Short sleep duration as an independent predictor of cardiovascular events in Japanese patients with hypertension

Determinants of unhealthy sleeping habits among Belgian university students: an application of the Theory of Planned Behavior

Objectives: This study investigated if unhealthy sleeping habits of university students can be explained by the Theory of Planned Behavior. Method: An online questionnaire was administered to 1006 undergraduate students at a Belgian university to measure their frequency of irregular sleeping times, daytime napping, and pre-bedtime alcohol or internet use, as well as the attitudes, perceived norms, perceived control and intentions for these behaviors. Results: Principal Component Analysis and internal consistency analysis confirmed the validity and reliability of the scales measuring the TPB dimensions. Expected outcomes, perceived norms and perceived control significantly explained intentions to avoid irregular sleeping times, daytime naps, pre-bedtime activity and pre-bedtime alcohol use. Intentions and perceived behavioral control explained self-reported irregular sleeping times, daytime napping, pre-bedtime activity, and pre-bedtime alcohol use. Significant differences in predictions were found for gender, study program, type of residence and age. Conclusions: The TPB provides a useful theoretical framework to explain students' sleeping behaviors.

The Effect of Sleep Quality on Coronary Lesion Severity and Prognosis in the Young Acute Coronary Syndrome Population

This study aimed to explore the effect of long-term (≥1 year) sleep quality on coronary lesion complexity and cardiovascular prognosis in young acute coronary syndrome (ACS) patients. We consecutively recruited young patients aged from 18 to 44 years old with first-episode ACS and significant epicardial stenosis on coronary angiography from January 2016 to January 2017. Coronary lesion complexity was evaluated based on SYNTAX scores. Long-term sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) (PSQI ≤ 5 and PSQI > 5 groups). The primary endpoints were major adverse cardiovascular events (MACEs). A total of 466 young ACS patients (93.13% male; median age, 41 years) were included. Poor sleepers (PSQI > 5) had higher SYNTAX scores. After adjusting for confounders, PSQI scores (continuous variables, OR: 1.264; 95%CI: 1.166-1.371; p < 0.001) and PSQI grade (binary variable, OR: 3.864; 95%CI: 2.313-6.394; p = 0.001) were significantly associated with an increased risk of complex coronary lesions. During a median follow-up of 74 months, long-term poor sleep quality (PSQI > 5) was significantly associated with an increased risk of MACEs (HR: 4.266; 95%CI: 2.274-8.001; p < 0.001). Long-term poor sleep quality was a risk factor for complex coronary lesions and has adverse effects on cardiovascular prognosis in the young ACS population.

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.

Adaptive Solutions to the Problem of Vulnerability During Sleep

Sleep is a behavioral state whose quantity and quality represent a trade-off between the costs and benefits this state provides versus the costs and benefits of wakefulness. Like many species, we humans are particularly vulnerable during sleep because of our reduced ability to monitor the external environment for nighttime predators and other environmental dangers. A number of variations in sleep characteristics may have evolved over the course of human history to reduce this vulnerability, at both the individual and group level. The goals of this interdisciplinary review paper are (1) to explore a number of biological/instinctual features of sleep that may have adaptive utility in terms of enhancing the detection of external threats, and (2) to consider relatively recent cultural developments that improve vigilance and reduce vulnerability during sleep and the nighttime. This paper will also discuss possible benefits of the proposed adaptations beyond vigilance, as well as the potential costs associated with each of these proposed adaptations. Finally, testable hypotheses will be presented to evaluate the validity of these proposed adaptations.

Adherence to a Healthy Sleep Pattern and Incidence of Cardiometabolic Multimorbidity Among Hypertensive Patients: A Prospective Study of UK Biobank

Study Objectives

To investigate whether a healthy sleep pattern would reduce the risk of cardiometabolic multimorbidity (CMM) among hypertensives.

Methods

This is a prospective cohort analysis from the UK Biobank. A total of 69 524 hypertensives without a history of diabetes mellitus, coronary heart disease, or stroke at baseline were enrolled. Five dimensions of healthy sleep at baseline including early chronotype, sleep 7–8 h/d, free of insomnia, no snoring, and no frequent excessive daytime sleepiness were used to generate a healthy sleep score ranging from 0 to 5 (one point was given for each dimension of healthy sleep). A higher score indicated a healthier sleep pattern. We set five groups corresponding to the healthy sleep score of 5, 4, 3, 2, and 0–1, respectively. The primary outcome was the incidence of overall CMM among enrolled hypertensives. We assessed the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) by Fine-Gray subdistribution hazard models.

Results

We found the full-adjusted HR (95% CI) for overall CMM was 0.93 (0.91–0.95) for a 1-point increase in the healthy sleep score. Compared to hypertensives with a healthy sleep score of 0–1, those with a score of 5 had a 27% lower risk of overall CMM, and 37%, 23%, and 20% lower risks of diabetes mellitus, coronary heart disease, and stroke, respectively, after adjusting for sociodemographic characteristic, lifestyle, and clinical factors.

Conclusions

Our results indicated that a healthy sleep pattern was associated with lower risks of CMM outcomes among hypertensives.

Distinct Relevance of Nightly Sleep Duration to Metabolic, Anthropometric, and Lifestyle Factors in Patients with Type 2 Diabetes

Objective Although a number of studies have shown that both short and long sleep durations were associated with the risk of metabolic disorders related to obesity, the underlying mechanism is still not fully understood. In this study, we analyzed the association of sleep duration with metabolic, anthropometric, and lifestyle factors in patients with type 2 diabetes. Methods The subjects were 279 patients with type 2 diabetes 63 (52-70) years old (median and interquartile range) with a body mass index of 25.0 (22.2-28.3) kg/m² and HbA1c levels of 8.7% (7.6-10.3%). Patients with advanced complications were excluded from the study. Diets were evaluated by registered dietitians using a software program. Body composition was assessed by the multifrequency bioelectrical impedance method. Results The mean self-reported nightly sleep duration was 6.4 hours with no marked gender difference. Sleep duration was inversely correlated with the HbA1c levels, total energy intake, and intakes of carbohydrate, protein, and fat. The body fat ratio and skeletal muscle mass were correlated positively and negatively, respectively, with sleep duration. When the subjects were divided into three groups based on sleep duration, the intakes of total energy, carbohydrates, and fat tended to be high in those with <5.5 hours of sleep, and the percentage of patients who had habitual physical activities was lower in those with >7 hours of sleep. Conclusion The observation that sleep duration is distinctly associated with excessive eating and a sedentary lifestyle may provide a basis for effective lifestyle management of patients with type 2 diabetes.

