Undifferentiated dementia, Alzheimer's disease and vascular dementia: age- and gender-related incidence in Liverpool. The MRC-ALPHA Study

New cases of dementia are rising in elderly populations in Wales, UK

Dementia is one of the most common diseases in elderly populations, and older populations are one of the fastest growing groups globally. Consequently, the number of people developing and living with dementia is likely to grow. Using longitudinal medical records from Wales, UK between 1999 and 2018, diagnoses of overall dementia and common subtypes were combined with demographic data to assess numbers of new and existing cases per year. Data extraction resulted in 161,186 diagnoses from 116,645 individuals. Mean age at diagnosis of dementia increased over this period, resulting in fewer younger people with the disease. New cases of dementia have risen, as has the number of people living with dementia. Individuals with dementia are also living longer, even accounting for their older age. This may present a challenge for healthcare systems as the number of elderly people living with dementia is expected to continue to grow.

Prevalence of Possible Dementia in Patients with Maxillofacial Defects and Difficulty of Inserting Obturator in Maxillectomy Patients: Toward Better Provision of Supportive Care

As society ages, it is important to understand the prevalence of dementia and the difficulties of inserting prostheses in patients with maxillofacial defects in order to clarify issues in supportive care. We screened 183 patients for dementia using the revised Hasegawa's dementia scale (HDS-R) at the Clinic for Maxillofacial prosthetics, Tokyo Medical and Dental University, and investigated age and sex differences in HDS-R score. We asked 47 of the 183 participants about the difficulty of inserting a maxillofacial obturator prosthesis and collected subjective comments, information about the prosthesis, and data from five assessments. Multiple regression analysis was used to reveal factors associated with insertion difficulty. Overall, 8.7% of the participants were judged to have possible dementia. Men were more likely than women to have possible dementia, and the risk increased with age. Of the 47 participants, 26 reported difficulty inserting their prosthesis, 12 of whom attributed it to their oral defect. Fourteen patients advised following doctor's instructions to practice insertion in order to become accustomed to it. A lower HDS-R score had a significant impact on insertion difficulty. Cognitive function and difficulty inserting maxillary obturator prostheses should be considered in the provision of continuous supportive care to patients with maxillary defects.

Sex and gender differences in dementia

The dementia landscape has undergone a striking paradigm shift. The advances in understanding of neurodegeneration and proteinopathies has changed our approach to patients with cognitive impairment. Firstly, it has recently been shown that the various proteinopathies that are the cause of the dementia begin to build up long before the appearance of any obvious symptoms. This has cemented the idea that there is an urgency in diagnosis as it occurs very late in the pathophysiology of these diseases. Secondly, that accurate diagnosis is required to deliver targeted therapies, that is precision medicine. With this latter point, the realization that various factors of a person need to be considered as they may impact the presentation and progression of disease has risen to the forefront. Two of these factors aside from race and age are biological sex and gender (social construct), as both can have tremendous impact on manifestation of disease. This chapter will cover what is known and remains to be known on the interaction of sex and gender with some of the major causes of dementia.

Androgens' effects on cerebrovascular function in health and disease

Androgens affect the cerebral vasculature and may contribute to sex differences in cerebrovascular diseases. Men are at a greater risk for stroke and vascular contributions to cognitive impairment and dementia (VCID) compared to women throughout much of the lifespan. The cerebral vasculature is a target for direct androgen actions, as it expresses several sex steroid receptors and metabolizing enzymes. Androgens’ actions on the cerebral vasculature are complex, as they have been shown to have both protective and detrimental effects, depending on factors such as age, dose, and disease state. When administered chronically, androgens are shown to be pro-angiogenic, promote vasoconstriction, and influence blood-brain barrier permeability. In addition to these direct effects of androgens on the cerebral vasculature, androgens also influence other vascular risk factors that may contribute to sex differences in cerebrovascular diseases. In men, low androgen levels have been linked to metabolic and cardiovascular diseases including hypertension, diabetes, hyperlipidemia, and obesity, which greatly increase the risk of stroke and VCID. Thus, a better understanding of androgens’ interactions with the cerebral vasculature under physiological and pathological conditions is of key importance.

Incidence of dementia in the oldest-old and its relationship with age: The Monzino 80-plus population-based study

INTRODUCTION

Relationship between age and dementia at extreme old ages is still an open question, yet population-based studies in this high-risk age segment are rare.

METHODS

The Monzino 80-plus is a population-based study among residents 80 years and older in the Varese province, Italy. Of 1371 eligible individuals, 1294 (94.4%), of whom 64 are centenarians, were included in the incidence study.

RESULTS

Since 2002, 584 new cases of all-cause dementia were identified over 15 years. The overall incidence rate was 7.9 per 100 person-years. Dementia risk rose with age (IRR: 1.06), with the cubic model providing the best fit (R²  = 0.91-0.96). Cumulative incidences of dementia unadjusted and adjusted for competing mortality risk progressively diverged with age.

CONCLUSION

Dementia incidence also keeps rising in nonagenarians and centenarians. Slowing down in growing risk of developing dementia with age is mainly attributable to increasing competing risk of death and resulting selective survival of individuals at lower risk of dementia.

Sex differences in risk factors for vascular contributions to cognitive impairment & dementia

Vascular contributions to cognitive impairment and dementia (VCID) is the second most common cause of dementia. While males overall appear to be at a slightly higher risk for VCID throughout most of the lifespan (up to age 85), some risk factors for VCID more adversely affect women. These include female-specific risk factors associated with pregnancy related disorders (e.g. preeclampsia), menopause, and poorly timed hormone replacement. Further, presence of certain co-morbid risk factors, such as diabetes, obesity and hypertension, also may more adversely affect women than men. In contrast, some risk factors more greatly affect men, such as hyperlipidemia, myocardial infarction, and heart disease. Further, stroke, one of the leading risk factors for VCID, has a higher incidence in men than in women throughout much of the lifespan, though this trend is reversed at advanced ages. This review will highlight the need to take biological sex and common co-morbidities for VCID into account in both preclinical and clinical research. Given that there are currently no treatments available for VCID, it is critical that we understand how to mitigate risk factors for this devastating disease in both sexes.

