Trajectories of cognitive function and their determinants in older people: 12 years of follow-up in the Chinese Longitudinal Healthy Longevity Survey

The interaction between physical activity and ambient particulate matters on cognitive function among Chinese community-dwelling older adults

BACKGROUND

The interaction between physical activity (PA) and ambient particulate matters (PMs) on cognition is rarely investigated. Our study aimed to assess the interactions of PA and PMs on cognitive function in older adults.

METHODS

Our study comprised 3937 Chinese community-dwelling older adults. Cognition was evaluated using the Mini-Mental State Examination. PA information was gathered using the International Physical Activity Questionnaire. The data of PMs were obtained from China High Air Pollutants (CHAP). Linear regressions model and interaction plots were applied to assess and visualize the interaction of PA and PMs on cognition, respectively. Bayesian kernel machine regression (BKMR) method was employed to visualize discernible thresholds for the interaction.

RESULTS

PMs were negatively associated with MMSE scores (PM1: β = -0.40, 95 % CI: -0.58, -0.28; PM2.5: β = -0.46, 95 % CI: -0.64, -0.29; PM10: β = -0.44, 95 % CI: -0.61, -0.26), and PA was positively affiliated with MMSE scores (β = 0.18, 95 % CI: -0.01, 0.38). Interaction plots and BKMR demonstrated that adverse connotations of PMs with MMSE increased with the elevated PA levels, and the positive associations of PA with MMSE scores were attenuated by increased PMs (all Pinteraction < 0.20). Discernible thresholds for the interaction between PMs and PA on MMSE were found.

CONCLUSIONS

Our findings suggest that PA should not be taken at higher PMs concentrations, and that low level of PA could be performed in PMs polluted environment to improve cognitive function. Further experimental and cohort researches are required to reproduce our discovery.

Longitudinal association of adverse childhood experiences with cognitive function trajectories among middle-aged and older adults: group-based trajectory modeling

Introduction

Adverse childhood experiences (ACEs) impact cognitive function, but the relationship remains unclear. We aim to identify cognitive function trajectories and scrutinize the correlation between ACEs and cognitive function.

Methods

To identify cognitive trajectories, we employed a group-based trajectory model, and influential factors were determined using multinomial unordered logistic regression analysis.

Results

Three cognitive decline subgroups emerged: low-start decline, high-start stability, and mid-start decline. There is no dose-response relationship between cumulative adverse childhood experiences and cognitive function. The high-start stability group had specific residence and education traits, while sibling death affected them. The mid-start decline group was vulnerable to parental death, physical abuse, and domestic violence. The low-start decline group should consider age structure and childhood friendships.

Conclusions

No dose-response association between cumulative ACEs and cognitive decline. Still, specific ACE metrics are correlated with cognitive trajectories. We can incorporate patients' ACEs into cognitive function assessments for early risk factor identification and tailored interventions. Moreover, recognizing the influence of early-life experiences on cognitive function, we can advocate for nurturing positive family and societal environments to optimize cognitive function.

Epidemiological characteristics of centenarian deaths in China during 2013-2020: A trend and subnational analysis

BACKGROUND

Studies that comprehensively address the characteristics of centenarian deaths are rare. The present study aimed to depict the characteristics of centenarian deaths in China and their changing trends.

METHODS

Data on centenarian deaths between 2013 and 2020 were obtained from the national mortality surveillance system of China, including date, place of death (PoD), and underlying cause of death (CoD). Descriptive analyses were performed to understand the epidemiological characteristics, and a joinpoint regression model was adopted to examine the changing trends in the proportions of different PoDs, CoDs among centenarians, and centenarian deaths accounting for all deaths and deaths among people aged 65 years and older.

RESULTS

There were 46,938 registered centenarian deaths between 2013 and 2020 that included 34,311 females (73.10%) and 12,627 males (26.90%). January (12.05%), February (9.99%), and December (9.74%) were the top three months with the highest number of deaths. The proportions of deaths that occurred in homes, hospitals, and nursing homes were 81.71%, 13.63%, and 2.68%, respectively. The proportion of deaths in nursing homes increased by 9.60% (95% confidence intervals [CIs], 6.4-12.9%) from 2014 to 2020. Heart disease (35.72%) was the leading cause of death, followed by respiratory diseases (17.63%), cerebrovascular disease (15.60%), and old age (11.22%). The proportion of respiratory diseases decreased by 4.8% (95% CI, -8.8 to -0.7%), and the proportion of deaths from old age decreased by 2.3% (95% CI, -4.4 to -0.1%) per year. Shanghai had the highest proportions of deaths in hospitals (39.38%) and nursing homes (14.68%). Sichuan had the highest proportion of deaths attributed to respiratory diseases (32.30%), while Jiangsu (26.58%) and Zhejiang (23.61%) had the highest proportions of deaths from old age.

CONCLUSION

Unlike other countries, centenarian deaths in China are characterized by a higher proportion of home and heart disease deaths, and this death pattern differs across provinces.

The progression of cognitive impairment and its influencing factors in older adults based on longitudinal item response theory

BACKGROUND

Understanding the development of cognitive impairment and its influencing factors in older adults is crucial for formulating early intervention strategies.

