Self-Reported Sleep Duration, Napping, and Incident Heart Failure: Prospective Associations in the British Regional Heart Study

Associations between daytime napping, sleep duration, and depression and 15 cardiovascular diseases: a Mendelian randomization study

Background

Numerous studies have documented the effects of daytime napping, sleep duration, and depression on cardiovascular diseases (CVDs). However, the evidence has been gleaned from observational studies that might be riddled with confounding variables and the possibility of reverse causation bias. Therefore, the present study employed a Mendelian randomization (MR) methodology to meticulously explore the relationships between daytime napping, sleep duration, and depression, and the risk profiles of CVDs.

Methods

Genome-wide significant genetic variants associated with daytime napping, sleep duration, and depression were used as the instrumental variables (IVs). Data on the genetic correlations between these IVs and 15 CVDs were derived from the United Kingdom (UK) Biobank, Finnish Genome Studies, and other large-scale collaborations. We conducted both univariate and multivariate MR analyses to assess the overall effects and mediated relationships after adjusting for potential confounders, including body mass index (BMI), smoking status, and type 2 diabetes. The effect sizes were estimated using inverse variance-weighted (IVW) regression.

Results

The MR analysis revealed that an increased risk of heart failure (HF) [odds ratio (OR): 1.366; 95% confidence interval (CI): 1.013-1.842; P=0.04], coronary atherosclerosis (OR: 1.918; 95% CI: 1.257-2.927; P=0.003), myocardial infarction (MI) (OR: 1.505; 95% CI: 1.025-2.211; P=0.04), and coronary artery disease (CAD) (OR: 1.519; 95% CI: 1.130-2.043; P=0.006) was significantly associated with genetically predicted daytime napping. Prolonged sleep duration was found to be related to a reduced risk of HF (OR: 0.995; 95% CI: 0.993-0.998; P=2.69E-04), peripheral vascular disease (PVD) (OR: 0.984; 95% CI: 0.971-0.997; P=0.02), and CAD (OR: 0.997; 95% CI: 0.994-0.999; P=0.006). Additionally, a statistically significant positive relationship was observed between depressive disorders and the occurrence of atrial fibrillation (AF) (OR: 1.298, 95% CI: 1.065-1.583, P=0.01), indicating a heightened susceptibility. The multivariable MR analyses substantiated the reliability of the observed associations between daytime napping and the incidence of HF and CAD, following adjustments for genetically predicted BMI and smoking. The sensitivity analysis did not reveal any evidence of horizontal pleiotropy or heterogeneity, thus supporting the validity of the study's results.

Conclusions

This MR investigation posits a potential causal nexus between daytime napping, sleep duration, and depression, and the genesis of CVDs, offering new perspectives on the prevention and management of CVDs.

Association between self-reported napping and risk of cardiovascular disease and all-cause mortality: A meta-analysis of cohort studies

OBJECTIVES

This meta-analysis aims to assess the association between adult nap duration and risk of all-cause mortality and cardiovascular diseases (CVD).

METHODS

PubMed, Cochrane Library, Embase and Web of Science databases were searched to identify eligible studies. The quality of observational studies was assessed using the Newcastle-Ottawa Scale. We performed all statistical analyses using Stata software version 14.0. For the meta-analysis, we calculated hazard ratio (HR) and their corresponding 95% confidence intervals (CIs). To assess publication bias, we used a funnel plot and Egger's test.

RESULTS

A total of 21 studies involving 371,306 participants revealed varying methodological quality, from moderate to high. Those who indulged in daytime naps faced a significantly higher mortality risk than non-nappers (HR: 1.28; 95% CI: 1.18-1.38; I2 = 38.8%; P<0.001). Napping for less than 1 hour showed no significant association with mortality (HR: 1.00; 95% CI: 0.90-1.11; I2 = 62.6%; P = 0.971). However, napping for 1 hour or more correlated with a 1.22-fold increased risk of mortality (HR: 1.22; 95% CI: 1.12-1.33; I2 = 40.0%; P<0.001). The risk of CVD associated with napping was 1.18 times higher than that of non-nappers (HR: 1.18; 95% CI: 1.02-1.38; I2 = 87.9%; P = 0.031). Napping for less than 1 hour did not significantly impact CVD risk (HR: 1.03; 95% CI: 0.87-1.12; I2 = 86.4%; P = 0.721). However, napping for 1 hour or more was linked to a 1.37-fold increased risk of CVD (HR: 1.37; 95% CI: 1.09-1.71; I2 = 68.3%; P = 0.007).

CONCLUSIONS

Our meta-analysis indicates that taking a nap increases the risk of overall mortality and CVD mortality. It highlights that the long duration time of the nap can serve as a risk factor for evaluating both overall mortality and cardiovascular mortality.

Associations of objective sleep duration and physical activity with risk of heart failure: A prospective cohort study

OBJECTIVE

This study aimed to investigate the independent and joint associations of accelerometer-derived sleep duration and physical activity (PA) in different intensities with the risk of incident heart failure (HF).

METHODS

The study included 89,572 participants (mean age 62.2 ± 7.8 years, 42.8% male) from the UK Biobank. Sleep duration (short: <6 h/day; normal: 6-8 h/day; long: >8 h/day) and PA [total PA, light PA (LPA), moderate-to-vigorous PA (MVPA), vigorous PA (VPA)] were measured using accelerometers over 7 days. MVPA and VPA were categorized according to the World Health Organization's recommended levels, while LPA and total PA were categorized based on the median. HF cases were identified through hospital records or death registries.

