Association of Daily Step Count and Step Intensity With Mortality Among US Adults

Objectively measured daily steps and health outcomes: an umbrella review of the systematic review and meta-analysis of observational studies

OBJECTIVES

The purpose of this review is to summarise the evidence from a systematic review and meta-analysis of observational studies that objectively measure daily steps and health outcomes.

DESIGN

This is an umbrella review.

DATA SOURCES

PubMed, Embase, Scopus, the Cochrane Library and Web of Science databases were searched through 31 January 2024.

ELIGIBILITY

We included systematic reviews of observational studies (with or without meta-analysis) that assessed the association of objectively measured daily steps with human health-related outcomes. Methodological quality was assessed using 'A MeaSurement Tool to Assess systematic Reviews 2'.

RESULTS

A total of 10 systematic reviews and 6 health outcomes were included after excluding irrelevant and duplicate studies. Higher daily steps were associated with more benefits than harms for a range of health-related outcomes, including all-cause mortality, cardiovascular event, skeletal muscle lesions, metabolic diseases and respiratory disease. A dose-response analysis showed that an increase of 500-1000 steps per day was associated with lower all-cause mortality and cardiovascular events. Beneficial associations were also found in patients with asthma and acutely hospitalised older adults. Conversely, one study within a systematic review suggested that higher daily steps (≥10 000) might be associated with an increased 52% risk of meniscal pathologies in individuals without knee osteoarthritis. However, one study within a systematic review suggested a potential increased risk of meniscal pathologies in individuals without knee osteoarthritis. Specifically, those exceeding 10 000 steps per day showed a 52% increase in risk.

CONCLUSION

The results of this study suggest that daily steps are associated with a lower risk of all-cause mortality and cardiovascular events. Future research could focus on identifying specific populations that may benefit most from increased daily steps and exploring potential mechanisms to enhance our understanding of how daily steps contribute to improved health outcomes.

PROSPERO REGISTRATION NUMBER

CRD42022347055.

Evaluation of Machine Learning to Detect Influenza Using Wearable Sensor Data and Patient-Reported Symptoms: Cohort Study

BACKGROUND

Machine learning offers quantitative pattern recognition analysis of wearable device data and has the potential to detect illness onset and monitor influenza-like illness (ILI) in patients who are infected.

OBJECTIVE

This study aims to evaluate the ability of machine-learning algorithms to distinguish between participants who are influenza positive and influenza negative in a cohort of symptomatic patients with ILI using wearable sensor (activity) data and self-reported symptom data during the latent and early symptomatic periods of ILI.

METHODS

This prospective observational cohort study used the extreme gradient boosting (XGBoost) classifier to determine whether a participant was influenza positive or negative based on 3 models using symptom-only data, activity-only data, and combined symptom and activity data. Data were collected from the Home Testing of Respiratory Illness (HTRI) study and FluStudy2020, both conducted between December 2019 and October 2020. The model was developed using the FluStudy2020 data and tested on the HTRI data. Analyses included participants in these studies with an at-home influenza diagnostic test result. Fitbit (Google LLC) devices were used to measure participants' steps, heart rate, and sleep parameters. Participants detailed their ILI symptoms, health care-seeking behaviors, and quality of life. Model performance was assessed by area under the curve (AUC), balanced accuracy, recall (sensitivity), specificity, precision (positive predictive value), negative predictive value, and weighted harmonic mean of precision and recall (F2) score.

RESULTS

An influenza diagnostic test result was available for 953 and 925 participants in HTRI and FluStudy2020, respectively, of whom 848 (89%) and 840 (90.8%) had activity data. For the training and validation sets, the highest performing model was trained on the combined symptom and activity data (training AUC=0.77; validation AUC=0.74) versus symptom-only (training AUC=0.73; validation AUC=0.72) and activity-only (training AUC=0.68; validation AUC=0.65) data. For the FluStudy2020 test set, the performance of the model trained on combined symptom and activity data was closely aligned with that of the symptom-only model (combined symptom and activity test AUC=0.74; symptom-only test AUC=0.74). These results were validated using independent HTRI data (combined symptom and activity evaluation AUC=0.75; symptom-only evaluation AUC=0.74). The top features guiding influenza detection were cough; mean resting heart rate during main sleep; fever; total minutes in bed for the combined model; and fever, cough, and sore throat for the symptom-only model.

CONCLUSIONS

Machine-learning algorithms had moderate accuracy in detecting influenza, suggesting that previous findings from research-grade sensors tested in highly controlled experimental settings may not easily translate to scalable commercial-grade sensors. In the future, more advanced wearable sensors may improve their performance in the early detection and discrimination of viral respiratory infections.

Adult Sports Participation and Physical Activity: How About Curling?

Despite its well-documented physical and psychosocial benefits, sport remains the least engaged form of physical activity (PA) among adults. Many adults may lack the skills needed to play or continue to play sports and aging adults are more likely to avoid participation for fear of poor performance or injury. A sport that shows great promise for adults seeking new sports participation outlets is curling. Curling is a team sport comprised of four interchangeable positions working collectively to deliver granite stones across a sheet of ice in an effort to outscore the opponent team. While it seems reasonable that walking on ice, "throwing" a 44 lb granite stone across a sheet of ice, and periodically sweeping while walking on ice over a two-hour period would generate at least a moderate amount of physical activity, research to date is quite limited. Therefore, the purpose of this study was to objectively measure the amount and intensity of PA achieved by average recreational curling participants during a typical curling match. Members of a curling club in NC were asked to wear ActiGraph Accelerometers (model GT3X) while they participated in their regularly scheduled curling match. All participants had at least one year of curling experience. Curling matches lasted between 90 and 120 minutes. Participants were asked to indicate their age, gender, and curling position during the match (lead, second, vice, skip) which were matched with accelerometer data. Overall, 110 participants (37 female, 73 male, avg. age 50 yrs) spent most of their curling time in light or moderate-intensity activity (18.1% Sedentary; 49.5% light; 32.4% moderate; .03% vigorous). In terms of minutes, the average participant spent 35.9 minutes engaged in Moderate-to-Vigorous PA (MVPA) per curling experience. This represents 23.9% of the weekly 150min of MVPA suggested by the CDC. Estimates of METs indicated that curling would be classified on the border of light and moderate physical activity. While total step data indicated that participation in beginning curling could make a significant contribution toward meeting the 10,000 - 13,000 daily step recommendation with an average of 2936 steps (~30%) within the curling sessions. The second position had the highest percentage of moderate activity level and a small percentage of vigorous activity. No other position reached a vigorous level. The skip position had the highest amount of sedentary activity as well as light activity. Females had a higher level of moderate activity in comparison to males. However, males reached a small amount of vigorous activity. The age group of 18 - 36 had the highest amount of moderate activity and the lowest amount of sedentary activity. This age group reached an average of 41.0 minutes of MVPA per curling experience. The age group of > 58 had the highest amount of sedentary activity and the lowest amount of moderate activity. Findings clearly show that regardless of position, curling participants achieved a moderate amount of physical activity during typical gameplay and that a majority of playing time was spent engaged in light or moderate levels. Participants should consider playing in one of the first three positions to maximize the amount and intensity of PA achieved while playing. Furthermore, since curling also requires balance, coordination, muscular strength, multitasking, strategic reasoning, and can cater to most physical challenges without compromising the integrity of the game, it may be an ideal sport to promote for adults of all ages and sport abilities. Findings should be used to inform strategies for promoting curling as an opportunity for team sport involvement that has the added value of contributing to daily physical activity. However, access and opportunities to play, especially for underserved populations, are limited. Given that most curling clubs in America are private and require a membership to play (Kanters, et. al, 2023), partnership arrangements between existing clubs and public parks and recreation departments could increase both access and opportunities to play.

Self-Supervised Machine Learning to Characterize Step Counts from Wrist-Worn Accelerometers in the UK Biobank

PURPOSE

Step count is an intuitive measure of physical activity frequently quantified in health-related studies; however, accurate step counting is difficult in the free-living environment, with error routinely above 20% in wrist-worn devices against camera-annotated ground truth. This study aimed to describe the development and validation of step count derived from a wrist-worn accelerometer and assess its association with cardiovascular and all-cause mortality in a large prospective cohort.

METHODS

We developed and externally validated a self-supervised machine learning step detection model, trained on an open-source and step-annotated free-living dataset. Thirty-nine individuals will free-living ground-truth annotated step counts were used for model development. An open-source dataset with 30 individuals was used for external validation. Epidemiological analysis was performed using 75,263 UK Biobank participants without prevalent cardiovascular disease (CVD) or cancer. Cox regression was used to test the association of daily step count with fatal CVD and all-cause mortality after adjustment for potential confounders.

RESULTS

The algorithm substantially outperformed reference models (free-living mean absolute percent error of 12.5% vs 65%-231%). Our data indicate an inverse dose-response association, where taking 6430-8277 daily steps was associated with 37% (25%-48%) and 28% (20%-35%) lower risk of fatal CVD and all-cause mortality up to 7 yr later, compared with those taking fewer steps each day.

CONCLUSIONS

We have developed an open and transparent method that markedly improves the measurement of steps in large-scale wrist-worn accelerometer datasets. The application of this method demonstrated expected associations with CVD and all-cause mortality, indicating excellent face validity. This reinforces public health messaging for increasing physical activity and can help lay the groundwork for the inclusion of target step counts in future public health guidelines.

Breast cancer and cardiovascular health

Modern cancer therapies greatly improve clinical outcomes for both early and advanced breast cancer patients. However, these advances have raised concerns about potential short- and long-term toxicities, including cardiovascular toxicities. Therefore, understanding the common risk factors and underlying pathophysiological mechanisms contributing to cardiovascular toxicity is essential to ensure best breast cancer outcomes. While cardio-oncology has emerged as a sub-speciality to address these challenges, it is essential that all cardiologists recognize and understand the cardiovascular consequences of cancer therapy. This review aims to provide a comprehensive overview of the potential adverse cardiovascular effects associated with modern breast cancer therapies. A preventive, diagnostic, and therapeutic workflow to minimize the impact of cardiovascular toxicity on patient outcomes is presented. Key aspects of this workflow include regular monitoring of cardiovascular function, early detection and management of cancer therapy-related cardiovascular toxicities, and optimization of cardiovascular risk factor control. By highlighting the gaps in knowledge in some areas, this review aims to emphasize the critical role of cardio-oncology research in ensuring the holistic well-being of patients with breast cancer.

