A 3-year follow-up study of social, lifestyle and health predictors of cognitive impairment in a Chinese older cohort

Physical Activity and Cognitive Decline Among Older Adults: A Systematic Review and Meta-Analysis

Importance

Physical activity is associated with the risk for cognitive decline, but much of the evidence in this domain comes from studies with short follow-ups, which is prone to reverse causation bias.

Objective

To examine how length of follow-up, baseline age, physical activity amount, and study quality modify the longitudinal associations of physical activity with cognition.

Data Sources

Observational studies of adults with a prospective follow-up of at least 1 year, a valid baseline cognitive measure or midlife cohort, and an estimate of the association of baseline physical activity and follow-up cognition were sought from PsycInfo, Scopus, CINAHL, Web of Science, SPORTDiscus, and PubMed, with the final search conducted on November 2, 2022.

Study Selection

Two independent researchers screened titles with abstracts and full-text reports.

Data Extraction and Synthesis

Two reviewers independently assessed study quality and extracted data. Pooled estimates of association were calculated with random-effects meta-analyses. An extensive set of moderators, funnel plots, and scatter plots of physical activity amount were examined. This study is reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

Main Outcomes and Measures

Pooled estimates of the associations between physical activity and global cognition, as well as specific cognitive domains, were examined.

Results

A total of 104 studies with 341 471 participants were assessed. Analysis of binary outcomes included 45 studies with 102 452 individuals, analysis of follow-up global cognition included 14 studies with 41 045 individuals, and analysis of change in global cognition included 25 studies with 67 463 individuals. Physical activity was associated with a decreased incidence of cognitive impairment or decline after correction for funnel plot asymmetry (pooled risk ratio, 0.97; 95% CI, 0.97-0.99), but there was no significant association in follow-ups longer than 10 years. Physical activity was associated with follow-up global cognition (standardized regression coefficient, 0.03; 95% CI, 0.02-0.03) and change in global cognition (standardized regression coefficient, 0.01; 95% CI, 0.01 to 0.02) from trim-and-fill analyses, with no clear dose-response or moderation by follow-up length, baseline age, study quality or adjustment for baseline cognition. The specific cognitive domains associated with physical activity were episodic memory (standardized regression coefficient, 0.03; 95% CI, 0.02-0.04) and verbal fluency (standardized regression coefficient, 0.05; 95% CI, 0.03-0.08).

Conclusions and Relevance

In this meta-analysis of the association of physical activity with cognitive decline, physical activity was associated with better late-life cognition, but the association was weak. However, even a weak association is important from a population health perspective.

Gender and age influence the association between gait speed and mild cognitive impairment in community-dwelling Japanese older adults: from the Japan Prospective Studies Collaboration for Ageing and Dementia (JPSC-AD)

BACKGROUND

Studies have shown that decreased gait speed is associated with impaired cognitive function. However, whether this association is equivalent across ages or genders in the older population remains unclear. Thus, we examined the association between mild cognitive impairment (MCI) and gait speed emphasising the influence of age and gender.

METHODS

Overall, 8233 Japanese participants aged ≥65 years were enrolled in this cross-sectional study between 2016 and 2018. After stratification by gender and age group, the participants' gait speeds were divided into quintiles, and the difference in MCI prevalence at each gait speed quintile was calculated. Logistic regression analyses were performed to assess the odds of MCI for each quintile and to assess the influence of age and gender.

RESULTS

Males had a consistently higher prevalence of MCI than females. The odds of MCI were increased as gait speed decreased. Logistic regression analyses revealed that in the multivariable-adjusted model 2, the odds ratios (95% confidence interval; CI) for MCI were 2.02 (1.47-2.76) for females and 1.75 (1.29-2.38) for males in the slowest gait speed quintiles compared to the fastest quintile. In the stratified analyses, only males showed an age-dependent increase in the associations between gait speed and MCI, while females exhibited comparable associations across age groups.

CONCLUSIONS

Reduced gait speed was associated with increased odds of MCI, and this association may vary according to gender and age. Therefore, gait speed could serve as a valuable screening tool for MCI, with gender- and age-dependent clinical implications.

Chronic cerebral hypoperfusion: a critical feature in unravelling the etiology of vascular cognitive impairment

Vascular cognitive impairment (VCI) describes a wide spectrum of cognitive deficits related to cerebrovascular diseases. Although the loss of blood flow to cortical regions critically involved in cognitive processes must feature as the main driver of VCI, the underlying mechanisms and interactions with related disease processes remain to be fully elucidated. Recent clinical studies of cerebral blood flow measurements have supported the role of chronic cerebral hypoperfusion (CCH) as a major driver of the vascular pathology and clinical manifestations of VCI. Here we review the pathophysiological mechanisms as well as neuropathological changes of CCH. Potential interventional strategies for VCI are also reviewed. A deeper understanding of how CCH can lead to accumulation of VCI-associated pathology could potentially pave the way for early detection and development of disease-modifying therapies, thus allowing preventive interventions instead of symptomatic treatments.

Social isolation, socioeconomic status, and development of functional impairments in Chinese older adults aged 70 years and over: a cohort study

BACKGROUND

Social isolation in older people has been increasingly regarded as a public health issue in the face of rapid population ageing. It is not clear whether social isolation mediates the relationship between socioeconomic status and functional impairment.

METHODS

We used data from a cohort of Chinese older people aged 70 or older living in community (n = 1590). Socioeconomic status (SES) was operationalised as highest education attainment, monthly income at baseline and longest held occupation in lifetime. Functional abilities were measured using Barthel's Index for activities of daily living (ADL) measured at 18 and 36 months of follow-up, from which impairment was defined as score ≤ 19. Social isolation was measured by six attributes, such as marital status, living alone, and social contact with others. A score of ≥ 3 was defined as being in social isolation. Causal mediation analysis using natural effect models was used to assess mediation by social isolation.

RESULTS

We found that lower monthly income at baseline was related to higher risk of social isolation [relative risk comparing lowest to highest income (RR) = 1.52, 95% confidence interval (95% CI) 1.01-2.28]. Social gradient of ADL impairment was not clearly present. The evidence for the mediating role of social isolation was not clear.

CONCLUSIONS

Older people with low SES, particularly those with lower income, were at greater risk of social isolation. Policymakers should strive to improve the current community services and pension scheme to mitigate the situation of social isolation in older people in Hong Kong.

Sex-specific longitudinal association between baseline physical activity level and cognitive decline in Chinese over 45 years old: Evidence from the China health and retirement longitudinal study

OBJECTIVES

To examine whether sex-specific associations between baseline PA level and follow up cognitive performance in Chinese subjects exist from the China Health and Retirement Longitudinal study (CHARLS).

METHOD

A total of 3395 adults aged 45 or old from the CHARLS were used for analysis. The combined scores of measurements of mental status and verbal episodic memory were utilized for assessing cognitive function at baseline in 2011 and the follow-up survey in 2015. Baseline PA level was quantified as the total PA score. Multiple linear regression and logistic regression models were used to examine the association between baseline PA status and global cognitive function and cognitive domains.

RESULTS

In the female subjects (n = 1748), compared with individuals of PA level in the lower tertile, those grouped into the upper tertile had the lowest risk of global cognitive decline [odds ratio (OR) =0.273, 95% confidence interval (CI) =0.077-0.960; p = 0.043] and verbal episodic memory decline [OR)=0.257, 95% CI =0.066-1.003; p = 0.051] from 2011 to 2015. However, no significant associations were observed in the male subjects (n = 1647).

CONCLUSION

In the female subjects, higher PA level was associated with reduced risk of cognitive decline within 4 years, this might be associated with reduced decline of verbal episodic memory. Our findings confirmed that female sex would positively affect the association between PA levels and cognitive decline.

