Hot flashes and sleep disruption in a randomized trial in menopausal women.

BACKGROUND: Hot flashes, common during menopause, affect up to 80% of the Western menopausal women and are reported to contribute to sleep disturbances in midlife. Few prospective data are available to confirm the specific role of hot flashes in disrupting sleep in midlife women, however, or confirm whether changes in hot flashes in response to clinical therapies result in improvement in sleep. OBJECTIVE: To examine the effects of continuous nitroglycerin therapy on sleep quality in perimenopausal and postmenopausal women with frequent hot flashes (pre-specified secondary trial endpoint) and to examine prospective associations between hot flashes and sleep disruption in this population. STUDY DESIGN: Sleep data were analyzed from a randomized, double-blinded, placebo-controlled trial of continuous transdermal nitroglycerin (NTG) therapy to suppress nitric oxide-mediated vasodilation in perimenopausal or postmenopausal women with hot flashes. Participants were randomized to uninterrupted use of transdermal NTG (0.2-0.6 mg/hour) or placebo for 12 weeks. Nocturnal hot flashes awakening participants from sleep were evaluated using 7-day symptom diaries at baseline, 5 weeks, and 12 weeks. Sleep disruption (wakefulness after sleep onset, WASO) was assessed using validated sleep diaries, and global sleep quality was assessed by the validated Pittsburgh Sleep Quality Index (PSQI: range 0 [best] 21 [worst]) questionnaire. Mixed linear models examined changes in sleep quality and disruption, as well as the strength of associations between nocturnal hot flash frequency and sleep outcomes, over 5 and 12 weeks, adjusting for baseline values, age, race, and ethnicity. RESULTS: Among the 141 participants (70 to NTG and 71 to placebo, mean age 54.6 [±3.9] years), the mean baseline hot flash frequency was 10.8 (±3.5) per day, including 2.6 (±1.7) nocturnal hot flashes awakening participants. At baseline, hot flashes were the most commonly reported reason for nocturnal awakening, with 62.6% of participants reporting waking due to hot flashes at least twice nightly. Over 5 and 12 weeks, mean frequency of nocturnal hot flashes causing awakenings decreased in both groups (NTG: -0.9 episodes/night, placebo: -1.0 episodes/night). Sleep disruption as measured by average nightly WASO also decreased (NTG: -10.1 minutes, placebo: -7.3 minutes), and mean PSQI score improved (NTG: -1.3 points, placebo: -1.2 points). No significant between-group differences in change in sleep outcomes were detected from baseline to 5 and 12 weeks, including PSQI sleep quality score as a prespecified secondary trial endpoint (P≥.05 for all). Greater improvement in nocturnal hot flash frequency over 5 and 12 weeks was associated with greater improvement in PSQI sleep quality score (ß= -0.30, P=.01) and sleep disruption reflected by WASO (ß= -1.88, P=.02) in the combined sample. CONCLUSION: Among menopausal women in a randomized trial of continuous NTG therapy for hot flashes, hot flashes were the most frequently reported cause of nocturnal awakenings. Compared to placebo, continuous NTG therapy did not result in greater improvements in sleep quality from baseline to 5 and 12 weeks. Based on night-by-night symptom diaries and questionnaires, however, greater improvement in nocturnal hot flash frequency in both groups was associated with greater improvement in sleep quality and disruption.

Electroencephalography Microstate Class D is a Brain Marker of Subjective Sleep Quality for College Students with High Habitual Sleep Efficiency.

