Short sleep duration and cardiometabolic risk: from pathophysiology to clinical evidence

Timing and Length of Nocturnal Sleep and Daytime Napping and Associations With Obesity Types in High-, Middle-, and Low-Income Countries

IMPORTANCE

Obesity is a growing public health threat leading to serious health consequences. Late bedtime and sleep loss are common in modern society, but their associations with specific obesity types are not well characterized.

OBJECTIVE

To assess whether sleep timing and napping behavior are associated with increased obesity, independent of nocturnal sleep length.

DESIGN, SETTING, AND PARTICIPANTS

This large, multinational, population-based cross-sectional study used data of participants from 60 study centers in 26 countries with varying income levels as part of the Prospective Urban Rural Epidemiology study. Participants were aged 35 to 70 years and were mainly recruited during 2005 and 2009. Data analysis occurred from October 2020 through March 2021.

EXPOSURES

Sleep timing (ie, bedtime and wake-up time), nocturnal sleep duration, daytime napping.

MAIN OUTCOMES AND MEASURES

The primary outcomes were prevalence of obesity, specified as general obesity, defined as body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 30 or greater, and abdominal obesity, defined as waist circumference greater than 102 cm for men or greater than 88 cm for women. Multilevel logistic regression models with random effects for study centers were performed to calculate adjusted odds ratios (AORs) and 95% CIs.

RESULTS

Overall, 136 652 participants (81 652 [59.8%] women; mean [SD] age, 51.0 [9.8] years) were included in analysis. A total of 27 195 participants (19.9%) had general obesity, and 37 024 participants (27.1%) had abdominal obesity. The mean (SD) nocturnal sleep duration was 7.8 (1.4) hours, and the median (interquartile range) midsleep time was 2:15 am (1:30 am-3:00 am). A total of 19 660 participants (14.4%) had late bedtime behavior (ie, midnight or later). Compared with bedtime between 8 pm and 10 pm, late bedtime was associated with general obesity (AOR, 1.20; 95% CI, 1.12-1.29) and abdominal obesity (AOR, 1.20; 95% CI, 1.12-1.28), particularly among participants who went to bed between 2 am and 6 am (general obesity: AOR, 1.35; 95% CI, 1.18-1.54; abdominal obesity: AOR, 1.38; 95% CI, 1.21-1.58). Short nocturnal sleep of less than 6 hours was associated with general obesity (eg, <5 hours: AOR, 1.27; 95% CI, 1.13-1.43), but longer napping was associated with higher abdominal obesity prevalence (eg, ≥1 hours: AOR, 1.39; 95% CI, 1.31-1.47). Neither going to bed during the day (ie, before 8pm) nor wake-up time was associated with obesity.

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that late nocturnal bedtime and short nocturnal sleep were associated with increased risk of obesity prevalence, while longer daytime napping did not reduce the risk but was associated with higher risk of abdominal obesity. Strategic weight control programs should also encourage earlier bedtime and avoid short nocturnal sleep to mitigate obesity epidemic.

Beyond the AHI-pulse wave analysis during sleep for recognition of cardiovascular risk in sleep apnea patients

Recent evidence supports the use of pulse wave analysis during sleep for assessing functional aspects of the cardiovascular system. The current study compared the influence of pulse wave and sleep study-derived parameters on cardiovascular risk assessment. In a multi-centric study design, 358 sleep apnea patients (age 55 ± 13 years, 64% male, body mass index 30 ± 6 kg m^-2 , apnea-hypopnea index 13 [5-26] events per hr) underwent a standard overnight sleep recording. A novel cardiac risk index was computed based on pulse wave signals derived from pulse oximetry, reflecting vascular stiffness, cardiac variability, vascular autonomic tone and nocturnal hypoxia. Cardiovascular risk was determined using the ESC/ESH cardiovascular risk matrix, and categorized to high/low added cardiovascular risk. Comparisons between cardiac risk index and sleep parameters were performed for cardiovascular risk prediction. Apnea-hypopnea index, oxygen desaturation index and cardiac risk index were associated with high cardiovascular risk after adjustment for confounders (p = .002, .001, < .001, respectively). In a nested reference model consisting of age, gender and body mass index, adding cardiac risk index but not apnea-hypopnea index or oxygen desaturation index significantly increased the area under the receiver operating characteristic curve (p = .012, .22 and .16, respectively). In a direct comparison of oxygen desaturation index and cardiac risk index, only the novel risk index had an independent effect on cardiovascular risk prediction (p_CRI  < .001, p_ODI  = .71). These results emphasize the association between nocturnal pulse wave and overall cardiovascular risk determined by an established risk matrix. Thus, pulse wave analysis during sleep provides a powerful approach for cardiovascular risk assessment in addition to conventional sleep study parameters.

Health-Risk Behaviors and Dietary Patterns Among Jordanian College Students: A Pilot Study

Background/Aims: Health promotion and the incorporation of health-protective behaviors in people's lifestyles have a great role in enhancing individuals' overall health and well-being. College students are at increased risk of developing unhealthy dietary and lifestyle behaviors. A cross-sectional pilot study was conducted to assess the health-risk behaviors among undergraduate college students at Jordan University of Science and Technology. Methods: The final sample included 136 students, with a mean age of 21.1 ± 2.37 years, mostly females (69%). A self-reported questionnaire was used for data collection about dietary and lifestyle behaviors among college students. The questionnaire consisted of four parts: sociodemographic characteristics, body weight classifications, lifestyle behaviors, and dietary patterns and intake, and eating behaviors. Results: Most of the students did not meet the daily recommendations for fruit (76%) and vegetable (82%) intake. Males were significantly consuming fast food more frequently (p = 0.019), and smoked cigarettes (p < 0.001) or hookah (p = 0.015) more frequently than did females. Further, the majority met the recommendations for physical activity (81%), but exceeded recommendations for sedentary behavior. Females were more likely to have normal weight or be underweight (OR = 4.865), to have a fear of weight gain (OR = 3.387), and to have the recommended sleeping hours (OR = 7.685) than were males. Conclusion: The results indicate the health-risk behaviors and the gender-related differences among college students.

U-Sleep: resilient high-frequency sleep staging

Sleep disorders affect a large portion of the global population and are strong predictors of morbidity and all-cause mortality. Sleep staging segments a period of sleep into a sequence of phases providing the basis for most clinical decisions in sleep medicine. Manual sleep staging is difficult and time-consuming as experts must evaluate hours of polysomnography (PSG) recordings with electroencephalography (EEG) and electrooculography (EOG) data for each patient. Here, we present U-Sleep, a publicly available, ready-to-use deep-learning-based system for automated sleep staging ( sleep.ai.ku.dk ). U-Sleep is a fully convolutional neural network, which was trained and evaluated on PSG recordings from 15,660 participants of 16 clinical studies. It provides accurate segmentations across a wide range of patient cohorts and PSG protocols not considered when building the system. U-Sleep works for arbitrary combinations of typical EEG and EOG channels, and its special deep learning architecture can label sleep stages at shorter intervals than the typical 30 s periods used during training. We show that these labels can provide additional diagnostic information and lead to new ways of analyzing sleep. U-Sleep performs on par with state-of-the-art automatic sleep staging systems on multiple clinical datasets, even if the other systems were built specifically for the particular data. A comparison with consensus-scores from a previously unseen clinic shows that U-Sleep performs as accurately as the best of the human experts. U-Sleep can support the sleep staging workflow of medical experts, which decreases healthcare costs, and can provide highly accurate segmentations when human expertize is lacking.

