Cardiovascular effects of social support in the work place: twenty-four-hour ECG monitoring of men and women

Psychosocial work characteristics, such as work demand, work control, and social support at work, have been shown to be related to the development of coronary heart disease in epidemiological studies. However, the mechanisms which mediate the social and psychological effects on the cardiovascular system are not known. We have studied the direct cardiovascular effects of psychosocial work environment characteristics in 148 working men and women, representing seven different occupational groups (physicians, teachers, musicians, policemen, train engineers, prison personnel, and saw mill workers). Besides standardized measures of work demand, work control, and social support, ambulatory 24-hour monitoring of electrocardiograms in the customary work and home environment was performed. Systolic and diastolic blood pressure were measured as well as other standard physiologic risk factors for coronary heart disease. Mean heart rates were found to be significantly higher in persons reporting low social support at work. This effect was maintained during working hours as well as during leisure time and rest. Of the other related physiologic risk factors, systolic, but not diastolic blood pressure was found to be higher in persons reporting low social support. Smoking, alcohol consumption and relative body mass index were not related to social support at work. Controlling for age, sex and physical strain at work, strengthened the association of low social support with elevated heart rates.     

Caffeine affects cardiovascular and neuroendocrine activation at work and home

OBJECTIVE: This study investigated the effects of moderate doses of caffeine on ambulatory blood pressure and heart rate, urinary excretion of epinephrine, norepinephrine, and cortisol, and subjective measures of stress during normal activities at work and at home in the evening. METHODS: Healthy, nonsmoking, habitual coffee drinkers (N = 47) participated in 3 days of ambulatory study. After a day of ad lib caffeine consumption, caffeine (500 mg) and placebo were administered double-blind in counter-balanced order on separate workdays. Ambulatory blood pressure and heart rate were monitored from the start of the workday until bedtime. Urinary excretion of catecholamines and cortisol was assessed during the workday and evening. RESULTS: Caffeine administration significantly raised average ambulatory blood pressure during the workday and evening by 4/3 mm Hg and reduced average heart rate by 2 bpm. Caffeine also increased by 32% the levels of free epinephrine excreted during the workday and the evening. In addition, caffeine amplified the increases in blood pressure and heart rate associated with higher levels of self-reported stress during the activities of the day. Effects were undiminished through the evening until bedtime. CONCLUSIONS: Caffeine has significant hemodynamic and humoral effects in habitual coffee drinkers that persist for many hours during the activities of everyday life. Furthermore, caffeine may exaggerate sympathetic adrenal-medullary responses to the stressful events of normal daily life. Repeated daily blood pressure elevations and increases in stress reactivity caused by caffeine consumption could contribute to an increased risk of coronary heart disease in the adult population.     

Job strain and anger expression predict early morning elevations in salivary cortisol

OBJECTIVE: The objectives of this study were to test the hypothesis that high job demands and low job control (job strain) are associated with elevated free cortisol levels early in the working day and with reduced variability across the day and to evaluate the contribution of anger expression to this pattern. METHODS: One hundred five school teachers (41 men and 64 women) classified 12 months earlier as high (N = 48) or low (N = 57) in job strain according to the demand/control model sampled saliva at 2-hour intervals from 8:00 to 8:30 hours to 22:00 to 22:30 hours on a working day. Anger expression was assessed with the Speilberger State-Trait Anger Expression Inventory, and negative affect was also measured. RESULTS: Free cortisol was significantly elevated at 8:00 to 8:30 hours in the high job strain group but not at later times of the day or evening. After adjustment for age and negative affect, cortisol was an average of 21.7% higher early in the working day in the high job strain group. This effect was significantly greater in high job strain teachers, who also reported high anger-out. The cortisol decline from morning to evening was greater in the high than low job strain individuals. Independently of job strain, women had a higher cortisol concentration at 8:00 to 8:30 hours than men, whereas cortisol concentration was greater in men than women in the middle of the working day between 12:00 and 16:30 hours. CONCLUSIONS: Job strain is associated with elevated free cortisol concentrations early in the working day but not with reduced cortisol variability. The interaction with outward anger expression suggests that individual characteristics modulate the impact of chronic work stress on the hypothalamic-pituitary-adrenocortical system.     

