Regular slow-breathing exercise effects on blood pressure and breathing patterns at rest

Effect of Meditation, Mindfulness-Based Stress Reduction, and Relaxation Techniques as Mind-Body Medicine Practices to Reduce Blood Pressure in Cardiac Patients: A Systematic Review and Meta-Analysis

Elevated blood pressure is one of the major risk factors for cardiovascular diseases. Available evidence on mind-body medicine (MBM) techniques on blood pressure is inconclusive and provides conflicting results. The objective of the current systematic review and meta-analysis is to evaluate the effect of MBM techniques on blood pressure in patients with cardiovascular disease. Randomized control trials (RCTs) done between the years 2000 and 2020 on cardiovascular disease, using MBM techniques such as meditation, mindfulness-based stress reduction and relaxation techniques were searched through electronic databases such as PubMed, Cumulative Index to Nursing & Allied Health (CINAHL), EMBASE and Cochrane Library. Three authors independently performed article selection, data extraction and validation. Meta-analysis was performed using a random effect model and standardized mean difference (SMD) with 95% confidence interval (CI) estimated for the effect size. Fifteen RCTs with 927 patients were included in the meta-analysis. Heterogeneity among the studies was very high for all analyses (I2>94%). For studies comparing systolic blood pressure, MBM interventions show a significant (p=0.01) effect when compared to conventional treatment, an overall estimated effect size of SMD - 0.78 (95% CI: -1.36, -0.20). For studies comparing the diastolic blood pressure, MBM intervention did not show any significant effect when compared to the conventional treatment, an overall effect size of SMD -0.26 (95% CI: -0.91, 0.39). The findings of the meta-analysis suggest that MBM interventions may improve systolic blood pressure alone in patients with cardiac diseases. With high heterogeneity and low quality of the included studies, more robust evidence is required before suggesting MBM as an effective treatment modality for reducing blood pressure in cardiovascular diseases.

Effect of breathing exercises on blood pressure and heart rate: A systematic review and meta-analysis

Background

Breathing exercises have been reported to have positive physiological effects on the body. The incidence of hypertension has become a major risk factor for cardiac complications leading to higher morbidity and mortality. Our aim was to conduct a systematic review and meta-analysis to study the effect of breathing exercises on blood pressure (BP) and heart rate (HR).

Methods

A systematic review and meta-analysis analyzing randomized clinical trials (RCTs) about the effect of breathing exercises on blood pressure was conducted (PROSPERO Registration ID: CRD42022316413). PubMed, ScienceDirect, WebofScience, and Cochrane Library databases were screened for RCTs from January 2017 to September 2022. The main search terms included "breathing exercise", "Pranayam", "Bhramari", "alternate nostril breathing", "deep breathing", "slow breathing", "hypertension", and "high blood pressure". The primary outcome was the value of the systolic blood pressure and diastolic blood pressure after the intervention. The effect on heart rate was also analyzed as a secondary outcome.

Results

A total of 15 studies were included in the meta-analysis. Breathing exercises have a modest but significant effect on decreasing systolic blood pressure (-7.06 [-10.20, -3.92], P = <0.01) and diastolic blood pressure (-3.43 [-4.89, -1.97], P = <0.01) mm Hg. Additionally, breathing exercises were also observed to cause a significant decrease in the heart rate (-2.41 [-4.53, -0.30], P = 0.03) beats/minute.

Conclusion

In a comprehensive systematic review and meta-analysis of breathing exercises and its effect on BP and HR, there is a moderate but significant positive effect. The studies are not deprived of bias.

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.

Signaling pathways in vascular function and hypertension: molecular mechanisms and therapeutic interventions

Hypertension is a global public health issue and the leading cause of premature death in humans. Despite more than a century of research, hypertension remains difficult to cure due to its complex mechanisms involving multiple interactive factors and our limited understanding of it. Hypertension is a condition that is named after its clinical features. Vascular function is a factor that affects blood pressure directly, and it is a main strategy for clinically controlling BP to regulate constriction/relaxation function of blood vessels. Vascular elasticity, caliber, and reactivity are all characteristic indicators reflecting vascular function. Blood vessels are composed of three distinct layers, out of which the endothelial cells in intima and the smooth muscle cells in media are the main performers of vascular function. The alterations in signaling pathways in these cells are the key molecular mechanisms underlying vascular dysfunction and hypertension development. In this manuscript, we will comprehensively review the signaling pathways involved in vascular function regulation and hypertension progression, including calcium pathway, NO-NOsGC-cGMP pathway, various vascular remodeling pathways and some important upstream pathways such as renin-angiotensin-aldosterone system, oxidative stress-related signaling pathway, immunity/inflammation pathway, etc. Meanwhile, we will also summarize the treatment methods of hypertension that targets vascular function regulation and discuss the possibility of these signaling pathways being applied to clinical work.

