Short sleep duration is associated with enhanced endothelin-1 vasoconstrictor tone

Depressive symptoms and sleep duration in relation to chronic kidney disease: Evidence from the China health and retirement longitudinal study

OBJECTIVE

Nowadays, the joint effects of depressive symptoms and sleep duration on the risk of chronic kidney disease (CKD) are still unclear. We aimed to prospectively assess the combined effect of depressive symptoms and sleep duration on the incidence of CKD in middle-aged and elderly Chinese population.

METHODS

A total of 10,953 participants from the China Health and Retirement Longitudinal Study (CHARLS) were included. Depressive symptoms were measured using the 10-item Center for Epidemiological Studies Depression scale (CESD-10). Sleep duration was evaluated by self-reported. CKD events were based on self-reported physicians' diagnosis or personal estimate glomerular filtration rate level (eGFR <60 mL/min/1.73 m2). Cox regression models were established to analyze the correlation between depressive symptoms, sleep duration and the risk of CKD.

RESULTS

Over a mean follow-up time was 6.76 ± 0.98 years, 851 (7.8%) participants had reported CKD events during the follow-up. Elevated depressive symptoms (HR = 1.65, 95% CI = 1.43-1.90) and short sleep duration (HR = 1.48, 95% CI = 1.27-1.72) were independently associated with an increased CKD risk after adjusting for potential confounding factors. Participants with short sleep duration (< 6 h)/elevated depressive symptoms (HR = 2.24, 95% CI = 1.89-2.65) were associated with the highest risk of CKD than those with normal sleep duration/low depressive symptoms.

CONCLUSIONS

Elevated depressive symptoms and short sleep duration were independent risk factors for CKD. There was a combined effect between depressive symptoms and sleep duration in increasing the risk of CKD.

Healthy Sleep Every Day Keeps the Doctor Away

When one considers the big picture of their health, sufficient sleep may often go overlooked as a keystone element in this picture. Insufficient sleep in either quality or duration is a growing problem for our modern society. It is essential to look at what this means for our health because insufficient sleep increases our risks of innumerable lifechanging diseases. Beyond increasing the risk of developing these diseases, it also makes the symptoms and pathogenesis of many diseases worse. Additionally, consistent quality sleep can not only improve our physical health but has also been shown to improve mental health and overall quality of life. Substandard sleep health could be a root cause for numerous issues individuals may be facing in their lives. It is essential that physicians take the time to learn about how to educate their patients on sleep health and try to work with them on an individual level to help motivate lifestyle changes. Facilitating access to sleep education for their patients is one way in which physicians can help provide patients with the tools to improve their sleep health. Throughout this paper, we will review the mechanisms behind the relationship between insufficient sleep health and chronic disease and what the science says about how inadequate sleep health negatively impacts the overall health and the quality of our lives. We will also explain the lifechanging effects of sufficient sleep and how we can help patients get there.

Self-Reported Sleep Characteristics Associated with Cardiovascular Disease Among Older Adults Living in Rural Eastern China: A Population-Based Study

Purpose

To investigate the cross-sectional associations of self-reported sleep characteristics with cardiovascular diseases (CVDs) and cardiovascular multimorbidity in older adults living in rural Eastern China.

Patients and Methods

This population-based study included 4618 participants (age ≥65 years; 56.5% women) living in rural Eastern China. In March–September 2018, data were collected through interviews, clinical examinations, neuropsychological testing, and laboratory tests. Sleep parameters were assessed using the Pittsburgh Sleep Quality Index, Epworth Sleepiness Score, and Berlin questionnaire. Coronary heart disease (CHD), heart failure (HF), and stroke were defined according to in-person interviews, clinical and neurological examinations, and electrocardiogram examination. Data were analyzed using logistic regression and restricted cubic spline regression.

Results

CHD was diagnosed in 991 participants, HF in 135 participants, and stroke in 696 participants. The multivariable-adjusted odds ratio (OR) of CHD was 1.27 (95% CI, 1.09–1.49) for sleep duration ≤6 hours/night (vs >6–8 hours/night), 1.40 (1.20–1.62) for poor sleep quality, and 1.22 (1.04–1.43) for high risk for obstructive sleep apnea (OSA). The OR of HF was 2.16 (1.38–3.39) for sleep duration >8 hours/night, and 1.76 (1.22–2.54) for high risk for OSA. In addition, the OR of stroke was 1.23 (1.04–1.46) for poor sleep quality, 1.32 (1.01–1.72) for excessive daytime sleepiness, and 1.42 (1.19–1.70) for high risk for OSA. The associations of poor sleep with cardiovascular multimorbidity (≥2 CVDs) were stronger than that of sleep problems with a single CVD.

Conclusion

Extreme sleep duration, high risk for OSA, and other sleep problems were associated with CVDs, especially cardiovascular multimorbidity.

Short Sleep Duration and Erectile Dysfunction: A Review of the Literature

The meaning of sleep has puzzled people for millennia. In modern society, short sleep duration is becoming a global problem. It has been established that short sleep duration can increase the risk of several diseases, such as cardiovascular and metabolic diseases. Currently, a growing body of research has revealed a possible link between sleep disorders and erectile dysfunction (ED). However, the mechanisms linking short sleep duration and ED are largely unknown. Thus, we provide a review of clinical trials and animal studies. In this review, we propose putative pathways connecting short sleep duration and ED, including neuroendocrine pathways and molecular mechanisms, aiming to pave the way for future research. Meanwhile, the assessment and improvement of sleep quality should be recommended in the diagnosis and treatment of ED patients.

