title: Serum testosterone levels after cardiac transplantation.
abstract: BACKGROUND
  Men undergoing heart transplantation during the early 1990s had declines in testosterone associated with rapid bone loss. It is unclear whether low testosterone still occurs in an era of lower prednisone doses, whether cyclosporine A (CsA) contributes, whether hypothalamic-pituitary-gonadal (HPG) suppression or direct testicular effects are responsible, and whether low testosterone influences bone loss in men receiving therapy to prevent osteoporosis.
  
  
  METHODS
  Serum testosterone, estradiol, sex hormone binding globulin, gonadotropins, and bone density were measured and prednisone and CsA doses and levels for the first 2 years after transplantation were recorded in a more recently transplanted cohort of 108 participants in a trial comparing alendronate and calcitriol for prevention of posttransplant osteoporosis.
  
  
  RESULTS
  Total and free testosterone levels were lowest during the first month (257+/-131 and 6.2+/-3 ng/dL, respectively) and normalized by 2 months. Gonadotropins were low in the majority, suggesting HPG suppression. Low total testosterone persisted in 14% at 1 year and 18% at 2 years. Prednisone was the major predictor of serum testosterone. No adverse effect of CsA and no relationship between serum testosterone and bone density change were detected.
  
  
  CONCLUSIONS
  Low serum testosterone levels still occur in the early posttransplant period, probably related to HPG suppression by prednisone rather than direct testicular effects of CsA. They are not associated with bone loss in men receiving therapies to prevent osteoporosis. At later time points, low testosterone levels are common and apparently related to primary gonadal dysfunction, suggesting that long-term male heart transplant recipients should be evaluated for hypogonadism.
authors: Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
authors: Jessica
authors: J
authors: Fleischer
authors: Donald J
authors: DJ
authors: McMahon
authors: Wylie
authors: W
authors: Hembree
authors: Vicki
authors: V
authors: Addesso
authors: Christopher
authors: C
authors: Longcope
authors: Elizabeth
authors: E
authors: Shane
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015519:Bone Density; D005006:Ethnicity; D005640:Follicle Stimulating Hormone / Q000097:blood; D005500:Follow-Up Studies; D016027:Heart Transplantation / Q000502:physiology*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D044469:Racial Groups; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone