Yolande Esquirol

Shift work and cardiovascular risk factors : New knowledge from the past decade

Cardiovascular diseases remain a major public health problem. The involvement of several occupational factors has recently been discussed, notably the organization of work schedules, e.g. shift work. To analyse the progress of knowledge on the relationship between cardiovascular risk factors and shift work. A review of English-language literature dealing with the link between cardiovascular factors and shift workers (published during 2000-2010) was conducted. Studies published in the past 10 years tend to document an impact of shift work on blood pressure, lipid profile (triglyceride levels), metabolic syndrome and, possibly, body mass index. However, the consequences on glucose metabolism are unclear. These results are not yet firmly established, but are supported by strong hypotheses. Some advice could reasonably be proposed to guide the clinical practitioner.

Environmental factors associated with body mass index in a population of Southern France

Study objective Environmental-factor changes may largely be accountable for the dramatic increase of obesity prevalence in industrialized countries. This study investigated the relationships between body mass index (BMI) and various socioeconomic, clinical, behavioural and reproductive factors in a population from Southern France. Methods Using a cross-sectional study, a sample of 3127 current and former salaried workers (1658 men and 1469 women) completed a questionnaire on personal and medical histories, and had a clinical examination including height and weight measurements. Age-adjusted and multiple linear regression analyses were performed. Results The overall prevalence of obesity (BMI ≤ 30kg/m2) was 9.8% and was higher in men than in women (11.1 versus 8.3%). Multivariate analyses showed that in both sexes, low educational level, television watching, low physical activity and ex-smoking habits, were independently associated with a higher BMI. Furthermore, in women, we found independent and positive associations between BMI and the number of naps per week, short sleep duration, daily alcohol consumption, the number of pregnancies, early age at menarche or the non-use of oral contraceptives. Conclusions Our results reveal the complexity that exists between BMI and environmental factors and stress the need to analyse and to handle these factors simultaneously.

Shiftwork and Higher Pancreatic Secretion: Early Detection of an Intermediate State of Insulin Resistance?

Previous studies have suggested that shiftwork can affect the prevalence of metabolic syndrome. This is thought to be related to disturbance of lipid parameters rather than their effects on glucose metabolism. Several complex mechanisms are suspected to be involved and notably insulin resistance, though the available data are limited. The objective of the present study was to provide further evidence for the effects of shiftwork on glucose and lipid metabolism with a specific focus on insulin resistance. A cross-sectional study has recruited 97 shiftworkers (SWs) (three shifts, 8 h) and 95 strictly day workers (DWs) from the same plant for 2001–2002. Several indices of insulin sensitivity or resistance were calculated, based on formulas of the homeostasis model assessment for insulin resistance (HOMA-IR), the Revised-Quicki, McAuley and Disse indices. The HOMA-β-cell index was used as a reflection of pancreatic secretion. Characteristics of the occupation, habitual diet and lifestyles were recorded. Logistic regression analysis in which pancreatic function or insulin sensitivity was the dependent variable was used to compare alternative models. Results: SWs were characterized as having significantly higher triglycerides and free fatty acids and normal but lower blood glucose. The risk of a high β-cell activity was increased almost three-fold in SWs. By adjusting for many confounding factors, SWs had significantly lower insulin sensitivity according to several indices, whereas HOMA-IR was not meaningfully different between shift and DWs. Lower insulin sensitivity and a compensatory pancreas response to maintain a normal glucose tolerance may suggest an intermediate state before development of frank insulin resistance in SWs. Early detection of these moderate alterations of the insulin/glucose balance could be important in the prevention of diabetes.

The Predictive Value of Depressive Symptoms for All-Cause Mortality: Findings From the PRIME Belfast Study Examining the Role of Inflammation and Cardiovascular Risk Markers.

