Melatonina, lactancia materna y sueño: revisión del tema / Melatonin, breastfeeding and sleep: topic review

Se revisa en el binomio madre-recién nacidos o/y lactantes, los diferentes ritmos circadianos, especialmente del sueño, la secreción de melatonina y las características de la leche materna. Se aconseja manejo para evitar la cronodisrupción

It is reviewed in the binomial mother-newborns or/and infants, the different circadian rhythms, especially sleep, melatonin secretion and the characteristics of breast milk. Handling is advised to avoid chrono disruption

Prevalência e fatores associados ao burnout em médicos durante a pandemia da covid-19 / Prevalence and factors associated with burnout in physicians during the covid-19 pandemic

Introdução: A pandemia por covid-19 acentuou a demanda de atendimento nos serviços de saúde, com maior sobrecarga de trabalho aos profissionais de saúde, especialmente os médicos. Essa sobrecarga pareceu maior, no início da pandemia, nos médicos que estão na linha de frente do atendimento, dada a maior chance de serem acometidos pela própria doença. Embora já se saiba que há fatores individuais, organizacionais e distúrbios do sono para desenvolver o burnout em profissionais de saúde, saber se a condição resultante do atendimento médico na linha de frente a pacientes com covid-19 afetou essa associação entre o burnout, pode abrir mais possibilidades para apoio a esses profissionais. Objetivos: A proposta da pesquisa é estimar a prevalência do burnout e possíveis fatores individuais, organizacionais e de distúrbios do sono associados ao esgotamento em médicos de todas as regiões do país durante a pandemia de covid-19. Nesse sentido, o objetivo deste estudo foi avaliar a associação de fatores sociodemográficos (sexo e idade) e de, fatores relacionados à organização do trabalho (carga horária e local de trabalho), assim como a presença de distúrbios do sono (insônia, qualidade e quantidade de sono) com o burnout em médicos em um período no primeiro ano da pandemia de covid-19. Métodos: O estudo transversal foi realizado a partir de um banco de dados subsidiário coletado no período de 28 de maio a 28 de junho de 2020, elaborado por especialista do sono, de uma amostra de 2639 médicos das cinco regiões do Brasil com n=256 (9,7%) de perda de respostas. O questionário respondido consta de dados sociodemográficos e sobre distúrbios do sono em que foram realizadas estatística descritiva e testes de estatística inferencial. Resultados: A amostra de 2.639 médicos teve 256 (9,7%) perdas por questionários incompletos, constituindo, portanto, 2.374 (90,3%) profissionais. A prevalência de burnout encontrada antes da pandemia foi de 18,9% e aumentou para 31,3% durante o período da coleta de dados na pandemia, pela análise do componente de esgotamento emocional. Os fatores associados as maiores chances de burnout, segundo a análise de regressão, incluem a faixa etária de 25 a 39 anos (OR=2,76; IC95%=1,94-3,92); o sexo feminino (OR=1,67; IC95%=1,34-2,08); a atuação na linha de frente (OR=1,62; IC95%=1,30-2,02); o sono mais curto e de pior qualidade em relação ao período anterior à pandemia (OR=6,39; IC95%= 4,99-8,17) e não trabalhar em home office (OR=1,31; IC95%= 1,08-1,60). Conclusão: Os resultados desse estudo evidenciaram que os fatores com maior chance de desenvolvimento de burnout em médicos foram a faixa etária de jovem adulto, o sexo feminino, o trabalho na linha de frente, o sono curto e de má qualidade, além do trabalho presencial. Portanto, o presente estudo identificou pontos importantes para nortear o planejamento de ações preventivas ao burnout em médicos, considerando os fatores sociodemográficos, as condições de trabalho e aspectos relacionados ao sono, as quais são necessárias para garantir a qualidade e a continuidade de prestação de assistência à saúde da população, particularmente em emergências sanitárias.

