Effects of mental relaxation and slow breathing in essential hypertension

Remote Short Sessions of Heart Rate Variability Biofeedback Monitored With Wearable Technology: Open-Label Prospective Feasibility Study

BACKGROUND

Heart rate variability (HRV) biofeedback is often performed with structured education, laboratory-based assessments, and practice sessions. It has been shown to improve psychological and physiological function across populations. However, a means to remotely use and monitor this approach would allow for wider use of this technique. Advancements in wearable and digital technology present an opportunity for the widespread application of this approach.

OBJECTIVE

The primary aim of the study was to determine the feasibility of fully remote, self-administered short sessions of HRV-directed biofeedback in a diverse population of health care workers (HCWs). The secondary aim was to determine whether a fully remote, HRV-directed biofeedback intervention significantly alters longitudinal HRV over the intervention period, as monitored by wearable devices. The tertiary aim was to estimate the impact of this intervention on metrics of psychological well-being.

METHODS

To determine whether remotely implemented short sessions of HRV biofeedback can improve autonomic metrics and psychological well-being, we enrolled HCWs across 7 hospitals in New York City in the United States. They downloaded our study app, watched brief educational videos about HRV biofeedback, and used a well-studied HRV biofeedback program remotely through their smartphone. HRV biofeedback sessions were used for 5 minutes per day for 5 weeks. HCWs were then followed for 12 weeks after the intervention period. Psychological measures were obtained over the study period, and they wore an Apple Watch for at least 7 weeks to monitor the circadian features of HRV.

RESULTS

In total, 127 HCWs were enrolled in the study. Overall, only 21 (16.5%) were at least 50% compliant with the HRV biofeedback intervention, representing a small portion of the total sample. This demonstrates that this study design does not feasibly result in adequate rates of compliance with the intervention. Numerical improvement in psychological metrics was observed over the 17-week study period, although it did not reach statistical significance (all P>.05). Using a mixed effect cosinor model, the mean midline-estimating statistic of rhythm (MESOR) of the circadian pattern of the SD of the interbeat interval of normal sinus beats (SDNN), an HRV metric, was observed to increase over the first 4 weeks of the biofeedback intervention in HCWs who were at least 50% compliant.

CONCLUSIONS

In conclusion, we found that using brief remote HRV biofeedback sessions and monitoring its physiological effect using wearable devices, in the manner that the study was conducted, was not feasible. This is considering the low compliance rates with the study intervention. We found that remote short sessions of HRV biofeedback demonstrate potential promise in improving autonomic nervous function and warrant further study. Wearable devices can monitor the physiological effects of psychological interventions.

Mindful breathing as an effective technique in the management of hypertension

Introduction: Hypertension is one of the most important, modifiable risk factors for cardiovascular disease. The popularity of wearable devices provides an opportunity to test whether device guided slow mindful breathing may serve as a non-pharmacological treatment in the management of hypertension. Methods: Fitbit Versa-3 and Sense devices were used for this study. In addition, participants were required to own an FDA or Health Canada approved blood pressure measuring device. Advertisements were shown to 655,910 Fitbit users, of which 7,365 individuals expressed interest and filled out the initial survey. A total of 1,918 participants entered their blood pressure readings on at least 1 day and were considered enrolled in the study. Participants were instructed to download a guided mindful breathing app on their smartwatch device, and to engage with the app once a day prior to sleep. Participants measured their systolic and diastolic blood pressure prior to starting each mindful breathing session, and again after completion. All measurements were self reported. Participants were located in the United States or Canada. Results: Values of systolic and diastolic blood pressure were reduced following mindful breathing. There was also a decrease in resting systolic and diastolic measurements when measured over several days. For participants with a systolic pressure ≥ 130 mmHg, there was a decrease of 9.7 mmHg following 15 min of mindful breathing at 6 breaths per minute. When measured over several days, the resting systolic pressure decreased by an average of 4.3 mmHg. Discussion: Mindful breathing for 15 min a day, at a rate of 6 breaths per minute is effective in lowering blood pressure, and has both an immediate, and a short term effect (over several days). This large scale study demonstrates that device guided mindful breathing with a consumer wearable for 15 min a day is effective in lowering blood pressure, and a helpful complement to the standard of care.

Effects of slow breathing training on hemodynamic changes, cardiac autonomic function and neuroendocrine response in people with high blood pressure: A randomized control trial

BACKGROUND

High blood pressure (BP) is a non-communicable disease that is a risk factor for cardiovascular disease and is the leading cause of mortality and morbidity worldwide. High BP can be managed by both pharmacological and non-pharmacological interventions. Non-pharmacological treatment, such as slow-breathing training (SBT), has been shown to reduce BP. However, there are few studies on the effect of SBT on both cardiac activation and oxidative stress in people with high BP.

OBJECTIVES

To explore the effect of SBT on cardiac autonomic function (i.e., heart rate variability: HRV) and neuroendocrine response (i.e., salivary cortisol).

METHODS

One hundred people (including 89 women) with high BP were randomly assigned to either a control (n = 50) or intervention group (n = 50). The intervention program was conducted for 30 min per day, for 5 days per week, for 4 weeks, with a total of 20 sessions of the SBT at the rate of 10 times per minute, whereas the control group was required to continue with their daily routine. HRV, BP, and salivary cortisol were measured before and after the intervention program. A two-way mixed ANOVA was performed for within-group and between-group comparisons over time.

RESULTS

Of the 100 participants, 71 individuals completed the study. The participants in the intervention group had a lower BP and salivary cortisol levels compared to those in the control group (p < .05). Further, those participants showed an increase in the standard deviation of normal R-R intervals after the 4-week intervention program (p < .05).

CONCLUSION

This study provided evidence demonstrating the effect of SBT on cardiac autonomic and stress reactivity, which has important implications for health promotion in people with high BP.

CLINICAL TRIAL REGISTRATION NUMBER

TCTR20180302008.

