Active Aging and Public Health: Evidence, Implications, and Opportunities.

By 2050, 20% of the world's population will be over the age of 65 years, with projections that 80% of older adults will be living in low- to middle-income countries. Physical inactivity and sedentary time are particularly high in older adults, presenting unique public health challenges. In this article, we first review evidence that points to multiple beneficial outcomes of active aging, including better physical function, cognitive function, mental health, social health, and sleep, and we suggest the need to shift the research focus from chronic disease outcomes to more relevantoutcomes that affect independence and quality of life. Second, we review the critical role of age-friendly environments in facilitating active aging equitably across different countries and cultures. Finally, we consider emerging opportunities related to social engagement and technology-enabled mobility that can facilitate active aging. In all these contexts, it is a priority to understand and address diversity within the global aging population.

Neighbourhood walkability and dietary attributes: effect modification by area-level socio-economic status.

OBJECTIVE: Higher neighbourhood walkability would be expected to contribute to better health, but the relevant evidence is inconsistent. This may be because residents' dietary attributes, which vary with socio-economic status (SES) and influence their health, can be related to walkability. We examined associations of walkability with dietary attributes and potential effect modification by area-level SES. DESIGN: The exposure variable of this cross-sectional study was neighbourhood walkability, calculated using residential density, intersection density and destination density within 1-km street-network buffer around each participant's residence. The outcome variables were dietary patterns (Western, prudent and mixed) and total dietary energy intake, derived from a FFQ. Main and interaction effects with area-level SES were estimated using two-level linear regression models. SETTING: Participants were from all states and territories in Australia. PARTICIPANTS: The analytical sample included 3590 participants (54 % women, age range 34 to 86). RESULTS: Walkability was not associated with dietary attributes in the whole sample. However, we found interaction effects of walkability and area-level SES on Western diet scores (P < 0·001) and total energy intake (P = 0·012). In low SES areas, higher walkability was associated with higher Western dietary patterns (P = 0·062) and higher total energy intake (P = 0·066). In high SES areas, higher walkability was associated with lower Western diet scores (P = 0·021) and lower total energy intake (P = 0·058). CONCLUSIONS: Higher walkability may not be necessarily conducive to better health in socio-economically disadvantaged areas. Public health initiatives to enhance neighbourhood walkability need to consider food environments and socio-economic contexts.

Associations of Vigorous Gardening With Cardiometabolic Risk Markers for Middle-Aged and Older Adults.

This study investigates the associations of vigorous-intensity gardening time with cardiometabolic health risk markers. This cross-sectional study (AusDiab) analyzed 2011-2012 data of 3,664 adults (55% women, mean [range], age = 59.3 [34-94] years) in Australia. Multiple linear regression models examined associations of time spent participating in vigorous gardening (0, <150 min/week, ≥150 min/week) with a clustered cardiometabolic risk (CMR) score and its components, for the whole sample and stratified by age and gender. Of participants, 61% did no vigorous gardening, 23% reported <150 min/week, and 16% reported ≥150 min/week. In the whole sample, spending ≥150 min/week in vigorous gardening was associated with lower CMR (lower CMR score, waist circumference, diastolic blood pressure, and triglycerides) compared with no vigorous gardening. Stratified analyses suggested that these associations were almost exclusively observed for older adults and women. These findings suggest the public health potential of vigorous-intensity gardening in reducing CMR.

Urban Densification and Physical Activity Change: A 12-Year Longitudinal Study of Australian Adults.

