Arrhythmias and increased neuro-endocrine stress response during physicians' night shifts: a randomized cross-over trial

Eur Heart J. 2009 Nov;30(21):2606-13. doi: 10.1093/eurheartj/ehp268. Epub 2009 Jul 14.


Aims: To evaluate the effects of a 24 h (h) physicians on-call duty (OCD) ('night shift') on 24 h electrocardiogram (ECG), heart rate variability, blood pressure (BP), and various biochemical serum and urine 'stress markers' compared with a 'regular' day at work.

Methods and results: The study was designed as a prospective randomized cross-over trial with each physician completing a 24 h (h) OCD and a 24 h control period including a regular 8 h non-OCD. Thirty healthy physicians with a median age of 33.5 years (range 29.0-45.0) were analysed. Twenty-four hours ECG and BP monitoring were performed and participants were instructed to fill out an event diary and perform a 24 h urine collection. Furthermore, blood was drawn before and after OCD and control day. Twenty-four hours ECG showed a higher rate of ventricular premature beats (VPB) during early morning hours (VPB 0-6 h, 0.5 vs. 0.0, P = 0.047) and increased low-frequency normalized units (29.3 vs. 25.5, P = 0.050) during night shift when compared with respective control night at home. During OCD, BP monitoring revealed a greater diastolic BP throughout 24 h (83.5 vs. 80.2 mmHg, P = 0.025) as well as during night-time (75.4 vs. 73.0, P = 0.028) associated with a higher rate of systolic BP more than 125 mmHg during sleep time. Tumour necrosis factor alpha concentrations increased significantly during night shift (0.76 vs. 0.05 pg/mL, P = 0.045). Urinary noradrenaline excretion was greater during OCD when compared with control day (46.0 vs. 36.0 microg/24 h, P = 0.007).

Conclusion: Our results highlight the association of OCD with an increased risk profile for cardiovascular disease. In addition to the acute effects observed, frequent night-calls over a longer period possibly elicit sustained alterations in cardiovascular homeostasis.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Arrhythmias, Cardiac / blood
  • Arrhythmias, Cardiac / etiology*
  • Arrhythmias, Cardiac / physiopathology
  • Biomarkers / metabolism*
  • Blood Pressure / physiology
  • Circadian Rhythm / physiology
  • Cross-Over Studies
  • Electrocardiography
  • Female
  • Heart Rate / physiology
  • Humans
  • Male
  • Occupational Diseases / blood
  • Occupational Diseases / etiology*
  • Occupational Diseases / physiopathology
  • Personnel Staffing and Scheduling*
  • Physicians
  • Stress, Psychological / blood
  • Stress, Psychological / complications*
  • Stress, Psychological / physiopathology
  • Work Schedule Tolerance / physiology*


  • Biomarkers