Sleep timing, chronotype and social jetlag: Impact on cognitive abilities and psychiatric disorders

Meal scheduling corrects obesogenic diet induced-uncoupling of cortico-hippocampal activities supporting memory

BACKGROUND

Highly caloric food consumed around the clock perturbs the metabolism and cognitive functioning. We hypothesised that obesogenic food could alter neuronal representations of memory depending on the feeding-fasting cycle.

METHODS

We tracked memory performance, dendritic spine dynamics and neuronal representations of memory in C57Bl6J mice fed obesogenic food ad libitum from peri-adolescence. We aimed to correct energy rich diet-induced plasticity deficits and cognitive impairment with time-restricted feeding in males and females. We further used chemogenetics, pharmacology and knock-in mice to investigate functional correlates underlying diet-induced neurocognitive impairments.

FINDINGS

We found that changes in the feeding-fasting cycle reverted the effects of ad libitum obesogenic food on memory impairment in both sexes (n = 55, p = 0.003). Concurrently, it also corrected the increased dendritic spine maintenance and neuroactivity in hippocampus and the decreased spine maintenance and activity in parietal cortex (n = 48, p < 0.005). Bi-directional effects in cortex and hippocampus mediated by glucocorticoid signalling are causal to behavioural changes (n = 91, p = 0.0008), and scaling hippocampal with cortical activities restored memory in mice fed obesogenic food (n = 44, p = 0.02).

INTERPRETATION

These results indicate that meal scheduling is a promising approach to confront glucocorticoid signalling bias and memory deficits caused by obesogenic food.

FUNDING

Agence Nationale de la Recherche (ANR-21-CE14-0086), Fondation pour la Recherche sur le Cerveau (FRC).

Development and validation of a prediction model for the depressive symptom risk in commercial airline pilots

Background/aims

Shift workers, such as medical personnel, and pilots, are facing an increased risk of depressive symptoms. Depressive symptoms significantly impact an individual's quality of life and affect work performance, decision-making abilities, and overall public safety. This study aims to establish a multidimensional depressive symptom prediction model based on a large sample of commercial airline pilots to facilitate early identification, prevention, and personalized intervention strategies.

Methods

This population-based study included 11,111 participants, with 7918 pilots in the training set and 3193 pilots in the external validation set. Depressive symptom severity was assessed using the Patient Health Questionnaire-9 (PHQ-9). Physiological, psychological, and lifestyle factors potentially associated with depressive symptom risk were collected. The optimal predictors for model development were selected using the Boruta algorithm combined with the LASSO method, and a nomogram was developed using multivariate logistic regression to predict depressive symptoms in pilots. The model performance was evaluated using Receiver Operating Characteristic (ROC) curves, calibration curves, and accuracy measures, such as the Brier score and Spiegelhalter z-test. Additionally, decision curve analysis (DCA) was performed to assess the model's clinical utility.

Results

A total of 7918 pilots were included in the training set and 3193 were included in the external validation set. Five characteristic indicators were selected based on their significance in the prediction of depressive symptom risk: living status, alcohol drinking, family history of mental health disorder, subjective health, and subjective sleep quality. The model showed acceptable overall discrimination (AUCtrain = 0.836, 95%CI 0.818 to 0.854; AUCvalidation = 0.840, 95%CI 0.811 to 0.868) and calibration (Brier scoretrain = 0.048; Brier scorevalidation = 0.051). The decision curve analysis showed that the net benefit was superior to intervening on all participants or not intervening on all participants.

Conclusions

This study provides a reliable tool for early prediction and customized management of depressive symptoms among commercial airline pilots. This approach promotes the development of the field by transitioning from passive mental health care to active mental health prevention, emphasizing personalized prevention strategies.

The role of the DSM-5 maladaptive personality traits in adherence to sleep hygiene behaviors and sleep duration

Recent research explores the associations between maladaptive personality constructs proposed by the DSM-5 Alternative Model of Personality Disorders (AMPD) and general psychopathology whereas research on sleep hygiene behaviors and sleep duration is poor. This study first aimed to classify an adult population based on bedtime, mobile phone use before bedtime, and sleep duration. The second aim was to compare the AMPD trait domains including negative affectivity, detachment, antagonism, disinhibition, and psychoticism across the derived clusters. The cross-sectional study consisted of 481 college students from the west of Iran (mean age of 27.7 ± 6.8 years; 69.4% female). Several single items plus the Brief Form of Personality Inventory for DSM-5 were used for data collection. A hierarchical cluster analysis was performed to determine latent categories, and the AMPD domain scores between the clusters were compared using multivariate analysis of variance and post hoc tests. The cluster analysis identified three categories containing a vulnerable group (poor sleep hygiene behaviors but sufficient sleep duration), an unhealthy group (poor sleep hygiene behaviors plus insufficient sleep duration), and a healthy group (good sleep hygiene behaviors plus sufficient sleep duration). The results showed that the clusters significantly differed in all trait domains (except for detachment) and the total average score with higher mean scores, especially for the unhealthy cluster. Our findings highlight the meaningful impact of maladaptive personality traits on unhealthy sleep hygiene behaviors and insufficient sleep. Preventive medicine can identify at-risk populations by screening for maladaptive personality in early adulthood.

The association of chronotype on depression in adolescents: the mediating role of sensation seeking and sleep quality

OBJECTIVES

This study explores the relationships among chronotype, sensation seeking, sleep quality and depressive symptoms in adolescents with diagnosed depression, aiming to clarify the mechanisms by which chronotype is associated with depression.

METHODS

This cross-sectional study assessed 216 adolescents with diagnosed depression using a demographic questionnaire, the Morningness-Eveningness Questionnaire, the Sensation Seeking Scale, the Pittsburgh Sleep Quality Index, and the Beck Depression Inventory. Descriptive and correlational analyses were performed using SPSS 27.0, and structural equation modeling was conducted via AMOS to explore the mediating roles of sensation seeking and sleep quality in the relationship between chronotype and depression.

RESULTS

The study found that 60.6% of adolescents with depression were evening chronotypes. Evening chronotype was associated with higher sensation seeking (r = -0.134, p < 0.05), poorer sleep quality (r = -0.303, p < 0.01), and more severe depressive symptoms (r = -0.376, p < 0.01). Chronotype showed a direct effect on depressive symptoms (effect size = -0.318, 95% CI = -0.602 to -0.049, p < 0.05) and an indirect effect via sleep quality, accounting for 80.5% of the total effect. While sensation seeking alone was not a significant mediator, it contributed to a chain mediation with sleep quality, accounting for 13% of the total effect (combined effect size = -0.053, 95% CI = -0.163 to -0.005, p < 0.01).

CONCLUSIONS

Chronotype may play a significant role in adolescent depression, with both direct and indirect effects mediated by sleep quality and sensation seeking. The findings highlight the potential importance of sleep quality as a mediating factor, indicating that interventions targeting sleep improvement could be a promising avenue for further exploration in alleviating depressive symptoms in adolescents.

Identifying novel protein biomarkers with cross-psychiatric disorders effects and potential intervention targets: Evidence from proteomic-Mendelian randomization

Plasma proteins are the potential therapeutic targets for psychiatric disorders due to their important roles in signal transduction. We aimed to explore the plasma protein biomarkers with cross-psychiatric disorders effects. Proteome-wide Mendelian randomization (MR) and colocalization analyses were performed to investigate the potential causal relationship between plasma protein biomarkers and 12 psychiatric disorders and further identify the potential proteins with cross-effects. To assess the directionality and exclude potential reverse causation, Steiger directionality tests and reverse MR analyses were additionally conducted. Then, validation analysis was performed by employing summary data from cross-psychiatric disorder GWAS to validate the cross-psychiatric effects of proteins. Protein-protein interactions were conducted to evaluate the interaction between candidate proteins and druggability assessment was used to prioritize potential drug targets for psychiatric disorders. We identified novel plasma proteins that possessed cross-psychiatric disorder effects, especially BTN2A1 and BTN3A2 associated with major depressive disorder (MDD), schizophrenia (SCZ), and bipolar disorder (BIP); ITIH1, ITIH3, ITIH4 and FES associated with SCZ and BIP, and the cross-effects of these proteins on SCZ and BIP were confirmed by validation analyses. Steiger tests and reverse MR supported causal directionality. Besides, the protein-protein interactions (PPI) analysis indicated cross-effects proteins had significant interaction, especially ITIH1-ITIH3. The druggability assessment prioritized eight proteins, two of which (ITIH3 and NCAM1) has been targeted by antipsychotic drugs. Our findings provided insights into shared biological mechanisms underlying these conditions.

[Screening for sleep disorders in internal medicine as potential comorbidities of systemic autoimmune diseases and improving patients' quality of life]

Sleep medicine and internal medicine share a global and transdisciplinary vision of human physiology and illnesses, with an approach guided by the complaint and semiology. In France, approximately 13 to 18 million individuals suffer from a sleep disorder: these disorders therefore represent a public health problem. Their comorbidities with systemic autoimmune diseases are frequent. As such, this article suggests an approach to screening for sleep disorders in daily clinical practice of internal medicine leading, when appropriate, to request specialized diagnostic and/or therapeutic care in sleep medicine to substantially improve patients' quality of life.

