Topicality: Objective research methods of the auditory analyzer are of great importance in diagnosis sensorineural disorders of auditory function, treatment of such diseases and solving a number of expert questions. While diagnosis the damage of auditory system, especially the receptor part of the auditory analyzer the method of the caused OAE on the frequency distortion product (DPOAE) plays a significant role. Quite often at sensorineural hearing loss of different genesis is observed an affection of cochlea structures of the inner ear. Diabetes mellitus (DM) is one of the most acute medical and social problems. According to the latest data, there are 463 million adults with diabetes mellitus in the world; accounting for 9.3% of the world's total population, meaning that 1 among 11 people suffers from diabetes (IDF Diabetes Atlas 9th edition, 2019). Among patients with diabetes, according to various authors, there are disorders in the auditory analyzer. Purpose: to determine changes in the condition of the receptor part of auditory analyzer according to the OAE registration of the frequency of distortion products among patients with diabetes mellitus type II with impaired auditory function. Materials and methods: 17 patients with diabetes mellitus type II were examined, who, according to subjective audiometry, revealed impairments of auditory function of the I-II degree. The control group consisted of 15 healthy normal-hearing persons who did not report hearing impairment, had no elevated blood sugar levels. 32 persons were examined in total. The registration of the caused OAE at frequency of distortion product (DPOAE) was conducted on the analyzing system "Eclipse" "Interacoustics" (Denmark) at frequencies 1-6 kHz. Statistical processing of the obtained results was carried out according to the conventional methods of mathematical variation statistics using the STATISTICA software package. The average value of indicators was calculated - magnitude (M) and its error (+- m). The probability of changes and differences between the comparative values was estimated by the criterion for the reliability of the difference (t) according to the Student's table. Results and discussion: We have selected for the analysis patients with diabetes mellitus type II, who according to subjective audiometry revealed impaired auditory function. Patients also reported otologic complaints of hearing loss, periodic or persistent subjective ear noise. As a result of the OAE researches at frequency distortion products, the following data were obtained. A full adequate response of the otoacoustic emission across all frequency spectrums was reported in only 3 patients (9.4% of cases) on the one hand. The majority of the observed patients in whom the OAE was registered received a partially positive test (68.7%). In 7 patients (21.8%) the OAE response was not registered. The absence of OAE response or a partially positive registration in 90.6% of the observed patients indicated violation function of the cochlea in such patients. The DPOAE (response intensity) emission amplitude at all tested frequencies (1-6 kHz) in patients with diabetes mellitus type II was significantly (P<0.01) lower than the norm at all frequencies. Particularly pronounced such a decrease is in the area of 4 kHz, where the amplitude of the OAE response was 5.9±0.2 dB at a norm of 9.4±0.5 dB. Therefore, in patients with diabetes mellitus type II with hearing impairment, there are changes in the receptor part of the auditory analyzer, which is confirmed by the data of objective examination methods. The changes we have identified in the OAE indicators may express the affection of the receptor structures of the auditory analyzer among patients with diabetes mellitus type II with impaired auditory function. The information obtained on the OAE indicators provides the detection of early violations and the objective ascertainment of changes in the receptor part of the hearing analyzer in diabetes mellitus type II. Conclusions: 1. OAE data on the frequency of distortion products in patients with diabetes mellitus type II objectively confirm the presence of violations in the auditory receptor. 2. In patients with diabetes mellitus type II, the OAE amplitude at the frequency of distortion products is significantly lower than normal at all tested frequencies (1-6 kHz). Particularly pronounced such a decrease is in the area of 4 kHz, where the amplitude of the OAE response was 5.9±0.2 dB at a norm of 9.4±0.5 dB. 3. The conducted researches prove the expediency of examination by the method of registration of OAE of patients with diabetes mellitus type II, since it promotes the early detection of violation in the receptor structures of the auditory analyzer in such patients. 4. The use of the method of recording otoacoustic emissions in the examination of patients with type II diabetes is important for the objectification of early signs of sensorineural hearing impairment in this contingent.