High-Intensity Interval Exercise Performance and Short-Term Metabolic Responses to Overnight-Fasted Acute-Partial Sleep Deprivation

People practicing high-intensity interval exercise (HIIE) fasted during the morning hours under a lack of sleep. Such a habit may jeopardize the health benefits related to HIIE and adequate sleep. Fifteen habitually good sleeper males (age 31.1 ± 5.3 SD year) completed on a treadmill two isocaloric (500 kcal) HIIE sessions (3:2 min work:rest) averaged at 70% VO2reserve after 9-9.5 h of reference sleep exercise (RSE) and after 3-3.5 h of acute-partial sleep deprivation exercise (SSE). Diet and sleep patterns were controlled both 1 week prior and 2 days leading up to RSE and SSE. HIIE related performance and substrate utilization data were obtained from the continuous analysis of respiratory gases. Data were analyzed using repeated measures ANOVA with the baseline maximum oxygen uptake (VO2max) and body fat percentage (BF%) as covariates at p < 0.05. No difference was observed in VO2max, time to complete the HIIE, VE, RER, CHO%, and FAT% utilization during the experimental conditions. Whether attaining an adequate amount of sleep or not, the fasted HIIE performance and metabolism were not affected. We propose to practice the fasted HIIE under adequate sleep to receive the pleiotropic beneficial effects of sleep to the human body.

The Role of Sleep Curtailment on Leptin Levels in Obesity and Diabetes Mellitus

Emerging evidence has identified sleep as a significant, but modifiable, risk factor for metabolic syndrome, diabetes, and obesity. Leptin, an adipocyte-derived peptide and a regulator of food intake and energy expenditure, has been shown to be associated with a short sleep duration in the pathophysiology of obesity and consequently type 2 diabetes. This review focuses on the current evidence indicating the effects of a short sleep duration on the regulation of leptin concentration in association with obesity and diabetes mellitus. In summary, the evidence suggests that sleep deprivation, by affecting leptin regulation, may lead to obesity and consequently development of type 2 diabetes through increased appetite and food intake. However, findings on the role of leptin in diabetes due to sleep deprivation are contradictory, and further studies with larger sample sizes are needed to confirm previous findings.

Genetic liability to insomnia in relation to cardiovascular diseases: a Mendelian randomisation study

The present study aimed to determine the associations between insomnia and cardiovascular diseases (CVDs) using Mendelian randomisation (MR) analysis. As instrumental variables, we used 208 independent single-nucleotide polymorphisms associated with insomnia at the genome-wide significance threshold in a meta-analysis of genome-wide association studies in the UK Biobank and 23andMe including a total of 397 959 self-reported insomnia cases and 933 057 non-cases. Summary-level data for nine CVDs were obtained from the UK Biobank including 367 586 individuals of European ancestry. After correction for multiple testing, genetic liability to insomnia was associated with higher odds of six CVDs, including peripheral arterial disease (odd ratio (OR) 1.22; 95% confidence interval (CI), 1.21, 1.33), heart failure (OR 1.21; 95% CI, 1.13, 1.30), coronary artery disease (OR 1.19; 95% CI, 1.14, 1.25), ischaemic stroke (OR 1.15; 95% CI, 1.06, 1.25), venous thromboembolism (OR 1.13; 95% CI, 1.07, 1.19) and atrial fibrillation (OR 1.10; 95% CI, 1.05, 1.15). There were suggestive associations for aortic valve stenosis (OR, 1.17; 95% CI, 1.04, 1.32) and haemorrhagic stroke (OR 1.14; 95% CI, 1.00, 1.29) but no association for abdominal aortic aneurysm (OR, 1.14, 95% CI, 0.98, 1.33). The patterns of associations remained with mild attenuation in multivariable MR analyses adjusting for genetically correlated phenotypes and potential mediators, including sleep duration, depression, body mass index, type 2 diabetes and smoking. The present MR study suggests potential causal associations of genetic liability to insomnia with increased risk of a broad range of CVDs.

Challenges in ischaemic heart disease: not sleeping enough, not brushing your teeth, and skipping breakfast-three ways of increasing your risk of myocardial infarction?

Despite optimal medical therapies, there is currently a persistent residual cardiovascular risk. The most likely pathway responsible for this residual risk has been identified in the inflammatory state. Recent studies have confirmed that inflammation increases cardiovascular risk independently from LDL cholesterol levels. Addressing traditional risk factors, such as obesity, cigarette smoking, diabetes, arterial hypertension, and dyslipidaemia, also provides an important reduction of the levels of inflammation. Nonetheless, inflammation is also a target for specific and focused therapeutic interventions. Recent studies have outlined an association between oral hygiene, sleep deprivation, and nutritional patterns on the one hand, with the development of multi-districts atherosclerosis and/or adverse cardiovascular events on the other. These lifestyle patterns appear to be involved in fostering inflammation associated with atherosclerosis. There is, however, a persistent need for further studies to clarify whether such associations with cardiovascular disease are direct and causal, and if they are all channelled through vascular inflammation.

Diagnostic and Therapeutic Approach to Sleep Disorders, High Blood Pressure and Cardiovascular Diseases: A Consensus Document by the Italian Society of Hypertension (SIIA)

Hypertension is a major contributor to fatal/nonfatal cardiovascular diseases, and timely identification and appropriate management of factors affecting hypertension and its control are mandatory public health issues. By inducing neurohormonal alterations and metabolic impairment, sleep disorders have an impact on a variety of cardiovascular risk factors, including hypertension, and ultimately increase the risk of cardiovascular events. There is evidence that qualitative and quantitative sleep disorders are associated with resistant hypertension and with impaired circadian blood pressure variations. However, sleep disturbances are often unrecognized, or heterogeneity exists in their management by non-specialists in the field. This document by the Italian Society of Hypertension summarizes the updated evidence linking sleep disorders to hypertension and cardiovascular diseases, the major underlying mechanisms, and the possible management strategies. A simplified, evidence-based diagnostic and therapeutic algorithm for comorbid hypertension and common sleep disorders, namely obstructive sleep apnoea and insomnia, is proposed.

Cardiovascular Autonomic Control, Sleep and Health Related Quality of Life in Systemic Sclerosis

Chronic pain and dysautonomic symptoms deteriorate Systemic sclerosis (SSc) patients’ health-related quality of life with serious repercussions on social life and even on sleep. Heart Rate Variability (HRV) analysis can identify cardiovascular autonomic control impairment in subclinical condition. The aim of the present observational cross-sectional study was to assess the relationship between dysautonomic symptoms, quality of life status and cardiovascular autonomic profile. ECG and respiration were recorded at rest in 20 SSc patients. HRV analysis was performed using two different approaches: Linear spectral analysis and non-linear symbolic analysis. Pain was evaluated using the Numeric Rating Scale (NRS) and 3 questionnaires were administered for the evaluation of sleep quality (PSQI), mood tone (PHQ-9) and disability (HAQ). We found that sleep impairment was related to sympathetic predominance at rest measured as low-frequency/high-frequency ratio (LF/HF) (r = 0.48 and p = 0.033); poorer sleep quality was related to higher pain values (r = 0.48 and p = 0.034) and depressive symptoms (r = 0.82 and p < 0.01); higher pain scores were related to higher cardiovascular vagal modulation and higher disability indexes (r = 0.47 and p = 0.038 & r = 0.55 and p = 0.012, respectively). In conclusion dysautonomia and chronic pain showed a severe impact on sleep quality and disability with a consequent worsening of depressive symptom in our cohort of SSc patients.

