A case-control study on the effect of rhythmic masticatory muscle activity (RMMA) clusters on sleep fragmentation and severity of orofacial muscle pain in sleep bruxism

Rhythmic masticatory muscle activity (RMMA) is a periodic muscle activity that characterises sleep bruxism (SB) events. These can occur as a single event, in pairs, or in clusters. Since RMMA episodes often occur in clusters and the relevance of this occurrence is unknown, we conducted a study to investigate the effect of RMMA clusters on sleep fragmentation and the severity of orofacial muscle pain. This study involved a secondary analysis using data from 184 adult subjects with orofacial muscle pain who underwent definitive polysomnography (PSG) for sleep bruxism diagnosis. Self-reported orofacial muscle pain (OFMP) was assessed using the numeric rating scale, and additional evaluation of side-to-side equivalence (symmetry) was described using a binary system. Among the 184 participants, 60.8% (n = 112) did not exhibit clusters and among the 72 participants with clusters, 36.1% (n = 26) and 63.9% (n = 46) were in the high and low RMMA frequency groups, respectively. The high SB group had significantly three times more phasic RMMA events than the noncluster group. A total of 89.67% (n = 165) of subjects reported orofacial muscle pain. While there was no difference in the severity of OFMP among groups, a significant decrease in symmetry between the severity of temporal muscle pain on the left and right sides was noted in the cluster group compared with the noncluster group. Clustering of RMMA events is associated with sleep fragmentation. The asymmetry of temporal muscle pain is related to the presence of RMMA clusters in sleep bruxism.

Association between daytime napping and incident arrhythmias: A prospective cohort study and mendelian randomization analysis

BACKGROUND

Emerging evidence has linked daytime napping with the risk of cardiovascular events. Cardiac arrhythmias are considered an early clinical stage for cardiovascular diseases. However, whether napping frequency is associated with incident arrhythmias remains unknown.

OBJECTIVE

This study aimed to prospectively investigate the association between napping frequency and cardiac arrhythmias.

METHODS

Daytime napping frequency was self-reported in response to touchscreen questionnaires. The primary outcomes were incident arrhythmias including atrial fibrillation/flutter (AF/Af), ventricular arrhythmia, and bradyarrhythmia. Cox regression analysis was conducted on the basis of 491,117 participants free of cardiac arrhythmias from the UK Biobank. The 2-sample mendelian randomization (MR) and 1-sample MR were used to ensure a causal effect of genetically predicted daytime napping on the risk of arrhythmias.

RESULTS

During a median follow-up of 11.91 years, 28,801 incident AF/Af cases, 4132 incident ventricular arrhythmias, and 11,616 incident bradyarrhythmias were documented. Compared with never/rarely napping, usually napping was significantly associated with higher risks of AF/Af (hazard ratio, 1.141; 95% CI, 1.083-1.203) and bradyarrhythmia (hazard ratio, 1.138; 95% CI, 1.049-1.235) but not ventricular arrhythmia after adjustment for various covariates. The 2-sample MR and 1-sample MR analysis showed that increased daytime napping frequency was likely to be a potential causal risk factor for AF/Af in FinnGen (odds ratio, 1.626; 95% CI, 1.061-2.943) and bradyarrhythmia in the UK Biobank (odds ratio, 1.005; 95% CI, 1.002-1.008).

CONCLUSION

The results of this study add to the burgeoning evidence of an association between daytime napping frequency and an increased risk of cardiac arrhythmias including AF/Af, ventricular arrhythmia, and bradyarrhythmia.

Association of obstructive sleep apnea with risk of lung cancer: a nationwide cohort study in Korea

Current knowledge regarding the relationship between obstructive sleep apnea (OSA) and the risk of lung cancer is limited. This study aimed to evaluate associations between OSA and the incidence of lung cancer based on the Korean National Health Information Database. The study outcome was the incidence of newly diagnosed lung cancer, and a Cox proportional hazards model was used for analysis. A total of 181,070 adult patients newly diagnosed with OSA between 2011 and 2018 were matched with those without OSA by up to 1:5 propensity score matching based on age and sex. During follow-up over (mean ± standard deviation) 9.1 ± 2.0 years, 2614 incident cases of lung cancer were identified. The incidence rate was 39.51 per 100,000 person-years in the OSA group, and 24.93 per 100,000 person-years in the control group. After adjusting for income and the presence of comorbidities, the association remained significant (hazard ratio [HR] 1.95, 95% confidence interval [CI] 1.74-2.18, p-value < 0.001). The adjusted HR for incident lung cancer was 2.14 (95% CI 1.69-2.70) in female patients with OSA, and 1.90 (95% CI 1.67-2.16) in male patients with OSA. The risk of incident lung cancer increased with age, with a HR of 2.99 (95% CI 2.46-3.64) in those aged ≥ 65 years. This nationwide study showed an independent association between OSA and an increased risk of lung cancer in the Korean population.

Sleep deprivation reduces the baroreflex sensitivity through elevated angiotensin (Ang) II subtype 1 receptor expression in the nucleus tractus solitarii

Introduction

Sleep insufficiency has been linked to an increased risk of high blood pressure and cardiovascular diseases. Emerging studies have demonstrated that impaired baroreflex sensitivity (BRS) is involved in the adverse cardiovascular effects caused by sleep deprivation, however, the underlying mechanisms remain unknown. Therefore, the present study aims to clarify the role of abnormal renin-angiotensin system in the nucleus tractus solitarii (NTS) in impaired BRS induced by sleep deprivation.

Methods

Rats were randomly divided into two groups: normal sleep (Ctrl) and chronic sleep deprivation (CSD) group. Rats were sleep deprived by an automated sleep deprivation system. The blood pressure, heart rate, BRS, the number of c-Fos positive cells and the expression of angiotensin (Ang) II subtype 1 receptors (AT1R) in the NTS of rats were assessed.

Results

Compared to Ctrl group, CSD group exhibited a higher blood pressure, heart rate, and reduced BRS. Moreover, the number of c-Fos positive cells and local field potential in the NTS in CSD group were increased compared with the Ctrl group. It was shown that the expression of the AT1R and the content of Ang II and the ratio of Ang II to Ang-(1-7) were increased in the NTS of rats in CSD group compared to Ctrl group. In addition, microinjection of losartan into the NTS significantly improved the impaired BRS caused by sleep deprivation.

Discussion

In conclusion, these data suggest that the elevated AT1R expression in the NTS mediates the reduced BRS induced by chronic sleep deprivation.

Objective sleep characteristics and hypertension: a community-based cohort study

Objective

The link between sleep quality and hypertension risk is well-established. However, research on the specific dose-relationship between objective sleep characteristics and hypertension incidence remains limited. This study aims to explore the dose-relationship association between objective sleep characteristics and hypertension incidence.

Methods

A community-based prospective cohort study design was employed using data from the Sleep Heart Health Study (SHHS). A total of 2,460 individuals were included in the study, of which 780 had hypertension. Baseline personal characteristics and medical history were collected. Objective sleep characteristics were obtained through polysomnography (PSG). Multivariate logistic regression models were utilized for analysis. Restricted cubic splines (RCS) were used to examine dose-relationship associations.

Results

After adjusting for covariates, the percentage of total sleep duration in stage 2 (N2%) was positively associated with hypertension incidence, while the N3% was negatively associated with hypertension incidence Odds ratio (OR) = 1.009, 95% confidence interval (CI) [1.001, 1.018], P = 0.037; OR = 0.987, 95% CI: [0.979, 0.995], P = 0.028, respectively. For every 10% increase in N2 sleep, the risk of developing hypertension increases by 9%, while a 3% decrease in N3 sleep corresponds to a 0.1% increase in the incidence of hypertension. In the subgroup of non-depression, a positive association between N2% and hypertension was significant statistically (OR = 1.012, 95%CI, 1.002, 1.021, P = 0.013, Pinteraction = 0.013). RCS demonstrated that the risk of developing hypertension was lower when N2% ranged from 38% to 58% and rapidly increased thereafter (P = 0.002, non-linear P = 0.040). The lowest risk for hypertension incidence risk of N3% occurring at 25%, and a significant increase below 15% or above 40% (P = 0.001, non-linear P = 0.008).

Conclusions

There's a negative association between N3% and the incidence of hypertension, and a positive association between N2% and the incidence of hypertension, particularly among non-depression individuals. These associations exhibit strong non-linear dose-response relationships.

Association of Periodic Limb Movements and Obstructive Sleep Apnea With Risk of Cardiovascular Disease and Mortality

BACKGROUND

Obstructive sleep apnea is a well-established risk factor for cardiovascular disease (CVD). Recent studies have also linked periodic limb movements during sleep to CVD. We aimed to determine whether periodic limb movements during sleep and obstructive sleep apnea are independent or synergistic factors for CVD events or death.

METHODS AND RESULTS

We examined data from 1049 US veterans with an apnea-hypopnea index (AHI) <30 events/hour. The primary outcome was incident CVD or death. Cox proportional hazards regression assessed the relationships between the AHI, periodic limb movement index (PLMI), and the AHI×PLMI interaction with the primary outcome. We then examined whether AHI and PLMI were associated with primary outcome after adjustment for age, sex, race and ethnicity, obesity, baseline risk of mortality, and Charlson Comorbidity Index. During a median follow-up of 5.1 years, 237 of 1049 participants developed incident CVD or died. Unadjusted analyses showed an increased risk of the primary outcome with every 10-event/hour increase in PLMI (hazard ratio [HR], 1.08 [95% CI, 1.05-1.13]) and AHI (HR, 1.17 [95% CI, 1.01- 1.37]). Assessment associations of AHI and PLMI and their interaction with the primary outcome revealed no significant interaction between PLMI and AHI. In fully adjusted analyses, PLMI, but not AHI, was associated with an increased risk of primary outcome: HR of 1.05 (95% CI, 1.00-1.09) per every 10 events/hour. Results were similar after adjusting with Framingham risk score.

