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

Prolonged loneliness and risk of incident cognitive decline and dementia: A two-cohort study

BACKGROUND

Loneliness is prevalent currently and could result in increased dementia risks, whereas the associations of prolonged loneliness and its changes with cognitive decline and dementia remain less investigated.

METHODS

Data were from the English Longitudinal Study of Ageing (ELSA) and Health and Retirement Study (HRS). Loneliness was assessed using the Revised UCLA Loneliness Scale. Health risk factors for dementia included unhealthy lifestyles, depressive symptoms, chronic diseases, and functional limitations. Cognitive function was assessed using validated tests in both cohorts, with cognitive decline defined as cognitive z-scores < -1.5. Dementia was identified through self- or proxy-reported physician diagnoses. The Cox proportional hazard regression and Aalen's additive hazard regression were performed to calculate the relative and absolute risk for cognitive decline and dementia, respectively. Covariates including socio-demographic characteristics, social networks, and polygenic scores were adjusted.

RESULTS

Of 6721 ELSA and 10,195 HRS participants aged ≥50y, 2129 (13.7 %) and 612 (3.6 %) developed incident cognitive decline and dementia in about 10 years, respectively. Participants with severe (versus no) cumulative loneliness had 42 % and 98 % higher cognitive decline and dementia risks after pooling, corresponding to 791.6 (477.4-1105.8) and 372.8 (223.6-522.0) excess incidence densities (/105 person-years). Additionally, those who recovered from frequent loneliness (versus persistent frequent) were 9 %-31 % less likely to develop unhealthy lifestyles, depressive symptoms, chronic diseases, and functional limitations, and were at 33 % lower risks of dementia, corresponding to -248.6 (-446.0 ~ -51.2) excess incidence density.

CONCLUSIONS

Prolonged loneliness could increase the risks of incident cognitive decline and ADRD, while alleviating loneliness may help.

Loneliness and cognition in older adults: A meta-analysis of harmonized studies from the United States, England, India, China, South Africa, Mexico, and Chile

BACKGROUND

Loneliness is a risk factor for late-life dementia. There is less consistent evidence of its association with cognitive performance. This study examined the replicability of the association between loneliness and overall and domain-specific cognitive function and informant-rated cognitive decline in cohorts from seven countries: the United States, England, India, China, South Africa, Mexico, and Chile.

METHODS

Data were from the Harmonized Cognitive Assessment Protocol administered in seven population-based studies (total N > 20,000). Participants reported their loneliness, completed a battery of cognitive tests, and nominated a knowledgeable informant to rate their cognitive decline. Random-effect meta-analyses were used to summarize the associations from each cohort.

RESULTS

Loneliness was associated with poor overall cognitive performance and informant-rated cognitive decline controlling for sociodemographic factors (meta-analytic correlation for overall cognition = -.10 [95% CI = -.13, -.06] and informant-rated decline = .16 [95% CI = .14, .17]). Despite some heterogeneity, the associations were significant across samples from Africa, Asia, Europe, North, Central, and South America. The meta-analysis also indicated an association with specific cognitive domains: episodic memory, speed-attention, visuospatial abilities, numeric reasoning, and verbal fluency. The associations were attenuated but persisted when depressive symptoms were added as a covariate. Depression, cognitive impairment, and sociodemographic factors did not consistently moderate the associations across samples.

CONCLUSIONS

Loneliness is associated with poor performance across multiple domains of cognition and observer-rated cognitive decline, associations that replicated across diverse world regions and cultures.