A Nomogram to Predict Lifestyle Factors for Recurrence of Large-Vessel Ischemic Stroke

Background

Stroke is the leading cause of morbidity and mortality in China. Recurrent stroke (RS) could occur in a significant portion of patients with ischemic stroke with devastating consequence.

Methods

To investigate the association between lifestyle and the risk of RS in Chinese patients with acute large-vessel ischemic stroke (ALVIS). A total of 258 patients with ALVIS were recruited in the study (median age 63 years, 30.6% female), and followed for a median of 366 days. The primary outcomes were first RS. Cox Regression and Akaike information criterion were used to establish the best-fit nomograms.

Results

During follow-up, 38 of 258 (14.7%) participants had the primary endpoint event. After adjusting for confounding factors in multivariate Cox regression analysis, healthy lifestyles, including bland diet (hazard ratio [HR], 0.365; 95% CI, 0.138–0.965), daily fruit consumption (HR, 0.474; 95% CI, 0.238–0.945), good sleep (HR, 0.364; 95% CI, 0.180–0.739), housework: HR (0.461; 95% CI, 0.200–1.065), and HDL (HR, 0.329; 95% CI, 0.130–0.831) were associated with significantly decreased risk for RS after ALVIS, while smoking was associated with a substantial increase in RS risk (HR, 2.590; 95% CI, 1.340–5.005) and included into the nomogram. A weighted point (from 0 to 100) was given to each risk factor, and the total points could be used to predict the probability of RS for the patient.

Conclusion

The nomogram shows that healthy lifestyles (bland diet, daily fruit consumption, good sleep, cigarette cessation, and housework) were important for reducing RS in patients with ALVIS.

Associations between sleep duration, lung function, FeNO and blood eosinophils among current asthmatics (NHANES 2007-12)

Short sleep duration potentially affects the risk of developing asthma and asthmatic exacerbation. Our aim is to determine the associations between sleep duration with asthmatic phenotypes, fraction of exhaled NO (FeNO), blood eosinophils, and lung function among current asthmatics. A total of 558 individuals from the National Health and Nutrition Examination Survey during 2007-2012 were included in this study. Self-reported sleep duration was divided into three groups: short (⩽6 h), healthy (7-8 h) and long (⩾9 h). By using a multivariate generalized additive model with binomial or Poisson regression, the abovementioned associations were evaluated after adjustment for potential confounders. Our study population included 284 short sleepers, 240 healthy sleepers and 34 long sleepers. In multivariate binomial regression analysis, we found that short sleep duration was associated with increased risk of asthma with central obesity (adjusted OR = 0.58, 95%CI: 0.33-0.99, P = 0.047) compared with healthy sleep duration. Multivariate Poisson regression analyses revealed a significant increase in FeNO (adjusted OR = 1.19, 95%CI: 1.14-1.26, P < 0.01) and reduction of blood eosinophil percentage (adjusted OR = 0.86, 95%CI: 0.77-0.96, P < 0.01) in the healthy sleep duration group compared with the short sleep duration group. The individuals with healthy and long sleep duration harbored better lung function than those with short sleep duration, with the exception of FEV1/FVC. Our study suggested that short sleepers potentially increase the risk of asthma with central obesity and lung function impairment than healthy sleepers among current asthmatics. We also observed that short sleep duration is associated with a significant reduction of FeNO and increase of blood eosinophil percentage.

Association of Night Sleep Duration and Ideal Cardiovascular Health in Rural China: The Henan Rural Cohort Study

Introduction: We aimed to explore the association between night sleep duration and ideal cardiovascular health (ICH) among Chinese rural population.

Methods: In all, 35,094 participants were included from the Henan Rural Cohort study. Information on sleep was collected using the Pittsburgh Sleep Quality Index. The ICH scores were evaluated. The associations between night sleep duration and ICH were examined using both linear regression and logistic regression models.

Results: The mean night sleep duration for all participants was 7.75 ± 1.28 h. Compared with those with night sleep duration of 7 to <9 h by using linear regression model, a significant decrease in ICH scores was observed for participants with shorter [−0.077 (−0.131, −0.024)] and longer [−0.079 (−0.121, −0.036)] night sleep duration. Compared with 7 to <9 h, longer sleep duration [0.919 (0.851, 0.992)] were associated with decreased odds of ideal CVH.

Conclusions: Shorter and longer night sleep duration are negatively associated with ICH among rural population. This suggests that it may be beneficial to include night sleep duration assessment in cardiovascular risk screening.

Prevalence of insomnia in shift workers: a systematic review

Insomnia is a sleep disorder of high prevalence with somatic and psychic repercussions. The present study aimed to describe the prevalence of insomnia in shift workers, as well as the associated variables: gender, age, marital status, profession and shift work schedule. A systematic review was performed using the descriptors "insomnia" AND "shift work", in the PubMed, SciELO and LILACS databases, including studies that presented frequency of insomnia in shift workers, published between 2000 and 2020, in English or Portuguese, only in individuals over 18-years-old. Review articles, meta-analyzes, studies without socioeconomic information, articles without abstract and articles with participants who presented other comorbidities that justified presence of insomnia or pregnant women were excluded. From 480 studies identified, 5 were included in the analysis, with a total sample of 10,141 participants, of whom 4,183 were shift workers. The prevalence of insomnia in shift workers ranged from 12.8% to 76.4%, higher than estimated for general population. Moreover, a higher prevalence was observed among women and singles, and there was no significant variation with age and profession. On the other hand, a relationship between shift work schedule and onset of insomnia still seems controversial.

Biological pathways underlying the association between habitual long-sleep and elevated cardiovascular risk in adults

Cardiovascular disease is the leading cause of death in the world. In addition to non-modifiable factors such as age and sex, cardiovascular risk is also driven by behavioral, and therefore somewhat modifiable, factors such as physical activity, diet, and sleep. It is well established that sleep duration has a U-shaped association with mortality and cardiovascular disease, with recent evidence suggesting that this association is observed even while controlling for the effects of comorbid conditions. Whereas several biological mechanisms mediating the association between chronic short sleep duration and cardiovascular risk have been established, the biological mechanisms underlying the relationship between habitual long sleep (≥9 h) duration and cardiovascular risk, in the absence of other chronic diseases, are not well understood. This review will focus on summarizing the literature investigating the mechanisms underlying the association between habitual long sleep duration and cardiovascular risk. We will also propose the mechanistic pathways, distinct from the ones for short sleep, by which habitual long sleep can increase cardiovascular disease.

