Longitudinal trajectories of physical functioning among Chinese older adults: the role of depressive symptoms, cognitive functioning and subjective memory

Frailty, cognitive impairment, and depressive symptoms in Chinese older adults: an eight-year multi-trajectory analysis

BACKGROUND

Frailty, cognitive impairment, and depressive symptoms are closely interrelated conditions in the aging population. However, limited research has longitudinally analyzed the concurrent trajectories of these three prominent conditions in older adults in China. This study aimed to explore the eight-year trajectories of frailty, cognitive impairment, and depressive symptoms, and to identify individual-level and structural-level factors associated with the trajectories.

METHODS

Four waves of data from the China Health and Retirement Longitudinal Study (2011-2018) were used to identify 6,106 eligible older adults. The main measures included frailty by the frailty index constructed using 30 indicators, cognitive impairment by the summary score of immediate and delayed word recall, figure drawing, serial subtraction, and orientation, and depressive symptoms by the Center for Epidemiologic Studies Depression Scale. Multi-trajectory models identified the trajectories of frailty, cognitive impairment, and depressive symptoms over time. Multinomial logistic regression was employed to estimate the associations between individual-level capital factors and one structural factor (hukou and geographic residency) with the identified trajectories, adjusting for demographic characteristics.

RESULTS

Four trajectories emerged: (1) worsening frailty, worsening cognitive impairment, depression (14.0%); (2) declining pre-frailty, declining cognition, borderline depression (20.0%); (3) pre-frailty, worsening cognitive impairment, no depression (29.3%); and (4) physically robust, declining cognition, no depression (36.7%). Using the "physically robust, declining cognition, no depression" as the reference, not working, no social activity participant, worse childhood family financial situation, and poorer adult health were most strongly associated with the "worsening frailty, worsening cognitive impairment, depression" trajectory; worse health during childhood had the highest association with the "declining pre-frailty, declining cognition, borderline depression" trajectory; less education, lower household consumption, and rural hukou had the greatest association with the increased likelihood of the "pre-frailty, worsening cognitive impairment, no depression" trajectory.

CONCLUSIONS

Findings could inform the understanding of the interrelationship of frailty, cognitive impairment, and depressive symptoms in older adults in China and may help practitioners detect adults at risk for adverse trajectories to implement strategies for proper care.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Changes in Physical Performance among Community-Dwelling Older Adults in Six Years

Changes in physical performance (PP) occur with aging, and understanding the magnitude of these changes over time is important. This study evaluated changes in Gait Speed (GS) and Timed Up and Go (TUG) performance and their association with related factors among community-dwelling older adults over a period of five to six years. A cohort study of 476 older adults with baseline assessment conducted in 2014 and reassessment in 2019-2020 was carried out. Associations between PP changes over time and sociodemographic, behavioral, and health variables were evaluated using mixed linear models. Approximately 68% of the participants declined PP; 20% had no relevant change in GS and 9% in TUG time (sustained PP); 12% increased GS, and 23% decreased TUG time (improved PP). Being male (p = 0.023), living without a partner/separated (p = 0.035), higher education (p = 0.019), and alcohol consumption in the prior month (p = 0.045) were associated with decreased GS, while older age (p < 0.001), having lower socioeconomic status (p < 0.004), physical inactivity (p = 0.017), and being overweight (p = 0.007) were associated with increased TUG time. PP declined for most participants. Factors most strongly associated with PP decline are non-modifiable. The high prevalence of PP decline over time signals the importance of including physical tests in yearly health assessments.

Longitudinal trajectories of depressive symptoms: the role of multimorbidity, mobility and subjective memory

BACKGROUND

The high prevalence of depression among older people in China places a heavy burden on the health system. Multimorbidity, mobility limitation and subjective memory impairment are found to be risk indicators for depression. However, most studies on this topic focused on depression at a single point in time, ignoring the dynamic changes in depressive symptoms and the relationship between the trajectories and these three conditions. Therefore, we aimed to identify distinct trajectories of depressive symptoms in older people and investigate their associations with multimorbidity, mobility limitation and subjective memory impairment.

METHODS

Data was drawn from China Health and Retirement Longitudinal Study conducted during 2011-2018. A total of 5196 participants who completed 4 visits, conducted every 2-3 years were included in this study. Group-based trajectory modeling was conducted to identify distinct trajectories of depressive symptoms z-scores. Multinomial logistic regression was used to investigate the relationships.

RESULTS

Four distinct trajectories of depressive symptoms z-scores were identified, labeled as persistently low symptoms (68.69%, n = 3569), increasing symptoms (12.14%, n = 631), decreasing symptoms (14.05%, n = 730) and persistently high symptoms (5.12%, n = 266). Participants with multimorbidity had unfavorable trajectories of depressive symptoms compared with those without multimorbidity, with adjusted odds ratios (95% CIs) of 1.40 (1.15, 1.70), 1.59 (1.33, 1.90) and 2.19 (1.65, 2.90) for the increasing symptoms, decreasing symptoms and persistently high symptoms, respectively. We also observed a similar trend among participants with mobility limitations. Compared with participants who had poor subjective memory, participants with excellent/very good/good subjective memory had a lower risk of developing unfavorable trajectories of depressive symptoms. The adjusted odds ratios (95% CIs) of the increasing symptoms, decreasing symptoms and persistently high symptoms were 0.54 (0.40, 0.72), 0.50 (0.38, 0.65) and 0.48 (0.31, 0.73), respectively.

CONCLUSIONS

Multimorbidity, mobility limitation and subjective memory impairment were found to be potential risk factors for unfavorable depression trajectories.

