Sleep Time Research Articles

UP165, standardized corn leaf extract and its active component 6-methoxybenzoxazolinone induce non-rapid eye movement sleep through melatonergic and GABAergic mechanisms

The aim of this study was to investigate the sleep-promoting effects of corn leaf extract (UP165) and its active component 6-methoxybenzoxazolinone (6-MBOA), along with the underlying mechanisms in rodent models. Sleep activity in UP165 was measured by measuring sleep duration in the pentobarbital induced sleep model, and sleep quality was evaluated through electroencephalogram (EEG) analysis. In addition, the sleep mechanism was analyzed through an in vivo sleep study co-administrated with receptor antagonists. The administrations of both UP165 and 6-MBOA effectively increased sleep duration, demonstrating a 3-fold increase sleep time at 100 mg/kg UP165 and a 2.3-fold increase at 280 μg/kg 6-MBOA compared to those of the control group. The sleep-promoting effect of UP165 was also observed in the caffeine-induced insomnia model, resulting in a 71.6% increase in sleep duration. The UP165-mediated increase in sleep time was attributed to enhanced non-rapid eye movement (NREM) sleep, specifically an increase in the δ-wave sleep measured by EEG. Mechanism analysis with co-administration of competitive antagonists in vivo revealed that UP165 and 6-MBOA enhanced sleep duration through binding to gamma-aminobutyric acid type A (GABAA) and melatonin receptors. Oral administration of UP165 for 4 weeks effectively increased both gene expression and protein levels of GABAA, melatonin 1A, and melatonin 1B receptors. High-dose administration of UP165 significantly decreased the blood level of corticosterone, while concurrently increased GABA, serotonin, and melatonin levels in brain. This study highlights the potential of UP165 and 6-MBOA as edible-grade natural ingredients for sleep promotion.

Influence of sleep stages on determining positional dependency in patients with obstructive sleep apnea.

Supine sleep position and rapid eye movement (REM) stage are widely known to aggravate the severity of obstructive sleep apnea (OSA). In general, position-dependent OSA is defined as an apnea-hypopnea index (AHI) at least twice as high in the supine position as in other sleep positions, but it can be misdiagnosed if a certain sleep stage, REM or NREM, is dominant in a specific sleep position. In this study, we investigated the influences of the sleep stages on positional dependency. The polysomnographic data from 111 OSA patients aged ≥ 18 years (AHI > five events/hour) who slept in both supine and non-supine positions (each ≥ 5% of the total sleep time) were retrospectively analyzed. The overall ratio of non-supine AHI/supine AHI (NS/S AHI ratio) during the entire sleep was compared between specific sleep stages, i.e., REM or NREM sleep. Additionally, the weighted NS/S AHI ratio reflecting the proportion of each sleep time was created and compared with the original NS/S AHI ratio. The mean value of the NS/S AHI ratio did not differ between the entire sleep and the specific sleep stages. However, those ratios in the individual patients showed poor agreement of the NS/S AHI ratios between the entire sleep and the specific sleep stages. The weighted NS/S AHI ratio also demonstrated poor agreement with the original NS/S AHI ratio, mainly due to the discrepancy in mild to moderate OSA patients. The weighted NS/S AHI ratio might help assess precise positional dependency.

Validation of the Korean version of the Sleep Hygiene Practice Scale in a Non-Clinical Population

ABSTRACT Objectives This study aimed to validate the Korean version of the sleep hygiene practice scale (SHPS-K) and determine its effectiveness in screening poor sleepers with insomnia. Methods Online survey was conducted using translated SHPS in Korean, the Korean versions of the Pittsburgh Sleep Quality Index (PSQI-K), Insomnia Severity Index (ISI-K), and Epworth Sleepiness Scale (KESS) in a non-clinical population. The internal consistency and test-retest reliability of the SHPS-K were assessed using Cronbach’s alpha and intraclass correlation coefficients (ICC), respectively. Construct validity was evaluated using correlation analyses with other questionnaires and confirmatory factor analysis. We determined the cutoff values that could identify poor sleepers with insomnia symptoms (PSQI-K > 5 and ISI-K ≥ 15) using receiver operating characteristic analysis. Results A total of 484 participants (242 women, mean age of 43.8 years) were enrolled. The average SHPS-K score was 71.2, with no significant sex differences. Women had poorer sleep scheduling and timing behaviors, and men had poorer eating and drinking behaviors. Good internal consistency (Cronbach’s alpha = 0.88) and test-retest reliability (ICC = 0.80) were observed. The SHPS-K was positively correlated with the PSQI-K (r = 0.55), ISI-K (r = 0.54), and KESS (r = 0.42). A cutoff value of 73 identified poor sleepers with insomnia (area under the curve = 0.828). Conclusions The SHPS-K is a reliable instrument for evaluating sleep hygiene in non-clinical Korean populations.

