Time for bed! Earlier sleep onset is associated with longer nighttime sleep duration during infancy

Objective/backgroundClinical recommendations include putting infants to bed using a consistent bedtime routine at an appropriate hour to promote longer nighttime sleep. Actigraphy was used in this exploratory study to examine how bedtime routines and nighttime sleep onset were associated with nighttime total sleep time (TST) and efficiency from 6 to 24 weeks of age.Patients/methodsInfants (n = 24) wore sleep actigraphs for three, one-week periods at 6, 15, and 24 weeks of age. Nighttime TST, sleep efficiency, sleep onset and offset were quantified. Mothers reported on infant bedtime routines using the Brief Infant Sleep Questionnaire at each age. Multilevel models examined between- and within-person associations.ResultsAs infants aged, sleep onset was earlier, and bedtime routines became shorter (p's < 0.05). Infants fell asleep between 7 and 8:00PM on 24% of the nights. Most mothers (70%) reported that they often fed infants to sleep for the night. For every 1 h earlier in infants' usual sleep onset, nighttime TST was 34.4 min longer that night (p < 0.01). Infants with earlier than usual sleep onset had slightly earlier sleep offset the next morning (8.4 min for every 1 h earlier in onset; p = 0.02). Between-person analyses showed similar patterns. Infants with a more consistent bedtime routine and who were not typically fed to sleep at bedtime had longer nighttime TST at 6 weeks, with a trend or no association at later ages.ConclusionInfants who fell asleep earlier also slept longer at night. Keeping infants up later in hopes of them sleeping in longer may be counterproductive.     

Acupuncture treatment of a male patient suffering from long-term schizophrenia and sleep disorders

Objective

To investigate the effectiveness of acupuncture in the treatment of chronic schizophrenia and co-morbid sleep disorders.

Work–rest pattern,alertness and performance assessment among naval personnel deployed at sea: A cross sectional study

BackgroundThe combat naval vessels require continuous operational preparedness for guarding the vast coastline. Sailors onboard these ships are at risk for sleep deprivation. Sailors may be vulnerable to chronic fatigue; and decreased performance, vigilance, and cognitive functioning owing to sleep debt, which may affect safety during tactical operations and while transportation of ships. In this study we assessed the work-rest pattern and level of alertness during sailing and non sailing days.MethodsThirty-two male participants maintained a 24-h sleep and activity log for 5 days. Furthermore, qualitative gross motor activity was recorded using an actiwatch during these 5 days. Participants also completed four test sessions of personal digital assistant (PDA) based psychomotor vigilance task (PVT) test: pre-sleep, post-sleep, pre-work, and post-work. A comparison of data was performed using the Wilcoxon signed-rank test.ResultsSailors received approximately 1 h less of rest while sailing. There was a significant difference in bedtime, wake-up time, total sleep time, sleep onset latency (SOL), wake up after sleep onset (WASO), and the number of awakenings during the non-sailing and the sailing days. PVT data showed significantly higher reaction times during the sailing days on pre-work and post-sleep sessions.ConclusionOur study shows that although the sailors are not getting sufficient restorative sleep while sailing as compared to non-sailing days, this is not affecting their cognitive functioning while working.     

A critical review on sleep assessment methodologies in athletic populations: factors to be considered

A growing body of research focus on athletes' sleep in order to investigate the effects of sleep in sports performance and recovery or the prevalence of sleep disorders in athletes. At the same time, several sleep monitoring tools have been developed and used in athletic populations for fulfilling these purposes. This review aimed to provide critical assessment to the most used by athletes' methodological approaches and compared them with the gold standard approach. Advantages and disadvantages of the various sleep monitoring tools were critically discussed. Literature related to aspects of athletes' sleep was reviewed. From the shortlisted studies, several factors that seem to affect sleep in athletes were identified using objective methods such as polysomnography/electroencephalography and actigraphy. These factors were associated to sleep (eg such as sleep environment, familiarization procedures and napping) and daily habits (eg nutrition, fluid consumption, alcohol and caffeine intake, tobacco use). The selected studies that evaluated sleep objectively were screened according the reporting rates of these variables. The majority of the screened studies were found to underreport these variables. Practical issues were addressed and recommendations about reporting sleep-related factors were made in order to improve studies’ quality assessment and allow for more robust comparisons between studies.     

Similarities and differences between actigraphy and parent-reported sleep in a Hispanic and non-Hispanic White sample

ObjectiveDespite concerns about the inaccuracy of parents' reports of children's sleep, it remains unclear whether the bias of parents' reports varies across racial/ethnic groups. To address this limitation, the current study systematically investigated the concordance among parent-reported sleep questionnaires, sleep diaries, and actigraphy-based sleep in a sample of Hispanic and non-Hispanic White children.MethodsParents of 51 Hispanic and 38 non-Hispanic White children (N = 89; M_age = 6.46, SD = 0.62; 50.6% male) reported their child's bedtime and wake time on school days using sleep diaries and questionnaires. Children's sleep also was assessed with actigraphy for five consecutive school days.ResultsParents reported longer sleep duration, earlier bedtime, and later wake time using sleep diaries and questionnaires compared to actigraphy-based assessments. Larger discrepancies between diaries and actigraphy of sleep duration, and between questionnaires and actigraphy of wake time were found in non-Hispanic White children, compared to Hispanic children.ConclusionsAlthough parents tended to overestimate their child's sleep as compared to actigraphy, parents of Hispanic children may be more accurate in some estimates of children's sleep than parents of non-Hispanic White children. Researchers, clinicians, and parents should be aware of the potential biases in parents' reports and estimates of their child's sleep and that the degree of bias could vary across racial/ethnic groups.     

