Hearing impairment in middle-aged patients with diabetes

Most studies focus on elderly patients with type 2 diabetes mellitus (T2DM). There is little known about the hearing of middle-aged subjects with T2DM. The objective of this study is to evaluate hearing impairment in patients aged 40-50years with T2DM using pure-tone audiometry and high-frequency audiometry. Forty patients with T2DM (19 males, 21 females) and 40 (20 males, 20 females) age and sex similar controls were included. All subjects completed clinical, laboratory and auditory assessments. Pure-tone audiometry auditory tests and high-frequency audiometry tests were performed in a soundproof room for each ear using the AC-40 audiometer from Interacoustics with a special earphone appropriate for high frequency. In the T2DM group, the duration of T2DM was between 5 and 15years (7.7 +/- 2.4 years). At all frequencies, the thresholds of the T2DM group were higher than the control group for both right and left ears and also significant. However, the thresholds at standard frequencies (125-8000 Hz) for both group's average were lower than 20 dB-HL and were considered to be normal, and at high frequencies (9000-16,000 Hz) the T2DM group's average thresholds were higher than 20 dB-HL and considered to be a hearing loss. A Spearman's correlation test was done between the duration of T2DM and hearing thresholds. There was a mild correlation between the duration of T2DM and hearing thresholds in all frequencies. In conclusion, patients with type 2 diabetes have a high prevalence of subclinical sensorineural hearing loss. High-frequency audiometry can be used in hearing assessment screening of diabetic patients.