Kairos study protocol: a multidisciplinary approach to the study of school timing and its effects on health, well-being and students' performance.

Recent evidence from chronobiology, chssronomedicine and chronopsychology shows that the organisation of social time (e.g., school schedules) generally does not respect biological time. This raises concerns about the impact of the constant mismatch between students' social and internal body clocks on their health, well-being and academic performance. The present paper describes a protocol used to investigate the problem of (de) synchronisation of biological times (chronotypes) in childhood and youth in relation to school times. It studies the effects of student chronotype vs. school schedule matches/mismatches on health behaviours (e.g., how many hours students sleep, when they sleep, eat, do physical activity, spend time outdoors in daylight) and learning (verbal expression, spatial structuring, operations) and whether alert-fatigue levels mediate this effect alignments/misalignments on learning (verbal expression, spatial structuring, operations) and their mediation by alert-fatigue levels. The novelty of our protocol lies in its multidisciplinary and mixed methodology approach to a relevant and complex issue. It draws on up-to-date knowledge from the areas of biology, medicine, psychology, pedagogy and sociology. The methods employed include a varied repertoire of techniques from hormonal analysis (cortisol and melatonin), continuous activity and light monitoring, self-registration of food intake, sleep timings, exercise and exposure to screens, alongside with systematic application of cognitive performance tests (e.g., memory, reasoning, calculation, attention) and self-reported well-being. This comprehensive and interdisciplinary protocol should support evidence-based education policy measures related to school time organisation. Appropriate and healthier school timetables will contribute to social change, healthier students and with more efficient learning. The results of studies using a similar methodology in other countries would ensure replication and comparability of results and contribute to knowledge to support policy making.

Screen media use and sleep patterns in Spanish adolescents during the lockdown of the coronavirus pandemic.

PURPOSE: The aim of this study was to investigate screen media use and sleep patterns among Spanish adolescents during the lockdown (LD) of the first peak of the coronavirus pandemic. METHODS: Cross-sectional community-based study of adolescents aged 11-18 years. An online questionnaire with queries about screen time, sleep, and other healthy habits was completed by parents or guardians. RESULTS: Overall 265 adolescents were enrolled. The mean age was 13.6 ± 2.3 years, 58% were boys, 68% were in secondary school and 72% lived in urban areas. Before the LD (BLD) 87% of adolescents used electronic devices < 4 h/d, while during the LD (DLD) screen time was > 4 h/d in 75% of cases (p < 0.0001). A delayed wake time and bedtime weekdays (BLD wake time weekdays: later than 09:45 0.0% vs. DLD 30%, p < 0.0001, and BLD bedtime weekdays: later than 00:30 3% vs. DLD 35%, p < 0.0001) and weekends DLD was observed. Adolescents who used electronic devices > 4 h/d DLD compared with those who used < 4 h/d reported more frequently long sleep latency (93% vs. 7%, p = 0.007), low sunlight exposure (77% vs. 23%, p = 0.031), less physical activity (86%. vs. 15%, p = 0.011) and weight gain (78%. vs. 22%, p = 0.049). CONCLUSIONS: During the lockdown Spanish adolescents reported elevated screen time and delayed sleep patterns. An increase in screen media use was associated with unhealthy habits.

Melatonin Levels in Children with Obesity Are Associated with Metabolic Risk and Inflammatory Parameters.

Melatonin, the hormone of circadian rhythm regulation, is involved in the modulation of mitochondrial activity through its antioxidant and anti-inflammatory properties. Alteration of circadian rhythms such as sleep is related to obesity and metabolic pathogenesis in adulthood, but studies during childhood are scarce. The present study investigated the association of melatonin with metabolic and inflammatory markers in children with (n = 113) and without obesity (n = 117). Melatonin was measured in saliva four and two hours before bedtime, and after one hour of sleep. Cardiometabolic factors, high sensitivity C-reactive protein, immune markers (monocyte chemoattractant protein-1, plasminogen activator inhibitor-1, tumor necrosis α and interferon-γ), leptin and ghrelin were determined. Sleep duration was recorded by a questionnaire. The melatonin level at 1 h after sleep was found to be increased more than twofold in children with obesity (90.16 (57.16-129.16) pg/mL) compared to controls (29.82 (19.05-61.54) pg/mL, p < 0.001) and was related to fat mass (rho = 0.294, p < 0.001); melatonin levels at 1 h after sleep were inversely correlated with high-density lipoprotein cholesterol. Positive correlation was found with apolipoprotein B, adipokines, high sensitivity C-reactive protein, plasminogen activator inhibitor-1 and tumor necrosis factor-α. Shorter sleep duration and earlier waking times were recorded in children with obesity. In conclusion, melatonin in children with obesity appears to be involved in the global metabolic and inflammatory alteration of this condition.

