Endocrine Abstracts

Objective: Altered hearing function in diabetic patients has been found in both pure tone audiometry and otoacoustic emissions (OAEs). We intended to evaluate the cochlear function with both DPOAE and TEOAE in patients with DM without polyneuropathy and hypertension.

Patients and methods: Study group consisted of type 2 diabetic patients and healthy control group consisted of healthy age and sex matched volunteers. Detailed ear examination, pure tone audiometry, TEOAE, and DPOAE were assessed in all volunteers. Electromyography for excluding polyneuropathy was done in patients with DM. Ophthalmoscopic fundus examination was performed to all diabetic patients.

Results: There are not statistically significant difference between groups according to sex, gender and smoking habits (P>0.05). Right ear TEOAE 20 kHz frequency SNR (P=0.043), 40 kHz frequency SNR (P=0.018) and left ear TEOAE 20 kHz frequency SNR (P=0.004) are lower in patients with DM. Although, there are differences in respective kHz values between DM and healthy control according to TEOAE test report, there is not statistical significant difference between groups according to overall TEOAE frequencies (left ear (P=0.837), right ear (P=0.442). There is a statistically significant negative correlation between right ear TEOAE 20 kHz SNR (P=0.044) and serum glucose level. Also there is a negative correlation but statistically non significant between right ear TEOAE 40 kHz SNR and retinopathy (P=0.053). No correlations were found among duration of diabetes, HbA1c values, TEOAEs and DPOAEs.

Conclusion: This is the first study in electromyography test negative, nonalcoholic and normotensive type 2 DM patients for evaluating cochlear function with both TEOAE and DPOAE. Albeit TEOAE measurements at some frequencies were significantly reduced in patients with DM, considering all frequencies meaningful reduction of cochlear function was not observed. This suggests us that in patients with DM, cochlear function was not affected.