Journal of Sleep Research最新文献

The aim of this study was to determine whether closed-loop vibration stimulation, delivered at +3% of the heart rate frequency at an imperceptible intensity before waking, could reduce sleep inertia. Participants napped on a bed equipped with a woofer that delivered vibration stimulation every 5 min, starting 30 min before their scheduled wake time. The effects of the stimulation were assessed using a Psychomotor Vigilance Task performed immediately upon waking, along with the analysis of salivary cortisol and melatonin levels, as well as subjective arousal ratings based on the Karolinska Sleepiness Scale and the Stanford Sleepiness Scale. The results indicated that vibration stimulation at +3% of the heart rate frequency improved Psychomotor Vigilance Task reaction times and increased self-reported arousal scores, thus reducing sleep inertia compared with the control condition without stimulation. Additionally, salivary melatonin levels were lower immediately after waking. These findings suggest that closed-loop vibration stimulation at +3% of the heart rate frequency before waking could be an effective method to reduce sleep inertia. This non-invasive approach may facilitate cognitive recovery following sleep. Further research is required to investigate the underlying mechanisms, and confirm these findings across different populations and settings.

A nationwide survey in the USA reported that healthcare workers had the highest prevalence of short sleep duration compared with other professions. Moreover, several studies have reported poor sleep quality among healthcare professionals and described insufficient sleep as a potential driver of reduced physician well-being. This study aims to explore sleep quality and mental health issues among Syrian medical residents, with the goal of informing targeted interventions to enhance their well-being and professional performance. This cross-sectional study in Syria involved 2071 residents from 22 major hospitals. Conducted between 27 October 2023 and 4 April 2024, it used face-to-face interviews with validated questionnaires following STROBE guidelines. Hospitals were categorized for comparative analysis. Measures included demographics, Pittsburgh Sleep Quality Index, Patient Health Questionnaire for depression, and Generalized Anxiety Disorder 7-item. In a study involving 2071 hospital residents across Syria's major hospitals, significant findings reveal a high prevalence of poor sleep quality (67.7%), depressive symptoms (46%) and anxiety symptoms (42.2%). Analysis by hospital categories highlighted varied rates, with Damascus and Hama General Hospitals showing notably higher incidences. Females exhibited higher rates of depressive and anxiety symptoms compared with males, with predictors including gender, age and marital status. The relatively high prevalence of poor sleep quality, depressive symptoms and anxiety symptoms among Syrian medical residents necessitates proper action, which will probably include limits on work hours, to enhance mental health outcomes and ensure proper patient care.

The neuronal ceroid lipofuscinoses (NCLs) are a group of recessively inherited neurodegenerative diseases characterizsed by lysosomal storage of fluorescent materials. CLN3 disease, or juvenile Batten disease, is the most common NCL that is caused by mutations in the Ceroid Lipofuscinosis, Neuronal 3 (CLN3) gene. Sleep disturbances are among the most common symptoms associated with CLN3 disease that deteriorate the patients' life quality, yet this is understudied and has not been delineated in animal models of the disease. The current study utilised PiezoSleep, a non-invasive, automated piezoelectric motion sensing system, to classify sleep and wakefulness in a Cln3^{Δex1-6/Δex1-6} (Cln3KO) mouse model and age- and sex-matched wild-type (WT) controls. The sleep-wake classification by PiezoSleep was found to be about 90% accurate when validated against simultaneous polysomnographic recordings including electroencephalography (EEG) and electromyography (EMG) in a small cohort of WT and Cln3KO mice. Our large cohort PiezoSleep study revealed sleep abnormalities during the light period in male Cln3KO mice compared with WT male mice, and more subtle differences in Cln3KO female mice in the dark period compared with WT female mice. Our characterisation of sleep in the Cln3KO mouse model aligns with sleep abnormalities seen in CLN3 disease patients and serves as a basis to continue examining sleep disturbances commonly reported for CLN3 disease and other NCLs. As the first animal model study capturing sleep disturbances in CLN3 disease, our work will facilitate future studies into the potential mechanism behind sleep disturbances associated with the disease and the potential treatment strategies.

