Device-guided breathing as treatment for hypertension in type 2 diabetes mellitus: a randomized, double-blind, sham-controlled trial

Integrated use of biofeedback and neurofeedback techniques in treating pathological conditions and improving performance: a narrative review

In recent years, the scientific community has begun tо explore the efficacy оf an integrated neurofeedback + biofeedback approach іn various conditions, both pathological and non-pathological. Although several studies have contributed valuable insights into its potential benefits, this review aims tо further investigate its effectiveness by synthesizing current findings and identifying areas for future research. Our goal іs tо provide a comprehensive overview that may highlight gaps іn the existing literature and propose directions for subsequent studies. The search for articles was conducted on the digital databases PubMed, Scopus, and Web of Science. Studies to have used the integrated neurofeedback + biofeedback approach published between 2014 and 2023 and reviews to have analyzed the efficacy of neurofeedback and biofeedback, separately, related to the same time interval and topics were selected. The search identified five studies compatible with the objectives of the review, related to several conditions: nicotine addiction, sports performance, Autism Spectrum Disorder (ASD), and Attention Deficit Hyperactivity Disorder (ADHD). The integrated neurofeedback + biofeedback approach has been shown to be effective in improving several aspects of these conditions, such as a reduction in the presence of psychiatric symptoms, anxiety, depression, and withdrawal symptoms and an increase in self-esteem in smokers; improvements in communication, imitation, social/cognitive awareness, and social behavior in ASD subjects; improvements in attention, alertness, and reaction time in sports champions; and improvements in attention and inhibitory control in ADHD subjects. Further research, characterized by greater methodological rigor, is therefore needed to determine the effectiveness of this method and the superiority, if any, of this type of training over the single administration of either. This review іs intended tо serve as a catalyst for future research, signaling promising directions for the advancement оf biofeedback and neurofeedback methodologies.

Mapping interventional components and behavior change techniques used to promote self-management in people with multimorbidity: a scoping review

Ageing populations and improved survival, have contributed to a rise in the number of people living with multimorbidity, raising issues related to polypharmacy, treatment burden, competing priorities and poor coordination of care. Self-management programs are increasingly included as an essential component of interventions to improve outcomes in this population. However, an overview of how interventions supporting self-management in patients with multimorbidity is missing. This scoping review focused on mapping the literature on patient-centered interventions for people living with multimorbidity. We searched several databases, clinical registries, and grey literature for RCTs published between 1990-2019 describing interventions that supported self-management in people with multimorbidity. We included 72 studies that were found to be very heterogeneous when it comes to the population, delivery modes and modalities, intervention elements and facilitators. The results pointed to an extensive use of cognitive behavioral therapy as a basis for interventions, as well as behavior change theories and disease management frameworks. The most coded behavior change techniques stemmed from the categories Social Support, Feedback and monitoring and Goals and Planning. To allow for implementation of effective interventions in clinical practice, improved reporting of intervention mechanisms in RCTs is warranted.

Device and nondevice‐guided slow breathing to reduce blood pressure in hypertensive patients: A systematic review and meta‐analysis

Backgroud and Aims

Hypertension (HTN) is a multifactorial chronic disease. Considering the high prevalence rates of this disease, treatment of HTN is necessary, not only to reduce blood pressure (BP) levels but also to prevent the development of cardiovascular, cerebrovascular, and kidney diseases. This treatment can be through medication, which will be determined according to the BP values, obtained either in medical consultations or at home; presence of cardiovascular risk factors, and the presence of target organ damage identified during anamnesis. The aim of this systematic review and meta‐analysis is to summarize the effects of device‐guided slow breathing (DGSB) and nondevice‐guided slow breathing (NDGSB) on BP levels of patients with HTN.

Methods

This study is a systematic review and meta‐analysis of randomized clinical trials, pertaining to hypertensive patients, with or without comorbidity, over 18 years old, of both sexes, and with or without hypertensive medication. The selected studies showed comparisons between groups that performed DGSB and/or NDGSB with control conditions. The primary outcome was the value of systolic blood pressure (SBP) and diastolic blood pressure (DBP) after the interventions.

