Associations between physical function and device-based measures of physical activity and sedentary behavior patterns in older adults: moving beyond moderate-to-vigorous intensity physical activity

Moderate-To-Vigorous Physical Activity Independent of Stationary Time Is Associated With Better Functional Outcomes Over Four-Years in Individuals With or at Risk of Knee Osteoarthritis

INTRODUCTION

Osteoarthritis is a progressive joint disease that causes pain and disability, impairing physical function. Moderate-to-vigorous physical activity (MVPA) is recommended for knee osteoarthritis, while stationary time, independent of activity, may negatively impact health outcomes. We hypothesised that individuals with the highest MVPA and lowest stationary time would have better long-term function compared to those with the lowest MVPA and highest stationary time, as well as those with high levels of both MVPA and stationary time.

METHODS

Data included 442 participants, with an average age of 66-years and 190-females from the Osteoarthritis Initiative who wore accelerometers to assess MVPA and stationary time. Participants were grouped into tertiles of MVPA and stationary time normalised to total accelerometer wear time. The three groups were: highest activity, lowest stationary (HALS), highest activity, highest stationary (HAHS), and lowest activity, highest stationary (LAHS). Gait speed, the 400 m walk test, and five-time repeated chair stand were assessed at baseline and four-year follow-up.

RESULTS

Compared to the LAHS group, the HALS and HAHS groups had better performance in gait speed p < 0.001, d = 0.96-1.06, 400m walk time p < 0.001, d = 1.21-1.36, and five-time repeated chair stand p < 0.001, d = 0.54-0.81 at baseline and four-year follow-up. No differences were found between the HALS and HAHS groups at either timepoint.

CONCLUSION

Higher levels of MVPA were associated with better lower-limb functional outcomes in individuals with or at risk of knee osteoarthritis. Higher levels of stationary time do not negatively influence functional performance as long as higher numbers of MVPA levels (∼30 min/day) are achieved.

Association Between Self-Reported Sitting Time and the Physical Function Domain of the Kihon Checklist Among Community-Dwelling Older Adults

Objective Interventions that reduce sitting time are easier to implement than those that aim to increase physical activity in compliance with the guidelines. There is no consensus on the association between sitting time as assessed by the International Physical Activity Questionnaire (IPAQ) and physical function. We investigated the association between self-reported sitting time and physical function according to the Kihon Checklist (KCL) among community-dwelling older adults. Methods This cross-sectional study included 87 community-dwelling middle-aged and older adults who had participated in a long-term preventive care and health promotion project. The project was conducted three times between March 2023 and March 2024. Sitting time was self-reported using the IPAQ. Physical function was assessed using the KCL. A generalized linear model was used to analyze the association between sitting time and physical function. In the adjusted model, handgrip strength, walking speed, five times sit to stand test, skeletal muscle mass index, living alone, pain, sex, and age were used as covariates to adjust for confounders. Results Eight subjects met the exclusion criteria, leaving a final cohort of 79 community-dwelling older adults (mean age: 75 ± 6 years, 73% female). Our analysis revealed that sitting time was associated with physical function, even after adjusting for covariates (standardized β coefficient = 0.22, p = 0.023). Conclusions Our findings emphasize the usefulness of assessing sitting time to maintain physical function in community-dwelling older adults. Furthermore, it may be important to reduce sitting time to maintain or improve physical function.

Associations between accelerometer-measured physical activity and sedentary behaviour with physical function among older women: a cross-sectional study

BACKGROUND

This study aimed to investigate the relationships between accelerometer-measured physical activity (PA) and sedentary behaviour (SB) with physical function (PF) among older Chinese women in the community.

METHODS

The present study comprised 1,113 community-dwelling older females, with an average age of 65 ± 2 years. We employed a linear regression analysis to investigate the relationship between patterns of PA and SB with PF. PA variables consisted of total PA time, bouted PA time (a continuous PA that lasts equal to or more than 10 min), and sporadic PA time (a continuous PA that lasts less than 10 min). SB variables included total SB time, 30-min bout of SB (a continuous SB that lasts equal to or more than 30 min), and 60-min bout of SB (a continuous SB that lasts equal to or more than 60 min). PF variables comprised handgrip strength (HGS), one-legged stance test with eyes closed (OLSTEC), usual walking speed (UWS), maximum walking speed (MWS) and chair-stand time (CT). To explore the joint effects of moderate-to-vigorous-intensity PA (MVPA) and SB on PF, we divided the duration of SB and MVPA participation in older women into different combinations: low MVPA & high SB, low MVPA & low SB, high MVPA & high SB, high MVPA & low SB.

