0759 BIDIRECTIONAL ASSOCIATIONS BETWEEN WHITE MATTER INTEGRITY AND SLEEP QUALITY IN THE ELDERLY. THE ROTTERDAM STUDY

Abstract

White matter microstructure may underlie the structural and functional brain differences observed in people with sleep complaints. Insomnia patients were shown to have lower white matter integrity measured by diffusion tensor imaging (DTI), compared to healthy controls. However, previous findings are based on cross-sectional data of small, clinical samples and cannot be generalized to the general population. In the Rotterdam Study, 2808 participants (mean age 59.3 ± 7.7, 54.4% women) underwent repeated brain MRI imaging, and filled in the Pittsburg Sleep Quality Questionnaire at baseline and follow-up. Average follow up was 5.6 years. Using diffusion tensor imaging, we studied the strength and direction of the longitudinal associations between white matter microstructure (global and tract specific) and sleep quality in elderly people from the general population. Higher global mean diffusivity (MD) at baseline predicted a decrease in sleep quality, which was driven by a lower fractional anisotropy (FA) (β=-0.05, p-value=0.009) and higher MD (0.05, p-value=0.009) in the uncinate fasciculus and several other association tracts. Sleep complaints at baseline were not associated with global diffusion metrics, but predicted an increase in MD in the parahippocampal part of the cingulum (β=0.07, p-value=0.004) across the follow up. Low white matter integrity across the brain predicts a decrease of sleep quality in the elderly. Vice versa, bad sleep quality at baseline is related to a decrease in white matter integrity, but this effect seems to be specific for limbic tracts around the hippocampus. This tract has previously been implicated in aging and cognitive decline. This study provides evidence for bidirectional associations between sleep quality and white matter microstructure in the aging brain. ERAWEB scholarship grant financed by the European Commission was granted to DK (grant agreement 2013–2548/001-001-EMA-2). Financial support was recived by Erasmus Medical Center, The Netherlands Organization for Health Research and Development, the Dutch Technology Foundation STW, which is part of the Netherlands Organisation for scientific research (NWO) and partly funded by the Dutch Ministry of Economic Affairs.