Stress, social support and cardiovascular activity over the working day.

The influence of stress on ambulatory blood pressure monitored over the working day, and the potential buffering effect of social support, was assessed in 104 school teachers (37 men and 67 women). Blood pressure and heart rate were measured every 20 min and energy expenditure was assessed using accelerometers. Participants rated the degree of stress they were experiencing at the time of each measurement on a seven-point scale. Episodes of both high and low stress during the working day were reported by 62 participants. They were divided by median split into high and low social support groups on the Interpersonal Support Evaluation List. After controlling for body mass and concomitant energy expenditure, high stress was associated with increased systolic blood pressure, diastolic blood pressure and heart rate. However, the impact of stress was buffered by social support, with no significant increase in blood pressure or heart rate with stress in the high support group. The accelerometers were also shown effectively to discriminate between blood pressure readings taken in the seated and standing positions in terms of energy expenditure. The results corroborate laboratory studies, in showing that social support buffers the impact of episodic stress on cardiovascular activity under naturalistic conditions during the working day.     

Ambulatory blood pressure, heart rate, and neuroendocrine responses in women nurses during work and off work days.

OBJECTIVE: This study examined women's cardiovascular and neuroendocrine responsiveness to work. METHODS: Ambulatory blood pressure (BP) and heart rate (HR) were recorded over 24-hour periods on 2 work and 2 off days during the luteal and follicular phases of the menstrual cycle in 138 registered nurses, aged 25 to 50 years. Urinary catecholamines and cortisol were measured for day and night periods. RESULTS: During waking hours systolic BP (SBP), HR, and epinephrine were higher on work than off days. Diastolic BP (DBP) and HR were highest at work. Nurses scoring high on job demands had elevations in daytime SBP, daytime HR only on work days, and nighttime epinephrine on work days. Compared with those with short work histories, nurses employed longer had consistently higher norepinephrine levels during days and nights, and higher nighttime DBP during off days. In unmarried nurses compared with married nurses, nighttime cortisol was lower during all 4 days and norepinephrine was lower during days off. All findings were independent of actigraph-recorded activity. CONCLUSIONS: Although the work environment leads to increased activity of the cardiovascular and sympathoadrenal medullary system in healthy women, the effects are modified by the woman's domestic role, by the length of her employment, and by the demands of her job.     

Cardiovascular responses to an active coping challenge as predictors of blood pressure patterns 10 to 15 years later.

To assess the long-term predictive importance of high cardiovascular reactivity in relation to subsequent blood pressure, 51 men from a pool of 204 men originally tested at age 18 to 22 years were recruited for blood pressure assessment 10 to 15 years later. Initial testing uniformly involved monitoring of systolic pressure, diastolic pressure, and heart rate during a reaction time task involving threat of shock. In 30 of the 51 men who participated at follow-up, initial testing had also included separate visits to obtain relaxation-only baseline levels of the cardiovascular indices. At follow-up, in addition to clinic-type stethoscopic determinations, blood pressure and heart rate were assessed during work and social and leisure activities via ambulatory monitoring. Men with higher levels of systolic pressure during the task showed higher stethoscopic and ambulatory systolic pressure at follow-up. Likewise, men with higher levels of diastolic pressure during the task showed higher diastolic levels at follow-up. In the 30 men with both good task and baseline data from initial testing, those with high heart rate reactivity (task minus baseline) showed higher systolic, diastolic, and heart rate levels at follow-up than low heart rate reactors, even though their baseline blood pressures had not differed at initial testing. Similarly, men with high systolic reactivity showed higher diastolic pressure at follow-up than low systolic reactors. Multiple regression analyses also demonstrated that systolic, diastolic, and heart rate reactivity improve prediction of follow-up blood pressure when added to models incorporating the standard risk factors, baseline blood pressure, and parental history of hypertension.     

Do the daily experiences of healthy men and women vary according to occupational prestige and work strain?

