Heart rate and heart rate variability modification in chronic insomnia patients

Erectile dysfunction as a holistic indicator of well-being: a narrative review

INTRODUCTION

Erectile dysfunction (ED), affecting around 52% of men aged 40-70, is a significant marker of overall health and a potential warning sign of multiple conditions like cardiovascular diseases (CVDs), diabetes, and mental health disorders. Recognizing and addressing ED through a holistic approach involving nutrition, physical activity, sleep, and stress management can improve both erectile and overall health outcomes.

AIMS

To provide a narrative review of the available literature on the relationship between ED and overall health, elaborate on the possible mechanisms explaining this association, and discuss the effects of lifestyle on ED.

METHODS

A search of the medical literature was carried out in PubMed and Medline, focusing on original research and systematic reviews of original research on ED and overall health.

RESULTS

Due to shared pathophysiological mechanisms like endothelial dysfunction, ED is a significant indicator of overall health, particularly related to CVD and diabetes mellitus. Multiple studies have shown that ED frequently precedes cardiovascular events and is associated with increased cardiovascular risk, especially in younger men and those with diabetes. It also has a profound, bidirectional relationship with mental health conditions like depression and anxiety, creating a vicious cycle where each exacerbates the other. The four health pillars of nutrition, physical activity, sleep, and stress management play significant roles in erectile function and overall sexual health.

CONCLUSION

ED is not just a condition affecting sexual function but a critical indicator of broader health issues. By adopting an integrative approach that combines nutrition, physical activity, sleep, and stress management, healthcare providers can offer holistic and effective management strategies for this condition.

Predicting response to stepped-care cognitive behavioral therapy for insomnia using pre-treatment heart rate variability in cancer patients

OBJECTIVE

This study examined whether high frequency heart-rate variability (HF-HRV) and HF-HRV reactivity to worry moderate response to cognitive behavioural therapy for insomnia (CBT-I) within both a standard and stepped-care framework among cancer patients with comorbid insomnia. Biomarkers such as HF-HRV may predict response to CBT-I, a finding which could potentially inform patient allocation to different treatment intensities within a stepped-care framework.

METHODS

177 participants (86.3 % female; Mage = 55.3, SD = 10.4) were randomized to receive either stepped-care or standard CBT-I. 145 participants had their HRV assessed at pre-treatment during a rest and worry period. Insomnia symptoms were assessed using the Insomnia Severity Index (ISI) and daily sleep diary across five timepoints from pre-treatment to a 12-month post-treatment follow-up.

RESULTS

Resting HF-HRV was significantly associated with pre-treatment sleep efficiency and sleep onset latency but not ISI score. However, resting HF-HRV did not predict overall changes in insomnia across treatment and follow-up. Similarly, resting HF-HRV did not differentially predict changes in sleep diary parameters across standard or stepped-care groups. HRV reactivity was not related to any of the assessed outcome measures in both cross-sectional and longitudinal analyses.

CONCLUSION

Although resting HF-HRV was related to initial daily sleep parameters, HF-HRV measures did not significantly predict longitudinal responses to CBT-I. These findings suggest that HF-HRV does not predict treatment responsiveness to CBT-I interventions of different intensity in cancer patients.

Vagal predominance correlates with mood state changes of winter-over expeditioners during prolonged Antarctic residence

OBJECTIVE

Winter-over expeditioners in Antarctica are challenged by various environmental and psycho-social stress factors, which may induce psychophysiological changes. The autonomic nervous system (ANS) plays a crucial role in the adaptation process under stress. However, the relationship between ANS activity and the mood states of expeditioners remains largely unexplored. This study aims to uncover the pattern of ANS adjustment under extreme Antarctic environments and provide new insights into the correlations between ANS activity and mood state changes, which may provide scientific data for medical interventions.

METHODS

Fourteen expeditioners at Zhongshan Station participated in this study. The study was conducted during four representative periods: pre-Antarctica, Antarctica-1 (pre-winter), Antarctica-2 (winter), and Antarctica-3 (summer). The heart rate variability (HRV) of the expeditioners was continuously measured for 24 hours to evaluate ANS activity. Plasma levels of catecholamines were tested by ELISA. Mood states were assessed by the Profile of Mood States (POMS) scale.

RESULTS

HRV analysis showed a disturbance of ANS during winter and summer periods. For frequency domain parameters, very low frequency (VLF), low frequency (LF), high frequency (HF), and total power (TP) significantly increased during the second half of the mission. Especially, LF/HF ratio decreased during summer, indicating the predominance of vagal tone. Results of the time domain analysis showed increased heart rate variability during the austral winter and summer. Plasma epinephrine (E) significantly increased during residence in Antarctica. Compared with pre-Antarctica, the vigor, depression, and anger scores of the expeditioners decreased significantly during the austral summer. Notably, the depression score showed a moderate positive correlation with LF/HF, while weak negative correlations with other HRV indicators, including TP, VLF, and LF. Anger score showed a moderate positive correlation with LF/HF and weak negative correlations with the average normal-to-normal (NN) interval, and the root mean square of differences between adjacent RR intervals (RMSSD). Plasma E level weakly correlated with the average NN interval.

CONCLUSION

Prolonged residence in Antarctica increased the ANS activities and shifted the cardiac autonomic modulation towards vagal predominance. The alteration of HRV correlated with mood states and plasma epinephrine levels.

The Role of Sleep in Cardiovascular Disease

PURPOSE OF REVIEW

Sleep is an important component of cardiovascular (CV) health. This review summarizes the complex relationship between sleep and CV disease (CVD). Additionally, we describe the data supporting the treatment of sleep disturbances in preventing and treating CVD.

RECENT FINDINGS

Recent guidelines recommend screening for obstructive sleep apnea in patients with atrial fibrillation. New data continues to demonstrate the importance of sleep quality and duration for CV health. There is a complex bidirectional relationship between sleep health and CVD. Sleep disturbances have systemic effects that contribute to the development of CVD, including hypertension, coronary artery disease, heart failure, and arrhythmias. Additionally, CVD contributes to the development of sleep disturbances. However, more data are needed to support the role of screening for and treatment of sleep disorders for the prevention of CVD.

Altered parasympathetic activity during sleep and emotionally arousing wakefulness in frequent nightmare recallers

Nightmare disorder is characterized by dysfunctional emotion regulation and poor subjective sleep quality reflected in pathophysiological features such as abnormal arousal processes and sympathetic influences. Dysfunctional parasympathetic regulation, especially before and during rapid eye movement (REM) phases, is assumed to alter heart rate (HR) and its variability (HRV) of frequent nightmare recallers (NM). We hypothesized that cardiac variability is attenuated in NMs as opposed to healthy controls (CTL) during sleep, pre-sleep wakefulness and under an emotion-evoking picture-rating task. Based on the polysomnographic recordings of 24 NM and 30 CTL participants, we examined HRV during pre-REM, REM, post-REM and slow wave sleep, separately. Additionally, electrocardiographic recordings of resting state before sleep onset and under an emotionally challenging picture-rating task were also analyzed. Applying repeated measures analysis of variance (rmANOVA), a significant difference was found in the HR of NMs and CTLs during nocturnal segments but not during resting wakefulness, suggesting autonomic dysregulation, specifically during sleep in NMs. As opposed to the HR, the HRV values were not significantly different in the rmANOVA in the two groups, implying that the extent of parasympathetic dysregulation on a trait level might depend on the severeness of dysphoric dreaming. Nonetheless, in the group comparisons, the NM group showed increased HR and reduced HRV during the emotion-evoking picture-rating task, which aimed to model the nightmare experience in the daytime, indicating disrupted emotion regulation in NMs under acute distress. In conclusion, trait-like autonomic changes during sleep and state-like autonomic responses to emotion-evoking pictures indicate parasympathetic dysregulation in NMs.

Monitoring differences in the function of the autonomic nervous system in patients with chronic insomnia using a wearable device

STUDY OBJECTIVES

to characterize possible differences in the function of the ANS in patients with chronic insomnia compared to a control group, using a wearable device, in order to determine whether those findings allow diagnosing this medical entity.

METHODS

Thirty-two patients with chronic insomnia and nineteen patients without any sleep disorder, as a control group, were recruited prospectively. Both groups of patients underwent an in-patient night with simultaneous polysomnography and wearable device recording Empatica E4 a diverse array of physiological signals, including electrodermal activity, temperature, accelerometry, and photoplethysmography, providing a comprehensive resource for in-depth sleep analysis.

