The role of cognitive and social leisure activities in dementia risk: assessing longitudinal associations of modifiable and non-modifiable risk factors

Genomic Insights into Dementia: Precision Medicine and the Impact of Gene-Environment Interaction

The diagnosis, treatment, and management of dementia provide significant challenges due to its chronic cognitive impairment. The complexity of this condition is further highlighted by the impact of gene-environment interactions. A recent strategy combines advanced genomics and precision medicine methods to explore the complex genetic foundations of dementia. Utilizing the most recent research in the field of neurogenetics, the importance of precise genetic data in explaining the variation seen in dementia patients can be investigated. Gene-environment interactions are important because they influence genetic susceptibilities and aid in the development and progression of dementia. Modified to each patient's genetic profile, precision medicine has the potential to detect groups at risk and make previously unheard-of predictions about the course of diseases. Precision medicine techniques have the potential to completely transform treatment and diagnosis methods. Targeted medications that target genetic abnormalities will probably appear, providing the possibility for more efficient and customized medical interventions. Investigating the relationship between genes and the environment may lead to preventive measures that would enable people to change their surroundings and minimize the risk of dementia, leading to the improved lifestyle of affected people. This paper provides a comprehensive overview of the genomic insights into dementia, emphasizing the pivotal role of precision medicine, and gene-environment interactions.

The Mediating Role of Lifestyle Activities in the Association Between Social Deprivation and Cognition in Older Adulthood: Results From the Health and Retirement (HRS) Study

Objectives: We aimed to investigate the mediating role of lifestyle activities in the association between social deprivation and cognition. Methods: To investigate, we analysed data of 3867 respondents (Mean Age: 73.37, SD: 5.57) in the U.S. Health and Retirement Study (HRS) using growth curve and path analysis, adjusted for demographic and health covariates. Results: Being in the high (vs. moderate) Social Deprivation Index group was associated with lower cognition scores (β = -2.63, [95 % CI: -2.90, -2.36]). Conversely, higher (vs. lower) Lifestyle Index scores were associated with higher cognition scores (β = 1.17, [95 % CI: 0.72, 1.63]). In mediation analysis, the Lifestyle Index score explained 27 % of the association of So Dep Index group on cognition at the final follow-up. Discussion: While lifestyle activities did mediate the association between social deprivation and cognition, factors not investigated accounted for the majority of the variation. These may include systemic disadvantages.

Association between adult education, brain volume and dementia risk: longitudinal cohort study of UK Biobank participants

Less childhood education is a potentially modifiable risk factor for developing incident dementia but it is not known if education in later life is protective. We sought to add to previous work by testing the association between adult education and brain volume as well as exploring the impact of continuing adult education versus intermittent participation. We used data from participants of the UK Biobank cohort, with no prevalent dementia who were asked about adult education participation at baseline and at follow-up. Dementia status was ascertained from self-report or electronic health records. Cox proportional hazards models were built to estimate hazard ratios (HRs) between participation in adult education and dementia risk. In 499,337 participants aged between 40 and 69 at baseline with 13.2 years mean follow-up, in analyses adjusted for age, sex, education, deprivation, ethnicity, hypertension, diabetes, ethnicity, obesity, smoking, alcohol use, physical inactivity and social isolation, we replicated previous findings of a protective effect of adult education on dementia risk (HR 0.82, 95% CI 0.74-0.90, P < 0.001), and showed a trend towards protection against dementia if adult education was continued rather than intermittent. Additionally, adult education did not impact on total brain volume (coefficient - 657.4, 95% CI - 2795.1 to 1480.3, P = 0.547) but it was associated with increased hippocampal volume (coefficient 33.9, 95% CI 8.9 to 59.0, P = 0.008) indicating a potential mechanism for protection against dementia. We have added evidence indicating that continuing adult education participation may be beneficial, although numbers for this analysis were very small. Analysis of brain volume indicated that adult education may have a protective effect by preserving hippocampal size or slowing volume loss, in line with the cognitive reserve hypothesis.

Prospective Impacts of Social Participation Activities on Cognitive and Psychopathological Statuses in Community-Dwelling Older Adults

OBJECTIVES

This study investigated the impact of social activities on cognitive functioning and psychopathological symptoms.

METHODS

Participants aged 55 or older were enrolled through communities. Initial measures assessed demographic data, neuropsychological functioning, psychopathological state, and happiness. Social activities were evaluated using a modified 12-item tool, with 3-4 activities as the cutoff. Follow-up after 6-9 months included Mini-Mental State Examination (MMSE), Beck Depression Inventory - II (BDI-II), Beck Anxiety Inventory (BAI), Health Assessment Questionnaire (HAQ), and Patient Health Questionnaire-15 (PHQ-15) measurements. Predictive models for psychiatric and cognitive statuses were built using multiple linear regression, adjusting for baseline conditions.

