Running on Empty: Of Hypopinealism and Human Seasonality

The pineal hormone melatonin is the natural transducer of the environmental light–dark signal to the body. Although the responsiveness to photoperiod is well-conserved in humans, only about 25 percent of the human population experiences seasonal changes in behavior. As a consequence, humans seem to have adapted—at least partly—to the seasonal changes in day length. The aim of the study was to demonstrate that the individual melatonin deficit marker DOC (degree of pineal calcification) is related to variation of seasonal phenomena in humans. Out of 3,011 patients in which cranial computer tomography (cCT) was performed for diagnostic reasons, 97 consecutive “healthy” subjects (43 female, 54 male; age 18–68 yrs, mean ± SD: 35.0 ± 13.1) were included. Exclusion criteria were pathological finding in cCT, acute/chronic illness including alcohol/drug abuse, shift work, and medication, which are known to influence melatonin excretion. The degree of pineal calcification (DOC) was semiquantitatively determined using the previously validated method. The Seasonal Pattern Assessment Questionnaire (SPAQ) was performed in a telephone interview. Twenty-six subjects fulfilled the criteria for seasonal affective disorder (SAD) or subsyndromal (S) SAD. Seasonality was more pronounced in women than in men (SPAQ seasonality score: 7.8 ± 4.0 vs. 4.9 ± 4.5; p = 0.001) and negatively and significantly associated with age (r = −0.178; p = 0.04). The subjective sleep length significantly varied between seasons (one-way repeated measures ANOVA: F = 45.75; p < 0.0001), with sleep during winter being 53 min (±70 min) longer than during summer. Controlling for age, the total seasonality score was negatively and significantly associated with DOC (r94 = −0.214; p = 0.036). Data confirm earlier studies with respect to distribution of seasonality with sex and age. The survival of seasonality in the sleep length of people living in an urban environment underlines functionality of the circadian timing system in modern societies. Moreover, data confirm for the first time that diminished experience of seasonality in behavior is associated with a reduced individual capacity to produce melatonin.

Sleep and Depressive Symptoms in the Morningness/Eveningness-Suicidal Ideation Relationship Depend on School Shift in Mexican Adolescents

The aim was to analyze the morningness/eveningness (M/E) effect on suicidal ideation through sleep and depressive symptoms mediators with school shift (i.e., morning and afternoon) as moderator. In this study, 586 Mexican adolescents, with a mean age of 16.31 ± 0.92, from a public high school in a double-shift school system (298 from the morning shift and 288 from the afternoon shift) participated. Measurements of sleep, morningness/eveningness (circadian preference), depressive symptomology, and suicidal ideation were completed. Adolescents in the afternoon shift reported a later rise time, bedtime, greater time in bed sleep length, and less social jet lag than in the morning shift. Considering the moderated-mediated analysis, circadian preference and suicidal ideation were mediated by both depressive symptoms and school day’s sleep length in the morning shift. In the afternoon shift, no mediation effect was significant. When weekend sleep length was considered in the model, only depressive symptoms had a mediating effect between circadian preference and suicidal ideation in the morning shift; no significant mediating effect was found on the afternoon shift. The results suggest that an afternoon school schedule may act as a protective factor for the adolescent’s mental health and may represent a viable option for future interventions.

Is There a Dose-Response Relationship between Acute Physical Activity and Sleep Length? A Longitudinal Study with Children and Adolescents Living in Sweden

A declining physical activity (PA) and sleep in children and adolescents have been observed during the previous decades. PA could benefit sleep, but the findings are mixed. The aim of the present study was to examine if there is a dose-response relationship between time spent in acute moderate and vigorous physical activity (MVPA) and sleep length in children and adolescents. Additional aims were to examine if the sleep length is higher for children and adolescents who conduct at least an average of 60 min in MVPA/day and to study differences between sex and school years. The study population consists of 262 participants in school year 5 (aged 11 years), 7 (aged 13 years), and 9 (aged 15 years). Accelerometers measured MVPA while sleep diaries measured sleep length. A linear and longitudinal mixed effect linear regression was conducted to study the primary aim. The secondary aims were studied with linear regressions. Included confounders were sex, school year, school stress, screen time, menstruation onset, family household economy, and health status. A stratified regression for sex and school year was conducted. The linear regression showed no statistically significant findings in the crude or adjusted model. The stratified linear regression found a significant positive association for girls but a negative association for school year 5. No associations were found in the longitudinal regression or when comparing sleep length for participants that did and did not spend an average of at least 60 min in MVPA/day. A dose-response relationship was found in the stratified linear regression, implying a possible weak association. The statistically non-significant differences between participants that did and did not spend an average of at least 60 min in MVPA/day implies that spending an average of at least 60 min in MVPA/day may not be associated with a higher mean sleep length.

