Sleep-related Variables Research Articles

Relationship between actigraphy-derived physical activity, sedentary behaviours and sleep parameters in preschool girls and boys: A cross-sectional study.

The aim of the study was to examine associations between moderate-to-vigorous physical activity and sedentary time with sleep quality and quantity among preschool girls and boys using objective methods. Children (5-6 years old) attending kindergarten were recruited (n = 676). Measures included accelerometer-derived 24-hr activity and sleep for seven consecutive days. Longer time spent in moderate-to-vigorous physical activity was associated with higher sleep efficiency both in boys (p < 0.0001) and girls (p = 0447), and with lower Sleep Fragmentation Index in boys (p = 0.0042) and girls (p = 0.0494). Moreover, among boys, moderate-to-vigorous physical activity was inversely associated with wakefulness after sleep onset (p = 0.0006), number of awakenings (p = 0.0081) and Fragmentation Index (p = 0.0041), while in girls with sleep duration (p = 0.0405), Movement Index (p = 0.0128) and Sleep Fragmentation Index (p = 0.0494). Longer time spent sedentary was associated with lower sleep efficiency, and higher wakefulness after sleep onset, number of awakenings, Movement Index and Sleep Fragmentation Index-all with p < 0.0001. Furthermore, sedentary time was inversely associated with sleep duration both in boys (p < 0.0001) and girls (p = 0.0006), and directly associated with Fragmentation Index but only in boys (p = 0.0069). Meeting the recommended level of moderate-to-vigorous physical activity was associated with better sleep efficiency, lower wakefulness after sleep onset and number of awakenings among boys. All sleep-related variables showed significant differences between quartile groups according to sedentary time (p < 0.05) in both the total group and the boys. The sedentary time had the strongest, negative effect on sleep-related parameters in preschool children, therefore sedentary time reduction may contribute more to improving sleep quality than increasing moderate-to-vigorous physical activity.

Development and Validation of Machine Learning Models to Predict Postoperative Delirium Using Clinical Features and Polysomnography Variables.

Background: Delirium affects up to 50% of patients following high-risk surgeries and is associated with poor long-term prognosis. This study employed machine learning to predict delirium using polysomnography (PSG) and sleep-disorder questionnaire data, and aimed to identify key sleep-related factors for improved interventions and patient outcomes. Methods: We studied 912 adults who underwent surgery under general anesthesia at a tertiary hospital (2013-2024) and had PSG within 5 years of surgery. Delirium was assessed via clinical diagnoses, antipsychotic prescriptions, and psychiatric consultations within 14 days postoperatively. Sleep-related data were collected using PSG and questionnaires. Machine learning predictions were performed to identify postoperative delirium, focusing on model accuracy and feature importance. Results: This study divided the 912 patients into an internal training set (700) and an external test set (212). Univariate analysis identified significant delirium risk factors: midazolam use, prolonged surgery duration, and hypoalbuminemia. Sleep-related variables such as fewer rapid eye movement (REM) episodes and higher daytime sleepiness were also linked to delirium. An extreme gradient-boosting-based classification task achieved an AUC of 0.81 with clinical variables, 0.60 with PSG data alone, and 0.84 with both, demonstrating the added value of PSG data. Analysis of Shapley additive explanations values highlighted important predictors: surgery duration, age, midazolam use, PSG-derived oxygen saturation nadir, periodic limb movement index, and REM episodes, demonstrating the relationship between sleep patterns and the risk of delirium. Conclusions: The artificial intelligence model integrates clinical and sleep variables and reliably identifies postoperative delirium, demonstrating that sleep-related factors contribute to its identification. Predicting patients at high risk of developing postoperative delirium and closely monitoring them could reduce the costs and complications associated with delirium.

Investigating the Link between Circadian Clock Gene Expressions, Chronotype, Insomnia, and Daytime Sleepiness in Patients with Obstructive Sleep Apnea.

