Concurrent Agreement Between ActiGraph and activPAL for Measuring Physical Activity in Pregnant Women and Office Workers

Associations of physical activity and sedentary time with aortic stiffness and autonomic function in early pregnancy

Rapid cardiovascular and autonomic adaptations occur during early pregnancy to accommodate augmented cardiac output and placental circulation, with inadequate adaptation associated with hypertensive pregnancy complications. Habitual physical activity (PA) and limiting time in sedentary behavior (SED) may improve pregnancy-related vascular and autonomic function. The objective of this study was to examine the magnitude of the predicted associations between device-measured PA and SED with cardiovascular and autonomic biomarkers including aortic stiffness, blood pressure variability (BPV), and baroreflex sensitivity (BRS) in the first trimester of pregnancy. Pregnant women (N = 92, 21-44 yr of age) free from cardiovascular disease were assessed between 100 and 126 weeks of gestation. Participants wore a thigh-mounted activPAL device for 7 days to assess PA (light intensity and moderate-to-vigorous intensity) and SED. Aortic stiffness was measured by noninvasive applanation tonometry and expressed as carotid-femoral pulse wave velocity (cfPWV). Beat-to-beat blood pressure (BP) and R-R intervals were synchronously recorded for 10 min via finger plethysmography and ECG to derive beat-to-beat BPV and spontaneous cardiovagal BRS (sequence method). In the entire group, neither PA nor SED was related to cfPWV, BPV, or BRS, and this finding was similar in nulliparous and parous pregnant women. In stratified analyses, the association between moderate-to-vigorous-intensity PA and cfPWV differed by gestational age (GA) such that this inverse association was only present in the 12th week of gestation (β = -0.365, P = 0.015). The present study indicates that PA and SED are not associated with aortic stiffness or autonomic function in the first trimester.NEW & NOTEWORTHY Pregnancy is characterized by profound maternal circulatory and autonomic adaptations, but the impact of modifiable factors, such as physical activity and sedentary behavior on vascular and autonomic function during pregnancy, is unclear. We demonstrate that device-measured physical activity and sedentary time are not associated with aortic stiffness, baroreflex sensitivity, and blood pressure variability during the first trimester. The beneficial effect of physical activity on aortic stiffness may become more pronounced with advancing gestational age.

Patterns of physical activity, sedentary behavior, and sleep across pregnancy before and during two COVID pandemic years

BACKGROUND

Physical activity is recommended during pregnancy, and high sedentary behavior and poor sleep may increase the risk of pregnancy complications. Activity patterns and sleep were negatively impacted by the COVID pandemic in many segments of the population, but the impact of the pandemic on pregnant people is understudied. We aimed to compare patterns of physical activity, sedentary time, and sleep during pregnancy between a pre-COVID and a COVID-era cohort.

METHODS

Physical activity, sedentary time, and sleep in each trimester of pregnancy were compared between two parallel prospective observational cohorts using identical collection methods. Pre-COVID participants (n=111) were recruited in 2017-2019 and COVID-era participants (n=117) from 2021-2023. Physical activity and sedentary time were measured using the activPAL3 micro accelerometer, and sleep duration was self-reported. Between-cohort comparisons were conducted using linear regression for each behavior in each trimester. Within-COVID-era cohort linear regression analyses assessed whether activity patterns differed as pandemic-era restrictions were eased.

RESULTS

Participant demographics were similar between cohorts except for self-reported income. Adjusted mean moderate-to-vigorous physical activity was 57-77 min/week higher in each trimester in pre-COVID compared to COVID-era participants (p<0.001); adjusted mean sedentary time was 0.77-1.13 hours/day lower in each trimester (p<0.01) and sleep duration was 0.8 hours/day lower in the third trimester in the pre-COVID compared to COVID-era cohort (p<0.05). Within the COVID-era cohort, no significant within-trimester differences were detected across the pandemic years.

