Increased heart rate variability but no effect on blood pressure from 8 weeks of hatha yoga - a pilot study

Fourteen weeks of multicomponent training associated with flexibility training modifies postural alignment, joint range of motion and modulates blood pressure in physically inactive older women: a randomized clinical trial

Background: Body relaxation and pain reduction are some of the reported benefits of flexibility training (through active stretching exercises), however their effects on posture and blood circulation are uncertain. We aimed to investigate the effects of flexibility training (through active stretching exercises) in combination with multicomponent training (MT) on blood pressure (BP), and the correlation with changes in body alignment and flexibility in physically inactive women. Methods: Women aged 60-70 years were into three groups: multicomponent training group (MT), multicomponent training plus flexibility training group (FT), and control group (CG). After randomization, the resting blood pressure was measured and the participants were reallocated into subgroups according to pressure values >130/80 mmHg (This classification is according to the American Heart Association (AHA), resulting in the subgroups: flexibility training (FT); flexibility training for hypertensive patients (FTSAH); multicomponent training (MT); multicomponent training for hypertensive patients (MTSAH); control group (CG); control group of hypertensive patients (CGSAH). The interventions lasted 14 weeks. Systolic (sBP) and diastolic (dBP) BP, range of motion (flexion and extension), and postural analysis by asymmetry in the frontal plane and asymmetry in the sagittal plane, displacement and the flexibility test were collected before (Pre) and after training (Post). In total, 141 women participated in the study (without SAH: FT = 23, MT = 20, and CG = 21; with SAH: FTSAH = 28, MTSAH = 23, and CGSAH = 26). Results: Systolic blood pressure, in the pre and post moments were: FT (116 ± 6.7 vs. 114 ± 4.7); FTSAH (144 ± 16.5 vs. 121 ± 10.1); MT: (120 ± 6.8 vs. 121 ± 7.3); MTSAH: (137 ± 10.6 vs. 126 ± 13.0); CG: (122 ± 5.3 vs. 133 ± 19.2); and CGSAH: (140 ± 9.7 vs. 143 ± 26.2), presenting an F value (p-value - group x time) of 12.00 (<0.001), with improvement in the groups who trained. The diastolic blood pressure in the pre and post moments were: FT (71 ± 4.7 vs. 74 ± 6.8); FTSAH (88 ± 9.6 vs. 70 ± 12.0); MT: (74 ± 4.5 vs. 77 ± 11.7); MTSAH: (76 ± 10.4 vs. 76 ± 10.2); CG: (69 ± 7.11 vs. 82 ± 11.4); and CGSAH: (76 ± 13.4 vs. 86.6 ± 7.7), presenting an F value (p-value - group x time) of 8.00 (p < 0.001), with improvement in the groups who trained. In the Elastic Net Regression, sBP was influenced by height (β: -0.044); hip flexion (β: 0.071); Shoulder extension (β: 0.104); low back flexion (β: 0.119) and dBP (β: 0.115). In the Elastic Net Regression, dBP was influenced by asymmetry in the sagittal plane variables (0.040); asymmetry in the frontal plane (β: 0.007); knee flexion (β: -0.398); BM (β: 0.007); Shoulder flexion (β: -0.142); Hip flexion (β: -0.004); sBP (β: 0.155) and Ankle Flexion (β: -0.001). Conclusion: The displacement of the asymmetry in the frontal plane and asymmetry in the sagittal plane, and the increase in the flexion position in the hip, lumbar, head, and knee regions, influenced the highest-pressure levels. Multicomponent training associated with flexibility training promoted improvement in body alignment, COM, and joint angles, and decreased blood pressure.

Can XunTian Tai Chi intervention improve the level of emotional regulation of crew members in the Controlled Ecological Life Support System?

To explore the appropriate exercise methods and means for astronauts in confined and small isolation conditions, a set of XunTian Tai Chi suitable for the spaceflight workforce was created, with the aim of discovering the practical effects of XunTian Tai Chi and providing a scientific basis for the subsequent development of new astronaut health maintenance techniques with Chinese characteristics. Using the Controlled Ecological Life Support System (CELSS) as a research platform, we observed the changes in a crew member's emotion regulation-related indexes during 180 days of working and living in a confined isolation chamber through periodic interventions of the XunTian Tai Chi and conducted statistical analyses. During the 180-day cabin mission, expression suppression, cognitive reappraisal, attention index, and relaxation index were all lower than those before entering the cabin, suggesting that the crew member's emotion regulation ability decreased during the in-cabin mission. A single Tai Chi exercise could cause favorable changes in the indicators, positively affecting the crew member's emotional regulation. The attention and relaxation indices of the occupants were improved significantly by both single and periodic Tai Chi exercises. After the Tai Chi exercise cycle, the results of each index showed a certain degree of effect. The 180-day ground-based simulation of Tai Chi in the confinement of a space capsule positively affects the occupant's emotional regulation.

Effectiveness of yoga on Ewing's battery autonomic function test: cross-sectional study

INTRODUCTION

The cardiovascular autonomic functions can be tested by a Battery of five tests developed by Ewing and Clark in 1981 in Edinburgh. Yogic practices are immensely useful for physical, mental and spiritual development required for better autonomic function.

AIM AND OBJECTIVES

To assess the ANS (Autonomic function system) function with help of Ewing's Battery tests in yoga participants and healthy participants not practicing yoga.

MATERIALS AND METHODS

A cross-sectional study was conducted on 270 participants which were divided into two groups viz: 135 in healthy control (Group I) and 135 in yoga group (Group II). Subjects with informed consent between 40-50 years, were included in control (Group I) and those practicing yoga for past minimum 3 months were included in Group II. Anthropometric measurements were done and parasympathetic tests like Heart rate (HR) response to standing from the supine posture, to Valsalva maneuvers and to slow deep breathing were done. Also, sympathetic tests, Blood Pressure (BP) response to cold in cold pressor test (CPT), to sustained handgrip test and to standing from lying posture were carried out.