RESULTS

Over a 7-year follow-up period, 1324 participants (2.1%; incidence rate, 2.1 per 1000 person-years) developed HF. Short, but not long, sleep duration was linked to a 33% increased risk of HF [hazard ratio (HR) 1.33, 95% confidence interval (CI): 1.11-1.59]. This increased risk associated with short sleep could be mitigated by increasing PA, especially to the levels of recommended MVPA or VPA. In joint analyses, compared to participants meeting the recommended MVPA and with normal sleep duration, those not meeting the MVPA recommendation and with short sleep had the highest HF risk (HR 1.78, 95% CI: 1.42-2.25).

CONCLUSIONS

Accelerometer-derived short, but not long, sleep duration was associated with a higher risk of incident HF. Engaging in sufficient PA, especially recommended MVPA or VPA, can partially mitigate this risk.

Rehospitalisation risk by hypnotics class in older patients with heart failure: a cohort study utilizing administrative claims data in Japan

BACKGROUND

Studies comparing the safety of orexin receptor antagonists and other hypnotic types for older patients with heart failure (HF) remain lacking. This study aimed to compare orexin receptor antagonists (suvorexant) with benzodiazepines or Z-drugs for sleep treatment and investigate the risk of acute HF-related rehospitalisation in older patients with HF.

METHODS

This study used a cohort design to analyse data from an administrative claims database from April 2008 to December 2020. The study population was determined based on inclusion and exclusion criteria from a cohort of 1 159 937 patients aged ≥65 years, selected through random sampling. The follow-up period was censored based on multiple criteria, including outcome occurrences and hypnotic classification changes. Kaplan-Meier survival analysis and Cox proportional hazards models were conducted for risk assessment.

RESULTS

The analysis included 1858 patients, aged ≥65 years and experiencing their first HF-related hospitalisation. These patients were categorised based on the initially prescribed hypnotic classification, including suvorexant, benzodiazepines and Z-drugs in 490, 606 and 762 patients, respectively. The average age and SD were similar across all hypnotic classes at 82.7±7.6 years. Kaplan-Meier curves indicated a higher trend of rehospitalisation risk for benzodiazepines and Z-drugs than for suvorexant. The adjusted HRs were 2.77 (95% CI 1.17 to 6.52) for benzodiazepines and 2.98 (95% CI 1.33 to 6.68) for Z-drugs.

CONCLUSIONS

Suvorexant administration for sleep treatment in older patients with HF shows a potentially reduced risk of acute HF-related rehospitalisation compared with benzodiazepines and Z-drugs. The results of this study provide valuable information for selecting hypnotics in older patients with HF having concurrent sleep disorders.

To nap or not? Evidence from a meta-analysis of cohort studies of habitual daytime napping and health outcomes

Habitual daytime napping is a common behavioral and lifestyle practice in particular countries and is often considered part of a normal daily routine. However, recent evidence suggests that the health effects of habitual daytime napping are controversial. We systematically searched PubMed, Web of Science, Embase, and Cochrane Library databases from inception to March 9, 2024, to synthesize cohort studies of napping and health outcome risk. A total of 44 cohort studies with 1,864,274 subjects aged 20-86 years (mean age 56.4 years) were included. Overall, habitual napping increased the risk of several adverse health outcomes, including all-cause mortality, cardiovascular disease, metabolic disease, and cancer, and decreased the risk of cognitive impairment and sarcopenia. Individuals with a napping duration of 30 min or longer exhibited a higher risk of all-cause mortality, cardiovascular disease, and metabolic disease, whereas those with napping durations less than 30 min had no significant risks. No significant differences in napping and health risks were observed for napping frequency, percentage of nappers, sample size, sex, age, body mass index, follow-up years, or comorbidity status. These findings indicate that individuals with a long napping duration should consider shortening their daily nap duration to 30 min or less.

Relationship between daytime napping and cardiovascular disease: A two-sample mendelian randomization study

OBJECTIVE

Daytime napping has been reported to have a potential association with an increased risk of cardiovascular diseases (CVDs) in several cohort studies, but the causal effects are unclear. In this study, we aimed to investigate the relationship between daytime napping and CVDs, as well as to validate causality in this relationship by Mendelian randomization (MR).

METHODS

A two-sample MR method was used to evaluate the causal effect of daytime napping on CVDs. The exposure of daytime napping was extracted from publicly available genome-wide association studies (GWASs) in the UK Biobank, and the outcomes of 14 CVDs were obtained from the FinnGen consortium. A total of 49 single-nucleotide polymorphisms (SNPs) were used as the instrumental variables. The effect estimates were calculated by using the inverse-variance weighted method.

RESULTS

The MR analyses showed that genetically predicted daytime napping was associated with an increased risk of five CVDs, including heart failure (odds ratio (OR): 1.71, 95% CI: 1.19-2.44, p = 0.003), hypertension (OR: 1.51, 95% CI: 1.05-2.16, p = 0.026), atrial fibrillation (OR: 1.71, 95% CI: 1.02-2.88, p = 0.042), cardiac arrythmias (OR: 1.47, 95% CI: 1.47, 95% CI: 1.01-2.13, p = 0.042) and coronary atherosclerosis (OR: 1.77, 95% CI: 1.17-2.68, p = 0.006). No significant influence was observed for other CVDs.

CONCLUSION

This two-sample MR analysis suggested that daytime napping was causally associated with an increased risk of heart failure, hypertension, atrial fibrillation, cardiac arrythmias and coronary atherosclerosis.

Association of healthy sleep pattern with risk of recurrent cardiovascular events among patients with coronary heart disease

AIMS

To examine the association of a healthy sleep pattern with the risk of recurrent cardiovascular events among patients with coronary heart disease (CHD).