Flavonoids from Polygoni Multiflori Caulis alleviates p-chlorophenylalanine-induced sleep disorders in mice

Polygoni Multiflori Caulis (PMC) has been traditionally served as a functional medicine due to its various biological activities, but a lack of researches focused on the sleep-enhancing effects of flavonoids from PMC. In this study, the total flavonoids (PMCF) were isolated from PMC. In vitro antioxidant experiments suggested that PMCF exhibited remarkable antioxidant capacity, as evidenced by its scavenging activity on several radicals and reducing power. Subsequently, PMCF was given to insomnia mice via intragastric administration. In behavior test, PMCF exhibited sleep-enhancing effect through suppressing depression, shortening the sleep latency time while prolonging the duration sleep time in insomnia mice. To clarified the mechanism, the neurotransmitter receptors, cytokines and hormone in brain were investigated. PMCF exhibited significant sleep promoting effect by up-regulating the expression levels of hormone-related genes, and producing stimulation on the immune system by increasing interleukin-1β mRNA expression. In addition, PMCF-mediated sleep promotion accompanied the recovery of 5-hydroxytryptamine 1 A (5-HT1A), γ-aminobutyric acid A receptor α2 (GABAARα2) and GABAA receptor α3 (GABAARα3) mRNA expression, which was more effective in the hypothalamus. Collectively, all these data implied that PMCF might produce beneficial activities in relieving sleep disturbances via the antioxidant pathway, as well as the immune, serotonergic and GABAergic systems.

Melatonin inhibits circadian gene DEC1 and TLR2/MyD88/NF-κB signaling pathway to alleviate renal injury in type 2 diabetic mice.

Diabetic Kidney Disease (DKD) is a complex disease associated with circadian rhythm and biological clock regulation disorders. Melatonin (MT) is considered a hormone with renal protective effects, but its mechanism of action in DKD is unclear. We used the GSE151325 dataset from the GEO database for differential gene analysis and further explored related genes and pathways through GO and KEGG analysis and PPI network analysis. Additionally, this study used a type 2 diabetes db/db mouse model and investigated the role of melatonin in DKD and its relationship with clock genes through immunohistochemistry, Western blot, real-time PCR, ELISA, chromatin immunoprecipitation (ChIP), dual-luciferase reporter technology, and liposome transfection technology to study DEC1 siRNA. Bioinformatics analysis revealed the central position of clock genes such as CLOCK, DEC1, Bhlhe41, CRY1, and RORB in DKD. Their interaction with key inflammatory regulators may reveal melatonin's potential mechanism in treating diabetic kidney disease. Further experimental results showed that melatonin significantly improved the renal pathological changes in db/db mice, reduced body weight and blood sugar, regulated clock genes in renal tissue, and downregulated the TLR2/MyD88/NF-κB signaling pathway. We found that the transcription factor DEC1 can bind to the TLR2 promoter and activate its transcription, while CLOCK's effect is unclear. Liposome transfection experiments further confirmed the effect of DEC1 on the TLR2/MyD88/NF-κB signaling pathway. Melatonin shows significant renal protective effects by regulating clock genes and downregulating the TLR2/MyD88/NF-κB signaling pathway. The transcription factor DEC1 may become a key regulatory factor for renal inflammation and fibrosis by activating TLR2 promoter transcription. These findings provide new perspectives and directions for the potential application of melatonin in DKD treatment.

The influence of monosodium glutamate on the development of oxidative-nitrosative stress in the large cerebral hemispheres of rats under the combination of a change in the “light-dark” cycle and a systemic inflammatory response