Cognitive Impairment in Type 2 Diabetes Mellitus

Objective

To determine the incidence of cognitive impairment established on the mini-mental state assessment in type 2 diabetic patients presenting at Holy Family Hospital, Rawalpindi.

Materials and methods

This cross-sectional descriptive study was carried out from June 2019 to December 2019. Individuals with a diagnosis of type 2 diabetes mellitus were included, and detailed history, physical examination, and biochemical variables were noted. They were assessed through Mini-Mental State Examination (MMSE) (Urdu translation) to look for the primary outcome variable, i.e., cognitive impairment. All patients with type 2 diabetes mellitus diagnosed at least one year back, irrespective of gender, were included in this investigation. Patients with a previous history of head injury, epilepsy, stroke, those on an antidepressant or antipsychotic medications, those with deranged renal function tests, and those already diagnosed with dementia were excluded from the study.

Results

Three hundred thirty-two patients meeting the inclusion criteria were included in the study. The mean ± standard deviation age of the study population was 65.32 ± 11.33 years, with maximum age being 80 years and the minimum being 50 years. Two hundred patients (60.24%) were below 65 years of age, and 132 patients (39.76%) were 65 years of age or above. Two hundred sixteen (65.06%) were males, and 116 (34.96%) were females. The mean duration of diabetes mellitus (DM) was 10.17 ± 4.81. The mean MMSE score was 22.69 ± 5.26. Out of 332 patients, 81 (24.4%) patients had cognitive impairment. Patients who were 65 or older had a significantly higher proportion of cognitive impairment, compared to those below 65 years of age (p-value = 0.0214). There was no significant difference in the proportion of cognitively impaired patients between males and females (p-value = 0.2497). Similarly, there was no significant difference between those who were diagnosed with type 2 diabetes for 10 years or more and those who were diagnosed less than 10 years ago (p-value = 0.3791).

Conclusion

Cognitive impairment is common in individuals having type 2 diabetes mellitus. It is also associated with the increasing age of diabetic patients. However, cognitive impairment in type 2 diabetes mellitus is not associated with gender. In addition, there is no significant difference in cognitive impairment between the patients who were diagnosed with diabetes more than 10 years ago and those who had it diagnosed less than 10 years ago.

Social isolation, social support, and loneliness and their relationship with cognitive health and dementia

BACKGROUND

Poor social health is prevalent in older adults and may be associated with worse cognition, and increased dementia risk. The aim of this study was to determine whether social isolation, social support and loneliness are independently associated with cognitive function and incident dementia over 5 years in older adults, and to investigate potential gender differences.

METHODS

Participants were 11,498 community-dwelling relatively healthy Australians aged 70-94, in the ASPREE Longitudinal Study of Older Persons (ALSOP). Social isolation, social support, loneliness and cognitive function were assessed through self-report. Outcomes examined were cognitive decline (>1.5 SD decline in cognitive performance since baseline) and incident dementia (adjudicated according to DSM-IV criteria).

RESULTS

Most participants self-reported good social health (92%) with very few socially isolated (2%), with low social support (2%) or lonely (5%). Among women, social isolation and low social support were consistently associated with lower cognitive function (e.g., social support and cognition β = -1.17, p < 0.001). No consistent longitudinal associations were observed between baseline social health and cognitive decline (over median 3.1 years) or incident dementia (over median 4.4 years; social isolation: HR = 1.00, p = 0.99; low social support: HR = 1.79, p = 0.11; loneliness: HR = 0.72, p = 0.34 among women and men).

CONCLUSION

Our study provides evidence that social isolation and a low social support are associated with worse cognitive function in women, but not men. Social health did not predict incident cognitive decline or dementia, but we lacked power to stratify dementia analyses by gender.

Factors related to the performance of elderly people in temporal ordering tests

PURPOSE

To describe the performance of elderly individuals in Pitch Pattern Sequence (PPS) and Duration Pattern Sequence (DPS) tests and research related factors.

METHODS

An observational, cross-sectional study conducted with elderly people aged 60 to 79 years. The participants underwent cognitive screening tests, interviews containing socio-demographic data and general health, as well as audiologic evaluation and temporal auditory processing (PPS and DPS) evaluation tests. A descriptive analysis of the association between the performance in temporal processing and the variables gender, age, level of education and audiometric alterations was conducted through multiple linear regression.

RESULTS

86 elderly people participated in the study, most of them female, with ages between 60 and 69. Male participants performed better in both tests as well as the participants with higher education, whereas no difference in performance was observed across the different age ranges. In the DPS, the participants with auditory alteration performed worse in relation to the ones with average frequencies of 0.5 to 4 kHz.

CONCLUSION

The male gender and higher level of education were associated with better results in the temporal ordering tests, whereas auditory alteration was associated with worse performance only in the pitch pattern sequence test.

Associations between physical activity types and multi-domain cognitive decline in older adults from the Three-city cohort

Several studies suggest that physical activity improves cognitive functions and reduces cognitive decline, whereas others did not find any evidence of a neuroprotective effect. Furthermore, few cohort studies have analyzed the different physical activity types and particularly household activities. Our objective was to assess the association of two physical activity types with the decline in different cognitive domains in a large prospective cohort of community-dwelling older adults from the Three-city study. Physical activity (domestic/transportation activities and leisure/sport activities) was assessed with the Voorrips questionnaire, specific for older adults. Baseline sociodemographic and health history variables as well as cognitive performance data at baseline and during the 8-year follow-up (Mini-Mental State Examination, Benton Visual Retention Test, Trail Making Tests A and B, Isaac's Set Test and Free and Cued Selective Reminding Test) were also available. Associations between physical activity scores and cognitive decline in different domains were tested using minimally- and multi-adjusted linear mixed models. The analysis included 1697 participants without dementia at baseline and with at least one follow-up visit. At baseline, participants with higher sub-scores for the two physical activity types had better cognitive performances. Interaction with time showed that decline in some cognitive scores (Trail Making Test B and Isaac's Set Test) was significantly less pronounced in participants with higher household/transportation activity sub-scores. No significant effect over time was found for leisure/sport activities. This study shows that during an 8-year follow-up, executive functions and verbal fluency were better preserved in older adults who performed household/transportation activities at moderate to high level. Participation in domestic activities and using adapted transport means could allow older adults to maintain specific cognitive abilities.

Sexual Health Implications of COVID-19 Pandemic

INTRODUCTION

A novel coronavirus (COVID-19) reached pandemic levels by March 11th, 2020, with a destructive impact across socioeconomic domains and all facets of global health, but little is known of its impact on sexual health.

OBJECTIVE

To review current knowledge on sexual health-related containment measures during pandemics, specifically COVID-19, and focus on 2 main areas: intimacy and relational dynamics and clinical effects on sexual health.

METHODS

We carried out a literature search encompassing sexual health and pandemic issues using Entrez-PubMed and Google Scholar. We reviewed the implications of the COVID-19 pandemic on sexual health regarding transmission and safe sex practices, pregnancy, dating and intimacy amid the pandemic, benefits of sex, and impact on sexual dysfunctions.

RESULTS

Coronavirus transmission occurs via inhalation and touching infected surfaces. Currently, there is no evidence it is sexually transmitted, but there are sexual behaviors that pose a higher risk of infectivity due to asymptomatic carriers. Nonmonogamy plays a key role in transmission hubs. New dating possibilities and intimacy issues are highlighted. Sexual activity has a positive impact on the immune response, psychological health, and cognitive function and could mitigate psychosocial stressors. COVID-19 pandemic affects indirectly the sexual function with implications on overall health.