Efficacy of New Mindfulness-Based Swinging Technique Intervention: A Pilot Randomised Controlled Trial Among Women With Breast Cancer

Objective

Combining 3rd-wave-therapies with Cognitive-Behavioural-Therapy (CBT) has increased in recent years. Usually these therapies require longer sessions which therefore increases the psychotherapy drop-out rate for cancer patients for multiple medical reasons. This inspired intervention of a shorter 20 min-long mindfulness-therapy (MBST) to be developed for Breast-Cancer-patients (BC).

Method

This pilot randomised controlled trial was to assess the immediate-outcome of the MBST-intervention for its efficacy for BC-patients by using the Pearson Chi-square test, Fisher-Freeman-Halton exact test, and McNemar test for categorical variables; Mann-Whitney U and Wilcoxon test for the continuous variables. The Emotion Thermometer, State Trait Anxiety Inventory, Hospital Anxiety and Depression Scale, Self-Efficacy for Managing Chronic Disease, and Beck's Hopelessness Scale were used for measuring the intervention outcomes. One hundred seventy-three BC patients were randomly assigned in two-groups (equal-mean-age, p = 0.417). Control-Group (CG, n = 82) received cognitive-disputation-technique a form-of-CBT, and Intervention-Group (IG, n = 74) received MBST. The directives are given to IG: psychoeducation about Mindfulness, and to imagine themselves swinging-in a peaceful environment. When the patients imagine their swing going up, they physically take a deep-breath, and when going down they physically release their breath, and this process is repeated.

Result

Outcomes post-treatment showed significant higher-improvement in IG in all the assessed-measurements, with large-effect-size: anxiety (p < 0,05, r = 0,67) and depression-levels (p < 0,05, r = 0,71); anxiety-trait (p < 0,05; r = 0,79) reduced, it increases self-efficacy for managing-disease (p < 0,05, r = 0,82) as-well-as hopefulness (p < 0,05, r = 0,61) and saturation-level measured by pulse-meter/oximeter (p < 0,05, r = 0,51).

Conclusion

MBST is an efficacious intervention to reduce psychotherapy session time for immediate relief from clinical anxiety and hopelessness as well as increase self-efficacy and improve tranquillity for BC-women. It may have a particular clinical significance for supporting patient's adherence to treatment. Although in this pilot sample MBST was found to be effective for short-term-outcome, its efficacy for longer-term-outcome should be examined in future trials. Additionally, breathing laps can be increased possibly for a greater result on rise of saturation levels of patients.

Breathing Exercises for Improving Cognitive Function in Patients with Stroke

Patients with stroke may experience a certain degree of cognitive decline during the period of recovery, and a considerable number of such patients have been reported to show permanent cognitive damage. Therefore, the period of recovery and rehabilitation following stroke is critical for rapid cognitive functional improvements. As dysfunctional breathing has been reported as one of the factors affecting the quality of life post stroke, a number of studies have focused on the need for improving the breathing function in these patients. Numerous breathing exercises have been reported to enhance the respiratory, pulmonary, cognitive, and psychological functions. However, scientific evidence on the underlying mechanisms by which these exercises improve cognitive function is scattered at best. Therefore, it has been difficult to establish a protocol of breathing exercises for patients with stroke. In this review, we summarize the psychological, vascular, sleep-related, and biochemical factors influencing cognition in patients and highlight the need for breathing exercises based on existing studies. Breathing exercises are expected to contribute to improvements in cognitive function in stroke based on a diverse array of supporting evidence. With relevant follow-up studies, a protocol of breathing exercises can be developed for improving the cognitive function in patients with stroke.

Assessing the Effects of Nature on Physiological States Using Wearable Technologies

Nature therapy and forest bathing (FB) have been shown to have quantifiable positive effects on human health, but the physiological effects of a guided interactive nature activity remain unexplored. Autonomic nervous system responses to a guided nature walk (Nature Break) were assessed through the continuous measurement of the electrodermal activity (EDA), fingertip temperature, and heart rate (HR) of n = 48 participants, using a wearable sensor. Psychological distress was assessed before and after the activity using the Profile of Mood States (POMS) for n = 38 (24 females, 14 males, mean age = 43.55 ± 11.61 years) participants. The negative dimensions of POMS decreased and the positive (vigor) dimensions increased following a Nature Break. Significant differences were found across all of the physiological features, with some differences occurring between the morning and afternoon groups and between different days. The participants' mean HR decreased throughout the Nature Break. Our results suggest that interactive nature activities have positive psychological benefits and demonstrate the feasibility of using wearable sensors to monitor physiological responses in a naturalistic forest bathing activity.

Effectiveness of aromatherapy with inhaled lavender essential oil and breathing exercises on ECT-related anxiety in depressed patients

Background and aims Electroconvulsive therapy (ECT) is considered a safe, effective, and significant treatment in patients suffering from a major depressive disorder. Anxiety caused by this invasive treatment may impose several side effects on patients. The purpose of this study was to evaluate the effectiveness of aromatherapy with inhaled lavender essential oil and breathing exercises on ECT-related anxiety in depressed patients. Methods In this randomized controlled clinical trial, 90 depressed patients were selected and divided into three groups: aromatherapy, breathing exercise, and routine care using a random allocation method. Before undergoing ECT, the aromatherapy group was exposed to the inhaled lavender essential oil (n = 30), the breathing exercise group performed the breathing exercises (n = 30), and the routine care group received routine care (n = 30). Before (20 min) and after the intervention (30 min later), patients' anxiety was assessed using Beck Anxiety Inventory. Results After the intervention, the results revealed that anxiety score changes were statistically significant among the three groups (p < 0.001). In addition, it was found that the patients' mean anxiety scores significantly decreased in the aromatherapy and breathing exercise groups compared to with the pre-intervention scores (p < 0.001). Conclusion Aromatherapy with inhaled lavender essential oil and breathing exercises can be considered by clinical nurses as simple, applicable, and effective interventions to reduce ECT-related anxiety in depressed patients.

