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Background The hippocampus is a brain structure important for memory and cognitive function. Physical activity may help prevent hippocampal atrophy. However, few studies have measured sedentary behavior (SB) and intensity-specific physical activity using an accelerometer. This study aimed to examine the cross-sectional associations of objectively-determined SB, light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) measured by an accelerometer with hippocampal volume among community-dwelling older adults using compositional data analysis (CoDa) approach. Methods This cross-sectional study was part of the Neuron to Environmental Impact across Generations (NEIGE) study. A randomly recruited sample of 485 Japanese older adults (47% male; aged 65-84 years) wore tri-axial accelerometers (Omron Healthcare) for seven consecutive days in 2017. Hippocampal volume was measured with magnetic resonance imaging and the left and right hippocampal volumes were automatically segmented using FreeSurfer software. Associations of sedentary and physically active behaviors with hippocampal volume were examined with compositional linear regression analysis based on isometric log-ratio transformations of time use adjusted for potential confounding factors. Results The relative proportion of time spent in MVPA, compared to the other two activities, was significantly positively associated with right hippocampal volume (β: 57.1, p-value = 0.027).However, no association existed between higher proportions of MVPA and left hippocampal volume, or between proportions of SB or LPA with either left or right hippocampal volumes. Conclusions The proportion of time spent in MVPA, relative to the other two activities, was significantly positively associated with right hippocampal volume. MVPA may be beneficial for maintaining hippocampal volume.

This longitudinal study aimed to investigate how psychological distress levels changed from early to middle phases of the new coronavirus (COVID-19) pandemic depending on the living arrangements of individuals.An internet-based, longitudinal survey of 2,400 Japanese people was conducted every 5-6 weeks between February 2020 and January 2021. The presence of severe psychological distress (SPD) was measured using the Kessler's psychological distress scale. Living arrangements were classified into two groups (ie, living alone or living with others). Mixed-effects logistic regression analysis was performed to assess whether changes in SPD status were different depending on living arrangements.Of 2,400 respondents, 446 (18.5%) lived alone. Although the proportion of SPD in both individuals living alone and those living with others increased to the same extent in the early phase of the pandemic, the distress levels decreased after the early phase of the pandemic in the group living with others, compared with the group living alone, for which SPD remained high. The odds ratio (OR) of developing SPD in interaction term with survey phases tended to be higher among those who lived alone than those who lived with others in Phase 6 (OR 1.89; 95% confidence interval [CI], 0.99-3.64) and Phase 7 (OR 1.88; 95% CI, 0.97-3.63).During the COVID-19 pandemic, those living alone are persistently at a higher risk of SPD compared to those living with others. Effective countermeasures targeting those living alone, such as enhancing online communication or providing psychological therapies, are essential.

Background: Previous research has established that women accumulate less moderate-to-vigorous physical activity (MVPA) than men. To date, however, little is known about the gender differences in device-based activity patterns of sedentary behavior (SB) and light-intensity physical activity (LPA). We aimed to compare time spent in SB and different intensities of physical activity taking into account of co-dependence of time use domains. Methods: This cross-sectional study was conducted in Suttu town, Hokkaido, Japan. Data were analyzed from 634 Japanese adults (278 men, aged 19-92 years) who provided valid accelerometer (HJA-750C) data. Gender differences in activity behavior patterns were tested using multivariate analysis of covariance (MANCOVA) based on isometric log-ratio transformations of time use, adjusting for age. We also developed bootstrap percentile confidence intervals (CI) to support the interpretation of which behavior differed between genders. Results: Overall, participants had percent time spent in SB, LPA, MVPA during wearing time (mean, 14.8 hours) corresponding to 53.9%, 41.7%, and 4.4% of wearing time, respectively. Activity behavior patterns differed significantly between genders after controlling for time spent in all activities. Women spent relatively 13.3% (95% CI, 9.9-15.9%) less time in SB and 19.8% (95% CI, 14.9-24.6%) more time in LPA compared to men. The difference of time spent in MVPA was not statistically significant. Conclusions: In contrast with previous studies, our findings suggest that Japanese women are more physically active than men when all intensities of activities are considered. Given the health benefits of LPA, evaluating only MVPA may disproportionately underestimate the level of physical activity of women.

To reduce vaccine hesitancy, it is important to identify factors that can intervene at the individual or community level. Social capital is a possible factor because it is associated with various vaccine hesitancy, such as for measles and influenza. However, limited studies have explored the association between social capital and vaccination for COVID-19, which is an unprecedented pandemic and infodemic. Therefore, this study aimed to clarify the association between social capital and COVID-19 vaccination during the pandemic. This cross-sectional study used quota sampling for an online-based survey. Participants were asked whether they had previously been vaccinated for COVID-19 and their intention to receive a COVID-19 vaccine booster. Social capital was evaluated using three measures (individual-level civic participation, social cohesion, and reciprocity). Multiple logistic regression analysis was performed to clarify the association between social capital and previous COVID-19 vaccination status as well as intention to receive a COVID-19 booster. Participants were 2,313 individuals, of whom 87.2% had received a COVID-19 vaccine; 72.3% intended to obtain a COVID-19 booster. Individuals with any social capital are more likely to receive a COVID-19 vaccination than those with none (OR: 1.73, 95%CI: 1.18-2.54; OR: 1.58, 95%CI: 1.22-2.05; OR: 3.05, 95%CI: 2.15-4.33). These indicators were also associated with the intention to receive a COVID-19 booster. Thus, our results suggest that among the general public, those with individual-level social capital are more likely to receive a COVID-19 vaccination than those with none. Social capital may be a factor that can reduce vaccine hesitancy during a pandemic.

Background Physical activity (PA) guidelines for early childhood have been established worldwide, and adherence to PA guidelines has been utilized to assess the effectiveness of policies regarding PA promotion. Although there is a Japanese PA guideline for preschoolers, little is known about adherence to this recommendation. This study examined and compared proportions of meeting the Japanese PA guideline among preschoolers. Methods Participants comprised 821 children aged 3-6 years from all 21 preschools and childcare facilities (hereafter collectively "preschools") within Unnan City, Shimane Prefecture, Japan. Data on PA levels were collected through a parent-report questionnaire in accordance with the Japanese PA guideline. This guideline recommends that preschoolers perform PA for at least 60 minutes every day. Analyses included descriptive statistics, chi-squared, and Mann-Whitney's tests to compare adherence to the PA guideline. Results Data of 441 participants from 20 preschools were analyzed. Of these, 292 (66.2%) preschoolers met the PA guideline. Boys (70.2%) showed a significantly higher proportion of meeting the PA guideline than girls (61.2%; P = 0.048). Proportions of meeting the PA guideline among preschool grades were not statistically different. Prevalence rates of meeting the PA guideline among 20 preschools considerably varied from 14.3% to 100% (P = 0.007). Conclusions Two-thirds of preschoolers met the Japanese PA guideline, while adherence to PA recommendations differed between genders. Moreover, there were distinct variations of adherence to PA guideline among preschools. Possible determinants that cause the differences in adherence to the PA guideline at the individual and preschool-levels should be further evaluated.

