Objective Sleep Quality Research Articles

Dose and timing effects of caffeine on subsequent sleep: A randomised clinical crossover trial.

To investigate the effect of a typical dose of caffeine and a high dose of caffeine consumed in the morning, afternoon, and evening on subsequent sleep. Using a placebo-controlled, double-blind, randomised crossover design, 23 males (25.3±5.0 years) with a moderate habitual caffeine intake (<300mg∙day-1) completed seven conditions: placebo, and 100 and 400mg of caffeine consumed 12, eight, and four hours prior to bedtime, with a 48-hour washout. In-home partial polysomnography and sleep diaries were used to assess sleep. Linear mixed models estimated the effect of each condition. No significant effect on objective or subjective sleep occurred with the 100mg dose of caffeine compared to the placebo (p>0.05) but significant effects occurred with the 400mg dose (p<0.05). Significant delays in sleep initiation and alterations to sleep architecture were observed when 400mg was consumed within 12 hours of bedtime (p<0.05), and significantly greater sleep fragmentation occurred when 400mg was consumed within eight hours of bedtime (p<0.05). Additionally, perceived sleep quality was significantly reduced when 400mg was consumed four hours prior to bedtime (-34.02%, p=.006) but not at eight or 12 hours. A 100mg dose of caffeine can be consumed up to four hours prior to bedtime, but 400mg may negatively impact sleep when consumed as one dose within 12 hours of bedtime, with the adverse influence on sleep increasing the closer consumption occurs to bedtime. The discrepancy between objective and subjective sleep quality suggests individuals may have difficulty accurately perceiving the influence of caffeine on sleep quality.

The Abnormal N-Acetylaspartate to Creatine Ratio of the Right Putamen is Linked to Wakefulness in Patients with Insomnia Disorder.

Converging evidence implicates the putamen in sleep-wake regulation. However, its role remains unclear. We hypothesized that metabolic abnormalities in the putamen are linked to insomnia disorder, which has not been previously addressed, and investigated putaminal N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) in patients with insomnia disorder compared to healthy controls. In the present study, the concentrations of NAA, Cho, and Cr in the putamen of 23 patients with insomnia disorder and 18 healthy controls were determined using proton magnetic resonance spectroscopy. Sociodemographic, psychometric, and polysomnography data were obtained from all participants. We found that the mean NAA/Cr ratio of the right putamen was significantly greater in the insomnia group compared to the control group and also greater than the left putamen within the insomnia group. The NAA/Cr ratio of the right putamen distinguished insomnia disorder from normal sleep with 78.3% sensitivity and 61.1% specificity. Furthermore, this ratio positively correlated with both objective and subjective insomnia severity and sleep quality. Our findings provide critical evidence for the dysfunctional putaminal metabolism of NAA/Cr in insomnia disorder, suggesting that the abnormal NAA/Cr ratio of the right putamen is linked to wakefulness in patients with insomnia disorder and may serve as a potential biomarker of insomnia disorder.

Subjective and objective sleep quality assessment in adolescent patients with inflammatory bowel disease

ObjectivesThere is a link between inflammatory bowel disease (IBD) and poor sleep quality that is presumed to be multifactorial. The purpose of this study was to identify factors that impact sleep quality in this group including clinical disease activity, depression, anxiety, quality of life, and disordered social media use through questionnaires. MethodsThis prospective study analyzed sleep quality in adolescent patients ages 13 to 18 with a diagnosis of IBD using objective data from wrist actigraphy and subjective report from the Pittsburgh Sleep Quality Index (PSQI). Additional screeners including the Short Pediatric Crohn's Disease Activity Index or Pediatric Ulcerative Colitis Activity Index, Pediatric Quality of Life Inventory Gastrointestinal Symptoms Module, Generalized Anxiety Disorder 7-item screener, Patient Health Questionnaire depression screener, and Social Media Disorder scale were also collected. ResultsTwenty-three subjects enrolled and 16 completed questionnaires. 62.5 % of participants were in clinical remission and the remaining 37.5 % had mild to severe clinical IBD activity. Poor subjective sleep quality was associated with a shorter duration of sleep time and an increased clinical disease activity score. Patients in clinical remission slept for a longer duration than those with mild IBD activity. ConclusionsThis study did not identify a significant relationship between sleep quality and psychosocial factors in the adolescent population with IBD, though their influence cannot be discounted. There was a connection between the presence of disease activity and shorter sleep duration. Similarly, PSQI scores correlated with sleep time but not sleep quality.

