Objectives: To evaluate the effects of chronic kidney disease (CKD) and hemodialysis (HD) on the inner ear using the G width (the width between the bimodal peaks of the conductance (G) tympanogram at 2,000 Hz), which reflects the inner ear pressure and/or the existence of endolymphatic hydrops.
Materials and methods: We selected five patients (10 ears) from the patients with CKD who were hospitalized for creation of arteriovenous fistula prior to initiation of HD (non-HD group), and we selected seven patients (14 ears) from the patients with CKD who were undergoing HD (the HD group). As a control group, we selected 80 healthy individuals (160 ears); these were mainly the medical staff of the hospital. We measured the G width of the control group and that of patients with CKD using multifrequency tympanometry.
Results: The mean G widths of the HD (measured just before an HD session), non-HD, and control groups were 210.7, 128.4, and 97.0 daPa, respectively. The G width of the HD group was significantly greater than that of the control and non-HD groups (p<0.01 and p<0.01, respectively; Tukey-Kramer test after one-way analysis of variance). The non-HD group also had a greater G width than the control, but it was not significant (p=0.20; Tukey-Kramer). No significant changes were observed in the G widths of the HD group, just before and after a single HD session (p=0.423; paired t-test).
Conclusion: The greater G width observed in hemodialyzed CKD patients suggests either an increased inner ear pressure or the existence of endolymphatic hydrops in these patients, which is probably related to their otologic symptoms.