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

Very short sleep duration reveals a proteomic fingerprint that is selectively associated with incident diabetes mellitus but not with incident coronary heart disease: a cohort study

BACKGROUND

The molecular pathways linking short and long sleep duration with incident diabetes mellitus (iDM) and incident coronary heart disease (iCHD) are not known. We aimed to identify circulating protein patterns associated with sleep duration and test their impact on incident cardiometabolic disease.

METHODS

We assessed sleep duration and measured 78 plasma proteins among 3336 participants aged 46-68 years, free from DM and CHD at baseline, and identified cases of iDM and iCHD using national registers. Incident events occurring in the first 3 years of follow-up were excluded from analyses. Tenfold cross-fit partialing-out lasso logistic regression adjusted for age and sex was used to identify proteins that significantly predicted sleep duration quintiles when compared with the referent quintile 3 (Q3). Predictive proteins were weighted and combined into proteomic scores (PS) for sleep duration Q1, Q2, Q4, and Q5. Combinations of PS were included in a linear regression model to identify the best predictors of habitual sleep duration. Cox proportional hazards regression models with sleep duration quintiles and sleep-predictive PS as the main exposures were related to iDM and iCHD after adjustment for known covariates.

RESULTS

Sixteen unique proteomic markers, predominantly reflecting inflammation and apoptosis, predicted sleep duration quintiles. The combination of PSQ1 and PSQ5 best predicted sleep duration. Mean follow-up times for iDM (n = 522) and iCHD (n = 411) were 21.8 and 22.4 years, respectively. Compared with sleep duration Q3, all sleep duration quintiles were positively and significantly associated with iDM. Only sleep duration Q1 was positively and significantly associated with iCHD. Inclusion of PSQ1 and PSQ5 abrogated the association between sleep duration Q1 and iDM. Moreover, PSQ1 was significantly associated with iDM (HR = 1.27, 95% CI: 1.06-1.53). PSQ1 and PSQ5 were not associated with iCHD and did not markedly attenuate the association between sleep duration Q1 with iCHD.

CONCLUSIONS

We here identify plasma proteomic fingerprints of sleep duration and suggest that PSQ1 could explain the association between very short sleep duration and incident DM.

Negative Influence of Insufficient Sleep on Endothelial Vasodilator and Fibrinolytic Function in Hypertensive Adults

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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.

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.

Time of day, but not sleep restriction, affects markers of hemostasis following heavy exercise

We sought to determine the effects of sleep restriction on markers of hemostasis the morning after an exercise session. Seven subjects performed evening exercise followed by an exercise session the next morning, both with and without sleep restriction. Evening exercise included a 20-min submaximal cycling trial (10 min at 50% maximal power (W_max), 10 min at 60% W_max), a 3-km cycling time trial, 60 min of cycling intervals, and 3 sets of leg press. Subsequent morning exercise was the same, excluding intervals and leg press. Blood samples were collected at rest and following the 20-min submaximal trial for factor VIII antigen, tissue plasminogen activator (tPA) activity, and plasminogen activator inhibitor-1 (PAI-1) activity. Sleep restriction had no effect on the variables. Factor VIII antigen was higher and tPA activity lower in the morning versus evening, respectively (P < 0.05). There were larger (P < 0.05) exercise responses for tPA activity in the evening (pre-exercise = 0.32 ± 0.14, postexercise = 1.89 ± 0.60 AU/mL) versus morning (pre-exercise = 0.27 ± 0.13 AU/mL, postexercise = 0.69 ± 0.18 AU/mL). PAI-1 exhibited lower (P < 0.05) responses in the evening (pre-exercise = 0.78 ± 0.26 AU/mL, postexercise = 0.69 ± 0.29 AU/mL) versus morning (pre-exercise = 7.06 ± 2.66, postexercise = 5.40 ± 2.31 AU/mL). Although a prothrombotic environment was observed the morning following an evening exercise session, it was not exacerbated by sleep restriction.

