Preventable risk factors of dementia: Population attributable fractions in a Brazilian population-based study

Episodic memory improvement in illiterate adults attending late-life education irrespective of low socioeconomic status: insights from the PROAME study

The majority of people with dementia live in low or middle-income countries (LMICs) where resources that play a crucial role in brain health, such as quality education, are still not widely available. In Brazil, illiteracy remains a prevalent issue, especially in communities with lower socioeconomic status (SES). The PROAME study set out to explore basic education in illiterate adults as a means to improve cognitive reserve.

Objective

This manuscript aims to explore the relationship between SES and learning, as well as cognitive outcomes, in an older illiterate population.

Methods

This six-month clinical trial (NCT04473235) involved 108 participants, of which 77 concluded all assessments, enrolled in late-life basic education. SES assessments included Quality of Urban Living Index, Municipal Human Development Index and Household SES calculated for each participant. Cognitive assessments encompassed the Free and Cued Selective Reminding Test (FCSRT), a word list to assess reading, and the Beta III matrix.

Results

The sample consisted primarily of women, with a mean age of 58.5. Participants improved their reading (p=0.01) and their FCSRT (p=0.003). Regarding episodic memory, women outperformed men (p=0.007) and younger participants improved more than their older counterparts (p=0.001). There was no association observed between SES and cognitive outcomes.

Conclusion

Irrespective of SES, participants demonstrated positive outcomes after attending basic education. These findings highlight that late life education could be an important non-pharmacologic preventative measure, especially in LMICs.

Poor sleep quality is an important modifiable risk factor for dementia: Population attributable fraction of poor sleep in a Brazilian population-based study

OBJECTIVES

The populational impact of poor sleep quality and the risk of dementia is unclear. We analyzed the Population Attributable Fraction (PAF) of poor sleep quality for dementia, and its association with other two sleep parameters through self-reported and single questions collected in a large-scale Brazilian cohort (ELSI-Brazil).

METHODS

A subset of the ELSI-Brazil with complete responses to sleep quality was retrieved for this study. This is a large representative sample of the Brazilian elderly population with an extensive assessment of sociodemographic and health risk variables. Prevalence of poor sleep quality was estimated according to the complex sample design, and its PAF was measured using a meta-analytic relative risk. A total of 6024 (56.3% women, mean 62.8 ± 9.5 years of age) individuals had complete responses.

RESULTS

The prevalence of poor sleep quality was 24.9% (95%CI 23%-26%), and the PAF of poor sleep quality including other 10 modifiable risk factors of dementia was 52.5% in Brazil. Secondary analyses identified that sleep quality, restorative sleep and sleep drug usage varied considerably according to age ranges, race, and gender.

CONCLUSIONS

Poor sleep quality is an important populational modifiable risk factor for dementia in Brazil. Targeted interventions may provide an important impact in preventing dementia in low- and middle-income countries.

Monitoring risk factors for dementia in middle-aged and older adults: a longitudinal study

Given the importance of dementia syndrome and its impacts on the population, interest in studying modifiable risk factors for dementia is growing.

Objective

To compare the prevalence of risk factors for dementia in middle-aged and older adults over a two-year period and to identify what variables in baseline were predictive of cognitive decline in the follow-up.

Methods

Longitudinal and quantitative study, with follow-up evaluation after two years, conducted with 200 participants aged 45 years or more, registered in Primary Care Units. In the baseline (2018/2019) and follow-up (2021) assessments, sociodemographic data were collected, and cognitive performance and risk factors for dementia were evaluated (education, hearing loss, head trauma, high blood pressure, alcohol use, obesity, smoking, depressive symptoms, social isolation, physical inactivity, and diabetes mellitus). Data were compared using the McNemar's test. Individual multinomial logistic regression models were performed to identify the factors associated with cognitive decline after two years.

Results

The percentages of low education, traumatic brain injury, and smoking remained the same in both assessments. There was a significant increase in the prevalence of high blood pressure (from 55.0 to 62.0%) and physical inactivity (from 58.5 to 74.5%) and a significant reduction in social isolation (from 25.0 to 18.0%). Participants with depressive symptoms in baseline had a higher risk of cognitive decline in follow-up.

Conclusion

There was an increase in the prevalence of high blood pressure and physical inactivity and a reduction in social isolation after two years. Depressive symptoms predict cognitive decline.