CONCLUSION

Increased awareness of health-care providers on sexual health implications related to the COVID-19 pandemic is needed. Telemedicine has an imperative role in allowing continued support at times of lockdown and preventing worsening of the sexual, mental, and physical health after the pandemic. This is a broad overview addressing sexual issues related to the COVID-19 pandemic. As this is an unprecedented global situation, little is known on sexuality related to pandemics. Original research is needed on the topic to increase the understanding of the impact the current pandemic may have on sexual health and function. Pennanen-Iire C, Prereira-Lourenço M, Padoa A, et al. Sexual Health Implications of COVID-19 Pandemic. Sex Med Rev 2021;9:3-14.

Social Isolation and Cognitive Function in Later Life: A Systematic Review and Meta-Analysis

BACKGROUND

There is some evidence to suggest that social isolation may be associated with poor cognitive function in later life. However, findings are inconsistent and there is wide variation in the measures used to assess social isolation.

OBJECTIVE

We conducted a systematic review and meta-analysis to investigate the association between social isolation and cognitive function in later life.

METHODS

A search for longitudinal studies assessing the relationship between aspects of social isolation (including social activity and social networks) and cognitive function (including global measures of cognition, memory, and executive function) was conducted in PsycInfo, CINAHL, PubMed, and AgeLine. A random effects meta-analysis was conducted to assess the overall association between measures of social isolation and cognitive function. Sub-analyses investigated the association between different aspects of social isolation and each of the measures of cognitive function.

RESULTS

Sixty-five articles were identified by the systematic review and 51 articles were included in the meta-analysis. Low levels of social isolation characterized by high engagement in social activity and large social networks were associated with better late-life cognitive function (r = 0.054, 95% CI: 0.043, 0.065). Sub-analyses suggested that the association between social isolation and measures of global cognitive function, memory, and executive function were similar and there was no difference according to gender or number of years follow-up.

CONCLUSIONS

Aspects of social isolation are associated with cognitive function in later life. There is wide variation in approaches to measuring social activity and social networks across studies which may contribute to inconsistencies in reported findings.

Effectiveness of peer counseling, social engagement, and combination interventions in improving depressive symptoms of community-dwelling Filipino senior citizens

INTRODUCTION

Little is known about community-based interventions for geriatric depression in low-resource settings. This study assessed the effectiveness of 3-month-duration interventions with peer counseling, social engagement, and combination vs. control in improving depressive symptoms of community-dwelling Filipino senior citizens.

METHODS

We conducted an open (non-blinded), non-randomized trial of senior citizens at risk for depression. Three different 3-month interventions included peer counseling (n = 65), social engagement (n = 66), and combination (n = 65) were compared with the control group (n = 68). We assessed geriatric depression, psychological resilience, perceived social support, loneliness, and working alliance scores at baseline and three months after the intervention. This trial was registered with ClinicalTrials.gov, identifier: NCT03989284.

RESULTS

Geriatric depression score over three months significantly improved in all intervention groups (control as reference). Significant improvements were also seen in psychological resilience and social support. Not all interventions, however, significantly improved the loneliness score. The combination group showed the largest effect of improving depressive symptoms (d = -1.33) whereas the social engagement group showed the largest effect of improving psychological resilience (d = 1.40), perceived social support (d = 1.07), and loneliness (d = -0.36) among senior citizens.

CONCLUSION

At the community level, peer counseling, social engagement, and combination interventions were effective in improving depressive symptoms, psychological resilience, and social support among Filipino senior citizens. This study shows that it is feasible to identify senior citizens at risk for depression in the community and intervene effectively to improve their mental health. Further studies are required to target loneliness and investigate the long-term benefits of the interventions.

CLINICAL TRIAL

ClinicalTrials.gov: NCT03989284.

The Relationship among Cognition, Psychological Well-being, Physical Activity and Demographic Data in People over 80 Years of Age

Objectives: It is the main goal of this study to investigate the relationships between physical abilities, cognitive abilities and the aspects of psychological well-being in people aged 80 or older. In contrast to other studies, we focus on the executive functions and mental rotation while investigating cognitive performance; this is because it is well known in the literature investigating younger participants that these functions relate to some kind of motor or physical activity. Methods: 41 independently living persons over 80 years were enrolled. Physical activities (German Physical Activity Questionnaire 50+), balance (One leg stand), psychological well-being (Resilience, General depressions scale), cognitive abilities (Flanker task, Mental rotation, Number connection test) as well as the influence of gender and education status were analyzed. Results: Higher physical activity correlates with higher resilience. Persons with higher education and men show better values on the depression scale. Better mental rotation ability could be detected in persons with higher education. Discussion: This first experimental study with people only over 80 years demonstrates the importance of education and physical activity for different aspects of psychological well-being. Due to the aim of investigating participants only over 80 years living independently the sample size is small so the study should be further enlarged.

Incidence and predictors of mild cognitive impairment (MCI) within a multi-ethnic Asian populace: a community-based longitudinal study

BACKGROUND

Limited information is available from longitudinal studies regarding the predictors and incidence of MCI in older Asian adults. Thus, a community-based longitudinal study was conducted to determine the incidence of MCI among multi-ethnic older adults in Malaysia. The role of health and lifestyle as predictors of MCI was also examined.

METHODS

Analysis of data obtained from the Towards Useful Aging (TUA) study (2014-2016), wave 1 (baseline) and wave 2 (1½ years of follow-up) was conducted. For the baseline, comprehensive, interview-based questionnaires were administered to 1227 subjects who were 60 years old and above. MCI is a unique transitional state between normal ageing and dementia. MCI characteristics include a decline and disturbance of cognition, minimal impairment of complex activities, ability to perform regular daily functions, and absence of dementia. The incidence of MCI was assessed using comprehensive neuropsychological batteries. The study then performed a logistic regression analysis to examine the effect of each possible predictor of MCI. This analysis began with univariate analyses and a separate review of the effect of every variable. Binary logistic analyses followed hereafter.

RESULTS

During the follow-up after 1½ years, 179 (14.6%) of the participants who did not exhibit MCI at baseline were observed to have developed MCI. Among the participants who did not exhibit MCI at baseline, the incidence rate was 10.5 per 100 person-years. Male sex and lack of engagement in mental activities were predictors of MCI among participants without MCI at baseline.

CONCLUSION

After the 1½-year follow-up, the incidence rate for MCI was considerably high among the respondents. Being male and being less engaged in mental activities were predictors of the occurrence of MCI. Mental activities need to be promoted for the prevention of MCI incidence among older adults.

Beyond health care: Volunteer work, social participation, and late-life general cognitive status in Taiwan

SIGNIFICANCE

In addition to the complexity associated with health care coverage and its utilization by older people, I hypothesize that social engagement promotes a better later-life general cognitive status beyond health care availability as is provided by Taiwan's National Health Insurance (NHI) system. The present study thus explores whether social engagement, specifically social participation and volunteer work, is independently associated with later-life general cognitive status after adjusting for health service utilization among older Taiwanese via the NHI system.

METHODS

Using a population-based natural experiment study design, data from the Taiwan Longitudinal Study on Aging (TLSA, 1993-2007) was analyzed. Mixed-effects models were conducted to estimate the relative effects of volunteer work, social participation, and NHI on general cognitive status over time, while taking health status, medical care utilization, community development, and social support into consideration.

RESULTS

The multivariate findings showed that a better general cognitive status is significantly associated with being actively involved in volunteer work (β = 0.14, p < 0.01) and social participation (β = 0.14, p < 0.01). In addition, NHI is also significantly associated with a higher level of general cognitive status (β = 0.10, p < 0.01).