Altered Cardiovascular Reactivity to and Recovery from Cold Face Test-Induced Parasympathetic Stimulation in Essential Hypertension

Essential hypertension is associated with increased sympathetic and diminished parasympathetic activity as well as impaired reactivity to sympathetic stimulation. However, reactivity and recovery from parasympathetic stimulation in hypertension are unknown. We investigated reactivity and recovery to primarily parasympathetic stimulation by Cold Face Test (CFT) in essential hypertension. Moreover, we tested whether chronic stress modulates CFT-reactivity dependent on hypertension status. The CFT was conducted by applying a cold face-mask for 2 min in 24 unmedicated, otherwise healthy hypertensive men and in 24 normotensive controls. Systolic and diastolic blood pressure (BP) and heart rate (HR) were measured repeatedly. Chronic stress was assessed with the Trier-Inventory-for-Chronic-Stress-Screening-Scale. Hypertensives did not exhibit diastolic BP decreases after CFT-cessation (p = 0.59) as did normotensives (p = 0.002) and failed to show HR decreases in immediate response to CFT (p = 0.62) when compared to normotensives (p < 0.001). Systolic BP reactivity and recovery patterns did not differ between hypertensives and normotensives (p = 0.44). Chronic stress moderated HR (p = 0.045) but not BP CFT-reactivity (p's > 0.64) with chronically stressed normotensives showing similar HR reactivity as hypertensives. Our findings indicate impaired diastolic BP and HR reactivity to and recovery from CFT in hypertensives and a moderating effect of chronic stress on HR reactivity potentially reflecting reduced relaxation ability of the cardiovascular system.

Effects of mindful breath awareness and muscle relaxation and transcranial electrical stimulation techniques on improving blood pressure status in patients with type 2 diabetes

OBJECTIVE

The present study aimed to determine the effects of mindful breath awareness & muscle relaxation (MBMR) and transcranial electrical stimulation (tCES) techniques on improving the systolic and diastolic blood pressure status in patients with type 2 diabetes.

METHODS

The research method was randomized controlled trial (RCT) using split-plot ANOVA (SPANOVA). Thirty patients were selected through purposive sampling from Bonab County Diabetes Association (Iran) and were randomly divided into three 10-member groups, namely MBMR, tCES, and MBMR+tCES groups. Participants received their group interventions in 10 individual sessions. All patients were evaluated for systolic and diastolic blood pressure at two stages, before and immediately after each session. SPANOVA and Bonferroni pairwise comparison tests were used for data analysis.

RESULTS

The results indicated that the MBMR and tCES techniques, alone and in combination, had significant and equal effects on reducing diastolic blood pressure, but the MBMR treatment was more effective in the systolic blood pressure than the tCES.

CONCLUSIONS

The MBMR and tCES techniques were effective and safe in treating hypertension in patients with type 2 diabetes.

Non-invasive quantification of the effect of device-guided slow breathing with direct feedback to the patient to reduce blood pressure

OBJECTIVE

Slow breathing is a relaxation exercise recommended for lowering blood pressure (BP). Biofeedback may improve patient adherence and enhance BP lowering effects. Since the pulse arrival time (PAT) is inversely proportional to BP, it can be used to estimate BP changes.

APPROACH

In this pilot study, 30 patients (age 62.9 (SD 7.7) years, 11 F/19 M, Sys. BP 133.0 (SD 17.1) mmHg, Dia. BP 83.8 (SD 10.6) mmHg) performed a device-guided slow breathing exercise. PAT was measured by ECG and plethysmography and immediately presented to the patient, and respiratory sinus arrhythmia (RSA) was calculated retrospectively to measure the adherence to the instructed respiratory rate.

MAIN RESULTS

Respiratory rate was 13.6 (SD 1.9) bpm at baseline and 5.4 (SD 1.0) bpm during guided breathing. PAT continuously and progressively increased from 231.5 (SD 20.3) to 237.3 (SD 18.5) ms (p [Formula: see text] 0.001). The median deviation of RSA from the guided respiratory rate was 0.06 (IQR 0.19) bpm. In three patients, a deviation of > 0.20 bpm was detected, and two of them showed no increase in PAT. In total, 25 patients responded with increase in PAT.

SIGNIFICANCE

In this pilot study we have shown that biofeedback of PAT and RSA are feasible and can further improve motivation and adherence. Furthermore, we have shown that the exercise increased PAT, which indicates a reduction in BP. Due to its ease of use, this method is ideal for home use and self-monitoring.

Immediate effects of a single session of physical exercise on cognition and cerebral blood flow: A randomized controlled study of older adults

BACKGROUND

Regular physical activity is beneficial for cognitive performance in older age. A single bout of aerobic physical exercise can transiently improve cognitive performance. Researchers have advanced improvements in cerebral circulation as a mediator of long-term effects of aerobic physical exercise on cognition, but the immediate effects of exercise on cognition and cerebral perfusion are not well characterized and the effects in older adults are largely unknown.

METHODS

Forty-nine older adults were randomized to a 30-min aerobic exercise at moderate intensity or relaxation. Groups were matched on age and cardiovascular fitness (VO2 max). Average Grey Matter Blood Flow (GMBF), measured by a pulsed arterial-spin labeling (pASL) magnetic resonance imaging (MRI) acquisition, and working memory performance, measured by figurative n-back tasks with increasing loads were assessed before and 7 min after exercising/resting.

RESULTS

Accuracy on the n-back task increased from before to after exercising/resting regardless of the type of activity. GMBF decreased after exercise, relative to the control (resting) group. In the exercise group, higher n-back performance after exercise was associated with lower GMBF in the right hippocampus, left medial frontal cortex and right orbitofrontal cortex, and higher cardiovascular fitness was associated with lower GMBF.

