Cardiovascular effects of partial sleep deprivation in healthy volunteers

Association between late sleeping and major adverse cardiovascular events in patients with percutaneous coronary intervention

BACKGROUND

Sleeping late has been a common phenomenon and brought harmful effects to our health. The purpose of this study was to investigate the association between sleep timing and major adverse cardiovascular events (MACEs) in patients with percutaneous coronary intervention (PCI).

METHODS

Sleep onset time which was acquired by the way of sleep factors questionnaire in 426 inpatients was divided into before 22:00, 22:00 to 22:59, 23:00 to 23:59 and 24:00 and after. The median follow-up time was 35 months. The endpoints included angina pectoris (AP), new myocardial infarction (MI) or unplanned repeat revascularization, hospitalization for heart failure, cardiac death, nonfatal stroke, all-cause death and the composite endpoint of all events mentioned above. Cox proportional hazards regression was applied to analyze the relationship between sleep timing and endpoint events.

RESULTS

A total of 64 composite endpoint events (CEEs) were reported, including 36 AP, 15 new MI or unplanned repeat revascularization, 6 hospitalization for heart failure, 2 nonfatal stroke and 5 all-cause death. Compared with sleeping time at 22:00-22:59, there was a higher incidence of AP in the bedtime ≥ 24:00 group (adjusted HR: 5.089; 95% CI: 1.278-20.260; P = 0.021). In addition, bedtime ≥ 24:00 was also associated with an increased risk of CEEs in univariate Cox regression (unadjusted HR: 2.893; 95% CI: 1.452-5.767; P = 0.003). After multivariable adjustments, bedtime ≥ 24:00 increased the risk of CEEs (adjusted HR: 3.156; 95% CI: 1.164-8.557; P = 0.024).

CONCLUSION

Late sleeping increased the risk of MACEs and indicated a poor prognosis. It is imperative to instruct patients with PCI to form early bedtime habits.

Associations of actigraph sleep characteristics with blood pressure among older adults

OBJECTIVES

Many studies have examined links between sleep and blood pressure, with mixed findings, mostly using self-reported sleep data and cross-sectional designs. We examined whether actigraph-estimated sleep characteristics are associated with concurrent blood pressure or 5-year blood pressure change in a national cohort of older adults (National Social Life, Health and Aging Project), and whether these associations differ by hypertension medication use.

METHODS

Subjects were 669 older adults (62-90years), 471 with 5-year follow-up data. Sleep characteristics were duration (linear plus quadratic terms); sleep percentage; and categorical onset, midpoint, and waking times. Multivariable linear models adjusted for age, race, gender, obesity, smoking, daytime napping, and hypertension medication use. Interactions between sleep characteristics and hypertension medication were tested among the 401 subjects with consistent hypertension medication status over time.

RESULTS

We found U-shaped cross-sectional and longitudinal relationships between duration and blood pressure, with shorter and longer sleep times associated with higher blood pressure. Later onset times were cross-sectionally associated with higher systolic blood pressure, while earlier onset times were longitudinally associated with systolic blood pressure increase. Midpoint, wake time, and sleep percentage were not significantly associated with blood pressure. Significant interaction terms suggested hypertension medications attenuated associations of sleep onset and wake time with diastolic blood pressure.

CONCLUSIONS

These results with actigraph-estimated parameters confirm some, but not all, associations reported from research based on self-reported sleep data. Our findings are consistent with recommended intermediate sleep durations for cardiovascular health and suggest hypertension medication use may attenuate some associations between sleep timing and blood pressure.

Acute partial sleep restriction does not impact arterial function in young and healthy humans

Habitual short sleep durations are associated with several cardiovascular diseases. Experimental research generally supports these findings as metrics of arterial function are impaired after complete deprivation of sleep and after longer periods of partial sleep restriction. The acute influence of a single instance of partial sleep restriction (PSR), however, has not been defined. We evaluated arterial structure and function among 32 university-aged participants on two occasions: once after normal habitual sleep (NS), and again the morning after an acute partial sleep restriction (PSR) intervention involving only 3 h of sleep for a single night. Endothelial function was measured using ultrasonography at the brachial artery via flow-mediated dilatation (FMD), and a ramp peak oxygen uptake test was used to evaluate cardiorespiratory fitness. Blood samples were collected from a subset of participants to investigate the influence of circulatory factors on cellular mechanisms implicated in endothelial function. Sleep duration was lower after a night of PSR compared to NS (P < 0.001); however, there were no appreciable differences in any haemodynamic outcome between conditions. FMD was not different between NS and PSR (NS: 6.5 ± 2.9%; PSR: 6.3 ± 2.9%; P = 0.668), and cardiorespiratory fitness did not moderate the haemodynamic response to PSR (all P > 0.05). Ex vivo cell culture results aligned with in vivo data, showing that acute PSR does not alter intracellular processes involved in endothelial function. No differences in arterial structure or function were observed between NS and acute PSR in healthy and young participants, and cardiorespiratory fitness does not modulate the arterial response to acute sleep restriction.

Sleep fragmentation exacerbates myocardial ischemia‒reperfusion injury by promoting copper overload in cardiomyocytes

Sleep disorders increase the risk and mortality of heart disease, but the brain-heart interaction has not yet been fully elucidated. Cuproptosis is a copper-dependent type of cell death activated by the excessive accumulation of intracellular copper. Here, we showed that 16 weeks of sleep fragmentation (SF) resulted in elevated copper levels in the male mouse heart and exacerbated myocardial ischemia-reperfusion injury with increased myocardial cuproptosis and apoptosis. Mechanistically, we found that SF promotes sympathetic overactivity, increases the germination of myocardial sympathetic nerve terminals, and increases the level of norepinephrine in cardiac tissue, thereby inhibits VPS35 expression and leads to impaired ATP7A related copper transport and copper overload in cardiomyocytes. Copper overload further leads to exacerbated cuproptosis and apoptosis, and these effects can be rescued by excision of the sympathetic nerve or administration of copper chelating agent. Our study elucidates one of the molecular mechanisms by which sleep disorders aggravate myocardial injury and suggests possible targets for intervention.

Sleep deprivation reduces the baroreflex sensitivity through elevated angiotensin (Ang) II subtype 1 receptor expression in the nucleus tractus solitarii

Introduction

Sleep insufficiency has been linked to an increased risk of high blood pressure and cardiovascular diseases. Emerging studies have demonstrated that impaired baroreflex sensitivity (BRS) is involved in the adverse cardiovascular effects caused by sleep deprivation, however, the underlying mechanisms remain unknown. Therefore, the present study aims to clarify the role of abnormal renin-angiotensin system in the nucleus tractus solitarii (NTS) in impaired BRS induced by sleep deprivation.

Methods

Rats were randomly divided into two groups: normal sleep (Ctrl) and chronic sleep deprivation (CSD) group. Rats were sleep deprived by an automated sleep deprivation system. The blood pressure, heart rate, BRS, the number of c-Fos positive cells and the expression of angiotensin (Ang) II subtype 1 receptors (AT1R) in the NTS of rats were assessed.

Results

Compared to Ctrl group, CSD group exhibited a higher blood pressure, heart rate, and reduced BRS. Moreover, the number of c-Fos positive cells and local field potential in the NTS in CSD group were increased compared with the Ctrl group. It was shown that the expression of the AT1R and the content of Ang II and the ratio of Ang II to Ang-(1-7) were increased in the NTS of rats in CSD group compared to Ctrl group. In addition, microinjection of losartan into the NTS significantly improved the impaired BRS caused by sleep deprivation.

Discussion

In conclusion, these data suggest that the elevated AT1R expression in the NTS mediates the reduced BRS induced by chronic sleep deprivation.

Assessing Risk of Health Outcomes From Brain Activity in Sleep: A Retrospective Cohort Study

Background and Objectives

Patterns of electrical activity in the brain (EEG) during sleep are sensitive to various health conditions even at subclinical stages. The objective of this study was to estimate sleep EEG-predicted incidence of future neurologic, cardiovascular, psychiatric, and mortality outcomes.

Methods

This is a retrospective cohort study with 2 data sets. The Massachusetts General Hospital (MGH) sleep data set is a clinic-based cohort, used for model development. The Sleep Heart Health Study (SHHS) is a community-based cohort, used as the external validation cohort. Exposure is good, average, or poor sleep defined by quartiles of sleep EEG-predicted risk. The outcomes include ischemic stroke, intracranial hemorrhage, mild cognitive impairment, dementia, atrial fibrillation, myocardial infarction, type 2 diabetes, hypertension, bipolar disorder, depression, and mortality. Diagnoses were based on diagnosis codes, brain imaging reports, medications, cognitive scores, and hospital records. We used the Cox survival model with death as the competing risk.

Results

There were 8673 participants from MGH and 5650 from SHHS. For all outcomes, the model-predicted 10-year risk was within the 95% confidence interval of the ground truth, indicating good prediction performance. When comparing participants with poor, average, and good sleep, except for atrial fibrillation, all other 10-year risk ratios were significant. The model-predicted 10-year risk ratio closely matched the observed event rate in the external validation cohort.

Discussion

The incidence of health outcomes can be predicted by brain activity during sleep. The findings strengthen the concept of sleep as an accessible biological window into unfavorable brain and general health outcomes.