Breathing exercise for hypertensive patients: A scoping review

Background: Non-pharmacological management of hypertension includes weight loss, alcohol and sodium restriction, regular exercise, and relaxation. In people with overweight hypertension, systolic blood pressure (SBP) and diastolic blood pressure (DBP) can be decreased via exercise and weight loss together. Breathing exercises are one method of relaxing. Objectives: The aim of this scoping review is to map the information that is currently available about the advantages of breathing exercises in decreasing blood pressure in hypertension patients. Methods: This scoping review adheres to Arksey and O'Malley's framework, which entails identifying review questions, seeking pertinent evidence, choosing pertinent studies, mapping data, and discussing, concluding, and reporting the findings. The PRISMA flowchart is used to show how the evidence search process works. Results: As a result, 339 articles in total were retrieved from the three databases. 20 papers total were included in this review after screening. In 14 of the 20 investigations, participants with stage 1 and stage 2 essential hypertension, two with pre-hypertension, and four with Isolated Systolic Hypertension (ISH) were studied. The respondents' ages ranged from 18 to 75. The systolic blood pressure declined by 4-54.22 mmHg, while the diastolic blood pressure dropped by 3-17 mmHg. Conclusion: Slow breathing can be used as an alternate, non-pharmacological therapy for hypertension individuals to reduce blood pressure. Systematic Review Registration: (https://osf.io/ta9u6/).

Are home-based exercises effective to reduce blood pressure in hypertensive adults? A systematic review

Sedentarism and chronic non-communicable diseases have been a worldwide health problem that is drastically exacerbated by the COVID-19 pandemic social impacts. Home-based exercises are widely encouraged during social isolation to counterbalance the physical inactive impacts. Although, in the context of hypertension, are home-based exercises effective in blood pressure controlling? Our objective is to conduct a systematic review of high-quality controlled trials comparing the possible effects of different types of home-based exercises in hypertensive patients. The literature search was carried out in three scientific databases: Medline, Europe PMC, and Lilacs. Articles were included following three criteria: analyzing the effect of home-based exercise programs on blood pressure in treated and untreated hypertensive patients; exercises must perform at home and on the frequency, intensity, time, and type (FITT) principle, and the articles were published in English. From the qualitative analysis of 27 original trials screened through 451 identified studies, the main results are the following: 1) both endurance, isometric strength, and respiratory home-based exercise programs were efficient to decrease blood pressure in hypertensive patients; 2) differences in methodological approaches regarding FITT components, distinct blood pressure values at baseline and specific underlying mechanisms must be considered as a potential bias of each home-based interventions. In conclusion, endurance, isometric strength, and breathing home-based programs seems to be effective to reduce blood pressure in hypertensive patients. However, further randomized controlled trials and mechanistic studies must be performing to guide evidence-based recommendations of home-based exercises as antihypertensive therapy.

Time-dependent effects of inspiratory muscle training and detraining on cardiac autonomic control in older women

Inspiratory muscle training improved maximal inspiratory pressure (MIP) and vagal-mediated heart rate variability (HRV) in older women. However, it is unknown what occurs if the training is discontinued (detraining protocol). The aim of this study was to investigate the IMT and detraining effects on resting HRV in older women. Twelve healthy older women (60-72 yrs) enrolled in home-based IMT at 50% MIP (IMT-group) or placebo at 5% MIP (Sham-group) protocol for 4 weeks using a mechanical pressure threshold loading device. The participants were not engaged in any other exercise protocol at that time. During IMT and Sham interventions, the inspiratory load was adjusted weekly by the actual MIP and resting heart rate variability (HRV) evaluated. After training cessation (4 weeks of detraining), participants returned to the lab for HRV and MIP recordings. Adherence to IMT was superior to 95%. IMT increased MIP (23 ± 8 cmH₂O) and vagal-mediated HRV (normalized HF; 37 ± 8%), following by the reduction of sympatho-vagal balance (LF/HF), from the second week to the end of the protocol compared to sham-group. After detraining, IMT-group reduced MIP (-23 ± 8 cmH₂O) and vagal-mediated HRV (normalized HF; -38 ± 14%) returning to baseline values. In conclusion, MIP and vagal-HRV improvements induced by IMT were reversed by four weeks of detraining.

Can respiratory muscle training change the blood pressure levels in hypertension? A systematic review with meta-analysis

The aim was to systematically review randomized controlled trials investigating the effects of respiratory training on blood pressure control in hypertensive individuals. Systematic review with meta-analysis was coducted following the guidelines from PRISMA statement. Searches for randomized controlled trials were performed in four electronic databases (PubMed, Cochrane Library, SCOPUS, and PEDro). Studies were included if they were randomized controlled trials that examined the impact of respiratory training on blood pressure of individuals with systemic arterial hypertension and the patients had no other associated disease. Eight studies were included for final analysis (total of 270 participants; 18-85 years) and presented an average score of 6.25 in the PEDro scale, being considered of high methodological quality. The meta-analysis showed a reduction in systolic and diastolic blood pressure for respiratory training when the load was applied [-15.72 (-18.63; -12.81) and -7.08 (-9.03; -5.13) mmHg, respectively]. There was also a reduction in systolic, but not in diastolic blood pressure when the training was performed without load [-5.08 (-7.49; -2.66) and -1.04 (-2.55; +0.46) mmHg, respectively]. The respiratory training has a positive effect in BP in hypertensive patients, however, only when performed with load seems to be able to promote some beneficial effect on diastolic blood pressure reduction.

Cardiac Autonomic Nervous System Activity during Slow Breathing in Supine Position

The purpose of this study is to clarify cardiac autonomic nervous system activity during slow breathing exercises in a supine position. Eighteen healthy young males were participated. Heart rate variability was measured for 5 minutes at rest, 5 minutes at slow breathing, and then 5 minutes at rest. As a result, the LF/HF ratio increased with slow breathing, but HF value did not change. We suggest that the increased LF/HF ratio may be due to increased airway resistance. Cardiac autonomic nervous system activity during slow breathing in the supine position was revealed.

