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Accelerometry is the gold standard for field-based physical activity assessment in children; however, the plethora of devices, data reduction procedures, and cut-points available limits comparability between studies. This study aimed to compare physical activity variables from the ActiGraph GT3X+ and Actical accelerometers in children under free-living conditions. A cross-sectional study of 379 children aged 9–11 years from Ottawa (Canada) was conducted. Children wore the ActiGraph GT3X+ and Actical accelerometers on the hip simultaneously for 7 consecutive days (24-h protocol). Moderate-to-vigorous (MVPA), vigorous (VPA), moderate (MPA), and light (LPA) physical activity, as well as sedentary time, (SED) were derived using established data reduction protocols. Excellent agreement between devices was observed for MVPA (ICC = 0.73–0.80), with fair to good agreement for MPA, LPA and SED, and poor agreement for VPA. Bland-Altman plots showed excellent agreement for MVPA, LPA, and SED, adequate agreement for MPA, and poor agreement for VPA. MVPA derived from the Actical was 11.7% lower than the ActiGraph GT3X+. The ActiGraph GT3X+ and Actical are comparable for measuring children’s MVPA. However, comparison between devices for VPA, MPA, LPA, and SED are highly dependent on data reduction procedures and cut-points, and should be interpreted with caution. [ABSTRACT FROM PUBLISHER]

Background: Concern over the health effects of BPA, particularly for the developing fetus, has led to an increasing use of bisphenol analogues in industrial and consumer products, which may be as hormonally active as BPA. Biomonitoring data for many bisphenol analogues, especially in pregnant populations, are limited., Methods: We measured concentrations of 14 bisphenol analogues in 1 st trimester urine samples (n = 1851) from the Maternal-Infant Research on Environmental Chemicals (MIREC) Canadian pregnancy cohort (2008-2011). We examined patterns of exposure according to sociodemographic and sampling characteristics as well as occupation and frequency of consumption of canned fish within the previous 3 months., Results: BPA was detected in 89% of participants with a specific gravity standardized geometric mean concentration of 0.990 μg/L. Biphenol 4,4' (BP 4,4'), 4,4'-dihydroxydiphenyl ether (DHDPE), and bisphenol E (BPE) were detected in >97% of participants. Bisphenol F (BPF) and bisphenol S (BPS) were detected in >60% of participants. Specific gravity standardized geometric mean concentrations of these 5 compounds ranged from 0.024 to 0.564 μg/L. Nine bisphenol analogues were detected in <9% of participants. Concentrations of BP 4,4', DHDPE, and BPE were higher in younger women and those with higher pre-pregnancy BMI, lower household income, lower education, and among smokers. We found a similar pattern of differences in BPF for age, education, and smoking status while BPS similarly differed across categories of pre-pregnancy BMI. Participants who were unemployed or working in the service industry had higher molar sum of 7 bisphenol analogues than those working in healthcare, education, or an office setting. Canned fish consumption was not related to bisphenol analogue concentrations., Conclusion: BP 4,4', DHDPE, BPE, BPF, and BPS were highly detected in 1 st trimester urine samples in this large pan-Canadian pregnancy cohort. This suggests widespread exposure to these analogues around 2008-2011 and warrants further investigation into associations with health outcomes., (Copyright © 2023. Published by Elsevier GmbH.)

Objective: In field settings, wrist- and waist-worn accelerometers are typically used to assess sleep characteristics and movement behaviors, respectively. There has been a shift in movement behavior studies to wear accelerometers 24 h/d. Sleep characteristics could be assessed in these studies if sleep algorithms were available for waist-worn accelerometers. The objective of this study was to develop and provide validity data for an algorithm/sleep likelihood score cut-off to estimate sleep efficiency in children using the waist-worn Actical accelerometer., Design: Cross-sectional study., Participants: Fifty healthy children aged 10-13 years., Measurements: Children wore an Actical on their waist and an Actiwatch 2 on their nondominant wrist for 8 nights at home in their normal sleep environment. Participants were randomized into algorithm/sleep likelihood score "development" and "test" groups (n=25 per group). Within the development group, we assessed sleep efficiency with the Actical using the same algorithm that the Actiwatch 2 uses and selected the sleep likelihood score cut-off value that was the most accurate at predicting sleep efficiency at the nightly level compared with the Actiwatch 2. We applied this algorithm and cut-off value to the test group., Results: Mean (SD) sleep efficiency estimates for the test group from the Actical and Actiwatch 2 were 89.0% (3.9%) and 88.7% (3.1%), respectively. Bland-Altman plots and absolute difference scores revealed considerable agreement between devices for both nightly and weekly estimates of sleep efficiency., Conclusion: A waist-worn Actical accelerometer can accurately predict sleep efficiency in field settings among healthy 10- to 13-year-olds., (Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.)