How is self-reported sleep-disordered breathing linked with biomarkers of Alzheimer's disease?

Sleep-disordered breathing (SDB) is prevalent in Alzheimer's disease (AD). Here, we assessed how self-reported SDB is linked with AD biomarkers, including amyloid-beta plaque burden (Aβ), regional fluorodeoxyglucose uptake (rFDG-PET), grey matter volume (GMV), cognitive scores, and cerebrospinal fluid (CSF) biomarkers. We selected 757 individuals, including AD, mild cognitive impairment (MCI), and cognitively unimpaired (CU) groups, and divided them according to self-reported SDB condition. Using a stratified subsampling approach, we selected 512 matched subsamples, and effect sizes (ES) of the group-SDB interaction were computed for each biomarker and cognitive score across subsamples. Linear regression assessed associations between the ES of Aβ, rFDG, and GMV with the ES of cognitive scores and CSF biomarkers. The group-SDB interaction had a medium-sized effect on Aβ, rFDG, and GMV biomarkers in several brain areas. Participants with SDB exhibited reduced Aβ burden and increased rFDG uptake in the CU and MCI groups, whereas the AD group showed elevated Aβ burden and decreased rFDG. Additionally, SDB+ individuals demonstrated GMV alterations across all groups. The ES of group-SDB interaction on Aβ in the precuneus, middle temporal gyrus, and fusiform gyrus was associated with the ES of cognitive scores. Taken together, we observed a robust association of SDB with Aβ pathology in PET and CSF relative to rFDG and GMV in the AD group, which was also associated with cognitive decline.