Cumulative Sleep Research Articles

Sleep deprivation and recovery: Endurance racing as a novel model.

The aim of this study was to investigate sleep-wake behavior and gain insights into perceived impairment (sleep, fatigue, and cognitive function) of athletes competing in two international multi-day adventure races. Twenty-four athletes took part across two independent adventure races: Queensland, Australia and Alaska, USA. Individual sleep periods were determined via actigraphy, and racers self-reported their perceived sleep disturbances, sleep impairment, fatigue and cognitive function. Each of these indices was calculated for pre-, during- and post-race periods. Sleep was severely restricted during the race period compared to pre-race (Queensland, 7:46 [0:29] vs. 2:50 [1:01]; Alaska, 7:39 [0:58] vs. 2:45 [2:05]; mean [SD], hh:mm). As a result, there was a large cumulative sleep debt at race completion, which was not 'reversed' in the post-race period (up to 1week). The deterioration in all four self-reported scales of perceived impairment during the race period was largely restored in the post-race period. This is the first study to document objective sleep-wake behaviors and subjective impairment of adventure racers, in the context of two geographically diverse, multi-day, international adventure races. Measures of sleep deprivation indicate that sleep debt was extreme and did not recover to pre-race levels within 1week following each race. Despite this objective debt continuing, perceived impairment returned to pre-race levels quickly post-race. Therefore, further examination of actual and perceived sleep recovery is warranted. Adventure racing presents a unique scenario to examine sleep, performance and recovery.

Measures of overnight oxygen saturation to characterize sleep apnea severity and predict postoperative respiratory depression

BackgroundSleep apnea syndrome, characterized by recurrent cessation (apnea) or reduction (hypopnea) of breathing during sleep, is a major risk factor for postoperative respiratory depression. Challenges in sleep apnea assessment have led to the proposal of alternative metrics derived from oxyhemoglobin saturation (SpO2), such as oxygen desaturation index (ODI) and percentage of cumulative sleep time spent with SpO2 below 90% (CT90), as predictors of postoperative respiratory depression. However, their performance has been limited with area under the curve of 0.60 for ODI and 0.59 for CT90. Our objective was to propose novel features from preoperative overnight SpO2 which are correlated with sleep apnea severity and predictive of postoperative respiratory depression.MethodsPreoperative SpO2 signals from 235 surgical patients were retrospectively analyzed to derive seven features to characterize the sleep apnea severity. The features included entropy and standard deviation of SpO2 signal; below average burden characterizing the area under the average SpO2; average, standard deviation, and entropy of desaturation burdens; and overall nocturnal desaturation burden. The association between the extracted features and sleep apnea severity was assessed using Pearson correlation analysis. Logistic regression was employed to evaluate the predictive performance of the features in identifying postoperative respiratory depression.ResultsOur findings indicated a similar performance of the proposed features to the conventional apnea–hypopnea index (AHI) for assessing sleep apnea severity, with average area under the curve ranging from 0.77 to 0.81. Notably, entropy and standard deviation of overnight SpO2 signal and below average burden showed comparable predictive capability to AHI but with minimal computational requirements and individuals’ burden, making them promising for screening purposes. Our sex-based analysis revealed that compared to entropy and standard deviation, below average burden exhibited higher sensitivity in detecting respiratory depression in women than men.ConclusionThis study underscores the potential of preoperative SpO2 features as alternative metrics to AHI in predicting postoperative respiratory.

A REM-active basal ganglia circuit that regulates anxiety

Rapid eye movement (REM) sleep has been hypothesized to promote emotional resilience, but any neuronal circuits mediating this have not been identified. We find that in mice, somatostatin (Som) neurons in the entopeduncular nucleus (EPSom)/internal globus pallidus are predominantly active during REM sleep. This unique REM activity is both necessary and sufficient for maintaining normal REM sleep. Inhibiting or exciting EPSom neurons reduced or increased REM sleep duration, respectively. Activation of the sole downstream target of EPSom neurons, Vglut2 cells in the lateral habenula (LHb), increased sleep via the ventral tegmental area (VTA). A simple chemogenetic scheme to periodically inhibit the LHb over 4days selectively removed a significant amount of cumulative REM sleep. Chronic, but not acute, REM reduction correlated with mice becoming anxious and more sensitive to aversive stimuli. Therefore, we suggest that cumulative REM sleep, in part generated by the EP → LHb → VTA circuit identified here, could contribute to stabilizing reactions to habitual aversive stimuli.

