title: Skeletal muscle function deficit: a new terminology to embrace the evolving concepts of sarcopenia and age-related muscle dysfunction.
abstract: BACKGROUND
  Concerns remain as to the best terminology to embrace sarcopenia's evolving conceptualization. Many of these concerns stem from the fact that age-related decrements in muscle performance associated with physical impairment are only partially explained by decreases in muscle mass and that other pathophysiologic factors contribute to age-related impairments in muscle performance.
  
  
  METHODS
  Review of literature on the evolving conceptualization of sarcopenia since its early definition in 1989 and concerns with terminology.
  
  
  RESULTS
  Early definitions of sarcopenia were based solely on muscle mass in relationship to the range of muscle within a reference population. Subsequent definitions added performance criteria to muscle mass alone. The Foundation for the National Institutes of Health Sarcopenia Project identified criteria for clinically relevant low muscle strength (weakness) and low lean mass. Progress on the sarcopenia's evolving definitions has not been accompanied by recommendations on specific terminologies that address the lack of sufficient specificity from the use of an anatomic term to define a functional condition with numerous now known nonanatomic contributory factors. Skeletal Muscle Function Deficit is a broader construct that accommodates a set of diagnoses that includes both sarcopenia and other age-related muscle dysfunctions.
  
  
  CONCLUSIONS
  Skeletal Muscle Function Deficit is proposed as a new terminology to embrace the evolving conceptualization of sarcopenia and other age-related muscle dysfunctions. It comprises a variety of contributory etiologies and has the potential to provide a framework for developing diagnostic categories that are useful for both clinical practice and research.
authors.affiliation: U.S. Department of Health and Human Services, Division of Geriatrics and Clinical Gerontology, National Institute on Aging, National Institutes of Health, 7201 Wisconsin Avenue, Bethesda, MD 20892-9205. Rosaly.correa-de-araujo@nih.gov.
authors.forename: Rosaly
authors.initials: R
authors.lastname: Correa-de-Araujo
authors.forename: Evan
authors.initials: E
authors.lastname: Hadley
mesh_terms: D000367:Age Factors; D006801:Humans; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D055948:Sarcopenia / Q000175:diagnosis* / Q000503:physiopathology*; D009626:Terminology as Topic; D014481:United States
keywords: Deficit.; Muscle function; Muscle strength; Muscle weakness; Sarcopenia; Skeletal muscle; Skeletal muscle function deficit
references.citation: J Am Geriatr Soc. 2002 May;50(5):889-96
references.pmid: 12028177
references.citation: Front Physiol. 2012 Jul 11;3:260
references.pmid: 22934016
references.citation: Clin Nutr. 2010 Apr;29(2):154-9
references.pmid: 20060626
references.citation: Am J Epidemiol. 1998 Apr 15;147(8):755-63
references.pmid: 9554417
references.citation: J Appl Physiol (1985). 2012 Aug 15;113(4):677-9
references.pmid: 22518833
references.citation: Age Ageing. 2010 Jul;39(4):412-23
references.pmid: 20392703
references.citation: J Am Med Dir Assoc. 2013 Feb;14(2):80-2
references.pmid: 23131548
references.citation: Curr Opin Rheumatol. 2012 Nov;24(6):623-7
references.pmid: 22955023
references.citation: J Gerontol A Biol Sci Med Sci. 2014 May;69(5):576-83
references.pmid: 24737560
references.citation: J Gerontol A Biol Sci Med Sci. 2012 Jan;67(1):28-40
references.pmid: 21444359
references.citation: J Am Med Dir Assoc. 2011 May;12(4):249-56
references.pmid: 21527165
references.citation: Osteoporos Int. 2010 Apr;21(4):543-59
references.pmid: 19779761
references.citation: J Am Med Dir Assoc. 2011 Jul;12(6):403-9
references.pmid: 21640657
references.citation: J Gerontol A Biol Sci Med Sci. 2014 May;69(5):547-58
references.pmid: 24737557