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

Greater negative affective responsivity to daily stressors is positively related to urinary norepinephrine excretion in middle-aged adults

Despite mounting evidence that greater affective responsivity to naturally occurring daily stressors is associated with increased risk of cardiovascular diseases (CVDs), few studies have examined dysregulation of the sympathetic nervous system as a potential mechanism. We hypothesized that greater affective responsivity to daily stressful events would be related to increased urinary catecholamine excretion. Daily stress processes (8-day daily diary) were assessed in 715 middle-aged adults (56 ± 11 yr; 57% female) from the Midlife in the United States Study. Urinary norepinephrine and epinephrine concentrations were also measured (24 h; normalized to creatinine). Multilevel modeling was used to calculate negative and positive affective responsivity (i.e., the slope of the within-person differences in negative and positive affect on stressor days compared with stressor-free days). Analyses controlled for relevant covariates (e.g., sex, age, affect on stressor-free days, etc.). On stressor days, negative affect increased (0.1 ± 0.2 stressor-free days vs. 0.3 ± 0.4 au stressor days; P < 0.0001) and positive affect decreased (2.8 ± 0.7 stressor-free days vs. 2.6 ± 0.8 au stressor days; P < 0.0001). Greater negative affectivity responsivity to daily stressors was related to increased urinary norepinephrine (B = 0.42, SE = 0.14, P = 0.003), but not epinephrine (P = 0.142), excretion. Positive affective responsivity to daily stressors was not related to either urinary norepinephrine (B = -0.33, SE = 0.29, P = 0.24) or epinephrine (P = 0.626) excretion. Heightened negative affective responsivity to daily stressors was associated with greater urinary norepinephrine excretion, suggesting that sympathetic overactivation may contribute to the link between emotional vulnerability to daily stressors and increased CVD risk.NEW & NOTEWORTHY Few studies have examined sympathetic dysregulation as a potential mechanism linking affective responsivity to daily stressors to future cardiovascular diseases. Using a large national sample, our findings show that amplified negative affective responsivity to daily stressors is related to increased urinary norepinephrine excretion independent of the frequency of stressor occurrence. These data suggest that chronic sympathetic overactivation may contribute to the link between emotional vulnerability to daily stressors and increased risk of future cardiovascular comorbidities.

Decreased CO2 saturation during circular breathwork supports emergence of altered states of consciousness

Altered states of consciousness (ASCs), induced e.g. during psychedelic-assisted therapy, show potential to treat prevalent mental health disorders like depression and posttraumatic stress disorder. However, access to such treatments is restricted by legal, medical, and financial barriers. Circular breathwork may present a non-pharmacological and hence more accessible alternative to engage similar therapeutic processes. Scientific studies of breathwork are only just emerging and its physiological and psychological mechanisms are largely unknown. Here, we track physiological and experiential dynamics throughout a breathwork session, comparing two forms of breathwork: Holotropic and Conscious-Connected breathwork. We show that a reduction in end-tidal CO2 pressure due to deliberate hyperventilation is significantly correlated to ASC onset (r = -0.46; p < 0.001). Based on standard questionnaires (MEQ-30 and 11-DASC), the ASCs evoked by breathwork resembled those produced by psychedelics across several experiential domains such as ego dissolution, and their depth predicted psychological and physiological follow-on effects, including improved well-being and reduced depressive symptoms. Further analysis showed that different breathwork approaches produced highly similar outcomes. Our findings identify physiological boundary conditions for ASCs to arise in a non-pharmacological context, shedding light on the functional mechanisms of breathwork as well as its potential as a psychotherapeutic tool.

The Breathing IQ: an anthropometric index of diaphragmatic breathing efficiency

Background

Breathing pattern disorders (BPDs) are becoming increasingly relevant due to the rise of respiratory illnesses but are often limited to diagnoses of hyperventilation syndrome and do not consider breathing dysfunction of mechanical origin. Impaired diaphragmatic and inefficient breathing patterns often evolve into downstream musculoskeletal and psychological consequences. Respiratory research has consistently called for the standardization of methods that can consider breathing as multifactorial and also consider breathing mechanics.

