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.