Sleep Quality Partially Mediate the Relationship Between Depressive Symptoms and Cognitive Function in Older Chinese: A Longitudinal Study Across 10 Years

The bidirectional relationships between social isolation and cognitive function among older adults in China: separating between-person effects from within-person effects

This study investigates the bidirectional relationship between social isolation and cognitive function among older adults in China, utilizing data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The baseline survey, which commenced in 2008, tracked 1,662 participants over four waves of data collection spanning a decade. We employed Cross-Lagged Panel Models (CLPM) and Random Intercept Cross-Lagged Panel Models (RI-CLPM) to analyze these relationships at both the between-person and within-person levels. CLPM results indicated significant cross-lagged effects between social isolation (β = - 0.119, p < 0.001; β = - 0.162, p < 0.001) and cognitive function (β = - 0.073, p < 0.001; β = - 0.091, p < 0.001) at the between-person level over the last three waves. Specifically, higher prior levels of social isolation were associated with a significant decline in subsequent cognitive function, and vice versa. Furthermore, RI-CLPM results showed that, after controlling for random intercepts and covariates, only social isolation had a significant negative impact on cognitive function across all waves (β = - 0.051, p < 0.05; β = - 0.047, p < 0.05; β = - 0.028, p < 0.05). Overall, this study demonstrates that, when considering both between-person and within-person effects, social isolation exerts a stronger lag effect on cognitive function among older adults in China. This suggests that, over a specific timeframe, reducing social isolation is crucial for promoting healthy aging in this population.

Association of sleep quality and its change with the risk of depression in middle-aged and elderly people: A 10-year cohort study from England

BACKGROUND

Persistently poor sleep quality in young adults is linked to a higher risk of depression. However, the impact of changes in sleep quality on depression risk in middle-aged and older adults remain unclear. This study investigates the association between sleep quality, its changes, and the risk of depression in middle-aged and elderly people.

METHODS

We included 4007 participants (mean age 63.0 ± 7.6 years, 53.0 % women) from the English Longitudinal Study of Ageing. Sleep quality was assessed using the Jenkins Sleep Problems Scale and a global sleep quality question. Depression was evaluated with the Center for Epidemiological Studies Depression Scale and self-reported doctor-diagnosed depression. Multivariable logistic regression, restricted cubic spline curve, and mediation analysis was employed.

RESULTS

After 10 years of follow-up, 777 individuals developed depression. Sleep quality scores positively correlated with depression risk. Among those with good sleep quality, worsening sleep quality increased depression risk (OR = 1.67, 95 % CI: 1.21-2.31). For those with intermediate sleep quality, improved sleep quality reduced depression risk (OR = 0.70, 95 % CI: 0.50-0.98). Conversely, worsening sleep quality increased depression risk (OR = 2.11, 95 % CI: 1.47-3.02). Pain and functional disability partially mediated the association between intermediate/poor sleep quality and depression (9.8 % and 4.2 %, respectively).

LIMITATIONS

Sleep quality is based on self-reported.

CONCLUSIONS

Intermediate, poor, and worsening sleep quality are linked to higher depression risk. Improving sleep quality mitigates depression risk in those with intermediate sleep quality. Sleep quality may influence depression indirectly through pain and functional disability.

The effects of sleep quality on loneliness among older adults: cohort analysis from the life course perspective

BACKGROUND

Using cohort analysis to examine the effects of sleep quality on loneliness among older adults from the life course perspective.

METHODS

The hierarchical age-period-cohort growth curve model was used to analyze the data from the 2005-2018 Chinese Longitudinal Healthy Longevity Survey (CLHLS).

RESULTS

(1) Loneliness has a 'U' curve relationship with age, but with the rate of increase gradually slowing down. (2) There were significant differences in loneliness across birth cohorts, with younger cohorts having higher predicted loneliness than older cohorts at the same age. (3) The influence of different sleep quality on loneliness showed a trend of increasing with age. (4) There were no significant differences in the impact of sleep quality on loneliness in different cohorts.

CONCLUSIONS

This study has identified heterogeneity in loneliness, emphasising the need for a diversified intervention approach. Sleep quality has a protective effect on loneliness and is easy to assess, making it an important intervention tool. In addition, it is imperative to account for the influences of age and cohort effects when formulating intervention strategies.

Mediation analysis of cognitive function in the relationship between pulmonary function and depression among middle-aged and older adults

AIM

This study aims to explore the association between declining lung function and depression in middle-aged and older adults, with a special focus on the mediating role of cognitive function.

METHODS

This study utilizes self-reported and physical examination data from 5345 individuals participating in the 2015 cycle of the China Health and Retirement Longitudinal Study (CHARLS) to explore the role of cognitive function changes in mediating the effects of diminished lung function on depression among middle-aged and older adults.

