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Abstract Background Few studies have shown that relatively younger children and adolescents (those born later in the same school year) were less likely to engage in physical activity in a phenomenon termed the relative age effect. Although these studies mainly targeted elementary and middle school students, no study has reported on the relative age effect on physical activity in ordinary high school students. Moreover, the relative age effect on sedentary behavior might show an opposite association with physical activity. Therefore, we aimed to clarify the relative age effects on physical activity and sedentary behavior across different school stages in Japanese children and adolescents. Methods A cross-sectional questionnaire survey was conducted with 21,491 children and adolescents (elementary, middle, and high school students aged 10–18 years) in various Japanese regions from January 2018 to July 2019. Overall, 18,281 children and adolescents (10,299 boys and 7,982 girls) were finally included in our analysis. Data on the birth month, frequency and duration of their physical activity (vigorous, moderate, and moderate-to-vigorous intensity), and sedentary behavior (weekday and weekend total sedentary time, television viewing, playing video games, and Internet use) were obtained. We utilized two-part model regression analyses. Statistically significant association with birth month indicated that a relative age effect was observed. Results The relatively younger individuals were less likely to engage in physical activity (especially vigorous physical activity (VPA)); this association was observed in middle and high school students. Conversely, the relatively younger boys spent more time during weekends with sedentary behaviors and Internet use. Based on school stage, the relative age effect on VPA time was observed in middle school boys (average margin effect (AME) = -0.74, p

Background: No municipal-level study has elucidated the social determinants associated with multimorbidity prevalence (MP). Objective: This article aimed to determine the differences in MP among municipalities and investigate factors associated with such differences through an ecological study of data obtained from a nationwide survey. This article focused on social participation and household income, which are associated with single chronic diseases, such as hypertension. Methods: Study design was a cross sectional study, which used the data from the Japan Gerontological Evaluation Study, a population-based gerontological study among functionally independent older adults aged ≥65 years in Japan. Overall, 152 212 participants from 2016 to 2017 across 91 municipalities were included in the final analysis. Multiple regression analysis was performed with MP as objective variable; social participation or household income were explanatory variables, and education, population density, and health check-ups were adjustment variables. Results: Intermunicipal differences in MP were 28.4% to 43.1% and 23.2% to 38.8% among men and women, respectively. Significant negative correlation was observed between MP and proportion of social participation (non-standardized coefficient [ B ] = −.18 for men and women). A significant positive correlation was noted between MP and equivalent household income of ≤2 million yen in women ( B = .21). Conclusion: Considerable differences in MP existed among municipalities. Areas with high proportion of social participation showed significantly lower MP. Considering the difficulty in managing multimorbidity within the primary care field and limited evidence on effective interventions, community-level interventions encouraging social participation among older individuals might reduce MP. Primary care physicians should consider a community health approach for multimorbidity.

Abstract Background Community-level group sports participation is a structural aspect of social capital that can potentially impact individual health in a contextual manner. This study aimed to investigate contextual relationship between the community-level prevalence of group sports participation and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality in older adults. Methods In this 7-year longitudinal cohort study, data from the Japan Gerontological Evaluation Study, a nationwide survey encompassing 43,088 functionally independent older adults residing in 311 communities, were used. Cause of death data were derived from the Japanese governmental agency, The Ministry of Health, Labour and Welfare, for secondary use. “Participation” was defined as engaging in group sports for one or more days per month. To analyze the data, a two-level survival analysis was employed, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. Results Among the participants, 5,711 (13.3%) deaths were identified, with 1,311 related to CVD and 2,349 to cancer. The average group sports participation rate was 28.3% (range, 10.0–52.7%). After adjusting for individual-level group sports participation and potential confounders, a higher community-level group sports participation rate was found to be significantly associated with a lower risk of both all-cause mortality (HR: 0.89, 95% CI: 0.83–0.95) and cancer mortality (HR: 0.89, 95% CI: 0.81–0.98) for every 10% point increase in the participation rate. For CVD mortality, the association became less significant in the model adjusted for all covariates (HR: 0.94, 95% CI: 0.82–1.09). Conclusions Our findings support the existence of a preventive relationship between community-level group sports participation and the occurrence of all-cause and cancer mortality among older individuals. Promoting group sports within communities holds promise as an effective population-based strategy for extending life expectancy, regardless of individual participation in these groups.