RESULTS

Initially, 516 older individuals enrolled, with 403 undergoing follow-up. During follow-up, the low participation group reported lower MMSE scores, higher BAI scores, and increased PHQ-15 risk. Negative correlations between social activity numbers and PHQ-15 results were found. Engagement in social clubs correlated positively with higher MMSE scores, while regular interactions with one's adult child(ren) were linked to decreased BAI scores.

CONCLUSIONS

The quantity of social activities was associated with lower somatic distress. Social club engagement positively influenced cognition, and regular interactions with one's adult child(ren) mitigated anxiety among older individuals.

CLINICAL IMPLICATIONS

Enough types of social activities, participating in social clubs, and adequate interactions with children protected against psychopathologies.

Gender-specific analysis of social connection patterns and risk of dementia in community-dwelling older people

INTRODUCTION

Poor social connection is considered a risk factor for dementia. Since socializing behaviors may cluster together or act compensatorily, we aimed to investigate social connection patterns and their association with dementia, for men and women separately.

METHODS

A total of 12,896 community-dwelling older adults (mean ± SD age: 75.2 ± 4.3 years, 54% women) without major cognitive impairment were included. Latent class analysis was conducted using 24 baseline social connection indicators. Cox proportional hazards regression was used to estimate the association between latent classes and incident dementia over 12 (median: 8.4) years follow-up.

RESULTS

Three distinct classes were identified in both genders: strong social connections with an intermediate friend-relative network (Class 1: men, 43.8%; women, 37.9%), weak social connections (Class 2: men, 29.6%; women, 27.4%), and strong social connections with a larger friend-relative network (Class 3: men, 26.6%; women, 34.7%). Compared to Class 1, men in Class 2 (HR: 1.38, 95% CI: 1.08-1.77) and women in Class 3 (HR: 1.27, 95% CI: 1.01-1.60) had an increased risk of dementia.

DISCUSSION

Dementia risk varies with different social connection patterns among older men and women.

HIGHLIGHTS

Three distinct social connection patterns were identified based on 24 indicators. These patterns were related to dementia risk differently in men and women. In men, a weak social connection pattern was associated with a higher dementia risk. In women, a strong social connection with a relatively larger friend-relative network was associated with a greater dementia risk.

Associations of an individual's need for cognition with structural brain damage and cognitive functioning/impairment: cross-sectional population-based study

BACKGROUND

High cognitive activity possibly reduces the risk of cognitive decline and dementia.

AIMS

To investigate associations between an individual's need to engage in cognitively stimulating activities (need for cognition, NFC) and structural brain damage and cognitive functioning in the Dutch general population with and without existing cognitive impairment.

METHOD

Cross-sectional data were used from the population-based cohort of the Maastricht Study. NFC was measured using the Need For Cognition Scale. Cognitive functioning was tested in three domains: verbal memory, information processing speed, and executive functioning and attention. Values 1.5 s.d. below the mean were defined as cognitive impairment. Standardised volumes of white matter hyperintensities (WMH), cerebrospinal fluid (CSF) and presence of cerebral small vessel disease (CSVD) were derived from 3T magnetic resonance imaging. Multiple linear and binary logistic regression analyses were used adjusted for demographic, somatic and lifestyle factors.

RESULTS

Participants (n = 4209; mean age 59.06 years, s.d. = 8.58; 50.1% women) with higher NFC scores had higher overall cognition scores (B = 0.21, 95% CI 0.17-0.26, P < 0.001) and lower odds for CSVD (OR = 0.74, 95% CI 0.60-0.91, P = 0.005) and cognitive impairment (OR = 0.60, 95% CI 0.48-0.76, P < 0.001) after adjustment for demographic, somatic and lifestyle factors. The association between NFC score and cognitive functioning was similar for individuals with and without prevalent cognitive impairment. We found no significant association between NFC and WMH or CSF volumes.

CONCLUSIONS

A high need to engage in cognitively stimulating activities is associated with better cognitive functioning and less presence of CSVD and cognitive impairment. This suggests that, in middle-aged individuals, motivation to engage in cognitively stimulating activities may be an opportunity to improve brain health.

Cognitive reserve over the life course and risk of dementia: a systematic review and meta-analysis

Background

The number of people with dementia is soaring. Cognitive reserve has been thought to be associated with dementia risk. It is not clear at which period in the life course and which cognitive reserve proxies contribute to the reduced risk of dementia.