RESULTS

In polysomnography, patients suffering from insomnia showed a significant decrease in sleep efficiency and total sleep time, prolonged sleep latency, and increased wakefulness after sleep onset. Accelerometry results were statistically significant differences in the three axis (x, y, z) just in stage N3, no differences were observed between both groups in REM sleep. The lowest temperature was reached in REM sleep in both groups. Peripheral temperature did not decrease during the different sleep phases compared to wakefulness in insomnia, unlike in the control group. Heart rate was higher in patients with insomnia than in controls during wakefulness and sleep stage. Heart rate variability was lower in stage N3 and higher in REM sleep compared to wakefulness in both groups. Sweating was significantly higher in patients with insomnia compared to the control group, as indicated by Skin Conductance Variability values and Sudomotor Nerve.

CONCLUSIONS

Our study suggests that patients with insomnia have increased sympathetic activity during sleep, showing a higher heart rate. Temperature and sweating significantly influence the different sleep phases.

Hyperarousal in insomnia disorder: Current evidence and potential mechanisms

Insomnia disorder is among the most frequent mental disorders, making research on its aetiology and pathophysiology particularly important. A unifying element of many aetiological and pathophysiological models is that they support or even centre on the role of some form of hyperarousal. In this theoretical review, we aim to summarise the current evidence on hyperarousal in insomnia. Hyperarousal is discussed as a state of relatively increased arousal in physiological, cortical and cognitive-emotional domains. Regarding physiological hyperarousal, there is no conclusive evidence for the involvement of autonomous variables such as heart rate and heart rate variability, whereas recent evidence points to a pathophysiological role of neuroendocrine variables. In addition, current literature supports a central involvement of cortical arousal, that is, high-frequency electroencephalographic activity. An increasingly important focus in the literature is on the role of other microstructural sleep parameters, especially the existence of microarousals during sleep. Beyond that, a broad range of evidence exists supporting the role of cognitive-emotional hyperarousal in the form of insomnia-related thought and worries, and their concomitant emotional symptoms. Besides being a state marker of insomnia, hyperarousal is considered crucial for the predisposition to insomnia and for the development of comorbid mental disorders. Thus, beyond presenting evidence from cross-sectional studies on markers of hyperarousal in insomnia, hypotheses about the mechanisms of hyperarousal are presented. Nevertheless, longitudinal studies are needed to further elucidate the mechanism of hyperarousal throughout the course of the disorder, and future studies should also focus on similarities and differences in hyperarousal across different diagnostic entities.

Somno-Art Software identifies pathology-induced changes in sleep parameters similarly to polysomnography

Polysomnographic sleep architecture parameters are commonly used to diagnose or evaluate treatment of sleep disorders. Polysomnography (PSG) having practical constraints, the development of wearable devices and algorithms to monitor and stage sleep is rising. Beside pure validation studies, it is necessary for a clinician to ensure that the conclusions drawn with a new generation wearable sleep scoring device are consistent to the ones of gold standard PSG, leading to similar interpretation and diagnosis. This paper reports on the performance of Somno-Art Software for the detection of differences in sleep parameters between patients suffering from obstructive sleep apnea (OSA), insomniac or major depressive disorder (MDD) compared to healthy subjects. On 244 subjects (n = 26 healthy, n = 28 OSA, n = 66 insomniacs, n = 124 MDD), sleep staging was obtained from PSG and Somno-Art analysis on synchronized electrocardiogram and actimetry signals. Mixed model analysis of variance was performed for each sleep parameter. Possible differences in sleep parameters were further assessed with Mann-Whitney U-test between the healthy subjects and each pathology group. All sleep parameters, except N1+N2, showed significant differences between the healthy and the pathology group. No significant differences were observed between Somno-Art Software and PSG, except a 3.6±2.2 min overestimation of REM sleep. No significant interaction 'group'*'technology' was observed, suggesting that the differences in pathologies are independent of the technology used. Overall, comparable differences between healthy subjects and pathology groups were observed when using Somno-Art Software or polysomnography. Somno-Art proposes an interesting valid tool as an aid for diagnosis and treatment follow-up in ambulatory settings.

Amygdala resting-state functional connectivity alterations in patients with chronic insomnia disorder: correlation with electroencephalography beta power during sleep

STUDY OBJECTIVES

This study investigated alterations in resting-state functional connectivity (RSFC) and hyperarousal biomarkers in patients with chronic insomnia disorder (CID), compared with good sleepers (GS). We also examined the relationships between altered RSFC and hyperarousal biomarkers.

METHODS

Fifty patients with CID and 52 GS completed self-reporting questionnaires, and then underwent polysomnography and resting-state functional magnetic resonance imaging. We analyzed RSFC in the amygdala (AMG) and anterior insula (aINS), which are core regions of the salience network that are likely to be involved in hyperarousal. We also analyzed electroencephalography (EEG) relative beta power and heart rate variability (HRV) parameters (e.g. low and high frequency) during sleep. We then tested between-group differences in the RSFC and hyperarousal biomarkers; we examined correlations of RSFC with EEG beta power and HRV.

RESULTS

Compared with GS, patients with CID showed more negative RSFC between the right amygdala (R.AMG) and left supramarginal gyrus (L.SMG), but less positive RSFC between the left aINS and bilateral lateral prefrontal cortex. The R.AMG-L.SMG RSFC was negatively correlated with EEG beta power in central regions (C3: r = -0.336, p = 0.012; C4: r = -0.314, p = 0.024).

CONCLUSIONS

Decreased RSFC between the R.AMG and L.SMG in patients with insomnia may reflect the difficulty in cortical top-down regulation of the AMG, indicating daytime hyperarousal. Individuals who experience hyperarousal during the daytime may also exhibit cortical hyperarousal during sleep, as indicated by increased EEG beta power.

The potential of biomarkers for diagnosing insomnia: Consensus statement of the WFSBP Task Force on Sleep Disorders

OBJECTIVES

Thus far, the diagnosis of insomnia is based on purely clinical criteria. Although a broad range of altered physiological parameters has been identified in insomniacs, the evidence to establish their diagnostic usefulness is very limited. Purpose of this WFSBP Task Force consensus paper is to systematically evaluate a series of biomarkers as potential diagnostic tools for insomnia.

METHODS

A newly created grading system was used for assessing the validity of various measurements in establishing the diagnosis of insomnia; these measurements originated from relevant studies selected and reviewed by experts.

RESULTS

The measurements with the highest diagnostic performance were those derived from psychometric instruments. Biological measurements which emerged as potentially useful diagnostic instruments were polysomnography-derived cyclic alternating pattern, actigraphy, and BDNF levels, followed by heart rate around sleep onset, deficient melatonin rhythm, and certain neuroimaging patterns (mainly for the activity of frontal and pre-frontal cortex, hippocampus and basal ganglia); yet, these findings need replication, as well as establishment of commonly accepted methodology and diagnostic cut-off points. Routine polysomnography, EEG spectral analysis, heart rate variability, skin conductance, thermoregulation, oxygen consumption, HPA axis, and inflammation indices were not shown to be of satisfactory diagnostic value.

CONCLUSIONS

Apart from psychometric instruments which are confirmed to be the gold standard in diagnosing insomnia, six biomarkers emerge as being potentially useful for this purpose.

INSOMNet: Automated insomnia detection using scalogram and deep neural networks with ECG signals

Sleep is a natural state of rest for the body and mind. It is essential for a human's physical and mental health because it helps the body restore itself. Insomnia is a sleep disorder that causes difficulty falling asleep or staying asleep and can lead to several health problems. Conventional sleep monitoring and insomnia detection systems are expensive, laborious, and time-consuming. This is the first study that integrates an electrocardiogram (ECG) scalogram with a convolutional neural network (CNN) to develop a model for the accurate measurement of the quality of sleep in identifying insomnia. Continuous wavelet transform has been employed to convert 1-D time-domain ECG signals into 2-D scalograms. Obtained scalograms are fed to AlexNet, MobileNetV2, VGG16, and newly developed CNN for automated detection of insomnia. The proposed INSOMNet system is validated on the cyclic alternating pattern (CAP) and sleep disorder research center (SDRC) datasets. Six performance measures, accuracy (ACC), false omission rate (FOR), sensitivity (SEN), false discovery rate (FDR), specificity (SPE), and threat score (TS), have been calculated to evaluate the developed model. Our developed system attained the classifications ACC of 98.91%, 98.68%, FOR of 1.5, 0.66, SEN of 98.94%, 99.31%, FDR of 0.80, 2.00, SPE of 98.87%, 98.08%, and TS 0.98, 0.97 on CAP and SDRC datasets, respectively. The developed model is less complex and more accurate than transfer-learning networks. The prototype is ready to be tested with a huge dataset from diverse centers.