Abstract Background Older adults who engage in group sports and exercises achieve greater health benefits than those who exercise by themselves. The benefits of group participation may vary depending on the type of sports/exercise they engage in. The present study aimed to identify the association between specific sports and exercise types performed in groups and evaluate the longitudinal changes in multidimensional frailty scores among community-dwelling older adults in Japan. Methods We used 3-year follow-up data from the Japan Gerontological Evaluation Study and analyzed 33,746 men and 36,799 women aged ≥ 65 years. To elucidate the relationship between participation in 20 types of group sports/exercises in 2016 (baseline) and the change in frailty score (using the Kihon Checklist, KCL) from 2016 to 2019, we performed linear regression analyses through multivariate adjustments for age group, self-rated health, marital status, living alone, occupational status, years of education, alcohol drinking status, smoking status, equivalent income, and disease status using an inverse probability weighting method. P

Objectives: This study aimed to investigate the association between whole-body (WB), arm, and leg extracellular-to-intracellular water resistance (Recw/Ricw) ratios and various physical functions of each segment and muscle mass using segmental multifrequency bioelectrical impedance analysis. Methods: In total, 988 community-dwelling older adults were included in the analysis. Physical function was assessed using hand grip, 5-repetition sit-to-stand, 5-m habitual walk, Timed Up and Go, and single-leg balance with eyes open tests. Each segmental Recw/Ricw ratio and muscle mass were assessed at 5 and 250 kHz resistances using a segmental multifrequency bioelectrical impedance analysis device. Pearson's correlation between the segmental Recw/Ricw ratio and muscle mass and physical function was calculated, and the difference in correlation coefficients was tested using Bonferroni correction. Multiple linear regression analysis was conducted using physical function as the dependent variable and the segmental Recw/Ricw ratio as the independent variable, adjusting for sex, age, body mass index, and segmental muscle mass. Results: WB and leg Recw/Ricw ratios were significantly positively correlated with good hand grip performance, gait speed, mobility, balance, and standing power (p

Abstract Background Relative age effect is defined as a phenomenon where children born early generally perform better than children born later in the same cohort. Physical activity is an important factor that might be influenced by the relative age effect. Socioeconomic factors (e.g., parent’s income, education level) are also associated with the adolescent’s physical activity. However, no existing study has examined whether socioeconomic factors moderate the relative age effect on the adolescent’s physical activity. This study aims to clarify whether and how birth month and socioeconomic factors relate to organized sports and physical activity among adolescents in Japan. Methods We conducted a questionnaire survey targeting 21,491 adolescents who live in a widespread neighborhood. We included 8102 adolescents (4087 males and 4015 females: mean age 13.1 ± 1.4) in the analysis. Based on the participants’ birth months, we divided them into four groups (April to June, July to September, October to December, January to March). We asked participants to report their organized sports participation. Using the International Physical Activity Questionnaire for Japanese Early Adolescents, we identified their moderate to vigorous physical activity (MVPA). Neighborhood-level socioeconomic factors (areal deprivation, average annual income, education level) were analyzed based on national surveys, such as the population census. We performed multilevel logistic and linear regression analysis for organized sports participation and MVPA, respectively. Moreover, a simple slope analysis was implemented if the interaction between birth month and socioeconomic factor was significant in the multilevel linear regression analysis. Results Among males, relatively younger adolescents (adolescents who were born later in the same grade) were less likely to participate in organized sports activites (OR=0.90, 95% CI 0.82–0.97, p

Acceleration parameters in sit-to-stand (STS) movements are useful for measuring lower-limb function in older adults. The purpose of this study was to examine the relationship between acceleration in STS movements and physical function and the test-retest reliability of acceleration parameters in older adults. We performed cross-sectional analyses on 244 older adults including 107 men (mean age: 77.4 ± 4.7) and 137 women (mean age: 75.6 ± 5.3). Four acceleration parameters were measured in STS movements: maximum acceleration (MA), maximum velocity (MV), maximum power (MP), and stand-up time (ST). Good intraclass correlation coefficients (ICC > 0.70) were observed for all parameters. For the acceleration parameters, MA, MV, and MP were relatively strongly associated with the 5-time STS test (men: r = −0.36~−0.47; women: r = −0.37~−0.45) and the timed up and go test (men: r = −0.39~0.47, women: r = −0.43~−0.51): MP was also strongly associated with grip strength (men: r = 0.48, women: r = 0.43). All acceleration parameters were poorer in participants reporting mobility limitations than in those reporting no mobility limitations. These findings support the usefulness of sensor-based STS measurement. The system is expected to be useful in various settings where care prevention is addressed.

