Sleep duration and risk of stroke mortality among Chinese adults: Singapore Chinese health study

Pre-morbid sleep disturbance and its association with stroke severity: results from the international INTERSTROKE study

BACKGROUND AND PURPOSE

Whilst sleep disturbances are associated with stroke, their association with stroke severity is less certain. In the INTERSTROKE study, the association of pre-morbid sleep disturbance with stroke severity and functional outcome following stroke was evaluated.

METHODS

INTERSTROKE is an international case-control study of first acute stroke. This analysis included cases who completed a standardized questionnaire concerning nine symptoms of sleep disturbance (sleep onset latency, duration, quality, nocturnal awakening, napping duration, whether a nap was planned, snoring, snorting and breathing cessation) in the month prior to stroke (n = 2361). Two indices were derived representing sleep disturbance (range 0-9) and obstructive sleep apnoea (range 0-3) symptoms. Logistic regression was used to estimate the magnitude of association between symptoms and stroke severity defined by the modified Rankin Score.

RESULTS

The mean age of participants was 62.9 years, and 42% were female. On multivariable analysis, there was a graded association between increasing number of sleep disturbance symptoms and initially severe stroke (2-3, odds ratio [OR] 1.44, 95% confidence interval [CI] 1.07-1.94; 4-5, OR 1.66, 95% CI 1.23-2.25; >5, OR 2.58, 95% CI 1.83-3.66). Having >5 sleep disturbance symptoms was associated with significantly increased odds of functional deterioration at 1 month (OR 1.54, 95% CI 1.01-2.34). A higher obstructive sleep apnoea score was also associated with significantly increased odds of initially severe stroke (2-3, OR 1.48; 95% CI 1.20-1.83) but not functional deterioration at 1 month (OR 1.19, 95% CI 0.93-1.52).

CONCLUSIONS

Sleep disturbance symptoms were common and associated with an increased odds of severe stroke and functional deterioration. Interventions to modify sleep disturbance may help prevent disabling stroke/improve functional outcomes and should be the subject of future research.

Exploring the potential relationship between short sleep risks and cognitive function from the perspective of inflammatory biomarkers and cellular pathways: Insights from population-based and mice studies

AIMS

The molecular mechanism of short-sleep conditions on cognition remains largely unknown. This research aimed to investigate associations between short sleep, inflammatory biomarkers and cognitive function in the US population (NHANES data 2011-2014) and explore cellular mechanisms in mice.

METHODS

Systemic immune-inflammation index (SII) was calculated using blood-cell based biomarkers. Further, we employed integrated bioinformatics and single-cell transcriptomics (GSE137665) to examine how short sleep exposure influenced the molecular pathways associated with inflammation in the brain. To explore the signaling pathways and biological processes of sleep deprivation, we carried out enrichment analyses utilizing the GO and KEGG databases.

RESULTS

Population results showed that, compared with normal sleep group, severe short sleep was associated with lower cognitive ability in all the four tests. Moreover, a higher SII level was correlated with lower scores of cognitive tests. In mice study, elevated activation of the inflammatory pathway was observed in cell subgroups of neurons within the sleep deprivation and recovery sleep cohorts. Additionally, heightened expression of oxidative stress and integrated stress response pathways was noted in GABAergic neurons during sleep deprivation.

CONCLUSION

This study contributed to the understanding of the influence of short sleep on cognitive function and its cellular mechanisms.

The prevalence and associated factors of sleep deprivation among healthy college students in China: a cross-sectional survey

Background

The prevalence of sleep deprivation among college students is increasing and has a few associated factors.

Methods

The present study analyzed 2,142 college students from 28 provinces in China. The Chinese version of the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep duration. Binary logistic regression was conducted to explore the sleep deprivation related factors. Age and gender were controlled as covariates.

Results

Among the 2,142 college students (27.7% male, 72.3% female), 1,620 (75.6%) reported the average sleep duration was below 7 h per day for one month, 49.3% (1,055/2,142) slept 6∼7 h (contains 6 h), 21.0% (449/2,142) slept 5∼6 h (contains 5 h), and 5.4% (116/2,142) slept <5 h. Age increased the risk of sleep deprivation, the adjusted odds ratio = 1.05 (95% CI [1.01∼1.10]). The adjusted odds ratio (A-OR) for sleep deprivation was higher for students of more than 60 min nap duration per day (A-OR = 2.35, 95% CI [1.45∼3.80]), and age growth (A-OR = 1.05, 95% CI [1.01∼1.10]). In contrast, A-ORs were lower among sleeping inconsistency between work and rest days (A-OR = 0.61, 95% CI [0.49∼0.75]), accustomed to staying up late (A-OR = 0.45, 95% CI [0.36∼0.57]), staying up late to work or study (A-OR = 0.62, 95% CI [0.49∼0.78]), stress (A-OR = 0.75, 95% CI [0.58∼0.98]), and repeated thoughts in bed had (A-OR = 0.79, 95% CI [0.62∼0.99]).

Conclusions

Sleep deprivation is extremely common among healthy college students in China. It is necessary to perform methods maintaining enough sleep due to the current high incidence of sleep deprivation. Controlling the nap duration and getting enough sleep on rest days to replace missing hours of sleep on workdays might improve college students' sleep.

Sleep duration and risk of stroke and coronary heart disease: a 9-year community-based prospective study of 0.5 million Chinese adults

BACKGROUND

There is uncertainty about the optimum sleep duration for risk of different subtypes of stroke and ischaemic heart disease.

METHODS

The present analyses involved 409,156 adults in the China Kadoorie Biobank study without a prior history of coronary heart disease or stroke or insomnia symptoms. The mean age of study participants was 52 years and 59% were women. Self-reported sleep duration including daytime napping was recorded using a questionnaire. The adjusted hazard ratios (HRs) for disease outcomes associated with sleep duration were estimated by Cox proportional hazards after adjustment for confounding factors.

RESULTS

The overall mean (SD) sleep duration was 7.4 (1.4) hours. The associations of sleep duration with CVD types were U-shaped, with individuals reporting 7-8 h of sleep having the lowest risks. Compared with those who typically slept 7-8 h, individuals with very short sleep duration (≤ 5 h) had adjusted HRs of 1.10 (95% CI 1.04-1.16), 1.07 (1.01-1.13), 1.19 (1.06-1.33) and 1.23 (1.10-1.37) for total stroke, ischaemic stroke (IS), Intracerebral haemorrhage (ICH) and major coronary events (MCE), respectively. Likewise, individuals with very long sleep duration (≥ 10 h) had HRs of 1.12 (1.07-1.17), 1.08 (1.03-1.14), 1.23 (1.12-1.35) and 1.22 (1.10-1.34) for the same diseases, respectively, with little differences by sex and age. The patterns were similar for all-cause mortality.

CONCLUSIONS

While abnormal sleep duration (≤ 6 h or ≥ 9 h) was associated with higher risks of CVD, the risks were more extreme for those reporting ≤ 5 or ≥ 10 h, respectively and such individuals should be prioritised for more intensive treatment for CVD prevention.