Feasibility, Acceptability, and Preliminary Effectiveness of a Sleep Intervention in Adults at Risk for Metabolic Syndrome With Short Sleep Duration

BACKGROUND

The prevalence of short sleep duration is rising and is linked to chronic comorbidities, such as metabolic syndrome (MetS). Sleep extension interventions in adults with MetS comorbidities and short sleep duration are limited and vary widely in terms of approach and duration.

OBJECTIVES

This pilot study aimed to test the feasibility and acceptability of a personalized 12-week systematic sleep time extension intervention on post-intervention sleep outcomes in middle-aged adults at risk for MetS with actigraphy-estimated short sleep duration.

METHODS

A single-arm, 12-week, 12-session systematic sleep time extension intervention was delivered weekly via videoconferencing. Feasibility and acceptability were assessed using retention rates and mean sleep diary completions. Sleep was estimated for 14 consecutive days prior to and immediately following the 12-week intervention using wrist actigraphy. Daytime sleepiness was assessed using the Epworth Sleepiness Scale. Paired sample t -tests modeled changes in study outcomes.

RESULTS

Study participants ( N = 41) had a mean age of 52 years and were mostly female and White; 86% attended >80% of sessions, and mean sleep diary completion was 6.7 diaries/week. Significant improvements in sleep from pre- to post-intervention included increased total sleep time, earlier sleep onsets, more regular sleep onsets, a higher sleep regularity index, and reduced daytime sleepiness. Extending sleep, as well as improving sleep timing and regularity in middle-aged adults with actigraphy-estimated short sleep duration and at risk for MetS, is feasible and acceptable.

DISCUSSION

Behavioral sleep characteristics may be modifiable and present a novel behavioral paradigm for mitigating MetS risk. This pilot study provides a proof of concept for the feasibility, acceptability, and preliminary effectiveness of a systematic sleep time extension for middle-aged adults at risk for MetS with actigraphy-estimated short sleep duration.

Association of sleep quality and mitochondrial DNA copy number in healthy middle-aged adults

OBJECTIVES

Mitochondria contribute to various compromised health, yet the association between sleep and mitochondria remains unclear. This study investigated the association between sleep quality and mitochondrial function in healthy middle-aged adults in the Republic of Korea.

METHOD

This cross-sectional study recruited 238 middle-aged adults using convenience sampling. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Mitochondrial function, represented by mitochondrial DNA copy number (mtDNAcn), was measured using real-time quantitative polymerase chain reaction on peripheral blood leukocytes. Multivariate linear regression analyses were performed to determine the association between sleep quality and mtDNAcn.

RESULTS

Sleep quality was negatively associated with mtDNAcn (r = -.15, p = .025); the poor sleep quality group had a notably lower mtDNAcn compared to the good sleep quality group (t = 2.40, p = .017). Among the PSQI components, sleep latency was significantly associated with reduced mtDNAcn (r = -.18, p = .005). Univariate regression analysis revealed that mtDNAcn was significantly associated with education level (β = 0.15, p = .017), shift work (β = -0.17, p = .010), global PSQI score (β = -0.15, p = .025), and sleep latency (β = -0.18, p = .005). After adjusting for educational level and shift work in the final model, longer sleep latency was independently associated with reduced mtDNAcn (β = -.16, p = .011).

CONCLUSIONS

Poor sleep quality is associated with reduced mtDNAcn, suggesting a potential biological mechanism whereby poor sleep quality, specifically long sleep latency, accelerates cellular aging and impairs health through mitochondrial dysfunction. These findings enhance our understanding of the health effects of sleep quality and highlight the importance of screening and intervention strategies for mitochondrial dysfunction.

Sleep and cardiometabolic risk. Narrative revision

OBJECTIVES

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Integrating physiological monitoring systems in military aviation: a brief narrative review of its importance, opportunities, and risks

Military pilots risk their lives during training and operations. Advancements in aerospace engineering, flight profiles, and mission demands may require the pilot to test the safe limits of their physiology. Monitoring pilot physiology (e.g. heart rate, oximetry, and respiration) inflight is in consideration by several nations to inform pilots of reduced performance capacity and guide future developments in aircraft and life-support system design. Numerous challenges, however, prevent the immediate operationalisation of physiological monitoring sensors, particularly their unreliability in the aerospace environment and incompatibility with pilot clothing and protective equipment. Human performance and behaviour are also highly variable and measuring these in controlled laboratory settings do not mirror the real-world conditions pilots must endure. Misleading or erroneous predictive models are unacceptable as these could compromise mission success and lose operator trust. This narrative review provides an overview of considerations for integrating physiological monitoring systems within the military aviation environment.Practitioner summary: Advancements in military technology can conflictingly enhance and compromise pilot safety and performance. We summarise some of the opportunities, limitations, and risks of integrating physiological monitoring systems within military aviation. Our intent is to catalyse further research and technological development.Abbreviations: AGS: anti-gravity suit; AGSM: anti-gravity straining manoeuvre; A-LOC: almost loss of consciousness; CBF: cerebral blood flow; ECG: electrocardiogram; EEG: electroencephalogram; fNIRS: functional near-infrared spectroscopy; G-forces: gravitational forces; G-LOC: gravity-induced loss of consciousness; HR: heart rate; HRV: heart rate variability; LSS: life-support system; NATO: North Atlantic Treaty Organisation; PE: Physiological Episode; PCO2: partial pressure of carbon dioxide; PO2: partial pressure of oxygen; OBOGS: on board oxygen generating systems; SpO2: peripheral blood haemoglobin-oxygen saturation; STANAG: North Atlantic Treaty Organisation Standardisation Agreement; UPE: Unexplained Physiological Episode; WBV: whole body vibration.

Heart rate and heart rate variability following sleep deprivation in retired night shift workers and retired day workers

Shift workers experience poor sleep and dysregulated cardiac autonomic function during sleep. However, it is unknown if this dysregulation persists into retirement, potentially accelerating the age-associated risk for adverse cardiovascular outcomes. Using sleep deprivation as a physiological challenge to cardiovascular autonomic function, we compared heart rate (HR) and high-frequency heart rate variability (HF-HRV) during baseline and recovery sleep following sleep deprivation between retired night shift and day workers. Participants were retired night shift (N = 33) and day workers (N = 37) equated on age (mean [standard deviation] = 68.0 [5.6] years), sex (47% female), race/ethnicity (86% White), and body mass index. Participants completed a 60-h lab protocol including one night of baseline polysomnography-monitored sleep, followed by 36 h of sleep deprivation and one night of recovery sleep. Continuously recorded HR was used to calculate HF-HRV. Linear mixed models compared HR and HF-HRV during non-rapid eye movement (NREM) and REM sleep between groups during baseline and recovery nights. Groups did not differ on HR or HF-HRV during NREM or REM sleep (ps > .05) and did not show differential responses to sleep deprivation. In the full sample, HR increased and HF-HRV decreased from baseline to recovery during NREM (ps < .05) and REM (ps < .01). Both groups exhibited cardiovascular autonomic changes during recovery sleep following 36 h of sleep deprivation. Sleep deprivation appears to induce cardiovascular autonomic changes that persist into recovery sleep in older adults, regardless of shift work history.

Noise Exposure and Cardiovascular Health

Noise is considered an environmental stressor adversely affecting well-being and quality of life, inter-individual communications, and attention and cognitive function and inducing emotional responses, corresponding to noise annoyance. In addition, noise exposure is associated with nonauditory effects including worsening mental health, cognitive impairments, and adverse birth outcomes, sleep disorders, and increased annoyance. An accumulating body of evidence has indicated that traffic noise is also associated with CVD, through multiple pathways. It has been shown that psychological stress and mental health disorders such as depression and anxiety have a negative impact on the development of cardiovascular diseases and outcomes. Likewise, reduced sleep quality and/or duration has been reported to increase sympathetic nervous system activity, which can predispose to conditions like hypertension and diabetes mellitus, known risk factors for CVD. Finally, there seems to be a disruption in the hypothalamic-pituitary-axis secondary to noise pollution that also results in an increased risk of CVD. The World Health Organization has estimated that the number of DALYs (disability-adjusted life-years) lost resulting from environmental noise in Western Europe ranges from 1 to 1.6 million, making noise the second major contributor to the burden of disease in Europe, only after air pollution. Thus, we sought to explore the relationship between noise pollution and risk of CVD.

Recovery Sleep After Sleep Restriction Is Insufficient to Return Elevated Daytime Heart Rate and Systolic Blood Pressure to Baseline Levels

OBJECTIVE

Sleep restriction alters daytime cardiac activity, including elevating heart rate (HR) and blood pressure (BP). There is minimal research on the cumulative effects of sleep loss and the response after subsequent recovery sleep on HR and BP. This study examined patterns of HR and BP across baseline, sleep restriction, and recovery conditions using multiple daytime cardiac measurements.

METHODS

Participants (15 healthy men, mean [standard deviation] = 22.3 [2.8] years) completed an 11-day inpatient protocol with three nights of 10 hours/night baseline sleep opportunity, five sleep restriction nights (5-hour/night sleep opportunity), and two recovery nights (10-hour/night sleep opportunity). Resting HR and BP were measured every 2 hours during wake. Multilevel models with random effects for individuals examined daytime HR and BP across study conditions and days into the study.