Effect of one-shot cognitive behavioral therapy on insomnia and heart rate variability of health care workers at the time of COVID-19 pandemic: a randomized controlled trial

OBJECTIVES

The emergence of sleep disturbances in response to major stressful events has been previously documented. Heart rate variability (HRV) is an objective marker that provides insight into autonomic nervous system dynamics. The aim of the present study was to examine the preliminary effectiveness of a one-shot session of cognitive behavioral therapy for insomnia (CBT-I) for frontline healthcare providers with acute insomnia.

METHODS

This study was conducted from 2020 to 2021 on healthcare workers with insomnia. The healthcare workers were randomly allocated to receive either one-shot cognitive behavioral therapy or routine care. Insomnia severity index (ISI) and heart rate variability were assessed before and 1 month after the interventions.

RESULTS

Among 57 patients (n = 31 in the intervention group and n = 26 in the control group), mean (± SD) age of both groups were 34.6 (± 9.5) and 36.6 (± 6.9), respectively. Most participants in both groups were female (81% and 65% in the intervention and control groups, respectively; p-value = 0.10). Insomnia severity index score decreased in the intervention group from 13.3 to 6.7 (p < 0.001). The change before and after the intervention was significant between the two groups for HF-normalized unit (high-frequency power band [0.15-0.40 Hz] in the normalized unit) and LF/HF (the ratio of low frequency to high frequency). HF-normalized unit increased in the intervention group (35.8 ± 21.5 vs. 45.6 ± 19.8 before and after the intervention, respectively), and decreased in the control group (43.9 ± 16.5 vs. 39.8 ± 18.5, before and after the intervention, respectively).

CONCLUSION

The findings suggest that a single-shot session of cognitive behavioral therapy for insomnia is effective in managing acute insomnia symptoms in healthcare workers.

Heart rate variability in patients with insomnia disorder: a systematic review and meta-analysis

BACKGROUND

Though logical inference based on small studies suggests that patients with insomnia have a blunted heart rate variability (HRV), this condition not been clearly shown. This meta-analysis aimed to determine whether or not HRV was impaired in patients with insomnia.

MATERIALS AND METHODS

We conducted a comprehensive literature search for studies that examined the association of HRV with insomnia disorder. HRV measures were extracted using the SDNN (time-domain measure, i.e., standard deviation of all NN intervals,) or the HF-norm (frequency-domain measure, i.e., high-frequency power normalized using total power). The effect size estimates of R_equivalent obtained from p values and sample size were synthesized.

RESULTS

We identified 17 studies with 921 participants. The pooled R_equivalent was 0.19 with 95% CI of 0.12 and 0.25 (p < 0.001), and there was no significant heterogeneity (I2 = 0.0%, p = 0.809). A p value of 0.075 corresponding to the R_equivalent of 0.19 was obtained, suggesting that blunted HRV was not significant in patients with insomnia disorder.

CONCLUSION

The current evidence did not confirm that HRV was reliably impaired in patients with insomnia disorder. Prospective studies using standard HRV measures are needed to clarify the HRV dynamics in different insomnia subtypes.

Mood Disorders are Correlated with Autonomic Nervous Function in Chronic Insomnia Patients with OSA

Purpose

To evaluate the correlation between sleep microstructure, autonomic nervous system activity, and neuropsychological characteristics in chronic insomnia (CI) patients with obstructive sleep apnea (OSA).

Patients and Methods

Forty-five CI-OSA patients, forty-six CI patients and twenty-two matched healthy control subjects (HCs) were enrolled. CI-OSA patients were then divided into two groups: mild OSA and moderate-to-severe OSA. All participants completed neuropsychological tests, which included the Hamilton Depression and Anxiety Scales (HAMD and HAMA), the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale (ESS), and the Mini-mental State Examination (MMSE). The autonomic nervous system activity and sleep microstructure were examined by the PSM-100A.

Results

The CI-OSA patients exhibited higher scores on the PSQI, ESS, ISI, HAMA, and HAMD than HCs and CI patients (all p < 0.01). The CI-OSA patients had a lower proportion of stable sleep, REM sleep and a higher proportion of unstable sleep ratio (all p < 0.01) than HCs and CI patients (all p < 0.01). The CI-OSA patients had higher ratios of LF and LF/HF, and lower ratios of HF and Pnn50% (all p < 0.01) than HCs and CI patients (all p < 0.01). Compared to CI-mild OSA patients, the CI-moderate-to-severe OSA patients presented with a higher ESS scores, higher ratios of LF and LF/HF, and lower ratios of HF (all p < 0.05). In CI-OSA patients, higher HAMD scores were correlated with decreased MMSE scores (r=-0.678, p < 0.01). A higher LF ratio was correlated with higher HAMD and HAMA scores (r=0.321, p=0.031, r =0.449, p =0.002), and a higher HF ratio was correlated with lower HAMD and HAMA scores (r=-0.321, P =0.031, r =-0.449, p =0.002).

Conclusion

OSA exacerbates the abnormalities of sleep microstructure and the autonomic nervous dysfunction in CI patients. Dysfunction of the autonomic nervous system could contribute to mood deterioration in CI with OSA patients.

Cereset Research Standard Operating Procedures for Insomnia: A Randomized, Controlled Clinical Trial

Background

Interventions for insomnia that also address autonomic dysfunction are needed.

Objective

We evaluate Cereset Research™ Standard Operating Procedures (CR-SOP) in a pilot randomized, controlled trial. CR-SOP is a less operator-dependent, more generalizable innovation of HIRREM®, a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology demonstrated to improve insomnia and autonomic function.

Methods

Adults with Insomnia Severity Index (ISI) scores of ≥8 were randomized to receive ten sessions of CR-SOP, with tones linked to brainwaves (LB, intervention), or a sham condition of random tones not linked to brainwaves (NL, control). Measures were collected at enrollment and 0-14 days and 4-6 weeks post-allocated intervention. The primary outcome was differential change in ISI from baseline to 4-6 weeks post-intervention. Secondary self-report measures assessed sleep quality65 and behavioral outcomes. Ten-minute recordings of heart rate and blood pressure were collected to analyze autonomic function (heart rate variability [HRV] and baroreflex sensitivity).

Results

Of 22 randomized, 20 participants completed the allocated condition. Intention to treat analysis of change from baseline to the 4-6 week outcome demonstrated mean ISI score reduction of 4.69 points among controls (SE 1.40). In the intervention group, there was an additional 2.58 point reduction in ISI score (SE 2.13; total reduction of 7.27, P = .24). Sleep quality and some measures of autonomic function improved significantly among the intervention group compared to control.

Conclusions

This pilot study compared use of a standardized, allostatic, acoustic neurotechnology intervention with a sham, active control condition. The magnitude of change in insomnia severity was clinically relevant and similar to the findings in a prior, fully powered trial, but the differential improvement observed was not statistically significant. Significant improvements were demonstrated in sleep quality and some autonomic function measures.

Associations between sleep-related heart rate variability and both sleep and symptoms of depression and anxiety: A systematic review

There is a bidirectional relationship between poor sleep and both mood- and anxiety-related disorders, which are among leading global health concerns. Additionally, both disordered sleep and these psychiatric disorders appear to be independently associated with altered autonomic nervous system (ANS) function. We hypothesise that ANS dysregulation during sleep may explain part of the relationship between poor sleep and mood- and anxiety-related disorders. Heart rate variability (HRV) is a frequently used marker of ANS function and gives an indication of ANS input to the heart - in particular, of the relative contributions of sympathetic and parasympathetic activity. A systematic review of PubMed, Scopus and Web of Science yielded 41 studies dealing with sleep, mood- and anxiety-related disorders and sleep-related HRV. Hyperarousal during sleep, reflecting a predominance of sympathetic activation and indicative of ANS dysregulation, may be an important factor in the association between poor sleep and mood-related disorders. Longitudinal studies and mediation analyses are necessary to further understand the potential mediating role of ANS dysregulation on the relationship between poor sleep and mood- and anxiety-related disorders.

Triad Multisystem Phenotype with High-risk for Developing Temporomandibular Disorders- Characteristics and Potential Pathophysiology Results from the OPPERA Dataset

ABSTRACT

A multisystem phenotype with the Triad of bodily pain, psychological distress, and sleep disturbance was found to have high risk for developing initial onset of painful temporomandibular disorders (TMDs) in the multicenter Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) dataset. In this study, we systemically examined phenotypic characteristics and explored potential pathophysiology in quantitative sensory testing (QST) and autonomic nervous system (ANS) domains in this multisystem Triad phenotype. Secondary analysis was performed on 1199 non-Triad and 154 Triad TMD-free OPPERA enrollees at baseline. Results indicate that prior to developing TMDs, the Triad phenotype demonstrated both orofacial and systemic signs and symptoms that can only be captured through multisystem assessment. In addition, we found significantly lower resting heart rate variability and higher resting heart rate in the Triad phenotype as compared to the non-Triad group. However, pain sensitivity measured by QST was not different between groups. These findings highlight the importance of whole-person multisystem assessment at the stage prior to developing complex pain conditions such as TMDs, and suggest that, in addition to a "tissue damage monitor", pain should be considered in a broader context, such as a component within a "distress monitoring system" at the whole-person level when multisystem issues co-present. Therefore, the presence or absence of multisystem issues may carry critical information when searching for disease mechanisms and developing mechanism-based intervention and prevention strategies for TMDs and related pain conditions. Cardiovascular autonomic function should be further researched when multisystem issues co-present prior to developing TMDs.