Objectives To improve understanding about the potential underlying biological mechanisms in the link between depression and all-cause mortality and to investigate the role that inflammatory and other cardiovascular risk factors may play in the relationship between depressive symptoms and mortality. Methods Depression and blood-based biological markers were assessed in the Belfast PRIME prospective cohort study (N = 2389 men, aged 50–59 years) in which participants were followed up for 18 years. Depression was measured using the 10-item Welsh Pure Depression Inventory. Inflammation markers (C-reactive protein [CRP], neopterin, interleukin [IL]-1 receptor antagonist [IL-1Ra], and IL-18) and cardiovascular-specific risk factors (N-terminal pro–b-type natriuretic peptide, midregion pro–atrial natriuretic peptide, midregion pro-adrenomedullin, C-terminal pro–endothelin-1 [CT-proET]) were obtained at baseline. We used Cox proportional hazards modeling to examine the association between depression and biological measures in relation to all-cause mortality and explore the mediating effects. Results During follow-up, 418 participants died. Higher levels of depressive symptoms were associated with higher levels of CRP, IL-1Ra, and CT-proET. After adjustment for socioeconomic and life-style risk factors, depressive symptoms were significantly associated with all-cause mortality (hazard ratio = 1.10 per scale unit, 95% confidence interval = 1.04–1.16). This association was partly explained by CRP (7.3%) suggesting a minimal mediation effect. IL-1Ra, N-terminal pro–b-type natriuretic peptide, midregion pro–atrial natriuretic peptide, midregion pro-adrenomedullin, and CT-proET contributed marginally to the association between depression and subsequent mortality. Conclusions Inflammatory and cardiovascular risk markers are associated with depression and with increased mortality. However, depression and biological measures show additive effects rather than a pattern of meditation of biological factors in the association between depression and mortality.

Contribution of occupational factors to the incidence and persistence of chronic low back pain among workers: results from the longitudinal VISAT study

Objective Among the aetiological factors of chronic low back pain (CLBP), occupational factors are often suspected, but their contribution remains to be ascertained. This study aimed to determine the impact of a wide range of occupational factors on the incidence and persistence of CLBP. Method From the VISAT (VIeillissement SAnté Travail) study, 1560 workers were examined at baseline and 5 years later. CLBP was defined as having low back pain or specific treatment for at least 6 months. Participants newly affected with CLBP and those with persistent CLBP at follow-up were distinguished. In addition to individual factors, a broad panel of occupational factors were analysed, covering employment, physical, organisational and psychosocial factors. Multivariate analyses were used to determine predictive factors of incidence and persistence of CLBP. Receiver operating characteristic (ROC) curves were performed to analyse the contribution of occupational factors. Results 22.6% of participants without any CLBP initially presented with CLBP 5 years later, while 53.7% of participants with CLBP at baseline had CLBP at the second collection. Carrying heavy loads, the lack of recognition of completed work and productivity-related income predicted a higher risk of incidence of CLBP. However, no significant association between occupational factors and the risk for persistence of CLBP was observed, while the risk was multiplied by two for history of depression and rheumatological events. ROC curves confirmed the significant contribution of occupational factors to incidence of CLBP. Conclusions Occupational factors played a pivotal role in the incidence of CLBP, while individual factors were the main determinants of persistence of CLBP.

An intriguing occupational atypical dermatitis with respiratory symptoms

Methylisothiazolinone (MI), alone or in association with methylchloroisothiazolinone (MCI), is widely used as a preservative in cosmetic and occupational products, and is currently inducing an outbreak of sensitization throughout Europe (1). In the 2000s, MI as stand-alone preservative was introduced in industrial water-based products. Since 2005, several cases of occupational dermatitis caused by MI and MCI/MI have been described, including airborne contact dermatitis among painters (2). Only rarely have related respiratory disorders been described (3). In this case, combined dermatological and respiratory problems were seen, mimicking atopic disease, following airborne occupational exposure to a facade render containing MI and MCI/MI.

Sédentarité et activité physique en milieu professionnel

Sedentary behaviors are a leading cause of preventable mortality in developed countries. We mainly have sedentary behaviors at work. Sedentary behaviors must be considered as an occupational risk, and therefore must be a major concern for managers and physicians/health researchers. Recreational physical activity only partly compensates for the negative effects of physical inactivity at work. Physical activity at work without excess (walking, standing) is beneficial. Initiatives to reduce physical inactivity and increase physical activity among employees are effective in terms of mental health, physical health, and productivity. Prevention of sedentary behaviors at work is a win-win partnership between employers and employees.

