Validation of accelerometer wear and nonwear time classification algorithm

Cardiorespiratory Fitness and Sleep, but not Physical Activity, are Associated with Functional Connectivity in Older Adults

BACKGROUND

Aging results in changes in resting state functional connectivity within key networks associated with cognition. Cardiovascular function, physical activity, sleep, and body composition may influence these age-related changes in the brain. Better understanding these associations may help clarify mechanisms related to brain aging and guide interventional strategies to reduce these changes.

METHODS

In a large (n = 398) sample of healthy community dwelling older adults that were part of a larger interventional trial, we conducted cross sectional analyses of baseline data to examine the relationships between several modifiable behaviors and resting state functional connectivity within networks associated with cognition and emotional regulation. Additionally, maximal aerobic capacity, physical activity, quality of sleep, and body composition were assessed. Associations were explored both through correlation and best vs. worst group comparisons.

RESULTS

Greater cardiovascular fitness, but not larger quantity of daily physical activity, was associated with greater functional connectivity within the Default Mode (p = 0.008 r = 0.142) and Salience Networks (p = 0.005, r = 0.152). Better sleep (greater efficiency and fewer nighttime awakenings) was also associated with greater functional connectivity within multiple networks including the Default Mode, Executive Control, and Salience Networks. When the population was split into quartiles, the highest body fat group displayed higher functional connectivity in the Dorsal Attentional Network compared to the lowest body fat percentage (p = 0.011; 95% CI - 0.0172 to - 0.0023).

CONCLUSION

These findings confirm and expand on previous work indicating that, in older adults, higher levels of cardiovascular fitness and better sleep quality, but not greater quantity of physical activity, total sleep time, or lower body fat percentage are associated with increased functional connectivity within key resting state networks.

Momentary Associations Between Physical Activity, Affect, and Purpose in Life

BACKGROUND

Physical activity is associated with both the hedonic (e.g., affect) and eudaimonic (e.g., purpose in life) aspects of well-being. While there is evidence linking momentary physical activity and affect in daily life, the examination of momentary purpose remains largely unexplored.

PURPOSE

This study investigates the bidirectional associations between physical activity, positive and negative affect, and momentary purpose using Ecological Momentary Assessment (EMA) and accelerometer data.

METHODS

Middle-aged participants (40-70 years old, n = 291) wore accelerometers and completed three daily EMA surveys on momentary experiences for 8 consecutive days. Physical activity (active time and counts) from 20- to 60-min periods before and after EMA surveys were used in the analyses. Multilevel models were adjusted for temporal and contextual factors, age, sex, education, work status, and race/ethnicity.

RESULTS

When participants were more physically active than usual, they reported feeling more purpose-driven and positive affect. Similarly, when participants reported feeling more purpose-driven or experiencing positive affect, they engaged in more physical activity in the subsequent time period. These associations were similar for physical activity from 20- to 60-min periods before and after the EMA survey. Physical activity and negative affect were not related in either direction.

CONCLUSIONS

In middle-aged adults' daily lives, physical activity has bidirectional relations with purpose and positive affect. This study highlights the dynamic associations between physical activity and the positive aspects of both hedonic and eudaimonic well-being. Future interventions or public health programs should integrate physical activity and mental well-being to maximize mutual benefits.

Development of an accelerometer age- and sex-specific approach based on population-standardized values for physical activity surveillance: A proof of concept

BACKGROUND

A shift from self-reports to wearable sensors for global physical activity (PA) surveillance has been recommended. The conventional use of a generic cut-point to assess moderate-to-vigorous PA (MVPA) is problematic as these cut-points are often derived from non-representative samples under non-ecological laboratory conditions. This study aimed to develop age- and sex- (age-sex) specific cut-points for MVPA based on population-standardized values as a feasible approach to assess the adherence to PA guidelines and to investigate its associations with all-cause mortality.

METHODS

A total of 7601 participants (20-85+ years) were drawn from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Surveys (NHANES). Minutes per week of MVPA were assessed with a hip-worn accelerometer. Counts per minute (CPM) were used to define an age-sex specific target intensity, representing the intensity each person should be able to reach based on their age and sex. Age-sex specific MVPA cut-points were defined as any activity above 40% of the target intensity. These population- and free-living-based age-sex specific cut-points overcome many of the limitations of the standard generic cut-point approach. For comparison, we also calculated MVPA with a generic cut-point of 1952 CPM. Both approaches were compared for assessing adherence to PA guidelines and association of MVPA with all-cause mortality (ascertained through December 2015).

RESULTS

Both approaches indicated that 37% of the sample met the 150+ min/week guideline. The generic cut-point approach showed a trend to inactivity with age, which was less pronounced using the age-sex specific cut-points. Overall mortality rates were comparable using generic cut-point (hazard ratio (HR) = 0.61, 95% confidence interval (95%CI): 0.50‒0.73) or age-sex specific cut-points (HR = 0.57, 95%CI: 0.50‒0.66) for the entire sample. The generic cut-point method revealed an age- and sex-related gap in the benefits of achieving 150+ min/week of MVPA, with older adults showing an 18% greater reduction in mortality rates than younger adults, and a larger difference in women than in men. This disparity disappeared when using age-sex specific cut-points.

CONCLUSION

Our findings underscore the value of age-sex specific cut-points for global PA surveillance. MVPA defined with age-sex specific thresholds was associated with all-cause mortality and the dose‒response was similar for all ages and sexes. This aligns with the single recommendation of accumulating 150+ min/week MVPA for all adults, irrespective of age and sex. This study serves as a proof of concept to develop this methodology for PA surveillance over more advanced open-source acceleration metrics and other national and international cohorts.

Structured-unstructured activity behaviours on preschoolers' mental and physical health: a compositional and isotemporal reallocation analysis

This study analysed the relationship between the structured and unstructured activities of preschoolers and their mental and physical health, and also investigated the predicted changes in mental and physical health by reallocating activity time. This cross-sectional study was carried out with 324 preschoolers. Video recording and SOPARC activity observation system was used for the division of structured and unstructured activities. An accelerometer sensor was used to measure activity intensity. The SDQ psychological questionnaire was adopted to collect data on internalizing difficulties, externalizing difficulties, total difficulties and pro-social behaviours. Physical indices including body shape (height, weight, BMI), and physical fitness (upper and lower limb strength, flexibility, agility, and balance) were collected using Chinese toddler physical fitness measurement tools. Component data and isotemporal reallocation analyses were conducted using R Studio (Version 4.2). A total of 308 preschoolers (160 boys; aged 4.50 ± 0.93 years) were included in the data analysis. The activities composition, adjusted for sex, area, mental level (for mental indicators), or age (for physical indicators), was significantly correlated with various measurement indicators (p < 0.05). Specifically, structured (β=-0.87, p < 0.05) and unstructured (β=-1.24, p < 0.05) moderate-to-vigorous physical activity (MVPA) were significantly positive correlated with internalizing difficulties, while structured MVPA was significantly positively correlated with body shape (β = 2.17, p < 0.05). Replacing structured light physical activity (LPA) with 10 min of structured MVPA has a positive effect on internalizing difficulties (SMD=-1.28, 95%CI: -2.30 to -0.27) and body shape (SMD = 1.76, 95%CI: 0.37 to 3.15). When the total replacement time reaches 25 min, the benefits become even more pronounced. Structured and unstructured MVPA are both beneficial to preschoolers' mental and physical health, with the incorporation of MVPA for over 25 min in structured activities and supplementary unstructured MVPA yielding even greater benefits.

Scalar-on-function regression: Estimation and inference under complex survey designs

Increasingly, large, nationally representative health and behavioral surveys conducted under a multistage stratified sampling scheme collect high dimensional data with correlation structured along some domain (eg, wearable sensor data measured continuously and correlated over time, imaging data with spatiotemporal correlation) with the goal of associating these data with health outcomes. Analysis of this sort requires novel methodologic work at the intersection of survey statistics and functional data analysis. Here, we address this crucial gap in the literature by proposing an estimation and inferential framework for generalizable scalar-on-function regression models for data collected under a complex survey design. We propose to: (1) estimate functional regression coefficients using weighted score equations; and (2) perform inference using novel functional balanced repeated replication and survey-weighted bootstrap for multistage survey designs. This is the first frequentist study to discuss the estimation of scalar-on-function regression models in the context of complex survey studies and to assess the validity of various inferential techniques based on re-sampling methods via a comprehensive simulation study. We implement our methods to predict mortality using diurnal activity profiles measured via wearable accelerometers using the National Health and Nutrition Examination Survey 2003-2006 data. The proposed computationally efficient methods are implemented in R software package surveySoFR.

Reallocation of time to moderate-to-vigorous physical activity and estimated changes in physical fitness among preschoolers: a compositional data analysis

BACKGROUND

Previous research has examined the associations of preschoolers' 24-h movement behaviours, including light and moderate-to-vigorous physical activity (LPA and MVPA), sedentary behaviour (SB), sleep, with physical fitness in isolation, ignoring intrinsically compositional nature of movement data while increasing the risk of collinearity. Thus, this study investigated the associations of preschoolers' 24-h Movement behaviours composition with physical fitness, estimated changes in physical fitness when time was reallocated between movement behaviours composition, and determined whether associations differ between different genders, using compositional data analysis.

METHODS

In the cross-sectional study, a total of 275 preschoolers (3 ~ 6 y) from China were included. SB, LPA and MVPA times were objectively monitored with an ActiGraph GT9X accelerometer for 7 consecutive days. Sleep duration was obtained using parental reports. Physical fitness parameters, including upper and lower limb strength, static balance, speed-agility, and cardiorespiratory fitness (CRF), were determined with the PREFIT battery. The associations of 24-h movement behaviours composition with each physical fitness parameter were examined employing compositional multivariable linear regression models. The changes following time reallocation among behaviours were estimated employing compositional isotemporal substitution analyses.

