Immune, inflammatory and cardiovascular consequences of sleep restriction and recovery

Effect of sleep on oral health: A scoping review

Sleep is a vital biological process that facilitates numerous vital functions integral to mental and physical restoration of the body. Sleep deprivation or poor sleep quality not only affects physical health but may also affect oral health. This scoping review aims to collate existing evidence related to the impact of sleep duration and/or quality on oral health. A systematic search strategy using PubMed, Embase, Scopus and CINAHL databases was performed to identify studies that assessed the association between sleep quality or duration and oral health or hygiene. Two researchers independently screened and extracted the data. Eligible studies were critically appraised using the NIH quality assessment tool for observational cohort and cross-sectional studies checklist. The search identified 18,398 studies, from which 14 fulfilled the inclusion criteria. Of the 14 papers, four papers were associated with effect of sleep on caries, 8 papers described the effect of sleep on gingival and periodontal health, and two papers described the effect of sleep on general oral health and oral disease symptoms. This review found a direct link between sleep and dental decay in children, and short sleep duration was associated with an increased risk of periodontitis adults.

Mapping of the network connection between sleep quality symptoms, depression, generalized anxiety, and burnout in the general population of Peru and El Salvador

BACKGROUND

A meta-analysis of randomized controlled trials has suggested a bidirectional relationship between sleep problems and mental health issues. Despite these findings, there is limited conclusive evidence on the relationship between sleep quality, depression, anxiety, and burnout.

OBJECTIVE

The current study aimed to evaluate the relationships between sleep quality symptoms, anxiety, depression, and burnout in samples of adult individuals from two Latin American countries, Peru and El Salvador, through network analysis and to identify key symptoms that reinforce the correlation and intensify the syndromes.

METHODS

A total of 1012 individuals from El Salvador and Peru participated, with an average age of 26.5 years (SD = 9.1). Symptom networks were constructed for both countries based on data from the Jenkins Sleep Scale, Patient Health Questionnaire-2, General Anxiety Disorder-2, and a single burnout item.

RESULTS

The results indicated that Depressed Mood, Difficulty Falling Asleep, and Nervousness were the most central symptoms in a network in the participating countries. The strongest conditional associations were found between symptoms belonging to the same construct, which were similar in both countries. Thus, there is a relationship between Nervousness and Uncontrollable Worry, Anhedonia and Depressed Mood, and Nighttime Awakenings and Difficulty in Staying Asleep. It was observed that burnout is a bridge symptom between both countries and presents stronger conditional associations with Tiredness on Awakening, Depressed Mood, and Uncontrollable Worry. Other bridge symptoms include a Depressed Mood and Nervousness. The network structure did not differ between the participants from Peru and El Salvador.

CONCLUSION

The networks formed by sleep quality, anxiety, depression, and burnout symptoms play a prominent role in the comorbidity of mental health problems among the general populations of Peru and El Salvador. The symptom-based analytical approach highlights the different diagnostic weights of these symptoms. Treatments or interventions should focus on identifying central and bridge symptoms.

Benefits of napping habits in healthy adults: Maintaining alerting performance and cortisol levels change within 90 min of habitual napping time

BACKGROUND

Napping is garnering increased attention as a strategy for adults to sustain alertness and alleviate stress in contemporary society. The nuances of napping habits are emerging as an independent factor influencing the extent of individual benefits. This study aimed to demonstrate the long-term benefits of napping and explore the impact of napping habits on individual alertness, as well as whether this effect was correlated with cortisol levels.

METHODS

The study involved 80 healthy adults categorized into two groups based on self-reported napping habits: habitual nappers (n = 49) and non-habitual nappers (n = 31). Karolinska Sleepiness Scale (KSS), psychomotor vigilance task (PVT), and saliva collection were performed every 30 min within 90 min in the absence of napping during the afternoon dip. The measurements were analyzed using repeated measures ANOVA and Pearson correlation analyses.

RESULTS

There was an interaction between groups and time in reaction speed and lapse number of PVT and cortisol (all p < 0.05). Post hoc analysis found that habitual nappers maintained higher objective alertness and experienced more significant increases in cortisol over time (all p < 0.05). The cortisol levels at sleepiness time were negatively associated with the slowest 10 % reaction speed of PVT in non-habitual nappers (r = -0.409, p = 0.022).

CONCLUSION

Under the premise of mitigating the impacts of acute nap deprivation on sleep homeostasis and rhythm, napping habits emerge as a potential factor influencing the ability of individuals to sustain heightened alertness.

Antioxidant and neurodevelopmental gene polymorphisms in prematurely born individuals influence hypoxia-related oxidative stress

Preterm born (PTB) infants are at risk for injuries related to oxidative stress. We investigated the association between antioxidant and neurodevelopmental gene polymorphisms and oxidative stress parameters in PTB male young adults and their term-born counterparts at rest and during exercise. Healthy young PTB (N = 22) and full-term (N = 15) males underwent graded exercise tests in normobaric normoxic (FiO2 = 0.21) and hypoxic (FiO2 = 0.13) conditions. CAT rs1001179 was associated with decrease in nitrites in the whole group and in PTB individuals (P = 0.017 and P = 0.043, respectively). GPX1 rs1050450 was associated with decrease in ferric reducing antioxidant power in the whole group and in full-term individuals (P = 0.017 and P = 0.021, respectively). HIF1A rs11549465 was associated with decrease in nitrotyrosine and increase in malondialdehyde (P = 0.022 and P = 0.018, respectively). NOTCH4 rs367398 was associated with increase in advanced oxidation protein products and nitrites (P = 0.002 and P = 0.004, respectively) in hypoxia. In normoxia, NOTCH4 rs367398 was associated with increase in malondialdehyde in the whole group (P = 0.043). BDNF rs6265 was associated with decreased nitrites/nitrates in the whole group and in PTB individuals (P = 0.009 and P = 0.043, respectively). Polymorphisms in investigated genes and PTB might influence oxidative stress response after exercise in normoxic or hypoxic conditions far beyond the neonatal period in young male adults.

Ckip-1 3'UTR alleviates prolonged sleep deprivation induced cardiac dysfunction by activating CaMKK2/AMPK/cTNI pathway

Sleep deprivation (SD) has emerged as a critical concern impacting human health, leading to significant damage to the cardiovascular system. However, the underlying mechanisms are still unclear, and the development of targeted drugs is lagging. Here, we used mice to explore the effects of prolonged SD on cardiac structure and function. Echocardiography analysis revealed that cardiac function was significantly decreased in mice after five weeks of SD. Real-time quantitative PCR (RT-q-PCR) and Masson staining analysis showed that cardiac remodeling marker gene Anp (atrial natriuretic peptide) and fibrosis were increased, Elisa assay of serum showed that the levels of creatine kinase (CK), creatine kinase-MB (CK-MB), ANP, brain natriuretic peptide (BNP) and cardiac troponin T (cTn-T) were increased after SD, suggesting that cardiac remodeling and injury occurred. Transcript sequencing analysis indicated that genes involved in the regulation of calcium signaling pathway, dilated cardiomyopathy, and cardiac muscle contraction were changed after SD. Accordingly, Western blotting analysis demonstrated that the cardiac-contraction associated CaMKK2/AMPK/cTNI pathway was inhibited. Since our preliminary research has confirmed the vital role of Casein Kinase-2 -Interacting Protein-1 (CKIP-1, also known as PLEKHO1) in cardiac remodeling regulation. Here, we found the levels of the 3' untranslated region of Ckip-1 (Ckip-1 3'UTR) decreased, while the coding sequence of Ckip-1 (Ckip-1 CDS) remained unchanged after SD. Significantly, adenovirus-mediated overexpression of Ckip-1 3'UTR alleviated SD-induced cardiac dysfunction and remodeling by activating CaMKK2/AMPK/cTNI pathway, which proposed the therapeutic potential of Ckip-1 3'UTR in treating SD-induced heart disease.

The Relationship Between Thyroid Dysfunction and Sleep Quality Among Population of Saudi Arabia

Purpose

Thyroid problems and sleep disturbances are common health problems that impact people of all ages, income levels, and genders. The clinical relationship between these conditions is still not well understood, despite their widespread occurrence. The main objectives of the study were to determine the prevalence of thyroid disorders and evaluate the relationship between them and sleep quality in the Saudi Arabian population.

Patients and Methods

The study employed an observational cross-sectional design and included a representative Saudi Arabian cohort. The Pittsburgh Sleep Quality Index (PSQI) was included in a digital self-administered survey that participants were asked to complete.

Results

There were 1044 responders in the study, most of whom (54%) were between the ages of 21 and 30. Female respondents made up 62% of the sample. Thyroid disorders were diagnosed in 9.2% of cases. A significant correlation was found (p=0.001 and p<0.001, respectively) between thyroid disorders and sleep disturbances as well as the use of sleep medications.