This study aimed to investigate the relationship between obstructive sleep apnea (OSA), circadian rhythms, and individual sleep-wake preferences, as measured by chronotype, and to assess the association between circadian clock gene expression and subjective sleep-related variables. A total of 184 individuals were recruited, underwent polysomnography (PSG), and completed questionnaires including a chronotype questionnaire (CQ), insomnia severity index (ISI), and Epworth sleepiness scale (ESS). Blood samples were collected in the evening before and morning after PSG. Gene expression analysis included BMAL1, CLOCK, PER1, CRY1, NPAS2, and NR1D1. In the OSA group, the subjective amplitude (AM score of CQ) positively correlated with all circadian clock genes in the morning (R ≥ 0.230 and p < 0.05 for each one), while the morningness-eveningness (ME score of CQ) was only associated with the evening BMAL1 level (R = 0.192; p = 0.044). In healthy controls, insomnia severity correlated with evening expression of BMAL1, PER1, and CRY1. The findings highlight the complex interplay between OSA, circadian rhythms, and sleep-related variables, suggesting potential determinants of morning chronotype in OSA and implicating disrupted circadian clock function in subjective feelings of energy throughout the day. Further research is warranted to elucidate underlying mechanisms and guide personalized management strategies.

Effectiveness of Enriched Milk with Ashwagandha Extract and Tryptophan for Improving Subjective Sleep Quality in Adults with Sleep Problems: A Randomized Double-Blind Controlled Trial.

A randomized, double-blind and controlled study was conducted to assess the effectiveness of the intake of 250 mL of lactose-free skimmed milk enriched with ashwagandha (Withania somnifera) alone or combined with tryptophan vs. non-enriched milk (control) on the subjective quality of sleep in healthy adults with sleep problems. The duration of supplementation was 90 days. Fifty-two eligible subjects were assigned to the study arms of ashwagandha 250 mg, ashwagandha 250 mg plus tryptophan 175 mg, ashwagandha 600 mg, and control with 13 subjects in each group. It was hypothesized that ashwagandha plus tryptophan could be superior to ashwagandha alone for improving sleep-related variables. Changes in the visual analogue scale (VAS) for sleep quality were significantly higher in the three experimental groups as compared with controls (p = 0.014). Improvements in the subscales of the Pittsburg Sleep Quality Index (PSQI) were found in all groups, but between-group differences were not significant. In the index of insomnia severity, decreases were higher in the three experimental groups as compared with controls especially in the group of ashwagandha 600 mg. Daytime somnolence was also reduced in the three experimental groups. Changes in anxiety levels and Morningness-Eveningness Questionnaire were not observed. The study products did not elicit changes in body composition and were well tolerated and safe. The data did not support the hypothesis, as the combination of ashwagandha and tryptophan did not show greater benefits in improving sleep quality than ashwagandha alone. However, the results from the three experimental groups containing ashwagandha were more favorable compared to the placebo group.

Exploring the nexus between sleep, chronotype, and non-cognitive predictors in university students: Implications for academic success

ABSTRACT While the association between sleep-related variables and academic achievement is widely acknowledged, limited attention has been directed towards exploring non-cognitive predictors of academic achievement such as conscientiousness and self-regulation. In this study, we investigated the relationships between various sleep-related factors (circadian preference, chronotype, sleep duration, quality, and irregularity) and non-cognitive predictors (conscientiousness, self-regulation, self-efficacy, and achievement motivation) in 637 university students. Bivariate analyses revealed moderate to strong correlations among several sleep-related measures. Notably, distinctness, representing the subjective perception of daily changes, and daytime sleepiness exhibited negative associations with self-regulation, while high sleep quality was positively linked to robust self-regulation. These findings emphasize the importance of exploring various measures, particularly distinctness within circadian typology. Furthermore, we discuss the potential integration of sleep intervention programs with strategies aimed at enhancing self-regulation.