Comparative effect of statins on the risk of incident Alzheimer disease

Objective

To investigate whether fungus-derived statins are associated with a lower risk of incident Alzheimer disease (AD) compared with synthetic statins using real-world clinical practice data.

Methods

We identified a population-based retrospective cohort of patients aged ≥60 years newly prescribed a statin between January 1, 1994, and December 31, 2012, and followed until March 31, 2015, using the UK Clinical Practice Research Datalink. Statins were consecutively classified according to their type, lipophilicity, and potency. For each group, we calculated the crude AD incidence rates per 1,000 person-years. Time-dependent Cox proportional hazards models adjusted for propensity score deciles were used to estimate hazard ratios (HRs) with 95% confidence interval (CIs) of incident AD associated with different statin categories.

Results

Over the 18-year study period, we identified 465,085 statin users, including 7,669 patients who developed AD during 2,891,268 person-years of follow-up (incidence rate 2.65 [95% CI 2.59–2.71] per 1,000 person-years). Compared to synthetic, fungus-derived statins were associated with an increased risk of AD (HR 1.09, 95% CI 1.03–1.15). Lipophilic statins also were associated with higher AD risk (HR 1.18, 95% CI 1.09–1.27) compared to hydrophilic statins, while statin potency did not modify the risk of AD (adjusted HR 1.03, 95% CI 0.98–1.08). The risk was further reduced in sensitivity analyses.

Conclusion

Fungus-derived and lipophilic statins were not associated with decreased incidence of AD compared to synthetic and hydrophilic statins. The modest variations in the risk of incident AD observed between statin characteristics needs to be evaluated in future studies on their possible heterogeneous neuroprotective effect.

Neuropathology of supercentenarians - four autopsy case studies

Supercentenarians (aged 110 years old or more) are extremely rare in the world population (the number of living supercentenarians is estimated as 47 in the world), and details about their neuropathological information are limited. Based on previous studies, centenarians (aged 100–109 years old) exhibit several types of neuropathological changes, such as Alzheimer’s disease and Lewy body disease pathology, primary age-related tauopathy, TDP-43 pathology, and hippocampal sclerosis. In the present study, we provide results from neuropathological analyses of four supercentenarian autopsy cases using conventional and immunohistochemical analysis for neurodegenerative disorders. In particular, we focused on the pathology of Alzheimer’s disease and Lewy body disease, as well as the status of hippocampal sclerosis, TDP-43 pathology, aging-related tau astrogliopathy, and cerebrovascular diseases. Three cases were characterized as an “intermediate” level of Alzheimer’s disease changes (NIA-AA guideline) and one was characterized as primary age-related tauopathy. TDP-43 deposits were present in the hippocampus in two cases. Neither Lewy body pathology nor hippocampal sclerosis was observed. Aging-related tau astrogliopathy was consistently observed, particularly in the basal forebrain. Small vessel diseases were also present, but they were relatively mild for cerebral amyloid-beta angiopathy and arteriolosclerosis. Although our study involved a small number of cases, the results provide a better understanding about human longevity. Neuropathological alterations associated with aging were mild to moderate in the supercentenarian brain, suggesting that these individuals might have some neuroprotective factors against aging. Future prospective studies and extensive molecular analyses are needed to determine the mechanisms of human longevity.

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.

Psychosocial interventions in Alzheimer's disease and amnestic mild cognitive impairment: evidence for gender bias in clinical trials

BACKGROUND

Alzheimer's disease (AD) affects twice as many women as men. Gender differences in symptom profile, living conditions, coping style and response might affect the outcome of psychosocial interventions (PSIs).

OBJECTIVES

Our aim was to review gender differences in the available high-quality phase III trials on PSI in AD and amnestic mild cognitive impairment (aMCI) by considering the gender ratio in the investigated samples.

DESIGN

Randomized controlled trials published in 2000-2012 were stepwise analyzed by statistically testing the representativeness of the gender ratio and examining reported gender differences.

RESULTS

Forty-five studies (62% of 73 studies) reported gender ratios for each subsample and were included. In these studies, females were underrepresented in the control groups. In the 14 studies (19%) reporting analyses of gender differences, women were underrepresented in both intervention and control groups. However, in the six studies (8%) reporting significant gender differences in outcome, gender distribution was in accordance with prevalence rates.

CONCLUSION

Current evidence is insufficient for reliable conclusions on gender differences in PSI outcome in AD and aMCI, as 81% of the available clinical trials either not reported the gender ratio of their samples, or underrepresent females. Further research is needed addressing gender differences, and clinical trials should routinely control for gender bias.

Gastritis May Boost Odds of Dementia

INTRODUCTION

Given the high prevalence of dementia and its devastating consequences, identifying risk factors for dementia is a public health priority. The present study aims to assess whether gastritis increases the odds of dementia.

METHODOLOGY

The data for this study, consisting of 2926 community-dwelling older adults, were obtained from the National survey entitled "Mental Health and Quality of Life of Older Malaysians." Dementia was diagnosed using the Geriatric Mental State-Automated Geriatric Examination for Computer-Assisted Taxonomy.

RESULTS

Prevalence of dementia was considerably higher among older adults with gastritis (29.5%) compared to those without gastritis (13.2%). After adjusting for age, gender, marital status, educational attainment, hypertension, stroke, and diabetes, gastritis was significantly associated with more than twice odds of dementia (adjusted odds ratio = 2.42, P < .001, 95% confidence interval = 1.68-3.49).

CONCLUSIONS

The findings from this population-based observational study showing evidence that gastritis may increase the risk of dementia provide avenue for further inquiries into dementia.

Socioeconomic status and survival among older adults with dementia and depression

BACKGROUND

People from lower socioeconomic groups have a higher risk of mortality. The impact of low socioeconomic status on survival among older adults with dementia and depression remains unclear.

AIMS

To investigate the association between socioeconomic status and mortality in people with dementia and late-life depression in China.