Background Physical activity can help to protect against cognitive decline in older adults. However, little is known about the potential combined relationships of time spent in sedentary behavior (SB), light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with indices of cognitive health. We examined the cross-sectional associations of objectively-determined sedentary and physically-active behaviors with an indicator of cognitive function decline (CFD) in older adults. Methods A randomly-recruited sample of 511 Japanese older adults (47% male; aged 65-84 years) wore a tri-axial accelerometer (HJA-750C, Omron) for seven consecutive days in 2017. Cognitive function was assessed by interviewers using the Japanese version of Mini-Mental State Examination, with a score of ≤23 indicating CFD. Associations of sedentary and physically-active behaviors with CFD were examined using a compositional logistic regression analysis based on isometric log-ratio transformations of time use, adjusting for potential confounders. Results Forty one (9.4%) of the participants had an indication of CFD. Activity compositions differed significantly between CFD and normal cognitive function (NCF); the proportion of time spent in MVPA was 39.1% lower, relatively to the overall mean composition in those with CFD, and was 5.3% higher in those with NCF. There was a significant beneficial association of having a higher proportion of MVPA relative to other activities with CFD. LPA and SB were not associated with CFD when models were corrected for time spent in all activity behaviors. Conclusions Larger relative contribution of MVPA was favorably associated with an indicator of CFD in older adults.

Background: The present study examined the cluster of domain-specific sedentary behaviors (SBs) and their associations with physical function among community-dwelling older adults to identify the target groups that require intervention for SBs. Methods: A total of 314 older adults who participated in a population-based cross-sectional survey and an on-site functional assessment in Matsudo City in Chiba participated in this study. Participants were asked to report the daily average of 6 domain-specific SBs. To identify the cluster of domain-specific SBs, hierarchical cluster analysis was performed using the Ward method. Analysis of covariance adjusted for sociodemographic factors, exercise habit, chronic disease, and total SB time was performed to examine the associations between each cluster and physical functional status. Results: The average age of the participants was 74.5 (5.2) years. The 4 clusters identified were leisure cluster, low cluster, work and personal computer use cluster, and television viewing cluster. The analysis of covariance adjusted for covariates showed that grip strength (P = .01), maximum walking speed (P = .03), and 1-leg standing time (P = .03) were significantly poorer in the television viewing cluster than other clusters. Conclusions: It has been concluded that the television viewing group identified as a high-risk group of physical functional decline; therefore, interventions targeting this group are needed to prevent physical functional decline.

Background: Differences in accelerometer-measured sedentary behavior and different physical activity (PA) intensities between men and women have been poorly described. The authors examined gender differences in time-use activity composition and total volume of PA. Methods: A cross-sectional mail survey was conducted from 2013 to 2015 with a randomized sample of 6000 middle-aged (40–64 y) community-dwelling Japanese adults living in urban and regional cities. Participants wore Active style Pro HJA-350IT on their waist for 7 consecutive days. Gender differences in activity time use was examined using compositional data analysis to control for time spent in all activity measures. Results: In total, 757 participants (303 men, 52.3 [7.1] y) with valid data were included in the analysis. Women spent on average 12.6% less time in sedentary behavior and 23.4% more time in light-intensity PA than men, whereas no significant difference was found for moderate to vigorous PA. Women accumulated a significantly greater volume of PA than men (17.8 vs 15.0 metabolic equivalent of task h/d). Conclusions: Japanese middle-aged women showed higher levels of PA than men because they spent more time in light-intensity PA. Given the health benefits of light-intensity PA, evaluating only moderate to vigorous PA may lead to an underestimation of women’s participation in PA.

Background The Olympic Games represent an opportunity to create a ‘physical activity legacy’ that promotes physical activity at the population level in the host nations and cities. However, previous studies showed little increase in population-level physical activity following the Olympics. The upsurge of public interest in sports and physical activity participation before the Olympics may diminish rapidly following the Games. We examined the pre-Games effects of the Olympics on Japanese population-level physical activity after the announcement of Tokyo’s successful bid for the 2020 Olympic and Paralympic Games in September 2013. Methods We used publicly available data from serial cross-sectional surveys conducted with nationally or regionally representative samples in Japan seven years before and after the announcement (from 2006–2020). The outcomes were 1) daily step counts and 2) exercise habit prevalence (≥ 30 min/day, ≥ 2 days/week, and over a year) from the National Health and Nutrition Surveys Japan (NHNS-J; 14 time points; aggregated data); and 3) sports participation (at least once a week) from the National Sports-Life Survey conducted every two years (NSLS; eight time points; individual-level data of 18,867 adults) and from the Public Opinion Survey on Sports Participation of Tokyo Residents (POSSP; eight time points; aggregated data). Age- and gender-adjusted regression models were used to estimate changes in the outcomes before and after the announcement. Results There were no significant pre-Games effects of the Olympics on national-level physical activity participation among Japanese adults. Sports participation (56.4% and 57.5%, respectively; P = 0.518), daily steps (6,535 and 6,686 steps/day; P = 0.353), and exercise habit (30.7% and 29.1%, P = 0.309) did not change significantly before and after the announcement. Although an increase in sports participation among Tokyo residents was not found in the NSLS (61.5% and 59.3%, P = 0.227), it was observed in the POSSP (49.1% and 57.7%, P = 0.019). Nonetheless, this increase might not be related to the pre-Games effects since the trend diminished following the announcement. Conclusions Population-level physical activity did not show significant changes until 2020. Realising the physical activity legacy of an Olympics may require strategic promotion and cross-agency partnership implementation in the pre- and post-event period.

Objectives Objectively measured sedentary behavior (SB) on weekdays and weekends has been mainly assessed in white‐collar workers, while data in blue‐collar workers are sparse. Therefore, this study presented the difference in accelerometer‐measured SB levels between weekdays and weekends, stratified by white‐ and blue‐collar occupations. Methods This study was a sub‐analysis of accelerometer data from 73 workers (31 blue‐collar and 42 white‐collar) at a Japanese manufacturing plant. SB was defined as ≤1.5 metabolic equivalents estimated using an accelerometer, and compared between weekdays and weekends by using mixed models adjusted for confounders. The proportion of workers who sat for ≤8 h/day on weekdays and weekends were compared using McNemar's test. Results In white‐collar workers, SB time on weekdays was significantly longer than that on weekends (598 vs 479 min/day, P .99). Conclusions White‐collar workers were exposed to significantly longer SB time on weekdays than on weekends, which was not the case in blue‐collar workers. It may be rather challenging for white‐collar workers to limit their SB time to the level recommended by the latest guidelines for better health, especially on weekdays.

