Dementia syndrome and Alzheimer disease: an assessment of morbidity and annual incidence in Germany

Due to the increasing life expectancy and the growing number of elderly people, dementia is emerging as a major health problem. There is, however, a lack of consistent data on the number of prevalent and incident cases of dementia in Germany. The aim of the present study was to estimate the prevalence and the incidence of dementing disorders in general as well as Alzheimer's disease in particular on the basis of disease rates based on large-scale epidemiological field studies and meta-analyses, which were standardized according to the age structure of the German population. The results show that probably more than 900,000 persons in Germany suffer from a dementing illness, 650,000 among them from Alzheimer's disease. About 200,000 new cases of dementia develop during one year, among them 120,000 new cases of Alzheimer's disease. Due to the higher life expectancy of women as compared to men 70% of the patients are of female gender. As a consequence of the steep increase of disease rates with age, two-thirds of the prevalent cases and 60% of the incident cases are found among people in the age bracket of 80 and over, whereas only 3% are found among persons younger than 65 years of age. Additionally, an estimate of the distribution of cases by the 16 Federal states of Germany is given.     

Dementing Illnesses in Rural Populations: The Need for Research and Challenges Confronting Investigators

Expansion of the world's elderly populations has increased concerns about aging-related medical disorders like Alzheimer's disease and other dementias. In the United States, one fourth of those older than age 65 and at greatest risk for developing dementia live in rural environments that may influence its manifestation. The objectives of this study were to determine the need for and potential benefits of further epidemiological research concerning dementia and similar disorders in rural U.S. populations and to identify pertinent methodological issues related to rural dementia research. This study employed a National Library of Medicine (MEDLINE) document search based on the key words "cognitive disorders," "dementia," "Alzheimer's disease," and "rural," followed by recovery of literature resources references in the bibliographies of selected articles. Nineteen studies focusing on dementia or related disorders in rural settings have been reported from around the world. While four of these were conducted in the United States, only one rural dementia prevalence study has been undertaken in this country. Because of methodological variability, comparisons of prevalence estimates between these rural studies, as well as with those from urban investigations, is difficult. Nonetheless, there is reason to believe that certain potentially dementing illnesses are more common in rural populations. There is also evidence to suggest that the screening instruments commonly used in such studies tend to misclassify rural elders as "false positive" dementia cases. Information regarding dementing disorders, particularly Alzheimer's disease, in rural populations is scarce. Preliminary observations that dementia may be more common in rural settings and that rural families are more likely to maintain their dementing elders in the community imply that further rural dementia research could yield important insights into the risk factors for these illnesses, the variables influencing their course, and the methods by which they can be more effectively managed. A determination of the reliability and validity of commonly used dementia screening instruments in rural populations would represent an important advancement in this area of research.     

Brain aging: lessons from community studies

Dementia is an acquired highly disabling syndrome common among elderly people. Alzheimer's disease is the most frequent type of dementia, and its prevalence is rapidly increasing due to the aging of populations. Therefore, the need to find effective preventive means is pressing. Population studies allow identification of risk/protective factors for dementia/Alzheimer's disease, thus leading to preventive strategies that can be implemented in the general population to reduce the incidence of this disorder. Presented here is an overview of the main findings of epidemiological studies on nutritional factors and nutrition-related pathological conditions, as related to dementia and Alzheimer's disease.     

Mortality from dementia in Norway, 1969-83.

From 1969 to the end of 1983 in Norway, dementia was coded as the underlying cause of death from 2058 death certificates, and as a contributory cause from 19,459. This is 3.56% of the total number of deaths. It seems that a considerable proportion of dementia cases are noted on death certificates in Norway. Death rates based on dementia as the underlying cause of death have increased with time, but when including contributory causes, rates have declined. The data may be useful in epidemiological studies, eg, to search for aetiological clues for Alzheimer's disease. Due to the inclusion of contributory causes of death in the registers and to the high number of dementia cases noted on death certificates, Norwegian mortality data on dementia are probably of better quality than in most other countries.     

