Physical activity and cognitive functioning in the oldest old: within- and between-person cognitive activity and psychosocial mediators

The current study examines the role of social contact intensity, cognitive activity, and depressive symptoms as within- and between-person mediators for the relationships between physical activity and cognitive functioning. All three types of mediators were considered simultaneously using multilevel structural equations modeling with longitudinal data. The sample consisted of 470 adults ranging from 79.37 to 97.92 years of age (M = 83.4; SD = 3.2) at the first occasion. Between-person differences in cognitive activity mediated the relationship between physical activity and cognitive functioning, such that individuals who participated in more physical activities, on average, engaged in more cognitive activities and, in turn, showed better cognitive functioning. Mediation of between-person associations between physical activity and memory through social contact intensity was also significant. At the within-person level, only cognitive activity mediated the relationship between physical activity and change in cognition; however, the indirect effect was small. Depressive symptomatology was not found to significantly mediate within- or between-person effects on cognitive change. Our findings highlight the implications of physical activity participation for the prevention of cognitive decline and the importance of meditational processes at the between-person level. Physical activity can provide older adults with an avenue to make new friendships and engage in more cognitive activities which, in turn, attenuates cognitive decline.     

Between-Person and Within-Person Associations Among Processing Speed,Attention Switching,and Working Memory in Younger and Older Adults

Background/Study Context: Theories of cognitive aging predict associations among processes that transpire within individuals, but are often tested by examining between-person relationships. The authors provide an empirical demonstration of how associations among measures of processing speed, attention switching, and working memory are different when considered between persons versus within persons over time.

Methods: A sample of 108 older adults (M _age = 80.8, range = 66–95) and 68 younger adults (M _age = 20.2, range = 18–24) completed measures of processing speed, attention switching, and working memory on six occasions over a 14-day period. Multilevel modeling was used to examine processing speed and attention switching performance as predictors of working memory performance simultaneously across days (within-person) and across individuals (between-person).

Results: The findings indicates that simple comparison and response speed predicted working memory better than attention switching between persons, whereas attention switching predicted working memory better than simple comparison and response speed within persons over time. Furthermore, the authors did not observe strong evidence of age differences in these associations either within or between persons.

Conclusion: The findings of the current study suggest that processing speed is important for understanding between-person and age-related differences in working memory, whereas attention switching is more important for understanding within-person variation in working memory. The authors conclude that theories of cognitive aging should be evaluated by analysis of within-person processes, not exclusively age-related individual differences.     

Longitudinal study of the relationship between physical activity and knee pain and functional limitation in community-dwelling older adults

AimsTo describe the associations between interindividual (between-person) and intraindividual (within-person) variability in physical activity (PA) and knee pain and functional limitation among older adults. We also investigated the potential bidirectional association of between-person and within-person variability in knee pain and functional limitation with PA.MethodParticipants (N = 1064; 51% women; mean age 63 ± 7.4 years) were measured at baseline, 2.5, and 5 years. PA was measured using pedometers. Knee pain and functional limitation were assessed using the WOMAC scale. A two-part hurdle model, with adjustment for confounders, estimated the association of between-person and within-person variability in PA with knee pain/functional limitation (as the outcome). Linear mixed effect regression models described the association of between-person and within-person variability in knee pain and functional limitation with PA (as the outcome).ResultsBetween-person effects showed that participants with a higher 5-year average PA had lower average WOMAC scores (β= –1.17, 95% CI: –1.82, –0.51). Within-person effects showed that at time-points when participants had a higher PA level than average, they also had lower WOMAC scores (β= –0.85, 95% CI: –1.36, –0.35). Conversely, both between-person (β= –15.6, 95% CI: –22.5, –8.8) and within-person increase (β= –7.4, 95% CI: –13.5, –1.4) in WOMAC scores were associated with lower PA.ConclusionThese findings suggest that PA and knee pain/dysfunctional contribute to the development of one another. Pain can lead to changes in inter- and intraindividual PA levels, but the reverse is also possible – changes in PA results in changes in inter- and intraindividual pain/dysfunctional levels.     

Longitudinal relationships between cognitive functioning and depressive symptoms among Hispanic older adults

This study examines the relationship between cognitive functioning and depressive symptoms across 3 years in a prospective study of 273 community-dwelling, Hispanic older adults in Miami. The analyses extend the literature by testing for a bidirectional or reciprocal relationship between depressive symptoms and cognitive functioning over time and by examining the relationship between these variables among Hispanics, an understudied population at risk of developing depressive symptoms and cognitive impairments. Structural equation modeling with a cross-lagged panel design showed that depressive symptoms were unrelated to subsequent cognitive functioning. However, cognitive functioning was related to subsequent depressive symptoms at every time point, such that poorer cognitive functioning was related to higher depressive symptoms. Findings suggest that cognitive declines may predict depressive symptoms in community-dwelling Hispanic older adults.     

Depressive symptoms mediate the relationship between diabetes and cognitive performance in a community-based sample of older adults

AimsTo evaluate whether diabetes and prediabetes are associated with impaired cognitive performance among older adults and examine depressive symptoms as a mediator.MethodsWe used cross-sectional data from the Einstein Aging Study, a systematically recruited, community-based cohort study of diverse older adults (N = 794; Age Mean (SD) = 78.9 (5.3); 64.4% Non-Hispanic White, 28.7% Non-Hispanic Black, 5.7% Hispanic). Diabetes status was established via self-reported diagnosis, prescribed medications, and fasting blood glucose. Depressive symptoms were assessed using the Geriatric Depression Scale. Cognitive tests included Digit Symbol, Trails-B, Free Recall, Category Fluency, Boston Naming, and Block Design. Linear regression and mediation analyses were applied.ResultsCompared to those without diabetes, diabetes was associated with worse performance on all cognitive tests (ps < 0.05), except Trails-B (p = 0.53), and increased depressive symptoms (p < 0.01). For diabetes, mediation via increased depressive symptoms was observed for Free Recall (p = 0.044), Category Fluency (p = 0.033), and Boston Naming (p = 0.048).ConclusionsDiabetes was consistently associated with worse cognitive performance and increased depressive symptoms among this older cohort, while prediabetes was not. Mediation findings suggest depressive symptoms may be a biobehavioral pathway linking diabetes and cognition, though the temporal sequence is unclear. If causal, addressing both diabetes and depressive symptoms among older adults may protect cognitive function.     

Community-based structural social capital and depressive symptoms of older urban Chinese adults: The mediating role of cognitive social capital

ObjectivesThe present study aimed to investigate the mediating role of cognitive social capital in the association between community-based structural social capital and depressive symptoms among older adults living in urban China.MethodsData were derived from a community survey conducted in Suzhou City, China, in late 2015 with 456 respondents aged 60 or older. Structural equation modeling was used to test the proposed hypothesis.ResultsThe latent variables of cognitive and structural social capital were established. Cognitive social capital was found to have a mediation effect on the association between structural social capital and depressive symptoms, even after controlling for the respondents’ sociodemographic characteristics, health status, and family variables.ConclusionsThe findings support the utility of social capital theory in urban Chinese contexts. A more comprehensive assessment tool to measure structural social capital should be built nationwide. Fostering cognitive social capital should play an important role in interventions aiming to enhance structural social capital among older adults. Policy and intervention implications are discussed.     

The mediating and moderating effects of depressive symptoms on the prospective association between cognitive function and activities of daily living disability in older adults

ObjectivesThis study aimed to examine to what extent depressive symptoms mediated and moderated the association between cognitive function and activities of daily living (ADL) disability in older adults.MethodsIn older participants from the China Health and Longitudinal Retirement Survey (CHARLS), structural equation modeling and multiple regression were performed to examine the mediating and moderating role of depressive symptoms (measured by the 10-item Center for Epidemiologic Studies Depression Scale) in the association between baseline cognitive function (episodic memory, attention, orientation to time, and visuospatial ability) and endpoint disability in basic ADL (BADL) or instrumental ADL (IADL).ResultsOver a 2-year follow-up, among 1677 participants (67.5 ± 6.0 years old) free of BADL disability and 1194 participants (66.9 ± 5.6 years old) free of IADL disability, 8.3% and 22.9% developed BADL disability and IADL disability, respectively. Good baseline cognitive performance was significantly associated with the reduced incidence of BADL/IADL disability. The indirect effects of baseline depressive symptoms explained 16.9% and 14.5% of the total effect between cognition and BADL and IADL dependency, respectively. The Johnson-Neyman technique identified a threshold of 7.88 for endpoint depressive symptoms, beyond which the protective effect of baseline cognitive function on BADL emerged.ConclusionsIn older adults, good cognitive function reduces the risk of BADL/IADL disability. Depressive symptoms downregulate the protective effect of cognitive function on BADL/IADL over time. Intervention techniques focusing on the simultaneous improvement of cognitive dimensions and depression help improve ADL difficulty and prevent disability in older adults.     

Physical Activity and Depressive Symptoms Interact to Predict Executive Functioning Among Community-Dwelling Older Adults

Background/Study Context: Physical activity is beneficial for the executive functioning (EF) of older adults, but may be particularly protective of EF when they are cognitively vulnerable, such as during depressive episodes. Intervention studies support more potent effects of physical activity on EF among clinically depressed older adults, although these results may have limited generalizability to the daily mood and physical activity of healthy, community-dwelling older adults.

Methods: The current study aimed to test whether physical activity among older adults was more protective of EF during periods of cognitive vulnerability due to mildly elevated depressive symptoms. Longitudinal data from 150 generally healthy, community-dwelling older adults were collected semiannually and analyzed with multilevel modeling.

Results: Physical activity was more protective of EF within individuals during periods of relatively elevated depressive symptoms.

Conclusions: The power of physical activity to protect EF during periods of cognitive vulnerability may extend to community-dwelling older adults with nonclinical levels of depressive symptoms.     

Understanding Within-Group Variability of Everyday Cognition in Aging Black/African American Adults: A Mimic (Multiple Indicators,Multiple Causes) Model Approach

Background/Study Context: Everyday cognition represents the ability to solve problems within domains that are representative of issues faced by adults on a daily basis. The current study examined individual differences in everyday cognitive ability among aging Black/African American adults.

Methods: Demographic data on age, gender, education, physical functioning, chronic illnesses, self-reported health, and depression were collected from 248 African American adults (mean age = 67.8 years, standard deviation = 8.47 years). A multiple indicators, multiple causes (MIMIC) modeling approach was used to examine the associations of individual characteristics with latent everyday cognitive ability and composite score indicators.

Results: Age, depressive symptoms, and number of chronic illnesses were negatively related to latent everyday cognition. The individual characteristics of age, depressive symptoms, self-rated health, and education were directly associated with composite indicators of latent everyday cognition. This suggests that within this sample of older Black/African American adults that certain composite scores (i.e., telephone use, food preparation, and finances) may be particularly sensitive to these individual characteristics.

Conclusion: These results identify specific sources of variability in everyday cognitive ability among aging Blacks/African Americans. These individual differences should be accounted for when studying everyday cognition among Blacks/African Americans and when comparing the everyday cognitive ability of Blacks/African Americans with other groups.     

Cognitive deficits and the course of major depression in a cohort of middle-aged and older community-dwelling adults

OBJECTIVES: To examine associations between cognitive deficits and persistent significant depressive symptoms at baseline and 2- and 4-year follow-ups in a sample of community-dwelling middle-aged and older adults. DESIGN: Prospective cohort study. SETTING: A U.S. national prospective cohort study of middle-aged and older adults, the Health and Retirement Study. PARTICIPANTS: A sample of 661 participants of the 1996 wave of the Health and Retirement Study who met criteria for 12-month Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised major depression (MD). MEASUREMENTS: MD was assessed using the World Health Organization Composite International Diagnostic Interview-Short Form. Persistent significant depressive symptoms were assessed using an eight-item version of the Center for Epidemiological Studies Depression scale. RESULTS: Cognitive deficits were associated with persistent significant depressive symptoms at follow-up. In a latent state-trait analysis, two stable and strongly correlated traits best explained variations in cognitive functioning and depressive symptoms across assessment points. CONCLUSION: Trait-like cognitive deficits commonly complicate the course of MD in community-dwelling middle-aged and older adults and may help to explain the persistent course of depressive symptoms in a large subgroup of adults with MD in this age range.     

