Cardiometabolic thresholds for peak 30-min cadence and steps/day

mHealth intervention delivered in general practice to increase physical activity and reduce sedentary behaviour of patients with prediabetes and type 2 diabetes (ENERGISED): statistical analysis plan

BACKGROUND

Type 2 diabetes and prediabetes represent significant global health challenges, with physical activity (PA) being essential for disease management and prevention. Despite the well-documented benefits, many individuals with (pre)diabetes remain insufficiently active. General practitioners (GP) provide an accessible platform for delivering interventions; however, integrating PA interventions into routine care is hindered by resource constraints.

OBJECTIVES

The ENERGISED trial aims to address these barriers through an innovative GP-initiated mHealth intervention combining wearable technology and just-in-time adaptive interventions.

METHODS

The ENERGISED trial is a pragmatic, 12-month, multicentre, randomised controlled trial, assessing a GP-initiated mHealth intervention to increase PA and reduce sedentary behaviour in patients with type 2 diabetes and prediabetes. The primary outcome is daily step count, assessed via wrist-worn accelerometry. The primary analysis follows the intention-to-treat principle, using mixed models for repeated measures. Missing data will be handled under the missing-at-random assumption, with sensitivity analyses exploring robustness through reference-based multiple imputation. The trial incorporates the estimand framework to provide transparent and structured treatment effect estimation.

DISCUSSION

This statistical analysis plan outlines a robust approach to addressing participant non-adherence, protocol violations, and missing data. By adopting the estimand framework and pre-specified sensitivity analyses, the plan ensures methodological rigour while enhancing the interpretability and applicability of results.

CONCLUSIONS

The ENERGISED trial leverages innovative mHealth strategies within primary care to promote PA in individuals with (pre)diabetes. The pre-specified statistical framework provides a comprehensive guide for analysing trial data and contributes to advancing best practices in behavioural intervention trials for public health.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05351359 . Registered on April 28, 2022.

Psychometric properties of free-living step-based metrics (daily steps and peak cadence) in multiple sclerosis

OBJECTIVE

We examined the reliability, precision, and clinically detectable change of step-based metrics (daily steps, peak 30-minute cadence [Peak-30CAD], and peak 1-minute cadence [Peak-1CAD]) over six months in the absence of intervention, and evaluated the construct validity through correlations with laboratory-assessed walking and gait performance among persons with multiple sclerosis (MS).

DESIGN

Cross-sectional study.

SETTING

University-based laboratory.

PARTICIPANTS

Seventy-eight ambulatory adults (18-64 years) with MS.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Free-living physical activity (via ActiGraph GT3X accelerometer), the Timed 25-Foot Walk, 6-Minute Walk, gait assessment (gait velocity, step length and time), and disability status (the 12-item MS Walking Scale, Patient Determined Disease Steps, and Self-Report Expanded Disability Status Scale) were measured before and after six months without any intervention.

RESULTS

Step-based metrics were stable with no significant changes across time (p>0.05) and demonstrated good test-retest reliability (ICCs: 0.80-0.85) and acceptable precision (SEM%s:14.4%∼24.3%). The MDC95 values for Peak-30CAD, Peak-1CAD, and daily steps were 25.6 steps/min, 31.0 steps/min, and 2909.2 steps/day, respectively. There were consistent, strong associations between peak cadence with walking tests, gait parameters, and disability status at both time points (|rs|=0.52-0.79), even after controlling for daily steps (|prs|=0.25-0.58; p<0.05).

CONCLUSION

Walking represents an important clinical endpoint in people with MS, yet it is often measured in controlled settings using performance-based tests that might not reflect real-world status. Our findings support step-based metrics via accelerometry as reliable and valid measures of free-living ambulatory performance, and may inform the inclusion of these metrics in clinical trials among people with MS.

Simple step counting captures comparable health information to complex accelerometer measurements

BACKGROUND

Physical activity guidelines recommend accumulating moderate-to-vigorous physical activity but interpreting and monitoring these recommendations remains challenging. Although step-based metrics from wearable devices offer a simpler approach, their relationship with health outcomes requires validation against established accelerometer measurements.

