[Prevention of Alzheimer's dementia in Germany : A projection of the possible potential of reducing selected risk factors]

The impact of hypertension prevention and modification on dementia burden: A systematic review of economic studies

AIM

Neurological disorders account for the largest proportion of disability-adjusted life years globally, with dementia being the third leading cause. Hypertension has been identified as a priority, targetable risk factor for dementia. This study aimed to systematically review economic studies that examine the impact of hypertension prevention and control on the costs and outcomes of dementia.

METHODS

An electronic literature search was conducted using MEDLINE, EMBASE, Scopus, Web of Science, EconLit, and grey literature sources. The inclusion criteria were: 1) economic evaluation studies, including both full and partial evaluations; 2) a primary focus on dementia; and 3) evaluation of the impact of preventing or modifying hypertension on the burden of dementia. The quality of included studies was assessed using the Consensus on Health Economic Criteria (CHEC) list.

RESULTS

Twelve studies were included in the final review. Four studies were full economic evaluations, while eight were partial evaluations, with one reporting costs and seven reporting the impact on dementia prevalence. Nine studies considered hypothetical reductions in hypertension rate, while three evaluated applied hypertension-related interventions. Hypertension modification was associated with higher life expectancy and a higher average age of dementia onset. Full economic evaluations of specific hypertension modification interventions found that these interventions dominated (i.e. had lower costs and higher quality-adjusted life-years (QALY)) the status quo scenario or had an acceptable incremental cost-effectiveness ratio (ICER).

CONCLUSIONS

Hypertension modification has the potential to reduce the burden of dementia in a cost-effective way. However, further economic evaluations of applied interventions are needed to determine real-world feasibility and cost-effectiveness.

Population attributable fractions of modifiable risk factors for dementia: a systematic review and meta-analysis

BACKGROUND

More than 57 million people have dementia worldwide. Evidence indicates a change in dementia prevalence and incidence in high-income countries, which is likely to be due to improved life-course population health. Identifying key modifiable risk factors for dementia is essential for informing risk reduction and prevention strategies. We therefore aimed to estimate the population attributable fraction (PAF) for dementia associated with modifiable risk factors.

METHODS

In this systematic review and meta-analysis, we searched Embase, MEDLINE, and PsycINFO, via Ovid, from database inception up to June 29, 2023, for population-derived or community-based studies and reviews reporting a PAF value for one or more modifiable risk factor for later-life dementia (prevalent or incident dementia in people aged ≥60 years), with no restrictions on dementia subtype, the sex or baseline age of participants, or the period of study. Articles were independently screened for inclusion by four authors, with disagreements resolved through consensus. Data including unweighted and weighted PAF values (weighted to account for communality or overlap in risk) were independently extracted into a predefined template by two authors and checked by two other authors. When five or more unique studies investigated a given risk factor or combination of the same factors, random-effects meta-analyses were used to calculate a pooled PAF percentage estimate for the factor or combination of factors. The review protocol was registered on PROSPERO, CRD42022323429.

FINDINGS

4024 articles were identified, and 74 were included in our narrative synthesis. Overall, PAFs were reported for 61 modifiable risk factors, with sufficient data available for meta-analysis of 12 factors (n=48 studies). In meta-analyses, the highest pooled unweighted PAF values were estimated for low education (17·2% [95% CI 14·4-20·0], p<0·0001), hypertension (15·8% [14·7-17·1], p<0·0001), hearing loss (15·6% [10·3-20·9], p<0·0001), physical inactivity (15·2% [12·8-17·7], p<0·0001), and obesity (9·4% [7·3-11·7], p<0·0001). According to weighted PAF values, low education (9·3% [6·9-11·7], p<0·0001), physical inactivity (7·3% [3·9-11·2], p=0·0021), hearing loss (7·2% [5·2-9·7], p<0·0001), hypertension (7·1% [5·4-8·8], p<0·0001), and obesity (5·3% [3·2-7·4], p=0·0001) had the highest pooled estimates. When low education, midlife hypertension, midlife obesity, smoking, physical inactivity, depression, and diabetes were combined (Barnes and Yaffe seven-factor model; n=9 studies), the pooled unweighted and weighted PAF values were 55·0% (46·5-63·5; p<0·0001) and 32·0% (26·6-37·5; p<0·0001), respectively. The pooled PAF values for most individual risk factors were higher in low-income and middle-income countries (LMICs) versus high-income countries.

