The association of single and combined factors of sedentary behavior and physical activity with subjective cognitive complaints among community-dwelling older adults: Cross-sectional study

The Relationship Between Subjective Cognitive Decline and Cognitive Leisure Activity Engagement: A Systematic Review

BACKGROUND AND OBJECTIVES

Subjective cognitive decline (SCD) is a common experience of self-perceived decline without objective cognitive impairment. It has been theorized that SCD is associated with participation in cognitive leisure activities (CLAs), but the evidence base is multifarious and unclear. The purpose of this systematic review was to synthesize current evidence to determine the association between SCD and CLA engagement.

RESEARCH DESIGN AND METHODS

Systematic searches were conducted in EMBASE, MEDLINE, PsycINFO, and Web of Science (last searched April 2023). Data were extracted against a priori inclusion criteria and synthesized narratively using Synthesis without Meta-Analysis guidelines. Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) and Mixed Methods Appraisal Tool (MMAT). Reporting follows PRISMA guidelines.

RESULTS

From 4,447 records, 11 articles were included. Due to study heterogeneity, evidence on SCD and CLA association is inconclusive. Although a modest correlation was found between greater engagement in CLA and fewer reports of SCD, the heterogeneity in study designs and outcomes, particularly in those addressing only perceived memory decline and CLA engagement, challenges definitive conclusions on this relationship. Evidence from mixed-method and qualitative studies indicated that perceived memory decline may cause negative feelings, such as shame and frustration, which may influence participating in CLA.

DISCUSSION AND IMPLICATIONS

These findings suggest that participation in CLA is moderately associated with, and may act protectively against, SCD. However, establishing a directional or causal relationship between CLA participation and SCD outcomes requires further investigation through longitudinal and/or interventional studies.

Subjective Cognitive Impairment and Physical Activity: Investigating Risk Factors and Correlations among Older Adults in Spain

Subjective cognitive impairment in older persons has a substantial influence on their quality of life and can progress to serious illnesses such as dementia. Physical activity level can help prevent cognitive decline and improve cognitive performance. The aim of this study was to investigate the association between frequency of physical activity and subjective cognitive impairment in Spanish adults aged 65 and over, and to identify different risk factors. Using data from the EHSS20 survey, the study focused on 7082 participants who provided information on cognitive impairment and physical activity. Key predictor variables included age, gender, BMI, marital status, and education level. A significant relationship was found between BMI category and gender, with 66.5% of the population being overweight or obese. Men were more likely to be overweight than women. Socio-demographic factors such as educational level, marital status, and physical activity frequency showed dependent associations with sex. Women had a higher prevalence of subjective cognitive impairment than men. A strong association was found between frequency of physical activity and subjective cognitive impairment, with inactive older people having the highest prevalence of subjective cognitive impairment. Older women who engage in little physical exercise and have less education are at risk for subjective cognitive impairment. Furthermore, for both men and women, being overweight was associated with a more reduced risk than obesity. Significant relationships were also discovered between subjective cognitive impairment, frequency of physical exercise, gender, BMI, and degree of education. In conclusion, older, sedentary women with high BMI and less education are more likely to experience subjective cognitive impairment.

Association between Subjective Cognitive Complaints and Sleep Disturbance among Community-Dwelling Elderly Individuals in Japan

Subjective cognitive complaints (SCCs) are a crucial modifiable risk factor for dementia. There is increasing interest in the association between SCC and sleep disturbance; however, the effects of sleep disturbance on SCC development among community-dwelling elderly individuals in Japan remain unclear. We aimed to cross-sectionally investigate the association between SCC and sleep disturbance, with adjustment for multiple factors related to cognitive decline, among 241 community-dwelling elderly persons without cognitive impairment. The measures were SCCs (Kihon Checklist-Cognitive Function, KCL-CF), sleep disturbance (Japanese version of the Athens Insomnia Scale, AIS-J), general cognitive function (Mini-Mental State Examination), and depressive symptoms (five-item version of the Geriatric Depression Scale [GDS-5]). The following data were collected: sex, age, educational history, whether the participants had visited a medical institution for diseases (hypertension, diabetes, hyperlipidemia, heart disease), and the presence/absence of established risk factors (hearing loss, history of head injury, drinking habits, smoking habits, social isolation, and physical inactivity and activity). Based on the KCL-CF, 96 and 145 participants were considered to have and lack SCCs, respectively. On logistic regression analysis, the AIS-J score and smoking history were significantly associated with SCCs. Our findings suggest that sleep disturbance is associated with SCC development among community-dwelling elderly people in Japan. Evaluating and managing sleep disturbances can be important in preventing SCCs and dementia.

