The physiological reaction to psychological stress, involving the hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullary axes, is well characterized, but its link to cardiovascular disease risk is not well understood. Epidemiological data show that chronic stress predicts the occurrence of coronary heart disease (CHD). Employees who experience work-related stress and individuals who are socially isolated or lonely have an increased risk of a first CHD event. In addition, short-term emotional stress can act as a trigger of cardiac events among individuals with advanced atherosclerosis. A stress-specific coronary syndrome, known as transient left ventricular apical ballooning cardiomyopathy or stress (Takotsubo) cardiomyopathy, also exists. Among patients with CHD, acute psychological stress has been shown to induce transient myocardial ischemia and long-term stress can increase the risk of recurrent CHD events and mortality. Applications of the 'stress concept' (the understanding of stress as a risk factor and the use of stress management) in the clinical settings have been relatively limited, although the importance of stress management is highlighted in European guidelines for cardiovascular disease prevention.

Stress and cardiovascular disease

Mainstream psychological stress theory claims that it is important to include information on people's ways of coping with work stress when assessing the impact of stressful psychosocial work environments on health. Yet, some widely used respective theoretical models focus exclusively on extrinsic factors. The model of effort-reward imbalance (ERI) differs from them as it explicitly combines information on extrinsic and intrinsic factors in studying workers' health. As a growing number of studies used the ERI model in recent past, we conducted a systematic review of available evidence, with a special focus on the distinct contribution of its intrinsic component, the coping pattern "over-commitment", towards explaining health. Moreover, we explore whether the interaction of intrinsic and extrinsic components exceeds the size of effects on health attributable to single components. Results based on 51 reports document an independent explanatory role of "over-commitment" in explaining workers' health in a majority of studies. However, support in favour of the interaction hypothesis is limited and requires further exploration. In conclusion, the findings of this review support the usefulness of a work stress model that combines extrinsic and intrinsic components in terms of scientific explanation and of designing more comprehensive worksite stress prevention programs.

Associations of Extrinsic and Intrinsic Components of Work Stress with Health: A Systematic Review of Evidence on the Effort-Reward Imbalance Model

Stress is known to negatively affect health and is a potentially serious barrier to diabetes-related health outcomes. This paper synthesizes what is known about stress and glycemic control among people with type 1 and type 2 diabetes across the lifespan. Chronic stress-especially in relation to living with diabetes-was most strongly associated with A1c, particularly among subgroups that face disproportionate stress, such as minority groups or adolescents/young adults. Mechanisms of the stress-A1c association include physiological, psychological, behavioral, and environmental links. Understanding the dimensions of stress as they relate to health in diabetes can be of significant clinical importance, and interventions targeting mechanisms that either exacerbate or buffer stress have reported modest improvements in A1c.

Stress and A1c Among People with Diabetes Across the Lifespan.

The Allostatic Load Index (ALI) has been used to establish associations between stress and health-related outcomes. This review summarizes the measurement and methodological challenges of allostatic load in occupational settings. Databases of Medline, PubPsych, and Cochrane were searched to systematically explore studies measuring ALI in working adults following the PRISMA statement. Study characteristics, biomarkers and methods were tabulated. Methodological quality was evaluated using a standardized checklist. Sixteen articles (2003–2013) met the inclusion criteria, with a total of 39 (range 6–17) different variables used to calculate ALI. Substantial heterogeneity was observed in the number and type of biomarkers used, the analytic techniques applied and study quality. Particularly, primary mediators were not regularly included in ALI calculation. Consensus on methods to measure ALI in working populations is limited. Research should include longitudinal studies using multi-systemic variables to measure employees at risk for biological wear and tear.