Hypocretin-1/orexin-A, sleep and excessive daytime sleepiness in patients with nonconvulsive status epilepticus: A cross-sectional cohort study

Background and objectivesNonconvulsive status epilepticus (NCSE) manifests as a change in mental status without a coma (NCSE proper) or comatose NCSE. Hypocretin-1/orexin-A (H/O) is involved in alertness and sleep maintenance. Sleep impairment and excessive daytime sleepiness (EDS) have a negative impact on cognitive functions and activities of daily living (ADL). MethodsPatients meeting the NCSE criteria underwent cerebrospinal fluid and brain magnetic resonance imaging examinations, polysomnographies (PSG), multiple latency sleep tests (MSLT), and completed Epworth Sleepiness Scale (ESS). Montreal Cognitive Assessment was used to evaluate cognitive functions, and the Barthel Index was used to assess ADL in the acute phase (V1) and three months follow-up (V2). ResultsFrom May 2020 to May 2023, we enrolled 15 patients, eight (53.3 %) women, with a median age of 69 (14) years. The median H/O CSF concentration was 250 (63.6) pg/ml; however, only three CSF samples (20 %) decreased below the borderline concentration of 200 pg/ml. Fourteen out of 15 patients (93.3 %) completed the PSG study. The median of wakefulness after sleep onset was 167 (173.5) min, sleep efficiency (SE) was 62.9 (63) %, sleep latency (SL) was 6 (32) min, REM sleep was 2.85 (7.2) %, and REM first episode latency was 210.5 (196.5) minutes. The medians of the stages N1 NREM were 4.65 (15) %, N2 NREM 68.4 (29.9) %, and N3 NREM 21.8 (35.5) %. MSLT mean latency was 7.7 (12.6) minutes. A significant negative correlation exists between H/O CSF concentrations and the stage N1 NREM (rs = −0.612, p = 0.02), and the proportion of cumulative sleep time with oxygen saturation below 90 % in total sleep time (TST) t90 (rs = −0.57, p = 0.03). MSLT had significant negative correlation with TST (rs = −0.5369, p = 0.0478), with SE (rs = −0.5897, p = 0.0265), with apnea-hypopnea index (rs = −0.7631, p = 0.0002) and with deoxygenation index (rs = −0.8009, p = 0.0006). A positive correlation exists between MSLT and SL (rs = 0.6284, p = 0.0161) and between ESS and t90 (rs = 0.9014, p = 0.0004). The correlation between H/O CSF concentrations and EDS, cognitive performance, and ADL was not proved. ConclusionsPatients after NCSE exhibited sleep impairment and excessive daytime sleepiness. Hypocretin-1/orexin-A concentrations decreased only in 20 % of these cases.

Sleep and Ultramarathon: Exploring Patterns, Strategies, and Repercussions of 1,154 Mountain Ultramarathons Finishers

BackgroundSleep and physical performance are strongly related and mutually influence each other. Athletes, particularly in disciplines like offshore sailing and ultra-endurance sports, often suffer from sleep deprivation due to factors like irregular training times, travel, and the extended duration of events like 100-mile mountain races. Despite growing interest in sleep’s role in sports science, few studies have specifically investigated the sleep patterns of ultramarathon runners. This study aimed to investigate sleep patterns and sleep management strategies in ultramarathons, and the repercussions of sleep deprivation during and after races.MethodsThis cross-sectional study using e-survey was conducted on 1154 runners from two ultramarathons (a 165 km race with 9,576 m positive elevation; 2018 finish time [23:18:48–66:04:00], and a 111 km race with 6,433 m elevation; [15:34:56 − 41:54:16]).ResultsThe results revealed that 58% of the runners reported implementing sleep management strategies before or during the race. Most runners began the race with some level of sleep debt (-50 min a week before the race). During the races, 77% of runners slept, with the cumulative sleep duration varying based on race duration and the number of nights spent on the race (76 min at 165 km and 27 min at 111 km). Short naps lasting less than 30 min were the most popular strategy. The prevalence of symptoms attributed to sleep deprivation during the race was high (80%), with reported falls and hallucinations. After the race, runners reported recovering a normal state of wakefulness relatively quickly (within two days); 22% believed that sleep deprivation during the race increased the risk of accidents in everyday life.ConclusionThis study provides valuable insights into sleep patterns and strategies in ultramarathon running and emphasizes the importance of adequate sleep management for performance and post-race recovery.

