Sleep duration, cardiovascular disease, and proinflammatory biomarkers

The Role of Sleep in Cardiovascular Disease

PURPOSE OF REVIEW

Sleep is an important component of cardiovascular (CV) health. This review summarizes the complex relationship between sleep and CV disease (CVD). Additionally, we describe the data supporting the treatment of sleep disturbances in preventing and treating CVD.

RECENT FINDINGS

Recent guidelines recommend screening for obstructive sleep apnea in patients with atrial fibrillation. New data continues to demonstrate the importance of sleep quality and duration for CV health. There is a complex bidirectional relationship between sleep health and CVD. Sleep disturbances have systemic effects that contribute to the development of CVD, including hypertension, coronary artery disease, heart failure, and arrhythmias. Additionally, CVD contributes to the development of sleep disturbances. However, more data are needed to support the role of screening for and treatment of sleep disorders for the prevention of CVD.

Association of Sleep Status With Cognitive Functions in Centenarians: Evidence From Hainan Centenarian Cohort

OBJECTIVES

This study aimed to analyze the association between sleep quality, sleep duration, and cognitive functions among centenarians.

METHODS

The baseline data of the China Hainan Centenarians Cohort Study served as the foundation for this study. Logistic regression was utilized to demonstrate the relationship between sleep status and cognitive impairment. Moreover, a canonical correlation analysis was performed to analyze the correlation between these variables.

RESULTS

A total of 994 centenarians were included. After adjustment, poor sleep quality centenarians had an odds ratio of 1.77 (95% confidence interval [CI]: 1.00-3.09) for cognitive impairment when compared to centenarians with normal sleep quality. Centenarians who slept for more than 9 hr had a stronger association with severe cognitive impairment, indicated by an odds ratio of 1.41 (95% CI: 1.02-1.96), compared to those who slept for 7-9 hr. Additionally, the canonical correlation analysis results revealed that the linear combination of sleep quality V1, primarily determined by sleep latency, daytime dysfunction, and subjective sleep quality, was associated with cognitive function; the linear combination of cognitive function W1, mainly determined by orientation, attention and calculation, and memory.

DISCUSSION

There exists a correlation between poor sleep quality and cognitive impairment in centenarians, as well as a correlation between sleep duration >9 hr at night and severe cognitive impairment. The primary cognitive domains associated with sleep quality are orientation, calculation, and memory. It is imperative to monitor and safeguard the cognitive functions linked to poor sleep quality in the older individuals, with attention to orientation, calculation, and memory.

Metabolomic profiles of sleep-disordered breathing are associated with hypertension and diabetes mellitus development

Sleep-disordered breathing (SDB) is a prevalent disorder characterized by recurrent episodic upper airway obstruction. Using data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), we apply principal component analysis (PCA) to seven SDB-related measures. We estimate the associations of the top two SDB PCs with serum levels of 617 metabolites, in both single-metabolite analysis, and a joint penalized regression analysis. The discovery analysis includes 3299 individuals, with validation in a separate dataset of 1522 individuals. Five metabolite associations with SDB PCs are discovered and replicated. SDB PC1, characterized by frequent respiratory events common in older and male adults, is associated with pregnanolone and progesterone-related sulfated metabolites. SDB PC2, characterized by short respiratory event length and self-reported restless sleep, enriched in young adults, is associated with sphingomyelins. Metabolite risk scores (MRSs), representing metabolite signatures associated with the two SDB PCs, are associated with 6-year incident hypertension and diabetes. These MRSs have the potential to serve as biomarkers for SDB, guiding risk stratification and treatment decisions.

Objectively measured prolonged sleep is associated with plasma cytokines in older adults with mild cognitive impairment

This study aimed to determine whether objective sleep time is associated with the concentrations of various plasma cytokines in older adults with mild cognitive impairment (MCI). In total, 118 adults with MCI (66 women; mean age: 75.7 years) participated in this prospective cohort study. All participants were required to wear a wristband sensor for 7.8 days, on average, every 3 months for 1 year and undergo measurement of 27 plasma cytokines using multiplex immunoassays. After adjusting for potential confounders, the associations of total sleep time with cytokine concentrations were assessed by multiple linear regression analysis. The total sleep time was significantly correlated with plasma interleukin (IL)-9 and macrophage inflammatory protein (MIP)-1β levels (r = 0.239, p = 0.009, and r = 0.242, p = 0.008, respectively). Moreover, these associations remained significant after adjusting for covariates, including demographic characteristics, lifestyle-related diseases, and apolipoprotein E status (β = 0.272, 95% confidence interval: 0.095-0.448, p = 0.003, and β = 0.27, 95% confidence interval: 0.092-0.449, p = 0.003, respectively). Thus, this study is the first to demonstrate the association between objective prolonged sleep and higher plasma IL-9 and MIP-1β levels in older adults with MCI.

Beyond sleep duration: Sleep timing is associated with BMI among Brazilian adults

OBJECTIVES

To examine the association of sleep duration and timing with BMI among adults. Also, to identify obesogenic and unhealthy behaviors (e.g.diet/sleep quality, physical activity, screen time, smoking) associated with short sleep duration and late bedtime.

PARTICIPANTS

Participants (n=755) were part of exploratory, population-based research, with data collection in a virtual environment.

METHODS

For purposes of characterizing the population we considered short sleepers<7h/night, and the population bedtime median was used to stratify participants into early and late sleepers (before and after 23:08). Student's t-test and chi-square test were performed to assess differences in characteristics between groups. Linear regression analyses were conducted to determine the association of sleep duration, bedtime, and wake-up time with BMI. Quantile regression was estimated for the 25th, 50th, and 75th quantiles to identify the distributional correlations between BMI and sleep variables. Restricted cubic splines were also used to study the shape of the association between sleep-BMI. Analyses were adjusted for potential confounding variables.

RESULTS

BMI decreased by 0.40Kg/m2 for each additional hour of sleep duration [95%CI=-0.68,-0.12,p=0.005] and increased by 0.37 kg/m2 for each additional hour of bedtime [95%CI=0.12,0.61,p=0.003]. The association between bedtime and BMI remained even after adjustment for sleep duration. These effects were higher and stronger with higher BMI values (p75th). Wake-up time did not show statistically significant associations.

CONCLUSIONS

Because we found that beyond sleep duration, bedtime was significantly associated with BMI, our data reflect the pertinence of assessing sleep timing patterns in disentangling sleep-obesity association. Insights into the characteristics, obesogenic and unhealthy behaviors related to short and late sleep may support specific strategies to prevent and treat excess body adiposity and other negative health outcomes.

Objective sleep was longitudinally associated with brain amyloid burden in mild cognitive impairment

OBJECTIVE

Understanding the longitudinal association of objective sleep and physical activity with brain amyloid burden and cortical glucose metabolism has critical clinical and public health implications for dementia prevention in later life.

METHODS

We enrolled 118 individuals aged ≥65 years with mild cognitive impairment, who were followed up on from August 2015 to September 2019. All participants continuously wore an accelerometer sensor for 7 consecutive days every 3 months and received annual 11 C-Pittsburgh compound-B and 18 F-fluorodeoxyglucose positron emission tomography (PET). Sleep and physical activity parameters were assessed using accelerometer sensor data and PET imaging was quantified using a standardized uptake-value ratio. Fifty-seven participants (48.3%) completed a lifestyle factor assessment and PET imaging over the 3-year period. A linear mixed-effects model was applied to examine the longitudinal association of sleep and physical activity parameters with PET imaging over the 3-year period, controlling for potential confounders.

RESULTS

Sleep efficiency was inversely associated with amyloid uptake in the frontal lobe. Although sleep duration was positively associated with global amyloid uptake, particularly in the frontal lobe, their impact was extremely small. However, physical activity parameters were not significantly associated with the 11 C-Pittsburgh compound-B-uptake. Furthermore, sleep and physical activity parameters were not significantly associated with cortical glucose metabolism.

INTERPRETATION

Lower sleep efficiency could be an early symptom of greater brain amyloid burden at the mild cognitive impairment stage. Therefore, the assessment of sleep may be useful for identifying individuals at higher risk for brain amyloid burden. Future longer term observational studies are required to confirm these findings.

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.