RESULTS

The study revealed a significant association between 30-min bout of SB and CT, which remained after adjusting for total MVPA time (P = 0.021). Both total MVPA and bouted MVPA were found to be positively associated with better UWS, MWS, CT, and PF Z-score. When the combination of low MVPA & high SB was used as a reference, the regression coefficients for PF ascended by 1.32 (P < 0.001) in the high MVPA & high SB group and by 1.13 (P < 0.001) in the high MVPA & low SB group.

CONCLUSIONS

A significant association was observed between poorer lower limb function and prolonged, uninterrupted SB in older women, rather than with the total SB time. Concurrently, the insufficient engagement in MVPA may also be a crucial factor contributing to poorer PF in older women. Engaging in longer durations and higher intensity of PA, such as bouts of MVPA lasting a minimum of 10 min or longer, may contribute to better PF.

Development of a Conceptual Model of Physical Functioning Limitations Experienced by Patients with Late-Stage Chronic Kidney Disease: A Qualitative Interview Study

INTRODUCTION

Limitations in physical functioning are common in patients with late-stage chronic kidney disease (CKD) and can greatly affect their lives. Using patient interviews, this study reports experiences associated with physical functioning limitations for patients with late-stage CKD.

METHODS

A preliminary conceptual model on concepts relevant to physical functioning limitations in patients with CKD was developed using data from a targeted literature review (patients with CKD stages IV-V) and previous interviews (patients with CKD stages IIIa-IIIb). The preliminary conceptual model informed a semi-structured interview guide designed to capture experiences of physical functioning limitations in patients with CKD. Patients with CKD stages IV-V who were not receiving dialysis were interviewed; their responses were used to develop a comprehensive conceptual model summarizing their experiences associated with physical functioning limitations.

RESULTS

A total of 25 patients with CKD stage IV (n = 19) or V (n = 6) were interviewed. Based on patient responses, the reported concepts were grouped into one of six categories: physical functioning limitations/difficulties, behavioural impacts, activity participation restrictions, symptoms attributed to physical functioning limitations, impacts on sleep and emotional functioning impacts related to physical functioning limitations. Twenty-three patients reported concepts associated with physical functioning limitations, most frequently 'walking up and down stairs' (83%) and 'walking distances' (74%). All 23 patients also reported behavioural impacts, including 'need to rest/subsequent periods of rest' (100%) and 'participation in fewer activities' (91%). As well as summarizing the reported concepts, the comprehensive conceptual model shows how concepts may relate to one another; for example, challenging symptoms or difficulty completing tasks can lead to changes in patient behaviour such as purposely reducing or avoiding activities.

CONCLUSIONS

This study found that patients with late-stage CKD not receiving dialysis who experience physical functioning limitations report a range of impacts on their daily lives. The comprehensive conceptual model summarizes the concepts reported and the relationships between them, providing a holistic understanding of how patients with late-stage CKD are affected by physical functioning limitations. Infographic available for this article. INFOGRAPHIC.

Cross-sectional interactive associations of physical activity and sedentary behaviour with physical capacity across adulthood

BACKGROUND

The way physical activity (PA) and sedentary behaviour (SB) independently and interactively modify the age-related decline in physical capacity remains poorly understood. This cross-sectional study investigated the independent and interactive associations of PA and SB with physical function and performance throughout the adult life course.

METHODS

Data from 499 community-dwelling adults (63% female) aged 20-92 years, involved in the INSPIRE Human Translational Cohort, were used in this cross-sectional study. Daily time spent on moderate-to-vigorous PA (MVPA, min/day) and SB (h/day) was measured with activPAL triaxial accelerometers. Physical function and performance were assessed through the measurement of the 4-m usual gait speed (m/s), handgrip strength (kg), lower-limb strength (isokinetic knee extension torque, N·m), estimated lower-limb power (five-time chair-rise test performance, s) and cardiorespiratory fitness (V̇O2max, mL/kg/min). Confounder-adjusted multiple linear and curvilinear regressions were performed to investigate how MVPA, SB and their interactions were associated with the physical outcomes (all square root-transformed except gait speed) throughout the adulthood spectrum.