Effects of diaphragmatic deep breathing exercises on prehypertensive or hypertensive adults: A literature review

Diaphragmatic breathing, a deep breathing technique, has been reported to improve autonomic function by reducing sympathetic activity and increasing baroreflex sensitivity. This literature review aimed to (1) examine the effects of diaphragmatic breathing on physiological and psychological measures in prehypertensive or hypertensive adults and to (2) determine the appropriate length, frequency, and duration of an effective diaphragmatic breathing exercise in the management of prehypertension and hypertension. Relevant studies were searched using electronic databases, and 13 studies that met the inclusion criteria were included. The synthesis of the findings revealed that voluntary diaphragmatic deep breathing resulted in decreased of systolic and diastolic blood pressures, reduced heart rate, a relaxing effect, and reduced anxiety in hypertensive or prehypertensive individuals. It is concluded that voluntary diaphragmatic breathing at <10 or 6 breaths per minute for 10 min twice a day for 4 weeks was effective in producing positive outcomes. The results of this review provide directions for related interventions and future research.

Ethnicity Differences in Sleep Changes Among Prehypertensive Adults Using a Smartphone Meditation App: Dose-Response Trial

Background

African Americans (AAs) experience greater sleep quality problems than non-Hispanic Whites (NHWs). Meditation may aid in addressing this disparity, although the dosage levels needed to achieve such benefits have not been adequately studied. Smartphone apps present a novel modality for delivering, monitoring, and measuring adherence to meditation protocols.

Objective

This 6-month dose-response feasibility trial investigated the effects of a breathing awareness meditation (BAM) app, Tension Tamer, on the secondary outcomes of self-reported and actigraphy measures of sleep quality and the modulating effects of ethnicity of AAs and NHWs.

Methods

A total of 64 prehypertensive adults (systolic blood pressure <139 mm Hg; 31 AAs and 33 NHWs) were randomized into 3 different Tension Tamer dosage conditions (5,10, or 15 min twice daily). Sleep quality was assessed at baseline and at 1, 3, and 6 months using the Pittsburgh Sleep Quality Index (PSQI) and 1-week bouts of continuous wrist actigraphy monitoring. The study was conducted between August 2014 and October 2016 (IRB #Pro00020894).

Results

At baseline, PSQI and actigraphy data indicated that AAs had shorter sleep duration, greater sleep disturbance, poorer efficiency, and worse quality of sleep (range P=.03 to P<.001). Longitudinal generalized linear mixed modeling revealed a dose effect modulated by ethnicity (P=.01). Multimethod assessment showed a consistent pattern of NHWs exhibiting the most favorable responses to the 5-min dose; they reported greater improvements in sleep efficiency and quality as well as the PSQI global value than with the 10-min and 15-min doses (range P=.04 to P<.001). Actigraphy findings revealed a consistent, but not statistically significant, pattern in the 5-min group, showing lower fragmentation, longer sleep duration, and higher efficiency than the other 2 dosage conditions. Among AAs, actigraphy indicated lower sleep fragmentation with the 5-min dose compared with the 10-min and 15-min doses (P=.03 and P<.001, respectively). The 10-min dose showed longer sleep duration than the 5-min and 15-min doses (P=.02 and P<.001, respectively). The 5-min dose also exhibited significantly longer average sleep than the 15-min dose (P=.03).

Conclusions

These findings indicate the need for further study of the potential modulating influence of ethnicity on the impact of BAM on sleep indices and user-centered exploration to ascertain the potential merits of refining the Tension Tamer app with attention to cultural tailoring among AAs and NHWs with pre-existing sleep complaints.

Nonpharmacologic Interventions for Reducing Blood Pressure in Adults With Prehypertension to Established Hypertension

Background

Nonpharmacologic interventions that modify lifestyle can lower blood pressure (BP) and have been assessed in numerous randomized controlled trials and pairwise meta‐analyses. It is still unclear which intervention would be most efficacious.

Methods and Results

Bayesian network meta‐analyses were performed to estimate the comparative effectiveness of different interventions for lowering BP. From 60 166 potentially relevant articles, 120 eligible articles (14 923 participants) with a median follow‐up of 12 weeks, assessing 22 nonpharmacologic interventions, were included. According to the surface under the cumulative ranking probabilities and Grading of Recommendations Assessment, Development and Evaluation (GRADE) quality of evidence, for adults with prehypertension to established hypertension, high‐quality evidence indicated that the Dietary Approach to Stop Hypertension (DASH) was superior to usual care and all other nonpharmacologic interventions in lowering systolic BP (weighted mean difference, 6.97 mm Hg; 95% credible interval, 4.50–9.47) and diastolic BP (weighted mean difference, 3.54 mm Hg; 95% credible interval, 1.80–5.28). Compared with usual care, moderate‐ to high‐quality evidence indicated that aerobic exercise, isometric training, low‐sodium and high‐potassium salt, comprehensive lifestyle modification, breathing‐control, and meditation could lower systolic BP and diastolic BP. For patients with hypertension, moderate‐ to high‐quality evidence suggested that the interventions listed (except comprehensive lifestyle modification) were associated with greater systolic BP and diastolic BP reduction than usual care; salt restriction was also effective in lowering both systolic BP and diastolic BP. Among overweight and obese participants, low‐calorie diet and low‐calorie diet plus exercise could lower more BP than exercise.