PURPOSE

To identify the early dimensions of cognitive impairment and provide a comprehensive description of the trajectories of cognitive decline in older adults prior to death.

METHODS

Based on the data of 9883 older adults in the Chinese Longitudinal Healthy Longevity Survey from 2002 to 2018, a longitudinal item response theory (Longitudinal IRT) model including covariates was applied to estimate the following parameters. The items in which older adults encountered obstacles first had the least difficulty parameters (δ). The earlier the information curve of an item is lifted, the more information it provides in the early stages of cognitive impairment. Regression coefficient (β) represents the relative rate of cognitive decline. The cognitive impairment values estimated from the Longitudinal IRT were fitted to a mixed-effects model to examine cognitive impairment trajectories.

RESULTS

'Draw the figure on B Card' (δ = -0.816) was the most challenging item, followed by 'recalling 'clothes" (δ = 0.348) and 'recalling 'apples" (δ = 0.419), while 'name the 'pen" (δ = 4.402) was the simplest instruction for the old adults. The curves of the items in the recall dimension began to rise in the early stages of cognitive impairment. Cognitive impairment of older adults who were women (β = 0.061), elder (β = 0.111), smokers (β = 0.060), living in rural areas (β = 0.052), not participating in organised social activities (β = 0.092), suffering from hypertension (β = 0.022), hyperglycaemia (β = 0.035), dyslipidaemia (β = 0.314), low education levels (β = 0.128), manual labourers (β = 0.027), and eventual development of dementia (β = 0.212) exhibited a more accelerated progression. These individuals also had poorer cognitive trajectories.

CONCLUSION

Recall is the earliest dimension of cognitive impairment. The subjects who were women, elder, smokers, living in rural areas, not participating in organised social activities, suffering from hypertension, hyperglycaemia, dyslipidaemia, low education, manual labourers, and eventually development of dementia, had a faster descending speed and poorer trajectories.

Risk and protective factors for cognitive decline in Brazilian lower educated older adults: A 15-year follow-up study using group-based trajectory modelling

BACKGROUND

Patterns of cognitive change and modifiable factors for cognitive decline versus stable cognitive trajectories have rarely been described in lower-educated older adults.

OBJECTIVES

We aimed to identify long-term trajectories of cognitive functioning and possible factors associated with cognitive decline.

DESIGN AND PARTICIPANTS

We used data from 1,042 adults aged ≥ 60 participating in the Health, Welfare and Aging Study (SABE), São Paulo, Brazil, without cognitive impairment at baseline. Data were collected across four waves (2000-2015). Group-based trajectory modelling was used to identify cognitive trajectories. Associations with socioeconomic variables, childhood background, lifestyle, and cardiovascular risk factors were explored using weighted multinomial logistic regressions.

MEASUREMENTS

The abbreviated Mini-Mental State Examination was used to measure cognition.

RESULTS

Three cognitive trajectories were identified: stable (n= 754, 68.6%), mild-decline (n= 183, 20.8%), and strong-decline (n= 105, 10.7%). At baseline, respondents in the strong-decline group were more likely to be older than those with stable and mild-decline trajectories. Furthermore, participants in both the mild and strong-decline groups were more likely to have no schooling, be divorced/separated, receive less than 4 monthly wages, and be underweight (BMI < 18.5) compared to the stable group. Finally, the mild-decline group was more likely to have lived in rural areas during childhood than participants located in a stable trajectory.

CONCLUSIONS

Our findings suggest that interventions to reduce cognitive decline for low-educated older adults might include strategies addressing inequalities and improving modifiable risk factor burden.

Influencing factors, gender differences and the decomposition of inequalities in cognitive function in Chinese older adults: a population-based cohort study

BACKGROUND

Evidence remains limited and inconsistent for assessing cognitive function in Chinese older adults (CFCOA) and inequalities in cognitive function in Chinese older adults (ICFCOA) and exploring their influencing factors and gender differences. This study aimed to identify influencing factors and inequality in CFCOA to empirically explore the existence and sources of gender differences in such inequality and analyse their heterogeneous effects.

METHODS

Based on data from the China Health and Retirement Longitudinal Study (CHARLS) for three periods from 2011 to 2015, recentered influence function unconditional quantile regression (RIF-UQR) and recentered influence function ordinary least squares (RIF-OLS) regression were applied to assess influencing factors of CFCOA, while grouped treatment effect estimation, Oaxaca-Blinder decomposition, and propensity score matching (PSM) methods were conducted to identify gender differences in ICFCOA and influencing factors, respectively.

RESULTS

The results showed heterogeneous effects of gender, age, low BMI, subjective health, smoking, education, social interactions, physical activity, and household registration on CFCOA. Additionally, on average, ICFCOA was about 19.2-36.0% higher among elderly females than among elderly males, mainly due to differences in characteristic effects and coefficient effects of factors such as marital status and education.

CONCLUSIONS

Different factors have heterogeneous and gender-differenced effects on CFCOA and ICFCOA, while the formation and exacerbation of ICFCOA were allied to marital status and education. Considering the severe ageing and the increasing incidence of cognitive decline, there is an urgent need for the government and society to adopt a comprehensive approach to practically work for promoting CFCOA and reducing ICFCOA.