Risk factors associated with senile dementia of the Alzheimer's type

Significant cognitive impairment affects approximately 15 percent of the U.S. population over age 65. The most prevalent form of irreversible dementia is senile dementia of the Alzheimer's type (SDAT), which accounts for at least 50 percent of nursing home admissions and roughly 10 billion dollars a year in health care costs. In spite of the social, economic, and medical impact of the disease, epidemiological data are scarce concerning risk factors associated with the disease. Until recently, most of the population-based studies of senile dementia in the elderly were carried out in Northern European countries. The methodological problems that arise in performing epidemiologic studies on SDAT may in part explain the lack of sufficient data pertaining to certain risk factors. This paper provides a review of the literature and research on risk factors in dementia in the elderly and discusses directions for future research. The epidemiological issues associated with certain key studies are also discussed. Although the major studies that have attempted to look at risk factors in mental illness in the elderly are beginning to fill in some of the gaps in the understanding of the etiology and epidemiology of the disease, further epidemiologic studies on both institutionalized and community-based elderly populations are needed. These should assess a wide range of possible factors (demographic, psychological, environmental, health practice, and medical) in terms of their association with SDAT. By developing a comprehensive epidemiologic profile of SDAT, possible preventive measures and therapeutic approaches to treating the disease may be identified and hypotheses for future epidemiological and laboratory investigations developed.     

An illness-death stochastic model in the analysis of longitudinal dementia data

A significant source of missing data in longitudinal epidemiological studies on elderly individuals is death. Subjects in large scale community-based longitudinal dementia studies are usually evaluated for disease status in study waves, not under continuous surveillance as in traditional cohort studies. Therefore, for the deceased subjects, disease status prior to death cannot be ascertained. Statistical methods assuming deceased subjects to be missing at random may not be realistic in dementia studies and may lead to biased results. We propose a stochastic model approach to simultaneously estimate disease incidence and mortality rates. We set up a Markov chain model consisting of three states, non-diseased, diseased and dead, and estimate the transition hazard parameters using the maximum likelihood approach. Simulation results are presented indicating adequate performance of the proposed approach.     

Death certification after a diagnosis of presenile dementia.

STUDY OBJECTIVES--To assess the value of death certification for the epidemiological study of dementia, the frequency with which the condition was recorded on death certificates of patients diagnosed with some form of dementia before the age of 65 years was studied. A further objective was to identify variables associated with failure to record dementia on the certificate. DESIGN--A cohort of patients with presenile dementia, differentiated by a clinical algorithm applied to hospital case records, was traced through the National Health Service Central Registry and details of certified causes of death were obtained. SETTING--The Northern Regional Health Authority in England. SUBJECTS--Prevalent cases of presenile dementia resident in the northern health region during 1986 traced up to April 1992. MEASUREMENTS AND MAIN RESULTS--The underlying cause of death was recorded as dementia or as Alzheimer's disease in 53% of cases of clinically diagnosed presenile Alzheimer's disease, 33% of cases of presenile vascular dementia, and 10% of cases of presenile dementia secondary to another neurological condition. Dementia or Alzheimer's disease was recorded in any part of the certificate in 75% of cases of Alzheimer's disease, 52% of vascular dementia, 33% of other dementias, and in 65% of cases overall. Dementia or a cerebral condition of a kind that can result in dementia was recorded in 80% of all cases. Failure to mention dementia was related to the clinical type of dementia, shorter duration of illness, and earlier period of study. CONCLUSIONS--The underlying cause of death seriously understates the frequency of dementia, but when the recording of other brain disease is taken into account the presence of potentially dementing brain disease is recorded much more frequently. It is suggested that coding chronic conditions present at death, such as dementia, in addition to those causing or contributing to death would improve the value of death certificates for epidemiological purposes.     

Prevalence of anemia and deficiency of iron, folic acid, and zinc in children younger than 2 years of age who use the health services provided by the Mexican Social Security Institute

Background

Latin America, China and India are experiencing unprecedentedly rapid demographic ageing with an increasing number of people with dementia. The 10/66 Dementia Research Group's title refers to the 66% of people with dementia that live in developing countries and the less than one tenth of population-based research carried out in those settings. This paper describes the protocols for the 10/66 population-based and intervention studies that aim to redress this imbalance.

Methods/design

Cross-sectional comprehensive one phase surveys have been conducted of all residents aged 65 and over of geographically defined catchment areas in ten low and middle income countries (India, China, Nigeria, Cuba, Dominican Republic, Brazil, Venezuela, Mexico, Peru and Argentina), with a sample size of between 1000 and 3000 (generally 2000). Each of the studies uses the same core minimum data set with cross-culturally validated assessments (dementia diagnosis and subtypes, mental disorders, physical health, anthropometry, demographics, extensive non communicable disease risk factor questionnaires, disability/functioning, health service utilisation, care arrangements and caregiver strain). Nested within the population based studies is a randomised controlled trial of a caregiver intervention for people with dementia and their families (ISRCTN41039907; ISRCTN41062011; ISRCTN95135433; ISRCTN66355402; ISRCTN93378627; ISRCTN94921815). A follow up of 2.5 to 3.5 years will be conducted in 7 countries (China, Cuba, Dominican Republic, Venezuela, Mexico, Peru and Argentina) to assess risk factors for incident dementia, stroke and all cause and cause-specific mortality; verbal autopsy will be used to identify causes of death.