RESULTS

Greater MVPA, but not LPA, was significantly related to better upper and lower limb strength, speed-agility, and CRF. Reallocating time from LPA or SB to MVPA was related to better physical fitness. The associations were non-symmetrical: the estimated detriments to physical fitness from replacing MVPA with LPA or SB were larger than the estimated benefits associated with adding MVPA of the same magnitude. The aforementioned associations with lower limb strength, CRF, and speed-agility were observed in boys, while associations with upper and lower limb strength were noted in girls.

CONCLUSION

Our findings reinforce the importance of physical activity (PA) intensity for the development of physical fitness in preschoolers. Replacing LPA or SB time with MVPA may be an appropriate strategy for enhancing preschoolers' physical fitness.

Association Between Physical Activity, Sedentary Behaviors, and Sleep-Related Outcomes Among Cancer Survivors: a Cross-Sectional Study

BACKGROUND

Limited research has examined the association between moderate to vigorous physical activity (MVPA), sedentary behavior (SB), and sleep-related outcomes in cancer survivors. Therefore, this study aimed to examine these associations using a nationally representative sample of US adults.

METHODS

Data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) were analyzed. A total of 3229 adults with cancer histories were included. Physical activity was measured through accelerometry, and questions on daily activities, sedentary time, and sleep were collected during the household interview. Weighted multivariable analyses were conducted after accounting for the complex sampling design of the NHANES dataset.

RESULTS

After adjustments, physical activity and SB outcomes were associated with several self-reported sleep-related parameters. Increases in minutes of self-reported MVPA and SB were associated with a decreased likelihood of reporting ≥ 8 h of sleep (OR = 0.92, 95% CI = 0.86, 0.99 and OR = 0.88, 95% CI = 0.82, 0.95). Converse associations were found between device-measured MVPA and SB with the likelihood of reporting often/always feeling overly sleepy during the day (OR = 0.86, 95% CI = 0.75 and OR = 1.13, 95% CI = 1.05, respectively). However, an increased likelihood of waking up too early in the morning (OR = 1.22, 95% CI = 1.04) was observed with increases in minutes of device-measured MVPA.

CONCLUSIONS

A sensible strategy to decrease the frequency of sedentary breaks and increase minutes of physical activity throughout the day may reduce sleep complaints reported in cancer survivors.

Concurrent validity of the Global Physical Activity Questionnaire to accelerometry in Hispanic/Latino adults: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

OBJECTIVES

The validity of the Global Physical Activity Questionnaire has not been thoroughly evaluated among Hispanics/Latinos. In this cross-sectional study, we assessed the concurrent validity and correlates of discordance of the Global Physical Activity Questionnaire by comparing it to accelerometry in estimating sedentary behavior, moderate-to-vigorous physical activity, and meeting United States physical activity guidelines by sociodemographic, behavioral, and health characteristics.

DESIGN

The Hispanic Community Health Study/Study of Latinos is a 4-site cohort study of United States adults aged 18-74 years enrolled from 2008 to 2011.

METHODS

Participants (n = 11,873) completed the Global Physical Activity Questionnaire and wore an accelerometer for 1 week. Lin's concordance and Pearson correlations assessed concurrent validity between self-reported and accelerometry-assessed measures of sedentary behavior and moderate-to-vigorous physical activity. Kappa coefficients assessed agreement of meeting physical activity guidelines. Linear and logistic regression models identified correlates of discordance.

RESULTS

The overall Lin's concordance and Pearson correlations between the Global Physical Activity Questionnaire and accelerometry estimates were 0.10 (95 % confidence interval 0.09, 0.12) and 0.24 (0.21, 0.27) for sedentary behavior, and 0.04 (0.03, 0.05) and 0.18 (0.15, 0.22) for moderate-to-vigorous physical activity, respectively. Agreement was poor for meeting the physical activity guideline classifications (Kappa coefficients: 0.12 to 0.26). Over a 16-hour day, sedentary behavior was under-reported by 3.8 h and moderate-to-vigorous physical activity was over-reported by 1.9 h.

CONCLUSIONS

The concurrent validity of the Global Physical Activity Questionnaire in measuring moderate-to-vigorous physical activity and sedentary behavior when compared to accelerometry was poor among Hispanic/Latino adults.

Investigating the relationship between physical activity and self-reported outcomes in adults with rotator cuff related shoulder pain

PURPOSE

Rotator cuff related shoulder pain is common among older adults. While exercise is often recommended for this condition, the relationship between physical activity levels and self-reported outcomes is unclear. This study investigated whether self-reported outcomes (pain, function, depressive symptoms, self-efficacy, general mental and physical health) relate to physical activity, and whether those who participated in shoulder-specific exercise had better self-reported outcomes than those who performed whole-body exercise.

METHODS

Forty-six participants with rotator cuff related shoulder pain participated from which 35 had complete datasets. Questionnaires were used to assess physical activity, pain, physical function, general health, and self-efficacy. Physical activity levels were also measured using an accelerometer.

RESULTS

Neither pain nor other self-reported outcomes were related to subjective or objective physical activity levels. Participants that completed shoulder-specific exercise had significantly higher exercise self-efficacy than those who completed nonspecific exercise (P = .01; d = 0.91).

CONCLUSION

A significant relationship between pain or self-reported outcomes and physical activity was not identified. Those who self-reported regularly exercising their injured shoulder had higher exercise self-efficacy than those who did not. These findings have clinical implications, suggesting that strategies to boost exercise self-efficacy may be important for older adults with rotator cuff related shoulder pain.

Understanding Breathlessness Burden and Psychophysiological Correlates in Asthma

BACKGROUND

Breathlessness is a disabling symptom, with complexity that is often under-recognized and undertreated in asthma.

OBJECTIVE

To highlight the burden of breathlessness in people with severe compared with mild-to-moderate asthma and identify psychophysiological correlates of breathlessness.

METHODS

This was a cross-sectional study of people with mild-to-severe asthma, who attended 2 in-person visits to complete a multidimensional assessment. The proportion of people with mild-to-moderate versus severe asthma who reported physically limiting breathlessness (modified Medical Research Council [mMRC] dyspnea score ≥2) was compared. Psychophysiological factors associated with breathlessness in people with asthma were identified via a directed acyclic graph and explored with multivariate logistic regression to predict breathlessness.

RESULTS

A total of 144 participants were included, of whom, 74 (51%) had mild-to-moderate asthma and 70 (49%) severe asthma. Participants were predominantly female (n = 103, 72%) with a median (quartile 1, quartile 3) age of 63.4 (50.5, 69.5) years and body mass index (BMI) of 31.3 (26.2, 36.0) kg/m2. The proportion of people reporting mMRC ≥2 was significantly higher in those with severe- (n = 37, 53%) than those with mild-to-moderate (n = 21, 31%) asthma (P = .013). Dyspnoea-12 Total (8.00 [4.75, 17.00] vs 5.00 [2.00, 11.00], P = .037) score was also significantly higher in the severe asthma group. Significant predictors of physically limiting breathlessness were BMI, asthma control, exercise capacity, and hyperventilation symptoms. Airflow limitation and type 2 inflammation were poor breathlessness predictors.

CONCLUSIONS

Over half of people with severe asthma experience physically limiting breathlessness despite treatment. Targeting psychophysiological factors, or traits, associated with breathlessness may help relieve this distressing symptom, which is of high priority to people with asthma.

Physical Activity, Sedentary Behavior, and Their Predictors Among Nursing Home Residents-Cross-Sectional Results of the BaSAlt Study

Little is known about physical activity (PA) and sedentary behavior (SB) among nursing home residents although PA is known as a health promoter. This study examined PA, SB, and their predictors among nursing home residents (n = 63). Dependent variables were accelerometry-based PA and SB. Predictor variables included in a path analysis were age, sex, body mass index, Barthel Index, cognitive status (Mini-Mental State Examination), physical performance (hand grip strength and habitual walking speed), and well-being (World Health Organization-5 well-being index). PA was very low (M steps per day = 2,433) and SB was high (M percentage of sedentary time = 89.4%). PA was significantly predicted by age (β = -0.27, p = .008), body mass index (β = -0.29, p = .002), Barthel Index (β = 0.24, p = .040), and hand grip strength (β = 0.30, p = .048). SB was significantly predicted by body mass index (β = 0.27, p = .008) and Barthel Index (β = -0.30, p = .012). Results might be helpful for everyday practice to identify individuals at high risk for low PA and high SB.

Sleep and health improvement programme (SHIP) for patients with prostate cancer and caregivers

Objective

The objective of this study is to determine whether a sleep and health improvement programme (SHIP) to promote healthy sleep, eating and physical activity would be feasible, acceptable and have a positive impact on lifestyle behaviours for prostate cancer survivors and caregivers.

Methods

We recruited 50 participants for a single group 3-month pre-post pilot study. The SHIP intervention included (1) website about sleep, nutrition and physical activity (≥1 view/week), (2) two email newsletters with goal-setting exercises and resources and (3) midpoint health coach call. The primary outcome was changes in validated sleep scales; secondary outcomes included changes in diet, physical activity and concentration from baseline to 3 months.

Results

Of 50 participants enrolled, median age was 65, 30% were Black and 8% were Hispanic. Thirty-four patients and 7 family caregivers completed the pilot study (82%). Following the intervention, we observed a statistically significant improvement in the Sleep Hygiene Index (pre: 15, post: 13, p < 0.01), and a trend toward lower Insomnia Severity Index (pre: 12, post: 9, p = 0.07). There were no statistically significant improvements in sleep quality or physical activity, but there were improvements in healthy eating (e.g., increase in cruciferous vegetables and reduction in dairy) and in fatigue-related problems and concentration. Exit interview feedback was positive.

Conclusions

A web-based sleep and healthy lifestyle programme for patients with prostate cancer and their caregivers is feasible and acceptable. A randomized controlled trial is planned to test whether a refined SHIP improves sleep and lifestyle in patients with prostate cancer and caregivers.

Influence of unilateral versus bilateral patellofemoral pain on physical activity, pain self-efficacy, and disability

BACKGROUND

Patellofemoral pain (PFP) affects physical and psychosocial health; however, it is unclear if unilateral and bilateral PFP induce similar levels of impairments.

