Spousal caregiving, widowhood, and cognition: A systematic review and a biopsychosocial framework for understanding the relationship between interpersonal losses and dementia risk in older adulthood

A study on cognitive trajectory changes and predictive factors in middle-aged and older adults individuals with dual sensory impairment based on the health social determinants model

Aim

This study aims to explore the cognitive trajectory changes in middle-aged and older adults individuals with dual sensory impairment (simultaneous visual and hearing impairment) and to identify the predictors of different trajectory changes.

Methods

Based on the longitudinal data from the China Health and Retirement Longitudinal Study (CHARLS) from 2013 to 2020, data from 2,369 middle-aged and older adults individuals with dual sensory impairment were selected. A latent variable growth mixture model was constructed to analyze the cognitive function development trajectories in this population and to identify their predictive factors.

Results

The cognitive function development trajectories in the middle-aged and older adults population can be categorized into three types: high cognitive level stable group, low cognitive level slowly declining group, and moderate cognitive level rapidly declining group. Logistic regression analysis showed that age (OR 30.544; 95% CI 9.35-99.754; p < 0.001), sleep duration (OR 0.559; 95% CI 0.343-0.909; p < 0.005), education (OR 0.009; 95% CI 0.003-0.025; p < 0.001), marital status (OR 2.122; 95% CI 1.457-3.090; p < 0.001), social participation (OR 0.499; 95% CI 0.379-0.658; p < 0.001), place of residence (OR 1.471; 95% CI 1.089-1.988; p < 0.001), and medical insurance (OR 0.353; 95% CI 0.169-0.736; p < 0.005) are predictive factors for cognitive function trajectories in this population.

Conclusion

There is group heterogeneity in the cognitive function development trajectories among middle-aged and older adults individuals with dual sensory impairment. Factors such as less than 4 h of nighttime sleep, low social participation, alcohol consumption, and lack of medical insurance are modifiable risk factors for cognitive decline in this population. Preventive strategies should be formulated accordingly, especially for vulnerable groups, including older rural residents and those with lower educational attainment, to prevent cognitive function deterioration in middle-aged and older adults individuals with dual sensory impairment.

Trajectories of cognitive function development and predictive factors in disabled middle-aged and older adults

Objective

To explore the trajectories of cognitive function development and predictive factors in disabled middle-aged and older adults.

Methods

Utilizing data from 983 disabled middle-aged and older adults in the China Health and Retirement Longitudinal Study (CHARLS) from 2013 to 2020, latent growth mixture models were constructed to analyze the categories of cognitive function development trajectories and their predictive factors.

Results

The cognitive function trajectories of the disabled middle-aged and older adults were classified into three categories: rapid decline (32.6%), Slow decline (36.1%), and Stable (31.2%). Multinomial logistic regression analysis identified age, gender, residence, education, marital status, household income, sleep duration, depression, hearing ability, and social participation as predictors of these trajectories.

Conclusion

There is heterogeneity in the cognitive function development trajectories among disabled middle-aged and older adults. Healthcare professionals can implement targeted health management based on the characteristics of different groups to prevent the deterioration of cognitive function in this population.

A Web-Based Resilience-Enhancing Program to Improve Resilience, Physical Activity, and Well-being in Geriatric Population: Randomized Controlled Trial

BACKGROUND

Resilience is a protective factor in healthy aging, helping to maintain and recover physical and mental functions. The Resilience in Illness Model has proven effective in fostering resilience and well-being. Physical activity is crucial for older adults' independence and well-being, even as aging causes a progressive decline. Additionally, older adults face challenges such as spousal loss and physical disability, making preventive intervention strategies necessary.

OBJECTIVE

This study aims to develop and evaluate a web-based program to enhance resilience, physical activity, and well-being among community-dwelling older adults. Additionally, we aim to gather feedback on the program's strengths and limitations.