RESULTS

Mean daytime HR was 1.2 (0.5) beats/min lower during sleep restriction compared with baseline ( p < .001). During recovery, HR was 5.5 (1.0) beats/min higher ( p < .001), and systolic BP (SBP) was 2.9 (1.1) mm Hg higher ( p = .009). When accounting for days into the study (irrespective of condition) and measurement timing across the day, HR increased by 7.6 beats/min and SBP increased by 3.4 mm Hg across the study period ( p < .001).

CONCLUSIONS

Our findings suggest that daytime HR and SBP increase after successive nights of sleep restriction, even after accounting for measurement time of day. HR and SBP did not recover to baseline levels after two recovery nights of sleep, suggesting that longer recovery sleep may be necessary to recover from multiple, consecutive nights of moderate sleep restriction.

Peripheral and central macrophages in obesity

Obesity is associated with chronic, low-grade inflammation. Excessive nutrient intake causes adipose tissue expansion, which may in turn cause cellular stress that triggers infiltration of pro-inflammatory immune cells from the circulation as well as activation of cells that are residing in the adipose tissue. In particular, the adipose tissue macrophages (ATMs) are important in the pathogenesis of obesity. A pro-inflammatory activation is also found in other organs which are important for energy metabolism, such as the liver, muscle and the pancreas, which may stimulate the development of obesity-related co-morbidities, including insulin resistance, type 2 diabetes (T2D), cardiovascular disease (CVD) and non-alcoholic fatty liver disease (NAFLD). Interestingly, it is now clear that obesity-induced pro-inflammatory signaling also occurs in the central nervous system (CNS), and that pro-inflammatory activation of immune cells in the brain may be involved in appetite dysregulation and metabolic disturbances in obesity. More recently, it has become evident that microglia, the resident macrophages of the CNS that drive neuroinflammation, may also be activated in obesity and can be relevant for regulation of hypothalamic feeding circuits. In this review, we focus on the action of peripheral and central macrophages and their potential roles in metabolic disease, and how macrophages interact with other immune cells to promote inflammation during obesity.

Sleep Deprivation and Heart Rate Variability in Healthy Volunteers: Effects of REM and SWS Sleep Deprivation

Objective

Using PSG-guided acute selective REM/SWS sleep deprivation in volunteers, this study examined the effects of sleep deprivation on the cardiovascular and autonomic nervous systems, as well as the relationship between cardiac neuromodulation homeostasis and cardiovascular disease.

Methods

An experiment was conducted using 30 healthy volunteers (male : female = 1 : 1, aged 26.33 ± 4.5 years) divided into groups for sleep deprivation of SWS and REM sleep, and then, each group was crossed over for normal sleep (2 days) and repeated sleep deprivation (1 day, 3 times). During the study period, PSG and ELECTRO ECG monitoring were conducted, and five-minute frequency domain parameters and blood pressure values were measured before and after sleep deprivation.

Results

Changes in VLF, LFnu, LF/HF, HF, and HFnu after SWS sleep deprivation were statistically significant (P < 0.05), but not LF (P = 0.063). Changes in VLF, LF, HF, LF/HF, LFnu, and HFnu after REM sleep deprivation were not statistically significant (P > 0.05).

Conclusions

An increase in sympathetic nerve activity results from sleep deprivation and sudden awakening from SWS sleep is associated with a greater risk of cardiovascular disease.

Associations of bedroom PM2.5, CO2, temperature, humidity, and noise with sleep: An observational actigraphy study

OBJECTIVE

Climate change and urbanization increasingly cause extreme conditions hazardous to health. The bedroom environment plays a key role for high-quality sleep. Studies objectively assessing multiple descriptors of the bedroom environment as well as sleep are scarce.

METHODS

Particulate matter with a particle size <2.5 µm (PM2.5), temperature, humidity, carbon dioxide (CO2), barometric pressure, and noise levels were continuously measured for 14 consecutive days in the bedroom of 62 participants (62.9% female, mean ± SD age: 47.7 ± 13.2 years) who wore a wrist actigraph and completed daily morning surveys and sleep logs.

RESULTS

In a hierarchical mixed effect model that included all environmental variables and adjusted for elapsed sleep time and multiple demographic and behavioral variables, sleep efficiency calculated for consecutive 1-hour periods decreased in a dose-dependent manner with increasing levels of PM2.5, temperature, CO2, and noise. Sleep efficiency in the highest exposure quintiles was 3.2% (PM2.5, p < .05), 3.4% (temperature, p < .05), 4.0% (CO2, p < .01), and 4.7% (noise, p < .0001) lower compared to the lowest exposure quintiles (all p-values adjusted for multiple testing). Barometric pressure and humidity were not associated with sleep efficiency. Bedroom humidity was associated with subjectively assessed sleepiness and poor sleep quality (both p < .05), but otherwise environmental variables were not statistically significantly associated with actigraphically assessed total sleep time and wake after sleep onset or with subjectively assessed sleep onset latency, sleep quality, and sleepiness. Assessments of bedroom comfort suggest subjective habituation irrespective of exposure levels.

CONCLUSIONS

These findings add to a growing body of evidence highlighting the importance of the bedroom environment-beyond the mattress-for high-quality sleep.

Sleep Patterns, Eating Behavior and the Risk of Noncommunicable Diseases

Sleep is extremely important for the homeostasis of the organism. In recent years, various studies have been carried out to address factors related to sleep patterns and their influence on food choices, as well as on the onset of chronic noncommunicable diseases. The aim of this article is to provide a scientific literature review on the possible role of sleep patterns on eating behavior and the risk of noncommunicable diseases. A search was performed on Medline (PubMed interface) using several keywords (e.g., "Factors Influencing Sleep" OR "Sleep and Chronic Diseases"). Articles published between 2000 and the present date that relate sleep to cyclic metabolic processes and changes in eating behavior were selected. Changes in sleep patterns are increasingly detected today, and these modifications are mainly caused by work and lifestyle conditions as well as a growing dependence on electronic devices. Sleep deprivation and the resultant short sleep duration lead to an increased appetite via an increase in the hunger hormone (ghrelin) and a decrease in the satiety hormone (leptin). Nowadays, sleep is undervalued, and thus often impaired, with consequences for the performance of various body systems. Sleep deprivation alters physiological homeostasis and influences eating behavior as well as the onset of chronic diseases.

Effects of sleep fragmentation and partial sleep restriction on heart rate variability during night

We developed a cross-over study design with two interventions in randomized order to compare the effects of sleep fragmentation and partial sleep restriction on cardiac autonomic tone. Twenty male subjects (40.6 ± 7.5 years old) underwent overnight polysomnography during 2 weeks, each week containing one undisturbed baseline night, one intervention night (either sleep restriction with 5 h of sleep or sleep fragmentation with awakening every hour) and two undisturbed recovery nights. Parameters of heart rate variability (HRV) were used to assess cardiac autonomic modulation during the nights. Sleep restriction showed significant higher heart rate (p = 0.018) and lower HRV-pNN50 (p = 0.012) during sleep stage N1 and lower HRV-SDNN (p = 0.009) during wakefulness compared to the respective baseline. For HR and SDNN there were recovery effects. There was no significant difference comparing fragmentation night and its baseline. Comparing both intervention nights, sleep restriction had lower HRV high frequency (HF) components in stage N1 (p = 0.018) and stage N2 (p = 0.012), lower HRV low frequency (LF) (p = 0.007) regarding the entire night and lower SDNN (p = 0.033) during WASO during sleep. Sleep restriction increases sympathetic tone and decreases vagal tone during night causing increased autonomic stress, while fragmented sleep does not affect cardiac autonomic parameters in our sample.

The relationship between sleep quality, snoring symptoms, night shift and risk of stroke in Chinese over 40 years old

Objectives

To analyze the relationship between sleep quality, snoring symptoms, night shift and risk of stroke in Chinese population over 40 years old.

Methods

Based on the national screening and intervention program for high-risk population of stroke in 2016, 15,016 people completed the study of “the association between sleep and stroke,” 58,696 people completed the snoring questionnaire, and 58,637 people completed the night shift questionnaire.

Results

The proportion of coronary heart disease, hypertension, hyperlipidemia, diabetes, snoring, atrial fibrillation, stroke and high-risk group of stroke risk rating were higher in the group with poor sleep quality (p &lt; 0.05). The proportion of high blood pressure, hyperlipidemia, diabetes, atrial fibrillation, transient ischemic attack (TIA), or high-risk group of stroke risk rating was higher in snoring group (p &lt; 0.05). The body mass index (BMI), waist circumference, neck circumference, fasting blood glucose, triglyceride (TG), total cholesterol (TC), low density lipoprotein (LDL) and homocysteine (Hcy) levels in snoring group were higher than the non-snoring group, and high density lipoprotein (HDL) levels were lower (p &lt; 0.05). People with TIA, high risk for stroke, and high blood pressure were higher in night shift workers than non-night shift workers (p &lt; 0.05). The levels of BMI, fasting blood glucose, 2 h postprandial blood glucose, glycated hemoglobin, TG, TC, LDL, HDL and Hcy in night shift group were lower than the non-night shift group (p &lt; 0.05).

Conclusion

Sleep quality, snoring and night shift might be related to the risk factors of stroke.

