at increased risk of cognitive impairment. Given that the cholinergic system plays a crucial role in cognitive impairment, this study aimed to identify how APOE status modulates the associations between dementia severity and white matter hyperintensities in cholinergic pathways.

Methods

From 2018 to 2022, we recruited participants (APOE e4 carriers, n = 49; non-carriers, n = 117) from the memory clinic of Cardinal Tien Hospital, Taipei, Taiwan. Participants underwent brain MRI, neuropsychological testing, and APOE genotyping. In this study, we applied the visual rating scale of the Cholinergic Pathways Hyperintensities Scale (CHIPS) to evaluate WMHs in cholinergic pathways compared with the Fazekas scale. Multiple regression was used to assess the influence of CHIPS score and APOE carrier status on dementia severity based on Clinical Dementia Rating-Sum of Boxes (CDR-SB).

Results

After adjusting for age, education and sex, higher CHIPS scores tended to be associated with higher CDR-SB in APOE e4 carriers but not in the non-carrier group.

Conclusions

Carriers and non-carriers present distinct associations between dementia severity and WMHs in cholinergic pathways. In APOE e4 carriers, increased white matter in cholinergic pathways are associated with greater dementia severity. In non-carriers, WMHs exhibit less predictive roles for clinical dementia severity. WMHs on the cholinergic pathway may have a different impact on APOE e4 carriers vs. non-carriers.

Combining Neuropsychological Assessment with Neuroimaging to Distinguish Early-Stage Alzheimer's Disease from Frontotemporal Lobar Degeneration in Non-Western Tonal Native Language-Speaking Individuals Living in Taiwan: A Case Series

Neuropsychological tests (NPTs), which are routinely used in clinical practice for assessment of dementia, are also considered to be essential for differential diagnosis of Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD), especially the behavioral variants of frontotemporal dementia (bvFTD) and primary progressive aphasia (PPA) at their initial clinical presentations. However, the heterogeneous features of these diseases, which have many overlapping signs, make differentiation between AD and FTLD highly challenging. Moreover, NPTs were primarily developed in Western countries and for native speakers of non-tonal languages. Hence, there is an ongoing dispute over the validity and reliability of these tests in culturally different and typologically diverse language populations. The purpose of this case series was to examine which of the NPTs adjusted for Taiwanese society may be used to distinguish these two diseases. Since AD and FTLD have different effects on individuals' brain, we combined NPTs with neuroimaging. We found that participants diagnosed with FTLD had lower scores in NPTs assessing language or social cognition than AD participants. PPA participants also had lower measures in the Free and Cued Selective Reminding Test than those diagnosed with bvFTD, while bvFTD participants showed poorer performances in the behavioral measures than PPA participants. In addition, the initial diagnosis was supported by the standard one-year clinical follow-up.

Mortality Risks and Causes of Death by Dementia Types in a Japanese Cohort with Dementia: NCGG-Stories

BACKGROUND

Prognosis-related information regarding dementia needs to be updated, as changes in medical and long-term care environments for patients with dementia in recent decades may be improving the prognosis of the disease.

OBJECTIVE

We aimed to investigate the mortality, cause of death, and prognostic factors by types of dementia in a Japanese clinic-based cohort.

METHODS

The National Center for Geriatrics and Gerontology-Life Stories of People with Dementia consists of clinical records and prognostic data of patients who visited the Memory Clinic in Japan. Patients who attended the clinic between July 2010 and September 2018, or their close relatives, were asked about death information via a postal survey. A cohort of 3,229 patients (mean age, 76.9; female, 1,953) was classified into six groups: normal cognition (NC), mild cognitive impairment (MCI), Alzheimer's disease (AD), vascular dementia, dementia with Lewy bodies (DLB), and frontotemporal lobar degeneration. A Cox proportional hazards model was employed to compare the mortality of each type of dementia, MCI, and NC.

RESULTS

Patients with all types of dementia and MCI had higher mortality rates than those with NC (hazard risks: 2.61-5.20). The most common cause of death was pneumonia, followed by cancer. In the MCI, AD, and DLB groups, older age, male sex, and low cognitive function were common prognostic factors but not presence of apolipoprotein E ɛ4 allele.

CONCLUSION

Our findings suggest important differences in the mortality risk and cause of death among patients with dementia, which will be useful in advanced care planning and policymaking.

Different item characteristics of a mild cognitive impairment screening tool in the community-based Yilan Study: application of the item response theory

BACKGROUND

This study aimed to use item response theory (IRT) to explore the item-by-item characteristics of a mild cognitive impairment (MCI) screening tool using community-based data.

METHODS

The Yilan Study is a community-based study that has been conducted since 2012. Until March 2020, 2230 older adults were interviewed according to the household registration data. IRT was applied to determine the item-by-item distinctive characteristics of the Eight-item Interview to Differentiate Aging and Dementia (AD8).

RESULTS

The MCI characteristics in the AD8 items have varying degrees of item response threshold. In all circumstances, item AD8-8, which is related to self-rated memory ability, had a low item response threshold. AD8-5 and AD8-7, which are related to the comparisons of time-oriented functional status, had slightly lower thresholds, especially for those aged 65-79 years or without activity limitations. Conversely, AD8-1, AD8-2, AD8-3, AD8-4, and AD8-6 had similar item response thresholds and discriminative power; these items have more detailed functional descriptions or examples for illustration.

CONCLUSIONS

Concise and understandable elements are often expected in community-based screening tools. For community-based health screening and population empowerment in the early detection of MCI, assessment tool items with detailed functional descriptions and examples for illustration have similar validities in most of the population. Items related to self-rated memory ability might be less valid. More examples may be needed for items constructed for comparing time-oriented functional status, especially in extremely old adults and individuals with activity limitations.

Thyroid Disorders and Dementia Risk: A Nationwide Population-Based Case-Control Study

BACKGROUND AND OBJECTIVES

Dementia has been gaining attention in aging societies and is estimated to affect 50 million adults globally in 2020, and 12% of the US population may develop a thyroid disorder in their lifetime. There have been limited studies investigating the correlation between thyroid disorder and dementia in the Asian population.

METHODS

Our large nationwide population-based case-control study utilized the Taiwanese National Health Insurance Research Database. 7,843 adults with newly diagnosed dementia without a previous history of dementia or neurodegenerative disease between 2006 and 2013 were identified and included in our study. 7,843 adults without dementia diagnosis prior to the index date were age and gender matched as controls. Diagnosis of hyperthyroidism or hypothyroidism prior to the diagnosis of dementia or the same index date was identified. Results were obtained from logistic regression models and adjusted for sex, age, history of hypertension, diabetes, coronary artery disease, depression, hyperlipidemia, alcohol dependence syndrome, tinnitus, hearing loss, and radioactive iodine treatment.

RESULTS

A total of 15,686 patients were included in the study. Both case and control groups were slightly predominantly female (4,066 [51.8%]). The mean (SD) age for those with dementia was 74.9 (11.3) years, and for those without dementia was 74.5 (11.3) years. Among patients aged 65 years or older, a history of hypothyroidism was associated with an increased risk of being diagnosed with dementia (aOR, 1.81; 95% Cl 1.14-2.87; p=0.011), which was an association not present in patients older than 50 years but younger than 65 years. We found that this association was most significant among patients aged 65 years or older with a history of hypothyroidism who received hypothyroidism medication (aOR, 3.17; 95% Cl 1.04-9.69; p=0.043).