Abstract This study aimed to identify factors associated with engaging in sports and exercise volunteering among older adults. We used cross-sectional data from the Japan Gerontological Evaluation Study (JAGES), a nationwide mail survey of 20,877 older adults from 60 municipalities. Multilevel mixed-effects logistic regression analysis was used to investigate the correlation between engaging in sports and exercise volunteering and 39 variables classified into five factors: (1) demographic and biological, (2) behavioral, (3) psychological, cognitive, and emotional, (4) social and cultural, and (5) environmental factors. Among the analyzed samples, 1580 (7.6%) participants volunteered a few times/year or more often. Factors that showed positive association with the volunteering were older age, a current drinking habit, excellent self-rated health, high proportion of sports group participants in a living area, low municipal population density, and rich social and cultural features (i.e., social cohesion, support, network, and participation). Meanwhile, those that had a negative association were women, low level of education, deteriorated instrumental activities of daily living, having a past or current smoking habit, poor self-rated health, and depressive symptoms. We clarified the characteristics of the population that is more likely to participate in sports and exercise volunteering as well as those of the population that is less likely to participate and requires support.

Abstract Background Among all physical activities, walking is one of the easiest and most economical activities for older adults’ mental and physical health. Although promoting social participation may extend the walking time of older adults, the longitudinal relationship is not well understood. Thus, this study elucidates the relationship between nine types of social participation and change in walking time during a 3-year follow-up of older adults. Methods We conducted a 3-year community-based longitudinal study of independent older adults in Japan. From the 2016 and 2019 surveys, we extracted 57,042 individuals. We performed multiple regression analyses, estimating associations between change in walking time after three years and nine types of social participation in 2016: volunteer, sports, hobby, senior, neighborhood, learning, health, skills, and paid work. We conducted subgroup analysis stratified by walking time in 2016 (i.e.,

Abstract Background As the understanding of the association between community-level education and dementia is insufficient, this study examined the contextual association of community-level prevalence of low educational attainment on the risk of dementia incidence. With this study, we further explored the potential differences in the aforementioned associations for urban and non-urban areas. Methods We analyzed 6 years of prospective cohort data from the Japan Gerontological Evaluation Study, beginning with the baseline data collected between 2010 and 2012, for 51,186 physically and cognitively independent individuals aged ≥65 years (23,785 men and 27,401 women) from 346 communities in 16 municipalities across 7 prefectures. We assessed dementia incidence using available data from the long-term care insurance system in Japan. We dichotomized education years as ≤9 and ≥ 10 years and aggregated individual-level educational attainment as a community-level independent variable. Model 1 covariates were age and sex. Income, residential years, disease, alcohol, smoking, social isolation, and population density were added in Model 2. We conducted multiple imputation to address the missing data. We performed a two-level (community and individual) survival analysis to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Results The results indicate that the cumulative incidence of dementia during the follow-up period was 10.6%. The mean proportion with educational attainment of ≤9 years was 40.8% (range: 5.1–87.3%). Low community-level educational attainment was significantly associated with higher dementia incidence (HR: 1.04; 95% CI: 1.01–1.07), estimated by 10 percentage points of low educational attainment after adjusting for individual-level educational years and covariates. While the association was significant in non-urban areas (HR: 1.07; 1.02–1.13), there was no association in urban areas (HR: 1.03; 0.99–1.06). Conclusions Older people living in communities with low educational attainment among their age demographic develop dementia more often compared with those living in areas with high educational attainment after adjusting for individual-level educational attainment and covariates; the association was pronounced in non-urban areas. Securing education for adolescents as a life course and population approach could thus be crucial in preventing dementia later in life among older people living in non-urban areas.

