How do children with autism spectrum disorder form gist memory during sleep? A study of slow oscillation–spindle coupling

Sleep is assumed to support memory through an active systems consolidation process that does not only strengthen newly encoded representations but also facilitates the formation of more abstract gist memories. Studies in humans and rodents indicate a key role of the precise temporal coupling of sleep slow oscillations (SO) and spindles in this process. The present study aimed at bolstering these findings in typically developing (TD) children, and at dissecting particularities in SO-spindle coupling underlying signs of enhanced gist memory formation during sleep found in a foregoing study in children with autism spectrum disorder (ASD) without intellectual impairment. Sleep data from 19 boys with ASD and 20 TD boys (9–12 years) were analyzed. Children performed a picture-recognition task and the Deese–Roediger–McDermott (DRM) task before nocturnal sleep (encoding) and in the next morning (retrieval). Sleep-dependent benefits for visual-recognition memory were comparable between groups but were greater for gist abstraction (recall of DRM critical lure words) in ASD than TD children. Both groups showed a closely comparable SO-spindle coupling, with fast spindle activity nesting in SO-upstates, suggesting that a key mechanism of memory processing during sleep is fully functioning already at childhood. Picture-recognition at retrieval after sleep was positively correlated to frontocortical SO-fast-spindle coupling in TD children, and less in ASD children. Critical lure recall did not correlate with SO-spindle coupling in TD children but showed a negative correlation (r = −.64, p = .003) with parietal SO-fast-spindle coupling in ASD children, suggesting other mechanisms specifically conveying gist abstraction, that may even compete with SO-spindle coupling.     

Electroencephalographic sleep macrostructure and sleep spindles in early infancy

Study ObjectivesSleep features in infancy are potential biomarkers for brain maturation but poorly characterized. We describe normative values for sleep macrostructure and sleep spindles at 4–5 months of age.MethodsHealthy term infants were recruited at birth and had daytime sleep electroencephalograms (EEGs) at 4–5 months. Sleep staging was performed and five features were analyzed. Sleep spindles were annotated and seven quantitative features were extracted. Features were analyzed across sex, recording time (am/pm), infant age, and from first to second sleep cycles.ResultsWe analyzed sleep recordings from 91 infants, 41% females. Median (interquartile range [IQR]) macrostructure results: sleep duration 49.0 (37.8–72.0) min (n = 77); first sleep cycle duration 42.8 (37.0–51.4) min; rapid eye movement (REM) percentage 17.4 (9.5–27.7)% (n = 68); latency to REM 36.0 (30.5–41.1) min (n = 66). First cycle median (IQR) values for spindle features: number 241.0 (193.0–286.5), density 6.6 (5.7–8.0) spindles/min (n = 77); mean frequency 13.0 (12.8–13.3) Hz, mean duration 2.9 (2.6–3.6) s, spectral power 7.8 (4.7–11.4) µV², brain symmetry index 0.20 (0.16–0.29), synchrony 59.5 (53.2–63.8)% (n = 91). In males, spindle spectral power (µV²) was 24.5% lower (p = .032) and brain symmetry index 24.2% higher than females (p = .011) when controlling for gestational and postnatal age and timing of the nap. We found no other significant associations between studied sleep features and sex, recording time (am/pm), or age. Spectral power decreased (p < .001) on the second cycle.ConclusionThis normative data may be useful for comparison with future studies of sleep dysfunction and atypical neurodevelopment in infancy. Clinical Trial Registration: BABY SMART (Study of Massage Therapy, Sleep And neurodevelopMenT) (BabySMART)URL: https://clinicaltrials.gov/ct2/show/results/NCT03381027?view=results.ClinicalTrials.gov Identifier: NCT03381027     

