Background: Hearing loss has been described in patients with chronic renal failure on regular dialysis treatment (RDT) with very different frequency, ranging from 20 to 75%; RDT does not seem to worsen hearing function for at least the first 5 years of treatment; no studies are available on patients on RDT for more than 10 years.
Methods: We performed an audiometric evaluation in 91 patients on RDT for various periods: group I (34 patients), < 5 years; group II (32 patients), 5-10 years; group III (25 patients), > 10 years; patients with histories of chronic otitis, ototoxic drug treatment, and chronic auditory trauma were excluded; the possible correlations with some biochemical parameters (urea, creatinine, PTH) were also looked for.
Results: Hearing loss was present in 77% of patients and 69.2% of ears; the percentage of patients with hypoacusia was higher in group III (84%) than in group I (76.3%) and II (71.7%), but the differences were not statistically significant. Hypoacusia was cochlear neurosensory in 61.5%, conductive in 6.5%, and mixed in 9.0% of patients; the percentage of patients with cochlear neurosensory hypoacousia was similar in the three groups (I, 61.7%; II, 59.3%; III, 64%). Hearing loss was of slight to moderate degree and not different in the three groups (I, 22.7 +/- 15 dB; II, 26.9 +/- 6.0 dB; III, 29.1 +/- 8.9 dB). There were no correlations between hearing loss and plasma creatinine and PTH values; patients with plasma urea > 200 mg/dl had higher percentage of hypoacousia (86%) than patients with plasma urea < 200 mg/dl (69%) (P = 0.06).
Conclusions: Hearing loss, mainly cochlear neurosensory in type, is present in a high percentage of patients on RDT even at the beginning of treatment, but no negative effects on hearing can be correlated with the duration of dialysis.