Development of the circadian system in early life: maternal and environmental factors

The Effect of a Chronobiological Feeding Model on Growth Parameters and Length of Hospitalization in Preterm Infants: A Randomized Controlled Study

Background and Purpose: Preterm infants are born before the 37th gestational week and need prompt nutrition. The circadian rhythm is an internal 24-hour cycle regulated by endogenous molecules. Human milk contains different biological peptides at different times within this cycle. Chrononutrition is a feeding model that is adjusted to match the biological clock of the individual. This study tests chrononutrition as a superior feeding model in preterm infants. This study aimed to evaluate the effect of the chronobiological feeding model on growth parameters and discharge time among preterm infants. Methods: We conducted a prospective, randomized controlled trial in a tertiary neonatal intensive care unit between October 2021 and March 2022, randomized preterm infants to receive either chrononutrition (study group = 45) or standard feeding (control group = 46), and used the infant's follow-up form for data collection. Results: Among 91 neonates, the median gestational age was 33 weeks, and the mean birth weight was 2,100 g. Demographic findings and growth parameters showed no difference between the groups (p > 0.05). Weight gain and percentile measurements at discharge were statistically significantly higher in the study group (p = 0.002 and p = 0.003, respectively). Discharge time was statistically significantly lower after full enteral feeding and hospitalization time was shorter in the study group (p = 0.001). Conclusions: The chronobiological feeding model showcased significant positive effects on anthropometrics and percentile measurements at discharge and led to a 2-day reduction in the length of hospital stay.

An integrated approach to understanding the effects of exposome on neuroplasticity

Anthropogenic factors are those that occur due to human activities. The exposome is proposed to complement the genome, wherein an individual's exposure begins before birth. The range of exposures includes physical, chemical, dietary, lifestyle, biological, and occupational sources. Exposome has a positive or negative influence on neuroplasticity during different stages of life. A comprehensive study of the exposome is thus necessary to incorporate these factors and their influence on the individual, community, and the population as a whole. Exposomic research and global health present significant opportunities for interdisciplinary research. This review gives an overview of the exposome and its influence on neuroplasticity. It proposes methods to study the exposome on neuroplasticity across the lifespan of the individual. This is possible with the use of self-reported data, large-scale cohort formation, physiological sensors, neuroimaging, omics, molecular biology, and systems approaches. These approaches aim to provide a holistic understanding of an individual's neurological well-being and its implications for the population at large. This will also enable the designing of novel preventive and treatment strategies for managing neurological disorders.

Circadian rhythm defects in Prader-Willi syndrome neurons

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by a spectrum of symptoms, including developmental delay, intellectual disability, and increased risk of autism. PWS is an imprinting disorder caused by the loss of paternal expression of critical genes in the 15q11.2-q13 region, including MAGEL2, SNRPN/SNURF, and SNORD116. PWS patients often suffer from various sleep disorders, including sleep-disordered breathing and central hypersomnolence. Mouse models of PWS also exhibit disruptions in circadian rhythms and sleep. In cultured cells, Magel2 was shown to regulate the expression of Bmal1 and Per2, two core clock genes involved in the circadian rhythm regulatory process. Here, we investigated the circadian clock function in neurons derived from dental pulp stem cells (DPSCs) of PWS patients and neurotypical controls. To study the circadian rhythms of PWS patients in vitro, we introduced the Per2 promoter-driven luciferase reporter (Per2:luc) to these DPSC cell lines to assess their circadian rhythm by bioluminescence. These Per2:luc cells were differentiated for 4 weeks to mature neuronal reporter cell lines, followed by kinetic measurements of luciferase activity over several days. We observed significant differences in circadian period length between PWS neurons and controls. Moreover, treatment with the small molecule longdaysin effectively lengthened the period length of PWS neurons with a shorter period length, as anticipated based on the mechanism of action of this compound. This work lays the foundation for a deeper understanding of PWS pathophysiology and represents a critical first step toward developing high-throughput assays for drug discovery targeting circadian and sleep dysfunction in PWS.

Circadian control in the timing of critical periods during Drosophila larval neuronal development

Developing neural circuits are maximally open to modification during defined critical periods (CPs).1,2,3,4 We previously identified a CP in the Drosophila embryo, from 17 to 19 h after egg laying (AEL), during which activity manipulation (optogenetic and/or pharmacological) permanently alters locomotor network stability.5,6 Analysis of excitatory and inhibitory inputs to an identified motoneuron shows that CP activity manipulation preferentially enhances excitation.7 This effect is permanent, persisting through to third instars (5 days post manipulation). A manifestation of this effect is a marked increase in seizure recovery time (RT) in response to an electric shock. The induced seizure results in immediate paralysis, followed by uncoordinated peristalsis until the larva recovers sufficiently to move away from its original position (i.e., the seizure endpoint).6 Significantly, exposure to blue light (BL) during this same embryonic temporal window is similarly able to lead to an increased seizure RT, an effect that requires the presence of CRYPTOCHROME (CRY).8 Here, we identify a series of BL-sensitive CPs, occurring at ∼24-h intervals, from embryogenesis through larval development. Exposure to BL during these CPs increases the time taken for wandering larvae to recover from electroshock-induced seizure activity. This effect is absent when CRY or the principal clock-signaling neuropeptide-pigment-dispersing factor (PDF)-is absent. Thus, we uncover a novel role for the circadian clock during the embryonic and larval stages of Drosophila neural development.

Melatonin use in typically developing (TD) children: International Pediatric Sleep Association (IPSA) Expert Consensus Recommendations for Healthcare Providers

Although melatonin is widely used globally for the management of insomnia in children and adolescents, there are few clinical guidelines available for healthcare practitioners, particularly in typically developing (TD) children. Because existing data are either sparse or inconclusive, a task force comprised of pediatric sleep researchers and clinicians was established by the International Pediatric Sleep Association (IPSA) to first examine the available literature and to then develop a set of evidence-based (when possible) and consensus-based recommendations to guide practitioners in decision-making regarding melatonin use in pediatric insomnia. The following recommendations regarding appropriate indications for melatonin in children, considerations regarding timing and dosage, safety issues and caveats in recommending use of melatonin in pediatric clinical settings, are presented as a companion to a Technical Report summarizing the available literature.

Sleep Duration, Sleep Habits, and Social Jetlag From 4 to 6 years Their Impacts on Myopia Among School-Aged Children: The Ma'anshan Birth Cohort Study

Purpose

To examine the associations of sleep parameters and their trajectories at preschool age with myopia among school-aged children by using a birth cohort study design.

Patients and methods

All participants were recruited from the Ma'anshan Birth Cohort Study. Sleep duration, sleep habits, and social jetlag were collected in 4 years, 5.5 years, and 6 years. Cycloplegic refraction and ocular biometry were performed at 7 years. Key statistical analyses were performed using the latent class growth models, binary logistic regression, generalized linear models, and linear mixed models, respectively.