Effects of probiotics on sleep parameters: A systematic review and meta-analysis

AimAlthough sleep is essential for maintaining good health and well-being, sleep disorders are becoming increasingly prevalent. Probiotics may play a role in sleep regulation; therefore, this study aimed to provide a comprehensive overview of the effects of probiotics on sleep parameters. MethodsWe conducted a systematic literature review and meta-analysis, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. Relevant placebo-controlled randomized controlled trials examining the effects of probiotics on sleep outcomes were identified through systematic searches in the PubMed, Cochrane Library, and Ichushi databases. Data were extracted from eligible studies and the risk of bias was assessed. Statistical analyses were performed to assess the effects of probiotics on various sleep-related variables. ResultsFifteen randomized controlled trials were included in this review. The decrease in Pittsburgh Sleep Quality Index (PSQI) scores in the probiotics group was significantly lower than that in the placebo group after 4–6 weeks and 8–16 weeks, indicating improved sleep quality. The Oguri-Shirakawa-Azumi (OSA) sleep inventory score was also decreased in the probiotics group for Factor 1 “sleepiness on rising” and Factor 4 “refreshing,” indicating improved sleep quality. Some studies however, showed a risk of bias. ConclusionThis systematic review and meta-analysis indicated that probiotics may improve sleep quality, as measured by the PSQI and OSA sleep inventory. However, further research is needed to better understand the effects of probiotics on specific sleep parameters and address the limitations of existing studies.

Psychosocial Factors, Sleep, and Central Pain Processing for Making a Prognosis About Recovery of Pain, Function, and Quality of Life After Rotator Cuff Repair: An Exploratory Longitudinal Study.

OBJECTIVE: To explore modifiable psychosocial factors, sleep-related variables, indices of central pain processing and patients' characteristics as potential prognostic factors for pain, shoulder function, and quality of life (QoL) 1 year after rotator cuff repair. DESIGN: This observational longitudinal study included 142 patients who were undergoing rotator cuff repair. All measures took place pre-rotator cuff repair (T0), and 12 weeks (T1) and 12 months (T2) after rotator cuff repair. METHODS: Mixed-effects linear regression modeled relationships between the Western Ontario Rotator Cuff Index (WORC, model A), the Subjective Shoulder Value (SSV, model B), and EuroQol's EQ-5D-5L for QoL (model C), and potential prognostic factors over time. Factors included psychosocial variables, sleep-related indices, and proxies of central pain processing. Patients' age, sex, and body mass index complemented the analyses. RESULTS: At follow-up (T2), data from 124 participants were available for analysis. Five prognostic factors were identified for the 1-year outcome. Better expectations for symptom reduction (P<.0001, -1.4 mm) and an increase in Douleur Neuropathique 4 score (P = .0481, -0.9 mm) affected the evolution of WORC over time (model A). An increase in injury perception subscale consequence (P = .0035, 0.04%) influenced the SSV trajectory (model B). In addition, when sleep quality (P = .0011, -0.13%) and sleep efficiency (P = .0002, 0.005%) improved, the EQ-5D-5L slope was affected (model C). CONCLUSION: Addressing cognitions, pain mechanisms and sleep behavior prior to rotator cuff repair can identify people who are at risk of a poor outcome after surgery. J Orthop Sports Phys Ther 2024;54(8):530-540. Epub 4 July 2024. doi:10.2519/jospt.2024.12398.

Sleep is associated with telomere shortening: A population-based longitudinal study.

As the chronological age increases, there is a decrease in the telomere length (TL). Associations between TL and age-related diseases have been described. Since the major pathophysiological factors related to inadequate sleep (including sleep complaints and sleep disorders) contribute to the exacerbation of inflammation and oxidative stress, an association of sleep and TL has been proposed. The aim of this study was to evaluate the association between sleep-related variables with TL in a longitudinal framework. We used data derived from the EPISONO cohort, which was followed over 8 years. All individuals answered sleep-related questionnaires, underwent a full-night polysomnography (PSG), and had their blood collected for DNA extraction. The TL was measured through a quantitative real time polymerase chain reaction. Age, sex, body mass index (BMI), smoking, physical activity status, and the 10 principal components (ancestry estimate) were considered covariables. Of the 1042 individuals in the EPISONO cohort, 68.3% agreed to participate in the follow-up study (n = 712). Baseline SpO2 (ß = 0.008, p = 0.007), medium SpO2 (ß = 0.013, p = 0.013), and total sleep time <90% (ß = -0.122, p = 0.012) had an effect on TL from the follow-up. The 8 year TL attrition was inversely associated with total sleep time, sleep efficiency, sleep architecture variables, wake after sleep onset, arousal index, oxygen-related variables baseline, and the presence of obstructive sleep apnea (OSA). We conclude that individuals with worse sleep quality, alterations in sleep architecture, and OSA had greater TL attrition over the 8 years. Using a longitudinal approach, these findings confirm previous cross-sectional evidence linking sleep with accelerated biological ageing.

