Sleep advances : a journal of the Sleep Research Society最新文献

Study objectives: To assess the performance of a portable electroencephalography device for sleep monitoring against polysomnography.

Method: Fifty-six adults underwent one night of in-laboratory sleep recording with the Muse-S headband and simultaneous level 1 polysomnography. Muse-S data were scored by an automated sleep staging algorithm. A registered technologist, blind to the Muse-S automated sleep scoring, scored the polysomnography data.

Results: Good quality data were available for 47 (84 per cent) participants (53 per cent females; 20-71 years old; 17 per cent with sleep-related breathing disorder). Epoch-by-epoch analyses showed substantial agreement between the Muse-S and polysomnography (full night Cohen's Kappa = 0.76). Cohen's Kappa were in the fair agreement range for non-rapid eye movement (NREM) 1, substantial agreement range for NREM2 and NREM3, and near-perfect agreement range for rapid eye movement sleep and wake. Accuracy ranged from 88 per cent to 96 per cent across all sleep stages, with a sensitivity of 79-92 per cent and a specificity of 90-99 per cent. Similar results were observed in the subgroup with sleep-related breathing disorder. On average, the Muse-S had higher mean values than polysomnography for total sleep time (+6 min), NREM3 (+15 min), rapid eye movement sleep (+6 min), and sleep efficiency (+1.5 per cent), and lower mean values for sleep latency (-3 min), wake after sleep onset (-3 min), and light sleep (-14 min).

Conclusions: When compared to standard polysomnography, the Muse-S performed well to measure sleep macroarchitecture. This portable device shows great potential as an accessible tool for sleep electroencephalography monitoring. More work is required to validate this tool in more diverse populations to ensure robustness across age, sex, neurological conditions, and sleep profiles.This article is part of the Consumer Sleep Technology Special Collection.

Traumatic brain injury (TBI) is associated with sleep disturbances and cognitive impairment, with limited effective therapeutic strategies. Our previous work showed dietary supplementation with branched chain amino acids (BCAAs; isoleucine, leucine, valine), the primary substrate for de novo glutamate/GABA synthesis in the CNS, restored normal sleep-wake patterns and improved cognitive function in rodents. Our recent pilot work in humans showed preliminary feasibility/acceptability and limited efficacy for BCAAs to improve sleep in Veterans with TBI. However, these pilot data were limited in sample size, treatment dosages/duration, and therefore unable to establish efficacy or provide insight into dosing/duration parameters. The present study, SmART-TBI (supplementation with amino acid rehabilitative therapy in TBI: NCT04603443), represents a placebo-controlled, double-masked randomized clinical trial (target n = 120). Covariate adaptive randomization controlling for age, sex, TBI recency, pain, depression, and PTSD, allocated participants 1:1:1:1 to four groups comprising 3 BCAA doses b.i.d. ("high" 30 g; "medium" 20 g; and "low" 10 g) and one placebo-control (rice protein, 10 g b.i.d.). Outcomes were assessed following a 2-week baseline period; after 4 weeks, 8 weeks, and 12 weeks of intervention; and after 4 weeks and 12 weeks post-intervention. The primary outcomes are overall feasibility/acceptability metrics, and secondarily, preliminary efficacy for BCAAs to improve subjective sleep as assessed by the Insomnia Severity Index. Additional sleep measures were obtained for future analyses using a combination of actigraphy, mattress-sensors, sleep diaries, as well as pre-/post-BCAA overnight polysomnography. Additional exploratory outcomes included sweat-based biomarkers. Analyses of primary outcome measures indicated high feasibility and acceptability for this fully protocol.

Study objectives: Millions of Americans obtain insufficient sleep daily, yet it is unknown the relationship between sleep and life expectancy by county across the United States.

Methods: Using the 2019-2025 Centers for Disease Control and Prevention Behavioral Risk Factor Surveillance System surveys, we tested the associations between insufficient sleep and life expectancy at the county level while controlling for common adverse health behaviors (i.e. smoking, diet, and inactivity) across multiple years (2019-2025).

