Research Protocol for Sleep in Families With a Preterm Infant.

BACKGROUND: Specificities regarding the quality and quantity of sleep of preterm infants and their parents following discharge of the preterm infant from the hospital are not well known. Given this lack of knowledge, the links between the sleep characteristics of these parents, family functioning, and their psychological well-being are also unclear. OBJECTIVES: The purpose of this article is to summarize the research protocol of a cross-sectional, mixed-methods, convergent design study, which aims to evaluate the sleep patterns of preterm infants and both their parents and document the associations between sleep quality, parents' psychological well-being, and family functioning during the posthospitalization period. METHODS: A convenience sample is used to recruit 30 families. For quantitative data collection, a questionnaire booklet consisting of validated questionnaires is used to measure sleep quality of each family member, parental psychological well-being, and family functioning completed by each parent. An actigraph and a sleep diary measure sleep quantity of each parent and the preterm infant. Afterward, semistructured interviews are carried out with each parent to explore their perceptions and needs concerning their infant's and their own sleep quality. For data analysis, qualitative and quantitative data are analyzed separately and then merged to allow for an integrative interpretation of the results. RESULTS: The research project is ongoing; 25 of 30 families have completed the data collection. Data analysis is underway. DISCUSSION: This research will provide a global portrait of the families' sleep 1 month after the preterm infant is discharged from the hospital, which is not well known to date. The results will help healthcare providers involved with preterm infants and their families after discharge from the hospital to increase their comprehension of the families' reality and adapt their interventions to meet these needs.

Sleeping through a Lockdown: How Adolescents and Young Adults Struggle with Lifestyle and Sleep Habits Upheaval during a Pandemic.

OBJECTIVES: The objective of the present study was to investigate the relationship between chronotype, lifestyle habits during the pandemic, and changes in sleep timing during the first wave of the COVID-19 pandemic in youth. METHOD: An online survey of adolescents and young adults (N = 449) was conducted in June 2020. Multivariate hierarchical regressions assessed the contribution of chronotype and changes in lifestyle habits to sleep timing during the COVID-19 pandemic in two age groups (12 to 17 years old and 18 to 25 years old). RESULTS: Chronotype was a significant predictor of changes in sleep habits during the pandemic in both age groups. In adolescents, electronic device usage during the pandemic was a significant predictor of bedtimes and wake times on weekdays, and caffeine during the pandemic was a predictor of weekday wake times. The number of hours worked during the pandemic was a significant predictor of weekday wake times in both age groups. In young adults, cannabis consumption during the pandemic was a predictor of weekend bedtimes. A later chronotype, along with higher usage of electronic devices, fewer hours worked, as well as higher caffeine and cannabis consumption during the pandemic were associated with delayed sleep timing during the pandemic in youth. CONCLUSION: These results highlight the importance of assessing lifestyle habits when exploring changes in sleep habits in youth.

Interindividual differences in energy intake after sleep restriction: The role of personality and implicit attitudes toward food.

Sleep restriction (SR) often leads to an increase in energy intake (EI). However, large variability in EI after SR is often observed, which suggests that individual characteristics may affect food intake. The objective of this study was to explore the influence of characteristics generally associated with risk-taking (sensitivity to reward and personality traits: impulsiveness, sensation seeking) and implicit attitudes toward food on EI after sleep loss. 17 subjects completed the NEO-PI-3, an Implicit Association Test measuring implicit attitudes towards healthy and unhealthy foods, and the Sensitivity to Punishment and Sensitivity to Reward Questionnaire. 24h Ad libitum EI was assessed following a habitual sleep night, a 50% SR with an advanced wake time, and a 50% SR with a delayed bedtime. Changes in EI between each SR condition and the control condition (ΔEI) were calculated for each subject. Despite no changes in overall EI between sleep conditions, results showed large interindividual variations (-669 to +899 kcal) across SR conditions. Regression modeling showed that a lower sensation seeking and higher favorable implicit attitudes towards unhealthy food were significantly associated with increased ΔEI in the advanced wake time condition. For the delayed bedtime, lower sensation seeking was associated with increased ΔEI while controlling for age, sex, REM sleep, and implicit attitudes. These results suggest that certain personality traits and implicit attitudes toward food are associated with changes in EI after sleep loss.