Association of 3-year change in sleep duration with risk of all-cause mortality in Chinese older population: A national cohort study

BACKGROUND

Existing evidence on the association of dynamic change in sleep duration with risk of all-cause mortality in Chinese older population is limited. We aimed to explore the association of 3-year change in sleep duration with risk of all-cause mortality in a Chinese older population.

MATERIALS AND METHODS

A total of 5772 Chinese older participants (median age 82 years) were enrolled in the current study. Cox proportional-hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of 3-year change in sleep duration with risk of all-cause mortality. Subgroup analyses of the association between 3-year change in sleep duration and risk of all-cause mortality were conducted by age, sex and residence.

RESULTS

During a median of 4.08 years of follow-up, death developed in 1762 participants. Compared with -1 to <1 h/day change in sleep duration, the adjusted risk of all-cause mortality with < -3 h/day change in sleep duration may increase 26% (HR = 1.26, 95% CI: 1.05-1.52); the risk of all-cause mortality with 3-year change from short to long sleep duration, or long to short sleep duration versus stable normal sleep duration status was increased about 28% and 52%, respectively (HR = 1.28, 95% CI: 1.00-1.64 and HR = 1.52, 95% CI: 1.21-1.92). Subgroup analyses demonstrated that similar significant associations were observed among participants with 65 to <85 years, men and living in city and town.

CONCLUSIONS

Dynamic sleep duration change was significantly associated with risk of all-cause mortality. The current study suggests that sleep duration may be a non-invasive indicator for interventions aiming to reduction risk of all-cause mortality in Chinese older population.

Nutritional and lifestyle management of the aging journey: A narrative review

With age, the physiological responses to occasional or regular stressors from a broad range of functions tend to change and adjust at a different pace and restoring these functions in the normal healthy range becomes increasingly challenging. Even if this natural decline is somehow unavoidable, opportunities exist to slow down and attenuate the impact of advancing age on major physiological processes which, when weakened, constitute the hallmarks of aging. This narrative review revisits the current knowledge related to the aging process and its impact on key metabolic functions including immune, digestive, nervous, musculoskeletal, and cardiovascular functions; and revisits insights into the important biological targets that could inspire effective strategies to promote healthy aging.

Connecting insufficient sleep and insomnia with metabolic dysfunction

The global epidemic of obesity and type 2 diabetes parallels the rampant state of sleep deprivation in our society. Epidemiological studies consistently show an association between insufficient sleep and metabolic dysfunction. Mechanistically, sleep and circadian rhythm exert considerable influences on hormones involved in appetite regulation and energy metabolism. As such, data from experimental sleep deprivation in humans demonstrate that insufficient sleep induces a positive energy balance with resultant weight gain, due to increased energy intake that far exceeds the additional energy expenditure of nocturnal wakefulness, and adversely impacts glucose metabolism. Conversely, animal models have found that sleep loss-induced energy expenditure exceeds caloric intake resulting in net weight loss. However, animal models have significant limitations, which may diminish the clinical relevance of their metabolic findings. Clinically, insomnia disorder and insomnia symptoms are associated with adverse glucose outcomes, though it remains challenging to isolate the effects of insomnia on metabolic outcomes independent of comorbidities and insufficient sleep durations. Furthermore, both pharmacological and behavioral interventions for insomnia may have direct metabolic effects. The goal of this review is to establish an updated framework for the causal links between insufficient sleep and insomnia and risks for type 2 diabetes and obesity.

Association between napping and 24-hour blood pressure variability among university students: A pilot study

Background

Blood pressure variability (BPV) has been reported to be a predictor of cardiovascular and some cognitive diseases. However, the association between napping and BPV remains unknown. This study aimed to explore the association between napping and BPV.

Materials and methods

A cross-sectional study including 105 university students was conducted. Participants' 24 h ambulatory blood pressure monitoring (24 h ABPM) were measured, and napping behaviors were investigated. BPV were measured by the 24 h ABPM, included standard deviation (SD), coefficient of variation (CV), and average real variability (ARV).

Results

Among the participants, 61.9% reported daytime napping. We found that nap duration was significantly associated with daytime CV of diastolic blood pressure (DBP) (r = 0.250, P = 0.010), nighttime CV of systolic blood pressure (SBP) (r = 0.217, P = 0.026), 24 h WCV of DBP (r = 0.238, P = 0.014), 24 h ARV of SBP (r = 0.246, P = 0.011) and 24 h ARV of DBP (r = 0.291, P = 0.003). Compared with the no napping group, 24 h WCV of DBP, daytime CV of DBP, and daytime SD of DBP were significantly higher in participants with napping duration >60 min. With multiple regression analysis we found that nap duration was an independent predictor for 24 h ARV of SBP (β = 0.859, 95% CI, 0.101-1.616, P = 0.027) and 24 h ARV of DBP (β = 0.674, 95% CI, 0.173-1.175, P = 0.009).

Conclusions

Napping durations are associated with BPV among university students. Especially those with napping durations >60 min had a significantly higher BPV than those non-nappers.

Practices and Applications of Heart Rate Variability Monitoring in Endurance Athletes

Heart rate variability reflects fluctuations in the changes in consecutive heartbeats, providing insight into cardiac autonomic function and overall physiological state. Endurance athletes typically demonstrate better cardiac autonomic function than non-athletes, with lower resting heart rates and greater variability. The availability and use of heart rate variability metrics has increased in the broader population and may be particularly useful to endurance athletes. The purpose of this review is to characterize current practices and applications of heart rate variability analysis in endurance athletes. Important considerations for heart rate variability analysis will be discussed, including analysis techniques, monitoring tools, the importance of stationarity of data, body position, timing and duration of the recording window, average heart rate, and sex and age differences. Key factors affecting resting heart rate variability will be discussed, including exercise intensity, duration, modality, overall training load, and lifestyle factors. Training applications will be explored, including heart rate variability-guided training and the identification and monitoring of maladaptive states such as overtraining. Lastly, we will examine some alternative uses of heart rate variability, including during exercise, post-exercise, and for physiological forecasting and predicting performance.

Sleep and risk of hypertension in general American adults: the National Health and Nutrition Examination Surveys (2015-2018)

OBJECTIVE

The purpose of research is to investigate the associations of sleep factors separately and jointly with risk of hypertension.

METHODS

The National Health and Nutrition Examination Surveys (NHANES) is a nationally representative survey. Participants aged over 20 years with complete and credible data from the NHANES 2015-2016 and 2017-2018 waves were included. Hypertension was assessed based on self-report medical diagnoses, or antihypertensive medication use, or systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg. Sleep information (sleep duration, trouble sleeping, daytime sleepiness, self-reported snoring and sleep-related breathing issue) was obtained from household interview.

RESULTS

Of 7426 participants, the mean (standard deviation) age was 48.0 (17.3) years, 3845 (51.8%) were females. The prevalence of hypertension was 32.8%, and lower in those with 7-9 h sleep, no trouble sleeping, no excessive daytime sleepiness, no snoring or sleep apnea symptoms, decreased as the quantity of healthy sleep factors increased. The self-reported short sleep (odds ratio [OR]: 1.25, 95% confidence interval [CI]: 1.02-1.54, P  = 0.032), trouble sleeping (OR: 1.53, 95% CI: 1.20 to 1.95, P  = 0.001), excessive daytime sleepiness (OR: 1.17, 95% CI: 1.01-1.35, P  = 0.041) and sleep apnea symptoms (OR: 1.33, 95% CI: 1.10-1.61, P  = 0.004) were associated with 25%, 53%, 17% and 33% increased risk of hypertension, respectively. Participants with a poor sleep pattern was associated with higher hypertension risk (OR: 2.47, 95% CI: 1.90-3.22, P  < 0.001).

CONCLUSION

Sleep behaviors were cross-sectionally associated with a considerably higher hypertension risk.

Association between Wakeup Frequency at Night and Atherogenic Dyslipidemia: Evidence for Sex Differences

AIM

This study aimed to determine whether sleep disturbance, defined as the wakeup frequency at night, is associated with atherogenic dyslipidemia and to explore possible sex differences.

METHODS

A total of 1,368 adults aged 19-70 years were included in the study of lifestyles and atherogenic dyslipidemia at the National Taiwan University Hospital in the period of 2008-2012. They completed a questionnaire regarding lifestyle information and sleep quality, including sleep hour duration, use of sleeping pills, and wakeup frequency during nighttime sleep. The measured lipid profiles included total cholesterol, triglycerides, low- and high-density lipoprotein cholesterol (LDL-C and HDL-C, respectively), non-HDL-C, and small dense LDL-C (sdLDL-C). Multivariate logistic regression was performed to determine habitual interrupted sleep and the odds ratio of atherogenic dyslipidemia following adjustment for conventional risk factors and for sex-based subgroup analysis.

RESULTS

A wakeup frequency ≥ 3 times per night was independently associated with an increased risk [odds ratio (95% confidence interval)] of dyslipidemia was 1.96 (1.17-3.28), and non-HDL-C ≥ 160 mg/dL was 1.78 (1.09-2.89). A higher wakeup frequency was associated with increased atherogenic dyslipidemia in women than in men. The multivariate adjusted relative risks for non-HDL ≥ 160 mg/dL and cholesterol ≥ 200 mg/dL were 3.05 (1.27-7.34) and 4.01(1.29-12.45) for female individuals with insomnia and those with a wakeup frequency ≥ 2 times per night, respectively.

