title: Testosterone supplementation for erectile dysfunction: results of a meta-analysis.
abstract: OBJECTIVE
  To our knowledge a causal relationship between altered levels of androgens and erectile dysfunction has not yet been established. We reviewed the literature to assess the usefulness of androgen replacement for erectile dysfunction.
  
  
  METHODS
  Meta-analysis was chosen as the method of evaluating the literature. Study inclusion criteria were testosterone given as the only therapy for erectile dysfunction and a clearly stated definition of response for evaluating treatment success or failure.
  
  
  RESULTS
  We evaluated 73 articles obtained by a MEDLINE search of 1966 to 1998 and included 16 in our study. The overall response rate was 57%. In the 9 series with response rate by etiology patients with primary versus secondary testicular failure had a response rate of 64% versus 44% (p <0.001). Intramuscular and oral methods of delivery were equivalent with a response rate of 51.3% and 53.2%, respectively. However, the response to transdermal therapy was significantly different from that of intramuscular and oral treatment (80.9% versus 51.3% and 53.2%, respectively, p <0.001). The mean confidence level response for testosterone treatment was 16. 7% in the placebo and 65.4% in the treated group (p <0.0001).
  
  
  CONCLUSIONS
  Our meta-analysis of the usefulness of androgen replacement therapy for erectile dysfunction indicates that the response rate for a primary etiology was improved over that for a secondary etiology, transdermal testosterone therapy was more effective than intramuscular or oral treatment, and intramuscular and oral treatments were equivalent. In addition, there was a statistically significant difference in favor of testosterone over placebo, implying a role for supplementation in select groups.
authors.affiliation: Departments of Urology and Preventive Medicine, Northwestern University Medical School, Chicago, Illinois, USA.
authors.forename: P
authors.initials: P
authors.lastname: Jain
authors.forename: A W
authors.initials: AW
authors.lastname: Rademaker
authors.forename: K T
authors.initials: KT
authors.lastname: McVary
mesh_terms: D000284:Administration, Oral; D007172:Erectile Dysfunction / Q000188:drug therapy*; D020249:Hormone Replacement Therapy; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D013739:Testosterone / Q000008:administration & dosage*
chemical_list: D013739:Testosterone