INTERPRETATION

Governments need to invest in a life-course approach to dementia prevention, including policies that enable quality education, health-promoting environments, and improved health. This investment is particularly important in LMICs, where the potential for prevention is high, but resources, infrastructure, budgets, and research focused on ageing and dementia are limited.

FUNDING

UK Research and Innovation (Medical Research Council).

Associations of Depressive Symptoms with Subjective Cognitive Decline in Elderly People-A Cross-Sectional Analysis from the AgeWell.de-Study

To develop effective dementia prevention strategies, it is necessary to understand risk factors, associated factors and early signs of dementia. Subjective cognitive decline (SCD) is the earliest form of dementia. The aim of this study is to assess depression as a factor that is significantly associated with SCD. The data of 1030 general practitioner patients from the AgeWell.de-study (60-77 years; CAIDE dementia risk score ≥ 9) were analysed. A descriptive analysis was conducted using validated instruments like the Geriatric depression scale (GDS), Lubben social network scale (LSNS-6) and education classes according to CASMIN (Comparative Analysis of Social Mobility in Industrial Nations). A multivariate regression model with the dependent variable SCD was calculated. Of the 1030 participants, 5.9% had depressive symptoms and 31.3% SCD. The group with depressive symptoms showed significantly higher body-mass-index (p = 0.005), lower education class (p = 0.022), lower LSNS-6 score (p < 0.001), higher sports activity (p < 0.001), and more sleeping problems (p = 0.026). In the regression model a higher GDS-score [Odds ratio (OR): 1.219 (p < 0.001)], more sleeping problems [OR: 1.550 (p = 0.017)] and higher education class [middle/high: OR: 1.474/1.875 (p = 0.037/0.004)] were significantly associated with SCD. This study identified depressive symptoms, sleeping problems, and higher education classes as factors associated with SCD, which can represent an early form of dementia.

Dementia in Germany: Epidemiology and Prevention Potential

BACKGROUND

The further development of public-health approaches for the prevention of dementia requires estimates of the number of people with dementia, trends in incidence and prevalence, and the potential impact of preventive measures.

METHODS

The projections described here are based on incidence and prevalence data for Europe and on current and projected population figures from the German Federal Statistical Office. Four scenarios were calculated on the basis of two different population projections and the assumption of either stable or declining prevalence. Data from the German Aging Survey were used to estimate the prevention potential for eleven potentially modifiable risk factors for dementia. Weighting factors were determined to adjust for correlations between risk factors.

RESULTS

Approximately 1.8 million people were living with dementia in Germany as of December 31, 2021; the number of new dementia cases in 2021 is estimated at 360 000 to 440 000. In 2033, depending on the scenario, 1.65 to 2 million people aged 65 and older may be affected; we consider likelihood of the lower end of this range to be very low. It is estimated that 38% of these cases are associated with 11 potentially modifiable risk factors. A 15% reduction in the prevalence of risk factors could potentially decrease the number of cases by up to 138 000 in 2033.

CONCLUSION

We assume that the number of people with dementia in Germany will increase, but there is considerable prevention potential. Multimodal prevention approaches to promote healthy aging should be further developed and put into practice. Better data are needed on incidence and prevalence of dementia in Germany.

[Brain health services: individual dementia risk profiling at the Cologne Alzheimer Prevention Center]

BACKGROUND

According to current knowledge approximately 30-40% of all cases of dementia can be attributed to modifiable risk factors. As a result, dementia prevention and the concept of brain health are becoming increasingly relevant.

RESEARCH QUESTION

The requirements for brain health services and their implementation are discussed and the Cologne Alzheimer Prevention Center (KAP) of the University Hospital Cologne is described as an example.

MATERIAL AND METHODS

In addition to a report on international brain health initiatives, the main activities of the KAP are presented. A program for individual risk profiling and risk communication is provided, which was piloted in the KAP in the context of the "Individual risk profiling for Alzheimer's disease and dementia prevention (INSPIRATION)" study. The prevalence of risk factors in a cognitively healthy sample aged 50-86 years (n = 162) with interest in dementia prevention is presented.