Sleep quality and the cortisol and alpha-amylase awakening responses in adolescents with depressive disorders.

Depressive disorders in adolescents affect all aspects of life and impose a very large burden of disease. Sleep is frequently affected by depression and is crucial for facing challenges during development. One of the postulated reasons for depression-induced sleep disruption is dysregulation of the physiological stress system. To investigate the links of adolescent depressive disorders with subjective sleep quality, objective sleep quality, and the course of cortisol and alpha-amylase after awakening. We compared subjective sleep quality (via daily questionnaires) and objective sleep quality (via actigraphy measurement) of 35 adolescents with depressive disorders and 29 healthy controls over 7 consecutive days. In addition, saliva samples were collected on 3 days to examine cortisol and alpha-amylase patterns after awakening. No significant differences in cortisol or alpha-amylase awakening responses were observed between participants with depressive disorders and healthy controls. We found severe reductions in subjective sleep quality in the depression group (Z = -5.19, P < 0.001, d = 1.80) and a prolonged actigraphy-measured sleep onset latency (Z = -2.42, P = 0.015, d = 0.64) compared with controls. Reductions in subjective sleep quality were partially correlated with objective sleep measures (sleep onset latency: r = -0.270, P = 0.004, sleep efficiency: r = 0.215, P = 0.017). Sleep onset latency seems to aggravate depressive symptoms and to have an important role in perception of sleep quality. Adolescents with depressive disorders should be supported regarding the establishment of good sleep hygiene and avoiding activities that may impede falling asleep.

Older adults exercising ON TIME: protocol for a randomized controlled cross-over study to assess the effect of physical activity timing on insomnia severity

BackgroundThere are increased indications that physical activity timing, irrespective of intensity, impacts insomnia and circadian clock function. Here, we describe the rationale and design of a randomized cross-over study, called ON TIME, to examine the effects of (changing) physical activity timing on insomnia severity and on multiple exploratory outcomes that are linked to circadian clock function.MethodsWe will conduct a randomized cross-over trial in 40 healthy older adults (aged 65 to 75 years) with subclinical or clinical insomnia (Insomnia Severity Index (ISI) scores of ≥ 10) from the Dutch municipality of Leiden and surroundings. Participants will undergo 3 intervention periods (14 days each) consecutively: one sedentary period and two periods of increased physical activity (one period with morning activity and one period with evening activity). The intervention periods are separated by a wash-out period of 1 week. In both active intervention arms, participants will follow coached or uncoached outdoor physical exercise sessions comprising endurance, strength, and flexibility exercises for 14 days. The primary outcome is change in insomnia severity as measured by the ISI. Additional exploratory outcomes include multiple components of objective sleep quality measured with tri-axial accelerometry and subjective sleep quality assessed by questionnaires as well as dim light melatonin onset and 24-h rhythms in heart rate, heart rate variability, breathing rate, oxygen saturation, mood, and objective emotional arousal and stress. Additionally, we will collect diary data on eating patterns (timing and composition). Finally, fasting blood samples will be collected at baseline and after each intervention period for measurements of biomarkers of metabolic and physiological functioning and expression of genes involved in regulation of the biological clock.DiscussionWe anticipate that this study will make a significant contribution to the limited knowledge on the effect of physical activity timing. Optimizing physical activity timing has the potential to augment the health benefits of increased physical exercise in the aging population.Trial registrationTrial was approved by the Medical Ethics Committee Leiden, The Hague, Delft, The Netherlands (June, 2023). The trial was registered in the CCMO-register https://www.toetsingonline.nl/to/ccmo_search.nsf/Searchform?OpenForm under study ID NL82335.058.22 and named (“Ouderen op tijd in beweging” or in English “Older adults exercising on time”). At time of manuscript submission, the trial was additionally registered at ClinicalTrials.gov under study ID: NL82335.058.22 and is awaiting approval.