Sleep assessment in aging adults with type 2 diabetes: agreement between actigraphy and sleep diaries

ObjectiveActigraphy and sleep diaries have been widely used to evaluate various sleep parameters. However, their agreement in diabetes patients remains unclear. The objective of this study was to examine the agreement between sleep outcomes measured by actigraphy and sleep diaries in aging adults with type 2 diabetes (T2D).MethodsA convenience sample of 53 T2D adults (aged 50–76 years) were enrolled. Participants wore a wrist ActiGraph and filled out a daily sleep diary for eight days. Total sleep time (TST), sleep efficiency (SE), sleep onset latency (SOL), and wake after sleep onset (WASO) were obtained from the actigraphy and sleep diaries. Bland–Altman plots were conducted to examine the agreement between each sleep outcome.ResultsThe differences for TST and SE assessed by actigraphy and sleep diaries were 11.3 min (SD 65.3) and 0.2% (SD 10.5). Bland–Altman plots revealed wide limits of agreement between actigraphy- and diary-measured TST (95%CI: −139.3 min, 116.7 min) and SE (95%CI: −20.9%, 20.4%). Systematic biases were present for WASO and SOL: compared to actigraphy, sleep diaries underestimated WASO and overestimated SOL. As the SOL and WASO increased, the agreement became lower.ConclusionOverall, the agreement between actigraphy and sleep diaries is poor across all measures in aging adults with T2D patients. Findings from this study highlight the need for sleep researchers and clinicians to consider the method used for sleep assessment when developing interventions or interpreting study findings.     

Tryptophan-enriched cereal intake improves nocturnal sleep, melatonin, serotonin, and total antioxidant capacity levels and mood in elderly humans

Melatonin and serotonin rhythms, which exhibit a close association with the endogenous circadian component of sleep, are attenuated with increasing age. This decrease seems to be linked to sleep alterations in the elderly. Chrononutrition is a field of chronobiology that establishes the principle of consuming foodstuffs at times of the day when they are more useful for health, improving, therefore, biorhythms and physical performance. Our aim was to analyze whether the consumption of cereals enriched with tryptophan, the precursor of both serotonin and melatonin, may help in the reconsolidation of the sleep/wake cycle and counteract depression and anxiety in 35 middle-aged/elderly (aged 55–75 year) volunteers in a simple blind assay. Data were collected for 3 weeks according to the following schedule: The control week participants consumed standard cereals (22.5 mg tryptophan in 30 g cereals per dose) at breakfast and dinner; for the treatment week, cereals enriched with a higher dose of tryptophan (60 mg tryptophan in 30 g cereals per dose) were eaten at both breakfast and dinner; the posttreatment week volunteers consumed their usual diet. Each participant wore a wrist actimeter that logged activity during the whole experiment. Urine was collected to analyze melatonin and serotonin urinary metabolites and to measure total antioxidant capacity. The consumption of cereals containing the higher dose in tryptophan increased sleep efficiency, actual sleep time, immobile time, and decreased total nocturnal activity, sleep fragmentation index, and sleep latency. Urinary 6-sulfatoxymelatonin, 5-hydroxyindoleacetic acid levels, and urinary total antioxidant capacity also increased respectively after tryptophan-enriched cereal ingestion as well as improving anxiety and depression symptoms. Cereals enriched with tryptophan may be useful as a chrononutrition tool for alterations in the sleep/wake cycle due to age.     

Sleep Patterns of School-Age Children with Asperger Syndrome or High-Functioning Autism

Sleep patterns of 32 school-age children with Asperger syndrome (AS) and high-functioning autism (HFA) were compared to those of 32 typically developing age- and gender-matched children, using parent survey and one week of diary and actigraphic monitoring. Parents of children with AS/HFA more commonly reported that their children had difficulty falling asleep. One week of sleep recording with diary and actigraphy confirmed that children in the AS/HFA group spent a longer time awake in bed before falling asleep than children in the control group, possibly because the children in the AS/HFA group had earlier bedtimes. Other essential aspects of sleep patterns coincided between the groups. The sleep patterns of children with AS and HFA did not differ.     

Sleep actigraphy pattern and behavioral/emotional difficulties in kindergarten children: Association with hypothalamic-pituitary-adrenocortical (HPA) activity

Background

Various studies of adult endocrinology and sleep show close connections between poor sleep quality, deterioration of the HPA axis and negative psychological characteristics. However, the extent to which these associations may have already emerged and developed in childhood remains unclear.

Methods

A total of 82 preschoolers (age 4.91 ± 0.48) underwent activity monitoring for seven consecutive days and nights, wearing a digital movement-measuring instrument. Additionally, on the first and on the last morning of sleep registration, the activity of the HPA axis was assessed via the amount of cortisol in the saliva. Psychological and behavioral assessments were also made.

Results

Three sub-groups of good (22%), normal (58.5%) and poor (19.5%) sleepers were distinguished. Poor sleep patterns were associated with higher HPA activity and with behavioral/emotional difficulties.

Conclusions

The interplay between unfavorable sleep patterns, deterioration of the HPA axis and behavioral/emotional difficulties is already apparent in pre-school children.