Conclusions

DASH might be the most effective intervention in lowering BP for adults with prehypertension to established hypertension. Aerobic exercise, isometric training, low‐sodium and high‐potassium salt, comprehensive lifestyle modification, salt restriction, breathing‐control, meditation and low‐calorie diet also have obvious effects on BP reduction.

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

BACKGROUND

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

OBJECTIVES

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

The effects of slow loaded breathing training on exercise blood pressure in isolated systolic hypertension

OBJECTIVES

Slow loaded breathing training has been shown to reduce resting blood pressure (BP) in isolated systolic hypertension (ISH), but it is not known whether this also reduces their exaggerated BP responses to exercise.

METHODS

The study was a randomized controlled trial with block allocation stratified by sex. Twenty ISH patients (68 ± 5 yrs, 11 males) were randomized with one group undertaking 8-weeks training with slow loaded breathing (SLB: 25% maximum inspiratory pressure, 6 breaths per minute, 60 breaths every day) or deep breathing control (CON), with 8 weeks follow-up. Outcome measures were home BP and heart rate (HR) with laboratory measures of BP and HR responses to static handgrip and dynamic arm cranking exercise. Data were compared with a two-week run-in baseline.

RESULTS

Home systolic BP fell by 22 mmHg (20-23; mean, 95% CI), diastolic BP by 9 mmHg (7-11), and HR by 12 bpm (9-15; all p < .001) as a result of SLB training. Systolic BP at the end of 2-min isometric handgrip was 189 ± 10 mmHg (mean, SD) before training and 157 ± 6 mmHg following SLB training. After 4-min arm exercise, systolic BP, measured at the ankle, was reduced from 243 ± 8 mmHg during the run-in period to 170 ± 15 mmHg after SLB training with no change for CON. The reduction in exercise BP, in both types of exercise, was partly due to a reduction in resting BP and to a smaller increase above resting. Systolic and pulse pressures remained below run-in values 8 weeks after the end of SLB training, and BP response to handgrip exercise remained below run-in values at 4 weeks after SLB training.

CONCLUSIONS

SLB not only reduces resting BP in ISH but also the responses to both static and dynamic exercise, potentially reducing the negative aspect of exercise for cardiovascular health.

A randomized cross-over study on the blood pressure lowering effect of the combined passive head-up and -down movement with Device-Guided slow breathing

Purpose: Baroreflex emerges as a therapeutic target of hypertension. We investigated blood pressure (BP) lowering effect of the combined passive head-up and -down movement with device-guided slow breathing in untreated mild hypertension or high-normal BP. Methods: In a randomized, cross-over trial, untreated subjects with an ambulatory systolic/diastolic BP of 125-140/80-90 mmHg and a clinic BP of 130-150/80-90 mmHg were randomized to intervention treatment with head movement and slow breathing or sham control, and then crossed over. Both treatments consisted of 1-week preparation, 2-week treatment, and 1-week recovery. During the 2-week treatment, subjects were treated for a session of 20 min/day. BP, pulse rate and respiration were measured before and after each treatment session. Ambulatory BP monitoring was performed at baseline and the end of the 2-week treatments' period, and home BP monitoring in the morning and evening for the whole 8-week follow-up period. Results: 14 subjects completed the study. The intervention treatment, compared to control, reduced respiration rate by -2.1 breaths/min (95% CI -2.9 to -1.2, p = .0001), but not clinic BP and pulse rate (p ≥ .67). The intervention treatment, compared to control, significantly reduced nighttime systolic/diastolic blood pressure by -5.63/-3.82 mm Hg (p ≤ .01) but not 24-h or daytime ambulatory blood pressure (p ≥ .69). Home BP decreased with the intervention treatment, but the between-treatment difference was not statistically significant (p ≥ .27). Conclusions: The combined head movement with slow breathing did not influence 24-h BP, but reduced nighttime BP in untreated mild hypertension or high-normal BP.

Meditation smartphone application effects on prehypertensive adults' blood pressure: Dose-response feasibility trial

OBJECTIVE

Essential hypertension (EH) is the most common chronic disease in the United States and a major cause of morbidity and mortality. Lifestyle interventions (e.g., diet, exercise, stress management) to reduce blood pressure (BP) are often complex with varying effectiveness. Breathing awareness meditation (BAM) is a stress management strategy with encouraging effects on BP, though widespread dissemination is hampered by the lack of an easy-to-use methodology to train and monitor BAM practices. A smartphone application (Tension Tamer [TT]) that implements BAM and tracks adherence has shown promise in addressing these gaps. This 6-month dose-response feasibility trial evaluated effects of the app on BP to further optimize BAM user guidelines.

METHODS

Sixty-four adults with prehypertension were randomized to complete TT-guided BAM sessions for 5-, 10-, or 15-min intervals twice daily over 6 months. Continuous heart rate readings derived from the phone's video camera via reflective photoplethysmography were used as feedback and as an index of time-stamped adherence. Outcomes (resting BP, HR) were collected at baseline, 1-, 3-, and 6-months.