Evaluation of cellular activity in response to sleep deprivation by a comprehensive analysis of the whole mouse brain

Sleep deprivation (SD) causes several adverse functional outcomes, and understanding the associated processes can improve quality of life. Although the effects of SD on neuronal activity in several brain regions have been identified, a comprehensive evaluation of the whole brain is still lacking. Hence, we performed SD using two different methods, gentle handling and a dedicated chamber, in targeted recombination in active populations 2 (TRAP2) mice crossed with Rosa-ZsGreen reporter mice and visualized cellular activity in the whole brain. Using the semi-automated post-imaging analysis tool Slice Histology Alignment, Registration, and Cell Quantification (SHARCQ), the number of activated cells was quantified. From the analysis of 14 brain regions, cellular activity was significantly increased in the olfactory areas and decreased in the medulla by the two SD methods. From the analysis of the further subdivided 348 regions, cellular activity was significantly increased in the vascular organ of the lamina terminalis, lateral hypothalamic area, parabigeminal nucleus, ventral tegmental area, and magnocellular reticular nucleus, and decreased in the anterior part of the basolateral amygdalar nucleus, nucleus accumbens, septohippocampal nucleus, reticular nucleus of the thalamus, preoptic part of the periventricular hypothalamic nucleus, ventromedial preoptic nucleus, rostral linear nucleus raphe, facial motor nucleus, vestibular nuclei, and some fiber tracts (oculomotor nerve, genu of corpus callosum, and rubrospinal tract) by the two SD methods. Two subdivided regions of the striatum (caudoputamen and other striatum), epithalamus, vascular organ of the lamina terminalis, anteroventral preoptic nucleus, superior colliculus optic layer, medial terminal nucleus of the accessory optic tract, pontine gray, and fiber tracts (medial lemniscus, columns of the fornix, brachium of the inferior colliculus, and mammillary peduncle) were differentially affected by the two SD methods. Most brain regions detected from these analyses have been reported to be involved in regulating sleep/wake regulatory circuits. Moreover, the results from the connectivity analysis indicated that the connectivity of cellular activity among brain regions was altered by SD. Together, such a comprehensive analysis of the whole brain is useful for understanding the mechanisms by which SD and/or sleep disruption affects brain function.

Sleep Duration and Chronic Disease Among Older Native Hawaiians or Other Pacific Islanders and Asians: Analysis of the Behavioral Risk Factor Surveillance System

OBJECTIVES

Older adults are particularly vulnerable to unhealthy sleep. This study examines the relationship between sleep duration and chronic diseases among older Native Hawaiians or Other Pacific Islanders (NHOPIs) and identifies variations with older Asians.

METHODS

In this cross-sectional study, data were analyzed using the 2016 Behavioral Risk Factor Surveillance System. The total sample of adults 50 years and older included 1277 NHOPIs and 4655 Asians. Weighted, survey logistic regressions were employed to analyze the relationship between sleep duration (i.e., short, healthy, and long) and seven chronic diseases: coronary heart disease, stroke, heart attack/myocardial infarction, pre-diabetes, diabetes, chronic obstructive pulmonary disease, and depressive disorder. Sleep duration was categorized into short sleep (SS; ≤ 6 h), healthy sleep (7-8 h), and long sleep (LS; ≥ 9 h), with healthy sleep as the reference group.

RESULTS

Among NHOPIs, SS and LS were significantly related to stroke (OR 3.19, 95% CI: 1.35-7.53 for SS and OR 9.52, 95% CI: 2.99-30.34 for LS) and SS was associated with pre-diabetes (OR 2.22 CI: 1.07-4.59), after adjusting for all covariates. In contrast, Asians with SS and LS reported higher odds of depression (OR 2.40, 95% CI: 1.20-4.79 and OR 5.03, 95% CI: 1.57-16.13, respectively).

CONCLUSIONS

Findings suggest older NHOPIs with SS or LS experience worse health. NHOPIs and Asians varied on the relationship between sleep and chronic disease, underscoring the need to disaggregate Asian/NHOPI data to understand health disparities.

Association Between Insomnia Symptoms and Trajectory With the Risk of Stroke in the Health and Retirement Study

BACKGROUND AND OBJECTIVES

Insomnia is a common condition affecting more than a third of the US population. However, the link between insomnia symptoms and stroke is understudied and the underlying mechanism remains unclear. This study aimed to investigate the relationship between insomnia symptoms and the incidence of stroke.

METHODS

The Health and Retirement Study, a survey of Americans older than 50 years and their spouses, from 2002 to 2020 was used as the data source. Only those who were stroke-free at baseline were included in this study. The exposure variable was insomnia symptoms and was derived from self-reported sleep-related factors including difficulty initiating sleep, difficulty maintaining sleep, waking up too early, and nonrestorative sleep. Repeated-measures latent class analysis was used to identify insomnia trajectories over time. To investigate the relationship between insomnia symptoms and stroke events reported during the follow-up period, Cox proportional hazards regression models were used. Mediation analyses of comorbidities were performed using causal mediation within a counterfactual framework.

RESULTS

A total of 31,126 participants were included with a mean follow-up of 9 years. The mean age was 61 years (SD = 11.1) and 57% were females. Insomnia symptom trajectories remained constant over time. Compared with those with no insomnia symptoms, an increased risk of stroke was observed for those with insomnia symptom scores ranging from 1 to 4 and 5 to 8 (hazard ratio (HR) = 1.16, 95% confidence interval (CI) 1.02-1.33) and (HR = 1.51, 95% CI 1.29-1.77), respectively, indicating a dose-response relationship. The association was stronger in participants younger than 50 years (HR = 3.84, 95% CI 1.50-9.85) than in those aged 50 years and older (HR = 1.38, 95% CI 1.18-1.62), comparing those with insomnia symptoms ranging from 5 to 8 with those with no insomnia symptoms. This association was mediated by diabetes, hypertension, heart disease, and depression.

DISCUSSION

Insomnia symptoms were associated with an increased risk of stroke, especially in adults younger than 50 years, and the risk was mediated by certain comorbidities. Increased awareness and management of insomnia symptoms may contribute to the prevention of stroke occurrence.

Metabolomic Profiles of Sleep-Disordered Breathing are Associated with Hypertension and Diabetes Mellitus Development: the HCHS/SOL

Sleep-disordered breathing (SDB) is a prevalent disorder characterized by recurrent episodic upper airway obstruction. In a dataset from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), we applied principal component analysis (PCA) on seven measures characterizing SDB-associated respiratory events. We estimated the association of the top two SDB PCs with serum levels of 617 metabolites, in both single-metabolite analysis, and a joint, penalized regression analysis using the least absolute shrinkage and selection operator (LASSO). Discovery analysis included n = 3,299 HCHS/SOL individuals; associations were validated in a separate dataset of n = 1,522 HCHS/SOL individuals. Seven metabolite associations with SDB PCs were discovered and replicated. Metabolite risk scores (MRSs) developed based on LASSO association results and representing metabolite signatures associated with the two SDB PCs were associated with 6-year incident hypertension and incident diabetes. MRSs have the potential to serve as biomarkers for SDB, guiding risk stratification and treatment decisions.

The relationship between sleep and salivary and serum inflammatory biomarkers in adolescents

Objectives

Poor sleep behavior can trigger an inflammatory response and contribute to the development of inflammatory diseases. Cytokines can act as indicators of inflammation and may precede the onset of inflammatory diseases. This study aimed to determine the association between sleep timing parameters (bedtime, sleep duration, sleep debt, and social jetlag) and the levels of nine serum and salivary inflammatory and metabolic biomarkers.

Methods

Data were collected from 352 adolescents aged 16-19 years enrolled in Kuwait's public high schools. The levels of C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), adiponectin, leptin, and insulin were measured from saliva and serum samples. We conducted mixed-effect multiple linear regression modeling to account for the school variable as a random effect to assess the relationship between the sleep variables and salivary and serum biomarkers. Mediation analysis was conducted to check if BMI was a mediator between bedtime and the biomarkers.

Results

There was a statistically significant elevation in serum IL-6 level associated with later bedtime (0.05 pg./mL, p = 0.01). Adolescents with severe sleep debt of ≥2 h had an increase in salivary IL-6 biomarker levels (0.38 pg./mL, p = 0.01) compared to those who had sleep debt of <1 h. Adolescents with sleep debt of ≥2 h had significantly higher levels of serum CRP (0.61 μg/mL, p = 0.02) than those without sleep debt. Additionally, we found that the inflammatory biomarkers (CRP, IL-6, IL-8, IL-10, VEGF, and MCP-1) and metabolic biomarkers (adiponectin, leptin, and insulin) had more statistically significant associations with the bedtime variables than with sleep duration variables. CRP, IL-6, and IL-8 were associated with sleep debt, and IL-6, VEGF, adiponectin, and leptin levels were associated with social jetlag. BMIz was a full mediator in the relationship between late bedtime and increased serum levels of CRP, IL-6, and insulin.

Conclusion

Adolescents who go to bed at or later than midnight had dysregulated levels of salivary and serum inflammatory biomarkers, suggesting that disrupted circadian rhythm can trigger higher levels of systemic inflammation and potentially exacerbate chronic inflammation and the risk of metabolic diseases.

