Oximetry parameters in sleep apnea may be key prognostic indicators of central auditory dysfunction

Obstructive sleep apnea is one of the most common respiratory disorders characterized by intermittent obstruction of the upper airways during sleep, leading to apnea and hypopnea, and respiratory event-related arousal (R.E.R.A.). It has been linked with auditory dysfunction both in the cochlear and higher auditory pathways. However, available literature has yielded conflicting results.

Against the above background, Chee Chean Lim, University of Malaya, Kuala Lumpur, Malaysia, and colleagues aimed to investigate the impact of O.S.A. severity and their polysomnography parameters on hearing function.

After evaluation for sleep disorders, the researchers included a total of 44 patients who were categorized into four groups according to the apnea-hypopnea index (AHI). They made a comparison of distortion product otoacoustic emission (D.P.O.A.E.), pure tone audiometry (P.T.A.), and auditory brainstem response (A.B.R.) corresponding with AHI severity. Polysomnography oximetry parameters of oxygen desaturation index, per cent SPO2 < 90%, mean SPO2, and minimum SPO2 were correlated with their respective A.B.R., P.T.A., and D.P.O.A.E. results.

Polysomnography oximetry parameters of oxygen desaturation index, mean SPO2, minimum SPO2 and per cent SPO2 < 90% were correlated with their respective P.T.A., D.P.O.A.E. and A.B.R. results.

The authors reported the following findings:

• There was no significant change in the P.T.A., D.P.O.A.E. and A.B.R. results in connection with AHI severity.
• Significant correlations were found between mean SPO2 and per cent SPO2 < 90% with A.B.R. wave I, III and V absolute latencies.
• Minimum SPO2 was also significantly correlated with wave III peak latency changes.

"Our findings further expound the conflicting associations of auditory dysfunction in patients with obstructive sleep apnea," the researchers wrote in their study. "Oximetry parameters, namely, per cent SPO2 < 90%, mean SPO2, and minimum SPO2 could be critical prognostic indicators of central auditory dysfunction as revealed in the study."

"These parameters should be further explored to gauge the degree of the severity of O.S.A. rather than AHI utilization alone," they wrote. "The hypoxic burden derived could be a better predictor of auditory function abnormalities rather than one derived from AHI."

Reference:

Lim, C.C., Ahmad, T.E.B.T.N., Sawali, H.B. et al. Evaluation of auditory system in obstructive sleep apnea patients. Eur Arch Otorhinolaryngol (2022). https://doi.org/10.1007/s00405-022-07711-1