Today, the issue of the consequences of disrupting the normal “light-dark” cycle is becoming increasingly important, and the link between the development of a systemic inflammatory response (SIR) and circadian rhythm disorders has been confirmed. The effect of monosodium glutamate on the human body is being actively studied. The aim of the work was to find out the influence of monosodium glutamate on the development of oxidative-nitrosative stress in the homogenate of the large cerebral hemispheres of rats with a combination of acute desynchronosis (AD), SIR and administration of monosodium glutamate. Material and methods. The research was carried out on 72 white Wistar rats weighing 150–200 of different sexes, divided into 5 groups: control (n = 15), AD (n = 13), SIR (n = 15), a combination of SIR and AD (n = 14), a combination of SIR, AD, and glutamate (n = 15). To simulate AD, a normal “light-dark” cycle (12 hours of light, 12 hours of darkness) was formed for 3 weeks, and the next 3 days the “light-dark” phases were shifted back by 6 hours. SIR was reproduced by intraperitoneal injection of Salmonella typhi lipopolysaccharide in the first week at a dose of 0.4 μg/kg 3 times per week, the following seven weeks – once a week. Sodium glutamate was administered intragastrically for 20 days at a dose 30 mg/kg, dissolved in 0.5 ml of distilled water. In a 10 % homogenate of the large cerebral hemispheres, we determined the rate of superoxide anion radical (SAR) production, the content of products that react with thiobarbituric acid (TBA-reactants), their increase, activity of catalase, superoxide dismutase (SOD), ornithine decarboxylase (ODC), concentration of nitrites, peroxynitrites, total activity of NO-synthase (NOS), its constitutive (cNOS) and inducible (iNOS) isoforms. Results. In the group of SIR, AD and glutamate combination, compared to the control, the following was noted: an increase in the rate of basic production of SAR by 175.8 %, by the microsomal pathway by 20.0 %, by the mitochondrial pathway by 51.2 %, the concentration of TBA-reactants by 83.4 %, their increase – by 61.7 %, decrease in the activity of SOD by 57.1 %, catalase – by 38.1 %; an increase in peroxynitrite content by 116.7 %, ODC activity by 161.5 %, total NOS activity by 25.6 % and iNOS by 27.4 %, a decrease in cNOS activity by 15.0 % and nitrite concentration by 35.0 % in brain tissues. Conclusions. Sodium glutamate administration in combination with AD and SIR leads to increased oxidative-nitrosative stress, inhibition of antioxidant protection; contributes to the activation of the general activity of NO-synthase and iNOS, suppresses the activity of cNOS.

Joint Association of Sleep Onset Time and Sleep Duration With Cardiometabolic Health Outcome.

The association of sleep onset time and duration with cardiometabolic health is not well characterized. This study included 6696 adults aged 20 to 80 years from the NHANES (National Health and Nutrition Examination Study) 2015 to 2018. Participants were categorized into 9 groups according to the cross-tabulation of sleep onset time (<22:00 [early], 22:00-23:59 [optimal], and ≥24:00 [late]) and duration (<7 hours [insufficient], 7-8 hours [sufficient], and ≥9 hours [excessive]), with optimal sleep onset time and sufficient duration as the reference. The primary outcomes included hypertension, hypertriglyceridemia, low high-density lipoprotein cholesterol, hyperglycemia, central obesity, and metabolic syndrome. Inappropriate sleep onset time and sleep duration were associated with increased odds of hypertension, hypertriglyceridemia, and metabolic syndrome, especially among participants aged 40 to 59 years. Compared with men reporting optimal onset and sufficient duration, men reporting optimal onset with excessive duration (odds ratio [OR]: 2.01 [95% CI, 1.12-3.58]) and late onset with insufficient duration (OR, 1.74 [95% CI, 1.13-2.68]) had higher odds of metabolic syndrome. Compared with women reporting optimal onset and sufficient duration, women reporting optimal onset and insufficient duration (OR, 1.61 [95% CI, 1.11-2.32]) and early onset and excessive duration (OR, 2.16 [95% CI, 1.30-3.57]) had higher odds of hypertension, and women reporting late onset and excessive duration (OR, 5.64 [95% CI, 1.28-6.77]) were at the highest odds of hypertriglyceridemia. Late sleep onset as well as insufficient or excessive sleep duration are associated with adverse cardiometabolic outcomes, particularly in participants aged 40 to 59 years.