The prevalence and risk factors of sleep disturbances in surgical patients: A systematic review and meta-analysis

Determining the prevalence and risk factors related to sleep disturbance in surgical patients would be beneficial for risk stratification and perioperative care planning. The objectives of this systematic review and meta-analysis are to determine the prevalence and risk factors of sleep disturbances and their associated postoperative complications in surgical patients. The inclusion criteria were: (1) patients ≥18 years old undergoing a surgical procedure, (2) in-patient population, and (3) report of sleep disturbances using a validated sleep assessment tool. The systematic search resulted in 21,951 articles. Twelve patient cohorts involving 1497 patients were included. The pooled prevalence of sleep disturbances at preoperative assessment was 60% (95% Confidence Interval (CI): 50%, 69%) and the risk factors for postoperative sleep disturbances were a high preoperative Pittsburgh sleep quality index (PSQI) score indicating preexisting disturbed sleep and anxiety. Notably, patients with postoperative delirium had a higher prevalence of pre- and postoperative sleep disturbances and high preoperative wake after sleep onset percentage (WASO%). The high prevalence of preoperative sleep disturbances in surgical patients has a negative impact on postoperative outcomes and well-being. Further work in this area is warranted.

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.

Alternate-Day Fasting Combined with Exercise: Effect on Sleep in Adults with Obesity and NAFLD

Objective: This study investigated how alternate-day fasting (ADF) combined with aerobic exercise impacts body weight and sleep in adults with non-alcoholic fatty liver disease (NAFLD). Methods: Adults with obesity and NAFLD (n = 80) were randomized into one of four groups for 3 months: combination of ADF (600 kcal “fast day,” alternated with an ad libitum intake “feast day”) and moderate-intensity aerobic exercise (five sessions per week, 60 min/session); ADF alone; exercise alone; or a no-intervention control group. Results: By month 3, body weight and intrahepatic triglyceride content decreased (p < 0.001, group × time interaction) in the combination group versus the exercise group and control group, but not versus the ADF group. Sleep quality, measured by the Pittsburgh Sleep Quality Inventory (PSQI), did not change in the combination group (baseline: 6.0 ± 0.7; month 3: 5.6 ± 0.7), ADF group (baseline: 8.9 ± 1.0; month 3: 7.5 ± 0.8), or exercise group (baseline: 6.4 ± 0.6; month 3: 6.7 ± 0.6), versus controls (baseline: 5.5 ± 0.7; month 3: 4.6 ± 0.5). Wake time, bedtime, sleep duration, and insomnia severity did not change (no group x time interaction) over the course of the study in any group. Risk for obstructive sleep apnea was present in 30% of combination subjects, 75% of ADF subjects, 40% of exercise subjects, and 75% of controls, and did not change in the intervention groups, versus controls, by month 3. No associations were observed between changes in body weight, intrahepatic triglyceride content, and any sleep outcome. Conclusions: The weight loss induced by ADF combined with exercise does not improve sleep quality, duration, insomnia severity, or risk of obstructive sleep apnea in individuals with NAFLD.

Sleep profile and the risk of cardiovascular events in patients undergoing percutaneous coronary intervention

A significant proportion of patients with coronary artery disease (CAD) who undergo percutaneous coronary intervention (PCI) suffer from physical and mental disorders which lead to the decline of sleep profile. Sleep disorders are highly prevalent in these patients. But the effect of sleep on the outcomes of post-PCI patients remains unclear. We aim to examine the individual and joint effects of sleep quality and sleep duration on the risk of adverse cardiovascular events in post-PCI patients. We included 314 participants who were diagnosed with a first CAD and underwent PCI with drug-eluting stents and followed up for a mean duration of 341 days to assess major adverse cardiovascular events (MACEs). Sleep quality, based on the Pittsburgh Sleep Quality Index, was categorized as good (a score of ≤7) or poor (>7). Sleep duration was categorized into three classes: ≤ 5, 6-8 (reference group) and ≥ 9 hours per day. The log-rank test and the Cox regression model were used for data analysis. MACEs occurred in 26 (8.3%) patients. Subjects whose sleep duration was ≤ 5 hours per day had a shorter time to MACEs than those whose sleep duration was 6-8 hours (p = 0.036). A significantly increased risk for MACEs was observed for participants with a ≤ 5 hours sleep duration (HR = 2.18, 95% CI = 1.02-4.64) after adjustment for demographic and clinical confounders. Associations between long sleep duration (≥ 9 hours), sleep quality, or their joint effect and MACEs were not found. This suggests the importance of considering sleep loss when developing strategies to improve health outcomes of PCI patients. And further researches are needed to examine the effects of different aspects of sleep quality on the prognosis of PCI patients and explore the reasons that lead to the decline of sleep profile.

Sleep physiology, pathophysiology, and sleep hygiene

Despite sleep's fundamental role in maintaining and improving physical and mental health, many people get less than the recommended amount of sleep or suffer from sleeping disorders. This review highlights sleep's instrumental biological functions, various sleep problems, and sleep hygiene and lifestyle interventions that can help improve sleep quality. Quality sleep allows for improved cardiovascular health, mental health, cognition, memory consolidation, immunity, reproductive health, and hormone regulation. Sleep disorders, such as insomnia, sleep apnea, and circadian-rhythm-disorders, or disrupted sleep from lifestyle choices, environmental conditions, or other medical issues can lead to significant morbidity and can contribute to or exacerbate medical and psychiatric conditions. The best treatment for long-term sleep improvement is proper sleep hygiene through behavior and sleep habit modification. Recommendations to improve sleep include achieving 7 to 9 h of sleep, maintaining a consistent sleep/wake schedule, a regular bedtime routine, engaging in regular exercise, and adopting a contemplative practice. In addition, avoiding many substances late in the day can help improve sleep. Caffeine, alcohol, heavy meals, and light exposure later in the day are associated with fragmented poor-quality sleep. These sleep hygiene practices can promote better quality and duration of sleep, with corresponding health benefits.

Self-Reported Sleep Disturbance is an Independent Predictor of All-Cause Mortality and Respiratory Disease Mortality in US Adults: A Population-Based Prospective Cohort Study

Objective: Self-reported sleep disturbance is common but its association with mortality has rarely been investigated. Methods: This prospective cohort analysis included 41,257 participants enrolled in the National Health and Nutrition Examination Survey from 2005 to 2018. Self-reported sleep disturbance in the present study refers to the patients who have ever consulted doctors or other professionals for trouble sleeping. Univariate and multivariate survey-weighted Cox proportional hazards models were used to evaluate the association of self-reported sleep disturbance with all-cause and disease-specific mortality. Results: Approximately 27.0% of US adults were estimated to have self-reported sleep disturbance. After adjusting for all sociodemographic variables, health behavioral factors, and common comorbidities, participants with self-reported sleep disturbance tend to have higher all-cause mortality risk with a hazard ratio (HR) of 1.17 (95% CI, 1.04-1.32) and chronic lower respiratory disease mortality risk (HR, 1.88; 95% CI, 1.26-2.80), but not cardiovascular disease mortality risk (HR, 1.19; 95% CI, 0.96-1.46) and cancer mortality risk (HR, 1.10; 95% CI, 0.90-1.35). Conclusion: Self-reported sleep disturbance could be associated with higher mortality in adults, and may need to be paid more attention in public health management.

[Chronic sleep restriction in rats leads to a weakening of compensatory reactions in response to acute sleep deprivation]

OBJECTIVE

To identify features in the compensatory mechanisms of sleep regulation in response to acute sleep deprivation after chronic sleep restriction in rats.

MATERIAL AND METHODS

Male Wistar rats 7-8 months old underwent 5-day sleep restriction: 3 h of sleep deprivation and 1 h of sleep opportunity repeating throughout each day. Six-hour acute total sleep deprivation was performed at the beginning of daylight hours on the 3rd day after sleep restriction. Polysomnogramms were recorded throughout the day before chronic sleep restriction, on the 2nd recovery day after chronic sleep restriction and after acute sleep deprivation. The control group was not subjected to chronic sleep restriction.

RESULTS

The animals after chronic sleep restriction had the compensatory increase in total sleep time in response to acute sleep deprivation weaker than in control animals. Animals after sleep restriction had the compensatory increase in the time of slow-wave sleep (SWS) only in the first 6 hours after acute sleep deprivation, whereas in control animals the period of compensation of SWS lasted 12 hours. A compensatory increase in slow-wave activity (SWA) was observed in both groups of animals, but in animals experiencing chronic sleep restriction the amplitude of SWA after acute sleep deprivation was less than in control animals. A compensatory increase in REM sleep in sleep restricted animals occurred immediately after acute sleep deprivation and coincides with a compensatory increase in SWS and SWA, whereas in control conditions these processes are spaced in time.

CONCLUSION

Compensatory reactions in response to acute sleep deprivation (sleep homeostasis) are weakened in animals subjected to chronic sleep restriction, as the reaction time and amplitude are reduced.

Prevalence and associated factors of cognitive impairment among the elderly population: A nationwide cross-sectional study in China

Background

Cognitive impairments are associated with increased risk for progression to dementia. In China, limited surveys have been conducted to estimate the national prevalence and risk factors associated with cognitive impairment in China. This study aims to assess the national prevalence and modifiable risk factors for cognitive impairments in the Chinese elderly population.

Methods

This cross-sectional study was based on the 2018 China Health and Retirement Longitudinal Study. The Mini Mental State Examination (MMSE) is recommended to test for cognitive impairment. Univariate and multivariate logistic regression models were used in assessing risk factors for cognitive impairments in the Chinese elderly population.