METHODS

A 4-week resilience-enhancing program was created, incorporating role-play and talk-in-interaction and focusing on 3 key skills: coping, control belief, and manageability. The program included scenarios such as becoming widowed and suffering a stroke, designed to engage older adults. A pilot test preceded the intervention. As a result of the COVID-19 pandemic, the program shifted from in-person to web-based sessions. A single-blind, parallel-group, randomized controlled trial was conducted. Participants aged over 65 years were recruited offline and randomly assigned to either an intervention or control group. A certified resilience practitioner delivered the program. Outcomes in resilience, physical activity, and well-being were self-assessed at baseline (T0), 4 weeks (T1), and 12 weeks (T2) after the program. A mixed methods approach was used to evaluate feedback.

RESULTS

A web-based participatory program enhancing 3 skills-coping, control belief, and manageability for resilience-was well developed. Among 96 participants, 63 were randomized into the intervention group (n=31) and the control group (n=32). The mean age in the intervention group was 69.27 (SD 3.08) years and 74.84 (SD 6.23) years in the control group. Significant between-group differences at baseline were found in age (t45.6=-4.53, P<.001) and physical activity at baseline (t61=2.92, P=.005). No statistically significant between-group differences over time were observed in resilience (SE 7.49, 95% CI -10.74 to 18.61, P=.60), physical activity (SE 15.18, 95% CI -24.74 to 34.74, P=.74), and well-being (SE 3.74, 95% CI -2.68 to 11.98, P=.21) after controlling for baseline differences. The dropout rate was lower in the intervention group (2/31, 6%) compared with the control group (5/32, 16%). Moreover, 77% (24/31) of participants in the intervention group completed the entire program. Program feedback from the participants indicated high satisfaction with the web-based format and mentorship support.

CONCLUSIONS

This study demonstrated that a web-based resilience-enhancing program is appropriate, acceptable, feasible, and engaging for community-dwelling older adults. The program garnered enthusiasm for its potential to optimize resilience, physical activity, and well-being, with mentorship playing a crucial role in its success. Future studies should aim to refine program content, engagement, and delivery methods to effectively promote healthy aging in this population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05808491; https://clinicaltrials.gov/ct2/show/NCT05808491.

Alcohol and stress exposure across the lifespan are key risk factors for Alzheimer's Disease and cognitive decline

Alzheimer's Disease and related dementias (ADRD) are an increasing threat to global health initiatives. Efforts to prevent the development of ADRD require understanding behaviors that increase and decrease risk of neurodegeneration and cognitive decline, in addition to uncovering the underlying biological mechanisms behind these effects. Stress exposure and alcohol consumption have both been associated with increased risk for ADRD in human populations. However, our ability to understand causal mechanisms of ADRD requires substantial preclinical research. In this review, we summarize existing human and animal research investigating the connections between lifetime stress and alcohol exposures and ADRD.

Social connections as determinants of cognitive health and as targets for social interventions in persons with or at risk of Alzheimer's disease and related disorders: a scoping review

BACKGROUND

Social connections have a significant impact on health across age groups, including older adults. Loneliness and social isolation are known risk factors for Alzheimer's disease and related dementias (ADRD). Yet, we did not find a review focused on meta-analyses and systematic reviews of studies that had examined associations of social connections with cognitive decline and trials of technology-based and other social interventions to enhance social connections in people with ADRD.

STUDY DESIGN

We conducted a scoping review of 11 meta-analyses and systematic reviews of social connections as possible determinants of cognitive decline in older adults with or at risk of developing ADRD. We also examined eight systematic reviews of technology-based and other social interventions in persons with ADRD.

STUDY RESULTS

The strongest evidence for an association of social connections with lower risk of cognitive decline was related to social engagement and social activities. There was also evidence linking social network size to cognitive function or cognitive decline, but it was not consistently significant. A number of, though not all, studies reported a significant association of marital status with risk of ADRD. Surprisingly, evidence showing that social support reduces the risk of ADRD was weak. To varying degrees, technology-based and other social interventions designed to reduce loneliness in people with ADRD improved social connections and activities as well as quality of life but had no significant impact on cognition. We discuss strengths and limitations of the studies included.

CONCLUSIONS

Social engagement and social activities seem to be the most consistent components of social connections for improving cognitive health among individuals with or at risk for ADRD. Socially focused technology-based and other social interventions aid in improving social activities and connections and deserve more research.