CONCLUSION

A higher wakeup frequency was associated with atherogenic dyslipidemia in Taiwanese adults, particularly in women. This study also provided another evidence of increasing cardiovascular diseases in subjects with habitual interrupted sleep.

Monitoring Effects of Sleep Extension and Restriction on Endurance Performance Using Heart Rate Indices

ABSTRACT

Roberts, SSH, Aisbett, B, Teo, W-P, and Warmington, S. Monitoring effects of sleep extension and restriction on endurance performance using heart rate indices. J Strength Cond Res 36(12): 3381-3389, 2022-Heart rate (HR) indices are useful for monitoring athlete fatigue or "readiness to perform." This study examined whether HR indices are sensitive to changes in readiness following sleep restriction (SR) and sleep extension (SE). Nine athletes completed a crossover study with 3 conditions: SR, normal sleep (NS), and SE. Each condition required completion of an endurance time trial (TT) on 4 consecutive days (D1-D4). Athletes slept habitually before D1; however, time in bed was reduced by 30% (SR), remained normal (NS), or extended by 30% (SE), on subsequent nights (D1-D3). Daily resting HR and HR variability were recorded. The maximal rate of HR increase and HR recovery was determined from a constant-load test before TTs. Exercise intensity ratios incorporating mean HR, mean power (W), and perceived exertion (RPE) were recorded at steady state during constant-load tests (W:HR SS ) and during TTs (W:HR TT , RPE:HR TT ). Compared with D4 of NS, RPE:HR TT was lower on D4 of SE ( p = 0.008)-when TT performances were faster. Compared with D1 of SR, RPE:HR TT was higher on D3 and D4 of SR ( p < 0.02). Moderate correlations were found between percentage changes in W:HR TT and changes in TT finishing time in SR ( r = -0.67, p = 0.049) and SE ( r = -0.69, p = 0.038) conditions. Intensity ratios incorporating mean HR seem sensitive to effects of sleep duration on athlete readiness to perform. When interpreting intensity ratios, practitioners should consider potential effects of prior sleep duration to determine whether sleep-promoting interventions are required (e.g., SE).

The association between sleep deprivation and arterial pressure variations: a systematic literature review

Objectives

Arterial hypertension is a cardiovascular disease defined as a sustained high blood pressure, constituting an important risk factor for the development of heart diseases, such as coronary heart disease and heart failure. At the same time, pathophysiological pathways underlying sleeping deprivation provides biological plausibility for a causation connection between sleep deprivation and acute or chronic blood pressure elevation, such as the mechanism behind blood pressure dipping at night, which strongly relies on reduced sympathetic activity provided by sleep, besides empirical and clinical evidence suggesting that sleep disorders incidence is correlate with posterior development of arterial hypertension. The aim of this study was to systematically review published studies analyzing the possible relationship between sleep deprivation and variations in blood pressure during nighttime and daytime.

Methods

The research was carried out in the second semester of 2020 following the PRISMA model and using the LILACS, MEDLINE and COCHRANE (CENTRAL) databases. The keywords used were associated using the Boolean method. Only trials and studies in humans unrelated to sleep apnea were included, in an attempt to answer the question proposed. Duplications and articles outside the topic were excluded.

Results

After the selection processes, fourteen studies were left, which were classified, depending on the findings, in four categories: 1) blood pressure differences only in sleep deprivation's night; 2) blood pressure differences only in the following day after sleep deprivation's night; 3) blood pressure differences in both nights and 4) those that found no blood pressure differences.

Conclusion

It was found an increase in blood pressure on the night of sleep deprivation, suggesting a possible causality with an acute increase in blood pressure depending on the population studied. In general, sleep deprivation is acutely associated with blood pressure elevation or acute elevation of markers that suggest the role of compensatory mechanisms, such as increased natriuresis and increased parasympathetic activity.

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Sleep deprivation results in increased simpathetic activity.

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Chronic sleep deprivation might lead to systemic arterial hypertension.

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Increased parasympathetic activity in acute sleep deprivation play a role as compensatory mechanism.

Comprehensive effects of various nutrients on sleep

Sleep problems have become common among people today. Sleep disorders are closely associated with physiological and psychological diseases. Among the ways of improving objective or subjective sleep quality, controlling elements associated with food intake can be more efficient than other methods in terms of time and cost. Therefore, the purpose of this study was to understand the effects of nutrients and natural products on sleep. An extensive literature search was conducted, and related articles were identified through online databases, such as Elsevier, Google Scholar, PubMed, Springer, and Web of Science. Expert opinion, conference abstracts, unpublished studies, and studies published in languages other than English were excluded from this review. The effects of macronutrients and diet adjustment on sleep differed. Although not all nutrients independently affect sleep, they comprehensively affect it through tryptophan metabolism. Furthermore, natural foods related to GABA have an effect on sleep similar to that of sleeping pills. Taken together, our results suggest that humans can control both their objective and subjective sleep quality based on their lifestyle and food consumption. However, until now, direct studies on the relationship between human sleep and nutrition, such as clinical trials, have been insufficient. As both objective and subjective sleep quality are the factors determining the quality of life of individuals, further studies on those are needed to improve it.

Associations between the timing of different foods’ consumption with cardiovascular disease and all-cause mortality among adults with sleep disorders

Introduction

People with sleep disorders are under disrupted biological rhythms. Whether changing the timing of specific food consumption contributes to decreasing cardiovascular and all-cause risk is unknown.

Methods

A total of 8,005 participants with sleep disorders were selected from the U.S. National Health and Nutrition Examination Survey (NHANES) from 2005 to 2014. Cox proportional hazards regression models were used to analyze the relationship between the consumption time of foods and cardiovascular disease (CVD) and all-cause death. Moreover, equivalent food substitution models were carried out to evaluate the alterations in the risk of CVD mortality for the changed food intake time.

Results

After adjusting for multiple confounders, participants who consume red and orange vegetables, starchy vegetables, and fermented dairy in the morning (hazard ratio (HR)_{red and orange vegetables} = 0.45, 95% CI: 0.26–0.81; HR_{starchy vegetables} = 0.47, 95% CI: 0.25–0.88; HR_{fermented dairy} = 0.57, 95% CI: 0.36–0.89) and milk and eggs in the evening contribute to reducing the likelihood of death from CVD (HR_milk = 0.65, 95% CI: 0.43–0.96; HR_eggs = 0.72, 95% CI: 0.53–0.98). Iso-calorically switching 0.1 serving of starchy vegetable and fermented dairy and milk intake from one period to another does significantly reduce the mortality risk of CVD.

Conclusion

Higher intake of red and orange vegetables, starchy vegetables, and fermented dairy in the morning and milk and eggs in the evening confers a lower risk of CVD among individuals with sleep disorders.

Effect of selective sleep deprivation on heart rate variability in post-90s healthy volunteers

The 5-minute frequency domain method was used to examine the effects of polysomnography (PSG)-guided acute selective sleep deprivation (REM/SWS) on the cardiovascular autonomic nervous system, heart rate, and rhythm in healthy volunteers to understand the relationship between cardiac neuro regulatory homeostasis and cardiovascular system diseases in healthy subjects. The study included 30 healthy volunteers selected through the randomized-controlled method, randomly divided into REM sleep deprivation and SWS sleep deprivation groups. PSG analyses and dynamic electrocardiogram monitoring were done at night, during slow wave sleep or REM sleep. An all-night sleep paradigm, without any interruptions, was tested 3 times for comparison. The frequency domain parameter method was further used to monitor the volunteers 5 min before and after a period of sleep deprivation. According to the characteristics of the all-night sleep scatter plot, healthy volunteers were divided into abnormal and normal scatter plot groups. When compared with the period before sleep deprivation, high frequency (HF) and normalized high-frequency component (HFnu) were found to be decreased. Normalized low-frequency component (LFnu) increased in the abnormal scatter plot group after sleep deprivation, and this difference was statistically significant (P < 0.05). The scatter plot also showed that very low frequency (VLF) increased only in the normal group after deprivation and this difference, as well, was statistically significant (P < 0.05). The increase in diastolic blood pressure in the abnormal group was statistically significant (P < 0.05), but the change in blood pressure in the normal group was not statistically significant (P > 0.05). There are 62.5% of the patients and 20% of the employees that were observed to have abnormal whole-night sleep patterns during the uninterrupted whole-night sleep regime. Patients with atrial or ventricular premature beats (more than 0.1%), and those with ST-t changes during sleep, were all ascertained as abnormal. We concluded that some healthy people could face unstable autonomic nervous functioning related to their long-term tension, anxiety, time urgency, hostility, and other chronic stress states. In the face of acute sleep deprivation selectivity, mild stress based excitability of the vagus nerve is reduced, which diminishes the protective function, making them susceptible to conditions such as premature ventricular arrhythmia.

