Volunteering, polygenic risk for Alzheimer's disease, and cognitive functioning among older adults

Does volunteering reduce epigenetic age acceleration among retired and working older adults? Results from the Health and Retirement Study

OBJECTIVES

The current study aims to explore the relationship between the frequency of volunteering and biological aging, as measured by epigenetic age acceleration. It also investigates whether this relationship differs between retired and working older adults. Understanding this connection could inform interventions promoting healthy aging and reducing age-related chronic health conditions.

METHOD

Data were derived from the Health and Retirement Study (HRS), including pre-treatment covariates (2012), volunteer frequency and work status (2014), and five DNA methylation measures (2016) (N = 2,605). Generalized linear models were estimated to examine the relationship between volunteering and epigenetic age acceleration, stratified by retirement status. The analyses adjusted for relevant covariates and utilized energy balancing weights to account for selection into volunteering.

RESULTS

Findings show that volunteering, especially for 1-49 h per year and 200+ hours per year, was linked to less epigenetic age acceleration, with significant effects on DNA methylation measures PhenoAge, GrimAge, and DunedinPACE clocks. Among retired individuals, moderate volunteering was significantly associated with decelerated epigenetic age acceleration, indicating greater benefits for retirees compared to working individuals.

CONCLUSIONS

The study found that frequent volunteering may lead to decelerated epigenetic aging, potentially offering a public health intervention to enhance health and quality of life among older adults. Further research is needed to confirm these findings and to understand how volunteering might differentially impact retired and working individuals. Such insights could guide the development of targeted strategies to promote healthy aging and address age-related health disparities.

The Effects of High versus Low Levels of Altruism and Volunteering on the 4-Year Follow-Up Cognitive Performance of Community-Dwelling Older Adults

OBJECTIVES

Currently, there is a growing interest on the benefits of volunteering. Nevertheless, there is scarce evidence for non-volunteering altruistic behaviors. This study aims to investigate the role of both altruism and volunteering on the cognitive performance of older individuals followed for four years.

METHODS

This was cohort study carried out in 180 Brazilian older adults assessed in three different timepoints (baseline [2015-2016], 2 years of follow-up [2017-2018] and 4 years of follow-up [2019-2020]). Composite cognitive score was calculated based on the Mini-Mental State Examination, Verbal Fluency, Clock-Drawing test, and CERAD Word-List. Altruism was assessed through the Self-reported Altruism Scale and self-reported volunteering status. Mixed ANCOVAS were performed.

RESULTS

For altruism, there were significant differences in all time points (Baseline, 2 years and 4 years) favoring higher cognitive scores for higher levels of altruism. However, no differences were observed for volunteering in all time points.

CONCLUSIONS

Having higher levels of altruism was significantly associated with better cognitive scores.

CLINICAL IMPLICATIONS

Altruism, even without volunteering, seem to have positive effects on the cognitive functioning of older adults. Health professionals who take care of older adults might take account of the presence or absence of altruistic behaviors of their patients in their formulations and recommendations.

Cognitive reserve in the recovery and rehabilitation of stroke and traumatic brain injury: A systematic review

Objective: Cognitive reserve (CR) is the brain's ability to cope with changes related to aging and/or disease. Originally introduced to explain individual differences in the clinical manifestations of dementia, CR has recently emerged as a relevant construct in stroke and traumatic brain injury (TBI). This systematic review aims to investigate whether CR could predict post-stroke and TBI clinical recovery and rehabilitation outcomes, and how different variables used to estimate CR (i.e., proxies) are related to the prognosis and effectiveness of rehabilitation in these clinical populations. Method: A search was made in Pubmed, Embase, and PsycInfo for articles published until 12 January 2023, following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) protocol guidelines. Results: 31 studies were included after completing all screening stages. Overall, results show that a higher CR was associated with a better prognosis and a more effective rehabilitation in most of the clinical aspects considered: cognitive functioning, functional, occupational, and socio-emotional abilities, as well as psychiatric and neurological scales. Conclusions: A higher CR seems to be associated with a more favorable prognosis and a better rehabilitation outcome after stroke and TBI. Results suggest that CR should be taken into account in clinical practice to make more accurate predictions about recovery and effectiveness of rehabilitation. However, some inconsistencies suggest the need for further investigations, possibly using multiple proxies for CR.