RESULTS

The most common risk factors were non-Mediterranean diet, obesity, subjective poor sleep quality and increased stress. Based on these results, preventive interventions can be developed that are adapted to the individual risk profile as a personalized medicine approach.

DISCUSSION

Structures such as the KAP can provide individual risk factor assessment and personalized dementia prevention. The efficacy of this approach on dementia risk reduction needs to be evaluated.

Interdisciplinary Approaches to Deal with Alzheimer's Disease-From Bench to Bedside: What Feasible Options Do Already Exist Today?

Alzheimer's disease is one of the most common neurodegenerative diseases in the western population. The incidence of this disease increases with age. Rising life expectancy and the resulting increase in the ratio of elderly in the population are likely to exacerbate socioeconomic problems. Alzheimer's disease is a multifactorial disease. In addition to amyloidogenic processing leading to plaques, and tau pathology, but also other molecular causes such as oxidative stress or inflammation play a crucial role. We summarize the molecular mechanisms leading to Alzheimer's disease and which potential interventions are known to interfere with these mechanisms, focusing on nutritional approaches and physical activity but also the beneficial effects of cognition-oriented treatments with a focus on language and communication. Interestingly, recent findings also suggest a causal link between oral conditions, such as periodontitis or edentulism, and Alzheimer's disease, raising the question of whether dental intervention in Alzheimer's patients can be beneficial as well. Unfortunately, all previous single-domain interventions have been shown to have limited benefit to patients. However, the latest studies indicate that combining these efforts into multidomain approaches may have increased preventive or therapeutic potential. Therefore, as another emphasis in this review, we provide an overview of current literature dealing with studies combining the above-mentioned approaches and discuss potential advantages compared to monotherapies. Considering current literature and intervention options, we also propose a multidomain interdisciplinary approach for the treatment of Alzheimer's disease patients that synergistically links the individual approaches. In conclusion, this review highlights the need to combine different approaches in an interdisciplinary manner, to address the future challenges of Alzheimer's disease.

[Dementia prevention and primary care: Estimation of the target population]

BACKGROUND

The prevention of dementia, especially the cardiovascular prevention of cognitive disorders, is increasingly coming into the focus of health services research. The aim of this study is to determine the possible target population for dementia prevention approaches as well as frequency of health examinations (HE) in individual general practitioner offices (GP).

METHOD

987 GP practices, which are covered by the nationwide IMS Disease Analyzer database (IQVIA) have been investigated for the prevalence of the following diagnoses, which are considered risk factors for the development of dementia Hypertension, obesity, hearing loss in each age group 45-65 and diabetes and depression in the age group 65 and older. In addition, it was recorded how many of these patients received a HE).

RESULTS

In a sample of 2,398,405 patients receiving primary care, the target population relevant for dementia prevention measures in 2018 consisted of 191,883 patients with hypertension, 23,308 with obesity, 5,059 with hearing loss, 120,200 with diabetes and 43,233 with depression. More than a quarter of these patients have already had a HE. In 2018, patients with hypertension (N=51), diabetes (N=30.5) and depression (N=11.3) were the most frequently treated patients, less frequently patients with obesity (N=8.2) and hearing loss (N=1.6).

CONCLUSION

On the basis of defined diagnoses in certain phases of life, a manageable group of patients can be identified who are eligible for specific dementia preventive interventions. The implementation of dementia preventive interventions in practices will be more difficult for the less frequent treatment diagnoses obesity and hearing loss than for the much more frequent treatment diagnoses hypertension, diabetes and depression.

Association between sedentary behavior and the risk of dementia: a systematic review and meta-analysis

An increasing number of original studies suggest that sedentary behavior is associated with the risk of dementia, but the results remain inconsistent and inconclusive. In this meta-analysis, we analyzed available observational epidemiological evidence to identify the association between sedentary behavior and the risk of dementia. We searched PubMed and Embase from their inception to March 2019 to identify observational studies examining the association between sedentary behavior and risk of dementia. Two authors independently extracted data and assessed study quality using predefined criteria. The Q statistics and I² methods were used to test for heterogeneity. The publication bias of the included studies was also estimated using Begg's and Egger's tests. We identified 18 relevant cohort studies involving 250,063 participants and 2269 patients with dementia. Pooled result showed that sedentary behavior was significantly associated with increased risk of dementia (RR = 1.30; 95% CI: 1.12-1.51). In addition, subgroup analyses by state, and controlling for the concomitant effects of age, sex, education were conducted for the increase of dementia risk, relating to sedentary, respectively. In general, these subgroup analyses showed no statistically significant differences. The results of our meta-analysis suggested that sedentary behavior was independently associated with a significantly increased risk of dementia, which might have important implications in conducting etiological studies for dementia and developing strategies for dementia prevention.

