title: Body composition and muscle strength in healthy men receiving testosterone enanthate for contraception.
abstract: To determine the effect of androgens on body composition and muscle strength, we measured fat-free mass (kg), fat mass (kg), and bone density (g/cm2) by dual x-ray absorptiometry, and muscle strength (Newton meters) by dynamometry in a controlled, prospective study involving 13 nonathletic men receiving testosterone enanthate 200 mg/week in for 6 months and 8 healthy controls. Biochemical markers of bone turnover were measured in the treated subjects at baseline and 6 months. In the treated subjects at 6 months, fat-free mass (mean +/- SEM) increased by 9.6 +/- 1.0% (P < or = 0.01) whereas fat mass decreased by 16.2 +/- 6.7% (P < or = 0.05). Changes in muscle strength ranged from -1.6-19.2%. Only hip adduction increased 19.2 +/- 9.5% (P < 0.05). Changes in bone density ranged from -1.3-5.2%, decreasing significantly at one site and increasing significantly at four of the nine sites measured (P < 0.05). Serum testosterone increased by 91.1 +/- 7.5% (P < 0.01), and testicular volume decreased by 24.0 +/- 3.2% (P < 0.01). Serum osteocalcin increased by 35.7 +/- 17.3% (P < 0.05), serum immunoreactive PTH (iPTH) increased by 41.4 +/- 15.1% (P < 0.05), serum calcium decreased by 2.3 +/- 1.0% (P < 0.05), and serum albumin decreased by 4.5 +/- 1.7% (P < 0.05). There were no detectable changes in fat-free mass, fat mass, muscle strength, or bone density in controls. The administration of testosterone enanthate in pharmacological doses for 6 months resulted in a modest reduction in fat mass and small increases in fat-free mass, muscle strength, and bone density. These changes do not support the use of androgens for enhancing athletic performance.
authors.affiliation: University of Melbourne, Department of Endocrinology, Austin Hospital, Victoria, Australia.
authors.forename: N R
authors.initials: NR
authors.lastname: Young
authors.forename: H W
authors.initials: HW
authors.lastname: Baker
authors.forename: G
authors.initials: G
authors.lastname: Liu
authors.forename: E
authors.initials: E
authors.lastname: Seeman
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers; D001823:Body Composition / Q000187:drug effects*; D015519:Bone Density / Q000187:drug effects; D002118:Calcium / Q000097:blood; D003272:Contraceptive Agents, Male / Q000493:pharmacokinetics / Q000494:pharmacology*; D003404:Creatinine / Q000652:urine; D006801:Humans; D006909:Hydroxyproline / Q000652:urine; D008297:Male; D009132:Muscles / Q000187:drug effects* / Q000502:physiology; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D011446:Prospective Studies; D012044:Regression Analysis; D012709:Serum Albumin / Q000032:analysis; D013739:Testosterone / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D003272:Contraceptive Agents, Male; D010281:Parathyroid Hormone; D010710:Phosphates; D012709:Serum Albumin; D015675:Osteocalcin; D013739:Testosterone; C004648:testosterone enanthate; D003404:Creatinine; D000469:Alkaline Phosphatase; D006909:Hydroxyproline; D002118:Calcium