Too early for inhibitory control? ERP evidence for social jetlag in evening chronotypes across three domains of distraction

Young adults are frequently evening chronotypes due to their circadian rhythm, making their late sleep-wake cycles vulnerable to the misalignment with socially imposed early schedules, a phenomenon known as social jetlag. This misalignment leads to sleep deprivation and has been identified as a risk factor for poor academic performance. Understanding the relationship between social jetlag and inhibitory control is crucial, since academic achievement relies on inhibitory control, the ability to maintain and pursue a goal while inhibiting goal-irrelevant information. In this event-related potential study, we examined the impact of social jetlag on inhibitory control across three domains of distraction: Self-generated information, perceived environment, and habits. Each distraction domain was assessed using a well-established cognitive task: n-back, flanker, and global-local task, respectively. We assessed the relationship between social jetlag, task performance, and neural activity in young male adults who self-identified as evening chronotypes. Results provide evidence for an association between social jetlag and early conflict monitoring (N2 component), but not later inhibition monitoring (P3 component). Specifically, increased N2 amplitudes at the non-optimal time of day were found in the absence of behavioral differences. Future studies need to confirm whether this finding reflects compensatory neural mechanisms to maintain stable performance despite increased sleep pressure. Highlighting the multifaceted nature of inhibitory control, the relationship between social jetlag and inhibitory control varied by distraction domain, with associations in the n-back task and the congruent global-local task condition, but not the flanker task.

Evening Chronotype Associates With Worse Physical and Mental Health and Headache-Related Disability Among Migraine Patients

Migraine has been linked to chronotype, but with mixed results. Here, we tested chronotype in association with physical and mental health and headache characteristics in a large database of migraine patients and controls. A sample of the UK Biobank (n = 360,081; 58.3% female, mean age: 56.38) was used. Data included self-reported chronotype, mental (neuroticism, depression, stress) and physical (body fat percentage, overall health rating) health factors, and migraine diagnosis based on ICD-10 G43 diagnosis from healthcare data. Morning type controls (Cmorning, n = 210,775), evening type controls (Cevening, n = 129,174), morning type migraine patients (Mmorning, n = 12,194), and evening type migraine patients (Mevening, n = 7938) were compared. Additionally, in a subsample of questionnaire-based migraine (n = 15,356), chronotype was tested in association with headache-related features. One-way ANOVA, Kruskal-Wallis test and chi-squared test were run in SPSS 28 with Bonferroni correction. Evening chronotype was more frequent among migraine patients with an OR = 1.06, 95% CI [1.03; 1.09] compared to controls (χ2 = 16.523, p < 0.001). The Mevening group showed the worst level of all mental and physical health variables, while the Cmorning group reported the best values. Migraine patients with morning or evening chronotype showed a highly similar headache symptom profile, but the Mevening subgroup expressed a higher disability (t = -3.965, p < 0.001). In conclusion, evening chronotype was associated with the worst physical and mental health status and the highest headache-related disability among migraine patients, suggesting a need for elevated medical attention on chronotype in migraine.

Chronotype and synchrony effects in human cognitive performance: A systematic review

Chronotype is a proxy for various intra-individual rhythms (e.g. sleep-wake cycles) which fluctuate throughout the day. The extent to which chronotype modulates cognitive performance remains unclear. Here, we systematically reviewed studies to determine the influence of chronotype on its own, and/or in interaction with time of day (ToD; optimal/non-optimal), in cognitive function in healthy adults. Following PRISMA guidelines, data searches were conducted in PubMed and Web of Science databases (11 March 2024), yielding 65 studies (53 in adults aged 18-45 y; 11 comparing adults aged 18-32 and 50-95 y; one involving only morning type adults aged 60-76 y). Most of the reviewed studies (>80%) indicated no main effect of chronotype on cognitive function. There was evidence from 29 (45.31%) of 64 studies involving adults aged 18-45 y of a synchrony effect (i.e. superior performance at optimal ToD) in morning and/or evening types, mostly in attention, inhibition, and memory. In older adults, there was evidence of a synchrony effect from 10 (83.33%) of 12 studies, especially on tasks involving fluid abilities. Limited evidence suggested higher activation of inhibition-related brain regions at optimal ToD in both chronotypes, and synchrony effects being impacted by certain exogenous factors known to affect arousal and performance (e.g. task complexity, lighting conditions). Our findings highlight the need to carefully consider age along with endogenous and exogenous sources of intra-individual variations in arousal while determining synchrony effect in cognitive functions. Not acknowledging these synchrony effects may also result in exaggerated cognitive deficits especially in the elderly.

The effect of alcohol on subsequent sleep in healthy adults: A systematic review and meta-analysis

Alcohol is commonly consumed prior to bedtime with the belief that it facilitates sleep. This systematic review and meta-analysis investigated the impact of alcohol on the characteristics of night-time sleep, with the intent to identify the influence of the dose and timing of alcohol intake. A systematic search of the literature identified 27 studies for inclusion in the analysis. Changes in sleep architecture were observed, including a delay in the onset of rapid eye movement (REM) sleep and a reduction in the duration of REM sleep. A dose-response relationship was identified such that disruptions to REM sleep occurred following consumption of a low dose of alcohol (≤0.50 g∙kg-1 or approximately two standard drinks) and progressively worsened with increasing doses of alcohol. Reductions in sleep onset latency and latency to deep sleep (i.e., non-rapid eye movement stage three (N3)) were only observed following the consumption of a high dose of alcohol (≥0.85∙g kg-1 or approximately five standard drinks). The effect of alcohol on the remaining characteristics of sleep could not be determined, with large uncertainty observed in the effect on total sleep time, sleep efficiency, and wake after sleep onset. The results of the present study suggest that a low dose of alcohol will negatively impact (i.e., reduce) REM sleep. It appears that high doses of alcohol may shorten sleep onset latency, however this likely exacerbates subsequent REM sleep disruption. Future work on personal and environmental factors that affect alcohol metabolism, and any differential effects of alcohol due to sex is encouraged.

Clinical physiology of circadian rhythms: A systematic and hierarchized content analysis of circadian questionnaires

Circadian rhythms are near-24 h patterns of physiology and behavior associated with several physical and mental health outcomes. Self-report questionnaires are routinely used and practical tools to assess circadian rhythms. However, the extent to which these questionnaires capture the relevant parameters and can be used interchangeably is unknown. We investigated different types of circadian manifestations using 14 circadian self-report questionnaires for adults. A systematic and hierarchical content analysis was combined with a visualization method. Jaccard indices were calculated to quantify the degree to which the questionnaires overlapped. Content analysis revealed 40 distinct manifestations, which we classified into five dimensions ("circadian phase," "circadian amplitude and stability," "nycthemeral timing," "nycthemeral regularity," and "circadian complaints"). The average Jaccard index was 0.150, indicating very weak content overlap. None of the 14 questionnaires explored all five dimensions. The Composite Scale of Morningness and the Morningness-Eveningness Questionnaire exhibited greater, but still limited, overlap with the other questionnaires (Jaccard indices of 0.255 and 0.251, respectively), and are the best instruments for assessing the circadian phase. Nycthemeral timing, which must be analyzed to measure the circadian misalignment in clinical and research settings, is only explored by the Munich Chronotype Questionnaire, but that instrument does not evaluate circadian amplitude and stability and only partially assesses nycthemeral regularity. Based on our preliminary analysis, we make recommendations regarding the circumstances in which some circadian questionnaires could prove more useful than the others. The results might also aid the definition and investigation of circadian health at the crossroads of physiology and behavior.

SleepInvestigatoR: a flexible R function for analyzing scored sleep in rodents

Analyzing scored sleep is a fundamental prerequisite to understanding how sleep changes between health and disease. Classically, this is accomplished by manually calculating various measures (e.g. percent of non-rapid eye movement sleep) from a collection of scored sleep files. This process can be tedious and error-prone, especially when studies include large animal numbers or involve long recording sessions. To address this issue, we present SleepInvestigatoR, a versatile tool that can quickly organize and analyze multiple scored sleep files into a single output. The function is written in the open-source statistical language R and has a total of 25 parameters that can be set to match a wide variety of experimental needs. SleepInvestigatoR delivers a total of 23 unique measures of sleep, including all measures commonly reported in the rodent literature. A simple plotting function is also provided to quickly graph and visualize the scored data. All code is designed to be implemented with little formal coding knowledge, and step-by-step instructions are provided on the corresponding GitHub page. Overall, SleepInvestigatoR provides the sleep researcher a critical tool to increase efficiency, interpretation, and reproducibility in analyzing scored rodent sleep.

Mindfulness mediates the association between chronotype and depressive symptoms in young adults

BACKGROUND

Chronotype influences risk of depression, with evening-types at higher risk, although the reasons for this are uncertain. Potential mediating factors include mindfulness, sleep quality, rumination, and alcohol consumption, but research is lacking.