DISCUSSION

Our large-scale case-control study found that among people ≥ 65 years old, those with a history of hypothyroidism were associated with an 81% increased risk of having dementia and among those, there was an over 3-fold increased dementia risk with thyroid conditions that required thyroid hormone replacement treatment. Future well-controlled prospective longitudinal studies should be conducted to elucidate these potential mechanisms and relationships.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that among patients aged 65 years or older, a history of hypothyroidism was associated with an increased risk of being diagnosed with dementia.

The effects of caregiver characteristics on behavioral and psychological symptoms of dementia of patients with dementia

OBJECTIVE

To determine the association between caregiver characteristics and behavioral and psychological symptoms of dementia (BPSD) in patients with dementia (PWD) in a Taiwanese community-dwelling population.

METHODS

This cross-sectional study was conducted using the data of 190 patients with Alzheimer's disease/dementia and 190 informal matched caregivers in Taiwan. BPSD were examined using the Neuropsychiatric Inventory-Questionnaire (NPI-Q). Correlation and regression analyses were used to explore associations between caregiver characteristics and the presence, severity, and distress of NPI-Q items.

RESULTS

Only spouse primary caregiver was positively associated with presence of delusions in PWD. Caregiver education was positively correlated to severity of hallucinations, agitation/aggression, and apathy/indifference in PWD, while child primary caregiver was positively related to severity of disinhibition in PWD but negatively related to severity of anxiety in PWD. Spouse primary caregiver was positively related to severity of anxiety and appetite/eating in PWD while sole primary caregiver was positively related to severity of anxiety and nighttime behaviors in PWD. Caregiver education was positively correlated to distress of agitation/aggression in caregivers while child primary caregiver was positively related to distress of disinhibition in caregivers. Spouse primary caregiver was positively related to distress of anxiety and appetite/eating in caregivers while spouse caregiver was positively related to distress of nighttime behaviors in caregivers.

CONCLUSIONS

Caregiver education, child and spouse primary caregiver were relevant to severity of PWD and distress of caregivers of BPSD. It is suggested that healthcare professionals provide caregivers with proper individualized interventions based on these results to enhance caring quality.Key pointsCaregiver education was positively correlated to severity of hallucinations, agitation/aggression, and apathy/indifference, and distress of agitation/aggression.Child primary caregiver was positively related to severity and distress of disinhibition but negatively related to severity of anxiety.Spouse primary caregiver was positively related to severity and distress of anxiety and appetite/eating, and distress of nighttime behaviors.

Factors Associated with Lower Cognitive Performance Scores Among Older Japanese Men in Hawaii and Japan

BACKGROUND

Few studies have compared factors related to cognitive function among people with similar genetic backgrounds but different lifestyles.

OBJECTIVE

We aimed to identify factors related to lower cognitive scores among older Japanese men in two genetically similar cohorts exposed to different lifestyle factors.

METHODS

This cross-sectional study of community-dwelling Japanese men aged 71-81 years included 2,628 men enrolled in the Kuakini Honolulu-Asia Aging Study based in Hawaii and 349 men in the Shiga Epidemiological Study of Subclinical Atherosclerosis based in Japan. We compared participant performance through Cognitive Abilities Screening Instrument (CASI) assessment in Hawaii (1991-1993) and Japan (2009-2014). Factors related to low cognitive scores (history of cardiovascular disease, cardiometabolic factors, and lifestyle factors) were identified with questionnaires and measurements. Multivariable logistic regression analysis was used to calculate the adjusted odds ratios (ORs) of a low (< 82) CASI score based on different factors.

RESULTS

CASI scores were lower in Hawaii than in Japan [21.2%(n = 556) versus 12.3%(n = 43), p < 0.001], though this was not significant when adjusted for age and educational attainment (Hawaii 20.3%versus Japan 17.9%, p = 0.328). History of stroke (OR = 1.65, 95%confidence interval = 1.19-2.29) was positively associated with low cognitive scores in Hawaii. Body mass index ≥25 kg/m2 tended to be associated with low cognitive scores in Japan; there was a significant interaction between the cohorts.

CONCLUSION

Cognitive scores differences between cohorts were mostly explained by differences in educational attainment. Conversely, cardiovascular diseases and cardiometabolic factors differentially impacted cognitive scores among genetically similar older men exposed to different lifestyle factors.

Economic Status and Mortality in Patients with Alzheimer's Disease in Japan: The Longevity Improvement and Fair Evidence Study

OBJECTIVES

As more countries are implementing measures to address Alzheimer's disease (AD), it is essential to update the available knowledge on the relationship between economic status and mortality in patients with AD. This study examined the influence of economic status on mortality in Japanese individuals with AD using a medical claims dataset.

DESIGN

This was a retrospective cohort study.

SETTING AND PARTICIPANTS

Medical claims data from April 2014 to March 2019 were obtained from 13 local cities participating in the Longevity Improvement and Fair Evidence study. The inclusion criteria were patients aged 65 years and older who were newly diagnosed with AD during the study period.

METHODS

The outcome was death during the follow-up period. We assessed economic status by household income (middle to high income and low income); data were obtained from the use of the Medical Expenditure Ceiling Application and Standard Copayment Reduction Card (fee reduction card) when receiving an AD diagnosis, as an indicator of low-income status. We performed multivariate Cox proportional hazards analyses to examine the relationship between economic status and mortality; the model was adjusted for age, sex, the Charlson comorbidity index, and antidementia drug use.

RESULTS

We identified 39,081 newly diagnosed patients with AD from the Longevity Improvement and Fair Evidence study database (mean age, 83.6 years; female, 67.1%). Of these, 3189 individuals were identified as having a low-income status. After adjusting for possible confounders, low-income status was associated with mortality (hazard ratio, 1.95; 95% confidence interval, 1.84-2.07).

CONCLUSIONS AND IMPLICATIONS

Low-income status was associated with substantially poorer prognoses in new AD cases, indicating a need for a thorough examination of medical and nursing care services utilized by low-income individuals with AD and to explore improvement strategies.

A 9-Year Comparison of Dementia Prevalence in Korea: Results of NaSDEK 2008 and 2017

BACKGROUND

In many high-income Western countries, the prevalence of dementia had been reduced over the past decades.

OBJECTIVE

We investigated whether the prevalence of all-cause dementia, Alzheimer's disease, vascular dementia, and mild cognitive impairment (MCI) had changed in Korea from 2008 to 2017.

METHODS

Nationwide Survey on Dementia Epidemiology of Korea (NaSDEK) in 2008 and 2017 was conducted on representative elderly populations that were randomly sampled across South Korea. Both surveys employed a two-stage design (screening and diagnostic phases) and diagnosed dementia and MCI according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders and the consensus criteria from the International Working Group, respectively. The numbers of participants aged 65 years or older in the screening and diagnostic phases were 6,141 and 1,673 in the NaSDEK 2008 and 2,972 and 474 in the NaSDEK 2017, respectively.

RESULTS

The age- and sex-standardized prevalence of all-cause dementia and Alzheimer's disease showed nonsignificant decrease (12.3% to 9.8%, odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.54-1.48 for all-cause dementia; 7.6% to 6.8%, OR [95% CI] = 0.91 [0.58-1.42] for Alzheimer's disease). Vascular dementia decreased in the young-old population aged less than 75 years (2.7% to 0.001%, OR [95% CI] = 0.04 [0.01-0.15]) and in women (1.9% to 0.5%, OR [95% CI] = 0.27 [0.10-0.72]) while MCI remained stable (25.3% to 26.2%, OR [95% CI] = 1.08 [0.67-1.73]).

CONCLUSION

We found that the prevalence of dementia in Korea showed a nonsignificant decrease between 2008 and 2017.