Suicidal ideation is associated with nighttime wakefulness in a community sample

Study ObjectivesNocturnal wakefulness is a risk factor for suicide and suicidal ideation in clinical populations. However, these results have not been demonstrated in general community samples or compared to sleep duration or sleep quality. The present study explored how the timing of wakefulness was associated with suicidal ideation for weekdays and weekends.MethodsData were collected from 888 adults aged 22–60 as part of the Sleep and Healthy Activity, Diet, Environment, and Socialization study. Suicidal ideation was measured by the Patient Health Questionnaire-9, while timing of wakefulness was estimated from the Sleep Timing Questionnaire. Binomial logistic regressions estimated the association between nocturnal (11 pm–5 am) and morning (5 am–11 am) wakefulness and suicidal ideation.ResultsNocturnal wakefulness was positively associated with suicidal ideation on weekdays (OR: 1.44 [1.28–1.64] per hour awake between 11:00 pm and 05:00 am, p < 0.0001) and weekends (OR: 1.22 [1.08–1.39], p = 0.0018). Morning wakefulness was negatively associated with suicidal ideation on weekdays (OR: 0.82 [0.72–0.92] per hour awake between 05:00 am and 11:00 am, p = 0.0008) and weekends (OR: 0.84 [0.75–0.94], p = 0.0035). These associations remained significant when adjusting for sociodemographic factors. Additionally, nocturnal wakefulness on weekdays was associated with suicidal ideation when accounting for insomnia, sleep duration, sleep quality, and chronotype (OR 1.25 [1.09–1.44] per hour awake, p = 0.002).ConclusionWakefulness at night was consistently associated with suicidal ideation. Additionally, morning wakefulness was negatively associated with suicidal ideation in some models. Although these findings are drawn from a non-clinical sample, larger longitudinal studies in the general population are needed to confirm these results.     

Trajectories of reported sleep duration associate with early childhood cognitive development

Study ObjectivesExamine how different trajectories of reported sleep duration associate with early childhood cognition.MethodsCaregiver-reported sleep duration data (n = 330) were collected using the Brief Infant Sleep Questionnaire at 3, 6, 9, 12, 18, and 24 months and Children’s Sleep Habits Questionnaire at 54 months. Multiple group-based day-, night-, and/or total sleep trajectories were derived—each differing in duration and variability. Bayley Scales of Infant and Toddler Development-III (Bayley-III) and the Kaufman Brief Intelligence Test- 2 (KBIT-2) were used to assess cognition at 24 and 54 months, respectively.ResultsCompared to short variable night sleep trajectory, long consistent night sleep trajectory was associated with higher scores on Bayley-III (cognition and language), while moderate/long consistent night sleep trajectories were associated with higher KBIT-2 (verbal and composite) scores. Children with a long consistent total sleep trajectory had higher Bayley-III (cognition and expressive language) and KBIT-2 (verbal and composite) scores compared to children with a short variable total sleep trajectory. Moderate consistent total sleep trajectory was associated with higher Bayley-III language and KBIT-2 verbal scores relative to the short variable total trajectory. Children with a long variable day sleep had lower Bayley-III (cognition and fine motor) and KBIT-2 (verbal and composite) scores compared to children with a short consistent day sleep trajectory.ConclusionsLonger and more consistent night- and total sleep trajectories, and a short day sleep trajectory in early childhood were associated with better cognition at 2 and 4.5 years.     

Good perceived sleep quality protects against the raised risk of respiratory infection during sleep restriction in young adults

Study ObjectivesProspectively examine the association between sleep restriction, perceived sleep quality (PSQ) and upper respiratory tract infection (URTI).MethodsIn 1318 military recruits (68% males) self-reported sleep was assessed at the beginning and end of a 12-week training course. Sleep restriction was defined as an individualized reduction in sleep duration of ≥2 hours/night compared with civilian life. URTIs were retrieved from medical records.ResultsOn commencing training, approximately half of recruits were sleep restricted (52%; 2.1 ± 1.6 h); despite the sleep debt, 58% of recruits with sleep restriction reported good PSQ. Regression adjusted for covariates showed that recruits commencing training with sleep restriction were more likely to suffer URTI during the course (OR = 2.93, 95% CI 1.29–6.69, p = .011). Moderation analysis showed this finding was driven by poor PSQ (B = −1.12, SE 0.50, p = .023), as no significant association between sleep restriction and URTI was observed in recruits reporting good PSQ, despite a similar magnitude of sleep restriction during training. Associations remained in the population completing training, accounting for loss to follow-up. Recruits reporting poor PSQ when healthy at the start and end of training were more susceptible to URTI (OR = 3.16, 95% CI 1.31–7.61, p = .010, vs good PSQ).ConclusionGood perceived sleep quality was associated with protection against the raised risk of respiratory infection during sleep restriction. Studies should determine whether improvements in sleep quality arising from behavioral sleep interventions translate to reduced respiratory infection during sleep restriction.     