OBJECTIVES

We aimed to compare physical activity (PA), pain self-efficacy, and disability between individuals with unilateral and bilateral PFP, and to compare these groups against pain-free controls.

DESIGN

Cross-sectional case-control.

METHOD

Sixty-two individuals with PFP (25 unilateral and 37 bilateral) and 20 pain-free controls completed the PA assessment using an accelerometer by daily steps, light PA, and moderate-to-vigorous PA (MVPA). We also calculated variability in each PA variable. Pain self-efficacy and disability were measured using the Pain Self-Efficacy Questionnaire and Anterior Knee Pain Scale, respectively.

RESULTS

Individuals with bilateral PFP took fewer daily steps compared to pain-free controls (9568.1 ± 3827.0 vs. 12,285.8 ± 2821.2 steps/day; P = 0.018, Cohen d = 0.79), whereas individuals with unilateral PFP did not (11,099.2 ± 3547.1 steps/day; P = 0.503, Cohen d = 0.37). Individuals with bilateral PFP showed greater variability in MVPA compared to individuals with unilateral PFP (42.9 ± 23.1 vs. 29.0 ± 15.9; P = 0.011, Cohen d = 0.91) and pain-free controls (42.9 ± 23.1 vs. 17.6 ± 6.1; P < 0.001, Cohen d = 1.21). Individuals with unilateral and bilateral PFP similarly exhibited less time spent in MVPA, greater variability in daily steps, lower pain self-efficacy, and greater disability compared to pain-free controls (P < 0.001, Cohen d = 1.14-3.89).

CONCLUSIONS

Versus pain-free controls, individuals with bilateral PFP displayed greater variability in MVPA than individuals with unilateral PFP. However, it is important to note that unilateral PFP influenced time spent in MVPA, variability in daily steps, pain self-efficacy, and disability at similar levels to bilateral PFP.

Perceived social support on objective measured sedentary behavior of stroke patients: the mediating role of exercise self-efficacy

Introduction

As stroke patients may have impaired motor function, there may have increased sedentary behavior. Factors associated with sedentary behavior need to be explored to develop targeted interventions. Although studies explore the effects of exercise self-efficacy and perceived social support on sedentary behavior, the relationship is not clear. The aim of this study was to explore the mediating effect of exercise self-efficacy on perceived social support and objective measured sedentary behavior in stroke patients.

Methods

The random sampling method was adopted to select 275 stroke patients from the neurology department of a third-grade hospital of Henan Province from June 2023 to March 2024 in a cross-sectional descriptive study. A general data questionnaire, exercise self-efficacy scale, perceived social support scale, and ActiGraph GT3X accelerometer were used to investigate. The structural equation model was used to analyze the mediating effect of exercise self-efficacy between perceived social support and sedentary behavior.

Results

The mean sedentary behavior time in stroke patients in this study was (479.65 ± 112.65) min, the mean score of perceived social support was (47.53 ± 17.16), and the mean score of exercise self-efficacy was (24.19 ± 6.25). The correlation analysis revealed that, the sedentary behavior of stroke patients was negatively correlated with exercise self-efficacy and perceived social support. The results of the mediation analysis showed that exercise self-efficacy played a partial mediating role between perceived social support and sedentary behavior.

Conclusion

Perceived social support and exercise self-efficacy were influential factors in sedentary behavior. Moreover, the impact of perceived social support on sedentary behavior was partially mediated by exercise self-efficacy. Therefore, to decrease the sedentary behavior, it is crucial to improve the level of perceived social support in stroke patients. Patients with less perceived social support can improve their exercise self-efficacy and thus perceive more social support.

Quantifying Physical Activity and Sedentary Behavior in Adults with Intellectual Disability: A Scoping Review of Assessment Methodologies

Background/Objectives: Methodologies for assessing behavior form the foundation of health promotion and disease prevention. Physical activity (PA) and sedentary behavior (SB) assessment methodologies have predominantly been developed for adults without an intellectual disability (ID), raising credibility concerns for adults with ID. The purpose was to synthesize the current state of assessment methodologies for quantifying PA and SB volume in the free-living setting for adults with an ID. Methods: Following PRISMA guidelines, eleven databases were searched through December 2023, yielding 8174 records. Data were extracted in Covidence (v.2.0), obtaining quantified PA and SB volume and assessment methodology characteristics across data collection and analysis, including tool(s) and technique(s) used, preparatory actions taken, instructions provided, and behavioral strategies employed during data collection. Results: Of the 8174 articles screened, 91 met the inclusion criteria. Common metrics included minutes/hours per day/week and steps per day/week. Despite 80% of the studies using objective techniques, substantial variation existed across studies regarding wearable models, sampling frequency and epoch length settings, calibration protocols, wearable placements, and data processing techniques. Limited studies provided instructions that did not exclusively rely on spoken language. Behavioral strategies varied, including self-monitoring, providing assistance or supervision, administering questionnaires verbally, issuing reminders, and offering monetary incentives. Conclusions: This review underscores the need for greater consistency and accessibility in PA and SB assessment methodology for adults with ID. Tailored preparation, instruction, and behavioral strategies may enhance assessment viability and suitability for adults with ID, with or without caregiver or researcher involvement in the free-living setting.

Plasma markers of neurodegeneration, latent cognitive abilities and physical activity in healthy aging

Blood-based biomarkers of neurodegeneration demonstrate great promise for the diagnosis and prognosis of Alzheimer's disease. Ultra-sensitive plasma assays now allow for quantification of the lower concentrations in cognitively unimpaired older adults, making it possible to investigate whether these markers can provide insight also into the early neurodegenerative processes that affect cognitive function and whether the markers are influenced by modifiable risk factors. Adopting an exploratory approach in 93 healthy older adults (65-75 years), we used structural equation modelling to investigate cross-sectional associations between multiple latent cognitive abilities (working memory, episodic memory, spatial and verbal reasoning) and plasma amyloid beta (Aβ42/Aβ40 ratio), phosphorylated-tau 181 (ptau-181), glial fibrillary acidic protein (GFAP), and neurofilament light (NfL), as well as the influence of device-measured habitual physical activity on these associations. The results showed that NfL was negatively associated with working memory, and that NfL interacted with moderate-to-vigorous physical activity in its association with episodic memory. The study has thereby demonstrated the potential of neurodegenerative plasma markers for improving understanding of normative cognitive aging and encourages future research to test the hypothesis that high levels of NfL, indicative of white matter pathology, limit the beneficial effect of physical activity on episodic memory in healthy aging.

Do Children's Health Behaviors Buffer the Impact of Cumulative Environmental Stress on Emerging Cardiometabolic Risk?

BACKGROUND

Previous studies have found that exposure to childhood environmental stress is associated with cardiometabolic risk. However, it is not known whether individual health behaviors disrupt this relationship. This study prospectively evaluated the relationship between cumulative environmental stress in a low-income sample and cardiometabolic risk in middle childhood and examined whether child health behaviors attenuated this relationship.

METHODS AND RESULTS

In a cohort of children (n=338; 57% Hispanic children; 25% Black children), environmental stressors (family and neighborhood factors representing disadvantage/deprivation) and child health behaviors (accelerometry measured physical activity; parent-reported screen time and diet recalls) were measured over 5 time points beginning when children were aged 2 to 4 years and ending when they were aged 7 to 11 years. Children's cardiometabolic risk factors (body mass index, blood pressure, triglyceride/high-density lipoprotein ratio, glucose, hemoglobin A1c, C-reactive protein) were measured at 7 to 11 years. Emerging cardiometabolic risk was defined as having ≥1 elevations that exceeded clinical thresholds. In adjusted path analyses, greater cumulative environmental stress was associated with higher likelihood of emerging cardiometabolic risk in middle childhood (P<0.001). Higher levels of moderate to vigorous physical activity and fewer sedentary minutes attenuated the positive relationship between stress and cardiometabolic risk (P<0.05). Children with >2 hours of average daily screen time had a higher likelihood of elevated cardiometabolic risk (P<0.01), but screen time did not moderate the stress-cardiometabolic risk relationship. Dietary intake was not related to cardiometabolic risk.

CONCLUSIONS

Interventions that promote moderate to vigorous physical activity and limit sedentary behavior may have particular importance for the cardiometabolic health of children exposed to high levels of cumulative environmental stress.

Testing home-based exercise strategies in underserved minority cancer patients undergoing chemotherapy (THRIVE) trial: a study protocol

Background

Higher rates of physical inactivity and comorbid conditions are reported in Hispanic/Latinx and Black cancer patients receiving chemotherapy compared to their White counterparts. Despite the beneficial effect of exercise training for cancer patients, rates of participation in exercise oncology clinical trials are low among disadvantaged and racial and ethnic minority groups. Here, we will examine the effect of an exercise intervention using a novel, accessible, and cost-effective home-based exercise approach among Hispanic/Latinx and Black cancer patients receiving chemotherapy on exercise participation and cardiovascular disease risk.

Methods

The THRIVE trial is an 8-month prospective, three-arm study of 45 patients who are randomized in a 1:1:1 fashion to a supervised exercise intervention (SUP), unsupervised exercise (UNSUP), or an attention control (AC) group. Eligible patients include those with breast, colorectal, or prostate cancer, who are sedentary, overweight or obese, self-identify as Hispanic/Latinx or Black, and plan to receive chemotherapy. Patients randomized to the SUP group participate in a home-based 16-week periodized aerobic and resistance exercise program performed three days per week, supervised through video conference technology. Patients randomized to the UNSUP group participate in an unsupervised 16-week, telehealth-based, periodized aerobic and resistance exercise program performed three days per week using the same exercise prescription parameters as the SUP group. Patients randomized to the AC group receive a 16-week home-based stretching program. The primary outcome is changes in minutes of physical activity assessed by 7-day accelerometry at post-intervention. Secondary outcomes include cardiovascular risk factors, patient-reported outcomes, and physical function. Outcome measures are tested at baseline, post-intervention at month 4, and after a non-intervention follow-up period at month 8.

