Psychological variables in hypertension: relationship to casual or ambulatory blood pressure in men.

OBJECTIVE: The evidence linking hypertension with personality or psychological characteristics, such as anger, anxiety, or depression, remains equivocal. This may be due in part to limitations of personality theory, confounding by awareness of hypertension, and/or inherent difficulties in measuring blood pressure. This study was designed to investigate the association between mild hypertension as defined by both ambulatory and casual (clinic) blood pressure measurements and various measures of personality and psychological characteristics. METHODS: We examined this association in a population-based sample of 283 men between the ages of 30 and 60 years from eight work sites in New York City, using an ambulatory blood pressure monitor and controlling for age, race/ethnicity, and body mass index. RESULTS: We found no consistent difference between participants with mild hypertension and those with normal blood pressure on any of the psychological variables assessed, including Type A behavior pattern, state and trait anger, anger expression, anxiety, symptoms of psychological distress, locus of control, or attributional style. Results were not due to the use of antihypertensive medication by some of the participants with hypertension nor to the dichotomization of blood pressure into those with and without mild hypertension. This contrasts with previous findings from this study showing a sizable association of ambulatory blood pressure and hypertension with job strain (a situational measure), age, and body mass index. CONCLUSIONS: These null results suggest that situational, biological, and perhaps behavioral factors are the primary determinants of mild hypertension and that the predictive significance of psychological or dispositional factors is low or negligible in those without overt cardiovascular disease.

Effect of body weight changes on changes in ambulatory and standardized non-physician blood pressures over three years.

PURPOSE: This study examines the relationship of changes in body mass index (BMI) to changes in measures of both casual and ambulatory blood pressures over three years. METHODS: In this prospective study of men aged 30-60 years, a cohort of 198 participants was followed for three years. Height, weight, demographic characteristics, and casual and ambulatory measures of blood pressure (BP) were obtained at baseline and 3-year follow-up. RESULTS: Change in BMI was significantly associated with change in all ambulatory (awake, work, home, and sleep) and casual systolic and diastolic blood pressures. After controlling for age and race/ethnicity, the association remained significant for nine of the twelve BP change measures. Further tests show that the effect of a change in BMI on BP change does not vary across the six systolic blood pressures or across the six diastolic measures. An average-height man gaining 5 kg (11 pounds) typically exhibited a 2.5 mm Hg increase in systolic and a 1.8 mm Hg increase in diastolic casual and ambulatory BPs. There is no evidence that changes in BP were associated with age, race/ethnicity (blacks vs. Hispanics vs. whites), or the average of the baseline and follow-up levels of BMI. In addition, the impact of weight gain is similar in magnitude, but in the opposite direction, to that of weight loss. CONCLUSIONS: Changes in BMI over three years predict changes in ambulatory and standardized non-physician BPs. These changes in BP are not related to average BMI level or age.

A longitudinal study of job strain and ambulatory blood pressure: results from a three-year follow-up.

OBJECTIVE: This study was conducted to investigate the hypothesis that exposure to "job strain" is related to increased ambulatory blood pressure (ABP). METHOD: Participants were 195 men who wore an ABP monitor for 24 hours on two occasions 3 years apart. Job strain status, evaluated at each assessment, was used to identify four groups: those not having job strain at either assessment (N = 138), those having job strain at both times (N = 15), and two crossover groups. Regression analysis was used to examine the cross-sectional associations of ABP with job strain, controlling for other known risk factors. Repeated-measures analysis of variance was used to examine the association of ABP change with the category of job strain change. RESULTS: The cross-sectional analysis of the Time 2 data yielded almost identical, highly significant effects of job strain on ABP as was shown in our previously published Time 1 analysis. Those in high strain jobs at both times had systolic/diastolic ABPs at work and at home that were, on average, 11/7 mm Hg higher than those with no job strain at both times; the crossover groups had intermediate levels of ABP. The longitudinal analysis showed that those with a high strain job at Time 1, but not at Time 2, had a significant decrease in work and home ABP of approximately 5/3 mm Hg. CONCLUSIONS: The previously reported cross-sectional association between job strain and ABP was replicated at follow-up. The group repeatedly exposed to job strain had higher levels of ABP at Time 2 than either crossover group. Furthermore, change in job strain status partially predicted change in ABP. These results provide new evidence supporting the hypothesis that job strain is an occupational risk factor in the etiology of essential hypertension.

