Identifying plasma biomarkers associated with the amount of time an athlete may need before they return to sport (RTS) following a sport-related concussion (SRC) is important because it may help to ...improve the health and safety of athletes.
To examine whether plasma biomarkers can differentiate collegiate athletes who RTS in less than 14 days or 14 days or more following SRC.
This multicenter prospective diagnostic study, conducted by the National Collegiate Athletics Association-Department of Defense Concussion Assessment, Research, and Education Consortium, included 127 male and female athletes who had sustained an SRC while enrolled at 6 Concussion Assessment, Research, and Education Consortium Advanced Research Core sites as well as 2 partial-Advanced Research Core military service academies. Data were collected between February 2015 and May 2018. Athletes with SRC completed clinical testing and blood collection at preseason (baseline), postinjury (0-21 hours), 24 to 48 hours postinjury, time of symptom resolution, and 7 days after unrestricted RTS.
A total of 3 plasma biomarkers (ie, total tau protein, glial fibrillary acidic protein GFAP, and neurofilament light chain protein Nf-L) were measured using an ultrasensitive single molecule array technology and were included in the final analysis. RTS was examined between athletes who took less than 14 days vs those who took 14 days or more to RTS following SRC. Linear mixed models were used to identify significant interactions between period by RTS group. Area under the receiver operating characteristic curve analyses were conducted to examine whether these plasma biomarkers could discriminate between RTS groups.
The 127 participants had a mean (SD) age of 18.9 (1.3) years, and 97 (76.4%) were men; 65 (51.2%) took less than 14 days to RTS, and 62 (48.8%) took 14 days or more to RTS. Linear mixed models identified significant associations for both mean (SE) plasma total tau (24-48 hours postinjury, <14 days RTS vs ≥14 days RTS: -0.65 0.12 pg/mL vs -0.14 0.14 pg/mL; P = .008) and GFAP (postinjury, 14 days RTS vs ≥14 days RTS: 4.72 0.12 pg/mL vs 4.39 0.11 pg/mL; P = .04). Total tau at the time of symptom resolution had acceptable discrimination power (area under the receiver operating characteristic curve, 0.75; 95% CI, 0.63-0.86; P < .001). We also examined a combined plasma biomarker panel that incorporated Nf-L, GFAP, and total tau at each period to discriminate RTS groups. Although the analyses did reach significance at each time period when combined, results indicated that they were poor at distinguishing the groups (area under the receiver operating characteristic curve, <0.7).
The findings of this study suggest that measures of total tau and GFAP may identify athletes who will require more time to RTS. However, further research is needed to improve our ability to determine recovery following an SRC.
Major changes in the timing, duration, and function of sleep occur during childhood. These changes include the transition from habitual napping to infrequent napping. This transition is likely to ...reflect, at least in part, neurocognitive development. This study sought to identify factors that discriminate between four groups of children with different teacher-reported responses to naptime in childcare: those who nap (nappers), sometimes nap (transitioners), do not nap (resters), and neither nap, nor lie still (problem nappers).
Standardized observations of sleep and sleep behaviors, daytime behaviors across a number of domains, and direct neurocognitive assessment of 158 preschool aged children (aged 49-72 months; 54% male) attending childcare centers in Queensland (QLD), Australia, were adopted as part of a large longitudinal study of early childhood, the Effective Early Education Experiences (E4Kids) study. Discriminant function analysis was used to examine how age, parent education, nighttime sleep duration, cognitive functioning, behavior problems, and temperament differentiated the four groups.
Three discriminant functions were identified and defined as maturation (strong loadings of nighttime sleep duration, cognitive function, and age), socioeconomic status (parental education), and behavioral problems (externalizing behavior, temperament, and internalizing behavior). These functions accounted for 62.9%, 32.6%, and 4.5% of the between-groups variance, respectively. Children defined as nappers (n=44) had significantly shorter duration of nighttime sleep, were younger, and had lower cognitive functioning scores than did other groups. Problem nappers, (n
25) were more likely to have parents with lower levels of education than did transitioners (n=41). Standard behavior and temperament measures did not significantly differentiate the groups.