The association of nighttime sleep duration and quality with chronic kidney disease in middle-aged and older Chinese: a cohort study

OBJECTIVE

This cohort study aimed to assess the associations between sleep duration and quality with the risk of incident chronic kidney disease (CKD) in middle-aged and older Chinese.

METHODS

We used the 2011 and 2015 surveys of the China Health and Retirement Longitudinal Study (CHARLS). Nighttime sleep duration was categorized into five groups: ≤4, (4-6], (6-8], (8-10], and >10 h/night. Sleep quality was assessed by restless days in the past week (<1, 1-2, 3-4, and 5-7 days/week). Multivariate logistic regression was used to assess the association between sleep duration and quality with incident CKD.

RESULTS

A total of 11,339 participants free of CKD at baseline were included in this study. After four years follow-up, the incidence of CKD was 7.8%. There was a "U-shaped" association between sleep duration and risk of CKD. Compared to 6-8 h of nighttime sleep duration, those who slept ≤4 h/night (RR: 1.639, 95% CI: 1.287-2.087) or >10 h/night (RR: 2.342, 95% CI: 1.007-5.451) had increased risk of developing CKD after adjustment for confounders. Participants with 5-7 restless days per week had significantly increased risk of CKD (adjusted RR: 1.686, 95% CI: 1.352-2.102), compared to those who rarely or never had a restless sleep.

CONCLUSIONS

Extreme nighttime sleep duration and poor sleep quality were associated with increased risk of CKD in middle-aged and older Chinese. Obtaining an optimal nighttime sleep duration and better sleep quality might reduce the risk of CKD.

Individual variation of follicular phase changes in endothelial function across two menstrual cycles

NEW FINDINGS

What is the central question of this study? The purpose of this study was to determine intra-individual reproducibility of follicular phase changes in endothelial function (flow-mediated dilatation) over two menstrual cycles in healthy, premenopausal women. What is the main finding and its importance? Phase changes in endothelial function were not consistent at the individual level across two menstrual cycles, which challenges the utility of interpreting individual responses over one cycle.

ABSTRACT

Evidence regarding the impact of menstrual phase on endothelial function is conflicting, and studies to date have examined responses only over a single cycle. It is unknown whether the observed inter-individual variability of phase changes in endothelial function reflects stable, inter-individual differences in responses to oestrogen (E₂ ; a primary female sex hormone). The purpose of this study was to examine changes in endothelial function from the early follicular (EF; low-E₂ ) phase to the late follicular (LF; high-E₂ ) phase over two consecutive cycles. Fourteen healthy, regularly menstruating women [22 ± 3 years of age (mean ± SD)] participated in four visits (EF_Visit 1 , LF_Visit 2 , EF_Visit 3 and LF_Visit 4 ) over two cycles. Ovulation testing was used to determine the time between the LF visit and ovulation. During each visit, endothelial function [brachial artery flow-mediated dilatation (FMD)], E₂ and progesterone were assessed. At the group level, there was no impact of phase or cycle on FMD (P = 0.48 and P = 0.65, respectively). The phase change in FMD in cycle 1 did not predict the phase change in cycle 2 (r = 0.03, P = 0.92). Using threshold-based classification (2 × typical error threshold), four of 14 participants (29%) exhibited directionally consistent phase changes in FMD across cycles. Oestrogen was not correlated between cycles, and this might have contributed to variability in the FMD response. The intra-individual variability in follicular fluctuation in FMD between menstrual cycles challenges the utility of interpreting individual responses to phase over a single menstrual cycle.

Effects of sleep deprivation on endothelial function in adult humans: a systematic review

Sleep deprivation is highly prevalent and is associated with increased cardiovascular disease (CVD) morbidity and mortality. Age-related alterations in sleep and chronobiology may exaggerate CVD susceptibility in older individuals. The mechanisms responsible for the association between sleep deprivation and CVD are not fully understood, but endothelial dysfunction may play a central role. Our objective was to conduct a systematic literature review to evaluate the evidence on the effects of sleep deprivation on endothelial function (EF). This review adhered to the PRISMA guidelines and was pre-registered with PROSPERO (#CRD42020192485, 07/24/2020). We searched PubMed, Web of Science, Embase, and Cochrane Library for articles published through May 1, 2020. Eligibility criteria included publication in English and use of well-established EF methodologies in adult humans. Two investigators independently performed the literature search, study selection, data extraction, risk-of-bias assessment, and qualitative data synthesis. Out of 3571 articles identified, 24 articles were included in the systematic review. Main findings include the following: (1) shorter sleep duration is associated with lower macrovascular EF; (2) not sleeping 7-9 h/night is linked with impaired microvascular EF; (3) sleep restriction impairs micro- and macrovascular EF; (4) acute total sleep deprivation impairs micro- and macrovascular EF but data on macrovascular EF are less consistent; and (5) shift work impairs macrovascular EF. In conclusion, sleep deprivation impairs EF, which may explain the link between insufficient sleep and CVD. Future investigations should fully elucidate the underlying mechanisms and develop strategies to combat the adverse endothelial effects of sleep deprivation across the lifespan.