Discussion

The THRIVE trial is the first study to employ a novel and potentially achievable exercise intervention for a minority population receiving chemotherapy. In addition, this study utilizes an intervention approach to investigate the biological and behavioral mechanisms underlying exercise participation in these cancer patients. Results will guide and inform large randomized controlled trials to test the effect of home-based exercise on treatment outcomes and comorbid disease risk in minority patients with cancer undergoing chemotherapy.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/NCT05327452, identifier (NCT#05327452).

Adherence to the WHO physical activity, screen time and sleep guidelines and associations with socio-demographic factors among Ethiopian preschool children: The SUNRISE study

BACKGROUND

The World Health Organisation (WHO) has called for more evidence on 24-hour movement behaviours from low- and middle-income countries. We examined the proportion of Ethiopian children aged 3.0-4.9 years who met the WHO guidelines on physical activity, screen time and sleep for children under the age of five, and the associations between meeting the guidelines and socio-demographic factors.

METHODS

A cross-sectional study was conducted in Adama and Lume district, Ethiopia. Children were recruited through kindergartens in Adama city and rural villages of Lume district, Ethiopia. Physical activity and sleep were measured using ActiGraph accelerometer. Screen time and restrained sitting were parent-reported. Multivariable logistic regression models tested associations between meeting the individual and combined WHO guidelines and socio-demographic factors.

RESULTS

A total of 430 children participated in the study (mean age 4.2 ± 0.6 years). More than half the children (58.0%) met all the WHO guidelines. A higher proportion met the physical activity (96.1%) and sleep guidelines (91.9%) compared to the screen time guideline (63.5%). Children who lived in rural areas were more likely to meet the screen time (84.6% vs. 38.2%, AOR = 7.31; 95%CI: 3.93, 14.02), sleep (98.6% vs. 83.8%, AOR = 8.60; 95%CI: 3.55, 23.73) and combined (81.3% vs. 30.1%, AOR = 7.41; 95%CI: 4.04, 13.97) guidelines than those who lived in urban areas.

CONCLUSIONS

Children from rural Ethiopia were more compliant with the WHO guidelines than their urban counterparts. Strategies to reduce screen time and promote healthy movement behaviours in urban areas are needed. Further studies with a larger representative sample might provide better insight across the regions within the country.

A comparison of the physical activity levels of 3-to-6-year-old children with autism spectrum disorder and children with typical development

Background

Physical activity during early development is closely related to health. Differences in physical activity between young children with autism spectrum disorder and those with typical development are unclear. The purpose of this study was to compare the physical activity levels in children with autism spectrum disorder and typically developing children from the same area, including their sedentary physical activity, light physical activity, moderate-to-vigorous physical activity, and number of days in which the moderate-to-vigorous physical activity guideline recommendation of 60 min per day was met.

Methods

A total of 77 participants aged 3-6 years were included: 41 children with autism spectrum disorder (mean age = 61.41 ± 10.69 months) and 36 children with typical development (mean age = 60.36 ± 10.16 months). The physical activity of the children was measured using an ActiGraph GT3x accelerometer.

Results

There were no significant differences in daily sedentary physical activity (439.70 ± 54.98 vs. 450.42 ± 53.67) or moderate-to-vigorous physical activity (46.62 ± 18.93 vs. 47.47 ± 18.26) between the two groups. The average daily moderate-to-vigorous physical activity of the two groups did not reach 60 min, and they had similar proportions of participants who reached 60 min a given number of times (24.4% vs. 25%). Daily light physical activity was significantly higher in the autism spectrum disorder group (263.96 ± 43.17 vs. 242.32 ± 37.91, p < 0.05). The moderate-to-vigorous physical activity of both groups was similar and lower than the recommended minimum physical activity.

Conclusion

Targeted interventions should be considered in early intervention programs for children with autism spectrum disorder to increase their moderate-to-vigorous physical activity.

Association of physical symptoms with accelerometer-measured movement behaviors and functional capacity in individuals with Long COVID

Long COVID has been linked to a decline in physical activity and functional capacity. However, it remains unclear which physical symptoms are associated with specific aspects of movement behaviors and functional capacity. We aimed to investigate the associations of fatigue, dyspnea, post-exertional malaise, myalgia, and the co-occurrence of symptoms with movement behaviors and functional capacity in individuals with Long COVID. A cross-sectional multicenter study was conducted. Questionnaires were used to assess fatigue, dyspnea, post-exertional malaise, and myalgia. Accelerometry was employed to assess sedentary time, steps per day, light physical activity, and moderate-to-vigorous physical activity. The six-minute walk test, 30-s chair stand test, and timed up and go were used to assess functional capacity. One hundred and two community-dwelling individuals who had been living with Long COVID for 15 ± 10 months participated in the study. Fatigue, post-exertional malaise, and the co-occurrence of physical symptoms showed a negative association with step count, while post-exertional malaise was also negatively associated with moderate-to-vigorous physical activity. Dyspnea showed a negative association with the functional score, including all tests. Our findings suggest that fatigue, post-exertional malaise, and the co-occurrence of physical symptoms are negatively associated with physical activity, while dyspnea is negatively associated with functional capacity in individuals with Long COVID.

Sex differences in the role of sleep on cognition in older adults

Study Objectives

The study aimed to investigate sex differences in the relationship between sleep quality (self-report and objective) and cognitive function across three domains (executive function, verbal memory, and attention) in older adults.

Methods

We analyzed cross-sectional data from 207 participants with normal cognition (NC) or mild cognitive impairment (89 males and 118 females) aged over 60 years. The relationship between sleep quality and cognitive performance was estimated using generalized additive models. Objective sleep was measured with the GT9X Link ActiGraph, and self-reported sleep was measured with the Pittsburgh Sleep Quality Index.

Results

We found that females exhibited lower executive function with increased objective total sleep time, with a steeper decline in performance after 400 minutes (p = .015). Additionally, longer objective sleep correlated with lower verbal memory linearly (p = .046). In males, a positive linear relationship emerged between objective sleep efficiency and executive function (p = .036). Self-reported sleep was not associated with cognitive performance in females and males with NC. However, in males with cognitive impairment, there was a nonlinear positive relationship between self-reported sleep and executive function (p < .001).

Conclusions

Our findings suggest that the association between sleep parameters on cognition varies between older males and females, with executive function being most strongly associated with objective sleep for both sexes top of form. Interventions targeting sleep quality to mitigate cognitive decline in older adults may need to be tailored according to sex, with distinct approaches for males and females.

Prior-Night Sleep Predicts Next-Day Sedentary Behavior as a Function of Work Duration in Public Safety Telecommunicators

Public safety telecommunicators are at significant risk for obesity and other health conditions, which can likely be attributed to high-intensity job functions that occur in seated positions for long work hours. However, the interactions between these variables, as well as the role of recovery sleep, remains underexplored. We hypothesized that work duration would moderate the daily relationship between prior-night sleep and next day sedentary behavior. To test this hypothesis, actigraphic estimates of sleep and activity were gathered in 47 public safety telecommunicators over an average of 11 days (n = 525 cases). Results indicated that participants spent more time sedentary when they had less efficient, prior-night sleep in combination with both longer shifts or longer-than-usual same-day shifts. Wake time after sleep onset and total sleep time were positively associated with more next-day sedentary behavior, but only when working fewer hours. These findings suggest that public safety telecommunicators engage in compensatory, behavioral sleep patterns that are consistent with chronic insomnia and affected by both cumulative and daily work duration. Taken together, these results provide strong proof-of-concept that sleep health promotion and insomnia intervention might decrease sedentary behavior.

Associations of steps per day and step intensity with the risk of cancer: Findings from the Women's Health Accelerometry Collaboration cohort

OBJECTIVE

Accumulating more steps/day is associated with a lower risk of cancer mortality and composite cancer outcomes. However, less is known about the relationship of steps/day with the risk of multiple site-specific cancers.

METHODS

This study included >22,000 women from the Women's Health Accelerometry Collaboration Cohort (2011-2022), comprised of women from the Women's Health Study and Women's Health Initiative Objective Physical Activity and Cardiovascular Health Study. Steps/day and step intensity were collected with accelerometry. Incident cancer cases and deaths were adjudicated. Stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of the associations of steps/day and step intensity with incident breast, colon, endometrial, lung, and ovarian cancers, a composite of 13 physical activity-related cancers, total invasive cancer, and fatal cancer.

RESULTS

On average, women were 73.4 years old, accumulated 4993 steps/day, and had 7.9 years of follow-up. There were small nonsignificant inverse associations with the risks of colon cancer (HR = 0.94, 95% CI: 0.83, 1.05), endometrial cancer (HR = 0.91, 95% CI: 0.82, 1.01), and fatal cancer (HR = 0.95 95% CI: 0.90, 1.00) per 1000 steps/day. More minutes at ≥40 steps/min and a faster peak 10- and 30-min step cadence were associated with a lower risk of endometrial cancer, but findings were attenuated after adjustment for body mass index and steps/day.

CONCLUSIONS

Among women 62-97 years, there were small nonsignificant inverse associations of colon, endometrial, and fatal cancer with more steps/day. Epidemiologic studies with longer follow-up and updated assessments are needed to further explore these associations.

Can step count be used to identify older adults with high sedentary time and low moderate-to-vigorous physical activity?

INTRODUCTION

Combined high sedentary time (ST) and low moderate-to-vigorous physical activity (MVPA) has been associated with adverse cardiovascular events. However, accurately assessing ST and MVPA in older adults is challenging in clinical practice.

PURPOSE

To investigate whether step count can identify older adults with unhealthier movement behavior (high ST/low MVPA) and poorer cardiometabolic profile.

