Endothelial function and sleep: associations of flow-mediated dilation with perceived sleep quality and rapid eye movement (REM) sleep

Enhanced external counterpulsation improves sleep quality in chronic insomnia: A pilot randomized controlled study

PURPOSE

To investigate the short-term efficacy of enhanced external counterpulsation (EECP) on chronic insomnia.

METHODS

This is a pilot randomized, participant-blind, and sham-controlled study. Forty-six participants with chronic insomnia were randomly assigned in a 1:1 ratio to receive EECP or sham EECP intervention (total of 35 sessions with 45 min each). The primary outcome was Pittsburgh Sleep Quality Index (PSQI). The secondary outcomes included sleep diary, Hospital Anxiety and Depression Scale (HADS), Short-Form Health Survey (SF12), flow mediated dilation (FMD), serum biomarkers of melatonin, cortisol, interleukin-6, and high sensitivity C-reactive protein. Outcomes were assessed after treatment and at 3-month follow-up.

RESULTS

The PSQI was significantly decreased in both EECP and sham groups after 35-session intervention (13.74 to 6.96 in EECP and 13.04 to 9.48 in sham), and EECP decreased PSQI more than sham EECP (p = 0.009). PSQI in two groups kept improved at 3-month follow-up. After treatment, the total sleep time, sleep efficiency, FMD value and SF12 mental component of EECP group were significantly improved, and group differences were found for these outcomes. At follow-up, total sleep time, sleep efficiency and SF12 mental component of EECP group remained improved, and group difference for SF12 mental component was found. Post-treatment and follow-up HADS-A significantly decreased in both groups, with no differences between groups. Post-treatment serum biomarkers showed no differences within and between groups.

LIMITATION

Lack of objective sleep measurement.

CONCLUSION

EECP could improve sleep quality and mental quality of life in chronic insomnia and the therapeutic effect maintained for 3 months.

Berry Consumption and Sleep in the Adult US General Population: Results from the National Health and Nutrition Examination Survey 2005-2018

INTRODUCTION

Poor sleep is associated with numerous adverse health outcomes. Berries are rich in micronutrients and antioxidants that may improve sleep quality and duration. We determined the association of berry consumption and sleep duration and sleep difficulty among adult participants in NHANES.

METHODS

We analyzed the diet of US adults aged ≥ 20 y using two non-consecutive 24 h recalls from the National Health and Nutrition Examination Survey 2005 to 2018 (N = 29,217). Poor sleep quality was measured by sleep duration (short sleep duration: <7 h), long sleep (≥9 h), and reported sleep difficulty. The relative risk of poor sleep outcomes for berry consumers vs. nonconsumers was modelled using population weight-adjusted multivariable general logistic regression.

RESULTS

About 46% of participants reported inadequate sleep duration, and 27% reported sleep difficulties. Twenty-two percent reported consuming berries. Berry consumers had a 10-17% decreased risk of short sleep. The findings were consistent for specific berry types including strawberries and blueberries (p < 0.05). No significant associations with long sleep were found for total berries and any berry types. A decreased risk of sleep difficulties was found to be linked to blackberry consumption (adjusted OR = 0.63, 95% CI: 0.40-0.97; p = 0.036) but not for other berries.

CONCLUSIONS

US adult berry consumers had a decreased risk of reporting short sleep compared to nonconsumers. Berries are underconsumed foods in the US adult population, and increased berry consumption may improve sleep quality.

Dietary polyphenols and sleep modulation: Current evidence and perspectives

Polyphenols are plant compounds with several biological activities. This review aims to summarize current knowledge on the potential role of polyphenols in modulating sleep. A total of 28 preclinical studies, 12 intervention studies and four observational studies exploring the role of polyphenol intake on sleep were identified. From animal studies, 26 out of the 28 studies found beneficial effects of polyphenols on sleep architecture. Three out of four human observational studies found a beneficial association between polyphenol intake and sleep parameters. And, among clinical intervention studies, eight from a total of 12 studies found some beneficial effect of polyphenol intake on various sleep parameters, although some discrepancies between studies were found. Overall, emerging evidence suggests a benefit of polyphenol intake on sleep. Several mechanisms of action have been suggested, ranging from effects on neurotransmitters to an action through the gut-brain axis. However, more research in this field is needed, emphasizing the use of nutritional doses in mechanistic studies and interventions targeting participants with sleep problems. This would allow to elucidate whether an additional biological effect of polyphenols is modulation of sleep, a behavior associated with adverse health outcomes.

Chrononutrition behaviors, sugar-sweetened beverage consumption, sleep quality and the association with body mass index among Malaysian women

The present study aimed to determine the association between chrononutrition behaviors, sugar-sweetened beverage intake, and sleep quality among Malaysian women. A cross-sectional study using a validated, self-administered Chrononutrition Profile Questionnaire, Beverage Questionnaire and Sleep Quality Index were conducted among 934 Malaysian women. Multinomial logistic regression was performed to obtain odds ratios of being overweight/underweight and to test the association with poor sleep quality. 40% of Malaysian women were either overweight or obese and 65.4% had poor sleep quality. We found that breakfast skipping (OR: 4.101; CI: 2.378-7.070), poor evening eating (OR: 4.073; CI: 1.631-10.186), and eating the largest meal at night (OR: 6.970; CI: 1.944-24.994) increased the odds of being underweight. On the other hand, the daily consumption of 100% fruit juices (OR: 1.668; CI: 1.058-1.731), daily consumption of sweetened coffee or tea (OR: 1.707; CI: 1.162-2.508) and consumption of diet soft drinks by 6 times or fewer (OR: 1.484; CI: 1.066-2.064) are associated with increased odds of being overweight. However, when adjusted, only poor evening latency (AOR: 16.638; CI: 1.986-139.383) revealed an increased odd of being underweight. The highest odds predicting poor sleep quality were found for eating the largest meal during dinner (OR: 3.696; CI: 1.967-6.945) and (AOR: 2.194; CI: 1.119-4.304) when adjusted. Hence, the result indicates that multifactorial impacts on women's body weight and recommendations to adjust chrononutrition and sugar-sweetened beverages intake in lifestyle must be done carefully considering other parameters together.

Sleep measures and cardiovascular disease in type 2 diabetes mellitus

OBJECTIVE

The objective of this study was to assess whether poor sleep is independently associated with cardiovascular disease in people with type 2 diabetes mellitus (T2DM).

METHODS

A cross-sectional study was performed in subjects with T2DM aged between 40 and 80 years. Sleep assessment was achieved by actigraphy and Pittsburgh Sleep Quality Index (PSQI) score.

RESULTS

The study population comprised 108 subjects with T2DM. The mean age was 64.9 years, the median diabetes duration was 6 years and 73.1% were men. No association was shown between sleep parameters as assessed by actigraphy and T2DM-associated micro- and macrovascular complications. However, sleep quality as assessed by PSQI was significantly associated with macrovascular disease in univariate analysis. Multivariate logistic regression analysis showed red blood cell distribution width (RDW) (odds ratio (OR) 1.79, p=0.018) and good sleep quality (OR 0.35, p=0.017) to be independently associated. Binary logistic regression analysis revealed that body mass index (BMI) (OR 1.11, p=0.024), RDW (OR 1.95, p=0.007) and Center for Epidemiologic Studies Depression score (OR 1.06, p=0.012] were independently associated with abnormal carotid intima-media thickness (CIMT).

CONCLUSIONS

Poor sleep quality and higher RDW levels are associated with macrovascular disease in a T2DM population. Increased BMI as well as depression also appear to have an independent role in subclinical atherosclerosis, as assessed by CIMT.

Potential of Polyphenols for Improving Sleep: A Preliminary Results from Review of Human Clinical Trials and Mechanistic Insights

Global epidemiologic evidence supports an interrelationship between sleep disorders and fruits and vegetable ingestion. Polyphenols, a broad group of plant substances, are associated with several biologic processes, including oxidative stress and signaling pathways that regulate the expression of genes promoting an anti-inflammatory environment. Understanding whether and how polyphenol intake is related to sleep may provide avenues to improve sleep and contribute to delaying or preventing the development of chronic disease. This review aims to assess the public health implications of the association between polyphenol intake and sleep and to inform future research. The effects of polyphenol intake, including chlorogenic acid, resveratrol, rosmarinic acid, and catechins, on sleep quality and quantity are discussed to identify polyphenol molecules that may improve sleep. Although some animal studies have investigated the mechanisms underlying the effects of polyphenols on sleep, the paucity of trials, especially randomized controlled trials, does not allow for conducting a meta-analysis to reach clear conclusions about the relationships among these studies to support the sleep-improving effects of polyphenols.

Association Between Sleep Efficiency and Hypertension in Chinese Obstructive Sleep Apnea Patients

Objective

We aimed to explore the relationship of sleep efficiency (SE) with the prevalence of hypertension in Chinese obstructive sleep apnea (OSA) patients based on polysomnography (PSG) records.

Methods

We studied 2360 patients with OSA and 764 primary snorers who underwent PSG in our hospital. SE was divided into three grades, including ≥85%, 80%~84.9%, and <80%. Hypertension was defined based either on direct blood pressure measurements, under anti-hypertensive treatments or on physician diagnosis. Multivariate logistic regression models were conducted to investigate the association between SE and hypertension.

Results

After adjusting for potential confounding factors, OSA patients with <80% SE and those with 80% to 84.9% SE were significantly associated with the prevalence of hypertension (OR = 1.248, 95% CI 1.018~1.531, P=0.033; OR = 1.380, 95% CI 1.040~1.832, P=0.026). Compared to primary snorers, OSA combined with <85% SE increased the odds of hypertension. In stratified analysis by SE, risk of hypertension only in those with <80% SE was significantly different between OSA and primary snorers. Furthermore, this relationship between reduced SE and hypertension was evident especially in female, younger ages, obese, moderate and severe OSA patients. No significant relationship between reduced SE and hypertension was found in primary snores group.

Conclusion

We found that poor SE was correlated with the prevalence of hypertension in Chinese OSA patients, but not in those with primary snoring. Moreover, this relationship was evident especially in female, younger ages, obese, moderate and severe OSA patients.

Arterial Stiffness and Endothelial Function are Comparable in Young Healthy Vegetarians and Omnivores

Vegetarians (VEG) are reported to have lower body weight, blood pressure (BP), and cardiovascular disease (CVD) risk compared with omnivores (OMN), yet the mechanisms remain unclear. A vegetarian diet may protect the vascular endothelium, reducing the risk of atherosclerosis and CVD. This cross-sectional study compared vascular function between OMN and VEG. We hypothesized that VEG would have greater vascular function compared with OMN. Fifty-eight normotensive young healthy adults participated (40 women [W]/18 men [M]; 28 OMN [15W/13M] and 30 VEG [25W/5M]; 26 ± 7 years; BP: 112 ± 11/67 ± 8 mm Hg). Arterial stiffness, assessed by carotid-to-femoral pulse wave velocity (OMN: 5.6 ± 0.8 m/s, VEG: 5.3 ± 0.8 m/s; P = .17) and wave reflection assessed by aortic augmentation index (OMN: 6.9 ± 12.3%, VEG: 8.8 ± 13.5%; P = .57) were not different between groups. However, central pulse pressure (OMN: 32 ± 5; VEG: 29 ± 5 mm Hg; P = .048) and forward wave reflection were greater in omnivores (OMN: 26 ± 3; VEG: 24 ± 3 mm Hg; P = .048). Endothelial-dependent dilation measured by brachial artery flow-mediated dilation was not different between groups (OMN: 6.0 ± 2.9%, VEG: 6.9 ± 3.3%; P = .29). Percent change in femoral blood flow from baseline during passive leg movement, another assessment of nitric oxide-mediated endothelial dilation, was similar between groups (OMN: 203 ± 88 mL/min, VEG: 253 ± 192 mL/min; P = .50). These data suggest that in healthy young adults, normotensive VEG do not have significantly improved vascular function compared with OMN; however, they have a lower central pulse pressure and forward wave amplitude which may lower the risk of future CVD.

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.

Racial and ethnic disparities in cardiometabolic disease and COVID-19 outcomes in White, Black/African American, and Latinx populations: Social determinants of health

Racial and ethnic-related health disparities in the United States have been intensified by the greater burden of Coronavirus Disease 2019 (COVID-19) in racial and ethnic minority populations. Compared to non-Hispanic White individuals, non-Hispanic Black and Hispanic/Latinx individuals infected by COVID-19 are at greater risk for hospitalization, intensive care unit admission, and death. There are several factors that may contribute to disparities in COVID-19-related severity and outcomes in these minority populations, including the greater burden of cardiovascular and metabolic diseases as discussed in our companion review article. Social determinants of health are a critical, yet often overlooked, contributor to racial and ethnic-related health disparities in non-Hispanic Black and Hispanic/Latinx individuals relative to non-Hispanic White individuals. Thus, the purpose of this review is to focus on the essential role of social factors in contributing to health disparities in chronic diseases and COVID-19 outcomes in minority populations. Herein, we begin by focusing on structural racism as a social determinant of health at the societal level that contributes to health disparities through downstream social level (e.g., occupation and residential conditions) and individual level health behaviors (e.g., nutrition, physical activity, and sleep). Lastly, we conclude with a discussion of practical applications and recommendations for future research and public health efforts that seek to reduce health disparities and overall disease burden.