Results

A total of 1561 children were included in the study (mean age of 7.93 years, 52.6% boys). Social jetlag of at least 1 hour at age 4 was positively linked to an increased risk of myopia in school-age children and axial length (AL) but negatively correlated with spherical equivalent refraction (SER) (P<0.05). Inadequate sleep duration at 5.5 years was associated with an increase in AL among school-age children (β=0.16; 95% CI: 0.07-0.24). A pattern of increasing-declining social jetlag was positively correlated with AL/CR ratio (RR=1.55; 95%CI: 1.01-2.37). Poor sleep habits, higher social jetlag at age 4, and the declining-increasing trajectory of social jetlag were negatively associated with SER in school-aged children (P<0.05). Furthermore, the declining-increasing and increasing-declining trajectories of social jetlag were positively correlated with the elongation of AL.

Conclusion

The correlations between sleep parameters at preschool age and myopia in school-aged children reveal that maintaining regular sleep habits in preschool may contribute to the early prevention of myopia.

Altered sleep and inflammation are related to outcomes in neonatal encephalopathy

AIM

Immune dysregulation and delayed onset of sleep wake cycling (SWC) are associated with worse outcome in neonatal encephalopathy (NE), however the association between sleep and immune dysfunction in NE remains unclear. Aimed to evaluate association of sleep and systemic inflammation with outcomes in NE.

METHODS

Amplitude-integrated electroencephalography (aEEG) recordings were collected on infants undergoing therapeutic hypothermia (TH). Duration to onset of (SWC) and sleep quality (SQ) were examined. Blood samples collected during the first 2 days of life. Thirteen pro- and anti-inflammatory serum cytokines were quantified. Adverse outcome defined as death or abnormal MRI brain.

RESULTS

Earlier onset of SWC and better SQ had less adverse outcomes. SQ provided better prognostic value and showed better interobserver agreement compared to duration to SWC. Better SQ associated with lower cytokines EPO and interleukin (IL)-1β. In infants with unfavourable outcome, shorter duration to SWC was associated with higher EPO and better SQ was associated with lower TNF-α.

CONCLUSION

Earlier onset of SWC or better SQ showed less systemic inflammation and fewer adverse outcomes. SQ during TH provided better prognostic information than time of onset of SWC. Modulation of circadian rhythm in infants with NE may have an immunomodulatory role, leading to improved outcomes.

Sleep profile in patients with septo-optic-pituitary dysplasia: protocol for a prospective cohort study

INTRODUCTION

Children with septo-optic-pituitary dysplasia (SOD) may experience a range of visual impairments and hormonal dysfunctions beyond developmental delay/intellectual disability. The literature describes sleep fragmentation, circadian rhythm disruptions and reduced sleep efficiency. These manifestations are believed to be closely linked to both structural and functional abnormalities associated with SOD, potentially disrupting the natural circadian rhythm. Both anomalies in midline brain structures and decreased visual input could potentially impact melatonin secretion, although a distinct melatonin profile for SOD patients has yet to be identified. Furthermore, the specific contribution of these factors to sleep disturbances in SOD remains unexplored. The aim of this study is to evaluate the quality of sleep and its characteristics, along with the melatonin profile, among paediatric patients diagnosed with SOD. A comparison will be made between these findings and those of children with isolated bilateral visual impairment, as well as patients with agenesis of the corpus callosum.

METHODS AND ANALYSIS

Participants aged between 3 and 18 years previously diagnosed with SOD will be recruited prospectively. Each participant will be assessed at baseline and at each follow-up visit scheduled to evaluate the clinical course. Sleep quality and daytime sleepiness changes will be tracked using actigraphic assessment, standardised sleep questionnaires and a sleep EEG. Additionally, plasma and salivary melatonin profiles will be assessed for each participant.

ETHICS AND DISSEMINATION

This study has been approved by local Ethics Committee (N°0049187/23). The study findings will be shared through publication in an international peer-reviewed journal and presented at both national and international conferences.

TRIAL REGISTRATION NUMBER

NCT06262152.

The development of preterm infants from low socio-economic status families: The combined effects of melatonin, autonomic nervous system maturation and psychosocial factors (ProMote): A study protocol

Preterm births constitute a major public health issue and a chronic, cross-generational condition globally. Psychological and biological factors interact in a way that women from low socio-economic status (SES) are disproportionally affected by preterm delivery and at increased risk for the development of perinatal mental health problems. Low SES constitutes one of the most evident contributors to poor neurodevelopment of preterm infants. Maternal perinatal mental health disorders have persistent effects on behavioral and physiological functioning throughout the lifespan and may even be evident across generations. The overall objective of the proposed longitudinal, multi-disciplinary and multi-method study is to compare the association of psychosocial (maternal mental health, intersubjectivity, attachment, family functioning, dyadic coping and perceived social support), and biological factors (melatonin and heart rate variability) with preterm infants' development at 9 months (corrected age), between low and high SES families. We will collect data from preterm neonates (<37 weeks gestational age) hospitalized in the Department of Neonatology/Neonatal Intensive Care Unit of the University General Hospital of Heraklion, Greece, and their mothers. Data collection of psychosocial and biological factors will be carried out at birth, and at the corrected age of 6 and 9 months, while preterm infants' cognitive and social development will be assessed at 9 months corrected age. The findings of this study may highlight the need for early interventions for new mothers coming from low SES in order to promote their preterm infants' optimal early neurodevelopment and for community-evidence-based prevention efforts to restrict the cycle of health inequities and intergenerational mental disorders.

The role of light exposure in infant circadian rhythm establishment: A scoping review perspective

Environmental light exposure plays a role in the entrainment of the infant circadian rhythm, which is crucial for growth and development. This scoping review aims to evaluate existing literature linking the role of light exposure in the development of the infant circadian rhythm. This scoping review is conducted in accordance with the PRISMA-ScR guidelines. The search strategy was conducted in a total of six databases (PubMed, Cochrane Database of Systematic Reviews, Science Direct, Google Scholar, Taylor and Francis, and Wiley) as of August 2024. Reviews, narrative studies, observational studies, and experimental studies published from 2012 to 2024 were extracted. These studies discussed the role of light exposure on the development of infant circadian rhythm. A total of 25 studies were retrieved (3 observational studies, 6 experimental studies, and 16 reviews). Evidence showed that cycled lighting is beneficial for the entrainment of the infant circadian rhythm according to the 24-h light-dark cycle. Cycled lighting improved nighttime sleep and daytime wakefulness, promoting optimum growth and development. Limited experimental studies were conducted due to the ethical considerations of infants as study participants. Conclusions: Given the benefits of cycled lighting in the development of the circadian rhythm development, it should be implemented in both healthcare and home settings to promote optimum growth and development of the infant.

