Association between matched chronotype and poor mental health among shift workers: a systematic review and meta-analysis.

BACKGROUND: Nearly 0.7 billion workers are involved in the shift work system, leading to concerns about its potential impacts on the large-scale population mental health. This study aimed to synthesise evidence of the associations between matched chronotype and the risk of poor mental health among shift workers. METHODS: Six computerised databases were searched from inception to September 2022. Observational studies were selected if they reported any association between common mental health parameters and chronotype scores/types of shift workers. The Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist was followed. We extracted adjusted risk estimates to calculate pooled effect sizes and explore sources of heterogeneity. The study was registered in PROSPERO: CRD42022357437. RESULTS: Fourteen studies including 49 909 workers were identified. Ever shift workers had a higher risk of poor mental health than the day workers (pooled OR 1.15, 95% CI 1.03 to 1.28; I2=14%, p=0.29), with the evening chronotype ever shift workers having a 1.47 times higher risk than those who worked during the day (pooled OR 1.47, 95% CI 1.13 to 1.91; I2=42%, p=0.16). Sensitivity analysis excluding studies with the highest risk of bias of each group demonstrated consistent findings. CONCLUSIONS: Evening chronotype ever shift workers have poorer mental health than shift workers with other chronotypes. Chronotype remains unrecognised in the contemporary rostering system, making it a hidden contributor to occupational mental health. Work-related physical and mental stresses may be prevented/mitigated with further investigation on optimising shift work schedule combined with individual chronotype preference.

Competition for popularity and interventions on a Chinese microblogging site.

Microblogging sites are important vehicles for the users to obtain information and shape public opinion thus they are arenas of continuous competition for popularity. Most popular topics are usually indicated on ranking lists. In this study, we investigate the public attention dynamics through the Hot Search List (HSL) of the Chinese microblog Sina Weibo, where trending hashtags are ranked based on a multi-dimensional search volume index. We characterize the rank dynamics by the time spent by hashtags on the list, the time of the day they appear there, the rank diversity, and by the ranking trajectories. We show how the circadian rhythm affects the popularity of hashtags, and observe categories of their rank trajectories by a machine learning clustering algorithm. By analyzing patterns of ranking dynamics using various measures, we identify anomalies that are likely to result from the platform provider's intervention into the ranking, including the anchoring of hashtags to certain ranks on the HSL. We propose a simple model of ranking that explains the mechanism of this anchoring effect. We found an over-representation of hashtags related to international politics at 3 out of 4 anchoring ranks on the HSL, indicating possible manipulations of public opinion.

Impact of the COVID-19 pandemic on stress and sleep in emergency room professionals.

AIMS AND OBJECTIVES: To analyze stress levels, sleep quality, sleepiness and chronotypes on emergency room (ER) professionals before and during the COVID-19. BACKGROUND: ER healthcare professionals are exposed to high stress levels, and they often present with poor sleep quality. DESIGN: Observational study conducted into two different phases (before the COVID-19 and during the first wave of the COVID-19). METHOD: Physicians, nurses and nursing assistants working in the ER were included. Stress, sleep quality, daytime sleepiness and chronotypes were assessed by the Stress Factors and Manifestations Scale (SFMS), the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Horne and Österberg Morningness-Eveningness questionnaire, respectively. The first phase of the study was performed between December 2019 and February 2020, and the second between April and June 2020. The STROBE checklist was used to report the present study. RESULTS: In total, 189 ER professionals in the pre-COVID-19 phase and 171 (of the initial 189) during COVID-19 were included. The proportion of workers with a morning circadian rhythm increased during the COVID-19, and stress levels were significantly higher during COVID-19 compared to the previous phase (38.34 ± 10.74 vs. 49.97 ± 15.81). ER professionals with poor sleep quality presented higher stress in the pre-COVID-19 phase (40.60 ± 10.71 vs. 32.22 ± 8.19) and during COVID-19 (55.27 ± 15.75 vs. 39.66 ± 9.75). Similarly, workers with excessive sleepiness had higher stress in the pre-COVID-19 phase (42.06 ± 10.95 vs. 36.64 ± 10.24) and during COVID-19 (54.67 ± 18.10 vs. 48.44 ± 14.75). Positive associations were also found between the SFMS and the PSQI, as well as with the ESS in both phases of the study. CONCLUSIONS: Emergency room professionals had increased stress levels during the COVID-19 pandemic. Stress was particularly higher in those with poor sleep quality or with excessive daytime sleepiness. RELEVANCE TO CLINICAL PRACTICE: These results should aim to impulse the implementation of measures to improve the working conditions of ER professionals.

