title: Effort-reward imbalance at work and 5-year changes in blood pressure: the mediating effect of changes in body mass index among 1400 white-collar workers.
abstract: OBJECTIVE
  A number of prospective studies have documented the effect of adverse psychosocial work factors (work stress) on high blood pressure (BP). Weight gain could be an important pathway by which work stress exerts its effect on BP. No previous prospective study has examined this mediating effect. The aim of the present study was to examine the mediating effect of body mass index (BMI) in the association between psychosocial work factors from Siegrist's effort-reward imbalance model (ERI) and ambulatory BP (ABP).
  
  
  METHODS
  A prospective study was conducted among 1436 white-collar workers. Data were collected three times during a 5-year period. ERI was measured using validated scales, at each time. BMI was measured by a trained assistant. ABP was measured every 15 min during a working day.
  
  
  RESULTS
  ERI exposure onset over 3 years was indirectly associated with ABP changes (0.49 mmHg; 95 % CI 0.05, 1.22), through BMI changes, in women with baseline BMI ≥25 kg/m2. An effect of similar magnitude and of borderline significance was observed for ERI chronic exposure. No mediating effect was observed among men, and using ERI exposure over 5 years.
  
  
  CONCLUSIONS
  The mediating effect of BMI was of small magnitude and observed in certain subgroups and time frame only. Subgroup-specific mediating pathways might be involved to explain the effect of work stress on cardiovascular diseases risk.
authors.affiliation: Axe santé des populations et pratiques optimales en santé, Centre de recherche FRQS du CHU de Quebec, 1050, Chemin Ste-Foy, Quebec City, QC, G1S 4L8, Canada. xavier.trudel@crchudequebec.ulaval.ca.
authors.forename: Xavier
authors.identifier: http://orcid.org/0000-0002-7734-072X
authors.initials: X
authors.lastname: Trudel
authors.affiliation: Axe santé des populations et pratiques optimales en santé, Centre de recherche FRQS du CHU de Quebec, 1050, Chemin Ste-Foy, Quebec City, QC, G1S 4L8, Canada.|Département de médecine sociale et préventive, Université Laval, Quebec City, QC, Canada.
authors.forename: Chantal
authors.initials: C
authors.lastname: Brisson
authors.affiliation: Département de médecine, Université Laval, Quebec City, QC, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: Milot
authors.affiliation: Département de médecine sociale et préventive, Université de Montréal, Montreal, QC, Canada.
authors.forename: Benoit
authors.initials: B
authors.lastname: Masse
authors.affiliation: Département de médecine sociale et préventive, Université Laval, Quebec City, QC, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Vézina
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D015992:Body Mass Index; D005260:Female; D006801:Humans; D006973:Hypertension / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000523:psychology; D016273:Occupational Exposure / Q000009:adverse effects*; D011446:Prospective Studies; D012201:Reward; D012737:Sex Factors; D013315:Stress, Psychological / Q000523:psychology; D016526:Workload; D017132:Workplace / Q000523:psychology
keywords: Ambulatory blood pressure; Body mass index; Work stress