Cognitive impairment and mortality among the oldest-old Chinese

Change in Healthy Lifestyle and Subsequent Risk of Cognitive Impairment Among Chinese Older Adults: A National Community-Based Cohort Study

BACKGROUND

The association between change in lifestyle and cognitive impairment remains uncertain.

OBJECTIVES

To investigate the association of change in lifestyle with cognitive impairment.

METHODS

In this study, 4 938 participants aged 65 or older were involved from the Chinese Longitudinal Healthy Longevity Survey for years 2008-2018. A weighted healthy lifestyle score was derived from 4 lifestyle factors (smoking, alcohol consumption, physical activity, and diet). Multivariable Cox proportional hazards regression models were applied to investigate the associations between 3-year changes in healthy lifestyle (2008-2011) and cognitive impairment (2011-2018).

RESULTS

Researchers documented 833 new-onset of cognitive impairments more than 20 097 person-years of follow up. Compared with those in the persistently unhealthy group, those in the improved and persistently healthy groups had a lower risk of cognitive impairment, with the multivariate-adjusted hazard ratios (HRs) of 0.67 (95% confidence interval (CI): 0.55, 0.83) and 0.53 (95% CI: 0.40, 0.71), respectively. Furthermore, a significant interaction was observed between change in lifestyle and sex (p-interaction = .032); the HRs were 0.48 (95% CI, 0.34, 0.69) for the improved group and 0.41 (95% CI: 0.26, 0.64) for persistently healthy group among male vs 0.81 (95% CI, 0.63, 1.04) and 0.64 (95% CI, 0.44, 0.92) among female, respectively.

CONCLUSIONS

This study suggests that improving or maintaining a healthy lifestyle can significantly mitigate the risk of cognitive impairment in Chinese older adults. Additionally, researcher's findings emphasize the significance of maintaining a healthy lifestyle and highlights the potential positive impact of improving previous unhealthy habits, especially for older women.

Multimorbidity measures associated with cognitive function among community-dwelling older Chinese adults

INTRODUCTION

Older adults with multimorbidity are at high risk of cognitive impairment development. There is a lack of research on the associations between different multimorbidity measures and cognitive function among older Chinese adults living in the community.

METHODS

We used the Chinese Longitudinal Healthy Longevity Survey from 2002 to 2018 and included data on dementia-free participants aged ≥65 years. Multimorbidity measures included condition counts, multimorbidity patterns, and trajectories. The association of multimorbidity measures with cognitive function was examined by generalized estimating equation and linear and logistic regression models.

RESULTS

Among 14,093 participants at baseline, 43.2% had multimorbidity. Multimorbidity patterns were grouped into cancer-inflammatory, cardiometabolic, and sensory patterns. Multimorbidity trajectories were classified as "onset-condition," "newly developing," and "severe condition." The Mini-Mental State Examination scores were significantly lower for participants with more chronic conditions, with cancer-inflammatory/cardiometabolic/sensory patterns, and with developing multimorbidity trajectories.

DISCUSSION

Condition counts, sensory pattern, cardiometabolic pattern, cancer-inflammatory pattern, and multimorbidity developmental trajectories were prospectively associated with cognitive function.

HIGHLIGHTS

Elderly individuals with a higher number of chronic conditions were associated with lower MMSE scores in the Chinese Longitudinal Healthy Longevity Survey data. MMSE scores were significantly lower for participants with specific multimorbidity patterns. Individuals with developing trajectories of multimorbidity were associated with lower MMSE scores and a higher risk of mild cognitive impairment.

Exploring the Role of Social Factors in Cognitive Frailty among South Korean Older Adults

Cognitive frailty, which is characterized by the co-occurrence of physical frailty and cognitive impairment, poses significant risks to the well-being and independence of elderly individuals. Previous research has established that demographic, health-related, and social factors contribute to both physical frailty and cognitive decline. However, the role of social factors in influencing cognitive frailty remains unclear. This study aims to identify the relationship between social factors and cognitive frailty among Korean older adults living in the community. We performed secondary analyses of data from the 2020 Survey on Older Adults. After entering demographic factors and health-related factors into the logistic model as covariates, this study explored the association between cognitive frailty and social factors, including living arrangements, social support, the frequency of engagement in social activities per week, and satisfaction with friends and community. Among participants, approximately 2.9% had cognitive frailty, 3.2% had only physical frailty, and 21.9% had only cognitive decline. Lower levels of satisfaction with friends and the community and infrequent participation in social activities were strongly correlated with cognitive frailty. These findings emphasize the necessity of public health programs that encourage older individuals' social involvement. A supportive social environment can be fostered through initiatives that promote community events, group activities, and volunteerism. Public health policies should prioritize the development and maintenance of social activity centers that offer various programs to prevent progression to cognitive frailty in older adults.

Association of 24-Hour movement behavior and cognitive function in older Taiwanese adults

OBJECTIVES

This study investigates how 24-hour movement behaviors (physical activity, sedentary time, sleep) relate to cognitive performance in older adults.

METHODS

213 adults (aged 65+) wore accelerometers to track activity. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Isotemporal substitution analysis examined how replacing one behavior with another affected cognition.

RESULTS

Increased light physical activity was linked to better cognitive function, whereas longer sleep had a negative impact. Replacing 30 min of sedentary behavior or sleep with light physical activity improved orientation, attention, language, and short-term memory. Substituting moderate-to-vigorous physical activity did not have the same cognitive benefit.

CONCLUSION

Encouraging older adults to replace sedentary time or excess sleep with light physical activity could support cognitive health and potentially help prevent dementia. These findings have implications for public health strategies promoting cognitive well-being in aging populations.

Associations of cognitive impairment and functional limitation with all-cause mortality risk in older adults: A population-based study from the National Health and Nutrition Examination Survey

Cognitive impairment and functional limitation are commonly observed in older adults. They have a complex correlation, and both are risk factors for mortality. This prospective cohort study aimed to explore the independent and joint impact of cognitive impairment and functional limitations on all-cause mortality in older adults. A total of 3,759 participants aged ≥ 60 years who had available information on mortality data, cognitive function, physical function, and covariates were enrolled. Cox proportional hazards regression models were employed to assess the independent and joint impacts of cognitive impairment and functional limitation on all-cause mortality. Smoothing curve fitting was used to show the nonlinear relationship between the Digit Symbol Coding (DSC) score and all-cause mortality. An interaction between cognitive impairment and functional limitation was identified when examining their associations with all-cause mortality. Cognitive impairment and functional limitation independently correlated with all-cause mortality risk even after adjusting for covariates and performing mutual adjustments (HR for cognitive impairment: 1.34, 95% CI 1.15-1.56; HR for functional limitation: 1.50, 95% CI 1.32-1.70). When the DSC score was > 18, as the score increased, the risk of death significantly decreased (HR 0.99, 95% CI 0.98-0.99). Participants with both cognitive impairment and functional limitation had the highest hazard ratio for all-cause mortality (HR 1.98, 95%CI 1.63-2.40). In summary, cognitive impairment and functional limitation independently correlated with increased all-cause mortality risk. A higher DSC score was a protective factor reducing the premature mortality risk. Older adults with cognitive impairment and functional limitation demonstrated the highest all-cause mortality risk.

The bi-directional relationships between diversified leisure activity participation and cognitive function in older adults in China: separating between-person effects from within-person effects

OBJECTIVE

To examine the bi-directorial association between diversified leisure activity participation and cognitive function over a 7-year period.

METHODS

Data analyzed was from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a large-scale longitudinal national study. The baseline survey was conducted in 2011 with follow-up every three years. We traced a total of 2718 participants over a period of 7 years. We used adjusted random intercept cross-lagged panel models (RI-CLPMs) to examine the bi-directorial associations between diversified leisure activity participation and cognitive function.

RESULTS

We observed bi-directorial associations between diversity of leisure activity and cognitive function across waves at the between-person and within-person levels. The adjusted random intercept cross-lagged panel models fitted the data appropriately, and the 3-year cross-lagged effects of prior diversified leisure activity participation on cognitive function (β = 0.058, p < 0.01) and cognitive function on subsequent diversified leisure activity participation (β = 0.047, p < 0.05) were significant. The results remained after adjusting the model for baseline sex, age, educational level, marital status and current residence, the number of chronic diseases, ADL, depressive symptoms, sleep quality, smoking, and drinking.

CONCLUSION

This study suggests that a reciprocal causality relationship between diversified leisure activity participation and cognitive function, indicating a "positive circle" that further promotes cognition over time.

Anti-Inflammatory Diet and Protein-Enriched Diet Can Reduce the Risk of Cognitive Impairment among Older Adults: A Nationwide Cross-Sectional Research

BACKGROUND

Cognitive impairment (CI) is a common mental health disorder among older adults, and dietary patterns have an impact on cognitive function. However, no systematic researches have constructed anti-inflammatory diet (AID) and protein-enriched diet (PED) to explore their association with CI among older adults in China.

METHODS

The data used in this study were obtained from the 2018 waves of the China Longitudinal Health and Longevity Survey (CLHLS). We construct AID, PED, and calculate scores for CI. We use binary logistic regression to explore the relationship between them, and use restrictive cubic splines to determine whether the relationships are non-linear. Subgroup analysis and sensitivity analysis were used to demonstrate the robustness of the results.