Background: Existing evidence suggest that those who are socially isolated are at risk for taking up or continuing smoking. This study investigated country-based differences in social isolation and smoking status. Methods: We performed a repeated cross-sectional study using two waves of data from two ongoing aging studies: the English Longitudinal Study of Ageing and the Japan Gerontological Evaluation Study. Participants from both studies aged ≥65 years were included. We applied a multilevel Poisson regression model to examine the association between social isolation and smoking status and adjusted for individual sociodemographic characteristics. We used the social isolation index which comprises the following domains: marital status; frequency of contact with friends, family, and children; and participation in social activities. Interaction terms between each country and social isolation were also entered into the mode. Results: After exclusion of never smokers, we analyzed 75,905 participants (7,092 for ELSA and 68,813 for JAGES, respectively). Taking ex-smokers as the reference, social isolation was significantly associated with current smoking; the prevalence ratios (PRs) were 1.06 (95% credible interval [CrI], 1.05–1.08) for men and 1.08 (95% CrI, 1.04–1.11) for women. Taking Japan as a reference, the interaction term between country and social isolation was significant for both sexes, with increased PRs of 1.32 (95% CrI, 1.14–1.50) for men and 1.30 (95% CrI, 1.11–1.49) for women in England. Conclusions: Older people who were less socially isolated were more likely to quit smoking in England than in Japan, possibly explained by the strict tobacco control policies in England.

Background: Active engagement in intellectually enriching activities reportedly lowers the risk of cognitive decline; however, few studies have examined this association, including engagement in traditional cultural activities. This study aimed to elucidate the types of cultural engagement associated with lower risk of cognitive impairment. Methods: We examined the association between cultural engagement and cognitive impairment using Cox proportional hazards models in a cohort of 44,985 participants (20,772 males and 24,213 females) aged 65 years or older of the Japan Gerontological Evaluation Study from 2010 to 2016. Intellectual activities (eg, reading books, magazines, and/or newspapers), creative activities (eg, crafts and painting), and traditional cultural activities (eg, poetry composition [haiku], calligraphy, and tea ceremony/flower arrangement) were included among cultural engagement activities. Results: Over a follow-up period of 6 years, incident cognitive disability was observed in 4,198 respondents (9.3%). After adjusting for potential confounders, such as depression and social support, intellectual activities were protectively associated with the risk of cognitive impairment (hazard ratio [HR] for those who read and stated that reading was their hobby, 0.75; 95% confidence interval [CI] 0.66–0.85 and HR for those who read but did not consider reading a hobby, 0.72; 95% CI, 0.65–0.80). Engagement in creative activities was also significantly correlated with lower risk of cognitive impairment (crafts: HR 0.71; 95% CI, 0.62–0.81 and painting: HR 0.80; 95% CI, 0.66–0.96). The association between traditional cultural activities and the risk of cognitive impairment was not statistically significant. Conclusions: Engagement in intellectual and creative activities may be associated with reduced risk of dementia.

Abstract Background The causal effect of physical activity on reducing dementia risk has been questioned due to the possibility of reverse causation. This study examined the potential causal effects of physical activity on reducing dementia risk using residency in a snowy area as an instrumental variable (IV) representing the physical activity of older adults. Methods We used cohort data from the Japan Gerontological Evaluation Study, a longitudinal cohort enrolling people aged 65 or older who were physically and cognitively independent in 2013; study participants were followed for an average of 5.7 years. Participants in the present study included 73,260 individuals living in 19 municipalities in Japan. Physical activity was measured by self-report questionnaires and the incidence of dementia was ascertained by linking participants to the public registries of long-term care insurance. IV estimation was obtained from a piecewise Cox proportional hazard model using a two-stage regression procedure. Results During the study period, we ascertained 8714 cases (11.9%) of dementia onset. In the IV analysis, we found that the frequency of physical activity per week was negatively associated with dementia risk, though the association weakened over time (Year 1: hazard ratio = 0.53, 95% confidence interval: 0.39–0.74; Year 4: 0.69, 0.53–0.90; Year 6: 0.85, 0.66–1.10). Conclusions Our IV analysis indicated a potential causal effect of physical activity on reducing dementia risk that persisted for at least 4 years of follow-up. Thus, we conclude that physical activity should be recommended for older adults to reduce dementia risk.