Urbanization, a major force driving changes in neighborhood environments, may affect residents' health by influencing their daily activity levels. We examined associations of population density changes in urban areas with adults' physical activity changes over 12 years using data from the Australian Diabetes, Obesity and Lifestyle Study (1999-2012). The analytical sample contained 2,354 participants who remained at the same residential address throughout the study period in metropolitan cities and regional cities (42 study areas). Census-based population density measures were calculated for 1-km-radius buffers around their homes. Population density change was estimated using linear growth models. Two-level linear regression models were used to assess associations between changes in population density and changes in self-reported walking and physical activity durations. The average change in population density was 0.8% per year (range, -4.1 to 7.8) relative to baseline density. After adjustment for confounders, each 1% annual increase in population density was associated with 8.5-minutes/week (95% confidence interval: 0.6, 16.4) and 19.0-minutes/week (95% confidence interval: 3.7, 34.4) increases in walking and physical activity, respectively, over the 12-year study period. Increasing population density through urban planning policies of accommodating population growth within the existing urban boundary, rather than expanding city boundaries, could assist in promoting physical activity at the population level.

Built Environment, Physical Activity, and Obesity: Findings from the International Physical Activity and Environment Network (IPEN) Adult Study.

Creating more physical activity-supportive built environments is recommended by the World Health Organization for controlling noncommunicable diseases. The IPEN (International Physical Activity and Environment Network) Adult Study was undertaken to provide international evidence on associations of built environments with physical activity and weight status in 12 countries on 5 continents (n > 14,000). This article presents reanalyzed data from eight primary papers to identify patterns of findings across studies. Neighborhood environment attributes, whether measured objectively or by self-report, were strongly related to all physical activity outcomes (accelerometer-assessed total physical activity, reported walking for transport and leisure) and meaningfully related to overweight/obesity. Multivariable indexes of built environment variables were more strongly related to most outcomes than were single-environment variables. Designing activity-supportive built environments should be a higher international health priority. Results provide evidence in support of global initiatives to increase physical activity and control noncommunicable diseases while achieving sustainable development goals.

Sitting at work & waist circumference-A cross-sectional study of Australian workers.

Studies examining associations of sitting time at work with obesity measures have produced inconsistent findings. Different sample characteristics across studies, e.g., the composition of different occupational groups, may be one explanation for the mixed findings. We examined cross-sectional associations of workplace sitting time with waist circumference in workers engaged in desk-based work and those engaged in other work settings using a population-based sample of Australian workers. Participants (5878 full-time workers in the 2014-15 Australian National Health Survey) were categorized into desk-based (N = 3006) or non-desk-based (N = 2872) workers, based on self-reported predominant behavior at work (sitting, standing, walking, and physical labor) and occupational group. Linear regression analyses examined associations of measured waist circumference with self-reported sitting time at work for each group, which was further stratified by gender and leisure-time physical activity level. Longer sitting time at work was associated with greater waist circumference in desk-based workers (b = 0.45 [95%CI: 0.09, 0.80] cm for a 1 h/day increment of sitting) but not in non-desk-based workers (b = 0.25 [95%CI: -0.12, 0.63]). For desk-based workers, stratified analyses found significant associations in men and those who were insufficiently physically active during leisure time. Our findings support interventions to decrease occupational sitting time for desk-based workers to reduce their cardio-metabolic risk. Differential associations observed between desk-based and non-desk-based workers and between genders may be attributable to the ways in which sitting time is accumulated. Future research is needed to examine the impact of behavior patterns at work (sitting breaks, occupational physical activity) on adiposity in working adults.

Is greenery associated with mental health among residents of aged care facilities? A systematic search and narrative review.

Objectives: Older adults living in residential aged care facilities (RACFs) may be vulnerable to mental health issues. Evidence suggests greenery is beneficial for adults' mental health in community settings. This review aims to summarise evidence of associations between greenery in RACFs and residents' mental health.Method: Six databases were searched with three sets of terms related to: (1) exposure (e.g. garden, green); (2) outcome (e.g. mental health, well-being); and (3) setting (e.g. aged care, nursing home). The inclusion criteria were peer-reviewed journal articles published in English up to 2017, reporting quantitative/qualitative associations between greenery and mental health in RACFs.Results: Of the nine articles identified, seven reported positive associations between greenery (in particular, garden use) at RACFs and some aspect of residents' mental well-being (e.g. quality of life); however, four out of seven studies used observations and perceptions of staff and relatives. One study examined depression and reported reduction in depression following garden use, while one examined physiological indicators of stress (blood pressure, heart rate) and found no association with garden use. Seven studies examined garden use and four examined the presence of greenery (two examined both exposures).Conclusion: Exposure to greenery and use of greenspace in RACFs show promise for promoting mental health. However, the findings relied mainly on non-validated measures of mental health. More robust evidence based on valid and reliable mental health measures is needed. Future studies also need to examine the effect of visual exposure to greenery and the effect of greenery on stress reduction.

