title: Respiratory muscle strength predicts decline in mobility in older persons.
abstract: OBJECTIVE
  To test the hypothesis that respiratory muscle strength is associated with the rate of change in mobility even after controlling for leg strength and physical activity.
  
  
  METHODS
  Prospective study of 890 ambulatory older persons without dementia who underwent annual clinical evaluations to examine change in the rate of mobility over time.
  
  
  RESULTS
  In a linear mixed-effect model adjusted for age, sex, and education, mobility declined about 0.12 unit/year, and higher levels of respiratory muscle strength were associated with a slower rate of mobility decline (estimate 0.043, SE 0.012, p < 0.001). Respiratory muscle strength remained associated with the rate of change in mobility even after controlling for lower extremity strength (estimate 0.036, SE 0.012, p = 0.004). In a model that included terms for respiratory muscle strength, lower extremity strength and physical activity together, all three were independent predictors of mobility decline in older persons. These associations remained significant even after controlling for body composition, global cognition, the development of dementia, parkinsonian signs, possible pulmonary disease, smoking, joint pain and chronic diseases.
  
  
  CONCLUSIONS
  Respiratory muscle strength is associated with mobility decline in older persons independent of lower extremity strength and physical activity. Clinical interventions to improve respiratory muscle strength may decrease the burden of mobility impairment in the elderly.
authors.affiliation: Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA. Aron_S_Buchman@rush.edu
authors.forename: A S
authors.initials: AS
authors.lastname: Buchman
authors.forename: P A
authors.initials: PA
authors.lastname: Boyle
authors.forename: R S
authors.initials: RS
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Leurgans
authors.forename: R C
authors.initials: RC
authors.lastname: Shah
authors.forename: D A
authors.initials: DA
authors.lastname: Bennett
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D002641:Chicago; D006801:Humans; D007866:Leg / Q000502:physiology; D008137:Longitudinal Studies; D008568:Memory / Q000502:physiology*; D051346:Mobility Limitation; D009043:Motor Activity / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D010809:Physical Fitness; D011237:Predictive Value of Tests; D012132:Respiratory Muscles / Q000502:physiology*; D014505:Urban Population
references.citation: J Gerontol A Biol Sci Med Sci. 2000 Apr;55(4):M221-31
references.pmid: 10811152
references.citation: Eur Respir J. 2005 Jan;25(1):125-30
references.pmid: 15640333
references.citation: J Am Geriatr Soc. 2000 Dec;48(12):1618-25
references.pmid: 11129752
references.citation: Biometrics. 1982 Dec;38(4):963-74
references.pmid: 7168798
references.citation: J Am Geriatr Soc. 2007 Oct;55(10):1618-23
references.pmid: 17697103
references.citation: Chest. 2003 Feb;123(2):387-98
references.pmid: 12576356
references.citation: Neurology. 1984 Jul;34(7):939-44
references.pmid: 6610841
references.citation: Psychol Aging. 2002 Jun;17(2):179-93
references.pmid: 12061405
references.citation: Respirology. 2002 Sep;7(3):233-9
references.pmid: 12153689
references.citation: Am J Respir Crit Care Med. 1996 Mar;153(3):976-80
references.pmid: 8630582
references.citation: J Gerontol A Biol Sci Med Sci. 2001 Jul;56(7):M412-23
references.pmid: 11445600
references.citation: J Cardiopulm Rehabil. 2004 May-Jun;24(3):137-45
references.pmid: 15235292
references.citation: J Psychiatr Res. 1975 Nov;12(3):189-98
references.pmid: 1202204
references.citation: J Int Neuropsychol Soc. 2005 Jul;11(4):400-7
references.pmid: 16209420
references.citation: Arch Phys Med Rehabil. 1999 Feb;80(2):130-5
references.pmid: 10025485
references.citation: Respir Med. 1998 Feb;92(2):221-7
references.pmid: 9616516
references.citation: CMAJ. 2006 Mar 14;174(6):801-9
references.pmid: 16534088
references.citation: J Rehabil Res Dev. 2005 Mar-Apr;42(2):211-24
references.pmid: 15944886
references.citation: Obesity (Silver Spring). 2006 Mar;14(3):345-56
references.pmid: 16648603
references.citation: Neurology. 2005 Dec 27;65(12):1901-6
references.pmid: 16380610
references.citation: Muscle Nerve. 1997 Jun;20(6):679-90
references.pmid: 9149074
references.citation: J Gerontol A Biol Sci Med Sci. 1995 Nov;50(6):M317-23
references.pmid: 7583803
references.citation: J Am Geriatr Soc. 2007 Jan;55(1):11-9
references.pmid: 17233680
references.citation: J Am Geriatr Soc. 1999 Oct;47(10):1257-60
references.pmid: 10522962
references.citation: J Am Geriatr Soc. 2005 Oct;53(10):1675-80
references.pmid: 16181165
references.citation: Thorax. 2005 May;60(5):401-9
references.pmid: 15860716
references.citation: Am J Respir Crit Care Med. 1994 Feb;149(2 Pt 1):430-8
references.pmid: 8306041
references.citation: J Am Geriatr Soc. 2006 Feb;54(2):255-61
references.pmid: 16460376
references.citation: Muscle Nerve. 2002 Jan;25(1):17-25
references.pmid: 11754180
references.citation: Arch Phys Med Rehabil. 2002 Jun;83(6):811-5
references.pmid: 12048660
references.citation: Neurology. 2002 Jul 23;59(2):198-205
references.pmid: 12136057
references.citation: Neuroepidemiology. 2005;25(4):163-75
references.pmid: 16103727
references.citation: Am J Prev Med. 1989 Mar-Apr;5(2):65-72
references.pmid: 2730794
references.citation: JAMA. 1990 Jun 13;263(22):3029-34
references.pmid: 2342214
references.citation: J Gerontol A Biol Sci Med Sci. 2005 Mar;60(3):350-4
references.pmid: 15860473