A closer look at the relationship among accelerometer-based physical activity metrics: ICAD pooled data

Quantifying the time-varying association between objectively measured physical activity and mortality in US older adults over a 12-year follow-up period: the NHANES 2003-2006 study

Objectively measuring physical activity (PA) has consistently shown an association with reduced all-cause mortality risk in cross-sectional studies. However, the strength of this association may change over time. We quantify the time-varying, covariate-adjusted association between the total volume of PA and all-cause mortality over a 12-year follow-up period using Cox regression with a time varying effect of population-referenced quantile total activity count adjusted for traditional risk factors. Analyses focus on participants 50-84 years old with adequate accelerometer wear time and without missing covariates. The findings suggest that (1) the use of baseline PA in Cox models with long follow-up periods may be inappropriate without time-varying effects and (2) the use of accelerometry derived volume of PA in risk score calculations may be most appropriate for short-term to medium-term risk scores.

Accelerometry measures of physical activity and sedentary behavior: Associations with cognitive functioning in MS

BACKGROUND

Cognitive dysfunction is a pervasive symptom of multiple sclerosis (MS). Correlational evidence on the relationships between physical activity, sedentary behavior, and cognition has been mixed and limited to a few activity measures. The collinearity of accelerometry-based metrics has precluded an assessment of the full activity spectrum. Here, we aimed to examine the rich set of activity measures using analytic approaches suitable for collinear metrics. We investigated the combination of physical activity, sedentary, and clinicodemographic measures that explain the most variance in composite scores of working memory/processing speed, visual memory, and verbal memory.

METHODS

We analyzed baseline accelerometry and neuropsychological data (n = 80) from a randomized controlled trial of pedometer tracking. Using partial least squares regression (PLSR), we built three models to predict latent scores on the three domains of cognition using 12 activity metrics, sex, education, and Expanded Disability Status Scale (EDSS) scores. Significance was assessed using linear regression models with model component scores as predictors and cognitive composites as outcomes.

RESULTS

The latent component was significant for working memory/processing speed but was not significant for visual memory and verbal memory after Bonferroni correction. Working memory/processing speed was positively associated with average kilocalories, moderate-to-vigorous physical activity (MVPA), steps, and sex (i.e., higher scores in males) and negatively related to duration of long sedentary bouts and EDSS.

CONCLUSIONS

These findings suggest that increasing overall energy expenditure through walking and MVPA, while decreasing prolonged sedentary time may positively benefit working memory/processing speed in people with MS.

TRIAL REGISTRATION

This RCT #NCT03244696 was registered on Clinicaltrials.gov (https://www.

CLINICALTRIALS

gov/ct2/show/NCT03244696).

Testing the Effect of a Smartphone App on Hospital Admissions and Sedentary Behavior in Cardiac Rehabilitation Participants: ToDo-CR Randomized Controlled Trial

BACKGROUND

People with coronary heart disease are at an increased risk of morbidity and mortality even if they attend cardiac rehabilitation. High sedentary behavior levels potentially contribute to this morbidity. Smartphone apps may be feasible to facilitate sedentary behavior reductions and lead to reduced health care use.

OBJECTIVE

We aimed to test the effect of a sedentary behavior change smartphone app (Vire app and ToDo-CR program) as an adjunct to cardiac rehabilitation on hospital admissions and emergency department (ED) presentations over 12 months.

METHODS

A multicenter, randomized controlled trial was conducted with 120 participants recruited from 3 cardiac rehabilitation programs. Participants were randomized 1:1 to cardiac rehabilitation plus the fully automated 6-month Vire app and ToDo-CR program (intervention) or usual care (control). The primary outcome was nonelective hospital admissions and ED presentations over 12 months. Secondary outcomes including accelerometer-measured sedentary behavior, BMI, waist circumference, and quality of life were recorded at baseline and 6 and 12 months. Logistic regression models were used to analyze the primary outcome, and linear mixed-effects models were used to analyze secondary outcomes. Data on intervention and hospital admission costs were collected, and the incremental cost-effectiveness ratios (ICERs) were calculated.

