ANALYSIS OF REST-ACTIVITY RHYTHMS AND RISK OF INCIDENT MILD COGNITIVE IMPAIRMENT AND DEMENTIA IN OLDER WOMEN

In older adults, desynchronized circadian rhythms have been associated with medical illness, including Alzheimer Disease. Activity, which can be easily measured using actigraphy over consecutive 24-hour periods, is a valid marker of entrained sleep phase and correlates with entrained endogenous circadian phase. We compare results of both parametric and non-parametric analyses to test the association of rest-activity patterns with incident MCI and dementia in 2132 older women who had 2 or more 24-hrs periods of actigraphy data collected at baseline. Follow-up neuropsychological testing approximately 5 years later is used to classify women as normal, MCI, or dementia. Logistic regression models are adjusted for age, clinic site, race, education, body mass index, functional status, comorbidities, medication use, and health habits. Results suggest the importance of overall amplitude and rhythmicity, as well as timing of activity patterns over the 24-hour day as risk factors for incident MCI/dementia.