title: Temporal Relationship Between Cognitive and Physical Performance in Middle-Aged to Oldest Old People.
abstract: BACKGROUND
  Cognitive and physical impairment frequently co-occur in older people. The aim of this study was to assess the temporal order of these age-related changes in cognitive and physical performance and to assess whether a relationship was different across specific cognitive and physical domains and age groups.
  
  
  METHODS
  Cognitive domains included global, executive, and memory function; physical domains included gait speed and handgrip strength. These domains were assessed in two population-based longitudinal cohorts covering the age ranges of 55-64, 65-74, 75-85, and 85-90 years with a follow-up of 5-12 years. Cross-lagged panel models were applied to assess the temporal relationships between the different cognitive and physical domains adjusting for age, sex, education, comorbidity, depressive symptoms, and physical activity.
  
  
  RESULTS
  Over all age groups, poorer executive function was associated with a steeper decline in gait speed (p < .05). From the age of 85 years, this relationship was found across all cognitive and physical domains (p < .02). From the age of 65 years, slower gait speed and/or weaker handgrip strength were associated with steeper declines in global cognitive function (p < .02), with statistically significant results across all cognitive domains in the age group of 75-85 years (p < .04).
  
  
  CONCLUSIONS
  The temporal relationship between cognitive and physical performance differs across domains and age, suggesting a specific rather than a general relationship. This emphasizes the importance of repeated measurements on different domains and encourages future research to the development of domain- and age-specific interventions.
authors.affiliation: Department of Gerontology and Geriatrics, Leiden University Medical Center, The Netherlands.|Deparment of Biomechanical Engineering, Delft University of Technology, The Netherlands.
authors.forename: Marjon
authors.initials: M
authors.lastname: Stijntjes
authors.affiliation: Department of Ageing Research and Housing Studies, Norwegian Social Research (NOVA), Oslo, Norway.
authors.forename: Marja J
authors.initials: MJ
authors.lastname: Aartsen
authors.affiliation: Department of Geriatric Medicine, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Diana G
authors.initials: DG
authors.lastname: Taekema
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, The Netherlands.
authors.forename: Jacobijn
authors.initials: J
authors.lastname: Gussekloo
authors.affiliation: Department of Sociology, VU University, Amsterdam, The Netherlands.|Department of Epidemiology and Biostatistics, EMGO+ Institute for Health and Care Research and.
authors.forename: Martijn
authors.initials: M
authors.lastname: Huisman
authors.affiliation: Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam, The Netherlands.|MOVE Research Institute Amsterdam, Department of Human Movement Sciences, VU University, The Netherlands.
authors.forename: Carel G M
authors.initials: CGM
authors.lastname: Meskers
authors.affiliation: Department of Gerontology and Geriatrics, Leiden University Medical Center, The Netherlands.
authors.forename: Anton J M
authors.initials: AJM
authors.lastname: de Craen
authors.affiliation: MOVE Research Institute Amsterdam, Department of Human Movement Sciences, VU University, The Netherlands.|Department of Medicine and Aged Care, Royal Melbourne Hospital, University of Melbourne, Victoria, Australia.
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Maier
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003071:Cognition; D005260:Female; D015577:Geriatric Assessment; D018737:Hand Strength; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D000072797:Walking Speed
keywords: Dynamic relationship; Executive function; Gait speed; Handgrip strength; Memory function