Self-Reported Sleep Duration Is a Useful Tool to Predict Sarcopenia in Chilean Older Adults: Evidence from the ALEXANDROS Longitudinal Study.

Age-related sleep disorders share common pathways with sarcopenia. Prospective data from Latin American populations are scarce, and the association between sleep disorders and sarcopenia in Chileans remains unknown. Thus, we aimed to study the longitudinal association between sleep disorders and sarcopenia in a cohort study of 1116 community-dwelling Chilean older people ≥60 years old from the ALEXANDROS cohorts. After the exclusion criteria, 318 subjects were followed. Sociodemographic data, self-reported chronic diseases, sedentarism, sleep characteristics, anthropometric measurements, handgrip strength, and muscle performance were assessed. Results indicated that at baseline, the prevalence of sarcopenia was 24.10% without gender differences, and the prevalence of self-reported sleep problems was 23.3%, higher in women (26.46% versus 17.15% in men). The adjusted Cox regression models for sarcopenia showed an association between sarcopenia, sleep disorders (HR = 2.08, 95% IC 1.14-3.80), and long sleep duration (HR = 2.42, 95% IC 1.20-4.91). After 8.24 years of follow-up, there were 2.2 cases of sarcopenia per 100 person-years. This study demonstrates that sleep disorders are an independent risk factor for sarcopenia in Chilean older people. The identification of sleep disorders through self-reported data provides an opportunity for early identification of risk and cost-effective sarcopenia prevention.

Investigating the psychological and physiological responses to isolation and confinement using the THOR space analog simulation / Investigando las respuestas psicológicas y fisiológicas al aislamiento y confinamiento utilizando la simulación análoga espacial THOR

This research investigates astronaut performance under simulated space conditions, using THOR, an analog astronaut training protocol, during a week-long confinement in an Analog Astronaut Training Center in Poland. Materials and Five participants, including four military and one civilian, underwent a week of isolation. Tests were conducted to assess heart rate variability ­HRV­, psychological health, and sleep patterns. Data collection and analysis were standardized, with an alpha level of p < 0.05 and power of 80%. The study found reductions in fat percentage and weight, while muscle mass and water content remained stable. HRV showed significant changes. Increased sleep and state anxiety levels were noted, along with decreased cognitive abilities. Personality traits exhibited heightened hostility and social anxiety, culminating in psychological discomfort. HRV values were normal with variations likely due to stress. A significant correlation was found between mental performance and HRV, indicating potential influence of sleep on cognitive function during isolation. The study highlights the need for more research on the psycho-logical and physiological implications of long-duration space missions and similar high-demand environments.

Esta investigación examina el rendimiento de los astronautas análogos bajo condiciones espaciales simuladas durante una semana de confina-miento en un Centro de Entrenamiento de Astronautas Análogos en Polonia. Cinco participantes, incluyendo cuatro militares y un civil, fueron sometidos a una semana de aislamiento. Se realizaron pruebas para evaluar la variabilidad de la frecuencia cardíaca ­HRV­, la salud psicológica y los patrones de sueño. La recolección y análisis de datos fueron estandarizados, con un nivel alfa de p < 0.05 y una potencia del 80%. El estudio encontró reducciones en el porcentaje de grasa y peso, mientras que la masa muscular y el contenido de agua permanecieron estables. La HRV mostró cambios significativos. Se observaron niveles elevados de sueño y ansiedad estado, junto con disminuciones en las habilidades cognitivas. Los rasgos de personalidad mostraron una hostilidad y ansiedad social aumentada, culminando en incomodidad psicológica. Los valores de HRV fueron normales con variaciones probablemente debidas al estrés. Se encontró una correlación significativa entre el rendimiento mental y la HRV, indicando la posible influencia del sueño en la función cognitiva durante el aislamiento. El estudio resalta la necesidad de más investigaciones sobre las implicaciones psicológicas y fisiológicas de las misiones espaciales de larga duración y entornos similares de alta demanda.