Aim

This paper aims to introduce the Breathing IQ (BIQ) as a novel anthropometric index of abdominothoracic flexibility for identifying biomechanical breathing patterns and assessing diaphragmatic breathing efficiency.

Method

A sample of N = 384 individuals was assessed with the BIQ pre- and post-intervention of five corrective exercises in a single 90-minute session to identify changes in the BIQ grade (A-F), as determined by measuring the breathing range of motion (ROM) and location of movement (LOM).

Results

Binary-grade improvement (yes/no) occurred in 331 of 370 without an A grade at baseline (89.5%), p < 0.001. Before the intervention, 249 (64.8%) were graded an F and only 14 (3.7%) were graded an A. After the intervention, only 20 (5.2%) were graded an F and 102 (26.6%) were graded an A. Breath hold (BH) improved from pre- to post-intervention, from 37.2 (18.7) to 66.0 (26.9), with a mean change 24.3 (15.3), which was highly significant (p < 0.001).

Conclusion

The BIQ shows preliminary potential as an effective screening tool for mechanical breathing dysfunction.

Autonomic modulation with mindfulness-based stress reduction in chronic kidney disease: a randomized controlled trial

Chronic kidney disease (CKD) is characterized by overactivation of the sympathetic nervous system (SNS) that leads to increased risk of cardiovascular disease. This study was conducted to evaluate the effects of a Mindfulness-Based Stress Reduction (MBSR) programme on SNS activity in CKD patients. Participants with CKD stages III-IV were randomized to the 8 week MBSR programme or Health Enhancement Program (HEP; a structurally parallel, active control group). Intraneural measures of SNS activity directed to muscle [muscle sympathetic nerve activity (MSNA)] via microneurography was recorded at rest and during stress manoeuvres (mental arithmetic, handgrip exercise and cold pressor test). Data analyses were performed based on the intent-to-treat principle. In total, 29 participants (64 ± 9 years; 86% males) completed the intervention with 17 in the MBSR and 12 in the HEP groups. There was a significant Group (MBSR vs. HEP) by Time (baseline vs. post-intervention) interaction in MSNA reactivity to mental stress (P = 0.029), with a significant reduction in the mean ∆MSNA over 3 min of mental arithmetic at post-intervention (10.3 ± 4.2-5.9 ± 5.6 bursts/min, P < 0.001; Hedges' g = -0.858, 95% confidence interval [-1.578, -0.167]), while no change was observed within the HEP group (P = 0.818). Reduced ∆MSNA during handgrip exercise was also observed, while ∆MSNA during the cold pressor test and resting MSNA remained unchanged in both groups from baseline to post-intervention. In this randomized controlled trial, patients with CKD had a reduction of sympathetic reactivity during mental stress and static handgrip exercise following 8 weeks of MBSR but not after HEP. Our findings demonstrate that mindfulness training is feasible and may have clinically beneficial effects on autonomic function in CKD. KEY POINTS: Question: Does the Mindfulness-Based Stress Reduction (MBSR) programme reduce sympathetic activity in patients with chronic kidney disease (CKD)? Finding: In this randomized controlled trial including 29 patients with CKD, 8 weeks of MBSR decreased sympathetic reactivity to mental stress compared to the control Health Enhancement Program (HEP). Meaning: These finding suggest that mindfulness training may have clinically beneficial effects on autonomic function in CKD.

