Self‐reported sleep quantity,quality and sleep hygiene in elite athletes

Sleep is essential for recovery and performance in elite athletes. While actigraphy‐based studies revealed suboptimal sleep in athletes, information on their subjective experience of sleep is scarce. Relatively unexplored is also the extent to which athletes’ sleep is adversely affected by environmental conditions and daytime behaviours, that is sleep hygiene. This study aimed to provide insight in sleep quantity, quality and its putative association with sleep hygiene. Participants were 98 elite (youth) athletes competing at the highest (inter‐)national level. Sleep quantity, quality and sleep hygiene were assessed once covering a 1‐month period by using established (sub)clinical questionnaires, and repeatedly during 7 consecutive days. Sleep quality was generally healthy, although 41% of all athletes could be classified as ‘poor sleeper’, and 12% were identified as having a sleep disorder. Daily self‐monitoring revealed sleep durations of 8:11 ± 0:45 h, but elevated wake after sleep onset of 13 ± 19 min. Sleep quality, feeling refreshed, and morning vigor were moderate at best. Regarding sleep hygiene, general measures revealed irregular sleep–wake patterns, psychological strain and activating pre‐sleep behaviours. At the daily level, blue‐light exposure and late‐evening consumption of heavy meals were frequently reported. General sleep hygiene revealed significant associations with sleep quality (0.45 < r > 0.50; P < 0.001). Results indicate that there is ample room for optimization, specifically in onset latency and in wake after sleep onset. Subtle improvements in sleep seem possible, and optimizing sleep hygiene, such as regular sleep–wake patterns and reducing psychological strain, may facilitate this sleep upgrading process.     

When sleep is perceived as wakefulness: an experimental study on state perception during physiological sleep

While electrophysiologically measured sleep and perception of sleep generally concur, various studies have shown this is not always the case. The objective of the present study was to assess the perception of actual state during sleep by the technique of planned awakenings and interviewing subjects on the preawakening state. Sixty-eight (43 females, 25 males) young (mean age: 24.1, SD 5.1 years) normal sleeping subjects were deliberately awakened out of consolidated sleep, either stage 2 (S2), or REM sleep, during the first night in a non-clinical sleep laboratory. While the preawakening state was experienced as sleep in 48 cases (70.6%), it was experienced as wakefulness in 20 cases (29.4%). The percentage of awake judgements was somewhat, but not significantly, higher for awakenings out of S2 (38.2%), to REM sleep (20.6%). The proportion of mismatches between electrophysiologically defined sleep and state judgements was time-dependent with more awake judgements for REM sleep in the second half of the sleep period (41.7%) than in the first one (17.4%). Those subjects who made an awake judgement more frequently had a feeling of being aware of the situation and their surroundings than those who made a sleep judgement (80% versus 33%). Awareness during sleep may be a cognitive style, which favours mismatches between state perception and electrophysiologically defined sleep. Sleep periods with concordant or discordant state judgements did not differ in electrophysiologically defined sleep onset latency, sleep efficiency, or sleep state distribution.     

No objectively measured sleep disturbances in children with attention‐deficit/hyperactivity disorder

The main goal of this study was to gain more insight into sleep disturbances in children with attention‐deficit/hyperactivity disorder, using objective measures of sleep quality and quantity. The evidence for sleep problems in children with attention‐deficit/hyperactivity disorder thus far is inconsistent, which might be explained by confounding influences of comorbid internalizing and externalizing problems and low socio‐economic status. We therefore investigated the mediating and moderating role of these factors in the association between attention‐deficit/hyperactivity disorder and sleep problems. To control for the effects of stimulant medication use, all participants were tested free of medication. Sixty‐three children with attention‐deficit/hyperactivity disorder and 61 typically developing children, aged 6–13 years, participated. Sleep was monitored for one to three school nights using actigraphy. Parent and teacher questionnaires assessed symptoms of attention‐deficit/hyperactivity disorder, internalizing behaviour, oppositional defiant disorder and conduct disorder. Results showed no differences between the attention‐deficit/hyperactivity disorder and typically developing group in any sleep parameter. Within the attention‐deficit/hyperactivity disorder group, severity of attention‐deficit/hyperactivity disorder symptoms was not related to sleep quality or quantity. Moderation analyses in the attention‐deficit/hyperactivity disorder group showed an interaction effect between attention‐deficit/hyperactivity disorder symptoms and internalizing and externalizing behaviour on total sleep time, time in bed and average sleep bout duration. The results of our study suggest that having attention‐deficit/hyperactivity disorder is not a risk factor for sleep problems. Internalizing and externalizing behaviour moderate the association between attention‐deficit/hyperactivity disorder and sleep, indicating a complex interplay between psychiatric symptoms and sleep.     

