Diabetes is a chronic disease that affects about 30 million Americans. When one thinks of diabetes, the impact it has on other organs such as the kidneys, heart, eyes, and nervous system comes to mind first, and physicians tend to concentrate on these organs when treating diabetes. But recent studies have shown that people with type 1 or type 2 diabetes are twice as likely to develop hearing loss.
Recently, the correlation between diabetes and hearing loss has become so prevalent that the American Diabetes Association (ADA) has recognized hearing loss as a side effect of diabetes and added audiology/hearing testing to its list of recommended referrals for initial diabetes care management.
What is diabetes?
Diabetes affects the insulin levels in your blood. Insulin is a hormone produced in the pancreas that regulates the amount of glucose in the blood. Diabetes inhibits the body’s ability to produce and/or manage insulin appropriately, causing glucose to build up in the bloodstream instead of feeding hungry cells.
There are two types of diabetes: type 1 and type 2. People with type I diabetes are unable to produce the insulin required to move glucose into cells due to an autoimmune response in which the body attacks the beta cells that produce the hormone. This type can develop very quickly over the course of weeks and is sometimes called juvenile diabetes.
People diagnosed with type 2 diabetes can produce their own insulin; however, the quantity may not be sufficient or effective enough to move glucose into the cells. Many people with type 2 diabetes will not have symptoms for many years, and their symptoms often develop slowly over the course of time. Some people with type 2 diabetes have no symptoms at all and do not discover they have the condition until complications arise. Type 2 diabetes is usually diagnosed later in life.
Diabetes is the leading cause of blindness, kidney failure, amputations, heart failure, and stroke. Symptoms of diabetes include frequent urination, increased thirst and/or hunger, sleepiness, weight loss, blurred vision, difficulty in concentrating, and slow healing of infections (Healthy Hearing Nov 12, 2018).
How does diabetes affect hearing?
As mentioned earlier, people with diabetes are twice as likely to develop hearing loss compared to people without diabetes. In a 2008 study conducted by the National Institutes of Health (NIH), diabetic participants were found to be more than twice as likely to have mild to moderate hearing loss than those without the disease. The occurrence of high-frequency hearing loss was more prevalent in diabetics (54%) than in non-diabetics (32%). An additional study published in the Journal of Clinical Endocrinology & Metabolism in 2012 supported NIH’s previous findings. This study, which analyzed results from 13 studies involving more than 20,000 participants, concluded that diabetics were more likely to have hearing loss than those without the disease, regardless of their age. (Healthy Hearing Nov 12, 2018)
The question is, why? How does diabetes impact the auditory system? Research suggests that chronic hypoglycemia can cause hearing loss. This occurs due to auditory nerve damage. When exposed to elevated blood glucose levels over time, these nerves experience fiber loss and central auditory pathway demyelination and degeneration. Extended periods of hyperglycemia can also cause microangiopathy. This is a disease of the small blood vessels that causes the very tiny vessels in the inner ear to break and the vessels of the cochlea to thicken, making blood flow to that part of the ear difficult (AADE-In-Practice Sept 2014). This damage to the auditory system over time will cause permanent hearing loss.
How can you protect your hearing if you have diabetes?
If you have diabetes, it is especially important to protect your hearing. Start by decreasing your exposure to excessive noise. The wearing of hearing protection is important and will decrease your exposure to noise. Decrease the volume on your headphones, television, and car stereo. Wear hearing protection (ear plugs to earmuffs) when you are around firearms, fireworks, power tools, motorcycles, and ATVs. Another way to protect your hearing if you have diabetes is exercise. Exercise will increase blood flow and circulation, but always discuss any type of exercise with your physician before starting. Finally, maintain an appropriate weight. Excessive weight makes it more difficult for your heart to pump blood effectively to all parts of your body, including your ears.
As you would schedule yearly assessments for your kidneys and eyes, you should do the same for your hearing. As reported previously in this article, The American Diabetes Association has included audiology as part of the standard of care. It is important to schedule an appointment with an audiologist to establish a baseline and to treat any hearing loss that may have already occurred.
At Northwest Ohio Hearing Clinic, we will perform a diagnostic audiological evaluation, which includes a hearing assessment, middle ear function testing, speech understanding testing in quiet and noise, and, if needed, cochlear hair cell function. With this information, we can give you recommendations to preserve the hearing you have or correct the hearing loss that has already occurred. Waiting to treat any hearing loss that has already occurred will make it harder to treat in the future. Do not think that your hearing is “not bad enough” for amplification. Treating hearing loss sooner rather than later only improves your quality of life. If you or someone you know has diabetes, please call our office and schedule an appointment for an evaluation.
Dianna Randolph, AuD, CCC-A, is a Doctor of Audiology with Northwest Ohio Hearing Clinic, located at 1125 Hospital Dr., Suite 50 in Toledo (419-383-4012) and 1601 Brigham Dr., Suite 160 in Perrysburg (419-873-4327).