Autonomic nervous system activity and workplace stressors--a systematic review

The role of perseverative cognition in the job strain-health outcome relationship

Objective.

Job strain has been implicated in a variety of adverse health outcomes, particularly cardiometabolic and inflammatory diseases. However, the mechanisms underlying these effects remain largely unknown. One possibility is that the maladaptive coping response to stress, (perseverative cognition (PC); the cognitive representation of past stressful events (rumination) or feared future events (worry)), either in work or more generally, mediates the relationship between job strain and physical disease. The aim of this study was thus to test the potential role of both general, and work- related PC as a mediating, or potentially moderating, mechanism between job strain and ill- health outcomes.

Design & Measures.

Using an online cross- sectional design, 650 full- time employees completed measures of job strain, general and work- related PC (rumination & worry) and health outcomes (burnout, somatization, health behaviours & sleep quality).

Results.

General and work- related worry and rumination significantly mediated, often independently, the relationship between job strain and burnout, somatization, and sleep quality. No significant mediation effects were observed for health behaviours and no type of PC (general or work- related) moderated job strain- health outcome relations.

Conclusion.

Both general and work- related worry and rumination are likely to play important, and partly independent, roles in understanding the adverse relationships between job strain and various health outcomes.

Stress and cardiovascular disease: an update

Psychological stress is generally accepted to be associated with an increased risk of cardiovascular disease (CVD), but results have varied in terms of how stress is measured and the strength of the association. Additionally, the mechanisms and potential causal links have remained speculative despite decades of research. The physiological responses to stress are well characterized, but their contribution to the development and progression of CVD has received little attention in empirical studies. Evidence suggests that physiological responses to stress have a fundamental role in the risk of CVD and that haemodynamic, vascular and immune perturbations triggered by stress are especially implicated. Stress response physiology is regulated by the corticolimbic regions of the brain, which have outputs to the autonomic nervous system. Variation in these regulatory pathways might explain interindividual differences in vulnerability to stress. Dynamic perturbations in autonomic, immune and vascular functions are probably also implicated as CVD risk mechanisms of chronic, recurring and cumulative stressful exposures, but more data are needed from prospective studies and from assessments in real-life situations. Psychological assessment remains insufficiently recognized in clinical care and prevention. Although stress-reduction interventions might mitigate perceived stress levels and potentially reduce cardiovascular risk, more data from randomized trials are needed.

A bibliometric analysis of coronary heart disease impacted by work stress elements and lifestyle disease

PURPOSE

One psychosocial risk factor that has drawn attention is work-related stress, although it is still unclear how exactly this risk factor relates to poor health. Prospective observational studies have found a 40%-50% raise in the incidence of coronary heart disease in those who experience chronic stress at work and in their personal lives.

THEORETICAL FRAMEWORK

In the recent decade, there has been a rise in the requirement for firms to gather information on job stress on employees that leads to coronary heart disease. As a result, this study on trends in Coronary Heart Disease induced by Work Stress becomes necessary to examine all of these efforts.

DESIGN/METHODOLOGY

This research employs bibliometric analysis and charting to describe the growth and structure of the research field of work-related stress causing coronary heart disease. The field's conceptual framework and research boundaries, the connections between publications and the contributors, key phrases, the latest networks of collaboration, the most prevalent concepts, and the most cited authors are all revealed by our findings.

FINDINGS

Research found that this field has seen a significant increase in research on coronary heart disease in recent years. Because it has been demonstrated that there is a rise in deaths from cardiovascular disease, researchers, academics, and professionals should be made aware of how stress can lead to coronary heart disease.

ORIGINALITY/VALUE

The study suggests that workplace health should be a priority for both developed and developing nations, and it must be disseminated in several languages.

Sleep-phasic heart rate variability predicts stress severity: Building a machine learning-based stress prediction model

We propose a novel approach for predicting stress severity by measuring sleep phasic heart rate variability (HRV) using a smart device. This device can potentially be applied for stress self-screening in large populations. Using a Holter electrocardiogram (ECG) and a Huawei smart device, we conducted 24-h dual recordings of 159 medical workers working regular shifts. Based on photoplethysmography (PPG) and accelerometer signals acquired by the Huawei smart device, we sorted episodes of cyclic alternating pattern (CAP; unstable sleep), non-cyclic alternating pattern (NCAP; stable sleep), wakefulness, and rapid eye movement (REM) sleep based on cardiopulmonary coupling (CPC) algorithms. We further calculated the HRV indices during NCAP, CAP and REM sleep episodes using both the Holter ECG and smart-device PPG signals. We later developed a machine learning model to predict stress severity based only on the smart device data obtained from the participants along with a clinical evaluation of emotion and stress conditions. Sleep phasic HRV indices predict individual stress severity with better performance in CAP or REM sleep than in NCAP. Using the smart device data only, the optimal machine learning-based stress prediction model exhibited accuracy of 80.3 %, sensitivity 87.2 %, and 63.9 % for specificity. Sleep phasic heart rate variability can be accurately evaluated using a smart device and subsequently can be used for stress predication.

Correlation analysis of occupational stress and metabolic syndrome among employees of a power grid enterprise in China

BACKGROUND

Being in a state of high occupational stress may disrupt the metabolic balance of the body, thus increasing the risk of metabolic diseases. However, the evidence about the relationship between occupational stress and metabolic syndrome was limited.

OBJECTIVES

To explore the association between occupational stress and metabolic syndrome (MetS) in employees of a power grid enterprise.

METHODS

A total of 1091 employees were recruited from a power grid enterprise in China. Excluding those who failed to complete the questionnaire and those who had incomplete health check-ups, 945 subjects were included in the study. Assessment of occupational stress was used by job demand-control (JDC) and effort-reward imbalance (ERI) questionnaires, respectively. The information on body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were collected. The levels of high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and fasting blood glucose (FBG) in the fasting venous blood samples were measured. Logistic regression analysis and multiple linear regression methods were used to analyze the correlation between JDC and ERI models of occupational stress, metabolic syndrome, and its components, respectively.

RESULTS

The prevalence of MetS was 8.4% and 9.9% in JDC and ERI model high occupational stress employees, respectively. ERI model occupational stress and smoking are significantly associated with the risk of MetS. ERI ratio was significantly associated with lower HDL-C levels. Gender, age, marital status, smoking, high-temperature and high-altitude work were significantly associated with metabolic component levels.

CONCLUSION

Our study revealed a high detection rate of occupational stress in both JDC and ERI models among employees of a power grid enterprise. ERI model occupational stress, demanding more attention, was associated with the risk of MetS as well as its components such as HDL-C.

Putting the usability of wearable technology in forensic psychiatry to the test: a randomized crossover trial

Introduction

Forensic psychiatric patients receive treatment to address their violent and aggressive behavior with the aim of facilitating their safe reintegration into society. On average, these treatments are effective, but the magnitude of effect sizes tends to be small, even when considering more recent advancements in digital mental health innovations. Recent research indicates that wearable technology has positive effects on the physical and mental health of the general population, and may thus also be of use in forensic psychiatry, both for patients and staff members. Several applications and use cases of wearable technology hold promise, particularly for patients with mild intellectual disability or borderline intellectual functioning, as these devices are thought to be user-friendly and provide continuous daily feedback.

Method

In the current randomized crossover trial, we addressed several limitations from previous research and compared the (continuous) usability and acceptance of four selected wearable devices. Each device was worn for one week by staff members and patients, amounting to a total of four weeks. Two of the devices were general purpose fitness trackers, while the other two devices used custom made applications designed for bio-cueing and for providing insights into physiological reactivity to daily stressors and events.

Results

Our findings indicated significant differences in usability, acceptance and continuous use between devices. The highest usability scores were obtained for the two fitness trackers (Fitbit and Garmin) compared to the two devices employing custom made applications (Sense-IT and E4 dashboard). The results showed similar outcomes for patients and staff members.

Discussion

None of the devices obtained usability scores that would justify recommendation for future use considering international standards; a finding that raises concerns about the adaptation and uptake of wearable technology in the context of forensic psychiatry. We suggest that improvements in gamification and motivational aspects of wearable technology might be helpful to tackle several challenges related to wearable technology.

Work stress and changes in heart rate variability among employees after first acute coronary syndrome: a hospital-based longitudinal cohort study

Background

Work stress is considered as a risk factor for coronary heart disease, but its link with heart rate variability (HRV) among heart attack survivors is unknown yet. The aim of this study was to investigate associations between baseline work stress and the changes of HRV over one-year after onset of acute coronary syndrome (ACS).

Methods

Hundred and twenty-two patients with regular paid work before their first ACS episode were recruited into this hospital-based longitudinal cohort study. During hospitalization (baseline), all patients underwent assessments of work stress by job strain (JS) and effort-reward imbalance (ERI) models, and were assigned into low or high groups; simultaneously, sociodemographic and clinical data, as well depression, anxiety, and job burnout, were collected. Patients were followed up 1, 6, and 12 months after discharge, with HRV measurements at baseline and each follow-up point. Generalized estimating equations were used to analyze the effects of baseline work stress on HRV over the following 1 year.

