Sleep Schedule Regularity Is Associated with Sleep Duration in Older Australian Adults: Implications for Improving the Sleep Health and Wellbeing of Our Aging Population.

OBJECTIVES: The National Sleep Foundation (NSF) recommends 7 to 9 hours of sleep per night for adults ≥ 65 years of age. Sleep duration below 7h per night has been associated with negative health consequences, so enabling older adults to obtain at least 7 hours per night is important for health and wellbeing. However, little is known about behavioral factors that support sleep duration (≥ 7h/24h) in this group. Our aim was to determine factors associated with sleep duration in older adults, and evaluate the utility of sleep schedule regularity in particular, given the relationship between lifestyle regularity (of which sleep is an important component) and health in this population. METHODS: A sample of 311 Australian adults (≥ 65 years old; 156 male, 155 female) completed a telephone survey assessing sleep history over the prior 24 hours, sleep schedule regularity, demographic and health factors as part of a larger study of the Australian population. RESULTS: Sleep schedules with variability in bed and rise times of > 60 minutes were associated with increased odds of reporting sleep duration below 7 hours per night (< 7h/24h; OR = 2.38, CI = 1.26-4.48, p = .007). No other behaviors were associated with meeting sleep duration recommendations. CONCLUSIONS: Sleep schedule regularity may be associated with sleep duration (≥ 7h/24h) in older adults. CLINICAL IMPLICATIONS: Empowering older adults to maintain sleep schedule regularity may be a practical and efficacious strategy to support sleep durations that are in line with recommendations (≥ 7h/24h).

Impact of Mandatory Wake Time on Sleep Timing, Sleep Quality and Rest-Activity Cycle in College and University Students Complaining of a Delayed Sleep Schedule: An Actigraphy Study.

BACKGROUND: Individuals complaining of a delayed sleep schedule are expected to have shorter sleep duration and lower sleep quality when they must comply with morning obligations. The changes in the sleep schedule imposed by morning obligations may in turn decrease the stability and amplitude of their rest-activity cycle. These expectations were only partially supported in previous studies, possibly due to poor differentiation between days with mandatory or free wake times. PARTICIPANTS: Fourteen college/university students (8 women) with a complaint of a late sleep schedule and a bedtime after midnight were compared to fourteen controls with an earlier sleep schedule and no complaint. METHODS: During a week of 24-h activity recording, participants specified in their sleep diary whether their wake time was free or determined by an obligation. RESULTS: The number of nights with mandatory wake times was similar in the two groups. Groups were also similar for sleep duration and sleep quality over the 7 days of recording. Actigraphic sleep efficiency was the same in the two groups for both free and mandatory wake times, but subjective sleep quality decreased on the nights with mandatory wake time in both groups. On the nights with mandatory wake time, delayed participants had shorter sleep episodes and less total sleep time than controls. Rest-activity cycle amplitude was lower in the delayed group whether wake time was free or mandatory. CONCLUSION: Sleep duration and total sleep time differed between the two groups only when wake time was mandatory. Prior to mandatory wake times, delayed participants kept the same bedtime and shortened their sleep; sleep latency and sleep efficiency were preserved but subjective sleep quality and alertness on awakening decreased compared to nights with free wake time. Lower amplitude of the rest-activity cycle in delayed subjects may reflect lifestyle differences compared to control participants.

Delayed Sleep in Winter Related to Natural Daylight Exposure among Arctic Day Workers.

Natural daylight exposures in arctic regions vary substantially across seasons. Negative consequences have been observed in self-reports of sleep and daytime functions during the winter but have rarely been studied in detail. The focus of the present study set out to investigate sleep seasonality among indoor workers using objective and subjective measures. Sleep seasonality among daytime office workers (n = 32) in Kiruna (Sweden, 67.86° N, 20.23° E) was studied by comparing the same group of workers in a winter and summer week, including work and days off at the weekend, using actigraphs (motion loggers) and subjective ratings of alertness and mood. Actigraph analyses showed delayed sleep onset of 39 min in winter compared to the corresponding summer week (p < 0.0001) and shorter weekly sleep duration by 12 min (p = 0.0154). A delay of mid-sleep was present in winter at workdays (25 min, p < 0.0001) and more strongly delayed during days off (46 min, p < 0.0001). Sleepiness levels were higher in winter compared to summer (p < 0.05). Increased morning light exposure was associated with earlier mid-sleep (p < 0.001), while increased evening light exposure was associated with delay (p < 0.01). This study confirms earlier work that suggests that lack of natural daylight delays the sleep/wake cycle in a group of indoor workers, despite having access to electric lighting. Photic stimuli resulted in a general advanced sleep/wake rhythm during summer and increased alertness levels.