Predicting Sleep Quality through Biofeedback: A Machine Learning Approach Using Heart Rate Variability and Skin Temperature.

Sleep quality (SQ) is a crucial aspect of overall health. Poor sleep quality may cause cognitive impairment, mood disturbances, and an increased risk of chronic diseases. Therefore, assessing sleep quality helps identify individuals at risk and develop effective interventions. SQ has been demonstrated to affect heart rate variability (HRV) and skin temperature even during wakefulness. In this perspective, using wearables and contactless technologies to continuously monitor HR and skin temperature is highly suited for assessing objective SQ. However, studies modeling the relationship linking HRV and skin temperature metrics evaluated during wakefulness to predict SQ are lacking. This study aims to develop machine learning models based on HRV and skin temperature that estimate SQ as assessed by the Pittsburgh Sleep Quality Index (PSQI). HRV was measured with a wearable sensor, and facial skin temperature was measured by infrared thermal imaging. Classification models based on unimodal and multimodal HRV and skin temperature were developed. A Support Vector Machine applied to multimodal HRV and skin temperature delivered the best classification accuracy, 83.4%. This study can pave the way for the employment of wearable and contactless technologies to monitor SQ for ergonomic applications. The proposed method significantly advances the field by achieving a higher classification accuracy than existing state-of-the-art methods. Our multimodal approach leverages the synergistic effects of HRV and skin temperature metrics, thus providing a more comprehensive assessment of SQ. Quantitative performance indicators, such as the 83.4% classification accuracy, underscore the robustness and potential of our method in accurately predicting sleep quality using non-intrusive measurements taken during wakefulness.

Perceived Stress, but Not Rumination, Mediates the Relationship Between Trait Mindfulness and Sleep Quality in Young Adults.

Poor sleep among young adults is prevalent, yet the mediating variables are largely understudied, and there is limited relevant work utilizing objective sleep measures. The present study investigated the mediating effects of perceived stress and rumination in the relationship between trait mindfulness and subjective and objective sleep quality in young adults. A total of 170 healthy adults (aged 18-37, M = 20.8, SD = 2.9) self-reported on trait mindfulness, perceived stress, and rumination. The primary (N = 140) and secondary (N = 30) samples both completed the Pittsburgh Sleep Quality Index (PSQI) to assess subjective sleep quality. The secondary sample (N = 30) additionally provided sleep diaries, as well as wrist-worn actigraphy data for assessing objective sleep quality. A mediation analysis was conducted to assess the effect of trait mindfulness on sleep quality with perceived stress and rumination as mediators. Trait mindfulness was positively associated with better subjective sleep quality; this was fully mediated by perceived stress, b = -0.08, 95% CI [-.12, -0.06]. Rumination was negatively associated with subjective sleep quality but did not mediate the relationship between trait mindfulness and sleep quality, b = -0.01, 95% CI [-.03, 0.02]. Only trait mindfulness was correlated with diary-based sleep ratings, and none of the measures were associated with actigraphy-based sleep quality. This study indicates that perceived stress is an important mediator in the relationship between trait mindfulness and subjective sleep quality among young adults, rather than rumination. These findings have implications for mindfulness-based therapeutic approaches to address the high prevalence of sleep disorders among young adults, adding mechanistic detail to the literature.