Associations between multiple positive health behaviors and cardiometabolic risk using 3 alternative measures of physical activity: NHANES 2005-2006

The study aimed to investigate the association between clustered cardiometabolic risk (CCMR) and health-behavior indices comprising 3 different measures of physical activity, screen time, diet and sleep in NHANES 2005-2006. CCMR was calculated by standardizing and summarizing measures of blood pressure, fasting glucose, triglycerides, insulin, high-density lipoprotein and waist circumference to create a z score. Three health behavior indices were constructed with a single point allocated to each of the following lower risk behaviors: muscle strengthening activity, healthy eating score, sleep disorder/disruption, sleep duration, screen time and physical activity (self-reported moderate-to-vigorous physical activity [MVPA] (Index Score-SR), accelerometer-measured MVPA (Index Score-MVPA) or accelerometer-measured steps Index Score-Steps). Linear regression models explored associations between index scores and CCMR. In the sample (n = 1537, 52% male, aged 45.5 [SE: 0.9] years), reporting 0-5 vs. 6 health behaviors using Index Score-SR and Index Score-MVPA, and 0-4 vs. 6 health behaviors using Index Score-Steps, were associated with a significantly higher CCMR. The beta (β [95% CI]) for zero vs. 6 behaviors were Index Score-SR (2.86 [2.02, 3.69], Index Score-MVPA (2.41 [1.49, 3.33] and Index Score-Steps (2.41 [1.68, 3.15]). Irrespective of the measure of physical activity, engaging in fewer positive health behaviors was associated with greater CCMR. Novelty: Physical activity, screen time, diet and sleep may exert synergistic/cumulative effects on clustered cardiometabolic risk. A greater number of positive health behaviors was associated with a lower clustered cardiometabolic risk factor score. The reduction in cardiometabolic risk was similar irrespective of which physical activity measure was used.

A Review of Sleep Architecture and Sleep Changes During Pregnancy

Importance

Poor sleep is widely recognized as a common complaint in pregnancy, and yet there are incomplete data on the exact nature of these complaints, what their implications for fetal and maternal health are, and how to best recognize and address these significant health issues.

Objectives

The purpose of this article is to review the current literature on the changes in objectively measured sleep parameters that occur during pregnancy, identify any possible trends, and discuss current implications for obstetric outcomes and treatments.

Evidence Acquisition

PubMed NCBI and Google Scholars database were searched for a variety of sleep-related terms, and articles were selected based on relevance to the topic and method of sleep pattern monitoring.

Results

Poor sleep is ubiquitous during pregnancy, and the relatively few studies evaluating the issue using objective polysomnography have small sample sizes. However, data suggests sleep architecture changes begin as early as the first trimester, and there is evidence that primigravid sleep structure never returns to prepregnancy levels after birth. In addition, cesarean delivery frequency, early labor, labor length, depression, gestational hypertension, and gestational diabetes all appear to be influenced by sleep changes. Current treatments are based on nonpregnant populations and may not be appropriate for the gravid patient.

Conclusions and Relevance

Disordered sleep is a more widespread and serious issue than most women are aware, and there are numerous obstetric and general health implications to cause clinician concern. More research is needed on both electroencephalography architecture changes and treatment options.

The effectiveness of non-pharmacologic treatments compared to pharmacologic treatments in veterans with sleep disturbances: a systematic review protocol

OBJECTIVE

The objective is to determine the effectiveness of non-pharmacologic treatments compared to pharmacologic treatments in veterans with sleep disturbances.

INTRODUCTION

Sleep disturbances in veterans are a common occurrence. If left untreated, these individuals are susceptible not only to accidents and injuries but long-term psychiatric and/or cardiovascular complications.

INCLUSION CRITERIA

This review will consider studies of veterans, aged 18 and over, with a diagnosis of sleep disturbances. This study will exclude patients with psychotic disorders, obstructive sleep apnea, or other medical illnesses causing disrupted sleep.

METHODS

This review will use the JBI methodology for evidence of effectiveness. The search will be limited to studies published in English after 1970. The databases to be searched include MEDLINE (PubMed), CINAHL (EBSCO), Embase (Elsevier), Scopus (Elsevier), and PsycINFO (EBSCO). The trial registers to be searched include US National Library of Medicine (ClinicalTrials.gov) and Cochrane Library. The search for unpublished studies will include ProQuest Dissertations and Theses, MedNar, and WorldWideScience. Eligible studies will undergo critical appraisal and data extraction by two independent reviewers using standardized critical appraisal instruments and a data extraction tool from JBI. Studies will be pooled in statistical meta-analysis when possible. When statistical pooling is not possible, the findings will be presented in narrative form with tables and figures.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO (CRD42019140804).

Sleep Tracking of a Commercially Available Smart Ring and Smartwatch Against Medical-Grade Actigraphy in Everyday Settings: Instrument Validation Study

BACKGROUND

Assessment of sleep quality is essential to address poor sleep quality and understand changes. Owing to the advances in the Internet of Things and wearable technologies, sleep monitoring under free-living conditions has become feasible and practicable. Smart rings and smartwatches can be employed to perform mid- or long-term home-based sleep monitoring. However, the validity of such wearables should be investigated in terms of sleep parameters. Sleep validation studies are mostly limited to short-term laboratory tests; there is a need for a study to assess the sleep attributes of wearables in everyday settings, where users engage in their daily routines.

OBJECTIVE

This study aims to evaluate the sleep parameters of the Oura ring along with the Samsung Gear Sport watch in comparison with a medically approved actigraphy device in a midterm everyday setting, where users engage in their daily routines.

METHODS

We conducted home-based sleep monitoring in which the sleep parameters of 45 healthy individuals (23 women and 22 men) were tracked for 7 days. Total sleep time (TST), sleep efficiency (SE), and wake after sleep onset (WASO) of the ring and watch were assessed using paired t tests, Bland-Altman plots, and Pearson correlation. The parameters were also investigated considering the gender of the participants as a dependent variable.

RESULTS

We found significant correlations between the ring's and actigraphy's TST (r=0.86; P<.001), WASO (r=0.41; P<.001), and SE (r=0.47; P<.001). Comparing the watch with actigraphy showed a significant correlation in TST (r=0.59; P<.001). The mean differences in TST, WASO, and SE of the ring and actigraphy were within satisfactory ranges, although there were significant differences between the parameters (P<.001); TST and SE mean differences were also within satisfactory ranges for the watch, and the WASO was slightly higher than the range (31.27, SD 35.15). However, the mean differences of the parameters between the watch and actigraphy were considerably higher than those of the ring. The watch also showed a significant difference in TST (P<.001) between female and male groups.

CONCLUSIONS

In a sample population of healthy adults, the sleep parameters of both the Oura ring and Samsung watch have acceptable mean differences and indicate significant correlations with actigraphy, but the ring outperforms the watch in terms of the nonstaging sleep parameters.

Sleep deprivation and endothelial function: reconciling seminal evidence with recent perspectives

Sleep is critical for the maintenance of physiological homeostasis and, as such, inadequate sleep beckons a myriad of pathologies. Sleep deprivation is a growing health concern in contemporary society since short sleep durations are associated with increased cardiovascular disease risk and atherosclerotic plaque development. Vascular endothelial dysfunction is an antecedent to atherosclerosis and cardiovascular disease. Herein, we review seminal literature indicating that short sleep durations attenuate endothelial function and explore more recent evidence indicating that sleep deprivation perturbs autonomic balance and the circadian rhythmicity of peripheral vascular clock components. We further examine literature that indicates a mechanistic link between short sleep duration and endothelial dysfunction and subsequent morbidity. Understanding the mechanisms that regulate endothelial function in the context of sleep deprivation facilitates the development and optimization of interventions, such as exercise, that mitigate the ramifications of inadequate sleep on vascular function and cardiovascular health.Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/sleep-deprivation-and-endothelial-function/.

