Incidence of Dementia and Associated Factors in the EPIC-Spain Dementia Cohort

Cost of Patients with Alzheimer's Disease in Spain According to Disease Severity

BACKGROUND

Alzheimer's disease (AD) has been associated with great healthcare and non-healthcare resource consumption. The aim of this study was to estimate the burden of AD in Spain according to disease severity from a societal perspective.

METHODS

A self-administered questionnaire was designed by the researchers and completed by the informal caregivers of patients with AD, reporting data on themselves as caregivers and on the AD patients for whom they care. The patients' sociodemographic and clinical data, their healthcare and non-healthcare resource consumption in the previous 12 months, and the impact of the disease on labor productivity were compiled. Data collected on informal caregivers included sociodemographic data and the impact of caring for a person with AD on their quality of life and labor productivity. Costs were estimated by multiplying the number of consumed resources by their unit prices. The cost of informal care was assessed using the proxy good method, and labor productivity losses were estimated using the human capital method. Costs were estimated by disease severity and are presented per patient per year in 2021 euros (€).

RESULTS

The study sample comprised 171 patients with AD aged 79.1 ± 7.4 years; 68.8% were female, time from diagnosis was 5.8 ± 4.1 years, diagnosis delay was 1.8 ± 2.3 years, and the mean Cumulative Illness Rating Scale-Geriatric (CIRS-G) total was score 8.2 ± 6.0. According to disease severity, 14% had mild cognitive impairment or mild AD, 43.9% moderate AD, and 42.1% severe AD. The average annual cost per patient was €42,336.4 in the most conservative scenario. The greatest proportion of this cost was attributed to direct non-healthcare costs (86%, €36,364.8), followed by direct healthcare costs (8.6%, €3647.1), social care costs (4.6%, €1957.1), and labor productivity losses (less than 1%, €367.4). Informal care was the highest cost item, representing 80% of direct non-healthcare costs and 69% of the total cost. The total direct non-healthcare cost and total cost were significantly higher in moderate to severe disease severities, compared to milder disease severity.

CONCLUSIONS

AD poses a substantial burden on informal caregivers, the national healthcare system, and society at large. Early diagnosis and treatment to prevent disease progression could reduce this economic impact.

Burden of Illness in People with Alzheimer's Disease: A Systematic Review of Epidemiology, Comorbidities and Mortality

BACKGROUND

Alzheimer's disease (AD) is the most common neurodegenerative disease worldwide, and an updated quantification of its impact on morbidity, disability, and mortality is warranted. We conducted a systematic literature review, focusing on the past decade, to characterize AD and assess its impact on affected individuals.

METHODS

Searches of Embase, MEDLINE, and the Cochrane Library were conducted on August 7, 2020 and updated on November 10, 2021. Observational studies from any country reporting incidence, prevalence, comorbidities, and/or outcomes related to disability and mortality/life expectancy, in people with mild cognitive impairment (MCI) due to AD, or mild, moderate, or severe AD dementia, were considered relevant.

RESULTS

Data were extracted from 88 studies (46 incidence/prevalence; 44 comorbidities; 25 mortality-/disability-related outcomes), mostly from Europe, the USA, and Asia. AD dementia diagnosis was confirmed using biomarkers in only 6 studies. Estimated 5-year mortality in AD was 35%, and comorbidity prevalence estimates varied widely (hypertension: 30.2-73.9%; diabetes: 6.0-24.3%; stroke: 2.7-13.7%). Overall, people with AD dementia were more likely to have cardiovascular disease or diabetes than controls, and 5-year mortality in people with AD dementia was double that in the age- and year-matched general population (115.0 vs 60.6 per 1,000 person-years).

CONCLUSIONS

AD is associated with excess morbidity and mortality. Future longitudinal studies of population aging, incorporating biomarker assessment to confirm AD diagnoses, are needed to better characterize the course of MCI due to AD and AD dementia.