RESULTS

P value was found to be statically significant among yoga group as compared with healthy control group in all the sympathetic and parasympathetic tests except in CPT. As per the Ewing's criteria, normal, early, diseased and severe CAN (Cardiac autonomic neuropathy) in healthy controls findings were 11.11%, 58.51%, 37.03%, 17.77% and in yoga participants findings were 37.7%, 34.8%, 6.66% and 8.88% respectively. According to Bellavere's classification, maximum diseased CAN were found in healthy control as compared to yoga group. As per AIIMS (All India Institute of Medical Sciences) criteria, parasympathetic neuropathy was observed in 11.85% of the healthy controls and in 6.66% of the yoga group, and that maximum sympathetic neuropathy was observed in 11.11% of the healthy patients and only 3.7% of the yoga group.

CONCLUSION

More emphasis should be given on implementation of yoga from early ages at the institutional levels, hospital levels. Yoga practices will suffice and lead to improvement of unhealthy ANS condition. Overall, Yoga showed better ANS function than healthy control group.

Vascular Responses following Light Therapy: A Pilot Study with Healthy Volunteers

(1) Background: Studies have reported the effectiveness of light therapy in various medical conditions. Our pilot study aimed to assess the effect of Maharishi light therapy (MLT) on physiological parameters, such as the heart rate (HR), HR variability (HRV), blood pressure (BP), BP variability (BPV), and the retinal microvasculature of healthy participants; (2) Methodology: Thirty (14 males and 16 females) healthy, non-smoking participants between 23 and 71 years old (46 ± 18 years) were included in this randomized crossover study. Each participant was tested with a placebo (using LED light) and gem lights, 24 h apart. Hemodynamic parameters were recorded during the session, and 24 h heart rate and BP levels were assessed via mobile devices. Retinal vascular responses were captured with fundus images and the subsequent analysis of retinal vessel widths. A linear model, using repeated measures ANOVA, was used to compare the responses across the sexes and to assess the effect of the MLT; (3) Results: Changes in the central retinal artery equivalent (CRAE) (p < 0.001) and central retinal vein equivalent (CRVE) (p = 0.002) parameters were observed. CRAE and CRVE decreased under MLT and increased under the placebo condition from before to after. However, the baseline values of the participants already differed significantly before the application of any therapy, and the variation in the retinal vessel diameters was already large in the baseline measurements. This suggests that the observed effect results may only reflect naturally occurring fluctuations in the microcirculation and not the effect of MLT. Furthermore, no significant effects were observed in any other investigated parameters; (4) Conclusion: Our study with healthy participants finds significant changes in retinal parameters, but the biological variation in the baseline measurements was large to begin with. This suggests that the observed effect results only reflect naturally occurring fluctuations in the microcirculation and not the effect of MLT. However, in the future, larger studies in which MLT is applied for longer periods and/or in patients with different diseases could discover the physiological impacts of this type of therapy.

Effect of mindfulness on anxiety and depression in insomnia patients: A systematic review and meta-analysis

Background

As a common clinical symptom, insomnia has a high incidence of combined mental illness and it is also a risk factor for the development of depression, anxiety and suicide. As a new concept in the field of health in recent years, mindfulness therapy can improve insomnia, anxiety and depression, which is a new way to solve such diseases.

Objective

This study aims to systematically evaluate the effects of mindfulness compared with conventional treatment on scores of the Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), Self-Rating Depression Scale (SDS) and Self-Rating Anxiety Scale (SAS) in people with insomnia and anxiety-depressive symptoms.

Methods

Articles published before October 2022 were searched from seven databases and included in randomized controlled trials (RCTs) to evaluate mindfulness therapy. The assessment tool of Cochrane bias risk was used to evaluate the methodological quality of the literature. The main outcome indicators were HAMD and HAMA scores, and the secondary outcome indicators were SDS and SAS scores.

Results

Ten randomized controlled trials including 1,058 subjects were systematically evaluated and meta-analyzed in this study. In the main outcome indicators, there was a significant difference between mindfulness therapy and conventional treatment in reducing HAMD score (MD: -3.67, 95% CI: -5.22-2.11, p < 0.01) and HAMA score (MD: -3.23, 95% CI: -3.90-2.57, p < 0.01). In the secondary outcome indicators, mindfulness therapy also showed a significant difference in reducing SDS scores (MD: -6.49, 95% CI: -6.86-6.11, p < 0.01) and SAS scores (MD: -7.97, 95% CI: -9.68-6.27, p < 0.01) compared with conventional treatment.

Conclusion

For the people with insomnia, anxiety and depression, the use of conventional treatment with the addition of 4-12 weeks of mindfulness treatment can significantly improve anxiety and depression symptoms of patients. This is a new diagnosis and treatment idea recommended for insomniacs with or without anxiety and depression symptoms. Due to the methodological defects in the included study and the limited sample size of this paper, more well-designed randomized controlled trials are needed for verification.

High vagally mediated resting-state heart rate variability is associated with superior working memory function

Background

Heart rate variability (HRV), a cardiac vagal tone indicator, has been proven to predict performance on some cognitive tasks that rely on the prefrontal cortex. However, the relationship between vagal tone and working memory remains understudied. This study explores the link between vagal tone and working memory function, combined with behavioral tasks and functional near-infrared spectroscopy (fNIRS).

Methods

A total of 42 undergraduate students were tested for 5-min resting-state HRV to obtain the root mean square of successive differences (rMSSD) data, and then divided into high and low vagal tone groups according to the median of rMSSD data. The two groups underwent the n-back test, and fNIRS was used to measure the neural activity in the test state. ANOVA and the independent sample t-test were performed to compare group mean differences, and the Pearson correlation coefficient was used for correlation analysis.

Results

The high vagal tone group had a shorter reaction time, higher accuracy, lower inverse efficiency score, and lower oxy-Hb concentration in the bilateral prefrontal cortex in the working memory tasks state. Furthermore, there were associations between behavioral performance, oxy-Hb concentration, and resting-state rMSSD.

Conclusion

Our findings suggest that high vagally mediated resting-state HRV is associated with working memory performance. High vagal tone means a higher efficiency of neural resources, beneficial to presenting a better working memory function.

Exploring of cardiac autonomic activity with heart rate variability in long-term kratom (Mitragyna speciosa Korth.) users: a preliminary study

Background

Kratom is a psychoactive plant used to enhance productivity among laborers in Southeast Asian countries. Previous findings from in vitro research of mitragynine, a major component of kratom, suggested a possible risk of heart function abnormality. However, the cardiac autonomic function in long-term kratom users with chewing forms has never been studied. This study aimed to investigate heart rate variability (HRV) indices of cardiac autonomic function in long-term kratom chewers (LKC), compared to the control levels, and also to examine the correlation between HRV indices and relevant kratom use factors.

