Productive activities and cognitive decline among older adults in China: Evidence from the China Health and Retirement Longitudinal Study

Cognition as mediator of pulmonary function and risk of sarcopenia among older adults

BACKGROUND

The relationship between lung function and sarcopenia remains ambiguous. The primary aim of this study was to investigate the potential association between lung function and sarcopenia in the older adults, as well as to examine the mediating role of cognitive function in this relationship.

METHODS

The participants were selected from a nationally representative population-based cohort in China. The peak expiratory flow (PEF) measurement was used to evaluate the lung function in older persons. The sarcopenia was diagnosed using the guidelines of the Asian Working Group for Sarcopenia (AWGS) in 2019. The Cox proportional hazard model was utilized to perform primary analyses of the relationship between PEF and sarcopenia. The mediating effect of cognitive function was evaluated using the counterfactual mediation method.

RESULTS

This cohort study included 4,011 older adults (average age, 66.6 years; 53.3% males). During a follow-up period of 3.86 years, 349 individuals were diagnosed with sarcopenia. After adjusting for potential confounders, each one-standard-deviation increase in PEF was associated with a 28% reduction in the risk of sarcopenia (hazard ratio [HR]: 0.72; 95% confidence interval [CI]: 0.63, 0.80). There was a significant mediation of cognition for the association between PEF and incident sarcopenia, and the proportion mediated was 12.2% (95% CI: 4.5%, 23.1%).

CONCLUSIONS

Older adults with impaired lung function are more likely to develop sarcopenia. Nevertheless, cognition can explain only a small portion of this association. Thus, other potential pathways between lung function and sarcopenia must be elucidated.

Intergenerational Caregiving Patterns and Cognitive Health among the Sandwich Generation Within Four-Generation Families

This study aims to investigate whether generational differences in intergenerational caregiving patterns (caring for parents only, caring for grandchildren only, and caring for parents and grandchildren simultaneously) are associated with cognitive health disparities among the sandwich generation within four-generation families, drawing upon the theories of intergenerational solidarity and intergenerational stake. Moreover, this study seeks to identify mediators that help explain these disparities. A nationally representative sample of 8,065 respondents was drawn from the 2011 and 2018 waves of the China Health and Retirement Longitudinal Study. The findings reveal that the sandwich generation caring for grandchildren only, as well as those caring for grandchildren and parents simultaneously, exhibit better cognitive health. However, caregiving for parents only is not significantly related to their cognitive health. This study identifies the inability to reduce depressive symptoms as a mediator explaining the insignificant association between caregiving for parents only and the cognitive health of the sandwich generation. The findings underscore the importance of offering support to the sandwich generation within four-generation families to enhance their cognitive health. Moreover, it is imperative to distinguish between different intergenerational caregiving patterns based on generational differences among the sandwich generation, with a specific emphasis on allocating public resources aimed at promoting cognitive health for those engaged in caring for parents.

Nonlinear association between self-reported sleep duration and cognitive function among middle-aged and older adults in China: The moderating effect of informal care

BACKGROUND

Cognitive impairment is a major public health problem urgently to be solved. This study aims to examine the association between sleep duration and cognitive function and its two subdimensions: episodic memory and mental status, and to explore the moderating effects of informal care on these associations among middle-aged and older adults in China.

METHODS

Data was drawn from China Health and Retirement Longitudinal Study (CHARLS) 2011, 2013, 2015 and 2018 datasets. Sleep duration and informal care were self-reported. Cognitive function was measured using CHARLS Harmonized Cognitive Assessment Protocol. Effects of informal care on sleep duration-cognitive function were assessed using Generalized Estimating Equations models.

RESULTS

The relationships between sleep duration and cognitive function, episodic memory, and mental status were all found to follow an inverted U-shaped pattern. Spouse care weakened the adverse effects of extreme sleep duration on cognitive function while the children care amplified them. Further, we only observed the moderating effects of spouse and children care on the association between sleep duration and episodic memory, but not mental status.

CONCLUSIONS

The relationships between sleep duration and cognitive function, along with its different dimensions, are nonlinear in nature. The impacts of sleep duration on cognitive function and its dimensions are contingent upon the levels of informal care received and the sources of that care. We provide valuable insights into the complex interplay between sleep duration, informal care, and cognitive function.

Does internet use benefit the mental health of older adults? Empirical evidence from the China health and retirement longitudinal study

The mental health (MH) of older adults is a prominent public health concern. However, research regarding the impact of emerging Internet use on MH among older adults remains limited, particularly in transitional economies experiencing a rapidly aging population such as China. Thus, to address this research gap, this study uses data from the 2013-2018 waves of the China Health and Retirement Longitudinal Study. To investigate the causal relationship between Internet use and MH among older adults and explore the underlying channels through which this relationship operates. The results reveal a notable positive association between Internet use and MH among older adults. Furthermore, the study highlights social interaction, social trust, traveling expenses, and healthy habits as crucial channels through which Internet use can impact MH among older adults. The analysis also reveals how Internet use demonstrates a stronger positive effect on older individuals who have fewer chronic diseases and live with their offspring compared with their counterparts. These findings have significant policy implications, which thus emphasizes the need to enhance Internet use among older adults as a means of improving their MH.

Association between obesity, physical activity, and cognitive decline in Chinese middle and old-aged adults: a mediation analysis

BACKGROUND AND OBJECTIVES

Epidemiological evidence on obesity and cognitive decline in middle and old-aged individuals is controversial and the effect of physical activity in this chain is sparse and limited. This study aimed to characterize the association between obesity and cognitive decline and the mediating role of physical activity.

METHODS

Data from China Health and Retirement Longitudinal Study (CHARLS) were used, including 7,392 participants aged ≥ 45 years between 2011 and 2018. Cognitive function was assessed via episodic memory and mental status. The total score of cognitive function was the sum of the above two dimensions (0-31 points). The Group-based trajectory modeling (GBTM) was applied to identify the potential heterogeneity of longitudinal changes in cognitive function. Multivariable ordinal logistic regression was used to investigate associations between obesity and cognitive trajectories, taking body mass index (BMI) as the indicator of obesity. Mediation analysis was performed to examine the potential causal chain in which physical activity mediates the relationship between BMI and cognitive decline.

RESULTS

Of the 7,392 analyzed patients (mean [SD] age, 58.0 [8.5] years; 3,916 [53%] male), the median (interquartile range [IQR]) of BMI was 23.4 (21.1-26.0). Four trajectories were identified by the GBTM model, including the high stable (14.9%), the middle stable (46.0%), the middle decline (29.9%), and the low decline groups (9.2%). After controlling potential confounders, obesity was associated with the low decline groups compared with normal weight (adjusted OR 0.81; 95% CI, 0.70-0.94). Mediation analyses showed that only vigorous physical activity significantly explained 5.94% (95% CI, 0.29-11.60%) of the relationship between obesity and cognitive decline. Sensitivity analyses in different subgroups showed comparable results.

CONCLUSION

This study suggests that vigorous physical activity mediates less than 10% of the association between obesity and cognitive decline in middle and old-aged adults. Further studies are warranted to explore the potential factors related to the obesity paradox in the cognitive field.

Efficacy of sensory-based static balance training on the balance ability, aging attitude, and perceived stress of older adults in the community: a randomized controlled trial

BACKGROUND

This study explores the effect of sensory-based static balance training on the balance ability, aging attitude, and perceived stress of older adults in the community. It provides a practical basis for the in-depth implementation and revision of the community health management model.

METHODS

A randomized controlled intervention study was conducted from 2022 to 2023. A total of 72 older adults were recruited and randomly divided into an intervention group (36 individuals) and a control group (36 individuals). Balance ability (measured by the Short Physical Performance Battery and One Leg Stand Test), aging attitudes, and perceived stress were assessed at baseline and at the 12-week and 24-week follow-ups. Repeated-measures ANOVA and generalized estimating equations were used to compare outcome measures.