The relationship between volunteering and cognitive performance in older adults: A systematic review

OBJECTIVES

This systematic review aims to examine the relationship between cognition and volunteering in older adults, with a specific focus on domain-specific outcomes.

METHODS

In April 2023, a comprehensive search was conducted across multiple electronic databases including PubMed, Google Scholar, ScienceDirect, Web of Science, and Scopus. The inclusion criteria for the study were limited to longitudinal studies or randomized controlled trials (RCTs). The quality and risk of bias of the included articles were assessed using the Newcastle-Ottawa Scale and Consolidated Standards of Reporting Trials (CONSORT).

RESULTS

Out of 3575 articles retrieved, 17 studies were eligible for inclusion in this review. The majority of these studies were conducted in high-income countries. Of the 17 studies reviewed, 16 found a positive association between volunteering and cognitive benefits.

CONCLUSION

The analysis of seventeen studies meeting the predefined inclusion criteria suggests a potential positive correlation between volunteering and cognitive function among older adults. Some demographic factors such as gender and education level were observed to have an influence on this relationship. It was found that older adults who engage in volunteering may exhibit better episodic memory, working memory, and verbal fluency compared to non-volunteers. However, due to limitations in the existing research and variations across studies, further investigation is needed to establish definitive conclusions.

The Concept of Prosociality in Later Life and Its Dimensions: A Scoping Review

Objective: The aim of this study was to clarify various aspects and dimensions of the prosociality concept in later life as an important concept that gains significance in people as they age. This concept has been expressed through a variety of dimensions in different studies. Method : This is a scoping review of the relevant literature on the concept of prosociality and its dimensions in later life, including quantitative and qualitative studies. The required data were collected from Web of Science, Scopus, PubMed, ProQuest, and Google Scholar databases between the years 1987 and 2022. Results: First, 877 articles were identified, and after the screening phase, 57 eligible studies were reviewed. Two main categories, prosocial dispositions and prosocial behaviors, and seven subcategories were extracted. The subcategories of prosocial dispositions include empathy, prosocial norms, innate tendencies, and generative desires. Prosocial behaviors subcategories include informal spontaneous helping, formal planned helping, and pro-environmental behaviors. Conclusion: The various aspects and dimensions of the prosociality concept in later life identified in this study can be used as a basis for assessing and planning the promotion of prosociality among older adults.

Evaluation of the Polygenic Risk Score for Alzheimer's Disease in Russian Patients with Dementia Using a Low-Density Hydrogel Oligonucleotide Microarray

The polygenic risk score (PRS), together with the ɛ4 allele of the APOE gene (APOE-ɛ4), has shown high potential for Alzheimer's disease (AD) risk prediction. The aim of this study was to validate the model of polygenic risk in Russian patients with dementia. A microarray-based assay was developed to identify 21 markers of polygenic risk and ɛ alleles of the APOE gene. This case-control study included 348 dementia patients and 519 cognitively normal volunteers. Cerebrospinal fluid (CSF) amyloid-β (Aβ) and tau protein levels were assessed in 57 dementia patients. PRS and APOE-ɛ4 were significant genetic risk factors for dementia. Adjusted for APOE-ɛ4, individuals with PRS corresponding to the fourth quartile had an increased risk of dementia compared to the first quartile (OR 1.85; p-value 0.002). The area under the curve (AUC) was 0.559 for the PRS model only, and the inclusion of APOE-ɛ4 improved the AUC to 0.604. PRS was positively correlated with tTau and pTau181 and inversely correlated with Aβ42/Aβ40 ratio. Carriers of APOE-ɛ4 had higher levels of tTau and pTau181 and lower levels of Aβ42 and Aβ42/Aβ40. The developed assay can be part of a strategy for assessing individuals for AD risk, with the purpose of assisting primary preventive interventions.