METHODS

Cross-sectional study (n = 258; 66 ± 5 years). Step count, ST, and MVPA were assessed by hip accelerometry during 7 days. The cardiometabolic profile was assessed using a continuous metabolic syndrome score (cMetS), including blood pressure, HDL-cholesterol, triglycerides, fasting glucose, and waist circumference. Receiving operating curve analysis was used to test the performance of step count in identifying older adults with unhealthier movement behavior (highest tertile of ST/lowest tertile of MVPA). Healthier movement behavior was defined as lowest tertile of ST/highest tertile of MVPA, with neutral representing the remaining combinations of ST/MVPA.

RESULTS

A total of 40 participants (15.5%) were identified with unhealthier movement behavior (ST ≥ 11.4 h/day and MVPA ≤ 10 min/day). They spent ~73% and 0.4% of waking hours in ST and MVPA, respectively. Step count identified those with unhealthier movement behavior (area under the curve 0.892, 0.850-0.934; cutoff: ≤5263 steps/day; sensitivity/specificity: 83%/81%). This group showed a higher cMetS compared with neutral (β = .25, p = .028) and healthier movement behavior groups (β = .41, p = .008).

CONCLUSION

Daily step count appears to be a practical, simple metric for identifying community-dwelling older adults with concomitant high ST and low MVPA, indicative of unhealthier movement behavior, who have a poorer cardiometabolic profile.

Modernizing behavioral parent training program for ADHD with mHealth strategies, telehealth groups, and health behavior curriculum: a randomized pilot trial

OBJECTIVE

Parent behavior management training (BMT) is an evidence-based yet underutilized tool to treat children with ADHD and address related health disparities. This pilot study investigated the acceptability and feasibility of a novel, health behavior-, and technology-adapted BMT (LEAP) vs. standard BMT.

METHODS

The weekly 9-session LEAP telemedicine group program is based on a standard BMT curriculum enhanced with strategies for supporting optimal child sleep, problematic media use (PMU), and physical activity, including wrist-worn activity trackers. Children ages 6-10 years with ADHD and their caregivers were randomized to LEAP or standard BMT. Acceptability and feasibility were tracked. Caregivers completed standardized measures, and children wore hip-worn accelerometers for 1 week at baseline, postintervention (10 weeks), and follow-up (20 weeks).

RESULTS

84 parent/child dyads were randomized to LEAP or standard BMT, with high and comparable acceptability and feasibility. Both treatment groups demonstrated decreased ADHD symptoms and improved executive functions postintervention (p < .0001), maintained at follow-up. Average accelerometer-measured MVPA decreased and sleep duration remained unchanged, while PMU and bedtime resistance improved for both groups.

CONCLUSIONS

LEAP is highly feasible and acceptable, and yielded similar initial clinical and health behavior improvements to standard BMT. Innovative and targeted supports are needed to promote healthy behaviors in children with ADHD.

Compliance with the 24-hour movement behavior guidelines and the impact of sleep methods among toddler, preschool, and school-aged children enrolled in the Guelph Family Health Study

Canadian movement guidelines focused on physical activity (PA), sleep, and screen time support childhood development and reduce the risk of chronic disease. Accelerometers are often used to capture these behaviors; however, they are limited in their ability to record daytime sleep due to potential misclassification.

OBJECTIVES

The objectives of this study were to 1) determine the prevalence of children enrolled in the Guelph Family Health Study who met the guidelines and to 2) compare the impact of different sleep measurement methods.

DESIGN/METHODS

Toddlers (1.5-<3 years; n = 128; valid data for all movement behaviors, n = 70), preschoolers (3-<5 years; n = 143; valid data for all movement behaviors, n = 104), and school-aged (5-<6 years; n = 49; valid data for all movement behaviors, n = 31) children were included. Screen time and sleep habits were obtained through parental report and published normative data. PA and sleep were recorded using accelerometers (wGT3X-BT ActiGraph; right hip).

RESULTS

It was found that 66 % of toddler, 44 % of preschool, and 63 % of school-aged children met the screen time guidelines. Further, 63 % of toddler, 98 % of preschooler, and 80 % of school-aged children met PA guidelines. Sleep guideline compliance ranged from 3 % to 83 % in toddler, 27 % to 92 % in preschooler, and 32 % to 90 % in school-aged children. These proportions were found to be significantly different (Cochran's Q and McNemar's tests).

CONCLUSIONS

Nearly all children met PA guidelines. In contrast, less than half to two-thirds met screen time guidelines. Compliance with sleep guidelines varied substantially with measurement method, highlighting the need for standardization.

Association of 24-Hour movement behavior and cognitive function in older Taiwanese adults

OBJECTIVES

This study investigates how 24-hour movement behaviors (physical activity, sedentary time, sleep) relate to cognitive performance in older adults.

METHODS

213 adults (aged 65+) wore accelerometers to track activity. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Isotemporal substitution analysis examined how replacing one behavior with another affected cognition.

RESULTS

Increased light physical activity was linked to better cognitive function, whereas longer sleep had a negative impact. Replacing 30 min of sedentary behavior or sleep with light physical activity improved orientation, attention, language, and short-term memory. Substituting moderate-to-vigorous physical activity did not have the same cognitive benefit.

CONCLUSION

Encouraging older adults to replace sedentary time or excess sleep with light physical activity could support cognitive health and potentially help prevent dementia. These findings have implications for public health strategies promoting cognitive well-being in aging populations.

Processing of Sedentary Time and Its Reference Equation in Patients with COPD

Purpose

Sedentary time (ST) is associated with mortality independent of moderate-to-vigorous physical activity in patients with COPD. The proper processing methods for the measurement data and factors related to ST are still unknown. We investigated several conditions for determining the proper processing of ST accelerometric data and created a reference equation for ST using ST-related factors.

Patients and Methods

In Study 1, we evaluated the minimum required number of days to obtain repeatability at different measurement times and assessed the effects of rainy days or weekend days on ST in patients with COPD. In Study 2, we detected the ST-related factors among 28 parameters and created a reference equation for ST using the detected factors.

Results

In Study 1, 38 patients with stable COPD were analyzed. The minimum number of days required for repeatability was 3 for 8-h wearing and 2 for 10-h wearing. The ST was significantly prolonged on rainy days, but not on weekends. In Study 2, 216 patients with stable COPD were analyzed. BMI, FEV1%pred, 6MWD, and mMRC were detected as ST-related factors, and a reference equation could be created using these four factors. The equation was validated for patients whose ST was ≥ 6 h.

Conclusion

By using properly processed measurement data of ST, we created a reference equation for assessing ST that is expected to be useful for providing individual guidance on the shortening of ST to patients with COPD.

Association between upper limb clinical tests and accelerometry metrics for arm use in daily life in children with unilateral cerebral palsy

PURPOSE

To evaluate the association between upper-limb (UL) clinical tests and UL accelerometry-derived metrics in children with unilateral Cerebral Palsy (CP).

METHODS

In this cross-sectional study, twenty children with unilateral CP and Manual Ability Classification System level I-III were included. Outcomes of the Assisting Hand Assessment, Box and Block-Test and accelerometry metrics were collected in the clinical setting and in daily life. UL asymmetry index (i.e., the ratio between the well-functioning UL and the affected UL use) was evaluated in different physical activity levels and relative use of UL was evaluated during daily living. Spearman's correlation was used to determine the association between UL clinical tests and accelerometry metrics in a clinical setting and in daily life.

RESULTS

The strongest negative association was between the Assisting Hand Assessment units and accelerometry metrics during the sedentary time in daily life (rs = -0.64). The asymmetries between ULs were highest during the child's sedentary time (asymmetry index: 45.15) compared to when the child was in light (asymmetry index: 23.97) or higher intensity physical activity (asymmetry index: 13.39). The children used both ULs simultaneously for 44% of the time during daily life.

CONCLUSION

Accelerometry metrics may provide additional objective information to clinical tests by quantifying the amount of UL movements and the amount of asymmetry between the upper limbs in daily life.

Is public transport a promising strategy for increasing physical activity? Evidence from a study of objectively measured public transport use and physical activity

BACKGROUND

Greater public transport use has been linked to higher physical activity levels. However, neither the amount of physical activity associated with each daily public transport trip performed, nor the potential total physical activity gain associated with an increase in trips/day, has been determined. Using objective measures, we aimed to quantify the association between public transport use, physical activity and sedentary time.

METHODS

A longitudinal study of Australian adults living in Hobart, Tasmania, who were infrequent bus users (≥ 18 years; used bus ≤ 2 times/week). The number of bus trips performed each day was determined from objective smartcard data provided by the public transportation (bus) provider across a 36-week study timeframe. Accelerometer measured steps/day (primary outcome), moderate-to-vigorous physical activity (min/day), and sedentary time (min/day) were assessed across four separate one-week periods.

RESULTS

Among 73 participants across 1483 day-level observations, on days that public transport was used, participants achieved significantly more steps (β = 2147.48; 95%CI = 1465.94, 2829.03), moderate to vigorous physical activity (β = 22.79; 95% CI = 14.33, 31.26), and sedentary time (β = 37.00; 95% CI = 19.80, 54.21) compared to days where no public transport trips were made. The largest increase in steps per day associated with a one-trip increase was observed when the number of trips performed each day increased from zero to one (β = 1761.63; 95%CI = 821.38, 2701.87). The increase in the number of steps per day was smaller and non-significant when the number of trips performed increased from one to two (β = 596.93; 95%CI=-585.16, 1779.01), and two to three or more (β = 632.39; 95%CI=-1331.45, 2596.24) trips per day. Significant increases in sedentary time were observed when the number of trips performed increased from zero to one (β = 39.38; 95%CI = 14.38, 64.39) and one to two (β = 48.76; 95%CI = 25.39, 72.12); but not when bus trips increased from two to three or more (β=-27.81; 95%CI=-76.00, 20.37).

CONCLUSIONS

Greater public transport use was associated with higher physical activity and sedentary behaviour. Bus use may yield cumulative increases in steps that amount to 15-30% of the daily recommended physical activity target. A policy and public health focus on intersectoral action to promote public transport may yield meaningful increases in physical activity and subsequent health benefits.