Association Between Subjective Cognitive Decline and Twice-Weekly Muscle-Strengthening Activities in Middle-Aged and Older US Adults: An Analysis of the 2019 Behavioral Risk Factor Surveillance System

PURPOSE

Adults with subjective cognitive decline (SCD), the self-reported concern of reduced cognitive function, are recommended to do physical activity for its brain health benefits. US adults aged ≥45 with SCD are less likely to meet the American College of Sports Medicine (ACSM) aerobic activity recommendations. Their engagement in muscle-strengthening activities is unknown. We aimed to identify if US adults aged ≥45 with SCD are less likely to do twice-weekly muscle-strengthening activities compared to those without SCD.

DESIGN

Secondary analysis of the 2019 Behavioral Risk Factor Surveillance System (BRFSS) data.

SAMPLE

114 164 respondents, representing approximately 59 million US adults aged ≥45.

MEASURES

SCD was indicated if the respondent reported confusion or memory loss during the past 12 months (yes/no). Respondents reported the frequency of muscle-strengthening activities, which we categorized as meeting the ACSM's recommendations (2+ times per week) or not (<2 times per week).

ANALYSIS

Crude and adjusted logistic regression models controlling for variables associated with SCD and muscle-strengthening activities. The models used sample weights to represent US adults in the included 31 states and Washington D.C.

RESULTS

US adults aged ≥45 with SCD were less likely to do twice-weekly muscle-strengthening activities than those without SCD (28.6% [SE: .8%] vs 33.5% [SE: .3%], adjusted OR, .9; 95% CI: .9-1.0).

CONCLUSION

Primary care providers should encourage middle-aged and older patients to engage in muscle-strengthening and aerobic activities.

Domains of Sedentary Behavior and Cognitive Function: The Health, Aging, and Body Composition Study, 1999/2000 to 2006/2007

BACKGROUND

This study examines the relationship between various domains of sedentary behavior and subsequent cognitive function to evaluate whether different sedentary activities have specific associations with future cognitive performance.

METHODS

Data were from 1 261 older adults participating in the Health, Aging, and Body Composition (Health ABC) Study between 1999/2000 and 2006/2007. Total sitting time (hours/day), reading time (hours/week), and TV time (≤27/≥28 h/wk) were self-reported at baseline and 3 years later. At follow-up, cognitive function was evaluated using the Teng Mini-Mental State Examination (3MS) and the Digit Symbol Substitution Test (DSST). Multivariable linear regression modeling examined the independent associations of baseline sedentary behaviors and 3-year change in those behaviors with cognitive function scores at follow-up, adjusting for important covariables.

RESULTS

Baseline total sitting time was positively associated with 3MS (β = 0.14 ± 0.07; p < .05) and DSST (β = 0.20 ± 0.10; p < .05) scores at follow-up, as was reading time (β = 0.09 ± 0.03; p < .05 for 3MS score and β = 0.14 ± 0.04; p < 0.01 for DSST score). Participants who increased their TV watching time over 3 years had a significantly lower 3MS score (β = -1.45 ± 0.71; p < .05) at follow-up, compared with those who maintained a low level of TV time (referent). These findings were independent of age, sex, race, education level, health status, depressive symptoms, and physical activity.

CONCLUSION

Some types of sedentary behavior may have benefits for cognitive function in older age, thus highlighting the importance of measuring different domains of sitting time.

Association between sedentary behavior and risk of cognitive decline or mild cognitive impairment among the elderly: a systematic review and meta-analysis

Background

Existing evidence on the association between sedentary behavior (SB) and cognitive function remains inconclusive. Therefore, this study investigated the association between SB and the risk of cognitive decline (CD) or mild cognitive impairment (MCI) in the elderly.

Methods

A comprehensive search was independently conducted by two researchers (XC and GQ) in seven electronic databases, including Medline (via PubMed), China Biology Medicine, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang database, and VIP database for Chinese technical periodicals, covering studies published from the inception of database to June 2023. Studies that investigated the relationship between SB and the risk of CD or MCI in the elderly were included. The quality of the literature was assessed using the Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) assessment tools. The combined effect size analysis, subgroup analysis, and publication bias assessment were performed using STATA 14.0.

Results

A total of 13 cross-sectional and 6 cohort studies involving 81,791 individuals were included, comprising 17 high-quality studies and 2 medium-quality studies. We found that SB was significantly associated with an increased risk of CD [odds ratio (OR) = 1.69, 95% confidence intervals (CI): 1.47-1.94] or MCI (OR = 1.34, 95% CI: 1.14-1.56) among the elderly. Subgroup analysis stratified according to comorbidity, lifestyle, family structure, publication year, and region showed statistical differences between groups, and the consistency of the results revealed the sources of the heterogeneity.