Bias assessment and correction for Levin's population attributable fraction in the presence of confounding

In 1953, Morton Levin introduced a simple approach to estimating population attributable fractions (PAF) depending only on risk factor prevalence and relative risk. This formula and its extensions are still in widespread use today, particularly to estimate PAF in populations where individual data is unavailable. Unfortunately, Levin's approach is known to be asymptotically biased for the PAF when the risk factor-disease relationship is confounded even if relative risks that are correctly adjusted for confounding are used in the estimator. Here we describe a simple re-expression of Miettinen's estimand that depends on the causal relative risk, the unadjusted relative risk and the population risk factor prevalence. While this re-expression is not new, it has been underappreciated in the literature, and the associated estimator may be useful in estimating PAF in populations when individual data is unavailable provided estimated adjusted and unadjusted relative risks can be transported to the population of interest. Using the re-expressed estimand, we develop novel analytic formulae for the relative and absolute asymptotic bias in Levin's formula, solidifying earlier work by Darrow and Steenland that used simulations to investigate this bias. We extend all results to settings with non-binary valued risk factors and continuous exposures and discuss the utility of these results in estimating PAF in practice.

The Brain Health Diplomat's Toolkit: supporting brain health diplomacy leaders in Latin America and the Caribbean

Maintaining and improving brain health, one of the most critical global challenges of this century, necessitates innovative, interdisciplinary, and collaborative strategies to address the growing challenges in Latin America and the Caribbean. This paper introduces Brain Health Diplomacy (BHD) as a pioneering approach to bridge disciplinary and geographic boundaries and mobilize resources to promote equitable brain health outcomes in the region. Our framework provides a toolkit for emerging brain health leaders, equipping them with essential concepts and practical resources to apply in their professional work and collaborations. By providing case studies, we highlight the importance of culturally sensitive, region-specific interventions to address unique needs of vulnerable populations. By encouraging dialogue, ideation, and cross-sector discussions, we aspire to develop new research, policy, and programmatic avenues. The novel BHD approach has the potential to revolutionize brain health across the region and beyond, ultimately contributing to a more equitable global cognitive health landscape.

Variations in cognition by human capital characteristics: a cross-sectional analysis of Brazilian older adults

Introduction

The productivity of individuals is assumed to decline upon reaching old age when cognitive ability is considered. This assumption is false, especially if the human development characteristics of people are analyzed, which highlights the need to recognize the heterogeneity among subpopulations.

Methods

Using Wave two of the Brazilian Longitudinal Study on Aging, conducted from 2019 to 2021, this study explored the onset and speed of cognitive aging among older individuals aged at least 60 in Brazil, with reference to their education and income levels.

Results

It was observed that although higher human capital characteristics yielded results toward later cognitive decline, women benefited more from having higher educational attainment levels. Such a pattern was similar among men and increased income levels. Disparities in cognitive performance, whether from education or income, were greatest at age 60, and this advantage diminished as age progressed.

Conclusion

Viewing the older population as homogeneous in terms of health function is restrictive. It should be recognized that variations in social status affect individuals' health status into old age and therefore their respective potential for productivity should be maximized.

Systematic review and meta-analysis on population attributable fraction for physical inactivity to dementia

INTRODUCTION

The number of cases of dementia attributable to physical inactivity remains unclear due to heterogeneity in physical inactivity definitions and statistical approaches used.

METHODS

Studies that used population-based samples to estimate the population attributable fraction (PAF) of physical inactivity for dementia were included in this review. Weighted PAFs were adjusted for communality among the risk factors (i.e., inactive persons may also share other risk factors) analyzed. Values were reported as percentage (%) of cases of dementia attributable to physical inactivity.

RESULTS

We included 22 studies. The overall impact of physical inactivity, defined by any criteria, on dementia ranged from 6.6% (95% CI: 3.6%, 9.6%; weighted) to 16.6% (95% CI: 14.4%, 18.9%; unweighted). Studies using the WHO criterion for physical inactivity estimated a higher unweighted impact (β = 7.3%; 95% CI: 2.0%, 12.6%) than studies using other criteria.

DISCUSSION

Conservatively, one in 15 cases of dementia may be attributable to physical inactivity, defined by any criteria.