Algorithm Validation for Quantifying ActiGraph™ Physical Activity Metrics in Individuals with Chronic Low Back Pain and Healthy Controls

Assessing physical activity is important in the treatment of chronic conditions, including chronic low back pain (cLBP). ActiGraph™, a widely used physical activity monitor, collects raw acceleration data, and processes these data through proprietary algorithms to produce physical activity measures. The purpose of this study was to replicate ActiGraph™ algorithms in MATLAB and test the validity of this method with both healthy controls and participants with cLBP. MATLAB code was developed to replicate ActiGraph™'s activity counts and step counts algorithms, to sum the activity counts into counts per minute (CPM), and categorize each minute into activity intensity cut points. A free-living validation was performed where 24 individuals, 12 cLBP and 12 healthy, wore an ActiGraph™ GT9X on their non-dominant hip for up to seven days. The raw acceleration data were processed in both ActiLife™ (v6), ActiGraph™'s data analysis software platform, and through MATLAB (2022a). Percent errors between methods for all 24 participants, as well as separated by cLBP and healthy, were all less than 2%. ActiGraph™ algorithms were replicated and validated for both populations, based on minimal error differences between ActiLife™ and MATLAB, allowing researchers to analyze data from any accelerometer in a manner comparable to ActiLife™.

Long-Term Follow-Up of a Person-Centered Prehabilitation Program Based on Cognitive-Behavioral Physical Therapy for Patients Scheduled for Lumbar Fusion

OBJECTIVE

Long-term follow-ups of prehabilitation programs for lumbar spine surgery are lacking, and more comprehensive evaluations are needed. In the current study, we evaluated the long-term effects of a prehabilitation program compared with conventional care in relation to lumbar fusion surgery in patients with degenerative disc disease.

METHODS

Patients (n = 118) receiving lumbar fusion surgery were included in a multicenter randomized controlled trial, involving 1 university hospital and 2 spine clinics. The intervention was a person-centered prehabilitation program based on cognitive-behavioral physical therapy that targeted psychological presurgical risk factors, physical activity, and overall health. The control group received conventional preoperative care. Patient-reported outcome measures (PROMs) included assessments at 8 time-points: low back disability (primary outcome), back pain intensity, leg pain intensity, pain catastrophizing, fear of movement, anxiety and depressive mood, health-related quality of life, and patient-specific functioning. Physical activity and physical capacity were assessed at 5 time points. Linear mixed models were used to analyze the effects of the intervention.

RESULTS

There were no significant differences between groups at the 12- and 24-month follow-ups for any outcome, except for the One Leg Stand test 1 year following surgery, in favor of the control group. There were significant improvements for both groups, from baseline to the 12- and 24-month follow-ups for all physical capacity test and patient-reported outcome measures, except for leg pain and self-efficacy for exercise.

CONCLUSION

No long-term effects were found for the prehabilitation program compared to conventional care. Physical activity did not improve over time, despite significantly improved self-reported functioning and physical capacity measurements.

IMPACT

These findings have implications for the current understanding of the long-term effects of prehabilitation and suggest that future research should focus on programs promoting physical activity both before and after lumbar spine surgery to decrease the risk of long-term adverse health outcomes.

Associations Between Components of Self-Management Theory and Falls Among Older Adults

PURPOSE

To examine the relationship of key individual and family self-management theory (IFSMT) components, including self-management process variables on proximal (self-management behaviors) and distal (falls) outcomes in older adults.

METHOD

A secondary data analysis was conducted using data of 99 older adults living in continuing care retirement communities in the U.S. Midwest. Descriptive statistics, multiple regression, and logistic regression were performed to analyze the data.

RESULTS

The multiple regression model demonstrated a positive association between self-efficacy for physical activity and steps per day. The logistic regression model showed that high expectations regarding aging are associated with reduced likelihood of meeting daily protein intake.

CONCLUSION

Key components of the IFSMT, such as self-efficacy, steps per day, and expectations regarding aging, are important when designing self-management interventions to prevent falls. [Journal of Gerontological Nursing, 50(8), 19-28.].

An Aerobic Cooldown After Morning, Fasted Resistance Exercise Has Limited Impact on Post-exercise Hyperglycemia in Adults With Type 1 Diabetes: A Randomized Crossover Study

OBJECTIVES

Expert guidelines recommend an aerobic cooldown to lower blood glucose for the management of post-exercise hyperglycemia. This strategy has never been empirically tested. Our aim in this study was to compare the glycemic effects of performing an aerobic cooldown vs not performing a cooldown after a fasted resistance exercise session. We hypothesized that the cooldown would lower blood glucose in the 30 minutes after exercise and would result in less time in hyperglycemia in the 6 hours after exercise.

METHODS

Participants completed 2 identical resistance exercise sessions. One was followed by a low-intensity (30% of peak oxygen consumption) 10-minute cycle ergometer cooldown, and the other was followed by 10 minutes of sitting. We compared the changes in capillary glucose concentration during these sessions and continuous glucose monitoring (CGM) outcomes over 24 hours post-exercise.

RESULTS

Sixteen participants completed the trial. Capillary glucose was similar between conditions at the start of exercise (p=0.07). Capillary glucose concentration decreased by 0.6±1.0 mmol/L during the 10-minute cooldown, but it increased by 0.7±1.3 mmol/L during the same time in the no-cooldown condition. The resulting difference in glucose trajectory led to a significant interaction (p=0.02), with no effect from treatment (p=0.7). Capillary glucose values at the end of recovery were similar between conditions (p>0.05). There were no significant differences in CGM outcomes.

CONCLUSIONS

An aerobic cooldown reduces glucose concentration in the post-exercise period, but the small and brief nature of this reduction makes this strategy unlikely to be an effective treatment for hyperglycemia occurring after fasted exercise.

[Sarcopenia, physical activity and sedentary behavior among nursing home residents in Germany]

BACKGROUND

Residents in nursing homes show a high prevalence of the musculoskeletal syndrome sarcopenia and tend not to achieve current physical activity recommendations.

OBJECTIVE

The aim of this study is to identify differences in physical activity and sedentary behavior of sarcopenic residents compared with nonsarcopenic and presarcopenic residents.

METHODS

Sarcopenia assessment was performed among 63 nursing home residents in Baden-Wuerttemberg (D) using the European Working Group on Sarcopenia in Older People 2 specifications. Structured activity sessions (per week), accelerometer-based physical activity (steps/day), and sedentary behavior (percentual/day) were examined. The group comparisons were determined with Kruskal-Wallis tests and Dunn-Bonferroni post hoc tests.

RESULTS

Significant differences were found for number of steps (p = 0.005) and percentual sedentary behavior (p = 0.019). Moreover, steps per day presented significant results in group comparison for no sarcopenia (2824.4 [423-14275]) with probable sarcopenia (1703.9 [118-5663]) and confirmed/severe sarcopenia (1571.2 [240-2392]) (both p = 0.022; |r| = 0.34). Sedentary behavior demonstrated significant differences in groups with no sarcopenia (87.9% [69.1-94.3]) and with probable sarcopenia (91.7% [80.4-9835]) (p = 0.018; |r| = 0.35).

CONCLUSION

Nonsarcopenic residents demonstrated a higher number of steps and lower sedentary behavior compared with presarcopenic and sarcopenic residents. Increasing steps, reducing sedentary behavior and promoting activities of daily living can contribute to the prevention and treatment of sarcopenia in the nursing home setting.

Determinants of physical activity during cancer treatment: a longitudinal exploration of psycho-cognitive variables and physician counseling

Individuals with cancer are recommended to engage in regular physical activity (PA) even during cancer therapy. The aim of this study was to explore how patient-reported physician PA counseling influences their PA intention and behavior in addition to psycho-cognitive determinants derived from the theory of planned behavior (TPB). A longitudinal study during cancer treatment was conducted among N = 115 patients with breast, prostate, or colorectal cancer (Mage = 58.0, SD = 11.5; 55.7% female). The median time since diagnosis was 2 months, and 19.1% were diagnosed with metastases. Participants provided information on PA counseling by their physicians and on psycho-cognitive variables of the TPB at three measurement points. Additionally, they wore accelerometers for seven days at baseline and three months later. Nearly half of participants (48%) reported basic PA counseling and 30% reported in-depth PA counseling. Patients in poorer health and with lower education reported significantly less in-depth counseling. In addition to patient self-efficacy in performing PA, only in-depth physician PA counseling, but not basic physician counseling, predicted intention for PA four weeks later. Patients' PA three months after baseline was predicted by patients' PA at baseline and their intention for PA. Overall, the PA level at baseline was identified as the most important predictor of PA three months later. Nevertheless, physicians seem to have the ability to increase their cancer patients' intention for PA by in-depth counseling.

Criterion Validity and Reliability of 2 Brief Physical Activity Questionnaires in Ethnically Diverse Adults

PURPOSE

The study compares moderate- to vigorous-intensity physical activity (MVPA) as evaluated by the Exercise Vital Signs (EVS) and Physical Activity Vital Signs (PAVS) questionnaires to accelerometry, and evaluates the reliability of the questionnaires in ethnically diverse adults.

METHODS

Ninety-nine participants (mean age 38.1 y; 49.5% women; Hispanics 43.8%; European American 18.8%; African American 14.6%) were included in the analyses. Participants wore an accelerometer at the hip for at least 7 days and completed the EVS and PAVS questionnaires at the beginning (T1) and at the end (T2) of the 7 days. Associations between the questionnaires and accelerometry were examined using Spearman rho. The reliability of the questionnaires was evaluated using intraclass correlation coefficient. Sensitivity and specificity were also calculated.

RESULTS

Weak positive correlations were observed between the accelerometer MVPA and the EVS MVPA at T2 (ρ = .263, P = .013), and the PAVS MVPA at T2 (ρ = .327, P = .003). The sensitivity of the EVS and PAVS was 73.2% and 82.6%, respectively. The specificity for each questionnaire was 35.3%. The reliability for the EVS questionnaire (intraclass correlation coefficient = .855; 95% CI, .791-.901; P < .001) was good, while the reliability of the PAVS questionnaire (intraclass correlation coefficient = .652; 95% CI, .511-.758; P < .001) was moderate.