Conclusion

This meta-analysis showed that SB is positively associated with the risk of CD or MCI in the elderly, providing a higher level of evidence for the promotion of healthy behaviors by clinicians and health policymakers. Due to the number and quality of the included articles, more high-quality longitudinal studies are needed to further confirm our findings.

Total Sedentary Time and Cognitive Function in Middle-Aged and Older Adults: A Systematic Review and Meta-analysis

Background

An estimated 47 million people have dementia globally, and around 10 million new cases are diagnosed each year. Many lifestyle factors have been linked to cognitive impairment; one emerging modifiable lifestyle factor is sedentary time.

Objective

To conduct a systematic review and meta-analysis of peer-reviewed literature examining the association between total sedentary time with cognitive function in middle-aged and older adults under the moderating conditions of (a) type of sedentary time measurement; (b) the cognitive domain being assessed; (c) looking at sedentary time using categorical variables (i.e., high versus low sedentary time); and (d) the pattern of sedentary time accumulation (e.g., longer versus shorter bouts). We also aimed to examine the prevalence of sedentary time in healthy versus cognitively impaired populations and to explore how experimental studies reducing or breaking up sedentary time affect cognitive function. Lastly, we aimed to conduct a quantitative pooled analysis of all individual studies through meta-analysis procedures to derive conclusions about these relationships.

Methods

Eight electronic databases (EMBASE; Web of Science; PsycINFO; CINAHL; SciELO; SPORTDiscus; PubMed; and Scopus) were searched from inception to February 2021. Our search included terms related to the exposure (i.e., sedentary time), the population (i.e., middle-aged and older adults), and the outcome of interest (i.e., cognitive function). PICOS framework used middle-aged and older adults where there was an intervention or exposure of any sedentary time compared to any or no comparison, where cognitive function and/or cognitive impairment was measured, and all types of quantitative, empirical, observational data published in any year were included that were published in English. Risk of bias was assessed using QualSyst.

Results

Fifty-three studies including 83,137 participants met the inclusion criteria of which 23 studies had appropriate data for inclusion in the main meta-analysis. The overall meta-analysis suggested that total sedentary time has no association with cognitive function (r = −0.012 [95% CI − 0.035, 0.011], p = 0.296) with marked heterogeneity (I² = 89%). Subgroup analyses demonstrated a significant negative association for studies using a device to capture sedentary time r = −0.035 [95% CI − 0.063, − 0.008], p = 0.012). Specifically, the domains of global cognitive function (r = −0.061 [95% CI − 0.100, − 0.022], p = 0.002) and processing speed (r = −0.067, [95% CI − 0.103, − 0.030], p < 0.001). A significant positive association was found for studies using self-report (r = 0.037 [95% CI − 0.019, 0.054], p < 0.001). Specifically, the domain of processing speed showed a significant positive association (r = 0.057 [95% CI 0.045, 0.069], p < 0.001). For prevalence, populations diagnosed with cognitive impairment spent significantly more time sedentary compared to populations with no known cognitive impairments (standard difference in mean = −0.219 [95% CI − 0.310, − 0.128], p < 0.001).

Conclusions

The association of total sedentary time with cognitive function is weak and varies based on measurement of sedentary time and domain being assessed. Future research is needed to better categorize domains of sedentary behaviour with both a validated self-report and device-based measure in order to improve the strength of this relationship. PROSPERO registration number: CRD42018082384.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00507-x.

Psychological-health correlates of physical activity and sedentary behaviour during the COVID pandemic

BACKGROUND

While physical inactivity is associated with adverse psychological outcomes, less is known about the psychological outcomes associated with sedentary behaviour, and specifically, its mentally active and passive forms. The COVID-19 pandemic represents a unique opportunity to study associations between these variables in light of widespread stay-at-home mandates and restrictions on outdoor exercise/social activities. Using a cross-sectional dataset acquired during the COVID-19 pandemic in Australia, we examined whether physical activity and sedentary behaviour were associated with subjective quality of life (sQoL) and subjective cognitive dysfunction, and whether these associations were mediated by depressive symptoms.

METHODS

658 participants (males = 169, females = 489) self-reported data on physical activity and sedentary behaviour in an online survey during May 2020-May 2021. Data on physical activity and sedentary behaviour (both mentally active and passive types) was compared according to whether it was collected during or out of a lockdown period. Regression models were used to test associations of physical activity and sedentary behaviour with sQoL and subjective cognitive dysfunction, and whether these associations were mediated by depression severity.