Long sleep duration and risk of increased arterial stiffness in a Chinese population

To examine the relationship between self-reported sleep duration and arterial stiffness in a large Chinese population from Kailuan.From July 2010 to December 2015, a total of 17,018 participants aged 18 to 98 years were enrolled after excluding those with a history of cerebrovascular events and coronary artery disease. Participants were divided into 5 categories according to self-reported night sleep duration: ≤5.0, 6.0, 7 (ref), 8, and ≥9.0 hours. A brachial-ankle pulse wave velocity ≥1400 cm/s was considered to represent arterial stiffness. Multivariate logistic regression models were used to calculate the odds ratio (OR) and confidence interval (CI) for arterial stiffness according to the sleep duration.Using 7 hours of sleep as the reference group, the multivariable adjusted ORs (95% CI) for arterial stiffness were 1.00 (0.87-1.16), 1.00 (0.90-1.11), 1.0 (ref), 1.03 (0.93-1.14), and 1.48 (1.05-2.08) from the lowest to highest category of sleep duration, respectively. Secondary analysis showed no evidence of interactions between sleep duration and age/sex on the risk of arterial stiffness (P-interaction = .390/.198).A long night sleep duration was associated with increased arterial stiffness.

Nocturnal blood pressure measured by home devices: evidence and perspective for clinical application

: Studies using ambulatory blood pressure (BP) monitoring have shown that BP during night-time sleep is a stronger predictor of cardiovascular outcomes than daytime ambulatory or conventional office BP. However, night-time ambulatory BP recordings may interfere with sleep quality because of the device cuff inflation and frequency of measurements. Hence, there is an unmet need for obtaining high quality BP values during sleep. In the last two decades, technological development of home BP devices enabled automated BP measurements during night-time. Preliminary data suggest that nocturnal home BP measurements yield similar BP values and show good agreement in detecting nondippers when compared with ambulatory BP monitoring. Thus, nocturnal home BP measurements might be a reliable and practical alternative to ambulatory BP monitoring to evaluate BP during sleep. As the use of home BP devices is widespread, well accepted by users and has relatively low cost, it may prove to be more feasible and widely available for routine clinical assessment of nocturnal BP. At present, however, data on the prognostic relevance of nocturnal BP measured by home devices, the optimal measurement schedule, and other methodological issues are lacking and await further investigation. This article offers a systematic review of the current evidence on nocturnal home BP, highlights the remaining research questions, and provides preliminary recommendations for application of this novel approach in BP management.

Short sleep is associated with higher prevalence and increased predicted risk of cardiovascular diseases in an Iranian population: Fasa PERSIAN Cohort Study

Cardiovascular disease (CVD) is the leading cause of death worldwide. One common factor that may affect CVD risk factors is sleep disturbance. The factors influencing an individual's sleep may vary among different cultures. The current study investigated sleep quality and quantity in the Fasa cohort population as an Iranian population. In a cross-sectional study using the Fasa PERSIAN cohort study data, 10,129 subjects aged 35-70 were entered. Self-reported sleep duration and cardiovascular events were recorded. The Framingham risk score (FRS) is used to predict cardiovascular events. Adjusted logistic regression showed significant odds ratios in subjects who sleep less than 6 hours for CVD (OR = 1.23; 95% CI:1.03-1.48), coronary heart disease (CHD) (OR = 1.21; 95% CI:1.009-1.46), and hypertension (HTN) (OR = 1.37; 95% CI:1.16-1.62). Higher risk profiles were also seen in the FRS for short sleepers. The highest significant odds ratios in FRS profiles in the intermediate high-risk group compared with the low-risk group were (1.44; 95% CI:1.18-1.75) in CVD and (1.48; 95% CI:1.16-1.88) in CHD risk score profiles. It can be suggested that participants with short durations of sleep had significantly higher CVD, HTN prevalence, and 10-year FRS. Participants with long sleep durations had no increase in CVD, CHD, myocardial infarction (MI), or HTN prevalence. MI prevalence was at the lowest level in subjects who got 8 to 8.9 hours of sleep.

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

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

Sleep duration and risk of all-cause mortality: a systematic review and meta-analysis

AIMS

To determine the association between the sleep duration and the risk of all-cause mortality in adults.

METHODS

A search strategy was conducted in the MEDLINE, CENTRAL, EMBASE and LILACS databases. Searches were also conducted in other databases and unpublished literature. Cohort studies were included without language, time or setting restrictions. The risk of bias was evaluated with a modified Cochrane Collaboration's tool. An analysis of random effects was conducted. The primary outcome was all-cause mortality. The measure of the effect was the risk difference (RD) with a 95% confidence interval (CI). The planned comparisons were 7-9 h of sleep v. <7 h and the same reference v. >9 h.

RESULTS

Thirty-nine studies were included in our qualitative analysis, regarding the quantitative analysis, 19 studies were included in <7 v. 7-9 h analysis, and 18 studies in the >9 v. 7-9 h. A low risk of bias was shown for most of the study items. The overall RD for all-cause mortality was 0.09 (95% CI 0.07-0.11) favouring the >9 h group compared with our reference. In contrast, no differences were found between the <7 h and the reference sleep duration groups (RD 0.00, 95% CI 0.00-0.01).

CONCLUSION

We found a probable association of long sleep duration and higher mortality; however, it could reflect an underlying systemic or neurological disease that cause sleep fragmentation, deterioration in quality and micro-awakenings.

Expert panel consensus recommendations for ambulatory blood pressure monitoring in Asia: The HOPE Asia Network

Hypertension is an important public health issue because of its association with a number of significant diseases and adverse outcomes. However, there are important ethnic differences in the pathogenesis and cardio-/cerebrovascular consequences of hypertension. Given the large populations and rapidly aging demographic in Asian regions, optimal strategies to diagnose and manage hypertension are of high importance. Ambulatory blood pressure monitoring (ABPM) is an important out-of-office blood pressure (BP) measurement tool that should play a central role in hypertension detection and management. The use of ABPM is particularly important in Asia due to the specific features of hypertension in Asian patients, including a high prevalence of masked hypertension, disrupted BP variability with marked morning BP surge, and nocturnal hypertension. This HOPE Asia Network document summarizes region-specific literature on the relationship between ABPM parameters and cardiovascular risk and target organ damage, providing a rationale for consensus-based recommendations on the use of ABPM in Asia. The aim of these recommendations is to guide and improve clinical practice to facilitate optimal BP monitoring with the goal of optimizing patient management and expediting the efficient allocation of treatment and health care resources. This should contribute to the HOPE Asia Network mission of improving the management of hypertension and organ protection toward achieving "zero" cardiovascular events in Asia.

Association between sleep duration and hypertension: Isfahan Healthy Heart Program, Iran

BACKGROUND

Hypertension (HTN) is an important risk factor for atherosclerotic and non-atherosclerotic cardiovascular disease (CVD). HTN increases risk of stroke and diabetes complications and at the end stage renal disease. Sleep disorders including short sleep duration are involved in pathogenesis of HTN. This study aimed to examine the association between self-reported sleep duration and HTN in a group of adult population in Isfahan City, Iran.

METHODS

This cross-sectional survey was performed as part of the Isfahan Healthy Heart Program (IHHP). A total of 12492 individuals aged over 19 years (6110 men and 6382 women) entered the study. Sleep duration was recorded according to subjects' self-report. HTN was defined as a systolic blood pressure (SBP) of ≥ 140 mmHg, a diastolic blood pressure (DBP) of ≥ 90 mmHg, or use of antihypertensive medication. The relation between sleep hours and HTN was examined using multiple logistic regression in three models, unadjusted, adjusted according to age and sex, and adjusted according to age, sex, body mass index (BMI), and waist circumference (WC).