RESULTS

Sensory-based static balance training was beneficial for balance ability and aging attitude among participants in the intervention group. At the end of the intervention, participants in the intervention group showed significant improvements in SPPB scores and OLST scores compared with the control group (FSPPB = 12.347, P = 0.001, Waldχ2OLST = 45.530, P < 0.001), as well as significant differences in aging attitudes (FAAQ = 18.549, P < 0.001). Multiple comparisons at different time points in the intervention group reveal a significant intervention effect (FSPPB = 29.211, Waldχ2OLST = 80.428, FAAQ = 45.981, all P < 0.05). However, the difference in perceived stress before and after the intervention was not significant (FCPSS = 2.876, P = 0.095).

CONCLUSIONS

Sensory-based static balance training significantly improved balance ability and aging attitudes among older adults in the community. The effect on perceived stress among older adults in the community was not significant.

TRIAL REGISTRATION

Registered in the Chinese Clinic on 04/06/2022. The registration number is ChiCTR2200060541.

Association of social integration with cognitive function trajectories among Chinese older adults: evidence from the China health and retirement longitudinal study (CHARLS)

Background

The prevalence of cognitive impairment among older adults remains high. It has been proven that social integration is related to cognitive function. However, limited research has examined the association of social integration and its different dimensions with cognitive function trajectories of older adults.

Methods

The data were from the China Health and Retirement Longitudinal Study (CHARLS) spanning 2013 (T1) to 2018 (T3). A total of 3,977 older adults were included in the final analysis. Cognitive function was measured with items from an adapted Chinese version of the Mini-Mini-Mental Mental State Examination (MMSE), while the measurement of social integration included three dimensions: economic integration, relational integration and community integration. A group-based trajectory model (GBTM) was used to identify cognitive trajectory groups among participants and an unordered multinomial logistic regression was employed to explore the association of baseline social integration and its three dimensions with cognitive function trajectories.

Result

Three cognitive function trajectory groups were identified: low-decline group (24.1%), medium-decline group (44.2%) and high-stable group (31.7%). Comparing to the medium-decline trajectory group, older adults with higher social integration scores were more likely to be in the high-stable trajectory group (OR = 1.087, 95%CI: 1.007 ~ 1.174), while less likely to be in the low-decline group (OR = 0.806, 95%CI: 0.736 ~ 0.882). Among the different dimensions of social integration, older adults with higher community integration scores were more likely to be in the high-stable trajectory group (OR = 1.222, 95%CI: 1.026 ~ 1.456); Older adults with higher relational integration scores were less likely to be in the low-decline trajectory group (OR = 0.816, 95%CI: 0.734 ~ 0.906). The economic integration was not found to correlate with the cognitive function trajectories. Stratified analyses revealed that the association between community integration and cognitive trajectories was only significant among older adults aged 60 to 69, and the association between relational integration and cognitive trajectories was only significant among older adults who was agricultural household registration.

Conclusion

The developmental trajectories of cognitive function among Chinese older adults are heterogeneous. Social integration is significantly related to the trajectories of cognitive function in Chinese older adults. Measures should be taken to promote social integration of Chinese older adults to reduce the decline of cognitive function.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Age-friendly neighbourhood environment, functional abilities and life satisfaction: A longitudinal analysis of older adults in urban China

The construction of age-friendly neighbourhoods is a priority for practice and policy to promote active ageing and increase life satisfaction for older adults. However, there has been a paucity of longitudinal evidence on the interaction effects of age-friendly neighbourhood environment and functional abilities on life satisfaction among older adults in urban China. This study makes the first attempt to examine the effect of person-environment fit on life satisfaction by the accumulative effects of age-friendliness of the baseline neighbourhood environment (measured within the WHO Age-Friendly City framework) on functional abilities and life satisfaction trajectories and the long-term effects of functioning changes on life satisfaction, drawing from four waves of longitudinal data from the China Health and Retirement Longitudinal Study (CHARLS) and latent growth curve modelling. Results indicated that the age-friendliness of transportation was positively associated with functional abilities, and housing was the primary factor that shaped life satisfaction at the baseline. Better maintenance of functional abilities could promote life satisfaction over time. For older adults living in recently built neighbourhoods, social environment factors such as associations and facilities for social participation were more important in functional abilities, and communication and information were more important in life satisfaction. For those living in neighbourhoods built before 2000, physical environment factors such as transportation were essential in functional abilities, and housing was more essential in life satisfaction; health-related facilities and services at baseline exerted a cumulative effect on maintaining functional abilities in the long run. Our findings inform policymakers about how to effectively allocate public resources to enhance older adults' life satisfaction in the Chinese urban context.

Physical Mobility, Social Isolation and Cognitive Function: Are There Really Gender Differences?

OBJECTIVE

This study aimed to examine the mediating role of social isolation between physical mobility and cognitive function, and whether there are gender differences in the above mediating effects among Chinese older adults.

METHODS

This is a prospective and cohort study. We obtained data from the 2011 (Time 1, T1), 2015 (Time 2, T2) and 2018 (Time 3, T3) waves of China Health and Retirement Longitudinal Study, including 3,395 participants aged 60 years or above. Cognition was evaluated by Telephone Interview of Cognitive Status, words recall, and figure drawing, which was widely used in previous research. We used a cross-lagged model to test the hypothesis that social isolation mediated the association between physical mobility and cognitive function among Chinese older adults.

RESULTS

The total effects of T1 physical mobility limitations on T3 cognitive function (β = -0.055, bootstrap p < 0.001) were significantly negative. Social isolation played a mediating role among both males and females (male: β = -0.008, bootstrap p = 0.012; female: β = -0.006, bootstrap p = 0.023), demonstrating that the mediating effect of social isolation between physical mobility and cognitive function was not gender specific.

CONCLUSION

This study confirmed that social isolation mediated the association between physical mobility and cognitive function among both Chinese male and female older adults. These findings indicate that reversing social isolation can be a priority intervention target for cognitive decline prevention and promote successful ageing, particularly among older adults with impaired physical mobility.

The impact of sensory impairments and eye diseases on cognitive function in elderly Chinese: The mediating effects of social participation

Background

Sensory impairments and eye diseases increase the risk of cognitive decline, but little is known regarding their influence on cognitive function in elderly Chinese and the underlying mechanisms. We aimed to explore these influence mechanism from the social participation perspective.

Methods

We selected 2876 respondents aged ≥60 from the China Health and Retirement Longitudinal Study (CHARLS) conducted in 2013, 2015, and 2018. We assessed sensory impairments and eye diseases based on self-reported responses, and evaluated its relation to social participation and cognitive function by fixed-effects regression and mediation effect analysis over a five-year period.

Results

Respondents with visual impairment and cataracts had poor memory and mental status. Compared with near visual impairment, distance visual impairment was associated with a 1.7 times higher likelihood of cognitive decline (correlation coefficient (β) = -0.051; 95% confidence interval (CI) = -0.065, -0.036)). Respondents with hearing impairment had bad memory (β = -0.046; 95% CI = -0.065, -0.036), but not mental status. Social participation partially mediated the relationships of sensory impairments and cataracts with cognitive function in elderly Chinese. Individuals with sensory impairments affected by limited social participation reported a faster cognitive decline compared to those with eye disease.

Conclusions

We found that sensory impairments and eye diseases were negatively associated with cognitive function. Furthermore, sensory impairments and cataracts influence cognitive function partly via social participation. Our results have important theoretical and practical implications and suggests that early interventions for sensory impairments and eye diseases may improve the cognitive function of elderly people.

