Associations of Loneliness and Social Isolation with Healthspan and Lifespan in the US Health and Retirement Study

Internet use and frailty in middle-aged and older adults: findings from developed and developing countries

BACKGROUND

With increasing trend of internet use in all age groups, whether internet use can prevent frailty in middle-aged and older adults remains unclear.

METHODS

Five cohorts, including Health and Retirement Study (HRS), China Health and Retirement Longitudinal Study (CHARLS), the Survey of Health, Ageing and Retirement in Europe (SHARE), English Longitudinal Study of Aging (ELSA), and Mexican Health and Aging Study (MHAS), were used in this study. Internet use, social isolation, and frailty status was assessed using similar questions. The Generalized estimating equations models, random effects meta-analysis, COX regression, and mediation analysis were utilized.

RESULTS

In the multicohort study, a total of 155,695 participants were included in main analysis. The proportion of internet use was varied across countries, ranging from 5.56% in China (CHARLS) to 83.46% in Denmark (SHARE). According to the generalized estimating equations models and meta-analysis, internet use was inversely associated with frailty, with the pooled ORs (95%CIs) of 0.72 (0.67,0.79). The COX regression also showed that participants with internet use had a lower risk of frailty incidence. Additionally, the association was partially mediated by social isolation and slightly pronounced in participants aged 65 and over, male, not working for payment, not married or partnered, not smoking, drinking, and not co-residence with children.

CONCLUSIONS

Our findings highlight the important role of internet use in preventing frailty and recommend more engagements in social communication and activities to avoid social isolation among middle-aged and older adults.

The reciprocal associations between social deficits, social engagement, and inflammation: Longitudinal evidence comparing venous blood samples and dried blood spots and mapping the modifying role of phenotypic and genotypic depression

BACKGROUND

Social psychoneuroimmunology suggests an interplay between social deficits (loneliness and isolation) and chronic inflammation, but the direction of these relationships remains unclear. We estimated the reciprocal associations of social deficits and social engagement with levels of C-reactive protein (CRP), compared the consistency of the findings depending on the biological sampling method used, and examined the modifying role of phenotypic and genotypic depression.

METHODS

We used longitudinal nationally representative data from the US (Health and Retirement Study, 3 waves, 2006-16) and England (English Longitudinal Study of Ageing, 4 waves, 2004-18). Loneliness, social isolation, and social engagement were self-reported. CRP was measured using dried blood spots (US) and venous blood samples (England). Cross-lagged panel models were fitted and tested interactions with phenotypic depression (above-threshold depressive symptom scores) and genotypic depression (polygenic score for major depressive disorder).

RESULTS

We included 15,066 participants (mean age = 66.1 years, SD = 9.8) in the US and 10,290 (66.9 years, SD = 10.5) in England. We found reciprocal associations between loneliness and CRP using dried blood spots and venous blood samples. Higher CRP predicted higher subsequent loneliness and higher loneliness predicted elevated CRP. Both phenotypic and genotypic depression modified this reciprocal association. There were also reciprocal associations for social engagement in venous blood samples: higher CRP predicted lower social engagement and greater social engagement predicted lower subsequent CRP. Associations between social isolation and CRP were inconsistent and unidirectional.

CONCLUSIONS

Loneliness may increase chronic inflammation, whereas social engagement may reduce inflammation. As these relationships were reciprocal, there may be a loop between inflammation, loneliness, and social engagement. This loop was stronger in those with depression or at high genetic risk for major depressive disorder. This relationship for loneliness was present in both blood sampling methods despite contrasting methods of CRP measurement, indicating that the finding is not attributable to measurement bias in biomarkers.

Effect of retirement on loneliness: a longitudinal comparative analysis across Australia, China and the USA

BACKGROUND

There is evidence that the transition to retirement can bring social challenges and may increase loneliness. Few studies have examined the impact of retirement on loneliness; most have been conducted in Western countries. It is important to examine the differences in loneliness postretirement across countries to identify patterns and risk factors that might influence the health and well-being of older adults. We aimed to examine the effect of retirement on loneliness among older adults in Australia, China and the USA.

METHODS

Longitudinal analysis of data from population-based samples of Australian, Chinese and American adults over 50. Lagged and fully lagged adjusted models were applied. Social engagement was examined as an effect modifier and a sensitivity analysis was conducted among urban participants.

RESULTS

Retirees had a higher predicted prevalence of loneliness than non-retirees in Australia (19.4% (95% CI 18.0% to 20.9%) vs 17.0% (95% CI 15.7% to 18.4%)) and in the USA (19.3% (95% CI 17.5% to 21.1%) vs 15.7% (95% CI 14.3% to 17.3%)). These differences were significant only in the USA. In China, loneliness was significantly lower in those who had retired (10.0% (95% CI 7.9% to 12.5%) vs 17.1% (95% CI 15.7% to 18.5%)). In Australia and the USA, voluntary retirees had the lowest loneliness and involuntary retirees had the highest. Social engagement did not modify the association between retirement and loneliness.

CONCLUSIONS

Our findings imply that the effect of retirement should be considered within a cultural context to inform suitable and effective strategies to alleviate loneliness.

Older Adults' Social Profiles and Links to Functional and Biological Aging in the United States and Mexico

OBJECTIVE

Social stress-loneliness, isolation, and low relationship quality-increase risks of aging-related diseases. However, the ways in which they intersect to undermine healthy aging remain poorly understood. We used latent class analysis to identify groups of older adults based on their social stress in both the United States and Mexico. Thereafter, we examined their cross-sectional associations with markers of functional and biological aging.

METHOD

Participants in the Health and Retirement Study (HRS; N = 8316) and Mexican Health and Aging Study (MHAS; N = 15,001) reported their loneliness, isolation (i.e., living alone), and relationship quality with spouse, children, and friends. Outcomes included C-reactive protein, functional limitations, self-rated health, comorbidities, gait speed, and grip strength. Models controlled for demographics, health behaviors, and body mass index.

RESULTS

In both countries, five classes emerged, a supported group and four with elevated social stress: a) strained, b) isolated, c) spousal ambivalence, and d) unhappily married. Compared with the others, strained participants in both samples had greater functional limitations, poorer self-rated health, and more comorbidities, as well as slower gait in HRS and weaker grip in MHAS. Generally, supported participants fared better than the other groups. In HRS, C-reactive protein levels differed between the strained group and others, but these associations were explained by health behaviors and body mass index.