Results

After adjusting for baseline characteristics and clinical data, anxiety, depression, and burnout scores, high JS was not associated with any HRV measures during follow-up (all p > 0.10), whereas high ERI was significantly related to slower recovery of 5 frequency domain HRV measures (TP, HF, LF, VLF, and ULF) (all p < 0.001), and marginally associated with one time domain measure (SDNN) (p = 0.069). When mutually adjusting for both work stress models, results of ERI remained nearly unchanged.

Conclusion

Work stress in terms of ERI predicted lower HRV during the one-year period after ACS, especially frequency domain measures.

Improving Well-Being and Fostering Health-Oriented Leadership among Leaders in Small and Medium-Sized Enterprises (SMEs): A Systematic Review

Leaders of small and medium-sized enterprises (SMEs) are often confronted with specific burdens, which frequently result in increased levels of stress. Leadership behaviour, in turn, has a significant impact on employees' health and performance. Using the Population, Intervention, Comparison, Outcome (PICO) method, we conducted a systematic literature search covering publications from 2002 to 2023 using PubMed, PsycInfo and Business Source Premier on stress-reducing and well-being-improving interventions for SME leaders. The Effective Public Health Practice Project (EPHPP) Quality Assessment Tool was used to assess the methodological quality and risk of bias of the included studies regarding selection bias, study design, confounders, blinding, data collection, withdrawal and drop-out. Of the 3150 identified publications, 6 were included after screening. The studies varied in content (cognitive behavioural therapy [CBT]-based, psychoeducation, and mixed interventions) and approach (individual- and organisation-centred). Not all of the examined interventions provided significant outcomes. However, CBT-based and individualised approaches showed a positive trend in reducing SME leaders' psychosocial stress and improving their well-being. Despite the limited data, it can be concluded that such interventions are beneficial for leaders and their specific needs. Future research should focus on tailored approaches, derived from well-founded theories and integrative interventions addressing SME leaders.

Cardiac autonomic profile, perceived stress and environmental comfort in healthy employees during remote and in-office work

Remote work (REMOTE) causes an overlap between working and domestic demands. The study of the cardiac autonomic profile (CAP) by means of heart rate variability (HRV) provides information about the impact of REMOTE on workers' health. The primary aim was to determine whether CAP, self-perceived stress, environmental and workstation comfort are modified during REMOTE. The secondary aim was to explore how these indices are influenced by individual and environmental work-related factors. Fifty healthy office employees alternating REMOTE and in-office (OFFICE) working were enrolled, rated self-perceived stress, environmental and workstation comfort using a visual analogue scale and performed a 24-h electrocardiogram during REMOTE and OFFICE. Stress was lower (5.6 ± 2.2 vs. 6.4 ± 1.8), environmental comfort higher (7.7 ± 1.9 vs. 7.0 ± 1.5), and the workstation comfort poorer (6.2 ± 1.8 vs. 7.5 ± 1.2) during REMOTE. CAP was similar during REMOTE and OFFICE. CAP was influenced by some work-related factors, including the presence of offspring, absence of a dedicated workspace during REMOTE and number of working hours. All these variables determined a decreased vagal modulation. The working setting seems to impact the levels of perceived stress and comfort, but not the CAP. However, individual and environmental work-related factors reduce cardiac vagal modulation during REMOTE, potentially increasing the risk of developing cardiovascular diseases.

Health position paper and redox perspectives - Disease burden by transportation noise

Transportation noise is a ubiquitous urban exposure. In 2018, the World Health Organization concluded that chronic exposure to road traffic noise is a risk factor for ischemic heart disease. In contrast, they concluded that the quality of evidence for a link to other diseases was very low to moderate. Since then, several studies on the impact of noise on various diseases have been published. Also, studies investigating the mechanistic pathways underlying noise-induced health effects are emerging. We review the current evidence regarding effects of noise on health and the related disease-mechanisms. Several high-quality cohort studies consistently found road traffic noise to be associated with a higher risk of ischemic heart disease, heart failure, diabetes, and all-cause mortality. Furthermore, recent studies have indicated that road traffic and railway noise may increase the risk of diseases not commonly investigated in an environmental noise context, including breast cancer, dementia, and tinnitus. The harmful effects of noise are related to activation of a physiological stress response and nighttime sleep disturbance. Oxidative stress and inflammation downstream of stress hormone signaling and dysregulated circadian rhythms are identified as major disease-relevant pathomechanistic drivers. We discuss the role of reactive oxygen species and present results from antioxidant interventions. Lastly, we provide an overview of oxidative stress markers and adverse redox processes reported for noise-exposed animals and humans. This position paper summarizes all available epidemiological, clinical, and preclinical evidence of transportation noise as an important environmental risk factor for public health and discusses its implications on the population level.

Deep breathing in your hands: designing and assessing a DTx mobile app

Digital Therapeutics (DTx) are experiencing rapid advancements within mobile and mental healthcare sectors, with their ubiquity and enhanced accessibility setting them apart as uniquely effective solutions. In this evolving context, our research focuses on deep breathing, a vital technique in mental health management, aiming to optimize its application in DTx mobile platforms. Based on well-founded theories, we introduced a gamified and affordance-driven design, facilitating intuitive breath control. To enhance user engagement, we deployed the Mel Frequency Cepstral Coefficient (MFCC)-driven personalized machine learning method for accurate biofeedback visualization. To assess our design, we enlisted 70 participants, segregating them into a control and an intervention group. We evaluated Heart Rate Variability (HRV) metrics and collated user experience feedback. A key finding of our research is the stabilization of the Standard Deviation of the NN Interval (SDNN) within Heart Rate Variability (HRV), which is critical for stress reduction and overall health improvement. Our intervention group observed a pronounced stabilization in SDNN, indicating significant stress alleviation compared to the control group. This finding underscores the practical impact of our DTx solution in managing stress and promoting mental health. Furthermore, in the assessment of our intervention cohort, we observed a significant increase in perceived enjoyment, with a notable 22% higher score and 10.69% increase in positive attitudes toward the application compared to the control group. These metrics underscore our DTx solution's effectiveness in improving user engagement and fostering a positive disposition toward digital therapeutic efficacy. Although current technology poses challenges in seamlessly incorporating machine learning into mobile platforms, our model demonstrated superior effectiveness and user experience compared to existing solutions. We believe this result demonstrates the potential of our user-centric machine learning techniques, such as gamified and affordance-based approaches with MFCC, which could contribute significantly to the field of mobile mental healthcare.

Repetitive transcranial magnetic stimulation improves cardiovascular autonomic nervous system control: A meta-analysis

BACKGROUND

Cardiovascular autonomic system (ANS) may be affected by altered neural activations in the brain. This systematic review and meta-analysis investigated potential effects of repetitive transcranial magnetic stimulation (rTMS) protocols on cardiovascular ANS control.

METHODS

Through 19 qualified studies, we acquired 70 comparisons for data synthesis. Individual effect sizes were estimated by comparing changes in following cardiovascular ANS control variables between active and sham stimulation conditions: (a) blood pressure (BP), (b) heart rate (HR), and (c) heart rate variability (HRV). Moreover, two moderator variable analyses determined whether changes in cardiovascular ANS control were different based on (a) rTMS protocols (excitatory rTMS versus inhibitory rTMS) and (b) specific targeted cortical regions, respectively.

RESULTS

The random-effects model meta-analysis revealed significant improvements in cardiovascular ANS control after the rTMS protocols. Specifically, applying excitatory and inhibitory rTMS protocols significantly decreased values of BP and HR variables. For HRV variables, excitatory rTMS protocols showed significant positive effects. These improvements in cardiovascular ANS control were observed while applying either excitatory rTMS protocols to the left dorsolateral prefrontal cortex or inhibitory rTMS protocols to the right dorsolateral prefrontal cortex.

LIMITATIONS

Relatively small number of studies for inhibitory rTMS on the right dorsolateral prefrontal cortex were included in this meta-analysis.

CONCLUSION

These findings suggest that applying excitatory and inhibitory rTMS protocols on prefrontal cortical regions may be effective to improve cardiovascular ANS control.

Beliefs in Regulating Negative Emotions and Vagally Mediated Heart Rate Variability: Does Sex Make a Difference?

OBJECTIVE

This ecological study explored the association between regulatory emotional self-efficacy beliefs in managing negative emotions (RESE-NE) and heart rate variability (HRV), a measure of parasympathetic modulation of the heart that has been positively associated with a better ability to flexibly adjust to a changing environment and regulate emotions.