Replacement of sedentary behavior with various physical activities and the risk of all-cause and cause-specific mortality

BACKGROUND

Sedentary behavior (SB) has emerged as a significant health concern that deserves attention. This study aimed to examine the associations between prolonged sedentary behavior and the risk of all-cause and cause-specific mortality as well as to explore desirable alternatives to sitting in terms of physical activity (PA).

METHODS

Two prospective cohort investigations were conducted using the UK Biobank and NHANES datasets, with a total of 490,659 and 33,534 participants, respectively. Cox proportional hazards regression models were used to estimate the associations between SB and the risk of all-cause and cause-specific mortality due to cancer, cardiovascular disease (CVD), respiratory diseases, and digestive diseases. In addition, we employed isotemporal substitution models to examine the protective effect of replacing sitting with various forms of PA.

RESULTS

During the average follow-up times of 13.5 and 6.7 years, 36,109 and 3057 deaths were documented in the UK Biobank and NHANES, respectively. Both cohorts demonstrated that, compared with individuals sitting less than 5 h per day, individuals with longer periods of sitting had higher risks of all-cause and cause-specific mortality due to cancer, CVD, and respiratory diseases but not digestive diseases. Moreover, replacing SB per day with PA, even substituting 30 min of walking for pleasure, reduced the risk of all-cause mortality by 3.5% (hazard ratio [HR] 0.965, 95% confidence interval [CI] 0.954-0.977), whereas cause-specific mortality from cancer, CVD, and respiratory diseases was reduced by 1.6% (HR 0.984, 95% CI 0.968-1.000), 4.4% (HR 0.956, 95% CI 0.930-0.982), and 15.5% (HR 0.845, 95% CI 0.795-0.899), respectively. Furthermore, the protective effects of substitution became more pronounced as the intensity of exercise increased or the alternative duration was extended to 1 h.

CONCLUSIONS

SB was significantly correlated with substantially increased risks of all-cause mortality and cause-specific mortality from cancer, CVD, and respiratory diseases. However, substituting sitting with various forms of PA, even for short periods involving relatively light and relaxing physical activity, effectively reduced the risk of both overall and cause-specific mortality.

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.

The association between 'weekend warrior', regular exercise, and cognitive function in elderly individuals with and without depressive symptoms: A cross-sectional analysis from NHANES 2011-2014

BACKGROUND

While previous studies have suggested that both 'Weekend Warrior' (WW) and Regular Exercise (RE) patterns confer health benefits, the relationship between different types of physical activity (PA) and cognitive function (CF) in elderly individuals with and without depressive symptoms remains unclear.

METHODS

Our study leveraged the NHANES 2011-2014 dataset, focusing on older adults. We explore the relationship between PA and CF, stratifying by depressive status. Our statistical approach included multivariable regression analysis to identify relationships between PA levels and cognitive outcomes, along with advanced techniques such as smoothed curve fitting and threshold effect analysis to examine potential nonlinear associations and identify optimal PA pattern for cognitive health.

RESULTS

Analysis revealed a positive correlation between PA time and CF across all participants (β-depressive symptoms = 0.03, 95 % CI: 0.01-0.05; β-non-depressive symptoms = 0.01, 95%CI: 0.00-0.02). When comparing against the inactive, non-depressed participants partaking in WW showed improved cognitive scores (β-WW = 0.22, 95 % CI: 0.05-0.39), similar to those engaging in RE (β-RE = 0.15, 95 % CI: 0.09-0.21). However, among the depressed participants, significant cognitive improvements were observed in the RE (β-RE = 0.15, 95 % CI: 0.04-0.25), with the WW showing less definitive results (β-WW = 0.22, 95 % CI: -0.02-0.47).

LIMITATION

The cross-sectional nature limits causal inferences.

CONCLUSION

Our findings affirm the potential role of PA in enhancing CF among older subjects without depressive symptoms. However, only RE was associated with improved CF in those with depressive symptoms. These results are critical for crafting personalized PA guidelines to enhance cognitive health in the aging population.

Effect of wearable activity trackers on physical activity in children and adolescents: a systematic review and meta-analysis

BACKGROUND

Physical inactivity in children and adolescents has become a pressing public health concern. Wearable activity trackers can allow self-monitoring of physical activity behaviour and promote autonomous motivation for exercise. However, the effects of wearable trackers on physical activity in young populations remain uncertain.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, SPORTDiscus, and Web of Science for publications from database inception up to Aug 30, 2023, without restrictions on language. Studies were eligible if they were randomised controlled trials or clustered randomised controlled trials that examined the use of wearable activity trackers to promote physical activity, reduce sedentary behaviours, or promote overall health in participants with a mean age of 19 years or younger, with no restrictions on health condition or study settings. Studies were excluded if children or adolescents were not the primary intervention cohort, or wearable activity trackers were not worn on users' bodies to objectively track users' physical activity levels. Two independent reviewers (WWA and FR) assessed eligibility of studies and contacted authors of studies if more information was needed to assess eligibility. We also searched reference lists from relevant systematic reviews and meta-analyses. Systematic review software Covidence was used for study screening and data extraction. Study characteristics including study setting, participant characteristics, intervention characteristics, comparator, and outcome measurements were extracted from eligible studies. The two primary outcomes were objectively measured daily steps and moderate-to-vigorous physical activity. We used a random-effects model with Hartung-Knapp adjustments to calculate standardised mean differences. Between-study heterogeneity was examined using Higgins I2 and Cochran Q statistic. Publication bias was assessed using Egger's regression test. This systematic review was registered with PROSPERO, CRD42023397248.

FINDINGS

We identified 9619 studies from our database research and 174 studies from searching relevant systematic reviews and meta-analyses, of which 105 were subjected to full text screening. We included 21 eligible studies, involving 3676 children and adolescents (1618 [44%] were female and 2058 [56%] were male, mean age was 13·7 years [SD 2·7]) in our systematic review and meta-analysis. Ten studies were included in the estimation of the effect of wearable activity trackers on objectively measured daily steps and 11 were included for objectively measured moderate-to-vigorous physical activity. Compared with controls, we found a significant increase in objectively measured daily steps (standardised mean difference 0·37 [95% CI 0·09 to 0·65; p=0·013]; Q 47·60 [p<0·0001]; I2 72·7% [95% CI 53·4 to 84·0]), but not for moderate-to-vigorous physical activity (-0·08 [-0·18 to 0·02; p=0·11]; Q 10·26 [p=0·74]; I2 0·0% [0·0 to 53·6]).

INTERPRETATION

Wearable activity trackers might increase daily steps in young cohorts of various health statuses, but not moderate-to-vigorous physical activity, highlighting the potential of wearable trackers for motivating physical activity in children and adolescents. More rigorously designed trials that minimise missing data are warranted to validate our positive findings on steps and to explore possible long-term effects.

FUNDING

The Hong Kong University Grants Committee and Seed Fund for Basic Research of the University of Hong Kong.

Effects of a digital intervention on physical activity in adults: A randomized controlled trial in a large-scale sample

Background

Physical inactivity is associated with health risks, contributing to various diseases and all-cause mortality. Despite recommendations for regular physical activity (PA), many adults remain inactive, influenced by socioeconomic and environmental factors. Digital interventions, particularly web-based PA programs, offer promising possibilities to promote PA across populations. These programs vary in their effectiveness, reflecting differences in design, user engagement, and behavior change techniques employed.

Objective

This study evaluates the effectiveness of the 12-week multimodal web-based TKFitnessCoach. The PA online program is part of the TK-HealthCoach. This study investigates the program's impact on self-reported PA levels, goal attainment, healthrelated quality of life, body weight, and eating behavior, comparing an interactive personalized web-based intervention and non-interactive web-based health information.

Methods

In a randomized controlled trial (RCT), participants were allocated to either the intervention group (IG), receiving access to the interactive TK-FitnessCoach, or the control group (CG) that was provided a static website with evidence-based information on PA. The study targeted a German-speaking adult population interested in improving health behavior. Data was assessed at T0 (beginning of the study), T1 (postintervention), T2, 6 months, and T3, 12 months follow-ups, focusing on self-reported PA at T3 and on various secondary outcomes.

Results

We achieved equally distributed sociodemographics in both the IG and the CG with a mean age of 42.8 (IG), resp. 43.1 years (CG), and female participants of 76.1 % (IG), resp. 74.7 % (CG). PA at baseline was 277.9 min/week in the IG and 273.3 min/week in the CG. Both, the IG (n = 1153 in the Intention-to-treat (ITT) dataset) and CG (n = 1177 in the ITT dataset) exhibited significant increases in PA over time (IG(T3-T0) = 72.92 min/week; CG(T3-T0) = 74.12 min/week).However, the study did not find significant differences in the effectiveness of the interactive TK-FitnessCoach compared to the non-interactive control in terms of improving PA and related health outcomes. The intensity of using the TK-FitnessCoach was not associated with PA.

Conclusions

Both programs were effective in promoting PA among adults, with no significant differences observed between the two RCT groups. This highlights the potential of digital interventions in addressing physical inactivity, suggesting that the effectiveness of such programs may not solely depend on their interactivity but also on the quality and relevance of the information provided. Further research is needed to explore optimization strategies for such interventions, especially for persons with low PA, including user engagement, behavior change techniques, and the integration of objective PA tracking methods.

Trial registration

German Clinical Trials Register DRKS00020249; https://drks.de/search/en/trial/DRKS00020249.

Association Between Physical Activity Amount and Cardiorespiratory Fitness, Sleep Quality, and Health-Related Quality of Life in Patients With Long COVID: A Cross-sectional Study

OBJECTIVE

To investigate the association between physical activity (PA) amount and gender differences on cardiorespiratory fitness (CRF), sleep quality, and health-related quality of life (HRQoL) in individuals with long COVID.

DESIGN

Cross-sectional study.

SETTING

An integrated outpatient clinic for post-COVID-19 at a medical center.

PARTICIPANTS

Convenience sample of patients (N=264) diagnosed with long COVID.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

PA amounts, sleep quality, and HRQoL were measured by the International Physical Activity Questionnaire, Pittsburgh Sleep Quality Index, and the World Health Organization Questionnaire on Quality of Life: Short Form, respectively. CRF was evaluated through graded exercise testing.