Prevalence of Dementia among Patients Hospitalized with Type 2 Diabetes Mellitus in Spain, 2011-2020: Sex-Related Disparities and Impact of the COVID-19 Pandemic

(1) Background: To assess changes in the prevalence of dementia among patients hospitalized with type 2 diabetes (T2DM), to analyze the effects of dementia on in-hospital mortality (IHM) in this population, to evaluate sex differences, and to determine the impact of the COVID-19 pandemic on these parameters. (2) Methods: We used a nationwide discharge database to select all patients with T2DM aged 60 years or over admitted to Spanish hospitals from 2011 to 2020. We identified those with all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD). The effect of sex, age, comorbidity, and COVID-19 on the prevalence of dementia subtypes and on IHM was assessed using multivariable logistic regression. (3) Results: We identified 5,250,810 hospitalizations with T2DM. All-cause dementia was detected in 8.31%, AD in 3.00%, and VaD in 1.55%. The prevalence of all subtypes of dementia increased significantly over time. After multivariable adjustment, higher values were observed in women for all-cause dementia (OR 1.34; 95% CI 1.33-1.35), AD (OR 1.6; 95% CI 1.58-1.62), and VaD (OR 1.12; 95% CI 1.11-1.14). However, female sex was a protective factor for IHM in patients with all-cause dementia (OR 0.90; 95% CI 0.89-0.91), AD (OR 0.89; 95% CI 0.86-0.91), and VaD (OR 0.95; 95% CI 0.91-0.99). IHM among patients with dementia remained stable over time, until 2020, when it increased significantly. Higher age, greater comorbidity, and COVID-19 were associated with IHM in all dementia subtypes. (4) Conclusions: The prevalence of dementia (all-cause, AD, and VaD) in men and women with T2DM increased over time; however, the IHM remained stable until 2020, when it increased significantly, probably because of the COVID-19 pandemic. The prevalence of dementia is higher in women than in men, although female sex is a protective factor for IHM.

Association between multimorbidity status and incident dementia: a prospective cohort study of 245,483 participants

Multimorbidity (the presence of two or more long-term conditions [LTCs]) was suggested to exacerbate the neuronal injuries. The impact of multimorbidity on dementia has not been fully elucidated. We aimed to investigate the association between multimorbidity and dementia risk. We used the prospective data from 245,483 UK Biobank participants during a 9-year follow-up. Multimorbidity status was evaluated based on the LTC counts and multimorbidity patterns. Cox regression models adjusted for potential confounders were used to examine the associations of multimorbidity status with all-cause dementia (ACD), Alzheimer's disease (AD) and vascular dementia (VD). Participants with multimorbidity at baseline had higher risks of ACD and VD, and the risks were elevated with the increase of LTC counts (ACD: hazard ratios [HR] = 1.15, 95% confidence intervals [CI] = 1.01-1.31 with 2 LTCs; HR = 1.18, CI = 1.01-1.39 with 3 LTCs; HR = 1.65, CI = 1.44-1.88 with ≥4 LTCs; VD: HR = 1. 66, CI = 1.24-2.21 with 2 LTCs; HR = 2.10, CI = 1.53-2.88 with 3 LTCs; HR = 3.17, CI = 2.43-4.13 with ≥4 LTCs). Participants with ≥4 LTCs also had a higher risk of AD (HR = 1.34, CI = 1.08-1.66]. Participants with the cardio-cerebrovascular/respiratory/metabolic/musculoskeletal/depressive multimorbidity were 1.46, 1.28, and 2.50 times more likely to develop ACD (HR = 1.46, 95% CI = 1.28-1.67), AD (HR = 1.28, CI = 1.04-1.58), and VD (HR = 2.50, CI = 1.90-3.27), respectively. Those with tumor/genitourinary/digestive disorders had a 11% higher hazard of ACD (HR = 1.11, CI = 1.00-1.24) and a 73% elevated risk of VD (HR = 1.73, CI = 1.37-2.18). The prevention of LTC accumulation and the identification of specific multimorbidity patterns might be beneficial to the prevention of dementia and its subtypes, AD as well as VD.