Late Life Cognitive Function Trajectory Among the Chinese Oldest-Old Population-A Machine Learning Approach

Informed by the biopsychosocial framework, our study uses the Chinese Longitudinal Healthy Longevity Survey (CLHLS) dataset to examine cognitive function trajectories among the oldest-old (80+). Employing K-means clustering, we identified two latent groups: High Stability (HS) and Low Stability (LS). The HS group maintained satisfactory cognitive function, while the LS group exhibited consistently low function. Lasso regression revealed predictive factors, including socioeconomic status, biological conditions, mental health, lifestyle, psychological, and behavioral factors. This data-driven approach sheds light on cognitive aging patterns and informs policies for healthy aging. Our study pioneers non-parametric machine learning methods in this context.

Identifying and predicting physical limitation and cognitive decline trajectory group of older adults in China: A data-driven machine learning analysis

OBJECTIVE

This study aimed to utilize data-driven machine learning methods to identify and predict potential physical and cognitive function trajectory groups of older adults and determine their crucial factors for promoting active ageing in China.

METHODS

Longitudinal data on 3026 older adults from the Chinese Longitudinal Healthy Longevity and Happy Family Survey was used to identify potential physical and cognitive function trajectory groups using a group-based multi-trajectory model (GBMTM). Predictors were selected from sociodemographic characteristics, lifestyle factors, and physical and mental conditions. The trajectory groups were predicted using data-driven machine learning models and dynamic nomogram. Model performance was evaluated by area under the receiver operating characteristics curve (AUROC), area under the precision-recall curve (PRAUC), and confusion matrix.

RESULTS

Two physical and cognitive function trajectory groups were determined, including a trajectory group with physical limitation and cognitive decline (14.18 %) and a normal trajectory group (85.82 %). Logistic regression performed well in predicting trajectory groups (AUROC = 0.881, PRAUC = 0.649). Older adults with lower baseline score of activities of daily living, older age, less frequent housework, and fewer actual teeth were more likely to experience physical limitation and cognitive decline trajectory group.

LIMITATION

This study didn't carry out external validation.

CONCLUSIONS

This study shows that GBMTM and machine learning models effectively identify and predict physical limitation and cognitive decline trajectory group. The identified predictors might be essential for developing targeted interventions to promote healthy ageing.

Feasibility of an oral health promotion program among older people in geriatric care facilities, Shanghai, China: a pre/post-implementation study

BACKGROUND

The oral health of older people is closely related to their overall health. Timely and effective intervention in oral issues is necessary to maintain their overall health. This study aimed to evaluate the feasibility and effectiveness of an Oral Health Promotion Program (OHPP) in Geriatric Care Facilities (GCFs).

METHODS

The OHPP was implemented in two GCFs and evaluated using a pre/post-design. Questionnaires on self-efficacy and attitude for providing oral care were sent to 42 nurse participants before and three months after the implementation of the OHPP. Outcomes of 295 patient participants were assessed at four time points (T1-baseline, T2-one month, T3-two months, and T4-three months post-implementation) including Activities of Daily Living (ADL), Mini-Mental State Examination (MMSE), and Oral Health Assessment Tool (OHAT).

RESULTS

The oral health and daily activity ability of patient participants showed an improving trend at four time points pre/post-implementation of the OHPP. The proportion of patients with healthy mouths (OHAT: 0-3 points) increased from 29.8 to 67.8% and their scores of OHAT and ADL were significantly better at T4 compared to T1, T2, and T3 (p < 0.001). Self-efficacy (SE-PMC: T1 = 18.93 ± 3.18, T4 = 28.83 ± 6.56, p < 0.001) and attitude (A-PMC: T1 = 18.78 ± 3.09, T4 = 28.20 ± 6.03, p < 0.001) for oral care among nurse participants improved after the implementation of the OHPP.

CONCLUSIONS

This study highlights the feasibility of implementing OHPP within GCFs, potentially enhancing the oral health and daily living activities of older individuals. Integrating the OHPP into routine care in geriatric settings is not only practical but also widely acceptable, offering a proactive approach to address oral health disparities among older residents. Stakeholders can maximize the impact of the OHPP by fostering collaboration among healthcare professionals, administrators, and residents, ultimately improving oral health outcomes and overall quality of life of older residents.

TRIAL REGISTRATION

ChiCTR2000035236 (registration date: 04/08/2020).

Sex differences in cognitive function trajectories and their determinants in older adults: Evidence from the Chinese longitudinal healthy longevity survey

OBJECTIVES

To examine sex differences in the cognitive trajectories of a nationally representative sample of older people living in China and to explore potential determinants of these trajectories.

METHODS

The study included 2230 women and 2171 men who were cognitively healthy and aged over 60 at the first observation from the Chinese Longitudinal Healthy Longevity Survey based on the 2008-2018 cohort. Cognitive function was measured using the Chinese version of the Mini-Mental State Examination (MMSE). Group-based trajectory modeling was used to identify potential heterogeneity of longitudinal changes over the 10 years in each gender. Logistic regression was used to investigate associations between baseline characteristics (age, education, fertility history, sleep length, physical activity, and health status and behaviors) and trajectory classes.