RESULTS

A total of 8692 participants (mean age is 83.53 years) were included in the analysis. We found that participants with a higher AID (OR = 0.789, 95% confidence interval: 0.740-0.842, p < 0.001) and PED (OR = 0.910, 95% confidence interval: 0.866-0.956, p < 0.001) score showed lower odds of suffering from CI. Besides, the relationship between the two dietary patterns and CI is linear, and the results of subgroup analysis and sensitivity analysis are also significant.

CONCLUSION

Higher intakes of AID and PED are associated with a lower risk of CI among older adults, which has important implications for future prevention and control of CI from a dietary and nutritional perspective.

A non-linear relationship between blood pressure and mild cognitive impairment in elderly individuals: A cohort study based on the Chinese longitudinal healthy longevity survey (CLHLS)

BACKGROUND

Hypertension is an established risk factor for mild cognitive impairment (MCI) in elderly individuals. Nevertheless, the impact of different levels of blood pressure on the progression of MCI remains uncertain. This study aims to investigate the non-linear relationship between blood pressure and MCI in the elderly and detect the critical blood pressure threshold, thus, improving blood pressure management for individuals at high risk of MCI.

METHODS

Data was obtained from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) cohort. We chose normal cognitive elderly individuals who entered the cohort in 2014 for a 5-year follow-up to observe the progression of MCI. Subsequently, we utilized the Cox regression model to identify risk factors for MCI and conducted a Cox-based restricted cubic spline regression (RCS) model to examine the non-linear relationship between systolic blood pressure (SBP) and diastolic blood pressure (DBP) with MCI, determining the critical blood pressure threshold for MCI progression.

RESULTS

In the elderly population, female (HR = 1.489, 95% CI: 1.017-2.180), lacking of exercise in the past (HR = 1.714, 95% CI: 1.108-2.653), preferring animal fats (HR = 2.340, 95% CI: 1.348-4.061), increased age (HR = 1.061, 95% CI: 1.038-1.084), increased SBP (HR = 1.036, 95% CI: 1.024-1.048), and increased DBP (HR = 1.056, 95% CI: 1.031-1.081) were associated with MCI progression. After adjusting factors such as gender, exercise, preferred types of fats, and age, both SBP (P non-linear < 0.001) and DBP (P non-linear < 0.001) in elderly individuals exhibited a non-linear association with MCI. The risk of MCI rose when SBP exceeded 135 mmHg and DBP was in the range of 80-88 mmHg. However, when DBP exceeded 88 mmHg, there was a declining trend in MCI progression, although the HR remained above 1. The identified critical blood pressure management threshold for MCI was 135/80 mmHg.

CONCLUSION

In this study, we discovered that risk factors affecting the progression of MCI in elderly individuals comprise gender (female), preferring to use animal fat, lack of exercise in the past, increased age, increased SBP, and increased DBP. Additionally, a non-linear relationship between blood pressure levels and MCI progression was confirmed, with the critical blood pressure management threshold for MCI onset falling within the prehypertensive range.

Cognitive Function, Healthy Lifestyle, and All-Cause Mortality among Chinese Older Adults: A Longitudinal Prospective Study

BACKGROUND

Both cognitive decline and unhealthy lifestyles have been linked to an elevated risk of mortality in older people. We aimed to investigate whether a healthy lifestyle might modify the association between cognitive function and all-cause mortality in Chinese older populations.

METHODS

The final analysis included 5124 individuals free of dementia, selected from the Chinese Longitudinal Healthy Longevity Survey from 2011 to 2018. Cognitive function was assessed in 2011 using the Mini-Mental State Examination (MMSE). A lifestyle score was calculated based on five lifestyle factors, including smoking, alcohol consumption, physical activity, diet, and body mass index. Cox proportional hazards models were performed to evaluate the association between baseline cognitive function and the risk of all-cause mortality, with an interaction term of cognitive function and lifestyle score being added to the models.

RESULTS

The average age of participants was 81.87 years old at baseline. During a median follow-up of 6.4 years, 1461 deaths were documented. Both higher cognitive function (HR: 0.96; 95% CI: 0.96-0.97) and a healthier lifestyle (HR: 0.92; 95% CI: 0.87-0.97) were significantly associated with a reduced risk of mortality. We found that lifestyle significantly modified the association of cognitive function with mortality (p for interaction = 0.004). The inverse relation between cognitive function and mortality was found to be more pronounced among participants with a healthier lifestyle. Of note, among the lifestyle scores component, diet showed a significant interaction with mortality (p for interaction = 0.003), and the protective HR of the all-cause mortality associated with higher MMSE scores was more prominent among participants with healthy diets compared with unhealthy diets.

CONCLUSIONS

Our study indicates that cognitive decline is associated with a higher risk of mortality, and such associations are attenuated by maintaining a healthy lifestyle, with a particular emphasis on healthy diet.

Combined associations of cognitive impairment and psychological resilience with all-cause mortality in community-dwelling older adults

BACKGROUND

Cognitive impairment and psychological resilience are closely related in older adults, but their combined effect on mortality has not been reported. Using a nationally representative sample from the Chinese Longitudinal Healthy Longevity Study, this study examined the interactions between cognitive impairment and psychological resilience and their associations with overall survival.

METHODS

A total of 32,349 community-dwelling older adults (86.85 ± 11.16 years, 56.06 % female) were enrolled in 1998, 2000, 2002, 2005, 2008, 2011, and 2014; all participants were followed until 2018. Cognitive function and psychological resilience were assessed using the Mini-Mental State Examination (MMSE) and the 7-item psychological resilience questionnaire (PRQ), respectively. Illiterate subjects with an MMSE score <18, or literate subjects with an MMSE score <24 were defined as having cognitive impairment. Cox proportional risk regressions were used to analyze the association of cognitive impairment and psychological resilience with all-cause mortality.

RESULTS

After 146,993.52 person-years of follow-up, 23,349 older adults died. Both MMSE and PRQ scores (as continuous variables) were negatively associated with mortality risk after adjusting for all covariates. The hazard ratio (HR) of all-cause mortality for cognitive impairment was not significantly moderated by levels of psychological resilience (P-interaction = 0.094). In joint analyses, participants with combined cognitive impairment and low resilience (by the median of PRQ: < 25 points) had the highest risk of mortality (adjusted-HR: 1.56, 95%CI: 1.48-1.61), which was higher than that of patients with either condition alone. There was a significant additive interaction effect of cognitive impairment and low resilience on all-cause mortality (relative excess risk due to interaction: 0.11, 95 % CI: 0.09-0.13), and 7 % of the overall mortality risk was attributable to their synergistic effect.

CONCLUSIONS

Cognitive impairment and low resilience are synergistically associated with increased risk of all-cause mortality in community-dwelling older adults. The potential mechanisms underlying this combined effect warrant further exploration.

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.

Effects of cognitive reserve on cognitive frailty among older adults: A population-based prospective cohort study

AIM

We investigated the effect of lifespan cognitive reserve and its components on cognitive frailty among older adults.

METHODS

A total of 4922 participants aged ≥65 years were recruited in 2008 and were followed up in 2011 from the Chinese Longitudinal Healthy Longevity Survey. Cognitive frailty was determined through the simultaneous presence of physical frailty (pre-frailty or frailty) and mild cognitive impairment, excluding concurrent dementia. The assessment of physical frailty and mild cognitive impairment was based on the Fatigue, Resistence, Ambulation, Illness, Loss of weight (FRAIL) (Fatigue, Resistence, Ambulation, Illness, Loss) and Mini-Mental State Examination scale, respectively. The lifespan cognitive reserve consisted of education attainment, occupational complexity and later-life leisure activities. We used logistic regression models to estimate the risk of cognitive frailty associated with the lifespan cognitive reserve and its components.

RESULTS

A higher level of lifespan cognitive reserve, higher educational attainment or leisure activities engagement, but not occupational complexity, were associated with lower risk of incident cognitive frailty. Furthermore, cognitive, social and physical activities were associated with lower risk of incident cognitive frailty.

CONCLUSION

Cognitive reserve, particularly educational attainment and leisure activities, can protect from cognitive frailty. This implicates that individuals should accumulate cognitive reserve in their lifespan, and older adults should actively participate in leisure activities to prevent cognitive frailty. Geriatr Gerontol Int 2024; 24: 398-403.

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

Association between cognitive dysfunction and diabetes in patients over 65 years old: a cross-sectional study using propensity score matching

OBJECTIVES

To investigate the association between diabetes and cognitive dysfunction in the elderly population, and examine the impact of cognitive dysfunction on level of activities of daily living (ADL) in patients with diabetes.

METHODS

Data analysis was conducted on 2,951 individuals aged over 65 years from the Chinese Longitudinal Healthy Longevity Survey cohort. Propensity score matching was utilized to mitigate selection bias. Multivariate binary logistic regression was performed to analyse the association between diabetes and cognitive dysfunction in the study subjects. In addition, the relationship between ADL and cognitive function in patients with diabetes was analysed using the Wilcoxon rank-sum test.

RESULTS

A significant association (p = 0.017) was found between diabetes and the occurrence of cognitive dysfunction in older adults. Subgroup analyses revealed that diabetes patients with cognitive dysfunction exhibited a worse ADL dependence compared with those without cognitive dysfunction (p < 0.001).

CONCLUSION

These findings indicate that diabetes is associated with cognitive dysfunction in older adults. Meanwhile, there is an association between cognitive impairment and ADL level in subjects with diabetes. As such, healthcare professionals should pay close attention to the occurrence of cognitive dysfunction and ADL decline during diagnosis and treatment, and proactive prevention and intervention strategies should be implemented.