Discussion

The 10/66 DRG baseline population-based studies are nearly complete. The incidence phase will be completed in 2009. All investigators are committed to establish an anonymised file sharing archive with monitored public access. Our aim is to create an evidence base to empower advocacy, raise awareness about dementia, and ensure that the health and social care needs of older people are anticipated and met.     

Epidemiological research on dementia in developing countries

As the world population is ageing, dementia becomes an important public health problem, particularly in developing countries. Epidemiological research in these settings is scarce and present additional methodological difficulties, mainly regarding the socio-cultural adequacy of instruments used to identify cases of dementia. As a result of these concerns the 10/66 Dementia Research Group was founded to fill this gap. This is an international network of investigators, mostly from developing countries, and the group's name was based on the paradox that less than 10% of the population-based studies on dementia are directed to 2/3 or more cases of people with dementia living in developing countries. The aim of the paper is to update data in the literature regarding the differences in dementia prevalence and incidence seen in developed and developing countries.     

Getting lost with dementia: Encounters with the time-space of not knowing

In this paper we explore the experience and implications of getting lost with dementia. While getting lost has become culturally emblematic of dementia, speaking as it does to a widespread fear of losing our place in the world, it is marked by an overall absence of critical attention. We argue that this critical hesitancy is part of a broader unease with ‘dementing’ that reveals a paradox in dementia scholarship as growing emphasis on strengths-based and capacity-oriented approaches to the condition shift attention away from episodes of disorientation, forgetting and unknowing that commonly arise after onset. We therefore explore getting lost with dementia, not only as a route to better understanding what happens during such events and the meaning it holds but also to consider the implications for a broader politics of the social inclusion of people living with dementia. Reporting findings from a five-year international study of the neighbourhood experiences of people with dementia, we suggest that through such experiences as getting lost, people with dementia have a unique and distinctive contribution to make to the ever-evolving character of public space and civic culture. In particular, we argue that getting lost and the subsequent recovery or reconstitution that ensues can help inform efforts to reimagine public space. This includes looking beyond risk reduction in responses to dementia and public and outdoor settings to consider how freedom of movement for people with dementia might be enhanced rather than curtailed. Our learning points to the value of making the process of dementing more visible and central to the politics and practices of social inclusion.     

Mortality from dementia in advanced age: a 5-year follow-up study of incident dementia cases.

Five-year follow-up of a community-based, 77+ old cohort including incident dementia cases was used to evaluate the impact of dementia on the risk of death, taking into account other chronic conditions potentially related to death, and contrasting Alzheimer's disease (AD), and vascular dementia (VaD). In this population, 70% of the dementia cases died during the five years after diagnosis, with a mortality rate specific for dementia of 2.4 per 100 person-years. After controlling for sociodemographic variables and comorbidity, 14% of all deaths could be attributed to dementia with a risk of death among demented subjects twice as high as that for non-demented people. Mortality risk ratios were 2.0 (95% confidence interval 1.5-2.7) for AD and 3.3 (95% confidence interval 2.0-5.3) for VaD. This study confirms that dementing disorders are a major risk factor for death. Even in the oldest old (85+), dementia shortens life, especially among women.     

