ABO blood group and auditory brainstem response : a marker for cochlear difference?

Abstract

Objectives: The ABO blood group is genetically determined and plays a prime role in transfusion medicine. Studies have also indicated that ABO blood group may be a contributing risk factor for some diseases, including hearing loss. Among blood groups A, AB, B and O, people with blood group O showed a higher prevalence of hearing loss after exposure to industrial noise than the other three groups. Besides, blood group O individuals with normal hearing also tend to show reduced amplitudes in otoacoustic emission recordings and poorer speech in noise discrimination performance. It is not clear, however, whether ABO blood group status affects auditory brainstem responses (ABR) which reflect bioelectric activities of cochlear hair cells and the auditory nerve. To extend previous research findings, the present study aimed at comparing cochlear function across the four ABO blood groups by recording the cochlear microphonic (CM) and wave I responses in the ABR measurement. Methods: A total of 60 clinically normal hearing young adults were recruited from blood groups A, AB, B and O. There were 15 participants in each blood group. The ABR measurement instrumentation presented a 70 dB nHL click sound as the stimulus, on both rarefaction and condensation polarities. Tiptrodes in the ear canal were applied to record enhanced electrophysiological responses. Recordings of CM amplitudes, wave I amplitudes, and wave I latencies were obtained for both right and left ears. Data were analyzed using one-way ANOVA tests to compare results across the four blood groups. Results: There was a statistically significant difference for wave I amplitudes across the four blood groups. Bonferroni post-hoc comparisons revealed that participants with blood group O had significantly reduced amplitudes of wave I compared to participants with blood group A. There was no significant difference in CM amplitudes or wave I latencies among the four blood groups. However, a consistent trend of reduced CM amplitudes and prolonged wave I latencies was shown in blood group O participants compared to the other blood groups. Conclusions: The study indicated that ABO blood group status may be related with cochlear function due to possible biological differences among the four blood groups. Blood group O individuals might have a higher risk of cochlear synaptopathy compared to non-O blood groups. Further studies should be carried out using various ABR stimulus settings and analyzing a wider range of recording parameters. Larger participant sample sizes should also be involved in future research. Based on the present study and other recent findings, there is emerging evidence that ABO blood group status may influence auditory function.