bioRxiv Science⌕ Search

bioRxiv · 10.1101/325969

Objectively measured physical activity levels and sedentary time in children and adolescents with sickle cell anemia.

Abstract

AbstractThe aim of this study was to identify the levels of physical activity and sedentary behaviour of children and adolescents with sickle cell disease (SCA) compared to healthy individuals. A cross-sectional study with a quantitative approach was performed at a reference center for the treatment of patients with hemoglobinopathies in northeastern Brazil. Patients were recruited between October 2015 and January 2017. Eligible participants answered a Physical Activity Questionnaire for Older Children and Adolescents (PAQ-C) and were instructed to use an ActiGraph wGT3X-BT triaxial accelerometer for seven consecutive days. The analysis of the results was performed using the SPSS software (version 13.0). Differences between means were analysed using the Mann-Whitney U test and the chi-square test was used to evaluate the proportions of occurrence of categorical variables, comparing patient and controls groups. Among the 352 patients in the follow-up, 64 met the inclusion criteria and agreed to participate. Of those, 14 did not use the accelerometer during the 7 consecutive days and were excluded. 50 patients (and their 50 controls) were then evaluated. We observed a statistically significant difference between cases and controls in the variables \"total time of moderate and vigorous physical activity\" (p=0.009 and p=0.0001, respectively) and \"daily mean of moderate and vigorous physical activity\" (p=0.005 and p=0.003). There was also a significant difference among cases and controls in the following variables: \"metabolic equivalent\" (MET), with p=0.04, total of steps (p=0.04) and \"total caloric expenditure\" (p=0.0001), with the worst performances for the group of patients with SCA. Children and adolescents with SCA presented lower levels of physical activity than healthy children and adolescents, both when evaluated by the PAQs or by the accelerometer. The results suggest the need to develop specific programs aimed at promoting physical activity levels and reducing sedentary behaviour among young individuals with SCA.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Melo, H. N., Stoots, S. J.-M., Pool, M. A., Carvalho, V. O., Aragao, M. L. D. C., Gurgel, R. Q., Agyemang, C., Cipolotti, R.. 2018-05-18. Objectively measured physical activity levels and sedentary time in children and adolescents with sickle cell anemia.. https://doi.org/10.1101/325969

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Skeletal muscle aging drives sex- and compartment-specific protein insolubility that is modifiable by proteostasis-directed treatments

Protein aggregation and altered protein solubility indicate proteostatic decline, yet their roles in skeletal muscle aging remain poorly understood. We combined light and electron microscopy, quantitative proteomics, and stable-isotope labeling of skeletal muscle to investigate age-associated changes in protein insolubility, and their responses to exercise and rapamycin. Aged muscle accumulated distinct aggresome and amyloid-positive aggregates despite unchanged bulk insoluble protein content. Instead, aging altered the abundance and soluble-insoluble shifts of lower-abundance proteins across cellular components, particularly mitochondrial, nuclear and extracellular matrix proteins, with greater changes in females. These changes were not broadly explained by intrinsic protein aggregation propensity. Exercise and rapamycin partially reversed age-associated changes in abundance and partitioning without increasing protein synthesis. Together, these findings highlight sex- and cellular component-dependent changes in protein insolubility as important, modifiable aspects of skeletal muscle proteostasis, and indicate that proteostatic maintenance may be a more important target than anabolism for muscle aging.

physiology↗

Trunk muscle activity across various trunk-limb coordination patterns in centipede locomotion

Animals coordinate movements of their limbs and flexible bodies, yet how trunk muscle activity changes across locomotor patterns remains unclear. We simultaneously recorded electromyograms from trunk muscles (deep dorsal oblique muscles) and trunk-limb kinematics in two centipede species exhibiting retrograde and direct locomotor waves during swimming and walking. During swimming, trunk muscle activity followed a similar phase relationship with trunk bending in both species despite opposite wave directions and different involvement of limbs, suggesting common active generation of undulation. During fast walking, trunk muscle activity was strongest around the ipsilateral swing phase in the undulatory retrograde-wave gait of Scolopendra mutilans, but weaker and associated with the ipsilateral stance phase despite the nearly straight trunk in the direct-wave gait of Scolopocryptops rubiginosus. Together, our findings suggest that the same trunk muscles serve two contrasting mechanical roles depending on locomotor mode: either generating trunk undulation or actively straightening the trunk against limb-induced deformation.

physiology↗

Quantifying and Visualizing the Invisible Hazard of Infant Rebreathing

BACKGROUND: Rebreathing of expired gases during prone infant sleeping contributes to hypoxic and hypercapnic exposure, even without airway obstruction. We investigated how anatomical, physiological, and environmental factors influence aerodynamic rebreathing. METHODS: A dynamically scaled in vitro model simulated prone nasal breathing corresponding to infants weighing 2 to 5 kg, with nostril diameters of 3.2 to 6.0 mm and breathing frequencies of 25 to 40 breaths/min. Ambient temperature and sleep-surface characteristics were varied. Rebreathing was quantified using tracer measurements, while flow visualization revealed the underlying aerodynamic mechanisms. RESULTS: Rebreathing exceeded 60% despite unobstructed nasal openings. Increasing ambient temperature from 23 to 30 degrees C increased rebreathing by 68 to 77%, while reducing simulated infant mass from 5 to 2 kg increased rebreathing by 39 to 46%. Fibrous surfaces increased rebreathing, particularly near inclined nasal openings. A novel finding was that increasing nostril diameter from 3.2 to 6.0 mm increased rebreathing by up to 50%. Flow visualization revealed vortical structures that retained expired fluid near the nasal openings, facilitating re-inspiration. CONCLUSIONS: Aerodynamic rebreathing depends strongly on simulated infant characteristics and sleeping environments. These findings are consistent with established safe-sleep recommendations and identify nostril diameter, for the first time, as a potentially important anatomical factor warranting clinical investigation.

physiology↗