CONCLUSION

The decrease of GMBF reported in younger adults shortly after exercise also occurs in older adults and relates to cardiovascular fitness, potentially supporting the link between cardiovascular fitness and cerebrovascular reactivity in older age.

Chronic Obstructive Pulmonary Disease and Dysphagia: A Synergistic Review

Chronic obstructive pulmonary disease (COPD) is a leading global cause of death and disability. The literature has previously established clear physiological characteristics of COPD-related dysphagia (swallowing difficulties). However, COPD and dysphagia are both also intimately tied to breathing and contribute to a cascade of secondary physio-psycho-emotional sequalae, such as COPD exacerbation, anxiety, depression, increased economic burden, social isolation, and decreased quality of life. Further, the collective impact of these comorbidities may magnify disease impact, resulting in a downward spiral of well-being. Thus, the clinical relevance of COPD’s and dysphagia’s frequently occurring and overlapping sequelae cannot be overlooked, as the disease-related burden of both disorders is deeply rooted in the presence of concomitant physiological and psycho-emotional consequences. The current review explores the complex network of interactions between COPD, dysphagia, and their outcomes, framing this relationship within a mind-body-breath framework. Ultimately, we propose a model that more comprehensively captures the constellation of interrelated disease characteristics and consequences, highlighting a need for researchers and healthcare providers to consider disease impact more broadly in order to maximize treatment outcomes.

Hypothesis: Pulmonary Afferent Activity Patterns During Slow, Deep Breathing Contribute to the Neural Induction of Physiological Relaxation

Control of respiration provides a powerful voluntary portal to entrain and modulate central autonomic networks. Slowing and deepening breathing as a relaxation technique has shown promise in a variety of cardiorespiratory and stress-related disorders, but few studies have investigated the physiological mechanisms conferring its benefits. Recent evidence suggests that breathing at a frequency near 0.1 Hz (6 breaths per minute) promotes behavioral relaxation and baroreflex resonance effects that maximize heart rate variability. Breathing around this frequency appears to elicit resonant and coherent features in neuro-mechanical interactions that optimize physiological function. Here we explore the neurophysiology of slow, deep breathing and propose that coincident features of respiratory and baroreceptor afferent activity cycling at 0.1 Hz entrain central autonomic networks. An important role is assigned to the preferential recruitment of slowly-adapting pulmonary afferents (SARs) during prolonged inhalations. These afferents project to discrete areas in the brainstem within the nucleus of the solitary tract (NTS) and initiate inhibitory actions on downstream targets. Conversely, deep exhalations terminate SAR activity and activate arterial baroreceptors via increases in blood pressure to stimulate, through NTS projections, parasympathetic outflow to the heart. Reciprocal SAR and baroreceptor afferent-evoked actions combine to enhance sympathetic activity during inhalation and parasympathetic activity during exhalation, respectively. This leads to pronounced heart rate variability in phase with the respiratory cycle (respiratory sinus arrhythmia) and improved ventilation-perfusion matching. NTS relay neurons project extensively to areas of the central autonomic network to encode important features of the breathing pattern that may modulate anxiety, arousal, and attention. In our model, pronounced respiratory rhythms during slow, deep breathing also support expression of slow cortical rhythms to induce a functional state of alert relaxation, and, via nasal respiration-based actions on olfactory signaling, recruit hippocampal pathways to boost memory consolidation. Collectively, we assert that the neurophysiological processes recruited during slow, deep breathing enhance the cognitive and behavioral therapeutic outcomes obtained through various mind-body practices. Future studies are required to better understand the physio-behavioral processes involved, including in animal models that control for confounding factors such as expectancy biases.

Spontaneous and Stimulus-Evoked Respiratory Rate Elevation Corresponds to Development of Allodynia in Spinal Cord-Injured Rats

Respiratory complications frequently accompany spinal cord injury (SCI) and slowed breathing has been shown to mitigate pain sensitivity. It is possible that elevated respiratory rates (RRs) signal the emergence of chronic pain after SCI. We previously validated the use of remote electric field sensors to noninvasively track breathing in freely behaving rodents. Here, we examined spontaneous (resting) and stimulus-evoked RRs as potential indices of mechanical hypersensitivity following SCI. Adult male Long-Evans rats received a lower thoracic hemisection or contusion SCI, or sham surgery, and underwent weekly assessments of mechanical and thermal sensitivity using the von Frey and Hargreaves tests, respectively. Resting RRs were recorded with remote sensors prior to nociception assays as well as 1 day post-surgery. Evoked RRs were quantified weekly in response to at-level mechanical stimulation provided by a small brush at various stimulation speeds, including those corresponding to the distinct tuning properties of a sub-population of cutaneous afferents known as C-low threshold mechanoreceptors. SCI rats developed mechanical hypersensitivity, which peaked 2-3 weeks after SCI. Compared with at baseline, hemisection SCI rats showed significantly heightened resting RRs at 1 day and 7 days post-injury, and the latter predicted development of pain hypersensitivity. In contusion SCI rats, resting RR increases were less substantial but occurred at all weekly time-points. Increases in brush-evoked RR coincided with full expression of hypersensitivity at 14 (hemisection) or 21 (contusion) days after SCI, and these effects were restricted to the lowest brush speeds. Our results support the possibility that early changes in RR may convey pain information in rats.

Comparison of rest‐break interventions during a mentally demanding task

Research is scarce on ways to enhance the effect of rest breaks during mentally demanding tasks. The present study investigated the effectiveness of two rest-break interventions on well-being during an academic lecture. Sixty-six students (53 females, mean age 22.5 years) enrolled in two different university classes of 4-hr duration participated in the study. Two measures of well-being (fatigue and vigor) were assessed immediately before, after, and 20 minutes after the break. A control condition without a break as well as an unstructured break was compared with breaks either encompassing physical activity or a relaxation exercise. Compared with the nonbreak condition, the unstructured rest break led to an increase in vigor, the exercise break as well as the relaxation break both to an increase in vigor and a decrease in fatigue at 20-min post break. Compared with the unstructured break, exercise led to an (additional) increase in vigor and relaxation to an (additional) decrease in fatigue at 20-min post break. Thus, the effects of rest breaks during mentally demanding tasks can be enhanced by engaging in physical activity or relaxation exercises, with effects lasting at least as long as 20 min into the continuation of the task.