A Workcation Improves Cardiac Parasympathetic Function during Sleep to Decrease Arterial Stiffness in Workers

A “Workcation” (combining work and vacation) has become increasingly common. Traditionally, the workcation focus has been on productivity; however, data showing associations between workcations and improvements in employees’ health are lacking. Therefore, this study examines the effects of a workcation on blood pressure, arterial stiffness, heart rate, autonomic nervous system function, and physical activity. Twenty healthy employees participating in a five-day workcation project at a large private company agreed to participate in this study. Data on arterial stiffness, heart rate, autonomic nerve activity, and physical activity were collected before, during, and after the workcation. Arterial stiffness, blood pressure, and heart rate significantly decreased (p < 0.05); meanwhile, physical activity levels and parasympathetic function during sleep significantly increased during the workcation (p < 0.05). Thus, a workcation implies a new way of working that improves employees’ cardiovascular indices and parasympathetic function during sleep.

Temporal relations between peripheral and central arousals in good and poor sleepers

Good sleepers and patients with insomnia symptoms (poor sleepers) were tracked with two measures of arousal; conventional polysomnography (PSG) for electroencephalogram (EEG) assessed cortical arousals, and a peripheral arterial tonometry device was used for the detection of peripheral nervous system (PNS) arousals associated with vasoconstrictions. The relationship between central (cortical) and peripheral (autonomic) arousals was examined by evaluating their close temporal dynamics. Cortical arousals almost invariably were preceded and followed by peripheral activations, while large peripheral autonomic arousals were followed by cortical arousals only half of the time. The temporal contiguity of these two types of arousals was altered in poor sleepers, and poor sleepers displayed a higher number of cortical and peripheral arousals compared with good sleepers. Given the difference in the number of peripheral autonomic arousals between good and poor sleepers, an evaluation of such arousals could become a means of physiologically distinguishing poor sleepers.

Evaluating the Effects of Diet-Gut Microbiota Interactions on Sleep Traits Using the UK Biobank Cohort

Previous studies showed that diet and gut microbiota had a correlation with sleep. However, the potential interaction effects of diet and gut microbiota on sleep are still unclear. The phenotypic data of insomnia (including 374,505 subjects) and sleep duration (including 372,805 subjects) were obtained from the UK Biobank cohort. The Single Nucleotide Polymorphisms (SNPs) associated with 114 gut microbiota, 84 dietary habits, and 4 dietary compositions were derived from the published Genome-wide Association Study (GWAS). We used Linkage Disequilibrium Score Regression (LDSC) to estimate the genetic correlation and colocalization analysis to assess whether dietary habits and insomnia/sleep duration shared a causal variant in a region of the genome. Using UK Biobank genotype data, the polygenetic risk score of gut microbiota, dietary habits, and dietary compositions were calculated for each subject. Logistic regression and linear regression models were used to assess the potential effects of diet-gut microbiota interactions on sleep phenotypes, including insomnia and sleep duration. Insomnia and sleep duration were used as dependent variables, and sex, age, the Townsend Deprivation Index scores, and smoking and drinking habits were selected as covariates in the regression analysis. All statistical analyses were conducted using R-3.5.1 software. Significant genetic correlations were discovered between insomnia/sleep duration and dietary habits. Further, we found several significant dietary compositions-gut microbiota interactions associated with sleep, such as fat × G_Collinsella_RNT (p = 1.843 × 10-2) and protein × G_Collinsella_HB (p = 7.11 × 10-3). Besides, multiple dietary habits-gut microbiota interactions were identified for sleep, such as overall beef intake × G_Desulfovibrio_RNT (p = 3.26 × 10-4), cups of coffee per day × G_Escherichia_Shigella_RNT (p = 1.14 × 10-3), and pieces of dried fruit per day × G_Bifidobacterium_RNT (p = 5.80 × 10-3). This study reported multiple diet-gut microbiota interactions associated with sleep, which may provide insights into the biological mechanisms of diet and gut microbiota affecting sleep.

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

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

Neural activation changes in response to pain following cognitive behavioral therapy for patients with comorbid fibromyalgia and insomnia: a pilot study

STUDY OBJECTIVES

To examine whether cognitive behavioral treatments for insomnia (CBT-I) and pain (CBT-P) lead to neural activation changes in response to pain in fibromyalgia.

METHODS

Thirty-two patients with fibromyalgia (mean age = 55.9, standard deviation = 12.2) underwent an experimental pain protocol during functional magnetic resonance imaging and completed 14-day diaries assessing total wake time, total sleep time, and pain intensity before and after CBT-I, CBT-P, or waitlist control. Random effects analysis of covariance identified regions with significant group (CBT-I, CBT-P, waitlist control) by time (baseline, post-treatment) interactions in blood oxygen level-dependent response to pain. Linear regressions using residualized change scores examined how changes in total wake time, total sleep time, and pain intensity were related to activation (blood oxygen level-dependent) changes.

RESULTS

Twelve regions exhibited small to moderate effects with significant interactions Ps < .00; right hemisphere: inferior frontal, middle occipital, and superior temporal gyri, insula, lentiform nucleus; left hemisphere: angular, superior temporal, midfrontal, inferior occipital, midtemporal, and inferior frontal gyri. Blood oxygen level-dependent response to pain decreased in 8 regions following CBT-I, and in 3 regions following CBT-P (CBT-I effects > CBT-P). Blood oxygen level-dependent response also increased in 3 regions following CBT-P and in 6 regions following waitlist control. Improved total wake time and/or total sleep time, not pain intensity, predicted decreased blood oxygen level-dependence in 7 regions (Ps < .05), accounting for 18%-47% of the variance.

CONCLUSIONS

CBT-I prompted greater decreases in neural activation in response to pain across more regions associated with pain and sleep processing than CBT-P. Reported sleep improvements may underlie those decreases. Future research examining the longer-term impact of CBT-I and improved sleep on central pain and sleep mechanisms is warranted.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Sleep and Pain Interventions in Fibromyalgia (SPIN); Identifier: NCT02001077; URL: https://clinicaltrials.gov/ct2/show/NCT02001077.

CITATION

McCrae CS, Craggs JG, Curtis AF, et al. Neural activation changes in response to pain following cognitive behavioral therapy for patients with comorbid fibromyalgia and insomnia: a pilot study. J Clin Sleep Med. 2022;18(1):203-215.

Validation of the Thyrotoxicosis-associated Insomnia Model Induced by Thyroxine through Sympathetic Stimulation: Face, Construct and Predictive Perspectives

Insomnia has become a common central nervous system disease. At present, the pathogenesis of insomnia is not clear. Animal models can help us understand the pathogenesis of the disease and can be used in transformational medicine. Therefore, it is very necessary to establish an appropriate model of insomnia. Clinical data show that insomnia patients with high levels of thyroxine and often accompanied by cardiovascular problems, a common mechanism underlying all of these physiological disruptions is the sympathetic nervous system. Combined with the characteristics of chronic onset of clinical insomnia, an insomnia model induced by long-term intraperitoneal injection of thyroid hormone has been created in our laboratory. In this paper, the insomnia-like state of the model was evaluated based on three validity criteria. Face validity has been demonstrated in metabolism, the Morris water maze, electrocardiogram (ECG) and electroencephalogram (EEG). Structure validity has been proved by the results of targeted metabolomics. After treatment with diazepam, a commonly used clinical anti-insomnia drug, the above physiological and pathological disorders were reversed. The results of comprehensive analysis show that the established thyrotoxicosis-associated insomnia model meets the validity requirement to establish an appropriate animal model of insomnia. The model presented in this article might help to study pathogenetic mechanisms of clinical insomnia, as well as to test promising methods of insomnia treatment.

Neurofeedback for insomnia: Current state of research

BACKGROUND

Chronic insomnia affects about 6%-13% of the Canadian population. Although treatments already exist, they each have their own issues. Neurofeedback is a neuromodulation technique that specifically targets abnormal brain activity and is gaining attention as a possible insomnia treatment.