CONCLUSIONS

Our study revealed periodic limb movements during sleep as a risk factor for incident CVD or death among those who had AHI <30 events/hour, without synergistic association between periodic limb movements during sleep and obstructive sleep apnea.

Collagen peptide supplementation before bedtime reduces sleep fragmentation and improves cognitive function in physically active males with sleep complaints

PURPOSE

The primary aim of this study was to examine whether a glycine-rich collagen peptides (CP) supplement could enhance sleep quality in physically active men with self-reported sleep complaints.

METHODS

In a randomized, crossover design, 13 athletic males (age: 24 ± 4 years; training volume; 7 ± 3 h·wk1) with sleep complaints (Athens Insomnia Scale, 9 ± 2) consumed CP (15 g·day1) or a placebo control (CON) 1 h before bedtime for 7 nights. Sleep quality was measured with subjective sleep diaries and actigraphy for 7 nights; polysomnographic sleep and core temperature were recorded on night 7. Cognition, inflammation, and endocrine function were measured on night 7 and the following morning. Subjective sleepiness and fatigue were measured on all 7 nights. The intervention trials were separated by ≥ 7 days and preceded by a 7-night familiarisation trial.

RESULTS

Polysomnography showed less awakenings with CP than CON (21.3 ± 9.7 vs. 29.3 ± 13.8 counts, respectively; P = 0.028). The 7-day average for subjective awakenings were less with CP vs. CON (1.3 ± 1.5 vs. 1.9 ± 0.6 counts, respectively; P = 0.023). The proportion of correct responses on the baseline Stroop cognitive test were higher with CP than CON (1.00 ± 0.00 vs. 0.97 ± 0.05 AU, respectively; P = 0.009) the morning after night 7. There were no trial differences in core temperature, endocrine function, inflammation, subjective sleepiness, fatigue and sleep quality, or other measures of cognitive function or sleep (P > 0.05).

CONCLUSION

CP supplementation did not influence sleep quantity, latency, or efficiency, but reduced awakenings and improved cognitive function in physically active males with sleep complaints.

Preceding Night Sleep Quality and Atrial Fibrillation Episodes in the I-STOP-AFIB Randomized Trial

BACKGROUND

Chronic sleep disruption is associated with incident atrial fibrillation (AF), but it is unclear whether poor sleep quality acutely triggers AF.

OBJECTIVES

The aim of this study was to characterize the relationship between a given night's sleep quality and the risk of a discrete AF episode.

METHODS

Patients with symptomatic paroxysmal AF in the I-STOP-AFIB (Individualized Studies of Triggers of Paroxysmal Atrial Fibrillation) trial reported sleep quality on a daily basis. Participants were also queried daily regarding AF episodes and were provided smartphone-based mobile electrocardiograms (ECGs) (KardiaMobile, AliveCor).

RESULTS

Using 15,755 days of data from 419 patients, worse sleep quality on any given night was associated with a 15% greater odds of a self-reported AF episode the next day (OR: 1.15; 95% CI: 1.10-1.20; P < 0.0001) after adjustment for the day of the week. No statistically significant associations between worsening sleep quality and mobile ECG-confirmed AF events were observed (OR: 1.04; 95% CI: 0.95-1.13; P = 0.43), although substantially fewer of these mobile ECG-confirmed events may have limited statistical power. Poor sleep was also associated with longer self-reported AF episodes, with each progressive category of worsening sleep associated with 16 (95% CI: 12-21; P < 0.001) more minutes of AF the next day.

CONCLUSIONS

Poor sleep was associated with an immediately heightened risk for self-reported AF episodes, and a dose-response relationship existed such that progressively worse sleep was associated with longer episodes of AF the next day. These data suggest that sleep quality may be a potentially modifiable trigger relevant to the near-term risk of a discrete AF episode.

The 24-h activity cycle and cardiovascular outcomes: establishing biological plausibility using arterial stiffness as an intermediate outcome

This review proposes a biologically plausible working model for the relationship between the 24-h activity cycle (24-HAC) and cardiovascular disease. The 24-HAC encompasses moderate-to-vigorous physical activity (MVPA), light physical activity, sedentary behavior (SB), and sleep. MVPA confers the greatest relative cardioprotective effect, when considering MVPA represents just 2% of the day if physical activity guidelines (30 min/day) are met. While we have well-established guidelines for MVPA, those for the remaining activity behaviors are vague. The vague guidelines are attributable to our limited mechanistic understanding of the independent and additive effects of these behaviors on the cardiovascular system. Our proposed biological model places arterial stiffness, a measure of vascular aging, as the key intermediate outcome. Starting with prolonged exposure to SB or static standing, we propose that the reported transient increases in arterial stiffness are driven by a cascade of negative hemodynamic effects following venous pooling. The subsequent autonomic, metabolic, and hormonal changes further impair vascular function. Vascular dysfunction can be offset by using mechanistic-informed interruption strategies and by engaging in protective behaviors throughout the day. Physical activity, especially MVPA, can confer protection by chronically improving endothelial function and associated protective mechanisms. Conversely, poor sleep, especially in duration and quality, negatively affects hormonal, metabolic, autonomic, and hemodynamic variables that can confound the physiological responses to next-day activity behaviors. Our hope is that the proposed biologically plausible working model will assist in furthering our understanding of the effects of these complex, interrelated activity behaviors on the cardiovascular system.

Deep learning-based sleep stage classification with cardiorespiratory and body movement activities in individuals with suspected sleep disorders

Deep learning methods have gained significant attention in sleep science. This study aimed to assess the performance of a deep learning-based sleep stage classification model constructed using fewer physiological parameters derived from cardiorespiratory and body movement data. Overnight polysomnography (PSG) data from 123 participants (age: 19-82 years) with suspected sleep disorders were analyzed. Multivariate time series data, including heart rate, respiratory rate, cardiorespiratory coupling, and body movement frequency, were input into a bidirectional long short-term memory (biLSTM) network model to train and predict five-class sleep stages. The trained model's performance was evaluated using balanced accuracy, Cohen's κ coefficient, and F1 scores on an epoch-per-epoch basis and compared with the ground truth using the leave-one-out cross-validation scheme. The model achieved an accuracy of 71.2 ± 5.8%, Cohen's κ of 0.425 ± 0.115, and an F1 score of 0.650 ± 0.083 across all sleep stages, and all metrics were negatively correlated with the apnea-hypopnea index, as well as age, but positively correlated with sleep efficiency. Moreover, the model performance varied for each sleep stage, with the highest F1 score observed for N2 and the lowest for N3. Regression and Bland-Altman analyses between sleep parameters of interest derived from deep learning and PSG showed substantial correlations (r = 0.33-0.60) with low bias. The findings demonstrate the efficacy of the biLSTM deep learning model in accurately classifying sleep stages and in estimating sleep parameters for sleep structure analysis using a reduced set of physiological parameters. The current model without using EEG information may expand the application of unobtrusive in-home monitoring to clinically assess the prevalence of sleep disorders outside of a sleep laboratory.

Obstructive sleep apnoea and glaucoma: a systematic review and meta-analysis

INTRODUCTION

Obstructive sleep apnoea (OSA) has been thought to be associated with glaucoma, however there are many conflicting studies on this topic. With many new studies having been published since the previous meta-analysis, we believe it is important to clarify this association. Hence, in this study we meta-analyse the recent literature regarding the association between OSA and glaucoma.

METHODS

Pubmed, Embase, Scopus and Cochrane Library were searched from inception till the 28th February 2022 for observational as well as cross-sectional studies examining the association between OSA and glaucoma. Two reviewers selected studies, extracted data, graded the quality of included non-randomized studies using the Newcastle-Ottawa scale. The overall quality of evidence was assessed using GRADE. Random-effects models were used to meta-analyse the maximally covariate- adjusted associations.

RESULTS

48 studies were included in our systematic review, with 46 suitable for meta-analysis. Total study population was 4,566,984 patients. OSA was associated with a higher risk of glaucoma (OR 3.66, 95% CI 1.70 to 7.90, I2 = 98%, p < 0.01). After adjustment for various important confounders including age, gender and patient comorbidities such as hyperlipidaemia, hypertension, cardiovascular diseases and diabetes, patients with OSA had up to 40% higher odds of glaucoma. Substantial heterogeneity was eliminated through subgroup and sensitivity analyses after consideration of glaucoma subtype, OSA severity and adjustment for confounders.

CONCLUSIONS

In this meta-analysis, OSA was associated with higher risk of glaucoma, as well as more severe ocular findings characteristic of the glaucomatous disease process. We suggest more clinical studies looking into the effects of OSA treatment on the progression of glaucoma to help clinical decision making for patients.

Incidence disparities of obstructive sleep apnea-associated lung cancer by gender; Korean National Health Insurance data analysis

Introduction

Obstructive sleep apnea (OSA) is known to increase the risk of various cancers. By analyzing the Korea National Health Insurance Service (KNHIS) registry, the impact of OSA on the lung cancer incidence was analyzed in a retrospective cohort group.

