title: A prospective study of lower urinary tract symptoms and erectile dysfunction.
abstract: OBJECTIVE
  Several studies have shown that men with lower urinary tract symptoms are more likely to experience erectile dysfunction. All except 1 of these studies were cross-sectional, limiting inferences about whether lower urinary tract symptoms precipitate erectile dysfunction.
  
  
  METHODS
  The association between lower urinary tract symptoms and incident erectile dysfunction was examined prospectively in the Health Professionals Follow-Up Study. Lower urinary tract symptoms were assessed biennially by the American Urological Association symptom index, which captures symptoms of frequency, urgency and force of urinary stream. Severe lower urinary tract symptoms was defined as a symptom score of 20 points or greater and no lower urinary tract symptoms was defined as a score of 7 points or less in men not treated for lower urinary tract symptoms. In 2000 the men were asked to rate erectile function for several periods. Erectile dysfunction was defined as poor or very poor function, or erectile dysfunction medication use, while no erectile dysfunction was defined as very good or good function and no erectile dysfunction medication use. We estimated the RR using Poisson regression, adjusting for age and other potentially confounding factors.
  
  
  RESULTS
  We observed 3,953 incident erectile dysfunction cases among 17,086 men. Men with severe lower urinary tract symptoms in 1994 or earlier had a statistically significant 40% higher risk of erectile dysfunction subsequently than men without lower urinary tract symptoms. The risk of erectile dysfunction increased with increasing lower urinary tract symptom severity (p trend <0.0001). The positive association between lower urinary tract symptoms and erectile dysfunction was stronger in younger than in older men (p interaction = 0.03).
  
  
  CONCLUSIONS
  This study provides evidence that men with lower urinary tract symptoms are more likely to have erectile dysfunction subsequently.
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Alison M
authors.initials: AM
authors.lastname: Mondul
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rimm
authors.forename: Edward
authors.initials: E
authors.lastname: Giovannucci
authors.forename: Dale B
authors.initials: DB
authors.lastname: Glasser
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Platz
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D007172:Erectile Dysfunction / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D053448:Prostatism / Q000150:complications*