DISCUSSION

This investigation suggests that social engagement has significant impacts on late-life general cognitive status, even taking into account the NHI system and its related utilization effects. The results highlight the importance of volunteer work and social participation among older Taiwanese because such social involvement produces a positive effect on their general cognitive status beyond health care itself. Furthermore, the contribution of productive activities to enhance late-life cognitive health is underscored.

Protective factors against cognitive decline among community-dwelling middle-aged and older people in Taiwan: A 6-year national population-based study

AIM

Dementia and cognitive impairment are important public health challenges to a rapidly aging country. The present study aimed to explore the protective factors against cognitive decline among community-dwelling middle-aged and older people from health, social, and lifestyle perspectives.

METHODS

Data of the Social Environment and Biomarkers of Aging Study, a population-based cohort study in Taiwan, were retrieved for the study. Overall, 676 participants with intact baseline cognitive function (measured by the Short Portable Mental Status Questionnaire) were enrolled and followed for six years. Any increasing score of the Short Portable Mental Status Questionnaire in the observational period was referred to as cognitive function decline. Associated factors for cognitive decline were identified by the logistic regression model.

RESULTS

Among all participants, 205 (30%) experienced cognitive decline during the study period. Crude logistic regression showed that women (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.3-2.6), low educational level (OR 2.0, 95% CI 1.4-3.0) and low mastery (OR 1.4, 95% CI 1.0-1.9) were associated with cognitive decline, but no daily consumption of vegetables and fruits had only a marginal association (OR 1.3, 95% CI 0.9-1.8). In the fully adjusted logistic regression analysis, old age, women, low educational level and low sense of mastery were independent predictors for cognitive decline. Participants with two modifiable factors (mastery, and daily consumptions of vegetables and fruits) had a lower risk of cognitive decline (OR 0.5, 95% CI 0.3-0.9), compared with those without any protective factor.

CONCLUSIONS

Participants with a better educational level, better personal mastery, and more consumption of fruits and vegetables were less likely to experience cognitive decline. An intervention study combining these features should be carried out to promote better cognitive health in communities. Geriatr Gerontol Int 2017: 17 (Suppl. 1): 20-27.

The impact of social activities, social networks, social support and social relationships on the cognitive functioning of healthy older adults: a systematic review

BACKGROUND

Social relationships, which are contingent on access to social networks, promote engagement in social activities and provide access to social support. These social factors have been shown to positively impact health outcomes. In the current systematic review, we offer a comprehensive overview of the impact of social activities, social networks and social support on the cognitive functioning of healthy older adults (50+) and examine the differential effects of aspects of social relationships on various cognitive domains.

METHODS

We followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, and collated data from randomised controlled trials (RCTs), genetic and observational studies. Independent variables of interest included subjective measures of social activities, social networks, and social support, and composite measures of social relationships (CMSR). The primary outcome of interest was cognitive function divided into domains of episodic memory, semantic memory, overall memory ability, working memory, verbal fluency, reasoning, attention, processing speed, visuospatial abilities, overall executive functioning and global cognition.

RESULTS

Thirty-nine studies were included in the review; three RCTs, 34 observational studies, and two genetic studies. Evidence suggests a relationship between (1) social activity and global cognition and overall executive functioning, working memory, visuospatial abilities and processing speed but not episodic memory, verbal fluency, reasoning or attention; (2) social networks and global cognition but not episodic memory, attention or processing speed; (3) social support and global cognition and episodic memory but not attention or processing speed; and (4) CMSR and episodic memory and verbal fluency but not global cognition.

CONCLUSIONS

The results support prior conclusions that there is an association between social relationships and cognitive function but the exact nature of this association remains unclear. Implications of the findings are discussed and suggestions for future research provided.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2012: CRD42012003248 .

As You Sow, So Shall You Reap: Gender-Role Attitudes and Late-Life Cognition

Some studies have found that women outperform men in episodic memory after midlife. But is this finding universal, and what are the reasons? Gender differences in cognition are the result of biopsychosocial interactions throughout the life course. Social-cognitive theory of gender development posits that gender roles may play an important mediating role in these interactions. We analyzed country differences in the gender differential in cognition after midlife using data from individuals age 50 and above ( N = 226,661) from 27 countries. As expected, older women performed relatively better in countries characterized by more equal gender-role attitudes. This result was robust to cohort differences as well as reverse causality. The effect was partially mediated by education and labor-force participation. Cognition in later life thus cannot be fully understood without reference to the opportunity structures that sociocultural environments do (or do not) provide. Global population aging raises the importance of understanding that gender roles affect old-age cognition and productivity.

A cross-sectional study on the factors related to cognitive decline in community-dwelling elderly

AIM

The aim of this study was to examine the relationship between cognitive decline and physical activity, sitting time, and social participation among elderly people living independently in a local community.

METHODS

In January 2015, 1,133 independently-living elderly individuals from a local Japanese community completed self-administrated questionnaires. A total of 929 participants completed the questionnaire (valid response rate: 82.0%). A multiple logistic regression analysis was conducted to examine the relationship between cognitive decline, physical activity, sitting time, and social participation. The factors related to cognitive decline were examined using three statistical models: (1) Model 1 was not adjusted for any factors; (2) Model 2 was adjusted for age, education level, smoking status, and drinking status; and (3) Model 3 was adjusted for the covariates in Model 2, plus depression.

RESULTS

Cognitive decline was observed in 33% of men and 26% of women. The results indicated that decreased social participation was significantly related to cognitive decline in Models 1 and 2. For men, local community activity and political/economic activity were significantly associated with cognitive decline in Models 1 and 2. Among women, physical activity was significantly related to cognitive decline in Model 1. There was also a significant association between social participation and cognitive decline in Models 1 and 2; decreased volunteer activity was significantly related to cognitive decline in all three models.

CONCLUSION

The results of the present study indicated that attending volunteer activities was significantly related to cognitive decline in women.

Impact of Physical Activity on Cognitive Decline, Dementia, and Its Subtypes: Meta-Analysis of Prospective Studies

The association of physical activity with dementia and its subtypes has remained controversial in the literature and has continued to be a subject of debate among researchers. A systematic review and meta-analysis of longitudinal studies on the relationship between physical activity and the risk of cognitive decline, all-cause dementia, Alzheimer's disease, and vascular dementia among nondemented subjects are considered. A comprehensive literature search in all available databases was conducted up until April 2016. Well-defined inclusion and exclusion criteria were developed with focus on prospective studies ≥ 12 months. The overall sample from all studies is 117410 with the highest follow-up of 28 years. The analyses are performed with both Bayesian parametric and nonparametric models. Our analysis reveals a protective effect for high physical activity on all-cause dementia, odds ratio of 0.79, 95% CI (0.69, 0.88), a higher and better protective effect for Alzheimer's disease, odds ratio of 0.62, 95% CI (0.49, 0.75), cognitive decline odds ratio of 0.67, 95% CI (0.55, 0.78), and a nonprotective effect for vascular dementia of 0.92, 95% CI (0.62, 1.30). Our findings suggest that physical activity is more protective against Alzheimer's disease than it is for all-cause dementia, vascular dementia, and cognitive decline.

Walking Pace and the Risk of Cognitive Decline and Dementia in Elderly Populations: A Meta-analysis of Prospective Cohort Studies

BACKGROUND

Data on the longitudinal association of walking pace with the risk of cognitive decline and dementia are inconsistent and inconclusive. Therefore, researchers conducted a meta-analysis of prospective cohort studies to quantitatively assess the association of walking pace with the risk of cognitive decline and dementia among elderly populations.

METHODS

Eligible studies were searched in PubMed and EMBASE through April 22, 2016. Additional information was retrieved through Google Scholar or hand review of the reference lists from the relevant studies. Prospective cohort studies were included if they reported relative risk (RR) and the corresponding 95% confidence interval (CI) of cognitive decline or dementia in relation to walking pace.