Methods

By scanning four databases (PubMed, Embase, Web of Science, and MEDLINE) up to Jun 3, 2023, longitudinal studies of life-course cognitive reserve and risk of dementia were found. The HRs and 95% CIs for each study were summarized using random effects models. Subgroup analyses and sensitivity analyses were conducted. Utilizing funnel plots, Begg and Egger tests, publication bias was investigated.

Results

A total of 27 studies were included, containing 10 in early-life, 10 in middle-life, and 13 in late-life. All studies used validated questionnaires to measure cognitive reserve, and dementia diagnosis followed recognized worldwide guidelines. All included studies were of medium or low risk. Cognitive reserve in early-life (Hazard ratio (HR): 0.82; 95% confidence interval (CI): 0.79-0.86), middle-life (HR: 0.91; 95% CI: 0.84-0.98) and late-life (HR: 0.81; 95% CI: 0.75-0.88) all have protective effects on dementia risk. Multiple sensitivity analyses showed consistent results.

Conclusion

Dementia risk is reduced by the buildup of cognitive reserves during life-course. Accumulation of proxies for cognitive reserve in early and late life had the greatest effect on dementia risk reduction. Social connection may be an effective approach to lower dementia risk.

Handicraft art leisure activities and cognitive reserve

ObjectiveOlder individuals face a higher likelihood of developing dementia. The rate of cognitive decline resulting from dementia is not equivalent for all, as some patients with dementia are able to function independently longer than others, despite having similar disease burden. The cognitive reserve (CR) theory provides one explanation for the differing rate of decline. CR suggests that there are factors-most notably, educational attainment and occupational attainment-that can protect against the cognitive decline. Although the beneficial effects of these notable CR factors are clear, not all are easily modifiable. Participation in leisure activities may represent a more easily modifiable factor. Some research hints at beneficial effects of leisure activities, although specific leisure activities have not been well examined. The present study examined the relations between handicraft art leisure activities (HALAs) and multiple cognitive domains. MethodArchival WAIS-IV and demographic data for 50 California retirement community residents were examined. ResultsHALA participation accounted for statistically significant variance in working memory performance (R2 = .40, β = .24%) over and above the established CR factors of age, depression, educational attainment, and occupational attainment. In addition, HALA participation was related to a better ability to perform abstract visual information tasks (Block Design subtest, r = .28, p = .05) and non-verbal reasoning tasks (Visual Puzzles subtest, r = .38, p = .008). ConclusionsHALA participation among older adults could contribute to the retention of cognitive function, supporting the role of HALA participation as a CR factor.

Lifetime occupational skill and later-life cognitive function among older adults in the United States, Mexico, India, and South Africa

INTRODUCTION

We conducted a cross-national comparison of the association between main lifetime occupational skills and later-life cognitive function across four economically and socially distinct countries.

METHODS

Data were from population-based studies of aging and their Harmonized Cognitive Assessment Protocols (HCAPs) in the US, South Africa, India, and Mexico (N = 10,037; Age range: 50 to 105 years; 2016 to 2020). Main lifetime occupational skill was classified according to the International Standard Classification of Occupations. Weighted, adjusted regression models estimated pooled and country-specific associations between main lifetime occupational skill and later-life general cognitive function in men and women.

RESULTS

We observed positive gradients between occupational skill and later-life cognitive function for men and women in the US and Mexico, a positive gradient for women but not men in India, and no association for men or women in South Africa.

DISCUSSION

Main lifetime occupations may be a source of later-life cognitive reserve, with cross-national heterogeneity in this association.

HIGHLIGHTS

No studies have examined cross-national differences in the association of occupational skill with cognition. We used data from Harmonized Cognitive Assessment Protocols in the US, Mexico, India, and South Africa. The association of occupational skill with cognitive function varies by country and gender.

Umbrella review and Delphi study on modifiable factors for dementia risk reduction

A 2013 systematic review and Delphi consensus study identified 12 modifiable risk and protective factors for dementia, which were subsequently merged into the "LIfestyle for BRAin health" (LIBRA) score. We systematically evaluated whether LIBRA requires revision based on new evidence. To identify modifiable risk and protective factors suitable for dementia risk reduction, we combined an umbrella review of systematic reviews and meta-analyses with a two-round Delphi consensus study. The review of 608 unique primary studies and opinions of 18 experts prioritized six modifiable factors: hearing impairment, social contact, sleep, life course inequalities, atrial fibrillation, and psychological stress. Based on expert ranking, hearing impairment, social contact, and sleep were considered the most suitable candidates for inclusion in updated dementia risk scores. As such, the current study shows that dementia risk scores need systematic updates based on emerging evidence. Future studies will validate the updated LIBRA score in different cohorts. HIGHLIGHTS: An umbrella review was combined with opinions of 18 dementia experts. Various candidate targets for dementia risk reduction were identified. Experts prioritized hearing impairment, social contact, and sleep. Re-assessment of dementia risk scores is encouraged. Future work should evaluate the predictive validity of updated risk scores.