OBJECTIVES

To evaluate how effectively step-based metrics capture health-related information from accelerometer data and determine optimal step cadence and intensity thresholds associated with cardiometabolic health in middle-aged adults.

METHODS

Cross-sectional data from 4172 participants (aged 50-64 years) in the Swedish CArdioPulmonary bioImage Study (SCAPIS) were analyzed. Physical activity was measured using ActiGraph accelerometers, collecting both step metrics (daily steps and cadence) and full accelerometer data. Both cardiorespiratory fitness, estimated using a submaximal cycle ergometer test, and cardiometabolic health, assessed using a composite score of waist circumference, blood pressure, lipids, and glycated hemoglobin (HbA1c), were considered outcomes. Associations between physical activity and outcomes were examined using linear regression and partial least squares analysis.

RESULTS

Step counting metrics retained 88% of the health-related information from full accelerometer data. The optimal accelerometer intensity associated with cardiometabolic health was around four metabolic equivalents of tasks (METs). A step cadence of 80 steps/min, rather than the commonly used 100 steps/min, appeared more relevant for capturing moderate-intensity activity. Combining step and accelerometer data provided additional explanatory power for cardiometabolic health.

CONCLUSION

Step data capture most of the health-related information from accelerometer-measured physical activity in middle-aged adults. These findings support the use of step-based metrics for assessing and promoting physical activity while suggesting a need for recalibration of intensity thresholds in free-living conditions.

Associations of physical activity volume and intensity with depression symptoms among US adults

Background

This study aimed to investigate the associations of physical activity (PA) volume and intensity with the risk of depression symptoms.

Methods

The data utilized in this study came from the 2011-2014 National Health and Nutrition Examination Survey. PA was measured using a triaxial accelerometer and calculated using the Monitor-Independent Movement Summary (MIMS), MIMS units are a novel metric derived from wrist-worn accelerometer data, representing the intensity of PA for each minute across the entire monitoring period. PA volume and intensity were expressed by the average of daily accumulated MIMS (Daily MIMS) and peak 30-min MIMS (Peak-30MIMS; Peak 30-min intensity), respectively. Depression symptoms were defined as Patient Health Questionnaire-9 score ≥10. Weighted logistic regression and restricted cubic splines were used to evaluate the associations between PA metrics and depression symptoms.

Results

After adjusting for all covariates, higher Daily MIMS and Peak-30MIMS were associated with lower depression risk. Each additional 1,000 units in Daily MIMS and 1-unit in Peak-30MIMS were associated with a 5% [Odds ratio (OR) = 0.95, 95% confidence interval (95% CI): 0.94, 0.98] and 2% (OR = 0.98, 95% CI: 0.97, 0.99) reduction in depression risk, respectively. When including both MIMS metrics in the same model, the association between Peak-30MIMS and depression remained significant (p = 0.02), whereas Daily MIMS did not (p = 0.60). The spline analysis indicated a monotonic decrease in the OR with higher Daily MIMS values (P for non-linear = 0.21). An initial increase followed by a decrease in OR was observed with rising Peak-30MIMS values (P for non-linear <0.01).

Conclusion

Our findings indicate that higher PA volume and intensity are associated with lower depression risk. The association between PA volume and reduced depression risk was negated after adjusting for PA intensity in US adults.

Associations of daily steps and step intensity with peripheral arterial disease in Chinese community-dwelling older women

AIMS

This study aims to investigate the associations of objectively measured daily steps and step intensity with peripheral arterial disease (PAD) in Chinese community-dwelling older women.

METHODS

Cross-sectional data were derived from the baseline survey of the Physical Activity and Health in Older Women Study. Peripheral arterial disease was evaluated through ankle-brachial index (ABI), ABI ≤ 0.9 was defined as cut-off point. Daily steps and step intensity were measured via tri-axial accelerometers. Multivariate logistic regression was used to investigate associations of step variable with PAD. Receiver operating characteristic (ROC) analysis was applied to identify an optimal cut-off value for step variables to screen PAD.

