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2.
Neurobiol Aging ; 144: 78-92, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39293163

RESUMEN

Alzheimer's Disease (AD) neuropathology start decades before clinical manifestations, but whether risk factors are associated with early cognitive and brain changes in midlife remains poorly understood. We examined whether AD risk factors were associated with cognition and functional connectivity (FC) between the Locus Coeruleus (LC) and hippocampus - two key brain structures in AD neuropathology - cross-sectionally and longitudinally in cognitively healthy midlife individuals. Neuropsychological assessments and functional Magnetic Resonance Imaging were obtained at baseline (N=210), and two-years follow-up (N=188). Associations of cognition and FC with apolipoprotein ε4 (APOE ε4) genotype, family history of dementia, and the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) score were investigated. Cross-sectionally, higher CAIDE scores were associated with worse cognition. Menopausal status interacted with the CAIDE risk on cognition. Furthermore, the CAIDE score significantly moderated the relationship between cognition and LC-Hippocampus FC. Longitudinally, the LC-Hippocampus FC decreased significantly over 2 years. These results suggest that cardiovascular risk of dementia is associated with brain-behaviour changes in cognitively healthy, middle-aged individuals.

3.
JAMA Netw Open ; 7(8): e2426774, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39145979

RESUMEN

Importance: Traumatic brain injuries (TBI) represent an important, potentially modifiable risk factor for dementia. Despite frequently observed vascular imaging changes in individuals with TBI, the relationships between TBI-associated changes in brain imaging and clinical outcomes have largely been overlooked in community cases of TBI. Objective: To assess whether TBI are associated with and interact with midlife changes in neuroimaging and clinical features in otherwise healthy individuals. Design, Setting, and Participants: This cross-sectional analysis used baseline data from the PREVENT Dementia program collected across 5 sites in the UK and Ireland between 2014 and 2020. Eligible participants were cognitively healthy midlife adults aged between 40 and 59 years. Data were analyzed between January 2023 and April 2024. Exposure: Lifetime TBI history was assessed using the Brain Injury Screening Questionnaire. Main Outcomes and Measures: Cerebral microbleeds and other markers of cerebral small vessel disease (white matter hyperintensities [WMH], lacunes, perivascular spaces) were assessed on 3T magnetic resonance imaging. Clinical measures were cognition, sleep, depression, gait, and cardiovascular disease (CVD) risk, assessed using Computerized Assessment of Information Processing (COGNITO), Pittsburgh Sleep Quality Index, Center for Epidemiologic Studies Depression Scale, clinical interviews, and the Framingham Risk Score, respectively. Results: Of 617 participants (median [IQR] age, 52 [47-56] years; 380 female [61.6%]), 223 (36.1%) had a history of TBI. TBI was associated with higher microbleed count (ß = 0.10; 95% CI, 0.01-0.18; P = .03), with a dose-response association observed with increasing number of TBI events (ß = 0.05; 95% CI, 0.01-0.09; P = .03). Conversely, TBI was not associated with other measures of small vessel disease, including WMH. Furthermore, TBI moderated microbleed associations with vascular risk factors and clinical outcomes, such that associations were present only in the absence of TBI. Importantly, observations held when analyses were restricted to individuals reporting only mild TBI. Conclusions and Relevance: In this cross-sectional study of healthy middle-aged adults, detectable changes in brain imaging and clinical features were associated with remote, even mild, TBI in the general population. The potential contribution of vascular injury to TBI-related neurodegeneration presents promising avenues to identify potential targets, with findings highlighting the need to reduce TBI through early intervention and prevention in both clinical care and policymaking.


