IMPACT OF COGNITIVE FRAILTY ON DAILY ACTIVITIES IN OLDER PERSONS

Abstract

An International Consensus Group on “Cognitive Frailty” was organized by the International Academy on Nutrition and Aging and the International Association of Gerontology and Geriatrics in 2013 and provides the first definition of a “Cognitive Frailty” condition in older adults. The aim of the study was to examine the impact of physical and/or cognitive frailty on incidence of dementia in community living older adults. A total of 4072 older adults aged 65 years and older who were enrolled in the National Center for Geriatrics and Gerontology–Study of Geriatric Syndromes (NCGG–SGS). We characterized physical frailty as limitations in three or more of the following five domains: slow walking speed, muscle weakness, exhaustion, low activity and weight loss. To screen for cognitive frailty, we used the National Center for Geriatrics and Gerontology-Functional Assessment Tool (NCGG–FAT) which included tests of word list memory, attention and executive function (tablet version of the Trail Making Test, part A and B), and processing speed (tablet version of the Digit Symbol Substitution Test). Two or more cognitive impairments indicated by an age-adjusted score of at least 1.5 standard deviations below the reference threshold was characterized as cognitive frailty. Incidence of dementia was determined using database of the Japanese Health Insurance System during 24 months. The overall prevalence of physical frailty, cognitive impairment, and cognitive frailty, i.e. co-occurrence of frailty and cognitive impairment, was 5.1%, 5.5%, and 1.1%, respectively. During the follow-up period, 81 participants (2.0%) developed dementia. We found significant relationships between incidence of dementia and cognitive impairment (Hazard Ratio (HR) 3.85, 95% confidence interval (95% CI) 2.09 to 7.10) and cognitive frailty (HR 6.19, 95% CI 2.73 to 13.99). There was no significant relationships between incidence of dementia and physical frailty (HR 1.95, 95% CI 0.97 to 3.91). The individuals with cognitive frailty had the highest risks of incidence of dementia. Future investigation is necessary to identify prevention strategy of dementia for the older adults with cognitive frailty.