Weekend catch-up sleep is associated with reduced metabolic derangements in Korean adults

BACKGROUND

Deficits in sleep are associated with metabolic derangements, but the effect of sleep supplementation on metabolic derangements remains to be elucidated. This study aimed to investigate whether weekend catch-up sleep is associated with metabolic derangements in Korean adults.

METHODS

A total of 10,749 individuals over 40 years old were identified from the 2016-2017 Korea National Health and Nutrition Examination Survey. Data on demographics, health behaviors, self-reported sleep duration, and physician-diagnosed metabolic diseases were used in this analysis. The odds ratio for each metabolic derangement was determined via stepwise multivariable logistic regression models.

RESULTS

Short weekday sleep and insufficient weekend catch-up sleep were independently associated with an increased risk for all metabolic derangements, except hypertension. Individuals who did not make up sleep on the weekend were more likely to be obese and have type 2 diabetes or hypercholesterolemia.

Brain aging and garbage cleaning : Modelling the role of sleep, glymphatic system, and microglia senescence in the propagation of inflammaging

Brain aging is a complex process involving many functions of our body and described by the interplay of a sleep pattern and changes in the metabolic waste concentration regulated by the microglial function and the glymphatic system. We review the existing modelling approaches to this topic and derive a novel mathematical model to describe the crosstalk between these components within the conceptual framework of inflammaging. Analysis of the model gives insight into the dynamics of garbage concentration and linked microglial senescence process resulting from a normal or disrupted sleep pattern, hence, explaining an underlying mechanism behind healthy or unhealthy brain aging. The model incorporates accumulation and elimination of garbage, induction of glial activation by garbage, and glial senescence by over-activation, as well as the production of pro-inflammatory molecules by their senescence-associated secretory phenotype (SASP). Assuming that insufficient sleep leads to the increase of garbage concentration and promotes senescence, the model predicts that if the accumulation of senescent glia overcomes an inflammaging threshold, further progression of senescence becomes unstoppable even if a normal sleep pattern is restored. Inverting this process by "rejuvenating the brain" is only possible via a reset of concentration of senescent glia below this threshold. Our model approach enables analysis of space-time dynamics of senescence, and in this way, we show that heterogeneous patterns of inflammation will accelerate the propagation of senescence profile through a network, confirming a negative effect of heterogeneity.

Association between short sleep duration and metabolic syndrome in Chinese children and adolescents

BACKGROUND

The relationship between short sleep duration and metabolic syndrome (MetS) in children and adolescents has been inconsistent. This study aimed to examine the association between short sleep duration and MetS in Chinese children and adolescents.

METHODS

Data were from a cross-sectional survey conducted in Jinan, China between September 2013 and November 2014. A total of 1008 children and adolescents aged 6-17 years were included. Sleep duration was self-reported by participants and categorized as normal or short (<9 h in children aged 6-12 years or <8 h in adolescents aged 13-17 years) according to the recommendations of the American Academy of Sleep Medicine. MetS was defined based on the modified criteria of the National Cholesterol Education Program Adult Treatment Panel III.

RESULTS

After adjusted for sex, age, parental education levels, and midpoint of sleep, compared with normal sleep duration, short sleep duration was associated with increased odds of MetS (odds ratio [OR]: 1.79, 95% confidence interval [CI]: 1.09-2.95) and abdominal obesity (OR: 1.60, 95% CI: 1.14-2.25). In the subgroups stratified by age and sex, compared with normal sleep duration, short sleep duration was associated with increased odds of abdominal obesity (OR: 2.34, 95% CI: 1.07-5.13) in girls aged 6-12 years; short sleep duration was associated with increased odds of MetS (OR: 2.49, 95% CI: 1.06-5.84), abdominal obesity (OR: 2.30, 95% CI: 1.10-4.82), and high TG (OR: 2.63, 95% CI: 1.11-6.21) in boys aged 13-17 years.

CONCLUSIONS

Short sleep duration associated with higher odds for MetS in Chinese children and adolescents. Interventions to improve sleep duration could help prevent and control MetS among children and adolescents.

Understanding the pathophysiological mechanisms of cardiometabolic complications in obstructive sleep apnoea: towards personalised treatment approaches

In January 2019, a European Respiratory Society research seminar entitled "Targeting the detrimental effects of sleep disturbances and disorders" was held in Dublin, Ireland. It provided the opportunity to critically review the current evidence of pathophysiological responses of sleep disturbances, such as sleep deprivation, sleep fragmentation or circadian misalignment and of abnormalities in physiological gases such as oxygen and carbon dioxide, which occur frequently in respiratory conditions during sleep. A specific emphasis of the seminar was placed on the evaluation of the current state of knowledge of the pathophysiology of cardiovascular and metabolic diseases in obstructive sleep apnoea (OSA). Identification of the detailed mechanisms of these processes is of major importance to the field and this seminar offered an ideal platform to exchange knowledge, and to discuss pitfalls of current models and the design of future collaborative studies. In addition, we debated the limitations of current treatment strategies for cardiometabolic complications in OSA and discussed potentially valuable alternative approaches.

Auricular Acupressure in Patients with Hypertension and Insomnia: A Systematic Review and Meta-Analysis

Objective

The efficacy of auricular acupressure in patients with hypertension and insomnia is controversial. This systematic review aims to explore the effectiveness of auricular acupressure in reducing blood pressure and improving sleep in this population.

Methods

We conducted an extensive database search in Cochrane Central Register of Controlled Trials, PubMed, Ovid LWW, Web of Science, Chinese Biomedical Literature Database, China Knowledge Resource Integrated Database, Wanfang Data, and China Science and Technology Journal Database on randomized controlled trials published from inception to November 2019 that compared auricular acupressure with a control or comparison group on blood pressure control and sleep improvement. Two reviewers independently conducted data screening and extraction. Study quality was evaluated using the Cochrane Handbook for Systematic Reviews of Interventions. Meta-analyses were performed on blood pressure, Pittsburgh Sleep Quality Index (PSQI), the efficacy rate of diagnostic and therapeutic criteria for traditional Chinese medicine syndromes (DTCTCMS), and the efficacy rate of guidelines for traditional Chinese medicine (new drug) clinical research (GTCMCR) by Revman 5.3.0.

Results

A total of 18 randomized controlled trials with 1685 patients were identified. Compared with a control or comparison group, pooled meta-analyses showed that auricular acupressure significantly improved systolic blood pressure (MD = −15.05, 95% CI (−18.49, −11.61), P < 0.00001), diastolic blood pressure (MD = −8.41, 95% CI (−11.33, −5.48), P < 0.00001), PSQI (MD = −2.37, 95% CI (−4.64, −0.10), P=0.04), the efficacy rate of DTCTCMS (RR = 1.63, 95% CI (1.16, 2.28), P=0.004), and the efficacy rate of GTCMCR (RR = 1.25, 95% CI (1.12, 1.38)).

