Hearing loss is not merely for seniors or those with noise exposure but is also associated with other medical conditions. There is emerging evidence for the association between hearing loss and many health conditions. The prevention of hearing loss is yet another reason to pursue a healthy lifestyle.
Diabetes is a metabolic disease that has well known complications including vision loss, kidney failure, and loss of sensation in the feet, particularly if the diabetes is poorly controlled. Routine monitoring of these systems helps detect and address deficits early. Less attention is given to the association between diabetes and hearing loss.
Hearing loss is more prevalent in people with diabetes. Studies have shown that diabetes damages the inner ear. Like many organs that become impaired in people with diabetes, the association with hearing loss is likely due to the effects of elevated blood sugar and inflammatory changes in small blood vessels and nerves in the auditory system.
Routine audiological evaluation in diabetic patients allows early detection of hearing loss, which can improve communication and quality of life. While it is recommended that everyone have an audiological evaluation it is especially important for individuals newly diagnosed with diabetes. Undetected hearing loss can lead to depression, isolation and can put a strain on relationships with family and friends.
Presbycusis, or age-related hearing loss, is a well-known phenomenon but there is great deal of variation in hearing abilities among older adults. This variation may be in part due to difference in cardiovascular health in this population. Good cardiovascular health is associated with better hearing and recent studies have found that individuals over the age of 50 with good cardiovascular health have better hearing sensitivity than those with poor cardiovascular health. Fitness levels may act to preserve hearing sensitivity in old age.
Hearing can be impacted by many different factors and living a healthy lifestyle may contribute to the prevention of hearing loss later in life.
As we age there a lot of changes in both the ear and in the brain that can impact the way we hear. The auditory system is made up of the outer ear, the middle ear, the inner ear and the brain. Age-related changes can occur in each but most of the changes take place in the inner ear and brain. The inner ear contains hair cells that are susceptible to damage as we age, particularly affecting how we hear high-pitched sounds. In the brain, neural slowing occurs that can be attributed to cellular changes in neurons, which transmit and process information. A combination of changes in the inner ear and brain cause age-related hearing loss.
The normal aging process also affects such skills as selective attention, short-term memory, processing speed, reaction time and sensitivity to soft sounds. Many of these help us to carry on conversations, to localize sound and aid in the ability to hear in noisy settings. The brain processes sound and with age seniors are not able to use the brain as efficiently as younger adults. As a result, there is more difficulty organizing sound into meaningful information.
Age-related changes in the auditory system reflect the importance of regular hearing tests for seniors. Hearing loss left untreated can cause depression, anxiety, insecurity and decreased social activity. Hearing aids can relieve many of these negative symptoms and have been known to improve communication and emotional well-being.
Hearing loss and dementia is a hot topic in the field of audiology. Dementia can be devastating to both individuals and families. Some risk factors for dementia include low social interactions and activities, sedentary lifestyle, diabetes and hypertension. Research has now identified a possible connection between dementia and hearing loss. Hearing loss is independently associated with dementia when adjusted for age, sex, education, race, smoking, diabetes and hypertension. In particular, hearing loss was associated with lower scores on tests of executive function and memory. Tests were completed in a quiet room, face-to-face and with an examiner who is familiar working with older adults.
While the connection between hearing loss and dementia is unknown at this time it may be caused by several different mechanisms. First, hearing loss and dementia may have common neuropathologic process. Second, hearing loss may cause a decrease in cognitive reserve. In other words, the burden of difficult listening environments over time in those with hearing loss may put a strain on such processes as working memory. Third, social isolation and/or loneliness as a result of hearing loss may contribute to a higher risk of dementia. Studies have shown that individuals who are active and engaged have a lower dementia risk. If hearing loss and dementia are related through this mechanism it is possible that hearing aids and aural rehabilitation may play a role in the prevention of dementia. This would have far reaching applications and an area that warrants further study.
Unrecognized hearing loss can be mistaken for cognitive decline. Many screening and diagnostic tests for dementia require the patient to listen to a set of instructions thus cognitive decline can be overestimated with hearing loss. Hearing loss and dementia often coexist in seniors but individuals with dementia are not always treated for hearing loss. With the assistance of a spouse, family member or care worker hearing aid fittings can be successful. Individuals with dementia wearing hearing aids are more alert, easier to communicate with and more aware of their environments.
Alessio, H., Hutchinson, K., Price, A., Reinart, L. & Sautman, M. (2002). Study finds higher cardiovascular fitness associated with greater hearing acuity. Hearing Journal, 55(8), 32-40.
Bainbridge, K., Cheng, Y., & Cowie, C. (2010). Potential mediators of diabetes-related hearing impairment in the U.S. population: National health and nutrition examinations survey 1999-2004. Diabetic Care, 33, 811-16.
Cheng, Y., Gregg, E., Saaddine, J., Imperatore, G., Zhang, X. & Albright, A. (2009). Three decade change in the prevalence of hearing impairment and its association with diabetes in the United States. Preventative Medicine, 49, 360-364.
Fukushima, H., Cureoglu, S., Schachern, P., Kusunoki, T., Oktay, M., Fukushima, N., Paparella, M. & Harada T. (2005). Cochlear changes in patients with type 1 diabetes mellitus. Otolaryngology Head and Neck Surgery, 133(1), 100-106.
Fukushima, H., Cureoglu, S., Schachern, P., Paparella, M., Harada T. & Oktay, M. (2006). Effects of type 2 diabetes mellitus on cochlear structure in humans. Archives Otolaryngology Head and Neck Surgery, 132(9), 934-38.
Hutchinson, K., Alessio, H. & Baiduc, R. (2010). Assosiation between cardiovascular health and hearing function: pure-tone and distortion product otoacoustic emission measures. American Journal of Audiology, 19 (1), 26-35.
Lin, F., Ferrucci, L., Metter, E., An, Y., Zonderman, A., & Resnick, S. (2011). Hearing loss and cognition in the Baltimore longitudinal study of aging. Neuropsychology, 25(6), 763-770.
Lin, F., Metter, E., O’Brien, R., Resnick, S., Zonderman, A., & Ferrucci, L. (2011). Hearing loss and incident dementia. Archives of Neurology, 68(2), 214-220.
Mitchell, P., Gopinath, B., McMahon, C., Rochtchina, E., Wang, J., Boyages, S. & Leeder, S. (2009). Relationship of type 2 diabetes to the prevalence, incidence and progression of age-related hearing loss. Diabetic Medicine, 26, 483-488.
Nachtegall, J., Smit, J., Smits, C., Bezemer, P., van Beek, J., Festen, J. & Kramer, S. (2009). The association between hearing status and psychosocial health before the age of 70 years: results from an internet-based national survey on hearing. Ear and Hearing, 30(3), 302-12.