Conclusion

The study revealed a significant prevalence of poor sleep quality in the Saudi population as a whole, with thyroid disorder diagnosis and female gender emerging as independent risk factors. More extensive longitudinal studies in the area are desperately needed.

Resveratrol prevents cognitive deficits induced by sleep deprivation via modulating sirtuin 1 associated pathways in the hippocampus

Accumulating evidence confirms that sleep insufficiency is a high risk factor for cognitive impairment, which involves inflammation and synaptic dysfunction. Resveratrol, an agonist of the Sirt1, has demonstrated anti-inflammation and neuroprotective effects in models of Alzheimer's disease, Parkinson's disease, and schizophrenia. However, the beneficial effects of resveratrol on sleep deprivation-induced cognitive deficits and its underlying molecular mechanisms are unclear. In the present study, thirty-two male C57BL/6 J mice were randomly divided into a Control+DMSO group, Control+Resveratrol group, SD+DMSO group, and SD+Resveratrol group. The mice in the SD+Resveratrol group underwent 5 days of sleep deprivation after pretreatment with resveratrol (50 mg/kg) for 2 weeks, while the mice in the SD+DMSO group only underwent sleep deprivation. After sleep deprivation, we evaluated spatial learning and memory function using the Morris water maze test. We used general molecular biology techniques to detect changes in levels of pro-inflammatory cytokines and Sirt1/miR-134 pathway-related synaptic plasticity proteins. We found that resveratrol significantly reversed sleep deprivation-induced learning and memory impairment, elevated interleukin-1β, interleukin-6, and tumor necrosis factor-α levels, and decreased brain-derived neurotrophic factor, tyrosine kinase receptor B, postsynaptic density protein-95, and synaptophysin levels by activating the Sirt1/miR-134 pathway. In conclusion, resveratrol is a promising agent for preventing sleep deprivation-induced cognitive dysfunction by reducing pro-inflammatory cytokines and improving synaptic function via the Sirt1/miR-134 pathway.

Association between weekend catch-up sleep and the risk of prediabetes and diabetes: A cross-sectional study using KNHANES

BACKGROUND

The objectives of this cross-sectional study were to explore the relationship between weekend catch-up sleep (WCUS) and the risk of prediabetes/diabetes and to assess how this risk varies based on WCUS duration, using a large population sample in South Korea.

METHODS

Data were sourced from the 2021 Korea National Health and Nutrition Examination Survey, involving 2472 subjects aged 30 years and above, employed, and not using blood glucose-lowering medications. Prediabetes/diabetes risk was examined based on the presence of WCUS. Participants were categorized into four groups by WCUS duration (< 1, ≥ 1 and < 2, ≥ 2 and < 3, and ≥ 3 h) to evaluate the prediabetes/diabetes risk across varying WCUS durations.

RESULTS

No significant difference in prediabetes/diabetes risk was observed between the WCUS and non-WCUS groups. In subgroup analysis, a WCUS duration of 1 to 2 h was related to a lower odds ratio of prediabetes (aOR = 0.618, 95% CI = 0.382-0.999), while 3 h or more was associated with a higher odds ratio of diabetes (aOR = 3.098, 95% CI = 1.561-6.149).

CONCLUSIONS

In individuals who experience insufficient sleep during weekdays and manage to achieve the optimal average sleep duration of 1 to 2 h of WCUS, WCUS was associated with improved blood glucose regulation. However, compensating for excessive weekday sleep deprivation with WCUS of 3 h or more was associated with impaired blood glucose regulation.

Longitudinal association of sleep duration with possible sarcopenia: evidence from CHARLS

OBJECTIVES

There are limited data on the relationship between sleep duration and possible sarcopenia. Hence, this study aimed to investigate the associations of sleep duration with possible sarcopenia and its defining components based on the China Health and Retirement Longitudinal Study (CHARLS).

DESIGN

A retrospective cohort study.

SETTING

This study was conducted on participants aged over 45 years applying the 2011 baseline and 2015 follow-up survey from CHARLS covering 450 villages, 150 counties and 28 provinces.

PARTICIPANTS

Data from 5036 individuals (2568 men and 2468 women) free of possible sarcopenia at baseline were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

The dose-response relationship between sleep duration and possible sarcopenia.

RESULTS

During 4 years of follow-up, 964 (19.14%) participants developed possible sarcopenia. Compared with participants who slept 6-8 hours per night, those with shorter sleep duration (<6 hours per night) were independently associated with 22% (OR, 1.22; 95% CI, 1.04 to 1.44) increased risk of developing possible sarcopenia and 27% (OR, 1.27; 95% CI, 1.04 to 1.57) increased risk of developing low handgrip strength after controlling for potential confounders. Long sleep duration (>8 hours per night) was not significantly associated with incident possible sarcopenia. The plots of restricted cubic splines exhibited an atypical inverse J-shaped association between sleep duration and possible sarcopenia. Subgroup analysis showed a stronger association between sleep duration and possible sarcopenia in participants aged 45-59 years and composed of male populations.

CONCLUSIONS

Short sleep duration was a potential risk factor for possible sarcopenia and low handgrip strength. The improvement of sleep duration should be considered a target in early preventive and administrative strategies against the development of handgrip strength decline and further reduced the occurrence of sarcopenia.

The pathogenesis of OSA-related hypertension: what are the determining factors?

Sleep-disordered breathing has a relatively high prevalence, which varies from 3-7% in males and from 2-5% in females in the adult population. Studies published in the literature have shown that sleep apnea is closely related to an increased risk of developing various pathologies, among which arterial hypertension stands out. The prevalence of hypertension in patients suffering from obstructive sleep apnea (OSA) ranges from 35-80% and appears to be related to OSA severity. Approximately 40-50% of patients affected by hypertension are also affected by OSA and this association seems to be stronger in young and middle-aged adults (<50 years of age). The primary objective of this narrative review is to provide an update on what are the main contributing comorbidities to the development of a hypertensive state in patients suffering from OSA, an independent risk factor for diurnal hypertension, implicated as a risk factor for the first stroke, recurrent stroke, and post-stroke mortality. There are a lot of factors that contribute to developing a hypertensive state in OSA patients, some more decisive, others less. More evidence from longitudinal studies is needed on the impact of OSA on cardiovascular risk in females, on the causal link between OSA and arterial hypertension or metabolic diseases, like diabetes and glucose intolerance, and the effect of different kinds of OSA treatment.

Collagen peptide supplementation before bedtime reduces sleep fragmentation and improves cognitive function in physically active males with sleep complaints

PURPOSE

The primary aim of this study was to examine whether a glycine-rich collagen peptides (CP) supplement could enhance sleep quality in physically active men with self-reported sleep complaints.

METHODS

In a randomized, crossover design, 13 athletic males (age: 24 ± 4 years; training volume; 7 ± 3 h·wk1) with sleep complaints (Athens Insomnia Scale, 9 ± 2) consumed CP (15 g·day1) or a placebo control (CON) 1 h before bedtime for 7 nights. Sleep quality was measured with subjective sleep diaries and actigraphy for 7 nights; polysomnographic sleep and core temperature were recorded on night 7. Cognition, inflammation, and endocrine function were measured on night 7 and the following morning. Subjective sleepiness and fatigue were measured on all 7 nights. The intervention trials were separated by ≥ 7 days and preceded by a 7-night familiarisation trial.

RESULTS

Polysomnography showed less awakenings with CP than CON (21.3 ± 9.7 vs. 29.3 ± 13.8 counts, respectively; P = 0.028). The 7-day average for subjective awakenings were less with CP vs. CON (1.3 ± 1.5 vs. 1.9 ± 0.6 counts, respectively; P = 0.023). The proportion of correct responses on the baseline Stroop cognitive test were higher with CP than CON (1.00 ± 0.00 vs. 0.97 ± 0.05 AU, respectively; P = 0.009) the morning after night 7. There were no trial differences in core temperature, endocrine function, inflammation, subjective sleepiness, fatigue and sleep quality, or other measures of cognitive function or sleep (P > 0.05).

CONCLUSION

CP supplementation did not influence sleep quantity, latency, or efficiency, but reduced awakenings and improved cognitive function in physically active males with sleep complaints.

Sleep and cardiometabolic risk. Narrative revision

OBJECTIVES

Sleep disturbances, including disrupted sleep and short sleep duration, are highly prevalent and are prospectively associated with an increased risk for various chronic diseases, including cardiometabolic, neurodegenerative, and autoimmune diseases.

MATERIAL AND METHODS

This is a narrative review of the literature based on numerous articles published in peer-reviewed journals since the beginning of this century.