Widowhood and bereavement in late life

Bereavement is a common and often challenging experience in late life. Evidence shows that while many older adults manage to adjust well and demonstrate resilience in response to the death of a close person, bereavement puts a substantial minority at risk of adverse mental and physical health impacts including mortality. Current research further indicates that 1) this is the case across different countries and cultures across the globe; 2) that the COVID-19 pandemic posed unprecedented challenges for coping with late-life bereavement; 3) that loneliness and social isolation among bereaved older adults tend to be prevalent and harmful, particularly under pandemic but also in nonpandemic circumstances; and, recently, 4) that bereavement may be a risk factor for cognitive decline in this population.

Taiwanese family members' bereavement experience following an expected death: a systematic review and narrative synthesis

BACKGROUND

Bereavement experience is shaped by cultural and social contexts. No systematically constructed reviews were identified to explore the bereavement experience for people who are influenced by Chinese culture valuing filial piety and mutual dependence. This review aimed to systematically review the bereavement experience of Taiwanese family members living in Taiwan following an expected death.

METHODS

MEDLINE, PsycINFO, CINAHL, China Academic Journal Database, and Chinese Electronic Periodical Services were searched with no date restrictions from inception to 20 October 2022. The methodological rigour of studies was assessed using Hawker's appraisal tool. A narrative synthesis approach using Popay's work was employed to synthesise the findings of the studies. Studies investigating Taiwanese family members' bereavement experiences were included. We excluded papers studying bereavement through the death of a child.

RESULTS

Searches retrieved 12,735 articles (after de-duplication), 17 of which met the inclusion criteria and were included for synthesis: English [9] and Chinese [8], published between 2006 and 2021. The studies varied in quality with scores ranging from 22 to 33 out of 36. The studies differed in the relationship between participants and the deceased, the bereaved time frames, and the definitions of bereavement. Most studies focussed on family members of cancer patients receiving specialist palliative care. Three bereavement theories and four tools were used. Risk factors of bereavement outcomes included family members feeling less prepared for death and deaths where palliative sedative therapy was used. Protective factors were higher caregiving burden and longer caregiving periods. Four themes regarding Taiwanese bereavement experience were generated: multiple impacts of death; problem-based coping strategies; importance of maintaining connections; influential religious beliefs and rituals.

CONCLUSION

Continuing the relationship with the deceased is a key element of Taiwanese bereavement experience and it is influenced by religious and cultural beliefs. Suppressing or hiding emotions during bereavement to connect with the deceased and maintain harmonious relationships needs to be acknowledged as culturally acceptable and encouraged by some religions in Taiwan. The findings could be potentially relevant for other Chinese populations, predominantly Buddhist countries or other East Asian societies. The role of preparing for death in bereavement outcomes is little understood and requires further research.

Occurrence and Risk Factors for Cognitive Decline Shared by Couples: A Systematic Review and Meta-Analysis

Background

To date, the magnitude of association and the quality of evidence for cognitive decline (mild cognitive impairment, Alzheimer's disease, and dementia) in couples and risk factors for outcomes have not been reviewed and analyzed systematically.

Objective

The aim of this study was to investigate the concordance of cognitive impairment in unrelated spouses and to qualitatively describe potential risk factors.

Methods

Eight databases were searched from inception to October 20, 2023. Eligible studies were independently screened and assessed for quality. Statistical analysis was conducted using Stata 15.1 software. The study was preregistered with PROSPERO (CRD42023488024).

Results

Eleven studies involving couples were included, with moderate to high evidence quality. Compared to controls, spouses of individuals with cognitive impairment had lower cognitive scores (Cohen's d: 0.18-0.62) and higher risk of cognitive decline (OR = 1.42, 95% CI: 1.15-1.76). The consistency of cognitive impairment between spouses was attributed to three theories: 1) the impact of caregiving stress experienced by the spouse; 2) assortative mating, which suggests that individuals select partners with similar characteristics; and 3) the influence of shared living environments and lifestyles.

