title: Peak muscle mass in young men and sarcopenia in the ageing male.
abstract: CONCLUSIONS
  The prevalence of sarcopenia increases with age. The diagnosis of sarcopenia relies in part on normative data on muscle mass, but these data are lacking. This study provides population-based reference data on muscle mass in young men, and these results may be used clinically for the diagnosis of sarcopenia in men.
  
  
  BACKGROUND
  The ageing population increases the prevalence of sarcopenia. Estimation of normative data on muscle mass in young men during the peak of anabolic hormones is necessary for the diagnosis of sarcopenia in ageing males. The purposes of this study were to provide population-based reference data on lean body mass (LBM) in young men during the time of peak levels of GH/IGF-1 and testosterone and further to apply the reference data on a population-based sample of men aged 60-74 years to estimate the prevalence of sarcopenia.
  
  
  METHODS
  This is a cross-sectional, population-based single-centre study. Our participants are from random selection of 783 men, aged 20-29 years, and 600 men, aged 60-74 years. LBM was assessed by dual-energy X-ray absorptiometry (DXA). LBM T-scores were calculated on the basis of LBM in the young participants. Muscle function in the lower extremities was measured using a leg extension power (LEP) rig in the ageing participants.
  
  
  RESULTS
  Total lean body mass (TLB) was (mean (SD)) 64.7 kg (6.8) in the young and 60.4 kg (6.4) in the ageing men (p<0.001). Lower extremity lean mass (LELB) was 22.0 kg (2.6) in the young and 19.2 kg (2.4) in the ageing men (p<0.001). In the ageing men, TLB and LELB T-scores were -0.64 (0.94) and -1.09 (0.94). A total of 4.8 and 8.5% had a TLB or LELB T-score of less than -2 and a LEP in the lowest quartile.
  
  
  CONCLUSIONS
  This study provides population-based reference data on LBM in men, and these data may be used clinically for the diagnosis of sarcopenia.
authors.affiliation: Department of Endocrinology, Odense University Hospital Odense, DK-5000, Odense C, Denmark, frostnielsen@yahoo.com.
authors.forename: M
authors.initials: M
authors.lastname: Frost
authors.forename: T L
authors.initials: TL
authors.lastname: Nielsen
authors.forename: K
authors.initials: K
authors.lastname: Brixen
authors.forename: M
authors.initials: M
authors.lastname: Andersen
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology; D000886:Anthropometry / Q000379:methods; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D003718:Denmark / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000473:pathology / Q000502:physiology; D009929:Organ Size / Q000502:physiology; D015995:Prevalence; D012016:Reference Values; D055948:Sarcopenia / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D055815:Young Adult