Healthy but unhappy? Cross-national comparative analysis of depressive symptoms in Japanese vs. Korean elders

BackgroundJapan and South Korea, two neighbouring countries in East Asia, enjoy the highest life expectancies in the world, yet suffer paradoxically from high suicide rates.AimWe sought to conduct a cross-national comparative analysis of depressive symptoms among older adults in Japan vs. Korea, focusing particularly on poverty and physical health status.MethodsWe used nationally representative samples aged 65 and over from the Comprehensive Survey of Living Conditions in Japan and the Korean Community Health Survey in South Korea. Multivariate logistic regression models were conducted to examine if equivalized household income, poor self-rated health, disability and comorbidity (number of diseases) were associated with depressive symptoms, adjusting for age, education, marital status, alcohol use, smoking and living alone.ResultsOlder Japanese adults with poor self-rated health and disability were more likely to report depressive symptoms, but income level was not significantly associated with mental distress. By contrast, among older Korean people, depressive symptoms were strongly patterned by household income level, as well as poor self-rated health, disability, and comorbidity.ConclusionPoor physical health status was correlated with depressive symptoms among both Japanese and Korean seniors. However, income level was associated with depressive symptoms among only Korean elders, but not Japanese. Thus, the current generation of older Japanese adults appears to enjoy (relative) financial security, longevity, and mental wellbeing. By contrast, older Koreans experience high levels of mental distress, especially if they are financially insecure.     

Effects of physical exercise on cognitive function of older adults with mild cognitive impairment: A systematic review and meta-analysis

Background and PurposeMild Cognitive Impairment (MCI) is associated with a greater risk of dementia for older adults. However, systematic reviews have shown that some physical exercise (PE) seems to improve MCI symptoms and signs. Those reviews and meta-analysis could not explain what possible moderator influenced their results. This meta-analysis aims to identify the effect of PE over older people’s cognition with MCI and explore sources of heterogeneity.MethodsDatabases were searched from inception January 2020 for randomized clinical trials that evaluated the effects of PE over cognition of older persons with MCI. Random effect meta-analyses were performed for each cognitive outcome. Subgroup analyses and meta-regressions models explored the potential sources of heterogeneity.ResultsA total of 2077 participants (mean age = 71.8 years) from 27 studies were included. PE improves global cognitive function (SMD = 0.348 [95 % CI 0.166 to 0.529]; p = 0.0001), executive function (SMD = 0.213 [95 % CI 0.026 to 0.400]; p = 0.026) and delayed recall (SMD = 0.180 [95 % CI 0.002 to 0.358]; p = 0.047). A trend towards beneficial effects of PE on verbal fluency (SMD = 0.270 [95 %, CI -0.021 to 0.561]; p = 0.069) and attention (SMD = 0.170 [CI -0.016 to 0.357]; p = 0.073) were also observed. Subgroup analyses showed a relationship between modality and intensity of physical exercise and changes observed in global cognitive function, executive function, delayed recall, verbal fluency and working memory.Discussion and ConclusionPE can ameliorate cognitive deficts of older adults with MCI. The most pronounced effects appear to arise from other types of exercise that included mind-body exercises and moderate intensity.     

Self-rated health and depressive symptoms in older adults: A growth mixture modeling approach

ObjectiveSelf-Rated Health (SRH) and depressive symptoms are important indicators of global quality of life in older adults. Prior research suggests associations between SRH and depressive symptoms. The current study assessed latent groups in levels and trajectories of these two subjective health indicators and how the latent groups relate to each other.MethodsParticipants from the Australian Longitudinal Study of Aging (N = 2,087, ages 65+) were assessed over six waves of data collection, spanning eight years.ResultsGrowth Mixture Models were run for SRH and depressive symptoms, each yielded three latent groups with similar patterns: for both SRH and depressive symptoms two groups differing in their level with worsening status over time, and a third stable, but poorer functioning group. Analysis of the assignment of the latent groups revealed a consistent pattern for the majority, but some people were high in depression and high in SRH and some were low in depression and low in SRH.ConclusionsSRH and depressive symptoms yielded both three latent groups whose combination supported the expected assignment for the majority and an unexpected assignment for some people. This may be a result of a protective factor existing for one variable but not the other.     