Conclusions

The cognitive status of one spouse can affect the cognitive function of the other spouse. It is important to consider shared lifestyle, environmental, and psychobehavioral factors, as they may contribute to the risk of cognitive decline by couples. Identifying these factors can inform the development of targeted recommendations for interventions and preventive measures.

Understanding the molecular basis of resilience to Alzheimer's disease

The cellular and molecular distinction between brain aging and neurodegenerative disease begins to blur in the oldest old. Approximately 15-25% of observations in humans do not fit predicted clinical manifestations, likely the result of suppressed damage despite usually adequate stressors and of resilience, the suppression of neurological dysfunction despite usually adequate degeneration. Factors during life may predict the clinico-pathologic state of resilience: cardiovascular health and mental health, more so than educational attainment, are predictive of a continuous measure of resilience to Alzheimer's disease (AD) and AD-related dementias (ADRDs). In resilience to AD alone (RAD), core features include synaptic and axonal processes, especially in the hippocampus. Future focus on larger and more diverse cohorts and additional regions offer emerging opportunities to understand this counterforce to neurodegeneration. The focus of this review is the molecular basis of resilience to AD.

Understanding the health effects of caregiving stress: New directions in molecular aging

Dementia caregiving has been linked to multiple health risks, including infectious illness, depression, anxiety, immune dysregulation, weakened vaccine responses, slow wound healing, hypertension, cardiovascular disease, metabolic syndrome, diabetes, frailty, cognitive decline, and reduced structural and functional integrity of the brain. The sustained overproduction of proinflammatory cytokines is a key pathway behind many of these risks. However, contrasting findings suggest that some forms of caregiving may have beneficial effects, such as maintaining caregivers' health and providing a sense of meaning and purpose which, in turn, may contribute to lower rates of functional decline and mortality. The current review synthesizes these disparate literatures, identifies methodological sources of discrepancy, and integrates caregiver research with work on aging biomarkers to propose a research agenda that traces the mechanistic pathways of caregivers' health trajectories with a focus on the unique stressors facing spousal caregivers as compared to other informal caregivers. Combined with a focus on psychosocial moderators and mechanisms, studies using state-of-the-art molecular aging biomarkers such as telomere length, p16INK4a, and epigenetic age could help to reconcile mixed literature on caregiving's sequelae by determining whether and under what conditions caregiving-related experiences contribute to faster aging, in part through inflammatory biology. The biomarkers predict morbidity and mortality, and each contributes non-redundant information about age-related molecular changes -together painting a more complete picture of biological aging. Indeed, assessing changes in these biopsychosocial mechanisms over time would help to clarify the dynamic relationships between caregiving experiences, psychological states, immune function, and aging.

Couples' Cognition, Intimacy, and Activity Engagement: An Actor-Partner Interdependence Model Analysis

OBJECTIVES

This study examines the actor and partner effects of cognition on activity engagement and the potential mediating role of intimate relationship in older couple dyadic context.

METHODS

Data for this study were obtained from heterosexual couples who participated in the 2020 wave of the Health and Retirement Study. Constructing a dyadic model of couples' cognitions, activity engagement, and intimacy using structural equation modeling to analyze the relationship between variables and mediating effects.

RESULTS

At the actor level, cognition was positively correlated with their activity participation. At the partner level, wives' cognition and husbands' activity engagement were positively correlated. Husband's cognitive score affect wife's subjective feelings about intimacy. The mediation effect of Wife's intimacy on the relationship between husband's cognition and wife's activity engagement was significant.

CONCLUSIONS

In older couples, cognition influences activity engagement at a binary level, and this association is influenced by the level of intimacy. Improving intimacy can help increase activity engagement in older couples, which in turn promotes health. Clinical Implications Maintaining cognition helps older people enjoy good marriage and participation in activities. For women, the closer the partnership, the higher the frequency of participating in various activities.

