Prevalence of dementia in Latin America and Caribbean countries: Systematic review and meta-analyses exploring age, sex, rurality, and education as possible determinants

Motoric cognitive risk syndrome as a predictor of mortality in older male adults with cancer: A prospective cohort study in Peru

We aimed to assess motoric cognitive risk syndrome (MCRS) as a mortality predictor in older male adults with cancer at Centro Médico Naval (CEMENA) in Peru from 2012 to 2015. We conducted a secondary analysis of a prospective cohort within CEMENA's Geriatrics Service. We considered all-cause mortality as the primary outcome. MCRS was defined as slow gait speed, cognitive impairment, preserved activities of daily living, and absence of dementia. We utilized Poisson family generalized linear models with a logarithmic link function and robust variance to calculate both crude and adjusted relative risks (RR) with 95 % confidence intervals (95 % CI). We included 832 older male adults, with an MCRS frequency of 18.27 % (n = 152) and a mortality incidence of 22.84 % (n = 190). MCRS was a predictor of mortality in older adults at the end of follow-up (aRR=2.55; 95 % CI: 2.13-2.66). Survival was lower in older adults with MCRS (log-rank test p < 0.001). MCRS was a mortality predictor in older male adults with cancer.

Associations between nutritional status and abdominal adiposity with cognitive domains and depressive symptoms in older persons with multimorbidity: Understanding an understudied population

BACKGROUND

Malnutrition is a prevalent issue among older persons and has been linked to adverse outcomes. Limited information exists regarding its connection with cognition and depression in older persons burdened by chronic diseases, experiencing heightened nutritional and psychosocial vulnerability. In this study, we examined the association between nutritional status, cognitive performance, and depressive symptomatology, in a cohort of older persons with multimorbidity.

METHODS

This was a cross-sectional study of 114 pluripathological older persons. Nutritional status was assessed through Mini Nutritional Assessment (MNA), body mass index (BMI) and waist and calf circumferences. Cognition was assessed using Montreal Cognitive Assessment (MoCA) and depressive symptoms were measured with the 15-item Geriatric Depression Scale (GDS-15).

RESULTS

MNA score was positively correlated with the MoCA's visuospatial score (rho=0.262) and, participants with normal nutritional status according to MNA, performed better in orientation (p=0.037) and abstraction (p=0.013) domains. MNA was also associated with depressive symptoms, with odds 8.6 times higher in malnourished participants (AOR 8.6, 95% CI 2.6-28.8, p=0.000). Abdominal obesity, meanwhile, was associated with a decrease of 3.33 points in the overall MoCA score (β -3.33, 95% CI=-5.92; -0.73, p=0.013).

CONCLUSION

In older persons with multimorbidity, abdominal obesity and malnutrition were factors associated with lower global and domain-specific cognitive performance and increased depressive symptomatology.

Vascular cognitive impairment and dementia: a narrative review

Vascular cognitive impairment (VCI) is the second most common cause of cognitive impairment after Alzheimer's disease. The VCI spectrum involves a decline in cognition attributable to vascular pathologies (e.g., large infarcts or hemorrhages, microinfarcts, microbleeds, lacunar infarcts, white matter hyperintensities, and perivascular space dilation). Pathophysiological mechanisms include direct tissue injury, small vessel disease, inflammaging (inflammation + aging), atrophy, and altered neurotransmission. VCI is diagnosed using distinct clinical and radiological criteria. It may lead to long-term disability and reduced quality of life. An essential factor for reducing cognitive impairment incidence is preventing stroke by managing traditional and non-traditional cerebrovascular risk factors. This article reviews the spectrum of VCI, epidemiology, risk factors, pathophysiology, diagnosis, available treatment, and preventive strategies.

Educational disparities in brain health and dementia across Latin America and the United States

BACKGROUND

Education influences brain health and dementia. However, its impact across regions, specifically Latin America (LA) and the United States (US), is unknown.

METHODS

A total of 1412 participants comprising controls, patients with Alzheimer's disease (AD), and frontotemporal lobar degeneration (FTLD) from LA and the US were included. We studied the association of education with brain volume and functional connectivity while controlling for imaging quality and variability, age, sex, total intracranial volume (TIV), and recording type.

RESULTS

Education influenced brain measures, explaining 24%-98% of the geographical differences. The educational disparities between LA and the US were associated with gray matter volume and connectivity variations, especially in LA and AD patients. Education emerged as a critical factor in classifying aging and dementia across regions.

