Occupational class differences in ankle-brachial index and pulse wave velocity measurements to detect subclinical vascular disease

Background:

High pulse wave velocity (PWV) and low ankle brachial index (ABI) have been proposed as surrogate end-points for cardiovascular disease (CVD).

Objectives:

In a cross-sectional setting, we aimed at assessing the distributions of PWV and ABI among occupational classes (OC) in a population-based ever-employed salaried sample.

Methods:

We enrolled 1388 salaried CVD-free workers attending a CVD population-based survey, the RoCAV study, and classified them into four OC, based on current or last job title: manager/director (MD), non-manual (NMW), skilled-manual (SMW) and (UMW) unskilled-manual workers. We derived brachial-ankle PWV and ABI from four-limb blood pressures measurements, then carotid-femoral PWV (cfPWV) was estimated. We estimated the OC gradients in cfPWV and ABI using linear and logistic regression models.

Results:

Compared to MD (reference category), UMW had higher age- and BMI-adjusted cfPWV mean values both in men (0.63 m/s; 95%CI:0.11-1.16) and women (1.60 m/s; 0.43-2.77), only marginally reduced when adjusting for CVD risk factors. Decreased ABI mean values were also detected in lower OC. The overall detection rate of abnormal cfPWV (≥12 m/s) or ABI (≤0.9) values was 28%. Compared to MD, the prevalence of abnormal cfPWV or ABI was higher in NMW (OR=1.77; 95%CI:1.12-2.79), SMW (1.71; 1.05-2.78) and UMW (2.72; 1.65-4.50). Adjustment for CVD risk factors used in risk score equations did not change the results.

Discussion:

We found a higher prevalence of abnormal values of arterial stiffness measures in lower OC, and these differences were not explained by traditional CVD risk factors. These may be presumably determined by additional work- and environmental-related risk factors.

The effect of exposure to long working hours on ischaemic heart disease: A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) are developing Joint Estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates), with contributions from a large network of experts. Evidence from mechanistic data suggests that exposure to long working hours may cause ischaemic heart disease (IHD). In this paper, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from IHD that are attributable to exposure to long working hours, for the development of the WHO/ILO Joint Estimates.

OBJECTIVES

We aimed to systematically review and meta-analyse estimates of the effect of exposure to long working hours (three categories: 41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on IHD (three outcomes: prevalence, incidence and mortality).

DATA SOURCES

We developed and published a protocol, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic databases for potentially relevant records from published and unpublished studies, including MEDLINE, Scopus, Web of Science, CISDOC, PsycINFO, and WHO ICTRP. We also searched grey literature databases, Internet search engines and organizational websites; hand-searched reference lists of previous systematic reviews; and consulted additional experts.

STUDY ELIGIBILITY AND CRITERIA

We included working-age (≥15 years) workers in the formal and informal economy in any WHO and/or ILO Member State but excluded children (aged < 15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies which contained an estimate of the effect of exposure to long working hours (41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on IHD (prevalence, incidence or mortality).

STUDY APPRAISAL AND SYNTHESIS METHODS

At least two review authors independently screened titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. Missing data were requested from principal study authors. We combined relative risks using random-effect meta-analysis. Two or more review authors assessed the risk of bias, quality of evidence and strength of evidence, using Navigation Guide and GRADE tools and approaches adapted to this project.

RESULTS

Thirty-seven studies (26 prospective cohort studies and 11 case-control studies) met the inclusion criteria, comprising a total of 768,751 participants (310,954 females) in 13 countries in three WHO regions (Americas, Europe and Western Pacific). The exposure was measured using self-reports in all studies, and the outcome was assessed with administrative health records (30 studies) or self-reported physician diagnosis (7 studies). The outcome was defined as incident non-fatal IHD event in 19 studies (8 cohort studies, 11 case-control studies), incident fatal IHD event in two studies (both cohort studies), and incident non-fatal or fatal ("mixed") event in 16 studies (all cohort studies). Because we judged cohort studies to have a relatively lower risk of bias, we prioritized evidence from these studies and treated evidence from case-control studies as supporting evidence. For the bodies of evidence for both outcomes with any eligible studies (i.e. IHD incidence and mortality), we did not have serious concerns for risk of bias (at least for the cohort studies). No eligible study was found on the effect of long working hours on IHD prevalence. Compared with working 35-40 h/week, we are uncertain about the effect on acquiring (or incidence of) IHD of working 41-48 h/week (relative risk (RR) 0.98, 95% confidence interval (CI) 0.91 to 1.07, 20 studies, 312,209 participants, I² 0%, low quality of evidence) and 49-54 h/week (RR 1.05, 95% CI 0.94 to 1.17, 18 studies, 308,405 participants, I² 0%, low quality of evidence). Compared with working 35-40 h/week, working ≥55 h/week may have led to a moderately, clinically meaningful increase in the risk of acquiring IHD, when followed up between one year and 20 years (RR 1.13, 95% CI 1.02 to 1.26, 22 studies, 339,680 participants, I² 5%, moderate quality of evidence). Compared with working 35-40 h/week, we are very uncertain about the effect on dying (mortality) from IHD of working 41-48 h/week (RR 0.99, 95% CI 0.88 to 1.12, 13 studies, 288,278 participants, I² 8%, low quality of evidence) and 49-54 h/week (RR 1.01, 95% CI 0.82 to 1.25, 11 studies, 284,474 participants, I² 13%, low quality of evidence). Compared with working 35-40 h/week, working ≥55 h/week may have led to a moderate, clinically meaningful increase in the risk of dying from IHD when followed up between eight and 30 years (RR 1.17, 95% CI 1.05 to 1.31, 16 studies, 726,803 participants, I² 0%, moderate quality of evidence). Subgroup analyses found no evidence for differences by WHO region and sex, but RRs were higher among persons with lower SES. Sensitivity analyses found no differences by outcome definition (exclusively non-fatal or fatal versus "mixed"), outcome measurement (health records versus self-reports) and risk of bias ("high"/"probably high" ratings in any domain versus "low"/"probably low" in all domains).