Results

Twenty‐two studies involving 17,214 participants were included in the quantitative analysis. Considerable heterogeneity was revealed between studies. Using random effect model, it was found that DGSB did not significantly reduce SBP and DBP compared to usual care, both in terms BP values and in relation to their variations (SBP, mean difference [MD]: −2.13 mmHg, (95% confidence interval [CI]: −12.71 to 8.44), 288 individuals; I² = 93%, high heterogenity: DBP, MD: −0.90, 95% CI: −3.97 to 2.11, 288 individuals; I² = 63%, substantial heterogenity. SBP variations MD: −2.42, 95% CI: −7.24 to 2.40, 443 individuals; I² = 85% high heterogenity/DBP variations MD: −1.67, 95% CI: −4.57 to 1.24, 443 individuals; I² = 80%, high heterogenity).

Conclusion

Based on these results it appears that DGSB did not reduce BP in hypertensive patients and NDGSB is a new path for the future.

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.

Eight weeks of device-guided slow breathing decreases sympathetic nervous reactivity to stress in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is characterized by increased risk for developing hypertension and cardiovascular disease. We recently showed that device-guided slow breathing (DGB) acutely lowers blood pressure (BP) and muscle sympathetic activity (MSNA) and improves baroreflex sensitivity (BRS) in PTSD. The aim of this study was to assess the long-term benefits of DGB on autonomic function at rest and during stress. We hypothesized that long-term DGB improves arterial BRS and lowers BP and MSNA in PTSD. Twenty-five veterans with PTSD were studied and randomized to either 8 wk of daily DGB (n = 12) or 8 wk of sham device (Sham; n = 13). BP, heart rate (HR), and MSNA were measured at rest and during mental math. Arterial BRS was assessed using the modified Oxford technique. Resting MSNA, BP, and heart rate (HR) remained comparable before and after 8 wk in both groups (DGB and Sham). Likewise, the change in sympathetic and cardiovagal BRS was not different between the groups. Interestingly, DGB significantly decreased MSNA reactivity to mental math when expressed as burst frequency (P = 0.012) or burst incidence (P = 0.008) compared with Sham, suggesting a sustained effect of DGB on sympathetic reactivity to stress in PTSD. Contrary to our hypothesis, long-term DGB did not lower systolic BP, diastolic BP, or HR responses to stress compared with Sham. Likewise, pulse pressure reactivity after 8 wk (P = 0.121) was also comparable. In summary, these data suggest that long-term use of DGB may lead to a sustained dampening of sympathetic reactivity to mental stress in PTSD.

Acute effects of device-guided slow breathing on sympathetic nerve activity and baroreflex sensitivity in posttraumatic stress disorder

Patients with posttraumatic stress disorder (PTSD) have elevated sympathetic nervous system reactivity and impaired sympathetic and cardiovagal baroreflex sensitivity (BRS). Device-guided slow breathing (DGB) has been shown to lower blood pressure (BP) and sympathetic activity in other patient populations. We hypothesized that DGB acutely lowers BP, heart rate (HR), and improves BRS in PTSD. In 23 prehypertensive veterans with PTSD, we measured continuous BP, ECG, and muscle sympathetic nerve activity (MSNA) at rest and during 15 min of DGB at 5 breaths/min ( n = 13) or identical sham device breathing at normal rates of 14 breaths/min (sham; n = 10). Sympathetic and cardiovagal BRS was quantified using pharmacological manipulation of BP via the modified Oxford technique at baseline and during the last 5 min of DGB or sham. There was a significant reduction in systolic BP (by -9 ± 2 mmHg, P < 0.001), diastolic BP (by -3 ± 1 mmHg, P = 0.019), mean arterial pressure (by -4 ± 1 mmHg, P = 0.002), and MSNA burst frequency (by -7.8 ± 2.1 bursts/min, P = 0.004) with DGB but no significant change in HR ( P > 0.05). Within the sham group, there was no significant change in diastolic BP, mean arterial pressure, HR, or MSNA burst frequency, but there was a small but significant decrease in systolic BP ( P = 0.034) and MSNA burst incidence ( P = 0.033). Sympathetic BRS increased significantly in the DGB group (-1.08 ± 0.25 to -2.29 ± 0.24 bursts·100 heart beats^-1·mmHg^-1, P = 0.014) but decreased in the sham group (-1.58 ± 0.34 to -0.82 ± 0.28 bursts·100 heart beats^-1·mmHg^-1, P = 0.025) (time × device, P = 0.001). There was no significant difference in the change in cardiovagal BRS between the groups (time × device, P = 0.496). DGB acutely lowers BP and MSNA and improves sympathetic but not cardiovagal BRS in prehypertensive veterans with PTSD. NEW & NOTEWORTHY Posttraumatic stress disorder is characterized by augmented sympathetic reactivity, impaired baroreflex sensitivity, and an increased risk for developing hypertension and cardiovascular disease. This is the first study to examine the potential beneficial effects of device-guided slow breathing on hemodynamics, sympathetic activity, and arterial baroreflex sensitivity in prehypertensive veterans with posttraumatic stress disorder.