Functional changes in sleep-related arousal after ketamine administration in individuals with treatment-resistant depression

The glutamatergic modulator ketamine is associated with changes in sleep, depression, and suicidal ideation (SI). This study sought to evaluate differences in arousal-related sleep metrics between 36 individuals with treatment-resistant major depression (TRD) and 25 healthy volunteers (HVs). It also sought to determine whether ketamine normalizes arousal in individuals with TRD and whether ketamine’s effects on arousal mediate its antidepressant and anti-SI effects. This was a secondary analysis of a biomarker-focused, randomized, double-blind, crossover trial of ketamine (0.5 mg/kg) compared to saline placebo. Polysomnography (PSG) studies were conducted one day before and one day after ketamine/placebo infusions. Sleep arousal was measured using spectral power functions over time including alpha (quiet wakefulness), beta (alert wakefulness), and delta (deep sleep) power, as well as macroarchitecture variables, including wakefulness after sleep onset (WASO), total sleep time (TST), rapid eye movement (REM) latency, and Post-Sleep Onset Sleep Efficiency (PSOSE). At baseline, diagnostic differences in sleep macroarchitecture included lower TST (p = 0.006) and shorter REM latency (p = 0.04) in the TRD versus HV group. Ketamine’s temporal dynamic effects (relative to placebo) in TRD included increased delta power earlier in the night and increased alpha and delta power later in the night. However, there were no significant diagnostic differences in temporal patterns of alpha, beta, or delta power, no ketamine effects on sleep macroarchitecture arousal metrics, and no mediation effects of sleep variables on ketamine’s antidepressant or anti-SI effects. These results highlight the role of sleep-related variables as part of the systemic neurobiological changes initiated after ketamine administration. Clinical Trials Identifier: NCT00088699.

Dietary Supplementation with an Extract of Aloysia citrodora (Lemon verbena) Improves Sleep Quality in Healthy Subjects: A Randomized Double-Blind Controlled Study.

Seventy-one healthy subjects with sleep disturbances participated in a randomized, double-blind controlled trial in which dietary supplementation with an extract of Aloysia citrodora (lemon verbena) (n = 33) or placebo (n = 38) was administered for 90 days. There were between-group differences in favor of the experimental group in the visual analogue scale (VAS) for sleep quality (6.5 ± 1.6 vs. 5.5 ± 2.1, p = 0.021) as well as in the overall score (5.8 ± 2.4, p = 0.008) and scores for sleep latency (1.6 ± 1.0 vs. 1.9 ± 0.7, p = 0.027) and sleep efficiency (84.5 ± 12.8 vs. 79.8 ± 13.6, p = 0.023) in the Pittsburgh Sleep Quality Index (PSQI). Sleep-related variables (latency, efficiency, wakefulness after sleep onset, awakenings) assessed by actigraphy also showed better scores in the experimental group (p = 0.001). Plasma nocturnal melatonin levels also increased significantly in the experimental group (199.7 ± 135.3 vs. 174.7 ± 115.4 pg/mL, p = 0.048). Changes in anthropometric parameters and physical activity levels were not found. In summary, a dietary supplement of lemon verbena administered for 3 months was associated with a significant improvement in sleep quality as compared with placebo in a population of healthy subjects with sleep problems.