Racial disparities in sleep-related cardiac function in young,healthy adults: implications for cardiovascular-related health

Study ObjectivesConsiderable evidence shows that individuals from marginalized racial/ethnic groups in the United States experience greater rates of sleep disturbance and cardiovascular complications. Because sleep is a modifiable factor that is critically involved in cardiovascular health, improved understanding of the association between sleep and cardiovascular health during early adulthood can prevent cardiovascular disparities. This study examined racial/ethnic differences in cardiovascular function during sleep using heart rate and heart-rate-variability analyses.MethodsParticipants in this laboratory-based sleep study included healthy, “good sleepers” who were in early adulthood and resided in the United States at the time of participation (14 non-Hispanic Black [NHB; age = 30.9 (6.6), 57% female], 12 Asian [Asian, age = 26.0 (5.2), 42% female], and 24 non-Hispanic white [NHW; age = 24.6 (5.8), 79% female]).ResultsAfter adjusting for demographic factors and an apnea–hypopnea index, we found significantly higher heart rate within NREM Stage 2 (N2) (b = −22.6, p = .04) and REM sleep (b = −25.8, p =.048) and lower heart rate variability during N2 sleep (b = −22.6, p = .04) among NHB individuals compared with NHW individuals. Furthermore, NHB and Asian participants demonstrated significantly lower percent of time in slow wave sleep (SWS) compared with NHW participants (NHB: b = −22.6, p =.04; Asian: b = −22.6, p = .04). Individuals’ percent of time in SWS significantly mediated differences in heart rate during N2 (indirect = 0.94, 95% CI [0.03, 2.68]) and REM sleep (indirect = 1.02, 95% CI [0.04, 3.04]).ConclusionsOur results showed disparities in sleep-related cardiovascular function in early adulthood that are mediated by SWS. These data suggest targeting sleep health in early adulthood might help reduce cardiovascular disease burden on individuals from marginalized groups.     

Brief Behavioral Sleep Intervention for Adolescents: An Effectiveness Study

Sleep disturbances are common among adolescents, but there are no brief interventions to treat them. The objective of this study was to evaluate the effectiveness of a brief semistructured, individually delivered sleep intervention to ameliorate adolescents' sleeping difficulties and lengthen sleep duration. All students aged 16–18 years in a high school were screened for sleeping difficulties and 36 students with the highest sleep problem scores were invited to the intervention. Postintervention improvements were observed on self-reported and actiwatch-registered sleep duration, self-reported sleep quality and sleep latency, perceived stress and anxiety (all p values < 0.001). However, objectively measured sleep efficiency and sleep latency did not change (p > 0.05). A brief individual sleep intervention can be effective in lengthening sleep duration and improving subjective sleep quality and well-being among adolescents.     

Reduced Sleep Acutely Influences Sedentary Behavior and Mood But Not Total Energy Intake in Normal-Weight and Obese Women

Using a crossover design, 22 normal-weight and 22 obese women completed two free-living sleep conditions: (a) Normal Sleep: night of ~8 hr time in bed; and (b) Reduced Sleep: night of < 5 hr time in bed). Outcome measures were energy intake, physical activity and sedentary time, and mood. Sleep time was 7.7 ± 0.3 and 4.8 ± 0.2 hrs during the Normal Sleep and Reduced Sleep conditions, respectively (F = 1791.94; p < 0.0001). Energy intake did not differ between groups or as a function of sleep condition (F = 2.46; p = 0.1244). Sedentary time was ~ 30 min higher after the Reduced Sleep condition (F = 4.98; p = 0.0318); other physical activity outcomes were not different by condition (p > 0.05). Total mood score, depression, anger, vigor, fatigue, and confusion were worse after Reduced Sleep (p < 0.05). Reducing sleep acutely and negatively influenced sedentary time and mood in normal-weight and obese women.     