CONCLUSIONS

Older adults in both countries with strained relationships fared worst in their aging-related outcomes, revealing new insights about the links between toxic social stress and unhealthy aging.

Association of Family Support With Lower Modifiable Risk Factors for Dementia Among Cognitively Impaired Older Adults

OBJECTIVES

Cognitive impairment poses considerable challenges among older adults, with the role of family support becoming increasingly crucial. This study examines the association of children's residential proximity and spousal presence with key modifiable risk factors for dementia in cognitively impaired older adults.

METHODS

We analyzed 14,600 individuals (35,165 observations) aged 50 and older with cognitive impairment from the Health and Retirement Study (1995-2018). Family support was categorized by spousal presence and children's residential proximity. Modifiable risk factors, including smoking, depressive symptoms, and social isolation, were assessed. Associations between family support and the modifiable risk factors were determined using mixed-effects logistic regressions.

RESULTS

A significant proportion of older adults with cognitive impairment lacked access to family support, with either no spouse (46.9%) or all children living over 10 miles away (25.3%). Those with less available family support, characterized by distant-residing children and the absence of a spouse, had a significantly higher percentage of smoking, depressive symptoms, and social isolation. Moreover, we revealed a consistent gradient in the percentage of the risk factors by the degree of family support. Relative to older adults with a spouse and co-resident children, those without a spouse and with all children residing further than 10 miles displayed the highest percentage of the risk factors. These findings were robust to various sensitivity analyses.

CONCLUSIONS

Family support from spouses and nearby children serves as a protective factor against modifiable dementia risk factors in cognitively impaired older adults. Policies that strengthen family and social support may benefit this population.

Longitudinal associations between loneliness, social isolation, and healthcare utilisation trajectories: a latent growth curve analysis

PURPOSE

To explore the longitudinal associations between eight-year trajectories of loneliness, social isolation and healthcare utilisation (i.e. inpatient, outpatient, and nursing home care) in US older adults.

METHODS

The study used data from the Health and Retirement Study in 2006-2018, which included a nationally representative sample of American adults aged 50 and above (N = 6,832). We conducted latent growth curve models to assess the associations between trajectories of loneliness and isolation and healthcare utilisation over 8 years.

RESULTS

Independent of sociodemographic and health-related confounders, social deficits were associated with a lower likelihood of baseline physician visits (loneliness β= -0.15, SE = 0.08; social isolation β= -0.19, SE = 0.08), but there was a positive association between loneliness and number of physician visits (β = 0.06, SE = 0.03), while social isolation was associated with extended hospital (β = 0.07, SE = 0.04) and nursing home stays (β = 0.05, SE = 0.02). Longer nursing home stays also predicted better trajectories of loneliness and isolation over time.

CONCLUSION

Loneliness and social isolation are cross-sectionally related to complex patterns of different types of healthcare. There was no clear evidence that social deficits led to specific trajectories of healthcare utilisation, but nursing home stays may over time help provide social contact, supporting trajectories of isolation and potentially loneliness. Non-clinical services such as social prescribing could have the potential to address unmet social needs and further promote patients' health-seeking profiles for improving healthcare equity.

HIV, Social Networks, and Loneliness among Older Adults in Uganda

Loneliness among older adults has been identified as a major public health problem. Yet little is known about loneliness, or the potential role of social networks in explaining loneliness, among older people with HIV (PWH) in sub-Saharan Africa, where 70% of PWH reside. To explore this issue, we analyzed data from 599 participants enrolled in the Quality of Life and Ageing with HIV in Rural Uganda study, including older adults with HIV in ambulatory care and a comparator group of people without HIV of similar age and gender. The 3-item UCLA Loneliness Scale was used to measure loneliness, and HIV status was the primary explanatory variable. The study found no statistically significant correlation between loneliness and HIV status. However, individuals with HIV had smaller households, less physical and financial support, and were less socially integrated compared to those without HIV. In multivariable logistic regressions, loneliness was more likely among individuals who lived alone (aOR:3.38, 95% CI:1.47-7.76) and less likely among those who were married (aOR:0.34, 95% CI:0.22-0.53) and had a higher level of social integration (aOR:0.86, 95% CI: 0.79-0.92). Despite having smaller social networks and less support, older adults with HIV had similar levels of loneliness as those without HIV, which may be attributed to resiliency and access to HIV-related health services among individuals with HIV. Nonetheless, further research is necessary to better understand the mechanisms involved.

Travel and Social Isolation of People With Spinal Cord Injury

Background

People with spinal cord injury (SCI) are at high risk for social isolation because they face barriers to social participation owing to limitations in physical functioning, secondary health conditions, and environmental barriers. Research has shown that social isolation, an objective lack of contact with others, can lead to loneliness, mental health issues, and low life satisfaction. Leisure travel, which involves interactions with others, may have the potential to reduce social isolation.

Objectives

To explore the association of travel participation with social isolation among people with SCI.

Methods

A total of 11,091 cases from 2016-2021 in the SCI Model Systems database were included in the study. Participants were categorized into low and high social isolation groups. A hierarchical logistic regression was performed with social isolation as the dependent variable and travel groups as the independent variable, while controlling for age, family income, and health conditions.

Results

Travel participation is negatively associated with social isolation. People with SCI who traveled for one to two nights (odd ratio [OR] 0.52, 95% CI 0.40-0.67), three to four nights (OR 0.56, 95% CI 0.43-0.72), or more than five nights (OR 0.41, 95% CI 0.35-0.49) in the past 12 months are less likely to be socially isolated compared to those who have not traveled in the past 12 months.

Conclusion

Travel participation may help reduce the social isolation of individuals with SCI. Therapists and rehabilitation professionals should design effective travel training programs that encourage patients with SCI to travel more often.

