Can weekend catch-up sleep decrease the risk of cognitive dysfunction in older adults?

PURPOSE: This study investigated whether weekend catch-up sleep was related to a decreased risk of cognitive dysfunction in older Taiwanese adults by using self-reported diaries and objective accelerometer measurements. METHODS: This cross-sectional study enrolled participants who were aged ≥ 65 years and had the capability to walk independently from a medical center in Taipei City, Taiwan, between September 2020 and December 2022. Self-reported sleep diaries and tri-axial accelerometers were used to record and measure sleep-related data for 7 consecutive nights. Weekend catch-up sleep was defined as the mean of weekend sleep time minus the mean of weekdays sleep time. Mini-Mental State Examination (MMSE) was evaluated the risk of cognitive dysfunction. The association between weekend catch-up sleep and the MMSE score was examined using a binary logistic regression model. RESULTS: A total of 215 older adults (53.0% female; 80.5 ± 7.1 years old; 11.6% at risk of cognitive dysfunction) were included. In the adjusted model (adjusted for sex, education level, moderate-to-vigorous physical activity and total accelerometer wear time), both the self-reported sleep diaries (odds ratio [OR] = 0.26, 95% confidence interval [CI] = 0.09-0.69, P = 0.007) and the accelerometer data (OR = 0.27, 95% CI = 0.10-0.70, P = 0.007) indicated that weekend catch-up sleep could decrease the risk of cognitive dysfunction by 73-74%. CONCLUSION: The study findings suggest that there is an association between weekend catch-up sleep and lower risk for cognitive decline. The causal relationship between weekend catch-up sleep and cognitive function in older adults should be further investigated in a study with longitudinal design.

Cross-sectional association of physical activity levels with risks of sarcopenia among older Taiwanese adults.

OBJECTIVES: The updated World Health Organization 2020 guidelines strongly recommend an optimal physical activity level of 150-300 min/week for older adults. However, few studies have examined the relationship between different levels of physical activity and sarcopenia. Therefore, the purpose of this study was to investigate the cross-sectional associations between overall physical activity levels, gender, intensity, and the risk of sarcopenia among older Taiwanese adults. METHODS: A nationwide cross-sectional telephone survey of older adults (≥ 65 years) was conducted in Taiwan from October 2019 to January 2020. Participants were interviewed to collect self-reported data on their level of physical activity (measured by the Taiwanese version of the IPAQ-SF), sarcopenia risk (measured by the SARC-F questionnaire), and sociodemographics. RESULTS: A total of 1068 older adults were surveyed. Compared with the optimal physical activity level recommendations in the WHO guidelines and after adjusting for potential confounders and proposing an association independent of sedentary behavior, older adults with insufficient physical activity levels (< 150 min/week) were more likely to have a higher risk of sarcopenia (OR: 3.24; CI: 1.67-6.27), whereas older adults who exceeded physical activity guidelines (> 300 min/week) were more likely to have a lower risk of sarcopenia (OR: 0.39; CI: 0.20-0.78). Maintaining moderate-intensity physical activity is essential for older adults, as physical activity that exceeds the guidelines can significantly lower the risk of sarcopenia; meanwhile, insufficient physical activity can greatly increase it. Also, there seems to be a similar association between sarcopenia risk across different physical activity levels in vigorous-intensity physical activities in older adults. However, due to the small number of sarcopenia-risk participants who met or exceeded vigorous-intensity physical activity levels, further comparisons between different vigorous-intensity physical activity levels did not show significant differences in sarcopenia risk. Additionally, insufficient physical activity was found to be an important risk factor for sarcopenia in both genders, while physical activity that exceeded the guidelines prevented sarcopenia in females. CONCLUSIONS: The findings of this study highlight the potential dose-response relationship related to physical activity. The 2020 WHO guidelines provide the public with minimum recommendations for physical activity. However, exceeding these recommended levels appears to be more effective in preventing sarcopenia in older adults and may offer even greater health benefits. Future research should further explore whether exceeding these guidelines could result in additional health benefits.

Domain-specific Physical Activity and the Risk of All-cause Mortality Among Middle-aged and Older Adults in Taiwan: A Prospective Cohort Study.