RESULTS

Physical activity was beneficially associated with sQoL, whereas sedentary behaviour (both total hours and the reduction of mentally active/increase in mentally passive behaviour) was detrimentally associated with sQoL. These associations were mediated by depression severity. Physical activity and sedentary behaviour were also indirectly associated with subjective cognitive dysfunction by virtue of their associations with depression severity.

CONCLUSIONS

There are important differences in the psychological correlates of mentally passive and active sedentary behaviours. Our findings suggest that health promotion strategies should focus on not only increasing physical activity but also reducing passive sedentary behaviours as a means of maintaining good psychological health.

Leisure-time sedentary behaviors are differentially associated with all-cause dementia regardless of engagement in physical activity

Sedentary behavior (SB) is associated with cardiometabolic disease and mortality, but its association with dementia is currently unclear. This study investigates whether SB is associated with incident dementia regardless of engagement in physical activity (PA). A total of 146,651 participants from the UK Biobank who were 60 years or older and did not have a diagnosis of dementia (mean [SD] age: 64.59 [2.84] years) were included. Self-reported leisure-time SBs were divided into two domains: time spent watching television (TV) or time spent using a computer. A total of 3,507 individuals were diagnosed with all-cause dementia over a mean follow-up of 11.87 (±1.17) years. In models adjusted for a wide range of covariates, including time spent in PA, time spent watching TV was associated with increased risk of incident dementia (HR [95% CI] = 1.24 [1.15 to 1.32]) and time spent using a computer was associated with decreased risk of incident dementia (HR [95% CI] = 0.85 [0.81 to 0.90]). In joint associations with PA, TV time and computer time remained significantly associated with dementia risk at all PA levels. Reducing time spent in cognitively passive SB (i.e., TV time) and increasing time spent in cognitively active SB (i.e., computer time) may be effective behavioral modification targets for reducing risk of dementia regardless of engagement in PA.

Longitudinal Association Between Oral Status and Cognitive Decline Using Fixed-effects Analysis

BACKGROUND

Although the feasibility of randomized trials for investigating the long-term association between oral health and cognitive decline is low, deriving causal inferences from observational data is challenging. We aimed to investigate the association between poor oral status and subjective cognitive complaints (SCC) using fixed-effects model to eliminate the confounding effect of unobserved time-invariant factors.

METHODS

We used data from Japan Gerontological Evaluation Study (JAGES) which was conducted in 2010, 2013, and 2016. β regression coefficients and 95% confidence intervals [CIs] were calculated using fixed-effects models to determine the effect of deteriorating oral status on developing SCC. Onset of SCC was evaluated using the Kihon Checklist-Cognitive function score. Four oral status variables were used: awareness of swallowing difficulty, decline in masticatory function, dry mouth, and number of teeth.

RESULTS

We included 13,594 participants (55.8% women) without SCC at baseline. The mean age was 72.4 (standard deviation [SD], 5.1) years for men and 72.4 (SD, 4.9) years for women. Within the 6-year follow-up, 26.6% of men and 24.9% of women developed SCC. The probability of developing SCC was significantly higher when participants acquired swallowing difficulty (β = 0.088; 95% CI, 0.065-0.111 for men and β = 0.077; 95% CI, 0.057-0.097 for women), decline in masticatory function (β = 0.039; 95% CI, 0.021-0.057 for men and β = 0.030; 95% CI, 0.013-0.046 for women), dry mouth (β = 0.026; 95% CI, 0.005-0.048 for men and β = 0.064; 95% CI, 0.045-0.083 for women), and tooth loss (β = 0.043; 95% CI, 0.001-0.085 for men and β = 0.058; 95% CI, 0.015-0.102 for women).

CONCLUSION

The findings suggest that good oral health needs to be maintained to prevent the development of SCC, which increases the risk for future dementia.

Sleep problems and subjective cognitive complaints among middle-aged and older adults in 45 low- and middle-income countries

BACKGROUND

Currently, a small body of evidence suggests that sleep problems are positively associated with subjective cognitive complaints (SCC). However, no studies on this topic exist from low- and middle-income countries (LMICs). Thus, we investigated the association between sleep problems and SCC in a large sample of middle-age and older adults from 45 LMICs.

METHODS

Cross-sectional, predominantly nationally representative, community-based data were analyzed from the World Health Survey. Sleep problems (such as difficulties falling asleep, waking up frequently during the night or waking up too early in the morning) in the last 30 days were self-reported. Two questions on subjective memory and learning complaints in the past 30 days were used to create a SCC scale ranging from 0 (No SCC) to 100 (worse SCC). Multivariable linear regression was conducted to explore the association between sleep problems (exposure) and SCC (outcome).