Subjective sleep quality is an individual's subjective sleep feeling, and its effective evaluation is the premise of improving sleep quality. However, people with autism or mental disorders often experience difficulties in verbally expressing their subjective sleep quality. To solve the above problem, this study provides a non-verbal and convenient brain feature to assess subjective sleep quality. Reportedly, microstates are often used to characterize the patterns of functional brain activity in humans. The occurrence frequency of microstate class D is an important feature in the insomnia population. We therefore hypothesize that the occurrence frequency of microstate class D is a physiological indicator of subjective sleep quality. To test this hypothesis, we recruited college students from China as participants [N = 61, mean age = 20.84 years]. The Chinese version of the Pittsburgh Sleep Quality Index scale was used to measure subjective sleep quality and habitual sleep efficiency, and the state characteristics of the brain at this time were assessed using closed eyes resting-state brain microstate class D. The occurrence frequency of EEG microstate class D was positively associated with subjective sleep quality (r = 0.32, p < 0.05). Further analysis of the moderating effect showed that the occurrence frequency of microstate class D was significantly and positively correlated with subjective sleep quality in the high habitual sleep efficiency group. However, the relationship was not significant in the low sleep efficiency group (ßsimple = 0.63, p < 0.001). This study shows that the occurrence frequency of microstate class D is a physiological indicator of assessing subjective sleep quality levels in the high sleep efficiency group. This study provides brain features for assessing subjective sleep quality of people with autism and mental disorders who cannot effectively describe their subjective feelings.

Pharmacologic Sleep Aids in the Intensive Care Unit: A Systematic Review.

Background: Patients in the intensive care unit (ICU) often experience poor sleep quality. Pharmacologic sleep aids are frequently used as primary or adjunctive therapy to improve sleep, although their benefits in the ICU remain uncertain. This review aims to provide a comprehensive assessment of the objective and subjective effects of medications used for sleep in the ICU, as well as their adverse effects. Methods: PubMed, Web of Science, Scopus, Embase, and Cochrane Central Register of Controlled Trials were systematically searched from their inception until June 2023 for comparative studies assessing the effects of pharmacologic sleep aids on objective and subjective metrics of sleep. Results: Thirty-four studies with 3498 participants were included. Medications evaluated were melatonin, ramelteon, suvorexant, propofol, and dexmedetomidine. The majority of studies were randomized controlled trials. Melatonin and dexmedetomidine were the best studied agents. Objective sleep metrics included polysomnography (PSG), electroencephalography (EEG), bispectral index, and actigraphy. Subjective outcome measures included patient questionnaires and nursing observations. Evidence for melatonin as a sleep aid in the ICU was mixed but largely not supportive for improving sleep. Evidence for ramelteon, suvorexant, and propofol was too limited to offer definitive recommendations. Both objective and subjective data supported dexmedetomidine as an effective sleep aid in the ICU, with PSG/EEG in 303 ICU patients demonstrating increased sleep duration and efficiency, decreased arousal index, decreased percentage of stage N1 sleep, and increased absolute and percentage of stage N2 sleep. Mild bradycardia and hypotension were reported as side effects of dexmedetomidine, whereas the other medications were reported to be safe. Several ongoing studies have not yet been published, mostly on melatonin and dexmedetomidine. Conclusions: While definitive conclusions cannot be made for most medications, dexmedetomidine improved sleep quantity and quality in the ICU. These benefits need to be balanced with possible hemodynamic side effects.

Measurement of peripheral arterial tone to detect sleep-disordered breathing in patients with heart failure.

PURPOSE: Sleep-disordered breathing is highly prevalent in patients with heart failure and is related to increased mortality and morbidity. The gold standard for sleep diagnostic is polysomnography in a sleep laboratory. Measurement of peripheral arterial tone with a wrist-worn diagnostic device is a promising method to detect sleep-disordered breathing without major technical effort. METHODS: We prospectively enrolled patients with heart failure with reduced ejection fraction for measurement of the peripheral arterial tone and polysomnography simultaneously during one night in the sleep laboratory. Raw data of polysomnography was analyzed blindly by sleep core lab personnel and compared with automatic algorithm-based sleep results of measurement of the peripheral arterial tone. RESULTS: A total of 25 patients provided comparable sleep results. All patients had sleep-disordered breathing and were identified by measurement of the peripheral arterial tone. The comparison of apnea-hypopnea index between peripheral arterial tone 38.8 ± 17.4/h and polysomnography 44.5 ± 17.9/h revealed a bias of - 5.7 ± 9.8/h with limits of agreement of ± 19.2/h in Bland-Altman analysis but showed high and significant Pearson correlation (r = 0.848, p < 0.001). CONCLUSION: The findings suggest that measurement of the peripheral arterial tone may be useful to identify sleep-disordered breathing in patients with heart failure with reduced ejection fraction.