Melatonin Content of Human Milk: The Effect of Mode of Delivery.

Objective: Cesarean section rates are increasing in developed countries and could be performed as an emergency or elective procedure. Our research aim was to determine whether elective cesarean section influences the melatonin content, the main circadian hormone, in human milk. Methods: Twenty-one women after vaginal delivery and 18 women after elective cesarean section were included. Only healthy mothers with normal newborns exclusively breastfed were recruited. Two samples of human milk were collected for each woman at three stages of lactation: colostrum, transitional milk, and mature milk; at each stage, one daytime sample and another nighttime sample were obtained. In total, 228 milk samples were studied. The melatonin content was analyzed by enzyme-linked immunosorbent assay. Results: Melatonin rhythmicity with higher melatonin content at night was maintained at each of the three stages of lactation, regardless of the type of delivery. A higher melatonin content was found in daytime colostrum after cesarean section with respect to colostrum obtained from mothers after vaginal delivery (30.3 pg/mL versus 14.7 pg/mL, p = 0.020). Melatonin content decreased progressively throughout the course of lactation in both groups. This decrease was significant when comparing transitional milk to colostrum in the cesarean group, both in the daytime (p = 0.016) and nighttime samples (p = 0.048). Conclusions: Cesarean section is associated with an increase in daytime colostrum melatonin. No difference was observed in mature milk with respect to vaginal delivery. Melatonin values in human milk decrease during the first month of lactation and circadian rhythmicity was observed irrespective of the mode of delivery.

El sueño del niño con trastornos del neurodesarrollo / The sleep in children with neurodevelopmental disorders

El sueño adecuado es necesario para el desarrollo sináptico y la maduración cerebral, un sueño de mala calidad tiene efectos perjudiciales en las funciones cognitivas, de atención, memoria y conducta de los niños. La preocupación sobre la alta prevalencia de los problemas del sueño es amplia en todo el mundo; las consecuencias de estos problemas son incluso más importantes en los niños portadores de trastornos del neurodesarrollo; estos niños a menudo tienen dificultades de inicio y mantenimiento del sueño y despertares nocturnos frecuentes que afectan a sus problemas de conducta. El propósito de este escrito es revisar el estado del arte de los problemas del sueño en los niños con trastornos del neurodesarrollo. En este punto, es importante tener en cuenta el ritmo circadiano, un reloj que genéticamente dirige los ritmos celulares de transcripción, traslación y metabolismos. Este reloj se combina con el ambiente diurno y nocturno coordinando estos mecanismos durante los ciclos luz/oscuridad, sueño/vigilia, frío/calor, ingesta/ayuno, tanto diariamente como en las diferentes estaciones. En conclusión, los problemas del sueño son un factor condicionante de la evolución y calidad de vida de los niños con trastornos del neurodesarrollo, que debe ser tenido en cuenta en todos los casos y ocupar un lugar preferente tanto en la etapa diagnóstica como en la terapéutica.

Adequate sleep is of critical need for a typical synaptic development and brain maturation, a poor quality sleep can have detrimental effects on children's' cognitive attention, memory, mood regulation, and behavior functions. Great concern has been voiced out regarding the high prevalence of poor sleep in children worldwide, the effects of poor sleep may be even more pronounced in children with neurodevelopmental disorders; these children often have difficulties with falling and staying asleep and with night awakenings, this has a strong association with daytime behavior problems. The purpose of this article is to provide an overview of the state of the science of sleep in children with a neurodevelopmental disorder. In this context, it is important to take the circadian cycle into account, a genetically encoded clock that drives cellular rhythms of transcription, translation and metabolism. The circadian clock interacts with the diurnal and nocturnal environment that also drives transcription and metabolism during light/dark, sleep/wake, hot/cold and feast/fast daily and seasonal cycles In conclusion, the sleep problems are a conditioning factor in the evolution and quality of life of children with neurodevelopmental disorders that must be taken into account in all cases and occupy a preferential place in both the diagnostic and the therapeutic stages.

