Correlations between sleep patterns and cardiovascular diseases in a Chinese middle-aged population

Causal Effects of Sleep Traits on Angina Pectoris: Mediation by Cardiovascular Risk Factors

Purpose

Angina pectoris (AP) is a major factor in heightened risk of cardiac arrest and has been previously linked to sleep patterns. It remains unclear if sleep traits play a role in the onset of AP. Our study aims to declare the causality of sleep traits on AP by Mendelian randomization (MR) analyses.

Methods

Genome-wide association study (GWAS) data of sleep traits (sleep duration, insomnia, nap during day, chronotype, getting up in morning, narcolepsy, snoring) were obtained from the UK Biobank. The AP datasets came from an analysis containing samples from the UK biobank, FinnGen, and BioBank Japan. The GWAS data of cardiovascular risk factors (hypertension, smoking, hyperlipidemia, type 2 diabetes mellitus (T2DM)) came from the FinnGen. Two-sample MR analyses were carried out to gain a general map of sleep traits, risk factors and AP, then a multivariable MR was performed and the effect of each factor was calculated.

Results

We discovered a positive association between nap, narcolepsy, insomnia and stable angina pectoris (SAP), while getting up in morning associated with SAP negatively. Adequate sleep duration related to a reduced risk of SAP and unstable angina pectoris (UAP). Hypertension and T2DM acted as complete mediators in the relationship of nap and SAP, with an effect value of 1.267 (95% CI = 1.178-1.363, P < 0.01) and 1.059 (95% CI = 1.000-1.120, P < 0.05), and the mediating proportion was 27.7% (P < 0.05) and 7.70% (P = 0.102).

Conclusion

Our study found that nap, narcolepsy, and insomnia increased the risk of SAP, with hypertension and T2DM mediating the causal relationship between nap and SAP. Getting up in the morning reduced the risk of SAP, while longer sleep duration lowered the risk of SAP and UAP. More evidences are required to clarify the roles of sleep traits and risk factors in AP.

Association Between Sleep Duration and Cardiovascular Disease Among Asian Americans

BACKGROUND

Cardiovascular disease (CVD) prevalence varies widely among Asian American adults. The American Heart Association added healthy sleep to its metrics to define ideal cardiovascular health. Little is known about the association between sleep and CVD prevalence among Asian subgroups. We aim to examine the association between suboptimal sleep duration and CVD risk prevalence among Asian American subgroups.

METHODS AND RESULTS

We used 2012 to 2018 National Health Interview Survey data to examine the association between suboptimal sleep duration and CVD prevalence. We included 6868 self-identifying Asian adults age >40 years (Asian Indian [n=1053], Chinese [n=1415], Filipino [n=1734], and Other Asian [n=2666] adults). Suboptimal sleep was defined as <7 or >9 hours per night. CVD was defined as self-reported stroke, heart attack, coronary artery disease, or angina. Logistic regression was used to calculate odds ratios and 95% CI to estimate the association between suboptimal sleep duration and CVD prevalence. Filipino and Other Asian participants with suboptimal sleep had the highest prevalence of CVD. Aggregated Asian American participants with suboptimal sleep duration had a higher prevalence of CVD (odds ratio [95% CI, 1.35 [1.09-1.68]) compared with those with optimal sleep duration. After stratification by race or ethnicity or both, a significant association persisted for Other Asian participants (1.77 [95% CI, 1.27-2.46]) but not among all other Asian American subgroups.

CONCLUSIONS

Our study highlights the heterogeneity of CVD prevalence associated with suboptimal sleep duration among Asian American adults. Future studies should consider how different measures of sleep duration and quality affect CVD outcomes among disaggregated Asian American subgroups.

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.

Daytime napping and coronary heart disease risk in adults: a systematic review and dose-response meta-analysis

PURPOSE

The present study investigated the association between daytime napping and coronary heart disease (CHD) risk among adults.

METHODS

Articles were detected by using PubMed, ISI Web of Science, and Scopus databases until November 8th, 2021. The relevant data were found among the eight included articles and were pooled for meta-analysis in adult participants via a random-effects model.