Association between obstructive sleep apnea and gastroesophageal reflux disease: A systematic review and meta-analysis.

BACKGROUND AND AIM: We aim to conduct a systematic review and determine the association between obstructive sleep apnea (OSA) and gastroesophageal reflux disease (GERD). METHODS: Literature search for eligible studies was performed across major databases. The main endpoint was to assess the association between GERD and OSA. Subgroup analyses were performed to determine this strength of the association stratified by the diagnostic tools used for OSA (nocturnal polysomnogram or Berlin questionnaire) and GERD (validated reflux questionnaire or esophagogastroduodenoscopy). We also compared sleep efficiency, apnea hypopnea index, oxygen desaturation index, and Epworth Sleepiness Scale in OSA patients with or without GERD. Results were pooled together using Reviewer Manager 5.4. RESULTS: Six studies involving 2950 patients with either GERD or OSA were included in the pooled analysis. Our findings suggest that there was a statistically significant unidirectional association between GERD and OSA (odds ratio [OR] = 1.53, P = 0.0001). Subgroup analyses redemonstrated an OSA-GERD association irrespective of the tools used for diagnosing either GERD or OSA (P = 0.24 and P = 0.82, respectively). Sensitivity analyses demonstrated the same association after controlling for gender (OR = 1.63), BMI (OR = 1.81), smoking (OR = 1.45), and alcohol consumption (OR = 1.79). In patients with OSA, there were no statistically significant differences between patients with or without GERD in terms of apnea hypopnea index (P = 0.30), sleep efficiency (P = 0.67), oxygen desaturation index (P = 0.39), and Epworth Sleepiness Scale (P = 0.07). CONCLUSION: There exists an association between OSA and GERD that is independent of the modalities used for screening or diagnosing both disorders. However, the presence of GERD did not affect the severity of OSA.

Spinning Your Wheels: Psychological Overinvolvement and Actigraphy-Assessed Sleep Efficiency Following Marital Separation.

BACKGROUND: This study investigated the ways in which adults reflect on their psychological experiences amid a recent marital separation and how these patterns of thought, manifest in language, are associated with self-reported negative affect and actigraphy-assessed sleep disturbance. METHODS: In a sample of 138 recently separated adults assessed three times over five months, we examined within- and between-person associations among psychological overinvolvement (operationalized using verbal immediacy derived as a function of the language participants used to discuss their relationship history and divorce experience), continued attachment to an ex-partner, negative affect, and sleep efficiency. RESULTS: The association between psychological overinvolvement and negative affect operated at the within-person level, whereas the associations between psychological overinvolvement and sleep disturbance, as well as negative affect and sleep disturbance, operated at the between-person level. CONCLUSIONS: These findings shed light on the intraindividual processes that may explain why some people are more susceptible to poor outcomes after separation/divorce than others. Our findings suggest that individuals who express their divorce-related thoughts and feelings in a psychologically overinvolved manner may be at greatest risk for sleep disturbances after marital separation/divorce.

A Delayed Evening Meal Enhances Sleep Quality in Young Rugby Players.