Method

A total number of 50 participants consisted of LKC (n = 31) who regularly chewed fresh kratom leaves for at least 2 years and demographically matched control subjects (n = 19). Resting electrocardiogram (ECG) signals were recorded from subjects for 3 min to analyze the ultrashort HRV in the frequency domain. The normalized low frequency (LFn) and high frequency (HFn) were chosen to be the HRV indices to evaluate cardiac autonomic function. The comparison of HRV indices between groups and the correlation between HRV indices and duration and quantity of kratom use was further conducted in statistical analysis.

Results

The LKC significantly increased LFn together with enhanced HFn compared to the control group tested, indicating that LKC changed cardiac autonomic function with parasympathetic dominance. Furthermore, no significant correlation between the HRV indices and the duration and quantity of kratom use was found, suggesting that the HRV indices were not relevant to these factors. The present study provided scientific-based evidence of cardiac autonomic modulation in long-term kratom chewers. LFn and HFn may be promising cardiac autonomic indicators for monitoring health outcomes in LKC.

Mind–Body Exercises for PTSD Symptoms, Depression, and Anxiety in Patients With PTSD: A Systematic Review and Meta-Analysis

Objectives

This study aims to systematically analyze the effects of mind–body exercises on post-traumatic stress disorder (PTSD) symptoms, depression, and anxiety in patients with PTSD. Furthermore, it intends to provide scientific evidence-based exercise prescriptions.

Methods

Chinese (i.e., China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, and Wanfang) and English (i.e., Web of Science, PubMed, the Cochrane Library, and EMBASE) databases were used as data sources to search for studies on the effects of mind–body exercises on symptoms associated with patients with PTSD from January 1980 to November 2020. After a rigorous screening, 16 eligible randomized controlled trials (RCTs) were included in the meta-analysis.

Results

Mind–body exercises exerted a significant effect on PTSD symptoms [standard mean difference (SMD) = −0.41, 95% confidence interval (CI) −0.64 to −0.19, p < 0.001], depression (SMD = −0.35, 95% CI: −0.55 to −0.15, p < 0.001), and anxiety (SMD = −0.31, 95% CI: −0.74 to −0.12, p < 0.001) among patients with PTSD. Subgroup analysis demonstrated that 60–150 min per session for 8–16 weeks of mindfulness was more effective in improving symptoms in patients with PTSD under 45 years of age compared with other subgroups. For depression, 150–180 min of yoga exercises once per week was effective. For anxiety, the frequency, timing, duration, and type of mind–body exercises that are most effective in relieving anxiety in patients with PTSD cannot be determined at this time due to the limited number of eligible RCTs.

Conclusions

Mind–body exercises were found to be significantly effective in improving PTSD symptoms, depression, and anxiety in patients with PTSD. Therefore, they can be used as an adjunct to intervention for symptoms of patients with PTSD. However, this conclusion requires further confirmation through additional scientific and objective RCTs.

Systematic Review Registration:

Unique Identifier: INPLASY2020120072.

Effects of Hatha Yoga on Cardiac Hemodynamic Parameters and Physical Capacity in Cardiac Rehabilitation Patients

PURPOSE

The purpose of the present study was to assess the effect of hatha yoga training that was added to the standard cardiac rehabilitation (CR) program on the cardiac hemodynamic parameters and physical capacity of patients with ST-elevation myocardial infarction (STEMI).

METHODS

The study included 70 male patients aged 45-65 yr with STEMI who were treated by angioplasty. Patients were randomized to standard CR (control group) versus standard CR plus hatha yoga (experimental group). The training program lasted for a total of 24 d for each patient, with day 1 and day 24 used for medical examinations (electrocardiogram, spiroergometric submaximal treadmill test, and echocardiography). The remaining 22 d consisted of the actual training.

RESULTS

After the CR program the spiroergometric stress test parameters and left ventricular ejection fraction (LVEF) improved in both the experimental and control groups. The most notable changes in echocardiography parameters and physical capacity were in the experimental group. The results showed significant main effect over time, a time-versus-group interaction in LVEF, the duration of the test, and peak oxygen uptake, and a time-versus-group interaction in metabolic equivalents (METs). We also noted the improvement of left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and heart rate over time.

CONCLUSION

The results revealed better effectiveness in the CR program with a modified hatha yoga training program. Hatha yoga training could be recommended as an adjunct to standard CR.

A randomized controlled trial of yoga vs nonaerobic exercise for veterans with PTSD: Understanding efficacy, mechanisms of change, and mode of delivery

BACKGROUND AND OBJECTIVES

Posttraumatic stress disorder (PTSD) is a chronic, disabling, and prevalent mental health disorder among Veterans. Despite the availability of empirically supported psychotherapies, many Veterans remain symptomatic after treatment and/or prefer to seek complementary and integrative health approaches, including yoga, to manage PTSD. The randomized controlled trial (RCT) described herein will evaluate the efficacy of a manualized yoga program as compared to nonaerobic exercise in reducing PTSD severity among Veterans. A secondary aim of this study is to better understand the mechanisms of change.

METHODS

Veterans (N = 192) with PTSD will be randomized to hatha yoga or nonaerobic physical activity control; both groups consist of 12 weekly, 60-min group or online training sessions with 15-20 min of daily at-home practice. Outcome measures will be administered at baseline, mid-treatment, posttreatment, and 12-week follow-up.

PROJECTED OUTCOMES

This study will evaluate changes in PTSD severity (primary outcome) as well as depression, anxiety, anger, sleep problems, and psychosocial disability (secondary outcomes). We will also use multiple mediation to examine two potential models of the mechanisms of clinical effect: the Attention Model (i.e., yoga increases attentional control, which reduces PTSD symptoms), the Coping Model (i.e., yoga increases distress tolerance, which improves coping, which reduces PTSD symptoms), and the combination of these models. This aspect of the study is innovative and important given the absence of an existing, comprehensive model for understanding yoga's impact on PTSD. Ultimately, we hope to develop guidelines for application of yoga to PTSD recovery.