METHODS AND RESULTS

This prospective cohort study included 21 193 individuals with CHD from the UK Biobank. A healthy sleep score was generated based on a combination of chronotype, sleep duration, insomnia, and excessive daytime sleepiness. Cox proportional hazards regression models were applied to estimate the associations between healthy sleep score and recurrent cardiovascular events. During a median of 11.1 years of follow up, we documented 3771 recurrent cardiovascular events, including 1634 heart failure cases and 704 stroke cases. After multivariable adjustment, including lifestyle factors, medical history, and CHD duration, sleep 7-8 h/day, never/rarely insomnia, and no frequent daytime sleepiness were each significantly associated with a 12-22% lower risk of heart failure. In addition, compared with participants who had a healthy sleep score of 0-1, the multivariable-adjusted HR (95% CI) for participants with a healthy sleep score of 4 was 0.86 (0.75, 0.99) for recurrent cardiovascular events, 0.71 (0.57, 0.89) for heart failure, and 0.72 (0.51, 1.03) for stroke.

CONCLUSIONS

Adherence to a healthy sleep pattern was significantly associated with a lower risk of recurrent cardiovascular events among patients with CHD, especially for heart failure. These findings indicate that healthy sleep behaviours could be beneficial in the prevention of cardiovascular event recurrence.

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.

Effect of insomnia and excessive daytime sleepiness on cardiac functions in older adults

BACKGROUND

We investigated the potential harmful effect in older adults of insomnia and excessive daytime sleepiness (EDS) on myocardial functions and electrophysiologic changes of the heart in terms of heart rate and QT intervals corrected for heart rate (QTc).

METHODS

The study included 32 insomnia patients and 30 control subjects. An Insomnia Severity Index score of ≥15 indicated insomnia, while a score of <8 was accepted as the control group. The Epworth Sleepiness Scale was used to assess EDS, with a score of ≥11/24 points indicating EDS. Diastolic and systolic functions were evaluated in each patient by transthoracic two-dimensional, conventional and tissue Doppler echocardiography. Heart rate and QTc were calculated for electrophysiologic changes.

RESULTS

The mean age was 73.2 ± 7.9 years, with 59.7% being female. Biventricular systolic and diastolic functions were impaired in the insomnia patients. The E' value for diastolic function was lower in the patients with insomnia than the controls (5.99 ± 1.59 vs. 6.88 ± 0.97, P = 0.053). Furthermore, values for the systolic function parameters Lateral-S (7.41 ± 1.92 vs. 9.37 ± 1.83, P < 0.001), Septal-S (6.69 ± 1.40 vs. 8.10 ± 1.30, P = 0.001), and Tricuspid-S (12.25 ± 2.00 vs. 14.37 ± 3.13, P = 0.004) were lower for insomnia patients than for controls. In the case of EDS coexistence, the heart rate and QTc values were higher than the controls (76.47 ± 7.18 vs. 71.03 ± 10.95, P = 0.001, and 413.72 ± 28.24 vs. 394.67 ± 24.47, P = 0.015, respectively).

CONCLUSION

Insomnia is associated with impaired systolic-diastolic functions, independent of EDS. The co-existence of insomnia and EDS may lead to electrophysiological changes in older adults, including increased heart rate and longer QTc.

The Circadian Biology of Heart Failure

Driven by autonomous molecular clocks that are synchronized by a master pacemaker in the suprachiasmatic nucleus, cardiac physiology fluctuates in diurnal rhythms that can be partly or entirely circadian. Cardiac contractility, metabolism, and electrophysiology, all have diurnal rhythms, as does the neurohumoral control of cardiac and kidney function. In this review, we discuss the evidence that circadian biology regulates cardiac function, how molecular clocks may relate to the pathogenesis of heart failure, and how chronotherapeutics might be applied in heart failure. Disrupting molecular clocks can lead to heart failure in animal models, and the myocardial response to injury seems to be conditioned by the time of day. Human studies are consistent with these findings, and they implicate the clock and circadian rhythms in the pathogenesis of heart failure. Certain circadian rhythms are maintained in patients with heart failure, a factor that can guide optimal timing of therapy. Pharmacologic and nonpharmacologic manipulation of circadian rhythms and molecular clocks show promise in the prevention and treatment of heart failure.

Causal relationships of excessive daytime napping with atherosclerosis and cardiovascular diseases: a Mendelian randomization study

STUDY OBJECTIVES

Previous observational studies have found conflicting evidence on the relationship between daytime napping and incident cardiovascular diseases (CVDs), but it remains unclear whether these associations present causality. This study aims to verify whether and why there is a causal relationship between these parameters, and whether there is an etiological basis.

METHODS

A two-sample Mendelian randomization analysis was performed using 79 single nucleotide polymorphisms associated with daytime napping. Summary-level data for coronary atherosclerosis, peripheral atherosclerosis, total CVD, and five CVD outcomes were obtained from the FinnGen study. Meta-analyses were aimed at investigating the relationships of excessive daytime napping with total CVD, coronary heart disease, myocardial infarction (MI), and stroke incidence. Subgroup, network meta-analysis (NMA) and trial sequential analysis (TSA) were also performed in this study.

RESULTS

The inverse-variance weighted method demonstrated that a genetic predisposition to more frequent daytime napping was significantly associated with higher odds of coronary atherosclerosis (odds ratio [OR] = 1.55, 95% confidence interval [CI]: 1.11 to 2.17), MI (OR = 1.63, 95% CI: 1.06 to 2.50), and heart failure (OR = 1.80, 95%CI: 1.28 to 2.52). In NMA, an increased risk of developing CVD in people who napped for more than 60 min a day than those who did not nap was demonstrated and then supported by TSA results (summary relative risk = 1.98, 95% CI: 1.39 to 2.82).

CONCLUSION

Habitual daytime napping is causally associated with an increased risk of incident CVD primarily via the development of coronary atherosclerosis. An average napping duration of more than 60 min is associated with an elevated risk of CVD in all participants.