Results

A total of 3768 participants aged 60 years or older were enrolled in this study. The national prevalence of cognitive impairments was 22.24% in China, and the prevalence of cognitive impairment was higher in the south-west region than in the north region (29.94 vs. 16.53%, p < 0.05). The risk for cognitive impairments was higher in the following participants: not married or not living with spouse relative to married with spouse present (OR = 1.39, 95% CI, 1.15-1.70; p = 0.001), nap duration of ≥ 90 min relative to 30-60 min (OR = 1.54, 95% CI, 1.20-1.98; p = 0.001), sleep duration of ≥ 8 h relative to 6-8 h (OR = 1.73, 95% CI, 1.29-2.31; p < 0.001), and depression relative to no depression (OR = 1.67, 95% CI, 1.41-1.97; p < 0.001). The risk of cognitive impairment was lower in participants living in the urban areas relative to the rural areas (OR = 0.57, 95% CI, 0.47-0.69; p < 0.001) and consuming alcohol once a month relative to never consuming alcohol (OR = 0.69, 95% CI, 0.51-0.94; p = 0.02).

Conclusion

Cognitive impairment prevalence was high in the Chinese elderly population. The potentially modifiable risk factors for cognitive impairment should be further assessed in the development of interventions for the elderly Chinese population.

Sleep duration and risk of cardio-cerebrovascular disease: A dose-response meta-analysis of cohort studies comprising 3.8 million participants

Background

The effect of extreme sleep duration on the risk of cardiovascular and cerebrovascular diseases (CCDs) remains debatable. The pathology of CCDs is consistent in some respects (e.g., vascular factors), suggesting that there may be an overlapping range of sleep duration associated with a low risk of both diseases We aimed to quantify the dose-response relationship between sleep duration and CCDs.

Study objective

To explore whether there is an optimal sleep duration (SD) in reducing the risk of CCDs.

Methods

PubMed and EMBASE were searched until June 24, 2022 to include cohort studies that investigated the longitudinal relationships of SD with incident CCDs, including stroke and coronary heart disease (CHD). The robusterror meta-regression model (REMR model) was conducted to depict the dose-response relationships based on multivariate-adjusted risk estimates.

Results

A total of 71 cohorts with 3.8 million participants were included for meta-analysis, including 57 for cardiovascular diseases (CVD) and 29 for cerebrovascular disease. A significant U-shaped relationship was revealed of nighttime sleep duration with either cardiovascular or cerebrovascular disease. The nighttime sleep duration associated with a lower risk of CVD was situated within 4.3–10.3 h, with the risk hitting bottom at roughly 7.5 h per night (pnon–linearity &lt; 0.0001). Sleep duration associated with a lower risk of cerebrovascular diseases ranges from 5 to 9.7 h per night, with the inflection at 7.5 h per night (pnon–linearity = 0.05). Similar non-linear relationship exited in daily sleep duration and CCDs. Other subgroup analyses showed non-linear relationships close to the above results.

Conclusion

Rational sleep duration (7.5 h/night) is associated with a reduced risk of cardio-cerebrovascular disease for adults.

Associations of sleep timing and time in bed with dementia and cognitive decline among Chinese older adults: A cohort study

BACKGROUND

The longitudinal associations of sleep timing and time in bed (TIB) with dementia and cognitive decline in older adults are unclear.

METHODS

This population-based cohort study used data from 1982 participants who were aged ≥60 years, free of dementia, and living in rural communities in western Shandong, China. At the baseline (2014) and follow-up (2018) examinations, sleep parameters were assessed using standard questionnaires. Cognitive function was measured using the Mini-Mental State Examination (MMSE). Dementia was diagnosed following the DSM-IV criteria, and the NIA-AA criteria for Alzheimer disease (AD). Data were analyzed using restricted cubic splines, Cox proportional-hazards models, and general linear models.

RESULTS

During the mean follow-up of 3.7 years, dementia was diagnosed in 97 participants (68 with AD). Restricted cubic spline curves showed J-shaped associations of sleep duration, TIB, and rise time with dementia risk, and a reverse J-shaped association with mid-sleep time. When sleep parameters were categorized into tertiles, the multivariable-adjusted hazard ratio (HR) of incident dementia was 1.69 (95%CI 1.01-2.83) for baseline sleep duration >8 hours (vs. 7-8 h), 2.17 (1.22-3.87) for bedtime before 9 p.m. (vs. 10 p.m. or later), and 2.00 (1.23-3.24) for mid-sleep time before 1 a.m. (vs. 1-1.5 a.m.). Early bedtime and mid-sleep time were significantly associated with incident AD (HR range: 2.25-2.51; p < 0.05). Among individuals who were free of dementia at follow-up, baseline long TIB, early bedtime and mid-sleep time, early and late rise time, and prolonged TIB and advanced bedtime and mid-sleep time from baseline to follow-up were associated with a greater decline in MMSE score (p < 0.05). These associations with cognitive decline were statistically evident mainly among men or participants who were aged 60-74 years.

CONCLUSIONS

Long TIB and early sleep timing are associated with an increased risk of dementia, and the associations with greater cognitive decline are evident only among older people aged 60-74 years and men.

Can physical activity eliminate the mortality risk associated with poor sleep? A 15-year follow-up of 341,248 MJ Cohort participants

BACKGROUND

This study examined the joint associations of sleep patterns and physical activity (PA) with all-cause, cardiovascular disease (CVD), and cancer mortality.

METHODS

A total of 341,248 adults (mean age = 39.7 years; men: 48.3%) were included in the study, with a 15-year follow-up. Participants reported sleep duration and disturbances (difficulty falling asleep, easily awakened, or use of sleeping medication). PA was classified into 4 levels: <7.5, 7.5-14.9, 15.0-29.9, and ≥30.0 metabolic equivalent hours per week (MET-h/week). To understand the joint associations of sleep patterns and PA with mortality, Cox proportional hazard models were conducted, with exposure variables combining sleep duration/disturbances and PA.

RESULTS

Compared with the reference group (sleeping 6-8 h/day), individuals who slept >8 h/day had higher risk for all-cause mortality (hazard ratio (HR) = 1.307, 95% confidence interval (95%CI): 1.248-1.369), CVD mortality (HR = 1.298, 95%CI: 1.165-1.445), and cancer mortality (HR = 1.128, 95%CI: 1.042-1.220). Short sleep duration was not associated with mortality risk. Increased risk of all-cause and CVD mortality was found in participants who had difficulty falling asleep (HR = 1.120, 95%CI: 1.068-1.175; HR = 1.163, 95%CI: 1.038-1.304, respectively), and used sleeping medication (HR = 1.261, 95%CI: 1.159-1.372; HR = 1.335, 95%CI: 1.102-1.618, respectively) compared with those who slept well. Long sleep duration and sleep disturbances were not associated with risk of all-cause and CVD mortality among individuals achieving a PA level of ≥15 MET-h/week, and in particular among those achieving ≥30 MET-h/week.

CONCLUSION

Long sleep duration, difficulty falling asleep, and use of sleeping medication were related to a higher risk of death. Being physically active at a moderate intensity for 25-65 min/day eliminated these detrimental associations.

Adding Insult to Injury: Sleep Deficiency in Hospitalized Patients

Sleep deficiency is a common problem in the hospital setting. Contributing factors include preexisting medical conditions, illness severity, the hospital environment, and treatment-related effects. Hospitalized patients are particularly vulnerable to the negative health effects of sleep deficiency that impact multiple organ systems. Objective sleep measurement is difficult to achieve in the hospital setting, posing a barrier to linking improvements in hospital outcomes with sleep promotion protocols. Key next steps in hospital sleep promotion include improvement in sleep measurement techniques and harmonization of study protocols and outcomes to strengthen existing evidence and facilitate data interpretation across studies.

The relationships between sleep disturbance and falls: A systematic review

The purpose of this systematic review was to examine critically the literature that addresses the association between sleep disturbance and falls. Electronic databases OVID MEDLINE, PubMed, and CINAHL were searched using MeSH terms "sleep" and "accidental falls." Search limits included adults, humans, and English. The articles selected for the final sample were assessed for methodological quality. Eleven key attributes of sleep disturbance were extracted. The search yielded 177 articles from OVID MEDLINE, 124 from PubMed, and 46 from CINAHL. The final sample included 42 papers. The mean methodological quality score was 7.5 (range 2-10). Those who self-report >11 h or ≤5 h of nocturnal sleep duration may have a greater fall risk, but variations in cutoff points, study designs, and data collection methods contribute to difficulty in comparing study results. Subjective sleep fragmentation is associated with falls. The few studies on obstructive sleep apnea and insomnia demonstrate evidence of an increased risk for falls. It remains unclear whether daytime sleepiness, self-reported sleep quality, snoring, or napping are associated with falls, since some but not all studies demonstrate an association and the study quality did not differ.

