Is β- amyloid a reliable marker for assessing neurocognitive functions in middle-aged OSAS patients??

Area of Science:

• Neurology
• Sleep Medicine
• Biochemistry

Background:

• Obstructive sleep apnea syndrome (OSAS) causes sleep fragmentation and hypoxemia, contributing to cognitive deficits.
• Amyloid beta (Aβ) is a key biomarker in Alzheimer's disease, prompting interest in its role in early neurocognitive dysfunction.
• Understanding the link between OSAS, cognitive function, and Aβ may aid in early detection and management strategies.

Purpose of the Study:

• To investigate the association between plasma Aβ levels and neurocognitive performance in middle-aged OSAS patients.
• To explore the relationship between polysomnographic parameters and cognitive function in OSAS.
• To determine if Aβ levels correlate with OSAS severity and cognitive impairment.

Main Methods:

• A prospective, cross-sectional study included 126 middle-aged OSAS patients without prior neurocognitive conditions.
• Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) and Epworth Sleepiness Scale (ESS).
• Plasma total Aβ levels were measured, alongside polysomnographic parameters like apnea-hypopnea index (AHI) and oxygen saturation.

Main Results:

• Reduced sleep duration, lower nocturnal oxygen saturation, and increased time below 90% SpO2 (T90%) correlated with lower MoCA scores.
• Serum Aβ levels were elevated in severe OSAS, negatively correlated with MoCA scores and slow-wave sleep.
• Higher Aβ levels showed a positive correlation with AHI and oxygen desaturation index (ODI), and an inverse correlation with minimum oxygen saturation.

Conclusions:

• Neurocognitive impairment is prevalent in patients with OSAS.
• Elevated serum Aβ levels are directly associated with OSAS severity.
• OSA-related hypoxemia is linked to diminished cognitive function in these patients.