Results: Insufficient sleep was significantly negatively correlated with life expectancy in most states from 2019 to 2025, such that lower sleep insufficiency was associated with longer life expectancy. Moreover, sleep insufficiency was significantly associated with lower life expectancy when controlling for traditional predictors of mortality, with only smoking displaying a stronger association.

Conclusions: These findings demonstrate the importance of adequate sleep in all communities regardless of income level, access to health care services, or geographical classification.

Study objectives: Evaluate the effect and safety of alpha rhythm-guided repetitive transcranial magnetic stimulation (α-rTMS) on sleep difficulties in children with autism spectrum disorder (ASD).

Methods: Twenty children (6-12 years old; 16 males; 4 females) with ASD level 2 were randomly assigned (1:1 ratio) to a treatment group (TG) or a waitlist control group (WLCG) (T1). The TG received ten α-rTMS sessions over two weeks, while the WLCG acted as control for that period (T2). Next, the WLCG received α-rTMS for two weeks (T3). All study participants were followed up at one (T4) and four (T5) months. Sleep difficulties were measured using the Children's Sleep Habit Questionnaire (CSHQ), Actigraphy, and Polysomnography (PSG).

Results: Group-by-time interactions indicated that the TG had greater improvements than the WLCG in total CSHQ score (p=.008) and, bedtime resistance (p=.003), sleep onset delay (p=.004), and sleep duration (p=.003) subdomain scores. When the WLCG received the α-rTMS, there were improvements in their sleep-disordered breathing (p=.001), parasomnia (p=.002) and sleep duration (p=.018) subdomain scores, while PSG data showed improved Waking After Sleep Onset (WASO) (p=.014), Sleep efficiency (p=.046), and N2 stage (p=.039). The improved CSHQ scores persisted, with actigraphy data showing significant improvement in WASO at T4 and T5. Side effects of α-rTMS were mild and transient.

Conclusions: This RCT study presents preliminary evidence on the effect and safety of α-rTMS in improving subjective sleep difficulties in children with ASD, with effects lasting up to four months post-intervention. Further studies using a larger sample size and sham-controlled group are warranted.

Clinical trial registration: The trial was registered on July 11, 2023 within the Australian New Zealand Clinical Trials Registry (ANZCTR) https://www.anzctr.org.au/TrialSearch.aspx with registration number: ACTRN12623000757617.

Study objectives: Isolated REM sleep without atonia (iRSWA) is increasingly detected on polysomnography (PSG), yet its clinical relevance remains unclear. We compared the demographic profile, sleep physiology, comorbidities, and longitudinal outcomes of people with iRSWA and isolated REM sleep behaviour disorder (iRBD).

Methods: We retrospectively reviewed PSG reports (2008-2022) from a tertiary sleep-medicine center, classifying people as iRSWA or iRBD based on self-reported dream-enactment behavior. Clinical data were extracted from charts, and PSG variables from sleep reports. Neurological and psychiatric diagnoses before the sleep examination were obtained from national registries. Comparisons used multivariable regression and Fine-Gray competing-risk models.

Results: The cohort comprised 302 participants (iRSWA = 98 and iRBD = 204). Participants with iRSWA were more often female (38.8% vs 23%, p = .004), with a younger age distribution (35-49 years; 25.5% vs 13.7%, p = .015). They reported more daytime sleepiness/fatigue (odds ratio [OR] 2.84, p < .001) despite comparable objective sleep architecture. Objective neurodegenerative signs appeared only in the iRBD group. Pre-index neurological disorders were more common in iRSWA (31.6% vs 19.1%, p = .042), while neurodegenerative conversion during follow-up occurred in 4.1 per cent of iRSWA and 8.8 per cent of iRBD. In multivariable analysis, sleepiness/fatigue and pre-existing neurological disorder were associated with iRSWA; when spouse status was included in the model, spouse status became the strongest predictor, periodic limb movements in sleep of 15 or more reached significance, and the association with sex attenuated.