Associations of Local Social Engagement and Environmental Attributes With Walking and Sitting Among Japanese Older Adults.

This cross-sectional study examined associations of local social engagement with walking and sitting, and whether these associations were modified by local environmental attributes. Older residents (aged 65-84 years, n = 849), recruited from a regional city in Japan, reported walking frequency, sitting time, local social engagement, and local environmental attributes. Walk Score® was also used as an environmental measure. Analysis of data from 705 participants found that engaging in community activities was significantly associated with more frequent walking, but not with prolonged sitting. Interaction analyses between social engagement and environmental attributes did not show any significant interactions, suggesting that promoting local social engagement may increase walking frequency among older adults, regardless of local environmental characteristics. Community-level social initiatives that encourage older adults to participate in local meetings, events, and activities may be an effective physical activity promotion strategy among older adults.

Neighborhood walkability and 12-year changes in cardio-metabolic risk: the mediating role of physical activity.

BACKGROUND: Living in walkable neighborhoods may provide long-term cardio-metabolic health benefits to residents. Little empirical research has examined the behavioral mechanisms in this relationship. In this longitudinal study, we examined the potential mediating role of physical activity (baseline and 12-year change) in the relationships of neighborhood walkability with 12-year changes in cardio-metabolic risk markers. METHODS: The Australian Diabetes, Obesity and Lifestyle study collected data from adults, initially aged 25+ years, in 1999-2000, 2004-05, and 2011-12. We used 12-year follow-up data from 2023 participants who did not change their address during the study period. Outcomes were 12-year changes in waist circumference, weight, systolic and diastolic blood pressure, fasting and 2-h postload plasma glucose, high-density lipoprotein cholesterol, and triglycerides. A walkability index was calculated, using dwelling density, intersection density, and destination density, within 1 km street-network buffers around participants' homes. Spatial data for calculating these measures were sourced around the second follow-up period. Physical activity was assessed by self-reported time spent in moderate-to-vigorous physical activity (including walking). Multilevel models, adjusting for potential confounders, were used to examine the total and indirect relationships. The joint-significance test was used to assess mediation. RESULTS: There was evidence for relationships of higher walkability with smaller increases in weight (P = 0.020), systolic blood pressure (P < 0.001), and high-density lipoprotein cholesterol (P = 0.002); and, for relationships of higher walkability with higher baseline physical activity (P = 0.020), which, in turn, related to smaller increases in waist circumference (P = 0.006), weight (P = 0.020), and a greater increase in high-density lipoprotein cholesterol (P = 0.005). There was no evidence for a relationship of a higher walkability with a change in physical activity during the study period (P = 0.590). CONCLUSIONS: Our mediation analysis has shown that the protective effects of walkable neighborhoods against obesity risk may be in part attributable to higher baseline physical activity levels. However, there was no evidence of mediation by increases in physical activity during the study period. Further research is needed to understand other behavioral pathways between walkability and cardio-metabolic health, and to investigate any effects of changes in walkability.

Associations of local-area walkability with disparities in residents' walking and car use.