Long-term environmental enrichment is associated with better fornix microstructure in older adults

Background

Sustained environmental enrichment (EE) through a variety of leisure activities may decrease the risk of developing Alzheimer's disease. This cross-sectional cohort study investigated the association between long-term EE in young adulthood through middle life and microstructure of fiber tracts associated with the memory system in older adults.

Methods

N = 201 cognitively unimpaired participants (≥ 60 years of age) from the DZNE-Longitudinal Cognitive Impairment and Dementia Study (DELCODE) baseline cohort were included. Two groups of participants with higher (n = 104) or lower (n = 97) long-term EE were identified, using the self-reported frequency of diverse physical, intellectual, and social leisure activities between the ages 13 to 65. White matter (WM) microstructure was measured by fractional anisotropy (FA) and mean diffusivity (MD) in the fornix, uncinate fasciculus, and parahippocampal cingulum using diffusion tensor imaging. Long-term EE groups (lower/higher) were compared with adjustment for potential confounders, such as education, crystallized intelligence, and socio-economic status.

Results

Reported participation in higher long-term EE was associated with greater fornix microstructure, as indicated by higher FA (standardized β = 0.117, p = 0.033) and lower MD (β = -0.147, p = 0.015). Greater fornix microstructure was indirectly associated (FA: unstandardized B = 0.619, p = 0.038; MD: B = -0.035, p = 0.026) with better memory function through higher long-term EE. No significant effects were found for the other WM tracts.

Conclusion

Our findings suggest that sustained participation in a greater variety of leisure activities relates to preserved WM microstructure in the memory system in older adults. This could be facilitated by the multimodal stimulation associated with the engagement in a physically, intellectually, and socially enriched lifestyle. Longitudinal studies will be needed to support this assumption.

Knowledge and motivation to adopt recommended health behaviours to reduce dementia risk among the elderly in Norway: a qualitative study

OBJECTIVES

Dementia is a major healthcare challenge; however, there is evidence that modifiable risk factors may contribute to reduce dementia risk. The aim of the study was to explore the knowledge and motivation for adopting recommended health behaviours among older adults in Norway.

STUDY DESIGN

The study has a qualitative, descriptive design.

METHODS

Individual interviews were used for data collection. The study population comprised 15 participants, five men and 10 women, aged ≥73 years, recruited from a region in the centre of Norway. Interviews were analysed according to qualitative content analysis.

RESULTS

Three categories were identified and presented as the main findings, as follows: (1) sufficient knowledge about risk reduction for dementia, including the media as the main source of information; (2) current prevention activities and motivation for risk reduction, including physical, social and cognitive activities and a healthy diet; and (3) motivation for prevention of dementia from a life-course perspective, including experience of health problems, desire to live independently and limited awareness of dementia risk factors in midlife.

CONCLUSIONS

To tailor information about the modifiable risk factors of dementia and develop preventive interventions, knowledge about motivating factors is essential. Promotion of healthy ageing is required in addition to addressing the fear of future illness and dependency.

Incorporation of concussion history as part of the LIfestyle for BRAin Health (LIBRA) modifiable factors risk score and associations with cognition in older former National Football League players

OBJECTIVE

Investigate associations between the LIfestyle for BRAin Health (LIBRA) risk score with odds of mild cognitive impairment (MCI) diagnosis and cognitive function, incorporating concussion history.

METHODS

Former National Football League (NFL) players (N = 1050; mean age = 64.8 ± 9.0-years) completed initial testing for integration of concussion history into LIBRA scores (i.e., modified-LIBRA) and completed the Brief Test of Adult Cognition by Telephone (BTACT). Modified-LIBRA score (including concussion history) associations with odds of MCI and cognitive dysfunction were assessed via logistic and linear regression.

RESULTS

The highest quartile LIBRA scores were six times more likely to have a diagnosis of MCI compared to the lowest quartile (OR = 6.27[3.61, 10.91], p < 0.001). Modified-LIBRA scores significantly improved model fit for odds of MCI above original LIBRA scores (χ2 (1) = 7.76, p = 0.005) and accounted for a greater fraction of variance in executive function (ΔR2  = 0.02, p = 0.003) and episodic memory (ΔR2  = 0.02, p = 0.002).