Trajectories of loneliness in later life - Evidence from a 10-year English panel study

The prevalence of loneliness is higher among older people; however, few studies have examined its longitudinal patterns and associated risk factors, particularly social network resources. Using data from six waves of the English Longitudinal Study of Ageing (2008/09 to 2018/19, N = 4740) and group-based trajectory modelling (GBTM), we identified five groups of loneliness trajectories: three with stable levels (37% "stable low"; 26% "stable medium"; 9% "stable high") and two with time-varying scores of loneliness (8% "increasing"; 20% "decreasing"). Multinomial regression models and GBTM were used to examine baseline and time-varying factors associated with these trajectories. We created composite measures to capture the presence and key facets of social network resources (including size, support, closeness, and frequency of contact) for four different social relationship domains (partner, children, immediate family, and friends). Our results show that, among those with family or friends, older people with higher social network resources and those who maintained or improved them over time reported lower levels of loneliness. Findings also suggest that all social relationship domains contributed to feelings of loneliness in later life. Also, we find that respondents in poor health and depressed, as well as those whose health deteriorated over time, were more likely to have stable high or increasing levels of loneliness. The study highlights the need to investigate loneliness from a life course perspective, account for the complexity of social relationships in later life beyond their mere presence or absence, and include their quality and quantity as well as multiple domains of family and intergenerational relationships.

A Meta-analysis of Loneliness and Risk of Dementia using Longitudinal Data from >600,000 Individuals

Loneliness is one critical risk factor for cognitive health. Combining data from ongoing aging studies and the published literature, we provided the largest meta-analysis on the association between loneliness and dementia (k = 21 samples, N = 608,561) and cognitive impairment (k = 16, N = 103,387). Loneliness increased risk for all-cause dementia (HR = 1.306, 95% CI [1.197,1.426]), Alzheimer's disease (HR = 1.393, 95% CI [1.290,1.504]; k = 5), vascular dementia (HR = 1.735, 95% CI [1.483,2.029]; k = 3), and cognitive impairment (HR = 1.150, 95% CI [1.113,1.189]). The associations persisted when models controlled for depression, social isolation, and/or other modifiable risk factors for dementia. The large heterogeneity across studies was partly due to differences in loneliness measures and ascertainment of cognitive status. Results underscored the importance to further examine type/sources of loneliness and cognitive symptoms to develop effective interventions that reduce the risk of dementia.

Effects of physical and psychological multimorbidity on the risk of dementia: multinational prospective cohorts and a meta-analysis

BACKGROUND

Previous studies only considered the impact of a single physical or psychological disorder on dementia. Our study investigated the association of physical and psychological multimorbidity with dementia among older adults using two multinational prospective cohorts to supplement the limited joint evidence.

METHODS

We utilized the Health and Retirement Study (HRS 2012 to 2018) in the United States (US) and the Survey of Health, Ageing and Retirement in Europe (SHARE 2012 to 2018). Physical disorder was defined as any one of seven self-reported physician-diagnosed conditions. Psychological disorder was assessed using the 8-item Center for Epidemiologic Research Depression (CES-D) scale or the EURO-D. Dementia was determined through a combination of self-reported physician diagnosis of dementia or Alzheimer's disease, or the 27-point HRS cognitive scale. Competing risk models were utilized to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CI). DerSimonian-Laird random-effects meta-analyses were conducted to obtain pooled estimates.

RESULTS

The prevalence of physical and psychological multimorbidity was 17.29% (1027/5939) in continental Europe and 15.52% (1326/8543) in the US. The incidence of dementia was 6.21 per 1000 person-years in continental Europe and 8.27 per 1000 person-years in the US, respectively. It was highest among participants with physical and psychological multimorbidity in continental Europe (10.46 per 1000 person-years) and the US (14.82 per 1000 person-years), compared with the other three groups. In the univariate model, participants who reported physical and psychological multimorbidity had a higher risk of dementia compared with those who reported no physical and psychological disorders in continental Europe (HR = 2.59; 95% CI: 1.55, 4.33) and the US (HR = 4.11; 95% CI: 2.44, 6.94). After adjusting all covariates, the risk of dementia among participants who reported physical and psychological multimorbidity increased by 86% in continental Europe (aHR = 1.86; 95% CI: 1.08, 3.21) and by 176% in the US (aHR = 2.76; 95% CI: 1.61, 4.72), respectively. After pooling the outcomes, the risk of dementia among participants who reported physical and psychological multimorbidity increased by 115% (aHR = 2.15; 95% CI: 1.27, 3.03).