RESULTS

Seventeen studies were identified, including 10 studies reporting the RR of cognitive decline (9,949 participants and 2,547 events) and 10 presenting the RR of dementia (14,140 participants and 1,903 events). Comparing the lowest to the highest category of walking pace, the pooled RR was 1.89 (95% CI = 1.54-2.31) for cognitive decline and 1.66 (95% CI = 1.43-1.92) for dementia. With every 1 dm/s (360 m/h) decrement in walking pace, the risk of dementia was increased by 13% (RR = 1.13; 95% CI = 1.08-1.18).

CONCLUSIONS

This meta-analysis provides accumulated evidence supporting that slow or decreased walking pace is significantly associated with elevated risk of cognitive decline and dementia in elderly populations.

Exercise as medicine - evidence for prescribing exercise as therapy in 26 different chronic diseases

This review provides the reader with the up-to-date evidence-based basis for prescribing exercise as medicine in the treatment of 26 different diseases: psychiatric diseases (depression, anxiety, stress, schizophrenia); neurological diseases (dementia, Parkinson's disease, multiple sclerosis); metabolic diseases (obesity, hyperlipidemia, metabolic syndrome, polycystic ovarian syndrome, type 2 diabetes, type 1 diabetes); cardiovascular diseases (hypertension, coronary heart disease, heart failure, cerebral apoplexy, and claudication intermittent); pulmonary diseases (chronic obstructive pulmonary disease, asthma, cystic fibrosis); musculo-skeletal disorders (osteoarthritis, osteoporosis, back pain, rheumatoid arthritis); and cancer. The effect of exercise therapy on disease pathogenesis and symptoms are given and the possible mechanisms of action are discussed. We have interpreted the scientific literature and for each disease, we provide the reader with our best advice regarding the optimal type and dose for prescription of exercise.

Physical activity and cognitive function among older adults in China: A systematic review

BACKGROUND

Physical activity (PA) has been shown to benefit cognitive function in older adults. However, the cognitive benefits of exercising for older Chinese adults have not been systematically documented. This study was to conduct a systematic review on evidence that PA is beneficial for cognitive functioning in older Chinese adults.

METHODS

Major databases, including PubMed, EMBASE, Cochrane Library, WanFang, CNKI, and VIP, were searched for studies published in English or Chinese between January 2000 and December 2015. Randomized and non-randomized controlled trials (RCTs and non-RCTs), cohort, case-control and cross-sectional studies that evaluated PA and cognitive function among older Chinese adults were included in this review.

RESULTS

Of 53 studies included and reviewed, 33 were observational (22 cross-sectional, 7 case-control, and 4 cohort) and 20 were experimental (15 RCTs, 5 non-RCTs). Observational studies showed an association of reduced risk of cognitive-related diseases (i.e., mild cognitive impairment, Alzheimer's disease, and dementia) through PA, whereas experimental studies reported exercise-induced improvement in multiple domains of cognitive function (i.e., global cognitive function, memory, executive function, attention, language, and processing recourse).

CONCLUSION

This systematic review provides initial evidence that PA may benefit cognition in older Chinese adults. Further studies of individuals with cognitive impairments and prospective and RCT studies having high scientific rigor are needed to corroborate the findings reported in this review.

Prevalence and correlates of cognitive impairment and depression among elderly people in the world's fastest growing city, Chongqing, People's Republic of China

Background

Cognitive impairment and depression are major mental health problems affecting older people. The current study was designed to explore the prevalence of cognitive impairment and depression in representative sample of elderly people aged ≥60 years and to examine the correlates of cognitive impairment and depression with other sociodemographic variables.

Methods

A cross-sectional study based on comprehensive geriatric assessment of 538 elderly Chinese people was conducted from September 2011 to August 2012. Cognitive impairment was assessed using the Chinese version of Mini-Mental State Examination, and depressive symptoms were assessed by 30-item geriatric depression scale.

Results

The prevalence of cognitive impairment was 12.6%. Multiple logistic regression analysis revealed that the following were significant independent predictors of cognitive impairment: female, having a low level of education, increasing age, and depression. The overall prevalence of depression was 24.3%, and in adjusted model, cognitive impairment was only associated with increased risk of depression.

Conclusion

Cognitive impairment and depression are prevalent in elderly Chinese people. Among a number of factors identified in our study, cognitive impairment and depression were highly correlated in elderly people aged ≥60 years.

Social relationships and cognitive decline: a systematic review and meta-analysis of longitudinal cohort studies

BACKGROUND

Although poor social relationships are assumed to contribute to cognitive decline, meta-analytic approaches have not been applied. Individual study results are mixed and difficult to interpret due to heterogeneity in measures of social relationships. We conducted a systematic review and meta-analysis to investigate the relation between poor social relationships and cognitive decline.

METHODS

MEDLINE, Embase and PsycINFO were searched for longitudinal cohort studies examining various aspects of social relationships and cognitive decline in the general population. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using random effects meta-analysis. Sources of heterogeneity were explored and likelihood of publication bias was assessed. We stratified analyses according to three aspects of social relationships: structural, functional and a combination of these.

RESULTS

We identified 43 articles. Poor social relationships predicted cognitive decline; for structural (19 studies): pooled OR: 1.08 (95% CI: 1.05-1.11); functional (8 studies): pooled OR: 1.15 (95% CI: 1.00-1.32); and combined measures (7 studies): pooled OR: 1.12 (95% CI: 1.01-1.24). Meta-regression and subgroup analyses showed that the heterogeneity could be explained by the type of social relationship measurement and methodological quality of included studies.

CONCLUSIONS

Despite heterogeneity in study design and measures, our meta-analyses show that multiple aspects of social relationships are associated with cognitive decline. As evidence for publication bias was found, the association might be overestimated and should therefore be interpreted with caution. Future studies are needed to better define the mechanisms underlying these associations. Potential causality of this prognostic association should be examined in future randomized controlled studies.

Walking ability to predict future cognitive decline in old adults: A scoping review

Early identification of individuals at risk for cognitive decline may facilitate the selection of those who benefit most from interventions. Current models predicting cognitive decline include neuropsychological and/or biological markers. Additional markers based on walking ability might improve accuracy and specificity of these models because motor and cognitive functions share neuroanatomical structures and psychological processes. We reviewed the relationship between walking ability at one point of (mid) life and cognitive decline at follow-up. A systematic literature search identified 20 longitudinal studies. The average follow-up time was 4.5 years. Gait speed quantified walking ability in most studies (n=18). Additional gait measures (n=4) were step frequency, variability and step-length. Despite methodological weaknesses, results revealed that gait slowing (0.68-1.1 m/sec) preceded cognitive decline and the presence of dementia syndromes (maximal odds and hazard ratios of 10.4 and 11.1, respectively). The results indicate that measures of walking ability could serve as additional markers to predict cognitive decline. However, gait speed alone might lack specificity. We recommend gait analysis, including dynamic gait parameters, in clinical evaluations of patients with suspected cognitive decline. Future studies should focus on examining the specificity and accuracy of various gait characteristics to predict future cognitive decline.

Influence of Formal Education on Cognitive Reserve in Patients with Multiple Sclerosis

The concept of cognitive reserve (CR) and its influence on cognitive impairment has attracted increasing interest. One hundred twenty-eight patients with multiple sclerosis (MS) from Southern Germany were evaluated during the years 2000 to 2012. Twenty-seven neuropsychological (NP) tests were applied regarding basic cognitive functions, attention, executive functions, visual perception and construction, memory and learning, problem solving, and language. By this retrospective approach, a comprehensive NP profile of the investigated individuals was established. An effect of timespan of formal education on CR was observed. Enrichment by reading, physical activities, and challenging vocational practices had more profound effects in patients who had undergone a shorter educational period compared to a longer educational period. In summary, our study demonstrates that the advantage of longer formal education periods, compared to shorter formal education periods, can be counterbalanced by high frequencies of reading, physical activities, and challenging vocational practices in patients with MS.