Conclusions

The results demonstrated a favorable effect of auricular acupressure to reduce blood pressure and improve sleep in patients with hypertension and insomnia. Further studies to better understand the acupoints and intervention times of auricular acupressure are warranted.

Sleep quantity and quality and cardiometabolic risk factors in Indigenous Australians

Poor sleep is associated with increased risk of cardiovascular disease (CVD). Indigenous Australians have 1.3 times higher risk of CVD compared to non-indigenous Australians. However, there are limited data describing sleep problems and cardiometabolic risk in this population. This study aimed to investigate sleep quantity and quality in indigenous Australians and assess its association with cardiometabolic risk. Two hundred and forty-five indigenous Australians aged > 18 years were recruited via convenience sampling from communities in the Northern Territory and Queensland. Sleep quantity and quality was assessed subjectively with questionnaires including the Epworth Sleepiness Scale. In a sub-population (n = 46), objective sleep assessment was performed over three nights of actigraphy. Cardiometabolic risk measures included glycated haemoglobin, lipids, anthropometric measurements and sitting blood pressure. Sleep duration measured subjectively and objectively averaged 7.5 ± 2.0 hr/night; however, over one-third of participants (self-report 35%; actigraphy 39%) obtained < 7 hr/night. Overall, more than a third of participants experienced poor-quality sleep, with 27% reporting severe daytime sleepiness (ESS score > 10) and a high number of objectively measured awakenings/night (6 ± 4). Short sleep duration (<6 hr/night) measured both subjectively and objectively was an independent predictor of diastolic (β = 5.37, p = .038) and systolic blood pressure (β = 14.30, p = .048). More objectively measured night-time awakenings were associated with increased glycated haemoglobin levels (β = 0.07, p = .020) and greater sleep fragmentation was associated with lower high-density lipoprotein levels (β = -0.01, p = .025). A large proportion of indigenous Australians experienced short sleep durations and had significant sleep disruption. Poor sleep quantity and quality may contribute to heightened cardiometabolic risk in this population.

Sleep Loss Can Cause Death through Accumulation of Reactive Oxygen Species in the Gut

The view that sleep is essential for survival is supported by the ubiquity of this behavior, the apparent existence of sleep-like states in the earliest animals, and the fact that severe sleep loss can be lethal. The cause of this lethality is unknown. Here we show, using flies and mice, that sleep deprivation leads to accumulation of reactive oxygen species (ROS) and consequent oxidative stress, specifically in the gut. ROS are not just correlates of sleep deprivation but drivers of death: their neutralization prevents oxidative stress and allows flies to have a normal lifespan with little to no sleep. The rescue can be achieved with oral antioxidant compounds or with gut-targeted transgenic expression of antioxidant enzymes. We conclude that death upon severe sleep restriction can be caused by oxidative stress, that the gut is central in this process, and that survival without sleep is possible when ROS accumulation is prevented. VIDEO ABSTRACT.

Sleep debt: the impact of weekday sleep deprivation on cardiovascular health in older women

STUDY OBJECTIVES

Short sleep duration is associated with increased cardiovascular disease (CVD) risk. However, it is uncertain whether sleep debt, a measure of sleep deficiency during the week compared to the weekend, confers increased cardiovascular risk. Because sleep disturbances increase with age particularly in women, we examined the relationship between sleep debt and ideal cardiovascular health (ICH) in older women.

METHODS

Sleep debt is defined as the difference between self-reported total weekday and weekend sleep hours of at least 2 hours among women without apparent CVD and cancer participating in the Women's Health Stress Study follow-up cohort of female health professionals (N = 22 082). The ICH consisted of seven health factors and behaviors as defined by the American Heart Association Strategic 2020 goals including body mass index, smoking, physical activity, diet, blood pressure, total cholesterol, and glucose.

RESULTS

Mean age was 72.1 ± 6.0 years. Compared to women with no sleep debt, women with sleep debt were more likely to be obese and have hypertension (pall < .05). Linear regression models adjusted for age and race/ethnicity revealed that sleep debt was significantly associated with poorer ICH (B = -0.13 [95% CI = -0.18 to -0.08]). The relationship was attenuated but remained significant after adjustment for education, income, depression/anxiety, cumulative stress, and snoring.

CONCLUSION

Sleep debt was associated with poorer ICH, despite taking into account socioeconomic status and psychosocial factors. These results suggest that weekly sleep duration variation, possibly leading to circadian misalignment, may be associated with cardiovascular risk in older women.

Association between sleep duration and asthma in different weight statuses (CHNS 2009-2015)

PURPOSE

Inadequate sleep duration affects asthma and weight. The associations among sleep duration, asthma, and different weight statuses in the Chinese population need to be further determined.

METHODS

The study included 32,776 Chinese adults from the China Health and Nutrition Survey during 2009-2015. Self-reported sleep duration was classified into three groups: ≤ 6 h (short), 7 to 8 h (optimal), and ≥ 9 h (long). Age, sex, smoking, drinking alcohol, and residence location were adjusted as potential confounding factors in a generalized estimating equations model.

RESULTS

The prevalence of asthma in the Chinese population was approximately 1.17% (383/32,776). Asthmatics were associated with shorter sleep duration and higher indices of central obesity (mean waist circumference, waist to height ratio, and conicity index) than the population without asthma. After adjusting for potential confounding factors, odds ratios (ORs) indicated positive associations between sleep duration and asthma (short vs optimal, adjusted OR = 1.74, 95%CI 1.33, 2.26; and long vs optimal, adjusted OR = 1.51, 95%CI 1.18, 1.93). When stratified by weight status, the participants with central obesity showed highest prevalence of asthma among the three sleep duration groups. With the adjustment of confounding factors, underweight and obesity grouped by waist to height ratio and conicity index remained associated with higher risk of asthma among short and long sleepers than in optimal sleepers.

CONCLUSIONS

Short and long sleepers with central obesity and underweight status were associated with significantly higher prevalence of asthma than optimal sleepers in Chinese adults.

Cardiovascular diseases: a therapeutic perspective around the clock

Biological rhythms are a ubiquitous feature of life. Most bodily functions, including physiological, biochemical, and behavioral processes, are coupled by the circadian rhythm. In the cardiovascular system, circadian fluctuations regulate several functions, namely heart rate, blood pressure, cardiac contractility, and metabolism. In fact, current lifestyles impose external timing constraints that clash with our internal circadian physiology, often increasing the risk of cardiovascular disease (CVD). Still, the mechanisms of dysregulation are not fully understood because this is a growing area of research. In this review, we explore the modulatory role of the circadian rhythms on cardiovascular function and disease as well as the role of chronotherapy in the context of CVD and how such an approach could improve existing therapies and assist in the development of new ones.

BMAL1-Downregulation Aggravates Porphyromonas Gingivalis-Induced Atherosclerosis by Encouraging Oxidative Stress

RATIONALE

Atherosclerotic cardiovascular diseases are the leading cause of mortality worldwide. Atherosclerotic cardiovascular diseases are considered as chronic inflammation processes. In addition to risk factors associated with the cardiovascular system itself, pathogenic bacteria such as the periodontitis-associated Porphyromonas gingivalis (P gingivalis) are also closely correlated with the development of atherosclerosis, but the underlying mechanisms are still elusive.