RESULTS

Participants were, on average, aged 62 (SD 10) years, and the majority were male (93/120, 77.5%). The intervention group were more likely to experience all-cause (odds ratio [OR] 1.54, 95% CI 0.58-4.10; P=.39) and cardiac-related (OR 3.26, 95% CI 0.84-12.55; P=.09) hospital admissions and ED presentations (OR 2.07, 95% CI 0.89-4.77; P=.09) than the control group. Despite this, cardiac-related hospital admission costs were lower in the intervention group over 12 months (Aus $252.40 vs Aus $859.38; P=.24; a currency exchange rate of Aus $1=US $0.69 is applicable). There were no significant between-group differences in sedentary behavior minutes per day over 12 months, although the intervention group completed 22 minutes less than the control group (95% CI -22.80 to 66.69; P=.33; Cohen d=0.21). The intervention group had a lower BMI (β=1.62; P=.05), waist circumference (β=5.81; P=.01), waist-to-hip ratio (β=.03, P=.03), and quality of life (β=3.30; P=.05) than the control group. The intervention was more effective but more costly in reducing sedentary behavior (ICER Aus $351.77) and anxiety (ICER Aus $10,987.71) at 12 months. The intervention was also more effective yet costly in increasing quality of life (ICER Aus $93,395.50) at 12 months.

CONCLUSIONS

The Vire app and ToDo-CR program was not an outcome-effective or cost-effective solution to reduce all-cause hospital admissions or ED presentations in cardiac rehabilitation compared with usual care. Smartphone apps that target sedentary behavior alone may not be an effective solution for cardiac rehabilitation participants to reduce hospital admissions and sedentary behavior.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12619001223123; https://australianclinicaltrials.gov.au/anzctr/trial/ACTRN12619001223123.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1136/bmjopen-2020-040479.

The Influence of Accelerometer Epoch Length on Associations of Physical Activity Intensity and Volume with Bone Outcomes

Two accelerometer metrics (intensity-gradient and average-acceleration) can be used to determine the relative contributions of physical activity (PA) volume and intensity for health, but it is unknown whether epoch length influences the associations detected. This is important when considering bone health, as bone is particularly responsive to high intensity PA, which may be underestimated by longer epochs. This study aimed to assess the associations between average-acceleration, a proxy measure of PA volume, and intensity-gradient, reflective of PA intensity distribution, from PA data from 1-s to 60-s epochs at age 17 to 23 years with bone outcomes at age 23 years. This is a secondary analysis of 220 participants (124 females) from the Iowa Bone Development Study, a longitudinal study of bone health from childhood to early adulthood. Accelerometer-assessed PA data, captured at age 17 to 23 years, were summarised over 1-s, 5-s, 15-s, 30-s, and 60-s epochs, to generate average-acceleration and intensity-gradient from each epoch length, averaged across ages. Regression analysed associations between mutually adjusted average-acceleration and intensity-gradient with dual-energy X-ray absorptiometry assessed total-body-less-head (TBLH) bone mineral content (BMC), spine areal bone mineral density (aBMD), hip aBMD, and femoral neck cross-sectional area and section modulus at age 23 years. Intensity-gradient was positively associated with TBLH BMC in females, with spine aBMD in males, and with hip aBMD and geometry in both sexes, when a 1 to 5-s epoch was used. Average-acceleration was positively associated with TBLH BMC, spine aBMD and hip aBMD in males, generally when the adjustment for intensity-gradient was from > 1-s epochs. Intensity and volume were important for bone outcomes in both sexes and males, respectively. A 1 to 5-s epoch length was most appropriate to assess the mutually adjusted associations of intensity-gradient and average-acceleration with bone outcomes in young adults.

Association of device-measured physical activity and sedentary behaviour with cardiovascular risk factors, health-related quality-of-life and exercise capacity over 12-months in cardiac rehabilitation attendees with coronary heart disease

Background

Few studies have considered the relationship between risk factors, physical activity and sedentary behaviour in people with heart disease. Here we examine the independent relationship of device-measured physical activity and sedentary behaviour on risk factors, quality-of-life and exercise capacity over 12-months in cardiac rehabilitation attendees.

