Job strain and autonomic indices of cardiovascular disease risk

Is boredom at work bad for your health? Examining the links between job boredom and autonomic nervous system dysfunction

Job boredom refers to an unpleasant state of passiveness at work that has been found to negatively relate to self-reported health. To date, however, the relation between job boredom and physiological indicators of health has not been examined. The present study investigates whether job boredom relates to dysfunction in autonomic nervous system (ANS) activity as indicated by reduced heart rate variability (HRV) during night sleep. The sample of this study consisted of Finnish public sector workers (n = 125). Job boredom was assessed with an electronic questionnaire and HRV with an ambulatory monitoring period of two nights of sleep. The results supported the hypothesis by showing a negative relation between job boredom and HRV, after controlling for demographic and lifestyle factors. The findings extend previous knowledge on the detrimental consequences of job boredom by showing that it is related to dysfunction in ANS activity. Consequently, it is important to acknowledge boredom at work as a threat to occupational health and well-being and pay more attention to how it can be prevented at workplaces.

Work-related problems and the psychosocial characteristics of individuals with irritable bowel syndrome: an updated literature review

BACKGROUND

Irritable bowel syndrome (IBS) is a common, functional gastrointestinal disorder. Because IBS often develops and worsens with stress, it requires treatment from both physical and mental perspectives. Recent years have seen increasing reports of its impact on the daily performance and productivity of workers with IBS, leading to sick leaves and lower quality of life. Therefore, this narrative review aimed to summarize the work and psychosocial characteristics of individuals with IBS.

MAIN BODY

Workers with IBS report greater occupational stressors and work productivity impairments, including presenteeism or absenteeism, in addition to suffering from psychological distress, low quality of life, and medical and economic problems, similar to those with IBS in the general population. Anxiety about abdominal symptoms, as well as the severity of IBS, is related to the degree of interference with one's work. Regarding the association between characteristics of work and IBS, shift work and job demands/discretion have been associated with IBS. Studies on specific occupations have revealed associations between IBS and various occupational stressors in healthcare workers, firefighters, and military personnel. Telecommuting, which has become increasingly popular during the coronavirus disease pandemic, has not found to improve IBS. Moreover, the effectiveness of medication, diet, and a comprehensive self-management program, including cognitive behavioral therapy, in improving the productivity of workers with IBS have been examined.

CONCLUSION

As mentioned above, the IBS of workers is related not only to their problematic physical and mental health but also to work-related problems; workers with IBS exhibit severe occupational stress factors and work productivity impairment. Further research is required to develop efficient and appropriate interventions for workers.

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.

Home Care Workers' Objective and Subjective Recovery From Work

OBJECTIVE

The aim of this cross-sectional study was to examine the recovery from work in Finnish home care nurses with objective and subjective recovery measures.

METHODS

Heart rate and heart rate variability recordings were performed in home care nurses over a period of one work shift and the following night. Following the measurements, the participants ( N = 91) answered a questionnaire including questions about their self-rated recovery from work and sleep disturbances.

RESULTS

The objectively measured recovery was within the recommended heart rate variability range, yet the self-rated recovery from work was only mediocre. Subjective recovery was not associated with objectively measured recovery.

CONCLUSIONS

There is a discrepancy between objectively and subjectively measured recovery from work. Therefore, an additional objective method in occupational field studies, along with questionnaires, is recommended to measure physiological recovery.

Prevalence of coronary heart disease and its risk factors by working environment among Japanese male workers

Work is a major social determinant of health. We conducted a cross-sectional study to explore the association between coronary heart disease (CHD), its risk factors, and the working environment among Japanese male workers. We collected data from 10,572 workers (mean age 49.9 yr) who underwent annual medical check-ups in Toyama, Japan, in 2016. This study included data from health check-ups and questionnaires on medical history of CHD, hypertension, and diabetes, and the use of medication. The working environment included company size and industry categories. Company size was classified into 4 categories according to the number of full-time workers (1-20, 21-100, 101-300, 301-). The industry category was classified into 10 categories. Logistic regression analysis was performed to explore the association. In total, 1.5% of patients had a history of CHD and 31.5% and 11.0% of participants were suffering from hypertension and diabetes, respectively. Compared to workers in a large company, those in a smaller company were more likely to have CHD. Moreover, there was a significant association between CHD's risk factors and working in the transportation industry. Health providers, including medical doctors, should consider employee working environment as a potential risk factor for CHD.

Increased physical workload in home care service is associated with reduced recovery from work

OBJECTIVE

This study investigated the physical workload of home care service workers and determined whether the different intensities of physical work strain experienced by home care nurses have different impacts on their recovery from work.

METHODS

Physical workload and recovery were measured among 95 home care nurses based on heart rate (HR) and heart rate variability (HRV) recordings during one work shift and the following night. Differences in the physical work strain were compared between younger (≤ 44-year-old) and older (≥ 45-year-old) employees and between morning and evening shifts. To determine the effects of occupational physical activity on recovery, HRV at all time points (during the workday, when awake and asleep, and whole measurement) in relation to the amount of occupational physical activity was examined.

RESULTS

The average physiological strain during the work shift, measured as metabolic equivalent (MET), was 1.8 ± 0.5. Moreover, the occupational physical demands in relation to maximal capacity were higher for the older employees. The results of the study showed that a higher occupational physical workload reduced the HRV of home care workers during the workday, leisure time, and sleep.

CONCLUSIONS

These data indicate that increased occupational physical workload is associated with reduced recovery among home care workers. Therefore, decreasing occupational strain and ensuring sufficient recovery is recommended.

Heart rate variability during sleep after two, four and seven consecutive night shifts and recovery days: a cross-over intervention study

OBJECTIVE

Recovery after shift work is an important part reducing the health problems related to shift work. Heart rate variability (HRV) is an indicator of the balance between sympathetic and parasympathetic activity in the autonomic nervous system and can be used as a measure of recovery after night shifts. The aim of the study is to investigate autonomic recovery during sleep in response to night work in a crossover intervention study.

METHODS

Seventeen male police officers working in call centres in five different police district participated in the HRV measurements. The participants were exposed to three interventions: 2 + 2: two consecutive night shifts followed by two consecutive day recovery days; 4 + 4: four consecutive night shifts followed by four consecutive recovery days; 7 + 7: seven consecutive night shifts followed by seven consecutive recovery days. On the last day with night shift and the last recovery day in each intervention the participants underwent 24 h HRV recordings. We analysed HRV during sleep. The five 5-min intervals with the lowest heart rate during each sleep period were chosen for spectral analysis of the heart interbeat interval time series. The five 5-min intervals could occur at any time during sleep.

RESULTS

There were overall differences in HRV during sleep between days with night shifts and recovery days, primarily in parasympathetic activity. There was no difference in the lowest heart rate obtained, but the timing was different for the three interventions. The lowest heart rate after night shifts occurred 112 (SD 79) min, 174 (SD 115) min and 135 (SD 94) min after sleep onset for the 2 + 2 night shift, the 4 + 4 night shift and the 7 + 7 night shift, respectively.

CONCLUSION

Overall sleep-related autonomic recovery had higher parasympathetic modulation of cardiac rhythm on the 2 + 2 shift system compared to the 4 + 4 and 7 + 7 shift system.

Evaluation of an ergonomically designed schoolbag: Heart rate variability and body discomfort rating

BACKGROUND: Unsuitable schoolbags may stress the spine and promote poor body posture, particularly for school students. Global recommendations have suggested that schoolbag weight must not exceed 10% of a healthy student’s body mass, which would need continuous monitoring and enforcement. OBJECTIVES: The present study presents a comparison between an ergonomically designed schoolbag, which helps reduce the potential effects of carrying a load, and a commercial one. METHODS: A total of 30 healthy male students were recruited for this experiment. Independent variables determined were schoolbag type (ergonomically designed and commercial schoolbags) and three load levels based on body mass percentage (i.e., 10%, 15%, and 20% of body mass). Heart rate variability (HRV) and body discomfort rating were then measured. RESULTS: Our results showed that the developed schoolbag promoted enhanced subjective measures and HRV response at 15% and 20% of body mass. Participants who wore the developed schoolbags experienced significantly lesser neck, shoulder, upper and lower trunk discomfort than those who wore the traditional ones. Changing the load percentage from 10% to 15% caused an increase in heart rate among participants carrying a commercial schoolbag but a decrease in heart rate among those carrying the developed schoolbag. CONCLUSIONS: The findings presented herein suggest introducing strategies for reducing the potential impact of load carrying through the combined effect of new educational inventions and policy changes.

