Is there an association among sleep duration, nap, and stroke? Findings from the China Health and Retirement Longitudinal Study

Higher triglyceride‑glucose index is associated with increased risk of stroke among middle-aged and elderly Chinese: a national longitudinal study

Stroke is a severe cerebrovascular disease. This study aimed to determine the association between triglyceride‑glucose (TyG) index and stroke among middle-aged and elderly Chinese. Data was extracted from China Health and Retirement Longitudinal Study survey 2015 and survey 2018. Logistic regression, trend test and subgroup analysis were conducted to assess the association. Possible nonlinear relationships were explored with restricted cubic spline (RCS). Propensity score matching (PSM) was conducted to attenuate the effect of confounding factors. ORs of stroke was positively associated with TyG index. The ORs in RCS analysis also increased with the rising TyG, though p for non-linearity was bigger than 0.05. After PSM, the ORs in the full adjusted models were 1.28 (1.01, 1.62). TyG was suggested as an independent risk factor for stroke in the middle aged and elderly Chinese.

Association of total sleep duration variability with risk of new stroke in the middle-aged and elderly Chinese population

OBJECTIVE

To investigate the association between total sleep duration variability and stroke in the middle-aged and elderly population in China.

METHODS

Data were collected from the 2011, 2013, 2015, and 2018 surveys of the China Health and Retirement Longitudinal Study (CHARLS). A total of 3485 participants, who had not experienced a stroke until 2015 and completed the follow-up in 2018, were enrolled to analyze the relationship between total sleep duration variability and new stroke. Total sleep duration was calculated by summing self-reported nocturnal sleep duration and daytime napping. The variability was determined by calculating the standard deviation (SD) of total sleep duration across the first three waves. A binary logistic regression model was utilized to analyze this association.

RESULTS

Of the 3485 participants, 183 (5.25%) sustained a stroke event. A dose-response relationship was observed, indicating an increased stroke risk of 0.2 per unit (hours) increase in total sleep duration variability [OR (95% CI): 1.20 (1.01-1.42)]. Upon stratification by sex groups, this increased risk was significant only in men [OR (95% CI): 1.44 (1.12-1.83)].

CONCLUSION

Increased total sleep duration variability was associated with an increased risk of stroke in the middle-aged and elderly, independent of factors such as age, nocturnal sleep duration, napping habits, region of residence, hypertension, diabetes mellitus, dyslipidemia, BMI, smoking, drinking habits, and marital status. However, a more notable correlation was observed in males.

Deciphering Post-Stroke Sleep Disorders: Unveiling Neurological Mechanisms in the Realm of Brain Science

Sleep disorders are the most widespread mental disorders after stroke and hurt survivors' functional prognosis, response to restoration, and quality of life. This review will address an overview of the progress of research on the biological mechanisms associated with stroke-complicating sleep disorders. Extensive research has investigated the negative impact of stroke on sleep. However, a bidirectional association between sleep disorders and stroke exists; while stroke elevates the risk of sleep disorders, these disorders also independently contribute as a risk factor for stroke. This review aims to elucidate the mechanisms of stroke-induced sleep disorders. Possible influences were examined, including functional changes in brain regions, cerebrovascular hemodynamics, neurological deficits, sleep ion regulation, neurotransmitters, and inflammation. The results provide valuable insights into the mechanisms of stroke complicating sleep disorders.

The association between sleep deprivation and the risk of cardiovascular diseases: A systematic meta‑analysis

