Job strain, Type A behavior pattern, and the prevalence of coronary atherosclerosis in Japanese working men

Morphological Characteristics of Culprit Plaques in Acute Myocardial Infarction Patients With Different Scores of Type A Personality - An Intravascular Optical Coherence Tomography Study

BACKGROUND

Previous studies have suggested a relationship between type A personality and the occurrence of coronary artery disease, so we used intravascular optical coherence tomography (OCT) to investigate the morphological characteristics of culprit plaques in acute myocardial infarction (AMI) patients with different scores of type A personality.Methods and Results: A total of 221 AMI patients who underwent preintervention imaging of culprit lesions and an assessment of type A behavior pattern were included. According to the scores for the behavior questionnaire, these patients were divided into 3 groups: non-type A personality (n=91), intermediate personality (n=73), and type A personality (n=57). Patients with type A personality were younger (P=0.003) and had a higher level of total cholesterol (P=0.029) and more severe luminal stenosis (P=0.046). In addition, the prevalence of microchannels (P<0.001), macrophage accumulation (P<0.001), and plaque rupture (P=0.010) with greater number (P<0.001), cavity angle (P<0.001), and length (P<0.001) was highest in the type A personality group.

CONCLUSIONS

The culprit lesions of AMI patients with increased scores for type A personality had more severe coronary luminal stenosis, and the proportion of vulnerable features was increased.

Associations between Job Strain and Arterial Stiffness: A Large Survey among Enterprise Employees from Thailand

As an intermediate endpoint to cardiovascular disease, arterial stiffness has received much attention recently. So far, the research on work stress and arterial stiffness is still sparse and inconsistent, and no investigations on work stress and cardiovascular health among the Thai working population have been reported. Therefore, we conducted an epidemiological study among 2141 Thai enterprise employees (858 men and 1283 women) who were free from any diagnosed cardiovascular disease. Work stress was measured using Karasek’s Job Demand–Control model for job strain (a combination of high demand and low control). Arterial stiffness was evaluated by a non-invasive approach using pulse-wave analysis based on a finger photoplethysmogram. Multivariable linear regression was applied to examine associations between job strain and arterial stiffness. In men, job strain was significantly associated with arterial stiffness (β  =  0.078, 95% confidence interval  =  0.026 to 0.130), after accounting for sociodemographic, behavioral, dietary and biomedical factors. However, the association in women was not significant. As the first study in Thailand on work stress and cardiovascular risk, we found that job strain might be an important risk factor for cardiovascular disease among Thai working men. Further studies with longitudinal design are warranted.

Associations of job strain and occupation with subclinical atherosclerosis: The CARDIA Study

PURPOSE

Although occupational factors have been associated with symptomatic ischemic heart disease, associations between job strain (low decision latitude and high psychological demands) and risk for subclinical atherosclerosis measured by coronary artery calcium (CAC) have not been assessed.

METHODS

CAC was measured in 3695 participants in the Coronary Artery Risk Development in Young Adults study in 2000 to 2001 and 2005 to 2006. Job characteristics measured by the demand-control model (psychological demands and decision latitude) were assessed in 1987 to 1988 and in 1995 to 1996. Associations between non-zero CAC and previous job characteristics and occupation were assessed, adjusting for potential covariates.

RESULTS

Low decision latitude, high psychological demands, and job strain at either earlier examination were not associated with a positive CAC, nor were changes in the status of these job characteristics between 1987/1988 and 1995/1996. However, participants whose jobs were classified as managerial or professional in 1995/1996 were less likely to have a positive CAC than those in laborer occupations.

CONCLUSIONS

Job strain measured at two earlier time points was not related to the presence of CAC at follow-up 5 to 18 years later. The association between earlier occupation and CAC may reflect socioeconomic differences or other occupational, industrial, or labor market characteristics.

The association between effort-reward imbalance and coronary atherosclerosis in a Chinese sample

BACKGROUND

Previous studies of job strain and coronary heart disease (CHD) have produced mixed findings. We aimed to examine the association between job stress evaluated by the effort-reward imbalance (ERI) model and coronary atherosclerosis assessed by coronary angiography in a Chinese sample.