Exercise improves muscle mitochondrial dysfunction-associated lipid profile under circadian rhythm disturbance

We investigated whether endurance exercise training (EXT) ameliorates circadian rhythm (CR)-induced risk factors by improving skeletal muscle (SKM) mitochondrial biogenesis, reducing oxidative stress, and modulating apoptotic protein expression. We distinguished between regular and shift workers using the National Health and Nutrition Examination Survey (NHANES) and investigated the health problems caused by shift work (CR disturbance) and the potential therapeutic effects of exercise. In our animal study, 36 rats underwent 12 weeks of CR disturbance, divided into regular and irregular CR groups. These groups were further split into EXT (n = 12) and sedentary (n = 12) for an additional 8 weeks. We analyzed SKM tissue to understand the molecular changes induced by CR and EXT. NHANES data were analyzed using SAS 9.4 and Prism 8 software, while experimental animal data were analyzed using Prism 8 software. The statistical procedures used in each experiment are indicated in the figure legends. Our studies showed that CR disturbance increases dyslipidemia, alters circadian clock proteins (BMAL1, PER2), raises apoptotic protein levels, and reduces mitochondrial biogenesis in SKM. EXT improved LDL-C and HDLC levels without affecting muscle BMAL1 expression. It also enhanced mitochondrial biogenesis (AMPK, PGC-1α, Tfam, NADH-UO, COX-I), antioxidant levels (Catalase, SOD1, SOD2), and apoptotic protein (p53, Bax/Bcl2) expression or activity in SKM. We demonstrated that shift work-induced CR disturbance leads to dyslipidemia, diminished mitochondrial biogenesis, and reduced antioxidant capacity in SKM. However, EXT can counteract dyslipidemia under CR disturbance, potentially lowering the risk of cardiovascular disorders.

Mapping the physiological changes in sleep regulation across infancy and young childhood

Sleep patterns in infancy and early childhood vary greatly and change rapidly during development. In adults, sleep patterns are regulated by interactions between neuronal populations in the brainstem and hypothalamus, driven by the circadian and sleep homeostatic processes. However, the neurophysiological mechanisms underlying the sleep patterns and their variations across infancy and early childhood are poorly understood. We investigated whether a well-established mathematical model for sleep regulation in adults can model infant sleep characteristics and explain the physiological basis for developmental changes. By fitting longitudinal sleep data spanning 2 to 540 days after birth, we inferred parameter trajectories across age. We found that the developmental changes in sleep patterns are consistent with a faster accumulation and faster clearance of sleep homeostatic pressure in infancy and a weaker circadian rhythm in early infancy. We also find greater sensitivity to phase-delaying effects of light in infancy and early childhood. These findings reveal fundamental mechanisms that regulate sleep in infancy and early childhood. Given the critical role of sleep in healthy neurodevelopment, this framework could be used to pinpoint pathophysiological mechanisms and identify ways to improve sleep quality in early life.

Postnatal Development of the Circadian Rhythmicity of Human Pineal Melatonin Synthesis and Secretion (Systematic Review)

Introduction: According to current knowledge, at birth, the pineal gland and melatonin receptors are already present and the suprachiasmatic nucleus is largely functional, and noradrenaline, the key pineal transmitter, can be detected in the early foetal period. It is still unclear why the pineal gland is not able to start its own pulsatile synthesis and secretion of melatonin in the first months of life, and as a result, infants during this time are dependent on an external supply of melatonin. Method: The causes and consequences of this physiological melatonin deficiency in human infancy are examined in a systematic review of the literature, in which 40 of 115 initially selected publications were evaluated in detail. The references of these studies were checked for relevant studies on this topic. References from previous reviews by the author were taken into account. Results: The development and differentiation of the pineal gland, the pinealocytes, as the site of melatonin synthesis, and the development and synaptic coupling of the associated predominantly noradrenergic neural pathways and vessels and the associated Lhx4 homebox only occurs during the first year of life. Discussion: The resulting physiological melatonin deficiency is associated with sleep disorders, infant colic, and increased crying in babies. Intervention studies indicate that this deficiency should be compensated for through breastfeeding, the administration of nonpooled donor milk, or through industrially produced chrononutrition made from nonpooled cow's milk with melatonin-poor day milk and melatonin-rich night milk.

Biological clock and circadian rhythm of breast milk composition

Breast milk provides numerous benefits for both the baby and the mother, making it a unique and valuable food. The World Health Organization and the United Nations International Children's Emergency Found (UNICEF) state that exclusive breastfeeding in the first six months of life is an important strategy for reducing mortality and morbidity in infants. The circadian rhythm formation, which starts in the mother's womb, continues after the baby is born. Breast milk plays an active role in regulating the baby's circadian rhythm through the hormones, basic immune factors and bioactive components it contains, as well as meeting almost all nutritional elements for babies. Since the neural control mechanisms in the newborn are not yet fully developed, breast milk undertakes the task of helping the biological rhythms in the regulation of the infant's sleep-wake cycles, thanks to the circadian rhythm of some elements in its composition. There are studies showing that breast milk contains high levels of cortisol and amino acids that promote activity during the day, while night milk has high levels of melatonin and tryptophan, and micronutrients vary throughout the day. A better understanding of the circadian rhythm displayed by the elements in the composition of breast milk is important for improving maternal and infant health. Since there are many factors affecting the composition of breast milk, it is recommended that breast milk studies should be done on a country or regional basis, and breastfeeding policies can be developed as a result of the results to be obtained.

Risk of Fat Mass- and Obesity-Associated Gene-Dependent Obesogenic Programming by Formula Feeding Compared to Breastfeeding

It is the purpose of this review to compare differences in postnatal epigenetic programming at the level of DNA and RNA methylation and later obesity risk between infants receiving artificial formula feeding (FF) in contrast to natural breastfeeding (BF). FF bears the risk of aberrant epigenetic programming at the level of DNA methylation and enhances the expression of the RNA demethylase fat mass- and obesity-associated gene (FTO), pointing to further deviations in the RNA methylome. Based on a literature search through Web of Science, Google Scholar, and PubMed databases concerning the dietary and epigenetic factors influencing FTO gene and FTO protein expression and FTO activity, FTO's impact on postnatal adipogenic programming was investigated. Accumulated translational evidence underscores that total protein intake as well as tryptophan, kynurenine, branched-chain amino acids, milk exosomal miRNAs, NADP, and NADPH are crucial regulators modifying FTO gene expression and FTO activity. Increased FTO-mTORC1-S6K1 signaling may epigenetically suppress the WNT/β-catenin pathway, enhancing adipocyte precursor cell proliferation and adipogenesis. Formula-induced FTO-dependent alterations of the N6-methyladenosine (m6A) RNA methylome may represent novel unfavorable molecular events in the postnatal development of adipogenesis and obesity, necessitating further investigations. BF provides physiological epigenetic DNA and RNA regulation, a compelling reason to rely on BF.

Daytime sleep duration during infancy as an indicator for cognitive development at school age: a prospective cohort study

STUDY OBJECTIVES

The reduction in daytime sleep during early life is considered one of the indicators of the maturation of sleep patterns, which is closely associated with cognitive development. The current study aims to analyze the relationships between daytime sleep duration (DSD) during infancy and cognitive development at 6 and 10 years.

METHODS

The study included 262 mothers with their newborns from the Shanghai Sleep Birth Cohort Study, spanning 11 follow-ups from 42 days to 10 years. Sleep parameters were assessed using parent-reported questionnaires at each follow-up, and cognitive development was evaluated with the Wechsler Intelligence Scale for Children, fourth edition at 6 and 10 years.