Depression and executive functioning bidirectionally impair one another across 9 years: Evidence from within-person latent change and cross-lagged models

BACKGROUND

Scar and vulnerability models assert that increased psychopathology may predict subsequent executive functioning (EF) deficits (and vice versa) over protracted timescales, yet most prior work on this topic has been cross-sectional. Thus, we tested the within- and between-person relations between EF, depression, and anxiety.

METHODS

Older adult participants (n = 856) were assessed across four waves, approximately 2 years apart. Performance-based EF and caregiver-rated symptom measures were administered. Bivariate latent change score and random-intercept cross-lagged panel models were conducted.

RESULTS

Within persons, random-intercept cross-lagged panel models revealed that prior greater depression forecasted lower subsequent EF, and vice versa (d = -0.292 vs. -0.292). Bivariate dual latent change score models showed that within-person rise in depression predicted EF decreases, and vice versa (d = -0.245 vs. -0.245). No within-person, cross-lagged, EF-anxiety relations emerged. Further, significant negative between-person EF-symptom relations were observed (d = -0.264 to -0.395).

CONCLUSION

Prospective, within-person findings offer some evidence for developmental scar and vulnerability models.

Prevalence estimates of dementia in older adults in rural Kilimanjaro 2009-2010 and 2018-2019: is there evidence of changing prevalence?

INTRODUCTION

Although limited, existing epidemiological data on dementia in sub-Saharan Africa indicate that prevalence may be increasing; contrasting with recent decreases observed in high-income countries. We have previously reported the age-adjusted prevalence of dementia in rural Tanzania in 2009-2010 as 6.4% (95% confidence interval [CI] 4.9-7.9) in individuals aged ≥70 years. We aimed to repeat a community-based dementia prevalence study in the same setting to assess whether prevalence has changed.

METHODS

This was a two-phase door-to-door community-based cross-sectional survey in Kilimanjaro, Tanzania. In Phase I, trained primary health workers screened all consenting individuals aged ≥60 years from 12 villages using previously validated, locally developed, tools (IDEA cognitive screen and IDEA-Instrumental Activities of Daily Living questionnaire). Screening was conducted using a mobile digital application (app) on a hand-held tablet. In Phase II, a stratified sample of those identified in Phase I were clinically assessed using the DSM-5 criteria and diagnoses subsequently confirmed by consensus panel.

RESULTS

Of 3011 people who consented, 424 screened positive for probable dementia and 227 for possible dementia. During clinical assessment in Phase II, 105 individuals met DSM-5 dementia criteria. The age-adjusted prevalence of dementia was 4.6% (95% CI 2.9-6.4) in those aged ≥60 years and 8.9% (95% CI 6.1-11.8) in those aged ≥70 years. Prevalence rates increased significantly with age.

CONCLUSIONS

The prevalence of dementia in this rural Tanzanian population appears to have increased since 2010, although not significantly. Dementia is likely to become a significant health burden in this population as demographic transition continues.

MRI Markers of Mixed Pathology and Cognitive Impairment in Multiethnic Asians

There is a need to elucidate the combined influence of neurodegeneration and cerebrovascular disease (CeVD) on cognitive impairment, especially in diverse populations. Here, we evaluated 840 multiethnic individuals (mean age = 70.18) across the disease spectrum from the Epidemiology of Dementia in Singapore study. First, we determined whether a validated quantitative MRI score of mixed pathology is associated with clinical diagnosis and whether the score differed between ethnicities (Chinese, Malays, and Indians). We then evaluated whether the score was associated with multidomain cognitive impairment and if additional measures of CeVD were further associated with cognitive impairment. We found that lower quantitative MRI scores were associated with severity of clinical diagnosis and Chinese individuals had the highest quantitative MRI scores, followed by Indians and Malays. Lower quantitative MRI scores were also associated with lower performance in attention, language, visuoconstruction, visuomotor, visual, and verbal memory domains. Lastly, the presence of intracranial stenosis and cortical cerebral microinfarcts, but not cerebral microbleeds, were associated with memory performance beyond quantitative MRI scores. Taken together, our results demonstrate the utility of using multiple MRI markers of neurodegeneration and CeVD for identifying multiethnic Asians with the greatest cognitive impairment due to mixed pathology.

Trends in the prevalence of cognitive impairment in Chinese older adults: based on the Chinese Longitudinal Healthy Longevity Survey cohorts from 1998 to 2014

In the context of a rapidly ageing Chinese population, this study aims to examine trends in the prevalence of cognitive impairment among people ≥65 y of age in China. Our sample is 72 821 adults aged 65–105 y from the seven waves of the Chinese Longitudinal Healthy Longevity Survey, a national mixed longitudinal cohort. The Chinese version of the Mini-Mental State Examination was used to measure CI. Risk factor-adjusted prevalence trend was examined using multilevel regression models. Age-standardized prevalence of cognitive impairment increased from 11.00% in 1998 to 11.84% in 2008 and decreased to 8.88% in 2014. Older age, female gender, less education, rural residence, not married, lack of physical and cognitive activities, suffering from stroke, vision and hearing impairment, and activities of daily living disability were negatively associated with cognitive impairment. Our study suggests a decreasing trend of cognitive impairment prevalence in China. However, whether decreasing prevalence will contribute to a reduced burden of cognitive impairment given the ageing of the population is unknown.

Prevalence and incidence of dementia in an older Chinese population over two decades: The role of education

INTRODUCTION

Secular trends of dementia prevalence and incidence have rarely been studied in the Chinese population.

METHODS

We examined the changes in dementia prevalence and incidence by comparing data from Shanghai Epidemiological Survey of Dementia and Alzheimer's disease (SESD) and Shanghai Aging Study (SAS) conducted two decades apart.

FINDINGS

The dementia prevalence and incidence in total participants in SAS were higher than that in SESD (prevalence: 6.44% vs 2.30%, P < .001; annual incidence: 2.58% vs 1.33%, P < .001). In participants with ≤6 years of education, the dementia prevalence in SAS was higher than that in SESD (6.39% vs 3.07%, P < .001); the annual dementia incidence in SAS was double that in SESD (3.63% vs 1.80%, P = .019).

DISCUSSION

We observed an increasing trend of dementia prevalence and incidence in the Chinese elderly, especially those with low education. The dramatic rise in numbers of people with dementia may happen most likely in low-educated populations.

Cognitive impairment and its risk factors among Myanmar elderly using the Revised Hasegawa's Dementia Scale: A cross-sectional study in Nay Pyi Taw, Myanmar

Background

Globally, elderly population with impaired cognitive function, such as dementia, has been accelerating, and Myanmar is no exception. However, cognitive function among elderly in Myanmar has rarely been assessed. This study aimed to identify the rate of cognitive impairment and its risk factors among the elderly in Myanmar.

Methods

This cross-sectional study was conducted at rural health centers in Nay Pyi Taw Union Territory, Myanmar, from December 2018 to January 2019. In total, 757 elderly individuals aged 60 years or over (males: 246 [32.5%], females: 511 [67.5%]) were interviewed using a face-to-face method with a pre-tested questionnaire. Descriptive statistics and multivariable logistic regression analyses were performed.

Results

The rate of impaired cognitive function among participants was 29.9% (males: 23.6%; females: 32.9%). The following participants were more likely to present cognitive impairment: those aged 70–79 years (adjusted odds ratio [AOR] = 1.8; 95% confidence interval [CI]: 1.19–2.70) and 80 years or older (AOR = 3.9; 95% CI: 2.25–6.76); those who were illiterate (AOR = 9.1; 95% CI: 3.82–21.51); and those dependent on family members (AOR = 1.6; 95% CI: 1.04–2.44). The elderly livening with their families and those who reported having good health (AOR = 0.7; 95% CI: 0.44–0.99) were less likely to have cognitive impairment.