Association between Lifetime Physical Activity and Cognitive Functioning in Middle-Aged and Older Community Dwelling Adults: Results from the Brain in Motion Study

To determine if total lifetime physical activity (PA) is associated with better cognitive functioning with aging and if cerebrovascular function mediates this association. A sample of 226 (52.2% female) community dwelling middle-aged and older adults (66.5 ± 6.4 years) in the Brain in Motion Study, completed the Lifetime Total Physical Activity Questionnaire and underwent neuropsychological and cerebrovascular blood flow testing. Multiple robust linear regressions were used to model the associations between lifetime PA and global cognition after adjusting for age, sex, North American Adult Reading Test results (i.e., an estimate of premorbid intellectual ability), maximal aerobic capacity, body mass index and interactions between age, sex, and lifetime PA. Mediation analysis assessed the effect of cerebrovascular measures on the association between lifetime PA and global cognition. Post hoc analyses assessed past year PA and current fitness levels relation to global cognition and cerebrovascular measures. Better global cognitive performance was associated with higher lifetime PA (p=.045), recreational PA (p=.021), and vigorous intensity PA (p=.004), PA between the ages of 0 and 20 years (p=.036), and between the ages of 21 and 35 years (p.5), but partially mediated the relation between current fitness and global cognition. This study revealed significant associations between higher levels of PA (i.e., total lifetime, recreational, vigorous PA, and past year) and better cognitive function in later life. Current fitness levels relation to cognitive function may be partially mediated through current cerebrovascular function.

Physical activity and dementia: long-term follow-up study of adult twins

INTRODUCTION

Physical activity is associated with a decreased occurrence of dementia. In twins, we investigated the effect of persistent physical activity in adulthood on mortality due to dementia.

MATERIALS AND METHODS

Physical activity was queried in 1975 and 1981 from the members of the older Finnish Twin Cohort (n = 21,791), who were aged 24-60 years at the end of 1981. The subjects were divided into three categories according to the persistence of their vigorous physical activity. Dementia deaths were followed up to the end of 2011.

RESULTS

During the 29-year follow-up, 353 subjects died of dementia. In individual-based analyses the age- and sex-adjusted hazard ratio (HR) was 0.65 (95% CI 0.43-0.98) for subjects partaking in vigorous physical activities in both 1975 and 1981 compared to those who were inactive in both years. No significant change was observed after adjusting for potential confounding factors. The corresponding HR for within-pair comparisons of the less active twin versus the more active co-twin was 0.48 (95% CI 0.17-1.32). The results for analyses of the volume of physical activity were inconclusive.

CONCLUSIONS

Persistent vigorous leisure-time physical activity protects from dementia, and the effect appears to remain after taking into account childhood environment.

Executive functions in men and postmenopausal women

INTRODUCTION

This study was designed to assess sex differences in older adults (55-65 years old) in executive functions and to examine the influence of hormone therapy (HT) in postmenopausal women.

METHOD

We have assessed task performance in memory, visuospatial, and executive functions in 29 women using HT, 29 women who never used HT, and 30 men.

RESULTS

Men outperformed never users in task switching and updating. HT users outperformed never users in updating. HT users outperformed never users and men in visual divided attention.

DISCUSSION

The present study support previous findings that sex and HT impact cognition and bring new insights on sex and HT-related differences in executive functions.

A battery of tests for assessing cognitive function in U.S. Chinese older adults--findings from the PINE Study

BACKGROUND

Existing methodological challenges in aging research has dampened our assessment of cognitive function among minority older adults. We aim to report the composite scores of five cognitive function tests among U.S. Chinese older adults, and examine the association between cognitive function and key sociodemographic characteristics.

METHODS

The Population Study of Chinese Elderly in Chicago Study enrolled an epidemiological cohort of 3,159 community-dwelling Chinese older adults. We administered five cognitive function tests, including the Chinese Mini-Mental State Examination, the immediate and delayed recall of the East Boston Memory Test, the Digit Span Backwards assessment, and the Symbol Digit Modalities Test. We used Spearman correlation coefficients to examine the correlation between cognitive function and sociodemographic variables. Linear regression models were used to report the effect of sociodemographic and health variables including age, sex, education on cognitive function.

RESULTS

Our multivariate analysis suggested that performance in each domain of cognitive function was inversely associated with age and positively related to education. With respect to sex, after adjusted for age, education and all key variables presented in the model, being male was positively related to global cognitive score and working memory. Being married, having fewer children, having been in the United States for fewer years, having been in the community for fewer years, and better self-reported health were positively correlated with all cognitive function domains.

CONCLUSIONS

This population-based study of U.S. Chinese older adults is among the first to examine a battery of five cognitive function tests, which in aggregate enables researchers to capture a wide range of cognitive performance.

Life-course socio-economic disadvantage and late-life cognitive functioning in Taiwan: results from a national cohort study

BACKGROUND

Declines in late-life cognitive functioning differ greatly between socio-economic status (SES) groups, but little is known about whether these effects are related to child and adult SES versus SES effects that accumulate over the individual's life course.

METHODS

An 18-year longitudinal national sample of older adults from Taiwan (n=2944) was used to estimate the effect of socio-economic disadvantage over the individual's life course on cognitive functioning during late life. Cognitive functioning was assessed using the brief Short Portable Mental Status Questionnaire scale. Life-course socio-economic disadvantage, as accrued during childhood and adulthood, included measures of paternal education and occupation and participant's education and occupation.

RESULTS

Multivariate analyses using various mixed-effects models showed that the effects of childhood SES could be largely explained by adult SES and that disadvantageous SES in adulthood further exacerbated declines in late-life cognitive functioning (β=-0.02; p<0.001), even controlling for aging, practice and other covariates. Possible factors that are associated with life-course socio-economic disadvantage and late-life cognitive decline included household income and perception of economic strain.

CONCLUSIONS

The results suggest a critical role for life-course socio-economic disadvantage in late-life cognitive decline and that this may be manifested via the inequitable distribution of socio-economic resources over the individual's life course.

Interventions to reduce the number of falls among older adults with/without cognitive impairment: an exploratory meta-analysis

OBJECTIVE

This exploratory meta-analysis aimed to examine and compare the effective interventions to prevent falls among institutionalized/non-institutionalized older adults without cognitive impairment with interventions to prevent falls for older adults with cognitive impairment.

DESIGN

A database search identified 111 trials published between January 1992 and August 2012 that evaluated fall-prevention interventions among institutionalized/non-institutionalized older adults with and without cognitive impairment as measured by valid cognition scales.

RESULTS

Exercise alone intervention was similar effective on reducing the numbers of falls among older adults without cognitive impairment regardless of setting (non-institutionalized: OR = 0.783, 95% confidence interval (CI) = 0.656-0.936; p = 0.007 institutionalized: OR = 0.799, 95% CI = 0.646-0.988, p = 0.038). Vitamin D/calcium supplementation had a positive effect on the reduction of numbers of falls among non-institutionalized older adults without cognitive impairment (OR = 0.789, 95% CI = 0.631-0.985, p = 0.036), as did home visits and environment modification (OR = 0.751, 95% CI = 0.565-0.998, p = 0.048). Exercise alone, exercise-related multiple interventions, and multifactorial interventions were associated with positive outcomes among both institutionalized and non-institutionalized older adults with cognitive impairment, but studies are limited.