CONCLUSION

Caution should be used when utilizing the EVS and PAVS questionnaires in ethnically diverse adults.

Associations of Relative Intensity of Physical Activity With Incident Cardiovascular Events and All-Cause Mortality

BACKGROUND

The relative intensity of physical activity (PA) can be estimated as the percent of one's maximal effort required.

METHODS

We compared associations of relative and absolute intensity PA with incident major cardiovascular disease (CVD) and all-cause mortality in 5 633 women from the Objective Physical Activity and Cardiovascular Health Study (mean age 78.5 ± 6.7). Absolute intensity was measured by accelerometry. Relative intensity was estimated by dividing accelerometer-estimated metabolic equivalents (METs) by maximal MET capacity. Both were aggregated into mean daily hours of light intensity PA (LPA) and moderate-to-vigorous PA (MVPA). Cox proportional hazard models estimated hazard ratios (HRs) for 1-hour higher amounts of PA on outcomes.

RESULTS

During follow-up (median = 7.4 years), there were 748 incident CVD events and 1 312 deaths. Greater LPA and MVPA, on either scale, were associated with reduced risk of both outcomes. HRs for a 1-hour increment of absolute LPA were 0.88 (95% CI: 0.83-0.93) and 0.88 (95% CI: 0.84-0.92) for incident CVD and mortality, respectively. HRs for a 1-hour increment of absolute MPVA were 0.73 (95% CI: 0.61-0.87) and 0.55 (95% CI: 0.48-0.64) for the same outcomes. HRs for a 1-hour increment of relative LPA were 0.70 (95% CI: 0.59-0.84) and 0.78 (95% CI: 0.68-0.89) for incident CVD and mortality, respectively. HRs for a 1-hour increment of relative MPVA were 0.89 (95% CI: 0.83-0.96) and 0.82 (95% CI: 0.77-0.87) for the same outcomes. On the relative scale, LPA was more strongly, and inversely associated with both outcomes than relative MVPA. Absolute MVPA was more strongly inversely associated with the outcomes than relative MVPA.

CONCLUSIONS

Findings support the continued shift in the PA intensity paradigm toward recommendation of more movement, regardless of intensity. Relative LPA--a modifiable, more easily achieved behavioral target, particularly among ambulatory older adults--was associated with reduced risk of incident major CVD and death.

Monitoring Activity and Gait in Children (MAGIC) using digital health technologies

BACKGROUND

Digital health technologies (DHTs) can collect gait and physical activity in adults, but limited studies have validated these in children. This study compared gait and physical activity metrics collected using DHTs to those collected by reference comparators during in-clinic sessions, to collect a normative accelerometry dataset, and to evaluate participants' comfort and their compliance in wearing the DHTs at-home.

METHODS

The MAGIC (Monitoring Activity and Gait in Children) study was an analytical validation study which enrolled 40, generally healthy participants aged 3-17 years. Gait and physical activity were collected using DHTs in a clinical setting and continuously at-home.

RESULTS

Overall good to excellent agreement was observed between gait metrics extracted with a gait algorithm from a lumbar-worn DHT compared to ground truth reference systems. Majority of participants either "agreed" or "strongly agreed" that wrist and lumbar DHTs were comfortable to wear at home, respectively, with 86% (wrist-worn DHT) and 68% (lumbar-worn DHT) wear-time compliance. Significant differences across age groups were observed in multiple gait and activity metrics obtained at home.

CONCLUSIONS

Our findings suggest that gait and physical activity data can be collected from DHTs in pediatric populations with high reliability and wear compliance, in-clinic and in home environments.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04823650 IMPACT: Digital health technologies (DHTs) have been used to collect gait and physical activity in adult populations, but limited studies have validated these metrics in children. The MAGIC study comprehensively validates the performance and feasibility of DHT-measured gait and physical activity in the pediatric population. Our findings suggest that reliable gait and physical activity data can be collected from DHTs in pediatric populations, with both high accuracy and wear compliance both in-clinic and in home environments. The identified across-age-group differences in gait and activity measurements highlighted their potential clinical value.

Organised and non-organised activities contribute to overall physical activity levels in adolescents and young adults with Down syndrome: a cross-sectional study

BACKGROUND

Participation in organised and non-organised physical activities among adolescents and young adults with Down syndrome is underexplored. This study aimed to examine differences between organised and non-organised physical activities among adolescents and young adults with Down syndrome.

METHODS

Forty participants with Down syndrome (27 woman; mean age 21.4 ± 4.9 years) were recruited. Data on physical activity participation were collected by self- or proxy-reported questionnaires about attendance, involvement and type of physical activity.

RESULTS

Adolescents and young adults with Down syndrome participated in more organised than non-organised activities (P < 0.05), more often (P < 0.05), but there was no difference in the total time spent participating in these activities overall. Participants spent more time in vigorous physical activity during organised activities (P < 0.05) and spent more time in light physical activity during non-organised physical activities (P < 0.05). Dancing (organised activity) and walking (non-organised activity) were the most reported activities.

CONCLUSIONS

Participation in both organised and non-organised physical activities is important to increase overall physical activity levels of adolescents and young adults with Down syndrome. Future research exploring physical activity preferences may help guide the planning and adaption of community programmes for this group.

Safety & efficacy of a robotic hip exoskeleton on outpatient stroke rehabilitation

OBJECTIVE

The objective of this study was to analyze the safety and efficacy of using a robotic hip exoskeleton designed by Samsung Electronics Co., Ltd., Korea, called the Gait Enhancing and Motivating System-Hip (GEMS-H), in assistance mode only with the poststroke population in an outpatient-rehabilitation setting.

METHODS

Forty-one participants with an average age of 60 and average stroke latency of 6.5 years completed this prospective, single arm, interventional, longitudinal study during the COVID-19 pandemic. Significant modifications to the traditional outpatient clinical environment were made to adhere to organizational physical distancing policies as well as guidelines from the Centers for Disease Control. All participants received gait training with the GEMS-H in assistance mode for 18 training sessions over the course of 6-8 weeks. Performance-based and self-reported clinical outcomes were assessed at four time points: baseline, midpoint (after 9 training sessions), post (after 18 training sessions), and 1-month follow up. Daily step count was also collected throughout the duration of the study using an ankle-worn actigraphy device. Additionally, corticomotor excitability was measured at baseline and post for 4 bilateral lower limb muscles using transcranial magnetic stimulation.

RESULTS

By the end of the training program, the primary outcome, walking speed, improved by 0.13 m/s (p < 0.001). Secondary outcomes of walking endurance, balance, and functional gait also improved as measured by the 6-Minute Walk Test (47 m, p < 0.001), Berg Balance Scale (2.93 points, p < 0.001), and Functional Gait Assessment (1.80 points, p < 0.001). Daily step count significantly improved with and average increase of 1,750 steps per day (p < 0.001). There was a 35% increase in detectable lower limb motor evoked potentials and a significant decrease in the active motor threshold in the medial gastrocnemius (-5.7, p < 0.05) after training with the device.

CONCLUSIONS

Gait training with the GEMS-H exoskeleton showed significant improvements in walking speed, walking endurance, and balance in persons with chronic stroke. Day-to-day activity also improved as evidenced by increased daily step count. Additionally, corticomotor excitability changes suggest that training with this device may help correct interhemispheric imbalance typically seen after stroke.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov (NCT04285060).

Agreement Between Apple Watch and Actical Step Counts in a Community Setting: Cross-Sectional Investigation From the Framingham Heart Study

BACKGROUND

Step counting is comparable among many research-grade and consumer-grade accelerometers in laboratory settings.

OBJECTIVE

The purpose of this study was to compare the agreement between Actical and Apple Watch step-counting in a community setting.

METHODS

Among Third Generation Framingham Heart Study participants (N=3486), we examined the agreement of step-counting between those who wore a consumer-grade accelerometer (Apple Watch Series 0) and a research-grade accelerometer (Actical) on the same days. Secondarily, we examined the agreement during each hour when both devices were worn to account for differences in wear time between devices.

RESULTS

We studied 523 participants (n=3223 person-days, mean age 51.7, SD 8.9 years; women: n=298, 57.0%). Between devices, we observed modest correlation (intraclass correlation [ICC] 0.56, 95% CI 0.54-0.59), poor continuous agreement (29.7%, n=957 of days having steps counts with ≤15% difference), a mean difference of 499 steps per day higher count by Actical, and wide limits of agreement, roughly ±9000 steps per day. However, devices showed stronger agreement in identifying who meets various steps per day thresholds (eg, at 8000 steps per day, kappa coefficient=0.49), for which devices were concordant for 74.8% (n=391) of participants. In secondary analyses, in the hours during which both devices were worn (n=456 participants, n=18,760 person-hours), the correlation was much stronger (ICC 0.86, 95% CI 0.85-0.86), but continuous agreement remained poor (27.3%, n=5115 of hours having step counts with ≤15% difference) between devices and was slightly worse for those with mobility limitations or obesity.

CONCLUSIONS

Our investigation suggests poor overall agreement between steps counted by the Actical device and those counted by the Apple Watch device, with stronger agreement in discriminating who meets certain step thresholds. The impact of these challenges may be minimized if accelerometers are used by individuals to determine whether they are meeting physical activity guidelines or tracking step counts. It is also possible that some of the limitations of these older accelerometers may be improved in newer devices.