RESULTS

Two distinct DSD trajectories in early childhood were identified: "typical DSD" (66.7%) and "infancy excessive DSD" (33.3%). Children in the "infancy excessive DSD" trajectory exhibited lower working memory scores than those in the "typical DSD" trajectory at 6 years (mean difference = 5.90, 95% confidence interval [1.83, 9.96], P = .005) and 10 years (mean difference = 4.37, 95% confidence interval [0.26, 8.48], P = .037). Additional analysis in a relatively homogeneous sample consistently showed correlations between DSD trajectories and working memory performance. No consistent significant differences were found in other domains of cognitive development.

CONCLUSIONS

Excessive daytime sleep during infancy may serve as an early indicator for poor working memory at school age. These findings raise concerns about the long-term cognitive development of infants with excessive DSD.

CITATION

Lin J, Jiang Y, Xiao X, et al. Daytime sleep duration during infancy as an indicator for cognitive development at school age: a prospective cohort study. J Clin Sleep Med. 2024;20(7):1069-1077.

The Effect of a Light-Dark Cycle on Premature Infants in the Neonatal Intensive Care Unit: A Randomized Controlled Study

PURPOSE

To investigate potential differences in discharge time, feeding methods and amounts, daily weight gain, vital signs, pain, and comfort levels among preterm infants born at 28-32 weeks' gestation who were hospitalized in the neonatal intensive care unit during long-term follow-up while implementing a light-dark cycle.

DESIGN AND METHODS

This is a randomized controlled study conducted with the support of a day-night cycle in premature infants born at 28-32 weeks' gestation and admitted to the neonatal intensive care unit of a teaching and research hospital affiliated with the Ministry of Health. The study compared the follow-up results from hospitalization to discharge over a period of 8 weeks.

RESULTS

50% of premature infants admitted to the unit are multiple pregnancies. There was no significant difference in discharge weight, comfort level, pain level, vital signs of the infants included in the study (p > 0.05). The optimal development of infant feeding patterns was examinedand it was observed that the study group had significantly improved before the control group in terms of the time to switch to full enteral feeding and oral feeding (p < 0,05). The daily weight gain of the babies was examined, it was seen that the weight gain was higher in the study group compared to the control group (p < 0,05). The mean duration of hospitalization was compared, it was seen that the babies in the study group were discharged significantly earlier (p < 0,05).

CONCLUSION

The study compared the long-term outcomes of premature babies hospitalized in neonatal intensive care and babies exposed to a light-dark cycle and regularly monitored in standard care. The results showed that the babies in the study group had higher daily weight gain and were discharged earlier than the control group. There were also no statistically significant differences in comfort and pain scores, vital signs or oxygen saturation between the study and control groups.

PRACTICE IMPLICATIONS

A light-dark cycle was found to be a feasible and promising intervention for infants at 28-32 weeks' gestation. It was a nurse-led management of care that could be integrated into the usual care of 28-32-week-old babies in neonatal units.

Is the insomnia phenotype the common denominator in LUTS during transition periods? An expert NOPIA research group review

AIMS

As people age, sleep stages and characteristics transition over time, but sleep deficits can profoundly impact health and cognitive functioning. Chronic sleep deprivation is linked to impaired attention and productivity, weakened immunity, increased risk of cardiovascular disease, obesity, and mental health disorders. Insomnia, obstructive sleep apnea syndrome, hormonal changes, nocturia, neurological disorders, and life events interfere with sleep patterns and some are linked to lower urinary tract symptoms (LUTS). This NOPIA symposium on Lifelong LUTS aimed to analyze the literature on associations between sleep and LUTS, generate ideas for future research, and explore whether there is support for the concept of lifelong LUTS in relation to changes in sleep throughout the lifespan.

METHODS

An international panel of experts took part in an online meeting addressing the role of lifelong LUTS in relationship to sleep and the brain organized by the NOPIA research group. The manuscript summarizes existing literature, hypotheses, future research ideas, and clinical recommendations.

RESULTS

Insomnia, sleep fragmentation, hyperarousal, and sensory processing disorders emerged as potential factors in the relationship between sleep and LUTS. Insomnia is often a persistent factor and may have been the initial symptom; however, it is often unrecognized and/or unaddressed in healthcare settings. By recognizing insomnia as a primary driver of various health issues, including nocturia, transitional care aims to address root causes and underlying problems earlier to initiate appropriate treatment.

CONCLUSIONS

A multidisciplinary approach with collaboration between healthcare professionals from various disciplines, such as urology, sleep medicine, gynecology, pediatrics, and geriatrics, is needed and should include validated measurements such as the insomnia severity index and sleep and voiding diaries. Ensuring ongoing follow-up and monitoring through transitional care is crucial for individuals with persistent sleep problems and LUTS, allowing issues that arise or fluctuate over the lifespan to be addressed.

Group-based sleep trajectories in children and adolescents: A systematic review

Sleep is crucial for health and development. Evidence indicates that sleep changes over time and distinct subgroups may experience different longitudinal patterns. This study systematically reviewed the studies that used latent trajectory modeling to investigate sleep trajectories of children and adolescents aged 0-18 years, and summarized the associated determinants and health-related outcomes. We searched PubMed, Embase, CENTRAL, PsycINFO, and Web of Science, identifying 46 articles that met our criteria. To ensure the reliability of the review, only studies rated as good or fair in terms of methodological quality were included, resulting in a total of 36 articles. Group-based trajectories were identified on several sleep dimensions (i.e., sleep duration, general and specific sleep problems, and bed-sharing behavior) and three or four trajectories were reported in most studies. There was a convergence trend across sleep duration trajectories during the first six years of life. Studies on specific sleep problem (i.e., insomnia, night-waking, and sleep-onset difficulties) typically identified two trajectories: consistent, minimal symptoms or chronic yet fluctuating symptoms. Lower socioeconomic status, maternal depression, and night feeding behaviors were the most frequently reported determinants of sleep trajectories. Membership in a group with certain adverse patterns (e.g., persistent short sleep duration) was associated with increased risks of multiple negative health-related conditions, such as obesity, compromised immunity, neurological problems, substance use, or internalizing/externalizing symptoms. Generally, there is potential to improve the quality of studies in this field. Causality is hard to be inferred within the current body of literature. Future studies could emphasize early life sleep, incorporate more assessment timepoints, use objective measures, and employ experimental design to better understand changes of and mechanisms behind the various sleep trajectories and guide targeted interventions for at-risk subpopulations.

Melatonin in Human Breast Milk and Its Potential Role in Circadian Entrainment: A Nod towards Chrononutrition?

Breastfeeding is the most appropriate source of a newborn's nutrition; among the plethora of its benefits, its modulation of circadian rhythmicity with melatonin as a potential neuroendocrine transducer has gained increasing interest. Transplacental transfer assures melatonin provision for the fetus, who is devoid of melatonin secretion. Even after birth, the neonatal pineal gland is not able to produce melatonin rhythmically for several months (with an even more prolonged deficiency following preterm birth). In this context, human breast milk constitutes the main natural source of melatonin: diurnal dynamic changes, an acrophase early after midnight, and changes in melatonin concentrations according to gestational age and during the different stages of lactation have been reported. Understudied thus far are the factors impacting on (changes in) melatonin content in human breast milk and their clinical significance in chronobiological adherence in the neonate: maternal as well as environmental aspects have to be investigated in more detail to guide nursing mothers in optimal feeding schedules which probably means a synchronized instead of mistimed feeding practice. This review aims to be thought-provoking regarding the critical role of melatonin in chrononutrition during breastfeeding, highlighting its potential in circadian entrainment and therefore optimizing (neuro)developmental outcomes in the neonatal setting.