Home Is Not Always Where the Sleep Is: Effect of Home Call on Sleep, Burnout, and Surgeon Well-Being.

In-house calls contribute to loss of sleep and surgeon burnout. Although acknowledged to have an opportunity cost, home call is often considered less onerous, with minimal effects on sleep and burnout. We hypothesized home call would result in impaired sleep and increased burnout in acute care surgeons. Data from 224 acute care surgeons were collected for 6 months. Participants wore a physiological tracking device and responded to daily surveys. The Maslach Burnout Inventory was administered at the beginning and end of the study. Within-participant analyses were conducted to compare sleep, feelings of restedness, and burnout as a function of home call. One hundred seventy-one surgeons took 3,313 home calls, 52.5% were associated with getting called and 38.5% resulted in a return to the hospital. Home call without calls was associated with 3 minutes of sleep loss (p < 0.01), home call with 1 or more call resulted in a further 14 minutes of sleep loss (p < 0.0001), and home call with a return to the hospital led to an additional 70 minutes of sleep loss (p < 0.0001). All variations of home call resulted in decreased feelings of restedness (p < 0.0001) and increased feelings of daily burnout (p < 0.0001, Fig. 1). Home call is deleterious to sleep and burnout. Even home call without calls or returns to the hospital is associated with burnout. Internal assessments locally should incorporate frequency of calls and returns to the hospital when creating call schedules. Repeated nights of home call can result in cumulative sleep debt, with adverse effects on health and well-being.

Individual and cumulative firearm violence exposure: Implications for sleep among Black and American Indian/Alaska Native adults

PurposeWe investigated the relationship between various forms of firearm violence exposure and sleep problems among nationally representative samples of Black (N = 3015) and American Indian and Alaska Native (AI/AN) (N = 527) adults, focusing on difficulties falling asleep, staying asleep, and waking too early. Survey data were collected in April and May 2023. MethodsWe employed negative binomial regression models to analyze the associations between the different types of firearm violence exposure and sleep problems. We further examined associations between cumulative firearm violence exposure and sleep outcomes. ResultsA substantial proportion of Black (59%) and AI/AN (56%) adults reported experiencing some form of firearm violence exposure. Being threatened with a firearm emerged as a consistent factor associated with sleep problems for both racial groups. Witnessing or hearing about shootings was linked to sleep problems in the Black sample, while cumulative firearm violence exposure was associated with all sleep problems in both groups. ConclusionsIndividual and cumulative firearm violence exposure is associated with increased sleep problems among Black and AI/AN adults.

The Baveno Classification as a Predictor of CPAP Titration Pressure in Obstructive Sleep Apnea Syndrome.

Obstructive sleep apnea syndrome (OSAS) is a clinical condition characterised by repeated periods of partial or full obstruction of airflow throughout sleep, with impairment of the quality of life and increased mortality with socioeconomic impacts. CPAP therapy is a simple and effective treatment option for OSAS patients. To overcome the clinical and prognostic limitations of AHI-as a sole index of OSAS-the Baveno classification was recently set out and introduced into clinical practice. This study aims to analyse the effect of the Baveno classification on the optimum CPAP titration pressure. A retrospective analysis of the records of sleep studies in two centres between 2018 and 2021 was carried out. Patients diagnosed with OSAS and recruited for CPAP titration were included. Based on the Baveno classification, the patients were categorised into four groups (A, B, C, and D). Consequently, 700 patients were analysed and 427 patients were included. A significant positive correlation was detected between the CPAP optimum titration pressure and OSAS severity, neck circumference, the oxygen desaturation index (ODI), mean oxygen saturation, the AHI, the BMI, and cumulative sleep time when the SpO2 was <90% (T90) on the other side (p: <0.0001). A non-significant correlation was seen between the Epworth Sleepiness Scale (ESS), symptom severity, end organ impact, and Baveno classification of the CPAP optimum titration pressure (p: 0.8, 0.4, 0.5, and 0.7, respectively). The Baveno classification is not useful in the prediction of CPAP optimum titration pressure. However, the ODI and neck circumference were significant independent predictors of a higher CPAP titration pressure.