The impact of forced awakening on morning blood pressure surge

BackgroundPoor sleep quality can cause an increase in morning blood pressure surge (MBPS), an independent risk factor of cardiovascular disease (CVD) events. Awakening induced by external factors such as alarm clocks, may also contribute to increased MBPS. ObjectivesTo (1) compare the MBPS and sleep quality parameters between natural and forced awakenings and (2) examine the potential impact of forced awakening on MBPS, independent of sleep quality. MethodsThirty-two healthy adults participated in this pilot study, which included one night of natural awakening and one night of forced awakening (i.e., sleep was interrupted by an alarm after five hours). Objective and self-reported sleep quality parameters were measured using a multisensory wristband and sleep diaries, respectively, and beat-to-beat blood pressure variability was assessed using a continuous blood pressure monitor. Analyses included a paired t-test (objective 1) and linear mixed models (objective 2). ResultsParticipants predominantly consisted of young, healthy, and highly educated Asian adults. During the night of sleep with forced awakening, significantly higher MBPS, lower objective wakefulness after sleep onset, and lower self-reported sleep latency were observed, compared to the night with natural awakening. Forced awakening was significantly associated with increased MBPS after controlling for age, sex, mean arterial pressure, and sleep quality. ConclusionsForced awakening may significantly increase MBPS, consequently heightening the risk of CVD events. Study findings should be validated in a larger sample. Further research is also warranted to examine the impact of forced awakening on MBPS in individuals with CVD.

Assessment of sleep quality in patients with orofacial pain and headache complaints: A polysomnographic study.

Sleep is a physiological function essential for survival, recovery, tissue repair, memory consolidation, and brain function. Pain is also an indispensable aspect of human life. The coexistence of sleep disorders and pain is often described in the literature, yet it is critical to define sleep not only subjectively but also using objective instrumental methods, such as polysomnography, that provide data on sleep quality. The aim of the study was to determine the relationship between orofacial pain (OFP), headache (HA) and sleep quality using subjective and objective sleep quality assessment methods. Additionally, we aimed to explore whether poor sleep quality was related to OFP and HA alone or was influenced by the coexistence of psycho-emotional factors such as depression, anxiety and stress. A single-night video-polysomnography was performed on patients from the Outpatient Clinic for Temporomandibular Disorders at Wroclaw Medical University, Poland, who had been diagnosed with OFP and HA. Additionally, questionnaires were employed to assess sleep quality, pain, HA, and the psycho-emotional state. There was no statistically significant relationship between the severity of OFP and HA and polysomnographic sleep quality parameters. On the other hand, the quality of sleep as determined by questionnaire studies correlated markedly with the severity of experienced pain. The severity of pain was found to be significantly correlated with depression, anxiety and perceived stress scores. The psycho-emotional aspects are of critical importance in the perception of OFP and HA. They can be associated with worsened subjective sleep quality, insomnia or daytime sleepiness. Therefore, the treatment of such patients must be preceded by a comprehensive assessment of their psychoemotional state, as anxiety, stress and depression can significantly influence the course of the disease and the response to treatment procedures.

Moderating Effect of Daylight Exposure on the Relationship Between Physical Activity and Sleep in Patients with Upper Digestive Cancer: An Exploratory Study

ObjectivesTo examine the moderating effect of daylight exposure on physical activity and objective sleep quality, using wearable actigraph devices. MethodsWe recruited 324 patients with either gastric or esophageal cancer. Actigraphs were used to measure all objective data including daylight exposure, physical activity, and sleep quality. Pearson's correlation coefficients were used to examine the relationships among demographic data, disease attributes, physical activity, daylight exposure, and sleep. The Hayes PROCESS macro with the regression bootstrapping method was employed to analyze the moderating effect of daylight exposure on the relationship between physical activity and sleep. ResultsSleep efficiency correlated positively with physical activity, while “wake after sleep onset” correlated negatively with physical activity and mean lux. Mean lux and light >500 lux significantly moderated the association between physical activity and sleep efficiency (P = .002 in both cases). Similarly, mean lux and light >500 lux significantly moderated the association between physical activity and “wake after sleep onset” (P = .002 and .001, respectively). ConclusionBoth average daylight exposure and time of exposure to >500 lux act as moderators of physical activity and objective sleep quality in patients with gastric or esophageal cancer. Healthcare practitioners should encourage patients with cancer to engage in daily outdoor physical activity. Further intervention studies are needed to verify the combined effect of daytime light exposure and physical activity on improving sleep quality. Implications for Nursing PracticeHealthcare practitioners should encourage patients with cancer to engage in daily outdoor physical activity. Further intervention studies are needed to verify the combined effect of daytime light exposure and physical activity on improving sleep quality.