Conceptions of Moral and Social Rules in Rejected and Nonrejected Preschoolers

In this study, we examined the relationship between peer group status and conceptions of moral and social rules in preschoolers. Four- to 5-year-olds (N = 102) were classified into five status groups: controversial, popular, average, neglected, and rejected. There was a significant Peer Group Status x Rule Domain effect on conceptions of the punishment due to perpetrators of transgressions. In contrast to the rejected children, the four nonrejected groups accorded more punishment to violations of moral than of social rules. The distinction between the punishment due to the perpetrators of transgressions in the two domains was made most clearly by the small number of controversial children. These findings were unrelated to the length of time that the groups had been in attendance at child care centers (mean length of attendance = 191/2 months). As in previous studies, compared to transgressions against social rules, moral transgressions were regarded as naughtier, worthier of punishment, wrong if there was no punishment, and wrong outside specific social contexts. Boys' judgments of the wrongness of rule violations were less relative to context than were girls'. The relation of rule conceptions to children's social acceptance is discussed.     

Sleep and moral awareness

The implications of sleep for morality are only starting to be explored. Extending the ethics literature, we contend that because bringing morality to conscious attention requires effort, a lack of sleep leads to low moral awareness. We test this prediction with three studies. A laboratory study with a manipulation of sleep across 90 participants judging a scenario for moral content indicates that a lack of sleep leads to low moral awareness. An archival study of Google Trends data across 6 years highlights a national dip in Web searches for moral topics (but not other topics) on the Monday after the Spring time change, which tends to deprive people of sleep. Finally, a diary study of 127 participants indicates that (within participants) nights with a lack of sleep are associated with low moral awareness the next day. Together, these three studies suggest that a lack of sleep leaves people less morally aware, with important implications for the recognition of morality in others.     

Associations between everyday discrimination and sleep quality and duration among African-Americans over time in the Jackson Heart Study

Study ObjectivesAfrican-Americans have a high burden of poor sleep, yet, psychosocial determinants (e.g. discrimination) are understudied. We investigated longitudinal associations between everyday discrimination and sleep quality and duration among African-Americans (N = 3404) in the Jackson Heart Study.MethodsAt Exam 1 (2000–2004) and Exam 3 (2008–2013), participants completed the Everyday Discrimination Scale, rated their sleep quality (1 = poor to 5 = excellent), and self-reported hours of sleep. A subset of participants (N = 762) underwent 7-day actigraphy to objectively measure sleep duration and sleep quality (Sleep Exam 2012–2016). Changes in discrimination were defined as low stable (reference), increasing, decreasing, and high stable. Within-person changes in sleep from Exam 1 to Exam 3 were regressed on change in discrimination from Exam 1 to Exam 3 while adjusting for age, sex, education, income, employment, physical activity, smoking, body mass index, social support, and stress.ResultsAt Exam 1, the mean age was 54.1 (12.0) years; 64% were female, mean sleep quality was 3.0 (1.1) and 54% were short sleepers. The distribution of the discrimination change trajectories were 54.1% low stable, 13.5% increasing, 14.6% decreasing, and 17.7% were high stable. Participants who were in the increasing (vs. low stable) discrimination group had greater decrease in sleep quality. There was no association between change in discrimination and change in sleep duration. Among Sleep Exam participants, higher discrimination was cross-sectionally associated with shorter self-reported sleep duration, independent of stress.ConclusionDiscrimination is a unique stressor for African-Americans; thus, future research should identify interventions to reduce the burden of discrimination on sleep quality.     