Effects of Changes in Environmental Color Chroma on Heart Rate Variability and Stress by Gender

With increasing time spent indoors during the coronavirus disease pandemic, occupants are increasingly affected by indoor space environmental factors. Environmental color stimulates human vision and affects stress levels. This study investigated how changing environmental color chroma affected heart rate variability (HRV) and stress. The HRV of nine males and fifteen females was measured during exposure to 12 color stimuli with changes in chroma under green/blue hues and high/low-value conditions, and a stress assessment was performed. The effect of chroma on the HRV of males and females was verified, but the interaction effect between chroma and gender was not. ln(LF) and RMSSD were valid parameters. ln(LF) of males and females decreased as chroma increased under the green hue and low-value conditions; RMSSD was reduced as chroma increased in the blue hue and low-value conditions. ln(LF) decreased as chroma increased under blue hue and high-value conditions in males. Color–stress evaluation revealed that the higher chroma under high-value conditions, the more positive the stress emotion, and the lower the chroma under low-value conditions, the more negative the stress emotion. As chroma increased under low-value conditions, color is a stress factor; for men, this effect was more evident in the blue hue.

The Protective Role of Job Control/Autonomy on Mental Strain of Managers: A Cross-Sectional Study among Wittyfit's Users

BACKGROUND

Karasek's Job Demand-Control-Support model is the gold standard to assess the perception of work; however, this model has been poorly studied among managers. We aimed to explore the perception of work (job demand, control, and support) in managers, and to quantify their risk of job strain (high job demand and low job control) and isostrain (job strain with low job support).

METHODS

We conducted a cross-sectional study on workers from various French companies using the Wittyfit software. Job demand, control, and support were evaluated by self-reported questionnaires, as well as sociodemographic data.

RESULTS

We included 9257 workers: 8488 employees (median age of 45 years, median seniority of 10 years, 39.4% women) and 769 managers (463 were more than 45 years old, 343 with more than 10 years of service, 33.3% women). Managers had higher mean ± SD levels than employees in job control (79.2 ± 14.9 vs. 75.4 ± 16.9) and job support (25.2 ± 5.1 vs. 24.0 ± 6.1) (p < 0.001). Compared to employees, managers had a 37% decreased risk of job strain (OR = 0.63, 95% CI 0.52 to 0.77) and a 47% decreased risk of isostrain (OR = 0.53, 95% CI 0.40 to 0.69) (p < 0.001). Workers over age 45 (OR = 1.26, 95% CI 1.14 to 1.40, p < 0.001) and women (OR = 1.12, 95% CI 1.01 to 1. 25, p = 0.03) were at greater risk of job strain. Furthermore, workers over age 45 (OR = 1.51, 95% CI 1.32 to 1.73, p < 0.001), workers with over 10 years of service (OR = 1.35, 95% CI 1.16 to 1.56, p < 0.001), and women (OR = 1.15, 95% CI 1.00 to 1.31, p = 0.04) were at greater risk of isostrain.

CONCLUSIONS

Managers seem to have higher autonomy and greater social support and therefore are less at risk of job strain or isostrain than employees. Other factors such as age, seniority, and sex may influence this relationship.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02596737.

The Impact of a Resident's Sense of Control on Burnout in Orthopaedic Surgery Residency

»

Physician burnout is a barrier to the patient-centered approach to health care.

»

One of the driving factors of resident burnout is the decreased level of control that residents have over their everyday lives.

»

Providing residents with a sense of control over their lives and their jobs increases job satisfaction and leads to a decrease in reports of negative effects on health, rest, participation in extracurricular activities, and time with family.

The association between drought conditions and increased occupational psychosocial stress among U.S. farmers: An occupational cohort study

BACKGROUND

Drought represents a globally relevant natural disaster linked to adverse health. Evidence has shown agricultural communities to be particularly susceptible to drought, but there is a limited understanding of how drought may impact occupational stress in farmers.

METHODS

We used repeated measures data collected in the Musculoskeletal Symptoms among Agricultural Workers Cohort study, including 498 Midwestern U.S. farmers surveyed with a Job Content Questionnaire (JCQ) at six-month intervals in 312 counties from 2012 through 2015. A longitudinal linear mixed effects model was used to estimate the change in job strain ratio, a continuous metric of occupational psychosocial stress, during drought conditions measured with a 12-month standardized precipitation index. We further evaluated associations between drought and psychological job demand and job decision latitude, the job strain components, and applied a stratified analysis to evaluate differences by participant sex, age, and geography.

RESULTS

During the growing season, the job strain ratio increased by 0.031 (95% CI: 0.012, 0.05) during drought conditions, an amount equivalent to a one-half standard deviation change (Cohen's D = 0.5), compared to non-drought conditions. The association between drought and the job strain ratio was driven mostly by increases in the psychological job demand (2.09; 95% CI: 0.94, 3.24). No risk differences were observed by sex, age group, or geographic region.

CONCLUSIONS

Our results suggest a previously unidentified association between drought and increased occupational psychosocial stress among farmers. With North American climate anticipated to become hotter and drier, these findings could provide important health effects data for federal drought early warning systems and mitigation plans.

Effects of a snack on performance and errors during a simulated 16-h night shift: A randomized, crossover-controlled, pilot study

BACKGROUND

Night shift workers might not eat due to their busy schedules during the night shift. However, food may not only satisfy hunger, but also affect performance and errors. The aim of this study was to clarify the effect of a snack on performance and errors during 2-day, 16-h, simulated night shifts.

METHODS

A randomized, repeated-measure, crossover study was performed to investigate subjective and cognitive performance in 15 healthy female adults (mean age, 21.7 years) after they consumed a snack (352 kcal) during a simulated night shift (16:00 to 09:00) from October to November 2018. The participants were kept awake from waking up in the morning to the next day at 09:00. Subjects were tested for performance on the Uchida-Kraepelin test, as well as for subjective feeling, body temperature, psychomotor vigilance test, and heart rate variability, before and after they consumed the snack. One day before the experiment, all participants wore an actigraphy monitoring device to determine their sleep state.

RESULTS

There was no difference between having (Snack condition) and not having (Skipping condition) the snack in sleep states the day before the experiment. On the day of the experiment, between 16:00 and 09:00, subjective sleepiness, fatigue, and body temperature were not different between the two conditions. Subjects maintained performance on the Uchida-Kraepelin test and showed a significant improvement in false starts on the psychomotor vigilance test, the primary outcome measure, in the Snack condition compared with the Skipping condition. The Snack condition was also associated with decreased high-frequency power, a decreased low-frequency power/high-frequency power ratio, and increased heart rate in the vagally mediated heart rate variability indices, which may reflect a higher ability to modulate cognitive and behavioral processes.

CONCLUSIONS

These results suggest that providing a snack to shift workers during night shifts might improve work safety and efficiency.