[The sleep in children with neurodevelopmental disorders]. / El sueño del niño con trastornos del neurodesarrollo.

Adequate sleep is of critical need for a typical synaptic development and brain maturation, a poor quality sleep can have detrimental effects on children's' cognitive attention, memory, mood regulation, and behavior functions. Great concern has been voiced out regarding the high prevalence of poor sleep in children worldwide, the effects of poor sleep may be even more pronounced in children with neurodevelopmental disorders; these children often have difficulties with falling and staying asleep and with night awakenings, this has a strong association with daytime behavior problems. The purpose of this article is to provide an overview of the state of the science of sleep in children with a neurodevelopmental disorder. In this context, it is important to take the circadian cycle into account, a genetically encoded clock that drives cellular rhythms of transcription, translation and metabolism. The circadian clock interacts with the diurnal and nocturnal environment that also drives transcription and metabolism during light/dark, sleep/wake, hot/cold and feast/fast daily and seasonal cycles In conclusion, the sleep problems are a conditioning factor in the evolution and quality of life of children with neurodevelopmental disorders that must be taken into account in all cases and occupy a preferential place in both the diagnostic and the therapeutic stages.

El sueño adecuado es necesario para el desarrollo sináptico y la maduración cerebral, un sueño de mala calidad tiene efectos perjudiciales en las funciones cognitivas, de atención, memoria y conducta de los niños. La preocupación sobre la alta prevalencia de los problemas del sueño es amplia en todo el mundo; las consecuencias de estos problemas son incluso más importantes en los niños portadores de trastornos del neurodesarrollo; estos niños a menudo tienen dificultades de inicio y mantenimiento del sueño y despertares nocturnos frecuentes que afectan a sus problemas de conducta. El propósito de este escrito es revisar el estado del arte de los problemas del sueño en los niños con trastornos del neurodesarrollo. En este punto, es importante tener en cuenta el ritmo circadiano, un reloj que genéticamente dirige los ritmos celulares de transcripción, traslación y metabolismos. Este reloj se combina con el ambiente diurno y nocturno coordinando estos mecanismos durante los ciclos luz/oscuridad, sueño/vigilia, frío/calor, ingesta/ayuno, tanto diariamente como en las diferentes estaciones. En conclusión, los problemas del sueño son un factor condicionante de la evolución y calidad de vida de los niños con trastornos del neurodesarrollo, que debe ser tenido en cuenta en todos los casos y ocupar un lugar preferente tanto en la etapa diagnóstica como en la terapéutica.

The connection of circadian rhythm to inflammatory bowel disease.

Inflammatory bowel disease (IBD) comprises a group of chronic, immune system-mediated inflammatory diseases that primarily affect the gastrointestinal tract. The pathogenesis of the intestinal lesions in IBD remains elusive, but the inflammation process could be the result of dysfunction of the innate and adaptive immune systems induced by genetic and environmental factors. In recent years, research has demonstrated a connection between environmental stressors that can influence day-night variations, also called circadian rhythms, and digestive health. In this review, we focus on alterations in the complex interactions between intestinal mucosa, microbial factors, and the immune response in the intestinal milieu. We introduce the mechanisms that establish circadian rhythms and their regulation by the circadian rhythm genes. Evidence of circadian variation in the defense mechanisms of the intestine and its implication in the maintenance of a healthy microbiota are presented. Disruption of the circadian system can increase the activity of the gut immune system and the release of inflammatory factors. The link between chronodisruption or circadian rhythm impairment and IBD demonstrated by experimental and clinical studies illustrates the potential impact of circadian rhythms on treatment of these diseases. Future studies that investigate aspects of this subject are warranted.