Relationship between left-behind status and cognitive function in older Chinese adults: a prospective 3-year cohort study

Background

Due to the inaccuracy of the traditional geographical distance-based definition of left-behind status, data on the negative effect of left-behind status on cognitive function among older adults are controversial.

Aims

This study examined the cross-sectional and longitudinal associations of left-behind status with cognitive function in older Chinese adults. The left-behind status definition was based on the frequency of face-to-face parent-child meetings.

Methods

Data from a nationally representative sample of 8 682 older adults (60+ years) in 2015 (5 658 left behind and 3 024 non-left behind), of which 6 933 completed the follow-up in 2018, were obtained from the China Health and Retirement Longitudinal Study. Left-behind older adults were broadly defined as those aged 60+ years who had living adult children and saw their children less than once per month. The cognitive function was assessed with a composite cognitive test with higher total scores indicating better cognitive function.

Results

Left-behind older adults had significantly lower cognitive test scores than non-left-behind older adults in both 2015 (11.1 (6.0) vs 13.2 (5.9), t=15.863, p<0.001) and 2018 (10.0 (6.6) vs 12.4 (6.7), t=14.177, p<0.001). After adjusting for demographic factors, lifestyle factors, chronic medical conditions and the baseline cognitive test score (in the longitudinal analysis only), on average, the cognitive test score of left-behind older adults was 0.628 lower than their non-left-behind counterparts in 2015 (t=5.689, p<0.001). This difference in cognitive test scores attenuated to 0.322 but remained significant in 2018 (t=2.733, p=0.006).

Conclusions

Left-behind older Chinese adults have a higher risk of poor cognitive function and cognitive decline than their non-left-behind counterparts. Specific efforts targeting left-behind older adults, such as encouraging adult children to visit their parents more regularly, are warranted to maintain or delay the progression of cognitive decline.

Can afternoon napping protect against the negative effect of short or long sleep duration on cognitive function? A prospective study

OBJECTIVES

Afternoon napping has been found to be able to compensate for the negative health effects of less optimal nighttime sleep duration. Our study aimed to investigate whether napping can protect against the negative effects of short or long sleep duration on cognitive function among middle-aged and older adults.

METHODS

A total of 8107 participants (men, 53.19%) aged 45 and older from the China Health and Retirement Longitudinal Study were followed prospectively for 7 years. The primary outcome was cognitive function (episodic memory and mental status). Afternoon napping was categorized into three groups including non- (0 min), moderate (1-30 min) and long (>30 min) duration. Nighttime sleep was also categorized into three groups including short (<7 h), normal (7-8 h), and long (>8 h) duration. Linear mixed models were used with napping and sleep duration at baseline as predictors. Potential confounders including baseline cognitive function were adjusted.

RESULTS

Shorter sleep duration (B = -0.01, p = 0.048) was independently associated with a faster decline in episodic memory. For participants with shorter sleep duration, either non-napping (B = -0.03, p = 0.017) or longer napping (B = -0.04, p = 0.018) showed a significant decline of episodic memory. For participants with longer sleep duration, non-napping was associated with a significant decline of episodic memory (B = -0.07, p = 0.003).

CONCLUSIONS

This study found that moderate napping could protect against the negative effects of short or long sleep duration on episodic memory, which implied that middle-aged and older adults who have a less optimal sleep duration might benefit from moderate napping for their cognitive function.

Leisure Participation and Cognitive Impairment Among Healthy Older Adults in China

Leisure participation is beneficial to various health outcomes. This study examined a comprehensive list of leisure activities in relation to incidence of cognitive impairment among healthy older adults (65+) in China. Using data from the 2002 to 2018 Chinese Longitudinal Healthy Longevity Survey, we found that most of the leisure activities were protective of cognitive decline and three leisure activities (watching TV, doing housework, and playing cards/mah-jong) stood out as the most important ones. Additionally, our results revealed subgroup variations in the association between leisure participation and cognitive function: Leisure activities such as reading newspapers/books (not significant for the illiterate), gardening (not significant for the illiterate), and regular exercise (not significant for the rural residents) had different effects across different demographic social groups. Our findings suggest that intervention programs designed to prevent cognitive decline for older adults should consider subgroup and cultural variations in order to yield the best outcomes.

Association Between Paid Work and Health-Related Quality of Life Among Community-Dwelling Older Adults: The Sukagawa Study

In this study, we aimed to determine whether paid work has an impact on health-related quality of life (HRQOL) among older adults. Over three years, we longitudinally collected data from 5,260 community-dwelling older adults aged 75 years or older from a city in Japan. We assessed HRQOL using the Short-Form-8. We estimated the mean difference between the physical component summary (PCS) and the mental component summary (MCS) scores, which were stratified based on gender using multivariate, generalized estimating equation models. We further conducted a subgroup analysis based on the participants' occupational backgrounds. Engagement in paid work was associated with increased MCS scores across both genders and with increased PCS scores among women. In the subgroup analysis, only women who had previously worked as managerial workers showed an inverse association with MCS scores. In this population, engagement in paid work may be a crucial factor associated with well-being.

The relationship between physical activity, physical health, and mental health among older Chinese adults: A scoping review

The aging Chinese population is growing fast, and the proportion of the population aged 60 years old is projected to reach 28% by 2040, estimated 402 million. With increased life expectancy, the aging population tends to suffer from health risks and diseases, which create a burden on public health policy. Hence, it is essential to promote healthy and active aging, which includes improving older adults' physical and mental capacities and advocating for the achievement of a healthy life expectancy. Despite the rapidly growing aging population in China, there have been no reviews investigating the effect of physical activity on physical and mental health among older Chinese adults. Therefore, the current study aimed to review studies from the past 15 years that illustrate the effect of physical activity on physical and mental health among Chinese older adults. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews (PRISMA-ScR), this review addresses the associations between physical activity, physical health and mental health among older Chinese adults. A total of 371 studies were included in the scoping review, which covered the relationships between physical activity, physical health and mental health variables. The scoping review also revealed the impact of various kinds of physical activity affecting older adults' physical health, such as functional fitness, body composition, fall risk and balance, and mental health issues, such as depression, anxiety, cognitive function and quality of life. Moreover, studies have identified innovative forms of physical activity as emerging trends in physical activity interventions for older adults. To conclude, this scoping review captured the common effects between physical activity and overall wellbeing, including physical, mental, and cognitive health. Additionally, diverse forms of physical activity intervention, such as group-based and supervised individual interventions, should be supported, and cross-cultural exercise comparisons should be made in future explorations.

Informal sector employment and the health outcomes of older workers in India

A large proportion of the older population in India constitutes an undeniable share of workforce after the retirement age. This stresses the need to understand the implications of working at older ages on health outcomes. The main objective of this study is to examine the variations in health outcomes by formal/informal sector of employment of older workers using the first wave of the Longitudinal Ageing Study in India. Using binary logistic regression models, the results of this study affirm that type of work does play a significant role in determining health outcomes even after controlling socio-economic, demographic, life-style behaviour, childhood health and work characteristics. The risk of Poor Cognitive Functioning (PCF) is high among informal workers, while formal workers suffer greatly from Chronic Health Conditions (CHC) and Functional Limitations (FL). Moreover, the risk of PCF and/or FL among formal workers increases with the increase in risk of CHC. Therefore, the present research study underscores the relevance of policies focusing on providing health and healthcare benefits by respective economic activity and socio-economic position of older workers.