BACKGROUND: The impact of meeting leisure-time physical activity (LTPA) recommendations and household physical activity (HPA) on all-cause mortality in the Taiwanese population is unclear. We aimed to investigate the relationship between sufficient LTPA and all-cause mortality in middle-aged and older Taiwanese adults and the role of HPA in those with insufficient LTPA. METHODS: This nationwide prospective cohort study included 4,960 participants aged ≥50 years from the Taiwan Longitudinal Study in Aging (TLSA) survey. Physical activity patterns were assessed in 2003 and then followed up until 2015 for mortality through the National Death Registration Record. Cox proportional hazards regression was conducted to evaluate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality. RESULTS: Of the 4,960 participants, 1,712 died of all-cause mortality. Compared to those who had insufficient LTPA, participants who engaged in sufficient LTPA showed a significantly lower risk of all-cause mortality (HR = 0.84, 95% CI, 0.73-0.97). For those with insufficient LTPA, HPA also had a significantly reduced risk of all-cause mortality (HR = 0.85, 95% CI, 0.75-0.96) among general population. Similar associations were observed in subsequent sensitivity analyses. The subgroup analysis showed that the relationship between HPA and reduced mortality risk was only found in the women with insufficient LTPA group. CONCLUSION: This study confirmed that sufficient LTPA is associated with a lower risk of all-cause mortality. If sufficient LTPA cannot be performed, additional HPA is related to lower mortality.

Effect of isotemporal substitution of sedentary behavior with different intensities of physical activity on the muscle function of older adults in the context of a medical center.

BACKGROUND: Engaging in physical activity and reducing sedentary time in daily life may enable older individuals to maintain muscle mass. This study aimed to investigate the effects of replacing sedentary behavior with light physical activity (LPA) or moderate-to-vigorous physical activity (MVPA) on the muscle function of older adults at a medical center in Taiwan. METHODS: We recruited 141 older adults (51.1% men; 81.1 ± 6.9 years old) and asked them to wear a triaxial accelerometer on the waist to measure their sedentary behavior and physical activity. Functional performance was assessed based on handgrip strength, Timed Up and Go (TUG) test, gait speed, and five-times-sit-to-stand test (5XSST). Isotemporal substitution analysis was performed to examine the effect of substituting 60 min of sedentary time with 60 min of LPA, MVPA, and combined LPA and MVPA in different proportions. RESULTS: Reallocating 60 min of sedentary behavior per day to LPA was associated with better handgrip strength (Beta [B] = 1.587, 95% confidence interval [CI] = 0.706, 2.468), TUG test findings (B = -1.415, 95% CI = -2.186, -0.643), and gait speed (B = 0.042, 95% CI = 0.007, 0.078). Reallocating 60 min of sedentary behavior per day to MVPA was associated with better gait speed (B = 0.105, 95% CI = 0.018, 0.193) and 5XSST findings (B = -0.060, 95% CI = -0.117, -0.003). In addition, each 5-min increment in MVPA in the total physical activity replacing 60 min of sedentary behavior per day resulted in greater gait speed. Replacing 60 min of sedentary behavior with 30-min of LPA and 30-min of MVPA per day significantly decreased the 5XSST test time. CONCLUSION: Our study indicates that introducing LPA and a combination of LPA and MVPA to specifically replace sedentary behavior may help maintain muscle function in older adults.

Associations of accelerometer-measured sedentary behavior and physical activity with sleep in older adults.

BACKGROUND: Few studies have examined the non-linear relationships of objectively-measured sedentary behavior and physical activity with insomnia symptoms in older adults. We investigated such relationships of sedentary and physically-active behaviors with total sleep time and nocturnal wakefulness. METHODS: We recruited adults aged 60 years and above who have received health check-ups or been to geriatric outpatient services from a hospital setting. Sedentary and physically-active behaviors, total sleep time, and wakefulness time after sleep onset were measured by Actigraphy, and their relationships were estimated using generalized additive models. RESULTS: The 157 older adults receiving health-related services slept 7.5 h (20.8 min awake) on average per day. Total sleep time was negatively associated with sedentary and physically-active behaviors. By contrast, a U-shape relationship was found between sedentary behavior and wakefulness time after sleep onset, with a turning point at a daily sedentary time of 10.9 h. CONCLUSION: Longer high-intensity physical activity time was related to a shorter wakefulness time after sleep onset. By contrast, daily sedentary time longer than 10.9 h was related to shorter total sleep time but more nocturnal wakefulness time. Future nonpharmacological strategies for sleep improvement should consider the sedentary threshold.