CONCLUSIONS

Pregnant participants during the COVID pandemic were less active and more sedentary than their pre-pandemic counterparts, and this trend was still detected years after the pandemic began. A more sedentary lifestyle during pregnancy may have health implications, and prenatal care providers should help pregnant people identify strategies to adopt an active lifestyle in the context of pandemic-era barriers.

The effect of replacing prolonged sitting with intermittent standing during a simulated workday on the subsequent night's sleep

A bout of leisure-time physical activity improves sleep on the subsequent night. However, whether breaking up sedentary time during the workday improves sleep is unknown. The purpose of this study was to examine whether breaking up prolonged sitting by standing during the workday leads to better sleep the following night. 25 inactive adults (16 males, 42.4 ± 11.8 years, body mass index: 31.9 ± 5.0 kg/m2) participated in a randomized crossover trial consisting of two simulated 8-h workdays involving prolonged sitting (SIT) or alternating sitting and standing every 30 min (SIT-STAND). Sleep was assessed on the night following each workday. Participants completed a diary and wore a wrist accelerometer (Actiwatch Spectrum) to assess multiple dimensions of sleep (e.g., timing, duration, wakefulness, quality). Paired t-tests and Hedges' g effect sizes evaluated differences in sleep across conditions. Self-reported wakefulness after sleep onset (WASO) was significantly lower following SIT-STAND compared to SIT (13.9 ± 30.1 min vs. 23.2 ± 38.6 min; p = 0.03, g = - 0.51), mirrored by a small-sized nonsignificant reduction in accelerometer-assessed WASO following SIT-STAND compared to SIT (32.7 ± 13.6 min vs. 40.8 ± 25.8 min; p = 0.06, g = - 0.38). Mean accelerometer-based activity levels during sleep were also lower following SIT-STAND compared to SIT (10.8 ± 14.5 vs. 14.7 ± 10.4 counts/min; p = 0.03, g = - 0.47). Other sleep outcomes (e.g., bed- and wake-time, total sleep time, sleep onset latency) were not different between conditions. Alternating sitting and standing rather than prolonged sitting during a simulated workday modestly reduces night-time wakefulness. Whether similar benefits occur with long-term reduction in workplace sedentary behavior deserves further exploration.

The sedentary behavior reduction in pregnancy intervention (SPRING) pilot and feasibility randomized trial

Pregnant individuals rarely achieve moderate-to-vigorous intensity physical activity recommendations.Purpose The sedentary behavior reduction in pregnancy intervention (SPRING) pilot and feasibility randomized trial aimed to demonstrate feasibility, acceptability, and initial efficacy of a lower intensity intervention targeting reduced sedentary behavior and increased standing and steps.Methods First trimester pregnant individuals at risk for high sedentary behavior and adverse pregnancy outcomes (APO) were randomized 2:1 to a multi-component sedentary behavior reduction intervention or no-contact control. Intervention components included biweekly remote health coaching, wearable activity monitor, height-adjustable workstation, and a private Facebook group. Evidence-based behavioral targets included sedentary time < 9 h/day, increasing standing by 2-3 h/day, and ≥ 7500 steps/day. Participants completed all-remote assessments (baseline, second trimester, third trimester) of sedentary behavior and activity (thigh-worn activPAL) along with exploratory pregnancy health outcomes abstracted from medical records. Intervention effects vs. control were evaluated using generalized mixed models and an intention-to-treat approach. Intervention participants also provided feedback on perceived benefits and acceptability.Results Participants (34 intervention; 17 control) had mean age 32 years, were 83% White, with mean pre-pregnancy BMI 28 kg/m2. Retention was high (90% and 83% at second and third trimester follow-up visits). Intervention participants decreased sedentary time (-0.84 h/day, p = 0.019) and increased standing (+0.77 h/day, p = 0.003), but did not increase steps/day (+710, p = 0.257) compared to controls. Intervention participants reported many perceived benefits and identified the wearable, height-adjustable workstation, and behavioral lessons as most useful.Conclusion For pregnant individuals at risk for high sedentary behavior and APOs, a sedentary behavior reduction intervention is feasible, acceptable, and may offer a viable alternative to more intense physical activity recommendations during pregnancy. Further testing in a fully powered clinical trial is warranted.Trial registration NCT05093842 on clinicaltrials.gov.