The Long-Term Impacts of Dementia on Preventive Care Utilization and Health Behaviors

Dementia has large impact on individuals' decision making, independent living, and wellbeing. Identifying early signals of dementia risk may offer people more time to prepare for the future, helping to delay the onset or slow the progression of dementia. Using the 1995-2018 waves of Health and Retirement Study, we offer novel evidence on the impacts of dementia on a rich set of preventive care utilization and health behaviors. Leveraging both within- and between-individual variations in an event study design, we characterize long-term dynamic changes in preventive care and health behaviors relative to the incidence of dementia and find early behavioral indicators of the disorder. We show that relative to the group of people who never develop dementia during the study periods, people with dementia have consistent and escalating declines in the use of cholesterol test, dental visit, prostate test and mammogram around the incidence of dementia. Significant declines are also found in physical activities and social engagement. Importantly, we demonstrate that the behavioral changes can occur up to 6 years before the incidence of dementia; and these patterns are absent in other chronic or acute conditions. The results are robust to sample selection, model specification, and the further control of aging and cohort effects. Overall, our findings highlight the salient impact of dementia risk on preventive care utilization and health behaviors, which may increase individuals' vulnerability to health shocks. Detecting early signals of dementia and facilitating targeted interventions are thus called for to prevent individuals from adverse behavioral and health consequences.

Children's Residential Proximity, Spousal Presence and Modifiable Risk Factors for Dementia among Older Adults with Cognitive Impairment

Background

Cognitive impairment in older adults poses considerable challenges, and the role of family support becomes increasingly crucial. This study aims to examine the impact of children's residential proximity and spousal presence on the key modifiable risk factors for dementia among older adults with cognitive impairment.

Methods

Utilizing the Health and Retirement Study (HRS) data from 1995 to 2018, we analyzed 14,731 participants (35,840 person-waves) aged 50 and older with cognitive impairment. Family support was characterized based on the presence of a spouse and residential proximity to children. Smoking, depressive symptoms and social isolation were included as the key modifiable risk factors for dementia identified in later life. Using mixed-effects logistic regressions, associations between access to family support and the modifiable risk factors were determined, adjusting for various socio-demographic and health-related factors.

Results

Significant associations were found between access to family support and modifiable risk factors for dementia. Cognitively impaired older adults with less available family support, characterized by distant-residing children and the absence of a spouse, had significantly higher risks of smoking, depressive symptoms, and social isolation. Moreover, we revealed a consistent gradient in the prevalence of the risk factors based on the degree of family support. Relative to older adults with a spouse and co-resident children, those without a spouse and with all children residing further than 10 miles displayed the highest risks of smoking, depressive symptoms, and social isolation.

Conclusion

Access to family support, particularly from spouses and proximate children, plays a protective role against key modifiable risk factors for dementia in older adults with cognitive impairment. The findings highlight the need for bolstering family and social support systems to enhance the well-being of this vulnerable population.

Social Isolation, Sleep Disturbance, and Cognitive Functioning (HRS): A Longitudinal Mediation Study

BACKGROUND

Social isolation is prevalent and associated with dementia, yet the directionality and mechanisms are less understood. This study examined the association between social isolation and cognitive functioning and explored the mediating role of sleep disturbance on the social isolation-cognition relationship.

METHODS

Data from 5 753 dementia-free Americans aged ≥50 of 2006 (T1), 2010 (T2), and 2014 (T3) waves of the Health and Retirement Study. Social isolation was measured by the Steptoe Social Isolation Index. Cognitive functioning was measured by the Telephone Interview of Cognitive Status. Sleep disturbance was measured with the modified Jenkins Sleep Scale. We used cross-lagged panel models to determine the associations between social isolation, sleep disturbance, and cognitive functioning.

RESULTS

Social isolation is significantly associated with subsequent cognitive functioning (T1 to T2: β = -0.055, standard error [SE] = 0.014, p < .001; T2 to T3: β = -0.044, SE = 0.016, p < .001). Lower cognitive functioning is significantly associated with greater subsequent social isolation (T1 to T2: β = -0.101, SE = 0.020, p < .001; T2 to T3: β = -0.058, SE = .011, p < .001). Sleep disturbance at T2 partially mediated the effect of social isolation (T1) on cognitive functioning (T3), accounting for 6.2% of the total effect (β = -0.003, SE = 0.001, p < .01).

CONCLUSIONS

Social isolation may deteriorate cognitive functioning and vice versa. The association between social isolation and cognition is partially explained by sleep disturbance.

The Relationship Between Internet Use for Social Purposes, Loneliness, and Depressive Symptoms Among the Oldest Old

The internet enables communication with social partners and has been found to be related to higher psychological well-being among older adults. Using data from the representative German North Rhine-Westphalia 80+ (NRW80+) study (n = 1,698, Mage = 84.86), we conducted linear regression and mediation analyses to compare levels of loneliness and depressive symptoms of onliners using the internet for social or other purposes with offliners. Oldest old onliners used the internet mostly for social purposes, and this type of internet use was related to a significantly lower level of loneliness and fewer depressive symptoms compared to offliners. The mediation analysis revealed that internet use for social purposes was related to lower levels of loneliness, which in turn was associated with a lower number of depressive symptoms. The findings suggest that internet use for social purposes may help the oldest old to reduce feelings of loneliness and depressive symptoms.

Association of Social Isolation With Hospitalization and Nursing Home Entry Among Community-Dwelling Older Adults

Importance

Social isolation is associated with adverse health outcomes, yet its implications for hospitalization and nursing home entry are not well understood.

Objective

To evaluate whether higher levels of social isolation are associated with overnight hospitalization, skilled nursing facility stays, and nursing home placement among a nationally representative sample of community-dwelling older adults after adjusting for key health and social characteristics, including loneliness and depressive symptoms.

Design, Setting, and Participants

This observational cohort study included 7 waves of longitudinal panel data from the Health and Retirement Study, with community-dwelling adults aged 65 years or older interviewed between March 1, 2006, and June 30, 2018 (11 517 respondents; 21 294 person-years). Data were analyzed from May 25, 2022, to May 4, 2023.

Main Outcomes and Measures

Social isolation was measured with a multidomain 6-item scale (range, 0-6, in which a higher score indicates greater isolation). Multivariate logistic regressions were performed on survey-weighted data to produce national estimates for the odds of self-reported hospitalization, skilled nursing facility stays, and nursing home placement over time.

Results

A total of 57% of this study's 11 517 participants were female, 43% were male, 8.4% were Black, 6.7% were Hispanic or Latino, 88.1% were White, 3.5% were other ("other" includes American Indian or Alaska Native, Asian or Pacific Islander, and other race, which has no further breakdown available because this variable was obtained directly from the Health and Retirement Study), and 58.2% were aged 65 to 74 years. Approximately 15% of community-dwelling older adults in the US experienced social isolation. Higher social isolation scores were significantly associated with increased odds of nursing home placement (odds ratio, 2.01; 95% CI, 1.21-3.32) and skilled nursing facility stays (odds ratio, 1.16; 95% CI, 1.06-1.28) during 2 years. With each point increase in an individual's social isolation score, the estimated probability of nursing home placement or a skilled nursing facility stay increased by 0.5 and 0.4 percentage points, respectively, during 2 years. Higher levels of social isolation were not associated with 2-year hospitalization rates.

