title: Resistance training and testosterone levels in male patients with chronic kidney disease undergoing dialysis.
abstract: BACKGROUND
  We investigated serum testosterone and insulin-like growth factor 1 (IGF-1) levels' associations with muscle fibre size and resistance training in male dialysis patients.
  
  
  METHODS
  Male patients were included in a 16-week control period followed by 16 weeks of resistance training thrice weekly. Blood samples were obtained to analyse testosterone, luteinizing hormone (LH), IGF-1, and IGF-binding protein 3. Muscle fibres' size was analysed in biopsies from m. vastus lateralis.
  
  
  RESULTS
  The patients' testosterone levels were within the normal range at baseline (n = 20) (19.5 (8.2-52.1) nmol/L versus 17.6 (16.1-18.0), resp.) whereas LH levels were higher (13.0 (5.5-82.8) U/L versus 4.3 (3.3-4.6), P < 0.001, resp.). IGF-1 and IGF-binding protein 3 levels were higher in the patients compared with reference values (203 (59-590) ng/mL versus 151 (128-276), P = 0.014, and 5045 (3370-9370) ng/mL versus 3244 (3020-3983), P < 0.001, resp.). All hormone levels and muscle fibre size (n = 12) remained stable throughout the study. Age-adjusted IGF-1 was associated with type 1 and 2 fibre sizes (P < 0.05).
  
  
  CONCLUSIONS
  Patients' total testosterone values were normal due to markedly increased LH values, which suggest a compensated primary insufficiency of the testosterone producing Leydig cell. Even though testosterone values were normal, resistance training was not associated with muscle hypertrophy. This trial is registered with ISRCTN72099857.
authors.affiliation: Department of Cardiology, Nephrology & Endocrinology, Nordsjællands University Hospital, Dyrehavevej 29, Opg. 52C Plan 4, 3400 Hillerød, Denmark.
authors.forename: Stig
authors.identifier: 0000-0002-9214-046X
authors.initials: S
authors.lastname: Molsted
authors.affiliation: Institute of Sports Medicine Copenhagen, Bispebjerg University Hospital, Bispebjerg Bakke 23, 2400 Copenhagen NV, Denmark.
authors.forename: Jesper L
authors.initials: JL
authors.lastname: Andersen
authors.affiliation: Department of Nephrology P, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen Ø, Denmark.
authors.forename: Inge
authors.initials: I
authors.lastname: Eidemak
authors.affiliation: Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, Copenhagen University, Grønnegårdsvej 15, 1870 Frederiksberg C, Denmark.
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Harrison
authors.affiliation: University Department of Growth and Reproduction, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen Ø, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Jørgensen
mesh_terms: D000328:Adult; D000368:Aged; D015444:Exercise; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000378:metabolism* / Q000473:pathology; D009929:Organ Size; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000473:pathology; D013739:Testosterone / Q000097:blood*
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D013739:Testosterone; D007334:Insulin-Like Growth Factor I