RESULTS

Sleeping time less than 5 hours, in comparison to sleep duration of 7-8 hours per night,was associated with a higher risk of HTN [odds ratio (OR) = 2.52, 95% confidence interval (CI): 2.17-2.93]. This association remained significant even after adjustment for age, sex, BMI, and WC (OR = 1.38, 95% CI: 1.16-1.64). Sleep duration over 9 hours had a negative association with risk of HTN among those under 60 years old (OR = 0.63, 95% CI: 0.47-0.86).

CONCLUSION

Sleep duration less than 5 hours is positively associated with HTN. It seems that sleep duration might affect HTN and atherosclerotic CVD.

Associations of sleep duration with cardiometabolic outcomes in American Indians and Alaska Natives and other race/ethnicities: results from the BRFSS

OBJECTIVES

This study assessed the associations between short and long sleep duration and prevalence of cardiometabolic outcomes in American Indians and Alaska Natives (AI/ANs) and compared these associations to those evident among other race/ethnicities.

METHODS

We analyzed data from the 2013-2014 Behavioral Risk Factor Surveillance System. In total, 14,536 AI/ANs, 729,962 non-Hispanic whites, 71,765 blacks, and 59,472 Hispanics were included. Logistic regressions were conducted to compute unadjusted and adjusted odds ratios (OR) for the associations of interest.

RESULTS

Among AI/ANs, 38.6% reported sleeping <7 hours per night (short sleepers) while 39.3% reported 8+ hours of sleep (long sleepers). After adjusting for age and gender, both short and long sleep durations were associated with higher odds of reporting diabetes, stroke, coronary heart disease and heart attack in almost all race/ethnic groups. After multiple adjustments, the sleep-diabetes association was more pronounced (OR = 1.71 and OR = 1.56 for short and long sleepers, respectively) among AI/ANs than other race/ethnicities.

CONCLUSIONS

Future studies are warranted to examine race/ethnic variability in the association between sleep duration and cardiometabolic outcomes.

Capturing sleep-wake cycles by using day-to-day smartphone touchscreen interactions

Body movements drop with sleep, and this behavioural signature is widely exploited to infer sleep duration. However, a reduction in body movements may also occur in periods of intense cognitive activity, and the ubiquitous use of smartphones may capture these wakeful periods otherwise hidden in the standard measures of sleep. Here, we continuously captured the gross body movements using standard wrist-worn accelerometers to quantify sleep (actigraphy) and logged the timing of the day-to-day touchscreen events (‘tappigraphy’). Using these measures, we addressed how the gross body movements overlap with the cognitively engaging digital behaviour (from n = 79 individuals, accumulating ~1400 nights). We find that smartphone use was distributed across a broad spectrum of physical activity levels, but consistently peaked at rest. We estimated the putative sleep onset and wake-up times from the actigraphy data to find that these times were well correlated to the estimates from tappigraphy (R² = 0.9 for sleep-onset time and wake-up time). However, actigraphy overestimated sleep as virtually all of the users used their phones during the putative sleep period. Interestingly, the probability of touches remained greater than zero for ~2 h after the putative sleep onset, and ~2 h before the putative wake-up time. Our findings suggest that touchscreen interactions are widely integrated into modern sleeping habits—surrounding both sleep onset and waking-up periods—yielding a new approach to measuring sleep. Smartphone interactions can be leveraged to update the behavioural signatures of sleep with these peculiarities of modern digital behaviour.

Short Sleep Duration as a Risk Factor of Cardiovascular Disease in Korean Adults: Secondary Analysis of the Fifth Korean National Health and Nutrition Examination Survey

BACKGROUND

Sleep durations shorter or longer than 7 h are associated with cardiovascular diseases. We aimed to investigate the association among sleep duration, risk factors of hypertension, and cardiovascular disease in South Korea using data from a recent large-scale survey.

METHODS

Data produced by the Korea National Health and Nutrition Examination Survey (KNHANES) were subjected to multivariate logistic analysis. This cross-sectional, nationally representative survey was conducted from Jan 1 to Dec 31, 2011, by the Korean Center for Disease Control and Prevention. Overall, 6,466 participated. Data were analyzed using STATA version 13.0 (STATA Corp LP).

RESULTS

The participants' socioeconomic, physical, and lifestyle factors were statistically different between the two age groups (<65 yr and ≥65 yr). Shorter sleep durations were associated with hypertension in individuals younger than 65 yr of age. On the other hand, in participants aged ≥65 yr, both shorter and longer sleep durations were associated with hypertension, while shorter sleep durations were associated with cardiovascular diseases.

CONCLUSION

Unusual sleep durations are associated with an increased prevalence of cardiovascular disease among Korean adults. The effect of sleep duration appears to be more significant in individuals with hypertension, suggesting that the management of hypertension should be prioritized in patients older than 65 year.

Association between sleep duration and electrocardiographic ischemic changes in middle-aged population: Isfahan Healthy Heart Program

BACKGROUND

Recent studies examining the association between sleep duration and cardiovascular disease (CVD) showed inconsistent results. The aim of our study was to evaluate the association between self-reported night sleep duration and ischemic changes in electrocardiography (ECG).

METHODS

We conducted this cross-sectional study on 3513 participants from Iranian middle-aged population as a part of Isfahan Healthy Heart Program (IHHP), Isfahan, Iran. Sleep duration was obtained by questioning participants. The frequency of electrocardiographic ischemic changes was calculated using ECG Minnesota coding system.

RESULTS

Short sleep duration was associated with increased frequency of electrocardiographic ischemic changes. In a fully adjusted multiple logistic regression analysis, the odds ratio (OR) for short sleep duration less than 5 hours per night was 1.501 [95% confidence interval (CI) for OR: 1.085-2.076] compared to 8 hours of sleep. After stratifying the study population into sex groups, the association remained significant only in women. The OR for short sleep less than 5 hours per night was 1.565 (95% CI for OR: 1.052-2.329) and 1.455 (95% CI for OR: 0.833-2.539) in women and men, respectively. There was no association between long sleep duration and electrocardiographic ischemic changes in men and women.

CONCLUSION

We concluded that there is a positive association between short sleep duration and frequency of electrocardiographic ischemic changes in middle-aged women. This association suggests that short sleep duration may increase the risk of ischemic heart disease (IHD) in women, and this need to be evaluated in further studies.

Short Sleep Duration, Obstructive Sleep Apnea, Shiftwork, and the Risk of Adverse Cardiovascular Events in Patients After an Acute Coronary Syndrome

BACKGROUND

It is unknown whether short sleep duration, obstructive sleep apnea, and overnight shift work are associated with the risk of recurrent cardiovascular events in patients after an acute coronary syndrome.