DISCUSSION

The results underscore the impact of education on brain structure and function in LA, highlighting the importance of incorporating educational factors into diagnosing, care, and prevention, and emphasizing the need for global diversity in research.

HIGHLIGHTS

Lower education was linked to reduced brain volume and connectivity in healthy controls (HCs), Alzheimer's disease (AD), and frontotemporal lobar degeneration (FTLD). Latin American cohorts have lower educational levels compared to the those in the United States. Educational disparities majorly drive brain health differences between regions. Educational differences were significant in both conditions, but more in AD than FTLD. Education stands as a critical factor in classifying aging and dementia across regions.

Knowledge of dementia and Alzheimer's disease among healthcare professionals in Peru

BACKGROUND

 Primary care physicians and other healthcare providers report feeling unprepared to treat persons with dementia (PWD), especially in developing countries OBJECTIVE:  We aimed to assess the knowledge of dementia and Alzheimer's disease (AD) among health professionals in both primary and tertiary care in Peru.

METHODS

 We conducted an in-person and virtual survey of healthcare professionals trained in Peru throughout the year 2020. The survey was developed based on a previously published one and reviewed by an expert panel. We compared groups using a Chi-squared test. A Bonferroni corrected p-value of 0.008 was used for statistical significance.

RESULTS

 Out of 804 surveys, we excluded 56 due to incomplete data. A total of 41.6% of respondents were doctors and 21.8%, nurses. One fifth of participants did not recognize AD as a cause of dementia and over half considered "senile dementia" a valid clinical entity. Scores were higher among those with postgraduate training, multiple patients with dementia, or those who had practiced for over 10 years.

CONCLUSION

 There is a low level of knowledge of dementia and AD among health professionals in Peru, which worsens outside of Lima. Pernicious ideas, such as senile dementia, are still significantly present among respondents.

Seaweeds as Source of Bioactive Pigments with Neuroprotective and/or Anti-Neurodegenerative Activities: Astaxanthin and Fucoxanthin

The marine kingdom is an important source of a huge variety of scaffolds inspiring the design of new drugs. The complex molecules found in the oceans present a great challenge to organic and medicinal chemists. However, the wide variety of biological activities they can display is worth the effort. In this article, we present an overview of different seaweeds as potential sources of bioactive pigments with activity against neurodegenerative diseases, especially due to their neuroprotective effects. Along with a broad introduction to seaweed as a source of bioactive pigments, this review is especially focused on astaxanthin and fucoxanthin as potential neuroprotective and/or anti-neurodegenerative agents. PubMed and SciFinder were used as the main sources to search and select the most relevant scientific articles within the field.

Charting Alzheimer's Disease and Dementia: Epidemiological Insights, Risk Factors and Prevention Pathways

Alzheimer's disease (AD), the most common cause of dementia, is a complex and multifactorial condition without cure at present. The latest treatments, based on anti-amyloid monoclonal antibodies, have only a modest effect in reducing the progression of cognitive decline in AD, whereas the possibility of preventing AD has become a crucial area of research. In fact, recent studies have observed a decrease in dementia incidence in developed regions such as the US and Europe. However, these trends have not been mirrored in non-Western countries (Japan or China), and the contributing factors of this reduction remain unclear. The Lancet Commission has delineated a constrained classification of 12 risk factors across different life stages. Nevertheless, the scientific literature has pointed to over 200 factors-including sociodemographic, medical, psychological, and sociocultural conditions-related to the development of dementia/AD. This narrative review aims to synthesize the risk/protective factors of dementia/AD. Essentially, we found that risk/protective factors vary between individuals and populations, complicating the creation of a unified prevention strategy. Moreover, dementia/AD explanatory mechanisms involve a diverse array of genetic and environmental factors that interact from the early stages of life. In the future, studies across different population-based cohorts are essential to validate risk/protective factors of dementia. This evidence would help develop public health policies to decrease the incidence of dementia.

Health literacy, but not memory, is associated with hippocampal connectivity in adults with low levels of formal education

INTRODUCTION

The influence of hippocampal connectivity on memory performance is well established in individuals with high educational attainment. However, the role of hippocampal connectivity in illiterate populations remains poorly understood.