RESULTS

The relationship between sleep disorders and metabolic dysregulation has been clearly established, mainly in the setting of modern epidemic of cardiometabolic disease, a cluster of conditions include obesity, insulin resistance, arterial hypertension, and dyslipidaemia, all of them considered as main risk factor for atherosclerotic cardiovascular disease (ACVD) and its clinical expression such as ischemic ictus, myocardial infarction and type 2 diabetes. Clinically viable tools to measure sleep duration and quality are needed for routine screening and intervention.

CONCLUSIONS

In view of what has been exposed in this review, it is evident that the timing, amount, and quality of sleep are critical to reduce the burden of risk factors for several chronic disease, including ACVD and type 2 diabetes, and most relevant in young people. Future research studies should elucidate the effectiveness of multimodal interventions to counteract the risk of short sleep for optimal patient outcomes across the healthcare continuum, especially in young people.

Application of Braided Piezoelectric Poly-l-Lactic Acid Cord Sensor to Sleep Bruxism Detection System with Less Physical or Mental Stress

For many years, we have been developing flexible sensors made of braided piezoelectric poly-l-lactic acid (PLLA) fibers that can be tied and untied for practical applications in society. To ensure good quality of sleep, the occurrence of bruxism has been attracting attention in recent years. Currently, there is a need for a system that can easily and accurately measure the frequency of bruxism at home. Therefore, taking advantage of the braided piezoelectric PLLA cord sensor's unique characteristic of being sewable, we aimed to provide a system that can measure the frequency of bruxism using the braided piezoelectric PLLA cord sensor simply sewn onto a bed sheet on which the subject lies down. After many tests using trial and error, the sheet sensor was completed with zigzag stitching. Twenty subjects slept overnight in a hospital room on sheets integrated with a braided piezoelectric PLLA cord. Polysomnography (PSG) was simultaneously performed on these subjects. The results showed that their bruxism could be detected with an accuracy of more than 95% compared with PSG measurements, which can only be performed in a hospital by a physician and are more burdensome for the subjects, with the subjects simply lying on the bed sheet with a braided piezoelectric PLLA cord sensor sewn into it.

Temporal dynamics of pro-inflammatory cytokines and serum corticosterone following acute sleep fragmentation in male mice

Obstructive sleep apnea is increasing worldwide, leading to disordered sleep patterns and inflammatory responses in brain and peripheral tissues that predispose individuals to chronic disease. Pro-inflammatory cytokines activate the inflammatory response and are normally regulated by glucocorticoids secreted from adrenal glands. However, the temporal dynamics of inflammatory responses and hypothalamic-pituitary-adrenal (HPA) axis activation in relation to acute sleep fragmentation (ASF) are undescribed. Male C57BL/6J mice were exposed to ASF or control conditions (no ASF) over specified intervals (1, 2, 6, or 24 h) and cytokine gene expression (IL-1β, TNF-α) in brain and peripheral tissues as well as serum glucocorticoid and interleukin-6 (IL-6) concentration were assessed. The HPA axis was rapidly activated, leading to elevated serum corticosterone from 1-24 h of ASF compared with controls. This activation was followed by elevated serum IL-6 concentration from 6-24 h of ASF. The tissue to first exhibit increased pro-inflammatory gene expression from ASF was heart (1 h of ASF). In contrast, pro-inflammatory gene expression was suppressed in hypothalamus from 1 h of ASF, but elevated at 6 h. Because the HPA axis was activated throughout ASF, this suggests that brain, but not peripheral, pro-inflammatory responses were rapidly inhibited by glucocorticoid immunosuppression.

Lower handgrip strength in short-sleeper individuals with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is a frequently observed and remarkably incapacitating disorder worldwide. As a multisystem disorder, OSA has been linked to a plethora of clinical parameters though physical parameters like muscle strength have been scantily studied. Hand grip strength (HGS) is a practical marker of physical function that has been associated with mortality and an array of clinical outcomes as well as physiological parameters like sleep duration. A few seminal studies have observed no link between HGS and OSA severity while no studies evaluated the relationship between objectively determined sleep duration and HGS in OSA.

OBJECTIVE

The present study aimed to evaluate the HGS indices among both OSA severity groups and objectively determined sleep duration groups in OSA.

METHODS

111 treatment-naïve mostly middle-aged individuals with OSA (86 males) were recruited in a tertiary sleep center. Three OSA severity groups were determined by the Apnea-Hypopnea Index while three sleep duration groups were objectively determined by Total Sleep Time (TST). Dominant and non-dominant maximum and average HGS were calculated using a digital hand dynamometer.

RESULTS

Short-sleeper individuals with OSA were found to have lower HGS indices than intermediate or sufficient sleepers with OSA while no differences in HGS indices among OSA severity groups were observed. All HGS indices correlated with TST.

CONCLUSIONS

Future insights can be gleaned from the present results regarding the conceivably transdiagnostic relationship between sleep duration and HGS as well as the potential use of HGS as a marker in OSA.

Evaluation of weekend catch-up sleep and weekday sleep duration in relation to metabolic syndrome in Korean adults

PURPOSE

This study aimed to evaluate whether or not the relationship between weekday sleep duration and prevalence of metabolic syndrome (MetS) differs according to weekend catch-up sleep (CUS) in Korean adults.

METHODS

Data from the Korea National Health and Nutrition Examination Survey 2016-2020, including that regarding weekday sleep duration, weekend CUS, MetS components, and confounding factors such as sociodemographic factors, health behaviors, and illness-related factors, were evaluated in Korean adults aged 19 to 80 years. Complex-sample logistic regression was applied after adjusting for confounding factors.

RESULTS

Among 24,313 adults, the prevalence of MetS was lowest in individuals with 6-7 h of sleep on weekdays and CUS ≥ 2 h (17.7%, reference group). The interaction between weekday sleep duration and weekend CUS for MetS was significant. Compared to the reference group, the prevalence of MetS was higher in those who slept < 7 h and had a maximum CUS of 1 h (aORs, 1.42-1.66), and in those who slept ≥ 9 h and had a maximum CUS of 2 h (aORs, 1.28-1.82). In subjects with no CUS or CUS ≥ 2 h, the prevalence of MetS was greater even in those with adequate weekday sleep duration (7- 9 h) than in the reference group (aORs, 1.37 and 1.64, respectively).

CONCLUSION

Weekend CUS may help individuals with short weekday sleep duration reduce their odds of developing MetS, but it may worsen the condition in individuals with a long weekday sleep length.

The 24-h activity cycle and cardiovascular outcomes: establishing biological plausibility using arterial stiffness as an intermediate outcome

This review proposes a biologically plausible working model for the relationship between the 24-h activity cycle (24-HAC) and cardiovascular disease. The 24-HAC encompasses moderate-to-vigorous physical activity (MVPA), light physical activity, sedentary behavior (SB), and sleep. MVPA confers the greatest relative cardioprotective effect, when considering MVPA represents just 2% of the day if physical activity guidelines (30 min/day) are met. While we have well-established guidelines for MVPA, those for the remaining activity behaviors are vague. The vague guidelines are attributable to our limited mechanistic understanding of the independent and additive effects of these behaviors on the cardiovascular system. Our proposed biological model places arterial stiffness, a measure of vascular aging, as the key intermediate outcome. Starting with prolonged exposure to SB or static standing, we propose that the reported transient increases in arterial stiffness are driven by a cascade of negative hemodynamic effects following venous pooling. The subsequent autonomic, metabolic, and hormonal changes further impair vascular function. Vascular dysfunction can be offset by using mechanistic-informed interruption strategies and by engaging in protective behaviors throughout the day. Physical activity, especially MVPA, can confer protection by chronically improving endothelial function and associated protective mechanisms. Conversely, poor sleep, especially in duration and quality, negatively affects hormonal, metabolic, autonomic, and hemodynamic variables that can confound the physiological responses to next-day activity behaviors. Our hope is that the proposed biologically plausible working model will assist in furthering our understanding of the effects of these complex, interrelated activity behaviors on the cardiovascular system.

Association between Sleep Quality and Cardiac Autonomic Modulation in Adolescents: A Cross Sectional Study

Objective  To analyze the impact of sleep quality/duration on cardiac autonomic modulation on physically active adolescents with obesity. Materials and Methods  The present cross-sectional study included 1,150 boys with a mean age of 16.6 ± 1.2 years. The assessment of cardiac functions included the frequency domain of heart rate variability (HRV; low frequency - LF; high frequency - HF; and the ratio between these bands -LF/HF -, defined as the sympathovagal balance), and each parameter was categorized as low / high . Physical activity levels and sleep quality/duration were obtained by questionnaires. Abdominal obesity was assessed and defined as waist circumference > 80 th percentile. Results  Poor sleep quality resulted in lower HF (odds ratio [OR]: 1.8; 95% confidence interval [95%CI]: 1.01-3.21]) regardless of physical activity and abdominal obesity. Moreover, the study found no association between sleep duration and HRV parameters in adolescents. Conclusion  Sleep quality, not sleep duration, reduces parasympathetic cardiac modulation apart from other factors such as physical activity and abdominal obesity in adolescents.