Adults Older Than Age 55 Engage in Less Diverse Activities Than Those 18 Years Ago

OBJECTIVES

Life-span perspectives have long acknowledged that individual functioning is shaped by historical and sociocultural contexts. Secular increases favoring recent cohorts are widely documented. However, little is known about secular trends in day-to-day activities and whether historical changes have occurred in younger and older adults alike.

METHODS

We compared data from 2 independent cohort samples of the daily diary portion of the Midlife in the United States Study obtained 18 years apart (1995/1996 cohort: n = 1,499 vs 2013/2014 cohort: n = 782) and identified case-matched cohorts (n = 757 per cohort) based on age, gender, education, and race. An activity diversity score was calculated based on 7 common daily activities, using Shannon's entropy method. We additionally examined the roles of age and other sociodemographic and health characteristics in cohort differences in activity diversity.

RESULTS

Results revealed that the 2013/2014 cohort experienced lower daily activity diversity than the 1995/1996 cohort. Age was positively associated with activity diversity in the 1995/1996 cohort, whereas age was negatively associated with activity diversity in the 2013/2014 cohort. These associations were significant for those who were older than age 55. Cohorts also differed in the types of most dominant activities and average time spent on those activities.

DISCUSSION

Findings show changes in the lifestyles and daily activities of U.S. adults across 2 decades. Contrasting to the common belief that today's adults may be healthier and more active, they seem engaging in less diverse daily activities, which can be a risk for future health outcomes.

Volunteering and Changes in Cardiovascular Biomarkers: Longitudinal Evidence From the Health and Retirement Study

Background and Objectives

Growing body of research shows that volunteering is beneficial for those served, the volunteers, and the larger communities. However, major challenges remain that hinder the practical implications for volunteer activity as a public health intervention, including potential selection effects, lack of longitudinal studies that adjust for baseline characteristics, and a paucity of studies that consider multiple physical health outcomes in a single model.

Research Design and Methods

Data from 2006 to 2016 waves of the Health and Retirement Study (2006-2016) were used (N = 18,847). Outcome-wide analyses were utilized to evaluate if changes in volunteering between 2006/2008 (t0) and 2010/2012 (t1) were associated with 7 cardiovascular disease biomarkers 4 years later (2014/2016, t2). These models were adjusted for demographic factors, socioeconomic status, health behaviors, chronic conditions, baseline biomarkers, and volunteering. Additionally, selection into volunteering and attrition were taken into account.

Results

Compared with nonvolunteers, volunteering more than 200 hr a year was associated with a lower risk for clinically high diastolic blood pressure. In addition, increased volunteering effort (change from 1 to 99 hr at t0 to >100 hr at t1) was associated with a lower likelihood of clinically high systolic and diastolic blood pressure levels. Sustained high volunteering (>100 hr at both t0 and t1) was associated with lower diastolic blood pressure.

Discussion and Implications

The current study adds to the evidence on the health benefits of volunteering for adults 50 and older by inferring a potential causal link between high-intensity volunteering and reduced blood pressure.

Modern Approaches to the Diagnosis of Cognitive Impairment and Alzheimer's Disease: A Narrative Literature Review

BACKGROUND

The aging of the worlds population leads to an increase in the prevalence of age-related diseases, including cognitive impairment. At the stage of dementia, therapeutic interventions become usually ineffective. Therefore, researchers and clinical practitioners today are looking for methods that allow for early diagnosis of cognitive impairment, including techniques that are based on the use of biological markers.

AIM

The aim of this literature review is to delve into scientific papers that are centered on modern laboratory tests for Alzheimers disease, including tests for biological markers at the early stages of cognitive impairment.

METHODS

The authors have carried out a descriptive review of scientific papers published from 2015 to 2023. Studies that are included in the PubMed and Web of Science electronic databases were analyzed. A descriptive analysis was used to summarized the gleaned information.

RESULTS

Blood and cerebrospinal fluid (CSF) biomarkers, as well as the advantages and disadvantages of their use, are reviewed. The most promising neurotrophic, neuroinflammatory, and genetic markers, including polygenic risk models, are also discussed.