Regular aerobic exercise counteracts endothelial vasomotor dysfunction associated with insufficient sleep

Insufficient sleep is associated with endothelial vasomotor dysfunction and increased cardiovascular risk. Regular aerobic exercise is an effective lifestyle strategy for improving endothelial function and, in turn, reducing cardiovascular risk. We tested the hypotheses that regular aerobic exercise would 1) improve endothelial vasodilation and 2) decrease endothelin (ET)-1-mediated vasoconstrictor tone in middle-aged adults who chronically sleep <7 h/night. Thirty-six healthy, middle-aged adults were studied: 16 with normal sleep duration (age: 57 ± 2 yr; sleep duration: 7.4 ± 0.1 h/night) and 20 with short sleep duration (age: 56 ± 1 yr; sleep duration: 6.2 ± 0.1 h/night). The 20 short sleepers completed a 3-mo aerobic exercise training intervention. Forearm blood flow was determined (via plethysmography) in response to intra-arterial acetylcholine (ACh), BQ-123 (ET_A receptor antagonist), ACh + BQ-123, and sodium nitroprusside. Forearm blood flow responses to ACh were lower (∼20%; P < 0.05) in the short (from 4.2 ± 0.2 to 10.5 ± 0.6 mL/100 mL tissue/min) versus normal (4.2 ± 0.2 to 12.7 ± 0.6 mL/100 mL tissue/min) sleepers. In response to BQ-123, the short-sleep group had a significantly greater increase in resting forearm blood flow than the normal-sleep group (∼25% vs. ∼8%). ACh + BQ-123 resulted in a significant (∼25%) increase in the ACh-mediated vasodilation in the short-sleep group only. After exercise training, although nightly sleep duration was unchanged (6.4 ± 0.1 h/night), ACh-mediated vasodilation was significantly higher (∼20%), ET-1-mediated vasoconstriction was significantly lower (∼80%), and the vasodilator response to ACh was not increased with ET_A receptor blockade. Regular aerobic exercise, independent of changes in nightly sleep duration, can counteract insufficient sleep-related endothelial vasomotor dysfunction.NEW & NOTEWORTHY Habitual insufficient nightly sleep (<7 h/night) is associated with increased risk of cardiovascular disease and events. Endothelial dysfunction, specifically reduced endothelium-dependent vasodilation and increased endothelin (ET)-1-mediated vasoconstriction, is considered to be a major contributing mechanism underlying increased vascular risk with insufficient sleep. In contrast to insufficient sleep, regular aerobic exercise enhances endothelial vasomotor function, reducing the risk of cardiovascular disease and associated events. In the present study, we determined the effects of aerobic exercise training on endothelium-dependent vasodilation and ET-1 vasoconstriction in adults who habitually sleep <7 h/night. After exercise training, although nightly sleep duration was unchanged, endothelium-dependent vasodilation was significantly enhanced and ET-1-mediated vasoconstrictor tone was significantly reduced in adults who sleep <7 h/night. Regular aerobic exercise training can mitigate insufficient sleep-related endothelial vasomotor dysfunction and, in turn, potentially reduce the cardiovascular risk associated with habitual insufficient nightly sleep.

The impact of individual lifestyle and status on the acquisition of COVID-19: A case-Control study

Background

Coronavirus disease 2019 (COVID-19) has spread to the world. Whether there is an association between lifestyle behaviors and the acquisition of COVID-19 remains unclear.

Methods

In this case-control study, we recruited 105 patients with SARS-CoV-2 infection as a case group from the Wuhan Tongji Hospital (Wuhan, China). For each case two control subjects were recruited. Participants were randomly selected from communities in Wuhan and matched for sex, age (± 2yrs), and pre-existing comorbidities (hypertension and diabetes).

Results

A total of 105 patients diagnosed with COVID-19 and 210 controls were included. Compared with control group, the case group had higher proportions of lack of sleep (30.5% vs. 14.8%, P = 0.001) and increased physical activities (56.2% vs. 32.9%, P < 0.001). And patients in the case group were more likely to have alopecia (28.6% vs. 10.0%, P < 0.001) than people from the control group. Overall, we found that lack of sleep [adjusted odds ratio (OR) 1.56, 95% confidence interval (CI) 1.03–2.39)], physical activities (≥ 5 times a week) (adjusted OR 2.05, 95%CI 1.39–3.02) and alopecia (adjusted OR 1.73, 95%CI 1.13–2.66) were independent risk factors for COVID-19 infection. Conversely, low-dose alcohol intake (<100g alcohol per week), hand hygiene, and fruits intake (daily) were significantly associated with a decrease in morbidity.

Conclusions

Individual lifestyle behaviors and health status can affect the occurrence of COVID-19.

Low sleep efficiency does not impact upper or lower limb vascular function in young adults

NEW FINDINGS

What is the central question of this study? We sought to investigate whether young adults reporting low sleep quality possessed lower vascular function and altered autonomic nervous system modulation when compared with young adults reporting high sleep quality. What is the main finding and its importance? The study revealed that in young adults reporting low sleep quality, neither vascular nor autonomic function was significantly different when compared with young adults reporting high sleep quality. These findings suggest that young adults are either not substantially impacted by or can adequately adapt to the negative consequences commonly associated with poor sleep.