Bayesian Estimation of Correlation between Measures of Blood Pressure Indices, Aerobic Capacity and Resting Heart Rate Variability Using Markov Chain Monte Carlo Simulation and 95% High Density Interval in Female School Teachers

Background: Several explanations regarding the disparity observed in the literature with regard to heart rate variability (HRV) and its association with performance parameters have been proposed: the time of day when the recording was conducted, the condition (i.e., rest, active, post activity) and the mathematical and physiological relationships that could have influenced the results. A notable observation about early studies is that they all followed the frequentist approach to data analyses. Therefore, in an attempt to explain the disparity observed in the literature, the primary purpose of this study was to estimate the association between measures of HRV indices, aerobic performance parameters and blood pressure indices using the Bayesian estimation of correlation on simulated data using Markov Chain Monte Carlo (MCMC) and the equal probability of the 95% high density interval (95% HDI). Methods: The within-subjects with a one-group pretest experimental design was chosen to investigate the relationship between baseline measures of HRV (rest; independent variable), myocardial work (rate–pressure product (RPP)), mean arterial pressure (MAP) and aerobic performance parameters. The study participants were eight local female schoolteachers aged 54.1 ± 6.5 years (mean ± SD), with a body mass of 70.6 ± 11.5 kg and a height of 164.5 ± 6.5 cm. Their HRV data were analyzed in R package, and the Bayesian estimation of correlation was calculated employing the Bayesian hierarchical model that uses MCMC simulation integrated in the JAGS package. Results: The Bayesian estimation of correlation using MCMC simulation reproduced and supported the findings reported regarding norms and the within-HRV-indices associations. The results of the Bayesian estimation showed a possible association (regardless of the strength) between pNN50% and MAP (rho = 0.671; 95% HDI = 0.928–0.004), MeanRR (ms) and RPP (rho = −0.68; 95% HDI = −0.064–−0.935), SDNN (ms) and RPP (rho = 0.672; 95% HDI = 0.918–0.001), LF (ms²) and RPP (rho = 0.733; 95% HDI = 0.935–0.118) and SD2 and RPP (rho = 0.692; 95% HDI = 0.939–0.055). Conclusions: The Bayesian estimation of correlation with 95% HDI on MCMC simulated data is a new technique for data analysis in sport science and seems to provide a more robust approach to allocating credibility through a meaningful mathematical model. However, the 95% HDI found in this study, accompanied by the theoretical explanations regarding the dynamics between the parasympathetic nervous system and the sympathetic nervous system in relation to different recording conditions (supine, reactivation, rest), recording systems, time of day (morning, evening, sleep etc.) and age of participants, suggests that the association between measures of HRV indices and aerobic performance parameters has yet to be explicated.

Changes in Heart Rate Variability after Yoga are Dependent on Heart Rate Variability at Baseline and during Yoga: A Study Showing Autonomic Normalization Effect in Yoga-Naïve and Experienced Subjects

Background:

Yoga therapy is widely applied to the maintenance of health and to treatment of various illnesses. Previous researches indicate the involvement of autonomic control in its effects, although the general agreement has not been reached regarding the acute modulation of autonomic function.

Aim:

The present study aimed at revealing the acute effect of yoga on the autonomic activity using heart rate variability (HRV) measurement.

Methods:

Twenty-seven healthy controls participated in the present study. Fifteen of them (39.5 ± 8.5 years old) were naïve and 12 (45.1 ± 7.0 years old) were experienced in yoga. Yoga skills included breath awareness, two types of asana, and two types of pranayama. HRV was measured at the baseline, during yoga, and at the resting state after yoga.

Results:

In both yoga-naïve and experienced participants, the changes in low-frequency (LF) component of HRV and its ratio to high-frequency (HF) component (LF/HF) after yoga were found to be correlated negatively with the baseline data. The changes in LF after yoga were also correlated with LF during yoga. The changes in HF as well as the raw HRV data after yoga were not related to the baseline HRV or the HRV during yoga.

Conclusion:

The results indicate that yoga leads to an increase in LF when LF is low and leads to a decrease in LF when it is high at the baseline. This normalization of LF is dependent on the autonomic modulation during yoga and may underlie the clinical effectiveness of yoga therapy both in yoga-naïve and experienced subjects.

#MindinBody - feasibility of vigorous exercise (Bikram yoga versus high intensity interval training) to improve persistent pain in women with a history of trauma: a pilot randomized control trial

BACKGROUND

The neurobiology of persistent pain shares common underlying psychobiology with that of traumatic stress. Modern treatments for traumatic stress often involve bottom-up sensorimotor retraining/exposure therapies, where breath, movement, balance and mindfulness, are used to target underlying psychobiology. Vigorous exercise, in particular Bikram yoga, combines many of these sensorimotor/exposure therapeutic features. However, there is very little research investigating the feasibility and efficacy of such treatments for targeting the underlying psychobiology of persistent pain.

METHODS

This study was a randomized controlled trail (RCT) comparing the efficacy of Bikram yoga versus high intensity interval training (HIIT), for improving persistent pain in women aged 20 to 50 years. The participants were 1:1 randomized to attend their assigned intervention, 3 times per week, for 8 weeks. The primary outcome measure was the Brief Pain Inventory (BPI) and further pain related biopsychosocial secondary outcomes, including SF-36 Medical Outcomes and heart rate variability (HRV), were also explored. Data was collected pre (t0) and post (t1) intervention via an online questionnaire and physiological testing.

RESULTS

A total of 34 women were recruited from the community. Analyses using ANCOVA demonstrated no significant difference in BPI (severity plus interference) scores between the Bikram yoga (n = 17) and the HIIT (n = 15). Women in the Bikram yoga group demonstrated significantly improved SF-36 subscale physical functioning: [ANCOVA: F(1, 29) = 6.17, p = .019, partial eta-squared effect size (ηp2) = .175 and mental health: F(1, 29) = 9.09, p = .005, ηp2 = .239; and increased heart rate variability (SDNN): F(1, 29) = 5.12, p = .013, ηp2 = .150, scores compared to the HIIT group. Across both groups, pain was shown to decrease, no injuries were experienced and retention rates were 94% for Bikram yoga and 75% for HIIT .