Methods

Hospital-based phase II cardiac rehabilitation participants with coronary heart disease were assessed at the start and end of cardiac rehabilitation (6-weeks), 6 and 12-months. Physical activity (moderate-to-vigorous (MVPA), light-intensity (LIPA); min/day) and sedentary behaviour (min/day, bouts, breaks) were measured using an ActiGraph accelerometer. Risk factors included waist circumference, body mass index, systolic blood pressure (SBP), fasting blood lipid and glucose levels, anxiety and depression. Quality-of-life and exercise capacity were also collected. Associations were assessed with Generalized Estimating Equation modeling.

Results

Sixty-seven participants were included (mean age = 64 (SD 9) years; 81% male). An association was found between higher MVPA and lower high density lipoprotein (p ≤ 0.001). No significant (p ≤ 0.001) associations were found between sedentary behaviour variables and other outcomes. At p < 0.05 several associations were significant. Increased MVPA and LIPA were associated with decreased total cholesterol. Higher MVPA was associated with decreased SBP, whereas higher LIPA was associated with decreased waist circumference and body mass index. Higher sedentary behaviour bouts and breaks were associated with increased total cholesterol, anxiety and depression, and decreased SBP over time.

Conclusions

Any intensity of physical activity was associated with decreased total cholesterol. Increased LIPA was associated with improved measures of adiposity, while breaking up sedentary behaviour and increasing MVPA may decrease SBP over time. Further investigation of MVPA, LIPA and the distribution of sedentary behaviour is indicated in cardiac rehabilitation attendees to explore their relationship with risk factors.

Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12615000995572, http://www.ANZCTR.org.au/ACTRN12615000995572.aspx. Registered 22 September 2015.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-022-00562-7.

Seasonal variations in physical activity among Norwegian elementary school children in Arctic regions

The aim of this study was to measure seasonal variations in physical activity (PA) during Polar Nights (PN) and Polar Days (PD) among elementary school children in the Arctic regions of Norway. One hundred and seventy-eight schoolchildren from 1st, 3rd, 5thand 7th grade participated in the study. Physical activity was measured for seven consecutive days with an ActiGraph GT3X-BT accelerometer and is expressed as total PA incounts per minute (cpm) and moderate-to-vigorous activity (MVPA) (min∙day-1). During PN, 51% of boys and 33% of girls met the PA recommendations, whereas 36% of boys and 34% of girls met the recommendations during PD. Time spent doing MVPA did not differ between the two seasons (all p ≥ 0.073). Overall, the children accumulated 613 ±154 cpm during PN, which was lower than during PD 704 ± 269 cpm, p < 0.001). A larger proportion of boys than girls met the PA recommendations during PN compared with PD. Our findings did not show any clear seasonal variation for MVPA or total PA among children,except for some differences within sexes in different grades. This study indicates that interventions aimed at increasing PA should be implemented throughout the year in the Arctic regions. .

Associations of fitness, motor competence, and adiposity with the indicators of physical activity intensity during different physical activities in children

We investigated the associations of peak oxygen uptake (V̇O2peak), ventilatory threshold (VT), muscle strength, motor competence (MC), and adiposity with the indicators of PA intensity during different physical activities used to create absolute PA intensity cut-offs among 35 children 7-11-years-of-age. V̇O2peak was defined as the highest V̇O2 achieved in the maximal cardiopulmonary exercise test (CPET) on a cycle ergometer, self-paced running, or running on a treadmill at 8 km/h. VT was defined from the CPET data. Peak isometric knee extensor and flexor strength was assessed by a dynamometer, MC by the Körperkoordination test für Kinder tests, and body composition by the bioelectrical impedance analysis. PA intensity was assessed using V̇O2 as a % of V̇O2reserve or V̇O2 at VT, mean amplitude deviation (MAD) measured by accelerometry, metabolic equivalent of task (MET), and muscle activity measured by textile electromyography during walking or running on a treadmill at 4, 6, and 8 km/h, playing hopscotch, walking up and down the stairs, self-paced walking, and self-paced running. Children with lower V̇O2peak, V̇O2 at VT, and MC operated at higher intensity level during given physical task than their peers with higher fitness and MC when PA intensity was expressed using relative PA intensity using V̇O2 as a % of V̇O2reserve or V̇O2 at VT (p < 0.05). MAD and METs during different tasks were not able to discriminate PA intensity between children with varying levels of physical fitness or MC. Traditionally used absolute measures of PA intensity based on accelerometry or MET underestimated PA intensity in children with lower V̇O2peak, V̇O2 at VT, and MC.