Interaction between activities of daily living and cognitive function on risk of depression

Objective

There is a lack of literature about the joint effects of activities of daily living (ADL) limitation and cognitive impairment on depression. This study aimed to estimate the association of ADL limitation and cognitive impairment with depression among Chinese older adults aged 65 and above and to test their interaction on both additive and multiplicative scales.

Methods

Data was drawn from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), including 11,025 eligible participants. Logistic regression models were fitted, and both multiplicative and additive interactions for ADL limitation and cognitive impairment were tested.

Results

A total of 3,019(27.4%) participants reported depressive symptoms. After controlling for potential confounding factors, ADL limitation and cognitive impairment were both positively associated with depression. The adjusted additive interaction of basic and instrumental activities of daily living limitation were 2.47 (95%CI:1.92-3.19) and 3.67 (95%CI:2.88-4.66), respectively, but the multiplicative interaction items were both insignificant.

Conclusion

ADL limitation and cognitive impairment were both risk factors for depression among Chinese older adults. Moreover, the significant interaction of ADL limitation and cognitive impairment was found in the additive model, suggesting that improving ADL may be helpful in reducing the risk of depression among older people with cognitive impairment.

Dietary factors in relation to the risk of cognitive impairment and physical frailty in Chinese older adults: a prospective cohort study

PURPOSE

The study aimed to investigate the independent associations of dietary factors with cognitive impairment (CI) and physical frailty (PF) among Chinese older adults.

METHODS

This study included 10,734 participants (mean age = 78.7 years) free of CI and PF at baseline from the Chinese Longitudinal Health Longevity Survey. Dietary intake was collected using a simplified food frequency questionnaire every 3-4 years. The Chinese version Mini-Mental State Examination was used to assess cognition function, participants with a score below 18 were defined as CI. PF was defined using the activities of daily living, instrumental activities of daily living, and functional limitation-related questions. The outcome was defined as the first onset of either CI or PF. Competing risk models were used to estimate the corresponding hazard ratios (HRs) and the 95% confidence intervals (95% CIs).

RESULTS

During the study follow-up (mean = 8.1 years), a total of 1220 CI cases and 1451 PF cases were newly identified. Higher frequency of fruits intake was associated with a lower hazard of CI (HR = 0.75, 95% CI 0.58-0.97), whereas higher intake of preserved vegetables demonstrated an opposite association (HR = 1.23, 95% CI 1.07-1.42). In terms of PF, we observed a lower risk associated with higher meat and poultry intake (HR = 0.72, 95% CI 0.61-0.88). In particular, a significant protective association of fish and aquatic products intake with PF was observed among participants with ≥ 28 natural teeth (HR = 0.52, 95% CI 0.27-0.99).

CONCLUSION

Our findings suggest divergent roles of major dietary factors in the development of CI and PF among Chinese older adults.

Multimorbidity, healthy lifestyle, and the risk of cognitive impairment in Chinese older adults: a longitudinal cohort study

BACKGROUND

Evidence on the association between multimorbidity and cognitive impairment in Chinese older population is limited. In addition, whether a healthy lifestyle can protect cognitive function in multimorbid older population remains unknown.

METHODS

A total of 6116 participants aged ≥ 65 years from the Chinese Longitudinal Healthy Longevity Survey were followed up repeatedly. The number of coexisting chronic diseases was used for assessing multimorbidity and cardiometabolic multimorbidity. Three lifestyle statuses (unhealthy, intermediate, and healthy) were defined based on a lifestyle score covering smoking, alcohol drinking, body mass index, outdoor activities, and dietary pattern. Cognitive impairment was defined as the Mini-Mental State Examination score < 24. A modified Poisson regression model with robust error variance was used to assess the associations between multimorbidity, healthy lifestyle, and cognitive impairment.

RESULTS

During a median follow-up period of 5.8 years, 1621 incident cases of cognitive impairment were identified. The relative risk (RR) of cognitive impairment associated with heavy multimorbidity burden (≥ 3 conditions) was 1.39 (95% confidence interval: 1.22-1.59). This association declined with age, with RRs being 3.08 (1.78-5.31), 1.40 (1.04-1.87), and 1.19 (1.01-1.40) in subjects aged < 70 years, ≥ 70 and < 80 years, and ≥ 80 years, respectively (P for interaction = 0.001). Compared to unhealthy lifestyle, a healthy lifestyle was related to an approximately 40% reduced risk of cognitive impairment regardless of multimorbidity burden. Among the 5 lifestyle factors assessed, daily outdoor activities and a healthy dietary pattern showed convincing protective effects on cognitive function.

CONCLUSIONS

The relationship between multimorbidity and cognitive impairment is age-dependent but remains significant in the population aged 80 years or older. A healthy lifestyle may protect cognitive function regardless of the multimorbidity burden. These findings highlight the importance of targeting individuals with heavy multimorbidity burden and promoting a heathy lifestyle to prevent cognitive impairment in Chinese older population.

Cognitive performance and all-cause mortality in community dwellers of Amerindian ancestry living in rural Ecuador: A population-based, longitudinal prospective study

OBJECTIVE

There is limited information on mortality risk in individuals with cognitive impairment living in rural Latin America. In this study, we assess the association between cognitive impairment and all-cause mortality in adults of Amerindian ancestry living in rural Ecuador.

PATIENTS AND METHODS

Middle-aged and older adults enrolled in the population-based Three Villages Study cohort were followed prospectively in order to estimate mortality risk according to their baseline cognitive performance as determined by the Montreal Cognitive Assessment (MoCA). Results were adjusted for demographics, level of education, traditional cardiovascular risk factors, symptoms of depression, severe tooth loss, and oily fish intake (factors previously associated with mortality in the study population).

RESULTS

Analysis included 1022 individuals followed for an average of 7.8 ± 3.4 years. Mean MoCA score was 21.2 ± 5.4 points (median: 22 points), with 334 (32.7%) individuals showing cognitive impairment, as evidenced by a MoCA score ≤ 19 points (the cutoff for poor cognitive performance based on previous studies in the same population). A total of 150 (14.7%) individuals died during the follow-up. Crude mortality rate was 2.87 per 100 person-years (95% C.I.: 2.08 - 3.96). For individuals with normal cognition, the mortality rate was 1.21 (95% C.I.: 0.92 - 1.50) while for those with cognitive impairment the rate increased to 3.48 (95% C.I.: 2.73 - 4.23). A multivariate Cox-proportional hazards model, confirmed that individuals with cognitive impairment had a significantly higher mortality risk than those without cognitive impairment (HR: 1.52; 95% C.I.: 1.05 - 2.18).

CONCLUSIONS

Cognitive impairment is associated with mortality in the study population.

The effects of heatwave on cognitive impairment among older adults: Exploring the combined effects of air pollution and green space

The association between heatwaves and cognitive impairment in older adults, especially the joint effect of air pollution and green space on this association, remains unknown. The present cohort study used data from waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 2008 to 2018. Heatwaves were defined as having daily maximum temperature ≥ 92.5th, 95th and 97.5th percentile that continued at least two, three and four days, measured as the one-year heatwave days prior to the participants' incident cognitive impairment. Data on the annual average air pollutant concentrations of fine particulate matter (PM2.5) and ozone (O3) as well as green space exposure (according to the Normalized Difference Vegetation Index (NDVI)) were collected. Time-varying Cox proportional hazards models were constructed to examine the independent effect of heatwaves on cognitive impairment and the combined effect of heatwaves, air pollution, and green space on cognitive impairment. Potential multiplicative interactions were examined by adding a product term of air pollutants and NDVI with heatwaves in the models. The relative excess risk due to interaction (RERI) was calculated to reflect additive interactions. We found that heatwave exposure was associated with higher risks of cognitive impairment, with hazard ratios (HRs) and 95 % confidence intervals (CIs) ranging from 1.035 (95 % CI: 1.016-1.055) to 1.058 (95 % CI: 1.040-1.075). We observed a positive interaction of PM2.5 concentrations, O3 concentrations, lack of green space, and heatwave exposure on a multiplicative scale (HRs for product terms >1). Furthermore, we found a synergistic interaction of PM2.5 concentrations, O3, lack of green space, and heatwave exposure on an additive scale, with RERIs >0. These results suggest that extreme heat exposure may be a potential risk factor for cognitive impairment in older adults. Additionally, coexposure to air pollution and lack of green space exacerbated the adverse effects of heatwaves on cognitive function.

Does frequent tea consumption provide any benefit to cognitive function in older adults? Evidence from a national survey from China in 2018

Objectives

This present study aims to investigate the effect of tea consumption on cognitive function and examine possible psychosocial mechanisms in older adults.

Participants and methods

The data of this study came from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey(CLHLS), and a total of 11,910 valid samples were included. We used ordinary least squares (OLS) to explore whether frequent tea consumption had significant effect on the cognitive function of older people. The problem of endogeneity was addressed by using a propensity score matching (PSM). Then we further explored the psychosocial mechanisms of the effect using a stepwise regression approach.

Results

Frequent tea consumption produced a positive effect on Mini-Mental State Examination (MMSE) score (coefficient = 0.340, p < 0.01), and PSM showed similar results. Specifically, the positive effect of green tea (coefficient 0.409, p < 0.01) was significantly greater than the other teas (coefficient 0.261, p < 0.1). Moreover, frequent tea drinkers were 59.7, 74.8, and 81.8% less likely to have severe, moderate and mild cognitive impairment respectively, compared to infrequent tea drinkers (p < 0.01). Levels of depression and sleep quality had partial mediation effect for frequent tea consumption on cognitive function, accounting for 27.6 and 3.5% of the total effect, respectively.