Symptom phenotypes in Pulmonary Arterial Hypertension: The PAH “Symptome”

Women with pulmonary arterial hypertension (PAH) experience multiple symptoms, including dyspnea, fatigue, and sleep disturbance, that impair their health‐related quality of life (HRQOL). However, we know little about phenotypic subgroups of patients with PAH with similar, concurrent, multiple symptoms. The objectives of this study were to define the “symptome” by symptom cluster phenotypes and compare characteristics such as biomarkers, cardiac structure and function (echocardiography), functional capacity (6‐min walk distance), and HRQOL between the groups. This cross‐sectional study included 60 women with PAH. Subjects completed an assessment battery: Pulmonary Arterial Hypertension Symptom Scale, Pittsburgh Sleep Quality Index, Multidimensional Dyspnea Profile, Patient‐Reported Outcomes Measurement Information System (PROMIS®) Physical Function, PROMIS® Sleep‐Related Impairment, and the emPHasis‐10. Subjects also underwent transthoracic echocardiography, phlebotomy, 6‐min walk distance, and actigraphy. The three symptoms of dyspnea, fatigue, and sleep disturbance were used to define the symptom clusters. Other PAH symptoms, plasma and serum biomarkers, cardiac structure and function (echocardiography), exercise capacity (6‐min walk distance), sleep (actigraphy), and HRQOL were compared across phenotypes. The mean age was 50 ± 18 years, 51% were non‐Hispanic white, 32% were non‐Hispanic Black and 40% had idiopathic PAH. Cluster analysis identified Mild (n = 28, 47%), Moderate (n = 20, 33%), and Severe Symptom Cluster Phenotypes (n = 12, 20%). There were no differences for age, race, or PAH etiology between the phenotypes. WHO functional class (p < 0.001), norepinephrine levels (p = 0.029), right atrial pressure (p = 0.001), physical function (p < 0.001), sleep onset latency (p = 0.040), and HRQOL (p < 0.001) all differed significantly across phenotypes. We identified three distinctive symptom cluster phenotypes (Mild, Moderate, and Severe) for women with PAH that also differed by PAH‐related symptoms, physical function, right atrial pressure, norepinephrine levels, and HRQOL. These phenotypes could suggest targeted interventions to improve symptoms and HRQOL in those most severely affected.

Effects of sleep deprivation on coronary heart disease

The presence of artificial light enables humans to be active 24 h a day. Many people across the globe live in a social culture that encourages staying up late to meet the demands of various activities, such as work and school. Sleep deprivation (SD) is a severe health problem in modern society. Meanwhile, as with cardiometabolic disease, there was an obvious tendency that coronary heart disease (CHD) to become a global epidemic chronic disease. Specifically, SD can significantly increase the morbidity and mortality of CHD. However, the underlying mechanisms responsible for the effects of SD on CHD are multilayered and complex. Inflammatory response, lipid metabolism, oxidative stress, and endothelial function all contribute to cardiovascular lesions. In this review, the effects of SD on CHD development are summarized, and SD-related pathogenesis of coronary artery lesions is discussed. In general, early assessment of SD played a vital role in preventing the harmful consequences of CHD.

Night blood pressure variability, brain atrophy, and cognitive decline

Background

Although blood pressure variability (BPV) has emerged as a novel risk factor for Alzheimer's disease, few studies have examined the effects of night BPV on brain structure and function. This study investigated the association of night BPV with brain atrophy and cognitive function changes.

Methods

The analysis included 1,398 participants with valid ambulatory blood pressure (BP) monitoring at baseline and both baseline and 4-year follow-up brain magnetic resonance images who were recruited from the Korean Genome and Epidemiology Study. Participants underwent a comprehensive neuropsychological test battery. BPV was derived from ambulatory BP monitoring and calculated as a standard deviation (SD) of 24-h and daytime and nighttime BP.

Results

During the median follow-up of 4.3 years, increased SD of night systolic or diastolic BP was an indicator of total brain volume reduction, while daytime BPV or night average BP was not associated with total brain volume changes. High SD of night systolic BP was associated with reduced gray matter (GM) volume, independent of average night BP, and use of antihypertensive drugs. It also was associated with a reduction of temporal GM volume, mostly driven by atrophy in the left entorhinal cortex and the right fusiform gyrus. In cognitive performance, high variability of night systolic BP was associated with a decrease in visual delayed recall memory and verbal fluency for the category.

Conclusion

Increased night BPV, rather than night mean BP, was associated with reduced brain volume and cognitive decline. High night BPV could be an independent predictor for rapid brain aging in a middle-aged population.

Predicting and mitigating fatigue effects due to sleep deprivation: A review

The deleterious effects of insufficient sleep have been well-established in the literature and can lead to a wide range of adverse health outcomes. Some of the most replicated findings demonstrate significant declines in cognitive functions such as vigilance and executive attention, psychomotor and cognitive speed, and working memory. Consequently, these decrements often lead individuals who are in a fatigued state to engage in substandard performance on everyday tasks. In the interest of curtailing these effects, prior work has attempted to identify mechanisms that predict fatigue onset and develop techniques to mitigate its negative consequences. Nonetheless, these results are often confounded by variables such as an individual’s resistance to fatigue, sleep history, and unclear distinctions about whether certain performance decrements are present due to fatigue or due to other confounding factors. Similar areas of research have provided approaches to produce models for the prediction of cognitive performance decrements due to fatigue through the use of multi-modal recording and analysis of fatigue-related responses. Namely, gathering and combining response information from multiple sources (i.e., physiological and behavioral) at multiple timescales may provide a more comprehensive representation of what constitutes fatigue onset in the individual. Therefore, the purpose of this review is to discuss the relevant literature on the topic of fatigue-related performance effects with a special emphasis on a variety of physiological and behavioral response variables that have shown to be sensitive to changes in fatigue. Furthermore, an increasing reliance on sleep loss, meant to assist in meeting the demands of modern society, has led to an upsurge in the relevance of identifying dependable countermeasures for fatigued states. As such, we will also review methods for the mitigation of performance effects due to fatigue and discuss their usefulness in regulating these effects. In sum, this review aims to inspire future work that will create opportunities to detect fatigue and mitigate its effects prior to the onset of cognitive impairments.

Relationship Between Attitudes and Beliefs About Sleep, Sleep Disturbance, and Pain Interference in Patients With Spinal Pain

OBJECTIVES

Sleep impairments are a strong predictor of pain, making sleep a potential interest when treating patients with spine pain. Typical beliefs about the importance of sleep in patients seeking care for spinal pain are unknown. The purpose of this study was to describe the beliefs and attitudes about sleep in patients seeking care for spinal pain and to examine the relationships between dysfunctional beliefs and attitudes about sleep (DBAS), disordered sleep, and pain interference.

MATERIALS AND METHODS

This cross-sectional study included patients presenting to physical therapy with spine pain. Participants completed questionnaires including demographics, medical history, pain interference (pain, enjoyment, and general activity), DBAS-16, and sleep-related impairment (Patient-Reported Outcome Measurement Information System). Correlations were calculated between DBAS-16 scores and measures of sleep quality/quantity, and a generalized linear model was used to investigate the predictive ability of DBAS-16 scores on pain interference.

RESULTS

The mean DBAS-16 score was 4.22 (SD=2.03), with 52.5% of participants having DBAS. There was a strong relationship between DBAS-16 and Patient-Reported Outcome Measurement Information System ( rs =0.7; P <0.001). For every point higher score on the DBAS-16, pain interference scores increased by approximately half a point (B=0.46; 95% CI 0.33, 0.59, 1.80; P <0.001).

DISCUSSION

These results highlight a strong relationship between beliefs and attitudes about sleep and measures of sleep quality/quantity and a linear association with pain interference scores. These findings provide a rationale for targeting beliefs and attitudes about sleep when managing pain-related symptoms in patients seeking care for spine pain.

Environmental Noise and Effects on Sleep: An Update to the WHO Systematic Review and Meta-Analysis

BACKGROUND

Nighttime noise carries a significant disease burden. The World Health Organization (WHO) recently published guidelines for the regulation of environmental noise based on a review of evidence published up to the year 2015 on the effects of environmental noise on sleep.

OBJECTIVES

This systematic review and meta-analysis will update the WHO evidence review on the effects of environmental noise on sleep disturbance to include more recent studies.

METHODS

Investigations of self-reported sleep among residents exposed to environmental traffic noise at home were identified using Scopus, PubMed, Embase, and PsycINFO. Awakenings, falling asleep, and sleep disturbance were the three outcomes included. Extracted data were used to derive exposure-response relationships for the probability of being highly sleep disturbed by nighttime noise [average outdoor A-weighted noise level (Lnight) 2300-0700 hours] for aircraft, road, and rail traffic noise, individually. The overall quality of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria.

RESULTS

Eleven studies (n=109,070 responses) were included in addition to 25 studies (n=64,090 responses) from the original WHO analysis. When sleep disturbance questions specifically mentioned noise as the source of disturbance, there was moderate quality of evidence for the probability of being highly sleep disturbed per 10-dB increase in Lnight for aircraft [odds ratio (OR)=2.18; 95% confidence interval (CI): 2.01, 2.36], road (OR=2.52; 95% CI: 2.28, 2.79), and railway (OR=2.97; 95% CI: 2.57, 3.43) noise. When noise was not mentioned, there was low to very low quality of evidence for being sleep disturbed per 10-dB increase in Lnight for aircraft (OR=1.52; 95% CI: 1.20, 1.93), road (OR=1.14; 95% CI: 1.08, 1.21), and railway (OR=1.17; 95% CI: 0.91, 1.49) noise. Compared with the original WHO review, the exposure-response relationships closely agreed at low (40 dB Lnight) levels for all traffic types but indicated greater disturbance by aircraft traffic at high noise levels. Sleep disturbance was not significantly different between European and non-European studies.