RESULTS

After adjusting for confounding factors, it was found that daily steps was not independently associated with PAD, and brisk steps, peak 30 as well as peak 60, were significantly associated with PAD, with ORs of 0.68 (0.50-0.93), 0.71 (0.52-0.96) and 0.60 (0.40-0.90), respectively. The optimal cut-off values for brisk steps, peak 30 and 60 screening PAD were 952.3 steps, 76.7 steps/min and 51.8 steps/min, respectively.

CONCLUSIONS

Step intensity rather than daily steps was independently associated with PAD in Chinese community-dwelling older women. Increasing the intensity during walking may be a viable strategy to reduce the risk of PAD in self-care and cardiovascular nursing.

Daily and Peak Monitor Independent Movement Summary (MIMS) Values Associated With Metabolic Syndrome: NHANES 2011-12 and 2013-14

The U.S. National Health and Nutrition Examination Survey (NHANES) physical activity monitor datasets for 2011-12 and 2013-14 were released in late 2020. To date, there has been limited interpretation of these nationally representative wrist-worn accelerometer data (summarized and reported in Monitor Independent Movement Summary [MIMS] units) and their relationships with health-related outcomes. This study examined the associations between free-living DailyMIMS (volume), Peak 1MIMS and Peak 30MIMS (intensity), and risk of Metabolic Syndrome (MetS). Data from adults (N=3787; 18-80+ years) in the 2011-12 and 2013-14 NHANES cycles with health examination and accelerometry data were included. Accelerometer data were processed into Peak 1MIMS and Peak 30MIMS (MIMS/min), and DailyMIMS (MIMS/day). Design-based generalized linear and logistic regressions, and a sample-weighted decision tree, were used to examine associations between MIMS variables and MetS risk factors. Lower Peak 1MIMS, Peak 30MIMS, and DailyMIMS were observed for every one-unit increase in the number of risk factors -3.9 [95% CI: -4.3, -3.4] and -2.3 [-2.6, -2.1] MIMS/min, (-672.1 [-772.7, -571.5] MIMS/day, respectively, all p< 0.001). The Decision Tree classified individuals ≥ 46.5 years with a DailyMIMS ≥ 12 245 MIMS/day and a Peak 30MIMS < 45.1 MIMS/min as having MetS (≥ 3 risk factors). Individuals < 46.5 years with a Peak 1MIMS ≥ 62.9 MIMS/min were classified with 0 risk factors. Higher DailyMIMS and PeakMIMS were associated with an absence of MetS risk factors, with a progressive decline as the number of risk factors increased. These findings may be considered as preliminary benchmarks for DailyMIMS and PeakMIMS associated with cardiometabolic risk.

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 Peak Cadence in Multiple Sclerosis: A New Measure of Real-World Walking?

BACKGROUND

Physical function and walking performance have become important outcomes in clinical trials and rehabilitation involving persons with multiple sclerosis (MS). However, assessments conducted in controlled settings may not reflect real-world capacity and movement in a natural environment. Peak cadence via accelerometry might represent a novel measure of walking intensity and prolonged natural effort under free-living conditions.

OBJECTIVE

We compared peak 30-minute cadence, peak 1-minute cadence, and time spent in incremental cadence bands between persons with MS and healthy controls, and examined the associations between peak cadence and laboratory-assessed physical function and walking performance.

METHODS

Participants (147 MS and 54 healthy controls) completed questionnaires on disability status and self-reported physical activity, underwent the Short Physical Performance Battery, Timed 25-Foot Walk, Timed Up and Go, and 6-Minute Walk, and wore an accelerometer for 7 days. We performed independent samples t-tests and Spearman bivariate and partial correlations adjusting for daily steps.

RESULTS

The MS sample demonstrated lower physical function and walking performance scores, daily steps, and peak cadence (P < .001), and spent less time in purposeful steps and slow-to-brisk walking (40-119 steps/minutes), but accumulated more incidental movement (1-19 steps/minutes) than healthy controls. The associations between peak cadence and performance outcomes were strong in MS (|rs| = 0.59-0.68) and remained significant after controlling for daily steps (|prs| = 0.22-0.44), P-values < .01. Peak cadence was inversely correlated with age and disability, regardless of daily steps (P < .01).