Effects on Heart Rate Variability of Stress Level Responses to the Properties of Indoor Environmental Colors: A Preliminary Study

Color is the most potent stimulating factor affecting human vision, and the environmental color of an indoor space is a spatial component that affects the environmental stress level. As one of the methods of assessing the physiological response of the autonomic nervous system that influences stress, heart rate variability (HRV) has been utilized as a tool for measuring the user’s stress response in color environments. This study aims to identify the effects of the changes of hue, brightness, and saturation in environmental colors on the HRV of two groups with different stress levels—the stress potential group (n = 15) and the healthy group (n = 12)—based on their stress level indicated by the Psychosocial Well-being Index (PWI). The ln(LF), ln(HF), and RMSSD values collected during the subjects’ exposure to 12 environments colors of red and yellow with adjusted saturation and brightness, were statistically analyzed using t-test and two-way ANOVA. The results show that the HRV values in the two groups did not significantly vary in response to the changes in hue, brightness and saturation. The two groups’ stress factors distinguished according to the stress levels by the PWI scale affected the In(LF) parameter, which demonstrates that the PWI index can be utilized as a reliable scale for measuring stress levels. The ultra-short HRV measurement record and the use of a sole In(LF) parameter for stress assessment are regarded as the limitations of this study.

[Assessment of Psychological Stress in Kindergarten Teachers with Varying Degrees of Overcommitment]

OBJECTIVE

Nursery school teachers are exposed to psycho-emotional stress in their profession, which can lead to health problems. The aim of the study was to examine whether and to what extent increased work commitment (overcommitment, OC) affects the health of educators.

METHODS

163 nursery school teachers (age 44.5 ± 12.4 years) were recruited for the study. OC, mental health and the risk of burnout were assessed using standardized questionnaires. ECG recordings over 24 h served as a basis for the calculation of heart rate variability (HRV).

RESULTS

121 teachers showed normal OC and 42 teachers increased OC. In nursery school teachers with elevated OC, self-reported mental health is impaired and vagal mediated HRV (RMSSD and HF) is reduced.

CONCLUSION

Since the subjectively assessed mental health of nursery school teachers with elevated OC deteriorates and HRV is reduced, preventive measures must be taken to maintain the health of nursery school teachers.

Effects of participatory workplace improvement program on stress-related biomarkers and self-reported stress among university hospital nurses: a preliminary study

Although participatory workplace improvement programs are known to provide favorable effects on high stress occupations like nursing, no studies have confirmed its effect using biomarkers. The aim of this study was to determine whether a participatory workplace improvement program would decrease stress-related symptoms as evaluated by biomarkers and self-reported stress among hospital nurses. Three actions to alleviate job stress, which were determined through focus group interviews and voting, were undertaken for two months. A total of 31 female Japanese nurses underwent measurement of inflammatory markers, autonomic nervous activity (ANA), and perceived job stress (PJS) at three-time points; before the program (T1), within a week after the completion of the program (T2), and three months after the program (T3). A series of inflammatory markers (Interferon-γ, Interleukin (IL)-6, and IL-12/23p40) decreased significantly at T2, and IL-12/23p40 and IL-15 significantly decreased at T3 compared to T1, while ANA and PJS remained unchanged. Our participatory program exerted beneficial effects in reducing inflammatory responses, but not for ANA and PJS. Further investigations with a better study design, i.e., a randomized controlled trial, and a larger sample size are warranted to determine what exerted beneficial effects on inflammatory markers and why other outcomes remained unchanged.

Exploring the Link between Work Addiction Risk and Health-Related Outcomes Using Job-Demand-Control Model

Purpose of the study: Work addiction risk is a growing public health concern with potential deleterious health-related outcomes. Perception of work (job demands and job control) may play a major role in provoking the risk of work addiction in employees. We aimed to explore the link between work addiction risk and health-related outcomes using the framework of job-demand-control model. Methods: Data were collected from 187 out of 1580 (11.8%) French workers who agreed to participate in a cross-sectional study using the WittyFit software online platform. The self-administered questionnaires were the Job Content Questionnaire by Karasek, the Work Addiction Risk Test, the Hospital Anxiety and Depression scale and socio-demographics. Data Analysis: Statistical analyses were performed using the Stata software (version 13). Results: There were five times more workers with a high risk of work addiction among those with strong job demands than in those with low job demands (29.8% vs. 6.8%, p = 0.002). Addiction to work was not linked to job control (p = 0.77), nor with social support (p = 0.22). We demonstrated a high risk of work addiction in 2.6% of low-strain workers, in 15.0% of passive workers, in 28.9% of active workers, and in 33.3% of high-strain workers (p = 0.010). There were twice as many workers with a HAD-Depression score ≥11 compared with workers at low risk (41.5% vs. 17.7%, p = 0.009). Sleep quality was lower in workers with a high risk of work addiction compared with workers with a low risk of work addiction (44.0 ± 27.3 vs. 64.4 ± 26.8, p < 0.001). Workers with a high risk of work addiction exhibited greater stress at work (68.4 ± 23.2 vs. 47.5 ± 25.1) and lower well-being (69.7 ± 18.3 vs. 49.3 ± 23.0) compared with workers at low risk (p < 0.001). Conclusions: High job demands are strongly associated with the risk of work addiction. Work addiction risk is associated with greater depression and poor quality of sleep. Preventive strategies should benefit from identifying more vulnerable workers to work addiction risk.

Job Stress and Heart Rate Variability: Findings From the ELSA-Brasil Cohort

OBJECTIVE

Evidence suggests that exposure to psychosocial stress at work can inhibit vagal tonus, influencing the capacity to respond to environmental stimuli. We investigated whether job strain and low control and high demand at work, as separate measures, are associated with a reduction in heart rate variability (HRV).

METHODS

This is a cross-sectional study with 9658 active workers at the baseline (2008-2010) of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). HRV was estimated using electrocardiographic recordings for 10 minutes, at rest, examining the following indices were used: root mean square of successive difference, standard deviation of normal to normal, percentage of adjacent R-R intervals with a difference lasting more than 50 ms, low frequency (LF), and high frequency. Job strain was defined based on the demand-control model. Independent associations between job strain and HRV indices were verified using generalized linear models and the magnitude of the association was estimated by evaluating the ratios of arithmetic means.

RESULTS

Neither the unfavorable demand-control relation nor job demand dimension separately was associated with HRV. However, the increase of one unit in the control dimension was associated with an increment of 2.2% (95% confidence interval = 1.014-1.029) in the LF mean. After adjustments for sociodemographic characteristics, assessment site, health-related behaviors, and depression, this association remained statistically significant (ratio of arithmetic means = 1.008; 95% confidence interval = 1.0002-1.017).

CONCLUSIONS

Job control was associated with HRV in a large cohort of civil servants. Nevertheless, it is important to emphasize that only the LF index remained associated with low job control. Further studies are needed to develop a greater understanding of the relationship of psychosocial aspects and autonomic balance.

Ambulatory Assessment of Psychological and Physiological Stress on Workdays and Free Days Among Teachers. A Preliminary Study

Objective

Teachers are affected by high levels of job stress, leading to one of the highest rates of burnout. The purpose of our pilot study was to investigate the diurnal course of teachers’ psychological and physiological stress responses [cortisol levels, alpha-amylase, heart rate (HR), and heart rate variability (HRV)]. Another aim of the project was to test the applicability of ambulatory assessment methods in daily teaching situations.

Methods

In a non-clinical sample of eight primary school teachers (mean age = 43, SD = 15.22, 6 females) in Switzerland, continuous biopsychological data on two workdays and a free day were assessed. The teachers’ HRs and HRV were measured continuously using an ambulatory ECG. Additionally, eight saliva samples were collected from the teachers repeatedly throughout the day to determine the diurnal course of salivary cortisol and alpha-amylase (sAA). Perceived stress and anger ratings were assessed simultaneously.

Results

As hypothesized, the teachers’ morning cortisol levels, perceived stress, and anger levels were significantly higher, and their overall HRV was significantly lower on workdays than on a free day. Conversely, sAA levels and HRs showed no significant differences between working and free days. Salivary markers exhibited the expected diurnal course, with decreasing cortisol and increasing sAA levels over the course of the day, while self-rated stress reached the maximum at midday during working days.

Conclusion

The results of the present explorative study show that physiological and psychological parameters differ within working and free days for teachers. A comparison between working and free days resulted in differences in morning cortisol levels, HRV as well as stress and anger levels. The ambulatory assessment method was found to be applicable in daily teaching situations.