RESULTS

Multivariate linear regression analysis revealed a positive correlation between pulmonary and cognitive functions (β = 0.003, 95% CI: 0.002∼0.003, P < 0.01) and a negative correlation between cognitive function and depression (β = -0.279, 95% CI: -0.330-0.228, P < 0.01). Cognitive function plays a mediating role in linking pulmonary function with depression, exhibiting a mediation effect of -0.0007 and a total effect of -0.0046, wherein the mediation effect contributes to 15.22% of the total effect. For females, the mediating effect of cognitive function was stronger (β = -0.0013, 95% CI: -0.0018∼-0.0008, P < 0.01) than it was for males (β = -0.0006, 95% CI: -0.0009∼-0.0003, P < 0.01).

CONCLUSIONS

The study underscores the importance of monitoring lung and cognitive functions as interconnected factors contributing to the mental health of middle-aged and older adults. It suggests that interventions aimed at improving pulmonary health and cognitive function may help mitigate depressive symptoms among middle-aged and older adults. Further research is warranted to validate these findings across diverse cultural and demographic settings. Geriatr Gerontol Int 2024; 24: 1210-1217.

Association between diverse obesity indicators and sleep quality in elderly Chinese people: a National Study

Background

The association between obesity indicators and sleep quality remains unclear among elderly Chinese people. Therefore, we aimed to assess this association by utilizing data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

Methods

A total of 10,505 participants aged 65 and above from the 2018 CLHLS were included. Calculate body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and weight-adjusted-waist index (WWI) based on measured weight, height, and waist circumference. Based on BMI values, individuals were classified as underweight (<18.5 kg/m2), normal weight (18.5-23.9 kg/m2) and overweight or obesity (BMI ≥24 kg/m2). In the survey, sleep quality was rated in a 5-point format ("1 = very good," "2 = good," "3 = fair," "4 = poor," or "5 = very poor"), and we categorized "1" and "2" as good sleep quality and "3," "4," and "5" as poor sleep quality. Logistic regression models were used to evaluate odds ratios (ORs) and 95% confidence intervals (CIs), with subgroup analysis and restricted-cubic-spline (RCS) conducted.

Results

The prevalence of poor sleep quality was 47.06%. There are significant differences in obesity indicators and other factors between the two groups of people with good sleep and poor sleep. After adjusting for potential confounding factors (including demographics, socioeconomic status, lifestyle behaviors, health-related issues and activities of daily living), our analyses revealed significant negative associations of BMI [OR 0.96 (95% CI 0.95-0.98)], WC [OR 0.99 (95% CI 0.98-0.99)] and WHtR [OR 0.18 (95% CI 0.09-0.35)] with poor sleep quality. RCS regression also showed that BMI, WC, WHtR and WWI were all strongly negatively correlated with poor sleep quality.

Conclusions

In elderly Chinese people, overweight/obese elderly people may have a better sleep quality compared to elderly people with normal weight, while underweight elderly people are unfavorable for sleep quality.

The activities of daily living partially mediate the relationship between rapid eye movement sleep behavior disorder and depressive symptoms in Parkinson's disease

Objective

A longitudinal study was conducted to investigate whether rapid eye movement sleep behavior disorder affect depression in patients with Parkinson's disease through activities of daily living.

Methods

A total of 387 Parkinson's disease patients' six-year follow-up data (one follow-up per year) were obtained from the Parkinson's Progression Markers Initiative. To allow causal effects to manifest, this study increased the lag period and divided the data from the six follow-ups into two groups: wave 1 (wave refers to time points), wave 3, and wave 5 as one group, and wave 2, wave 4, and wave6 as the other group. The time interval between two time points in each group was two years. To comprehensively and deeply analyze the dynamic relationships between variables, accurately infer causal relationships, control for individual differences, and detect the stability of these relationships, this study constructed the fixed effects cross-lagged panel model (CLPM), the random effects CLPM (RE-CLPM) model, and the Equating CLPM and Equating RE-CLPM models with applied restriction conditions. Additionally, a reverse path was added to verify the reverse prediction effect. The most suitable data analysis model was selected to explore the relationships between the study variables. Furthermore, the longitudinal mediating effect of daily living activities between rapid eye movement sleep behavior disorder and depression was investigated.

Results

In the models, Equating cross-lagged panel model was the best. The lag effect was positive and significant. In wave 1, 3, 5, activities of daily living mediated 11.82% on the path from rapid eye movement sleep behavior disorder to depression; in wave 2, 4, 6, it mediated 13.13%. Therefore, attention should be paid to the treatment of activities of daily living.