A Longitudinal Study of the Effects of Bed-Sharing Experience in Infancy on Sleep Outcomes at 2 Years Old.

OBJECTIVE: To assess the effects of bed-sharing experiences in infancy on sleep patterns and sleep problems at 2 years of age. STUDY DESIGN: A total of 1564 children from an ongoing Shanghai Maternal-Child Pairs Cohort were included. Bed-sharing experiences were collected when children were 2, 6, and 24 months old via caregiver-completed questionnaires (whether caregivers shared a bed with children during the night), and children's bed-sharing experiences were classified as follows: no bed-sharing, early-only bed-sharing, late-onset bed-sharing, and persistent bed-sharing. Sleep outcomes at month 24 were assessed using the Brief Infant Sleep Questionnaire. Sleep patterns and problems were compared among the 4 types of bed-sharing experiences. RESULTS: Of the 1564 infants, 10.10% had no bed-sharing, 18.35% had early-only, 27.94% had late-onset, and 43.61% had persistent bed-sharing. Compared with children with no bed-sharing, children with late-onset and persistent bed-sharing had shorter nighttime sleep durations and longer daytime sleep durations (P < .05) and were more likely to snore (aOR 1.87 [95% CI 1.25-2.79]; aOR 1.68 [95% CI 1.14-2.47]) and have sleep onset difficulty (aOR 2.06 [95% CI 1.37-3.09]; aOR 2.07 [95% CI 1.41-3.05]). However, caregivers of infants in the late-onset and persistent bed-sharing groups perceived less problematic sleep (aOR 0.38 [95% CI 0.26-0.56] and aOR 0.40 [95% CI 0.28-0.58]). CONCLUSIONS: Bed-sharing is a common experience among Chinese children. Although bed-sharing may reduce caregivers' perception of children's problematic sleep, late-onset or persistent bed-sharing in infancy is associated with sleep problems at 2 years of age.

Longitudinal changes in sleep patterns and circadian rhythm metrics in preschool-age children from Northern Mexico.

OBJECTIVES: To assess changes in sleep parameters and circadian rhythm metrics measured by actigraphy in preschool-aged children. DESIGN: Longitudinal analysis over 1 year. PARTICIPANTS: Ninety-four children living in Tijuana and Ensenada, Mexico. MEASUREMENTS: Children wore accelerometers on the right hip for one continuous week at baseline and 1-year follow-up. Parents recorded child bedtime, waketime, and naps in sleep diaries. We used cosinor and nonparametric approaches to calculate circadian rhythm metrics. RESULTS: At baseline, children had a mean age of 4.2 years, and 51.1% were girls. In multivariable models adjusted for age, gender, BMI category, parental education, household income and city, at follow-up children had significantly earlier waketimes (ß = -7.99 minutes, p < .001) compared to baseline. Children also had lower sleep onset latency (ß = -2.32 minutes, p = .057), and longer nighttime sleep (ß = 9.38 minutes, p = .079), but these changes were not significant at the α < 0.05 level. We found significant increases in log relative amplitude (ß = 0.017, p = .009), and decreases in log midline estimated statistic of rhythm (ß = -0.084, p = .017) and log of the least active 5-hour period (ß = -0.057, p = .010). When we adjusted for co-sleeping, we found significant decreases in the number of nighttime awakenings (ß = -1.29, p = .011) but otherwise similar results. There were no other changes in sleep parameters or circadian rhythm metrics. CONCLUSIONS: Mean increases in nighttime sleep and earlier wake times over one year were concomitant with decreases in overall activity levels and increases in circadian rhythm robustness. Co-sleeping was a predictor of sleep disturbances. This study provides longitudinal evidence regarding changes in sleep and circadian metrics in a sample of children from an under-researched sociodemographic group during an important, early life period.