Insomnio en niños y adolescentes. Documento de consenso / Insomnia in children and adolescents. A consensus document

El insomnio es una patología muy frecuente en edad pediátrica (30% en niños menores de 5 años) que ocasiona una grave repercusión cognitiva, emocional y en el aprendizaje junto con una importante comorbilidad médica y afectación de la calidad de vida del niño y la familia. La formación de los pediatras en el diagnóstico y el tratamiento del mismo suele ser deficitaria. Por todo ello, se presenta el documento de consenso sobre el manejo del insomnio en la infancia y la adolescencia elaborado por representantes de la Asociación Española de Pediatría, la Sociedad Española de Sueño, la Sociedad Española de Pediatría Extrahospitalaria y de Atención Primaria, la Sociedad Española de Medicina de la Adolescencia, la Sociedad Española de Psiquiatría Infantil y la Sociedad Española de Neurología Pediátrica. Este grupo recomienda que el diagnóstico debe ser clínico y solo en los casos dudosos o en que sea necesario un diagnóstico diferencial serán necesarias pruebas complementarias. Asimismo el tratamiento se debe basar principalmente en terapias cognitivo-conductuales y en una modificación de los hábitos de sueño. El uso de medicamentos y sustancias para facilitar el sueño es elevado, aunque no existen guías clínicas que lo apoyen

Insomnia is very common during childhood (30% of children under 5), and causes a serious cognitive and emotional consequence in learning, as well as significant medical comorbidity. It also affects the quality of life, not only of the child, but also of the whole family. Paediatrician training in its diagnosis and treatment is usually poor. For this reason a consensus document is presented on the management of insomnia in children and adolescents. This has been developed by members of the Spanish Paediatrics Association, the Spanish Sleep Society, the Spanish Society of Paediatric Outpatient and Primary Care, the Spanish Adolescent Medicine Society, the Spanish Child and Adolescent Society, and the Spanish Paediatric Neurology Society. The group suggests that diagnosis must be clinical and complementary tests will only be required in doubtful cases or when a differential diagnosis is needed. Likewise, treatment should be mainly based on cognitive-behavioural therapy and the modification of sleeping habits. Using medicines and other substances to make the sleep easier is currently quite common, even although there are no clinical guidelines to support this

[Insomnia in children and adolescents. A consensus document]. / Insomnio en niños y adolescentes. Documento de consenso.

Insomnia is very common during childhood (30% of children under 5), and causes a serious cognitive and emotional consequence in learning, as well as significant medical comorbidity. It also affects the quality of life, not only of the child, but also of the whole family. Paediatrician training in its diagnosis and treatment is usually poor. For this reason a consensus document is presented on the management of insomnia in children and adolescents. This has been developed by members of the Spanish Paediatrics Association, the Spanish Sleep Society, the Spanish Society of Paediatric Outpatient and Primary Care, the Spanish Adolescent Medicine Society, the Spanish Child and Adolescent Society, and the Spanish Paediatric Neurology Society. The group suggests that diagnosis must be clinical and complementary tests will only be required in doubtful cases or when a differential diagnosis is needed. Likewise, treatment should be mainly based on cognitive-behavioural therapy and the modification of sleeping habits. Using medicines and other substances to make the sleep easier is currently quite common, even although there are no clinical guidelines to support this.

Short Sleep Duration Is Related to Emerging Cardiovascular Risk Factors in Obese Children.

OBJECTIVE: The aim of the present study was to evaluate the influence of sleep duration on cardiovascular risk factors in obese children. METHODS: Cross-sectional analysis of 90 obese children ages 7 to 16 years. Anthropometric and clinical evaluation with specification of dietary and lifestyle habits was carried out during an office visit. Sleep duration was evaluated by the BEARS (B = bedtime issues, E = excessive daytime sleepiness, A = night awakening, R = regularity and duration of sleep, S = snoring) questionnaire on children's sleep characteristics. Sleep time adequacy by age was assessed according to the criteria of the National Sleep Foundation. Biochemical blood variables indicative of metabolic risk (glucose, lipid profile, and insulin) were obtained. Emergent new factors of metabolic risk, including high-sensitive C-reactive protein, γ-glutamyltranspeptidase, homocysteine, retinol-binding protein 4 (RBP4), thyroid-stimulating hormone (TSH), inflammatory markers, and the adipokines leptin, adiponectin, and ghrelin were also evaluated. The relations between the duration of sleep and these variables were analyzed by general lineal model analysis. Significant variables were introduced in logistic regression analysis to determine the odds ratio (OR) and 95% confidence interval (CI) of cardiometabolic factors with respect to sleep. RESULTS: Children who slept for short duration were significantly more at risk of severe central obesity. In the regression model, the mean arterial pressure (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.02-1.17, P = 0.008), homocysteine (OR 1.41, 95% CI 1.08-1.84, P = 0.013), RBP4 (OR 1.78, 95% CI 1.15-2.78, P = 0.010), and TSH (OR 2.01, 95% CI 1.21-3.34, P = 0.007) remain as significant independent predictors related to short sleep duration. We did not find any association between sleep duration and inflammatory markers or adipokines. CONCLUSIONS: Short sleep duration increases the severity of obesity and is related to cardiovascular risk factors in children.