CONCLUSIONS

We judged the existing bodies of evidence for human evidence as "inadequate evidence for harmfulness" for the exposure categories 41-48 and 49-54 h/week for IHD prevalence, incidence and mortality, and for the exposure category ≥55 h/week for IHD prevalence. Evidence on exposure to working ≥55 h/week was judged as "sufficient evidence of harmfulness" for IHD incidence and mortality. Producing estimates for the burden of IHD attributable to exposure to working ≥55 h/week appears evidence-based, and the pooled effect estimates presented in this systematic review could be used as input data for the WHO/ILO Joint Estimates.

Exploring the interplay between job strain and different domains of physical activity on the incidence of coronary heart disease in adult men

AIMS

The aim of this study was to investigate the independent associations of occupational (OPA) and sport physical activity (SpPA) and job strain on the incidence of coronary heart disease (CHD) events, and to explore their interplay.

METHODS

The study sample included 3310 25-64-year-old employed men, free of CHD at baseline, recruited in three population-based and one factory-based cohorts. OPA and SpPA, and job strain were assessed by the Baecke and the Job Content Questionnaires, respectively. We estimated the associations between different domains of physical activity and job strain with CHD, adjusting for major risk factors using Cox models.

RESULTS

During follow-up (median=14 years), 120 CHD events, fatal and non-fatal, occurred. In the entire sample, a higher CHD risk was found for high job strain (hazard ratio=1.55, 95% confidence interval: 1.05-2.31). The joint effect of low OPA and high job strain was estimated as a hazard ratio of 2.53 (1.29-4.97; reference intermediate OPA with non-high strain). With respect to intermediate OPA workers, in stratified analysis when SpPA is none, low OPA workers had a hazard ratio of 2.13 (95% confidence interval: 1.19-3.81), increased to 3.95 (1.79-8.78) by the presence of high job strain. Low OPA-high job strain workers take great advantage from SpPA, reducing their risk up to 90%. In contrast, the protective effect of SpPA on CHD in other OPA-job strain categories was modest or even absent, in particular when OPA is high.

CONCLUSIONS

Our study shows a protective effect of recommended and intermediate SpPA levels on CHD risk among sedentary male workers. When workers are jointly exposed to high job strain and sedentary work their risk further increases, but this group benefits most from regular sport physical activity.

Differing associations for sport versus occupational physical activity and cardiovascular risk

OBJECTIVES

We investigate the independent and interacting long-term associations of occupational physical activity (OPA) and sport physical activity (SpPA) with the incidence of coronary heart disease (CHD) and cardiovascular diseases (CVD; CHD plus ischaemic stroke) in North Italian male workers.

METHODS

3574 employed men aged 25-64 years, free of CVD at baseline, recruited in three population-based and one factory-based cohorts, were included in the analysis. The Baecke Questionnaire was used to assess OPA and SpPA in 'minutes per week' of moderate or vigorous PA. We estimated the associations between different domains of PA and the endpoints, adjusting for major CVD risk factors, using Cox models.

RESULTS

During a median follow-up of 14 years, 135 and 174 first CHD and CVD events, fatal and non-fatal, occurred. Compared with the intermediate OPA tertile, the HRs for CHD among low and high OPA workers were 1.66 (95% CI 1.06 to 2.59) and 1.18 (0.72 to 1.94), respectively (P value=0.07). Decreasing trends in CHD and CVD rates across increasing levels of SpPA were also found, with an HR for CVD of 0.68 (0.46 to 0.98) for intermediate/recommended SpPA compared with poor SpPA. We also found a statistically significant SpPA-OPA interaction, and the protective effect of SpPA was only found among sedentary workers, for both endpoints. Conversely, high OPA workers with intermediate/recommended SpPA levels had increased CHD and CVD rates compared with the poor SpPA category.

CONCLUSIONS

Our results provide further evidence on the health paradox of OPA, with higher CVD rates among workers with intense PA at work. Moreover, the protective effect on CVDs of SpPA is prominent in sedentary workers, but it attenuates and even reverses in moderate and strenuous OPA workers.

The correlation between stress and economic crisis: a systematic review

In 2008 a deep economic crisis started in the US and rapidly spread around the world. The crisis severely affected the labor market and employees' well-being. Hence, the aim of this work is to implement a systematic review of the principal studies that analyze the impact of the economic crisis on the health of workers. We conducted our search on the PubMed database, and a total of 19 articles were selected for review. All studies showed that the economic crisis was an important stressor that had a negative impact on workers' mental health. Most of the studies documented that a rise in unemployment, increased workload, staff reduction, and wages reduction were linked to an increased rate of mood disorders, anxiety, depression, dysthymia, and suicide. Some studies showed that problems related to the crisis may have also affected the general health of workers by increasing the risk of such health problems as cardiovascular and respiratory diseases. Finally, some studies looked at the impact of the crisis on health care services. These studies demonstrated that the reduction in public expenditure on health care services, and the reduction of public hospital budgets due to the recession, led to organizational problems (eg, medical supply shortages).