Research has examined spatial distribution of physical activity, mostly focusing on between-area differences by examining associations of area-level walkability measures with physical activity. Within-area distribution is also relevant, since larger disparities in physical activity within an area can contribute to greater inequalities in health. However, associations of within-area disparity in walking and walkability have been examined only at a large geographical scale (city level). This cross-sectional study examined associations of local-area walkability measures with within-area disparities in residents' walking and car use, using data collected in the 2009 South-East Queensland Travel Survey in Australia. For each Statistical Area 2 (SA2), we calculated disparity indices of the duration of walking and car use among participants aged 18-84 years, using Gini coefficients. Linear regression examined associations of the disparity measures with population density, street connectivity, and Walk Score. Analyses were conducted for 196 SA2s, which contained 15,895 participants. Higher walkability was associated with lower levels of disparity in walking and higher levels of disparity in car use, regardless of the measures used. Each one-SD increment in Walk Score was associated with a 0.64 lower SD in walking disparity and a 0.50 higher SD in car-use disparity, after adjusting for covariates. The associations remained significant after further adjusting for car ownership. Higher walkability is known to be associated with more walking and less car use. This study extends previous knowledge by showing that higher local-area walkability can be associated with less inequality in residents' walking and higher diversity in their car use.

Objectively-Assessed Patterns and Reported Domains of Sedentary Behavior Among Japanese Older Adults.

BACKGROUND: Prolonged periods of sitting time can be adversely associated with older adults' well-being and functional capacities. Understanding patterns and contexts of sedentary behaviors (SB) can inform approaches to prevention. This study examined Japanese older adults' objectively-assessed patterns and reported domains of SB and their interrelationships. METHODS: Participants (n = 297; aged 65-84 years) of this cross-sectional study wore an accelerometer for 7 days and completed a survey. Five measures related to SB patterns were identified from the accelerometer data. SB from six domains, socio-demographics, and chronic conditions were identified from the survey data. Relative contributions of six domains to objectively-measured prolonged sedentary time (≥30 minutes) and the number of breaks were examined in a series of multivariate linear regressions. Covariates were socio-demographics, chronic conditions, and accelerometer wear time. RESULTS: On average, participants spent 8.8 hours a day sedentary (58% of accelerometer wear time), with 7.6 breaks per sedentary hour, and 3.7 hours a day through prolonged sedentary bouts (4.4 time/day). The proportions of time in the SB domains were 9.4% for car, 4.0% for public transport, 6.1% for work, 45.5% for television (TV) viewing, 9.8% for computer use, and 25.1% for other leisure. Domains of SB that contributed significantly to longer sedentary time through prolonged bouts were TV viewing and computer use. TV viewing was also associated with a lesser number of breaks. CONCLUSIONS: For Japanese older adults, initiatives to address SB could focus on breaking-up prolonged periods of SB by encouraging more frequent breaks, especially during TV viewing.

The impact of a new exercise facility on physical activity at the community level: a non-randomized panel study in Japan.

BACKGROUND: Considering that building a sports facility is a major investment to promote population health, it is important to understand whether it is effective in increasing the level of physical activity (PA) in the community. This study examined the impact of building a new multipurpose exercise facility on community-level PA in Japan. METHODS: This non-randomised panel study compared two sites: an intervention site where a new exercise facility was built (opened after baseline data collection) and a control site where there was no such additional exercise facility. From each site, 3200 adult residents (aged 30-74 years) were randomly selected at baseline (2013) and at follow-up (2015). The number of participants retained for analysis was 845 at baseline and 924 at follow-up for the intervention site, and 821 at baseline and 1018 at follow-up for the control site. The outcomes were participants' self-reported PA, perceived availability of PA facilities, awareness of others being active, and willingness to engage in PA. We examined the interaction terms between the sites and time of measurement in regression analyses to examine whether the magnitude of change from baseline to follow-up differed between the two sites. RESULTS: The changes in the proportion of participants meeting the PA guideline and those engaging in moderate-to-vigorous intensity PA were not significantly different between the intervention and control sites. The intervention site had a greater increase in the proportion of participants who were aware of PA facilities from baseline to follow-up than in the control site. The odds ratio for awareness of others being active approached significance, suggesting that there was a tendency at the intervention site towards a greater increase in the proportion of participants who noticed physically active people. CONCLUSIONS: This study did not find community-level increases in PA after the construction of the exercise facility. However, a significant improvement in the awareness of PA facilities was observed in the intervention site. A sustained community-level effort to promote PA, possibly including social components, and a further tracking of residents' PA are needed to take a full advantage of the new exercise facility and to assess its long-term impact. TRIAL REGISTRATION: UMIN-CTR UMIN000034116 (retrospectively registered: 13 September 2018).

