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

Association between psychosocial work-related factors at midlife and arterial stiffness at older age in a prospective cohort of 1736 white-collar workers

OBJECTIVE

Arterial stiffness and exposure to psychosocial work-related factors increase the risk of developing cardiovascular disease. However, little is known about the relationship between psychosocial work-related factors and arterial stiffness. We aimed to examine this relationship.

DESIGN

Prospective cohort study.

SETTING

Public organisations in Quebec City, Canada.

PARTICIPANTS

The study included 1736 white-collar workers (women 52%) from 19 public organisations.

PRIMARY AND SECONDARY OUTCOME MEASURES

Association between psychosocial work-related factors from the job strain and effort-reward imbalance (ERI) models assessed at study baseline (1999-2001) with validated instruments and arterial stiffness assessed using carotid-femoral pulse wave velocity at follow-up, on average 16 years later (2015-2018). Generalised estimating equations were used to estimate differences in arterial stiffness between exposed and unexposed participants. Subgroup analyses according to sex, age, blood pressure (BP), cardiovascular risk score and employment status were conducted.

RESULTS

Among participants with high diastolic BP (≥90 mm Hg) at baseline, aged 47 on average, those exposed to high job strain had higher arterial stiffness (1.38 m/s (95% CI: 0.57 to 2.19)) at follow-up, 16 years later, following adjustment for a large set of potential confounders. The trend was similar in participants with high systolic BP (≥140 mm Hg) exposed to high job strain (0.84 m/s (95% CI: -0.35 to 2.03)). No association was observed for ERI in the total sample and counterintuitive associations were observed in subgroup analyses.

CONCLUSIONS

Job strain may have a long-term deleterious effect on arterial stiffness in people with high BP. Interventions at midlife to reduce job strain may mitigate arterial stiffness progression.

Effects of aerobic exercise training on mental health and arterial stiffness in middle-aged and older adults

BACKGROUND

Aging is associated with deterioration of arterial function and mental health, which are known as cardiovascular risk factors. The present study investigated the effect of aerobic exercise training on mental health and arterial stiffness in middle-aged and older adults.

METHODS

Twenty-nine healthy middle-aged and older adults were assigned to either the aerobic exercise training (N.=14) or the control groups (N.=15). The aerobic exercise training group completed 12 weeks of moderate aerobic exercise training for 3-4 session per week (30-60 minutes). The control group did not change their levels of physical activity. Before and after the 12-week period, the General Health Questionnaire (GHQ) and carotid β-stiffness index, peak oxygen uptake were measured.

RESULTS

At the onset of the 12-week period, the GHQ score, Carotid Β-Stiffness Index, and other key variables did not differ significantly between the aerobic exercise and control groups. The 12-week of aerobic exercise training increased peak oxygen uptake. The GHQ score and Carotid Β-Stiffness Index were decreased after the 12-week period in the aerobic exercise training group; however, no significant improvements were observed in the control group.

CONCLUSIONS

We conclude that 12 weeks of aerobic exercise enhance mental health and decrease arterial stiffness in healthy middle-aged and older adults.

Sex-dependent correlates of arterial stiffness in Tanzanian adults

OBJECTIVE

Arterial stiffness is a known indicator for cardiovascular disease. However, the factors that lead to arterial stiffening have primarily been studied in participants from high-income countries. Here, we examine clinical and lifestyle metrics in relation to arterial stiffness in Tanzanian adults.

METHODS

We performed pulse wave velocity (PWV), the gold standard measure of arterial stiffness, on 808 Tanzanian adults (ages 18-65) enrolled in a longitudinal cohort studying trends in blood pressure.

RESULTS

As expected, PWV was strongly associated with age, blood pressure and sex. We controlled for these factors in our statistical analysis. Lifestyle metrics were compared across multiple PWV quantiles. We found that determinants of PWV varied by sex: in female participants, PWV was associated with common obesity metrics and menopause, while in male participants, PWV was associated with HIV status and duration of anti-retroviral therapy (ART). Further clinical and lifestyle factors such as marriage status and type of occupation were also significantly associated with PWV and moderated by sex.

CONCLUSION

Together, our data demonstrate the importance of studying sex-specific causal pathways for arterial stiffness and of including under-represented populations in these studies.