METHODS AND RESULTS

SOLID-TIMI 52 (The Stabilization of PLaques UsIng Darapladib-Thrombolysis in Myocardial Infarction 52 Trial) was a multinational, double-blind, placebo-controlled trial that enrolled 13 026 patients ≤30 days of acute coronary syndrome. At baseline, all patients were to complete the Berlin questionnaire to assess risk of obstructive sleep apnea and a sleep and shift work survey. Median follow-up was 2.5 years. The primary outcome was major coronary events (MCE; coronary heart disease death, myocardial infarction, or urgent revascularization). Cox models were adjusted for clinical predictors. Patients who reported <6 hours sleep per night had a 29% higher risk of MCE (adjusted hazard ratio, 1.29; 95% confidence interval, 1.12-1.49; P<0.001) compared with those with longer sleep. Patients who screened positive for obstructive sleep apnea had a 12% higher risk of MCE (1.12; 1.00-1.24; P=0.04) than those who did not screen positive. Overnight shift work (≥3 night shifts/week for ≥1 year) was associated with a 15% higher risk of MCE (1.15; 1.03-1.29; P=0.01). A step-wise increase in cardiovascular risk was observed for individuals with more than 1 sleep-related risk factor. Individuals with all 3 sleep-related risk factors had a 2-fold higher risk of MCE (2.01; 1.49-2.71; P<0.0001).

CONCLUSIONS

Short sleep duration, obstructive sleep apnea, and overnight shift work are under-recognized as predictors of adverse outcomes after acute coronary syndrome. Increased efforts should be made to identify, treat, and educate patients about the importance of sleep for the potential prevention of cardiovascular events.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01000727.

Inverse Relationship between Sleep Duration and Cardio-Ankle Vascular Index in Children

AIM

Poor sleep has been shown to be associated with the development of cardiovascular risk factors, such as obesity, in both adults and children. This study aimed to investigate the relationship between sleep duration and arterial stiffness indices in Japanese children and early adolescents.

METHODS

The data on 102 students (56 males, 46 females; mean age, 11.9±1.8 years) were analyzed. As non-invasive arterial stiffness parameters, the cardio-ankle vascular index (CAVI) and heart-ankle pulse wave velocity (haPWV) were evaluated. Their students' sleep habits (bedtime and wake times on a usual weekday) were investigated using questionnaires, and based on these, their sleep durations were calculated.

RESULTS

The CAVI values in the males and females were 4.8±0.9 and 4.7±0.9 (arbitrary unit), respectively. haPWV values in the males and females were 5.5±0.6 and 5.4±0.6 m/s, respectively. Sleep duration in the males, but not in the females, was negatively correlated with CAVI (r=－0.356) and haPWV (r=－0.356), suggesting that students with short sleep duration could have increased arterial stiffness. After adjusting for confounders, such as age, sex, systolic blood pressure, heart rate, adiposity, and physical fitness, the correlation of sleep duration with CAVI, but not with haPWV, was still significant (partial r=－0.253, p＜0.05).

CONCLUSION

Our findings suggest that shorter sleep duration influences arterial stiffening even in childhood.

Cardiac autonomic control and complexity during sleep are preserved after chronic sleep restriction in healthy subjects

Acute sleep deprivation (SD) alters cardiovascular autonomic control (CAC) and is associated with an increased risk of cardiovascular disorders. However, the effects of partial SD on CAC are unclear. Thus, we aimed to investigate the effects of partial SD on CAC during sleep. We randomized seventeen healthy subjects to a restriction group (RES, n = 8, subjects slept two-thirds of normal sleep time based on individual habitual sleep duration for 8 days and 8 nights) or a Control group (CON, n = 9, subjects were allowed to sleep their usual sleep time). Attended polysomnographic (PSG) studies were performed every night; a subset of them was selected for the analysis at baseline (day 3-D3), the first night after sleep restriction (day 5-D5), at the end of sleep restriction period (day 11-D11), and at the end of recovery phase (day 14-D14). We extracted electrocardiogram (ECG) and respiration from the PSG and divided into wakefulness (W), nonrapid eye movements (REM) sleep (N2 and N3) and REM sleep. CAC was evaluated by means of linear spectral analysis, nonlinear symbolic analysis and complexity indexes. In both RES and CON groups, sympathetic modulation decreased and parasympathetic modulation increased during N2 and N3 compared to W and REM at D3, D5, D11, D14. Complexity analysis revealed a reduction in complexity during REM compared to NREM sleep in both DEP and CON After 8 days of moderate SD, cardiac autonomic dynamics, characterized by decreased sympathetic, and increased parasympathetic modulation, and higher cardiac complexity during NREM sleep, compared to W and REM, are preserved.

Sleep duration and smoking are associated with coronary heart disease among US adults with type 2 diabetes: Gender differences

AIMS

The associations of moderate alcohol consumption, sleep duration, and tobacco smoking with coronary heart disease (CHD) among patients with type 2 diabetes mellitus (T2D) are not clearly clarified. The aims of the study were to evaluate the associations of lifestyle factors, hypertension, obesity, depression and sleep duration with CHD development among patients with T2D, and particularly, to examine the gender differences in risk factors for CHD.

METHODS

A total of 2335 T2D adults were selected from the 2012 National Health Interview Survey. Weighted univariate and multiple logistic regression analyses were used to estimate the odds ratios with 95% confidence intervals.

RESULTS

The CHD prevalence among patients with T2D was 14.2% (18.1% and 10.4% for males and females, respectively), which increased with age (10.3% and 19.6% for age groups 18-64 and 65+, respectively). After adjusting for other factors, weighted logistic regression analyses showed that CHD among patients with T2D was significantly associated with being male, older age, past smoking, long sleep duration, hypertension, and high cholesterol level. Furthermore, the significant association of older age, past smoking, hypertension and high cholesterol level were observed particularly in males, while the association of long sleep duration with CHD was only observed in females. Hypertension was associated with CHD for both genders.

CONCLUSIONS

Gender, age, past smoking, long sleep duration, hypertension and high cholesterol level were significantly associated with CHD among T2D patients; however, such associations differed by gender. Such gender disparities should be considered in the prevention and treatment of T2D.

Women Who Sleep More Have Reduced Risk of Peptic Ulcer Disease; Korean National Health and Nutrition Examination Survey (2008-2009)

Sleep is integral to life and sleep duration is important in sleep quality, physical, and psychological health. Disturbances in sleep duration have been associated with increased risk of metabolic disorders, hypertension, and overall mortality. Sleep disturbance has also been linked with various gastrointestinal disorders. However, the association between sleep and peptic ulcer disease (PUD) has not been evaluated. We investigated the association between sleep duration and PUD. Subjects were included from the fifth Korean National Health and Nutrition Examination Survey conducted from 2008-2009. Individuals with PUD were defined as those with a physician diagnosis of PUD. Daily sleep duration was established by asking participants the amount of time that they slept per day. Multiple logistic regression models were used to evaluate the association of PUD and sleep duration. This study included 14,290 participants (8,209 women). The prevalence of PUD was 5.7% and was higher in men (6.8%) than in women (4.9%). Women who slept ≥9 hours were significantly less likely to have PUD compared to women who slept 7 hours. In men, longer sleep duration (≥9 hours) had a tendency toward PUD prevention. Our results suggest that longer sleep duration may play a protective role for PUD development.