RESULTS

Three trajectories (labeled stable, slow decline, and rapid decline) were identified according to the changes in MMSE scores for both women and men. For the women, both the slow and rapid decline groups accounted for a larger proportion (14.7% and 11.0%, respectively) than the male decline groups (8.1% and 6.6%, respectively), and the women had a lower baseline MMSE score with a faster decline. In the multivariable logistic regression analyses, older age, less education, older age at first birth, poorer functional abilities, hearing impairment, and lower baseline MMSE scores were significantly associated with cognitive decline in both the female and male groups compared to the stable group. For the women, sleeping over 9 h was also associated with a rapid cognitive decline trajectory, while current exercise and being overweight/obese were protective factors against cognitive decline.

CONCLUSIONS

The women had an overall more serious cognitive decline than men. The potential determinants of cognitive decline identified in this study could be considered for developing specific intervention strategies aimed at promoting a healthy brain and preventing cognitive decline in different sexes, especially in low-income and developing countries.

Latent trajectories of recent and delayed memory and their predictors: evidence from SHARE

OBJECTIVES

Cognitive decline is common in the old age, but some evidence suggests it may already occur during adulthood. Previous studies have linked age, gender, educational attainment, depression, physical activity, and social engagement to better cognitive performance over time. However, most studies have used global measures of cognition, which could mask subtle changes in specific cognitive domains. The aim of this study is to examine trajectories of recent and delayed memory recall from a variable-centered perspective, in order to elucidate the impact of age, gender, educational attainment, depression, physical activity, and social engagement on recent and delayed memory both at initial time and across a 10-year period.

DESIGN AND PARTICIPANTS

The sample was formed by 56,616 adults and older adults that participated in waves 4 to 8 of the Survey of Health, Aging and Retirement in Europe (SHARE).

ANALYSES

We used latent growth modeling to establish latent recent and delayed memory trajectories, and then tested the effects of the aforementioned covariates on the latent intercept and slopes.

RESULTS

Results showed that both recent and delayed recall display a quadratic trajectory of decline. All covariates significantly explained initial levels of immediate and delayed recall, but only a few had statistically significant effects on the slope terms.

CONCLUSIONS

We discuss differences between present results and those previously reported in studies using a person-centered approach. This study provides evidence of memory decline during adulthood and old adulthood. Further, results provide support for the neural compensation reserve theory.

Selenium attenuates the association of co-exposure to arsenic, cadmium, and lead with cognitive function among Chinese community-dwelling older adults

The effects of interactions between the toxic and essential metal mixtures on cognitive function are poorly understood. This study aims to identify the joint association of arsenic (As), cadmium (Cd), and lead (Pb) with cognitive function in older adults and the moderating role of selenium (Se), zinc (Zn), and copper (Cu) in this association. This study included 1000 community-dwelling older adults. Cognitive function was assessed by the Mini-Mental State Examination (MMSE). Blood concentrations of As, Cd, Pb, Se, Zn, and Cu were measured using inductively coupled plasma mass spectrometry. Linear regression and Bayesian kernel machine regression (BKMR) models were applied to assess the individual and joint associations of As, Cd, and Pb with cognitive function and to examine whether Se, Zn, and Cu (individually and as a mixture) modified these associations. In the adjusted single-metal models, both Cd (β = - 0.37, 95% CI: - 0.73 to - 0.01) and Pb (β = - 0.44, 95% CI: - 0.86 to - 0.02) were associated with MMSE scores, while Se (β = 0.71, 95% CI: 0.30 to 1.13) exhibited a positive relationship with MMSE scores. Univariate exposure-response functions from BKMR models showed similar results. Moreover, the toxic metal mixture (As, Cd, and Pb) exhibited a significant negative association with MMSE scores in a dose-response pattern, with Pb being the greatest contributor within the mixture. The negative association of Pb alone or the toxic metal mixture with MMSE scores became weaker at higher concentrations of Se within its normal range, especially when Se levels were greater than the median (89.18 μg/L). Our findings support that Se can attenuate the negative associations of exposure to single Pb or the As, Cd, and Pb mixtures with cognitive function. Future prospective studies are needed to replicate our findings.

Cognitive Function Trajectories and Factors among Chinese Older Adults with Subjective Memory Decline: CHARLS Longitudinal Study Results (2011-2018)

Older adults with subjective cognitive decline are at increased risk of future pathological cognitive decline and dementia. Subjective memory decline is an early sign of cognitive decline; preventing or slowing cognitive decline in at-risk populations remains an elusive issue. This study aimed to examine the cognitive trajectories and factors in older adults with subjective memory decline. Latent growth curve models (LGCMs) were fitted to examine the cognitive function trajectories and factors among 1465 older adults (aged 60+ years) with subjective memory decline. Data were obtained from four waves from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2018), which is a large nationally representative sample of the Chinese population. The results showed that older adults with better initial cognition had a slower decline rate, which may be accelerated by advanced age, low-level education, a rapid decrease in instrumental activities of daily living (IADL) ability, and rapid increase in depression levels. This study was the first to examine the trajectories of cognitive function and its factors in a high-risk population with subjective memory decline. These findings may guide prevention approaches to tackle the issues of cognitive function decline and dementia.