RESULTS

Among 167,025 adults, the results revealed that daytime napping was associated with an enhanced risk of CHD (risk ratios [RR] = 1.30; 95% CI: 1.06, 1.60; p < 0.001). Subgroup analysis by daytime napping duration also indicated that daytime napping for at least 1 h had three times higher influence on the enhanced risk of CHD (RR = 1.34; 95% CI: 1.14, 1.58; p < 0.001) than that of daytime napping for less than 1 h (RR = 1.10; 95% CI: 1.02, 1.19; p = 0.014). In addition, subgroup analysis by region illustrated that daytime napping was linked with an enhanced risk of CHD in Chinese (RR = 1.41; 95% CI: 1.19, 1.66; p < 0.001), but not in European or American populations. Furthermore, the subgroup analysis of napping duration and risk of CHD suggested that their relation was significant just in those studies that controlled for depressive symptoms (RR = 1.52; 95% CI: 1.29, 1.80; p < 0.001, n = 3) and night sleep duration (RR = 1.42; 95% CI: 1.21, 1.66; p < 0.001, n = 5). The linear dose-response meta-analysis revealed that each 15-min increase in daytime napping was related with a 5% higher risk of CHD (RR = 1.05; 95% CI: 1.02, 1.08; I2 = 58.7%; p < 0.001). Furthermore, nonlinear dose-response meta-analysis revealed a positive linear relationship between daytime napping and CHD risk in adults (p nonlinearity = 0.484, p dose-response = 0.003).

CONCLUSION

Results showed that daytime napping was related with an increased risk of CHD in adults. The evidence from this study suggests that the public should be made conscious of the adverse outcomes of long daytime napping for CHD, notably among the Chinese population. Additional studies are required to confirm potential links between CHD risk and daytime napping.

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.

Attitudes and knowledge of nurses working at night and sleep promotion in nursing home residents: multicenter cross-sectional survey

BACKGROUND

Sleep disturbances are common in nursing home residents and challenging for their nurses. Knowledge about sleep and sleep promoting factors is essential to provide adequate sleep management, where nurses play a key role. Therefore, nurses' knowledge and attitudes towards sleep and sleep promoting interventions is important as enabling or inhibiting factor for successful sleep management.

METHODS

A multicenter cross-sectional study was conducted among nurses working wholly or partially at night in nursing homes in Germany. Data were collected between February and April 2021 via online or paper and pencil questionnaires, comprising 56 items. Nursing homes were recruited through existing cooperation with the study centers as well as via nursing home registers.

RESULTS

Finally, 138 nursing homes participated and 271 nurses completed the survey. Nurses agreed that sleep disturbances are an important topic with important impact on resident' health. Although, the assessment of sleep was seen as nurses' responsibility, only 40 nurses (14.7%) stated that residents' sleep was always documented. Only 21.7% reported the availability of policy documents providing guidance regarding the management of sleep disturbances. The vast majority (93.2%) reported never having received training about sleep and management of sleep disturbances after their basic nursing training.

CONCLUSIONS

Our results indicate that nurses working at night can play an important role in residents' sleep promotion. The findings indicate nurses' educational needs regarding sleep and sleep promotion. Nursing homes should implement institutional guidelines in order to promote residents' sleep based on adequate evidence-based non-pharmacological interventions.

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.

Association of heart rate with cardiovascular events and mortality in hypertensive and normotensive population: a nationwide prospective cohort study

Background

Cardiovascular disease is the leading cause of death worldwide. We assessed the association of baseline heart rate with cardiovascular events and mortality in hypertensive and normotensive populations using a prospective urban and rural epidemiology cohort study in China.

Methods

A total of 29,554 individuals were involved in our analysis, distributed equally between groups of normotensive and hypertensive. The primary outcomes were myocardial infarction, stroke, major cardiovascular diseases, and cardiovascular mortality. Cox frailty models were utilized to estimate hazard ratios for cardiovascular outcomes, and restricted cubic splines were used to explore the shape of the association between baseline heart rate and cardiovascular mortality.