Associations of the audited residential neighborhood built-environment attributes with objectively-measured sedentary time among adults: a systematic review.

This study systematically reviewed the relevant studies and summarized the associations of objective measures of residential neighborhood built-environment attributes with sedentary time among adults. Published studies were obtained from PubMed and Scopus, restricting to those published in English language peer-reviewed journals to Oct. 2021. There were nine studies and 48 instances of estimated associations. Most instances showed no statistical-significant associations; by contrast, few instances showed that adults living in a neighborhood characterized by a high density of local destinations and connected intersections were associated with less sedentary time. The findings suggest that a high density of destinations and street intersections around residence may provide opportunities to transfer and access to services, thus reducing the sedentary time. Future research strengthening the research design and measurements are needed to investigate the potential explanations of the associations between residential neighborhood built environments and sedentary time in adults.

Smart Wearable Device Users' Behavior Is Essential for Physical Activity Improvement.

BACKGROUNDS: This study aimed to explore the effect on physical activity and sedentary behavior of users of wearable devices, and understand the association between physical activity and behavior. METHODS: This study conducted a three-arm, randomized controlled trial for 12 weeks. Healthy adults without experience of using a wearable device were recruited and were randomly assigned to a control group with a mobile app and two experimental groups with different smart wearable devices. Data were collected through questionnaires. RESULTS: No significant effect of group, time, or group-by-time interaction among groups for physical activity, sedentary time, or sleep quality was found. Wearing duration significantly positively predicted changes in low-intensity and total physical activity. The number of times the device was checked negatively predicted a change in sedentary time. CONCLUSIONS: The behavior of wearable device users is an essential factor for successfully increasing physical activity and decreasing sedentary time.

Walking and cycling for health: A multi-group analysis of path models between genders.

AIMS: Walking and cycling are beneficial for urban adults' health. Transport and recreation are modifiable domains of major physical activity resources. The purposes of this study were to explore associations among psychological and environmental factors, walking and cycling behaviours and quality of life by developing a path model and comparing gender differences. DESIGN: A cross-sectional study. METHODS: Participants were community-dwelling healthy urban adults aged 20-65 years. Data were collected between September 2019 and June 2020 by self-reported questionnaires, including health beliefs, the neighbourhood environment, walking and cycling behaviours and the World Health Organization Quality-of-Life Scale. An ANCOVA, chi-squared tests, partial least squares-path model and a multi-group analysis were performed for statistical analyses. RESULTS: In total, 1294 valid responses were received, which included 41.27% men and 58.73% women. Men had lower walking behaviours and better self-efficacy than women. The developed path model indicated an acceptable model fit. Significant path coefficients were found among psychological and environmental factors, walking and cycling behaviours and quality of life. The path model between men and women found no significant differences in any path coefficients. Significant path coefficients of environmental factors with cycling behaviour and of walking behaviour with quality of life were found in men but not in women. CONCLUSION: Improving individuals' health beliefs, self-efficacy and perceived walkability and cyclability is a beneficial strategy for promoting physical activity. Walking and cycling behaviours are recommended to improve the quality of life of urban adult populations. IMPACTS: What problem did the study address? A large proportion of urban adult populations still have insufficient physical activity globally. It is essential that implications from an overall perspective of psychological and environmental factors and their interactions be integrated to develop efficient strategies for promoting physical activity and quality of life. What were the main findings? The developed path model with an acceptable model fit found that psychological and environmental factors were important in explaining urban adults' walking and cycling behaviours and quality of life. Differences were not found between men's and women's path models. Where and on whom will the research have impact? Improving urban adults' psychological and environmental factors might be an efficient strategy for promoting sufficient physical activity. Men's low engagement in walking behaviours should garner increased attention. Providing equal opportunities for both genders to engage in walking and cycling behaviours are recommended for health promotion in urban regions.