Increased Mental Well-Being and Reduced State Anxiety in Teachers After Participation in a Residential Yoga Program

BACKGROUND Reducing stress in the workplace improves mental health. Teaching is of social importance, but it may receive inadequate recognition and rewards. The present study compared mental well-being and state anxiety in primary school teachers who practiced 15 days of yoga in a residential setting with those who continued their usual routine. MATERIAL AND METHODS We enrolled 236 primary school teachers to participate in the study. We assigned 118 primary school teachers (group mean ±S.D., age 41.5±6.0 years, 74 females) to the experimental group; they underwent 15 days of yoga training for 6 hours/day) in a residential yoga center. The non-yoga control group (group mean ±S.D., age 42.3±6.0 years, 79 females) consisted of 118 teachers who continued with their normal teaching routine. RESULTS After 15 days in the residential yoga program, there was an increase in overall mental well-being (p<.001) and lower state anxiety (p<.01) (repeated-measures ANOVA, followed by post hoc multiple comparison tests). At baseline, the non-yoga control group had higher levels of state anxiety, presumably related to their remaining in the workplace. CONCLUSIONS The study was a 15-day, comparative, controlled trial. The results show that after 15 days of participation in the residential yoga program, primary school teachers increased all aspects of mental well-being and had reduced state anxiety.

Influence of Yoga on the Autonomic Nervous System

Increased interest in exploring the physiological benefits of yoga in last few decades resulted in plethora of scientific studies involving different physiological measures in healthy volunteers and patients with various disorders. Of these measures, autonomic functions assessment remained prime role because of wider regulation of autonomic nervous system functions over all visceral systems of the body. Through its two limbs (sympathetic and parasympathetic) autonomic nervous system regulates involuntary visceral organs and systems of the body, which is critical in maintaining the homeostasis of all the physiological functions. This homeostasis is altered in various disease conditions most of which resulted because of the increased stress, a product of modern day lifestyle. Yoga is perfect antidote for the stress, effectively tackling the dreaded effects of stress on physiological systems mainly acting through modulating sympathovagal balance to maintain the homeostasis and restoring the health. We will discuss how yoga achieves this balance in various disorders by reviewing the autonomic system, its functions, laboratory assessments and plenty of scientific studies conducted over last few decades in various disorders involving yoga and autonomic functions. Although we have general idea as to how yoga modulates the sympathovagal balance improving clinical condition, we need to have more long-term, in-depth, well-controlled studies not only to understand these complex interactions of yoga and autonomic functions but also to provide scientific credibility to yoga research in world's scientific community. These steps would hopefully enable mankind to lead the disease-free healthy life style effectively to achieve meaningfully the purpose of one's life.

Slow Breathing Can Be Operantly Conditioned in the Rat and May Reduce Sensitivity to Experimental Stressors

In humans, exercises involving slowed respiratory rate (SRR) counter autonomic sympathetic bias and reduce responses to stressors, including in individuals with various degrees of autonomic dysfunction. In the rat, we examined whether operant conditioning could lead to reductions in respiratory rate (RR) and performed preliminary studies to assess whether conditioned SRR was sufficient to decrease physiological and behavioral responsiveness to stressors. RR was continuously monitored during 20 2-h sessions using whole body plethysmography. SRR conditioned, but not yoked control rats, were able to turn off aversive visual stimulation (intermittent bright light) by slowing their breathing below a preset target of 80 breaths/min. SRR conditioned rats greatly increased the incidence of breaths below the target RR over training, with average resting RR decreasing from 92 to 81 breaths/min. These effects were significant as a group and vs. yoked controls. Preliminary studies in a subset of conditioned rats revealed behavioral changes suggestive of reduced reactivity to stressful and nociceptive stimuli. In these same rats, intermittent sessions without visual reinforcement and a post-training priming stressor (acute restraint) demonstrated that conditioned rats retained reduced RR vs. controls in the absence of conditioning. In conclusion, we present the first successful attempt to operantly condition reduced RR in an animal model. Although further studies are needed to clarify the physio-behavioral concomitants of slowed breathing, the developed model may aid subsequent neurophysiological inquiries on the role of slow breathing in stress reduction.

Meta-Analysis of Effects of Voluntary Slow Breathing Exercises for Control of Heart Rate and Blood Pressure in Patients With Cardiovascular Diseases

Rising heart rate (HR) and elevated blood pressure (BP) cause a greater frequency of cardiovascular events. Many patients cannot maintain target HR and BP using pharmacological therapies. To evaluate the effectiveness of voluntary slow breathing exercises in reducing resting HR and BP, we searched Embase (1974 to April 2016), PubMed (1966 to April 2016), the Cochrane Central Register of Controlled Trials (issue 4, April 2016), and PEDro (www.pedro.org.au; 1999 to April 2016). The primary outcome was the mean change in HR at rest. Secondary outcomes included changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) as well as compliance with the breathing training. Finally, we included 6 studies consisting of 269 subjects. Practice of the breathing exercises resulted in statistically significant HR reduction (mean difference: -1.72 beats/min, 95% CI -2.70 to -0.75). Reductions were seen in SBP (mean difference: -6.36 mm Hg, 95% CI -10.32 to -2.39) and DBP (mean difference: -6.39 mm Hg, 95% CI -7.30 to -5.49) compared with the controls. Trial durations ranged from 2 weeks to 6 months. In conclusion, the existing evidence from randomized controlled trails demonstrates that short-term voluntary slow breathing exercises can reduce resting HR, SBP, and DBP for patients with cardiovascular diseases.