METHOD

Using Geriatric Mental Status - Automated Geriatric Examination for Computer Assisted Taxonomy (GMS-AGECAT) we interviewed 2978 people aged ⩾60 years in Anhui, China. We characterised baseline socioeconomic status and risk factors and diagnosed 223 people with dementia and 128 with depression. All-cause mortality was followed up over 5.6 years.

RESULTS

Individuals with dementia living in rural areas had a three times greater risk of mortality (multivariate adjusted hazard ratio (HR) = 2.96, 95% CI 1.45-6.04) than those in urban areas, and for those with depression the HR was 4.15 (95% CI 1.59-10.83). There were similar mortality rates when comparing people with dementia with low v. high levels of education, occupation and income, but individuals with depression with low v. high levels had non-significant increases in mortality of 11%, 50% and 55% respectively

CONCLUSIONS

Older adults with dementia and depression living in rural China had a significantly higher risk of mortality than urban counterparts. Interventions should be implemented in rural areas to tackle survival inequality in dementia and depression.

Depression, subthreshold depression and comorbid anxiety symptoms in older Europeans: results from the EURODEP concerted action

BACKGROUND

In the epidemiology of late life depression, few insights are available on the co-occurrence of subthreshold depression and comorbid symptoms of anxiety. The current study aims to describe prevalence patterns of comorbid anxiety symptoms across different levels of depression in old age, and to describe the burden of depressive symptoms and functional disability across patterns of comorbidity.

METHODS

Respondents were older adults in the community, age 65-104 (N=14,200), from seven European countries, with in total nine study centres, collaborating in the EURODEP concerted action. Depression and anxiety were assessed using the Geriatric Mental State examination (GMS-AGECAT package), providing subthreshold level and case-level diagnoses. Presence of anxiety symptoms was defined as at least three distinct symptoms of anxiety. Number of depressive symptoms was assessed with the EURO-D scale.

RESULTS

The prevalence of anxiety symptoms amounts to 32% for respondents without depression, 67% for those with subthreshold depression, and 87% for those with case-level depression. The number of depressive symptoms is similar for those with subthreshold-level depression with comorbid anxiety, compared to case-level depression without symptoms of anxiety. In turn, at case level, comorbid symptoms of anxiety are associated with higher levels of depressive symptoms and more functional disability.

LIMITATIONS

GMS-AGECAT is insufficiently equipped with diagnostic procedures to identify specific types of anxiety disorders.

CONCLUSIONS

Anxiety symptoms in late life depression are highly prevalent, and are likely to contribute to the burden of symptoms of the depression, even at subthreshold level.

Reduced prevalence of cognitive impairment in families with exceptional longevity

IMPORTANCE

Family studies of centenarians and long-lived persons have found substantial familial aggregation of survival to extreme ages; however, the extent to which such familial longevity is characterized by cognitively intact survival is not established.

OBJECTIVE

To determine whether families with exceptional longevity are protected against cognitive impairment consistent with Alzheimer disease.

DESIGN

Cross-sectional analysis.

SETTING

Multisite study in New York, Massachusetts, Pennsylvania, and Denmark.

PARTICIPANTS

A total of 1870 individuals (1510 family members and 360 spouse controls) recruited through the Long Life Family Study.

MAIN OUTCOME AND MEASURE

Prevalence of cognitive impairment based on a diagnostic algorithm validated using the National Alzheimer's Coordinating Center data set.

RESULTS

The cognitive algorithm classified 546 individuals (38.5%) as having cognitive impairment consistent with Alzheimer disease. Long Life Family Study probands had a slightly but not statistically significant reduced risk of cognitive impairment compared with spouse controls (121 of 232 for probands vs 45 of 103 for spouse controls; odds ratio = 0.7; 95% CI, 0.4-1.4), whereas Long Life Family Study sons and daughters had a clearly reduced risk of cognitive impairment (11 of 213 for sons and daughters vs 28 of 216 for spouse controls; odds ratio = 0.4; 95% CI, 0.2-0.9). Restriction to nieces and nephews in the offspring generation attenuated this effect (37 of 328 for nieces and nephews vs 28 of 216 for spouse controls; odds ratio = 0.8; 95% CI, 0.4-1.4).

CONCLUSIONS AND RELEVANCE

Rates of cognitive impairment characteristic of Alzheimer disease were relatively high. In the proband generation, rates were comparable across family members and spouse controls, whereas sons and daughters of probands had significantly lower rates than spouse controls. Results suggest a delayed onset of cognitive impairment in families with exceptional longevity, but assessment of age-specific incidence rates is required to confirm this hypothesis.

Smell identification function as a severity and progression marker in Alzheimer's disease

BACKGROUND

Olfactory dysfunction, impaired smell identification in particular, is known as a diagnostic and a marker of conversion in Alzheimer's disease (AD). We aimed to evaluate the associations of olfactory identification impairments with cognition, illness severity, and progression in AD patients.

METHODS

Fifty-seven outpatients with late onset mild to moderate AD and 24 elderly non-demented controls (NDC) were assessed, at baseline and after three months, for Mini-Mental State Examination (MMSE), University of Pennsylvania Smell Identification Test (UPSIT), and Bristol Activities of Daily Living and Neuropsychiatry Inventory. AD participants were classified as Rapid Cognitive Decliners (RCD) defined on a priori with a loss of ≥2 points in MMSE within the previous six months.

RESULTS

AD participants had lower olfactory scores than NDC. RCD had lower olfaction scores compared with Non-Rapid Cognitive Decliners (NRCD). Although the baseline UPSIT scores were associated with baseline MMSE scores, it did not interact significantly with change in MMSE over the follow-up period. Using a median split for olfactory scores, the AD participants were classified as Rapid Olfactory Progressors (ROP) (UPSIT ≤ 15) and Slow Olfactory Progressors correlating significantly with RCD/NRCD groups. The ROP group with higher olfactory impairment indicated more symptomatic illness or severity, i.e. lower cognition, higher functional dependence, and presence of behavioral symptoms.

CONCLUSIONS

Our study supports association of smell identification function with cognition and its utility as an adjunct clinical measure to assess severity in AD. Further work, including larger longitudinal studies, is needed to explore its value in predicting AD progression.