RESULTS

Interaction analyses revealed that the combination of higher levels of MVPA with lower levels of SB favourably reshaped the negative relationship between handgrip strength and age (age2 × SB × MVPA: B = -7E-08, SE = 3E-08, P < 0.05). In addition, higher levels of MVPA were independently associated with an improved age-related profile in gait speed (age2 × MVPA: B = 3E-06, SE = 1E-06, P < 0.05), chair-rise performance (age × MVPA: B = -9E-05, SE = 4E-05, P < 0.05) and V̇O2max (MVPA at 21 years: B = 3E-02, SE = 7E-03, P < 0.05; age × MVPA: B = -5E-04, SE = 2E-04, P < 0.05). Conversely, the detrimental association of age with lower-limb muscle strength (age × SB: B = -1E-04, SE = 6E-05, P < 0.05) and chair-rise performance (age × SB: B = 1E-05, SE = 7E-06, P < 0.05) was exacerbated with increasing duration of SB, independently of MVPA. Supplementary analyses further revealed that some of these associations were age and sex specific.

CONCLUSIONS

This cross-sectional study demonstrated that reduced sedentary time and increased activity duration were independently and synergistically associated with an attenuated age-related loss in physical capacity. These findings need to be confirmed with longitudinal data but encourage both adopting an active lifestyle and reducing sedentary time as preventive measures against physical aging.

Daily activity patterns in older adults receiving initial support: the association between daily steps and sitting in bouts of at least 60 min

BACKGROUND

Aging has a significant impact on health, underlining the importance of maintaining physical function and reducing time spent sitting among older adults. To understand how to reduce prolonged sitting or increase physical activity, factors related to the daily living and observed daily activity patterns should be explored. This study aimed to investigate the association between daily steps, self-rated health, physical activity, sedentary behavior, motivation to exercise and fear of falling among older adults receiving initial support.

METHOD

Cross-sectional design with total population questionnaire data from adults aged ≥ 60 years (n = 917), living at home with initial support from municipal care in southern Sweden. The older adults were offered to participate in a follow-up study measuring daily activity patterns with accelerometers (n = 72). Linear regression was used to analyze associations between daily steps and possible predictors.

RESULTS

The linear model ([Formula: see text]0.478) showed that sitting in unbroken bouts of > 60 min (β = -0.313, p < 0.05), walking independently outdoors (β = 0.301, p < 0.05), intending to increase physical activity (β = -0.294, p < 0.05), sex (β = 0.279, p < 0.05), relative autonomy index (β = 0.258, p < 0.05), fear of falling (β = -0.238, p < 0.05), and self-rated health (β = 0.213, p < 0.05) predicted daily steps.

CONCLUSION

The model of predictors brings new understanding regarding daily steps among community-dwelling older adults. The association between sitting in bouts of > 60 min and daily steps is interesting as 35% of participants had a number of sitting bouts that on average, showed 30% less steps taken. Minimizing long sitting bouts and maintaining physical functioning to promote independence when walking outdoors can be tools for clinical practitioners devising interventions to break prolonged sitting among community-dwelling older adults. Future research should prioritize studying older adults' outdoor walking independence, including its relation to walking with or without assistive devices and its impact on physical activity and sedentary behavior.

Individual and environmental variables related to outdoor walking among older adults: Verifying a model to guide the design of interventions targeting outdoor walking

OBJECTIVE

To estimate the relationships between individual and environmental variables and outdoor walking (OW) in older adults with OW limitations through verifying a conceptual model.

METHODS

Baseline data from 205 older adults participating in a randomized trial of a park-based OW program were analyzed using structural equation modeling. We evaluated a three latent factor model: OW (accelerometry and self-report); individual factors (balance; leg strength; walking self-confidence, speed and endurance; mental health; education; income; car access); and environmental factors (neighbourhood walkability components).

RESULTS

Mean age was 75 years; 73% were women. Individual factors was significantly associated with OW (β = 0.39, p < .01). Environmental factors was not directly associated with OW but was indirectly linked to OW through its significant covariance with the individual factors (β = 0.22, p < .01). The standardized factor loadings from the individual factors on walking self-confidence and walking capacity measures exceeded 0.65.

