title: Effect of acute sleep deprivation on heart rate recovery in healthy young adults.
abstract: BACKGROUND
  Sleep deprivation (SD) is known to be associated with increased incidence of adverse cardiovascular events, but underlying pathophysiological mechanism has not been clearly demonstrated. Autonomic nervous system plays an important role in the regulation of cardiovascular function, and impairment in this system is associated with increased cardiovascular mortality. The aim of the current study was to investigate the effect of acute SD on autonomic regulation of cardiac function by determining heart rate recovery (HRR).
  
  
  METHODS
  Twenty-one healthy security officers and nine nurses (mean age 33.25 ± 8.18) were evaluated. Treadmill exercise test was applied once after a night with regular sleep and once after a night shift in hospital. The HRR was calculated as the reduction in heart rate from peak exercise to the 30th second (HRR30), 1st minute (HRR1), 2nd minute (HRR2), 3rd minute (HRR3), and 5th minute (HRR5). The change in blood pressure (BP) measurements was also determined.
  
  
  RESULTS
  Exercise capacity of individuals with SD was significantly lower (10.96 ± 1.01 vs. 11.71 ± 1.30 metabolic equivalent task (MET)s; p = 0.002), and peak systolic BP was significantly higher (173.8 ± 16.3 vs. 166.2 ± 9.9; p = 0.019). There was a signicant difference in HRR30 (12.74 ± 6.19 vs. 17.66 ± 5.46; p = 0.003) and HRR1 (31 ± 6.49 vs. 36.10 ± 7.78; p = 0.004). The ratio of these indices to peak HR was also significantly lower with SD (HRR%30 8.04 ± 4.26 vs. 10.19 ± 3.21; p = 0.025 and HRR%1: 18.66 ± 4.43 vs. 20.98 ± 4.72; p = 0.013). The difference in other indices of HRR was not significant.
  
  
  CONCLUSIONS
  Our findings suggest that SD blunts cardiovascular autonomic response, and consequences of this relation might be more pronounced in subjects who are exposed to sleeplessness regularly or in subjects with baseline cardiovascular disease.
authors.affiliation: Department of Cardiology, Marmara University Faculty of Medicine, Pendik, Istanbul, Turkey, acincin@yahoo.com.
authors.forename: Altug
authors.initials: A
authors.lastname: Cincin
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Sari
authors.forename: Mustafa
authors.initials: M
authors.lastname: Oğuz
authors.forename: Sena
authors.initials: S
authors.lastname: Sert
authors.forename: Mehmet
authors.initials: M
authors.lastname: Bozbay
authors.forename: Halil
authors.initials: H
authors.lastname: Ataş
authors.forename: Beste
authors.initials: B
authors.lastname: Ozben
authors.forename: Kursat
authors.initials: K
authors.lastname: Tigen
authors.forename: Yelda
authors.initials: Y
authors.lastname: Basaran
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D012016:Reference Values; D012892:Sleep Deprivation / Q000503:physiopathology*; D055815:Young Adult