Job strain and health behaviors: results of a prospective study.

PURPOSE: To assess the association between job demands, job decision latitude, and job strain (defined by Karasek as a combination of high demands and low decision latitude) and cardiovascular disease-related health behaviors such as cigarette smoking, alcohol use, lack of exercise, and overweight. DESIGN: Cross-sectional and prospective. SETTING: Nine New York City public and private sector worksites. SUBJECTS: Two hundred eighty-five male employees, aged 30 to 60, in a wide variety of white-collar and blue-collar job titles. MEASURES: Medical examinations and surveys, which included demographic, health behavior, and job characteristics data. RESULTS: Prospectively, among 189 men, increase in job decision latitude over 3 years was associated with decrease in cigarette smoking, by analysis of covariance, controlling for age, race, education, marital status, and number of children at home (F (8, 180) = 4.37, p = .005). The largest increase in latitude occurred among the 13 men who quit smoking. However, change in job characteristics was not associated with change in overweight or alcohol use. Cross-sectional analyses did not produce consistent associations. CONCLUSIONS: The effectiveness of smoking cessation may be aided by modification of structural features of the work environment, such as job decision latitude. This study is limited by the small number of subjects who were engaged in high risk behaviors.

Environmental influences on blood pressure and the role of job strain.

OBJECTIVE: To review the evidence that human essential hypertension is at least in part the result of the influence of psychosocial factors, with special reference to occupational stress (job strain). FINDINGS: The prevalence of human hypertension is related to social factors such as urbanization and education. Several studies, conducted both experimentally in animals and observationally in people, have suggested that chronic social conflict is associated with higher blood pressure. Ambulatory monitoring has shown that most people have their highest pressures during working hours. Occupational stress can be evaluated as job strain, which is a combination of high demands at work with low decision latitude or control. Job strain has been related to coronary heart disease, and a number of studies have shown that it is also associated with higher ambulatory blood pressures, both cross-sectionally and prospectively, in men but not in women. Men in high strain jobs also show an increased left ventricular mass. Laboratory studies of blood pressure reactivity to stressful tasks support the concept of loss of control being associated with higher pressures. CONCLUSIONS: Job strain is a risk factor for hypertension in men, but not in women.

Association between ambulatory blood pressure and alternative formulations of job strain.

OBJECTIVES: The goal of the study was to determine whether alternative formulations of Karasek & Theorell's job-strain construct are associated with ambulatory blood pressure and the risk of hypertension. METHODS: Full-time male employees (N = 262) in eight worksites completed a casual blood pressure screening, medical examinations, and questionnaires and wore an ambulatory blood pressure monitor for 24 h on a workday. Cases of hypertension were ascertained from casual blood pressure readings for a case-referent analysis. A cross-sectional analysis was also conducted, ambulatory (continuous) blood pressure measurements being used as the outcome. RESULTS: All formulations of job strain exhibited significant associations with systolic blood pressure at work and home, but not with diastolic blood pressure. Employees experiencing job strain had a systolic blood pressure that was 6.7 mm Hg (approximately 0.89 kPa) higher and a diastolic blood pressure that was 2.7 mm Hg (approximately 0.36 kPa) higher at work than other employees, and the odds of hypertension were increased [odds ratio (OR) 2.9, 95% confidence interval (95% CI) 1.3-6.6]. Using national means for decision latitude and demands to define job strain increased the systolic and diastolic blood pressure associations to 11.5 mm Hg (approximately 1.53 kPa) and 4.1 mm Hg (approximately 0.54 kPa), respectively. Adding organizational influence to the task-level decision latitude variable produced a stronger association for hypertension with job strain (OR 3.7, 95% CI 1.6-8.5). Adding social support to the job-strain model also slightly increased the hypertension risk. CONCLUSIONS: The impact of job strain, at least on systolic blood pressure, is consistent and robust across alternative formulations, more restrictive cut points tending to produce stronger effects.