Long Sleep Duration and Stroke-Highly Linked, Poorly Understood

Stroke is one of the leading causes of disability and mortality. Both short and long sleep durations are associated with adverse health outcomes. Cross-sectional studies have shown an increased prevalence of stroke in long sleepers. Long sleep duration increases stroke incidence and mortality in prospective epidemiological studies. Accumulating evidence suggests that the magnitude of the association between sleep and stroke appears to be stronger for longer sleep than shorter sleep, yielding a J-shaped curve. Potential links between long sleep duration and stroke include increased incidence of diabetes and atrial fibrillation, elevated levels of inflammation, arterial stiffness, and blood pressure variability. Long sleep duration is a strong marker and a plausible risk factor for stroke and should be considered in future scoring for risk stratification and stroke prevention.

Short sleep duration associated with the incidence of cardio-cerebral vascular disease: a prospective cohort study in Shanghai, China

IMPORTANCE

Sleep duration plays an important role in predicting CCVD incidence, and have implications for reducing the burden of CCVD. However, the association between sleep duration and predicted cardio-cerebral vascular diseases (CCVD) risk remains to be fully understood.

OBJECTIVE

To investigate the effects of sleep duration on the development of CCVD among Chinese community residents.

DESIGN

A prospective cohort study. The baseline survey was conducted from January 2013 to July 2013. The cohort has been followed until December 31, 2016 using a combination of in-person interviews and record linkages with the vital registry of Pudong New Area, Shanghai, China.

SUBJECTS

A total of 8245 Chinese community residents were initially enrolled in the cohort. Of those, 6298 underwent the follow-up examination.

EXPOSURE

Self-reported sleep duration and sleep quality were obtained via the questionnaire. Sleep duration was divided into five categories: ≤5, 6, 7, 8, or ≥ 9 h per day.

MAIN OUTCOME(S) AND MEASURE(S)

CCVD, Coronary heart disease (CHD) and Stroke occurrence, Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using Fine-Gray proportional subdistribution hazards models.

RESULTS

During a median follow-up of 3.00 years (IQR 2.92-3.08), we observed 370 participants have had incident CCVD events, of whom 230 had CHDs, 169 had strokes, and 29 had both. After adjustment for relevant confounders, short sleepers (≤ 5 h) had 83% higher risk of total CCVD incidence (HR: 1.83; 95% CI: 1.32-2.54), 82% higher risk of CHD incidence (HR: 1.82; 95% CI: 1.21-2.75), and 82% higher risk of stroke incidence (HR: 1.82; 95% CI: 1.12-2.98) in contrast to the reference group (7 h). Some of these U-shaped relationships varied by age, and were more pronounced in individuals aged < 65 years. Individuals who slept ≤ 5 h per day with baseline hypertension had the highest risk of CCVD incidence (HR: 3.38, 95% CI 2.08-5.48), CHD incidence (HR: 3.11, 95% CI 1.75-5.53), and stroke incidence (HR: 4.33, 95% CI 1.90-9.86), compared with those sleep 7 h and without baseline hypertension.

CONCLUSIONS

Short sleep duration is independently associated with greater incidence of CCVD, CHD and stroke.

Long Sleep Duration and Dissatisfaction with Sleep Quality Are Associated with Ischemic Stroke in Young Patients

INTRODUCTION

Suboptimal sleep duration and poor sleep quality have been proposed to increase stroke risk. However, their significance in young ischemic stroke is unclear. We aimed to investigate the importance of sleep duration and quality on young ischemic stroke patients.

METHODS

A multicenter matched case-control study was performed to evaluate under-recognized risk factors in young (<45 years) ischemic stroke patients in 8 tertiary hospitals in Korea. A total of 225 patients and 225 age- and sex-matched controls were enrolled in the same period. Detailed information about patients' demographics, socioeconomic state, and traditional and nontraditional risk factors including sleep-related factors were obtained using structured questionnaires. Risk of ischemic stroke was estimated using conditional logistic regression analysis.

RESULTS

Although average sleep duration was similar in patients and controls, patients were more likely to have long (≥9 h) or extremely short (<5 h) sleep durations. In addition, the proportion of subjects with dissatisfaction with sleep quality was higher in patients than controls (66.2 vs. 49.3%, p < 0.001). In multivariable conditional logistic regression analysis, long sleep duration (OR: 11.076, 95% CI: 1.819-67.446, p = 0.009) and dissatisfaction with sleep quality (OR: 2.116, 95% CI: 1.168-3.833, p = 0.013) were independently associated with risk of ischemic stroke.

CONCLUSIONS

Long sleep duration and dissatisfaction with sleep quality may be associated with increased risk of ischemic stroke in young adults. Improving sleep habit or quality could be important for reducing the risk of ischemic stroke.

The independent and combined association of napping and night sleep duration with stroke in Chinese rural adults

BACKGROUND

Inappropriate sleep duration is a potential cause of stroke. But the effect of napping on stroke risk remains controversial and the interaction between night sleep and napping duration remains unclear. The objective of this study was to examine the independent and combined effects of napping and nocturnal sleep duration on stroke.

METHODS

Subjects were derived from a rural cohort study in Henan. The Pittsburgh Sleep Quality Index (PSQI) was applied to identify nap duration and nocturnal sleep duration. Binary logistic regression was employed to indicate the dose-response relationships between naps, nocturnal sleep, total 24-h sleep duration, and stroke.

RESULTS

Among the 37,341 participants (14,485 men), 2600 suffered from a stroke. The odds ratios (ORs) and 95% confidence level (CI) for stroke in the fully adjusted model were 1.37 (1.13-1.65) for men nappers compared to non-nappers. Compared to 7-8 h of sleep per day, night sleep durations < 6 h and ≥ 9 h and 24-h sleep duration ≥ 10 h were linked to increased odds of stroke in men. The ORs (95%CI) were 1.34 (1.06-1.69) in nocturnal sleep duration < 6 h, 1.30 (1.06-1.59) in nocturnal sleep duration ≥ 9 h, and 1.40 (1.15-1.71) in 24-h sleep duration ≥ 10 h in men. In addition, long naps and prolonged nocturnal sleep duration have a joint effect on stroke in the fully adjusted model.

CONCLUSION

The napping duration and nocturnal sleep duration have independently and jointly effects on stroke in rural populations. More research is required to explore the underlying mechanisms for this relationship.

CLINICAL TRIAL REGISTRATION

The Henan Rural Cohort Study has been registered on the Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699) ( http://www.chictr.org.cn/showproj.aspx?proj=11375 ).

Association of sleep duration and napping with stroke mortality in older Chinese: A 14-year prospective cohort study of the Guangzhou Biobank Cohort study

STUDY OBJECTIVE

Evidence regarding the association of short sleep duration and napping with stroke remains limited and controversial. We examined the association of sleep duration and napping with risk of stroke mortality in an older Chinese cohort.

METHODS

Sleep duration and daytime napping were assessed by face-to-face interview during 2003-2008. Information of causes of death until April 30, 2021 was collected via record linkage with the Death Registry. Cox regression was used to calculate the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Of 27,254 participants aged average 62.0 (standard deviation = 7.1) years, 818 stroke deaths occurred within 388,798 person-years (mean = 14.3 years) of follow-up. A U-shaped relation between sleep duration and risk of stroke mortality was observed. Participants with short (≤5 h/day) or long sleep duration (≥9 h/day) showed higher risks of total stroke mortality, with adjusted HRs (95% CIs) being 1.27 (1.01-1.59) and 1.37 (1.07-1.75), respectively. However, non-significant association of short or long sleep duration with hemorrhagic or ischemic stroke mortality was found. The associations of short and long sleep duration with total stroke mortality were more pronounced in those with hypertension (P for interaction with hypertension = 0.01), with HRs (95% CIs) being 1.37 (1.04-1.82) and 1.77 (1.33-2.36), respectively. No association between napping and risk of stroke mortality was found.