Role of sleep quality in the metabolic syndrome

Emerging evidence has assigned an important role to sleep as a modulator of metabolic homeostasis. The impact of variations in sleep duration, sleep-disordered breathing, and chronotype to cardiometabolic function encompasses a wide array of perturbations spanning from obesity, insulin resistance, type 2 diabetes, the metabolic syndrome, and cardiovascular disease risk and mortality in both adults and children. Here, we critically and extensively review the published literature on such important issues and provide a comprehensive overview of the most salient pathophysiologic pathways underlying the links between sleep, sleep disorders, and cardiometabolic functioning.

Sleep Duration and Area-Level Deprivation in Twins

STUDY OBJECTIVES

We used quantitative genetic models to assess whether area-level deprivation as indicated by the Singh Index predicts shorter sleep duration and modifies its underlying genetic and environmental contributions.

METHODS

Participants were 4,218 adult twin pairs (2,377 monozygotic and 1,841 dizygotic) from the University of Washington Twin Registry. Participants self-reported habitual sleep duration. The Singh Index was determined by linking geocoding addresses to 17 indicators at the census-tract level using data from Census of Washington State and Census Tract Cartographic Boundary Files from 2000 and 2010. Data were analyzed using univariate and bivariate genetic decomposition and quantitative genetic interaction models that assessed A (additive genetics), C (common environment), and E (unique environment) main effects of the Singh Index on sleep duration and allowed the magnitude of residual ACE variance components in sleep duration to vary with the Index.

RESULTS

The sample had a mean age of 38.2 y (standard deviation [SD] = 18), and was predominantly female (62%) and Caucasian (91%). Mean sleep duration was 7.38 h (SD = 1.20) and the mean Singh Index score was 0.00 (SD = 0.89). The heritability of sleep duration was 39% and the Singh Index was 12%. The uncontrolled phenotypic regression of sleep duration on the Singh Index showed a significant negative relationship between area-level deprivation and sleep length (b = -0.080, P < 0.001). Every 1 SD in Singh Index was associated with a ∼4.5 min change in sleep duration. For the quasi-causal bivariate model, there was a significant main effect of E (b(0E) = -0.063; standard error [SE] = 0.30; P < 0.05). Residual variance components unique to sleep duration were significant for both A (b(0Au) = 0.734; SE = 0.020; P < 0.001) and E (b(0Eu) = 0.934; SE = 0.013; P < 0.001).

CONCLUSIONS

Area-level deprivation has a quasi-causal association with sleep duration, with greater deprivation being related to shorter sleep. As area-level deprivation increases, unique genetic and nonshared environmental residual variance in sleep duration increases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sleep Duration, Kidney Function, and Their Effects on Cerebral Small Vessel Disease in Elderly Hypertensive Patients

BACKGROUND

Short sleep duration has been shown to be associated with cardio/cerebrovascular disease. White matter hyperintensities (WMH) have been associated with an increased risk of stroke. In addition to high ambulatory blood pressure (BP), chronic kidney disease (CKD) is a risk for WMH. In this study, we investigated the relationships among sleep duration, CKD, and WMH in elderly hypertensives.

METHODS

Ambulatory BP monitoring and brain magnetic resonance imaging were performed in 514 Japanese elderly hypertensives (mean age 72.3 years, males 37%). WMH cases were further divided into deep subcortical white matter lesion or periventricular hyperintensity (PVH). CKD (n = 193) was defined as estimated glomerular filtration rate less than 60 ml/min/1.73 m(2).

RESULTS

According to sleep duration (<7.5, ≥7.5 to <9.5, and ≥9.5 hour per night), significant associations of sleep duration were observed with WMH and PVH. In the regression analysis including age, gender, smoking, antiplatelet agents use, 24-hour systolic BP, nondipper, white coat hypertension and CKD, short sleep duration was significantly positively associated with WMH and PVH when subjects with mid-range sleep duration were used as a reference group. A significant interaction was found between short sleep duration and CKD for PVH. In the non-CKD group, short sleep duration had strong significant positive associations with WMH and PVH.

CONCLUSIONS

In the present study, short sleep duration was a positive significant determinant for WMH and PVH in elderly hypertensives. Sleep duration might serve as a strong determinant for white matter lesions especially in those without CKD.

Common sleep disorders increase risk of motor vehicle crashes and adverse health outcomes in firefighters

STUDY OBJECTIVES

Heart attacks and motor vehicle crashes are the leading causes of death in US firefighters. Given that sleep disorders are an independent risk factor for both of these, we examined the prevalence of common sleep disorders in a national sample of firefighters and their association with adverse health and safety outcomes.

METHODS

Firefighters (n = 6,933) from 66 US fire departments were assessed for common sleep disorders using validated screening tools, as available. Firefighters were also surveyed about health and safety, and documentation was collected for reported motor vehicle crashes.

RESULTS

A total of 37.2% of firefighters screened positive for any sleep disorder including obstructive sleep apnea (OSA), 28.4%; insomnia, 6.0%; shift work disorder, 9.1%; and restless legs syndrome, 3.4%. Compared with those who did not screen positive, firefighters who screened positive for a sleep disorder were more likely to report a motor vehicle crash (adjusted odds ratio 2.00, 95% CI 1.29-3.12, p = 0.0021) and were more likely to self-report falling asleep while driving (2.41, 2.06-2.82, p < 0.0001). Firefighters who screened positive for a sleep disorder were more likely to report having cardiovascular disease (2.37, 1.54-3.66, p < 0.0001), diabetes (1.91, 1.31-2.81, p = 0.0009), depression (3.10, 2.49-3.85, p < 0.0001), and anxiety (3.81, 2.87-5.05, p < 0.0001), and to report poorer health status (p < 0.0001) than those who did not screen positive. Adverse health and safety associations persisted when OSA and non-OSA sleep disorders were examined separately.

CONCLUSIONS

Sleep disorders are prevalent in firefighters and are associated with increased risk of adverse health and safety outcomes. Future research is needed to assess the efficacy of occupational sleep disorders prevention, screening, and treatment programs in fire departments to reduce these safety and health risks.

Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives

Background

During nocturnal sleep, blood pressure (BP) “dips” compared to diurnal BP, reducing stress on the cardiovascular system. Both the hypotensive response elicited by acute aerobic exercise and sleep quality can impact this dipping response.

Purpose

The purpose of this study was to investigate the effects of aerobic exercise timing on circadian BP changes and sleep architecture.

Materials and methods

Twenty prehypertensive subjects completed the study. During four test sessions, participants first completed a graded exercise test to exhaustion and then performed 30 minutes of treadmill exercise at 7 am (7A), 1 pm (1P), and 7 pm (7P) in a random, counterbalanced order at 65% of the heart rate obtained at peak oxygen uptake. An ambulatory cuff was used to monitor BP responses during 24 hours following exercise, and an ambulatory sleep-monitoring headband was worn during sleep following each session.

Results

Aerobic exercise at 7A invoked a greater dip in nocturnal systolic BP than exercise at 1P or 7P, although the greatest dip in nocturnal diastolic BP occurred following 7P. Compared to 1P, 7A also invoked greater time spent in deep sleep.

Conclusion

These data indicate that early morning may be the most beneficial time to engage in aerobic exercise to enhance nocturnal BP changes and quality of sleep.

