The relationship between sleep duration and obesity in adolescents is inconclusive. This may stem from a more complex relationship between sleep and obesity than previously considered. Shifts towards evening preferences, later sleep-wake times, and irregular sleep-wake patterns are typical during adolescence but their relationship to body mass index has been relatively unexplored. This cross sectional study examined associations between sleep duration, midpoint of sleep, and social jetlag (estimated from seven days of continuous actigraphy monitoring) and morningness/eveningness with body mass indexes (BMI z scores) and waist to height ratios in 14 to 17 year old adolescents. Seventy participants were recruited from 9th and 10th grades at a public high school. Participant characteristics were as follows: 74% female, 75% post-pubertal, 36% Hispanic, 38% White, 22% Black, 4% Asian, and 64% free/reduced lunch participants with a mean age of 15.5 (SD, 0.7). Forty one percent of the participants were obese (BMI ≥ 95th percentile); 54% were abdominally obese (waist to height ratio ≥ 0.5). Multivariable general linear models were used to estimate the association between the independent variables (school night sleep duration, free night sleep duration, midpoint of sleep (corrected), social jetlag, and morningness/eveningness) and the dependent variables (BMI z scores and waist to height ratios). Social jetlag positively associated with BMI z scores (p < 0.01) and waist to height ratios (p = 0.01). Midpoint of sleep (corrected) positively associated with waist to height ratios (p = 0.01). After adjusting for social jetlag, school night sleep duration was not associated with waist to height ratios or BMI z scores. Morningness/eveningness did not moderate the association between sleep duration and BMI z scores. Findings from this study suggest that chronobiological approaches to preventing and treating obesity may be important for accelerating progress in reducing obesity rates in adolescents.

The addition of medications is associated with a significant increase in risk of falls in elderly patients, regardless of drug class. Further studies are needed to assess the possible increased risk of falls with increasing number of medications.

Objective-To assess contributing factors to increased obesity risk, by comparing children with autism spectrum disorder (ASD), developmental delays/disorders, and general population controls in weight status, and to examine associations between weight status and presence of co-occurring medical, behavioral, developmental, or psychiatric conditions across groups and ASD severity among children with ASD. Study design-The Study to Explore Early Development is a multisite cross-sectional study of children, 2-5 years of age, classified as children with ASD (n = 668), children with developmental delays/disorders (n = 914), or general population controls (n = 884). Using an observational cohort design, we compared the 3 groups. Children's heights and weights were measured during a The authors declare no conflicts of interest.

Sleep is a complex behavior with numerous health implications. Identifying socio-demographic and behavioral characteristics of sleep are important for determining those at greatest risk for sleep-related health disparities. In this cross-sectional study, general linear models were used to examine socio-demographic and behavioral characteristics associated with sleep duration, chronotype, and social jet lag in adolescents. One hundred fifteen participants completed Phase I (self-reported sleep measures); 69 of these participants completed Phase II (actigraphy-estimated sleep measures). Black adolescents had shorter free night sleep than Hispanics. Youth with later chronotypes ate fewer fruits and vegetables, drank more soda, were less physically active, and took more daytime naps. Based on these findings, recommendations for individual support and school policies are provided.

PurposeDespite growing evidence supporting the potential benefits of higher end-tidal carbon dioxide (ETCO2) levels in surgical patients, there is still insufficient data to formulate guidelines for ideal intraoperative ETCO2 targets. As it is unclear which intraoperative ETCO2 levels are currently used and whether these levels have changed over time, we investigated the practice pattern using the Multicenter Perioperative Outcomes Group database.MethodsThis retrospective, observational, multicentre study included 317,445 adult patients who received general anesthesia for non-cardiothoracic procedures between January 2008 and September 2016. The primary outcome was a time-weighted average area-under-the-curve (TWA-AUC) for four ETCO2 thresholds (< 28, < 35, < 45, and > 45 mmHg). Additionally, a median ETCO2 was studied. A Kruskal-Wallis test was used to analyse differences between years. Random-effect multivariable logistic regression models were constructed to study variability.ResultsBoth TWA-AUC and median ETCO2 showed a minimal increase in ETCO2 over time, with a median [interquartile range] ETCO2 of 33 [31.0–35.0] mmHg in 2008 and 35 [33.0–38.0] mmHg in 2016 (P <0.001). A large inter-hospital and inter-provider variability in ETCO2 were observed after adjustment for patient characteristics, ventilation parameters, and intraoperative blood pressure (intraclass correlation coefficient 0.36; 95% confidence interval, 0.18 to 0.58).ConclusionsBetween 2008 and 2016, intraoperative ETCO2 values did not change in a clinically important manner. Interestingly, we found a large inter-hospital and inter-provider variability in ETCO2 throughout the study period, possibly indicating a broad range of tolerance for ETCO2, or a lack of evidence to support a specific targeted range. Clinical outcomes were not assessed in this study and they should be the focus of future research.Electronic supplementary materialThe online version of this article (10.1007/s12630-018-1249-1) contains supplementary material, which is available to authorized users.