Hearing Loss as a Complication of Type 2 Diabetes
If you have type 2 diabetes, you may or may not have experienced hearing loss or changes in your ability to distinguish sounds or speech. In either case, the findings of the new study as well as previous research should be of interest.
New study on hearing loss and diabetes
This study included 104 adults who had type 2 diabetes and 104 controls who did not have the disease. All of the participants were given audio (ear) tests, including
- Pure-tone audiometry, which identifies the softest sound a person can hear at least half the time
- Speech recognition, which includes the softest level at which a person can recognize words
- Vestibular function tests, which include a series of tests of the semicircular canals in the ear and balance
- Impedance audiometry, which tests the function of the middle ear
The investigators found statistically significant alterations in the vestibular function tests among people with type 2 diabetes when compared with controls. In a particular test (saccade test), patients who had had type 2 diabetes for more than 7 years were significantly more likely to fail than those who had had the disease for less than 7 years.
Saccades are eye movements people use to quickly refixate from one object to another. The saccade test involves looking from one target to another without moving the head.
In a meta-analysis from McGill University, 18 studies were reviewed. Overall the reviewers found that the incidence of hearing loss among people with type 2 diabetes ranged from 44 percent to 69.7 percent, which was 1.5 to 2.5 times greater than seen in controls. They also concluded that age and how long a person had lived with type 2 diabetes were important factors in the occurrence of hearing loss associated with diabetes.
A study appearing in the North American Journal of Medical Sciences looked at changes that occur in the brainstem auditory evoked potentials (BAEP) in people with type 2 diabetes. A BAEP test measures how the brain processes sounds by recording brainwaves in response to clicks or other tones. The test is used to help diagnose hearing loss and damage to the nervous system.
In this study, 126 men with type 2 diabetes and 106 matched controls underwent BAEP testing. Test results indicated that BAEP testing can detect early problems with hearing in individuals with type 2 diabetes.
Various other earlier studies have pointed to a connection between hearing loss and having type 2 diabetes. As was noted by one researcher in Japan, “it is believed that over time, high blood glucose levels can damage vessels…and nerves diminishing the ability to hear.”
If you or a loved one has type 2 diabetes (or type 1 diabetes), it’s a good idea to have your hearing checked. It may be time to add hearing loss to the list of complications of diabetes.
Akinpelu OV et al. Is type 2 diabetes mellitus associated with alterations in hearing? A systematic review and meta-analysis. Laryngoscope 2013 Aug 14
Gupta S et al. Brainstem auditory evoked potential abnormalities in type 2 diabetes. North American Journal of Medical Sciences 2013 Jan; 5(1): 60-65
Horikawa C et al. Diabetes and risk of hearing impairment in adults: a meta-analysis. Journal of Clinical Endocrinology & Metabolism 2013 Jan.
Ozel HE et al. Audiovestibular functions in noninsulin-dependent diabetes mellitus. Acta Otolaryngology 2013 Oct 16. Epub ahead of print