Infuence of HbA1c, serum lipids, blood pressure and BMI on Auditory Brainstem Response in diabetic patients

Introduction. Impaired hearing organ function including abnormalities in auditory brainstem response (ABR) are more frequent in diabetic subjects compared to the general population. The aim of our study was to assess the impact of selected modifiable factors on ABR latencies in diabetic subjects. Material and Methods. 58 patients with type 1 and type 2 diabetes, aged <45 years, with diabetes duration <10 years, and without clinically overt hearing impairment or diabetic neuropathy, were included. In all subjects vital signs and blood samples were obtained, and ABR audiometry was performed. Results. Significantly delayed latencies in ABR were found in patients with total cholesterol <192 mg/dL, with HDL-cholesterol <49.5 mg/dL, with triglycerides >89 mg/dL, with presence of hypertension, and with systolic and diastolic blood pressure >135 and >78 mm Hg respectively. A linear correlation between triglycerides and wave I and III latencies, and between systolic blood pressure and wave III latency were revealed. A relationship between ABR latencies and HbA1c, LDL-cholesterol or BMI was not found. Conclusions. Several modifiable factors affect functioning of the retrocochlear part of the auditory pathway. If these results were confirmed in further studies, a vast area of possible therapeutic interventions to preserve hearing function in diabetic patients would become available.