Are Neighborhood Environmental Attributes More Important for Older Than for Younger Adults' Walking? Testing Effect Modification by Age.

Older adults are often considered more vulnerable to environmental factors than are younger adults. We examined whether the associations of objectively measured environmental attributes (Walk Score; street connectivity) with walking for transport differed between younger- (25-44 years), middle- (45-64 years), and older-aged (65-84 years) adults, using a large Australian sample of 14,656 people. Walk Score and street connectivity were similarly associated with walking (any; 30+ min/day) in all age groups. Contrary to commonly held views, the study did not find any evidence suggesting that older adults may be more sensitive to their environment to get out and walk than are younger adults, at least for the environmental attributes examined in this study. Further research is needed to investigate if there are particular environmental factors that hinder older adults from being active.

Associations of neighbourhood walkability indices with weight gain.

BACKGROUND: Inconsistent associations of neighbourhood walkability with adults' body weight have been reported. Most studies examining the relationships of walkability and adiposity are cross-sectional in design. We examined the longitudinal relationships of two walkability indices - conventional walkability and space syntax walkability, and their individual components, with weight change among adults over four years. METHODS: Data were from the Physical Activity in Localities and Community study in Adelaide, Australia. In 2003-2004, 2650 adults living in 154 Census Collection Districts (CCDs) returned baseline questionnaires; in 2007-2008, the follow-up survey was completed by 1098. Participants reported their weight at baseline and at follow-up. Neighbourhood walkability indices were calculated using geographic information systems and space syntax software. Linear marginal models using generalized estimating equations with robust standard errors were fitted to examine associations of the two walkability indices and their individual components with the weight at follow-up, adjusting for baseline weight, socio-demographic variables, and spatial clustering at the level of CCD. RESULTS: The overall mean weight gain over four years was 1.5 kg. The two walkability indices were closely correlated (r = 0.76, p < 0.01). No significant associations were found between the overall neighbourhood walkability indices and weight change. Among walkability components, there was a marginally significant negative association between space syntax measure of street integration and weight change: one standard deviation increment in street integration was associated with 0.31 kg less weight gain (p = 0.09). CONCLUSIONS: Using a prospective study design and a novel space-syntax based measure of walkability, we were not able to identify relationships between neighbourhood walkability with weight gain. This is consistent with other inconclusive findings on the built environment and obesity. Research on the built environment and adults' weight gain may need to consider not just local environments but also a larger scale environment within a city or workplace environment in order to capture multiple behaviours relevant to weight gain.

Associations of neighborhood environmental attributes with adults' objectively-assessed sedentary time: IPEN adult multi-country study.

Neighborhood environmental attributes have been found to be associated with residents' time spent walking and in physical activity, in studies from single countries and in multiple-country investigations. There are, however, mixed findings on such environmental relationships with sedentary (sitting) time, which primarily have used evidence derived from single-country investigations with self-reported behavioral outcome measures. We examined potential relationships of neighborhood environmental attributes with objectively-assessed sedentary time using data from 5712 adults recruited from higher and lower socio-economic status neighborhoods in 12 sites in 10 countries, between 2002 and 2011. Ten perceived neighborhood attributes, derived from an internationally-validated scale, were assessed by questionnaire. Sedentary time was derived from hip-worn accelerometer data. Associations of individual environmental attributes and a composite environmental index with sedentary time were estimated using generalized additive mixed models. In fully adjusted models, higher street connectivity was significantly related to lower sedentary time. Residential density, pedestrian infrastructure and safety, and lack of barriers to walking were related to higher sedentary time. Aesthetics and safety from crime were related to less sedentary time in women only. The predicted difference in sedentary time between those with the minimum versus maximum composite environmental index values was 71 min/day. Overall, certain built environment attributes, including street connectivity, land use mix and aesthetics were found to be related to sedentary behavior in both expected and unexpected directions. Further research using context-specific measures of sedentary time is required to improve understanding of the potential role of built environment characteristics as influences on adults' sedentary behavior.