AIM

To review the latest studies pertaining to the use of neurofeedback in the treatment of insomnia.

METHODS

In this non-systematic review, only experimental studies assessing the effects of neurofeedback on patients with insomnia were targeted across four bibliographic databases.

RESULTS

A total of 12 studies were retained. All neurofeedback studies included in this study showed a clear improvement of subjective sleep. However, data concerning objective improvement are contradictory. Most studies regarding surface and z-score neurofeedback show that neurofeedback targeting the sensorimotor rhythm in the sensorimotor cortex may help improve subjective sleep. A placebo effect seems also to be present in some studies. Several limitations were present in each study.

CONCLUSION

While studies concerning neurofeedback as a treatment for insomnia are encouraging, many methodological barriers remain to be resolved to prove its efficacy unequivocally. More studies using robust design parameters, as well as the replication of existing studies, are necessary to support neurofeedback as an effective treatment for insomnia.

Sleep stage-dependent changes in tonic masseter and cortical activities in young subjects with primary sleep bruxism

STUDY OBJECTIVES

The present study investigated the hypothesis that subjects with primary sleep bruxism (SB) exhibit masseter and cortical hyperactivities during quiet sleep periods that are associated with a high frequency of rhythmic masticatory muscle activity (RMMA).

METHODS

Fifteen SB and ten control participants underwent polysomnographic recordings. The frequencies of oromotor events and arousals and the percentage of arousals with oromotor events were assessed. Masseter muscle tone during sleep was quantified using a cluster analysis. Electroencephalography power and heart rate variability were quantified and then compared between the two groups and among sleep stages.

RESULTS

The frequency of RMMA and percentage of arousals with RMMA were significantly higher in SB subjects than in controls in all stages, while these variables for non-rhythmic oromotor events did not significantly differ between the groups. In SB subjects, the frequency of RMMA was the highest in stage N1 and the lowest in stages N3 and R, while the percentage of arousals with RMMA was higher in stage N3 than stages N1 and R. The cluster analysis classified masseter activity during sleep into two clusters for masseter tone and contractions. Masseter muscle tone showed typical stage-dependent changes in both groups, but did not significantly differ between the groups. Furthermore, no significant differences were observed in electroencephalography power or heart rate variability between the groups.

CONCLUSION

Young SB subjects exhibited sleep stage-dependent increases in the responsiveness of RMMA to transient arousals, but did not show masseter or cortical hyperactivity during sleep.

The role of sleep disorders in cardiovascular diseases: Culprit or accomplice?

Sleep disorders frequently comorbid with several cardiovascular diseases (CVDs), attracting increasing scientific attention and interest. Sleep disorders include insomnia, sleep-disordered breathing, restless legs syndrome, etc. It is well known that inflammation, sympathetic activation, and endothelial dysfunction play critical roles in sleep disorders, all of which are predisposing factors for CVDs. The comorbidity of sleep disorders and CVDs may have a bidirectional relationship. Patients with CVDs may have a high incidence of sleep disorders and vice versa. This review focused on the comorbidity of sleep disorders and CVDs and discussed the potential pathophysiological mechanisms and therapeutic strategies. In addition to the existing mechanisms, this review summarized novel potential mechanisms underlying comorbidities, such as gut microbiota, orexin, and extracellular vesicles, which may provide a theoretical basis for further basic research and clinical investigations on improving therapeutic outcomes.

Presleep Arousal and Sleep in Early Childhood

Research suggests that arousal during the transition to sleep-presleep arousal-is associated with sleep disturbances. Although a robust literature has examined the role of presleep arousal in conferring risk for sleep disturbances in adults, substantially less research has examined the developmental origins of presleep arousal in early childhood. The authors examined presleep arousal using parent report and psychophysiological measures in a sample of preschoolers to explore the association between different measures of presleep arousal, and to examine how nightly presleep arousal is associated with sleep. Participants included 29 children assessed at 54 months of age. Presleep arousal was measured using parent reports of child arousal each night at bedtime and using a wearable device that took minute-by-minute recordings of heart rate, peripheral skin temperature, and electrodermal activity each night during the child's bedtime routine. This yielded a dataset with 4,550 min of ambulatory recordings across an average of 3.52 nights per child (SD = 1.84 nights per child; range = 1-8 nights). Sleep was estimated using actigraphy. Findings demonstrated an association between parent-reported and psychophysiological arousal, including heart rate, peripheral skin temperature, and skin conductance responses during the child's bedtime routine. Both the parent report and psychophysiological measures of presleep arousal showed some associations with poorer sleep, with the most robust associations occurring between presleep arousal and sleep onset latency. Behavioral and biological measures of hyperarousal at bedtime are associated with poorer sleep in young children. Findings provide early evidence of the utility of wearable devices for assessing individual differences in presleep arousal in early childhood.

Automatic identification of insomnia using optimal antisymmetric biorthogonal wavelet filter bank with ECG signals

Sleep is a fundamental human physiological activity required for adequate working of the human body. Sleep disorders such as sleep movement disorders, nocturnal front lobe epilepsy, insomnia, and narcolepsy are caused due to low sleep quality. Insomnia is one such sleep disorder where a person has difficulty in getting quality sleep. There is no definitive test to identify insomnia; hence it is essential to develop an automated system to identify it accurately. A few automated methods have been proposed to identify insomnia using either polysomnogram (PSG) or electroencephalogram (EEG) signals. To the best of our knowledge, we are the first to automatically detect insomnia using only electrocardiogram (ECG) signals without combining them with any other physiological signals. In the proposed study, an optimal antisymmetric biorthogonal wavelet filter bank (ABWFB) has been used, which is designed to minimize the joint duration-bandwidth localization (JDBL) of the underlying filters. The L₁-norm feature is computed from the various wavelet sub-bands coefficients of ECG signals. The L₁ norm features are fed to various supervised machine learning classifiers for the automated detection of insomnia. In this work, ECG recordings of seven insomnia patients and six normal subjects are used from the publicly available cyclic alternating pattern (CAP) sleep database. We created ten different subsets of ECG signals based on annotations of sleep-stages, namely wake (W), S1, S2, S3, S4, rapid eye moment (REM), light sleep stage (LSS), slow-wave sleep (SWS), non-rapid eye movement (NREM) and W + S1+S2+S3+S4+REM for the automated identification of insomnia. Our proposed ECG-based system obtained the highest classification accuracy of 97.87%, F1-score of 97.39%, and Cohen's kappa value of 0.9559 for K-nearest neighbour (KNN) with the ten-fold cross-validation strategy using ECG signals corresponding to the REM sleep stage. The support vector machine (SVM) yielded the highest value of 0.99 for area under the curve with the ten fold cross-validation corresponding to REM sleep stage.

Difficulty in initiating sleep is associated with poor morning cardiovascular function

Insomnia is a risk factor for hypertension and cardiovascular events, and this association is strongest for sleep-onset insomnia. This study explored morning cardiovascular function in individuals with sleep-onset insomnia by analysing heart rate variability (HRV), blood pressure variability, and baroreflex sensitivity. Sleep quality of fifteen good sleepers and 13 individuals with sleep-onset insomnia was measured by overnight polysomnography, followed by continuous recordings of the participant's blood pressure and heart rate for 10 min immediately after they had woken up the following morning. After morning awakening (averaged time: 12.33 ± 10.48 min), a significantly reduced vagal tone assessed by HRV, including lower total power of HRV, lower high frequency of HRV, and elevated slopes of systolic as well as diastolic blood pressure in the morning with a blunted baroreflex sensitivity in the insomnia group were noted, compared to the control group. No differences in sympathetic-related activity were observed. The regulation of cardiovascular activity by the parasympathetic nervous system plays an important role in sleep-onset insomnia. Weak vagal modulation and blunted baroreflex sensitivity were evident in this insomnia subtype, which indicates that difficulty in initiating sleep can independently affect morning cardiovascular function.

High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM) improves symptoms and autonomic function for insomnia: A randomized, placebo-controlled clinical trial

INTRODUCTION

Effective insomnia interventions that also address autonomic dysregulation are lacking. We evaluate high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM® ), in a randomized, controlled clinical trial. HIRREM is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology, to support self-optimization of brain rhythms.

METHODS

One hundred and seven adults (mean age 45.7, SD ± 5.6, 73 women), with Insomnia Severity Index (ISI) scores of ≥15, received ten, 90-min sessions of HIRREM, with tones linked to brainwaves (LB, 56), or random tones not linked to brainwaves (NL, 51), as an active, sham placebo. Outcomes were obtained at enrollment (V1), 1-7 days (V2), 8-10 weeks (V3), and 16-18 weeks (V4) after intervention. Primary outcome was differential change in ISI from V1 to V3. Secondary measures assessed depression (BDI), anxiety (BAI), quality of life (EQ-5D), and a sleep diary. Ten minute recordings of HR and BP allowed analysis of heart rate variability (HRV) and baroreflex sensitivity (BRS).