CONCLUSIONS

Both short and long sleep duration, but not daytime napping, were associated with higher risk of stroke mortality. Public health messages to encourage good sleep hygiene may be important, especially for people with hypertension.

Wake-up ischemic stroke associated with short sleep duration and sleep behavior: A stratified analysis according to risk of obstructive sleep apnea

OBJECTIVE

Wake-up stroke (WUS) is an ischemic stroke occurring during nocturnal sleep with neurological deficits observed upon awakening. Our study aimed to investigate the association between WUS, sleep curtailment, and sleep behavior according to the obstructive sleep apnea (OSA) risk in patients with acute ischemic stroke.

METHODS

This single-centered, retrospective study included hospitalized subjects with acute ischemic stroke occurring within 30 days. A total of 250 participants were classified as WUS or not and enquired about their sleep habits concerning sleep time on weekdays and weekends, demographic factors, and assessed comorbid medical conditions. Weekend catch-up sleep (CUS) was defined as the extension of sleep duration during weekends. The average weekly sleep duration and chronotype were assessed. The association between WUS and sleep factors was analyzed.

RESULTS

WUS was observed in 70 patients (28.0%) with acute ischemic stroke. There were no significant differences in the demographic and stroke-related variables between the WUS and non-WUS (NWUS) groups. Upon stratified analysis based on risk of OSA, average weekly sleep duration (odds ratio, [OR] = 0.60, 95% confidence interval, [CI] = 0.41-0.89; p = 0.011), the presence of weekend CUS (OR = 0.07, 95% CI = 0.01-0.97; p = 0.047), and chronotype (OR = 0.62, 95% CI = 0.39-0.98; p = 0.041) were independently associated with WUS in low-risk group with OSA, but not in the high-risk group.

CONCLUSIONS

Short sleep duration and lack of compensation are significantly associated with WUS in low-risk OSA group. Insufficient sleep and sleep behaviors could play a different role in causing ischemic stroke during sleep when patients are stratified by their risk of sleep apnea.

Sudden gamer death: non-violent death cases linked to playing video games

BACKGROUND AND AIMS

Internet gaming disorder (IGD) is an emerging problem. Rarely, media reports about people, who have died during playing video games, but thus far no systematic, scientific study is available about the topic. We investigated such cases, looking for common characteristics, connection between gaming and death, and the possible reasons leading to death.

METHODS

Cases were collected through internet search with general keywords, with ones specific to identified cases, and by working along cross references.

RESULTS

24 cases were found: one from 1982, the others between 2002 and 2021. Twenty-three of the victims were male, age ranged from 11 to 40 years. More than half of the cases originated from Southeast Asia, and 12 deaths happened in internet cafes. Gamers played action-rich multiplayer games. In 18 cases the gaming session before death was extremely long (around a day or even several days) with minimal rest. The cause of death was pulmonary embolism in 5 cases, cerebral hemorrhage in 2 cases, most of the rest was presumably due to fatal cardiac arrhythmia.

DISCUSSION

Long sedentary position and dehydration may precipitate thromboembolism, acute blood pressure elevation during gaming may promote cerebral hemorrhage, and several factors (including acute and chronic sleep deprivation, exhaustion, stress) can lead to acute autonomic dysfunction and fatal arrhythmia.

CONCLUSION

Incidence of non-violent death cases linked to playing video games is presumably very low. It mostly occurs in young males and it is often characterized by extremely long gaming time.

Sleep Disturbances in Neurological Disease: A Target for Intervention

Sleep is a biological function required for neurological and general health, but a significant and under-recognized proportion of the population has disturbed sleep. Here, we briefly overview the biology of sleep, sleep requirements over the lifespan, and common sleep disorders. We then turn our attention to five neurological diseases that significantly contribute to global disease burden and neurology practice makeup: epilepsy, headache, ischemic stroke, Parkinson's disease, and Alzheimer's disease. For each disease, we review evidence that sleep disturbances contribute to disease risk and severity and discuss existing data that addressing sleep disturbances may have disease-modifying effects. We provide recommendations derived from the literature and existing clinical guidelines to facilitate the evaluation and management of sleep disturbances within the context of each neurological disease. Finally, we synthesize identified needs and commonalities into future directions for the field and practical sleep-related recommendations for physicians caring for patients at risk for or currently suffering from neurological disease.

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

Background

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

Study objective

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

Methods

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

Results

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

Conclusion

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

Sleep duration, daytime napping, and risk of incident stroke: Nuances by metabolic syndrome from the China health and retirement longitudinal study

Background and purpose

The relationship between sleep duration and stroke are inconclusive in China, especially in those individuals with metabolic syndrome. We aimed to investigate the association between sleep duration and incident stroke in participants with metabolic syndrome or its specific components in China.

Materials and methods

Data were taken from the 2011 and 2015 waves of China Health and Retirement Longitudinal Study (CHARLS). Habitual sleep duration (≤6, 6∼8 [reference], >8 h), daytime napping (0, 1∼60 [reference], and >60 min) were determined by self-reported questionnaires. Metabolic syndrome was defined by blood assessment and biomarkers combined with self-reported doctors' diagnosis. Incident stroke was determined by reported stroke from 2011 to 2015 wave. Cross-sectional and longitudinal associations between sleep and (incident) stroke at baseline and 4-year follow-up period were tested among the population with metabolic syndrome and its components.

Results

A U-shaped relationship was observed between sleep duration and stroke in cross-sectional analysis. Sleep ≤ 6 h/night had a greater risk of incident stroke (hazard ratio [HR] 1.65; 95% confidence interval [CI] 1.04-2.61) compared with sleep 6∼8 h/night. And the HR of stroke was 1.62 (95%CI, 1.03-2.53) for sleep < 7 h/day compared to 7∼9 h/day. These associations were more evident in the female and individuals aged 45-65 years. Furthermore, the effect of short sleep duration on incident stroke was different in each component of metabolic syndrome, which was more pronounced in participants with elevated blood pressure. And a significant joint effect of sleeping ≤ 6 h/night and no napping on risk of stroke was observed (HR 1.82, 95%CI 1.06-3.12).

Conclusion

Short sleep duration was an independent risk factor for incident stroke, especially among females, individuals aged 45-65 years, or those with some components of metabolic syndrome, such as hypertension. Napping could buffer the risk of short sleep duration on incident stroke.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

Background

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

Methods

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

Results

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

Conclusions

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

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

Sleep duration and health outcomes: an umbrella review

PURPOSE

To collect existing evidence on the relationship between sleep duration and health outcomes.

METHODS

A thorough search was conducted in PubMed, Web of Science, Embase, and the Cochrane Database of Systematic Reviews from inception to January, 2021. Meta-analyses of observational and interventional studies were eligible if they examined the associations between sleep duration and human health.

