title: Longitudinal associations between physical and cognitive performance among community-dwelling older adults.
abstract: To assess the directionality of the association between physical and cognitive decline in later life, we compared patterns of decline in performance across groups defined by baseline presence of cognitive and/or physical impairment [none (n = 217); physical only (n = 169); cognitive only (n = 158), or both (n = 220)] in a large sample of participants in a cognitive aging study at the Knight Alzheimer's Disease Research Center at Washington University in St. Louis who were followed for up to 8 years (3,079 observations). Rates of decline reached 20% for physical performance and varied across cognitive tests (global, memory, speed, executive function, and visuospatial skills). We found that physical decline was better predicted by baseline cognitive impairment (slope = -1.22, p<0.001), with baseline physical impairment not contributing to further decline in physical performance (slope = -0.25, p = 0.294). In turn, baseline physical impairment was only marginally associated with rate of cognitive decline across various cognitive domains. The cognitive-functional association is likely to operate in the direction of cognitive impairment to physical decline although physical impairment may also play a role in cognitive decline/dementia. Interventions to prevent further functional decline and development of disability and complete dependence may benefit if targeted to individuals with cognitive impairment who are at increased risk.
authors: Alzheimer's Disease Research Center, Departments of Neurology, Psychiatry, and Population Health, New York University School of Medicine, New York, NY, United States of America.
authors: Magdalena I
authors: MI
authors: Tolea
authors: Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO, United States of America.
authors: John C
authors: JC
authors: Morris
authors: Alzheimer's Disease Research Center, Departments of Neurology, Psychiatry, and Population Health, New York University School of Medicine, New York, NY, United States of America.
authors: James E
authors: JE
authors: Galvin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000502:physiology; D000544:Alzheimer Disease / Q000453:epidemiology / Q000503:physiopathology*; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000453:epidemiology / Q000503:physiopathology*; D003704:Dementia / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D010808:Physical Examination