Asunto(s)
Demencia , Neuroimagen , Humanos , Femenino , Persona de Mediana Edad , Estudios Transversales , Masculino , Demencia/diagnóstico por imagen , Neuroimagen/métodos , Adulto , Imagen por Resonancia Magnética/métodos , Irlanda/epidemiología , Reino Unido/epidemiología , Conmoción Encefálica/diagnóstico por imagen , Conmoción Encefálica/complicaciones , Factores de Riesgo , Lesiones Traumáticas del Encéfalo/diagnóstico por imagen , Lesiones Traumáticas del Encéfalo/complicaciones
4.
Alzheimers Dement ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39136296

RESUMEN

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.

5.
PLoS One ; 19(7): e0307418, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39037993

RESUMEN

Evidence syntheses for advancing equitable traumatic brain injury (TBI) research, policy, and practice presents formidable challenges. Research and clinical frameworks are currently not specific to equity, diversity, and inclusion considerations, despite evidence that persons with TBI live in societies in which power imbalances and systems of social dominance may privilege some people and marginalize others. The present protocol outlines a strategy for a research program, supported by the Canadian Institutes of Health Research, that explores the integration of PROGRESS-Plus parameters in research with the goal of advancing open-science databases and tools to improve our understanding of equity in cognitive and brain health outcomes in TBI. PROGRESS-Plus is a framework outlining social, economic, and cultural parameters that may influence health opportunities and outcomes (e.g., place of residence, race, occupation, gender, etc.). A multistep research program is proposed to support three objectives: (1) organizing existing data on TBI-induced changes in cognition and brain health into a template to facilitate future research, including research using machine learning techniques; (2) updating published evidence with a more rigorous approach to the consideration of PROGRESS-Plus parameters; and (3) mobilizing knowledge on the current state of evidence that is relevant, equitable, and accessible. This program facilitates partnerships with knowledge users across clinical, research, academic, and community sectors to address the three research objectives through a unifying workflow of exchange, synthesis, and knowledge mobilization. We anticipate that this global collaboration between topic experts and community leaders in equity in brain health will add significant value to the field of TBI by promoting equity-transformative advancements in knowledge synthesis, policy, and practice.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Cognición , Humanos , Lesiones Traumáticas del Encéfalo/terapia , Canadá/epidemiología , Equidad en Salud , Diversidad, Equidad e Inclusión
6.
Hum Brain Mapp ; 45(11): e26798, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39081128

RESUMEN

Brain atrophy and cortical thinning are typically observed in people with Alzheimer's disease (AD) and, to a lesser extent, in those with mild cognitive impairment. In asymptomatic middle-aged apolipoprotein ε4 (ΑPOE4) carriers, who are at higher risk of future AD, study reports are discordant with limited evidence of brain structural differences between carriers and non-carriers of the ε4 allele. Alternative imaging markers with higher sensitivity at the presymptomatic stage, ideally quantified using typically acquired structural MRI scans, would thus be of great benefit for the detection of early disease, disease monitoring and subject stratification. In the present cross-sectional study, we investigated textural properties of T1-weighted 3T MRI scans in relation to APOE4 genotype, age and sex. We pooled together data from the PREVENT-Dementia and ALFA studies focused on midlife healthy populations with dementia risk factors (analysable cohort: 1585 participants; mean age 56.2 ± 7.4 years). Voxel-based and texture (examined features: contrast, entropy, energy, homogeneity) based morphometry was used to identify areas of volumetric and textural differences between APOE4 carriers and non-carriers. Textural maps were generated and were subsequently harmonised using voxel-wise COMBAT. For all analyses, APOE4, sex, age and years of education were used as model predictors. Interactions between APOE4 and age were further examined. There were no group differences in regional brain volume or texture based on APOE4 carriership or when age × APOE4 interactions were examined. Older people tended to have a less homogeneous textural profile in grey and white matter and a more homogeneous profile in the ventricles. A more heterogeneous textural profile was observed for females in areas such as the ventricles, frontal and parietal lobes and for males in the brainstem, cerebellum, precuneus and cingulate. Overall, we have shown the absence of volumetric and textural differences between APOE4 carriers and non-carriers at midlife and have established associations of textural features with ageing and sex.


