Association between serum α-synuclein levels and neurocognitive deficits in patients with obstructive sleep apnea: A case-control study.

BACKGROUND

Obstructive sleep apnea (OSA) is increasingly recognized as a contributor to neurocognitive dysfunction, yet the underlying biological mechanisms remain insufficiently understood. α-Synuclein, a presynaptic protein implicated in neurodegenerative processes, may be involved in OSA-related cognitive impairment, but its peripheral expression and diagnostic utility have not been fully elucidated.

METHODS

In this case-control study, 108 untreated OSA patients and 100 age- and sex-matched healthy controls underwent overnight polysomnography and neurocognitive assessments, including the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Serum α-synuclein levels were measured using ELISA. Logistic and linear regression analyses were conducted to assess associations between α-synuclein levels and cognitive performance, while ROC curve analysis evaluated the biomarker's predictive accuracy.

RESULTS

Serum α-synuclein levels were significantly elevated in OSA patients compared to controls (385.62 ± 125.47 pg/mL vs. 215.30 ± 78.65 pg/mL, p < 0.001). Elevated α-synuclein levels were independently associated with cognitive impairment in OSA (adjusted OR = 1.832, 95 % CI: 1.624-1.995, p = 0.013). Linear regression showed a significant inverse relationship between α-synuclein and MMSE scores (β = -0.459, p = 0.005). ROC analysis revealed strong predictive value for cognitive deficits (AUC = 0.892, sensitivity = 84.0 %, specificity = 86.0 %).

CONCLUSION

Elevated serum α-synuclein levels are independently associated with neurocognitive impairment in OSA and may serve as a potential biomarker for early detection and risk stratification. Future longitudinal and interventional studies are warranted to validate its clinical utility.