Greater circadian disadvantage during evening games for the National Basketball Association (NBA), National Hockey League (NHL) and National Football League (NFL) teams travelling westward.

We investigated the effects of a circadian disadvantage (i.e. playing in a different time zone) on the winning percentages in three major sport leagues in North America: the National Basketball Association, the National Hockey League and the National Football League. We reviewed 5 years of regular season games in the National Basketball Association, National Hockey League and National Football League, and noted the winning percentage of the visiting team depending on the direction of travel (west, east, and same time zone) and game time (day and evening games). T-tests and analysis of variance were performed to evaluate the effects of the circadian disadvantage, its direction, the number of time zones travelled, and the game time on winning percentages in each major league. The results showed an association between the winning percentages and the number of time zones traveled for the away evening games, with a clear disadvantage for the teams travelling westward. There was a significant difference in the teams' winning percentages depending on the travelling direction in the National Basketball Association (F2,5908  = 16.12, P < 0.0001) and the National Hockey League (F2,5639  = 4.48, P = 0.011), and a trend was found in the National Football League (F2,1279  = 2.86, P = 0.058). The effect of the circadian disadvantage transcends the type of sport and needs to be addressed for greater equity among the western and eastern teams in professional sports. These results also highlight the importance of circadian rhythms in sport performance and athletic competitions.

The effects of partial sleep restriction and altered sleep timing on appetite and food reward.

We examined the effects of partial sleep restriction (PSR) with an advanced wake-time or delayed bedtime on measures of appetite, food reward and subsequent energy intake (EI). Twelve men and 6 women (age: 23 ± 4 years, body fat: 18.8 ± 10.1%) participated in 3 randomized crossover sessions: control (habitual bed- and wake-time), 50% PSR with an advanced wake-time and 50% PSR with a delayed bedtime. Outcome variables included sleep architecture (polysomnography), ad libitum EI (validated food menu), appetite sensations (visual analogue scales), satiety quotient (SQ; mm/100 kcal) and food reward (Leeds Food Preference Questionnaire and the relative-reinforcing value (RRV) of preferred food task). Increased fasting and post-standard breakfast appetite ratings were noted following PSR with an advanced wake-time compared to the control and PSR with a delayed bedtime sessions (Fasting hunger ratings: 77 ± 16 vs. 65 ± 18 and 64 ± 16; P = 0.01; Post-meal hunger AUC: 5982 ± 1781 vs. 4508 ± 2136 and 5198 ± 2201; P = 0.03). Increased explicit wanting and liking for high- relative to low-fat foods were also noted during the advanced wake-time vs. control session (Explicit wanting: -3.5 ± 12.5 vs. -9.3 ± 8.9, P = 0.01; Explicit liking: -1.6 ± 8.5 vs. -7.8 ± 9.6, P = 0.002). No differences in the RRV of preferred food, SQ and ad libitum lunch intake were noted between sessions. These findings suggest that appetite sensations and food reward are increased following PSR with an advanced wake-time, rather than delayed bedtime, vs. CONTROL: However, this did not translate into increased EI during a test meal. Given the increasing prevalence of shift workers and incidences of sleep disorders, additional studies are needed to evaluate the prolonged effects of voluntary sleep restriction with altered sleep timing on appetite and EI measurements.

Validation of sleep-2-Peak: A smartphone application that can detect fatigue-related changes in reaction times during sleep deprivation.

