Interactive associations between sleep properties and regional brain structure by race in midlife women
Alexandra Paget‐Blanc, Rebecca C Thurston, Rachel A Schroeder, Howard J Aizenstein, Carol A. Derby, Minje Wu, Yuefang Chang, Pauline M Maki- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Geriatrics and Gerontology
- Neurology (clinical)
- Developmental Neuroscience
- Health Policy
- Epidemiology
Abstract
Background
Poor sleep is a modifiable factor associated with increased risk of Alzheimer’s disease (AD). In cognitively normal adults, poor sleep is associated with AD‐like patterns of brain atrophy. Females experience greater age‐related deterioration in sleep quality than males, particularly around midlife, and these changes are more pronounced in racial/ethnic minority women than White women. Nevertheless, the association of sleep quality with brain health in midlife women, and race differences in this association is poorly understood. Here we examined the interactive associations of sleep and race on regional brain volume.
Method
Participants were cognitively normal women from the MsBrain cohort (n = 182; 59.16±4.23 years old; 99.0% postmenopausal; 88.5% White). Brain imaging was performed at the MR Research Center of the University of Pittsburgh on a 3T Siemens Tim Trio MR scanner. Freesurfer was used to segment and evaluate cortical thickness. Participants completed 72‐hour wrist actigraphy monitoring, which generated four sleep parameters: total sleep time (TST), wake after sleep onset (WASO), sleep fragmentation (SF) and sleep efficiency. The associations between sleep regional brain volume, and modification of these associations by race were evaluated using multiple linear regression adjusted for age, education, and presence of APOE 4 allele.
Result
TST was inversely associated with cortical volume in the bilateral inferior parietal lobules (L: p<0.001; R: p<.01), superior parietal lobules (L: p<0.01; R: p<.05), precuneus (L:p<0.01; R: <.05), the left caudal anterior cingulate cortex (p<.05), and right parahippocampal cortex (p<.05). There was a significant interaction of SF and WASO and race on brain volume such that among Black women but not White women, higher SF and WASO were each associated with lower volume in bilateral orbitofrontal cortex (p<.05) and left cuneus (p<.01).
Conclusion
In midlife women, longer sleep time and poorer sleep continuity may influence brain structure even in the absence of dementia. Results suggest that differences in the impact of sleep on brain health be explored further to understand race disparities in AD.. Understanding factors contributing to sleep degradation at midlife, particularly in Black women, may be a critical step to address gender and race disparities in AD.