Slower Rate Of Cognitive Decline Research Articles

Sex differences in cognitive decline among middle-aged and older adults: a cohort study in Europe.

Previous studies on sex differences in cognitive decline provide inconsistent findings, with many European countries being underrepresented. We determined the association between sex and cognitive decline in a sample of Europeans and explored differences across birth cohorts and regions. Participants 50+ years old enrolled in the Survey of Health, Ageing and Retirement in Europe had their cognition measured by tests of immediate recall, delayed recall and verbal fluency biennially up to 17years of follow-up (median 6, interquartile range 3-9years). We used linear mixed-effects models to assess the relationship between sex and the rate of cognitive decline, adjusting for sociodemographic and health-related characteristics. Of 66,670 participants (mean baseline age 63.5 ± standard deviation 9.4), 55% were female. Males and females had similar rates of decline in the whole sample in immediate recall (beta for interaction sex × time B = 0.002, 95% CI -0.001 to 0.006), delayed recall (B = 0.000, 95% CI -0.004 to 0.004), and verbal fluency (B = 0.008, 95% CI -0.005 to 0.020). Females born before World War II had a faster rate of decline in immediate recall and delayed recall compared to males, while females born during or after World War II had a slower rate of decline in immediate recall. Females in Central and Eastern Europe had a slower rate of cognitive decline in delayed recall compared to males. Our study does not provide strong evidence of sex differences in cognitive decline among older Europeans. However, we identified heterogeneity across birth cohorts and regions.

Effects of Bilingualism on Cognitive Processing

Purpose: The general purpose of the study was to examine the effects of bilingualism on cognitive processing.
 Methodology: The study adopted a desktop research methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library.
 Findings: The findings reveal that there exists a contextual and methodological gap relating to the effects of bilingualism on cognitive processing. Preliminary empirical review revealed that bilingualism is associated with cognitive advantages, such as enhanced attentional control, executive function, and working memory capacity. Through a review of existing literature, it was found that bilingual individuals often outperform monolinguals in cognitive tasks, supporting the Bilingual Advantage Theory. Additionally, evidence suggested that bilingualism may contribute to a slower rate of cognitive decline in older age. These findings have implications for educators, policymakers, and healthcare professionals, highlighting the potential benefits of promoting bilingual education and language preservation efforts.
 Unique Contribution to Theory, Practice and Policy: The Bilingual Advantage theory, Neuroplasticity and Cognitive Reserve theory may be used to anchor future studies on bilingualism and cognitive processing. The study made significant contributions to theory, practice, and policy. It supported the Bilingual Advantage Theory by demonstrating enhanced cognitive processing abilities in bilingual individuals. Recommendations included further exploration of underlying mechanisms, tailored interventions in educational and clinical settings, and policies supporting bilingual education and language diversity. These findings and recommendations aimed to advance understanding of bilingualism's cognitive benefits, inform practice in education and healthcare, and influence policy development for promoting linguistic diversity and cognitive development.

The Role of Smoking, Obesity, and Physical Inactivity in Cognitive Performance and Decline: A Multicohort Study.

Unhealthy lifestyles are recognized contributors to cognitive decline, yet limited evidence focuses on their roles in cognitive decline rate. This study examined the role of smoking, obesity, and physical inactivity in cognitive performance and rate of cognitive decline by birth cohort on a global scale. Utilizing data from 4 prospective cohort studies (China Health and Retirement Longitudinal Study, English Longitudinal Study on Ageing, Health and Retirement Study, and Survey of Health, Ageing and Retirement in Europe) across 14 countries, a multicohort study was performed. Eligible participants were aged 50 years and older. Linear mixed models were employed to detect the role of smoking, obesity, and physical inactivity in cognitive function domains (epidemic memory, working memory, and time orientation). Higher scores of cognitive functions were found in participants who engaged in more vigorous physical activity, were noncurrent smokers, and maintained underweight (eg, for episodic memory scores in females at 60 years, vigorous physical activity: 0.47, 95% CI: 0.46, 0.49). In addition, a slower rate of cognitive decline was also found in individuals who engaged in moderate or vigorous physical activity, were noncurrent smokers, and maintained not being underweight (eg, for episodic memory scores changing from 50 to 70 years old in females, vigorous physical activity: from 0.54 (95% CI: 0.51, 0.57) to 0.40 (95% CI: 0.37, 0.44) and in males from 0.33 (95% CI: 0.30, 0.36) to 0.11 (95% CI: 0.08, 0.14). We confirmed the beneficial impact of healthy lifestyles in preventing cognitive decline and promoting healthy aging. Urgent measures are needed to identify and encourage healthy lifestyles, such as strengthening tobacco control, developing policy on physical activity promotion, and preventing underweight, to minimize worldwide levels of cognitive decline.