Does overreaching from endurance-based training impair sleep: A systematic review and meta-analysis.

Overreaching is often linked to a deterioration in sleep quality, yet a comprehensive review is lacking. The aim of this systemic review and meta-analysis was to synthesise the literature and quantify the effect of overreaching from endurance-based training on sleep quality. The review was conducted following the PRISMA guidelines. The final search was conducted in May 2023 using four electronic databases (Web of Science Core Collection, MEDLINE, Cochrane Central Database, SPORTDiscus). Studies were included for a qualitative review, while random-effects meta-analyses were conducted for objective and subjective sleep. The search returned 805 articles. Fourteen studies were included in the systematic review; Three and eight articles were eligible for the meta-analyses (objective and subjective, respectively). On average, the overreaching protocols were sixteen days in length (6 to 28 days) and included exercise modalities such as cycling (number of studies [k] = 5), rowing (k = 4), triathlon (k = 3), running (k = 2), and swimming (k = 1). Actigraphy was the only form of objective sleep measurement used across all studies (k = 3), while various instruments were used to capture subjective sleep quality (k = 13). When comparing objective sleep quality following the overreaching intervention to baseline (or a control), there was a significant reduction in sleep efficiency (mean difference = -2.0%; 95% CI -3.2, -0.8%; Glass' Δ = -0.83; p < 0.01). In contrast, when comparing subjective sleep quality following the overreaching intervention to baseline (or a control), there was no effect on subjective sleep quality (Glass' Δ = -0.27; 95% CI -0.79, 0.25; p = 0.08). Importantly, none of the included studies were judged to have a low risk of bias. While acknowledging the need for more high-quality studies, it appears that overreaching from endurance-based training can deteriorate objective sleep without influencing the perception of sleep quality. This protocol was registered in The International Prospective Register of Systematic Reviews (PROSPERO) on 21st November 2022, with the registration number CRD42022373204.

Serum levels of neurotensin, pannexin-1, and sestrin-2 and the correlations with sleep quality or/and cognitive function in the patients with chronic insomnia disorder.

To examine serum concentrations of neurotensin, pannexin-1 and sestrin-2, and their correlations with subjective and objective sleep quality and cognitive function in the patients with chronic insomnia disorder (CID). Sixty-five CID patients were enrolled continuously and fifty-six good sleepers in the same period were served as healthy controls (HCs). Serum levels of neurotensin, pannexin-1 and sestrin-2 were measured by enzyme-linked immunosorbent assays. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) and polysomnography, and mood was evaluated by 17-item Hamilton Depression Rating Scale. General cognitive function was assessed with the Chinese-Beijing Version of Montreal Cognitive Assessment and spatial memory was evaluated by Blue Velvet Arena Test (BVAT). Relative to the HCs, the CID sufferers had higher levels of neurotensin (t=5.210, p<0.001) and pannexin-1 (Z=-4.169, p<0.001), and lower level of sestrin-2 (Z=-2.438, p=0.015). In terms of objective sleep measures, pannexin-1 was positively associated with total sleep time (r=0.562, p=0.002) and sleep efficiency (r=0.588, p=0.001), and negatively with wake time after sleep onset (r=-0.590, p=0.001) and wake time (r=-0.590, p=0.001); sestrin-2 was positively associated with percentage of rapid eye movement sleep (r=0.442, p=0.016) and negatively with non-rapid eye movement sleep stage 2 in the percentage (r=-0.394, p=0.034). Adjusted for sex, age and HAMD, pannexin-1 was still associated with the above objective sleep measures, but sestrin-2 was only negatively with wake time (r=-0.446, p=0.022). However, these biomarkers showed no significant correlations with subjective sleep quality (PSQI score). Serum concentrations of neurotensin and pannexin-1 were positively associated with the mean erroneous distance in the BVAT. Adjusted for sex, age and depression, neurotensin was negatively associated with MoCA score (r=-0.257, p=0.044), pannexin-1 was positively associated with the mean erroneous distance in the BVAT (r=0.270, p=0.033). The CID patients had increased neurotensin and pannexin-1 and decreased sestrin-2 in the serum levels, indicating neuron dysfunction, which could be related to poor sleep quality and cognitive dysfunction measured objectively.