RESULTS

In total, this umbrella review identified 69 meta-analyses with 11 outcomes for cancers and 30 outcomes for non-cancer conditions. Inappropriate sleep durations may significantly elevate the risk for cardiovascular disease (CVD), cognitive decline, coronary heart disease (CHD), depression, falls, frailty, lung cancer, metabolic syndrome (MS), and stroke. Dose-response analysis revealed that a 1-h reduction per 24 hours is associated with an increased risk by 3-11% of all-cause mortality, CHD, osteoporosis, stroke, and T2DM among short sleepers. Conversely, a 1-h increment in long sleepers is associated with a 7-17% higher risk of stroke mortality, CHD, stroke, and T2DM in adults.

CONCLUSION

Inappropriate sleep duration is a risk factor for developing non-cancer conditions. Decreasing and increasing sleep hours towards extreme sleep durations are associated with poor health outcomes.

Narrative review of sleep and stroke

Sleep disorders, such as sleep-disordered breathing (SDB), insomnia or restless legs syndrome (RLS), are common in the general population and after stroke. In some cases, sleep disturbances are pre-existing, but can also appear de novo as a direct consequence of brain damage or due to stroke-related complications. Furthermore, some sleep conditions may act as a risk factor of stroke. This review explores the available evidence of the two-way relationship between sleep and stroke. Cardiovascular physiological changes during sleep are described, as well as the evidence on the relationship between stroke and sleep duration, SDB, RLS, insomnia, excessive daytime sleepiness (EDS), and circadian rhythm alterations. Potential changes on sleep architecture, and the links that may exist between sleep and functional outcomes after stroke are also discussed. Importantly, sleep-related disturbances may be associated with worse stroke recovery outcomes and increased cerebrovascular morbidity. It is therefore relevant that the bidirectional association between stroke and sleep is taken into consideration by clinicians taking care of these patients. Future research may focus on this mutual relationship for a better understanding of the impact of stroke on sleep, the importance of sleep in stroke incidence and recovery, and have further evidence on treatment strategies that may improve functional outcome after stroke.

Sleep Apnea and Heart

Scientific investigations in the past few decades have supported the important role of sleep in various domains of health. Sleep apnea is a highly prevalent yet underdiagnosed sleep disorder representing a valid cardiovascular risk factor, particularly for hypertension. While several studies have demonstrated the benefits of sleep apnea treatment on subclinical cardiovascular measures, there is a paucity of studies proving reduction of cardiovascular events and mortality. Sufficient and high-quality sleep is also important in the maintenance of cardiovascular health. Future investigations should focus on improving identification of patients at greatest risk of adverse cardiovascular s sequalae of sleep apnea and testing the therapeutic benefit of sleep apnea treatment in this vulnerable group.

Effect of hypertension status on the association between sleep duration and stroke among middle-aged and elderly population

We aimed to examine whether hypertension status modified the association between sleep duration and stroke among middle-aged and elderly population. This cross-sectional study included 10 516 participants aged ≥45 years from the China Hypertension Survey study. Sleep duration and history of stroke were assessed by questionnaires. Multivariate logistic regression analyses, a generalized additive model (GAM) and smooth curve fitting (penalized spline method) and a two-piecewise logistic regression models were performed to evaluate the association between sleep duration and stroke in different status of hypertension. 95% confidence interval (CI) for turning point was obtained by bootstrapping. Multiple logistic analyses showed that per 1 hour increase in sleep duration was associated with a 37% increased prevalence of stroke among participants without hypertension and associated with a 8% increased prevalence of stroke among hypertensive participants (without hypertension: odds ratio [OR] = 1.37, 95% CI 1.09-1.71; with hypertension: OR = 1.08, 95% CI 0.95-1.21; P_Interaction  = .029). The fully adjusted smooth curves presented a linear association between sleep duration and stroke among participants without hypertension, but a threshold, nonlinear association among hypertensive participants. The turning point for the curve was found at a sleep duration of 8 (95% CI 5-9) h among hypertensive patients. The ORs (95% CIs) for stroke were 0.92 (0.79, 1.06) and 1.60 (1.23, 2.08) to the left and right of the turning point, respectively. In conclusion, we found a linear association between sleep duration and stroke among middle-aged and elderly participants without hypertension, but a threshold, nonlinear association among hypertensive participants.

A Dose-Response Relationship Between Sleep Duration and Stroke According to Nonhealth Status in Central China: A Population-based Epidemiology Survey

PURPOSE

The aim was to investigate the relationship between sleep duration and stroke according to nonhealth status among adults in Central China.

METHODS

A total of 18,670 participants were selected by stratified multistage random sampling method in Henan province during 2013-2015. Restricted cubic splines and logistic regression were used to calculate the association between sleep duration and stroke.

RESULTS

Sleep duration showing a J-shaped dose-response association with risk of stroke among the Chinese adults in the study. The respective percentages of stroke were 6.2%, 5.6%, 3.5%, 4.5%, 5.6%, and 9.2% for those whose sleep duration less than 6 h/day, 6∼7 h/day, 7∼8 h/day, 8∼9 h/day, 9∼10 h/day, and more than or equal to 10 h/day. Compared with sleep duration of 7∼8 h/day, the risk of stroke increased by 37% (95% confidence interval [CI]: 8%, 73%) and 63% (95% CI: 30%, 104%) for those whose sleep duration were 9∼10 h/day and more than or equal to 10 h/day. The correlations between sleep durations and stroke seemed to be stronger in men than women. Stroke was associated with shorter sleep duration in ageing 60-88 years, instead of 18-59 years. The correlation between sleep duration and stroke was statistically significant at lower education level. Furthermore, the risk of stroke was slightly higher in urban residents than rural residents.

CONCLUSIONS

In summary, a J-shaped dose-response association between sleep duration and stroke was found among the adults in Central China. Furthermore, people who were male, older, less educated and living in urban areas had a higher risk of stroke.

Association between total sleep time and all cancer mortality: non-linear dose-response meta-analysis of cohort studies

OBJECTIVE

Appropriate total sleep time is reported to be associated with several important health outcomes. However, the relationship between total sleep time and all cancer mortality is not well defined because of inconsistent results from published studies, and no dose-response meta-analysis was performed to evaluate the exact dose-response relationship.

METHODS

We conducted a literature search of PubMed and Web of Science to identify all relevant epidemiological studies published before August 9, 2018. We performed categorical and non-linear dose-response meta-analyses to quantify the association between total sleep time and all cancer mortality.

RESULTS

Finally, we included 14 cohort studies in the present meta-analyses enrolling 866,877 participants with 43,021 cancer deaths. We found that total sleep time less than seven hours was not significantly associated with increased risk of all cancer mortality [relative risk (RR) = 1.02; 95% confidence interval (CI) = 0.99-1.05]. However, four to five hours total sleep time was related to an 8% increased risk of all cancer mortality (RR = 1.08; 95% CI = 1.02-1.13) in dose-response meta-analysis. Furthermore, long total sleep time (≥8 hours) was weakly associated with all cancer mortality (RR = 1.05; 95% CI = 1.02-1.08). However, the increment in total sleep time longer than nine hours was notably associated with an increased risk of cancer mortality.

CONCLUSION

The current meta-analysis provides evidence of a positive association between total sleep time of four to five hours and total sleep time longer than eight hours with the risk of all cancer mortality among the general population. Additional studies are needed to establish causality.