The aim of this study was to examine the effect of delayed evening mealtime on sleep quality in young athletes. Twelve rugby players (age 15.8 ± 0.7 years) participated in a crossover within-participant design. Adolescents spent five consecutive days in each of two conditions, separated by a 2-week washout period: routine dinner (3.5 hr before bedtime) and late dinner (LD, 1.5 hr before bedtime). Other mealtimes as well as bedtime and wake-up time were usual and remained the same in both conditions. Their schedules, dietary intakes, and physical activity were controlled and kept constant throughout the study. Sleep was assessed using polysomnography on the first and the last nights in the individual rooms of the boarding school. An increase in total sleep time by 24 min (p = .001, d = 1.24) and sleep efficiency by 4.8% was obtained during LD (p = .001, d = 1.24). Improvement in sleep efficiency was mainly due to a lower wake after sleep onset (-25 min, p = .014, d = -3.20), a decrease of microarousals (-25%, p = .049, d = -0.64), and awakenings ≥90 s (-30%, p < .01, d = -0.97) in LD compared to routine dinner. There were no significant differences in sleep architecture except for a shorter slow-wave sleep (N3) latency (-6.9 min, p = .03, d = -0.778) obtained during LD. In this study, evening dinner 1.5 hr before bedtime leads to better quality and less fragmented sleep compared to evening dinner 3.5 hr before bedtime in young athletes.

Exploring the Potential of Pulse Transit Time as a Biomarker for Sleep Efficiency through a Comparison Analysis with Heart Rate and Heart Rate Variability.

The relationship between sleep dynamics and blood pressure (BP) changes is well established. Moreover, sleep efficiency and wakefulness during sleep (WASO) events have a significant impact on BP dipping. Despite this knowledge, there is limited research on the measurement of sleep dynamics and continuous blood pressure (CBP). This study aims to explore the relationship between sleep efficiency and cardiovascular function indicators such as pulse transit time (PTT), as a biomarker of CBP, and heart rate variability (HRV), measured using wearable sensors. The results of the study conducted on 20 participants at the UConn Health Sleep Disorders Center suggest a strong linear relationship between sleep efficiency and changes in PTT (r2 = 0.8515) and HRV during sleep (r2 = 5886). The findings of this study contribute to our understanding of the relationship between sleep dynamics, CBP, and cardiovascular health.

Attentional Control Accounts for the Association Between Anxiety Sensitivity and Sleep Efficiency in Clinic-Referred Youth.

Youth with anxiety disorders report difficulty falling asleep and returning to sleep after sleep onset (i.e., poor sleep efficiency). Anxiety sensitivity, the excessive attention to physical symptoms of anxiety and their threatening interpretations, has been linked to poor sleep efficiency. We tested a conceptual model wherein attentional control, attentional focusing and attentional shifting would account for the relationship between anxiety sensitivity and poor sleep efficiency. 255 youths (6-17 years old, 78% Hispanic/Latino) who presented to a university-based research clinic completed measures on anxiety sensitivity, sleep, and attentional control. Poorer sleep efficiency was significantly correlated with higher anxiety sensitivity and lower attentional control, attentional focusing, and attentional shifting. Higher anxiety sensitivity was significantly correlated with lower attentional control and attentional focusing. Attentional control and attentional focusing, not attentional shifting, accounted for the relationship between anxiety sensitivity and poor sleep efficiency. These findings identify attentional control and attentional focusing as variables that may explain the association between anxiety sensitivity and sleep efficiency in youth.

Specific Sleep Health Domains as Predictors of Executive Function in Older Adults.

OBJECTIVES: Sleep health and executive function are multifaceted constructs that decline with age. Some evidence suggests that poor sleep health may underlie declines in executive function, but this relationship is not consistently found in cognitively normal older adults. The authors systematically investigated distinct sleep health domain associations with specific aspects of executive function. METHODS: Community-dwelling older adults completed clinical interviews, comprehensive neuropsychological assessments, and subjective sleep measures. Four sleep health domains were investigated: satisfaction/quality, sleep efficiency, sleep duration, and daytime sleepiness/fatigue. Hierarchical multiple regression analyses, adjusting for significant covariates, examined whether the sleep health domains differentially predicted executive function. RESULTS: Separate analyses found that greater sleep efficiency was associated with better response inhibition, while greater daytime sleepiness/fatigue was associated with worse cognitive flexibility. Categorical differences in sleep duration indicated that average durations, compared with short and long durations, had better executive function performance across measures. Sleep satisfaction/quality was not statistically associated with executive function. CONCLUSIONS: These findings have implications for sleep assessment and its intervention. Routine screening of sleep duration, efficiency, and daytime fatigue may be particularly useful in identifying those at greater risk of executive dysfunction. Targeting specific problems in sleep may serve to improve cognitive control and efficiency in older adults. Future research is warranted to establish the optimal hours of sleep duration for cognitive health.