CONCLUSIONS

Physical and psychological multimorbidity was prevalent among older adults in the US and continental Europe. Given the consistent associations with dementia, it is imperative to increase awareness of the links and recognize the limitations of single-disorder care. Specific attention should be given to providing care coordination.

Adult child educational attainment and older parents' psychosocial outcomes during the COVID-19 pandemic

BACKGROUND

Older adults' psychosocial outcomes during the COVID-19 pandemic have been inequitable by socio-economic status (SES). However, studies have focused solely on own SES, ignoring emerging evidence of the relationship between adult child SES and late-life health. We evaluated whether adult child educational attainment - a core marker of SES - is associated with older parents' psychosocial outcomes during the pandemic.

METHODS

We used data from the Survey of Health, Aging, and Retirement in Europe (SHARE) 2004-2018 and the SHARE Corona Surveys (SCS) 2020 and 2021. We included 40,392 respondents ≥ 65 years who had pre-pandemic information on adult child educational attainment and self-reported psychosocial outcomes during the pandemic, including self-assessments of worsened psychosocial outcomes compared to the pre-pandemic period. We used generalized estimating equations with a Poisson distribution and a log link, adjusted for respondent and family-level characteristics, including respondents' own educational attainment.

RESULTS

Older adults whose adult children averaged levels of educational attainment at or above (vs. below) their country-specific mean had a lower prevalence of feeling nervous (Prevalence Ratio [PR]: 0.94, 95% Confidence Interval [CI]: 0.90, 0.97), sad or depressed (PR: 0.94, 95% CI: 0.91, 0.98), and having sleep problems (PR: 0.94, 95% CI: 0.90, 0.97) during the pandemic. Additionally, higher adult child educational attainment was associated with a lower risk of perceiving worsened feelings of nervousness (PR: 0.95, 95% CI: 0.90, 1.01) and worsened sleep problems (PR: 0.91, 95% CI: 0.82, 1.01) as compared to the pre-pandemic. In stratified models, protective associations were observed only in countries experiencing "high" levels of COVID-19 intensity at the time of the survey. All of these results are derived from adjusted models.

CONCLUSIONS

Adult child SES may have "upward" spillover effects on the psychosocial wellbeing of older parents during periods of societal duress like the pandemic.

The impact of a diabetes diagnosis on health and well-being: Findings from the English Longitudinal Study of Ageing

BACKGROUND

Poorer health and well-being are associated with diabetes risk. However, little is known about the trajectory of health and well-being from before to after diabetes diagnosis. We compared depressive symptoms, quality of life, self-rated health, and loneliness at three time points (prediagnosis, diagnosis, 2-4 years post diagnosis) in individuals who developed diabetes and a comparison group.

METHODS

Health and well-being measures were self-reported by 3474 participants from the English Longitudinal Study of Ageing. Repeated measures analysis of variance and generalized estimating equations were used to investigate differences by group, time, and group-by-time interactions.

RESULTS

A total of 473 (13.6%) participants developed diabetes. The diabetes group reported greater depressive symptoms (W2(1) = 20.67, p < .001) and lower quality of life (F = 1, 2535 = 10.30, p = .001) and were more likely to rate their health as fair/poor (W2(1) = 67.11, p < .001) across time points, adjusting for age, sex, and wealth. They also reported greater loneliness (F = 1, 2693 = 9.70, p = .002) in unadjusted analyses. However, this was attenuated to the null in adjusted analyses. The group-by-time interaction was significant for quality of life (F = 1.97, 5003.58 = 5.60, p = .004) and self-rated health (W2(2) = 11.69, p = .003), with a greater decline in these measures over time in the diabetes group in adjusted analyses.

CONCLUSION

People who received a diabetes diagnosis had greater depressive symptoms, lower quality of life, and poorer self-rated health than those who did not develop diabetes. Quality of life and self-rated health deteriorated more rapidly following a diagnosis. Screening for these factors around the time of diagnosis could allow for interventions to improve the health and well-being of those with diabetes.