Methods

A retrospective cohort of adult patients newly registered with OSA in the KNHIS data from 2007 to 2017 was included and observed until December 2019 (12 years). The main outcome measure was newly diagnosed lung cancer. The control group was set with age and sex that matched those in the OSA group.

Results

The hazard ratio (HR) of OSA for lung cancer incidence showed a significantly reduced HR of 0.87 (95% CI, 0.82-0.93). The observed significance of this finding was limited to male OSA patients [HR, 0.84 (95% CI, 0.78-0.90)], while no significant association was found in female OSA patients [HR, 1.05 (95% CI, 0.91-1.21)], irrespective of their age.

Discussion

OSA patients have a lower risk of developing lung cancer, but this risk reduction is gender-specific, as female OSA patients do not show a reduction in hazard ratio.

Durative sleep fragmentation with or without hypertension suppress rapid eye movement sleep and generate cerebrovascular dysfunction

Either hypertension or chronic insomnia is the risk factor of developing vascular dementia. Durative hypertension can induce vascular remodeling and is used for modeling small vessel disease in rodents. It remains undetermined if the combination of hypertension and sleep disturbance exacerbates vascular dysfunction or pathologies. Previously, we found chronic sleep fragmentation (SF) dampened cognition in young mice without disease predispositions. In the current study, we superimposed SF with hypertension modeling in young mice. Angiotensin II (AngII)-releasing osmotic mini pumps were subcutaneously implanted to generate persistent hypertension, while sham surgeries were performed as controls. Sleep fragmentation with repetitive arousals (10 s every 2 min) during light-on 12 h for consecutive 30 days, while mice undergoing normal sleep (NS) processes were set as controls. Sleep architectures, whisker-stimulated cerebral blood flow (CBF) changes, vascular responsiveness as well as vascular pathologies were compared among normal sleep plus sham (NS + sham), SF plus sham (SF + sham), normal sleep plus AngII (NS + AngII), and SF plus AngII (SF + AngII) groups. SF and hypertension both alter sleep structures, particularly suppressing REM sleep. SF no matter if combined with hypertension strongly suppressed whisker-stimulated CBF increase, suggesting the tight association with cognitive decline. Hypertension modeling sensitizes vascular responsiveness toward a vasoactive agent, Acetylcholine (ACh, 5 mg/ml, 10 μl) delivered via cisterna magna infusion, while SF exhibits a similar but much milder effect. None of the modeling above was sufficient to induce arterial or arteriole vascular remodeling, but SF or SF plus hypertension increased vascular network density constructed by all categories of cerebral vessels. The current study would potentially help understand the pathogenesis of vascular dementia, and the interconnection between sleep and vascular health.

Self-reported insomnia symptoms, sleep duration, chronotype and the risk of acute myocardial infarction (AMI): a prospective study in the UK Biobank and the HUNT Study

Insomnia and short/long sleep duration increase the risk of AMI, but their interaction with each other or with chronotype is not well known. We investigated the prospective joint associations of any two of these sleep traits on risk of AMI. We included 302 456 and 31 091 participants without past AMI episodes from UK Biobank (UKBB; 2006–10) and the Trøndelag Health Study (HUNT2; 1995–97), respectively. A total of 6 833 and 2 540 incident AMIs were identified during an average 11.7 and 21.0 years follow-up, in UKBB and HUNT2, respectively. Compared to those who reported normal sleep duration (7–8 h) without insomnia symptoms, the Cox proportional hazard ratios (HRs) for incident AMI in UKBB among participants who reported normal, short and long sleep duration with insomnia symptoms were 1.07 (95% CI 0.99, 1.15), 1.16 (95% CI 1.07, 1.25) and 1.40 (95% CI 1.21, 1.63), respectively. The corresponding HRs in HUNT2 were 1.09 (95% CI 0.95, 1.25), 1.17 (95% CI 0.87, 1.58) and 1.02 (95% CI 0.85, 1.23). The HRs for incident AMI in UKBB among evening chronotypes were 1.19 (95% CI 1.10, 1.29) for those who had insomnia symptoms, 1.18 (95% CI 1.08, 1.29) for those with short sleep duration, and 1.21 (95% CI 1.07, 1.37) for those with long sleep duration, compared to morning chronotypes without another sleep symptom. The relative excess risk for incident AMI in UKBB due to interaction between insomnia symptoms and long sleep duration was 0.25 (95% CI 0.01, 0.48). Insomnia symptoms with long sleep duration may contribute more than just an additive effect of these sleep traits on the risk of AMI.

Neuroimaging Studies of the Neural Correlates of Heart Rate Variability: A Systematic Review

Direct and indirect links between brain regions and cardiac function have been reported. We performed a systematic literature review to summarize current knowledge regarding the associations of heart rate variability (HRV) and brain region morphology, activity and connectivity involved in autonomic control at rest in healthy subjects. Both positive and negative correlations of cortical thickness and gray matter volumes of brain structures with HRV were observed. The strongest were found for a cluster located within the cingulate cortex. A decline in HRV, as well as cortical thickness with increasing age, especially in the orbitofrontal cortex were noted. When associations of region-specific brain activity with HRV were examined, HRV correlated most strongly with activity in the insula, cingulate cortex, frontal and prefrontal cortices, hippocampus, thalamus, striatum and amygdala. Furthermore, significant correlations, largely positive, between HRV and brain region connectivity (in the amygdala, cingulate cortex and prefrontal cortex) were observed. Notably, right-sided neural structures may be preferentially involved in heart rate and HRV control. However, the evidence for left hemispheric control of cardiac vagal function has also been reported. Our findings provide support for the premise that the brain and the heart are interconnected by both structural and functional networks and indicate complex multi-level interactions. Further studies of brain-heart associations promise to yield insights into their relationship to health and disease.

Sleep characteristics associated with nocturnal blood pressure nondipping in healthy individuals: a systematic review

OBJECTIVE

The current literature investigating nocturnal blood pressure (BP) nondipping has largely focused on clinical populations, however, conditions such as hypertension, obstructive sleep apnoea and insomnia are recognized confounding factors for BP dipping. The exact mechanisms responsible for BP nondipping remain unclear, therefore, there is a need to investigate BP nondipping in healthy individuals to better understand the underlying mechanisms. This review identifies sleep characteristics that may contribute to BP nondipping in healthy individuals. It is anticipated that an understanding of the sleep characteristics that contribute to BP nondipping may inform future sleep-related behavioral interventions to ultimately reducing the burden of cardiovascular disease.

METHODS

The PubMed, Scopus and Web of Science databases were searched for relevant, English language, peer-reviewed publications (from inception to March 2022). The search identified 550 studies. After duplicates were removed, the titles and abstracts of the remaining 306 studies were screened. Of these, 250 studies were excluded leaving 56 studies to test for eligibility. Thirty-nine studies were excluded such that 17 studies fully met the inclusion criteria for the review.

RESULTS

Findings from this review indicate that short sleep duration, more sleep fragmentation, less sleep depth and increased variability in sleep timing may be associated with BP nondipping in healthy individuals.

CONCLUSION

While there is no evidence-based approach for the treatment of nocturnal BP nondipping, it seems promising that addressing one's sleep health may be an important starting point to reduce the prevalence of BP nondipping and perhaps the progression to cardiovascular disease.

Association of Sleep Duration and Cardio-Ankle Vascular Index in Community-Dwelling Older Adults

AIM

This study aims to investigate the association of the Cardio-Ankle Vascular Index (CAVI) with self-reported sleep duration and sleep quality in community-dwelling older adults aged ≥ 65 years.

METHODS

The Tarumizu Study was a cohort of community-based health checkups conducted in the Tarumizu City, Japan, in 2018 and 2019. In total, 997 participants aged ≥ 65 years (median age, 74 years) were examined. We obtained the average sleep duration and sleep quality using self-reported questionnaires and classified them into three separate groups according to sleep duration (＜6 h, 6-8 h, and ≥ 8 h) and sleep quality (good, medium, and poor). The arterial stiffness was measured using the CAVI.

RESULTS

As per our findings, the CAVI was significantly higher in the ≥ 8 h sleep group (CAVI=9.6±1.3) than in the ＜6 h (CAVI=9.1±1.1) or 6-8 h (CAVI=9.1±1.2) groups (p＜0.001). After adjustment for age, sex, systolic blood pressure, current smoking status, body mass index, frequency of exercise, educational background, frailty, sleep medication, sleep quality, and nap duration, multivariable regression analysis demonstrated that the CAVI was significantly higher in the ≥ 8 h group than in the 6-8 h group (p=0.016). In contrast, multivariable regression analysis showed that there was no significant association between sleep quality and CAVI.

CONCLUSIONS

A significant association was noted between long sleep duration (≥ 8 h) and elevated CAVI in community-dwelling older adults aged ≥ 65 years. We, therefore, suggest that long sleep duration, not sleep quality, is correlated with arterial stiffness in older adults.