Conclusion

Frequent tea consumption was found to have beneficial effects on cognitive function, especially in older people with green tea intake. Sleep quality and levels of depression partially mediated the association between frequent tea consumption and cognitive function among Chinese older adults.

Bidirectional relationship between frailty and cognitive function among Chinese older adults

BACKGROUND

Frailty and cognitive function are two common aging-related conditions among older adults. This study examined the bidirectional relationship between frailty and cognitive function according to sex.

METHODS

All older adults aged ≥65 years who participated in the 2008 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey were included in this study. Binary logistic regression and generalized estimating equation models were used to determine the bidirectional relationship between frailty and cognitive function in cross-sectional and cohort studies, and sex differences were assessed.

RESULTS

We included 12,708 participants who were interviewed in the baseline study. The participants' mean (standard deviation) age was 85.6 (11.1%) years. In the cross-sectional study, the multivariate-adjusted odds ratio (OR; 95% confidence interval [CI]) for pre-frailty and frailty among participants with cognitive impairment was 3.68 (3.29-4.13). Older adults with pre-frailty and frailty had higher risks of cognitive impairment (OR = 3.79, 95% CI: 3.38-4.25). The GEE models showed that pre-frailty and frailty predicted a higher likelihood of cognitive impairment (OR = 2.02, 95% CI, 1.67-2.46) during follow-up. Moreover, the temporal relationship between these relationships differed slightly by sex. Older women with cognitive impairment at baseline were more likely to develop pre-frailty or frailty than did older men.

CONCLUSIONS

This study demonstrated a significant bidirectional relationship between frailty and cognitive function. Moreover, this bidirectional relationship varied by sex. These findings confirm the need to integrate sex-specific interventions for frailty and cognitive functioning problems to improve the quality of life of older adults.

Tourism experiences reduce the risk of cognitive impairment in the Chinese older adult: a prospective cohort study

Background

Given the etiological complexity of cognitive impairment, no effective cure currently exists for precise treatment of dementia. Although scholars have noted tourism's potential role in managing cognitive impairment and mild dementia, more robust empirical investigation is needed in this area. This study aimed to examine the associations between tourism and cognitive impairment and dementia in older Chinese adults.

Method

From a nationwide community-based cohort, 6,717 individuals aged ≥60 were recruited from 2011 to 2014, of whom 669 (9.96%) had had at least one tourism experience in the 2 years prior to enrollment. All the participants were then prospectively followed up until 2018. The association between tourism and cognitive impairment was examined by the Cox proportional hazards regression model. The adjusted hazard ratio (aHR) and its 95% confidence interval (CI) were calculated to evaluate the effect of tourism experience on cognitive impairment and dementia.

Results

A total of 1,416 individuals were newly diagnosed with cognitive impairment and 139 individuals with dementia onset during follow-up. The incidence of cognitive impairment was significantly lower among participants with tourism experiences (316.94 per 10,000 person-years) than those without such experiences (552.38 per 10,000 person-years). Cox regression showed that tourism decreased the risk of cognitive impairment (aHR = 0.69, 95% CI: 0.41-0.62) when adjusted for behavioral covariates and characteristics. Compared with participants without tourism experiences, those with 1, 2, and ≥3 tourism experiences had a lower risk of cognitive impairment with the aHRs of 0.72 (95% CI: 0.52-0.99), 0.65 (0.42-1.01), and 0.68 (0.44-0.98), respectively. Tourism experiences also reduced participants' risk of dementia (aHR = 0.41, 95% CI: 0.19-0.89).

Conclusion

Our findings demonstrated associations between tourism and reduced risks of cognitive impairment and dementia in older Chinese adults. Thus, tourism could serve as a novel approach to dementia prevention.

Predicting mild cognitive impairment among Chinese older adults: a longitudinal study based on long short-term memory networks and machine learning

Background

Mild cognitive impairment (MCI) is a transitory yet reversible stage of dementia. Systematic, scientific and population-wide early screening system for MCI is lacking. This study aimed to construct prediction models using longitudinal data to identify potential MCI patients and explore its critical features among Chinese older adults.

Methods

A total of 2,128 participants were selected from wave 5-8 of Chinese Longitudinal Healthy Longevity Study. Cognitive function was measured using the Chinese version of Mini-Mental State Examination. Long- short-term memory (LSTM) and three machine learning techniques, including 8 sociodemographic features and 12 health behavior and health status features, were used to predict individual risk of MCI in the next year. Performances of prediction models were evaluated through receiver operating curve and decision curve analysis. The importance of predictors in prediction models were explored using Shapley Additive explanation (SHAP) model.

Results

The area under the curve values of three models were around 0.90 and decision curve analysis indicated that the net benefit of XGboost and Random Forest were approximate when threshold is lower than 0.8. SHAP models showed that age, education, respiratory disease, gastrointestinal ulcer and self-rated health are the five most important predictors of MCI.

Conclusion

This screening method of MCI, combining LSTM and machine learning, successfully predicted the risk of MCI using longitudinal datasets, and enables health care providers to implement early intervention to delay the process from MCI to dementia, reducing the incidence and treatment cost of dementia ultimately.

Association of Hearing Status and Cognition With Fall Among the Oldest-Old Chinese: A Nationally Representative Cohort Study

OBJECTIVES

The oldest-old (aged ≥80 years) are the most rapidly growing population and age is related to hearing impairment (HI) and cognitive decline. We aimed to estimate the association between HI and fall, and the effect of different cognitive states on this association among the oldest-old Chinese population.

DESIGN

A total of 6931 Chinese oldest-old were included in the 2018 cross-cohort from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The presence of HI was identified by using a dichotomized metric of self-reported hearing status. Cognitive function was evaluated by using the modified Mini-Mental State Examination (MMSE). Cognitive impairment was defined as the MMSE score below 24 points. Data on fall history were collected by questionnaires survey from the participants or their relatives. We studied the association of hearing status and cognitive function with fall by using multivariable logistic regressions, upon adjustment of sociodemographic characteristics, lifestyles, and health conditions.

RESULTS

Our participants were aged 92 (range 80 to 117) on average, with 60.1% being women. In total, 39.1% of the participants had reported HI, 50.1% had cognitive impairment, and 26.2% had a history of falling. Participants with HI had a higher incidence of cognitive impairment (79.4%), as compared with their counterparts without HI (31.3%). Compared with those without HI, HI patients had a higher risk of falling after full adjustment for potential confounders (OR = 1.16 [95% confidence interval, CI, 1.01, 1.32], p = 0.031). In comparison with HI participants without cognitive impairment, HI patients with cognitive impairment had a higher fall risk (OR = 1.45 [95% CI = 1.23, 1.72], p < 0.001).

CONCLUSIONS

Association of hearing status and cognition with fall was, for the first time, examined on the basis of a nationally-representative oldest-old Chinese population. Poor cognitive performance was common in individuals with HI, and those with HI and cognitive impairment further increased the risk of falling.

Sex differences in cognitive function among Chinese older adults using data from the Chinese longitudinal healthy longevity survey: a cross-sectional study

Objective

To compare the sex differences in cognitive function and its influencing factors among Chinese older adults.

Method

We conducted a cross-sectional study by using data from the China Longitudinal Healthy Longevity Survey (CLHLS). According to the 32 provinces and 4 municipalities directly under the Central Government of China, 3-5 counties or districts were randomly selected in each province or city (except Tibet), and then 1-3 villages or streets were randomly selected in each county or district, from which the target population was sampled. Mini Mental State Examination (MMSE) was used to assess the cognitive function of 9,262 older adults aged 65 and above in China. Descriptive analysis was applied to demonstrate the participants' demographic characteristics, health-related behaviors, social and non-social activity, disease status, mental and sleep condition. And then, univariate and multifactor analyses were performed to validate different risk factors for cognitive function, respectively in the general population, male older adults and female older adults.

Result

The older adults with cognitive impairment accounted for 10.4% of the total population. There are significant differences in cognitive function between male and female older adults. The odds of cognitive impairment in older adult women was 1.291 times that of older adult men (OR = 1.291, 95%CI: 1.084-1.538). Among the male older adults, those who were older, highly educated, spouseless, had depressive symptoms, and lacked social activities were more likely to have cognitive impairment, whereas among the female older adults, those who were older, highly educated, and lacked social activities were more likely to have cognitive impairment.

Conclusion

Overall, there are subtle differences in potential influencing factors for cognitive function between the male older adults and female older adults. Attention should be paid to the different cognitive protection measures for the older adults with different sexes.

Changes in Plant-based Dietary Quality and Subsequent Risk of Cognitive Impairment among Older Chinese Adults: A National Community-based Cohort Study

BACKGROUND

It is unclear how changes in plant-based dietary quality are linked to subsequent risk of cognitive impairment. This study aims to evaluate this relationship using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

METHODS

A total of 6662 participants free of cognitive impairment in 2008 were included and followed up to 2018. Plant-based dietary quality was assessed by three indices: overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI). Changes in plant-based diet quality from 2008 to 2011 were classified into quintiles. We assessed incident cognitive impairment (from 2011 to 2018) by using the Mini-Mental State Examination (MMSE). Cox proportional-hazards models were performed.