As available treatments in obstructive sleep apnea are all associated with side-effects or adherence problems, there is a need for alternative treatment options. In this randomized, open, parallel-group intervention study, the effect of head extension by cervical collar was evaluated in patients with moderate obstructive sleep apnea. One-hundred patients with moderate obstructive sleep apnea (apneas and hypopneas per estimated hours asleep = respiratory events index: 15-30) were randomized to either lifestyle intervention, or cervical collar in combination with lifestyle intervention. Both groups received lifestyle advice. In addition, the treatment group was treated with a cervical collar, which allows adjustment of head extension, during sleep. Assessment with questionnaires and polygraphy were performed at baseline and after 6 ± 2 weeks. A linear regression model was used to assess a total effect on respiratory events index, which was the primary endpoint. In the intention-to-treat analysis, the cervical collar in combination with lifestyle intervention group decreased their respiratory events index (p = 0.008) and oxygen desaturation index (p = 0.008) more than the lifestyle intervention group, with a mean difference of -4.5 and -4.3, respectively. In the sub-analysis, there was a clear effect on respiratory events index in the supine position (mean difference between the groups -9.1, p = 0.018) but not on non-supine apnea-hypopnea index (-2.3, p = 0.17). We conclude that head extension by cervical collar during sleep resulted in improved respiratory events index and oxygen desaturation index values in patients with moderate obstructive sleep apnea. Cervical collar can be a second-line treatment option in this group, especially in positional obstructive sleep apnea.

Sleep problems are important comorbid features of, and risk factors for, neurodegenerative diseases such as Parkinson's disease (PD). To assess the prevalence and associations of sleep problems in patients with PD we analysed data from almost 54,000 participants in the Fox Insight study, including data from 38,588 patients with PD. Sleep problems are common in PD, with ~84% of respondents with PD reporting difficulty falling or staying asleep. Experiences of insomnia, restless leg syndrome, vivid dreams, acting out dreams, and the use of sleep medication are over-represented in patients with PD compared with matched healthy controls. Male sex and PD onset before the age of 50 were also associated with a greater risk of sleep problems. A physician diagnosis of insomnia was associated with more symptoms of depression, impairment of cognition-dependent independence, and a lower quality of life. Sleep problems were also associated with a higher prevalence of OFF periods compared with PD patients without sleep problems. 6.7% of PD patients endorsed sleep complaints as their most bothersome symptom, and reported non-specific poor sleep quality as the most common sleep problem. These patients also had a better quality of life and lower depression and cognitive impairments than patients for whom postural instability was their most bothersome symptom, indicating the relative burden of sleep problems is contextualised by the severity of motor symptoms. Overall, these findings reinforce the high prevalence of sleep problems in a very large sample of PD patients, and indicate important associations of sleep problems with daily function and quality of life in PD.