Challenges of diagnosing dementia in the oldest old population

People aged 90 and older are the fastest growing age group in most parts of the world. Since the prevalence of dementia has been shown to increase exponentially after the age of 65, there is an acceptance that the oldest old population has a high burden of dementia; however, there is a lack of consensus on how best to diagnose dementia in this population. This review summarizes the various approaches to diagnosing dementia and the prevalence and incidence rates of dementia that have been reported. We also summarize the literature on cognitive and functional performance and biomarkers for dementia and discuss the limitations to interpretation of these data. Finally, we make recommendations for both researchers and clinicians who intend to diagnose dementia in the oldest old population.

Association between environmental tobacco smoke exposure and dementia syndromes

OBJECTIVES

Environmental tobacco smoke (ETS) has a range of adverse health effects, but its association with dementia remains unclear and with dementia syndromes unknown. We examined the dose-response relationship between ETS exposure and dementia syndromes.

METHODS

Using a standard method of GMS, we interviewed 5921 people aged ≥60 years in five provinces in China in 2007-2009 and characterised their ETS exposure. Five levels of dementia syndrome were diagnosed using the Automated Geriatric Examination for Computer Assisted Taxonomy instrument. The relative risk (RR) of moderate (levels 1-2) and severe (levels 3-5) dementia syndromes among participants exposed to ETS was calculated in multivariate adjusted regression models.

RESULTS

626 participants (10.6%) had severe dementia syndromes and 869 (14.7%) moderate syndromes. Participants exposed to ETS had a significantly increased risk of severe syndromes (adjusted RR 1.29, 95% CI 1.05 to 1.59). This was dose-dependently related to exposure level and duration. The cumulative exposure dose data showed an adjusted RR of 0.99 (95% CI 0.76 to 1.28) for >0-24 level years of exposure, 1.15 (95% CI 0.93 to 1.42) for 25-49 level years, 1.18 (95% CI 0.87 to 1.59) for 59-74 level years, 1.39 (95% CI 1.03 to 1.84) for 75-99 level years and 1.95 (95% CI 1.34 to 2.83) for ≥100 level years. Significant associations with severe syndromes were found in never smokers and in former/current smokers. There were no positive associations between ETS and moderate dementia syndromes.

CONCLUSIONS

ETS should be considered an important risk factor for severe dementia syndromes. Avoidance of ETS may reduce the rates of severe dementia syndromes worldwide.

Epidemiology of Alzheimer disease

The global prevalence of dementia has been estimated to be as high as 24 million, and is predicted to double every 20 years until at least 2040. As the population worldwide continues to age, the number of individuals at risk will also increase, particularly among the very old. Alzheimer disease is the leading cause of dementia beginning with impaired memory. The neuropathological hallmarks of Alzheimer disease include diffuse and neuritic extracellular amyloid plaques in brain that are frequently surrounded by dystrophic neurites and intraneuronal neurofibrillary tangles. The etiology of Alzheimer disease remains unclear, but it is likely to be the result of both genetic and environmental factors. In this review we discuss the prevalence and incidence rates, the established environmental risk factors, and the protective factors, and briefly review genetic variants predisposing to disease.

A multicentre community-based study of dementia cases and subcases in older people in China--the GMS-AGECAT prevalence and socio-economic correlates

BACKGROUND

Previous studies indicated overall relatively low prevalence of dementia in older people in China, which may be biased by studied samples or methods. We determined the prevalence of dementia cases and subcases in China and examined their socio-economic correlates.

METHODS

Using the Geriatric Mental State interview, we examined random samples of 2917 participants aged ≥ 65 years in urban and rural Anhui, China in 2001-2003, and 3327 in four other provinces in 2008-2009. Dementia cases and subcases were diagnosed by Geriatric Mental State-Automated Geriatric Examination for Computer Assisted Taxonomy.

RESULTS

Age-standardised prevalence for cases and subcases of dementia in the Anhui elders was 7.20% (95%CI 6.29%-8.20%) and 10.5% (9.38%-11.6%), and in the four provinces, 9.86% (8.80%-10.9%) and 8.51% (7.51%-9.52%). The matched figures among the participants who were literate were 3.05% (2.08%-4.02%) and 10.0% (8.38%-11.6%), and 4.92% (3.89%-5.96%) and 6.76% (5.55%-7.96%), respectively. There were higher prevalence rates of dementia cases and subcases in the rural elders than in the urban. Both the Anhui and four-province studies showed an obvious association of dementia with higher and lower incomes among elders who had lower educational levels or had the lowest occupational class. The highest risk of dementia was found in those who were illiterate but had the highest income or had the job of business/nonmanual labouring.

CONCLUSIONS

People in China have a higher prevalence of dementia than previously reported. Its U-shaped relationship with income and the excess subcases prevalence predicates a significant burden of disease, both now and for the future, suggesting preventive strategy for dementia in China.

Neuropsychological screening performance and the association with activities of daily living and instrumental activities of daily living in dementia: baseline and 18- to 24-month follow-up

OBJECTIVE

The use of neuropsychological assessment beyond diagnosis is related partly to the extent to which it can indicate everyday function. This study investigates whether the associations between neuropsychological functioning, activities of daily living (ADL) and instrumental activities of daily living (IADL) change over an 18- to 24-month follow-up, exploring whether these change with dementia progression.

METHOD

Thirty-four patients with probable Alzheimer's disease were assessed at baseline and again after between 18 and 24 months. Neuropsychological function was assessed using the revised Cambridge Cognitive Examination, which includes in it the Mini mental state examination and an executive functions scale. ADL and IADL were also measured, together with background neuropsychiatric features by using the Neuropsychiatric Inventory.

RESULTS

Pearson correlations between the measures of daily functioning and cognitive abilities and neuropsychiatric symptoms showed that initially neuropsychological test results tended to correlate with IADL rather than ADL measures. Neuropsychiatric symptoms were not correlated whether IADL or ADL. At follow-up, none of the neuropsychological function measures correlated with IADL or ADL, but neuropsychiatric symptoms were correlated with IADL.