Longitudinal associations between cancer history and cognitive functioning among older adults

ObjectivesThis study aimed to examine (1) whether cancer history accelerates older adults’ rates of cognitive decline over time and (2) whether chemotherapy increases older cancer patients’/ survivors’ rates of cognitive decline over time.MethodsThis longitudinal study drew a subsample of 8811 adults aged 65 or older from Wave 6 of the Health and Retirement Study in 2002 and followed biennually until Wave 13 in 2016. Linear mixed-effects models were performed to test whether cancer history and chemotherapy were associated with accelerated rates of cognitive decline over time among older adults in different age groups.ResultsMiddle-old adults (aged 75–84) with a cancer history had significantly reduced rates of cognitive decline over time, including the global measure of cognitive functioning (B = 0.16, p< .01), mental status (B = 0.08, p< .01), and episodic memory (B = 0.09, p< .05) compared to their counterparts without a cancer history. This effect was not significant for the youngest-old (aged 65–74) or oldest-old adults (aged 85 or older). Also, chemotherapy was not significantly associated with older cancer patients’/survivors’ cognitive functioning at baseline or over time in different age groups.ConclusionsThis study finds that cancer history and chemotherapy do not further exacerbate older adults’ cognitive functioning over time. On the contrary, cancer history shows a “protective” effect on middle-old adults’ cognitive functioning. This encouraging finding indicates that older adults can be more actively engaged in the decision-making of treatments and following care plans. Future mediation studies are needed to further investigate underlying mechanisms.     

Relationship between exercise capacity and depressive symptoms in community-dwelling older adults

BackgroundDepressive symptoms cannot be ignored when exercise intervention is performed. The purpose of this study was to clarify the association between depressive symptoms and exercise capacity in community-dwelling older adults.MethodsIn this cross-sectional study, we analyzed 110 community-dwelling older adults (mean age [standard deviation] = 70.7 [4.0] years old; women: 55 %). Depressive symptoms were measured using a Japanese version of the Geriatric Depression Scale. We evaluated exercise capacity by measuring distance (2MWD) during a 2-minute walk test. Linear regression models were applied to analyze the association between 2MWD and depressive symptoms.ResultsThe results suggest that depressive symptoms are associated with low 2MWD (beta = −5.87, 95 % confidence interval = −11.18 to −0.57, p < 0.05) even after adjusting for age, gender, Body Mass Index, cigarette smoking, alcohol consumption, pain severity, and the number of comorbidities.ConclusionsThe results indicated that depressive symptoms are associated with decreased exercise capacity in older adults.     

Folate, Vitamin B12, Homocysteine, and Depressive Symptoms in a Population Sample of Older Chinese Adults

OBJECTIVES: To investigate the independent associations between folate, B12, and homocysteine levels and depressive symptoms in older adults.
DESIGN: Cross-sectional study.
SETTING: Resident population in southeast Singapore.
PARTICIPANTS: Six hundred sixty-nine community-living noninstitutionalized Chinese adults aged 55 and older.
MEASUREMENTS: Laboratory values of folate, vitamin B12, and homocysteine were examined for their independent relationships with depressive symptoms (Geriatric Depression Scale (GDS) score ≥5).
RESULTS: Respondents with depression (n=178) had lower mean serum folate concentrations (21.5 nmol/L) than those without (n=491, 24.0 nmol/L, P =.04). There was a linear relationship between descending quartiles of folate concentrations and increasing odds of association with depressive symptoms, independent of other risk factors (demographic, psychosocial, alcohol and smoking, chronic morbidity, functional status, nutritional risk, albumin, anemia, depression-inducing medications, use of antidepressants and vitamin supplements), including B12 and homocysteine ( P for trend=.02). The odds ratio (OR) of association between low folate (lowest quartile: <14.6 nmol/L) and depressive symptoms independent of other risk factors, including homocysteine and B12, was 1.72 (95% confidence interval (CI)=1.11–2.66). Vitamin B12 across a range of values did not show a linear association, but B12 deficiency (<180 pmol/L) appeared to be significantly associated with depressive symptoms (OR=2.68, 95% CI=1.20–6.00), independent of folate and homocysteine.
CONCLUSION: Decreasing and low levels of serum folate and deficient levels of B12 were associated with greater risk of depressive symptoms in older Chinese adults.     