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.

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.

Inspiratory Muscle Training Improves Sleep and Mitigates Cardiovascular Dysfunction in Obstructive Sleep Apnea

STUDY OBJECTIVES

New and effective strategies are needed to manage the autonomic and cardiovascular sequelae of obstructive sleep apnea (OSA). We assessed the effect of daily inspiratory muscle strength training (IMT) on sleep and cardiovascular function in adults unable to use continuous positive airway pressure (CPAP) therapy.

METHODS

This is a placebo-controlled, single-blind study conducted in twenty four adults with mild, moderate, and severe OSA. Subjects were randomly assigned to placebo or inspiratory muscle strength training. Subjects in each group performed 5 min of training each day for 6 w. All subjects underwent overnight polysomnography at intake and again at study close.

RESULTS

We evaluated the effects of placebo training or IMT on sleep, blood pressure, and plasma catecholamines. Relative to placebo-trained subjects with OSA, subjects with OSA who performed IMT manifested reductions in systolic and diastolic blood pressures (-12.3 ± 1.6 SBP and -5.0 ± 1.3 DBP mmHg; P < 0.01); plasma norepinephrine levels (536.3 ± 56.6 versus 380.6 ± 41.2 pg/mL; P = 0.01); and registered fewer nighttime arousals and reported improved sleep (Pittsburgh Sleep Quality Index scores: 9.1 ± 0.9 versus 5.1 ± 0.7; P = 0.001). These favorable outcomes were achieved without affecting apneahypopnea index.

CONCLUSIONS

The results are consistent with our previously published findings in normotensive adults but further indicate that IMT can modulate blood pressure and plasma catecholamines in subjects with ongoing nighttime apnea and hypoxemia. Accordingly, we suggest IMT offers a low cost, nonpharmacologic means of improving sleep and blood pressure in patients who are intolerant of CPAP.

Hemodynamic effects of slow breathing: does the pattern matter beyond the rate?

PURPOSE

Patterned breathing allows standardized serial measurements of heart rate variability and baroreflex indices. The slow breathing augments these parameters, and regular exercises, including yoga breathing practices with even respiratory rates have long-term beneficial effects in cardiovascular diseases. The role of temporization of breathing phases, i.e. the ratio of expiration to inspiration, is not known. In order to characterize the hemodynamic and autonomic responses during varying breathing phases 27 volunteers performed three short breathing sessions at 6/minutes frequency with 5:5, 3:7 and 7:3 inspiration expiration ratios.

RESULTS

The immediate responses in arterial pressure and heart rate were negligible. The time domain parameters of heart rate variability (SDRR, PNN50,RMSSD) increased significantly with patterned breathing. So did the spontaneous baroreflex gain of increasing sequences (up-BRS, from 12 ± 7 to 17 ± 10 ms/mmHg, p < 0.05), and the cross-spectral low frequency gain, the LFalpha (from 11 ± 7 to 15 ± 7 ms/mmHg, p < 0.05). None of these parameters differed significantly from each other while using any of tested inspiratory-expiratory patterns.

CONCLUSION

The major determinant of autonomic responses induced by slow patterned breathing is the breathing rate itself. From our observations, it follows that slow breathing exercises performed either with diagnostic or therapeutic purpose could be simplified, allowing more extensive investigations.

Increased cardio-respiratory coupling evoked by slow deep breathing can persist in normal humans

Slow deep breathing (SDB) has a therapeutic effect on autonomic tone. Our previous studies suggested that coupling of the cardiovascular to the respiratory system mediates plasticity expressed in sympathetic nerve activity. We hypothesized that SDB evokes short-term plasticity of cardiorespiratory coupling (CRC). We analyzed respiratory frequency (fR), heart rate and its variability (HR&HRV), the power spectral density (PSD) of blood pressure (BP) and the ventilatory pattern before, during, and after a 20-min epoch of SDB. During SDB, CRC and the relative PSD of BP at fR increased; mean arterial pressure decreased; but HR varied; increasing (n = 3), or decreasing (n = 2) or remaining the same (n = 5). After SDB, short-term plasticity was not apparent for the group but for individuals differences existed between baseline and recovery periods. We conclude that a repeated practice, like pranayama, may strengthen CRC and evoke short-term plasticity effectively in a subset of individuals.

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.