Conclusion

Using the HDS-R Myanmar version, this study reported that there out of five elderly participants had cognitive impairment, and its risk factors, altering policy makers that Myanmar needs to prepare for adequate healthcare services and social support for elderly with cognitive impairment. Future research should be performed not only to detect general cognitive impairment but also to differentiate specific cognitive domains impairments among Myanmar elderly. Longitudinal studies are needed to observe the causal and protective factors associated with cognitive impairments in Myanmar.

Survival Analysis of Patients with Alzheimer's Disease: A Study Based on Data from the Korean National Health Insurance Services' Senior Cohort Database

BACKGROUND

Korea's rapidly aging population has experienced a sharp rise in the prevalence of dementia. Patients with Alzheimer's disease (AD), which is estimated to be about three-quarters of all patients with dementia, tend to have higher mortality rates compared with patients without Alzheimer's disease. In this study, a survival analysis of patients with AD was conducted in order to provide knowledge to those who provide medical care to these patients.

METHODS

Data on individuals over 65 years old in 2004 were extracted from the Korean National Health Insurance Services' Senior Cohort database (2002-2013). The subjects were 209,254 patients, including 2,695 who were first diagnosed with AD (the AD group) and 206,559 that had not been diagnosed with the disease (non-AD group). To investigate the independent effect of AD on survival, the Cox proportional-hazards model, hazard ratios (confidence interval of 95%), and the Kaplan-Meier method were used.

RESULTS

Mean survival time in the AD group was 5.3±3.3 years, which was about 2.5 years shorter than that in the non-AD group (7.8±2.4 years). The mortality rate in the AD group (66.3%) was higher than that in the non-AD group (26.3%). The adjusted hazard ratio in the AD group was 2.5 and, therefore, it was found that the AD group had a 2.5-fold higher risk of death than the non-AD group.

CONCLUSION

Overall, AD has a large, independent impact on survival. Survival time was shorter, and the mortality rate and risk were generally higher in the AD group, compared with the non-AD group.

Risk of Incident Dementia According to Metabolic Health and Obesity Status in Late Life: A Population-Based Cohort Study

CONTEXT

The risk for dementia among subjects who are obese with normal metabolic profiles, or called metabolically healthy obese (MHO), remains uninvestigated.

OBJECTIVE

To determine the association between late-life metabolic health and obesity status and risk of incident dementia.

DESIGN

Retrospective cohort study.

SETTING

The National Health Insurance System, Republic of Korea.

PATIENTS

A total of 12,296,863 adults >50 years old who underwent health examinations from 2009 to 2012 without baseline history of dementia.

MAIN OUTCOME MEASURE

Incident overall dementia, Alzheimer's disease (AD), and vascular dementia (VaD).

RESULTS

Among subjects ≥60 years old, 363,932 (6.4%) developed dementia during a median follow-up of 65 months (interquartile range 51 to 74 months). The MHO group showed the lowest incidence of overall dementia [hazard ratio (HR) 0.85; 95% CI, 0.84 to 0.86] and AD (HR 0.87; 95% CI, 0.86 to 0.88), but not VaD, compared with the metabolically healthy nonobese group. All components of metabolic syndrome except obesity significantly elevated the risk of dementia, and these associations were more pronounced in VaD. In particular, being underweight dramatically increased the risk of dementia.

CONCLUSIONS

The MHO phenotype in late life demonstrated lower risk of overall dementia and AD but not VaD. Additional studies in other populations are warranted to elucidate current results and may predict individuals most at risk for developing dementia.

Cognitive function measured with the Revised Hasegawa's Dementia Scale among elderly individuals in Lao PDR

In Lao PDR, measurement of cognitive function has rarely been conducted among elderly individuals. This study aimed to investigate the cognitive function among elderly individuals who lived at their homes with family in Lao PDR. Participants were elderly individuals aged 60 years or over registered with the local government in urban (Vientiane capital; VC) and rural areas (Khammouane province; KP). Those with serious mental/physical diseases, those who could not walk by themselves, or those who could not speak the Lao language were excluded. The information was collected through interviews with the participants and their family members. A newly developed Lao version of the Revised Hasegawa’s Dementia Scale (HDS-R) was applied to measure cognitive function. The participants were 414 elderly individuals (224 males and 190 females) aged 60 to 98 years. The average HDS-R score was 23.0 among 115 men in VC, 22.7 among 92 women in VC, 20.3 among 109 men in KP, and 17.5 among 98 women in KP. The main caregiver was a daughter (40.6%) followed by a spouse (31.4%). Among 414 elderly individuals, 42 (10.0%) stated the necessity of support. Those with HDS-R < 20 accounted for 38.8% in men and 48.9% in women. The adjusted odds ratio of HDS-R < 20 was significant for those in rural areas (3.83) relative to those in urban areas. Among superficially healthy elderly individuals residing with their families, those with reduced cognitive function were more common among women and in rural areas.

Electroacupuncture Mitigates Hippocampal Cognitive Impairments by Reducing BACE1 Deposition and Activating PKA in APP/PS1 Double Transgenic Mice

Increased amyloid-β (Aβ) plaque deposition is thought to be the main cause of Alzheimer's disease (AD). β-Site amyloid precursor protein cleaving enzyme 1 (BACE1) is the key protein involved in Aβ peptide generation. Excessive expression of BACE1 might cause overproduction of neurotoxins in the central nervous system. Previous studies indicated that BACE1 initially cleaves the amyloid precursor protein (APP) and may subsequently interfere with physiological functions of proteins such as PKA, which is recognized to be closely associated with long-term potentiation (LTP) level and can effectively ameliorate cognitive impairments. Therefore, revealing the underlying mechanism of BACE1 in the pathogenesis of AD might have a significant impact on the future development of therapeutic agents targeting dementia. This study examined the effects of electroacupuncture (EA) stimulation on BACE1, APP, and p-PKA protein levels in hippocampal tissue samples. Memory and learning abilities were assessed using the Morris water maze test after EA intervention. Immunofluorescence, immunohistochemistry, and western blot were employed to assess the distribution patterns and expression levels of BACE1, APP, and p-PKA, respectively. The results showed the downregulation of BACE1 and APP and the activation of PKA by EA. In summary, EA treatment might reduce BACE1 deposition in APP/PS1 transgenic mice and regulate PKA and its associated substrates, such as LTP to change memory and learning abilities.

The temporal trend and distribution characteristics in mortality of Alzheimer's disease and other forms of dementia in China: Based on the National Mortality Surveillance System (NMS) from 2009 to 2015

Background

China is experiencing rapid age, which will lead to increasing burden of age-related diseases, such as Alzheimer disease and other forms of dementia.

Objectives

The aim of this study was to 1) Explore the temporal trend of mortality of Alzheimer disease (AD) and other forms of dementia in China and 2) Analyze its geographic variations and urban-rural differences and calculate the years of life lost (YLLs) from AD and other forms of dementia.

Data and methods

Data were extracted from the National Mortality Surveillance System (NMS). Age-standardized mortalities were calculated with the Western Grade 26 Standard Life List, and the YLLs were calculated using the DALY template provided by the WHO / World Bank global burden of disease (GBD) Working Group. The trends in crude and age-standardized mortality of AD and other forms of dementia were examined using Cochran-Armitage trend test.

