Job strain and prevalence of hypertension in a biracial population of urban bus drivers

Predictors for diabetes and hypertension among bus drivers and conductors in South India

Bus drivers and conductors are facing various health hazards due to stressful working conditions. They are exposed to various occupational hazards which lead to deterioration of their health over a period of time. Therefore, it is of interest to evaluate the prevalence of diabetes and hypertension among bus drivers and conductors and to determine the factors associated with diabetes and hypertension. This cross-sectional study was done among 293 bus drivers and 157 conductors during March 2018 to December 2018 and the data was collected using a semi structured questionnaire after obtaining informed consent. Each individual was investigated for Blood sugar and Blood Pressure. Out of 450 study participants, about 6.9% were diabetic and 50.2% were hypertensive. Transport workers with single marital status, those who belong to rural areas and drivers were significant predictors for diabetes. Overweight was significantly associated with the Diabetes in negative direction. Marital status, years of experience and anxiety were significantly associated with hypertension. Hemoglobin level, total cholesterol level and blood urea level also emerged as predictors for Hypertension. Non-communicable diseases like diabetes and hypertension have surpassed the communicable diseases in affecting the health of people with distinct occupations like bus drivers and conductors.

Self-Employment, Working Hours, and Hypertension by Race/Ethnicity in the USA

There is a large literature on work-related characteristics and hypertension, but studies on self-employment, longer working hours, and hypertension are mixed. Assessments of self-employment should be extended to account for people with part-time self-employment (i.e., employees also earning income from self-employment). The aim of this study was to determine the association of different types of self-employment with hypertension among adults by race/ethnicity and to assess whether longer working hours moderated these associations. Using data from the 2007-2018 National Health and Nutrition Examination Survey, measured hypertension (blood pressure ≥ 140/90 mm Hg) was assessed and employment categories included employees, part-time self-employment (i.e., employee with self-employment income), or full-time self-employment. Modified Poisson regressions and multiplicative interaction terms were used. Having full-time self-employment was associated with lower relative risk (RR) of hypertension compared to employees among Black (RR = 0.77, 95% confidence interval (CI) = 0.61-0.96) and White men (RR = 0.77, 0.65-0.93) compared to employees. Full-time self-employment was associated with higher risk of hypertension (RR = 1.36, 95% CI = 1.01-1.82) compared to employees among Hispanic women, while part-time self-employment was associated with lower risk (RR = 0.69, 95% CI = 0.48-0.98). Among White women, part-time self-employment was associated with higher relative risk of hypertension (RR = 1.27, 95% CI = 1.05-1.53) compared to employees. There were significant interactions between employment categories and longer working hours among Hispanic women as well as Black women and men. The results suggest that self-employment categories and longer working hours impact hypertension by race/ethnicity and sex. Because the number of full-time and part-time self-employed adults has increased, the health of this particular subgroup of workers should be further addressed.

The necessity of improving cardiovascular health in commercial motor vehicle drivers

Commercial motor vehicle (CMV) drivers have an increased risk for cardiometabolic risk factors and higher rates of cardiovascular disease relative to the general population. Lifestyle factors, including the sedentary nature of driving and lack of access to healthy foods, contribute to the disproportionately high cardiovascular disease (CVD) risk among commercial vehicle (CMV) drivers. Occupational physicals represent an important opportunity to reach populations with a high prevalence and incidence of coronary artery disease who may not otherwise seek preventive care. These visits are an opportunity to discuss primary and secondary prevention, including lifestyle topics such as diet and exercise, and potentially recommend or implement preventive medical therapy when indicated. Future iterations of licensing guidelines for drivers should seek to incorporate updated recommendations regarding diet, physical activity, and preventive pharmacologic therapies.

Cardiovascular risk in high-hazard occupations: the role of occupational cardiology

Work is beneficial for health, but many individuals develop cardiovascular disease (CVD) during their working lives. Occupational cardiology is an emerging field that combines traditional cardiology sub-specialisms with prevention and risk management unique to specific employment characteristics and conditions. In some occupational settings incapacitation through CVD has the potential to be catastrophic due to the nature of work and/or the working environment. These are often termed 'hazardous' or 'high-hazard' occupations. Consequently, many organizations that employ individuals in high-hazard roles undertake pre-employment medicals and periodic medical examinations to screen for CVD. The identification of CVD that exceeds predefined employer (or regulatory body) risk thresholds can result in occupational restriction, or disqualification, which may be temporary or permanent. This article will review the evidence related to occupational cardiology for several high-hazard occupations related to aviation and space, diving, high altitude, emergency workers, commercial transportation, and the military. The article will focus on environmental risk, screening, surveillance, and risk management for the prevention of events precipitated by CVD. Occupational cardiology is a challenging field that requires a broad understanding of general cardiology, environmental, and occupational medicine principles. There is a current lack of consensus and contemporary evidence which requires further research. Provision of evidence-based, but individualized, risk stratification and treatment plans is required from specialists that understand the complex interaction between work and the cardiovascular system. There is a current lack of consensus and contemporary evidence in occupational cardiology and further research is required.

Professional Driver's Job Stress and 8-year Risk of Cardiovascular Disease: The Taiwan Bus Driver Cohort Study

BACKGROUND

Two main job stress models-the Demand-Control-Support (DC) model and the Effort-Reward Imbalance (ERI) model have been used to assess the impact of psychosocial work-related factors for cardiovascular disease (CVD). Limited evidence elaborates the independent and combined effects on CVD events, especially for professional drivers. This study assesses the independent and combined effects of DC and ERI models on an 8-year risk of CVD among professional drivers.

METHODS

The Taiwan Bus Driver Cohort Study recruited 1650 professional drivers from a large bus company in 2005. The subjects were interviewed in person and completed the two job stress questionnaires. Researchers found 94 new cases of CVD (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM]: 390-459) from 2006 to 2012. A Cox proportional hazards model was performed to estimate the hazard ratio (HR) for CVD events.

RESULTS

Occupational drivers with high overcommitment scores (thresholds of 15) had an elevated risk for CVD (HR = 1.71; 95% CI = 1.04, 2.82). Regarding target disease, overcommitment had an increased risk for CVD (not including hypertensive disease) (HR = 1.27; 95% CI = 1.05, 1.54) and ischemic heart disease (HR = 1.32; 95% CI = 1.05-1.65).