METHOD

To test these associations, we used data from 161 adults working in relational professions (about 40% men; mean [standard deviation] age = 40.45 [14.17] years) whose HRV was assessed continuously for 24 hours.

RESULTS

Individuals high in RESE-NE showed increased HRV levels ( β = -0.05, p = .011). However, this effect was moderated by biological sex ( β = -0.18, p = .0001) such that RESE-NE positively and significantly predicted HRV for men ( β = 0.18, p < .0001) but not for women ( β = -0.001, p = .989).

CONCLUSIONS

All in all, our study provides initial empirical support for the theoretical expectation derived from social cognitive theory that RESE-NE is positively correlated with a physiological indicator of adaptability to the environmental demands. This was true only for men, likely because of sex differences in physiological stress reactivity and regulation.

Cardiorespiratory fitness, regular physical activity, and autonomic nervous system reactivity to laboratory and daily life stress

The cross-stressor adaptation hypothesis-which posits that adjustment to physical stress as a result of regular physical activity and its effects on fitness crosses over to psychological stress reactivity-has been around for over four decades. However, the literature has been plagued by heterogeneities preventing definitive conclusions. We address these heterogeneity issues in a combined laboratory and daily life study of 116 young adults (M = 22.48 SD = 3.56, 57.76% female). The exposure, i.e., the potential driver of adaptation, was defined in three ways. First, a submaximal test was performed to obtain aerobic fitness measured as the VO₂ max (kg/ml/min). Second, leisure time exercise behavior, and third, overall moderate-to-vigorous physical activity (MVPA), were obtained from a structured interview. Outcomes were autonomic nervous system (ANS) reactivity and affective responsiveness to stressors. ANS activity was measured continuously and expressed as inter-beat-interval (IBI), pre-ejection-period (PEP), respiratory sinus arrythmia (RSA), and non-specific Skin Conductance Responses (ns.SCR). Negative and positive affect were recorded after each experimental condition in the laboratory and hourly in daily life with a nine-item digital questionnaire. Linear regressions were performed between the three exposure measures as predictors and the various laboratory and daily life stress measurements as outcomes. Our results support the resting heart rate reducing effect of aerobic fitness and total MVPA in both the laboratory and daily life. We did not find evidence for the cross-stressor adaptation hypothesis, irrespective of ANS or affective outcome measure or whether the exposure was defined as exercise/MVPA or aerobic fitness.

Effects of increased recirculation air rate and aircraft cabin occupancy on passengers' health and well-being - Results from a randomized controlled trial

BACKGROUND

Aircraft cabins are special environments. Passengers sit in close proximity in a space with low pressure that they cannot leave. The cabin is ventilated with a mixture of outside and recirculated air. The volume of outside air impacts the carbon footprint of flying. Higher recirculation air rates could be considered to save energy and divert less kerosene from producing thrust.

OBJECTIVES

To investigate whether higher recirculation air rates in aircraft cabins negatively affect passengers' health and well-being and if occupancy plays a role in this.

METHODS

In a 2 (occupancy: full and half-occupied) X 4 (ventilation regime) factorial design with stratified randomization, participants were exposed in an aircraft segment in a low-pressure tube during a 4-h simulated flight. Ventilation regimes consisted of increasing proportions of recirculated air up to a maximum CO₂ concentration of 4200 ppm. Participants rated comfort, health symptoms, and sleepiness multiple times. Heart rate (variability), as stress marker, was measured continuously.

RESULTS

559 persons representative of flight passengers regarding age (M = 42.7, SD = 15.9) and sex (283 men) participated. ANCOVA results showed hardly any effect of both factors on self-reported health symptoms, strong main effects of occupancy on comfort measures, and interaction effects for sleepiness and physiological stress parameters: Participants in the half-occupied cabin hardly reacted to increased recirculation air rates and show overall more favorable responses. Participants in the fully occupied cabin reported higher sleepiness and had stress reactions when the recirculation air rate was high.

DISCUSSION

This large-scale RCT shows the importance of occupancy, a previously neglected factor in indoor air research. The proximity of other people seems to increase stress and exacerbate reactions to air quality. Further studies on causal pathways are needed to determine if recirculation air rates can be increased to reduce the carbon footprint of flying without detrimental effects on passengers.

Reduced heart rate variability and expressive suppression interact to prospectively predict COVID-19 pandemic-related post-traumatic stress symptoms

The COVID-19 pandemic is a unique period of stress that, in some cases, led to post-traumatic stress symptoms (PTSSs). Emotion regulation strategies are known to modulate the emotional response to stressful events. Expressive suppression (ES) is a maladaptive strategy related to the exacerbation of the physiological stress response. Heart rate variability (HRV), an index of cardiac autonomic balance strictly related to ES, was also shown to predict PTSSs. This was the first study to investigate whether the pre-pandemic ES use and resting-state HRV predicted pandemic-related PTSSs. Before the pandemic, 83 (58 females) university students completed the Emotion Regulation Questionnaire (ERQ), self-report measures of anxiety and depressive symptoms, and a three-minute resting-state electrocardiogram recording. After 12 months, 61 (45 females) participants completed a self-report measure of pandemic-related PTSSs and repeated the self-report psychological measures. Pre-pandemic anxiety symptoms prospectively predicted greater PTSSs. Moreover, a significant interaction between HRV and ES in predicting PTSSs emerged, whereby those who had higher levels of ES and reduced HRV showed higher PTSSs. These findings suggest that an integrated assessment of HRV and ES might be useful for identifying individuals who are more vulnerable to the development of PTSSs during crises.

Early childhood stress responses to psychosocial stressors: The state of the science

The aim of this systematic review was to better understand whether and to what extent psychosocial stressors are associated with hypothalamic-pituitary-adrenal axis or autonomic nervous system stress responses in young children (1-6 years of age). Studies were classified by psychosocial stressors from the ecobiodevelopmental model: social and economic resources, maternal mental health, parent-child relationships, and the physical environment. Of the 2388 identified studies, 32 met full inclusion criteria, including over 9107 children. Child physiologic stress responses were measured as hair and urinary cortisol and cortisone, salivary diurnal and reactive cortisol, salivary reactive alpha-amylase, and respiratory sinus arrhythmia. There were 107 identified relations between psychosocial stressors and physiologic stress responses. Nearly two thirds of these relations suggested that children have dysregulated stress responses as either significantly blunted (n = 27) or increased (n = 37); 43 relations were not significant. Children most consistently had significantly dysregulated stress responses if they experienced postnatal maternal depression or anxiety. Some reasons for the mixed findings may be related to characteristics of the child (i.e., moderators) or stressor, how the stress response or psychosocial stressor was measured, unmeasured variables (e.g., caregiving buffering), researcher degrees of freedom, or publication bias.

A Human-in-the-loop Segmented Mixed-effects Modeling Method For Analyzing Wearables Data

Wearables are an important source of big data as they provide real-time high-resolution data logs of health indicators of individuals. Higher-order associations between pairs of variables is common in wearables data. Representing higher-order association curves as piece-wise linear segments in a regression model makes them more interpretable. However, existing methods for identifying the change points for segmented modeling either overfit or have low external validity for wearables data containing repeated measures. Therefore, we propose a human-in-the-loop method for segmented modeling of higher-order pairwise associations between variables in wearables data. Our method uses the smooth function estimated by a generalized additive mixed model to allow the analyst to annotate change point estimates for a segmented mixed-effects model, and thereafter employs the Brent's constrained optimization procedure to fine-tuning the manually provided estimates. We validate our method using three real-world wearables datasets. Our method not only outperforms state-of-the-art modeling methods in terms of prediction performance but also provides more interpretable results. Our study contributes to health data science in terms of developing a new method for interpretable modeling of wearables data. Our analysis uncovers interesting insights on higher order associations for health researchers.

Organizational justice and cardiometabolic disease: a systematic review

Abstract The effects of organizational justice on workers’ health have been investigated in several areas of work. However, the systematization of available information on the effects related to cardiovascular diseases (CVD) and diabetes is scarce. This article aims to systematically review the association between organizational justice and CVD and metabolic disease in adult workers. The search strategy included the terms organizational justice, coronary heart disease, cerebrovascular disease, systemic arterial hypertension, diabetes mellitus and CVD. This study investigated the following databases: MEDLINE, EMBASE, and LILACS. The quality of the studies was assessed using the instrument developed by the National Institute of Health. Results: This study identified 1,959 titles. After evaluation, eight studies were selected. Individuals with a high perception of organizational justice showed a lower risk of CVD and metabolic disease, whereas low organizational justice presented repercussions for the cardiovascular and metabolic health of workers. The development of strategies to promote organizational justice must be prioritized and thus mitigate its impacts on workers and institutions.

