The “oldest old” are more likely to have dementia if they have physical impairments.
Poor physical performance and impaired cognition have been associated with each other in both cross-sectional and prospective analyses. This study adds support for the connection, focusing on a specific population aged 90 and older. The 629 participants (mean age, 94; 73% women; 74% with more than a high school education) in the main analysis were part of a cohort-based study of aging. Between 2003 and 2009, participants underwent assessment of physical performance, including objective measures of walking speed, ability to arise from the seated position, balance, and grip strength.
Dementia was diagnosed in 162 participants (25.8%) according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria using neurological evaluation, a cognitive screening test (Mini-Mental State Exam), and functional rating scales (Clinical Dementia Rating Scale and Functional Activities Questionnaire). Poor performance on each of the physical tasks was independently associated with an approximate doubling in the odds of all-cause dementia diagnosis. Secondary analyses that included 218 additional cohort members with partial physical performance datasets did not significantly affect the results.
Comment: Although these results are unique because of the age demographic of the participants, as the authors point out, the generalizability of the results may be challenged by the homogeneity of the study population of highly educated, Caucasian women aged 90 and older. Moreover, as with all cross-sectional studies, one cannot determine causation from these findings.
Source: Journal Watch Neurology