Associations between cognitive function and endogenous levels of estradiol and testosterone in adults with type 2 diabetes

AimsTo assess associations that endogenous estradiol and testosterone levels have with cognitive function in older adults with Type 2 diabetes mellitus (T2DM).MethodsWe use data from the Look AHEAD clinical trial of behavioral weight loss. Endogenous estradiol and total testosterone levels were determined using stored serum from 996 individuals, mean age 69 years, at two times (averaging 4 years apart) during years 8–18 of follow-up. One to four standardized assessments of attention, executive function, memory, and verbal fluency were collected during this follow-up. Mixed effects models and multiple imputation were used to assess associations that estradiol and total testosterone levels had with body mass index and cognitive function.ResultsEstradiol levels were not associated with cognitive function in either sex. Total testosterone levels were not associated with cognitive function in women, but greater total testosterone levels were associated with better verbal fluency in men (p < 0.001), most strongly among those carrying the APOE-e4 allele (interaction p = 0.02). The weight loss intervention left a legacy of relatively lower cognitive functioning among women, which was not mediated by current levels of sex hormones.ConclusionsBehavioral weight loss intervention does not affect cognitive functioning through mechanisms related to estradiol or testosterone.ClinicalTrials.gov Identifier: NCT00017953.     

Physical health,subjective health,and psychological distress in older adults: Reciprocal relationships concurrently and over time

This study addresses the reciprocal associations between physical health (objectively assessed and self-rated) and psychological distress among older adults. Psychological distress (both depressive symptoms and anxiety level) made a significant independent contribution to the prediction of concurrent and future negative perception of one’s health, over and above objective health. As anxious and depressive components of psychological distress intensify, a negative outlook on life includes an increased negative view of one’s health among older adults. Conversely, negative subjective health independently predicted both depressive symptoms and anxiety level, concurrently and over time, over and above objective health. It thus appears that negative health appraisal heralds psychological distress, manifested as depressive symptoms and also anxiety among older adults. Taken together these findings draw the picture of a vicious circle of negative health appraisal leading to depression and anxiety, these in turn leading to further negative perception of health. His research and teaching activities are in the domain of psychogerontology, especially clinical geropsychology. His research interests include the treatment of depression, and reminiscence and autobiographical memory. Sabine Sèvre-Rousseau, Psy.D., defended her thesis in developmental psychology at the University of Paris V, Sorbonne. She was the coordinator of the mental health division of the Quebec Research Network on Aging during this study. She is also teaching psychology and statistical sciences at the Universities of Montreal and Sherbrooke. His research and teaching activities are in the domain of clinical geropsychology. In terms of research, he has a special interest for the etiology, assessment, and treatment of agitation and depression. Michel Préville, Ph.D., is associate professor at the Université de Sherbrooke, and Researcher at the Research Center on Aging, Scherbrooke Geriatric University Institute. He is director of the Mental Health Division of the Quebec Research Network on Aging.     

Family functioning and social support for older patients with depression in an urban area of Shanghai,China

PurposeGeriatric depression is now very common and leads to significant economic costs and family burden in China. Families with a depressed patient often report problematic family functioning in Western samples, and lack of social support is strongly associated with geriatric depression. However, the relationship between geriatric depression, family functioning and social support in mainland China has not been well studied.Materials and methodsThis study compared family functioning and social support in a Chinese sample of elderly patients with major depression and non-depressed elderly people, and evaluated the impact of family functioning, social support and socio-demographic factors on depression. A questionnaire was administered to 102 elderly patients with major depression and 107 non-depressed elderly people.ResultsThe elderly patients with major depression had worse family functioning and lower social support than elderly individuals without depression. Multivariate linear regression analysis showed associations between depressive symptoms and unhealthy family functioning, lower social support and single marital status.ConclusionsThe findings suggest that family interventions and improvement of social support are important in reducing depression among elderly patients. In addition, strategies to alleviate geriatric depression should be considered by the whole society, the community, family members and the depressed elderly patients themselves.