Body mass index and trajectories of the cognition among Chinese middle and old-aged adults

This study aims to investigate the association between trajectories of the cognition and body mass index (BMI) among Chinese middle and old-aged adults. A total of 5693 adults (age 45 +) whose cognitive score is higher than average at the baseline were included from China Health and Retirement Longitudinal Study (CHARLS:2011–2015). Cognitive function was measured by Mini-mental state examination (MMSE) in Chinese version. The Group-based trajectory modeling (GBTM) was adopted to identify the potential heterogeneity of longitudinal changes over the past 5 years and to investigate the relationship between baseline BMI and trajectories of cognitive function. Three trajectories were identified in results: the slow decline (37.92%), the rapid decline (6.71%) and the stable function (55.37%). After controlling for other variables, underweight (BMI < 18.5 kg/m2) was associated with the rapid and slow decline trajectories. Obesity (BMI > 28 kg/m2) was associated with the slow decline trajectory. High-risk people of cognitive decline can be screened by measuring BMI.

Associations between trajectories of social participation and functional ability among older adults: Results from the China Health and Retirement Longitudinal Study

Introduction

Functional ability (FA) and social participation (SP) are important indicators of healthy aging, both their trajectories are heterogeneous. It is little known about how the SP trajectories affects FA trajectories.

Methods

FA was assessed by 20 items covering the ability of meeting basic needs and mobility. SP was assessed by frequency of participating in 10 social activities. Group-based trajectory modeling (GBTM) was used to identify the trajectories of FA and SP of the participants.

Results

Two FA trajectories were identified: low baseline-decline tendency (16.1%) and high baseline-stable tendency (83.9%) trajectories. Two SP trajectories were also identified: low baseline-stable tendency (58.5%) and high baseline-increase tendency (41.5%) trajectories. After controlling for the potential covariates, participants among the high baseline-increase tendency SP trajectory group also had significantly higher odds ratios to be belonged in high baseline-stable tendency FA trajectory group (ORs = 2.64, 95%CI = 1.98-3.05).

Conclusions

High-increasing social participation had a protective effect to maintain high baseline-stable tendency functional ability among older adults. These findings suggest social participation appears to have great benefits on promoting healthy aging in China.

Gender differences in the correlation between body mass index and cognitive impairment among the community-dwelling oldest-old in China: a cross-sectional study

OBJECTIVE

This study investigates gender differences in the correlation between body mass index (BMI) and cognitive impairment among Chinese community-dwelling oldest-old.

SETTING

Twenty-three provinces in China. Participants' mini-mental state examination (MMSE) scores <24 were considered cognitive impairment. Furthermore, the assessment standards of BMI status were classified into four categories: obese (BMI >30), overweight (25≤BMI≤30), normal (18.5≤BMI<25) and underweight (BMI <18.5).

PARTICIPANTS

A total of 9218 older adults (age 80+) were included from the 2018 wave of Chinese Longitudinal Healthy Longevity Study.

METHODS

Cognitive impairment, BMI and other covariates consisted of the sociodemographic variables, health behaviours and health status were collected. Cognitive impairment was assessed by the MMSE. Inverse probability weighting procedure was adopted to deal with bias due to dropout.Logistic regression was conducted to examine the correlation between BMI and cognitive impairment.

RESULTS

Among 9218 respondents, 3837 were males. Overall, the percentage of participants with cognitive impairment was 44.7%, with 32.1% among males and 53.7% among females. After controlling for other variables, males who were either overweight or underweight and females who were underweight were found to have higher risk of cognitive impairment among the oldest-old. Age, education, economic status, physical activity, activities of daily living, hypertension as well as heart disease were the predicting factors of cognitive impairment.

CONCLUSIONS

The relationship between BMI and cognitive impairment differs between male and female oldest-old, suggesting that we should pay attention to different BMI groups and adopt precise prevention strategies based on gender.

Television watching, reading, cognition, depression and life satisfaction among middle-aged and older populations: A group-based trajectory modelling analysis of national data

This retrospective cohort study aimed to identify heterogeneous cognition, depression, and life satisfaction trajectory groups, and to examine the independent contributions of watching television and reading to these trajectories among middle-aged and older adults. A sample was taken from the Taiwan Longitudinal Study on Aging (TLSA) with measures of cognition, depression, life satisfaction, watching television, and reading during 12 years of follow-up (N = 4440). Group-based trajectory models and multinomial logistic regressions were used. The findings showed that the cohort was separated into three global cognition groups of low-cognition (n = 376), declining-cognition (n = 805), and maintained-cognition (n = 2718); three episodic memory groups of high-declining (n = 540), middle-stable (n = 2066), and improving groups (n = 1293); three depression groups of low-to-low (n = 2571), median-to-high (n = 960), and high-to-high groups (n = 368); and three life satisfaction groups of low- (n = 1133), middle- (n = 977), and high-level groups (n = 1789). Also, the findings demonstrated that after adjusting for covariates, those who did not watch television or read at the baseline had independently significantly increased odds of having lower global cognitive function, higher depression, and lower life satisfaction over time versus those who watched television or read almost every day. Based on the findings obtained, group-based trajectories of cognition, depression, and life satisfaction scores identified distinct subgroups among TLSA participants. Moreover, the findings suggest that healthcare providers need to develop more targeted population interventions to ensure successful aging. Healthcare providers can encourage older adults, particularly new retirees, to participate in leisure activities (i.e., watching television and reading) to reduce prevalence rates of cognitive impairment and depression.