Sleep duration and efficiency are associated with plasma amyloid-ß in non-demented older people.

STUDY OBJECTIVES: This study aims to investigate the extent to which sleep duration and efficiency are associated with plasma amyloid-ß (Aß) levels in non-demented older people. METHODS: This study is a cross-sectional analysis of 305 non-demented older people. Sleep duration and efficiency were assessed used the Pittsburgh Sleep Quality Index. Levels of plasma Aß were determined by sandwich enzyme-linked immunosorbent assay technique. Associations between sleep variables and plasma Aß levels were evaluated with multivariable linear regression analysis. RESULTS: Compared to those with sleep duration > 7 h, participants with sleep duration < 6 h had a higher plasma Aß42 level (ß = 0.495, 95% CI 0.077~0.913, p = 0.021) and Aß42/Aß40 ratio (ß = 0.101, 95% CI 0.058~0.144, p < 0.001). Compared to those with sleep efficiency ≥ 85%, participants with lower sleep efficiency (65~74%, <65%) had a higher level of plasma Aß42 (<65%: ß = 0.627, 95% CI 0.147~1.108, p = 0.011) and Aß42/Aß40 ratio (65~74%: ß = 0.052, 95% CI 0.007~0.097, p = 0.026; <65%: ß = 0.117, 95% CI 0.067~0.168, p < 0.001). CONCLUSIONS: These findings indicated that short sleep duration and low sleep efficiency were associated with a high level of Aß42. A better comprehending of the link between sleep and plasma Aß levels may lead to effective sleep-based intervention to reduce the risk of Alzheimer's disease.

Respiratory muscle endurance training improves exercise performance but does not affect resting blood pressure and sleep in healthy active elderly.

PURPOSE: Ageing is associated with increased blood pressure (BP), reduced sleep, decreased pulmonary function and exercise capacity. The main purpose of this study was to test whether respiratory muscle endurance training (RMET) improves these parameters. METHODS: Twenty-four active normotensive and prehypertensive participants (age: 65.8 years) were randomized and balanced to receive either RMET (N = 12) or placebo (PLA, N = 12). RMET consisted of 30 min of volitional normocapnic hyperpnea at 60% of maximal voluntary ventilation while PLA consisted of 1 inhalation day-1 of a lactose powder. Both interventions were performed on 4-5 days week-1 for 4-5 weeks. Before and after the intervention, resting BP, pulmonary function, time to exhaustion in an incremental respiratory muscle test (incRMET), an incremental treadmill test (IT) and in a constant-load treadmill test (CLT) at 80% of peak oxygen consumption, balance, sleep at home, and body composition were assessed. Data was analyzed with 2 × 2 mixed ANOVAs. RESULTS: Compared to PLA, there was no change in resting BP (independent of initial resting BP), pulmonary function, IT performance, sleep, body composition or balance (all p > 0.05). Performance significantly increased in the incRMET (+ 6.3 min) and the CLT (+ 3.2 min), resulting in significant interaction effects (p < 0.05). CONCLUSION: In the elderly population, RMET might be used to improve respiratory and whole body endurance performance either as an adjunct to physical exercise training or as a replacement thereof for people not being able to intensively exercise even if no change in BP or sleep may be expected.

Sleep/waketime preference and delayed diurnal eating rhythms are associated through light exposure timing and modified by sleep efficiency.