The impact of blue light and digital screens on the skin.

INTRODUCTION: The skin is frequently subjected to a variety of environmental trauma and stress. It is unavoidably subjected to blue light due to the increased use of electronic equipment, including indoor lighting and digital gadgets like smartphones and laptops, which have a range of detrimental effects. The method of action and numerous harmful consequences of blue light on the skin are the main subjects of this review. MATERIALS AND METHODS: A literature search has been performed using PubMed, GoogleScholar and EmBase databases and an updated review on the topic has been presented. RESULTS: Numerous studies have shown that being exposed to blue light accelerates the aging process and produces cutaneous hyperpigmentation. It also modifies the circadian rhythm. The two main molecules that mediate cellular responses to blue light are nitric oxide (NO) and reactive oxygen species. However, the precise process is still not fully known. CONCLUSION: These negative consequences may eventually cause more general skin damage, which may hasten the aging process. At times, skin protection may be crucial for protection against blue light.

Chronobiological changes due to school closures during the COVID-19 pandemic among adolescents in the DOrtmund Nutritional and Anthropometric Longitudinally Designed cohort study.

Due to the lockdown of schools as one of the COVID-19 control measures, adolescents have had the opportunity to re-organise their daily lives; e.g. some of them have adapted their bedtimes to the new situation during the lockdown in favour of their own chronotype. Hence, we investigated differences in chronobiological characteristics (e.g., the midpoint of sleep, sleep duration or social jetlag (SJL); i.e., a discrepancy between biological and social timing) before and during the pandemic lockdown to examine potential changes. We asked participants from the ongoing open cohort Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study to fill out the Munich Chronotype Questionnaire during the COVID-19 lockdown and received the information of participants (n = 66) during the pandemic. A reference group matched for age, season, and sex was randomly selected from the DONALD study to assess participants' chronobiological characteristics prior to (n = 132) the pandemic. Analyses of covariance were applied to examine differences between the two groups reflecting the situation before and during the COVID-19 pandemic. Participants were aged 9-18 years (52% males). In the current examination, average sleep duration across the week was higher among adolescents during the pandemic (ß = 00:30; p = 0.0006) and social jetlag was significantly lower (ß = -00:39; p < 0.0001). CONCLUSION: Our results showed that the COVID-19 lockdown enabled adolescents to adapt their sleeping habits according to their naturally late chronotype, which led to a significant reduction in SJL. These observations are likely to be explained by the effect of school closure. WHAT IS KNOWN: • Under 'normal conditions' without pandemic lockdowns, adolescents accumulate a lack of sleep due to social obligations such as school starts, resulting in social jetlag. • A late chronotype or exposure to social jetlag is a known risk factor for the development of chronic diseases. WHAT IS NEW: • The COVID-19 lockdown represents a 'natural experiment' that enables adolescents to adhere to their internal biological clock. Without the usual social obligations, social jetlag can be significantly reduced.

Circadian Timing, Information processing and Metabolism (TIME) study: protocol of a longitudinal study of sleep duration, circadian alignment and cardiometabolic health among overweight adults.

BACKGROUND: Both short sleep duration and circadian rhythm misalignment are risk factors for metabolic dysfunction, but the underlying mechanisms are unknown. The goal of this study is to examine how sleep duration and circadian alignment predict changes in cardiometabolic risk factors over a 12-month period, and test cognitive function and hedonic eating tendencies as potential mechanisms. METHODS: We will recruit a sample of 120 working aged adults with BMI 25-35 kg/m2 (overweight to class I obesity). The protocol includes 5 visits over a 12-month period. Study visits include wrist actigraphy to measure sleep behaviors, 24-h diet recalls, dim light melatonin collection, a computerized neurobehavioral assessment, eating in the absence of hunger task, and frequently sampled IV glucose tolerance test. DISCUSSION: The results of the TIME study will advance the understanding of how both short sleep duration and circadian misalignment contribute to behavioral aspects of obesity and metabolic dysfunction. TRIAL REGISTRATION: ClinicalTrials.Gov, NCT04759755 , registered retrospectively February 13, 2021.

