Associations of sleep behaviors with white matter hyperintensity volume in middle-aged to older adults

Introduction: Poor sleep has been associated with elevated dementia risk, potentially related to its cerebrovascular consequences, measured by cerebral white matter hyperintensity (WMH) volume. Methods: We examined self-reported sleep behaviors and prospective magnetic resonance imaging (MRI) WMH volume, measured 8.8 ± 1.7 (mean ± SD) years later, in 23,377 healthy UK Biobank participants. Each sleep behavior was adjusted for demographic, imaging, and clinical covariates (Model 1), as well as vascular health and lifestyle factors (Model 2), and significant sleep behaviors were then mutually adjusted. Results: In Model 1, all poor sleep behaviors were associated with greater WMH volume. In Model 2, only sleep duration outside 7-9 h (β = 0.015, false discovery rate [FDR]p = 0.014), increased daytime napping (β = 0.018, FDRp = 0.008), and greater sleeplessness (β = 0.015, FDRp = 0.014) were associated with greater WMH volume, with each behavior demonstrating distinct contributions (0.004 ≤ FDRp's ≤ 0.025). Discussion: Self-reported sleep behaviors were prospectively associated with greater WMH volume, suggesting a potential sleep-related pathway influencing vascular brain health and dementia risk.