A cross-sectional evaluation of meditation experience on electroencephalography data by artificial neural network and support vector machine classifiers

To quantitate the meditation experience is a subjective and complex issue because it is confounded by many factors such as emotional state, method of meditation, and personal physical condition. In this study, we propose a strategy with a cross-sectional analysis to evaluate the meditation experience with 2 artificial intelligence techniques: artificial neural network and support vector machine. Within this analysis system, 3 features of the electroencephalography alpha spectrum and variant normalizing scaling are manipulated as the evaluating variables for the detection of accuracy. Thereafter, by modulating the sliding window (the period of the analyzed data) and shifting interval of the window (the time interval to shift the analyzed data), the effect of immediate analysis for the 2 methods is compared. This analysis system is performed on 3 meditation groups, categorizing their meditation experiences in 10-year intervals from novice to junior and to senior. After an exhausted calculation and cross-validation across all variables, the high accuracy rate >98% is achievable under the criterion of 0.5-minute sliding window and 2 seconds shifting interval for both methods. In a word, the minimum analyzable data length is 0.5 minute and the minimum recognizable temporal resolution is 2 seconds in the decision of meditative classification. Our proposed classifier of the meditation experience promotes a rapid evaluation system to distinguish meditation experience and a beneficial utilization of artificial techniques for the big-data analysis.

Assessment of Sleep Quality and Effects of Relaxation Exercise on Sleep Quality in Patients Hospitalized in Internal Medicine Services in a University Hospital: The Effect of Relaxation Exercises in Patients Hospitalized

This study aims to assess sleep quality and determine the effects of relaxation exercise on sleep quality in patients hospitalized in internal medicine services. In total, 47 patients comprised the control group and did not engage in the exercise intervention--the progressive muscle relaxation exercise, whereas 235 patients were assigned to the intervention group (N = 282). In this study, Description Questionnaire Form and the Pittsburg Sleep Quality Index (PSQI) were used. Most patients (73.8%) had poor sleep quality. The mean pre- and postexercise PSQI scores of the patients in the interventional group were 8.7 ± 4.0 and 6.1 ± 3.3, respectively. The mean pre- and postexercise PSQI scores of the control patients were 6.6 ± 3.5 and 5.6 ± 2.7, respectively. According to this study, the exercises significantly enhanced the quality of sleep. Patients should be encouraged by nurses to perform relaxation exercises.

The effects of progressive muscular relaxation and breathing control technique on blood pressure during pregnancy

Background:

Hypertensive disorders in pregnancy are the main cause of maternal and fetal mortality; however, they have no definite effective treatment. The researchers aimed to study the effects of progressive muscular relaxation and breathing control technique on blood pressure (BP) during pregnancy.

Materials and Methods:

This three-group clinical trial was conducted in Mashhad health centers and governmental hospitals. Sixty pregnant (after 20 weeks of gestational age) women with systolic BP ≥ 135 mmHg or diastolic BP ≥ 85 mmHg were assigned to three groups. Progressive muscular relaxation and breathing control exercises were administered to the two experimental groups once a week in person and in the rest of the days by instructions given on a CD for 4 weeks. BP was checked before and after the interventions. BP was measured before and after 15 min subjects' waiting without any especial intervention in the control group.

Results:

After 4 weeks of intervention, the systolic (by a mean of 131.3 to 117.2, P = 0.001 and by a mean of 131.05 to 120.5, P = 0.004, respectively) and diastolic (by a mean of 79.2 to 72.3, P = 0.001 and by a mean of 80.1 to 76.5, P = 0.047, respectively) BPs were significantly decreased in progressive muscular relaxation and breathing control groups, but they were not statistically significant in the control group.

Conclusions:

The interventions were effective on decreasing systolic and diastolic BP to normal range after 4 weeks in both the groups. The effects of both the interventions were more obvious on systolic BP compared to diastolic BP.

Somnomat: a novel actuated bed to investigate the effect of vestibular stimulation

Rocking movements are known to affect human sleep. Previous studies have demonstrated that the transition from wake to sleep can be facilitated by rocking movements, which might be related to relaxation. However, it is not yet known which movements would have the greatest effect. Thus, a 6-degree-of-freedom tendon-based robotic bed was developed, for systematic evaluation of vestibular stimuli. The applicability of the device was evaluated with 25 subjects. Six movement axes were tested and analyzed for differences in promoting relaxation. Relaxation was assessed by electroencephalogram, electrocardiogram, respiration and a questionnaire. The developed device fulfilled all needed requirements proving the applicability of this technology. Movements had no significant effects on the electroencephalogram and electrocardiogram. Respiration frequency was significantly lower for baseline measurements without movement (median 0.183-0.233 Hz) compared to movement conditions (median 0.283-0.300 Hz). Questionnaire ratings showed a trend (p = 0.057) toward higher relaxation for movements along the vertical axis (z-axis) (median 4.67; confidence interval 4.33-5.67) compared to the roll-axis (median 4.33; confidence interval 3.67-5.00). Movements along the vertical axis (z-axis), therefore, appear most promising in promoting relaxation, though no effects were found in electroencephalogram and electrocardiogram variables. This lack of effect might be attributed to the short exposure to the movements and the large inter-individual variability and individual preferences among subjects.