Analgesic Effect and Sleep Quality of Low-Dose Dexmedetomidine in Cardiac Surgical Patients After Ultrafast-Track Extubation: A Randomized Clinical Trial

To compare the analgesic and sleep quality effects of dexmedetomidine infusion versus placebo in patients undergoing cardiac surgery with ultra-fast track extubation. The randomized, double-blind clinical trial study. At a single academic center hospital. We included patients aged 25 to 65 scheduled for elective cardiac surgery under general anesthesia with cardiopulmonary bypass from October 2021 to December 2022. After immediate extubation in the operating room, the patients who were allocated at first after providing their consent to either the dexmedetomidine group (Dex) or the placebo group (Placebo) received continuous infusion of dexmedetomidine (0.2 μg/kg/h) or saline for 12 hours postoperatively. The groups' demographic and perioperative variables were not statistically significant. Total morphine consumption in milligrams at 12 and 24 hours after administered study drug, total sleep time in hours by BIS value ≤85, and sleep quality with the Richard-Campbell Sleep Questionnaire were compared. The analysis included 22 Dex and 23 Placebo patients. The consumption of morphine was not statistically different between the Dex and Placebo groups at 12 and 24 hours (p = 0.707 and p = 0.502, respectively). The Dex group had significantly longer sleep time (8.7 h [7.8, 9.5]) than the Placebo group (5.8 h [2.9, 8.5]; p = 0.007). The Dex group also exhibited better sleep quality (7.9 [6.7, 8.7] vs 6.6 [5.2, 8.0]; p = 0.038). Sedation with low-dose dexmedetomidine infusion for ultra-fast track extubation following cardiac surgery enhances sleep duration and quality.

Psychological aspects of the longest, solo, unsupported one-way polar ski expedition in Antarctica by a female adventurer

IntroductionAntarctic expeditions present exceptional physiological and mental challenges. Research data are lacking on psychological aspects of such endeavours. The aim of our study is to provide data on changes in...

Sleep Duration and Blood Pressure in Youth Referred for Elevated Blood Pressure Evaluation.

Sleep promotion is not specifically recommended as a target for hypertension management. We examined associations of sleep duration and timing with blood pressure parameters in patients referred to pediatric nephrology clinic for elevated blood pressure evaluation. This is a retrospective study of initial ambulatory blood pressure monitoring data and self-report sleep data collected from patients referred to nephrology clinic for the evaluation of elevated blood pressure. Linear and logistic regression modeling determined associations between sleep exposures (duration and timing) and continuous and dichotomous blood pressure outcomes, respectively, adjusted for age, sex, body mass index, and weekday versus weekend status. The study sample included 539 patients with mean age 14.6 years and 56% meeting hypertension criteria. Sleep duration averaged 9.1 hours per night. Average timing of sleep onset and offset were 11:06 pm and 8:18 am, respectively. Longer sleep duration was associated with better daytime blood pressure parameters (eg, every extra hour of sleep duration was associated with a reduced odds of wake hypertension [odds ratio, 0.88; 95% CI, 0.79-0.99]). Later sleep onset was associated with worse daytime blood pressure parameters (eg, each additional hour of later sleep onset was associated with higher wake systolic blood pressure index [mean wake blood pressure/95th percentile]) (β = 0.07; 95% CI, 0.02-0.13). Associations were consistent across sex, age, body mass index, and weekday status. Longer sleep duration and earlier sleep onset were associated with lower blood pressure. This suggests that sleep optimization may be an important target for intervention in hypertension management.

Commercial Chinese polyherbal preparation Zao Ren An Shen prescription for primary insomnia: a systematic review with meta-analysis and trial sequential analysis.

Background: Natural products are widely used for primary insomnia (PI). This systematic review with trial sequential analysis (TSA) aimed to summarize evidence pertaining to the effectiveness and safety of Zao Ren An Shen (ZRAS) prescription, a commercial Chinese polyherbal preparation, for treating PI. Methods: Controlled clinical trials appraising ZRAS compared to controls or as an add-on treatment were systematically searched across seven databases until January 2024. Cochrane ROB 2.0 and ROBINS-I tools were adopted to determine risk of bias. Quality of evidence was assessed using the GRADE framework. Results: We analyzed 22 studies, involving 2,142 participants. The effect of ZRAS in reducing Pittsburgh Sleep Quality Index scores was found to be comparable to benzodiazepines [MD = 0.39, 95%CI (-0.12, 0.91), p = 0.13] and superior to Z-drugs [MD = -1.31, 95%CI (-2.37, -0.24), p = 0.02]. The addition of ZRAS to hypnotics more significantly reduced polysomnographically-recorded sleep onset latency [MD = -4.44min, 95%CI (-7.98, -0.91), p = 0.01] and number of awakenings [MD = -0.89times, 95%CI (-1.67, -0.10), p = 0.03], and increased total sleep time [MD = 40.72min, 95%CI (25.14, 56.30), p < 0.01], with fewer adverse events than hypnotics alone. TSA validated the robustness of these quantitative synthesis results. However, the quality of evidence ranged from very low to low. The limited data available for follow-up did not support meta-synthesis. Conclusion: While ZRAS prescription shows promising effectiveness in treating PI, the overall quality of evidence is limited. Rigorously-designed randomized control trials are warranted to confirm the short-term efficacy of ZRAS and explore its medium-to-long-term efficacy. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=471497), identifier (CRD42023471497).