Influence of physical exercise on negative emotions in college students: chain mediating role of sleep quality and self-rated health

Background

Negative emotions in college students are a significant factor affecting mental health, with suicide behaviors caused by negative emotions showing an annual increasing trend. Existing studies suggest that physical exercise is essential to alleviate negative feelings, yet the intrinsic mechanisms by which it affects negative emotions have not been fully revealed.

Objective

Negative emotions in college students represent a significant issue affecting mental health. This study investigates the relationship between physical exercise and negative emotions among college students, incorporating sleep quality and self-rated health (SRH) as mediators to analyze the pathway mechanism of how physical exercise affects students' negative emotions.

Methods

A cross-sectional study design was utilized, employing online questionnaires for investigation. The scales included the Physical Activity Rating Scale-3 (PARS-3), the Depression Anxiety Stress Scales-21 (DASS-21), the Pittsburgh Sleep Quality Index (PSQI), and the 12-Item Short Form Health Survey (SF-12), resulting in the collection of 30,475 valid questionnaires, with a validity rate of 91%. Chain mediation tests and Bootstrap methods were applied for effect analysis.

Results

The proportions of university students engaged in low, medium, and high levels of physical exercise were 77.6, 13.1, and 9.3%, respectively. The proportions of students experiencing "very severe" levels of stress, anxiety, and depression were 4.5, 10.9, and 3.6%, respectively. Physical exercise was significantly positively correlated with self-rated health (r = 0.194, p < 0.01), significantly negatively correlated with sleep quality (r = -0.035, p < 0.01), and significantly negatively correlated with stress, anxiety, and depression (r = -0.03, p < 0.01; r = -0.058, p < 0.01; r = -0.055, p < 0.01). Sleep quality was significantly negatively correlated with self-rated health (r = -0.242, p < 0.01). Mediation effect testing indicated that sleep quality and self-rated health partially mediated the relationship between physical exercise and negative emotions, with total effect, total direct effect, and total indirect effect values of -1.702, -0.426, and - 1.277, respectively.

Conclusion

College students primarily engage in low-intensity physical activity. Sleep quality and self-rated health mediate the impact of physical exercise on students' negative emotions. A certain level of physical activity can directly affect students' emotional states and indirectly influence their negative emotions via sleep and self-rated health. Regular engagement in physical activities primarily positively impacts emotional states by enhancing mood stability and overall emotional resilience.

Generalized Camera-Based Infant Sleep-Wake Monitoring in NICUs: A Multi-Center Clinical Trial

The infant sleep-wake behavior is an essential indicator of physiological and neurological system maturity, the circadian transition of which is important for evaluating the recovery of preterm infants from inadequate physiological function and cognitive disorders. Recently, camera-based infant sleep-wake monitoring has been investigated, but the challenges of generalization caused by variance in infants and clinical environments are not addressed for this application. In this paper, we conducted a multi-center clinical trial at four hospitals to improve the generalization of camera-based infant sleep-wake monitoring. Using the face videos of 64 term and 39 preterm infants recorded in NICUs, we proposed a novel sleep-wake classification strategy, called consistent deep representation constraint (CDRC), that forces the convolutional neural network (CNN) to make consistent predictions for the samples from different conditions but with the same label, to address the variances caused by infants and environments. The clinical validation shows that by using CDRC, all CNN backbones obtain over 85% accuracy, sensitivity, and specificity in both the cross-age and cross-environment experiments, improving the ones without CDRC by almost 15% in all metrics. This demonstrates that by improving the consistency of the deep representation of samples with the same state, we can significantly improve the generalization of infant sleep-wake classification.

Sleep and the sleep electroencephalogram in C57BL/6 and C3H/HeN mice

Different mouse strains used in biomedical research show different phenotypes associated with their genotypes. Two mouse strains commonly used in biomedical sleep research are C57Bl/6 and C3H/He, the strains differ in numerous aspects, including their ability to secrete melatonin as well as the expression of several sleep-related genes. However, sleep regulation has only limitedly been compared between C3H/HeN and C57Bl/6 mice. We therefore compared sleep-wake behaviour and EEG-measured spectral brain activity for C57bl/6 and C3H/HeN mice during a 12:12 h light: dark baseline and during and after a 6 h sleep deprivation. The C3H mice spent more time in NREM sleep around the light-dark transition and more time in REM sleep during the dark phase compared with C57bl/6 mice. The C3H mice also showed more EEG activity in the 4.5-7.5 Hz range during all stages and a stronger 24 h modulation of EEG power density in almost all EEG frequencies during NREM sleep. After the sleep deprivation, C3H mice showed a stronger recovery response, which was expressed in both a larger increase in EEG slow wave activity (SWA) and more time spent in NREM sleep. We show large differences regarding sleep architecture and EEG activity between C3H and C57bl/6 mice. These differences include the amount of waking during the late dark phase, the 24 h amplitude in EEG power density, and the amount of REM sleep during the dark phase. We conclude that differences between mouse strains should be considered when selecting a model strain to improve the generalisability of studies investigating biomedical parameters related to sleep and circadian rhythms.

Treatment for behavioral insomnia in young children with neurotypical development under 6 years of age: A systematic review

This literature review examines all treatments for behavioral insomnia in children under 6 years of age to determine which treatments have empirically demonstrated efficacy. Following PRISMA guidelines, three databases were investigated (Pubmed, Cochrane and Psychinfo) to select randomized controlled trials (RCTs) which assess treatments for behavioral insomnia in children under 6 years of age, all with neurotypical development. A total of 908 articles met the search criteria. 21 articles were selected and analyzed in their entirety for a total of 2363 children (ranging from 2 months to 6 years of age). Based on these studies, treatment of behavioral insomnia in young children under 6 years of age is primarily based on behavioral therapy. There is no evidence that pharmacological treatments are effective in the long term for neurotypical children. This review highlights the lack of RCTs in this field: new RCTs should be carried out among young children to refine and optimize the therapeutic approach and to address the risk of therapeutic abuse through the use of non-scientifically validated methods.

The role of perinatal maternal symptoms of depression, anxiety and pregnancy-specific anxiety for infant's self-regulation: A prospective longitudinal study

BACKGROUND

Maternal symptoms of anxiety and depression are highly prevalent during pregnancy and postpartum and have the potential to impact fetal development and offspring behavior. However, research on the effects of fetal exposure to maternal subclinical affective symptoms on infant self-regulation is still lacking. Self-regulation provides a fundamental precondition for healthy development and overall life success whereas dysfunctional self-regulation can lead to behavioral problems, poor academic achievement, social rejection, and physical/mental disorders. During pregnancy and infancy, children largely depend upon their mothers in order to successfully regulate their internal states. Given the high prevalence of mothers suffering from anxiety and depressive symptoms during pregnancy and after childbirth, the aim of the present study is to explore how maternal affective symptoms change during the pre- and postnatal period, and how measures obtained in pregnancy and beyond impact self-regulation in infants, as indicated by crying-, sleeping-, and/or feeding problems.