Development and validation of a novel sleep health score in the sleep heart health study

BackgroundThere is a lack of consensus in evaluating multidimensional sleep health, especially concerning its implication for mortality. A validated multidimensional sleep health score is the foundation of effective interventions. MethodsWe obtained data from 5706 participants in the Sleep Heart Health Study. First, random forest-recursive feature elimination algorithm was used to select potential predictive variables. Second, a sleep composite score was developed based on the regression coefficients from a Cox proportional hazards model evaluating the associations between selected sleep-related variables and mortality. Last, we validated the score by constructing Cox proportional hazards models to assess its association with mortality. ResultsThe mean age of participants was 63.2 years old, and 47.6% (2715/5706) were male. Six sleep variables, including average oxygen saturation (%), spindle density (C3), sleep efficiency (%), spindle density (C4), percentage of fast spindles (%) and percentage of rapid eye movement (%) were selected to construct this multidimensional sleep health score. The average sleep composite score in participants was 6.8 of 22 (lower is better). Participants with a one-point increase in sleep composite score had an 10% higher risk of death (hazard ratio = 1.10, 95% confidence interval: 1.08–1.12). ConclusionsThis study constructed and validated a novel multidimensional sleep health score to better predict death based on sleep, with significant associations between sleep composite score and all-cause mortality. Integrating questionnaire information and sleep microstructures, our sleep composite score is more appropriately applied for mortality risk stratification.

Sleep disturbance and internalizing symptoms in adolescents: a moderated mediation model of self-control and mindfulness

ObjectivesDespite accumulating evidence regarding the impact of sleep disturbance on internalizing symptoms among adolescents, the underlying psychological mechanisms remain inadequately explored. This study aimed to investigate a conceptual framework elucidating how sleep disturbance influences internalizing symptoms in adolescents through the mediating role of self-control, with mindfulness as a moderator.MethodsIn this cross-sectional study, 1876 Chinese adolescents (Mage = 14.88 years, SD = 1.47 years, range = 12–19 years, 44.7% boys) completed the Youth Self-Rating Insomnia Scale (YSIS), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Brief Self-control Scale (BSCS), and Mindful Attention Awareness Scale-Children (MAAS-C) to provide data on sleep-related variables, internalizing symptoms (anxiety and depression), self-control, and mindfulness, respectively. The PROCESS macro for SPSS was applied to perform moderated mediation analysis.ResultsSleep disturbance demonstrated a significant positive correlation with internalizing symptoms in adolescents, including anxiety (β = 0.481, p < 0.001) and depression (β = 0.543, p < 0.001). Self-control served as a mediator between sleep disturbance and two forms of internalizing symptoms. Moreover, mindfulness moderated the pathways from self-control to internalizing symptoms (for anxiety symptoms: β = 0.007, p < 0.001; for depression symptoms: β = 0.006, p < 0.001), and the mediating relationships were weaker for adolescents exhibiting higher levels of mindfulness.ConclusionsOur findings enhance understanding of the impact, pathways, and influencing factors of sleep disturbance on adolescent internalizing symptoms, suggesting the importance of enhancing mindfulness levels in addressing self-control deficits and subsequently reducing internalizing symptoms among adolescents.

Does Parkinson's disease affect sleep quality?

Parkinson's disease (PD) is a common neurodegenerative disease that is linked to several motor and nonmotor symptoms, including sleep disturbances. Patient quality of life has been shown to be disproportionally impacted by disease. To investigate sleep quality among individuals with PD, and to assess the severity of sleep disturbances and their impact on daytime activities. A case‒control with 44 patients with Parkinson's disease and 80 apparently healthy control participants was recruited from several hospitals and clinics. Each participant provided a thorough medical history and underwent a physical examination, and a questionnaire comprising the standard PSQI was used to assess sleep quality. Independent samples t test and Spearman's correlation analysis were used with a p value equal to or less than 0.05 which was considered significant. The mean global PSQI score was 11.55 ± 4.412 for PD patients and 5.73 ± 3.22 for the control group with significant p value, Sleep latency onset was 75.57min for PD patients and 22.81min for the control group with significant p value. There was no significant correlation between age and other sleep-related variables. A total of 86.4% of patients with Parkinson's disease suffered from varying degrees of daytime dysfunction compared to 61.25% of the controls. Parkinson's disease patients had poorer sleep quality than the controls. Age and sex were not found to be expected as a factor for sleep quality in patients with Parkinson's disease. Daytime dysfunction rates are high in patients with Parkinson's disease.