Delayed eating rhythms, relative to the sleep/wake period, commonly manifest as a lack of hunger in the morning (morning anorexia) and elevated hunger in the late evening (evening hyperphagia). These intake patterns are associated with adverse mental and physical health outcomes. We aimed to evaluate whether the timing of light exposure, an important environmental signal for circadian synchronization, explains the link between sleep/waketime preferences and delayed diurnal appetite. We also aimed to test whether disruptions in sleep quality, reflecting suboptimal circadian synchronization, identify individuals for whom sleep/waketime preference is associated with delayed diurnal appetite. Participants (N = 150) completed a measure of their sleep/waketime preferences and wore a device to capture their sleep efficiency and naturalistic light exposure for 48 consecutive hours. The timing of light exposure mediated the link between sleep/waketime preferences and evening hyperphagia, but not morning anorexia, such that a later peak in light exposure mitigated some of the risk for evening hyperphagia that was associated with later sleep/waketime preferences. Sleep efficiency moderated the association between sleep/waketime preference and morning anorexia, but not evening hyperphagia. Earlier sleep/waketime preference was associated with less morning anorexia among individuals with high sleep efficiency, but morning anorexia was consistently elevated among individuals with poor sleep efficiency. These results on the relation between sleep/waketime preference and two aspects of delayed diurnal appetite suggest that morning anorexia depends on sleep efficiency and evening hyperphagia may be influenced by the timing of daily light exposure. Future research should assess over longer periods, covering weekdays and weekends, and incorporate momentary reports of meals/snacks and appetite.

Sleep Disturbance and Quality of Life in Rheumatoid Arthritis: Prospective mHealth Study.

BACKGROUND: Sleep disturbances and poor health-related quality of life (HRQoL) are common in people with rheumatoid arthritis (RA). Sleep disturbances, such as less total sleep time, more waking periods after sleep onset, and higher levels of nonrestorative sleep, may be a driver of HRQoL. However, understanding whether these sleep disturbances reduce HRQoL has, to date, been challenging because of the need to collect complex time-varying data at high resolution. Such data collection is now made possible by the widespread availability and use of mobile health (mHealth) technologies. OBJECTIVE: This mHealth study aimed to test whether sleep disturbance (both absolute values and variability) causes poor HRQoL. METHODS: The quality of life, sleep, and RA study was a prospective mHealth study of adults with RA. Participants completed a baseline questionnaire, wore a triaxial accelerometer for 30 days to objectively assess sleep, and provided daily reports via a smartphone app that assessed sleep (Consensus Sleep Diary), pain, fatigue, mood, and other symptoms. Participants completed the World Health Organization Quality of Life-Brief (WHOQoL-BREF) questionnaire every 10 days. Multilevel modeling tested the relationship between sleep variables and the WHOQoL-BREF domains (physical, psychological, environmental, and social). RESULTS: Of the 268 recruited participants, 254 were included in the analysis. Across all WHOQoL-BREF domains, participants' scores were lower than the population average. Consensus Sleep Diary sleep parameters predicted the WHOQoL-BREF domain scores. For example, for each hour increase in the total time asleep physical domain scores increased by 1.11 points (ß=1.11, 95% CI 0.07-2.15) and social domain scores increased by 1.65 points. These associations were not explained by sociodemographic and lifestyle factors, disease activity, medication use, anxiety levels, sleep quality, or clinical sleep disorders. However, these changes were attenuated and no longer significant when pain, fatigue, and mood were included in the model. Increased variability in total time asleep was associated with poorer physical and psychological domain scores, independent of all covariates. There was no association between actigraphy-measured sleep and WHOQoL-BREF. CONCLUSIONS: Optimizing total sleep time, increasing sleep efficiency, decreasing sleep onset latency, and reducing variability in total sleep time could improve HRQoL in people with RA.

Physiological sleep measures predict time to 15-year mortality in community adults: Application of a novel machine learning framework.

