title: Sex Hormones Predict the Incidence of Erectile Dysfunction: From a Population-Based Prospective Cohort Study (FAMHES).
abstract: BACKGROUND
  The decline of testosterone has been known to be associated with the prevalence of erectile dysfunction (ED), but the causal relationship between sex hormones and ED is still uncertain.
  
  
  OBJECTIVE
  To prove the association between sex hormones and ED, we carried out a prospective cohort study based on our previous cross-sectional study.
  
  
  METHODS
  We performed a prospective cohort study of 733 Chinese men who participated in Fangchenggang Area Males Health and Examination Survey from September 2009 to December 2009 and were followed for 4 years. Erectile function was estimated by scores of the five-item International Index of Erectile Dysfunction (IIEF-5) and relative ratios (RRs) were estimated using the Cox proportional hazards regression model.
  
  
  METHODS
  Data were collected at follow-up visit and included sex hormone measurements, IIEF-5 scores, physical examination, and health questionnaires.
  
  
  RESULTS
  Men with the highest tertile of free testosterone (FT) (RR = 0.21, 95% confidence interval [CI]: 0.09-0.46) and the lowest tertile of sex hormone-binding globulin (SHBG) (RR = 0.38, 95% CI: 0.19-0.73) had decreased risk of ED. In young men (aged 21-40), a decreased risk was observed with the increase of FT and bioavailable testosterone (BT) (adjusted RR and 95% CI: 0.78 [0.67-0.92] and 0.75 [0.62-0.95], respectively). Total testosterone (TT) (RR = 0.89, 95% CI: 0.81-0.98) was inversely associated with ED after adjusting for SHBG, while SHBG (RR = 1.04, 95% CI: 1.02-1.06) remained positively associated with ED after further adjusting for TT. Men with both low FT and high SHBG had highest ED risk (adjusted RR = 4.61, 95% CI: 1.33-16.0).
  
  
  CONCLUSIONS
  High FT and BT levels independently predicted a decreased risk of ED in young men. Further studies are urgently needed to clarify the molecular mechanisms of testosterone acting on ED.
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.
authors: Yawen
authors: Y
authors: Luo
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.|Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China.
authors: Haiying
authors: H
authors: Zhang
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.|Institute of Urology and Nephrology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.
authors: Ming
authors: M
authors: Liao
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.
authors: Qin
authors: Q
authors: Tang
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.
authors: Yuzhen
authors: Y
authors: Huang
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.
authors: Jinling
authors: J
authors: Xie
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.
authors: Yan
authors: Y
authors: Tang
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Department of Chemotherapy, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China.
authors: Aihua
authors: A
authors: Tan
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.
authors: Yong
authors: Y
authors: Gao
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Institute of Urology and Nephrology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.
authors: Zheng
authors: Z
authors: Lu
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.
authors: Ziting
authors: Z
authors: Yao
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.
authors: Yonghua
authors: Y
authors: Jiang
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.
authors: Xinggu
authors: X
authors: Lin
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Department of Urology, First Affiliated Hospital of Xinxiang Medical College, Xinxiang, Henan Province, China.
authors: Chunlei
authors: C
authors: Wu
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China.
authors: Xiaobo
authors: X
authors: Yang
authors: Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China.|Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi, China.|Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, China.|Institute of Urology and Nephrology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.
authors: Zengnan
authors: Z
authors: Mo
mesh_terms: D000328:Adult; D000728:Androgens / Q000097:blood*; D044466:Asian People / Q000706:statistics & numerical data; D002681:China; D003430:Cross-Sectional Studies; D007172:Erectile Dysfunction / Q000097:blood* / Q000453:epidemiology* / Q000209:etiology; D012739:Gonadal Steroid Hormones / Q000097:blood; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D011795:Surveys and Questionnaires; D013739:Testosterone / Q000097:blood*
chemical_list: D000728:Androgens; D012739:Gonadal Steroid Hormones; D012738:Sex Hormone-Binding Globulin; D013739:Testosterone
keywords: Cohort Study; Erectile Dysfunction; Sex Hormone-Binding Globulin; Testosterone