Globally, sleep deprivation is a concerning health issue associated with an increased risk of cardiovascular diseases (CVDs). The present study aimed to explore the association between short-term sleep and the risk of CVDs, taking into consideration sex and age groups. A comprehensive review was conducted by assembling cohort studies that are available in the PubMed, Cochrane Library, and Embase databases. Individuals with ≤5 or ≤6 h of sleep per day were considered as sleep-deprived subjects. To minimize potential bias, two reviewers thoroughly evaluated the selected articles. Relevant data were extracted, and pooled odds ratios (ORs) or relative risks (RRs) were calculated using a random-effects model. In total, 18 cohort studies involving adult subjects were included in the present analysis. The pooled results strongly indicated that sleep deprivation was associated with a greater risk of CVDs [RR: 1.09, 95% confidence interval (CI): 1.02-1.16, P=0.009]. However, when the pooled analysis was stratified by sex and age, the following results were observed: short-term sleep women (RR: 1.06, 95% CI: 0.96-1.17, P=0.27), short-term sleep men (RR: 1.07, 95% CI: 0.97-1.17, P=0.17); ≥18 years-old sleep-deprived population (RR: 1.09, 95% CI: 1.00-1.17, P=0.04), ≥40 years-old sleep-deprived population (RR: 1.09, 95% CI: 0.98-1.22, P=0.11), and subjects with co-existing diseases, such as diabetes and hyperlipidemia (RR: 1.06, 95% CI: 0.94-1.20, P=0.32). In conclusion, short-term sleep is associated with the increased risk of CVDs. Among subjects who were aged ≥18 years-old, there was a strong association with the development of CVDs compared with those who were aged ≥40 years-old. Furthermore, men were at a higher risk of CVDs than women. Adequate sleep (7-8 h per day) may play a role in improving cardiac health. The results of the present study may provide valuable support for further research in public health, highlighting the correlation between sleep deprivation and the risk of CVDs.

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.

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 ).

Does Education Influence Life-Course Depression in Middle-Aged and Elderly in China? Evidence from the China Health and Retirement Longitudinal Study (CHARLS)

Mental health problems have become a major public health problem worldwide and are more common among middle-aged and elderly people in China. Research on the effect of education on depression is limited, and whether the relationship between education and depression changes over the life course remains unclear. This study was based on the cross-sectional data of 15,767 middle-aged and elderly individuals in the 2018 tracking survey (Wave 4) of the China Health and Retirement Longitudinal Study (CHARLS) database. Multiple linear regression and bootstrap methods were developed to detect the mediating effect of education on depression. In all samples or different age groups, education was significantly positively associated with depression. Three mediators (economic level, health-related lifestyle, and cognitive level) were significantly positively associated with depression, and cognitive level had a greater effect on depression than economic level and health-related lifestyle. The total, direct, and indirect effects of the whole samples and elderly samples were significant; however, the direct effect of the middle-aged samples was insignificant, and the total and indirect effects of the three mediating pathways were all significant, that is, economic level, health-related lifestyle, and cognitive level should produce complete mediation. The multiple linear regression and bootstrap methods could successfully detect the mediating effect of education on depression. On the basis of the education, economic level, health-related lifestyle, cognitive level, and depression of middle-aged and elderly people, we established and compared the total, direct, and mediating effects of education on depression under the life course. The mediating variables should be further increased, and the measurement methods of depression should be developed to improve the credibility of the research results.

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.

Daytime napping and cardiovascular risk factors, cardiovascular disease, and mortality: A systematic review

Associations between night sleep duration and cardiovascular risk factors in adults have been well documented. However, the associations for daytime napping remain unclear. In this review, six databases were searched for eligible publications to April 8, 2022. A total of 11 articles were identified for umbrella review on the association of daytime napping with diabetes, metabolic syndrome (MetS), cardiovascular disease (CVD), and mortality in adults, 97 for systematic review on the association with CVD and several CVD risk factors. Our umbrella review showed that the associations of daytime napping with diabetes, MetS, CVD, and mortality in most meta-analyses were mainly supported by weak or suggestive evidence. Our systematic review showed that long daytime napping (≥1 h/d) was associated with higher odds of several CVD risk factors, CVD, and mortality, but no significant association was found between short daytime napping and most of the abovementioned outcomes. Our dose-response meta-analyses showed that daytime napping <30 min/d was not significantly associated with higher odds of most CVD risk factors and CVD among young and middle-aged adults. However, among older adults aged >60 years, we observed significant dose-response associations of daytime napping with higher odds of diabetes, dyslipidemia, MetS, and mortality starting from 0 min/d.

Associations between sleep duration and cardiovascular diseases: A meta-review and meta-analysis of observational and Mendelian randomization studies