Ethnicity moderates the influence of perceived social status on subjective sleep quality

It has long been recognized that socioeconomic status (SES) influences health and health-related behaviors, and it has been suggested that the adverse impact of low SES on health may be partly mediated by poor sleep quality. The relation between sleep and objective and subjective measures of SES has only been explored in a preliminary manner, providing indirect evidence that associations between SES and health might be explained, in part, by disrupted sleep. However, it remains unclear whether low SES directly affects sleep quality or whether the SES-sleep quality relation varies as a function of ethnicity given robust ethnic disparities across SES-related factors. This study examined the relation between perceived social status (i.e., individuals' perception of their socioeconomic standing) and subjective sleep quality among 149 college students, and examined the moderating effect of ethnicity to determine whether the magnitude or direction of association differed among Caucasian, Asian, and African Americans. Using hierarchical regressions and a dummy-coded ethnicity variable, results demonstrated significant moderation (ΔR? = 0.04, p = .02), such that both Asian (p = .04) and African Americans (p = .02) were significantly different from Caucasian Americans. Lower perceived social status was related to greater impairment in sleep quality for Asian Americans (β = -.37, p < .01) and African Americans (β = -.51, p < .01), but not Caucasian Americans (β = -.02, p = .87). These findings provide initial support for the negative impact of low perceived social status on sleep quality for specific subgroups of ethnic minorities.     

Subjective sleep‐related variables in those who have and have not experienced sleep paralysis

Research suggests that poor sleep quality is related to the occurrence of sleep paralysis, although the precise relationship between these two variables is unknown. This association has generated interest due to the related possibility that improving sleep quality could help to combat episodes of sleep paralysis. To date, studies examining the association between sleep quality and sleep paralysis have typically measured sleep quality using general measures such as the global score of the Pittsburgh Sleep Quality Index (PSQI). The aim of this study was to increase the precision of our understanding of the relationship between sleep paralysis and other aspects of sleep by investigating associations between different sleep‐related variables and sleep paralysis. Using data from the G1219 twin/sibling study, analyses were performed on 860 individuals aged 22–32 years (66% female). Results showed that two components of the PSQI, sleep latency and daytime dysfunction, were predictors of sleep paralysis. In addition, a number of other sleep‐related variables were related significantly to sleep paralysis. These were: insomnia symptoms, sleep problems commonly related to traumatic experiences, presleep arousal, cognitions about sleep and excessive daytime sleepiness. There was no relationship with sleep‐disordered breathing, diurnal preference or sleeping arrangements. Potential mechanisms underlying these results and suggestions for future research are discussed.     

Behavioral Correlates of Sleep-Disordered Breathing in Older Men

Study Objectives:

To examine the association between sleep-disordered breathing (SDB) and subjective measures of daytime sleepiness, sleep quality, and sleep-related quality of life in a large cohort of community-dwelling older men and to determine whether any association remained after adjustment for sleep duration.

Design:

Cross-sectional. The functional outcome measures of interest were daytime sleepiness (Epworth Sleepiness Scale, ESS), sleep-related symptoms (Pittsburgh Sleep Quality Index, PSQI), and sleep-related quality of life (Functional Outcomes of Sleep Questionnaire, FOSQ). Analysis of variance and adjusted regression analyses examined the association between these outcome measures and SDB severity and actigraphy-determined total sleep time (TST). We then explored whether associations with SDB were confounded by sleep duration by adjusting models for TST.

Setting:

Community-based sample in home and research clinic settings.

Participants:

Two-thousand eight-hundred forty-nine older men from the multicenter Osteoporotic Fractures in Men Study that began in 2000. All participants underwent in-home polysomnography for 1 night and wrist actigraphy for a minimum of 5 consecutive nights.

Interventions:

N/A.