RESULTS

The participants had a mean age of 42.5±13.5 years and a mean duration of post-COVID-19 symptoms of 12.7±6.8 weeks. More than half (n=149, 56.5%) were female patients. Female participants had significantly lower CRF than male participants (P<.05). Older age and higher body mass index were associated with worse CRF and HRQoL (P<.05). Less sitting behavior and greater amounts of vigorous-intensity PA (VPA) or total PA were associated with better CRF (P<.05). In addition, greater total PA and moderate-intensity PA (MPA) were associated with better sleep quality and HRQoL (P<.05), respectively.

CONCLUSIONS

Gender differences were found in CRF among patients with long COVID. Greater self-reported VPA or total PA was associated with better CRF, whereas greater total PA and MPA were associated with better sleep quality and HRQoL, respectively, in patients with long COVID. Further research is needed to explore these associations in longitudinal studies.

Standardizing Continuous Physical Activity Monitoring in Patients with Cervical Spondylosis

STUDY DESIGN/SETTING

Prospective cohort study.

OBJECTIVE

To use a commercial wearable device to measure real-life, continuous physical activity in patients with CS and to establish age-adjusted and sex-adjusted standardized scores.

SUMMARY OF BACKGROUND DATA

Patients with cervical spondylosis (CS) often present with pain or neurologic deficits that result in functional limitations and inactivity. However, little is known regarding the influence of CS on the patient's real-life physical activity.

METHODS

This study included 100 English-speaking adult patients with cervical degenerative diseases undergoing elective spine surgery at Stanford University who owned iPhones. Patients undergoing surgery for spine infections, trauma, tumors, or lumbar degenerative disease were excluded. Activity two weeks before surgery was expressed as raw daily step counts. Standardized z-scores were calculated based on age-specific and sex-specific values of a control population. Responses to patient-reported outcome measures (PROMs) surveys assessed convergent validity. Functional impairment was categorized based on predetermined z-score cut-off values.

RESULTS

Thirty CS with a mean (±SD) age of 56.0 (±13.4) y wore an Apple Watch for ≥8 hours/day in 87.1% of the days. The mean watch wear time was 15.7 (±4.2) hours/day, and the mean daily step count was 6400 (±3792). There was no significant difference in activity between 13 patients (43%) with myelopathy and 17 (57%) without myelopathy. Test-retest reliability between wearable step count measurements was excellent (ICC β=0.95). Physical activity showed a moderate positive correlation with 36-Item Short Form Survey Physical Component Summary, EuroQol-5-dimension visual analog scale, and Patient-Reported Outcomes Measurement Information System Physical Function Subscale. Activity performance was classified into categories of "no impairment" [step count=9640 (±2,412)], "mild impairment" [6054(±816)], "moderate impairment" [3,481 (±752)], and "severe impairment" [1,619 (±240)].

CONCLUSION

CS patients' physical activity is significantly lower than the general population or the frequently stated goals of 7000 to 10,000 steps/day. Standardized, continuous wearable physical activity monitoring in CS is a reliable, valid, and normalized outcome tool that may help characterize functional impairment before and after spinal interventions.

Association of Wearable Device-Measured Step Volume and Variability With Blood Pressure in Older Chinese Adults: Mobile-Based Longitudinal Observational Study

BACKGROUND

The paucity of evidence on longitudinal and consecutive recordings of physical activity (PA) and blood pressure (BP) under real-life conditions and their relationships is a vital research gap that needs to be addressed.

OBJECTIVE

This study aims to (1) investigate the short-term relationship between device-measured step volume and BP; (2) explore the joint effects of step volume and variability on BP; and (3) examine whether the association patterns between PA and BP varied across sex, hypertension status, and chronic condition status.

METHODS

This study used PA data of a prospective cohort of 3070 community-dwelling older adults derived from a mobile health app. Daily step counts, as a proxy of step volume, were derived from wearable devices between 2018 and 2022 and categorized into tertiles (low, medium, and high). Step variability was assessed using the SD of daily step counts. Consecutive daily step count recordings within 0 to 6 days preceding each BP measurement were analyzed. Generalized estimation equation models were used to estimate the individual and joint associations of daily step volume and variability with BP. Stratified analyses by sex, the presence of hypertension, and the number of morbidities were further conducted.

RESULTS

A total of 3070 participants, with a median age of 72 (IQR 67-77) years and 71.37% (2191/3070) women, were included. Participants walked a median of 7580 (IQR 4972-10,653) steps and 5523 (IQR 3590-7820) meters per day for a total of 592,597 person-days of PA monitoring. Our results showed that higher levels of daily step volume were associated with lower BP (systolic BP, diastolic BP, mean arterial pressure, and pulse pressure). Compared with participants with low step volume (daily step counts <6000/d) and irregular steps, participants with high step volume (≥9500/d) and regular steps showed the strongest decrease in systolic BP (-1.69 mm Hg, 95% CI -2.2 to -1.18), while participants with medium step volume (6000/d to <9500/d) and regular steps were associated with the lowest diastolic BP (-1.067 mm Hg, 95% CI -1.379 to -0.755). Subgroup analyses indicated generally greater effects on women, individuals with normal BP, and those with only 1 chronic disease, but the effect pattern was varied and heterogeneous between participants with different characteristics.

CONCLUSIONS

Increased step volume demonstrated a substantial protective effect on BP among older adults with chronic conditions. Furthermore, the beneficial association between step volume and BP was enhanced by regular steps, suggesting potential synergistic protective effects of both increased step volume and step regularity. Targeting both step volume and variability through PA interventions may yield greater benefits in BP control, particularly among participants with hypertension and a higher chronic disease burden.

The Impact of a Gamified Intervention on Daily Steps in Real-Life Conditions: Retrospective Analysis of 4800 Individuals

BACKGROUND

Digital interventions integrating gamification features hold promise to promote daily steps. However, results regarding the effectiveness of this type of intervention are heterogeneous and not yet confirmed in real-life contexts.

OBJECTIVE

This study aims to examine the effectiveness of a gamified intervention and its potential moderators in a large sample using real-world data. Specifically, we tested (1) whether a gamified intervention enhanced daily steps during the intervention and follow-up periods compared to baseline, (2) whether this enhancement was higher in participants in the intervention than in nonparticipants, and (3) what participant characteristics or intervention parameters moderated the effect of the program.

METHODS

Data from 4819 individuals who registered for a mobile health Kiplin program between 2019 and 2022 were retrospectively analyzed. In this intervention, participants could take part in one or several games in which their daily step count was tracked, allowing individuals to play with their overall activity. Nonparticipants were people who registered for the program but did not take part in the intervention and were considered as a control group. Daily step counts were measured via accelerometers embedded in either commercial wearables or smartphones of the participants. Exposure to the intervention, the intervention content, and participants' characteristics were included in multilevel models to test the study objectives.

RESULTS

Participants in the intervention group demonstrated a significantly greater increase in mean daily steps from baseline than nonparticipants (P<.001). However, intervention effectiveness depended on participants' initial physical activity. The daily steps of participants with <7500 baseline daily steps significantly improved from baseline both during the Kiplin intervention (+3291 daily steps) and the follow-up period (+945 daily steps), whereas participants with a higher baseline had no improvement or significant decreases in daily steps after the intervention. Age (P<.001) and exposure (P<.001) positively moderated the intervention effect.

CONCLUSIONS

In real-world settings and among a large sample, the Kiplin intervention was significantly effective in increasing the daily steps of participants from baseline during intervention and follow-up periods compared to nonparticipants. Interestingly, responses to the intervention differed based on participants' initial steps, with the existence of a plateau effect. Drawing on the insights of self-determination theory, we can assume that the effect of gamification could depend of the initial motivation and activity of participants.

Daily steps and all-cause mortality: An umbrella review and meta-analysis

OBJECTIVE

This study aimed to describe the variability in estimates of the association of daily steps and all-cause mortality in systematic reviews with meta-analyses, to identify the factors potentially responsible for it, and to provide an updated estimate.

METHODS

Five databases were systematically searched up to May 2024 to identify systematic reviews with meta-analyses and prospective cohort studies. A qualitative synthesis of previous reviews and an updated meta-analysis of cohort studies were performed. Pooled hazard ratios (HRs) with their 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

Eleven systematic reviews with meta-analyses and 14 cohort studies were included, revealing considerable variability in result presentation. Our updated meta-analysis showed a nonlinear association, indicating a lower risk of all-cause mortality with increased daily steps, with a protective threshold at 3143 steps/day, and a pooled HR of 0.91 (95% CI: 0.87, 0.95) per 1000 steps/day increment. Physical activity categories consistently indicated progressively reduced mortality risk, with the highly active category (>12,500 steps/day) exhibiting the lowest risk (0.35 (95% CI: 0.29, 0.42)).

CONCLUSION

Systematic reviews and meta-analyses showed considerable variability in effect estimates due to different methods of quantifying exposure. Despite it, our study underscores the importance of increased daily steps in reducing all-cause mortality, with a minimum protective dose of 3000 steps/day, although the optimal dose differed according to age and sex. It is recommended that future studies categorise daily steps by physical activity category, perform dose-response analyses, and use increments of 1000 steps/day.

Effect of Physical Activity on the Association Between Diet and Constipation: Evidence From the National Health and Nutrition Examination Survey 2007-2010

Background/Aims

Previous studies have shown that diet and physical activity can influence constipation. However, the combined effect of diet and physical activity on constipation remains unclear.

Methods

Constipation was defined based on stool consistency and frequency, while overall diet quality was assessed using Healthy Eating Index (HEI)-2015 scores. Participants were categorized into low (metabolic equivalent [MET]-min/wk < 500) and high physical activity groups (MET-min/wk ≥ 500). The association between diet and constipation across physical activity groups was analyzed using survey logistic regression and restricted cubic splines.

Results

Higher HEI-2015 scores were associated with reduced constipation risk in the high physical activity group when constipation was defined by stool consistency (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97-0.99). However, in the low physical activity group, increased HEI-2015 scores did not significantly affect constipation risk (OR, 1.01; 95% CI, 0.97-1.05). Similar results were found when constipation was defined based on stool frequency. In the high physical activity group, increased HEI-2015 scores were significantly associated with a reduced constipation risk (OR, 0.96; 95% CI, 0.94-0.98). Conversely, in the low physical activity group, increased HEI-2015 scores did not affect the risk of constipation (OR, 0.96; 95% CI, 0.90-1.03).