Cumulative sleep restriction and subsequent recovery sleep: Effects on subjective sleepiness, vigilance, and executive functions

Objective: Cumulative partial sleep loss is more often practical eventually among aircrew. The sleep loss encountered on the weekdays is generally compensated by taking restorative sleep on the weekends. This study aimed to examine the subjective appreciation of sleepiness and cognitive performance pertaining to vigilance and executive functions during cumulative sleep restriction for a period of 05 days and then following 3 consecutive nights of recovery sleep. Material and Methods: In a repeated measures design, 14 healthy volunteers were longitudinally followed up twice on a day (morning and afternoon) on their subjective sleepiness (Stanford Sleepiness Scale), vigilance, and executive functions (Mackworth Clock Test and Stroop Test of Psychometric Evaluation Design for Aviators test battery, respectively) over a period of 5 days with 2 h of sleep restriction each night. These parameters were again assessed following 3 consecutive nights of restorative recovery sleep. Results: Subjective appreciation of sleepiness was significantly increased by accumulating sleep debt (F = 8.368, P &lt; 0.001). Stroop Effect and Reaction Time did not show any significant changes; however, cumulative sleep loss significantly affected accuracy measures (F = 2.388, P = 0.04) and attention lapses (F = 2.816, P = 0.018). Following restorative sleep, the subjective sleepiness and accuracy scores did not show any significant difference from that of baseline. However, lapses continued to be significantly higher than the baseline values (P = 0.012). Conclusion: Cumulative sleep loss over a period of 5 days resulted in more sleepiness and a decrement in vigilance measures even though the executive functions remained intact. The persistence of attention lapses indicated incomplete recovery of vigilance functions following 3 days of restorative sleep.

Association between transition patterns of sleep problems and suicidal ideation in Chinese female nurses: A prospective study.

Suicidal ideation and sleep problems are both common in nurses. However, few longitudinal studies are available to examine the temporal association between sleep and suicidal ideation in nurses. Data from the Health Longitudinal Survey of Nurses in Shandong Province was analyzed, involving 623 female nurses who had completed data of concern in 2018 (T1) and 2019 (T2). Sleep problem was assessed by the Pittsburgh Sleep Quality Index, in which the transition patterns for global and specific sleep component and the cumulative number of sleep component problems were defined. Suicidal ideation was measured by the ninth item of the Patient Health Questionnaire. Binary logistic regression was used to explore the association between sleep and suicidal ideation. Chronic and deteriorated global sleep problems is associated with a greater risk of suicidal ideation. For the specific component of sleep, sleep disturbance and short sleep duration are associated with a higher risk of suicidal ideation. The higher number of cumulative sleep component problems is associated with a higher risk of suicidal ideation. Findings indicate sleep disturbance and short sleep duration may be pathways to suicidal ideation. Initiatives that target at sleep problems may be important to reduce suicidal ideation in nurses.

Exploration of Sex and Age as Moderators Between Social Cumulative Risk and Sleep in a Representative Sample of Children and Adolescents Living in the United States.

Youth who face adversity are at a disproportionate risk for poor sleep health across the life course. Identifying whether the association between adversity and poor sleep varies based upon age and sex is needed. This study aims to explore sex and age as moderators between social risk and sleep in a sample of U.S. youth. This study analyzed data of 32,212U.S. youth (6-17years) whose primary caregiver participated in the 2017-2018 National Survey of Children's Health. A social cumulative risk index (SCRI) score was calculated from 10 parental, family, and community risk indicators. Nighttime sleep duration was the number of hours the child slept during the past week. Weeknight sleep irregularity was operationalized as whether the child sometimes/rarely/never went to bed at the same time. Generalized logistic regression models estimated associations between SCRI and sleep duration/irregularity, with age and sex as moderators. Age moderated the association between SCRI and short sleep (OR = 1.12, p < 0.001), such that the magnitude of the SCRI-sleep relationship was 12% greater in school-age children. Sex was not a significant moderator. In stratified models by age group, age was positively associated with short sleep in both groups, with a greater magnitude in school-age children. Female school-age children were less likely to have short sleep than males. Younger children with greater social cumulative risk factors may be more vulnerable to short sleep duration. Further research into the mechanisms underlying the relationships between social risk and sleep health in school-age children is needed.

Exposure to indoor light at night in relation to multiple dimensions of sleep health: findings from the Sister Study.