METHODS

Thirty-five illiterate adults were administered a literacy assessment (Test of Functional Health Literacy in Adults [TOFHLA]), structural and resting state functional magnetic resonance imaging, and an episodic memory test (Free and Cued Selective Reminding Test). Illiteracy was defined as a TOFHLA score < 53. We evaluated the correlation between hippocampal connectivity at rest and both free recall and literacy scores.

RESULTS

Participants were mostly female (57.1%) and self-declared as being Black individuals (84.8%), with a median age of 50 years. The median TOFHLA literacy score was 28.0 [21.0; 42.5] out of 100 points and the median free recall score was 30.0 [26.2; 35] out of 48 points. The median gray matter volume of both the left and right hippocampi was 2.3 [2.1; 2.4] cm3. We observed a significant connectivity between both hippocampi and the precuneus and the ventral medial prefrontal cortex. The right hippocampal connectivity positively correlated with the literacy scores (β = 0.58, P = 0.008). There was no significant association between episodic memory and hippocampal connectivity. Neither memory nor literacy scores correlated with hippocampal gray matter volume.

DISCUSSION

Low literacy levels correlated with hippocampal connectivity in illiterate adults. The lack of association with memory scores might be associated with low brain reserve in this sample.

Highlights

A significant link was found between health literacy and hippocampal connectivity.Enhanced hippocampus- ventromedial prefrontal cortex connectivity suggests potential cognitive reserve improvement.Higher cognitive reserve may protect against hippocampal atrophy and neurodegeneration.Health literacy improvements could help prevent cognitive impairment in illiterate populations.Study highlights importance of considering structural racism in brain connectivity research.

Advancements in dementia research, diagnostics, and care in Latin America: Highlights from the 2023 Alzheimer's Association International conference satellite symposium in Mexico City

INTRODUCTION

While Latin America (LatAm) is facing an increasing burden of dementia due to the rapid aging of the population, it remains underrepresented in dementia research, diagnostics, and care.

METHODS

In 2023, the Alzheimer's Association hosted its eighth satellite symposium in Mexico, highlighting emerging dementia research, priorities, and challenges within LatAm.

RESULTS

Significant initiatives in the region, including intracountry support, showcased their efforts in fostering national and international collaborations; genetic studies unveiled the unique genetic admixture in LatAm; researchers conducting emerging clinical trials discussed ongoing culturally specific interventions; and the urgent need to harmonize practices and studies, improve diagnosis and care, and use affordable biomarkers in the region was highlighted.

DISCUSSION

The myriad of topics discussed at the 2023 AAIC satellite symposium highlighted the growing research efforts in LatAm, providing valuable insights into dementia biology, genetics, epidemiology, treatment, and care.

Predictors of cognitive change in cognitively healthy older women in Panama: the PARI-HD study

Background

Evidence suggests that a combination of biological and social factors influence risk of dementia differently for women and men. In healthy older women, several factors may contribute to changes in cognition.

Objective

Describe the characteristics associated with variation in cognition in a sample of cognitively healthy older Panamanian women.

Methods

The study includes cross-sectional analyses of cognitive domains at baseline (n = 357) and 17-month (SD = 2.0) follow-up (n = 200) for women aged 60 years and older enrolled in the Panama Aging Research Initiative-Health Disparities (PARI-HD) study. Instruments included clinical questionnaires, physiological measures, and a neuropsychological test battery assessing global cognition and seven cognitive domains. Multiple regression analyses examined the associations between demographic and clinical characteristics and cognition at baseline. Repeated measures analyses were used to investigate changes in cognition from baseline to follow-up.

Results

On average, participants were 68.6 years of age (SD = 5.9) with 16.1 years of education (SD = 4.7). Age, income, and education showed robust associations with baseline cognition. Subjective cognitive impairment was associated with lower performance in global cognition, verbal learning, and memory domains. Only performance in the attention domain decreased at follow-up, and subjective health state and depressive symptoms significantly predicted the change in attention.

Discussion

Our study findings contribute to the investigation of cognitive health in older Hispanic women and to the understanding of sociodemographic and health-related factors associated with cognitive decline and the progression to cognitive impairment and dementia.

A Systematic Review and Meta-Analysis on the Prevalence of Mild Cognitive Impairment and Dementia in Mexico

INTRODUCTION

Age remains one of the major risk factors for the onset of mild cognitive impairment (MCI) and dementia. Studies on the prevalence of these conditions in Mexico used different methods, tools, and populations with different health statuses. All these heterogeneous results may be a problem in identifying the true prevalence of MCI and dementia in Mexico. To our knowledge, there is not a systematic review available that presents essential figures on the prevalence of these conditions in Mexico. Therefore, we intend to access the maximum number of reports published on the topic and determine the prevalence of MCI and dementia in older Mexican adults.