Association between Work-Related Stress and QT Prolongation in Male Workers

Background: Work-related stress is a potential cardiovascular risk factor, but the underlying mechanism is not fully explained. The autonomic nervous system control of cardiac function might play a specific role; therefore, monitoring the QT interval in the electrocardiogram can highlight an autonomic imbalance induced by occupational stressors. The aim of our study was to explore the QT interval parameters as early indicators of imbalance of the autonomic cardiac function in relation to work-related stress. Methods: During 2015–2016 annual workplace health surveillance, we measured work-related stress in 484 workers of a logistic support company using the Health and Safety Executive (HSE) tool. We assessed the frequency-corrected QT (QTc) interval and the QT index (QTi) on the electrocardiogram of each participant, and collected demographic and clinical data. We compared the QTc values by the four Karasek’s categories (active/passive jobs, low/high strain job), and by job support (present/lacking), and conducted multivariate analysis to adjust for possible confounders. Results: The results of the multivariate regression analysis showed that QTc was prolonged among workers operating at a specific site where stress level was found to be elevated. Regular physical activity showed a beneficial effect against QTc prolongation. We did not observe an effect on QTc length by the cross-combined Karasek’s categories of job control, job demand, and job support. Conclusions: Our study suggests subclinical effects of conditions associated with work-related stress on the autonomic regulation of cardiac function. Further research is warranted to elucidate the combined effect of work organization and lifestyle factors on autonomic cardiac function.

Relationships Among Self-Reported Hearing Problems, Psychological Distress, and Cardiovascular Disease in U.S. Adults, National Health Interview Survey 1997-2017

Objective The purpose of this study was to explore the hypothesis that the relationship between hearing problems and cardiovascular disease (CVD) includes a connection to psychological distress. Design We used generalized structural equation modeling to assess relationships between self-reported measures of hearing problems, psychological distress, and CVD in a pooled sample of 623,416 adult respondents in the 1997-2017 National Health Interview Survey. Hearing status without hearing aids was self-reported on an ordinal scale and further grouped for this study into 3 categories (excellent or good hearing, little or moderate trouble hearing, and a lot of trouble or deaf). Six CVDs (stroke, angina pectoris, hypertension, heart attack, coronary heart disease, or other heart condition/disease) were incorporated as a latent variable. Psychological distress was evaluated by the Kessler 6 Scale (Kessler et al., 2010). All estimates were population weighted, and standard errors were adjusted for a complex survey design. Results Nearly 83% reported excellent or good hearing, 14% reported a little or moderate trouble hearing, and 3% reported a lot of trouble hearing or said they were deaf. Hearing problems were positively associated with CVD. Relative to those reporting excellent/good hearing, adults reporting trouble hearing had a higher probability of CVD. Hearing problems were also significantly associated with psychological distress. When psychological distress was applied to the model, positive associations between hearing problems and CVD were attenuated but still significant. Results are consistent with the hypothesis that the connection between self-reported hearing problems and CVD is mediated through psychological distress. Conclusions The relationship between self-reported hearing problems and CVD is mediated by psychological distress. Further research is needed to identify causal pathways and psychophysiological mechanisms involved in this relationship and to identify effective methods for addressing cardiovascular health-related psychosocial factors in the treatment of hearing impairment.

Falk T. Multi-Scale Heart Beat Entropy Measures for Mental Workload Assessment of Ambulant Users

Mental workload assessment is crucial in many real life applications which require constant attention and where imbalance of mental workload resources may cause safety hazards. As such, mental workload and its relationship with heart rate variability (HRV) have been well studied in the literature. However, the majority of the developed models have assumed individuals are not ambulant, thus bypassing the issue of movement-related electrocardiography (ECG) artifacts and changing heart beat dynamics due to physical activity. In this work, multi-scale features for mental workload assessment of ambulatory users is explored. ECG data was sampled from users while they performed different types and levels of physical activity while performing the multi-attribute test battery (MATB-II) task at varying difficulty levels. Proposed features are shown to outperform benchmark ones and further exhibit complementarity when used in combination. Indeed, results show gains over the benchmark HRV measures of 24.41% in accuracy and of 27.97% in F1 score can be achieved even at high activity levels.

Mental Workload Alters Heart Rate Variability, Lowering Non-linear Dynamics

Mental workload is known to alter cardiovascular function leading to increased cardiovascular risk. Nevertheless, there is no clear autonomic nervous system unbalance to be quantified during mental stress. We aimed to characterize the mental workload impact on the cardiovascular function with a focus on heart rate variability (HRV) non-linear indexes. A 1-h computerized switching task (letter recognition) was performed by 24 subjects while monitoring their performance (accuracy, response time), electrocardiogram and blood pressure waveform (finger volume clamp method). The HRV was evaluated from the beat-to-beat RR intervals (RRI) in time-, frequency-, and informational- domains, before (Control) and during the task. The task induced a significant mental workload (visual analog scale of fatigue from 27 ± 26 to 50 ± 31 mm, p < 0.001, and NASA-TLX score of 56 ± 17). The heart rate, blood pressure and baroreflex function were unchanged, whereas most of the HRV parameters markedly decreased. The maximum decrease occurred during the first 15 min of the task (P1), before starting to return to the baseline values reached at the end of the task (P4). The RRI dimension correlation (D2) decrease was the most significant (P1 vs. Control: 1.42 ± 0.85 vs. 2.21 ± 0.8, p < 0.001) and only D2 lasted until the task ended (P4 vs. Control: 1.96 ± 0.9 vs. 2.21 ± 0.9, p < 0.05). D2 was identified as the most robust cardiovascular variable impacted by the mental workload as determined by posterior predictive simulations (p = 0.9). The Spearman correlation matrix highlighted that D2 could be a marker of the generated frustration (R = -0.61, p < 0.01) induced by a mental task, as well as the myocardial oxygen consumption changes assessed by the double product (R = -0.53, p < 0.05). In conclusion, we showed that mental workload sharply lowered the non-linear RRI dynamics, particularly the RRI correlation dimension.

Stress and neurocognitive efficiency in managerial contexts

Purpose

The purpose of this paper is to test the potential of an innovative technology-mediated mental training protocol for the empowerment of stress management and neurocognitive efficiency in highly stressful professional contexts, with people who occupy top management positions. The innovative protocol specifically combines mindfulness practice and a wearable neurofeedback system managed via smartphone.

Design/methodology/approach

The longitudinal research included pre- and post-training assessment steps in order to test training effects with respect to subjective level and physiological markers of stress, anxiety and mood profiles, cognitive abilities and markers of neurocognitive efficiency.

Findings

Results showed decreased stress, anxiety, anger and mental fatigue; increased participants’ information-processing efficiency; increased electrophysiological markers concerning the balance and reactivity of the mind-brain system; and improved physiological markers of vagal tone.

Research limitations/implications

Though further investigation and replication with larger samples would strengthen present findings, the authors suggest that observed outcomes, together with the limited duration of the overall protocol and of daily practices, make the training a potentially valuable tool especially for people whose professional position imposes time limitations and elevated job duties, thus increasing the risk of drop-out from traditional stress management programs.

Originality/value

The combination of mindfulness-based mental training with the advantages offered by a novel brain-sensing wearable technology allows for overcoming the weak points of traditional approaches (e.g. notable time expense) and optimizing training opportunities and outcomes. Furthermore, this is, to the authors’ best knowledge, the first systematic report of the application of such methodology in an organization and with top management professionals.

Hearing laughter improves the recovery process of the autonomic nervous system after a stress-loading task: a randomized controlled trial

Background

It has become necessary to develop mental health management methods that do not require specialized skills or tools to implement. With this in mind, we performed a subjective and objective investigation of the stress-reducing effect of hearing laughter.

Methods

Ninety healthy students were randomly assigned to a laughter (n = 45) or rest (n = 45) group. Both groups were then administered the Uchida-Kraepelin test for 15 min, which served as a stress-loading method. The laughter group listened to a specially prepared CD for five minutes, while the rest group rested for five minutes. The participants’ subjective stress level was assessed using a visual analogue scale and their physiological status was assessed by measuring blood pressure and monitoring heart rate variability.