The relationship between dipping-non-dipping arterial blood pressure pattern and frequency of restless leg syndrome with related factors

Objective:

The lack of nocturnal decline in blood pressure (BP) is associated with an increase in cardiovascular events. Restless leg syndrome (RLS) is an uncomfortable feeling in which the patient wants to budge the legs with ache in the legs. RLS also increases the hypertension and cardiovascular risk. In this study, we aimed to evaluate the relationship between dipping and non-dipping blood pressure patterns with RLS and its severity.

Methods:

Two hundred patients who had 24-hour ambulatory blood pressure monitoring (ABPM) were enrolled into this cross-sectional study. They were classified by blood pressure pattern as dipping and non-dipping. Then, 100 patients with the dipper pattern and 100 patients with the non-dipper pattern were chosen. A questionnaire for RLS diagnosis that was prepared by the International RLS Study Group was given performed to the patients.

Results:

RLS symptom score was higher in patients with non-dipping blood pressure patterns (NDBPP), and patients with NDBPP had more severe RLS. Beside this, there were no differences in terms of RLS frequency in dipping and non-dipping blood pressure patterns.

Conclusion:

As a conclusion, dipping and non-dipping blood pressure patterns do not increase RLS risk. But, if patients with NDBPP have RLS, they have more severe RLS. So, we suggest that evaluating a patient with a non-dipping blood pressure pattern, considering RLS, would be helpful to ameliorate the quality of life of the patient

Relationship between self-reported sleep quality and metabolic syndrome in general population

BACKGROUND

To examine an association between self-reported sleep quality determined by Pittsburgh sleep quality index (PSQI) and metabolic syndrome.

METHODS

This study was designed as cross-sectional study. Participants were 1481 adults aged 20 years and above from general population (549 males and 932 females). We assessed the global sleep quality by PSQI. PSQI consists of 7 elements, i.e. subjective sleep quality, sleep latency (prolonged sleep onset time), sleep duration, habitual sleep efficiency (proportion of hours slept to hours spent in bed), sleep disturbance (interruption of sleep), use of sleep medication and daytime dysfunction (trouble staying awake while engaging in social activity). Any participants with score of 6 or more are diagnosed to have sleep disorder. We also assessed the above 7 elements, which consisted of a four-grade system (i.e. 0, 1, 2, 3). Metabolic syndrome consisted of abdominal obesity, hypertension, impaired glucose tolerance and dyslipidemia. Diagnosis of metabolic syndrome was done when the participants have abdominal obesity and meet two or more other components. All analyses were adjusted by age, drinking habit, smoking habit, working hours, exercise habit and depression.

RESULTS

Fifty-two male participants (9.5%) and 133 female (14.3%) scored 6 or more points in global PSQI score. The global PSQI score, sleep latency score and sleep disturbance score of participants with metabolic syndrome were higher level than those without the condition (p < 0.001, p = 0.009, p = 0.025 for male and p < 0.001, p < 0.001, p = 0.002 for females, respectively). The odds ratio of metabolic syndrome among participants with PSQI score of 6 or more points were 2.37 (95% confidence interval: 1.23-4.58) for males and 2.71 (1.45-5.07) for females in contrast to those with 5 or less points. The odds ratio of metabolic syndrome with sleep latency score of 2 was 2.65 (1.14-6.15) for male and 3.82 (1.81-8.09) for females in contrast with those of 0. The odds ratio of metabolic syndrome with sleep disturbance score of 1 was 1.76 (1.09-2.86) for males and 2.43 (1.26-4.69) for females in contrast with those of 0.

CONCLUSIONS

Global PSQI score and its components (especially, sleep latency and sleep disturbance) were associated with metabolic syndrome.

Association of short sleep duration with impaired glucose tolerance or diabetes mellitus

Aims/Introduction:  To examine the cross‐sectional relationship between sleep duration and impaired glucose tolerance (IGT), including diabetes mellitus (DM), we analyzed a large‐scale healthy workers database in Japan.

Materials and Methods:  We examined the baseline database of 4143 participants (3415 men and 728 women) aged 19–69 years. Sleep duration of participants was categorized into four groups: <6, 6 to <7, 7 to <8 and ≥8 h. The physical activity of each participant was classified according to the International Physical Activity Questionnaire (IPAQ). We defined IGT including DM (IGT/DM) in the present study according to previous studies as follows: fasting blood sugar level ≥110 mg/dL, or if <8 h after meals ≥140 mg/dL, or on medication for diabetes mellitus, or those diagnosed as having DM. Logistic regression was applied to estimate the odds ratio (OR) to examine the relationship between IGT/DM, sleep duration and other related factors.

Results:  The number of participants with IGT/DM was 402 (9.7%). The factors that significantly associated with IGT/DM were age (OR 1.08, 95% confidence interval [CI] 1.07–1.10, P < 0.001), high blood pressure (OR 1.94, CI 1.52–2.47, P < 0.001), and <6 h of sleep duration in comparison with 6 to <7 h sleep (OR 2.32, CI 1.18–4.55, P = 0.015). The associations of difficulty in sleep initiation, IPAQ classification, current smoking and alcohol intake with IGT/DM were not statistically significant.

Conclusions:  Our results showed that shorter sleep duration (<6 h of sleep duration per night) was associated with a risk of IGT/DM independent of other lifestyle habits and metabolic risk factors. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00114.x, 2011)

The effects of periodic limb movements in sleep (PLMS) on cardiovascular disease

Periodic limb movements in sleep (PLMS) are uncontrollable nocturnal movements that occur during sleep and increase with age. Research has implicated PLMS as a contributing factor to the development of cardiovascular disease (CVD). The purpose of this manuscript is to 1) explain the sleep disorder of PLMS and implications on CVD; 2) identify the impact of PLMS on CVD; 3) discuss treatment options for PLMS; 4) present future research needs for PLMS/RLS; 5) provide implications to health care providers to improve the care and health outcomes of persons with PLMS.

Sleep duration and depressive symptoms: a gene-environment interaction

OBJECTIVE

We used quantitative genetic models to assess whether sleep duration modifies genetic and environmental influences on depressive symptoms.

METHOD

Participants were 1,788 adult twins from 894 same-sex twin pairs (192 male and 412 female monozygotic [MZ] pairs, and 81 male and 209 female dizygotic [DZ] pairs] from the University of Washington Twin Registry. Participants self-reported habitual sleep duration and depressive symptoms. Data were analyzed using quantitative genetic interaction models, which allowed the magnitude of additive genetic, shared environmental, and non-shared environmental influences on depressive symptoms to vary with sleep duration.

RESULTS

Within MZ twin pairs, the twin who reported longer sleep duration reported fewer depressive symptoms (ec = -0.17, SE = 0.06, P < 0.05). There was a significant gene × sleep duration interaction effect on depressive symptoms (a'c = 0.23, SE = 0.08, P < 0.05), with the interaction occurring on genetic influences that are common to both sleep duration and depressive symptoms. Among individuals with sleep duration within the normal range (7-8.9 h/night), the total heritability (h2) of depressive symptoms was approximately 27%. However, among individuals with sleep duration within the low (< 7 h/night) or high (≥ 9 h/night) range, increased genetic influence on depressive symptoms was observed, particularly at sleep duration extremes (5 h/night: h2 = 53%; 10 h/night: h2 = 49%).

