title: Frequency of sexual activity and prostatic health: fact or fairy tale?
abstract: OBJECTIVE
  To evaluate whether the symptoms associated with benign prostatic hyperplasia can be aggravated by infrequent sex, which has been suggested historically, using cross-sectional data from the Olmsted County Study of Urinary Symptoms and Health Status Among Men.
  
  
  METHODS
  In 1989 and 1990, 2115 white men between the ages of 40 and 79 years were recruited from a random sample of Olmsted County residents (55% participation rate). During follow-up, these men completed a self-administered questionnaire that assessed lower urinary tract symptom severity, and 81% reported the frequency of ejaculation during the previous month.
  
  
  RESULTS
  Overall, men who reported ejaculating at least once a week were less likely to have moderate to severe (International Prostate Symptom Score greater than 7) symptoms than men reporting no ejaculations (odds ratio 0.62, 95% confidence interval 0.51 to 0.75). The dose-response relation was strong, with men who reported more frequent ejaculations having the lowest prevalence of moderate to severe symptoms. Similar associations were seen for peak urinary flow rates, prostate volume, and health-related quality of life. The associations with urologic measures did not exist within the age decade, however. Thus, after adjusting for age, the odds ratio for ejaculation frequency and symptom severity was 0.99 (95% confidence interval 0.79 to 1.24) and was similar for peak urinary flow rates and prostate volume.
  
  
  CONCLUSIONS
  These cross-sectional data suggest that the frequency of ejaculation has no effect on lower urinary tract symptoms, peak urinary flow rates, or prostate volume; the apparent protective association appears to be an artifact caused by the confounding effects of age.
authors.affiliation: Department of Health Sciences Research, Division of Epidemiology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Jacobsen
authors.forename: Debra J
authors.initials: DJ
authors.lastname: Jacobson
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Rohe
authors.forename: Cynthia J
authors.initials: CJ
authors.lastname: Girman
authors.forename: Rosebud O
authors.initials: RO
authors.lastname: Roberts
authors.forename: Michael M
authors.initials: MM
authors.lastname: Lieber
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004542:Ejaculation / Q000502:physiology; D006304:Health Status; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010549:Personal Satisfaction; D015995:Prevalence; D011467:Prostate / Q000502:physiology*; D011469:Prostatic Diseases / Q000175:diagnosis / Q000453:epidemiology; D011470:Prostatic Hyperplasia / Q000175:diagnosis* / Q000453:epidemiology; D011788:Quality of Life; D012725:Sexual Behavior / Q000502:physiology*; D014555:Urination Disorders / Q000175:diagnosis / Q000453:epidemiology; D014563:Urodynamics / Q000502:physiology