The effect of sleep duration on exhaled nitric oxide levels in U.S. adults

PURPOSE

Poor sleep quality and duration are associated with systemic endothelial dysfunction. However, an association between poor sleep and pulmonary endothelial dysfunction has not been elucidated. We sought to determine if there is a relationship between sleep duration and fractional exhaled nitric oxide (FeNO) concentrations as a surrogate for pulmonary endothelial function.

METHODS

We used three National Health and Nutrition Examination Survey (NHANES) cycles (2007-2012). Linear regression models were built with and without adjustment for age, sex, race, BMI, asthma/bronchitis, CRP, smoking, folate, renal function, respiratory infections, and steroid use. To examine a non-linear relationship, we introduced a spline, with single knot at mean sleep duration (7 h).

RESULTS

Of 13,173 participants (50.8% male, 44.2% Caucasian), 78% slept 6-8 hours (h). FeNO was significantly higher in the group sleeping 6-8 h (17.3 ± 14.9 ppb) than in the other two groups (16.0 ± 13.0 ppb, 15.9 ± 12.7 ppb for <6 and >8 h respectively; P < 0.001). In unadjusted linear regression, FeNO increased by 1.1 ppb for each hour increase in sleep up to 7 h (P < 0.001). Increased sleep duration beyond 7 h saw a 0.96 ppb decrease in FeNO (P < 0.001). After adjustment for confounders, FeNO increased by 1.09 ppb for each hour of sleep up to 7 h (P = 0.001) and decreased by 0.71 ppb for each hour after (P = 0.02).

CONCLUSION

Sleeping less or more than 7 h is associated with pulmonary endothelial dysfunction as measured by FeNO. Further study is needed to evaluate mechanism(s) of this association and validity of FeNO as a marker of endothelial function.

Association between sleep condition and arterial stiffness in Chinese adult with nonalcoholic fatty liver disease

Nonalcoholic fatty liver (NAFLD) usually has worse cardiovascular risk factors. Given the potential association between deterioration of sleep and arterial stiffness, we aim to investigate the association between deterioration of sleep and arterial stiffness in a middle-aged Chinese population with NAFLD. In this cross-sectional study, 15,372 Chinese aged 40-60 years who participated in periodic health checkups in central south China, were included. Self-reported sleep duration and sleep quality, anthropometric, biochemical, and liver ultrasound scan were analyzed and brachial-ankle pulse wave velocity (baPWV) was used as the indicator of arterial stiffness. Poor sleep quality was found to be associated with increased arterial stiffness, with odds ratios and 95 % confidence intervals (CIs) of 2.28 (95 % CI, 1.53-3.38) compared with good sleep quality. Using sleep duration ≥ 8 h as the reference, there was no significant association between sleep duration of ≤ 6 or 6-8 h and arterial stiffness after multivariable-adjusted. In additional analyses, further investigation of the association of different combinations of sleep duration and quality in relation to arterial stiffness indicated participants with poor sleep quality and sleep duration ≤ 6 h were more likely to have arterial stiffness than those with good quality sleep who sleep for ≥ 8 h (OR 2.59, 95 % CI 1.58-4.24). The present study indicates that short sleep duration, poor sleep quality in individuals with NAFLD correlate with increased arterial stiffness.

Influence of sleep disturbances on age at onset and long-term incidence of major cardiovascular events: the MONICA-Brianza and PAMELA cohort studies

OBJECTIVE

We examined the prospective associations of sleep disturbances and sleep duration with the long-term incidence of major cardiovascular disease (CVD) events, in a large cohort of Italian adult men.

METHODS

A total of 2277 men aged 35-74 years of age and CVD free at baseline from the MONICA-Brianza and PAMELA population-based cohorts were followed up for a median of 17 years, for first coronary heart disease (CHD) or ischemic stroke events (fatal or nonfatal; n = 293). Sleep disturbances, based on the Jenkins Sleep Questionnaire, were categorized as none/some, moderate, or severe. Sleep durations were ≤6 hours (short), seven to eight hours, and ≥9 hours (long) per night.