https://www.jstage.jst.go.jp/article/indhealth/advpub/0/advpub_2014-0122/_pdf

Measuring Allostatic Load in the Workforce—A Systematic Review

While epidemiological studies provide statistical evidence on associations of exposures such as stressful work with elevated risks of stress-related disorders (e.g., coronary heart disease or depression), additional information on biological pathways and biomarkers underlying these associations is required. In this contribution, we summarize the current state of the art on research findings linking stressful work, in terms of an established theoretical model-effort-reward imbalance-with a broad range of biomarkers. Based on structured electronic literature search and recent available systematic reviews, our synthesis of findings indicates that associations of work stress with heart rate variability, altered blood lipids, and risk of metabolic syndrome are rather consistent and robust. Significant relationships with blood pressure, heart rate, altered immune function and inflammation, cortisol release, and haemostatic biomarkers were also observed, but due to conflicting findings additional data will be needed to reach a firm conclusion. This narrative review of empirical evidence supports the argument that the biomarkers under study can act as mediators of epidemiologically established associations of work stress, as measured by effort-reward imbalance, with incident stress-related disorders.

https://www.mdpi.com/1660-4601/14/11/1373/pdf

Work Stress and Altered Biomarkers: A Synthesis of Findings Based on the Effort–Reward Imbalance Model

Objectives: Previous studies examining the association between job stress and blood lipids have produced mixed findings. We sought to investigate the association between job stress and blood lipids among Chinese workers. Methods: A total of 544 subjects (367 men and 177 women) without known diseases from the Stress and Health in Shenzhen Workers (SHISO) cross-sectional study were analyzed. Job stress was evaluated by the effort-reward imbalance (ERI) model. The associations between job stress and blood lipids, such as for total cholesterol (TCHO), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), were explored by multiple linear regression. The association between job stress and combined dyslipidemia was examined by multiple logistic regression. Results: Compared with their corresponding low level groups, groups with high levels of effort, overcommitment and ERI had a significantly increased risk of combined dyslipidemia with adjusted odd ratios (ORs) of 3.5 (95% CI 1.8-6.7), 4.2 (95% CI 2.3-7.7) and 2.7 (95% CI 1.5-5.1), respectively, whereas high rewards significantly reduced the risk of combined dyslipidemia (adjusted OR 0.3, 95% CI 0.2-0.6) compared with low rewards. Effort, overcommitment and ERI were significantly positively related to TG and LDL-C, while rewards were inversely related to them. No significant associations were observed between job stress and TCHO and HDL-C. The results were similar for men and women. Conclusions: Effort, overcommitment, low reward and ERI increased the risk of dyslipidemia among Chinese workers, and they were significantly associated with TG and LDL-C rather than TCHO or HDL-C. Increasing blood lipids may be the possible link between job stress and coronary heart disease.

/pdf/association-between-job-stress-and-newly-detected-combined-29c43elph5.pdf

Association between job stress and newly detected combined dyslipidemia among Chinese workers: findings from the SHISO study.

OBJECTIVES Carotid intima-media thickness (CIMT) can be used as a surrogate marker for cardiovascular health, and job stress is a risk factor for cardiovascular disease. However, there have been a limited number of studies focusing on the association between job stress and CIMT. The goal of this study was to explore the association between job stress and CIMT in a Chinese working population. METHODS The study included 734 participants (508 males and 226 females) without coronary heart disease. Job stress was evaluated using the effort-reward imbalance (ERI) questionnaire at work. ERI is the ratio between efforts and rewards (weighted by number of items). High resolution carotid ultrasonographic studies were performed using a Sequoia 512 ultrasound system with an 8-13 MHz linear array transducer to assess CIMT. RESULTS This study detected gender-specific associations between the indictors of the ERI model and increased CIMT among the study participants in China. This study demonstrated a robust association in women between the key indicators of ERI, effort, overcommitment and ERI, and increased CIMT (adjusted r(2)=0.258, p=0.001; adjusted r(2)=0.261; p<0.001; adjusted r(2)=0.274; p<0.001, respectively). Reward was inversely correlated with CIMT (adjusted r(2)=0.282, p<0.001), controlling for age, hypertension, diabetes mellitus, hyperlipidaemia and body mass index. For men, a similar pattern of associations was observed, but the associations were lost after adjustment for confounders. CONCLUSIONS Our results show that effort, overcommitment and ERI may be associated with early atherosclerosis predicted by CIMT in women, and reward is inversely related to CIMT.