Conclusions and Relevance

This cohort study found that social isolation was a significant risk factor for nursing home use among older adults. Efforts to deter or delay nursing home entry should seek to enhance social contact at home or in community settings. The design and assessment of interventions that optimize the social connections of older adults have the potential to improve their health trajectories and outcomes.

Investigating Biological Pathways Underpinning the Longitudinal Association Between Loneliness and Cognitive Impairment

BACKGROUND

Loneliness precedes the onset of cognitive impairment (CI) in older adults. Although the mechanisms through which loneliness "gets under the skin" to influence the risk of developing CI have been conceptually proposed, they are rarely empirically examined. The Evolutionary Theory of Loneliness posits that loneliness as a stressor could cause dysregulations in multiple physiological systems. The current study investigated whether inflammatory, cardiovascular, and kidney biomarkers mediate the longitudinal association between loneliness and CI.

METHODS

Cross-lagged panel models were used to examine the hypothesized relationships, using 2006, 2010, and 2014 waves of data from the Health and Retirement Study (N = 7,037). Loneliness was measured with the 3-item UCLA loneliness scale. CI was assessed with the modified telephone interview for cognitive status. Biomarkers included HbA1C, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, C-reactive protein, and Cystatin C. Using a stepwise model-building approach, first, the model included only loneliness, CI, and biomarker variables; then, sociodemographic covariates were added; lastly, health status were controlled for.

RESULTS

In unadjusted and partially adjusted models, loneliness was associated with higher odds of worse cognitive status in an 8-year follow-up. Only HbA1C mediated the longitudinal association between loneliness and CI. However, after further controlling for health status, all associations became nonsignificant.

CONCLUSIONS

Examining a large number of participants and linking a limited number of biological markers with cognition and loneliness longitudinally, our empirical data did not support theoretical propositions, highlighting the critical importance of controlling for confounders in future studies examining longitudinal mediational relationships underlying loneliness and CI.

The prevalence of chronic and episodic loneliness and social isolation from a longitudinal survey

Loneliness and social isolation, experienced more long-term, has been shown to increase mortality and lead to poorer health outcomes in specific cohorts. However, it is unclear what the prevalence of chronic loneliness and social isolation is, and which demographic groups are most at risk of reporting more chronic forms. A psychometrically validated classification system was used to identify people who met criteria for episodic and chronic loneliness and social isolation using the Household Income and Labour Dynamics in Australia (HILDA) survey waves 14-18. The prevalence of loneliness (overall 34%; 21% episodic, 13% chronic) far exceeded that of social isolation (overall 17%; 13% episodic, 4% chronic). There was consistency in the demographic characteristics (from age, sex, household type, income) of those who experienced loneliness and social isolation. However, people with a long-term health condition had an elevated risk of episodic loneliness (AOR 1.24, 95% CI 1.11-1.39) and a markedly higher risk of chronic loneliness (AOR 2.01, 95% CI 1.76-2.29), compared with those without a long-term health condition. Loneliness, both episodic and chronic subtypes, is more prevalent than social isolation. However, both chronic loneliness and social isolation remains neglected and poorly targeted within current practice and policy.

Association Between Types of Loneliness and Risks of Functional Disability in Older Men and Women: A Prospective Analysis

OBJECTIVE

To examine the association between types of loneliness (transient, incident, and chronic) and the risk of functional disability.

METHODS

Data were from the Health and Retirement Study 2006/2008-2016/2018. A total of 7,148 adults aged ≥50 was included. Functional status was measured by activities of daily living (ADL) and instrumental activities of daily living (IADL). Loneliness was assessed using the 3-item UCLA Loneliness Scale. We defined loneliness as no/transient/incident/chronic loneliness based on the pattern and duration of loneliness across 2006/2008 and 2010/2012. We applied multivariate Cox proportional hazard models with the new-onset ADL/IADL disability as outcome.

RESULTS

Overall, 69.3% respondents showed no loneliness; while 10.3%, 8.9%, and 11.5% showed transient, incident, and chronic loneliness, respectively. A total of 1,298 (18.16%) and 1,260 (17.63%) functionally normal respondents developed ADL and IADL disability during 36,294 person-years of follow-up, respectively. After adjusting for socio-demographic, behavioral, and health factors, chronic loneliness was associated with higher risks of ADL (hazard ratio [HR] = 1.37, 95% confidence interval [CI] = 1.16-1.63, p <0.001, χ2 = 3.60, degree of freedom [df] = 1) and IADL disability (HR = 1.25, 95% CI = 1.09-1.44, p = 0.002, χ2 = 3.17, df = 1) compared to no loneliness. By contrast, no significant associations between transient loneliness and ADL (HR = 1.17, 95% CI = 0.88-1.57, p = 0.273, χ2 = 1.10, df = 1) or IADL disability (HR = 1.16, 95% CI = 0.97-1.39, p = 0.112, χ2 = 1.59, df = 1) were found. Chronic loneliness was not associated with the risk of IADL disability in men (HR = 1.13, 95% CI = 0.91-1.40, p = 0.263, χ2 = 1.12, df = 1).

CONCLUSION

Chronic loneliness, rather than transient loneliness, is an independent risk factor for functional disability in middle-aged and older adults, especially for women.