Associations between COVID-19 related stigma and sleep quality among COVID-19 survivors six months after hospital discharge

BACKGROUND

Many COVID-19 survivors reported stigmatization after recovery. This study investigated the association between stigma (discrimination experiences, self-stigma and perceived affiliate stigma) and sleep quality among COVID-19 survivors six months after hospital discharge.

METHODS

Participants were recovered adult COVID-19 survivors discharged between February 1 and April 30, 2020. Medical staff of five participating hospitals approached all discharged COVID-19 period during this period. A total of 199 participants completed the telephone interview during July to September, 2020. Structural equation modeling was performed to test the hypothesize that resilience and social support would mediate the associations between stigma and sleep quality.

RESULTS

The results showed that 10.1% of the participants reported terrible/poor sleep quality, 26.1% reported worse sleep quality in the past week when comparing their current status versus the time before COVID-19. After adjusting for significant background characteristics, participants who had higher number of discrimination experience, perceived stronger self-stigma and stronger perceived affiliate stigma reported poorer sleep quality. Resilience and social support were positively and significantly associated with sleep quality. The indirect effect of self-stigma on sleep quality through social support and resilience was significant and negative. Perceived affiliate stigma also had a significant and negative indirect effect on sleep quality through social support and resilience.

CONCLUSIONS

Various types of stigma after recovery were associated with poor sleep quality among COVID-19 survivors, while social support and resilience were protective factors. Resilience and social support mediated the associations between self-stigma/perceived affiliate stigma and sleep quality.

U-shaped association between sleep duration and subjective cognitive complaints in Chinese elderly: a cross-sectional study

BACKGROUND

Subjective cognitive decline (SCD) may be the early screening signal to distinguish susceptible population with Alzheimer's disease (AD) and mild cognitive impairment (MCI). Subjective cognitive complaints (SCCs) have been proved strongly associated with SCD. This study aimed to explore the association between sleep duration and SCCs in the Chinese elderly.

METHODS

We conducted a cross-sectional study involving 688 participants aged 60 years and older in Guangdong Province, China. SCCs were assessed by the Subjective Cognitive Decline questionnaire 9 (SCD-Q9), which contained 9 items with two dimensions, including the overall memory function and time comparison (OMTC) and daily activity ability (DAA). Restricted cubic splines and generalized additive model (GAM) were used to fit the association between sleep duration and SCD-Q9 score.

RESULTS

There were significant U-shaped associations between sleep duration and overall score of SCD-Q9 (EDF = 3.842, P < 0.001), as well as the OMTC dimension (EDF = 4.471, P < 0.001) in the age- and gender-adjusted GAM. The lowest points on the overall score of SCD-Q9 and OMTC score were observed in those sleeping 8 h per night. After further adjusting for other demographic characteristics, lifestyle behaviors, hypertension and diabetes, the U-shaped associations between sleep duration and the overall score of SCD-Q9 (EDF = 3.575, P = 0.004), sleep duration and the OMTC score (EDF = 4.478, P = 0.010) were still found. The daily activity ability (DAA) score was also non-linear associated with sleep duration both in the age- and gender-adjusted GAM (EDF = 2.314, P < 0.001) and further adjusted GAM (EDF = 2.080, P = 0.010).

CONCLUSIONS

Both longer sleep duration (> 8 h) and shorter duration (< 8 h) were linked to worse SCCs. Future studies should explore the protective effect of managing sleep duration on SCD and its progression to dementia.

Relationship of sleep duration with the risk of stroke incidence and stroke mortality: an updated systematic review and dose-response meta-analysis of prospective cohort studies

BACKGROUND

The relationship between inappropriate sleep duration with stroke incidence and mortality remains controversial. We carried out dose-response meta-analysis to quantify their dose-response relationships.

METHODS

We systematically searched and extracted data from prospective cohort studies regarding sleep duration and stroke published on PubMed, EMBASE, Cochrane Library, CNKI, and Wangfang Data until October 20, 2020. We used Stata version 15.0 for meta-analysis and dose-response meta-analysis.

RESULTS

A total of 20 articles including 27 reports were included. There had fifteen and 12 reports concerning sleep duration and stroke incidence and stroke mortality respectively. Meta-analysis showed that short sleep was linked to an increased risk of stroke incidence and stroke mortality (RR: 1.33, 95% CI: 1.19-1.49 and RR: 1.37, 95% CI: 1.16-1.62 respectively). Long sleep was also associated with an increased risk of stroke incidence and stroke-related death (RR: 1.71, 95% CI: 1.50-1.95 and RR: 2.41, 95% CI: 1.87-3.09, respectively). Dose-response meta-analysis demonstrated that U-shaped relationship was observed between sleep duration and risk of all outcomes. Sleep duration presented a nonlinear relationship with stroke incidence, stroke mortality, ischemic stroke, female stroke and male stroke. Prolonged sleep was associated with an increased risk of hemorrhagic stroke and male stroke.

CONCLUSIONS

Our findings indicate that both short and long sleep duration was linked to a higher risk of stroke incidence and stroke mortality. Extended sleep duration was more associated with adverse outcomes compared with short sleep duration. Inappropriate sleep duration correlated more with ischemic stroke and an increased risk of stroke in females.

Sleep Duration/Quality With Health Outcomes: An Umbrella Review of Meta-Analyses of Prospective Studies

Background

To quantitatively evaluate the evidence of duration and quality of sleep as measured by multiple health outcomes.

Methods

This review is registered with PROSPERO, number CRD42021235587. We systematically searched three databases from inception until November 15, 2020. For each meta-analysis, the summary effect size using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval were assessed; heterogeneity, evidence of small-study effects, and excess significance bias were also estimated. According to the above metrics, we evaluated the credibility of each association.

Results

A total of 85 meta-analyses with 36 health outcomes were included in the study. We observed highly suggestive evidence for an association between long sleep and an increased risk of all-cause mortality. Moreover, suggestive evidence supported the associations between long sleep and 5 increased risk of health outcomes (stroke, dyslipidaemia, mortality of coronary heart disease, stroke mortality, and the development or death of stroke); short sleep and increased risk of overweight and/or obesity; poor sleep quality and increased risk of diabetes mellitus and gestational diabetes mellitus.

Conclusions

Only the evidence of the association of long sleep with an increased risk of all-cause mortality was graded as highly suggestive. Additional studies are needed to be conducted.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021235587

Decrease in Sleep Duration and Poor Sleep Quality over Time Is Associated with an Increased Risk of Incident Non-Alcoholic Fatty Liver Disease

The impact of changes in sleep duration and sleep quality over time on the risk of non-alcoholic fatty liver disease (NAFLD) is not known. We investigated whether changes in sleep duration and in sleep quality between baseline and follow-up are associated with the risk of developing incident NAFLD. The cohort study included 86,530 Korean adults without NAFLD and with a low fibrosis score at baseline. The median follow-up was 3.6 years. Sleep duration and quality were assessed using the Pittsburgh Sleep Quality Index. Hepatic steatosis (HS) and liver fibrosis were assessed using ultrasonography and the fibrosis-4 index (FIB-4). Cox proportional hazard models were used to determine hazard ratios (HRs) and 95% confidence intervals (Cis). A total of 12,127 subjects with incident HS and 559 with incident HS plus intermediate/high FIB-4 was identified. Comparing the decrease in sleep duration of >1 h, with stable sleep duration, the multivariate-adjusted HR (95% CIs) for incident HS was 1.24 (1.15–1.35). The corresponding HRs for incident HS plus intermediate/high FIB-4 was 1.58 (1.10–2.29). Comparing persistently poor sleep quality with persistently good sleep quality, the multivariate-adjusted HR for incident HS was 1.13 (95% CI, 1.05–1.20). A decrease in sleep duration or poor sleep quality over time was associated with an increased risk of incident NAFLD, underscoring an important potential role for good sleep in preventing NAFLD risk.

Self-reported sleep characteristics associated with dementia among rural-dwelling Chinese older adults: a population-based study

BACKGROUND

Sleep characteristics associated with dementia are poorly defined and whether their associations vary by demographics and APOE genotype among older adults are unclear.

METHODS

This population-based cross-sectional study included 4742 participants (age ≥ 65 years, 57.1% women) living in rural China. Sleep parameters were measured using the self-rated questionnaires of the Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale. Global cognitive function was assessed with the Mini-Mental State Examination (MMSE). Dementia was diagnosed following the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria, and the National Institute on Aging-Alzheimer's Association criteria for Alzheimer's disease (AD). Data were analysed using multiple logistic and general linear regression models.

RESULTS

Dementia was diagnosed in 173 participants (115 with AD). Multivariable-adjusted odds ratio (OR) of dementia was 1.71 (95%CI, 1.07-2.72) for sleep duration ≤4 h/night (vs. > 6-8 h/night), 0.76 (0.49-1.18) for > 4-6 h/night, 1.63 (1.05-2.55) for > 8 h/night, 1.11 (1.03-1.20) for lower sleep efficiency (per 10% decrease), and 1.85 (1.19-2.89) for excessive daytime sleepiness. Very short sleep duration (≤4 h/night), lower sleep efficiency, and excessive daytime sleepiness were significantly associated with being diagnosed with AD (multivariable-adjusted OR range = 1.12-2.07; p < 0.05). The associations of sleep problems with dementia and AD were evident mainly among young-old adults (65-74 years) or APOE ε4 carriers. Among dementia-free participants, these sleep characteristics were significantly associated with a lower MMSE score.