CONCLUSIONS

Better walking capacity and more confidence in the ability to walk outdoors are associated with higher OW in older adults. Better neighbourhood walkability is indirectly associated with more OW. The conceptual model demonstrates an individual and environment association; if the capacity of the individual is increased (potentially through walking interventions), they may be able to better navigate environmental challenges.

A RIEMANN MANIFOLD MODEL FRAMEWORK FOR LONGITUDINAL CHANGES IN PHYSICAL ACTIVITY PATTERNS

Physical activity (PA) is significantly associated with many health outcomes. The wide usage of wearable accelerometer-based activity trackers in recent years has provided a unique opportunity for in-depth research on PA and its relations with health outcomes and interventions. Past analysis of activity tracker data relies heavily on aggregating minute-level PA records into day-level summary statistics in which important information of PA temporal/diurnal patterns is lost. In this paper we propose a novel functional data analysis approach based on Riemann manifolds for modeling PA and its longitudinal changes. We model smoothed minute-level PA of a day as one-dimensional Riemann manifolds and longitudinal changes in PA in different visits as deformations between manifolds. The variability in changes of PA among a cohort of subjects is characterized via variability in the deformation. Functional principal component analysis is further adopted to model the deformations, and PC scores are used as a proxy in modeling the relation between changes in PA and health outcomes and/or interventions. We conduct comprehensive analyses on data from two clinical trials: Reach for Health (RfH) and Metabolism, Exercise and Nutrition at UCSD (MENU), focusing on the effect of interventions on longitudinal changes in PA patterns and how different modes of changes in PA influence weight loss, respectively. The proposed approach reveals unique modes of changes, including overall enhanced PA, boosted morning PA, and shifts of active hours specific to each study cohort. The results bring new insights into the study of longitudinal changes in PA and health and have the potential to facilitate designing of effective health interventions and guidelines.

Determining minimum number of valid days for accurate estimation of sedentary behaviour and awake-time movement behaviours using the ActivPAL3 in nursing home residents

INTRODUCTION

Scarce evidence is available about the minimum number of valid days wearing the activPAL3 to obtain a precise estimate of sedentary behaviour (SB) and awake-time movement behaviours (ATMB) in nursing home (NH) residents. The study aimed to determine the minimum number of valid days required for accurately estimate SB and ATMB using the activPAL3 device in NH residents. It also investigated how the starting point of a day (the 24-h period) impacted reliability.

METHODS

Participants wore an activPAL3 for 7 consecutive days. The data was classified in two-time blocks (00:00 Ante Meridiem (AM)-00:00 AM midnight vs 12:00 Post Meridiam (PM) -12:00 PM midday) and the sample was stratified into two groups according to their capacity to stand and walk, to examine if timing of sampling or physical functioning affected minimum wear time. SB, ATMB, sociodemographic, and health-related variables were collected. Sensitivity of the time-blocks were tested through the dispersion frequencies and differences between blocks through Kolmogorov-Smirnov test for normality; parametric variables through two-related means T-test and Wilcoxon test for non-parametric data. Reliability was assessed with the Cronbach's Alpha and the intra-class correlation coefficient (ICC), using a one-factor model estimating the reliability for each measurement day loading in the same latent factor.

RESULTS

Ninety-five NH residents (81.1% women; age = 85.8 ± 7.2 years) were included. The midnight block had higher reliability, sensitivity and no statistically significant differences between days were found. At least three consecutive days of monitoring were necessary to achieve a reliability of ICC ≥ 0.8 for those NH residents able to stand and walk and six days for those unable.

CONCLUSIONS

NH residents who are able to stand and walk require a minimum of three consecutive days wearing the device, while those who are unable require at least six days due to their highly homogenous daily routines and sensitivity to PA events. Regardless of the activPAL3 recording start time, data processing should reference the midnight time block.

Association of Sit-to-Stand Capacity and Free-Living Performance Using Thigh-Worn Accelerometers among 60- to 90-Yr-Old Adults

PURPOSE

Five times sit-to-stand (STS) test is commonly used as a clinical assessment of lower-extremity functional ability, but its association with free-living performance has not been studied. Therefore, we investigated the association between laboratory-based STS capacity and free-living STS performance using accelerometry. The results were stratified according to age and functional ability groups.