With the growing popularity of mobile health (mHealth) devices, including smartphones and wearable devices, information and communications technology has gained high importance in healthcare settings. This study aimed to summarize the current trends in physical activity research wherein mHealth devices are used and provide perspectives for future research. Until recently, questionnaire surveys were primarily used to evaluate physical activity. While questionnaire surveys are effective for subjective evaluation, the use of mHealth devices enables large-scale, real-time, objective evaluation of physical activity. In addition, mHealth devices automatically collect and aggregate data. This allows researchers to perform retrospective analysis of a wide range of indicators of physical activity and health. Particularly, the use of smartphones is highly likely to contribute to large-scale monitoring and health interventions because of their ubiquity. Even though there are fewer users of wearable devices (wrist-worn devices) than those of smartphones, using wearable devices allows for the evaluation of 24-hour movement patterns. The use of wearable devices helps perform further precise analysis that focuses not only on the total amount of physical activity but also on the quality, including measures of intensity, duration, frequency, type, and time. Moreover, some wrist-worn devices measure physiological information such as heart rate and may also provide location information. Combining such data with information from an accelerometer associated with a device may allow for further specific and detailed evaluation of physical activity. The validity of physical activity assessment using major mHealth devices has been confirmed in several studies and is comparable to that of pedometers and accelerometers developed for research purposes. Evaluation of physical activity using mHealth devices involves issues related to the representativeness of the target population and continuity of data, as well as the need for ethical considerations based on privacy policies. While mHealth devices may be used by individuals as a health management tool, it is also expected that the evaluation of physical activity using mHealth devices will be performed in various settings such as epidemiological and clinical studies on physical activity, as well as community services wherein indicators of physical activity are used.

Epidemiology has always been considered a key science of public health. From past to present, scientific evidence arising from high quality epidemiological studies has brought innovation to community practices to control diseases. Thus,epidemiologists have played an important role in providing high quality evidence for policy making and decisions. To control current and future occurrences of disease, it is important to consider how early-career epidemiologists can continue their careers as epidemiologists. Generally, early-career researchers face various barriers to their career progression, such as work-life imbalance, insufficient research funds, or job instability. Identifying these barriers is important when considering beneficial support for career progression. Past findings suggest area-specific barriers among early career researchers in endocrinology, genetics, and psychology. However, little is known about barriers faced by early-career epidemiologists. In August 2017, Japan Young Epidemiology Network (JapanYEN) and the International Epidemiological Association’s (IEA) Early Career Epidemiologists (ECE) Committee collaboratively arranged a workshop regarding career progression among early career epidemiologists at the IEA World Congress of Epidemiology (WCE) in Japan. The current manuscript aims to summarize the outcome of the workshop and to describe perceived barriers for early-career epidemiologists in order to determine future support

We aimed to clarify the status of hand hygiene practices among ordinary citizens during the COVID-19 pandemic in Japan, as well as the frequency of daily hand hygiene as an indicator of education and evaluation. This cross-sectional study was based on an internet survey completed by 2,149 participants (age range: 20-79 years, men: 51.0%, response rate: 89.5%), selected from June 23 to 28, 2020. The participants responded regarding the frequency of implementing hand hygiene at 5 moments (after returning from a public place, after using the toilet, after touching something outside, before eating food, and after blowing the nose, coughing, or sneezing). Additionally, the participants responded to the number of daily hand hygiene events. The cutoff value of the total number of daily hand hygiene events to determine whether hand hygiene was performed at all 5 time points was determined using receiver operating characteristic analysis. The mean number of hand hygiene events was 10.2 times/day. The prevalence of implementing hand hygiene at each moment ranged from 30.2% to 76.4%; only 21.1% of respondents practiced hand hygiene at all times. Both Youden Index and specificity were high when the cut-off value was 11 times/day. Therefore, the criterion of hand hygiene (≥11 times/day) may be useful in education and evaluation.

Objectives To compare physical activity (PA) and sedentary behavior (SB) levels during work time between those who work from home (WFH) and at workplaces (no WFH), and by WFH subgroups. Methods This cross‐sectional internet‐based survey included 1239 workers (mean age [standard deviation], 44.7 [13.7] years; 59.2% men) living in the Tokyo Metropolitan Area. Time spent sitting (SB), standing (light‐intensity PA; LPA), walking, and engaging in heavy labor (moderate‐to‐vigorous PA; MVPA) during work time was measured using the Work‐related Physical Activity Questionnaire. Workers reported weekly WFH percentages (eg, 0% implies no WFH and 100% implies full WFH), and WFH percentages were categorized into no WFH (0% WFH) and WFH (1%‐100% WFH) groups. The WFH group was further subcategorized into 1%‐25%, 26%‐50%, 51%‐75%, and 76%‐100% subgroups. Results Overall, 494 workers (39.9%) worked from home. During working hours, SB time was longer in the WFH group than in the no WFH group (mean minutes [% working‐time SB]: 335.7 vs 224.7 min [74% vs 50%]). Significantly shorter LPA and MVPA times (%) were reported in the WFH group than in the no WFH group (LPA, 59.6 vs 122.9 min [14% vs 29%]; MVPA, 55.3 vs 91.9 min [13% vs 22%], all P

usc Background: Daily step count is the simplest measure of physical activity. However, little is known about how daily step count related to time spent in different intensities of physical activity (PA) and sedentary behavior (SB). Methods: These cross-sectional data were derived from 450 older Japanese adults (56.7% men; mean age, 74.3 years) who were randomly selected from three communities and responded a survey. Daily step count and time spent in moderate-to-vigorous PA (MVPA), light-intensity PA (LPA), and SB were measured using a validated wearable technology (HJA-350IT). Associations of daily step count with time spent in measured behaviors were examined using linear regression models with isometric log-ratio transformations of time-use composition, adjusting for gender, age, and residential area. Results: Participants averaged 5,412 (standard deviation, 2,878) steps/d and accumulated MVPA, LPA, and SB corresponding to 4.0%, 34.8%, and 61.2% of daily waking time, respectively. Daily step count significantly increased with increase in time spent in MVPA relative to other behaviors (ie, LPA and SB) and in the ratio of LPA to SB after allowing for MVPA. After stratification, daily step count was significantly related to the ratio of LPA to SB in those taking