The effect of sleep quality on academic performance is mediated by Internet use time: DADOS study / O efeito da qualidade do sono no desempenho acadêmico é mediado pelo tempo de uso da internet: estudo DADOS

Abstract Objective: The aims of the present study were to analyze the association of sleep patterns with academic and cognitive performance in adolescents, and to test the potential mediating effect of different activities of screen media usage on this association. Methods: A sample of 269 adolescents (140 boys) aged 14 years from the baseline data of the Deporte, ADOlescencia y Salud study completed questionnaires about sleep quality, cognitive performance, and leisure-time sedentary behaviors. Sleep duration was objectively computed using a wrist-worn GENEActiv accelerometer and academic performance was analyzed through school records. Results: Sleep quality (but not sleep duration) was associated with all the academic performance indicators (all p < 0.05). Analysis of covariance revealed higher grades among adolescents with better sleep quality (PSQI ≤ 5; all p < 0.05). These analyses showed no differences regarding cognitive performance. Internet use time was revealed as a mediator of the association between sleep quality and academic performance, being significant for all academic performance indicators (PM ranging from 15.5% to 16.0%). Conclusions: The association between sleep quality and academic performance in adolescents is mediated by time of Internet use. Overall, reducing Internet use in adolescents could be an achievable intervention for improving sleep quality, with potentially positive effects on academic performance.

Resumo Objetivo: Analisar a associação dos padrões de sono com o desempenho acadêmico e cognitivo em adolescentes e testar o efeito mediador potencial de diferentes atividades com uso de dispositivos (mídias) com tela nessa associação. Métodos: Uma amostra de 269 adolescentes (140 meninos) de 14 anos, da linha de base do estudo DADOS (Deporte, ADOlescencia y Salud) preencheu uma série de questionários sobre qualidade do sono, desempenho cognitivo e comportamentos sedentários no lazer. A duração do sono foi calculada objetivamente com um acelerômetro de pulso GENEActiv e o desempenho acadêmico foi analisado por meio de registros escolares. Resultados: A qualidade do sono (mas não a duração do sono) foi associada a todos os indicadores de desempenho acadêmico (todos os valores de p < 0,05). A análise de covariância revelou notas mais altas nos adolescentes com melhor qualidade de sono (PSQI ≤ 5; todos os valores de p < 0,05). Essas análises não mostraram diferenças em relação ao desempenho cognitivo. O tempo de uso da Internet revelou-se como um mediador da associação entre qualidade do sono e desempenho acadêmico, foi significativo para todos os indicadores de desempenho acadêmico (PM variou de 15,5% a 16,0%). Conclusões: A associação entre qualidade do sono e desempenho acadêmico em adolescentes é mediada pelo tempo de uso da internet. No geral, reduzir o tempo de uso da internet pelos adolescentes pode ser uma intervenção viável para melhorar a qualidade do sono, com efeitos potencialmente positivos no desempenho acadêmico.

Identification of earlier predictors of pregnancy complications through wearable technologies in a Brazilian multicentre cohort: Maternal Actigraphy Exploratory Study I (MAES-I) study protocol.

INTRODUCTION: Non-invasive tools capable of identifying predictors of maternal complications would be a step forward for improving maternal and perinatal health. There is an association between modification in physical activity (PA) and sleep-wake patterns and the occurrence of inflammatory, metabolic, pathological conditions related to chronic diseases. The actigraphy device is validated to estimate PA and sleep-wake patterns among pregnant women. In order to extend the window of opportunity to prevent, diagnose and treat specific maternal conditions, would it be possible to use actigraphy data to identify risk factors for the development of adverse maternal outcomes during pregnancy? METHODS AND ANALYSIS: A cohort will be held in five centres from the Brazilian Network for Studies on Reproductive and Perinatal Health. Maternal Actigraphy Exploratory Study I (MAES-I) will enrol 400 low-risk nulliparous women who will wear the actigraphy device on their wrists day and night (24 hours/day) uninterruptedly from 19 to 21 weeks until childbirth. Changes in PA and sleep-wake patterns will be analysed throughout pregnancy, considering ranges in gestational age in women with and without maternal complications such as pre-eclampsia, preterm birth (spontaneous or provider-initiated), gestational diabetes, maternal haemorrhage during pregnancy, in addition to perinatal outcomes. The plan is to design a predictive model using actigraphy data for screening pregnant women at risk of developing specific adverse maternal and perinatal outcomes. ETHICS AND DISSEMINATION: MAES-I has been reviewed and approved by each institutional review board and also by the National Council for Ethics in Research. Detailed information about the study is provided in the Brazilian Cohort website (www.medscinet.com/samba) and findings will be published in the scientific literature and institutional webpages.