Results

The visual analogue scale score for subjective stress was found to decrease significantly in both the laughter and rest groups after the intervention. However, a two-way repeated-measures analysis of variance revealed significant interaction and main effects for the change in heart rate and the natural logarithm of the high-frequency component of heart rate variability (lnHF). A post-hoc analysis using Dunnett’s test showed that hearing laughter caused the lnHF to significantly increase compared to that recorded during the Uchida-Kraepelin test and the rest period.

Conclusions

These results suggest that hearing laughter might produce a relaxing effect by increasing parasympathetic nervous activity. This would make it an easily accessible method for improving the recovery process of the autonomic nervous system after a stress-loading task that does not require specialized skills or tools.

Trial registration

UMIN000016422. Retrospectively registered on 2 February 2015.

Electronic supplementary material

The online version of this article (10.1186/s13030-018-0141-0) contains supplementary material, which is available to authorized users.

Executive Stress Management: Physiological Load of Stress and Recovery in Executives on Workdays

Objective: The use of high-performance sports technology to describe the physiological load of stress and the quality of recovery in a population of executives during the workday. Methodology: Heart rate variability values were recorded during 48 h from which the relationship between stress/recovery quality (stress balance) was obtained for three differentiated time slots: work, after work, and night in a workday. Results: We observed a negative stress balance during the 24 h of measurement in the course of a workday, being negative at work and after work, and positive at night. The stress generated or maintained outside working hours correlates significantly with a lower quality of recovery during the 24 h workday. Conclusions: It is necessary to prioritize strategies that help improve stress management in executives through the improvement of tools and strategies that mainly promote greater relaxation outside working hours.

Do cognitive appraisals moderate the link between qualitative job insecurity and psychological-behavioral well-being?

Purpose

The purpose of this paper is to detect the association between qualitative job insecurity and well-being related outcomes and to determine the extent to which cognitive appraisals of job insecurity moderate this association. According to appraisal theory, it is anticipated a hindrance appraisal of job insecurity to amplify and a challenge appraisal of job insecurity to buffer this association.

Design/methodology/approach

To test the hypotheses, 250 healthcare employees from different departments of an Iranian large public hospital were recruited. Participants responded to scales on qualitative job insecurity, cognitive appraisals, job satisfaction, emotional exhaustion, absenteeism and presenteeism.

Findings

Results showed that qualitative job insecurity negatively influenced both psychological and behavioral well-being; however, this influence was greater for psychological well-being than for behavioral well-being. Besides, the moderation tests showed that only the hindrance appraisals of job insecurity amplified the link between job insecurity and psychological outcomes.

Research limitations/implications

This study sampled employees from a public hospital and did not include employees from private hospitals. This may limit the generalizability of the findings. Also, due to using a cross-sectional research design we encourage future studies to replicate the same findings using other different research designs.

Practical implications

The findings aid occupational health psychologists to design particular interventions for protecting those aspects of employee’s well-being that are more vulnerable when qualitative job insecurity is chronically perceived.

Originality/value

Together, these findings suggest that the hindrance appraisals of qualitative job insecurity are more likely to moderate the link between job insecurity and well-being outcomes.

Heart rate variability and occupational stress-systematic review

The aim of this systematic review was to explore studies regarding association between occupational stress and heart rate variability (HRV) during work. We searched PubMed, Web of Science, Scopus, Cinahl and PsycINFO for peer-reviewed articles published in English between January 2005 and September 2017. A total of 10 articles met the inclusion criteria. The included articles were analyzed in terms of study design, study population, assessment of occupational stress and HRV, and the study limitations. Among the studies there were cross-sectional (n=9) studies and one longitudinal study design. Sample size varied from 19 to 653 participants and both females and males were included. The most common assessment methods of occupational stress were the Job Content Questionnaire (JCQ) and the Effort-Reward Imbalance (ERI) questionnaire. HRV was assessed using 24 h or longer Holter ECG or HR monitoring and analyzed mostly using standard time-domain and frequency-domain parameters. The main finding was that heightened occupational stress was found associated with lowered HRV, specifically with reduced parasympathetic activation. Reduced parasympathetic activation was seen as decreases in RMSSD and HF power, and increase in LF/HF ratio. The assessment and analysis methods of occupational stress and HRV were diverse.

Associations of sympathetic and parasympathetic activity in job stress and burnout: A systematic review

This systematic review examines the relationship between sympathetic and parasympathetic activity on the one hand and job stress and burnout on the other, and is registered at PROSPERO under CRD42016035918. Background: Previous research has shown that prolonged job stress may lead to burnout, and that differences in heart rate variability are apparent in people who have heightened job stress. Aims: In this systematic review, the associations between job stress or burnout and heart rate (variability) or skin conductance are studied. Besides, it was investigated which–if any–guidelines are available for ambulatory assessment and reporting of the results. Methods: We extracted data from relevant databases following the PRESS checklist and contacted authors for additional resources. Participants included the employed adult population comparing validated job stress and burnout questionnaires examining heart rate and electrodermal activity. Synthesis followed the PRISMA guidelines of reporting systematic reviews. Results: The results showed a positive association between job stress and heart rate, and a negative association between job stress and heart rate variability measures. No definite conclusion could be drawn with regard to burnout and psychophysiological measures. No studies on electrodermal activity could be included based on the inclusion criteria. Conclusions: High levels of job stress are associated with an increased heart rate, and decreased heart rate variability measures. Recommendations for ambulatory assessment and reporting (STROBE) are discussed in light of the findings.

Effects of Cold Stimulation on Cardiac-Vagal Activation in Healthy Participants: Randomized Controlled Trial

Background

The experience of psychological stress has not yet been adequately tackled with digital technology by catering to healthy individuals who wish to reduce their acute stress levels. For the design of digitally mediated solutions, physiological mechanisms need to be investigated that have the potential to induce relaxation with the help of technology. Research has shown that physiological mechanisms embodied in the face and neck regions are effective for diminishing stress-related symptoms. Our study expands on these areas with the design for a wearable in mind. As this study charts new territory in research, it also is a first evaluation of the viability for a wearables concept to reduce stress.

Objective

The objectives of this study were to assess whether (1) heart rate variability would increase and (2) heart rate would decrease during cold stimulation using a thermode device compared with a (nonstimulated) control condition. We expected effects in particular in the neck and cheek regions and less in the forearm area.

Methods

The study was a fully randomized, within-participant design. Volunteer participants were seated in a laboratory chair and tested with cold stimulation on the right side of the body. A thermode was placed on the neck, cheek, and forearm. We recorded and subsequently analyzed participants’ electrocardiogram. The cold stimulation was applied in 16-second intervals over 4 trials per testing location. The control condition proceeded exactly like the cold condition, except we manipulated the temperature variable to remain at the baseline temperature. We measured heart rate as interbeat intervals in milliseconds and analyzed root mean square of successive differences to index heart rate variability. We analyzed data using a repeated-measures ANOVA (analysis of variance) approach with 2 repeated-measures factors: body location (neck, cheek, forearm) and condition (cold, control).

Results

Data analysis of 61 participants (after exclusion of outliers) showed a main effect and an interaction effect for body location and for condition, for both heart rate and heart rate variability. The results demonstrate a pattern of cardiovascular reactivity to cold stimulation, suggesting an increase in cardiac-vagal activation. The effect was significant for cold stimulation in the lateral neck area.

Conclusions

The results confirmed our main hypothesis that cold stimulation at the lateral neck region would result in higher heart rate variability and lower heart rate than in the control condition. This sets the stage for further investigations of stress reduction potential in the neck region by developing a wearable prototype that can be used for cold application. Future studies should include a stress condition, test for a range of temperatures and durations, and collect self-report data on perceived stress levels to advance findings.