Weight status of working adults: The effects of eating misalignment, chronotype, and eating jetlag during mandatory confinement.

This study aimed to examine the association between chronotype, eating jetlag, and eating misalignment with weight status among Malaysian adults during the COVID-19 restriction. This online cross-sectional study included 175 working adults recruited from March to July 2020. The chronotype was assessed using Morningness Eveningness Questionnaire (MEQ) while eating jetlag and mealtime variability were measured using Chrononutrition Profile Questionnaire (CPQ). Multiple linear regression demonstrated that lower breakfast frequency (ß = -0.258, p = .002) and longer eating duration (ß = 0.393, p < .001) were associated with later first eating events on workfree days. Both intermediate (ß = 0.543, p < .001) and evening chronotypes (ß = 0.523, p = .001) tend to eat their first meals later compared to morning person. Similar patterns were observed for overall eating jetlaggers in which lower breakfast frequency (ß = -0.022, p = .011), longer eating duration (ß = 0.293, p < .001), intermediate chronotype (ß = 0.512, p < .001), and evening chronotype (ß = 0.495, p = .003) were associated with eating later meals on workfree days. Additionally, higher BMI was also associated with eating later meals on workfree days (ß = 0.181, p = .025). During movement restriction, discrepancies of mealtimes during work and workfree days offer new insight into modern eating habits that can influence weight status and general eating habits such as breakfast skipping and total daily eating duration. Population meal timing variability was affected during movement restrictions, and it was closely related to weight status.

COVID-19 stay-at-home restrictions increase the alignment in sleep and light exposure between school days and weekends in university students.

Younger adults have a biological disposition to sleep and wake at later times that conflict with early morning obligations like work and school; this conflict leads to inadequate sleep duration and a difference in sleep timing between school days and weekends. The COVID-19 pandemic forced universities and workplaces to shut down in person attendance and implement remote learning and meetings that decreased/removed commute times and gave students more flexibility with their sleep timing. To determine the impact of remote learning on the daily sleep-wake cycle we conducted a natural experiment using wrist actimetry monitors to compare activity patterns and light exposure in three cohorts of students: pre-shutdown in-person learning (2019), during-shutdown remote learning (2020), and post-shutdown in-person learning (2021). Our results show that during-shutdown the difference between school day and weekend sleep onset, duration, and midsleep timing was diminished. For instance, midsleep during school days pre-shutdown occurred 50 min later on weekends (5:14 ±â€…12 min) than school days (4:24 ±â€…14 min) but it did not differ under COVID restrictions. Additionally, we found that while the interindividual variance in sleep parameters increased under COVID restrictions the intraindividual variance did not change, indicating that the schedule flexibility did not cause more irregular sleep patterns. In line with our sleep timing results, school day vs. weekend differences in the timing of light exposure present pre- and post-shutdown were absent under COVID restrictions. Our results provide further evidence that increased freedom in class scheduling allows university students to better and consistently align sleep behavior between school days and weekends.

Poor sleep quality during COVID-19 pandemic restrictions associated with reduced psychological wellbeing in healthcare students.