Physical Activity across Retirement Transition by Occupation and Mode of Commute

Supplemental digital content is available in the text.

Purpose

Retirement induces changes in the composition of daily physical activity. Our aim was to examine changes in accelerometer-measured physical activity around transition to statutory retirement among men and women by occupational category and by preretirement modes of commuting.

Methods

We included 562 workers (mean [SD] age, 63.3 [1.1] yr; 85% women) from the Finnish Retirement and Aging study. The participants wore an accelerometer on their nondominant wrist for 1 wk before and 1 wk after retirement, with 1 yr between the measurements. We compared mean daily activity counts before and after retirement between manual and nonmanual occupations by gender and by preretirement commuting mode using linear models with generalized estimating equations.

Results

Before retirement, women were more active than men (2550 (95% confidence interval, 2500–2590) vs 2060 (1970–2140) mean daily activity counts), with the most active group being women in manual occupations. After retirement, physical activity decreased by 3.9% among women and increased, albeit nonsignificantly, by 3.1% in men. The decrease was most pronounced among women in manual and increase among men in nonmanual occupations. After retirement, women remained more active than men (2450 (95% confidence interval 2390–2500) vs 2120 (2010–2230) counts). Active commuting, especially cycling, before retirement was associated with higher physical activity both before and after retirement, and these people also maintained their total activity lever better than did those who commuted by public transportation.

Conclusions

Although women in manual occupations decreased and men in nonmanual occupations increased their activity after retirement, women were more active than men both before and after retirement. Those who engaged in active commuting before retirement maintained their activity level also after retirement.

Cross-sectional and prospective associations between aerobic fitness and lipoprotein particle profile in a cohort of Norwegian schoolchildren

BACKGROUND AND AIMS

The associations between aerobic fitness and traditional measures of lipid metabolism in children are uncertain. We investigated whether higher levels of aerobic fitness benefit lipoprotein metabolism by exploring associations with a comprehensive lipoprotein particle profile.

METHODS

In our prospective cohort study, we used targeted proton nuclear magnetic resonance (¹H NMR) spectroscopy to profile 57 measures of lipoprotein metabolism from fasting serum samples of 858 fifth-grade Norwegian schoolchildren (49.0% girls; mean age 10.0 years). Aerobic fitness was measured using an intermittent shuttle run aerobic fitness test. We used multiple linear regression adjusted for potential confounders to examine cross-sectional and prospective associations between aerobic fitness and lipoprotein particle profile.

RESULTS

Higher levels of aerobic fitness were associated with a favourable lipoprotein particle profile in the cross-sectional analysis, which included inverse associations with all measures of very low-density lipoprotein (VLDL) particles (e.g., -0.06 mmol·L^-1 or -0.23 SD units; 95% CI = -0.31, -0.16 for VLDL cholesterol concentration). In the prospective analysis, the favourable pattern of associations persisted, though the individual associations tended to be more consistent with those of the cross-sectional analysis for the VLDL subclass measures compared to the low-density lipoproteins and high-density lipoproteins. Adjustment for adiposity attenuated the associations in both cross-sectional and prospective models. Nevertheless, an independent effect of aerobic fitness remained for some measures.

CONCLUSIONS

Improving children's aerobic fitness levels should benefit lipoprotein metabolism, though a concomitant reduction in adiposity would likely potentiate this effect.