Circulating Omega-3 and Omega-6 Fatty Acids, Cognitive Decline, and Dementia in Older Adults.

Comprising nearly 35% of brain lipids, polyunsaturated fatty acids (PUFA) are essential for optimal brain function. However, the role of PUFA on cognitive health outcomes later in life is largely unknown. We investigated prospective associations of plasma phospholipid omega-3 (ALA [18 : 3], EPA [20 : 5], DPA [22 : 5], DHA [22 : 6]) and omega-6 (LA [18 : 2], AA [20 : 4]) PUFA with cognitive decline, risk of cognitive impairment and dementia among adults aged≥65 years in the Cardiovascular Health Study. Circulating fatty acid concentrations were measured serially at baseline (1992/1993), 6 years, and 13 years later. Cognitive decline and impairment were assessed using the 100-point Modified Mini-Mental State Examination (3MSE) up to 7 times. Clinical dementia was identified using adjudicated neuropsychological tests, and ICD-9 codes. Among 3,564 older adults free of stroke and dementia at baseline, cognitive function declined annually by approximately -0.5 3MSE points; 507 participants developed cognitive impairment and 499 dementia over up to 23 years of follow-up. In multivariable models, higher circulating arachidonic acid (AA) concentrations were associated with slower cognitive decline and lower dementia risk, with associations growing stronger with greater length of follow-up (hazard ratio [HR,95% CI] of dementia per interquintile range, 0.74 [0.56-0.97] at 5 years, and 0.53 [0.37-0.77] at 15 years). Circulating docosapentaenoic (DPA) concentrations were associated with slower cognitive decline and lower risk of cognitive impairment (extreme-quintile HR, 0.72 [95% CI: 0.55, 0.95]). Findings were generally null or inconsistent for other omega-3 or omega-6 PUFA. Circulating AA and DPA, but not other PUFA, are associated with slower rate of cognitive decline and lower risk of dementia or cognitive impairment later in life.

Serum brain-derived neurotrophic factor levels as a predictor for Alzheimer disease progression.

Brain-derived neurotrophic factor (BDNF) has been implicated in the pathophysiology of Alzheimer's disease (AD), and decreased peripheral levels of this protein are associated with an increased risk of developing the disease. This study focuses on whether serum BDNF levels could be used as a predictor of AD progression. In this longitudinal observational study, we recruited cognition normal participants (N=98) and AD (N=442) from the Clinic at the Taipei Veterans General Hospital. We conducted a mini-mental status exam, a 12-item memory test, a categorical verbal fluency test, and a modified 15-item Boston naming test. A Serum BDNF level and Apolipoprotein E (APOE) allele status were measured. The AD patients were followed prospectively. Based on the difference of MMSE scores, these patients were divided into fast decliners (decline ≧ 3/year) and slow decliners (MMSE decline < 3/year). Logistic regression was conducted to examine the impact of serum BDNF levels and other factor on the likelihood of AD patients being slow decliners. Pearson's correlation was used to estimate the relationship between serum BDNF levels and the score of neuropsychological tests. In a logistic regression model containing serum BDNF levels, age, sex, APOE4 carrier status, education levels, and baseline MMSE score, higher serum BDNF levels were associated with a slower rate of cognitive decline in the AD group. Serum BDNF levels positively correlated with the results of multiple neuropsychological tests. BDNF is a protective factor against AD progression and likely plays a role in establishing a link between AD pathology and clinical manifestations.

Cardiovascular health and cognitive outcomes: Findings from a biracial population-based study in the United States.

The aim of this study was to evaluate the association of cardiovascular health (CVH) with cognitive outcomes, including incident Alzheimer's dementia, rate of cognitive decline, and measures of brain injury and structure. This study consisted of 1702 Black or African American and White participants living in the south side of Chicago, Illinois, and enrolled in the Chicago Health and Aging Project, a population-based cohort since 1993. CVH was based on seven risk factors, including diet, physical activity, body mass index, smoking, dyslipidemia, hypertension, and diabetes. In a multivariable-adjusted model, CVH was associated with a lower risk of Alzheimer's dementia. The hazard ratio per 1 additional point in CVH score was 0.84 (95% CI 0.76, 0.94). CVH was also associated with a slower rate of cognitive decline and less volume (injury) in white matter hyperintensities. Promoting CVH in communities with Black residents may lower the future risk of Alzheimer's dementia.

