title: The Effects of Recombinant Human Insulin-Like Growth Factor-I/Insulin-Like Growth Factor Binding Protein-3 Administration on Body Composition and Physical Fitness in Recreational Athletes.
abstract: BACKGROUND
  IGF-I is thought to mediate many of the anabolic actions of GH, and there are anecdotal reports that IGF-I is misused by elite athletes. There is no published evidence regarding the effects of IGF-I administration on athletic performance.
  
  
  OBJECTIVE
  The objective of the study was to investigate the effects of IGF-I administration on body composition and physical fitness in recreational athletes.
  
  
  METHODS
  This was a randomized, double-blind, placebo-controlled recombinant human (rh) IGF-I/rhIGF binding protein (IGFBP)-3 administration study at Southampton General Hospital (Southampton, United Kingdom).
  
  
  METHODS
  Fifty-six recreational athletes (30 men, 26 women) participated in the study.
  
  
  METHODS
  Participants were randomly assigned to receive placebo, low-dose rhIGF-I/rhIGFBP-3 (30 mg/d), or high dose rhIGF-I/rhIGFBP-3 (60 mg/d) for 28 days. Body composition (assessed by dual energy x-ray absorptiometry) and cardiorespiratory fitness (assessed by incremental treadmill test) were measured before and immediately after treatment. Within-individual changes after treatment were analyzed using paired t tests.
  
  
  RESULTS
  There were no significant changes in body fat mass or lean body mass in women or men after the administration of the rhIGF-I/rhIGFBP-3 complex. There was a significant increase in maximal oxygen consumption (VO2 max) after treatment. When women and men and low- and high-dose treatment groups were combined, mean VO2 max increased by approximately 7% (P = .001). No significant change in VO2 max was observed in the placebo group.
  
  
  CONCLUSIONS
  rhIGF-I/rhIGFBP-3 administration for 28 days improves aerobic performance in recreational athletes, but there are no effects on body composition.
authors.affiliation: Human Development and Health Academic Unit (N.G., S.P.N., M.F., J.A.W., P.H.S., R.I.G.H.), Faculty of Medicine, University of Southampton SO16 6YD, and University Hospital Southampton, National Health Service Foundation Trust SO16 6YD, and Southampton Statistical Sciences Research Institute (D.B.), University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Nishan
authors.initials: N
authors.lastname: Guha
authors.affiliation: Human Development and Health Academic Unit (N.G., S.P.N., M.F., J.A.W., P.H.S., R.I.G.H.), Faculty of Medicine, University of Southampton SO16 6YD, and University Hospital Southampton, National Health Service Foundation Trust SO16 6YD, and Southampton Statistical Sciences Research Institute (D.B.), University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Nevitt
authors.affiliation: Human Development and Health Academic Unit (N.G., S.P.N., M.F., J.A.W., P.H.S., R.I.G.H.), Faculty of Medicine, University of Southampton SO16 6YD, and University Hospital Southampton, National Health Service Foundation Trust SO16 6YD, and Southampton Statistical Sciences Research Institute (D.B.), University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Francis
authors.affiliation: Human Development and Health Academic Unit (N.G., S.P.N., M.F., J.A.W., P.H.S., R.I.G.H.), Faculty of Medicine, University of Southampton SO16 6YD, and University Hospital Southampton, National Health Service Foundation Trust SO16 6YD, and Southampton Statistical Sciences Research Institute (D.B.), University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: John A
authors.initials: JA
authors.lastname: Woodland
authors.affiliation: Human Development and Health Academic Unit (N.G., S.P.N., M.F., J.A.W., P.H.S., R.I.G.H.), Faculty of Medicine, University of Southampton SO16 6YD, and University Hospital Southampton, National Health Service Foundation Trust SO16 6YD, and Southampton Statistical Sciences Research Institute (D.B.), University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Dankmar
authors.initials: D
authors.lastname: Böhning
authors.affiliation: Human Development and Health Academic Unit (N.G., S.P.N., M.F., J.A.W., P.H.S., R.I.G.H.), Faculty of Medicine, University of Southampton SO16 6YD, and University Hospital Southampton, National Health Service Foundation Trust SO16 6YD, and Southampton Statistical Sciences Research Institute (D.B.), University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Sönksen
authors.affiliation: Human Development and Health Academic Unit (N.G., S.P.N., M.F., J.A.W., P.H.S., R.I.G.H.), Faculty of Medicine, University of Southampton SO16 6YD, and University Hospital Southampton, National Health Service Foundation Trust SO16 6YD, and Southampton Statistical Sciences Research Institute (D.B.), University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Richard I G
authors.initials: RI
authors.lastname: Holt
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001823:Body Composition / Q000187:drug effects*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000008:administration & dosage / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010809:Physical Fitness; D010919:Placebos; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D011998:Recreation / Q000502:physiology; D055815:Young Adult
chemical_list: C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D010919:Placebos; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I