CONCLUSION

Genetic contributions to depressive symptoms increase at both short and long sleep durations.

Longitudinal associations between objective sleep and lipids: the CARDIA study

STUDY OBJECTIVE

To investigate the longitudinal relationships between actigraph-derived sleep duration, fragmentation, and lipid levels.

DESIGN AND SETTING

Longitudinal data from the Coronary Artery Risk Development in Young Adults Sleep Study (2003-05), an observational cohort at the Chicago site.

PARTICIPANTS

There were 503 black and white adults, ages 32-51 years, with no prior history of cardiovascular disease.

INTERVENTIONS

N/A.

MEASUREMENT AND RESULTS

Sleep duration and fragmentation were measured using 6 days of wrist actigraphy. Sleep quality was measured with the Pittsburgh Sleep Quality Index. The outcome variables, measured at 3 examinations over 10 years (Baseline [2000-01], 5-year [2005-06], and 10-year follow-up [2010-11]), were total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG), and TC/HDL ratio. The associations between each sleep parameter and 10-year change in lipids were analyzed with generalized estimating equation models adjusting for relevant confounders. After adjustment, each hour increase in sleep duration was significantly associated with higher TC (5.2 mg/dL, 95%CI: 1.7, 8.6) and LDL (3.4 mg/dL, 95%CI: 0.2, 6.6) in the total sample, a 1.1 mg/dL increase in TG (95%CI: 1.0, 1.1) among men, and a borderline significant greater odds for a TC/HDL ratio ≥ 5 among men (OR: 1.37, 95%CI: 0.99, 1.90). Overall, sleep fragmentation and sleep quality scores were not associated with change in lipids.

CONCLUSIONS

Beyond relevant covariates, over a 10-year follow-up, longer objective sleep duration was longitudinally and significantly associated with a poorer lipid profile. Greater objective sleep fragmentation and self-reported poor sleep quality were not related to a poorer lipid profile.

Associations between sleep duration and prevalence of cardiovascular events

BACKGROUND

Data regarding the associations between sleep duration and clinical cardiovascular (CV) events are limited. We aimed to analyze any associations between self-reported sleep duration and CV events.

HYPOTHESIS METHODS

This is a cross-sectional analysis of nationally representative population of noninstitutionalized US civilians recruited in the 2007 to 2008 National Health and Nutrition Examination Survey. This is a questionnaire-based study including only those subjects who answered questions on sleep duration and CV events. The main outcome measures were prevalence of congestive heart failure, myocardial infarction, stroke, coronary artery disease, and angina.

RESULTS

After logistic regression analysis, significant associations between sleep duration and prevalence of stroke, myocardial infarction, congestive heart failure, coronary artery disease, and angina were found. There was a statistically significant increase in stroke in those with <6 hours of sleep (odds ratio [OR]: 2.0111, 95% confidence interval [CI]: 1.4356-2.8174), in myocardial infarction in those with <6 hours of sleep (OR: 2.0489, 95% CI: 1.4878-2.8216), in congestive heart failure in those with <6 hours of sleep (OR: 1.6702, 95% CI: 1.1555 to 2.4142), in coronary artery disease in those with >8 hours of sleep (OR: 1.1914, 95% CI: 1.0712-3.4231), and in angina in those with >8 hours of sleep (OR: 2.0717, 95% CI: 1.0497-4.0887).

CONCLUSIONS

The results of this cross-sectional analysis suggest that sleep duration may be associated with the prevalence of various CV events.

A prospective cohort study on the relationship of sleep duration with all-cause and disease-specific mortality in the Korean Multi-center Cancer Cohort study

Objectives

Emerging evidence indicates that sleep duration is associated with health outcomes. However, the relationship of sleep duration with long-term health is unclear. This study was designed to determine the relationship of sleep duration with mortality as a parameter for long-term health in a large prospective cohort study in Korea.

Methods

The study population included 13 164 participants aged over 20 years from the Korean Multi-center Cancer Cohort study. Information on sleep duration was obtained through a structured questionnaire interview. The hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were estimated using a Cox regression model. The non-linear relationship between sleep duration and mortality was examined non-parametrically using restricted cubic splines.

Results

The HRs for all-cause mortality showed a U-shape, with the lowest point at sleep duration of 7 to 8 hours. There was an increased risk of death among persons with sleep duration of ≤5 hours (HR, 1.21; 95% CI, 1.03 to 1.41) and of ≥10 hours (HR, 1.36; 95% CI, 1.07 to 1.72). In stratified analysis, this relationship of HR was seen in women and in participants aged ≥60 years. Risk of cardiovascular disease-specific mortality was associated with a sleep duration of ≤5 hours (HR, 1.40; 95% CI, 1.02 to 1.93). Risk of death from respiratory disease was associated with sleep duration at both extremes (≤5 and ≥10 hours).

Conclusions

Sleep durations of 7 to 8 hours may be recommended to the public for a general healthy lifestyle in Korea.

Sleep problems and cardiovascular function in children

OBJECTIVE

To assess the associations of sleep problems with 24-hour ambulatory blood pressure and cardiovascular reactivity in children.

METHODS

Sleep problems in 285 term-born, healthy 8-year-olds (mean [standard deviation] = 8.1 [0.3] years) were measured with a parent-rated Sleep Disturbance Scale for Children. Ambulatory blood pressure (n = 241) was measured for 24 hours (41% nonschool days) with an oscillometric device. The children (n = 274) underwent the Trier Social Stress Test for Children during which blood pressure, electrocardiography, and thoracic impedance were recorded and processed offline to give measures of cardiovascular and autonomic function.

RESULTS

No associations were found between sleep problems and 24-hour ambulatory blood pressure. Children with sleep breathing disorders (n = 5) had higher baseline sympathetic vascular activity (p = .014) and higher heart rate (p = .044) and sympathetic cardiac activity (p = .031) in reaction to stress. Children with disorders of excessive somnolence (n = 55) had higher baseline parasympathetic activity (p = .016). None of the associations remained significant after controlling for multiple testing.

CONCLUSIONS

Our results suggest that in a healthy community sample of prepubertal children, sleep problems are not associated with an unhealthy cardiovascular phenotype at this age. However, associations may be underestimated because of the low prevalence of sleep breathing disorders in this sample and may not generalize to older populations.

Sleep duration and insomnia in the elderly: associations with blood pressure variability and carotid artery remodeling

BACKGROUND

Recent studies have shown that short and long sleep durations and insomnia are associated with increased home-measured blood pressure (BP) variability, which in turn has a relationship with arterial stiffness. However, the determinants for visit-to-visit systolic blood pressure (SBP) variability have rarely been investigated in relation to sleep duration, insomnia, and carotid arterial stiffness.

METHOD

The subjects were 201 elderly individuals (79.9±6.4 years old) with one or more cardiovascular risks. Based on 12 visits, visit-to-visit BP variability (expressed as a coefficient of variation [CV]) and δ (maximum - minimum) BP were measured. Self-reported sleep duration and insomnia questionnaires were used to classify the patients according to sleep duration period and insomnia status.