CONCLUSIONS

Our findings provide preliminary evidence for the potential use of peak cadence with step-based metrics for comprehensively evaluating free-living walking performance in MS.

Four-Year Increase in Step Cadence Is Associated with Improved Cardiometabolic Health in People with a History of Prediabetes

PURPOSE

To investigate associations between 4-yr change in step cadence and markers of cardiometabolic health in people with a history of prediabetes and to explore whether these associations are modified by demographic factors.

METHODS

In this prospective cohort study, adults, with a history of prediabetes, were assessed for markers of cardiometabolic health (body mass index, waist circumference, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], triglycerides, and glycated hemoglobin A1c [HbA1c]), and free-living stepping activity (activPAL3™) at baseline, 1 yr, and 4 yr. Brisk steps per day were defined as the number of steps accumulated at ≥100 steps per minute and slow steps per day as those accumulated at <100 steps per minute; the mean peak stepping cadence during the most active 10 minutes of the day was also derived. Generalized estimating equations examined associations between 4-yr change in step cadence and change in cardiometabolic risk factors, with interactions by sex and ethnicity.

RESULTS

Seven hundred ninety-four participants were included (age, 59.8 ± 8.9 yr; 48.7% women; 27.1% ethnic minority; total steps per day, 8445 ± 3364; brisk steps per day, 4794 ± 2865; peak 10-min step cadence, 128 ± 10 steps per minute). Beneficial associations were observed between change in brisk steps per day and change in body mass index, waist circumference, HDL-C, and HbA1c. Similar associations were found between peak 10-min step cadence and HDL-C and waist circumference. Interactions by ethnicity revealed change in brisk steps per day and change in peak 10-min step cadence had a stronger association with HbA1c in White Europeans, whereas associations between change in 10-min peak step cadence with measures of adiposity were stronger in South Asians.

CONCLUSIONS

Change in the number of daily steps accumulated at a brisk pace was associated with beneficial change in adiposity, HDL-C, and HbA1c; however, potential benefits may be dependent on ethnicity for outcomes related to HbA1c and adiposity.

How are different clusters of physical activity, sedentary, sleep, smoking, alcohol, and dietary behaviors associated with cardiometabolic health in older adults? A cross-sectional latent class analysis

BACKGROUND

Studies to date that investigate combined impacts of health behaviors, have rarely examined device-based movement behaviors alongside other health behaviors, such as smoking, alcohol, and sleep, on cardiometabolic health markers. The aim of this study was to identify distinct classes based on device-assessed movement behaviors (prolonged sitting, standing, stepping, and sleeping) and self-reported health behaviors (diet quality, alcohol consumption, and smoking status), and assess associations with cardiometabolic health markers in older adults.

METHODS

The present study is a cross-sectional secondary analysis of data from the Mitchelstown Cohort Rescreen (MCR) Study (2015-2017). In total, 1,378 older adults (aged 55-74 years) participated in the study, of whom 355 with valid activPAL3 Micro data were included in the analytical sample. Seven health behaviors (prolonged sitting, standing, stepping, sleep, diet quality, alcohol consumption, and smoking status) were included in a latent class analysis to identify groups of participants based on their distinct health behaviors. One-class through to six-class solutions were obtained and the best fit solution (i.e., optimal number of classes) was identified using a combination of best fit statistics (e.g., log likelihood, Akaike's information criteria) and interpretability of classes. Linear regression models were used to test associations of the derived classes with cardiometabolic health markers, including body mass index, body fat, fat mass, fat-free mass, glycated hemoglobin, fasting glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, systolic and diastolic blood pressure.

RESULTS

In total, 355 participants (89% of participants who were given the activPAL3 Micro) were included in the latent class analysis. Mean participant ages was 64.7 years and 45% were female. Two distinct classes were identified: "Healthy time-users" and "Unhealthy time-users". These groups differed in their movement behaviors, including physical activity, prolonged sitting, and sleep. However, smoking, nutrition, and alcohol intake habits among both groups were similar. Overall, no clear associations were observed between the derived classes and cardiometabolic risk markers.