Asunto(s)
Envejecimiento , Apolipoproteína E4 , Imagen por Resonancia Magnética , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Envejecimiento/patología , Envejecimiento/genética , Apolipoproteína E4/genética , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Estudios Transversales , Genotipo , Heterocigoto , Caracteres Sexuales
7.
Geroscience ; 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39085534

RESUMEN

INTRODUCTION: Systemic inflammation and endothelial dysfunction are potentially modifiable factors implicated in Alzheimer's disease (AD), which offer potential therapeutic targets to slow disease progression. METHODS: We investigated the relationship between baseline circulating levels of inflammatory (TNF-α, IL-1ß) and endothelial cell markers (VCAM-1, ICAM-1, E-selectin) and 18-month cognitive decline (ADAS-cog12) in 266 mild-to-moderate AD patients from the NILVAD study. We employed individual growth models to examine associations, potential mediation, and interaction effects while adjusting for confounders. RESULTS: The average increase in ADAS-cog12 scores over all patients was 8.1 points in 18 months. No significant association was found between the markers and the rate of cognitive decline. Mediation analysis revealed no mediating role for endothelial cell markers, and interaction effects were not observed. DISCUSSION: Our results do not support the role of systemic inflammation or endothelial dysfunction in progression in persons with AD.

8.
Nat Aging ; 4(8): 1153-1165, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38886210

RESUMEN

Models of healthy aging are typically based on the United States and Europe and may not apply to diverse and heterogeneous populations. In this study, our objectives were to conduct a meta-analysis to assess risk factors of cognition and functional ability across aging populations in Latin America and a scoping review focusing on methodological procedures. Our study design included randomized controlled trials and cohort, case-control and cross-sectional studies using multiple databases, including MEDLINE, the Virtual Health Library and Web of Science. From an initial pool of 455 studies, our meta-analysis included 38 final studies (28 assessing cognition and 10 assessing functional ability, n = 146,000 participants). Our results revealed significant but heterogeneous effects for cognition (odds ratio (OR) = 1.20, P = 0.03, confidence interval (CI) = (1.0127, 1.42); heterogeneity: I2 = 92.1%, CI = (89.8%, 94%)) and functional ability (OR = 1.20, P = 0.01, CI = (1.04, 1.39); I2 = 93.1%, CI = (89.3%, 95.5%)). Specific risk factors had limited effects, especially on functional ability, with moderate impacts for demographics and mental health and marginal effects for health status and social determinants of health. Methodological issues, such as outliers, inter-country differences and publication bias, influenced the results. Overall, we highlight the specific profile of risk factors associated with healthy aging in Latin America. The heterogeneity in results and methodological approaches in studying healthy aging call for greater harmonization and further regional research to understand healthy aging in Latin America.


Asunto(s)
Cognición , Envejecimiento Saludable , Humanos , América Latina/epidemiología , Factores de Riesgo , Cognición/fisiología , Anciano , Masculino , Femenino
9.
Artículo en Inglés | MEDLINE | ID: mdl-38899837