Sleep is inexorably linked to both physiological and psychological wellbeing. Restrictions imposed to control the COVID-19 pandemic likely impacted upon daily and weekly routines, which can have a negative impact on a range of factors including sleep quality, and/or quantity and general wellbeing. The aim of this study was to investigate the effect of COVID-19 related restrictions on sleep patterns and psychological wellbeing of healthcare students. A survey was delivered to healthcare students across three faculties at a single institution. Participants completed questionnaires on the effect of COVID-19 restrictions on course delivery and clinical placements, its effect on sleep-wake times, sleep quality, sleep hygiene, psychological wellbeing, their current sleep knowledge and sleep education in their current course. Using the Pittsburgh Sleep Quality Index (PSQI), over 75% of participants were found to have poor sleep quality. Changes in sleep habits and sleep behaviours during COVID-19 restrictions were associated with poorer sleep quality, and this poor sleep quality was associated with poor psychological wellbeing, particularly, motivation, stress and fatigue. Increases in negative sleep hygiene behaviours were associated with a statistically significant increase in PSQI global score. Positive emotions were positively correlated with PSQI (r = 0.22-0.24, p < .001), negative emotions were negatively correlated with PSQI (r = -0.22 - -0.31, p < .001). Also, a self-perceived lack of sleep education was identified. This study illustrates the negative association between self-reported poor sleep behaviour and poor sleep quality during COVID-19 restrictions on university student mental health and wellbeing. Additionally, there is a self-perceived lack of sleep education with little to no time spent educating students in their current degree. Hence, appropriate sleep education may improve sleep behaviours and subsequent sleep quality, which may prove to be a protective factor against poor mental health in the face of unexpected changes to routines.

Chronotype influence on the effects of COVID-19 lockdown on sleep and psychological status in France.

The present study aims to assess the influence of chronotype on lockdown-induced effects on sleep and psychological outcomes. A total of 1671 participants were recruited in France and filled out online questionnaires about their sleeping hours and sleep quality, their chronotype (morning, intermediate, evening type), and their depressive, anxiety and stress symptoms both retrospectively (before lockdown) and currently (during the lockdown). Statistical analyses estimated the chronotype effect on the impact of the lockdown on sleep and psychological outcomes. Results show that during the lockdown, sleep quality decreased, sleep duration increased, and sleep midpoint was delayed and, while fatigue perception decreased, anxiety and depression increased. The decrease in sleep quality varied according to the participants' chronotype. The evening type's sleep quality decreased the most. A similar chronotype effect was also observed on sleep duration and sleep midpoint. Evening-type participants also increased their depressive symptoms. These results suggest that evening-type individuals have lower resilience to lockdown effect on psychological status and sleep pattern.

The impact of circadian rhythm on Bacillus Calmette-Guérin vaccination effects on SARS-CoV-2 infections.

Background and objective: A recent study has suggested that circadian rhythm has an important impact on the immunological effects induced by Bacillus Calmette-Guérin (BCG) vaccination. The objective of this study was to evaluate whether the timing of BCG vaccination (morning or afternoon) affects its impact on severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infections and clinically relevant respiratory tract infections (RTIs). Methods: This is a post-hoc analysis of the BCG-CORONA-ELDERLY (NCT04417335) multicenter, placebo-controlled trial, in which participants aged 60 years and older were randomly assigned to vaccination with BCG or placebo, and followed for 12 months. The primary endpoint was the cumulative incidence of SARS-CoV-2 infection. To assess the impact of circadian rhythm on the BCG effects, participants were divided into four groups: vaccinated with either BCG or placebo in the morning (between 9:00h and 11:30h) or in the afternoon (between 14:30h and 18:00h). Results: The subdistribution hazard ratio of SARS-CoV-2 infection in the first six months after vaccination was 2.394 (95% confidence interval [CI], 0.856-6.696) for the morning BCG group and 0.284 (95% CI, 0.055-1.480) for the afternoon BCG group. When comparing those two groups, the interaction hazard ratio was 8.966 (95% CI, 1.366-58.836). In the period from six months until 12 months after vaccination cumulative incidences of SARS-CoV-2 infection were comparable, as well as cumulative incidences of clinically relevant RTI in both periods. Conclusion: Vaccination with BCG in the afternoon offered better protection against SARS-CoV-2 infections than BCG vaccination in the morning in the first six months after vaccination.

Effects of Physical Activity and Circadian Rhythm Differences on the Mental Health of College Students in Schools Closed by COVID-19.