RESULTS

Mixed modeling results showed a significant time effect for systolic BP (SBP) with a dose-response effect at Months 3 and 6. Adherence declined over time and was lowest in the 15-min dose condition, though SBP reductions were maintained. Generally, adherence was negatively associated with dose as the study progressed.

CONCLUSIONS

Smartphone-implemented BAM appears to reduce SBP and can be a low-cost method to reach large populations. (PsycINFO Database Record

Just Breathe

Motivated by the idea that slow breathing practices could transform the automobile commute from a depleting, mindless activity into a calming, mindful experience, we introduce the first guided slow breathing intervention for drivers. We describe a controlled in-lab experiment (N=24) that contrasts the effectiveness and impact of haptic and voice guidance modalities at slowing drivers' breathing pace, which is a known modulator of stress. The experiment was conducted in two simulated driving environments (city, highway) while driving in one of two driving modes (autonomous, manual). Results show that both haptic and voice guidance systems can reduce drivers' breathing rate and provide a sustained post-intervention effect without affecting driving safety. Subjectively, most participants (19/24) preferred the haptic stimuli as they found it more natural to follow, less distracting, and easier to engage and disengage from, compared to the voice stimuli. Finally, while most participants found guided breathing to be a positive experience, a few participants in the autonomous driving condition found slow breathing to be an unusual activity inside the car. In this paper, we discuss such considerations, offer guidelines for designing in-car breathing interventions, and propose future research that extends our work to on-road studies. Altogether, this paper serves as foundational work on guided breathing interventions for automobile drivers.

Breathing Training for Older Patients with Controlled Isolated Systolic Hypertension

INTRODUCTION

Isolated systolic hypertension (ISH) is very common but difficult to manage with conventional medication. We investigated whether slow breathing training, with and without an inspiratory load, could reduce the resting blood pressure of older well-managed ISH patients.

METHODS

Thirty ISH patients (66 ± 4 yr) were randomized into loaded breathing (six breaths per min, 18 cm H2O), unloaded breathing (six breaths per min, no load), or control (normal breathing) groups. After a 2-wk run-in, loaded and unloaded groups trained at home for 30 min every day for 8 wk. Morning home blood pressure and heart rate were measured daily throughout the study. At the end of training, all participants reverted to normal breathing, and blood pressure and heart rate were recorded for a further 8 wk.

RESULTS

Compared to the pretraining run-in period, systolic blood pressure was reduced by 18 ± 7 and 11 ± 4 mm Hg for loaded and unloaded groups, respectively (P < 0.001), the reduction being significantly larger for the loaded group (P < 0.05) after 8-wk training. There were no changes in the control group. After the end of training, systolic blood pressure remained below pretraining levels for a further 6 wk for the loaded group but for only 2 wk with the unloaded group. There was a small nonsignificant reduction in diastolic blood pressure with training, as there was for heart rate. Pulse pressures were reduced by 11 ± 5 and 5 ± 6 mm Hg for loaded and unloaded groups, respectively (P < 0.01).

CONCLUSION

Slow breathing training, especially with an inspiratory load, is very effective in reducing resting systolic and pulse pressures and could be a valuable adjunct in the management of ISH.

Effects of long term device-guided slow breathing on sympathetic nervous activity in hypertensive patients: a randomized open-label clinical trial

PURPOSE

Device-guided slow breathing (DGB) is indicated as nonpharmacological treatment for hypertension. The sympathetic nerve activity (SNA) reduction may be one of the mechanisms involved in blood pressure (BP) decrease. The aim of this study is to evaluate the long-term use of DGB in BP and SNA.

SUBJECTS AND METHODS

Hypertensive patients were randomized to listen music (Control Group-CG) or DGB (aim to reduce respiratory rate to less than 10 breaths/minute during 15 minutes/day for 8 weeks). Before and after intervention ambulatory blood pressure monitoring (ABPM), catecholamines and muscle sympathetic nerve activity (MSNA) by microneurography were performed.

RESULTS

17 volunteers in the DGB and 15 in the CG completed the study. There was no change in office BP before and after intervention in both groups. There was a reduction in systolic and diastolic BP in the awake period by ABPM only in the CG (131 ± 10/92 ± 9 vs 128 ± 10/88 ± 8mmHg, p < 0.05). In relation to SNA, no difference in catecholamines was observed. In the volunteers who had a microneurography record, there was no change the MSNA (bursts/minute): DGB (17(15-28) vs 19(13-22), p = 0.08) and CG (22(17-23) vs 22(18-24), p = 0.52).

CONCLUSION

Long-term DGB did not reduce BP, catecholamines levels or MSNA in hypertensive patients. ClinicalTrials.gov identifier: NCT01390727.

Effect of respiratory pattern on automated clinical blood pressure measurement: an observational study with normotensive subjects

BACKGROUND

It has been reported that deep breathing could reduce blood pressures (BP) in general. It is also known that BP is decreased during inhalation and increased during exhalation. Therefore, the measured BPs could be potentially different during deep breathing with different lengths of inhalation and exhalation. This study aimed to quantitatively investigate the effect of different respiratory patterns on BPs.