CONCLUSION

Overcommitment, which is associated with job stress, appears to be associated with CVD risk in professional drivers.

Work stress and health problems of professional drivers: a hazardous formula for their safety outcomes

Background

Several empirical studies have shown that professional drivers are a vulnerable occupational group, usually exposed to environmental stressors and adverse work conditions. Furthermore, recent studies have associated work-related stress with negative job performances and adverse health outcomes within this occupational group, including cardiovascular diseases and unsafe vehicle operation.

Objective

The aim of this study was to describe the working conditions and the health status of this occupational group, and to evaluate the association between the Demand-Control model of job stress and their self-reported health and safety outcomes.

Methods

A pooled sample of 3,665 Colombian professional drivers was drawn from five different studies. The Job Content Questionnaire and the General Health Questionnaire were used to measure work stress and self-reported mental health, respectively. Additionally, professional drivers self-reported health problems (hypertension, dyslipidemia, diabetes and overweight) and health-related risky behaviors (smoking and sedentary behavior).

Results

Regarding the Job Demands-Control (JDC) model, it was found that approximately a third part of Colombian professional drivers suffer from high job strain (29.1%). Correlational and multivariate analyses suggest that de JDC model of stress is associated with the professional drivers' mental health, traffic accidents and fines, but not with other physical and behavioral health-related outcomes, which are highly prevalent among this occupational group, such as hypertension, dyslipidemia, diabetes, overweight, smoking and sedentary behavior.

Conclusion

The results of this study suggest that (a) stressful working conditions are associated with health and lifestyle-related outcomes among professional drivers, and (b) that evidence-based interventions are needed in order to reduce hazardous working conditions, job stress rates and their negative impact on the health of this occupational group.

Trouble in transit: Organizational barriers to workers' health

BACKGROUND

Valuable insights on the health and behavior of transit workers can be obtained from qualitative research that considers the social environment, which affects job performance and determines levels of perceived stress.

METHODS

Using a grounded theory approach, semi-structured interviews were conducted with American transit workers (n = 32). Recorded interviews were transcribed and analyzed using a constant comparative method.

RESULTS

Participants described categories related to entrenched organizational practices, particularly managements' leadership style, which created an atmosphere of distrust. High demanding work schedules, as a result of technological advances, were discussed in relation to diminished breaks, fatigue, and unhealthy diets. Transit workers also attributed increased work demands and irregular working hours to compromised time with family and friends.

CONCLUSIONS

The described barriers to positive health behaviors and social support underscore the need for interventions that ensure adequate breaks and recovery between shifts and increase safety for transit passengers. Am. J. Ind. Med. 60:350-367, 2017. © 2017 Wiley Periodicals, Inc.

The association between insomnia and cardiovascular risk factors in bus drivers in Iran

BACKGROUND

Road accidents are one of the most important issues in Iran which more than eighteen thousand persons are died annually because of this problem. Among the major reasons for this issue, sleepiness and cardiovascular disorder can be mentioned.

OBJECTIVE

To investigate the association between insomnia and cardiovascular risk factors among professional drivers who are at high risk during driving.

METHODS

A total of 1232 male bus drivers were included in the study and two different kinds of data sets were collected: (1) Sleep disorder information using Athens Insomnia Scale (AIS) and (2) Cardiovascular parameters such as systematic measurement of blood pressure, electrocardiography (ECG), total cholesterol, and triglyceride.

RESULTS

Our study demonstrated that the prevalence of insomnia in professional bus drivers was 8 percent. The study showed significant association between age, diastolic hypertension and work experience with final awakening earlier than desired (P < 0.05), the rate of the triglyceride level and total sleep duration (p = 0.02), and BMI and sleepiness during the day (P < 0.05).

CONCLUSIONS

Our study suggested that elevated serum triglyceride levels and increased diastolic blood pressure may be associated with some sleep complaints in drivers.

Globalization, Work, and Cardiovascular Disease

Cardiovascular disease (CVD), a global epidemic, is responsible for about 30% of all deaths worldwide. While mortality rates from CVD have been mostly declining in the advanced industrialized nations, CVD risk factors, including hypertension, obesity, and diabetes, have been on the increase everywhere. Researchers investigating the social causes of CVD have produced a robust body of evidence documenting the relationships between the work environment and CVD, including through the mechanisms of psychosocial work stressors. We review the empirical evidence linking work, psychosocial stressors, and CVD. These work stressors can produce chronic biologic arousal and promote unhealthy behaviors and thus, increased CVD risk. We offer a theoretical model that illustrates how economic globalization influences the labor market and work organization in high-income countries, which, in turn, exacerbates job characteristics, such as demands, low job control, effort-reward imbalance, job insecurity, and long work hours. There is also a growing interest in “upstream” factors among work stress researchers, including precarious employment, downsizing/restructuring, privatization, and lean production. We conclude with suggestions for future epidemiologic research on the role of work in the development of CVD, as well as policy recommendations for prevention of work-related CVD.

The Health of the Corporate Body: Illness and Organizational Dynamics

The search for ways to cut health care costs in organizations has rarely considered the direct relationship between organizational variables and health. This article hypothesizes that health and illness within a particular organization may be related to the social dynamics of the work setting. Data was gathered from a survey of a corporation with 13,000 employees who work in 16 organizations. An index of reported health symptoms was correlated with scales developed from questions related to organizational issues. Using stepwise multiple regression, 20% of the variance of the aggregate health symptoms was accounted for by three organizational scales (organization-person balance, managerial treatment, and discrimination) after controlling for demographic variables. A second analysis, which focused on the collective dynamics of the 16 organizations, supported the findings of the first analysis. This study found that issues of support, balance, change, and inequity are crucial factors in fostering a healthy work environment.

Psychosocial job factors and biological cardiovascular risk factors in Mexican workers

BACKGROUND

Psychosocial job factors (PJF) have been implicated in the development of cardiovascular disease. The paucity of data from developing economies including Mexico hampers the development of worksite intervention efforts in those regions.

