Associations of distinct sedentary behaviors with cortical, subcortical, and white matter hyperintensity volumes: Evidence from the ARIC study

INTRODUCTION: Longitudinal studies linking sedentary behavior (SB) in different contexts to brain structure and white matter hyperintensity (WMH) volume remain limited. METHODS: We analyzed data from the Atherosclerosis Risk in Communities (ARIC) study (n = 1,712). Self-reported SB was assessed at visit 1 (1987-1989), with neuroimaging (3T magnetic resonance imaging [MRI]) at visit 5 (2011-2013). Participants were non-demented adults (57% women; 53[5.2] years) who reported frequency of TV watching and occupational sitting. Outcomes included cortical, subcortical, and Alzheimer's disease-signature regions (ADSR), and total WMH brain volumes. RESULTS: Frequent TV watching was associated with increased WMH volume and reduced frontal, occipital, and ADSR volumes. Sitting during work, which is more cognitively active, was linked to lower WMH and larger frontal (males only), occipital, and parietal volumes. Results remained consistent when adjusted for physical activity. DISCUSSION: SB is associated with structural brain and WMH volumes. Cognitively active SB may preserve brain structure and cerebrovascular health.