RESUMEN

BACKGROUND: Speech and language therapists (SLTs) play an important role in assessing and rehabilitating communication disorders in people with dementia, but there is evidence to suggest that they do not receive appropriate training to provide management and support during their training. AIM: To investigate the level of awareness and knowledge that practising SLTs from Brazil have about dementia and their role in the care of dementia through an online survey. METHODS & PROCEDURES: An online survey tool was developed to collect information from practising Brazilian SLTs regarding their knowledge about dementia, awareness about their role in the care of people with dementia, and opinions on how SLTs may be better prepared to work in the dementia field. The survey was disseminated via social media, websites, and e-mail lists of researchers and stakeholders. OUTCOMES & RESULTS: A total of 227 SLTs completed the survey. Participants showed good knowledge of dementia in general, while their answers were less accurate on primary progressive aphasia. Regarding the awareness by SLTs of their role in the care of people with dementia, most agreed or strongly agreed that SLTs could help people in the diagnosis, treatment and prevention of dementia (> 80%). However, fewer participants agreed or strongly agreed that they felt confident in contributing to the treatment and diagnosis process of dementia (about 50%). To improve the training of SLTs in Brazil, most participants believed that it would be necessary to improve the teaching of dementia at the undergraduate speech and language therapy curriculum level and to develop recommendations or guidelines about speech and language therapy practice in dementia. CONCLUSIONS & IMPLICATIONS: The results of this survey point to a need for improvement in the knowledge and confidence of Brazilian SLTs about dementia. To reach this goal, targeted training courses and applied practice opportunities should be embedded within university curricula and training programmes. WHAT THIS PAPER ADDS: What is already known on the subject Many studies confirm the importance of speech and language therapy in the non-pharmacological treatment of people with dementia. However, other evidence suggests to a possible lack of training for Brazilian SLTs, especially in the curriculum of undergraduate courses. What this paper adds to existing knowledge This study reveals that Brazilian SLTs have substantial knowledge of dementia and recognize the significance of their role in treating people with dementia. However, a minority expressed confidence in their ability to assess and treat people with dementia. What are the potential or actual clinical implications of this work? The findings of this research demonstrate that Brazilian SLTs have good knowledge of dementia and endorse their professional role in dementia care; however, they lack confidence in their own skills and expertise in diagnostic assessment and treatment of dementia. Interventions aimed at boosting the SLT's confidence level could lead to improved patients outcomes and overall quality of care within clinical settings.

10.
Healthcare (Basel) ; 12(11)2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38891208

RESUMEN

There is growing evidence on the prevalence and impact of loneliness, particularly among older people. However, much less is known about the personal origins of loneliness and how it persists, or not, over an individual's life course. This study aimed to increase understanding of the personal experiences of loneliness among older adults across the life course. Central to this study was giving voice to the participants and allowing them to define loneliness, what it meant to them, and how it affected them throughout their lives. This qualitative study employed 18 life story interviews with older adults attending a mental health service. We explored their personal experiences of loneliness and the situations and factors associated with loneliness across the life course. We identified three distinct typologies of loneliness: those who experienced (1) chronic loneliness since childhood, (2) chronic loneliness after a life-changing event in midlife, and (3) loneliness which remained situational/transitional, never becoming chronic. This study found the seeds of chronic life course loneliness are often determined in childhood. Early detection and intervention may prevent situational loneliness from becoming chronic. More research is needed from a life course approach to help understand and address the causes and consequences of loneliness.

11.
Brain Commun ; 6(3): fcae189, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38863576

RESUMEN

PREVENT is a multi-centre prospective cohort study in the UK and Ireland that aims to examine midlife risk factors for dementia and identify and describe the earliest indices of disease development. The PREVENT dementia programme is one of the original epidemiological initiatives targeting midlife as a critical window for intervention in neurodegenerative conditions. This paper provides an overview of the study protocol and presents the first summary results from the initial baseline data to describe the cohort. Participants in the PREVENT cohort provide demographic data, biological samples (blood, saliva, urine and optional cerebrospinal fluid), lifestyle and psychological questionnaires, undergo a comprehensive cognitive test battery and are imaged using multi-modal 3-T MRI scanning, with both structural and functional sequences. The PREVENT cohort governance structure is described, which includes a steering committee, a scientific advisory board and core patient and public involvement groups. A number of sub-studies that supplement the main PREVENT cohort are also described. The PREVENT cohort baseline data include 700 participants recruited between 2014 and 2020 across five sites in the UK and Ireland (Cambridge, Dublin, Edinburgh, London and Oxford). At baseline, participants had a mean age of 51.2 years (range 40-59, SD ± 5.47), with the majority female (n = 433, 61.9%). There was a near equal distribution of participants with and without a parental history of dementia (51.4% versus 48.6%) and a relatively high prevalence of APOEɛ4 carriers (n = 264, 38.0%). Participants were highly educated (16.7 ± 3.44 years of education), were mainly of European Ancestry (n = 672, 95.9%) and were cognitively healthy as measured by the Addenbrookes Cognitive Examination-III (total score 95.6 ± 4.06). Mean white matter hyperintensity volume at recruitment was 2.26 ± 2.77 ml (median = 1.39 ml), with hippocampal volume being 8.15 ± 0.79 ml. There was good representation of known dementia risk factors in the cohort. The PREVENT cohort offers a novel data set to explore midlife risk factors and early signs of neurodegenerative disease. Data are available open access at no cost via the Alzheimer's Disease Data Initiative platform and Dementia Platforms UK platform pending approval of the data access request from the PREVENT steering group committee.

