title: Associations between physical performance and executive function in older adults with mild cognitive impairment: gait speed and the timed "up & go" test.
abstract: BACKGROUND
  Older adults with amnestic mild cognitive impairment (aMCI) are at higher risk for developing Alzheimer disease. Physical performance decline on gait and mobility tasks in conjunction with executive dysfunction has implications for accelerated functional decline, disability, and institutionalization in sedentary older adults with aMCI.
  
  
  OBJECTIVE
  The purpose of this study was to examine whether performance on 2 tests commonly used by physical therapists (usual gait speed and Timed "Up & Go" Test [TUG]) are associated with performance on 2 neuropsychological tests of executive function (Trail Making Test, part B [TMT-B], and Stroop-Interference, calculated from the Stroop Word Color Test) in sedentary older adults with aMCI.
  
  
  METHODS
  The study was a cross-sectional analysis of 201 sedentary older adults with memory impairment participating in a longitudinal intervention study of cognitive function, aging, exercise, and health promotion.
  
  
  METHODS
  Physical performance speed on gait and mobility tasks was measured via usual gait speed and the TUG (at fast pace). Executive function was measured with the TMT-B and Stroop-Interference measures.
  
  
  RESULTS
  Applying multiple linear regression, usual gait speed was associated with executive function on both the TMT-B (β=-0.215, P=.003) and Stroop-Interference (β=-0.195, P=.01) measures, indicating that slower usual gait speed was associated with lower executive function performance. Timed "Up & Go" Test scores (in logarithmic transformation) also were associated with executive function on both the TMT-B (β=0.256, P<.001) and Stroop-Interference (β=0.228, P=.002) measures, indicating that a longer time on the TUG was associated with lower executive function performance. All associations remained statistically significant after adjusting for age, sex, depressive symptoms, medical comorbidity, and body mass index.
  
  
  CONCLUSIONS
  The cross-sectional nature of this study does not allow for inferences of causation.
  