Effect of Cognitive-Behavioral Therapy on Nocturnal Autonomic Activity in Patients with Fibromyalgia: A Preliminary Study

Objective: fibromyalgia is a complex chronic pain syndrome characterized by widespread musculoskeletal pain, insomnia and autonomic alterations. Cognitive-behavioral therapy (CBT) is regarded as a promising treatment in fibromyalgia, but its impact on autonomic function remains uncertain. In this research, we studied the effect of CBT on autonomic functions in fibromyalgia. Methods: Twenty-five participants underwent overnight polysomnographic recordings before and after CBT programs focused on pain (CBT-P) or a hybrid modality focused on pain and insomnia (CBT-C). Sleep quality, daily pain, depression and anxiety were assessed by self-reported questionnaires. We analyzed heart rate variability (HRV) using high-frequency power (HF) as a marker for parasympathetic activity, and low-frequency power (LF) and the LF/HF ratio as relative sympathetic markers during wakefulness and at each sleep stage. Results: After treatment, 14 patients (/25, 58.0%) reported improvement in their sleep: 6 in the CBT-P condition (/12, 50%), and 8 in the CBT-C condition (/13, 61.5%). We found that, regardless of the type of CBT, patients who reported improvement in sleep quality (n = 14, 58%) had an increase in HF during stages N2 (p < 0.05) and N3 (p < 0.05). These changes were related to improvement in sleep quality (N2, r = −0.43, p = 0.033) but not to pain, depression or anxiety. Conclusions: This study showed an improvement in parasympathetic cardiac control during non-rapid-eye-movement sleep following CBT in fibromyalgia participants who reported better sleep after this therapy. CBT may have a cardio-protective effect and HRV could be used as a sleep monitoring tool in fibromyalgia.

Association between obstructive sleep apnea and cardiovascular diseases

Obstructive sleep apnea (OSA) is a common respiratory disorder characterized by partial obstruction of upper respiratory tract and repetitive cessation of breathing during sleep. The etiology behind OSA is associated with the occurrence of intermittent hypoxemia, recurrent arousals and intrathoracic pressure swings. These contributing factors may turn on various signaling mechanisms including elevated sympathetic tone, oxidative stress, inflammation, endothelial dysfunction, cardiovascular variability, abnormal coagulation and metabolic defect ( e.g., insulin resistance, leptin resistance and altered hepatic metabolism). Given its close tie with major cardiovascular risk factors, OSA is commonly linked to the pathogenesis of a wide array of cardiovascular diseases (CVDs) including hypertension, heart failure, arrhythmias, coronary artery disease, stroke, cerebrovascular disease and pulmonary hypertension (PH). The current standard treatment for OSA using adequate nasal continuous positive airway pressure (CPAP) confers a significant reduction in cardiovascular morbidity. Nonetheless, despite the availability of effective therapy, patients with CVDs are still deemed highly vulnerable to OSA and related adverse clinical outcomes. A better understanding of the etiology of OSA along with early diagnosis should be essential for this undertreated disorder in the clinical setting.

Physiological markers of sleep quality: A scoping review

Understanding the associations between adequate sleep, performance and health outcomes is vital, yet a major limitation in the design and interpretation of studies of sleep and performance is the variability of subjective and objective markers used to assess sleep quality. The aim of this scoping review is to investigate how various physiological signals recorded during sleep or wakefulness relate to objective measures of cognitive or physical performance and subjectively perceived sleep quality to inform conceptual understanding of the elusive, amorphous, and multi-dimensional construct of sleep quality. We also aimed to suggest priorities for future areas of research in sleep quality and performance. We searched six databases ultimately yielding 439 studies after duplicate removal. Sixty-five studies were selected for full review. In general, correlations between objectively measured sleep and objective performance or subjectively assessed sleep quality were weak to moderate. Slow wave sleep was moderately correlated with better performance on tasks of vigilance, motor speed, and executive function as well as better subjective sleep quality and feeling well-rested, suggesting that slow wave sleep may be important for sleep quality and optimal daytime performance. However, these findings were inconsistent across studies. Increased sleep fragmentation was associated with poorer subjective sleep quality in both polysomnographic and actigraphic studies. Studies which simultaneously assessed physiologic sleep measures, performance measures and subjective sleep perception were few, limiting the ability to evaluate correlations between subjective and objective outcomes concurrently in the same individuals. Factors influencing the relationship between sleep quality and performance include circadian variability, sleep inertia, and mismatch between sleep stages studied and outcome measures of choice. Ultimately, the determination of "quality sleep" remains largely subjective and inconsistently quantifiable by current measures. Methods evaluating sleep as a continuous measure rather than traditional sleep stages may provide an intriguing approach to future studies of sleep and performance. Future well-designed studies using novel measures of sleep or multimodal ambulatory wearables assessing the three domains of sleep and performance (objective sleep physiology, objective performance, and subjective sleep quality) are needed to better define quality sleep.

Obstructive Sleep Apnea and Hypertension: Updates to a Critical Relationship

Purpose of Review

Obstructive sleep apnea (OSA) is an underdiagnosed illness linked to essential hypertension (HTN), resistant hypertension (r-HTN), and cardiovascular disease (CVD). This review provides updates on the epidemiology, pathophysiology, and treatments of OSA-associated HTN.

Recent Findings

Mild sleep apnea increases the risk for HTN. Eighty-nine percent of young patients aged 18–35 with HTN not attributed to secondary causes have underlying OSA. Home sleep studies are noninferior to formal polysomnography for OSA diagnosis. Nocturnal oxygen desaturation rate is positively correlated with HTN severity. Gut microbiome neo-colonization in response to high-fat diet cravings in patients with OSA alters immune function and worsens HTN. Carbonic anhydrase inhibitors and probiotics show newfound potential for OSA-associated HTN treatment. OSA recognition improves hospital outcomes after a STEMI. Hypoxia-inducible factor (HIF) transcription increases in a dose-dependent manner to hypoxia, and HIFs are strongly linked to cancer growth.

Summary

OSA and HTN are comorbid conditions with adversely connected pathophysiology including sympathetic hyperactivity, gut dysbiosis, proinflammation, endothelial damage, rostral fluid shifts, pharyngeal collapse, intravascular fluid retention, nocturnal energy expenditure, and metabolic derangements. The dose–response effect of OSA on HTN severity challenges blood pressure (BP) control, so those with refractory HTN should be screened for OSA.

Relationships Between Cardinal Features of Obstructive Sleep Apnea and Blood Pressure: A Retrospective Study

BACKGROUND

Obstructive sleep apnea (OSA) is associated with hypertension; however, the associations between cardinal features of OSA, such as intermittent hypoxia (IH) and sleep fragmentation (SF), and blood pressure remain unclear. We performed this study to address this issue.

METHOD

We investigated 335 subjects with the polysomnography (PSG) tests. Data, including basic characteristics, PSG parameters, and blood pressure, were collected. We calculated p-values for linear trends of blood pressure across oxygen-desaturation index (ODI)/microarousal index (MAI) quartiles. Logistic regressions were used to determine the risk factors for abnormal blood pressure and to detect the multiplicative interaction between ODI and MAI with blood pressure.

RESULTS

After adjusting for multiple variables, compared with subjects with lower ODI quartiles, those with higher ODI quartiles had significant higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) (p for trend = 0.010 and 0.018, respectively). And compared with subjects with lower ODI quartiles, those with higher ODI quartiles were also more likely to have abnormal DBP and hypertension after adjusting for multiple variables. Similarly, compared with subjects with lower MAI quartiles, those with higher MAI quartiles had significant higher SBP and DBP, and were more likely to have abnormal DBP and hypertension. No significant multiplicative interactions between ODI and MAI with blood pressure were detected.

CONCLUSION

Subjects with more severe IH/SF had significant higher blood pressure and were more likely to have abnormal DBP and hypertension than those with less severe IH/SF. No interaction between IH and SF on the relationship with blood pressure was shown.

Gender Differences in the Context of Obstructive Sleep Apnea and Metabolic Diseases

The relationship between obstructive sleep apnea (OSA) and endocrine and metabolic disease is unequivocal. OSA, which is characterized by intermittent hypoxia and sleep fragmentation, leads to and exacerbates obesity, metabolic syndrome, and type 2 diabetes (T2D) as well as endocrine disturbances, such as hypothyroidism and Cushing syndrome, among others. However, this relationship is bidirectional with endocrine and metabolic diseases being considered major risk factors for the development of OSA. For example, polycystic ovary syndrome (PCOS), one of the most common endocrine disorders in women of reproductive age, is significantly associated with OSA in adult patients. Several factors have been postulated to contribute to or be critical in the genesis of dysmetabolic states in OSA including the increase in sympathetic activation, the deregulation of the hypothalamus-pituitary axis, the generation of reactive oxygen species (ROS), insulin resistance, alteration in adipokines levels, and inflammation of the adipose tissue. However, probably the alterations in the hypothalamus-pituitary axis and the altered secretion of hormones from the peripheral endocrine glands could play a major role in the gender differences in the link between OSA-dysmetabolism. In fact, normal sleep is also different between men and women due to the physiologic differences between genders, with sex hormones such as progesterone, androgens, and estrogens, being also connected with breathing pathologies. Moreover, it is very well known that OSA is more prevalent among men than women, however the prevalence in women increases after menopause. At the same time, the step-rise in obesity and its comorbidities goes along with mounting evidence of clinically important sex and gender differences. Metabolic and cardiovascular diseases, seen as a men's illness for decades, presently are more common in women than in men and obesity has a higher association with insulin-resistance-related risk factors in women than in men. In this way, in the present manuscript, we will review the major findings on the overall mechanisms that connect OSA and dysmetabolism giving special attention to the specific regulation of this relationship in each gender. We will also detail the gender-specific effects of hormone replacement therapies on metabolic control and sleep apnea.