Objectives: Elder abuse is a public health issue that is thought to have increased during the COVID-19 pandemic due to lockdowns and behavioral restrictions. This study examines the association between elder abuse and refrainment from daily activities during the pandemic. Methods: We used data from a self-administered mail survey conducted by the Japan Gerontological Evaluation Study (JAGES) from November 2020 to February 2021 in 11 municipalities. Our participants included 18,263 older adults (age ≥65 years) who were independent in their daily lives. Logistic regression analysis was conducted to evaluate the association between elder abuse and refrainment from 10 daily activities, and the total number of refrained behaviors. Results: Experiences of abuse were reported by 288 participants (1.6%). The risk of elder abuse was 1.37 times (95% confidence interval, 1.04–1.81) higher among those who refrained from shopping for food and daily necessities and 1.60 times (1.20–2.13) higher among those who refrained from interaction with neighbors, than those who did not. Also, a dose-response relationship was observed where the risk of abuse increased with the number of restrictions. Conclusion: The risk of elder abuse increased as the number of refrained behaviors increased which suggests that refrainment from multiple behaviors may significantly increase the risk of elder abuse, compared with refrainment from a single behavior. To avoid increasing the risk of abuse in likely future pandemics, it is necessary to maintain social connections without face-to-face contact, or with adequate infection control measures.

Abstract The current study investigated the relationship between the frequency of watching sports and depressive symptoms among older adults. This study used cross-sectional data from the Japan Gerontological Evaluation Study, a nationwide mail survey of 21,317 older adults. Depressive symptoms were defined as a Geriatric Depression Scale score of ≥ 5. Participants were queried regarding the average frequency at which they watched sports on-site and via TV/Internet over the past year. Among the 21,317 participants, 4559 (21.4%) had depressive symptoms, while 4808 (22.6%) and 16,576 (77.8%) watched sports on-site and via TV/Internet at least once a year, respectively. Older adults who watched sports on-site a few times/year (prevalence ratio, 0.70; 95% confidence interval, 0.65–0.74) or 1–3 times/month (0.66, 0.53–0.82) were less likely to have depressive symptoms compared to non-spectators after adjusting for frequency of playing sports, exercise activities, and other potential confounders. Meanwhile, a dose–response relationship was confirmed for watching via TV/Internet (prevalence ratio of 0.86, 0.79, and 0.71 for a few times/year, 1–3 times/month, and ≥ 1 time/week, respectively). This study suggested that watching sports on-site or via TV/Internet, regardless of whether they regularly engage in sports, may reduce the risk of depressive symptoms among older adults.

Objective: This study examined the relationship between neighborhood food and physical activity environment, and obesity among elementary and junior high school students in Japan. Methods: The participants were fifth- to ninth-grade children (n=7277), who were attending municipal schools in Japan. Percent overweight (POW) was calculated using their age, gender, height, and weight, which were collected through a questionnaire. A POW of < 20% was considered non-obese, while ≥ 20% was considered obese. Furthermore, using a geographic information system, we investigated the density of convenience stores, fast-food stores, casual restaurants, supermarkets and department stores, parks, sports facilities, stations, and intersections in the school district. Additionally, from the census, we obtained information regarding the population density of the municipality where the participants’ schools were located. Multiple logistic regression analysis was used to examine the relationship between obesity and food environment (the food environment model), between obesity and physical activity environment (the physical activity environment model), and among obesity, food, and physical activity environment (the food and physical activity environment model). Results: In the food environment model and the food and physical activity environment model, the density of convenience stores showed a significant positive association. In the physical activity environment model, the density of stations showed a significant negative association. Conclusion: This study’s findings can contribute to the development of appropriate community interventions for improving children’s health in Japan and similar areas.

Background: While bathing styles vary among countries, most Japanese people prefer tub bathing to showers and saunas. However, few studies have examined the relationship between tub bathing and health outcomes. Accordingly, in this prospective cohort study, we investigated the association between tub bathing frequency and the onset of functional disability among older people in Japan. Methods: We used data from the Japan Gerontological Evaluation Study (JAGES). The baseline survey was conducted from August 2010 through January 2012 and enrolled 13,786 community-dwelling older people (6,482 men and 7,304 women) independent in activities of daily living. During a 3-year observation period, the onset of functional disability, identified by new certification for need of Long-Term Care Insurance, was recorded. Tub bathing frequencies in summer and winter at baseline were divided into three groups: low frequency (0–2 times/week), moderate frequency (3–6 times/week), and high frequency (≥7 times/week). We estimated the risks of functional disability in each group using a multivariate Cox proportional hazards model. Results: Functional disability was observed in a total of 1,203 cases (8.7%). Compared with the low-frequency group and after adjustment for 14 potential confounders, the hazard ratios of the moderate- and high-frequency groups were 0.91 (95% confidence interval [CI], 0.75–1.10) and 0.72 (95% CI, 0.60–0.85) for summer and 0.90 (95% CI, 0.76–1.07) and 0.71 (95% CI, 0.60–0.84) for winter. Conclusion: High tub bathing frequency is associated with lower onset of functional disability. Therefore, tub bathing might be beneficial for older people’s health.