METHODS

Forty healthy subjects (20 males and 20 females, aged from 18 to 60 years) were recruited. Systolic and diastolic BPs (SBP and DBP) were measured using a clinically validated automated BP device. There were two repeated measurement sessions for each subject. Within each session, eight BP measurements were performed, including 4 measurements during deep breathing with different respiratory patterns (Pattern 1: 4.5 s vs 4.5 s; Patter 2: 6 s vs 2 s; Pattern 3: 2 s vs 6 s; and Pattern 4: 1.5 s vs 1.5 s, respectively for the durations of inhalation and exhalation) and additional 4 measurements from 1 min after the four different respiratory patterns. At the beginning and end of the two repeated measurement sessions, there were two baseline BP measurements under resting condition.

RESULTS

The key experimental results showed that overall automated SBP significantly decreased by 3.7 ± 5.7 mmHg, 3.9 ± 5.2 mmHg, 1.7 ± 5.9 mmHg and 3.3 ± 5.3 mmHg during deep breathing, respectively for Patterns 1, 2, 3 and 4 (all p < 0.001 except p < 0.05 for Pattern 3). Similarly, the automated DBPs during deep breathing in pattern 1, 2 and 4 decreased by 3.7 ± 5.0 mmHg, 3.7 ± 4.9 mmHg and 4.6 ± 3.9 mmHg respectively (all p < 0.001, except in Pattern 3 with a decrease of 1.0 ± 4.3 mmHg, p = 0.14). Correspondingly, after deep breathing, automated BPs recovered back to normal with no significant difference in comparison with baseline BP (all p > 0.05, except for SBP in Pattern 4).

CONCLUSIONS

In summary, this study has quantitatively demonstrated that the measured automated BPs decreased by different amounts with all the four deep breathing patterns, which recovered back quickly after these single short-term interventions, providing evidence of short-term BP decrease with deep breathing and that BP measurements should be performed under normal breathing condition.

The effect of slow-loaded breathing training on the blood pressure response to handgrip exercise in patients with isolated systolic hypertension

Isolated systolic hypertension (ISH) is the most common form of hypertension in older people. It is characterized by increased resting systolic blood pressure (sBP) and increased sBP in response to exercise. It has previously been shown that slow breathing training reduces resting sBP, and the objective of the present study was to determine whether it also reduced the blood pressure response to static handgrip exercise. ISH patients aged between 60 and 74 years were randomly divided into a control group (10 subjects, 4 of which were male) that breathed normally and a trained group (10 subjects, 4 of which were male) that trained daily for 8 weeks by slow breathing against an inspiratory resistance of 18 cmH₂O. Before and immediately after training, subjects underwent a 2-min handgrip test (30% max) followed by 2 min of post-exercise circulatory occlusion (PECO) to assess metaboreflex activity. Training reduced sBP by 10.6 mm Hg (95% confidence interval (CI), -16 to -5 mm Hg, P=0.004), but changes were not observed in the control group. The peak exercise sBP was reduced by 23 mm Hg (95% CI, -16 to -31 mm Hg, P<0.001), while the increase in the sBP above resting was reduced by 12.6 mm Hg (95% CI, -6.9 to -18.2 mm Hg, P=0.002). The sBP during PECO was reduced by 8.9 mm Hg (95% CI, -4 to -14 mm Hg, P=0.008), which is indicative of reduced metaboreflex activity; no such change was observed in the control group. The results demonstrate that conventional treatment of older patients with ISH may be improved in two ways by slow breathing training: resting sBP may be reduced by 10 mm Hg, more than can be achieved by conventional pharmacological therapies, while the response to static exercise may be reduced by approximately twice this value.

Device-Guided Breathing for Hypertension: a Summary Evidence Review

Persistently raised blood pressure is one of the major risk factors for diseases such as myocardial infarction and stroke. Uncontrolled hypertension is also associated with high rates of mortality, particularly in middle and high-income countries. Lifestyle factors such as poor diet, obesity, physical inactivity and smoking are all thought to contribute to the development of hypertension. As a result, the management of hypertension should begin with modifying these lifestyle factors. Beyond this, drug interventions are used as the predominant form of management. However, adherence to medications can be highly variable, medication side effects are common, and may require regular monitoring or, in some individuals may be ineffective. Therefore, additional non-pharmacologic interventions that lower blood pressure may be advantageous when combined with lifestyle modifications. Such interventions may include relaxation therapies such as slow breathing exercises, which can be initiated by means of specific devices. The technique of device-guided breathing (DGB) has been considered by guideline developers in the management of hypertension. One specific device, the Resperate, has received US FDA and UK NHS approval over the last few years. In this review, we summarise the evidence base on efficacy and find that although some clinical trials exist that demonstrate a BP-lowering effect, others do not. There is currently insufficient evidence from pooled data to recommend the routine use of device-guided breathing in hypertensive patients.

Effects of slow and regular breathing exercise on cardiopulmonary coupling and blood pressure