Determinants of postpartum sleep duration and sleep efficiency in minority women

Study ObjectivesTo examine demographic, psychosocial, and behavioral determinants of postpartum sleep duration and sleep efficiency among a cohort of black and Latina women.MethodsData were from 148 women (67% black, 32% Latina) at 5 months postpartum, recruited from an academic medical center in Philadelphia. Relevant demographic, psychosocial and behavioral predictors were assessed via questionnaire. Nocturnal sleep was objectively measured for 1 week using wrist actigraphy. Sleep duration was examined as a continuous variable and in categories (<7 versus ≥7 h per night); sleep efficiency was examined as a continuous variable. Independent multiple linear regression models were built to evaluate significant determinants of sleep.ResultsAdjusted models revealed that breastfeeding, having a bedtime after midnight, and being employed were associated with shorter sleep duration (–25–33 min, all p < 0.05). Multiparity, being unmarried, being employed, breastfeeding, having a bedtime after midnight, bedsharing, and responding to infant awakenings by getting up immediately rather than waiting a few minutes to see if the infant fell back asleep, were all significant determinants of sleeping <7 h per night (OR varying: 2.29–4.59, all p < 0.05). Bedsharing was the only variable identified from the multiple regression model that associated with poorer sleep efficiency (–3.8%, p < 0.05).ConclusionsFindings may inform interventions for improving postpartum sleep in socioeconomically disadvantaged, racial/ethnic minority postpartum women.     

Sleep Variability Among Older Adults With Insomnia: Associations With Sleep Quality and Cardiometabolic Disease Risk

Sleep variability has been linked to poor subjective sleep quality, but few studies have investigated effects on physical health. In this study, we evaluated cross sectional associations and change over time in objective sleep variability of adults with insomnia and short sleep duration who were participating in a non-pharmacologic intervention study. Results indicated greater variability in objective sleep measures were associated with poorer subjective sleep quality (p < 0.05). Higher sleep duration variability was associated with higher HbA1c (p < 0.01) and sleep onset time variability was associated with higher BMI (p < 0.05). Sleep efficiency and WASO variability decreased with intervention (p < 0.05). These results indicate that objective sleep variability may be an important feature for the assessment of insomnia outcomes.     

The effect of sleep–wake intraindividual variability in digital cognitive behavioral therapy for insomnia: a mediation analysis of a large-scale RCT

Study ObjectivesDigital cognitive behavioral therapy for insomnia (dCBT-I) is an effective treatment for insomnia. However, less is known about mediators of its benefits. The aim of the present study was to test if intraindividual variability in sleep (IIV) was reduced with dCBT-I, and whether any identified reduction was a mediator of dCBT-I on insomnia severity and psychological distress.MethodsIn a two-arm randomized controlled trial (RCT), 1720 adults with insomnia (dCBT-I = 867; patient education about sleep = 853) completed the Insomnia Severity Index (ISI), the Hospital Anxiety and Depression Scale (HADS) and sleep diaries, at baseline and 9-week follow-up. Changes in IIV were analyzed using linear mixed modeling followed by mediation analyses of ISI, HADS, and IIV in singular sleep metrics and composite measures (behavioral indices (BI-Z) and sleep disturbance indices (SI-Z)).ResultsdCBT-I was associated with reduced IIV across all singular sleep metrics, with the largest between-group effect sizes observed for sleep onset latency (SOL). Reduced IIV for SOL and wake after sleep onset had the overall greatest singular mediating effect. For composite measures, SI-Z mediated change in ISI (b = −0.74; 95% confidence interval (CI) −1.04 to −0.52; 13.3%) and HADS (b = −0.40; 95% CI −0.73 to −0.18; 29.2%), while BI-Z mediated minor changes.ConclusionReductions in IIV in key sleep metrics mediate significant changes in insomnia severity and especially psychological distress when using dCBT-I. These findings offer important evidence regarding the therapeutic action of dCBT-I and may guide the future development of this intervention.Clinical trials Name: Overcoming Insomnia: Impact on Sleep, Health and Work of Online CBT-I Registration number: NCT02558647 URL: https://clinicaltrials.gov/ct2/show/NCT02558647?cond=NCT02558647&draw=2&rank=1     

Patterns of concomitant prescription,over-the-counter and natural sleep aid use over a 12-month period: a population based study