Objective Recently, there has been an increase in the number of people with dementia. However, no study has examined the association between community-level social support and the onset of incident dementia using multilevel survival analysis.Design A prospective cohort study.Participants and setting We analysed data pertaining to 15 313 (7381 men and 7932 women) community-dwelling adults aged 65 years or older who had not accessed long-term care insurance and were living in Aichi Prefecture (seven municipalities) in Japan.Primary and secondary outcome measures The association between community-level social support and onset of incident dementia was examined using the Japan Gerontological Evaluation Study, a prospective cohort study introduced in Japan in 2003. Incident dementia was assessed using Long-term Care Insurance records spanning 3436 days from the baseline survey.Results During the 10-year follow-up, the onset of incident dementia occurred in 1776 adults. Among older people, a 1% increase in community-level social support (in the form of receiving emotional support) was associated with an approximately 4% reduction in the risk of developing dementia, regardless of socio-demographic variables and health conditions (HR=0.96; 95% CI=0.94 to 0.99).Conclusions Receiving community-level social support in the form of emotional support is associated with a lower risk of developing incident dementia.

Objective Social isolation is a risk factor for depression in older age. However, little is known regarding whether its impact varies depending on country-specific cultural contexts regarding social relationships. The present study examined the association of social isolation with depression onset among older adults in England, which has taken advanced measures against social isolation, and Japan, a super-aged society with a rapidly increasing number of socially isolated people.Design Prospective longitudinal study.Setting We used data from two ongoing studies: the English Longitudinal Study of Ageing (ELSA) and the Japan Gerontological Evaluation Study (JAGES).Participants Older adults aged ≥65 years without depression at baseline were followed up regarding depression onset for 2 years (2010/2011–2012/2013) for the ELSA and 2.5 years (2010/2011–2013) for the JAGES.Primary outcome measure Depression was assessed with eight items from the Centre for Epidemiologic Studies Depression Scale for the ELSA and Geriatric Depression Scale for the JAGES. Multivariable logistic regression analysis was performed to evaluate social isolation using multiple parameters (marital status; interaction with children, relatives and friends; and social participation).Results The data of 3331 respondents from the ELSA and 33 127 from the JAGES were analysed. Multivariable logistic regression analysis demonstrated that social isolation was significantly associated with depression onset in both countries. In the ELSA, poor interaction with children was marginally associated with depression onset, while in the JAGES, poor interaction with children and no social participation significantly affected depression onset.Conclusions Despite variations in cultural background, social isolation was associated with depression onset in both England and Japan. Addressing social isolation to safeguard older adults’ mental health must be globally prioritised.

Sports group participation may have greater effects on health outcomes than exercising alone. Unhealthy lifestyles were reported to be specifically associated with lower socioeconomic positions (SEPs), and child poverty and the bipolarization of sports participation are currently major policy concerns in children. However, it remains unclear whether childhood SEP has any long-latency effect on sports group participation among older Japanese. Data were obtained from the Japan Gerontological Evaluation Study 2010 project, which used self-report questionnaires to survey individuals aged ≥65 years without disability from 27 municipalities (n = 23,320). According to their answers, respondents were assigned to one of three SEP groups: high, middle, or low. Poisson regression with robust variance and multiple imputations was used to examine the association between childhood SEP and sports group participation. After adjusting for health-related factors, low childhood SEP was negatively associated with sports group participation in men (prevalence ratio [PR] = 0.82, 95% confidence interval [CI] = 0.74–0.91) and women (PR = 0.88, 95% CI = 0.80–0.97). The PR was greatly attenuated after adjusting for educational attainment in both men (PR = 0.92, 95% CI = 0.83–1.02) and women (PR = 0.98, 95% CI = 0.89–1.08), and the significant association disappeared. Low childhood SEP is thus associated with lower sports group participation among older Japanese, though this may be attenuated by education. These findings suggest that it may be necessary to consider childhood SEP and the importance of education to increase sports group participation at an older age.