Investigation of the interaction between cardiovascular variables and respiration provides a quantitative and noninvasive approach to assess the autonomic control of cardiovascular function. The aim of this paper is to investigate the changes of cardiopulmonary coupling (CPC), blood pressure (BP) and pulse transit time (PTT) during a stepwise-paced breathing (SPB) procedure (spontaneous breathing followed by paced breathing at 14, 12.5, 11, 9.5, 8 and 7 breaths per minute, 3 min each) and gain insights into the characteristics of slow breathing exercises. RR interval, respiration, BP and PTT are collected during the SPB procedure (48 healthy subjects, 27 ± 6 years). CPC is assessed through investigating both the phase and amplitude dynamics between the respiration-induced components from RR interval and respiration by the approach of ensemble empirical mode decomposition. It was found that even though the phase synchronization and amplitude oscillation of CPC were both enhanced by the SPB procedure, phase coupling does not increase monotonically along with the amplitude oscillation during the whole procedure. Meanwhile, BP was reduced significantly by the SPB procedure (SBP: from 122.0 ± 13.4 to 114.2 ± 14.9 mmHg, p < 0.001, DBP: from 82.2 ± 8.6 to 77.0 ± 9.8 mmHg, p < 0.001, PTT: from 172.8 ± 20.1 to 176.8 ± 19.2 ms, p < 0.001). Our results demonstrate that the SPB procedure can reduce BP and lengthen PTT significantly. Compared with amplitude dynamics, phase dynamics is a different marker for CPC analysis in reflecting cardiorespiratory coherence during slow breathing exercise. Our study provides a methodology to practice slow breathing exercise, including the setting of target breathing rate, change of CPC and the importance of regular breathing. The applications and usability of the study results have also been discussed.

Efficacy of paced breathing for insomnia: enhances vagal activity and improves sleep quality

Fourteen self-reported insomniacs (SRI) and 14 good sleepers (GS) had their cardiac neuronal activity assessed by heart rate variability (HRV) under controlled respiration at a slow frequency rate of 0.1 Hz, and a forced rate of 0.2 Hz during daytime rest. Nighttime sleep was measured by polysomnography. The SRI showed depressed high frequency power of HRV compared to the GS. An increased total power of HRV was observed among the SRI during slow, paced breathing compared with spontaneous breathing and 0.2 Hz. Sleep onset latency, number of awakenings, and awakening time during sleep were decreased and sleep efficiency was increased if SRI practiced slow, paced breathing exercises for 20 min before going to sleep. Our results indicate that there is autonomic dysfunction among insomniacs, especially in relation to vagal activity; however, this decreased vagal activity can be facilitated by practicing slow, paced breathing, thereby improving sleep quality.

Device-guided breathing exercises for the treatment of hypertension: An overview

The American Heart Association considers device-guided breathing as a reasonable treatment modality in their statement on non-pharmacological options for lowering blood pressure. This review discusses all randomized controlled trials that have investigated the effects of device-guided breathing on blood pressure in patients with hypertension. Thirteen studies were included in this review. In total, 627 patients were included, of which 365 patients were allocated to device-guided breathing. Only 6 studies used acceptable control groups: listening to music, meditative relaxation exercises, or a sham-device. Two sponsored trials showed beneficial effects of device-guided breathing, both used listening to music as a control group. The remaining 4 studies, which had no employees of the manufacturer listed as co-author, observed no beneficial effects on blood pressure. There is only 1 study that used a sham device as a control group. All other studies were to some extend methodologically flawed. Based on the studies with an acceptable methodological quality, there is no clear evidence supporting a short-term beneficial effect on blood pressure by using device-guided breathing.

Effects of acute and long-term slow breathing exercise on muscle sympathetic nerve activity in untreated male patients with hypertension

OBJECTIVE

Acute slow breathing (SLOWB) affects sympathetic cardiovascular regulation, but its long-term effects are unknown. Using device-guided breathing we explored short-term and long-term SLOWB effects on blood pressure (BP), heart rate (HR) and muscle sympathetic nerve activity (MSNA) in essential hypertension.

METHODS

We measured BP, HR and MSNA in 10 hypertensive individuals at rest, during laboratory stressors, before and after acute SLOWB, and 8 weeks after SLOWB exercise. Twelve matched hypertensive controls underwent a similar protocol excluding SLOWB intervention. Office and 24-h BP were obtained at baseline and at follow-up.

RESULTS

Acute SLOWB had no influence on BP, HR, but decreased MSNA (P < 0.01). BP, HR, MSNA responses to handgrip were comparable before and after acute SLOWB. Acute SLOWB tended to reduce SBP (P = 0.09), HR (P = 0.08), but not MSNA (P = 0.20) responses to mental stress. Long-term SLOWB decreased office SBP (P < 0.001), DBP (P < 0.01), HR (P = 0.004), but not 24-h BP. Resting MSNA was unchanged after long-term SLOWB (P = 0.68). Long-term SLOWB did not influence BP, HR or MSNA responses to handgrip and cold pressor, but reduced SBP (P = 0.03), HR (P = 0.03) responses to mental stress without MSNA changes. In controls BP, HR, MSNA responses to laboratory stressors remained unchanged at baseline and at follow-up.

CONCLUSION

In essential hypertension, MSNA is reduced during acute SLOWB, but remains unaltered following long-term SLOWB. Long-term SLOWB reduces office, but not ambulatory BP and HR. SLOWB attenuates cardiovascular response to mental stress, but not physical stressors. These findings may be indicative of beneficial SLOWB effects on stress reduction in essential hypertension.