Delayed sleep-wake phase disorder involves chronic difficulty going to bed and waking up at conventional times and often co-occurs with depression. This study compared sleep and circadian rhythms between patients with delayed sleep-wake phase disorder with depression (DSWPD-D) and without (DSWPD-ND) comorbid depression. Clinical records of 162 patients with delayed sleep-wake phase disorder (70 DSWPD-D, 92 DSWPD-ND) were analysed, including a subset of 76 patients with circadian phase determined by the dim light melatonin onset. Variables assessed included sleep behaviour on work and free days, weekly sleep duration, social jet lag, chronotype, and phase relationships between dim light melatonin onset and sleep/wake times. Mean (SD) or median [Q1-Q3] values were compared using t-tests or Mann-Whitney. Patients with DSWPD-D showed longer sleep on workdays (DSWPD-D = 7.63 hr [1.70] versus DSWPD-ND = 6.20 hr [1.59]; p < 0.001), but not on free days. DSWPD-D also showed later sleep onset (DSWPD-D = 03:30 14;hours [02:49 hours-04:23 hours], DSWPD-ND = 02:53 hours [02:00 hours-03:41 hours]; p = 0.02) and wake times (DSWPD-D = 11:30 hours [09:30 hours-13:00 hours], DSWPD-ND = 08:45 hours [07:20 hours-11:00 hours]; p < 0.01) on workdays. Furthermore, DSWPD-D showed less social jet lag (DSWPD-D = 0.38 [0.00-1.75] versus DSWPD-ND = 2.17 [1.25-3.03]; p < 0.01), and reported higher anxiety symptoms (DSWPD-D = 71.4% versus DSWPD-ND = 45.8%; p = 0.03) and medication use (DSWPD-D = 75.0% versus DSWPD-ND = 43.8%; p = 0.01). DSWPD-D also showed wider dim light melatonin onset phase relationships with dim light melatonin onset-mid-sleep (DSWPD-D = -5.77 [1.32] versus DSWPD-ND = -4.86 [1.53]; p = 0.01) and dim light melatonin onset-waketime (DSWPD-D = -9.46 [1.82]; DSWPD-ND = -8.13 [2.08]; p = 0.01). Multivariable Poisson regression, adjusted for age and sex, showed more medication use, less social jet lag, and longer weekly sleep duration as significantly associated with DSWPD-D. These findings suggest potential biopsychosocial protective factors linked to depression in delayed sleep-wake phase disorder. Further research is required to confirm these phenotypic differences and their relevance to delayed sleep-wake phase disorder aetiology and treatment.

Changes in social zeitgebers across the lifespan affect the interaction between biological and social clocks, potentially contributing to social jetlag. Extant literature suggests a reduction in social jetlag given declining social obligations occurring after retirement, but is limited to self-reported methods and cross-sectional designs. Leveraging longitudinal and ecologically valid data from consumer sleep technology, we analysed objective sleep data from 2439 users of the polysomnography-validated SleepScore mobile application, encompassing 500,415 total nights recorded. We examined the relationship between age as a continuous variable, age as a proxy for retirement status, and social jetlag. Additional linear models were employed to assess the effect of self-reported chronotype, average reported daily caffeine, alcohol and stress on social jetlag. There was a significant negative association between overall age and social jetlag (β = -0.64, t = -9.90, p < 0.001, effect size = 0.040), such that every 1-year increase in age corresponded with a 0.64-min reduction in social jetlag. The inclusion of self-reported chronotype, stress, caffeine and alcohol increased the explanatory power of our models slightly, but the effect of age remained consistent (β = -0.642, t = -8.91, p < 0.001, effect size = 0.046). Retirement-aged individuals exhibited nearly 50% less reduction in social jetlag than pre-retirement (30.6 ± 48.2 min versus post-retirement: 15.8 ± 41.6 min, p < 0.0001). While social jetlag after retirement was most pronounced for strong evening chronotypes (β = -0.41, t = -2.876, p = 0.004, effect size = -0.4276), pairwise comparisons revealed no statistically significant differences in the slopes between chronotypes (p > 0.05). Thus, jetlag decreases across the lifespan, and its reduction appears to be amplified post-retirement even after accounting for behavioural factors.

Literature evidenced an association of maternal sleep disturbances and maternal obstructive sleep apnea with significant obstetric complications. Moreover, the maternal sleep disturbances effect on feto-placental circulation had not been extensively examined. Our objective is to explore the possible maternal sleep disturbances impact on the feto-placental indices evaluated through the Doppler study. A systematic review of the following databases was performed: PubMed, EMBASE, Cochrane Library and Google Scholar from the beginning to June 2024. Only studies that enrolled pregnant women with signs and symptoms of maternal sleep disturbances or obstructive sleep apnea diagnosis, which analysed the feto-placental Doppler parameters, were considered eligible (PROSPERO ID: CRD42024553926). We included a total of four studies with 1715 cases of pregnant women. Various instrumental and non-instrumental diagnostic methods were adopted for detection of maternal sleep disturbances. The ultrasound exam was performed mainly in the third trimester of pregnancies, and all the studies explored the uterine Doppler parameters. Only two studies explore the foetal Doppler parameters. Only one study disclosed that maternal sleep disturbances are related to altered uterine Doppler indices with probable placental dysfunction. This review did not evidence a significant influence of maternal sleep disturbances and obstructive sleep apnea on foetal Doppler indices. Moreover, one large prospective study showed a possible impact of maternal sleep disturbances on uterine Doppler with a potential impairment of the placentation function. Additional studies with detailed data and larger samples are needed to throw light on this relationship and its impact on the foetal outcomes.