The Grip Strength Loss Rate and the Subsequent Cognitive Decline Rate in Older Adults: The Moderating Role of Social Isolation

Background and Objectives

Accumulating evidence suggests that low grip strength (GS) is associated with a faster cognitive decline, but most previous studies have measured GS at a single time point, ignoring changes in GS. We aimed to explore the association of the GS loss rate with the sequent cognitive decline, as well as the moderating role of social isolation in older adults.

Research Design and Methods

Data were from the English Longitudinal Study of Ageing. Absolute and relative GS loss rates were calculated as the annual losses from Wave 2 (2004-05) to Wave 4 (2008-09). Participants were divided into 3 groups according to the tertiles of GS loss rates. Linear mixed models were used to assess the association of the GS loss rate during Waves 2-4 with the cognitive decline rate during Waves 4-9 (Wave 9, 2018-19).

Results

Of the 4 356 participants included in analyses, 1 938 (44.5%) were men, with a mean age of 68.4 (SD: 8.4) years. Compared with Tertile 1 of the absolute GS loss rate, Tertile 2 (β = -0.009 [95% CI: -0.018 to -0.001] SD/year) and Tertile 3 (β = -0.018 [95% CI: -0.027 to -0.010] SD/year) were associated with a faster cognitive decline rate. The results of relative GS were similar to those of absolute GS. Social isolation was a significant modifier in the associations of the absolute GS loss rate with decline rates in global cognition and episodic memory, but not in temporal orientation. We did not observe that social isolation moderated the association of the relative GS loss rate with the cognitive decline rate.

Discussion and Implications

Both absolute and relative GS loss rates were positively associated with the cognitive decline rate in older adults. Low social isolation scores attenuated the association of the absolute GS loss rate with the cognitive decline rate.

The trajectory of depressive symptoms over time and the presence of depressive symptoms at a single time point with the risk of dementia among US older adults: A national prospective cohort study

AIM

This study aims to assess the association between trajectories of depressive symptoms and the risk of dementia, and to compare the predictive ability of trajectories using multiple data points with depressive symptoms at a single data point.

METHODS

We included 5306 older adults from the Health and Retirement Study. We assessed depressive symptoms using the Center for Epidemiology Depression Scale (CES-D), and identified its 8- year trajectories (2002-2010) using latent class trajectory modeling. We calculated hazard ratios (HR) using Cox proportional hazards models. The concordance index (C-index) was used to compare the discriminative power of the models.

RESULTS

We identified two trajectories of depressive symptoms, characterized by maintaining low CES-D scores, and moderate starting scores that steadily increased throughout the follow-up period. During 40,199 person-years, compared to the low trajectory, the increasing trajectory of depressive symptoms was associated with a higher risk of dementia (HR = 1.35; 95% CI: 1.09-1.67) (C-index = 0.759). For every point increase in the degree of depressive symptoms (CES-D scores) in 2010, the risk of dementia increased by 7% (95% CI: 1.03-1.12) (C-index = 0.760). The presence of depressive symptoms (CES-D scores ≥3) in 2010 was not associated with an increased risk of dementia (HR = 1.18; 95% CI: 0.98-1.43) (C-index = 0.759). The C-index values of cox models showed similar discriminative power.

CONCLUSIONS

The increasing trajectory of depressive symptoms at multiple data points and the degree of depressive symptoms at a single data point were associated with an increased risk of subsequent dementia among older adults.

Association of cumulative loneliness with all-cause mortality among middle-aged and older adults in the United States, 1996 to 2019