To examine the association between light at night (LAN) and multiple sleep health dimensions. Among 47 765 Sister Study participants, indoor LAN (TV on in the room, light(s) on in room, light from outside the room, nightlight, no light) and sleep dimensions were self-reported at baseline (2003-2009). We used Poisson regression with robust variance to estimate adjusted prevalence ratios (PR) and 95% confidence intervals (CI) for the cross-sectional associations between LAN and short sleep duration (<7 hours/night), insomnia symptoms (difficulty falling or staying asleep), frequent napping (≥3 naps/week), inconsistent sleep/wake time (differed day-to-day and week-to-week), sleep debt (≥2 hours between longest and shortest duration), recent sleep medication use, and a cumulative poor sleep score (≥3 poor sleep dimensions). Population-attributable risks (PARs) were determined for any light exposure vs. none by race/ethnicity. Compared to sleeping with no light in the bedroom, sleeping with a TV on was associated with a higher prevalence of most dimensions of poor sleep (e.g. short sleep duration: PR = 1.38, 95% CI: 1.32 to 1.45; inconsistent sleep/wake time: PR = 1.55, 95% CI: 1.44 to 1.66; sleep debt: PR = 1.36, 95% CI: 1.29 to 1.44; poor sleep score: PR = 1.58, 95% CI: 1.48-1.68). PARs tended to be higher for non-Hispanic black women compared to non-Hispanic white women. Sleeping with a TV on was associated with poor sleep health among US women, and non-Hispanic black women may be disproportionately burdened.

OSA Is Associated With the Human Gut Microbiota Composition and Functional Potential in the Population-Based Swedish CardioPulmonary bioImage Study

OSA is a common sleep-breathing disorder linked to increased risk of cardiovascular disease. Intermittent upper airway obstruction and hypoxia, hallmarks of OSA, have been shown in animal models to induce substantial changes to the gut microbiota composition, and subsequent transplantation of fecal matter to other animals induced changes in BP and glucose metabolism. Does OSA in adults associate with the composition and functional potential of the human gut microbiota? We used respiratory polygraphy data from up to 3,570 individuals 50 to 64 years of age from the population-based Swedish Cardiopulmonary bioimage Study combined with deep shotgun metagenomics of fecal samples to identify cross-sectional associations between three OSA parameters covering apneas and hypopneas, cumulative sleep time in hypoxia, and number of oxygen desaturation events with gut microbiota composition. Data collection about potential confounders was based on questionnaires, onsite anthropometric measurements, plasma metabolomics, and linkage with the Swedish Prescribed Drug Register. We found that all three OSA parameters were associated with lower diversity of species in the gut. Furthermore, in multivariable-adjusted analysis, the OSA-related hypoxia parameters were associated with the relative abundance of 128 gut bacterial species, including higher abundance of Blautia obeum and Collinsella aerofaciens. The latter species was also independently associated with increased systolic BP. Furthermore, the cumulative time in hypoxia during sleep was associated with the abundance of genes involved in nine gut microbiota metabolic pathways, including propionate production from lactate. Finally, we observed two heterogeneous sets of plasma metabolites with opposite association with species positively and negatively associated with hypoxia parameters, respectively. OSA-related hypoxia, but not the number of apneas/hypopneas, is associated with specific gut microbiota species and functions. Our findings lay the foundation for future research on the gut microbiota-mediated health effects of OSA.

Association of Sleep Deprivation and the Risk of Developing Systemic Lupus Erythematosus Among Women.