Organizational justice and cardiometabolic disease: a systematic review

The effects of organizational justice on workers' health have been investigated in several areas of work. However, the systematization of available information on the effects related to cardiovascular diseases (CVD) and diabetes is scarce. This article aims to systematically review the association between organizational justice and CVD and metabolic disease in adult workers. The search strategy included the terms organizational justice, coronary heart disease, cerebrovascular disease, systemic arterial hypertension, diabetes mellitus and CVD. This study investigated the following databases: MEDLINE, EMBASE, and LILACS. The quality of the studies was assessed using the instrument developed by the National Institute of Health. Results: This study identified 1,959 titles. After evaluation, eight studies were selected. Individuals with a high perception of organizational justice showed a lower risk of CVD and metabolic disease, whereas low organizational justice presented repercussions for the cardiovascular and metabolic health of workers. The development of strategies to promote organizational justice must be prioritized and thus mitigate its impacts on workers and institutions.

Physiological reactions to acute stressors and subjective stress during daily life: A systematic review on ecological momentary assessment (EMA) studies

OBJECTIVE

This review aims to provide an overview of ecological momentary assessment (EMA) studies analyzing stress reactivity during daily life in terms of direct and moderated influence of acute stress on physiological responses.

MATERIALS AND METHODS

A systematic literature search was performed on November 29, 2021 using Web of Science, MEDLINE and PsycINFO to identify prospective EMA studies targeting acute stressors or stress under naturalistic conditions, without restrictions of publication date or population. Study quality was assessed for multiple EMA-specific sources of bias.

RESULTS

Out of 4285 non-duplicate records, 107 publications involving 104 unique studies were included. The majority of studies assessed acute physiological stress responses primarily through salivary cortisol (n = 59) and cardiovascular outcomes (n = 32). Most studies performed at least three measurements per day (n = 59), and had a moderate risk of recall bias (n = 68) and confounding (n = 85). Fifty-four studies reported a compliance of ≥80%. Direct, non-moderated positive associations were observed between acute stress exposure and concurrent cortisol levels (44%, n = 11/25), systolic (44%, 8/18) and diastolic blood pressure (53%, 8/15) and heart rate (53%, 9/17). Several inter- and intra-individual moderators were identified, such as age, gender, health status, chronic stress, work-related resources, physical activity and stress coping indicators.

CONCLUSIONS

About half of the reviewed EMA studies demonstrated direct associations between everyday acute stress exposure and physiological responses, including increased cortisol levels, blood pressure and heart rate. Results further suggested various moderator variables that could help develop tailored prevention strategies and identify groups at higher risk for dysfunctional stress responses.

REGISTRATION

PROSPERO-Reg.-No.: PROSPERO 2020 CRD42020163178.

Differences in stress system (re-)activity between single and dual- or multitasking in healthy adults: A systematic review and meta-analysis

AbstractIn the age of digitization, multitasking requirements are ubiquitous, especially in the workplace. Multitasking (MT) describes the activity of performing multiple (at least two) tasks at the same time. Dual tasking (DT) refers to the sequential switching between two tasks. The aim of our systematic review and meta-analysis was first to investigate whether physiological stress systems become activated in response to or during MT/DT and, secondly, whether this (re-)activity is higher compared to single tasking. We focused on the Sympathetic Nervous System (SNS), the Parasympathetic Nervous System (PNS), the hypothalamic-pituitary adrenal (HPA) axis, and the immune system. The systematic review has been pre-registered with PROSPERO (CRD42020181415). A total of twenty-five articles were identified as eligible, in which n = 26 studies were reported, with N = 1,142 participants. Our main findings are that SNS activity is significantly higher and PNS activity is significantly lower during MT/DT than during single tasking. Only two studies were found, in which HPA axis (re-)activity was surveyed. No eligible study was identified in which immune system (re-)activity was investigated. This is the first systematic synthesis of the literature base showing that stress system activity is increased during MT/DT in comparison to single-tasking.

Stress Management Intervention for Leaders Increases Nighttime SDANN: Results from a Randomized Controlled Trial

Stress management interventions aim to reduce the disease risk that is heightened by work stress. Possible pathways of risk reduction include improvements in the autonomous nervous system, which is indexed by the measurement of heart rate variability (HRV). A randomized controlled trial on improving stress management skills at work was conducted to investigate the effects of intervention on HRV. A total of 174 lower management employees were randomized into either the waiting list control group (CG) or the intervention group (IG) receiving a 2-day stress management training program and another half-day booster after four and six months. In the trial, 24 h HRV was measured at baseline and after 12 months. Heart rate (HR), root mean square of successive differences (RMSSD), standard deviation of normal-to-normal intervals (SDNN), and standard deviation of the average of normal-to-normal intervals (SDANN) were calculated for 24 h and nighttime periods. Age-adjusted multilevel mixed effects linear regressions with unstructured covariance, time as a random coefficient, and time × group interaction with the according likelihood-ratio tests were calculated. The linear mixed-effect regression models showed neither group effects between IG and CG at baseline nor time effects between baseline and follow-up for SDANN (24 h), SDNN (24 h and nighttime), RMSSD (24 h and nighttime), and HR (24 h and nighttime). Nighttime SDANN significantly improved in the intervention group (z = 2.04, p = 0.041) compared to the control group. The objective stress axis measures (SDANN) showed successful stress reduction due to the training. Nighttime SDANN was strongly associated with minimum HR. Though the effects were small and only visible at night, it is highly remarkable that 3 days of intervention achieved a measurable effect considering that stress is only one of many factors that can influence HR and HRV.

Heart rate variability and heart rate monitoring of nurses using PPG and ECG signals during working condition: A pilot study

The use of wearable photoplethysmography (PPG) technology for estimating heart rate (HR) and HR variability (HRV) in the health care system is gaining attention in recent years. However, the performance of these devices remains questionable in their ability to collect data in real working conditions for long-term monitoring. The present study aimed to examine the data collected from nurses during working hours by PPG and electrocardiography (ECG) devices. Twenty-two nurses underwent a 60-minute work protocol during the normal working conditions while wearing a PPG device and an ECG device. HR, low-frequency component (LF) and high-frequency component (HF), LF/HF ratio, and percent LF distribution in total spectral power, and steps were examined. Pearson's correlation analysis and Bland-Altman method was performed to examine the relationships between the two devices based on HR and HRV indices. The results found strong positive correlations between HR estimates of both devices, and moderate correlations between LF/HF ratio and percent LF indices estimates, respectively. Moreover, the Bland-Altman analysis showed a small mean bias in general between the captured data of both devices. This pilot study suggested that the PPG device appears to demonstrate good overall reliability in measuring HR, LF/HF ratio, and percent LF. A further large-scale study is required to investigate the feasibility and practicality for HR and HRV analysis in nurses during real working conditions using PPG devices.

Heart Rate and Skin Conductance Associations with Physical Aggression, Psychopathy, Antisocial Personality Disorder and Conduct Disorder: An Updated Meta-Analysis

The associations between physiological measures (i.e., heart rate and skin conductance) of autonomic nervous system (ANS) activity and severe antisocial spectrum behavior (AB) were meta-analyzed. We used an exhaustive partitioning of variables relevant to the ANS-AB association and investigated four highly relevant questions (on declining effect sizes, psychopathy subscales, moderators, and ANS measures) that are thought to be transformative for future research on AB. We investigated a broad spectrum of physiological measures (e.g., heart rate (variability), pre-ejection period) in relation to AB. The search date for the current meta-analysis was on January 1^st, 2020, includes 101 studies and 769 effect sizes. Results indicate that effect sizes are heterogeneous and bidirectional. The careful partitioning of variables sheds light on the complex associations that were obscured in previous meta-analyses. Effects are largest for the most violent offenders and for psychopathy and are dependent on the experimental tasks used, parameters calculated, and analyses run. Understanding the specificity of physiological reactions may be expedient for differentiating between (and within) types of AB.

Fatigue, Stress, and Performance during Alternating Physical and Cognitive Tasks-Effects of the Temporal Pattern of Alternations

In occupational life, performing cognitive work tasks in between fatiguing physical work tasks may allow recovery and reduce stress without losing productive working time. The temporal pattern of such alternations is likely a determinant of the recovery effect, influencing both stress and fatigue; the difficulty of the cognitive task (CT) would also be a likely determinant. The aim of this study was to determine to what extent the temporal pattern of alternations between a repetitive physical task and a CT of different difficulties influenced perceived fatigability, performance fatigability, stress-related outcomes, and performance. Fifteen women performed four work sessions comprising 110 min of repeated bouts of a repetitive physical task (pipetting), alternating with a CT (n-back). Sessions differed in bout cycle time (short: 7 + 3 min versus long: 14 + 6 min) and CT difficulty (CTdiff; easy versus difficult). Fatigue was assessed from recordings of maximal voluntary contraction force in shoulder elevations and handgrip pre- and post-work, electromyography (EMG) from the right trapezius and right forearm extensors during work, and repeated self-ratings of fatigue and pain throughout the session. Stress was assessed using electrocardiography (heart rate variability), salivary alpha-amylase, and self-reports. Perceived fatigue increased significantly over time for all protocols and more in long-cycle than short-cycle conditions. EMG activity did not increase markedly over time in any condition. Neither objective nor subjective indicators suggested that stress increased over time, regardless of the temporal pattern. Pipetting performance remained stable in all conditions. Cognitive performance, measured by the proportions of correct positive and false positive answers, differed between CTdiff levels but remained stable over time, with no significant difference between temporal patterns. In summary, temporal patterns of alternating tasks influenced fatigue to some extent but had no obvious influence on stress indicators or performance. Thus, designing job rotation with alternating physical and cognitive work should consider the temporal patterns of alternations to minimize fatigue.