12.
Brain Commun ; 6(3): fcae138, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38779354

RESUMEN

Changes in the brain's physiology in Alzheimer's disease are thought to occur early in the disease's trajectory. In this study our aim was to investigate the brain's neurochemical profile in a midlife cohort in relation to risk factors for future dementia using single voxel proton magnetic resonance spectroscopy. Participants in the multi-site PREVENT-Dementia study (age range 40-59 year old) underwent 3T magnetic resonance spectroscopy with the spectroscopy voxel placed in the posterior cingulate/precuneus region. Using LCModel, we quantified the absolute concentrations of myo-inositol, total N-acetylaspartate, total creatine, choline, glutathione and glutamate-glutamine for 406 participants (mean age 51.1; 65.3% female). Underlying partial volume effects were accounted for by applying a correction for the presence of cerebrospinal fluid in the magnetic resonance spectroscopy voxel. We investigated how metabolite concentrations related to apolipoprotein ɛ4 genotype, dementia family history, a risk score (Cardiovascular Risk Factors, Aging and Incidence of Dementia -CAIDE) for future dementia including non-modifiable and potentially-modifiable factors and dietary patterns (adherence to Mediterranean diet). Dementia family history was associated with decreased total N-acetylaspartate and no differences were found between apolipoprotein ɛ4 carriers and non-carriers. A higher Cardiovascular Risk Factors, Aging, and Incidence of Dementia score related to higher myo-inositol, choline, total creatine and glutamate-glutamine, an effect which was mainly driven by older age and a higher body mass index. Greater adherence to the Mediterranean diet was associated with lower choline, myo-inositol and total creatine; these effects did not survive correction for multiple comparisons. The observed associations suggest that at midlife the brain demonstrates subtle neurochemical changes in relation to both inherited and potentially modifiable risk factors for future dementia.

13.
Neurosci Biobehav Rev ; 162: 105697, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38710422

RESUMEN

The lifespan is influenced by adverse childhood experiences that create predispositions to poor health outcomes. Here we propose an allostatic framework of childhood experiences and their impact on health across the lifespan, focusing on Latin American and Caribbean countries. This region is marked by significant social and health inequalities nested in environmental and social stressors, such as exposure to pollution, violence, and nutritional deficiencies, which critically influence current and later-life health outcomes. We review several manifestations across cognition, behavior, and the body, observed at the psychological (e.g., cognitive, socioemotional, and behavioral dysfunctions), brain (e.g., alteration of the development, structure, and function of the brain), and physiological levels (e.g., dysregulation of the body systems and damage to organs). To address the complexity of the interactions between environmental and health-related factors, we present an allostatic framework regarding the cumulative burden of environmental stressors on physiological systems (e.g., cardiovascular, metabolic, immune, and neuroendocrine) related to health across the life course. Lastly, we explore the relevance of this allostatic integrative approach in informing regional interventions and public policy recommendations. We also propose a research agenda, potentially providing detailed profiling and personalized care by assessing the social and environmental conditions. This framework could facilitate the delivery of evidence-based interventions and informed childhood-centered policy-making.