Clarifying whether physiological sleep measures predict mortality could inform risk screening; however, such investigations should account for complex and potentially non-linear relationships among health risk factors. We aimed to establish the predictive utility of polysomnography (PSG)-assessed sleep measures for mortality using a novel permutation random forest (PRF) machine learning framework. Data collected from the years 1995 to present are from the Sleep Heart Health Study (SHHS; n = 5,734) and the Wisconsin Sleep Cohort Study (WSCS; n = 1,015), and include initial assessments of sleep and health, and up to 15 years of follow-up for all-cause mortality. We applied PRF models to quantify the predictive abilities of 24 measures grouped into five domains: PSG-assessed sleep (four measures), self-reported sleep (three), health (eight), health behaviours (four), and sociodemographic factors (five). A 10-fold repeated internal validation (WSCS and SHHS combined) and external validation (training in SHHS; testing in WSCS) were used to compute unbiased variable importance metrics and associated p values. We observed that health, sociodemographic factors, and PSG-assessed sleep domains predicted mortality using both external validation and repeated internal validation. The PSG-assessed sleep efficiency and the percentage of sleep time with oxygen saturation <90% were among the most predictive individual measures. Multivariable Cox regression also revealed the PSG-assessed sleep domain to be predictive, with very low sleep efficiency and high hypoxaemia conferring the highest risk. These findings, coupled with the emergence of new low-burden technologies for objectively assessing sleep and overnight oxygen saturation, suggest that consideration of physiological sleep measures may improve risk screening.

Relationships of physical activity and sedentary behaviour with the previous and subsequent nights' sleep in children and youth: A systematic review and meta-analysis.

The interrelationships between sleep and daytime movement behaviours have been examined at interindividual level. Studies of within-person, temporal relationships of daytime physical activity (PA) and sedentary behaviour with the previous and subsequent nights' sleep are increasing. The present systematic review and meta-analysis synthesised the results of studies in school-aged children and youth. Eight databases (MEDLINE, PsycINFO, EMBASE, Global Health, PubMed, Web of Science, SPORTDiscus, and CINAHL) were searched for peer-reviewed articles that examined the association between daytime movement behaviours (including PA, sedentary time, or sedentary recreational screen time) and night-time sleep on the same day, or the association between night-time sleep and daytime movement behaviours the next day, in children and youth. A total of 11 studies comprising 9,622 children and youth aged 5-15 years met the inclusion criteria. Sedentary time was negatively associated with the subsequent night's sleep duration (r = -0.12, 95% confidence interval -0.23 to -0.00; I2  = 93%; p = .04). Positive relationships between PA and the previous or subsequent night's sleep duration were observed only for studies that adjusted for accelerometer wear time. There was some evidence suggesting that a longer sleep duration was associated with less sedentary time and a higher proportion of the daytime spent being physically active and vice versa, although the association was weak and based on a limited number of studies. From a clinical perspective, promotion of either sleep hygiene or daytime PA should be planned with considerations of the virtuous or vicious circle between these behaviours and monitor concurrent effects on the others.

The influence of sleep on language production modalities in preschool children with Down syndrome.

Evidence suggests that sleep may relate to oral language production in children with Down syndrome. However, these children are capable of using complex referential gestures as a compensation strategy for problems with oral production, and those with a greater productive oral vocabulary have less gestural vocabulary. The goal of this study was to explore whether sleep quality relates to oral and gestural production modalities in children with Down syndrome. We evaluated 36 preschool children with and without Down syndrome, paired by chronological age and gender, with similar sociodemographic backgrounds, using actigraphy to measure sleep behaviour and the Communicative Development Inventory for Down syndrome to measure vocabulary. Children with Down syndrome with better sleep efficiency showed more oral production but less gestural production. These results highlight the importance of sleep quality to language learning in children with Down syndrome.

Prevalence and differences in habitual sleep efficiency, sleep disturbances, and using sleep medication: a national study of university students in Jordan.