METHODS

A systematic review using PubMed, Cochrane, Research Gate, Lilacs, and Scielo databases was performed. Meta-analysis of the prevalence of MCI and dementia was performed using a random-effects model and presented in a forest plot among cross-sectional, epidemiological, and pooled studies.

RESULTS

Sixteen articles were included. The overall prevalence of MCI of 18% (95% CI 0.10-0.27) was estimated from pooled information from 12 selected studies, in women 21% (95% CI 0.08-0.38) and in men 18% (95% CI 0.06-0.33). The overall prevalence of dementia of 10% (95% CI 0.06-0.14) was estimated from pooled information from 9 selected studies, in women 14% (95% CI 0.05-0.25) and in men 10% (95% CI 0.04-0.17).

CONCLUSION

Mexican older individuals have a similar prevalence of dementia and MCI as reported by international data; nevertheless, the prevalence is higher than in some Latin American countries. Mexico has particular issues that must be resolved, such as a lack of research in the southern regions of the country and the high incidence of comorbidities.

Prevalence and risk factors for dementia and mild cognitive impairment among older people in Southeast China: a community-based study

BACKGROUND

With the aging population, the number of individuals with dementia in China is increasing rapidly. This community-based study aimed to investigate the prevalence and risk factors for dementia and mild cognitive impairment (MCI) among older adults in China.

METHODS

In this study, 20,070 individuals aged ≥ 65 were recruited between January 1, 2022, and February 1, 2023, from ten communities in Xiamen City, China. We collected data on age, sex, level of education, and medical history, as well as global cognition and functional status. The prevalence of dementia and MCI was examined, and the risk factors for different groups were assessed.

RESULTS

The overall prevalence of dementia and MCI was approximately 5.4% (95% confidence interval [CI], 5.1-5.7) and 7.7% (95% CI, 7.4-8.1), respectively. The results also indicated that dementia and MCI share similar risk factors, including older age, female sex, hypertension, and diabetes mellitus. Compared with individuals with no formal education, those with > 6 years of education had an odds ratio for MCI of 1.83 (95% CI, 1.49-2.25). We also found that only 5.5% of the positive participants chose to be referred to the hospital for further diagnosis and treatment during follow-up visits.

CONCLUSIONS

This study estimated the prevalence and risk factors for dementia and MCI among individuals aged ≥ 65 years in Southeast China. These findings are crucial for preventing and managing dementia and MCI in China.

Plasma ADAM10 Levels and Their Association with Alzheimer's Disease Diagnosis in Older Adults with Fewer Years of Formal Education

INTRODUCTION

Low educational attainment is a potential risk factor for Alzheimer's disease (AD) development. Alpha-secretase ADAM10 plays a central role in AD pathology, attenuating the formation of beta-amyloid peptides and, therefore, their aggregation into senile plaques. This study seeks to investigate ADAM10 as a blood-based biomarker in mild cognitive impairment (MCI) and AD in a diverse group of community-dwelling older adults, focusing on those with limited educational attainment.

METHODS

Participants were recruited from public health services. Cognition was evaluated using Mini-Mental State Examination (MMSE) and Addenbrooke's Cognitive Examination - Revised (ACE-R) batteries. Blood samples were collected to analyze plasma ADAM10 levels. A logistic regression was conducted to verify the influence of plasma ADAM10 on the AD diagnosis.

RESULTS

Significant differences in age, years of education, prescribed medications, and cognitive test scores were found between the MCI and AD groups. Regarding cognitive performance, both ACE-R and MMSE scores displayed significant differences between groups, with post hoc analyses highlighting these distinctions, particularly between AD and cognitively unimpaired individuals. Elevated plasma ADAM10 levels were associated with a 4.5-fold increase in the likelihood of a diagnosis of MCI and a 5.9-fold increase in the likelihood of a diagnosis of AD. These findings suggest ADAM10 levels in plasma as a valuable biomarker for assessing cognitive status in older individuals with low education attainment.

CONCLUSION

This study underscores the potential utility of plasma ADAM10 levels as a blood-based biomarker for cognitive status, especially in individuals with low educational backgrounds, shedding light on their relevance in AD development and diagnosis.