Conclusions

Our findings suggest that a higher HEI-2015 score is negatively associated with constipation among individuals with high physical activity levels but not among those with low physical activity levels. This association was consistent when different definitions of constipation were used. These results highlight the importance of combining healthy diet with regular physical activity to alleviate constipation.

Do Measures of Real-World Physical Behavior Provide Insights Into the Well-Being and Physical Function of Cancer Survivors? Cross-Sectional Analysis

BACKGROUND

As the number of cancer survivors increases, maintaining health-related quality of life in cancer survivorship is a priority. This necessitates accurate and reliable methods to assess how cancer survivors are feeling and functioning. Real-world digital measures derived from wearable sensors offer potential for monitoring well-being and physical function in cancer survivorship, but questions surrounding the clinical utility of these measures remain to be answered.

OBJECTIVE

In this secondary analysis, we used 2 existing data sets to examine how measures of real-world physical behavior, captured with a wearable accelerometer, were related to aerobic fitness and self-reported well-being and physical function in a sample of individuals who had completed cancer treatment.

METHODS

Overall, 86 disease-free cancer survivors aged 21-85 years completed self-report assessments of well-being and physical function, as well as a submaximal exercise test that was used to estimate their aerobic fitness, quantified as predicted submaximal oxygen uptake (VO2). A thigh-worn accelerometer was used to monitor participants' real-world physical behavior for 7 days. Accelerometry data were used to calculate average values of the following measures of physical behavior: sedentary time, step counts, time in light and moderate to vigorous physical activity, time and weighted median cadence in stepping bouts over 1 minute, and peak 30-second cadence.

RESULTS

Spearman correlation analyses indicated that 6 (86%) of the 7 accelerometry-derived measures of real-world physical behavior were not significantly correlated with Functional Assessment of Cancer Therapy-General total well-being or linked Patient-Reported Outcomes Measurement Information System-Physical Function scores (Ps≥.08). In contrast, all but one of the physical behavior measures were significantly correlated with submaximal VO2 (Ps≤.03). Comparing these associations using likelihood ratio tests, we found that step counts, time in stepping bouts over 1 minute, and time in moderate to vigorous activity were more strongly associated with submaximal VO2 than with self-reported well-being or physical function (Ps≤.03). In contrast, cadence in stepping bouts over 1 minute and peak 30-second cadence were not more associated with submaximal VO2 than with the self-reported measures (Ps≥.08).

CONCLUSIONS

In a sample of disease-free cancer survivors, we found that several measures of real-world physical behavior were more associated with aerobic fitness than with self-reported well-being and physical function. These results highlight the possibility that in individuals who have completed cancer treatment, measures of real-world physical behavior may provide additional information compared with self-reported and performance measures. To advance the appropriate use of digital measures in oncology clinical research, further research evaluating the clinical utility of real-world physical behavior over time in large, representative samples of cancer survivors is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03781154; https://clinicaltrials.gov/ct2/show/NCT03781154.

Exploring the association of physical activity on cognitive function in older adults from observational and genetic insights: a combined NHANES and Mendelian randomization study

Background

Cognitive function (CF) deterioration is a pressing concern in geriatric research. This study aimed to explore the relationship between physical activity (PA) and CF in older adults.

Methods

This study adopted a dual approach, employing both observational and genetic approaches through data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 and Mendelian Randomization (MR) analysis. For the NHANES component, PA levels were evaluated using the Global Physical Activity Questionnaire, and CF was assessed via standardized tests. Multivariate regression, threshold effect analysis, smoothing curve fitting, and subgroup analyses were conducted to examine the association between PA and CF. In parallel, MR methods, using genetic variants as instrumental variables, assessed the causal impact of PA on CF and related conditions such as Alzheimer's disease and dementia.

Results

Observational findings from NHANES demonstrated a positive correlation between PA and CF, notably among female participants. The detailed analysis identified specific thresholds of PA that correlate with cognitive enhancements. However, MR results did not support a significant causal relationship between PA and CF or dementia-related outcomes, indicating an absence of a direct genetic basis for the observational associations.

Conclusion

Although observational data from NHANES suggest that PA is positively associated with CF in older adults, particularly among women, MR analysis did not confirm these findings as causally related. The discrepancy highlights the complexity of the PA-CF relationship and underscores the need for further research. These results emphasize the potential of PA as a modifiable risk factor for CF, though causal effects remain to be definitively established.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predicting Goal Attainment in Process-Oriented Behavioral Interventions Using a Data-Driven System Identification Approach

Behavioral interventions (such as those developed to increase physical activity, achieve smoking cessation, or weight loss) can be represented as dynamic process systems incorporating a multitude of factors, ranging from cognitive (internal) to environmental (external) influences. This facilitates the application of system identification and control engineering methods to address questions such as: what drives individuals to improve health behaviors (such as engaging in physical activity)? In this paper, the goal is to efficiently estimate personalized, dynamic models which in turn will lead to control systems that can optimize this behavior. This problem is examined in system identification applied to the Just Walk study that aimed to increase walking behavior in sedentary adults. The paper presents a Discrete Simultaneous Perturbation Stochastic Approximation (DSPSA)-based modeling of the Goal Attainment construct estimated using AutoRegressive with eXogenous inputs (ARX) models. Feature selection of participants and ARX order selection is achieved through the DSPSA algorithm, which efficiently handles computationally expensive calculations. DSPSA can search over large sets of features as well as regressor structures in an informed, principled manner to model behavioral data within reasonable computational time. DSPSA estimation highlights the large individual variability in motivating factors among participants in Just Walk, thus emphasizing the importance of a personalized approach for optimized behavioral interventions.

Physical Activity and Public Health for Adults: Is the Glass Mostly Empty or Half Full?

ABSTRACT

Early observations that only a small proportion of U.S. adults were engaging in enough aerobic physical activity to provide substantial health benefit helped shape our public health messaging for physical activity. This messaging has consistently indicated that most adults should increase their activity levels. However, it has been difficult to accurately estimate the proportion of adults who engage in sufficient levels of aerobic activity in the population, with survey-based estimates ranging from 22% in 1994 to 54% in 2018 and widely differing estimates from device-based measures. Recent accelerometer-based studies of physical activity and mortality risk provide new evidence that at least 50% of U.S. adults engage in enough aerobic physical activity to be at low risk for premature mortality. We argue that this observation should lend greater confidence to our current survey-based surveillance estimates, which indicate that a large proportion of adults is physically active. This new insight may also provide clues that could further strengthen our public health messaging for physical activity by placing more emphasis on the maintenance of healthy activity levels throughout life and possibly by using descriptive social norms as an additional intervention element-while continuing current efforts to encourage the adoption of healthy activity levels for less active adults in the population.

Time- vs Step-Based Physical Activity Metrics for Health

Importance

Current US physical activity (PA) guidelines prescribe moderate to vigorous PA (MVPA) time of at least 150 minutes per week for health. An analogous step-based recommendation has not been issued due to insufficient evidence.

Objective

To examine the associations of MVPA time and step counts with all-cause mortality and cardiovascular disease (CVD).

Design, Setting, and Participants

This cohort study analyzed data from an ongoing follow-up study of surviving participants of the Women's Health Study, a randomized clinical trial conducted from 1992 to 2004 in the US to evaluate use of low-dose aspirin and vitamin E for preventing cancer and CVD. Participants were 62 years or older who were free from CVD and cancer, completed annual questionnaires, and agreed to measure their PA with an accelerometer as part of a 2011-2015 ancillary study. Participants were followed up through December 31, 2022.

Exposures

Time spent in MVPA and step counts, measured with an accelerometer for 7 consecutive days.

Main Outcomes and Measures

The associations of MVPA time and step counts with all-cause mortality and CVD (composite of myocardial infarction, stroke, and CVD mortality) adjusted for confounders. Cox proportional hazards regression models, restricted mean survival time differences, and area under the receiver operating characteristic curve (AUC) were used to evaluate the associations.

Results

A total of 14 399 women (mean [SD] age, 71.8 [5.6] years) were included. The median (IQR) MVPA time and step counts were 62 (20-149) minutes per week and 5183 (3691-7001) steps per day, respectively. During a median (IQR) follow-up of 9.0 (8.0-9.9) years, the hazard ratios (HR) per SD for all-cause mortality were 0.82 (95% CI, 0.75-0.90) for MVPA time and 0.74 (95% CI, 0.69-0.80) for step counts. Greater MVPA time and step counts (top 3 quartiles vs bottom quartile) were associated with a longer period free from death: 2.22 (95% CI, 1.58-2.85) months and 2.36 (95% CI, 1.73-2.99) months at 9 years follow-up, respectively. The AUCs for all-cause mortality from MVPA time and step counts were similar: 0.55 (95% CI, 0.52-0.57) for both metrics. Similar associations of these 2 metrics with CVD were observed.

Conclusion and Relevance

Results of this study suggest that among females 62 years or older, MVPA time and step counts were qualitatively similar in their associations with all-cause mortality and CVD. Step count-based goals should be considered for future guidelines along with time-based goals, allowing for the accommodation of personal preferences.

Categorization of continuous covariates and complex regression models-friends or foes in intersectionality research

OBJECTIVES

To reduce health inequities, it is important to identify intersections in characteristics of individuals subject to privilege or disadvantage. Different proposals for that have recently been published. One approach (1) considers models specified with first- and all second-order effects and another (2) the stratification based on multiple covariates; both categorize continuous covariates. A simulation study was conducted in order to review both methods with regard to identification of intersections showing true differences, rate of false-positive results, and generalizability to independent data compared to an established approach (3) of backward variable elimination according to Bayesian information criterion (BE-BIC) combined with splines.

STUDY DESIGN AND SETTING

R software has been used to simulate the covariates age, sex, body mass index, education, and diabetes to examine their association with a continuous frailty score for osteoporosis using multiple linear regression. In setting 1, none of the covariates was associated with the frailty score, that is, only noise is present in the data. In setting 2, the covariates age, sex, and their interaction were associated with the frailty score, such that only females above 55 years formed an intersection associated with an increased frailty score. All approaches were compared under varying sample sizes (N = 200-3000) and signal-to-noise ratios (SNRs, 0.5-4) in 1000 replications. For model evaluation, bootstrap resampling was used. The models were fitted in internal learning data and then used to predict outcomes in the internal validation data. The mean squared error (MSE) was used for comparison and the frequency of false-positive findings calculated.