METHODS

This prospective longitudinal study investigates the effects of maternal symptoms of depression, anxiety, and pregnancy-specific anxiety on infant's self-regulation in N = 225 mother-infant dyads. Maternal affective symptoms were examined at five prenatal and three postnatal time-points using the Edinburgh Postnatal Depression Scale (EPDS), the State-Trait Anxiety Inventory (STAI) and the Pregnancy Related Anxiety Questionnaire Revised (PRAQ-R2). Infant's self-regulation was assessed twice - at the age of three and six months - using the Crying Feeding Sleeping Scale (SFS).

RESULTS

Maternal pregnancy-specific anxiety was the most significant predictor for infant self-regulatory problems. It predicted crying-, sleeping, and feeding problems and explained up to 18 % of the variance. Even when controlling for maternal postpartum affective symptoms, pregnancy-specific anxiety remained a significant predictor for infant self-regulation problems.

LIMITATIONS

Rather homogenous sample (high socioeconomic status). Data based on maternal reports of infant behavior.

CONCLUSIONS

Our results suggest that fetal exposure to maternal affective symptoms - specifically pregnancy-related anxiety - plays a substantial role in the development of infant self-regulation problems, potentially mediated by epigenetic modifications. Importantly, even though maternal symptoms of depression and anxiety only reached subclinical levels, they were predictive for infant crying-, sleeping-, and feeding problems. Our findings underline the importance of early prevention and clearly tailored interventions during pregnancy and postpartum to prevent adverse outcome for mother, child and family.

A systematic review of chronobiology for neonatal care units: What we know and what we should consider

A Cochrane 2016 review indicated cycled light might benefit neonatal health in hospital. We systematically reviewed chronobiological factors for neonatal health in hospital units, identifying 56 relevant studies on light-dark cycles, feeding, noise, massage therapy, rooming-in, incubators vs. cribs, neonatal units vs. homes, and time-of-day of birth. Empirical evidence for benefits from chronobiology is weaker than expected, including light. Mechanisms of clinical benefits are unclear (e.g., changes to sleep/activity vs. other circadian-regulated processes). Regarding light, studies concerning sleep and circadian-related outcomes predominate; yet, neonatologists may be more interested in weight gain and time spent in hospital. Generalisability of findings is limited as most studies targeted neonates in stable condition and without congenital anomalies. Further research is needed, in particular concerning potential circadian entraining signals such as timing of meals or medications. Longer-term outcomes (regarding e.g., neurodevelopment and infection), and who may be at risk from time-of-day of birth effects and why remain to be explored. Overall, there is promise and ample scope for research into how chronobiological factors affect health in hospitalised neonates.

Ontogeny of the circadian system: a multiscale process throughout development

The 24 h (circadian) timing system develops in mammals during the perinatal period. It carries out the essential task of anticipating daily recurring environmental changes to identify the best time of day for each molecular, cellular, and systemic process. Although significant knowledge has been acquired about the organization and function of the adult circadian system, relatively little is known about its ontogeny. During the perinatal period, the circadian system progressively gains functionality under the influence of the early environment. This review explores current evidence on the development of the circadian clock in mammals, highlighting the multilevel complexity of the process and the importance of gaining a better understanding of its underlying biology.

Beyond Conventional Therapies: Molecular Dynamics of Alzheimer's Treatment through CLOCK/BMAL1 Interactions

BACKGROUND

Alzheimer's Disease (AD) represents a neurodegenerative disorder characterized by cognitive and behavioral impairments significantly hindering social and occupational functioning. Melatonin, a hormone pivotal in regulating the body's intrinsic circadian rhythm, also acts as a catalyst in the breakdown of beta-amyloid deposits, offering a promising therapeutic approach for AD. The upregulation of Brain and Muscle ARNT-Like 1 (Bmal1) gene expression, stimulated by melatonin, emerges as a potential contributor to AD intervention. Current pharmacological interventions, such as FDA-approved cholinesterase inhibitors and the recently authorized monoclonal antibody, Lecanemab, are utilized in AD management. However, the connection between these medications and Bmal1 remains insufficiently explored.

OBJECTIVE

This study aims to investigate the molecular effects of FDA-endorsed drugs on the CLOCK: Bmal1 dimer. Furthermore, considering the interactions between melatonin and Bmal1, this research explores the potential synergistic efficacy of combining these pharmaceutical agents with melatonin for AD treatment.

METHODS

Using molecular docking and MM/PBSA methodologies, this research determines the binding affinities of drugs within the Bmal1 binding site, constructing interaction profiles.

RESULTS

The findings reveal that, among FDA-approved drugs, galanthamine and donepezil demonstrate notably similar binding energy values to melatonin, interacting within the Bmal1 binding site through analogous amino acid residues and functional groups.

CONCLUSION

A novel therapeutic approach emerges, suggesting the combination of melatonin with Lecanemab as a monoclonal antibody therapy. Importantly, prior research has not explored the effects of FDA-approved drugs on Bmal1 expression or their potential for synergistic effects.

Differential Expression of Circadian Clock Genes in the Bovine Neuroendocrine Adrenal System

Knowledge of circadian rhythm clock gene expression outside the suprachiasmatic nucleus is increasing. The purpose of this study was to determine whether expression of circadian clock genes differed within or among the bovine stress axis tissues (e.g., amygdala, hypothalamus, pituitary, adrenal cortex, and adrenal medulla). Tissues were obtained at an abattoir from eight mature nonpregnant Brahman cows that had been maintained in the same pasture and nutritional conditions. Sample tissues were stored in RNase-free sterile cryovials at -80 °C until the total RNA was extracted, quantified, assessed, and sequenced (NovaSeq 6000 system; paired-end 150 bp cycles). The trimmed reads were then mapped to a Bos taurus (B. taurus) reference genome (Umd3.1). Further analysis used the edgeR package. Raw gene count tables were read into RStudio, and low-expression genes were filtered out using the criteria of three minimum reads per gene in at least five samples. Normalization factors were then calculated using the trimmed mean of M values method to produce normalized gene counts within each sample tissue. The normalized gene counts important for a circadian rhythm were analyzed within and between each tissue of the stress axis using the GLM and CORR procedures of the Statistical Analysis System (SAS). The relative expression profiles of circadian clock genes differed (p < 0.01) within each tissue, with neuronal PAS domain protein 2 (NPAS2) having greater expression in the amygdala (p < 0.01) and period circadian regulator (PER1) having greater expression in all other tissues (p < 0.01). The expression among tissues also differed (p < 0.01) for individual circadian clock genes, with circadian locomotor output cycles protein kaput (CLOCK) expression being greater within the adrenal tissues and nuclear receptor subfamily 1 group D member 1 (NR1D1) expression being greater within the other tissues (p < 0.01). Overall, the results indicate that within each tissue, the various circadian clock genes were differentially expressed, in addition to being differentially expressed among the stress tissues of mature Brahman cows. Future use of these findings may assist in improving livestock husbandry and welfare by understanding interactions of the environment, stress responsiveness, and peripheral circadian rhythms.