ABSTRACT

The aim of the study was to investigate whether young adults reporting low sleep quality also possessed lower vascular function, potentially stemming from altered autonomic nervous system modulation, when compared with young adults reporting high sleep quality. Thirty-one healthy young adults (age 24 ± 4 years) underwent a 7 night sleep assessment (Actigraph GT3X accelerometer). After the sleep assessment, subjects meeting specific criteria were separated into high (HSE; ≥85%; n = 11; eight men and three women) and low (LSE; <80%; n = 11; nine men and two women) sleep efficiency groups. Peripheral vascular function was assessed in the upper and lower limb, using the flow-mediated dilatation technique in the arm (brachial artery) and leg (superficial femoral artery). Heart rate variability was evaluated during 5 min of rest and used frequency parameters reflective of parasympathetic and/or sympathetic nervous system modulation (high- and low-frequency parameters). By experimental design, significant differences in sleep quality between groups were reported, with the LSE group exhibiting a longer time awake after sleep onset, higher number of awakenings and longer average time per awakening when compared with the HSE group. Despite these differences in sleep quality, no significant differences in upper and lower limb vascular function and heart rate variability measures were revealed when comparing the LSE and HSE groups. Additionally, in all subjects (n = 31), no correlations between sleep efficiency and vascular function/autonomic modulation were revealed. This study revealed that low sleep quality does not impact upper or lower limb vascular function or autonomic nervous system modulation in young adults.

Effects of Sleep Duration on Cardiovascular Events

PURPOSE OF REVIEW

Sleep is an essential component of human health, and suboptimal sleep duration has been associated with increased cardiovascular morbidity and mortality. This review summarizes physiological and pathological effects of sleep duration on the cardiovascular system.

RECENT FINDINGS

Both decreased and increased duration of sleep lead to increased cardiovascular mortality and has a U-shaped curve. Sleep apnea is an independent risk factor for atherosclerosis and hypertension, and its treatment with continuous positive airway pressure (CPAP) results in increased survival. Estimated sleep duration of 6-8 h is associated with decreased mortality and major cardiovascular events and should be addressed by clinicians during routine visits.

Circadian Rhythm of Vascular Function in Midlife Adults

Objective- Adverse cardiovascular events occur more frequently in the morning than at other times of the day. Vascular endothelial function (VEF)-a robust cardiovascular risk marker-is impaired during this morning period. We recently discovered that this morning impairment in VEF is not caused by either overnight sleep or the inactivity that accompanies sleep. We determined whether the endogenous circadian system is responsible for this morning impairment in VEF. We also assessed whether the circadian system affects mechanistic biomarkers, that is, oxidative stress (malondialdehyde adducts), endothelin-1, blood pressure, and heart rate. Approach and Results- Twenty-one (11 women) middle-aged healthy participants completed a 5-day laboratory protocol in dim light where all behaviors, including sleep and activity, and all physiological measurements were evenly distributed across the 24-hour period. After baseline testing, participants underwent 10 recurring 5-hour 20-minute behavioral cycles of 2-hour 40-minute sleep opportunities and 2 hours and 40 minutes of standardized waking episodes. VEF, blood pressure, and heart rate were measured, and venous blood was sampled immediately after awakening during each wake episode. Independent of behaviors, VEF was significantly attenuated during the subjective night and across the morning ( P=0.04). Malondialdehyde adducts and endothelin-1 exhibited circadian rhythms with increases across the morning vulnerable period and peaks around noon ( P≤0.01). Both systolic ( P=0.005) and diastolic blood pressure ( P=0.04) were rhythmic with peaks in the late afternoon. Conclusions- The endogenous circadian system impairs VEF and increases malondialdehyde adducts and endothelin-1 in the morning vulnerable hours and may increase the risk of morning adverse cardiovascular events in susceptible individuals. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT02202811.

Sleep Apnea and Heart

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

Insufficient sleep is associated with a pro-atherogenic circulating microRNA signature

NEW FINDINGS

What is the central question of the study Is habitual short sleep associated with altered circulating levels of specific inflammation- and vascular-related microRNAs? What is the main finding and its importance? Circulating levels of miR-125a, miR-126 and miR-146a were significantly lower in the short sleep compared with the normal sleep group. Altered circulating profiles of these vascular-related microRNAs have been linked to vascular inflammation, dysfunction and increased cardiovascular disease events. Sleep-related changes in these microRNAs are consistent with, and might play a role in, the aberrant vascular physiology and increased vascular risk associated with short sleep.

ABSTRACT

Habitual short sleep duration (<7 h night^-1 ) is associated with increased morbidity and mortality attributable, in large part, to increased inflammatory burden and endothelial dysfunction. MicroRNAs (miRNAs) play a key role in regulating vascular health, and circulating levels are now recognized to be sensitive and specific biomarkers of cardiovascular function, inflammation and disease.  The aim of this study was to determine whether the expression of circulating miR-34a, miR-92a, miR-125a, miR-126, miR-145, miR-146a and miR-150 is disrupted in adults who habitually sleep <7 h night^-1 (short sleep). These were chosen based upon their well-established links with vascular inflammation, function and, in turn, cardiovascular risk. Twenty-four adults were studied: 12 with normal nightly sleep duration (six men and six women; age, 55 ± 3 years old; sleep duration, ≥7.0 h night^-1 ) and 12 with short nightly sleep duration (seven men and five women; 55 ± 2 years old; sleep duration, <7 h night^-1 ), and circulating miRNA expression was assayed by RT-PCR. All subjects were non-smokers, normolipidaemic, non-medicated and free of overt cardiovascular disease. Circulating levels of miR-125a (3.07 ± 1.98 versus 7.34 ± 5.34 a.u.), miR-126 [1.28 (0.42-2.51) versus 1.78 (1.29-4.80) a.u.] and miR-146a [2.55 (1.00-4.80) versus 6.46 (1.50-11.44) a.u.] were significantly lower (∼60, 40 and 60%, respectively) in the short compared with the normal sleep group. However, there were no significant group differences in circulating levels of miR-34a, miR-92a, miR-145 and miR-150. In summary, chronic short sleep is associated with a marked reduction in circulating levels of miR-125a, miR-126 and miR-146a. Dysregulation of these miRNAs might contribute to the increased inflammatory burden and endothelial dysfunction associated with habitual insufficient sleep.