Purpose: Since the prolonged sequestration management that was implemented in order to achieve lower infection and mortality rates, there has been a surge in depression worldwide. The correlation between the physical activity level and the detection rate of a depressed mood in college students should be of wide concern. A large number of studies have focused on the association between physical activity levels and a negative mood, but circadian rhythm differences seem to be strongly associated with both physical activity levels and mental illness. Therefore, this paper will examine the correlation between physical activity levels, circadian rhythm differences, and mental health levels in college students. METHODS: Data were collected through a web-based cross-sectional survey. In June and December 2022, questionnaires were administered to college students from three universities in Anhui, China. In addition to socio-demographic information, measures included the International Physical Activity Questionnaire-Short Form (IPAQ-SF), Morning and Evening Questionnaire-5 Items (MEQ-5), and Symptom Check List90 (SCL-90) scales. Correlation analysis was used to understand the relationship between physical activity and circadian rhythm differences in the three aspects of college student's mental health. RESULTS: The analysis of the data led to the conclusion that 28.4% of the 1241 college students in this survey had psychological disorders. The physical activity level of male students was higher than that of female students, but the risk of having depressive tendencies was higher in female students than in male students. There was a significant negative correlation between the physical activity level and scl-90 scores (p < 0.01), which indicates that higher physical activity levels are associated with higher mental health. Circadian rhythm differences and scl-90 scores were significantly positively correlated among college students (p < 0.01), and night-type people had a higher risk of mental illness than intermediate-type and early-morning-type people. CONCLUSIONS: During the period of closed administration due to COVID-19, school college students experienced large and high levels of negative emotional phenomena due to reduced physical activity and public health emergencies. This study showed significant correlations between both physical activity levels and circadian rhythmicity differences and the degree of mental health of college students.

Regular, intermittent, and spontaneous: Patterns of preschool Children's nap behavior and their correlates.

BACKGROUND: Daytime sleep during the preschool years (i.e., 1-5-years-old) is characterized by high inter-child variability in several components of nap behavior, including nap duration, nap timing, and the proportion of sleep during daytime. We used an empirical approach to examine variations amongst children in these aspects of napping and investigated correlates of these components of nap behavior. METHODS: A large, nationally representative sample (N = 702) of Canadian parents completed an online survey, including a one-month retrospective report of their 1.5-5 year old's daytime and nighttime sleep behavior and other questionnaires. To understand patterns of children's nap behaviors we applied Latent Profile Analysis (LPA) to typical nap duration, typical timing of naps, frequency of naps, proportion of sleep during the daytime, and the proportion of naps which were spontaneous (i.e., child just fell asleep). Then, multinominal logistic regression was used to examine correlates of profile membership. RESULTS: Four profiles of children emerged: (1) regular nappers; (2) intermittent nappers; (3) spontaneous nappers; and (4) non-nappers. After controlling for demographic variables (e.g., child age, sex, ethnicity) and known correlates of napping behaviors (e.g., birthweight, nighttime sleep duration), profile membership was related to parents' beliefs about napping, parents' own nap behaviors, family functioning, and child nighttime sleep problems in a multinominal logistic regression. CONCLUSIONS: An empirical approach aided in understanding the inter-child variability in napping amongst preschool-age children. Parental beliefs about napping and the home environment were shown to be critical factors influencing this variability.

Effect of lockdown on sleep-wake rhythm and alcohol use.

The global covid-19 pandemic has imposed radical changes in daily lives. This study reflects upon sociodemographic and clinical characteristics (sleep-wake rhythm, psychiatric symptoms, and alcohol use behavior) during the full lockdown, comparing individuals who increased their alcohol use (iAU), those who maintained a stable use (sAU), and those who did not consume alcohol (AnoU). Participants were recruited via e-mails and they were required to complete an online survey that included questionnaires, during the last week of the full lockdown. The iAU group, compared to the sAU group, presented more disturbed sleep (PSQI; p < .001), more severe insomnia (ISI; p < .001), shorter sleep duration (p < .001), longer sleep latency (p < .001), and less regular sleep-wake schedules (p = .005). They also reported more anxiety (HAD-A; p = .009), more depressive symptoms (HAD-D: p = .006) and more psychotraumatic symptoms (PCL-5: p = .018). Moreover, the sAU group, compared to AnoU, showed better quality of sleep (PSQI; p = .002) and less severe anxiety symptoms (HAD-A; p = .014). Maintaining a stable use was also related to a better quality of life associated with bigger homes with more frequent outdoors living spaces and higher monthly incomes. Individuals who increased their alcohol consumption during the Covid-19 lockdown exhibited more sleep and circadian rhythm disturbances, as well as more (severe) psychiatric symptoms.