Spousal Cognitive Status and Risk for Declining Cognitive Function and Dementia: The Atherosclerosis Risk in Communities Study

Objectives: We investigated the relationship between the cognitive status of participants' spouses and participants' own cognitive outcomes, controlling for mid-life factors. Methods: Participants (n = 1845; baseline age 66-90 years) from the prospective Atherosclerosis Risk in Communities Study were followed from 2011 to 2019. We used linear regression and Cox proportional hazard models to estimate whether spouses of people with MCI/dementia had lower cognitive functioning and elevated risk of incident dementia. Results: Having a spouse with MCI/dementia was associated with a deficit in cognitive function (b = -0.09 standard deviations; 95% CI = -0.18, 0.00). Adjustment for mid-life risk factors attenuated this association (b = -0.02 standard deviations; 95% CI = -0.10, 0.06). We observed no significant relationship between spousal MCI/dementia status and incident dementia (hazard ratio = 0.97; 95% CI = 0.69, 1.38). Discussion: Spousal cognitive status is not associated with poor cognitive outcomes independent of mid-life factors.

Social Networks Effects on Spouse and Adult-Child Dementia Caregivers' Experiences: A Cross-Sectional Study

OBJECTIVES

A large body of literature addresses experiences of spouse and adult-children caregiver of individuals with dementia (IWDs) but has not examined the role and strength of social networks in associations between spouses and adult-children caregivers' experience. Based on the stress process model, we aimed to explore the strength levels of social networks and their association with spouses/adult-children caregivers for IWDs.

DESIGN

A cross-sectional study.

SETTING AND PARTICIPANTS

A questionnaire-based survey was conducted with a total of 146 family caregivers of IWDs (78 adult-child, and 68 spouses) in China.

METHODS

Data collection comprised 4 sections: (1) care-related stressors (dementia stage, neuropsychiatric symptoms); (2) caregiver context; (3) social network, using the Lubben Social Network Scale; and (4) caregiving experience, using the short-form Zarit Burden Interview and 9-item Positive Aspects of Caregiving Scale. Linear regression, mediation model analysis, and interactive analysis were performed to explore the mechanisms of associations between variables.

RESULTS

Spouses had weaker social network strength (β = -0.294, P = .001) and reported greater positive aspects of caregiving (β = 0.234, P = .003) than adult-children caregivers; no significant difference was found between them for caregiver burden. Mediation analysis suggests that associations between caregiver type and caregiver burden are indirect-only mediation effects of social networks (β = 0.140, 95% CI = 0.066-0.228). The social network strength suppressed the association between caregiver type and positive aspects of caregiving. The caregiver type/social network interaction statistically significantly (P = .025) affected the "positive aspects": a stronger social network was associated with more positive aspects of caregiving among the spouse subgroup (β = 0.341, P = .003).

CONCLUSIONS AND IMPLICATIONS

Social networks mediate responses to caregiving experiences among different care provider types and are vital intervention targets, especially for spousal caregivers. Our results can serve as references for identifying caregivers for clinical intervention.

The interactive effects of psychosocial stress and diet composition on health in primates

Social disadvantage and diet composition independently impact myriad dimensions of health. They are closely entwined, as social disadvantage often yields poor diet quality, and may interact to fuel differential health outcomes. This paper reviews effects of psychosocial stress and diet composition on health in nonhuman primates and their implications for aging and human health. We examined the effects of social subordination stress and Mediterranean versus Western diet on multiple systems. We report that psychosocial stress and Western diet have independent and additive adverse effects on hypothalamic-pituitary-adrenal and autonomic nervous system reactivity to psychological stressors, brain structure, and ovarian function. Compared to the Mediterranean diet, the Western diet resulted in accelerated aging, nonalcoholic fatty liver disease, insulin resistance, gut microbial changes associated with increased disease risk, neuroinflammation, neuroanatomical perturbations, anxiety, and social isolation. This comprehensive, multisystem investigation lays the foundation for future investigations of the mechanistic underpinnings of psychosocial stress and diet effects on health, and advances the promise of the Mediterranean diet as a therapeutic intervention on psychosocial stress.