Gut microbiota alterations in response to sleep length among African-origin adults

Sleep disorders are increasingly being characterized in modern society as contributing to a host of serious medical problems, including obesity and metabolic syndrome. Changes to the microbial community in the human gut have been reportedly associated with many of these cardiometabolic outcomes. In this study, we investigated the impact of sleep length on the gut microbiota in a large cohort of 655 participants of African descent, aged 25–45, from Ghana, South Africa (SA), Jamaica, and the United States (US). The sleep duration was self-reported via a questionnaire. Participants were classified into 3 sleep groups: short (<7hrs), normal (7-<9hrs), and long (≥9hrs). Forty-seven percent of US participants were classified as short sleepers and 88% of SA participants as long sleepers. Gut microbial composition analysis (16S rRNA gene sequencing) revealed that bacterial alpha diversity negatively correlated with sleep length (p<0.05). Furthermore, sleep length significantly contributed to the inter-individual beta diversity dissimilarity in gut microbial composition (p<0.01). Participants with both short and long-sleep durations exhibited significantly higher abundances of several taxonomic features, compared to normal sleep duration participants. The predicted relative proportion of two genes involved in the butyrate synthesis via lysine pathway were enriched in short sleep duration participants. Finally, co-occurrence relationships revealed by network analysis showed unique interactions among the short, normal and long duration sleepers. These results suggest that sleep length in humans may alter gut microbiota by driving population shifts of the whole microbiota and also specific changes in Exact Sequence Variants abundance, which may have implications for chronic inflammation associated diseases. The current findings suggest a possible relationship between disrupted sleep patterns and the composition of the gut microbiota. Prospective investigations in larger and more prolonged sleep researches and causally experimental studies are needed to confirm these findings, investigate the underlying mechanism and determine whether improving microbial homeostasis may buffer against sleep-related health decline in humans.

Longer Work Shifts, Faster Forward Rotation—More Sleep and More Alert in Aircraft Inspection

The purpose of this intervention study is to compare sleep, alertness, and work ability among aircraft inspectors working under two different shift schedules. The original schedule was forward rotating: MMM – – EEE – NNN – – – (M = morning, E = evening, N = night, – = day off). The new schedule was fast forward rotating: MEN – – with 10-h shifts. The baseline data were collected before the schedule changed, and the follow-up data 12 months (n = 10, Group A) or 5 months (n = 13, Group B) after the change. Three of subjects were women and average age was 46.6 years (range 31–58). The surveys included questions on sleep quantity, sleep quality, severe sleepiness, alertness, perceived stress, current work ability, and satisfaction with the shift schedule. The results indicated that in the new schedule, the sleeping times were longer and sleep loss was less. Moreover, shift specific severe sleepiness decreased, and alertness during shifts improved. Compared to baseline, perceived stress was lower and work ability was better. Satisfaction with the shift system had also improved. To conclude, the quickly forward rotating shift system might be beneficial in terms of increased sleep length and improved alertness and overall well-being especially among older aircraft inspectors.

Investigating sleep quality on an inpatient psychiatry ward

AimsSleep is essential for optimal physiological functioning, but often interrupted in hospital settings. Disturbed sleep is associated with relapse of mood disorders and multiple comorbidities including impaired immunological function and increased cardiovascular risk. There are unique environmental challenges on psychiatry wards, such as overnight monitoring. Recent studies highlight the importance of evaluating and managing inpatient sleep disturbance. Aims include exploring the extent to which patients’ sleep is impacted by inpatient admission, elucidating causes of sleep disturbance and determining ways to improve sleep during admission.MethodPatients aged 18–65 years, who consented and were expected to be inpatients for a week, were approached after 72 hours of admission (n = 35). Quantitative and qualitative data, including on pre-hospital and hospital sleep quantity and quality, were gathered, as part of a cohort characterisation. Questionnaires using Pittsburgh Sleep Quality Index elements were used to gather data. Offering earplugs as a sleep-aid intervention was implemented, with sleep quantity and quality reassessed 72 hours post-intervention. In response to feedback, sound monitoring at regular intervals overnight was undertaken using a decibel-metre to determine noise baseline and variation.ResultAll patients approached agreed to participate. Pre-hospital average sleep quantity was 5.2 hours, with restedness score of 4.3, and 71% patients rating their sleep as ‘bad’. After 72 hours post-admission, average sleep length was 6.5 hours and restedness 5.3. Of patients who accepted earplugs (59%), there were improvements to mean sleep quality and quantity (7.6 hours), with 86% patients rating earplugs helpful. All patients surveyed thought that earplugs should be offered routinely on admission. 70% of patients were prescribed benzodiazepines or z-drugs as required. Self-reported factors affecting sleep included noise, psychiatric symptoms and medication side effects, with 13 patients mentioning the former. Sound monitoring recorded an average decibel level with a range of 35–75 dB, with peaks reaching 95 dB.ConclusionPoor sleep in hospital is widespread. There is a need to understand and address modifiable environmental and ward factors implicated in sleep disturbance within inpatient settings. Pharmacological options for sedation are common, but it is important to focus on alternative options of low-cost, non-pharmacological interventions which promote sleep optimisation and enhance inpatient care.

