title: Epidemiology of sarcopenia.
abstract: OBJECTIVE
  To examine patterns of muscle mass change with aging and to estimate the prevalence of sarcopenia.
  
  
  METHODS
  Cross-sectional survey.
  
  
  METHODS
  Population-based study in Rochester, Minnesota.
  
  
  METHODS
  Age-stratified sample of men and women from the community.
  
  
  METHODS
  Muscle mass estimated from total body scans by dual-energy X-ray absorptiometry. Sarcopenia was defined as muscle mass more than 2 standard deviations below the sex-specific young-normal mean.
  
  
  RESULTS
  Total lean body mass (exclusive of bone) and total skeletal muscle mass both were greater in men than women and declined linearly with age as judged from these cross-sectional data. Adjustment for height reduced the gender difference. The age- and sex-adjusted prevalence of sarcopenia varied from 6 to 15% among subjects 65 years of age or over, depending on the muscle mass parameter that was evaluated, but prevalence rates were quite sensitive to the normal values used to define cutoff levels. Subjects with sarcopenia appeared to have more physical limitations than the others.
  
  
  CONCLUSIONS
  Late in life, a substantial portion of the population reaches low levels of muscle mass that are associated with increased physical disability. However, additional efforts are needed to validate an operational definition of sarcopenia.
authors.affiliation: Department of Health Sciences Research, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
authors.forename: L J
authors.initials: LJ
authors.lastname: Melton
authors.forename: S
authors.initials: S
authors.lastname: Khosla
authors.forename: C S
authors.initials: CS
authors.lastname: Crowson
authors.forename: M K
authors.initials: MK
authors.lastname: O'Connor
authors.forename: W M
authors.initials: WM
authors.lastname: O'Fallon
authors.forename: B L
authors.initials: BL
authors.lastname: Riggs
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001823:Body Composition; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D009133:Muscular Atrophy / Q000453:epidemiology*; D016017:Odds Ratio; D017698:Postmenopause / Q000502:physiology; D015995:Prevalence; D012016:Reference Values; D012044:Regression Analysis