Monkeypox virus replication underlying circadian rhythm networks.

The mammalian brain has an endogenous central circadian clock that regulates central and peripheral cellular activities. At the molecular level, this day-night cycle induces the expression of upstream and downstream transcription factors that influence the immune system and the severity of viral infections over time. In addition, there are also circadian effects on host tolerance pathways. This stimulates adaptation to normal changes in environmental conditions and requirements (including light and food). These rhythms influence the pharmacokinetics and efficacy of therapeutic drugs and vaccines. The importance of circadian systems in regulating viral infections and the host response to viruses is currently of great importance for clinical management. With the knowledge gained from the COVID-19 pandemic, it is important to address any outbreak of viral infection that could become endemic and to quickly focus research on any knowledge gaps. For example, responses to booster vaccination COVID-19 may have different time-dependent patterns during circadian cycles. There may be a link between reactivation of latently infected viruses and regulation of circadian rhythms. In addition, mammals may show different seasonal antiviral responses in winter and summer. This article discusses the importance of the host circadian clock during monkeypox infection and immune system interactions.

Influence of electromagnetic fields on the circadian rhythm: Implications for human health and disease.

Living organisms have evolved within the natural electromagnetic fields (EMFs) of the earth which comprise the global atmospheric electrical circuit, Schumann resonances (SRs) and the geomagnetic field. Research suggests that the circadian rhythm, which controls several physiological functions in the human body, can be influenced by light but also by the earth's EMFs. Cyclic solar disturbances, including sunspots and seasonal weakening of the geomagnetic field, can affect human health, possibly by disrupting the circadian rhythm and downstream physiological functions. Severe disruption of the circadian rhythm increases inflammation which can induce fatigue, fever and flu-like symptoms in a fraction of the population and worsen existing symptoms in old and diseased individuals, leading to periodic spikes of infectious and chronic diseases. Possible mechanisms underlying sensing of the earth's EMFs involve entrainment via electrons and electromagnetic waves, light-dependent radical pair formation in retina cryptochromes, and paramagnetic magnetite nanoparticles. Factors such as electromagnetic pollution from wireless devices, base antennas and low orbit internet satellites, shielding by non-conductive materials used in shoes and buildings, and local geomagnetic anomalies may also affect sensing of the earth's EMFs by the human body and contribute to circadian rhythm disruption and disease development.

The association of chronotype and social jet lag with body composition in German students: The role of physical activity behaviour and the impact of the pandemic lockdown.

Young adults with a later chronotype are vulnerable for a discrepancy in sleep rhythm between work- and free days, called social jet lag (SJL). This study analysed (i) chronotype/SJL association with visceral fat/skeletal muscle mass, (ii) the attribution to physical activity behaviour, and (iii) chronotype-specific changes in physical activity behaviour in young adults during the Covid-19 pandemic lockdown. Chronotype and SJL were derived from the Munich-Chrono-Type-Questionnaire in 320 German students (age 18-25 years) from September 2019 to January 2020, 156 of these participated in an online follow-up survey in June 2020. Body composition was assessed by bioimpedance analysis at baseline. Multivariable linear regression analyses were used to relate chronotype/SJL to body composition; the contribution of self-reported physical activity was tested by mediation analysis. At baseline, a later chronotype and a larger SJL were associated with a higher visceral fat mass (P<0.05), this relation was notably mediated by the attention to physical activity (P<0.05). Chronotype (P = 0.02) but not SJL (P = 0.87) was inversely associated with skeletal muscle mass. During the pandemic lockdown, chronotype hardly changed, but SJL was reduced. Timing and physical activity behaviour remained in most participants and changes were unrelated to chronotype (all P>0.07). A later chronotype/higher SJL may increase the risk of a higher visceral fat mass even in this relatively healthy sample, which may be partly due to their physical activity behaviour. Despite a reduction in SJL during the pandemic lockdown, later chronotypes did not change their physical activity behaviour more than earlier chronotypes.

