Functional Decline and Body Composition Change in Older Adults With Alzheimer Disease: A Retrospective Cohort Study at a Japanese Memory Clinic.

ABSTRACT

BACKGROUND: There is a dearth of longitudinal data on body composition, function, and physical performance in persons with Alzheimer's disease (AD). OBJECTIVES: The aim was to describe the trajectories of function, body composition, and physical performance in older adults with AD. METHODS: In this retrospective cohort study, data were collected from older adults (n=1402) diagnosed with AD (mean age 78.1 y old, women 69.3%). Cognitive function was assessed using the mini-mental state examination. Proxy-reported instrumental and basic activities of daily living were assessed using the Lawton and Barthel indexes. Body composition was assessed using bioelectrical impedance analysis. Physical performance was assessed using the timed up and go test and grip strength. RESULTS: Median (interquartile range) of follow-up time was 2.2 (1.2 to 3.6) years. Participants' mini-mental state examination score, Barthel index, and Lawton index declined over time. Skeletal muscle mass index and physical performance (timed up and go test and grip strength) decreased, while fat mass index increased with time. No significant changes or slight decline in weight and body mass index was observed. CONCLUSIONS: Muscle mass and physical performance are likely to decline in older adults with AD. Clinicians should assess muscle mass and physical performance trajectories regularly in these patients and intervene appropriately.