Pathways From Social Activities to Cognitive Functioning: The Role of Physical Activity and Mental Health

10-Year Cognitive Change in the Faroese Septuagenarian Cohort and Impact of Sociodemographic, Lifestyle, and Health Factors

OBJECTIVES

To investigate cognitive change in multiple cognitive domains in a population-based cohort of 713 Faroese older adults.

METHODS

Participants were cognitively tested at baseline (70-74 years) and re-evaluated after 10 years. Changes in cognitive performance and the impact of sociodemographic factors, lifestyle, and health conditions were analysed using mixed-effect models. Participants free from dementia were studied in separate analyses.

RESULTS

A significant decline over 10 years was observed in most of the neuropsychological tests. People living in rural areas, married or cohabiting people, people without professional education, slightly older persons, smokers, teetotalers, and people with heart disease and abnormal electrocardiogram (ECG) had a steeper decline in cognitive ability. Conflicting results were found for sex and people with myocardial infarction (MI).

DISCUSSION

There are modifiable factors that contribute to cognitive decline which should be addressed in future public health efforts.

Mid-life social participation in people with intellectual disability: The 1958 British birth cohort study

BACKGROUND

Low social participation is a potentially modifiable risk factor for cognitive deterioration in the general population and related to lower quality of life (QoL). We aimed to find out whether social participation is linked to cognitive deterioration and QoL for people with borderline intellectual functioning and mild intellectual disability.

METHOD

We used data from the National Child Development Study, consisting of people born during one week in 1958, to compare midlife social participation in people with mild intellectual disability, borderline intellectual functioning, and without intellectual impairment. We defined social participation as 1. confiding/emotional support from the closest person and social network contact frequency at age 44, and 2. confiding relationships with anyone at age 50. We then assessed the extent to which social participation mediated the association between childhood intellectual functioning and cognition and QoL at age 50.

RESULTS

14,094 participants completed cognitive tests at age 11. People with borderline intellectual functioning and mild intellectual disability had more social contact with relatives and confiding/emotional support from their closest person, but fewer social contacts with friends and confiding relationships with anyone than those without intellectual disability. Having a confiding relationship partially mediated the association at age 50 between IQ and cognition (6.4%) and QoL (27.4%) for people with borderline intellectual functioning.

CONCLUSION

We found adults with intellectual disability have positive family relationships but fewer other relationships. Even at the age of 50, confiding relationships may protect cognition for people with borderline intellectual functioning and are important for QoL.

Well-designed manufacturing work improves some cognitive abilities in individuals with cognitive impairments

Introduction

Employment is recognized as a fundamental human right, which correlates with better physical and mental health. Importantly, well-designed work, which considers the physical, social, and psychological impacts of work, can serve to enhance the cognitive abilities of workers. Although often overlooked, work for individuals with disabilities, including cognitive impairments, is equally important for their physical and mental well-being. What has not been established, however, is whether well-designed work can also enhance the cognitive abilities of individuals with cognitive impairments.

Methods

Using a longitudinal study design, we investigated the impact of well-designed work on the cognitive abilities of 60 participants (operators) at the AMIPI Foundation factories, which employ individuals with cognitive impairments to produce electrical cables and harnesses for the automobile industry. The same operators were assessed at three different time points: upon hiring (n = 60), and after working in the factory for 1 year (n = 41, since 19 left the factory) and 2 years (n = 28, since 13 more left the factory). We used five cognitive tests evaluating: (1) finger and manual dexterity, bimanual dexterity, and procedural memory using the Purdue Pegboard; (2) sustained and selective attention using the Symbol Cancellation Task; (3) short- and long-term declarative verbal memory and long-term verbal recognition memory using Rey's Audio-Verbal Learning Test; (4) short- and long-term visual recognition memory using the Continuous Visual Memory Test; and (5) abstract reasoning using Raven's Standard Progressive Matrices.

Results

We observed improvements in procedural memory, sustained and selective attention, and short- and long-term visual recognition memory after working in the factory for 1 or 2 years. We did not observe improvements in finger or manual dexterity or bimanual dexterity, nor short- or long-term declarative verbal memory or verbal recognition memory, nor abstract reasoning.

Discussion

We conclude that, in addition to improving physical and mental well-being, well-designed manufacturing work can serve as a training intervention improving some types of cognitive functioning in individuals with cognitive impairments.