Prospective study of sleep duration, snoring and risk of heart failure

OBJECTIVE

To investigate whether nighttime sleep duration and snoring status were associated with incident heart failure (HF).

METHODS

A prospective study was conducted based on Kailuan cohort including 93 613 adults free of pre-existing cardiovascular diseases. Sleep duration and snoring status were assessed by self-reported questionnaire. Incident HF cases were ascertained by medical records. Cox proportional hazards model was applied to calculate the HR and 95% CI of risk of developing HF. Mediation analysis was used to understand whether hypertension and diabetes mediated the association between sleep duration, snoring and HF. Data analysis was performed from 1 June 2021 to 1 June 2022.

RESULTS

During a median follow-up of 8.8 years, we documented 1343 incident HF cases. Relative to sleep duration of 7.0-7.9 hour/night, short sleep duration was associated with higher risk of developing HF: adjusted HR was 1.24 (95% CI 1.01 to 1.55) for <6 hours/night and 1.29 (95% CI 1.06 to 1.57) for 6.0-6.9 hours/night, after adjustment for potential confounders such as age, sex, smoking, hypertension and diabetes. A similar 20%-30% higher risk of incident HF was found in individuals reporting occasional or frequent snoring relative to never/rare snorers: adjusted HR was 1.32 for occasional snoring (95% CI 1.14 to 1.52) and 1.24 (95% CI 1.06 to 1.46) for frequent snoring. Presence of diabetes significantly mediated the association between both short sleep duration and snoring and HF risk and hypertension significantly mediated the snoring-HF relationship.

CONCLUSION

Short sleep duration and snoring were associated with high risk of HF.

Association of sleep duration and physical frailty with cognitive function in older patients with coexisting atrial fibrillation and heart failure

AIM

To investigate the associations of sleep duration and physical frailty with cognitive function in older patients with both atrial fibrillation and heart failure.

DESIGN

This study used a cross-sectional, secondary data analysis design.

METHOD

We included outpatients aged ≥ 65 years with coexisting atrial fibrillation and heart failure in South Korea. We used a sample of 176 patients (men = 100) with HF among 277 data from the parent study. The data were collected through a self-report, structured questionnaire and electronic medical record.

RESULTS

Our main finding showed that long sleep duration and physically frail status were significant predictors of cognitive impairment in older adults with both atrial fibrillation and heart failure. Healthcare providers should be aware of the importance of assessing sleep duration and physical activity in older adults with both atrial fibrillation and heart failure to prevent or delay cognitive impairment.

Self-reported daytime napping, daytime sleepiness, and other sleep phenotypes in the development of cardiometabolic diseases: a Mendelian randomization study

AIMS

Sleep disorders are associated with an increased risk of cardiometabolic diseases in observational studies, but the causality remains unclear. In this study, we leveraged two-sample Mendelian randomization (MR) analyses to assess the causal associations of self-reported daytime napping, daytime sleepiness, and other sleep phenotypes with cardiometabolic diseases including ischaemic stroke (IS), coronary artery disease (CAD), heart failure (HF), and Type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

We selected genetic variants as instrumental variables for self-reported daytime napping, daytime sleepiness, morning person, insomnia, short sleep duration, and long sleep duration from European-descent genome-wide association studies (GWASs). Summary statistics for cardiometabolic diseases originated from four different GWASs with a total of 2 500 086 participants. We used the inverse-variance weighted method to explore the role of self-reported sleep phenotypes on the aetiology of cardiometabolic diseases in the main analyses, followed by several sensitivity analyses for robustness validation. Genetically predicted self-reported daytime napping [T2DM: OR, 1.56 (95% confidence interval, 1.21-2.02)], insomnia [IS: OR, 1.07 (1.04-1.11)]; CAD: OR, 1.13 (1.08-1.17); HF: OR, 1.10 (1.07-1.14); T2DM: OR, 1.16 (1.11-1.22); and short sleep duration [CAD: OR, 1.37 (1.21-1.55)] were causally associated with an elevated risk of cardiometabolic diseases. Moreover, genetically determined self-reported daytime sleepiness [CAD: OR, 2.05 (1.18-3.57); HF: OR, 1.82 (1.15-2.87)] and morning person [HF: 1.06 OR, (1.01-1.11)] had potential detrimental effect on cardiometabolic risks.

CONCLUSION

Self-reported daytime napping, insomnia, and short sleep duration had causal roles in the development of cardiometabolic diseases, while self-reported daytime sleepiness and morning person was the potential risk factor for cardiometabolic diseases.

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.

Snoring and napping independently increased the serum uric acid levels and hyperuricemia risk: The Henan Rural Cohort Study

BACKGROUND AND AIMS

Evidence on the association of snoring, daily sleep duration (daytime napping and night sleep duration) with hyperuricemia (HUA) was limited, especially in the resources-poor areas. This study aimed to investigate the independent effect of snoring frequency and daily sleep duration on HUA prevalence in rural Chinese adults.

METHODS AND RESULTS

29,643 participants aged 18-79 years were included in the final cross-sectional analysis from the Henan Rural Cohort Study. Multivariate logistic regression and linear regression models with HUA and serum uric acid (SUA) levels as dependent variables were conducted, respectively. Of the 29,643 included adults, 3498 suffered from HUA. Compared to never snoring, the adjusted odds ratio (OR) and 95% confidence interval (CI) of HUA for rare snoring, occasional snoring, and habitual snoring were 1.35 (1.17, 1.56), 1.30 (1.14, 1.47), and 1.59 (1.47, 1.73), respectively (P for trend <0.001). Compared with no napping, participants who had daytime napping of 61-90 and > 91 min were associated with a 29% and 30% increase in the prevalence of HUA, respectively (P for trend <0.001). But in night sleep duration groups, no significant associations were observed. The positive associations between snoring and HUA were attenuated in people aged ≥65 and people with type 2 diabetes mellitus (both P for interaction <0.05).