Results

In China, the crude mortality from AD and other forms of dementia increased from 2009 to 2015, but the age-standardized mortality decreased. The YLLs of AD and other forms of dementia increased during the study period. The age-standardized mortality in the east was higher than those in the west and middle regions, and the age-standardized mortality in rural areas was higher than that in urban areas.

Conclusion

In China, the age-standardized mortality of AD and other forms of dementia decreased from 2009 to 2015. However, the disease burden from AD and other forms of dementia is becoming heavier due to increasing elderly population. Moreover, there were geographic variations and urban-rural differences in mortality of AD and other forms of dementia in China.

Multidisciplinary approaches for targeting the secretase protein family as a therapeutic route for Alzheimer's disease

The continual increase of the aging population worldwide renders Alzheimer's disease (AD) a global prime concern. Several attempts have been focused on understanding the intricate complexity of the disease's development along with the on- andgoing search for novel therapeutic strategies. Incapability of existing AD drugs to effectively modulate the pathogenesis or to delay the progression of the disease leads to a shift in the paradigm of AD drug discovery. Efforts aimed at identifying AD drugs have mostly focused on the development of disease-modifying agents in which effects are believed to be long lasting. Of particular note, the secretase enzymes, a group of proteases responsible for the metabolism of the β-amyloid precursor protein (βAPP) and β-amyloid (Aβ) peptides production, have been underlined for their promising therapeutic potential. This review article attempts to comprehensively cover aspects related to the identification and use of drugs targeting the secretase enzymes. Particularly, the roles of secretases in the pathogenesis of AD and their therapeutic modulation are provided herein. Moreover, an overview of the drug development process and the contribution of computational (in silico) approaches for facilitating successful drug discovery are also highlighted along with examples of relevant computational works. Promising chemical scaffolds, inhibitors, and modulators against each class of secretases are also summarized herein. Additionally, multitarget secretase modulators are also taken into consideration in light of the current growing interest in the polypharmacology of complex diseases. Finally, challenging issues and future outlook relevant to the discovery of drugs targeting secretases are also discussed.

Impact of time spent walking on incident dementia in elderly Japanese

OBJECTIVES

This study examined the hypothesis that time spent walking daily has a marked impact on incident dementia.

METHODS/DESIGN

First, we analyzed data from a Japanese cohort (n = 13 990 aged ≥65 y) to obtain hazard ratios. Time spent walking per day (<0.5, 0.5-1, or ≥1 h) was assessed using a self-reported questionnaire. Data on 5.7-year incident dementia were retrieved from the public long-term care insurance database. After estimating the multivariate-adjusted hazard ratios (HRs) of incident dementia using the Cox model, the population attributable fraction (PAF) was calculated using the prevalence in a representative Japanese survey, the "National Health and Nutrition Survey".

RESULTS

The time spent walking per day showed an inverse association with incident dementia: the multiple-adjusted HRs (95% confidence intervals) were 1.00 (reference) for less than 0.5 hour, 0.81 [0.71, 0.92] for 0.5 to 1 hour, and 0.72 [0.62, 0.84] for more than or equal to 1 hour. Our estimates indicate that 18.1% of dementia cases would be attributable to walking if all subjects walked more than or equal to 1 h/d and 14.0% if subjects increased their daily time spent walking to one level above the present one (<0.5 to 0.5-1 or 0.5-1 to ≥1 h).

CONCLUSIONS

Our results suggest that the daily time spent walking has a considerable preventive impact on incident dementia in Japan.

Diabetic ketoacidosis further increases risk of Alzheimer's disease in patients with type 2 diabetes

AIM

Diabetes mellitus (DM) is a known risk factor for dementia. It is unclear whether diabetic ketoacidosis (DKA) further increases the risk of dementia in patients with type 2 DM.

METHODS

This retrospective nationwide population-based cohort study was conducted using Taiwan's National Health Insurance database. We extracted claims data for 4451 patients with type 2 diabetes and DKA and 8902 diabetic controls matched for age, gender, diabetes complication severity index, frequency of clinic visits and baseline comorbidities between 2000 and 2002. Patients with type 1 diabetes or prior hypoglycemia before index date were excluded. All patients were tracked until new dementia diagnosis, death, or end of 2011.

RESULTS

Of the 4451 DKA patients, 211 (4.7%) and 305 (3.4%) of the 8902 diabetic controls were diagnosed as having dementia during the follow-up period. The incidence rate ratio (IRR) for dementia was 1.62 (95% CI 1.35-1.93; P < 0.0001) for patients with DKA versus diabetic patients without DKA. After adjusting for age, baseline comorbidities, geographic area, and income, patients with DKA were found to have 1.86 times the risk of developing dementia, compared to controls (95% CI 1.56-2.22, P < 0.0001). They were found to have a higher risk of Alzheimer's dementia (HR:1.86; 95% CI 1.52-2.28, P < 0.0001) but not non-Alzheimer's dementia.

CONCLUSION

Type 2 diabetes patients with DKA are at increased risk of Alzheimer's dementia but not non-Alzheimer dementia.

Effects of acupuncture on patients with Alzheimer's disease: Protocol for a systematic review and meta-analysis

BACKGROUND

Alzheimer's disease (AD) is the leading progressive neurodegenerative disease worldwide, accompanied with nonreversible cognitive impairments. Acupuncture, as the traditional Chinese technique, is widely applied in clinical trials for AD. The aim of this review is to evaluate the efficacy and safety of acupuncture in the aspect of antidementia.

METHODS

Randomized controlled trials (RCTs) related to acupuncture treatment targeting AD will be collected. We will search the following 4 databases of electronic English resources, including PubMed, Embase, MEDLINE, Web of Science, and 4 Chinese databases, namely CNKI, CBM, VIP, and Wanfang database. All the RCTs will be searched from their inception to November 2018. After screening the studies, a meta-analysis of RCTs will be carried out. Subsequently, the assessment of bias risk, data synthesis, subgroup analysis will be conducted using RevMan V.5.3.5 software if the setting condition is met.

RESULTS

This systematic view and meta-analysis will assess the efficacy and safety of acupuncture intervention on AD patients, which is fundamentally based on current published evidence, and provide a high-quality synthesis for clinical practitioners of treating AD with acupuncture, CONCLUSION:: The summary of our systematic view will determine whether acupuncture intervention could be an efficient and feasible approach to the treatment of AD patients.

Lao language version of the Revised Hasegawa's Dementia Scale

With the aging of society, the number of elderly with reduced cognitive function has been increasing worldwide. As a test to measure the cognitive function, the Revised Hasegawa’s Dementia Scale (HDS-R) has been used in Japan, Korea, and China. Since there was no HDS-R version for Laotians, the questionnaire and manual were developed through the cooperation of Lao and Japanese researchers. Back-translation was conducted to confirm the accuracy of the translation. The score on the 9-item HDS-R ranges 0 to 30 points, and reduced cognitive function is usually defined as a score of 20 points or lower. After receiving explanation regarding the use of the tool and practicing its implementation, 3 female doctors interviewed 30 superficially healthy volunteers aged 31 to 84 years (12 males and 18 females) who lived with his/her family in Vientiane Capital, Lao PDR. Their score distributed from 4 to 30 points, with an average of 24.7 (standard deviation 5.4) points. Six (20.0%) participants scored 20 points or lower. The discussion before and after the pilot interviews revealed that the following changes needed to be made in accordance to the culture of Lao people; 1) order of date in Question 2, 2) words to be memorized in Questions 4 and 7, 3) objects to be memorized using pictures, not actual objects, in Question 8. Additionally, we introduced new two rules; a clear time definition for no reply (10 seconds), and repetition of questions twice for those with ear problems. The revised version of the HDS-R was thought to be an appropriate standard questionnaire for use in studies on cognitive function among Laotians.