METHODS

This cross-sectional study included 497 participants (63% women) 60-90 yr old from three independent studies. A thigh-worn triaxial accelerometer was used to estimate angular velocity in maximal laboratory-based STS capacity and in free-living STS transitions over 3-7 d of continuous monitoring. Functional ability was assessed with short physical performance battery.

RESULTS

Laboratory-based STS capacity was moderately associated with the free-living mean and maximal STS performance ( r = 0.52-0.65, P < 0.01). Angular velocity was lower in older compared with younger and in low- versus high-functioning groups, in both capacity and free-living STS variables (all P < 0.05). Overall, angular velocity was higher in capacity compared with free-living STS performance. The STS reserve (test capacity - free-living maximal performance) was larger in younger and in high-functioning groups compared with older and low-functioning groups (all P < 0.05).

CONCLUSIONS

Laboratory-based STS capacity and free-living performance were found to be associated. However, capacity and performance are not interchangeable but rather provide complementary information. Older and low-functioning individuals seemed to perform free-living STS movements at a higher percentage of their maximal capacity compared with younger and high-functioning individuals. Therefore, we postulate that low capacity may limit free-living performance.

Sedentary Behavior and Physical Functioning in Middle-Age and Older Adults Living in the United States: The Reasons for Geographic and Racial Differences in Stroke Study

PURPOSE

Sedentary behavior is associated with poor physical function in older adults, which can lead to accelerated skeletal muscle aging (sarcopenia) and premature mortality. We examined the independent and joint effects of sedentary behavior and moderate to vigorous intensity physical activity (MVPA) with measures of physical functioning.

METHODS

We studied 5408 participants in the REasons for Geographic and Racial Differences in Stroke study who wore a hip-mounted accelerometer over seven consecutive days (2009-2013) and had self-reported and directly observed physical function (time walk, chair stand test) measured during an in-home visit conducted from 2013 to 2016.

RESULTS

Greater sedentary time was significantly associated with poorer chair stand and timed walk scores. Substituting 30 min of sedentary time with 30 min of MVPA was associated with significant improvements in chair stands (β -0.57; P = 0.007) and timed walk (β -0.36; P = 0.01). Similar, but less robust, findings were observed for reallocations of sedentary time to light-intensity physical activity. In joint association analyses, high sedentary time in combination with low MVPA (but not in combination with high MVPA) was associated with poorer physical function compared with the referent group (low sedentary time/high MVPA; P < 0.001 for all).

CONCLUSIONS

Greater time spent being sedentary was associated with worse physical functioning outcomes. However, reallocations of sedentary time to light-intensity physical activity, and especially MVPA, were associated with more favorable physical functioning. Interventions aimed to increase MVPA and reduce sedentary behavior should be a priority, especially among populations at greatest risk for sarcopenia and physical function decline.

The Longitudinal Association Between Physical Activity and Physical Function in Older Women

Purpose

The age-related decline in physical function is ameliorated by physical activity; however, less is known about changes in physical function in active vs. inactive older women. The purpose of this study was to determine the longitudinal associations between physical activity and physical function in community-dwelling older women.

Methods

238 participants (age 79.0 ± 5.1) were dichotomized into two activity groups [inactive (IG); n = 144 or active (AG); n = 94] based on self-reported exercise at baseline. Repeated measures ANCOVA, controlling for age, measured differences in physical function between activity groups at baseline and 48-months using the Timed Up and Go, 30-s chair stand, and 30-second arm curl. Differences in Timed Up and Go classification [normal (≤ 8.23 s); preclinical limitations/limited physical function (&gt;8.23 s)] were analyzed using chi-square tests for activity group and for activity-age group (AG, &lt;80 years; AG, ≥ 80 years; IG, &lt;80 years; IG, ≥ 80 years).

Results

The repeated measures ANCOVA yielded a significant main effect for activity group for the Timed Up and Go (p = 0.006), 30-s chair stand (p = 0.002) and 30 s arm curl (p = 0.007) and a significant time main effect for the Timed Up and Go (p = 0.016). There were no significant group by time interactions. A larger proportion of the IG than the AG (58.2 vs. 86.5%, respectively) had Timed Up and Go scores &gt;8.23 s (p &lt; 0.001). At 48-months, individuals in the AG were more likely to have normal Timed Up and Go scores compared to those in the IG in both age groups [χ(3, N=236)2 = 42.56, p &lt; 0.001].

