The risk of hearing loss is four times higher in people with type 2 diabetes than those without diabetes, a systematic review and meta-analysis show.
Researchers said the result was more pronounced than in other studies and findings indicated that comprehensive diabetes care should include hearing assessment.
Additionally, hearing loss could be an early indicator of microvascular disease, potentially prompting earlier intervention to prevent further complications.
The authors analysed data from 17 studies encompassing 3,910 people with diabetes and 4,084 controls.
“The findings of this meta-analysis suggest that the prevalence of hearing loss among individuals with diabetes ranges from 40.6% to 71.9%,” they said.
“The risk of hearing loss is 4.19 times higher in this group compared to the control group.”
This risk was predominantly observed at higher frequencies. Mean pure-tone audiometric thresholds of the diabetic group were 3.19 dB higher, and were higher for both low frequencies and, more severely, for high frequencies.
Duration and glucose control
Additionally, HbA1c levels appeared to be correlated with the severity of hearing loss as patients with moderate and severe-to-profound hearing loss had higher mean HbA1c levels than controls, suggesting poorer glucose control correlated with more severe hearing impairment.
The duration of diabetes also appeared to be a significant factor in the prevalence of hearing loss. Hearing loss prevalence was significantly higher among patients with a diagnosis of diabetes for more than 10 years, with these people facing a 2.07 times higher risk compared to those with shorter disease duration.
The gender of patients with diabetes had no influence.
Implications
The study’s authors suggested hearing loss in type 2 diabetes may result from microcirculatory alterations affecting the cochlea, leading to changes in the ultrastructure of the inner ear capillaries, including thickening of the basilar membrane and atrophy of the stria vascularis.
“Hearing loss in DM (diabetes mellitus) may be a consequence of subclinical microvascular disease,” they said.
“This fact could potentially serve as an early warning sign, suggesting that closer monitoring is necessary, as well as the adaptation of treatment plans to minimise the occurrence or progression of hearing loss.”
Findings were published in the November 2025 issue of Otolaryngology–Head and Neck Surgery, the peer-reviewed journal of the American Academy of Otolaryngology–Head and Neck Surgery Foundation.
Study authors were Dr Miguel Caballero-Borrego from the Department of Otorhinolaryngology, Hospital Clínic, Barcelona, Spain and Dr Ivan Andujar-Lara, MD, from Hospital Clínic and Universitat de Barcelona.
Studies analysed were all high-quality level three evidence studies except for one moderate quality study. Populations studied were from the US, Greece, South Africa, China, South Korea, India, Iran, Jordan, Egypt and Saudi Arabia.
The researchers said this significantly elevated risk of hearing loss was a complication that often went unrecognised and unscreened.