CONCLUSIONS

At baseline, neuropsychological function is associated with IADL but not ADL. At follow-up, the association between neuropsychological function and IADL diminishes, and associations between neuropsychiatric disturbances and IADL emerge.

Depression and parkinsonism in older Europeans: results from the EURODEP concerted action

OBJECTIVE

The prevalence rate of depression among patients with Parkinson's disease (PD) has been estimated at 25%, although prevalence figures range between 7-76%. Relatively few studies on PD and depression are based on random samples in the general population. Some depressive symptoms can also be understood as symptoms of parkinsonism, and the current study aims to describe which 'overlap' symptoms can be identified in a community sample.

METHODS

Data are employed from the EURODEP collaboration. Nine study centres, from eight western European countries, provided data on depression (most GMS-AGECAT), depressive symptoms (EURO-D items and anxiety), parkinsonism (self-report of PD or clinical signs of PD), functional disability and dementia diagnosis.

RESULTS

Data were complete for 16 313 respondents, aged 65 and older; 306 (1.9%) reported or had signs of parkinsonism. The rate of depression was about twice as high among respondents with parkinsonism (unadjusted Odds Ratio 2.44, 95% Confidence Interval 1.88-3.17), also among those without functional disability. 'Overlap' symptoms between parkinsonism and depression, were represented by motivation and concentration problems, appetite problems and especially the symptom of fatigue (energy loss). However, principal component analysis showed that these 'overlap' symptoms loaded on different factors of the EURO-D scale.

CONCLUSIONS

As among clinical patients with PD, depression is highly common in community dwelling older people with parkinsonism, even among those without functional disability. Although fatigue did not strongly relate to motivational symptoms, both types of 'overlap' symptoms possibly trigger a final common pathway towards a full depressive syndrome.

Who will be eligible? An investigation of the dementia population eligible for cholinesterase treatment following the change in NICE guidance

OBJECTIVES

Investigate the impact of the changes in eligibility within England and Wales (E&W) for prescription within the UK National Health Service for treatment of Alzheimer's disease (AD).

METHODS

A population-based study in England and Wales with 13,004 individuals measured with MMSE at baseline was used to examine the distributions of individuals within eligibility criteria. Information obtained from informants enabled classification of the study defined dementia cases to ICD10 diagnosis of subtype (AD, dementia with vascular risk, both or other).

RESULTS

Fifty six per cent of dementia patients (representing 323,000 individuals in E&W) fall into the new MMSE criteria band. A further 120,000, 20% of dementia patients, are estimated to have disease that is considered too mild for treatment. Further examination of type of dementia showed that those with mixed AD and vascular dementia had similar proportions of dementia cases within the treatable MMSE group as the subgroup with AD alone, though with mixed disease individuals more often score below the lower threshold. There is substantial instability in the eligibility groupings over a short time period.

CONCLUSIONS

The population impact of new NICE criteria of excluding high MMSE scores is to exclude one in five individuals with AD and a further one in ten of those with a mixed disease. Changing the guidance has almost balanced the loss of treatment for the high MMSE group (13%) with the introduction of treatment for those scoring 10/11 (11%).

Severity of depression and risk for subsequent dementia: cohort studies in China and the UK

BACKGROUND

Depression and dementia often exist concurrently. The associations of depressive syndromes and severity of depression with incident dementia have been little studied.

AIMS

To determine the effects of depressive syndromes and cases of depression on the risk of incident dementia.

METHOD

Participants in China and the UK aged > or =65 years without dementia were interviewed using the Geriatric Mental State interview and re-interviewed 1 year later in 1254 Chinese, and 2 and 4 years later in 3341 and 2157 British participants respectively (Ageing in Liverpool Project Health Aspects: part of the Medical Research Council - Cognitive Function and Ageing study).

RESULTS

Incident dementia was associated with only the most severe depressive syndromes in both Chinese and British participants. The risk of dementia increased, not in the less severe cases of depression but in the most severe cases. The multiple adjusted hazard ratio (HR)=5.44 (95% CI 1.67-17.8) for Chinese participants at 1-year follow-up, and HR=2.47 (95% CI 1.25-4.89) and HR=2.62 (95% CI 1.18-5.80) for British participants at 2- and 4-year follow-up respectively. The effect was greater in younger participants.

CONCLUSIONS

Only the most severe syndromes and cases of depression are a risk factor for dementia.

Yield of a new method to detect cognitive impairment in general practice

OBJECTIVE

To examine whether a new screening method that identified patients with cognitive impairment who needed further examination on the presence of dementia yielded patients who were not detected by their general practitioner (GP), and to identify factors associated with GPs' awareness of patients identified by the screening.

METHODS

Cross-sectional comparison between two methods used to identify dementia symptoms: (1) usual identification of dementia by GPs; (2) a two-stage screening to identify cognitive impairment. The two methods were implemented on the same older general practice population. The study was set in primary care practices in the Netherlands. The participants were 44 GPs and 2,101 general practice patients aged 75+ who lived at home. The following measurements were used: (1) yield of the screening; (2) determinants of GPs' awareness of patients identified by the screening.

RESULTS

The two-stage screening yielded 117 patients with cognitive impairment who needed further examination; in most cases (n = 82, 70.1%) their GP was unaware of the symptoms. Among patients identified by the screening, GPs' awareness was associated with co-morbidity of chronic diseases [odds ratio (OR) = 3.19; 95% Confidence Interval (CI) = 1.25 to 8.15], depressive symptoms (OR = 0.41; 95% CI = 0.17 to 0.99), and cognitive functioning (per point on the MMSE, OR = 0.88; 95% CI = 0.79 to 0.98).

CONCLUSION

A two-stage screening method and increased alertness for cognitive impairment and dementia among patients with depressive symptoms may improve detection rate of dementia in general practice.