Measurements and Results:

Participants were aged 76.4 ± 5.5 years and had an apnea-hypopnea index (AHI) of 17.0 ± 15.0. AHI and TST were weakly correlated. ESS scores individually were modestly associated with AHI and TST, but the association with AHI was attenuated by adjustment for TST. PSQI and FOSQ scores were largely not associated with measures of SDB severity but were modestly associated with TST.

Conclusions:

Daytime sleepiness, nighttime sleep disturbances, and sleep-related quality of life were modestly associated with TST. After adjustment for TST, there was no independent association with SDB severity. These results underscore the potential differences in SDB functional outcomes in older versus young and middle-aged adults.

Citation:

Kezirian EJ; Harrison SL; Ancoli-Israel S; Redline S; Ensrud K; Goldberg AN; Claman DM; Spira AP; Stone KL. Behavioral correlates of sleep-disordered breathing in older men. SLEEP 2009;32(2):253–261.     

Unique sleep‐stage transitions determined by obstructive sleep apnea severity,age and gender

In obstructive sleep apnea, patients’ sleep is fragmented leading to excessive daytime sleepiness and co‐morbidities like arterial hypertension. However, traditional metrics are not always directly correlated with daytime sleepiness, and the association between traditional sleep quality metrics like sleep duration and arterial hypertension is still ambiguous. In a development cohort, we analysed hypnograms from mild (n = 209), moderate (n = 222) and severe (n = 272) obstructive sleep apnea patients as well as healthy controls (n = 105) from the European Sleep Apnea Database. We assessed sleep by the analysis of two‐step transitions depending on obstructive sleep apnea severity and anthropometric factors. Two‐step transition patterns were examined for an association to arterial hypertension or daytime sleepiness. We also tested cumulative distributions of wake as well as sleep‐states for power‐laws (exponent α) and exponential distributions (decay time τ) in dependency on obstructive sleep apnea severity and potential confounders. Independent of obstructive sleep apnea severity and potential confounders, wake‐state durations followed a power‐law distribution, while sleep‐state durations were characterized by an exponential distribution. Sleep‐stage transitions are influenced by obstructive sleep apnea severity, age and gender. N2 → N3 → wake transitions were associated with high diastolic blood pressure. We observed higher frequencies of alternating (symmetric) patterns (e.g. N2 → N1 → N2, N2 → wake → N2) in sleepy patients both in the development cohort and in a validation cohort (n = 425). In conclusion, effects of obstructive sleep apnea severity and potential confounders on sleep architecture are small, but transition patterns still link sleep fragmentation directly to obstructive sleep apnea‐related clinical outcomes like arterial hypertension and daytime sleepiness.     

Behavioral correlates of sleep-disordered breathing in older women

STUDY OBJECTIVES: To examine the association between SDB and subjective measures of daytime sleepiness, sleep quality, and sleep related quality of life in a large cohort of primarily community-dwelling older women, specifically considering the relative importance of sleep duration in mediating these associations. DESIGN: Cross-sectional. The functional outcome measures of interest were daytime sleepiness (using the Epworth Sleepiness Scale, ESS), sleep-related symptoms (Pittsburgh Sleep Quality Index, PSQI), and sleep related quality of life (Functional Outcomes of Sleep Questionnaire, FOSQ). ANOVA and regression analyses examined the association between SDB severity (measured by indices of breathing disturbances and overnight oxygen saturation) and sleep time (by actigraphy) and these outcome measures. Regression models were adjusted for age, body mass index (BMI), and a medical comorbidity index. We specifically explored whether associations with indices of SDB were mediated by sleep deprivation by adjusting models for actigraphy-determined average total sleep time (TST) during the night. SETTING: Community-based sample examined in home and outpatient settings. PARTICIPANTS: 461 surviving older women from the multicenter Study of Osteoporotic Fractures were examined during Visit 8 from 2002-03. All participants underwent in-home overnight polysomnography for one night and wrist actigraphy for a minimum of 3 24-h periods and completed the above functional outcomes questionnaires. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Participants were aged 82.9 +/- 3.5 (mean +/- SD) years, had BMI of 27.9 +/- 5.1 kg/m2, and had an apnea-hypopnea index (AHI) of 15.7 +/- 15.1. AHI and TST demonstrated a weak correlation (r = -0.15). ESS score individually demonstrated a modest association with AHI, oxygen desaturation, and TST. The association of ESS score and AHI--but not oxygen desaturation-was attenuated to some extent by adjustment for TST. PSQI and FOSQ scores were not associated with measures of SDB severity or TST. CONCLUSIONS: After adjustment for TST, SDB severity in community-dwelling older women was not independently associated with self-reported daytime sleepiness, although there may be a modest association that is mediated through reduced TST. In older women, SDB severity was not associated with indices of sleep related symptoms or sleep related quality of life.     