Despite its high sensitivity and validity in the context of sleep loss, the Psychomotor Vigilance Test (PVT) could be improved. The aim of the present study was to validate a new smartphone PVT-type application called sleep-2-Peak (s2P) by determining its ability to assess fatigue-related changes in alertness in a context of extended wakefulness. Short 3-min versions of s2P and of the classic PVT were administered at every even hour during a 35-h total sleep deprivation protocol. In addition, subjective measures of sleepiness were collected. The outcomes on these tests were then compared using Pearson product-moment correlations, t tests, and repeated measures within-groups analyses of variance. The results showed that both tests significantly correlated on all outcome variables, that both significantly distinguished between the alert and sleepy states in the same individual, and that both varied similarly through the sleep deprivation protocol as sleep loss accumulated. All outcome variables on both tests also correlated significantly with the subjective measures of sleepiness. These results suggest that a 3-min version of s2P is a valid tool for differentiating alert from sleepy states and is as sensitive as the PVT for tracking fatigue-related changes during extended wakefulness and sleep loss. Unlike the PVT, s2P does not provide feedback to subjects on each trial. We discuss how this feature of s2P raises the possibility that the performance results measured by s2P could be less impacted by motivational confounds, giving this tool added value in particular clinical and/or research settings.

The relationship between sleep, perfectionistic strivings, perfectionistic concerns, and academic and sports performance in young athletes.

Perfectionism is associated with sleep as well as with academic and sports performance. Given the importance of sleep for performance and the sleep changes that occur during adolescence, the present study aimed to explore the relationship between sleep, two dimensions of perfectionism (perfectionistic strivings and perfectionistic concerns), with academic and sports performance in young athletes. The occurrence of perfectionistic strivings was identified as a tendency to set high personal standards for oneself, while the occurrence of perfectionistic concerns was identified as a tendency to feel pressure to be perfect and have concerns about imperfections. A total of 32 athletes aged 13 to 16 years old participated in this study. Perfectionism, sleep, and course grades were measured at the end of the school year. Sleep was measured by actigraphy, and sports performance improvement was obtained by comparing individual performance at the beginning and the end of the school year. The moderating effect of both dimensions of perfectionism on the relationships between sleep and academic and sports performance improvement was measured. First, results showed no significant relationship between sleep and academic/sports performance. Further analyses revealed that perfectionistic strivings moderated the relationship between certain aspects of sleep with academic and sports performance improvement. Delayed and suboptimal sleep habits were associated with lower academic and sports performance improvement when low levels of perfectionistic strivings were present. Results with perfectionistic concerns showed that this dimension did not moderate the relationship between sleep and academic and sports performance improvement. This study supports the notion that high levels of perfectionistic strivings in young athletes may mitigate the adverse effects of poor sleep habits in young athletes.

Gender differences in the interference of sleep difficulties and daytime sleepiness on school and social activities in adolescents.

OBJECTIVES: During adolescence, changes in the circadian and homeostatic systems, combined with psychosocial factors, create a phase delay in the sleep of adolescents. These changes in sleep are associated with increased sleep difficulties and a shortened sleep duration, which has a negative impact on daytime functioning of adolescents. Some studies showed that teenage girls report worse sleep quality and shorter sleep duration than boys during adolescence. The objective of this study was to investigate gender differences in the impact of sleep difficulties and sleepiness on daytime functioning in adolescents and to measure which aspect of sleep may interfere with daytime functioning in boys and girls. METHOD: A total of 731 adolescents (311 boys, 420 girls; age 13 to 17,5 years) completed questionnaires on sleep and daytime functioning. RESULTS: Compared to boys, teenage girls reported a significantly greater impact of short sleep duration and sleep difficulties on their school and social activities. Furthermore, our results suggest that the factors predicting the negative interference on daytime functioning seem to be more complex and multifactorial for girls than for boys. CONCLUSIONS: This study further emphasizes the importance of monitoring insufficient and poor sleep quality in adolescents, as these sleep variables seem to have a significant impact on their daytime functioning. Clinicians should also take into account gender when considering sleep issues in adolescents, as teenage girls and boys have different vulnerabilities and needs.