The combined associations of depression and cognitive impairment with functional disability and mortality in older adults: a population-based study from the NHANES 2011-2014

Objective

The present study aimed to explore the combined associations of depression and cognitive impairment with functional disability and mortality, and whether the joint effects of depression and cognitive impairment on mortality were influenced by functional disability.

Methods

A total of 2,345 participants aged 60 and above from the 2011-2014 cycle of the National Health and Nutrition Examination Survey (NHANES) were included in the analyses. Questionnaires were used to evaluated depression, global cognitive function and functional disability (including disability in activities of daily living (ADLs), instrumental activities of daily living (IADLs), leisure and social activities (LSA), lower extremity mobility (LEM), and general physical activity (GPA)). Mortality status was ascertained up to December 31, 2019. Multivariable logistic regression was performed to investigate the associations of depression and low global cognition with functional disability. Cox proportional hazards regression models were conducted to evaluate the effect of depression and low global cognition on mortality.

Results

Interactions between depression and low global cognition were observed when exploring associations of depression and low global cognition with IADLs disability, LEM disability, and cardiovascular mortality. Compared with normal participants, participants with both depression and low global cognition had the highest odds ratios of disability in ADLs, IADLs, LSA, LEM, and GPA. Besides, participants with both depression and low global cognition also had the highest hazard ratios of all-cause mortality and cardiovascular mortality, and these associations remained after adjusting for disability in ADLs, IADLs, LSA, LEM, and GPA.

Conclusion

Older adults with both depression and low global cognition were more likely to have functional disability, and had the highest risk of all-cause mortality and cardiovascular mortality.

Impact of physical activity intensity on longitudinal trajectories of cognitive function and depressive symptoms in middle-aged and older Chinese adults: Eight-year prospective study

BACKGROUND

Little is known about how longitudinal trajectories of cognitive function and depressive symptoms are impacted by varying levels of physical activity (PA) intensity.

METHOD

The data were from the China Health and Retirement Longitudinal Study, a nationally representative household study of the Chinese population aged 45 years and older. The sample included 5025 middle-aged and older adults (mean age = 57) who self-reported their cognitive function, depressive symptoms, and PA intensity (vigorous PA, moderate PA, and light PA) every two years from 2011 to 2018.

RESULT

On average, every 2 years, cognitive function decreased by 0.17 points (95 % CI: [-0.22, -0.12], P < 0.05), while depressive symptoms increased by 0.23 points (95 % CI: [0.19,0.27], P < 0.001). Middle-aged and older adults who reported a minimum of 6 days/week frequency of moderate PA (β = 0.14, 95 % CI:[0.01,0.27]) had lower reduction of cognitive function compared to people with none moderate PA but not vigorous PA (β = 0.04, 95 % CI:[-0.11,0.19]) and light PA (β = 0.06, 95 % CI:[-0.09,0.22]). The increase in depressive symptoms was significantly slower among middle-aged and older adults with a minimum of 6 days/week light PA (β = -0.02, 95 % CI:[-0.03,-0.002]).

CONCLUSION

A minimum of 6 days of moderate PA a week was associated with a slower reduction in cognitive function and a minimum of 6 days of light PA a week was linked to a delayed increase in depressive symptoms. In middle-aged and older adults, a tailored PA intensity may be more beneficial in achieving the maximum improvement in cognitive function and mental health.

The Influence of Alcohol Consumption, Depressive Symptoms and Sleep Duration on Cognition: Results from the China Health and Retirement Longitudinal Study

AIM

Healthy cognition-related factors include alcohol consumption, depressive symptoms, and sleep duration. However, less is known about the role of these factors in the dyad or tripartite relationships. In this study, we examined whether there were potential mediation effects, moderation effects, and interactions between these factors in the longitudinal study.

METHODS

Both cross-sectional data analysis and a longitudinal study were performed using baseline and 2018 data from the China Health and Retirement Longitudinal Study (CHARLS) cohort. CHARLS is a nationwide survey program covering 450 villages and 150 counties in 28 provinces that aims to investigate comprehensive demographic information. After selecting participants from the CHARLS cohort, 15,414 were included in the study. Non-drinkers, those who drink more than once a month, and those who drink less than once a month were defined by their alcohol consumption. Depressive symptoms were defined as nondepressed (less than or equal to 12) and depressed (more than 12). Sleep duration was defined as 7-8 h per night, ≤6 h per night, and ≥9 h per night. The total cognitive scores were calculated from memory, orientation, and executive tests. The PROCESS macro in SPSS was used to analyze all mediations and moderating mediations.

RESULTS

Alcohol consumption has a positive correlation with cognition. The global cognition z scores of participants with depressive symptoms were significantly lower than those of the control (all p's < 0.001), in different models. The memory score (β: -0.148; 95% CI: -0.240 to -0.056; p = 0.002), the executive score (β: -0.082; 95% CI: -0.157 to -0.006; p = 0.033), and the global cognition score (β: -0.105; 95% CI: -0.187 to -0.023; p = 0.012) of participants defined as ≤6 h per night were, obviously, less than the control (7-8 h per night). An association between depression and alcohol consumption has been found, and the protective effects have been reversed by depression, which caused the cognition decline. Sleep duration was identified as a moderator, influencing the relationship between depressive symptoms and cognitive function. Besides, there was an interaction causing cognition decline among alcohol consumption, depressive symptoms, and sleep duration. Cognitive function showed a marked downward trend with increasing age.

CONCLUSIONS

In this model, depression primarily mediates the relationship between alcohol consumption and cognition, and sleep duration changes the mediation effect. Furthermore, there is a significant interaction between alcohol consumption, depressive symptoms, and sleep duration, which are significantly associated with cognitive function.