OBJECTIVE

To elucidate the mechanisms of P gingivalis-accelerated atherosclerosis and explore novel therapeutic strategies of atherosclerotic cardiovascular diseases.

METHODS AND RESULTS

Bmal1-/- (brain and muscle Arnt-like protein 1) mice, ApoE-/- mice, Bmal1-/-ApoE-/- mice, conditional endothelial cell Bmal1 knockout mice (Bmal1fl/fl; Tek-Cre mice), and the corresponding jet-legged mouse model were used. Pgingivalis accelerates atherosclerosis progression by triggering arterial oxidative stress and inflammatory responses in ApoE-/- mice, accompanied by the perturbed circadian clock. Circadian clock disruption boosts P gingivalis-induced atherosclerosis progression. The mechanistic dissection shows that P gingivalis infection activates the TLRs-NF-κB signaling axis, which subsequently recruits DNMT-1 to methylate the BMAL1 promoter and thus suppresses BMAL1 transcription. The downregulation of BMAL1 releases CLOCK, which phosphorylates p65 and further enhances NF-κB signaling, elevating oxidative stress and inflammatory response in human aortic endothelial cells. Besides, the mouse model exhibits that joint administration of metronidazole and melatonin serves as an effective strategy for treating atherosclerotic cardiovascular diseases.

CONCLUSIONS

P gingivalis accelerates atherosclerosis via the NF-κB-BMAL1-NF-κB signaling loop. Melatonin and metronidazole are promising auxiliary medications toward atherosclerotic cardiovascular diseases.

Acupuncture for insomnia with short sleep duration: protocol for a randomised controlled trial

INTRODUCTION

Insomnia with short sleep duration has a more serious negative impact on patient health. The existing literature suggests that medication therapy is more effective for this phenotype of insomnia compared with cognitive-behavioural therapy. However, the potential side effects of hypnotic medications hinder their clinical application. Acupuncture has been widely used in the treatment of insomnia, but it remains unclear whether it has therapeutic efficacy for insomnia with short sleep duration. The purpose of this trial is to evaluate the efficacy and safety of acupuncture for insomnia with short sleep duration.

METHODS AND ANALYSIS

This study is designed as a randomised, single-centre, single-blinded, placebo acupuncture controlled trial involving 152 participants. Eligible patients will be divided into two groups according to the objective total sleep time: insomnia with normal sleep duration group and insomnia with short sleep duration group. Then, patients in each group will be randomly assigned to two subgroups, the treatment group (acupuncture) and the control group (placebo acupuncture), in a 1:1 ratio with 38 subjects in each subgroup. The primary outcome is the Pittsburgh Sleep Quality Index and the Insomnia Severity Index. Secondary outcomes are actigraphy, the Beck Anxiety Inventory, the Beck Depression Inventory and the Fatigue Severity Scale. All adverse effects will be assessed by the Treatment Emergent Symptom Scale. Outcomes will be evaluated at baseline, post treatment, as well as at 1-week and 1-month follow-up.

ETHICS AND DISSEMINATION

This protocol has been approved by the ethics committee of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine (no. 2019-17). Written informed consent will be obtained from all participants. The results will be disseminated through peer-reviewed journals for publications.

TRIAL REGISTRATION NUMBER

ChiCTR1900023473; Pre-results.

Multimorbidity in COPD, does sleep matter?

A good night's sleep is a prerequisite for sustainable mental and physical health. Sleep disorders, including sleep disordered breathing, insomnia and sleep related motor dysfunction (e.g., restless legs syndrome), are common in patients with chronic obstructive pulmonary disease (COPD), especially in more severe disease. COPD is commonly associated with multimorbidity, and sleep disorders as a component of this multimorbidity spectrum have a further negative impact on COPD-related comorbidities. Indeed, concomitant diseases in COPD and in obstructive sleep apnea (OSA) are similar, suggesting that the combination of COPD and OSA, the so called OSA-COPD overlap syndrome (OVS), affects patient outcomes. Potential clinically important interactions of OVS exist in cardiovascular and metabolic disease, arthritis, anxiety, depression, neurocognitive disorder and the fatigue syndrome. Correct diagnosis for recognition and treatment of sleep-related disorders in COPD is recommended. However, surprisingly limited information is available and further research and improved diagnostic tools are needed. In the absence of clear evidence, we agree with the recommendation of the Global Initiative on Chronic Obstructive Lung Disease that sleep disorders should be actively searched for and treated in patients with COPD. We believe that both aspects are important components of the holistic approach required in patients with chronic multimorbid conditions.

Long Sleep Duration is Associated with Increased High-Sensitivity C-Reactive Protein: A Nationwide Study on Chinese Population

PURPOSE

High-sensitivity C-reactive protein (hs-CRP) has been shown as an important predictor of cardiovascular risk, and sleep duration is an important factor influencing health outcomes. However, the association between hs-CRP and sleep duration among Chinese adults remained unknown and controversial. We aimed to explore the associations between sleep duration and hs-CRP levels among Chinese adults, and the differences in sex and geographical regions.

METHODS

This cross-sectional study was based on nationally representative Chinese samples from the 2009 China Health and Nutrition Survey, which employed multistage, random cluster designs. Habitual sleep duration was self-reported with short and long sleep duration defined as ≤6h and ≥9h per day, respectively. Participants were divided into 4 groups based on the categories of self-reported sleep duration (≤6h, 7h, 8h, ≥9h per day), excluding hs-CRP levels ≥10 mg/L. Subset samples were stratified by sex and geographical regions.

RESULTS

A total of 8170 Chinese adults with a mean age of 50.0±14.9 years and 4369 (53.5%) men were included. Participants sleeping eight hours had the lowest hs-CRP levels. Long sleep duration (≥9h) was significantly associated with elevated hs-CRP levels after adjusting for multiple covariates in full samples (β=0.0356; 95% CI: 0.0050-0.0663; P=0.0228), but the associations of short sleep duration (≤ 6h) were limited to the unadjusted model. Long sleep duration was associated with elevated hs-CRP levels in women (β= 0.0512; 95% CI: 0.0097-0.0927; P=0.0155) and in the northern region of China (β=0.0699; 95% CI: 0.0210-0.1187; P=0.0051), but not in men or the southern region.

CONCLUSION

Long but not short sleep duration was positively associated with elevated hs-CRP levels, independent from traditional risk factors among Chinese adults, and sex and geographical differences were observed. Our findings imply that modifications of long sleep duration might be added to behavioral therapy to reduce cardiovascular risk in Chinese adults.

The Association Between Sleep Duration, Asthma-Related Episodes/Attacks and Emergency Department Visits

BACKGROUND

Inadequate sleep duration potentially increases the risk of allergic asthma; yet, the effect of different sleep duration on asthma-related episodes/attacks and emergency department (ED) visits has remained unclear. The purpose of this study is to evaluate the association between sleep duration, asthma-related episodes/attacks and ED visits.

METHODS

This study included 1526 asthma participants from the Behavioral Risk Factor Surveillance System Questionnaire during 2013-2017. Self-reported sleep duration was classified into three groups: ≤6 h (short), 7 h to 8 h (optimal) and ≥9 h (long). Generalized additive model with binomial or Poisson regression was used to complete all statistical analyses.