Biophysical models applied to dementia patients reveal links between geographical origin, gender, disease duration, and loss of neural inhibition

BACKGROUND

The hypothesis of decreased neural inhibition in dementia has been sparsely studied in functional magnetic resonance imaging (fMRI) data across patients with different dementia subtypes, and the role of social and demographic heterogeneities on this hypothesis remains to be addressed.

METHODS

We inferred regional inhibition by fitting a biophysical whole-brain model (dynamic mean field model with realistic inter-areal connectivity) to fMRI data from 414 participants, including patients with Alzheimer's disease, behavioral variant frontotemporal dementia, and controls. We then investigated the effect of disease condition, and demographic and clinical variables on the local inhibitory feedback, a variable related to the maintenance of balanced neural excitation/inhibition.

RESULTS

Decreased local inhibitory feedback was inferred from the biophysical modeling results in dementia patients, specific to brain areas presenting neurodegeneration. This loss of local inhibition correlated positively with years with disease, and showed differences regarding the gender and geographical origin of the patients. The model correctly reproduced known disease-related changes in functional connectivity.

CONCLUSIONS

Results suggest a critical link between abnormal neural and circuit-level excitability levels, the loss of grey matter observed in dementia, and the reorganization of functional connectivity, while highlighting the sensitivity of the underlying biophysical mechanism to demographic and clinical heterogeneities in the patient population.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Sex and Socioeconomic Disparities in Dementia Risk: A Population-Attributable Fraction Analysis in Argentina

INTRODUCTION

Twelve modifiable risk factors (RFs) account for 40% of dementia cases worldwide. However, limited data exist on such factors in middle- and low-income countries. We aimed to estimate the population-attributable fractions (PAFs) for the 12 RFs in Argentina, assessing changes over a decade and exploring socioeconomic and sex influences.

METHODS

We conducted cross-sectional analyses of the 12 RFs from Argentinian surveys conducted in 2009, 2015, and 2018, including 96,321 people. We calculated PAFs and stratified estimates based on sex and income.

RESULTS

We estimated an overall PAF of 59.6% (95% CI = 58.9-60.3%). The largest PAFs were hypertension = 9.3% (8.7-9.9%), physical inactivity = 7.4% (6.8-8.2%), and obesity = 7.4% (6.8-7.9%). Men were more impacted by excessive alcohol, while women by isolation and smoking. Lower income linked to higher PAFs in education, hypertension, and obesity.

DISCUSSION

Argentina has a higher PAF for dementia than the world population, with distinct RF distribution. PAF varied by sex and economic status, advocating tailored prevention strategies.

Association between cardiovascular risk factors and cognitive impairment in adults aged 60 years or older from Chile: a cross-sectional study

BACKGROUND

Few studies in Latin America have examined the association between cardiovascular risk factors and cognitive impairment (CI) in a nationally representative sample. Therefore, this study aimed to estimate the prevalence of CI in a nationally representative sample of adults aged 60 years or older from Chile and to investigate the association between cardiovascular risk factors and CI.

METHODS

Data from the cross-sectional 2016-2017 National Health Survey of Chile, which included 2031 adults (63.7% women) was used. Body mass index, metabolic syndrome (blood pressure, triglycerides, fasting glucose or treatment for diabetics, waist circumference, and HDL cholesterol), risk of cardiovascular disease (history and measured variables, using the Framingham risk score), tobacco use, and physical activity were measured. CI was assessed using the Mini-Mental Status Examination (MMSE).

RESULTS

Overall, the prevalence of CI was 12.2% at the national level. Significant differences in CI were observed by age, education level, risk of cardiovascular disease, and smoking. High risk of cardiovascular disease was associated with higher odds of CI (OR: 2.04; 95%CI: 1.20-3.45) compared to low risk. Smoking was significantly associated with a lower likelihood of CI (OR: 0.56; 95%CI: 0.36-0.87) compared to never smoking. Body mass index, metabolic syndrome, and physical activity were not associated with CI.

CONCLUSIONS

This study provided additional support for previous findings on the relationship between cognitive decline and an elevated risk of cardiovascular disease. Worse CI was associated with the group with the highest risk of cardiovascular disease, and the presence of lifestyle factors, such as obesity and physical inactivity, exacerbate this relationship, but not being a current smoker.