Abstract Background The purpose of the study was to explore the single and combined contributions of body mass index (BMI) and lower extremity performance as modifiable physical factors, and the influence of use of a private car as an environmental factor on prevalent and incident life-space restriction in community-dwelling older people. Methods Community-dwelling people aged 75–90 years (n = 823) participated in the Life-Space Mobility in Old Age (LISPE) two-year follow-up study. Participants who reported that the largest life-space area they had attained, without aid from any device or another person, was the neighborhood or less were considered to have life-space restriction. Incident life-space restriction was the endpoint of Cox’s proportional hazard model. BMI, lower extremity performance (Short Physical Performance Battery, SPPB), and use of a private car were predictors. Results At baseline, people who had both obesity (BMI ≥30.0) and impaired lower extremity performance (SPPB 0–9) had a higher prevalence of life-space restriction (prevalence ratio 3.6, 95% confidence interval, CI, 2.0–6.3) compared to those with normal weight (BMI 23.0–24.9) and intact physical performance (SPPB 10–12). The 581 people without life-space restriction at the baseline contributed 1033 person-years during the two-year follow-up. Incident life-space restrictions were reported by 28.3% participants. A higher hazard ratio (HR) for incident life-space restriction was observed in subjects having both obesity and impaired lower extremity performance (HR 3.6, 95% CI, 1.7–7.4), impaired lower extremity performance only (HR 1.9, 95% CI 0.9–4.1), and obesity only (HR 1.8, 95% CI, 0.9–3.5) compared to those with normal weight and intact performance. Private car passengers (HR 2.0, 95% CI, 1.3–3.0) compared to car drivers had a higher risk of life-space restriction. All models were adjusted for age, sex, chronic diseases, and education. Conclusions Older people with impaired lower extremity performance have an increased risk of incident life-space restriction especially if combined with obesity. Also, not driving a car renders older people vulnerable to life-space restriction.

Abstract Background Educational attainment is associated with physical activity among older people. However, little is known about its association with sedentary lifestyle in European as well as Asian nations. This study aims to examine the associations between educational attainment and daily television viewing as an indicator of a sedentary lifestyle among older working and retired people in Finland and Japan. Methods We used cross-sectional harmonized data from two cohorts, the Finnish Public Sector study (n = 10,744) and the Japan Gerontological Evaluation Study (n = 2493), evaluating individuals aged 65–75 years old. We defined high-duration television viewing as ≥4 h per day. Poisson regression was used to examine the association between educational attainment and high-duration television viewing, stratified by the current working status. Models were adjusted for age, sex, household size, smoking, alcohol, body mass index, chronic diseases, mental disorders, and physical activity. Results Of the participants, 27% in Finland and 30% in Japan reported high-duration television viewing. Compared with a low education (≤9 years), Finnish and Japanese retirees with a high education (≥13 years) had less high-duration television viewing [prevalence ratio, PR 0.68 (95% confidence interval 0.63–0.73) and 0.66 (0.55–0.79), respectively]. The corresponding PRs for Finnish and Japanese retirees with intermediate education were also lowered [0.89 (0.83–0.95) and 0.79 (0.68–0.91), respectively]. Among older people still at work, educational attainment was associated with high-duration television viewing among the Japanese but not among the Finnish. Conclusion A similar association between educational attainment and high-duration television viewing in Finland and Japan particularly after retirement suggests a robust and consistent impact of educational attainment on a sedentary lifestyle after retirements.