Novedades en el Consenso Español. Visión desde la Pediatría en Atención Primaria / No disponible

Durante las últimas décadas, el Síndrome de Apneas/Hipopneas durante el Sueño (SAHS) en los niños, ha sido ampliamente reconocido como un trastorno frecuente, con importantes implicaciones clínicas y se ha convertido en un problema de Salud de primera magnitud. El SAHS en los niños, es el máximo exponente de los Trastornos Respiratorios del Sueño (TRS) y se asocia con importante morbilidad cardiovascular, endocrinometabólica y neurocognitiva, existiendo actualmente evidencias de lesión de órganos diana y daño celular. En el Documento de Consenso se realiza una revisión de la literatura en relación con la comorbilidad asociada al SAHS (AU)

No disponible

Documento de consenso del síndrome de apneas-hipopneas durante el sueño en niños (versión completa) / Consensus document on sleep apnea-hypopnea syndrome in children (full version)

No disponible

Epidemiología. Factores de riesgo y factores genéticos / Epidemiology. Risk factors and genetic influence

Los estudios epidemiológicos de los trastornos respiratorios del sueño (TRS) con una amplia base poblacional son escasos. A pesar de ello, los datos disponibles en la actualidad cifran la presencia de ronquido habitual en el 7,45 % (intervalo de confianza del 95 %, 5,75–9,61) de la población infantil. El 10 % de los roncadores habituales presentará en su evolución síndrome de apnea-hipopnea del sueño, si bien en los niños con comorbilidad añadida (obesidad, asma, etc.) o clínica de apnea del sueño la asociación ronquido habitual-apnea se incrementa de manera notable. La prevalencia de apnea del sueño según la observación de padres o tutores de episodios de apnea es del 0,2–4 %. Cuando el diagnóstico se realiza mediante cuestionarios directos a los padres su prevalencia se incrementa al 4–11 %. Si se realiza por medios objetivos de laboratorio de sueño su prevalencia oscila entre el 1 y el 4 %. Actualmente, la obesidad es un factor importante de riesgo. En obesos, la prevalencia de TRS oscila entre el 4,69 y el 6,6 %, por lo que su cribado en los pacientes obesos con o sin clínica sugestiva debería ser rutinario. La genética juega un importante papel y, aunque su cometido está todavía por dilucidar, el 35–40 % de la varianza de los TRS es atribuible a factores genéticos. Su estudio abre una importante puerta que modificará en un futuro el enfoque médico de los TRS (AU)

Epidemiological studies of sleep-disordered breathing in broad population samples are scarce. Nevertheless, currently available data indicate that habitual snoring is present in 7.45 % (95 % CI: 5.75–9.61) of the child population. Approximately 10 % of habitual snorers develop sleep apnea. However, in children with associated comorbidity (obesity, asthma…) or clinical symptoms of sleep-disordered breathing, the association between snoring and sleep apnea is significantly increased. The prevalence of sleep apnea according to parents’ or guardians’ observation of apnea episodes is 0.2–4 %. When the diagnosis is based on questionnaires administered directly to parents, the prevalence increases to 4–11 %. If diagnosis is made by objective means, the prevalence ranges from 1–4 %. Obesity is currently a major risk factor. In obese children, the prevalence of sleep apnea oscillates between 4.69 % and 6.6 % and consequently screening of sleep-disordered breathing in obese patients with or without suggestive symptoms should be routine. Genetic factors strongly influence sleep-disordered breathing and seem to account for 35–40 % of the variance in this disorder, although their precise role has yet to be clarified. Genetic study opens up an important gateway in the future medical approach to sleep-disordered breathing (AU)

[Epidemiology. Risk factors and genetic influence]. / Epidemiología. Factores de riesgo y factores genéticos.