Association Between Arousals During Sleep and Hypertension Among Patients With Obstructive Sleep Apnea

Background

Sleep fragmentation induced by repetitive arousals is a hallmark of obstructive sleep apnea (OSA). Sleep fragmentation has been linked to hypertension in community‐based studies, but it is unclear if this association is manifest in OSA. We aimed to explore whether frequent arousals from sleep modify the relationship between OSA and prevalent hypertension.

Methods and Results

A total of 10 102 patients with OSA and 1614 primary snorers were included in the study. Hypertension was defined on either direct blood pressure measures or diagnosis by a physician. Spontaneous, respiratory, and movement arousals were derived by polysomnography. Logistic regression models were used to estimate the associations between arousals and prevalent hypertension in patients with OSA and primary snorers. For every 10‐unit increase of total arousal index, odds of hypertension significantly increased in both the total sample (odds ratio [OR], 1.08; 95% CI, 1.03–1.14; P=0.002) and patients with OSA (OR, 1.10; 95% CI, 1.04–1.16; P<0.001), but not in the primary snoring group. Total arousal index was significantly associated with systolic blood pressure and diastolic blood pressure in the total sample (β=0.05 and β=0.06; P<0.001) and in patients with (β=0.05 and β=0.06; P<0.01), but not in primary snorers. In addition, a greater influence of respiratory events with arousals than respiratory events without arousals on blood pressure in OSA was also noted. Results were independent of confounders, including apnea‐hypopnea index and nocturnal hypoxemia.

Conclusions

We conclude that repetitive arousals from sleep are independently associated with prevalent hypertension in patients with OSA.

Sympathetic Neural Control in Humans with Anxiety-Related Disorders

Numerous conceptual models are used to describe the dynamic responsiveness of physiological systems to environmental pressures, originating with Claude Bernard's milieu intérieur and extending to more recent models such as allostasis. The impact of stress and anxiety upon these regulatory processes has both basic science and clinical relevance, extending from the pioneering work of Hans Selye who advanced the concept that stress can significantly impact physiological health and function. Of particular interest within the current article, anxiety is independently associated with cardiovascular risk, yet mechanisms underlying these associations remain equivocal. This link between anxiety and cardiovascular risk is relevant given the high prevalence of anxiety in the general population, as well as its early age of onset. Chronically anxious populations, such as those with anxiety disorders (i.e., generalized anxiety disorder, panic disorder, specific phobias, etc.) offer a human model that interrogates the deleterious effects that chronic stress and allostatic load can have on the nervous system and cardiovascular function. Further, while many of these disorders do not appear to exhibit baseline alterations in sympathetic neural activity, reactivity to mental stress offers insights into applicable, real-world scenarios in which heightened sympathetic reactivity may predispose those individuals to elevated cardiovascular risk. This article also assesses behavioral and lifestyle modifications that have been shown to concurrently improve anxiety symptoms, as well as sympathetic control. Lastly, future directions of research will be discussed, with a focus on better integration of psychological factors within physiological studies examining anxiety and neural cardiovascular health. © 2022 American Physiological Society. Compr Physiol 12:1-33, 2022.

Associations of Insomnia With Hypertension and Coronary Artery Disease Among Patients With Type 2 Diabetes Mellitus

Purpose: This study aimed to determine whether insomnia is associated with hypertension (HBP) and coronary artery disease (CAD) in a hospital-based sample of patients with type 2 diabetes mellitus (T2DM).

Methods: Our present study included 354 patients with T2DM. According to the diagnostic criteria of insomnia, the participants were assigned to three groups based on the duration of T2DM and insomnia diagnosis. Patients with T2DM alone were placed in group A; patients with T2DM longer than insomnia were placed in group B; and patients with insomnia longer than T2DM were placed in group C. Medical history was collected from all the patients in detail. Besides, the participants underwent thorough physical examinations and laboratory measurements. Propensity score matching (PSM) was applied to evaluate the associations of insomnia with HBP and CAD. The univariate and multivariate logistic regression analysis was used to explore whether insomnia was a risk factor for HBP and CAD in patients with T2DM.

Results: Of 354 patients, 225 patients were included in group A, 62 patients were included in group B, and 67 patients were included in group C. Compared with groups B and C, group A showed a lower prevalence of HBP and CAD (p < 0.05). In addition, compared with group B, group C showed no difference in the prevalence of HBP and CAD (p > 0.05). After PSM was performed, groups B and C had a higher prevalence of HBP and CAD (p < 0.05) than group A with no significant difference between groups B and C (p > 0.05). In the univariate and multivariate logistic regression analysis, insomnia was a risk factor for HBP [univariate: odds ratio (OR) = 3.376, 95% CI 2.290–6.093, p < 0.001; multivariate: OR = 2.832, 95% CI 1.373–5.841, p = 0.005] and CAD (univariate: OR = 5.019, 95% CI 3.148–8.001, p < 0.001; multivariate: OR = 5.289, 95% CI 2.579–10.850, p < 0.001).

Conclusion: T2DM combined with insomnia was related to HBP and CAD and insomnia was a risk factor for HBP and CAD in patients with T2DM. However, larger, prospective studies are required to confirm our findings.

Obstructive Sleep Apnea and Lung Cancer: A Systematic Review and Meta-analysis of 4,885,518 Participants

RATIONALE

In 2020, lung cancer was the leading cause of cancer deaths, and was the most common cancer in men. Though obstructive sleep apnea (OSA) has been postulated to be carcinogenic, epidemiological studies are inconclusive.

OBJECTIVES

We conducted this systematic review and meta-analysis to investigate the associations between OSA and the incidence and mortality of lung cancer.

METHODS

Four electronic databases (PubMed, Embase, Cochrane Library, and Scopus) were searched from inception till 6 June 2021 for randomized controlled trials and observational studies examining the association between sleep apnea and incident lung cancer. Two reviewers selected studies, extracted data, graded the risk of bias using the Newcastle-Ottawa scale and the quality of evidence using GRADE. Random-effects models were used to meta-analyze the maximally covariate-adjusted associations.

RESULTS

Seven studies were included in our systematic review; among which four were suitable for meta-analysis, comprising a combined cohort of 4,885,518 patients. Risk of bias was low to moderate. OSA was associated with a higher incidence of lung cancer (HR 1.25, 95%CI 1.02 to 1.53), with substantial heterogeneity (I²=97%). Heterogeneity was eliminated, with a stable pooled effect size, when including the three studies with at least 5 years of median follow-up (HR 1.32, 95%CI 1.27 to 1.37, I²=0%).

CONCLUSIONS

In this meta-analysis of 4,885,518 patients from four observational studies, patients with OSA had approximately 30% higher risk of lung cancer, compared to those without OSA. We suggest more clinical studies with longer follow-up as well as biological models of lung cancer be performed to further elucidate this relationship.

Risk factors associated with uncontrolled blood pressure among patients with non-dialysis chronic kidney disease in Vietnam

Background

Uncontrolled blood pressure rates are high in patients with non-dialysis chronic kidney disease, worsening the disease progression and leading to end-stage renal disease. However, studies on uncontrolled blood pressure in patients with non-dialysis chronic kidney disease and its associated factors in Vietnam are scarce.Objectives: This study aimed at identifying uncontrolled blood pressure rates and risk factors associated with uncontrolled blood pressure among Vietnamese patients with non-dialysis chronic kidney disease.

Methods

A cross-sectional, correlational study design was employed among 182 participants coming to follow up at two tertiary hospitals in Vietnam. The participants were selected by a convenience sampling technique. Data were collected using Participant Demographic Information Form, Clinical Characteristics Form, Alcohol Use Disorders Identification Test, Pittsburgh Sleep Quality Index, Charlson Comorbidity Index, and an automated office oscillometric upper arm device. Descriptive statistics, Chi-square, Fisher's Exact Test, and binary logistic regression were used to analyze the data.

Results

63.2% of the participants could not control their BP less than 130/80 mmHg. Poor sleep quality (OR 2.076, 95%CI 1.059-4.073, p=.034) and severe comorbidities (OR 2.926, 95%CI 1.248-6.858, p=.013) were risk factors associated with uncontrolled blood pressure among Vietnamese patients with non-dialysis chronic kidney disease. Interestingly, the study found a high rate of awareness toward the importance of blood pressure control but a low rate of known blood pressure targets.

Conclusion

Uncontrolled blood pressure rates among Vietnamese patients with non-dialysis chronic kidney disease were high. Sleep quality and comorbidity severity were significantly associated with uncontrolled blood pressure in this population. To achieve blood pressure targets, nurses and other healthcare providers should pay more attention to the patients with poor sleep quality and severe comorbidities.

Evaluation of sleep quality among nursing faculty: Application of the Pittsburgh Sleep Quality Index-A descriptive correlational study

AIM

The aim of this study was to describe the overall sleep quality, sleep patterns and severity of sleep difficulties among nursing faculty using the Pittsburgh Sleep Quality Index (PSQI).

DESIGN

Cross-sectional descriptive and correlational study.

METHODS

A survey of faculty recruited from Texas Board of Nursing approved colleges/schools was used. A purposive, convenience sample of 105 faculty completed the PSQI, a reliable and valid instrument, in an online setting. Data was collected from January 2019 through April 2019.

