title: Testosterone is significantly reduced in endurance athletes without impact on bone mineral density.
abstract: OBJECTIVE
  To compare the basal plasma reproductive hormonal profile in three groups of athletes involved in different training programs, and to define the relationship between androgen level and bone mineral density (BMD) in male athletes.
  
  
  METHODS
  Basal serum total testosterone (TT), free androgen index (FAI), sex hormone-binding globulin (SHBG), cortisol, cortisol to TT ratio, luteinizing hormone (LH), estrogen and BMD were evaluated in cyclists (CY; n = 11), triathletes (TR; n = 14) and swimmers (SW; n = 13) and compared with less active controls (n = 10).
  
  
  RESULTS
  TT and FAI levels were lower (p < 0.05) in CY and TR, whereas the ratio of cortisol to TT was increased in CY only (p < 0.05). No alteration in serum LH, SHBG, estrogen or cortisol concentration was observed. BMD was higher in the proximal femur in TR (p < 0.05). No BMD or hormonal differences were found in SW.
  
  
  CONCLUSIONS
  Only the endurance training of CY and TR induced androgen deficiency without apparent alteration of BMD.
authors.affiliation: Centre Propara, Montpellier, France. laurent.maimoun@oreka.fr
authors.forename: L
authors.initials: L
authors.lastname: Maïmoun
authors.forename: S
authors.initials: S
authors.lastname: Lumbroso
authors.forename: J
authors.initials: J
authors.lastname: Manetta
authors.forename: F
authors.initials: F
authors.lastname: Paris
authors.forename: J L
authors.initials: JL
authors.lastname: Leroux
authors.forename: C
authors.initials: C
authors.lastname: Sultan
mesh_terms: D000328:Adult; D000728:Androgens / Q000097:blood; D001642:Bicycling; D015519:Bone Density; D005269:Femur / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D010807:Physical Endurance; D012420:Running; D013177:Sports; D013550:Swimming; D013739:Testosterone / Q000097:blood*
chemical_list: D000728:Androgens; D013739:Testosterone; D006854:Hydrocortisone