title: Changes in prostate specific antigen in hypogonadal men after 12 months of testosterone replacement therapy: support for the prostate saturation theory.
abstract: OBJECTIVE
  We measured prostate specific antigen after 12 months of testosterone replacement therapy in hypogonadal men.
  
  
  METHODS
  Data were collected from the TRiUS (Testim® Registry in the United States), an observational registry of hypogonadal men on testosterone replacement therapy (849). Participants were Testim naïve, had no prostate cancer and received 5 to 10 gm Testim 1% (testosterone gel) daily.
  
  
  RESULTS
  A total of 451 patients with prostate specific antigen and total testosterone values were divided into group A (197 with total testosterone less than 250 ng/dl) and group B (254 with total testosterone 250 ng/dl or greater). The groups differed significantly in free testosterone and sex hormone-binding globulin, but not in age or prostate specific antigen. In group A but not group B prostate specific antigen correlated significantly with total testosterone (r=0.20, p=0.005), free testosterone (r=0.22, p=0.03) and sex hormone-binding globulin (r=0.59, p=0.002) at baseline. After 12 months of testosterone replacement therapy, increase in total testosterone (mean±SD) was statistically significant in group A (+326±295 ng/dl, p<0.001; final total testosterone 516±28 ng/dl) and group B (+154±217 ng/dl, p<0.001; final total testosterone 513±20 ng/dl). After 12 months of testosterone replacement therapy, increase in prostate specific antigen was statistically significant in group A (+0.19±0.61 ng/ml, p=0.02; final prostate specific antigen 1.26±0.96 ng/ml) but not in group B (+0.28±1.18 ng/ml, p=0.06; final prostate specific antigen 1.55±1.72 ng/ml). The average percent prostate specific antigen increase from baseline was higher in group A (21.9%) than in group B (14.1%). Overall the greatest prostate specific antigen was observed after 1 month of treatment and decreased thereafter.
  
  
  CONCLUSIONS
  Patients with baseline total testosterone less than 250 ng/dl were more likely to have an increased prostate specific antigen after testosterone replacement therapy than those with baseline total testosterone 250 ng/dl or greater, supporting the prostate saturation hypothesis. Clinicians should be aware that severely hypogonadal patients may experience increased prostate specific antigen after testosterone replacement therapy.
authors.affiliation: Scott Department of Urology, Baylor College of Medicine, Houston, Texas 77030, USA. mkhera@bcm.edu
authors.forename: Mohit
authors.initials: M
authors.lastname: Khera
authors.forename: Rajib K
authors.initials: RK
authors.lastname: Bhattacharya
authors.forename: Gary
authors.initials: G
authors.lastname: Blick
authors.forename: Harvey
authors.initials: H
authors.lastname: Kushner
authors.forename: Dat
authors.initials: D
authors.lastname: Nguyen
authors.forename: Martin M
authors.initials: MM
authors.lastname: Miner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020249:Hormone Replacement Therapy; D006801:Humans; D007006:Hypogonadism / Q000097:blood* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D013739:Testosterone / Q000097:blood* / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D013739:Testosterone; D017430:Prostate-Specific Antigen