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

Introduction

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

Methods

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

Results

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

Discussion

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

Grandparenting and subjective well-being in China: The moderating effects of residential location, gender, age, and income

Grandparenting is a social determinant of older adults' subjective well-being (SWB) worldwide, and is receiving increasing scholarly attention. Grandparenting is particularly prevalent in China because of the increasing number of women in the labor force, shortages of daycare services, and intergenerational bonds. Based on three waves (2011, 2013, and 2015) of the China Health and Retirement Longitudinal Study (n = 14,846), we used pooled ordinary least squares (POLS) regression to examine the association between grandparenting and Chinese older adults' SWB and the moderating effects of residential location (rural/urban), gender, age, and income. We measured SWB by four outcomes: self-rated health, life satisfaction, depressive symptoms, and cognitive function. Our findings indicate that intensive grandparenting is positively associated with older adults' life satisfaction. Older adults providing a low-to-high intensity of grandparenting have better cognitive function than non-caregivers. Among caregivers, a moderate level of grandparenting is associated with better cognitive function. Residential location, age, and income are significant moderators. For example, high-intensity grandparenting is positively associated with rural grandparents' but not urban grandparents' life satisfaction. Although younger grandparents have better self-rated health, higher life satisfaction, and fewer depressive symptoms than their older counterparts if they provide grandparenting care, grandparenting is more beneficial for older grandparents' cognitive function. Both low and high intensities of grandparenting are positively related to self-rated health and cognitive function for grandparents with lower incomes. Overall, the findings of this study indicate how grandparenting is related to the SWB of older people in China in different social groups and of people living in different locations.

How does neighbourhood environment influence loneliness in later life in Urban China? The role of financial status

This study aimed to examine whether older adults' financial status moderated the association between neighbourhood environment (i.e. physical and social environment) and loneliness among older adults in urban China. A cross-sectional survey was collected from urban communities of Shanghai in mid-2020. The final analytic sample was 459 older adults (age range = 60-91 years; proportion of women: 55.8%). Multiple group analysis was applied to test the hypothesised model. A measurement model of community social capital (i.e. cognitive and structural dimensions of social capital), a crucial indicator of neighbourhood social environment, was first established in both high-income and low-income groups. Factor loading invariance was established in these two groups. The results show that structural social capital (i.e. organisation memberships, volunteering, social participation and citizenship activities) was negatively associated with loneliness among older respondents from the high-income group only, whereas better community security was significantly associated with lower levels of loneliness among low-income older respondents only. The findings imply that both structural social capital and household income should be considered as important indicators in needs assessment among lonely older adults. Future social policies and interventions should pay attention to enhancing the role of both social and physical neighbourhood environment among older adults.

Associations between volunteering and cognitive impairment: The moderating role of race/ethnicity

Although volunteering has been shown to benefit cognitive health, there is a paucity of evidence on informal volunteering and subjective measures of cognitive impairment. Also, little is known about whether such relationships vary by race/ethnicity. This study aimed to examine the associations of both formal and informal volunteering with older adults' objective and subjective cognition and explore the moderating role of race/ethnicity in such associations. Using data from the Health and Retirement Study in the United States (2010-2016), 9941 older adults (51+) who were cognitively unimpaired in 2010 and alive through 2016 were included. Ordered logistic regression models were performed to assess the relationships among volunteering, cognitive impairment and race/ethnicity. Findings showed that more years of formal and informal volunteering significantly reduced the odds of objective cognitive impairment; neither volunteering type was significant for subjective cognitive impairment. The relationship between informal volunteering and objective cognition varied by race/ethnicity. Compared to non-Hispanic Whites, non-Hispanic Black older adults who engaged in more years of informal volunteering had a significantly higher odds of cognitive impairment over time. The current study is one of the first to look at the associations between informal volunteering and cognition. The inclusion of subjective cognitive impairment, paired with objective measures of cognition, also adds value to the knowledge body. Our findings indicate any type of volunteering is a viable approach to prevent cognitive impairment for older populations. However, more research is needed to better understand why racial/ethnic minority, particularly non-Hispanic Black older adults, do not benefit from informal volunteering.

Mild Cognitive Impairment in Rural Areas: Research Advances and Implications for Clinical Practice and Healthcare Policy

Mild cognitive or neurocognitive impairment (MCI) may be more prevalent in rural areas. Differences between rural and urban MCI patients in terms of risk factors, course and prognosis are rarely reported. The present review aims to summarize the latest research on MCI in rural areas. A literature search was performed in the databases of PubMed, Scopus and ScienceDirect for articles published over the last decade. Eleven articles were included in this review, reporting on the differences between rural and urban MCI patients. Several risk factors, such as older age, lack of activities and food insecurity have been associated with MCI in both rural and urban areas, whereas others, such as obesity, adverse childhood experiences and plasma chemokine C-C motif ligand 11 (considered as a potential negative regulator of neurogenesis), differed according to the place of residence. No specific protective factor for rural women has been reported. There is some evidence that MCI may present earlier in rural residents, but that progression to dementia may be more rapid in urban residents. It seems that there may be clinically relevant differences in the onset, course and prognosis of MCI with regards to the place of residence (urban vs rural). Those differences should be taken into account for the design of health policies and service delivery across different settings.

Association between cognitive function and ambient particulate matters in middle-aged and elderly Chinese adults: Evidence from the China Health and Retirement Longitudinal Study (CHARLS)

Increasing studies have discussed how ambient air pollution affects cognitive function, however, the results are inconsistent, and such studies are limited in developing countries. To fill the gap, in this study, we aimed to explore the effect of ambient particulate matters (PM₁, PM_2.5, PM₁₀) on cognitive function of middle-aged and elderly Chinese adults. A total of 7928 participants older than 45 were included from CHARLS collected in 2011, 2013, and 2015. Cognitive function was evaluated with two dimensions, the first one was episodic memory and the second dimension was mental status. The total score of cognitive function was the sum of above two dimensions (0-31 points). Participants' exposure to ambient particulate matters was estimated by using a satellite-based spatiotemporal model. Linear mixed models were applied to analyze the impact of PM₁, PM_2.5, and PM₁₀ on cognition function. Further interaction analyses were applied to examine the potential effect modifications on the association. After adjusting for confounding factors, we found an IQR increase in all three ambient particulate matters was significantly associated with a decrease in cognitive function score, with the greatest effect in the 90-day exposure window for PM₁ (β = -0.227, 95%CI: -0.376, -0.078) and PM_2.5 (β = -0.220, 95%CI: -0.341, -0.099). For ambient PM₁₀, the most significant exposure window was 60-day (β = -0.158, 95%CI: -0.274, -0.042). Interaction analyses showed that the PM-cognitive function association could be modified by gender, region, alcohol consumption, smoking, education level, chronic diseases, and depressive symptoms. In conclusion, exposure to ambient particulate matter for a certain period would significantly decrease cognitive function among middle-aged and elderly Chinese. Furthermore, individuals who were female, or lived in the midland of China were more susceptible to the adverse effect of particulate matters.

Does internet access make a difference for older adults' cognition in urban China? The moderating role of living arrangements

Since the mid-1990s, information technology, particularly the diffusion of the internet, has brought tremendous changes to communication and social participation for people in China, including older adults. At the same time, modernisation and urbanisation have transformed the way many people in China live. The traditional multigenerational household-older adults living with adult children and grandchildren-is giving way to other living arrangements, such as living alone or with a spouse only. Using wave 1 of the World Health Organization Study on Global AGEing and Adult Health collected between 2007 and 2010, we examined the extent to which home internet access might be associated with cognitive function in older adults aged 50 or over in urban China (N = 5,898), paying attention to the moderating role of living arrangements. We found that home internet access was associated with better cognitive function, and living arrangements played an essential role in such an association for different age groups. Specifically, older adults living alone benefited cognitively from internet access, particularly among those aged 50-64 and 65-74. Those living with a spouse only and those in two-generation households benefited cognitively from internet access, particularly among those aged 50-64 and 75+. Older adults age 75+ in skip-generation households benefited cognitively from internet access. Considering the trend of older adults living apart from their children, our research suggests that providing internet access to older adults in urban China, especially those living alone, could help protect their cognitive function.