Life Course Socioeconomic Position and Cognitive Aging Trajectories: A Cross-National Cohort Study in China and England.

Cross-national research on cognitive aging inequality has largely concentrated on Western countries. It is unclear whether socioeconomic position (SEP) has similar effects on cognitive decline in emerging economies. We compared the association between life course SEP and cognitive function trajectories between China and England, the largest nation under state socialism and one of the oldest capitalist countries. This cross-cohort study examined participants aged 50 years and older from the China Health and Retirement Longitudinal Study (n = 12,832) and the English Longitudinal Study of aging (n = 8,875). Cognition z-scores were derived using comparable measures of memory and time orientation on 4 occasions. Life course SEP was self-reported by participants at baseline. Seven- to 8-year trajectories of cognition z-scores were estimated using latent growth curve modeling. Country- and gender-specific associations between childhood/adolescent deprivation, education, material wealth, and home ownership were evaluated in relation to model intercept (baseline level) and linear slope (annual rate of change) of cognition. After multivariable adjustment, education was positively associated with the greatest differences in baseline cognition across country and gender. Education was further linked to a slower rate of cognitive decline (z-score units per year); but compared with those with low education, Chinese men (b = 0.032) and women (b = 0.065) with high education had significantly slower declines than English men (b = -0.004) and women (b = 0.010) with high education. Despite substantial between-cohort differences in downstream and upstream determinants of dementia, education provided the greatest benefits to cognitive aging in England but particularly in China.

Relationship between social support and 7-year trajectories of cognitive decline: results from the China Health and Retirement Longitudinal Study

BackgroundSocial support is associated with cognitive function at an older age, but how distinct dimensions of social support affect trajectories of cognitive decline in older Chinese adults remains unclear.MethodsUsing longitudinal...

Association between personality traits, leisure activities, and cognitive levels and decline across 12 years in older adults.

The engagement in cognitively stimulating activities has been found to be associated with slower rates of cognitive decline in old age. In which type of activities people engage in may depend on their personality traits, which thus might have an impact on later cognitive fitness. To study these potential links, we examined the associations between Neuroticism, Extraversion, and Openness; different types of leisure activities (e.g., social, mental, physical); and cognitive ability levels and decline in older adults. Analyses were based on a sample of young-old (60-72 years old; n = 1,609) and old-old (78 years or older; n = 1,085) adults from the Swedish National Study on Aging and Care in Kungsholmen, who participated in up to five repeated measurements of cognitive abilities spanning 12 years. We used latent growth curve models to estimate cognitive levels and decline, as well as the correlations with initial personality trait levels and leisure activity engagement. In both groups, lower Neuroticism, higher Extraversion, and higher Openness levels were moderately associated with stronger engagement in all types of activities. Lower Neuroticism, higher Extraversion, and a more activity lifestyle were weakly to moderately associated with slower cognitive decline in the old-old age group. There, personality traits and activities explained 9.3% of the variance in cognitive decline after controlling for age, sex, education, and chronic diseases (which explained 9.0%). Taken together, this study provides further evidence for the connection between personality traits, activity engagement, and later cognitive decline in old age. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The National Israel Brain Repository: Characterizing those who sign and do not sign intent to autopsy

