title: Normal variation and influence of stress, caffeine intake, and sexual activity on uroflowmetry parameters of a middle-aged asymptomatic cohort of volunteer male urologists.
abstract: OBJECTIVE
  To assess normal variations of uroflowmetry in middle-aged asymptomatic male urologists and to analyse the influence of stress, caffeine intake, and sexual activity.
  
  
  METHODS
  Thirty-one male urologists from Quebec and Ontario were recruited for this study. All were healthy, not taking any current medications known to interfere with lower urinary tract function, and symptom-free (International Prostate Symptom Score less than 5). Each received two identical flowmeters to keep over a period of 2 weeks, one at home and one in his busiest office. Ten uroflow tracings, with a volume greater than 150 mL, were requested from each of them; five at home and five in the office. A total of 310 flows were analysed. The subjective level of stress, coffee intake, and sexual activity, in the hour before each uroflowmetrogram, was recorded, through a short self-administered questionnaire and stress visual scale.
  
  
  RESULTS
  are presented as an average per individual. The voided volume was 331.9 mL, with an SD of 94.8 mL. The voiding time was 32.7 seconds (SD=15.5). The peak flow rate was 20.5 mL/sec (SD=3.9), the mean flow rate was 14.3 mL/sec (SD=3.0), and the time to maximum flow was 7.2 sec (SD=4.0). Subjective levels of stress did not significantly change these parameters. Uroflows were obtained with and without coffee drinking. The voided volume was 337.4 mL (SD=109.2) vs. 290.8 mL (SD=77.3) (P=0.03), and peak flow rate 19.4 mL/sec (SD=4.1) vs. 18.9 mL/sec (SD=3.1) (P=0.49), respectively.
  
  
  CONCLUSIONS
  Uroflowmetry parameters and voided volume are highly variable in a normal asymptomatic population. Subjective stress level does not seem to have an influence on these parameters. Coffee intake significantly increases the voided volume but does not change the peak flow rate. These conclusions should be considered when using uroflowmetry parameters as an outcome measure.
authors.affiliation: Department of Urology and Centre for Clinical Epidemiology, Jewish General Hospital, McGill University, Montreal, Canada. cohen972@med.mcgill.ca
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Cohen
authors.forename: Jordan R
authors.initials: JR
authors.lastname: Steinberg
authors.forename: Michel
authors.initials: M
authors.lastname: Rossignol
authors.forename: Jeremy
authors.initials: J
authors.lastname: Heaton
authors.forename: Jacques
authors.initials: J
authors.lastname: Corcos
mesh_terms: D000328:Adult; D002110:Caffeine / Q000494:pharmacology*; D015331:Cohort Studies; D003075:Coitus / Q000502:physiology*; D004231:Diuresis / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010820:Physicians; D013312:Stress, Physiological / Q000503:physiopathology*; D014563:Urodynamics; D014572:Urology
chemical_list: D002110:Caffeine