RESULTS

Of 107 randomized, 101 completed the intervention. Intention-to-treat analysis (107) of change from V1 to V3 revealed a mean reduction of ISI in NL of -4.93 (SE ± 0.76) points, with additional, significant reduction of -2.05 points (0.74) in LB (total reduction of -6.98, p = .045). Additional reduction of -2.30 points (0.76) was still present in the LB at V4 (p = .058). Total ISI reduction from V1 to V4 was -5.90 points for NL and -7.93 points in LB. There were group differences (p < .05) for multiple HRV and BRS measures (rMSSD, SDNN, HF alpha, and Seq ALL), as well as total sleep time, sleep onset latency, and sleep efficiency. There were no serious adverse events.

CONCLUSIONS

Results of this controlled clinical trial showed clinically relevant reduction of insomnia symptoms with HIRREM, over, and above an active, sham control, with associated, durable improvement in autonomic cardiovascular regulation.

Short-term efficacy of home-based heart rate variability biofeedback on sleep disturbance in patients with incurable cancer: a randomised open-label study

OBJECTIVES

Early palliative care reportedly contributes to the quality of life by improving coping skills in patients with cancer. The aims of the study are to (1) Build a self-coping system that makes it possible to perform a session of home-based heart rate variability biofeedback (HRV-BF) with resonant breathing in patients with sleep disturbance and to acquire its techniques early on, and (2) Examine its short-term efficacy and feasibility.

METHODS

A randomised, open-label, comparative study was conducted in the presence or absence of home-based HRV-BF with resonant breathing using a portable HRV-BF device prior to bedtime. The participants were 50 patients with incurable cancer with sleep disturbance who underwent a hospital practice of HRV-BF with resonant breathing. The primary end point was the rate of change in sleep efficiency for 10-14 days. The Japanese version of the Pittsburgh Sleep Quality Index (subjective indicator) and actigraphy sleep parameters (objective indicators) were used for sleep assessments.

RESULTS

The completion rate and implementation rate in the home-based HRV-BF group (n=25) were 96.0% and 91.4%, respectively. This group showed a significant improvement in sleep efficiency, sleep duration and the low-frequency component of HRV. Sleep latency worsened in this group, but a significant difference was not observed.

CONCLUSIONS

A home practice of HRV-BF with resonant breathing made it possible to acquire its techniques early on and improve sleep and autonomic function; therefore, our study showed high short-term efficacy and feasibility required for a self-coping system.

Protocol for the impact of CBT for insomnia on pain symptoms and central sensitisation in fibromyalgia: a randomised controlled trial

INTRODUCTION

Approximately 50% of individuals with fibromyalgia (a chronic widespread pain condition) have comorbid insomnia. Treatment for these comorbid cases typically target pain, but growing research supports direct interventions for insomnia (eg, cognitive behavioural treatment for insomnia (CBT-I)) in these patients. Previous research suggests sustained hyperarousal mediated by a neural central sensitisation mechanism may underlie insomnia and chronic pain symptoms in fibromyalgia. We hypothesise CBT-I will improve insomnia symptoms, improve clinical pain and reduce central sensitisation. The trial will be the first to evaluate the short-term and long-term neural mechanisms underlying insomnia and pain improvements in fibromyalgia. Knowledge obtained from this trial might allow us to develop new or modify current treatments to better target pain mechanisms, perhaps reversing chronic pain or preventing it.

METHODS AND ANALYSIS

Female participants (n=130) 18 years of age and older with comorbid fibromyalgia (with pain severity of at least 50/100) and insomnia will be recruited from the University of Missouri in Columbia, Missouri, and surrounding areas. Participants will be randomised to 8 weeks (plus 4 bimonthly booster sessions) of CBT-I or a sleep hygiene control group (SH). Participants will be assessed at baseline, post-treatment, 6 and 12 months follow-ups. The following assessments will be completed: 2 weeks of daily diaries measuring sleep and pain, daily actigraphy, insomnia severity index, pain-related disability, single night of polysomnography recording, arousal (heart rate variability, cognitive affective arousal), structural and functional MRI to examine pain-related neural activity and plasticity and mood (depression, anxiety).

ETHICS AND DISSEMINATION

Ethics approval was obtained in July 2018 from the University of Missouri. All data are expected to be collected by 2022. Full trial results are planned to be published by 2024. Secondary analyses of baseline data will be subsequently published.

TRIAL REGISTRATION NUMBER

NCT03744156.

Effect of Sudarshan Kriya Yoga (SKY) on daytime and situational sleep propensity in novice practitioners: a prospective cohort study

OBJECTIVES

Hectic, late-night lifestyle has reduced 90 min sleep in 20% adults resulting in insomnia and excessive daytime sleepiness (EDS). We assess the scope of Sudarshan Kriya Yoga (SKY), a 4-component, breathing process in reducing EDS, generally and situationally.

METHODS

This is a prospective, controlled study involving randomized subjects without any sleep-wake cycle anomalies and prior experience in SKY. Subjects (n=52) performed 30 min of SKY for 6 days/week for 8 weeks, while controls (n=53) performed sitting activity and Suryanamaskar for 4-weeks each. Epworth Sleepiness Scale (ESS) was used to measure EDS at 0, 4, and 8 weeks.

RESULTS

SKY group showed significant ESS score improvements between 0-4 weeks and 4-8 weeks of 1.22 (p=0.0001) and 1.66 (p=0.001) respectively. Controls however failed to improve with score differences of 0.02 (p=0.892) and 0.02 (p=0.8212) respectively. SKY group showed significant ESS score improvement over controls at 4-weeks (difference=1.74; p=0.013) and 8-weeks (difference eight; p=0.0001). Improvement was most for obese people and those sitting in a halted car.

CONCLUSIONS

Improvement in subjects' nighttime sleep and daytime wakefulness in SKY practitioners can be attributed to polyvagal theory. Increased heart rate variability (HRV) alterations and sympathetic hyperarousal in chronic insomnia; and cholinergic and GABAergic dysregulation in anxiety disorders are countered by regulated vagal nerve stimulation post SKY. Our study establishes effectivity of SKY in reducing EDS (total and situational), provides a clinical correlation for prior polysomnographic evidence and paves way for larger trials directed towards SKY prescriptions for insomnia.

Beyond the bladder: poor sleep in women with overactive bladder syndrome

BACKGROUND

Nocturnal bladder symptoms and sleep disruption commonly coexist in middle-aged and older women. Although sleep disruption is often attributed to nocturnal bladder symptoms in women with overactive bladder syndrome, nonbladder factors also may influence sleep in this population. Many women with overactive bladder are eager to identify nonpharmacologic strategies for both bladder symptoms and sleep disruption, given the potential adverse effects of sedative and anticholinergic bladder medications in this population.

OBJECTIVES

To provide greater insight into the complex relationship between nighttime overactive bladder symptoms and sleep disruption, and to evaluate the effects of a guided slow-paced respiration intervention on sleep outcomes in women with overactive bladder.

STUDY DESIGN

We conducted an ancillary study within a randomized trial of slow-paced respiration in women with overactive bladder symptoms. Ambulatory community-dwelling women who reported ≥3 episodes/day of urgency-associated voiding or incontinence were randomized to use either a portable biofeedback device (RESPeRATE; Intercure, Ltd) to practice guided slow-paced respiration exercises daily for 12 weeks (N=79) or an identical-appearing device programmed to play nonrhythmic music without guiding breathing (N=82). At baseline and after 12 weeks, bladder symptoms were assessed by voiding diary, sleep duration, and disruption were assessed by sleep diary corroborated by wrist actigraphy, and poor sleep quality was determined by a Pittsburgh Sleep Quality Index global score >5.

RESULTS

Of the 161 women randomized, 31% reported at least twice-nightly nocturia, 26% nocturnal incontinence, and 70% poor sleep quality at baseline. Of the 123 reporting any nighttime awakenings, 89% averaged 1 or more nighttime awakenings, and 83% attributed at least half of awakenings to using the bathroom. Self-reported wake time after sleep onset increased with increasing frequency of nocturnal bladder symptoms (P=.01 for linear trend). However, even among women without nocturia, average sleep quality was poor (Pittsburg Sleep Quality Index global score mean of 7.3; 95% confidence interval, 6.0-8.6). Over 12 weeks, women assigned to slow-paced respiration (N=79) experienced modest improvements in mean nocturnal voiding frequency (0.4 fewer voids/night), sleep quality (1.1 point score decrease), and sleep disruption (1.5% decreased wake time after sleep onset). However, similar improvements were detected in the music control group (N=81), without significant between-group differences.