Impact of neuroprotection on incidence of Alzheimer's disease

Converging evidence suggests that high levels of education and intellectual activity increase the cognitive reserve and reduce the risk of dementia. However, little is known about the impact that different neuroprotective strategies may have on the incidence of Alzheimer's disease. Using a simple mathematical regression model, it is shown here that age-specific counts of basic cognitive units (surrogate of neurons or synapses) in the normal population can be estimated from Alzheimer's incidence rates. Hence, the model can be used to test the effect of neuroprotection on Alzheimer's incidence. It was found that the number of basic cognitive units decreases with age, but levels off in older people. There were no gender differences after correcting for survival. The model shows that even modest neuroprotective effects on basic cognitive units can lead to dramatic reductions in the number of Alzheimer's cases. Most remarkably, a 5% increase in the cognitive reserve would prevent one third of Alzheimer's cases. These results suggest that public health policies aimed at increasing the cognitive reserve in the general population (e.g., implementing higher levels of education) are likely the most effective strategy for preventing Alzheimer's disease.

Differential CSF butyrylcholinesterase levels in Alzheimer's disease patients with the ApoE epsilon4 allele, in relation to cognitive function and cerebral glucose metabolism

Butyrylcholinesterase (BuChE) is increased in the cerebral cortex of Alzheimer's disease (AD) patients, particularly those carrying epsilon4 allele of the apolipoprotein E gene (ApoE) and certain BuChE variants that predict increased AD risk and poor response to anticholinesterase therapy. We measured BuChE activity and protein level in CSF of eighty mild AD patients in relation to age, gender, ApoE epsilon4 genotype, cognition and cerebral glucose metabolism (CMRglc). BuChE activity was 23% higher in men than women (p<0.03) and 40-60% higher in ApoE epsilon4 negative patients than in those carrying one or two epsilon4 alleles (p<0.0004). CSF BuChE level correlated with cortical CMRglc. Patients with high to moderate CSF BuChE showed better cognitive function scores than others. We hypothesize that CSF BuChE varies inversely with BuChE in cortical amyloid plaques. Thus, low BuChE in a patient's CSF may predict extensive incorporation in neuritic plaques, increased neurotoxicity and greater central neurodegeneration.

Risk factors for Alzheimer's disease in Russia: a case-control study

No reliable data on risk factors of Alzheimer's disease (AD) are available in Russia. We aimed to evaluate the relative importance of various putative environmental and medical risk factors of AD in a Russian population. We conducted a hospital-based case-control study. Two hundred and sixty consecutive AD patients and an equal number of cognitive impairment-free control subjects matched for sex, age, level of education and place of birth selected from nursing homes and other long-term healthcare facilities in the Novosibirsk region for the period from 1998 to 2002 were examined. A conditional logistic regression analysis was employed to calculate odds ratios (OR) and corresponding 95% confidence intervals (CI) for various putative risk factors. Of the 260 patients with AD, 187 (72%) were females. Patients' age varied from 40 to 89 years (mean +/- SD: 69.2 +/- 7.7 years). The majority of the patients (77%) had secondary education and 12% had university education. Risk factors independently associated with AD were family history of parkinsonism among first-degree relatives (OR = 4.2; 95% CI 1.2-15.1), hypothyroidism (OR = 2.7; 95% CI 1.1-6.7), and history of head trauma with loss of consciousness (OR = 1.7; 95% CI 1.0-2.8). The most important risk factors for AD in the Russian community are family history of parkinsonism, hypothyroidism and a history of head trauma with loss of consciousness. These findings have implications for developing preventive strategies of AD.

Risk factors and early signs of Alzheimer's disease in a family study sample. Risk of AD

OBJECTIVE

Several predictors of Alzheimer's disease (AD) have been identified. However, the relevance and independent contribution of risk factors and of possible early signs such as mild cognitive impairment and subjective memory impairment on the development of AD has not been investigated prospectively in a cohort of non-demented elderly including first-degree relatives of AD subjects.

METHOD

The development of AD was investigated in 757 non-demented elderly. Initial diagnoses were made from personal interviews. Information on 633 subjects after 4.7 +/- 1.2 years (mean +/- SD) was obtained either from personal or family history interviews. Using forward logistic regression analysis, predictors were identified by comparing their presence in 38 subjects who developed AD and 577 subjects who remained non-demented.

RESULTS

The most important predictors of later Alzheimer's disease were increased age (Odds ratio OR = 1.086/additional year, p < 0.001), initial subjective memory complaints (OR = 2.68, p = 0.019), initial mild cognitive impairment (OR = 2.51, p = 0.032) and female gender (OR = 2.84, p = 0.069). Exploratory analysis revealed that previous depression after the age of 60 years (OR = 2.37, p = 0.033) and the presence of the apolipoprotein E4 allele (OR = 2.49, p = 0.043) individually predicted new AD during follow-up. A positive family history of AD (i. e. being a first degree relative of a subject suffering from AD) did not significantly influence the development of AD (p > 0.2).

CONCLUSIONS

Increased age, the presence of mild cognitive impairment, subjective memory impairment and gender are the most relevant independent predictors of later Alzheimer's disease that may be used in combination for clinical prediction of AD.

Incidence of dementia in very elderly individuals: a clinical, neuropathological and molecular genetic study

AIMS

To evaluate the effect of medical record use on figures for the incidence of dementia and the effect of apolipoprotein E (APOE) polymorphism on this incidence and neuropathologically defined Alzheimer's disease (AD) in very elderly individuals.

METHODS

Cognitive functions were examined in a cohort of 328 (92% of the very elderly people of a town participated in this study) nondemented Finnish elderly individuals 85 years of age or more in 1991. The examination was repeated in survivors in 1994, 1996, 1999 and 2001. Medical notes and social work records were evaluated. All these individuals were genotyped for APOE. Neuropathological analysis of AD-type pathology was performed on 159 of 303 subjects who died during the follow-up.

RESULTS

Age group, gender or APOE did not significantly affect the incidence of dementia, which was over 20% higher (85 vs. 69 per 1,000 person-years) if the cognitive status at death was ascertained by medical and social work records than without this evaluation. The APOE upsilon4 allele was highly significantly (p=0.002) and age almost significantly (p=0.06) associated with neuropathological AD in nondemented individuals.