Epidemiological studies of sleep-disordered breathing in broad population samples are scarce. Nevertheless, currently available data indicate that habitual snoring is present in 7.45 % (95 % CI: 5.75-9.61) of the child population. Approximately 10 % of habitual snorers develop sleep apnea. However, in children with associated comorbidity (obesity, asthma…) or clinical symptoms of sleep-disordered breathing, the association between snoring and sleep apnea is significantly increased. The prevalence of sleep apnea according to parents' or guardians' observation of apnea episodes is 0.2-4 %. When the diagnosis is based on questionnaires administered directly to parents, the prevalence increases to 4-11 %. If diagnosis is made by objective means, the prevalence ranges from 1-4 %. Obesity is currently a major risk factor. In obese children, the prevalence of sleep apnea oscillates between 4.69 % and 6.6 % and consequently screening of sleep-disordered breathing in obese patients with or without suggestive symptoms should be routine. Genetic factors strongly influence sleep-disordered breathing and seem to account for 35-40 % of the variance in this disorder, although their precise role has yet to be clarified. Genetic study opens up an important gateway in the future medical approach to sleep-disordered breathing.

Síndrome de Prader-Labhart-Willi y apnea durante el sueño: apropósito de 3 pacientes / Prader-Labhart-Willi syndrome and apnea during sleep: apropos of 3 patients

El síndrome de Prader-Labhart-Willi (SPW) es una entidad que se asocia a trastornos respiratorios durante el sueño, lo que puede tener consecuencias fatales para la vida. Se presentan 3 pacientes con diagnóstico de SPW: 2 del sexo masculino y 1 del femenino. El diagnóstico en todos ellos fue confirmado después de los 2 años de edad. Los hallazgos clínicos más relevantes fueron: talla y peso corporal normal al nacimiento así como hipotonía muscular. En 2 pacientes la obesidad se inició después de los 2 años de edad y en el otro a los 18 meses de nacidos. La acromicria y retraso mental moderado estuvo presente en los 3 pacientes. Los resultados de los cariotipos por técnica de bandas fueron 46XY para los del sexo masculino y 46XX para la del femenino. Los 2 pacientes del sexo masculino presentaron episodios de apnea durante el sueño (Sleep Apnea Syndrome), lo que ocasionó el fallecimiento de ambos por paro respiratorio antes de los 12 años de edad. Se recomienda la vigilancia estrecha de estos pacientes, principalmente durante las infecciones respiratorias y las crisis de asma bronquial(AU)

Síndrome de Prader-Labhart-Willi y apnea durante el sueño: apropósito de 3 pacientes / Prader-Labhart-Willi syndrome and apnea during sleep: apropos of 3 patients

El síndrome de Prader-Labhart-Willi (SPW) es una entidad que se asocia a trastornos respiratorios durante el sueño, lo que puede tener consecuencias fatales para la vida. Se presentan 3 pacientes con diagnóstico de SPW: 2 del sexo masculino y 1 del femenino. El diagnóstico en todos ellos fue confirmado después de los 2 años de edad. Los hallazgos clínicos más relevantes fueron: talla y peso corporal normal al nacimiento así como hipotonía muscular. En 2 pacientes la obesidad se inició después de los 2 años de edad y en el otro a los 18 meses de nacidos. La acromicria y retraso mental moderado estuvo presente en los 3 pacientes. Los resultados de los cariotipos por técnica de bandas fueron 46XY para los del sexo masculino y 46XX para la del femenino. Los 2 pacientes del sexo masculino presentaron episodios de apnea durante el sueño (Sleep Apnea Syndrome), lo que ocasionó el fallecimiento de ambos por paro respiratorio antes de los 12 años de edad. Se recomienda la vigilancia estrecha de estos pacientes, principalmente durante las infecciones respiratorias y las crisis de asma bronquial(AU)