RESULTS

Nursing faculty reported sleep difficulty across all components, with more problems in sleep latency, sleep disturbances and subjective sleep quality. Overall, 70.5% of participants were reportedly "poor" sleepers, a salient finding. Faculty experienced poor sleep quality across all academic ranks and age groups. Sleep latency and subjective sleep quality were components that presented higher in severity for the youngest faculty.

The age and gender effect on the association of sleep insufficiency with hypertension among adults in Greece

Background: We aimed to investigate the relationship between sleep characteristics with hypertension using self-reported questionnaires. Material & methods: A total of 957 adults were classified into three groups (short [<6 h], normal [6-8 h] and long [>8 h] sleepers). Hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg or use of antihypertensive medication at the time of interview. Results: Overall prevalence of hypertension was 34.3%. Association between short sleep duration and hypertension that was age-specific, present only among younger and middle aged individuals and sparing the elderly, but not gender-specific, as no discrepancies existed between males and females in all age groups, was evident. Conclusion: This study promotes early pharmacological or cognitive behavioral interventions on sleep disturbances in order to reduce hypertension burden.

Superior hypertension control with betablockade in the European Sleep Apnea Database

AIMS

Arterial hypertension is highly prevalent and difficult to control in patients with obstructive sleep apnea (OSA). High sympathoadrenergic activity is a hallmark physiological phenomenon in OSA. We hypothesized that an antihypertensive drug with inhibitory properties on this activity, such as beta blockers (BBs), may be particularly efficacious in OSA patients.

METHODS

Hypertensive OSA patients receiving blood pressure-lowing treatment in the European Sleep Apnea Database (ESADA) (n = 5818, 69% men, age 58 ± 11 years, body mass index 33 ± 7 kg/m2, apnea hypopnea index 34 ± 26 events/h) were analyzed. Reported medications [BB, diuretic, renin-angiotensin blocker (RAB), calcium channel blocker (CCB), and centrally acting antihypertensive (CAH)] were classified according to ATC code. Office blood pressure was compared in patients with monotherapy or combination therapy controlling for confounders.

RESULTS

Poorly controlled SBP according to the ESC/ESH guidelines was found in 66% of patients. Patients receiving monotherapy with RAB, CCB or CAH had 2.2 (95% CI 1.4-3.0), 3.0 (1.9-4.1) and 3.0 (1.7-4.7) mmHg higher SBP compared with those on BB (adjusted model, P = 0.007, 0.008 and 0.017, respectively). In those with a combination of two antihypertensive drugs, SBP was 5.5 (4.0-7.1), 5.1 (3.7-6.6), 4.3 (2.5-6.1) and 3.1 (1.6-4.6) mmHg higher in those on CCB/RAB, BB/RAB, BB/CCB or diuretic/RAB compared with those on BB/diuretic (adjusted model, P < 0.001, <0.001, 0.018 and 0.036, respectively).

CONCLUSION

Poorly controlled blood pressure was common in OSA patients with antihypertensive medication. Treatment with BB alone or BB in combination with a diuretic was associated with the lowest systolic pressure in this large clinical cohort.

Sleeping Difficulty and Subjective Short Sleep Duration are Associated with Serum N-terminal Pro-brain Natriuretic Peptide Levels in the Elderly Population

Objective It is well known that poor sleep increases the risk of heart failure (HF). However, the underlying mechanisms remain unclear. In this study, we investigated the association of poor sleep with hemodynamic stress on the left ventricle, which was a key factor for the development of HF in elderly individuals. Methods A total of 2,301 participants (≥65 years old) without cardiac disease were enrolled in this cross-sectional analysis. We evaluated the subjective sleep quality, sleeping difficulty, subjective sleep duration, use of sleeping pills, and daytime dysfunction using the Pittsburgh Sleep Quality Index, a 19-item self-reported questionnaire. We assessed serum N-terminal pro-brain natriuretic peptide (NT-proBNP) as a marker of hemodynamic stress on the left ventricle, and we defined high NT-proBNP as a serum NT-proBNP level ≥ 125 pg/mL. Results Sleeping difficulty was significantly associated with high NT-proBNP levels [odds ratio (OR), 1.46; 95% confidence interval (CI), 1.16-1.85; p<0.005]. A subjective short sleep duration was also significantly associated with high NT-proBNP levels (OR, 1.69; 95% CI, 1.03-2.75; p<0.05). A subjective poor sleep quality, the use of sleeping pills, and daytime dysfunction were not associated with serum NT-proBNP levels. All data were adjusted for the age, sex, body mass index, serum hemoglobin concentration, serum creatinine level, systolic blood pressure, diastolic blood pressure, and use of antihypertensive medications. Conclusion Poor sleep was associated with high hemodynamic stress to the left ventricle in elderly population.

Lower serum sodium levels predict poor clinical outcomes in patients with insomnia

Background

The association between lower serum sodium levels and the clinical outcomes of insomnia patients remains unclear. We explored whether lower serum sodium is associated with poor clinical outcomes in patients with insomnia.

Methods

We retrospectively enrolled patients with a diagnosis of insomnia from January 2011 to December 2012. We divided participants into three groups according to initial serum sodium level: tertile 1 (< 138 mmol/L), tertile 2 (138.0–140.9 mmol/L), and tertile 3 (≥ 141.0 mmol/L). To calculate the relative risk of death, hazard ratios (HRs) and 95% confidence intervals (CIs) were obtained using Cox proportional hazard models.

Results

A total of 412 patients with insomnia were included, of whom 13.6% (n = 56) had hyponatremia. Patients with lower serum sodium concentrations were older and had lower hemoglobin, calcium, phosphorus, and albumin levels. At the median follow-up of 49.4 months, 44 patients had died and 62 experienced acute kidney injury (AKI). Kaplan-Meier analysis showed significantly higher mortality in patients in the lowest tertile for serum sodium. The lowest tertile of the serum sodium level and the AKI were associated with all-cause mortality. However, the lowest tertile of the serum sodium level was not significantly associated with AKI.

Conclusions

The lowest tertile of the serum sodium level was associated with a higher mortality rate in insomnia patients. Our results suggest that the serum sodium level could serve as a prognostic factor in insomniacs; patients with lower sodium levels require particular care.

A multidisciplinary weight loss intervention in obese adolescents with and without sleep-disordered breathing improves cardiometabolic health, whether SDB was normalized or not

OBJECTIVES

Pediatric obesity and sleep-disordered breathing (SDB) are strongly associated, and both promote metabolic impairments. However, the effects of a lifestyle intervention on the overall metabolic syndrome (MetS) are unknown. The objectives were i) to evaluate the effects of a lifestyle intervention on cardiometabolic risk (CMR), assessed with a dichotomous (MetS) and a continuous (MetScore_FM) instrument, in obese adolescents with and without SDB and ii) to compare the post-intervention cardiometabolic responses between adolescents with persistent (apnea-hypopnea index; AHI≥2) or normalized-SDB (AHI<2).

METHODS

Seventy-six adolescents with obesity recruited from two specialized institutions underwent a 9-12month diet and exercise intervention. Sleep and SDB (AHI≥2) were studied by polysomnography. Anthropometric parameters, fat mass (FM), glucose, insulin, lipid and leptin profiles, blood pressure (BP), MetScore_FM and MetS were assessed pre- and post-intervention. We performed comparisons between Non-SDB and SDB groups and between Normalized-SDB and Persistent-SDB subgroups.

RESULTS

Fifty participants completed the study. Pre-intervention, twenty youth had SDB (40%) with higher insulin concentrations and systolic BP than Non-SDB participants (p < 0.01), for a similar degree of obesity. Post-intervention, MetScore_FM (p < 0.001) and MetS prevalence (p < 0.05) were decreased in both groups. Eleven participants (55%) normalized SDB along with a decrease in insulin concentrations and BP (p < 0.05). Triglycerides, total cholesterol and LDL-cholesterol concentrations (p < 0.01) improved equally in the Normalized and Persistent-SDB subgroups.

CONCLUSION

SDB was associated with lower insulin sensitivity and higher BP but did not affect the lipid profile. A diet and exercise lifestyle intervention is effective in decreasing the CMR whether or not SDB was normalized in obese adolescents.

Understanding the pathophysiological mechanisms of cardiometabolic complications in obstructive sleep apnoea: towards personalised treatment approaches

In January 2019, a European Respiratory Society research seminar entitled "Targeting the detrimental effects of sleep disturbances and disorders" was held in Dublin, Ireland. It provided the opportunity to critically review the current evidence of pathophysiological responses of sleep disturbances, such as sleep deprivation, sleep fragmentation or circadian misalignment and of abnormalities in physiological gases such as oxygen and carbon dioxide, which occur frequently in respiratory conditions during sleep. A specific emphasis of the seminar was placed on the evaluation of the current state of knowledge of the pathophysiology of cardiovascular and metabolic diseases in obstructive sleep apnoea (OSA). Identification of the detailed mechanisms of these processes is of major importance to the field and this seminar offered an ideal platform to exchange knowledge, and to discuss pitfalls of current models and the design of future collaborative studies. In addition, we debated the limitations of current treatment strategies for cardiometabolic complications in OSA and discussed potentially valuable alternative approaches.