METHODS

We explored the role of these factors in the association between chronotype and depressive symptoms amongst young adults, using cross-sectional data collected from a university student sample (N =  546).

RESULTS

Evening-types had significantly higher levels of depression symptoms, poorer sleep quality, and lower levels of 'acting with awareness' and 'describing', as well as higher rumination and alcohol consumption. Mediation analyses demonstrated that the link between chronotype and depression was fully mediated by 'acting with awareness', 'describing', sleep quality, and alcohol consumption.

LIMITATIONS

Only subjective measures were employed, and due to the cross-sectional design, no causal inferences can be made.

CONCLUSION

The mediation results shed light on the crucial role of specific mindfulness facets, sleep, and alcohol consumption for explaining why evening types are at higher risk of depression; findings have import for potential interventions aiming to reduce depression risk amongst young adults in particular.

Mediating Effects of Sleep Problems and Emotional Symptoms in the Relationship Between Chronotype and Self-Harm Among Adolescents Aged 11-19 Years

Purpose

Self-harm is linked to numerous adverse health and social outcomes, including repetitive self-harm and an increased risk of suicide. This study aims to explore the influence of chronotype on self-harm among adolescents and further investigate the mediating role of sleep problems and emotional symptoms.

Participants and Methods

The study was conducted between April and June 2022, involving 13 junior and senior high schools in Tianjin. The participants were asked to complete online questionnaires assessing chronotype, sleep problems, depression, anxiety, and self-harm. The data were analyzed and processed using Spearman correlation and mediation effect analysis. Two mediation pathways were tested: Model 1 with sleep problems and depression as the mediators, and Model 2 with sleep problems and anxiety as the mediators.

Results

Participants comprised 13,374 Chinese middle school adolescents (6745 boys) aged 11-19 years. In Model 1, the independent mediation effects of sleep problems and depression were -0.216 (95% CI = [-0.263, -0.172]) and -0.101 (95% CI = [-0.121, -0.083]), accounting for 33.33% and 15.59% of the total effect, respectively. The chain mediation effect was -0.170 (95% CI = [-0.196, -0.146]), accounting for 26.23% of the total effect. In Model 2, the independent mediation effects of sleep problems and anxiety were -0.232 (95% CI = [-0.279, -0.189]) and -0.075 (95% CI = [-0.091, -0.059]), respectively accounting for 35.63% and 11.52% of the total effect. The chain mediation effect was -0.151 (95% CI = [-0.176, -0.128]), accounting for 23.20% of the total effect.

Conclusion

Chronotype is a significant predictor of self-harm, with a later chronotype associated with a higher risk. Both sleep problems and emotional symptoms independently and serially mediate the relationship between chronotype and self-harm. These findings highlight the complex pathways through which chronotype influences self-harm behavior and suggest potential targets for intervention.

Joint association of sleep onset time and sleep duration with depression in patients with chronic kidney disease: Insights from the NHANES 2015-2020

Background

The prevalence of depression among patients with chronic kidney disease (CKD) is high and closely related to poor prognosis. However, the association between sleep onset time, sleep duration, and depression in CKD patients has not been thoroughly studied.

Methods

This study utilized cross-sectional data from CKD patients who participated in the National Health and Nutrition Examination Survey from 2015 to 2020, analyzing their sleep onset time, sleep duration, and Patient Health Questionnaire-Nine. Logistic regression models and restricted cubic spline models were used to explore the association between sleep onset time, sleep duration, and depression in CKD patients.

Results

A total of 2141 CKD patients aged 20 and above were included in this study, among whom 246 (11.5 %) had depression. Compared to those reporting optimal sleep onset (22:00-23:59) and sufficient sleep duration (7-8 h), CKD patients with late sleep onset (≥24:00) and either insufficient (<7 h) or excessive (≥9 h) sleep had a significantly higher risk of depression, with adjusted OR of 2.03 (95 % CI:1.29-3.19) and 2.07 (95 % CI:1.07-4.00), respectively. Additionally, the association between sleep onset time, sleep duration, and depression showed a U-shaped pattern, with the inflection point for sleep onset time at 23:00 and for sleep duration at 7.5 h.

Conclusion

Inappropriate sleep onset time and sleep duration are significantly associated with depression in CKD patients. This association may be important to consider in clinical practice for the prevention and management of depressive symptoms in CKD patients.

Associations between multiple sleep dimensions and suicide and non-suicidal self-injury: a cross-sectional study of 3828 Chinese young people

PURPOSE

Suicide and non-suicidal self-injury (NSSI) are preventable concerns in young people. Suicidal ideation (SI), suicidal plans (SP) and suicidal attempt (SA) are closely related to death. Sleep problems are known risk factors for suicide and NSSI. This study aimed to explore the relationship between sleep, suicidality and NSSI.

METHODS

Participants were 3,828 middle school and college students aged 11-23 years from urban and rural areas of Henan Province. Sleep, suicidal phenomena and NSSI were assessed by applying self-reported questionnaires. Chi-squared tests were utilized to demonstrate the demographic data and sleep variables. The correlation between sleep, suicidality and NSSI were explored by using binary logistic regression, while adjusting socio-demographic characteristics with multivariate models.

RESULTS

Sleep variables except mid-sleep time were related to suicidal phenomena (P < 0.05). Greater social jet lag (SJL) [≥ 2 h (h)] was associated with increased risk of SI [Odds ratios (OR) = 1.72, 95% confidence intervals (CI):1.40-2.11], SP (OR = 2.10, 95%CI:1.59-2.79) and SA (OR = 1.50, 95%CI:1.00-2.26). Non-only child participants with SJL (≥ 2 h) had significantly increased odds of SI (OR = 1.75, 95%CI: 1.41-2.18) and SP (OR = 2.25, 95%CI: 1.66-3.05). Eveningness chronotype had the strongest correlation with SI (OR = 3.87, 95%CI:2.78-5.38), SP (OR = 4.72, 95%CI:2.97-7.50), SA (OR = 6.69, 95%CI:3.08-14.52) and NSSI (OR = 1.39, 95%CI:1.02-1.90).

CONCLUSION

Overlong or short sleep duration, SJL, eveningness chronotype and other sleep abnormalities (e.g., daytime dysfunction, low sleep efficiency) were associated with a higher prevalence of SI, SP and SA. Additionally, eveningness was significantly correlated with NSSI among young people. These findings suggested the importance of assessing and intervening in sleep habits to prevent suicide and NSSI in young people.

Nutraceutical Blends Promote Weight Loss, Inflammation Reduction, and Better Sleep: The Role of Faecalibacterium prausnitzii in Overweight Adults-A Double-Blind Trial

This study explores the effects of a nutraceutical blend with prebiotics, β-glucans, essential minerals, and silymarin on gut microbiota, inflammation, and sleep quality in obesity through microbiota reshaping and metabolic improvements over 90 days. A double-blind, randomized trial was conducted on 77 participants divided into two groups receiving either a standard nutraceutical blend (NSupple) or a silymarin-enriched blend (NSupple_Silybum). Fecal and plasma samples were collected at baseline and post-supplementation for gut microbiota, metabolic, and inflammatory marker analysis. The results showed a reduction in body weight, waist-to-height ratio, total cholesterol, and fractions in the NSupple_Silybum group. There was a dysbiosis recovery shown by the increase in beneficial gut bacteria, such as Lentisphaerae phylum, Lactobacillus and Faecalibacterium genera, and Faecalibacterium prausnitzii in the NSupple group, with a concurrent reduction in Adlercreutzia and Sutterella in the NSupple_Silybum group. Both groups demonstrated improved inflammatory profiles by the reduced TNF-α/IL-10 ratio, reduced cortisol levels, and reduced Firmicutes/Bacteroides ratio. Additionally, improvements in sleep quality were associated with reductions in pro-inflammatory cytokines and improved microbiota composition. The nutraceutical blend reshaped gut microbiota, enhanced anti-inflammatory species, and improved metabolic and sleep parameters, highlighting its potential as a nutritional strategy for managing obesity and reducing inflammation.

Patients reported outcome of cognitive function scale: a psychometric evaluation

BACKGROUND

Assessment of cognitive function is essential to identify the impact of brain aging, disease or injury on individuals. The Short Form Cognitive Function Scale is a brief instrument, easy to use in clinical and research settings with simple interpretation. However, its psychometric properties have not been confirmed in the general Mexican population. The aim of this study was to determine the psychometric properties of the Short Form Cognitive Function Scale in the general Mexican population.

METHODS

An instrumental design was conducted with 600 participants. Analyses were performed to evaluate factor structure (exploratory and confirmatory factor analysis), reliability (internal consistency), measurement invariance, construct validity (convergent and divergent) and Know-Groups Validity.

RESULTS

A unifactorial structure of 8 items was verified with an internal consistency of α = 0.945 and a McDonald Omega index of Ω = 0.946. Measurement invariance was confirmed (ΔCFI & TLI ≤ 0.01; ΔRMSEA & SRMR ≤ 0.015), with respect to gender, age groups and geographic area of residence. Finally, the Short Form Cognitive Function Scale showed adequate convergent validity with the Subjective Well-Being variable (r =.507, p <.001), divergent with the GAD 5 (r = -.517, p <.001), and discriminant between younger and older participants (t = -5.304, p <.001).