COVID-19 and sleep patterns in adolescents and young adults.

OBJECTIVE: In March 2020, the world experienced a global pandemic, which involved the shutdown of schools or a transposition to remote teaching in most countries. The objective of the present study was to investigate the impact of the COVID-19 pandemic related lockdown on sleep patterns and sleep quality in adolescents and young adults. METHODS: An online survey was conducted in June 2020 with adolescents and young adults (n = 498) aged 12-25 years. Participants had to answer questions on sleep, first retrospectively, referring to the time prior to the pandemic, and then referring to the time during the pandemic. RESULTS: A pronounced shift towards later sleep combined with an increase in sleep duration was found during the pandemic. However, these changes in sleep habits were more pronounced in adolescents than in young adults and seem to occur mostly during weekdays compared to weekends. During the pandemic, teens also reported an improvement in daytime sleepiness and subjective sleep quality, while young adults reported an increase in sleep difficulties associated with sleep onset difficulties, nocturnal and early morning awakenings, and nightmares. CONCLUSIONS: The COVID-19 related lockdown seems to have had a beneficial effect on sleep in adolescents. In young adults, benefits are not as obvious. These results support that later school start times would be beneficial for adolescents. However, in young adults it could be important to investigate the effects of other situational or interindividual factors (stress, lifestyle habits, employment, etc.).

The association between REM sleep and decision-making: Supporting evidences.

Studies suggest that REM sleep is important for the maintenance of prefrontal cortex functioning. Therefore, reducing REM sleep may have an impact on cognitive functions such as impulse control and decision-making processes. This study examined the association between impulsiveness and sensation seeking personality traits, REM sleep and performance on a decision-making computer task following a habitual night of sleep and a partial sleep deprivation (PSD) condition with advanced wake-up time. Eighteen young adults participated in two experimental conditions: a control (habitual bedtime and wake time) and a 50% PSD with an advanced wake time. Impulsiveness and sensation seeking personality traits were measured with a personality inventory (NEO-PI-3), sleep was assessed using standard polysomnography and the Iowa Gambling Task (IGT) was completed at noon following each sleep condition. Results showed that when sleep deprived, participants choose more often to play riskier decks of cards during the last half of the IGT. Results also showed that REM sleep duration and REM sleep deprivation were associated with riskier decisions on the IGT. Moreover, impulsiveness was associated with riskier decisions after a normal night of sleep. These findings suggest that REM sleep duration and impulsiveness are important factors to consider while investigating decision-making processes under conditions of uncertainty and risk.

Attention and non-REM sleep in neuroleptic-naive persons with schizophrenia and control participants.

The relationship between sleep architecture and attentional performance was evaluated in neuroleptic-naive patients with schizophrenia and healthy controls. Participants were recorded in a sleep laboratory for two consecutive nights after which selective and sustained attention performance was tested. In both groups of participants, Spearman's rho statistics revealed a negative correlation between reaction time on the selective attention task and sleep spindle density. Only control participants showed a negative correlation between reaction time and duration of stage 2 sleep and a positive correlation between reaction time and duration of stage 1 ("light") sleep. Only persons with schizophrenia showed a negative correlation between reaction time and duration of stage 4 ("deep") sleep. In the sustained attention task, we found no correlation between reaction time and sleep for control participants while persons with schizophrenia showed a negative correlation between reaction time and duration of stage 4 sleep. It is proposed that EEG sleep spindle activity is associated with automatic attentional processing, while stage 2 sleep continuity in healthy individuals and percentage of stage 4 in patients with schizophrenia are associated with voluntary processes. These results support the existence of a relationship between non-rapid-eye-movement sleep and cognitive performance in healthy individuals as well as in persons with schizophrenia.

The effects of sleep restriction and altered sleep timing on energy intake and energy expenditure.