Association between sleep state misperception and bedtime behavior in patients with chronic insomnia

Previous studies on sleep state misperception have objectively evaluated sleep status in special environments using polysomnography. There is a paucity of data from studies that evaluated habitual sleep status in home environments. The present study aimed to investigate sleep state misperception in the home environment of patients with chronic insomnia using a lumbar-worn actigraphy to identify sleep habits associated with sleep state misperception severity. Thirty-one patients and 42 healthy volunteers were included in the insomnia and non-insomnia group, respectively. Participants recorded subjective assessments in sleep diaries, objective assessments with an actigraphy worn for 14 days, and self-assessments using questionnaires. Both groups had similar objective sleep ratings; however, insomnia group had significantly worse subjective ratings (total sleep time, wake after sleep onset, and sleep onset latency). A significant correlation was found between subjective and objective total sleep time scores in non-insomnia group but not in insomnia group. Insomnia group had earlier bedtimes, significantly longer bedtimes, and impaired daytime functioning (Sheehan Disability Scale score); additionally, they underestimated their total sleep time, particularly with earlier bedtimes and longer laying durations. Monitoring the sleep status and habits of individuals in home environments could be instrumental in identifying key points for targeted interventions on sleep hygiene and cognitive behavioral therapy for insomnia.

Adult Inception of Ketogenic Diet Therapy Increases Sleep during the Dark Cycle in C57BL/6J Wild Type and Fragile X Mice.

Sleep problems are a significant phenotype in children with fragile X syndrome. Our prior work assessed sleep-wake cycles in Fmr1KO male mice and wild type (WT) littermate controls in response to ketogenic diet therapy where mice were treated from weaning (postnatal day 18) through study completion (5-6 months of age). A potentially confounding issue with commencing treatment during an active period of growth is the significant reduction in weight gain in response to the ketogenic diet. The aim here was to employ sleep electroencephalography (EEG) to assess sleep-wake cycles in mice in response to the Fmr1 genotype and a ketogenic diet, with treatment starting at postnatal day 95. EEG results were compared with prior sleep outcomes to determine if the later intervention was efficacious, as well as with published rest-activity patterns to determine if actigraphy is a viable surrogate for sleep EEG. The data replicated findings that Fmr1KO mice exhibit sleep-wake patterns similar to wild type littermates during the dark cycle when maintained on a control purified-ingredient diet but revealed a genotype-specific difference during hours 4-6 of the light cycle of the increased wake (decreased sleep and NREM) state in Fmr1KO mice. Treatment with a high-fat, low-carbohydrate ketogenic diet increased the percentage of NREM sleep in both wild type and Fmr1KO mice during the dark cycle. Differences in sleep microstructure (length of wake bouts) supported the altered sleep states in response to ketogenic diet. Commencing ketogenic diet treatment in adulthood resulted in a 15% (WT) and 8.6% (Fmr1KO) decrease in body weight after 28 days of treatment, but not the severe reduction in body weight associated with starting treatment at weaning. We conclude that the lack of evidence for improved sleep during the light cycle (mouse sleep time) in Fmr1KO mice in response to ketogenic diet therapy in two studies suggests that ketogenic diet may not be beneficial in treating sleep problems associated with fragile X and that actigraphy is not a reliable surrogate for sleep EEG in mice.

Exploring the causal effects of sleep characteristics on TMD-related pain: a two-sample Mendelian randomization study.

The study was to explore the causal effects of sleep characteristics on temporomandibular disorder (TMD)-related pain using Mendelian randomization (MR) analysis. Five sleep characteristics (short sleep, insomnia, chronotype, snoring, sleep apnea) were designated as exposure factors. Data were obtained from previous publicized genome-wide association studies and single nucleotide polymorphisms (SNPs) strongly associated with them were utilized as instrumental variables (IVs). TMD-related pain was designed as outcome variable and sourced from the FinnGens database. MR analysis was employed to explore the causal effects of the five sleep characteristics on TMD-related pain. The causal effect was analyzed using the inverse variance-weighted (IVW), weighted median, and MR-Egger methods. Subsequently, sensitivity analyses were conducted using Cochran's Q tests, funnel plots, leave-one-out analyses, and MR-Egger intercept tests. A causal effect of short sleep on TMD-related pain was revealed by IVW (OR: 1.60, 95% CI: 1.06-2.41, P = 0.026). No causal relationship was identified between other sleep characteristics (insomnia, chronotype, snoring, sleep apnea) and TMD-related pain. Our study suggests that short sleep may increase the risk of TMD-related pain, while there was no causal relationship between other sleep characteristics and TMD-related pain. Further studies are warranted to deepen and definitively clarify their relationship. These findings reveal that the short sleep may be a risk factor of TMD-related pain and highlight the potential therapeutical effect of extending sleep time on alleviating TMD-related pain.

