title: The associations among GNB3 C825T polymorphism, erectile dysfunction, and related risk factors.
abstract: BACKGROUND
  Vascular etiologies are the most common risk factors for erectile dysfunction (ED). Published studies have reported the associations of GNB3 C825T polymorphism with many vascular diseases. However, there are few reports about the association between this gene polymorphism and ED.
  
  
  OBJECTIVE
  To investigate the associations among GNB3 C825T polymorphism, ED, and related risk factors in Taiwanese subjects.
  
  
  METHODS
  A total of 155 patients with ED and 81 healthy controls were enrolled. All men had complete clinical histories taken. The 5-item International Index of Erectile Function (IIEF-5) was used to assess erectile conditions. The GNB3 C825T polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism method.
  
  
  METHODS
  Patients with ED were defined as those having an IIEF-5 of <21.
  
  
  RESULTS
  Two hundred thirty-six men were enrolled with a mean (standard deviation) age of 59.0 (10.2) years. Diabetes mellitus (DM), hypertension, and age were the three most significant independent risk factors for ED in a multiple logistic regression analysis (P = 0.008, 0.003, and 0.007, respectively). The prevalence of DM, hypertension, and body mass index (BMI) was significantly higher in GNB3 825T allele (CT/TT) carriers (P = 0.023, 0.049, and 0.035, respectively). There was no significant difference of ED prevalence between T and C allele carriers (69.1% vs. 56.2%, P = 0.07). However, the T allele carriers had significantly lower IIEF-5 scores (P = 0.02) associated with an increment of the T allele number (16.4[CC] vs. 14.4[CT] vs. 13.2[TT], P = 0.04).
  
  
  CONCLUSIONS
  In the present study, DM, hypertension, and BMI had significant associations with GNB3 825T allele carriers. Our results failed to show a significant association of the GNB3 C825T polymorphisms with ED prevalence. However, we cannot exclude that the presence of the T allele might influence the risk for ED severity indirectly through an increased risk for some vascular diseases.
authors.affiliation: Department of Urology, Kaohsiung Medical University Hospital, Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Yung-Chin
authors.initials: YC
authors.lastname: Lee
authors.forename: Hui-Hui
authors.initials: HH
authors.lastname: Lin
authors.forename: Chii-Jye
authors.initials: CJ
authors.lastname: Wang
authors.forename: Chia-Chu
authors.initials: CC
authors.lastname: Liu
authors.forename: Wen-Jeng
authors.initials: WJ
authors.lastname: Wu
authors.forename: Chun-Hsiung
authors.initials: CH
authors.lastname: Huang
authors.forename: Lin-Li
authors.initials: LL
authors.lastname: Chang
mesh_terms: D000483:Alleles; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000150:complications / Q000453:epidemiology; D007172:Erectile Dysfunction / Q000453:epidemiology / Q000235:genetics*; D006580:Genetic Carrier Screening; D005838:Genotype; D020962:Heterotrimeric GTP-Binding Proteins / Q000235:genetics*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000453:epidemiology; D012150:Polymorphism, Restriction Fragment Length / Q000235:genetics*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D013739:Testosterone / Q000097:blood
chemical_list: C454420:G-protein beta3 subunit; D013739:Testosterone; D020962:Heterotrimeric GTP-Binding Proteins