CONCLUSIONS

Bikram yoga does not appear a superior exercise compared to HIIT for persistent pain. However, imporvements in quality of life measures and indicator of better health were seen in the Bikram yoga group. The outcomes of the present study suggest vigorous exercise interventions in persistent pain cohorts are feasible.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ( ACTRN12617001507370 , 26/10/2017).

Breath Rate Variability: A Novel Measure to Study the Meditation Effects

Context:

Reliable quantitative measure of meditation is still elusive. Although electroencephalogram (EEG) and heart rate variability (HRV) are known as quantitative measures of meditation, effects of meditation on EEG and HRV may well take long time as these measures are involuntarily controlled. Effect of mediation on respiration is well known; however, quantitative measures of respiration during meditation have not been studied.

Aims:

Breath rate variability (BRV) as an alternate measure of meditation even over a short duration is proposed. The main objective of this study is to test the hypothesis that BRV is a simple measure that differentiates between meditators and nonmeditators.

Settings and Design:

This was a nonrandomized, controlled trial. Volunteers meditate in their natural habitat during signal acquisition.

Subjects and Methods:

We used Photo-Plythysmo-Gram (PPG) signal acquisition system from BIO-PAC and recorded video of chest and abdomen movement due to respiration during a short meditation (15 min) session for 12 individuals (all males) meditating in a relaxed sitting posture. Seven of the 12 individuals had substantial experience in meditation, while others are controls without any experience in meditation. Respiratory signal from PPG signal was derived and matched with that of the video respiratory signal. This derived respiratory signal is used for calculating BRV parameters in time, frequency, nonlinear, and time-frequency domain.

Statistical Analysis Used:

First, breath-to-breath interval (BBI) was calculated from the respiration signal, then time domain parameters such as standard deviation of BBI (SDBB), root mean square value of SDBB (RMSSD), and standard deviation of SDBB (SDSD) were calculated. We performed spectral analysis to calculate frequency domain parameters (power spectral density [PSD], power of each band, peak frequency of each band, and normalized frequency) using Burg, Welch, and Lomb–Scargle (LS) method. We calculated nonlinear parameters (sample entropy, approximate entropy, Poincare plot, and Renyi entropy). We calculated time frequency parameters (global PSD, low frequency-high frequency [LF-HF] ratio, and LF-HF power) by Burg LS and wavelet method.

Results:

The results show that the mediated individuals have high value of SDSD (+24%), SDBB (+29%), and RMSSD (+26%). Frequency domain analysis shows substantial increment in LFHF power (+73%) and LFHF ratio (+33%). Nonlinear parameters such as SD1 and SD2 were also more (>20%) for meditated persons.

Conclusions:

As compared to HRV, BRV can provide short-term effect on anatomic nervous system meditation, while HRV shows long-term effects. Improved autonomic function is one of the long-term effects of meditation in which an increase in parasympathetic activity and decrease in sympathetic dominance are observed. In future works, BRV could also be used for measuring stress.

The effect of movement-focused and breath-focused yoga practice on stress parameters and sustained attention: A randomized controlled pilot study

Yoga-based practices (YBP) typically involve a combination of movement sequences, conscious regulation of the breath, and techniques to engage attention. However, little is known about whether effects of YBP result from the synergistic combination of these components, or whether a subset may yield similar effects. In this study we compared the effect of a movement-focused practice and a breath-focused practice on stress parameters (perceived stress and salivary cortisol) and sustained attention (response inhibition) in yoga naïve university students. While participants of both programs showed a reduction in perceived stress and salivary cortisol, only the breath-focused group showed improvements in sustained attention. In addition, improvement in sustained attention was correlated with reduction in perceived stress but not with reduction in salivary cortisol. We discuss these findings in the context of a theoretical framework outlining bottom-up neurophysiological and top-down neurocognitive mechanisms hypothesized to be engaged by YBP.

Military-Tailored Yoga for Veterans with Post-traumatic Stress Disorder

Introduction

Among veterans of post-9/11 conflicts, estimates of post-traumatic stress disorder (PTSD) range from 9% shortly after returning from deployment to 31% a year after deployment. Clinical and pharmaceutically based treatments are underutilized. This could be due to concerns related to lost duty days, as well as PTSD patients' fears of stigma of having a mental health condition. Yoga has been shown to reduce PTSD symptoms in the civilian population, but few studies have tested the impact of yoga on veterans of post-9/11 conflicts. The purpose of this study is to test the impact of yoga on post-9/11 veterans diagnosed with PTSD.

Materials and Methods

Participants were 18 yr of age or older and veterans of post-9/11 conflicts. They had subthreshold or diagnostic-level PTSD related to their combat military service, as determined by a score of 30 or higher on the PTSD Checklist-Military version (PCL-M). Veterans participated in 60-min weekly yoga sessions for 6 wk taught by a Warriors at Ease-trained yoga instructor who is a, post-9/11 veteran. The yoga sessions incorporated Vinyasa-style yoga and a trauma-sensitive, military-culture informed approach advocated by two separate organizations: Warriors at Ease and Meghan's Foundation. Data were collected at baseline and again after 7 wk. The primary outcome was PCL-M score. Participants also completed the Patient Health Questionnaire, the Beck Anxiety Inventory, the Pittsburgh Sleep Quality Index, and the Mindful Attention Awareness Scale at both time points.

Results

Eighteen Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn veterans completed the pre- and post-intervention self-report questionnaires. Age ranged from 26 to 62 yr (median = 43 yr), length of service ranged from 2 to 34 yr (median = 18.8 yr), and 13 (72.2%) had completed college. Decreased PTSD symptomatology was demonstrated in the three-symptom clusters represented in the PCL-M (i.e., hyperarousal, re-experiencing, and avoidance). In addition, the total score on the PCL-M decreased significantly, by both statistical and clinical measures. The participants also demonstrated improved mindfulness scores and reported decreased insomnia, depression, and anxiety symptoms.

Conclusion

This study demonstrates that a trauma-sensitive yoga intervention may be effective for veterans with PTSD symptoms, whether as stand-alone or adjunctive therapy. The impressive decrease in PTSD symptomatology may be due to the tailored military-specific nature of this intervention and the fact that it was led by a veteran of post-9/11 conflicts. More research is needed with a larger sample and a more diverse veteran population.