METHODS

This cross-sectional study of 2,330 Mexican workers assessed PJF (job strain [JS], social support [SS], and job insecurity [JI]) and biological cardiovascular disease risk factors [CVDRF] by questionnaire and on-site physical examinations. Alternative formulations of the JS scales were developed based on factor analysis and literature review. Associations between both traditional and alternative job factor scales with CVDRF were examined in multiple regression models, adjusting for physical workload, and socio-demographic factors.

RESULTS

Alternative formulations of the job demand and control scales resulted in substantial changes in effect sizes or statistical significance when compared with the original scales. JS and JI showed hypothesized associations with most CVDRF, but they were inversely associated with diastolic blood pressure and some adiposity measures. SS was mainly protective against CVDRF.

CONCLUSION

Among Mexican workers, alternative PJF scales predicted health outcomes better than traditional scales, and psychosocial stressors were associated with most CVDRF.

Psychosocial work factors, blood pressure and psychological strain in male bus operators

The research aim was to predict the bus operators' blood pressure (BP) and psychological strain using a combination of the Job-Demand Control (JDC) and Effort-Reward Imbalance (ERI) models. The study was conducted with a sample of 139 bus operators in the city of Bogotá (Colombia), who answered a questionnaire that included the Job Content Questionnaire (JCQ), the ERI Questionnaire, and the General Health Questionnaire (GHQ). Four consecutive BP readings taken in the workplace were averaged to calculate an estimation of the bus operators' BP. By conducting multiple linear regressions it was found that, taken together, JDC and ERI models explain 10% (F(11,139)=2,502; p=0.00) of systolic BP variance, and 34% (F(6,139)=8,638; p=0.00) of psychological strain variance. These results suggest that the JDC and ERI predictors provide complementary information which increases the probability of accurately model the bus operators' health.

Hotel housekeeping work influences on hypertension management

BACKGROUND

Characteristics of hotel housekeeping work increase the risk for hypertension development. Little is known about the influences of such work on hypertension management.

METHODS

For this qualitative study, 27 Haitian immigrant hotel housekeepers from Miami-Dade County, FL were interviewed. Interview transcripts were analyzed with the assistance of the Atlas.ti software for code and theme identification.

RESULTS

Influences of hotel housekeeping work on hypertension management arose both at the individual and system levels. Factors at the individual level included co-worker dynamics and maintenance of transmigrant life. Factors at the system level included supervisory support, workload, work pace, and work hiring practices. No positive influences were reported for workload and hiring practices.

CONCLUSIONS

Workplace interventions may be beneficial for effective hypertension management among hotel housekeepers. These work influences must be considered when determining effective methods for hypertension management among hotel housekeepers.

General characteristics and risk factors of cardiovascular disease among interstate bus drivers

Workers in the transportation industry are at greater risk of an incorrect diet and sedentary behavior. The aim of our study was to characterize a population of professional bus drivers with regard to clinical and demographic variables, lipid profile, and the presence of cardiovascular risk factors. Data from 659 interstate bus drivers collected retrospectively, including anthropometric characteristics, systolic and diastolic blood pressure, lipid profile, fasting blood glucose, meatoscopy, and audiometry. All participants were male, with a mean age of 41.7 ± 6.9 years, weight of 81.4 ± 3.3 kg, and BMI 27.2 ± 3.3 Kg/m²; the mean abdominal and neck circumferences were 94.4 ± 8.6 cm and 38.9 ± 2.2  cm; 38.2% of the sample was considered hypertensive; mean HDL cholesterol was 47.9 ± 9.5 mg/dL, mean triglyceride level was 146.3 ± 87.9 mg/dL, and fasting glucose was above 100 mg/dL in 249 subjects (39.1%). Drivers exhibited reduced audiometric hearing at 4-8 kHz, being all sensorineural hearing loss. The clinical characterization of a young male population of interstate bus drivers revealed a high frequency of cardiovascular risk factors, as obesity, hypertension, hyperlipidemia, and hyperglycemia, as well as contributing functional characteristics, such as a low-intensity activity, sedentary behavior, long duration in a sitting position, and high-calorie diet, which lead to excessive weight gain and associated comorbidities.

Occupational stress and hypertension

Occupational stress, or job strain, resulting from a lack of balance between job demands and job control, is considered one of the frequent factors in the etiology of hypertension in modern society. Stress, with its multifactorial causes, is complex and difficult to analyze at the physiological and psychosocial levels. The possible relation between job strain and blood pressure levels has been extensively studied, but the literature is replete with conflicting results regarding the relationship between the two. Further analysis of this relationship, including the many facets of job strain, may lead to operative proposals at the individual and public health levels designed to reduce the effects on health and well-being. In this article, we review the literature on the subject, discussing the various methodologies, confounding variables, and suggested approaches for a healthier work environment.

Job Strain, Workplace Discrimination, and Hypertension among Older Workers: The Health and Retirement Study

Job strain has been associated with hypertension among younger workers; however, whether this relationship persists among older workers, particularly older racial/ethnic minorities, is unresolved. This study evaluated whether job strain and workplace discrimination are associated with hypertension and poor blood pressure control among older workers and whether these relationships vary by gender and race/ethnicity. Data were drawn from the Health and Retirement Study, and analysis was restricted to employed participants with complete information on job strain and blood pressure (N = 3,794). In adjusted models, high job strain was associated with lower likelihood of hypertension (odds ratio (OR): 0.75, 95% confidence interval (CI): 0.63, 0.89) relative to low job strain. Stratified analyses indicated this association was only significant among white (OR: 0.71, 95% CI: 0.58, 0.86) and male (OR: 0.61, 95% CI: 0.47, 0.79) workers. High job strain was not significantly associated with hypertension among African American (OR: 1.14, 95% CI: 0.63, 2.07) or Hispanic (OR: 0.56, 95% CI: 0.29, 1.09) workers. Workplace discrimination was not associated with hypertension among any group. Neither job strain nor discrimination was associated with poor blood pressure control. These findings suggest that persistence in work characterized by high job strain in later life may signal resilience to the influence of work-related stressors on health. Future research efforts should examine the factors that contribute to gender and racial differences in these relationships.