Increased sympathetic responses induced by chronic obstructive sleep apnea are caused by sleep fragmentation

Obstructive sleep apnea (OSA) is often associated with sympathetic overactivity and hypertension. These associations are mainly attributed to hypoxia acting on arterial chemoreceptors. However, the contribution of arousal from sleep is unclear. We measured the effect of OSA and sleep fragmentation on cardiovascular and sympathetic function and gene expression in the brain in rats. Male Wistar rats were fitted with a tracheal balloon and EEG and electromyogram electrodes and assigned to control (n = 6), OSA (n = 9), or arousal (n = 8) treatments. The OSA group was subjected to obstructive apnea, each time the rat entered sleep, for 8 h/day for 15 days. The arousal group was similarly exposed to vibration, which was produced with a miniature vibration motor mounted on the rat's head. Vibration intensity slowly increased until the rat awoke. One day after the last apnea or arousal, rats were anesthetized and arterial blood pressure and splanchnic sympathetic nerve activity (SSNA) were recorded. Baseline mean and diastolic pressure were increased after OSA. Resting SSNA was similar in the three groups, but both OSA and sleep fragmentation increased sympathetic activation in response to airway obstruction and chemoreflex activation by cyanide. OSA increased superoxide dismutases 1 and 2 in the brainstem, whereas sleep fragmentation did not. Our results suggest that sympathetic overactivity to chemoreceptor stimulation was a consequence of arousal from sleep. Our study suggests that sleep disruption may have an important role in the development of apnea-related sympathetic activation.NEW & NOTEWORTHY Obstructive sleep apnea causes a hyperactive chemoreflex, with increased sympathetic activation. However, it is not clear whether this pathophysiologic mechanism is due to repeated hypoxia or to sleep disruption. The present study suggests that sleep fragmentation contributes importantly to increased sympathetic activation after chemoreceptor stimulation. This suggests that sleep fragmentation has an important role in the sympathetic activation seen in sleep apnea patients.

Broken sleep predicts hardened blood vessels

Why does poor-quality sleep lead to atherosclerosis? In a diverse sample of over 1,600 individuals, we describe a pathway wherein sleep fragmentation raises inflammatory-related white blood cell counts (neutrophils and monocytes), thereby increasing atherosclerosis severity, even when other common risk factors have been accounted for. Improving sleep quality may thus represent one preventive strategy for lowering inflammatory status and thus atherosclerosis risk, reinforcing public health policies focused on sleep health.

Why does poor quality sleep correlate with cardiovascular disease? A large population-based study suggests that fragmented sleep contributes to atherosclerosis in humans by increasing inflammatory-related activity of white blood cells.

Associations Between Objective Sleep and Ambulatory Blood Pressure in a Community Sample

OBJECTIVE

Epidemiologic data increasingly support sleep as a determinant of cardiovascular disease risk. Fewer studies have investigated the mechanisms underlying this relationship using objective sleep assessment approaches. Therefore, the aim of this study was to examine associations between daily blood pressure (BP) and both objectively assessed sleep duration and efficiency.

METHODS

A diverse community sample of 300 men and women aged 21 to 70 years, enrolled in the North Texas Heart Study, participated in the study. Actigraphy-assessed sleep was monitored for two consecutive nights with ambulatory BP sampled randomly within 45-minute blocks on the first and second day as well as the second night.

RESULTS

Overall, sleep duration results paralleled those of sleep efficiency. Individuals with lower sleep efficiency had higher daytime systolic (B = -0.35, SE = 0.11, p = .0018, R = 0.26) but not diastolic BP (B = -0.043, SE = 0.068, p = .52, R = 0.17) and higher nighttime BP (systolic: B = -0.37, SE = 0.10, p < .001, R = .15; diastolic: B = -0.20, SE = 0.059, p < .001, R = .14). Moreover, lower sleep efficiency on one night was associated with higher systolic (B = -0.51, SE = 0.11, p < .001, R = 0.23) and diastolic BP (B = -0.17, SE = 0.065, p = .012, R = .16) the following day. When 'asleep' BP was taken into account instead of nighttime BP, the associations between sleep and BP disappeared. When both sleep duration and efficiency were assessed together, sleep efficiency was associated with daytime systolic BP, whereas sleep duration was associated with nighttime BP.

CONCLUSIONS

Lower sleep duration and efficiency are associated with higher daytime systolic BP and higher nighttime BP when assessed separately. When assessed together, sleep duration and efficiency diverge in their associations with BP at different times of day. These results warrant further investigation of these possible pathways to disease.

Sleep-disordered breathing in adolescents with obesity: When does it start to affect cardiometabolic health?

BACKGROUND AND AIMS

Pediatric obesity and sleep-disordered breathing (SDB) are associated with cardiometabolic risk (CMR), but the degree of severity at which SDB affects cardiometabolic health is unknown. We assessed the relationship between the CMR and the apnea-hypopnea index (AHI), to identify a threshold of AHI from which an increase in the CMR is observed, in adolescents with obesity. We also compared the clinical, cardiometabolic and sleep characteristics between adolescents presenting a high (CMR+) and low CMR (CMR-), according to the threshold of AHI.

METHODS AND RESULTS

114 adolescents with obesity were recruited from three institutions specialized in obesity management. Sleep and SDB as assessed by polysomnography, anthropometric parameters, fat mass (FM), glucose and lipid profiles, and blood pressure (BP) were measured at admission. Continuous (MetScore_FM) and dichotomous (metabolic syndrome, MetS) CMR were determined. Associations between MetScore_FM and AHI adjusted for BMI, sex and age were assessed by multivariable analyses. Data of 82 adolescents were analyzed. Multivariable analyses enabled us to identify a threshold of AHI = 2 above which we observed a strong and significant association between CMR and AHI (Cohen's d effect-size = 0.57 [0.11; 1.02] p = 0.02). Adolescents with CMR+ exhibited higher MetScore_FM (p < 0.05), insulin resistance (p < 0.05), systolic BP (p < 0.001), sleep fragmentation (p < 0.01) and intermittent hypoxia than CMR- group (p < 0.0001). MetS was found in 90.9% of adolescents with CMR+, versus 69.4% in the CMR- group (p < 0.05).

CONCLUSIONS

The identification of a threshold of AHI ≥ 2 corresponding to the cardiometabolic alterations highlights the need for the early management of SDB and obesity in adolescents, to prevent cardiometabolic diseases.

CLINICAL TRIALS

NCT03466359, NCT02588469 and NCT01358773.

Effect of Glucose Improvement on Nocturnal Sleep Breathing Parameters in Patients with Type 2 Diabetes: The Candy Dreams Study

Type 2 diabetes exerts a negative impact on sleep breathing. It is unknown whether a long-term improvement in glycemic control ameliorates this effect. We conducted an interventional study with 35 patients with type 2 diabetes and obstructive sleep apnea (OSA) to explore this. At home, sleep breathing parameters were assessed at baseline and after a 4-month period in which antidiabetic therapy was intensified. Patients who decreased their body mass index ≥2kg/m² were excluded. Those with an HbA1c reduction ≥0.5% were considered good responders (n = 24). After the follow-up, good responders exhibited an improvement in the apnea–hypopnea index (AHI: 26-1 (95% IC: 8.6–95.0) vs. 20.0 (4.0–62.4) events/hour, p = 0.002) and in time with oxygen saturation below 90% (CT90: 13.3 (0.4–69.0) vs. 8.1 (0.4–71.2) %, p = 0.002). No changes were observed in the group of non–responders (p = 0.722 and p = 0.138, respectively). The percentage of moderate and severe OSA decreased among good responders (p = 0.040). In the wider population, the change in HbA1c correlated positively to decreases in AHI (r = 0.358, p = 0.035) and negatively to increases in the minimum arterial oxygen saturation (r = −0.386, p = 0.039). Stepwise multivariate regression analysis showed that baseline AHI and the absolute change in HbA1c independently predicted decreased AHI (R² = 0.496). The improvement of glycemic control exerts beneficial effects on sleep breathing parameters in type 2 diabetes, which cannot be attributed merely to weight loss.

Effects of Sleep Duration on Cardiovascular Events

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Are obstructive sleep apnea and sleep improved in response to multidisciplinary weight loss interventions in youth with obesity? A systematic review and meta-analysis

BACKGROUND

Pediatric obesity is closely associated with obstructive sleep apnea (OSA) and short sleep duration. While multidisciplinary weight loss interventions are recommended for pediatric obesity management, the evidence for their effects on OSA severity and overall sleep in youth have not been systematically examined.

OBJECTIVES

To conduct a systematic review and meta-analysis investigating the effects of multidisciplinary weight loss interventions on OSA severity and prevalence, and on overall sleep health in youth with obesity.

METHODS

A systematic search of interventional studies (participants age range: 10-19 yrs) was performed using PubMed, CENTRAL and Embase, from inception to May 2019. The quality of the evidence was assessed using the Cochrane risk of bias tool.

RESULTS

Ten studies were included by the end of the screening process. Ninety percent of the included studies reported a decrease in OSA prevalence post-intervention, and OSA was normalized for 46.2-79.7% of the youth. The meta-analysis comprising seven longitudinal studies revealed significant reductions in apnea-hypopnea index (effect size: -0.51, 95%CI -0.94 to -0.08, p = 0.019), and oxygen desaturation index (effect size: -0.28, 95%CI = -0.50 to -0.05, p = 0.016). Seventy-five percent of the studies reported improved sleep duration in youth with OSA.