Study ObjectivesConcomitant patterns of sleep aid use may provide insight for understanding the transition to chronic sleep medication use. Therefore, we sought to characterize the trajectories of concomitant natural product (NP), over-the-counter (OTC), and prescribed (Rx) sleep aid use in a population-based sample over 12-months.MethodsSelf-reported data on the use of NP, OTC, and Rx sleep aids were extracted from a Canadian longitudinal study on the natural history of insomnia (N = 3416, M age = 49.7 ± 14.7 years old; 62% women) at baseline, 6-month, and 12-month. Latent class growth modeling was used to identify latent class trajectories using MPlus Version 7. Participants completed a battery of clinical measures: Ford Insomnia Response to Stress Test, abbreviated Dysfunctional Beliefs and Attitudes about Sleep Scale, Beck Depression Inventory, Insomnia Severity Index and, the Pittsburgh Sleep Quality Index. Associations between class membership and baseline covariates were evaluated.ResultsConcurrent sleep aid use fell into six distinct latent class trajectories over a 12-month period: Minimal Use (74.5%), Rx-Dominant (11.3%), NP-Dominant (6.3%), OTC-Dominant (4.3%), Rx-NP-Dominant (2.4%), and Rx-OTC-Dominant (1.1%). The three latent classes with prominent prescribed agent use predicted greater incidence of healthcare professional consultations for their sleep (p < 0.05), poorer sleep quality (p < 0.001), elevated dysfunctional sleep beliefs (p < 0.001), and sleep reactivity (p < 0.001). Compared to the other four latent classes, clinical profiles of Rx-NP-dominant and Rx-OTC-dominant groups endorsed greater severity across measures.ConclusionsPatterns of sleep aid use may provide insight for identifying individuals who may be vulnerable to inappropriate self-medicating practices.     

Poor sleep correlates with biomarkers of neurodegeneration in mild traumatic brain injury patients: a CENC study

Study ObjectivesSleep disorders affect over half of mild traumatic brain injury (mTBI) patients. Despite evidence linking sleep and neurodegeneration, longitudinal TBI-related dementia studies have not considered sleep. We hypothesized that poor sleepers with mTBI would have elevated markers of neurodegeneration and lower cognitive function compared to mTBI good sleepers and controls. Our objective was to compare biomarkers of neurodegeneration and cognitive function with sleep quality in warfighters with chronic mTBI.MethodsIn an observational warfighters cohort (n = 138 mTBI, 44 controls), the Pittsburgh Sleep Quality Index (PSQI) was compared with plasma biomarkers of neurodegeneration and cognitive scores collected an average of 8 years after injury.ResultsIn the mTBI cohort, poor sleepers (PSQI ≥ 10, n = 86) had elevated plasma neurofilament light (NfL, $\bar{x}$ = 11.86 vs 7.91 pg/mL, p = 0.0007, d = 0.63) and lower executive function scores by the categorical fluency ($\bar{x}$ = 18.0 vs 21.0, p = 0.0005, d = –0.65) and stop-go tests ($\bar{x}$ = 30.1 vs 31.1, p = 0.024, d = –0.37). These findings were not observed in controls (n = 44). PSQI predicted NfL (beta = 0.22, p = 0.00002) and tau (beta = 0.14, p = 0.007), but not amyloid β42. Poor sleepers showed higher obstructive sleep apnea (OSA) risk by STOP-BANG scores ($\bar{x}$ = 3.8 vs 2.7, p = 0.0005), raising the possibility that the PSQI might be partly secondary to OSA.ConclusionsPoor sleep is linked to neurodegeneration and select measures of executive function in mTBI patients. This supports implementation of validated sleep measures in longitudinal studies investigating pathobiological mechanisms of TBI related neurodegeneration, which could have therapeutic implications.     

Association between Physical Activity,Sedentary Behaviors,Sleep, Diet,and Adiposity among Children and Adolescents in China