Associations of age, body size, and maturation with physical activity intensity in different laboratory tasks in children

We investigated the associations of age, sex, body size, body composition, and maturity with measures of physical activity (PA) intensity in children. PA intensity was assessed using VO₂ as % of VO_2reserve or VO₂ at ventilatory threshold (VT), muscle activity measured by textile electromyography, mean amplitude deviation (MAD) measured by accelerometry, and metabolic equivalent of task (MET) during laboratory activities.Age, stature, and muscle mass were inversely associated with VO2 as % of VO_2reserve and % of VT, during walking or running on a treadmill for 4, 6, and 8 km/h (Spearman r = -0.645 to -0.358). Age was inversely associated with MAD during walking on treadmill for 4 km/h (r = -0.541) and positively associated with MAD during running on a treadmill for 8 km/h, playing hopscotch, and during self-paced running (r = 0.368 to 0.478). Fat mass was positively associated with VO2 as % of VO_2reserve and VO2 as % of VO2 at VT and waist circumference was positively associated with VO2 as a % of VO_2reserve and muscle activity during stair climbing (r = 0.416 to 0.519).Fixed accelerometry cut-offs used to define PA intensities should be adjusted for age, sex, body size, and body composition.

Association between Physical Activity and Mood States of Children and Adolescents in Social Isolation during the COVID-19 Epidemic

The COVID-19 epidemic adversely affects the lifestyle of people. This study aimed to examine the impacts of social isolation on physical activity (PA) levels and mood states of children and adolescents and to explore the correlation between them during the COVID-19 epidemic. A total of 9979 children and adolescents (11.63 ± 1.23 years old) from Yan’an, China volunteered to participate in this study and completed online questionnaires. PA and mood states were measured by International Physical Activity Questionnaire Short Form (IPAQ-SF) and Profile of Mood States (POMS), respectively. The results showed that the mean of students’ moderate-to-vigorous PA (MVPA) was 23.19 min per day. The total mood disturbance in the moderate and high-level PA groups were significantly lower than those in the low-level PA group (p < 0.05). Additionally, boys and girls had significant differences in PA levels (p < 0.01), and the PA levels of students in different grades were also significantly different (p < 0.01). Meanwhile, boys’ mood states were worse than girls’. The Grade 4 in primary schools had the worst mood states while Grade 5 had the best mood states. The results suggested that the MVPA of students has dropped badly, compared with the results of previous studies investigated in normal times. In addition, the PA level had a significantly positive impact on the mood states of children and adolescents during the COVID-19 epidemic. Sex and grades were factors which affected the PA levels and mood states. This study can help policymakers and healthcare professionals understand PA and mood states of Chinese children and adolescents during the epidemic. We should pay attention to the changes in PA levels and mood states of children and adolescents.

Accelerometer-measured physical activity and sedentary behavior in Chinese children and adolescents: a systematic review and meta-analysis

OBJECTIVE

To synthesize evidence on accelerometer-measured moderate-to-vigorous physical activity (MVPA) and sedentary behavior (SB) levels of Chinese children and adolescents.

STUDY DESIGN

This is both a systematic review and meta-analysis study.

METHODS

Online databases were searched for studies published from January 2009 up to February 2019. These studies reported accelerometer-measured daily minutes of MVPA and/or SB among Chinese children and adolescents. Random-effects meta-analysis was used to separately pool the time spent in MVPA and SB.

RESULTS

Of 4754 records, 20 studies were included in the meta-analysis. Sample sizes ranged from 96 to 2163. The meta-analysis showed that Chinese children and adolescents spent 41.11 min/day in MVPA and 529.83 min/day in SB averagely. Boys spent more time in MVPA compared with girls (P = 0.01). Children accumulated more MVPA time than adolescents (P = 0.05), and children spent less time in SB than adolescents (P = 0.05). Unlike weekdays, SB was lower on weekends (P = 0.02). There were significant differences in children and adolescents' MVPA time in regions (P < 0.001).

CONCLUSIONS

MVPA level in Chinese children and adolescents is well below international recommendations, and their SB level is very high.

Correction to: A closer look at the relationship among accelerometer-based physical activity metrics: ICAD pooled data

Following publication of the original article [1], the author reported that the name of the collaborator group was missing from the author group.