Having gratitude is associated with reduced social isolation and depression, which are risk factors for dementia. However, it is unknown whether gratitude is directly associated with cognitive function. This study aimed to determine associations between gratitude and cognitive function and to elucidate the underlying biological mechanism by testing the mediating role of brain regions among healthy older people.We used cross-sectional data from the 2017 Neuron to Environmental Impact across Generations (NEIGE) study of community-dwelling older adults aged ≥ 65 years (n = 478). Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Levels of gratitude were assessed using the two-items of Gratitude Questionnaire. Volumes of brain regions associated with emotional processing and social interaction were measured by magnetic resonance imaging. Linear regression models and structural equation models were used to examine associations between level of gratitude, brain volume, and cognitive function.The mean gratitude score was 6.3 (SD=0.9) and the mean MMSE score was 27.1 (SD=2.5). Regression analysis showed that higher levels of gratitude were associated with better cognitive function (coefficient=0.25, 95% CI: 0.01, 0.49), adjusting for age, sex, education, marital status, and depressive symptoms. Higher levels of gratitude were associated with larger volumes of right amygdala and left fusiform gyrus. Structural equation model analysis showed that amygdala volumes mediated the association between gratitude and cognitive function.Higher levels of gratitude were positively associated with cognitive function, partially mediated through the amygdala, which is involved in processing emotion and memory.

Since the emergence of the COVID-19 pandemic, the use of face masks by healthy individuals for prevention has been attracting public attention. However, efficacy depends on proper usage. We set out to determine the prevalence of wearing masks to prevent COVID-19 and compliance with appropriate measures for the correct use of face masks among the general public in Japan where wearing medical masks is a &ldquo, cultural&rdquo, normality. This cross-sectional study was based on an internet-based survey completed by 2141 people (50.8% men, aged 20&ndash, 79 years) who were selected among registrants of an Internet research company between 1 April and 6 April 2020. Participants were asked to indicate how often they wore masks for prevention and to what extent they practiced appropriate measures suggested by the World Health Organization. The prevalence of wearing masks was 80.9% and compliance rates with appropriate measures ranged from 38.3% to 83.5%. Only 23.1% complied with all recommendations. Compliance rates were overall low in men and persons with low household incomes. Our results, hence show that many citizens implement inaccurate measures when using face masks. Therefore, providing guidance on correct usage is essential when encouraging the use of face masks to prevent COVID-19.

Background Levels of physical activity change throughout the year. However, little is known to what extent activity levels can vary, based on accelerometer determined sedentary and physically-active time. The aim of this longitudinal study was to examine older adults’ activity changes from a non-snowfall season to a subsequent snowfall season, with consideration of the co-dependence of domains of time use. Methods Participants were 355 older Japanese adults (53.1% women, aged 65–84 years) living in a rural area of heavy snowfall who had valid accelerometer (Active style Pro HJA-750C) data during non-snowfall and snowfall seasons. Activity was classified as sedentary behavior (SB), light-intensity PA (LPA), and moderate-to-vigorous PA (MVPA). Compositional changes from the non-snowfall to the snowfall season were analyzed using Aitchison’s perturbation method. The ratios of each component in the composition, such as [SBsnow/SBnon-snow, LPAsnow/LPAnon-snow, MVPAsnow/MVPAnon-snow] for seasonal changes, were calculated and were then divided by the sum of these ratios. Results In men, the percentages of time spent in each activity during the non-snowfall/snowfall seasons were 53.9/64.6 for SB; 40.8/31.6 for LPA; and 5.3/3.8 for MVPA; these corresponded to mean seasonal compositional changes (∆SB, ∆LPA, ∆MVPA) of 0.445, 0.287, and 0.268 respectively. In women, the percentages of time spent in each activity during the non-snowfall/snowfall seasons were 47.9/55.5 for SB; 47.9/41.0 for LPA; and 4.2/3.5 for MVPA; these corresponded to mean seasonal compositional changes (∆SB, ∆LPA, ∆MVPA) of 0.409, 0.302, and 0.289 respectively. The degree of seasonal change was greatest in men. Conclusions In older adults, activity behaviors were changed unfavorably during snowfall season, particularly so for men. The degree of seasonal change was greatest for SB. Development of strategies to keep rural older adults active during the snowfall season may be needed for maintaining a consistently-active lifestyle for their health.

To examine associations of intensity-specific physical activity and bout-specific sedentary time with frailty status among Japanese community-dwelling older adults, taking into account the interrelationships of these behaviors.Participants were 511 community-dwelling older adults. Physical activity and sedentary time were assessed using a tri-axial accelerometer. Frailty status (frail, pre-frail, or robust) was determined, based on the phenotypic model and used established criteria for Japanese older adults. Associations with frailty status of intensity-specific physical activity and bout-specific sedentary behavior (SB) time were examined using compositional data analysis, adjusted for potential confounders.Participants included 13 (2.6%) who were frail, 234 (45.8%) pre-frail, and 264 (51.6%) who were robust. For the frail and pre-frail, the proportion of time spent in moderate-to-vigorous physical activity (MVPA) was less than for those who were robust. Frail older adults has larger proportion of time spent in prolonged (≥30 min/bouts) sedentary behavior (SB), and less in short-bout (30 min/bout) SB, compared to the robust. No statistically-significant differences in the proportion of time spent in light-intensity physical activity was found across frailty levels.Pre-frail and frail older adults spend proportionally less time in MVPA and more time in prolonged SB, compared with those who were robust. These findings need to be confirmed by evidence from larger and more-diverse study samples and by evidence from prospective studies, in order to better understand whether or not avoiding prolonged periods of sitting could be a potential strategy for preventing frailty among community-dwelling older adults.

Graphical abstract, Highlights • Improvement in personal protective measures since early phase of COVID-19 outbreak. • The prevalence of avoiding touching the eyes, nose, and mouth is still low. • Fewer men and households with low income levels have altered their behavior. • Self-isolation seems difficult for people with low income levels. • There remains room for improvement in personal protective measures by citizens., Objectives To clarify changes in the implementation of personal protective measures among ordinary Japanese citizens from the early phase of the COVID-19 outbreak to the community transmission phase. Methods This longitudinal, internet-based survey included 2,141 people (50.8% men; 20-79 years). The baseline and follow-up surveys were conducted from February 25-27, 2020 and April 1-6, 2020, respectively. Participants were asked how often they implemented the 5 personal protective measures recommended by the World Health Organization (hand hygiene, social distancing, avoiding touching the eyes, nose and mouth, respiratory etiquette, and self-isolation) in the baseline and follow-up surveys. Results The prevalence of 3 of the 5 personal protective measures significantly improved in the community transmission phase compared to the early phase. Social distancing measures showed significant improvement, from 67.4% to 82.2%. However, the prevalence of avoiding touching the eyes, nose and mouth, which had the lowest prevalence in the early phase, showed no significant improvement (approximately 60%). Multivariate logistic regression analysis revealed, men and persons of low-income households made fewer improvements than women and persons of high-income households. Conclusions The prevalence of personal protective measures by ordinary citizens is improving, however there is potential for improvement, especially in regard to avoiding touching eyes, nose and mouth.

