Table 1.
Brainstem-evoked response waves, and their origin.
Fig 1.
Potential development of hearing loss in type 1 diabetes mellitus (T1DM).
Based on the results of previous studies [8, 9, 19–23], in T1DM, vasculopathy and neuropathy–both being common complications of T1DM–could have significant role in the development of hearing loss.
Fig 2.
Distortion product otoacoustic emission (OAE) of a control subject and a T1DM patient from the same age group.
The red line shows the background noise, while the green line shows the OAE values (dB SPL) at frequencies between 750 and 8000 Hz. The OAE in the control case is evocable at all measured frequencies, as the OAE values are in the grey/striped (normal) region. In contrast, in the T1DM patient has normal OAE response at the frequencies of 750–2000 Hz, but at 3000, 4000, 6000, 8000 Hz the OAE could not be evoked.
Fig 3.
Acoustically evoked brainstem response waves of a type 1 diabetes patient.
The upper two curves show the results obtained with 90 dB stimulation, whereas the curves on the bottom were generated from 70 dB stimulation. If the wave is present, its number (e.g. I, III, or V) and its latency is marked. I-III-V waves can be seen in both sides by 90 dB stimulus. By 70 dB stimulus, on the right side it is only the V wave and the I and V waves persist on the left side.
Table 2.
Patients’ data.
Table 3.
Clinical data of type 1 diabetes (T1DM) patients within the age groups of 19–39 and 40–60 years of age.
Fig 4.
Mean hearing thresholds of the study groups.
Top: 19–39 years-old groups, bottom: 40–60 years-old groups. T1DM: type 1 diabetes mellitus patients.
Fig 5.
Otoacoustic emissions in the T1DM and control groups.
At the higher frequencies there is a significant difference between the diabetes and the control groups. *: p< 0.05, **: p< 0.01.
Table 4.
OAE signal and noise level results of the distortion product otoacoustic emission measurements in dB SPL.
Table 5.
Acoustically evoked brainstem latencies (in millisecond) of type 1 diabetes patients in the two age groups.