Nocturnal Hypoxemia Burden Correlates With Vestibular Dysfunction in Obstructive Sleep Apnea

Area of Science:

• Neurology
• Otolaryngology
• Sleep Medicine

Background:

• Obstructive sleep apnea (OSA) is increasingly recognized as a potential factor in vestibular dysfunction.
• However, the specific parameters of OSA that correlate with vestibular function remain unclear.

Purpose of the Study:

• To quantitatively assess the correlation between hypoxemia severity indices in OSA patients and caloric slow-phase eye velocity (SPV), a key indicator of vestibular function.

Main Methods:

• A retrospective analysis of 82 adults who underwent polysomnography (PSG) and bithermal caloric testing.
• Evaluated predictors included hypoxemia burden (AHI, ODI, CT90, nadir SpO2), sleep fragmentation, sleep architecture, and ancillary measures.
• Statistical analyses involved Pearson's correlations, adjusted linear regression, and random forest modeling with TreeSHAP values for feature importance.

Main Results:

• SPV showed significant inverse correlations with AHI, ODI, and cumulative time with SpO2 < 90% (CT90).
• In adjusted models, AHI remained a significant predictor of reduced SPV.
• Hypoxemia metrics (ODI, AHI, CT90) and BMI were the most important predictors in the random forest model, though overall model variance explained was low (R²=0.065).

Conclusions:

• Nocturnal hypoxemia burden is the primary predictor of reduced caloric SPV in OSA patients.
• The findings suggest prioritizing desaturation assessment in clinical evaluations of OSA patients.
• Further research is needed to confirm if mitigating hypoxemia improves vestibular outcomes.