Impact of COVID-19 on Diaphragmatic Function: Understanding Multiorgan Involvement and Long-Term Consequences

The COVID-19 pandemic has brought significant attention to the respiratory system, with much focus on lung-related disorders. However, the diaphragm, a crucial component of respiratory physiology, has not been adequately studied, especially in the context of long COVID. This review explores the multipotential role of the diaphragm in both respiratory health and disease, emphasizing its involvement in long-term complications following SARS-CoV-2 infection. The diaphragm's fundamental role in respiratory physiology and its impact on balance and posture control, breathing patterns, and autonomic nervous system regulation are discussed. This review examines complications arising from COVID-19, highlighting the diaphragm's involvement in neurological, musculoskeletal, and inflammatory responses. Particular attention is given to the neuroinvasive impact of SARS-CoV-2, the inflammatory response, and the direct viral effects on the diaphragm. The diaphragm's role in long COVID is explored, with a focus on specific symptoms such as voice disorders, pelvic floor dysfunction, and sleep disturbances. Diagnostic challenges, current methods for assessing diaphragmatic dysfunction, and the complexities of differentiating it from other conditions are also explored. This article is the first to comprehensively address diaphragmatic dysfunction resulting from COVID-19 and long COVID across various physiological and pathological aspects, offering a new perspective on its diagnosis and treatment within a multisystem context.

Autonomic Modulation with Mindfulness-Based Stress Reduction in Chronic Kidney Disease: A Randomized Controlled Trial

Background

Chronic kidney disease (CKD) is characterized by overactivation of the sympathetic nervous system (SNS) that leads to increased cardiovascular disease risk. Despite the deleterious consequences of SNS overactivity, there are very few therapeutic options available to combat sympathetic overactivity.

Aim

To evaluate the effects of Mindfulness-Based Stress Reduction (MBSR) on SNS activity in CKD patients.

Method

Participants with CKD stages III-IV were randomized to an 8-week MBSR program or Health Education Program (HEP; a structurally parallel, active control group). Primary outcomes were direct intraneural measures of SNS activity directed to muscle (MSNA) via microneurography at rest and during stress maneuvers.

Results

28 participants (63 ±9 years; 86% males) completed the intervention with 16 in MBSR and 12 in HEP. There was a significant Group (MBSR vs. HEP) by Time (baseline vs. post-intervention) interaction in the change in MSNA reactivity to mental stress (p=0.026), with a significant reduction in the mean change in MSNA over 3 minutes of mental arithmetic at post-intervention (10.6 ± 7.1 to 5.0 ± 5.7 bursts/min, p<0.001), while no change was observed within the HEP group (p=0.773).

Conclusions

In this randomized controlled trial, patients with CKD had an amelioration of sympathetic reactivity during mental stress following 8-weeks of MBSR but not after HEP. Our findings demonstrate that mindfulness training is feasible and may have clinically beneficial effects on autonomic function in CKD.

Acute nasal breathing lowers diastolic blood pressure and increases parasympathetic contributions to heart rate variability in young adults

There is growing interest in how breathing pace, pattern, and training (e.g., device-guided or -resisted breathing) affect cardiovascular health. It is unknown whether the route of breathing (nasal vs. oral) affects prognostic cardiovascular variables. Because nasal breathing can improve other physiological variables (e.g., airway dilation), we hypothesized that nasal compared with oral breathing would acutely lower blood pressure (BP) and improve heart rate variability (HRV) metrics. We tested 20 adults in this study [13 females/7 males; age: 18(1) years, median (IQR); body mass index: 23 ± 2 kg·m-2, means ± SD]. We compared variables between nasal- and oral-only breathing (random order, five min each) using paired, two-tailed t tests or Wilcoxon signed-rank paired tests with significance set to P < 0.05. We report the median (interquartile range) for diastolic BP and means ± SD for all other variables. We found that nasal breathing was associated with a lower mean BP (nasal: 84 ± 7 vs. oral: 86 ± 5 mmHg, P = 0.006, Cohen's d = 0.70) and diastolic BP [nasal: 68(8) vs. oral: 72(5) mmHg, P < 0.001, Rank-biserial correlation = 0.89] but not systolic BP (nasal: 116 ± 11 vs. oral: 117 ± 9 mmHg, P = 0.48, Cohen's d = 0.16) or heart rate (HR; nasal: 74 ± 10 vs. oral: 75 ± 8 beats·min-1, P = 0.90, Cohen's d = 0.03). We also found that nasal breathing was associated with a higher high-frequency (HF) contribution to HRV (nasal: 59 ± 19 vs. oral: 52 ± 21%, P = 0.04, Cohen's d = 0.50) and a lower low frequency-to-HF ratio at rest (nasal: 0.9 ± 0.8 vs. oral: 1.2 ± 0.9, P = 0.04, Cohen's d = 0.49). These data suggest that nasal compared with oral breathing acutely 1) lowers mean and diastolic BP, 2) does not affect systolic BP or heart rate, and 3) increases parasympathetic contributions to HRV.NEW & NOTEWORTHY There is growing interest in how breathing pace, pattern, and training (e.g., device-guided or -resisted breathing) affect prognostic cardiovascular variables. However, the potential effects of the breathing route on prognostic cardiovascular variables are unclear. These data suggest that nasal compared with oral breathing 1) lowers mean and diastolic blood pressure (BP), 2) does not affect systolic BP or heart rate (HR), and 3) increases parasympathetic contributions to heart rate variability (HRV). These data suggest that acute nasal breathing improves several prognostic cardiovascular variables.