The aim of the present study was to investigate the association between falls, including falls on frozen roads, and physical activity among older people living in cold, snowy regions in Japan.Participants were subjects of the Japan Gerontological Evaluation Study 2016 who had agreed to the Hokkaido additional visit survey in winter 2017/18 and lived in cold, snowy regions in Japan. The analysis included 461 participants (mean age 74.7 years; standard deviation 2.8 years; 46.5% male). Sociodemographic characteristics, physical activity (min/day of moderate-to-vigorous intensity physical activity [MVPA] and light intensity physical activity, and walking steps/day) measured by accelerometer, cognitive function, depression, visual impairment, and history of stroke were surveyed. Poisson regression analyses were performed to clarify the association between prevalence of falls and physical activity.Of those who reported a fall with location, 86 (69.9%) fell on frozen roads, 24 (19.5%) fell on unfrozen roads and 13 (10.6%) fell indoors. There were significant positive associations between MVPA (adjusted prevalence ratio [aPR] Tertile [T] 3 vs T1, 1.73; 95% confidence interval [CI], 1.04-2.87) and all falls. When limited to falls on frozen roads, higher MVPA levels and walking steps were associated with falls on frozen roads (MVPA, aPR T3 vs T1, 2.16; 95% CI, 1.19-3.94; walking steps, aPR T3 vs T1, 2.49; 95%CI 1.33-4.68).The risk of falls, especially on frozen roads, increased among active older people living in cold, snowy regions, and environmental factors should be considered when determining prevention strategies.

Brown adipose tissue (BAT) plays a role in adaptive thermogenesis in response to cold environments and dietary intake via sympathetic nervous system (SNS) activation. It is unclear whether physical activity increases BAT density (BAT-d). Two-hundred ninety-eight participants (age: 41.2 ± 12.1 (mean ± standard deviation), height: 163.6 ± 8.3 cm, weight: 60.2 ± 11.0 kg, body mass index (BMI): 22.4 ± 3.0 kg/m2, body fat percentage: 25.4 ± 7.5%) without smoking habits were categorized based on their physical activity levels (a group performing physical activities including walking and moderate physical activity (WM) and a group performing WM + vigorous-intensity physical activities (VWM)). We measured the total hemoglobin concentration ([Total-Hb]) in the supraclavicular region, an index of BAT-d, and anthropometric parameters. [Total-Hb] was significantly higher in VWM than WM for all participant groups presumably owing to SNS activation during vigorous-intensity physical activities, and unrelated to the amount of total physical activity levels. Furthermore, multiple regression analysis revealed that BAT-d was related to visceral fat area and VWM in men and related to body fat percentage in women. We conclude that vigorous-intensity physical activities are associated with high BAT-d in humans, especially in men.

Brown adipose tissue (BAT) mediates adaptive thermogenesis upon food intake and cold exposure, thus potentially contributing to the prevention of lifestyle-related diseases. 18F-fluorodeoxyglucose (FDG)–positron emission tomography (PET) with computed tomography (CT) (18FDG–PET/CT) is a standard method for assessing BAT activity and volume in humans. 18FDG–PET/CT has several limitations, including high device cost and ionizing radiation and acute cold exposure necessary to maximally stimulate BAT activity. In contrast, near-infrared spectroscopy (NIRS) has been used for measuring changes in O2-dependent light absorption in the tissue in a non-invasive manner, without using radiation. Among NIRS, time-resolved NIRS (NIRTRS) can quantify the concentrations of oxygenated and deoxygenated hemoglobin ([oxy-Hb] and [deoxy-Hb], respectively) by emitting ultrashort (100 ps) light pulses and counts photons, which are scattered and absorbed in the tissue. The basis for assessing BAT density (BAT-d) using NIRTRS is that the vascular density in the supraclavicular region, as estimated using Hb concentration, is higher in BAT than in white adipose tissue. In contrast, relatively low-cost continuous wavelength NIRS (NIRCWS) is employed for measuring relative changes in oxygenation in tissues. In this review, we provide evidence for the validity of NIRTRS and NIRCWS in estimating human BAT characteristics. The indicators (IndNIRS) examined were [oxy-Hb]sup, [deoxy-Hb]sup, total hemoglobin [total-Hb]sup, Hb O2 saturation (StO2sup), and reduced scattering coefficient (μs sup′) in the supraclavicular region, as determined by NIRTRS, and relative changes in corresponding parameters, as determined by NIRCWS. The evidence comprises the relationships between the IndNIRS investigated and those determined by 18FDG–PET/CT; the correlation between the IndNIRS and cold-induced thermogenesis; the relationship of the IndNIRS to parameters measured by 18FDG–PET/CT, which responded to seasonal temperature fluctuations; the relationship of the IndNIRS and plasma lipid metabolites; the analogy of the IndNIRS to chronological and anthropometric data; and changes in the IndNIRS following thermogenic food supplementation. The [total-Hb]sup and [oxy-Hb]sup determined by NIRTRS, but not parameters determined by NIRCWS, exhibited significant correlations with cold-induced thermogenesis parameters and plasma androgens in men in winter or analogies to 18FDG–PET. We conclude that NIRTRS can provide useful information for assessing BAT-d in a simple, rapid, non-invasive way, although further validation study is still needed.

Background Sedentary behavior and decreased physical activity are associated with reduced kidney function, yet most evidence is based on self-reported physical activity. This study investigated the association between accelerometer-based physical activity level and kidney function in a general Japanese population. Methods A cross-sectional study was conducted in 440 community-dwelling Japanese participants, aged 35–79 years. Time (min/d) was assessed for the following types of physical activity: sedentary behavior, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA). Kidney function was assessed using estimated glomerular filtration rate (eGFR). A linear regression model was employed to calculate the β coefficient of eGFR for a 60-min/d increase in sedentary behavior and LPA and a 10-min/d increase in MVPA. A logistic regression model was used to calculate the odds ratio for low eGFR (2) for a 60-min/d or 10-min/d increase in each physical activity type. Results MVPA time and eGFR were positively associated in both men and women, after adjusting for age, body mass index, and other clinical characteristics (Men: β, 0.91; P = 0.021; Women: β, 0.70; P = 0.034). In women, sedentary behavior and eGFR were inversely associated after adjusting for the same factors (β, − 1.06; P = 0.048). The odds ratio (95% confidence interval) for low eGFR associated with a 60-min increase in sedentary behavior was 1.65 (1.07–2.55) after adjusting for the same factors in women. Conclusion Longer sedentary behavior and shorter MVPA time were associated with lower kidney function in the Japanese population.