Personal Resources and Organizational Outcomes: Sex as a Moderator of the Complex Relationships Between Self-Esteem, Heart Rate Variability, and Work-Related Exhaustion

Global self-esteem represents a protective personal resource lowering the risk of psychological distress. Research conducted in the work setting has confirmed the psychosocial benefits of high self-esteem. However, research linking self-esteem to neurobiological adaptability appears quite scarce. In this study, we propose a theoretical model in which self-esteem predicts work-related exhaustion indirectly, through the mediation of heart rate variability (HRV) and negative affect at work. Moreover, we explore the relationship between self-esteem and HRV. From one side, one would expect a positive link between self-esteem and HRV, signaling higher autonomic adaptability. However, recent studies have shown that in women, such associations become more complex, with even reversed patterns as compared with that in men. Thus, we included sex as a moderator of the relationship between HRV and self-esteem. The model was tested on a sample of 110 individuals working in the relational professions (54% males; M _age = 42.6, SD = 13.73), observed for an entire workday. Results confirmed the protective role of self-esteem against the experience of negative affect and (indirectly) work-related exhaustion. Symptoms of exhaustion at work were also negatively predicted by HRV, and both HRV and negative affect acted as mediators of the relationship between self-esteem and work-related exhaustion. Notably, sex differences emerged in the association between global self-esteem and cardiac vagal tone at work: in women, self-esteem was negatively related to HRV, which in turn led to higher work-related exhaustion, whereas in men, no evidence of this indirect effect appeared. Burnout prevention programs should not ignore important sex differences in how individuals respond to work-related stress.

Heart Rate Variability in Different Levels of Burnout-Cross-Sectional Study of Different Occupational Groups Heart Rate Variability and Burnout

OBJECTIVES

The aim of this study was a subjective and objective stress analysis of occupational groups.

METHODS

The study examined 414 employees with patients or children contact on work. The age ranged from 22 to 63 years. Subjective stress was measured using the Maslach Burnout Inventory and objective stress with heart rate variability (HRV).

RESULTS

Twenty-one percent of subjects showed a high level of exhaustion, 12.9% a high level of cynicism and low performance. There were significant group differences between cynicism levels in meanNN (P = .008) and meanHR (P = .002). There were no significant differences in HRV for exhaustion and professional efficacy.

CONCLUSIONS

The health-impairing manifestations of the three dimensions of the burnout syndrome are not associated with the lower HRV. However, healthy subjects from a "screening" study who had not been clinically diagnosed with burnout were examined here.

Global, regional, and national burdens of ischemic heart disease and stroke attributable to exposure to long working hours for 194 countries, 2000-2016: A systematic analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

World Health Organization (WHO) and International Labour Organization (ILO) systematic reviews reported sufficient evidence for higher risks of ischemic heart disease and stroke amongst people working long hours (≥55 hours/week), compared with people working standard hours (35-40 hours/week). This article presents WHO/ILO Joint Estimates of global, regional, and national exposure to long working hours, for 194 countries, and the attributable burdens of ischemic heart disease and stroke, for 183 countries, by sex and age, for 2000, 2010, and 2016.

METHODS AND FINDINGS

We calculated population-attributable fractions from estimates of the population exposed to long working hours and relative risks of exposure on the diseases from the systematic reviews. The exposed population was modelled using data from 2324 cross-sectional surveys and 1742 quarterly survey datasets. Attributable disease burdens were estimated by applying the population-attributable fractions to WHO's Global Health Estimates of total disease burdens.

RESULTS

In 2016, 488 million people (95% uncertainty range: 472-503 million), or 8.9% (8.6-9.1) of the global population, were exposed to working long hours (≥55 hours/week). An estimated 745,194 deaths (705,786-784,601) and 23.3 million disability-adjusted life years (22.2-24.4) from ischemic heart disease and stroke combined were attributable to this exposure. The population-attributable fractions for deaths were 3.7% (3.4-4.0) for ischemic heart disease and 6.9% for stroke (6.4-7.5); for disability-adjusted life years they were 5.3% (4.9-5.6) for ischemic heart disease and 9.3% (8.7-9.9) for stroke.

CONCLUSIONS

WHO and ILO estimate exposure to long working hours (≥55 hours/week) is common and causes large attributable burdens of ischemic heart disease and stroke. Protecting and promoting occupational and workers' safety and health requires interventions to reduce hazardous long working hours.

Moderation of the Stressor-Strain Process in Interns by Heart Rate Variability Measured with a Wearable and Smartphone App: a Within-Subject Design Using Continuous Monitoring

Background

The emergence of smartphones and wearable sensor technologies enables easy and unobtrusive monitoring of physiological and psychological data related to an individual’s resilience. Heart rate variability (HRV) is a promising biomarker for resilience based on between-subject population studies, but observational studies that apply a within-subject design and use wearable sensors in order to observe HRV in a naturalistic real-life context are needed.

Objective

This study aims to explore whether resting HRV and total sleep time (TST) are indicative and predictive of the within-day accumulation of the negative consequences of stress and mental exhaustion. The tested hypotheses are that demands are positively associated with stress and resting HRV buffers against this association, stress is positively associated with mental exhaustion and resting HRV buffers against this association, stress negatively impacts subsequent-night TST, and previous-evening mental exhaustion negatively impacts resting HRV, while previous-night TST buffers against this association.

Methods

In total, 26 interns used consumer-available wearables (Fitbit Charge 2 and Polar H7), a consumer-available smartphone app (Elite HRV), and an ecological momentary assessment smartphone app to collect resilience-related data on resting HRV, TST, and perceived demands, stress, and mental exhaustion on a daily basis for 15 weeks.

Results

Multiple linear regression analysis of within-subject standardized data collected on 2379 unique person-days showed that having a high resting HRV buffered against the positive association between demands and stress (hypothesis 1) and between stress and mental exhaustion (hypothesis 2). Stress did not affect TST (hypothesis 3). Finally, mental exhaustion negatively predicted resting HRV in the subsequent morning but TST did not buffer against this (hypothesis 4).

Conclusions

To our knowledge, this study provides first evidence that having a low within-subject resting HRV may be both indicative and predictive of the short-term accumulation of the negative effects of stress and mental exhaustion, potentially forming a negative feedback loop. If these findings can be replicated and expanded upon in future studies, they may contribute to the development of automated resilience interventions that monitor daily resting HRV and aim to provide users with an early warning signal when a negative feedback loop forms, to prevent the negative impact of stress on long-term health outcomes.

Autonomic dysfunction and heart rate variability with Holter monitoring: a diagnostic look at autonomic regulation

Heart rate variability (HRV) refers to the beat-to-beat variation of the cardiac cycle. Since heart rate is modulated on a beat-to-beat basis by the combined influence of the sympathetic and parasympathetic nervous system at the sinus node level, HRV has been considered an indirect biomarker of cardiac autonomic control and widely exploited for the assessment of autonomic function in many pathological subjects. This focus article summarizes the main findings derived from HRV analysis applied to 24‑h Holter monitoring in both cardiac and non-cardiac diseases as well as in physiological conditions in the healthy population. Even if the prognostic role of HRV indices is well recognized and its use ever more widespread, its implementation in the diagnostic and prognostic processes in routine clinical practice remains limited. Several reasons for these limitations can be identified: first the lack of reliable reference values, and secondly, the low specificity of HRV indices in particular when considering the constant evolution of clinical practice and therapeutic approaches, making it difficult to refer to a specific and stable combination of clinical and HRV markers. Therefore, the clinical use of HRV should be further investigated. Finally, HRV represents a substantial tool for investigating the physiological conditions in healthy people that can have important implications in primary prevention and the understanding of gender differences, as well as in sport and occupational medicine.