Conclusion

Longitudinal changes in activities of daily living have indirect effects on the relationship between rapid eye movement sleep behavior disorder and depression, which highlights the importance of changes in activities of daily living ability in Parkinson's disease patients with rapid eye movement sleep behavior disorder.

Parent-child relationship, parenting behaviors, and adolescents' depressive symptoms after an earthquake: unraveling within-adolescent associations from between-adolescent differences

This study assessed temporal associations between parent-child relationship, parenting behaviors (i.e., warmth, rejection, and overprotection), and adolescents' depressive symptoms after trauma, using random-intercept cross-lagged panel models to distinguish between- and within-adolescent differences. We surveyed Chinese adolescents 12 (Aug 2018; T1), 21 (May 2019; T2), 27 (Nov 2019; T3) months after the Jiuzhaigou earthquake that occurred in August 2017. Of the 585 adolescents who participated in at least two waves of the study, mean age at T1 was 15.50 years old (SD = 1.58 years) and 57.8% were girls. Controlling adolescents' gender, age, ethnicity, trauma exposure at T1, and parents' marital status, between-adolescent results showed that parent-child relationship and parenting behaviors, parent-child relationship and depressive symptoms were correlated across models of parental warmth, rejection, and overprotection, whereas depressive symptoms were only correlated with parental rejection and overprotection. Within-adolescent results indicated that parent-child relationship and adolescents' depressive symptoms had bidirectional associations via the mediation of parental warmth from T1 to T3. Over the longer term following the earthquake, we found that parental rejection was bidirectionally associated with adolescents' depressive symptoms, whereas parental overprotection was unidirectionally influenced by adolescents' depressive symptoms from T2 to T3. In addition, more depressive symptoms in adolescents were associated with worsening parent-child relationship from T2 to T3. In conclusion, shortly after trauma, interventions should focus on improving parent-child relationship and relieving adolescents' depressive symptoms. Over the longer term after trauma, relieving adolescents' depressive symptoms should be prioritized to avoid its eroding effects on parent-child relationship and parenting behaviors, and to break the "vicious cycle".

Association between total cholesterol and all-cause mortality in oldest old: a national longitudinal study

Background

A common sense is that lower serum cholesterol levels are better. However, a growing number of researches have questioned this especially for the oldest old. The current study was to assess the association between total cholesterol and all-cause mortality in a group of people aged 85 years old and over.

Methods

We selected 903 Chinese old participants who aged ≥85 years from the Chinese Longitudinal Healthy Longevity Survey(CLHLS) at baseline in 2012. The participants were followed up until death or until December 31, 2014. The outcome was all-cause mortality. The univariate and multivariate Cox regression analyses were used to estimate risk levels of all-cause mortality. We stratified the participants into three groups (<3.40, 3.40-4.39, ≥4.39 mmol/L) based on the restricted cubic splines methods. The survival probability according to total cholesterol category was calculated using the Kaplan-Meier curves, and the log-rank test was performed to analyze differences between the groups.

Results

During the follow-up of three years, 282 participants died, 497 survived and 124 lost to follow-up. There was significant relationship between the total cholesterol and lower risk of all-cause mortality in the multivariable Cox regression analysis (HR=0.88, 95% CI: 0.78-1.00). Based on the restricted cubic splines methods, the total cholesterol was converted from a continuous variable to a categorical variable. The populations were divided into three groups (<3.40, 3.40-4.39, ≥4.39 mmol/L) according to the total cholesterol categorized by cutoff values. Compared to the total cholesterol level of <3.40 mmol/L, populations in the total cholesterol level of 3.40-4.39 mmol/L (HR = 0.72, 95% CI: 0.53-0.97) and ≥4.39 mmol/L (HR = 0.71, 95% CI: 0.52-0.96) groups had lower all-cause mortality in multivariate Cox regression analysis and higher survival probability in survival analysis. When two groups were divided, similar results were found among the populations in the total cholesterol level of ≥3.40 mmol/L compared to the populations in the total cholesterol level of <3.40 mmol/L groups.

Conclusion

In oldest old aged 85 and older, serum total cholesterol levels are inversely associated with all-cause mortality. This study suggested that total cholesterol should be maintained to acceptable levels (≥ 3.40 mmol/L) in oldest old to achieve longevity.

Estimating the impact of different types hearing loss on cognitive decline and the joint effect of hearing loss and depression on cognitive decline among older adults in China

BACKGROUND

Current research lacks examination of the relationship between different subtypes of hearing loss (HL) and cognitive decline (CD). Additionally, the co-effects of HL and depression on CD remain unexplored. This study aims to investigate the relationship between HL, various types of HL, and CD, as well as the combined impact of HL and depression on CD.