Phosphatidylinositol-4-phosphate 5-kinase type 1α attenuates Aß production by promoting non-amyloidogenic processing of amyloid precursor protein.

Alzheimer's disease (AD) is characterized by a chronic decline in cognitive function and is pathologically typified by cerebral deposition of amyloid-ß peptide (Aß). The production of Aß is mediated by sequential proteolysis of amyloid precursor protein (APP) by ß- and γ-secretases, and has been implicated as the essential determinant of AD pathology. Previous studies have demonstrated that the level of phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] in the membrane may potentially modulate Aß production. Given that PI(4,5)P2 is produced by type 1 phosphatidylinositol-4-phosphate 5-kinases (PIP5Ks), we sought to determine whether the level of PIP5K type Iα (PIP5K1A) can affect production of Aß by modulating the lipid composition of the membrane. Using a HEK-derived cell line that constitutively expresses yellow fluorescent protein-tagged APP (APP-YFP), we demonstrated that overexpression of PIP5K1A results in significant enhancement of non-amyloidogenic APP processing and a concomitant suppression of the amyloidogenic pathway, leading to a marked decrease in secreted Aß. Consistently, cells overexpressing PIP5K1A exhibited a significant redistribution of APP-YFP from endosomal compartments to the cell surface. Our findings suggest that PIP5K1A may play a critical role in governing Aß production by modulating membrane distribution of APP, and as such, the pathway may be a valuable therapeutic target for AD.

Students' perceptions of school sugar-free, food and exercise environments enhance healthy eating and physical activity.

OBJECTIVE: The objective of this study was to examine the relationships between students' perceptions of their school policies and environments (i.e. sugar-sweetened beverages (SSB) free policy, plain water drinking, vegetables and fruit eating campaign, outdoor physical activity initiative, and the SH150 programme (exercise 150 min/week at school)) and their dietary behaviours and physical activity. DESIGN: Cross-sectional study. SETTING: Primary, middle and high schools in Taiwan. PARTICIPANTS: A nationally representative sample of 2433 primary school (5th-6th grade) students, 3212 middle school students and 2829 high school students completed the online survey in 2018. RESULTS: Multivariate analysis results showed that after controlling for school level, gender and age, the students' perceptions of school sugar-free policies were negatively associated with the consumption of SSB and positively associated with consumption of plain water. Schools' campaigns promoting the eating of vegetables and fruit were positively associated with students' consumption of vegetables. In addition, schools' initiatives promoting outdoor physical activity and the SH150 programme were positively associated with students' engagement in outdoor physical activities and daily moderate-to-vigorous physical activity. CONCLUSIONS: Students' perceptions of healthy school policies and environments promote healthy eating and an increase in physical activity for students.

Is achieving 7,000 steps/day cross-sectionally and prospectively associated with older adults' lower-extremity performance?

BACKGROUND: Evidence regarding the association between daily steps recommendation and older adults' lower limb strength is lacking; thus, this study investigated whether taking at least 7,000 steps/day is cross-sectionally and prospectively related to lower-extremity performance in older Taiwanese adults. METHODS: There were 89 community-dwelling adults aged over 60 years (mean age: 69.5 years) attending both baseline and follow-up surveys. This study used adjusted logistic regression analysis to explore cross-sectional and prospective relationships between their accelerometer-assessed daily steps and lower-extremity performance (five-times-sit-to-stand test). RESULTS: This study found the older adults who took 7,000 steps/day were more likely to have better lower-extremity performance cross-sectionally (odds ratio [OR] = 3.82; 95 % confidence interval [CI]: 1.04, 13.95; p = 0.04), as well as to maintain or increase their lower-extremity performance prospectively (OR = 3.53; 95 % CI: 1.05, 11.84; p = 0.04). CONCLUSIONS: Our findings support a minimum recommended level of step-based physical activity for older adults, namely, 7,000 steps/day, as beneficial for maintaining or increasing older adults' lower-extremity performance.

Workplace neighbourhood built environment and workers' physically-active and sedentary behaviour: a systematic review of observational studies.