BACKGROUND: Sleep quality has a significant impact on the physical and mental health of the young population. STUDY AIM: To evaluate sleep efficiency, sleep disturbances, and use of sleep medication among university students in Jordan and to examine differences in these problems in relation to selected demographic and health-risk behaviors. METHODS: The study used a cross-sectional design and a multi-stage sampling technique. Three public universities were randomly selected from three major governorates in Jordan. The Arabic version of the Pittsburgh Sleep Quality Index was used to measure sleep efficiency, sleep disturbances, and the use of sleep medication. Descriptive statistics and Kruskal-Wallis tests were used to analyze the data. RESULTS: Of 1308 students who participated in the study, 27% reported sleep efficiency less than 85%, 45% of the students reported nocturnal awakening, 30% reported getting up to use the bathroom, and 9% reported using medication to help sleep. Differences in sleep efficiency, sleep disturbances, and use of sleep medication were found in relation to students' gender, income, marital status, smoking status, and academic achievement. CONCLUSIONS: Poor sleep efficiency, sleep disturbances, and the use of sleep medications are significant problems affecting sleep quality among university students. Students' gender, marital status, income, smoking status, and academic achievement are important factors associated with sleep quality. IMPLICATIONS: Sleep screening among university students is required to identify and provide treatment for sleep problems. Furthermore, educating university students about the effects of smoking on health in general and on sleep in particular should be mandated.

Association between sedentary time and sleep quality based on the Pittsburgh Sleep Quality Index among South Korean adults.

BACKGROUND: Sleep problems increase the risk of premature illness and death. We evaluated the association between sedentary time and sleep quality among South Korean adults. METHODS: The data of adults (aged ≥ 19 years) from the 2018 Korea Community Health Survey were analyzed. Sedentary time, which included hours spent sitting or lying down daily, was categorized into four standardized groups. Poor sleep quality was defined using the global cutoff point (> 5 points) of the Pittsburg Sleep Quality Index. Multiple logistic regression analyses were performed to identify the association between sedentary time (≤ 3.9, 4.0-5.9, 6.0-7.9, and ≥ 8 hours /day) and sleep quality, by sex. RESULTS: Of the 224,118 participants, 35,784/100,454 men (35.6%) and 58,271/123,664 women (47.1%) had poor sleep quality. Compared with ≤ 3.9 h/day, sedentary times 4.0-5.9, 6.0-7.9, and ≥ 8 h/day were associated with worse sleep quality among men (odds ratio [OR]: 1.12, 95% confidence interval [CI]: 1.08-1.16; OR: 1.19, 95% CI: 1.14-1.25; OR: 1.30, 95% CI: 1.25-1.34, respectively) and women (OR: 1.06, 95% CI: 1.03-1.10; OR: 1.12, 95% CI: 1.08-1.16; OR: 1.22, 95% CI: 1.18-1.26, respectively). In subgroup analyses of sleep quality, subjective sleep quality, latency, disturbance, use of sleeping medication, and daytime dysfunction showed a strong dose-response relationship with increasing sedentary time in both sexes. CONCLUSIONS: Regardless of sex, the longer the sedentary time, the stronger the association with poor sleep quality. Nationwide efforts are required to recommend standards for sedentary time and develop evidenced-based healthy behavior guidelines.

The effect of evening cycling at different intensities on sleep in healthy young adults with intermediate chronobiological phenotype: A randomized, cross-over trial.

This study investigated the effect of various cycling intensities on sleep-related parameters in healthy young adults with intermediate chronobiological phenotype. Ten recreationally trained male volunteers underwent an evening i) moderate-intensity continuous training (MICT; 45 min at 70% Wmax), ii) high-intensity interval training (HIIT; 10 × 1 min at 90% Wmax), iii) sprint interval training (SIT; 6 × 20 sec at 140% Wmax) or iv) a non-exercise (CON) trial in randomized, counter-balanced and crossover order. At baseline, somatometric data, maximum oxygen uptake and chronotype were evaluated. Sleep-related indices and daily activity were recorded by a multi-sensor activity monitor. Total sleep time was longer after SIT compared to CON and MICT (p < 0.05). Sleep efficiency was higher in SIT than in CON (p < 0.05). Sleep onset latency did not differ among trials. Wake after sleep onset was decreased after SIT compared to CON (p= 0.049). No differences were found for bedtime among trials. Wake time was earlier in the MICT trial compared to CON (p = 0.026). Evening cycling exercise -independently of intensity- did not impair sleep of individuals with intermediate chronobiological phenotype. Furthermore, a single SIT session improved sleep quantity and continuation of individuals with this specific chronotype.