title: Interaction of obstructive sleep apnoea and cognitive impairment with slow gait speed in middle-aged and older adults.
abstract: to investigate whether slow gait speed is associated with cognitive impairment and further whether the association is modified by obstructive sleep apnoea (OSA).
  
  
  
  in total, 2,222 adults aged 49-80 years, free from dementia, stroke and head injury were asked to walk a 4-m course at fast and usual gait speeds. The time taken to walk was measured. All participants completed the Korean Mini-Mental State Examination, which was validated in the Korean language, to assess cognitive function. Additionally, the participants completed a polysomnography test to ascertain OSA (defined as an apnoea-hypopnoea index ≥15). Multivariable linear regression models were utilised to test the associations.
  
  
  
  time taken to walk 4 m showed significant inverse associations with cognitive scores (P value = 0.001 at fast gait speed and P = 0.002 at usual gait speed). Furthermore, a significant interaction according to OSA on the association between time to walk and cognitive impairment was found (P value for interaction = 0.003 at fast gait speed and P value for interaction = 0.007 at usual gait speed).
  
  
  
  we found that the inverse association between the time taken to walk 4 m and a cognitive score became significantly stronger, if an individual had OSA.
authors.affiliation: Institute of Human Genomic Study, School of Medicine, Korea University Ansan Hospital, Ansan, The Republic of Korea.
authors.forename: Sunghee
authors.initials: S
authors.lastname: Lee
authors.affiliation: Institute of Human Genomic Study, School of Medicine, Korea University Ansan Hospital,  Ansan, The Republic of Korea.|Division of Pulmonary, Department of Internal Medicine, Korea University Ansan Hospital,  Ansan, The Republic of Korea.
authors.forename: Chol
authors.initials: C
authors.lastname: Shin
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology* / Q000523:psychology; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait; D006801:Humans; D016014:Linear Models; D008297:Male; D000073216:Mental Status and Dementia Tests; D008875:Middle Aged; D015999:Multivariate Analysis; D017286:Polysomnography; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D000070857:Walk Test; D016138:Walking
keywords: cognition; gait; obstructive sleep apnoea; older people