METHODS

Data from a total of 5218 older adults who participated in the most recent three waves of Chinese Longitudinal Healthy Longevity Survey (CLHLS) (2011-2012, 2014, and 2018) were included. HL was assessed through self-report and objective measures. CD was defined as a decrease in MMSE score of≥3 between any two survey periods for older adults. Cox proportional hazards model was applied to analyzed.

RESULTS

Among Chinese older adults, bilateral HL (HR = 1.202, 95%CI = 1.093-1.322, P < 0.001), onset of HL after the age of 40 (HR = 1.155, 95%CI = 1.056-1.264, P = 0.002), and chronic HL (HR = 1.143, 95%CI = 1.040-1.255, P = 0.005) posed a greater risk. HL (HR = 1.146, 95%CI = 1.048-1.254, P = 0.003) and depression (HR = 1.162, 95%CI = 1.038-1.301, P = 0.009) were independently or jointly associated with CD. Participants who were simultaneously exposed to both HL and depression experienced the highest risk of CD (HR = 1.314, 95%CI = 1.117-1.545, P = 0.001).

LIMITATIONS

Given the observational design, unidentified confounding variables may still be present, such as whether to wear a hearing aid.

CONCLUSION

This study emphasizes the high risk of specific types of HL for CD and the importance of implementing health interventions that address both physiological and psychological aspects to enhance cognitive function and prevent CD in older adults.

Internet use, physical activity and depressive symptoms in older adults: A cross-lagged panel analysis

BACKGROUND

Existing cross-sectional studies suggest a strong positive association between Internet use, physical activity, and mental health in older adults; however, longitudinal studies reporting the relationship between Internet use, physical activity, and levels of depressive symptoms in older adults are lacking. This study aimed to examine the bidirectional relationship between Internet use and depressive symptoms in older adults and its underlying mechanisms.

METHODS

We used two waves of follow-up data (2016 and 2018) from the China Family Panel Studies, including 5837 participants aged 60 years or above. The bidirectional relationship between Internet usage time and depressive symptoms was examined using a cross-lagged model. The mediating role of physical exercise was examined using a half-longitudinal mediation model.

RESULTS

The results revealed a bidirectional relationship between Internet use time, frequency of physical activity, and depressive symptoms. Longer Internet use predicted lower levels of depressive symptoms, and the frequency of physical activity mediated the longitudinal relationship between Internet use and depressive symptoms in older adults.

LIMITATIONS

First, our study used self-report-based variables. Second, our study did not obtain the specific timing of the application of various functions of the Internet and the intensity of physical activity among older adults. Finally, based on the availability of data, our study involved only two waves of data. This may not be sufficient for a full longitudinal mediation effect test.

CONCLUSIONS

Internet use and depressive symptoms were interrelated over time among older adults. The frequency of physical activity was a mediator of Internet use and depressive symptoms. This underscores the importance of Internet-based technologies to enable healthy living and prevent depression and loneliness in older adults.

The effects of living arrangements and leisure activities on depressive symptoms of Chinese older adults: Evidence from panel data analysis

BACKGROUND

Livable environment and ways, as the necessary conditions for the elderly to enjoy their old age, have a significant impact on their mental health and happiness. It's crucial to understand how living arrangements affect depressive symptoms in China. Studies on how various leisure activities modify this association are yet limited.

METHODS

This study relies on panel data derived from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), collected during waves spanning 2008/2009, 2011/2012, 2014, and 2018. The primary objective is to examine the relationship between living arrangements, leisure activities, and depressive symptoms of elderly individuals. Linear mixed-effects models were used to analyze the data.

RESULTS

A total of 26,342 observations aged 65 and over were included in this paper. Older adults living alone (β = 0.66, 95 % CI: 0.55, 0.76) or living in institutions (β = 0.69, 95 % CI: 0.40, 0.98) had more depressive symptoms than those living with family. Leisure activities were negatively associated with depressive symptoms (β = -0.16, 95 % CI: -0.18, -0.15). Moreover, there was significant interactions between living arrangements and leisure activities. No matter which kind of living arrangements, participating in physical, productive or social activity was associated with a lower risk of depressive symptoms.

LIMITATIONS

Study design might introduce bias, and it cannot establish causality between the tested variables.

CONCLUSIONS

Older adults living alone or in institutions have more possibility to develop depressive symptoms than those living with family, and such a relationship among Chinese older adults can be moderated by participating in leisure activities.

Longitudinal associations between the frequency of playing Mahjong and cognitive functioning among older people in China: evidence from CLHLS, 2008-2018

Background

Cognitive decline is prevalent among older adults, often resulting in decreased capabilities for self-care and a diminished quality of life. Mahjong, a culturally cherished and extensively played intellectual game in China, demands considerable cognitive function. While the cognitive benefits of playing Mahjong have been widely accepted, this study investigates an under explored aspect and aimed to ascertain the game's potential contributions toward bolstering self-care abilities, enhancing overall quality of life, and mitigating against rising societal healthcare costs.