AbstractBackgroundCollection of postmortem human brain and spinal cords for research is invaluable, especially in neurodegeneration, since human clinicopathologic data may lead to better understanding their pathophysiology and to new therapeutic targets. The National Israel Brain Repository was established in 2018 and began recruiting donors from two large‐scale community‐based studies of individuals at high dementia risk: older adults with type 2 diabetes (Israel Diabetes and Cognitive Decline study‐IDCD) and middle‐aged offspring of AD patients (The Israel Registry for Alzheimer’s Prevention‐ IRAP).We compared sociodemographic, cardiovascular (CVRFs)and cognitive characteristics of individuals who agreed and did not agree to sign intent to autopsy (ITA)MethodIn the IDCD, of the 750 active participants, we approached 636. Of them, 196 (31%) agreed to sign ITA.IRAP has 480 active participants of whom 395 were approached and of them 176 (45%) agreed to sign ITA. All participants are from the Maccabi Health Services, providing CVRF data since 1998. Using t‐test we compared the groups on sociodemographic and CVRFs. For IDCD, which averages 36‐months cognitive follow ups, mixed regression models adjusting for age, sex and education tested whether signing ITA predicted cognitive trajectories. For IRAP, whose follow‐ups have only recently begun, we used linear regressions adjusting for the same covariates, compared cognitive functioning between those the two groupsResultIn the IRAP sample, participants who signed ITA did not differ from those who did not sign on any of the characteristics except for HbA1c (Table 1). In the IDCD sample, those who signed ITA had higher education, creatinine, and BMI and better motor function (hand grip and 3‐meter walk). Finally, those who signed ITA had a slower rate of decline in episodic memory (Estimate = 0.002, SE = 0.001, p = 0.05)ConclusionOur results suggest that middle‐aged adults at high AD risk willing to donate their brains to science do not differ in sociodemographic or CVRFs from those who do not wish to be organ donors. In contrast, older adults at high dementia risk due to T2D who signed ITA are more educated, have better motor function and a slower rate of cognitive decline suggesting a selection bias towards better health.Development of strategies to diminish this selection bias are warranted.

Effects of Pension Eligibility Expansion on Men’s Cognitive Function: Findings from Rural South Africa

ABSTRACT Two-thirds of people living with Alzheimer’s disease and related dementias (ADRD) live in low- and middle-income countries, and this figure is expected to rise as these populations are rapidly aging. Since evidence demonstrates links between socioeconomic status and slower rates of cognitive decline, protecting older adults’ cognitive function in resource-limited countries that lack the infrastructure to cope with ADRD is crucial to reduce the burden it places on these populations and their health systems. While cash transfers are a promising intervention to promote healthy cognitive aging, factors such as household wealth and level of education often confound the ability to make causal inferences on the impact of cash transfers and cognitive function. This study uses a quasi-experimental design, leveraging an exogenous expansion to the Old Age Pension for men in South Africa, to approximate causal associations with cognitive function. We found evidence that there is a potential benefit of cash transfers at an earlier age for older individuals. As such, transfers such as pensions or other forms of direct basic income transfers may hold promise as potential interventions to promote healthy cognitive aging.

The association of MIND diet with cognitive resilience to neuropathologies.

Cognitive resilience (CR) can be defined as the continuum of better through worse than expected cognition, given the degree of neuropathology. The relation of healthy diet patterns to CR remains to be elucidated. Using longitudinal cognitive data and post mortem neuropathology from 578 deceased older adults, we examined associations between the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet at baseline and two standardized CR measures reflecting higher cognitive levels over time (CR ), and slower decline (CRSlope ), than expected given neuropathology. Compared to individuals in the lowest tertile of MIND score, those in the top tertile had higher CR (mean difference [MD]=0.34; 95% confidence interval [CI]=0.14, 0.55) and CRSlope (MD=0.27; 95% CI=0.05, 0.48), after multivariable adjustment. Overall MIND score was more strongly related to CR than the individual food components. The MIND diet is associated with both higher cognition and slower rates of cognitive decline, after controlling for neuropathology, indicating the MIND diet may be important to cognitive resilience.

Physical Activity Is Associated with Slower Cognitive Decline in Older Adults with Type 2 Diabetes.

Physical activity is associated with slower cognitive decline in old age. Type 2 diabetes (T2d) is a risk factor for dementia and cognitive decline. Physical activity protects against several T2d complications. Yet, little is known about the contribution of physical activity to cognitive health among the elderly with T2d. To examine the association between physical activity and cognitive decline in older adults with T2d. This is a prospective longitudinal study using data from the Israel Diabetes and Cognitive Decline (IDCD) study. ICDC study (N=1,213), is a population-based cohort of adults over the age of 65, diagnosed with type 2 diabetes, who were cognitively normal at baseline and followed up every 18 months. Participants with at least one follow-up assessment who were in the same physical activity group consistently and had complete demographic data. Physical activity was measured using Minnesota Leisure Time Activity Questionnaire, cognitive functioning was measured using a broad neuropsychological assessment measuring Executive Functioning, Attention/Working Memory, Semantic Categorization and Episodic Memory. Participants were classified into physical activity groups based on self-reported physical activity at baseline and all follow ups: "active" - participation in recreational physical activity (n=286); "non-active"- the only physical activity was walking from place to place (n=93) and "sedentary" (n=19). Linear mixed effects models were applied to adjust for key demographic and cardiovascular risk factors. Participants were 72.4 (SD 4.6) years old, had 13.3 (SD 3.6) years of education, and 163 (41%) were female. In the fully adjusted model, compared to the non-active group the active group had significantly slower rate of decline in Global Cognition (p=0.005), Executive Functioning (p=.014), and Attention/Working Memory (p=.01). There were no significant group differences for Semantic Categorization (p=.17) and Episodic Memory (p=.88). Among initially cognitively normal and independent older adults with T2d, a physically active lifestyle was associated with a slower rate of cognitive decline. Future research should examine whether promoting physical activity may prevent or delay onset of dementia in this high-risk population.

