Hearing Loss Affects 1 in 4 Adults with Type 2 Diabetes, Systematic Review Reveals

A comprehensive systematic review and meta-analysis published in Diabetes Metabolism Research and Reviews has found that clinically significant hearing loss (search)Search disease is strikingly common among adults with type 2 diabetes (search)Search disease, with approximately one in four affected individuals experiencing moderate-to-severe impairment. The analysis, which pooled data from 29 observational studies involving more than 17,000 participants worldwide, suggests that hearing loss may represent an under-recognized complication of diabetes that has largely fallen through the cracks of standard care protocols.

The findings indicate that adults with diabetes were more than twice as likely to have clinically significant hearing loss (search)Search disease compared to those without the condition. Based on estimates from the World Health Organization, the researchers suggest that hundreds of millions of people globally may be living with serious hearing impairment as a complication of diabetes.

A hidden complication with a substantial burden

Lead study author Mehwish Nisar, MD, PhD, AFHEA, a Postdoctoral Research Fellow and Affiliate of the University of Queensland Centre for Hearing Research (search)Search term (CHEAR), explained why hearing loss (search)Search disease has received comparatively little attention in diabetes care.

"Retinopathy, nephropathy and neuropathy are complications with established, formalised screening pathways in diabetes care, so they're front of mind for clinicians and patients alike," Nisar said. "Hearing loss (search)Search disease has never been systematically built into those care protocols, so it's essentially fallen through the cracks — not because the biological link isn't real, but because it hasn't been prioritised or measured with the same rigour."

Nisar further noted that previous studies had "lumped together all severities of hearing loss (search)Search disease, including very mild, subclinical changes, which may have understated how much of this burden is actually clinically significant and disabling."

Key findings across populations

Across 23 studies involving more than 5,200 people with diabetes, the researchers found that around one in four had moderate-to-severe hearing loss (search)Search disease. When comparing data from 11 studies that included participants both with and without diabetes, individuals with diabetes were more than twice as likely to have clinically significant hearing loss.

The association was strongest in adults under the age of 60, who were approximately three times more likely to have moderate-to-severe hearing loss (search)Search disease than people of the same age without diabetes. Notably, the increased risk was also present among those who had been living with diabetes for fewer than 10 years, suggesting that hearing problems may develop earlier than previously thought.

The link between diabetes and hearing loss (search)Search disease was also stronger in studies from low- and middle-income countries, though the researchers emphasized that more investigation is needed to understand the reasons behind this disparity.

"One in four adults with diabetes has hearing loss (search)Search disease serious enough to struggle in everyday conversation — the kind that needs hearing aids. Yet it is not on doctors' checklists," Nisar said. "This is a similar scale of burden to complications like retinopathy or nephropathy, which are already routinely screened for, yet hearing is not."

Biological mechanisms and early warning signs

Although the review did not directly investigate biological mechanisms, Nisar described the likely pathways involved. "Chronic high blood glucose damages the small blood vessels and nerves supplying the cochlea, in much the same way it damages the retina, kidneys, and peripheral nerves," she explained. "This includes microangiopathy, oxidative stress, and neuropathy affecting the auditory nerve pathways."

The Centers for Disease Control and Prevention has previously stated that hearing loss (search)Search disease is twice as common in people with diabetes, with those with prediabetes (search)Search disease having a 30% higher rate of hearing loss.

Nisar outlined the early warning signs that clinicians and patients should watch for: "Early signs include difficulty following conversations in noisy environments, frequently asking people to repeat themselves, turning up the TV or phone volume more than usual, or feeling more fatigued after conversations because of the extra effort of listening."

She cautioned that "because hearing loss (search)Search disease tends to progress gradually, people often adapt without realising there's a problem."

A call for routine screening

The study authors argue that hearing assessments should become a routine part of diabetes care, integrated alongside existing screening for retinopathy, nephropathy, and neuropathy. Standard pure-tone audiometric hearing tests are described as relatively simple, non-invasive, and inexpensive.

"If someone with diabetes notices any of these changes, they should do a pure-tone audiometric hearing test — it's simple, low-cost, and can catch clinically meaningful hearing loss (search)Search disease before it becomes disabling," Nisar advised.

"We'd like routine audiometric screening built into standard diabetes care, the same way eye and kidney checks are," Nisar concluded. "This is especially urgent for younger adults, where the hearing loss (search)Search disease risk was highest and least likely to be confused with normal age-related decline, and for people in low- and middle-income countries, where we found the highest risk but the least access to audiology services and hearing aids."

Study limitations

The researchers acknowledge important limitations. Because the review included only observational studies, it cannot establish that diabetes directly causes hearing loss (search)Search disease — it can only demonstrate an association. Other factors such as age, cardiovascular disease, noise exposure, smoking, and certain medications may also contribute to hearing loss. The authors note that further prospective studies are necessary to clarify the relationship and determine whether routine hearing screening improves long-term outcomes for people living with diabetes.

Despite these caveats, the review adds substantial weight to the growing body of evidence suggesting that hearing health deserves greater attention in diabetes care. For people living with diabetes, the authors recommend discussing any changes in hearing with a healthcare professional, rather than waiting until the impairment becomes advanced or dismissing it as a normal part of aging.