title: The Effect of Oral Phosphodiesterase-5 Inhibitors on Sperm Parameters: A Meta-analysis and Systematic Review.
abstract: OBJECTIVE
  To perform a systematic review and meta-analysis to evaluate the effect of phosphodiesterase-5 (PDE5) inhibitors on sperm parameters.
  
  
  METHODS
  A systematic literature search was performed. Mean value and its standard deviation (mean ± standard deviation) were used to perform quantitative analysis. Statistic heterogeneity scores were assessed with the standard Cochran Q test and I2statistic. All statistical analyses were conducted by RevMan 5.3.
  
  
  RESULTS
  Eleven studies embraced a total of 1317 participants and 19 subgroups or trials were included. Acute administration of PDE5 inhibitors had no effect on semen volume (mean value [MD] = 0.26; 95% confidence interval [CI]: 0.00-0.48) and sperm concentration (MD = 2.04; 95%CI: -2.95 to 7.04). However, the percentage of motile spermatozoa (MD = 7.05; 95%CI: 2.59-11.51), the percentage of total progressive motility (MD = 6.23; 95%CI: 2.43-10.04), and rapid progressive motility (MD = 3.11; 95%CI: 0.23-5.99) were increased after oral PDE5 inhibitors treatment. Interestingly, these significant changes were observed only in infertile men but not in normal patients (MD = 6.89, P < .001 vs MD = 0.67, P = .71; MD = 6.64, P = .001 vs MD = 2.11, P > .05; and MD = 3.89, P = .04 vs MD = 0.92, P = .59, respectively). The percentage of morphologically normal spermatozoa also increased in infertile men (MD = 12.15; 95%CI: 5.16-19.15). Limited evidence showed the linearity, abnormal forms of spermatozoa, as well as reproductive hormones (total testosterone, free testosterone, luteinizing hormone, and follicle-stimulating hormone) did not benefit from PDE5 inhibitors treatment.
  
  
  CONCLUSIONS
  Oral PDE5 inhibitors treatment could modestly increase the sperm motility and morphology in infertile men.
authors.affiliation: Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Tan
authors.affiliation: Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Liangren
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Shiyou
authors.initials: S
authors.lastname: Wei
authors.affiliation: Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China. Electronic address: uro_weiqiang@163.com.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wei
mesh_terms: D000284:Administration, Oral; D006801:Humans; D008297:Male; D058986:Phosphodiesterase 5 Inhibitors / Q000494:pharmacology*; D000068677:Sildenafil Citrate / Q000494:pharmacology; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects*; D000068581:Tadalafil / Q000494:pharmacology; D000069058:Vardenafil Dihydrochloride / Q000494:pharmacology
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D000069058:Vardenafil Dihydrochloride; D000068581:Tadalafil; D000068677:Sildenafil Citrate