Epidemiology of neurocognitive disorders in adults from urban-marginalized areas: a door-to-door population-based study in Puente Piedra, Lima, Peru

Background

In Latin America (LA), the prevalence of dementia is expected to triple to 150 million people by 2050. The 2020 Lancet Commission report identified several modifiable dementia risk factors, yet few social and environmental factors, most relevant to vulnerable regions of LA, were highlighted in this report. We sought to assess the epidemiology of neurocognitive disorders (NCD) in Puente Piedra, one of the most socially and economically vulnerable districts of Lima, the capital of Peru.

Methodology

This was a cross-sectional door-to-door observational study that used two-stage household sampling. One young adult (30-59 years) and one older adult (>60 years) per household were enrolled. We collected demographic, clinical, and neurocognitive data. Addenbrooke's Cognitive Examination (young adults) and the RUDAS-PE (older adults) were used, classifying participants as cognitively normal, possible mild NCD, or possible major NCD.

Results

We enrolled 247 participants (median age 46 years; 67% female). One-fourth had not completed secondary school and more than 50% completed only secondary school. Most participants were housewives (46%) and 21% did not have health insurance. The overall prevalence of possible NCD was 30% (25.6 and 41.8% among younger adults and older adults, respectively). Among younger adults, those ages 55-59 years more frequently had NCD (70%) compared to younger age ranges. Among older adults, only 3 subjects (4.5%) had major NCD.

Conclusion

We found a high frequency of possible NCDs in a socially and economically vulnerable community in Lima, Peru, with younger adults showing levels of NCD higher than expected. Our findings support the need for health systems to incorporate cognitive screenings programs for NCD in younger ages. Future research on NCD would include younger populations, particularly in vulnerable communities.

Digital phenotyping: An equal opportunity approach to reducing disparities in Alzheimer's disease and related dementia research

A rapidly aging world population is fueling a concomitant increase in Alzheimer's disease (AD) and related dementias (ADRD). Scientific inquiry, however, has largely focused on White populations in Australia, the European Union, and North America. As such, there is an incomplete understanding of AD in other populations. In this perspective, we describe research efforts and challenges of cohort studies from three regions of the world: Central America, East Africa, and East Asia. These cohorts are engaging with the Davos Alzheimer's Collaborative (DAC), a global partnership that brings together cohorts from around the world to advance understanding of AD. Each cohort is poised to leverage the widespread use of mobile devices to integrate digital phenotyping into current methodologies and mitigate the lack of representativeness in AD research of racial and ethnic minorities across the globe. In addition to methods that these three cohorts are already using, DAC has developed a digital phenotyping protocol that can collect ADRD-related data remotely via smartphone and/or in clinic via a tablet to generate a common data elements digital dataset that can be harmonized with additional clinical and molecular data being collected at each cohort site and when combined across cohorts and made accessible can provide a global data resource that is more racially/ethnically represented of the world population.

Latin American Initiative for Lifestyle Intervention to Prevent Cognitive Decline (LatAm-FINGERS): Study design and harmonization

INTRODUCTION

Latin American Initiative for Lifestyle Intervention to Prevent Cognitive Decline (LatAm-FINGERS) is the first non-pharmacological multicenter randomized clinical trial (RCT) to prevent cognitive impairment in Latin America (LA). Our aim is to present the study design and discuss the strategies used for multicultural harmonization.

METHODS

This 1-year RCT (working on a 1-year extension) investigates the feasibility of a multi-domain lifestyle intervention in LA and the efficacy of the intervention, primarily on cognitive function. An external harmonization process was carried out to follow the FINGER model, and an internal harmonization was performed to ensure this study was feasible and comparable across the 12 participating LA countries.

RESULTS

Currently, 1549 participants have been screened, and 815 randomized. Participants are ethnically diverse (56% are Nestizo) and have high cardiovascular risk (39% have metabolic syndrome).

DISCUSSION

LatAm-FINGERS overcame a significant challenge to combine the region's diversity into a multi-domain risk reduction intervention feasible across LA while preserving the original FINGER design.