RESULTS

At baseline, 855 men (38%) either reported sleep disturbances or were short or long sleepers. The presence of severe sleep disturbances increased the risk of first CVD (hazard ratio [HR] = 1.80, 95% confidence interval [CI] = 1.07-3.03) and CHD events (HR = 1.97, 95% CI = 1.09-3.56), in particular from the age of 48 years onward. In comparison to men sleeping seven to eight hours, long sleepers experienced a higher CVD risk (HR = 1.56, 95% CI = 1.10-2.22), due mainly to ischemic strokes, and starting at older ages (≥60 years). A joint effect between disturbed sleep and short sleep duration on CVD and CHD events was also observed. Adjustments for physical activity and depression did not substantially modify these associations.

CONCLUSION

Severe sleep disturbances and long sleep duration were associated with specific CVD endpoints and age at onset, potentially suggesting distinct underlying mechanisms. A short questionnaire discriminating different levels of sleep disturbances and sleep duration should be routinely adopted in CVD prevention programs to identify men at increased risk for early-onset events.

Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society on the Recommended Amount of Sleep for a Healthy Adult: Methodology and Discussion

The American Academy of Sleep Medicine and Sleep Research Society recently released a Consensus Statement regarding the recommended amount of sleep to promote optimal health in adults. This paper describes the methodology, background literature, voting process, and voting results for the consensus statement. In addition, we address important assumptions and challenges encountered during the consensus process. Finally, we outline future directions that will advance our understanding of sleep need and place sleep duration in the broader context of sleep health.

Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society on the Recommended Amount of Sleep for a Healthy Adult: Methodology and Discussion

The American Academy of Sleep Medicine and Sleep Research Society recently released a Consensus Statement regarding the recommended amount of sleep to promote optimal health in adults. This paper describes the methodology, background literature, voting process, and voting results for the consensus statement. In addition, we address important assumptions and challenges encountered during the consensus process. Finally, we outline future directions that will advance our understanding of sleep need and place sleep duration in the broader context of sleep health.

Influence of sleep deprivation and circadian misalignment on cortisol, inflammatory markers, and cytokine balance

Cortisol and inflammatory proteins are released into the blood in response to stressors and chronic elevations of blood cortisol and inflammatory proteins may contribute to ongoing disease processes and could be useful biomarkers of disease. How chronic circadian misalignment influences cortisol and inflammatory proteins, however, is largely unknown and this was the focus of the current study. Specifically, we examined the influence of weeks of chronic circadian misalignment on cortisol, stress ratings, and pro- and anti-inflammatory proteins in humans. We also compared the effects of acute total sleep deprivation and chronic circadian misalignment on cortisol levels. Healthy, drug free females and males (N=17) aged 20-41 participated. After 3weeks of maintaining consistent sleep-wake schedules at home, six laboratory baseline days and nights, a 40-h constant routine (CR, total sleep deprivation) to examine circadian rhythms for melatonin and cortisol, participants were scheduled to a 25-day laboratory entrainment protocol that resulted in sleep and circadian disruption for eight of the participants. A second constant routine was conducted to reassess melatonin and cortisol rhythms on days 34-35. Plasma cortisol levels were also measured during sampling windows every week and trapezoidal area under the curve (AUC) was used to estimate 24-h cortisol levels. Inflammatory proteins were assessed at baseline and near the end of the entrainment protocol. Acute total sleep deprivation significantly increased cortisol levels (p<0.0001), whereas chronic circadian misalignment significantly reduced cortisol levels (p<0.05). Participants who exhibited normal circadian phase relationships with the wakefulness-sleep schedule showed little change in cortisol levels. Stress ratings increased during acute sleep deprivation (p<0.0001), whereas stress ratings remained low across weeks of study for both the misaligned and synchronized control group. Circadian misalignment significantly increased plasma tumor necrosis factor-alpha (TNF-α), interleukin 10 (IL-10) and C-reactive protein (CRP) (p<0.05). Little change was observed for the TNF-α/IL-10 ratio during circadian misalignment, whereas the TNF-α/IL-10 ratio and CRP levels decreased in the synchronized control group across weeks of circadian entrainment. The current findings demonstrate that total sleep deprivation and chronic circadian misalignment modulate cortisol levels and that chronic circadian misalignment increases plasma concentrations of pro- and anti-inflammatory proteins.