Introduction: The covid-19 pandemic has accentuated the demand in health services with a greater workload for health professionals, especially physicians. This burden seemed greater, at the beginning of the pandemic, for physicians who are on the front line of care, given the greater chance of being affected by the disease itself. Although it is already known that there are individual and organizational and sleep disturbance factors for the development burnout in healthcare professionals, knowing whether the condition resulting from front line care of patients with covid-19 has affected this association between burnout may open up more possibilities. to support these professionals. Objectives: In this research, we propose to estimate the prevalence of burnout and possible individual, organizational factors and sleep disturbance factors associated with burnout in physicians from all regions of the country during the covid-19 pandemic. In this sense, the objective of this study was to evaluate the association of sociodemographic factors (gender and age) and factors related to work organization (workload and place of work), as well as the presence of sleep disorders (insomnia, quality and amount of sleep) with burnout in physicians in a period in the first year of the covid-19 pandemic. Methods: The cross-sectional study was carried out from a subsidiary database collected from May 28 to June 28, 2020, prepared by a sleep specialist, from a sample of 2639 physicians from the five regions of Brazil with n 256 (9, 7%) of lost responses. The questionnaire answered consists of sociodemographic data and data on sleep disorders in which descriptive statistics and inferential statistics tests were performed. Results: From a sample of 2,639 physicians, with 2,374 (90.3%) professionals who answered the questionnaire completely and losses of 256 (9.7%) due to incomplete questionnaires. The prevalence of burnout found before the pandemic was 18.9% and increased to 31.3% during the period of data collection in the pandemic, according to the analysis of the emotional exhaustion component. Factors associated with greater chances of burnout, according to regression analysis, include the age group from 25 to 39 years old (OR=2,76; IC95%=1,94- 3,92); the female gender (OR=1,67; IC95%=1,34-2,08); performance on the front line (OR= 1,62; IC95%=1,30-2,02); shorter and worse quality sleep compared to the period before the pandemic (OR=6,39; IC95%= 4,99-8,17) and not work at home office (OR=1,31; IC95%= 1,08-1,60). Conclusion: The results of this study showed that the factors with a greater chance of developing burnout in physicians were the age group of young adult, female gender, frontline work, short and poor quality sleep, in addition to face-to-face work .Therefore, the present study identified important points to guide the planning of preventive actions against burnout in physicians, considering sociodemographic factors, working conditions and aspects related to sleep, which are necessary to guarantee the quality and continuity of health care for the population, particularly in health emergency situations.

Atividade locomotora de Culex quinquefasciatus (Diptera: Culicidae) em condições de laboratório / Locomotor activity of Culex quinquefasciatus (Diptera: Culicidae) under laboratory conditions

Ritmos biológicos de insetos vetores têm sido estudados com o objetivo de melhor compreender seus comportamentos e traçar estratégias de controle mais eficientes para reduzir a disseminação de patógenos. Culex quinquefasciatus possui competência vetorial para diversos patógenos de importância médica, como a filária causadora da Filariose Bancroftiana e o arbovírus West Nile (WNV). O presente trabalho tem como objetivo estudar a atividade locomotora de Cx. quinquefasciatus em diferentes condições fisiológicas, comparando machos, fêmeas virgens, fêmeas inseminadas, fêmeas alimentadas com sangue e fêmeas inseminadas e alimentadas com sangue. Além disso, comparamos a atividade locomotora de fêmeas inseminadas por cópula com machos com a de fêmeas inseminadas a partir da inoculação intratorácica de extrato de glândulas acessórias de seus machos coespecíficos. Nossos resultados mostraram que a atividade locomotora de machos e fêmeas de Cx. quinquefasciatus é noturna, com pico pronunciado no apagar das luzes. Observamos que tanto as fêmeas virgens quanto as inseminadas, após alimentação sanguínea, apresentam redução da atividade locomotora durante a escotofase em comparação com os demais grupos, especialmente as inseminadas e alimentadas com sangue. Em contrapartida, as fêmeas inseminadas e não alimentadas apresentaram aumento significativo na atividade locomotora durante a escotofase em comparação aos demais grupos. Ao compararmos os grupos de fêmeas não injetadas - virgens e inseminadas - com os grupos das fêmeas injetadas, observamos que estas apresentaram menor atividade locomotora do que aquelas. Entre as não injetadas, fêmeas inseminadas apresentaram maior atividade locomotora do que as virgens, enquanto, entre os grupos das injetadas, as fêmeas virgens inoculadas com glândulas acessórias de machos coespecíficos apresentaram maior atividade do que as inseminadas injetadas com solução salina. Esse estudo fornece importantes informações acerca da atividade locomotora dessa espécie, que podem ajudar na compreensão da dinâmica de transmissão de patógenos, direcionar novas pesquisas, além de auxiliar na elaboração de estratégias de vigilância e controles.

