title: The perception of work stressors is related to reduced parasympathetic activity.
abstract: OBJECTIVE
  The aim was to examine the perception of work stressors in relation to ambulatory measures of heart rate variability (HRV).
  
  
  METHODS
  Results are based on a sample of 653 healthy male workers aged 40-55 from the Belgian Physical Fitness Study conducted in 1976-1978. Data were collected by means of self-administered questionnaires and bio-clinical examinations. An index of physical and psychosocial work stressors containing five items was constructed based on the job stress questionnaire. Data on HRV were collected by means of 24-h ambulatory ECG recordings on a working day. Both time and frequency domain measures of HRV were calculated. Associations between work stressors and HRV measures were assessed by means of correlations, multiple linear regression analysis and analysis of (co)variance.
  
  
  RESULTS
  The work stressor index was significantly associated with lower pNN50 (the percentage of differences between adjacent normal RR intervals > 50 ms), lower high frequency power and a higher ratio of low frequency over high frequency power. Very similar results were obtained after adjusting for age, language, occupation, smoking, body mass index, total cholesterol, systolic blood pressure and leisure time physical activity. No significant associations were found with SDNN (the standard deviation of all normal RR intervals) and low frequency power.
  
  
  CONCLUSIONS
  The perception of work stressors was related to reduced parasympathetic activity in a sample of 653 healthy male workers. These findings support the idea that particularly the parasympathetic component of the autonomic nervous system is related to work stress.
authors.affiliation: Department of Public Health, Ghent University, University Hospital, Block A, De Pintelaan 185, 9000 Ghent, Belgium. els.clays@UGent.be
authors.forename: Els
authors.initials: E
authors.lastname: Clays
authors.forename: Dirk
authors.initials: D
authors.lastname: De Bacquer
authors.forename: Vincent
authors.initials: V
authors.lastname: Crasset
authors.forename: France
authors.initials: F
authors.lastname: Kittel
authors.forename: Patrick
authors.initials: P
authors.lastname: de Smet
authors.forename: Marcel
authors.initials: M
authors.lastname: Kornitzer
authors.forename: Robert
authors.initials: R
authors.lastname: Karasek
authors.forename: Guy
authors.initials: G
authors.lastname: De Backer
mesh_terms: D000328:Adult; D001530:Belgium; D015331:Cohort Studies; D003327:Coronary Disease / Q000209:etiology; D003627:Data Interpretation, Statistical; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000502:physiology*; D010465:Perception; D011446:Prospective Studies; D012307:Risk Factors; D013312:Stress, Physiological; D013315:Stress, Psychological; D011795:Surveys and Questionnaires; D014937:Work