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Nisa Maruthur, M.D., M.H.S.
06-15-2010
- Refers to either: 1) sensorineural hearing impairment, characterized by frequency and intensity of hearing loss or 2) conductive hearing loss.
- In diabetes, the increased prevalence of sensorineural hearing impairment likely related to microvascular disease
- In those with diabetes, overall likelihood of sensorineural hearing impairment approximately 2 times that in those without diabetes (Bainbridge)
- Both low- and high-frequency hearing impairment far more common among those with diabetes
- Age-adjusted prevalence of mild or greater high-frequency hearing impairment among those with diabetes is 54.1%
- Age-adjusted prevalence of mild or greater low-frequency hearing impairment among those with diabetes is 21.3%
- Age, noise, ototoxic medications, and smoking increase risk of hearing impairment along with presence of microvascular conditions
- History: presence or absence of subjective hearing impairment, timing, occupational history, trauma, medications, family history, family member response
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Self-report: defined by audiometry pure-tone threshold. "Yes" response has likelihood ratio (LR) positive of 2.5 (95% CI 1.7 to 3.6). "No" response has LR negative of 0.13 (95% CI 0.09 - 0.19). Family member response may have some value.
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Whispered voice perception: standing behind patient with untested ear occluded by examiner's finger, examiner whispers combination of 3 numbers and letters and can repeat once more. Normal if 3/6 letters or numbers repeated by patient. Inability to perceive whispered voice has LR positive of 6.1 (95% CI 4.5 - 8.4). Normal perception has LR negative of 0.03 (95% CI 0-0.24).
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Weber test: positive if tuning fork vibrating on middle of forehead perceived as louder on one side (lateralization). Suggests conductive hearing loss on loudest side or sensorineural loss on diminished side. Not useful if bilateral, symmetric hearing loss since the test depends on lateralization. Abnormal result: LR positive of 1.6 (95% CI 1.0 - 2.3).
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Rinne test: to evaluate for conductive hearing loss, place vibrating tuning fork on mastoid process (bone conduction, BC) until sound is not heard, then move to 1 inch from external meatus (air conduction, AC) to see if sound still heard. Normal: AC>BC. Abnormal test: LR positive 2.7 to 62. Normal test: LR negative 0.01 to 0.85.
- Evaluate for other medical causes of hearing impairment such as syphilis (i.e. fluorescent treponemal antibody absorption test).
- Otoscopy to evaluate external ear canal and tympanic membrane
- Imaging with MRI or CT to evaluate for acoustic neuroma or other abnormality
- Referral for audiologic examination by audiologist
- Progressive difficulty hearing at low or high-frequencies and/or different sound intensities
- Difficulty hearing as evidenced by self-report, whispered voice perception, Weber or Rinne tests
- May have associated vertigo or tinnitus
- Treatment of external and middle ear disorders (e.g., cerumen impaction and otitis media)
- Avoid/discontinue ototoxic medications (e.g. aminoglycosides, loop diuretics, salicylates and nonsteroidal antinflammatories, vancomycin, and erythromycin).
- Consultation with audiologist and/or otolaryngologist for hearing aids and other hearing assistive devices.
- Inquire about subjective hearing impairment every 6 months during regular diabetes follow-up visits
- Input from family members may be helpful in determining presence and extent of hearing impairment
- Though there is no convincing data at this time, if diabetes-related hearing loss is indeed due to microvascular disease, blood pressure and glycemic control should play a role in prevention and treatment of this complication.
- Comparison of initial office-based tests for hearing impairment suggests that Weber and Rinne tests have limited value and that referral for audiometry should be based on patient's subjective report of hearing loss and/or abnormal whispered-voice test (Bagai).
- Severe, congenital or maternally transmitted deafness should raise possibility of "mitochondrial diabetes"
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