Unraveling the associations and causalities between glucose metabolism and multiple sleep traits

Purpose

The aim of our study is to estimate the associations and causalities of glucose metabolism traits of fasting blood glucose (FBG), fasting insulin (FINS), glycosylated hemoglobin (HbA1c), and 2-h glucose post-challenge (2hGlu) with sleep traits consisting of excessive daytime sleepiness (EDS), insomnia, and sleep duration.

Methods

We employed standard quantitative analysis procedures to assess the associations between sleep traits and glucose metabolism. Moreover, we acquired published genome-wide association studies (GWAS) summary statistics for these traits and conducted Mendelian randomization (MR) analyses to estimate their causal directions and effects. Inverse variance weighting (IVW) was employed as the primary approach, followed by sensitivity analyses.

Results

A total of 116 studies with over 840,000 participants were included in the quantitative analysis. Our results revealed that participants with abnormal glucose metabolism had higher risks for EDS (OR [95% CI] = 1.37 [1.10,1.69]), insomnia (OR [95% CI] = 1.65 [1.24,2.20]), and both short and long sleep duration (OR [95% CI] = 1.35 [1.12,1.63]; OR [95% CI] = 1.38 [1.13,1.67] respectively). In addition, individuals with these sleep traits exhibited alterations in several glycemic traits compared with non-affected controls. In MR analysis, the primary analysis demonstrated causal effects of 2hGlu on risks of EDS (OR [95% CI] = 1.022 [1.002,1.042]) and insomnia (OR [95% CI] = 1.020[1.001,1.039]). Furthermore, FINS was associated with short sleep duration (OR [95% CI] = 1.043 [1.018,1.068]), which reversely presented a causal influence on HbA1c (β [95% CI] = 0.131 [0.022,0.239]). These results were confirmed by sensitivity analysis.

Conclusion

Our results suggested mutual risk and causal associations between the sleep traits and glycemic traits, shedding new light on clinical strategies for preventing sleep disorders and regulating glucose metabolism. Future studies targeting these associations may hold a promising prospect for public health.

Sleep Architecture Patterns in Critically Ill Patients and Survivors of Critical Illness: A Retrospective Study

Rationale: Sleep abnormalities are very frequent in critically ill patients during and after intensive care unit (ICU) stays. Their mechanisms are poorly understood. The odds ratio product (ORP) is a continuous metric (range, 0.0-2.5) of sleep depth measured in 3-second intervals and derived from the relationship of powers of different electroencephalographic frequencies to one another. When expressed as the percentage of epochs within 10 ORP deciles covering the entire ORP range, it provides information about the mechanism(s) of abnormal sleep. Objectives: To determine ORP architecture types in critically ill patients and survivors of critical illness who had previously undergone sleep studies. Methods: Nocturnal polysomnograms from 47 unsedated critically ill patients and 23 survivors of critical illness at hospital discharge were analyzed. Twelve critically ill patients were monitored also during the day, and 15 survivors underwent subsequent polysomnography 6 months after hospital discharge. In all polysomnograms, each 30-second epoch was characterized by the mean ORP of the 10 3-second epochs. The number of 30-second epochs with mean ORP within each of 10 ORP deciles covering the entire ORP range (0.0-2.5) was calculated and expressed as a percentage of total recording time. Thereafter, each polysomnogram was characterized using a two-digit ORP type, with the first digit (range, 1-3) reflecting increasing degrees of deep sleep (ORP < 0.5, deciles 1 and 2) and the second digit (range, 1-3) reflecting increasing degrees of full wakefulness (ORP > 2.25, decile 10). Results from patients were compared with those from 831 age- and gender-matched community dwellers free of sleep disorders. Results: In critically ill patients, types 1,1 and 1,2 (little deep sleep and little or average full wakefulness) dominated (46% of patients). In the community, these types are uncommon (<15%) and seen primarily in disorders that preclude progression to deep sleep (e.g., very severe obstructive sleep apnea). Next in frequency (22%) was type 1,3, consistent with hyperarousal. Day ORP sleep architecture was similar to night results. Survivors had similar patterns, with little improvement after 6 months. Conclusions: Sleep abnormalities in critically ill patients and survivors of critical illness result primarily from stimuli that preclude progression to deep sleep or from the presence of a hyperarousal state.

Relationship of Chronic Systemic Inflammation to Both Chronic Lifestyle-Related Diseases and Osteoarthritis: The Case for Lifestyle Medicine for Osteoarthritis

Systemic inflammation is a root cause of lifestyle-related chronic diseases and may also play a role in the development and progression of osteoarthritis (OA). Lifestyle medicine seeks to treat, prevent, and reverse lifestyle-related chronic disease via 6 pillars: nutrition, sleep health, stress management, physical activity, social connections, and risky behavior avoidance/reduction. This article presents a review of the literature in which we assess the connections between the 6 pillars of lifestyle medicine, chronic systemic inflammation, and OA. We also discuss the whole-person approach that lifestyle medicine interventions can provide to reduce chronic systemic inflammation and affect the development or progression of OA.

Paradoxical Effects of Prolonged Insufficient Sleep on Lipid Profile: A Pooled Analysis of 2 Randomized Trials

Background Insufficient sleep is associated with increased cardiovascular disease risk, but causality is unclear. We investigated the impact of prolonged mild sleep restriction (SR) on lipid and inflammatory profiles. Methods and Results Seventy-eight participants (56 women [12 postmenopausal]; age, 34.3±12.5 years; body mass index, 25.8±3.5 kg/m2) with habitual sleep duration 7 to 9 h/night (adequate sleep [AS]) underwent two 6-week conditions in a randomized crossover design: AS versus SR (AS-1.5 h/night). Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglycerides, and inflammatory markers (CRP [C-reactive protein], interleukin 6, and tumor necrosis factor-α) were assessed. Linear models tested effects of SR on outcomes in the full sample and by sex+menopausal status (premenopausal versus postmenopausal women+men). In the full sample, SR increased high-density lipoprotein cholesterol compared with AS (β=1.2±0.5 mg/dL; P=0.03). Sex+menopausal status influenced the effects of SR on change in total cholesterol (P-interaction=0.04), LDL-C (P-interaction=0.03), and interleukin 6 (P-interaction=0.07). Total cholesterol and LDL-C decreased in SR versus AS in premenopausal women (total cholesterol: β=-4.2±1.9 mg/dL; P=0.03; LDL-C: β=-6.3±2.0 mg/dL; P=0.002). Given paradoxical effects of SR on cholesterol concentrations, we explored associations between changes in inflammation and end point lipids under each condition. Increases in interleukin 6 and tumor necrosis factor-α during SR tended to relate to lower LDL-C in premenopausal women (interleukin 6: β=-5.3±2.6 mg/dL; P=0.051; tumor necrosis factor-α: β=-32.8±14.2 mg/dL; P=0.027). Conclusions Among healthy adults, prolonged insufficient sleep does not increase atherogenic lipids. However, increased inflammation in SR tends to predict lower LDL-C in premenopausal women, resembling the "lipid paradox" in which low cholesterol associates with increased cardiovascular disease risk in proinflammatory conditions. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02835261, NCT02960776.

Reducing complement activation during sleep deprivation yields cognitive improvement by dexmedetomidine

BACKGROUND

Sleep loss and its associated conditions (e.g. cognitive deficits) represent a large societal burden, but the underlying mechanisms of these cognitive deficits remain unknown. This study assessed the effect of dexmedetomidine (DEX) on cognitive decline induced by sleep loss.

METHODS

C57BL/6 mice were subjected to chronic sleep restriction (CSR) for 20 h (5 pm-1 pm the next day) daily for 7 days, and cognitive tests were subsequently carried out. The neuromolecular and cellular changes that occurred in the presence and absence of DEX (100 μg kg-1, i.v., at 1 pm and 3 pm every day) were also investigated.

RESULTS

CSR mice displayed a decline in learning and memory by 12% (P<0.05) in the Y-maze and by 18% (P<0.01) in the novel object recognition test; these changes were associated with increases in microglial activation, CD68+ microglial phagosome counts, astrocyte-derived complement C3 secretion, and microglial C3a receptor expression (all P<0.05). Synapse elimination, as indicated by a 66% decrease in synaptophysin expression (P=0.0004) and a 45% decrease in postsynaptic density protein-95 expression (P=0.0003), was associated with the occurrence of cognitive deficits. DEX activated astrocytic α2A adrenoceptors and inhibited astrocytic complement C3 release to attenuate synapse elimination through microglial phagocytosis. DEX restored synaptic connections and reversed cognitive deficits induced by CSR.