Healthy aging index and its link with relative education between individual and neighborhood: a population-based, cohort study

OBJECTIVES

There is increasing recognition of the importance of neighborhood socioeconomic status (SES) for establishing an age-friendly society. Despite the benefits of improved neighborhood SES, little is known about the link of relative education between individuals and neighborhoods with healthy aging. This study aims to construct a healthy aging index (HAI) accounting for indicators' interlinkages and to test the association of the HAI with relative education between neighborhoods and individuals.

METHODS

The study used data from the China Health and Retirement Longitudinal Study from 2011 to 2018, including middle-aged and older adults (≥ 45 years). The final sample comprised 11633 participants residing in 443 neighborhoods with 34123 observations. Based on 13 health indicators, a hybrid method integrating network analysis with TOPSIS was applied to construct a HAI accounting for health interlinkages. Weighted multilevel linear and ordered logistic models were used to estimate the effects of neighborhood education.

RESULTS

Among the 11633 participants (mean [SD] age, 58.20 [8.91] years; 6415 women [52.82%]), the mean (SD) HAI was 48.94 (7.55) at baseline, showing a downward trend with age. Approximately 10% of participants had a HAI trajectory characterized by a low starting point and fast decline. A one-year increase in neighborhood education was independently associated with a 0.37-point increase (95% CI, 0.23-0.52) in HAI. Regardless of individual education, each participant tended to gain benefits from a neighborhood with higher education. However, the effects of increased neighborhood education were weaker for individuals whose education was lower than the neighborhood average.

CONCLUSIONS

The HAI is an interaction system. Improving neighborhood education was beneficial to healthy aging, but individuals with lower education relative to the neighborhood average may experience poor person-environment fit and obtain fewer benefits from improved neighborhood education. Thus, in the process of improving neighborhood SES, individual-based interventions should be conducted for individuals whose education level is lower than the neighborhood average to achieve person-environment fit.

Associations Between the Prevalence, Treatment, Control of Hypertension and Cognitive Trajectories Among Chinese Middle-Aged and Older Adults

OBJECTIVE

To investigate the associations between the prevalence, treatment, control of hypertension, and trajectories of cognitive performance among Chinese middle-aged and older adults.

DESIGN

An 8-year longitudinal study.

SETTING

China.

PARTICIPANTS

Chinese middle-aged and older adults.

MEASUREMENTS

Data from the China Health and Retirement Longitudinal Study were utilized. Group-based trajectory modeling was performed to identify heterogeneous trajectories of episodic memory and executive function. Multinomial logistic regression models were established to examine the relationships between hypertension status and cognitive trajectories, stratified by sex.

RESULTS

Three episodic memory trajectories and four executive function trajectories were identified in males and females. Hypertension prevalence was associated with worse episodic memory and executive function trajectories in females. Compared with treated hypertensives, untreated hypertensives were more likely to have worse executive function trajectories, both in males and females. Among male treated hypertensives, those with uncontrolled blood pressure (BP) had worse episodic memory trajectories compared with their counterparts with controlled at standard targets, while females with uncontrolled BP demonstrated worse executive function trajectories compared with females controlled at standard targets. There was basically no significant difference in cognitive trajectory memberships between individuals with controlled hypertension corresponding to intensive or standard BP targets.

CONCLUSIONS

The prevalence of hypertension was associated with worse cognitive trajectories, and the treatment and control of hypertension were related to more favorable cognitive trajectories. Intensive BP control target was not associated with additional benefit beyond the recognized protective effect of standard BP targets on cognitive trajectories.

Trajectories of physical functioning and its predictors in older adults: A 12-year longitudinal study in China

Objective

Maintaining and delaying a decline in physical function in older adults is critical for healthy aging. This study aimed to explore trajectories, critical points of the trajectory changes, and predictors among older people in the Chinese community.

Design

This study was one with a longitudinal design performed in China.

Setting and participants

The target population was community-dwelling older adults aged over 65 years. A total of 2,503 older adults from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were included in this study.

Methods

Physical functioning was measured by instrumental activities of daily living (IADL). Population-based trajectory models were used to identify potential heterogeneity in longitudinal changes over 12 years and to investigate associations between baseline predictors and different trajectories for different cohort members using LASSO regression and logistic regression.

Results

Four trajectories of physical function were identified: slow decline (33.0%), poor function and moderate decline (8.1%), rapid decline (23.5%), and stable function (35.4%). Older age, male sex, worse self-reported health status, worse vision status, more chronic diseases, worse cognitive function, and a decreased frequency of leisure activity influenced changes in the trajectory of physical function. Having fewer teeth, stronger depressive symptoms, a lack of exercise, and reduced hearing may increase the rate of decline.