陕西省西安地区中老年人痴呆及其主要亚型发病率调查

目的 了解西安地区中老年人痴呆及其主要亚型的发病率,分析痴呆及其主要亚型的危险因素。方法 对1998年完成痴呆患病率调查的2919名西安地区居民进行随访,以简易智能量表(MMSE)作为筛查工具,应用三阶段诊断法确诊痴呆及其亚型。根据随访的人年数计算痴呆、Alzheimer病(AD)及血管性痴呆(VD)的年发病率。痴呆诊断按照美国精神疾病诊断、统计手册第三版(修订版)(DSM-Ⅲ-R)的标准,AD诊断按照美国国立神经疾病、语言交流障碍和卒中一老年性痴呆及相关疾病学会(NINCDS-ADRDA)的标准,VD诊断按照美国国立神经疾病和卒中研究所和瑞士国际神经科学研究协会(NINDSAIREN)标准的。结果 实际随访到2197人,平均随访3．2年,共计6886．43人年。新诊断痴呆47例,其中AD 37例,VD 8例,其他原因引起的痴呆2例。55岁以上人群痴呆及AD、VD年发病率分别为0．68％、0．54％、0．12％;65岁以上人群痴呆及AD、VD年发病率分别为0．89％、0．69％、0．17％。单因素分析和多因素logistic回归分析显示,AD发病率与年龄、文化程度密切相关;而VD发病率与年龄、卒中史和高血压密切相关。结论 高龄、低文化程度是AD的危险因素,而年龄、高血压和卒中是VD的危险因素。     

Epidemiology of epilepsy--recent achievements and future

Epilepsy is a very common neurological disease. Reliable epidemiological data are of great importance for understanding the etiology and risk factors for its development. It is necessary to use standardized methodology for the results from epilepsy studies in different geographical regions to be comparable. Most of the epidemiological studies of epilepsy find an incidence rate of 20-70/100,000 per year (range 11-134/100,000). The state of the problem in Bulgaria and other countries of Eastern Europe is not adequately studied. It is considered that the figures are higher in the developing countries. Incidence is higher in men than in women and varies considerably with age--it is high in childhood, decreases in young people and rises again in the elderly. Only approximately 30% of the newly-registered cases can be assigned to one of the diagnostic categories. The studies identify an etiological factor in only about one third of all cases. The most commonly reported etiological factors are: cerebro-vascular disease, tumors, alcohol, head injuries, congenital factors and neuroinfections. Most of the developed countries report prevalence of active epilepsy in the range of 4-8/1000. The prevalence rates in Latin America and some African states are especially high. In Bulgaria by means of the system of regional psychoneurological dispensaries about 30,000 epilepsy patients are registered, but it may be assumed that their real number is over 60,000. Contemporary views on the prognosis of this disease are favorable--more than 70% of the diseased reach long-term remission. Different prognostic factors predicting the final outcome of epilepsy patients are described. Epilepsy patients exhibit more than 2 times higher mortality rate than the expected rate for the corresponding population. It is necessary to conduct additional projects, based on the available standardized methodology for epidemiological monitoring of epilepsy in different geographical regions, including Bulgaria.     

老年痴呆: 威胁所有的老年人

中国老年痴呆症患者数2015年已>1 000万,为所有发达国家发病数的总和,老年痴呆已成为我国十分严峻的社会和公共卫生问题;目前认知损伤和痴呆类的疾病缺少行之有效的治疗方法,因此研究其危险因素成为了疾病预防的关键。近年来随着我国工业经济的快速发展,空气污染已成为主要的公共卫生问题,有研究表明空气污染物对老年人认知功能损伤及痴呆具有一定影响,为此本文就常见空气污染物与老年人认知损伤及痴呆的关系进行综述,旨在为降低老年人认知功能损伤及痴呆的发病率提供新的思路。     

Oxidative Damage,Antioxidants and Stroke

Nutritional factors may have an important role to play in incidence and treatment of stroke. Many epidemiological studies report that people who eat a relatively large quantity of fruits, vegetables and grains have a lower risk of death, particularly from cardiovascular disease. Some of these studies consistently revealed an association between increased risk of stroke and low plasma concentrations of antioxidants. There is also strong indirect evidence that free radical production appears to be an important mechanism of brain injury after exposure to ischaemia and reperfusion. The role of free radical formation in the pathogenesis of ischaemic brain damage and the neuroprotective effect of antioxidants are not definitely established and need further studies.     

Cross-national comparability of burden of disease estimates: the European Disability Weights Project

OBJECTIVE: To investigate the sources of cross-national variation in disability-adjusted life-years (DALYs) in the European Disability Weights Project. METHODS: Disability weights for 15 disease stages were derived empirically in five countries by means of a standardized procedure and the cross-national differences in visual analogue scale (VAS) scores were analysed. For each country the burden of dementia in women, used as an illustrative example, was estimated in DALYs. An analysis was performed of the relative effects of cross-national variations in demography, epidemiology and disability weights on DALY estimates. FINDINGS: Cross-national comparison of VAS scores showed almost identical ranking orders. After standardization for population size and age structure of the populations, the DALY rates per 100000 women ranged from 1050 in France to 1404 in the Netherlands. Because of uncertainties in the epidemiological data, the extent to which these differences reflected true variation between countries was difficult to estimate. The use of European rather than country-specific disability weights did not lead to a significant change in the burden of disease estimates for dementia. CONCLUSIONS: Sound epidemiological data are the first requirement for burden of disease estimation and relevant between-countries comparisons. DALY estimates for dementia were relatively insensitive to differences in disability weights between European countries.     