A systematic review and meta-analysis of 90 cohort studies of social isolation, loneliness and mortality

The associations between social isolation, loneliness and the risk of mortality from all causes, cardiovascular disease (CVD) and cancer are controversial. We systematically reviewed prospective studies on the association between social isolation, loneliness and mortality outcomes in adults aged 18 years or older, as well as studies on these relationships in individuals with CVD or cancer, and conducted a meta-analysis. The study protocol was registered with PROSPERO (reg. no. CRD42022299959). A total of 90 prospective cohort studies including 2,205,199 individuals were included. Here we show that, in the general population, both social isolation and loneliness were significantly associated with an increased risk of all-cause mortality (pooled effect size for social isolation, 1.32; 95% confidence interval (CI), 1.26 to 1.39; P < 0.001; pooled effect size for loneliness, 1.14; 95% CI, 1.08 to 1.20; P < 0.001) and cancer mortality (pooled effect size for social isolation, 1.24; 95% CI, 1.19 to 1.28; P < 0.001; pooled effect size for loneliness, 1.09; 95% CI, 1.01 to 1.17; P = 0.030). Social isolation also increased the risk of CVD mortality (1.34; 95% CI, 1.25 to 1.44; P < 0.001). There was an increased risk of all-cause mortality in socially isolated individuals with CVD (1.28; 95% CI, 1.10 to 1.48; P = 0.001) or breast cancer (1.51; 95% CI, 1.34 to 1.70; P < 0.001), and individuals with breast cancer had a higher cancer-specific mortality owing to social isolation (1.33; 95% CI, 1.02 to 1.75; P = 0.038). Greater focus on social isolation and loneliness may help improve people's well-being and mortality risk.

[Loneliness and its association with sociodemographic and health indicators in Brazilian adults and older adults: ELSI-Brazil]

This study aimed to investigate the prevalence of loneliness and its associations with sociodemographic and health indicators in a nationally representative sample of Brazilian adults and older adults. Data from the baseline (2015-2016) of the Brazilian Longitudinal Study of Aging (ELSI-Brazil) were analyzed, and participants with complete information on the variables of interest (n = 7,957) were included. Loneliness was the outcome variable, which was based on the question "How often do you feel alone or lonely: always, sometimes, or never?" Independent variables included sociodemographic indicators and health behaviors and conditions. The analyses included the Pearson's chi-square test for calculating relative frequencies, and Poisson regression for estimating prevalence ratios (PR) and their respective 95% confidence intervals (95%CI). The prevalence of always feeling lonely was 16.8%; sometimes, 31.7%; and never, 51.5%. Significant associations were observed between always feeling lonely and depression (PR = 4.49; 95%CI: 3.93-5.11), living alone (PR = 2.44; 95%CI: 2.12-2.82), low education level (PR = 1.93; 95%CI: 1.61-2.32), being a woman (PR = 1.53; 95%CI: 1.36-1.72), self-rated poor/very poor health (PR = 1.48; 95%CI: 1.27-1.73), and poor/very poor sleep quality (PR = 1.21; 95%CI: 1.05-1.41). Given its potential to harm quality of life, it is necessary to longitudinally understand the trajectories of loneliness and associated variables, and to use this knowledge to design public policies and health interventions that could benefit the biopsychosocial well-being of Brazilian adults and older adults.

Loneliness and Functional Decline in Aging: A Systematic Review

Loneliness is prevalent in adults aged ≥65 years in the United States and is associated with functional decline. The purpose of the current review was to synthesize evidence on the relationship between loneliness and functional decline using Roy's Adaptation Model as a theoretical framework. A comprehensive review of PubMed, Medline, and Embase databases was performed. Inclusion criteria were samples including adults primarily aged >60 years, peer-reviewed, published in the English language, and included a measure for loneliness and function. A total of 47 studies were analyzed. Most studies examined correlates, risk factors, and predictors of loneliness, rather than the relationship between loneliness and function. Evidence suggests there is bidirectionality in the relationship between loneliness and functional decline. Loneliness is associated with functional decline in aging via multiple possible pathways. Further studies are needed to determine causality and biological mechanisms underlying the relationship. [Research in Gerontological Nursing, 16(4), 202-212.].

Recruiting Socially Disconnected Latinos Caring for a Person with Alzheimer's Disease and Related Dementias During the COVID-19 Pandemic: Lessons Learned

OBJECTIVES

The purpose of this article is to present conceptual and methodological challenges to recruitment strategies in enrolling socially disconnected middle-aged and older Latino caregivers of a loved one with Alzheimer's disease and related dementias (ADRD).

METHODS

Middle-aged and older Latino ADRD caregivers were recruited into two early stage, intervention development studies during the COVID-19 pandemic via online or in-person methods. Recruitment criteria included Latino ADRD caregivers over the age of 40 reporting elevated loneliness on the UCLA 3-item Loneliness Scale (LS) during screening.

RESULTS

Middle-aged, Latino caregivers were recruited predominantly from online methods whereas older caregivers were mostly recruited from in-person methods. We report challenges identifying socially disconnected Latino caregivers using the UCLA 3-item LS.

CONCLUSIONS

Our findings support previously reported disparities in recruitment by age and language and suggest further methodological considerations to assess social disconnection among Latino caregivers. We discuss recommendations to overcome these challenges in future research.

CLINICAL IMPLICATIONS

Socially disconnected Latino ADRD caregivers have an elevated risk for poor mental health outcomes. Successful recruitment of this population in clinical research will ensure the development of targeted and culturally sensitive interventions to improve the mental health and overall well-being of this marginalized group.

Persistence of social isolation and mortality: 10-year follow-up of the Guangzhou Biobank Cohort study

Although social isolation has been associated with higher mortality risk, the associations of persistence of social isolation with mortality are unclear. We investigated the prospective associations of intermittent and persistent social isolation with all-cause and cause-specific mortality, considering the social contact types (face-to-face and non-face-to-face). 30,518 participants were recruited in 2003-2008 initially and 18,104 participants with re-assessed social isolation information in 2008-2012 were followed up to Dec 2019 in Guangzhou Biobank Cohort Study (GBCS). During an average of 9.7 years of follow-up, 2,119 deaths occurred. The isolation at baseline survey, isolation at second survey and persistent isolation were positively associated with all-cause mortality in the minimal adjusted model (adjusted hazard ratio (AHR) =1.24, 95% CI 1.12-1.38, 1.11, 1.00-1.23 and 1.23, 1.05-1.43, respectively). Totally 47.2% of the risk was explained by health status, SEP, and biological, behavioural and psychological factors. Persistent isolation from face-to-face with co-inhabitants, versus no isolation, was associated with higher risks of all-cause (HR=1.40, 1.09-1.81) and CVD (subdistribution hazard ratio (SHR)=1.92, 1.31-2.81) mortality in fully adjusted model. Our study showed that intermittent and persistent isolation were generally associated with higher risks of mortality, and the risks were even higher in those with persistent face-to-face isolation with co-inhabitants.