RESULTS

After multivariable adjustment, long sleep duration (≥ 9 hours per night) had significant positive associations with SBP δ (P < 0.05), while persistent insomnia had significant positive associations with SBP CV (P < 0.05) and δ (P < 0.01). Additionally, significant interactions were found in terms of long sleep duration by carotid artery stiffness parameter β (P < 0.05), persistent insomnia by intima-media thickness (P < 0.01), and persistent insomnia by stiffness parameter β (P < 0.05) for SBP δ.

CONCLUSION

In elderly patients at high risk for cardiovascular disease, long sleep duration as well as persistent insomnia were significantly associated with higher visit-to-visit BP variability. Long sleep duration and persistent insomnia each had synergetic interactions with carotid artery stiffness and with visit-to-visit BP variability.

Daylight saving time transitions and acute myocardial infarction

Most recently, the possible impact of transitions to and from daylight saving time (DST) on the increased incidence of acute myocardial infarction (AMI) has been suggested. The goal of this report was to analyze independent influence of DST transitions on the incidence of AMI with simultaneous control for the confounding presence of situational triggers such as physical exertion, emotional stress, heavy meals, and sexual intercourse, as well as for other clinical factors. Detailed information was obtained from 2412 patients and included baseline characteristics, working status, exact time of AMI, possible external triggers, cardiovascular risk factors, and prehospital medication. AMI incidence on days after the DST was compared with incidence during control periods and patient characteristics, cardiovascular medication, and circumstances of AMI were evaluated to identify potential risk modifiers. Relative risks of AMI and differences in patient characteristics were expressed through incidence ratios and odds ratios, respectively, with 95% confidence intervals (CIs). Multivariate analysis was performed by using a stepwise multiple regression to assess the independent predictive significance of the characteristics of patients for the AMI occurring in the posttransitional period. The incidence ratio for AMI for the first four workdays after the spring DST transition was 1.29 (95% CI: 1.09-1.49) and the excess was particularly prominent on Monday. In autumn, the incidence ratio for AMI for this 4-d period was 1.44 (95% CI: 1.19-1.69), with peaks on Tuesday and Thursday. The independent predictors for AMI during this period in spring were male sex (p = 0.03) and nonengagement in physical activity (p = 0.02) and there was a trend for the lower risk of incident among those taking calcium antagonists (p = 0.07). In autumn, the predictors were female sex (p = 0.04), current employment (p = 0.006), not taking β-blocker (p = 0.03), and nonengagement in physical activity (p = 0.02). The present report supports the possibility that DST transitions represent additional chronobiological feature of AMI, and that risk of an onset varies according to sex, employment status, and the taking of cardiovascular medication.

Quick to berate, slow to sleep: interpartner psychological conflict, mental health, and sleep

OBJECTIVE

Relations between interpartner psychological conflict (IPC) and the sleep of men and women were examined, and depression and anxiety symptoms were assessed as intervening variables of these associations.

METHOD

Participants were 135 cohabiting or married couples. The mean age was 36.50 (SD = 5.93) for women and 39.37 (SD = 7.33) for men. Most women (76%) and men (78%) were European American (EA) and the rest were predominantly African American (AA); there was a wide socioeconomic representation. Men and women reported on IPC used by their partner against them. Sleep was examined objectively with actigraphs, and multiple sleep quantity and quality measures were derived.

RESULTS

Dyadic path analysis in which both actor and partner effects were assessed was conducted. For women, greater IPC by the partner was related to elevated levels of anxiety, which in turn was associated with shorter sleep duration and worse sleep efficiency; anxiety was an intervening variable. For men, IPC by the partner was related to greater symptoms of anxiety and depression; the latter was an intervening variable linking IPC with sleep quality (lower efficiency, longer latency). Some partner effects were observed and indicate that for both men and women, one's perpetration of IPC is related to increased anxiety in the partner, which in turn is related to longer sleep latency for the actor.

CONCLUSION

Results build on this scant literature, and using objective well-validated measures of sleep highlight the importance of relationship processes and mental health for the sleep of men and women.

The relationship between self-reported nocturnal sleep duration, daytime sleepiness and 24-h urinary albumin and protein excretion in patients with newly diagnosed type 2 diabetes

AIM

In the current study the relationship between self-reported nocturnal sleep duration (NSD) and daytime sleepiness with 24-h urinary protein excretion (UPE) and 24-h urinary albumin excretion (UAE) were investigated in patients with newly diagnosed type 2 diabetes mellitus.

METHODS

All patients underwent history taking, physical examination, blood pressure (BP) measurement, 12 lead electrocardiographic evaluation, routine urine analysis, biochemical analysis, 24-h urine collection to measure UAE, UPE and creatinine clearance. Self reported NSD and daytime sleepiness (using Epworth Sleepiness Scale (ESS)) were recorded for all patients.

RESULTS

In total 110 patients (56 male and 54 female) were included. Self reported NSD was 7.17 ± 1.07 h. Mean ESS score was 5.59 ± 2.48. Stepwise linear regression of independent factors revealed that logarithmically converted 24-h UAE (as a dependent parameter) was related with clinical systolic BP (b: 0.01, p: 0.003), HbA1c (b: 0.082, p: 0.033), self reported NSD (b: -0.152, p: 0.004) and ESS score (b: 0.044, p: 0.043). Additionally, on the other hand, 24-h UPE was related with clinical systolic BP (b: 0.011, p: 0.001) and self reported NSD (b: -0.179, p<0.0001) in regression analysis.

CONCLUSION

In conclusion, 24-h UAE were independently related with self reported NSD and daytime sleepiness where as 24-h UPE was related with only NSD in patients with newly diagnosed type 2 diabetic patients.

Short sleep duration and type 2 diabetes enhance the risk of cardiovascular events in hypertensive patients

AIMS

We tested the hypothesis that short sleep duration is not only a risk factor for diabetes, but that the two conditions in combination would be associated with the risk of incident cardiovascular disease (CVD).

METHODS

We analyzed 1255 hypertensive patients (mean age: 70.4±9.9 years) with (N=299) and without diabetes (N=956). Short sleep duration was defined as a sleep time <7.5 h. A Hard CVD event was defined as either myocardial infarction, stroke, or sudden cardiac death; and All CVD events as Hard CVD events plus angina, heart failure and end-stage renal disease.

RESULTS

When the patients were divided into 4 categories by diabetes (present or absent) and sleep duration (short or long), the diabetes+short sleep group had a significantly higher incidence of both Hard CVD events (HR=2.27, 95% CI=1.17-4.42, P=0.015) and All CVD events (HR=2.47, 95% CI=1.37-4.43, P=0.003) compared with the non-diabetes+long sleep group, independent of significant covariates. There were significant interactions between sleep duration and glycemic control on CVD events.

CONCLUSIONS

The combination of both diabetes and short duration of sleep was associated with higher risk of incident CVD compared with those with only one or neither condition. Altered glycemic control and short sleep duration could act synergistically to pose a risk for future CVD.