Biological rhythms of insect vectors have been studied for better understanding their behavior and designing more efficient control strategies to reduce the spread of pathogens. Culex quinquefasciatus has vector competence for several pathogens of medical importance, such as the filaria that causes Bancroftian Filariasis and the West Nile arbovirus (WNV). The present study aims to evaluate the locomotor activity of Cx. quinquefasciatus in different physiological conditions, comparing males, virgin females, inseminated females, blood-fed females and inseminated and blood-fed females. In addition, we compared the locomotor activity of females inseminated by mating with males with that of females inseminated by intrathoracic inoculation of accessory gland extract from their conspecific males. Our results showed that the locomotor activity of males and females of Cx. quinquefasciatus is nocturnal, with a pronounced peak at the lights-off. We observed that both virgin and inseminated females, after blood feeding, showed reduced locomotor activity during scotophase compared to the other groups, especially inseminated and blood fed females. In contrast, inseminated and unfed females showed a significant increase in locomotor activity during scotophase compared to the other groups. When comparing the groups of non-injected females - virgin and inseminated - with the groups of injected females, we observed that the latter showed lower locomotor activity than the former. Among non-injected females, inseminated females showed greater locomotor activity than virgin ones, whereas, among injected groups, virgin females inoculated with accessory glands from conspecific males showed greater activity than inseminated females injected with saline solution. This study provides important information about the locomotor activity of this species, which can help in understanding the dynamics of pathogen transmission, direct new research, and help in the development of surveillance and control strategies.

Research progress in control strategies of biological clock disorder / 生理学报

Circadian clock is an internal mechanism evolved to adapt to cyclic environmental changes, especially diurnal changes. Keeping the internal clock in synchronization with the external clock is essential for health. Mismatch of the clocks due to phase shift or disruption of molecular clocks may lead to circadian disorders, including abnormal sleep-wake cycles, as well as disrupted rhythms in hormone secretion, blood pressure, heart rate, body temperature, etc. Long-term circadian disorders are risk factors for various common critical diseases such as metabolic diseases, cardiovascular diseases, and tumor. To prevent or treat the circadian disorders, scientists have conducted extensive research on the function of circadian clocks and their roles in the development of diseases, and screened hundreds of thousands of compounds to find candidates to regulate circadian rhythms. In addition, melatonin, light therapy, exercise therapy, timing and composition of food also play a certain role in relieving associated symptoms. Here, we summarized the progress of both drug- and non-drug-based approaches to prevent and treat circadian clock disorders.

Circadian rhythm in prostate cancer: time to take notice of the clock / 亚洲男科学杂志(英文版)

The circadian clock is an evolutionary molecular product that is associated with better adaptation to changes in the external environment. Disruption of the circadian rhythm plays a critical role in tumorigenesis of many kinds of cancers, including prostate cancer (PCa). Integrating circadian rhythm into PCa research not only brings a closer understanding of the mechanisms of PCa but also provides new and effective options for the precise treatment of patients with PCa. This review begins with patterns of the circadian clock, highlights the role of the disruption of circadian rhythms in PCa at the epidemiological and molecular levels, and discusses possible new approaches to PCa therapy that target the circadian clock.

Effects of circadian rhythm on the development of dental hard tissues / 中华口腔医学杂志

Circadian rhythm is regulated by circadian clock, which is formed by the body response to external cyclic stimuli through the endogenous circadian clock. Circadian rhythm disturbance is closely related to the risks of a variety of diseases, and its impact on oral health cannot be ignored. Exploring the relationship and related molecular mechanism between circadian rhythm and dental hard tissues development are helpful to deeply understand the pathogenesis of developmental defects on these tissues, which could provide a theoretical basis for prevention and treatment on disorders of dental hard tissues. In order to provide guidance for the disease prevention and treatment, based on the summarization of current research progress, this paper focuses on the involvement of biorhythm in the development of tooth hard tissues as well as the disturbance of circadian rhythm on the formation of enamel and dentin, and analyzes the related regulating mechanism of circadian rhythm and genes during the development of tooth hard tissues.

Regulation of ischemic stroke by circadian rhythm and intervention by traditional Chinese medicine / 中国中药杂志

Circadian rhythm is an internal regulatory mechanism formed in organisms in response to the circadian periodicity in the environment, which modulates the pathophysiological events, occurrence and development of diseases, and the response to treatment in mammals. It significantly influences the susceptibility, injury, and recovery of ischemic stroke, and the response to therapy. Accumulating evidence indicates that circadian rhythms not only regulate the important physiological factors of ischemic stroke events, such as blood pressure and coagulation-fibrinolysis system, but also participate in the immuno-inflammatory reaction mediated by glial cells and peripheral immune cells after ischemic injury and the regulation of neurovascular unit(NVU). This article aims to link molecular, cellular, and physiological pathways in circadian biology to the clinical consequences of ischemic stroke and to illustrate the impact of circadian rhythms on ischemic stroke pathogenesis, the regulation of NVU, and the immuno-inflammatory responses. The regulation of circadian rhythm by traditional Chinese medicine is reviewed, and the research progress of traditional Chinese medicine intervention in circadian rhythm is summarized to provide a reasonable and valuable reference for the follow-up traditional Chinese medicine research and molecular mechanism research of circadian rhythm.

