Public Health.

Background: Midlife vascular risk factors are associated with an increased risk of dementia. However, the overall contribution of modifiable vascular risk factors in midlife and late-life to dementia remains unclear. In this study, we quantified population attributable fractions, which account for risk factor prevalence and strength of relative risks, of incident dementia from vascular risk factors measured in midlife and early late-life.

Public Health.

Background: Impairments in sensory and motor function are common and have been independently linked with higher risk of dementia in older adults. Yet, there is limited information associated with the increasing number of such impairments and dementia risk. This study investigated longitudinal associations between sensory and motor impairment and dementia in older adults.

The added value of metadata on test completion time for the quantification of cognitive functioning in survey research.

Objective: Information on the time spent completing cognitive testing is often collected, but such data are not typically considered when quantifying cognition in large-scale community-based surveys. We sought to evaluate the added value of timing data over and above traditional cognitive scores for the measurement of cognition in older adults.

Method: We used data from the Longitudinal Aging Study in India-Diagnostic Assessment of Dementia (LASI-DAD) study ( = 4,091), to assess the added value of timing data over and above traditional cognitive scores, using item-specific regression models for 36 cognitive test items.

The potential impact of optimal blood pressure treatment intensity to reduce disparities in dementia between Black and White individuals.

Background: Black adults have higher dementia risk than White adults. Whether tighter population-level blood pressure (BP) control reduces this disparity is unknown.

Objective: Estimate the impact of optimal BP treatment intensity on racial disparities in dementia.

Exploring Cognitive and Neuroimaging Profiles of Dementia Subtypes of Individuals with Dementia in the Democratic Republic of Congo.

Objective: The 2024 Alzheimer's Association (AA) research diagnostic criteria for Alzheimer's Disease (AD) considers fluid biomarkers, including promising blood-based biomarkers for detecting AD. This study aims to identify dementia subtypes and their cognitive and neuroimaging profiles in older adults with dementia in the Democratic Republic of Congo (DRC) using biomarkers and clinical data.

Methods: Forty-five individuals with dementia over 65 years old were evaluated using the Community Screening Instrument for Dementia and the informant-based Alzheimer's Questionnaire.

Modifiable risk factors for dementia in India: A cross-sectional study revisiting estimates and reassessing prevention potential and priorities.

Background: About 16% of worldwide dementia cases are in India. Evaluating the prospects for dementia prevention in India requires knowledge of context-specific risk factors, as relationships between risk factors and dementia observed in high-income countries (HICs) may not apply.

Methods: We computed population attributable fractions (PAFs) for dementia in India by estimating associations between risk factors and dementia, their prevalence and communality, within the same nationally representative sample of 4,096 Indians aged 60 and older, surveyed through the Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD).

Cross-national statistical harmonization of the Center for Epidemiologic Studies Depression (CES-D) scale among older adults in China, England, India, Mexico, South Africa, and the United States.

Objectives: We examined differential item functioning (DIF) of the Center for Epidemiologic Studies Depression Scale (CES-D) items by country and statistically harmonized common cross-national factor scores for the CES-D to aid further cross-national research.

Study Design And Setting: Data were from Harmonized Cognitive Assessment Protocol (HCAP) studies in China (N = 9639), England (N = 1262), India (N = 4048), Mexico (N = 1918), South Africa (N = 631), and the United States (N = 3321). Multiple indicators, multiple causes models were estimated to test DIF in the CES-D items by country.

Preliminary reference values for Alzheimer's disease plasma biomarkers in Congolese individuals with and without dementia.

Background: Western countries have provided reference values (RV) for Alzheimer's disease (AD) plasma biomarkers, but there are not available in Sub-Saharan African populations.

Objective: We provide preliminary RV for AD and other plasma biomarkers including amyloid- (Aβ42/40), phosphorylated tau-181 and 217 (p-tau181, p-tau217), neurofilament light (Nfl), glial fibrillary acidic protein (GFAP), interleukin 1b and 10 (IL-1b and IL-10) and tumor necrosis factor (TNFα) in Congolese adults with and without dementia.

Methods: 85 adults (40 healthy and 45 dementia) over 50 years old were included.

Type II diabetes and cognitive function among older adults in India and China-results from Harmonized Cognitive Assessment Protocol studies.

Objective: Type II diabetes is a recognized risk factor of declining cognitive function in high-income countries. However, there is limited research on this association across low- and middle-income countries. We aimed to examine and compare the relationship between type II diabetes and cognition amongst adults aged 60 years and older for two of the largest LMICs: India and China.

Measurement Error and Methodologic Issues in Analyses of the Proportion of Variance Explained in Cognition.

Existing studies examining the predictive ability of biomarkers for cognitive outcomes do not account for variance due to measurement error, which could lead to under-estimates of the proportion of variance explained. We used data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) (N = 1084) to estimate the proportion of variance explained by Alzheimer's disease (AD) imaging biomarkers in four cognitive outcomes: memory, executive functioning, language, and visuospatial functioning. We compared estimates from standard models that do not account for measurement error, and multilevel models that do account for measurement error.

Evaluating Social Determinants of Health-Based Alternatives to Race-Based Cognitive Normative Models.

