Discover the most talked about and latest scientific content & concepts.

Concept: Bedtime


To determine whether preschool-aged children with earlier bedtimes have a lower risk for adolescent obesity and whether this risk reduction is modified by maternal sensitivity.

Concepts: Bedtime


Teenagers need sufficient sleep to function well daily, yet consolidated evidence advising which factors protect, or harm, adolescents' sleep is lacking. Forty-one studies, published between 2003 and February, 2014, were meta-analysed. Mean weighted r values were calculated to better understand the strength of protective and risk factors for 85,561 adolescents' (age range = 12-18 y) bedtime, sleep onset latency (SOL) and total sleep time (TST). Results showed good sleep hygiene and physical activity were associated with earlier bedtimes. Video gaming, phone, computer and internet use, and evening light related to delayed bedtimes. Good sleep hygiene negatively correlated with sleep latency. Alternatively, sleep latency lengthened as a negative family environment increased. Tobacco, computer use, evening light, a negative family environment and caffeine were associated with decreased total sleep, whereas good sleep hygiene and parent-set bedtimes related to longer sleep length. Good sleep hygiene appears to be protective, whereas a negative home environment and evening light appear to be risk factors. Cautious use of technology (other than television), caffeine, tobacco and alcohol should be considered. These factors, along with pre-sleep worry, are likely to have some negative impact on sleep. Parent-set bedtimes and physical activity may be beneficial. Future research directions are discussed.

Concepts: Sleep, Adolescence, The Adolescents, Sleep onset latency, Bedtime


This study examined the association between electronic media use and sleep among preschoolers, using a national sample of 402 mothers of 3- to 5-year-olds. Participants completed an online survey assessing preschoolers' electronic media use, bedtime and wake time, sleep time, napping behaviors, and sleep consolidation. Results showed that heavier television use and tablet use, both overall and in the evening, were associated with later bedtimes and later wake times, but not with fewer hours of sleep, providing evidence for a time-shifting process. In addition, heavier daily television use and evening smartphone use were associated with increased daytime napping. Moreover, heavier daily television use, daily and evening smartphone use, and evening tablet use were associated with poorer sleep consolidation, suggesting less mature sleep patterns. These findings indicate that media effects on the timing of sleep and the proportion of sleep that occurs at night are important to consider when assessing the health risks of electronic media on children.

Concepts: Sleep, Circadian rhythm, Media, Mass media, Koi Kaze, Electronic publishing, Bedtime


We explored the relations among young children’s mobile media use, sleep, and a form of self-regulation, temperamental effortful control (EC), among a national sample of 402 mothers who completed an online survey. We found that the relation between mobile media use and EC was moderated by children’s sleep time. Tablet use was negatively related to EC only among children who slept less at night (40% of our sample). However, hand-held game player use was positively related to EC among children who slept longer at night (60% of our sample). In addition, sleep quality was a mediator in the relation between evening tablet use and EC. Evening use related to later bedtimes, more bedtime resistance, and worse sleep duration, and these indicators of poor sleep quality, in turn, predicted weaker EC. Statement of contribution What is already known on this subject? Young children are spending increasing amounts of time with mobile media, such as tablets and hand-held game players. Media exposure is related to children’s self-regulation. Media exposure is related to children’s sleep quality. What does this study adds? Number of sleep hours moderates the relation between mobile media use and EC among young children. Tablet time is negatively related to EC among young children who get fewer sleep hours. Hand-held game playing is positively related to EC among young children who get greater sleep hours. Sleep quality mediates the relation between evening tablet time and EC among young children.

Concepts: Sleep, Circadian rhythm, Mediation, Tablet, Tablet PC, Sleep hygiene, Dextroamphetamine, Bedtime


The aim of the current study was to examine the longitudinal relationship between bedtimes and body mass index (BMI) from adolescence to adulthood in a nationally representative sample.

Concepts: Mass, Body mass index, The Current, Bedtime


Lack of adherence to continuous positive airway pressure therapy (CPAP) limits the effectiveness of treatment of obstructive sleep apnea (OSA). We hypothesized that an irregular bedtime would be negatively related to regular use of CPAP treatment. If so, modifying bedtime schedule may address the persistent problem of inconsistent CPAP use in adults with OSA. In a prospective longitudinal study, we examined whether inconsistent self-reported bedtime before initiation of CPAP treatment, operationalized as bedtime variability, was (1) different among those adherent (≥4 hours per night) and non-adherent to CPAP treatment at 1 week and 1 month; and/or (2) was related to 1-week and 1-month CPAP use when other variables were accounted for. Consecutively recruited newly diagnosed OSA adults (n = 79) completed sleep diaries prior to CPAP treatment. One-week and 1-month objective CPAP use data were collected. Pre-treatment bedtime variability was different among CPAP non-adherers and adherers at 1 month and was a significant predictor of non-adherence at 1 month in multi-variable analyses. The odds of 1-month CPAP non-adherence were 3.5 times greater in those whose pre-treatment bedtimes varied by >75 minutes. Addressing sleep schedule prior to CPAP initiation may be an opportunity to improve CPAP adherence. © 2014 Wiley Periodicals, Inc.

Concepts: Longitudinal study, Sleep, Sleep apnea, Polysomnography, Obstructive sleep apnea, Variable, Address space, Bedtime


Fasting and postprandial triglyceride concentrations largely depend on dietary and lifestyle factors. Alcohol intake is associated with triglycerides, but the effect of alcohol on diurnal triglyceridemia in a free living situation is unknown. During three days, 139 men (range: 18-80 years) measured their own capillary triglyceride (cTG) concentrations daily on six fixed time-points before and after meals, and the total daily alcohol intake was recorded. The impact of daily alcohol intake (none; low, <10 g/day; moderate, 10-30 g/day; high, >30 g/day) on diurnal triglyceridemia was analyzed by the incremental area under the cTG curve (∆cTG-AUC) reflecting the mean of the six different time-points. Fasting cTG were similar between the alcohol groups, but a trend of increased cTG was observed in men with moderate and high alcohol intake after dinner and at bedtime (p for trend <0.001) which persisted after adjustment for age, smoking and body mass index. The ∆cTG-AUC was significantly lower in males with low alcohol intake (3.0 ± 1.9 mmol·h/L) (n = 27) compared to males with no (7.0 ± 1.8 mmol·h/L) (n = 34), moderate (6.5 ± 1.8 mmol·h/L) (n = 54) or high alcohol intake (7.2 ± 2.2 mmol·h/L) (n = 24), when adjusted for age, smoking and body mass index (adjusted p value < 0.05). In males, low alcohol intake was associated with decreased diurnal triglyceridemia, whereas moderate and high alcohol intake was associated with increased triglycerides after dinner and at bed time.

Concepts: Human, Metabolism, Mass, Triglyceride, Body mass index, Bedtime