Job Stress and Carotid Intima-media Thickness in Chinese Workers

Objective
The studies focusing on effort–reward imbalance and diabetes mellitus (DM)/glycosylated hemoglobin (HbA1c) are rare. We sought to examine the association between job tress evaluated by effort–reward imbalance (ERI) model and HbA1c in a Chinese population.

Association between effort-reward imbalance and glycosylated hemoglobin (HbA1c) among Chinese workers: results from SHISO study.

Background

Little is known about the effect of effort–reward imbalance (ERI) on fibrinogen. We aimed to examine the association between ERI and fibrinogen among Chinese workers.



Methods

A total of 732 subjects without vascular diseases were analyzed. Associations between job stress evaluated by ERI model and plasma fibrinogen were explored by multiple regression.



Results

Effort, overcommitment, and ERI were significantly positively associated with fibrinogen, while reward was negatively related with fibrinogen both for men and for women. Compared with low level group, high level of effort, overcommitment, and ERI significantly increased risk of elevated fibrinogen (more than mean concentration) with adjusted OR of 3.3, 12.5, and 7.7 for men; 2.9, 7.2, and 7.2 for women, respectively; however, high reward reduced 80% risk for elevated fibrinogen.



Conclusions

Effort, overcommitment, and ERI are significantly associated with fibrinogen among Chinese workers. High fibrinogen may be a possible link between job stress and cardiovascular disease. Am. J. Ind. Med. 55:167–175, 2012. © 2011 Wiley Periodicals, Inc.

Plasma fibrinogen: A possible link between job stress and cardiovascular disease among Chinese workers

Background

No previous studies investigated the interaction of effort-reward imbalance (ERI) and overcommitment on blood pressure. Our aim was to investigate associations of ERI and overcommitment (and their interaction) with blood pressure and hypertension within a Chinese population.



Methods

Seven hundred thirty-four participants from the Stress and Health in Shenzhen Workers study completed a demographics, job stressor and risk factor questionnaire, and their blood pressure was measured by mercury sphygmomanometers. Risk factors for blood pressure were analyzed by multiple linear regression and risk factors for hypertension by Poisson regression.



Results

Overcommitment was associated with diastolic blood pressure after adjustment for confounders and ERI among men (β = 0.17, P < 0.05); ERI was also associated with diastolic blood pressure and systolic blood pressure after adjustment for confounders and overcommitment. High overcommitment (PR 1.91, 95% CI 1.35–2.69), and ERI (PR = 2.47, 95% CI 1.62–3.75) were each associated with risk of hypertension after adjusting for confounders. After adjusting for ERI, the association with overcommitment was no longer significant (PR = 1.24, 95% CI 0.85–1.82) However, after controlling for overcommitment, ERI remained significantly associated with hypertension risk (PR = 2.38, 95% CI 1.53–3.71). When high overcommitment and high ERI was combined, hypertension risk was highest (adjusted PR = 2.99, 95% CI 1.82–4.91, adjusted synergy index 5.85). The interaction was significant when it was tested by an interaction term in the regression (P < 0.001).



Conclusions

The interaction effect of overcommitment and ERI on hypertension was independent and synergistic. Am. J. Ind. Med. 56:1433–1441, 2013. © 2013 Wiley Periodicals, Inc.

Juan Hang

Papers

Association between job stress and newly detected combined dyslipidemia among Chinese workers: findings from the SHISO study.

Job Stress and Carotid Intima-media Thickness in Chinese Workers

Association between effort-reward imbalance and glycosylated hemoglobin (HbA1c) among Chinese workers: results from SHISO study.

Plasma fibrinogen: A possible link between job stress and cardiovascular disease among Chinese workers

The interaction effect of effort-reward imbalance and overcommitment on hypertension among Chinese workers: Findings from SHISO study