Effects of prolonged paradoxical sleep deprivation with or without acute cold stress on hemodynamic perturbations in rats

Prolonged paradoxical sleep deprivation (PSD) and cold stress (CS) are known to cause sympathoexcitation and increase the risk of cardiovascular disease. The present study examined the effect of PSD with CS on hemodynamic perturbations by investigating blood pressure and heart rate variability (BPV and HRV) in conscious rats. Adult male Sprague-Dawley rats were divided into three groups (n = 10, each): normal sleep (NS), PSD of 72 h, and recovery sleep of 7 days after PSD. When compared with NS, PSD increased systolic blood pressure in all three conditions: before CS (PreCS), CS, and after CS (PostCS). The PSD also increased heart rate in both PreCS and PostCS. Furthermore, spectral power changes were observed throughout the experiment. The PSD increased very-low-frequency BPV in PreCS, decreased very-low-frequency HRV in CS, and increased low-frequency BPV in all three conditions. The PSD increased low-frequency HRV in PreCS, increased high-frequency BPV in both CS and PostCS, and also increased high-frequency HRV in both PreCS and CS but decreased that in PostCS. On the other hand, when compared with PSD, recovery sleep has reversed most cardiovascular changes in PSD toward the NS level. However, when compared with NS, spectral powers of very-low-frequency BPV in the recovery phase showed a lower level. These results showed that in the resting condition, PSD might evoke sympathoexcitation with a tendency to increase both very-low-frequency BPV and very-low-frequency HRV, as the intensified myogenic oscillations. However, in the CS condition, PSD evoked the sympathoexcitation yet might attenuate such myogenic oscillations.

Actigraphy-based sleep characteristics and aortic stiffness: the Multi-Ethnic Study of Atherosclerosis

The study aimed to examine the association between objective estimates of sleep duration and quality and aortic stiffness while accounting for the potential confounding effect of sleep-disordered breathing. Participants were part of the Multi-Ethnic Study of Atherosclerosis Sleep study. Sleep duration and quality were assessed by 7-day wrist actigraphy, sleep-disordered breathing by home polysomnography, and aortic stiffness by magnetic resonance imaging-based aortic pulse wave velocity (aPWV), ascending and descending aorta distensibility. Aortic stiffness of participants with "normal" sleep duration (6-8 hours) were compared with those of "short" (<6 hours) and "long" sleep duration (>8 hours) adjusting for common cardiovascular risk factors and apnea-hypopnea index. The sample consisted of 908 participants (mean age 68.4 ± 9.1 years, 55.3% female). There was a significant linear trend of increased aPWV across short (n = 252), normal (n = 552), and long sleep durations (n = 104) (P for trend = .008). Multivariable analysis showed that people with short sleep duration had 0.94 m/s lower aPWV (95% CI: -1.54, -0.35), compared with those with normal sleep duration. In this ethnically diverse community cohort, habitual short sleep duration as estimated by actigraphy was associated with lower aortic stiffness.

U-shaped association between sleep duration and urinary albumin excretion in Korean adults: 2011-2014 Korea National Health and Nutrition Examination Survey

Although sleep duration has been extensively studied in metabolic diseases, few studies have investigated the impact of sleep duration on chronic kidney disease. The aim of this study was to examine the relationship between sleep duration and albuminuria in the general population. Among 24,948 adults who participated in the 2011–2014 KNHANES, a total of 19,994 subjects were included in this analysis. Subjects were categorized into the following five groups according to self-reported sleep duration: less than 5 h, 6 h, 7 h, 8 h, and more than 9 h. The association between sleep duration and urinary albumin-creatinine ratio (UACR) was examined cross-sectionally. Subjects with both short and long sleep durations were significantly associated with higher UACR levels and higher proportions of patients with microalbuminuria (30–299 mg/g) and macroalbuminuria (≥300 mg/g) compared to those with a sleep duration of 7 hours. The U-shaped association between sleep duration and UACR remained significant even after adjustment for potential confounders, including age, sex, body mass index, smoking, alcohol, education, income, exercise, estimated glomerular filtration rate, diabetes mellitus, hypertension and hypercholesterolemia. The U-shaped association is more evident in the subgroup aged 65 or older, or in female subjects. Our findings suggest that both short and long sleep durations have a U-shaped association with UACR levels in the general population, independent of potential confounders.

Objective Sleep Duration Is Prospectively Associated With Endothelial Health

Study Objectives

The mechanisms linking short sleep duration to cardiovascular disease (CVD) are poorly understood. Emerging evidence suggests that endothelial dysregulation may lie along the causal pathway linking sleep duration to cardiovascular risk, although current evidence in humans is based on cross-sectional studies. Our objective was to evaluate the prospective association between objectively assessed sleep duration and clinical indices of endothelial health.

Methods

A total of 141 medically healthy adults underwent an overnight laboratory sleep study when they were between the ages of 21 and 60 years. Total sleep time was objectively assessed by polysomnography at study entry. Endothelial health, including brachial artery diameter (BAD) and flow-mediated dilation (FMD), was measured 18.9 ± 4.6 years later. Medical health and psychiatric status were assessed at both time points. Approximately half of the sample had a lifetime history of major depressive disorder.