CONCLUSIONS

Medical records should be analyzed in studies on the incidence of dementia in very elderly individuals. APOE polymorphism does not affect the incidence of dementia in this age group. However, clinical dementia diagnosis in very elderly individuals does not necessarily correlate well with the presence of neuropathological AD which, even in this age group, is significantly associated with the APOE upsilon4 allele.

The incidence of dementia in England and Wales: findings from the five identical sites of the MRC CFA Study

BACKGROUND

Although incidence of dementia is known to vary between nations, variation within country has not been explored because most incidence studies are single site or have insufficient numbers to compare sites. Few countries have conducted multisite incidence studies in order to facilitate national comparisons. This study aims to provide robust measures of the variation of the incidence of dementia across sites within England and Wales and produce overall estimates by age and sex.

METHODS AND FINDINGS

The Medical Research Council Cognitive Function and Ageing Study used identical methodology in five diverse sites across the United Kingdom, each with different risk patterns and mortality rates. Incidence has been estimated using likelihood-based methods between the first two waves of interviews. Incidence rates rise with age, particularly above the age of 75 y, from 6.7 [corrected] (95% confidence interval, 3.8 [corrected]-12.4 [corrected]) per 1,000 person years at age 65-69 y to 68.5 [corrected] (95% confidence interval, 52.5 [corrected]-88.1 [corrected]) per 1,000 person years at age 85 y and above. The rate of increase for both sexes is marked, and continues into the oldest age groups. Hence, it is estimated that approximately 163,000 [corrected] new cases of dementia occur in England and Wales each year. There is no convincing evidence of variation across sites, and incidence rates do not reflect the variations in the prevalence of possible risk factors in these sites.

CONCLUSION

There is no evidence, within England and Wales, of variation in dementia incidence across sites. Dementia incidence rates do not tail off at the oldest ages.

Dementia-free centenarians

BACKGROUND

A small percentage of centenarians, about 15-25%, are functionally cognitively intact. Among those who are not cognitively intact at 100, approximately 90% delayed the onset of clinically evident impairment at least until the average age of 92 yr.

OBJECTIVE

To review current and past findings related to the prevalence and incidence of dementia amongst the exceptionally long-lived.

METHODS

Findings from the various centenarian studies, world-wide, are reviewed.

RESULTS

Neuropsychological and neuropathological correlations thus far suggest that there are centenarians who demonstrate no evidence of neurodegenerative disease. There also appear to be centenarians who despite the substantial presence of neuropathological markers of Alzheimer's disease did not meet clinical criteria for having dementia, thus suggesting the existence of cognitive reserve. Epigenic studies suggest a significant familial component to these survival advantages.

CONCLUSION

Centenarians are of scientific interest as a human model of relative resistance to dementia.

Gender differences in glutathione metabolism in Alzheimer's disease

The mechanism underlying Alzheimer's disease (AD), an age-related neurodegenerative disease, is still an area of significant controversy. Oxidative damage of macromolecules has been suggested to play an important role in the development of AD; however, the underlying mechanism is still unclear. In this study, we showed that the concentration of glutathione (GSH), the most abundant intracellular free thiol and an important antioxidant, was decreased in red blood cells from male AD patients compared with age- and gender-matched controls. However, there was no difference in blood GSH concentration between the female patients and female controls. The decrease in GSH content in red blood cells from male AD patients was associated with reduced activities of glutamate cysteine ligase and glutathione synthase, the two enzymes involved in de novo GSH synthesis, with no change in the amount of oxidized glutathione or the activity of glutathione reductase, suggesting that a decreased de novo GSH synthetic capacity is responsible for the decline in GSH content in AD. These results showed for the first time that GSH metabolism was regulated differently in male and female AD patients.

Sociodemographic Factors Associated With Incidence of Dementia Among Senior Citizens of a Small Town in Japan

Dementia is one of the common causes that lead to dependence of senior citizens in daily living. Clarifying the features of the elderly with dementia is instrumental in planning for their effective care and support in a community, and for attempts at prevention. Our purpose was to investigate the impact of sociodemographic factors among the elderly with the presumptive diagnosis of dementia. We carried out a survey annually from 1998 to 2002 in a dynamic cohort of community-dwelling individuals aged 65 years or older. Of the 945 subjects, 782 were eligible for study because at the first interview they were asymptomatic for dementia and not institutionalized. We found no significant difference in a 5-year average incidence rate between genders. However, the risk of developing dementia increased with age. The study population was categorized into three groups of living arrangement: those living with spouse and others, those living alone, and those living with persons other than the spouse. The incidence rate of dementia among the elderly who lived with spouse and others was significantly lower than for those among the other groups. This was also notable in the subjects without a history of stroke, even after adjustment for age and gender. This result indicates that living with spouse might have an important benefit in reducing the risk of developing dementia, although this effect would vary with the type of dementing disease. We suggest that preventive measures in clinical and community care of the elderly should focus on interactive social conditions such as living environments.

Prevalence of dementia in older latinos: the influence of type 2 diabetes mellitus, stroke and genetic factors

OBJECTIVES

To estimate dementia prevalence in older Mexican Americans, determine the distribution of dementia by etiology, and evaluate the contribution of type 2 diabetes mellitus, stroke, and apolipoprotein E (ApoE) genotype to dementia.

DESIGN

Analysis of baseline data from an epidemiological cohort study.

SETTING

Sacramento Valley, California.

PARTICIPANTS

One thousand seven hundred eighty-nine Latinos aged 60 and older residing in targeted census tracts during 1998-99.

MEASUREMENTS

Each subject was interviewed and screened for dementia and cardiovascular risk factors and diseases. Fasting blood samples were drawn for glucose, insulin, and lipids. Buccal cells were obtained for genetic analysis of ApoE. A three-stage process of screening was used to diagnose dementia, including cognitive testing, a clinical examination, and imaging to determine etiology. Presence of dementia was established according to National Institute of Neurological Disorders and Stroke/Alzheimers and Related Disorders Association criteria and California Alzheimer's Disease Diagnostic and Treatment Criteria.