Relationship between physical activity and incidence of dementia in people aged 50 and over in Europe

OBJECTIVE

The aim of this study was to analyse the relationship between physical activity and the incidence of dementia in a cohort of people aged 50 years or older without dementia from different countries in Europe between the years 2013 and 2015.

METHODS

Prospective longitudinal design study (2013-2015) with a sample of 46,141 people without dementia in 2013 who participated in the SHARE project in waves 5 and 6, where 15 European countries participated. We defined dementia as a self-report of Alzheimer's disease, organic brain syndrome, senility, or any other serious memory impairment during follow-up. The frequency of moderate, vigorous and moderate-to-vigorous physical activity in 2013 was obtained from a validated questionnaire. Incidences of dementia by year (between 2013 and 2015) were calculated for each category of physical activity. Poisson regression models with robust variance were fitted for the association between physical activity and dementia.

RESULTS

The incidence of dementia was 7.4 [95%CI = 6.8-7.9] cases per 1000 persons per year. Very frequent moderate physical activity is a protective factor for dementia independently of the frequency of vigorous physical activity and inversely. The risk of dementia was 2.36 [95%CI = 1.77-3.14] higher in people who hardly ever, or never did moderate-to-vigorous physical activity comparing to people engaged in it more than once a week independently of the baseline cognitive level.

CONCLUSION

Physical activity is associated with the incidence of dementia in people aged 50 and over in both men and women in Europe.

Global incidence of young-onset dementia: A systematic review and meta-analysis

INTRODUCTION

Reliable data on the incidence rates for young-onset dementia (YOD) are lacking, but are necessary for research on disease etiology and to raise awareness among health care professionals.

METHODS

We performed a systematic review and meta-analysis on population-based studies on the incidence of YOD, published between January 1, 1990 and February 1, 2022, according to Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines. Data were analyzed using random-effects meta-analyses. Results were age-standardized, and heterogeneity was assessed by subgroup analyses and meta-regression.

RESULTS

Sixty-one articles were included. Global age-standardized incidence rates increased from 0.17/100,000 in age 30 to 34 years, to 5.14/100,000 in age 60 to 64 years, giving a global total age-standardized incidence rate of 11 per 100,000 in age 30 to 64. This corresponds to 370,000 new YOD cases annually worldwide. Heterogeneity was high and meta-regression showed geographic location significantly influenced this heterogeneity.

DISCUSSION

This meta-analysis shows the current best estimate of YOD incidence. New prospective cohort studies are needed.

Dementia Risk Score for a Population in Southern Europe Calculated Using Competing Risk Models

Background:

Dementia prevention can be addressed if the intervention is applied early.

Objective:

The objective of this study was to develop and validate competing risk models to predict the late risk of dementia based on variables assessed in middle age in a southern European population.

Methods:

We conducted a prospective observational study of the EPIC-Spain cohort that included 25,015 participants. Dementia cases were identified from electronic health records and validated by neurologists. Data were gathered on sociodemographic characteristics and cardiovascular risk factors. To stratify dementia risk, Fine and Gray competing risk prediction models were constructed for the entire sample and for over-55-year-olds. Risk scores were calculated for low (the 30% of the sample with the lowest risk), moderate (> 30% –60%), and high (> 60% –100%) risk.

Results:

The 755 cases of dementia identified represented a cumulative incidence of 3.1% throughout the study period. The AUC of the model for over-55-year-olds was much higher (80.8%) than the overall AUC (68.5%) in the first 15 years of follow-up and remained that way in the subsequent follow-up. The weight of the competing risk of death was greater than that of dementia and especially when the entire population was included.

Conclusion:

This study presents the first dementia risk score calculated in a southern European population in mid-life and followed up for 20 years. The score makes it feasible to achieve the early identification of individuals in a southern European population who could be targeted for the prevention of dementia based on the intensive control of risk factors.

Association Between Egg Consumption and Dementia Risk in the EPIC-Spain Dementia Cohort

Background

Current evidence suggests that egg composition might have potential neuroprotective effects. Our aim was to determine the association between egg consumption and the risk of dementia in a Mediterranean population.