Methods

The data analyzed in the study is collected from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) with cognitive functioning being assessed through the Mini-Mental State Examination (MMSE). The frequency of playing Mahjong was measured through a self-reported questionnaire. Multiple linear regression models, latent variable growth models, and cross-lagged models were used to investigate the longitudinal relationship between game frequency and cognitive function in older people.

Results

Of the 7,535 participants, the mean (SD) age was 81.96 (10.53) years. There were 7,308 (97%), 4,453 (59%), and 1,974 (26%) participants in 2011, 2014, and 2018, respectively. The results showed that Mahjong players had significantly higher MMSE scores compared to non-players from 2008 to 2018 (β = 0.893; p < 0.001), and non-players had significantly lower scores in 2011, 2014, and 2018 than in 2008 (β = -1.326, -0.912, -0.833; Ps > 0.05). Moreover, the frequency of playing Mahjong was associated with improved various cognitive domains. The declining frequency of playing Mahjong was substantially associated with the declining rate of MMSE scores (r = 0.336; p < 0.001). Mahjong frequency showed positive effects on MMSE scores, while the influence of Mahjong on MMSE scores were not significant.

Conclusion

Playing Mahjong has a positive influence on the cognitive functioning among older people. It can help buffer against the decline in cognitive function and maintain cognitive function levels. The higher frequency of playing Mahjong is associated with improved reaction, attention and calculation, and self-coordination. A decline in the frequency of playing Mahjong was associated with a declining rate of cognitive function. The higher frequency of playing Mahjong among older people unilaterally influenced the improvement of cognitive function levels in older people in China.

Activities of daily living and non-exercise physical activity in older adults: findings from the Chinese Longitudinal Healthy Longevity Survey

OBJECTIVES

Studies have shown that good cognitive function can moderate the relationship between non-exercise physical activity (NEPA) and activities of daily living (ADLs) disability to some extent, and this study mainly explores the relationship between ADL and NEPA and cognitive function in Chinese older adults.

SETTING AND PARTICIPANTS

Data came from a nationally representative sample of 2471 Chinese old adults (aged 65+) from the 2011, 2014 and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey.

PRIMARY AND SECONDARY OUTCOME MEASURES

A cross-lagged panel model combined with mediation analysis was used to determine the relationship between ADL and NEPA and the mediating effect of cognitive function on the ascertained ADL-NEPA relationship.

RESULTS

The more frequently people over the age of 65 in China participate in NEPA, the lower the risk of ADL disability. Cognitive function partially mediated this expected relationship, accounting for 9.09% of the total NEPA effect on ADL.

CONCLUSION

Participating in more NEPA could reduce the risk of ADL disability, and participating in NEPA may reduce the risk of ADL disability through cognitive function to some extent.

Sequential link in depression, sleep and cognition: Longitudinal evidence from a serial multiple mediation analysis of older adults in China

BACKGROUND

A growing body of literature examines the link between depression, sleep and cognition, but little is known regarding the extent to which this relationship holds among older adults over time.

OBJECTIVE

This study examines how sleep duration mediates the relationship between depressive symptoms and cognitive performance, by utilizing partial least squares structural equation modelling (PLS-SEM) estimation.

METHODS

This study utilizes the 2013-18 China Health and Retirement Longitudinal Study (CHARLS) dataset, of which 3557 participants over the age of 50 satisfied inclusion criteria. Depressive symptoms and cognitive performance are measured by the Center for Epidemiological Studies Depression Scale (CESD) and the Mini-Mental State Examination (MMSE); sleep duration is assessed using the adapted Pittsburgh Sleep Quality Index (PSQI). A serial multiple mediation model was built to assess how depressive symptoms in 2013 and in 2018 are related, in addition to assessing their links with sleep duration and cognitive performance.

FINDINGS

Results indicate that early depression positively predicts depression progression (std.β = 0.564, 95 % Confidence Interval: 0.534, 0.594), but negatively predicts sleep duration (std.β = -0.081, 95 % CI: -0.128, -0.034) and cognitive performance (std.β = -0.118, 95 % CI: -0.165, -0.072). The sequential indirect effect of early depression operating via depression progression and sleep duration is evaluated to be -0.083 (95 % CI: -0.110, -0.056), representing as much as 41.29 % of the total effect.

CONCLUSIONS

Early depressive symptoms are directly associated with increased depressive symptoms and shortened sleep, which are identified as key channels through which early depression is linked with worsened cognition.

CLINICAL IMPLICATIONS

Many older adults may underestimate the adverse costs of early depression, since its net effects on cognition could be channeled indirectly and discretely via depression progression and sleep, which is worth highlighting in health guidelines and clinical recommendations.