Background An increasing number of studies have demonstrated that light-intensity physical activity (LPA) confers health benefits after adjustment for moderate-to-vigorous physical activity (MVPA). The purpose of this systematic review was to summarize existing epidemiological evidence on associations of objectively measured LPA with health outcomes in adults. Methods This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched on PubMed, Web of Science, CINAL, and Cochrane Library for articles analyzing the association between objectively determined LPA and health outcomes that were published up to January 2017. Data were extracted regarding authors, publication year, country of survey, study setting, number of participants, study design, physical activity (PA) assessment (type of accelerometer and intensity), health outcomes, confounders, and results (summary measures and association). A coding system was used to summarize the results. Results Of the 3254 studies identified, 24 cross-sectional and 6 longitudinal studies were included in this review. Most of the studies targeted the Western population. LPA was inversely associated with all-cause mortality risk and associated favorably with some cardiometabolic risk factors including waist circumference, triglyceride levels, insulin, and presence of metabolic syndrome. Only a small amount of data were available on mental health and cognitive function. Conclusions LPA appears to be beneficially associated with important health outcomes after adjustment for MVPA in the adult population. Although current global PA guidelines recommend only MVPA, promoting LPA may confer additional health benefits. Electronic supplementary material The online version of this article (10.1186/s12966-018-0695-z) contains supplementary material, which is available to authorized users.

Background Men are generally believed to be more physically active than women when evaluated using current physical activity (PA) guidelines, which count only moderate-to-vigorous physical activity (MVPA) in bouts lasting at least 10 min. However, it remains unclear men are truly more physically active provided that all-intensity PA are evaluated. This population based cross-sectional study aimed to examine gender differences in patterns of objectively-assessed PA in older adults. Methods One thousand two hundred ten community-dwelling Japanese older adults who were originally randomly selected from residential registry of three municipalities were asked to respond a questionnaire and wear an accelerometer (HJA-350IT, Omron Healthcare). The prevalence of achieving current PA guidelines, ≥150 min/week MVPA in bouts lasting at least 10 min, was calculated. Gender differences in volume of each-intensity activity (METs-hour) were assessed by analysis of covariance after adjustment for age and wear time. Results Data from 450 (255 men, mean 74 years) participants who had valid accelerometer data were analyzed. Women were less likely to meet the guidelines (men: 31.0, women: 21.5%; p

Background The concept of sekentei (social appearance), defined as sensitivity about one’s reputation, reflects Japanese behavioral principles and involves pressure to conform to social norms, particularly among people living in rural areas. However, data regarding the relationship between sekentei and health behaviors are sparse. In this study, we examined the relationship between sekentei and objectively-measured physical activity among community-dwelling older people in Japan. Methods We used data from the Neuron to Environmental Impact across Generations Study (NEIGE Study), which is a prospective cohort study of randomly-sampled community-dwelling individuals aged 65–84 years living in Tokamachi City, Niigata Prefecture, Japan. The baseline survey was conducted in 2017 and included 527 independent older people. We analyzed the baseline data cross-sectionally. To measure activity behaviors, participants wore a tri-axial accelerometer for seven consecutive days. Physically active individuals were defined based on the World Health Organization recommendation guidelines on physical activity. Sekentei was measured using the 12-item Sekentei Scale (score range: 12–60). Results After excluding 15 people for whom we had three or fewer days of valid accelerometer-assessed activity data, we used data from 512 participants in our analysis (average 73.4 years old; 46.9% men). Physically active individuals made up 22.3% of the sample, and the proportion of physically active men was higher than that of women. A logistic regression analysis showed that higher levels of sekentei were inversely associated with physical activity after adjusting for demographic factors, socioeconomic status, and health conditions (odds ratio [95% confidence interval]: 0.58 [0.36–0.91] for every 10-point increase in the Sekentei Scale score). This association was stronger in women than in men (0.66 [0.34–1.26] for men and 0.51 [0.26–1.00] for women). Conclusions Our findings indicate that an individual’s sense of sekentei may be an important socio-cultural factor affecting their level of physical activity. Culturally appropriate approaches may be beneficial in addressing insufficient physical activity in older adults.

Objective We developed the Work-related Physical Activity Questionnaire (WPAQ) to measure occupational physical activity, including sedentary behavior and sedentary breaks (interruptions of prolonged sedentary behavior), during work. This study aimed to examine the WPAQ's reliability and criterion validity using an accelerometer. Methods To examine criterion validity, 97 full-time factory workers (male: 89.7%) wore a triaxial accelerometer while working and completed the WPAQ. The questionnaire inquired about participants' normal work activities and the proportion of sitting, standing, walking, and heavy labor engaged in during work. In calculating time spent in each behavior, the proportion of each occupational activity was multiplied by the total minutes of work. Duration of uninterrupted sitting time was also measured. For reliability, the same questionnaire was administered twice (median test-retest interval: 9 days) to another convenient sample of 54 participants. Spearman's ρ was used to assess validity and intraclass correlation coefficients (ICCs) and Cohen's kappa with quadratic weighing were used to assess reliability. Results The criterion validity of occupational sitting time measured by the WPAQ was moderate (Spearman's ρ for sedentary behavior: 0.69) based on comparison with accelerometer data. Significant positive correlations were found for standing (ρ = 0.66) and walking (ρ = 0.39) between the WPAQ and accelerometer data, though not for heavy labor. A moderate but significant correlation (ρ = 0.27) was found for sedentary breaks. Test-retest reliability for all items was adequate (ICC = 0.59-0.79 for occupational sedentary behavior and physical activities, and Cohen's kappa with quadratic weighting = 0.84 for sedentary breaks). Conclusions The WPAQ has acceptable properties for measuring workers' activities, including sedentary breaks. Reduced physical activity, increased time spent in sedentary behaviors, and fewer sedentary breaks during working time are all associated with adverse health outcomes. Though some occupational exposure to these activities might be unavoidable, the WPAQ may be a practical tool for assessing them.