CONCLUSIONS

Self-reported sleep problems in dementia are characterized by very short or long sleep duration, low sleep efficiency, and excessive daytime sleepiness, especially among young-old people and APOE ε4 carriers.

TRIAL REGISTRATION

ChiCTR1800017758 (Aug 13, 2018).

Sleep and Stroke: Opening Our Eyes to Current Knowledge of a Key Relationship

PURPOSE OF REVIEW

To elucidate the interconnection between sleep and stroke.

RECENT FINDINGS

Growing data support a bidirectional relationship between stroke and sleep. In particular, there is strong evidence that sleep-disordered breathing plays a pivotal role as risk factor and concur to worsening functional outcome. Conversely, for others sleep disorders (e.g., insomnia, restless legs syndrome, periodic limb movements of sleep, REM sleep behavior disorder), the evidence is weak. Moreover, sleep disturbances are highly prevalent also in chronic stroke and concur to worsening quality of life of patients. Promising novel technologies will probably allow, in a near future, to guarantee a screening of commonest sleep disturbances in a larger proportion of patients with stroke. Sleep assessment and management should enter in the routinary evaluation of stroke patients, of both acute and chronic phase. Future research should focus on the efficacy of specific sleep intervention as a therapeutic option for stroke patients.

Associations of adverse childhood experiences (ACEs) with sleep duration and quality: the BCOPS study

BACKGROUND

Adverse Childhood Experiences (ACEs) are associated with numerous adverse health outcomes in adulthood. Our objective was to investigate associations between ACEs and sleep measures among 206 police officers from the Buffalo Cardio-Metabolic Occupational Police Stress study.

METHODS

ACEs (independent variable) was assessed using the ACE questionnaire. Sleep measures were assessed using the Pittsburgh Sleep Quality Index and actigraphy. ANOVA/ANCOVA were used to investigate associations between ACEs and sleep measures.

RESULTS

The mean self-reported sleep duration was significantly lower among participants who reported ≥1 ACEs compared to those who reported no ACEs (6.0 ± 0.11 vs. 6.4 ± 0.14 h; multivariate-adjusted p = 0.035). Sleep efficiency was significantly lower among participants who reported ≥1 ACEs compared to those who reported none (mean = 88.7%, 95% CI = 87.7-89.6 vs. 90.2%, 89.2-91.2; unadjusted p = 0.031) but was slightly attenuated and lost statistical significance after multivariate-adjustment (88.8%, 87.8-89.7 vs. 90.1%, 88.9-91.1; p = 0.094). Compared to participants who reported no ACEs, those who reported ≥1 ACEs had a higher mean activity index score (36.9 ± 0.96 vs. 31.2 ± 1.25; multivariate-adjusted p = 0.001); a higher mean wake after sleep onset (WASO) (44.3 ± 2.24 vs. 35.3 ± 2.92 min; multivariate-adjusted p = 0.019); and a higher sleep fragmentation index (3.8 ± 1.65 vs. 3.3 ± 1.20 unadjusted p = 0.044 and 3.8 ± 0.13 vs. 3.3 ± 0.18; multivariate-adjusted p = 0.062). Among men (but not women) who reported ≥1 ACEs, self-reported sleep duration was significantly lower (5.9 ± 0.13 vs. 6.4 ± 0.15 h; multivariate-adjusted p = 0.025) and activity index was significantly higher (39.1 ± 1.3 vs. 33.2 ± 1.51; multivariate-adjusted p = 0.004) compared to those who reported no ACEs.

CONCLUSION

Exposure to ≥1 ACE was associated with worse sleep measures.

Chronic lung diseases and sleep

Sleep is vitally important part of our life. Its quality and quantity influence all physiological processes in our organism. The relationship between the lung diseases and sleep is bidirectional - the lack of quality sleep worsens the compensation and the course of the diseases and in the same time chronic lung diseases are negatively affecting sleep quality. The coexistence of the sleep disordered breathing and lung disorders is another important issue to discuss. In case of chronic obstructive pulmonary disease the overlap with sleep disordered breathing is characterized by higher prevalence of hypercapnia and overall worse prognosis. Moreover, there is a growing body of evidence about possible links of sleep disordered breathing to lung fibrosis and tumors. The complex healthcare in patients with respiratory diseases should not omit sleep examination.

The overlooked vital sign: The importance of measuring sleep in drug development studies

Sleep is rarely considered in drug development studies. Pre-existing sleep problems or changes in sleep parameters in response to therapeutics have the potential to diminish the true utility of the agent under development. Sleep is integral to human health and affects virtually every disease. We present evidence that indicates how sleep quality and quantity can be predictive of disease risk, progression, remission, and recurrence. Supporting the premise that we should conceptualize sleep as a 'vital sign' and measure sleep as an integral component in drug development. We highlight the emergence of digital health technologies that have enabled the capture of this 'vital sign' and ask the question: why is sleep still largely ignored in drug development studies?

Investigating Causal Relationships Between Psychiatric Traits and Intracranial Aneurysms: A Bi-directional Two-Sample Mendelian Randomization Study

Background Despite psychiatric traits were associated with intracranial aneurysms (IAs) in observational studies, their causal relationships remain largely undefined. We aimed to assess the causality between psychiatric traits and IAs.

Methods We firstly collected the genome-wide association statistics of IAs (sample size, n = 79,429) and ten psychiatric traits from Europeans, including insomnia (n = 1,331,010), mood instability (n = 363,705), anxiety disorder (n = 83,566), major depressive disorder (MDD) (n = 480,359), subjective wellbeing (n = 388,538), attention deficit/hyperactivity disorder (ADHD) (n = 53,293), autism spectrum disorder (ASD) (n = 46,350), bipolar disorder (BIP) (n = 51,710), schizophrenia (SCZ) (n = 105,318), and neuroticism (n = 168,105). We then conducted a series of bi-directional two-sample Mendelian randomization (MR) analyses, of which the Robust Adjusted Profile Score (RAPS) was the primary method to estimate the causal effects between these psychiatric traits and IAs.

Results We found that insomnia exhibited a significant risk effect on IAs with the odds ratio (OR) being 1.22 (95% CI: 1.11–1.34, p = 4.61 × 10^–5) from the RAPS method. There was suggestive evidence for risk effect of mood instability on IAs (RAPS, OR = 4.16, 95% CI: 1.02–17.00, p = 0.047). However, no clear evidence of causal effects on IAs for the rest eight psychiatric traits (anxiety disorder, MDD, subjective wellbeing, ADHD, ASD, BIP, SCZ, and neuroticism) was identified. In the reverse MR analyses, no causal effects of IAs on psychiatric traits were found.

Conclusions Our findings provide strong evidence for a causal risk effect of insomnia on IAs and suggestive evidence for mood instability as a causal risk effect on IAs. These results could inform the prevention and clinical intervention of IAs.

Pre-hospital, in-hospital and post-hospital factors associated with sleep quality among COVID-19 survivors 6 months after hospital discharge: cross-sectional survey in five cities in China

BACKGROUND

Understanding factors associated with post-discharge sleep quality among COVID-19 survivors is important for intervention development.

AIMS

This study investigated sleep quality and its correlates among COVID-19 patients 6 months after their most recent hospital discharge.

METHOD

Healthcare providers at hospitals located in five different Chinese cities contacted adult COVID-19 patients discharged between 1 February and 30 March 2020. A total of 199 eligible patients provided verbal informed consent and completed the interview. Using score on the single-item Sleep Quality Scale as the dependent variable, multiple linear regression models were fitted.

RESULTS

Among all participants, 10.1% reported terrible or poor sleep quality, and 26.6% reported fair sleep quality, 26.1% reported worse sleep quality when comparing their current status with the time before COVID-19, and 33.7% were bothered by a sleeping disorder in the past 2 weeks. After adjusting for significant background characteristics, factors associated with sleep quality included witnessing the suffering (adjusted B = -1.15, 95% CI = -1.70, -0.33) or death (adjusted B = -1.55, 95% CI = -2.62, -0.49) of other COVID-19 patients during hospital stay, depressive symptoms (adjusted B = -0.26, 95% CI = -0.31, -0.20), anxiety symptoms (adjusted B = -0.25, 95% CI = -0.33, -0.17), post-traumatic stress disorders (adjusted B = -0.16, 95% CI = -0.22, -0.10) and social support (adjusted B = 0.07, 95% CI = 0.04, 0.10).

CONCLUSIONS

COVID-19 survivors reported poor sleep quality. Interventions and support services to improve sleep quality should be provided to COVID-19 survivors during their hospital stay and after hospital discharge.