Effects of a Stress-Management Program for Inpatients With Mental Disorders: A Feasibility Study

Stress-management interventions have been integrated into treatments for people with mental disorders. Nevertheless, most studies on these interventions have been conducted on patients with schizophrenia in Western countries, and limited studies have used objective measurements of stress. We developed a group-based, four-session stress-management (S-Manage) program for people with mental disorders, consisting of two major components: psychoeducation and relaxation practice. This single-group, pretest-posttest, quasi-experimental study was undertaken to test the initial effects and determine the effect sizes of the program. A convenience sample of 55 inpatients were recruited from a mental health ward at a tertiary hospital in Singapore. Self-report questionnaires and physiological measures of stress (skin temperature and salivary immunoglobulin A [SIgA]) were used for data collection. Data were analyzed by descriptive statistics and repeated-measures analysis of variance. Most participants were Singaporean, female, single, and employed. Diagnoses included schizophrenia, depression, bipolar disorder, anxiety disorder, and mixed diagnoses. All received standard care provided by the hospital. Participants had significant reductions in objective stress, measured by skin temperature (effect size = 0.54) and SIgA (effect size = 0.16), and subjective stress (effect size = 0.16) as well as improved psychological health (effect size = 0.40) in response to the intervention. This study provides preliminary evidence to support the positive effects of the S-Manage program on people with mental disorders. Future studies should further test the efficacy of the program using more rigorous methods such as randomized controlled trial and multicenter study.

Preliminary effects of progressive muscle relaxation on cigarette craving and withdrawal symptoms in experienced smokers in acute cigarette abstinence: a randomized controlled trial

BACKGROUND

Cigarette craving usually occurs in conjunction with unpleasant feelings, including stress, as part of a withdrawal syndrome. Progressive muscle relaxation (PMR), a behavioral technique used to reduce stress by concentrating on achieving muscle relaxation, may reduce levels of cigarette craving and other substance-related negative feelings and withdrawal symptoms.

METHODS

Demographic and cigarette use data were collected from 32 experienced smokers at the King Chulalongkorn Memorial Hospital, Bangkok, Thailand using the Semi-Structured Assessment for Drug Dependence and Alcoholism. Participants were asked to refrain from smoking for at least 3 hours before the visit (acute abstinence) and were randomly allocated to a 1-session PMR group (n =16) or a control activity group (e.g., reading newspaper, n =16). The intervention group was instructed to practice PMR individually in a quiet, private, air-conditioned room for about 20minutes. Craving, other substance-related feelings, and autonomic nervous responses (e.g., blood pressure and pulse rate) were assessed immediately before and after the 1-session intervention.

RESULTS

There were no differences in demographics, cigarette use/dependence, and baseline craving characteristics between the PMR and control groups. However, the control group had higher levels of high and paranoia feeling, and pulse rate than the PMR group at baseline. After practicing PMR, but not after a control activity, smokers undergoing acute abstinence had significantly lower levels of cigarette craving, withdrawal symptoms, and systolic blood pressure than at baseline. After controlling for baseline differences, abstaining smokers using PMR had lower levels of cigarette craving, withdrawal symptoms, and systolic blood pressure than smokers who undertook a control activity.

CONCLUSIONS

PMR significantly reduces cigarette craving, withdrawal symptoms, and blood pressure in smokers undergoing acute abstinence. PMR may be used as an adjunct to cigarette dependency treatments.

Improved emotional stability in experienced meditators with concentrative meditation based on electroencephalography and heart rate variability

OBJECTIVE

To determine whether emotional stability distinguishes how experienced and novice meditators react to visual stimuli.

DESIGN

PARTICIPANTS practiced concentrative meditation and then responded to visual stimuli while continuing to meditate.

PARTICIPANTS

Ten experienced and 10 novice meditators responded to sequences of visual stimuli after concentrative meditation.

RESULTS

As predicted, both groups had increased parasympathetic activities during concentrative meditation. Experienced meditators had increased low-frequency electroencephalography (EEG) rhythms in response to visual stimulation, whereas novices had increased high-frequency EEG rhythms. Correlational analyses revealed that novice meditators changed from a meditative state to a nonrelaxed state when the visual stimuli were presented, whereas experienced meditators maintained the meditative state.

CONCLUSION

The study provides evidence that regular concentrative meditation can improve emotional stability and that recording physiologic responses to visual stimuli can be a good method for identifying the effects of long-term concentrative meditation practice.

Breathing-based meditation decreases posttraumatic stress disorder symptoms in U.S. military veterans: a randomized controlled longitudinal study

Given the limited success of conventional treatments for veterans with posttraumatic stress disorder (PTSD), investigations of alternative approaches are warranted. We examined the effects of a breathing-based meditation intervention, Sudarshan Kriya yoga, on PTSD outcome variables in U.S. male veterans of the Iraq or Afghanistan war. We randomly assigned 21 veterans to an active (n = 11) or waitlist control (n = 10) group. Laboratory measures of eye-blink startle and respiration rate were obtained before and after the intervention, as were self-report symptom measures; the latter were also obtained 1 month and 1 year later. The active group showed reductions in PTSD scores, d = 1.16, 95% CI [0.20, 2.04], anxiety symptoms, and respiration rate, but the control group did not. Reductions in startle correlated with reductions in hyperarousal symptoms immediately postintervention (r = .93, p < .001) and at 1-year follow-up (r = .77, p = .025). This longitudinal intervention study suggests there may be clinical utility for Sudarshan Kriya yoga for PTSD.

Oxygen Consumption Changes With Yoga Practices

Oxygen consumption varies with physical and mental activity as well as pathological conditions. Although there is a strong relationship between yoga and metabolic parameters, the relationship between yoga and oxygen consumption has not yet been formally reviewed. This systematic review attempted to include all studies of yoga that also measured oxygen consumption or metabolic rate as an outcome. A total of 58 studies were located involving between 1 and 104 subjects (average 21). The studies were generally of poor methodological quality and demonstrated great heterogeneity with different experimental designs, yoga practices, time periods, and small sample sizes. Studies report yoga practices to have profound metabolic effects producing both increase and decrease in oxygen consumption, ranging from 383% increase with cobra pose to 40% decrease with meditation. Compared to nonpractitioners, basal oxygen consumption is reported to be up to 15% less in regular yoga practitioners, and regular yoga practice is reported to have a training effect with oxygen consumption during submaximal exercise decreasing by 36% after 3 months. Yoga breathing practices emphasize breathing patterns and retention ratios as well as unilateral nostril breathing, and these factors appear critical in influencing oxygen consumption. A number of studies report extraordinary volitional control over metabolism in advanced yoga practitioners who appear to be able to survive extended periods in airtight pits and to exceed the limits of normal human endurance. More rigorous research with standardized practices is required to determine the mechanisms of yoga’s metabolic effects and the relevance of yoga practices in different clinical populations.