Results

In univariate analyses, shorter sleep duration was associated with increased BAD (β = -0.24, p = .004) and decreased FMD (β = 0.17, p = .042). BAD, but not FMD, remained significantly associated with sleep duration after adjusting for sex, age, body mass index (BMI), smoking, diabetes, hypertension, and lifetime history of major depressive disorder (MDD) at T2. The association between sleep duration and BAD was stronger than the association between BAD and an aggregate measure of CVD risk including three or more of the following risk factors: male sex, age ≥ 65 years, smoker, BMI ≥ 30, diabetes, hypertension, and MDD.

Conclusions

Objectively assessed short sleep duration was prospectively associated with increased BAD over a 12- to 30-year period.

Association of Subjective and Objective Sleep Duration as well as Sleep Quality with Non-Invasive Markers of Sub-Clinical Cardiovascular Disease (CVD): A Systematic Review

Aim: Abnormal daily sleep duration and quality have been linked to hypertension, diabetes, stroke, and overall cardiovascular disease (CVD) morbidity & mortality. However, the relationship between daily sleep duration and quality with subclinical measures of CVD remain less well studied. This systematic review evaluated how daily sleep duration and quality affect burden of subclinical CVD in subjects free of symptomatic CVD.

Methods: Literature search was done via MEDLINE, EMBASE, Web of Science until June 2016 and 32 studies met the inclusion criteria. Sleep duration and quality were measured either via subjective methods, as self-reported questionnaires or Pittsburg Sleep Quality Index (PSQI) or via objective methods, as actigraphy or polysomnography or by both. Among subclinical CVD measures, coronary artery calcium (CAC) was measured by electron beam computed tomography, Carotid intima-media thickness (CIMT) measured by high-resolution B-mode ultrasound on carotid arteries, endothelial/microvascular function measured by flow mediated dilation (FMD) or peripheral arterial tone (PAT) or iontophoresis or nailfold capillaroscopy, and arterial stiffness measured by pulse wave velocity (PWV) or ankle brachial index (ABI).

Results: Subjective short sleep duration was associated with CAC and CIMT, but variably associated with endothelial dysfunction (ED) and arterial stiffness; however, subjective long sleep duration was associated with CAC, CIMT and arterial stiffness, but variably associated with ED. Objective short sleep duration was positively associated with CIMT and variably with CAC but not associated with ED. Objective long sleep duration was variably associated with CAC and CIMT but not associated with ED. Poor subjective sleep quality was significantly associated with ED and arterial stiffness but variably associated with CAC and CIMT. Poor objective sleep quality was significantly associated with CIMT, and ED but variably associated with CAC.

Conclusions: Overall, our review provided mixed results, which is generally in line with published literature, with most of the studies showing a significant relationship with subclinical CVD, but only some studies failed to demonstrate such an association. Although such mechanistic relationship needs further evaluation in order to determine appropriate screening strategies in vulnerable populations, this review strongly suggested the existence of a relationship between abnormal sleep duration and quality with increased subclinical CVD burden.

Blood-Brain Barrier Disruption Induced by Chronic Sleep Loss: Low-Grade Inflammation May Be the Link

Sleep is a vital phenomenon related to immunomodulation at the central and peripheral level. Sleep deficient in duration and/or quality is a common problem in the modern society and is considered a risk factor to develop neurodegenerative diseases. Sleep loss in rodents induces blood-brain barrier disruption and the underlying mechanism is still unknown. Several reports indicate that sleep loss induces a systemic low-grade inflammation characterized by the release of several molecules, such as cytokines, chemokines, and acute-phase proteins; all of them may promote changes in cellular components of the blood-brain barrier, particularly on brain endothelial cells. In the present review we discuss the role of inflammatory mediators that increase during sleep loss and their association with general disturbances in peripheral endothelium and epithelium and how those inflammatory mediators may alter the blood-brain barrier. Finally, this manuscript proposes a hypothetical mechanism by which sleep loss may induce blood-brain barrier disruption, emphasizing the regulatory effect of inflammatory molecules on tight junction proteins.

Associations of a Short Sleep Duration, Insufficient Sleep, and Insomnia with Self-Rated Health among Nurses

Epidemiological evidence suggests that sleep duration and poor sleep are associated with mortality, as well as with a wide range of negative health outcomes. However, few studies have examined the association between sleep and self-rated health, particularly through the combination of sleep complaints. The objective of this study was to examine whether self-rated health is associated with sleep complaints, considering the combination of sleep duration, insomnia, and sleep sufficiency. This cross-sectional study was performed in the 18 largest public hospitals in the city of Rio de Janeiro, Brazil. A total of 2518 female nurses answered a self-filled multidimensional questionnaire. The adjusted odds ratios and 95% confidence intervals (CIs) estimated the chance of poor self-rated health in the presence of different combinations of sleep duration and quality. Compared with women who reported adequate sleep duration with no sleep quality complaints (reference group), the odds ratios (95% CI) for poor self-rated health were 1.79 (1.27–2.24) for those who reported only insufficient sleep, 1.85 (0.94–3.66) for only a short sleep duration, and 3.12 (1.94–5.01) for only insomnia. Compared with those who expressed all three complaints (short sleep duration, insomnia, and insufficient sleep), the odds ratio for poor self-rated health was 4.49 (3.25–6.22). Differences in the magnitude of the associations were observed, depending on the combination of sleep complaints. Because self-rated health is a consistent predictor of morbidity, these results reinforce the increasing awareness of the role of sleep in health and disease. Our findings contribute to the recognition of sleep as a public health matter that deserves to be better understood and addressed by policymakers.