Impacto de un curso electivo sobre ritmo circadiano y salud / Impact on an elective course on circadian rhythm and health

Fundamento: el análisis del impacto de la gestión docente es un requerimiento de la responsabilidad social universitaria. Objetivo: analizar el impacto del curso electivo Ritmo Circadiano y Salud, a través de la apreciación de los estudiantes, en la Facultad de Ciencias Médicas "Salvador Allende", durante el curso 2022-2023. Métodos: se desarrolló una investigación descriptiva, no experimental, con enfoque cualitativo, aplicando la metodología del estudio de caso. Se utilizaron métodos teóricos: análisis-síntesis e inducción-deducción, y empíricos: revisión documental y entrevista grupal a estudiantes. Resultados: de manera unánime se manifestó por los estudiantes la adquisición de conocimientos nuevos, de importancia para la práctica profesional, mediante el asesoramiento en el procesamiento de información, para la participación en una actividad virtual no conocida, así como la posibilidad de vivenciar en su entorno una problemática de salud asociada al tema del curso. Conclusiones: la apreciación por los estudiantes participantes del curso electivo Ritmo Circadiano y Salud, indicó un impacto positivo desde los puntos de vista cognitivo, educativo y social.

Background: the analysis of the impact of teaching management is a requirement of university social responsibility. Objective: to analyze the impact of the elective course Circadian Rhythm and Health, through the appreciation of the students, in the "Salvador Allende" Faculty of Medical Sciences, during the 2022-2023 academic year. Method: a descriptive, non-experimental investigation was developed, with a qualitative approach, applying the case study methodology. Theoretical methods were used: analysis-synthesis and induction-deduction, and empirical ones: documentary review and group interview with students. Results: the students unanimously expressed the acquisition of new important knowledge for professional practice, through advice on information processing, for participation in an unknown virtual activity, as well as the possibility of experiencing in their environment a health problem associated with the topic of the course. Conclusions: the appreciation by the participating students of the elective course Circadian Rhythm and Health, indicated a positive impact from the cognitive, educational and social points of view.

Bruxismo do sono e em vigília em adolescentes: prevalência, fatores associados e análise de caminhos / Sleep and awake bruxism in adolescents: prevalence, associated factors and pathways to occurrence

O Bruxismo é um comportamento, com atividade muscular mastigatória, que pode apresentar-se como bruxismo do sono (BS) e bruxismo em vigília (BV). Possui etiologia multifatorial, sendo pouco explorado entre adolescente. Essa tese é composta por dois artigos que avaliam a prevalência, fatores associados e análise de caminhos. O objetivo do artigo 1 (n=403) foi reconhecer os caminhos que influenciam a ocorrência de provável bruxismo do sono (PBS) e provável bruxismo em vigília (PBV) em adolescentes. O artigo 2 (n=342) objetivou avaliar a associação entre PBV e hábitos de morder, satisfação de vida, caracteristicas do sono e perfil cronotipo em adolescentes, por meio de um estudo caso-controle. Com aprovação do comitê de ética institucional, participaram do estudo adolescentes de 12 a 19 anos de idade, regularmente matriculados em escolas públicas e privadas de Belo Horizonte. Os pais/cuidadores responderam a um questionário sobre características do sono de seus filhos. Os adolescentes responderam aos seguintes instrumentos: questionário sobre hábitos de morder, características do sono e relato de bruxismo; a escala "The Circadian Energy Scale" (CIRENS), para mensurar o perfil cronotipo; e o dominio self da versão brasileira da Escala Multidimensional de Satisfação de Vida para Adolescentes (EMSVA). O PBS e PBV foram mensurados considerando o auto relato positivo, somado à presença de desgaste dentário por atrição aferido em exame clinico feito pela pesquisadora previamente calibrada. A análise descritiva foi incluida nos artigos 1 e 2. O artigo 1 usou a análise de caminhos, tecnica que descreve as dependências direcionadas entre um conjunto de variáveis. No artigo 2 foi feita regressão logistica condicional (OR) (p<0,05). Como resultados no artigo 1, verificou-se que 22,3% dos adolescentes apresentaram PBS e 51,1% PBV. As duas manifestações de bruxismo apresentaram associação entre si, com uma correlação moderada e positiva (ß= 0,390). Qualidade do sono e renda familiar tiveram um efeito direto sobre PBS (ß= - 0,138; ß=0,123; respectivamente) e em PBV (ß= - 0,155; ß=0,116; respectivamente), de modo que aqueles com maior renda e com má qualidade do sono tenderam a apresentar provável bruxismo tanto BS, quanto BV. Cronotipo teve efeito direto sobre o PBS, de modo que adolescentes com cronotipo matutino tenderam a ter o comportamento (ß= -0,102). Adolescentes que relataram babar no travesseiro enquanto dormiam (ß= 0,184) e/ou que tinham sono agitado (ß= 0,104) tenderam a apresentar PBS. Já no artgido 2 verificou-se que má qualidade do sono (OR=1,731, IC95% 1,054-2,842, p=0,030), hábito de morder objetos muitas vezes (OR=3,303, IC95% 1,631-6,690, p=0,001), hábito de morder ou apertar os lábios algumas vezes (OR=2,134, IC95% 1,230-3,702, p=0,007) e hábito de morder ou apertar os lábios muitas vezes nas duas semanas anteriores à avaliação (OR=2,355, IC95% 1,203- 4,608, p=0,012) foram associados à ocorrencia de PBV. Concluiu-se com o artigo 1 que o perfil cronotipo, renda familiar e caracteristicas do sono influenciaram no caminho percorrido pelo PBS, enquanto renda e qualidade do sono influenciam o PBV. Enquato atraves do artigo 2, concluiu- se que adolescentes com má qualidade do sono e que apresentam habitos de morder tiveram mais chance de apresentar PBV.

