title: Effect of shift work on endothelial function in young cardiology trainees.
abstract: BACKGROUND
  Long-term shift work (SW) is associated with an increase in cardiovascular disease (CVD). Previous studies have shown that prolonged SW is associated with endothelial dysfunction, suggesting that this abnormality may contribute to the SW-related increase in cardiovascular risk. The immediate effect of SW on endothelial function in healthy subjects, however, is unknown.
  
  
  METHODS
  We studied endothelial function and endothelium-independent function in 20 healthy specialty trainees in cardiology at our Institute, without any cardiovascular risk factor (27.3 ± 1.9 years, nine males), at two different times: (1) after a working night (WN), and (2) after a restful night (RN). The two test sessions were performed in a random sequence.
  
  
  METHODS
  Endothelial function was assessed by measuring brachial artery dilation during post-ischaemic forearm hyperaemia (flow-mediated dilation, FMD). Endothelium-independent function in response to 25 µg of sublingual glyceryl trinitrate (nitrate-mediated dilation, NMD) was also assessed.
  
  
  RESULTS
  FMD was 8.02 ± 1.4% and 8.56 ± 1.7% after WN and RN, respectively (p = 0.025), whereas NMD was 10.5 ± 2.1% and 10.4 ± 2.0% after WN and RN, respectively (p = 0.48). The difference in FMD between WN and RN was not influenced by the numbers of hours slept during WN (<4 vs >4 hours) and by the duration of involvement of specialty trainees in nocturnal work (<12 vs >12 months).
  
  
  CONCLUSIONS
  Our study shows that in healthy medical residents, without any cardiovascular risk factor, FMD is slightly impaired after WN compared to RN. Disruption of physiological circadian neuro-humoral rhythm is likely to be responsible for this adverse vascular effect.
authors: Department of Cardiovascular Medicine, Catholic University of Sacred Heart, Rome, Italy.
authors: Pierpaolo
authors: P
authors: Tarzia
authors: Maria
authors: M
authors: Milo
authors: Antonino
authors: A
authors: Di Franco
authors: Antonio
authors: A
authors: Di Monaco
authors: Alessandro
authors: A
authors: Cosenza
authors: Marianna
authors: M
authors: Laurito
authors: Gaetano Antonio
authors: GA
authors: Lanza
authors: Filippo
authors: F
authors: Crea
mesh_terms: D000328:Adult; D001916:Brachial Artery / Q000502:physiology*; D002055:Burnout, Professional / Q000150:complications / Q000503:physiopathology*; D002309:Cardiology / Q000193:education; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D012016:Reference Values; D012307:Risk Factors; D013337:Students, Medical; D014664:Vasodilation / Q000502:physiology*; D014937:Work; D014938:Work Capacity Evaluation