We aimed to clarify the patterns of moderate to vigorous physical activity (MVPA) in the Japanese adult population, and the proportion of people meeting the recommendations of the Physical Activity Guidelines (PAG) for Americans, second edition (2nd PAG, &ge, 150 min/week of total MVPA including bouts of any length) and those meeting the previously recommended PAG (2008-PAG, of &ge, 150 min/week of total MVPA lasting 10 min or longer [long-bout MVPA]). A total of 204 adults (aged 18 to 64 years) from two workplaces were asked to wear an accelerometer. MVPA was classified by bout length, and the proportion of long-bout MVPA was clarified. The proportion of participants adhering to the 2008-PAG and the 2nd PAG recommendations was calculated. Valid data was obtained from 184 adults. Long-bout MVPA accounted for 13.4% of total MVPA. Our results showed that 12.5% of individuals performed MVPA as recommended by the 2008-PAG whereas 92.4% performed MVPA as recommended by the 2nd PAG. Our results, hence, showed that long-bout MVPA comprised only a small proportion of total MVPA, and the proportion of individuals who satisfied the criteria stated in the guidelines (&ge, 150 min/week) significantly changed by whether or not bout length of MVPA was taken into account.

Brown adipose tissue (BAT) may potentially be used in strategies for preventing lifestyle-related diseases. We examine evidence that near-infrared time-resolved spectroscopy (NIRTRS) is capable of estimating human BAT density (BAT-d). The parameters examined in this study are total hemoglobin [total-Hb]sup, oxygenated Hb [oxy-Hb]sup, deoxygenated Hb [deoxy-Hb]sup, Hb O2 saturation (StO2sup), and the reduced scattering coefficient in the supraclavicular region (&mu, s&rsquo, sup), where BAT deposits can be located, corresponding parameters in the control deltoid region are obtained as controls. Among the NIRTRS parameters, [total-Hb]sup and [oxy-Hb]sup show region-specific increases in winter, compared to summer. Further, [total-Hb]sup and [oxy-Hb]sup are correlated with cold-induced thermogenesis in the supraclavicular region. We conclude that NIRTRS-determined [total-Hb]sup and [oxy-Hb]sup are useful parameters for evaluating BAT-d in a simple, rapid, non-invasive manner.

AIM We examined the relationships of objectively-measured walkability with accelerometer-measured activity patterns including bout-specific moderate-to-vigorous physical activity (MVPA), light-intensity physical activity (LPA) and sedentary behavior in older Japanese adults. METHODS This cross-sectional study included 450 men and women (mean age 74 years) who were randomly selected from a resident registry of each municipality (Bunkyo, Fuchu and Oyama city). Neighborhood walkability was assessed using geographic information system data and activity patterns by a validated accelerometer (Active style Pro HJA-350IT). MVPA was assessed as overall (all minutes), short-bout (

Most physical activity (PA) guidelines for health promotion recommend moderate to vigorous PA (MVPA) lasting at least 10 minutes (long-bout MVPA). However, recent studies have shown the beneficial effects of short-bout MVPA (intermittent and lasting10 minutes). Therefore, we aimed to clarify the detailed patterns of MVPA of community-dwelling older adults using accelerometers.This is a cross-sectional descriptive study. Community-dwelling older Japanese adults (total: 1,210; 70-80 years of age) randomly selected from residential registries of 3 municipalities (Bunkyo, Fuchu, and Oyama) were asked to wear an accelerometer (HJA-350 IT; Omron Healthcare, Japan). MVPA was classified by bout length (1-4, 5-9, 10-19, 20-29, and30 minutes). The mean frequency and duration of MVPA by each bout length and the proportion of long-bout MVPA were described.Valid data were obtained from 450 participants (men: 56.7%; mean age: 74 years). The mean±standard deviation of the frequency and duration of MVPA bouts were 21.8±14.6 times/day and 2.1±0.9 min, respectively. The total duration of MVPA was 46.5±33.0 min/day. Long-bout MVPA accounted for 26.9%±23.5% of daily MVPA, whereas MVPA of 1-4 minutes accounted for 43.4%.Older adults performed about 45 minutes of MVPA a day, but most of this was short-bout MVPA, which is overlooked by current WHO PA guidelines. In particular, short-bout MVPA was frequent among older women and those living in rural areas.

As people age, they spend more time in and around their domestic environments, within which opportunities for health-enhancing physical activity (PA) may be limited. We examined the associations of frequency of excursions from home with accelerometer-determined PA and the total and prolonged sedentary behavior (SB, sitting for ≥30 min) among community-dwelling older adults.Overall, 434 older adults (men, 57.1 %; age, 70-79 years) wore an accelerometer (HJA-350IT, Omron Healthcare) for 7 days. Time spent in SB, light-intensity PA (LPA), moderate-to-vigorous PA (MVPA), and prolonged SB bout (≥30 min) were calculated. Frequencies of excursions from home were categorized as 0-3, 4-5, and 6-7 days/week. Associations of excursions with PA and SB were tested by analysis of covariance adjusted for sociodemographic characteristics.Frequencies were 14.3 %, 31.1 %, and 54.6 % for excursions 0-3, 4-5, and 6-7 days/week, respectively. For men, less frequent excursions from home were significantly associated with less MVPA and more total and prolonged SB times (estimated means [minutes/day]: MVPA, 32, 42, and 48; total SB, 589, 549, and 539; prolonged SB, 344, 288, and 265; respectively; p0.05). LPA was not statistically significant (p = 0.09). For women, less frequent excursions were significantly associated with all PA outcomes (SB: 536, 497, and 467; prolonged SB: 260, 213, and 204; LPA: 328, 363, and 379; MVPA: 36, 39, and 54, respectively).Among community-dwelling Japanese older adults, more frequent excursions from home were associated with more PA, less SB, and more-favorable SB patterns, suggesting a potential strategy for preventive-health initiatives.

Although the pedestrian-friendly qualities of streetscapes promote walking, quantitative understanding of streetscape functionality remains insufficient. This study proposed a novel automated method to assess streetscape walkability (SW) using semantic segmentation and statistical modeling on Google Street View images. Using compositions of segmented streetscape elements, such as buildings and street trees, a regression-style model was built to predict SW, scored using a human-based auditing method. Older female active leisure walkers living in Bunkyo Ward, Tokyo, are associated with SW scores estimated by the model (OR = 3.783; 95% CI = 1.459 to 10.409), but male walkers are not.