Relationship between rest-activity rhythms and cardiorespiratory fitness in middle-aged workers: a cross-sectional study with non-parametric analysis using accelerometers worn on the thigh

BACKGROUND

Rest-activity rhythms are directly related to health risks, but there are limited objective methods to assess them. This study aimed to investigate the relationship between rest-activity rhythms and cardiorespiratory fitness (CRF) in middle-aged workers.

METHODS

Peak oxygen uptake was measured on a treadmill to assess CRF in 254 middle-aged workers who were divided into low, medium, and high-CRF groups based on tertiles. Participants were asked to wear an accelerometer (activPAL) on their thighs for 1 week, and the logarithmically transformed acceleration data were used for the analysis of a 24-hour rest-activity rhythm. Sex, age, body mass index, occupation, smoking status, and alcohol consumption were used as covariates in Model 1, with Model 2 also including walking count on non-workdays. Repeated measures analysis of variance was used to compare time course of rest-activity rhythms changes on workdays between groups, and post-hoc tests were conducted using Bonferroni's correlation.

RESULTS

Higher CRF correlated with increased physical activity. In model 1, higher CRF showed improved interdaily stability, but the significant difference disappeared in model 2 after adjusting for non-workday walking counts. A time-course group comparison showed that the high group had significantly higher activity levels than those of the low group from 6:00 to 8:59 and 17:00 to 17:59 and the medium group from 6:00 to 7:59 and 19:00 to 19:59.

CONCLUSIONS

Workers who have better rest-activity rhythms and engage in higher levels of physical activity on workdays tend to have higher CRF levels. Regular daily routines, influenced by physical activity during holidays, can positively impact cardiopulmonary endurance.

Comparing Multiple Approaches to Estimate Physical Activity, Sedentary Behavior, and Sleep in Pregnancy

Introduction

The purpose of this study was to compare estimates of 24-hour activity using the best practice of a thigh accelerometer (activPAL), wrist actigraphy (Actiwatch), and a sleep diary (PAL + watch + diary) to estimates from simpler procedures, such as the thigh accelerometer and diary (PAL + diary) or thigh monitor alone (PAL only) during pregnancy.

Methods

Data collected during the 2nd trimester from 40 randomly selected participants in the Pregnancy 24/7 cohort study were included. activPAL data were integrated with sleep time determined by wrist actigraphy (PAL + watch + diary) or diary-determined sleep (PAL + diary). In the PAL only analysis, average estimates were exported directly from the PAL software. Repeated measures ANOVA and intraclass correlations coefficients compared moderate-vigorous physical activity (MVPA), light physical activity (LPA), sedentary time, sleep, and wear time across measurement approaches. Pairwise comparisons using a Bonferroni correction explored significant differences identified from the omnibus ANOVA.

Results

The three approaches arrived at consistent durations of physical activity (intraclass correlations coefficients > .95) but not for estimating sedentary behavior and sleep durations (intraclass correlations coefficients: .73-.82). PAL + diary overestimated MVPA by 2.3 min/day (p < .01) compared with PAL + diary + watch. PAL only overestimated sleep (25.3-29.0 min/day, p < .01) while underestimating MVPA (11.7-14.0 min/day, p < .01) compared with the other approaches.

Conclusions

Since the inclusion of the wrist actigraphy provided only slight differences in MVPA estimates, PAL + diary may provide acceptable estimates of 24-hour activity during pregnancy in future research. PAL only may be acceptable when exclusively interested in physical activity.