Resistance training's impact on blood biomarkers and cognitive function in older adults with low and high risk of mild cognitive impairment: a randomized controlled trial

BACKGROUND

The aging brain exhibits a neuroinflammatory state, driven partly by peripheral pro-inflammatory stimuli, that accelerates cognitive deterioration. A growing body of evidence clearly indicates that physical exercise partly alleviates neuroinflammation and positively affects the aging process and cognition. In this randomized controlled trial, we aimed to observe the effect of 12 weeks of resistance training (RT) on peripheral biomarker levels, cognitive function changes and their interrelationship, and explore differences in those exercise-induced changes in older adults with high risk of mild cognitive impairment (MCI) compared to older adults with low risk of MCI.

METHODS

Fifty-two participants (aged 60-85 years old, 28 female) were randomly allocated to a 12 week lower limb RT program consisting of two training sessions per week or waiting list control group. The Montreal Cognitive Assessment (MoCA) was used to stratify participants screened as high (< 26/30) or low risk (≥ 26/30) of MCI. We assessed serum Interleukin 6 (IL-6), Insulin-like Growth Factor-1 (IGF-1), and Kynurenine (KYN) levels. Cognitive measurement consisted of and four subtests of Automated Neuropsychological Assessment Metrics (ANAM), the two-choice reaction time, go/no-go, mathematical processing, and memory search test.

RESULTS

Twelve weeks of RT improved Go/No-go test results in older adults with high MCI risk. RT did not significantly affect blood biomarkers. However, IGF-1 level increases were associated with improvements in response time on the mathematical processing test in the exercise group, and IL-6 level increases were associated with improvements in response time on the memory search test in the total group of participants. Finally, KYN levels significantly differed between older adults with low and high MCI risk but no significant associations with performance were found.

CONCLUSION

Our study results suggest a different effect of RT on inhibitory control between older adults with low compared to high MCI risk. IGF-1 may play a role in the mechanism behind the cognitive benefit of RT and KYN may be a surrogate biomarker for neurodegeneration and cognitive decline.

Is Formal Social Participation Associated with Cognitive Function in Middle-Aged and Older Adults? A Systematic Review with Meta-Analysis of Longitudinal Studies

This systematic review with meta-analysis aimed to explore the association between formal social participation and cognitive function in middle-aged and older adults using data from longitudinal studies. A comprehensive search was conducted in Scopus, PubMed, and Web of Science for longitudinal studies that assessed the association between formal social participation and cognitive function in middle-aged and older adults published between January 2010 to 19 August 2022. Risk of bias was judged using the RoBANS tool. Meta-analysis using a random-effects model was computed with odds ratio (OR) and 95% confidence interval (CI) for cognitive decline probability. Sensitivity analyses were made to explore any changes to the pooled statistical heterogeneity and pooled effect size. Certainty of evidence was judged using the GRADE framework. We included 15 studies comprising 136,397 participants from 5 countries. Meta-analyses showed that formal social participation was associated with reduced cognitive decline (OR = 0.78, 95% CI 0.75-0.82, p < 0.001), with very low certainty of evidence. Formal social participation appears to enhance cognition in middle-aged and older adults, but further high-quality research is needed given the very low certainty of evidence.

Effects of neighborhood built environment on cognitive function in older adults: a systematic review

BACKGROUND

In the background of an aging population, the risk of cognitive impairment in the older population is prominent. Exposure to complex neighborhood built environments may be beneficial to the cognitive health of older adults, and the purpose of this study was to systematically review the scientific evidence on the effects of neighborhood built environments on cognitive function in older adults.

METHODS

Keywords and references were searched in Web of Science, Pubmed, PsycINFO, and MEDLINE. Studies examining the relationship between the built environment and cognitive function in older adults were included. The neighborhood built environment as an independent variable was classified according to seven aspects: density, design, diversity, destination accessibility, public transportation distance, blue/green space, and built environment quality. The cognitive function as the dependent variable was classified according to overall cognitive function, domain-specific cognitive function, and incidence of dementia. The quality of the included literature was assessed using the National Institutes of Health's Observational Cohort and Cross-Sectional Study Quality Assessment Tool.