Interaction between plant-based dietary pattern and frailty on cognitive decline: a longitudinal analysis of the Chinese Longitudinal Healthy Longevity Survey cohort

OBJECTIVES

Frailty is a risk factor for faster cognitive decline, while plant-based dietary patterns are associated with decreased risk of cognitive decline. We aimed to explore their interaction with cognitive function among older adults.

METHODS

We used data from the Chinese Longitudinal Healthy Longevity Survey between 2008 and 2018. Frailty was evaluated based on the frailty index (FI), and the plant-based diet index (PDI) was calculated using food frequency questionnaire at baseline. Repeated measures of the Mini-Mental State Examination (MMSE) were utilised to assess cognitive function. We used linear mixed models to estimate regression coefficients (β) and 95% confidence intervals (CI).

RESULTS

We included 7,166 participants with a median follow-up of 5.8 years. Participants in pre-frail (β = -0.18, 95% CI: -0.24, -0.13) and frail (β = -0.39, 95% CI: -0.48, -0.30) groups experienced an accelerated decline in MMSE score compared with the robust group. The PDI modified the above association, with corresponding associations with frailty being much more pronounced among participants with a lower PDI (frail vs. robust β = -0.44, 95% CI: -0.56, -0.32), compared with those with a higher PDI (frail vs. robust β = -0.27, 95% CI: -0.40, -0.13). In addition, A combination of frailty and a low PDI was strongly associated with a faster decline in MMSE score (β = -0.52, 95% CI: -0.63, -0.41).

CONCLUSION

Adherence to plant-based dietary patterns attenuates the association between frailty and cognitive decline. If the observed association is causal, promoting plant-based dietary patterns may be a strategy to reduce the effects of frailty on neurological health.

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 left temporal transverse cortex is affected by poor sleep quality, which in turn contributes to depressive symptoms in older adults

Sleep quality is critical for improving mental health among older adults. Despite this, there is a dearth of studies examining the correlation between sleep quality and emotional symptoms in the elderly population of China. This study included 496 community elders aged 55 years and older. The participants were divided into two groups based on their scores on the Pittsburgh Sleep Quality Index (PSQI), with 249 being classified as poor sleepers and 247 as good sleepers. All participants were asked to fill out a uniform survey which included details about their demographics, daily habits, and any illnesses they were dealing with. The Self-rating anxiety scale (SAS) and Geriatric Depression Scale (GDS) were employed to measure their levels of anxiety and depression, respectively. In addition, 50 healthy individuals also agreed to brain MR imaging. The finding of our study indicated that those with inadequate sleep had higher levels of depression and anxiety, and the overall anxiety and depression score was linked to the total PSQI score in a positive manner; The MRI subgroup analysis revealed that those with inadequate sleep quality had a greater thickness of the left transverse temporal gyrus (p < 0.05). In addition, a Linear regression analysis of the mediation model showed that poor sleep quality would result in higher scores on the GDS, and cortical thickness in the left transverse temporal gyrus played a fully mediated role in this process. Our research indicates that elderly people in community who have difficulty sleeping may be more likely to suffer from anxiety and depression, and this lack of sleep can result in depressive symptoms due to its impact on the thickness of the left transverse temporal cortex.

Loneliness and depression among community-dwelling older adults in China during the COVID-19 epidemic: The mediating role of social support

The psychological condition of community-dwelling older adults is a global concern under coronavirus disease 2019. Loneliness is the key risk factor for depression among community-dwelling older adults. This study aims to explore the role of social support as a mediating factor in the relationship between depression and loneliness among community-dwelling older adults. We conducted a cross-sectional study in Chenzhou, Hunan Province, China, from June to December 2021. The sample consisted of 570 community-dwelling adults aged over 60 years. Data were collected through a general information questionnaire, the Social Support Rating Scale, the University of California at Los Angeles Loneliness Scale, and the Center for Epidemiological Survey, Depression Scale. Statistical Package for the Social Sciences PROCESS macro was used to examine the mediating effect of social support between loneliness and depression. This study found that depression was negatively associated with social support (r = -0.381, P < .001), but it was positively correlated with loneliness (r = 0.403, P < .001); loneliness was a predictor of depression (B = 0.333, P < .001). In addition, social support significantly mediated the relationship between loneliness and depression, with an indirect effect of 0.239 (95% Bootstrap CI -0.264 to -0.510), the overall effect value for depression was 0.572, accounting for 56.3% of the total variance in depression within this model. In conclusion, the findings suggest that social support plays a mediating role between depression and loneliness in older adults. This implies that interventions aimed at reducing loneliness and enhancing social support have the potential to alleviate depressive symptoms among this population. By addressing these factors, healthcare professionals and caregivers can promote the mental well-being of older adults and contribute to improved overall quality of life.