CONCLUSIONS

The Short Form Cognitive Function Scale version for the general Mexican population presented adequate psychometric properties that make it a valid and reliable instrument for use in non-clinical and research settings in Mexico.

Prevalence of social jetlag and associated factors in Brazilian adolescents: Results from a country-wide cross-sectional study

OBJECTIVES

Social jetlag is a disturbance in the circadian rhythm caused by a desynchronization between an individual's biological rhythm and social commitments and responsibilities. It leads to sleep debt during the week and compensation on weekends. Social jetlag is associated with an increased risk of chronic diseases and cognitive dysfunction in adolescents. This study aims to assess the prevalence of social jetlag and associated factors in Brazilian adolescents.

METHODS

Adolescents of both sexes, aged between 12 and 17years, participating in the Study of Cardiovascular Risks in Adolescents (ERICA), were included. The sleep duration on a typical weekday and weekend day was collected through a self-reported questionnaire. The occurrence of social jetlag was defined as the difference between the midpoint of sleep on weekends and weekdays, with differences equal to or higher than 1hour considered as an indicator of positive social jetlag. Factors associated with the prevalence of social jetlag were investigated using Poisson regression models.

RESULTS

The sample included a total of 64,029 adolescents. Social jetlag affects more than 80% of Brazilian adolescents, with higher prevalence among girls in the age group of 16-17years, with white skin color, attending private schools, and those having morning classes. Additionally, unhealthy risk behaviors such as skipping breakfast, alcohol consumption, and increased screen time are associated with a higher prevalence of social jetlag.

CONCLUSION

The prevalence of social jetlag was high in Brazilian adolescents, and, among its associated factors, studying in the morning shift and engaging in unhealthy risk behaviors stand out.

Could sleep be a brain/cognitive/neural reserve-builder factor? A systematic review on the cognitive effects of sleep modulation in animal models

The brain/cognitive/neural reserve concept suggests that lifelong experiences, from early life through adulthood, make the brain more resilient to neuronal damage. Modifiable lifestyle factors, such as sleep, can support the development and enhance such a reserve, helping to counteract age- or disease-related brain changes and their impact on cognition. Sleep plays a crucial role in cognitive functioning, and disruptions or disorders may increase neurodegenerative risks. This systematic review aims to explore how functional and disturbed sleep impacts cognitive functions and neuromorphological mechanisms in rodents, aiming to better understand its role in brain/cognitive/neural reserve development. This systematic review, registered on PROSPERO (ID: CRD42023423901) and conducted according to PRISMA-P guidelines, searched PubMed, Scopus, Web of Science, and Embase databases for studies up to June 2022, with terms related to sleep, rodents, and cognitive functions. Of the 28,666 articles identified, 142 met the inclusion criteria. Main results showed significant cognitive decline after sleep deprivation, especially in memory performance. These findings supports the importance of sleep as a critical factor in modulating brain/cognitive/neural reserve.

Changes in delayed sleep patterns and related clinical factors in a social restriction environment

We aimed to investigate which factors, including socioenvironmental factors and emotional regulation, were associated with pronounced delayed sleep patterns during the COVID-19 social restriction. We evaluated 744 adults aged 20-65 y using a web-based survey with a self-reported questionnaire in May 2022. Based on the survey, we estimated the mid-sleep time on free days corrected for oversleeping on free days (MSFsc) and social jet lag (SJL). We determined delayed sleep patterns using ΔMSFsc, which was defined as the difference between MSFsc during the pre- and mid-pandemic. The high-risk group for delayed sleep patterns (H-DSP) group was younger with evening person and had more severe insomnia, depression with rumination, and smartphone addiction (p < 0.05). Logistic regression revealed that stronger tendencies to express emotions and rumination were independent risk factors associated with a pronounced pattern of delayed sleep during the pandemic. In the H-DPS group, SJL increased even more during the pandemic. In socially restricted environments, emotion regulation significantly affects the severity of delayed sleep patterns, and people with H-DSP also had more disrupted circadian rhythms. Therefore, active education of sleep hygiene and emotional support with psychological interventions are needed in socially restricted environments.

Sleep-wake patterns of fencing athletes: a long-term wearable device study

Objective

Sleep is the most efficient means of recovery for athletes, guaranteeing optimal athletic performance. However, many athletes frequently experience sleep problems. Our study aims to describe the sleep-wake patterns of fencing athletes and determine whether factors, such as sex, competitive level and training schedules, could affect the sleep-wake rhythm.

Methods

Sleep data from 23 fencing athletes were collected using the Huawei Band 6, monitoring key sleep parameters such as bedtime, wake time, duration of deep and light sleep, wake periods, REM sleep duration, and nap duration. During this period, athletes were required to wear the band continuously for 24 hours daily, except bathing, charging, and competition times.

Results

Athletes averaged 7.97 hours of sleep per night, with significant differences observed in wake time (p = 0.015) and midpoint of sleep (p = 0.048) between high-level and low-level athletes, as well as a higher frequency of naps among high-level (χ2 = 11.97, p = 0.001) and female (χ2 = 3.88, p = 0.049) athletes. Nap duration was negatively correlated with night sleep duration (r =  - 0.270, p < 0.001). Athletes were observed for changes in sleep-wake patterns from Monday to Sunday. On Mondays, Wednesdays, and Fridays, when there was no morning training, the athletes' wake-up time and the midpoint of sleep were shifted significantly backward, and there were significant differences in sleep parameters between training days and rest days.

Conclusion

The sleep patterns of athletes differ according to level and gender. The sleep-wake patterns of athletes are influenced by training schedules, indicating the presence of sleep rhythm disruption.

Examining sex differences in morningness-eveningness and inter-individual variability across years of age: A cross-sectional study

This study investigated the impact of age on morningness-eveningness (ME) and its inter-individual variability, with a focus on sex-specific patterns. A sample of 2890 participants aged 12-94 years (55.85% female) completed the Composite Scale of Morningness. Multiple linear regression analyses revealed a significant Age × Sex interaction, indicating distinct age-dependent patterns for males and females in both ME and its inter-individual variability. We conducted segmented regression analyses to explore these dynamics further and identify breakpoints. Eveningness increased across adolescence, with both males and females reaching peak lateness at 20 years. Morningness increased thereafter until 64.94 years for females and until 59 years for males. Following these sex-specific breakpoints, morningness remained constant for females and increased at a reduced rate for males. After the age of 48, males exhibited greater morningness than females. Inter-individual variability in ME (VME) changed with age, increasing until 33 years for men and 36.80 years for women, followed by a decrease for both sexes. From 50.30 years onward, females showed greater VME compared to men. This study suggests that ME and VME shift across age, and differences between sexes were observed from middle age onwards. Diurnal preferences are likely influenced by internal and environmental variables.

Association of self-monitoring performance of cognitive performance with personal diurnal preference when sleep-deprived

In modern society, many workers struggle with sleep deprivation due to their work schedules and excessive workloads. Accurate self-awareness and self-monitoring abilities are crucial for workers to adopt risk-coping strategies and protective behaviors when fatigued. The current study examined the relationship between chronotypes and self-monitoring performance during 24 h of sleep deprivation. The study involved 26 male adults in a two-night experiment, and participants' diurnal preferences were evaluated using the Morningness-Eveningness Questionnaire (MEQ). Self-monitoring performance was calculated by comparing actual task performance with self-rated predicted or post-estimated performance in the psychomotor vigilance task (PVT) and Digit Symbol Substitution Task (DSST). The study found that task and self-monitoring performances in the PVT and DSST were maintained until around 4:00 h, after which they began to deteriorate. Individuals with a higher MEQ score, indicating a stronger tendency towards a morning type, showed inaccurate self-monitoring, particularly in the final quarter of the sleep deprivation experiment, due to overly optimistic predictions. However, only prediction accuracy and not post-estimation showed this correlation. This study highlights the importance of considering an individual's chronotype in workplace management, particularly in workplaces with irregular work timings, rotating shifts, and long working hours, to ensure better occupational safety.

The Role of Timing and Amount of Outdoor Play in Emotional Dysregulation in Preschool Children

BACKGROUND

Currently, the time children spend playing outdoors is at an all-time low. However, the existing literature suggests that outdoor play may have cognitive and emotional benefits for children.

METHODS

The present study carried out a mediation analysis to explore whether amount and timing of outdoor play affects children's emotion regulation and whether working memory mediates these relations among 325 preschool children (Mage = 4.19, SD = 0.85) residing in a large Midwestern city in the United States.

RESULTS

Results showed that greater amounts of outdoor play very early (i.e., wake-up to noon) and very late (i.e., 6 PM to bedtime) in the day were related to greater emotional dysregulation. By contrast, greater amount of outdoor play from noon to 6 PM was related to lower emotional dysregulation. Importantly, the effect of amount of outdoor play from noon to 6 PM on emotion regulation was fully mediated by working memory.

