Abstract
INTRODUCTION
We examined obstructive sleep apnea (OSA) severity's association with Alzheimer's disease (AD) plasma biomarkers, independent or synergistic with cerebrospinal fluid (CSF) amyloid, and as a proof of concept, whether plasma amyloid beta (Aβ)42/Aβ40 with OSA severity improves detection of amyloidosis and tau pathology.
METHODS
In 120 cognitively normal older adults (70 with CSF data) from New York University sleep and aging studies (2013–2021), OSA severity was measured using apnea/hypopnea index with 4% desaturation; plasma Aβ40, Aβ42, tau, and neurofilament light chain (NfL) via single molecule array; CSF amyloid and tau via enzyme-linked immunosorbent assay. Associations evaluated adjusted correlations and generalized models; receiver operating characteristic analyses evaluated diagnostic accuracy.
RESULTS
OSA severity correlated with plasma Aβ40 (r = 0.21), Aβ42 (r = 0.26), and Aβ42/Aβ40 (r = 0.20). Plasma tau and NfL associations depended on CSF–Aβ42. OSA severity with Aβ42/Aβ40 improved CSF amyloidosis (area under the curve [AUC] = 0.78) and tau pathology (AUC = 0.71) detection.
DISCUSSION
OSA severity relates to elevated plasma Aβ and, with CSF amyloid, to tau/NfL. Combined plasma and OSA measures aid non-invasive AD associations’ detection.
Highlights
Obstructive sleep apnea (OSA) is associated with plasma amyloid beta (Aβ)40, Aβ42, and Aβ42/Aβ40.
OSA in synergism with brain amyloid levels is associated with plasma tau and neurofilament light chain.
Combined with plasma Aβ42/Aβ40, OSA enhances brain amyloidosis and tau pathology detection.