Background And Objectives: Race and ethnicity are proxy measures of sociocultural factors that influence cognitive test performance. Our objective was to compare different regression-based cognitive normative models adjusting for demographics and different combinations of easily accessible/commonly used social determinants of health (SDoH) factors, which may help describe cognitive performance variability historically captured by ethnoracial differences.

Methods: We performed cross-sectional analyses on data from Black and White participants without mild cognitive impairment/dementia in the Atherosclerosis Risk in Communities Study who attended visit 5 in 2011-2013.

Age differences in the change in cognition after stroke.

Objective: To compare changes in cognitive trajectories after stroke between younger (18-64) and older (65+) adults, accounting for pre-stroke cognitive trajectories.

Materials And Methods: Pooled cohort study using individual participant data from 3 US cohorts (1971-2019), the Atherosclerosis Risk In Communities Study (ARIC), Framingham Offspring Study (FOS), and REasons for Geographic And Racial Differences in Stroke Study (REGARDS). Linear mixed effect models evaluated the association between age and the initial change (intercept) and rate of change (slope) in cognition after compared to before stroke.

The Relationship Between 10-year Changes in Cognitive Ability and Subsequent Mortality: Findings from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) Trial.

Cognitive ability and cognitive decline are related to mortality in older adults. Cognitive interventions have been found to improve cognitive performance and slow cognitive decline in later life. However, the longitudinal effects of cognitive interventions on mortality in older adults remain unclear.

Neurodegenerative Plasma Biomarkers for Prediction of Hippocampal Atrophy in Older Adults with Suspected Alzheimer's Disease in Kinshasa, Democratic Republic of Congo.

Objective: The hippocampus is one of the first brain structures affected by Alzheimer's disease (AD), and its atrophy is a strong indicator of the disease. This study investigates the ability of plasma biomarkers of AD and AD-related dementias-amyloid-β (Aβ42/40), phosphorylated tau-181 (p-tau181), neurofilament light (NfL), and glial fibrillary acidic protein (GFAP)-to predict hippocampal atrophy in adult individuals in Kinshasa, Democratic Republic of Congo (DRC).

Methods: Eighty-five adult individuals (40 healthy and 45 suspected AD) over 65 years old were evaluated using the Community Screening Instrument for Dementia and Alzheimer's Questionnaire (AQ).

Preliminary reference values for Alzheimer's disease plasma biomarkers in Congolese individuals with and without Alzheimer's disease.

Background: Western countries have provided reference values (RV) for Alzheimer's disease (AD) plasma biomarkers, but there are not available in Sub-Saharan African populations.

Objective: We provide preliminary RV for AD and other plasma biomarkers including amyloid- β (Aβ42/40), phosphorylated tau-181 and 217 (p-tau181, p-tau217), neurofilament light (Nfl), glial fibrillary acidic protein (GFAP), interleukin 1b and 10 (IL-1b and IL-10) and tumor necrosis factor α (TNFα) in Congolese adults with and without dementia.

Methods: 85 adults (40 healthy and 45 dementia) over 50 years old were included.

Region-based analysis with functional annotation identifies genes associated with cognitive function in South Asians from India.

The prevalence of dementia among South Asians across India is approximately 7.4% in those 60 years and older, yet little is known about genetic risk factors for dementia in this population. Most known risk loci for Alzheimer's disease (AD) have been identified from studies conducted in European Ancestry (EA) but are unknown in South Asians.

How to distinguish promotion, prevention and treatment trials in public mental health? Study protocol for the development of the VErona-LUgano Tool (VELUT).

Introduction: Promoting mental health, preventing and treating mental disorders are critically important in public health, and many randomised controlled trials (RCTs) evaluate intervention strategies for these objectives. However, distinguishing promotion from prevention and from treatment RCTs is challenging. A tool to place studies along the promotion-to-treatment continuum in mental health research does not exist, leaving it to researchers and policymakers to decide on how to classify individual RCTs, which hinders evidence synthesis.

Development and assessment of analytic methods to improve the measurement of cognition in longitudinal studies of aging through the use of substudies with comprehensive neuropsychological testing.

Introduction: The Health and Retirement Study International Partner Surveys (HRS IPS) have rich longitudinal data, but the brevity of cognitive batteries is a limitation.

Methods: We used data from a substudy of the English Longitudinal Study of Ageing (ELSA) administering detailed cognitive assessments with the Harmonized Cognitive Assessment Protocol (ELSA-HCAP) (N = 1273) to inform approaches for estimating cognition in ELSA (N = 11,213). We compared two novel approaches: confirmatory factor analysis (CFA)- and regression-based prediction.

Could differential under-reporting of loneliness between men and women bias the gender-specific association between loneliness duration and rate of memory decline? A probabilistic bias analysis of effect modification.

Gender is an observed effect modifier of the association between loneliness and memory aging. However, this effect modification may be a result of information bias due to differential loneliness under-reporting by gender. We applied probabilistic bias analyses to examine whether effect modification of the loneliness-memory decline relationship by gender is retained under three simulation scenarios with various magnitudes of differential loneliness under-reporting between men and women.