title: Asthma and risk of erectile dysfunction--a nationwide population-based study.
abstract: BACKGROUND
  The increased prevalence of erectile dysfunction (ED) has been reported in patients with chronic obstructive pulmonary disease, and sustained systemic inflammation seems to play a central role in this linkage. Asthma is also a chronic inflammatory airway disorder, eliciting a low-grade systemic inflammation; however, the influence of asthma on ED has not been investigated.
  
  
  OBJECTIVE
  Our study strived to explore the relationship of asthma and the subsequent development of ED using a nationwide, population-based database.
  
  
  METHODS
  From 2000 to 2007, we identified newly diagnosed asthma cases involving male patients 18-55 years old. A control cohort without asthma, which was matched for age and comorbidities, was selected for comparison.
  
  
  METHODS
  The two cohorts were followed up, and we observed the occurrence of ED by registry of ED diagnosis in the database.
  
  
  RESULTS
  Of the 17,302 sampled patients (3,466 asthma patients vs. 13,836 control), 114 (0.66%) experienced ED during a mean follow-up period of 4.56 years, including 34 (0.98% of the asthma patients) from the asthma cohort and 80 (0.58%) from the control group. Subjects with asthma experienced a 1.909-fold (95% confidence interval [CI], 1.276-2.856; P=0.002) increase in incident ED, which was independent of age, the number of clinical visits for urologist, and other comorbidities. Kaplan-Meier analysis also revealed the tendency of asthma patients for ED development (log rank test, P=0.002). The risk of ED was higher in cases with more frequent clinical visits for asthma (asthma patients with clinical visits with >24 times/year vs. <12 times/year: hazard ratio [HR]: 4.154 [95% CI:1.392-12.396], P=0.011; clinical visits with 12-24 times/year vs. <12 times/year HR: 3.534 [95% CI:1.245-10.032], P=0.018).
  
  
  CONCLUSIONS
  Asthma may be an independent risk factor for ED, and risk of ED probably increases in accordance with asthma severity.
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Kun-Ta
authors.initials: KT
authors.lastname: Chou
authors.forename: Chin-Chou
authors.initials: CC
authors.lastname: Huang
authors.forename: Yuh-Min
authors.initials: YM
authors.lastname: Chen
authors.forename: Diang-Wang
authors.initials: DW
authors.lastname: Perng
authors.forename: Heng-Sheng
authors.initials: HS
authors.lastname: Chao
authors.forename: Wan-Leong
authors.initials: WL
authors.lastname: Chan
authors.forename: Hsin-Bang
authors.initials: HB
authors.lastname: Leu
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000150:complications* / Q000453:epidemiology*; D002318:Cardiovascular Diseases / Q000150:complications / Q000453:epidemiology; D016022:Case-Control Studies; D015331:Cohort Studies; D006306:Health Surveys; D006801:Humans; D018783:Impotence, Vasculogenic / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013624:Taiwan; D055815:Young Adult