Beyond medications and diet: alternative approaches to lowering blood pressure: a scientific statement from the american heart association

Many antihypertensive medications and lifestyle changes are proven to reduce blood pressure. Over the past few decades, numerous additional modalities have been evaluated in regard to their potential blood pressure-lowering abilities. However, these nondietary, nondrug treatments, collectively called alternative approaches, have generally undergone fewer and less rigorous trials. This American Heart Association scientific statement aims to summarize the blood pressure-lowering efficacy of several alternative approaches and to provide a class of recommendation for their implementation in clinical practice based on the available level of evidence from the published literature. Among behavioral therapies, Transcendental Meditation (Class IIB, Level of Evidence B), other meditation techniques (Class III, Level of Evidence C), yoga (Class III, Level of Evidence C), other relaxation therapies (Class III, Level of Evidence B), and biofeedback approaches (Class IIB, Level of Evidence B) generally had modest, mixed, or no consistent evidence demonstrating their efficacy. Between the noninvasive procedures and devices evaluated, device-guided breathing (Class IIA, Level of Evidence B) had greater support than acupuncture (Class III, Level of Evidence B). Exercise-based regimens, including aerobic (Class I, Level of Evidence A), dynamic resistance (Class IIA, Level of Evidence B), and isometric handgrip (Class IIB, Level of Evidence C) modalities, had relatively stronger supporting evidence. It is the consensus of the writing group that it is reasonable for all individuals with blood pressure levels >120/80 mm Hg to consider trials of alternative approaches as adjuvant methods to help lower blood pressure when clinically appropriate. A suggested management algorithm is provided, along with recommendations for prioritizing the use of the individual approaches in clinical practice based on their level of evidence for blood pressure lowering, risk-to-benefit ratio, potential ancillary health benefits, and practicality in a real-world setting. Finally, recommendations for future research priorities are outlined.

Do cardiorespiratory variables predict the antinociceptive effects of deep and slow breathing?

Deep and slow breathing (DSB) is a central part of behavioral exercises used for acute and chronic pain management. Its mechanisms of action are incompletely understood.

OBJECTIVES

1) To test the effects of breathing frequency on experimental pain perception in a dose dependent fashion. 2) To test the effects of breathing frequency on cardiorespiratory variables hypothesized to mediate DSB analgesia. 3) To determine the potential of the cardiorespiratory variables to mediate antinociceptive DSB effects by regression analysis.

DESIGN

Single-blind, randomized, crossover trial.

SUBJECTS

Twenty healthy participants.

INTERVENTIONS

Visually paced breathing at 0.14 Hz, 0.10 Hz, 0.06 Hz, and resting frequency.

OUTCOME MEASURES

Cardiorespiratory variables: RR-interval (= 60 seconds/heart rate), standard deviation of the RR-interval (SDRR), and respiratory CO2 . Experimental pain measures: heat pain thresholds, cold pain thresholds, pain intensity ratings, and pain unpleasantness ratings.

RESULTS

1) There was no effect of DSB frequency on experimental pain perception. 2) SDRR and respiratory CO2 were significantly modulated by DSB frequency, while RR-interval was not. 3) Baseline-to-DSB and session-to-session differences in RR-interval significantly predicted pain perception within participants: Prolonged RR-intervals predicted lower pain ratings, while shortened RR-intervals predicted higher pain ratings. SDRR and respiratory CO2 were not found to predict pain perception.

CONCLUSIONS

The present study could not confirm hypotheses that the antinociceptive effects of DSB are related to changes in breathing frequency, heart rate variability, or hypoventilation/hyperventilation when applied as a short-term intervention. It could confirm the notion that increased cardiac parasympathetic activity is associated with reduced pain perception.

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.

Device-guided breathing exercises in the control of human blood pressure: systematic review and meta-analysis

OBJECTIVE

To evaluate whether device-guided breathing (DGB) lowers blood pressure (BP) in adults.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched Medline (1950-2010), Embase (1980-2010), the Cochrane Library including the Cochrane Central register of Controlled Trials (CENTRAL), AMED (1985-2010), CINAHL (1980-2010) and the Current Controlled Trials registry (as of October 2010).

OUTCOME MEASURES

Primary outcomes included the mean change in SBP and DBP. Secondary outcomes included change in heart rate, quality of life, compliance with the device and any side effects of the device.

RESULTS

We included eight trials of the Resperate device (InterCure Ltd, Lod, Israel), consisting of 494 adult patients. Use of this device resulted in significantly reduced SBP by 3.67 mmHg [95% confidence interval (CI) = -5.99 to -1.39; P = 0.002] and decreased DBP by 2.51 mmHg (95% CI = -4.15 to -0.87; P = 0.003). However, sensitivity analysis was carried out excluding the five trials sponsored by or involving the manufacturers of the device, which revealed no overall effect on BP using the device. The maximum trial duration was 9 weeks and no overall effect was seen on heart rate or quality of life using the device.

CONCLUSION

There is evidence that short-term use of DGB may reduce both DBP and DBP. However, five of the eight trials were sponsored by or involved the manufactures of the device. When these trials were excluded we found no overall effect. We conclude that longer term, independent trials are required to validate this intervention.

The sympathetic nervous system and blood pressure in humans: implications for hypertension

A neurogenic component to primary hypertension (hypertension) is now well established. Along with raised vasomotor tone and increased cardiac output, the chronic activation of the sympathetic nervous system in hypertension has a diverse range of pathophysiological consequences independent of any increase in blood pressure. This review provides a perspective on the actions and interactions of angiotensin II, inflammation and vascular dysfunction/brain hypoperfusion in the pathogenesis and progression of neurogenic hypertension. The optimisation of current treatment strategies and the exciting recent developments in the therapeutic targeting of the sympathetic nervous system to control hypertension (for example, catheter-based renal denervation and carotid baroreceptor stimulation) will be outlined.