Lifestyle Modifications and Nutritional Interventions in Aging-Associated Cognitive Decline and Alzheimer's Disease

Alzheimer's disease (AD) is a type of incurable neurodegenerative disease that is characterized by the accumulation of amyloid-β (Aβ; plaques) and tau hyperphosphorylation as neurofibrillary tangles (NFTs) in the brain followed by neuronal death, cognitive decline, and memory loss. The high prevalence of AD in the developed world has become a major public health challenge associated with social and economic burdens on individuals and society. Due to there being limited options for early diagnosis and determining the exact pathophysiology of AD, finding effective therapeutic strategies has become a great challenge. Several possible risk factors associated with AD pathology have been identified; however, their roles are still inconclusive. Recent clinical trials of the drugs targeting Aβ and tau have failed to find a cure for the AD pathology. Therefore, effective preventive strategies should be followed to reduce the exponential increase in the prevalence of cognitive decline and dementia, especially AD. Although the search for new therapeutic targets is a great challenge for the scientific community, the roles of lifestyle interventions and nutraceuticals in the prevention of many metabolic and neurodegenerative diseases are highly appreciated in the literature. In this article, we summarize the molecular mechanisms involved in AD pathology and the possible ameliorative action of lifestyle and nutritional interventions including diet, exercise, Calorie restriction (CR), and various bioactive compounds on cognitive decline and dementia. This article will provide insights into the role of non-pharmacologic interventions in the modulation of AD pathology, which may offer the benefit of improving quality of life by reducing cognitive decline and incident AD.

AgeWell.de - study protocol of a pragmatic multi-center cluster-randomized controlled prevention trial against cognitive decline in older primary care patients

BACKGROUND

In the absence of treatment options, the WHO emphasizes the identification of effective prevention strategies as a key element to counteract the dementia epidemic. Regarding the complex nature of dementia, trials simultaneously targeting multiple risk factors should be particularly effective for prevention. So far, however, only few such multi-component trials have been launched, but yielding promising results. In Germany, comparable initiatives are lacking, and translation of these complex interventions into routine care was not yet done. Therefore, AgeWell.de will be conducted as the first multi-component prevention trial in Germany which is closely linked to the primary care setting.

METHODS

AgeWell.de will be designed as a multi-centric, cluster-randomized controlled multi-component prevention trial. Participants will be older community-dwelling general practitioner (GP) patients (60-77 years; n = 1,152) with increased dementia risk according to CAIDE (Cardiovascular Risk Factors, Aging, and Incidence of Dementia) Dementia Risk Score. Recruitment will take place at 5 study sites across Germany. GP practices will be randomized to either intervention A (advanced) or B (basic). GPs will be blinded to their respective group assignment, as will be the statistician conducting the randomization. The multi-component intervention (A) includes nutritional counseling, physical activity, cognitive training, optimization of medication, management of vascular risk factors, social activity, and, if necessary, further specific interventions targeting grief and depression. Intervention B includes general health advice on the intervention components and GP treatment as usual. We hypothesize that over the 2-year follow-up period the intervention group A will benefit significantly from the intervention program in terms of preserved cognitive function/delayed cognitive decline (primary outcome), and other relevant (secondary) outcomes (e.g. quality of life, social activities, depressive symptomatology, cost-effectiveness).

DISCUSSION

AgeWell.de will be the first multi-component trial targeting risk of cognitive decline in older adults in Germany. Compared to previous trials, AgeWell.de covers an even broader set of interventions suggested to be beneficial for the intended outcomes. The findings will add substantial knowledge on modifiable lifestyle factors to prevent or delay cognitive decline.

TRIAL REGISTRATION

German Clinical Trials Register (reference number: DRKS00013555 ).