Conclusions: iRSWA differs from iRBD in profile and pre-index comorbidity patterns. Our findings support the view that iRSWA may reflect mechanisms other than a uniform prodromal stage of α-synucleinopathy.

Study objectives: Sleep spindles are potential biomarkers for memory decline in aging. However, significant within-person variability in spindle attributes complicates their utility in predicting cognitive deterioration. This study aimed to uncover distinct spindle types and their relevance to memory decline using exploratory, data-driven clustering.

Methods: Polysomnography was collected from younger (n = 43, ages 20-45 years) and older cognitively healthy adults (n = 34, ages 60-81 years). Clustering analysis was performed using multiple features and spatiotemporal context, irrespective of participant age.

Results: Resulting clusters were hierarchically defined by the sleep stage, slow oscillation concurrence, and hemisphere. Stage N3 spindles (15%; predominantly coinciding with slow oscillations) formed a distinct group, followed by N2 spindles coinciding with slow oscillations (27%). Remaining N2 spindles were categorized into unilateral (41%) and bilateral clusters (17%). In older adults, there was a lower proportion of N2 bilateral spindles and a higher proportion of N2 spindles concurrent with slow oscillations. Lower proportion of N2 bilateral spindles was associated with better composite memory performance in younger adults, whereas higher spindle power, regardless of cluster belonging, was associated with reduced memory benefit from sleep compared with wakefulness.

Conclusions: Our results indicate differing expression of spatiotemporal spindle clusters in older age, as well as intertwined dynamics between spindle propagation, slow oscillation concurrence, and frequency shifts in aging. In addition, spindle heterogeneity aligned with global sleep stage dynamics. These results emphasize the interconnectedness of spindle activity with overall sleep patterns, underscoring the importance of spatiotemporal context within and across sleep stages.

Integrated alongside home-based passive sleep monitoring, high-frequency assessment of patient reported outcomes (PROs) could enhance both research and clinical care surrounding obstructive sleep apnea (OSA). However, traditional approaches to capturing OSA-related PROs are poorly suited for this purpose. Hence, we investigated the feasibility of a smartphone-based check-in approach to monitor daily PROs (e.g. mental, emotional, and physical) over a 6-month period in people referred for suspected OSA. We quantified and assessed change in the proportion of participants (n = 68; 54% female) who, on average, achieved an "adequate" self-report rate of ≥4 self-reports per week (out of a possible seven). Generalized additive models (GAMs) were used to investigate if OSA severity (apnea-hypopnea index; AHI) was associated with the probability of adequate initial uptake within the first two weeks, sustained engagement over time, and the probability of a self-report on any given day. Self-reports were made on 52.1% of all possible days, equating to (M ± SD) 3.6 ± 3.0 per week. Within the first week, 63.2% of participants achieved "adequate" self-report compliance; during weeks 4 and 12, these rates were 70.6% and 54.4% , respectively. Greater baseline AHI was associated with slower time-dependent decline in the probability of adequate self-report compliance in an exposure-response manner. Within-subjects, daily self-reports were more probable following nights of elevated AHI (absolute and mean-referenced). All GAM smooth terms: p < .00001. Findings demonstrate the feasibility of bi-daily PRO assessment via app-based check-ins for approximately 1 month in the context of clinical OSA and suggest that greater disease burden enhances sustained engagement with this monitoring approach. This paper is part of the Consumer Sleep Technology Collection.