Endothelial Function and Arterial Stiffness Should Be Measured to Comprehensively Assess Obstructive Sleep Apnea in Clinical Practice

Objective: An effective clinical tool to assess endothelial function and arterial stiffness in patients with obstructive sleep apnea (OSA) is lacking. This study evaluated the clinical significance of subclinical markers for OSA management in males without serious complications.

Patients/Methods: Males without serious complications were consecutively recruited. Clinical data, biomarker tests, reactive hyperemia index (RHI), and augmentation index at 75 beats/min (AIx75) measured by peripheral arterial tonometry were collected. An apnea hypopnea index (AHI) cutoff of ≥15 events/h divided the patients into two groups.

Results: Of the 75 subjects, 42 had an AHI ≥15 events/h. Patients with an AHI ≥15 events/h had higher high-sensitivity C-reactive protein, tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor, and AIx75 values than the control group but no statistical difference in RHI was observed. After controlling for confounders, TNF-α was negatively correlated with the average oxygen saturation (r = −0.258, P = 0.043). RHI was correlated with the rapid eye movement (REM) stage percentage (r = 0.306, P = 0.016) but not with AHI (P > 0.05). AIx75 was positively correlated with the arousal index (r = 0.289, P = 0.023) but not with AHI (r = 0.248, P = 0.052).

Conclusions: In males with OSA without severe complications, TNF-α and AIx75 are independently related to OSA. The role of RHI in OSA management requires further elucidation. These markers combined can comprehensively evaluate OSA patients to provide more evidence for the primary prevention of coronary heart disease and treatment response assessment.

Does overnight duty affect vascular endothelial function?

BACKGROUND

The reactive hyperemia index (RHI), which is obtained from the measurement of peripheral arterial tonometry (PAT), is highly associated with the percentage change in the end-diastolic arterial diameter (%flow-mediated dilatation) at reactive hyperemia. Low RHI is reported to be a mortality risk in patients with a high risk of cardiovascular (CV) disease. CV events are thought to be induced by physical and mental stress, including long-term fatigue and lack of sleep. However, the relationship between fatigue, lack of sleep, and endothelial function has not yet been established.

METHODS

Healthy hospital workers (n = 13, 6 men and 7 women) with an average age of 31.6 years were assigned to this study after they provided written informed consent. During the study period, we conducted 72 measurements of reactive hyperemia-peripheral arterial tonometry (RH-PAT) in the morning before or after their duty. At each measurement of the RH-PAT, we recorded the participants' hours of sleep and evaluated their degree of fatigue using a visual analog scale (VAS).

RESULTS

Although the VAS was significantly less (36 ± 16% and 64 ± 12%, p < 0.001) and the hours of sleep were longer (6.0 ± 1.1 h and 2.3 ± 1.0 h, p < 0.001) before duty compared to those after duty, the RHI was comparable between them (2.12 ± 0.53 vs. 1.97 ± 0.50, p = 0.21). The VAS score was significantly higher in participants with low RHI (< 1.67) than in those with normal RHI (≥ 2.07) (59 ± 13% and 46 ± 21%, respectively, p < 0.05). However, binary logistic regression showed no significant association between low RHI and the VAS when adjusted for systemic blood pressure (SBP) and heart rate variability (HRV). In a simple regression analysis, the RHI was significantly correlated with the VAS score but not with sleep duration. A multiple linear regression analysis also showed no significant association between the RHI and VAS scores after adjustment for SBP and HRV.

CONCLUSIONS

Vascular endothelial function was not associated with overnight duty, hours of sleep, or degree of fatigue in healthy young adults. Since the RHI may be decreased in severe fatigue conditions through autonomic nerve activity, one should consider the physical and mental conditions of the examinee when evaluating the RH-PAT results.

Sleep Efficiency is Inversely Associated with Brachial Artery Diameter and Morning Blood Pressure in Midlife Adults, with a Potential Sex-Effect

PURPOSE

Sleep efficiency is inversely associated with cardiovascular risk. Brachial artery diameter and flow-mediated dilation (FMD) are noninvasive cardiovascular disease markers. We assessed the associations between sleep efficiency and these vascular markers in midlife adults, including people with sleep apnea.

PATIENTS AND METHODS

Thirty (18 males) participants completed an in-laboratory 8-hour sleep opportunity beginning at their habitual bedtimes. Polysomnography was used to assess sleep patterns and sleep efficiency (time asleep/time in bed). We measured systolic and diastolic blood pressure, heart rate, and baseline diameter, and FMD immediately upon awakening in the morning. Mixed model analyses, adjusting for apnea-hypopnea and body mass indices, were used to assess the relationship between overnight sleep efficiency and cardiovascular markers. We also explored sex differences.

RESULTS

Sleep efficiency was negatively associated with baseline brachial artery diameter (p = 0.005), systolic BP (p = 0.01), and diastolic BP (p = 0.02), but not flow-mediated dilation or heart rate (p > 0.05). These relationships were confirmed with correlations between sleep efficiency and baseline diameter (r = -0.52, p = 0.004), systolic BP (r = -0.43, p = 0.017), and diastolic BP (r = -0.43, p = 0.019). There was a sex-specific interaction trend for sleep efficiency and arterial diameter (p = 0.07) and a significant sex-specific interaction (p < 0.05) for BP, such that the relationships between sleep efficiency and cardiovascular markers were significant in women but not in men.

CONCLUSION

In midlife adults, poor sleep efficiency is associated with increased brachial artery diameter and blood pressure, effects that were primarily driven by significant associations in women. These associations could underlie the observed increase in cardiovascular risk in adults with poor sleep and cardiovascular disease.

Sleep quality and architecture in COPD: the relationship with lung function abnormalities

OBJECTIVE

Impaired respiratory mechanics and gas exchange may contribute to sleep disturbance in patients with COPD. We aimed to assess putative associations of different domains of lung function (airflow limitation, lung volumes, and gas exchange efficiency) with polysomnography (PSG)-derived parameters of sleep quality and architecture in COPD.

METHODS

We retrospectively assessed data from COPD 181 patients ≥ 40 years of age who underwent spirometry, plethysmography, and overnight PSG. Univariate and multivariate linear regression models predicted sleep efficiency (total sleep time/total recording time) and other PSG-derived parameters that reflect sleep quality.