DISCUSSION

Despite having similar cardiometabolic health, two distinct clusters were identified, with differences in key behaviors such as prolonged sitting, stepping, and sleeping. This is suggestive of a complex interplay between many lifestyle behaviors, whereby one specific behavior alone cannot determine an individual's health status. Improving the identification of the relation of multiple risk factors with health is imperative, so that effective and targeted interventions for improving health in older adults can be designed and implemented.

Dose-Response Association Between Physical Activity (Daily MIMS, Peak 30-Minute MIMS) and Cognitive Function Among Older Adults: NHANES 2011-2014

BACKGROUND

The purpose of this study was to determine the dose-response association between habitual physical activity (PA) and cognitive function using a nationally representative data set of U.S. older adults aged ≥60 years.

METHODS

We used data from the 2011-2014 National Health and Nutrition Examination Survey (n = 2 441, mean [SE] age: 69.1 [0.2] years, 54.7% females). Cognitive function was assessed using the digit symbol substitution test (DSST) and animal fluency test (AFT). Habitual PA was collected using a triaxial accelerometer worn on participants' nondominant wrist. PA was expressed as 2 metrics using monitor-independent movement summary (MIMS) units: the average of Daily MIMS (MIMS/day) and peak 30-minute MIMS (Peak-30MIMS; the average of the highest 30 MIMS min/d). Sample weight-adjusted multivariable linear regression was performed to determine the relationship between each cognitive score and MIMS metric while adjusting for covariates.

RESULTS

After controlling for covariates, for each 1 000-unit increase in Daily MIMS, DSST score increased (β-coefficient [95% CIs]) by 0.67 (0.40, 0.93), whereas AFT score increased by 0.13 (0.04, 0.22); for each 1-unit increase in Peak-30MIMS, DSST score increased by 0.56 (0.42, 0.70), whereas AFT score increased by 0.10 (0.05, 0.15), all p < .001. When including both MIMS metrics in a single model, the association between Peak-30MIMS and cognitive scores remained significant (p < .01), whereas Daily MIMS did not.

CONCLUSIONS

Our findings suggest that higher PA (both daily accumulated and peak effort) is associated with better cognitive function in the U.S. older adult population.

The Trajectory of Nutritional Status and Physical Activity before and after Transcatheter Aortic Valve Implantation

It is suggested that older patients waiting for an elective surgical procedure have a poor nutritional status and low physical activity level. It is unknown if this hypothesis is true and if these conditions improve after a medical procedure. We aimed to determine the trajectory of both conditions before and after transcatheter aortic valve implantation (TAVI). Included patients (n = 112, age 81 ± 5 years, 58% male) received three home visits (preprocedural, one and six months postprocedural). Nutritional status was determined with the mini nutritional assessment—short form (MNA-SF) and physical activity using an ankle-worn monitor (Stepwatch). The median MNA-SF score was 13 (11−14), and 27% of the patients were at risk of malnutrition before the procedure. Physical activity was 6273 ± 3007 steps/day, and 69% of the patients did not meet the physical activity guidelines (>7100 steps/day). We observed that nutritional status and physical activity did not significantly change after the procedure (β 0.02 [95% CI −0.03, 0.07] points/months on the MNA-SF and β 16 [95% CI −47, 79] steps/month, respectively). To conclude, many preprocedural TAVI patients should improve their nutritional status or activity level. Both conditions do not improve naturally after a cardiac procedure.

Relationships Between Physical Activity Metrics of Intensity and Diabetes

INTRODUCTION

Physical activity (PA) prevents diabetes-associated complications. Little is known about what constitutes effective PA interventions to mitigate diabetes. Identifying PA metrics associated with the efficacy of PA interventions will provide insight into devising strategies to treat diabetes.

PURPOSE

The aim of this study was to analyze the relationships between preclinical and postclinical variables from a 10-week intervention designed to increase PA in adults with diabetes.