Abstract Background Several previous studies reported social participation may reduce the incident of dementia; therefore, the type of positions held in the organization may relate to dementia onset. However, this hypothesis remains largely unknown. The purpose of the present study was to examine the additive effect of a leadership position in the organization on dementia onset and social participation among elderly people in a local community, according to data from a Japanese older adults cohort study. Methods Of 29,374 community-dwelling elderly, a total of 15,313 subjects responded to the baseline survey and were followed-up from November 2003 to March 2013. To evaluate the association between dementia onset and social participation as well as the role in the organization, we conducted Cox proportional hazard regression analysis with multiple imputation by age group (aged 75 years older or younger). The dependent variable was dementia onset, which was obtained from long-term care insurance data in Japan; independent variables were social participation and the role in the organization to which they belonged (head, manager, or treasurer). Covariates were sex, age, educational level, marriage status, job status, residence status, alcohol consumption, smoking status, and walking time, instrumental activities of daily living, depression, and medical history. Results During the follow-up period, 708 young-old elderly people (7.7%) and 1289 old-old elderly people (27.9%) developed dementia. In young-old elderly, relative to social non-participants, adjusted Hazard Ratio (HR) for dementia onset for participants (regular members + leadership positions) was 0.75 (95% confidence interval (CI), 0.64–0.88). Relative to regular members, adjusted HR for dementia onset for non-participants was 1.22 (95% CI, 1.02–1.46), for leadership positions 0.81 (95% CI, 0.65–0.99). The results for old-old elderly participants did not show that any significantly adjusted HR between dementia onset and social participation, the role in the organization. Conclusions In young-old elderly people, social participation might have a positive effect on dementia onset, and holding leadership positions in organization could lead to a decrease in risk of dementia onset by almost 20% than regular members.

This study protocol introduces the Kasama Study, a mid-sized longitudinal study of health, fitness, and physical activity in older people. The study is a challenging research project that discusses the future of the system for preventive nursing care and for supporting successful aging in Japan. In May 2008, we began the Kasama Study with an exercise program of preventive nursing care for community-dwelling older adults. As of March 2016, we have conducted six study projects: 1) the Kasama health checkup for longevity, 2) an all-round exercise class, 3) the volunteer and the circle, 4) an exercise class for men only, 5) an exercise class for improving cognitive and physical function, and 6) the Kasama Iki-iki checklist survey. We describe each project in detail in the present study protocol.

Ground reaction force (GRF) in sit-to-stand (STS) movement is used mainly for evaluating lower extremity muscle strength. We attempted to evaluate not only lower extremity muscle strength, but also balance ability from GRF in STS movement. This study aimed to investigate the relationship between GRF variables, including composite variables, which are the combination of parameters representing lower extremity muscle strength and balance ability, and mobility limitation and falls. This study included 381 community-dwelling older adults (73.8 ± 5.3 years; 45.9% men). We measured the maximal rate of force development over 87.5 ms/body weight (RFD8.75/w) and peak reaction force/body weight (F/w) to evaluate lower extremity muscle strength. We also measured lateral load sway divided by the change in vertical load/second (vx/vw) to evaluate balance ability. We then created composite variables of these variables. To perform logistic regression analysis separated by gender, three groups based on the tertile of each variable were used. Composite variables that comprised the Rv score, which was the combination of RFD8.75/w and vx/vw, and Fv scores, which combined F/w and vx/vw, were especially effective for evaluating the risk of mobility limitation in both genders. In evaluating the fall risk, the Rv and Fv scores of the poor group in women only showed significantly higher odds ratios of 2.74 (95% CI: 1.21 - 6.20) and 3.02 (95% CI: 1.31 - 6.96), respectively. These results suggest that the composite variables, Rv and Fv scores, are superior for evaluating risks of mobility limitation and falls, rather than each single variable.

Background: Ground reaction force parameters in a sit-to-stand (STS) movement can be used to evaluate lower extremity function. Few reports, however, are available on whether the ground reaction force parameters in an STS movement reflect dynamic knee and ankle strength or power. The aims of this study were to examine associations among ground reaction force parameters in an STS movement and isokinetic knee and ankle strength and power in healthy older adults, and to compare associations with the five-times STS test. Methods: The following five ground reaction force parameters were measured in 19 men and 28 women: peak reaction force, two rate of force development (RFD) parameters and two time-related parameters. Results: RFD (Δ90 ms)/body weight correlated significantly with average isokinetic knee extension/flexion power in both sexes (partial-r = 0.39–0.54) and average ankle plantar flexion and dorsiflexion power (partial-r = 0.50 and partial-r = 0.49, respectively), in women. No isokinetic parameters were significantly related to the five-times STS test. Conclusion: Ground reaction force parameters in an STS movement can accurately reflect the dynamic strength and power in the lower limbs, which is approximately equal to or better than the strength and power reflected by the five-times STS test.