RESULTS

The severity of COPD was widely distributed in the sample (post-bronchodilator FEV1 ranging from 25% to 128% of predicted): mild COPD (40.3%), moderate COPD (43.1%), and severe-very severe COPD (16.6%). PSG unveiled a high proportion of obstructive sleep apnea (64.1%) and significant nocturnal desaturation (mean pulse oximetry nadir = 82.2% ± 6.9%). After controlling for age, sex, BMI, apnea-hypopnea index, nocturnal desaturation, comorbidities, and psychotropic drug prescription, FEV1/FVC was associated with sleep efficiency (β = 25.366; R2 = 14%; p < 0.001), whereas DLCO predicted sleep onset latency (β = -0.314; R2 = 13%; p < 0.001) and rapid eye movement sleep time/total sleep time in % (β = 0.085; R2 = 15%; p = 0.001).

CONCLUSIONS

Pulmonary function variables reflecting severity of airflow and gas exchange impairment, adjusted for some potential confounders, were weakly related to PSG outcomes in COPD patients. The direct contribution of the pathophysiological hallmarks of COPD to objectively measured parameters of sleep quality seems to be less important than it was previously assumed.

Macro- and microvascular reactivity during repetitive exposure to shortened sleep: sex differences

Epidemiological studies have reported strong association between sleep loss and hypertension with unknown mechanisms. This study investigated macrovascular and microcirculation changes and inflammatory markers during repetitive sleep restriction. Sex differences were also explored. Forty-five participants completed a 22-day in-hospital protocol. Participants were assigned to, (1) eight-hour sleep per night (control), or (2) sleep restriction (SR) condition: participants slept from 0300 to 0700 h for three nights followed by a recovery night of 8-h sleep, repeated four times. Macrocirculation assessed by flow mediated dilation (FMD) and microcirculation reactivity tests were performed at baseline, last day of each experimental block and during recovery at the end. Cell adhesion molecules and inflammatory marker levels were measured in blood samples. No duration of deprivation (SR block) by condition interaction effects were found for FMD, microcirculation, norepinephrine, cell adhesion molecules, IL-6 or IL-8. However, when men and women were analyzed separately, there was a statistical trend (p = 0.08) for increased IL-6 across SR blocks in women, but not in men. Interestingly, men showed a significant progressive (dose dependent) increase in skin vasodilatation (p = 0.02). A novel and unexpected finding was that during the recovery period, men that had been exposed to repeated SR blocks had elevated IL-8 and decreased norepinephrine. Macrocirculation, microcirculation, cell adhesion molecules, and markers of inflammation appeared to be resistant to this model of short-term repetitive exposures to the blocks of shortened sleep in healthy sleepers. However, men and women responded differently, with women showing mild inflammatory response and men showing more vascular system sensitivity to the repetitive SR.

Sleep duration regularity, but not sleep duration, is associated with microvascular function in college students

STUDY OBJECTIVES

Vascular dysfunction is a hypothesized mechanism linking poor sleep habits to an increased incidence of cardiovascular diseases (CVDs). However, the vascular profile associated with free-living sleep duration and sleep regularity has not been well elucidated, particularly in young adults. Thus, this study aimed to evaluate the associations between mean sleep duration, regularity in sleep duration, and peripheral vascular function in young adult college students.

METHODS

Fifty-one healthy undergraduate students (20 ± 1 years) completed 14 days of 24-hour wrist actigraphy and subsequent vascular assessments. Macrovascular function was measured using brachial artery flow-mediated dilation (FMD) while microvascular function was measured via passive leg movement (PLM).

RESULTS

Mean sleep duration was unrelated to FMD and PLM. Conversely, more irregular sleep duration (14-day sleep duration standard deviation [SD]) was unfavorably associated with all three measures of PLM-induced hyperemia (peak leg blood flow [LBF], p = 0.01; change in LBF from baseline to peak, p < 0.01; LBF area under the curve, p < 0.01), and remained significant in regression models which adjusted for sex, body mass index, blood pressure, physical activity, alcohol and caffeine consumption, and sleep duration (all p < 0.05). When using a median split to dichotomize "low" and "high" sleep duration SD groups, those demonstrating high variability in sleep duration exhibited ~45% lower PLM responses compared with those demonstrating low variability.

CONCLUSIONS

Irregular sleep duration is associated with poorer microvascular function as early as young adulthood. These findings support the growing body of evidence that irregular sleep patterns may be an independent and modifiable risk factor for CVD.

Actigraphy-Derived Sleep Efficiency Is Associated With Endothelial Function in Men and Women With Untreated Hypertension

BACKGROUND

Poor sleep quality is increasingly recognized as an important and potentially modifiable risk factor for cardiovascular disease (CVD). Impaired endothelial function may be 1 mechanism underlying the association between poor sleep and CVD risk. The present study examined the relationship between objective measures of sleep quality and endothelial function in a sample of untreated hypertensive adults.

METHODS

Participants were 127 men (N = 74) and women (N = 53), including 55 African Americans and 72 White Americans, aged 40-60 years (mean age, 45.3 ± 8.5 years), with untreated hypertension (systolic blood pressure 130-159 mm Hg and/or diastolic blood pressure 85-99 mm Hg). Noninvasive brachial artery flow-mediated dilation (FMD) was assessed by ultrasound. Sleep parameters, including sleep efficiency (SE), total sleep time (TST), and subjective sleep quality, were assessed over 7 consecutive days by wrist actigraphy.

RESULTS

Participants averaged 7.76 ± 1 hours in bed, with an average SE of 78 ± 9%, and TST of 6 ± 1 hours. Brachial FMD averaged 3.5 ± 3.1%. In multivariate analyses controlling for sex, race, body mass index, clinic blood pressure, income, smoking, alcohol use, and baseline arterial diameter, SE was positively associated with FMD (β = 0.28, P = 0.012). Subjective sleep quality (β = -0.04, P = 0.63) and TST (β = -0.11, P = 0.25) were unrelated to FMD.

CONCLUSIONS

Poor sleep as indicated by low SE was associated with impaired FMD. These findings for SE are consistent with previous observations of other measures implicating poor sleep as a CVD risk factor. Interventions that improve sleep may also help lower CVD risk.

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.