CONCLUSION

The findings of the present study suggest that in early childhood outdoor play that supports children's circadian rhythms may have cognitive and, in turn, emotional benefits.

The Role of Chronotypes and Perceived Stress on Sleep Quality in Undergraduates in Taiwan

INTRODUCTION

Chronotypes and perceived stress can predict psychiatric symptoms and affect sleep quality, though the relationships between these factors are not completely described. This study explores the influence of chronotypes and perceived stress on sleep quality among undergraduates.

METHODS

An online survey was administered to a convenience sample of 110 undergraduates aged 18-23 years (mean age 20.32 ± 1.00) at a university in southern Taiwan, predominantly women and senior students. Three self-reporting instruments were used: the Munich Chronotype Questionnaire, the Perceived Stress Scale, and the Pittsburgh Sleep Quality Index. Multivariate regression analysis was performed to investigate the influence of chronotype and perceived stress on sleep quality in undergraduates.

RESULTS

Sixty-one per cent of the respondents were poor-quality sleepers. Moreover, 85.5% of the respondents were classified as "neither" chronotype, whereas 13.6% were "evening" chronotype. Sleep quality was associated with both chronotype and perceived stress level (r = 0.41, 0.43, p < 0.01). Multiple regression revealed higher MCTQ scores (continuous or categorical) and higher perceived stress were significantly associated with poorer sleep quality, explaining approximately 30% of the variance (p < 0.001).

CONCLUSIONS

The findings of this study showed evening-type undergraduates with higher perceived stress exhibited poorer sleep quality. Highlight the importance of considering chronotype in health promotion among individuals transitioning to adulthood. Early interventions may help align an individual's chronotype with their external time schedule, mitigate the negative impacts of misaligned later chronotypes, enhance sleep quality, and help to manage perceived stress levels in undergraduates.

Sleep patterns in adolescents and associations with substance use

OBJECTIVES

Good sleep during adolescence is crucial for maintaining physical and psychological health; however, sleep disturbance during this period may contribute to health risks, such as substance use. This study aimed to identify the latent sleep patterns across male and female adolescents, and their association with drug use.

METHOD

A cross-sectional study was conducted involving 1391 high school students (aged 15-17; 56.4% female). Participants completed the brief Pittsburgh Sleep Quality Index alongside other sleep measures, and the Timeline Follow-Back and Drug Use History Questionnaire to measure substance use. A multiple-group latent class analysis was used to identify sleep patterns across sexes, and pairwise Logistic Regression models to compare their association with substance use.

RESULTS

Four sleep patterns were identified with varying degrees of sleep difficulties: "Good Sleep" (43.3%), "Night Awakenings" (31.8%), "Poor Efficiency and Sleep Onset" (9.4%), and "Poor Sleep" (15.5%). Female adolescents were more likely to belong to Poor Sleep and Poor Efficiency and Sleep Onset patterns, and male adolescents to Good Sleep. Likewise, binge drinking and using alcohol for a longer period were associated with experiencing Poor Efficiency and Sleep Onset (OR=1.03 and 2.3, respectively); smoking tobacco within the past month was linked to Night Awakenings (OR=2.2); and using cannabis or illegal drugs to the Poor Sleep pattern (OR=2.4 and 2.6, respectively).

CONCLUSIONS

Varied sleep difficulties exist among adolescents that significantly correlate with different aspects of drug use. Targeted interventions that address both sleep and drug prevention are recommended.

Exploring the relationships between chronotypes, attachment styles, and mental health in flight attendants

Circadian rhythm-related individual differences such as chronotypes (morningness/eveningness) are associated with mental health though not elucidated in circadian-disrupted populations such as flight attendants. International flight attendants (n = 288) aged 21 to 55 (70.8% female, 76.4% white) completed an online survey assessing chronotypes, attachment, depression, and anxiety to investigate the associations between these variables. Results showed a prevalence of intermediate (41.6%) and evening types (40.6%). Evening chronotype was associated with and significantly predicted depression but not anxiety. Individuals who scored higher in attachment anxiety or avoidance had higher levels of depression and anxiety. Exploratory mediation showed that attachment avoidance partially mediated the relationship between anxiety and depression. Overall, chronotypes and attachment are implied as transdiagnostic factors for mental health outcomes and highlighted using a Chrono-Attachment Health Model. Further research is needed to confirm these findings among flight attendants and shift workers.

Circadian rhythms and objective measures of physical activity among middle-aged and older adults in Taiwan

BACKGROUND

To identify the association between daytime activity with objectively monitor and subjective variables at a different time-zone of day as well as the sex differences.

METHODS

Participants aged 50 years and older living in the community in Taiwan were recruited. The activity was measured by wearable actigraphy devices, diaries, and self-reported questionnaires. The study used nonparametric analysis to examine the association between mean activity level and demographic and subjective measurement variables.

RESULTS

Among the 55 participants enrolled in the study, data of 34 (62 %) participants who meet the criteria that wore a wearable actigraphy device for at least 7 completed days were analyzed. There is no significant relationship between each demographics and subjective measurement variables. However, actigraphy counts are significantly related to female's nutrition (Z = -2.367, p = 0.017*), and male's retirement status (Z = -2.132, p = 0.033*).

CONCLUSIONS

The activity in morning is highest of the day with significant correlation to evening activities. Moreover, actigraphy counts that indicating objective measure of physical activity in female is significantly related to physiological variables (nutritional status), while male are predicted by social variables (retired status).

Association between screen time, homework and reading duration, sleep duration, social jetlag and mental health among Chinese children and adolescents

OBJECTIVES

To examine the associations of screen time, homework and reading duration, sleep duration, social jetlag with mental health in children and adolescents, as well as its gender differences.

METHODS

From December 2023 to April 2024, a total of 62 395 children and adolescents were selected from 51 schools in 17 cities of China by stratified cluster sampling. Screen time, homework and reading duration, sleep duration, and social jetlag were calculated by answering the questions about watching TV time, playing smartphones time, doing homework time, reading extracurricular books time, bedtime, wake-up time, and nap time during weekdays and weekends. Mental health was assessed by the Revised Mental Health Inventory-5 (MHI-5). The generalized linear model was used to determine the association between screen time, homework and reading duration, sleep duration, social jetlag, and mental health in children and adolescents.

RESULTS

The generalized linear model results showed that longer watching TV time, longer playing smartphones time, longer homework time, and greater social jetlag were correlated with poorer mental health in children and adolescents, while longer nighttime sleep duration, and longer daytime nap duration were correlated with better mental health. Moreover, in primary school and junior high school, we found that this association was stronger during the weekdays. However, in senior high school, this association was stronger during the weekends. After according to gender stratified, we found that the strength of this association was different in boys and girls at different study phases. Furthermore, our findings also revealed a significant quadratic relationship, indicating the association of better mental health with an optimal amount of sleep duration.

CONCLUSIONS

There was a significant association between screen time, homework and reading duration, sleep duration, social jetlag, and mental health in children and adolescents. This study has the potential to offer useful insights for the prevention and control of mental health issues in children and adolescents.

Using actigraphy to assess chronotype: Simpler is better

Actigraphy provides a unique method for objectively measuring sleep activity patterns, but confusion remains about how to use actigraphy data to determine chronotype. To determine the most suitable parameter, this study made a systematic comparison of actigraphy-derived parameters: the average midpoint of sleep of all record days (aMS-acti), cosine parameter (Bathyphase), and non-parametric parameter (L5-mid) in terms of the consistency with subjective chronotype parameters, test-retest reliability, and external validity. More importantly, we proposed multiple Munich Chronotype Questionnaire (MCTQ)-based actigraphy parameters: considering the difference between weekday (MSW-acti) with weekends (MSF-acti) and the sleep debt (MSFsc-acti). The study collected 5 days of actigraphy and scale data from 1,055 young adults, 138 of whom participated in the retest 2 years later. The results showed that, in terms of consistency with subjective chronotype, aMS-acti generally performed better than other actigraphy parameters. In addition, aMS-acti had the highest test-retest reliability and was more closely related to the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Self-Rating Depression Scale (SDS). The results suggest that the simplest parameter (aMS-acti) is superior to traditional cosine and non-parametric parameters and MCTQ-derived parameters for short-term assessment of chronotype.

Associations Among Social Jet Lag, Sleep-Related Characteristics, and Burnout of Nurses in Tertiary Hospitals

To investigate the status of social jet lag (SJL) through sociodemographic factors among clinical nurses and examine the correlation with burnout. There has been relatively little research on the possible factors resulting in SJL among nurses in China and its role in burnout. A multicenter cross-sectional study recruited 596 nurses from 7 Chinese hospitals. Online questionnaires were delivered to assess sociodemographics, shift work, SJL, chronotypes, and the burnout of nurses. Nurses had severe levels of SJL. The number of children, forms of employment, specialty area, length of professional service, and chronotypes were the main predictors of SJL. Moreover, SJL affected burnout (emotional exhaustion and deindividuation), and reducing the nurses' SJL could relieve their burnout. Additional evidence-based interventions indicate that reducing the SJL is essential as the nurses are suffering severe job burnout.