An actigraphic study of the sleep patterns of younger and older school-age children.

OBJECTIVE: Sleep is viewed as being relatively consistent across the school-age period (6-13 years of age), however this claim has not been empirically supported. The objective of this study was to document the duration, schedule, variability, and week versus weekend discrepancies of sleep in three distinct age groups within the school-age period. METHODS: Participants were divided by age: Cycle 1, 6 and 7 years; Cycle 2, 8 and 9 years; and Cycle 3, 10 and 11 years. For seven consecutive nights, sleep was assessed in the home environment using an actigraph. RESULTS: Compared to children of Cycle 1, those of Cycles 2 and 3 showed increasing and significant delays in sleep start time, increasingly shorter assumed and actual sleep durations, and larger night-to-night variability of sleep. Of the children in Cycles 1, 2, and 3, 96%, 87.7%, and 51.3%, respectively, were found to spend the recommended 9-11 h in bed. However, the actigraphic 'true sleep' measure revealed that only 17%, 7%, and 2.5% of these children, respectively, obtained the recommended amount of sleep. CONCLUSION: Sleep duration, schedule, and variability change significantly across the school-age period.

Daily Profiles of Light Exposure and Evening Use of Light-emitting Devices in Young Adults Complaining of a Delayed Sleep Schedule.

A number of factors can contribute to a delayed sleep schedule. An important factor could be a daily profile of light exposure favoring a later circadian phase. This study aimed to compare light exposure between 14 young adults complaining of a delayed sleep schedule and 14 matched controls and to identify possible associations between habitual light exposure and circadian phase. Exposure to white and blue light was recorded with ambulatory monitors for 7 consecutive days. Participants also noted their daily use of light-emitting devices before bedtime. Endogenous circadian phase was estimated with the dim light melatonin onset (DLMO) in the laboratory. The amplitude of the light-dark cycle to which the subjects were exposed was smaller in delayed than in control subjects, and smaller amplitude was associated with a later DLMO. Smaller amplitude was due to both decreased exposure in the daytime and increased exposure at night. Total exposure to blue light, but not to white light, was lower in delayed subjects, possibly due to lower exposure to blue-rich outdoor light. Lower daily exposure to blue light was associated with a later DLMO. Timing of relative increases and decreases of light exposure in relation to endogenous circadian phase was also compared between the 2 groups. In delayed subjects, there was a relatively higher exposure to white and blue light 2 h after DLMO, a circadian time with maximal phase-delaying effect. Delayed participants also had higher exposure to light 8 to 10 h after DLMO, which occurred mostly during their sleep episode but may have some phase-advancing effects. Self-reported use of light-emitting devices before bedtime was higher in delayed than in control subjects and was associated with a later DLMO. This study suggests that individuals complaining of a delayed sleep schedule engage in light-related behaviors favoring a later circadian phase and a later bedtime.

Initial consultation, analysis of complaint, causal investigation of insomnia / Consultation initiale, analyse de la plainte, enquête causale devant une insomnie

Initial consultation, analysis of complaint, causal investigation of insomnia Insomnia requires an initial clinical check-up with a full examination that explores both the complaint of sleep (difficulties in falling sleep, awakening in the night, early awakening) and the repercussion on the day. Lifestyle and behaviors are assessed (meals, sporting activity, type of activity before and at bedtime, regularity of schedules, working hours). Comorbidities are evaluated : depression, anxiety, restless legs syndrome, sleep apnea, somatic diseases, medication. Simple tools are used to complete this assessment : questionnaire of sleep assessment and its disorders, sleep schedule, possibly actimetry.