OBJECTIVE: This study evaluated the influence of occupational prestige and work strain on mood, the occurrence of interpersonal conflict, and ambulatory blood pressure and heart rate. METHODS: Participants were 50 men and 50 women matched for occupational prestige who were healthy and middle-aged and who completed measures of mood and conflict simultaneously with measures of ambulatory blood pressure and heart rate recorded every 30 minutes during waking hours of two workdays and one nonworkday; at the end of each day, overall ratings were made. Work strain was assessed by the Work Section of the Self-Evaluation and Social Support Interview Schedule. Multiple level random regression coefficients analyses were conducted. RESULTS: Men and women with low-prestige occupations experienced more interpersonal conflict, b = -0.03, p = .04, and higher ambulatory heart rate, b = -4.83, p = .004, throughout the three days of the study. Relative to those with low work strain, those reporting high work strain experienced negative emotion, b = -0.41, p < .0001, and boredom, b = -0.17, p < .0004. End of the day ratings of negative mood were more influenced by work strain among men than among women. No effects of occupational prestige or work strain were obtained for ambulatory blood pressure readings after adjustment for physical activity, posture, and location. CONCLUSIONS: Individuals in low-prestige occupations experience greater exposure to interpersonal conflict and arousal as indexed by heart rate, which might increase risk for stress-related illnesses often associated with social class. Individuals who report work strain experience negative mood and boredom, both at work and at home. The absence of work effects on ambulatory blood pressure may be due to the participants being healthy.     

Ambulatory blood pressure monitoring is associated with reduced physical activity during everyday life

OBJECTIVE: The objective of this study was to assess the impact on noninvasive ambulatory blood pressure monitoring on physical activity measured objectively by use of triaxial accelerometers. METHODS: Twenty-four working men and women performed ambulatory blood pressure plus activity monitoring for 1 working day and evening and activity monitoring alone for a separate day and evening. Blood pressure measures were taken at 20-minute intervals during the day and 30-minute intervals in the evening and were accompanied by diary assessments of mood, location, and posture. Comparisons were made of energy expenditure on the 2 days and of activity levels during the minutes surrounding each blood pressure reading and diary completion. RESULTS: Energy expenditure assessed in terms of activity calories per hour was significantly lower during blood pressure plus activity monitoring compared with activity monitoring alone (mean 37.3, SD = 16.3 vs. mean = 43.0, SD = 18.7 kcal, respectively: p = .02). Energy expenditure was lower during the 4 minutes surrounding each blood pressure reading than in the intervals between blood pressure readings. However, energy expenditure was also lower in the intervals between blood pressure readings than during comparable times on the activity only monitoring day. Blood pressure, heart rate, and physical activity were moderately correlated within individuals. CONCLUSIONS: Ambulatory blood pressure recording using automated sphygmomanometers is associated with reduced physical activity during the monitoring day. This is due partly to regular periods of immobility during cuff inflation and deflation and diary completion and partly to more general self-imposed restrictions on activity. This pattern has implications for the representativeness of ambulatory blood pressure monitoring, and the construction of ambulatory monitoring diaries.     

Work family balance, stress, and salivary cortisol in men and women academic physicians

Background: The stress of medical practice has been recurrently studied, but work- and family-related determinants of health by gender remain under researched. Purpose: To test the hypothesis that cortisol excretion would be affected by the perceived severity of total workload imbalance. Method: By hierarchical regression analysis, the associations between work-family balance and diurnal salivary cortisol levels by sex in academic physicians (n = 40) were investigated. Results: Men physicians reported more paid work hours per week than women physicians and women more time in childcare, but their total working hours were similar. Controlling for sex and age, the mean of the diurnal cortisol release was associated with a combined effect of sex and responsibility at home. When morning cortisol, sex, and children at home were held constant, cortisol levels in the evening were associated with responsibility at home without significant gender interaction. Conclusion: With increasing responsibility at home, women and men reacted differently with regard to cortisol responses over the day. However, in the evening, controlling for the morning cortisol, these gender differences were not as obvious. These findings highlight traditional gender patterns among both women and men physicians in the challenge of finding a balance between work and family.     