The Prevalence of Alzheimer's Disease in China: A Systematic Review and Meta-analysis

BACKGROUND

Several studies have investigated the prevalence of Alzheimer's disease (AD) among the general population in several parts of China. However, the results have been inconsistent. This meta-analysis was conducted to estimate the overall prevalence of AD between 2007 and 2017 in China.

METHODS

English and Chinese electronic databases were searched with a date range from Nov 2007 to Nov 2017 and the reference lists of the included studies were screened as well. Cross-sectional studies addressing the prevalence of AD among the general Chinese population were retrieved irrespective of the age, location or sex of the participants. Study quality was assessed using the recommended checklist of STROBE.

RESULTS

Overall, 184058 subjects and 7445 patients with AD were included from 17 studies in this meta-analysis. The overall prevalence of AD in China was calculated to be 0.04(95% CI:0.04-0.05). The prevalence was higher in older age groups, among females, and in the rural areas of the country, with an increasing trend in recent years.

CONCLUSION

AD is a common problem among those in the Chinese population older than 65 yr. Furthermore, an increasing trend of the disease over the past 10 years is indicative of a critical public health problem in China in the near future. Further evidence based on a national survey is needed to estimate the exact prevalence of the disease in the country.

Is dementia incidence declining in high-income countries? A systematic review and meta-analysis

Purpose

To perform a systematic review and quantitative synthesis of studies on recent trends in dementia incidence in high-income countries (HIC), considering study quality.

Methods

PubMed and Web of Science were searched for eligible studies, that is, population-based/community-based prospective cohort studies investigating dementia incidence with similar methods over time, published after 1990. Study selection, data extraction, and quality assessment were performed independently by two investigators. Random-effect meta-analysis and meta-regression were used to estimate incidence change (IC) and to explore associations with study attributes. PRISMA standards were followed.

Results

The systematic review included seven studies (42,485 individuals), and the meta-analysis included five studies of sufficient quality. Relating dementia incidence of later cohorts to earlier cohorts (reference) yielded a nonsignificant decrease across HIC (IC =0.82; 95% CI 0.51–1.33), with high heterogeneity (I²=94.9%, P<0.001) and without publication bias (Egger’s t=–1.77; P=0.18). Excluding the Japanese Hisayama study, the only study suggesting an increase, indicated borderline evidence for a decrease across Western HIC (IC =0.69; 95% CI 0.47–1.00; I²=88.1%, P<0.001; Egger’s t=–0.34, P=0.77), again with high heterogeneity. Meta-regression did not reveal an association of incidence rate with calendar year or study attributes; however, analyses were low powered.

Conclusion

There is evidence of favorable trends in dementia incidence in Western HIC (stabilizing/decreasing). Reverse trends may occur in HIC of other regions, as exemplified by Japan. However, study number was small and heterogeneity was high. Further cohort studies using consistent methods are needed to draw definite conclusions. Our work may inform such future studies.

Electroacupuncture Could Influence the Expression of IL-1β and NLRP3 Inflammasome in Hippocampus of Alzheimer's Disease Animal Model

Background

Effective therapies for Alzheimer's disease (AD) are still being explored. Electroacupuncture with traditional Chinese medicine theory may improve spatial learning and memory abilities and glucose metabolism rates in an animal model of AD. However, the mechanism of electroacupuncture in intervention of AD is still unclear. According to recent studies of AD mechanisms, the NLRP3 inflammasome regulated the expression of IL-1β in the brain which may mediate AD related processes. Therefore, in our study, we intend to explore the possible relation between electroacupuncture and the expression of NLRP 3 inflammasome in the hippocampus of an AD animal model.

Method

In this study, 7.5-month-old male senescence-accelerated mouse prone 8 (SAMP8) mice were used as an AD animal model, which were randomly divided into two groups: Alzheimer's disease model group (AD group) and electroacupuncture group (EA group). In the control paradigm, 7.5-month-old male SAMR1 mice were used as the normal control group (N group). DU20, DU26, and EX-HN3 were selected as the acupuncture points, and after a 15-day treatment of electroacupuncture, we used immunohistochemistry and Western blotting to examine the expression of IL-1β and NLRP3, ASC, and Caspase-1 in the hippocampus of the AD animal model.

Results

Compared with N group, IL-1β, NLRP3, ASC, and Caspase-1 positive cells in AD group were increased, and the relative expression of all above proteins significantly increased (P < 0.01). Compared with AD group, the expression of IL-1β, NLRP3, ASC, and Caspase-1 in EA group was significantly decreased (P < 0.01).

Conclusion

Electroacupuncture treatment could inhibit the inflammation reaction in the hippocampus of SAMP8 mice. What is more, the possible mechanism of electroacupuncture reduced the expression of IL-1β and NLRP3 inflammasome relative protein.

Comparisons between traditional medicines and pharmacotherapies for Alzheimer disease: A systematic review and meta-analysis of cognitive outcomes

OBJECTIVES

To evaluate the clinical evidence for traditional medicines (TMs) used in East Asia on measures of cognition in Alzheimer disease, determine the effect sizes at different time points for the TMs and pharmacotherapies, and assess the tolerability of the TMs.

METHODS

We searched 12 databases in English, Chinese, and Japanese for eligible randomised controlled trials that compared orally administered TMs with pharmacotherapy and reported cognitive outcomes. Meta-analyses were conducted for Alzheimer's Disease Assessment Scale-cognitive subscale and/or Mini-Mental State Examination (MMSE). Mean differences and 95% confidence intervals were calculated to evaluate treatment effects.

RESULTS

Thirty randomised controlled trials met inclusion criteria. Twenty-nine compared TMs with donepezil. Single studies provided comparisons with galantamine, rivastigmine, or memantine. There were no significant differences between the TM and donepezil groups at 12 or 24 weeks for Alzheimer's Disease Assessment Scale-cognitive subscale or MMSE. Improvements over baseline were significant for MMSE at 12 and 24 weeks within the TM and donepezil groups and remained significant at 1 year. Effect sizes were reduced in the 3 double-blind studies. At 24 weeks, donepezil 10 mg/d generally produced greater improvements in MMSE than 5 mg/d. Tolerability reporting was incomplete and inconsistent between studies.

CONCLUSIONS

The results suggested that the clinical benefits of the TMs were not less than donepezil at comparable time points, with both groups showing improvements. However, lack of blinding in most studies and other design and measurement issues are likely to have resulted in overestimation of effect sizes in both groups. Further well-designed studies are needed.

The time trends of cognitive impairment incidence among older Chinese people in the community: based on the CLHLS cohorts from 1998 to 2014

Objective

to examine a 16-year trend in cognitive impairment (CI) incidence and associated factors among older Chinese people.

Subjects

aged 60 and above whose cognitive function were normal at their first test.

Methods

a secondary analysis that identified subjects from the database of Chinese Longitudinal Healthy Longevity Survey (CLHLS). The database contained mixed longitudinal cohorts of older Chinese people surveyed in 1998, 2000, 2002, 2005, 2008-09, 2011-12 and 2014. The cognitive function of subjects was tested using the Chinese Mini-Mental State Examination (CMMSE) in each wave. The unique individual code identified a mixed cohort of 17,896 subjects who had multiple CMMSE measures over a 16-year period and available covariates for the analysis. CI was defined as the CMMSE score below 18 points. Crude and age-standardised incidence of CI by gender were calculated by year of survey. Risk factor adjusted time trends in the incidence were examined using multilevel regression models.