Sleepiness-related errors are a leading cause of driving accidents, requiring drivers to effectively monitor sleepiness levels. However, there are inter-individual differences in driving performance after sleep loss, with some showing poor driving performance while others show minimal impairment. This research explored if there are differences in self-reported sleepiness and driving performance in healthy drivers who exhibited vulnerability or resistance to objective driving impairment following extended wakefulness. Thirty-two adults (female = 18, mean age = 33.0 ± 14.6 years) completed five × 60-min simulated drives across 29-hr of extended wakefulness. Subjective sleepiness (Karolinska Sleepiness Scale) and subjective driving performance ratings (nine-point Likert scale) were assessed at 10-min intervals while driving. Cluster analysis using simulator steering deviation and crash data categorised participants as vulnerable (n = 16) or resistant (n = 16) to driving impairments following extended wakefulness. No differences in self-ratings between the vulnerable and resistant groups were observed except during the last drive (25 hr awake), where the vulnerable group reported higher sleepiness (p = 0.008) and worse driving performance (p = 0.001) than the resistant group. For each 1-point increase on the Karolinska Sleepiness Scale and subjective driving scales, the vulnerable group showed about threefold greater steering impairment relative to resistant drivers. Although self-reported sleepiness and driving performance were correlated with objective driving performance, vulnerable drivers reported similar sleepiness and driving performance as resistant drivers. Thus, self-reported sleepiness and driving performance are not reliably sensitive to sleep loss effects on objective driving performance, which may impact the vulnerable driver's decisions to continue driving and delay engagement in countermeasures to reduce crash risk (e.g. napping), warranting further research.

The '6-h on/6-h off' shift pattern could potentially disrupt the physiological rhythms and cognitive performance of seafarers, attributed to its shorter and more frequent shifts. Conversely, light exposure has been demonstrated to enhance cognitive abilities and synchronise physiological processes. Therefore, we studied the fatigue, cognition, sleep and rhythm of seafarers with different shifts to determine how light can benefit their performance. A total of 16 seafarers participated in a 2 × 2 crossover study, which involved two shift types (Morning-Evening and Day-Night) and two lighting conditions (static lighting and dynamic lighting). Sleepiness, cognition and fatigue were assessed every 2 h during '6-h on' period, using the Karolinska Sleepiness Scale, psychomotor vigilance task, critical flicker frequency and visual analogue scale for fatigue. Sleep was monitored during '6-h off' period, core body temperature was continuously tracked for rhythm throughout the shift protocol. For the Day-Night shift, the static mode with stable higher illuminance than dynamic lighting significantly reduced sleepiness (p = 0.01), objective fatigue (p = 0.001), subjective fatigue (fatigue level [p = 0.004] and visual fatigue [p = 0.001]) during the night period, while increasing sleep duration during the day (6:00 a.m. to 12:00 p.m.) and delaying the rhythm. For the Morning-Evening shift, dynamic lighting with lower illuminance significantly increased sleep duration during the night (12:00 a.m. to 6:00 a.m.) without causing a significant difference in performance. Overall, static lighting is more suitable for Day-Night shift seafarers due to lower sleepiness, fatigue and longer daytime sleep duration, while dynamic lighting is more suitable for Morning-Evening shift seafarers due to longer night-time sleep duration. Therefore, different lighting patterns should be adopted for seafarers during different shifts.