BACKGROUND: Many desk-based workers can spend more than half of their working hours sitting, with low levels of physical activity. Workplace neighbourhood built environment may influence workers' physical activities and sedentary behaviours on workdays. We reviewed and synthesised evidence from observational studies on associations of workplace neighbourhood attributes with domain-specific physical activity and sedentary behaviour and suggested research priorities for improving the quality of future relevant studies. METHODS: Published studies were obtained from nine databases (PubMed, Web of Science, PsycINFO, Scopus, Transport Research International Documentation, MEDLINE, Cochrane, Embase, and CINAHL) and crosschecked by Google Scholar. Observational studies with quantitative analyses estimating associations between workplace neighbourhood built environment attributes and workers' physical activity or sedentary behaviour were included. Studies were restricted to those published in English language peer-reviewed journals from 2000 to 2019. RESULTS: A total of 55 studies and 455 instances of estimated associations were included. Most instances of potential associations of workplace neighbourhood built environment attributes with total or domain-specific (occupational, transport, and recreational) physical activity were non-significant. However, destination-related attributes (i.e., longer distances from workplace to home and access to car parking) were positively associated with transport-related sedentary behaviour (i.e., car driving). CONCLUSIONS: The findings reinforce the case for urban design policies on designing mixed-use neighbourhoods where there are opportunities to live closer to workplaces and have access to a higher density of shops, services, and recreational facilities. Studies strengthening correspondence between the neighbourhood built environment attributes and behaviours are needed to identify and clarify potential relationships. PROTOCOL REGISTRATION: The protocol of this systematic review was registered on the International Prospective Register of Systematic Reviews (PROSPERO) on 2 December 2019 (registration number: CRD42019137341 ).

Device-measured light-intensity physical activity and mortality: A meta-analysis.

INTRODUCTION: The association of light-intensity physical activity (LPA) with mortality is poorly understood. This meta-analysis of cohort studies aimed to examine the dose-response relationships between daily device-measured LPA and mortality in adults aged 18 or older and to explore whether the associations were independent of moderate-to-vigorous physical activity (MVPA). METHODS: Searches for prospective cohort studies providing effect estimates of daily LPA (exposure) on all-cause mortality (outcome) were systematically undertaken in electronic databases up to April 30, 2019. Subgroup analyses and meta-regression analyses with random-effects models were performed to quantify the dose-response relationships between daily LPA and mortality. Sensitivity analyses were also conducted to assess the stability of the results. RESULTS: A total of 11 studies were included in the meta-analysis. Analyses contained 49 239 individuals (mean age 60.7, SD = 13.6) who were followed up for a mean 6.2 years (2.3-14.2 years), during which 3669 (7.5%) died. In comparison with the reference group (<3 h/d), the pooled HRs (and 95% CIs) of mortality were 0.71 (0.62-0.82), 0.68 (0.59-0.79), 0.56 (0.44-0.71) for groups 3 to <5 h/d, 5 to <7 h/d, and more than 7 hours a day LPA, respectively. Meta-regression models indicated that there was a log-cubic dose-response relationship between daily LPA and mortality in adults and older people, independent of MVPA. CONCLUSIONS: Time spent in daily LPA was associated with reduced risks of mortality in adults and older people. These data support the inclusion of LPA in the future physical activity guidelines.

ErbB2 regulates autophagic flux to modulate the proteostasis of APP-CTFs in Alzheimer's disease.

Proteolytic processing of amyloid precursor protein (APP) C-terminal fragments (CTFs) by γ-secretase underlies the pathogenesis of Alzheimer's disease (AD). An RNA interference screen using APP-CTF [99-residue CTF (C99)]- and Notch-specific γ-secretase interaction assays identified a unique ErbB2-centered signaling network that was predicted to preferentially govern the proteostasis of APP-C99. Consistently, significantly elevated levels of ErbB2 were confirmed in the hippocampus of human AD brains. We then found that ErbB2 effectively suppressed autophagic flux by physically dissociating Beclin-1 from the Vps34-Vps15 complex independent of its kinase activity. Down-regulation of ErbB2 by CL-387,785 decreased the levels of C99 and secreted amyloid-ß in cellular, zebrafish, and mouse models of AD, through the activation of autophagy. Oral administration of an ErbB2-targeted CL-387,785 for 3 wk significantly improves the cognitive functions of APP/presenilin-1 (PS1) transgenic mice. This work unveils a noncanonical function of ErbB2 in modulating autophagy and establishes ErbB2 as a therapeutic target for AD.