Adherence to the Mediterranean diet and risk of stroke and stroke subtypes

Several meta-analyses including a small number of cohorts showed inverse associations between the Mediterranean Diet (MedDiet) and risk of stroke. However, it remains unclear whether such a relation varies by region of the study population or by major subtypes of stroke. We searched PubMed and EMBASE databases for relevant studies and we further included unpublished results from the Singapore Chinese Health Study (N = 57,078) and the Seguimiento Universidad de Navarra (SUN) study (N = 12,670). We used a random-effects model to calculate summary relative risk (RR) with 95% confidence intervals (CI) of stroke for each 4-point increment of the MedDiet score, roughly corresponding to the difference between extreme quintiles of the MedDiet score among participants of the included studies. The final analyses included 20 prospective cohort studies involving 682,149 participants and 16,739 stroke cases. The summary RRs for each 4-point increment of the MedDiet score were 0.84 (95% CI 0.81-0.88; I² = 11.5%) for all combined, 0.76 (95% CI 0.65-0.89) for studies in Mediterranean populations and 0.86 (95% CI 0.83-0.89) for those in non-Mediterranean populations. Lower risk of stroke associated with higher MedDiet score also was observed in the analyses stratified by study population and methodological characteristics including study risk of bias, version of the MedDiet index, and definition of moderate alcohol consumption. The MedDiet was similarly associated with lower risk of ischemic stroke (RR 0.86, 95% CI 0.81-0.91; nine studies) and hemorrhagic stroke (RR 0.83, 95% CI 0.74-0.93; eight studies). Our meta-analysis suggests that adhering to the Mediterranean diet was associated with lower risk of stroke in both Mediterranean and non-Mediterranean populations, and for both ischemic stroke and hemorrhagic stroke risk.

Sleep duration and risk of end-stage renal disease: the Singapore Chinese Health Study

OBJECTIVES

Although epidemiological evidence suggests that short sleep duration may affect renal function, the influence of long sleep and risk of end-stage renal disease (ESRD) is unclear. We examined the association between sleep duration and risk of ESRD.

METHODS

We investigated sleep duration and ESRD risk in the Singapore Chinese Health Study, a prospective population-based cohort of 63,257 Chinese in Singapore, who were aged 45-74 years at recruitment (1993-1998). Information on daily sleep duration (including naps), diet, medical history and other lifestyle factors was collected at recruitment from in-person interviews. ESRD cases were identified via linkage with the nationwide Singapore Renal Registry through year 2014. We used the Cox proportional hazards regression method to estimate hazard ratio (HR) and 95% confidence interval (CI) of ESRD in relation to sleep duration.

RESULTS

After an average 16.8 years of follow-up, 1143 (1.81%) ESRD cases were documented. Sleep duration had a U-shaped association with risk of ESRD (P for quadratic trend < 0.001). Compared with participants with 7 h/day of sleep, the multivariable adjusted HR (95% CI) of ESRD was 1.43 (1.18-1.74) for short sleep (≤5 h/day) and 1.28 (1.03-1.60) for long sleep duration (≥9 h/day). The increased risk was stronger in participants with more than 10 years of follow-up compared to those with shorter follow-up time, especially for long sleep (P for interaction = 0.003).

CONCLUSIONS

Our findings demonstrated that both short and long sleep durations were associated with a higher risk of ESRD in this Asian population.

Self-Reported Sleep Duration and Quality and Cardiovascular Disease and Mortality: A Dose-Response Meta-Analysis

Background There is growing evidence that sleep duration and quality may be associated with cardiovascular harm and mortality. Methods and Results We conducted a systematic review, meta-analysis, and spline analysis of prospective cohort studies that evaluate the association between sleep duration and quality and cardiovascular outcomes. We searched MEDLINE and EMBASE for these studies and extracted data from identified studies. We utilized linear and nonlinear dose-response meta-analysis models and used DerSimonian-Laird random-effects meta-analysis models of risk ratios, with inverse variance weighting, and the I2 statistic to quantify heterogeneity. Seventy-four studies including 3 340 684 participants with 242 240 deaths among 2 564 029 participants who reported death events were reviewed. Findings were broadly similar across both linear and nonlinear dose-response models in 30 studies with >1 000 000 participants, and we report results from the linear model. Self-reported duration of sleep >8 hours was associated with a moderate increased risk of all-cause mortality, with risk ratio , 1.14 (1.05-1.25) for 9 hours, risk ratio, 1.30 (1.19-1.42) for 10 hours, and risk ratio, 1.47 (1.33-1.64) for 11 hours. No significant difference was identified for periods of self-reported sleep <7 hours, whereas similar patterns were observed for stroke and cardiovascular disease mortality. Subjective poor sleep quality was associated with coronary heart disease (risk ratio , 1.44; 95% confidence interval, 1.09-1.90), but no difference in mortality and other outcomes. Conclusions Divergence from the recommended 7 to 8 hours of sleep is associated with a higher risk of mortality and cardiovascular events. Longer duration of sleep may be more associated with adverse outcomes compared with shorter sleep durations.

Sleep disorders and the risk of stroke

INTRODUCTION

Stroke is a major cause of disability and death in the United States and across the world, and the incidence and prevalence of stroke are expected to rise significantly due to an aging population. Obstructive sleep apnea, an established independent risk factor for stroke, is a highly prevalent disease that is estimated to double the risk of stroke. It remains uncertain whether non-apnea sleep disorders increase the risk of stroke. Areas covered: This paper reviews the literature describing the association between incident stroke and sleep apnea, rapid eye movement sleep behavior disorder, restless legs syndrome, periodic limb movements of sleep, insomnia, and shift work. Expert commentary: Trials of continuous positive airway pressure for stroke prevention in sleep apnea patients have been largely disappointing, but additional trials that target populations not yet optimally studied are needed. Self-reported short and long sleep duration may be associated with incident stroke. However, abnormal sleep duration may be a marker of chronic disease, which may itself be associated with incident stroke. The relationship between non-apnea sleep disorders and incident stroke deserves further attention. Identification of specific non-apnea sleep disorders or sleep problems that convey an increased risk for stroke may provide novel targets for stroke prevention.

Insomnia is associated with increased mortality in patients with first-ever stroke: a 6-year follow-up in a Chinese cohort study

Objective

Insomnia is a highly prevalent disorder among patients suffering from stroke. The association between insomnia and stroke mortality is less studied, particularly using the latest diagnostic criteria. The current study examined the relationship between insomnia and mortality among patients with first-evonal hazard models were used to calculate HRs for stroke er stroke in China.

Methods

Patients with acute cerebrovascular diseases (stroke) were recruited from 56 hospitals in mainland China. Insomnia was defined as difficulty falling asleep, or difficulty staying asleep or waking up early, for at least two consecutive visits. Demographic data, medical history and clinical data were collected. Four follow-up visits occurred within the first year after stroke, and the last follow-up call was conducted 6 years later. Cox proportional hazard models were used to calculate HRs for stroke mortality.

Results

Insomnia was reported by 38.4% (489/1273) of patients at baseline. During the 6 years of follow-up, after adjusting for all confounders, insomnia was found to be associated with increased mortality (HR=1.66, 95% CI 1.10 to 2.48). Old age (HR=1.08, 95% CI 1.06 to 1.10), stroke recurrence in the first year of follow-up (HR=2.53, 95% CI 1.48 to 4.31) and stroke survivors with hypertension (HR=1.62, 95% CI 1.04 to 2.53) had substantially higher risk of mortality.

