Deep sleep slow wave–spindle coupling is selectively linked to plasma amyloid-β levels in older adults in clinical trials

= 70.5 (0.74)) with varying cognitive functioning. Blood samples post-baseline and post-intervention were analyzed for Aβ 1-42/1-40-ratio. Irrespective of cognitive functioning, slow wave-spindle coupling was the best predictor for baseline Aβ, better than slow wave activity, age or cognitive functioning. Specifically, better Aβ-levels were linked to a coupling physiology resembling a younger brain. While intervention-induced increases in slow wave activity were linked to a beneficial Aβ-response across all cognitive levels, increases in slow wave-spindle coupling benefited Aβ-response exclusively in cognitively impaired individuals. Our results suggest a link between SW-spindle coupling and Aβ going beyond slow wave activity. This hints towards a potential specific function of SW-spindle coupling related to the early pathophysiology of Alzheimer's disease.