Not simply a matter of parents-Infants' sleep-wake patterns are associated with their regularity of eating

In adults there are indications that regular eating patterns are related to better sleep quality. During early development, sleep and eating habits experience major maturational transitions. Further, the bacterial landscape of the gut microbiota undergoes a rapid increase in complexity. Yet little is known about the association between sleep, eating patterns and the gut microbiota. We first hypothesized that higher eating regularity is associated with more mature sleep patterns, and second, that this association is mediated by the maturational status of the gut microbiota. To test this hypothesis, we performed a longitudinal study in 162 infants to assess actigraphy, diaries of sleep and eating times, and stool microbiota composition at ages 3, 6 and 12 months. To comprehensively capture infants' habitual sleep-wake patterns, 5 sleep composites that characterize infants' sleep habits across multiple days in their home environment were computed. To assess timing of eating habits, we developed an Eating Regularity Index (ERI). Gut microbial composition was assessed by 16S rRNA gene amplicon sequencing, and its maturation was assessed based on alpha diversity, bacterial maturation index, and enterotype. First, our results demonstrate that increased eating regularity (higher ERI) in infants is associated with less time spent awake during the night (sleep fragmentation) and more regular sleep patterns. Second, the associations of ERI with sleep evolve with age. Third, the link between infant sleep and ERI remains significant when controlling for parents' subjectively rated importance of structuring their infant's eating and sleeping times. Finally, the gut microbial maturational markers did not account for the link between infant's sleep patterns and ERI. Thus, infants who eat more regularly have more mature sleep patterns, which is independent of the maturational status of their gut microbiota. Interventions targeting infant eating rhythm thus constitute a simple, ready-to-use anchor to improve sleep quality.

Review on age-related differences in non-visual effects of light: melatonin suppression, circadian phase shift and pupillary light reflex in children to older adults

Physiological effects of light exposure in humans are diverse. Among them, the circadian rhythm phase shift effect in order to maintain a 24-h cycle of the biological clock is referred to as non-visual effects of light collectively with melatonin suppression and pupillary light reflex. The non-visual effects of light may differ depending on age, and clarifying age-related differences in the non-visual effects of light is important for providing appropriate light environments for people of different ages. Therefore, in various research fields, including physiological anthropology, many studies on the effects of age on non-visual functions have been carried out in older people, children and adolescents by comparing the effects with young adults. However, whether the non-visual effects of light vary depending on age and, if so, what factors contribute to the differences have remained unclear. In this review, results of past and recent studies on age-related differences in the non-visual effects of light are presented and discussed in order to provide clues for answering the question of whether non-visual effects of light actually vary depending on age. Some studies, especially studies focusing on older people, have shown age-related differences in non-visual functions including differences in melatonin suppression, circadian phase shift and pupillary light reflex, while other studies have shown no differences. Studies showing age-related differences in the non-visual effects of light have suspected senile constriction and crystalline lens opacity as factors contributing to the differences, while studies showing no age-related differences have suspected the presence of a compensatory mechanism. Some studies in children and adolescents have shown that children's non-visual functions may be highly sensitive to light, but the studies comparing with other age groups seem to have been limited. In order to study age-related differences in non-visual effects in detail, comparative studies should be conducted using subjects having a wide range of ages and with as much control as possible for intensity, wavelength component, duration, circadian timing, illumination method of light exposure, and other factors (mydriasis or non-mydriasis, cataracts or not in the older adults, etc.).

Maternal-infant interaction quality is associated with child NR3C1 CpG site methylation at 7 years of age

OBJECTIVE

Infancy is both a critical window for hypothalamic-pituitary-adrenal (HPA) axis development, and a sensitive period for social-emotional influences. We hypothesized that the social-emotional quality of maternal-infant interactions are associated with methylation of HPA-axis gene NR3C1 later in childhood.

METHODS

Using a subsample of 114 mother-infant pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC), linear regression models were created to predict variance in methylation of seven selected CpG sites from NR3C1 in whole blood at age 7 years, including the main predictor variable of the first principal component score of observed maternal-infant interaction quality (derived from the Thorpe Interaction Measure at 12 months of age) and covariates of cell-type proportion, maternal financial difficulties and marital status at 8 months postnatal, child birthweight, and sex.

RESULTS

CpG site cg27122725 methylation was negatively associated with warmer, more positive maternal interaction with her infant (β = 0.19, p = .02, q = 0.13). In sensitivity analyses, the second highest quartile of maternal behavior (neutral, hesitant behavior) was positively associated with cg12466613 methylation. The other five CpG sites were not significantly associated with maternal-infant interaction quality.

CONCLUSIONS

Narrow individual variation of maternal interaction with her infant is associated with childhood methylation of two CpG sites on NR3C1 that may be particularly sensitive to environmental influences. Infancy may be a sensitive period for even small influences from the social-emotional environment on the epigenetic determinants of HPA-axis function.

Supporting and Enhancing NICU Sensory Experiences (SENSE), 2nd Edition: An Update on Developmentally Appropriate Interventions for Preterm Infants

The Supporting and Enhancing NICU Sensory Experiences (SENSE) program promotes consistent, age-appropriate, responsive, and evidence-based positive sensory exposures for preterm infants each day of NICU hospitalization to optimize infant and parent outcomes. The initial development included an integrative review, stakeholder input (NICU parents and healthcare professionals), and feasibility focus groups. To keep the program updated and evidence-based, a review of the recent evidence and engagement with an advisory team will occur every 5 years to inform changes to the SENSE program. Prior to the launch of the 2nd edition of the SENSE program in 2022, information from a new integrative review of 57 articles, clinician feedback, and a survey identifying the barriers and facilitators to the SENSE program's implementation in a real-world context were combined to inform initial changes. Subsequently, 27 stakeholders (neonatologists, nurse practitioners, clinical nurse specialists, bedside nurses, occupational therapists, physical therapists, speech-language pathologists, and parents) carefully considered the suggested changes, and refinements were made until near consensus was achieved. While the 2nd edition is largely the same as the original SENSE program, the refinements include the following: more inclusive language, clarification on recommended minimum doses, adaptations to allow for variability in how hospitals achieve different levels of light, the addition of visual tracking in the visual domain, and the addition of position changes in the kinesthetic domain.

Anemia in pregnancy and sleep of 6-month-old infants: A prospective cohort study

Objective

Anemia has been reported to adversely influence sleep in infants. However, the association between anemia in pregnancy and infant sleep remains unclear. We aimed to examine the association between maternal anemia in pregnancy and sleep parameters of 6-month-old infants.

Methods

We enrolled 2,410 mother-infant pairs between 2018 and 2021 in Hefei. Data on maternal hemoglobin concentration were collected at 24–28 gestational weeks from the electronic medical records of the hospitals. Nocturnal and daytime sleep duration, number of night awakenings, nocturnal wakefulness, and sleep latency of infants aged 6 months were measured using the Brief Infant Sleep Questionnaire with five items. A restricted cubic spline model was used to examine the relationship between maternal hemoglobin concentration and infant nocturnal sleep duration after adjusting for potential confounders.