The integration of yoga breathing techniques in cognitive behavioral therapy for post-traumatic stress disorder: A pragmatic randomized controlled trial

Introduction

In trauma-focused Cognitive Behavioral Therapy (TF-CBT), stabilization techniques are used before confrontation ones to increase stress/affect tolerance and thus effectiveness of CBT. This study investigated the effects of pranayama, meditative yoga breathing and breath holding techniques, as a complimentary stabilization technique in patients with post-traumatic stress disorder (PTSD).

Methods

Seventy-four PTSD-patients (84% female, 44.2 ± 13 years) were randomized to receive either pranayama at the beginning of each TF-CBT session or TF-CBT alone. The primary outcome was self-reported PTSD severity after 10 sessions of TF-CBT. Secondary outcomes included quality of life, social participation, anxiety, depression, distress tolerance, emotion regulation, body awareness, breath-holding duration, acute emotional reaction to stress, and adverse events (AEs). Intention-to-treat (ITT) and exploratory per-protocol (PP) analyses of covariance with 95% confidence intervals (CI) were performed.

Results

ITT analyses revealed no significant differences on primary or secondary outcomes, except for breath-holding duration in favor of pranayama-assisted TF-CBT (20.81 s, 95%CI = 13.05|28.60). PP analyses of 31 patients without AEs during pranayama revealed significantly lower PTSD severity (-5.41, 95%CI = -10.17|-0.64) and higher mental quality of life (4.89, 95%CI = 1.38|8.41) than controls. In contrast, patients with AEs during pranayama breath holding reported significantly higher PTSD severity (12.39, 95%CI = 5.08|19.71) than controls. Concurrent somatoform disorders were found to be a significant moderator of change in PTSD severity (p = 0.029).

Conclusion

In PTSD patients without concurrent somatoform disorders, the integration of pranayama into TF-CBT might reduce post-traumatic symptoms and increase mental quality of life more efficiently than TF-CBT alone. The results remain preliminary until they can be replicated by ITT analyses.

Clinical trial registration

ClinicalTrials.gov, identifier NCT03748121.

Device-guided slow breathing alters postprandial oxidative stress in young adult males: A randomized sham-controlled crossover trial

BACKGROUND AND AIMS

Slow, deep breathing (SDB) lowers blood pressure (BP) though the underlying mechanisms are unknown. Redox improvements could facilitate hemodynamic adjustments with SDB though this has not been investigated. The purpose of this randomized, sham-controlled trial was to examine the acute effects of SDB on oxidative stress and endothelial function during a physiological perturbation (high-fat meal) known to induce oxidative stress.