Acute mental stress-caused arterial stiffening can be counteracted by brief aerobic exercise

PURPOSE

Acute mental stress (MS) causes an elevation in pulse wave velocity (PWV), an index of arterial stiffness. In contrast, aerobic exercise acutely decreases arterial stiffness, even in the short term. The present study aimed to examine whether acute MS-caused arterial stiffening can be counteracted by brief aerobic exercise.

METHODS

Thirteen young healthy men (mean age, 20 ± 1 years) participated in two randomized experimental visits where they were subjected to acute MS followed by seated rest (RE) or cycling exercise (EX) trials. Following a 5-min MS task, the participants in the RE trial rested on a chair for 10 min (from 10 to 20 min after the cessation of the task), whereas those in the EX trial cycled at 35% of heart rate reserve for the same duration. Heart-brachial PWV (hbPWV), brachial-ankle PWV (baPWV), heart-ankle PWV (haPWV), and the cardio-ankle vascular index (CAVI) were simultaneously measured at baseline and 5, 30, and 45 min after the task.

RESULTS

Both trials caused significant elevations (P < 0.05) in hbPWV, haPWV, and CAVI at 5 min after the task; subsequently, this persisted until 45 min after the task in the RE trial, whereas the elevations in the EX trial were eliminated. In the RE trial, baPWV significantly increased (P < 0.05) at 30 and 45 min after the task, whereas such an increase was not observed in the EX trial.

CONCLUSION

The findings of the present study reveal that brief aerobic exercise counteracts arterial stiffening caused by acute MS.

Impact of acute mental stress on segmental arterial stiffness

PURPOSE

It has been reported that acute brief episodes of mental stress (MS) result in a prolonged increase in carotid-femoral pulse wave velocity (cfPWV), an index of aortic stiffness. However, whether acute MS also impacts arterial stiffness in other segments is unclear. The present study aimed to examine the impact of acute MS on segmental arterial stiffness.

METHODS

In the main experiment, 17 young male subjects (mean age, 20.1 ± 0.7 years) performed a 5-min MS and control (CON) task in a random order. Pulse wave velocity (PWV) from the heart to the brachium (hbPWV) and the ankle (haPWV), PWV between the brachial artery and the ankle (baPWV), and the cardio-ankle vascular index (CAVI) were simultaneously measured at baseline and 5, 15, and 30 min after the task.

RESULTS

Compared to baseline values, hbPWV, baPWV, haPWV, and CAVI significantly increased until 30 min after the MS task, whereas these variables did not significantly change following the CON task. At 5 and 30 min after the MS task, percentage changes from baseline were significantly higher in hbPWV (+ 5.2 ± 4.4 and 6.6 ± 4.9%) than in baPWV (+ 2.2 ± 2.1 and 2.2 ± 2.0%) or haPWV (+ 3.6 ± 2.6 and 4.3 ± 2.9%) and were also significantly lower in baPWV than in haPWV.

CONCLUSION

These findings suggest that acute MS elicits an increase in arterial stiffness in various segments and this arterial stiffening is not uniform among the segments.

Social Role-Related Stress and Social Role-Related Reward as Related to Subsequent Subclinical Cardiovascular Disease in a Longitudinal Study of Midlife Women: The Study of Women's Health Across the Nation

OBJECTIVE

The purpose of this study was to determine if midlife social role quality, defined by the stress and rewards associated with four social roles, is related to later-life subclinical cardiovascular disease (SCVD) in a cohort of women transitioning through menopause.

METHODS

The Study of Women's Health Across the Nation (SWAN) is a longitudinal cohort study of midlife women. Stress and reward from four social roles (spouse, parent, employee, caregiver) were assessed at seven early visits. Later-life SCVD was assessed via carotid ultrasound and brachial-ankle pulse wave velocity at two later visits. We tested whether ever reporting an "extremely" or "quite a bit" stressful role was related to SCVD. We also tested whether cumulative stress and reward, as well as baseline and change in stress and reward were related to SCVD, adjusting for demographics and cardiovascular risk factors.