Occupational exposure to pesticides: development of a job-exposure matrix for use in population-based studies (PESTIPOP)

Occupational exposure to pesticides concerns a wide population of workers not only in agriculture. The reliability of self-reported information on pesticide use is questionable because of the diversity of use. The PESTIPOP job-exposure matrix has been designed to assess pesticide occupational exposure in the general population. The matrix is composed of two axes: the first axis corresponding to jobs (combinations of occupations and industries) and the second one to pesticide exposure. The estimated exposure metric is the probability of exposure coupled with a reliability assessment (low, medium or high). These metrics were defined by combining different sources: (1) an a priori expert assessment (Agricultural industry experts); (2) data from a multicenter case–control study on brain tumors in the general population (occupational history, specific questionnaires); and (3) an a posteriori expert assessment based on the data of a case–control study. So far, 2559 jobs have been identified and 209 (8%) were found to be exposed to pesticides. Jobs with agricultural exposure had a higher exposure probability than jobs with non-agricultural exposure (wood preservation, park maintenance, pest control). Indirect exposure was more frequent than direct exposure. The PESTIPOP matrix will be transcoded into international classifications for use in epidemiological studies.

0086: Does leisure physical activity efficiently decrease the consequences of occupational social inequalities on cardiovascular diseases? Prime study

Background regular leisure physical activity is encouraged to reduce the risk of cardiovascular disease (CVD) and mortality, but the observance of this guideline is not perfect. In parallel, the consequences of occupational-social inequalities on CVD have been well-described and persist. Objective To assess the potential mediating effect of leisure physical activity on the consequences of occupational status on CVD. Method 5683 French employed men were recruited from the cohort Prime study. Employees and manual workers were compared with white collar (chef of enterprise, intermediate staff). Hard CVD, myocardial infarction, angina, coronary death, total heart events and stroke were investigated over a 10 years follow-up. Leisure physical activity was measured using compendium physical activity. Cox analyses were used for analyzing the consequences of social inequalities on each event adjusted for classical cardiovascular risks. The propor-tion of effect was calculated to explain the potential mediating effect of leisure physical activity on the relationship between occupational social categories and CVD. Results The incidence rates were respectively for: Hard CVD (2.4%), myocardial infarction (2.2%), angina (3.4%), coronary death (0.4%), total heart events (5.7%) and stroke (1.1%). Employees and manual workers have significant higher risks of hard cardiovascular events, myocardial infarction and total heart events compared with white collar, in crude analysis (HR≈1.5). Adjustments for classical cardiovascular factors reduced significantly these risks while a weak impact of leisure physical activity on the relationships between occupational categories and each event was highlighted. Conclusion The cardiovascular gradient observed between the different occupational categories is mainly explained by classical cardiovascular factors. Leisure physical activity is not sufficient by itself to compensate the occupational social inequalities.

0088: Could occupational determinants impact on changes in blood pressure over a five-years follow-up? Results from the VISAT study

Background Occupational environment is often suspected to be involved in increased Blood Pressure (BP), but asserting its causality remains uncertain. Purpose To assess the impact of a large panel of occupational factors exposures on changes of BP over a 5-year follow-up period. Methods 790 participants were recruited during 2001-2006 in a French cohort study. Four categories of occupational factors were investigated: physical constraints, organizational and psychosocial factors and employment-related characteristics, allowing nearly exploring 30 occupational determinants. Changes in Systolic BP (SBP) and Diastolic BP (DBP) between the two surveys were dichotomized into increased BP versus decreased or unchanged BP. Logistic regressions were performed to explain how each occupational factor interacts with changes in BP, after adjustment for several classical confounding factors. Receiver Operating Characteristic (ROC) curves were used to determine whether occupational factors could improve the prediction of BP changes. Results No physical constraint was significantly associated with changes in BP. Among organizational factors, only particular working hour schedule had a protective effect on SBP (OR=0.72). The main effect on BP changes was obtained by psychosocial factors. Taking on several tasks at the same time, not being able to interrupt work or being exposed to an active job strain significantly predicted a high risk of an increased SBP (OR≈1.50). In contrast, occupational recognition and consideration of expressed employee opinion, tended to be associated with a protective effect (OR≈0.70). Comparing areas under the ROC curves revealed that occupational factors significantly improved the prediction of SBP changes, compared to taking into account only the classic cardiovascular risks. Conclusion Psychosocial factors appear as the major determinants of changes of BP over time with a dual effect, whereas biomechanical occupational factors play a minor role.