Results

age-standardised CI incidence decreased from 58.77‰ to 10.09‰ (P < 0.001) from 1998 to 2014, and this decrease remained after adjusting for covariates. About 15.8% in the observed decline was explained by higher education, and 7.9% was due to health practice (regular exercise, physical activity and cognitive activity), beyond age and gender effects.

Conclusion

the CI incidence among older Chinese people decreased from 1998 to 2014. Lower education level and less frequent health practices mentioned above were important risk factors in CI prevention.

Decreasing prevalence of dementia in 85-year olds examined 22 years apart: the influence of education and stroke

Individuals aged 80 years and older constitute the fastest growing segment of the population worldwide, leading to an expected increase in dementia cases. Education level and treatment of vascular risk factors has increased during the last decades. We examined whether this has influenced the prevalence of dementia according to DSM-III-R using population-based samples of 85-year-olds (N = 1065) examined with identical methods 1986–87 and 2008–10. The prevalence of dementia was 29.8% in 1986–87 and 21.7% in 2008–10 (OR 0.66; 95%-CI: 0.50–0.86). The decline was mainly observed for vascular dementia. The proportion with more than basic education (25.2% and 57.7%), and the prevalence of stroke (20% and 30%) increased, but the odds ratio for dementia with stroke decreased from 4.3 to 1.8 (interaction stroke*birth cohort; p = 0.008). In a logistic regression, education (OR 0.70; 95%-CI 0.51–0.96), stroke (OR 3.78; 95%-CI 2.28–6.29), interaction stroke*birth cohort (OR 0.50; 95%-CI 0.26–0.97), but not birth cohort (OR 0.98; 95%-CI 0.68–1.41), were related to prevalence of dementia. Thus, the decline in dementia prevalence was mainly explained by higher education and lower odds for dementia with stroke in later born birth cohorts. The findings may be related to an increased cognitive reserve and better treatment of stroke in later-born cohorts.

The changing prevalence and incidence of dementia over time - current evidence

Dementia is an increasing focus for policymakers, civil organizations and multidisciplinary researchers. The most recent descriptive epidemiological research into dementia is enabling investigation into how the prevalence and incidence are changing over time. To establish clear trends, such comparisons need to be founded on population-based studies that use similar diagnostic and research methods consistently over time. This narrative Review synthesizes the findings from 14 studies that investigated trends in dementia prevalence (nine studies) and incidence (five studies) from Sweden, Spain, the UK, the Netherlands, France, the USA, Japan and Nigeria. Besides the Japanese study, these studies indicate stable or declining prevalence and incidence of dementia, and some provide evidence of sex-specific changes. No single risk or protective factor has been identified that fully explains the observed trends, but major societal changes and improvements in living conditions, education and healthcare might have favourably influenced physical, mental and cognitive health throughout an individual's life course, and could be responsible for a reduced risk of dementia in later life. Analytical epidemiological approaches combined with translational neuroscientific research could provide a unique opportunity to explore the neuropathology that underlies changing occurrence of dementia in the general population.

Impact of living arrangements on clinical outcomes among older patients with dementia or cognitive impairment admitted to the geriatric evaluation and management unit in Taiwan

AIM

To evaluate the impact of living arrangements on mortality and functional decline among older patients with dementia or cognitive impairment after discharge from a geriatric evaluation and management unit (GEMU) in Taiwan.

METHODS

The present retrospective cohort study used data from the Veteran Affairs Comprehensive Geriatric Assessment from January 2015 to May 2016 for analysis. Data of patients aged 65 years and older with dementia or cognitive impairment at admission to the GEMU of Taipei Veterans General Hospital during the study period were retried for study. The Veteran Affairs Comprehensive Geriatric Assessment included demographic characteristics, Clinical Frailty Scale, Braden Scale, St. Thomas's Risk Assessment Tool in Falling Elderly Inpatients Scale, Cumulative Illness Rating Scale for Geriatrics, Barthel Index, Instrumental Activities of Daily Living, Mini-Mental State Examination, Geriatric Depression Scale-5 and Mini-Nutritional Assessment - Short Form, as well as common geriatric syndromes. All patients were categorized into the home care group and institutional care group based on their living arrangement before GEMU admissions. Six-month mortality and decline in Barthel Index were defined as adverse clinical outcomes.

RESULTS

Overall, data of 395 patients were used for analysis. The baseline comparisons showed that the institutional care group was more likely to be unmarried, have lower education, lower risk of falls and less polypharmacy, but more likely to experience functional decline at follow up than the home care group. Multivariate logistic regression showed that male (OR 3.59, 95% CI 1.04-12.38, P = 0.043) and higher Cumulative Illness Rating Scale for Geriatrics score (OR 4.08, 95% CI 1.49-11.19, P = 0.006) were associated with mortality, whereas the institutional care group (OR 0.30, 95% 0.09-0.99, P = 0.048) and lower Braden Scale (OR 0.80, 95% CI 0.67-0.94, P = 0.008) were protective against mortality. However, the institutional care group was independently associated with functional decline during the follow-up period (OR 2.19, 95% CI 1.12-4.29, P = 0.022).

CONCLUSIONS

Institutional care was associated with lower 6-month mortality risk for patients with dementia or cognitive impairment after discharge from the GEMU, but this group was more likely to experience functional decline. Further prospective study is required to clarify the clinical impact of living arrangements on long-term outcomes when people with dementia or cognitive impairment are admitted to acute hospitals. Geriatr Gerontol Int 2017: 17 (Suppl. 1): 44-49.

Recent global trends in the prevalence and incidence of dementia, and survival with dementia

BACKGROUND

Current projections of the scale of the coming dementia epidemic assume that the age- and sex-specific prevalence of dementia will not vary over time, and that population ageing alone (increasing the number of older people at risk) drives the projected increases. The basis for this assumption is doubtful, and secular trends (that is, gradual decreases or increases in prevalence over long-term periods) are perfectly plausible.

METHODS

We carried out a systematic review of studies of trends in prevalence, incidence and mortality for people with dementia, conducted since 1980.

RESULTS

We identified nine studies that had tracked dementia prevalence, eight that had tracked dementia incidence, and four that had tracked mortality among people with dementia. There was some moderately consistent evidence to suggest that the incidence of dementia may be declining in high-income countries. Evidence on trends in the prevalence of dementia were inconsistent across studies and did not suggest any clear overall effect. Declining incidence may be balanced by longer survival with dementia, although mortality trends have been little studied. There is some evidence to suggest increasing prevalence in East Asia, consistent with worsening cardiovascular risk factor profiles, although secular changes in diagnostic criteria may also have contributed.

CONCLUSIONS

We found no evidence to suggest that the current assumption of constant age-specific prevalence of dementia over time is ill-founded. However, there remains some uncertainty as to the future scale of the dementia epidemic. Population ageing seems destined to play the greatest role, and prudent policymakers should plan future service provision based upon current prevalence projections. Additional priorities should include investing in brain health promotion and dementia prevention programs, and monitoring the future course of the epidemic to chart the effectiveness of these measures.

Vitamin D2 suppresses amyloid-β 25-35 induced microglial activation in BV2 cells by blocking the NF-κB inflammatory signaling pathway

AIMS

Present emerging world is emphasizing the implication of vitamin D deficiency associated with development of inflammation and neurodegenerative disorder like Alzheimer's disease (AD). The chief neuropathological hallmark of AD is aggregation of amyloid-beta (Aβ) peptides surrounding microglial cells in human brain. Microglial activation plays a key role in inflammatory response and neuronal injury. Naturally abundant vitamin D2 (VD2) exhibiting anti-inflammatory activities are yet to explore more. This study has investigated the inhibitory effect of VD2 on inflammatory activities of BV2 microglial cells.