Associations of dietary patterns with objective and subjective sleep duration and sleep quality in a population-based cohort study

ObjectiveTo examine cross-sectional and longitudinal associations of various types of dietary patterns with self-reported sleep quality and with actigraphy-estimated sleep parameters in the prospective, population-based Rotterdam Study. MethodsFor each participant, scores for five different dietary patterns were derived based on food frequency questionnaires; two pre-defined scores developed to estimate adherence to the Dutch dietary guidelines and to the Mediterranean diet; and three data-driven scores indicating a prudent, unhealthy and typical Dutch diet. In 2589 participants (median age 56.9 years; 58 % female), self-rated sleep quality was assessed with the Pittsburgh Sleep Quality Index. In 533 participants, actigraphs were worn for an average of 6.8 days (SD: 0.7) to estimate total sleep time, sleep onset latency, wake after sleep onset, and sleep efficiency. Sleep parameters were measured at baseline and 3–6 years later. Multiple linear regression was used to assess cross-sectional and longitudinal associations. ResultsNo statistically significant associations between dietary patterns and total sleep time, sleep onset latency, wake after sleep onset, sleep efficiency and subjective sleep quality were observed in cross-sectional or longitudinal analyses. To illustrate, the effect estimate for sleep duration was 2.7 min per night (95 % CI -2.1, 7.5) per 5 point increase in Mediterranean diet score in the cross-sectional analyses. Furthermore, in longitudinal analyses, the effect estimate for sleep duration was −1.0 min per night (95 % CI -5.2, 3.1) per SD increase in the prudent diet. ConclusionsOur results suggest that dietary patterns are not associated with sleep in this population-based cohort study. Trial registrationNetherlands National Trial Register and WHO International Clinical Trials Registry Platform (ICTRP; https://apps.who.int/trialsearch/) shared catalogue number NL6645/NTR6831. Registered November 13th, 2017.

1125 Use of a Pillow Designed to Help Users Feel Cool Improves Objective Sleep Quality and Perceived Sleep

1125 Use of a Pillow Designed to Help Users Feel Cool Improves Objective Sleep Quality and Perceived Sleep

Electroencephalography-based investigation of the effects of oral desmopressin on improving slow-wave sleep time in nocturnal polyuria patients (the DISTINCT study): A single-arm, open-label, single-assignment trial.

To investigate changes in subjective and objective sleep quality after desmopressin administration in patients with nocturia due to nocturnal polyuria (NP) using electroencephalography (EEG) and the Pittsburgh sleep quality index (PSQI). Twenty male patients (≥65 years old) with NP participated in this study. The inclusion criteria were nocturnal frequency ≥ 2, NP index (NPi) ≥ 0.33, first uninterrupted sleep period (FUSP) ≤ 2.5 h, serum sodium concentration ≥ 135 mEq/L, and estimated glomerular filtration rate ≥ 50 mL/min/1.73 m2. Participants were given 50 μg of desmopressin to be taken orally once daily before bed. The primary endpoint was the change in the duration of slow-wave sleep (nonrapid eye movement sleep stages 3 and 4), as evaluated by EEG 28 days from the baseline. The visual analog scale (VAS) was used as an additional indicator of sleep quality. Analysis of data from 15 participants (median age: 74.0 [70.5, 76.0] years) revealed that from before to after desmopressin administration, significant decreases occurred in the median nocturnal frequency (3.0 [2.0, 4.0] to 1.5 [1.0, 2.0]) and NPi (0.445 [0.380, 0.475] to 0.360 [0.250, 0.430]). Furthermore, FUSP was significantly prolonged from 120.0 (94.0, 150.0) min to 210.0 (203.8, 311.3) min. Although the VAS scores improved, slow-wave sleep duration and the PSQI global score showed no significant differences (68.50 [47.50, 75.50] and 48.00 [38.00, 66.50]; 5.0 [5.0, 10.0] and 7.0 [5.0, 9.0] min, respectively). Oral administration of 50 μg desmopressin improved nocturnal frequency and FUSP in older individuals with NP but did not significantly enhance sleep quality. In older adults, decreased nighttime urinary frequency may enhance quality of life; however, its influence on objective sleep quality may be limited.

