Associations among sleep quality, sleep duration, and Alzheimer's disease biomarkers: A systematic review and meta‐analysis

Abstract INTRODUCTION Although sleep disturbances are widely recognized as risk factors for cognitive decline and Alzheimer's disease (AD), their influence on AD biomarkers remains unclear. This study aimed to clarify whether sleep quality or sleep duration affect amyloid beta (Aβ) and tau levels in plasma, cerebrospinal fluid (CSF), and positron emission tomography (PET) in non‐demented populations. METHODS PubMed, Web of Science, and Embase were systematically searched up to February 2025. RESULTS In total, 30 studies were included comprising 14,997 subjects. Individuals with poor sleep quality exhibited greater PET Aβ burden and higher Aβ42 levels in plasma than those with good sleep quality. Shorter sleep duration was associated with higher Aβ burden on PET. However, no association between either sleep quality or sleep duration and tau levels was found. DISCUSSION Sleep may be a modifiable marker of early AD management by modulating Aβ levels. Highlights lPoor sleep quality and shorter sleep duration were significantly associated with higher amyloid beta (Aβ) burden detected by positron emission tomography (PET) in non‐demented populations. Poor sleep quality was also associated with elevated Aβ42 levels in plasma. lNo significant associations were found between sleep quality or sleep duration and tau levels in plasma, cerebrospinal fluid, or PET. lInterventions targeting sleep could serve as a viable and low‐cost prevention strategy for early management of Alzheimer's disease.