The streamlined allostatic load index is associated with perceived stress in life - findings from the MIDUS study

The wear and tear of the body caused by stressful events is subject of extensive research and can be measured by the allostatic load index (ALI). The aim of this cross-sectional study was to replicate an ALI-5 score in a population sample in the USA and to compare these findings with the original ALI-10 score. Data from the Midlife in the United States Study (MIDUS) assessed between 2004 and 2016 were used to calculate different ALI risk scores with 5 and 10 variables, respectively. Examinations included anthropometric data, heart rate variability (HRV), and blood and urine samples. Questionnaires assessed information on perceived stress and medical history. Logistic regression models estimated odds ratios (OR) with corresponding 95% confidence intervals (CIs) for the association between ALI indices and perceived stress, controlling for various confounders. Subgroup analysis explored the difference in gender and in three age clusters. Data of 1421 participants (43% male, 50.4 ± 9.3 years) were included in the analysis. Adjusted logistic regression models showed an odds ratio of 1.37 ± 0.19 (CI 1.05, 1.80; p=.022) for the association of ALI-5 with perceived stress. This association was stronger in females (OR = 1.62 ± 0.28, CI 1.15, 2.28; p = .006) and did not significantly differ between age clusters. Results for the original ALI-10 score did not reach significance. The streamlined ALI-5 score seems to be a reliable risk score and is strongly associated with perceived stress in life. Longitudinal studies should further elaborate this association in different samples.Lay summary: Stress from different sources can lead to serious diseases. A short composite index comprising of five medical variables is highly associated with perceived stress. This index is able to serve as an early indicator to detect people who are at risk to develop stress-related diseases.

Towards a biochemical approach to occupational stress management

Given the immense and growing cost of occupational stress to society through lost productivity and the burden to healthcare systems, current best practices for detecting, managing and reducing stress in the workplace are clearly sub-optimal and substantially better methods are required. Subjective, self-reported psychology and psychiatry-based instruments are prone to biases whereas current objective, biology-based measures produce conflicting results and are far from reliable. A multivariate approach to occupational stress research is required that reflects the broad, coordinated, physiological response to demands placed on the body by exposure to diverse occupational stressors. A literature review was conducted to determine the extent of application of the emerging multivariate technology of metabolomics to occupational stress research. Of 170 articles meeting the search criteria, three were identified that specifically studied occupational stressors using metabolomics. A further ten studies were not specifically occupational or were of indirect or peripheral relevance. The occupational studies, although limited in number highlight the technological challenges associated with the application of metabolomics to investigate occupational stress. They also demonstrate the utility to evaluate stress more comprehensively than univariate biomarker studies. The potential of this multivariate approach to enhance our understanding of occupational stress has yet to be established. This will require more studies with broader analytical coverage of the metabolome, longitudinal sampling, combination with experience sampling methods and comparison with psychometric models of occupational stress. Progress will likely involve combining multi-omic data into a holistic, systems biology approach to detecting, managing and reducing occupational stress and optimizing workplace performance.

Shift Work Adaptation Among Police Officers: The BCOPS Study

Few studies have examined shiftwork adaptation among police officers or potential differences in disease biomarkers among adapted and maladapted shiftworkers. This study characterized shiftwork adaptation among 430 police officers from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study. Police officers working fixed night shifts with symptoms characteristic of adaptation and maladaptation were identified using latent class analysis (n = 242). Two approaches were applied, one with police-specific symptoms and another using more general symptoms as shiftwork adaptation indicators. Biomarkers of inflammation, heart rate variability, and cardiometabolic risk were then compared between shiftwork adaptation groups, and with officers working day shifts, after adjusting for confounding. When analyses included police-specific symptoms, maladapted shiftworkers (n = 73) had more self-reported stress, sleep disturbances, fatigue, and less social support than adapted shiftworkers (n = 169). Using more general symptoms, maladapted officers (n = 56) reported more stress and depression, and less social support than adapted officers (n = 186). In police-specific models, adjusted (least-squares) means (± standard error) of circulating interleukin-6 (IL-6) concentrations in maladapted officers (0.8 ± 0.1 ln[pg/ml]) were modestly elevated relative to adapted shiftworkers (0.7 ± 0.1 ln[pg/ml], p = .09) and relative to permanent day workers (0.5 ± 0.1 ln[pg/ml], p ≤ 0.01), and leptin levels in maladapted officers (9.6 ± 0.1 ln[pg/ml]) exceeded those in the adapted (9.4 ± 0.1 ln[pg/ml], p ≤ 0.01) and day shift groups (9.4 ± 0.1 ln[pg/ml], p = .03). In the general model, adjusted mean tumor necrosis factor-alpha (TNF-α) concentrations among maladapted officers (5.6 ± 0.23 pg/ml) exceeded the adapted (4.8 ± 0.2 pg/ml, p ≤ 0.01) and day workers (5.0 ± 0.2 pg/ml, p = .04), and insulin among maladapted officers was higher (2.4 ± 0.1 ln[uu/ml]) than the adapted group (1.8 ± 0.1 ln[uu/ml], p = .03). No differences were observed for the other biomarkers. The results suggest that maladaptation among police officers working fixed night shifts may lead to increases in leptin, insulin, IL-6, and TNF-α; however, the cross-sectional design and possible residual confounding preclude interpretation of cause and effect. Prospective studies are planned to further characterize the relationship between shiftwork maladaptation and biomarkers of chronic disease risk in this police officer cohort.

Transcranial Direct Current Stimulation (tDCS) Augments the Effects of Gamified, Mobile Attention Bias Modification

Anxiety-related attention bias (AB) is the preferential processing of threat observed in clinical and sub-clinical anxiety. Attention bias modification training (ABMT) is a computerized cognitive training technique designed to systematically direct attention away from threat and ameliorate AB, but mixed and null findings have highlighted gaps in our understanding of mechanisms underlying ABMT and how to design the most effective delivery systems. One neuromodulation technique, transcranial direct current stimulation (tDCS) across the pre-frontal cortex (PFC) may augment the effects of ABMT by strengthening top-down cognitive control processes, but the evidence base is limited and has not been generalized to current approaches in digital therapeutics, such as mobile applications. The present study was a single-blind randomized sham-controlled design. We tested whether tDCS across the PFC, vs. sham stimulation, effectively augments the beneficial effects of a gamified ABMT mobile app. Thirty-eight adults (Mage = 23.92, SD = 4.75; 18 females) evidencing low-to-moderate anxiety symptoms were randomly assigned to active or sham tDCS for 30-min while receiving ABMT via a mobile app. Participants reported on potential moderators of ABMT, including life stress and trait anxiety. ECG was recorded during a subsequent stressor to generate respiratory sinus arrhythmia (RSA) suppression as a metric of stress resilience. ABMT delivered via the app combined with tDCS (compared to sham) reduced AB and boosted stress resilience measured via RSA suppression, particularly for those reporting low life stress. Our results integrating tDCS with ABMT provide insight into the mechanisms of AB modulation and support ongoing evaluations of enhanced ABMT reliability and effectiveness via tDCS.

Structural covariance of the salience network associated with heart rate variability

The salience network (SN) anchored by the anterior insula and cingulate is crucial for the autonomic control of body homeostasis. Resting-sate fMRI studies have linked intrinsic SN connectivity with multiple autonomic measures, but little is known about the structural organization of this system relating to cardiac vagal function. To address the above issue, the current study used covariance analysis of MRI-based gray matter volume (GMV) to map structural covariance of SN with two independent datasets, and then determined whether interregional structural connections within SN related to individual differences in vagally-mediated heart rate variability (HRV). The results showed a significant positive association between structural covariance of the SN and vagal component of HRV in two independent samples. More importantly, the conjunction and pooled data analysis revealed that structural correlation from left anterior insula to dorsal anterior cingulate cortex positively interacted with vagally-mediated HRV. The current results demonstrated a crucial role of the SN in the cortical modulation of efferent vagal activity to the heart, and provided new insight into structural neural network implicated in cardiac vagal control.

How the first years of motherhood impact the cardiac autonomic profile of female healthcare professionals: a study by heart rate variability analysis

The conciliation between career and family is a relevant issue for working women, in particular during the first years of motherhood. Data about the state of the cardiac autonomic regulation in working women with preschoolers are lacking. Aim of this study was to compare the cardiac autonomic profile of female healthcare professionals with and without preschoolers via the analysis of the variability of the time distance between two consecutive R-wave peaks (RR) from standard 24-h Holter electrocardiogram (ECG). Fifty healthy active female healthcare professionals were enrolled: 25 with at least one preschooler (W_KID) and 25 without (W_NOKID). A standard Holter ECG was obtained during a regular working day. Segments of 5000 consecutive RRs were selected during daytime (DAY) and nighttime (NIGHT). Heart rate variability analysis was performed and the following parameters were considered for comparison between the two groups: mean (μ_RR), variance (σ²_RR), and the absolute power in high frequency component (HF) of RR (HF_RR) series. HF_RR was considered as a marker of vagal cardiac modulation. Only µ_RR significantly increased from DAY to NIGHT in both groups (699 ± 88 vs 887 ± 140 ms in W_KID and 728 ± 90 vs 942 ± 166 ms in W_NOKID). Instead, σ²_RR and HF_RR increased from DAY to NIGHT only in W_NOKID (from 3334 ± 2153 to 4816 ± 4063 ms² and from 356 ± 334 to 1397 ± 1629 ms², respectively). W_KID showed lower σ²_RR and HF_RR during NIGHT, compared to W_NOKID (2336 ± 3170 vs 4816 ± 4063 ms² and 556 ± 950 vs 1397 ± 1629 ms², respectively). The perceived stress according to the visual analogue scale was similar in the two groups (4.7 ± 2.1 in W_KID, 5.7 ± 2.1 in W_NOKID). The presence of preschoolers lowered nocturnal cardiac vagal modulation in female healthcare professionals. This might represent an adaptation with a finalistic purpose, scilicet the facilitation of a prompt reaction in case of a child’s need.