RESULTS

In setting 1, approaches 1 and 2 generated spurious effects in more than 90% of simulations across all sample sizes. In a smaller sample size, approach 3 (BE-BIC) selected 36.5% of the correct model, in larger sample size in 89.8% and always had a lower number of spurious effects. MSE in independent data was generally higher for approaches 1 and 2 when compared to 3. In setting 2, approach 1 selected most frequently the correct interaction but frequently showed spurious effects (>75%). Across all sample sizes and SNR, approach 3 generated least often spurious results and had lowest MSE in independent data.

CONCLUSION

Categorization of continuous covariates is detrimental to studies on intersectionality. Due to high and unrestricted model complexity, such approaches are prone to spurious effects and often lack interpretability. Approach 3 (BE-BIC) is considerably more robust against spurious findings, showed better generalizability to independent data, and can be used with most statistical software. For intersectionality research, we consider it most important to describe relevant differences between intersections and to avoid nonreproducible and spurious findings.

UCP2 polymorphisms, daily step count, and number of teeth associated with all-cause mortality risk in Sado City: A hospital-based cohort study

Objective

Uncoupling protein 2 (UCP2) is an ion/anion transporter in the mitochondrial inner membrane that plays a crucial role in immune response, regulation of oxidative stress, and cellular metabolism. UCP2 polymorphisms are linked to chronic inflammation, obesity, diabetes, heart disease, exercise efficiency, and longevity. Daily step count and number of teeth are modifiable factors that reduce mortality risk, although the role of UCP2 in this mechanism is unknown. This study aimed to assess the possible effects of UCP2 polymorphisms on the association between daily step count and number of teeth with all-cause mortality.

Methods

This study was conducted as a cohort project involving adult Japanese outpatients at Sado General Hospital (PROST). The final number of participants was 875 (mean age: 69 y). All-cause mortality during thirteen years (from June 2008 to August 2021) was recorded. The functional UCP2 genotypes rs659366 and rs660339 were identified using the Japonica Array®. Survival analyses were performed using multivariate Cox proportional hazard models.

Results

There were 161 deaths (mean observation period: 113 months). Age, sex, daily step count, and the number of teeth were significantly associated with mortality. In females, UCP2 polymorphisms were associated with mortality independent of other factors (rs659366 GA compared to GG + AA; HR = 2.033, p = 0.019, rs660339 C T compared to CC + TT; HR = 1.911, p = 0.029). Multivariate models, with and without UCP2 genotypes, yielded similar results. The interaction terms between UCP2 genotype and daily step count or number of teeth were not significantly associated with mortality.

Conclusion

The effects of UCP2 polymorphisms on the association between daily step count or the number of teeth and all-cause mortality were not statistically significant. In females, UCP2 polymorphisms were significantly associated with all-cause mortality. Our findings confirmed the importance of physical activity and oral health and suggested a role of UCP2 in mortality risk independently with those factors.

Effect of Meal-Timing on the Association of Unsaturated Fatty Acids with All-Cause and Cardiovascular Mortality among Adults: A Prospective Cohort Study with 10-Year Follow-Up

BACKGROUND

Conflicting results have been reported on the association of dietary unsaturated fatty acids (UFAs) with longevity and cardiovascular health. Most previous studies have focused only on the amount of UFAs consumed, not the timing of intake.

METHODS

This prospective cohort study used data from 30,136 adults aged 18 years and older. Intakes of UFAs by meal time and types were assessed by a 24-h dietary recall for two days. The covariate-adjusted survey-weighted Cox proportional hazards models were performed to evaluate the associations of dietary total unsaturated fatty acid (TUFA), polyunsaturated fatty acid (PUFA), and monounsaturated fatty acid (MUFA) intakes throughout the day and three meals with mortality.

RESULTS

During a median of 10.0 years of follow-up, 4510 total deaths occurred. All-cause mortality decreased with increasing intakes at dinner of TUFA (HR: 0.87 [0.77-0.98]), PUFA (HR: 0.81 [0.73-0.91]), and MUFA (HR: 0.88 [0.77-0.99]). With an increased intake of PUFA at dinner, CVD mortality showed a decreasing trend. However, the inverted L-shaped non-linear trend in all-cause mortality was found with increasing intake at breakfast of TUFA (HR: 1.35 [1.17-1.57], Q3 vs. Q1), PUFA (HR: 1.30 [1.13-1.50]), and MUFA (HR: 1.28 [1.13-1.45]). Meanwhile, increased breakfast intake of UFAs was associated with increased CVD and heart disease mortality.

CONCLUSIONS

Meal timing influences the association of UFAs with all-cause and CVD-related mortality.

Physical activity and exercise health benefits: cancer prevention, interception, and survival

Physical activity (PA) has an established role in the promotion of health and fitness and the prevention of disease. Expected overall benefits include reduction of all-cause morbidity and death, weight control, improved quality of life, improved bone health and decreased falls of elderly subjects, , deeper cognition, and reduced risk of depression, anxiety, and sleeplessness. Currently, PA is a mainstay in the management of cardiovascular diseases, metabolic syndrome, diabetes, and bone health. Recently, the perception of its role in primary and secondary prevention, interception, and treatment of cancer, however, is also gaining importance. Regular walking, the simplest type of PA, is associated with reduced all-cause and cardiovascular disease mortality, and a role in cancer prevention is of increasing interest. Furthermore, PA improves the quality of life of cancer patients, attenuating side effects of chemotherapy, decreasing sarcopenia, increasing fitness, and inhibiting the recurrence and progression of some cancer types. It promotes emotional and psychological benefits in patients, inducing positive changes. While mechanisms, effective levels and useful amount of PA practice are well established in cardiology, they are yet to be fully determined in oncology. Nevertheless, PA is recommended to reduce cancer risk in the general population, and it has been introduced in programs for the prevention of second cancers. In perspective, it will help as integrative therapy in cancer patients and for cancer survivors. The number of beneficial effects in the cancer continuum is highlighted in this review.

Estimating lead-attributable mortality burden by socioeconomic status in the USA

BACKGROUND

This study aimed to estimate population-level and state-level lead-attributable mortality burdens stratified by socioeconomic status (SES) class in the USA.

METHODS

Based on the National Health and Nutrition Examination Survey (NHANES), we constructed individual-level SES scores from income, employment, education and insurance data. We assessed the association between the blood lead levels (BLL) and all-cause mortality by Cox regression in the NHANES cohort (n = 31 311, 4467 deaths). With estimated hazard ratios (HR) and prevalences of medium (2-5 μg/dL) and high (≥ 5 μg/dL) BLL, we computed SES-stratified population-attributable fractions (PAFs) of all-cause mortality from lead exposure across 1999-2019. We additionally conducted a systematic review to estimate the lead-attributable mortality burden at state-level.

RESULTS

The HR for every 2-fold increase in the BLL decreased from 1.23 (1.10-1.38) for the lowest SES class to 1.05 (0.90-1.23) for the highest SES class. Across all SES quintiles, medium BLL exhibited a greater mortality burden. Individuals with lower SES had higher lead-attributable burdens, and such disparities haver persisted over the past two decades. In 2017-19, annually 67 000 (32 000-112 000) deaths in the USA were attributable to lead exposure, with 18 000 (2000-41 000) of these deaths occurring in the lowest SES class. Substantial disparities in the state-level mortality burden attributable to lead exposure were also highlighted.

CONCLUSIONS

These findings suggested that disparities in lead-attributable mortality burden persisted within US adults, due to heterogeneities in the effect sizes of lead exposure as well as in the BLL among different SES classes.

Association between single and mixed exposure to polycyclic aromatic hydrocarbons and biological aging

Background

Aging is one of the most important public health issues. Previous studies on the factors affecting aging focused on genetics and lifestyle, but the association between polycyclic aromatic hydrocarbons (PAHs) and aging is still unclear.

Methods

This study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2003-2010. A total of 8,100 participants was used to construct the biological age predictors by using recent advanced algorithms Klemera-Doubal method (KDM) and Mahalanobis distance. Two biological aging indexes, recorded as KDM-BA acceleration and PhenoAge acceleration, were used to investigate the relationship between single PAHs and biological age using a multiple linear regression analysis, and a weighted quantile sum (WQS) model was constructed to explore the mixed effects of PAHs on biological age. Finally, we constructed the restricted cubic spline (RCS) model to assess the non-linear relationship between PAHs and biological age.

Results

Exposure to PAHs was associated with PhenoAge acceleration. Each unit increase in the log10-transformed level of 1-naphthol, 2-naphthol, and 2-fluorene was associated with a 0.173 (95% CI: 0.085, 0.261), 0.310 (95% CI: 0.182, 0.438), and 0.454 (95% CI: 0.309, 0.598) -year increase in PhenoAge acceleration, respectively (all corrected P < 0.05). The urinary PAH mixture was relevant to KDM-BA acceleration (β = 0.13, 95% CI: 0, 0.26, P = 0.048) and PhenoAge acceleration (β = 0.59, 95% CI: 0.47, 0.70, P < 0.001), and 2-naphthol had the highest weight in the weighted quantile sum (WQS) regression. The RCS analyses showed a non-linear association between 2-naphthol and 2-fluorene with KDM-BA acceleration (all P < 0.05) in addition to a non-linear association between 1-naphthol, 2-naphthol, 3-fluorene, 2-fluorene, and 1-pyrene with PhenoAge acceleration (all P < 0.05).

Conclusion

Exposure to mixed PAHs is associated with increased aging, with 2-naphthol being a key component of PAHs associated with aging. This study has identified risk factors in terms of PAH components for aging.

DASH diet vs. DASH diet plus physical activity in older patients with type 2 diabetes and high blood pressure: A randomized clinical trial

BACKGROUND AND AIMS

To evaluate the effect of lifestyle modification by adopting a DASH diet, with and without physical activity guidance, on blood pressure, glycemic control, lipid profile, weight, and body composition in older patients with type 2 diabetes mellitus (T2DM) and hypertension.