DISCUSSION

Available evidence suggests that transportation noise is negatively associated with self-reported sleep. Sleep disturbance in this updated meta-analysis was comparable to the original WHO review at low nighttime noise levels. These low levels correspond to the recent WHO noise limit recommendations for nighttime noise, and so these findings do not suggest these WHO recommendations need revisiting. Deviations from the WHO review in this updated analysis suggest that populations exposed to high levels of aircraft noise may be at greater risk of sleep disturbance than determined previously. https://doi.org/10.1289/EHP10197.

Effects of Sleep Quality on Academic Performance and Psychological Distress Among Medical Students in Saudi Arabia

Background: Sleep hygiene habits are essential to maintaining a healthy lifestyle. Sleep deprivation is a prevalent problem worldwide. Multiple studies have shown a high prevalence of sleep insufficiency among medical students due to high academic load, caffeine intake, and high-stress levels. Objectives: This study explores the relationship between sleep quality, academic performance, and psychological distress among medical students at Alfaisal University, Riyadh, Saudi Arabia. Methods: This cross-sectional study was conducted on medical students of all academic years at Alfaisal University, Riyadh. Two popular surveys – the PSQI and K10 - were used to assess sleep quality and psychological distress, respectively. In addition, the survey contained questions on socio-demographics and academic performance. Sociodemographic characteristics were assessed across groups having poor and good sleep quality. In multivariate analysis, we employed conscious variable selection to develop models. All statistical tests were two-sided at P < 0.05 as statistically significant. Results: A total of 241 respondents participated in the study. Most respondents reported poor sleep quality (75.93%). The highest psychological distress was reported among respondents with poor sleep quality (48.63%). The relationship between Kessler's Psychological Distress score and sleep quality score was significantly positive and linear (P < 0.0001). The mean PSQI score was higher in students with lower GPAs (1.50 - 2.99) than in those with higher GPAs (3.00 - 4.00). This shows that those students who sleep well perform academically better. Conclusions: The quality of sleep among medical students is poor, which is associated with psychological distress and poor academic performance. It is highly suggested that the awareness of sleep hygiene with healthy sleep habits be campaigned among medical students. Also, academic mentors, program directors, and coordinators play a crucial role in ensuring that medical students are not academically overwhelmed.

Sympathetic neural responses to sleep disorders and insufficiencies

Short sleep duration and poor sleep quality are associated with cardiovascular risk, and sympathetic nervous system (SNS) dysfunction appears to be a key contributor. The present review will characterize sympathetic function across several sleep disorders and insufficiencies in humans, including sleep deprivation, insomnia, narcolepsy, and obstructive sleep apnea (OSA). We will focus on direct assessments of sympathetic activation, e.g., plasma norepinephrine and muscle sympathetic nerve activity, but include heart rate variability (HRV) when direct assessments are lacking. The review also highlights sex as a key biological variable. Experimental models of total sleep deprivation and sleep restriction are converging to support several epidemiological studies reporting an association between short sleep duration and hypertension, especially in women. A systemic increase of SNS activity via plasma norepinephrine is present with insomnia and has also been confirmed with direct, regionally specific evidence from microneurographic studies. Narcolepsy is characterized by autonomic dysfunction via both HRV and microneurographic studies but with opposing conclusions regarding SNS activation. Robust sympathoexcitation is well documented in OSA and is related to baroreflex and chemoreflex dysfunction. Treatment of OSA with continuous positive airway pressure results in sympathoinhibition. In summary, sleep disorders and insufficiencies are often characterized by sympathoexcitation and/or sympathetic/baroreflex dysfunction, with several studies suggesting women may be at heightened risk.

Effects of curtailed sleep on cardiac stress biomarkers following high-intensity exercise

Objective

Physical exercise—especially at high intensity—is known to impose cardiac stress, as mirrored by, e.g., increased blood levels of cardiac stress biomarkers such as cardiac Troponin T (cTnT) and NT-proBNP. We examined healthy young participants to determine whether a few nights of short sleep duration alter the effects of acute exercise on these blood biomarkers.

Methods

Sixteen men participated in a randomized order in a crossover design, comprising three consecutive nights of a) normal sleep duration (NS, 8.5 h of sleep/night) and b) sleep restriction (SR, 4.25 h of sleep/night). Blood was repeatedly sampled for determination of NT-proBNP and cTnT serum levels before and after a high-intensity exercise protocol (i.e., 75% VO₂^maxReserve cycling on an ergometer).

Results

Under pre-exercise sedentary conditions, blood levels of cTnT and NT-proBNP did not significantly differ between the sleep conditions (P > 0.10). However, in response to exercise, the surge of circulating cTnT was significantly greater following SR than NS (+37–38% at 120–240 min post-exercise, P ≤ 0.05). While blood levels of NT-proBNP rose significantly in response to exercise, they did not differ between the sleep conditions.

Conclusion

Recurrent sleep restriction may increase the cardiac stress response to acute high-intensity exercise in healthy young individuals. However, our findings must be further confirmed in women, older subjects and in patients with a history of heart disease.

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Chronic sleep curtailment increases the risk of cardiovascular disease.

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Here, we examined whether exercise-induced cardiac strain in healthy young adults is altered by sleep curtailment.

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Blood levels of the cardiac stress marker troponin were higher after exercise under conditions of recurrent sleep restriction.

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Sleep restriction may increase exercise-induced cardiac strain in adults.

A Time to Rest, a Time to Dine: Sleep, Time-Restricted Eating, and Cardiometabolic Health

Cardiovascular disease (CVD) poses a serious health and economic burden worldwide. Modifiable lifestyle factors are a focus of research into reducing the burden of CVD, with diet as one of the most investigated factors. Specifically, the timing and regularity of food intake is an emerging research area, with approaches such as time-restricted eating (TRE) receiving much attention. TRE involves shortening the time available to eat across the day and is associated with improved CVD outcomes compared with longer eating windows. However, studies that have examined TRE have not considered the impact of sleep on CVD outcomes despite recent evidence showing that sleep duration can influence the timing and amount of food eaten. In this article, we argue that as TRE and sleep influence each other, and influence the same cardiometabolic parameters, experiencing inadequate sleep may attenuate any positive impact TRE has on CVD. We examine the relationship between TRE and CVD, with sleep as a potential mediator in this relationship, and propose a research agenda to investigate this relationship. This will provide necessary evidence to inform future interventions aimed at reducing the burden of CVD.

Self-perceived quality of sleep among COPD patients in Greece: the SLEPICO study

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide accompanied by a substantial social and economic burden for the patient and the society. Poor sleep quality among COPD patients is frequently unnoticed and unaddressed by physicians and patients themselves, although it is a major source of further deterioration of these patients' quality of life. The aim of the present study was to record the quality of sleep in COPD patients among the Greek population and correlate these findings with various features of these patients, using the COPD and Asthma Sleep Impact Scale (CASIS). This was a cross-sectional observational study. Forty different variables (demographics, vital sign measurements, COPD-related medical history parameters, comorbidities, CASIS questionnaire results, COPD assessment test, COPD severity based on spirometry measurements, COPD stage based on the ABCD assessment approach, inhaled COPD treatment report) were collected from 3454 nation-wide COPD patients (Greece). The study sample consisted of COPD patients, mainly male (73%) with a median age of 69 years and a median BMI of 27.2. More than half of COPD patients (60.6%) suffered from moderate disease severity and 23.8% from severe disease, while less than half (42.1%) suffered from at least one exacerbation of the disease over the last year prior study enrollment. About 14% reported frequent to very frequent issues affecting their sleep quality, between a fourth and a third of them reported occasional night sleep disturbances, and at least half of them reported no or very infrequent problems in their night sleep. Our study indicates that the COPD assessment test (CAT) and the spirometry-based disease severity can predict the poorness in the quality of sleep (F2,3451 = 1397.5, p < 0.001, adj. R2 = 0.45) as assessed by CASIS score, and that the latter also correlates with age (ρ = 0.122, p < 0.001) and disease duration (ρ = 0.104, p < 0.001). On the contrary, there appears to be no correlation between sleep quality and number of exacerbations. Finally, untreated patients with COPD suffer from poorer quality of sleep compared to treated subjects, independently of the use of inhaled corticosteroids (F2,3451 = 21.65, p < 0.001). The results of the SLEPICO study show that increased age, prolonged disease duration, and especially CAT score ≥ 10, and severe COPD stage, might act as important indicators for deterioration in the quality of sleep, with potential consequences in the daily routine of those patients, thus urging potentially for further pharmacological interventions or modifications.

Noise levels in the dialysis unit and its relationship with sleep quality and anxiety in patients receiving HD: A pilot study

INTRODUCTION

HD unit is a noisy environment for patients, and noise can affect anxiety levels and sleep quality.

METHODS

The aim of the study is to determine noise level, the relationship between noise levels, and sleep quality and anxiety in patients in HD unit. A descriptive and observational study design was used. Three Benetech GM1351 manual sound-level meters were used to measure noise. A patient information form, the State Anxiety Inventory, and the modified Post-Sleep Inventory were used for data collection.