RESULTS

A total of 56 studies were included that met the inclusion criteria, including 31 cross-sectional studies, 23 longitudinal studies, 1 cross-sectional study design combined with a case-control design, and 1 longitudinal study design combined with a case-control design. Most of the studies reviewed indicate that the built environment factors that were positively associated with cognitive function in older adults were population density, street connectivity, walkability, number of public transportation stops around the residence, land use mix, neighborhood resources, green space, and quality of the neighborhood built environment. Built environment factors that were negatively associated with cognitive function in older adults were street integration, distance from residence to main road. The relationship between residential density, destination accessibility, and blue space with cognitive function in older adults needs to be further explored.

CONCLUSION

Preliminary evidence suggests an association between the neighborhood built environment and cognitive function in older adults. The causal relationship between the built environment and cognitive function can be further explored in the future using standardized and combined subjective and objective assessment methods, and longitudinal or quasi-experimental study designs. For public health interventions on the cognitive health of older adults, it is recommended that relevant authorities include the neighborhood built environment in their intervention programs.

Association between formal social participation and cognitive function in middle-aged and older adults: a longitudinal study using SHARE data

Formal social participation significantly impacts health and well-being, potentially mitigating cognitive decline, although not consistently across all studies. Existing research often focuses solely on baseline participation levels, and age-related differences have primarily been explored among the Asian population. Therefore, this longitudinal study aims to assess the association between formal social participation and cognition across different age groups in individuals aged 50+ living in Europe and Israel, while capturing the dynamic nature of formal social participation. We use data from three waves (four, six, and eight) of the Survey of Health, Ageing, and Retirement in Europe (SHARE), comprising 85,601 respondents. Linear mixed-effects models were applied. The results show that participation in formal social activities mitigates cognitive decline in middle-aged and older adults, especially among those aged 70 to 79 and 80+. These findings support the need for social policies promoting formal social activities, for lasting cognitive health benefits.

Reciprocal associations of posttraumatic stress symptoms and cognitive decline in community-dwelling older adults: The mediating role of depression

BACKGROUND

People with posttraumatic stress disorder (PTSD) may have cognitive decline, a risk which can be particularly threatening at old age. However, it is yet unclear whether initial cognitive decline renders one more susceptible to subsequent PTSD following exposure to traumatic events, whether initial PTSD precedes cognitive decline or whether the effects are reciprocal.

OBJECTIVE

This study examined the bidirectional longitudinal associations between cognitive function and PTSD symptoms and whether this association is mediated by depressive symptoms.

METHOD

The study used data from two waves of the Israeli component of the Survey of Health, Ageing, and Retirement in Europe (SHARE), collected in 2013 and 2015. This study focused on adults aged 50 years and above (N = 567, mean age = 65.9 years). Each wave used three measures of cognition (recall, fluency, and numeracy) and PTSD symptoms following exposure to war-related events. Data were analyzed using mediation analysis with path analysis.

RESULTS

Initial PTSD symptoms predicted cognitive decline in recall and fluency two years later, while baseline cognitive function did not impact subsequent PTSD symptoms. Partial mediation showed that older adults with more PTSD symptoms had higher depressive symptoms, which in turn were linked to subsequent cognitive decline across all three measures.

CONCLUSIONS

This study reveals that PTSD symptoms are linked with subsequent cognitive decline, supporting approaches addressing this direction. It further indicates that part of this effect can be explained by increased depressive symptoms. Thus, treatment for depressive symptoms may help reduce cognitive decline due to PTSD.

Decomposing the change in the cognitive function gap between older men and women over time in China: The Chinese Longitudinal Healthy Longevity Survey

Background

This study explored how modifiable social determinants of cognitive function can influence these gender gaps.

Methods

We utilized six waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), including 56,127 individuals aged 65+. The Kitagawa-Oaxaca-Blinder decomposition approach was used for the analysis.

Results

Older women consistently had lower average levels of cognitive function than men in each period, but the gap is narrowing. From 2002 to 2018, the gender gap in cognitive function decreased by 1.45 (95% confidence interval (CI) = -1.843, -1.097) points. The coefficients for the endowment effects decreased from 0.387 (95% CI = -0.563, -0.211) to 1.789 (95% CI = -2.471, -1.107) from 2005 to 2018. Lifestyle changes, social participation, and physical health factors significantly contributed to explaining the changes in gender gaps in cognitive function.

Conclusions

Among these contributing factors, lifestyle, social participation, and physical health have emerged as pivotal elements in reducing the gender gap in cognitive function. Targeted interventions for these variables are essential among older women to narrow the cognitive gender gaps effectively.