Musical chords represent the most basic musical elements, conveying emotional information. During wakefulness, different musical chord categories elicit distinct neuronal correlates and emotions, with major chords typically inducing more positive and minor chords negative ones. However, it remains unclear whether the brain continues to process musical chords differently when presented during sleep. To address this question, we conducted a proof-of-concept study and presented musical major, minor, and dissonant chords to 47 healthy participants during nocturnal non-rapid eye movement sleep. Prior to sleep, participants rated the chords in valence and arousal. Sleep was recorded using polysomnography. Our analysis of event-related responses during sleep revealed significant differences between the three musical chord categories. Major chords induced the strongest negative amplitude approximately 800 ms after chord onset, indicated as peak-to-peak (PTP) amplitude from the earlier positive peak. Minor chords showed intermediate PTP amplitudes, while dissonant chords elicited the lowest PTP amplitudes. In the time-frequency domain, these differences were also apparent, including differences in slow-wave, theta, alpha, and sleep spindle bands across chord categories. Notably, experience in playing a musical instrument induced stronger differentiation of musical harmony during sleep compared with participants who never played a musical instrument. In conclusion, our findings suggest that the different processing of single musical chords persists during sleep, influenced by harmonic features and musical expertise in the context of Western musical conventions. Future research should explore whether longer and more complex harmonic features (e.g. chord sequences or musical pieces) are differentially processed by the sleeping brain.

Study objectives: Sleep irregularity is associated with elevated blood pressure (BP). Whether sleep regularity decreases BP is not known. We hypothesized that an intervention involving 2 weeks of sleep regularization would decrease BP in people with hypertension.

Methods: Eleven people with hypertension (four males/seven females, age: mean 53 [range 45-62 years]), body mass index (32 ± 6 kg/m²), but no other chronic disease were studied. We measured ambulatory BP and assessed sleep using actigraphy over a free-living baseline week. For the next 2 weeks, participants were asked to go to bed at the same time every night before reassessing their ambulatory BP. The standard deviations of bedtimes and sleep onset were used to measure variability. The minimal detectable change (MDC) in BP was calculated from 48 h of ambulatory BP monitoring to analyze individual responses.

Results: Bedtime variability (32.4 ± SD 17 vs. 7 ± 10 min, p = .001) and sleep onset variability (30 ± 17 vs. 7 ± 8 min, p = .011) decreased following the intervention; no other sleep parameters changed. Bedtime regularization significantly reduced 24-h systolic BP (-4 ± 4 mmHg) and diastolic BP (-3 ± 3 mmHg), mainly due to reduced nighttime systolic BP (-5 ± 7 mmHg) and diastolic BP (-4 ± 5 mmHg), all p < .05. ≥50 per cent of participants decreased their BP by more than the MDC₉₅ for 24-h BP.

Conclusions: In this proof-of-concept study, 2 weeks of bedtime regularization decreased 24-h and nighttime BP in people with hypertension, suggesting that this may be a simple, yet low-risk, adjunctive strategy to control BP in many people with hypertension. This ought to be tested in a larger randomized controlled trial.

Insomnia is increasingly recognized as a public health concern; however, undergraduate university students remain relatively understudied. This study aimed to estimate the overall pooled prevalence of insomnia symptoms in this population to inform the need for targeted care. For this systematic review and meta-analysis, we searched five databases to identify papers published between January 1, 1993, and January 17, 2025, which investigated the prevalence or proportion of insomnia in undergraduate university students using validated measures. Studies with biased samples were excluded. Study quality was assessed using the Joanna Briggs Institute Critical Appraisal Tool. Data were synthesized using random-effects meta-analysis and meta-regression. Subgroup analyses were conducted based on continent, screening instrument, field of study, and sampling method. The review was registered on PROSPERO (CRD42025617914). The search yielded 2379 non-duplicate citations, of which 48 met the inclusion criteria, contributing 55 prevalence estimates based on data from 95 938 students. The pooled prevalence of insomnia in undergraduate university students was 46.9% (95% CI = 40.1% to 53.6%). Heterogeneity was high (I ² = 99.8%). Meta-regression indicated that rates varied by continent and screening instrument. Findings suggest that nearly half of undergraduate students experience insomnia symptoms, highlighting the need for university-level responses that combine universal sleep health promotion with targeted interventions. Further methodologically rigorous and culturally sensitive research is required to guide policy and practice.