RESULTS

Data on 60,228 adults aged ≥ 50 years were analyzed [mean (SD) age 61.4 (9.9) years; 53.9% females]. After adjustment for potential confounders, compared to those without sleep problems, the mean SCC score for the multivariable model was 13.32 (95% CI 12.01, 14.63), 19.46 (95% CI 17.95, 20.98), 24.17 (95% CI 22.02, 26.33), and 31.39 (95% CI 28.13, 34.65) points higher for mild, moderate, severe, and extreme sleep problems, respectively. Similar results were found for analyses stratified by age and country-income level.

CONCLUSION

Sleep problems were positively associated in a dose-response manner with SCC among middle-aged and older adults in multiple LMICs. Addressing sleep problems may aid in the prevention of SCC and ultimately dementia, pending future longitudinal research.

Do the impacts of mentally active and passive sedentary behavior on dementia incidence differ by physical activity level? A 5-year longitudinal study

BACKGROUND

It has not been determined whether mentally active sedentary behavior (MASB) and passive sedentary behavior (PSB) differentially affect cognitive function, and whether these associations differ according to physical activity (PA) level. We examined the comparative impacts of MASB and PSB on dementia onset and aimed to understand whether the associations differed by PA level.

METHODS

A 5-year longitudinal study involving all community-dwelling older adults in a rural area in Japan (n = 5,323). Dementia onset was examined using long-term care insurance data. PA was evaluated using the International Physical Activity Questionnaire and categorized as low (<2.5 MET-h/week), moderate (<16.0 MET-h/week), or high (≥16.0 MET-h/week). We also assessed PSB (TV-watching time; <1 h/day, <3 h/day, ≥3 h/day) and MASB (Book-reading time; <10 min/day, <30 min/day, ≥30 min/day). To examine the associations of MASB and PSB with dementia onset, we performed the Fine-Gray models accounting for competing risk of death.

RESULTS

During the follow-up period, 606 (11.4%) participants developed dementia. MASB was independently associated with a lower risk of dementia; the magnitude of the impact was significant at higher PA levels. There was no association between PSB and developing dementia across all PA levels. Furthermore, dementia risk for individuals with high PA levels and moderate or high MASB levels was approximately 60% lower than those with low PA levels and low MASB.

CONCLUSIONS

Providing interventions to promote MASB, which reduces dementia risk, and PA, which increases MASB's effect on dementia incidence, can be beneficial in delaying or preventing dementia onset.

A mini-flipped, game-based Mediterranean diet learning program on dietary behavior and cognitive function among community-dwelling older adults in Taiwan: A cluster-randomized controlled trial

The Mediterranean diet has been recommended to delay cognitive decline, but adherence to the diet among older adults remain poor, and research on interventions that effectively promote the diet has been inconclusive. This study examined the effects of a mini-flipped, game-based Mediterranean diet learning program in improving dietary behavior and cognitive function in community-dwelling older adults in Taiwan. A cluster randomized controlled trial was conducted. The experimental group completed an 8-week, mini-flipped, game-based learning program. Data were collected at baseline and 8 weeks after intervention. Outcome measures included dietary behavior, global cognitive function, and subjective cognitive dysfunction. Compared with the control group, the experimental group exhibited significantly improved Mediterranean diet behavior and global cognitive function after the intervention, although there was no significant difference in subjective cognitive function. Future research should be conducted with larger populations and longer-term follow-up to evaluate the effect of this learning program.

Association between sedentary time and cognitive function: A focus on different domains of sedentary behavior

Studies which examined the association between sedentary behavior (SB) and cognitive function have presented equivocal findings. Mentally active/inactive sedentary domains may relate differently to cognitive function. We examined associations between SB and cognitive function, specifically focusing on different domains. Participants were recruited from the Nijmegen Exercise Study 2018 in the Netherlands. SB (h/day) was measured with the Sedentary Behavior Questionnaire. Cognitive function was assessed with a validated computer self-test (COST-A), and a z-score calculated for global cognitive function. Multivariate linear regression assessed associations between tertiles of sedentary time and cognitive function. Cognition tests were available from 2821 participants, complete data from 2237 participants (43% female), with a median age of 61 [IQR 52-67] and a mean sedentary time of 8.3 ± 3.2 h/day. In fully adjusted models, cognitive function was significantly better in participants with the highest total sedentary time (0.07 [95% CI 0.02-0.12], P = 0.01), work-related sedentary time (0.13 [95% CI 0.07-0.19], P < 0.001), and non-occupational computer time (0.07 [95% CI 0.02-0.12], P = 0.01), compared to the least sedentary. Leisure sedentary time and time spent sedentary in the domains TV, reading or creative time showed no association with cognitive function in final models (all P > 0.05). We found a strong, independent positive association between total SB and cognitive function in a heterogenous population. This relation was not consistent across different domains, with especially work- and computer-related SB being positively associated with cognitive function. This highlights the importance of assessing the various sedentary domains in understanding the relation between sedentary time and cognitive function.