Bruxism is a behavior, with masticatory muscle activity, which can present itself as sleep bruxism (SB) and awake bruxism (AB). It has a multifactorial etiology, and is little explored among adolescents. This thesis is composed of two articles assessing prevalence, associated factors, and path analysis. The objective of article 1 (n=403) was to recognize the pathways influencing the occurrence of probable sleep bruxism (PSB) and probable awake bruxism (PAB) in adolescents. Paper 2 (n=342) aimed to evaluate the association between PSB and biting habits, life satisfaction, sleep characteristics and chronotype profile in adolescents by means of a case-control study. After approval by the institutional ethics committee, adolescents aged 12 to 19 years, regularly enrolled in public and private schools in Belo Horizonte, Brazil, participated in the study. Parents/caregivers answered a questionnaire about their children's sleep characteristics. The adolescents answered the following instruments: a questionnaire about biting habits, sleep characteristics and bruxism report; the Circadian Energy Scale (CIRENS), to measure the chronotype profile; and the self domain of the Brazilian version of the Multidimensional Life Satisfaction Scale for Adolescents (MLSSA). The PSB and PAB were measured considering the positive self-report, added to the presence of attrition dental wear measured in a clinical examination performed by a previously calibrated researcher. Descriptive analysis was included in articles 1 and 2. Article 1 used path analysis, a technique that describes the directed dependencies among a set of variables. In article 2, conditional logistic regression (OR) was performed (p<0.05). As results in article 1, it was found that 22.3% of the adolescents presented PSB and 51.1% PAB. The two manifestations of bruxism showed an association with each other, with a moderate and positive correlation (ß= 0.390). Sleep quality and family income had a direct effect on PSB (ß= - 0.138; ß=0.123; respectively) and on PAB (ß= -0.155; ß=0.116; respectively), so that those with higher income and poor sleep quality tended to show likely bruxism in both SB and AB. Chronotype had a direct effect on PSB, such that adolescents with morning chronotype tended to have the behavior (ß= -0.102). Adolescents who reported drooling on the pillow while sleeping (ß= 0.184) and/or who had restless sleep (ß= 0.104) tended to present PSB. In artgid 2, on the other hand, it was found that poor sleep quality (OR=1.731, 95%CI 1.054-2.842, p=0.030), habit of biting objects often (OR=3.303, 95%CI 1.631-6.690, p=0.001), habit of biting or tightening lips sometimes (OR=2, 134, 95%CI 1.230-3.702, p=0.007) and biting or lip-squeezing often in the two weeks prior to evaluation (OR=2.355, 95%CI 1.203- 4.608, p=0.012) were associated with the occurrence of PAB. It was concluded with article 1 that the chronotype profile, family income and sleep characteristics influence the path taken by PSB, while income and quality of sleep influence PAB. In article 2, it was concluded that adolescents with poor sleep quality and those with biting habits were more likely to present PAB.