RESULTS

We recorded 1571 incident cases of cognitive impairment during a median of 10 years of follow-up. Compared with participants whose plant-based diet had no change or was relatively stable over three years, the full-adjusted hazard ratios (HRs) with 95% confidence intervals (CI) for cognitive impairment were 0.77 (0.64, 0.93), 0.72 (0.60, 0.86), and 1.50 (1.27, 1.77) among participants with a large increase in PDI, hPDI, and uPDI, respectively. The HRs with 95% CI were 1.22 (1.02, 1.44), 1.30 (1.11, 1.54), and 0.80 (0.67, 0.96) among participants with a large decrease in PDI, hPDI, and uPDI, respectively. Every 10-point increase in PDI and hPDI was associated with 26% and 30% lower risk of cognitive impairment, while every 10-point increase in uPDI was associated with 36% higher risk.

CONCLUSIONS

Older adults with increased adherence to an overall plant-based diet and a healthful plant-based diet over three years have a lower risk of cognitive impairment, while those with increased adherence to an unhealthy plant-based diet had a higher risk of cognitive impairment.

Increased Intake of Vegetables and Fruits Improves Cognitive Function among Chinese Oldest Old: 10-Year Follow-Up Study

BACKGROUND

In view of the rapidly accelerating aging process in China, this study looked at the associations between vegetables and fruits intake pattens and cognitive function among the oldest old in China using the genetic sub study from the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

METHODS

This study screened respondents who participated in all four surveys of longitudinal data from the CLHLS, and a total of 2454 participants were ultimately included. The relationships of cognitive function with vegetables and fruits intake patterns were examined using Generalized-estimating equations.

RESULTS

The prevalence range of mild cognitive impairment (MCI) was 14.3% to 16.9% at T1 to T3 and 32.7% at T4. There was a significant increase in the prevalence of MCI from T1 to T4 (β = 0.054; 95% CI, 0.037 to 0.070; p < 0.001; adjusted). The V+/F+ pattern significantly improved cognitive function in Chinese older adults compared with the V-/F- pattern (OR, 1.026; 95% CI, 1.001-1.053; p < 0.05).

CONCLUSION

Older adults who frequently consume both fruits and vegetables experience a reduction in MCI risk relative to those consuming these food groups infrequently-emphasizing the critical importance of the regular intake of both fruits and vegetables in maintaining cognitive function.

Relationship between socioeconomic status and cognitive ability among Chinese older adults: the moderating role of social support

BACKGROUND

Understanding the causes and pathways of cognitive decline among older populations is of great importance in China. This study aims to examine whether the discrepancy in socioeconomic status (SES) makes a difference to the cognitive ability among Chinese older adults, and to disentangle the moderating role of different types of social support in the process in which SES influences cognition.

METHODS

We utilized a nationally representative sample from the 2018 Chinese Longitudinal Healthy Longevity Survey. A cumulative SES score was constructed to measure the combined effect of different socioeconomic statuses on the cognitive ability of the elderly. We further examined the moderating role of two types of social support, including emotional support, and financial support. Hierarchical regression analysis was applied to test the direct effect of SES on cognitive ability, and to investigate the moderating role of social support on the association of the SES with the dependent variables.

RESULTS

The results showed that the higher SES of older adults was significantly associated with better cognitive ability (β = 0.52, p < 0.001) after controlling for age, sex, marital status, living region, Hukou, health insurance, lifestyle factors, and physical health status. Emotional support and financial support were moderated the relationship between SES score and cognitive ability.

CONCLUSION

Our results reveal the importance of considering social support in buffering the effects of SES and the associated cognitive ability for aging populations. It highlights the importance of narrowing the socioeconomic gap among the elderly. Policymakers should consider promoting social support to improve the cognitive ability among older adults.

Association between cardiopulmonary function, health-related quality of life and cognitive impairment among the older nursing home residents in Shanghai, China

BACKGROUND

This study aimed to examine the association between cardiopulmonary function, health-related quality of life (HRQOL) and cognitive function among nursing home residents aged 80 years and over.

METHODS

A nursing home-based, cross-sectional study was implemented among 677 aged over 80 years in Shanghai, China. A total of 197 participants underwent effective cardiopulmonary function examinations. Mini-Mental Status Examination (MMSE) and Short Form-36 scales (SF-36) were used to assess cognitive function and HRQOL, respectively.

RESULTS

Decline in left ventricular ejection fractions (LVEF) [adjusted odds ratio (AOR), 1.98; 95% confidential interval (CI), 1.03-3.81)] and vital capacity (VC) (AOR, 2.08; 95%CI, 1.07-4.04) was associated with cognitive impairment. After adjusting confounding factors, relationships between cognitive function and physical functioning (PF) (AOR, 0.98; 95%CI, 0.97-0.99) still existed.

CONCLUSIONS

Healthcare professionals should pay more attention to cardiopulmonary health and HRQOL in the nursing home residents. Actions of public health strategies focus on the improvement of cardiopulmonary function, and PF among older nursing home residents with cognitive impairment is required.

Interaction between the animal-based dietary pattern and green space on cognitive function among Chinese older adults: A prospective cohort study

Green space is associated with better cognition, while the animal-based dietary pattern can be a risk factor. We aimed to verify the associations and explore their interaction among the elderly. The China Longitudinal Healthy Longevity Survey (CLHLS) cohort including 17,827 participants was used. The average green space coverage rate was used to measure green space exposure. The animal-based diet index (ADI) was scored based on the non-quantitative frequency questionnaire of ten types of food intake (three types of animal foods and seven types of plant foods). We used the Mini-Mental State Examination (MMSE) to assess cognitive function. The Cox proportional hazard regression was applied to explore the correlations and interactions. In the models, we gradually adjusted for the potential risk factors. Compared with participants living in the area with the lowest green space, those living with the highest were associated with a 20% decrease in the risk of cognitive impairment (hazard ratio (HR): 0.80, 95% CI: 0.73, 0.89). As for ADI, the highest group was related to a 64% increase in the risk of cognitive impairment (HR: 1.64, 95% CI: 1.38, 1.95). The protective effect of the highest green space group on cognitive impairment was more evident among participants with low ADI (HR = 0.72, 95% CI: 0.62, 0.83), compared to those with high ADI. Green space was positively associated with cognition, while the animal-based dietary pattern was a cognitive disadvantage. The animal-based dietary pattern may mitigate the beneficial effects of green space on cognition.

Associations between trajectories of cardiovascular risk factor change and cognitive impairment in Chinese elderly: A nationwide cohort study

Objectives

This study aimed to investigate the relationship between long-term trajectories of changes in cardiovascular risk factors (CVRFs) and the risk of cognitive impairment among Chinese adults over 60 years old.

Methods

Data were obtained from the Chinese Longitudinal Healthy Longevity Survey 2005-2018. Cognitive function was evaluated longitudinally through the Chinese version of the Mini-Mental State Examination (C-MMSE), and cognitive impairment (C-MMSE ≤23) was used as the main outcome variable. The cardiovascular risk factors, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), and body mass index (BMI), were continuously measured in the follow-up duration. The patterns of trajectories of changes in CVRFs were derived from the latent growth mixture model (LGMM). The Cox regression model was used to evaluate the cognitive impairment hazard ratio (HR) across different CVRF trajectories.

Results

A total of 5,164 participants aged ≥60 years with normal cognitive function at baseline were included in the study. After a median follow-up of 8 years, 2,071 participants (40.1%) developed cognitive impairment (C-MMSE ≤ 23). The four-class trajectories of SBP and BMI were obtained by means of LGMM, and the trajectories of DBP, MAP, and PP were grouped into a three-class subgroup. In the final adjusted Cox model, the lowered SBP [adjusted HR (aHR): 1.59; 95% CI: 1.17-2.16], lowered PP (aHR: 2.64; 95% CI: 1.66-4.19), and progressively obese (aHR: 1.28; 95% CI: 1.02-1.62) and stable slim (aHR: 1.13; 95% CI: 1.02-1.25) were associated with the higher risk of cognitive impairment. Low stable DBP (aHR: 0.80; 95% CI: 0.66-0.96) and elevated PP (aHR: 0.76; 95% CI: 0.63-0.92) decreased the risk for cognitive impairment among participants.

Conclusion

Lowered SBP, lowered PP, progressive obesity, and stable slim increased the risk for cognitive impairment in the Chinese elderly. Low stable DBP and elevated PP were protective against cognitive impairment, but more DBP lowering and ≥25 mmHg growth in PP contributed to a higher risk of cognitive impairment. The findings have important implications for preventing cognitive impairment in elder adults based on the long-term trajectories of changes in CVRFs.

Combined associations of vitamin D and cognitive function with all-cause mortality among older adults in Chinese longevity areas: A prospective cohort study

Objectives

While both vitamin D deficiency and cognitive impairment have individually been linked to a greater risk of all-cause mortality, the combined effects of these two different conditions have not previously been explored in this context. We aimed to investigate the combined impact of vitamin D concentration and cognitive impairment on all-cause mortality in older adults.

Methods

The analyzed data were collected from community-dwelling adults ≥65 years of age that were enrolled in the Chinese Longitudinal Healthy Longevity Survey (n = 1,673). The Mini-Mental Status Examination (MMSE) was used to assess cognitive function, while the plasma 25-hydroxyvitamin D [25(OH)D] test was used to assess vitamin D status. The associations between vitamin D concentration, cognitive function, and all-cause mortality were assessed with Cox proportional hazards models. We used restricted cubic splines to examine the dose-response relationship between vitamin D and the risk of all-cause mortality and used joint effect testing to explore interactions between vitamin D concentration and cognitive function.