RESULTS

The noise range detected in the HD unit ranges from 48.40 to 72 dB(A). Our findings show that patients in the HD unit are exposed to high noise levels and the noise significantly negatively impacts quality of sleep and anxiety level of the patients.

CONCLUSIONS

It is important to be aware that HD patients are constantly exposed to high levels of noise and to plan nursing interventions to reduce this noise level.

Sleep Duration and Hypertension: Epidemiological Evidence and Underlying Mechanisms

While the contribution of several physiological systems to arterial blood pressure regulation has been studied extensively, the role of normal and disrupted sleep as a modifiable determinant of blood pressure control, and in the pathophysiology of hypertension, has only recently emerged. Several sleep disorders, including sleep apnea and insomnia, are thought to contribute to the development of hypertension, although less attention is paid to the relationship between sleep duration and blood pressure independent of sleep disorders per se. Accordingly, this review focuses principally on the physiology of sleep and the consequences of abnormal sleep duration both experimentally and at the population level. Clinical implications for patients with insomnia who may or may not have abbreviated sleep duration are explored. As a corollary, we further review studies of the effects of sleep extension on blood pressure regulation. We also discuss epidemiological evidence suggesting that long sleep may also be associated with hypertension and describe the parabolic relationship between total sleep time and blood pressure. We conclude by highlighting gaps in the literature regarding the potential role of gut microbial health in the cross-communication of lifestyle patterns (exercise, diet, and sleep) with blood pressure regulation. Additionally, we discuss populations at increased risk of short sleep, and specifically the need to understand mechanisms and therapeutic opportunities in women, pregnancy, the elderly, and in African Americans.

Effects of Acute Partial Sleep Deprivation and High-Intensity Interval Exercise on Postprandial Network Interactions

Introduction: High-intensity interval exercise (HIIE) is deemed effective for cardiovascular and autonomic nervous system (ANS) health-related benefits, while ANS disturbance increases the risk for cardiovascular disease (CVD). Postprandial lipemia and acute-partial sleep deprivation (APSD) are considered as CVD risk factors due to their respective changes in ANS. Exercising in the morning hours after APSD and have a high-fat breakfast afterwards may alter the interactions of the cardiovascular, autonomic regulation, and postprandial lipemic systems threatening individuals' health. This study examined postprandial network interactions between autonomic regulation through heart rate variability (HRV) and lipemia via low-density lipoprotein (LDL) cholesterol in response to APSD and HIIE. Methods: Fifteen apparently healthy and habitually good sleepers (age 31 ± 5.2 SD yrs) completed an acute bout of an isocaloric HIIE (in form of 3:2 work-to-rest ratio at 90 and 40% of VO₂ reserve) after both a reference sleep (RSX) and 3-3.5 h of acute-partial sleep deprivation (SSX) conditions. HRV time and frequency domains and LDL were evaluated in six and seven time points surrounding sleep and exercise, respectively. To identify postprandial network interactions, we constructed one correlation analysis and one physiological network for each experimental condition. To quantify the interactions within the physiological networks, we also computed the number of links (i.e., number of significant correlations). Results: We observed an irruption of negative links (i.e., negative correlations) between HRV and LDL in the SSX physiological network compared to RSX. Discussion: We recognize that a correlation analysis does not constitute a true network analysis due to the absence of analysis of a time series of the original examined physiological variables. Nonetheless, the presence of negative links in SSX reflected the impact of sleep deprivation on the autonomic regulation and lipemia and, thus, revealed the inability of HIIE to remain cardioprotective under APSD. These findings underlie the need to further investigate the effects of APSD and HIIE on the interactions among physiological systems.

Sleep and cardiovascular outcomes in relation to nocturnal hypertension: the J-HOP Nocturnal Blood Pressure Study

There is a lack of data on how nighttime blood pressure (BP) might modify the relationship between sleep duration and cardiovascular disease (CVD) risk. Self-reported sleep duration data were available for 2253/2562 patients from the J-HOP Nocturnal BP study; of these, 2236 had complete follow-up data (mean age 63.0 years, 83% using antihypertensive drugs). CVD outcomes included stroke, coronary artery disease (CAD), and atherosclerotic CVD (ASCVD [stroke + CAD]). Associations between sleep duration and nighttime home BP (measured using a validated, automatic, oscillometric device) were determined. During a mean follow-up of 7.1 ± 3.8 years, there were 133 ASCVD events (52 strokes and 81 CAD events). Short sleep duration (<6 versus ≥6 and <9 h/night) was significantly associated with the risk of ASCVD (hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.07-3.22), especially stroke (HR 2.47, 95% CI 1.08-5.63). When nighttime systolic BP was <120 mmHg, those with a sleep duration <6 versus ≥6 and <9 h/night had a significantly higher risk of ASCVD and CAD events (HR [95% CI] 3.46 [1.52-7.92] and 3.24 [1.21-8.69], respectively). Even patients with "optimal" sleep duration (≥6 and <9 h/night) were at significantly higher risk of stroke when nighttime systolic BP was uncontrolled (HR [95% CI] 2.76 [1.26-6.04]). Adding sleep duration and nighttime BP to a base model with standard CVD risk factors significantly improved model performance for stroke (C-statistic 0.795, 95% CI 0.737-0.856; p = 0.038). These findings highlight the importance of both optimal sleep duration and control of nocturnal hypertension for reducing the risk of CVD, especially stroke. Clinical Trial registration: URL: http://www.umin.ac.jp/icdr/index.html . Unique identifier: UMIN000000894.

Effects of High-Intensity Interval Exercise and Acute Partial Sleep Deprivation on Cardiac Autonomic Modulation

Sleep deprivation in healthy adults has been associated with disrupted autonomic nervous system function, which in turn has been linked to cardiovascular health. High-intensity interval exercise (HIIE) may affect both sleep and cardiac autonomic modulation. Purpose: To investigate the impact of acute partial sleep deprivation on autonomic cardiac regulation before and after an acute bout of HIIE and the length of time for the autonomic system to return to resting levels. Methods: Fifteen healthy males with body mass index (BMI) of 25.8 ± 2.7 kg·m^-2 and age 31 ± 5 y participated in a reference sleep (~9.5 hr) with no HIIE (RS), a reference sleep with HIIE (RSX), and an acute partial sleep deprivation (~3.5 hr) with HIIE (SDX). HIIE was performed in 3:2 intervals at 90% and 40% of VO₂ reserve. Autonomic regulation through HRV selected time and frequency domain indices were recorded the night before, the morning of the next day, 1 hr-, 2 hr-, 4hr-, and 6-hr post-exercise. Results: HIIE performed in a 3:2 W:R ratio decreased the HRV (p < .05) at 1-hr post exercise and it took up to 4 hr to return to baseline levels. Parasympathetic related HRV indices increased the morning of the next day for SDX (p < .05). Acute partial sleep deprivation and HIIE did not modify the HRV responses compared to reference sleep and HIIE. Conclusion: HRV disturbance typically seen in responses to an acute episode of HIIE is not influenced by acute partial sleep deprivation.

Role of sleep deprivation in immune-related disease risk and outcomes

Modern societies are experiencing an increasing trend of reduced sleep duration, with nocturnal sleeping time below the recommended ranges for health. Epidemiological and laboratory studies have demonstrated detrimental effects of sleep deprivation on health. Sleep exerts an immune-supportive function, promoting host defense against infection and inflammatory insults. Sleep deprivation has been associated with alterations of innate and adaptive immune parameters, leading to a chronic inflammatory state and an increased risk for infectious/inflammatory pathologies, including cardiometabolic, neoplastic, autoimmune and neurodegenerative diseases. Here, we review recent advancements on the immune responses to sleep deprivation as evidenced by experimental and epidemiological studies, the pathophysiology, and the role for the sleep deprivation-induced immune changes in increasing the risk for chronic diseases. Gaps in knowledge and methodological pitfalls still remain. Further understanding of the causal relationship between sleep deprivation and immune deregulation would help to identify individuals at risk for disease and to prevent adverse health outcomes.

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.

Acute Myocardial Infarction and Daylight Saving Time Transitions: Is There a Risk?

Available evidence on the risk of acute myocardial infarction (AMI) in the days after the spring daylight saving time (DST) transition suggests either a modest increase or no risk increase. Partial sleep deprivation and enhanced circadian clock misalignment have been implicated as the underlying mechanisms for increased AMI risk, probably via enhanced thrombo-inflammatory processes and activation of the sympathetic nervous system. Most of the studies, as we suggest as a perspective here, have used potentially inappropriate control periods, including the two post-transitional weeks, because adjustment after the spring DST transition lasts at least four weeks for all chronotypes and probably even beyond this period for late chronotypes. The most plausible conclusions, at the moment, for the risk of AMI after the spring DST transition are: (1) the risk is increased, (2) a relatively modest risk increase could be currently underestimated or in some studies undetected, (3) late chronotypes and/or individuals with high levels of social jetlag (a proxy for circadian clock misalignment) could be more affected by the phenomenon, and (4) underlying pathophysiological mechanisms should be further explored. As a significant part of world’s population continues to be affected by the biannual clock change, the question of increased AMI risk in the post-transitional period remains an intriguing public health issue.