Conclusions

Besides old age, stroke recurrence in the first year of follow-up and hypertension, insomnia is associated with increased risk of mortality in patients with first-ever stroke in China. More studies about prompt and efficient interventions for insomnia are expected in the future.

Trial registration number

rctn62169508.

Functional segregation loss over time is moderated by APOE genotype in healthy elderly

We investigated the influence of the apolipoprotein E-ɛ4 allele (APOE-ɛ4) on longitudinal age-related changes in brain functional connectivity (FC) and cognition, in view of mixed cross-sectional findings. One hundred and twenty-two healthy older adults (aged 58-79; 25 APOE-ɛ4 carriers) underwent task-free fMRI scans at baseline. Seventy-eight (16 carriers) had at least one follow-up (every 2 years). Changes in intra- and internetwork FCs among the default mode (DMN), executive control (ECN), and salience (SN) networks, as well as cognition, were quantified using linear mixed models. Cross-sectionally, APOE-ɛ4 carriers had lower functional connectivity between the ECN and SN than noncarriers. Carriers also showed a stronger age-dependent decrease in visuospatial memory performance. Longitudinally, carriers had steeper increase in inter-ECN-DMN FC, indicating loss of functional segregation. The longitudinal change in processing speed performance was not moderated by APOE-ɛ4 genotype, but the brain-cognition association was. In younger elderly, faster loss of segregation was correlated with greater decline in processing speed regardless of genotype. In older elderly, such relation remained for noncarriers but reversed for carriers. APOE-ɛ4 may alter aging by accelerating the change in segregation between high-level cognitive systems. Its modulation on the longitudinal brain-cognition relationship was age-dependent.

Sleep lengthening in late adulthood signals increased risk of mortality

Study Objectives

Epidemiological evidence indicates that both short and long sleep at midlife increase mortality risk, but few studies have examined how change in sleep duration between midlife and later life affects this risk. We examined the association between change in sleep duration and mortality risk.

Methods

The Singapore Chinese Health Study is a prospective cohort of 63257 Chinese in Singapore aged 45-74 years at recruitment (1993-1998). Self-reported sleep duration was collected from 39523 participants who completed both baseline (mean age 54.8 years) and follow-up II (mean age 67.9 years; 2006-2010) interviews, which were on average 12.7 years apart. Mortality data were obtained via linkage with national death registry up to December 31, 2015.

Results

Compared with participants who reported sleeping the recommended duration (7 hr) at both interviews, those with persistently short sleep (≤5 hr) had increased risk of all-cause mortality (hazard ratio [HR] 1.27, 95% confidence interval [CI] 1.06-1.53). Similarly, those with persistently long sleep (≥9 hr) had increased risk of all-cause (HR 1.47, 95% CI 1.24-1.73) and cardiovascular (HR 1.40, 95% CI 1.04-1.89) mortality. The proportion of long-sleepers increased with aging (6%-23.7%). Progression to long sleep from short (HR 1.50, 95% CI 1.24-1.81) or recommended (HR 1.43, 95% CI 1.25-1.64) duration was associated with increased all-cause mortality, especially for cardiovascular mortality. Change in sleep duration was not linked to cancer mortality.

Conclusions

Persistent short or long sleep or increasing sleep duration in late adulthood was associated with increased risk of all-cause mortality, especially from cardiovascular causes.

Verification of effect of sleep health education program in workplace: a quasi-randomized controlled trial

Short sleep duration is a serious problem that not only enhances the risk of various mental and physical disorders, but also affects the productivity in the workplace. However, in terms of studies focused on workers, there are few reports that evaluated sleeping conditions in an objective way. The purpose of this study is to implement sleep health education in the workplace in terms of primary prevention of mental health disorder and then to investigate the subjective and objective effectiveness of the education using self-administered questionnaires (sleep duration, ESS, AIS, PHQ-9, SF-8) and an activity monitor (MTN-210). Study design is a quasi-randomized controlled trial. Sleep health education was provided through three 50-min lectures (total 150 min) as a single cycle for five months in the Intervention group. We obtained baseline data and then six months later. The study analyzed 70 subjects (36 Intervention group, 34 Control group). The weekday sleep duration for the Control group decreased by 12.9 min, whereas that of the Intervention group increased by 14.3 min (difference of 27.2 min), resulting in a significantly increase in score for the Intervention group. The present study suggests that sleep health education may be beneficial for good sleep habits in workers.

Sleep Disturbances as a Risk Factor for Stroke

Sleep, a vital process of human being, is carefully orchestrated by the brain and consists of cyclic transitions between rapid eye movement (REM) and non-REM (NREM) sleep. Autonomic tranquility during NREM sleep is characterized by vagal dominance and stable breathing, providing an opportunity for the cardiovascular-neural axis to restore homeostasis, in response to use, distress or fatigue inflicted during wakefulness. Abrupt irregular swings in sympathovagal balance during REM sleep act as phasic loads on the resting cardiovascular system. Any causes of sleep curtailment or fragmentation such as sleep restriction, sleep apnea, insomnia, periodic limb movements during sleep, and shift work, not only impair cardiovascular restoration but also impose a stress on the cardiovascular system. Sleep disturbances have been reported to play a role in the development of stroke and other cardiovascular disorders. This review aims to provide updated information on the role of abnormal sleep in the development of stroke, to discuss the implications of recent research findings, and to help both stroke clinicians and researchers understand the importance of identification and management of sleep pathology for stroke prevention and care.

Relationship of Sleep Duration With All-Cause Mortality and Cardiovascular Events: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

Background

Effects of extreme sleep duration on risk of mortality and cardiovascular outcomes remain controversial. We aimed to quantify the dose‐response relationships of sleep duration with risk of all‐cause mortality, total cardiovascular disease, coronary heart disease, and stroke.

Methods and Results

PubMed and Embase were systematically searched for prospective cohort studies published before December 1, 2016, that examined the associations between sleep duration and at least 1 of the 4 outcomes in generally healthy populations. U‐shaped associations were indicated between sleep duration and risk of all outcomes, with the lowest risk observed for ≈7‐hour sleep duration per day, which was varied little by sex. For all‐cause mortality, when sleep duration was <7 hours per day, the pooled relative risk (RR) was 1.06 (95% CI, 1.04–1.07) per 1‐hour reduction; when sleep duration was >7 hours per day, the pooled RR was 1.13 (95% CI, 1.11–1.15) per 1‐hour increment. For total cardiovascular disease, the pooled RR was 1.06 (95% CI, 1.03–1.08) per 1‐hour reduction and 1.12 (95% CI, 1.08–1.16) per 1‐hour increment of sleep duration. For coronary heart disease, the pooled RR was 1.07 (95% CI, 1.03–1.12) per 1‐hour reduction and 1.05 (95% CI, 1.00–1.10) per 1‐hour increment of sleep duration. For stroke, the pooled RR was 1.05 (95% CI, 1.01–1.09) per 1‐hour reduction and 1.18 (95% CI, 1.14–1.21) per 1‐hour increment of sleep duration.

Conclusions

Our findings indicate that both short and long sleep duration is associated with an increased risk of all‐cause mortality and cardiovascular events.