CONCLUSIONS

Modified-LIBRA score, incorporating concussion history, may help monitoring risk status in former contact sport athletes, by targeting modifiable, lifestyle-related risk factors.

The Impact of Dance Movement Interventions on Psychological Health in Older Adults without Dementia: A Systematic Review and Meta-Analysis

BACKGROUND

Lifestyle-based multimodal interventions that integrate physical, sensory, cognitive and social enrichment are suggested to promote healthy mental aging and resilience against aging and Alzheimer's disease (AD).

OBJECTIVES

This meta-analysis examined the efficacy of dance movement interventions (DMI) as an integrated mind-body activity on outcomes of psychological health in older adults.

METHODS

Pre-registration was carried out with PROSPERO (CRD42021265112). PubMed, Web of Science and PsycINFO were searched for randomized controlled trials (RCT) evaluating the effects of DMI (>4 weeks' duration) compared to comparators on measures of psychological health (primary outcome) and cognitive function (additional outcome) among older adults without dementia (aged ≥55). Data of 14 primary RCT (n = 983, n-DMI = 494, n-control = 489) were synthesized using a random effects meta-analysis with robust variance estimation.

RESULTS

DMI had a small positive effect on overall psychological health (g = 0.30; 95% confidence interval [CI]: 0.06, 0.53; p = 0.02, I²= 65.04) compared to control conditions. Small effects of DMI on positive and negative psychological domains as well as quality of life were not statistically significant. DMI had a medium positive effect on general cognitive function (g = 0.50; 95% CI: 0.12, 0.89, p = 0.02, I²= 79.61) over comparators. None of the primary intervention studies evaluated measures of neuroplasticity.

CONCLUSIONS

We found that DMI was effective in promoting mental health amongst older adults without dementia, suggesting that the multimodal enrichment tool is a potential strategy for health promotion and prevention of AD. High-quality intervention studies are needed to expand evidence on DMI-induced changes in specific psychological domains and identify underlying neurophysiological correlates.

Social participation and risk of developing dementia

The increasing number of people with dementia globally illustrates the urgent need to reduce dementia's scale and impact. Lifetime social participation may affect dementia risk by increasing cognitive reserve, and through brain maintenance by reducing stress and improving cerebrovascular health. It may therefore have important implications for individual behavior and public health policy aimed at reducing dementia burden. Observational study evidence indicates that greater social participation in midlife and late life is associated with 30-50% lower subsequent dementia risk, although some of this may not be causal. Social participation interventions have led to improved cognition but, partly due to short follow-up and small numbers of participants, no reduction in risk of dementia. We summarize the evidence linking social participation with dementia, discuss potential mechanisms by which social participation is likely to reduce and mitigate the impact of neuropathology in the brain, and consider the implications for future clinical and policy dementia prevention interventions.

Eight-Year Trajectories of Late-Life Loneliness and Incident Dementia: A Nationally Representative Cohort Study

OBJECTIVE

Some older adults with loneliness might have transient loneliness, followed by full remission, while others might have persistent loneliness. Such different courses might differ in predicting the risk of dementia, but most previous studies assessed short-term loneliness at a single time point, ignoring the long-term changes of loneliness. This study aimed to explore the association between 8-year trajectories of late-life loneliness and incident dementia.

METHODS

Data were from the English Longitudinal Study of Ageing (waves 2-9). This study included 6,722 older adults measured for loneliness greater than or equal to three times from wave 2 (2004-2005) to wave 6 (2012-2013) and free from dementia in wave 6. Loneliness was assessed using the short 1980 version of the University of California, Los Angeles Loneliness Scale. Group-based trajectory modeling was used to explore loneliness trajectories during waves 2-6. Cox proportional hazard models were used to investigate the association of loneliness trajectories with incident dementia during waves 6-9.

RESULTS

Five distinct loneliness trajectories were identified: long-term low, persistently decreasing, persistently increasing, long-term moderate, and long-term high. Compared with long-term low loneliness, the HRs (95% confidence intervals) for persistently decreasing, persistently increasing, long-term moderate, and long-term high loneliness were 1.29 (0.83-2.00), 1.55 (1.04-2.31), 1.56 (1.03-2.38), and 3.35 (1.89-5.91), respectively.

CONCLUSION

The elderly show distinct patterns of loneliness over time, which cannot be captured by a single assessment of loneliness. The elderly with long-term loneliness and persistently increasing loneliness might be the high-risk group for dementia. Further studies are needed to determine whether reducing loneliness can prevent dementia.