Meta-analysis of age-related cognitive decline reveals a novel locus for the attention domain and implicates a COVID-19-related gene for global cognitive function

INTRODUCTION

Cognitive abilities have substantial heritability throughout life, as shown by twin- and population-based studies. However, there is limited understanding of the genetic factors related to cognitive decline in aging across neurocognitive domains.

METHODS

We conducted a meta-analysis on 3045 individuals aged ≥65, derived from three population-based cohorts, to identify genetic variants associated with the decline of five neurocognitive domains (attention, memory, executive function, language, visuospatial function) and global cognitive decline. We also conducted gene-based and functional bioinformatics analyses.

RESULTS

Apolipoprotein E (APOE)4 was significantly associated with decline of memory (p = 5.58E-09) and global cognitive function (p = 1.84E-08). We identified a novel association with attention decline on chromosome 9, rs6559700 (p = 2.69E-08), near RASEF. Gene-based analysis also identified a novel gene, TMPRSS11D, involved in the activation of SARS-CoV-2, to be associated with the decline in global cognitive function (p = 4.28E-07).

DISCUSSION

Domain-specific genetic studies can aid in the identification of novel genes and pathways associated with decline across neurocognitive domains.

HIGHLIGHTS

rs6559700 was associated with decline of attention. APOE4 was associated with decline of memory and global cognitive decline. TMPRSS11D, a gene involved in the activation of SARS-CoV-2, was implicated in global cognitive decline. Cognitive domain abilities had both unique and shared molecular pathways across the domains.

Differences in the influence of daily behavior on health among older adults in urban and rural areas: evidence from China

Background

As the population of older adult in China keeps growing, the degree of aging is becoming increasingly serious and the health of older adults is a growing concern. Comparing the personal characteristics and health levels of urban and rural older adults and determining the relationship between these factors are of great significance in maintaining their health. In addition, exploring how these relationships differ between urban and rural areas is important.

Method

This study conducted a literature review to examine the impact of various factors on the physical and mental health of older adults in urban and rural areas in China. Moreover, based on cross-sectional data from the 2017 Chinese General Social Survey (CGSS), urban-rural differences in the factors' degree of influence on the perceived health of older adults were studied using multiple logistic regression.

Results

Regular physical exercise had a powerful protective effect on urban older adults' physical and mental health, whereas regular participation in social activities had a positive impact on rural older adults' health. Low income, low educational level, low social trust, lack of a partner, and having more than one child negatively affected the physical health of rural older people. Low socioeconomic status had a negative impact on rural people's health both in mind and body. Overall, the rural adults' health status was found to be relatively low and deserves more attention.

Conclusion

This study demonstrated that older people's physical and mental health levels can be significantly affected by the frequency of daily activities and individual and family characteristics. Furthermore, urban-rural differences were observed. These findings could provide feasible suggestions for governments, communities, and older adults' family members to help alleviate health inequality.

Longitudinal associations between social relationships and cognitive function among Chinese older adults: The mediating role of healthy lifestyles

BACKGROUND

We aimed to explore whether social relationships and cognitive function were reciprocally related and whether healthy lifestyles mediate their association.

METHODS

This study included 3372 Chinese adults from the years 2014-2018 wave of the Chinese Longitudinal Healthy Longevity Survey.

RESULTS

Baseline social relationships were negatively associated with a change in cognitive function (β = -0.030, p = 0.043). Participants with a 1 standard deviation (SD) increase in social relationships had an approximately 6% reduced risk of developing cognitive impairment. However, baseline cognitive function did not independently predict social relationships. The association between △social relationships and △cognitive function was partially mediated by △a healthy lifestyle (B = 0.025, 95% CI = 0.013-0.041).

CONCLUSIONS

The association between social relationships and cognitive function may be unidirectional. Policies that promote cognitive function based on social relationships would benefit by taking into account lifestyle factors.

Association between chronic diseases and depression in the middle-aged and older adult Chinese population-a seven-year follow-up study based on CHARLS

Background

With the aging of the Chinese population, the prevalence of depression and chronic diseases is continually growing among middle-aged and older adult people. This study aimed to investigate the association between chronic diseases and depression in this population.

