Is obstructive sleep apnea syndrome a risk factor for auditory pathway?

The transduction mechanism of the inner ear and the transmission of nerve impulses along the auditory way are highly dependent upon the cochlear oxygen supply. Several studies have considered the possibility that obstructive sleep apnea-hypopneas during sleep can interfere with these processes, and the results are not uniform. The aim of the study is to evaluate the auditory function in adult patients affected by severe obstructive sleep apnea syndrome (OSAS). Thirty-nine patients in this study were included and divided in OSAS group, with severe OSAS (Apnea-Hypopnea Index, AHI > 30), and control group with snoring without OSAS (AHI < 5). Each patient was subjected to pure-tone audiogram (PTA), otoacoustic emission (OAE), and brainstem auditory evoked potentials. The OSAS group showed a PTA significantly higher than the control group (14.23 +/- 6.25 vs. 7.45 +/- 2.54; p < 0.01), a lower TEOAE reproducibility (0.57 +/- 0.10 vs. 0.92 +/- 0.10; p < 0.01) such as a lower signal-to-noise 0atio (p < 0,01) and a lower DPOAE amplitude (5.96 +/- 6.34; 13.18 +/- 2.97; p < 0.01). The mean latencies of waves I, III, and V were prolonged in OSAS group as compared to the healthy people, especially for wave V (p < 0.05). The interpeak latency (IPL) of I-V was significantly higher (p < 0.01) in the OSAS patients (5.84 +/- 0.15) as compared to the control group (5.4 +/- 0.12), such as IPLs I-III and III-V (p < 0.05). Our data showed an auditory dysfunction in patients affected by severe OSAS, suggesting that severe OSAS could represent a risk factor for auditory pathway.