The inverse hazard law: blood pressure, sexual harassment, racial discrimination, workplace abuse and occupational exposures in US low-income black, white and Latino workers

Research on societal determinants of health suggests the existence of an "inverse hazard law," which we define as: "The accumulation of health hazards tends to vary inversely with the power and resources of the populations affected." Yet, little empirical research has systematically investigated this topic, including in relation to workplace exposures. We accordingly designed the United for Health study (Greater Boston Area, Massachusetts, 2003-2004) to investigate the joint distribution and health implications of workplace occupational hazards (dust, fumes, chemical, noise, ergonomic strain) and social hazards (racial discrimination, sexual harassment, workplace abuse). Focusing on blood pressure as our health outcome, we found that among the 1202 low-income multi-racial/ethnic working class participants in our cohort - of whom 40% lived below the US poverty line - 79% reported exposure to at least one social hazard and 82% to at least one high-exposure occupational hazard. Only sexual harassment, the least common social hazard, was associated with elevated systolic blood pressure (SBP) among the women workers. By contrast, no statistically significant associations were detectable between the other additional highly prevalent social and occupational hazards and SBP; we did, however, find suggestive evidence of an association between SBP and response to unfair treatment, implying that in a context of high exposure, differential susceptibility to the exposure matters. These results interestingly contrast to our prior findings for this same cohort, in which we found associations between self-reported experiences of racial discrimination and two other health outcomes: psychological distress and cigarette smoking. Likely explanations for these contrasting findings include: (a) the differential etiologic periods and pathways involving somatic health, mental health, and health behaviors, and (b) the high prevalence of adverse exposures, limiting the ability to detect significant associations. As clarified by the "inverse hazard law," to understand health inequities, research is needed that contrasts exposures and health status population-wide, not just among those most inequitably exposed.

Biological consequences of stress: conflicting findings on the association between job strain and blood pressure

The primary objective is to verify the relation between job strain and clinic blood pressure in a working population from the Milan municipality (1,909 men, 3,786 women) enrolled from 1992 to 1996. Job strain was investigated through the Karasek model. Clinic blood pressure was evaluated using standard procedures from the MONICA project. The association between the two was calculated controlling for age, education, smoking, body mass index, total and high-density lipoprotein (HDL) cholesterol. Significantly, associations were found for systolic blood pressure in men and for both systolic and diastolic blood pressure in women. However, these results do not reflect biological plausibility. The relationship between job strain and blood pressure is an unfinished business: sample characteristics and measurement methods should be carefully considered.

High Job Strain and Ambulatory Blood Pressure in Middle-Aged Men and Women From the Belgian Job Stress Study

OBJECTIVE

The aim of this study was to assess whether job strain is associated with 24-hour ambulatory blood pressure measurements within a subsample of the Belgian Job Stress Project (BELSTRESS) population.

METHODS

A group of 89 middle-aged male and female workers perceiving high job strain and an equally large group of workers perceiving no high job strain wore an ambulatory blood pressure monitor for 24 hours on a regular working day.

RESULTS

Mean ambulatory blood pressure at work, at home, and while asleep was significantly higher in workers with job strain as compared with others. The associations between job strain and ambulatory blood pressure were independent from the covariates.

CONCLUSIONS

Within this study, high job strain was an important independent risk factor for higher ambulatory blood pressure at work, at home, and during sleep in a group of men and women.

Stroke among male professional drivers in Denmark, 1994-2003

OBJECTIVES

(1) To estimate the relative risk of stroke among various groups of professional drivers; (2) to determine if any excess risk should be attributed to infarction or haemorrhage; (3) to estimate the relative risk ratio for stroke among professional drivers living in Greater Copenhagen compared to those living outside the metropolis.

METHODS

A cohort of 6285 bus drivers, 4204 car, taxi, and van drivers, and 25,879 heavy truck and lorry drivers were followed up for hospital admission due to stroke and sub-diagnoses in the period 1994-2003. Using hospital admission for all economically active men as the standard, the standardised hospitalisation ratios (SHR) were calculated, taking age and county into consideration.

RESULTS

There was a high SHR for stroke among all groups of professional drivers (SHR = 132; 95% CI 121-141). Among car, taxi, and van drivers the SHR was 157 (95% CI 132-189), among bus drivers it was 139 (95% CI 119-163), and among heavy truck and lorry drivers it was 124 (95% CI 113-136). The excess risk for all groups of professional drivers was highest for cerebrovascular infarction (SHR = 139; 95% CI 124-155) and lowest for non-traumatic intracranial haemorrhage (SHR = 113; 95% CI 96-133). The excess risks for all groups were significantly higher for cerebrovascular infarction than for non-traumatic intracranial haemorrhage (relative risk ratio (RRR) 1.23; 95% CI 1.01-1.51). The RRR of stroke among drivers in the metropolitan area compared to rural areas was 1.13 (95% CI 0.94-1.36). The RRR for stroke among car, taxi, and van drivers compared to drivers of heavy trucks and of lorries was 1.28 (95% CI 1.03-1.57).

CONCLUSION

All groups of professional drivers are at increased risk of stroke. The excess risk is more due to cerebral infarctions than to non-traumatic intracranial haemorrhage. The risk of stroke is higher among drivers carrying passengers than among drivers carrying goods.

Responses of the autonomic nervous system during periods of perceived high and low work stress in younger and older female teachers

The aim of this study was to examine the response of the autonomic nervous system in younger (mean age 31 yrs, n=14) and older (mean age 54 yrs, n=14) healthy female teachers during work periods of perceived high and low stress. In the younger participants, heart rate, cortisol excretion rate and psychosomatic symptoms were significantly higher during the high work stress period. The older participants experienced no decrease in their heart rate and cortisol excretion during the low stress period and they exhibited no significant decrease in blood pressure after the work in the evening during both periods. It may be concluded that the recovery from the stress in the older teachers was insufficient particularly in view of their elevated diastolic blood pressure during the low work stress period. Ergonomic and individually tailored measures in terms of work time control, specific relaxation techniques, and a part-time retirement may improve the stress management of older teachers.