110 Physiological correlates of the Epworth Sleepiness Scale reveal different dimensions of daytime sleepiness

Introduction The Epworth Sleepiness Scale (ESS) is used as a clinical tool for determining excessive daytime sleepiness. However, the behavior and biology that underlie ESS scores remain to be elucidated. The main objective of this analysis is to determine objective behavioral and physiologic correlates of the ESS. Secondarily, we examine the relationship of the ESS to parallel subjective and objective endpoints that could represent measures of daytime sleepiness. Methods Using two separate machine learning algorithms, Random Forest and Lasso, we determined the association between ESS scores and 55 sleep and medical variables in individuals who participated in the Sleep Heart Health Study (N=2105). These variables include self-reported sleep characteristics (e.g., habitual sleep length and latency, frequency of not getting enough sleep), polysomnographic sleep measures from a single night, medication use, and mental and physical health status. Additional analyses were conducted on data stratified by age and gender. To investigate the relationship between ESS and other measures of daytime sleepiness, cross-correlation analysis was conducted on the ESS and five variables that could analog daytime sleepiness (feeling unrested, nap duration and frequency, sleep latency, frequency of not getting enough sleep). Results Analysis of the main dataset resulted in low explained variance (7.15 - 10.0%), with self-reported frequency of not getting enough sleep as most important predictor (10.3–13.9% of the model variance). Stratification by neither age nor gender significantly improved explained variance. Habitual sleep length was not an important predictor in any model. Cross-correlational analysis revealed low correlation of other daytime sleepiness measures to ESS score. Conclusion Data analyses indicate that ESS scores are not well explained by habitual or polysomnographic sleep values, or a variety of other biomedical characteristics. This suggests that there are different, potentially orthogonal dimensions of the concept of “daytime sleepiness” that may be driven by different aspects of sleep physiology. Caution should be used when considering the ESS as a clinical measure given that the physiologic correlates still remain to be elucidated. Support (if any):

Sleep Disturbances in Children With Autism Spectrum Disorder at a Malaysian Tertiary Hospital

Introduction: Children with autism spectrum disorder (ASD) have a variety of co-morbid medical problems, including sleep disturbances. Prevalence of sleep disorders has been reported to be higher in this group as compared to the general population. Identifying sleep problems in children with ASD may help increase awareness and improve the overall quality of care for them. The aim of this study was to determine the prevalence of sleep problems and associated factors in a group of Malaysian children aged 6–16 years, with ASD.Method: This is a cross-sectional study at the Child Development Centre of UKM Medical Centre (UKM MC) on ASD children aged 6–16 years. Demographic data was obtained and the Sleep Disturbances Scale for Children (SDSC) questionnaire was completed by the main caregiver. Logistic regression analysis was used to determine factors related to higher total SDSC scores.Results: A total of 128 patients were recruited (111 boys) with a median age of 8 years 3 months (IQR: 2 years 10 months). Forty-seven (36.7%) of them obtained total SDSC scores in the pathological range with 19 (14.8%) scoring high for overall disturbances and 28 (21.9%) for at least one subtype of sleep disorders: 25 (19.5%) DIMS, 18 (14.1%) SBD, 10 (7.8%) DOES, 5 (3.9%) DOA, 6 (4.7%) SWTD, and 3 (2.3%) SHY. More than half of the children (57.8%) were reported to have sufficient sleep duration of 8–11 h, but longer sleep latency of at least 15 min (82.8%). Half of the ASD children also had co-morbidities in which one-third (34.4%) had attention-deficit hyperactivity disorder (ADHD). Using logistic regression analysis, four factors were significantly associated with higher total SDSC scores; female gender (p = 0.016), older age group (11–16 years old) (p = 0.039), shorter sleep length (p = 0.043), and longer sleep latency (p &lt; 0.001).Conclusion: The prevalence of sleep disturbances is high among Malaysian children with ASD, especially DIMS. Female gender, older age group, shorter sleep length, and longer sleep latency were found to be associated with the sleep disturbances. Evaluation of sleep problems should form part of the comprehensive care of children with ASD.