IntroductionPhysical activity (PA), sedentary behaviors (SB), sleep, and diet are related to adiposity among children and adolescents. However, there may be interactions between PA, SB, sleep, and diet, and these lifestyle behaviors may work together to affect body weight. The purpose of this study was to explore the impact of multiple lifestyle behaviors of PA, SB, sleep, and diet on childhood adiposity (body mass index z-score and overweight/obesity), and to investigate the effect of meeting multiple guidelines on adiposity among children and adolescents in China.MethodsCross-sectional results were based on 28,048 children aged 6–17 years from the China National Nutrition and Health Surveillance in 2010–2012. Information about PA, SB, and sleep was measured through interview-administered questionnaire. Dietary intake was assessed with food frequency questionnaire. The associations between multiple lifestyle behaviors and BMI z-score and overweight/obese were examined.ResultsThe prevalence of overweight/obesity in the participants was 19.2%. The average time of moderate-to-vigorous PA (MVPA), leisure SB, and sleep was 76.7 ± 45.5 min, 2.9 ± 1.4 h, and 8.5 ± 1.1 h per day, respectively. The China Dietary Guidelines Index for Youth (CDGI-Y) score was 62.6 ± 11.0. Sleep duration and diet score were negative associated with BMI z-score (both p < 0.001). MVPA and SB time were positive associated with BMI z-score (p = 0.041, 0.004). Meeting the SB, sleep, and diet guidelines had a lower BMI z-score (all p < 0.01) and lower odds of overweight/obesity (all p < 0.05). There were significant interactions between PA and diet. Compared with meeting no guidelines, those who met multiple guidelines had a lower risk of overweight/obesity (all p < 0.01). The more guidelines the participants met, the lower odds of overweight/obesity (p for trend <0.001).ConclusionsPA, SB, sleep, and diet are important behaviors associated with adiposity among children and adolescents. Attaining adequate amounts of appropriate multiple behaviors provided an additional benefit. It is important for children to meet recommended behavioral guidelines or recommendations. Interventions that aim to improve awareness of and compliance with these guidelines are needed in future.     

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.     

Meta-analysis of age and actigraphy-assessed sleep characteristics across the lifespan

Study ObjectivesSleep quantity and continuity vary across the lifespan. Actigraphy is a reliable and widely used behavioral measure of sleep in research and personal health monitoring. This meta-analysis provides a novel examination of whether age (in years) is associated with actigraphy-assessed sleep across the lifespan.MethodsA systematic search of PubMed, Embase.com, Cochrane CENTRAL, and PsycINFO using “actigraphy” and “sleep” terms provided 7079 titles/abstracts; studies of individuals with known psychiatric or medical comorbidities were excluded. Ninety-one articles (N = 23 365) provided data for six meta-analyses examining sleep duration (k = 89), sleep efficiency (k = 58), bedtime (k = 19) and waketime (k = 9) for individuals ages 6–21, and bedtime (k = 7) and waketime (k = 7) for individuals ages 22 and older.ResultsAt older ages, sleep duration was shorter (r = −0.12) and sleep efficiency was lower (r = −0.05). Older age was associated with later bedtime (r = 0.37) and wake-up time (r = 0.24) from ages 6–21, whereas older age was associated with earlier bedtime (r = −0.66) and wake-up time (r = −0.59) for ages 22 and above. The strength of these associations was modified by study continent, but not by any other moderator.ConclusionsAge was negatively associated with actigraphy-assessed sleep duration and efficiency, but the effects were small in magnitude. On the other hand, large associations were observed between age and sleep timing, despite a smaller literature and the absence of analyzable data for ages 30–60. Changes in sleep timing, rather than changes in sleep duration or continuity, may better characterize the effects of age on human sleep.     

Treating insomnia symptoms with medicinal cannabis: a randomized,crossover trial of the efficacy of a cannabinoid medicine compared with placebo

Study ObjectivesThis randomized, double-blind, placebo-controlled, crossover study was conducted to evaluate the safety and efficacy of 2 weeks of nightly sublingual cannabinoid extract (ZTL-101) in treating chronic insomnia (symptoms ≥3 months).MethodsCo-primary study endpoints were safety of the medication based on adverse event reporting and global insomnia symptoms (Insomnia Severity Index [ISI]). Secondary endpoints included: self-reported (sleep diary), actigraphy-derived, and polysomnography measurements of sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), sleep efficiency (SE); and self-reported assessments of sleep quality (sSQ) and feeling rested upon waking. Adjusted mean differences between placebo and ZTL-101 were calculated.ResultsTwenty-three of 24 randomized participants (n = 20 female, mean age 53 ± 9 years) completed the protocol. No serious adverse events were reported. Forty mild, nonserious, adverse events were reported (36 during ZTL-101) with all but one resolving overnight or soon after waking. Compared to placebo, ZTL-101 decreased ISI (−5.07 units [95% CI: −7.28 to −2.86]; p = 0.0001) and self-reported SOL (−8.45 min [95% CI: −16.33 to −0.57]; p = 0.04) and increased self-reported TST (64.6 min [95% CI: 41.70 to 87.46]; p < 0.0001), sSQ (0.74 units [95% CI: 0.51 to 0.97]; p < 0.0001), and feeling of being rested on waking (0.51 units [95% CI: 0.24 to 0.78]; p = 0.0007). ZTL-101 also decreased actigraphy-derived WASO (−10.2 min [95% CI: −16.2 to −4.2]; p = 0.002), and increased actigraphy-derived TST (33.4 min [95% CI: 23.07 to 43.76]; p < 0.001) and SE (2.9% [95% CI: 2.0 to 3.8]; p = 0.005).ConclusionsTwo weeks of nightly sublingual administration of a cannabinoid extract (ZTL-101) is well tolerated and improves insomnia symptoms and sleep quality in individuals with chronic insomnia symptoms.Clinical TrialANZCTR; anzctr.org.au; ACTRN12618000078257.     