The patterning of psychological attributes and distress by "job strain" and social support in a sample of working men.

As a test of the "job strain" (job demands-control) model, 297 healthy men aged 30-60 were recruited at eight New York City worksites. The association among job demands and control, social support, and psychological outcomes was tested using both ANCOVA and moderated multiple regression, controlling for demographic variables. The job strain model was supported by various psychological outcome measures, with workers in "active" jobs reporting the highest level of Type A behavior, job involvement, and positive attributional style, workers in "low-strain" jobs reporting the lowest job dissatisfaction and trait anxiety, workers in "passive" jobs reporting the most external locus of control and trait anxiety, and workers in "high-strain" jobs reporting the highest job dissatisfaction. Low social support was associated with greater symptomatology, and a significant three-way interaction (demands x control x support) for job dissatisfaction was observed. While selection of subjects into jobs may partially explain these findings, the results support the hypothesis that working conditions influence psychological attributes and distress.

Relation between job strain, alcohol, and ambulatory blood pressure.

"Job strain" (defined as high psychological demands and low decision latitude on the job) has been previously reported to be associated with increased risk of hypertension and increased left ventricular mass index (LVMI) in a case-control study of healthy employed men, aged 30-60 years, without evidence of coronary heart disease. We hypothesized that job strain would be associated with increased ambulatory blood pressure (AmBP). A total of 264 men at eight work sites wore an AmBP monitor for 24 hours on a working day. In an analysis of covariance model, job strain was associated with an increase in systolic AmBP of 6.8 mm Hg (p = 0.002) and diastolic AmBP of 2.8 mm Hg at work (p = 0.03) after adjusting for age, race, body mass index, Type A behavior, alcohol behavior, smoking, work site, 24-hour urine sodium, education, and physical demand level of the job. Alcohol use also had a significant effect on AmBP. However, among subjects not in high-strain jobs, alcohol had no apparent effect on AmBP at work. Instead, alcohol use and job strain interacted such that workers in high-strain jobs who drank regularly had significantly higher systolic AmBP at work (p = 0.007). Among the other risk factors, only age, body mass index, and smoking had significant effects on AmBP. Job strain also had significant effects on AmBP at home and during sleep as well as on LVMI.(ABSTRACT TRUNCATED AT 250 WORDS)

The impact of anticipation of job loss on psychological distress and worksite blood pressure.

The impact of occupational stressful life events on psychological distress and blood pressure was examined among employees of a major New York City brokerage firm undergoing massive layoffs. One hundred thirty-nine employees of the firm, who had participated in a blood pressure screening in 1986, were rescreened during the period of layoffs within their company in 1989. About two-thirds of the 139 employees reported being "somewhat" or "very" anxious or upset in 1989 during the period of layoffs, and psychological distress was significantly elevated among those employees reporting possible or definite layoff or job change and/or difficulty in obtaining a comparable job. However, we found no increase in overall blood pressure level, and no effect of anticipation of job loss on 1989 blood pressure when controlling for 1986 blood pressure level, age, body mass index, work hours, and other demographic variables. On the other hand, employment in a department sold to another employer on the day of screening, as well as employment in a clerical job title, were both associated with significant increases in diastolic blood pressure of about 5 mm Hg.

Can behavioural factors produce a sustained elevation of blood pressure? Some observations and a hypothesis.