CONCLUSIONS

Many women with overactive bladder syndrome experience disrupted sleep, but not all nocturnal awakenings are attributable to bladder symptoms, and average sleep quality tends to be poor even in women without nocturia. Findings suggest that clinicians should not assume that poor sleep in women with overactive bladder syndrome is primarily caused by nocturnal bladder symptoms. Guided slow-paced respiration was associated with modest improvements in nocturia frequency and sleep quality in this trial, but the results do not support clinician recommendation to use this technique over other behavioral relaxation techniques for improving sleep.

Major depressive disorder and insomnia: Exploring a hypothesis of a common neurological basis using waking and sleep-derived heart rate variability

It remains unclear whether neurobiological dysfunction observed in major depressive disorder (MDD) and insomnia is an expression of common or independent bases. The present investigation sought to explore differences in heart rate variability (HRV)-a widely utilized biomarker of neurobiological functioning-among individuals with MDD, insomnia, and healthy controls, while awake and during distinct sleep stages (REM, N2), with the goal of improving our understanding of shared neurobiological factors in depression and insomnia. Participants were 73 adults who underwent home polysomnography. All N2 and REM sleep epochs with a duration greater than or equal to 5 min were identified for HRV analysis. Additionally, a single waking epoch was defined for each participant. From waking to N2 sleep, and waking to REM sleep, changes in HRV indices indicated participants experienced reductions in sympathetic arousal and increases in parasympathetic arousal. Contrary to hypotheses, however, no between group differences were observed in HRV. Though the present findings do not support the hypotheses of a shard neurobiological pathway between MDD and insomnia, more work is warranted to advance our understanding of the neurobiological bases of these common, debilitating, and frequently co-occurring psychiatric conditions, to improve early detection and identify novel intervention targets for these disorders.

Effect of Heart Rate Variability Biofeedback Sessions With Resonant Frequency Breathing on Sleep: A Pilot Study Among Family Caregivers of Patients With Cancer

Heart rate variability biofeedback (HRV-BF) is used as a skill in psychosomatic medicine, but is not yet established in the field of sleep. The present study aimed to evaluate the effect of HRV-BF with resonant frequency breathing (RFB) on sleep performed once every 2 weeks and the usefulness of practice of RFB using a portable device at home before bedtime. Participants were 69 family caregivers of patients with cancer that felt burdened by nursing care. We conducted a randomized controlled trial with an HRV-BF+Home practice group and an HRV-BF group. HRV-BF with RFB was administered to both groups at our medical institution for up to 30 min on the experiment days. Home practice involved RFB using a portable device, which was performed at home each day within 20 min before bedtime. Evaluation items were: change ratio of total score of the Pittsburgh Sleep Quality Index (PSQI) at 28 days after the trial started. In total, 52.2% of participants had insomnia. The two HRV-BF groups had decreased PSQI total scores, which indicated an improvement in PSQI total score near 5.5 on Day 28. The two HRV-BF groups had significantly increased HRV scores on Day 28, and there was correlation between the variation of PSQI total score and the variation of HRV score. The quality of sleep assessed by PSQI scores in the HRV-BF+Home practice group was significantly improved compared with the HRV-BF group on Day 28 (p = 0.001). This suggests HRV-BF may be a useful skill for enhancing sleep among family caregivers of patients with cancer, as well as supporting their autonomic nervous function. Additional actual regular practice of RFB (using a portable device at home before bedtime) may further enhance the effect.

Heart rate variability and surgical pleth index under anesthesia in poor and normal sleepers

Poor sleep quality is associated with autonomic dysfunctions and altered pain perception and tolerance. To investigate whether autonomic dysregulations related to insomnia would still exist under general anesthesia, we adopt heart rate variability (HRV) analysis to evaluate ANS activity and surgical pleth index (SPI) to compare nociceptive/anti-nociceptive balance. We enrolled 61 adult females scheduled for gynecological surgeries under general anesthesia. All the subjects were ASA Class I to III without using medicines affecting HRV. We used the Insomnia Severity Index to evaluate sleep qualities. ECG data were recorded and signals which denote four different surgical stages were extracted (baseline, incision, mid-surgery, and end of surgery). We analyzed the HRV changes across the whole surgical period and differences among good and poor sleepers. We also compared the SPI differences among groups. For baseline HRV analysis, we found significant differences in the RMSSD (p = 0.043), pNN50 (p = 0.029), VLF power (p = 0.035), LF power (p = 0.004), and HF power (p = 0.037) between the good and poor sleeper groups. However, all intergroup differences disappeared after anesthesia induction. Temporal HRV changes significantly among different perioperative stages (RMSSD, p < 0.001; pNN50, p = 0.004; LF, p < 0.001; and HF, p < 0.001). Patients with different sleep qualities did not exhibit different SPI levels in all four periods. Poor sleepers exhibited attenuated parasympathetic activities at the baseline but no differences after the induction. Nociceptive/anti-nociceptive balance seems not be altered by poor sleep condition under general anesthesia.

Assessment of sympathetic neural activity in chronic insomnia: evidence for elevated cardiovascular risk

Study Objectives

Chronic insomnia affects up to 15 per cent of adults. Recent cross-sectional and prospective epidemiological studies report an association between insomnia and hypertension, including incident hypertension, yet mechanisms underlying the association remain unknown. We hypothesized that participants with chronic insomnia would have elevated sympathetic neural outflow, blunted baroreflex sensitivity, and augmented sympathetic neural and cardiovascular reactivity to stress when compared with good-sleeper controls.

Methods

Twelve participants with chronic insomnia (11 women, 1 man) and 12 controls (8 women, 4 men) underwent one night of laboratory polysomnography, two weeks of at-home wrist actigraphy, and one night of controlled laboratory sleep prior to a comprehensive morning autonomic function test. The autonomic function test consisted of simultaneous recordings of muscle sympathetic nerve activity (MSNA; microneurography), beat-to-beat blood pressure (finger plethysmography), and heart rate (electrocardiogram) during a 10 min supine baseline and a 2 min cold pressor test.

Results

Baseline blood pressure, heart rate, and MSNA were not different between groups, but sympathetic baroreflex sensitivity was significantly blunted in participants with insomnia (-2.1 ± 1.0 vs. -4.3 ± 1.3 bursts/100 heartbeats/mm Hg; p < 0.001). During the cold pressor test, systolic arterial pressure reactivity (Δ21 ± 11 vs. Δ14 ± 8 mm Hg; time × group = 0.04) and total MSNA reactivity (Δ127%, 54%-208% vs. Δ52%, 30%-81%; time × group = 0.02) were augmented in chronic insomnia.

Conclusions

Participants with chronic insomnia demonstrated impaired sympathetic baroreflex function and augmented neural cardiovascular responsiveness to stress, when compared with controls. These findings support growing evidence of cardiovascular risk and physiological hyperarousal in chronic insomnia.

Clinical Trial Registration

NCT02048878. https://clinicaltrials.gov/ct2/show/NCT02048878.

Reducing bedtime physiological arousal levels using immersive audio-visual respiratory bio-feedback: a pilot study in women with insomnia symptoms

Hyperarousal is a critical component of insomnia, particularly at bedtime when individuals are trying to fall asleep. The current study evaluated the effect of a novel, acute behavioral experimental manipulation (combined immersive audio-visual relaxation and biofeedback) in reducing bedtime physiological hyperarousal in women with insomnia symptoms. After a clinical/adaptation polysomnographic (PSG) night, sixteen women with insomnia symptoms had two random-order PSG nights: immersive audio-visual respiratory bio-feedback across the falling asleep period (manipulation night), and no pre-sleep arousal manipulation (control night). While using immersive audio-visual respiratory bio-feedback, overall heart rate variability was increased and heart rate (HR) was reduced (by ~ 5 bpm; p < 0.01), reflecting downregulation of autonomic pre-sleep arousal, relative to no-manipulation. HR continued to be lower during sleep, and participants had fewer awakenings and sleep stage transitions on the manipulation night relative to the control night (p < 0.05). The manipulation did not affect sleep onset latency or other PSG parameters. Overall, this novel behavioral approach targeting the falling asleep process emphasizes the importance of pre-sleep hyperarousal as a potential target for improving sleep and nocturnal autonomic function during sleep in insomnia.

High-Frequency Heart Rate Variability Reactivity and Trait Worry Interact to Predict the Development of Sleep Disturbances in Response to a Naturalistic Stressor

BACKGROUND

High-frequency heart rate variability (HF-HRV) reactivity was proposed as a vulnerability factor for stress-induced sleep disturbances. Its effect may be amplified among individuals with high trait worry or sleep reactivity.

