title: Criteria for clinically relevant weakness and low lean mass and their longitudinal association with incident mobility impairment and mortality: the foundation for the National Institutes of Health (FNIH) sarcopenia project.
abstract: BACKGROUND
  This analysis sought to determine the associations of the Foundation for the National Institutes of Health Sarcopenia Project criteria for weakness and low lean mass with likelihood for mobility impairment (gait speed ≤ 0.8 m/s) and mortality. Providing validity for these criteria is essential for research and clinical evaluation.
  
  
  METHODS
  Among 4,411 men and 1,869 women pooled from 6 cohort studies, 3-year likelihood for incident mobility impairment and mortality over 10 years were determined for individuals with weakness, low lean mass, and for those having both. Weakness was defined as low grip strength (<26kg men and <16kg women) and low grip strength-to-body mass index (BMI; kg/m(2)) ratio (<1.00 men and <0.56 women). Low lean mass (dual-energy x-ray absorptiometry) was categorized as low appendicular lean mass (ALM; <19.75kg men and <15.02kg women) and low ALM-to-BMI ratio (<0.789 men and <0.512 women).
  
  
  RESULTS
  Low grip strength (men: odds ratio [OR] = 2.31, 95% confidence interval [CI] = 1.34-3.99; women: OR = 1.99, 95% CI 1.23-3.21), low grip strength-to-BMI ratio (men: OR = 3.28, 95% CI 1.92-5.59; women: OR = 2.54, 95% CI 1.10-5.83) and low ALM-to-BMI ratio (men: OR = 1.58, 95% CI 1.12-2.25; women: OR = 1.81, 95% CI 1.14-2.87), but not low ALM, were associated with increased likelihood for incident mobility impairment. Weakness increased likelihood of mobility impairment regardless of low lean mass. Mortality risk patterns were inconsistent.
  
  
  CONCLUSIONS
  These findings support our cut-points for low grip strength and low ALM-to-BMI ratio as candidate criteria for clinically relevant weakness and low lean mass. Further validation in other populations and for alternate relevant outcomes is needed.
authors.affiliation: DSc, Hebrew SeniorLife Institute for Aging Research, 1200 Centre Street, Boston, MA 02131. rmclean@hsl.harvard.edu.
authors.forename: Robert R
authors.initials: RR
authors.lastname: McLean
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Shardell
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Alley
authors.forename: Peggy M
authors.initials: PM
authors.lastname: Cawthon
authors.forename: Maren S
authors.initials: MS
authors.lastname: Fragala
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
authors.forename: Anne M
authors.initials: AM
authors.lastname: Kenny
authors.forename: Katherine W
authors.initials: KW
authors.lastname: Peters
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Kiel
authors.forename: Maria T
authors.initials: MT
authors.lastname: Vassileva
authors.forename: Qian-Li
authors.initials: QL
authors.lastname: Xue
authors.forename: Subashan
authors.initials: S
authors.lastname: Perera
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Studenski
authors.forename: Thuy-Tien L
authors.initials: TT
authors.lastname: Dam
mesh_terms: D000368:Aged; D005260:Female; D005684:Gait / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D051346:Mobility Limitation; D018908:Muscle Weakness / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology*; D009316:National Institutes of Health (U.S.); D055948:Sarcopenia / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology*; D013851:Thinness / Q000150:complications* / Q000503:physiopathology*; D014481:United States / Q000453:epidemiology
keywords: Impairment.; Mobility; Muscle; Sarcopenia
references.citation: J Am Geriatr Soc. 2003 Nov;51(11):1602-9
references.pmid: 14687390
references.citation: Contemp Clin Trials. 2005 Oct;26(5):557-68
references.pmid: 16085466
references.citation: J Gerontol A Biol Sci Med Sci. 2014 May;69(5):567-75
references.pmid: 24737559
references.citation: J Gerontol A Biol Sci Med Sci. 2014 May;69(5):559-66
references.pmid: 24737558
references.citation: J Appl Physiol (1985). 2001 Jun;90(6):2157-65
references.pmid: 11356778
references.citation: Am J Epidemiol. 1998 Apr 15;147(8):755-63
references.pmid: 9554417
references.citation: Age Ageing. 2013 Mar;42(2):203-9
references.pmid: 23321202
references.citation: Muscle Nerve. 2002 Jan;25(1):17-25
references.pmid: 11754180
references.citation: Age Ageing. 2010 Jul;39(4):412-23
references.pmid: 20392703
references.citation: J Am Geriatr Soc. 2010 Feb;58(2):219-26
references.pmid: 20370856
references.citation: N Engl J Med. 1995 Mar 23;332(12):767-73
references.pmid: 7862179
references.citation: Contemp Clin Trials. 2005 Oct;26(5):569-85
references.pmid: 16084776
references.citation: J Hand Surg Br. 1993 Feb;18(1):129-32
references.pmid: 8436850
references.citation: BMJ. 2010 Feb 05;340:c221
references.pmid: 20139215
references.citation: J Am Geriatr Soc. 2000 Jun;48(6):625-30
references.pmid: 10855597
references.citation: J Gerontol A Biol Sci Med Sci. 2000 Apr;55(4):M221-31
references.pmid: 10811152
references.citation: Am J Epidemiol. 1979 Sep;110(3):281-90
references.pmid: 474565
references.citation: J Am Med Dir Assoc. 2011 May;12(4):249-56
references.pmid: 21527165
references.citation: J Appl Physiol (1985). 2003 Nov;95(5):1851-60
references.pmid: 14555665
references.citation: J Am Geriatr Soc. 2000 Dec;48(12):1618-25
references.pmid: 11129752
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
references.citation: J Gerontol A Biol Sci Med Sci. 2004 Mar;59(3):255-63
references.pmid: 15031310
references.citation: J Am Geriatr Soc. 2008 Sep;56(9):1665-73
references.pmid: 18759758
references.citation: Clin Nutr. 2010 Apr;29(2):154-9
references.pmid: 20060626
references.citation: J Gerontol A Biol Sci Med Sci. 2005 Mar;60(3):324-33
references.pmid: 15860469
references.citation: J Nutr Health Aging. 2000;4(3):162-4
references.pmid: 10936903
references.citation: JAMA. 2005 May 4;293(17):2102-8
references.pmid: 15870413
references.citation: J Am Geriatr Soc. 2002 May;50(5):897-904
references.pmid: 12028178
references.citation: J Nutr Health Aging. 2013 Mar;17(3):259-62
references.pmid: 23459979
references.citation: J Nutr. 1997 May;127(5 Suppl):990S-991S
references.pmid: 9164280
references.citation: J Gerontol A Biol Sci Med Sci. 2012 Jan;67(1):28-40
references.pmid: 21444359