title: Gait speed and cognitive decline over 2 years in the Ibadan study of aging.
abstract: BACKGROUND
  The evidence suggesting that gait speed may represent a sensitive marker for cognitive decline in the elderly requires support from diverse racial groups.
  
  
  OBJECTIVE
  We investigated the relationship between gait speed and cognitive decline over 2 years in a community dwelling sample of elderly Africans.
  
  
  METHODS
  Data are from the Ibadan study of aging (ISA) conducted among a household multi-stage probability sample of 2149 Yoruba Nigerians aged 65 years or older. Gait speed was measured as the time taken to complete a 3 or 4m distance at normal walking speed. We assessed cognitive functions with a modified version of the 10-word learning list and delay recall test, and examined the relationship between baseline gait speed, as well as gait speed changes, and follow-up cognition using multiple linear regression and longitudinal analyses using random effects.
  
  
  RESULTS
  Approximately 71% of 1461 participants who were dementia free and who had their gait speed measured at baseline (2007) were successfully followed up in two waves (2008 and 2009). Along with increasing age, poor health and economic status, a slower baseline gait speed was independently associated with poorer follow-up cognition in both linear regression (1.2 words, 95% CI=0.48-2.0) and longitudinal analyses (0.8 words, 95% CI=0.44-1.2). Also, a greater change in gait speed between 2007 and 2009 was associated with the worst follow-up cognition (0.3 words, 95% CI=0.09-0.51).
  
  
  CONCLUSIONS
  The finding that a substantial change in gait speed was associated with reduced cognitive performance is of potential importance to efforts aimed at early identification of cognitive disorders in this population.
authors.affiliation: WHO Collaborating Centre for Research and Training in Mental Health, Neuroscience and Substance Abuse, Department of Psychiatry, College of Medicine, University of Ibadan, P.M.B. 5017 (GPO), Ibadan, Nigeria.
authors.forename: Akin
authors.initials: A
authors.lastname: Ojagbemi
authors.affiliation: National Centre for Epidemiology and Population Health, Research School of Population Health, ANU College of Medicine, Biology and Environment, The Australian National University, Building 62 Mills Road, Canberra ACT 0200, Australia.
authors.forename: Catherine
authors.initials: C
authors.lastname: D'Este
authors.affiliation: Department of Health Statistics and Informatics at the World Health Organization (WHO), 20 Avenue Appia, Geneva 1207 CH-1211, Switzerland.
authors.forename: Emese
authors.initials: E
authors.lastname: Verdes
authors.affiliation: Department of Health Statistics and Informatics at the World Health Organization (WHO), 20 Avenue Appia, Geneva 1207 CH-1211, Switzerland.
authors.forename: Somnath
authors.initials: S
authors.lastname: Chatterji
authors.affiliation: WHO Collaborating Centre for Research and Training in Mental Health, Neuroscience and Substance Abuse, Department of Psychiatry, College of Medicine, University of Ibadan, P.M.B. 5017 (GPO), Ibadan, Nigeria. Electronic address: ogureje@comui.edu.ng.
authors.forename: Oye
authors.initials: O
authors.lastname: Gureje
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D005684:Gait / Q000502:physiology*; D020233:Gait Disorders, Neurologic / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009549:Nigeria / Q000453:epidemiology; D012189:Retrospective Studies
keywords: Cognition; Dementia; Developing countries; Gait speed