Green Space, Air Pollution, Weather, and Cognitive Function in Middle and Old Age in China

Prior research has shown that environmental hazards, such as limited green space, air pollution, and harmful weather, have the strong adverse impact on older adults' cognitive function; however, most of the studies were conducted in developed countries and limited to cross-sectional analyses. China has the largest aging population in the world so the research evidence from it can offer an insight to the study in other developing countries facing similar issues and inform future public health policy and disease control. This study examined the long-term impact of environmental factors, namely, green space coverage, air pollution, and weather conditions on cognitive function using a nationally representative sample consisting of adults aged 45 years and older selected from the China Health and Retirement Longitudinal Study (CHARLS 2011–2018), the China City Statistical Yearbook, and other sources. Multilevel growth curve models were utilized for analysis and the mediator effects of physical activity and social engagement on the relationship between environmental factors and cognitive function were examined. Findings of this study showed that after controlling for sociodemographic characteristics, annual precipitation of 80 cm or more, living in areas with July temperature of 28°C or higher, urban community, and green space coverage were positively associated with cognition score at the baseline and lower precipitation, urban community, and greater green space coverage were associated with slower cognitive decline over a 7-year period. The impact of gross domestic product (GDP) seemed to take into effect more and more over time. These effects did not substantially change after weekly total hours of physical activities and levels of social engagement were added. More research on the mechanisms of the effect of environmental factors on cognition is needed such as the subgroup analyses and/or with more aspects of environmental measures.

The association between community-level socioeconomic status and cognitive function among Chinese middle-aged and older adults: a study based on the China Health and Retirement Longitudinal Study (CHARLS)

Background

Although numerous studies focused on the relationship between area socioeconomic status (SES) and health, only a few of them investigated how community-level SES was linked to late-life cognitive function as well as the potential pathways underlying this association, and very few of them focused on the context of China. This study examined how community-level SES was linked to cognitive function and the potential pathways underlying this association among middle-aged and older adults in China.

Methods

Data was drawn from the waves 1–4 of China Health and Retirement Longitudinal Study. We measured cognitive function with the components of the Telephone Interview of Cognitive Status battery. Community-level SES was derived from a sum of z scores of the percentage of the illiterate and the per-capita net income status within communities. We adopted two-level hierarchical linear regression models to explore the associations between community-level SES and cognitive function. A multilevel mediation analysis with structural equation modeling was undertaken to disaggregate the direct and indirect pathways of the associations.

Results

Higher community-level SES was associated with better cognitive function (β = 0.562, 95% CI = 0.390, 0.734), and this significant association was only present in rural participants, not in urban participants. Furthermore, we discovered the mediating effects of outdoor exercise facilities within communities (β = 0.023, 95% CI = 0.000, 0.056) and individual-level SES (β = 0.108, 95% CI = 0.057, 0.156) to explain the relationship between community SES and cognitive function.

Conclusions

These findings highlight the importance of community environmental interventions in maintaining individuals’ cognitive health in China, especially for older adults. Our results provided solid empirical evidence for reducing mental health inequalities in China, and suggested that developing an aging-friendly environment and properly distributing community resources are important to improve cognitive function of older adults.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02946-3.

Modifiable Factors Associated with Reversion from Mild Cognitive Impairment to Cognitively Normal Status: A Prospective Cohort Study

Background: Previous studies found that about 24% of the mild cognitive impairment (MCI) patients reverse to cognitive normal (CN) status. However, it is unclear which modifiable factors are associated with this reversion. Objective: To identify potential modifiable factors associated with the reversion of MCI to CN status. Methods: We conducted a prospective community-based cohort study based on 2002–2018 Chinese Longitudinal Health Longevity Survey (CLHLS). Multivariable Cox regression with least absolute shrinkage and selection operator (LASSO) penalty for variable selection was adopted to investigate the associations between reversion to CN and potential modifiable dietary/lifestyle, cardiometabolic, and psychological factors. Results: Our analysis included 7,422 MCI participants [average age: 90.0 (SD 9.5) years]. Among these participants, 1,604 (21.6%) reversed from MCI to CN with a mean (SD) follow-up of 2.9 (1.8) years. Several dietary/lifestyle factors, including daily consumption of fresh fruits (Hazard Ratio [HR]: 1.28, 95% CI: 1.15 to 1.42), engagement in reading (HR: 1.24, 95% CI: 1.00 to 1.54), housework (HR: 1.21, 95% CI: 1.08 to 1.35), and mah-jongg or other card games (HR: 1.23, 95% CI: 1.08 to 1.39), were positively associated with possibility of reversion. Cigarette smoking (HR: 0.92, 95% CI: 0.84 to 1.00) and duration of alcohol drinking (HR: 0.97, 95% CI: 0.94 to 0.99) were negatively associated with possibility of reversion. None of the modifiable cardiometabolic and psychological factors was found to be significantly associated with reversion to CN. Conclusion: This study identified several dietary/lifestyle factors associated with MCI reversion that may transfer into large-scale dementia prevention practices.

The Effect of Adult Children's Education Attainment on Their Parents' Cognitive Health: An Intergenerational Support Perspective

The purpose of this study is to examine the relationship between adult children's education attainment and their parents' cognitive health, and to further explore the mechanism of intergenerational support. Based on empirical analysis of data from China Health and Retirement Longitudinal Survey, our study finds a positive association between children's educational attainment and parents' cognitive health. This correlation is provided for by emotional communication of informal caregiving, financial support, and healthy behaviors shaped in the parents by adult children. The strength of the effect varied by the adult child's gender. While sons' education attainment significantly improves parental cognitive parameters through informal caregiving, financial support, and development of healthy behaviors, the effect of daughters' education derives from financial support and healthy behaviors, not being related to informal caregiving. The study enriches the evidence on the mobility of children's human capital toward their parents and provides practical insights for advancing children's participation in family caregiving.

Grandparenting, health, and well-being: a systematic literature review

Whether grandparenting is associated with improved health or well-being among older adults is a salient question in present-day aging societies. This systematic review compiles studies that consider the health or well-being outcomes of grandparenting, concerning (1) custodial grandparent families, where grandparents are raising grandchildren without parental presence; (2) three-generation households, where grandparents are living with adult children and grandchildren; and (3) non-coresiding grandparents, who are involved in the lives of their grandchildren. Review was based on literature searches conducted in September 2019 via Web of Science, PubMed, PsycINFO, and Ebsco. We screened 3868 abstracts across four databases, and by following the PRISMA guidelines, we identified 92 relevant articles (117 studies) that were published between 1978 and 2019. In 68% of cases, custodial grandparenting was associated with decreased health or well-being of grandparents. The few studies considering the health or well-being of grandparents living in three-generation households provided mixed findings (39% positive; 39% negative). Finally, in 69% of cases, involvement of non-coresiding grandparents was associated with improved grandparental outcomes; however, there was only limited support for the prediction that involved grandparenting being causally associated with grandparental health or well-being. Despite this, after different robustness checks (counting all nonsignificant results, taking into account the representativeness of the data and causal methodology), the main finding remains the same: the most negative results are found among custodial grandparents and three-generation households and most positive results among non-coresiding grandparents.