Research progress in circadian rhythms in the application of psychological rehabilitation of cancer patients / 中南大学学报(医学版)

The psychological distress of cancer patients seriously affects their therapeutic effects. Effective psychological rehabilitation of cancer patients significantly improves their survival chance and quality of life. Circadian rhythm results from adaptation to the environment during the organism's evolution. When the endogenous clock system is disrupted or the external environment is changed, the body and the environment are out of synchronization, and the circadian rhythm will be disrupted. Circadian rhythm disorder is a common phenomenon in cancer patients, and the changes of circadian rhythm are closely related to their psychological distress. Many studies believe that the circadian rhythm disorder of cancer patients may directly or indirectly affect their psychology through various mechanisms, and targeted intervention by regulating the circadian rhythm of patients may be an essential means to promote the psychological rehabilitation.

Advances in circadian rhythms in oral maxillofacial tissues and oral-related diseases / 中华口腔医学杂志

Circadian rhythm is an internal autonomous timing mechanism formed by the body in response to changes of external environment. It participates in the regulations of various physiological activities, affecting the formation and outcome of various diseases in the human body. This paper summarizes the changes of local tissue rhythms in common disease states, such as oral and maxillofacial malformations, inflammation and malignant tumors. The importance of circadian clock system to the activities of oral and maxillofacial tissues are dialectically analyzed, mainly on the mechanisms of action in maintaining oral health and in affecting the processes of common oral diseases and oral-related systemic diseases. At the same time, chronological therapy and new strategies of prevention and treatment for oral-related diseases based on the changes in tissue rhythm are summarized and prospected to provide new ideas for maintaining oral and systemic health.

Study on homeostasis and circadian rhythm of attention performance of different chronotypes in sleep deprivation / 生物医学工程学杂志

Difference of chronotypes makes influence to cognitive performance of individuals in routine duties. In this paper, 55 subjects with different chronotypes were subjected to continuous sleep deprivation for 30 h by using the constant routine protocol, during which core body temperature was measured continuously, and subjective sleepiness self-rating and the performance of selective attention were measured hourly. The results showed that the phase difference of core body temperature has no significant difference, yet the amplitude and term difference among the three chronotypes are significant. There was an advance in phase between subjective sleepiness self-rating and core body temperature, and the self-rating sleepiness of evening type came the latest, and the self-rating sleepiness of morning type dissipated the fastest. The response time of selective attention showed a 2 h phase delay with subjective sleepiness self-rating. And the analysis of core body temperature showed that the later the chronotype was, the greater the phase delay was. The correct rate of selective attention of different chronotypes were inconsistent with delay of subjective sleepiness self-rating and core body temperature. We provide reference for industry, aviation, military, medical and other fields to make a more scientific scheduling/ shifting based on cognitive performance characteristics of different chronotypes.

Research progress on the application of time-restricted eating in adult obesity and related metabolic diseases / 中华预防医学杂志

The soaring prevalence of obesity and its complications presents a significant health care burden, and there is currently a lack of effective and sustainable treatment methods. Time-restricted eating (TRE) is a specific intermittent fasting (IF) protocol involving consistent fasting and eating periods within a 24-hour cycle. Time-restricted eating can restore robust circadian rhythms and improve metabolic health, providing an emerging dietary strategy for the prevention and treatment of obesity and related metabolic diseases. Previous TRE trials laid the groundwork, and indicate a need for further clinical research including large-scale controlled trials to determine TRE efficacy and the mechanisms by which it may affect humans.

Co-regulation of circadian clock genes and microRNAs in bone metabolism / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Mammalian bone is constantly metabolized from the embryonic stage, and the maintenance of bone health depends on the dynamic balance between bone resorption and bone formation, mediated by osteoclasts and osteoblasts. It is widely recognized that circadian clock genes can regulate bone metabolism. In recent years, the regulation of bone metabolism by non-coding RNAs has become a hotspot of research. MicroRNAs can participate in bone catabolism and anabolism by targeting key factors related to bone metabolism, including circadian clock genes. However, research in this field has been conducted only in recent years and the mechanisms involved are not yet well established. Recent studies have focused on how to target circadian clock genes to treat some diseases, such as autoimmune diseases, but few have focused on the co-regulation of circadian clock genes and microRNAs in bone metabolic diseases. Therefore, in this paper we review the progress of research on the co-regulation of bone metabolism by circadian clock genes and microRNAs, aiming to provide new ideas for the prevention and treatment of bone metabolic diseases such as osteoporosis.