METHODS

A secondary analysis was performed to evaluate data using Wilcoxon rank sum test, permutation test and Spearman correlation to analyze hemoglobin A1c (HbA1c), weight, and PA metrics (maximum steps per episode, cadence, daily steps, and 6-minute walk).

RESULTS

Poststudy HbA1c level was associated with maximum steps (r = -0.63, P = .03) and 6-minute walk (r = -0.50, P = .09). Baseline weight was associated with average cadence (r = -0.76, P = .007), and poststudy weight was associated with average cadence (r = -0.60, P = .041) and maximum steps (r = -0.62, P = .03).

CONCLUSIONS

Cadence and maximum steps per episode reflect PA intensity and were associated with HbA1c and weight in adults with diabetes.

Ethnic differences in the relationship between step cadence and physical function in older adults

This study investigated associations between step cadence and physical function in healthy South Asian (SA) and White European (WE) older adults, aged ≥60. Participants completed the 60-s Sit-to-Stand (STS-60) test of physical function. Free-living stepping was measured using the activPAL3™. Seventy-one WEs (age = 72 ± 5, 53% male) and 33 SAs (age = 71 ± 5, 55% male) were included. WEs scored higher than SAs in the STS-60 (23 vs 20 repetitions, p = 0.045). Compared to WEs, SAs had significantly lower total and brisk (≥100 steps/min) steps (total: 8971 vs 7780 steps/day, p = 0.041; brisk: 5515 vs 3723 steps/day, p = 0.001). In WEs, 1000 brisk steps and each decile higher proportion of steps spent brisk stepping were associated with STS-60 (β = 0.72 95% CI 0.05, 1.38 and β = 1.01 95% CI 0.19, 1.82, respectively), with associations persisting across mean peak 1 min (β = 1.42 95% CI 0.12, 2.71), 30 min (β = 1.71 95% CI 0.22, 3.20), and 60 min (β = 2.16 95% CI 0.62, 3.71) stepping periods. Associations were not observed in SAs. Ethnic differences in associations between ambulation and physical function may exist in older adults which warrant further investigationi.

Associations of steps per day and step intensity with the risk of diabetes: the Hispanic Community Health Study / Study of Latinos (HCHS/SOL)

BACKGROUND

Higher levels of moderate-to-vigorous physical activity have been associated with a lower risk of diabetes, but less is known about how daily step counts (steps/day) are associated with diabetes risk. Therefore, we examined the association of steps/day and step intensity with incident diabetes.

METHODS

We included 6634 adults from the population-based prospective cohort Hispanic Community Health Study/Study of Latinos (HCHS/SOL) (2008-2017). Cox proportional hazard models that accounted for complex survey design and sampling weights were used to estimate the association of baseline accelerometer-assessed steps/day and step intensity with 6-year risk of incident diabetes as hazard ratios (HR) and 95% confidence intervals (CI). We further examined whether the percent of intense steps at a given accumulation of steps/day was associated with diabetes risk, and if associations were modified by specific cohort characteristics.

RESULTS

The average age of cohort members was 39 years and 52% were female. Adults had an average of 8164 steps/day and spent 12 min/day in brisk ambulation (> 100 steps/min). Over 6 years of follow-up, there were 1115 cases of diabetes. There was a suggestive lower risk of diabetes with more steps/day- adults had a 2% lower risk per 1000 steps/day (HR = 0.98 (95% CI 0.95, 1.00)). Inverse associations between average steps/day and diabetes incidence were observed across many cohort characteristics, but most importantly among adults at high risk for diabetes - those who were older, or had obesity or prediabetes. Adults who accumulated 17 min/day in brisk ambulation compared to < 2 min/day had a 31% lower risk of diabetes (HR = 0.69 (95% CI 0.53, 0.89)). A greater percent of intense steps for a given accumulation of steps/day was associated with further risk reduction.

CONCLUSION

Adults who accumulate more daily steps may have a lower risk of diabetes. Accumulating more steps/day and greater step intensity appear to be important targets for preventing diabetes.