Sleep deprivation has been associated with risk of autoimmune diseases. Using the Nurses' Health Study (NHS) (1986-2016) and NHSII (1989-2017) cohorts, we aimed in the present study to investigate whether sleep deprivation was associated with risk of developing systemic lupus erythematosus (SLE). Average sleep duration in a 24-hour period was reported in the NHS (1986-2014) and NHSII (1989-2009). Lifestyle, exposure, and medical information was collected on biennial questionnaires. Adjusted Cox regression analyses modeled associations between cumulative average sleep duration (categorical variables) and incident SLE. Interactions between sleep duration and shiftwork, bodily pain (using the Short Form 36 [SF-36] questionnaire), and depression were examined. We included 186,072 women with 187 incident SLE cases during 4,246,094 person-years of follow-up. Chronic low sleep duration (≤5 hours/night versus reference >7-8 hours) was associated with increased SLE risk (adjusted hazard ratio [HRadj ] 2.47 [95% confidence interval (95% CI) 1.29, 4.75]), which persisted after the analysis was lagged (4 years; HRadj 3.14 [95% CI 1.57, 6.29]) and adjusted for shiftwork, bodily pain, and depression (HRadj 2.13 [95% CI 1.11, 4.10]). We detected additive interactions between low sleep duration and high bodily pain (SF-36 score <75) with an attributable proportion (AP) of 64% (95% CI 40%, 87%) and an HR for SLE of 2.97 (95% CI 1.86, 4.75) for those with both risk factors compared to those with neither. Similarly, there was an interaction between low sleep duration and depression, with an AP of 68% (95% CI 49%, 88%) and an HR for SLE of 2.82 (95% CI 1.64, 4.85). Chronic low sleep duration was associated with higher SLE risk, with stronger effects among those with bodily pain and depression, highlighting the potential role of adequate sleep in disease prevention.

Sleep variability over a 2-week period is associated with restfulness and intrinsic limbic network connectivity in adolescents.

Sleep duration and intraindividual variability in sleep duration undergo substantial changes in adolescence and impact brain and behavioral functioning. Although experimental work has linked acute sleep deprivation to heightened limbic responding and reduced regulatory control, there is limited understanding of how variability in sleep patterns might interact with sleep duration to influence adolescent functioning. This is important for optimal balancing of length and consistency of sleep. Here, we investigated how objective indices of sleep duration and variability relate to stress, restfulness, and intrinsic limbic network functioning in adolescents. A sample of 101 adolescents ages 14-18 reported their stressors, after which they wore wrist actigraph watches to monitor their sleep and rated their restfulness every morning over a 2-week period. They also completed a resting-state fMRI scan. Adolescents reporting more stress experienced shorter sleep duration and greater sleep variability over the 2-week period. Longer nightly sleep duration was linked to feeling more rested the next morning, but this effect was reduced in adolescents with high cumulative sleep variability. Sleep variability showed both linear and quadratic effects on limbic connectivity: adolescents with high sleep variability exhibited more connectivity within the limbic network and less connectivity between the limbic and frontoparietal networks than their peers, effects which became stronger once variability exceeded an hour. Results suggest that cumulative sleep variability is related to stress and limbic network connectivity and shows interactive effects with sleep duration, highlighting the importance of balancing length and consistency of sleep for optimal functioning in adolescence.

Associations between cumulative risk, childhood sleep duration, and body mass index across childhood

BackgroundAlthough associations between cumulative risk, sleep, and overweight/obesity have been demonstrated, few studies have examined relationships between these constructs longitudinally across childhood. This study investigated how cumulative risk and sleep duration are related to current and later child overweight/obesity in families across the United States sampled for high sociodemographic risk.MethodsWe conducted secondary analyses on 3690 families with recorded child height and weight within the Fragile Families and Child Well-Being Study. A cumulative risk composite (using nine variables indicating household/environmental, family, and sociodemographic risk) was calculated for each participant from ages 3-9 years. Path analyses were used to investigate associations between cumulative risk, parent-reported child sleep duration, and z-scored child body mass index (BMI) percentile at ages 3 through 9.ResultsHigher cumulative risk experienced at age 5 was associated with shorter sleep duration at year 9, b = − 0.35, p = .01, 95% CI [− 0.57, − 0.11]. At 5 years, longer sleep duration was associated with lower BMI, b = − 0.03, p = .03, 95% CI [− 0.06, − 0.01]. Higher cumulative risk at 9 years, b = − 0.34, p = .02, 95% CI [− 0.57, − 0.10], was concurrently associated with shorter sleep duration. Findings additionally differed by child sex, such that only male children showed an association between sleep duration and BMI.ConclusionsResults partially supported hypothesized associations between child sleep duration, cumulative risk, and BMI emerging across childhood within a large, primarily low socioeconomic status sample. Findings suggest that reducing cumulative risk for families experiencing low income may support longer child sleep duration. Additionally, child sleep duration and BMI are concurrently related in early childhood for male children.

Microglia Are Necessary to Regulate Sleep after an Immune Challenge.