Results

During a mean (SD) follow-up of 3.8 (1.9) years, 899 (53.7%) deaths occurred. A negative dose-response relationship was observed between 25(OH)D concentration and cognition impairment at baseline, as well as the odds of all-cause mortality during follow-up. Similarly, cognitive impairment was significantly related to all-cause mortality risk (HR 1.81, 95% CI: 1.54 to 2.12). The combined analyses showed positive associations, with the highest mortality risk observed in older adults with both low vitamin D and cognitive impairment (HR 3.04, 95% CI: 2.40 to 3.86). Moreover, the interaction between 25(OH)D concentration and cognitive function was found to be significant in relation to the risk of mortality (p for interaction <0.001).

Conclusion

Lower plasma 25(OH)D and cognitive impairment were, respectively, associated with increased all-cause mortality risks. The 25(OH)D concentration and cognitive impairment exhibited a combined additive effect on all-cause mortality among older Chinese adults.

Aging-related changes in reward-based decision-making depend on punishment frequency: An fMRI study

Introduction

Aging is often accompanied by significant cognitive decline and altered decision making. Previous studies have found that older adults have difficulty in processing reward/risk information, leading to suboptimal decision strategy. However, it is still under investigated about the neural substrates of risky decision-making under ambiguity in aging.

Methods

Using the Iowa Gambling Task, the current study investigated inter-individual differences of risk-taking behaviors in healthy older adults with task-related functional magnetic resonance imaging.

Results

It was found that participants were able to improve their decisions in advantageous decks, but failed to avoid disadvantageous decks during task performance. The task-related activations within multiple brain regions were observed significantly different across the four decks, and showed negative correlations with age in disadvantageous decks but not in advantageous decks. Consistently, age-related whole brain analyses confirmed the negative age-effect on brain activations in disadvantageous decks, especially in high punishment frequency. In addition, the relationship between age and task performance in high punishment frequency was mediated by activation in the frontal subregions such as the middle frontal cortex and superior medial frontal cortex.

Discussion

Our findings shed light on the neural substrates of altered risk-taking behaviors in aging, suggesting a greater sensitivity to high punishment frequency in older adults.

The Triglyceride-Glucose Index Is Associated with Longitudinal Cognitive Decline in a Middle-Aged to Elderly Population: A Cohort Study

BACKGROUND

To examine the effect of the triglyceride-glucose (TyG) index on longitudinal cognitive decline in a healthy middle-aged-to-elderly population.

METHODS

We conducted a population-based longitudinal study. A total of 1774 participants without cognitive impairment were enrolled in the 4-year follow-up. They were divided into four groups according to the quartile of the TyG index. Multivariable-adjusted Cox proportional hazard models were performed to examine the association between the TyG index and cognitive decline. Discrimination tests were used to evaluate the incremental predictive value of the TyG index beyond conventional risk factors.

RESULTS

During the follow-up, compared with those in the bottom quartile group, participants in the top TyG quartile group presented a 51% increase in the risk of cognitive decline (OR 1.51 (95% CI: 1.06-2.14)). As shown by discrimination tests, adding the TyG index into the conventional model resulted in a slight improvement in predicting the risk of cognitive decline (NRI 16.00% (p = 0.004)).

CONCLUSION

This study demonstrated that increasing values of the TyG index were positively associated with the risk of cognitive decline. Monitoring the TyG index may help in the early identification of individuals at high risk of cognitive deterioration.

Cognitive impairment assessed by Mini-Mental State Examination predicts all-cause and CVD mortality in Chinese older adults: A 10-year follow-up study

Objective

Cognitive impairment (CI) has been demonstrated as a useful proxy measure of mortality in Western populations. However, the predictive value of CI in Chinese populations is unknown. We aimed to explore whether CI is independently associated with increased long-term all-cause and cardiovascular disease (CVD) mortality in Chinese older adults and the association of performance in specific MMSE sub-domains to subsequent mortality.

Methods and results

A total of 4,499 older adults [mean (SD) age, 70.3(6.7) years] who received a sample investigation from 2011 to 2014 were followed up till 2021 for mortality. The Mini-Mental State Examination was used to assess cognitive function, and Cox's proportional hazard models were used to evaluate the effects of cognitive function on the risk of all-cause and CVD mortality. Demographic characteristics, lifestyle, and health status were included as covariates. During a 10-year follow-up, a total of 667 (14.8%) died. In the fully adjusted model, compared with cognitively normal participants with CI had a 1.33-fold [HR, 1.33; (95% CI, 1.10-1.61)] greater risk of all-cause mortality and a 1.45-fold [HR, 1.45; (95% CIs, 1.11-1.92)] greater risk of CVD mortality. After a similar multivariable adjustment, a per-SD increase in MMSE scores was associated with a reduced risk of all-cause mortality [HR, 0.85; (95% CI, 0.78-0.93)] and CVD mortality [HR, 0.74; (95% CI, 0.65-0.84)]. In the unadjusted model, MMSE sub-domains (apart from immediate recall) were associated with mortality. But only orientation and calculation and attention were still independently associated with all-cause and CVD mortality in a multivariable model.

Conclusion

These findings confirmed that CI is a marker of all-cause and CVD mortality risk in Chinese older adults, independently of other commonly assessed risk factors, and some sub-domains of the MMSE may have stronger associations with mortality. Further research is needed to identify the mechanisms underlying the observed associations.

Association of leisure activity changes and reversion from mild cognitive impairment to normal cognitive function among older adults: A prospective cohort study

Background

Older adults with mild cognitive impairment (MCI) have the possibility of reverting to normal cognitive function. Leisure activity engagement (LAE) plays a critical role in the progress of the cognitive function. A better understanding of the dynamic relationship between LAE and MCI reversion would inform the implementation of preclinical dementia interventions. This study aimed to investigate the association between change patterns of LAE and MCI reversion among older adults using the Chinese Longitudinal Healthy Longevity Survey (CLHLS) database.

Study design

Longitudinal population-based study.

Methods

Older adults with MCI at the baseline were enrolled in this study. Information about cognitive function, overall, cognitively stimulating, physically active/demanding, and socially engaged LAE was collected at baseline and follow-up. Adjusted hazard ratios (HRs) for reversion and 95% confidence intervals (CIs) were calculated by Cox hazard models with time as the underlying time metric. We also assessed potential effect modifications by creating a cross-product of the stratifying variable with LAE change patterns in the fully adjusted model.

Results

The restricted cubic spline showed that the association between LAE change scores and MCI reversion rate was statistically significant and nonlinear (p<0.01). Taking participants in the low-low group as a reference, participants in the low-medium, low-high, medium-medium, medium-high, high-medium, and high-high groups had increased possibilities of MCI reversion with HRs (95% CI) of 2.19 (1.57-3.06), 2.97 (2.13-4.13), 0.87 (0.64-1.19), 2.28 (1.71-3.03), 2.78 (2.10-3.69), 1.93 (1.43-2.59), and 2.74 (2.09-3.60), respectively. Further stratified models showed that the impact of LAE change patterns on MCI reversion varied in different ages (nonagenarian, octogenarian, and younger elderly) and gender.

Conclusions

Participants who maintained the highest LAE had the greatest possibility of MCI reversion. Meanwhile, a higher level of LAE maintenance was associated with the increased possibility of MCI reversion. These results provide a practical message to older adults about how dynamic changes in LAE are associated with improved cognitive function.

Turning Point of Cognitive Decline for Chinese Older Adults from a Longitudinal Analysis: Protective Factors and Risk Factors

OBJECTIVES

To explore the turning point of cognitive decline in Chinese older adults and to explore the influencing factors including covariates.

PARTICIPANTS

Aged 65 and older whose cognitive function was normal at their first test.

METHODS

a secondary analysis that identified participants from the database of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Cohort-sequential design was used to categorize the data by age (rather than study wave), including the follow-up data of Chinese older adults aged 65-79 years and spanning 14 years. Cognitive function in 1278 participants was assessed using the Chinese Mini-Mental State Examination (CMMSE) in five waves over 14 years. Piecewise latent growth curve modeling was used to analyze the data.

RESULTS

(1) The turning point of cognitive decline in Chinese older adults occurs between the ages of 68 and 70. (2) There are statistically significant individual differences in the initial level of cognitive function and the growth rate of cognitive function before and after the transition stage. (3) Factors influencing cognitive function include residence, education level, smoking, drinking, exercise, leisure activities, social activities, Activities of Daily Living (ADL), and Instrumental Activities for Daily Living (IADL). (4) Exercise and ADL are the main protective factors, while smoking and drinking are the main risk factors.

CONCLUSIONS

There is a transition stage (68-70) in the decline of cognitive function in Chinese older adults and four main factors (such as smoking, drinking, exercise and ADL) have impacts on the cognitive decline. We should strengthen these protective factors (exercise and ADL) for the cognitive decline of older adults and avoid these risk factors (smoking, drinking). To prevent the decline of the cognitive function of older adults, the government should build more places conducive to activities for older adults and actively encourage older adults to improve their physical activity level. Given our findings, public health interventions centered on alcohol and tobacco cessation in older adults should be governmentally endorsed.

Adherence to High Dietary Diversity and Incident Cognitive Impairment for the Oldest-Old: A Community-Based, Nationwide Cohort Study

BACKGROUND AND AIMS

Dietary diversity change is associated with cognitive function, however, whether the effect still exists among the oldest-old (80+) is unclear. Our aim was to examine the effect of dietary diversity changes on cognitive impairment for the oldest-old in a large prospective cohort.