CONCLUSION

Habitual snoring or longer daytime napping was independently associated with increased HUA prevalence and SUA levels in rural Chinese adults, which indicates the significance of early intervention and treatment of snoring and longer daytime napping to prevent hyperuricemia.

Abnormal Sleep Duration as Predictor for Cardiovascular Diseases: A Systematic Review of Prospective Studies

Methods

We searched the online database PubMed on 30 August 2020 for our data collection. We used the following keywords: sleep duration AND (cardiovascular disease OR cardiovascular event) AND (cohort OR prospective OR retrospective). We identified 653 studies, and after excluding studies that were published before 2015, we obtained 306 studies. After filtering the 306 studies through title and abstract screening and applying the inclusion and exclusion criteria, we further reviewed fourteen studies with full-text reading. We excluded three studies because of insufficient data required and included eleven studies in this systematic review.

Results

A total of 361,041 participants from ten studies were included in this systematic review. The incidence of hypertension, myocardial infarction, coronary artery disease, heart failure, cardiovascular events, and cardiovascular diseases in the short sleep duration group is 46.12%, 0.59%, 5.43%, 0.09%, 7.18%, 1.48%, and 6.8%, consecutively, while the incidence of hypertension, myocardial infarction, coronary artery disease, and heart failure in the long sleep duration group is 30.71%, 0.61%, 6.55%, 1.11%, and 6.04%, consecutively. Nine studies reported an association between sleep duration and cardiovascular diseases while one study reported no association. Seven studies reported that short sleep duration was significantly associated with CVD. Short sleep duration in this study was associated with hypertension and heart failure. Atrial fibrillation and coronary artery disease were associated with both short and long sleep duration.

Conclusion

Abnormal sleep duration (short and long sleep duration) may act as the predictor of cardiovascular diseases. The importance of having normal sleep duration should be stressed with other lifestyle modification to avoid the risk of getting cardiovascular diseases. However, further studies are needed to overcome the limitation of this systematic review.

Causal Roles of Sleep Duration in Osteoporosis and Cardiometabolic Diseases: A Mendelian Randomization Study

Sleep duration suggests some association with osteoporosis and cardiometabolic diseases, but it is unknown if these associations are causal or confounded. In this two-sample Mendelian randomization (MR) study, we included the largest genome-wide association studies (GWASs) associated with sleep duration and the outcome measures of osteoporosis and cardiometabolic diseases. Finally, 25 single nucleotide polymorphisms (SNPs) associated with short sleep duration and 7 SNPs associated with long sleep duration obtained the genome-wide significance (P < 5 × 10^-8) and were used as instrumental variables. Genetic predisposition to short sleep duration was strongly associated with increased risk of coronary artery disease (beta-estimate: 0.199, 95% confidence interval CI: 0.081 to 0.317, standard error SE:0.060, P value = 0.001) and heart failure (beta-estimate: 0.145, 95% CI: 0.025 to 0.264, SE:0.061, P value = 0.017), which were both confirmed by the sensitivity analyses. Both short and long sleep duration may reduce the estimated bone mineral density (eBMD, beta-estimate: -0.086, 95% CI: -0.141 to -0.031, SE:0.028, P value = 0.002 for short sleep duration; beta-estimate: -0.080, 95% CI: -0.120 to -0.041, SE:0.020, P value < 0.0001 for long sleep duration). There was limited evidence of associations between sleep duration and fracture, type 2 diabetes, atrial fibrillation, fasting glucose, fasting insulin, or HbA1c. This study provides robust evidence that short sleep duration is causally associated with high risk of coronary artery disease and heart failure and suggests that short sleep duration should be avoided to prevent these two cardiovascular diseases. Short and long sleep duration show some MR association with reduced eBMD, which indicates that both short and long sleep duration may be prevented to reduce the incidence of osteoporosis.

Sleep-disordered breathing is independently associated with elevated natriuretic peptide levels in patients with cardiovascular diseases

Sleep disorders and sleep duration have attracted considerable attention as potential modifiable risk factors for the development and progression of heart failure (HF). However, whether these sleep behaviors could aggravate the underlying cardiac condition remains ambiguous. We evaluated the associations between the levels of plasma B-type natriuretic peptide (BNP) and sleep-disordered breathing (SDB), sleep quality and quantity, or daytime sleepiness in cardiovascular diseases (CVD) patients. A total of 1717 consecutive patients with CVD [median age, 66 years (55-74 years); female, 27.5%] were enrolled. SDB was screened by nocturnal pulse oximetry; sleep quality and quantity were determined by Pittsburg Sleep Quality Index, and daytime sleepiness was examined by Epworth Sleepiness Scale. The median plasma BNP level was 54.9 pg/ml (23.5-146.4 pg/ml). Multiple regression analyses showed that the BNP level in the highest quintile (BNP > 181.8 pg/ml) was associated with SDB (severe: OR, 5.88; 95% CI 3.17-10.88; moderate: OR, 3.62; 95% CI 2.17-6.02; mild: OR, 2.22: 95% CI 1.42-3.47). There were no significant associations between other sleep parameters and higher BNP levels. The relationship between SDB and BNP levels was unchanged regardless of the previous history of symptomatic HF. SDB was independently associated with the elevated plasma BNP level in patients with a variety of CVD.