Psychophysiological reactions to telework in female and male white-collar workers

Information technology has created greater flexibility and mobility for employees, such as teleworkers. However, research on stress and health is limited. This study investigated psychophysiological arousal in 26 highly educated white-collar workers (12 women and 14 men) while (a) working at the office, (b) working at home (telework), and (c) relaxing at home. Blood pressure was significantly higher during work at the office than when teleworking at home, and men had significantly elevated epinephrine levels in the evening after telework at home. It was assumed that the lower cardiovascular arousal during telework is due to different work tasks and that elevated epinephrine levels in men after telework are caused by continued work after normal working hours.     

Impact of acute sleep restriction on cortisol and leptin levels in young women

Sleep restriction alters hormone patterns and appetite in men, but less is known about effects on women. We assessed effects of overnight sleep restriction on cortisol and leptin levels and on appetite in young women. Participants' baseline sleep duration and eating habits were monitored for a week before the study. Salivary cortisol and leptin were sampled from fifteen healthy women (aged 18-25) during two consecutive days: first after a 10 h overnight sleep opportunity (Baseline day) and then after a night including only 3 h sleep (Post sleep-restriction day). Participants also completed appetite questionnaires on both days. Sleep restriction significantly reduced morning cortisol levels (p = 0.02), elevated morning leptin levels (p = 0.04), elevated afternoon/evening cortisol area under the curve values (p = 0.008), and slowed the decline in cortisol concentration during the day (p = 0.04). Hunger and craving scores did not differ significantly between days. A single night of restricted sleep affected cortisol rhythms and morning leptin levels in young women.     

Isometric strength,endurance, and the blood pressure and heart rate responses during isometric exercise in healthy men and women,with special reference to age and body fat content

The relationship of sex, age, and body fat content were assessed on the maximal voluntary strength (MVC), the endurance of a sustained contraction held at 40% of the subject's maximal strength, and the associated changes in blood pressure and heart rate. Isometric hand-grip strength was, as expected, greater in men than in women; however, in both sexes, age was inversely related to isometric strength, particularly in women. Body fat content, however, was directly related to strength. In contrast, in both male and female subjects aging was directly related to isometric endurance while body fat content was now inversely related to isometric endurance. The increase in heart rate throughout a fatiguing contraction at 40% MVC was strikingly similar in men and women. Heart rate, which always increased during exercise, attained its highest magnitude during exercise in the subjects who had the highest resting heart rates. However, older subjects displayed a smaller increase in exercising heart rates than younger subjects. The blood pressure at the end of the 40% MVC was directly related to the resting blood pressure. However, aging and body fat content both increased the resting systolic blood pressure in men and women; this aging effect was further exaggerated during the exercise.     

Work pressure and the type A behavior pattern exam stress in male medical students

The psychologic and physiologic effects of variations in occupational stress on Type A (coronary-prone) and Type B men have not previously been examined. Accordingly, 58 male medical students in two successive first-year classes (32 As, 26 Bs defined by interview) were tested for mood states, perception of work pressure, and for pituitary-adrenal and cardiovascular function during a period of minimal work pressure (no exams for 1 week) and during maximal work pressure (final exam week). All observations were made at the beginning of the school day, while the students were studying course material in the building where classes were held and study modules were located. Perceived stress and self-ratings of dysphoric moods increased significantly (ps less than 0.0005) for both groups during exams compared to no exams. Plasma cortisol concentrations increased significantly (+20%) from no exams to exams for both As and Bs. Heart rate increased significantly to exams (+8%) and did so slightly more for As (+9%) than for Bs (+7%), with As showing significantly higher rates in the work setting at both times. Systolic blood pressure increased nonsignificantly for both groups. The effect of the higher heart rate and the slight systolic blood pressure rise produced a significantly greater rate-pressure product for As than for Bs at both exams and no exams (p less than 0.005), with As showing a larger rise to exams than did Bs (+11% vs. +8%). Results indicate that the As had a higher level of tonic cardiovascular activation in the work place than the Bs, and that this was additive with the effects of increased work pressure.     

