The connection between diabetes and hearing loss

More than 30 million Americans have diabetes — if you're one of them, take note. You may want to keep a close watch on your hearing, too. Research indicates diabetics are more than twice as likely to develop hearing loss than those without the disease.  

What is diabetes?

Very simply, 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. The number of people diagnosed with this disease is on the rise, jumping more than 50 percent in the last decade, according to the Diabetes Research Institute Foundation.

There are three types of diabetes:

• Those diagnosed with Type 1 diabetes are unable to produce the insulin required to move glucose into cells due to an autoimmune situation in which the body attacks the beta cells which produce the hormone.
• Those diagnosed with Type 2 diabetes are able to produce their own insulin; however, the quantity may not be sufficient or effective enough to move glucose into the cells.
• Some pregnant women develop gestational diabetes, a condition in which hormones make the body’s cells more resistant to insulin. Gestational diabetes typically disappears once the baby is delivered.  

In all three cases, the result is an elevation in blood sugar levels which must be managed. Diabetes is the leading cause of blindness, kidney failure, amputations, heart failure and stroke. Symptoms of the disease include frequent urination, increased thirst and/or hunger, sleepiness, weight loss, blurred vision, difficulty in concentrating and slow healing of infections.

What does diabetes have to do with hearing loss?

In recent years, two studies have examined the relationship between diabetes and hearing loss.

• 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 analyzed results from 13 studies involving more than 20,000 participants. The study concluded that diabetics were more likely to have hearing loss than those without the disease, regardless of their age.

Scientists are not entirely sure why diabetes negatively impacts the sense of hearing; however, they suspect high blood glucose levels cause damage to the small blood vessels in the inner ear.

Like other parts of the body, the hair cells of the inner ear rely on good circulation to maintain health. These hair cells are responsible for translating the noise our ears collect into electrical impulses, which they send along the auditory nerve to the brain to interpret as recognizable sound. These sensory hair cells, known as stereocilia, do not regenerate. Once they are damaged or die, hearing is permanently affected. The resulting sensorineural hearing loss can often be treated with hearing devices such as hearing aids or cochlear devices. A hearing evaluation will determine the amount of hearing loss; a hearing healthcare professional can interpret those results to recommend appropriate treatment options.

How to protect your hearing if you have diabetes

Although sensorineural hearing loss is permanent, it is possible to protect your remaining hearing.

• Turn down the volume on personal electronic devices, the television and car radio. Protect your ears from excessive noise with headphones or disposable earplugs if you engage in noisy hobbies or know you’ll be attending an event where noise levels will excessive.
• Incorporate an appropriate amount of exercise into your daily routine. Even a moderate amount improves circulation and blood flow. Talk to your doctor about what type of exercise is best for you.
• 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.  

Most importantly, schedule a hearing evaluation with a hearing healthcare professional as soon as possible and share your diabetes diagnosis as part of your medical history. This information, along with the results of your hearing evaluation, will help the two of you determine the best course of treatment going forward.