Prognostic Impact of Sleep Patterns and Related-Drugs in Patients with Heart Failure

Sleep disturbances are frequent among patients with heart failure (HF). We hypothesized that self-reported sleep disturbances are associated with a poor prognosis in patients with HF. A longitudinal study of 119 patients with HF was carried out to assess the association between sleep disturbances and the occurrence of major cardiovascular events (MACE). All patients with HF completed self-administered questionnaires on sleepiness, fatigue, insomnia, quality of sleep, sleep patterns, anxiety and depressive symptoms, and central nervous system (CNS) drugs intake. Patients were followed for a median of 888 days. Cox models were used to estimate the risk of MACE associated with baseline sleep characteristics. After adjustment for age, the risk of a future MACE increased with CNS drugs intake, sleep quality and insomnia scores as well with increased sleep latency, decreased sleep efficiency and total sleep time. However, after adjustment for left ventricular ejection fraction and hypercholesterolemia the HR failed to be significant except for CNS drugs and total sleep time. CNS drugs intake and decreased total sleep time were independently associated with an increased risk of MACE in patients with HF. Routine assessment of self-reported sleep disturbances should be considered to prevent the natural progression of HF.

Healthy Sleep Patterns and Risk of Incident Arrhythmias

BACKGROUND

Emerging evidence has linked sleep behaviors with the risk of cardiac arrhythmias. The various sleep behaviors are typically correlated; however, most of the previous studies only focused on the individual sleep behavior, without considering the overall sleep patterns.

OBJECTIVES

The purpose of this study was to prospectively investigate the associations between a healthy sleep pattern with the risks of cardiac arrhythmias.

METHODS

A total of 403,187 participants from UK Biobank were included. A healthy sleep pattern was defined by chronotype, sleep duration, insomnia, snoring, and daytime sleepiness. Weighted genetic risk score for atrial fibrillation was calculated.

RESULTS

The healthy sleep pattern was significantly associated with lower risks of atrial fibrillation/flutter (AF) (HR comparing extreme categories: 0.71; 95% CI: 0.64-0.80) and bradyarrhythmia (HR: 0.65; 95% CI: 0.54-0.77), but not ventricular arrhythmias, after adjustment for demographic, lifestyle, and genetic risk factors. Compared with individuals with a healthy sleep score of 0-1 (poor sleep group), those with a healthy sleep score of 5 had a 29% and 35% lower risk of developing AF and bradyarrhythmia, respectively. Additionally, the genetic predisposition to AF significantly modified the association of the healthy sleep pattern with the risk of AF (P interaction = 0.017). The inverse association of the healthy sleep pattern with the risk of AF was stronger among those with a lower genetic risk of AF.

CONCLUSIONS

Our results indicate that a healthy sleep pattern is associated with lower risks of AF and bradyarrhythmia, independent of traditional risk factors, and the association with AF is modified by genetic susceptibility.

Objective Assessment of Daytime Napping and Incident Heart Failure in 1140 Community-Dwelling Older Adults: A Prospective, Observational Cohort Study

Background Disrupted nighttime sleep has been associated with heart failure (HF). However, the relationship between daytime napping, an important aspect of sleep behavior commonly seen in older adults, and HF remains unclear. We sought to investigate the association of objectively assessed daytime napping and risk of incident HF during follow-up. Methods and Results We studied 1140 older adults (age, 80.7±7.4 [SD] years; female sex, 867 [76.1%]) in the Rush Memory and Aging Project who had no HF at baseline and were followed annually for up to 14 years. Motor activity (ie, actigraphy) was recorded for ≈10 days at baseline. We assessed daytime napping episodes between 9 am and 7 pm objectively from actigraphy using a previously published algorithm for sleep detection. Cox proportional hazards models examined associations of daily napping duration and frequency with incident HF. Eighty-six participants developed incident HF, and the mean onset time was 5.7 years (SD, 3.4; range, 1-14). Participants who napped longer than 44.4 minutes (ie, the median daily napping duration) showed a 1.73-fold higher risk of developing incident HF than participants who napped <44.4 minutes. Consistently, participants who napped >1.7 times/day (ie, the median daily napping frequency) showed a 2.20-fold increase compared with participants who napped <1.7 times/day. These associations persisted after adjustment for covariates, including nighttime sleep, comorbidities, and cardiovascular disease/risk factors. Conclusions Longer and more frequent objective napping predicted elevated future risk of developing incident HF. Future studies are needed to establish underlying mechanisms.

Sleep fragmentation and incidence of congestive heart failure: the Sleep Heart Health Study

STUDY OBJECTIVES

Sleep fragmentation (SF) has been reported to be associated with cardiovascular risk. The aim of this study was to explore the relationship between SF and congestive heart failure (CHF).

METHODS

A total of 4,887 participants (2,256 males and 2,631 females, mean age of 63.6 ± 11.0 years) from the Sleep Heart Health Study (SHHS) were included in this study. Incident CHF was defined as the first occurrence of CHF between baseline in-home polysomnography (PSG) and the end of follow-up. Objective assessments for SF, including sleep fragmentation index (SFI), arousal index (ArI), sleep efficiency (SE), and wake after sleep onset (WASO), were determined based on in-home polysomnography records. Multivariate Cox regression analysis was used to investigate the relationship between SF and incident CHF.

RESULTS

During an average of 10 years of follow-up, 543 participants with CHF (11.1%) were observed. Individuals with CHF had a significantly higher SFI, total ArI, and WASO and a lower SE than controls. After multivariate Cox regression analysis, SE (odds ratio [OR], 0.967; 95% confidence interval [CI] 0.955-0.978; P < 0.001), WASO (OR, 1.009; 95% CI 1.006-1.012; P < 0.001), SFI (OR, 1.046; CI 1.007-1.086; P = 0.021), and total ArI (OR, 1.018; 95% CI 1.000-1.035; P = 0.044) were found to be associated with the incidence of CHF in participants without hypertension.