Sleep health,diseases, and pain syndromes: findings from an electronic health record biobank

Study ObjectivesImplementation of electronic health record biobanks has facilitated linkage between clinical and questionnaire data and enabled assessments of relationships between sleep health and diseases in phenome-wide association studies (PheWAS). In the Mass General Brigham Biobank, a large health system-based study, we aimed to systematically catalog associations between time in bed, sleep timing, and weekly variability with clinical phenotypes derived from ICD-9/10 codes.MethodsSelf-reported habitual bed and wake times were used to derive variables: short (<7 hours) and long (≥9 hours) time in bed, sleep midpoint, social jetlag, and sleep debt. Logistic regression and Cox proportional hazards models were used to test cross-sectional and prospective associations, respectively, adjusted for age, gender, race/ethnicity, and employment status and further adjusted for body mass index.ResultsIn cross-sectional analysis (n = 34,651), sleep variable associations were most notable for circulatory system, mental disorders, and endocrine/metabolic phenotypes. We observed the strongest associations for short time in bed with obesity, for long time in bed and sleep midpoint with major depressive disorder, for social jetlag with hypercholesterolemia, and for sleep debt with acne. In prospective analysis (n = 24,065), we observed short time in bed associations with higher incidence of acute pain and later sleep midpoint and higher sleep debt and social jetlag associations with higher incidence of major depressive disorder.ConclusionsOur analysis reinforced that sleep health is a multidimensional construct, corroborated robust known findings from traditional cohort studies, and supported the application of PheWAS as a promising tool for advancing sleep research. Considering the exploratory nature of PheWAS, careful interrogation of novel findings is imperative.     

Strengths of associations between depressive symptoms and loneliness,perfectionistic concerns,risky alcohol use and physical activity across levels of sleep quality in Swedish university students: A cross-sectional study

Previous research shows that sleep quality may interact with some other predictors of depression, such that poor sleep could strengthen the association between these factors and depression. We aimed to determine the presence of statistical interactions between sleep quality and loneliness, risky alcohol use, perfectionistic concerns and/or physical inactivity in relation to depressive symptoms. Further, we aimed to describe the functional form of the statistical interactions and associations. We used a cross-sectional design and included 4262 Swedish university students. All measures were self-reported, sleep quality was measured with the Pittsburgh Sleep Quality Index, and depressive symptoms with the short-form Depression, Anxiety and Stress Scale. Regression models of increasing complexity (linear and non-linear, with and without interactions) were compared to determine the presence of associations and statistical interactions, and to explore the best functional form for these associations and interactions. Out-of-sample R² from repeated cross-validation was used to select the final models. We found that sleep quality was associated with depressive symptoms in all final models. Sleep quality showed a linear interaction with perfectionistic concerns in relation to depressive symptoms, such that perfectionistic concerns were more strongly associated with depressive symptoms when sleep quality was poor. Loneliness, risky alcohol use and physical inactivity were non-linearly associated with depressive symptoms but did not interact with sleep quality. We concluded that out of the four examined variables, only perfectionistic concerns interacted with sleep quality in relation to depressive symptoms. This interaction was weak and explained little of the overall variance in depressive symptoms.     