Unique Autonomic Responses to Pain in Yoga Practitioners

OBJECTIVE

Autonomic nervous system activity is associated with neurobehavioral aspects of pain. Yogis use breathing, relaxation, and mindfulness to tolerate pain, which could influence autonomic responses. To evaluate how the link between autonomic responses and pain is altered by other factors, we compared perceptual and autonomic responses to pain between yogis and controls.

METHODS

Nineteen yogis and 15 controls rated warm and painfully hot stimuli (1-cm thermode on calf), with visual anticipatory cues indicating certainly painful, certainly nonpainful, or uncertainly either painful or nonpainful. Heart rate, skin conductance, respiration, and blood pressure were measured.

RESULTS

At baseline, yogis breathed slower and deeper than did controls, with no differences in other autonomic measures. During the task, perceptual ratings did not differ between groups in either the certain or uncertain conditions. Nevertheless, yogis had higher phasic skin conductance responses in anticipation of and response to all stimuli, but particularly during painful heat in uncertain contexts (uncertain: 0.46 [0.34] μS; certain: 0.37 [0.28] μS; t(18) = 3.962, p = .001). Furthermore, controls showed a decrease in heart rate to warm (-2.51 [2.17] beats/min) versus painful stimuli (0.83 [1.63] beats/min; t(13) = 5.212, p < .001) and lower respiratory sinus arrhythmia during pain compared with warm trials, whereas yogis had similar reactions to painful and nonpainful stimuli.

CONCLUSIONS

Autonomic responses to pain differed in yogis and healthy volunteers, despite similar pain ratings. Thus, autonomic reactivity to pain may be altered by environmental and psychological factors throughout an individual's life.

Yoga Offers Cardiovascular Protection in Early Postmenopausal Women

CONTEXT

Postmenopause, an estrogen deficient state comes with increased incidence of cardiovascular diseases (CVDs). Yoga has been described as having a beneficial effect on heart rate variability (HRV), a marker for cardiac autonomic activity which can assess cardiovascular risk, in various populations.

AIM

the aim of the study was to study the effect of 3-month long Yoga practice on HRV in early postmenopausal women.

SETTINGS AND DESIGN

A prospective longitudinal study of 67 women within 5 years of menopause between 45 and 60 years of age attending menopause clinic of Department of Gynaecology, Sucheta Kriplani Hospital fulfilling inclusion and exclusion criteria and consenting were enrolled for the study.

SUBJECTS AND METHODS

HRV of 37 cases (Yoga group) and 30 controls (non-Yoga group) was recorded pre and 3-month postintervention.

STATISTICAL ANALYSIS USED

GraphPad Prism Version 5 software was used. Values are a mean and standard error of mean. Statistical significance was set up at P < 0.05.

RESULTS

In HRV, frequency domain analysis showed a significant fall in low frequency (LF) in normalized units (nu) and LF: high frequency (HF) ratio and significant rise in HF in nu in the Yoga group (depicting parasympathetic dominance) against a significant rise in LF (nu) and LF: HF ratio and significant fall in HF (nu) in non-Yoga group (indicating sympathetic dominance). Time domain analysis showed a significant decrease in Standard Deviation of NN intervals in Non-Yoga group against nonsignificant changes in Yoga group indicating deterioration in parasympathetic activity in non-Yoga group.

CONCLUSIONS

Three-month long Yoga practice improved HRV in early postmenopausal women significantly and has the potential to attenuate the CVD risk in postmenopausal women.

Integrative Therapy Approaches for Posttraumatic Stress Disorder: A Special Focus on Treating Veterans

Over the past decade, the use of integrative health modalities, such as mind-body interventions, art therapy, nutrition, and exercise, to treat stress-related mental health conditions, including posttraumatic stress disorder (PTSD), in military and veteran populations has been increasing. The use of integrative therapies for PTSD provides options for veterans who are not interested in traditional modalities, have limited access to traditional treatments, or are seeking a more comprehensive approach to managing their PTSD or subthreshold symptoms. These therapies show promise for improving overall well-being and comorbid conditions with PTSD, such as pain or migraines, but yield mixed data for PTSD symptoms. The aim of this article is to review the evidence for the most promising integrative health modalities for treating PTSD, with a special focus on the treatment of veterans, as well as to offer recommendations and suggestions for clinicians.

Effect of a 16-week Bikram yoga program on heart rate variability and associated cardiovascular disease risk factors in stressed and sedentary adults: A randomized controlled trial

Background

Chronic activation of the stress-response can contribute to cardiovascular disease risk, particularly in sedentary individuals. This study investigated the effect of a Bikram yoga intervention on the high frequency power component of heart rate variability (HRV) and associated cardiovascular disease (CVD) risk factors (i.e. additional domains of HRV, hemodynamic, hematologic, anthropometric and body composition outcome measures) in stressed and sedentary adults.

Methods

Eligible adults were randomized to an experimental group (n = 29) or a no treatment control group (n = 34). Experimental group participants were instructed to attend three to five supervised Bikram yoga classes per week for 16 weeks at local studios. Outcome measures were assessed at baseline (week 0) and completion (week 17).

Results

Sixty-three adults (37.2 ± 10.8 years, 79% women) were included in the intention-to-treat analysis. The experimental group attended 27 ± 18 classes. Analyses of covariance revealed no significant change in the high-frequency component of HRV (p = 0.912, partial η² = 0.000) or in any secondary outcome measure between groups over time. However, regression analyses revealed that higher attendance in the experimental group was associated with significant reductions in diastolic blood pressure (p = 0.039; partial η² = 0.154), body fat percentage (p = 0.001, partial η² = 0.379), fat mass (p = 0.003, partial η² = 0.294) and body mass index (p = 0.05, partial η² = 0.139).

Conclusions

A 16-week Bikram yoga program did not increase the high frequency power component of HRV or any other CVD risk factors investigated. As revealed by post hoc analyses, low adherence likely contributed to the null effects. Future studies are required to address barriers to adherence to better elucidate the dose-response effects of Bikram yoga practice as a medium to lower stress-related CVD risk.

Trial registration

Retrospectively registered with Australia New Zealand Clinical Trials Registry ACTRN12616000867493. Registered 04 July 2016.

