title: Workplace bullying, sleep problems and leisure-time physical activity: a prospective cohort study.
abstract: OBJECTIVE
  Workplace bullying is a potent stressor that may increase sleep problems. Since physical fitness improves resilience to stress, it seems plausible that recreational physical activities may moderate the association between bullying and sleep. The study aimed to examine prospectively whether (i) bullying increases the risk of sleep problems, and (ii) the association between bullying and sleep problems is moderated by leisure-time physical activity (LTPA).
  
  
  METHODS
  The study sample comprised a cohort of public and private sector employees, who were enrolled into the Work Bullying and Harassment (WBH) cohort (N=3278) or the Psychosocial Risk Factors for Stress and Mental Disease (PRISME) cohort (N=4455). We measured workplace bullying using one question that was preceded by a definition of bullying. We used the Karolinska sleep questionnaire to assess sleep problems. The number of hours per week spent on LTPA estimated the degree of physical activity.
  
  
  RESULTS
  Workplace bullying at baseline (T1) was associated with awakening problems and lack of restful sleep at follow-up (T2) but not with overall sleep problems and disturbed sleep. T1-LTPA did not moderate the association between T1-workplace bullying and T2-sleep problems.
  
  
  CONCLUSIONS
  We found support that workplace bullying is related to development of T2-sleep problems, but this association seems not to be modified by LTPA.
authors.affiliation: Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, DK-1014 Copenhagen K, Denmark. asemarie.hansen@sund.ku.dk.
authors.forename: Åse Marie
authors.initials: ÅM
authors.lastname: Hansen
authors.forename: Maria
authors.initials: M
authors.lastname: Gullander
authors.forename: Annie
authors.initials: A
authors.lastname: Hogh
authors.forename: Roger
authors.initials: R
authors.lastname: Persson
authors.forename: Henrik A
authors.initials: HA
authors.lastname: Kolstad
authors.forename: Morten Vejs
authors.initials: MV
authors.lastname: Willert
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Bonde
authors.forename: Linda
authors.initials: L
authors.lastname: Kaerlev
authors.forename: Reiner
authors.initials: R
authors.lastname: Rugulies
authors.forename: Matias Brødsgaard
authors.initials: MB
authors.lastname: Grynderup
mesh_terms: D000328:Adult; D058445:Bullying; D015444:Exercise / Q000523:psychology*; D005260:Female; D006801:Humans; D007899:Leisure Activities / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D016272:Occupational Health; D011446:Prospective Studies; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000209:etiology*; D011795:Surveys and Questionnaires; D017132:Workplace / Q000523:psychology*