Contributing factors to hearing of diabetic patients in an in-hospital education program

In patients with poorly controlled diabetes mellitus (DM), hearing disturbance was associated with renal dysfunction and diabetic neuropathy, represented by decreases in median nerve compound action potential amplitude.

The evaluation was conducted using 43 subjects who were hospitalized for the purpose of DM education. The mean age was 58.1 years (range 21-82 years). The mean HbA1c was 9.5%. The mean DM duration was 11.0 years. Renal function, retina condition, and nerve conduction were evaluated in relation to DM complications (nephropathy, retinopathy, and neuropathy). Nerve conduction studies were used to obtain detailed information on the condition of the peripheral nerves. After otological inspection, pure-tone audiometry, auditory steady-state response (ASSR), and distortion-product otoacoustic emissions (DPOAEs) were measured. Stepwise multiple linear regression was used to analyze the results in the better ear and worse ear.

Decreases in median nerve compound action potential amplitude were associated with deterioration in pure-tone audiometry and ASSR. Diabetic neuropathy, creatinine clearance, diabetic nephropathy, and retinopathy were related to hearing in ASSR and/or DPOAEs.