Increased sedentary behavior is associated with neurodegeneration and worse cognition in older adults over a 7‐year period despite high levels of physical activity
Marissa A. Gogniat, Omair A. Khan, Judy Li, Chorong Park, W Hudson Robb, Panpan Zhang, Yunyi Sun, Elizabeth E. Moore, Michelle L Houston, Kimberly R. Pechman, Niranjana Shashikumar, L. Taylor Davis, Dandan Liu, Bennett A. Landman, Keith R. Cole, Corey J. Bolton, Katherine A. Gifford, Timothy J. Hohman, Kelsie M Full, Angela L. Jefferson
Abstract
INTRODUCTION: Sedentary behavior may be a modifiable risk factor for Alzheimer's disease (AD). We examined how sedentary behavior relates to longitudinal brain structure and cognitive changes in older adults. METHODS: Vanderbilt Memory and Aging Project participants (n = 404) completed actigraphy (7 days), neuropsychological assessment, and 3T brain MRI over a 7-year period. Cross-sectional and longitudinal linear regressions examined sedentary time in relation to brain structure and cognition. Models were repeated testing for effect modification by apolipoprotein E (APOE) ε4 status. RESULTS: In cross-sectional models, greater sedentary time related to a smaller AD-neuroimaging signature (β = -0.0001, p = 0.01) and worse episodic memory (β = -0.001, p = 0.003). Associations differed by APOE-ε4 status. In longitudinal models, greater sedentary time related to faster hippocampal volume reductions (β = -0.1, p = 0.008) and declines in naming (β = -0.001, p = 0.03) and processing speed (β = -0.003, p = 0.02; β = 0.01, p = 0.01). DISCUSSION: Results support the importance of reducing sedentary time, particularly among aging adults at genetic risk for AD. HIGHLIGHTS: Greater sedentary behavior is related to neurodegeneration and worse cognition. Associations differed by APOE-ε4 carrier status in cross-sectional models. Sedentary behavior is an independent risk factor for Alzheimer's disease.