Correlates of Fundamental Motor Skills in the Early Years (0–4 Years): A Systematic Review

Aim: This systematic review aims to summarize evidence on correlates of fundamental motor skills in typically developing children aged 0–4 years. Methods: A literature search (PubMed, Embase, PsycINFO, and SPORTDiscus) was performed from 2000 till 23 May 2022. Inclusion criteria was cross-sectional and prospective studies examining associations between a potential correlate and fundamental motor skills in typically developing, apparently healthy children aged 0–4 years. Two independent reviewers performed screening and methodological quality assessment. Results: Eighty-three studies met eligibility criteria and were included. Thirteen studies were of high methodological quality. In children aged &lt;1 year, we found no evidence for family income, breastfeeding-related, sleep-related, home environment, and socioeconomic variables. In children aged 1–2 years, we found no evidence for sex, growth-related variables, singleton birth, and family income. In children aged 2–4 years, we found no evidence for screen behavior, toxicity, parental education, family income, socioeconomic variables, and maternal depression/anxiety and moderate evidence for a positive association with early childhood education and care setting type. For other examined correlates, we found insufficient evidence (inconsistent findings or only one study available). Conclusions: We found insufficient evidence for over half of examined potential correlates of fundamental motor skills. We recommend investing in better research methodologies and improved reporting.

Late bedtime combined with more screen time before bed increases the risk of obesity and lowers diet quality in Spanish children

This cross-sectional study aimed to investigate whether the combination of bedtime and screen time (ST) before bed were associated with obesity and diet quality in toddlers and school-aged children. Parents reported children's bedtimes and ST before bed (0 min, 1–30 min, >30 min). We then defined bed + screen time behavior using bedtime median cut-offs (early [EB] or late [LB]) and ST responses, resulting in four groups: EB–0′ST, EB ≤ 30′ST/LB–0′ST, EB > 30′ST/LB ≤ 30′ST, and LB > 30′ST. For all participants (n = 1133; 5.4 ± 2.7 years, 49.7% girls, 51.9% school-aged) we evaluated body mass index (BMI), diet quality, sleep-related variables, physical activity, and health-related quality of life (HRQoL). Outcome variables were compared across bed + screen time behavior groups, stratified by age group (toddlers and school-aged children) using general linear models for continuous variables, as well as chi-squared tests or logistic regressions for categorical variables. Additionally, we calculated linear p-trends. Analyses were adjusted for sociodemographic variables, BMI, and physical activity (unless the variable was tested). The results showed that toddlers and school-aged children in the LB ≥ 30′ST group were more likely to have overweight/obesity (OR: 3.42 [95%CI:1.41,8.26] and OR: 2.53 [95%CI:1.10,5.03], respectively) than those in the EB–0′ST group. Additionally, toddlers and school-aged children in the EB > 30′ST/LB ≤ 30′ST and LB > 30′ST groups showed significantly lower adherence to the Mediterranean diet compared to the other groups (p < 0.001). Regarding sleep-related outcomes, we observed that the combination of LB and more ST was associated with poorer sleep quality and shorter sleep duration in toddlers and school-aged children (p < 0.001). These findings emphasize the importance of promoting earlier bedtimes and limiting ST before bed as part of obesity prevention strategies for children. Furthermore, such intervention could benefit the quality of children's diet and overall lifestyle.

Shorter self-reported sleep duration is associated with worse virtual spatial navigation performance in men.

Sleep has been shown to impact navigation ability. However, it remains unclear how different sleep-related variables may be independently associated with spatial navigation performance, and as to whether gender may play a role in these associations. We used a mobile video game app, Sea Hero Quest (SHQ), to measure wayfinding ability in US-based participants. Wayfinding performance on SHQ has been shown to correlate with real-world wayfinding. Participants were asked to report their sleep duration, quality, daytime sleepiness and nap frequency and duration on a typical night (n = 766, 335 men, 431 women, mean age = 26.5years, range = 18-59years). A multiple linear regression was used to identify which self-reported sleep variables were independently associated with wayfinding performance. Shorter self-reported sleep durations were significantly associated with worse wayfinding performance in men only. Other self-reported sleep variables showed non-significant trends of association with wayfinding performance. When removing non-typical sleepers (< 6 or > 9h of sleep on a typical night), the significant association between sleep duration and spatial navigation performance in men was no longer present. These findings from U.S.-based participants suggest that a longer self-reported sleep duration may be an important contributor to successful navigation ability in men.