NEIGHBORHOOD ADVERSITY AND COGNITIVE HEALTH: THE MODIFYING ROLE OF SELF-PERCEPTIONS OF AGING

Abstract Research has documented the increased risk of cognitive impairment among older adults living in socioeconomically disadvantaged neighborhoods. Much less is known about the factors that moderate this risk. We conceptualized self-perception of aging (SPA) as a potential moderator because it reflects core beliefs about the self at older ages but is also closely linked to late-life health. Guided by the diathesis-stress model that postulates the interactive roles of cognitive styles and stressors in shaping health outcomes, we hypothesized that more positive SPA would buffer the effects of neighborhood adversity on cognitive function. Using data from the Health and Retirement Study (2008–2016), the analytic sample consisted of adults aged 54 and older (N=5,902). Cognitive function was assessed by the Telephone Interview for Cognitive Status. The neighborhood indicators included 1) poverty rates at the census tract level, 2) perceived neighborhood social cohesion, and 3) perceived neighborhood disorder. Three-level growth curve models were separately estimated for each neighborhood indicator’s effect as well as its interaction with SPA on the 8-year cognitive function trajectories. Findings showed that higher poverty rates, more disorder, and less cohesion were associated with lower initial levels of cognitive function but slower rates of cognitive decline. SPA partially moderated the linkage between neighborhood adversity and the level of cognitive function. More positive SPA was associated with reduced negative effects of living in neighborhoods with higher poverty rates and more physical disorder. These findings highlight the intersection of an individual-level psychological factor and a contextual-level factor in shaping late-life cognition.

RELATIONSHIP QUALITY AND OLDER PARENTS' COGNITIVE TRAJECTORIES: A NATIONAL LONGITUDINAL STUDY IN THE UNITED STATES

Abstract This study aims to assess the impact of the relationship quality between parents and children on parents’ cognitive function in later life, with an additional focus on variation by parents’ gender. We analyze data from a nationally representative longitudinal panel survey of participants age 50 and older. We employ latent growth curve models (LGCM) to estimate how changes in parent-child relationship quality are related to cognitive trajectories over time. Maintaining frequent contact with children and receiving more support from children are associated with a slower rate of cognitive decline for older parents whereas experiencing relationship strain with children is associated with a faster rate of cognitive decline for older parents. These associations are stronger for mothers than fathers. This study highlights the importance of the “linked lives” of aging parents and their children. The findings have implications for the development of interventions and strategies to protect cognitive function in later life.

Cognitive Aging in Same- and Different-Sex Relationships: Comparing Age of Diagnosis and Rate of Cognitive Decline in the Health and Retirement Study