Traditional Thai exercise (Ruesi Dadton) for improving motor and cognitive functions in mild cognitive impairment: a randomized controlled trial

This study determined the effectiveness of a 12-week cycle of Ruesi Dadton (RSD) among older adults with mild cognitive impairment (MCI), for improving cognitive and physical performance. Seventy-six participants were included and were divided equally into two groups. A group performed RSD exercise for 60 min, 3 times/wk for 12 weeks, and the control group did not perform RSD exercise. The primary endpoint was cognitive function, as assessed by the Montreal cognitive assessment (MoCA), Mini-Mental State Examination, verbal fluency (VF) test, and trail making test parts A and B (TMT-A and TMT-B). The secondary endpoints were the Timed Up and Go (TUG) test, handgrip, and gait speed results, which were used to evaluate the physical function. There were significant differences in the TMT-B and handgrip scores (P<0.05) between the two groups. Both groups had improved MoCA scores (P<0.05) and normal walking speeds (P<0.01). Additionally, the RSD group showed improved VF test (P<0.01), TMT-B (P<0.01), and TUG test (P<0.05); a negative correlation was found between MoCA and TUG test (P<0.05). However, high walking speed and handgrip (P<0.05) worsened in the control group. RSD exercise resulted in relevant improvements in the cognitive and physical functions in MCI.

Sitting Time, Physical Activity, and Cognitive Impairment in Midlife and Older Adults

This study cross-sectionally examines the relations of sitting and physical activity (PA) with cognitive impairment in community-dwelling adults aged 55-87 years (n = 3,780). Multivariable logistic regression assessed independent and joint relations of sitting and PA with Montreal Cognitive Assessment scores adjusting for covariates. Sitting ≥75% of the time and not meeting PA guidelines were related to 60% (95% confidence interval [CI] [1.19, 2.17]) and 27% (95% CI [1.06, 1.53]) higher odds for cognitive impairment, respectively. Stratification by age showed that sitting ≥75% of the time was associated with higher cognitive impairment odds in midlife (odds ratio [OR] = 1.86; 95% CI [1.31, 2.65]), but not older adults (OR = 1.06; 95% CI [0.57, 1.95]). Joint association analysis revealed that, overall, the highest odds for cognitive impairment were in those sitting ≥75% of the time while meeting or not meeting PA guidelines (OR = 1.69, 95% CI [1.13, 2.53]; and OR = 1.66, 95% CI [1.19, 2.32], respectively). In conclusion, prolonged sitting and insufficient PA are independent risk markers for cognitive impairment.

Understanding Variations in the Health Consequences of Sedentary Behavior: A Taxonomy of Social Interaction, Novelty, Choice, and Cognition

The study of sedentary behaviors requires taxonomies (classification schemes) to standardize data collection, measurements, and outcomes. Three taxonomies of sedentary behaviors have been identified, but none address an important challenge in sedentary behavior research, which is to distinguish between beneficial and detrimental health effects of various sedentary behaviors. Some sedentary behaviors (e.g., reading) are associated with positive health outcomes, whereas other sedentary behaviors (e.g., television viewing) are associated with adverse health outcomes. To address directly this complexity and present a different conception and understanding of discrepant findings related to health outcomes, a new taxonomy is needed. The development of the new taxonomy is guided by analysis of literature and selection of a relevant and informative behavioral sciences theoretical framework (i.e., self-determination theory). Because older adults are an increasing percentage of the population and report a high prevalence of sedentary behaviors, the new taxonomy was designed for older adults with potential application to all age groups. Taylor's taxonomy of sedentary behaviors is parsimonious with four domains: social interaction (i.e., not solitary, companionship, interacting, and connecting with others); novelty (i.e., refreshingly new, unusual, or different); choice (i.e., volition, preferred option or alternative, the power, freedom, or decision to choose); and cognition (i.e., mentally stimulating and engaging).

Associations between activity fragmentation and subjective memory complaints in middle-aged and older adults

INTRODUCTION

Subjective memory complaints (SMC) are often considered a clinical marker of mild cognitive impairment and dementia and could manifest as shortening of activity bouts throughout the day causing daily activity to accumulate in a more fragmented pattern. In the current study we explored the association between activity fragmentation and SMC in middle-aged and older adults.