CONCLUSION

The use of biomarkers in clinical practice will contribute to the early diagnosis of cognitive impairment associated with Alzheimers disease. Genetic screening tests can improve the detection threshold of preclinical abnormalities in the absence of obvious symptoms of cognitive decline. The active use of biomarkers in clinical practice, in combination with genetic screening for the early diagnosis of cognitive impairment in Alzheimers disease, can improve the timeliness and effectiveness of medical interventions.

Area-Level Infant Mortality Exposure in Early Life and Alzheimer's Disease Mortality: Examining Variation Based on Age, Sex, and Place of Birth

BACKGROUND

Growing evidence suggests that critical periods in early life may contribute to one's risk of Alzheimer's disease and related dementias (ADRD) in later life. In this paper we explore the role that exposure to infant mortality plays in later life ADRD.

OBJECTIVE

To determine if exposure to early life infant mortality is associated with later mortality from ADRD. Also, we explore how these associations differ by sex and age group, along with the role of state of birth and competing risks of death.

METHODS

We use a sample of over 400,000 individuals aged 50 and above with the NIH-AARP Diet and Health Study with mortality follow-up, allowing us to examine how early life infant mortality rates along with other risk factors play in one's individual mortality risk.

RESULTS

We show that infant mortality rates are associated with death from ADRD among those under 65 years of age, but not those over 65 at baseline interview. Moreover, when factoring in competing risks of death, the associations are relatively unchanged.

CONCLUSION

These results suggest that those exposed to worse adverse conditions during critical periods increase their likelihood of death from ADRD earlier than average, due to that exposure increasing their susceptibility to develop illness later on in life.

Does Voluntary Work Contribute to Cognitive Performance? - An International Systematic Review

Introduction

There is a need for knowledge on activities that can reduce cognitive decline and dementia risk. Volunteering is a productive activity that entails social, physical, and cognitive functions. Therefore, volunteering could be a protective factor for cognitive loss. Thus, this review aims to examine the associations between volunteering and volunteers' cognition and to identify influencing variables.

Methods

Six international literature databases were searched for relevant articles published between 2017 and 2021 (ALOIS, CENTRAL, CINAL, Embase, PsycINFO, PubMed). Quantitative studies of all study designs were included. The primary outcome was the volunteers' cognition measured by objective, internationally established psychometric function tests. Two authors independently assessed the eligibility and quality of the studies. A narrative synthesis was performed using all studies included in this review. The methodology was in line with the PRISMA guidelines.

Results

Fourteen studies met the inclusion criteria and were included. Seven of the included studies confirmed that volunteering positively affects the volunteers' cognitive function. Two other studies identified an association between volunteer activity and volunteers' cognition using cross-sectional measurements. In particular, women and people with a low level of education benefit from the positive effects and associations. The study quality of the included articles was moderate to weak.

Discussion

Our review suggests that volunteering can improve volunteers' cognition. Unfortunately, little attention is given to specific volunteer activities and the frequency of engagement. Additionally, more attention is needed on various risk factors of cognitive impairment.

"Our focus is on illness and loneliness": Volunteer work engagement, compassion satisfaction, compassion fatigue, self-care and motivations to volunteer

They are participating as a volunteer implies active personal positioning accompanying others. Evidence supports that experiences of those who experience an illness, who are hospitalised or feel lonely, impact the volunteers: positive emotions like engagement and Compassion Satisfaction (CS) or, the reverse, Compassion Fatigue (CF). Motivations help us understand why volunteers spend their time on these activities. And self-care practices will be a challenge to counteract the exhausting emotions of volunteering. This research presents a mixed, exploratory and sequential design study on the island of Majorca (Spain). The first phase (n = 216) was quantitative, gathering data from November 2018 to April 2019. Then, the second phase (two focus groups) started with qualitative data collection (July 2019). Firstly, the study determines CS and work engagement levels and examines the relationship between self-care, CF and motivations. Secondly, the study finds out how they recognise their positive and negative emotions, their relationship with self-care and what motivates them to be volunteers. The results show that the volunteers report highly positive feelings associated with their volunteering (CS and engagement) and are backed up by a good level of personal Self-Care. The Understanding and Enhancement motivational functions generate even more positive feelings for the volunteers themselves, who attach a positive value to their experience of caring for others. Despite the positive results collected, we must not ignore the phenomenon of CF in relational volunteering and pain support because it occurs. After all, that could lead to abandonment by volunteers.