Research progress of the regulation of cochlear sensitivity to noise by circadian rhythm / 生理学报

High level noise can damage cochlear hair cells, auditory nerve and synaptic connections between cochlear hair cells and auditory nerve, resulting in noise-induced hearing loss (NIHL). Recent studies have shown that animal cochleae have circadian rhythm, which makes them different in sensitivity to noise throughout the day. Cochlear circadian rhythm has a certain relationship with brain-derived neurotrophic factor and glucocorticoids, which affects the degree of hearing loss after exposure to noise. In this review, we summarize the research progress of the regulation of cochlear sensitivity to noise by circadian rhythm and prospect the future research direction.

Research progress on the regulation of mammalian energy metabolism by the circadian clock system and gut microbiota / 生理学报

The mammalian internal circadian clock system has been evolved to adapt to the diurnal changes in the internal and external environment of the organism to regulate diverse physiological functions, such as the sleep-wake cycle and feeding rhythm, thereby coordinating the rhythmic changes of energy demand and nutrition supply in each diurnal cycle. The circadian clock regulates glucose metabolism, lipid metabolism, and hormones secretion in diverse tissues and organs, including the liver, skeletal muscle, pancreas, heart, and vessels. As a special "organ" of the host, the gut microbiota, together with the intestinal microenvironment (tissues, cells, and metabolites) in a co-evolutionary process, constitutes a micro-ecosystem and plays an important role in the process of nutrient digestion and absorption in the intestine of the host. In recent years, accumulating evidence indicates that the compositions, quantities, colonization, and functional activities of the gut microbiota exhibit significant circadian variations, which are closely related to the changes of various physiological functions under the regulation of host circadian clock system. In addition, several studies have shown that the gut microbiota can produce many important metabolites such as the short-chain fatty acids through the degradation of indigestive dietary fibers. A portion of gut microbiota-derived metabolites can regulate the circadian clock system and metabolism of the host. This article mainly discusses the interaction between the host circadian clock system and the gut microbiota, and highlights its influence on energy metabolism of the host, providing a novel clues and thought for the prevention and treatment of metabolic diseases.

Daytime sleepiness in elementary school students: the role of sleep quality and chronotype

ABSTRACT OBJECTIVE To investigate the occurrence of daytime sleepiness and associated sleep factors in a sample of elementary school students who attended school in the afternoon schedule. METHODS Sleep data from 363 Brazilian public school students (12.78 ± 1.36 years, 206 girls) were obtained by applying questionnaires in classrooms. All subjects attended school in the afternoon schedule, with classes starting between 1:00 and 1:20 p.m. Daytime sleepiness was assessed by the pediatric daytime sleepiness scale; sleep quality, by the mini-sleep questionnaire; and sleep patterns and chronotypes, by the Munich chronotype questionnaire. Scores equal to or greater than 15 pediatric daytime sleepiness scale points were considered as excessive daytime sleepiness. The predictive power of sleep variables on daytime sleepiness was evaluated by a multiple linear regression. RESULTS The subjects in the sample had an average time in bed greater than nine hours both on school days and on weekends. Nevertheless, 52.1% had an average pediatric daytime sleepiness scale score equal to or greater than 15 points, indicative of excessive daytime sleepiness. As for their quality of sleep, 41.1% had a very altered sleep. We observed, by a multiple linear regression, that quality of sleep (β = 0.417), chronotype (β = 0.174), mid-sleep on school days (β = 0.138), and time in bed (β = - 0.091) were all significant in predicting daytime sleepiness. CONCLUSION This study showed the occurrence of excessive daytime sleepiness in non-sleep deprived students who attended school in the afternoon. The worst quality of sleep and eveningness had a greater predictive power on daytime sleepiness than time in bed. Therefore, we must consider other factors in addition to sleep duration when planning interventions for daytime sleepiness.

Perception and sensory acceptance of sweet taste by individuals that who work/study on different shifts / Percepção e aceitação sensorial do gosto doce por indivíduos que trabalham/estudam em diferentes turnos

ABSTRACT Objective This study aimed to evaluate the perception and sensory acceptance of sweet taste by individuals who work/study on different shifts. Methods Three groups of individuals were recruited: the Control group (individuals that study during the day and do not work at night), Group 1 (individuals that study in the evening) and Group 2 (individuals that work overnight). The individuals were submitted to a detection threshold test using sucrose solutions and a sensory acceptance test using a structured hedonic scale and a Just-About-Right scale for sweet taste in blancmange. Results The detection thresholds were significantly higher for Groups 1 and 2. Individuals of Group 2 had a preference by blancmanges when having high sucrose concentrations, as well as had an ideal concentration of 10.50% sucrose against 5.95% sucrose for the Control group. Conclusion Our study shows a relationship between changes in the circadian cycle and the sensory perception and acceptance of sweet taste. More studies need to be performed to understand such relationships and their repercussions better.