A major problem confronting behavioural theories of hypertension, such as the reactivity hypothesis, is that stress is likely to be intermittent, whereas the early stages of hypertension appear to be characterized by an increase in the tonic level of blood pressure and sympathetic activity. Furthermore, intermittent sympathetic arousal (e.g. exercise, thigh-cuff compression) does not necessarily raise tonic blood pressure. A worksite-based study of occupational stress has indicated that people in high-stress jobs have increased blood pressure throughout the day and night, which is at least consistent with a behaviourally mediated resetting of the tonic blood pressure level. There is evidence that adrenaline is preferentially released in response to behavioural stresses. According to the 'adrenaline hypothesis', adrenaline can raise tonic blood pressure while noradrenaline does not. We therefore propose that the different long-term effects of behavioural stress and exercise on blood pressure can be explained by their differing effects on catecholamine release.

The role of behavioral factors in white coat and sustained hypertension.

Studies using ambulatory monitoring of blood pressure have indicated that patients with persistently elevated clinic pressures may be subdivided into two groups, those in whom ambulatory pressure is also elevated (persistent hypertension), and those in whom it is normal (white coat hypertension). The role of behavioral factors in contributing to these two types is discussed. Studies of white coat hypertension suggest that it is not characterized by any generalized physiological abnormality, and that target-organ damage is mild and the prognosis relatively benign. It may represent a conditioned response to the physician. Behavioral factors can significantly influence the diurnal profile of blood pressure, as shown by a comparison of ambulatory pressures recorded on working and non-working days, and in women who experience varying levels of occupational and domestic stress. The role of behavioral factors in the development of sustained hypertension (defined as an upward resetting of the diurnal profile), however, is much less clear. A cross-sectional study of normotensive and hypertensive men has shown that men employed in high-strain jobs are more likely to show a sustained elevation of blood pressure.

The effect of work environments on blood pressure: evidence from seven New York organizations.

The prevalence of hypertension defined according to National Health and Nutrition Examination Survey II (NHANES II) criteria (140/90 mmHg and/or taking antihypertensive medication) was analyzed cross-sectionally at seven worksites in New York City (n = 4274; 2616 men and 1648 women), in order to assess whether exposure to different work environments and occupations contributes to blood pressure variation. The prevalence of hypertension across worksites was 26% among men and 12% among women. Blood pressure was significantly different across worksites even after controlling for known risk factors using analysis of covariance. Of the variation in systolic pressure, 34% was predicted significantly by eight variables; after adjusting for upper-arm circumference, age and body mass index, higher pressures were associated with worksite differences (9.0 mmHg), being male (7.2 mmHg), lacking a high-school education (4.3 mmHg), having a clerical occupation (2.9 mmHg) and being unmarried (1.8 mmHg). Similar results for diastolic pressure suggest that researchers should consider worksite and job characteristics as important predictors of blood pressure differences in working populations.

Body fat and its distribution in relation to casual and ambulatory blood pressure.

This study was undertaken to evaluate the associations of body fat and its distribution with casual and ambulatory blood pressure in nonobese men. One hundred and thirty-five normotensive or mildly hypertensive (but untreated) men employed at three work sites were studied. Casual blood pressure was measured at the work site at initial screening and on a second occasion by a nurse. Ambulatory blood pressure was measured noninvasively for 24 hours on a workday and analyzed as work, home, and sleep blood pressure measurements. Anthropometric measurements included height, weight, and waist and hip circumferences. Blood pressure was highest while at work; home blood pressure was higher than screening blood pressure or nurse blood pressure, and sleep blood pressure was lowest. Weight and both waist and hip circumferences (but not their ratio) were all significantly correlated with screening, nurse, and sleep blood pressures but not with work or home blood pressures. Stepwise regression analysis showed that waist circumference was the best overall predictor of blood pressure. We suggest that in situations where blood pressure is the dependent variable, correlations with other variables may be closest for "basal" measures of blood pressure and may be obscured by the effects of daily activities on blood pressure.