Markers of kidney function, genetic variation related to cognitive function, and cognitive performance in the UK Biobank

BACKGROUND

Chronic kidney disease has been linked to worse cognition. However, this association may be dependent on the marker of kidney function used, and studies assessing modification by genetics are lacking. This study examined associations between multiple measures of kidney function and assessed effect modification by a polygenic score for general cognitive function.

METHODS

In this cross-sectional study of up to 341,208 European ancestry participants from the UK Biobank study, we examined associations between albuminuria and estimated glomerular filtration rate based on creatinine (eGFRcre) or cystatin C (eGFRcys) with cognitive performance on tests of verbal-numeric reasoning, reaction time and visual memory. Adjustment for confounding factors was performed using multivariate regression and propensity-score matching. Interaction between kidney function markers and a polygenic risk score for general cognitive function was also assessed.

RESULTS

Albuminuria was associated with worse performance on tasks of verbal-numeric reasoning (β(points) = -0.09, p < 0.001), reaction time (β(milliseconds) = 7.06, p < 0.001) and visual memory (β(log errors) = 0.013, p = 0.01). A polygenic score for cognitive function modified the association between albuminuria and verbal-numeric reasoning with significantly lower scores in those with albuminuria and a lower polygenic score (p = 0.009). Compared to participants with eGFRcre ≥ 60 ml/min, those with eGFRcre < 60 ml/min had lower verbal-numeric reasoning scores and slower mean reaction times (verbal numeric reasoning β = -0.11, p < 0.001 and reaction time β = 6.08, p < 0.001 for eGFRcre < 60 vs eGFRcre ≥ 60). Associations were stronger using cystatin C-based eGFR than creatinine-based eGFR (verbal numeric reasoning β = -0.21, p < 0.001 and reaction time β = 11.21, p < 0.001 for eGFRcys < 60 vs eGFRcys ≥ 60).

CONCLUSIONS

Increased urine albumin is associated with worse cognition, but this may depend on genetic risk. Cystatin C-based eGFR may better predict cognitive performance than creatinine-based estimates.

The health advantage of volunteering is larger for older and less healthy volunteers in Europe: a mega-analysis

There is a vast literature on the health benefits associated with volunteering for volunteers. Such health advantages are likely to vary across groups of volunteers with different characteristics. The current paper aims to examine the health advantages of volunteering for European volunteers and explore heterogeneity in the association between volunteering and health. We carry out a mega-analysis on microdata from six panel surveys, covering 952,026 observations from 267,212 respondents in 22 European countries. We provide open access to the code we developed for data harmonization. We use ordinary least squares, fixed effects, first difference, and fixed effect quantile regressions to estimate how volunteering activities and changes therein are related to self-rated health for different groups. Our results indicate a small but consistently positive association between changes in volunteering and changes in health within individuals. This association is stronger for older adults. For respondents 60 years and older, within-person changes in volunteering are significantly related to changes in self-rated health. Additionally, the health advantage of volunteering is larger for respondents in worse health. The advantage is largest at the lowest decile and gradually declines along the health distribution. The magnitude of the association at the first decile is about twice the magnitude of the association at the ninth decile. These results suggest that volunteering may be more beneficial for the health of specific groups in society. With small health advantages from year to year, volunteering may protect older and less healthy adults from health decline in the long run.