RESULTS

During a 12-month period, 857 participants reported acute episodes/attacks of asthma, and 279 participants reported asthma-related ED visits. Asthmatics with ED visits harbored significantly lower mean sleep duration (6.50 h vs 7.01 h, adjusted OR=0.93, 95% CI: 0.88-0.98) than those without episodes/attacks. After adjusting the potential confounding factors, the participants with long sleep duration were associated with lower risk of asthma-related episodes/attacks (adjusted OR=0.59, 95% CI: 0.41-0.86) than those with short sleep duration. The prevalence (adjusted OR=0.67, 95% CI: 0.47-0.94) and frequency (adjusted OR=0.83, 95% CI: 0.69-0.9996) of asthma-related ED visits among short sleepers were significantly higher than that among optimal sleepers. The differences of asthma-related episodes/attacks and ED visits between long and optimal sleepers were statistically insignificant.

CONCLUSION

Our study demonstrated that asthmatics with short sleep duration were associated with highest prevalence of asthma-related episodes/attacks and ED visits among the three sleep duration groups.

Objective Short Sleep Duration is Related to the Peripheral Inflammasome Dysregulation in Patients with Chronic Insomnia

OBJECTIVE

Insomnia with objective short sleep duration (IOSSD) is associated with an increased risk of cardiovascular morbidity, diabetes, neurocognitive impairment, and mortality. Inflammation is believed to be one of the main links between IOSSD and these diseases. The role of nucleotide-binding domain and leucine-rich repeat protein-3 (NLRP3) inflammasome in inducing activation of inflammatory signaling in IOSSD is not clear. In this study, we investigated the expression of NLRP3 inflammasome in patients with IOSSD to clarify this issue.

METHODS

Thirty-six patients with insomnia and 20 age- and sex-matched healthy controls were sequentially recruited. Subjects were categorized into three groups: IOSSD (sleep duration < 6h, n=20), insomnia with objective normal sleep duration (IONSD, sleep duration ≥ 6h, n=16) and healthy controls (n=20). Objective sleep parameters were measured by overnight polysomnography. Peripheral NLRP3 inflammasome protein levels [NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspase l] and cytokines [interleukin (IL)-1β and IL-18] were assessed by Western blotting and ELISA, respectively.

RESULTS

IOSSD group showed significantly increased protein expressions of ASC and caspase-1 compared to IONSD and healthy controls and significantly increased IL-18 levels compared to healthy controls. On correlation analysis, total sleep time showed an inverse correlation with NLRP3, ASC, IL-18, and IL-1β levels. Wake after sleep onset (WASO) showed a positive correlation with NLRP3, ASC, caspase-1, and IL-1β levels. N3 sleep ratio showed a significant negative correlation with NLRP3, ASC, and IL-18 levels.

CONCLUSION

The current study demonstrated upregulation of NLRP3 inflammasome in IOSSD. Short sleep duration, decreased slow wave sleep, and sleep fragmentation may contribute to dysregulation of NLRP3 inflammasome.

Chronic inflammation in the etiology of disease across the life span

Although intermittent increases in inflammation are critical for survival during physical injury and infection, recent research has revealed that certain social, environmental and lifestyle factors can promote systemic chronic inflammation (SCI) that can, in turn, lead to several diseases that collectively represent the leading causes of disability and mortality worldwide, such as cardiovascular disease, cancer, diabetes mellitus, chronic kidney disease, non-alcoholic fatty liver disease and autoimmune and neurodegenerative disorders. In the present Perspective we describe the multi-level mechanisms underlying SCI and several risk factors that promote this health-damaging phenotype, including infections, physical inactivity, poor diet, environmental and industrial toxicants and psychological stress. Furthermore, we suggest potential strategies for advancing the early diagnosis, prevention and treatment of SCI.

Impact of Circadian Disruption on Cardiovascular Function and Disease

The circadian system, that is ubiquitous across species, generates ∼24 h rhythms in virtually all biological processes, and allows them to anticipate and adapt to the 24 h day/night cycle, thus ensuring optimal physiological function. Epidemiological studies show time-of-day variations in adverse cardiovascular (CV) events, and controlled laboratory studies demonstrate a circadian influence on key markers of CV function and risk. Furthermore, circadian misalignment, that is typically experienced by shift workers as well as by individuals who experience late eating, (social) jet lag, or circadian rhythm sleep-wake disturbances, increases CV risk factors. Therefore, understanding the mechanisms by which the circadian system regulates CV function, and which of these are affected by circadian disruption, may help to develop intervention strategies to mitigate CV risk.

Restless legs syndrome, periodic limb movements during sleep and cardiovascular risk

Multiple mechanisms may modulate an association between restless legs syndrome/Willis-Ekbom disease (RLS/WED) and cardiovascular disease (CVD), including chronic sleep deprivation, intermittent, periodic limb movements in sleep (PLMS)-related autonomic fluctuations and possible autonomic dysfunction intrinsically associated with RLS per se. The purpose of this paper is to review the existing RLS/WED literature focusing on the pathophysiologic evidence for possible associations between RLS/WED and PLMS with CVD and events (CVE). Specific intrinsic dysautonomic aspects of the disease, which may contribute to generating CVD, are separately discussed. The association between RLS/WED and both CV risk factors and CVD still remains elusive. Although several shared pathophysiological causes could explain these possible relationships, the emerging body of literature focusing on these disorders remains controversial. Not only longitudinal population-based studies and meta-analyses, but also more animal models and therapeutic interventions are needed in order to build a sufficiently robust body of evidence on this topic.

Risk of resistant hypertension associated with restless legs syndrome and periodic limb movements during sleep: a study on 673 treated hypertensive individuals

OBJECTIVE

Given the limited data available in the literature, the aim of this study was to examine the risk of resistant hypertension (RHT) associated with restless legs syndrome (RLS) and periodic limb movements during sleep (PLMS) in a large sample of treated hypertensive individuals.

METHODS

Demographic and polysomnographic (PSG) data from 673 treated hypertensive individuals recruited from the research database of the sleep laboratory of Erasme Hospital were analysed. After exclusion of the main causes of pseudo-resistance and secondary hypertension, RHT status was defined by the presence of an uncontrolled hypertension despite treatment with at least three antihypertensive agents (including a diuretic) from different classes in correct combination and at the highest tolerated doses or by the presence of controlled hypertension requiring the use of at least four antihypertensive agents. Logistic regression analyses were conducted to examine the risk of RHT associated with RLS and PLMS in treated hypertensive individuals.

RESULTS

After adjustment for major confounding factors associated with RHT, multivariate logistic regression analysis revealed that frequent RLS (≥2 episodes/week) combined with PLMS index ≥26/h [odds ratio (OR) 2.20; 95% confidence interval (CI) 1.35-3.61, p = 0.021] was a significant risk factor of RHT in treated hypertensive individuals.

CONCLUSION

In treated hypertensive individuals, frequent RLS combined with PLMS index ≥26/h is associated with higher risk of RHT which suggests that this pathology may be a secondary cause of RHT (eg, obstructive sleep apnoea syndrome and insomnia with short sleep duration) justifying the establishment of effective treatments in this particular subpopulation.