Abstract Details

Title Hypoxia Affects Glymphatic Efficiency: Assessing Glymphatic Disruption in Obstructive Sleep Apnea Using Near-infrared Spectroscopy

Topic Sleep

Presentation(s) P3 - Poster Session 3 (5:00 PM-6:00 PM)

Poster/Presentation
Number 14-004

Objective This study aimed to determine if OSA impairs cerebral fluid dynamics, measured via the flux changes between NIRS-derived HbO and water concentrations, as a novel surrogate marker for blunted glymphatic clearance during sleep.

Background Near-Infrared Spectroscopy (NIRS) is a non-invasive imaging technique used to monitor cerebral oxygenation and hemodynamic changes. Obstructive Sleep Apnea (OSA) causes recurrent airway obstruction and disrupts oxygen homeostasis, leading to neurocognitive and cardiovascular dysfunction. We explored a novel surrogate measure of glymphatic clearance in OSA, focusing on sleep-related fluctuations in oxyhemoglobin (HbO) and water dynamics, using flux differences between water and HbO as proxies for flow changes.

Design/Methods NIRS measured changes in HbO and water concentrations during sleep in OSA participants (N=9) and healthy controls (N=18). Data were preprocessed to remove motion artifacts, bandpass filtered (0.005–0.2 Hz), and analyzed using the modified Beer-Lambert law to extract phase and amplitude. Statistical analyses assessed differences in concentration modulation between HbO and water.

Results

Healthy individuals exhibited distinct water concentration changes across sleep stages, which were significantly blunted in the OSA group. Post-hoc tests showed significant amplitude differences during N3 and Wake in healthy participants (P<0.0001, d=1.22), but no differences in the OSA group. While HbO concentration was modulated across sleep stages in controls, this modulation was also blunted in the OSA group. Notably, HbO concentration showed a remarkable decrease during REM sleep specifically in OSA positive participants.

Conclusions

Disrupted water concentration changes in OSA subjects indicate impaired glymphatic function, particularly during deep sleep, which is critical for waste clearance. The reduced HbO concentration during REM sleep in OSA subjects suggests severe nocturnal oxygen desaturation and implies potential systemic and neurological impacts.

Authors/Disclosures
Sujasha Gupta, PhD PRESENTER	Dr. Gupta has nothing to disclose.
J. Kent Werner, Jr., MD, PhD (Uniformed Services University)	Dr. Werner has received personal compensation for serving as an employee of Cogentis Therapeutics. Dr. Werner has stock in Cogentis Therapeutics. Dr. Werner has received intellectual property interests from a discovery or technology relating to health care. Dr. Werner has received intellectual property interests from a discovery or technology relating to health care. Dr. Werner has received personal compensation in the range of $100,000-$499,999 for serving as a Neurologist with United States Navy. Dr. Werner has received personal compensation in the range of $50,000-$99,999 for serving as a CEO / CoFounder with Cogentis Therapeutics.
William G. Coon, PhD	Dr. Coon has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Arena Labs.
Franck G. Amyot, PhD (HJF)	Dr. Amyot has nothing to disclose.
Angeliki Pollatou	Dr. Pollatou has received research support from The Geneva Foundation.
Angelica M. Lee, DO (Uniformed Services University of the Health Sciences)	Dr. Lee has nothing to disclose.
Elizabeth Metzger	Ms. Metzger has received personal compensation for serving as an employee of The Geneva Foundation. Ms. Metzger has received research support from University of Michigan .

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