Generalized Unsafety Theory of Stress: Unsafe Environments and Conditions, and the Default Stress Response

Prolonged physiological stress responses form an important risk factor for disease. According to neurobiological and evolution-theoretical insights the stress response is a default response that is always "on" but inhibited by the prefrontal cortex when safety is perceived. Based on these insights the Generalized Unsafety Theory of Stress (GUTS) states that prolonged stress responses are due to generalized and largely unconsciously perceived unsafety rather than stressors. This novel perspective necessitates a reconstruction of current stress theory, which we address in this paper. We discuss a variety of very common situations without stressors but with prolonged stress responses, that are not, or not likely to be caused by stressors, including loneliness, low social status, adult life after prenatal or early life adversity, lack of a natural environment, and less fit bodily states such as obesity or fatigue. We argue that in these situations the default stress response may be chronically disinhibited due to unconsciously perceived generalized unsafety. Also, in chronic stress situations such as work stress, the prolonged stress response may be mainly caused by perceived unsafety in stressor-free contexts. Thus, GUTS identifies and explains far more stress-related physiological activity that is responsible for disease and mortality than current stress theories.

Heart Rate Variability Frequency Domain Alterations among Healthy Nurses Exposed to Prolonged Work Stress

The deregulation of the autonomic nervous system assessed through the heart rate variability (HRV) analysis is a promising pathway linking work stress and cardiovascular diseases. We aim to investigate the associations between HRV High Frequency (HF) and Low Frequency (LF) powers and work stress in a sample of 36 healthy nurses. Perceived work stress was assessed twice one year apart, using the Job Content and Effort Reward Imbalance questionnaires. This allows to classify nurses in three exposure groups: “prolonged high stress” (PHS), “recent high stress” (RHS) and “stable low stress” (SLS). A 24-h ECG monitoring was later performed during a working day (WD) and a subsequent resting day (RD). Statistically significantly lower (p < 0.02) HF and LF means were found in PHS and RHS nurses during the working periods. In the subsequent resting periods, HF means showed increases over time in the RHS (beta = +0.41, p < 0.05), but not in PHS nurses. LF means did not show any substantial increases in the resting periods, in the PHS group with geometric means lower when compared to SLS, in the non-working and resting periods. Our study evidences that both prolonged and recent perceived high work stress were associated with a reduction of HF and LF powers during work. In addition, prolonged stress was associated with a lack of recovery during not-working and resting periods.

Work, organisational practices, and margin of manoeuver during work reintegration

BACKGROUND

Many individuals of working age experience cardiovascular disease and are disabled from work as a result. The majority of research in cardiac work disability has focused on individual biological and psychological factors influencing work disability despite evidence of the importance of social context in work disability. In this article, the focus is on work and organisational features influencing the leeway (margin of manoeuvre) workers are afforded during work reintegration.

METHODS

A qualitative method was used. A large auto manufacturing plant was selected owing to work, organisational, and worker characteristics. Workplace context was assessed through site visits and meetings with stakeholders including occupational health, human resources and union personnel and a review of collective agreement provisions relating to seniority, benefits and accommodation. Worker experience was assessed using a series of in-depth interviews with workers (n = 12) returning to work at the plant following disabling cardiac illness. Data was analysed using qualitative content analysis.

RESULTS

Workers demonstrated variable levels of adjustment to the workplace that could be related to production expectations and work design. Policies and practices around electronic rate monitoring, seniority and accommodation, and disability management practices affected the buffer available to workers to adjust to the workplace.

CONCLUSIONS

Work qualities and organisational resources establish a margin of manoeuver for work reintegration efforts. Practitioners need to inform themselves of the constraints on work accommodation imposed by work organisation and collective agreements. Organisations and labour need to reconsider policies and practices that creates unequal accommodation conditions for disabled workers. Implications for rehabilitation Margin of manoeuvre offers a framework for evaluating and structuring work reintegration programmes. Assessing initial conditions for productivity expectations, context and ways and means to support work reintegration can be integrated with worker perceptions of work ability and possibilities for adaptation to structure and then monitor work reintegration programmes. Margin of manoeuvre can be used to evaluate sustainability of work at the end of rehabilitation. Cause-based workers' compensation schemes, collective agreement provisions, and organisational approaches to non-compensable disability create two tiers of disabled workers and make certain workers more vulnerable to occupational disability.

WittyFit-Live Your Work Differently: Study Protocol for a Workplace-Delivered Health Promotion

BACKGROUND

Morbidity before retirement has a huge cost, burdening both public health and workplace finances. Multiple factors increase morbidity such as stress at work, sedentary behavior or low physical activity, and poor nutrition practices. Nowadays, the digital world offers infinite opportunities to interact with workers. The WittyFit software was designed to understand holistic issues of workers by promoting individualized behavior changes at the workplace.

OBJECTIVE

The shorter term feasibility objective is to demonstrate that effective use of WittyFit will increase well-being and improve health-related behaviors. The mid-term objective is to demonstrate that WittyFit improves economic data of the companies such as productivity and benefits. The ultimate objective is to increase life expectancy of workers.

METHODS

This is an exploratory interventional cohort study in an ecological situation. Three groups of participants will be purposefully sampled: employees, middle managers, and executive managers. Four levels of engagement are planned for employees: commencing with baseline health profiling from validated questionnaires; individualized feedback based on evidence-based medicine; support for behavioral change; and formal evaluation of changes in knowledge, practices, and health outcomes over time. Middle managers will also receive anonymous feedback on problems encountered by employees, and executive top managers will have indicators by division, location, department, age, seniority, gender and occupational position. Managers will be able to introduce specific initiatives in the workplace. WittyFit is based on two databases: behavioral data (WittyFit) and medical data (WittyFit Research). Statistical analyses will incorporate morbidity and well-being data. When a worker leaves a workplace, the company documents one of three major explanations: retirement, relocation to another company, or premature death. Therefore, WittyFit will have the ability to include mortality as an outcome. WittyFit will evolve with the waves of connected objects further increasing its data accuracy. Ethical approval was obtained from the ethics committee of the University Hospital of Clermont-Ferrand, France.

RESULTS

WittyFit recruitment and enrollment started in January 2016. First publications are expected to be available at the beginning of 2017.

CONCLUSIONS

The name WittyFit came from Witty and Fitness. The concept of WittyFit reflects the concept of health from the World Health Organization: being spiritually and physically healthy. WittyFit is a health-monitoring, health-promoting tool that may improve the health of workers and health of companies. WittyFit will evolve with the waves of connected objects further increasing its data accuracy with objective measures. WittyFit may constitute a powerful epidemiological database. Finally, the WittyFit concept may extend healthy living into the general population.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02596737; https://www.clinicaltrials.gov/ct2/show/NCT02596737 (Archived by WebCite at http://www.webcitation.org/6pM5toQ7Y).

Police work stressors and cardiac vagal control

OBJECTIVES

This study examines relationships between the frequency and intensity of police work stressors and cardiac vagal control, estimated using the high frequency component of heart rate variability (HRV).

METHODS

This is a cross-sectional study of 360 officers from the Buffalo New York Police Department. Police stress was measured using the Spielberger police stress survey, which includes exposure indices created as the product of the self-evaluation of how stressful certain events were and the self-reported frequency with which they occurred. Vagal control was estimated using the high frequency component of resting HRV calculated in units of milliseconds squared and reported in natural log scale. Associations between police work stressors and vagal control were examined using linear regression for significance testing and analysis of covariance for descriptive purposes, stratified by gender, and adjusted for age and race/ethnicity.

RESULTS

There were no significant associations between police work stressor exposure indices and vagal control among men. Among women, the inverse associations between the lack of support stressor exposure and vagal control were statistically significant in adjusted models for indices of exposure over the past year (lowest stressor quartile: M = 5.57, 95% CI 5.07 to 6.08, and highest stressor quartile: M = 5.02, 95% CI 4.54 to 5.51, test of association from continuous linear regression of vagal control on lack of support stressor β = -0.273, P = .04).