The effect of sleep quality on academic performance is mediated by Internet use time: DADOS study.

OBJECTIVE: The aims of the present study were to analyze the association of sleep patterns with academic and cognitive performance in adolescents, and to test the potential mediating effect of different activities of screen media usage on this association. METHODS: A sample of 269 adolescents (140 boys) aged 14 years from the baseline data of the Deporte, ADOlescencia y Salud study completed questionnaires about sleep quality, cognitive performance, and leisure-time sedentary behaviors. Sleep duration was objectively computed using a wrist-worn GENEActiv accelerometer and academic performance was analyzed through school records. RESULTS: Sleep quality (but not sleep duration) was associated with all the academic performance indicators (all p<0.05). Analysis of covariance revealed higher grades among adolescents with better sleep quality (PSQI≤5; all p<0.05). These analyses showed no differences regarding cognitive performance. Internet use time was revealed as a mediator of the association between sleep quality and academic performance, being significant for all academic performance indicators (PM ranging from 15.5% to 16.0%). CONCLUSIONS: The association between sleep quality and academic performance in adolescents is mediated by time of Internet use. Overall, reducing Internet use in adolescents could be an achievable intervention for improving sleep quality, with potentially positive effects on academic performance.

Transtornos alimentares e padrão circadiano alimentar: uma revisão / Eating disorders and circadian eating pattern: a review

Este artigo tem como objetivo revisar aspectos relacionados a transtornos alimentares e suas relações com as alterações no ritmo circadiano. Realizou-se uma busca sistematizada das informações nas bases de dados PubMed usando os seguintes descritores: eating disorders, circadian rhythm, night eating syndrome, binge eating disorder e sleep patterns. Os transtornos alimentares, como a síndrome do comer noturno e o transtorno da compulsão alimentar periódica, têm sido considerados e relacionados a um atraso no ritmo circadiano da ingestão alimentar e saciedade prejudicada. Os ritmos circadianos são aqueles que apresentam um período de 24 h, como, por exemplo, o ciclo sono-vigília, temperatura corporal, atividade e comportamento alimentar. Distúrbios provocados pelas alterações nos horários de sono/vigília influenciam o apetite, a saciedade e, consequentemente, a ingestão alimentar, o que parece favorecer o aumento desses transtornos. Percebe-se que o comportamento alimentar pode ser influenciado por ritmos circadianos. Porém, mais estudos e o maior conhecimento sobre a ritmicidade alimentar podem contribuir com o melhor entendimento do comportamento alimentar atual, atuando na prevenção e/ou tratamento de transtornos alimentares.

This review aims at reviewing aspects related to eating disorders arising from changes in circadian rhythm. There was a systematic search in PubMed databases, using the following descriptors: eating disorders, circadian rhythm, night eating syndrome, binge eating disorder, and sleep patterns. Eating disorders, such as night eating syndrome and binge eating disorder, have been considered and related to a delay in circadian rhythm in food intake and impaired satiety. Circadian rhythms are those that show a period of 24 h, for example, sleep-wake cycle, body temperature, activity and eating behavior. Disorders related to changes in sleep-wake schedules influence the appetite, satiety and consequently food intake, which seems to increase such disorders. Circadian rhythm can influence eating behavior. However, more studies and knowledge about food rhythmicity might contribute to better understanding the current eating behavior, acting in prevention and/or treatment of eating disorders.