Asunto(s)
Alostasis , Humanos , Alostasis/fisiología , América Latina/epidemiología , Experiencias Adversas de la Infancia , Estrés Psicológico
14.
J Nutr Health Aging ; 28(5): 100246, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38669857

RESUMEN

The global increase in the population of older persons has profound inter-sectoral implications, necessitating the development of age-friendly initiatives at the global and national levels. While progress has been relatively slower across Sub-Saharan African countries, highlighting existing commendable initiatives is essential to identify the current gaps and promote the development of strategies and interventions to promote age-friendly societies. This mini-review highlights some of the key initiatives in Ghana in the areas of policy, healthcare, finance, social services, education and research and in promoting dementia-friendly communities.


Asunto(s)
Demencia , Humanos , Ghana , Anciano , Envejecimiento , Promoción de la Salud , Política de Salud , Servicio Social , Anciano de 80 o más Años
15.
Brain Commun ; 6(2): fcae046, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38444908

RESUMEN

A reduction in the volume of the thalamus and its nuclei has been reported in Alzheimer's disease, mild cognitive impairment and asymptomatic individuals with risk factors for early-onset Alzheimer's disease. Some studies have reported thalamic atrophy to occur prior to hippocampal atrophy, suggesting thalamic pathology may be an early sign of cognitive decline. We aimed to investigate volumetric differences in thalamic nuclei in middle-aged, cognitively unimpaired people with respect to dementia family history and apolipoprotein ε4 allele carriership and the relationship with cognition. Seven hundred participants aged 40-59 years were recruited into the PREVENT Dementia study. Individuals were stratified according to dementia risk (approximately half with and without parental dementia history). The subnuclei of the thalamus of 645 participants were segmented on T1-weighted 3 T MRI scans using FreeSurfer 7.1.0. Thalamic nuclei were grouped into six regions: (i) anterior, (ii) lateral, (iii) ventral, (iv) intralaminar, (v) medial and (vi) posterior. Cognitive performance was evaluated using the computerized assessment of the information-processing battery. Robust linear regression was used to analyse differences in thalamic nuclei volumes and their association with cognitive performance, with age, sex, total intracranial volume and years of education as covariates and false discovery rate correction for multiple comparisons. We did not find significant volumetric differences in the thalamus or its subregions, which survived false discovery rate correction, with respect to first-degree family history of dementia or apolipoprotein ε4 allele status. Greater age was associated with smaller volumes of thalamic subregions, except for the medial thalamus, but only in those without a dementia family history. A larger volume of the mediodorsal medial nucleus (Pfalse discovery rate = 0.019) was associated with a faster processing speed in those without a dementia family history. Larger volumes of the thalamus (P = 0.016) and posterior thalamus (Pfalse discovery rate = 0.022) were associated with significantly worse performance in the immediate recall test in apolipoprotein ε4 allele carriers. We did not find significant volumetric differences in thalamic subregions in relation to dementia risk but did identify an interaction between dementia family history and age. Larger medial thalamic nuclei may exert a protective effect on cognitive performance in individuals without a dementia family history but have little effect on those with a dementia family history. Larger volumes of posterior thalamic nuclei were associated with worse recall in apolipoprotein ε4 carriers. Our results could represent initial dysregulation in the disease process; further study is needed with functional imaging and longitudinal analysis.

16.
J Health Psychol ; : 13591053241235846, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38439512

RESUMEN

Befriending services are often delivered to older adults with a view to improving social connectedness, but they may also lead to improved health. The objective of the current study was to explore potential mechanisms through which befriending services might impact the health of older adults. Data were collected from 13 befriendee-befriender dyads (n = 26), using a constructivist grounded theory and dyadic analytic approach. Potential mechanisms were described, using a realist evaluative framework of mechanistic processes in a complex intervention context. Five mechanisms of action triggered by the intervention were identified: supporting health behaviours; providing emotional support; improving mood; getting cognitive stimulation and novelty; and providing opportunities for socialising. We identified five potential mechanisms through which befriending services might impact health for older people. Our results suggest potential mechanisms through which befriending might positively impact the health of older people, and which should be evaluated empirically in future research.