Physical Functioning, Physical Activity, and Variability in Gait Performance during the Six-Minute Walk Test

Instrumenting the six-minute walk test (6MWT) adds information about gait quality and insight into fall risk. Being physically active and preserving multi-directional stepping abilities are also important for fall risk reduction. This analysis investigated the relationship of gait quality during the 6MWT with physical functioning and physical activity. Twenty-one veterans (62.2 ± 6.4 years) completed the four square step test (FSST) multi-directional stepping assessment, a gait speed assessment, health questionnaires, and the accelerometer-instrumented 6MWT. An activity monitor worn at home captured free-living physical activity. Gait measures were not significantly different between minutes of the 6MWT. However, participants with greater increases in stride time (ρ = -0.594, p < 0.01) and stance time (ρ = -0.679, p < 0.01) during the 6MWT reported lower physical functioning. Neither physical activity nor sedentary time were related to 6MWT gait quality. Participants exploring a larger range in stride time variability (ρ = 0.614, p < 0.01) and stance time variability (ρ = 0.498, p < 0.05) during the 6MWT required more time to complete the FSST. Participants needing at least 15 s to complete the FSST meaningfully differed from those completing the FSST more quickly on all gait measures studied. Instrumenting the 6MWT helps detect ranges of gait performance and provides insight into functional limitations missed with uninstrumented administration. Established FSST cut points identify aging adults with poorer gait quality.

Relationship between quantitative physical activity and deterioration of locomotive function: a cross-sectional study using baseline data from a cohort

BACKGROUND

In aged society, health policies aimed at extending healthy life expectancy are critical. Maintaining physical activity is essential to prevent the deterioration of body functions. Therefore, it is important to understand the physical activity levels of the target age group and to know the content and intensity of the required physical activity quantitatively. Especially we focused the role of non-exercise activity thermogenesis and sedentary time, which are emphasized more than the introduction of exercise in cases of obesity or diabetes.

METHODS

A total of 193 patients from 25 institutions were included. Participants underwent a locomotive syndrome risk test (stand-up test, 2-step test, and Geriatric Locomotive Function Scale-25 questionnaire) and were classified into three stages. Physical activity was quantitatively monitored for one week with 3-axial accelerometer. Physical activity was classified into three categories; (1) Sedentary behavior (0 ∼ ≤ 1.5 metabolic equivalents (METs)), (2) Light physical activity (LPA:1.6 ∼ 2.9 METs), and (3) Moderate to vigorous physical activity (MVPA: ≥3 METs). We investigated the relationship between physical activity, including the number of steps, and the stages after gender- and age- adjustment. We also investigated the relationship between social isolation using Lubben's Social Network Scale (LSNS), as social isolation would lead to fewer opportunities to go out and less outdoor walking.

RESULTS

Comparison among the three stages showed significant difference for age (p = 0.007) and Body Mass Index (p < 0.001). After gender-and age-adjustment, there was a significant relation with a decrease in the number of steps (p = 0.002) and with MVPA. However, no relation was observed in sedentary time and LPA. LSNS did not show any statistically significant difference. Moderate to high-intensity physical activity and the number of steps is required for musculoskeletal disorders. The walking, not sedentary time, was associated to the locomotive stages, and this finding indicated the importance of lower extremity exercise.

CONCLUSIONS

Adjusting for age and gender, the number of steps and moderate to vigorous activity levels were necessary to prevent worsening, and there was no effect of sedentary behavior. Merely reducing sedentary time may be inadequate for locomotive disorders. It is necessary to engage in work or exercise that moves lower extremities more actively.

Sex differences in physical functioning among older adults: cross-sectional results from the OUTDOOR ACTIVE study

BACKGROUND

Maintaining good functional ability is a key component of healthy ageing and a basic requirement for carrying out activities of daily living, staying independent, and delaying admission to a nursing home. Even though women have a higher life expectancy and slower age-related muscle mass loss than men, they often show a higher prevalence of limitations in physical functioning. However, the reasons behind these sex differences are still unclear. Therefore, the aims of this study were to investigate sex differences among older adults regarding physical functioning and to study which factors are explaining these sex differences.

METHODS

Cross-sectional data from participants of the OUTDOOR ACTIVE study residing in Bremen, Germany, aged 65 to 75 years, were included in the analyses. Physical functioning was assessed via a self-administered questionnaire using the SF-36 10-item Physical Functioning Scale. Social, lifestyle, and health-related factors were also assessed using the questionnaire. Physical activity was measured objectively using wrist-worn accelerometers over seven consecutive days. Descriptive analyses with absolute and relative frequencies, means and standard deviations, as well as T-tests and chi-square tests were carried out. To test for associations between sex, physical functioning, and several individual factors, linear regressions were performed.

RESULTS

Data of 2 141 participants (52.1% female) were included in the study. Women and men showed statistically significant differences in physical functioning, with men perceiving fewer limitations than women. On average, women had a physical functioning score of 81.4 ± 19.3 and men 86.7 ± 17.0. Linear regression showed a statistically significant negative association between physical functioning score and sex (β: -0.15, 95% CL: -0.19, -0.10). The association remained statistically significant when adding individual factors to the model. All factors together were only able to explain 51% of the physical functioning-sex association with health indicators and the presence of chronic diseases being the most influential factors.

CONCLUSIONS

We found sex differences in physical functioning, with older women having more limitations than older men. The results showed that health-related factors and chronic diseases played the biggest roles in the different physical functioning scores of women and men. These findings contribute to future longitudinal, more in-depth research.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00015117 (Date of registration 17-07-2018).

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.

Clustering of 24H movement behaviors associated with clinic blood pressure in older adults: a cross-sectional study

Physical activity (PA), sedentary behavior (SB), and sleep duration are known to have an individual effect on clinic blood pressure (BP) of older adults. However, whether different patterns of these so-called movement behaviors over the 24h-cycle on BP remains poorly investigated. The study aimed to identify movement behavior patterns associated with clinic BP among older adults with chronic diseases. Cross-sectional study with 238 older adults (80.3% female; mean age 68.8 ± 6.6) with at least one chronic disease. PA, SB, and sleep duration were measured by a triaxial accelerometer. Clinic systolic BP (SBP) and diastolic BP (DBP) were obtained through an automated method following standard procedures. Non-hierarchical K-means cluster and linear regression modeling were employed to identify the clusters of movement behaviors and to examine the associations. Two clusters were identified [active and non-sedentary, n = 103 (i.e., sufficient sleep duration, higher LPA and MVPA, and lower SB) and sedentary and inactive, n = 135 (i.e., sufficient sleep duration, lower LPA and MVPA, and higher SB). Active and non-sedentary older adults presented lower systolic BP compared to sedentary and inactive ones, even after adjustments for sociodemographic and clinical characteristics (β = 6.356; CI 95% from 0.932 to 11.779; P = 0.022). No associations were found for diastolic BP. In conclusion, higher PA and lower SB were associated with lower systolic BP in older adults with chronic diseases. However, sleep duration did not modify this association. Therefore, interventions focusing on concomitantly increasing PA levels and reducing SB should be the priority for controlling blood pressure.

Differences in Daily Physical Activity by Alzheimer's Risk Markers Among Older Adults

BACKGROUND

Daily physical activity patterns differ by Alzheimer's disease (AD) status and might signal cognitive risk. It is critical to understand whether patterns are disrupted early in the AD pathological process. Yet, whether established AD risk markers (β-amyloid [Aβ] or apolipoprotein E-ε4 [APOE-ε4]) are associated with differences in objectively measured activity patterns among cognitively unimpaired older adults is unclear.

METHODS

Wrist accelerometry, brain Aβ (+/-), and APOE-ε4 genotype were collected in 106 (Aβ) and 472 (APOE-ε4) participants (mean age 76 [standard deviation{SD}: 8.5) or 75 [SD: 9.2] years, 60% or 58% women) in the Baltimore Longitudinal Study of Aging. Adjusted linear and function-on-scalar regression models examined whether Aβ or APOE-ε4 status was cross-sectionally associated with activity patterns (amount, variability, or fragmentation) overall and by time of day, respectively. Differences in activity patterns by combinations of Aβ and APOE-ε4 status were descriptively examined (n = 105).

RESULTS

There were no differences in any activity pattern by Aβ or APOE-ε4 status overall. Aβ+ was associated with lower total amount and lower within-day variability of physical activity overnight and early evening, and APOE-ε4 carriers had higher total amount of activity in the evening and lower within-day variability of activity in the morning. Diurnal curves of activity were blunted among those with Aβ+ regardless of APOE-ε4 status, but only when including older adults with mild cognitive impairment/dementia.

CONCLUSIONS

Aβ+ in cognitively unimpaired older adults might manifest as lower amount and variability of daily physical activity, particularly during overnight/evening hours. Future research is needed to examine changes in activity patterns in larger samples and by other AD biomarkers.

Historic Cognitive Function Trajectories as Predictors of Sedentary Behavior and Physical Activity in Older Adults

BACKGROUND

We examined whether trajectories of cognitive function over 10 years predict later-life physical activity (PA), sedentary time (ST), and sleep.

METHODS

Participants were from the Adult Changes in Thought (ACT) cohort study. We included 611 ACT participants who wore accelerometers and had 3+ measures of cognition in the 10 years prior to accelerometer wear. The Cognitive Assessment Screening Instrument (CASI) measured cognition and was scored using item-response theory (IRT). activPAL and ActiGraph accelerometers worn over 7 days measured ST and PA outcomes. Self-reported time in bed and sleep quality measured sleep outcomes. Analyses used growth mixture modeling to classify CASI-IRT scores into latent groups and examine associations with PA, ST, and sleep including demographic and health covariates.

RESULTS

Participants (Mean age = 80.3 (6.5) years, 90.3% White, 57.1% female, 29.3% had less than 16 years of education) fell into 3 latent trajectory groups: average stable CASI (56.1%), high stable CASI (34.0%), and declining CASI (9.8%). The declining group had 16 minutes less stepping time (95% confidence interval [95% CI]: 0.6, 31.4), 1 517 fewer steps per day (95% CI: 138, 2 896), and 16.3 minutes per day less moderate-to-vigorous PA (95% CI: 1.3, 31.3) compared to the average stable group. There were no associations between CASI trajectory and sedentary or sleep outcomes.

CONCLUSIONS

Declining cognition predicted lower PA providing some evidence of a reverse relationship between PA and cognition in older adults. However, this conclusion is limited by having outcomes at only one time point, a nonrepresentative sample, self-reported sleep outcomes, and using a global cognition measure.