Influence of Recent Standing, Moving, or Sitting on Daytime Ambulatory Blood Pressure

Background There are no recommendations for being seated versus nonseated during ambulatory blood pressure (BP) monitoring (ABPM). The authors examined how recent standing or moving versus sitting affect average daytime BP on ABPM. Methods and Results This analysis used baseline assessments from a clinical trial in desk workers with office systolic BP (SBP) 120 to 159 mm Hg or diastolic BP (DBP) 80 to 99 mm Hg. ABPM was measured every 30 minutes with a SunTech Medical Oscar 2 monitor. Concurrent posture (standing or seated) and moving (steps) were measured via a thigh-worn accelerometer. Linear regression determined within-person BP variability explained (R2) by standing and steps before ABPM readings. Mean daytime BP and the prevalence of mean daytime BP >135/85 mm Hg from readings after sitting (seated) or after recent standing or moving (nonseated) were compared with all readings. Participants (n=266, 59% women; age, 45.2±11.6 years) provided 32.5±3.9 daytime BP readings. Time standing and steps before readings explained variability up to 17% for daytime SBP and 14% for daytime DBP. Using the 5-minute prior interval, seated SBP/DBP was lower (130.8/79.7 mm Hg, P<0.001) and nonseated SBP/DBP was higher (137.8/84.3 mm Hg, P<0.001) than mean daytime SBP/DBP from all readings (133.9/81.6 mm Hg). The prevalence of mean daytime SBP/DBP ≥135/85 mm Hg also differed: 38.7% from seated readings, 70.3% from nonseated readings, and 52.6% from all readings (P<0.05). Conclusions Daytime BP was systematically higher after standing and moving compared with being seated. Individual variation in activity patterns could influence the diagnosis of high BP using daytime BP readings on ABPM.

Rationale, Design, and Methods for the Sedentary Behavior Reduction in Pregnancy Intervention (SPRING): Protocol for a Pilot and Feasibility Randomized Controlled Trial

BACKGROUND

Adverse pregnancy outcomes (APOs) identify cardiovascular disease risk, but few effective interventions are available. High sedentary behavior (SED) has recently been associated with APOs, but very few randomized controlled trials (RCTs) have tested SED reduction in pregnancy.

OBJECTIVE

The Sedentary Behavior Reduction in Pregnancy Intervention (SPRING) pilot and feasibility RCT addresses this gap by testing the feasibility, acceptability, and preliminary pregnancy health effects of an intervention to reduce SED in pregnant women. The objective of this manuscript is to describe the rationale and design of SPRING.

METHODS

Pregnant participants (n=53) in their first trimester, who are at risk for high SED and APO and without contraindications, are randomized in a 2:1 ratio to an intervention or control group. SED (primary outcome) and standing durations, and steps per day, are measured objectively in each trimester for 1 week with a thigh-mounted activPAL3 accelerometer. SPRING also seeks to demonstrate feasibility and acceptability while estimating preliminary effects on maternal-fetal health outcomes assessed during study visits and abstracted from medical records. The pregnancy-customized intervention promotes daily behavioral targets of less than 9 hours of SED and at least 7500 steps, achieved via increased standing and incorporating light-intensity movement breaks each hour. The multicomponent intervention provides a height-adjustable workstation, a wearable activity monitor, behavioral counseling every 2 weeks (through videoconference), and membership in a private social media group. Herein, we review the rationale, describe recruitment and screening processes, and detail the intervention, assessment protocols, and planned statistical analyses.

RESULTS

This study was funded by the American Heart Association (20TPA3549099), with a funding period of January 1, 2021, and until December 31, 2023. Institutional review board approval was obtained on February 24, 2021. Participants were randomized between October 2021 and September 2022, with final data collection planned for May 2023. Analyses and submission of results are expected for winter of 2023.

CONCLUSIONS

The SPRING RCT will provide initial evidence on the feasibility and acceptability of an SED-reduction intervention to decrease SED in pregnant women. These data will inform the design of a large clinical trial testing SED reduction as a strategy to reduce APO risk.

TRIAL REGISTRATION

ClincialTrials.gov NCT05093842; https://clinicaltrials.gov/ct2/show/NCT05093842.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/48228.