Objective: The goal was to study auditory function in prediabetes. Pure Tone Audiometry (PTA), Distortion Product Otoacoustic Emission (DPOAE) and Auditory Brainstem Response (ABR) were used to detect whether there is early hearing deterioration in the prediabetes.
Methods: 168 participants underwent the Oral Glucose Tolerance Test (OGTT). 58 prediabetes patients younger than 60 years old, and 50 controls, age and sex matched, were enrolled. All subjects underwent PTA, DPOAE and ABR examinations. All relevant parameters including air and bone conduction pure tone audiometry, DPOAE amplitude and ABR latencies were collected.
Results: (1) There were 25 cases with hearing loss in prediabetes (43%), while 6 cases in the control group (12%) by PTA; the difference was statistically significant (P <0.001). The hearing thresholds at each frequency (0.25kHz, 0.5kHz, 1kHz, 2kHz, 4kHz and 8kHz) in the prediabetes were higher than those in controls but only statistically significant at 4kHz and 8kHz (P < 0. 001). Air- and bone-conduction pure-tone thresholds synchronization increased. The difference between air conduction and bone conduction checked by PTA was less than 10dB. (2) DPOAE amplitude at each frequency in the prediabetes group was lower than control group; there were statistically significant differences at 1, 1.5, 2, 3, 4, 6 kHz (P < 0. 001). (3) There were no significant differences of neuron response latencies in ABR measurements between prediabetes and the control group.
Conclusions: (1) Loss of auditory function began in the prediabetes stage. Sub-clinical presentations were more pronounced in the prediabetes stage. (2) Bilateral symmetry sensorineural hearing loss, especially at high frequencies, is very characteristic in prediabetic patients. (3)The preliminary findings are that DPOAE is needed to detect the usually slight hearing loss in prediabetes whereas PTA was less sensitive and did not detect such losses. (4) The damage is mainly cochlear, not in the central nervous system.
Y. Meng: None. X. Zhuang: None. B. Lu: None. X. Wu: None.
Capital Health Research and Development of Special Fund (2016-2-7022, 2019-1-1091); Science and Technology Plan of Beijing Municipal Education Commission (KM201610025020)