PURPOSE

This study evaluated whether HF-HRV reactivity to a worry induction, sleep reactivity, and trait worry predict increases in sleep disturbances in response to academic stress, a naturalistic stressor.

METHOD

A longitudinal study following 102 undergraduate students during an academic semester with well-defined periods of lower and higher academic stress was conducted. HF-HRV reactivity to a worry induction, trait worry using the Penn State Worry Questionnaire, and sleep reactivity using the Ford Insomnia Stress Reactivity Test were measured during the low stress period. Sleep disturbances using the Pittsburgh Sleep Quality Index were assessed twice during the lower stress period and three times during the higher stress period.

RESULTS

Greater reductions in HF-HRV in response to the worry induction predicted increases in sleep disturbances from the lower to the higher academic stress period. Trait worry moderated this association: individuals with both higher trait worry and greater HF-HRV reactivity to worry had larger increases in stress-related sleep disturbances over time, compared to participants with lower trait worry and HF-HRV reactivity. A similar, but marginally significant effect was found for sleep reactivity.

CONCLUSION

This study supports the role of HF-HRV reactivity as a vulnerability factor for stress-induced sleep disturbances. The combination of high trait worry and high HF-HRV reactivity to worry might identify a subgroup of individuals most vulnerable to stress-related sleep disturbances.

Self-Regulation of Breathing as an Adjunctive Treatment of Insomnia

Sleep is a quiescent behavioral state during which complex homeostatic functions essential to health and well-being occur. Insomnia is a very common psychiatric disorder leading to a myriad of detrimental effects including loss of concentration, memory, and performance as well as disease. Current pharmaceutical treatments can be expensive, impairing, unhealthy, and habit-forming. Relaxation techniques, such as meditation target the brain and body in contrast to pharmaceutical interventions which solely target neurotransmitter systems in the brain. In this article we present a viewpoint on the treatment of insomnia that techniques of slow, deep breathing (0.1 Hz) in adjunct to sleep hygiene and relaxation therapies may be highly effective in initiating sleep as well as facilitating falling back asleep. The autonomic nervous system is integral to sleep initiation, maintenance, and disruption. Understanding the relationship between the autonomic nervous system and sleep physiology along with the nature of sleep itself remains a challenge to modern science. We present this perspective in light of a prevailing "dysevolution" theory on the pathology of insomnia that proposes hyper-arousal characterized in part by chronic sympathetic hyperactivation and/or parasympathetic hypoactivation disrupts normal sleep onset latency, sleep quality, and sleep duration. We additionally discuss physiological mechanisms responsible for the effectiveness of the breathing treatment we describe. A better understanding of these mechanisms and autonomic pathologies of insomnia may provide support for the effectiveness of such techniques and provide relief to sufferers of this health epidemic.

Concussion and the autonomic nervous system: An introduction to the field and the results of a systematic review

BACKGROUND

Recent evidence suggests that autonomic nervous dysfunction may be one of many potential factors contributing to persisting post-concussion symptoms.

OBJECTIVE

This is the first systematic review to explore the impact of concussion on multiple aspects of autonomic nervous system functioning.

METHODS

The methods employed are in compliance with the American Academy of Neurology (AAN) and PRISMA standards. Embase, MEDLINE, PsychINFO, and Science Citation Index literature searches were performed using relevant indexing terms for articles published prior to the end of December 2016. Data extraction was performed by two independent groups, including study quality indicators to determine potential risk for bias according to the 4-tiered classification scheme of the AAN.

RESULTS

Thirty-six articles qualified for inclusion in the analysis. Only three studies (one Class II and two Class IV) did not identify anomalies in measures of ANS functioning in concussed populations.

CONCLUSIONS

The evidence supports the conclusion that it is likely that concussion causes autonomic nervous system anomalies. An awareness of this relationship increases our understanding of the physical impact of concussion, partially explains the overlap of concussion symptoms with other medical conditions, presents opportunities for further research, and has the potential to powerfully inform treatment decisions.

Usefulness of psychoeducational intervention in chronic insomnia: an actigraphic study

Background: Chronic Insomnia is a severe and disabling condition characterized by difficulty in initiating or maintaining sleep, waking up too early, despite adequate opportunity and circumstances for sleep. Maladaptive thoughts and dysfunctional beliefs about sleep are considered crucial factors in developing and perpetuating this disorder.Aims: The aim of the study was to explore the usefulness, in patients with chronic insomnia, of a one-session psychoeducational intervention on sleep-related maladaptive thoughts and beliefs, and on sleep perception.Methods: Thirty-eight patients with chronic insomnia were enrolled in the study and randomly assigned to receive psychoeducational intervention (PI+) or to act as controls (PI-). Patients wore an actigraph and compiled a sleep diary for 14 d. After the first 7 d, only PI+ patients received one session of psychoeducational intervention.Results: A significant reduction of sleep related preoccupations, a reduction of dysfunctional beliefs about sleep, and an improvement of subjective perception of sleep were observed in the PI+ group, but not in the PI- group. No significant modification was observed for objective total sleep time.Conclusions: Our results suggest that one-session psychoeducational intervention is associated with a decrease of sleep-related maladaptive thoughts and beliefs, and with an improvement on subjective sleep perception.

Measures of cardiovascular autonomic activity in insomnia disorder: A systematic review

BACKGROUND

Insomnia disorder is a widespread sleep disorder with a prevalence of approximately 10%. Even though the link between insomnia and cardiovascular activity is not exactly clear, it is generally assumed that cardiovascular autonomic modifications could occur as a result of sleeplessness, or, alternatively, that autonomic alterations could be an expression of a hyper-arousal state. This review investigates whether cardiovascular measures are different between insomniacs and controls.

METHODS

Electronic databases were systematically searched, and 34 studies were identified. Heart rate variability features, the association of cardiac and EEG activity, physiologic complexity measures, and cardiovascular activity, assessed by measures such as pre-ejection time, blood pressure, and heart rate dynamics were studied. Given the heterogeneity of the studies, a narrative synthesis of the findings was performed.

RESULTS

This review study found overall differences in cardiovascular activity between insomniacs and controls in most of the observational studies (21/26), while the expression of cardiovascular regulation varied between the examined insomniac groups. All the studies that investigated the association of cardiac activity and EEG power reported an altered relation between autonomic activity and EEG parameters in insomniacs.

CONCLUSION

Autonomic regulation tends to be consistent between insomniacs, as long as they are grouped according to their respective phenotype, as shown in the insomnia subgroup with objectively short sleep duration. Our hypothesis is that these differences in the expression of cardiovascular activity could be explained by the heterogeneity of the disorder. Therefore, the determination of insomnia phenotypes, and the study of cardiovascular measures, rather than heart rate variability alone, will give more insight into the link between insomnia and cardiovascular regulation. This study suggests that cardiovascular activity differs between insomniacs and controls. These new findings are of interest to clinicians and researchers for a more accurate insomnia assessment, and the development of personalized technological solutions in insomnia.

Investigating psychological and physiological responses to the Trier Social Stress Test in young adults with insomnia

OBJECTIVE

Stress and hyperarousal both contribute to insomnia. Elevated stress-related sleep reactivity is associated with hyperarousal, and might constitute a vulnerability to future insomnia. The present study examined acute stress-induced arousal and its association with nocturnal sleep.

METHODS

Participants were 30 healthy adults (66.7% female, M_age = 26.7 years): 10 with insomnia (INS) and 20 good sleepers with high vulnerability (HV) or low vulnerability (LV) to insomnia. They underwent two consecutive nights of polysomnography. During the evening preceding the second night, the Trier Social Stress Test (TSST) was administered, and psychological and physiological arousal indices were assessed.

RESULTS

The TSST elicited an increase in psychological and physiological arousal in all three groups. The INS group showed greater acute cortisol response (p < 0.05) and secretion at bedtime (p < 0.05), and higher pre-sleep cognitive arousal (p < 0.01) than the LV group; HV participants did not significantly differ from those in the INS or the LV group. Increased cortisol response and elevated sympathovagal imbalance (ie, low frequency/high frequency ratio) were each significantly associated with longer nocturnal awakenings (p = 0.048, p = 0.037, respectively). Heightened blood pressure was significantly associated with prolonged sleep onset latency, and reduced total sleep time and sleep efficiency (all ps < 0.05).

CONCLUSIONS

These findings support the hyperarousal conceptualization of insomnia and indirectly suggest that increased stress reactivity and bedtime hyperarousal might represent a trait-like vulnerability in certain good sleepers. More research is warranted to validate and expand these preliminary findings.