Diabetes and Hearing Loss

Loss of hearing is common, affecting 1 in 6 people in the UK. While it’s typically part of the ageing process, there are a number of factors that can affect your hearing - including prolonged exposure to loud noise, as well as certain diseases and conditions, and a link has been found between hearing loss and diabetes.

Diabetes is a common, long-term health condition that alters the way your body converts food into energy.

When you eat, your body breaks down food into sugar (glucose) and your pancreas releases insulin to enable the sugar to enter your body’s cells. However, if you have diabetes, your body can’t make enough insulin or use it properly, resulting in too much blood sugar (glucose) in your bloodstream.

There are two main types of diabetes:

• Type 1 - an autoimmune reaction that prevents insulin production. It’s usually developed at a young age

• Type 2 - prevents your body from using insulin effectively. This type is usually developed in adulthood as a result of lifestyle choices

Scientists have been looking into the connection between diabetes and hearing loss since the 1960s. There has always been a link, but recent studies have concluded that people with diabetes are twice as likely to suffer from hearing loss as those without the condition. The link between diabetes and hearing loss was evident across all frequencies in the studies, with a stronger association in the high frequency range. Other factors commonly known to affect hearing were taken into account during research, including age, race, income level and noise exposure, yet a correlation between diabetes and hearing loss was still found.

Research has also shown that if you are a woman suffering from diabetes, you are likely to experience a higher degree of hearing loss than a woman without diabetes. However, it is not totally clear why diabetic women have a higher likelihood of suffering from hearing loss than men.

So the research shows that diabetes - both type 1 and type 2 - can affect your hearing.  Therefore, if you’re diabetic, it’s important to undergo regular hearing tests to assess your hearing and help you manage any hearing loss that may occur as a result of your condition.

The change in your hearing may start subtly, rather than as a sudden loss, and you may not notice it at first. In fact, your family or friends may notice before you do, particularly if you find yourself struggling to hear telephone conversations, or find that you’re turning the TV up a few notches. 

Difficulty hearing higher frequency sounds is one of the first signs that you may be experiencing a form of hearing loss related to diabetes. Such sounds include:

• Higher octaves such as birdsong

• Consonant sounds such as f, s, z and t

• Women’s or children’s voices

• Doorbells

Diabetes can impact your hearing, so if you’re diabetic, pay more attention to situations where you have to ask people to repeat themselves more often, or where you turn the volume up more than usual. And if you find these situations increasing, book a hearing test.

Although it’s unclear exactly why people with diabetes experience hearing loss, it’s thought that the main reason is related to the blood vessels in your ear.

Diabetes causes you to experience high blood sugar (glucose) levels as the lack of insulin means the sugar can’t enter your body’s cells.

Prolonged levels of high blood sugar can:

• Reduce your body’s circulation of blood and oxygen to the nerves and blood vessels in your inner ear

• Damage the protective layer of hair that covers your nerves inside your ear. These hairs are responsible for transmitting impulses from the cochlea to the hearing centre of the brain

• Block some sensory receptors in your ear

These ultimately damage the nerves and blood vessels of your ear, which then affect your ability to hear.

Nerve damage is a well-known complication of diabetes, so this applies to the auditory nerves in your ear too.

Your hearing can also be affected by periods of low blood sugar. Your ear contains a special fluid around the cochlea, which is vital for it to function. Low blood sugar levels cause a chemical imbalance in this fluid, thereby changing the way your ear processes sounds.

Nerve damage in the inner ear isn’t the only issue caused by diabetes; 1% of all diabetes patients are diagnosed with a subtype of the disease called Maternally Inherited Diabetes and Deafness (MIDD).

This occurs as a result of a mutation that happens in mitochondrial DNA, and 75% of people diagnosed with this suffer from sensorineural hearing loss, which is a permanent form of hearing loss. Sensorineural hearing loss is caused by damage to the inner ear, particularly to the tiny hairs on the cochlea which are responsible for converting sound waves into neural impulses for your brain to interpret. If these hairs can’t function properly, sound will become muffled or distorted.

There is no guaranteed way to prevent any form of hearing loss if you have diabetes. You may still experience hearing loss to some extent, but there are ways to try and decrease the severity:

• Stabilise your blood sugar levels so they’re not too high or too low for prolonged periods 

• Protect your ears from excessive noise

• Keep your ears clean to prevent infection (if you’re diabetic, you’re more susceptible to infections)

If you have diabetes and are concerned about suffering from hearing loss, book a hearing test at your nearest Boots store. Treatment can be more effective at an earlier stage, so it’s better to get a hearing test as soon as you notice any changes in your hearing so that any further damage can be prevented.