Sleep duration and chronic kidney disease: analysis of the national health interview survey

BACKGROUND

Patients with chronic kidney disease (CKD) have a high prevalence of sleep disorders. The association between sleep duration and self-reported CKD was examined in a population of Americans who participated in a national survey over a 3-year period.

STUDY DESIGN

A cross-sectional study using survey data from the National Health Interview Survey (NHIS) from the year 2004-2006 was carried out. A retrospective examination of data from a community-based survey of 128,486 noninstitutionalized US civilian residents over the age of 18 years was conducted. Self-reported CKD was defined as having 'weak or failing kidneys'. The sleep duration was defined by a self-reported estimate of habitual sleep duration.

RESULTS

The prevalence of participants self-reporting kidney disease was higher in those with short (≤6 h per night) and long (≥8 h per night) sleep durations when compared to those sleeping 7 h per night. Self-reported information about sleep, demographic information, and information on comorbidities were assessed using standardized validated questionnaires which reported no kidney disease. A multivariate logistic regression analysis showed increased odds of self-reported kidney disease in study participants with both short and long sleep durations compared to healthy sleepers (sleeping >7-8 h per night). Observational data do not permit examination of causality, although possible confounders in observations of interest can be adjusted.

CONCLUSION

Among Americans surveyed in the NHIS (2004-2006), those with short or long sleep duration had higher odds of reporting that they had CKD.

Sleep and exercise: a reciprocal issue?

Sleep and exercise influence each other through complex, bilateral interactions that involve multiple physiological and psychological pathways. Physical activity is usually considered as beneficial in aiding sleep although this link may be subject to multiple moderating factors such as sex, age, fitness level, sleep quality and the characteristics of the exercise (intensity, duration, time of day, environment). It is therefore vital to improve knowledge in fundamental physiology in order to understand the benefits of exercise on the quantity and quality of sleep in healthy subjects and patients. Conversely, sleep disturbances could also impair a person's cognitive performance or their capacity for exercise and increase the risk of exercise-induced injuries either during extreme and/or prolonged exercise or during team sports. This review aims to describe the reciprocal fundamental physiological effects linking sleep and exercise in order to improve the pertinent use of exercise in sleep medicine and prevent sleep disorders in sportsmen.

Self-reported habitual short sleep duration is associated with endothelial fibrinolytic dysfunction in men: a preliminary report

STUDY OBJECTIVES

Habitual short sleep duration is associated with increased cardiovascular disease morbidity and mortality resulting from atherothrombotic events. The mechanisms responsible for this heightened cardiovascular risk are not fully understood. The capacity of the endothelium to release tissue-type plasminogen activator (t-PA), the primary activator of the fibrinolytic system, is a key endogenous defense mechanism against intravascular fibrin deposition and thrombosis. We tested the hypothesis that endothelial t-PA release is impaired in adults who sleep less than 7 h/night compared with adults who sleep between 7 and 9 h/night.

DESIGN

THIRTY ADULT MEN WERE STRATIFIED BASED ON AVERAGE NIGHTLY HABITUAL SLEEP DURATION: 15 with normal sleep duration (age: 55 ± 2 years; sleep duration: 7.6 h/night) and 15 with short sleep duration (56 ± 2 years; 6.1 h/night). Net endothelial release of t-PA was determined, in vivo, in response to intra-brachial infusions of bradykinin (12.5-50.0 ng/100 mL tissue/min) and sodium nitroprusside (1.0-4.0 μg/100 mL tissue/min).

MEASUREMENTS AND RESULTS

Net endothelial t-PA release to bradykinin was significantly lower (∼25%) in the short (from 0.4 ± 0.8 to 41.5 ± 4.3 ng/100 mL tissue/min) compared with the normal (0.4 ± 0.5 to 64.9 ± 6.7 ng/100 mL/tissue/min) sleep duration group. Furthermore, there was an inverse relation between average nightly sleep duration and peak t-PA release to bradykinin (r = 0.36, P < 0.05).

CONCLUSIONS

Endothelial t-PA release is impaired in adults who report short habitual sleep duration. Impaired endothelial fibrinolytic function may underlie the increased atherothrombotic risk associated with chronic short sleep.

Insomnia and endothelial function - the HUNT 3 fitness study

Background

Insomnia is associated with increased risk of coronary heart disease (CHD), but the underlying mechanisms are not understood. To our knowledge, no previous studies have examined insomnia in relation to endothelial function, an indicator of preclinical atherosclerosis. Our aim was to assess the association of insomnia with endothelial function in a large population based study of healthy individuals.

Methods

A total of 4 739 participants free from known cardiovascular or pulmonary diseases, cancer, and sarcoidosis, and who were not using antihypertensive medication were included in the study. They reported how often they had experienced difficulties falling asleep at night, repeated awakenings during the night, early awakenings without being able to go back to sleep, and daytime sleepiness. Endothelial function was measured by flow mediated dilation (FMD) derived from the brachial artery.

Results

We found no consistent association between the insomnia symptoms and endothelial function in multiadjusted models, but individual insomnia symptoms may be related to endothelial function. Among women who reported early awakenings, endothelial function may be lower than in women without this symptom (p = 0.03).