RESULTS

Overall dementia prevalence was 4.8%. Prevalence in those aged 85 and older was 31%. Education and Anglo cultural orientation was negatively associated with dementia risk. Risk of dementia was nearly eight times higher in those with both type 2 diabetes mellitus and stroke. Forty-three percent of dementia was attributable to type 2 diabetes mellitus, stroke, or a combination of the two. ApoE allele frequency was E2 5.9%, E3 90.1%, and E4 4%. Those with any E4 and 4-4 combinations had a higher risk for dementia than those with the E3-3 combination.

CONCLUSIONS

Dementia prevalence in this ethnic group is similar to that reported in Canadian and European studies but lower than in Caribbean-Hispanics residing in the United States. The etiological fraction of dementia attributable to type 2 diabetes mellitus and stroke is substantial and points toward the need for intervention research and treatment with the goal of reducing neurological sequelae in groups with high prevalence of type 2 diabetes mellitus. The allele frequency of ApoE was similar to that in other published studies on Mexican Americans. The low frequency of the E4 allele may contribute to the difference in etiology of dementia in older Mexican Americans and older people of European background. Dementia in this ethnic group may be related to preventable causes, with a smaller genetic component than in Europeans.

Relative frequencies of Alzheimer disease, Lewy body, vascular and frontotemporal dementia, and hippocampal sclerosis in the State of Florida Brain Bank

Alzheimer disease (AD) is the most common dementing illness in the elderly, but there is equivocal evidence regarding the frequency of other disorders such as Lewy body disease (LBD), vascular dementia (VaD), frontotemporal dementia (FTD), and hippocampal sclerosis (HS). This ambiguity may be related to factors such as the age and gender of subjects with dementia. Therefore, the objective of this study was to calculate the relative frequencies of AD, LBD, VaD, FTD, and HS among 382 subjects with dementia from the State of Florida Brain Bank and to study the effect of age and gender on these frequencies. AD was the most frequent pathologic finding (77%), followed by LBD (26%), VaD (18%), HS (13%), and FTD (5%). Mixed pathology was common: Concomitant AD was present in 66% of LBD patients, 77% of VaD patients, and 66% of HS patients. The relative frequency of VaD increased with age, whereas the relative frequencies of FTD and LBD declined with age. Males were overrepresented among those with LBD, whereas females were overrepresented among AD subjects with onset age over 70 years. These estimates of the a priori probabilities of dementing disorders have implications for clinicians and researchers.

The Geriatric Mental State Examination in the 21st century

The Geriatric Mental State Examination (GMS) is now established as one of the most commonly used mental health assessments for older people. Its strengths lie in extensive validity studies, high inter-rater reliability, accessibility to trained raters, irrespective of professional background and its continual evolution and adaptation. Its computerisation, association with supplementary instruments and support by a diagnostic algorithm provides a comprehensive diagnostic system and syndrome profile for each subject. The instrument has been validated against most major diagnostic systems and has been used as outcome measures in intervention studies. It has been translated into numerous languages and validated as a diagnostic instrument in various cultures. Such studies have exposed weaknesses, including the over diagnoses of organic states in populations with poorly developed education. On-going studies continue to address these issues, providing a culture sensitive instrument enabling unique trans-cultural research in a relatively under-researched field.

Dementia epidemiology

Determining the incidence and prevalence of dementia is an inexact science. Dementia is difficult to define and detect in the population. Even with the difficulties of determining prevalence and incidence, it is clear that dementia causes a substantial burden on our society. Problems with diagnostic inaccuracy and insidious disease onset influence our ability to observe risk factor associations; factors related to survival may be mistaken for risk/protective factors. Current studies suggest that factors influencing brain development or cognitive reserve may delay the onset of AD, perhaps through a protective mechanism or a delay in diagnosis caused by improved performance on cognitive tests. The recent identification of genes that cause dementia suggests that these genes or their biochemical pathways may be involved in the pathogenesis of nonfamilial cases. The contribution of genes that cause disease in and of themselves may be smaller than that of genes that act to metabolize or potentiate environmental exposures. The interaction between gene and environment should be increasingly well studied in the future. Epidemiology must take advantage of these molecular advances. The tasks of public health and epidemiology should still involve prevention, the nonrandom occurrence of disease, and its environmental context in addition to heredity. The tools to address these tasks should continue to be refined.

Incidence of dementia according to DSM-III-R and ICD-10: results of the Leipzig Longitudinal Study of the Aged (LEILA75+), Part 2

BACKGROUND

The impact of different case definitions on incidence rates remains unclear.

AIMS

To compare incidence rates of dementia according to DSM-III-R and ICD-10.

METHOD

A two-wave community study was conducted (n=1692, age 75+ years follow-up period 1.6 years). Cognitive function was assessed by the Structured Interview for Diagnosis of Dementia of Alzheimer Type, Multiinfarct Dementia and Dementia of other Aetiology according to ICD-10 and DSM-III-R (SIDAM).

RESULTS

The annual incidence rate for dementia by applying different case definitions was found to be quite similar (DSM-III-R: 47.4 (95% CI=36.1-61.2) per 1000 person-years; ICD-10: 45.8 (95% CI=35.0-59.0) per 1000 person-years). Age-specific incidence rates increase steeply with age.

CONCLUSIONS

The impact of different case definitions on incidence rates of dementia appears limited if case definitions and case-finding procedures at baseline and follow-up are applied consistently.

Mild cognitive impairment: clinical features and review of screening instruments

Clinical criteria to recognize subjects with cognitive impairment in the pre-dementia stage are becoming available. These are frail subjects, at risk of adverse outcomes, such as death, institutionalization, and functional and cognitive deterioration. Early identification of these subjects has a great importance in order to start rehabilitative or pharmacological interventions that could slow the progression of cognitive impairment, and the onset of disability. In this regard, cognitive screening tests might be helpful in different clinical settings (general practice, acute care, rehabilitation, and nursing home). We describe the most frequent clinical presentations of cognitive impairment in the pre-dementia stage, and review eleven screening tests to provide recommendations on which should be preferred in each setting.