Work stressors,depressive symptoms and sleep quality among US Navy members: a parallel process latent growth modelling approach across deployment

The present study examined whether work stressors contribute to sleep problems and depressive symptoms over the course of deployment (i.e. pre‐deployment, post‐deployment and 6‐month reintegration) among US Navy members. Specifically, we examined whether depressive symptoms or sleep quality mediate the relationships between work stressors and these outcomes. Participants were 101 US Navy members who experienced an 8‐month deployment after Operational Enduring Freedom/Operation Iraqi Freedom. Using piecewise latent growth models, we found that increased work stressors were linked to increased depressive symptoms and decreased sleep quality across all three deployment stages. Further, increases in work stressors from pre‐ to post‐deployment contributed to poorer sleep quality post‐deployment via increasing depressive symptoms. Moreover, sleep quality mediated the association between increases in work stressors and increases in depressive symptoms from pre‐ to post‐deployment. These effects were maintained from post‐deployment through the 6‐month reintegration. Although preliminary, our results suggest that changes in work stressors may have small, but significant implications for both depressive symptoms and quality of sleep over time, and a bi‐directional relationship persists between sleep quality and depression across deployment. Strategies that target both stress and sleep could address both precipitating and perpetuating factors that affect sleep and depressive symptoms.     

Infant feeding practices and sleep development in pre‐schoolers from the EDEN mother–child cohort

Sleep problems affect 20%–30% of toddlers and preschoolers. Few longitudinal studies focused on the impact of infant feeding practices on sleep. We aimed to study the associations between feeding practices up to 8 months and trajectories of sleep quantity or quality from 2 to 5–6 years. Analyses included 1,028 children from the EDEN mother–child cohort. Data were collected by self‐administered questionnaires. Associations between feeding practices (breastfeeding, complementary feeding, use of thickened infant formula, night feeding) and sleep trajectories (sleep‐onset difficulties, night waking, nighttime in bed) were analysed by multiple logistic regressions. Predominant breastfeeding for more than 4 months was associated with lower risk for belonging to the persistent sleep‐onset difficulties trajectory. Night feeding at 4 months or at 2 years old was associated with higher risk for belonging to the persistent sleep‐onset difficulties trajectory, and night feeding at 8 months was associated with higher risk for night waking and higher risk for short nighttime in bed. Early introduction (< 4 months) to complementary foods (excluding baby cereals) was related to lower risk for short nighttime in bed. Use of baby cereals or thickened infant formula was related neither to sleep quality nor to sleep quantity. In conclusion, infant feeding practices are associated with sleep trajectories in preschoolers, with notably a potential protective role of breastfeeding. Further researches are needed to clarify the mechanisms of these relationships.     

The temporal relationships between sleep, cortisol, and lung functioning in youth with asthma

OBJECTIVES: This study tested the directionality of the association between sleep and health outcomes in youth with asthma. METHOD: Thirty-eight youth with asthma (aged 9-19) completed a daily diary study on sleep, asthma symptoms, peak expiratory flow (PEF) measures, and salivary cortisol samples. RESULTS: Greater quantity of sleep predicted lower PEF% [beta(32) = -.33, p =.02], and lower daily cortisol output [beta(33) = -.31, p =.07] the following day. Additionally, poorer self-reported sleep quality predicted more severe symptoms the next day [beta(33) =.27, p =.05]. In contrast, PEF%, cortisol, and asthma symptoms did not significantly predict self-reported sleep quantity or quality the next night. CONCLUSIONS: Results suggest that sleep may affect subsequent health outcomes, rather than asthma impacting subsequent sleep, indicating the potential benefits of targeting sleep behaviors in youth with asthma.     

Joint associations of body mass index and waist-to-height ratio with sleep duration among Saudi adolescents

Background: Numerous studies have shown significant associations between short sleep duration and overall or abdominal obesity. However, no study has reported on the joint association of body mass index (BMI) and waist-to-height ratio (WHtR) with sleep duration in adolescents.

Aim: To examine the joint associations of BMI and WHtR with sleep duration among Saudi adolescents.

Subjects and methods: A school-based cross-sectional study was conducted involving 2852 secondary-school students (51.7% females) aged 15–19 years, randomly selected using a multistage stratified cluster sampling. Self-reported sleep duration was assessed and BMI was classified into high and low categories according to the IOTF classification, whereas WHtR categories were based on above and below 0.5.