Conclusion and implications

Four trajectories of physical function were identified in the Chinese elderly population. Early prevention or intervention of the determinants of these trajectories can maintain or delay the rate of decline in physical function and improve healthy aging.

Effects of cognitive ageing trajectories on multiple adverse outcomes among Chinese community-dwelling elderly population

BACKGROUND

Whether cognitive ageing trajectory is related to common functional deficits independent of initial cognitive function remains inconclusive. We aimed to explore the adverse health effect and potential predictive factors of distinct cognitive trajectories among Chinese older adults.

METHODS

Three thousand five hundred eighty-one community-dwelling older adults who completed three consecutive cognitive function examinations with the Mini-Mental State Examination (MMSE) over 5 years and were without cognitive impairment at enrollment were included. A group-based trajectory model was used to estimate cognitive ageing trajectories. Multivariable-adjusted odds ratio (OR) and 95% confidence intervals (CI) were computed with logistic regression models to identify potential baseline determinants and health effect of cognitive trajectories on various adverse outcomes.

RESULTS

Two distinct cognitive ageing trajectories were identified with about 5.3% of the study participants ascribed to the rapidly decreasing group. Subjects with rapidly decreasing cognition showed significantly higher odds (OR, 95%CI) of experiencing frailty (4.04, 2.77-5.86), falls (2.01, 1.05-3.70), balance impairment (4.20, 2.75-6.38), high fall risk (5.66, 2.67-11.77) based on the Tinetti total score, disability in activities of daily living (1.76, 1.19-2.56), disability in instrumental activities of daily living (1.52, 1.05-2.19), and motor cognitive risk syndrome (2.24, 1.23-3.98) compared with their steadily decreasing counterparts. Individuals with older age, low education level, no marriage, high score of rapid eye movement behavior disorders, poor physical and cognitive function at baseline were more predisposed to an accelerated cognitive decline.

CONCLUSIONS

Faster cognitive decline was independently associated with higher risk of multiple adverse events. Our findings put more emphasis on a routine and constant surveillance of cognitive function among community-dwelling older adults.

Interpretable classifiers for prediction of disability trajectories using a nationwide longitudinal database

OBJECTIVES

To explore the heterogeneous disability trajectories and construct explainable machine learning models for effective prediction of long-term disability trajectories and understanding the mechanisms of predictions among the elderly Chinese at community level.

METHODS

This study retrospectively collected data from the Chinese Longitudinal Healthy Longevity and Happy Family Study between 2002 and 2018. A total of 4149 subjects aged 65 + in 2002 with completed activities of daily living (ADL) information for at least three waves were included. The mixed growth model was used to identify disability trajectories, and five machine learning models were further established to predict disability trajectories using epidemiological variables. An explainable approach was deployed to understand the model's decisions.

RESULTS

Three distinct disability trajectories, including normal class (77.3%), progressive class (15.5%), and high-onset class (7.2%), were identified for three-class prediction. The latter two were further merged into abnormal class, accompanied by normal class for two-class prediction. Machine learning, especially random forest and extreme gradient boosting achieved good performance in both two tasks. ADL, age, leisure activity, cognitive function, and blood pressure were key predictors.

CONCLUSION

The findings suggest that machine learning showed good performance and maybe of additional value in analyzing quality indicators in predicting disability trajectories, thereby providing basis to personalize intervention measures.

Predictors of Mortality in 433 Nonagenarians Inside the Mugello Study: A 10 Years Follow-Up Study

OBJECTIVE

to identify the predictors of mortality in a cohort of nonagenarians inside the "Mugello study" after 10 years follow-up.

METHODS

Information on sociodemographic data, cognitive and functional status, lifestyle, medical history, and drug use was collected from 433 non-selected participants aged 90-99 years, living in the Mugello area (Italy). Participants were followed over 10 years and their dates of death were retrieved from the municipal registers. Cox regression analysis was used to determine significant potential prognostic factors.

RESULTS

The mortality rate was 96.5%. Cox proportional hazards analysis showed that a lower cognitive status was significantly associated with higher mortality as well as a poorer functional status, a higher comorbidity, and a higher number of drugs consumption.

DISCUSSION

Impaired cognitive function, loss of functional independence, higher comorbidity, and higher drugs intake were the stronger predictors of mortality.

Predicting the long-term cognitive trajectories using machine learning approaches: A Chinese nationwide longitudinal database

OBJECTIVES

This study aimed to explore the long-term cognitive trajectories and its' determinants, and construct prediction models for identifying high-risk populations with unfavorable cognitive trajectories.

METHODS

This study included 3502 older adults aged 65-105 years at their first observations in a 16-year longitudinal cohort study. Cognitive function was measured by the Chinese version Mini Mental State Examination. The heterogeneity of cognitive function was identified through mixed growth model. Machine learning algorithms, namely regularized logistic regression (r-LR), support vector machine (SVM), random forest (RF), and super learner (SL) were used to predict cognitive trajectories. Discrimination and calibration metrics were used for performance evaluation.

RESULTS

Two distinct trajectories were identified according to the changes of MMSE scores: intact cognitive functioning (93.6%), and dementia (6.4%). Older age, female gender, Han ethnicity, having no schooling, rural residents, low-frequency leisure activities, and low baseline BADL score were associated with a rapid decline in cognitive function. r-LR, SVM, and SL performed well in predicting cognitive trajectories (Sensitivity: 0.73, G-mean: 0.65). Age and psychological well-being were key predictors.