The findings support an interaction between cognitive development, sleep behaviors, and the individual needs and circumstances of children. Further research in this area could make a strong contribution to theory and practice in early childhood education, and a strong contribution to understanding of children's development.
•We assessed the emotional and behavioral climate of sleep-time in 113 ECEC rooms.•This is the first use of a subset of the CLASS Pre-K in the context of sleep-time.•71% of children did not sleep, ...during the designated sleep period.•Emotional climate and behavioral management ratings declined between sessions.•Classrooms with longer mandated sleep times had lower ratings of emotional climate.
The majority of children cease napping between 3 and 5 years of age yet, internationally, the allocation of a sleep time during the day for children of this age remains a practice in many early childhood education (ECE) settings. These dual circumstances present a disjuncture between children's sleep needs and center practices, that may cause conflict for staff, increase stress for children and escalate negative emotional climate in the room. Testing this hypothesis requires observation of both the emotional climate and behavioral management used in ECE rooms that extends into the sleep time. This study was the first to apply the Classroom Assessment and Scoring System (CLASS) Pre-K (Pianta, La Paro, & Hamre, 2008) to observe the emotional climate and behavioral management during sleep time. Pilot results indicated that the CLASS Pre-K functioned reliably to measure emotional climate and behavioral management in sleep time. However, new sleep-specific examples of the dimensions used were developed, to help orient fieldworkers to the CLASS Pre-K rating system in the sleep time context. The CLASS was then used to assess emotional climate and behavior management between the non-sleep and sleep time sessions, in 113 ECE rooms in Queensland, Australia. In these rooms 2.114 children were observed. Of these children, 71% did not sleep at any point during the allotted sleep times. There was a significant drop in emotional climate and behavioral management between the non-sleep and sleep-time sessions. Furthermore, the duration of mandated sleep time (a period of time where no activities are provided to non-sleeping children) accounted for significant independent variance in the observed emotional climate during sleep-time. The CLASS Pre-K presents a valuable tool to assess the emotional climate and behavior management during sleep-time and draws attention to the need for further studies of sleep time in ECE settings.
To examine the associations between sleep parameters and weight status in a large sample of preschool children.
Cross-sectional survey data from the Effective Early Educational Experiences for ...children (E4Kids) study were analyzed.
1111 children aged 3 to 6 years from Queensland and Victoria, Australia.
General linear modeling, with adjustment for significant control variables, assessed the impact of night sleep duration, total sleep duration, napping frequency, sleep timing (onset, offset and midpoint), and severity of sleep problems on standardized body mass index (BMI z score). General linear modeling was conducted for the total sample and then separately by sex.
For the total sample, there was a significant association between short sleep duration (≤10 hours) and increased BMI z score. No other sleep parameters were associated with BMI z score in this sample. Analyses by sex revealed that, among girls, there were no associations between any sleep parameter and BMI z score. However, among boys, short night sleep duration and napping frequency were both significantly associated with weight status even after adjustment for controls.
Night sleep duration is a consistent independent predictor of body mass in young children. These results identify a complex relationship between sleep and body mass that implicates sex. Potential mechanisms that might explain sex differences warrant further investigation.
Abstract Background While most children cease napping between the ages of 2 and 5 years, across a range of international settings the allocation of a mandatory naptime is a common feature of the ...daily routine in Early Care and Education (ECE) programs for children of this age. Evidence regarding the developmental effects of napping is limited but, beyond age 2, is consistently associated with delayed night sleep onset and increased number of awakenings. Objectives The present study examined parent preferences towards napping in ECE. Methods Participants were 750 parents of preschool-aged children attending a representative sample of Australian ECE programs across metropolitan, regional and rural sites in 2011. We analysed quantitative and open-ended questionnaire data from a large, longitudinal study of the effectiveness of Australian early education programs (E4Kids). Statistical analyses examined prevalence of parent preference for sleep and demographic correlates. Thematic analyses were employed to identify parents' rationale for this preference. Results The majority of parents (78.7%) preferred that their children did not regularly sleep while attending ECE. The dominant explanation provided by parents was that regular naps were no longer appropriate and adversely impacted their children's health and development. Parents of younger children were more likely to support regular naps. Conclusions The results highlight a disjuncture between parent preferences and current sleep policy and practices in ECE. Further research is needed to establish evidence-based guidelines to support healthy sleep-rest practices in ECE. Such evidence will guide appropriate practice and support parent-educator communication regarding sleep and rest.