17.
Brain Commun ; 6(1): fcad351, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38384997

RESUMEN

The apolipoprotein E ɛ4 allele is the primary genetic risk factor for the sporadic type of Alzheimer's disease. However, the mechanisms by which apolipoprotein E ɛ4 are associated with neurodegeneration are still poorly understood. We applied the Neurite Orientation Dispersion Model to characterize the effects of apolipoprotein ɛ4 and its interactions with age and education on cortical microstructure in cognitively normal individuals. Data from 1954 participants were included from the PREVENT-Dementia and ALFA (ALzheimer and FAmilies) studies (mean age = 57, 1197 non-carriers and 757 apolipoprotein E ɛ4 carriers). Structural MRI datasets were processed with FreeSurfer v7.2. The Microstructure Diffusion Toolbox was used to derive Orientation Dispersion Index maps from diffusion MRI datasets. Primary analyses were focused on (i) the main effects of apolipoprotein E ɛ4, and (ii) the interactions of apolipoprotein E ɛ4 with age and education on lobar and vertex-wise Orientation Dispersion Index and implemented using Permutation Analysis of Linear Models. There were apolipoprotein E ɛ4 × age interactions in the temporo-parietal and frontal lobes, indicating steeper age-dependent Orientation Dispersion Index changes in apolipoprotein E ɛ4 carriers. Steeper age-related Orientation Dispersion Index declines were observed among apolipoprotein E ɛ4 carriers with lower years of education. We demonstrated that apolipoprotein E ɛ4 worsened age-related Orientation Dispersion Index decreases in brain regions typically associated with atrophy patterns of Alzheimer's disease. This finding also suggests that apolipoprotein E ɛ4 may hasten the onset age of dementia by accelerating age-dependent reductions in cortical Orientation Dispersion Index.

18.
Eur Geriatr Med ; 15(2): 527-537, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38168729

RESUMEN

PURPOSE: Antipsychotic use in Alzheimer disease (AD) is associated with adverse events and mortality. Whilst postulated to cause/exacerbate orthostatic hypotension (OH), the exact relationship between antipsychotic use and OH has never been explored in AD-a group who are particularly vulnerable to neuro-cardiovascular instability and adverse effects of medication on orthostatic blood pressure (BP) behaviour. METHODS: We analysed longitudinal data from an 18-month trial of Nilvadipine in mild-moderate AD. We assessed the effect of long-term antipsychotic use (for the entire 18-month study duration) on orthostatic BP phenotypes measured on eight occasions, in addition to the relationship between antipsychotic use, BP phenotypes and incident falls. RESULTS: Of 509 older adults with AD (aged 72.9 ± 8.3 years, 61.9% female), 10.6% (n = 54) were prescribed a long-term antipsychotic. Over 18 months, long-term antipsychotic use was associated with a greater likelihood of experiencing sit-to-stand OH (ssOH) (OR: 1.21; 1.05-1.38, p = 0.009) which persisted on covariate adjustment. Following adjustment for important clinical confounders, both antipsychotic use (IRR: 1.80, 1.11-2.92, p = 0.018) and ssOH (IRR: 1.44, 1.00-2.06, p = 0.048) were associated with a greater risk of falls/syncope over 18 months in older adults with mild-moderate AD. CONCLUSION: Even in mild-to-moderate AD, long-term antipsychotic use was associated with ssOH. Both antipsychotic use and ssOH were associated with a greater risk of incident falls/syncope over 18 months. Further attention to optimal prescribing interventions in this cohort is warranted and may involve screening older adults with AD prescribed antipsychotics for both orthostatic symptoms and falls.


