Disrupted Rest-Activity Rhythms and Cerebral Small Vessel Disease Pathology in Older Adults.

BACKGROUND AND PURPOSE: The pathogenesis of cerebral small vessel disease remains incompletely understood. The relationship between circadian rhythm disturbances and histopathologic measures of cerebral small vessel disease has not been studied. We hypothesized that disrupted circadian rest-activity rhythms would be associated with a higher burden of cerebral small vessel disease pathology. METHODS: We studied 561 community-dwelling older adults (mean age at death, 91.2, 27.4% male) from the Rush Memory and Aging Project. We used actigraphy to quantify several measures of 24-hour rest-activity rhythmicity, including interdaily stability, intradaily variability, and amplitude, and used ordinal logistic regression models to relate these measures to the severity of cerebral arteriolosclerosis, atherosclerosis, macroinfarcts, and microinfarcts, assessed at autopsy. RESULTS: Lower interdaily stability was associated with a higher burden of arteriolosclerosis, higher intradaily variability was associated with a higher burden of atherosclerosis and subcortical infarcts, and lower amplitude was associated with a higher burden of arteriosclerosis, atherosclerosis and subcortical macroinfarcts. Moreover, the associations between interdaily stability and arteriolosclerosis and intradaily variability and subcortical infarcts were independent of cardiovascular risk factors, sleep fragmentation, and medical comorbidities. CONCLUSIONS: Disrupted rest-activity rhythms are associated with a greater burden of cerebral small vessel disease in older adults.