CONCLUSIONS

The results demonstrate that complement pathway activation associated with synapse elimination contributes to sleep loss-related cognitive deficits and that dexmedetomidine protects against sleep deprivation-induced complement activation. Dexmedetomidine holds potential for preventing cognitive deficits associated with sleep loss, which warrants further study.

Hormone physiology and sleep dynamics among BaYaka foragers of the Congo Basin: Gendered associations between nighttime activity, testosterone, and cortisol

Sleep quality is an important contributor to health disparities and affects the physiological function of the immune and endocrine systems, shaping how resources are allocated to life history demands. Past work in industrial and post-industrial societies has shown that lower total sleep time (TST) or more disrupted nighttime sleep are linked to flatter diurnal slopes for cortisol and lower testosterone production. There has been little focus on these physiological links in other socio-ecological settings where routine sleep conditions and nighttime activity demands differ. We collected salivary hormone (testosterone, cortisol) and actigraphy-based sleep data from Congolese BaYaka foragers (N = 39), who have relatively short and fragmented nighttime sleep, on average, in part due to their typical social sleep conditions and nighttime activity. The hormone and sleep data collections were separated by an average of 11.23 days (testosterone) and 2.84 days (cortisol). We found gendered links between nighttime activity and adults' hormone profiles. Contrary to past findings in Euro-American contexts, BaYaka men who were more active at night, on average, had higher evening testosterone than those with lower nighttime activity, with a relatively flat slope relating nighttime activity and evening testosterone in women. Women had steeper diurnal cortisol curves with less disrupted sleep. Men had steeper cortisol diurnal curves if they were more active at night. BaYaka men often hunt and socialize when active at night, which may help explain these patterns. Overall, our findings indicate that the nature of nighttime activities, including their possible social and subsistence contexts, are potentially important modifiers of sleep quality-physiology links, meriting further research across contexts.

Association between serum neurofilament light chain levels and sleep disorders in patients with Parkinson's disease

OBJECTIVES

This study aimed to investigate the levels of serum neurofilament light chain (NFL) and glial fibrillary acidic protein (GFAP) in patients with Parkinson's disease (PD) and PD patients with sleep disorders (PD-SD), as well as the relationship between these proteins and sleep disorders in PD patients.

METHODS

A total of 96 PD patients and 38 healthy controls (HC) were included in this study, of which 70 PD patients experienced sleep disorders. Both motor symptoms and sleep conditions were assessed in all PD patients. The ultrasensitive single molecule array (SIMOA) technique was used to quantify NFL and GFAP in the serum. All data were statistically analyzed using SPSS 23.0.

RESULTS

Serum NFL and GFAP levels were significantly higher in PD patients than in HC. Similarly, PD-SD patients exhibited higher levels of these two proteins than PD patients without sleep disorders (PD-NSD). In addition, both serum GFAP and NFL were significantly associated with sleep-related scales in PD patients. After covariate-adjusted binary logistic regression analysis, NFL remained statistically significant in PD patients with or without sleep disorders, unlike GFAP.

CONCLUSIONS

Our findings substantiate that serum NFL and GFAP levels are elevated in PD and PD-SD, suggesting neurological axon damage in PD patients, which may be more severe in PD-SD than in PD-NSD. These findings may affect disease diagnosis and provide the foothold for future studies on the underlying mechanisms.

Non-Conventional Risk Factors: "Fact" or "Fake" in Cardiovascular Disease Prevention?

Cardiovascular diseases (CVDs), such as arterial hypertension, myocardial infarction, stroke, heart failure, atrial fibrillation, etc., still represent the main cause of morbidity and mortality worldwide. They significantly modify the patients' quality of life with a tremendous economic impact. It is well established that cardiovascular risk factors increase the probability of fatal and non-fatal cardiac events. These risk factors are classified into modifiable (smoking, arterial hypertension, hypercholesterolemia, low HDL cholesterol, diabetes, excessive alcohol consumption, high-fat and high-calorie diet, reduced physical activity) and non-modifiable (sex, age, family history, of previous cardiovascular disease). Hence, CVD prevention is based on early identification and management of modifiable risk factors whose impact on the CV outcome is now performed by the use of CV risk assessment models, such as the Framingham Risk Score, Pooled Cohort Equations, or the SCORE2. However, in recent years, emerging, non-traditional factors (metabolic and non-metabolic) seem to significantly affect this assessment. In this article, we aim at defining these emerging factors and describe the potential mechanisms by which they might contribute to the development of CVD.

Fructus gardeniae ameliorates anxiety-like behaviors induced by sleep deprivation via regulating hippocampal metabolomics and gut microbiota

Fructus gardeniae (FG) is a traditional Chinese medicine and health food for thousands of years of application throughout Chinese history and is still widely used in clinical Chinese medicine. FG has a beneficial impact on anxiety, depression, insomnia, and psychiatric disorders; however, its mechanism of action requires further investigation. This study aimed to investigate the effects and mechanisms of FG on sleep deprivation (SD)-induced anxiety-like behavior in rats. A model of SD-induced anxiety-like behavior in rats was established by intraperitoneal injection of p-chlorophenylalanine (PCPA). This was accompanied by neuroinflammation and metabolic abnormalities in the hippocampus and disturbance of intestinal microbiota. However reduced SD-induced anxiety-like behavior and decreased levels of pro-inflammatory cytokines including TNF-α and IL-1β were observed in the hippocampus of rats after 7 days of FG intervention. In addition, metabolomic analysis demonstrated that FG was able to modulate levels of phosphatidylserine 18, Phosphatidylinositol 18, sn-glycero-3-phosphocholine, deoxyguanylic acid, xylose, betaine and other metabolites in the hippocampus. The main metabolic pathways of hippocampal metabolites after FG intervention involve carbon metabolism, glycolysis/gluconeogenesis, pentose phosphate, and glycerophospholipid metabolism. 16S rRNA sequencing illustrated that FG ameliorated the dysbiosis of gut microbiota in anxious rats, mainly increased the abundance of Muribaculaceae and Lactobacillus, and decreased the abundance of Lachnospiraceae_NK4A136_group. In addition, the correlation analysis demonstrated that there was a close relationship between hippocampal metabolites and intestinal microbiota. In conclusion, FG improved the anxiety behavior and inhibited of neuroinflammation in sleep-deprived rats, and the mechanism may be related to the FG regulation of hippocampal metabolites and intestinal microflora composition.

Multiomics analysis of human peripheral blood reveals marked molecular profiling changes caused by one night of sleep deprivation

Sleep insufficiency is associated with various disorders; the molecular basis is unknown until now. Here, 14 males and 18 females were subjected to short-term (24 h) sleep deprivation, and donated fasting blood samples prior to (day 1) and following (days 2 and 3) short-term sleep deprivation. We used multiple omics techniques to examine changes in volunteers' blood samples that were subjected to integrated, biochemical, transcriptomic, proteomic, and metabolomic analyses. Sleep deprivation caused marked molecular changes (46.4% transcript genes, 59.3% proteins, and 55.6% metabolites) that incompletely reversed by day 3. The immune system in particular neutrophil-mediated processes associated with plasma superoxidase dismutase-1 and S100A8 gene expression was markedly affected. Sleep deprivation decreased melatonin levels and increased immune cells, inflammatory factors and c-reactive protein. By disease enrichment analysis, sleep deprivation induced signaling pathways for schizophrenia and neurodegenerative diseases enriched. In sum, this is the first multiomics approach to show that sleep deprivation causes prominent immune changes in humans, and clearly identified potential immune biomarkers associated with sleep deprivation. This study indicated that the blood profile following sleep disruption, such as may occur among shift workers, may induce immune and central nervous system dysfunction.

Association of longitudinal patterns of nighttime sleep duration and daytime napping duration with risk of multimorbidity

OBJECTIVES

To determine whether longitudinal trajectories of nighttime sleep duration and daytime napping duration are related to subsequent multimorbidity risk. To explore whether daytime napping can compensate for negative effects of short nighttime sleep.

METHODS

The current study included 5262 participants from China Health and Retirement Longitudinal Study. Self-reported nighttime sleep duration and daytime napping duration were collected from 2011 to 2015. The 4-year sleep duration trajectories were conducted by group-based trajectory modeling. The 14 medical conditions were defined by self-reported physician diagnoses. Multimorbidity was diagnosed as participants with 2 or more of the 14 chronic diseases after 2015. Associations between sleep trajectories and multimorbidity were assessed by Cox regression models.

RESULTS

During 6.69 years of follow-up, we observed multimorbidity in 785 participants. Three nighttime sleep duration trajectories and three daytime napping duration trajectories were identified. Participants with persistent short nighttime sleep duration trajectory had the higher risk of multimorbidity (hazard ratio = 1.37, 95% confidence interval: 1.06-1.77), compared with those with persistent recommended nighttime sleep duration trajectory. Participants with persistent short nighttime sleep duration and persistent seldom daytime napping duration had the highest risk of multimorbidity (hazard ratio = 1.69, 95% confidence interval: 1.16-2.46).