The translational neuroscience of sleep: A contextual framework

Sleep is entwined across many physiologic processes in the brain and periphery, thereby exerting tremendous influence on our well-being. Yet sleep exists in a social-environmental context. Contextualizing sleep health with respect to its determinants—from individual- to societal-level factors—would enable neuroscientists to more effectively translate sleep health into clinical practice. Key challenges and opportunities pertain to (i) recognizing and exploring sleep’s functional roles, (ii) clarifying causal mechanisms in relation to key outcomes, (iii) developing richer model systems, (iv) linking models to known contextual factors, and (v) leveraging advances in multisensory technology. Meeting these challenges and opportunities would help transcend disciplinary boundaries such that social-environmental considerations related to sleep would become an ever-greater presence in the clinic.

Sleep Duration, Sleep Quality, and the Development of Nonalcoholic Fatty Liver Disease: A Cohort Study

INTRODUCTION

The longitudinal relationship between sleep duration, sleep quality, and the risk of nonalcoholic fatty liver disease (NAFLD) is unknown. We aimed to examine the association between sleep duration, sleep quality, and NAFLD development.

METHODS

Using the Pittsburgh Sleep Quality Index, sleep duration and quality were evaluated for 143,306 NAFLD-free Korean adults with a mean age of 36.6 years, who were followed for an average of 4.0 years. Hepatic steatosis (HS) was assessed using ultrasonography and liver fibrosis by the fibrosis-4 index (FIB-4) or the NAFLD fibrosis score. Flexible parametric proportional hazard models were used to determine the hazard ratios (HRs) and 95% confidence intervals.

RESULTS

There were 27,817 subjects with incident HS, of whom 1,471 had incident HS plus intermediate/high FIB-4. Multivariable-adjusted HRs (95% confidence intervals) for incident HS comparing sleep durations of ≤5, 6, 8, and ≥ 9 hours with 7 hours were 1.19 (1.14-1.23), 1.07 (1.04-1.10), 0.98 (0.94-1.02), and 0.95 (0.87-1.03), respectively. The corresponding HRs for incident HS plus intermediate/high FIB-4 were 1.30 (1.11-1.54), 1.14 (1.01-1.29), 1.11 (0.93-1.33), and 1.08 (0.71-1.63). The association between sleep duration and HS plus intermediate/high FIB-4 was inverse in individuals with good sleep quality but tended to be U-shaped in those with poor sleep quality. The results were similar if FIB-4 was replaced by the NAFLD fibrosis score.

DISCUSSION

In young adults, short sleep duration was independently associated with an increased risk of incident NAFLD with or without intermediate/high fibrosis score, suggesting a role for inadequate sleep quantity in NAFLD risk and severity.

The association of sleep quality and night sleep duration with coronary heart disease in a large-scale rural population

OBJECTIVE

The purposes of the present study were to explore independent and interactive associations between night sleep duration, night sleep quality and coronary heart disease (CHD) based on a rural population in China.

METHODS

A total of 27,935 participants (11,177 men and 16,758 women) were investigated from the Henan Rural Cohort. Information about sleep was assessed by using the Pittsburgh Sleep Quality Index (PSQI). Restricted cubic splines and logistic regression were used to estimate the relationship between night sleep duration and quality with CHD.

RESULT

Among the 27,935 participants, 1506 participants with CHD were identified. Compared with participants with scores lower than 3, the odds ratios (ORs) and 95% confidence intervals (95% CIs) of participants with score of 3-5, 6-8, ≥9 were respectively 1.42 (1.24-1.63), 1.99 (1.70-2.33), and 2.56 (2.13-3.08) with full adjustment of covariates. Compared with night sleep duration of 7 h, men and women who slept less than 5 h were 1.55 (1.11-2.17), 1.12 (0.59-2.12) and 1.80 (1.20-2.68), after being adjusted ORs (95% CIs) of the total. Moreover, the ORs and 95% CIs of CHD increased with the shortening of sleep duration at PSQI score above the highlighted levels.

CONCLUSION

Poor sleep quality and short night sleep duration were all associated with CHD in Chinese rural areas. Moreover, the association was more obvious in women. In addition, the strongest prevalence of CHD was found in short sleepers with poor sleep quality.

Sleep duration and severe periodontitis in middle-aged Japanese workers

AIM

To evaluate the association between sleep duration and severe periodontitis in Japanese workers.

MATERIALS AND METHODS

This cross-sectional study included 1130 workers (mean age 43.0 years) who underwent full-mouth periodontal examinations and health check-ups and completed a self-administered questionnaire that included questions on sleep duration. Logistic regression and a restricted cubic spline model were used to analyse the data.

RESULTS

Severe periodontitis was identified in 6.3% of the study population. Those with <5, 5-5.9, 6-6.9, 7-7.9, and ≥8 hr of sleep were 6.7%, 17.4%, 40.3%, 26.3%, and 8.9%, respectively. After adjusting for potential confounders, study participants who slept <5 hr were more likely to have severe periodontitis (adjusted odds ratio = 2.64; 95% confidence interval = 1.06-6.60) than those who slept 7-7.9 hr. The spline model, with a reference value of 399 min (the median sleep duration), showed a non-linear association between sleep duration and severe periodontitis, where an increased prevalence of severe periodontitis was observed only among those with a shorter sleep duration. The prevalence of severe periodontitis did not increase with longer sleep duration.

CONCLUSIONS

Short sleep duration was associated with severe periodontitis in this cohort of Japanese adults.

Contemporary Lifestyle and Neutrophil Extracellular Traps: An Emerging Link in Atherosclerosis Disease

Neutrophil extracellular traps (NETs) are networks of extracellular genetic material decorated with proteins of nuclear, granular and cytosolic origin that activated neutrophils expel under pathogenic inflammatory conditions. NETs are part of the host's innate immune defense system against invading pathogens. Interestingly, these extracellular structures can also be released in response to sterile inflammatory stimuli (e.g., shear stress, lipidic molecules, pro-thrombotic factors, aggregated platelets, or pro-inflammatory cytokines), as in atherosclerosis disease. Indeed, NETs have been identified in the intimal surface of diseased arteries under cardiovascular disease conditions, where they sustain inflammation via NET-mediated cell-adhesion mechanisms and promote cellular dysfunction and tissue damage via NET-associated cytotoxicity. This review will focus on (1) the active role of neutrophils and NETs as underestimated players of the inflammatory process during atherogenesis and lesion progression; (2) how these extracellular structures communicate with the main cell types present in the atherosclerotic lesion in the arterial wall; and (3) how these neutrophil effector functions interplay with lifestyle-derived risk factors such as an unbalanced diet, physical inactivity, smoking or lack of sleep quality, which represent major elements in the development of cardiovascular disease.

A Prospective Study Evaluating Sleep Quality and Disorders in Post-ARDS Patients

Introduction

Critically ill patients are predisposed to developing sleep disorders due to multiple factors like pre-existing sleep disorders, severe acute illness, sleep-altering medical interventions, and the disturbing intensive care unit (ICU) environment. In the current study, a multi-modality approach has been attempted to capture the different aspects of sleep disturbances, including insomnia (using ISI), daytime sleepiness (using ESS), sleep quality (using PSQI), sleep architecture, and SDB (using PSG).

Materials and Methods

The eligible ARDS survivor patients were updated about the study's design prior to hospital discharge. At admission, data regarding demographic details, clinical history, etiology of ARDS, and PaO₂/FiO₂ (P/F) ratio at presentation, Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores was collected. All enrolled patients were evaluated twice (early-within 7 days of admission and late-after 6 weeks of discharge) by the Richards-Campbell Sleep Questionnaire (RCSQ), Insomnia severity index (ISI), and level 1 PSG. Additionally, ESS questionnaire and the Pittsburgh Sleep Quality Index (PSQI) were also recorded in late evaluation. Abnormal sleep was defined if one or more of the following characteristics met: ISI > 15, ESS > 10, global PSQI > 5, AHI ≥ 5 events/h.

Results

Thirty patients were recruited out of the total of 88 ARDS patients screened at admission. The median (IQR) PaO₂/FiO₂ ratio and APACHE II scores were 176 (151-191.5) and 14 (14-16), respectively. The median (IQR) duration of stay in the ICU was 10 (7.3-19.5) days. The median RCSQ score in the early and late evaluation was 42 and 69, respectively. The mean ISI score in the early evaluation was 16.67 ± 4.72, which decreased to 11.70 ± 5.03 in late evaluation (p < 0.05). ISI score > 15 (clinical insomnia) was found in 18 out of 30 subjects (60%) in early evaluation and 11 out of 30 (36%) in late evaluation. During the early evaluation, sleep efficiency was low (median 59.9% and predominantly N1 and N2) which improved in late evaluation (median 80.6%). Of the 30 patients, only 4 had AHI > 5 in early evaluation and none in late evaluation. Neither of P/F ratio, SOFA, and APACHE II scores did correlate with ICU events in the early and late evaluations. Regression analysis showed subjects with ICU stay more than 10 days, duration of IMV more than 7 days, Fentanyl more than 7 mg, duration of sedative use more than 7 days was independently associated with poor objective sleep quality (low sleep efficiency, low TST and high arousal index) during the early and late evaluations after ICU discharge compared to counterparts (p value < 0.05).