Vascular dysfunction and oxidative stress caused by acute formaldehyde exposure in female adults

Formaldehyde (FA) is a common, volatile organic compound used in organic preservation with known health effects of eye, nose, and throat irritation linked to oxidative stress and inflammation. Indeed, long-term FA exposure may provoke skin disorders, cancer, and cardiovascular disease. However, the effects of short-term FA exposure on the vasculature have yet to be investigated. We sought to investigate the impact of an acute FA exposure on 1) macrovascular function in the arm (brachial artery flow-mediated dilation, FMD), 2) microvascular function in the arm (brachial artery reactive hyperemia, RH) and leg (common femoral artery, supine passive limb movement, PLM), and 3) circulating markers of oxidative stress (xanthine oxidase, XO; protein carbonyl, PC; and malondialdehyde, MDA) and inflammation (C-reactive protein, CRP). Ten (n = 10) healthy females (23 ± 1 yr) were studied before and immediately after a 90-min FA exposure [(FA): 197 ± 79 ppb] in cadaver dissection laboratories. Brachial artery FMD% decreased following FA exposure (Pre-FA Exp: 9.41 ± 4.21%, Post-FA Exp: 6.74 ± 2.57%; P = 0.043), and FMD/shear decreased following FA exposure (Pre-FA Exp: 0.13 ± 0.07 AU, Post-FA Exp: 0.07 ± 0.03 AU; P = 0.016). The area under the curve for brachial artery RH (Pre-FA Exp: 481 ± 191 ml, Post-FA Exp: 499 ± 165 ml) and common femoral artery PLM (Pre-FA Exp: 139 ± 95 ml, Post-FA Exp: 129 ± 64 ml) were unchanged by FA exposure (P > 0.05). Circulating MDA increased (Pre-FA Exp: 4.8 ± 1.3 µM, Post-FA Exp: 6.3 ± 2.2 µM; P = 0.047) while XO, PC, and CRP were unchanged by FA exposure (P > 0.05). These initial data suggest a short FA exposure can adversely alter vascular function and oxidative stress, influencing cardiovascular health.NEW & NOTEWORTHY This study was the first to investigate the implications of acute formaldehyde (FA) exposure on adult female vascular function in the arms and legs. The main findings of this study were a decrease in conduit vessel function without any alteration to microvascular function following a 90-min FA exposure. Additionally, the oxidative stress marker malondialdehyde increased after FA exposure. Taken together, these results suggest acute FA exposure have deleterious implications for the vasculature and redox balance.Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/formaldehyde-exposure-decreases-vascular-function/.

Sleep deprivation and endothelial function: reconciling seminal evidence with recent perspectives

Sleep is critical for the maintenance of physiological homeostasis and, as such, inadequate sleep beckons a myriad of pathologies. Sleep deprivation is a growing health concern in contemporary society since short sleep durations are associated with increased cardiovascular disease risk and atherosclerotic plaque development. Vascular endothelial dysfunction is an antecedent to atherosclerosis and cardiovascular disease. Herein, we review seminal literature indicating that short sleep durations attenuate endothelial function and explore more recent evidence indicating that sleep deprivation perturbs autonomic balance and the circadian rhythmicity of peripheral vascular clock components. We further examine literature that indicates a mechanistic link between short sleep duration and endothelial dysfunction and subsequent morbidity. Understanding the mechanisms that regulate endothelial function in the context of sleep deprivation facilitates the development and optimization of interventions, such as exercise, that mitigate the ramifications of inadequate sleep on vascular function and cardiovascular health.Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/sleep-deprivation-and-endothelial-function/.

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.

Association of self-reported sleep duration and quality with BaPWV levels in hypertensive patients

The association between sleep conditions and arterial stiffness remains inconclusive. We aimed to investigate the relationship of sleep duration and quality with brachial-ankle pulse-wave velocity (baPWV) in hypertensive patients. A total of 14,485 hypertensive adults were included in this cross-sectional analysis. Information about sleep duration and quality was obtained via questionnaire. A baPWV level ≥1800 cm/s was defined as indicative of arterial stiffness. Compared with participants with a sleep duration <8 h per day, participants with a sleep duration ≥8 h per day had a significantly higher baPWV level (β = 13.7 cm/s; 95% CI: 3.9, 23.5) and a nonsignificantly higher prevalence of arterial stiffness (39.7% vs. 33.0%; OR, 1.08; 95% CI: 0.99-1.19). Similarly, compared with participants with good or medium sleep quality, participants with poor sleep quality had a significantly higher baPWV level (β = 16.3 cm/s; 95% CI: 0.1, 32.6) and a nonsignificantly greater prevalence of arterial stiffness (36.6% vs. 35.3%; OR, 1.13; 95% CI: 0.97-1.32). When sleep duration and quality were examined jointly, participants with a sleep duration ≥8 h and/or poor sleep quality had a significantly higher baPWV level (β = 14.4 cm/s; 95% CI: 5.3, 23.4) and a greater prevalence of arterial stiffness (38.8% vs. 32.7%; OR, 1.10; 95% CI: 1.01-1.20) than those with a sleep duration <8 h and good/medium sleep quality. In summary, among hypertensive patients, a longer sleep duration (≥8 h per day) and poor sleep quality were associated with higher baPWV levels and a higher prevalence of arterial stiffness.

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.

Specific Dietary (Poly)phenols Are Associated with Sleep Quality in a Cohort of Italian Adults

Background: Diet has been the major focus of attention as a leading risk factor for non-communicable diseases, including mental health disorders. A large body of literature supports the hypothesis that there is a bidirectional association between sleep and diet quality, possibly via the modulation of neuro-inflammation, adult neurogenesis and synaptic and neuronal plasticity. In the present study, the association between dietary total, subclasses of and individual (poly)phenols and sleep quality was explored in a cohort of Italian adults. Methods: The demographic and dietary characteristics of 1936 adults living in southern Italy were analyzed. Food frequency questionnaires (FFQs) were used to assess dietary intake. Data on the (poly)phenol content in foods were retrieved from the Phenol-Explorer database. The Pittsburg Sleep Quality Index was used to measure sleep quality. Multivariate logistic regression analyses were used to test the associations. Results: A significant inverse association between a higher dietary intake of lignans and inadequate sleep quality was found. Additionally, individuals with the highest quartile of hydroxycinnamic acid intake were less likely to have inadequate sleep quality. When individual compounds were taken into consideration, an association with sleep quality was observed for naringenin and apigenin among flavonoids, and for matairesinol among lignans. A secondary analysis was conducted, stratifying the population into normal weight and overweight/obese individuals. The findings in normal weight individuals showed a stronger association between certain classes of, subclasses of and individual compounds and sleep quality. Notably, nearly all individual compounds belonging to the lignan class were inversely associated with inadequate sleep quality. In the overweight/obese individuals, there were no associations between any dietary (poly)phenol class and sleep quality. Conclusions: The results of this study suggest that a higher dietary intake of certain (poly)phenols may be associated with better sleep quality among adult individuals.

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.

Insomnia as an Independent Predictor of Incident Cardiovascular Disease in HIV: Data From the Veterans Aging Cohort Study

BACKGROUND

Insomnia is associated with increased cardiovascular disease (CVD) risk in the general population and is highly prevalent in people with HIV. The CVD risk conferred by insomnia in the HIV population is unknown.

METHODS

Using the Veterans Aging Cohort Study Survey Cohort, insomnia symptoms were measured and dummy coded with the item, "Difficulty falling or staying asleep?" (5-point scale from no difficulty to bothers a lot). Incident CVD event ICD-9 codes (acute myocardial infarction, stroke, or coronary artery revascularization) were identified with the Department of Veterans Affairs (VA) and Medicare administrative data and VA fee-for-service data. Those with baseline CVD were excluded.