CONCLUSIONS

In this study, persistent short nighttime sleep duration trajectory was associated with subsequent multimorbidity risk. Daytime napping could compensate for the risk of insufficient night sleep.

Assessment of the Risk and Symptoms of SARS-CoV-2 Infection Among Healthcare Workers During the Omicron Transmission Period: A Multicentric Study from Four Hospitals of Mainland China

Purpose

The SARS-CoV-2 omicron variant emerged and spread rapidly among the population in the early stage of China's normalized prevention and control in December 2022. Healthcare workers (HCWs) are particularly exposed to SARS-CoV-2, it is important to evaluate the impact of the omicron pandemic on HCWs in China.

Methods

A self-administered online survey was conducted on infected HCWs from four hospitals of Taizhou. A total of 748 HCWs received the survey via DingTalk, and 328 responded to the questionnaire. The risk factors were investigated using univariate and multivariate logistic regression analysis.

Results

By December 20, 2022, 748 HCWs tested positive by PCR, and the infection rate was 11.4% (748/6581). Among 328 respondents, the most common symptoms were cough (88.4%), fever (83.5%), runny nose (77.1%), sore throat (73.2%), headache (70.1%), muscle aches (67.1%), and fatigue (53.4%). 69.8% (229/328) of the participants had five or more major onset symptoms, while no severe case was observed. The multivariate analysis indicated that the poor sleep quality (OR = 2.29, 95% CI: 1.31-4.02, P = 0.004) was an independent risk factor for more major onset symptoms, while wore gloves ≥95% times in working (OR = 0.49, 95% CI: 0.28-0.85, P = 0.011) was significantly related to fewer symptoms. In addition, 239 (72.9%) recipients reported high fever (temperature ≥38.5°C), less common cold (≤3 vs >3 times/year, OR = 2.20, 95% CI: 1.05-4.65, P = 0.038) was significantly associated with high fever.

Conclusion

Our findings imply rapid transmissibility of omicron and multiple-onset symptoms among HCWs. Improved autoimmunity and self-protection measures for HCWs may be helpful in controlling infection and clinical symptoms. Our results provide empirical reference values for improved countermeasures and protective measures for major public health emergencies.

Association between Sleep Duration and Incident Diabetes Mellitus in Healthy Subjects: A 14-Year Longitudinal Cohort Study

BACKGROUND

This study aimed to investigate whether sleep duration and/or quality are associated with incident diabetes mellitus (DM).

METHODS

A total of 8816 of 10,030 healthy participants were enrolled in a prospective cohort study. Sleep duration and quality questionnaires were completed. Sleep quality was assessed using the Epworth Sleepiness Scale (ESS), which measures excessive daytime sleepiness in individuals.

RESULTS

During the 14-year follow-up period, 18% (1630/8816) were diagnosed with DM. A U-shaped relationship was observed between sleep duration and incident DM, with the highest risk observed when sleep duration was ≥10 h/day (hazard ratios (HR) 1.65 [1.25-2.17]). This group exhibited decreased insulin glycogenic index, a marker of insulin secretory function, during the study period. Among study participants who slept less than 10 h/day, the risk of incident DM increased when the ESS score was >10.

CONCLUSIONS

We found that the association between sleep duration and incident DM was U-shaped; both short (≤5 h) and long (≥10 h) sleep durations were associated with an increased risk for the occurrence of incident DM. When sleep duration was 10 h or longer per day, there was a tendency to develop DM due to decreased insulin secretory function.

Causes, Consequences, and Treatments of Sleep and Circadian Disruption in the ICU: An Official American Thoracic Society Research Statement

Background: Sleep and circadian disruption (SCD) is common and severe in the ICU. On the basis of rigorous evidence in non-ICU populations and emerging evidence in ICU populations, SCD is likely to have a profound negative impact on patient outcomes. Thus, it is urgent that we establish research priorities to advance understanding of ICU SCD. Methods: We convened a multidisciplinary group with relevant expertise to participate in an American Thoracic Society Workshop. Workshop objectives included identifying ICU SCD subtopics of interest, key knowledge gaps, and research priorities. Members attended remote sessions from March to November 2021. Recorded presentations were prepared and viewed by members before Workshop sessions. Workshop discussion focused on key gaps and related research priorities. The priorities listed herein were selected on the basis of rank as established by a series of anonymous surveys. Results: We identified the following research priorities: establish an ICU SCD definition, further develop rigorous and feasible ICU SCD measures, test associations between ICU SCD domains and outcomes, promote the inclusion of mechanistic and patient-centered outcomes within large clinical studies, leverage implementation science strategies to maximize intervention fidelity and sustainability, and collaborate among investigators to harmonize methods and promote multisite investigation. Conclusions: ICU SCD is a complex and compelling potential target for improving ICU outcomes. Given the influence on all other research priorities, further development of rigorous, feasible ICU SCD measurement is a key next step in advancing the field.

Gut microbiota: A new target of traditional Chinese medicine for insomnia

All species have a physiological need for sleep, and sleep is crucial for the preservation and restoration of many physiological processes in the body. Recent research on the effects of gut microbiota on brain function has produced essential data on the relationship between them. It has been discovered that dysregulation of the gut-brain axis is related to insomnia. Certain metabolites of gut microbiota have been linked to insomnia, and disturbances in gut microbiota can worsen insomnia. Traditional Chinese medicine (TCM) has unique advantages for the treatment of insomnia. Taking the gut microbiota as the target and determining the scientific relevance of TCM to the prevention and treatment of insomnia may lead to new concepts for the treatment of sleep disorders and improve the therapeutic effect of sleep. Taking the gut microbiota as an entry point, this paper reviews the relationship between gut microbiota and TCM, the relationship between gut microbiota and insomnia, the mechanism by which gut microbiota regulate sleep, and the mechanism by which TCM regulates gut microbiota for insomnia prevention and treatment. This review provides new ideas for the prevention and treatment of insomnia through TCM and new ideas for drug development.

Society of Anesthesia and Sleep Medicine Position Paper on Patient Sleep During Hospitalization

This article addresses the issue of patient sleep during hospitalization, which the Society of Anesthesia and Sleep Medicine believes merits wider consideration by health authorities than it has received to date. Adequate sleep is fundamental to health and well-being, and insufficiencies in its duration, quality, or timing have adverse effects that are acutely evident. These include cardiovascular dysfunction, impaired ventilatory function, cognitive impairment, increased pain perception, psychomotor disturbance (including increased fall risk), psychological disturbance (including anxiety and depression), metabolic dysfunction (including increased insulin resistance and catabolic propensity), and immune dysfunction and proinflammatory effects (increasing infection risk and pain generation). All these changes negatively impact health status and are counterproductive to recovery from illness and operation. Hospitalization challenges sleep in a variety of ways. These challenges include environmental factors such as noise, bright light, and overnight awakenings for observations, interventions, and transfers; physiological factors such as pain, dyspnea, bowel or urinary dysfunction, or discomfort from therapeutic devices; psychological factors such as stress and anxiety; care-related factors including medications or medication withdrawal; and preexisting sleep disorders that may not be recognized or adequately managed. Many of these challenges appear readily addressable. The key to doing so is to give sleep greater priority, with attention directed at ensuring that patients' sleep needs are recognized and met, both within the hospital and beyond. Requirements include staff education, creation of protocols to enhance the prospect of sleep needs being addressed, and improvement in hospital design to mitigate environmental disturbances. Hospitals and health care providers have a duty to provide, to the greatest extent possible, appropriate preconditions for healing. Accumulating evidence suggests that these preconditions include adequate patient sleep duration and quality. The Society of Anesthesia and Sleep Medicine calls for systematic changes in the approach of hospital leadership and staff to this issue. Measures required include incorporation of optimization of patient sleep into the objectives of perioperative and general patient care guidelines. These steps should be complemented by further research into the impact of hospitalization on sleep, the effects of poor sleep on health outcomes after hospitalization, and assessment of interventions to improve it.