Positive social factors prospectively predict younger epigenetic age: Findings from the Health and Retirement Study

OBJECTIVES

Positive social factors may slow biological aging, but this has yet to be rigorously tested. This study investigated whether baseline levels or changes over time in social support and contact frequency prospectively predicted epigenetic age.

METHOD

Health and Retirement Study participants (N = 1912, 46.3 % male, aged 42-87 at baseline) reported longitudinal social support and contact frequency data up to 3 times between 2006 and 2016 and provided blood in 2016. Baseline levels (intercepts) and changes over time (slopes) in social support from and contact frequency with spouses, children, friends, and other family were outputted from multilevel models and used to predict epigenetic age, estimated from Horvath, Hannum, GrimAge, PhenoAge, and Dunedin Pace of Aging.

RESULTS

In models adjusted for demographic and health characteristics, higher baseline levels of support from and contact frequency with friends were prospectively associated with a slower Pace of Aging (support: p = .002; contact: p = 0.009) and a lower GrimAge (contact: p = .001). In addition, higher contact frequency with children at baseline was prospectively associated with a lower GrimAge (p < .001), and higher contact frequency with family at baseline and an increase in family contact over time was associated with a lower Hannum age (baseline: p = .005; slope: p = .015).

CONCLUSIONS

Perceived support from and contact with close others, particularly friends, may have implications for healthy biological aging. Notably, the effect sizes for friends were comparable to the effect of body mass index on epigenetic age. Positive social factors were generally associated with second- and third-generation clocks, which may be more sensitive to psychosocial factors than first-generation clocks.

The multiple roles of life stress in metabolic disorders

The activation of stress-related neuroendocrine systems helps to maintain homeostasis, but excessive stress can damage body functions. We review current evidence from basic sciences and epidemiology linking stress to the development and progression of metabolic disorders throughout life. Findings from rodents demonstrate that stress can affect features of metabolic dysfunction, such as insulin resistance, glucose and lipid homeostasis, as well as ageing processes such as cellular senescence and telomere length shortening. In human studies, stressors in the home, workplace and neighbourhood are associated with accelerated ageing and metabolic and immune alterations, both directly and indirectly via behavioural risks. The likelihood of developing clinical conditions, such as diabetes mellitus and hepatic steatosis is increased in individuals with adverse childhood experiences or long-term (years) or severe stress at work or in private life. The increased risk of metabolic disorders is often associated with other stress-related conditions, such as mental health disorders, cardiovascular disease and increased susceptibility to infections. Equally, stress can worsen prognosis in metabolic diseases. As favourable modifications in stressors are associated with reductions in incidence of metabolic disorders, further investigation of the therapeutic value of targeting stress in personalized medicine is warranted.

Social isolation as a risk factor for all-cause mortality: Systematic review and meta-analysis of cohort studies

BACKGROUND

Although several epidemiological studies have linked social isolation to increased risk of mortality, the magnitude of any effect is unclear, in part because of the use of different measures of social isolation.

OBJECTIVE

To examine the association between social isolation and all-cause mortality and investigate whether it differs in various subgroups or populations.

DATA SOURCES

We searched for relevant studies in electronic databases: MEDLINE (1946 to December 31, 2021), EMBASE (1974 to December 31, 2021), and PsycINFO (1806 to December 31, 2021).

SELECTION CRITERIA

We included both prospective and retrospective cohort studies that examined the association between social isolation and all-cause mortality among adults.

DATA COLLECTION AND ANALYSIS

Two reviewers screened and extracted data independently. We contacted study authors to obtain missing information whenever possible. Data were pooled using a random effect model to calculate estimates of the effects of social isolation on all-cause mortality.

RESULTS

Data from studies involving 1.30 million individuals were included. The pooled hazard ratio of social isolation for all-cause mortality was 1.33 (95% confidence interval; 1.26-1.41, heterogeneity: Chi² = 112.51, P < 0.00001, I² = 76%).

CONCLUSION

Social isolation is associated with increased risk for all-cause mortality.

REGISTRATION

PROSPERO (CRD42020152351).

Racial and Ethnic Differences in the Relationship Between Neighborhood Environment and Physical Activity Among Middle-Aged and Older Adults

Objectives:To examine the associations between neighborhood environment-perceived neighborhood social cohesion and perceived neighborhood physical environment-and physical activity (PA) and whether these associations differ by race/ethnicity. Methods: We analyzed data from the Health and Retirement Study, a longitudinal study of US adults aged 50+ from 2006 to 2014 (N = 17,974), using multivariate mixed-effects linear models. PA was repeatedly measured using metabolic equivalent of task estimated values accounting for the vigor and frequency of self-reported PA. Results: In multivariate models, higher levels of PA were positively associated with higher rated neighborhood social cohesion and neighborhood physical environment scores. The effects of social cohesion were stronger among non-Hispanic Whites than among non-Hispanic Black and Hispanic/Latinx participants, while race/ethnicity did not moderate the association between PA and physical environment. Discussion: Intervention strategies that address social and physical barriers of neighborhoods could promote PA in older adults. Key implications for future research are discussed.

Joint associations of social health and movement behaviours with mortality and cardiovascular disease: an analysis of 497,544 UK biobank participants

Background

Poor physical activity and excessive sedentary behaviour are well-established risk factors for morbidity and mortality. In the presence of emerging social problems, including loneliness and social isolation, these risks may be even greater. We aimed to investigate the joint effects of social health and movement behaviours on mortality and cardiovascular disease (CVD).

Methods

497,544 UK Biobank participants were followed for an average of 11 years. Loneliness and social isolation were measured via self-report. Physical activity was categorised around current World Health Organisation (WHO) guidelines as low (< 600 metabolic equivalent of task [MET]-mins/week), moderate (600 < 1200) and high (≥ 1200). Sedentary behaviour was classified as low (≤ 3.5 h/day), moderate (3.5 ≤ 5) and high (> 5.5). We derived 24 social health–movement behaviour combinations, accordingly. Mortality and hospitalisations were ascertained to May 2020 for all-cause and CVD mortality, and non-fatal cardiovascular events.

Results

Social isolation amplified the risk of both all-cause and CVD death across all physical activity and sedentary levels (hazard ratio, 95% confidence interval [HR, 95% CIs] for all-cause mortality; 1.58 [1.49 to 1.68] for low active-isolated vs. 1.26 [1.22 to 1.30] for low active-not isolated). Loneliness was only found to amplify the risk of death from cardiovascular disease among the high active and low sedentary participants. Loneliness and social isolation did not add to the risk of non-fatal cardiovascular events across most activity levels.