CONCLUSIONS

Objectively measured SF was associated with the incidence of CHF. The role of SFI, total ArI, SE, and WASO deserves further investigation.

Association of Sleep Duration With Atrial Fibrillation and Heart Failure: A Mendelian Randomization Analysis

Both short (<7 h per night) and long (≥9 h per night) sleep durations are related to atrial fibrillation (AF) and heart failure (HF), but their causality has not been confirmed. We applied Mendelian randomization (MR) approaches to estimate the causal association between genetically determined sleep duration and the risk of AF and HF. We performed two-sample MR analysis to obtain the effect of sleep duration on AF and HF. Instrumental variables were constructed using genetic variants known to be associated with continuous sleep duration, short sleep duration, and long sleep duration. MR estimates of the effect of sleep duration on AF and HF were derived based on two large meta-analyses of genome-wide association studies. The pooled MR estimate demonstrated a significant protective effect of continuous sleep duration on HF [odds ratio (OR) = 0.765, 95% confidence interval (CI) = 0.675–0.867; P = 2.64 × 10^–5] and a suggestive inverse association of continuous sleep duration with AF (OR = 0.893, 95% CI = 0.804–0.991; P = 0.034). In addition, the results showed a suggestive detrimental effect of short sleep duration on the risk of AF (OR = 1.108, 95% CI = 1.017–1.207; P = 0.019) and HF (OR = 1.136, 95% CI = 1.025–1.258; P = 0.015). Conversely, there is no significant evidence for the causal protective effect of long sleep duration on AF (OR = 0.956, P = 0.410) and HF (OR = 0.921, P = 0.202). This MR study indicated that genetically determined continuous sleep duration has a significant protective effect on HF and a suggestive inverse association with AF. Short sleep duration is positively associated with the risk of AF and HF. Nevertheless, there is no significant evidence for the causal protective effect of long sleep duration on AF and HF. Larger intervention studies are required to confirm the effectiveness of improving sleep on reducing the incidence of AF and HF.

Sleeping Difficulty and Subjective Short Sleep Duration are Associated with Serum N-terminal Pro-brain Natriuretic Peptide Levels in the Elderly Population

Objective It is well known that poor sleep increases the risk of heart failure (HF). However, the underlying mechanisms remain unclear. In this study, we investigated the association of poor sleep with hemodynamic stress on the left ventricle, which was a key factor for the development of HF in elderly individuals. Methods A total of 2,301 participants (≥65 years old) without cardiac disease were enrolled in this cross-sectional analysis. We evaluated the subjective sleep quality, sleeping difficulty, subjective sleep duration, use of sleeping pills, and daytime dysfunction using the Pittsburgh Sleep Quality Index, a 19-item self-reported questionnaire. We assessed serum N-terminal pro-brain natriuretic peptide (NT-proBNP) as a marker of hemodynamic stress on the left ventricle, and we defined high NT-proBNP as a serum NT-proBNP level ≥ 125 pg/mL. Results Sleeping difficulty was significantly associated with high NT-proBNP levels [odds ratio (OR), 1.46; 95% confidence interval (CI), 1.16-1.85; p<0.005]. A subjective short sleep duration was also significantly associated with high NT-proBNP levels (OR, 1.69; 95% CI, 1.03-2.75; p<0.05). A subjective poor sleep quality, the use of sleeping pills, and daytime dysfunction were not associated with serum NT-proBNP levels. All data were adjusted for the age, sex, body mass index, serum hemoglobin concentration, serum creatinine level, systolic blood pressure, diastolic blood pressure, and use of antihypertensive medications. Conclusion Poor sleep was associated with high hemodynamic stress to the left ventricle in elderly population.

Modifiable lifestyle factors and heart failure: A Mendelian randomization study

BACKGROUND

Lifestyle factors may be important targets in the prevention of heart failure. The current knowledge on the relationship between lifestyle factors and heart failure originates mostly from observational studies. The objective of this study was to investigate causal associations of multiple lifestyle factors with heart failure risk by using Mendelian randomization.

METHODS

We obtained summary statistics data for single nucleotide polymorphisms associated with the following 5 lifestyle factors at genome-wide significance in genome-wide association studies of European-descent individuals: smoking, alcohol consumption, coffee consumption, physical activity, and sleep duration. The corresponding data for heart failure were acquired from a genome-wide association study comprising 47,309 cases and 930,014 controls of European ancestry. For the primary analyses, we used the inverse-variance weighted method.

RESULTS

Genetic predisposition to smoking initiation (ever smoked regularly) was robustly associated with a higher odds of heart failure (odds ratio: 1.28; 99% CI: 1.21-1.35). Genetically predicted longer sleep duration was associated with a lower odds of heart failure (odds ratio per hour/day: 0.73; 99% CI: 0.60-0.89). We found no associations of alcohol consumption, coffee consumption, and physical activity with heart failure.

CONCLUSIONS

This Mendelian randomization study showed that smoking initiation increases heart failure risk, whereas longer sleep duration decreases the risk of heart failure. Sleep duration should be regarded as novel risk factor in heart failure prevention guidelines. The potential causal role of alcohol and coffee consumption and physical activity for heart failure warrants further investigation in future larger Mendelian randomization analyses.

Association of daytime napping with incident cardiovascular disease in a community-based population

OBJECTIVE

To investigate the association between self-reported daytime napping habits and cardiovascular disease (CVD) in a large community-based study population.

METHODS

Of the 4170 participants, 55.5% were women and the mean age was 63.1 years (SD, 11.0 years). CVD included cardiovascular death, congestive heart failure, myocardial infarction, stroke, angina, and revascularization and was defined as the first confirmed incidence of CVD during an average 11-year follow-up. Self-reported daytime napping habits were recorded using baseline questionnaires. Backward stepwise Cox regression analysis was used to explore the relationship between CVD and napping habits.

