title: Association between muscle mass, leg strength, and fat mass with physical function in older adults: influence of age and sex.
abstract: OBJECTIVE
  The purposes of this study were to determine the relationship between muscle mass, muscle strength, muscle quality, and fat mass with a composite measure of physical function in older adults, and to determine whether these relations differed by age and sex.
  
  
  METHODS
  Participants consisted of 1280 adults aged ≥ 55 yr from the NHANES study. Reduced rank regression was used to identify patterns of muscle mass, muscle strength, muscle quality, and fat mass related to physical function.
  
  
  RESULTS
  A single relevant pattern emerged that included leg strength and fat mass as predictors of the 7 physical function variables. The leg strength loading was significantly greater than the fat mass loading in men and women aged 55-64 and ≥ 75, and differed between sexes.
  
  
  CONCLUSIONS
  Leg strength and fat mass best predict physical function in older adults and the relative importance varies according to age and sex.
authors.affiliation: School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada. danielle.bouchard@usherbrooke.ca
authors.forename: Danielle R
authors.initials: DR
authors.lastname: Bouchard
authors.forename: Mariane
authors.initials: M
authors.lastname: Héroux
authors.forename: Ian
authors.initials: I
authors.lastname: Janssen
mesh_terms: D015502:Absorptiometry, Photon; D000367:Age Factors; D000368:Aged; D000375:Aging; D001823:Body Composition; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006304:Health Status; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009749:Nutrition Surveys; D012044:Regression Analysis; D057566:Self Report; D012737:Sex Factors