The interplay among sleep patterns, social habits, and environmental cues: insights from the Spanish population and implications for aligning daily rhythms

Introduction

The interplay among sleep patterns, social habits and environmental cues is becoming increasingly more important for public health and wellbeing due to its connection to circadian desynchronization. This paper explores said connections in Spain (which has an official and solar time mismatch), introducing the "Three Times Score" ‒which is based on questions widely used in the field‒ as a complementary tool for exploring the interplay of daily rhythms.

Methods

The questionnaire covers sleep-related habits, social time, and environmental time. The study includes 9,947 participants (34.89 ± 12.15 y/o, mean ± SD; 5,561 women) from different Spanish regions. Sleep parameters were obtained for work and free days, as well as a modified version of the sleep-corrected midsleep on free days (MBFbc) and a parameter similar to social jet lag, both derived from bed time rather than sleep time. A number of indexes were computed to compare bed and work-related habits, together with natural light/dark cycle, along with the Three Times Score. Mixed-effect regression analysis was used to test whether the biological, social and environmental factors included in the study significantly predicted the sleep-related parameters: bedtime, wake-up time, time in bed and mid-bedtime.

Results and discussion

Temporal differences were found between work and free days, with waking-up occurring 2 h earlier on work days (7:10 ± 0:01) than on free days (9:15 ± 0:01). Bed times were 1 h earlier on work days (23:46 ± 0:01) than on free days (00:45 ± 0:01), whereas time in bed was over 1 h shorter on work (7 h 23 min) versus free (8 h 29 min) days. Strong correlations were found between work starting time and waking-up and bedtimes on workdays. Women went to bed earlier and woke up later, spending more time in bed. Differences in sleep habits were observed between work and free days across all age groups. The group of younger adults (18-30) reported going to bed later than older and younger groups, especially on free days. Adolescents and young adults also woke-up later than other age groups, especially on free days. Social jet lag (relative to bed time) and desynchronization indexes also varied with age, with younger adult participants exhibiting higher levels. Seasonal differences were limited, with minor variations between winter and summer. According to the multiple regression analysis, social (day type, work start time, alarm clock usage), biological (age, gender, in most cases related to sex) and environmental (sunset time) factors significantly contribute to predicting sleep/bed related schedules. This study provides insights into sleep habits in the Spanish population, introducing the Three Times Score as a complementary tool for exploring the interactions between sleep/bed-related habits, natural darkness and work-related schedules. Understanding this interplay is crucial for developing tailored interventions to improve sleep and wellbeing.

How Late Nights Influence Brain Cortical Structures: Distinct Neuroanatomical Measures Associated With Late Chronotype in Young Adults

Chronotype is an inherent physiological trait reflecting an individual's subjective preference for their sleep awakening time, exerting a substantial influence on both physical and mental well-being. While existing research has established a close relationship between chronotype and individual brain structure, prior studies have predominantly focused on individual measurements of brain structural scales, thereby limiting the exploration of the underlying mechanisms of structural changes. This study seeks to validate previous research findings and enhance our understanding of the correlation between circadian rhythm preference and diverse cortical indicators in healthy young individuals. Magnetic resonance imaging (MRI) scans and chronotype assessments were conducted once for all participants, comprising 49 late chronotype (LC) young adults and 49 matched early chronotype young adults. The Chronotype Questionnaire was utilized to assess morningness and eveningness preferences. Surface-based analysis of structural MRI data revealed that LC young adults exhibited thinner cortical thickness of left pars orbitalis and lower cortical mean curve of right paracentral gyrus. Overall, this study represents a significant advancement in elucidating the connection between brain structure and function within the context of chronotypes.

Nutraceutical composition (yeast β-glucan, prebiotics, minerals, and silymarin) predicts improvement of sleep quality and metabolic parameters: A randomized pilot study

BACKGROUND & AIMS

The search for integrative and natural therapies that favor homeostasis to boost sleep and diet quality took place for young adult populations as a non-pharmacological strategy for long-term good quality of life. Thus, the present pilot study aims to investigate the effects of 90-day consumption of a nutraceutical composition on the neuro-immune-endocrine axis, providing better sleep quality and health improvement.

METHODS

For this, from March 2021 to June 2021, twenty-two Brazilian young adult volunteers (women and men) with BMI between 18.5 and 34.9 kg/m2 were divided into three distinct supplementation groups: NSupple; NSupple plus_S, and NSupple plus. Briefly, the supplement compositions included yeast β-glucan, prebiotics, and minerals in different concentrations associated or not with the herbal medicine silymarin. Neither nutritional nor physical activity interventions were performed during this pilot study period. The anthropometrics measures, questionnaires answer data, and harvest blood for metabolic, inflammatory, and hormonal tests were collected at baseline time (day zero-T0) and day 90 (T90) post-supplementation.

RESULTS

Our results highlight that the supplementation reduced body mass index (BMI), Waist-to-height ratio (WHtR), waist circumference, AST/ALT ratio, alkaline phosphatase, and HbA1c. Post-supplementation the IL-6 and IL-10 levels and the sleep, humor, and quality of life scores were suggested to improve. Sleep quality improvement seems to predict the reduction of adiposity-related body measures.

CONCLUSION

In sum, the nutraceutical supplementation might be related to anthropometric, metabolic, and endocrine parameters after 90 days reflecting on perception of humor, sleep, and life quality enhancement. However, it is important to recognize the limitation of the data presented considering that this was a pilot study.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT04810572 registered on 20th February 2021.

The association between chronotype profile and temporomandibular disorders among college students

BACKGROUND

Temporomandibular joint disorders (TMDs) are common in young adults, and the link between chronotype profile and TMDs is unclear.

OBJECTIVE

This study examined TMD prevalence and chronotype distribution and explored the relationship between chronotype and TMDs in young adults.

MATERIALS AND METHODS

A total of 663 students from Sichuan University completed questionnaires. Chronotype profiles were assessed using the Morningness-Eveningness Questionnaire, and TMDs were screened using the Fonseca Memory Index. To validate the findings, 68 TMD patients and 136 controls were enrolled.

RESULTS

The prevalence of TMDs was 69.7%, with significant differences among chronotype profiles. The intermediate profile was the most common chronotype. Eveningness profile was associated with higher TMDs prevalence and severity. Muscle pain and side movement difficulty scores were higher in eveningness and intermediate profiles. Female gender (OR 2.345; 95% CI 1.668-3.297) was a TMD risk factor, while morningness profile (OR 0.537; 95% CI 0.297-0.970) was protective. Validation with TMD patients and controls supported these findings, showing higher eveningness profile prevalence in the TMD groups.

CONCLUSIONS

TMDs have a high prevalence in college students, chronotype profiles shown to be associated with TMDs. Morningness is the protection factor in TMDs and PT, eveningness is a risk factor for IT.

The association between salivary IL-6 and poor sleep quality assessed using Apple watches in stressed workers in Japan

Insomnia is a major concern among stressed workers worldwide. Although stress generally has a detrimental effect on sleep quality, the impact of biological stress, especially the immunological stress response, on sleep quality is not yet fully understood. Stressed workers were recruited through a screening process using a Brief Job Stress Questionnaire. The participants were asked to complete various occupation-related questionnaires. Additionally, saliva samples were collected to assess interleukin-6 (IL-6) levels as an immunological stress response. Subsequently, they were asked to wear an Apple Watch to record their sleep pattern for one week. Their sleep architecture was estimated using a previously published and validated method. Finally, data from 73 participants were analyzed. Our multivariable analysis revealed that shorter durations of slow-wave sleep (non-rapid eye movement sleep stage 3) were significantly associated with elevated IL-6 levels (p = 0.005) and greater daytime sleepiness (p = 0.002) after controlling for total sleep time. Our finding that a higher immunological stress response is associated with poor sleep quality contributes to a better understanding of insomnia in stressed workers and emphasizes the importance of stress management in this population.

Early morning hour and evening usage habits increase misinformation-spread

Social media manipulation poses a significant threat to cognitive autonomy and unbiased opinion formation. Prior literature explored the relationship between online activity and emotional state, cognitive resources, sunlight and weather. However, a limited understanding exists regarding the role of time of day in content spread and the impact of user activity patterns on susceptibility to mis- and disinformation. This work uncovers a strong correlation between user activity time patterns and the tendency to spread potentially disinformative content. Through quantitative analysis of Twitter (now X) data, we examine how user activity throughout the day aligns with diurnal behavioural archetypes. Evening types exhibit a significantly higher inclination towards spreading potentially disinformative content, which is more likely at night-time. This knowledge can become crucial for developing targeted interventions and strategies that mitigate misinformation spread by addressing vulnerable periods and user groups more susceptible to manipulation.