What doesn't kill you makes you "smarter": The long-term association between exposure to epidemic and cognition

Emerging epidemics have devastating impacts on people's lives and livelihoods. However, acting as a severe health shock, exposure to an epidemic may induce positive changes in health behaviors among survivors, thereby leading to long-lasting improvement in population health. This study examined the long-term association between exposure to the 2002-2004 severe acute respiratory syndrome outbreak and middle-aged and older Chinese adults' cognition assessed in 2011-2015. Drawing on data from the 2011-2015 China Health and Retirement Longitudinal Study, we found that community exposure to the outbreak was associated with significantly higher scores on episodic memory, after adjusting for demographic characteristics, adulthood socioeconomic status and health, and community socioeconomic conditions. No such a significant association was found for mental intactness. Mediation analysis showed that community exposure to the epidemic was associated with increased participation in social activities, maintaining close family relationships with adult children and grandchildren, and increased participation in regular physical exercise, all of which were positively associated with cognitive functioning in middle-aged and older Chinese adults. These findings suggest that positive post-epidemic behavioral changes are possible and may have long-term health benefits for survivors.

Social Relationships in Early Life and Episodic Memory in Mid- and Late Life

OBJECTIVES

This study examines the longitudinal relationships between retrospective reports of early-life social relationships (i.e., having good friends, parent-child relationship quality, and childhood neighborhood social cohesion) and episodic memory in China.

METHODS

We analyzed 2 waves of data (2011 and 2015) from the China Health and Retirement Longitudinal Study. The analytical sample included 9,285 respondents aged 45 and older at baseline. A lagged dependent variable approach was used to estimate the associations between measures of early-life social relationships and episodic memory change at the study's 4-year follow-up.

RESULTS

Retrospective reports of better early-life social relationships are significantly associated with higher levels of episodic memory performance in 2015 among middle-aged and older Chinese, controlling for episodic memory in 2011, childhood socioeconomic status, adulthood sociodemographic variables, and the history of stroke. Educational attainment accounts for a significant portion of the associations between early-life social relationships and episodic memory. In contrast, mental health and social engagement in adulthood account for a small part of these associations.

DISCUSSION

The findings suggest that positive early-life social relationships are beneficial for episodic memory in mid- and late life, and more research is needed to examine the underlying mechanisms.

Cognitive Function Among Noncustodial Grandparents in China and the United States: A Cross-National Perspective

The current study aimed to investigate the association between grandparenting and cognitive function over time in noncustodial grandparents in China and the United States. Lagged dependent variable (LDV) approach and linear regression models were applied to analyze a sample of 1,411 Chinese and 6,579 American adults aged 65 and above from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2013) and the U.S. Health and Retirement Study (HRS, 2012-2014). Grandparenting involvement was associated with less decline in episodic memory for grandparents and greater level of grandparenting had no negative effect on mental status and global cognitive function in noncustodial grandparents in China and the United States. The impact of grandparenting on cognitive function was conditioned on caregiving intensity, gender, urban/rural residence, and nation. Findings of the study suggest that greater attention on grandparenting facilitation might yield improved research, social support, policy, and interventions on cognitive health for the general older population.

Longitudinal impacts of grandparent caregiving on cognitive, mental, and physical health in China

OBJECTIVES

Although studies have documented the effects of grandparenting, little is known about grandparents' long-term health outcomes in terms of optimal engagement with grandchildren, and whether age, gender, or location make a difference. This study explores the longitudinal impacts of grandparenting on health, with considerations for subgroup differences.

METHODS

Using three waves of China Health and Retirement Longitudinal Study, we used propensity score analysis combined with multilevel analysis to examine the longitudinal effect of grandparenting (no, low-, moderate-, and high-intensity) on health (self-rated health, mobility limitations, depressive symptoms, and cognition) among 4,925 grandparents with at least one grandchild, and how impact varies by age, gender, and urban/rural areas.

RESULTS

A nonlinear relationship between grandparenting and health was observed. Compared to those not providing care, grandparents who provided care at a low-to-moderate level were more likely to have fewer mobility limitations and depressive symptoms and better cognition. High intensity had no positive impacts on health. The effects of grandparenting on health operated differently across subgroups. Older grandparents showed better physical, mental, and cognitive health compared to their younger counterparts. Both genders had fewer mobility limitations if they provided care at a low-to-moderate level, although females reported better self-rated health. Rural grandparents reported better physical health; whereas urban grandparents reported better cognition.

CONCLUSION

Grandparenting could improve health in later life; however, there are complex interactions at play. Policies aimed at supporting grandparenting should consider optimal hours of care relevant to age, gender, and urban/rural contexts.

Lifestyle differentiation among older adults: exploring the links between individuals’ behaviours, socio-demographic characteristics, health and wellbeing in later life

The association between everyday activities, health and subjective wellbeing in older adults has mostly been examined using different activities as separate variables. Which activities are likely to come together in individuals’ daily time-use patterns, or in what context, has not yet been analysed. This study looks at a broad range of spontaneously reported activities, their location and social context to identify latent behavioural classes. The data used in the study came from a sample of 200 non-institutionalised adults aged 65 and above. Activity data were collected using the Experience Sampling Method. Generalised structural equation modelling was used to identify the classes. Three distinctive behavioural classes, representing different lifestyles, emerged: passive domiciliary, active functional and social recreational. They constituted 30, 53 and 17 per cent of the sample, respectively. Class membership was related to individuals’ age, education and selected dimensions of health measured using the Nottingham Health Profile: energy levels and emotional response. There was consistency between the objectively measured class and an individual's subjective assessment of their physical and emotional health. While both class membership and subjective wellbeing were associated with health, the relationship between class and wellbeing was weak and fully explained by socio-demographic and health-related variables.

Own health, spousal health and transitions in loneliness among middle-aged and older adults in China

This study examines the effects of own and spousal health on transitions in loneliness over time among married middle-aged and older adults in China, and explores the possible gender differences in these effects using data from the three waves of the China Health and Retirement Longitudinal Study (2011–2015). The sample includes 6,422 men and 6,391 women who were married and aged 45 and older at the baseline survey. Middle-aged and older adults with poorer physical and emotional health statuses are more likely to transition into and less likely to transition out of loneliness in a two-year period. Spouse's emotional health also affects both types of transition in loneliness and spouse's functional limitation affects transition into loneliness through spouse's emotional health. In addition, for married men, their own functional limitation is significantly associated with their transitions into and out of loneliness. For married women, their spouse's functional limitation is significantly associated with their transition into loneliness and this is mainly through its association with spouse's emotional health. Also, for married women, their spouse's emotional health is significantly associated with their transition out of loneliness. Social interventions to reduce feelings of loneliness need to take a couple approach and consider both spouses’ health problems and how they may affect their daily activities and their interactions with each other and with others.

Association between social participation and cognitive function among middle- and old-aged Chinese: A fixed-effects analysis

Background

Social Participation (SP) is known to benefit cognitive function. However, whether the positive relationship holds across different types of SP and dimensions of cognitive function, and whether the statement stays true in middle- and old-aged Chinese have not been investigated. The present study aimed to understand the current patterns of SP and cognitive function in China’s context, and therefore, explore the associations between cognitive function and SP at different levels from various aspects.

Methods

A total of 7973 community residents aged 45 years and older were selected from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2015). A fixed-effects analysis was used to explore the association between changes in SP (diversity, frequency, and type) and that in cognitive function (memory and mental status) over a four-year period.

Results

Changing from no SP to more variety (β = 0.377, 95% confidence interval (CI) = 0.192-0.562 for 1 type, β = 0.703, 95% CI = 0.470-0.937 for ≥2 types) or higher frequency (β = 0.235, 95% CI = 0.007-0.462 for not regularly, β = 0.604, 95% CI = 0.411-0.798) of SP was associated with improvements in cognitive function. Playing mah-jong and using Internet were associated with improved memory but not with mental status. Sports and volunteering were associated with improved mental status but not with memory. The same pattern was observed in men and in women.

