Potential ototoxicity of aluminum in hemodialysis patients.
OBJECTIVE
Aluminum (Al) is a neurotoxin in both human and animal models. Al accumulation is usually observed in patients with end-stage renal disease (ESRD). To clarify whether Al also exhibits toxic effects on the specified neural organ of inner ear, we recruited hemodialysis (HD) patients to investigate the effect of serum Al level on the auditory physiology.


METHODS
Forty patients in maintenance HD as well as 40 age-matched healthy subjects without hearing complaints were enrolled. The auditory function tests, including pure-tone audiometry (PTA), distortion-product otoacoustic emissions (DPOAEs), and auditory brainstem response (ABR) were performed in all subjects. The serum Al levels determined within 3 months of auditory tests were used for analysis.


RESULTS
High-frequency hearing impairment was the predominant auditory dysfunction in HD patients who showed worse high-tone hearing level on PTA and diminished amplitudes of DPOAEs at 3 K and 4 K as compared with the controls (P < .001). Age was a significant factor determining the auditory dysfunction in both HD patients and control subjects. After age correction, serum Al level correlated reversely with the amplitude of DPOAEs-2 K (P = .002), but not with amplitudes of DPOAEs-3 K, -4 K, hearing levels on PTA, or wave latencies on ABR.


CONCLUSIONS
High-frequency hearing impairment is a common presentation in HD patients. Serum Al level correlates reversely with the amplitude of DPOAEs-2 K but not those of DPOAEs-3 K, -4 K, hearing levels on PTA, and wave latencies on ABR. Possibly, the correlation between the Al level and the high-frequency OAE results was obscured by the significantly diminished amplitudes of DPOAEs-3 K, -4 K in ESRD patients. These results implicate that the effect of Al is mainly of cochlear origin rather than of retrocochlear origin.
Chu
Pei-Lun
PL
Duke University, Durham, North Carolina, USA.
Wu
Chen-Chi
CC
Hsu
Chuan-Jen
CJ
Wang
Yu-Ting
YT
Wu
Kwan-Dun
KD
D000328:Adult; D000367:Age Factors; D000368:Aged; D000535:Aluminum / Q000009:adverse effects* / Q000097:blood; D003056:Cochlear Nerve / Q000187:drug effects*; D007758:Ear, Inner / Q000187:drug effects*; D005260:Female; D006316:Hearing Loss, High-Frequency / Q000139:chemically induced*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects; D006435:Renal Dialysis / Q000009:adverse effects*
D000535:Aluminum