title: Effect of Shift Work on Nocturia.
abstract: OBJECTIVE
  To identify the circadian sensitive component of nocturia by comparing nocturia in patients who voluntarily choose a disrupted circadian rhythm, that is, shift workers, with those who maintain normal day-night cycles.
  
  
  METHODS
  Between 2011 and 2013, a total of 1741 untreated patients, 1376 nonshift workers and 365 shift workers, were compared for nocturia indices based on frequency volume charts (FVCs). General linear model of 8-hour interval urine production and frequency were compared between FVCs of nonshift workers, FVCs of night-shift workers, and FVCs of day-shift workers.
  
  
  RESULTS
  Nocturia frequency was increased in the night-shift workers (2.38 ± 1.44) compared with nonshift workers (2.18 ± 1.04) (P <.01). Whereas nocturnal polyuria index did not increase significantly (0.33 ± 0.19 for night-shift workers, 0.34 ± 0.13 for nonshift workers, P = .24), nocturnal bladder capacity index increased significantly (1.41 ± 1.06 for night-shift workers, 1.26 ± 0.92 for nonshift workers, P <.01). Eight-hour interval indices show that urine production changed with shift (P <.01), whereas voiding frequency remains unchanged despite shift changes (P = .35).
  
  
  CONCLUSIONS
  Patients in alternating work shifts showed increased nocturia, especially during their night shift. These changes tended to be more associated with decreased nocturnal bladder capacity than increased nocturnal polyuria.
authors.affiliation: Department of Urology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea. Electronic address: jinwook@cau.ac.kr.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Kim
mesh_terms: D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D053158:Nocturia / Q000503:physiopathology*; D012189:Retrospective Studies; D014563:Urodynamics / Q000502:physiology*; D014940:Work Schedule Tolerance; D016526:Workload / Q000706:statistics & numerical data*