Diabetes and Hearing Loss: What Does the Research Show?
Most people know that diabetes can affect the eyes, kidneys and nerves. But did you know that it may also be associated with hearing loss? Recent research suggests that people with type 2 diabetes experience hearing difficulties more frequently than those without the condition.
Two major scientific reviews published in 2025 have provided further evidence of this association. But what exactly did the researchers discover, and what does it mean for patients?
What is the connection between diabetes and hearing loss?
Type 2 diabetes is a metabolic condition characterised by persistently elevated blood glucose levels.
Over time, diabetes can affect small blood vessels and nerves throughout the body. Researchers believe that similar changes may occur in the inner ear (cochlea), which plays a crucial role in hearing.
The cochlea contains delicate sensory hair cells and other structures that convert sound vibrations into electrical signals transmitted to the brain.
Several possible mechanisms have been proposed:
Microvascular damage: Changes in the tiny blood vessels supplying the inner ear may interfere with its normal function.
Nerve damage: Diabetes-related changes may affect parts of the auditory nervous system.
Oxidative stress: Metabolic disturbances may contribute to cellular damage within the cochlea.
Chronic inflammation: Inflammatory processes may also play a role in hearing deterioration.
These mechanisms remain under investigation. Although researchers have identified a clear statistical association, the precise biological relationship is not yet fully understood.
What did the 2025 research find?
Two systematic reviews and meta-analyses published in Otolaryngology–Head and Neck Surgery examined the relationship between type 2 diabetes and hearing loss.
Study 1: A review involving more than 100,000 participants
Kim and colleagues analysed 39 studies involving approximately 88,000 people with type 2 diabetes and 20,000 participants without diabetes.
Their findings showed that clinically significant hearing loss was more common among people with diabetes:
53% of participants with type 2 diabetes had hearing loss.
25.2% of those without diabetes had hearing loss.
The estimated relative risk was 2.3, suggesting that hearing loss was more than twice as common in the diabetes group.
The researchers also found that sensorineural hearing loss was particularly prominent.
Study 2: Another systematic review published in 2025
Caballero-Borrego and colleagues reviewed 17 studies involving approximately 8,000 participants in total.
They also found a significant association between type 2 diabetes and hearing loss.
Their analysis reported an odds ratio of 4.19 for hearing loss among people with diabetes compared with those without diabetes.
An odds ratio is not the same as relative risk, so the result should not be interpreted simply as hearing loss being four times more likely in every patient.
The researchers also found that hearing thresholds tended to be worse at higher frequencies.
Why do the estimates differ?
The reviews included different study populations and used different methods to evaluate hearing loss.
They also differed in the studies included and the statistical measures used. Some underlying research may overlap.
Nevertheless, both reviews support the same general conclusion: type 2 diabetes is associated with a higher prevalence of hearing impairment.
Importantly, these findings demonstrate an association, not definitive proof that diabetes directly causes hearing loss.
What type of hearing loss is most common?
The hearing impairment associated with diabetes is most commonly sensorineural hearing loss.
This means that the problem originates in the inner ear or auditory pathways rather than from a blockage in the external ear canal.
Typical features may include:
Gradual deterioration in hearing.
Difficulty understanding speech, particularly in noisy environments.
Reduced hearing sensitivity at higher frequencies.
Hearing loss affecting both ears.
However, hearing loss can have many different causes, including ageing, noise exposure, earwax accumulation, infections and other ear conditions.
A person with diabetes may therefore develop hearing loss for reasons entirely unrelated to their diabetes.
Does the duration or control of diabetes matter?
Some studies suggest that hearing impairment may be more common in people who have lived with diabetes for longer.
The 2025 review by Caballero-Borrego and colleagues found a higher prevalence of hearing loss among people who had diabetes for more than ten years.
The researchers also reported associations between higher HbA1c levels, which reflect average blood glucose over the preceding months, and greater hearing impairment.
These findings suggest that both disease duration and metabolic control may be relevant.
However, more research is needed to determine whether improved blood glucose control can directly prevent or slow diabetes-associated hearing loss.
Good diabetes management remains important for overall health, regardless of its potential effects on hearing.
Should people with diabetes have their hearing tested?
The research highlights the importance of greater awareness of hearing difficulties among people with type 2 diabetes.
A hearing assessment may be particularly useful if you notice:
Increasing difficulty understanding conversations.
Needing to turn up the television volume.
Difficulty following speech in background noise.
Persistent tinnitus or other changes in hearing.
Pure-tone audiometry can identify hearing loss and help determine its type and severity.
Depending on the findings, additional tests may be recommended.
Although researchers have suggested incorporating hearing assessments into diabetes care, there is currently no universally agreed screening interval specifically for diabetes-associated hearing loss.
Assessment should therefore be tailored to the patient's symptoms, age, risk factors and clinical circumstances.
Can diabetes-associated hearing loss be treated?
There is currently no established treatment that specifically reverses hearing loss attributed to diabetes-related inner ear changes.
Management depends on the type and severity of hearing impairment.
Options may include:
Hearing aids when clinically indicated.
Audiological rehabilitation and communication strategies.
Assessment and treatment of other contributing ear conditions.
Ongoing management of diabetes and associated cardiovascular risk factors.
For individuals with significant hearing impairment, appropriate hearing rehabilitation can improve communication and quality of life.
Sudden hearing loss is different: a sudden reduction in hearing should never be assumed to be a gradual complication of diabetes. It requires urgent medical assessment because some causes need prompt treatment.
What does this research mean for patients?
The findings from these recent studies provide another reason to pay attention to hearing health in people with diabetes.
The main messages are:
People with type 2 diabetes appear to experience hearing loss more frequently than those without diabetes.
The hearing loss is often sensorineural and may particularly affect higher frequencies.
Longer diabetes duration and poorer metabolic control may be associated with greater hearing impairment.
Hearing difficulties should not automatically be attributed to diabetes without an appropriate examination.
Diabetes does not necessarily mean that you will develop hearing loss. However, recognising changes in hearing and seeking assessment when necessary may help identify problems earlier.
At PARK-ENT, we offer ENT examinations and hearing assessments to investigate hearing difficulties and determine whether further audiological evaluation is required.
Scientific references
Kim CH et al. Characteristics of Hearing Loss in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis. Otolaryngology–Head and Neck Surgery. 2025. DOI: 10.1002/ohn.1378
Caballero-Borrego M et al. Type 2 Diabetes Mellitus and Hearing Loss: A PRISMA Systematic Review and Meta-Analysis. Otolaryngology–Head and Neck Surgery. 2025. DOI: 10.1002/ohn.1346