Physiological stress response of young adults exposed to bullying during adolescence

Peer victimization in the form of bullying is a chronic social stressor experienced by many humans during development. Exposure to bullying has been associated with a variety of mental disorders, such as anxiety and depression. Participants pre-selected for the presence or absence of a history of being bullied were brought into a laboratory and placed in a stressful situation. Blood pressure, heart rate, and salivary cortisol levels were measured before the introduction of the stressor (Time 1), at the end of the stressor (Time 2), and after its removal (Time 3). Men with a history of exposure to frequent bullying showed blunted blood pressure responses at Time 2 compared to control men. Bullied and Non-bullied women did not show any differences in any of the measures. Men and women in both groups showed an increase in heart rate in response to the stressor. There were no significant differences in salivary cortisol levels between Bullied and Non-bullied participants. However, salivary cortisol levels and systolic blood pressure were lower in Bullied male participants who reported having no feelings of anger about their experience compared to controls and those who did report anger. These data show altered sympathetic responses to stress in men with a history of victimization as well as suggesting long-term effects on the HPA axis in the most affected individuals.     

The relationship between long-term job strain and morning and evening saliva cortisol secretion among white-collar workers

The objective of this study was to assess long-term job strain impact on morning and evening salivary cortisol secretion. In all 77 white-collar workers (31% women; sample mean age, 42 years at baseline) volunteered to sample morning (immediately after waking up) and evening (10 p.m.) salivary cortisol for 7 consecutive days. By median split on aggregated self-reported isostrain from three consecutive questionnaires distributed in a period of approximately 3.5 years the participants were classified into a high or low long-term isostrain condition. Regardless of strain condition, there was a significant reduction in morning salivary cortisol secretion from the working week to the weekend, whereas evening salivary cortisol secretion showed no significant variation during the week. Although chronic isostrain did not affect the morning saliva cortisol measures, evening cortisol secretion was significantly elevated in the chronic high isostrain group throughout the whole week. The elevated evening cortisol measures associated with chronic high strain are concordant with the findings in other studies on long-term strain.     

Cardiovascular and Metabolic Activity at Rest and During Psychological and Physical Challenge in Normotensives and Subjects With Mildly Elevated Blood Pressure

Heart rate, systolic and diastolic blood pressure, and respiratory and metabolic activity were recorded prior to and during mental arithmetic and a video game task in 20 young men with mildly elevated casual systolic blood pressures. Twenty-five unambiguously normotensive young men were tested under the same protocol. For pretask baseline physiological activity, group differences emerged for all cardiovascular and metabolic variables; thus the elevated blood pressure group displayed not only higher resting cardiovascular levels than normotensive subjects, but higher levels of metabolic activity too. With regard to change in physiological activity from rest to task, the group with mildly elevated blood pressure showed reliably larger increases in heart rate to the mental arithmetic task than the normotensive subjects. These effects, however, were not paralleled by group differences in metabolic activity increase. Physiological measures were also taken prior to and during graded dynamic exercise. The subsequent calculation of individual heart rate-oxygen consumption exercise regression lines allowed the comparison of actual and predicted heart rates during psychological challenge. The subjects with mildly elevated blood pressure displayed significantly greater discrepancies between actual and predicted heart rate values than normotensives during the psychological tasks in general and menta¹ arithmetic in particular. Group differences in physiological activity during exercise largely reflected the pattern seen at rest. A possible exception here was systolic blood pressure. Not only were systolic blood pressure levels higher throughout the exercise phase for mildly elevated blood pressure subjects, but this group evidenced more of an increase from rest to exercise than the normotensives.     

Pace variation and control of work pace as related to cardiovascular, neuroendocrine, and subjective responses

Two studies of paced and self-paced arithmetic performance are reported. Heart rate and blood pressure were recorded and ratings of subjective arousal obtained. In one of the studies, plasma levels of catecholamines and cortisol were determined. Under externally paced experimental conditions pace variation was found to be quantitatively related to changes in systolic and diastolic blood pressure, as well as to ratings of stress and irritation. This was not the case for heart rate or positively evaluated aspects of subjective arousal. Performance was better and ratings of stress and irritation were lower during self-paced than during paced work at a comparable work pace. In one of the studies the diastolic blood pressure increased less when subjects controlled the pace. Plasma catecholamines did not increase significantly during either externally or self-paced work, but adrenaline tended to increase during paced work. Our findings give partial support to the suggestion that personal control may attenuate sympathoadrenal activation and cardiovascular reactivity.     