Primary prevention of dementia: from modifiable risk factors to a public brain health agenda?

INTRODUCTION

With large numbers of people affected, no treatment in sight and continuing demographic change, the prevention of dementia is becoming a central public health issue.

METHODS

We conducted a systematic meta-review including systematic reviews and meta-analyses of longitudinal observational studies on modifiable risk and protective factors for dementia published over the last 5 years.

RESULTS

Compelling evidence on a number of modifiable risk factors, mostly lifestyle factors, is available from longitudinal observational studies to inform primary preventive efforts.

DISCUSSION

Evidence stemming from preventive RCTs is limited. However, multi-domain interventions addressing a variety of risk factors at once seem promising with regard to high-risk individuals (selective preventive approach). However, we argue that it is time to move forward and discuss a public brain health agenda as a universal preventive approach. Based on a risk reduction strategy, the public brain health agenda suggests the following ten key actions: (1) increase physical activity, (2) foster social integration, (3) improve education and foster lifelong learning, (4) provide mentally stimulating workplaces, (5) foster a cognitively active lifestyle, (6) propose a healthy Mediterranean-like diet, (7) reduce alcohol consumption, (8) stop smoking, (9) prevent, diagnose and treat chronic conditions, and (10) reduce anticholinergic medication in the elderly.

[Prevalence of dementia of insured persons with and without German citizenship : A study based on statuatory health insurance data]

BACKGROUND

Elderly people with a non-German background are a fast growing population in Germany.

OBJECTIVES

Is administrative prevalence of dementia and uptake of nursing-home care similar in the German and non-German insured?

MATERIALS AND METHODS

Based on routine data, administrative prevalence rates for dementia were calculated for 2013 from a full census of data from one large sickness fund. Patients with dementia (PWD) were identified via ICD-10 codes (F00; F01; F03; F05; G30).

RESULTS

Administrative prevalence of dementia was 2.67% in the study population; 3.06% in Germans, and 0.96% in non-Germans (p value <0.001). Age and sex adjusted prevalence was comparable in the insured with and without German citizenship, except in women aged 80-84 (17.2 vs. 15.4) and for men in the age groups 80-84 (16.5 vs. 14.2), 85-89 years (23.4 vs. 21.5), and above 90 years of age (32.3 vs. 26.3). Standardized to the population of all investigated insured, 31.4% of all Germans with dementia had no longterm care entitlement vs. 35.5% of all patients without German citizenship. Of German patients, 55.1% were institutionalized vs. 39.5% of all patients without German citizenship.

CONCLUSIONS

There was a higher prevalence of dementia in the very old insured without German citizenship compared to those with German citizenship, especially in men. Non-Germans showed lower uptake of nursing home care compared to Germans. Additionally, Germans had slightly higher nursing care entitlements. It should be investigated further how much of the difference is due to underdiagnosis, cultural differences, or lack of adequate diagnostic work-up.

An Estimate of Attributable Cases of Alzheimer Disease and Vascular Dementia due to Modifiable Risk Factors: The Impact of Primary Prevention in Europe and in Italy

BACKGROUND

Up to 53.7% of all cases of dementia are assumed to be due to Alzheimer disease (AD), while 15.8% are considered to be due to vascular dementia (VaD). In Europe, about 3 million cases of AD could be due to 7 potentially modifiable risk factors: diabetes, midlife hypertension and/or obesity, physical inactivity, depression, smoking, and low educational level.

AIMS

To estimate the number of VaD cases in Europe and the number of AD and VaD cases in Italy attributable to these 7 potentially modifiable risk factors.

METHODS

Assuming the nonindependence of the 7 risk factors, the adjusted combined population attributable risk (PAR) was estimated for AD and VaD.

RESULTS

In Europe, adjusted combined PAR was 31.4% for AD and 37.8% for VaD. The total number of attributable cases was 3,033,000 for AD and 873,000 for VaD. In Italy, assuming a 20% reduction of the prevalence of each risk factor, adjusted combined PAR decreased from 45.2 to 38.9% for AD and from 53.1 to 46.6% for VaD, implying a 6.4 and 6.5% reduction in the prevalence of AD and VaD, respectively.

CONCLUSION

A relevant reduction of AD and VaD cases in Europe and Italy could be obtained through primary prevention.