CONCLUSIONS

This study supports an inverse association between lack of organizational support and vagal control among female but not male police officers.

Improving Managers' Psychophysical Well-Being: Effectiveness of Respiratory Sinus Arrhythmia Biofeedback

High work stress has been consistently associated with disturbed autonomic balance, specifically, lowered vagal cardiac control and increased sympathetic activity, which may lead to increased cardiovascular risk. Stress management procedures have been proposed to reduce autonomic dysfunctions related to work stress in different categories of workers exposed to heightened work demands, while a limited number of studies addressed this issue in managers. The present study was aimed at evaluating the effectiveness of a respiratory sinus arrhythmia (RSA) biofeedback (BF) intervention on psychological and physiological outcomes, in managers with high-level work responsibilities. Thirty-one managers leading outstanding private or public companies were randomly assigned to either a RSA-BF training (RSA-BF; N = 16) or a control group (N = 15). The RSA-BF training consisted of five weekly 45 min sessions, designed to increase RSA, whereas controls had to provide a daily stress diary once a week. After the training, managers in both groups reported reduced heart rate at rest, lower anxiety levels and improvement in health-related quality of life. More importantly, managers in the RSA-BF group showed increased vagal control (as indexed by increased RSA), decreased sympathetic arousal (as indexed by reduced skin conductance and systolic blood pressure) and lower emotional interferences, compared to managers in the control group. Results from this study showed that RSA-BF training was effective in improving cardiac autonomic balance at rest. Moreover, findings from this study underline the effectiveness of biofeedback in reducing psychophysiological negative outcomes associated with stress in managers.

Prolonged job strain reduces time-domain heart rate variability on both working and resting days among cardiovascular-susceptible nurses

INTRODUCTION

Modifications of hearth rate variability (HRV) constitute a marker of the autonomic nervous system (ANS) deregulation, a promising pathway linking job strain (JS) and cardiovascular diseases (CVD). The study objective is to assess whether exposures to recent and prolonged JS reduce time-domain HRV parameters on working days (WD) among CVD-susceptible nurses and whether the association also persists on resting days (RD).

MATERIAL AND METHODS

313 healthy nurses were investigated twice with one year interval to assess JS based on the demand-control and the effort-reward models. 36, 9 and 16 CVD-susceptible nurses were classified as low JS in both surveys (stable low strain - SLS), recent high JS (high JS at the second screening only-RHS) and prolonged high JS (high strain in both surveys-PHS), respectively. In 9, 7 and 10 of them, free from comorbidities/treatments interfering with HRV, two 24-h ECG recordings were performed on WD and RD. Differences in the time domain HRV metrics among JS categories were assessed using ANCOVA, adjusted for age and smoking.

RESULTS

In the entire sample (mean age: 39 years, 83% females) the prevalence of high job strain was 38.7% in the second survey. SDNN (standard deviation of all normal RR intervals) on WD significantly declined among JS categories (p = 0.02), with geometric mean values of 169.1, 145.3 and 128.9 ms in SLS, RHS, PHS, respectively. In the PHS group, SDNN remained lower on RD as compared to the low strain subjects (142.4 vs. 171.1 ms, p = 0.02). Similar findings were found for the SDNN_Index, while SDANN (standard deviation of average RR intervals in all 5 min segments of registration) mean values reduced in the PHS group during WD only.

CONCLUSIONS

Our findings suggest that persistent JS lowers HRV time-domain parameters, supporting the hypothesis that the ANS disorders may play an intermediate role in the relationship between work stress and CVD.

Meta-Analysis of Cardiac Mortality in Three Cohorts of Carbon Black Production Workers

Epidemiological studies have demonstrated associations between airborne environmental particle exposure and cardiac disease and mortality; however, few have examined such effects from poorly soluble particles of low toxicity such as manufactured carbon black (CB) particles in the work place. We combined standardised mortality ratio (SMR) and Cox proportional hazards results from cohort studies of US, UK and German CB production workers. Under a common protocol, we analysed mortality from all causes, heart disease (HD), ischemic heart disease (IHD) and acute myocardial infarction (AMI). Fixed and random effects (RE) meta-regression models were fit for employment duration, and for overall cumulative and lugged quantitative CB exposure estimates. Full cohort meta-SMRs (RE) were 1.01 (95% confidence interval (CI) 0.79–1.29) for HD; 1.02 (95% CI 0.80–1.30) for IHD, and 1.08 (95% CI 0.74–1.59) for AMI mortality. For all three outcomes, meta-SMRs were heterogeneous, increased with time since first and time since last exposure, and peaked after 25–29 or 10–14 years, respectively. Meta-Cox coefficients showed no association with lugged duration of exposure. A small but imprecise increased AMI mortality risk was suggested for cumulative exposure (RE-hazards ratio (HR) = 1.10 per 100 mg/m³-years; 95% CI 0.92–1.31), but not for lugged exposures. Our results do not demonstrate that airborne CB exposure increases all-cause or cardiac disease mortality.

Subjective stress, objective heart rate variability-based stress, and recovery on workdays among overweight and psychologically distressed individuals: a cross-sectional study

BACKGROUND

The present study aimed to investigate how subjective self-reported stress is associated with objective heart rate variability (HRV)-based stress and recovery on workdays. Another aim was to investigate how physical activity (PA), body composition, and age are associated with subjective stress, objective stress, and recovery.

METHODS

Working-age participants (n = 221; 185 women, 36 men) in this cross-sectional study were overweight (body mass index, 25.3-40.1 kg/m(2)) and psychologically distressed (≥3/12 points on the General Health Questionnaire). Objective stress and recovery were based on HRV recordings over 1-3 workdays. Subjective stress was assessed by the Perceived Stress Scale. PA level was determined by questionnaire, and body fat percentage was assessed by bioelectrical impedance analysis.

RESULTS

Subjective stress was directly associated with objective stress (P = 0.047) and inversely with objective recovery (P = 0.046). These associations persisted after adjustments for sex, age, PA, and body fat percentage. Higher PA was associated with lower subjective stress (P = 0.037). Older age was associated with higher objective stress (P < 0.001). After further adjustment for alcohol consumption and regular medication, older age was associated with lower subjective stress (P = 0.043).

CONCLUSIONS

The present results suggest that subjective self-reported stress is associated with objective physiological stress, but they are also apparently affected by different factors. However, some of the found associations among these overweight and psychologically distressed participants with low inter-individual variation in PA are rather weak and the clinical value of the present findings should be studied further among participants with greater heterogeneity of stress, PA and body composition. However, these findings suggest that objective stress assessment provides an additional aspect to stress evaluation. Furthermore, the results provide valuable information for developing stress assessment methods.

The effect of the number of consecutive night shifts on diurnal rhythms in cortisol, melatonin and heart rate variability (HRV): a systematic review of field studies

PURPOSE

The purpose of this review is to summarize the current knowledge from field studies on how many consecutive night shifts are required for adaptation of diurnal rhythms in cortisol, melatonin and heart rate variability (HRV) to night work.

METHODS

A systematic search of the databases PubMed and Web of Science resulted in 18 studies selected for review.

RESULTS

Cortisol was measured in five studies, melatonin in 11 studies and HRV in four studies. Diurnal rhythms were assessed by use of several different measures based on three to eight samples per day for cortisol and melatonin and 24-h recordings for HRV. Most of the studies in the review were small studies with less than 30 participants, and most studies evaluated diurnal rhythms after only two consecutive night shifts whereas only six studies used seven or more consecutive night shifts. The majority of studies found that adaptation to night work had not occurred after two consecutive night shifts, whereas a small number found evidence for full adaptation after seven consecutive night shifts based on diurnal rhythms in cortisol and melatonin.

CONCLUSION

There are methodological differences in the field studies analyzing diurnal rhythms and large diversity in the occupational fields studied. Nevertheless, we conclude that diurnal rhythms in cortisol, melatonin and HRV are not adapted to night work after 1-3 consecutive night shifts. Studies are needed to establish how many consecutive night shifts are needed for full adaptation of diurnal rhythms to night work.