METHODS AND RESULTS

For this randomized clinical trial, we recruited patients aged 60 years or older with T2DM and uncontrolled hypertension. One group (DASH) received only DASH dietary guidance, while the other group (DASHPED) received dietary guidance and encouragement to walk with a pedometer. Outcomes of interest were (1) blood pressure, (2) physical activity, (3) weight, body mass index (BMI), and body composition, and (4) biochemical variables. Measurements were taken at baseline and 16 weeks after the intervention. We included 35 patients in the analysis. At the end of the study, the DASHPED group had an mean increase in physical activity of 1721 steps/day. Both groups displayed significantly reduced weight, BMI, and waking diastolic pressures on ambulatory blood pressure monitoring after the intervention. A trend of reduced sleeping diastolic pressure was found in the DASHPED group. Changes in weight, BMI, muscle mass, body fat, waist-hip ratio, glycemic control, lipid profile, and insulin sensitivity did not differ between the groups.

CONCLUSION

There was no difference in outcomes between the group that only dieted and the group that also performed increased physical activity, despite a significant increase in exercise. This reinforces the importance of dietary changes in immediate blood pressure control.

Step count and multiple health outcomes: An umbrella review

OBJECTIVE

This study aimed to quantify the association between step count and multiple health outcomes in a healthy population.

METHODS

PubMed, Embase, Web of Science, and The Cochrane Library were systematically searched for systematic reviews and meta-analyses from inception to April 1, 2022. Literature screening, data extraction, and data analysis were performed in this umbrella review. The intervention factor was daily step counts measured based on devices. Multiple health outcomes included metabolic diseases, cardiovascular diseases, all-cause mortality, and other outcomes in the healthy population.

RESULTS

Twenty studies with 94 outcomes were identified in this umbrella review. The increase in daily step count contributed to a range of human health outcomes. Furthermore, the special population, different age groups, countries, and cohorts should be carefully considered. Negative correlation between step counts and the following outcomes: metabolic outcomes, cardiovascular diseases, all-cause mortality, postural balance, cognitive function, and mental health. However, there was no association between participation in the outdoor walking group and the improvement of systolic blood pressure and diastolic blood pressure. Analysis of the dose-response association between increasing daily step count and the risk of cardiovascular disease events and all-cause mortality showed a substantially linear relationship.

CONCLUSION

A wide range of health outcomes can benefit from the right number of steps.

A Novel, Wearable Inertial Measurement Unit for Stroke Survivors: Validity, Acceptability, and Usability

OBJECTIVE

To establish the concurrent validity, acceptability, and sensor optimization of a consumer-grade, wearable, multi-sensor system to capture quantity and quality metrics of mobility and upper limb movements in stroke survivors.

DESIGN

Single-session, cross-sectional.

SETTING

Clinical research laboratory.

PARTICIPANTS

Thirty chronic stroke survivors (age 57 (10) years; 33% female) with mild to severe motor impairments participated.

INTERVENTIONS

Not Applicable.

MAIN OUTCOME MEASURES

Participants donned 5 sensors and performed standardized assessments of mobility and upper limb (UL) movement. True/false, positive/negative time in active movement for the UL were calculated and compared to criterion-standards using an accuracy rate. Bland-Altman plots and linear regression models were used to establish concurrent validity of UL movement counts, step counts, and stance time symmetry of MiGo against established criterion-standard measures. Acceptability and sensor optimization were assessed through an end-user survey and decision matrix.

RESULTS

Mobility metrics showed excellent association with criterion-standards for step counts (video: r=0.988, P<.001, IMU: r=0.921, P<.001) and stance-time symmetry (r=0.722, P<.001). In the UL, movement counts showed excellent to good agreement (paretic: r=0.849, P<.001, nonparetic: r=0.672, P<.001). Accuracy of active movement time was 85.2% (paretic) and 88.0% (nonparetic) UL. Most participants (63.3%) had difficulty donning/doffing the sensors. Acceptability was high (4.2/5).

CONCLUSIONS

The sensors demonstrated excellent concurrent validity for mobility metrics and UL movements of stroke survivors. Acceptability of the system was high, but alternative wristbands should be considered.

Treatment adherence and the contemporary approach to treating type 2 diabetes mellitus

The rising burden of type 2 diabetes mellitus (T2D) poses a significant healthcare challenge on a global scale. The economic impact is also substantial and continually increasing. In Serbia, even though the prevalence is officially around 12 percent, nearly 40 percent of the adult population is estimated to be living with undiagnosed diabetes and more than half the population is obese or overweight. This review comprehensively addresses the present approach to treating T2D, emphasizing the critical role of treatment adherence. We review the various components of T2D treatment, underlining the significance of lifestyle modifications. The pros and cons of medications used in treatment are discussed and factors influencing adherence are analysed. A healthy lifestyle remains the foundation of the treatment, and if not sufficient, early pharmacotherapy is initiated. Medications have been developed to lower blood sugar levels with cardiorenal protection, however, due to their still high cost, metformin remains the drug of first choice for most patients. Adherence to the treatment regimen is often poor. Factors associated with this are diverse and often multiple in a particular patient. Poor adherence is associated with poor glycaemic control, increased risk of disease complications, higher cardiovascular risk, increased mortality, hospitalizations, and healthcare costs. In addition to reducing the complexity of drug therapy and better informing the patient, improved education and motivation could lead to greater adherence. Enhanced communication between the patient and the physician and reduced treatment costs could also have a positive impact. The review concludes that addressing factors affecting adherence can significantly improve T2D outcomes and reduce costs. Further research is needed to identify region-specific risk factors for poor adherence.

Effect of Gamification, Financial Incentives, or Both to Increase Physical Activity Among Patients at High Risk of Cardiovascular Events: The BE ACTIVE Randomized Controlled Trial

BACKGROUND

Physical activity is associated with a lower risk of major adverse cardiovascular events, but few individuals achieve guideline-recommended levels of physical activity. Strategies informed by behavioral economics increase physical activity, but their longer-term effectiveness is uncertain. We sought to determine the effect of behaviorally designed gamification, loss-framed financial incentives, or their combination on physical activity compared with attention control over 12-month intervention and 6-month postintervention follow-up periods.

METHODS

Between May 2019 and January 2024, participants with clinical atherosclerotic cardiovascular disease or a 10-year risk of myocardial infarction, stroke, or cardiovascular death of ≥7.5% by the Pooled Cohort equation were enrolled in a pragmatic randomized clinical trial. Participants received a wearable device to track daily steps, established a baseline, selected a step goal increase, and were randomly assigned to control (n=151), behaviorally designed gamification (n=304), loss-framed financial incentives (n=302), or gamification+financial incentives (n=305). The primary outcome of the trial was the change in mean daily steps from baseline through the 12-month intervention period.

RESULTS

A total of 1062 patients (mean±SD age, 67±8; 61% female; 31% non-White) were enrolled. Compared with control subjects, participants had significantly greater increases in mean daily steps from baseline during the 12-month intervention in the gamification arm (adjusted difference, 538.0 [95% CI, 186.2-889.9]; P=0.0027), financial incentives arm (adjusted difference, 491.8 [95% CI, 139.6-844.1]; P=0.0062), and gamification+financial incentives arm (adjusted difference, 868.0 [95% CI, 516.3-1219.7]; P<0.0001). During the 6-month follow-up, physical activity remained significantly greater in the gamification+financial incentives arm than in the control arm (adjusted difference, 576.2 [95% CI, 198.5-954]; P=0.0028), but it was not significantly greater in the gamification (adjusted difference, 459.8 [95% CI, 82.0-837.6]; P=0.0171) or financial incentives (adjusted difference, 327.9 [95% CI, -50.2 to 706]; P=0.09) arms after adjustment for multiple comparisons.

CONCLUSIONS

Behaviorally designed gamification, loss-framed financial incentives, and the combination of both increased physical activity compared with control over a 12-month intervention period, with the largest effect in gamification+financial incentives. These interventions could be a useful component of strategies to reduce cardiovascular risk in high-risk patients.

REGISTRATION

URL: https://clinicaltrials.gov; Unique Identifier: NCT03911141.

Cross-sectional associations between patterns and composition of upright and stepping events with physical function: insights from The Maastricht Study

INTRODUCTION

Age-related declines in physical functioning have significant implications for health in later life. Physical activity (PA) volume is associated with physical function, but the importance of the pattern in which PA is accumulated is unclear. This study investigates associations between accelerometer-determined daily PA patterns, including composition and temporal distribution (burstiness) of upright and stepping events, with physical function.

METHODS

Data was from participants who wore an activPAL3 accelerometer as part of The Maastricht Study. Exposures included a suite of metrics describing the composition and the temporal distribution (burstiness) of upright and sedentary behaviour. Physical function outcomes included the six-minute walk test (6MWT), timed chair-stand test (TCST), grip strength (GS), and SF-36 physical functioning sub-scale (SF-36pf). Multivariable linear regression models were used to assess associations, adjusting for covariates including overall PA volume (daily step count).

RESULTS

Participants(n = 6085) had 6 or 7 days of valid data. Upright and stepping event metrics were associated with physical function outcomes, even after adjusting PA volume. Higher sedentary burstiness was associated with better function (6MWT, TCST, and SF-36pf), as was duration and step volume of stepping events (6MWT, TCST, GS, and SF-36pf), step-weighted cadence (6MWT, TCST, and SF-36pf). Number of stepping events was associated with poorer function (6MWT, GS, and SF-36pf), as was upright event burstiness (SF-36pf). Associations varied according to sex.

CONCLUSION

Our study reveals that diverse patterns of physical activity accumulation exhibit distinct associations with various measures of physical function, irrespective of the overall volume. Subsequent investigations should employ longitudinal and experimental studies to examine how changing patterns of physical activity may affect physical function, and other health outcomes.

Sleeping more than 8 h: a silent factor contributing to decreased muscle mass in Chinese community-dwelling older adults

BACKGROUND

Muscle mass loss is an age-related process that can be exacerbated by lifestyle, environmental and other factors, but can be mitigated by good sleep. The objective of this study was to investigate the correlation between varying time lags of sleep duration and the decline in muscle mass among individuals aged 60 years or older by using real-world health monitoring data obtained from wearable devices and smart home health monitoring devices.