METHODS

Within the Chinese Longitudinal Healthy Longevity Study, 6237 adults older than 80 years were included. The dietary diversity score (DDS) was assessed by a simplified food frequency questionnaire (FFQ). Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score lower than 18 points. Cognitive decline was defined as a reduction of total MMSE score ≥3 points, and cognitive decline of different subdomains was defined as a reduction of ≥15% in the corresponding cognitive domain. The multivariate-adjusted Cox proportional hazard model evaluated the effects of DDS change on cognitive decline. The linear mixed-effect model was used to test subsequent changes in MMSE over the years.

RESULTS

During 32,813 person-years of follow-up, 1829 participants developed cognitive impairment. Relative to the high-high DDS change pattern, participants in the low-low and high-low patterns were associated with an increased risk of cognitive impairment with a hazard ratio (95% confidential interval, CI) of 1.43 (1.25, 1.63) and 1.44 (1.24, 1.67), and a faster decline in the MMSE score over the follow-up year. Participants with the low-high pattern had a similar incidence of cognitive impairment with HRs (95% CI) of 1.03 (0.88, 1.20). Compared with the stable DDS status group (-1-1), the risk of cognitive impairment was higher for those with large declines in DDS (≤-5) and the HR was 1.70 (95% CI: 1.44, 2.01).

CONCLUSIONS

Even for people older than 80, dietary diversity change is a simple method to identify those who had a high risk of cognitive decline. Keeping high dietary diversity is beneficial for cognitive function and its subdomain even in the final phase of life, especially for females and the illiterate oldest-old.

Exploring the association between cognitive decline and all-cause mortality with blood pressure as a potential modifier in oldest old individuals

Few studies have systematically explored the association between cognitive decline and all-cause mortality among oldest old individuals (above 80 years old), and there is limited evidence of blood pressure (BP) as a potential effect modifier. Therefore, this study included 14,891 oldest old individuals (mean age: 90.3 ± 7.5 years); 10,904 deaths and 34,486 person-years were observed. Cognitive scores were calculated using the Chinese version of the Mini-Mental State Examination (MMSE). Cognitive decline was stratified into ten categories (C0-C9). Continuous cognitive scores were used to assess the interactions of modifiers of the cognitive decline and all-cause mortality association and potentially modifiable factors. Potential effect modifiers were explored by age, sex, BP status and hypertension. Cox proportional hazards models were used to evaluate the relationship between cognitive decline and all-cause mortality after adjustments for demographic characteristics, socioeconomic status, lifestyle factors, leisure activities and health conditions. Participants who progressed to severe cognitive impairment from high normal cognitive function (C3), low normal cognitive function (C6), or mild cognitive impairment (C8) had 55%, 56%, and 63% higher mortality risks, respectively, than those who maintained high normal cognitive function (C0). The multivariate-adjusted model indicated that oldest old individuals with a decrease of more than one point in the MMSE score per year had an approximately 4% all-cause mortality risk. The relationship between cognitive decline and mortality was statistically influenced by sex (P = 0.013), high BP in nonagenarians (P = 0.003), and hypertension (P = 0.004) but not by age (P = 0.277). Our findings suggest that periodic screening for cognitive decline and strengthening BP management may be necessary for public health.

Associations Between Cognitive Functioning and Mortality in a Population-Based Sample of Older United States Adults: Differences by Sex and Education

Objective: To determine whether cognition is associated with mortality among older US adults. Methods: We studied 5,989 National Health and Nutrition Examination Survey participants age 60+ in years 1999-2014 with mortality follow-up through 2015. Cognitive function was measured in one standard deviation decrements using the Digit Symbol Substitution Test (DSST), Animal Fluency (AnFl), and two Consortium to Establish a Registry for Alzheimer's Disease (CERAD) tests. Results: Each decrement in cognitive function was associated with increased risk of mortality overall (DSST HR: 1.36, 95% CI: 1.25, 1.48), among women only (AnFl: 1.51, 95% CI: 1.02, 2.24), and among those with less than a high school education only (AnFl HR: 1.46, 95% CI: 1.09, 1.97; CERAD-WL HR: 1.34, 95% CI: 1.07, 1.67; and CERAD-DR HR: 1.38, 95% CI: 1.05, 1.82). Discussion: Among US adults, lower cognitive functioning was associated with mortality; associations were stronger among women and those with less education.

Community support and promoting cognitive function for the elderly

Proper cognitive functions are critical to the life of the elderly. With the rapid aging of the population, community support plays an important role in cognitive functioning. This study examines the association between community support and the level of cognitive functioning in the elderly, and the mediating effect of social participation in the relationship. Based on the panel data of China Longitudinal Healthy Longevity Survey (CLHLS) in 2005, 2008, 2011, 2014, and 2018, people aged 65 and over are selected as the research object (N = 35,479). The panel Logit model is used to analyze the influence of community support on their cognitive functioning. In addition, the stepwise regression and KHB decomposition methods are used to test the influence mechanism of community support on their cognitive function. The benchmark regression results show that there is a significant correlation between community support and cognitive function in the elderly (OR: 1.64, 95% CI: 1.41–1.91, p &lt; 0.01). Daily care (OR: 1.75, 95% CI: 1.33–2.29, p &lt; 0.01) has the strongest impact on the cognitive function of the elderly, followed by health care (OR: 1.70, 95% CI: 1.43–2.01, p &lt; 0.01) and legal support (OR: 1.64, 95% CI: 1.37–1.95, p &lt; 0.01), while psychological care (OR: 1.62, 95% CI: 1.31–2.01, p &lt; 0.01) has the weakest impact on the cognitive function of the elderly. The results of the mediation effect test show that social participation plays a significant intermediary role in the impact of community support on the cognitive function of the elderly (mediation percentage: 16.89%), demonstrating that community support can improve the cognitive function of the elderly by promoting the social participation of the elderly. In classified community support, social participation plays a significant intermediary role in the impact of psychological care on cognition (mediation percentage: 46.10%).

The effects of loneliness, social isolation, and associated gender differences on the risk of developing cognitive impairment for Chinese oldest old

OBJECTIVES

To investigate whether loneliness and social isolation could independently predict subsequent risk of cognitive impairment in Chinese oldest old, and to examine possible gender differences.

METHODS

The sample included 2,732 older adults aged 80 years and above with intact cognitive function from the Chinese Longitudinal Healthy Longevity Survey 2002-2018 waves, with an average follow-up of 4.24 years. Loneliness was measured by a single-item question about how often the participant felt lonely. Social isolation was defined by marital status, frequent visits by family members, and social activity engagement. Cognitive impairment was defined based on Mini-Mental State Examination scores.

RESULTS

Cox regression showed that social isolation independently predicted a higher risk of developing cognitive impairment at follow-up (HR = 1.14, 95% CI [1.03, 1.27], p = 0.014). Importantly, although there was no main effect of loneliness, a significant interaction between gender and loneliness (p = 0.013) suggested that increased loneliness was associated with a higher risk of developing cognitive impairment for men but not for women.

CONCLUSION

To prevent cognitive impairment and promote healthy longevity, socially isolated adults in their oldest old age should receive more attention, and men who often feel lonely should be offered with more emotional support.

Effect of cognitive impairment on risk of death in Hispanic/Latino adults over the age of 50 residing in the United States with and without diabetes: Data from the Health and Retirement Study 1995-2014

OBJECTIVE

To understand the relationship between mortality and cognitive function among older US Hispanic adults with and without diabetes.

METHODS

Data from the Health and Retirement Study (1995-2014) were analyzed. Cox proportional hazard models were used to estimate the association between mortality and cognitive function. Models were stratified by diabetes.

RESULTS

Four thousand thirteen older US Hispanic adults were included. Fully adjusted models for individuals with diabetes showed those with mild cognitive impairment (MCI; hazard ratio [HR]: 1.61; 95% confidence interval [CI]: 1.06, 2.45; P = .025) and dementia (HR: 2.14; 95% CI: 1.25, 3.67; P = .006) had increased mortality compared to normal cognition. Fully adjusted models for individuals without diabetes showed those with MCI (HR: 1.87; 95% CI: 1.28, 2.74; P = .001) and dementia (HR: 3.25; 95% CI: 1.91, 5.55; P < .001) had increased mortality compared to normal cognition.

CONCLUSIONS

Cognitive impairment is associated with increased mortality in older US Hispanic adults with and without diabetes. Clinicians should regularly assess cognitive function in this group to quickly identify declines and make appropriate referrals for support to optimize health and reduce mortality.

The association between cognitive impairment and 30-day mortality among older Chinese inpatients

Purpose

Although the association between cognitive impairment and mortality has been widely described among community-dwelling older adults, this association in hospitalized patients was limited.

Objectives

This study's purpose was to explore the association between cognitive impairment and 30-day mortality after adjustment of factors among Chinese in-patients.

Methods

This was a large-scale prospective study based on a cohort of patients aged 65 years and older, whose cognitive function was assessed using the Mini-Cog instrument, followed up at 30-days for mortality. Multivariate logistic regression models were used to assess the association between cognitive impairment and 30-day mortality.

Results

There were 9,194 inpatients in our study, with an average age of 72.41 ± 5.72. The prevalence of cognitive impairment using the Mini-Cog instrument was 20.5%. Multivariable analyses showed that patients with cognitive impairment have an increased risk of 30-day mortality, compared to those with normal cognitive function (OR = 2.83,95%CI:1.89–4.24) in an unadjusted model. In the fully adjusted model, Patients with cognitive impairment had an increased risk of 30-day mortality compared to those with normal cognitive function in the completely adjusted model (OR = 1.76,95% CI: 1.14–2.73). Additionally, this association still existed and was robust after performing a stratified analysis of age, gender, frailty and depression, with no significant interaction (P > 0.05).