Conclusion

The detrimental associations of poor physical activity and sedentary behaviour with mortality were consistently amplified by social isolation. Our study supports the need to target the socially isolated as a priority group in preventive public health strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01372-3.

Food insecurity and loneliness amongst older urban subsidised housing residents: The importance of social connectedness

Food insecurity and loneliness are shockingly large and growing problems in the older population in the U.S. and globally. Thus, the study's primary aim was to investigate the prevalence as well as the association between these two social determinants of health in the marginalised and often underserved population of older residents of urban subsidised housing (also referred to as social housing or affordable housing). Of particular interest was whether a greater sense of loneliness increases the risk of older residents being food insecure. The study uses survey data gathered through in-person interviews conducted onsite in English or Spanish with 216 of the 300 older adults (72% response rate) living in a subsidised housing community in a central neighbourhood of a U.S. northeastern city. Amongst the 216 participants, 50% identified as Black and 45% identified as Latino. In addition to food insecurity and loneliness, the survey assessed participants' health, food access challenges, and sociodemographic characteristics. Results revealed a 34% food insecurity prevalence rate amongst the participants which is higher than the estimate of slightly less than 10% of the U.S. older population being food insecure. The participants' 34% loneliness rate was also higher than the 19%-29% prevalence range in U.S. older population studies. Bivariate analyses highlighted the interrelatedness or intertwining of food insecurity, loneliness, poor health and food access challenges whilst a series of logistic regressions further explored the significant association of loneliness with food insecurity. Loneliness increased the odds ratio of food insecurity in the binary (unadjusted) regression (p < 0.001, OR = 3.1) and the multivariate (adjusted) regression that included all covariates (p < 0.05, OR = 2.4). Overall, the findings underscore the need for greater awareness of loneliness as a public health threat as well as future research exploring how loneliness may intensify the health consequences of food insecurity in later life.

COVID-19 pandemic partnership between medical students and isolated elders improves student understanding of older adults' lived experience

BACKGROUND

Evidence supports loneliness and social isolation as a strong risk factor for poor mental and physical health outcomes for older adults. The COVID-19 pandemic necessitated older adults isolate themselves for a prolonged duration. The Faculty of Medicine at the University of Toronto established the Student-Senior Isolation Prevention Partnership (SSIPP), a volunteer program involving telephone calls between medical students and older adults.

METHODS

A mixed methods pre-post study design included collecting quantitative data from older adults using the UCLA Loneliness Scale and the Warwick-Edinburgh Mental Well-being Scale. The study included 29 medical students and 47 older adults. The medical students filled out a questionnaire on self-perceived knowledge of social isolation, perception of seniors, attitudes towards seniors, and likelihood to engage in specialties focusing on older adults. Interviews were conducted with both the older adults and the medical students to understand each groups' experiences and perspectives with taking part in the SSIPP program.

RESULTS

Participation in the program resulted in significant changes for medical students in areas such as increasing their likelihood to engage in care for older adults (p < .001), improving their knowledge of social isolation for seniors (p < .001), and the value of addressing social isolation in older adults (p < .001). The interviews conducted with the medical students support these findings and provide insight into contributing factors. Loneliness and mental well-being scales did not show significant changes for older adults however, our interviews revealed they considered the program to be valuable.

CONCLUSIONS

Our results showed that after the communication outreach program, medical students' perceptions were positively influenced towards older adults and they were more likely to pursue a career concentrated on older adults. The qualitative analysis revealed older adults valued the program. Timing and consistency of calls were factors identified by this group as having practical importance.

Strategies for Maintaining Brain Health: The Role of Stroke Risk Factors Unique to Elderly Women

Stroke risk and prevalence increase with advanced age and women tend to be older than men at the time of their first stroke. Advanced age in women confers unique stroke risks that are beyond reproductive factors. Previous reviews and guidelines have largely focused on risk factors specific to women, with a predominant focus on reproductive factors and, therefore, younger to middle-aged women. This review aims to specifically describe stroke risk factors in elderly women, the population of women where the majority of strokes occur, with a focus on atrial fibrillation, hormone therapy, psychosocial risk factors, and cognitive impairment. Our review suggests that prevention and management of stroke risks that are unique or more prevalent in elderly women needs a coordinated system of care from general physicians, general neurologists, vascular and cognitive neurologists, psychologists, cardiologists, patients, and their caretakers. Early identification and management of the elderly woman-specific and traditional stroke risk factors is key for decreasing stroke burden in elderly women. Increased education among elderly women regarding stroke risk factors and their identification should be considered, and an update to the guidelines for prevention of stroke in women is strongly encouraged.

Associations between loneliness and frailty among older adults: Evidence from the China Health and Retirement Longitudinal Study

Background

Previous studies have demonstrated the associations between loneliness and frailty in late life. However, there is a lack of consensus on the direction of the relationship. The present study aimed to examine the interdependencies between loneliness and frailty over time.

Methods

Data on participants aged 60 years old and above were collected from the 2011, 2013, and 2015 samples of the China Health and Retirement Longitudinal Study (CHARLS). Loneliness was measured by a single question from the Centre for Epidemiological Studies Depression scale, and frailty was assessed by the Physical Frailty Phenotype (PFP) scale. Cross-lagged panel models were utilized to examine the potential bidirectional relationship between loneliness and frailty.

Results

Reciprocal associations were found between loneliness and frailty. Furthermore, we found that baseline frailty and early change in frailty had a significant predictive effect on late change in loneliness. Higher baseline loneliness in older adults may create a potentially vicious cycle that influenced early change in frailty and continued to cause late change in loneliness.

Conclusion

A bidirectional relationship may exist between loneliness and frailty among older Chinese adults over 60 years old. Lonely older adults should be alerted to the potential self-reinforcing cycle of loneliness that affects their health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03044-0.

Associations of face-to-face and non-face-to-face social isolation with all-cause and cause-specific mortality: 13-year follow-up of the Guangzhou Biobank Cohort study

BACKGROUND

Although social isolation has been associated with a higher mortality risk, little is known about the potential different impacts of face-to-face and non-face-to-face isolation on mortality. We examined the prospective associations of four types of social isolation, including face-to-face isolation with co-inhabitants and non-co-inhabitants, non-face-to-face isolation, and club/organization isolation, with all-cause and cause-specific mortality separately.

