ASSOCIATION OF CIRCADIAN REST AND ACTIVITY RHYTHMS WITH BRAIN VOLUMES IN COGNITIVELY NORMAL OLDER ADULTS

• Published in: Innovation in aging 2017-07, Vol.1 (suppl_1), p.866-866
• Main Authors: Spira, A.P., Zipunnikov, V., Wu, M.N., Dey, D., Simonsick, E.M., Ferrucci, L., Davatzikos, C., Resnick, S.
• Format: Article
• Language: English
• Subjects: Abstracts
• ISSN: 2399-5300; 2399-5300
• DOI: 10.1093/geroni/igx004.3115

Disturbed circadian rest/activity rhythms have been linked to cognitive decline, but little is known about their association with neuroimaging-derived brain volumes. We studied 176 cognitively normal participants in the Baltimore Longitudinal Study of Aging aged 74.8 ± 8.9 years (58% women, 29% non-White), who were instructed to wear wrist actigraphs for seven consecutive 24-hour periods and underwent 3T magnetic resonance imaging scans, with total gray and white matter, ventricular volume, and hippocampal volume quantified using a multi-atlas segmentation approach (MUSE software). We used function-on-scalar regression models, a data-driven approach, to quantify links between timing of actigraphic activity counts and brain volumes, adjusting for age, sex, education, CES-D score, MMSE score, and intracranial volume. Gray matter, white matter, ventricular, and hippocampal volumes were considered in separate models and time intervals rounded to the nearest 30 minutes. On average, lower gray matter volume was associated with higher activity levels between 2:30 AM and 12:30 PM and between 4:30 PM and 11:30 PM, lower white matter volume was associated with greater activity between 12:00 AM and 11:00 AM, and larger ventricles were associated with lower activity between 3:00 AM and 6:00 AM and higher activity between 6:30 PM and 12:00 AM (all p