Repurposing of Tibolone in Alzheimer's Disease

Alzheimer's disease (AD) is a debilitating neurodegenerative disease characterised by the accumulation of amyloid-beta and tau in the brain, leading to the progressive loss of memory and cognition. The causes of its pathogenesis are still not fully understood, but some risk factors, such as age, genetics, and hormones, may play a crucial role. Studies show that postmenopausal women have a higher risk of developing AD, possibly due to the decrease in hormone levels, especially oestrogen, which may be directly related to a reduction in the activity of oestrogen receptors, especially beta (ERβ), which favours a more hostile cellular environment, leading to mitochondrial dysfunction, mainly affecting key processes related to transport, metabolism, and oxidative phosphorylation. Given the influence of hormones on biological processes at the mitochondrial level, hormone therapies are of clinical interest to reduce the risk or delay the onset of symptoms associated with AD. One drug with such potential is tibolone, which is used in clinics to treat menopause-related symptoms. It can reduce amyloid burden and have benefits on mitochondrial integrity and dynamics. Many of its protective effects are mediated through steroid receptors and may also be related to neuroglobin, whose elevated levels have been shown to protect against neurological diseases. Its importance has increased exponentially due to its implication in the pathogenesis of AD. In this review, we discuss recent advances in tibolone, focusing on its mitochondrial-protective effects, and highlight how valuable this compound could be as a therapeutic alternative to mitigate the molecular pathways characteristic of AD.

A task force for diagnosis and treatment of people with Alzheimer's disease in Latin America

Alzheimer's disease (AD) represents a substantial burden to patients, their caregivers, health systems, and society in Latin America and the Caribbean (LAC). This impact is exacerbated by limited access to diagnosis, specialized care, and therapies for AD within and among nations. The region has varied geographic, ethnic, cultural, and economic conditions, which create unique challenges to AD diagnosis and management. To address these issues, the Americas Health Foundation convened a panel of eight neurologists, geriatricians, and psychiatrists from Argentina, Brazil, Colombia, Ecuador, Guatemala, Mexico, and Peru who are experts in AD for a three-day virtual meeting to discuss best practices for AD diagnosis and treatment in LAC and create a manuscript offering recommendations to address identified barriers. In LAC, several barriers hamper diagnosing and treating people with dementia. These barriers include access to healthcare, fragmented healthcare systems, limited research funding, unstandardized diagnosis and treatment, genetic heterogeneity, and varying social determinants of health. Additional training for physicians and other healthcare workers at the primary care level, region-specific or adequately adapted cognitive tests, increased public healthcare insurance coverage of testing and treatment, and dedicated search strategies to detect populations with gene variants associated with AD are among the recommendations to improve the landscape of AD.

The (in)visible Brazilians: A perspective review on the need for brain health and dementia research with Brazilian immigrants in the United States

Introduction

The Brazilian population in the United States (U.S.), a Latinx subgroup, is rapidly growing and aging but remains underrepresented in U.S. health research. In addition to group-specific genetic and environmental risks, Brazilian immigrants and their offspring in the U.S. likely have cumulative risks for health inequities.It is estimated that 71% of Brazilian immigrants in the U.S. are undocumented, which may limit healthcare access/utilization. Furthermore, mental health is reported as a health priority by Brazilian immigrants in the U.S., and there is a lack of research on Alzheimer's disease and related dementia (AD/ADRD) in this population.

Methods

We reviewed the scientific literature using traditional (e.g., PubMed) sources and databases generated by U.S. and Brazilian governments, as well as international organizations, and press articles.

Results

This perspective review lists recommendations for researchers, health providers, and policymakers to promote greater inclusion of U.S. Brazilian populations in health research and care. The review identifies research areas in need of attention to address health inequities and promote mental/brain health in Brazilian immigrants and their offspring living in the U.S. These research areas are: 1) epidemiological studies to map the prevalence and incidence of mental/brain health conditions; 2) research on aging and AD/ADRD risk factors among Brazilian populations in the U.S.; and 3) the need for greater representation of U.S-residing Brazilian population in other relevant research areas involving genetics, neuropathology, and clinical trials.

Conclusions

The recommendation and research efforts proposed should help to pave the way for the development of community-engagement research and to promote mental/brain health education, improvement of mental/brain health and AD/ADRD services, and the development of culturally-informed intervention to the U.S.-residing Brazilian communities.

HIGHLIGHTS

The Brazilian population in the United States is growing but is underrepresented in U.S. health research.Approximately 71% of Brazilian immigrants in the United States are undocumented, with an increased risk for health inequities.Mental health is reported as a central health priority by Brazilian immigrants in the United States.There is a lack of research on Alzheimer's disease and other dementias (ADRD) in Brazilian immigrants in the United States.Epidemiological research is needed to map the prevalence/incidence of mental health conditions and ADRD risk factors among Brazilian immigrants in the United States.