Methods

Data from the China Health and Retirement Longitudinal Study (CHARLS) 2011-2018 longitudinal survey, a 7-years follow-up of 7,163 participants over 45 years old, with no depression at baseline (2011). The chronic disease status in our study was based on the self-report of the participants, and depression was defined by the 10-item Center for Epidemiologic Studies Depression Scale (CES-D-10). The relationship between baseline chronic disease and depression was assessed by the Kaplan-Meier method and Cox proportional hazards regression models.

Results

After 7-years follow-up, 41.2% (2,951/7163, 95% CI:40.1, 42.3%) of the participants reported depression. The analysis showed that participants with chronic diseases at baseline had a higher risk of depression and that such risk increased significantly with the number of chronic diseases suffered (1 chronic disease: HR = 1.197; 2 chronic diseases: HR = 1.310; 3 and more chronic diseases: HR = 1.397). Diabetes or high blood sugar (HR = 1.185), kidney disease (HR = 1.252), stomach or other digestive diseases (HR = 1.128), and arthritis or rheumatism (HR = 1.221) all significantly increased the risk of depression in middle-aged and older adult Chinese.

Conclusion

The present study found that suffering from different degrees of chronic diseases increased the risk of depression in middle-aged and older adult people, and these findings may benefit preventing depression and improving the quality of mental health in this group.

The longer-term impact of the COVID-19 pandemic on wellbeing and subjective cognitive functioning of older adults in Belgium

In earlier survey research, we observed a severe impact of the first peak of the COVID-19 pandemic on the subjective wellbeing, sleep and activity of adults aged 65 years or older in Flanders, Belgium. The impact on subjective cognitive functioning, however, was limited. Since then, periods of lockdown and periods with less strict regulations alternated, but social distancing remained, especially for older adults. To study the longer-term impact of the pandemic on wellbeing and subjective cognitive functioning, we re-assessed the older adults from the first measurement moment (May-June 2020) in a second (June-July 2020) and third (December 2020) wave of the survey (n = 371, M = 72 years old, range 65-97 years old). Results indicated that wellbeing fluctuated with the severity of the pandemic. Results for self-reported cognitive functioning were mixed. While participants indicated a slightly better general subjective cognitive functioning at the end of the study, experienced problems with most cognitive subdomains significantly increased over time. The presence of depressive and anxiety symptoms were related to the longer-term impact of the pandemic on wellbeing and subjective cognitive functioning. Our study shows the long-lasting impact of the pandemic on the wellbeing and subjective cognitive functioning of older adults, without full recovery from the first wave.

The Associations of Loneliness and Social Support with Cognitive Impairment among Middle-Aged and Older Individuals with Diabetes

Diabetes mellitus is a chronic disease with significant morbidity and mortality and it is associated with poor cognitive performance in later life. This study seeks to determine the relationship between social support and cognitive function among participants with type 2 diabetes mellitus (T2DM). We used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, including participants with T2DM aged 45 and older (n = 4821). We examined different aspects of perceived social support, measured as structural social support (e.g., marital status), functional social support (having a caregiver in case of sickness or disability), and loneliness. We examined cognitive functioning using a six-item screener. Our results indicate that adults who felt lonely for 5-7 days per week had almost double the odds of cognitive impairment compared to those who didn't feel lonely. These results suggest that among middle-aged and older individuals with T2DM, interventions targeting lonely adults and which aim to reduce loneliness may combat some of the risks of cognitive decline.

A Tutorial for Speech-Language Pathologists: Physical Activity and Social Engagement to Prevent or Slow Cognitive Decline in Older Adults

PURPOSE

This tutorial provides an overview of two behavioral approaches, physical activity and social engagement, to prevent or slow cognitive decline in older adults and to increase awareness in the field of speech-language pathology of the important role that speech-language pathologists (SLPs) play in an interprofessional team working with this population.

METHOD

A review of exercise science, neuroscience, and social science literature was used to synthesize evidence and to outline the impact of physical activity and social engagement on cognition. The following topics were explored: How do exercise and social engagement support cognition? What are modifiable risk factors of dementia? What is the impact of inactivity and isolation on cognition? What is the potential role of the SLP on an interprofessional team focusing on preventive measures for cognitive decline? What is the impact of physical exercise and social engagement on nursing home residents?

