Dynamic Changes of Auditory Function in Kidney Transplant Recipients: Results of a 12-Month Prospective Observational Study

Abstract

Background: Chronic kidney disease (CKD) is associated with sensorineural hearing loss (SNHL) due to uremic toxins, electrolyte imbalances, and ototoxic medications. Whether kidney transplantation (KTx) reverses or stabilizes hearing impairment remains unclear.
Objective: To prospectively evaluate auditory function in KTx recipients one month before and at 3, 6, and 12 months after transplantation compared to hemodialysis (HD), pre-dialysis CKD, and healthy controls.
Methods: A 12 month prospective study included 160 participants: Group A (CKD stages II–IV, n=40), Group B (CKD stage V on HD, n=40), Group V (KTx recipients, n=40), and Group G (healthy controls, n=40). Pure tone audiometry (PTA), distortion product otoacoustic emissions (DPOAE), and auditory brainstem response (ABR) were performed at each time point. Biochemical markers (creatinine, urea, hemoglobin, electrolytes) were measured.
Results: At baseline, KTx recipients had mean PTA thresholds of 38.4±9.2 dB HL, significantly worse than controls (12.5±3.1 dB HL, p<0.001) but better than HD patients (45.2±10.1 dB HL, p=0.01). By 12 months post transplant, PTA improved to 30.1±8.5 dB HL (p<0.001 vs baseline). DPOAE amplitudes increased from 2.5±1.2 dB to 5.1±1.6 dB (p<0.001). ABR wave V latency shortened from 6.21±0.42 ms to 5.80±0.35 ms (p=0.002). Improvement correlated with decline in serum creatinine (r=0.52, p=0.001) and urea (r=0.48, p=0.003). No significant hearing change occurred in Groups A or B over 12 months.
Conclusion: Kidney transplantation partially reverses SNHL in CKD patients within one year, likely due to elimination of uremic toxins and discontinuation of dialysis related ototoxic factors. Early referral for transplantation may preserve auditory function.