Associations between life stress and subclinical cardiovascular disease are partly mediated by depressive and anxiety symptoms

BACKGROUND

Stress experienced during childhood or adulthood has been associated with cardiovascular disease (CVD), but it is not clear whether associations are already prevalent on a subclinical cardiovascular level. This study investigates associations between indicators of life stress and subclinical CVD, and whether these are mediated by depression and anxiety.

METHODS

Subjects were 650 participants of the Netherlands Study of Depression and Anxiety, aged 20-66 years, with or without (27.5%) depressive and anxiety disorders. Life stress included childhood trauma, negative life events and recently experienced daily hassles or job strain. Subclinical CVD was measured as 1) carotid atherosclerosis (intima-media thickness and the presence of plaques) using B-mode ultrasonography, and 2) central arterial stiffness (heart rate normalized augmentation index) using calibrated radial applanation tonometry.

RESULTS

Increased central arterial stiffness was shown in subjects who had experienced childhood trauma (per SD increase: β=.07; p=.01), or reported recently experienced daily hassles (per SD increase: β=.06; p=.02), negative life events (per SD increase: β=.05; p=.03), or job strain (high versus low: β=.09; p=.01). Associations between life stress and arterial stiffness appeared to be partly mediated by severity of depressive and anxiety symptoms. No significant associations were found for childhood life events, nor between indicators of life stress and carotid atherosclerosis.

CONCLUSIONS

Childhood trauma and recent life stress were associated with increased central arterial stiffness. This suggests that life stress - partly via depression and anxiety - might enhance the development and progression of CVD.

Effects of adverse life events on heart rate variability, cortisol, and C-reactive protein

OBJECTIVE

Our objective was to assess whether self-reported adverse life events during childhood or over the lifespan are associated with altered activity of the autonomic nervous system (ANS), the hypothalamic-pituitary-adrenal axis (HPA axis), and the immune system.

METHOD

This study was performed in a population-based cohort of 1094 adults aged 33-79 years, 46.3% male, average age 53 (SD 11.4). Two waves of data were collected at a 2-year interval, enabling replication of the analyses. Cumulative exposure to adverse life events was assessed by means of the List of Threatening Experiences. ANS function was assessed by spectral analysis of heart rate variability in the high-frequency band (HRV-HF). HPA axis function was assessed by 24-h urinary free cortisol (24-h UFC) excretion. Inflammation was assessed by high-sensitive C-reactive protein (hsCRP).

RESULTS

Multiple linear regression analyses did not reveal any significant associations, with the exception of one significant negative association between the lifetime score of adverse life events and HRV-HF β = -0.028; P = 0.037 at baseline, but not at follow up 2 years later.

CONCLUSION

In a large population-based cohort, adverse life events were not consistently associated with HRV-HF, 24-h UFC or (hsCRP).

The psychological and physiological effects of acute occupational stress in new anesthesiology residents: a pilot trial

BACKGROUND

Occupational stress in resident physicians has profound implications for wellness, professionalism, and patient care. This observational pilot trial measured psychological and physiological stress biomarkers before, during, and after the start of anesthesia residency.

METHODS

Eighteen physician interns scheduled to begin anesthesia residency were recruited for evaluation at three time points: baseline (collected remotely before residency in June 2013); first-month visit 1 (July); and follow-up visit 2 (residency months 3 to 5, September-November). Validated scales were used to measure stress, anxiety, resilience, and wellness at all three time points. During visits 1 and 2, the authors measured resting heart-rate variability, responses to laboratory mental stress (hemodynamic, catecholamine, cortisol, and interleukin-6), and chronic stress indices (C-reactive protein, 24-h ambulatory heart rate and blood pressure, 24-h urinary cortisol and catecholamines, overnight heart-rate variability).

RESULTS

Thirteen interns agreed to participate (72% enrollment). There were seven men and six women, aged 27 to 33 yr. The mean ± SD of all study variables are reported.

CONCLUSION

The novelty of this report is the prospective design in a defined cohort of residents newly exposed to the similar occupational stress of the operating environment. Because of the paucity of literature specific to the measures and stress conditions in this investigation, no data were available to generate a priori definition of primary outcomes and a data analytic plan. These findings will allow power analysis for future design of trials examining occupational stress and stress-reducing interventions. Given the importance of physician burnout in our country, the impact of chronic stress on resident wellness requires further study.

Effects of work stress and home stress on autonomic nervous function in Japanese male workers

Autonomic imbalance is one of the important pathways through which psychological stress contributes to cardiovascular diseases/sudden death. Although previous studies have focused mainly on stress at work (work stress), the association between autonomic function and stress at home (home stress) is still poorly understood. The purpose was to clarify the effect of work/home stress on autonomic function in 1,809 Japanese male workers. We measured corrected QT (QTc) interval and QT index on the electrocardiogram along with blood pressure and heart rate. Participants provided self-reported information about the presence/absence of work/home stress and the possible confounders affecting QT indicators. Home stress was related positively to QT index (p=0.040) after adjusting for the possible confounders, though work stress did not show a significant relation to QTc interval or QT index. The odds ratio of home stress to elevated QT index (≥105) was 2.677 (95% CI, 1.050 to 6.822). Work/home stress showed no significant relation to blood pressure or heart rate. These findings suggest that autonomic imbalance, readily assessed by QT indicators, can be induced by home stress in Japanese workers. Additional research is needed to identify different types of home stress that are strongly associated with autonomic imbalance.

Timing of pre-dose baseline electrocardiograms in clinical trials: increased sampling over a prolonged baseline period worsens variance of QTc

BACKGROUND AND PURPOSE

The US Food and Drug Administration (US FDA) currently recommends recording of electrocardiograms (ECGs) prior to drug administration in thorough QT studies over an hour or more time to improve reliability of baseline ECG values. However, the baseline period is usually in the morning during a period of intense trial activity and rapid circadian change in QTc. The purpose of this study was to determine if the practice of recording an extended baseline does, in fact, decrease QTc variance at baseline.

METHODS

ECG data from three thorough QT studies (TQTS) in which three ECGs (commonly referred to as triplicates) were recorded at each of three pre-specified time points during the 60 to 90 minutes before drug administration were analyzed by determining the intra-subject and inter-subject standard deviation (SD) of QTcF (Fridericia-correct QT) for each of the three pre-drug time points and for the three time points combined.

RESULTS

QTcF was relatively normally distributed in each study. Intra-subject variability of QTcF was greater for the combined triplicate recordings than for the individual triplicates at baseline treatment time points in 39 of 42 cases (93%). This was the case in 48% of the comparisons in the inter-subject analysis.

CONCLUSIONS

The practice of recording three sets of triplicate ECGs over an hour or more before drug administration in a TQTS increases variability of baseline QTcF consistently in cross-over designed trials, and in roughly half of parallel comparisons. Higher variability suggests that the three-triplicate approach does not provide a more reliable baseline value. Less variability of QTcF can be obtained by simply recording one triplicate prior to drug administration. This principal may apply to other ECG and other physiological variables that have a monotonic circadian trend or that may be affected by intense trial activity during the pre-drug hour.

The role of physical activity and heart rate variability for the control of work related stress

Physical activity (PA) and exercise are often used as tools to reduce stress and therefore the risk for developing cardiovascular diseases (CVD). Meanwhile, heart rate variability (HRV) has been utilized to assess both stress and PA or exercise influences. The objective of the present review was to examine the current literature in regards to workplace stress, PA/exercise and HRV to encourage further studies. We considered original articles from known databases (PubMed, ISI Web of Knowledge) over the last 10 years that examined these important factors. A total of seven studies were identified with workplace stress strongly associated with reduced HRV in workers. Longitudinal workplace PA interventions may provide a means to improve worker stress levels and potentially cardiovascular risk with mechanisms still to be clarified. Future studies are recommended to identify the impact of PA, exercise, and fitness on stress levels and HRV in workers and their subsequent influence on cardiovascular health.