METHODS

We used data from 3820 participants in the National Health and Nutrition Examination Survey (2003-2006) with valid accelerometer SMC data. The analyses were conducted in 2020. To calculate activity fragmentation, an active-to-sedentary transition probability was calculated as the number of physical activity bouts (i.e., consecutive minutes registering 100+ counts/min) divided by the total sum of minutes spent in physical activity. A multivariable ordinal logistic regression model was conducted to examine the association between activity fragmentation (scaled) and SMC (yes/no).

RESULTS

Higher activity fragmentation was associated with an increased likelihood of self-reported SMC in the study population (Odd Ratio [95% Confidence Interval] = 1.335 [1.067, 1.669]; Average Marginal Effect [95%CI] = 0.029 [0.006, 0.052]; p-value = 0.021). This association was independent of total physical activity volume.

CONCLUSIONS

The findings provide support that studying fragmented activity patterns can be useful in identifying those at risk for SMC, over and above total volume of physical activity. Future longitudinal studies are required to establish causality and the temporal order of the observed association. Nevertheless, activity fragmentation in middle-aged and older adults may reflect pre-clinical signs of future neurodegenerative processes indicating potential targets for modification through intervention.

The Relationship between Subjective Cognitive Decline and Health Literacy in Healthy Community-Dwelling Older Adults

Few studies have examined the effects of health literacy on people at risk of developing dementia; its effects on the pathogenesis of subjective cognitive decline (SCD) are particularly unclear. This study aimed to clarify the relationship between health literacy and SCD in a population of healthy community-dwelling older adults. SCD status was assessed using the Cognitive Function domain of the Kihon Checklist (KCL-CF). Health literacy, in turn, was evaluated using the Communicative and Critical Health Literacy (CCHL) scale. Global cognitive function and depressive symptoms were evaluated using the Mini-Mental State Examination (MMSE) and a five-item version of the Geriatric Depression Scale (GDS-5), respectively. Participants who were suspected of having SCD were significantly older than their non-SCD peers, and scored significantly worse on the CCHL, MMSE, and GDS-5. In addition, SCD status was found to be associated with CCHL and GDS-5 scores, as well as age, according to a logistic regression analysis. These findings suggest that low health literacy is linked to SCD morbidity in healthy community-dwelling older adults and should prove useful in the planning of dementia prevention and intervention programs for this population.

Sensor-measured sedentariness and physical activity are differentially related to fluid and crystallized abilities in aging

Aerobic exercise and physical activity (PA) are known to benefit cognition in adulthood. However, a typical older adult spends most of the day sedentary or in light PA, behaviors that are typically poorly captured by questionnaires. To better understand the associations between time spent in different intensities of lifestyle PA and cognition, we measured average time spent daily in sedentariness, light, and moderate to vigorous PA using hip-worn sensors (ActiGraph accelerometers). We studied baseline data from 228 cognitively normal adults (Age 60-80) who took part in a clinical trial (clinical study identifier: NCT01472744). Fluid (processing speed, memory, and reasoning) and crystallized abilities (vocabulary knowledge) were assessed with the Virginia Cognitive Aging Battery. Adjusting for age, sex, and several modifiable socioeconomic, physical and functional health factors, time spent daily in moderate to vigorous PA was positively related with fluid abilities (perceptual speed and reasoning). Furthermore, we found that those spending more time sedentary performed better on vocabulary knowledge and reasoning tasks. In contrast, time spent in light PA was not related to either fluid or crystallized abilities. Our results add to the previous literature by providing the first sensor-based evidence that crystallized and fluid abilities in older age may be associated with engagement in different intensities of daily activity. Moreover, our findings suggest that the behavior of moderate to vigorous PA is at least as important in relation to cognition as the desirable long-term physiological effects of higher intensity PA and exercise. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Daily lifestyle behaviors and risks of sarcopenia among older adults

BACKGROUND

Lifestyle behaviors are modifiable factors that can provide information for designing intervention strategies for sarcopenia. The present study aimed to identify the relationships between a range of daily lifestyle behaviors and sarcopenia risks among older adults.

METHODS

A nationwide telephone-based survey targeting older adults (≥65 years) was performed in Taiwan. Data based on self-reported daily lifestyle behaviors (food selection, physical activity, sitting time, and sleep duration), the presence or absence of sarcopenia (measured by SARC-F), and personal characteristics were obtained. Binary logistic regression models were applied.

RESULTS

A total of 1068 older adults participated in this survey. In the adjusted model, older adults who selected unbalanced foods (odds ratio [OR] = 1.93, 95% confidence interval [CI] = 1.12-3.34), engaged in insufficient physical activity (OR = 5.14, 95% CI = 3.04-8.70), and sat for longer periods of time (OR = 1.98, 95% CI = 1.09-3.59) were more likely to have higher risks of sarcopenia. No significant association was observed for sleep duration.