An assessment of a sequence of yoga exercises to patients with arterial hypertension

This quasi-experimental study describes the effects of a yoga sequence following hemodynamic and biochemical parameters in patients with hypertension. Thirty-three volunteers participated in the study (control = 16 and yoga = 17) for four months. Blood pressure measurements, cardiac and respiratory rate were collected monthly, while the biochemical profile was taken at the beginning and end of the program. To analyze the data, Student's t test and repeated measures analyses were performed. The yoga group showed a significant reduction of systolic blood pressure, heart and respiratory rate (p < 0.05). As for the biochemical profile, the yoga group showed correlation coefficients between initial values and final responses greater than the control of fasting glucose, total cholesterol, LDL-cholesterol and triglycerides. The elaborated sequence practice promoted significant cardiovascular and metabolic benefits. The yoga exercises performed in the proposed sequence constitute complementary non-pharmacological control of blood pressure in patients with hypertension.

Performance in a substitution task and state anxiety following yoga in army recruits

140 men (M age = 30.3 yr., SD = 5.7) from the Indian army in north India participated in the study. They were naive to yoga and were assigned to yoga and breath awareness groups randomly, with 70 in each group. 20 healthy males of comparable age (M age = 33.7 yr., SD = 7.0) formed a comparison group. Their performance in a digit-letter substitution task and a state anxiety subscale was assessed immediately before and after two 45-min. sessions. The two groups of soldiers practiced either yoga or breath awareness. The comparison group listened to meditation music. Digit-letter substitution scores increased in both groups of army personnel and in the comparison group. State anxiety decreased after yoga and listening to meditation music, but not after breath awareness. This suggests that even in army personnel naive to yoga, a yoga-based intervention or listening to meditation music could reduce anxiety while increasing performance on an attention task.

The effects of deep breathing on 'tension-anxiety' and fatigue in cancer patients undergoing adjuvant chemotherapy

AIMS

We investigated the effect of deep breathing intervention on 'tension-anxiety' and fatigue in Japanese women with gynaecological cancer undergoing adjuvant chemotherapy.

SETTING

A total of 23 patients were randomly allocated to intervention (n = 11) and control (n = 12) groups.

INTERVENTION

Deep breathing was practised in the intervention group, but not in the control group. Deep breathing comprised a 10-min breathing program comprising abdominal breathing, thoracic breathing and breathing with arms raised. Using the Profile of Mood States-Short Form (Japanese version) and the Cancer Fatigue Scale, the effects were assessed pre- and post-chemotherapy.

RESULTS

'Tension-anxiety' and fatigue of the intervention group were relieved more than those of the control group.

CONCLUSIONS

The findings indicated that deep breathing intervention is likely to ameliorate the 'tension-anxiety' and fatigue in patients with gynaecological cancer undergoing adjuvant chemotherapy.

To accomplish preliminary Qigong simulation state by acupuncture

OBJECTIVE

The purpose of the study was to find out how to enter the preliminary Qigong simulation state in a short period of time.

METHODS

This is a non-randomized, human experiment with healthy participants. A multi-channel digital physiological data recorder was used to detect whether the participants had entered the Qigong state. Participants were assisted to enter the Qigong state (relaxation, tranquility and naturalness) by being given the sore (sour) feeling produced by acupuncturing Hegu (LI4), and suggestions (repeating words "relax" and "heat" from the hypogastrium).

RESULTS

About 72.2% of the participants who had no Qigong experience were found entering the preliminary Qigong simulation state. Most of the physiological parameters measured after the participants entering the Qigong state showed significant changes compared with the baseline data.

CONCLUSION

This study revealed that acupuncture-made sore feeling is able to induce the participants to quickly enter the preliminary Qigong simulation state; hence this can be seen as no longer a limited phenomenon, but can be commonly applied to everybody.

Low latency breathing frequency detection and monitoring on a personal computer

We demonstrate a low latency respiratory/breathing frequency detection system that is fast (<5 ms), easy to operate, requires no batteries or external power supply and operates fully via computer-standard USB connection. Exercises in controlling ones breathing frequency, usually referred to as paced-breathing exercises, have shown positive effects in treating pulmonary diseases, cardiovascular diseases and stress/anxiety-related disorders. We developed a breathing frequency detection system which uses two pairs of microphones to detect exhalation activity, eliminate noise from the environment and stream the recording data via USB connection to a personal computer. It showed 97.1% reliability (10 subjects) when monitoring breathing activity in non-guided free breathing and 100% reliability (10 subjects) when monitoring breathing activity during interactive paced-breathing exercises. We also evaluated the breathing frequency detection systems noise elimination functionality which showed a reduction of 84.2 dB for stationary (white noise) and a reduction of 79.3 dB for non-stationary (hands clapping) noise.

Effect of a yoga practice session and a yoga theory session on state anxiety

Yoga techniques practiced for varying durations have been shown to reduce state anxiety. In this study, there were 300 naive-to-yoga persons of both sexes who were attending a yoga therapy center in north India for stress relief as day visitors and were not residing at the center. They were assigned to two groups, yoga practice and yoga theory, and their state anxiety was assessed before and after a 2-hr. yoga session. A significant reduction in scores on state anxiety was found in the yoga practice group (14.7% decrease), as well as in the yoga theory group (3.4% decrease). The difference in scores following the sessions was statistically significant. Hence, yoga practice as well as learning about theoretical aspects of yoga appear to reduce state anxiety, with a greater reduction following yoga practice.