Results

During a total observational time of 230,813 person-years, 402 myocardial infarction events, 1,096 stroke events, 1,540 major cardiovascular events, and 356 cardiovascular deaths were documented. In adjusted analyses, normotensive subjects with baseline heart rate >82.5 beats per minute had a 3.30-fold greater risk of cardiovascular death and an increased 72% risk of myocardial infarction, compared with individuals whose baseline heart rate was 65.5-71 beats per minute. A similar trend was observed for cardiovascular mortality in the hypertensive population, but the association was attenuated. Multivariable-adjusted restricted cubic splines showed linear associations between baseline heart rate and cardiovascular mortality in two groups of people (all P<0.05 for linearity).

Conclusions

Elevated baseline heart rate is associated with an increased risk of cardiovascular mortality and myocardial infarction in the normotensive population. The association is attenuated for cardiovascular death in hypertensive patients.

Association of estimated sleep duration and naps with mortality and cardiovascular events: a study of 116 632 people from 21 countries

AIMS

To investigate the association of estimated total daily sleep duration and daytime nap duration with deaths and major cardiovascular events.

METHODS AND RESULTS

We estimated the durations of total daily sleep and daytime naps based on the amount of time in bed and self-reported napping time and examined the associations between them and the composite outcome of deaths and major cardiovascular events in 116 632 participants from seven regions. After a median follow-up of 7.8 years, we recorded 4381 deaths and 4365 major cardiovascular events. It showed both shorter (≤6 h/day) and longer (>8 h/day) estimated total sleep durations were associated with an increased risk of the composite outcome when adjusted for age and sex. After adjustment for demographic characteristics, lifestyle behaviours and health status, a J-shaped association was observed. Compared with sleeping 6-8 h/day, those who slept ≤6 h/day had a non-significant trend for increased risk of the composite outcome [hazard ratio (HR), 1.09; 95% confidence interval, 0.99-1.20]. As estimated sleep duration increased, we also noticed a significant trend for a greater risk of the composite outcome [HR of 1.05 (0.99-1.12), 1.17 (1.09-1.25), and 1.41 (1.30-1.53) for 8-9 h/day, 9-10 h/day, and >10 h/day, Ptrend < 0.0001, respectively]. The results were similar for each of all-cause mortality and major cardiovascular events. Daytime nap duration was associated with an increased risk of the composite events in those with over 6 h of nocturnal sleep duration, but not in shorter nocturnal sleepers (≤6 h).

CONCLUSION

Estimated total sleep duration of 6-8 h per day is associated with the lowest risk of deaths and major cardiovascular events. Daytime napping is associated with increased risks of major cardiovascular events and deaths in those with >6 h of nighttime sleep but not in those sleeping ≤6 h/night.

Association of daytime napping with incident stroke in middle-aged and older adults: a large community-based study

BACKGROUND AND PURPOSE

There are conflicting reports on the association between daytime napping and incident stroke. This study was designed to investigate the relationship between daytime napping and stroke within a community-based cohort.

METHODS

The present prospective study was based on the Sleep Heart Health Study. Napping habits were assessed with a self-reported Sleep Habits Questionnaire. Participants with napping habits of different durations and frequencies were followed up until the first stroke occurred or the final censoring date. Cox proportional hazards models were used to estimate the relationship between napping habits and stroke.

RESULTS

A total of 4757 participants (2219 men, mean age 63.6 ± 11.1 years) were enrolled in this study. Compared with those taking no naps, multivariate proportional hazards models analysis indicated that individuals taking naps with a duration of >60 min [hazard ratio (HR), 2.460; 95% confidence interval (CI), 1.538-3.934] had a higher risk of stroke. There was also an increased risk of stroke among participants taking naps daily (HR, 1.563; 95% CI, 1.059-2.307) or five to six times/week (HR, 1.548; 95% CI, 1.026-2.335). After combining napping durations and frequencies, regular long naps (HR, 1.903; 95% CI, 1.182-3.065) and regular short naps (HR, 1.451; 95% CI, 1.010-2.084) were independent risk factors for incident stroke.

CONCLUSION

Daytime napping with a long duration (>30 min) or a high frequency (≥5 times/week) may increase the risk of stroke.

Effects of physical and mind-body exercise on sleep problems during and after breast cancer treatment: a systematic review and meta-analysis

PURPOSE

We conducted a meta-analysis evaluating the effects of different exercise interventions on self-reported and objective sleep measurements during or after breast cancer treatment.