RESULTS

HIV-infected (N = 3108) veterans had a median follow-up time of 10.8 years, during which 267 CVD events occurred. Compared to HIV-infected veterans with no difficulty falling or staying asleep, HIV-infected veterans bothered a lot by insomnia symptoms had an increased risk of incident CVD after adjusting for demographics [hazard ratio (HR) = 1.64, 95% confidence interval (CI): 1.16 to 2.31, P = 0.005], CVD risk factors (HR = 1.62, 95% CI: 1.14 to 2.30, P = 0.007), additional potential confounders (hepatitis C infection, renal disease, anemia, alcohol use, and cocaine use; HR = 1.70, 95% CI: 1.19 to 2.43, P = 0.003), and HIV-specific factors (HIV-1 RNA, CD4 T-cell count, and antiretroviral therapy; HR = 1.66, 95% CI: 1.16 to 2.37, P = 0.005). Additional adjustment for nonbenzodiazepine sleep medication (HR = 1.62, 95% CI: 1.13 to 2.32, P = 0.009) did not attenuate the association; however, it fell short of significance at P < 0.01 after adjustment for depressive symptoms (HR = 1.51, 95% CI: 0.98 to 2.32, P = 0.060) or antidepressant medication (HR = 1.51, 95% CI: 1.04 to 2.19, P = 0.031).

CONCLUSIONS

Highly bothersome insomnia symptoms were significantly associated with incident CVD in HIV-infected veterans, suggesting that insomnia may be a novel, modifiable risk factor for CVD in HIV.

Vascular Aging Is Accelerated in Flight Attendants With Occupational Secondhand Smoke Exposure

OBJECTIVE

To determine whether early vascular aging may be present in flight attendants with remote in-cabin secondhand smoke (SHS) exposure.

METHODS

Twenty-six flight attendants with a history of in-cabin SHS exposure prior to the airline smoking bans were recruited. Pulse wave analysis, peripheral arterial tonometry, and brachial artery reactivity testing evaluated their arterial compliance and endothelial function.

RESULTS

Flight attendants with remote in-cabin SHS exposure have normal blood pressure, pulse wave velocity, and reactive hyperemia index, but abnormal pulse pressure, augmentation index, flow-mediated dilation, and hyperemic mean flow ratio.

CONCLUSION

These preliminary findings suggest that flight attendants with remote in-cabin SHS exposure have preclinical signs of accelerated vascular aging and raise new questions about the relationship between remote SHS exposure and vascular health.

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.

Nitrate-Rich Fruit and Vegetable Supplement Reduces Blood Pressure in Normotensive Healthy Young Males without Significantly Altering Flow-Mediated Vasodilation: A Randomized, Double-Blinded, Controlled Trial

Nitric oxide (NO) is a primary vasodilatory factor released from endothelial cells of the peripheral vasculature. NO production is stimulated through enzymatic-dependent mechanisms via NO synthase and from dietary intake of nitrate-containing foods or supplements. We evaluated the efficacy of a nitrate-rich fruit and vegetable liquid supplement (FVS, AMPED NOx, Isagenix International LLC) versus a juice low in nitrates (prune juice, PRU) on circulating nitrates/nitrites as well as cardiovascular parameters in 45 healthy normotensive men (18–40 y). Blood pressure, flow-mediated dilation (FMD), and plasma nitrates and nitrites were measured at baseline and after two weeks of supplementation (2 oz/d). Subjects also completed questionnaires on sleep quality and mood since these measures have been associated with endothelial function. In contrast to PRU, FVS significantly increased plasma nitrates and nitrites (+67%, p < 0.001) and decreased diastolic blood pressure (−9%, p=0.029) after two weeks. The change in FMD for FVS supplementation versus PRU supplementation was not significant (+2% vs. −9%, respectively, p=0.145). Changes in sleep quality or total mood state did not differ between groups after the 2-week study. Thus, the nitrate-rich FVS supplement increased plasma NO and reduced diastolic blood pressure in young normotensive men, but increased plasma NO was not associated with improvements in FMD, mood, or sleep. This trial is registered with ClinicalTrials.gov NCT03486145.

Vascular Response During Mental Stress in Sedentary and Physically Active Patients With Obstructive Sleep Apnea

STUDY OBJECTIVES

To compare vascular function of sedentary (SED) versus physically active (ACTIVE) patients with obstructive sleep apnea (OSA) during rest and mental stress.

METHODS

Patients with untreated OSA without other comorbidities were classified into SED and ACTIVE groups according to the International Physical Activity Questionnaire. Blood pressure (BP), heart rate (HR), forearm blood flow (FBF) (plethysmography), and forearm vascular conductance (FVC = FBF / mean BP × 100) were continuously measured at rest (4 minutes) followed by 3 minutes of mental stress (Stroop Color Word Test).

RESULTS

We studied 40 patients with OSA (men = 24, age = 50 ± 1 years, body mass index = 29.3 ± 0.5 kg/m², apnea-hypopnea index = 39.3 ± 4 events/h). Leisure time physical activity domain in SED (n = 19) and ACTIVE (n = 21) was 20 ± 8 and 239 ± 32 min/wk, (P < .05). Baseline profile and perception of stress were similar in both groups. Baseline FBF (3.5 ± 0.2 mL/min/100 mL versus 2.4 ± 0.14 mL/min/100 mL) and FVC (3.5 ± 0.2 U versus 2.3 ± 0.1 U) were significantly lower in the SED group than in the ACTIVE group, respectively (P < .05). HR and BP increased similarly during mental stress test in both groups. Changes during mental stress in FBF (0.65 ± 0.12 versus 1.04 ± 0.12) and FVC (0.58 ± 0.11 versus 0.99 ± 0.11) were significantly lower in the SED group than in the ACTIVE group, respectively (P < .05). There was a significant correlation between leisure time physical activity and FBF (r = .57, P < .05) and FVC (r = .48, P < .05) during mental stress.

CONCLUSIONS

The vascular response among patients with OSA is influenced by the level of physical activity. A high level of physical activity may partially protect against the cardiovascular dysfunction associated with OSA.

Effects of Inadequate Sleep on Blood Pressure and Endothelial Inflammation in Women: Findings From the American Heart Association Go Red for Women Strategically Focused Research Network

BACKGROUND

Insufficient sleep increases blood pressure. However, the effects of milder, highly prevalent but frequently neglected sleep disturbances, including poor sleep quality and insomnia, on vascular health in women are unclear. We investigated whether poor sleep patterns are associated with blood pressure and endothelial inflammation in a diverse sample of women.