Factors associated with healthy aging in Latin American populations

Latin American populations may present patterns of sociodemographic, ethnic and cultural diversity that can defy current universal models of healthy aging. The potential combination of risk factors that influence aging across populations in Latin American and Caribbean (LAC) countries is unknown. Compared to other regions where classical factors such as age and sex drive healthy aging, higher disparity-related factors and between-country variability could influence healthy aging in LAC countries. We investigated the combined impact of social determinants of health (SDH), lifestyle factors, cardiometabolic factors, mental health symptoms and demographics (age, sex) on healthy aging (cognition and functional ability) across LAC countries with different levels of socioeconomic development using cross-sectional and longitudinal machine learning models (n = 44,394 participants). Risk factors associated with social and health disparities, including SDH (β > 0.3), mental health (β > 0.6) and cardiometabolic risks (β > 0.22), significantly influenced healthy aging more than age and sex (with null or smaller effects: β < 0.2). These heterogeneous patterns were more pronounced in low-income to middle-income LAC countries compared to high-income LAC countries (cross-sectional comparisons), and in an upper-income to middle-income LAC country, Costa Rica, compared to China, a non-upper-income to middle-income LAC country (longitudinal comparisons). These inequity-associated and region-specific patterns inform national risk assessments of healthy aging in LAC countries and regionally tailored public health interventions.

Race‐related population attributable fraction of preventable risk factors of dementia: A Latino population‐based study

Background

Risk factors for dementia have distinct frequency and impact in relation to race. Our aim was to identify differences in modifiable risk factors of dementia related to races and estimate their population attributable fraction (PAF).

Methods

An epidemiological cohort was used to estimate the prevalence of 10 modifiable risk factors for dementia among five races—White, Black, Brown, Asian, and Indigenous. Sample weighting was used to estimate the prevalence and PAF of each risk factor in each race.

Results

A total of 9070 individuals were included. Overall adjusted PAF was the lowest in Indigenous (38.9%), and Asian individuals (41.2%). Race‐related prevalence of individual risk factors was widely variable in our population, but hearing loss was the most important contributor to the overall PAF in all races.

Conclusions

Public policies aiming to reduce preventable risk factors for dementia should take into consideration the race of the target populations.

HIGHLIGHTS

Preventable risk factors for dementia vary according to race.

Hearing loss presented the highest prevalence among all races studied.

Indigenous and Asian individuals presented the lowest population attributable fractions.

Black and Brown individuals were more vulnerable to social determinants.

Risk factors for dementia in the context of cardiovascular disease: A protocol of an overview of reviews

Background

Dementia is a major public health priority. Although there is abundant evidence of an association between dementia and poor cardiovascular health, findings have been inconsistent and uncertain in identifying which factors increase dementia risk in those with cardiovascular disease. Indeed, multiple variables including sociodemographic, economic, health, lifestyle and education may indicate who is at higher vs. lower dementia risk and could be used in prediction modelling. Therefore, the aim of this review is to synthesise evidence on the key risk factors for dementia in those with a history of cardiovascular disease.

Methods

This is an overview of reviews protocol, registered on PROSPERO (CRD42021265363). Four electronic databases including MEDLINE, EMBASE, PsycINFO, and the Cochrane Database of Systematic Reviews will be searched. Studies will be included if they are systematic reviews and/or meta-analyses that have investigated the risk of incident dementia (all-cause and subtypes including Alzheimer’s disease and vascular dementia) in people with a history of coronary heart disease, heart failure, atrial fibrillation, hypertension, hyperlipidaemia, and vascular stiffness. Study selection will be completed by two independent researchers according to the eligibility criteria, and conflicts resolved by a third reviewer. References will be exported into Covidence for title and abstract sifting, full-text review, and data extraction. Methodological quality will be assessed using the AMSTAR-2 criteria and confidence of evidence will be assessed using the GRADE classification. This overview of reviews will follow PRISMA guidelines. If there is sufficient homogeneity in the data, the results will be pooled, and a meta-analysis conducted to determine the strength of association between each risk factor and incident all-cause dementia and its subtypes for each cardiovascular diagnoses separately.

Discussion

We will create a comprehensive summary of the key risk factors linking cardiovascular diseases to risk of incident dementia. This knowledge is essential for informing risk predictive model development as well as the development of risk reduction and prevention strategies.