The Associations between Near Visual Activity and Incident Myopia in Children: A Nationwide 4-Year Follow-up Study.

OBJECTIVE: This nationwide population-based study aimed to examine the prospective association between near visual activities and incident myopia in Taiwanese children 7 to 12 years old over a 4-year follow-up period. DESIGN: Prospective cohort design. PARTICIPANTS: There were 1958 children aged 7 to 12 years from the Taiwan 2009 National Health Interview Survey who were linked to the 2009 through 2013 claims data from the National Health Insurance system. METHODS: Multivariable Cox proportional hazard models were used to estimate the associations between 3 types of near visual activities in sedentary posture, namely reading (< 0.5, 0.5-0.9, ≥1.0 hours per day [h/d]), use of computer, Internet, and games (<0.5, 0.5-0.9, ≥1.0 h/d), and "cram school" attendance (<0.5, 0.5-1.9, ≥2.0 h/d), and incident myopia. MAIN OUTCOME MEASURES: Prevalent myopia was defined as those who had ≥2 ambulatory care claims (International Classification of Diseases code 367.1) in 2008-2009. Incident myopia was defined by those who had at least 2 ambulatory care claims (International Classification of Diseases code 367.1) during the 4-year follow-up period (2010-2013) after excluding prevalent cases. RESULTS: Overall, 26.8% of children had myopia at baseline, and 27.7% of those without myopia at baseline developed incident myopia between 2010 and 2013. On average, they spent 0.68±0.86 h/d on computer/Internet use, 0.63±0.67 h/d on reading, and 2.78±3.53 h/d on cram school. The results showed that children attending cram schools ≥2 h/d (hazard ratio, 1.31; 95% confidence interval, 1.03-1.68) had a higher risk of incident myopia. The effects of these activities remained similar in sensitivity analyses. CONCLUSIONS: Cram school attendance for ≥2 h/d may increase the risk of children's incident myopia. This effect may be due to increased near visual activity or reduced time outdoors.

A cut-off of daily sedentary time and all-cause mortality in adults: a meta-regression analysis involving more than 1 million participants.

BACKGROUND: The appropriate limit to the amount of daily sedentary time (ST) required to minimize mortality is uncertain. This meta-analysis aimed to quantify the dose-response association between daily ST and all-cause mortality and to explore the cut-off point above which health is impaired in adults aged 18-64 years old. We also examined whether there are differences between studies using self-report ST and those with device-based ST. METHODS: Prospective cohort studies providing effect estimates of daily ST (exposure) on all-cause mortality (outcome) were identified via MEDLINE, PubMed, Scopus, Web of Science, and Google Scholar databases until January 2018. Dose-response relationships between daily ST and all-cause mortality were examined using random-effects meta-regression models. RESULTS: Based on the pooled data for more than 1 million participants from 19 studies, the results showed a log-linear dose-response association between daily ST and all-cause mortality. Overall, more time spent in sedentary behaviors is associated with increased mortality risks. However, the method of measuring ST moderated the association between daily ST and mortality risk (p < 0.05). The cut-off of daily ST in studies with self-report ST was 7 h/day in comparison with 9 h/day for those with device-based ST. CONCLUSIONS: Higher amounts of daily ST are log-linearly associated with increased risk of all-cause mortality in adults. On the basis of a limited number of studies using device-based measures, the findings suggest that it may be appropriate to encourage adults to engage in less sedentary behaviors, with fewer than 9 h a day being relevant for all-cause mortality.

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.

Prospective relationship between objectively measured light physical activity and depressive symptoms in later life.

