Auditory brainstem responses according to body mass index in women

There are many factors that can contribute to hearing loss. Recently, a new factor has been added to this list; the World Health Organization (WHO) has stated that nutritional status is associated with the etiology of hearing loss. Body Mass Index (BMI), a significant indicator of nutritional status, reflects the extent to which nutrients can meet the body's requirements. The aim of this thesis is to examine the Auditory Brainstem Responses (ABR) of individuals with different BMIs using different stimuli at different intensity levels. A total of 60 female individuals (n=120 ears) within the normal hearing range and aged between 18-40 were included in the study, categorized into three BMI groups. Immittance measurements, pure-tone audiometry, and ABR measurements were conducted. Within the scope of the study, absolute latencies of waves I, III, and V, as well as inter-peak latencies of waves I-III, I-V, and findings between the right and left ears were evaluated using Click and CE-Chirp stimuli at 80-60 dB nHL intensity levels. Significant differences were found between the groups created according to BMI in both stimuli (p<0.05). In the Click stimulus, a significant prolongation in wave V latency at 80 dB nHL was observed in the overweight group, and at 60 dB nHL, a significant prolongation in wave V latency and inter-peak latencies of I-V were observed (p<0.05). In the CE-Chirp stimulus, at 60 dB nHL, significantly shorter absolute latencies of waves I and V, and inter-peak latencies of I-V were obtained in the underweight group (p<0.05). Measurements obtained with the CE-Chirp stimulus were significantly different between groups compared to the Click stimulus (p<0.05). No significant difference was found in inter-aural analysis in the Click stimulus. On the other hand, at 60 dB nHL in the CE-Chirp stimulus, prolongation of the I wave latency in the overweight group, prolongation of the III-V inter-peak latency in the underweight group, and prolongation of the I-V inter-peak latency in the overweight group were observed in the right ear (p<0.05). As a result of this study, it was revealed that ABR measurements, which are influenced by many other factors, are directly related to BMI. The importance of considering BMI when establishing normative data for ABR measurements in adults and/or using ABR in diagnosis has been emphasized.