Associations of steps per day and peak cadence with arterial stiffness in older adults

BACKGROUND

There is evidence showing an inverse association between steps/day and arterial stiffness in adults. However, the relationship of steps/day and peak cadence with arterial stiffness is poorly understood in older adults. This study aimed to investigate the association between steps/day and peak cadence with arterial stiffness in older adults.

METHODS

This cross-sectional study included 222 community-dwelling older adults (66 ± 5 years; 81.5% females; 70.3% with hypertension). Arterial stiffness was measured by aortic pulse wave velocity (aPWV). Steps/day and peak cadence were assessed by accelerometry. The participants were categorized according to the number of steps/day: sedentary <5000; low active 5000-7499; active 7500-9999; highly active 10,000+. Peak cadence was defined as the average of steps/day of the highest 30 min (not necessarily consecutive) for all valid days. Generalized linear models were used for data analyses.

RESULTS

The active (β = -0.34 m/s, 95% CI -0.60, -0.08) and highly active (β = -0.51 m/s, 95% CI -0.83, -0.20) groups had lower aPWV compared to the sedentary group. No significant difference was found between the low active group and the sedentary group (β = -0.21 m/s, 95% CI -0.46, 0.05). Every increment of 1000 steps/day was associated with a decrease of 0.05 m/s in the aPWV (95% CI -0.08, -0.02). Every increment of 10 steps/min in peak 30-min cadence was associated with a decrease of 0.05 m/s in aPWV (95% CI -0.09, -0.01).

CONCLUSIONS

Our findings show that easy-to-use proxies of the volume (steps/day) and intensity (peak cadence) of ambulatory behavior are inversely associated with arterial stiffness in older adults. The inverse association of steps/day and peak cadence with arterial stiffness is dose-response.

Steps per Day and All-Cause Mortality in Middle-aged Adults in the Coronary Artery Risk Development in Young Adults Study

IMPORTANCE

Steps per day is a meaningful metric for physical activity promotion in clinical and population settings. To guide promotion strategies of step goals, it is important to understand the association of steps with clinical end points, including mortality.

OBJECTIVE

To estimate the association of steps per day with premature (age 41-65 years) all-cause mortality among Black and White men and women.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was part of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants were aged 38 to 50 years and wore an accelerometer from 2005 to 2006. Participants were followed for a mean (SD) of 10.8 (0.9) years. Data were analyzed in 2020 and 2021.

EXPOSURE

Daily steps volume, classified as low (<7000 steps/d), moderate (7000-9999 steps/d), and high (≥10 000 steps/d) and stepping intensity, classified as peak 30-minute stepping rate and time spent at 100 steps/min or more.

MAIN OUTCOMES AND MEASURES

All-cause mortality.

RESULTS

A total of 2110 participants from the CARDIA study were included, with a mean (SD) age of 45.2 (3.6) years, 1205 (57.1%) women, 888 (42.1%) Black participants, and a median (interquartile range [IQR]) of 9146 (7307-11 162) steps/d. During 22 845 person years of follow-up, 72 participants (3.4%) died. Using multivariable adjusted Cox proportional hazards models, compared with participants in the low step group, there was significantly lower risk of mortality in the moderate (hazard ratio [HR], 0.28 [95% CI, 0.15-0.54]; risk difference [RD], 53 [95% CI, 27-78] events per 1000 people) and high (HR, 0.45 [95% CI, 0.25-0.81]; RD, 41 [95% CI, 15-68] events per 1000 people) step groups. Compared with the low step group, moderate/high step rate was associated with reduced risk of mortality in Black participants (HR, 0.30 [95% CI, 0.14-0.63]) and in White participants (HR, 0.37 [95% CI, 0.17-0.81]). Similarly, compared with the low step group, moderate/high step rate was associated with reduce risk of mortality in women (HR, 0.28 [95% CI, 0.12-0.63]) and men (HR, 0.42 [95% CI, 0.20-0.88]). There was no significant association between peak 30-minute intensity (lowest vs highest tertile: HR, 0.98 [95% CI, 0.54-1.77]) or time at 100 steps/min or more (lowest vs highest tertile: HR, 1.38 [95% CI, 0.73-2.61]) with risk of mortality.