Plasma levels of neurology-related proteins are associated with cognitive performance in an older population with overweight/obesity and metabolic syndrome

Cognitive impairment is present in a broad spectrum of medical conditions and in aging. Here, we aimed to identify plasma proteins related to cognitive function in a sample of older adults with overweight/obesity and metabolic syndrome. A total of 129 subjects (mean age 64.7 years; 36% females) were grouped according to low (l-GCF, N=65) or high (h-GCF, N=64) global cognitive function and matched according to education, sex, age, and body mass index. Cognitive performance was assessed using neuropsychological tests. Plasma levels of 92 neurology-related proteins were assessed using a proximity extension assay. An elastic net regression analysis was used to identify proteins more associated with cognitive performance. Additionally, the protein expression levels were compared between the two groups by means of a t-test with false discovery rate correction. Pearson correlations were used to assess associations between the protein levels and scores from the neurocognitive tests. Six proteins (alpha-2-MRAP, HAGH, Siglec-9, MDGA1, IL12, and EDA2R) were identified as potential contributors to cognitive performance, remaining significantly increased in l-GCF compared to h-GCF participants after correction for multiple testing. Negative correlations (r= -0.23 to -0.18, i.e., lower protein levels, higher cognitive function) were found between global cognitive function and Siglec-9, NMNAT1, HAGH, LXN, gal-8, alpha-2-MRAP, IL12, PDGF-R-alpha, NAAA, EDA2R, CLEC1B, and LAT. Mini-mental state examination z scores showed the strongest correlations with protein levels, specifically negative correlations with CLEC1b, LXN, LAT, PLXNB3, NMNAT1, gal-8, HAGH, NAAA, CTSS, EZR, KYNU, MANF (r=-0.38 to -0.26) and a positive correlation with ADAM23 (r= 0.26). In summary, we identified several plasma proteins that were significantly associated with cognitive performance in older adults with obesity and metabolic syndrome, although further research is needed to replicate the results in larger samples and to include a predictive perspective.

Sex-Specific Neurocognitive Impairment

This article explores sex-specific neurocognitive impairment. It first defines relevant terms such as gender and sex. Next, it describes the nature of the problem including under-representation of women and other gender and sexual minorities in neuroscience research, including cognitive studies. A biopsychosocial framework is employed to account for structural and social determinants of health in sex/gender-specific neurocognitive impairment. Issues in assessment including the use of gender/sex-specific normative data are also discussed. Lastly, the article covers the current state of research as it relates to sex/gender-specific neurocognitive impairment across a range of medical conditions including neurodegenerative diseases and coronavirus disease-2019.

The Widowhood Effect on Mortality in Older Patients with Hip Fracture

Objective

Widowed people have increased mortality than married people of the same age, a phenomenon known as the widowhood effect. This study aimed to investigate whether this effect exists in older patients with hip fracture.

Methods

Using our own hip fracture database, a total of 1101 hip fracture patients were consecutively included from January 2014 to December 2021. Marital status was stratified as married (n = 793) and widowed (n = 308). Patients survival status was obtained from medical records or telephone follow-ups, and the outcomes were all-cause mortality at 30 days, 1 year and at latest follow-up. Univariate and multivariate Cox proportional hazard models were used to assess the association between marital status and mortality, and subgroup analyses according to sex were also conducted.

Results

Compared with married patients, widowed patients were more likely to be older, female and intertrochanteric fracture, and were less likely to be urban area, smoking, drinking, and surgical treatment (P < 0.05). After a median follow-up of 37.1 months, the 30-day mortality was 4.3% (n = 47), 1-year mortality was 19.3% (n = 178), and total mortality was 34.2% (n = 376). Multivariate Cox analysis showed that widowed marital status remained an independent risk factor for 1-year mortality (HR = 1.437, 95% CI: 1.054–1.959, P = 0.022), and total mortality (HR = 1.296, 95% CI: 1.038–1.618, P = 0.022), whereas this association was not found in 30-day mortality (HR = 1.200, 95% CI: 0.607–2.376, P = 0.599). Moreover, subgroup analyses also found that the widowhood effect on mortality was present in both male and female.

Conclusion

Widowed marital status seems to be an independent risk factor for long-term mortality in older patients with hip fracture.