Association of sleep with cognitive function during retirement transition: the Whitehall II study

Study ObjectivesSleep duration and difficulties have been shown to associate with cognitive function. This study examined how changes in sleep and in cognitive function are associated during retirement transition.MethodsThe study population consisted of 2980 Whitehall II study participants, who retired during the follow-up, whose sleep was queried, and cognitive function measured (inductive reasoning and verbal memory) before and after retirement (follow-up 16 years). Using the last information on sleep before and the first after retirement, participants were categorized into constantly without (59%), increasing (13%), decreasing (11%), and constantly with (18%) sleep difficulties; and constantly short (26%), increasing (19%), decreasing (8.5%), and constantly mid-range (47%) sleep duration. Change in cognitive function during retirement transition was examined by sleep change groups using linear regression analyses with generalized estimating equations.ResultsMore pronounced decline in inductive reasoning during retirement transition was observed among participants with increasing sleep difficulties (−1.96, 95% CI −2.52 to −1.41) compared to those constantly without sleep difficulties (−1.25, 95% CI −1.52 to −0.98) and constantly with sleep difficulties (−1.26, 95% CI −1.75 to −0.92). Decreasing sleep difficulties (−0.64, 95% CI −0.86 to −0.43) were associated with a more pronounced decline in verbal memory when compared to constantly without sleep difficulties (−0.42, 95% CI −0.52 to −0.32) in post-retirement period. No statistically significant differences across sleep duration groups in cognitive function were observed.ConclusionsIncreasing and decreasing sleep difficulties may be associated with accelerated decline in cognitive function during retirement transition and post-retirement.     

Longer Weekly Sleep Duration Predicts Greater 3-Month BMI Reduction among Obese Adolescents Attending a Clinical Multidisciplinary Weight Management Program

AimsTo determine whether baseline levels of self-reported sleep and sleep problems among obese adolescents referred to an outpatient multidisciplinary family-based weight management program predict reduction in BMI 3 months later.MethodsA retrospective medical chart review was conducted for 83 obese adolescents. The following baseline variables were extracted: self-reported sleep duration (weekdays and weekends), and presence of snoring, daytime fatigue, suspected sleep apnea, and physician-diagnosed sleep apnea. Anthropometric data at baseline and 3 months were also collected.ResultsOn average, adolescents reported significantly less sleeping on weeknights (7.7 ± 1.3 h) compared to weekend nights (10.0 ± 1.8 h), t(82) = 10.5, p = 0.0001. Reduction in BMI after 3 months of treatment was predicted by more weekly sleep at baseline (R² = 0.113, F(1, 80) = 10.2, p = 0.002). Adolescents who reduced their BMI by ≥1 kg/m² reported greater weekly sleep at baseline compared to adolescents who experienced <1 kg/m² reduction (60.7 ± 7.5 h vs. 56.4 ± 8.6 h; F(1, 80) = 5.7, p = 0.02).ConclusionFindings from this study, though correlational, raise the possibility that increased duration of sleep may be associated with weight loss among obese adolescents enrolled in a weight management program. Evidence-based behavioral techniques to improve sleep hygiene and increase sleep duration should be explored in pediatric weight management settings.Key Words: Obesity, Adolescent, Sleep, Weight loss, Treatment