Inhibition of SNK-SPAR signaling pathway promotes the restoration of motor function in a rat model of ischemic stroke

This study aimed to investigate the effects of SPAR signaling pathway on the restoration of motor function in ischemic stroke (IS). Sprague-Dawley male rats were separated into the control and sham groups, as well as the group for middle cerebral artery occlusion (MCAO) model establishment. Successfully established rat ischemic models were randomly divided into model, SNK^MCAO-del and pcDNA3.1-SNK groups. The evaluation of motor function among the rats in each group was assessed using a balance beam, a screen test and the Garcia scoring method. CatWalk gait analysis was employed to evaluate the effect of the SNK signaling pathway on rat motor function. Triphenyltetrazolium chloride (TTC) and TUNEL staining were techniques were utilized for cerebral infarction (CI) area as well for hippocampal neuron apoptosis. The quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting methods were performed to detect mRNA and protein expressions of SNK and SPAR. When compared with the model group, the SNK^MCAO-del group displayed decreased motor function score and CI area, while contrasting results were observed in the pcDNA3.1-SNK group. According to the results obtained from the CatWalk gait analysis, the SNK^MCAO-del group showed a clear improvement compared to the model group whereas the pcDNA3.1-SNK group exhibited poorer results than the model group in the objective parameters of the study, such as movement, speed, running duration, print area, maximal contact area, maximal, mean intensity, and stride length. These findings suggested that SNK gene silencing promotes motor function by inhibiting the SNK-SPAR signaling pathway in rats with ischemic stroke.

The risk of occupational injury increased according to severity of noise exposure after controlling for occupational environment status in Korea

Objectives:

The aim of this study was to examine the relationship between noise exposure and risk of occupational injury.

Materials and Methods:

Korean National Health and Nutrition Examination Survey was used for the current study. Self-report questionnaires were used to investigate occupational injury and exposure to noise, chemicals, and machines and equipments.

Results:

In separate analyses for occupation and occupational hazard, the proportion of occupational injuries increased according to severity of noise exposure (all P < 0.05). Compared to the non-exposure group, the respective odds ratio (95% confidence intervals) for occupational injury was 1.39 (1.07–1.80) and 1.67 (1.13–2.46) in the mild and severe noise exposure groups, after controlling for age, gender, sleep hours, work schedule (shift work), and exposure status to hazardous chemicals and hazardous machines and equipments.

Conclusions:

The current study highlights the association between noise exposure and risk of occupational injury. Furthermore, risk of occupational injury increased according to severity of noise exposure.

Sex and age differences in the associations between sleep behaviors and all-cause mortality in older adults: results from the National Health and Nutrition Examination Surveys

OBJECTIVE

Our aim was to examine sex- and age-specific relationships of sleep behaviors with all-cause mortality rates.

METHODS

A retrospective cohort study was conducted among 5288 adults (≥50 years) from the 2005-2008 National Health and Nutrition Examination Surveys who were followed-up for 54.9 ± 1.2 months. Sleep duration was categorized as < 7 h, 7-8 h and >8 h. Two sleep quality indices were generated through factor analyses. 'Help-seeking behavior for sleep problems' and 'diagnosis with sleep disorders' were defined as yes/no questions. Sociodemographic covariates-adjusted Cox regression models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A positive relationship was observed between long sleep and all-cause mortality rate in the overall sample (HR = 1.90, 95% CI: 1.38, 2.60), among males (HR = 1.48, 95% CI: 1.05, 2.09), females (HR = 2.32, 95% CI: 1.48, 3.61) and elderly (≥65 years) people (HR = 1.80, 95% CI: 1.30, 2.50). 'Sleepiness/sleep disturbance' (Factor I) and all-cause mortality rate were positively associated among males (HR = 1.22, 95% CI: 1.03, 1.45), whereas 'poor sleep-related daytime dysfunction' (Factor II) and all-cause mortality (HR = 0.75, 95% CI: 0.62, 0.91) were negatively associated among elderly people.

CONCLUSIONS

Sex- and age-specific relationships were observed between all-cause mortality rate and specific sleep behaviors among older adults.

Sleep duration and risk of stroke: a dose-response meta-analysis of prospective cohort studies

OBJECTIVES

Suboptimal sleep duration has been considered to increase the risk of stroke incidence. Thus we aimed to conduct a dose-response meta-analysis to examine the association between sleep duration and stroke incidence.

METHODS

We searched PubMed, Web of science and the Cochrane Library to identify all prospective studies evaluating the association of sleep duration and nonfatal and/or fatal stroke incidence. Then, restricted cubic spline functions and piecewise linear functions were used to evaluate the nonlinear and linear dose-response association between them.

RESULTS

We included a total of 16 prospective studies enrolling 528,653 participants with 12,193 stroke events. Nonlinear dose-response meta-analysis showed a J-shaped association between sleep duration and total stroke with the lowest risk observed with sleeping for 7 h. Considering people sleeping for 7 h as reference, long sleepers had a higher predicted risk of total stroke than short sleepers [the pooled risk ratios (95% confidence intervals): 4 h: 1.17 (0.99-1.38); 5 h: 1.17 (1.00-1.37); 6 h: 1.10 (1.00-1.21); 8 h: 1.17 (1.07-1.28); 9 h: 1.45 (1.23-1.70); 10 h: 1.64 (1.4-1.92); p_nonlinearity<0.001]. Short sleep durations were only significantly associated with nonfatal stroke and with total stroke in the subgroups of structured interview and non-Asian countries. Additionally, we found a slightly decreased risk of ischemic stroke among short sleepers. For piecewise linear trends, compared to 7 h, every 1-h increment of sleep duration led to an increase of 13% [the pooled risk ratios (95% confidence intervals): 1.13 (1.07-1.20); p < 0.001] in risk of total stroke.

CONCLUSION

Both in nonlinear and piecewise linear dose-response meta-analyses, long sleep duration significantly increased the risk of stroke incidence.

Sleep Disturbances among Older Adults in the United States, 2002-2012: Nationwide Inpatient Rates, Predictors, and Outcomes

Objective/Background: We examined the rates, predictors, and outcomes [mortality risk (MR), length of stay (LOS), and total charges (TC)] of sleep disturbances in older hospitalized patients.

Patients/Methods: Using the U.S. Nationwide Inpatient Sample database (2002–2012), older patients (≥60 years) were selected and rates of insomnia, obstructive sleep apnea (OSA) and other sleep disturbances (OSD) were estimated using ICD-9CM. TC, adjusted for inflation, was of primary interest, while MR and LOS were secondary outcomes. Multivariable regression analyses were conducted.

Results: Of 35,258,031 older adults, 263,865 (0.75%) had insomnia, 750,851 (2.13%) OSA and 21,814 (0.06%) OSD. Insomnia rates increased significantly (0.27% in 2002 to 1.29 in 2012, P-trend < 0.001), with a similar trend observed for OSA (1.47 in 2006 to 5.01 in 2012, P-trend < 0.001). TC (2012 $) for insomnia-related hospital admission increased over time from $22,250 in 2002 to $31,527 in 2012, and increased similarly for OSA and OSD; while LOS and MR both decreased. Women with any sleep disturbance had lower MR and TC than men, while Whites had consistently higher odds of insomnia, OSA, and OSD than older Blacks and Hispanics. Co-morbidities such as depression, cardiovascular risk factors, and neurological disorders steadily increased over time in patients with sleep disturbances.