Complexity Variability Assessment of Nonlinear Time-Varying Cardiovascular Control

The application of complex systems theory to physiology and medicine has provided meaningful information about the nonlinear aspects underlying the dynamics of a wide range of biological processes and their disease-related aberrations. However, no studies have investigated whether meaningful information can be extracted by quantifying second-order moments of time-varying cardiovascular complexity. To this extent, we introduce a novel mathematical framework termed complexity variability, in which the variance of instantaneous Lyapunov spectra estimated over time serves as a reference quantifier. We apply the proposed methodology to four exemplary studies involving disorders which stem from cardiology, neurology and psychiatry: Congestive Heart Failure (CHF), Major Depression Disorder (MDD), Parkinson's Disease (PD), and Post-Traumatic Stress Disorder (PTSD) patients with insomnia under a yoga training regime. We show that complexity assessments derived from simple time-averaging are not able to discern pathology-related changes in autonomic control, and we demonstrate that between-group differences in measures of complexity variability are consistent across pathologies. Pathological states such as CHF, MDD, and PD are associated with an increased complexity variability when compared to healthy controls, whereas wellbeing derived from yoga in PTSD is associated with lower time-variance of complexity.

Effects of Yoga on Heart Rate Variability and Depressive Symptoms in Women: A Randomized Controlled Trial

OBJECTIVES

The purpose of the study was to investigate the effects of a 12-week yoga program on heart rate variability (HRV) and depressive symptoms in depressed women.

METHODS

This was a randomized controlled trial. Twenty-six sedentary women scoring ≥14 on the Beck Depression Inventory-II were randomized to either the yoga or the control group. The yoga group completed a 12-week yoga program, which took place twice a week for 60 min per session and consisted of breathing exercises, yoga pose practice, and supine meditation/relaxation. The control group was instructed not to engage in any yoga practice and to maintain their usual level of physical activity during the course of the study. Participants' HRV, depressive symptoms, and perceived stress were assessed at baseline and post-test.

RESULTS

The yoga group had a significant increase in high-frequency HRV and decreases in low-frequency HRV and low frequency/high frequency ratio after the intervention. The yoga group also reported significantly reduced depressive symptoms and perceived stress. No change was found in the control group.

CONCLUSIONS

A 12-week yoga program was effective in increasing parasympathetic tone and reducing depressive symptoms and perceived stress in women with elevated depressive symptoms. Regular yoga practice may be recommended for women to cope with their depressive symptoms and stress and to improve their HRV.

Yoga practice improves executive function by attenuating stress levels

BACKGROUND

Prolonged activation of the hypothalamus-pituitary-adrenal system is thought to have deleterious effects on brain function. Neuroendocrine studies suggest that brain exposure to higher cortisol concentrations contribute to cognitive deficits as we age. Mind-body techniques such as yoga have shown to improve stress levels by restoring the body's sympathetic-parasympathetic balance. The objective of this study was to determine whether yoga practice moderated the stress response resulting in improved executive function.

METHODS

Sedentary community dwelling older adults (N=118, Mean age=62.02) were randomized to an 8-week yoga intervention or a stretching control group. At baseline and following 8 weeks, all participants completed measures of executive function, self-reported stress and anxiety and provided saliva samples before and after cognitive testing to assess cortisol.

RESULTS

Yoga participants showed improved accuracy on executive function measures and an attenuated cortisol response compared to their stretching counterparts who showed increased cortisol levels and poor cognitive performance at follow up. The change in cortisol levels as well as self-reported stress and anxiety levels predicted performance on the running span task, n-back working memory and task switching paradigm (β's=0.27-0.38, p's≤0.05 for yoga and β's=-0.37-0.47, p's≤0.01 for stretching control).

CONCLUSION

Eight weeks of regular yoga practice resulted in improved working memory performance that was mediated by an attenuated response to stress as measured by self-report stress and objective salivary cortisol measurements. This trial offers evidence for non-traditional physical activity interventions such as yoga that may be helpful in restoring HPA balance in older adults, thereby preventing cognitive decline.

Yoga and heart rate variability: A comprehensive review of the literature

Heart rate variability (HRV) has been used as a proxy for health and fitness and indicator of autonomic regulation and therefore, appears well placed to assess the changes occurring with mind.-body practices that facilitate autonomic balance. While many studies suggest that yoga influences HRV, such studies have not been systematically reviewed. We aimed to systematically review all published papers that report on yoga practices and HRV. A comprehensive search of multiple databases was conducted and all studies that reported a measure of HRV associated with any yoga practice were included. Studies were categorized by the study design and type of yoga practice. A total of 59 studies were reviewed involving a total of 2358 participants. Most studies were performed in India on relatively small numbers of healthy male yoga practitioners during a single laboratory session. Of the reviewed studies, 15 were randomized controlled trials with 6 having a Jadad score of 3. The reviewed studies suggest that yoga can affect cardiac autonomic regulation with increased HRV and vagal dominance during yoga practices. Regular yoga practitioners were also found to have increased vagal tone at rest compared to non-yoga practitioners. It is premature to draw any firm conclusions about yoga and HRV as most studies were of poor quality, with small sample sizes and insufficient reporting of study design and statistical methods. Rigorous studies with detailed reporting of yoga practices and any corresponding changes in respiration are required to determine the effect of yoga on HRV.

The Effects of Bikram Yoga on Health: Critical Review and Clinical Trial Recommendations

Bikram yoga is a style of hatha yoga involving a standarized series of asanas performed to an instructional dialogue in a heated environment (40.6°C, 40% humidity). Several studies evaluating the effect of Bikram yoga on health-related outcomes have been published over the past decade. However, to date, there are no comprehensive reviews of this research and there remains a lack of large-scale, robustly-designed randomised controlled trials (RCT) of Bikram yoga training. The purpose of this review is to contextualise and summarise trials that have evaluated the effects of Bikram yoga on health and to provide recommendations for future research. According to published literature, Bikram yoga has been shown to improve lower body strength, lower and upper body range of motion, and balance in healthy adults. Non-RCTs report that Bikram yoga may, in some populations, improve glucose tolerance, bone mineral density, blood lipid profile, arterial stiffness, mindfulness, and perceived stress. There is vast potential for further, improved research into the effects of Bikram yoga, particularly in unhealthy populations, to better understand intervention-related adaptations and their influence on the progression of chronic disease. Future research should adhere to CONSORT guidelines for better design and reporting to improve research quality in this field.