Stress and aging: A neurovisceral integration perspective

Darwin emphasized the intimate relationship between the brain and the heart over 150 years ago. Healthy aging is associated with significant changes in both the brain and the heart. The changes between these, the two most important organs of the body, are linked via the vagus nerve. In this review, we examine the normative changes with aging and the effect that stress may have on how the brain-heart connection changes with age. We provide a framework based on the concept of neurovisceral integration and propose that stress regulation is emotion regulation. As such, studies that have investigated emotion regulation may yield insights into successful stress regulation that helps protect people from age-related decline. In addition, interventions that improve brain health also improve heart health and vice versa. We conclude by noting that significant sex and ethnic differences exist but that future studies are needed to more fully explicate how they may moderate the associations between stress and aging.

24 h-Heart Rate Variability as a Communication Tool for a Personalized Psychosomatic Consultation in Occupational Health

New tools for non-specific primary prevention strategies covering somatic and mental health in occupational medicine are urgently needed. Heart rate variability (HRV) reflects the capacity of the body to adapt to environmental challenges and of the mind to regulate emotions. Hence, a 24 h-measurement of HRV offers a unique possibility to quantify the interaction between situation-specific emotional regulation within a specific psychosocial environment and physiological state, thereby increasing self-perception and inducing motivation to change behavior. The focus of the present study represents such a 24 h-measurement of HRV and its presentation as a comprehensive graph including protocol situations of the client. A special training program for occupational health physicians and questionnaires for clients were developed and administered. The article reports the first data of the study “healthy leadership and work – body signals for managers and employees”, an investigator-initiated, interventional, single-arm, open (non-blinded), multicenter, national trial with 168 participants. They reported a significantly improved perception of their bodily needs after the consultation (from Median = 7, interquartile range 5–8 to Median = 8, interquartile range 7–9; scale range from 1 to 10; p < 0.001, Wilcoxon rank test; effect size 0.49). The 16 occupational health physicians stated that the measurement of HRV was very well suited to enter into dialog with the managers and was feasible to show interactions between situations, thoughts, feelings, and bodily reactions. Taken together, we show that a 24 h-HRV-measurement can be a feasible and effective approach for holistic, psychosomatic primary prevention in occupational medicine. We discuss possible mechanisms for improving the individual health via the consultation, containing mindset and improved ANS activity.

Association Between Psychological Distress and Stress-Related Symptoms and Increased Risk of Type 2 Diabetes in Male Individuals: An Observational Study

Background

This study evaluated the association between psychological distress and development of type 2 diabetes (T2D) among male individuals in the workplace.

Methods

This observational cohort study enrolled 6,326 male participants aged 18 - 65 years (mean age 47.4 ± 9.5 years, body mass index 23.4 ± 3.4 kg/m², hemoglobin A1c 5.5±0.3%), who received annual health checkups from April 2016 to March 2017. Those who had a hemoglobin A1c level ≥ 6.5%, previous history of diabetes, or used diabetes medication were excluded from the analysis. Psychological distress was measured using the Brief Job Stress Questionnaire. Multivariate Cox proportional hazard regression models were used to estimate the development of T2D in relation to psychological distress and stress-related symptoms. The calculated hazard ratio (aHR) was adjusted for age, body mass index, and hemoglobin A1c level.

Results

During a mean follow-up period of 1.9 years, the incidence rate of new-onset T2D was 2.0%. Baseline psychological parameters did not differ between participants with or without new-onset T2D. Depression was associated with an increased risk of T2D (aHR = 1.54, 95% confidence interval (CI): 1.07 - 2.22), whereas vigor, irritation, fatigue, and anxiety were not. Moreover, inability to handle work (aHR = 2.18, 95% CI: 1.14 - 4.19), sadness (aHR = 1.93, 95% CI: 1.14 - 3.26), headache (aHR = 1.98, 95% CI: 1.18 - 3.34), shoulder stiffness (aHR = 1.56, 95% CI: 1.10 - 2.23), and constipation/diarrhea (aHR = 1.71, 95% CI: 1.04 - 2.80) were associated with T2D incidence.

Conclusions

Depression and stress-related symptoms were associated with an increased risk of T2D. Industrial physicians and health care providers should evaluate these factors during health checkups to lower the T2D incidence in this population

Detection and Characterization of Physical Activity and Psychological Stress from Wristband Data

Wearable devices continuously measure multiple physiological variables to inform users of health and behavior indicators. The computed health indicators must rely on informative signals obtained by processing the raw physiological variables with powerful noise- and artifacts-filtering algorithms. In this study, we aimed to elucidate the effects of signal processing techniques on the accuracy of detecting and discriminating physical activity (PA) and acute psychological stress (APS) using physiological measurements (blood volume pulse, heart rate, skin temperature, galvanic skin response, and accelerometer) collected from a wristband. Data from 207 experiments involving 24 subjects were used to develop signal processing, feature extraction, and machine learning (ML) algorithms that can detect and discriminate PA and APS when they occur individually or concurrently, classify different types of PA and APS, and estimate energy expenditure (EE). Training data were used to generate feature variables from the physiological variables and develop ML models (naïve Bayes, decision tree, k-nearest neighbor, linear discriminant, ensemble learning, and support vector machine). Results from an independent labeled testing data set demonstrate that PA was detected and classified with an accuracy of 99.3%, and APS was detected and classified with an accuracy of 92.7%, whereas the simultaneous occurrences of both PA and APS were detected and classified with an accuracy of 89.9% (relative to actual class labels), and EE was estimated with a low mean absolute error of 0.02 metabolic equivalent of task (MET).The data filtering and adaptive noise cancellation techniques used to mitigate the effects of noise and artifacts on the classification results increased the detection and discrimination accuracy by 0.7% and 3.0% for PA and APS, respectively, and by 18% for EE estimation. The results demonstrate the physiological measurements from wristband devices are susceptible to noise and artifacts, and elucidate the effects of signal processing and feature extraction on the accuracy of detection, classification, and estimation of PA and APS.

The Immediate Effects of Lavender Aromatherapy Massage versus Massage in Work Stress, Burnout, and HRV Parameters: A Randomized Controlled Trial

Background

Occupational stress is a common issue faced by workers in every discipline. Complementary and alternative medicine (CAM) therapies, such as aromatherapy massage or massage, have antistress effects in the literature. The purpose of this randomized clinical trial with triple blinds is to evaluate the immediate effects of lavender aromatherapy massage for improving work stress, burnout, and HRV parameters of female employees in a university.

Methods

A total of 53 subjects in experimental group whereas 57 subjects in control group completed interventions and measurement and led to power of 0.98. Inferential statistics, as independent t-test, paired t-test, and Chi-Square test, were performed to verify the expected relationships.

Results

The present study found that subjects in experimental group reported a lower role stress and less inclined to type A personality trait after aromatherapy massage with lavender. For control group, only less inclined to type A personality trait was reported after receiving massage. For burnout, a significant lower personal burnout and work-related burnout were reported after aromatherapy massage whereas only increased client-related burnout was reported in control group. For HRV, both the experimental and control groups reported higher SDNN and RMSSD in time domain after intervention. Contradictory HRT and PSI in time domain were significantly lower after intervention. In frequency domain of HRV, both groups reported significantly higher value in VLF and HF. In addition, the experimental group reported significantly higher value in TP and LF after intervention.

Conclusions

Both the lavender aromatherapy massage and massage did show immediate effect on different dimensions of work stress, burnout, and HRV. These two interventions can be applied as routine leisure activities by personal preference to reduce stresses occurring in work environment.