Results: The low BMI–low WHtR category had the longest mean sleep duration (7.27 hours/day), whereas the high BMI-high WHtR group had the shortest sleep duration (7.02 hours/day; p?=?0.003) (aOR?=?0.832, 95% CI?=?0.698–0.992, p?=?0.040). In addition, high BMI–low WHtR or low BMI–high WHtR groups didn’t significantly associate with reduced sleep duration among adolescents.

Conclusion: The joint association of high BMI–high WHtR increases adolescent’s risk of having reduced sleep duration. Future research should seek to confirm such findings and provide an explanation for this association.     

Terror and bliss? Commonalities and distinctions between sleep paralysis,lucid dreaming,and their associations with waking life experiences

Sleep paralysis and lucid dreaming are both dissociated experiences related to rapid eye movement (REM) sleep. Anecdotal evidence suggests that episodes of sleep paralysis and lucid dreaming are related but different experiences. In this study we test this claim systematically for the first time in an online survey with 1928 participants (age range: 18–82 years; 53% female). Confirming anecdotal evidence, sleep paralysis and lucid dreaming frequency were related positively and this association was most apparent between lucid dreaming and sleep paralysis episodes featuring vestibular‐motor hallucinations. Dissociative experiences were the only common (positive) predictor of both sleep paralysis and lucid dreaming. Both experiences showed different associations with other key variables of interest: sleep paralysis was predicted by sleep quality, anxiety and life stress, whereas lucid dreaming was predicted by a positive constructive daydreaming style and vividness of sensory imagery. Overall, results suggest that dissociative experiences during wakefulness are reflected in dissociative experiences during REM sleep; while sleep paralysis is related primarily to issues of sleep quality and wellbeing, lucid dreaming may reflect a continuation of greater imaginative capacity and positive imagery in waking states.     

The Relationships Between Sleep and Measures of Health and Weil-Being in College Students: A Repeated Measures Approach

Abstract

The stability of subjective measures of sleep, health, and well-being, as well as the stability of the relationships between sleep and health and well-being were assessed over 3 months. Healthy college students with no consistent sleep complaints completed a 7-day sleep log and battery of surveys related to health and well-being at 3 separate times during the 3 months. Measures of health and well-being were more strongly related to the quality than to the quantity of sleep. Further analyses using the repeated measures results found that participants reported improved sleep and better health, but the affect balance, life satisfaction, and mood states were unchanged across the 3 testing periods. The relationships between the measures of sleep and measures of health and well-being remained constant across the experimental period. Even when working with a non-sleep-disturbed population, healthcare professionals should consider sleep quality as a consistent correlate of daily health and well-being.     

Analysis of dynamic,bidirectional associations in older adult physical activity and sleep quality

Sleep quality and physical activity (PA) appear to be interrelated; thus, by promoting one behaviour, it may be possible to improve the other in older adults. Examination of the within‐person day‐to‐day variation in PA and sleep quality could potentially elucidate the directionality of the association of these behaviours. We measured sleep quality (i.e. fragmentation, efficiency, duration and latency) and moderate‐to‐vigorous PA using the MotionWatch8© over 14 consecutive days and nights in community‐dwelling adults (n = 152; age range 53–101 years). Multilevel modelling estimated within‐subject autoregressive and cross‐lagged effects and between‐subject associations between PA and sleep quality. On days when individuals engaged in a high amount of PA on one day (relative to their averages), they were more likely to engage in a high amount of PA on the next day (estimate, 0.19; 95% CI, 0.14, 0.24). Nights in which individuals had a long sleep latency were followed by nights in which they also had a long sleep latency (estimate, 0.09; 95% CI, 0.03, 0.14). In contrast, nights in which individuals slept for a long period of time were followed by nights in which they slept relatively less than their averages (estimate, ?0.09; 95% CI, ?0.13, ?0.04). When individuals engaged in a large amount of PA during the day, they tended to sleep longer that following night (estimate, 0.01; 95% CI, 0.001, 0.02). All other associations between PA and sleep quality were not significant. Increasing PA therefore might increase sleep duration in older adults.