Topicality: The sensorineural hearing loss (SNHL) is a polyetiological disease with a complex pathogenesis. Sensorineural hearing loss is also caused by metabolic disorders and system diseases, including diabetes mellitus (DM).Quite often at sensorineural hearing loss there are extraauralic manifestations of the central nervous system (CNS). On the other hand, with diabetes, there are also observed the affection of the nervous system both in the form of polyneuropathy and certain disorders of the CNS. Electroencephalography (EEG) is a reliable, universal, objective, non-invasive method of research the functional condition of the CNS. Aim: to investigate changes in the condition of bioelectrical activity of the brain according to electroencephalography among patients with diabetes mellitus type II with impaired auditory function. Materials and methods: 43 patients with diabetes mellitus type II were examined, who, according to subjective audiometry, revealed impairments of auditory function and 15 persons of the control group. The EEG research was performed using a computer electroencephalograph from the company “DX-System” (Ukraine) according to the generally accepted method. Results and discussion: The qualitative analysis of EEG results among patients with diabetes revealed abnormalities in the functional condition of the CNS in the form of diffuse changes in bioelectrical activity of the brain, disorganization and desynchronization of basic rhythms, signs of irritation of brain structures, amplified by functional loads. Among the examined patients using background EEG we observed the expressed irritative changes, decrease in bioelectrical activity of a brain, desynchronization and disorganization of rhythms. Among many of them there were periodic sharp peaks and potentials, a tendency to accelerating the basic rhythm, and against this background, the increase in the content of slow waves (theta), mainly in the front leads. Moreover, the most pronounced changes in bioelectrical activity took place in the temporal and frontal leads. Thus, in patients with diabetes mellitus type II with SNHL disorganization and desynchronization of the EEG picture was detected in 34 patients (79.1 % cases). The expressed irritative changes were registered in 39 persons (90.6 % cases), hypersynchronous bursts were detected in 15 patients (34.8%), sharp peaks and potentials were present in 21 person (48.8 %) Many patients had smoothed zonal differences – 25 persons (58.1%) and lack of reaction to eye opening – 15 patients (34.8%)The decrease of bioelectrical activity reached 86.0 % cases. The amplitude of the basic alpha rhythm of the EEG among the examined patients diabetes mellitus type II with SNHL is significantly (p<0.01) lower than the norm in the temporal, parietal and occipital leads, which was 31.8±2.5, 44.1±3.1 and 43.5±4.2 мkV, respectively. In a significant part of the examined patients (88.3 %) with hearing impairments on the background of diabetes mellitus type II, these manifestations were increasing by hyperventilation. Violations of bioelectrical activity of the brain in 97.6% of cases were symmetrical, which indicates diffuse cerebral changes in the functional condition of the CNS in this category of patients. Irritations of the cortical structures of the brain were registered in all examined patients with diabetes mellitus type II. In many of these patients (97.6%) cortical irritation was combined with the involvement of deep brain structures. Thus, dysfunction of the diencephalic structures of the brain occurred in 48,8% of cases, diencephalic-stem – in 39,5%, mediobasal – in 9.3% cases. Only one patient had irritation of only the cortical structures. So, among our examined patients with diabetes mellitus type II with impaired auditory function according to EEG there are pronounced violations of bioelectrical activity according to EEG, including changes in the cortical and deep - diencephalic and stem structures of the brain. Conclusions: 1. The researches made by EEG method in patients with diabetes mellitus type II and SNHL objectively confirm the violation of the functional condition of the CNS among such patients. 2. In patients with diabetes mellitus type II and SNHL there are changes in bioelectrical activity mainly in the form of decreasing of bioelectrical activity of the brain (86,0%), expressed irritative changes (90.6%), irritation of deep structures of the brain (97,6), disorganization and desynchronization of the EEG picture (79.1% cases). 3. In patients with SNHL on the background of diabetes mellitus type II there is significantly (p<0.01) lower decreasing of amplitude of the alpha rhythm in comparison with the control values in temporal, parietal and occipital leads to 31.8±2.5, 44.1±3.1 and 43.5±4.2 mkV, respectively.