Association between Life's Essential 8 and cognitive function among older adults in the United States

The American Heart Association (AHA) recently redefined cardiovascular health (CVH) with the introduction of Life's Essential 8 (LE8), which encompasses eight areas (diet, physical activity, nicotine exposure, sleep duration body mass index, non-HDL cholesterol, blood glucose, and blood pressure). This study aimed to explore the relationships between both the aggregate and individual CVH metrics, as defined by Life's Essential 8, and cognitive function in older adults in the United States. This cross-sectional, population-based study analyzed data from the National Health and Nutrition Examination Survey conducted between 2011 and 2014, focusing on individuals aged 60 years and older. CVH was categorized as low (0-49), moderate (50-79), or high (80-100). Cognitive function was assessed through the CERAD tests, Animal Fluency test, and Digit Symbol Substitution test. Multivariable logistic models and restricted cubic spline models were employed to investigate these associations. This study included a total of 2279 older adults in the United States. Only 11% of adults achieved a high total CVH score, while 12% had a low score. After further adjustment for potential confounding factors, higher LE8 scores were significantly associated with higher scores on CERAD: delayed recall score (0.02[0.01, 0.03]; P < 0.001), CERAD: total score (3 recall trials) (0.04[0.02, 0.06]; P < 0.001), animal fluency: total score (0.09[0.05, 0.12]; P < 0.001), and digit symbol: score (0.29[0.18, 0.41]; P < 0.001), demonstrating a linear dose-response relationship. Similar patterns were also observed in the associations between health behavior and health factor scores with cognitive function tests. LE8 scores exhibited positive linear associations with cognitive function. Maintaining better levels of CVH may be associated with higher levels of cognitive function in older Americans, but further research is needed to confirm the causal and temporal relationships between LE8 and cognitive function.

Association between cognitive insight and anxiety among community-dwelling schizophrenia patients: the chain mediating effects of family cohesion and chronotype

Objective

To investigate the effect of cognitive insight on anxiety in community-dwelling schizophrenia patients and to construct a chain mediating model to determine the underlying mechanisms of the relationship between cognitive insight and anxiety through family cohesion and chronotype.

Methods

The Beck Cognitive Insight Scale, the Chinese version of the Family Adaptability and Cohesion Scale, the Morningness-Eveningness Scale, and the Generalized Anxiety Disorder Scale were used to assess cognitive insight, family cohesion, chronotype, and anxiety in a sample of 785 individuals with schizophrenia living in the community. Spearman correlation analysis, multiple linear regression and Bootstrap methods were employed to analyze the four variables.

Results

Residential region, current employment status, and family economic status impacted anxiety among community-dwelling schizophrenia patients. All variables were associated with each other, but self-certainty was not significantly associated with anxiety. Cognitive insight and self-reflection had direct effects on anxiety, as well as indirect effects on anxiety through the partial mediating effect of chronotype, the suppressing effect of family cohesion, and the chain mediating effect of family cohesion and chronotype.

Conclusions

Family cohesion and chronotype can mediate the relationship between cognitive insight and anxiety. Improving family functioning, promoting emotional relationships within families, and correcting non-circadian sleep patterns can reduce anxiety in community-dwelling schizophrenia patients, with important implications for improving adverse mental health outcomes.

Association of sleep and generalized anxiety disorder in Korean adolescents

BACKGROUND

Generalized anxiety disorder (GAD) is a common anxiety disorder among adolescents, significantly impacting their concentration and learning capabilities. The connection between emotional well-being and sleep is well-established, and Korean adolescents are particularly prone to inadequate sleep. This study aimed to determine the association between sleep duration and GAD in Korean adolescents.

METHODS

This study was conducted using data from 106,513 adolescents aged 12-18 years. Data from the 2020-2022 Korea Youth Risk Behavior Survey were used. Sleep duration was classified into five groups, based on an average sleep duration of 7-7.9 h in adolescents. Social jet lag was defined as a misalignment between an individual's biological and social clocks. Differences in sleep duration between weekdays and weekends, social jet lag, and bedtime were each classified into three categories. Multiple logistic regression analysis was performed to evaluate the association between sleep duration and GAD.

RESULTS

Comparing the five groups classified based on sleep duration, adolescents in the groups that slept less experienced a significant increase in the odds of developing GAD (adjusted odds ratio [aOR]: boys: 1.10 in the 6.0-6.9-h group, 1.14 in the 5.0-5.9-h group, and 1.23 in the ≤ 4.9-h group; girls: 1.05 in the 6.0-6.9-h group, 1.19 in the 5.0-5.9-h group, 1.22 in the ≤ 4.9-h group). Adolescents with poor sleep quality experienced more frequent instances of inadequate sleep (aOR: boys: 2.51; girls: 2.43).

CONCLUSIONS

GAD is strongly associated with insufficient sleep. Consequently, it is imperative to assess and address GAD in adolescents with irregular sleep patterns.

Frontoparietal Response to Working Memory Load Mediates the Association between Sleep Duration and Cognitive Function in Children

Lack of sleep has been found to be associated with cognitive impairment in children, yet the neural mechanism underlying this relationship remains poorly understood. To address this issue, this study utilized the data from the Adolescent Brain Cognitive Development (ABCD) study (n = 4930, aged 9-10), involving their sleep assessments, cognitive measures, and functional magnetic resonance imaging (fMRI) during an emotional n-back task. Using partial correlations analysis, we found that the out-of-scanner cognitive performance was positively correlated with sleep duration. Additionally, the activation of regions of interest (ROIs) in frontal and parietal cortices for the 2-back versus 0-back contrast was positively correlated with both sleep duration and cognitive performance. Mediation analysis revealed that this activation significantly mediated the relationship between sleep duration and cognitive function at both individual ROI level and network level. After performing analyses separately for different sexes, it was revealed that the mediation effect of the task-related activation was present in girls (n = 2546). These findings suggest that short sleep duration may lead to deficit in cognitive function of children, particularly in girls, through the modulation of frontoparietal activation during working memory load.

Chronotype and emotion processing: a pilot study testing timing of online cognitive bias modification training

BACKGROUND

Circadian rhythms influence cognitive performance which peaks in the morning for early chronotypes and evening for late chronotypes. It is unknown whether cognitive interventions are susceptible to such synchrony effects and could be optimised at certain times-of-day.

OBJECTIVE

A pilot study testing whether the effectiveness of cognitive bias modification (CBM) for facial emotion processing was improved when delivered at a time-of-day that was synchronised to chronotype.

METHODS

173 healthy young adults (aged 18-25) with an early or late chronotype completed one online session of CBM training in either the morning (06:00 hours to 10:00 hours) or evening (18:00 hours to 22:00 hours).

FINDINGS

Moderate evidence that participants learnt better (higher post-training balance point) when they completed CBM training in the synchronous (evening for late chronotypes, morning for early chronotypes) compared with asynchronous (morning for late chronotypes, evening for early chronotypes) condition, controlling for pre-training balance point, sleep quality and negative affect. There was also a group×condition interaction where late chronotypes learnt faster and more effectively in synchronous versus asynchronous conditions.

CONCLUSIONS

Preliminary evidence that synchrony effects apply to this psychological intervention. Tailoring the delivery timing of CBM training to chronotype may optimise its effectiveness. This may be particularly important for late chronotypes who were less able to adapt to non-optimal times-of-day, possibly because they experience more social jetlag.

CLINICAL IMPLICATIONS

To consider delivery timing of CBM training when administering to early and late chronotypes. This may generalise to other psychological interventions and be relevant for online interventions where the timing can be flexible.

Validation of the French version of the Munich ChronoType questionnaire and associations between chronotype and physiological parameters

Assessing chronotype is essential in clinical and research environments, but the Munich ChronoType Questionnaire (MCTQ), a widely utilised tool, is not available in French. Therefore, we carried out an observational monocentric study to validate the French MCTQ against the sleep diary for sleep schedules, the Morningness-Eveningness Questionnaire (MEQ) for chronotype, and polysomnography measures. We utilised the mid-sleep point on free days (MSF), adjusted for sleep debt (MSFsc), to gauge morningness/eveningness. The study included 80 participants (average age: 40.9 years, 50% female). The sleep schedules determined by the MCTQ and the sleep diary showed a high correlation. The MSFsc demonstrated a significant correlation with the MEQ, persisting even under sleep constraints such as an alarm on free days. The predictive accuracy was strong for a morning chronotype and moderate for an evening chronotype as assessed using the MEQ. In summary, the French MCTQ is a reliable tool for researchers and clinicians for assessing sleep schedules and chronotype in French-speaking populations. The MSFsc can effectively predict chronotype, even under sleep constraints. However, for the evening chronotype, self-assessment appears to be more accurate. The association with polysomnography measures enriches our understanding of the chronotype at the intersection of behaviour and physiology.