Mediation effect of sleep time on the association between outdoor activity and myopia in Chinese children and adolescents: a cross-sectional study.

This study aimed to assess the association between outdoor activity and myopia among children and adolescents and investigate whether sleep time could mediate this relationship. This cross-sectional study was performed on students aged 4-16years in China, from August 2021 to January 2022. Outdoor activity was assessed by the Assessment Questionnaire of Exposure to Sunlight Activities for Students (AQESAS). Binary logistic regression combined with the mediation analysis was used to analyze the association of AQESAS with myopia and the mediating effect of sleep time on this relationship. The prevalence of myopia was 53.51% (N=1609). Multivariate logistic regression analysis showed that more sleep time (OR=0.794, 95%CI: 0.707-0.893) and a higher score of AQESAS (OR=0.989, 95%CI: 0.981-0.996) were significantly associated with a decreased risk of myopia. Mediation analysis revealed that sleep time plays a mediating role in the association between outdoor activity and myopia (ACME=-0.0006, P<0.001), and the mediation proportion was 19.7%. Outdoor activity affects myopia directly and indirectly through sleep time. The result suggested that children may be able to reduce the risk of myopia by promoting sleep through increased awareness of outdoor activity and exposure to sunlight.

Recognition of apnea and hypopnea by non-contact optical fiber mattress and its application in the diagnosis of obstructive sleep apnea hypopnea syndrome: a retrospective study.

This study sought to evaluate the diagnostic value of a non-contact optical fiber mattress for apnea and hypopnea and compare it with traditional polysomnography (PSG) in adult obstructive sleep apnea hypopnea syndrome (OSAHS). To determine the value of a non-contact optical fiber mattress for apnea and hypopnea, six healthy people and six OSAHS patients were selected from Tongji Hospital to design a program to identify apnea or hypopnea. A total of 108 patients who received polysomnography for drowsiness, snoring or other suspected OSAHS symptoms. All 108 patients were monitored with both the non-contact optical fiber mattress and PSG were collected. Six healthy controls and six patients with OSAHS were included. The mean apnea of the six healthy controls was 1.22 times/h, and the mean hypopnea of the six healthy controls was 2 times/h. Of the six patients with OSAHS, the mean apnea was 12.63 times/h, and the mean hypopnea was 19.25 times/h. The non-contact optical fiber mattress results showed that the mean apnea of the control group was 3.17 times/h and the mean hypopnea of the control group was 3.83 times/h, while the mean apnea of the OSAHS group was 11.95 times/h and the mean hypopnea of the OSAHS group was 17.77 times/h. The apnea index of the non-contact optical fiber mattress was positively correlated with the apnea index of the PSG (P < 0.05, r = 0.835), and the hypopnea index of the non-contact optical fiber mattress was also positively correlated with the hypopnea index of the PSG (P < 0.05, r = 0.959). The non-contact optical fiber mattress had high accuracy (area under curve, AUC = 0.889), specificity (83.4%) and sensitivity (83.3%) for the diagnosis of apnea. The non-contact fiber-optic mattress also had high accuracy (AUC = 0.944), specificity (83.4%) and sensitivity (100%) for the diagnosis of hypopnea. Among the 108 patients enrolled, there was no significant difference between the non-contact optical fiber mattress and the polysomnography monitor in total recording time, apnea hypopnea index (AHI), average heart rate, tachycardia index, bradycardia index, longest time of apnea, average time of apnea, longest time of hypopnea, average time of hypopnea, percentage of total apnea time in total sleep time and percentage of total hypopnea time in total sleep time. The AHI value of the non-contact optical fiber mattress was positively correlated with the AHI value of the PSG (P < 0.05, r = 0.713). The specificity and sensitivity of the non-contact optical fiber mattress AHI in the diagnosis of OSAHS were 95% and 93%, with a high OSAHS diagnostic accuracy (AUC = 0.984). The efficacy of the non-contact optical fiber mattress for OSAHS monitoring was not significantly different than PSG monitoring. The specificity of the non-contact optical mattress for diagnosing OSAHS was 95% and its sensitivity was 93%, with a high OSAHS diagnostic accuracy.