RESULTS

Research increasingly points to the critical importance of physical activity and social engagement to prevent cognitive decline in normal aging and to slow cognitive decline associated with mild cognitive impairment and dementia. Research suggests that physical activity maintains or improves memory, attention, executive function, visuospatial function, speed of processing, and general cognitive function. Social engagement has been found to maintain and improve general cognitive function.

CONCLUSIONS

Behavioral interventions are an effective strategy to prevent or slow cognitive decline in the older adult population. SLPs have a role to play on an interprofessional team that works to prevent cognitive decline. By considering factors that play a role in the prevention of cognitive decline, such as physical activity and social engagement, the quality of life and overall health of older adults can be improved. Areas of improvement include memory, attention, executive function, visuospatial function, speed of processing, and general cognitive function.

A Decade Later on How to "Use It" So We Don't "Lose It": An Update on the Unanswered Questions about the Influence of Activity Participation on Cognitive Performance in Older Age

Activity engagement is a modifiable factor that has been widely-cited as being good for the aging brain and cognition and represents a valuable target for reducing dementia risk. However, specific issues about activity engagement (mental, social, and physical) and cognition in older adulthood remain, and Bielak [Gerontology 2010;56: 507-519] reviewed seven major methodological and theoretical questions about this relationship. We present an updated reflection on these key questions, focusing on research published in the last 10 years. For some questions, a significant amount of work has been done and conclusions have become clearer; for others, there have been few additions to the literature and our knowledge remains much the same as it was a decade ago. We review the issues identified in the 2010 paper including the directionality and temporal nature of the relationship; whether specific activity domains offer different benefits to cognition and what domain(s) of cognition are affected; variation in the relation by age, gender, or education; potential mechanisms involved; and how activity engagement is assessed. For each, we present the most up-to-date research, discuss remaining challenges and possible future directions. This formal unifying of the information in the field is intended as a guide to support continued progress by spurring on studies addressing specific questions while reminding researchers of critical issues. We conclude with recommendations that future studies investigating the link between activity engagement and cognitive performance in adulthood should consider.

How the COVID-19 Pandemic Has Impacted Daily Life? Assessing the Use of Web Resources for Recreational Activities in the Italian Adult Population

Restriction measures imposed during the COVID-19 pandemic led to changes in people's lives and behaviors. The aim of this paper is to assess the changes occurred in physical activity (PA), sleep, social and cultural activities and personal relationships of Italian adults during the pandemic and to evaluate the use of web-based resources to continue these activities. To this purpose, a cross-sectional study using a web-based questionnaire was carried out and both descriptive and regression analysis was performed. On a total of 1831 participants (61% females, age 18-93 years), the majority reported a decrease in PA, sleep, social and cultural activities and personal relationships, since the beginning of the pandemic. Sleep was notably affected by the use of new technologies. The regression analysis demonstrated that the use of web-based media for doing exercise was associated with being younger than 50 years and female; having a chronic condition was inversely related with the use of web resources for social and cultural activities and to maintain relationships; being employed was negatively related with the use of web media for continuing personal relationships and cultural activities; and being vaccinated against COVID-19 was positively associated with the use of the web for personal relationships. These findings confirm that the COVID-19 pandemic notably affected the daily life of Italian adults. Our results suggest that the use of technology to deal with these changes seems to be related with certain sociodemographic and health-related characteristics. These findings can be useful to identify those characteristics that can help people in copying with daily life modifications due to restriction measures.

Accelerometer-Assessed Physical Activity and Cognitive Performance among European Adults Aged 50+: The Mediating Effects of Social Contacts and Depressive Symptoms

Background: Cognitive decline is a major public health concern worldwide and it is vital to identify and better understand effective population-based means to improve cognitive performance in old age. The current study set out to examine the links between accelerometer-based physical activity with cognitive performance in later life, as well the indirect pathways through one’s social network contacts and depression. Method: We used data from 855 participants aged 50 and above who took part in a cross-sectional accelerometer study as part of the Survey of Ageing, Retirement and Health (SHARE). Cognitive function was measured as an average score of fluency, immediate and delayed recall tests, social contacts were the average contact frequency with members of the social support network, and depression was the Euro-D summary score of depressive symptoms. A multiple mediation analysis was conducted to test the direct and indirect associations between total physical activity (intensity gradient) and cognitive function, as well as the mediation of this association by social contacts and depressive symptoms. Results: Intensity of physical activity was directly related to better cognitive performance (B = 0.170, p = 0.007). The association was partially mediated by social contacts (B = 0.022, 95% CI 0.005, 0.046) and depressive symptoms (B = 0.009, 95% CI 0.009, 0.025), such that total physical activity was linked to cognitive health via more frequent contacts with network members and low depressive symptoms. Conclusions: Practitioners might consider encouraging a physically active lifestyle that involves social interactions to support better cognitive aging and mental health.