Managing Images of Occupational Self in Early Stage Dementia

The purpose of this qualitative study was to enhance our understanding of the experience of living with an early stage dementing disease and its occupational consequences. Data were collected through interviews with and observations of two participants and analyzed using a comparative and interpretative approach. From an occupational perspective the findings demonstrated considerable differences in consequences of dementia between the two participants. The participants' images of an “occupational self” provided a means for us to understand these differences. The study suggests the use of a meaning-searching approach for understanding the significance of a dementing disease and its consequences on the affected individual's occupational life.     

Egg Consumption and Human Cardio-Metabolic Health in People with and without Diabetes

The guidelines for dietary cholesterol and/or egg intake for both the general population and those at higher risk of cardiovascular disease (for example, people with type 2 diabetes mellitus (T2DM)) differ between countries, and even for different specialist societies in a country. The disparity between these guidelines is at least in part related to the conflicting evidence as to the effects of eggs in the general population and in those with T2DM. This review addresses the effect of eggs on cardiovascular disease (CVD) risk from both epidemiological research and controlled prospective studies, in people with and without cardio-metabolic disease. It also examines the nutritional qualities of eggs and whether they may offer protection against chronic disease. The evidence suggests that a diet including more eggs than is recommended (at least in some countries) may be used safely as part of a healthy diet in both the general population and for those at high risk of cardiovascular disease, those with established coronary heart disease, and those with T2DM. In conclusion, an approach focused on a person’s entire dietary intake as opposed to specific foods or nutrients should be the heart of population nutrition guidelines.     

Trends in the incidence of dementia: design and methods in the Alzheimer Cohorts Consortium

Several studies have reported a decline in incidence of dementia which may have large implications for the projected burden of disease, and provide important guidance to preventive efforts. However, reports are conflicting or inconclusive with regard to the impact of gender and education with underlying causes of a presumed declining trend remaining largely unidentified. The Alzheimer Cohorts Consortium aggregates data from nine international population-based cohorts to determine changes in the incidence of dementia since 1990. We will employ Poisson regression models to calculate incidence rates in each cohort and Cox proportional hazard regression to compare 5-year cumulative hazards across study-specific epochs. Finally, we will meta-analyse changes per decade across cohorts, and repeat all analysis stratified by sex, education and APOE genotype. In all cohorts combined, there are data on almost 69,000 people at risk of dementia with the range of follow-up years between 2 and 27. The average age at baseline is similar across cohorts ranging between 72 and 77. Uniting a wide range of disease-specific and methodological expertise in research teams, the first analyses within the Alzheimer Cohorts Consortium are underway to tackle outstanding challenges in the assessment of time-trends in dementia occurrence.     

Risk factors for vascular dementia: hypotension as a key point

Physiologically, the cerebral autoregulation system allows maintenance of constant cerebral blood flow over a wide range of blood pressure. In old people, there is a progressive reshape of cerebral autoregulation from a sigmoid curve to a straight line. This implies that any abrupt change in blood pressure will result in a rapid and significant change in cerebral blood flow. Hypertension has often been observed to be a risk factor for vascular dementia (VaD) and sometimes for Alzheimer disease although not always. Indeed, high blood pressure may accelerate cerebral white matter lesions, but white matter lesions have been found to be facilitated by excessive fall in blood pressure, including orthostatic dysregulation and postprandial hypotension. Many recent studies observed among other data, that there was a correlation between systolic pressure reduction and cognitive decline in women, which was not accounted for by other factors. Baseline blood pressure level was not significantly related to cognitive decline with initial good cognition. Some researchers speculate that blood pressure reduction might be an early change of the dementing process. The most confounding factor is that low pressure by itself might be a predictor of death; nevertheless, the effect of low blood pressure on cognition is underestimated because of a survival bias. Another explanation is that clinically unrecognized vascular lesions in the brain or atherosclerosis are responsible for both cognitive decline and blood pressure reduction. We discuss the entire process, and try to define a possible mechanism that is able to explain the dynamic by which hypotension might be related to dementia.