Developing Methods for Assessing Mental Activity Using Human-Smartphone Interactions: Comparative Analysis of Activity Levels and Phase Patterns in General Mental Activities, Working Mental Activities, and Physical Activities.

Human biological rhythms are commonly assessed through physical activity (PA) measurement, but mental activity may offer a more substantial reflection of human biological rhythms. This study proposes a novel approach based on human-smartphone interaction to compute mental activity, encompassing general mental activity (GMA) and working mental activity (WMA). A total of 24 health care professionals participated, wearing wrist actigraphy devices and using the "Staff Hours" app for more than 457 person-days, including 332 workdays and 125 nonworkdays. PA was measured using actigraphy, while GMA and WMA were assessed based on patterns of smartphone interactions. To model WMA, machine learning techniques such as extreme gradient boosting and convolutional neural networks were applied, using human-smartphone interaction patterns and GPS-defined work hours. The data were organized by date and divided into person-days, with an 80:20 split for training and testing data sets to minimize overfitting and maximize model robustness. The study also adopted the M10 metric to quantify daily activity levels by calculating the average acceleration during the 10-hour period of highest activity each day, which facilitated the assessment of the interrelations between PA, GMA, and WMA and sleep indicators. Phase differences, such as those between PA and GMA, were defined using a second-order Butterworth filter and Hilbert transform to extract and calculate circadian rhythms and instantaneous phases. This calculation involved subtracting the phase of the reference signal from that of the target signal and averaging these differences to provide a stable and clear measure of the phase relationship between the signals. Additionally, multilevel modeling explored associations between sleep indicators (total sleep time, midpoint of sleep) and next-day activity levels, accounting for the data's nested structure. Significant differences in activity levels were noted between workdays and nonworkdays, with WMA occurring approximately 1.08 hours earlier than PA during workdays (P<.001). Conversely, GMA was observed to commence about 1.22 hours later than PA (P<.001). Furthermore, a significant negative correlation was identified between the activity level of WMA and the previous night's midpoint of sleep (β=-0.263, P<.001), indicating that later bedtimes and wake times were linked to reduced activity levels in WMA the following day. However, there was no significant correlation between WMA's activity levels and total sleep time. Similarly, no significant correlations were found between the activity levels of PA and GMA and sleep indicators from the previous night. This study significantly advances the understanding of human biological rhythms by developing and highlighting GMA and WMA as key indicators, derived from human-smartphone interactions. These findings offer novel insights into how mental activities, alongside PA, are intricately linked to sleep patterns, emphasizing the potential of GMA and WMA in behavioral and health studies.

Dietary supplementation with Lactium and L-theanine alleviates sleep disturbance in adults: a double-blind, randomized, placebo-controlled clinical study.

The use of natural products for the treatment of sleep disturbances is increasing owing to the side effects and limitations of traditional sleep therapy. Moreover, recent studies have shown a significant correlation between sleep quality and gut microbiota composition. This study aimed to assess the impact of LTC-022, a commercially available dietary supplement containing Lactium and L-theanine, on enhancing sleep quality. Forty participants experiencing sleep discomfort were enrolled in a double-blind randomized controlled trial, wherein they received LTC-022 or a placebo orally for 8 weeks. The effects of treatment on sleep quality were assessed using the Pittsburgh Sleep Quality Index and Insomnia Severity Index. To comprehensively evaluate changes in sleep patterns, various parameters were evaluated, including the time in bed (TIB), total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), wake after sleep onset (WASO) counts, and bedtime. These parameters were derived from daily sleep logs recorded over the 8-week study period, categorized into weekdays and weekends. Stool samples were analyzed for microbiome composition. The V4 region of bacterial 16S rRNA genes was amplified using specific primers (515F and 806R) and targeted for analysis. Microbial diversity, including operational taxonomic units, the Shannon and Chao indices, the Firmicutes/Bacteroidetes (F/B) ratio, and the variety of bacterial taxa, was assessed. No significant differences were observed in sleep quality and insomnia scale characteristics between the two groups. In-depth analysis using sleep diaries showed that WASO counts after 8 weeks and bedtime after 4 weeks showed significant differences between the LTC-022 and control groups. In the LTC-022 group, significant differences were observed in the increase in TST, decrease in SOL, increase in SE, decrease in WASO counts, and earlier bedtime. Microbiome analysis revealed that the abundance of the genera Blautia and Ruminococcus increased in fecal samples from the LTC-022 group. These results suggest that continuous LTC-022 intake has a beneficial effect on maintaining sleep duration and an appropriate bedtime. Additionally, changes in the gut microbiota may be linked to changes in sleep patterns resulting from the consumption of Lactium and L-theanine. https://cris.nih.go.kr/cris/search/detailSearch.do/22841, KCT0007750.

