title: Normal voiding patterns assessed by means of a frequency-volume chart.
abstract: OBJECTIVE
  Voiding dysfunction is one of the commonest problems among the elderly. This study aimed to elucidate the mechanisms behind the diurnal and nocturnal urine output patterns in young and elderly male volunteers. Of particular interest was bladder reservoir function during the day and night.
  
  
  METHODS
  Young males (n=25; median age 25.0 years; range 22-32 years) and elderly males (n=18; median age 61.1 years; range 55-73 years) were included in the study. Their voiding habits were assessed from a 3-day frequency-volume chart (FVC) detailing all fluid intake and urine output. Data on voided volume, voiding frequency, maximum voided volume (MVV) and average voided volume (AVV) were obtained from the FVC.
  
  
  RESULTS
  The young males' average fluid intake was significantly higher than that of the elderly males. On average the elderly males had a slightly higher voiding frequency than the young males, although this was not statistically significant. There was no difference between the two groups regarding their AVVs at night (including the first morning void). The MVVs of the young and elderly males were significantly different, whereas the ratio between voided volume and MVV did not differ between the groups.
  
  
  CONCLUSIONS
  The main finding was that young and elderly males void with equal average volumes of urine at night (first morning void inclusive), whereas the elderly void with smaller volumes than the young during the day-time. The elderly thus seem to have the capacity to adjust their AVV to night-time urine output size.
authors.affiliation: Institute of Clinical Medicine, University Hospital of Aarhus, Skejby Sygehus, Aarhus, Denmark. graugaard@ki.au.dk
authors.forename: Charlotte
authors.initials: C
authors.lastname: Graugaard-Jensen
authors.forename: Frank
authors.initials: F
authors.lastname: Schmidt
authors.forename: Henrik Frederik
authors.initials: HF
authors.lastname: Thomsen
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Djurhuus
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D001743:Urinary Bladder / Q000502:physiology*; D014554:Urination / Q000502:physiology*