title: Male sexual function can be maintained without aromatization: randomized placebo-controlled trial of dihydrotestosterone (DHT) in healthy, older men for 24 months.
abstract: BACKGROUND
  Male sexual function is highly androgen dependent but whether aromatization of testosterone (T) to estradiol is required remains contentious.
  
  
  OBJECTIVE
  This study aims to investigate the effects of selective estrogen deficiency induced by a nonaromatizable androgen, dihydrotestosterone (DHT), on sexual function of healthy middle-aged and older men.
  
  
  METHODS
  Randomized clinical trial of daily transdermal DHT (70 mg) or placebo gel treatment in 114 healthy middle-aged and older (>50 years, mean 60.5 years) men without known prostate disease maintaining selective estrogen deficiency for 24 months.
  
  
  METHODS
  The end points were responses to a psychosexual and mood questionnaire completed before, at 3 months, then at 6 monthly intervals during and 3 months after study. Data were analyzed by mixed model analysis of variance for repeated measures using age and body mass index (BMI) as covariates and including interactions of treatment with age and time-on-study.
  
  
  RESULTS
  DHT treatment increased serum DHT with complete suppression of serum T, luteinizing hormone, follicle stimulating hormone, and estradiol throughout the 24-month study resulting in reduced spinal bone density. There were no spontaneous complaints, or discontinuations for, adverse effects on sexual function during the study. DHT administration had no effects on any of 33 measures of sexual function and mood, apart from a mild, but significant decrease in overall sexual desire, which was reversible after cessation of treatment. Increasing age and less often increasing BMI were associated with significant decreases in most aspects of sexual function.
  
  
  CONCLUSIONS
  We conclude that aromatization plays only a minimal role in maintenance of sexual function in healthy eugonadal middle-aged or older men, but age and obesity are significantly associated with decreases in most aspects of self-reported sexual function and satisfaction. The dependence of male sexual function on aromatization may be conditional on age and obesity and can be overcome by a nonaromatizable androgen.
authors.affiliation: Andrology Department, Concord Hospital, Sydney, NSW, Australia; ANZAC Research Institute, University of Sydney, Sydney, NSW, Australia.
authors.forename: Gideon A
authors.initials: GA
authors.lastname: Sartorius
authors.forename: Lam P
authors.initials: LP
authors.lastname: Ly
authors.forename: David J
authors.initials: DJ
authors.lastname: Handelsman
mesh_terms: D000279:Administration, Cutaneous; D000368:Aged; D000728:Androgens / Q000008:administration & dosage / Q000494:pharmacology*; D015992:Body Mass Index; D013196:Dihydrotestosterone / Q000008:administration & dosage / Q000494:pharmacology*; D004311:Double-Blind Method; D004958:Estradiol / Q000378:metabolism; D006801:Humans; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D019529:Sexuality / Q000502:physiology*; D013739:Testosterone / Q000378:metabolism*
chemical_list: D000728:Androgens; D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone
keywords: Age; Androgen; Aromatase; Aromatization; DHT; Men; Obesity; Sexual Function; Testosterone