Methods

This study was carried out in 3 centers from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain Dementia Cohort, i.e., 25,015 participants aged 30–70 years, recruited in 1992–1996, and followed up for a mean of 21.5 years.

Results

A total of 774 incident dementia cases were diagnosed and validated, of which 518 were Alzheimer's disease (AD). Data on egg consumption were estimated using a validated dietary history questionnaire at recruitment. Cox proportional hazards models, adjusted for confounders, were used in the analyses. No association was observed between egg consumption and either total dementia [hazard ratio between extreme quartiles (HR_Q4vs.Q1: 1.05; 95% CI 0.85–1.31; p-trend = 0.93)] or AD (HR_Q4vs.Q1 0.93; 95% CI 0.72–1.21; p-trend = 0.50) risks. After dividing the population by adherence to the relative Mediterranean diet (rMED) score, a borderline inverse association was found between egg intake and both total dementia (HR_Q4vs.Q1: 0.52; 95% CI 0.30–0.90; p-trend = 0.10) and AD (HR_Q4vs.Q1: 0.52; 95% CI 0.27–1.01; p-trend = 0.13) risks within participants with low adherence to rMED score. However, no association was observed in participants with medium and high adherence to rMED score.

Conclusion

This prospective study suggests that egg consumption is associated with a reduced risk of dementia, and specifically of AD, in the adult population with low adherence to rMED score; whereas it has no impact in subjects with moderate and high MD adherence.

The Analysis of Oxidative Stress Markers May Increase the Accuracy of the Differential Diagnosis of Alzheimer's Disease with and without Depression

Introduction

The aim of work is to assess the usefulness of oxidative stress parameters in the differential diagnosis of dementia of the Alzheimer’s type and dementia of the Alzheimer’s type with coexisting depression.

Methods

The study involved three groups of people: patients with Alzheimer’s disease (AD) (AD; N=27), patients with Alzheimer’s disease and depression (D) (AD+D; N=30), and a control group that consisted of people without dementia and without depression (C; N=24). The assessment of cognitive functioning was carried out using among alia, Auditory Verbal Learning Test and Verbal Fluency Test. Furthermore, we determined the activity of superoxide dismutase (SOD-1) and superoxide anion radical.

Results

Multiple models with different combinations of independent variables showed that SOD together with Rey delayed recall were the best significant predictors of AD with the area under curve (AUC) of 0.893 (p = 0.001) and superoxide anion radical (O2^•−) together with verbal fluency – sharp objects were the best significant predictors of AD +D diagnosis with the AUC of 0.689 (p = 0.034).

Conclusion

This study confirmed the value of neuropsychological diagnosis and analysis of oxidative stress markers in the diagnosis of AD and major depressive disorder (MDD) in the course of AD. The combination of the use of biochemical markers and neuropsychological tests seems particularly important for differential diagnosis.

Alzheimer's Disease and Diabetes: Role of Diet, Microbiota and Inflammation in Preclinical Models

Alzheimer's disease (AD) is the most common cause of dementia. Epidemiological studies show the association between AD and type 2 diabetes (T2DM), although the mechanisms are not fully understood. Dietary habits and lifestyle, that are risk factors in both diseases, strongly modulate gut microbiota composition. Also, the brain-gut axis plays a relevant role in AD, diabetes and inflammation, through products of bacterial metabolism, like short-chain fatty acids. We provide a comprehensive review of current literature on the relation between dysbiosis, altered inflammatory cytokines profile and microglia in preclinical models of AD, T2DM and models that reproduce both diseases as commonly observed in the clinic. Increased proinflammatory cytokines, such as IL-1β and TNF-α, are widely detected. Microbiome analysis shows alterations in Actinobacteria, Bacteroidetes or Firmicutes phyla, among others. Altered α- and β-diversity is observed in mice depending on genotype, gender and age; therefore, alterations in bacteria taxa highly depend on the models and approaches. We also review the use of pre- and probiotic supplements, that by favoring a healthy microbiome ameliorate AD and T2DM pathologies. Whereas extensive studies have been carried out, further research would be necessary to fully understand the relation between diet, microbiome and inflammation in AD and T2DM.