MAIN METHODS

Cellular compatibility of VD2 and Aβ25-35 protein in treated BV2 microglial cells were measured by CCK-8 assay. Induction of iNOS, COX-2 and NF-κB signaling cascade were measured by western blotting, whereas pro-inflammatory cytokines were measured by ELISA. In addition, generation of ROS was detected by fluorescence intensity.

KEY FINDINGS

Morphological observations showed that Aβ25-35 induced BV2 cells stimulation noticeably got reduced in VD2 pre-treated group at 24h time period. Anti-inflammatory activities of VD2 was observed demonstrating the inhibition of up-regulated iNOS and COX-2 protein expression further confirmed by attenuating the activated microglia released pro-inflammatory cytokines IL-1β, IL-6, TNF- α and ROS, while blocking the phosphorylation of NF-κB p65 in nucleus by preventing IκB-α degradation and phosphorylation in cytosol.

SIGNIFICANCE

The present study revealed that VD2 blocked the phosphorylation of NF-κB inflammatory signaling pathway in Aβ25-35 induced activated BV2 microglial cells by suppressing ROS generation and inflammatory cytokines. Our finding suggests that vitamin D2 has therapeutic potential against inflammation and Alzheimer's disease.

Depressive symptoms in spouse caregivers of dementia patients: A longitudinal study in South Korea

AIM

To investigate the association between spouse cognitive status and depressive symptoms in cohabiting spouses, and to further analyze how participation in social network-enhancing activities interplays in the objected relationship.

METHODS

Data from the Korean Longitudinal Study of Aging, 2006-2012, were used. A total of 2782 male and 2515 female married participants currently cohabiting with their partners were included in the baseline. The association between spouse cognitive status and depressive symptoms, measured using the Center for Epidemiological Studies Depression scale, was investigated through the generalized estimating equation model.

RESULTS

When setting the participants living with spouses of normal cognitive function as reference, participants living with spouses having mild dementia (male β 0.7349, P ≤ 0.0001; female β 0.8042, P ≤ 0.0001), and moderate and severe dementia (male β 1.1504, P ≤ 0.0001; female β 1.2462, P ≤ 0.0006) showed higher depression scores in a dose-response relationship. Additionally, male and female subjects participating in social network facilitating activities had lower increases in depression scores than their non-participating counterparts.

CONCLUSIONS

Spouse cognitive impairment is associated with increasing depression scores in cohabiting caregivers. Individuals not participating in social network-facilitating activities are more vulnerable to the negative mental health effects of spouse cognitive impairment. Hence, considering the increasing importance of late life depression and cognitive decline in aging societies, it is important to note the protective effects of social network and support in addressing the mental health of spouse caregivers. Geriatr Gerontol Int 2017; 17: 973-983.

Prevalence and incidence of Alzheimer's disease in Europe: A meta-analysis

BACKGROUND

A disease of unknown aetiology, Alzheimer's disease (AD) is the most common type of dementia. As the elderly population grows worldwide, the number of patients with AD also increases rapidly. The aim of this meta-analysis is to evaluate the prevalence and incidence of AD in Europe.

METHODOLOGY

We conducted a literature search on Medline, Scopus, and CINAHL Complete using the keywords «Alzheimer», «Alzheimer's disease», and «AD» combined with «prevalence», «incidence», and «epidemiology». A Bayesian random effects model with 95% credible intervals was used. The I² statistic was applied to assess heterogeneity.

RESULTS

The prevalence of Alzheimer's disease in Europe was estimated at 5.05% (95% CI, 4.73-5.39). The prevalence in men was 3.31% (95% CI, 2.85-3.80) and in women, 7.13% (95% CI, 6.56-7.72), and increased with age. The incidence of Alzheimer's disease in Europe was 11.08 per 1000 person-years (95% CI, 10.30-11.89). Broken down by sex, it was 7.02 per 1000 person-years (95% CI, 6.06-8.05) in men and 13.25 per 1000 person-years (95% CI, 12.05-14.51) in women; again these rates increased with age.

CONCLUSIONS

The results of our meta-analysis allow a better grasp of the impact of this disease in Europe.

Temporal Trends and Geographic Variations in Dementia Mortality in China Between 2006 and 2012: Multilevel Evidence From a Nationally Representative Sample

OBJECTIVES

We aimed to explore the temporal trends and geographic variations in dementia mortality in China.

MATERIALS AND METHODS

Annual dementia mortality counts (years 2006 to 2012) in 161 counties and districts (Disease Surveillance Points, DSP) were extracted from the nationally representative China Mortality Surveillance System and stratified by 5-year age group (aged >65), sex, and time. These counts were linked to annually adjusted denominator populations. Multilevel negative binomial regression with random intercepts and slopes were used to investigate spatiotemporal variation in dementia mortality.

RESULTS

Dementia mortality varied over 2-fold between DSPs (median rate ratio: 2.59). Significant variation in DSP slopes through time (variance 0.075, SE 0.020) indicated spatiotemporal variations. Mortality rates were significantly higher in the east (rate ratio 2.28; 95% confidence intervals, 1.45-3.60) compared with the north. There was a declining trend in 2 (east and northwest) of the 7 regions. Dementia mortality decreased by 15% in urban areas but increased by 24% in rural areas.

CONCLUSIONS

Our findings indicate that regional inequalities in dementia mortality are salient, and the increase in mortality rates in rural areas is an emerging public health challenge in China. Tailored preventive health strategies should be in place to narrow down this avoidable and wholly unnecessary inequality.

Incidence of Dementia over Three Decades in the Framingham Heart Study

BACKGROUND

The prevalence of dementia is expected to soar as the average life expectancy increases, but recent estimates suggest that the age-specific incidence of dementia is declining in high-income countries. Temporal trends are best derived through continuous monitoring of a population over a long period with the use of consistent diagnostic criteria. We describe temporal trends in the incidence of dementia over three decades among participants in the Framingham Heart Study.

METHODS

Participants in the Framingham Heart Study have been under surveillance for incident dementia since 1975. In this analysis, which included 5205 persons 60 years of age or older, we used Cox proportional-hazards models adjusted for age and sex to determine the 5-year incidence of dementia during each of four epochs. We also explored the interactions between epoch and age, sex, apolipoprotein E ε4 status, and educational level, and we examined the effects of these interactions, as well as the effects of vascular risk factors and cardiovascular disease, on temporal trends.

RESULTS

The 5-year age- and sex-adjusted cumulative hazard rates for dementia were 3.6 per 100 persons during the first epoch (late 1970s and early 1980s), 2.8 per 100 persons during the second epoch (late 1980s and early 1990s), 2.2 per 100 persons during the third epoch (late 1990s and early 2000s), and 2.0 per 100 persons during the fourth epoch (late 2000s and early 2010s). Relative to the incidence during the first epoch, the incidence declined by 22%, 38%, and 44% during the second, third, and fourth epochs, respectively. This risk reduction was observed only among persons who had at least a high school diploma (hazard ratio, 0.77; 95% confidence interval, 0.67 to 0.88). The prevalence of most vascular risk factors (except obesity and diabetes) and the risk of dementia associated with stroke, atrial fibrillation, or heart failure have decreased over time, but none of these trends completely explain the decrease in the incidence of dementia.

CONCLUSIONS

Among participants in the Framingham Heart Study, the incidence of dementia has declined over the course of three decades. The factors contributing to this decline have not been completely identified. (Funded by the National Institutes of Health.).