Effect of Hemerocallis essence aroma on brain activity and sleep processes via scalp electroencephalogram

AbstractSleep disorders are widespread. Inhaled aromatherapy has shown advantages over medication in treating insomnia. Daylily (Hemerocallis fulva) has been found to positively affect sleep either by ingestion or inhalation, but there is a lack of research on the sleep aid effect of its inhalation route. At present, the floral scent characteristics of daylily are not obvious, and the extraction rate of essential oil is low. Based on the above problems, this study developed daylily essence which replicates the natural aroma of plants and investigated the effect of inhaling daylily essence aroma on sleep activity by using Pittsburgh Sleep Quality Index (PSQI) and electroencephalogram (EEG). According to PSQI results, inhaling the aroma of daylily essence improved participants' subjective sleep quality. The difference between men and women was statistically significant (p &lt; .05). The slow‐wave sleep activity of EEG in the experimental group was significantly stronger than that in the control group (p &lt; .01). In addition, the frontal and central regions were more responsive to aroma stimuli (p &lt; .05). The results of this study show that the aroma of daylily can promote the subjective and objective sleep quality of healthy college students, and the use of fragrance intervention is a potential scheme to improve sleep quality and insomnia.

Effect of a nutraceutical combination on sleep quality among people with impaired sleep: a randomised, placebo-controlled trial

In this randomised, placebo-controlled trial, adults with impaired sleep (Pittsburgh Sleep Quality Index ≥ 5) were randomly assigned using a minimization algorithm to receive a formulation containing l-theanine plus lemon balm, valerian, and saffron extracts, or placebo, during 6 weeks. Objective sleep quality parameters were measured using an actigraphy device. We enrolled and randomised 64 individuals, 31 from the active group and 27 from the placebo group completed the 6 week follow-up. Mean sleep efficiency remained unmodified in the active group, and increased by 3% in the placebo group, the between-group difference in the change was not statistically significant (p = 0.49). Total sleep time also improved more with placebo (13.0 vs. 1.33 min, p = 0.66). Time wake after sleep onset (WASO) decreased more in the active group (4.6% vs. 2.4%), but the difference was not significant (p = 0.33). Mean PSQI decreased by 3.11 points (32.3%) in the active group, and by 3.86 points (39.5%) in the placebo group (p = 0.41). SF-36 increased more with placebo (+ 18.3 in active, + 32.1 in placebo, p = 0.68). Salivary cortisol remained unchanged in both groups. No serious adverse events were reported. Among adults with impaired sleep, a nutraceutical combination did not improve objective or subjective sleep parameters more than a placebo infusion.

The Ultra-Long-Term Sleep study: Design, rationale, data stability and user perspective.