Social Interaction, Lifestyle, and Depressive Status: Mediators in the Longitudinal Relationship between Cognitive Function and Instrumental Activities of Daily Living Disability among Older Adults

(1) Background: Cognitive decline is associated with instrumental activities of daily living (IADL) disability. Intervention targeting the mediators of this association will provide a path to avoid cognition-related IADL disability. (2) Methods: This study used data of wave 2008 (baseline) and wave 2014 of Chinese Longitudinal Healthy Longevity Surveys. Structural equation modeling was conducted to examine the mediating effect of social interaction, lifestyle (fruit and vegetable intake; exercise habits), and depressive status on the association between four baseline cognitive function dimensions (measured by the Chinese version of the Mini-Mental State Examination) and five (2014) IADL dimensions (visiting neighbors, shopping, preparing meals, washing clothes, and taking public transportation). (3) Results: Among 1976 older adults, 29.1% developed IADL disability 6 years later. The cognition−disability association was completely mediated by social interaction (estimate = −0.095, p < 0.001), lifestyle (estimate = −0.086, p < 0.001), and depressive status (estimate = −0.017, p = 0.003). The mediating effects of social interaction (46.3% variances explained) and lifestyle (42.0% variances explained) were both larger than that of depressive status (8.3% variances explained). (4) Conclusions: The development of interventions aimed at improving social interaction, depression, and lifestyle could be of value to prevent cognition-related IADL disability.

A prospective association between tooth status and cognitive performance among older adults in Europe

OBJECTIVES

This study set out to examine both the longitudinal association between tooth status and cognitive performance among older adults in Europe, and the mediating effects of loneliness and quality of life on this association.

METHODS

We conducted a prospective analysis using data from 38,614 participants aged 50 or older, taken from the Survey of Health, Ageing and Retirement in Europe (SHARE) of 2013 (baseline) and 2015 (follow up). Bootstrapping with resampling strategies was used for testing a multiple mediator model.

RESULTS

The average age of participants was 66.9 (SD = 9.4). About 23% of the participants had full sets of their own teeth and 38.2% had missing teeth fully replaced by dental implants or dentures. Participants who had partially replaced teeth (B = 0.038, p < 0.001), and with fully replaced teeth (B = 0.041, p < 0.001), or had all their teeth in place (B = 0.055, p < 0.001), had better cognitive performance compared to those who did not replace their missing teeth. It was also found that quality of life and loneliness partially mediated these relationships - Having all teeth in place or replacing all or partially missing teeth was found to affect cognitive performance also via improved quality of life and through lower loneliness.

CONCLUSION

In later life, poor tooth status can be directly associated with cognitive decline and indirectly linked to cognitive performance, in light of decreasing quality of life and increasing loneliness. Clinicians should be aware of both the impact of poor tooth status on cognitive status and the implications for the wellbeing of older adults.

Heterogeneity in Alzheimer's Disease Diagnosis and Progression Rates: Implications for Therapeutic Trials

The clinical presentation and the pathological processes underlying Alzheimer's disease (AD) can be very heterogeneous in severity, location, and composition including the amount and distribution of AB deposition and spread of neurofibrillary tangles in different brain regions resulting in atypical clinical patterns and the existence of distinct AD variants. Heterogeneity in AD may be related to demographic factors (such as age, sex, educational and socioeconomic level) and genetic factors, which influence underlying pathology, the cognitive and behavioral phenotype, rate of progression, the occurrence of neuropsychiatric features, and the presence of comorbidities (e.g., vascular disease, neuroinflammation). Heterogeneity is also manifest in the individual resilience to the development of neuropathology (brain reserve) and the ability to compensate for its cognitive and functional impact (cognitive and functional reserve). The variability in specific cognitive profiles and types of functional impairment may be associated with different progression rates, and standard measures assessing progression may not be equivalent for individual cognitive and functional profiles. Other factors, which may govern the presence, rate, and type of progression of AD, include the individuals' general medical health, the presence of specific systemic conditions, and lifestyle factors, including physical exercise, cognitive and social stimulation, amount of leisure activities, environmental stressors, such as toxins and pollution, and the effects of medications used to treat medical and behavioral conditions. These factors that affect progression are important to consider while designing a clinical trial to ensure, as far as possible, well-balanced treatment and control groups.

