title: Occupational physical activity and mortality among Danish workers.
abstract: OBJECTIVE
  The relationship between occupational physical activity (OPA) and mortality has mainly been studied among males and shows conflicting results. This study examines this relationship in a cohort of both male and female workers.
  
  
  METHODS
  OPA was determined by 4 self-reported questions in a representative sample of 5,839 Danish workers aged 18-59 years at baseline. A 19-year follow-up on mortality was assessed by linkage with the national death registry. Gender-stratified Cox regression models were used to determine the effect of high OPA on all-cause mortality while controlling for age, BMI, smoking, alcohol consumption, doctor-diagnosed disease, influence at work, and social class.
  
  
  RESULTS
  Two hundred and sixty-two males (8.6%) and 174 females (6.2%) died during follow-up. Being in the highest quartile of OPA predicted an increased risk for all-cause mortality among male workers (HR: 1.79, CI: 1.19-2.70), but not among female workers (HR: 0.99, CI: 0.65-1.49) compared with workers in the lowest quartile of OPA. Among females, indications of a u-shaped relationship between occupational physical activity and all-cause mortality were found.
  
  
  CONCLUSIONS
  The findings indicate that high occupational physical activity increases the risk for all-cause mortality among male workers. Future studies need to further examine gender differences in the effects of OPA on mortality.
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark. aho@nrcwe.dk
authors.forename: Andreas
authors.initials: A
authors.lastname: Holtermann
authors.forename: Hermann
authors.initials: H
authors.lastname: Burr
authors.forename: Jørgen V
authors.initials: JV
authors.lastname: Hansen
authors.forename: Niklas
authors.initials: N
authors.lastname: Krause
authors.forename: Karen
authors.initials: K
authors.lastname: Søgaard
authors.forename: Ole S
authors.initials: OS
authors.lastname: Mortensen
mesh_terms: D000293:Adolescent; D000328:Adult; D002423:Cause of Death; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D016273:Occupational Exposure / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D012737:Sex Factors; D015996:Survival Rate; D055815:Young Adult