METHODS

Three databases were systematically searched for randomized controlled trials with any type of exercise intervention in women with breast cancer. Outcomes were self-reported or objective sleep measurements. Standardized mean differences (SMDs) were calculated using random-effects models.

RESULTS

The meta-analysis included 22 trials with 2107 participants. Of these, 17 studies used the Pittsburgh Sleep Quality Index (PSQI), six studies included objective sleep assessments (ActiGraph). Physical exercise interventions included walking, aerobic exercise, resistance exercise or a combination of both. Mind-body exercise interventions included yoga, Tai Chi and Qigong. Most interventions were supervised. Both, physical (SMD - 0.32; 95% CI - 0.54 to - 0.10) and mind-body exercise interventions (SMD - 0.27; 95% CI - 0.44 to - 0.09), resulted in improvements of total sleep scores. Subgroup analyses revealed no clear differences between interventions conducted during versus after breast cancer treatment. Considering the PSQI subscales, exercise resulted in improvements of sleep quality (SMD - 0.28; 95% CI - 0.44 to - 0.11) and sleep disturbances (SMD - 0.26; 95% CI - 0.45 to - 0.06). Regarding the objective measurements, no significant effects were found.

CONCLUSIONS

Physical as well as mind-body exercise can improve subjective sleep problems in breast cancer patients. In contrast, there was no effect of exercise on objective sleep measures. Future studies should clarify which type of intervention might be most effective depending on individual patients' and treatments' characteristics.

Napping, functional capacity and satisfaction with life in older adults: A population-based study

AIM AND OBJECTIVE

To analyse the association between napping, functional capacity and satisfaction with life in older adult residing in the community.

METHOD

A cross-sectional population-based study using data from a health survey conducted in a city of the state of São Paulo. Information on sociodemographic and clinical variables was collected through a questionnaire, as well as the occurrence or not of napping and satisfaction with life. Functional capacity was assessed using the Katz Index and Lawton-Brody Scale. Statistical analysis was performed using the Rao-Scott chi-square test and a hierarchical analysis using stepwise backward multiple Poisson regression. p-Values <0.05 were considered significant. In this paper, we adhere to STrengthening the Reporting of OBservational studies in Epidemiology guidelines.

RESULTS

There was predominance of the 60-69 years age group (51.3%) and of females (60.8%). The majority of the older adults (57.5%), of both sexes, reported napping. A higher prevalence of napping was found in the older subjects, the male sex, the subjects without children, those with health problems and those that were partially dependent in instrumental activities of daily living.

CONCLUSIONS

The study showed that naps are prevalent in older adults. The need to identify the issues that permeate napping is emphasised, in order to promote health in individuals of this age group, before classifying the practice as beneficial or harmful.

RELEVANCE TO CLINICAL PRACTICE

It is essential that health professionals, in their practices, consider the complaints and reports of naps in the elderly, in an attempt to detect and reduce possible consequences in activities of daily living.

Sleep disorders in the elderly: a growing challenge

In contrast to newborns, who spend 16-20 h in sleep each day, adults need only about sleep daily. However, many elderly may struggle to obtain those 8 h in one block. In addition to changes in sleep duration, sleep patterns change as age progresses. Like the physical changes that occur during old age, an alteration in sleep pattern is also a part of the normal ageing process. As people age, they tend to have a harder time falling asleep and more trouble staying asleep. Older people spend more time in the lighter stages of sleep than in deep sleep. As the circadian mechanism in older people becomes less efficient, their sleep schedule is shifted forward. Even when they manage to obtain 7 or 8 h sleep, they wake up early, as they have gone to sleep quite early. The prevalence of sleep disorders is higher among older adults. Loud snoring, which is more common in the elderly, can be a symptom of obstructive sleep apnoea, which puts a person at risk for cardiovascular diseases, headaches, memory loss, and depression. Restless legs syndrome and periodic limb movement disorder that disrupt sleep are more prevalent in older persons. Other common medical problems of old age such as hypertension diabetes mellitus, renal failure, respiratory diseases such as asthma, immune disorders, gastroesophageal reflux disease, physical disability, dementia, pain, depression, and anxiety are all associated with sleep disturbances.