CONCLUSIONS

Single exercise interventions can significantly reduce numbers of falls among older adults with and without cognitive impairment in institutional or non-institutional settings. Vitamin D and calcium supplementation, home visits, and environment modification can reduce the risk of falls among older adults in non-institutional settings. Exercise-related multiple interventions and multifactorial interventions may only be effective for preventing falls in older adults with cognitive impairment.

Epidemiologic studies of modifiable factors associated with cognition and dementia: systematic review and meta-analysis

Background

Cognitive impairment, including dementia, is a major health concern with the increasing aging population. Preventive measures to delay cognitive decline are of utmost importance. Alzheimer’s disease (AD) is the most frequent cause of dementia, increasing in prevalence from <1% below the age of 60 years to >40% above 85 years of age.

Methods

We systematically reviewed selected modifiable factors such as education, smoking, alcohol, physical activity, caffeine, antioxidants, homocysteine (Hcy), n-3 fatty acids that were studied in relation to various cognitive health outcomes, including incident AD. We searched MEDLINE for published literature (January 1990 through October 2012), including cross-sectional and cohort studies (sample sizes > 300). Analyses compared study finding consistency across factors, study designs and study-level characteristics. Selecting studies of incident AD, our meta-analysis estimated pooled risk ratios (RR), population attributable risk percent (PAR%) and assessed publication bias.

Results

In total, 247 studies were retrieved for systematic review. Consistency analysis for each risk factor suggested positive findings ranging from ~38.9% for caffeine to ~89% for physical activity. Education also had a significantly higher propensity for “a positive finding” compared to caffeine, smoking and antioxidant-related studies. Meta-analysis of 31 studies with incident AD yielded pooled RR for low education (RR = 1.99; 95% CI: 1.30-3.04), high Hcy (RR = 1.93; 95% CI: 1.50-2.49), and current/ever smoking status (RR = 1.37; 95% CI: 1.23-1.52) while indicating protective effects of higher physical activity and n-3 fatty acids. Estimated PAR% were particularly high for physical activity (PAR% = 31.9; 95% CI: 22.7-41.2) and smoking (PAR%=31.09%; 95% CI: 17.9-44.3). Overall, no significant publication bias was found.

Conclusions

Higher Hcy levels, lower educational attainment, and decreased physical activity were particularly strong predictors of incident AD. Further studies are needed to support other potential modifiable protective factors, such as caffeine.

Does physical activity prevent cognitive decline and dementia?: A systematic review and meta-analysis of longitudinal studies

BACKGROUND

By 2050, it has been estimated that approximately one-fifth of the population will be made up of older adults (aged ≥60 years). Old age often comes with cognitive decline and dementia. Physical activity may prevent cognitive decline and dementia.

METHODS

We reviewed and synthesised prospective studies into physical activity and cognitive decline, and physical activity and dementia, published until January 2014. Forty-seven cohorts, derived from two previous systematic reviews and an updated database search, were used in the meta-analyses. Included participants were aged ≥40 years, in good health and/or randomly selected from the community. Studies were assessed for methodological quality.

RESULTS

Twenty-one cohorts on physical activity and cognitive decline and twenty-six cohorts on physical activity and dementia were included. Meta-analysis, using the quality-effects model, suggests that participants with higher levels of physical activity, when compared to those with lower levels, are at reduced risk of cognitive decline, RR 0.65, 95% CI 0.55-0.76, and dementia, RR 0.86, 95% CI 0.76-0.97. Sensitivity analyses revealed a more conservative estimate of the impact of physical activity on cognitive decline and dementia for high quality studies, studies reporting effect sizes as ORs, greater number of adjustments (≥10), and longer follow-up time (≥10 years). When one heavily weighted study was excluded, physical activity was associated with an 18% reduction in the risk of dementia (RR 0.82; 0.73-0.91).

CONCLUSIONS

Longitudinal observational studies show an association between higher levels of physical activity and a reduced risk of cognitive decline and dementia. A case can be made for a causal interpretation. Future research should use objective measures of physical activity, adjust for the full range of confounders and have adequate follow-up length. Ideally, randomised controlled trials will be conducted. Regardless of any effect on cognition, physical activity should be encouraged, as it has been shown to be beneficial on numerous levels.

Cognitive impairment, depression, comorbidity of the two and associated factors among the early sixties in a rural Korean community

This study was conducted to investigate the prevalence of cognitive impairment, depression, and comorbidity of the two conditions and related factors in subjects aged in early 60s. This cross-sectional study included 3,174 inhabitants aged 60-64 years old in a rural area of Korea. Cognitive function was evaluated by the Korean version of the Mini-Mental State Examination (MMSE-K), and depression was measured using the short form of the Geriatric Depression Scale (GDS-15). The overall prevalence of cognitive impairment (MMSE-K ≤ 24) was 17.4%, that of depression was 26.0% (GDS-15 ≥ 8), and the co-morbidity was 7.1%. Female gender, living with one housemate, and high GDS-15 score were significantly associated with increased cognitive impairment. Employment status and more years of schooling were associated with a decreased probability of cognitive impairment. Increased depression was significantly associated with bereavement and receiving benefits from the Medical Aid Program. Employed status, more years of schooling, and higher MMSE-K scores were significantly associated with decreased depression. The risk of comorbidity was associated with bereavement and receipt of Medical Aid benefits (odds ratio[OR], 1.85; 95% confidence interval[CI], 1.26-2.71; OR, 5.02; 95% CI, 2.37-10.63; respectively). Employment and more years of schooling were associated with a lower risk of comorbidity (OR, 0.46; 95% CI, 0.34-0.62, P-trend <0.01). The correlated factors for cognitive impairment, depression, and comorbidity of the two conditions were similar, and employment status and years of schooling were associated with all three conditions.

Multiple effects of physical activity on molecular and cognitive signs of brain aging: can exercise slow neurodegeneration and delay Alzheimer's disease?

Western countries are experiencing aging populations and increased longevity; thus, the incidence of dementia and Alzheimer's disease (AD) in these countries is projected to soar. In the absence of a therapeutic drug, non-pharmacological preventative approaches are being investigated. One of these approaches is regular participation in physical activity or exercise. This paper reviews studies that have explored the relationship between physical activity and cognitive function, cognitive decline, AD/dementia risk and AD-associated biomarkers and processes. There is now strong evidence that links regular physical activity or exercise to higher cognitive function, decreased cognitive decline and reduced risk of AD or dementia. Nevertheless, these associations require further investigation, more specifically with interventional studies that include long follow-up periods. In particular, relatively little is known about the underlying mechanism(s) of the associations between physical activity and AD neuropathology; clearly this is an area in need of further research, particularly in human populations. Although benefits of physical activity or exercise are clearly recognised, there is a need to clarify how much physical activity provides the greatest benefit and also whether people of different genotypes require tailored exercise regimes.

The influence of exercise on brain aging and dementia

Physical activity has been recognized as an important protective factor reducing disability and mortality and therefore it is focus of many health promotion activities at all ages. More recently a growing body of literature is focusing whether physical activity could also have a positive impact on brain aging with exploring healthy brain aging as well as on cognitive impairment and dementia. An increasing number of prospective studies and randomized controlled trials involving humans take place both with older adults with normal cognition as well as with mild cognitive impairment or dementia. However, the body of evidence is still sparse and many methodological issues make comparisons across studies challenging. Increasingly research into underlying mechanisms in relation to physical activity and brain aging identify biomarker candidates with especially neuroimaging measurements being more used in trials with humans. Whilst the evidence base is slowly growing more detailed research is needed to address methodological issues to finally achieve clinical relevance. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease.

