Brain clocks capture diversity and disparities in aging and dementia

Brain clocks, which quantify discrepancies between brain age and chronological age, hold promise for understanding brain health and disease. However, the impact of diversity (including geographical, socioeconomic, sociodemographic, sex and neurodegeneration) on the brain-age gap is unknown. We analyzed datasets from 5,306 participants across 15 countries (7 Latin American and Caribbean countries (LAC) and 8 non-LAC countries). Based on higher-order interactions, we developed a brain-age gap deep learning architecture for functional magnetic resonance imaging (2,953) and electroencephalography (2,353). The datasets comprised healthy controls and individuals with mild cognitive impairment, Alzheimer disease and behavioral variant frontotemporal dementia. LAC models evidenced older brain ages (functional magnetic resonance imaging: mean directional error = 5.60, root mean square error (r.m.s.e.) = 11.91; electroencephalography: mean directional error = 5.34, r.m.s.e. = 9.82) associated with frontoposterior networks compared with non-LAC models. Structural socioeconomic inequality, pollution and health disparities were influential predictors of increased brain-age gaps, especially in LAC (R² = 0.37, F² = 0.59, r.m.s.e. = 6.9). An ascending brain-age gap from healthy controls to mild cognitive impairment to Alzheimer disease was found. In LAC, we observed larger brain-age gaps in females in control and Alzheimer disease groups compared with the respective males. The results were not explained by variations in signal quality, demographics or acquisition methods. These findings provide a quantitative framework capturing the diversity of accelerated brain aging.</p

Brain clocks capture diversity and disparities in aging and dementia across geographically diverse populations

Peer reviewe

Dementia in Latin America : paving the way towards a regional action plan

Regional challenges faced by Latin American and Caribbean countries (LACs) to fight dementia, such as heterogeneity, diversity, political instabilities, and socioeconomic disparities, can be addressed more effectively grounded in a collaborative setting based on the open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidence-based strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking and translational research) and align them to current global strategies to translate regional knowledge into actions with transformative power. Then, by characterizing genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions and mapping these to the above challenges, we provide the basic mosaics of knowledge that will pave the way towards a KtAF. We describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF

Staying in a Burning House: Perks and Perils of a Hotline in the Times of COVID‐19

International audienc

Characterization of data-driven geriatric syndrome clusters in older people with HIV: a Mexican multicenter cross-sectional studyResearch in context

Summary: Background: As living with HIV has been proposed as a condition that may accelerate aging, the main objective of this work was to estimate the prevalence of geriatric syndromes (GS) among older Mexicans with HIV dwelling in the community. Secondly, to evaluate whether the accumulation of GS could be associated with an adverse HIV-related clinical profile, independent of chronological age. Methods: Multicenter, cross-sectional study including 501 community-dwelling people aged ≥50 years with HIV. The overall prevalence of nine selected GS and their cumulative number were estimated. An Age-Independent Cumulative Geriatric Syndromes scale (AICGSs) was constructed, and correlations between the AICGSs and HIV-related parameters assessed. Finally, k-mean clustering analyses were performed to test the secondary objective. Findings: Median age 56 (IQR: 53–61) years, 81.6% of men. Polypharmacy (74.8%), sensorial deficit (71.2%), cognitive impairment (53.6%), physical disability (41.9%), pre-frailty (27.9%), and falls (29.7%), were the more prevalent GS. A significant negative correlation was found between the AICGSs and normalized values of CD4+ nadir cell counts (r = −0.126; 95%: CI: −0.223 to −0.026, p < 0.05). Similarly, a significant inverse adjusted association between the CD4+ nadir cells and the AICGSs was observed on linear regression analysis (β −0.058; 95%: CI: −0.109 to −0.007, p = 0.03). Cluster analysis identified three differentiated groups varying by age, metabolic comorbidities, AICGSs, and HIV-related parameters. Interpretation: An elevated prevalence of GS was observed in the studied population. Moreover, the accumulation of GS was associated with adverse HIV-related profiles, independent of age. Thus, early detection and management of GS are crucial to promote healthier aging trajectories in people with HIV. Funding: This work was funded in part by the National Center for the Prevention and Control of HIV/AIDS in Mexico (CENSIDA)—National Ministry of Health

Frailty among community-dwelling elderly people in france: the three-city study.

International audienceBACKGROUND: To better understand the contribution of frailty to health-related outcomes in elderly persons, it seems valuable to explore data from cohort studies across the world in an attempt to establish a comprehensive definition. The purpose of this report is to show the characteristics of frailty and observe its prognosis in a large sample of French community-dwelling elderly persons. METHODS: We used data from 6078 persons 65 years old or older participating in the Three-City Study (3C). Frailty was defined as having at least three of the following criteria: weight loss, weakness, exhaustion, slowness, and low activity. Principal outcomes were incident disability, hospitalization, and death. Multiple covariates were used to test the predictive validity of frailty on these outcomes. RESULTS: Four hundred twenty-six individuals (7%) met frailty criteria. Participants classified as frail were significantly older, more likely to be female, and less educated and reported more chronic diseases, lower income, and poorer self-reported health status in comparison to nonfrail participants. In multivariate analysis, frailty was significantly associated with 4-year incidence of disability in activities of daily living (ADL) and instrumental ADL. However, frailty was marginally associated with incident hospitalization and was not a statistically significant predictor of incident mobility disability or mortality adjusting for potential confounding factors. CONCLUSIONS: Frailty is not specific to a subgroup or region of the world. The construct proposed by Fried and colleagues confirms its predictive validity for adverse-health outcomes, particularly for certain components of disability, thus suggesting that it may be useful in population screening and predicting service needs

Prevalence and Co-Occurrence of Geriatric Syndromes in People Aged 75 Years and Older in France: Results From the Bordeaux Three-city Study

BACKGROUND: Geriatric syndromes (GSs) are often the result of cumulative insults to multiple organ systems and are considered common in older adults. However, their frequency and co-occurrence are not well known in the elderly population. This study aimed to determine the prevalence of several GSs and to analyze the co-occurrence of these syndromes in a general population of elderly individuals. METHODS: A cross-sectional analysis of 630 adults aged 75 years or older participating in the 10-year follow-up of the Bordeaux sample of the French Three-City Study was conducted. The following 10 GSs were assessed: physical frailty, dementia and cognitive impairment, depressive symptoms, polymedication, social isolation, thinness, falls, dependence, sensory deficit, and incontinence. The prevalence of the 10 GSs was estimated, and multiple correspondence analysis (MCA) models were used to explore the mutual associations between these GSs. RESULTS: The mean age of the participants was 83.3 years; 69% were women, and 80.5% [95% confidence interval (CI) = 76.3–82.7] had at least one GS. The most frequent GSs were polymedication (50.6% 95%CI = 46.7–54.5) and falls (43.1% 95%CI = 38.4–46.1). The MCA models identified two major dimensions of the 10 GSs: “Dementia–Dependence–Incontinence” and “Frailty–Depression–Isolation.” CONCLUSION: GSs were very common in this French elderly population and were grouped into two major dimensions: the “Dementia–Dependence–Incontinence” and “Frailty–Depression–Isolation.