Conclusions

The study confirmed that more diversity and higher frequency of SP was associated with improved cognitive function, whereas reminded policymakers to consider cultural context when developing target strategies to improve cognitive function.

Factors Favoring and Hindering Volunteering by Older Adults and Their Relationship with Subjective Well-Being: A Mixed-Method Approach

A mixed methodology was used through the triangulation of quantitative and qualitative data to determine older adults’ perspectives regarding volunteering and identify what factors can contribute to promoting it, with special emphasis on the role that their own well-being plays in this behavior. The results reveal that satisfaction with life as a whole contributes positively to volunteer behavior and satisfaction with the groups one belongs to contributes negatively. The volunteers were less satisfied than non-volunteers with interpersonal relationships and with the groups they belong to. Knowing the opinion of the older adults with regard to volunteering and understanding how this prosocial behavior relates to their own well-being is very useful for developing strategic plans that allow future volunteers to be captured.

Physical activity and its association with cognitive function in middle- and older-aged Chinese: Evidence from China Health and Retirement Longitudinal Study, 2015

BACKGROUND

Despite the known benefits of physical activity (PA) on cognitive function, the specific dimensions of PA that are associated with cognitive function require further research in China. We aimed to explore the patterns of PA and elucidate the association between cognitive function and different levels of PA in middle aged and elderly Chinese individuals.

METHODS

A total of 8,023 participants aged ≥45 years were selected from the China Health and Retirement Longitudinal Study. The PA intensity was categorized as: vigorous (VPA), moderate (MPA), and light (LPA). The associations of frequency and duration of PA at different intensities with cognitive function were examined using the multivariable linear model, including all respondents and urban-rural subgroups.

RESULTS

Compared with those who had no VPA, those who spent 6-7 days/week (β = -0.59, 95% CI: -1.10, -0.09) or more than 240 min/each time on VPA had poorer cognitive function among rural respondents, whereas cognitive function was only associated with the duration in urban respondents. Compared with those who had no MPA, the rural respondents who spent 1-5 days/week (β = 0.66, 95% CI: 0.12, 1.20) or 6-7days/week, or spent < 2 hours each time had better cognitive function. For LPA, frequency and duration were both positively associated with cognitive function, and were observed in both rural and urban sub-groups.

CONCLUSIONS

The association between cognitive function and PA depended largely on the intensity and area. Cultural context and geographical differences should be considered when designing intervention policies.Highlights The prevalence of PA increased as the intensity decreased and was higher in rural respondents than in urban respondents.Cognitive function was related to the intensity, frequency, and duration of PA. However, the magnitude and direction of the association depended mainly on the intensity and geographical area.VPA was negatively correlated with cognitive function, and the association was significant only in rural respondents. However, MPA and LPA were positively correlated with cognitive function, while the association between LPA and cognitive function was significant in both rural and urban respondents.

The longitudinal effect of sensory loss on depression among Chinese older adults

BACKGROUND

Previous studies have suggested that sensory loss is linked to depression. However, most of these studies have been conducted in developed countries and the results are mixed.

OBJECTIVES

The current study aims to examine the longitudinal relationship between hearing loss, vision loss, dual sensory loss, and depression among Chinese older adults over four years.

METHODS

The data were obtained from the China Health and Retirement Longitudinal Survey (CHARLS). In total, 6353 Chinese older adults aged 60 years and over were included at baseline in this study. Self-reported hearing and vision status was used, and dual sensory loss was a combined variable of hearing loss and vision loss. Depressive symptoms were assessed by The Center for Epidemiologic Studies Depression Scale (CESD-10). The baseline relationship between sensory loss and depression was explored by logistic regression analyses. A logistic mixed model was used to assess whether baseline sensory loss was associated with incident depression for older adults with no depressive symptoms at baseline over four years.

RESULTS

At baseline, vision loss (OR=1.46, 95%CI: 1.19-1.79) and dual sensory loss (OR=2.14, 95%CI: 1.77-2.58) were associated with depression, while hearing loss was not. After four years, vision loss (OR=1.60, 95%CI: 1.16-2.22) and dual sensory loss (OR=1.78, 95%CI: 1.32-2.41) were associated with incident depression.

LIMITATIONS

Not all potential confounding factors are measured and adjusted in the analysis. Apart from that, all measurements of interest are self-reported scales.

CONCLUSION

Vision loss and dual sensory loss are significantly associated with both onset and increased depressive symptoms over time, while hearing loss is not associated with depression. Interactions between all types of sensory loss and social activities are not significant. Our results suggest that target mental health intervention programs should be delivered to vision loss or dual sensory loss populations.

Specific Activities and the Trajectories of Cognitive Decline Among Middle-Aged and Older Adults: A Five-Year Longitudinal Cohort Study

BACKGROUND

How specific activities influence cognitive decline among different age groups, especially the late middle-aged and the early old, remains inadequately studied.

OBJECTIVE

To examine the association between specific activities with trajectories of cognitive functions in different age groups in China.

METHODS

A longitudinal cohort study was conducted based on data from the China Health and Retirement Longitudinal Study (CHARLS). Mixed effects growth models were applied to analyze the association between specific activities and cognitive functions.

RESULTS

Interacting with friends (infrequent: β= 0.13, confidence interval [CI] = 0.03 to 0.22; daily: β= 0.19, CI = 0.09 to 0.28), playing Mah-jong or other games (infrequent: β= 0.12, CI = 0.02 to 0.22; daily:β= 0.26, CI = 0.10 to 0.42), infrequent providing help to others (β= 0.24, CI = 0.11 to 0.37), and going to a sport (infrequent: β= 0.31, CI = 0.08 to 0.54); daily: β= 0.22, CI = 0.05 to 0.38) are significantly associated with participants' memory. Infrequently playing Mah-jong or other games (β= 0.30, CI = 0.17 to 0.43) and daily sports (β= 0.24, CI = 0.03 to 0.45) are significantly associated with better mental status. Effect of each activity varies among population of different age, education level, gender, and residence.

CONCLUSION

This study identifies four social activities that are associated with better cognitive functions, and provides a comprehensive, in-depth understanding on the specific protective effect of each activity among different subgroups.

Early Child-Parent Relationship Quality and Cognitive Function in Older Rural Chinese Adults: The Mediating Role of Educational Attainment

Objectives: Framed within a life course perspective and cognitive reserve theory, this study examined the mediating role of educational attainment for the association between child-parent relationships during childhood and cognitive function among older adults in rural China. Methods: Data were obtained from three waves of the China Health and Retirement Longitudinal Study (N = 9809). We employed latent growth curve modeling to test the association among early child-parent relationship quality, educational attainment, and cognitive function in later life. Results: Early child-mother relationship quality was associated with the level and change in cognitive function. Early child-father relationship quality was only related to baseline cognitive function. Educational attainment mediated the relationship between early child-parent relationship quality with mothers and fathers and cognitive function. Discussion: Parental relationship experience in childhood was one distal factor related to cognitive function among older adults. The findings supported the long-term impacts of childhood conditions for later life health consequences.

The association between mental-physical multimorbidity and disability, work productivity, and social participation in China: a panel data analysis

Background

The co-occurrence of mental and physical chronic conditions (mental-physical multimorbidity) is a growing and largely unaddressed challenge for health systems and wider economies in low-and middle-income countries. This study investigated the independent and combined (additive or synergistic) effects of mental and physical chronic conditions on disability, work productivity, and social participation in China.

Methods

Panel data study design utilised two waves of the China Health and Retirement Longitudinal Study (2011, 2015), including 5616 participants aged ≥45 years, 12 physical chronic conditions and depression. We used a panel data approach of random-effects regression models to assess the relationships between mental-physical multimorbidity and outcomes.