The associations between sleep duration and cardiovascular diseases (CVDs) have been explored in many observational studies. However, the causality of sleep duration and many CVDs, such as coronary artery disease (CAD), heart failure (HF), and stroke, remains unclear. In this study, we conducted a systematic meta-review and meta-analysis of the results of observational and Mendelian randomization (MR) studies to examine how sleep duration impacts the risk of CVDs. We searched articles published in English and before 10 September 2021 in PubMed, Web of Science, and Embase. The articles were screened independently by two reviewers to minimize potential bias. We combined the meta-analyses of observational studies and 11 MR studies and summarized evidence of the effect of sleep duration on the risk of CAD, HF, stroke, and cardiovascular and all-cause mortality. Results showed that (a) evidence is accumulating that short sleep duration is a causal risk factor for CAD and HF; (b) abundant evidence from observational studies supports that long sleep duration is associated with the risk of CAD, stroke, and mortality, and long sleep duration has no causal associations with stroke and CAD in the MR studies; the causation of long sleep duration and other CVDs should be further studied; and (c) emerging evidence indicates that an increase in hours of sleep is associated with a decreased risk of CAD. Finally, we discussed the underlying pathophysiological mechanisms underlying short sleep duration and CVDs and suggested that increasing sleep duration benefits cardiovascular health.

Relationship between circadian syndrome and stroke: A cross-sectional study of the national health and nutrition examination survey

Aim

The aim of this study was to assess the relationship of circadian syndrome and stroke.

Methods

We performed a cross-sectional analysis of 11,855 participants from the National Health and Nutrition Examination Survey (NHANES) database between 2005 and 2018, and collected the baseline characteristics. Multivariate logistic regression models were developed to explore the association between circadian syndrome and stroke. Simultaneously, subgroup analyses based on the difference of gender, race, and components associated with circadian syndrome also were performed. The odds ratio (OR) and 95% CI were calculated in this study.

Results

All the participants were divided into the non-stroke group and the stroke group. There were approximately 3.48% patients exclusively with stroke and 19.03% patients exclusively with circadian syndrome in our study. The results suggested that the risk of stroke in patients with circadian syndrome was higher than that in patients without circadian syndrome (OR = 1.322, 95 CI%: 1.020–1.713). Similar associations were found in women with circadian syndrome (OR = 1.515, 95 CI%: 1.086–2.114), non-Hispanic whites with circadian syndrome (OR = 1.544, 95 CI%: 1.124–2.122), participants with circadian syndrome who had elevated waist circumference (OR = 1.395, 95 CI%: 1.070–1.819) or short sleep (OR = 1.763, 95 CI%: 1.033–3.009).

Conclusion

Circadian syndrome was associated with the risk of stroke. Particularly, we should pay more close attention to the risk of stroke in those populations who were female, non-Hispanic whites, had the symptoms of elevated waist circumference or short sleep.

The Relationship between Sleep Duration and Stroke Risk: The Mediating Role of Physical Activity

Background: This study aimed to investigate the mediating effect of physical activity (PA) on the relationship between average sleep duration and risk of stroke in suburban residents without stroke. Methods: A cross-sectional study was executed, and participants were recruited through a multistage, stratified, probability-proportional-to-size sampling method in this research. The stroke risk was measured using a risk assessment form for a high-risk stroke population. The PA score was calculated by the Physical Activity Rating Scale-3 (PARS-3). The average sleep duration was calculated by adding up night sleep and afternoon nap durations. A multiple linear regression analysis was conducted to identify the association between stroke risk, average sleep duration, and PA. The direct and indirect effects of average sleep duration on stroke risk were analyzed by using the PA in a mediation framework. Results: A total of 5312 suburban residents (average: 54.96 ± 12.21 years, 2970 women) participated in the study. After adjusting for covariates, relatively inappropriate sleep duration (<7 h/>8 h~9 h/>9 h) and stroke risk were significantly associated, compared with the moderate average sleep duration (7~8 h) (β = 0.038, 95% CI: 0.024~0.128; β = 0.078, 95% CI: 0.128~0.250; β = 0.150, 95% CI: 0.390~0.549). The PA total score (indirect effect ab = 0.013, 95% CI: 0.003~0.022) partially mediated the relationship between the long average sleep duration and stroke risk, in which the activity intensity (ab = −0.015, 95% CI: −0.021~−0.008), the activity duration (ab = 0.043, 95% CI: 0.029~0.058), and the activity frequency (ab = 0.012, 95% CI: 0.004~0.020; ab = 0.037, 95% CI: 0.026~0.050) all played a mediating role in the different sleep duration. Conclusions: A significant relationship between a long average sleep duration and stroke risk factors among people without stroke was found in this study. The PA and its components partially mediated the association between a long average sleep duration and stroke risk. Suitable prevention methods and interventions for PA and sleep may reduce the risk of stroke.

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

PURPOSE OF REVIEW

To elucidate the interconnection between sleep and stroke.

RECENT FINDINGS

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