CONCLUSIONS

The results of this study highlight that, among health behaviors, an unbalanced food selection (six nutrients), not meeting physical activity recommendations (150 min/week), and a higher sitting time (≥7 h/day) were risk factors for sarcopenia among older adults. Intervention programs for sarcopenia prevention in older adults should focus on promoting balanced food selection, sufficient physical activity, and reduced sitting time.

Longitudinal associations of social group engagement with physical activity among Japanese older adults

BACKGROUND

Although social group engagement (SGE) has been suggested to affect physical activity (PA) in older age, the longitudinal relationship between these variables is unclear. This study used 2-year panel data to investigate the link between changes in SGE and changes in PA among community-dwelling older adults.

METHODS

This study was a 2-year community-based longitudinal study enrolling older adults living in a rural municipality in Japan. The subjects were all residents in the study area aged ≥ 65 at the baseline. Mail surveys were administered in 2016 and 2018. The 3688 subjects responding to both surveys were included in the analyses. PA was evaluated with the International Physical Activity Questionnaire, and weekly time and metabolic equivalent were computed. SGE was assessed in each wave and classified as consistent engagement (engagement reported in both surveys), new engagement (non-engagement at baseline and engagement at follow-up), leaving the group (engagement at baseline and non-engagement at follow-up), and consistent non-engagement (non-engagement in both surveys). Analysis of covariance was performed to examine the associations of changes in SGE with changes in PA.

RESULTS

Compared with those with consistent non-engagement, who showed declines in every PA category, subjects with consistent engagement or new engagement showed significantly smaller changes in total PA, moderate-intensity PA, and brisk walking. Leaving the group (vs. consistent non-engagement) was associated with maintaining moderate-intensity PA.

CONCLUSIONS

SGE helps to suppress the age-associated decline in PA in older age, with new engagement and continuous engagement, especially, mitigating decreasing PA.

Subjective and Objective Mental and Physical Functions Affect Subjective Cognitive Decline in Community-Dwelling Elderly Japanese People

Subjective cognitive decline (SCD) is complex and not well understood, especially among Japanese people. In the present study, we aimed to elucidate the relationships of subjective and objective mental and physical function with SCD among older community-dwelling Japanese adults. SCD was evaluated using the Kihon Checklist: Cognitive Function. Other parameters were evaluated using the Mini-Mental State Examination (MMSE) and the five-item version of the Geriatric Depression Scale (GDS-5), for an objective mental function other than SCD. A timed up-and-go test (TUG) and knee extension strength were used to test objective physical function, and the Mental Component Summary (MCS) and Physical Component Summary (PCS) in the Health-Related Quality of Life survey eight-item short form (SF-8) were used for subjective mental and physical functions. The results of the MMSE, GDS-5, TUG, knee extension strength, and MCS were significantly worse in the SCD group. In addition, logistic regression analysis showed that GDS-5 and MCS were associated with SCD onset. Depressive symptoms and decreased subjective mental function contribute to SCD among community-dwelling Japanese adults. These findings will be useful for planning dementia prevention and intervention programs for older Japanese adults.

Sedentary behaviours, cognitive function, and possible mechanisms in older adults: a systematic review

BACKGROUND

Physical activity can improve cognitive function of older adults, but the influence of sedentary behaviour on cognition is less clear. This systematic review investigated associations between sedentary behaviour and cognitive function in older adults without dementia, and possible mechanisms involved.

METHODS

Major databases were searched for studies in English between 01/01/1999 and 31/10/2019. The systematic review followed COSMOS-E guideline and a pre-registered protocol (CRD42019122229). Risk of bias was assessed using NICE Quality appraisal checklist. Findings were narratively synthesized and presented.

FINDINGS

Eighteen studies comprised of 13 cross-sectional and five longitudinal analyses (n = 40,228). Evidence suggested varied associations between varied sedentary behaviours and cognitive function in older adults. 50% of study analyses did not control for physical activity. 3/18 studies demonstrated associations between higher sedentary levels and lower levels of brain biomarkers, while 1/18 showed auto-regulatory effect in the left hippocampus. Conducting a meta-analysis was not justifiable due to considerable methodological, participant, outcome and exposure heterogeneity.

CONCLUSION

There is a lack of clarity about the overall and independent association between sedentary behaviour and cognition in older age. Underlying mechanisms are similar to physical activity and probably multi-modal. More studies with robust designs and methodology are needed to confirm effect of sedentary behaviour on cognition.