Results

After adjusting for socio-economic and demographic factors, an increased number of physical chronic conditions was independently associated with a higher likelihood of disability (Adjusted odds ratio (AOR) = 1.39; 95% CI: 1.33, 1.45), early retirement (AOR = 1.37 [1.26, 1.49]) and increased sick leave days (1.25 days [1.16, 1.35]). Depression was independently associated with disability (AOR = 3.78 [3.30, 4.34]), increased sick leave days (2.18 days [1.72, 2.77]) and a lower likelihood of social participation (AOR = 0.57 [0.47, 0.70]), but not with early retirement (AOR = 1.24 [0.97, 1.58]). There were small and statistically insignificant interactions between physical chronic conditions and mental health on disability, work productivity and social participation, suggesting an additive effect of mental-physical multimorbidity on productivity loss.

Conclusion

Mental-physical multimorbidity poses substantial negative health and economic effects on individuals, health systems, and societies. More research that addresses the challenges of mental-physical multimorbidity is needed to inform the development of interventions that can be applied to the workplace and the wider community in China.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10414-7.

Productive engagement patterns and their association with depressive symptomatology, loneliness, and cognitive function among older adults

OBJECTIVES

Little is known about composite patterns of productive engagement among older people. Related, the implication of these patterns for well-being remains unclear. The present study addresses these gaps.

METHODS

The analytical sample comprised 2037 community-dwelling Singaporeans aged 60 years and above. We included nine productive activities and employed latent class analysis to identify prevalent patterns of productive engagement. Regression analysis was then conducted to investigate the association of these patterns with depressive symptomatology, loneliness, and cognitive function.

RESULTS

Four productive engagement patterns (Low Activity, Family Support, Moderate Working-Volunteering, and Working-Family Support) were identified. Compared with Low Activity, Moderate Working-Volunteering, and Working-Family Support related to lower levels of depressive symptomatology and loneliness, respectively, and both patterns were associated with better cognitive function.

CONCLUSION

Productive engagement patterns are differentially linked with depressive symptomatology, loneliness, and cognitive function. We interpret these findings with reference to the role perspective. We also discuss their policy implications.

Effect of retirement on cognitive function: a systematic review and meta-analysis

The study aimed to determine the longitudinal association between retirement and cognitive function, including global cognition and memory-related skills. This is a systematic review of longitudinal studies on the association between retirement and cognitive function, using Medline (via PubMed), Scopus, Web of Science and PsycINFO databases from inception to April 2020 and longitudinal studies on the association between retirement and cognitive function. The Newcastle-Ottawa Scale was used to assess risk of bias of included studies. Effect size (ES) and 95% CI were calculated using Cohen's d index. Meta-regressions were calculated on the basis of sample characteristics: percentage of women, years of follow-up and age at baseline. A total of 23 longitudinal studies were included in this systematic review. The pooled ES for the association of retirement with global cognition and memory-related skills was -0.01 (95% CI -0.02 to 0.00; I²: 0.0%) and -0.09 (95% CI -0.16 to 0.01; I²: 93%), respectively. Meta-regression analyses showed that length of follow-up, percentage of women in the sample and mean age at baseline did not influence the longitudinal association between retirement and adults' memory-related skills. The results of this study indicate that retirement has no negative effects on adults' global cognition and slightly adversely influences memory-related skills. Moreover, this association does not seem to be influenced by some demographic and study characteristics.

Intergenerational Ties in Context: Association between Caring for Grandchildren and Cognitive Function in Middle-Aged and Older Chinese

Grandchild caregiving is suggested to improve the elderly’s cognitive function, but the specific relationship remains under-investigated. Considering gender disparity, this study aimed to understand the relationship between grandchild caregiving and cognition. In total, 7236 Chinese residents (≥45 years old) were selected from the 2015 China Health and Retirement Longitudinal Study (CHARLS). The China Health and Retirement Longitudinal Study Harmonized Cognitive Assessment Protocol (CHARLS-HCAP) was used to measure cognition. Grandparenting was measured from three dimensions: caregiving frequency, intensity, and the number of grandchildren cared for. The relationship was examined by multivariate linear regression, with age as a moderator. The results showed that the majority of respondents provided care to their grandchildren, especially grandmothers. Grandchild caregiving was positively associated with cognition (β = 0.686, 95% CI = 0.334–1.038), especially in the older-aged group. Moderate, not regular grandparenting, or caring for one grandchild was more positively associated with cognitive function. However, intensive and regular grandchild care was significantly associated with cognition only in men. No moderating effects of age were found in women. The study confirmed that moderate intensity and frequency of caregiving was related to better cognitive function in middle-aged and older Chinese population, whereas cultural context and gender differences could be considered when designing targeted policies.

Longitudinal Evidence for the Effects of Social Group Engagement on the Cognitive and Mental Health of Chinese Retirees

BACKGROUND

Research investigating the health benefits of social group participation in the retirement transition has provided little insight into the longitudinal effects on cognitive health and the generalizability of these relationships to non-Western samples. The present paper addresses these issues by examining the effects of social group engagement on the cognitive performance and depression symptoms of Chinese older adults followed over 4 years in their transition to retirement.

METHODS

Using the China Health and Retirement Longitudinal Study (CHARLS) data, a sample of 1,297 Chinese seniors transitioning to retirement were followed between 2011 and 2013, and then 2 years later (in 2015) after retirement. Group-based social engagement was used to predict retiree cognitive performance and depression symptoms across time.

RESULTS

After controlling for established demographic covariates and close relationship factors at baseline, social group engagement at baseline positively predicted overall cognitive performance and depression symptoms. Moreover, positive change in group engagement was associated with reduced decline in cognitive performance over the 4-year retirement transition period.

DISCUSSION

The current findings demonstrate the generalizability of the health benefits of social group engagement to cognitive health and to a non-Western (Chinese) sample of retirees.

Association between rural-to-urban migration and the cognitive aging trajectories of older Chinese adults: results from a prospective cohort analysis

BACKGROUND

Increasingly, older Chinese adults from rural areas are moving to urban areas to live with their children who have already migrated to these areas. However, few studies have examined this pattern of migration and its effects on cognitive function. We aimed to investigate the association between domestic rural-to-urban migration and the trajectories of cognitive function in older Chinese adults, as well as the factors contributing to these association.

METHODS

Data for this study were drawn from three waves of the China Health and Retirement Longitudinal Study. Migrants were defined as participants who had rural hukou status (under China's household registration system) but resided in an urban area. Cognitive functions were measured using an adapted Chinese version of the Mini-Mental State Examination. We used multilevel linear regression models to examine the association between internal migration and cognitive function trajectories.

RESULTS

The study included 3876 Chinese adults aged ≥60 years at baseline. Compared with their rural non-migrant counterparts, migrants (n = 850) had higher levels of education and reported more interactions with family. Additionally, female migrants were more likely to participate in leisure activities. All cognitive function scores declined over time, but no significant differences were observed in rates of cognitive decline between migrants and non-migrants, regardless of sex. Female migrants exhibited significantly better performance in terms of total cognition (β = 0.77, P < .001) and mental status (β = 0.68, P < .001) than female non-migrants, whereas no inter-group difference was observed regarding memory (β = 0.09, P > .05). Among the male subjects, no significant differences in cognitive function levels were observed between migrants and non-migrants. A series of adjusted models revealed that psychosocial factors such as residing with children, caring for grandchildren, depression and participation in leisure activities partly explained the association between migration and cognition in women.

CONCLUSIONS

Rural-to-urban migration was positively associated with cognitive functions only in women. However, this pattern did not affect the rate of cognitive decline in either sex. Our findings provide directions for tailored interventions improving cognitive functions of older adults and rural non-migrating older adults, especially female non-migrants.