Conclusions

Our study found that older Chinese in-patients with cognitive impairment have a 1.76-fold risk of 30-day mortality compared to patients with normal cognitive function, suggesting that clinicians and nurses need to early implement cognitive function screening and corresponding interventions to improve clinical outcomes for older in-patients.

Using machine learning algorithms for predicting cognitive impairment and identifying modifiable factors among Chinese elderly people

Objectives: This study firstly aimed to explore predicting cognitive impairment at an early stage using a large population-based longitudinal survey of elderly Chinese people. The second aim was to identify reversible factors which may help slow the rate of decline in cognitive function over 3 years in the community. Methods: We included 12,280 elderly people from four waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), followed from 2002 to 2014. The Chinese version of the Mini-Mental State Examination (MMSE) was used to examine cognitive function. Six machine learning algorithms (including a neural network model) and an ensemble method were trained on data split 2/3 for training and 1/3 testing. Parameters were explored in training data using 3-fold cross-validation and models were evaluated in test data. The model performance was measured by area-under-curve (AUC), sensitivity, and specificity. In addition, due to its better interpretability, logistic regression (LR) was used to assess the association of life behavior and its change with cognitive impairment after 3 years. Results: Support vector machine and multi-layer perceptron were found to be the best performing algorithms with AUC of 0.8267 and 0.8256, respectively. Fusing the results of all six single models further improves the AUC to 0.8269. Playing more Mahjong or cards (OR = 0.49,95% CI: 0.38-0.64), doing more garden works (OR = 0.54,95% CI: 0.43-0.68), watching TV or listening to the radio more (OR = 0.67,95% CI: 0.59-0.77) were associated with decreased risk of cognitive impairment after 3 years. Conclusions: Machine learning algorithms especially the SVM, and the ensemble model can be leveraged to identify the elderly at risk of cognitive impairment. Doing more leisure activities, doing more gardening work, and engaging in more activities combined were associated with decreased risk of cognitive impairment.

Excessive sleep increased the risk of incidence of cognitive impairment among older Chinese adults: a cohort study based on the Chinese Longitudinal Healthy Longevity Survey (CLHLS)

STUDY OBJECTIVES

Based on a cohort from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), we aimed to evaluate the relationship between sleep duration and the incidence of cognitive impairment among older Chinese adults.

METHODS

We conducted a prospective analysis based on 3692 participants from the CLHLS at baseline (in 2011), and as a 3-year follow-up (till 2014), 531 participants (14.4%) had cognitive impairment, which was defined as a Mini-Mental State Examination score <24. Sleep duration was classified into three groups: short (≤5 hours/day), normal (>5 but <10 hours), and long (≥10 hours/day). A logistic regression model was used to examine the association between baseline sleep duration and cognitive impairment after adjusting for sociodemographic data, living habits, and health conditions.

RESULTS

Five hundred sixty-two participants (15.2%) were in the short-duration group, and 608 participants (16.5%) were in the long-duration group. After adjusting for multiple potential confounders, compared with normal sleep duration, long sleep duration was associated with the incidence of cognitive impairment (OR = 1.309, 95% CI: 1.019-1.683), especially among men (OR = 1.527, 95% CI: 1.041-2.240) and those having a primary and above education level (OR = 1.559, 95% CI: 1.029-2.361). No significant association was observed between short sleep duration and cognitive impairment (OR = 0.860, 95% CI: 0.646-1.145).

CONCLUSIONS

Excessive sleep may increase the risk of cognitive impairment in older individuals. It may be a suggestive sign of early neurodegeneration and may be a useful clinical tool to identify those at a higher risk of progressing to cognitive impairment.

Hearing Impairment With Cognitive Decline Increases All-Cause Mortality Risk in Chinese Adults Aged 65 Years or Older: A Population-Based Longitudinal Study

Background

Hearing impairment (HI), a highly prevalent sensory impairment affecting older adults, is a risk factor for cognitive decline. However, few studies examined the association between HI and all-cause mortality, and the role of different cognitive states on this relationship in Chinese older adults is poorly understood.

Methods

A total of 10,744 Chinese older adults aged 65 years or older were included in the 2011/2012 and 2014 cohorts from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), with the longest follow-up period lasting for up to 8 years. The presence of HI was identified by using a dichotomized metric of self-reported hearing status. All-cause mortality data were ascertained from interviews with family members or relatives of the participants. Cognitive function was evaluated by employing the modified Mini-Mental State Examination (MMSE), which consisted of seven subdomains (orientation, naming foods, registration, attention and calculation, copy figure, delayed recall, and speech and language). Kaplan–Meier survival curves were constructed to evaluate the different hearing states on overall survival. The risk of mortality over the follow-up period was estimated by using Cox proportional hazard ratios (HRs) models.

Results

A conspicuous probability was revealed in the survival relationship between hearing status and all-cause mortality for the total population (p < 0.001). Participants with HI had a higher risk of all-cause mortality (HR = 2.29, 95% CI: 2.16, 2.42), as compared with their counterparts without HI. The association was robust upon fully adjustment for potential confounders (HR = 1.07, 95% CI: 1.00, 1.14). Compared to HI participants with no cognitive impairment, HI patients with cognitive impairment had a higher mortality risk (HR = 2.31, 95% CI: 2.13, 2.51). Impairment in the subdomains of cognitive function were independently associated with elevated mortality risk in the participants with HI, with an HR ranging from 1.28 (copy figure) to 1.46 (speech and language).

Conclusions

Cognitive decline was common in individuals with HI, and those with HI and cognitive impairment further increased mortality risk. Our findings prompt a call for actions to improve the hearing status and cognitive function of older people to minimize health risks and improve longevity.

Relationships of leisure activities with physical and cognitive functions among Chinese older adults: A prospective community-based cohort study

OBJECTIVES

Based on a prospective design, this study aimed to investigate the relationships of leisure activities with physical and cognitive functions among Chinese older adults.

METHODS

The respondents aged 65 years or more were selected from the 2014-2018 of the Chinese Longitudinal Healthy Longevity Survey. Physical function measurement indicators were reflected by activities of daily living (ADL), instrumental activities of daily living (IADL), and physical performance (PP), while cognitive function was assessed by Mini-Mental State Examination. Fine-Gray competing risk regression models were used to analyze the data.

RESULTS

Using the figures for 2014 as a baseline for the study, we included 6047, 6216, 5951, and 5916 respondents in the ADL, IADL, PP, and cognitive function analyses, respectively. The prospective results showed that keeping domestic animals or pets was related to a lower risk of ADL disability of respondents after adjustment (SHR: 0.619, 95% CI: 0.486, 0.788). Similarly, taking part in social activities (SHR: 0.781, 95%CI: 0.658, 0.929) and reading books or newspapers (SHR: 0.793, 95% CI: 0.656, 0.958) were associated with a lower risk of IADL disability. Playing cards or mahjong was correlated with a lower risk of cognitive impairment (SHR: 0.669, 95% CI: 0.507, 0.882), while keeping domestic animals or pets was related to a higher risk of cognitive impairment (SHR: 1.279, 95% CI: 1.047, 1.562).

CONCLUSION

Participation in leisure activities moderately may decrease the risk of a decline in physical and cognitive functions among Chinese older adults.

Association of waist-calf circumference ratio with incident cognitive impairment in older adults

BACKGROUND

The longitudinal relation of central fat and muscle mass with cognitive function remains unclear.

OBJECTIVES

We aimed to evaluate the relation of anthropometric measures, including BMI, waist circumference (WC), calf circumference (CC), and waist-calf circumference ratio (WCR), with incident cognitive impairment in older adults.

METHODS

A total of 3312 participants aged ≥65 y (mean: 81.8 y) who were free of cognitive impairment [the Chinese version of the Mini-Mental State Examination (MMSE) scores ≥24 points] in the Chinese Longitudinal Healthy Longevity Survey were included. The primary outcome was incident cognitive impairment, defined as MMSE scores <24 points at the exit visit. Secondary outcomes were incident cognitive decline, defined as a reduction of MMSE scores ≥3 points at the exit visit, and incident decline in different cognitive domains, defined as a reduction of MMSE scores in the domain ≥15% at the exit visit.

RESULTS

During a median follow-up duration of 3.6 y, 565 (17.1%) participants developed incident cognitive impairment. Overall, with mutual adjustments, higher WC [≥89 cm (fourth quartile) compared with <75 cm (first quartile); adjusted HR: 1.56; 95% CI: 1.19, 2.04] and higher WCR [≥2.9 (fourth quartile) compared with <2.4 (first quartile); adjusted HR: 1.96; 95% CI: 1.52, 2.52] were significantly associated with a higher risk of cognitive impairment, and higher CC [≥34 cm (fourth quartile) compared with <28 cm (first quartile); adjusted HR: 0.44; 95% CI: 0.33, 0.59] was associated with a lower hazard of cognitive impairment. Similar results were found for the secondary outcomes. However, BMI was not significantly associated with the study outcomes.

CONCLUSIONS

High WC and low CC were significantly associated with higher incident cognitive impairment in older adults. Moreover, WCR had a relatively stronger association with cognitive impairment compared with each circumference, suggesting maintaining both higher lean mass and lower central fat in older adults for the prevention of cognitive impairment.