Conclusions

This study provided no evidence that endothelial function, an early indicator of atherosclerosis, is an important linking factor between insomnia and CHD. Further studies are needed to explore the complex interrelation between sleep and cardiovascular pathology.

Total sleep deprivation alters cardiovascular reactivity to acute stressors in humans

Exaggerated cardiovascular reactivity to mental stress (MS) and cold pressor test (CPT) has been linked to increased risk of cardiovascular disease. Recent epidemiological studies identify sleep deprivation as an important risk factor for hypertension, yet the relations between sleep deprivation and cardiovascular reactivity remain equivocal. We hypothesized that 24-h total sleep deprivation (TSD) would augment cardiovascular reactivity to MS and CPT and blunt the MS-induced forearm vasodilation. Because the associations between TSD and hypertension appear to be stronger in women, a secondary aim was to probe for sex differences. Mean arterial pressure (MAP), heart rate (HR), and muscle sympathetic nerve activity (MSNA) were recorded during MS and CPT in 28 young, healthy subjects (14 men and 14 women) after normal sleep (NS) and 24-h TSD (randomized, crossover design). Forearm vascular conductance (FVC) was recorded during MS. MAP, FVC, and MSNA (n = 10) responses to MS were not different between NS and TSD (condition × time, P > 0.05). Likewise, MAP and MSNA (n = 6) responses to CPT were not different between NS and TSD (condition × time, P > 0.05). In contrast, increases in HR during both MS and CPT were augmented after TSD (condition × time, P ≤ 0.05), and these augmented HR responses persisted during both recoveries. When analyzed for sex differences, cardiovascular reactivity to MS and CPT was not different between sexes (condition × time × sex, P > 0.05). We conclude that TSD does not significantly alter MAP, MSNA, or forearm vascular responses to MS and CPT. The augmented tachycardia responses during and after both acute stressors provide new insight regarding the emerging links among sleep deprivation, stress, and cardiovascular risk.

White blood cell count and endothelin-1 vasoconstrictor tone in middle-aged and older adults

BACKGROUND

Higher white blood cell (WBC) count is associated with impaired endothelium-dependent vasodilation. However, the influence of higher WBC count on endothelin (ET)-1 vasoconstrictor activity is currently unknown. We tested the hypothesis that adults with elevated WBC count demonstrate enhanced ET-1 system activity.

METHODS

Thirty-four healthy adults were studied: 17 with WBC count < 5.0 × 10⁹ cells/L (lower WBC; 9M/8F; age: 53 ± 2 yr) and 17 with WBC count > 5.0 × 10⁹ cells/L (higher WBC; 10M/7F; 54 ± 3 yr). Forearm blood flow (FBF) responses to intra-brachial infusion of ET-1 (5 pmol/min for 20 min) and selective ET_A receptor blockade (BQ-123; 100 nmol/min for 60 min) were measured by venous occlusion plethysmography.

RESULTS

The vasoconstrictor response to ET-1 was significantly blunted (∼60%) in the higher WBC group versus the lower WBC group. The FBF responses to selective ET_A receptor blockade were also significantly different (P < 0.05) between the groups. In the lower WBC group, resting FBF increased marginally (∼5%) to BQ-123, whereas the increase in FBF to BQ-123 was significantly greater (∼15%) in higher WBC group. Furthermore, there was a significant relation between WBC count and FBF response to ET-1 (r = -0.43) and BQ-123 (r = 0.41).

CONCLUSIONS

Relative elevations in WBC count in middle-aged and older adults, independent of adiposity and other cardiometabolic risk factors, are associated with enhanced ET-1-mediated vasoconstrictor tone. Elevated ET-1 system activity may be a mechanism linking higher WBC count with increased cardiovascular risk.

Habitual short sleep duration and circulating endothelial progenitor cells

Chronic short sleep duration has been linked to endothelial dysfunction and increased risk of cardiovascular disease. Circulating endothelial progenitor cells (EPCs) are vital to endogenous vascular repair processes and cardiovascular health. We tested the hypothesis that habitual short sleep duration is associated with impairment in EPC number and function. Cells with phenotypic EPC characteristics were isolated from 37 healthy, sedentary adults: 20 with normal sleep duration (13M/7F; age: 59±1 years; sleep duration: 7.7±0.1 h/night) and 17 with short sleep duration (9M/8F; 56±2 years; 6.0±0.2 h/night). EPC number was assessed by flow cytometric analysis of the percentage of peripheral blood mononuclear cells negative for CD45 and positive for CD34, VEGFR-2, and CD133 antigens. EPC colony-forming capacity was determined by colony-forming unit (CFU) assay; migration by Boyden chamber; and intracellular caspase-3 concentrations by immunoassay. There were no significant differences between groups in EPC number (0.001±0.0004 vs. 0.001±0.0003 %), colony-forming capacity (6.1±1.5 vs. 5.4±1.7 CFUs), or migration to VEGF (1410.1±151.2 vs. 1334.3±111.1 AU). Furthermore, there were no group differences in basal and staurosporine-stimulated intracellular concentrations of active caspase-3 (0.3±0.03 vs. 0.5±0.1 ng/mL; and 2.9±0.4 vs. 2.7±0.3 ng/mL), a marker of apoptotic susceptibility. Taken together, these data indicate that short sleep duration is not associated with EPC dysfunction in healthy adults. Numerical and functional impairment in circulating EPCs may not contribute to the increased cardiovascular risk with habitual short sleep duration.