ER proteostasis regulators cell-non-autonomously control sleep

Sleep is regulated by peripheral tissues under fatigue. The molecular pathways in peripheral cells that trigger systemic sleep-related signals, however, are unclear. Here, a forward genetic screen in C. elegans identifies 3 genes that strongly affect sleep amount: sel-1, sel-11, and mars-1. sel-1 and sel-11 encode endoplasmic reticulum (ER)-associated degradation components, whereas mars-1 encodes methionyl-tRNA synthetase. We find that these machineries function in non-neuronal tissues and that the ER unfolded protein response components inositol-requiring enzyme 1 (IRE1)/XBP1 and protein kinase R-like ER kinase (PERK)/eukaryotic initiation factor-2α (eIF2α)/activating transcription factor-4 (ATF4) participate in non-neuronal sleep regulation, partly by reducing global translation. Neuronal epidermal growth factor receptor (EGFR) signaling is also required. Mouse studies suggest that this mechanism is conserved in mammals. Considering that prolonged wakefulness increases ER proteostasis stress in peripheral tissues, our results suggest that peripheral ER proteostasis factors control sleep homeostasis. Moreover, based on our results, peripheral tissues likely cope with ER stress not only by the well-established cell-autonomous mechanisms but also by promoting the individual's sleep.

Sleep-Disordered Breathing and Chronic Respiratory Infections: A Narrative Review in Adult and Pediatric Population

Sleep-disordered breathing (SDB) comprises different diseases characterized by abnormal respiratory patterns during sleep including obstructive sleep apnea. SDB prevalence and impact in patients with chronic respiratory infections have been only marginally studied. The purpose of this narrative review is to report the prevalence and impact of SDB in chronic respiratory infections, including cystic fibrosis (CF), bronchiectasis and mycobacterial infections, and explore the possible pathophysiological mechanisms. Common pathophysiological mechanisms, underlying SDB onset in all chronic respiratory infections, include inflammation, which plays a central role, chronic nocturnal cough and pain, excessive production of mucous plugs, presence of obstructive and/or restrictive ventilatory impairment, upper airways involvement, and comorbidities, such as alteration of nutritional status. SDB may affect about 50% of patients with bronchiectasis. The severity of the disease, e.g., patients colonized with P. aeruginosa and frequent exacerbators, as well as comorbidities, such as chronic obstructive pulmonary disease and primary ciliary dyskinesia, may impact SDB onset. SDB may also frequently complicate the clinical course of both children and adults with CF, impacting the quality of life and disease prognosis, suggesting that their routine assessment should be incorporated into the clinical evaluation of patients from the first stages of the disease regardless of suggestive symptoms, in order to avoid late diagnosis. Finally, although the prevalence of SDB in patients with mycobacterial infections is uncertain, extrapulmonary manifestations, particularly nasopharyngeal locations, and concomitant symptoms, such as body pain and depression, may act as atypical predisposing factors for their development.

Sleep duration, weekend catch-up sleep, and risk of obstructive sleep apnea in relation to handgrip strength

PURPOSE

This cross-sectional study aimed to evaluate whether weekday sleep duration, weekend catch-up sleep, and risk of obstructive sleep apnea are individually and in combination associated with handgrip strength.

METHODS

Data from the Korea National Health and Nutrition Examination Survey 2019, including weekday sleep duration, weekend catch-up sleep, STOP-BANG scores, relative handgrip strength (handgrip strength divided by body mass index), and confounding factors (sociodemographic factors, health behaviors, and health and nutritional status), were evaluated in 3678 Korean adults aged 40 to 80 years. Adequate (vs. inadequate) sleep parameters were defined as weekday sleep duration (6-7 vs. ≤ 5 or ≥ 8 h), weekend catch-up sleep (presence vs. absence), and risk of obstructive sleep apnea (low vs. high based on STOP-BANG scores). Sex-specific quintiles of relative handgrip strength were categorized as high (highest 5th quintile) or low (lower 1^st to 4^th quintiles). A complex-sample logistic regression analysis was performed.

RESULTS

After adjusting for other sleep parameters and confounding variables, each adequate sleep parameter individually and collectively was associated with high relative handgrip strength (adjusted odds ratios [95% confidence interval], 1.43 [1.09, 1.89] for 6-7 h weekday sleep duration; 1.44 [1.10, 1.90] for low risk of obstructive sleep apnea; 1.72 [1.23, 2.40] for any two parameters; 1.81 [1.18, 2.79] for all parameters). The combination of adequate weekend catch-up sleep and obstructive sleep apnea risk had the highest odds ratio for high relative handgrip strength (2.36 [1.45, 3.83]).

CONCLUSIONS

Adequate weekday sleep duration, weekend catch-up sleep, and low obstructive sleep apnea risk were individually and in combination associated with high handgrip strength.

Inflammation from Sleep Fragmentation Starts in the Periphery Rather than Brain in Male Mice

Obstructive sleep apnea is increasing worldwide, leading to disordered sleep patterns and inflammatory responses in brain and peripheral tissues that predispose individuals to chronic disease. Pro-inflammatory cytokines activate the inflammatory response and are normally regulated by glucocorticoids secreted from adrenal glands. However, the temporal dynamics of inflammatory responses and hypothalamic-pituitary-adrenal (HPA) axis activation in relation to acute sleep fragmentation (ASF) are undescribed. Male C57BL/6J mice were exposed to ASF or control conditions (no ASF) over specified intervals (1, 2, 6, and 24 h) and cytokine gene expression (IL-1beta, TNF-alpha) in brain and peripheral tissues as well as serum glucocorticoid and interleukin-6 (IL-6) concentration were assessed. The HPA axis was rapidly activated, leading to elevated serum corticosterone from 1-24 h of ASF compared with controls. This activation was followed by elevated serum IL-6 concentration from 6-24 h of ASF. The tissue to first exhibit increased pro-inflammatory gene expression from ASF was heart (1 h of ASF). In contrast, pro-inflammatory gene expression was suppressed in hypothalamus after 1 h of ASF, but elevated after 6 h. Because the HPA axis was activated throughout ASF, this suggests that brain, but not peripheral, pro-inflammatory responses were rapidly inhibited by glucocorticoid immunosuppression.

Insomnia and multiple health outcomes: umbrella review of meta-analyses of prospective cohort studies

OBJECTIVES

To evaluate existing evidence of prospective cohort studies on associations between insomnia and multiple health outcomes.

STUDY DESIGN

An umbrella review of meta-analyses of prospective cohort studies.

METHODS

A systematic search was undertaken in Pubmed, Embase, Cochrane, and Web of Science from inception to October 2021 to find meta-analyses of prospective cohort studies investigating the association of insomnia with any health outcome. The summary relative risk (SRR) for each meta-analysis was recalculated with random-effects model. The methodological quality and the quality of evidence were assessed by the A Measurement Tool to Assess Systematic Reviews and Grading of Recommendations, Assessment, Development and Evaluation, respectively.

RESULTS

A total of 25 published meta-analyses of prospective cohort studies, reporting 63 SRRs for 29 unique outcomes were included. Insomnia was mainly related to cardiovascular outcomes and mental disorders. The former comprised atrial fibrillation (SRR: 1.30, 95% confidence interval: 1.26 to 1.35), cardiovascular diseases (1.45, 1.29 to 1.64), coronary heart disease (1.28, 1.10 to 1.50), myocardial infarction (1.42, 1.17 to 1.72), and stroke (1.55, 1.39 to 1.72). The latter involved alcohol abuse (1.35, 1.08 to 1.67), all mental disorders (2.16, 1.70 to 3.97), anxiety (3.23, 1.52 to 6.85), depression (2.31, 1.90 to 2.81), suicidal ideation (2.26, 1.79 to 2.86), suicidal attempt (1.99, 1.31 to 3.02), and suicidal death (1.72, 1.42 to 2.08). Besides, insomnia enhanced the risk of Alzheimer's disease (1.51, 1.06 to 2.14) and hyperlipidemia (1.64, 1.53 to 1.76).

CONCLUSION

Insomnia exhibits considerable adverse outcomes, primarily comprises cardiovascular outcomes and mental disorders, but further studies with robustly designed trials are needed to draw firmer conclusions.

Pre-sleep affect predicts subsequent REM frontal theta in nonlinear fashion

Pre-sleep affect is thought to influence sleep, but associations with both sleep architecture and the electroencephalographic (EEG) power spectrum are mixed. In this pre-registered study, we assessed negative valence and arousal 1 h pre-sleep in 52 adults drawn from the community, then recorded one night of polysomnography (PSG) in participants' own homes. Pre-sleep affect was not associated with nonrapid eye movement (NREM) or rapid eye movement (REM) sleep architecture parameters, but we did observe inverted U-shaped relationships between both negative valence and arousal and REM frontal theta power, such that theta power was highest at moderate negative valence and arousal, and lowest at either affective extreme. When entered into a model together, both valence and arousal accounted for independent variance. Secondary analyses revealed a similar quadratic association with pre-sleep positive valence, suggesting a nonspecific effect of pre-sleep valence on REM frontal theta. Robustness checks confirmed that effects were not explained by homeostatic sleep pressure or sleep timing. Our results suggest that mixed findings in the literature may reflect different ends of a quadratic function, underscoring the importance of assessing how different components of pre-sleep affect relate to sleep.