Association of blood lead and tibia lead with blood pressure and hypertension in a community sample of older adults

Few studies have compared associations of blood lead and tibia lead with blood pressure and hypertension, and associations have differed in samples with occupational exposure compared with those with mainly environmental lead exposure. African Americans have been underrepresented in prior studies. The authors performed a cross-sectional analysis of 2001-2002 data from a community-based cohort in Baltimore, Maryland, of 964 men and women aged 50-70 years (40% African American, 55% White, 5% other race/ethnicity) to evaluate associations of blood lead and tibia lead with systolic and diastolic blood pressure and hypertension while adjusting for a large set of potential confounding variables. Blood lead was a strong and consistent predictor of both systolic and diastolic blood pressure in models adjusted and not adjusted for race/ethnicity and socioeconomic status. Tibia lead was associated with hypertension status before adjustment for race/ethnicity and socioeconomic status (p = 0.01); after such adjustment, the association was borderline significant (p = 0.09). Propensity score analysis suggested that standard regression analysis may have exaggerated the attenuation. These findings are discussed in the context of complex causal pathways. The data suggest that lead has an acute effect on blood pressure via recent dose and a chronic effect on hypertension risk via cumulative dose.

Job stress and cardiovascular risk factors in male workers

BACKGROUND

This study examined whether job stress (work demand and decision latitude) is associated with smoking, blood pressure, lipid level (total cholesterol, triglyceride, HDL cholesterol), and homocystein as risk factors for cardiovascular disease in Korean male workers.

METHODS

Study subjects of this study were recruited from a sample of 1,071 workers in 20 companies of W city and H counties, and they were grouped into four categories (high strain group, active group, passive group, and low strain group) based on the postulation of Karasek's Job Strain Model. Of them, we invited 160 male workers (40 people each subgroup) using a stratified sampling, and finally, 152 eligible participants were analyzed.

RESULTS

In multivariate analyses, we found that decision latitude was associated with cholesterol, triglyceride, and homocystein and that work demand was related to smoking and systolic blood pressure. Job strain (the combination of high work demand with low decision latitude) was significantly related to higher levels of homocystein after controlling for age, BMI, smoking, and social support at workplace.

CONCLUSIONS

These results indicate that job stress is associated with cardiovascular risk factors and might contribute to the development of cardiovascular disease. Some considerations for the future research were discussed.

Physical workload, ergonomic problems, and incidence of low back injury: a 7.5-year prospective study of San Francisco transit operators

BACKGROUND

The etiologic role of biomechanical factors for low back injury (LBI) needs to be confirmed in prospective studies that control for psychosocial factors.

METHODS

Complete baseline information on 1,233 vehicle operators was gathered during medical examinations and by questionnaire. First LBI during 7.5 years of follow-up was ascertained from insurance records. Hazard ratios and etiologic fractions were analyzed with Cox regression models stratified by injury severity and controlling for age, sex, height, weight, ethnicity, and biomechanical and psychosocial job factors. Severe LBI was defined as medically diagnosed postlaminectomy syndrome, spinal stenosis, herniated lumbar disc, sciatica, or spinal instability.

RESULTS

An exponential dose-response relationship was found between weekly driving hours and incidence of first LBI. Indicators of physical workload were more strongly associated with more severe low back injuries compared to less severe injuries. Rates of severe LBI increased 39% for every 10-hr increase in weekly driving (hazard ratio 1.39, 95% confidence interval 1.15-1.68). Higher risks of severe LBI were also found among operators performing heavy physical labor on cable cars (hazard ratio 2.76, 95% confidence intervals 1.24-6.14) or reporting more ergonomic problems at baseline (HR for upper quartile 1.65 (95% confidence interval 1.08-2.50). Estimates of etiologic fractions suggest that reduction of ergonomic problems to the low level currently experienced by 25% of drivers would result in a 19% reduction of severe LBI among all drivers. A change from full- (more than 30 hr) to part-time driving (20-30 hr) could reduce the number of severe LBI by 59%, although this gain would be reduced to 28% at the company level if injuries expected among additional employees, hired to maintain full service are included.

CONCLUSIONS

Duration of professional driving and ergonomic problems are independent and preventable risk factors for LBI even after adjustment for psychosocial factors.

Increases in job strain are associated with incident hypertension in the CARDIA Study

BACKGROUND

Job strain, defined as high job demands and low decision latitude, has been associated with increased blood pressure levels in some studies, but most of these studies have been cross-sectional.

PURPOSE

We sought to determine whether changes in job strain during young adulthood were associated with the development of hypertension, using the Coronary Artery Risk Development in Young Adults cohort.

METHODS

A total of 3,200 employed, initially normotensive participants, aged 20 to 32 in 1987-1988, were followed for 8 years; the Job Content Questionnaire was completed twice: initially and 8 years later. Hypertension at follow-up was defined as systolic blood pressure (SBP) of 160 or higher and diastolic blood pressure of 95 mmHg or higher, or reporting being on antihypertensive medication.

RESULTS

Job strain (based on job demands above the median and decision latitude below the median of the sample) was associated with hypertension incidence (ps <.05) for the entire cohort and among White women and men. Adjustment for baseline SBP, education, body mass index (BMI), change in BMI, and age did not alter these relations. The ratio of increasing demands relative to decreasing decision latitude was also associated with greater incidence of hypertension in the entire cohort in the multivariate model (odds ratio = 2.06, 95% confidence interval = 1.01-4.26).

CONCLUSIONS

An increase in job strain is associated with incident hypertension, particularly among Whites.

Occupational stressors and hypertension: a multi-method study using observer-based job analysis and self-reports in urban transit operators

This multi-method study aimed to disentangle objective and subjective components of job stressors and determine the role of each for hypertension risk. Because research on job stressors and hypertension has been exclusively based on self-reports of stressors, the tendency of some individuals to use denial and repressive coping might be responsible for the inconclusive results in previous studies. Stressor measures with different degrees of objectivity were contrasted, including (1) an observer-based measure of stressors (job barriers, time pressure) obtained from experts, (2) self-reported frequency and appraised intensity of job problems and time pressures averaged per workplace (group level), (3) self-reported frequency of job problems and time pressures at the individual level, and (4) self-reported appraised intensity of job problems and time pressures at the individual level. The sample consisted of 274 transit operators working on 27 different transit lines and four different vehicle types. Objective stressors (job barriers and time pressure) were each significantly associated with hypertension (casual blood pressure readings and/or currently taking anti-hypertensive medication) after adjustment for age, gender and seniority. Self-reported stressors at the individual level were positively but not significantly associated with hypertension. At the group level, only appraisal of job problems significantly predicted hypertension. In a composite regression model, both observer-based job barriers and self-reported intensity of job problems were independently and significantly associated with hypertension. Associations between self-reported job problems (individual level) and hypertension were dependent on the level of objective stressors. When observer-based stressor level was low, the association between self-reported frequency of stressors and hypertension was high. When the observer-based stressor level was high the association was inverse; this might be indicative of denial of stress or alexithymia. We feel that multi-method studies are useful for disentangling the relations between objective and subjective stress and hypertension.