METHODS AND RESULTS

Seventeen males (ages 18-35 years) were enrolled, and anthropometric measurements and 7-day physical activity monitoring were completed. Testing sessions consisted of 24-h diet recalls (ASA24), blood sample collection for superoxide dismutase (SOD) and thiobarbituric acid reactive substances (TBARS) analysis, and flow-mediated dilation (FMD). High-fat meals were ingested and 2-min breathing exercises (SDB or sham control breathing) were completed every 15 min during the 4-h postprandial phase. Blood sample collection and FMD were repeated 1-, 2-, and 4-h post meal consumption. Mean body mass index and step counts were 25.6 ± 4.3 kg/m2 and 8165 ± 4405 steps per day, respectively. Systolic and diastolic BP and nutrient intake 24 h prior were similar between conditions. No time or time by condition interaction effects were observed for FMD. The total area under the curve (AUC) for SOD was significantly lower during SDB compared to the sham breathing condition (p < 0.01). No differences were observed in TBARS AUC (p = 0.538).

CONCLUSIONS

Findings from the current investigation suggest that SDB alters postprandial redox in the absence of changes in endothelial function in young, healthy males.

CLINICAL TRIAL REGISTRATION NUMBER

NCT04864184.

CLINICAL TRIALS IDENTIFIER

NCT04864184.

The effects of slow deep breathing on microvascular and autonomic function and symptoms in adults with irritable bowel syndrome: A pilot study

BACKGROUND

Irritable bowel syndrome (IBS) is linked to disruptions in sympathovagal balance, which could impair vascular homeostasis and cause IBS symptoms. Studies have shown reductions in sympathetic activity following a single slow, deep breathing (SDB) bout in healthy adults; however, no studies have investigated its chronic effects in IBS. The purpose of this study was to evaluate the feasibility and impact of a SDB intervention on microvascular and autonomic function and symptoms in adults with IBS.

METHODS

Fourteen participants (ages 18-65 years) with IBS were randomly assigned to 4-week SDB or control conditions. The SDB group completed a 20-min video 5 times weekly while the control group maintained their normal activities. Microvascular endothelial function was measured using laser Doppler in response to thermal provocation and expressed as cutaneous vascular conductance at 39°C relative to a maximum response at 43.5°C (%CVC_max ). Heart rate variability (HRV) and post-exercise heart rate recovery (HRR) were employed as surrogate measures of autonomic function. IBS symptoms were assessed using the IBS-Severity Scale (IBS-SS).

KEY RESULTS

Thirteen participants (6 controls and 7 SDB) completed the study. Age (p = 0.541) and body mass index (p = 0.157) were similar between groups. In the SDB group, %CVC_max increased from 45% to 59% (p < 0.00001) after the 4-week intervention. HRV, HRR, and IBS-SS scores were unaltered.

CONCLUSIONS

and Inferences. These results demonstrate the feasibility of a SDB intervention in adults with IBS and suggest improvements in microvascular function in the absence of changes in symptoms or autonomic function in this population.

Sympathetic Neural Control in Humans with Anxiety-Related Disorders

Numerous conceptual models are used to describe the dynamic responsiveness of physiological systems to environmental pressures, originating with Claude Bernard's milieu intérieur and extending to more recent models such as allostasis. The impact of stress and anxiety upon these regulatory processes has both basic science and clinical relevance, extending from the pioneering work of Hans Selye who advanced the concept that stress can significantly impact physiological health and function. Of particular interest within the current article, anxiety is independently associated with cardiovascular risk, yet mechanisms underlying these associations remain equivocal. This link between anxiety and cardiovascular risk is relevant given the high prevalence of anxiety in the general population, as well as its early age of onset. Chronically anxious populations, such as those with anxiety disorders (i.e., generalized anxiety disorder, panic disorder, specific phobias, etc.) offer a human model that interrogates the deleterious effects that chronic stress and allostatic load can have on the nervous system and cardiovascular function. Further, while many of these disorders do not appear to exhibit baseline alterations in sympathetic neural activity, reactivity to mental stress offers insights into applicable, real-world scenarios in which heightened sympathetic reactivity may predispose those individuals to elevated cardiovascular risk. This article also assesses behavioral and lifestyle modifications that have been shown to concurrently improve anxiety symptoms, as well as sympathetic control. Lastly, future directions of research will be discussed, with a focus on better integration of psychological factors within physiological studies examining anxiety and neural cardiovascular health. © 2022 American Physiological Society. Compr Physiol 12:1-33, 2022.