Association between daytime napping and cognitive impairment among Chinese older population: a cross-sectional study

BACKGROUND

Both napping and nighttime sleep duration have been reported to be associated with cognitive function in older adults, whereas little is known about the association between daytime napping and cognitive impairment in different nighttime sleep duration subgroups. This study aimed to explore the correlation between daytime napping and cognitive impairment across nighttime sleep duration subgroups.

METHODS

A cross-sectional study was conducted by using the fourth survey of China Health and Retirement Longitudinal Study (CHARLS). We utilized the Mini-Mental State Examination (MMSE) scale to define cognitive impairment, and the daytime napping and nighttime sleep duration was self-reported by individuals. We applied the Restricted Cubic Spline (RCS) to analysis the dose-response relationships between daytime napping and cognitive impairment. And the multivariate Logistic Regression Model (LRM) was performed to evaluate the association of daytime napping and cognitive impairment.

RESULTS

A total of 3,052 individuals were included, of which 769 were cognitive impairment. The RCS showed there were non-linear association between daytime napping and cognitive impairment in all participants group and longer nighttime sleep duration subgroup (PNon-linear < 0.05, PDaytime napping < 0.05). The LRM revealed no napping (OR = 1.62, 95%CI 1.14-2.30) and excessive napping (1.64 95%CI 1.09-2.48) were related to cognitive impairment in longer nighttime sleep duration subgroup.

CONCLUSIONS

Daytime napping had nonlinear association with cognitive impairment in Chinese elderly population. No napping and excessive daytime napping (>90 minutes) were related to cognitive impairment in participants with 7 and more hours nighttime sleep duration.

Effect of sleep loss on pain-New conceptual and mechanistic avenues

Introduction

Sleep disturbances increase pain sensitivity in clinical and preclinical settings, but the precise mechanisms are unknown. This represents a major public health issue because of the growing sleep deficiency epidemic fueled by modern lifestyle. To understand the neural pathways at the intersection between sleep and pain processes, it is critical to determine the precise nature of the sleep disruptions that increase pain and the specific component of the pain response that is targeted.

Methods

We performed a review of the literature about sleep disturbances and pain sensitivity in humans and rodents by taking into consideration the targeted sleep stage (REMS, non-NREMS, or both), the amount of sleep lost, and the different types of sleep disruptions (partial or total sleep loss, duration, sleep fragmentation or interruptions), and how these differences might affect distinct components of the pain response.

Results

We find that the effects of sleep disturbances on pain are highly conserved among species. The major driver for pain hypersensitivity appears to be the total amount of sleep lost, while REMS loss by itself does not seem to have a direct effect on pain sensitivity. Sleep loss caused by extended wakefulness preferentially increases pain perception, whereas interrupted and limited sleep strongly dysregulates descending controls such as DNIC, especially in women.

Discussion

We discuss the possible mechanisms involved, including an increase in inflammatory processes, a loss of nociceptive inhibitory pathways, and a defect in the cognitive processing of noxious input.

Effect of weekend catch-up sleep on high-sensitivity C-reactive protein levels according to bedtime inconsistency: a population-based cross-sectional study

To investigate the associations of weekend catch-up sleep (WCS) and high-sensitivity C-reactive protein (hs-CRP) levels according to bedtime inconsistency in the Korean population. In this cross-sectional study using the Korea National Health and Nutrition Examination Survey (2016-2018) with 17,665 participants, four groups were defined: no-WCS (WCS within ± 1 h of weekday sleep time), moderate WCS (1 ≤ , < 3 h), severe WCS (≥ 3 h), and inverse WCS (≤ - 1 h). An inconsistent bedtime was defined as a > 2 h difference between weekend and weekday bedtimes. Outcomes were divided into quartiles based on the hs-CRP level: Lowest (< 0.34), Middle-low (≥ 0.34, < 0.55), Middle-high (≥ 0.55, < 1.10), Highest (≥ 1.10). Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated using multinomial logistic regression, controlling for relevant covariates. Moderate WCS was associated with a lower risk for the highest hs-CRP levels than no WCS (aOR = 0.87, 95% CI 0.78-0.97), and a similar association was observed only in participants with consistent bedtimes (aOR = 0.88, 95% CI 0.78-0.99). Significant interactions of those associations of WCS and hs-CRP levels with bedtime inconsistency were found. These findings provide evidence that people with inconsistent bedtimes would have limited protective effect of WCS on hs-CRP.

Associations between indoor light pollution and unhealthy outcomes in 2,947 adults: Cross-sectional analysis in the HEIJO-KYO cohort

Nighttime use of artificial light is usual and essential in these modern times. Although light exposure at night (LAN) is reportedly a risk factor of several diseases, epidemiological studies on indoor LAN levels are still limited. Hence, the present study aimed to measure bedroom LAN levels by using light meters in a larger sample than in previous studies, and to evaluate the associations with comprehensive health outcomes. Out of 3012 participants, 2947 (mean age, 69.3 years; female, 60.6%) completed the bedroom LAN intensity measurement. The median bedroom LAN intensity was 1.0 lux (interquartile range, 0.2-4.0 lux). In a multivariable analysis adjusted for potential confounding factors, the highest quartile group of bedroom LAN intensity had significantly higher body weight, body mass index, abdominal circumference, and low-density lipoprotein cholesterol than the lowest quartile group. The group with a median LAN intensity ≥10 lux had significantly higher white blood cell counts and had significantly lower high-density lipoprotein cholesterol levels than the group with a median LAN intensity <10 lux. In addition, the groups with median LAN intensities ≥3 and ≥10 lux had significantly higher odds ratios for sleep disturbances and depressive symptoms than the group with <3 and <10 lux, respectively. Therefore, the present study provided real-world data on bedroom LAN levels as a marker for indoor light pollution in a large sample and suggested that higher bedroom LAN levels are significantly associated with parameters of obesity, dyslipidemia, systemic inflammation, sleep disturbances, and depressive symptoms.

The effect of mindfulness training on stress and sleep quality of postmenopausal women: A systematic review and meta-analysis

INTRODUCTION

Mindfulness is an effective method for empowering women to cope with menopausal changes. This study aimed to determine the effect of mindfulness training on stress and sleep quality in postmenopausal women.

MATERIALS AND METHODS

English (PubMed, Cochrane Library, Google Scholar, Scopus, Web of Science, and CINHAL) and Persian (SID, Magiran) databases were searched until 25 June 2022, using the free and MeSH keywords included Mindfulness and Menopause. The quality of the published papers was evaluated using Cochrane Handbook for Systematic Reviews of Interventions version 5.2.0. The meta-analysis was conducted in RevMan 5.3 and the results were reported with mean difference (95% confidence interval). The quality of evidence was assessed using the GRADE approach.

RESULTS

A total of 1206 records were obtained. After removing duplicate and non-eligible records, finally five articles were included in the systematic review and meta-analysis. The results indicated that sleep quality score (SMD = -1.44; 95% CI = -2.44 to -0.46; p = 0.004) and perceived stress score (MD = -4.21; 95% CI = -6.41 to -2.00; p = 0.0002) were significantly reduced in the mindfulness training group compared to control group.

CONCLUSION

Mindfulness training is associated with improving sleep quality and perceived stress (with a low quality of evidence) in postmenopausal women. Mental health and quality of life in postmenopausal women impressively affect the community health. Given the low quality of evidence of the studies in this field, randomized controlled trials with better methodologies are suggested.

Caffeine-Induced Sleep Restriction Alters the Gut Microbiome and Fecal Metabolic Profiles in Mice

Insufficient sleep is becoming increasingly common and contributes to many health issues. To combat sleepiness, caffeine is consumed daily worldwide. Thus, caffeine consumption and sleep restriction often occur in succession. The gut microbiome can be rapidly affected by either one's sleep status or caffeine intake, whereas the synergistic effects of a persistent caffeine-induced sleep restriction remain unclear. In this study, we investigated the impact of a chronic caffeine-induced sleep restriction on the gut microbiome and its metabolic profiles in mice. Our results revealed that the proportion of Firmicutes and Bacteroidetes was not altered, while the abundance of Proteobacteria and Actinobacteria was significantly decreased. In addition, the content of the lipids was abundant and significantly increased. A pathway analysis of the differential metabolites suggested that numerous metabolic pathways were affected, and the glycerophospholipid metabolism was most significantly altered. Combined analysis revealed that the metabolism was significantly affected by variations in the abundance and function of the intestinal microorganisms and was closely relevant to Proteobacteria and Actinobacteria. In conclusion, a long-term caffeine-induced sleep restriction affected the diversity and composition of the intestinal microbiota in mice, and substantially altered the metabolic profiles of the gut microbiome. This may represent a novel mechanism by which an unhealthy lifestyle such as mistimed coffee breaks lead to or exacerbates disease.