METHODS

Three-hundred twenty participants accepting coronary angiography for the first time were enrolled in series. Job stressors were evaluated by the ERI model. The presence and severity of CHD were assessed by measuring the coronary artery stenosis (the presence of >50% luminal stenosis in one or more major coronary arteries). The association between job stressors and CHD was examined by multivariate analysis.

RESULTS

Compared with the low-level group, high-level effort, overcommitment, and ERI increased CHD risk with odds ratio (OR) 2.5 (95% confidence interval (CI): 1.2-5.0), 2.5 (95% CI: 1.2-5.0), 2.4 (95% CI: 1.2-4.9), respectively, after adjustment for confounders. They were also significantly positively correlated with the complexity of coronary artery lesions, respectively. Dose-response relationships were observed.

CONCLUSIONS

ERI was associated with coronary artery lesions in a sample of Chinese workers. Longitudinal research and interventional designs are needed to confirm the mechanism and to provide evidence for the prevention of CHD.

Job stress and coronary heart disease: a case-control study using a Chinese population

OBJECTIVES

This study was to examine the association between job stress and coronary heart disease (CHD) in a Chinese population.

METHODS

The 388 participants aged 30 to 70 yr who received coronary angiography for suspected or known ischemic heart disease were enrolled in this series, which included 292 CHD cases and 96 controls. The job stress before CHD onset was measured by the effort-reward imbalance (ERI) model.

RESULTS

In the results, compared with the baseline, high ERI, high extrinsic effort or high overcommitment increased the risk of CHD with odds ratios (OR) of 2.8, 2.7 and 2.8 respectively after adjustment for the traditional CHD risk factors, such as age, gender, primary hypertension, diabetes mellitus, hyperlipidemia, smoking, body mass index, CHD family history, educational level, and marital status. The combination of high ERI and high overcommitment led to the highest risk of CHD with adjusted OR 5.5. However, high reward reduced the risk of CHD with an adjusted OR of 0.4 in comparison to low reward. Dose-response relationships were also observed.

CONCLUSIONS

Job stress evaluated by the ERI model significantly increased the risk of CHD, and it may be an important risk factor independent of the traditional risk factors of CHD in the Chinese population.

Relationship between two alternative occupational stress models and arterial stiffness: a cross-sectional study among Japanese workers

OBJECTIVE

Numerous studies have reported the relationships between job characteristics and coronary heart diseases. However, there are only a few reports on the association between occupational stresses and arterial stiffness as a marker of early stage arthrosclerosis. The aim of this study was to clarify the relationship between occupational stress models--Siegrist's effort reward imbalance and Karasek's demand control model (DCM)--and arterial stiffness using brachial-ankle pulse-wave velocity (baPWV).

METHODS

The participants were local government employees (3,412 men and 854 women) aged 35 and over who had their annual health checkups. The associations between occupational stress questionnaires of the two theoretical models and a risk of increased arterial stiffness using baPWV were examined.

RESULTS

On performing multiple linear regression analysis after fully adjusting the model, high strain, which was defined as a combination of both low job control and high job demands in the DCM, was found to be significantly associated with a high risk of arterial stiffness (P = 0.027) in women. However, in men, although low job control was positively significant with a high value of baPWV adjusted for each step, modest but not significant association was found after adjustment for all covariates.

CONCLUSION

In conclusion, the present study indicates that high strain indicated by high demands and low control is associated with increased arterial stiffness in women. The types of job stress associated with a high risk of arterial stiffness may differ by gender.

Associations between working conditions and angina pectoris symptoms among employed women

OBJECTIVE

This study aimed to examine whether psychosocial working conditions are associated with angina pectoris (AP) symptoms in women.

METHODS

Data were derived from postal questionnaires filled in by 40- to 60-year-old women employed by the City of Helsinki, Finland, in 2000 to 2002 (n = 7093, response rate 67%). AP symptoms were measured by the Rose Questionnaire. Logistic regression analyses were carried out to examine AP symptoms as outcome. Independent variables consisted of Karasek's job demands and job control, work fatigue, working overtime, work-related mental and physical strain, the work-home interface, and social support, adjusted for age. Confounding effects of socioeconomic status, health behaviors (smoking, binge drinking, body mass index), and menopause were also examined. Pregnant women were excluded.

