Impairment of auditory function in persons with type 2 diabetes mellitus depending on the level of peripheral myelin protein 22

Abstract

Background. One of the priority tasks of modern medicine is early diagnosis and treatment of micro- and macrovascular complications of diabetes mellitus (DM) which cause a decrease in the quality of life of working age people and an increase in mortali­ty. Variability of carbohydrate metabolism indicators, metabolic dysfunction are leading factors in the development and progression of disabling complications of type 2 DM with hearing loss due to degenerative changes in nerve fibers. An important aspect of diagnostic and treatment algorithms of sensorineural hearing disorders in patients with type 2 DM is early detection of demyelinating processes to prevent damage to neuronal structures. The purpose of the study is to determine the relationship between the level of peripheral myelin protein 22 (PMP 22) and the condition of the auditory analyzer according to the data of instrumental examination in patients with type 2 DM combined with hearing impairment. Materials and methods. There were examined 30 patients with type 2 DM (15 men and 15 women aged 56.28 ± 4.54 years) associated with degree I–II sensorineural disorders of the auditory function; 15 people with signs of sensorineural hearing loss (SNHL) (8 men, 7 women aged 59.33 ± 2.65 years) without diabetes and 15 controls. During the examination, the patients with type 2 DM and SNHL, depending on the severity of the underlying disease, were divided into groups: the first group (n = 15) with or without isolated microvascular complications of type 2 DM, the second group (n = 15) with neuro-, nephro- and retinopathy. All patients underwent a set of laboratory tests to determine the content of PMP 22 in the blood serum, clinical and instrumental diagnosis of the auditory function. The obtained data were processed statistically, and correlations were identified. Results. The analysis of the results revealed that in patients with type 2 DM and SNHL (groups 1 and 2), the level of peripheral myelin protein 22 significantly increased compared to both controls and the comparison group, and more significantly in those with microangiopathies. The correlations were found bet­ween the most informative indicators reflecting the state of various structures of the hearing analyzer and the content of PMP 22 in the blood serum. Conclusions. A significant increase was revealed in the content of PMP 22 and manifestations of sensorineural hearing loss in patients with type 2 diabetes mellitus associated with microangiopathies that indicate demyelinating processes in the neural structures of the auditory analyzer.