Association between all-cause mortality and trajectories across quality and duration of sleep and cognitive function: based on Group-Based Multivariate Trajectory modeling

BACKGROUND

Sleep duration and quality are associated with cognition, but the interaction of the 3 indicators and their association with all-cause mortality is unclear.

METHODS

We used data from the Chinese Longitudinal Healthy Longevity Survey from 2005-2018 to identify latent trajectories of sleep duration, sleep quality, and cognitive function. Secondly, the multinomial logistic model was adopted to determine predictors of trajectory groups. Finally, the Cox regression model was used to examine the association between these trajectory groups and all-cause mortality.

RESULTS

A total of 5046 adults (49% women) with an average age of 76.34 were included in the study. The median follow-up period was 11.11 years, during which 1784 (35%) participants died. We identified 4 latent groups among older adults: 'Good-performance' (51%), 'Decreasing' (26%), 'Oversleep & cognitive impairment' (12%), and 'Sleep-deprived' (11%). Individuals in the 'Decreasing' had a 51% increased risk of all-cause mortality (HR = 1.51, 95% CI: 1.25 - 1.81, p < .001). Individuals in the 'Oversleep & cognitive impairment' had a 170% increased risk of all-cause mortality (HR = 2.7 95% CI: 2.13 - 3.43, p < .001). Women had a higher risk of all-cause mortality regardless of trajectory group (47-143% men VS. 74-365% women). Both urban and rural areas have a similarly increased risk of all-cause mortality (48-179%).

CONCLUSIONS

Our study reveals the latent trajectories across sleep duration, sleep quality, and cognitive function in older Chinese and further explores their association with death. These findings provide a rational basis for cognitive interventions and reduce all-cause mortality.

A bibliometric analysis of sleep in older adults

Background

Sleep problems severely affect the quality of life in the elderly and have gradually gained attention among scholars. As a major hot spot of current research, sleep in older adults is highly exploratory and of great significance for human health.

Objective

Therefore, in this study, the current state of the art of sleep research in older adults was analyzed through the visual mapping function of CiteSpace software. Using this software, we analyzed popular research questions and directions and revealed the development trends and research frontiers of this field.

Methods

In this paper, we searched the Web of Science database for sleep-related studies focusing on older adults and analyzed the number of publications, journals, authors, institutions, country regions, and keywords by using CiteSpace software.

Results

Our results revealed that the number of publications concerning sleep in older adults has gradually increased; after 2017, this field underwent rapid development. The journal Sleep has published the majority of the articles on sleep in older adults and has the highest citation frequency. The Journal of the American Geriatrics Society has the highest impact factor and CiteScore among the top 10 journals in terms of the number of published articles. The United States has the highest number of publications and most of the leading institutions in this field are located in the United States, with the University of California, Los Angeles, and the University of Pittsburgh having the highest number of publications. Dzierzewski JM is the most published author and has played an important role in guiding the development of this field. Research in this area is focused on insomnia, sleep quality, depression, and sleep duration.

Conclusion

The rapid development of sleep research in older adults, which shows a yearly growth trend, indicates that this field is receiving increasing attention from researchers. Insomnia in older adults is the most concerning problem in this field. At the same time, future research should continue to focus on the impact of sleep disorders on older adults to improve sleep and quality of life in older adults.

Living alone reduces the decline of calf circumference among Chinese older adults: A 4-year longitudinal study

Background: Calf circumference (CC) is regarded as a surrogate marker of skeletal muscle mass with high sensitivity and specificity for predicting sarcopenia. A cross-sectional study reported older adults living alone were at high risk of developing sarcopenia. Whether living alone affects the change of calf circumference is unknown and there is no evidence from longitudinal study. The purpose of this study was to investigate the relationship between living arrangements and the change of calf circumferences among older adults in China. Methods: The data were from the Chinese Longitudinal Healthy Longevity Survey. A total of 2,203 older adults (age ≥65 years, mean age: 80.61 ± 8.30 years, 50.0% female) who were interviewed in 2014 and then 2018 follow-up survey were finally included for analysis. Living arrangements and other information were collected in 2014. Calf circumferences were measured and recorded in the questionnaires of two waves and the differences were calculated. Logistic regression analyses were conducted to evaluate the association of living arrangements (living alone or not living alone) with the change of calf circumferences (decline or no decline). Results: There were 446 (20.2%) participants living alone and 1,757 (79.8%) participants not living alone. After about 4 years, calf circumferences of 866 (39.3%) older adults declined. Compared to not living alone, living alone was negatively associated with calf circumference decline, even after adjustment for covariates (OR: 0.702, 95% CI: 0.547-0.901, p = 0.005). This significant association was found in 65-79 years old (OR: 0.619, 95% CI: 0.407-0.942, p = 0.025), female (OR: 0.567, 95% CI: 0.408-0.790, p = 0.001) and city/town (OR: 0.461, 95% CI: 0.310-0.685, p < 0.001) subgroups but not in advanced age (≥80 years old), male and rural subgroups. Conclusion: This study revealed that living alone was associated with a decreased risk of calf circumference decline among older adults, and might be a protective factor for sarcopenia.