RESUMO Objetivo O objetivo deste estudo foi avaliar a percepção e a aceitação sensorial do gosto doce por indivíduos que trabalham/estudam em diferentes turnos. Métodos Foram recrutados três grupos de indivíduos: Grupo Controle (indivíduos que estudam durante o dia e não trabalham à noite), Grupo 1 (indivíduos que estudam à noite) e Grupo 2 (indivíduos que trabalham de madrugada). Os indivíduos foram submetidos ao teste de limiar de detecção utilizando soluções de sacarose e aos testes de aceitação sensorial utilizando escala hedônica estruturada e escala do ideal para o gosto doce em manjar branco. Resultados Os limiares de detecção foram significativamente maiores para os Grupos 1 e 2, sendo certo que os indivíduos do Grupo 2 tiveram preferência pelos manjares com altas concentrações de sacarose, assim como apresentaram uma concentração ideal de 10,50% de sacarose contra 5,95% de sacarose para o grupo Controle. Conclusão Este estudo mostra uma relação entre mudanças no ciclo circadiano e a percepção e a aceitação sensorial do gosto doce, mostrando que estudos mais aprofundados precisam ser realizados para entender melhor tais relações e suas repercussões.

At the crossroads of epilepsy and sleep: some issues / Na encruzilhada da epilepsia e do sono: algumas questões

There is a close association between sleep and epilepsy, and this literature review aims to raise issues regarding sleep time control, circadian and ultradian rhythms, epilepsy and its interaction with sleep and circadian rhythm, epilepsy and sleep disorders, and finally epilepsy management and medications. It is mentioned that sleep may provide a hypersynchronous state, as occurs in non-rapid eye movement sleep (NREM), and hyperexcitability, in cyclic alternating pattern (CAP), allowing more frequent interictal epileptiform abnormalities and seizures. In some epilepsy syndromes, seizures occur broadly / or entirely during sleep or on awakening, mainly in childhood, and maybe exacerbated in adults during the sleep or sleep-deprived, and there are the so-called Sleep-related epilepsies that are divided as sleep-associated, sleep-accentuated and arousal/awakening related. Sleep quality may be reduced in patients with epilepsy also due to nocturnal seizures or concomitant sleep disorders. Sleep disorders are common in patients with epilepsy and treatment of them mainly sleep-disordered breathing may improve seizure control. Besides, some parasomnias may mimic seizures, and also they can adversely affect the quality and quantity of sleep whereas antiepileptic therapy can have a negative or positive effect on sleep. Nocturnal epileptic seizures may be challenging to discern from parasomnias, in particular NREM parasomnias such as night terrors, sleepwalking and confusional arousals.

Há uma estreita associação entre sono e epilepsia, e esta revisão de literatura tem como objetivo levantar questões relacionadas ao controle do tempo do sono, ritmos circadianos e ultradianos, epilepsia e sua interação com sono e ritmo circadiano, epilepsia e transtornos do sono e, finalmente, o tratamento e medicamentos para epilepsia. Menciona-se que o sono pode proporcionar um estado hipersincrônico, como ocorre no sono "non-rapid eye movement" (NREM), e hiperexcitabilidade, no "cyclic alternating pattern" (CAP), permitindo anormalidades epileptiformes interictais e crises epilépticas mais frequentes. Em algumas síndromes epilépticas, as crises ocorrem ampla / ou inteiramente durante o sono ou despertar, principalmente na infância, e podem ser exacerbadas em adultos durante o sono ou privação de sono, e as chamadas epilepsias relacionadas ao sono se dividem em sono associadas, sono acentuadas e relacionadas com o despertar. A qualidade do sono pode ser reduzida em pacientes com epilepsia também devido a crises epilépticas noturnas ou transtornos do sono concomitantes. Esses são comuns em pacientes com epilepsia e o seu tratamento, principalmente dos transtornos respiratórios do sono, pode melhorar o controle das crises epilépticas. Além disso, algumas parassonias podem mimetizar crises epilépticas, e também elas podem afetar adversamente a qualidade e a quantidade do sono, enquanto a terapia antiepiléptica pode ter um efeito negativo ou positivo sobre o sono. Pode ser difícil discernir as crises epilépticas noturnas das parassonias, em particular das parassonias NREM, como terrores noturnos, crises de sonambulismo e despertares confusionais.