Asunto(s)
Enfermedad de Alzheimer , Antipsicóticos , Hipotensión Ortostática , Anciano , Femenino , Humanos , Masculino , Accidentes por Caídas/prevención & control , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/epidemiología , Antipsicóticos/efectos adversos , Hipotensión Ortostática/tratamiento farmacológico , Hipotensión Ortostática/epidemiología , Hipotensión Ortostática/complicaciones , Síncope/complicaciones , Anciano de 80 o más Años
19.
Sci Rep ; 14(1): 573, 2024 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-38177228

RESUMEN

To date, there is a considerable heterogeneity of methods to score Allostatic Load (AL). Here we propose a comprehensive algorithm (ALCS) that integrates commonly used approaches to generate AL risk categories and assess associations to brain structure deterioration. In a cohort of cognitively normal mid-life adults (n = 620, age 51.3 ± 5.48 years), we developed a comprehensive composite for AL scoring incorporating gender and age differences, high quartile approach, clinical reference values, and current medications, to then generate AL risk categories. Compared to the empirical approach (ALES), ALCS showed better model fit criteria and a strong association with age and sex. ALSC categories were regressed against brain and white matter hyperintensity (WMH) volumes. Higher AL risk categories were associated with increased total, periventricular, frontal, and left parietal WMH volumes, also showing better fit compared to ALES. When cardiovascular biomarkers were removed from the ALSC algorithm, only left-frontal WMHV remained associated with AL, revealing a strong vascular burden influencing the index. Our results agree with previous evidence and suggest that sustained stress exposure enhances brain deterioration in mid-life adults. Showing better fit than ALES, our comprehensive algorithm can provide a more accurate AL estimation to explore how stress exposure enhances age-related health decline.


Asunto(s)
Alostasis , Sustancia Blanca , Adulto , Humanos , Persona de Mediana Edad , Sustancia Blanca/diagnóstico por imagen , Encéfalo , Imagen por Resonancia Magnética
20.
Aging Ment Health ; 28(8): 1162-1168, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38192062

RESUMEN

OBJECTIVES: The relationship between social isolation, loneliness, and tooth loss and cognition in older people is poorly understood. We examine how social isolation and cognitive performance are associated prospectively among older adults, as well as how tooth loss and loneliness are related to this association. METHODS: Using data from 26,168 participants aged ≥50 from the Survey of Health, Ageing and Retirement in Europe (SHARE), we explored the association between social isolation, loneliness, tooth loss and cognition. We used bootstrapping with resampling strategies for testing a moderated mediating model. RESULTS: Higher social isolation was associated with poorer cognitive performance (B = -0.20, 95% CI = -0.03, -0.01; R2 =0.60), an association mediated by the respondent's number of missing teeth (B = -0.001, 95% CI = -0.002, -0.001). Higher levels of social isolation were associated with a greater number of missing teeth, and a higher number of missing teeth was linked with poorer cognition. We also found that loneliness moderated the relationship between social isolation and both the number of missing teeth (B = -0.11, p = 0.047) and cognitive performance. CONCLUSION: In later life, social isolation and loneliness are associated with shoddy oral health and poor cognitive status. Clinicians and policymakers should be aware of both the association between social isolation and feelings of loneliness on dentition and oral health and their relationship to the cognitive status of older adults.


Asunto(s)
Soledad , Salud Bucal , Aislamiento Social , Pérdida de Diente , Humanos , Soledad/psicología , Anciano , Masculino , Aislamiento Social/psicología , Femenino , Europa (Continente) , Salud Bucal/estadística & datos numéricos , Pérdida de Diente/psicología , Pérdida de Diente/epidemiología , Persona de Mediana Edad , Anciano de 80 o más Años , Estudios Prospectivos , Cognición , Envejecimiento/psicología , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/psicología
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