Autonomic dysfunction and cardiovascular risk in post-traumatic stress disorder

BACKGROUND

Patients with post-traumatic stress disorder (PTSD) have an increased risk for cardiovascular disease. The underlying mechanisms are unclear but impaired autonomic function may contribute. However, research in this field has shown contradictory results and the causal links between PTSD, autonomic dysfunction, and cardiovascular risk remain unknown. This brief review summarizes the current knowledge on alterations in autonomic function and cardiovascular risk in patients with PTSD.

LITERATURE SEARCH STRATEGY

A PubMed search of the literature was performed using the following keywords: autonomic function, heart rate variability, blood pressure variability, sympathetic activity, baroreflex function, and cardiovascular risk in combination with PTSD. Evidence-based studies conducted between 2000 and 2021 were selected.

RESULTS

In total 1221 articles were identified and of these, 61 (48 original research papers, 13 review articles) were included in this review. Many, though not all, studies have reported increased activity of the sympathetic nervous system and decreased activity of the parasympathetic nervous system (namely, autonomic imbalance) in PTSD patients. There seems to be enough evidence to suggest impairments in baroreflex function in PTSD, leading to blood pressure dysregulation. It appears that the chronicity of PTSD diagnosis and symptom severity are independent risk factors for cardiovascular disease, which may be linked with impaired autonomic function.

CONCLUSIONS

Increased cardiovascular risk may be associated with autonomic dysfunction in PTSD. Whether autonomic dysfunction can serve as a biomarker for the onset and progression of PTSD remains to be determined. It also needs to determine if autonomic imbalance increases the risk of developing PTSD.

Tackling hyperarousal: an integrative multimodal approach

Introduction: The effectiveness of treatment for PTSD is limited, which is especially true for war veterans, of whom 30-50% do not respond to therapy. Hyperarousal is central to the maintenance of trauma pathology. The mainstream trauma-focused therapies traditionally target the cognitive processing of traumatic experience. In this article, we propose that these therapies may be enhanced by the inclusion of interventions specifically targeting hyperarousal.Method: We review an earlier formulated model of trauma supporting our proposal. This model is based on a theory of trauma that integrates the concept of allostasis with the predictive processing framework. In this view, trauma is considered a maladaptive stress response guided by false inference.Results: The reviewed model is in agreement with the central role of hyperarousal in the maintenance of trauma-induced disorders. It also demonstrates the importance of targeting hyperarousal at the same time as maladaptive cognitions and behaviours associated with trauma. A treatment for PTSD is proposed that combines exposure to trauma-related cues with neurofeedback-mediated regulation of arousal.Conclusions: Our analysis argues for the integration of hyperarousal-targeting interventions into existing therapies. Accordingly, we offer methodological considerations based on the nested hierarchy principle that can guide such integration.

Interventions and Manipulations of Interoception

Interoceptive pathways may be manipulated at various levels to develop interventions to improve symptoms in a range of disorders. Primarily through the lens of the respiratory system, we outline various pathways that can be manipulated at neural, behavioral, and psychological levels to change the representation of and attention to interoceptive signals, which can alter interconnected physiological systems and improve functioning and adaptive behavior. Interventions can alter interoception via neuromodulation of the vagus nerve, slow breathing to change respiratory rate and depth, or awareness processes such as mindfulness-based interventions. Aspects of this framework may be applied to other physiological systems and future research may integrate interventions across multiple levels of manipulation or bodily systems.