Associations of sleep-related variables with reverse dipping patterns of blood pressure in α-synucleinopathies

IntroductionThe reverse dipping blood pressure (BP) pattern is very common in α-synucleinopathies. We aimed to explore the associations of sleep-related variables with abnormal BP circadian rhythms in Parkinson's disease (PD) and multiple system atrophy (MSA). MethodsA total of 126 patients, 76 with PD and 50 with MSA, were included. All participants underwent ambulatory BP monitoring and full-night polysomnography (PSG). We analyzed abnormal dipping patterns and sleep-related parameters, including moderate to severe obstructive sleep apnea (OSA), rapid eye movement behavior disorder (RBD), average oxygen saturation (SaO2%), lowest SaO2%, duration of SaO2% <90%, and apnea-hypopnea index (AHI). Binary logistic regression was performed to explore the associations between paraclinical variables, sleep-related variables, and reverse dipping patterns. ResultsReverse dipping patterns were predominant in patients with PD (58.5 %) and MSA (68.0 %). Patients with MSA had higher AHI, RBD, and lower average SaO2% than those with PD. Taking both diseases together as a whole group of α-synucleinopathies, logistic regression analysis indicates the Hoehn-Yahr stage (odds ratio [OR] = 2.00 for reverse systolic and 2.34 for reverse diastolic dipping patterns), moderate to severe OSA (OR = 2.71 for reverse systolic and 2.53 for reverse diastolic dipping patterns), average SaO2% (OR = 1.35 for reverse systolic dipping patterns), and male sex (OR = 2.70 for reverse diastolic dipping patterns) were independently associated with reverse dipping patterns. ConclusionsReverse dipping patterns were common in patients with PD and MSA. Hoehn-Yahr stage, moderate to severe OSA, average SaO2%, and male sex were associated with reverse dipping patterns in α-synucleinopathy.

Development and validation of the Japanese version of the Bedtime Procrastination Scale (BPS-J)

BackgroundThe average sleep duration of Japanese people is shorter than that of people from other countries, and bedtime procrastination is suspected to be one of the factors contributing to this issue. This study aimed to develop and validate the Japanese version of the Bedtime Procrastination Scale (BPS-J).MethodsThe BPS-J was developed through procedures including the translation and back-translation of the scale, cognitive interviews with 100 participants who reported having experiences of being diagnosed with insufficient sleep syndrome (ISS) or receiving treatment for ISS using open-ended online questionnaires, and expert checking. To investigate the scale’s validity and reliability, an online survey was conducted with daytime workers aged 20 − 65 years without a history of sleep disorders other than ISS. Half the participants were retested using the same survey after 14 days. Participants’ responses to the Brief Self-Control Scale (BSCS), General Procrastination Scale (GPS), and Munich ChronoType Questionnaire (MCTQ), and data on sleep-related variables such as sleep duration on workdays and the days per week of fatigue or sleep loss, sex, and age, were collected.ResultsWe analyzed data from 574 participants to assess scale validity. We then analyzed data from 280 participants to determine test–retest reliability. Confirmatory factor analyses revealed that the two-factor model without Item 2 was most suitable for the BPS-J, unlike other language versions. Regardless of the full-item model or the model with Item 2 eliminated, sufficient reliability and significant correlations with the BSCS, GPS, MCTQ, and sleep-related variables such as sleep duration per night on work days, days per week of feeling fatigued, and days per week of sleep loss were observed. Logistic and linear regressions showed that the relationships between the BPS-J, sleep-related variables, and MCTQ were maintained after adjusting for sex and age.ConclusionThe BPS-J had sufficient validity and reliability. Further, eliminating Item 2 from the original version of the BPS strengthened the ability to survey Japanese daytime workers.