  
  CONCLUSIONS
  Physical performance speed was associated with executive function after adjusting for age, sex, and age-related factors in sedentary older adults with aMCI. Further research is needed to determine mechanisms and early intervention strategies to slow functional decline.
authors: Department of Rehabilitation Medicine, University of Washington, 1959 NE Pacific St, Box 356490, Seattle, WA 98195, USA. emcg@uw.edu
authors: Ellen L
authors: EL
authors: McGough
authors: Valerie E
authors: VE
authors: Kelly
authors: Rebecca G
authors: RG
authors: Logsdon
authors: Susan M
authors: SM
authors: McCurry
authors: Barbara B
authors: BB
authors: Cochrane
authors: Joyce M
authors: JM
authors: Engel
authors: Linda
authors: L
authors: Teri
references: J Gerontol A Biol Sci Med Sci. 2000 Apr;55(4):M221-31
references: 10811152
references: Arch Phys Med Rehabil. 2010 Apr;91(4):584-8
references: 20382291
references: Phys Ther. 2002 Feb;82(2):128-37
references: 11856064
references: Arch Neurol. 1999 Mar;56(3):303-8
references: 10190820
references: Am J Geriatr Psychiatry. 2008 May;16(5):416-24
references: 18448852
references: Int Psychogeriatr. 2008 Feb;20(1):32-9
references: 18072982
references: Phys Ther. 2008 Dec;88(12):1482-91
references: 18820094
references: Dement Geriatr Cogn Disord. 2006;22(4):306-11
references: 16931884
references: CNS Spectr. 2008 Jan;13(1):45-53
references: 18204414
references: Phys Ther. 2000 Sep;80(9):896-903
references: 10960937
references: Clin Neuropsychol. 2008 Sep;22(5):842-50
references: 17934999
references: Arch Neurol. 2007 Jun;64(6):862-71
references: 17562935
references: Mov Disord. 2008 Feb 15;23(3):329-42; quiz 472
references: 18058946
references: J Psychiatr Res. 1975 Nov;12(3):189-98
references: 1202204
references: Lancet. 2006 Apr 15;367(9518):1262-70
references: 16631882
references: Arch Clin Neuropsychol. 2009 Feb;24(1):81-8
references: 19395358
references: Int J Geriatr Psychiatry. 2011 Apr;26(4):364-72
references: 20845402
references: Int J Geriatr Psychiatry. 2007 Dec;22(12):1217-22
references: 17562522
references: Int J Geriatr Psychiatry. 2008 May;23(5):523-30
references: 18058828
references: Acta Neuropathol. 1991;82(4):239-59
references: 1759558
references: J Gerontol A Biol Sci Med Sci. 2009 Jan;64(1):110-7
references: 19182230
references: J Intern Med. 2004 Sep;256(3):183-94
references: 15324362
references: J Clin Exp Neuropsychol. 2000 Aug;22(4):518-28
references: 10923061
references: J Am Geriatr Soc. 2008 Jul;56(7):1244-51
references: 18482293
references: J Am Geriatr Soc. 1991 Feb;39(2):142-8
references: 1991946
references: J Gerontol A Biol Sci Med Sci. 2008 Dec;63(12):1350-5
references: 19126848
references: Age Ageing. 2006 May;35(3):240-5
references: 16513677
references: Nat Protoc. 2006;1(5):2277-81
references: 17406468
references: Neurosci Biobehav Rev. 2007;31(4):485-97
references: 17306372
references: Age Ageing. 1997 Jan;26(1):15-9
references: 9143432
references: BMC Geriatr. 2009 Sep 01;9:41
references: 19723315
references: Br J Psychiatry. 1982 Jun;140:566-72
references: 7104545
references: Assessment. 2006 Mar;13(1):62-79
references: 16443719
references: J Clin Psychol. 1985 Sep;41(5):643-50
references: 4044847
references: Neuron. 2004 Sep 30;44(1):195-208
references: 15450170
references: J Neurol Sci. 2005 Mar 15;229-230:89-93
references: 15760625
references: J Gerontol A Biol Sci Med Sci. 2007 Oct;62(10):1134-41
references: 17921427
references: J Am Geriatr Soc. 2003 Nov;51(11):1633-7
references: 14687395
references: Int Psychogeriatr. 2008 Feb;20(1):18-31
references: 18031593
references: Acta Neuropathol. 2006 Oct;112(4):389-404
references: 16906426
references: Percept Mot Skills. 1985 Dec;61(3 Pt 2):1283-9
references: 4094872
references: Clin Neuropsychol. 2005 Sep-Dec;19(3-4):329-77
references: 16120535
references: Gerontology. 2006;52(6):359-65
references: 16905887
references: J Psychiatr Res. 1982-1983;17(1):37-49
references: 7183759
references: Clin Neuropsychol. 2005 Sep-Dec;19(3-4):378-463
references: 16120536
references: Nebr Symp Motiv. 1994;41:23-55
references: 7739748
references: J Am Geriatr Soc. 2005 Mar;53(3):374-80
references: 15743277
references: J Neuropsychiatry Clin Neurosci. 2002 Fall;14(4):377-405
references: 12426407
references: J Gerontol B Psychol Sci Soc Sci. 1997 Jan;52B(1):P28-39
references: 9008673
references: Neuropsychologia. 2006;44(11):2017-36
references: 16527316
references: Arch Neurol. 2006 May;63(5):665-72
references: 16682536
references: J Clin Psychol. 1976 Jul;32(3):654-8
references: 956433
references: Arch Neurol. 2006 Dec;63(12):1763-9
references: 17172617
references: J Psychosom Res. 2002 Aug;53(2):647-54
references: 12169339
references: Dement Geriatr Cogn Disord. 2007;24(2):125-37
references: 17622760
references: Arthritis Rheum. 2003 Apr 15;49(2):156-63
references: 12687505
references: J Neurol Neurosurg Psychiatry. 2009 Jun;80(6):608-13
references: 19204027
references: J Gerontol A Biol Sci Med Sci. 2008 Dec;63(12):1329-34
references: 19126845
references: Brain Cogn. 1992 Sep;20(1):8-23
references: 1389124
references: Arch Neurol. 2002 Apr;59(4):601-6
references: 11939895
references: Med Sci Sports Exerc. 2007 Aug;39(8):1435-45
references: 17762378