Deconstructing the functional neuroanatomy of the choroid plexus: an ontogenetic perspective for studying neurodevelopmental and neuropsychiatric disorders.

The choroid plexus (CP) is a delicate and highly vascularized structure in the brain comprised of a dense network of fenestrated capillary loops that help in the synthesis, secretion and circulation of cerebrospinal fluid (CSF). This unique neuroanatomical structure is comprised of arachnoid villi stemming from frond-like surface projections-that protrude into the lumen of the four cerebral ventricles-providing a key source of nutrients to the brain parenchyma in addition to serving as a 'sink' for central nervous system metabolic waste. In fact, the functions of the CP are often described as being analogous to those of the liver and kidney. Beyond forming a barrier/interface between the blood and CSF compartments, the CP has been identified as a modulator of leukocyte trafficking, inflammation, cognition, circadian rhythm and the gut brain-axis. In recent years, advances in molecular biology techniques and neuroimaging along with the use of sophisticated animal models have played an integral role in shaping our understanding of how the CP-CSF system changes in relation to the maturation of neural circuits during critical periods of brain development. In this article we provide an ontogenetic perspective of the CP and review the experimental evidence implicating this structure in the pathophysiology of neurodevelopmental and neuropsychiatric disorders.

AMBULATORY BLOOD PRESSURE VARIABILITY IN YOUNG ADULTS WITH LONG-COVID SYNDROME.

OBJECTIVE: The aim: To perform an overall assessment of BP and BP variability using ambulatory measurements in young adults with long COVID syndrome. PATIENTS AND METHODS: Materials and methods: We enrolled young patients with diagnosed long-COVID syndrome (n = 58, mean age 23.07 ± 1.54 years), compared with an age-matched healthy subjects who had not suffered from COVID-19 (n = 57, mean age 22.9 ± 1.83 years). Patients with long-COVID syndrome had recovered from mild/moderate illness and none had required hospitalization. Ambulatory 24 hours blood pressure (AMBP) parameters (mean BP, daytime BP, nighttime BP, pulse pressure, nocturnal systolic BP dipping, dipper status) were measured in all participants. The variability of systolic BP (SBP) and diastolic BP (DBP) values was assessed by the following common metrics, including the average real variability (ARV), the coefficient of variation (CV), the standard deviation (SD), and the weighed SD of SBP and DBP. RESULTS: Results: The average values of 24-hour ambulatory blood pressure, mean BP, daytime and nighttime systolic BP, diastolic BP and pulse pressure were found to be significantly different among patients with long COVID syndrome and control group. Group analyses showed that this difference was in SBP mean values (127.1 ± 6.65 mmHg and 115.93 ± 6.24 mmHg respectively) and DBP mean values (73.31 ± 5.30 mmHg and 68.79 ± 5.5 mmHg respectively) mainly at night. PP values at daytime were almost similar among groups, but PP values at nighttime were higher in patients with long-COVID syndrome (53.8 (52.44- 55.14) mmHg and 47.14 (46.45 - 47.88) mmHg respectively). Nocturnal SBP dipping was better in control group than in patients with long-COVID syndrome ( 5.3 ± 5.68 and 3.1 ± 3.79 mmHg respectively). Only 13 (22.4%) patients with long-COVID syndrome had normal dip-per status while more than half - 38 (66.7%) in healthy subjects. The values of ARV of SBP and DBP over 24-hour, awake, and asleep time frames were found to be greater in patients with long COVID syndrome than healthy controls (p < 0.05). CONCLUSION: Conclusions: Patients with long- COVID syndrome have higher BP mean values of 24-hour ABPM particularly at nightime, significant blood pressure BP variability, which increases the risk of cardiovascular events in future. Nevertheless, the further prospective investigations is warranted to investigate the potential mechanisms and causality associations.