Introduction: The ongoing marginalization of lesbian, gay, and bisexual people has been hypothesized to produce poorer late-in-life cognitive outcomes, according to mechanisms posited by minority stress and allostatic load theories. Yet the existence of those outcomes remains understudied, and results of existing studies have been contradictory. Using a population-based longitudinal aging study, this paper will compare age at diagnosis of Alzheimer’s disease (AD) or a related dementia and rates of cognitive decline between participants in same-sex relationships (SSRs) and different-sex relationships (DSRs). Methods: The study used longitudinal cognitive-health data from the Health and Retirement Study (HRS; 1998–2018; N = 26,344) to analyze the onset of cognitive impairment and AD/dementia and the rates of cognitive change between participants in SSRs and those in DSRs. We hypothesized that SSR participants would have worse overall cognitive functioning in old age and would experience earlier onset of cognitive impairment. Using multiple regression, we compared the ages at which participants in SSRs and DSRs first reported AD or dementia diagnoses and the ages at which they first scored below cutoffs for cognitive impairment, not dementia (CIND) and possible dementia as determined using the cognitive assessment. The study then compared rates of cognitive decline over time across the SSR and DSR groups, including stratified analyses by education, race/ethnicity, wealth, and sex/gender. Results: Participants in SSRs reported dementia diagnoses (β = −12.346; p = 0.001), crossed the threshold into CIND (β = −8.815; p < 0.001) and possible dementia (β = −13.388; p < 0.001) at a younger age than participants in DSRs. When adjusted for covariates, participants in SSRs also had lower cognition at baseline (β = 0.745; p = 0.003), though having slower rates of cognitive decline when SSR was interacted with time (β = 0.066; p = 0.003). In separate analyses, cognitive differences for SSR participants were only found in participants without undergraduate degrees, with below-median household incomes, and women. Conclusion: Our findings support theories suggesting that marginalization and stigma cause premature cognitive impairment. Findings also suggest that higher education might mitigate the adverse effects of sexuality-minority status on cognitive aging. Results do not support these theories’ claims of more rapid cognitive decline; the lower slopes of cognitive decline with time are compatible with the possibility of slower rates of decline for aging individuals in SSRs.

Associations of Amyloid, White Matter Hyperintensities, and Hippocampal Volume with Cognitive Trajectories in the Oldest‐Old: The 90+ Study

AbstractBackgroundAmyloid pathology, vascular disease pathology, and hippocampal atrophy are associated with cognitive trajectories in older adults. However, there is almost no prior evidence on how these pathologies influence cognition in the oldest‐old.MethodWe included 216 individuals from The 90+ Study, a longitudinal study of aging and dementia in people aged 90 years and older, who had 18F‐florbetapir PET and MRI imaging. We examined the association of amyloid, white matter hyperintensities (WMH) volume, and hippocampal volume (HV) with baseline cognition and longitudinal cognitive decline. Amyloid burden was measured using the standardized uptake value ratio (SUVR) in the precuneus/posterior cingulate with white matter mask as reference. WMH volume and HV were normalized by intracranial volume (IV) and normalized WMH were log‐transformed. SUVR and HV for each individual were Z‐scored using the sample mean and standard deviation. Global cognitive performance was measured by Mental State Examination (MMSE) and modified MMSE (3MS) tests, repeated every six months. We defined baseline (time=0) as the visit closest to the PET imaging and included all visits starting from one year before baseline (time=‐1). We used linear mixed‐effects models with a random intercept to estimate the effect of pathologies on cognitive trajectories. All models included baseline age, sex, education, APOE‐ε4, time, time squared, amyloid, WMH, HV, and interactions between linear time and pathology variables.ResultAt baseline, participants were 93.2 years old on average, 65.3% were females, 10.6% were APOE‐ε4 carriers, and 66.2% had normal cognition (Table 1). Higher HV was associated with higher MMSE and 3MS scores at baseline. Both lower amyloid burden and higher HV were associated with slower rate of cognitive decline longitudinally. WMH was not associated with baseline cognition or cognitive trajectory. Parameter estimates are shown in Table 2 and illustrative cognitive trajectories predicted for a 93.2‐year‐old female with APOE‐ε4 alleles and a college degree predicted at varying degrees of amyloid, HV, and WMH are shown in Figure 1.ConclusionAmyloid burden and HV are associated with longitudinal cognitive trajectories, highlighting the utility of amyloid and HV in predicting future cognitive decline for the oldest‐old.

Leisure activity engagement across adulthood predicts cognitive change after five years: Do gender and age matter?

To examine the association between leisure activity (LA) frequency and cognitive trajectories over 5 years across adulthood, and whether gender and age moderate these associations. A total of 234 cognitively healthy adults (21-80 years) completed a LA questionnaire at baseline and neuropsychological measures at baseline and after 5 years. Latent change score analysis was applied to generate latent variables estimating changes in different cognitive domains. For a secondary analysis, LA components' scores were calculated, reflecting cognitive-intellectual, social, and physical activities. Regression analysis examined the association between baseline LA and cognitive change, and potential moderation of gender and age. In addition, we tested the influence of cortical gray matter thickness on the results. We found that higher LA engagement was associated with slower cognitive decline for reasoning, speed, and memory, as well as better vocabulary across two time points. Regarding LA components, higher Social-LA and Intellectual-LA predicted slower rates of cognitive decline across different domains, while Physical-LA was not associated with cognitive change. Gender, but not age, moderated some of the associations observed. Our results remained the same after controlling for cortical gray matter thickness. We demonstrated a protective effect of LA engagement on cognitive trajectories over 5 years, independent from demographics and a measure of brain health. The effects were in part moderated by gender, but not age. Results should be replicated in larger and more diverse samples. Our findings support cognitive reserve hypothesis and have implications for future reserve-enhancing interventions.