Neurophysiological and neurocognitive mechanisms underlying the effects of yoga-based practices: towards a comprehensive theoretical framework

During recent decades numerous yoga-based practices (YBP) have emerged in the West, with their aims ranging from fitness gains to therapeutic benefits and spiritual development. Yoga is also beginning to spark growing interest within the scientific community, and yoga-based interventions have been associated with measureable changes in physiological parameters, perceived emotional states, and cognitive functioning. YBP typically involve a combination of postures or movement sequences, conscious regulation of the breath, and various techniques to improve attentional focus. However, so far little if any research has attempted to deconstruct the role of these different component parts in order to better understand their respective contribution to the effects of YBP. A clear operational definition of yoga-based therapeutic interventions for scientific purposes, as well as a comprehensive theoretical framework from which testable hypotheses can be formulated, is therefore needed. Here we propose such a framework, and outline the bottom-up neurophysiological and top-down neurocognitive mechanisms hypothesized to be at play in YBP.

Implementation of an integrative coping and resiliency program for nurses

PURPOSE

To improve resiliency and reduce burnout in nurses through implementation of the Healing Pathways program (University of Maryland School of Medicine, Baltimore). Aims of this study include assessment of feasibility and acceptability and to explore changes in stress, coping, burnout, and mindfulness.

DESIGN

A single-group, pre-, posttest design of an 8-week program in which participants attended weekly sessions that included Reiki, yoga, and meditation. Sample included 8 nurses with 1 advanced practice nurse, all female, ages ranging from 22 to 49 years, experience levels ranging from <1 year to 26 years.

METHODS

Participants completed the Perceived Stress Scale, Coping Self-Efficacy Scale, Maslach Burnout Inventory, and Mindful Attention Awareness Scale before intervention, at last session, and 1 month after last session. Data were analyzed using one-way analysis of variance and qualitative narrative inquiry.

FINDINGS

Improvements were noted in perceived stress, coping, burnout exhaustion subscale, and mindfulness.

CONCLUSION

Healing Pathways was effective at reducing stress and improving coping and mindfulness in nurses.

IMPLICATIONS

Nurses who invest time in self-care techniques including Reiki, yoga, and meditation improve their overall wellbeing and may provide higher-quality patient care. Implementation of an 8-week program in integrative self-care is feasible and important for the health of nurses.

Maladaptive autonomic regulation in PTSD accelerates physiological aging

A core manifestation of post-traumatic stress disorder (PTSD) is a disconnection between physiological state and psychological or behavioral processes necessary to adequately respond to environmental demands. Patients with PTSD experience abnormal oscillations in autonomic states supporting either fight and flight behaviors or withdrawal, immobilization, and dissociation without an intervening “calm” state that would provide opportunities for positive social interactions. This defensive autonomic disposition is adaptive in dangerous and life threatening situations, but in the context of every-day life may lead to significant psychosocial distress and deteriorating social relationships. The perpetuation of these maladaptive autonomic responses may contribute to the development of comorbid mental health issues such as depression, loneliness, and hostility that further modify the nature of cardiovascular behavior in the context of internal and external stressors. Over time, changes in autonomic, endocrine, and immune function contribute to deteriorating health, which is potently expressed in brain dysfunction and cardiovascular disease. In this theoretical review paper, we present an overview of the literature on the chronic health effects of PTSD. We discuss the brain networks underlying PTSD in the context of autonomic efferent and afferent contributions and how disruption of these networks leads to poor health outcomes. Finally, we discuss treatment approaches based on our theoretical model of PTSD.

Age-related changes in cardiovascular system, autonomic functions, and levels of BDNF of healthy active males: role of yogic practice

Aging is associated with decline in cardiovascular, autonomic function, and brain-derived neurotropic factor (BDNF). Reports are scanty regarding whether yoga can improve age-related degenerative changes in healthy active men. This study is designed to appraise the role of yoga in improving age-related degenerative changes in cardiometabolic risk profile, autonomic function, stress, and BDNF. Healthy active males of three age groups (20-29, 30-39, and 40-49 years) were randomly assigned to practice yoga daily 1 h for 3 months. Significantly higher values of heart rate (HR), blood pressure (BP), load in heart (DoP), myocardial oxygen consumption (RPP), and total cholesterol (TC) were noted in senior age group. HR, BP, DoP, RPP, and TC decreased significantly following yogic practice. High frequency (HF), total power (TP), all time domain variables of heart rate variability (HRV), and skin conductance (SC) were significantly decreased with advancement of age. HF, TP, and time domain parameters of HRV and SC increased significantly following yogic practice. Higher levels of catecholamines and low frequency (LF) power of HRV was noted with advancement of age. Levels of catecholamines and LF significantly decreased following yogic practice. Cortisol and adrenocorticotropic hormone (ACTH) level raised in senior age group. BDNF, serotonin, and dopamine were low in higher age group. Significant decrement of cortisol; ACTH; and increment in serotonin, dopamine, and BDNF was noted following yogic practice. This study revealed that yogic practices might help in the prevention of age-related degeneration by changing cardiometabolic risk factors, autonomic function, and BDNF in healthy male.

Yoga and mindfulness as therapeutic interventions for stroke rehabilitation: a systematic review

Aim. This paper reports a systematic review and critical appraisal of the evidence on the effectiveness of behavioral therapies such as yoga and mindfulness practices for stroke rehabilitation. Background. The experience of stroke can have a negative impact on both psychological and physical health and on quality of life. Yoga and relevant practices are promising therapies that have been used with patients with a variety of conditions. In order to draw conclusions on effectiveness for stroke patients, the evidence requires systematic assessment. Methods. A comprehensive search of major biomedical and complementary medicine databases was conducted. Relevant research was categorized by study type and appraised according to study design. Results. Five randomized controlled clinical trials and four single case studies were found. Additionally, one qualitative research study was identified. Studies reported positive results, including improvements in cognition, mood, and balance and reductions in stress. Modifications to different yoga practices make comparison between studies difficult, and a lack of controlled studies precludes any firm conclusions on efficacy. Conclusion. Yoga and mindfulness could be clinically valuable self-administered intervention options for stroke rehabilitation. Further research is needed to evaluate these specific practices and their suitability in stroke rehabilitation.