The Effect of Depressive and Insomnia Symptoms in Quality of Life among Community-Dwelling Older Adults

The purpose of this study was to investigate the effects of depressive symptoms, insomnia symptoms, and comorbid depressive and insomnia symptoms on the quality of life among community-dwelling older adults in an urban area of central Greece. A cross-sectional study was conducted on 200 older adults (aged ≥ 60) collected from five Open Care Centers for Elderly People of the Municipality of Larissa, Greece. Data were obtained through a questionnaire that included demographic, socioeconomic, and health-related characteristics; the World Health Organization Quality of Life (WHOQoL)-Bref questionnaire; the Geriatric Depression Scale; and the Athens Insomnia Scale. The prevalences of depression, insomnia, and comorbid depression and insomnia were 28% (95% confidence interval (95% CI): 21.8-34.2%), 40.5% (95% CI: 33.7-47.3%), and 19% (95% CI: 13.5-24.5%), respectively. The mean WHOQoL-Bref score for all domains was approximately 14.50, with the highest mean value observed for psychological health (14.79 ± 2.60), followed by the physical health (14.49 ± 2.66), social relationships (14.39 ± 2.03), and environmental domains (14.32 ± 1.90). All WHOQoL-Bref domains were negatively correlated with depression and insomnia. Older adults with depressive symptoms, insomnia symptoms, and comorbid depressive and insomnia symptoms had lower scores in all quality of life dimensions compared with those without.

Longitudinal Relationship between Cognitive Function and Health-Related Quality of Life among Middle-Aged and Older Patients with Diabetes in China: Digital Usage Behavior Differences

BACKGROUND

Cognitive function and health-related quality of life (HRQoL) are important issues in diabetes care. According to the China Association for Aging, it is estimated that by 2030, the number of elderly people with dementia in China will reach 22 million. The World Health Organization reports that by 2044, the number of people with diabetes in China is expected to reach 175 million.

METHODS

Cohort analyses were conducted based on 854 diabetic patients aged ≥45 years from the third (2015) and fourth (2018) survey of the China Health and Retirement Longitudinal Study (CHARLS). Correlation analysis, repeated-measures variance analysis, and cross-lagged panel models were used to measure the difference in digital usage behavior in the established relationship.

RESULTS

The results show that the cognitive function of middle-aged and older diabetic patients is positively correlated with HRQoL. HRQoL at T1 could significantly predict cognitive function at T2 (PCS: B = 0.12, p < 0.01; MCS: B = 0.14, p < 0.01). This relationship is more associated with individual performance than digital usage behavior.

CONCLUSIONS

Unidirectional associations may exist between cognitive function and HRQoL among middle-aged and older Chinese diabetes patients. In the future, doctors and nurses can recognize the lowering of self-perceived HRQoL of middle-aged and older diabetic patients, and thus draw more attention to their cognitive function, in turn strengthening the evaluation, detection, and intervention of their cognitive function.

The major risk factor for depression in the Chinese middle-aged and elderly population: A cross-sectional study

BACKGROUND

The number of patients suffering from depression is continuously increasing in China. Demographic characteristics, physical health levels, and individual lifestyles/healthy behaviors are associated with the severity of depression. However, the major risk factor for depression remains unclear.

MATERIALS AND METHODS

In this investigation, 16,512 patients were screened using the CHARLS (China Health and Retirement Longitudinal Study) database after being determined to be eligible based on the inclusion criteria. Depressive symptoms were evaluated through the CESD-10 (10-item Center for Epidemiological Studies Depression Scale). Consequently, various models were developed based on potential predictive factors, employing stepwise LR (Logistic Regression)/RF (Random Forests) models to examine the influence and weighting of candidate factors that affect depression.

RESULTS

Gender, residential address location, changes in health status following last interview, physical disabilities, chronic pain, childhood health status, ADL (activity of daily living), and social activity were all revealed to be independent risk factors for depression (p < 0.05) in this study. Depression has a synergic effect (across chronic pain and age groups). In comparison to other factors, RF results showed that chronic pain had a stronger impact on depression.

CONCLUSION

This preliminary study reveals that chronic pain is a major risk factor for depression.