Objectives: This study investigated the longitudinal association between changes in older adults&rsquo, physical activity and neighborhood walkability measured by geographic information systems (GISs, (ArcGIS, ESRI Inc., Redlands, CA, USA)). Methods: A mail survey was conducted for Japanese older adults who were randomly selected from three different settlement types. Data on walking, total moderate to vigorous physical activity (MVPA), and sociodemographic characteristics were collected at baseline (in 2010) and follow-up (in 2015). Multiple linear regression analyses were employed to assess the association between MVPA change and neighborhood walkability, adjusted for potential confounders. Effect sizes for independent variables on MVPA change were estimated. Results: Data from 731 community-dwelling older adults (43.7% women) were analyzed. During the follow-up, older adults&rsquo, MVPA was reduced by 94.4 min/week (&minus, 14.2%) on average (675.5 and 579.9 min/week in 2010 and 2015, respectively). Overall, older adults living in highly walkable areas showed a smaller reduction than those in low walkable areas (beta: 99.7 min/week, 95% confidence interval: 28.5&ndash, 171.0). Similar associations were observed among those in the urban and suburban area, but not in the rural area. Walkability had larger effect sizes for explaining MVPA change than demographic characteristics. In addition, the findings for walking were similar to MVPA. Conclusion: Neighborhood walkability mitigated the 5-year reduction of walking and total MVPA among older adults, especially in urban areas.

Background Brown adipose tissue (BAT) is sympathetically activated and induces thermogenesis during cold exposure, thereby influencing energy expenditure and body fat levels. The very low frequency (VLF) components of pulse rate variability could be a form of thermogenic sympathetic nervous activity, but no clear relationship has yet been reported between VLF activity and BAT density. We therefore aimed to evaluate the association between them. Methods We enrolled 20 adults in winter and 20 matched adults in summer. We assessed BAT densities based on total hemoglobin concentrations ([total-Hb]) measured with near-infrared time-resolved spectroscopy. We calculated VLF activity from pulse rate variability measurements. Results BAT density ([total-Hb]; winter 70.5 ± 17.0 μM, summer 57.8 ± 18.3 μM) and VLF activity (winter 6.7 ± 0.8, summer 6.1 ± 0.9) were significantly higher in winter than in summer (P

F18-fluorodeoxyglucose (FDG)–positron emission tomography (PET) along with computed tomography (CT) is a standard method for assessing brown adipose tissue (BAT) activity. We tested the usefulness of near-infrared time-resolved spectroscopy (NIRTRS) as a simple and noninvasive method for evaluating BAT density (BAT-d) by examining the effects of some factors known to influence BAT activity. The total hemoglobin concentration as a parameter of BAT-d was evaluated using NIRTRS in the supraclavicular region in 413 Japanese individuals. The associations were analyzed between BAT-d and sex, age, the percentages of body fat (%BF), visceral fat (VF), and the seasonal ambient temperature (AmT) fluctuations. Age was associated with decreased BAT-d (P

Introduction The most effective type of social participation against psychological distress in older adults is not well documented. The aim of this study was to examine whether different types of social participation are associated with changes in psychological distress level in older men and women in Japan. Methods Two thousand seven hundred community-dwelling older adults (aged 65–74 years, 50% women) were randomly selected from the resident registry of three cities. Of these, participants who reported social participation and psychological distress level in the baseline survey in 2010 were followed up. Psychological distress was evaluated based on K6 scales at baseline and follow-up (in 2015). Social participation level was examined using question items from the National Health and Nutrition Survey in Japan. Exploratory factor analysis was used to derive the underlying factor structure. Multiple linear regression analysis was used to examine the association between social participation and changes in psychological distress level after adjusting for covariates stratified by both gender and age group or living arrangement. Results Data from 825 community-dwelling older adults (45.3% women) were analyzed. Social participation was categorized into two types using factor analysis: community involvement (volunteer activities, community events, clubs for the elderly) and individual relationship (friendship, communication with family and friends, hobbies). During the 5-year follow-up, 29.5% of participants reported a deterioration in psychological distress. Higher community involvement was independently associated with lower risk of psychological distress for older women (β = 0.099, p = 0.047), whereas there were no associations with individual relationship for either gender. Furthermore, in older women living with others, higher community involvement was also associated with lower risk of psychological distress (β = 0.110, p = 0.048). Conclusion Community involvement provides older women with mental health benefits regardless of individual relationship level. Promoting community involvement may be an effective strategy for healthy mental aging.

Social participation provides health benefits for older adults. However, there is the need to identify whether higher social participation is associated with older adults being more physically active and less sedentary (sitting time). We examined the associations of social participation with physical activity, and sedentary time, in a population-based sample of older Japanese adults.A population-based, cross-sectional mail survey carried out in 2010 was used to collect data on social participation, physical activity, sedentary time and sociodemographic characteristics. Data were examined from 1146 community-dwelling, unemployed older adults (mean age 70.1 years, 43% men). Multivariate logistic regression analyses were used to calculate odds ratios (OR) for associations of social participation with physical activity and total sedentary time; and, for associations with passive and mentally-active sedentary (sitting) time.For both men and women, those with higher social participation were more physically active (OR 2.10, 95% CI 1.44-3.06 among men; OR 1.93, 95% CI 1.39-2.68 among women). Total sedentary time had significant associations among men (OR 0.62, 95% CI 0.42-0.90), but not among women (OR 0.80, 95% CI 0.58-1.11). Social participation was associated with less passive sedentary time (OR 0.55, 95% CI 0.38-0.81 for men; OR 0.72, 95% CI 0.51-0.99 for women).Promoting social participation among older adults could contribute to increasing physical activity and reducing sedentary time, with potential benefits for chronic disease. Further research is required to elucidate the deleterious and beneficial roles of passive and mentally-active sedentary time for older adults. Geriatr Gerontol Int 2017; 17: 1921-1927.

Car use has been identified as sedentary behavior, although it may enhance mobility, particularly in the older population. This cross-sectional study aimed to compare the time spent in objectively determined sedentary behavior (SB) and physical activity (PA) between older drivers and non-drivers. Four hundred and fifty Japanese older adults (74.3 ± 2.9 years) who had valid accelerometer data were included. They were asked to respond to a questionnaire and wear an accelerometer (HJA-350IT, Omron Healthcare) on their waist for 7 consecutive days in 2015. To compare activity time between drivers and non-drivers, we calculated estimated means using analysis of covariance, adjusting for sociodemographic, physical, and psychological factors and accelerometer wear time. Compared to non-drivers, drivers engaged in more light-intensity PA (LPA) (drivers: 325.0 vs. non-drivers: 289.0 min/day) and moderate-to-vigorous PA (drivers: 37.5 vs. non-drivers: 30.0 min/day) and less SB (drivers: 493.4 vs. non-drivers: 535.9 min/day) (all p < 0.05). After stratification by age, sex, and residential area, larger effect of driving on PA time was found in older-older adults, in men, and in rural residents. Older drivers were found to be more physically active than non-drivers, suggesting more access to outdoor activities or expanding social network.