METHODS AND RESULTS

Women who participated in the ongoing American Heart Association Go Red for Women Strategically Focused Research Network were studied (n=323, 57% minority, mean age=39±17 years, range=20-79 years). Sleep duration, sleep quality, and time to sleep onset were assessed using the Pittsburgh Sleep Quality Index (score ≥5=poor sleep quality). Risk for obstructive sleep apnea was evaluated using the Berlin questionnaire, and insomnia was assessed using the Insomnia Severity Index. In a subset of women who participated in the basic study (n=26), sleep duration was assessed objectively using actigraphy, and endothelial inflammation was assessed directly in harvested endothelial cells by measuring nuclear translocation of nuclear factor kappa B. Vascular reactivity was measured by brachial artery flow-mediated dilation (n=26). Systolic and diastolic blood pressure were measured by trained personnel (n=323). Multivariable linear regressions were used to evaluate associations between sleep patterns and blood pressure, nuclear factor kappa B, and flow-mediated dilation. Mean sleep duration was 6.8±1.3 hours/night in the population study and 7.5±1.1 hour/night in the basic study. In the population study sample, 50% had poor sleep quality versus 23% in the basic study, and 37% had some level of insomnia versus 15% in the basic study. Systolic blood pressure was associated directly with poor sleep quality, and diastolic blood pressure was of borderline significance with obstructive sleep apnea risk after adjusting for confounders (P=0.04 and P=0.08, respectively). Poor sleep quality was associated with endothelial nuclear factor kappa B activation (β=30.6; P=0.03). Insomnia and longer sleep onset latency were also associated with endothelial nuclear factor kappa B activation (β=27.6; P=0.002 and β=8.26; P=0.02, respectively). No evidence was found for an association between sleep and flow-mediated dilation.

CONCLUSIONS

These findings provide direct evidence that common but frequently neglected sleep disturbances such as poor sleep quality and insomnia are associated with increased blood pressure and vascular inflammation even in the absence of inadequate sleep duration in women.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02835261.

Insomnia Symptoms Are Associated With Abnormal Endothelial Function

BACKGROUND

Insomnia is a prevalent sleep disorder, and it has been increasingly associated with cardiovascular morbidity and mortality. The reasons for this relationship are not completely understood but may involve endothelial dysfunction. In this study, we hypothesized that insomnia symptoms would be associated with reduced endothelial function.

METHODS

Working adults (n = 496, 67.5% female, 78.6% white, mean age 48.7 [SD, 10.8] years, body mass index 28.2 [SD, 6.7] kg/m, diabetes 5.8%, hypertension 20.0%, hyperlipidemia 17.9%, heart disease 2.6%) enrolled in the Emory-Georgia Tech Predictive Health Institute study completed baseline demographic, clinical, depression (Beck Depression Inventory II), anxiety (General Anxiety Disorder 7), sleep (Pittsburg Sleep Quality Index), and noninvasive endothelial function (brachial artery flow-mediated dilation [FMD]) measures. Insomnia symptoms were defined as subjective sleep latency of 30 minutes or longer, nighttime or early morning awakenings, and/or sleep medication use occurring 3 times or more per week in the past month.

RESULTS

Insomnia symptoms were reported by 39.5% of participants. Multivariable regression models showed that insomnia symptoms, age, baseline artery diameter, and dyslipidemia were inversely related to FMD. After adjusting for age, baseline artery diameter, and dyslipidemia, participants reporting insomnia symptoms had lower FMD than did participants reporting better sleep (adjusted FMD mean, 6.13% [SD, 0.28%] vs 6.83% [SD, 0.26%], P = .035).

CONCLUSION

In this study, insomnia symptoms were associated with reduced FMD. Research examining the therapeutic benefits of treating insomnia on endothelial function and future cardiovascular risk is warranted.

The effect of dim light at night on cerebral hemodynamic oscillations during sleep: A near-infrared spectroscopy study

Recent studies have reported that dim light at night (dLAN) is associated with risks of cardiovascular complications, such as hypertension and carotid atherosclerosis; however, little is known about the underlying mechanism. Here, we evaluated the effect of dLAN on the cerebrovascular system by analyzing cerebral hemodynamic oscillations using near-infrared spectroscopy (NIRS). Fourteen healthy male subjects underwent polysomnography coupled with cerebral NIRS. The data collected during sleep with dim light (10 lux) were compared with those collected during sleep under the control dark conditions for the sleep structure, cerebral hemodynamic oscillations, heart rate variability (HRV), and their electroencephalographic (EEG) power spectrum. Power spectral analysis was applied to oxy-hemoglobin concentrations calculated from the NIRS signal. Spectral densities over endothelial very-low-frequency oscillations (VLFOs) (0.003-0.02 Hz), neurogenic VLFOs (0.02-0.04 Hz), myogenic low-frequency oscillations (LFOs) (0.04-0.15 Hz), and total LFOs (0.003-0.15 Hz) were obtained for each sleep stage. The polysomnographic data revealed an increase in the N2 stage under the dLAN conditions. The spectral analysis of cerebral hemodynamics showed that the total LFOs increased significantly during slow-wave sleep (SWS) and decreased during rapid eye movement (REM) sleep. Specifically, endothelial (median of normalized value, 0.46 vs. 0.72, p = 0.019) and neurogenic (median, 0.58 vs. 0.84, p = 0.019) VLFOs were enhanced during SWS, whereas endothelial VLFOs (median, 1.93 vs. 1.47, p = 0.030) were attenuated during REM sleep. HRV analysis exhibited altered spectral densities during SWS induced by dLAN, including an increase in very-low-frequency and decreases in low-frequency and high-frequency ranges. In the EEG power spectral analysis, no significant difference was detected between the control and dLAN conditions. In conclusion, dLAN can disturb cerebral hemodynamics via the endothelial and autonomic systems without cortical involvement, predominantly during SWS, which might represent an underlying mechanism of the increased cerebrovascular risk associated with light exposure during sleep.

Regular consumption of HolisFiit, a polyphenol-rich extract-based food supplement, improves mind and body well-being of overweight and slightly obese volunteers: a randomized, double-blind, parallel trial

Modern lifestyles face growing demands for natural solutions to help improve general well-being. Accordingly, mind-body activities such as yoga have considerably grown. However, beneficial effects require regular workout. Besides, literature suggests that polyphenols may demonstrate positive effects on both mental and physical health. Overweight and obese volunteers, for which well-being might be perceived degraded, were included in a 16-week double-blind, randomized and parallel trial with a daily supplementation of HolisFiit^®, a polyphenol-rich food supplement. Body composition was assessed by dual-energy X-ray absorptiometry (DXA) technology; well-being was evaluated with both, Athens Insomnia Scale (AIS) and components from Short Form-36 questionnaire (SF-36). Body composition significantly rebalanced by 7.7% (p = .019) of the lean-to-fat mass ratio. Also, sleep quality significantly improved by 43% (p = .00015) as well as both physical and mental components from SF-36, respectively by 10% (p = .004) and 7% (p = .021). These data altogether, suggest that regular consumption of HolisFiit^®, might significantly improve mind and body well-being.