RESULTS

In this study, 914 participants with CVD (21.9%) were observed. Participants who took regular long naps had a higher prevalence of incident CVD than did those who took regular short naps, irregular naps, or no naps (34.5% vs. 28.4%, 22.4%, 16.6%, respectively; P < 0.001). In the final backward stepwise Cox regression model, regular long naps were found to be associated with CVD (HR: 1.403, 95% CI: 1.079-1.825, P = 0.012).

CONCLUSIONS

Regular long daytime napping was an independent risk factor for CVD. Healthy sleep habits may promote human health and prevent CVD.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00005275.

Effects of suvorexant on sleep apnea in patients with heart failure: A protocol of crossover pilot trial

BACKGROUND

Suvorexant, an orexin receptor antagonist, is known as a safe and effective sleep medication. Many patients with heart failure (HF) have sleep-disordered breathing (SDB) and are short sleepers, and it is unknown whether suvorexant is effective in HF patients and can improve insomnia safely. The aim of this study is to examine the effect of suvorexant on SDB in patients with HF.

METHODS

The Heart Failure with Insomnia and Suvorexant trial of Juntendo University Hospital and Juntendo Shizuoka Hospital (J-FLAVOR trial) is a multicenter trial with a randomized double crossover design. We will enroll a total of 30 HF patients treated in the Juntendo University Hospital and Juntendo Shizuoka Hospital. Eligible patients will undergo portable sleep monitoring twice with or without oral administration of suvorexant in a randomly assigned order. Before the study night, patients in the suvorexant first group will receive suvorexant for 4 consecutive days. There are at least 3 wash-out days between the study nights with and without suvorexant. Primary outcome measures of the non-inferiority trial of suvorexant include the apnea-hypopnea index and the severity of SDB, and the results will be compared between the study nights with and without suvorexant.

CONCLUSION

The present study can determine whether suvorexant can be used in HF patients without affecting their SDB. This is a pilot study to primarily assess whether suvorexant affects the severity of SDB in patients with HF. Therefore, further study is warranted to investigate whether suvorexant alters short- and long-term clinical outcomes by providing longer and better sleep in patients with HF.

Self-reported sleep duration and napping, cardiac risk factors and markers of subclinical vascular disease: cross-sectional study in older men

STUDYOBJECTIVES

Daytime sleep has been associated with increased risk of cardiovascular disease and heart failure (HF), but the mechanisms remain unclear. We have investigated the association between daytime and night-time sleep patterns and cardiovascular risk markers in older adults including cardiac markers and subclinical markers of atherosclerosis (arterial stiffness and carotid intima-media thickness (CIMT)).

METHODS

Cross-sectional study of 1722 surviving men aged 71-92 examined in 2010-2012 across 24 British towns from a prospective study initiated in 1978-1980. Participants completed a questionnaire and were invited for a physical examination. Men with a history of heart attack or HF (n=251) were excluded from the analysis.

RESULTS

Self-reported daytime sleep duration was associated with higher fasting glucose and insulin levels (p=0.02 and p=0.01, respectively) even after adjustment for age, body mass index, physical activity and social class. Compared with those with no daytime sleep, men with daytime sleep >1 hour, defined as excessive daytime sleepiness (EDS), had a higher risk of raised N-terminal pro-brain natriuretic peptide of ≥400 pg/mL, the diagnostic threshold for HF (OR (95% CI)=1.88 (1.15 to 3.1)), higher mean troponin, reduced lung function (forced expiratory volume in 1 s) and elevated von Willebrand factor, a marker of endothelial dysfunction. However, EDS was unrelated to CIMT and arterial stiffness. By contrast, night-time sleep was only associated with HbA1c (short or long sleep) and arterial stiffness (short sleep).

CONCLUSIONS

Daytime sleep duration of >1 hour may be an early indicator of HF.

Self-Reported Sleep Duration, Napping, and Incident Heart Failure: Prospective Associations in the British Regional Heart Study

Objectives

To examine the associations between self‐reported nighttime sleep duration and daytime sleep and incident heart failure (HF) in men with and without preexisting cardiovascular disease (CVD).

Design

Population‐based prospective study.

Setting

General practices in 24 British towns.

Participants

Men aged 60–79 without prevalent HF followed for 9 years (N = 3,723).

Measurements

Information on incident HF cases was obtained from primary care records. Assessment of sleep was based on self‐reported sleep duration at night and daytime napping.

Results

Self‐reported short nighttime sleep duration and daytime sleep of longer than 1 hour were associated with preexisting CVD, breathlessness, depression, poor health, physical inactivity, and manual social class. In all men, self‐reported daytime sleep of longer than 1 hour duration was associated with significantly greater risk of HF after adjustment for potential confounders (adjusted hazard ratio (aHR) = 1.69, 95% CI = 1.06–2.71) than in those who reported no daytime napping. Self‐reported nighttime sleep duration was not associated with HF risk except in men with preexisting CVD (<6 hours: aHR = 2.91, 95% CI = 1.31–6.45; 6 hours: aHR = 1.89, 95% CI = 0.89–4.03; 8 hours: aHR = 1.29, 95% CI = 0.61–2.71; ≥9 hours: aHR = 1.80, 905% CI = 0.71–4.61 vs nighttime sleep of 7 hours). Snoring was not associated with HF risk.

Conclusion

Self‐reported daytime napping of longer than 1 hour is associated with greater risk of HF in older men. Self‐reported short sleep (<6 hours) in men with CVD is associated with particularly high risk of developing HF.