BACKGROUND: The use of self-report measures of physical activity is a serious methodological weakness in many studies of physical activity and depressive symptoms. It is still equivocal whether light physical activity protects older adults from depressive symptoms. OBJECTIVE: This study aimed to explore whether objectively measured light physical activity, independent of sedentary and moderate-to-vigorous activity, is associated with a reduced risk of subsequent depressive symptoms in older adults. METHODS: This was a 2-year prospective cohort study. A total of 285 community-dwelling older adults aged 65 years or older were interviewed in 2012. A second wave of assessment was carried out in 2014 involving 274 (96.1%) participants. Time spent in physical activity at different intensities was assessed using triaxial accelerometers. Depressive symptoms were measured using the 15-item Geriatric Depression Scale. Negative binomial regression models with adjustment for baseline depressive symptoms, accelerometer wear time, socio-demographic variables, lifestyle behaviors, and chronic disease conditions were conducted. RESULTS: Time spent in moderate-to-vigorous and light physical activities were both inversely related to depressive symptoms at follow-up. Sedentary time was associated with an increased risk of subsequent depressive symptoms. When sedentary or moderate-to-vigorous activity were included in the multivariable-adjusted regression models with light physical activity simultaneously, only light physical activity remained significant. Sensitivity analyses for assessing confounding and reverse causation provided further support for the stability of these findings. CONCLUSION: Light physical activity, independent of sedentary and moderate-to-vigorous activity, is associated with a reduced risk of subsequent depressive symptoms in later life. Copyright © 2017 John Wiley & Sons, Ltd.

Personal and behavioral correlates of total and domain-specific sedentary behaviors in older Taiwanese adults.

BACKGROUND: Evidence of the harmful health effects of sedentary behavior is emerging; however, little is known about domain-specific sedentary behavior correlates. Thus, in this study, the personal and behavioral correlates of total and domain-specific sedentary behavior in older Taiwanese adults were identified. METHOD: The sample comprised 1046 older adults (aged ≥65 years). Cross-sectional data on self-administered personal behavioral variables and time spent engaging in domain-specific sedentary behavior were obtained using computer-assisted telephone-based interviews. Binary logistic regression analyses were performed. RESULTS: Those aged older than 75 years were less likely to have longer total sedentary, computer use, and transportation times. Compared to women, older men were more likely to have longer total sedentary and transportation times. Older adults with low educational levels were less likely to have longer total sedentary and computer use times but were more likely to have an excessive television (TV) viewing time (≥2 h/day). Older adults who lived alone and were overweight had a longer TV viewing time. Furthermore, unemployment was associated with an excessive TV viewing time and shorter transportation time. Older adults residing in nonmetropolitan areas had lower total sedentary, TV viewing, and computer use times. Older adults who engaged in insufficient leisure time physical activity were more likely to have longer total sedentary and transportation times. CONCLUSIONS: Both common and distinct personal and behavioral factors were associated with total and domain-specific sedentary behavior. Interventions for reducing total and domain-specific sedentary behavior should focus on both common and distinct subgroups of the Taiwanese older population.

Dog ownership, dog walking, and leisure-time walking among Taiwanese metropolitan and nonmetropolitan older adults.

BACKGROUND: This study examined the prevalence of dog ownership and dog walking and its association with leisure-time walking among metropolitan and nonmetropolitan older adults. METHODS: A telephone-based cross-sectional survey targeting Taiwanese older adults was conducted in November 2016. Data related to dog ownership, time spent dog walking (categorized as non-dog owner, non-dog walkers, and dog walkers), and sociodemographic variables were obtained from 1074 older adults. Adjusted binary logistic regression was then performed. RESULTS: In this sample, 12% of Taiwanese older adults owned a dog and 31% of them walked their dogs for an average of 232.13 min over 5.9 days/week (standard deviation = 2.03). Older adults living in nonmetropolitan areas were more likely to own a dog (14.7% vs. 9.1%) but less likely to walk their dog (25.9% vs. 39.6%) than were those living in metropolitan areas. Compared with non-dog owners, only older adults living in nonmetropolitan areas who were dog walkers achieved 150 min of leisure-time walking (odds ratio: 3.03, 95% confidence interval: 1.05-8.77), after adjustment for potential confounders. CONCLUSION: Older Taiwanese adults living in nonmetropolitan areas who owned and walked their dogs were more likely to achieve health-enhancing levels of leisure-time walking. Tailored physical activity interventions for promoting dog walking should be developed for older adults who are dog owners living in nonmetropolitan areas and who do not engage in dog walking.