title: Overcommitment to work is associated with changes in cardiac sympathetic regulation.
abstract: OBJECTIVE
  Work stress is associated with an increased risk for cardiovascular disease (CVD). Exaggerated cardiovascular reactivity to work-related stressors or incomplete recovery after work is a proposed mechanism underlying this increase in risk. This study examined the effects of work stress on 24-hour profiles of the pre-ejection period (PEP), a measure of cardiac sympathetic activity, obtained from ambulatory measurement of the impedance cardiogram.
  
  
  METHODS
  A total of 67 male white-collar workers (age 47.1 +/- 5.2) underwent ambulatory monitoring on 2 workdays and 1 non-workday. Work stress was defined according to Siegrist's model as 1) a combination of high effort and low reward at work (high imbalance) or 2) an exhaustive work-related coping style (high overcommitment).
  
  
  RESULTS
  High overcommitment was associated with shorter absolute PEP levels during all periods on all 3 measurement days, reduced wake-to-sleep PEP differences and reduced PEP variability, as indexed by the SD.
  
  
  CONCLUSIONS
  Overcommitment to work was associated with an increase in basal sympathetic drive and a reduction in the dynamic range of cardiac sympathetic regulation. Both findings are compatible with the hypothesis that overcommitment induces beta-receptor down-regulation.
authors.affiliation: Department of Social Medicine/Public Health and Epidemiology, Academic Medical Centre, Postbox 22700, 1100 DE Amsterdam, The Netherlands. t.vrijkotte@amc.uva.nl
authors.forename: Tanja G M
authors.initials: TG
authors.lastname: Vrijkotte
authors.forename: Lorenz J P
authors.initials: LJ
authors.lastname: van Doornen
authors.forename: Eco J C
authors.initials: EJ
authors.lastname: de Geus
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D002307:Cardiography, Impedance / Q000706:statistics & numerical data; D002940:Circadian Rhythm / Q000502:physiology*; D015536:Down-Regulation / Q000502:physiology; D015716:Electrocardiography, Ambulatory / Q000706:statistics & numerical data; D006304:Health Status; D006321:Heart / Q000294:innervation* / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D013315:Stress, Psychological / Q000503:physiopathology* / Q000523:psychology; D013564:Sympathetic Nervous System / Q000502:physiology* / Q000503:physiopathology; D014937:Work / Q000502:physiology* / Q000523:psychology
chemical_list: D011943:Receptors, Adrenergic, beta