Replacing sedentary time with physical activity: effects on health-related quality of life in older Japanese adults.

BACKGROUND: The isotemporal substitution (IS) approach can be used to assess the effect of replacing one activity with the equal duration of another activity on relevant outcomes. This study examined the associations of objectively assessed sedentary behavior (SB) and physical activity (PA) with health-related quality of life (HRQOL) in older Japanese adults, using the IS approach. METHODS: Participants were 287 older Japanese adults (aged 65-84 years) who wore accelerometers for at least 7 days. We calculated the average daily time spent in SB (≤1.5 METs); light-intensity PA (LPA: > 1.5 to < 3.0 METs); and moderate- to vigorous-intensity PA (MVPA: ≥3.0 METs) per day. HRQOL was assessed using the Medical Outcomes Survey Short Form-8 questionnaire. RESULTS: The IS models showed replacing SB or LPA with MVPA to be significantly associated with better physical component summary scores. Replacing SB with MVPA was marginally associated with better mental component summary scores. CONCLUSION: These findings indicate that replacing SB with the same amount of MVPA may contribute to better physical HRQOL in older adults.

Validity and Reliability of Japanese-Language Self-reported Measures for Assessing Adults Domain-Specific Sedentary Time.

BACKGROUND: Good quality measures of Japanese adults' sedentary behaviors are needed to accurately assess correlates of specific sedentary behaviors. The present study assessed criterion validity of total sedentary behavior and test-retest reliability of six domain-specific sedentary behaviors. METHODS: We administered a questionnaire, based on previous studies, that measured domain-specific sedentary behaviors. To examine validity, agreement between self-reported time spent in sedentary behaviors from the questionnaire and objectively-measured sedentary time using accelerometers was compared among 392 adults (aged 40-64 years) in two Japanese cities. For reliability, a 2-week interval test-retest was administered to a convenience sample of 34 participants. RESULTS: The correlation between total self-reported and objectively measured sedentary time was significant (all P < 0.001) and fair-to-good for workdays (ρ = 0.57) and whole week (ρ = 0.49), but was low for non-workdays (ρ = 0.23). The difference between the two measures was significant for whole week (z = -2.25, P = 0.03) and non-workdays (z = -5.50, P < 0.001), but was not significant for workdays (z = -0.60, P = 0.55). There was a significant positive association between the difference in the two measures and the average of these two measures (workdays: r = 0.53; non-workdays: r = 0.45; and whole week: r = 0.54, all P < 0.001). There was fair-to-good test-retest reliability of total sedentary time for each domain (workdays: interclass correlation coefficient [ICC] = 0.77, non-workdays: ICC = 0.53, and whole week: ICC = 0.7; all P < 0.01). CONCLUSIONS: The scale of domain-specific sedentary behaviors is reliable for estimating where and for what purpose Japanese adults spend their sedentary time, and total sedentary time is valid for workdays and the whole week.

Built environmental factors and adults' travel behaviors: Role of street layout and local destinations.