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.

An update on cardiovascular effects of obstructive sleep apnoea syndrome

Obstructive sleep apnoea syndrome is an important health problem which may cause or worsen systemic diseases. Chronic intermittent hypoxia during repetitive airflow cessations may cause endothelial dysfunction. Sleep apnoea is also shown to be associated with hypercoagulability which may be due to decreased nitric oxide levels and impaired vasodilatation. Endothelial dysfunction, increased systemic inflammation, sympathetic nervous system activation, increased oxidative stress and dysglycaemia may all contribute to cardiovascular processes such as hypertension, arrhythmia, stroke, heart failure and coronary artery disease in patients with obstructive sleep apnoea. Treatment approaches in patients with obstructive sleep apnoea mainly focus on maintaining upper airway patency either with positive airway pressure devices or upper airway appliances. Strategies involving positive airway pressure therapy are associated with decreased morbidity and mortality. Obstructive sleep apnoea should be suspected as an underlying mechanism in patients with cardiovascular disease and warrants appropriate treatment.

Associations between vasodilatory capacity, physical activity and sleep among younger and older adults

INTRODUCTION

Exercise promotes cardiovascular health through its direct impact on the vascular endothelium. Conversely, poor sleep quality is associated with endothelial dysfunction, which may explain the increased cardiovascular disease amongst poor sleepers. Yet, the influence of physical activity and poor sleep quality on vascular health is not clear.

PURPOSE

This study examined the relationships between forearm vasodilatory capacity, self-reported sleep quality and free-living, actigraphy-derived energy expenditure in a group of young and older community dwelling adults.

METHODS

Venous occlusion plethysmography determined baseline and peak forearm blood flow following reactive hyperemia. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Measures of body composition were assessed using dual energy X-ray absorptiometry.

RESULTS

A total of 104 (61 young; 43 old) participants completed the study. In general, younger participants were more active, as determined by steps per day and average daily energy expenditure, but reported poorer sleep quality. In the combined sample, those who reported moderate sleep disturbances (PSQI total score; 11-15) had significantly lower vasodilatory capacity (16.8 ± 7.6 ml/100 ml/min) compared to those who reported no sleep disturbance (PSQI total score; 0-5) (22.3 ± 7.2 ml/100 ml/min) or mild sleep disturbance (PSQI total score; 6-10) (22.3 ± 8.1 ml/100 ml/min) (p < 0.01). After adjustment for physical activity, total body fat and age, moderately poor sleep remained an independent predictor of forearm vasodilatory capacity.

CONCLUSIONS

These findings suggest that any positive vascular benefits accrued through increased physical activity might be offset by the negative consequences of chronically disturbed sleep.

Nighttime aircraft noise impairs endothelial function and increases blood pressure in patients with or at high risk for coronary artery disease

Aims

Epidemiological studies suggest the existence of a relationship between aircraft noise exposure and increased risk for myocardial infarction and stroke. Patients with established coronary artery disease and endothelial dysfunction are known to have more future cardiovascular events. We therefore tested the effects of nocturnal aircraft noise on endothelial function in patients with or at high risk for coronary artery disease.

Methods

60 Patients (50p 1–3 vessels disease; 10p with a high Framingham Score of 23 %) were exposed in random and blinded order to aircraft noise and no noise conditions. Noise was simulated in the patients’ bedroom and consisted of 60 events during one night. Polygraphy was recorded during study nights, endothelial function (flow-mediated dilation of the brachial artery), questionnaires and blood sampling were performed on the morning after each study night.

Results

The mean sound pressure levels L_eq(3) measured were 46.9 ± 2.0 dB(A) in the Noise 60 nights and 39.2 ± 3.1 dB(A) in the control nights. Subjective sleep quality was markedly reduced by noise from 5.8 ± 2.0 to 3.7 ± 2.2 (p < 0.001). FMD was significantly reduced (from 9.6 ± 4.3 to 7.9 ± 3.7 %; p < 0.001) and systolic blood pressure was increased (from 129.5 ± 16.5 to 133.6 ± 17.9 mmHg; p = 0.030) by noise. The adverse vascular effects of noise were independent from sleep quality and self-reported noise sensitivity.

Conclusions

Nighttime aircraft noise markedly impairs endothelial function in patients with or at risk for cardiovascular disease. These vascular effects appear to be independent from annoyance and attitude towards noise and may explain in part the cardiovascular side effects of nighttime aircraft noise.

Long sleep duration associated with a higher risk of increased arterial stiffness in males

STUDY OBJECTIVES

We aimed to examine the association between sleep duration and arterial stiffness among adults of different ages, because to date there has been only one study on this relationship, which was confined to middle-aged civil servants.

DESIGN

Cross-sectional study.

SETTING

A health examination center in National Cheng Kung University Hospital, Taiwan.

PARTICIPANTS

A total of 3,508 subjects, age 20-87 y, were enrolled after excluding those with a history of cerebrovascular events, coronary artery disease, peripheral artery disease, and taking lipid-lowering drugs, antihypertensives, hypoglycemic agents, and anti-inflammatory drugs, from October 2006 to August 2009.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

SLEEP DURATION WAS CLASSIFIED INTO THREE GROUPS: short (< 6 h), normal (6-8 h) and long (> 8 h). Arterial stiffness was measured by brachial-ankle pulse-wave velocity (baPWV), and increased arterial stiffness was defined as baPWV ≥ 1400 cm/sec. The sleep duration was different for subjects with and without increased arterial stiffness in males, but not in females. In the multivariate analysis for males, long sleepers (odds ratio [OR] 1.75, P = 0.034) but not short sleepers (OR 0.98, P = 0.92) had a higher risk of increased arterial stiffness. In addition, age, estimated glomerular filtration rate, hypertension, diabetes, total cholesterol/high-density lipoprotein cholesterol ratio, cigarette smoking, and exercise were also independently associated factors. However, in females, neither short nor long sleep duration was associated with increased arterial stiffness.

CONCLUSIONS

Long sleep duration was associated with a higher risk of increased arterial stiffness in males. Short sleepers did not exhibit a significant risk of increased arterial stiffness in either sex.

CITATION

Tsai TC, Wu JS, Yang YC, Huang YH, Lu FH, Chang CJ. Long sleep duration associated with a higher risk of increased arterial stiffness in males. SLEEP 2014;37(8):1315-1320.