Intellectual enrichment and genetic modifiers of cognition and brain volume in Huntington's disease.

An important step towards the development of treatments for cognitive impairment in ageing and neurodegenerative diseases is to identify genetic and environmental modifiers of cognitive function and understand the mechanism by which they exert an effect. In Huntington's disease, the most common autosomal dominant dementia, a small number of studies have identified intellectual enrichment, i.e. a cognitively stimulating lifestyle and genetic polymorphisms as potential modifiers of cognitive function. The aim of our study was to further investigate the relationship and interaction between genetic factors and intellectual enrichment on cognitive function and brain atrophy in Huntington's disease. For this purpose, we analysed data from Track-HD, a multi-centre longitudinal study in Huntington's disease gene carriers and focused on the role of intellectual enrichment (estimated at baseline) and the genes FAN1, MSH3, BDNF, COMT and MAPT in predicting cognitive decline and brain atrophy. We found that carrying the 3a allele in the MSH3 gene had a positive effect on global cognitive function and brain atrophy in multiple cortical regions, such that 3a allele carriers had a slower rate of cognitive decline and atrophy compared with non-carriers, in agreement with its role in somatic instability. No other genetic predictor had a significant effect on cognitive function and the effect of MSH3 was independent of intellectual enrichment. Intellectual enrichment also had a positive effect on cognitive function; participants with higher intellectual enrichment, i.e. those who were better educated, had higher verbal intelligence and performed an occupation that was intellectually engaging, had better cognitive function overall, in agreement with previous studies in Huntington's disease and other dementias. We also found that intellectual enrichment interacted with the BDNF gene, such that the positive effect of intellectual enrichment was greater in Met66 allele carriers than non-carriers. A similar relationship was also identified for changes in whole brain and caudate volume; the positive effect of intellectual enrichment was greater for Met66 allele carriers, rather than for non-carriers. In summary, our study provides additional evidence for the beneficial role of intellectual enrichment and carrying the 3a allele in MSH3 in cognitive function in Huntington's disease and their effect on brain structure.

Association of Greenspace Exposure at Midlife with Cognitive Decline Later in Life in a Study of US Women

Background and aim: Greenspace may slow cognitive decline by increasing opportunities for physical activity and social connection or reducing stress or air pollution. However, studies on the association between greenspace and cognitive decline are sparse. We investigated the prospective association between greenspace at midlife and cognitive decline later in life. Methods: Using data from the US-based Nurses’ Health Study (mean age=61y), we assessed residential greenspace in a 270m buffer as the cumulative average from 1986 to 1994 using Landsat Normalized Difference Vegetation Index data. We examined 16,352 women who were enrolled in a substudy starting in 1995-2001 (74y) through 2008. Participants underwent up to four repeated measures of five cognitive tests. A global composite score was calculated as the average of all z-scores for each task to evaluate overall cognitive functioning. We evaluated the association between greenspace and subsequent cognitive decline using linear mixed models adjusted for age, education, neighborhood socioeconomic status, and depression. Results: In fully adjusted models, those living in the highest quintile of greenspace had an annual slope of decline that was slower by 0.01 units of the global composite score (95%CI 0.00001, 0.012) compared to those in the lowest quintile. To help interpret this estimate, we find that one year of age is related to a -0.01 unit mean annual difference for global cognition; thus, more greenspace appeared equivalent to slowing cognitive aging by one year. We found similar associations for the Telephone Interview for Cognitive Status (TICS); participants living in the highest greenspace quintile had an annual rate of decline that was slower by 0.04 units in the TICS score (95%CI 0.01, 0.07) compared to those in the lowest quintile. Conclusions: Higher greenspace exposure in early adulthood is associated with a slower rate of cognitive decline later in life in this cohort of US women.