Street layout is consistently associated with adults' travel behaviors, however factors influencing this association are unclear. We examined associations of street layout with travel behaviors: walking for transport (WT) and car use; and, the extent to which these relationships may be accounted for by availability of local destinations. A 24-h travel diary was completed in 2009 by 16,345 adult participants of the South-East Queensland Household Travel Survey, Australia. Three travel-behavior outcomes were derived: any home-based WT; over 30min of home-based WT; and, over 60min of car use. For street layout, a space syntax measure of street integration was calculated for each Statistical Area 1 (SA1, the smallest geographic unit in Australia). An objective measure of availability of destinations - Walk Score - was also derived for each SA1. Logistic regression examined associations of street layout with travel behaviors. Mediation analyses examined to what extent availability of destinations explained the associations. Street integration was significantly associated with travel behaviors. Each one-decile increment in street integration was associated with an 18% (95%CI: 1.15, 1.21) higher odds of any home-based WT; a 10% (95%CI: 1.06, 1.15) higher odds of over 30min of home-based WT; and a 5% (95%CI: 0.94, 0.96) lower odds of using a car over 60min. Local destinations partially mediated the effects of street layout on travel behaviors. Well-connected street layout contributes to active travel partially through availability of more local destinations. Urban design strategies need to address street layout and destinations to promote active travel among residents.

Associations of Neighborhood Environmental Attributes with Walking in Japan: Moderating Effects of Area-Level Socioeconomic Status.

Several studies have examined how the associations of built environment attributes with walking behaviors may be moderated by socioeconomic status (SES). Such understanding is important to address socioeconomic inequalities in health through urban design initiatives. However, to date, there is no study examining the moderation effects of SES in the relationships of environmental attributes and walking in non-Western countries. The current study aims to examine associations of environmental attributes with walking behaviors among Japanese adults, and to test whether these associations were moderated by area-level SES. Data on walking were collected from Japanese adults using a nationwide Internet survey (N = 4605). Built environment measures including population density, street density, distance to the nearest public open space, and distance to the nearest commercial destination were calculated using geographic information systems software. An index of neighborhood deprivation was used as an area-level indicator of SES. Logistic regression models adjusted for clustering and sociodemographic variables were used. It was found that more residents in high SES areas walked for commuting, for errands, and for exercise compared with those who lived in low SES areas. When the whole sample was examined, all environmental attributes were associated with walking behaviors (except for street density not being associated with walking for exercise). Associations of environmental attributes with walking behaviors were moderated by area-level SES only in walking for exercise. Walking for exercise was associated with higher population density, higher street density (marginally significant), and shorter distance to the nearest commercial destination only in high SES areas. Our findings showed that the associations of these environmental attributes and walking behaviors were largely consistent across different SES levels. Therefore, urban design interventions focusing on low SES areas may help to reduce socioeconomic disparities in walking.

Associations of sedentary behavior and physical activity with older adults' physical function: an isotemporal substitution approach.

BACKGROUNDS: The purpose of this study was to examine, in a sample of Japanese older adults, the associations of objectively-assessed sedentary behavior (SB) and physical activity (PA) with performance-based physical function. The isotemporal substitution (IS) approach was used to model simultaneously the effects of the specific activity being performed and the activity being displaced, in an equal time-exchange manner. METHODS: Among 287 older adults (65-84 years), we used accelerometers to identify the daily average time spent on SB (≤1.5 METs); light-intensity PA (LIPA) (>1.5 to <3.0 METs); and moderate- to vigorous-intensity PA (MVPA) (≥3.0 METs). Physical function was assessed using five performance-based measures: hand grip strength, usual and maximum gait speeds, timed up and go, and one-legged stance with eyes open. We employed three linear regression models - a single-activity model, a partition model, and an IS model - to assess the associations of SB, LIPA, and MVPA with each of the five measures of physical function. RESULTS: There were significant positive associations in the single-activity and partition models between MVPA and the measures of physical function (with the exception of hand grip strength). The IS models found that replacing SB or LIPA with MVPA was significantly and favorably associated with physical function measures. CONCLUSIONS: These findings indicate that replacing small amounts of SB and LIPA with MVPA (such as 10 min) may contribute to improvements in older adults' physical function.