Sleep Medicine · Jun 6, 2026

Overnight sleep features and next-morning brain metabolism in older adults

By Carvalho DZ, Adolf J, Kremen V et al.

BACKGROUND: The relationship between sleep and brain metabolism remains poorly understood. This study aimed to determine whether overnight sleep features, estimated using a home sleep apnea system based on peripheral arterial tonometry, are associated with regional FDG-PET uptake in older adults. METHODS: We analyzed cognitively unimpaired participants (≥60 years) from the Mayo Clinic Study of Aging. Each participant underwent overnight objective sleep assessment with Watch PAT, followed by FDG-PET imaging the next morning. PET data were co-registered to 3T MRI and segmented into 47 regions of interest (ROIs) after estimating voxel number-weighted median FDG uptake across hemispheres. Associations between sleep macrostructure and sleep apnea/hypoxemia burden with regional FDG levels were examined using partial Spearman's rank correlations adjusted for age or grey matter volume (GMV). RESULTS: Thirty-seven participants were studied (70.3% female, median age was 72 [IQR 68-78]). We found widespread negative associations between wake after sleep onset (WASO) and FDG level in cortical areas, primarily involving ventromedial/ventrolateral prefrontal cortex, lateral temporal and occipital cortices (ρ = -0.47 to -0.34, P < 0.05). Total sleep time was associated with FDG uptake in medial structures (ρ = 0.39 to 0.42, P < 0.05), including posterior cingulate, retrosplenial cortex, hippocampus, parahippocampus, thalamus and caudate. Hypoxic burden was associated with medial occipital FDG level (ρ = 0.35 to 0.39, P < 0.05). Regional GMV did not mediate these associations. WASO was associated with higher insomnia severity index and less restful sleep. DISCUSSION: Sleep macrostructure and hypoxic burden exhibited significant associations with brain metabolism, potentially contributing to brain health, cognitive function, and daytime symptoms.

doi.org/10.1016/j.sleep.2026.109072PubMed 42284964Populations