METHODS

This study included 86,037 observations from 2,869 participants in the Mobile Support System database. Missing data were supplemented by multiple imputation. The investigation utilized generalized estimating equations and restricted cubic spline curve to examine the relationship between sleep duration and low muscle mass. Various lag structures, including 0, 1, 2, 0-1, 0-2, and 1-2 months, were fitted, and the interaction effect of observation time with sleep duration was estimated for each lag structure. Additionally, subgroup analyses were conducted. The models were adjusted for various covariates, including gender, age, body mass index, footsteps, smoking status, drinking status, marital status, number of chronic diseases, number of medications, diabetes mellitus, hyperlipidemia, coronary artery disease, respiratory disease, and musculoskeletal disease and an interaction term between time and sleep duration.

RESULTS

The results of the generalized estimating equation showed a significant correlation (p < 0.001) between sleep duration of 8 h or more and low muscle mass in older adults, using 6-7 h of sleep as a reference. This effect was seen over time and prolonged sleep accumulated over multiple months had a greater effect on muscle mass loss than a single month. The effect of long sleep duration on muscle mass loss was significantly greater in females than in males and greater in the over-75 than in the under-75 age group. Restricted cubic spline plots showed a non-linear relationship between sleep duration and low muscle mass (p < 0.001).

CONCLUSIONS

This study found an association between sustained nighttime sleep of more than eight hours and decreased muscle mass in older adults, especially older women.

Mendelian randomisation and mediation analysis of self-reported walking pace and coronary artery disease

The aim of this study was to assess the causal relationship between habitual walking pace and cardiovascular disease risk using a Mendelian randomisation approach. We performed both one- and two-sample Mendelian randomisation analyses in a sample of 340,000 European ancestry participants from UK Biobank, applying a range of sensitivity analyses to assess pleiotropy and reverse causality. We used a latent variable framework throughout to model walking pace as a continuous exposure, despite being measured in discrete categories, which provided more robust and interpretable causal effect estimates. Using one-sample Mendelian randomisation, we estimated that a 1 mph (i.e., 1.6 kph) increase in self-reported habitual walking pace corresponds to a 63% (hazard ratio (HR) = 0.37, 95% confidence interval (CI), 0.25-0.55, P = 2.0 × 10-6) reduction in coronary artery disease risk. Using conditional analyses, we also estimated that the proportion of the total effect on coronary artery disease mediated through BMI was 45% (95% CI 16-70%). We further validated findings from UK Biobank using two-sample Mendelian randomisation with outcome data from the CARDIoGRAMplusC4D consortium. Our findings suggest that interventions that seek to encourage individuals to walk more briskly should lead to protective effects on cardiovascular disease risk.

Cross-sectional associations between temporal patterns and composition of upright and stepping events with physical function in midlife: Insights from the 1970 British Cohort Study

INTRODUCTION

Age-related decline in physical functioning has significant implications for health in later life but declines begin earlier in midlife. Physical activity (PA) volume is associated with physical function, but the importance of the pattern in which PA is accumulated is unclear. This study investigates associations between patterns of PA accumulation, including the composition, variation, and temporal distribution of upright and stepping events, with physical function in midlife.

METHODS

Participants (n = 4378) from the 1970 British Cohort Study wore an activPAL3 accelerometer on the thigh for 7 consecutive days. Exposure measures included a suite of metrics describing the frequency, duration, and composition of upright events, as well as the duration and volume (total steps) of stepping events. In addition, patterns of accumulation of upright and sedentary events were examined including how fragmented/transient they were (upright-to-sedentary transition probability [USTP]) and their burstiness (the tendency for events to be clustered together followed by longer interevent times). Physical function outcomes included grip strength (GS), balance, and SF-36 physical functioning subscale (SF-36pf). Cross-sectional analyses included multivariable linear regression models to assess associations, adjusting for covariates including overall PA volume (mean daily step count).

RESULTS

Higher upright event burstiness was associated with higher GS, and higher USTP was associated with lower GS. Duration and step volume of stepping events were positively associated with SF-36pf in females. Step-weighted cadence was positively associated with SF-36pf and balance. Contradictory findings were also present (e.g., more transient stepping events were associated with better GS) particularly for GS in males. Inconsistencies between sexes were observed across some associations.

CONCLUSION

Our study reveals that diverse patterns of PA accumulation exhibit distinct associations with various measures of physical function in midlife, irrespective of the overall volume. Contradictory findings and inconsistency between sexes warrant further investigation. Patterns of PA accumulation, in addition to volume, should be considered in future PA research. Longitudinal studies are required to determine whether a given volume of activity accumulated in different patterns, impacts associations between PA and health outcomes.

Association of objectively measured physical activity with incidence disability in older adults with/without social isolation

PURPOSE

This study aimed to investigate association between objectively measured physical activities with incidence disability in older adults with and without social isolation.

METHODS

This 5-year longitudinal observational study used a population-based study from a sub-cohort of the National Center for Geriatrics and Gerontology Study of Geriatric Syndrome. In Japan, Incident disability is defined as a new case of public insurance certification for long-term care. As participants, we enrolled 5,257 community-dwelling older adults aged ≥ 70 years. The Participants on whom incomplete baseline physical activity assessments were performed; who required long-term care; had a history of dementia, Parkinson's disease, stroke, or depression; who lacked independence in basic ADL; who had Mini-Mental State Examination scores; or who had missing measurements; were excluded. Thus, 2,071 participants were included.

RESULTS

Of the participants, 1,183 non-socially isolated participants had 151 (4.3%) cases of disability, while socially isolated participants had 150 (13%) cases. Cox proportional-hazards regression analysis presented the adjusted hazard ratio (HR) and 95% confidence interval (95%CI) of daily steps and low-intensity and moderate-to-vigorous physical activities-0.62(0.43-0.89), 0.84(0.60-1.18), 0.62(0.43-0.89) in participants with social isolation, and 0.58(0.40-0.85), 0.86(0.60-1.24), 0.70(0.49-1.01) in those with social isolation.

CONCLUSIONS

Daily steps were significantly associated with a decreased risk of incidence disability, regardless of social isolation. These results suggest the greater importance of daily physical activity than its specific intensity in socially isolated older adults.

Lifestyle Elements for Improving Mental and Physical Health in Japanese University Students: Subjective Sleep Quality is a Common Key Factor

This study aimed to reveal the key lifestyle elements that improve physical and mental health in university students by focusing on physical activity, nutrition, and sleep. This cross-sectional study was conducted between October 2021 and December 2021. The participants were 290 first-year students (mean age, 18.63 ± .63 years; age range, 18 to 23; 198 female). The outcomes were daily step counts measured using accelerometers, dietary intake by nutrient category, sleep duration, subjective sleep quality, exercise frequency and duration by exercise type, screen time, depression level, and subjective fatigue by body part. Depression and subjective eye fatigue represent mental and physical health outcomes. Subjective sleep quality predicted depression (β = -1.22, P < .001) and eye fatigue (β = -.23, P < .01) in the path analysis. Participants with higher subjective sleep quality performed more frequent aerobic exercise (P < .01), longer session times of physical relaxation exercise (P < .05), and shorter screen time (P < .05). Subjective sleep quality could be a key factor for high mental and physical health. Furthermore, performing aerobic and relaxation exercises and reducing screen time are important for improving the subjective sleep quality.

Physical Activity Using a Wearable Device as an Alternative to Performance Status in Patients With Advanced Lung Cancer

Importance

The Eastern Cooperative Oncology Group Performance Status (ECOG PS) is extensively used to guide treatment decisions in patients with advanced lung cancer. However, its assessment is subjective, potentially leading to discordance among observers.

Objective

To investigate the association between measured physical activity and ECOG PS, as well as the potential prognostic value of physical activity measurements in patients with advanced lung cancer.

Design, Setting, and Participants

This single-institution, prospective observational study enrolled 119 patients with advanced lung cancer scheduled to receive systemic therapy as outpatients at Matsusaka Municipal Hospital in Mie, Japan. Participants wore the wearable device amuelink (Sony) for up to 14 days to measure physical activity, including metabolic equivalent tasks, distance walked, and number of steps taken. ECOG PS was assessed at enrollment, which took place from December 2021 to August 2022.

Main Outcomes And Measures

The primary end point was estimating the area under the curve (AUC) for classification into ECOG PS of 2 or higher using physical activity measurements. An analysis of the association with survival was also conducted.

Results

Among the 119 patients (median [range] age, 72 (32-88) years; 71 [59.7%] male), mean distance walked (MDW) had the highest diagnostic value for classifying an ECOG PS of 2 or greater, with an AUC of 0.818 (95% CI, 0.703-0.934). Moreover, MDW was also associated with 6-month survival, with an AUC of 0.806 (95% CI, 0.694-0.918). Survival curves significantly diverged based on the MDW threshold, indicating a potential association with survival outcome (hazard ratio, 0.17; 95% CI, 0.05-0.57).

Conclusions and Relevance

The cohort study suggests that MDW, as measured by a wearable device, was associated with ECOG PS and may serve as a predictor of health status alongside ECOG PS categories. It demonstrates the potential of objectively measured physical activity in complementing subjective ECOG PS assessments in patients with advanced lung cancer. Further research is needed to confirm the prognostic value of physical activity measurements.

Association between daily step counts and healthy life years: a national cross-sectional study in Japan

BACKGROUND

Despite accumulating evidence concerning the association between daily step counts and mortality or disease risks, it is unclear whether daily step counts are associated with healthy life years.

METHODS

We used the combined dataset of the Comprehensive Survey of Living Conditions and the National Health and Nutrition Survey conducted for a randomly sampled general population in Japan, 2019. Daily step counts were measured for 4957 adult participants. The associations of daily step counts with activity limitations in daily living and self-assessed health were evaluated using a multivariable logistic regression model. The bootstrap method was employed to mitigate uncertainties in estimating the threshold of daily step counts.

RESULTS

The median age was 60 (44-71) years, and 2592 (52.3%) were female. The median daily step counts were 5650 (3332-8452). The adjusted OR of activity limitations in daily living for the adjacent daily step counts was 0.27 (95% CI 0.26 to 0.27) for all ages and 0.25 (95% CI 0.25 to 0.26) for older adults at the lowest, with the thresholds of significant association at 9000 step counts. The OR of self-assessed unhealthy status was 0.45 (95% CI 0.44 to 0.46) for all ages and 0.42 (95% CI 0.41 to 0.43) for older adults at the lowest, with the thresholds at 11 000 step counts.