Experimental evidence suggests that sleep restriction increases energy intake (EI) and may alter energy expenditure (EE). However, it is unknown whether the timing of a sleep restriction period impacts EI and EE the following day. Hence, we examined the effects of sleep restriction with an advanced wake-time or delayed bedtime on next day EI and EE. Twelve men and 6 women (age: 23±4years, body fat: 18.8±10.1%) participated in 3 randomized crossover sessions: control (habitual bed- and wake-times), 50% sleep restriction with an advanced wake-time and 50% sleep restriction with a delayed bedtime. Outcome variables included sleep architecture (polysomnography), EI (food menu), total EE and activity times (accelerometry). Carbohydrate intake was greater on day 2 in the delayed bedtime vs. control session (1386±513 vs. 1579±571kcal; P=0.03). Relative moderate-intensity physical activity (PA) time was greater in the delayed bedtime session vs. control and advanced wake-time sessions on day 1 (26.6±19.9 vs. 16.1±10.6 and 17.5±11.8%; P=0.01), whereas vigorous-intensity PA time was greater following advanced wake-time vs. delayed bedtime on day 1 (2.7±3.0 vs. 1.3±2.4%; P=0.004). Greater stage 1 sleep (ß=110kcal, 95% CI for ß=42 to 177kcal; P=0.004), and a trend for lower REM sleep (ß=-20kcal, 95% CI for ß=-41 to 2kcal; P=0.07), durations were associated with greater EI between sleep restriction sessions. These findings suggest that the timing of a sleep restriction period impacts energy balance parameters. Additional studies are needed to corroborate these findings, given the increasing prevalence of shift workers and incidences of sleep disorders and voluntary sleep restriction.

Sleep architecture and its clinical correlates in first episode and neuroleptic-naive patients with schizophrenia.

The goal of the present study was to characterize sleep organization in first episode and neuroleptic-naive patients with schizophrenia and to evaluate relationships between those sleep parameters and clinical symptoms. Eleven patients with acute schizophrenia never treated with neuroleptics were compared to 11 healthy controls. Sleep stages and phasic events (sleep spindles and rapid-eye-movements during REM sleep (REMs) were visually identified. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). Compared to controls, patients with schizophrenia had difficulty initiating sleep, decreased stage 4 duration, reduced rapid eye movement (REM) sleep latency, and normal sleep spindles and REMs densities. Positive symptoms correlated negatively with REM sleep latency. The BPRS total score correlated negatively with REM sleep duration and REMs density. The present results indicate that first episode and neuroleptic-naive patients with schizophrenia have difficulties initiating, but not maintaining, sleep. These results also confirm that the duration of stage 4 and REM sleep latency are reduced in first episode and neuroleptic-naive patients with schizophrenia. The fact that measures of REM sleep correlate with clinical scales of schizophrenia suggests that REM sleep physiology shares common substrates with symptoms of this disease.

Evening and morning EEG differences between young men and women adults.

Evening and morning waking EEG (eyes closed) was recorded in 16 women and 13 men aged 18-26 years old. Participants were fitted with a 13-electrode montage (Fp1, Fp2, FZ, F7, F8, C3, C4, T3, T4, P3, P4, O1, and O2) referred to linked ears. For each recording electrode, EEG total spectral amplitude power (microV/Hz, 0.75-19.75 Hz) was compared using 2 (Gender) x 2 (Moments) analyses of variance for repeated measures and LSD post-hoc tests. We found significant simple Gender effects, with women displaying higher EEG values for Central, Frontal, Parietal, and left Temporal leads. Simple Moment effects were also found, with lower morning values in Temporal and left Frontal recording sites. A Gender x Moment interaction was found at the right Frontal recording site. No significant effects were found for Prefrontal and Occipital recording sites, whatsoever. These results bring new understandings of gender and time of day effects in waking EEG and point to different sensitivity in different cortical areas. The present results could explain some of the observations related to gender differences in cognitive performance.