METHODS

This prospective cohort study included 30,430 adults in Guangzhou Biobank Cohort Study (GBCS), who were recruited during 2003-2008 and followed up till Dec 2019.

RESULTS

During an average of 13.2 years of follow-up, 4933 deaths occurred during 396,466 person-years. Participants who lived alone had higher risks of all-cause (adjusted hazard ratio (AHR) 1.24; 95% confidence interval (CI) 1.04-1.49) and cardiovascular disease (CVD) (1.61; 1.20-2.03) mortality than those who had ≥ 3 co-habitant contact after adjustment for thirteen potential confounders. Compared with those who had ≥ 1 time/month non-co-inhabitant contact, those without such contact had higher risks of all-cause (1.60; 1.20-2.00) and CVD (1.91; 1.20-2.62) mortality. The corresponding AHR (95% CI) in participants without telephone/mail contact were 1.27 (1.14-1.42) for all-cause, 1.30 (1.08-1.56) for CVD, and 1.37 (1.12-1.67) for other-cause mortality. However, no association of club/organization contact with the above mortality and no association of all four types of isolation with cancer mortality were found.

CONCLUSIONS

In this cohort study, face-to-face and non-face-to-face isolation were both positively associated with all-cause, CVD-, and other-cause (but not cancer) mortality. Our finding suggests a need to promote non-face-to-face contact among middle-aged and older adults.

Social Relationships, Wealth, and Cardiometabolic Risk: Evidence from a National Longitudinal Study of U.S. Older Adults

Objectives: To investigate multiple dimensions of social relationships related to biomarkers of cardiometabolic health and how their associations vary by wealth in older adults. Methods: Growth curve models were used to investigate the longitudinal associations between measures of both positive and negative social relationships and cardiometabolic risk (CMR) over a 10-year period from 2006 to 2016 and the moderation of this association by wealth in the Health and Retirement Study (HRS). Results: Older adults with better social relationships had lower CMR on average. The protective effects of positive social relationships, however, waned at older ages, particularly for low-wealth individuals. Discussion: Our results suggest that good social relationships promote healthy aging by buffering against harmful cardiometabolic consequences of psychosocial stress, particularly among relatively wealthy individuals. Efforts to improve old age health would be more effective when focusing simultaneously on fostering social connections and boosting financial resources.

The prevalence of loneliness across 113 countries: systematic review and meta-analysis

OBJECTIVES

To identify data availability, gaps, and patterns for population level prevalence of loneliness globally, to summarise prevalence estimates within World Health Organization regions when feasible through meta-analysis, and to examine temporal trends of loneliness in countries where data exist.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Embase, Medline, PsycINFO, and Scopus for peer reviewed literature, and Google Scholar and Open Grey for grey literature, supplemented by backward reference searching (to 1 September 2021) ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Observational studies based on nationally representative samples (n≥292), validated instruments, and prevalence data for 2000-19. Two researchers independently extracted data and assessed the risk of bias using the Joanna Briggs Institute checklist. Random effects meta-analysis was conducted in the subset of studies with relatively homogeneous research methods by measurement instrument, age group, and WHO region.

RESULTS

Prevalence data were available for 113 countries or territories, according to official WHO nomenclature for regions, from 57 studies. Data were available for adolescents (12-17 years) in 77 countries or territories, young adults (18-29 years) in 30 countries, middle aged adults (30-59 years) in 32 countries, and older adults (≥60 years) in 40 countries. Data for all age groups except adolescents were lacking outside of Europe. Overall, 212 estimates for 106 countries from 24 studies were included in meta-analyses. The pooled prevalence of loneliness for adolescents ranged from 9.2% (95% confidence interval 6.8% to 12.4%) in South-East Asia to 14.4% (12.2% to 17.1%) in the Eastern Mediterranean region. For adults, meta-analysis was conducted for the European region only, and a consistent geographical pattern was shown for all adult age groups. The lowest prevalence of loneliness was consistently observed in northern European countries (2.9%, 1.8% to 4.5% for young adults; 2.7%, 2.4% to 3.0% for middle aged adults; and 5.2%, 4.2% to 6.5% for older adults) and the highest in eastern European countries (7.5%, 5.9% to 9.4% for young adults; 9.6%, 7.7% to 12.0% for middle aged adults; and 21.3%, 18.7% to 24.2% for older adults).

CONCLUSION

Problematic levels of loneliness are experienced by a substantial proportion of the population in many countries. The substantial difference in data coverage between high income countries (particularly Europe) and low and middle income countries raised an important equity issue. Evidence on the temporal trends of loneliness is insufficient. The findings of this meta-analysis are limited by data scarcity and methodological heterogeneity. Loneliness should be incorporated into general health surveillance with broader geographical and age coverage, using standardised and validated measurement tools.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019131448.

Social isolation, social support, and loneliness and their relationship with cognitive health and dementia

BACKGROUND

Poor social health is prevalent in older adults and may be associated with worse cognition, and increased dementia risk. The aim of this study was to determine whether social isolation, social support and loneliness are independently associated with cognitive function and incident dementia over 5 years in older adults, and to investigate potential gender differences.

METHODS

Participants were 11,498 community-dwelling relatively healthy Australians aged 70-94, in the ASPREE Longitudinal Study of Older Persons (ALSOP). Social isolation, social support, loneliness and cognitive function were assessed through self-report. Outcomes examined were cognitive decline (>1.5 SD decline in cognitive performance since baseline) and incident dementia (adjudicated according to DSM-IV criteria).

RESULTS

Most participants self-reported good social health (92%) with very few socially isolated (2%), with low social support (2%) or lonely (5%). Among women, social isolation and low social support were consistently associated with lower cognitive function (e.g., social support and cognition β = -1.17, p < 0.001). No consistent longitudinal associations were observed between baseline social health and cognitive decline (over median 3.1 years) or incident dementia (over median 4.4 years; social isolation: HR = 1.00, p = 0.99; low social support: HR = 1.79, p = 0.11; loneliness: HR = 0.72, p = 0.34 among women and men).

CONCLUSION

Our study provides evidence that social isolation and a low social support are associated with worse cognitive function in women, but not men. Social health did not predict incident cognitive decline or dementia, but we lacked power to stratify dementia analyses by gender.