Volunteering and health: The role of social network change

OBJECTIVES

Levels of volunteering may differentially influence multiple dimensions of health among older adults. Further, increasing evidence indicates social networks represent critical bridging and bonding contexts for the volunteering-health link. This study examines two research questions: 1) does volunteering level (low, moderate, high) influence physical and mental health in the same ways? And 2) does social network change moderate this link?

METHODS

Data come from Waves 1 and 2 of the longitudinal Social Relations Study (n = 556) collected in 1992 and 2005 and the sub-sample of adults age 50 and older at Wave 2. Regression analyses predicting self-rated health and depressive symptoms were conducted to examine main effects of volunteering and moderating effects of social network change.

RESULTS

Volunteering at a moderate level (101-300 hours per year) was associated with fewer depressive symptoms compared to those not volunteering. Social network change moderated the association between volunteering and self-rated health. Among those reporting a decrease in the proportion of non-family in their network (decrease in bridging), a moderate level of volunteering was associated with better self-rated health.

CONCLUSION

While moderate levels of volunteering are associated with better mental health, the link to physical health is only present in the context of decreasing network bridging. Identifying specific circumstances under which volunteering is beneficial is critical for developing interventions to promote health for all, including those in mid and later life.

Understanding community-dwelling Chinese older adults' engagement in physical activity: A grounded theory study

BACKGROUND AND OBJECTIVE

Limited information is available on the process of Chinese older adults' initiation, engagement, and maintenance of physical activity (PA), thus limiting the development of effective PA promotion programs. The purpose of the study was to investigate Chinese old adults' perspectives and experiences with PA engagement and to develop a conceptual model illustrating the process of how community-dwelling Chinese older adults engage in PA.

RESEARCH DESIGN AND METHODS

This study used grounded theory methodology. Nineteen community-dwelling Chinese older adults age over 60 years participated. We conducted semi-structured in-depth interviews with participants. Open, axial, and selective coding, along with constant comparative analysis was performed to analyze the data.

RESULTS

Participants described PA engagement as a complex and dynamic process, consisting of three stages: Getting started, Participating in PA, and Making PA Part of Life. The transition from one stage to the next was driven by an increasing internalized motivation towards PA through Seeing benefits. Many participants described that Staying in Groups was a key strategy for them to keep physically active. Moreover, Restructuring occurred when Chinese older adults encountered trigger situations.

DISCUSSION AND IMPLICATIONS

This study identified the stages of how community-dwelling Chinese older adults engage in to perform and maintain PA. The developed conceptual model can inform future interventions for promoting PA among Chinese older adults.

Social network type and subsequent cognitive health among older Europeans

OBJECTIVES

One's personal social network constitutes a contextual framing factor for late-life cognitive function. This study examined the association between network type at baseline and changes in three cognitive measures: immediate recall, delayed recall, and fluency, two years hence, among Europeans aged 50 and older.

PARTICIPANTS

Data were taken from Waves four and five of the Survey of Health, Ageing, and Retirement in Europe of adults aged 50 and above (N = 50,071).

MEASUREMENTS

The latent class analysis was applied to a set of criterion variables. The procedure yielded five distinct network types: multi-tie (6%), family-rich (23%), close-family (49%), family-poor (12%), and friend-enhanced (10%). The network types were then regressed on the cognition measures at follow-up, controlling for the respective baseline cognition scores, as well as for age, gender, education, self-rated health, mobility difficulty, and country.

RESULTS

Respondents in family-poor network types had poorer cognition scores at follow-up, compared to those in the modal close-family network, while those in multi-tie networks had consistently better scores. The family-rich network and the friend-enhanced network also had a somewhat better cognitive function.

CONCLUSIONS

Having varied sources of network ties, e.g. friendship ties and/or several types of family relationships, is beneficial to the cognitive health of older adults over time. Networks based mainly on ties with relatives other than spouse and children, on the other hand, have poorer cognitive outcomes. Older people in this latter group face an increased risk for cognitive decline and should receive assistance in enhancing their interpersonal environments.