Conclusion

Older women who engaged in regular exercise at baseline had higher levels of objectively measured physical function and were less likely to have abnormal Timed Up and Go scores. These findings help illustrate the long-term benefit of exercise on physical function in older women.

The role of socio-demographic factors and physical functioning in the intra- and interpersonal variability of older adults' sedentary time: an observational two-country study

BACKGROUND

Insight into the variability of older adults' sedentary time is needed to inform future interventions. The aim of this study was to examine the intra- and interpersonal variability in sedentary time, and the moderating role of socio-demographics, physical functioning and geographical location in this variability.

METHODS

Cross-sectional data from 818 community-dwelling older adults (mean age: 74.8 years; 61.1%women) of the Active Lifestyle and the Environment in Chinese Seniors and Belgian Environmental Physical Activity Study in Seniors were used. An interview questionnaire was administered to collect socio-demographic information. The Short Physical Performance Battery was performed to evaluate physical functioning, and Actigraph GT3X( +) accelerometers were used to estimate sedentary time. Linear mixed models with random intercepts at the neighborhood, person and day levels examined the variability in sedentary time, and the moderating role of socio-demographics, physical functioning and geographical location within this variability.

RESULTS

Most of the variance in accelerometry-assessed sedentary time was due to intrapersonal variability across periods of the day (72.4%) followed by interpersonal variability within neighborhoods (25.6%). Those who were older, men, lived in Hong Kong, and experienced a lower level of physical functioning were more sedentary than their counterparts. Sedentary time increased throughout the day, with highest levels of sedentary time observed between 6:00 and 9:00 pm. The patterns of sedentary time across times of the day differed by gender, educational attainment, age, physical functioning and/or geographical location. No significant differences were detected between week and weekend day sedentary time.

CONCLUSIONS

The oldest old, men, and those with functional limitations are important target groups for sedentary behavior interventions. As sedentary time was the highest in the evening future sedentary behavior intervention should pay particular attention to the evening hours. The variations in diurnal patterns of sedentary time between population subgroups suggest that personalized just-in-time adaptive interventions might be a promising strategy to reduce older adults' sedentary time.

Prevalence and determinants of physical frailty among people living in residential aged care facilities: a large-scale retrospective audit

Background

Physical frailty is associated with increased risk of falls, hospitalisation and mortality. There is a dearth of information on physical frailty of older adults living in residential aged care. This study aimed to describe physical frailty in aged care residents and investigate possible determinants of frailty.

Method

A retrospective audit of resident records was undertaken across 14 residential aged care facilities. Data were extracted on all consenting residents who had completed measures relating to frailty (Short Physical Performance Battery SPPB; grip strength). All data of the first record of measures were extracted, resident characteristics, and the time from admission to assessment. Summary statistics were completed. Differences between sub-groups were explored (Mann-Whitney U, Kruskall-Wallis Ranked tests). Associations between variables were explored with Chi-squared and Pearson correlations. Determinants of physical frailty were determined with linear regression analyses. Alpha (2-sided) was 0.05.

Results

Data were extracted for 1241 residents (67% female), with a mean age of 86.0 (7.6) years. Males had a significantly lower time from admission to assessment of frailty (p ≤ 0.001). The average SPPB score was 4.1 (3.3), 75% of residents were frail and 19% pre-frail. Bivariate analyses indicated no significant relationships between grip strength and SPPB score, but significant differences for grip strength, where males were significantly stronger (males 20.2 ± 8.3 kg; females 12.4 ± 5.4 kg; p ≤ 0.001). There was a significant positive relationship between SPPB total score and grip strength, gender (p ≤ 0.001), and marital status (p = 0.049) and a negative relationship between time from admission to assessment and SPPB total score (p ≤ 0.001). There were significant negative relationships between gender (p ≤ 0.001) and age (p ≤ 0.001), and time from admission to assessment (p ≤ 0.001) with grip strength.

Conclusion

Older adults living in residential aged care have a high level of physical frailty which may lead to increased risk of adverse outcomes. Time in the residential aged care setting and age appear to predict physical frailty. There is a need for a consistent battery of measures to continually monitor frailty and programs to address the high levels of frailty in residential aged care.