Results

In our study, 807 (33.5%) mothers had anemia during pregnancy. Compared to infants born to mothers without anemia, infants born to mothers with anemia in pregnancy had shorter nocturnal sleep duration [mean (SD), 560.29 (79.57) mins vs. 574.27 (75.36) mins] at the age of 6 months. Subgroup analysis showed consistent significant differences in nocturnal sleep duration between infant born to anemic and non-anemic mothers, except in case of stratification by preterm birth [mean difference (mins), 2.03 (95% CI, −20.01, −24.07)] and pre-pregnancy obesity [mean difference (mins), −0.85 (95% CI, −16.86, −15.16)]. A J-shaped nonlinear correlation curve was observed between maternal hemoglobin concentration and infant nocturnal sleep duration. Compared with mothers without daily iron supplementation, mothers who had daily iron supplementation had higher hemoglobin concentrations [mean (SD), 112.39 (11.33) g/L vs. 110.66 (10.65) g/L] at delivery and their infants had longer nocturnal sleep duration [mean (SD), 565.99 (82.46) mins vs. 553.66 (76.03) mins].

Conclusion

Anemia in pregnancy may have an adverse influence on the sleep of 6-mon-old infants, and the relationship between maternal hemoglobin concentration and nocturnal sleep duration is nonlinear.

Understanding the relationships between physiological and psychosocial stress, cortisol and cognition

Stress is viewed as a state of real or perceived threat to homeostasis, the management of which involves the endocrine, nervous, and immune systems. These systems work independently and interactively as part of the stress response. The scientific stress literature, which spans both animal and human studies, contains heterogeneous findings about the effects of stress on the brain and the body. This review seeks to summarise and integrate literature on the relationships between these systems, examining particularly the roles of physiological and psychosocial stress, the stress hormone cortisol, as controlled by the hypothalamic-pituitary-adrenal (HPA) axis, and the effects of stress on cognitive functioning. Health conditions related to impaired HPA axis functioning and their associated neuropsychiatric symptoms will also be considered. Lastly, this review will provide suggestions of clinical applicability for endocrinologists who are uniquely placed to measure outcomes related to endocrine, nervous and immune system functioning and identify areas of intervention.

Associations between chronotype, sleep quality, maternal mental health, and child development in mother-infant dyads

OBJECTIVE/BACKGROUND

Studies on circadian rhythms throughout development and their physiological and behavioral impacts at early stages are still scarce. Previous studies have shown that mother-infant interactions are important for both sleep and child development. In this cross-sectional study we investigated whether infants' chronotype, sleep and development were associated with their respective mothers' chronotype, sleep, mental health and socioeconomic status.

PATIENTS/METHODS

the following were used to evaluate mothers: the Morningness-Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Self-Reporting Questionnaire 20 (SRQ-20). To assess the infants' characteristics, the following were used: the 19th question from the Morningness-Eveningness Questionnaire (MEQ), infant nocturnal midpoint of sleep (iMSF), Brief Infant Sleep Questionnaire (BISQ) and Ages and Stages Questionnaire-3 (ASQ3). Socioeconomic aspects were assessed using the Brazilian Economic Class Criterion of the Brazilian Association of Research Companies (ABEP).

RESULTS

A hundred and eight mother-infant dyads participated in the study. Sleep disorders were observed in 38 (35%) infants and atypical development (ASQ3) in 35 (32%). The infants' sleep phases were partially explained by the mother's chronotype. Infants' sleep duration was negatively correlated with sleep latency, which was higher in the group with atypical development. Mothers of infants with sleep disorders or discordant chronotypes (32%) had higher Pittsburgh scores (worse sleep quality) and higher SRQ-20 scores (screen for Common Mental Disorders).

CONCLUSIONS

We found evidence for the contribution of sleep quality and chronotypes to mothers' mental health and infant development. However, further studies are needed to confirm the influence of sleep and circadian phenotypes in the early stages.

Circle(s) of Life: The Circadian Clock from Birth to Death

Most lifeforms on earth use endogenous, so-called circadian clocks to adapt to 24-h cycles in environmental demands driven by the planet’s rotation around its axis. Interactions with the environment change over the course of a lifetime, and so does regulation of the circadian clock system. In this review, we summarize how circadian clocks develop in humans and experimental rodents during embryonic development, how they mature after birth and what changes occur during puberty, adolescence and with increasing age. Special emphasis is laid on the circadian regulation of reproductive systems as major organizers of life segments and life span. We discuss differences in sexes and outline potential areas for future research. Finally, potential options for medical applications of lifespan chronobiology are discussed.

Precision caffeine therapy for apnea of prematurity and circadian rhythms: New possibilities open up

Caffeine is the globally consumed psychoactive substance and the drug of choice for the treatment of apnea of prematurity (AOP), but its therapeutic effects are highly variable among preterm infants. Many of the molecular underpinnings of the marked individual response have remained elusive yet. Interestingly, the significant association between Clock gene polymorphisms and the response to caffeine therapy offers an opportunity to advance our understanding of potential mechanistic pathways. In this review, we delineate the functions and mechanisms of human circadian rhythms. An up-to-date advance of the formation and ontogeny of human circadian rhythms during the perinatal period are concisely discussed. Specially, we summarize and discuss the characteristics of circadian rhythms in preterm infants. Second, we discuss the role of caffeine consumption on the circadian rhythms in animal models and human, especially in neonates and preterm infants. Finally, we postulate how circadian-based therapeutic initiatives could open new possibilities to promote precision caffeine therapy for the AOP management in preterm infants.

Effect of a standardized maternal meal on fetal middle cerebral artery Doppler indices: A single-blinded crossover study

Objective

Measures of Doppler blood flow velocity profiles are an integral part of monitoring fetal well-being during pregnancy. These examinations are performed at different times of the day and at different maternal meal states. In uncomplicated pregnancies, we assessed the effect of a standardized maternal meal on middle cerebral artery (MCA) and umbilical artery (UA) Doppler blood flow velocity pulsatility indices (PIs) and MCA peak systolic velocity (PSV).

Methods

In this prospective single-blinded crossover study 25 healthy women were examined at 36 weeks of pregnancy. The first examination was performed in the morning following overnight fast, and repeated after extended fast (state A), and after a standard breakfast meal (state B).

Results

Irrespective of maternal prandial status, the MCA-PI values were lower in the 2^nd compared to the 1^st examination (-0.187; p = 0.071, and -0.113; p = 0.099, state A and B, respectively). Compared to the values in the 1^st examination, the UA-PI values, were higher after extended fast (0.014; p = 0.436), and lower post-prandially (-0.036; p = 0.070). The difference (state B minus state A) between the meal states were not significant (0.074; p = 0.487 and -0.050; p = 0.058, for MCA-PI and UA-PI, respectively). Adjusting for the possible influence of fetal heart rate on MCA-PI and UA-PI, the differences between meal states remained non-significant (p = 0.179, p = 0.064, respectively). The MCA-PSV values increased after the meal (6.812; p = 0.035), whereas no increase was observed following extended fast (0.140; p = 0.951). The difference in MCA-PSV values between the two meal states was not significant (6.672; p = 0.055).

Conclusion

Our results demonstrate possible diurnal variations in MCA-PI and UA-PI, with and without adjustment for fetal heart rate, that seem to be unaffected by maternal meal intake in healthy pregnancies.