Conclusion: TC increased over time in patients with sleep disturbances while LOS and MR decreased. Further, research should focus on identifying the mechanisms that explain the association between increasing sleep disturbance rates and expenditures within hospital settings and the potential hospital expenditures of unrecognized sleep disturbances in the elderly.

Sleep duration, daytime napping, markers of obstructive sleep apnea and stroke in a population of southern China

Sleep habits are associated with stroke in western populations, but this relation has been rarely investigated in China. Moreover, the differences among stroke subtypes remain unclear. This study aimed to explore the associations of total stroke, including ischemic and hemorrhagic type, with sleep habits of a population in southern China. We performed a case-control study in patients admitted to the hospital with first stroke and community control subjects. A total of 333 patients (n = 223, 67.0%, with ischemic stroke; n = 110, 23.0%, with hemorrhagic stroke) and 547 controls were enrolled in the study. Participants completed a structured questionnaire to identify sleep habits and other stroke risk factors. Least absolute shrinkage and selection operator (Lasso) and multiple logistic regression were performed to identify risk factors of disease. Incidence of stroke, and its subtypes, was significantly associated with snorting/gasping, snoring, sleep duration, and daytime napping. Snorting/gasping was identified as an important risk factor in the Lasso logistic regression model (Lasso' β = 0.84), and the result was proven to be robust. This study showed the association between stroke and sleep habits in the southern Chinese population and might help in better detecting important sleep-related factors for stroke risk.

Long Sleep Duration and Risk of Ischemic Stroke and Hemorrhagic Stroke: the Kailuan Prospective Study

The objective of this study was to examine the relationship between sleep duration and ischemic and hemorrhagic stroke in a community-based cohort. The current analysis included 95,023 Chinese participants who were free of stroke at the baseline survey (2006–2007). Cox proportional hazards models were used to calculate hazard ratios (HRs) and their confidence intervals (CIs) for stroke, according to sleep duration. After a mean follow-up period of 7.9 years, 3,135 participants developed stroke (2,504 ischemic stroke and 631 hemorrhagic stroke). The full adjusted hazard ratio (95% CI) of total stroke (with 6–8 hours of night sleep being considered for the reference group) for individuals reporting greater than 8 hours was 1.29 (1.01–1.64). More significant association between long sleep duration and total stroke was found in the elderly (HR, 1.47; 95% CI, 1.05–2.07). Compared with participants getting 6–8 hours of sleep, only women who reported sleeping more than 8 hours per night were associated with hemorrhagic stroke (HR, 3.58; 95% CI, 1.28–10.06). This study suggested that long sleep duration might be a potential predictor/ marker for total stroke, especially in the elderly. And long sleep duration increased the risk of hemorrhagic stroke only in women.

Influence of sleep disturbances on age at onset and long-term incidence of major cardiovascular events: the MONICA-Brianza and PAMELA cohort studies

OBJECTIVE

We examined the prospective associations of sleep disturbances and sleep duration with the long-term incidence of major cardiovascular disease (CVD) events, in a large cohort of Italian adult men.

METHODS

A total of 2277 men aged 35-74 years of age and CVD free at baseline from the MONICA-Brianza and PAMELA population-based cohorts were followed up for a median of 17 years, for first coronary heart disease (CHD) or ischemic stroke events (fatal or nonfatal; n = 293). Sleep disturbances, based on the Jenkins Sleep Questionnaire, were categorized as none/some, moderate, or severe. Sleep durations were ≤6 hours (short), seven to eight hours, and ≥9 hours (long) per night.

RESULTS

At baseline, 855 men (38%) either reported sleep disturbances or were short or long sleepers. The presence of severe sleep disturbances increased the risk of first CVD (hazard ratio [HR] = 1.80, 95% confidence interval [CI] = 1.07-3.03) and CHD events (HR = 1.97, 95% CI = 1.09-3.56), in particular from the age of 48 years onward. In comparison to men sleeping seven to eight hours, long sleepers experienced a higher CVD risk (HR = 1.56, 95% CI = 1.10-2.22), due mainly to ischemic strokes, and starting at older ages (≥60 years). A joint effect between disturbed sleep and short sleep duration on CVD and CHD events was also observed. Adjustments for physical activity and depression did not substantially modify these associations.

CONCLUSION

Severe sleep disturbances and long sleep duration were associated with specific CVD endpoints and age at onset, potentially suggesting distinct underlying mechanisms. A short questionnaire discriminating different levels of sleep disturbances and sleep duration should be routinely adopted in CVD prevention programs to identify men at increased risk for early-onset events.

Sleep Duration and the Risk of Mortality From Stroke in Japan: The Takayama Cohort Study

BACKGROUND

Few studies have assessed the associations between sleep duration and stroke subtypes. We examined whether sleep duration is associated with mortality from total stroke, ischemic stroke, and hemorrhagic stroke in a population-based cohort of Japanese men and women.

METHODS

Subjects included 12 875 men and 15 021 women aged 35 years or older in 1992, who were followed until 2008. The outcome variable was stroke death (ischemic stroke, hemorrhagic stroke, and total stroke).

RESULTS

During follow-up, 611 stroke deaths (354 from ischemic stroke, 217 from hemorrhagic stroke, and 40 from undetermined stroke) were identified. Compared with 7 h of sleep, ≥9 h of sleep was significantly associated with an increased risk of total stroke and ischemic stroke mortality after controlling for covariates. Hazard ratios (HRs) and 95% confidence intervals (CIs) were 1.51 (95% CI, 1.16-1.97) and 1.65 (95% CI, 1.16-2.35) for total stroke mortality and ischemic stroke mortality, respectively. Short sleep duration (≤6 h of sleep) was associated with a decreased risk of mortality from total stroke (HR 0.77; 95% CI, 0.59-1.01), although this association was of borderline significance (P = 0.06). The trends for total stroke and ischemic stroke mortality were also significant (P < 0.0001 and P = 0.0002, respectively). There was a significant risk reduction of hemorrhagic stroke mortality for ≤6 h of sleep as compared with 7 h of sleep (HR 0.64; 95% CI, 0.42-0.98; P for trend = 0.08). The risk reduction was pronounced for men (HR 0.31; 95% CI, 0.16-0.64).

CONCLUSIONS

Data suggest that longer sleep duration is associated with increased mortality from total and ischemic stroke. Short sleep duration may be associated with a decreased risk of mortality from hemorrhagic stroke in men.

Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society on the Recommended Amount of Sleep for a Healthy Adult: Methodology and Discussion

The American Academy of Sleep Medicine and Sleep Research Society recently released a Consensus Statement regarding the recommended amount of sleep to promote optimal health in adults. This paper describes the methodology, background literature, voting process, and voting results for the consensus statement. In addition, we address important assumptions and challenges encountered during the consensus process. Finally, we outline future directions that will advance our understanding of sleep need and place sleep duration in the broader context of sleep health.

Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society on the Recommended Amount of Sleep for a Healthy Adult: Methodology and Discussion

The American Academy of Sleep Medicine and Sleep Research Society recently released a Consensus Statement regarding the recommended amount of sleep to promote optimal health in adults. This paper describes the methodology, background literature, voting process, and voting results for the consensus statement. In addition, we address important assumptions and challenges encountered during the consensus process. Finally, we outline future directions that will advance our understanding of sleep need and place sleep duration in the broader context of sleep health.