RESULTS

AP symptoms were reported by 6% of participants. Work fatigue was strongly associated with AP. In addition, working overtime, low job control, and high physical strain at work were associated with AP. The associations between psychosocial working conditions and AP symptoms were unaffected by health behaviors, socioeconomic status, or menopause.

CONCLUSIONS

Working conditions were associated with the AP symptoms identified by the Rose Questionnaire. Longitudinal studies are needed to disentangle the causal relationships, i.e., whether psychosocial stress is a true risk factor/cause of angina symptoms and cardiovascular disease among women.

Impact of Type A Behavior on Brachial-Ankle Pulse Wave Velocity in Japanese

Pulse wave velocity (PWV) is the velocity of a pulse wave traveling a given distance between 2 sites in the arterial system, and is a well-known indicator of arteriosclerosis. Brachial-ankle PWV (baPWV) is a parameter more simple to obtain, compared with the conventional PWV, and is an easy and effective means of evaluating arteriosclerosis. BaPWV can be obtained by only wrapping the four extremities with blood pressure cuffs, and it can be easily used to screen a large number of subjects. Type A behavior has been confirmed as an independent risk factor for the development of coronary heart disease. To examine the relationship between Type A behavior and arteriosclerosis, 307 normal Japanese subjects were classified into either a Type A group (n = 90) or a non-Type A group (n = 217) by using Maeda's Type A Scale. BaPWV was evaluated using a PWV diagnosis device. The baPWV in the Type A group was significantly higher than that obtained in the non-Type A group. The baPWV showed a positive correlation with age both in the Type A group and in the non-Type A group; however, the straight-line regression slope of baPWV versus age in the Type A group was significantly larger than that in the non-Type A group. Therefore, our results suggest that arteriosclerosis might be promoted earlier in subjects expressing the Type A behavior pattern. Type A behavior pattern is confirmed as a risk factor for arteriosclerosis, and may increase the risk of the cardiovascular disease related to arteriosclerosis.

Relation between type A behavior pattern and the extent of coronary atherosclerosis in Japanese women

This study examined the relation of Type A behavior pattern and its components to angiographically documented coronary atherosclerosis in 198 Japanese women. A questionnaire-based interview elicited psychosocial and other factors. Type A behavior pattern was measured by 12 questions. Significant coronary stenosis was defined when a 75% or greater luminal narrowing occurred at one or more major coronary arteries or 50% or greater narrowing occurred at the left main artery. Gensini's score also was calculated. Logistic regression analysis was used to calculate odds ratios and 95% confidence intervals with adjustment for traditional coronary risk factors and the presence of a job. Global Type A behavior pattern showed no material association with the severity of coronary atherosclerosis assessed by both Gensini's score and the presence of significant coronary stenosis. However, its subcomponents, enthusiasm and competitiveness, were positively related to the severity of coronary atherosclerosis, whereas self-confidence and perfectionism were negatively related. These findings suggest overall a null association between global Type A and coronary atherosclerosis as well as the presence of toxic or beneficial components of Type A behaviors in Japanese women.

Overtime work, insufficient sleep, and risk of non-fatal acute myocardial infarction in Japanese men

OBJECTIVES

To examine the relation between working hours and hours of sleep and the risk of acute myocardial infarction (AMI), with special reference to the joint effect of these two factors.

METHOD

Case-control study in Japan. Cases were 260 men aged 40-79 admitted to hospitals with AMI during 1996-8. Controls were 445 men free from AMI matched for age and residence who were recruited from the resident registers. Odds ratios of AMI relative to mean weekly working hours and daily hours of sleep in the past year or in the recent past were calculated.

RESULTS

Weekly working hours were related to progressively increased odds ratios of AMI in the past year as well as in the past month, with a twofold increased risk for overtime work (weekly working hours >or=61) compared with working hours <or=40. Short time sleep (daily hours of sleep <or=5) and frequent lack of sleep (2 or more days/week with <5 hours of sleep) were also associated with a two to threefold increased risk. Frequent lack of sleep and few days off in the recent past showed greater odds ratios than those in the past year.

CONCLUSIONS

Overtime work and insufficient sleep may be related to increased risk of AMI.