Topicality: While diabetes mellitus is often observed hearing impairment, including sensorineural hearing loss (SNHL). On the other hand, metabolic changes, disorders of the hemostasis system, lack of vitamins and minerals can lead to the development of SNHL. Aim: to examine the level of peripheral myelin protein (PMP) and vitamin D in patients with diabetes mellitus type II with hearing impairment. Materials and methods: Were examined 43 patients with diabetes mellitus type II, who, according to subjective audiometry, revealed SNHL of the I-II degree according to the International Classification. We divided patients into two groups: group 1st included 22 patients without complications, group 2nd – 21 patients with complications of diabetes mellitus and sudden changes in blood sugar levels in the anamnesis. As a comparison group were examined 15 patients with SNP without high blood sugar. The control group consisted of 15 healthy individuals. Results and discussion: When analyzing the results of the study, it was found that in patients with diabetes mellitus and SNHL (groups 1st and 2nd) there was a significant increase of the level of PMP comparing with the control and the comparison group. Moreover, in group 2nd (with complicated diabetes mellitus) the increase of the level of PMP in the blood serum was reliably more significant than in group 1st. In patients with diabetes mellitus group 1st the level of PMP was from 2.3 to 9.8 ng/ml (average value of 7.2±0.5 ng/ml), in group 2 PMP had a level of 8.5 to 37.2 ng/ml (average value of 24.3±1.7 ng/ml). This is significantly (P<0.01) more than in the control group. Elevated levels of PMP in patients with diabetes mellitus may indicate the processes of demyelination, damage of neural structures, which are more pronounced in the complicated course of diabetes, which, obviously, have some significance in the development of SNHL in diabetes mellitus type II. As for the content of vitamin D, certain reductions in its level were observed in all groups of examined patients with SNHL. However, in patients with SNHL without diabetes mellitus, this decrease was not differing significantly from the control values. But in both groups of patients with SNHL on the background of diabetes mellitus, this difference was significant, especially in group 2nd. Decreasing the level of vitamin D in blood serum, more expressed at the complicated course of diabetes mellitus in patients with SNHL testifies of a certain role of this vitamin in deepening of metabolic disturbances at such patients, and consequently – faster and more expressed development of complications. While the analysis of the distribution of patients with deviation of PMP level and vitamin D, it was found that in groups of patients with diabetes, especially in group 2nd with a complicated course, in blood serum there was significantly more often than in the comparison group a lack of vitamin B and increasing of PMP. Moreover, in group 2nd deviations from the norm in the level of PMP were also significantly more often than in group 1st. In the group of SNHL without diabetes mellitus (group 3rd) vitamin D deficiency was observed only in 13.3% of cases. A deficiency of vitamin D in group 2nd occurred significantly more often not only comparing with the control and comparison group, but also relatively to group 1st, with a milder course of diabetes. Thus, in group 2nd in patients with diabetes and SNHL, the lack of vitamin D occurred in 26.6% and its deficiency – in 73.3% of cases. In general, a decrease of vitamin D levels occurred in 100% of patients in group 2nd and in 80% in group 1st, while in group 3rd – 30%. Thus, researches have shown that in all studied groups of patients with SNHL on the background of diabetes mellitus type II there are deviations from the norm in the content of PMP and vitamin D in the blood serum. Moreover, the most pronounced disorders were found in the examined, who also had a complicated course of diabetes mellitus type II, the episodes of hypoglycemia in the anamnesis. This indicates the possible role of a complicated course of diabetes mellitus type II on the development of disorders (including demyelinating processes) in the neural structures of the auditory analyzer. Conclusions: In patients with diabetes mellitus type II and sensorineural hearing loss there is a significant increase in the content of PMP in blood serum, more pronounced in complicated diabetes, which may indicate the processes of demyelination and damage of neural structures. In patients with sensorineural hearing loss on the background of diabetes mellitus type II there is a significant (P <0.01) reduced levels of vitamin D compared with the control, the severity of reducing indicates its lack and even deficiency, especially occurred on the background of complications of diabetes mellitus. Patients with diabetes mellitus type II with sensorineural hearing loss, who have a complicated course, polyneuropathy, episodes of a severe changes of sugar levels in anamnesis, there is a significant (P<0.05) more pronounced increasing levels of PMP and decreasing of vitamin D than in patients with milder course of disease. The obtained data may indicate an important role of demyelinating processes and vitamin D deficiency in the development of sensorineural hearing impairment among patients with diabetes mellitus type 2.

The purpose of our study is to examine the condition of brainstem part of the auditory analyzer based on examination of the short-latent auditory evoked potentials (SLAEP) in 43 patients with diabetes mellitus (DM) type 2 with disorders of auditory function. We revealed sensorineural hearing loss (SNHL) of the I-II degree according to the internation- al classification. The registration of SLAEP was conducted by the system «Eclipse» «Interacoustics» (Denmark). We detected a lengthening of the latent periods of the peaks (LPP) of the II, III, IV and V waves of SLAEP, as well as the inter-peak intervals of I-III and I-V comparing to the control values. So, LPP of III wave SLAEP was 3.85 ± 0.04 ms, and of V wave was 5.83 ± 0.05 ms. According to the severity of DM type II, we divided the patients into two groups: without (group I) and with (group II) complica- tions. A comparative analysis revealed that the values of LPP III wave and also I-III in group 2 not only significantly exceeded the normal values, but also significantly differed from the same indicators in group 1. Thus, the LPP of the III wave of SLAEP was 3.81 ± 0.03 and 3.95 ± 0.05 ms, in group 1 and 2, respectively. In group 2 inter-peak interval I-III was 2.29 ± 0.03 ms, inter-peak interval I-V was 4.21 ± 0.04 ms. This indicates the possible influence of the complicated course of diabetes mellitus II on the development of disorders in the central departments of the auditory analyzer, particular in its brainstem structures. Therefore, among all studied groups of patients with SNHL on the background of DM type II there are a pronounced deviations from the norm in the state of the brainstem part of the auditory analyzer. The obtained data indicate an important role of the state of brainstem part of auditory analyzer in the development of sensorineural hearing disorders in diabetes mellitus type II.