Simple SummaryMicroglia are cells in the brain that mediate inflammation, but little is known about the role of microglia in sleep following an inflammatory challenge. We hypothesized that mice with depleted microglia would sleep less following an injection of a particle that causes inflammation in the body and brain. Brains were collected, the shape and complexity of microglia were measured, and biological data were collected to determine how long the mice slept. Mice fed PLX5622 (PLX), a compound that depletes microglia, had an immediate increase in sleep that resolved by week 2. After the first injection to cause inflammation, mice with depleted microglia slept more than control mice that had normal microglia. The PLX diet was switched to a standard mouse diet and microglia returned to the brain. While microglia were returning, there were no changes in sleep. However, following a second injection to cause inflammation, mice that had new microglia slept the same as control mice during the dark period, but had longer episodes of sleep during the light period. Comparing sleep after the first and second inflammation injection, control mice had different sleep patterns but no change in total time spent sleeping. Mice with new microglia slept less during the dark period. New microglia also had a different shape than microglia in control mice. We conclude that microglia are necessary to regulate sleep after an inflammatory challenge.Microglia play a critical role in the neuroimmune response, but little is known about the role of microglia in sleep following an inflammatory trigger. Nevertheless, decades of research have been predicated on the assumption that an inflammatory trigger increases sleep through microglial activation. We hypothesized that mice (n = 30) with depleted microglia using PLX5622 (PLX) would sleep less following the administration of lipopolysaccharide (LPS) to induce inflammation. Brains were collected and microglial morphology was assessed using quantitative skeletal analyses and physiological parameters were recorded using non-invasive piezoelectric cages. Mice fed PLX diet had a transient increase in sleep that dissipated by week 2. Subsequently, following a first LPS injection (0.4 mg/kg), mice with depleted microglia slept more than mice on the control diet. All mice were returned to normal rodent chow to repopulate microglia in the PLX group (10 days). Nominal differences in sleep existed during the microglia repopulation period. However, following a second LPS injection, mice with repopulated microglia slept similarly to control mice during the dark period but with longer bouts during the light period. Comparing sleep after the first LPS injection to sleep after the second LPS injection, controls exhibited temporal changes in sleep patterns but no change in cumulative minutes slept, whereas cumulative sleep in mice with repopulated microglia decreased during the dark period across all days. Repopulated microglia had a reactive morphology. We conclude that microglia are necessary to regulate sleep after an immune challenge.

Improved Inflammatory and Cardiometabolic Profile After Soft-Tissue Sleep Surgery for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is associated with a rise in serum inflammatory markers, which may be attenuated by sleep surgery. To evaluate whether sleep surgery was associated with improved levels of proinflammatory markers in adults with OSA. Two authors independently searched Cochrane, Embase, and PubMed databases from inception through June 14, 2022. Two authors searched the Cochrane, Embase, and PubMed databases for studies comparing preoperative and postoperative levels of serum biomarkers in patients undergoing sleep surgery. Data were extracted from included articles into a structured proforma. Meta-analyses of the standardized mean difference (SMD) were conducted in random-effects models. To ensure relevance to clinicians and patients, the probability of benefit and number needed to treat were calculated for outcomes that demonstrated a statistically significant effect after sleep surgery. The primary outcome was the preoperative and postoperative levels of serum biomarkers in patients undergoing sleep surgery, including C-reactive protein (CRP), glucose, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and interleukin-6 (IL-6). Data analysis was performed from April to May 2022. Of the 3218 studies screened, 26 studies with 1187 patients (mean [SD] age, 42.8 [11.1] years; 932 [78.5%] men and 255 [21.5%] women) were included. Soft-tissue sleep surgery was associated with a large decrease in CRP (SMD, -0.377; 95% CI, -0.617 to -0.137), total cholesterol (SMD, -0.267; 95% CI, -0.417 to -0.116), LDL (SMD, -0.201; 95% CI, -0.344 to -0.058), IL-6 (SMD, -1.086; 95% CI, -1.952 to -0.221), tumor necrosis factor-α (SMD, -0.822; 95% CI, -1.617 to -0.027), triglyceride (SMD, -0.186; 95% CI, -0.301 to -0.071), and leptin (SMD, -0.519; 95% CI, -0.954 to -0.083) in patients with OSA. Meta-regression highlighted that increased age, higher preoperative score for cumulative sleep time percentage with oxyhemoglobin saturation less than 90% (CT90), and greater change in CT90 postoperatively were associated with a greater decrease in serum CRP levels after soft-tissue sleep surgery. A greater reduction in apnea hypopnea index (AHI) was strongly associated with a greater reduction in total cholesterol and LDL. A greater reduction in body mass index and AHI were also associated with a greater increase in HDL. The findings of this systematic review and meta-analysis of 26 studies suggest that sleep surgery is associated with decreased levels of CRP, total cholesterol, LDL, triglyceride, IL-6, leptin, and TNF-α, which may improve the inflammatory and cardiometabolic profile of patients who undergo sleep surgery.