Social participation reduces depressive symptoms among older adults: an 18-year longitudinal analysis in Taiwan

Background

Relatively little empirical attention has focused on the association between social participation and depressive symptoms amongst older adults in Asian nations, where persons over the age of 65 represent a rapidly growing segment of the population. This study explores the dynamic relationship between participation in social activities and trajectories of depressive symptomatology among older Taiwanese adults surveyed over 18 years.

Methods

Data are from a nationally representative sample of 1,388 adults aged 60-64 first surveyed in 1989 and followed over an 18-year time period for a total of six waves. Individual involvement in social activities was categorized into continuous participation, ceased participation before age 70, initiating participation in older adulthood, never participated, and dropped out before age 70. Two domains of depressive symptoms--negative affect and lack of positive affect--were measured using a 10-item version of the Center for Epidemiologic Studies-Depression Scale.

Results

Analyses using growth curve modeling showed that continuously participating or initiating participation in social activities later life is significantly associated with fewer depressive symptoms among older Taiwanese adults, even after controlling for the confounding effects of aging, individual demographic differences, and health status.

Conclusions

These findings suggest that maintaining or initiating social participation in later life benefits the mental health of older adults. Facilitating social activities among older adults is a promising direction for programs intended to promote mental health and successful aging among older adults in Taiwan.

Multiple imputation was an efficient method for harmonizing the Mini-Mental State Examination with missing item-level data

OBJECTIVE

The Mini-Mental State Examination (MMSE) is used to estimate current cognitive status and as a screen for possible dementia. Missing item-level data are commonly reported. Attention to missing data is particularly important. However, there are concerns that common procedures for dealing with missing data, for example, listwise deletion and mean item substitution, are inadequate.

STUDY DESIGN AND SETTING

We used multiple imputation (MI) to estimate missing MMSE data in 17,303 participants who were drawn from the Dynamic Analyses to Optimize Aging project, a harmonization project of nine Australian longitudinal studies of aging.

RESULTS

Our results indicated differences in mean MMSE scores between those participants with and without missing data, a pattern consistent over age and gender levels. MI inflated MMSE scores, but differences between those imputed and those without missing data still existed. A simulation model supported the efficacy of MI to estimate missing item level, although serious decrements in estimation occurred when 50% or more of item-level data were missing, particularly for the oldest participants.

CONCLUSIONS

Our adaptation of MI to obtain a probable estimate for missing MMSE item level data provides a suitable method when the proportion of missing item-level data is not excessive.

Physical activity and risk of cognitive decline: a meta-analysis of prospective studies

OBJECTIVE

The relationship between physical activity and cognitive function is intriguing but controversial. We performed a systematic meta-analysis of all the available prospective studies that investigated the association between physical activity and risk of cognitive decline in nondemented subjects.

METHODS

We conducted an electronic literature search through MedLine, Embase, Google Scholar, Web of Science, The Cochrane Library and bibliographies of retrieved articles up to January 2010. Studies were included if they analysed prospectively the association between physical activity and cognitive decline in nondemented subjects.

RESULTS

After the review process, 15 prospective studies (12 cohorts) were included in the final analysis. These studies included 33,816 nondemented subjects followed for 1-12 years. A total of 3210 patients showed cognitive decline during the follow-up. The cumulative analysis for all the studies under a random-effects model showed that subjects who performed a high level of physical activity were significantly protected (-38%) against cognitive decline during the follow-up (hazard ratio (HR) 0.62, 95% confidence interval (CI) 0.54-0.70; P < 0.00001). Furthermore, even analysis of low-to-moderate level exercise also showed a significant protection (-35%) against cognitive impairment (HR 0.65, 95% CI 0.57-0.75; P < 0.00001).

CONCLUSION

This is the first meta-analysis to evaluate the role of physical activity on cognitive decline amongst nondemented subjects. The present results suggest a significant and consistent protection for all levels of physical activity against the occurrence of cognitive decline.

Examining the association between late-life leisure activity participation and global cognitive decline in community-dwelling elderly Chinese in Hong Kong

OBJECTIVE

This study examines the association between late-life leisure activity participation and global cognitive decline in community-dwelling elderly Chinese in Hong Kong.

METHODS

Five hundred and five participants, not clinically demented at the baseline, were analysed in the follow-up study of a population-based community survey among Hong Kong Chinese aged 60 and over. Information regarding leisure activity participation, global cognitive function and important sociodemographic variables was collected. Late life leisure activity profiles were classified into intellectual, social, physical and recreational categories, and were measured by total hours per week, total frequency and total number of subtypes. Multivariate logistic regression analyses were used to evaluate the association between leisure activity participation at the baseline and the incidence of global cognitive decline at the 22-month follow-up. The incidence of global cognitive decline was defined as a one-point drop in z-score of the Cantonese version of the mini-mental state examination (CMMSE).

RESULTS

At the follow-up, a higher level of participation in intellectual activities was significantly associated with a lower incidence of global cognitive decline as measured by both the total hours per week (multivariate-adjusted OR 0.97 (95% CI 0.94-0.99, p=0.003)), and the total number of subtypes (multivariate-adjusted OR 0.74 (95% CI 0.58-0.95, p=0.018)).

CONCLUSIONS

A higher level of late-life intellectual activity participation was associated with less global cognitive decline among community-dwelling elderly Chinese in Hong Kong.

Religious Participation, Gender Differences, and Cognitive Impairment among the Oldest-Old in China

This study examines if religious participation in China is associated with cognitive functioning among the oldest-old and whether positive psychological feelings and leisure activity engagement explain the association, and gender moderates the association. Logistic regressions were used to analyze the Chinese Healthy Longevity Survey. A significant negative association between religious participation and cognitive impairment was found among the oldest-old and much of the association was mediated by positive psychological feelings and leisure activities. Women reported higher proportion of religious participation, but the cognitive benefits of religious participation were stronger for men. Findings indicate that (a) religious participation is significantly correlated with cognitive functioning in part because the religious oldest-old are more likely to be optimistic and happy and engage in more cognitively stimulating activities; (b) there might be gender differences in religious participation such that the oldest-old men may engage in religious activities that are particularly relevant to cognitive functioning.

Examining the association between participation in late-life leisure activities and cognitive function in community-dwelling elderly Chinese in Hong Kong

BACKGROUND

Growing evidence suggests that participation in late-life leisure activity may have beneficial effects on cognitive function. The objective of the study was to evaluate the association between leisure activity participation and cognitive function in an elderly population of community-dwelling Hong Kong Chinese.

METHODS

512 participants were assessed in the follow-up study of a population-based community survey of the prevalence of cognitive impairment among Hong Kong Chinese aged 60 years and over. Leisure activities were classified into four categories (physical, intellectual, social and recreational). Information regarding leisure activity participation, cognitive function and other variables was collected. Multivariate linear regression analyses were performed to examine the association between leisure activity participation and cognitive function.

RESULTS

A higher level of late-life leisure activity participation, particularly in intellectual activities, was significantly associated with better cognitive function in the elderly, as reflected by the results of the Cantonese Mini-mental State Examination (p = 0.007, 0.029 and 0.005), the Category Verbal Fluency Test (p = 0.027, 0.003 and 0.005) and digit backward span (p = 0.031, 0.002 and 0.009), as measured by the total frequency, total hours per week and total number of subtypes, respectively; the Chinese Alzheimer's Disease Assessment Scale-Cognitive Subscale (p = 0.045) and word list learning (p = 0.003), as measured by the total number of subtypes; and digit forward span (p = 0.007 and 0.015), as measured by the total hours per week and total number of subtypes, respectively.

CONCLUSION

Late-life intellectual activity participation was associated with better cognitive function among community-dwelling Hong Kong elderly Chinese.