RESULTS

Among 1602 women, reporting a stressful role during midlife (between ages 47 and 52 years) was associated with later-life (age 61 years) carotid intima-media thickness, which was 21 μm thicker than never reporting a stressful role. No significant relationships between stressful roles and other SCVD measures were identified. Cumulative and baseline change models of stress and reward were not related to SCVD.

CONCLUSION

A stressful social role in midlife was associated with greater atherosclerotic burden in later-life in a cohort of women transitioning through menopause. Social role rewards were unrelated to better later-life SCVD. These findings extend the knowledge of stress and cardiovascular disease in women by using measures of stress and reward for multiple social roles over the years of midlife.

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

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

Socioeconomic status, education, and aortic stiffness progression over 5 years: the Whitehall II prospective cohort study

Objective:

The inverse association between socioeconomic status (SES) and cardiovascular disease (CVD) risk is well documented. Aortic stiffness assessed by aortic pulse wave velocity (PWV) is a strong predictor of CVD events. However, no previous study has examined the effect of SES on arterial stiffening over time. The present study examines this association, using several measures of SES, and attained education level in a large ageing cohort of British men and women.

Methods:

Participants were drawn from the Whitehall II study. The sample was composed of 3836 men and 1406 women who attended the 2008–2009 clinical examination (mean age = 65.5 years). Aortic PWV was measured in 2008–2009 and in 2012–2013 by applanation tonometry. A total of 3484 participants provided PWV measurements on both occasions. The mean difference in 5-year PWV change was examined according to household income, education, employment grade, and father's social class, using linear mixed models.

Results:

PWV increase [mean: confidence interval (m/s)] over 5 years was higher among participants with lower employment grade (0.38: 0.11–0.65), household income (0.58, 95%: 0.32–0.85), and education (0.30: 0.01, 0.58), after adjusting for sociodemographic variables, BMI, alcohol consumption, smoking, and other cardiovascular risk factors, namely SBP, mean arterial pressure, heart rate, cholesterol, diabetes, and antihypertensive use.

Conclusion:

The present study supports the presence of robust socioeconomic disparities in aortic stiffness progression. Our findings suggest that arterial aging could be an important pathophysiological pathway explaining the impact of lower SES on CVD risk.

Relationship between overtime work hours and cardio-ankle vascular index (CAVI): a cross-sectional study in Japan

OBJECTIVES

The purpose of this research was to evaluate the relationship between overtime work hours and CAVI, a new index of arterial stiffness.

METHODS

We measured CAVI of Japanese workers (3,862 men) aged 26 to 59 years. Simultaneously, we obtained information on their monthly overtime work hours for the past few months using a self-administered questionnaire, with responses divided into five groups: <45, ≥45 and <60, ≥60 and <80, ≥80 and <100 and ≥100 hours/month. We calculated the odds ratios of CAVI≥9.0 for each group of overtime work hours.

RESULTS

In the full sample, there was no significant association between the average CAVI and overtime work hours. Taking<45 overtime hours/month as the reference category, the odds ratios of CAVI≥9.0 were as follows: OR=1.11, 95% CI=0.73-1.69 (≥45 and <60 hours/month); OR=0.92, 95% CI=0.48-1.76 (≥60 and <80 hours/month); OR=1.50, 95% CI=0.50-4.49 (≥80 and <100 hours/month); and OR=2.65, 95% CI=0.82-8.54 (≥100 hours/month). However, for workers in their 50 s, the odds ratio of CAVI≥9.0 was significantly higher among subjects with≥100 hours/month than among those with<45 hours/month (OR=4.26, 95% CI=1.2-15.1) CONCLUSIONS: The present study suggests that CAVI is more likely to be 9.0 or higher in workers in their 50 s when they work≥100 hours of overtime per month.

Psychological stress and arterial stiffness in Korean Americans

OBJECTIVE

Arterial stiffness is identified as a causative factor for hypertension. The purpose of this study was to explore the relationship between psychological stress and arterial stiffness in Korean Americans.

METHODS

A convenience sample of 102 Korean Americans (aged 21-60 years, 60% women) was recruited from North Carolina. Psychological stress was measured by the Perceived Stress Scale, the Social, Attitudinal, Familiar, and Environmental (SAFE) Acculturative Stress Scale, and the Spielberger's State-Trait Anxiety Inventory. Arterial stiffness was measured by carotid-femoral pulse wave velocity (cfPWV) using the SphygmoCor system (AtCor Medical, Australia).