Sleep deprivation and poor sleep quality are significant societal challenges that negatively impact individuals' health. The interaction between subjective sleep quality, objective sleep measures, physical and cognitive performance, and their day-to-day variations remains poorly understood. Our year-long study of 20 healthy individuals, using subcutaneous electroencephalography, aimed to elucidate these interactions, assessing data stability and participant satisfaction, usability, well-being and adherence. In the study, 25 participants were fitted with a minimally invasive subcutaneous electroencephalography lead, with 20 completing the year of subcutaneous electroencephalography recording. Signal stability was measured using covariance of variation. Participant satisfaction, usability and well-being were measured with questionnaires: Perceived Ease of Use questionnaire, System Usability Scale, Headache questionnaire, Major Depression Inventory, World Health Organization 5-item Well-Being Index, and interviews. The subcutaneous electroencephalography signals remained stable for the entire year, with an average participant adherence rate of 91%. Participants rated their satisfaction with the subcutaneous electroencephalography device as easy to use with minimal or no discomfort. The System Usability Scale score was high at 86.3 ± 10.1, and interviews highlighted that participants understood how to use the subcutaneous electroencephalography device and described a period of acclimatization to sleeping with the device. This study provides compelling evidence for the feasibility of longitudinal sleep monitoring during everyday life utilizing subcutaneous electroencephalography in healthy subjects, showcasing excellent signal stability, adherence and user experience. The amassed subcutaneous electroencephalography data constitutes the largest dataset of its kind, and is poised to significantly advance our understanding of day-to-day variations in normal sleep and provide key insights into subjective and objective sleep quality.

Relationships between rumination and different types of rapid eye movement sleep in patients with chronic insomnia disorder

Background and objectiveRumination, a common factor of chronic insomnia disorder (CID) caused by cognitive-emotional arousal, is associated with an increased amount of rapid eye movement (REM) sleep. However, the specific subtypes, such as phasic REM and tonic REM, that contribute to the increased REM sleep have not been reported. This study aimed to determine the association between rumination and different REM sleep subtypes in patients with CID. MethodsThis study enrolled 35 patients with CID and 27 age- and sex-matched healthy controls. The Immersion-Rumination Questionnaire evaluated participants' rumination, and the Insomnia Severity Index was used to assess insomnia severity. Finally, polysomnography was used to monitor objective sleep quality and quantification of different types of REM. ResultsThe CID patients had higher rumination scores than the healthy controls. They had a shorter REM sleep duration, less phasic REM, a lower percentage of phasic REM time, and a higher percentage of tonic REM time. Spectral analysis revealed that the patients affected by insomnia had higher β power during REM sleep, higher β and σ power during phasic REM sleep, and higher β, and γ power during tonic REM sleep. Partial correlation analysis showed that rumination in the CID patients correlated negatively with the duration of phasic REM sleep. Additionally, rumination correlated negatively with δ power in REM sleep and positively with β power in REM sleep, tonic REM sleep, phasic REM sleep, N3and N2 sleep in the patients with CID. ConclusionThe CID patients had stronger rumination, reduced total and phasic REM sleep, and the stronger rumination was, the shorter phasic REM was and the higher fast (β) wave power in REM sleep.

Objective sleep quality predicts subjective sleep ratings

In both clinical and observational studies, sleep quality is usually assessed by subjective self-report. The literature is mixed about how accurately these self-reports track objectively (e.g. via polysomnography) assessed sleep quality, with frequent reports of little to no association. However, previous research on this question focused on between-subject designs, which may be confounded by trait-level variables. In the current study, we used the novel Budapest Sleep, Experiences and Traits Study (BSETS) dataset to investigate if within-subject differences in subjectively reported sleep quality are related to sleep macrostructure and quantitative EEG variables assessed using a mobile EEG headband. We found clear evidence that self-reported sleep quality in the morning is influenced by within-subject variations in sleep onset latency, wake after sleep onset, total sleep time, and sleep efficiency. These effects were replicated if detailed sleep composition metrics (percentage and latency of specific vigilance states) or two alternative measures of subjective sleep quality were used instead. We found no effect of the number of awakenings or relative EEG delta and sigma power. Between-subject effects (relationships between individual mean values of sleep metrics and subjective sleep quality) were also found, highlighting that analyses focusing only on these may be erroneous. Our findings show that while previous investigations of this issue may have been confounded by between-subject effects, objective sleep quality is indeed reflected in subjective sleep ratings.