Persistent insomnia is a predictor of hypertension in Japanese male workers

Insomnia is one of the most common complaints at worksites, as well as in the general population. This study aims to assess the effect of insomnia on the development of hypertension in Japanese male workers. Using the annual health examination database of a Japanese telecommunication company, eligible middle-aged male participants in the 1994 health examination were followed up until 1998 or the development of hypertension (either initiation of antihypertensive therapy or a systolic blood pressure > or = 140 mmHg and/or a diastolic blood pressure > or = 90 mmHg). The effect of difficulty initiating sleep (DIS) was assessed with a DIS dataset (n=4,794), which included non-DIS (n=4,602) and persistent-DIS (n=192) subjects. That of difficulty maintaining sleep (DMS) was assessed with a DMS dataset (n=4,443), which included non-DMS (n=4,157) and persistent-DMS (n=286) subjects. The incidence of hypertension among persistent-DIS (40.1%; 130.7 per 1,000 person-yr) was significantly higher than that among non-DIS (30.6%; 89.9 per 1,000 person-yr). The incidence of hypertension among persistent-DMS (42.3%; 136.7 per 1,000 person-yr) was significantly higher than that among non-DMS (30.7%; 90.8 per 1,000 person-yr). After adjusting for potential confounding factors (i.e. age, body mass index, smoking, alcohol drinking, and job stress), persistent complaints of DIS and DMS were significantly associated with an increased risk of hypertension (OR=1.96; 95%CI: 1.42-2.70 and OR=1.88; 95%CI: 1.45-2.45, respectively). Persistent insomnia may be a useful predictor of hypertension in Japanese male workers.

Work-related psychosocial factors and carotid atherosclerosis

BACKGROUND

In order to better understand the role of work environment in the earlier stages of the cardiovascular disease process, we wanted to investigate the influence of work-related psychosocial factors on preclinical atherosclerosis.

METHODS

Cross-sectional data was used to examine the association between psychological job demands, job decision latitude, and carotid atherosclerosis in 2658 vocationally-active Swedish men and women, ages 46-65, from the general population. Odds ratios of carotid plaque prevalence and carotid artery intima-media thickness (IMT), determined by B-mode ultrasound, were estimated across combinations of job demands and decision latitude.

RESULTS

Women in job situations with high demands and low decision latitude ('job strain') showed a high plaque prevalence odds (odds ratio [OR] = 1.68, 95% CI: 1.14, 2.48), and a thicker IMT in the carotid bifurcation area (mean difference: 0.15 mm, 95% CI: 0.07, 0.23) compared with women in job situations with low demands and high decision latitude ('relaxed'). Adjustment for covariates only slightly reduced the magnitude of these associations. No such associations were seen in men. However, women in job situations with high demands and high decision latitude ('active') also showed high odds for carotid plaque, and a thicker IMT in the carotid bifurcation, compared with women in 'relaxed' job situations. In men, those in 'active' job situations had a low carotid plaque prevalence odds, while IMT in the carotid bifurcation did not differ from those in 'relaxed' job situations. Results showed only weak associations with IMT in the common carotid artery (CCA) in both men and women.

CONCLUSION

The specific hypothesis that high job demands interact synergistically with low decision latitude in the development of carotid atherosclerosis could not be supported in this study, neither in men nor in women. Instead a more complex pattern of interaction between job demands and decision latitude was shown.

A prospective study of job strain and coronary heart disease in US women

BACKGROUND

Previous studies of job strain and coronary heart disease (CHD) in men have established job strain as a predictor of CHD risk. Despite the wealth of convincing evidence in men for an association between job strain and CHD, data in women remain sparse.

METHODS

We prospectively evaluated the relation between job strain and CHD risk in the Nurses' Health Study. In this analysis, we followed a sample of 35 038 US female nurses aged 46-71 years, who completed questions about job strain in 1992 and who were free of diagnosed CHD, stroke, and cancer at baseline. The main outcome measure was the incidence of CHD occurring between baseline (1 June 1992) and 31 May 1996.

RESULTS

During 4 years of follow-up, we documented 146 incident cases of CHD (108 non-fatal cases of myocardial infarction and 38 CHD deaths). No evidence was found for a relationship between job strain and risk of CHD. In multivariate analyses controlling for age, smoking, alcohol intake, body mass index, history of hypertension, diabetes mellitus, and other covariates, women in high strain jobs did not have an increased risk of CHD (relative risk [RR] = 0.71, 95% CI: 0.42-1.19) compared with women in low strain jobs. Neither women in passive jobs (RR = 1.08, 95% CI: 0.69-1.68) nor those in active jobs (RR = 0.91, 95% CI: 0.54-1.53) had an increased risk of CHD.

CONCLUSIONS

Job strain was not related to an increase in the incidence of CHD in the present cohort of nurses.

Job characteristics and blood coagulation factors in Korean male workers

This study examined the possible relationship between Karasek's job strain model and blood coagulation factors VII and VIII as risk factors for cardiovascular disease in Korean male workers. Based on the postulation of the model, we invited 160 male workers (40 people each subgroup) using a stratified sampling from the base population (n = 1071). In univariate analyses, decision latitude was negatively related to blood coagulation factors VII and VIII. Work demand was positively related to coagulation factor VIII, but not to factor VII. Hierarchical multiple regression analyses showed that job strain was associated with blood coagulation factor VIII after controlling for smoking, blood pressure, total cholesterol, and HDL cholesterol. These results indicate that job characteristics may be related to blood coagulation, and contribute to the development of cardiovascular disease with other classical risk factors.