Stress-Related Responses to Alternations between Repetitive Physical Work and Cognitive Tasks of Different Difficulties

Alternating between physical and cognitive tasks has been proposed as an alternative in job rotation, allowing workers to recover from the physical work while still being productive. However, effects of such alternations on stress have not been investigated. This controlled experiment aimed at determining the extent to which stress-related responses develop during alternating physical and cognitive work, and to determine the extent to which cognitive task (CT) difficulty influences these responses. Fifteen women performed three sessions of 10 consecutive work bouts each including a seven-minute repetitive physical task (pipetting) and a three-minute CT (n-back) at one of three difficulty levels. Stress was assessed in terms of changes in heart rate variability, blood pressure, salivary alpha-amylase, salivary cortisol, perceived stress, and cognitive performance. The work session did not result in any marked stress response, and CT difficulty did not significantly influence stress, apart from alpha-amylase being higher at the easiest CT (F = 5.34, p = 0.02). Thus, according to our results, alternating between repetitive physical tasks and cognitive tasks may be a feasible alternative to classic job rotation between physical tasks only, even if the cognitive task is quite difficult. Future studies should address possible effects of the temporal pattern of alternations, and combine even other occupationally relevant tasks, preferably for extended periods of time.

Assessment of a dive incident using heart rate variability

INTRODUCTION

Scuba diving likely has an impact on the autonomic nervous system (ANS). In the course of conducting trials of underwater ECG recording for measurement of heart rate variability, there was an unexpected stressful event; one participant's regulator iced and began to free-flow.

METHODS

A custom-made, water- and pressure-tight aluminum housing was used to protect a portable Holter monitor. ECGs were recorded in three experienced divers who witnessed an unplanned moderately stressful incident during diving. The ECG signals were analysed for measures of heart rate variability (HRV).

RESULTS

Analysis for different short-term HRV measures provided consistent results if periods of interest were appropriately time-aligned. There was improvement in sympatho-vagal balance. One diver unexpectedly exhibited an increase in both sympathetic and vagal activity shortly after the incident.

CONCLUSIONS

A conventional open-water dive affected the ANS of experienced recreational divers as measured by HRV which provides a global evaluation of the ANS and alterations in its two branches. The heart rate variability data gathered from several participating divers around the time of this event illustrate the potential utility of this variable in quantifying stress during diving. HRV data may be useful in addressing relevant diving related questions such as effects of cold, exercise or different breathing gases on ANS function.

Validity of the Empatica E4 Wristband to Measure Heart Rate Variability (HRV) Parameters: a Comparison to Electrocardiography (ECG)

Wearable monitoring devices are an innovative way to measure heart rate (HR) and heart rate variability (HRV), however, there is still debate about the validity of these wearables. This study aimed to validate the accuracy and predictive value of the Empatica E4 wristband against the VU University Ambulatory Monitoring System (VU-AMS) in a clinical population of traumatized adolescents in residential care. A sample of 345 recordings of both the Empatica E4 wristband and the VU-AMS was derived from a feasibility study that included fifteen participants. They wore both devices during two experimental testing and twelve intervention sessions. We used correlations, cross-correlations, Mann-Whitney tests, difference factors, Bland-Altman plots, and Limits of Agreement to evaluate differences in outcomes between devices. Significant correlations were found between Empatica E4 and VU-AMS recordings for HR, SDNN, RMSSD, and HF recordings. There was a significant difference between the devices for all parameters but HR, although effect sizes were small for SDNN, LF, and HF. For all parameters but RMSSD, testing outcomes of the two devices led to the same conclusions regarding significance. The Empatica E4 wristband provides a new opportunity to measure HRV in an unobtrusive way. Results of this study indicate the potential of the Empatica E4 as a practical and valid tool for research on HR and HRV under non-movement conditions. While more research needs to be conducted, this study could be considered as a first step to support the use of HRV recordings provided by wearables.

Stress and Health: A Review of Psychobiological Processes

The cumulative science linking stress to negative health outcomes is vast. Stress can affect health directly, through autonomic and neuroendocrine responses, but also indirectly, through changes in health behaviors. In this review, we present a brief overview of (a) why we should be interested in stress in the context of health; (b) the stress response and allostatic load; (c) some of the key biological mechanisms through which stress impacts health, such as by influencing hypothalamic-pituitary-adrenal axis regulation and cortisol dynamics, the autonomic nervous system, and gene expression; and (d) evidence of the clinical relevance of stress, exemplified through the risk of infectious diseases. The studies reviewed in this article confirm that stress has an impact on multiple biological systems. Future work ought to consider further the importance of early-life adversity and continue to explore how different biological systems interact in the context of stress and health processes.

The effect of exposure to long working hours on ischaemic heart disease: A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) are developing Joint Estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates), with contributions from a large network of experts. Evidence from mechanistic data suggests that exposure to long working hours may cause ischaemic heart disease (IHD). In this paper, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from IHD that are attributable to exposure to long working hours, for the development of the WHO/ILO Joint Estimates.

OBJECTIVES

We aimed to systematically review and meta-analyse estimates of the effect of exposure to long working hours (three categories: 41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on IHD (three outcomes: prevalence, incidence and mortality).

DATA SOURCES

We developed and published a protocol, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic databases for potentially relevant records from published and unpublished studies, including MEDLINE, Scopus, Web of Science, CISDOC, PsycINFO, and WHO ICTRP. We also searched grey literature databases, Internet search engines and organizational websites; hand-searched reference lists of previous systematic reviews; and consulted additional experts.

STUDY ELIGIBILITY AND CRITERIA

We included working-age (≥15 years) workers in the formal and informal economy in any WHO and/or ILO Member State but excluded children (aged < 15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies which contained an estimate of the effect of exposure to long working hours (41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on IHD (prevalence, incidence or mortality).

STUDY APPRAISAL AND SYNTHESIS METHODS

At least two review authors independently screened titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. Missing data were requested from principal study authors. We combined relative risks using random-effect meta-analysis. Two or more review authors assessed the risk of bias, quality of evidence and strength of evidence, using Navigation Guide and GRADE tools and approaches adapted to this project.

RESULTS

Thirty-seven studies (26 prospective cohort studies and 11 case-control studies) met the inclusion criteria, comprising a total of 768,751 participants (310,954 females) in 13 countries in three WHO regions (Americas, Europe and Western Pacific). The exposure was measured using self-reports in all studies, and the outcome was assessed with administrative health records (30 studies) or self-reported physician diagnosis (7 studies). The outcome was defined as incident non-fatal IHD event in 19 studies (8 cohort studies, 11 case-control studies), incident fatal IHD event in two studies (both cohort studies), and incident non-fatal or fatal ("mixed") event in 16 studies (all cohort studies). Because we judged cohort studies to have a relatively lower risk of bias, we prioritized evidence from these studies and treated evidence from case-control studies as supporting evidence. For the bodies of evidence for both outcomes with any eligible studies (i.e. IHD incidence and mortality), we did not have serious concerns for risk of bias (at least for the cohort studies). No eligible study was found on the effect of long working hours on IHD prevalence. Compared with working 35-40 h/week, we are uncertain about the effect on acquiring (or incidence of) IHD of working 41-48 h/week (relative risk (RR) 0.98, 95% confidence interval (CI) 0.91 to 1.07, 20 studies, 312,209 participants, I² 0%, low quality of evidence) and 49-54 h/week (RR 1.05, 95% CI 0.94 to 1.17, 18 studies, 308,405 participants, I² 0%, low quality of evidence). Compared with working 35-40 h/week, working ≥55 h/week may have led to a moderately, clinically meaningful increase in the risk of acquiring IHD, when followed up between one year and 20 years (RR 1.13, 95% CI 1.02 to 1.26, 22 studies, 339,680 participants, I² 5%, moderate quality of evidence). Compared with working 35-40 h/week, we are very uncertain about the effect on dying (mortality) from IHD of working 41-48 h/week (RR 0.99, 95% CI 0.88 to 1.12, 13 studies, 288,278 participants, I² 8%, low quality of evidence) and 49-54 h/week (RR 1.01, 95% CI 0.82 to 1.25, 11 studies, 284,474 participants, I² 13%, low quality of evidence). Compared with working 35-40 h/week, working ≥55 h/week may have led to a moderate, clinically meaningful increase in the risk of dying from IHD when followed up between eight and 30 years (RR 1.17, 95% CI 1.05 to 1.31, 16 studies, 726,803 participants, I² 0%, moderate quality of evidence). Subgroup analyses found no evidence for differences by WHO region and sex, but RRs were higher among persons with lower SES. Sensitivity analyses found no differences by outcome definition (exclusively non-fatal or fatal versus "mixed"), outcome measurement (health records versus self-reports) and risk of bias ("high"/"probably high" ratings in any domain versus "low"/"probably low" in all domains).

CONCLUSIONS

We judged the existing bodies of evidence for human evidence as "inadequate evidence for harmfulness" for the exposure categories 41-48 and 49-54 h/week for IHD prevalence, incidence and mortality, and for the exposure category ≥55 h/week for IHD prevalence. Evidence on exposure to working ≥55 h/week was judged as "sufficient evidence of harmfulness" for IHD incidence and mortality. Producing estimates for the burden of IHD attributable to exposure to working ≥55 h/week appears evidence-based, and the pooled effect estimates presented in this systematic review could be used as input data for the WHO/ILO Joint Estimates.