Hearing Thresholds and Serum Apelin Levels in Patients with Vertebrobasilar Insufficiency

Abstract

Objective: Vertebrobasilar insufficiency (VBI) is a clinical entity that results from the decrease in flow volumes due to hemodynamic changes in the vertebral artery and its branches. Herein, we aimed to investigate the hearing thresholds and serum apelin levels in VBI patients who were admitted to our clinics with vertigo. Methods:Patients who were admitted to our clinics with vertigo were included in our study. They underwent bilateral carotid and vertebral artery color Doppler ultrasound investigation to determine VBI. Then, they were grouped into two groups: having VBI or not. Pure tone audiometry tests between 2500-8000 Hertz (Hz) were applied, and plasma levels of apelin, routine biochemistry parameters, and levels of C-reactive protein were studied in these patients.Results: Thirty-eight (47% women, mean age 57.6±9.3) patients with VBI and 24 controls (50% women, mean age 57.0±10.1) were included. In patients with VBI, hearing thresholds were higher in the left ear except at the 500 Hz frequency. Serum apelin levels were not statistically different between the 2 groups. Conclusion:In this study, several abnormalities in hearing tests were determined in VBI patients. The hypothesis was that basilar artery dysfunction caused by asymmetry of vertebral artery flow volumes in VBI might increase apelin levels, which have functions in angiogenesis, hemostasis, and cardiovascular hemodynamics. However, we could not find a significant difference in apelin levels between the 2 groups. This result was thought to be due to the absence of severe hemodynamic abnormalities and atherosclerosis in the study groups.