Association between job strain and prevalence of hypertension: a cross sectional analysis in a Japanese working population with a wide range of occupations: the Jichi Medical School cohort study

OBJECTIVES

To explore the association between the prevalence of hypertension in a Japanese working population and job strain (a combination of low control over work and high psychological demands), and to estimate this association in different sociodemographic strata.

METHODS

From a multicentre community based cohort study of Japanese people, sex specific cross sectional analyses were performed on 3187 men and 3400 women under 65 years of age, all of whom were actively engaged in various occupations throughout Japan. The baseline period was 1992-95 [corrected]. The association between job characteristics--measured with a Japanese version of the Karasek demand-control questionnaire--and the prevalence of hypertension defined by blood pressure and from clinical diagnoses were examined. Adjustments were made for possible confounders. The analyses were repeated for stratified categories of occupational class, educational attainment, and age group.

RESULTS

In men, the level of job strain (the ratio of psychological job demands to job control) correlated with the prevalence of hypertension. In a multiple logistic regression model, job strain was significantly related to hypertension (odds ratio 1.18; 95% confidence interval 1.05 to 1.32), after adjustment for age, employment (white collar v blue collar), marital status, family history of hypertension, cigarette smoking, alcohol intake, physical activity, and body mass index. The stratified analyses showed significant excess risks in the subordinate groups compared with managers, blue collar workers, less educated workers, and the older age groups. This association was not significant in women. Multiple linear regression analyses, with systolic and diastolic blood pressures as dependent variables, did not show any significant association.

CONCLUSIONS

The findings provided limited proof that job strain is related to hypertension in Japanese working men. Older men in a lower social class may be more vulnerable to the hypertensive effects of job strain.

Psychologic factors as precursors to hypertension

The possibility that certain psychologic factors lead to hypertension has been considered by many investigators over the past 60 years, but prospective studies with suitable methods to evaluate this hypothesis were not available for analysis until the 1990s. There are now five large longitudinal studies demonstrating a relation between symptoms of anxiety or depression and subsequent hypertension incidence. Anger expression, long considered a major psychologic factor in hypertension, has been studied less extensively, and the findings to date are less consistent. While some evidence supports the biological plausibility of psychologic factors as risk factors for hypertension, biobehavioral mechanisms explaining the relationship have not been adequately explored. The results of these recent studies may lead to new intervention trials specifically selecting hypertensive patients with anxiety or depression for treatment with stress reduction or other appropriate psychologic therapies. Such studies would further contribute to the evaluation of anxiety and depression as risk factors for hypertension.

Epidemiology of risk factors for hypertension: implications for prevention and therapy

We review the present knowledge of risk factors for arterial hypertension. Both genetic and environmental factors as well as their interaction and biological plausibility are reviewed. Recent data confirm that the interaction of genetics with multiple environmental risk factors explains the high prevalence of hypertension in the industrialised countries. The most important modifiable environmental risk factors are high salt intake, alcohol intake, obesity and low physical activity. The role of stress in the aetiology of high blood pressure is still under investigation, but recent clinical experimental and epidemiological data have shed light on how stress could be related to hypertension. The implications for prevention and treatment are discussed both at the population and individual levels. The population approach involves a public health policy aiming at modification of the major risk factors. The individual approach involves nonpharmacological measures to prevent the development of hypertension and to treat high normal blood pressure and mild hypertension with no additional cardiovascular risk factors. Pharmacological treatment of hypertension in most individuals should use agents that have been proven to be effective in randomised controlled trials with 'hard' endpoints such as cardiovascular and cerebrovascular morbidity and mortality.

Job strain and biological coronary risk factors: A cross-sectional study of male and female workers in a japanese rural district

To investigate the association between job strain and biological coronary risk factors, a demand-control questionnaire was applied to 138 male (mean age 51.5) and 166 female (50.8) workers in Japanese rural town. In Model I, workers rated as both above the median on demands and below the median on control were defined as a strain group and compared to the rest. In Model II, the effect of a multiplicative term of demands by control was tested once the component main effects were controlled. In both models, possible confounders were controlled. Men in the strain group had higher blood glucose than did the others (Model 1), and the multiplicative term was significantly associated with diastolic blood pressure in men and with Lipoprotein(a) in women (Model II). The results suggest that the demand-control model predicts coronary risk factors in Japanese rural workers, and the associations are different between genders.

Gender, work roles and psychosocial work characteristics as determinants of health

This paper aims to identify gender similarities and differences in psychosocial work characteristics for those in and out of paid employment, to inform research on possible health-related effects. Specifically five questions are addressed: do women report poorer work characteristics than men; are gender differences related to specific characteristics; do work characteristics differ between full- and part-time women workers and between those in paid and unpaid work; are socio-economic gradients in work characteristics similar for men and women; and, if there are gradients, do they differ between women in paid and unpaid work? Analyses are based on the 33 year follow-up of the 1958 British birth cohort. Four psychosocial work characteristics were examined: learning opportunities, monotony, pace of work, and flexibility of breaks. Women reported more negative work characteristics than men, primarily because of differences in learning opportunities (26% lacked opportunity compared with 13% of men) and monotonous work (47 and 31% respectively). Women in full-time employment reported fewer negative characteristics (27%) than part-time (39%) or home-workers (36%). Home-workers had fewer opportunities for learning (36%) and greater monotony (49%) than paid workers (21 and 22% respectively), however fewer home-workers reported inability to control the work pace (11% compared to 23%) and inflexibility of breaks (21% compared to 47%). Socio-economic gradients in work characteristics were similar among men and women, except for flexibility of break times. A socio-economic gradient in work characteristics was found for full- and part-time workers, but not among home-workers. Differences in self reported health were also examined: a social gradient was found for all employment status groups, being strongest for home-workers despite the absence of a gradient in negative work characteristics. In conclusion, these marked gender differences in psychosocial work characteristics need to be considered in future research on work and health.

The acceptable risk of driving after myocardial infarction: are bus drivers a special case?

BACKGROUND

Bus drivers frequently encounter difficulty in returning to their former employment after recovery from myocardial infarction. The risk that a recurrence of myocardial infarction may cause a personal-injury accident is analyzed.

METHODS

The Cumulative Medical Index and Current Contents was searched systematically from 1980 to date, accepting papers irrespective of language. Relevant earlier material was drawn from the author's published reviews on bus driving and myocardial infarction and vehicle accidents. One hundred twenty-three articles were included in the database, of which 110 were used in the review.