0417 Odds Ratio Product reveals distinct sleep phenotypes in idiopathic hypersomnia

Abstract Introduction The pathophysiology of idiopathic hypersomnia with long sleep times (IH) remains an enigma. Alternate methods to characterize sleep such as the Odds Ratio Product (ORP), a continuous measure of sleep depth, has the potential to improve understanding of IH. Methods The Odds ratio product is a continuous measure of sleep depth and propensity ranging 0 (very deep sleep) to 2.5 (Least sleep propensity). The difference between 2.5 and ORP in any epoch indicates extent of wake suppression (sleep depth) for that epoch. The cumulative sleep index (CSI) is the integral of sleep suppression across recording time thereby reflecting both the duration and depth of sleep over specified intervals (higher value is deeper and longer sleep). 36 patients with long sleep (600 minutes or longer) recorded through unconstrained polysomnography were analyzed using ORP across the full study (12.7±1.7 hours). Participants were divided into quartiles, 9 patients each(Q1-Q4) based on accumulated sleep across the entire study. Results The mean age for the cohort was 35.8 ± 16.2, of which 29/36 were females. Total sleep time by visual scoring was 679.4 ± 96.4 minutes (range: 601.5 - 1145) minutes). The whole night CSI mean was 989.39 ± 271.64 units (range: 345 to 1427). The quartile values were 618.33 ± 178.83, 919.33 ± 67.27, 1142.89 ± 39.01, and 1277 ± 69.39 units, and not related to total recording or sleep time. The NREM sleep ORP was 1.43± 0.32, 1.06 ± 0.22, 0.73± 0.13 and 0.67 ± 0.19, respectively. This distribution was true for REM sleep ORP also: 1.52 ± 0.30, 1.26 ± 0.19, 1.05 ± 0.25, and 0.84 ± 0.21, respectively. The trait-like ORP-9 (9 seconds post-arousal), and a reflection of sleep fragmentation propensity, was also similarly distributed: 1.60 ± 0.30, 1.29 ± 0.27, 0.92 ± 0.15, and 0.80 ± 0.18, respectively. All comparisons were statistically significant by Tukey multiple comparisons. Conclusion Patients with IH are not homogenous, showing a range of sleep depth in both NREM and REM sleep regardless of total sleep time. These phenotypes of IH could reflect unique endotypic mechanisms, requiring different therapies or have differential treatment responses. Support (If Any)

Daily-level associations between sleep duration and next-day alcohol and cannabis craving and use in young adults

Study objectivesTo examine the effects of sleep duration on next-day alcohol and cannabis craving and use among young adults. MethodA community sample of young adults who reported recent simultaneous alcohol and cannabis use at screening (N = 409; Mage = 21.61; 50.9% female) completed twice daily surveys (morning and afternoon) for five 14-day sampling bursts (i.e., 70 days total). Daily measurements included sleep duration, alcohol and cannabis craving, and alcohol and cannabis use (i.e., number of drinks, hours high). Multilevel models enabled examining associations between sleep duration and substance use/craving at three distinct levels: daily-level, burst-level, and person-level. ResultsAt the day-level, sleep duration was inversely associated with craving for both alcohol and cannabis: Stronger craving was reported on mornings and afternoons after relatively shorter sleep duration. At the burst-level, sleep duration was inversely associated with morning and afternoon alcohol craving indicating stronger alcohol craving, but not cannabis craving, during two-week periods when young adults have accumulated shorter sleep duration. Pertaining to alcohol and cannabis use, no daily-level effects were found, but the burst-level effect showed that participants engaged in greater alcohol use during two-week bursts with shorter sleep duration. ConclusionsBased on a non-clinical sample of young adults reporting substance use, results suggest shorter sleep duration may be a modifiable risk factor as it pertains to substance use and cravings. Results highlight day-level effects of shorter sleep duration on substance use cravings and adverse effects of cumulative sleep deficit on alcohol use.