Consultation initiale, analyse de la plainte, enquête causale devant une insomnie L'insomnie nécessite un bilan initial clinique avec un interrogatoire complet qui explore à la fois la plainte concernant le sommeil (difficultés d'endormissement, réveils dans la nuit, réveil précoce) et son retentissement sur la journée. Le mode de vie et les comportements du patient sont évalués (repas, activité sportive, type d'activité avant et au moment du coucher, régularité des horaires, horaires de travail). Les comorbidités sont recherchées : dépression, anxiété, syndrome des jambes sans repos, apnées du sommeil, maladies somatiques, prise de médicaments. Des outils simples sont utilisés pour compléter ce bilan : questionnaire d'évaluation du sommeil et de ses troubles, agenda du sommeil, éventuellement actimétrie.

2B-Alert Web: An Open-Access Tool for Predicting the Effects of Sleep/Wake Schedules and Caffeine Consumption on Neurobehavioral Performance.

STUDY OBJECTIVES: Computational tools that predict the effects of daily sleep/wake amounts on neurobehavioral performance are critical components of fatigue management systems, allowing for the identification of periods during which individuals are at increased risk for performance errors. However, none of the existing computational tools is publicly available, and the commercially available tools do not account for the beneficial effects of caffeine on performance, limiting their practical utility. Here, we introduce 2B-Alert Web, an open-access tool for predicting neurobehavioral performance, which accounts for the effects of sleep/wake schedules, time of day, and caffeine consumption, while incorporating the latest scientific findings in sleep restriction, sleep extension, and recovery sleep. METHODS: We combined our validated Unified Model of Performance and our validated caffeine model to form a single, integrated modeling framework instantiated as a Web-enabled tool. 2B-Alert Web allows users to input daily sleep/wake schedules and caffeine consumption (dosage and time) to obtain group-average predictions of neurobehavioral performance based on psychomotor vigilance tasks. 2B-Alert Web is accessible at: https://2b-alert-web.bhsai.org. RESULTS: The 2B-Alert Web tool allows users to obtain predictions for mean response time, mean reciprocal response time, and number of lapses. The graphing tool allows for simultaneous display of up to seven different sleep/wake and caffeine schedules. The schedules and corresponding predicted outputs can be saved as a Microsoft Excel file; the corresponding plots can be saved as an image file. The schedules and predictions are erased when the user logs off, thereby maintaining privacy and confidentiality. CONCLUSIONS: The publicly accessible 2B-Alert Web tool is available for operators, schedulers, and neurobehavioral scientists as well as the general public to determine the impact of any given sleep/wake schedule, caffeine consumption, and time of day on performance of a group of individuals. This evidence-based tool can be used as a decision aid to design effective work schedules, guide the design of future sleep restriction and caffeine studies, and increase public awareness of the effects of sleep amounts, time of day, and caffeine on alertness.

Short sleep duration as a risk factor for childhood overweight/obesity: a large multicentric epidemiologic study in China.

OBJECTIVES AND SETTING: The present study was designed to examine the association of sleep duration with obesity/overweight in a multicentric urban sample of Chinese children. PARTICIPANTS AND DESIGN: A random sample of 17,696 children aged 7.00-11.99 years participated in a cross-sectional multicentric survey. MEASUREMENTS: The Chinese version of the Children's Sleep Habits Questionnaire was used to collect information on children's sleep behaviors. Body mass index (BMI) was calculated as weight (kilograms)/height squared (square meters). Sex, age, and BMI were used to define overweight and obesity based on the definition recommended by the Working Group on Obesity in China. RESULTS: The prevalence of obesity and overweight in Chinese school-aged children was 10.7% and 10.3%, respectively. Hierarchical multiple linear regression models revealed a significant association between shorter sleep duration (hours/day) and increased BMI (ß = -0.120; P = .019). Multivariate logistic regression models demonstrated that, compared with sleep duration ≥10 hours/d, mean sleep duration <9 hours/d experienced increased likelihood of overweight/obesity (odds ratio = 1.21; P = .005). Moreover, sleep-schedule variability, independent of sleep duration, was found to be associated with overweight/obesity (odds ratio = 1.11; P = .016). CONCLUSIONS: Sleep duration and sleep-schedule variability, along with television viewing, homework schedule, and snack eating, were linked to overweight/obesity among elementary school children in this population-based sample.