CONCLUSIONS

Evidence suggests that multidisciplinary weight loss interventions result in improvements in OSA severity and sleep duration in youth with obesity. Future randomized controlled trials are warranted to better assess and understand the independent implications of weight loss, fat mass decrease and chronic exercise on OSA and sleep health in this population.

Feasibility and effectiveness of thoracic spine mobilization on sympathetic/parasympathetic balance in a healthy population - a randomized controlled double-blinded pilot study

Background

Physiotherapists often use thoracic spine mobilization (TSM) to reduce pain in patients with back disorders via a reduction of sympathetic activity. There is a "trade-off" in the activity of the sympathetic and parasympathetic nervous system activity. A sympathetic/parasympathetic balance (SPB) is needed to guarantee body homeostasis. However, body homeostasis is seldom considered as an aim of the treatment from the perspective of most physiotherapists. Strong empirical evidence for the effects of TSM on the SPB is still lacking.Some studies showed that spinal manipulation may yield beneficial effects on SPB. Therefore, it could be hypothesized that TSM is feasible and could influence SPB reactions. The primary aim was to describe the participants' adherence to the intervention and to the measurement protocol, to identify unexpected adverse events (UAE) after TSM, to evaluate the best method to measure SPB parameters (heart rate variability (HRV), blood pressure (BP), heart rate (HR), skin perfusion and erythema) and to estimate the investigation procedure. The secondary aim was to assess the effects of TSM on SPB parameters in a small sample of healthy participants.

Methods

This crossover pilot study investigated TSM using posterior-anterior mobilization (PAM) and anterior-posterior mobilization (APM) on segments T6 to T12 in twelve healthy participants during two consecutive days. To evaluate feasibility, the following outcomes were assessed: adherence, UAE, data collection and data analysis. To evaluate the effect of TSM on SPB, HRV, BP, HR, skin perfusion and erythema were measured.

Results

The adherence was 100%. No UAE were reported. PAM showed larger effect sizes compared to APM in many secondary variables.

Conclusions

Although 100% maximal adherence was reached and no UAE were observed, data recording in future studies should be done during a second time interval while the data transfer from device to the computer software should occur immediately after completion of each participant's measurement. The results of this pilot study suggest that PAM can reduce HRV HF and HRV ratio LF/HF and increase HR.

Trial registration

ClinicalTrail.gov (NCT02832141).

Is spontaneous normalization of systolic blood pressure within 24 hours after ischemic stroke onset related with favorable outcomes?

Background

In acute ischemic stroke, blood pressure (BP) tends to rise initially and fall to a baseline level within 24–48 hours. Previous studies reported several different effects of BPs during acute ischemic stroke on clinical outcomes, which was partly due to the different time intervals from stroke onset to BP measurement.

Methods

All patients with acute ischemic stroke (onset ≤3 hours) who lived independently before the stroke, were consecutively enrolled for a 62-month period. BPs at 0, 12, and 24 hours after admission were collected. A favorable outcome was defined as a modified Rankin Scale (mRS) score 0–2 at discharge. For different standards of BP management, patients were grouped and analyzed according to intravenous (IV) tissue plasminogen activator (tPA) treatment and favorable outcome.

Results

Among the 446 enrolled patients, 227 patients underwent IV tPA treatment and 216 had mRS score 0–2 at discharge. Patients with favorable outcomes had lower initial NIH Stroke Scale (NIHSS) scores, less frequent progressive neurological deficits, and lower systolic BP (SBP) 12 and 24 hours after admission than patients with unfavorable outcomes, regardless of whether they underwent tPA treatment or not (p <0.05). The BP decreased over a period of 24 hours after admission. In logistic regression analysis, the independent variables associated with favorable outcome were the initial NIHSS score, a progressive neurological deficit, a previous stroke, and the SBP 24 hours after admission in the patients who underwent tPA treatment and the initial NIHSS score and a progressive neurological deficit in the patients who did not undergo tPA treatment (p <0.05).

Conclusions

The SBPs at 12 and 24 hours after admission were lower in acute stroke patients with favorable outcomes than in the other patients, regardless of whether the patients underwent tPA therapy and the SBP at 24 hours was an independent predictor of favorable outcomes among the patients who underwent tPA treatment.

Changes in heart rate and blood pressure during nocturnal hot flashes associated with and without awakenings

Hot flashes (HFs) are a hallmark of menopause in midlife women. They are beyond bothersome symptoms, having a profound impact on quality of life and wellbeing, and are a potential marker of cardiovascular (CV) disease risk. Here, we investigated the impact on CV functioning of single nocturnal HFs, considering whether or not they were accompanied by arousals or awakenings. We investigated changes in heart rate (HR, 542 HFs), blood pressure (BP, 261 HFs), and pre-ejection period (PEP, 168 HFs) across individual nocturnal physiological HF events in women in the menopausal transition or post-menopause (age: 50.7 ± 3.6 years) (n = 86 for HR, 45 for BP, 27 for PEP). HFs associated with arousals/awakenings (51.1%), were accompanied by an increase in systolic (SBP; ~6 mmHg) and diastolic (DBP; ~5 mmHg) BP and HR (~20% increase), sustained for several minutes. In contrast, HFs occurring in undisturbed sleep (28.6%) were accompanied by a drop in SBP and a marginal increase in HR, likely components of the heat dissipation response. All HFs were accompanied by decreased PEP, suggesting increased cardiac sympathetic activity, with a prolonged increase for HFs associated with sleep disruption. Older age predicted greater likelihood of HF-related sleep disturbance. HFs were less likely to wake a woman in rapid-eye-movement and slow-wave sleep. Findings show that HFs associated with sleep disruption, which are in the majority and more likely in older women, lead to increases in HR and BP, which could have long-term impact on nocturnal CV restoration in women with multiple HFs.

Lung air trapping lowers respiratory arousal threshold and contributes to sleep apnea pathogenesis in COPD patients with overlap syndrome

STUDY OBJECTIVES

Overlap syndrome occurs when obstructive sleep apnea (OSA) and chronic obstructive pulmonary disorder (COPD) coexist in the same patient. Although several studies highlighted the importance of clinical phenotyping in OSA, the trait contribution to OSA pathogenesis in overlap syndrome has not been investigated. With this pilot study, we aimed to measure OSA determinants and their relationship with functional respiratory parameters in a sample of patients with overlap syndrome. In particular, we hypothesize that patients with COPD have in the low arousal threshold a major contributor for the development of OSA.

METHODS

Ten consecutive non-hypercapnic COPD patients (body mass index<35 kg/m²) suffering from overlap syndrome with no other relevant comorbidities underwent a phenotyping polysomnography. Traits were measured with CPAP dial-downs.

RESULTS

Arousal threshold was found to be inversely associated to functional measures of lung air trapping and static hyperinflation. Particularly, correlations with residual volume (r² = 0.49, p =  0.024) and residual volume to total lung capacity ratio (r² = 0.48, p =  0.026) were evident. Only 20% of patients showed a high upper airway passive collapsibility as single pathological trait. In contrast, among those patients with multiple altered traits (6 out of 10), all had an elevated loop gain and 4 (∼65%) a low arousal threshold.

CONCLUSIONS

High loop gain and particularly low arousal threshold seem important contributors to OSA pathogenesis and severity in patients with COPD. Recognizing in COPD patients these features as key traits may open avenues for personalized medicine in the field of overlap syndrome.

Association between snoring and heart rate variability in adolescents: effects of gender and insufficient sleep

PURPOSE

We explored the association between subjective snoring frequency and heart rate variability (HRV) in a healthy adolescent population.

METHODS

A total of 102 healthy adolescents were recruited from high schools in South Korea, and reported their sleep habits and snoring frequency. HRV was assessed to indirectly measure autonomic function. We assessed correlations between snoring frequency and HRV indices. We also investigated the effects of sex and behaviorally induced insufficient sleep syndrome (BISS) on the associations between HRV parameters and snoring frequency.

RESULTS

Overall, significant correlations were apparent between snoring frequency and HRV indices including the standard deviation of the normal-to-normal intervals (SDNN) and the low-frequency/high-frequency (LF/HF) ratio. Associations were more evident in males and those with BISS compared to females and those without BISS.

CONCLUSIONS

Our findings suggest that snoring changes autonomic nervous system (ANS) activity in adolescents; the changes are more dramatic in males and those with insufficient sleep.

Ambulatory Blood Pressure at Sea Level and High Altitude in a Climber with a Kidney Transplant and Hypertension

Background and Objectives: High altitude may increase blood pressure (BP) and the kidney plays an important role in acclimatization. Little is known about how transplanted kidneys respond to the hypoxic stress at high altitude. We compared 24 hour ambulatory BP in a climber with a kidney transplant and hypertension at sea level and at high altitude (2860-4300 m). Methods: Welch-Allyn ABPM 6100 monitor was used to collect heart rate, systolic BP (SBP), and diastolic BP every 30 minutes while awake, and hourly while asleep. BP was monitored for 49 hours at sea level and for 53 hours at 2860-4300 m. Results: Overall mean SBP did not differ between altitudes. At high altitude, the participant's mean nocturnal BP increased, but this "reverse dipping" pattern was not observed at sea level. The participant had no evidence of altitude illness or infectious complications at high altitude. Conclusions: This case builds on previous reports that kidney transplant recipients may safely travel to high altitude. Further study is required to determine the generalizability to other travelers with kidney transplant and/or underlying hypertension, and the clinical significance of short-term elevated nocturnal BP at high altitude.