Conclusion

We conclude that sleep quality in ARDS survivors was poor within 7 days of ICU discharge, characterized by severe disruption of sleep architecture and sleep-disordered breathing. After 6 weeks of ICU discharge sleep quality showed significant improvement in the N3 stage and AHI, however persistent insomnia was observed even at 6 weeks. Therefore, prior identification of risk factors and early diagnosis of sleep quality disorders in post-ARDS patients is essential.

[Modeling of chronic sleep restriction for translational studies]

OBJECTIVE

To develop of a chronic sleep restriction model in rats by repeated sleep deprivation using an orbital shaker and to determine whether this model leads to disturbances in sleep homeostatic mechanisms.

MATERIAL AND METHODS

Male Wistar rats (7-8 months old) underwent sleep restriction for five consecutive days: 3 h of sleep deprivation and 1 h of sleep opportunity repeating throughout each day. Polysomnograms were recorded telemetrically throughout the day before sleep restriction (baseline), on the 1st, 3rd, 5th day of sleep restriction and 2 days after the end of sleep restriction (recovery period).

RESULTS

During the period of sleep restriction, the total amount of slow-wave sleep (SWS) and rapid eye movement (REM) sleep decreased by 61% and 55%, respectively, compared to baseline. On the first day of recovery, amount of SWS increased mainly in the dark (active) phase of the day, while REM sleep increased in both light and dark phases; there was no marked rebound of daily SWS amount, while REM sleep increased by 30% from baseline. On the first day of recovery, an elevation of EEG beta and sigma power in sleep states was observed mainly in the light phase of the day. The loss of deep SWS throughout the sleep restriction period increased from 50% on 1st day to 75% on 5th day. The level of deep SWS remained below the baseline by 15-20% on the two subsequent days of recovery. The findings suggest that homeostatic mechanisms of SWS are persistently impaired after 5-day chronic sleep restriction. Besides, a decline of wakefulness accompanied by an increase of SWS in the active phase of the recovery period indicates a disruption in circadian rhythm.

CONCLUSION

The proposed model leads to the disruption of sleep homeostatic mechanisms, which, in turn, impede compensation of SWS loss caused by chronic insufficient sleep.

Sleep deprivation in two Saskatchewan First Nation communities: a public health consideration

Objectives

Sleep deprivation is a common problem in Canada and is associated with many health problems. More than a quarter of Canadians get fewer than the recommended sleep hours (<7 h). This paper examines the prevalence and risk factors for sleep deprivation in two First Nation communities in Saskatchewan, Canada.

Methods

The baseline cross-sectional survey was completed between 2018 and 2019 in collaboration with the two Cree First Nation communities in Saskatchewan, Canada. There were five hundred and eighty-eight participants participated in the survey from two communities. A Multivariate logistic regression model was used for analysis.

Results

The prevalence of sleep deprivation (<7 h of sleep) was 25.4%. The multivariate logistics regression revealed that middle and older age groups, visible mold in the house, and being male with nighttime insomnia symptoms were significantly associated with a higher risk of sleep deprivation among study participants in the study.

Conclusions

In these two First Nation communities, a higher proportion of the participants reported having sleep deprivation. This was a unique study, which evolved from ongoing research collaboration with two First Nation communities in Saskatchewan, Canada. Findings will be helpful in the management of patients with sleep deprivation in these communities; as well as for co-creating policy with the communities and future research priorities.

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The prevalence sleep deprivation was about 25% in these two First Nation communities.

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Association between sleep deprivation and males with nighttime insomnia observed.

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Another important finding was association between visible mold and sleep deprivation.

Association between sleep duration and augmentation index in post-menopausal women: A moderating role of depressive symptoms

OBJECTIVES

Physiological and psychological changes, including sleep disturbance and mood changes, frequently occur in post-menopausal women. We explored associations between sleep duration/quality and arterial stiffness, as well as the moderating role of depressive symptoms, in post-menopausal women.

STUDY DESIGN

This cross-sectional study utilized data obtained from 1687 post-menopausal women in the Cardiovascular and Metabolic Diseases Etiology Research Center cohort study.

MAIN OUTCOME MEASURES

Self-reported sleep was classified into short (<6 h/day), normal, and long (≥ 8 h/day) sleep durations. Poor sleep quality was operationally defined using the fatigue-related Berlin questionnaire. Depressive symptoms were assessed using the Beck Depression Index-II (BDI-II). Arterial stiffness was evaluated using the augmentation index (AI) and the HEM-9000AI system. The associations between sleep and AI were examined using generalized linear models, followed by a path model to investigate whether depressive symptoms act as an effect modifier.

RESULTS

AI (%) values for participants with poor sleep quality were higher than those for participants with normal sleep quality (β=1.53, standard error [SE]=0.59, p = 0.009). Although overall sleep duration was not associated with AI values, the severity of depressive symptoms altered the association (p-for interaction=0.021). The magnitude of the positive association between sleep duration and AI was amplified in participants with higher BDI-II scores. In participants with severe depressive symptoms (BDI-II ≥20), a long sleep duration was significantly associated with elevated AI values (β=4.80, SE=1.56, p = 0.003) compared with those with a normal sleep duration.

CONCLUSION

In post-menopausal women, poor sleep quality appears to result in an increase in arterial stiffness, and depressive symptoms seem to modify the association between sleep duration and AI. This modifying role for mental health should be considered in the association between sleep and cardiovascular health in post-menopausal women.

Residual, differential neurobehavioral deficits linger after multiple recovery nights following chronic sleep restriction or acute total sleep deprivation

STUDY OBJECTIVES

The amount of recovery sleep needed to fully restore well-established neurobehavioral deficits from sleep loss remains unknown, as does whether the recovery pattern differs across measures after total sleep deprivation (TSD) and chronic sleep restriction (SR).

METHODS

In total, 83 adults received two baseline nights (10-12-hour time in bed [TIB]) followed by five 4-hour TIB SR nights or 36-hour TSD and four recovery nights (R1-R4; 12-hour TIB). Neurobehavioral tests were completed every 2 hours during wakefulness and a Maintenance of Wakefulness Test measured physiological sleepiness. Polysomnography was collected on B2, R1, and R4 nights.

RESULTS

TSD and SR produced significant deficits in cognitive performance, increases in self-reported sleepiness and fatigue, decreases in vigor, and increases in physiological sleepiness. Neurobehavioral recovery from SR occurred after R1 and was maintained for all measures except Psychomotor Vigilance Test (PVT) lapses and response speed, which failed to completely recover. Neurobehavioral recovery from TSD occurred after R1 and was maintained for all cognitive and self-reported measures, except for vigor. After TSD and SR, R1 recovery sleep was longer and of higher efficiency and better quality than R4 recovery sleep.

CONCLUSIONS

PVT impairments from SR failed to reverse completely; by contrast, vigor did not recover after TSD; all other deficits were reversed after sleep loss. These results suggest that TSD and SR induce sustained, differential biological, physiological, and/or neural changes, which remarkably are not reversed with chronic, long-duration recovery sleep. Our findings have critical implications for the population at large and for military and health professionals.

Homeostatic sleep and body temperature responses to acute sleep deprivation are preserved following chronic sleep restriction in rats

Chronic sleep insufficiency is common in our society and has negative cognitive and health impacts. It can also alter sleep regulation, yet whether it affects subsequent homeostatic responses to acute sleep loss is unclear. We assessed sleep and thermoregulatory responses to acute sleep deprivation before and after a '3/1' chronic sleep restriction protocol in adult male Wistar rats. The 3/1 protocol consisted of continuous cycles of wheel rotations (3 h on/1 h off) for 4 days. Sleep latency in a 2-h multiple sleep latency test starting 26 h post-3/1 was unchanged, whereas non-rapid eye movement sleep (NREMS) and associated electroencephalogram delta power (a measure of sleep need) over a 24-h period beginning 54 h post-3/1 were reduced, compared to respective pre-3/1 baseline levels. However, in response to acute sleep deprivation (6 h by 'gentle handling') starting 78 h post-3/1, the compensatory rebounds in NREMS and rapid eye movement sleep (REMS) amounts and NREMS delta power were unaltered. Body temperature increased progressively across the 3/1 protocol and returned to baseline levels on the second day post-3/1. The acute sleep deprivation also increased body temperature, followed by a decline below baseline levels, with no difference between before and after 3/1 sleep restriction. Non-sleep-restricted control rats showed responses to acute sleep deprivation similar to those observed in the sleep-restricted animals. These results suggest that the process of sleep homeostasis is altered on the third recovery day after a 4-day 3/1 sleep restriction protocol, whereas subsequent homeostatic sleep and temperature responses to brief sleep deprivation are not affected.