RESULTS

The risk of a personal injury accident or fatality from a sudden cardiovascular incident is calculated as the product of typical driving time per day (Td = 0.167), vehicle characteristics (V) (a low factor of 0.167 for an urban bus because of slow speed and use of reserved curb lanes), the risk of recurrence of a sudden cardiovascular incident (SCI) (.015, somewhat greater in bus drivers than in the general population), and the risk that such an incident will cause a personal-injury accident (Ac) (at 0.005, probably lower than in the general population because of low vehicle speeds and the bus driver's experience in defensive driving).

CONCLUSIONS

The overall risk is 0.00002, 1 in 50,000 driver-years, is lower than accepted for passenger-car operators, and only slightly greater than for the older symptom-free adult. Bus drivers who meet the current standards of the Canadian Cardiovascular Society should be encouraged to return to their former employment.

African American women in the workplace: relationships between job conditions, racial bias at work, and perceived job quality

Although studies have described work processes among employed African American women, few have examined the influence of these processes on job outcomes. This study examined relationships between African American women's exposure to a range of occupational stressors, including two types of racial bias--institutional discrimination and interpersonal prejudice--and their evaluations of job quality. Findings indicated that institutional discrimination and interpersonal prejudice were more important predictors of job quality among these women than were other occupational stressors such as low task variety and decision authority, heavy workloads, and poor supervision. Racial bias in the workplace was most likely to be reported by workers in predominantly white work settings. In addition, Black women who worked in service, semiskilled, and unskilled occupations reported significantly more institutional discrimination, but not more interpersonal prejudice, than did women in professional, managerial, and technical occupations or those in sales and clerical occupations.

Physical workload and ergonomic factors associated with prevalence of back and neck pain in urban transit operators

STUDY DESIGN

Back and neck pain was studied cross-sectionally in 1,449 urban transit drivers by linking medical data, self-reported ergonomic factors, and company records on job history.

OBJECTIVES

The goal was to examine the relation between physical workload, ergonomic factors, and the prevalence of back and neck pain.

SUMMARY OF BACKGROUND DATA

Researchers, to date, have not found an independent effect of ergonomic factors on back and neck pain while accounting for the effects of past and current physical workload.

METHODS

Self-reported ergonomic factors, vehicle type, physical workload (measured as duration of driving), height, weight, age, and gender were analyzed in relation to back and neck pain, using multivariable logistic regression models.

RESULTS

Physical workload showed a positive dose-response relation with back and neck pain after controlling for vehicle type, height, weight, age, and gender. The odds ratio for 10 years of driving was 3.43. Additional adjustment for ergonomic factors decreased this odds ratio to 2.55. Six out of seven ergonomic factors were significantly related to the prevalence of back and neck pain after adjustment for age, gender, height, weight, and physical workload. Problems with adjusting the seat had the largest effect (odds ratio = 3.52). Women had back and neck pain twice as frequently as men.

CONCLUSION

The results support the hypothesis of a causal role of physical workload for the development of back and neck pain. Ergonomic factors partially mediated the risk of back and neck pain associated with driving, suggesting a potential for prevention of back and neck pain by ergonomic redesign of transit vehicles. Elevated risks for back and neck pain for female drivers were not explained by anthropometric and ergonomic factors.

Job strain and blood pressure in African Americans: the Pitt County Study

OBJECTIVES

This report examined whether job strain (or its components, decision latitude and job demands) was associated with elevated blood pressure levels in a community-based sample of 726 African-American adults.

METHODS

Blood-pressure, anthropometric, behavioral, demographic, and psychosocial data were collected for the current cross-sectional analyses during home interviews conducted for the second wave (1993) of the Pitt County Study (North Carolina), a prospective cohort study of hypertension among African Americans.

RESULTS

Job strain was not associated with blood pressure among men or women in this study. However, men in the 80th percentile of decision latitude had more than a 50% decrease in the prevalence of hypertension compared with men in the 20th percentile (odds ratio = .46, 95% confidence interval = .22, .96).

CONCLUSIONS

These results indicate that decision latitude may be important for hypertension risk among African-American men. More research is needed on African Americans to determine why job strain and its two component variables differ in their associations with blood pressure for men and women.

Employment, job strain, and preterm delivery among women in North Carolina

OBJECTIVES

A population-based case-control study was conducted in central North Carolina to assess the relationship between occupational stress and preterm delivery.

METHODS

Four hundred twenty-one women delivering infants before 37 weeks' gestation and 612 women delivering infants at term were interviewed a median of 6 months after delivery. Exposure information was collected for all jobs held for at least 1 month during pregnancy.

RESULTS

Work in a "high strain" job (i.e., high demand and low control) was not associated with increased risk of preterm delivery compared with work in "low strain" jobs (all other combinations of job demand and control). Narrowing the exposure window to the third trimester did not modify the results. However, women who worked at a high-strain job full-time (odds ratio [OR] = 1.4, 95% confidence interval [CI] = 0.9, 2.0) or for 30 or more weeks (OR = 1.4, CI = 1.0, 2.2) had a modestly increased risk. Several analyses suggested that Black women were at greater risk from job strain than White women.

CONCLUSIONS

This study suggests that chronic exposure during pregnancy to work characterized by high demand and low control may be modestly associated with preterm delivery.

Health psychology: what is an unhealthy environment and how does it get under the skin?

This review explores the role of environments in creating chronic and acute health disorders. A general framework for studying the nesting of social environments and the multiple pathways by which environmental factors may adversely affect health is offered. Treating socioeconomic status (SES) and race as contextual factors, we examine characteristics of the environments of community, work, family, and peer interaction for predictors of positive and adverse health outcomes across the lifespan. We consider chronic stress/allostatic load, mental distress, coping skills and resources, and health habits and behaviors as classes of mechanisms that address how unhealthy environments get "under the skin," to create health disorders. Across multiple environments, unhealthy environments are those that threaten safety, that undermine the creation of social ties, and that are conflictual, abusive, or violent. A healthy environment, in contrast, provides safety, opportunities for social integration, and the ability to predict and/or control aspects of that environment.