Can weekend catch-up sleep decrease the risk of cognitive dysfunction in older adults?

This study investigated whether weekend catch-up sleep was related to a decreased risk of cognitive dysfunction in older Taiwanese adults by using self-reported diaries and objective accelerometer measurements. This cross-sectional study enrolled participants who were aged ≥ 65 years and had the capability to walk independently from a medical center in Taipei City, Taiwan, between September 2020 and December 2022. Self-reported sleep diaries and tri-axial accelerometers were used to record and measure sleep-related data for 7 consecutive nights. Weekend catch-up sleep was defined as the mean of weekend sleep time minus the mean of weekdays sleep time. Mini-Mental State Examination (MMSE) was evaluated the risk of cognitive dysfunction. The association between weekend catch-up sleep and the MMSE score was examined using a binary logistic regression model. A total of 215 older adults (53.0% female; 80.5 ± 7.1 years old; 11.6% at risk of cognitive dysfunction) were included. In the adjusted model (adjusted for sex, education level, moderate-to-vigorous physical activity and total accelerometer wear time), both the self-reported sleep diaries (odds ratio [OR] = 0.26, 95% confidence interval [CI] = 0.09-0.69, P = 0.007) and the accelerometer data (OR = 0.27, 95% CI = 0.10-0.70, P = 0.007) indicated that weekend catch-up sleep could decrease the risk of cognitive dysfunction by 73-74%. The study findings suggest that there is an association between weekend catch-up sleep and lower risk for cognitive decline. The causal relationship between weekend catch-up sleep and cognitive function in older adults should be further investigated in a study with longitudinal design.

An Evaluation of DNA Methylation Levels and Sleep in Relation to Hot Flashes: A Cross-Sectional Study.

Objectives: We aimed to evaluate the DNA methylation levels in perimenopausal and postmenopausal women, measured through Long Interspersed Element-1 (LINE-1) and Alu, and the sleep parameters in relation to the presence of hot flashes (HFs). Methods: This cross-sectional study included 30 peri- or postmenopausal women aged between 45 and 55. The menopausal status was determined according to STRAW + 10 criteria and all participants had a low cardiovascular disease (CVD) risk profile determined by Framingham risk score. The sample was divided into two groups based on the presence or absence of HFs documented in their medical history during their initial visit: Group 1 (n = 15) with HFs present and Group 2 (n = 15) with HFs absent. The patients had polysomnography test and HFs were recorded both by sternal skin conductance and self-report overnight. Genomic DNA was extracted from the women's blood and methylation status was analyzed by fluorescence-based real-time quantitative PCR. The quantified value of DNA methylation of a target gene was normalized by β-actin. The primary outcome was the variation in methylation levels of LINE-1 and Alu and sleep parameters according to the presence of HFs. Results: LINE-1 and Alu methylation levels were higher in Group 1 (HFs present), although statistically non-significant. LINE-1 methylation levels were negatively correlated with age. Sleep efficiency was statistically significantly lower for women in Group 1 (HFs present) (74.66% ± 11.16% vs. 82.63% ± 7.31%; p = 0.03). The ratio of duration of awakening to total sleep time was statistically significantly higher in Group 1 (HFs present) (22.38% ± 9.99% vs. 15.07% ± 6.93, p = 0.03). Objectively recorded hot flashes were significantly higher in Group 1 (4.00 ± 3.21 vs. 1.47 ± 1.46, p = 0.03). None of the cases in Group 2 self-reported HF despite objectively recorded HFs during the polysomnography. The rate of hot flash associated with awakening was 41.4% in the whole sample. Conclusions: Women with a history of hot flashes exhibited lower sleep efficiency and higher awakening rates. Although a history of experiencing hot flashes was associated with higher LINE-1 and Alu methylation levels, no statistical significance was found. Further studies are needed to clarify this association. This study was funded by the Scientific Research Projects Coordination Unit of Istanbul University-Cerrahpasa. Project number: TTU-2021-35629.