RESULTS

This study shows that the emotional stress response, measured by anxiety, significantly predicted arterial stiffness (β=.25, p=.008), independently of such confounding factors as age, mean arterial pressure (MAP), gender, body mass index, smoking, education, and income. Anxiety was neither related to age (r=.12, p=.212) nor MAP (r=.14, p=.151). Additionally, this sample of Korean Americans had higher levels of psychological stress when compared to previous findings from studies of other racial/ethnic groups in the U.S.

CONCLUSION

Findings demonstrate that anxiety is a significant and independent determinant of arterial stiffness. Given that anxiety was not related to MAP, these findings suggest that arterial stiffness may be a pathway to explain the connection between anxiety and hypertension risk. Studies that scrutinize the relationship between anxiety and arterial stiffness are an important next step for future research. Further studies are also recommended to explore cultural factors and individual characteristics that may affect anxiety in Korean Americans.

The role of psychosocial stress at work for the development of cardiovascular diseases: a systematic review

PURPOSE

A systematic review was carried out to assess evidence for the association between different models of stress at work, and cardiovascular morbidity and mortality.

METHODS

A literature search was conducted using five databases (MEDLINE, Cochrane Library, EMBASE, PSYNDEX and PsycINFO). Inclusion criteria for studies were the following: self-reported stress for individual workplaces, prospective study design and incident disease (myocardial infarction, stroke, angina pectoris, high blood pressure). Evaluation, according to the criteria of the Scottish Intercollegiate Guidelines Network, was done by two readers. In case of disagreement, a third reader was involved.

RESULTS

Twenty-six publications were included, describing 40 analyses out of 20 cohorts. The risk estimates for work stress were associated with a statistically significant increased risk of cardiovascular disease in 13 out of the 20 cohorts. Associations were significant for 7 out of 13 cohorts applying the demand-control model, all three cohorts using the effort-reward model and 3 out of 6 cohorts investigating other models. Most significant results came from analyses considering only men. Results for the association between job stress and cardiovascular diseases in women were not clear. Associations were weaker in participants above the age of 55.

CONCLUSIONS

In accordance with other systematic reviews, this review stresses the importance of psychosocial factors at work in the aetiology of cardiovascular diseases. Besides individual measures to manage stress and to cope with demanding work situations, organisational changes at the workplace need to be considered to find options to reduce occupational risk factors for cardiovascular diseases.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Inflammation as a cardiovascular risk factor and pulse wave velocity as a marker of early-stage atherosclerosis in the Japanese population

Inflammation and pulse wave velocity (PWV) are a potential risk factor and marker, respectively, for atherosclerosis in the primary prevention setting. Atherosclerosis is now generally accepted to be an inflammatory disorder of the arterial wall, and the high-sensitivity C-reactive protein (hs-CRP) level has been reported to be a strong predictor of cardiovascular events. High-sensitivity-CRP is associated with two factors related to inflammation: (1) the local production of CRP by atheromatous tissue or coronary artery smooth muscle cells and (2) adipose tissue as a potent source of inflammatory cytokines. Based on studies in North America and Europe, hs-CRP has been established as a cardiovascular risk factor and a cut-off value has been recommended. However, Japanese have lower hs-CRP values than their Western counterparts, partly because Japanese have a lower body mass index (BMI), which correlates positively to hs-CRP, and partly because lifestyle and genetic factors can affect hs-CRP values. Therefore, a cut-off value needs to be established by cohort studies for the Japanese population. Carotid-femoral PWV is most commonly measured by applanation tonometry, particularly in Europe, but this method is critically dependent upon the accurate placing of transducers over the arteries and is both time-consuming and complex. A novel device has been recently developed in Japan that measures brachial-ankle PWV (baPWV) using a volume-rendering method. Brachian-ankle PWV is a suitable screening method because of its technical simplicity and shorter measurement time. It is associated not only with conventional cardiovascular risk factors but also with new risk factors, such as inflammation, gamma-glutamyltransferase, chronic kidney disease, and psychosocial factors. However, a suitable cut-off value has yet to be established.