Sleep disturbances and progression of mobility disability: Longitudinal findings from the Nurses’ Health Study

ObjectiveTo examine longitudinal associations between self-reported sleep disturbances and mobility disability progression among women, including subgroups with multiple sclerosis (MS), diabetes, and osteoarthritis (OA). MethodsProspective cohort study using data from Nurses’ Health Study long-form questionnaires (2008, 2012, 2014, 2016). Logistic regression was used to quantify associations between sleep-related variables at baseline and subsequent increase in mobility disability. ResultsOf 70,303 women (mean age 73), 392 had MS, 7,302 had diabetes, and 24,099 had OA. Between 2008–2016, mobility disability increased by 16.9 % overall, 27.8 % in the MS subgroup, 27.0 % in the diabetes subgroup, and 23.7 % in the OA subgroup. Known/suspected obstructive sleep apnea was significantly associated with an increase in mobility disability between 2008 and 2016, overall (OR:1.4, 95 %CI:1.2,1.5), and in the diabetes (OR:1.5, 95 %CI:1.2,1.9) and OA subgroups (OR:1.2, 95 %CI:1.0,1.4), but not in the MS subgroup (OR:2.3, 95 %CI:0.6,8.9); however, across 2012–2016, this association was significant for MS (OR:4.0, 95 %CI:1.0,16.1). Suboptimal sleep duration was significantly associated with increased odds of mobility disability progression overall, but not in disease subgroups. Perception of adequate sleep was associated with lower odds of mobility disability progression overall (OR:0.82, 95 %CI:0.78,0.87) and for the OA subgroup (OR:0.83, 95 %CI:0.76,0.91). Excessive daytime sleepiness was associated with mobility disability progression overall (OR:1.2, 95 %CI:1.1,1.4) and for the OA subgroup (OR:1.2, 95 %CI:1.0,1.4). ConclusionsPrevalent sleep disturbances could increase disability progression among women. Chronic disease populations may be uniquely vulnerable. Informed by these data, future research could offer new insight into sleep-based strategies to ameliorate mobility decline.

Temporal trends in sleep pattern among Chinese adults between 2010 and 2018: findings from five consecutive nationally representative surveys

ObjectivesThis study aimed to comprehensively analyze the time trends in average sleep duration and prevalence of short sleep, poor sleep quality, and high sleep debt among Chinese adults. Study designThis was a cross-sectional study. MethodsThe study used nationally representative data from Chinese Family Panel Survey (CFPS) among adults aged ≥18 years. Linear regression and logistic regression were used to calculate P-values for trends across waves, and absolute difference in prevalences were calculated by linear regression. Poisson regression analysis was used to calculate the prevalence ratios of sleep-related problems. ResultsIn 2018, the estimated average sleep duration in adults was 7.6 h/d. A shorter sleep duration, higher proportion of short sleep, and poor sleep quality were observed in people aged ≥65 years, women, people with primary school education or below, and residents in Liaoning province. The average sleep duration slightly decreased from 8.2 h/d in 2010 to 7.6 h/d in 2016, and then remained stable from 2016 to 2018. The prevalence of short sleep duration has markedly increased from 11.8% in 2010 to 24.1% in 2016, and then there was a decline in prevalence from 2016 to 2018, although this decrease was not significant. The prevalence of high sleep debt among employed people increased from 6.2% in 2010 to 8.6% in 2018 (absolute difference, 2.4 p.p; P trend = 0.063). In addition, the prevalence of poor sleep quality increased from 15.6% in 2012 to 21.3% in 2018 (absolute difference of 5.7 p.p; P trend<0.001). For all the sleep-related variables, the degree of changes varied by sociodemographic subgroups. ConclusionsIn this nationally representative survey of the Chinese population, the average sleep duration slightly decreased from 2010 to 2016, and then remained stable from 2016 to 2018. Poor sleep quality, and high sleep debt increased among most of the sociodemographic subgroups. Future studies are needed to understand the drivers of changes in sleep health among Chinese adults.