title: Accelerometer-assessed light physical activity is protective of future cognitive ability: A longitudinal study among community dwelling older adults.
abstract: Physical activity (PA), especially moderate-to-vigorous intensity, could protect older adults from cognitive impairment. However, most literature is based on self-reported PA which is limited by recall bias. Light PA is popular among older adults, but a paucity of objective longitudinal data has considered the relationship between light PA and cognitive ability. We examined if a higher level of objectively measured light PA, independent of moderate-to-vigorous physical activity (MVPA), was prospectively associated with better cognitive ability in older adults.
  
  
  
  A longitudinal study over 22.12 (±1.46) months including 274 community-dwelling older adults across 14 regions in Taiwan was undertaken. Cognitive ability was obtained using a Chinese version of the Ascertain Dementia 8-item Questionnaire (AD8) and light PA and MVPA captured by 7days accelerometer positioned on waist. Multivariable negative binomial regression adjusted for confounders were undertaken.
  
  
  
  274 participants (74.52years, 45.6% male) attended the follow-up (96.1%). Higher light PA, independent from MVPA, was associated with a reduced rate of decline in cognitive ability (rate ratio 0.75 [0.60-0.92]). MVPA, was also associated with a reduced decline in cognitive ability (rate ratio 0.85 [0.75-0.95]). Light PA was protective of cognitive ability in sensitivity analyses removing participants with activities of daily living difficulties, depressive symptoms and cognitive impairment at baseline.
  
  
  
  Our data suggest that light PA may offer a protective influence of future cognitive ability in community dwelling older adults. The promotion of light PA may be a valuable means to maintain cognitive ability in older age.
authors.affiliation: Physiotherapy Department, South London and Maudsley NHS Foundation Trust, Denmark Hill, London SE5 8AZ, UK; Health Service and Population Research Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London, Box SE5 8AF, UK; Faculty of Health, Social Care and Education, Anglia Ruskin University, Chelmsford, UK. Electronic address: brendon.stubbs@kcl.ac.uk.
authors.forename: Brendon
authors.initials: B
authors.lastname: Stubbs
authors.affiliation: Department of Exercise Health Science, National Taiwan University of Sport, Taiwan. Electronic address: ljchen@ntupes.edu.tw.
authors.forename: Li-Jung
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Department of Physical Education, National Tsing Hua University, Hsinchu, Taiwan. Electronic address: cjy@mail.nhcue.edu.tw.
authors.forename: Chun-Yi
authors.initials: CY
authors.lastname: Chang
authors.affiliation: Family Medicine Department, Taipei City Hospital Zhongxing Branch, Taiwan. Electronic address: das48@tpech.gov.tw.
authors.forename: Wen-Jung
authors.initials: WJ
authors.lastname: Sun
authors.affiliation: Graduate Institute of Sports and Health, National Changhua University of Education, Taiwan. Electronic address: powen@cc.ncue.edu.tw.
authors.forename: Po-Wen
authors.initials: PW
authors.lastname: Ku
mesh_terms: D061725:Accelerometry; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003071:Cognition; D060825:Cognitive Dysfunction / Q000517:prevention & control; D003863:Depression / Q000453:epidemiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006304:Health Status; D006801:Humans; D057187:Independent Living; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D013624:Taiwan / Q000453:epidemiology
keywords: Cognition; Cognitive decline; Dementia; Light physical activity; Moderate to vigorous physical activity; Old age; Older adults