Patients with diabetes are more than twice as likely as those without the disease to have hearing loss, according to a recent National Institutes of Health (NIH) study. More than 34 million Americans are affected by hearing loss, which can be fully corrected in 95% of all cases. Many of those affected are people with diabetes. “Nearly 100 percent were unaware that hearing loss was associated with diabetes, had never received a physician’s recommendation for a hearing test, and were enthusiastic about knowing their results, Mr. Tysoe added.” Only 16% of physicians routinely screen for hearing loss, according to the Center for Hearing and Communication.

Presbycusis – age-related hearing loss – is the number one communicative disorder and a significant chronic medical condition of the aged. Little is known about how type II diabetes, another prevalent age-related medical condition, and presbycusis interact.

Research showed that the majority of differences between the hearing abilities of the aged diabetics and their age-matched controls were found in measures of inner ear function. For example, large differences were found in pure-tone audiograms, wideband noise and speech reception thresholds, and otoacoustic emissions. The greatest deficits tended to be at low frequencies. In addition, there was a strong tendency for diabetes to affect the right ear more than the left. One possible interpretation is that as one develops presbycusis, the right ear advantage is lost, and this decline is accelerated by diabetes. In contrast, auditory processing tests that measure both peripheral and central processing showed fewer declines between the elderly diabetics and the control group. Consequences of elevated blood sugar levels as possible underlying physiological mechanisms for the hearingloss are discussed.

1. Jordao AMD. Consideration sur un cas du diabete. Union Medicale du Paris 1857;11:446.
2. Edgar TO. Klinische Untersuchungen uber die Erkrankungen des Gehororgans bei Diabetes Mellitus mit besonderer Berucksichtigung der Erkrankungen des inneren Ohres. Mschr Ohrenheilk LaryngoRhinol 1915;49:225–60.
3. Harner SG. Hearing in adult-onset diabetes mellitus. Otolaryngol Head Neck Surg 1981;89:322–7.
4. Celik O, Yalcin S, Celebi H, et al. Hearing loss in insulindependent diabetes mellitus. Auris Nasus Larynx 1996;23:127–32.
5. Cullen JR, Cinnamond MJ. Hearing loss in diabetics. J Laryngol Otol 1993;107:179–82.
6. Schuknecht HF. Pathology of the Ear. 2d ed. Philadelphia: Lea & Febiger, 1993;312.
7. Axelsson A, et al. Hearing in diabetics. Acta Otolaryngol 1978;356(Suppl):3–21. Otology & Neurotology, Vol. 24, No. 3, 2003
8. Huang YM, Pan CY, Gu R, et al. Hearing impairment in diabetics. Chin Med J 1992;105:44–8.
9. Snashall SE. Bekesy audiometry and tone and reflex decay tests in diabetics. Arch Otolaryngol 1977;103:342–3.
10. Taylor IG, Irwin J. Some audiological aspects of diabetes mellitus. J Laryngol Otol 1978;92:99–113.
11. Wackym PA, Linthicum FH Jr. Diabetes mellitus and hearing loss: clinical and histopathologic relationships. Am J Otol 1986;7: 176–2.
12. Schuknecht HF. Pathology of the Ear. 2nd ed. Philadelphia: Lea & Febiger, 1993;416.
13. Duck SW, Prazma J, Bennett PS, et al. Interaction between hypertension and diabetes mellitus in the pathogenesis of sensorineural hearing loss. Laryngoscope 1997;107:1596–604.
14. Foster D. Harrison’s Principles of Internal Medicine. 12th ed. New York: McGraw-Hill, 1991;1754–5.
15. Makishima K, Tanaka K. Pathological changes of the inner ear and central auditory pathway in diabetics. Ann Otol Rhinol Laryngol 1971;80:218–28.
16. Jorgensen MB. The inner ear in diabetes mellitus. Arch Otolaryngol 1961;74:373–81.
17. van den Ouweland JM, Lemkes HH, Tremblath RC, et al. Maternally inherited diabetes and deafness is a distinct subtype of diabetes and associated with a single point mutation in the mitochrondrial tRNA (LeuUUR) gene. Diabetes 1994;43:746–51.
18. Kadowaki T, Kadowacki H, Mori Y, et al. Subtype of diabetes mellitus associated with a mutation of mitochondrial DNA. N Engl J Med 1994;330:962–8.
19. Lisowska G, Namyslowski G, Morawski K, Strojek K. Early identification of hearing impairment in patients with type 1 diabetes mellitus. Otol Neurotol 2001;22:316–20.
20. Smith TL, Raynor E, Prazma J, et al. Insulin-dependent diabetic microangiopathy in the inner ear. Laryngoscope 1995;105:236–40.
21. McQueen CT, Baxter A, Smith TL, et al. Non-insulin-dependent diabetic microangiopathy in the inner ear. J Laryngol Otol 1999; 113: 13–8.
22. Nageris B, Hadar T, Feinmesser M, et al. Cochlear histopathologic analysis in diabetic rats. Am J Otol 1998;19:63–6.