Altruism, Volunteering and Cognitive Performance Among Older Adults: A 2-Year Longitudinal Study

This study aims to investigate whether altruism and volunteering are associated differently with cognitive functioning in community-dwelling older adults. A 2-year longitudinal study of 291 Brazilian older adults was conducted. In the baseline analysis, altruism, but not volunteering, was associated with higher scores for the composite cognitive score, the Mini-Mental State Examination, the verbal fluency and the CERAD Recall. Concerning the longitudinal analyses, volunteering at baseline, but not altruism, was associated with verbal fluency and CERAD Word List Recall after 2 years of follow up. Same results were obtained while investigating changes in score. Altruism and volunteering were associated with cognitive tests, albeit in different ways. Volunteering, but not altruism, was associated with lower cognitive decline. However, altruism, but not volunteering, was associated with higher absolute score on these tests. These findings can further understanding of this new field of health research.

The Role of Social Connection/Engagement in Episodic Memory Change in Stroke

BACKGROUND AND OBJECTIVES

Positive associations between social connection/engagement and cognitive function are well documented. However, little is known about whether social connection/engagement can buffer the impact of serious brain injury such as stroke on cognitive functioning.

RESEARCH DESIGN AND METHODS

Participants were 898 individuals with incident stroke from the Health and Retirement Study (HRS) between 1998-2012. Multilevel modeling was used to examine how social connection/engagement were associated with episodic memory pre- and post-stroke. Models controlled for age, gender, education, race/ethnicity, number of health conditions, and functional health.

RESULTS

Participants who were lonely pre-stroke recalled significantly fewer words at time of stroke, and participants who had children residing within 10 miles pre-stroke showed significantly less decline in word recall over time. Participants who provided help to others pre-stroke showed less stroke-related decline in word recall. Within-person increase in partnered status, having friends, and helping others were related to better word recall in the post-stroke period.

DISCUSSION AND IMPLICATIONS

Higher pre-stroke levels of social connection/engagement predicted better episodic memory at stroke, smaller decline in episodic memory with stroke, and less decline in episodic memory over time. Increases in social connection/engagement from pre- to post-stroke also predicted better post-stroke episodic memory. Beyond the widely documented benefits of social connection/engagement to well-being, they may also increase cognitive stimulation and cognitive reserve and thus contribute to stroke recovery in the cognitive domain. Social connection/engagement is an important and modifiable risk factor in older adults.

Polygenic Score Models for Alzheimer's Disease: From Research to Clinical Applications

The high prevalence of Alzheimer's disease (AD) among the elderly population and its lack of effective treatments make this disease a critical threat to human health. Recent epidemiological and genetics studies have revealed the polygenic nature of the disease, which is possibly explainable by a polygenic score model that considers multiple genetic risks. Here, we systemically review the rationale and methods used to construct polygenic score models for studying AD. We also discuss the associations of polygenic risk scores (PRSs) with clinical outcomes, brain imaging findings, and biochemical biomarkers from both the brain and peripheral system. Finally, we discuss the possibility of incorporating polygenic score models into research and clinical practice along with potential challenges.

Volunteer service and positive attitudes toward aging among Chinese older adults: The mediating role of health

OBJECTIVE

Attitude toward aging is an important indicator for measuring the wellbeing of older people, and a vital part of active and healthy aging. We aimed to assess the relationship between volunteer service and attitudes toward aging held by older people and to determine the mediating role of health.

METHOD

We analyzed the data of 10,792 Chinese people over age 60 from the 2014 Chinese Longitudinal Aging Social Survey. We used multiple linear regression models and the two-stage least-squares model to explore the correlation between volunteer service and attitudes toward aging. Furthermore, we applied structural equation modeling to test for mediation effects of different aspects of health.

RESULTS

We found that volunteer service was significantly associated with attitudes toward aging (β = 0.335, p < 0.001), while self-assessed health, physical health, and mental health played a mediating role between volunteer service and attitudes toward aging held by older adults.

CONCLUSIONS

In exploring ways to cope with the challenges brought about by the aging of the population, we found that participating in volunteer services not only improves older people's self-assessed physical, and mental health, but also improves their positive attitudes toward aging. Therefore, under the framework of active and healthy aging, volunteer service and participation in social activities can enhance social vitality and welfare, reduce social burden, and improve quality of life.