A call for clinical trial globalization in Alzheimer's disease and related dementia

BACKGROUND

The burden of Alzheimer's disease and related dementia (ADRD) is projected to disproportionally impact low-middle-income countries (LMICs). However, there is a systematic under-representation of LMICs in ADRD clinical trial platforms.

METHODS

We aimed to determine the global distribution of ADRD clinical trials and identify existing barriers for conducting clinical trials in LMICs. Primary data sources to identify trial distribution in LMICs included ClinicalTrials.gov and the International Trials Registry Platform. An additional systematic review and expert consensus interviews were conducted to identify barriers for conducting clinical trials in LMICs.

FINDINGS

Among 1237 disease-modifying therapies tested in ADRD clinical trials, only 11.6% have been or are conducted in emerging economies (upper-middle income [9.6%] and low-middle income [2.0%]). We identified several limitations for trial implementation including a lack of financial resources, low industry presence, regulatory obstacles, and operational barriers INTERPRETATION: Although LMICs bear the greatest burden of ADRD globally, substantial development of clinical trial platforms to address this inequity and health disparity is lacking.

Literacy, but not memory, is associated with hippocampal connectivity in illiterate adults

Background

The influence of hippocampal connectivity on memory performance is well established in individuals with high educational attainment. However, the role of hippocampal connectivity in illiterate populations remains poorly understood.

Methods

Thirty-five illiterate adults were administered a literacy assessment (Test of Functional Health Literacy in Adults - TOFHLA), structural and resting state functional MRI and an episodic memory test (Free and Cued Selective Reminding Test). Illiteracy was defined as a TOFHLA score below 53. We evaluated the correlation between hippocampal connectivity at rest and both free recall and literacy scores.

Results

Participants were mostly female (57.1%) and Black (84.8%), with a median age of 50 years. The median TOFHLA literacy score was 28.0 [21.0;42.5] out of 100 points and the median free recall score was 30.0 [26.2;35] out of 48 points. The median gray matter volume of both the left and right hippocampi was 2.3 [2.1; 2.4] cm3. We observed a significant connectivity between both hippocampi and the precuneus and the ventral medial prefrontal cortex. Interestingly, the right hippocampal connectivity positively correlated with the literacy scores (β = 0.58, p = 0.008). There was no significant association between episodic memory and hippocampal connectivity. Neither memory nor literacy scores correlated with hippocampal gray matter volume.

Conclusions

Low literacy levels correlate with hippocampal connectivity in illiterate adults. The lack of association with memory scores might be associated with low brain reserve in illiterate adults.

Latin American women in dementia research: outstanding contributions, barriers, and opportunities from Argentinian, Chilean, and Colombian colleagues

Women's contributions to science have been consistently underrepresented throughout history. Despite many efforts and some progresses being made to reduce gender inequity in science, pursuing an academic career across disciplines, including Alzheimer's disease (AD) and other dementias, remains challenging for women. Idiosyncratic difficulties of Latin American countries likely accentuate the gender gap. In this Perspective, we celebrate outstanding contributions from Argentinian, Chilean, and Colombian colleagues in dementia research and discuss barriers and opportunities identified by them. We aim to acknowledge Latin American women's work and bring visibility to the challenges they face throughout their careers in order to inform potential solutions. Also, we highlight the need to perform a systematic assessment of the gender gap in the Latin American dementia community of researchers.

Gender inequalities as contributors to dementia in Latin America and the Caribbean: what factors are missing from research?

The current knowledge of modifiable risk factors for dementia comes mainly from high-income countries. In Latin America and Caribbean countries, where the burden of gender and socioeconomic inequalities is greater than in high-income countries, the prevalence of dementia is also higher and disease onset is earlier, especially among women, even after adjustments for life expectancy. In this Personal View, we discuss socioeconomic modifiable risk factors for dementia established by previous studies and postulate further harmful and often hidden factors faced by women that might influence the gender-specific timing of onset and general prevalence of dementia. We emphasise some of the effects of gender roles, their direct and indirect effects on dementia, and how they disproportionately impact women. Finally, we highlight the importance of bringing hidden risk factors to open discussion to promote research with high-quality data and to encourage public policies to promote and preserve women's health.