Socioeconomic position and cardiovascular and neuroendocrine responses following cognitive challenge in old age

Social disparities in health persist into old age, and differences in psychophysiological responsivity may contribute to this pattern. We assessed whether higher socioeconomic status (SES) is associated with attenuated cardiovascular and neuroendocrine responses elicited by cognitive tasks in old age. We tested 132 community-dwelling men and women aged 65-80 years, divided on the basis of educational attainment into higher and lower SES groups, and compared them with 26 higher educated participants aged 27-42 years. Blood pressure, hemodynamic variables and salivary cortisol were assessed in response to the performance of three cognitive tasks, and then during recovery. Older groups showed smaller heart rate and larger cortisol changes than younger participants. Post-task recovery in heart rate, stroke volume, pre-ejection period, and systolic blood pressure was greatest in the younger group, least in the older/lower education group, and intermediate in the older/higher education group. SES did not influence the increased cortisol responsivity of older participants. The results are consistent with the notion that higher SES protects against age-related changes in cardiovascular response profiles, particularly during recovery.     

Ambulatory blood pressure and heart rate in relation to hot flash experience among women of menopausal age

OBJECTIVE: The purpose of this study was to evaluate whether ambulatory blood pressure and heart rate varied with hot flash experience among women of menopausal age. SUBJECTS AND METHODS: A total of 1149 ambulatory blood pressure and heart rate measurements from 20 women aged 44-55 were examined. Women were categorized by hot flash experience as (1) having had hot flashes during the study period (Symptomatic during Study; n = 5; 302 measurements), (2) having a past history of hot flashes, but no hot flashes during the study period (Historically Symptomatic; n = 7; 385 measurements), and (3) never having had a hot flash (Asymptomatic; n = 8; 462 measurements). Using repeated measures, nested ANOVA models that also adjusted for posture, the variation in blood pressure and heart rate associated with hot flash experience over the whole day and by location of measurement (microenvironment) was evaluated. RESULTS: The results show that, overall, systolic pressure did not differ among the hot flash experience groups although the Symptomatic during Study group had higher pressures at work than the other two groups (p<0.01), and tended to have higher pressures during sleep (p<0.08). The sleep diastolic pressure of the Asymptomatic group was significantly lower than that of the women who had hot flashes on the study day (p<0.01), but women who had a past history of hot flashes had slightly lower diastolic pressure (p<0.01) than those in the other two groups overall. Heart rates of the Asymptomatic group, however, were significantly lower (4-6 b.p.m.; p<0.001) in each microenvironment and over the whole day than both groups who had hot flash experience. CONCLUSIONS: These data suggest first that there may be a relationship between the experience of hot flashes and accelerated heart rate, and second that women who do not experience hot flashes may have lower sleep blood pressures than women who do.     

Physiological stress responses in defensive individuals: Age and sex matter

The association between defensiveness and physiological responses to stress were evaluated in 81 healthy working men and 118 women, aged 20 to 64 years (M=41; SD=11.45). Participants underwent laboratory testing during which they were exposed to interpersonal stressors. Heart rate (HR), heart rate variability (HRV), blood pressure (BP), and salivary cortisol were measured. Defensiveness was evaluated using the Marlowe‐Crowne Social Desirability Scale. In women, higher defensiveness was associated with greater BP and HR reactivity to stress (p<.05). In older men, lower defensiveness was associated with increased systolic BP reactivity to stress (p<.02), delayed HRV recovery (p<.02), and greater salivary cortisol levels (p<.02). In conclusion, greater defensiveness was associated with increased reactivity to stress in women whereas in older men, lower defensiveness was associated with elevated cardiovascular, autonomic, and endocrine responses to stress.