CONCLUSIONS AND RELEVANCE

This cohort study found that among Black and White men and women in middle adulthood, participants who took approximately 7000 steps/d or more experienced lower mortality rates compared with participants taking fewer than 7000 steps/d. There was no association of step intensity with mortality.

The Bout Cadence Method Improves the Quantification of Stepping Cadence In Free-Living Conditions

BACKGROUND

Existing analytical approaches used to measure free-living stepping cadence (steps per minute; spm) characterize stepping two-ways: 1) 60 s epochs without considering time spent stepping during the epoch (step accumulation; SA), or 2) a bout-based analysis that considers both number of steps and time spent stepping during stepping bouts (total event cadence; TEC). SA and TEC may incorrectly characterize cadence in epochs that do not consist of continuous stepping or if there are marked changes in cadence within a stepping bout, respectively.

RESEARCH QUESTION

How does a bout-based analytical method that examines each stepping bout individually and considers within-bout changes in stepping cadence during epochs ≥120 s (Bout Cadence; BC) compare to SA and TEC?

METHODS

ActivPAL™-derived data from 122 participants were analyzed (790 total days). SA and TEC were calculated according to previous literature. BC calculated cadence bout-by-bout and stride-by-stride for bouts lasting <120 s and ≥120 s, respectively. Time spent stepping between 0-140 spm (divided into 20 spm bins) or >140 spm were determined for each method. Time spent in slow (0-80 spm), medium (80-120 spm) and fast (>120 spm) cadences for each method were compared via Bland-Altman analyses.

RESULTS

Almost half (43 %) of the total number of 60 s epochs included ≥2 stepping bouts, and 37 % of total stepping time was accumulated in continuous stepping bouts ≥120 s. Compared to TEC, BC identified more daily time spent in the 20-40 spm and >120 spm cadence bins, but less time spent in the 60-120 spm range. Both SA (fixed bias: -11.0 ± 12.4 min/day) and TEC (fixed bias: -10.0 ± 13.6 min/day) underestimated faster stepping cadences compared to BC.

SIGNIFICANCE

Existing analytical approaches largely underestimate faster stepping cadences, resulting in inaccurate measurements of vigorous-intensity stepping activity. The BC better characterizes higher intensity stepping activity, which could have important implications for assessing participants' true habitual stepping activity levels.

Impact of sedentarism due to the COVID-19 home confinement on neuromuscular, cardiovascular and metabolic health: Physiological and pathophysiological implications and recommendations for physical and nutritional countermeasures

The COVID-19 pandemic is an unprecedented health crisis as entire populations have been asked to self-isolate and live in home-confinement for several weeks to months, which in itself represents a physiological challenge with significant health risks. This paper describes the impact of sedentarism on the human body at the level of the muscular, cardiovascular, metabolic, endocrine and nervous systems and is based on evidence from several models of inactivity, including bed rest, unilateral limb suspension, and step-reduction. Data form these studies show that muscle wasting occurs rapidly, being detectable within two days of inactivity. This loss of muscle mass is associated with fibre denervation, neuromuscular junction damage and upregulation of protein breakdown, but is mostly explained by the suppression of muscle protein synthesis. Inactivity also affects glucose homeostasis as just few days of step reduction or bed rest, reduce insulin sensitivity, principally in muscle. Additionally, aerobic capacity is impaired at all levels of the O₂ cascade, from the cardiovascular system, including peripheral circulation, to skeletal muscle oxidative function. Positive energy balance during physical inactivity is associated with fat deposition, associated with systemic inflammation and activation of antioxidant defences, exacerbating muscle loss. Importantly, these deleterious effects of inactivity can be diminished by routine exercise practice, but the exercise dose-response relationship is currently unknown. Nevertheless, low to medium-intensity high volume resistive exercise, easily implementable in home-settings, will have positive effects, particularly if combined with a 15-25% reduction in daily energy intake. This combined regimen seems ideal for preserving neuromuscular, metabolic and cardiovascular health.