Study on the circadian rhythm and sleep state characteristics of patients with acute cerebral infarction accompanied by sleep-breathing disorders

There is limited research on the circadian rhythm and sleep state in patients with acute cerebral infarction (ACI) accompanied by sleep-breathing disorders (SDB). This study aims to provide a scientific basis for individualized diagnosis and treatment for stroke-related SDB patients. The SC-500 sleep monitor was used to continuously monitor 1367 ACI patients over 5 days. Based on the apnea-hypopnea index (AHI), patients were divided into non-SDB group (normal) and SDB group (mild, moderate, severe, fluctuating). Interdaily stability (IS) and intradaily variability (IV) were calculated through heart rate monitoring, and sleep states and their correlations were analyzed. Compared to the non-SDB group, patients with moderate-to-severe ACI accompanied by SDB showed decreased IS, increased IV, and sleep fragmentation. Significant statistical differences were observed in total sleep time (TST), rapid eye movement latency (REML), sleep efficiency (SE), non-rapid eye movement stages 1-2 (NREM stages1-2), non-rapid eye movement stages 3-4 (NREM stages 3-4), proportion of non-rapid eye movement (NREM%), wake after sleep onset (WASO), and number of awakenings (NOA) between the SDB group and the non-SDB group (P < 0.05). AHI showed a strong negative correlation with IS and a strong positive correlation with IV. AHI was positively correlated with sleep latency (SL), REML, NREM stages1-2, NREM%, proportion of rapid eye movement (REM%), WASO, time out of bed (TOB), and NOA, and negatively correlated with TST, SE, NREM stages 3-4, and rapid eye movement (REM), all with statistical significance (P < 0.05). There were significant statistical differences in the Mini-Mental State Examination (MMSE) between patients with and without SDB, and among mild, moderate, severe, and fluctuating groups (P < 0.05). Patients with moderate-to-severe ACI accompanied by SDB are more likely to experience changes in circadian rhythm and sleep states, which in turn affect cognitive functions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-024-00516-1.

Prevalence, correlates, and mental health outcomes of social jetlag in Chinese school-age adolescents: A large-scale population-based study

BACKGROUND

This cross-sectional study aimed to examine the prevalence and correlates of social jetlag (SJL) in Chinese adolescents, as well as to test the relationships between SJL and mental health problems.

METHODS

A total of 106979 students (Mage = 13.0 ± 1.8 years; Nmale = 58296 [54.5 %]) from Shenzhen, China completed an online survey from May 24th to June 5th, 2022. Information on sociodemographics, lifestyles, sleep characteristics, anxiety symptoms, and depressive symptoms was collected by a self-administered questionnaire. Multivariate and binary logistic regression were adopted for data analysis.

RESULTS

17.8 % of participants experienced SJL ≥ 2 h. To adjust the accumulated sleep debt, sleep-corrected SJL (SJLsc) was calculated and 8.3 % of individuals self-reported SJLsc ≥ 2 h. Both SJL and SJLsc show an increasing trend with age. Risk factors of SJL included females, poor parental marital status, being overweight, physically inactive, smoking, drinking, and having a late chronotype. Moreover, males, having siblings, boarding at school, short sleep duration, experiencing insomnia, and frequent nightmares were significantly associated with an increased risk of SJLsc. After adjusting for all covariates, adolescents with SJLsc ≥ 2 h were more likely to have anxiety symptoms (OR: 1.35, 95 % CI: 1.24-1.48) and depressive symptoms (OR: 1.35, 95 % CI: 1.25-1.46) than those with SJLsc < 1 h.

CONCLUSIONS

SJL is common among Chinese school-age adolescents. This study is valuable for the development of prevention and intervention strategies for SJL in adolescents at the population level. Additionally, the strong links between SJLsc and emotional problems underscore the critical significance of addressing SJL as a key aspect of adolescent well-being.

Why circadian rhythmicity matters: Associations between sleep irregularity and mental health conditions during the Covid-19 health crisis

OBJECTIVE

To assess the association between sleep irregularity, anxiety, and depression while controlling for other sleep dimensions and using a longitudinal design.

METHODS

Longitudinal cohort study which started in April 2020 during the first French lockdown in the general population. Follow-up questionnaires were completed in June 2020, a period without lockdown measures. Participants were asked about their sleep (regularity, duration, timing, complaints) and their anxiety (General Anxiety Disorder-7) and depressive (Patient Health Questionnaire-9) symptoms.

RESULTS

A total of 3745 participants were included (mean age: 28.9 years) with 2945 women (78.6%). At baseline, 38.1% (1428) of participants reported irregular sleep timing, 23.8% (891) anxiety and 28.9% (1081) depressive symptoms. In cross-sectional analyses, irregular sleep timing was associated with a 2.5-fold higher likelihood of anxiety and a 4-fold higher likelihood of depressive symptoms compared to regular sleepers. Associations were not explained by the other sleep dimensions and persisted in a longitudinal analysis, with irregular sleep timing at baseline being associated with anxiety (OR = 3.27[1.58-6.76]) and depressive symptoms (OR = 3.45[1.66-7.19]) during follow-up.

CONCLUSION

The results show a strong association between sleep irregularity and mental health. Furthers studies are needed to explore how sleep regularity could promote good mental health in non-clinical populations.

Sleep quality mediates the association between chronotype and mental health in young Indian adults

There is increasing recognition of 'higher preference for eveningness' as a potential independent risk factor for poor mental health. To examine the chronotype-mental health relationship while also quantifying the potential roles of poor sleep quality, relevant personality traits, and childhood trauma, we assessed 282 young adults (18-40 years; 195 females) residing in North India, between January and March 2023 (to control for seasonal variation), using self-report measures of diurnal preference, sleep patterns, mental health (depression, anxiety, and stress), personality traits (extraversion, neuroticism, schizotypy, and impulsivity), and childhood trauma. The results showed a significant association between eveningness and poor mental health but this association was fully mediated by poor sleep quality. Neuroticism, emotional abuse and cognitive disorganisation were correlated with eveningness as well as with poor mental health and sleep quality. Neuroticism and emotional abuse, but not cognitive disorganisation, also had indirect effects on mental health via sleep quality. Our findings highlight the crucial role played by sleep quality in the chronotype-mental health relationship.

Association between dinner-bedtime interval and type 2 diabetes mellitus: a large-scale cross-sectional study

Objective

Glucose metabolism is impacted by circadian disruption. Dinner-bedtime interval (DBI) was an accessible indicator to reflect the alignment between dinner time and circadian clock. We aimed to investigate the association of DBI with type 2 diabetes mellitus (T2DM).

Methods

7676 adult subjects from the Henan Rural Cohort were included. Their demographic information including dinner time and bedtime was collected. Fasting venous blood samples were collected for biochemical determinations. Generalized linear regression model was used to analyze the factors influencing DBI. Furthermore, logistic regression incorporated with restricted cubic spline model was applied to evaluate the association between DBI and T2DM.

Results

The results of multiple linear regression model showed that age (β: -0.018, 95% CI: -0.021, -0.015) was negatively correlated with DBI. Female (β: 0.311, 95% CI: 0.229, 0.393), junior high school education (β: 0.246, 95% CI: 0.187, 0.306), high school education or above (β: 0.346, 95% CI: 0.259, 0.433), average monthly income with 1000-1999 CNY(0.102, 95% CI: 0.032, 0.171), average monthly income ≥ 2000 CNY (β: 0.164, 95% CI: 0.076, 0.251), moderate physical activity (β: 0.134, 95% CI: 0.071, 0.197), current smokers (β: 0.214, 95% CI: 0.118, 0.309), current drinkers (β: 0.099, 95% CI: 0.008, 0.190) were positively correlated with DBI. Furthermore, DBI was significantly associated with T2DM (adjusted OR: 0.910, 95%CI: 0.845-0.979, P = 0.012). DBI longer than 3 h was associated with decreased risk of T2DM (adjusted OR: 0.773, 95%CI: 0.648-0.921, P = 0.004).

Conclusions

DBI larger than 3 h is beneficial to T2DM prevention. Further investigation is required to verify the association.

Sleep patterns in Metropolitan and Regional areas in Japan: Before and during COVID-19 social restrictions

Sleep timing is an important output of the circadian system. The COVID-19-mandated social restrictions significantly altered commuting time and sleep duration regionally in Japan. This study aimed to elucidate sleep patterns, especially chronotype and social jetlag (SJL), due to changes in social time pressure through the social restrictions between the Metropolitan and Regional areas in Japan. As part of the Global Chrono Corona Survey 2020 (GCCS), the data were collected during social restrictions (SR), but pre-COVID-19 behaviours were also queried retrospectively. We analyzed a cohort of 729 respondents representing both the Metropolitan and the Regional areas separately for workdays and work-free days. While the areas showed no difference in SJL before SR, the differential decrease was larger in the Metropolitan area during SR, resulting in a significant difference in SJL between the areas. The outdoor light exposure before SR was 30 min longer in the Metropolitan areas than in the Regional; during SR both areas showed similarly low (below 1 h) outdoor light exposures. The variables associated with decreased SJL were the Metropolitan areas, work-from-home, a no-usage alarm clock on workdays, and chronotypes (mid-sleep time on free days corrected for sleep deficit accumulated over the workweek, MSFsc) during SR. The results suggest that relaxed social schedules, as reflected in the increased frequency of work-from-home and reduced alarm clock use, and moving towards earlier MSFsc during SR were linked to decreased SJL and were more prominent in the Metropolitan areas. This study provides insights into sleep patterns and the social time pressure markers, by comparison between residential groups in Japan.