title: Serum reference value of two potential doping candidates-myostatin and insulin-like growth factor-I in the healthy young male.
abstract: BACKGROUND
  Myostatin negatively regulates muscle growth, and its inhibition by suitable proteins can increase muscle bulk and exercise performance. However, the reference values of serum myostatin in athletes performing strength training are still lacking.
  
  
  METHODS
  A cross-sectional study recruiting28 male collegiate athletes performing strength training and 29 age-matched normal controls was conducted. The serum concentration of myostatin and insulin-like growth factor 1 (IGF-1), grip strength, and body composition were the main outcome measures. We used regression models to analyze the correlation between serum markers and the physiological parameters. The athlete group had greater height, weight, body mass index (BMI), fat mass percentage, fat-free mass, muscle mass, waist girth, grip strength, and estimated daily energy expenditure.
  
  
  RESULTS
  The IGF-1 concentration was higher in the athlete group (324 ± 80 vs. 263 ± 134 ng/ml), but the myostatin levels did not differ (12.1 ± 3.7 vs. 12.4 ± 3.5 ng/ml). The reference value for IGF-1 among the healthy young males was 293 ± 114 ng/ml, correlated with age and height; the value for myostatin was 12.3 ± 3.6 ng/ml, correlated negatively with BMI, fat mass percentage, and waist girth after adjustment for age.
  
  
  CONCLUSIONS
  Myostatin level is negatively related to fat percentage, and serum IGF-1 is positively related to height. The reference values could provide a basis for future doping-related study.
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital BeiHu Branch, Taipei, Taiwan ; Community and Geriatric Medicine Research Center, National Taiwan University Hospital BeiHu Branch, Taipei, Taiwan ; Department of Athletic Training and Health, National Taiwan Sport University, TaoYuan, Taiwan ; Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-Shan South Rd., Taipei, 100 Taiwan.
authors.forename: Der-Sheng
authors.initials: DS
authors.lastname: Han
authors.affiliation: Department of Athletic Training and Health, National Taiwan Sport University, TaoYuan, Taiwan.
authors.forename: Chi-Huang
authors.initials: CH
authors.lastname: Huang
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, No. 7, Chung-Shan South Rd., Taipei, Taiwan ; Department of Physical Medicine & Rehabilitation, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan.
authors.forename: Ssu-Yuan
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-Shan South Rd., Taipei, 100 Taiwan ; Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan ; Center for Developmental Biology & Regenerative Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Wei-Shiung
authors.initials: WS
authors.lastname: Yang
mesh_terms: D015415:Biomarkers / Q000097:blood*; D001823:Body Composition; D003430:Cross-Sectional Studies; D004300:Doping in Sports; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D055435:Myostatin / Q000097:blood*; D012016:Reference Values; D055070:Resistance Training; D055815:Young Adult
chemical_list: D015415:Biomarkers; D055435:Myostatin; D007334:Insulin-Like Growth Factor I
keywords: Biomarker; Doping; Exercise; Fat-free mass; Reference value