Investigating the Link Between Objective Sleep Metrics and Cerebral Small Vessel Disease in a Population-Based Cohort

Cerebral small vessel disease (CSVD), a disorder that affects the cerebral microvasculature, is commonly associated with aging and may contribute to dementia and stroke. Increasing evidence suggests a link between CSVD and sleep disturbances, but the association remains poorly understood. This study, part of the population-based Hamburg City Health Study, integrated portable sleep diagnostics (WatchPAT-200) with brain imaging techniques sensitive to subtle microstructural (peak-width of skeletonized mean diffusivity (PSMD)) and cortical alterations. Linear and logistic regression models were performed, accounting for demographic, sleep-related covariates, and vascular risk factors, to elucidate the importance of sleep and the maintenance of cerebral vascular health in aging. In 154 participants (63.26 ± 8.19 years, 41.56% women), sleep compositions characterised by a higher proportion of light sleep relative to deep sleep were associated with higher log-transformed PSMD and lower cortical thickness. However, REM sleep relative to non-REM sleep was not associated with log-transformed PSMD or cortical thickness, and no associations were observed between sleep-stage compositions and log-transformed white matter hyperintensity (WMH) load or log-transformed perivascular space (PVS) volume. Additionally, longer TST was associated with relevant sleep apnea. High-resolution neuroimaging, combined with home sleep monitoring, suggests an association between sleep disturbances and greater CSVD-related changes in aging. PSMD serves as a sensitive biomarker for early microstructural changes before visible damage occurs, thus supporting early detection to preserve cerebrovascular health. Given our cross-sectional study design, the exact causality requires future longitudinal studies.