Loneliness is a growing public health concern worldwide. We characterized the association between cumulative loneliness and subsequent all-cause mortality, using data from 9,032 participants aged 50+ in the population-based US Health and Retirement Study (HRS) from 1996 to 2019. Loneliness status (yes; no) was measured biennially from 1996 to 2004, and we categorized the experience of cumulative loneliness over the 8-y period as never, one time point, two time points, and ≥three time points. A multivariable-adjusted age-stratified Cox proportional hazards regression model was fitted to examine the association between cumulative loneliness from 1996 to 2004 and all-cause mortality from 2004 to 2019. Excess deaths due to each category of cumulative loneliness were calculated. Compared to those who never reported loneliness from 1996 to 2004, participants experiencing loneliness at one time point, two time points, and ≥three time points respectively had 1.05 (95% CI: 0.96 to 1.15), 1.06 (95% CI: 0.95 to 1.19), and 1.16 (95% CI: 1.02 to 1.33) times higher hazards of mortality from 2004 to 2019 (P trend = 0.01). These results correspond to 106 (95% CI: 68 to 144), 202 (95% CI: 146 to 259), and 288 (95% CI: 233 to 343) excess deaths per 10,000 person-years, for those experiencing loneliness at each of one, two, or ≥three time points from 1996 to 2004. Cumulative loneliness in mid-to-later life may thus be a mortality risk factor with a notable impact on excess mortality. Loneliness may be an important target for interventions to improve life expectancy in the United States.

Pet Ownership, Living Alone, and Cognitive Decline Among Adults 50 Years and Older

Importance

It remains unclear whether pet ownership is associated with cognitive decline and to what extent pet ownership mitigates the association between living alone and cognitive decline.

Objective

To explore the association of pet ownership with cognitive decline, the interaction between pet ownership and living alone, and the extent to which pet ownership mitigates the association between living alone and cognitive decline in older adults.

Design, Setting, and Participants

This cohort study used data from waves 5 (June 2010 to July 2011) to 9 (from June 2018 to July 2019) in the English Longitudinal Study of Ageing. Participants included adults 50 years and older. Data were analyzed from April 1 to June 30, 2023.

Exposures

Pet ownership and living alone in wave 5.

Main Outcomes and Measures

In waves 5 to 9, verbal memory and verbal fluency were assessed, and composite verbal cognition was further calculated.

Results

Of the 7945 participants included, the mean (SD) age was 66.3 (8.8) years, and 4446 (56.0%) were women. Pet ownership was associated with slower rates of decline in composite verbal cognition (β = 0.008 [95% CI, 0.002-0.014] SD/y), verbal memory (β = 0.006 [95% CI, 0.001-0.012] SD/y), and verbal fluency (β = 0.007 [95% CI, 0.001-0.013] SD/y). Three-way interaction tests showed that living alone was a significant modifier in all 3 associations. Stratified analyses showed that pet ownership was associated with slower rates of decline in composite verbal cognition (β = 0.023 [95% CI, 0.011-0.035] SD/y), verbal memory (β = 0.021 [95% CI, 0.008-0.034] SD/y), and verbal fluency (β = 0.018 [95% CI, 0.005-0.030] SD/y) among individuals living alone, but not among those living with others. Joint association analyses showed no significant difference in rates of decline in composite verbal cognition, verbal memory, or verbal fluency between pet owners living alone and pet owners living with others.

Conclusions and Relevance

In this cohort study, pet ownership was associated with slower rates of decline in verbal memory and verbal fluency among older adults living alone, but not among those living with others, and pet ownership offset the associations between living alone and declining rates in verbal memory and verbal fluency. Further studies are needed to assess whether pet ownership slows the rate of cognitive decline in older adults living alone.

Combating Social Isolation in Older Adults: An Intergenerational Nursing Communication Project

The importance of social connection to health and well-being has long been recognized. Social isolation is prevalent and impactful in the lives of older adults across care settings. A semester-long communication-focused clinical project was developed and piloted with sophomore Bachelor of Nursing Science students during Fall 2020 and replicated in Fall 2021 and 2022. Students were paired with older adult volunteers/mentors from a senior living organization and contacted mentors every 2 weeks over the 15-week semester. Older adult volunteers served as mentors, sharing their wisdom and life experiences. Students practiced their communication skills and learned about their mentor's life. Pre- and post-activity surveys of student attitudes toward older adults/aging suggested a dramatic and positive shift in perspective, and mentors rated the experience highly favorably. Intergenerational communication and relationship building has the potential to combat social isolation, promote healing and growth, and enable mutually beneficial engagement. [Journal of Psychosocial Nursing and Mental Health Services, 61(10), 7-11.].