•HRV indices predict multidimensional driving-related fatigue.•Lower RMSSD associated with greater fatigue in young drivers.•Higher LF/HF ratio linked to higher fatigue levels.•Findings support HRV ...metrics as fatigue biomarkers.•Applied research needed to validate real-world use.
Driver fatigue significantly impairs performance and is a major risk factor for road crashes. However, fatigue is difficult to objectively measure and quantify. This study aimed to elucidate associations between heart rate variability (HRV) metrics and multidimensional fatigue construct encompassing objective and subjective measures in young drivers with self-reported short sleep. Eighty-four young adults underwent assessments during simulated driving. HRV indices RMSSD and LF/HF ratio were derived from an electrocardiogram, while relative Theta power, oculography drowsiness, lane position variability, and Karolinska Sleepiness Score measured fatigue. RMSSD negatively correlated with Theta power, and LF/HF ratio positively correlated with position variability. Exploratory factor analysis extracted three factors, with RMSSD and LF/HF loading onto one. Structural equation modelling tested the prediction of a latent fatigue construct from HRV. Two models demonstrated an acceptable fit. RMSSD negatively predicted fatigue, explaining 6.4 % of the variance, while the LF/HF ratio positively predicted fatigue, accounting for 3.7 % of the variance. In summary, HRV, particularly RMSSD, showed significant relationships with multidimensional fatigue. Lower RMSSD and higher LF/HF ratio are associated with greater fatigue levels. This study demonstrates that HRV indices exhibit significant relationships within a multidimensional model of fatigue incorporating objective performance, ocular, and subjective measures. The findings provide initial evidence towards using HRV for monitoring complex manifestations of fatigue, rather than single dimensions. Further applied research should investigate translating these findings to naturalistic settings and validating HRV thresholds predictive of on-road impairment.
Mild traumatic brain injury (TBI) is associated with persistent sleep-wake dysfunction, including insomnia and circadian rhythm disruption, which can exacerbate functional outcomes including mood, ...pain, and quality of life. Present therapies to treat sleep-wake disturbances in those with TBI (e.g., cognitive behavioral therapy for insomnia) are limited by marginal efficacy, poor patient acceptability, and/or high patient/provider burden. Thus, this study aimed to assess the feasibility and preliminary efficacy of morning bright light therapy, to improve sleep in Veterans with TBI (NCT03578003). Thirty-three Veterans with history of TBI were prospectively enrolled in a single-arm, open-label intervention using a lightbox (~10,000 lux at the eye) for 60-minutes every morning for 4-weeks. Pre- and post-intervention outcomes included questionnaires related to sleep, mood, TBI, post-traumatic stress disorder (PTSD), and pain; wrist actigraphy as a proxy for objective sleep; and blood-based biomarkers related to TBI/sleep. The protocol was rated favorably by ~75% of participants, with adherence to the lightbox and actigraphy being ~87% and 97%, respectively. Post-intervention improvements were observed in self-reported symptoms related to insomnia, mood, and pain; actigraphy-derived measures of sleep; and blood-based biomarkers related to peripheral inflammatory balance. The severity of comorbid PTSD was a significant positive predictor of response to treatment. Morning bright light therapy is a feasible and acceptable intervention that shows preliminary efficacy to treat disrupted sleep in Veterans with TBI. A full-scale randomized, placebo-controlled study with longitudinal follow-up is warranted to assess the efficacy of morning bright light therapy to improve sleep, biomarkers, and other TBI related symptoms.
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