CONCLUSION

Two cognitive trajectories were identified among older Chinese, and the identified key factors could be targeted for constructing early risk prediction models.

The association between essential trace element mixture and cognitive function in Chinese community-dwelling older adults

BACKGROUND

The evidence about the effect of essential trace element (ETE) mixture on cognitive function amongst older adults is limited. This study aims to evaluate the associations of single ETEs and ETE mixture with cognitive function using a representative sample of community-dwelling older adults in China.

METHODS

A total of 3814 older adults were included in the study. Urinary concentrations of selenium (Se), vanadium (V), cobalt (Co), strontium (Sr), and molybdenum (Mo) were detected by inductively coupled plasma mass spectrometry. Cognitive function in older adults was assessed using the Chinese version of the Mini-Mental State Examination (MMSE). Linear regression and Bayesian kernel machine regression (BKMR) were performed to explore the associations of single ETEs and ETE mixture with cognitive function, respectively.

RESULTS

Linear regression showed that urinary levels of Se and V were positively associated with MMSE scores in the adjusted single-element models. BKMR also showed marginally positive associations of Se and V with MMSE scores. Moreover, higher urinary levels of ETE mixture were significantly associated with increased MMSE scores in a dose-response pattern, and Se was the most important contributor within the mixture. Both Se and V demonstrated positive additive effects on the associations of other ETEs with MMSE scores, whereas Co had a negative additive effect.

CONCLUSIONS

V and Se are positively associated with cognitive function, individually and as a mixture. ETE mixture exhibits a linear dose-response association with improved cognitive function, with Se being the most important component within the mixture. Mixture analyses rather than single ETE analyses may provide a real-world perspective on the relationship between ETE mixture and cognitive function. Further cohort studies are needed to clarify the association of multiple ETEs with cognitive function.

Association between biomass fuel use and the risk of cognitive impairment among older populations in China: a population-based cohort study

BACKGROUND

Cohort studies on the impact of biomass fuel use for cooking on cognitive impairment among older population are still lacking in China and elsewhere. The aim of this study was to examine whether biomass fuel use for cooking is associated with cognitive impairment in Chinese adults aged 65 years or older.

METHODS

The prospective population-based cohort study of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) included participants aged 65 years or older in 2014 who were followed-up until 2018 in 23 provinces in China. The Mini-Mental State Examination (MMSE) was used to assess cognitive function, and cognitive impairment was defined as total MMSE scores less than 18. The association between biomass fuel use and cognitive impairment was evaluated using the Cox proportional hazards model.

RESULTS

Of the 4145 participants included at baseline, participants who reported that they used biomass fuel for cooking (40.43%; IR: 3.11 versus 2.77 per 100 person-years; aHR: 1.27, 95% CI: 1.02-1.58) had a higher risk of cognitive impairment compared with participants who used clean fuels (53.75%). A stratified analyses showed greater effect estimates of cognitive impairment in the older people that lived in the rural areas (aHR: 1.444, 95% CI: 1.08-3.90) and never smoked (aHR: 1.33, 95% CI: 1.04-1.71).

CONCLUSIONS

These findings demonstrated that biomass fuel used for cooking was associated with cognitive impairment, as defined by MMSE, in a population-based study of elderly in China. To prevent cognitive impairment, the structure of cooking fuels requires improvements.

Childhood infectious diseases and old age cognitive functioning: a nationally representative sample of community-dwelling older adults

BACKGROUND

Cumulative evidence suggests that health-related risk factors during midlife and old-age are associated with cognitive impairment. However, studies are needed to clarify the association between early-life risk factors and impaired cognitive functioning to increment existing knowledge.

OBJECTIVE

To examine the association between childhood infectious diseases and late-life cognitive functioning in a nationally representative sample of older adults.

PARTICIPANTS

Eligible respondents were 2994 community-dwelling individuals aged 65-85.

MEASUREMENTS

Cognitive functioning was assessed using the Mini-Mental State Examination (MMSE). Childhood infectious diseases (i.e. chicken pox, measles, and mumps) were self-reported. The study covariates were age, sex, highest educational level achieved, smoking status, body mass index, and depression. The primary statistical analysis examined the association between the number of childhood infectious diseases and total MMSE scores, accounting for all study covariates. Regression models of progressive complexity were examined for parsimony. The robustness of the primary results was tested in 17 sensitivity analyses.

RESULTS

The most parsimonious model was a linear adjusted model (Bayesian Information Criterion = 12646.09). Late-life cognitive functioning significantly improved as the number of childhood infectious diseases increased (β = 0.18; 95% CI = 0.11, 0.26; p < 0.001). This effect was not significantly attenuated in all sensitivity analyses.

CONCLUSION

The current study results are consistent with prior ecological findings indicating that some childhood infectious diseases are associated with better cognitive functioning in old-age. This points to an early-life modifiable risk factor associated with older-life cognitive functioning. Our results may reflect selective mortality and/or beneficial effects via hormetic processes.