CONCLUSION

Daily step counts were significantly associated with activity limitations in daily living and self-assessed health as determinants of healthy life years, up to 9000 and 11 000 step counts, respectively. These results suggest a target of daily step counts to prolong healthy life years within health initiatives.

High serum copper as a risk factor of all-cause and cause-specific mortality among US adults, NHANES 2011-2014

Background

Several studies have shown that serum copper levels are related to coronary heart disease, diabetes, and cancer. However, the association of serum copper levels with all-cause, cause-specific [including cardiovascular disease (CVD) and cancer] mortality remains unclear.

Objectives

This study aimed to prospectively examine the association of copper exposure with all-cause, CVD, and cancer mortality among US adults.

Methods

The data for this analysis was obtained from the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014. Mortality from all-causes, CVD, and cancer mortality was linked to US National Death Index mortality data. Cox regression models were used to estimate the association between serum copper levels and all-cause, CVD, and cancer mortality.

Results

A total of 2,863 adults were included in the main study. During the mean follow-up time of 81.2 months, 236 deaths were documented, including 68 deaths from cardiovascular disease and 57 deaths from cancer. The weighted mean overall serum copper levels was 117.2 ug/L. After adjusting for all of the covariates, compared with participants with low (1st tertile, <103 μg/L)/medium (2st tertile, 103-124 μg/L) serum copper levels, participants with high serum copper levels (3rd tertile, ≥124 μg/L) had a 1.75-fold (95% CI, 1.05-2.92)/1.78-fold (1.19,2.69) increase in all-cause mortality, a 2.35-fold (95% CI, 1.04-5.31)/3.84-fold (2.09,7.05) increase in CVD mortality and a 0.97-fold (95% CI, 0.28-3.29)/0.86-fold (0.34,2.13) increase in cancer mortality. In addition, there was a linear dose-response association between serum copper concentration with all-cause and CVD mortality (P for nonlinear > 0.05).

Conclusions

This prospective study found that serum copper concentrations were linearly associated with all-cause and CVD mortality in US adults. High serum copper levels is a risk factor for all-cause and CVD mortality.

Real-world walking behaviors are associated with early-stage heart failure: a Project Baseline Health Study

BACKGROUND

Data collected via wearables may complement in-clinic assessments to monitor subclinical heart failure (HF).

OBJECTIVES

Evaluate the association of sensor-based digital walking measures with HF stage and characterize their correlation with in-clinic measures of physical performance, cardiac function and participant reported outcomes (PROs) in individuals with early HF.

METHODS

The analyzable cohort included participants from the Project Baseline Health Study (PBHS) with HF stage 0, A, or B, or adaptive remodeling phenotype (without risk factors but with mild echocardiographic change, termed RF-/ECHO+) (based on available first-visit in-clinic test and echocardiogram results) and with sufficient sensor data. We computed daily values per participant for 18 digital walking measures, comparing HF subgroups vs stage 0 using multinomial logistic regression and characterizing associations with in-clinic measures and PROs with Spearman's correlation coefficients, adjusting all analyses for confounders.

RESULTS

In the analyzable cohort (N=1265; 50.6% of the PBHS cohort), one standard deviation decreases in 17/18 walking measures were associated with greater likelihood for stage-B HF (multivariable-adjusted odds ratios [ORs] vs stage 0 ranging from 1.18-2.10), or A (ORs vs stage 0, 1.07-1.45), and lower likelihood for RF-/ECHO+ (ORs vs stage 0, 0.80-0.93). Peak 30-minute pace demonstrated the strongest associations with stage B (OR vs stage 0=2.10; 95% CI:1.74-2.53) and A (OR vs stage 0=1.43; 95% CI:1.23-1.66). Decreases in 13/18 measures were associated with greater likelihood for stage-B HF vs stage A. Strength of correlation with physical performance tests, echocardiographic cardiac-remodeling and dysfunction indices and PROs was greatest in stage B, then A, and lowest for 0.

CONCLUSIONS

Digital measures of walking captured by wearable sensors could complement clinic-based testing to identify and monitor pre-symptomatic HF.

Exploring Physical Activity Levels in Patients with Cardiovascular Disease-A Preliminary Study

Increased physical activity may prevent disease onset and severity in individuals with cardiovascular disease. However, studies evaluating physical activity in people with cardiovascular disease are limited. This prospective observational study aimed to objectively assess the level of physical activity in patients with cardiovascular disease and determine the actual extent of physical activity in their daily lives. Participants aged 20 years or older with cardiovascular disease at a cardiology clinic were included. Physical activity was measured using an activity meter with a three-axis acceleration sensor. Overall, 58 patients were included in the study. Household activities were found to be more frequent sources of physical activity. The step count was related to age and housework, while total physical activity and household activity were related to age and work. Locomotive activity was related to sex and housework. Total physical and household activities tended to decrease with age. These findings indicate the influence of work and household chores on physical activity and suggest that physical activity may be underestimated if household activity is not also assessed. These fundamental findings may provide clinical evidence to underpin physical activity for patients with cardiovascular disease.

Step cadence as a novel objective postoperative recovery metric in children who undergo laparoscopic appendectomy

BACKGROUND

Daily step counts from consumer wearable devices have been used to objectively assess postsurgical recovery in children. However, step cadence, defined as steps taken per minute, may be a more specific measure of physiologic status. The purpose of this study is to define objective normative physical activity recovery trajectories after laparoscopic appendectomy using this novel metric. We hypothesized that patients would have a progressive increase in peak cadence until reaching a plateau representing baseline status, and this would occur earlier for simple compared with complicated appendicitis.

METHODS

Children aged 3 to 18 years were enrolled after laparoscopic appendectomy for simple or complicated appendicitis between March 2019 and December 2022 at a tertiary children's hospital. Participants wore a Fitbit for 21 postoperative days. The peak 1-minute cadence and peak 30-minute cadence were determined each postoperative day. Piecewise linear regression was conducted to generate normative peak step cadence recovery trajectories for simple and complicated appendicitis.

RESULTS

A total of 147 children met criteria (53.7% complicated appendicitis). Patients with simple appendicitis reached plateau postoperative day 10 at a mean peak 1-minute cadence of 111 steps/minute and a mean peak 30-minute cadence of 77 steps/minute. The complicated appendicitis recovery trajectory reached a plateau postoperative day 13 at a mean peak 1-minute cadence of 106 steps/minute and postoperative day 15 at a mean peak 30-minute cadence of 75 steps/minute.

CONCLUSION

Using step cadence, we defined procedure-specific normative peak cadence recovery trajectories after laparoscopic appendectomy. This can empower clinicians to set data-driven expectations for recovery after surgery and establish the groundwork for consumer wearable devices as a post-discharge remote monitoring tool.

Free-living ambulatory physical activity and cognitive function in multiple sclerosis: the significance of step rate vs. step volume

BACKGROUND

Physical activity (PA) represents a promising behavioral approach for managing cognitive dysfunction in multiple sclerosis (MS). However, there is a lack of information on the pattern of free-living PA intensity (e.g., step rate) and its unique association with cognition. Such information is essential for informing clinical trials in MS.

OBJECTIVE

We examined associations among PA volume and intensity with cognitive function in persons with MS, and intensity was derived from steps-based metrics (peak 30-min cadence [Peak-30CAD], and time spent in incremental cadence bands).

METHODS

We included data from 147 persons with MS who underwent assessments of cognitive function (via Brief International Cognitive Assessment in MS) and wore an ActiGraph GT3X + accelerometer for 7 days. We performed bivariate and partial correlations and regression analyses examining associations among PA metrics and cognitive outcomes.

RESULTS

Higher Peak-30CAD was significantly associated with better performance in cognitive processing speed and verbal learning and memory (rs = 0.19-0.38), and the associations remained significant when controlling for daily steps, age, sex, and years of education (p < 0.05). By comparison, daily steps was only correlated with cognitive processing speed (rs = 0.26), and the association was non-significant when controlling for Peak-30CAD and covariates. There were stronger correlations among time spent in higher intensity cadence bands with cognitive performance (rs = 0.18-0.38).

CONCLUSION

Our results highlight the important role of PA intensity for cognition in MS, and may inform future development of focal PA interventions that focusing on step rate patterns for improving cognition in persons with MS.

Standardizing Physical Activity Monitoring in Patients With Degenerative Lumbar Disorders

BACKGROUND AND OBJECTIVES

Degenerative thoracolumbar disorders (DTDs) typically cause pain and functional impairment. However, little is known regarding the DTD impact on patient's real-life physical activity. The objective of this study is to validate a wearable measure of physical activity monitoring in patients with DTD and to create gender- and sex-specific performance thresholds that are standardized to the mean of a control population.

METHODS

A commercially available smartwatch (Apple Watch) was used to monitor preoperative physical activity in patients undergoing surgery for DTD. Mean preoperative physical activity 2 weeks before the scheduled surgery was expressed as raw step count. Standardized z-scores were referenced to age- and sex-specific values of a control population from a large public database. Step counts were assessed for convergent validity with established patient-reported outcome measures, and impairment in activity was stratified into performance groups based on z-score cutoff values.

RESULTS

Sixty-five patients (62% female) with a mean (±SD) age of 63.8 (±12.8) years had a mean preoperative daily step count of 5556 (±3978). Physical activity showed significant correlation with patient-reported outcome measures, including Oswestry disability index (r = -0.26, 95% CI: -0.47-0.01), 36-Item Short Form Survey Physical Component Summary score (r = 0.30, 95% CI: 0.06-0.51), and Patient-Reported Outcomes Measurement Information System Physical Function (r = 0.49, 95% CI: 0.27-0.65). "No," "Mild," "moderate," and "severe impairment" in activity performance were defined as corresponding z-scores of >0, 0 to -0.99, -1 to -1.99, and ≤-2, accounting for 22%, 34%, 40%, and 5% of the study population. Each one-step category increase in activity impairment resulted in increased subjective disability as measured by the Oswestry Disability Index, 36-Item Short Form Survey Physical Component Summary, and Patient-Reported Outcomes Measurement Information System Physical Function (all P -values <.05).

CONCLUSION

We establish the first wearable objective measure of real-life physical activity for patients with DTD, with the first age- and sex-adjusted standard scores to enable clinicians and researchers to set treatment goals and directly compare activity levels between individual patients with DTD and normal controls.